GOST 19658-81

• gost-19658-81.pdf (1.20 MiB)
  ГОСТ 19658-81

GOST 19658−81 Silicon monocrystalline in ingots. Specifications (with Amendments No. 1, 2)

GOST 19658−81
Group W51

INTERSTATE STANDARD

SILICON MONOCRYSTALLINE IN INGOTS

Specifications

Monocrystalline silicon in ingots. Specifications

GST 17 7213

Date of introduction 1983−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

DEVELOPERS

V. S. Matveev, PhD. tech. Sciences; A. G. Valkanov; M. B. Reifman, PhD. chem. Sciences; L. I. Vlasov; R. I. Genkin, I. P. Kaganovsky, PhD. tech. Sciences; L. V. Kulikov, L. V. Liner, Cand. tech. Sciences; V. I. Markov, A. I. Popov; N. N. Soloviev, PhD. tech. science; B. M. turovskiy, d-R tekhn. Sciences

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 27.02.81 N 1090

3. REPLACE GOST 19658−74

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

The designation of the reference document referenced	The item number, app
GOST 2.004−88	1.1
GOST 61−75	App 7, 8A, 9
GOST 334−73	Annex 8
GOST 427−75	Annex 1
GOST 701−89	Annexes 4, 8, 8A, 9
GOST 1367.0−83	Annex 9
GOST 1770−74	Annex 9
GOST 2263−79	Appendix 6
GOST 2548−77	App 1, 4, 9
GOST 2567−89	Application 4, 9
GOST 2789−73	Appendix 3
GOST 2874−82	Annex 8, 9
GOST 3647−80	Application 3, 6, 7, 8, 8A
GOST 3776−78	Application 4, 9
GOST 4160−74	App 7, 8A
GOST 4220−75	Annex 4
GOST 4461−77	Applications 4, 7, 9
GOST 5017−74	Annex 8
GOST 5959−80	4.5
GOST 5962−67	App 3, 8
GOST 9206−80	Application 3, 4, 6, 7, 8, 8A, 9
GOST 9285−78	Appendix 6
GOST 9412−93	App 3, 8
GOST 9696−82	Application 5, 7, 8A
GOST 10197−70	Annex 5
GOST 10354−82	4.1
GOST 10484−78	App 1, 4, 7, 8A, 9
GOST 11069−74	Annex 8
GOST 11078−78	Appendix 6
GOST 11109−90	App 5, 8
GOST 11125−84	App 4, 8A, 9
GOST 12026−76	Applications 3, 4, 5, 8, 9
GOST 12997−84	App 7, 8A
GOST 14192−96	4.6
GOST 17299−78	App 7, 8A
GOST 18270−72	Annex 9
GOST 18300−87	App 3, 7, 8, 8A
GOST 20477−86	4.2, 4.3
GOST 24392−80	Annex 4
GOST 25593−83	App 7, 8A
GOST 26239.1−84	3.8 b
GOST 29298−92	App 3, 7, 8A, 8, 9
GOST 29329−92	Application 4, 9
THAT 6−09−3401−70	Annex 9
THAT 6−09−4015−78	App 1, 9
TU 25−10 (AMTS.778.019)-84	Appendix 3
TU 25−10 (AMTS.778.020)-84	Appendix 3

5. The expiration time limit is removed by the Resolution of Gosstandart No. 480 from 12.05.92

6. EDITION with Amendments No. 1, 2 approved in July 1987, may 1992 (IUS 11−87, 8−92)


This standard covers ingots of monocrystalline silicon obtained by the Czochralski method and designed for the manufacture of wafers-substrates used in the manufacture of epitaxial structures and structures of metal — insulator — semiconductor.

(Changed edition, Rev. N 2).

1. TECHNICAL REQUIREMENTS

1.1. Ingots of monocrystalline silicon are made in accordance with the requirements of this standard hole type of conductivity (D) doped with boron (B), and electronic type of conductivity (e) doped with phosphorus (p) or antimony ©, mesdication (with dislocation density of not more than 1·10cm) according to the technical documentation.

If the documentation with the use of print and automated devices indexes of additional requirements in the name of the stamps to be printed in accordance with the requirements of GOST 2.004.

Ingots of monocrystalline silicon should meet the requirements specified in the table.

Table

			Specific electrical resistance (resistivity)
Mark	Group	Subgroup	Interval nomi- tional values of UES, Ohm·cm	The relative deviation of the average values of UES of the ends of the nominal value of UES, %	The radial relative deviation of the resistivity from the average value at the end ingot, %	The nominal diameter of the ingot, mm	The base length of the ingot, mm not less than
ACDB	1	and				62,5	100
		b	0,005−20			78,5	150
		in		35	10	102,5	250
		g				127,5	250
		d	Of 0.1−20			152,5	250
	2	and				62,5	100
		b	0,005−20			78,5	100
		in		25	10	102,5	200
		g				127,5	200
		d	Of 0.1−20			152,5	250
	3	and				62,5	100
		6	0,005−20			78,5	100
		in		20	10	102,5	150
		g	Of 0.1−20			127,5	200
		d	Of 0.1−15			152,5	250
	4	and				62,5	100
		b	0,005−20			78,5	100
		in		15	10	102,5	150
		g	Of 0.1−20			127,5	150
		d	Of 0.1−15			152,5	200
	5	and				62,5	100
		b	20−40	35	15	78,5	150
		in				102,5	200
		g				127,5	250
		d				152,5	250
	6	and				62,5	100
		b				78,5	100
		in	20−40	25	15	102,5	200
		g				127,5	200
		d				152,5	250
	7	and				62,5	100
		b	20−40	20	15	78,5	100
		in				102,5	150
		g				127,5	150
	8	and	20−40			62,5	100
		b	20−40	20	10	78,5	100
		in	20−80			102,5	150
		g	20−40			127,5	150
ACES	11	and				62,5	100
		b	0,01−1	35	20	78,5	150
		in				102,5	200
	12	and				62,5	100
		b	0,01−1	20	15	78,5	100
ECAF	21	and				62,5	100
		b				78,5	150
		in	Of 0.1−20	40	20	102,5	200
		g				127,5	200
		d				152,5	250
	22	and				62,5	100
		b				78,5	100
		in	Of 0.1−20	30	15	102,5	200
		g				127,5	200
		d				152,5	250
	23	and				62,5	100
		b	Of 0.1−20			78,5	100
		in		20	15	102,5	150
		g	Of 0.1−15			127,5	150
		d				152,5	200
	24	and				62,5	100
		b	Of 0.1−20	20	10	78,5	100
		in				102,5	150
		g	Of 0.1−15			127,5	150
		d				152,5	200
	25	and				62,5	100
		b				78,5	150
		in	20−40	40	20	102,5	250
		g				127,5	250
		d				152,5	250
	26	and				62,5	100
		b				78,5	100
		in	20−40	30	15	102,5	200
		g				127,5	200
		d				152,5	250

Notes:

1. Bars with a specified base length shall be not less than 75% of the total volume of this grade of silicon.

2. The minimum length of the ingots of monocrystalline silicon should not be less than the diameter of the ingot.

1.2. The crystallographic orientation of the plane face of the slice of monocrystalline ingot of silicon, the (111) or (100), the index «m» and (013) index «a» for silicon ingots doped with boron and phosphorus, with electrical resistivity of 1−15 Ω·cm.

1.3. The deflection angle of the end plane of the slice monocrystalline silicon ingots from a given crystallographic plane () should not exceed 3°.

1.4. The ingot should be monocrystalline, and must not have the appearance of defects (chips, shells) larger than 3 mm and cracks. On the end sections of the ingots are allowed chamfers with linear dimensions not exceeding 3 mm.

1.5. The concentration of optically active atoms of oxygen needs to be (2−9)·10cmingot of silicon with a diameter of less than 150 mm and (2−10)·10cmingot of silicon with a diameter of 150 and 152,5 mm when the calibration coefficient equal to 2.45·10cm, instead of 3.3·10cm, specified in the application

7.

1.1.-1.5. (Changed edition, Rev. N 1).

1.5. The concentration of optically active atoms of carbon should be not more than 1·10cmin silicon ingots with a diameter of 78.5 mm or more and not more than 3·10cmingot of silicon with a diameter of 62.5 mm.

1.5 b. The concentration of the atoms of each of the trace impurities of iron, gold and copper in ingots of monocrystalline silicon should be not more than 1·10cm.

1.5 a, 1.5 b. (Added, Rev. N 1).

1.6. Ingots of silicon with a specific electrical resistance of more than 3.0 Ω·cm should have a life time of minority carriers: for the electronic conductivity of not less than 7.5 µs for the hole conductivity of not less than 2.5 µs.

At customer’s request, produce ingots of silicon doped with boron or phosphorous, with the lifetime of nonequilibrium charge carriers (N. N. z.), not less than:

(2−30 µs) for bars with a specific electrical resistance of 1−15 Ω·cm (index «e»);

(16−60 ISS), for bars of diameter not less than 100 mm with a specific electric resistance from 4 to 15 Ω·cm (index «R»);

(30−160 MS), for bars of diameter not less than 100 mm specific electrical resistance of 15−80 Ohm·cm (index «e»).

(Changed edition, Rev. N 1).

1.7. Permissible limit deviation of the diameter of silicon ingots from the nominal shall not exceed plus 3 or minus 2 mm.

1.8. Allow for the processing of the lateral surface of ingots of monocrystalline silicon when they are brought to a given diameter. Permitted ingots of silicon with etched ends.

(Changed edition, Rev. N 2).

1.9. At customer’s request, ingots of silicon can be manufactured with nominal diameters 60, 76, 100, 125, 150 mm with permissible deviations of ±0.5 mm (the subscript «»).

By agreement between manufacturer and consumer silicon ingots can be manufactured with nominal diameters 60, 76, 100, 125, 150 mm with a permissible deviation ±0.1 mm (the subscript «»).

1.10. At customer’s request, ingots of silicon, doped with phosphorus or boron, specific electrical resistance of 0.3 Ω·cm or more shall be made without svircevic of defects (the index «») — for bars with orientation (100) and (013) and (index «a») — for bars with (111) orientation.

The density of micro-defects revealed by etching, should not be more than 2·10cmfor bars with the orientation (100) and (013) index of «» and no more than 3·10cmfor bars with the orientation (111) (index «a»

).

1.11. The crystallographic orientation of the plane end of the cut, the angle of deviation of the plane face of the slice from a given crystallographic plane, no external defects, the concentration of optically active oxygen atoms and carbon atom concentration of trace impurities of iron, gold and copper, the dislocation density, the lifetime of nonequilibrium charge carriers (for the bars without indexes «e» and «R») and the lack swirley defects for bars with indexes «and » provided by technology.

The symbol of ingots of monocrystalline silicon should contain: brand silicon, the nominal value of resistivity, a group, a subgroup, the diameter of the ingot, the crystallographic orientation of the plane end of the cut single crystal ingot, indices and designation of the present standard. The lack of an index «m» or «e» means the crystallographic orientation of the plane face of the slice ingot (111).

Examples of symbols:

Silicon stamps ACDB with a nominal value of resistivity of 2 Ω·cm, group 1, subgroups a, calibrated with tolerance of 0.5 mm, with the crystallographic orientation of the plane end of the cut single crystal ingot (111)

EKDB-2−1AKGOST 19658−81

Silicon stamps ECAF with a nominal value of resistivity of 10 Ω·cm, group 6, subgroup b, calibrated with a tolerance of 0.1 mm with the crystallographic orientation of the plane end of the cut single crystal ingot (100), without swirley defects

ACAF-20−6BKMSGOST 19658−81.

1.8.-1.11. (Changed edition, Rev. N 1).

1.12. OKP codes are given in Appendix 1A.

(Added, Rev. N 1).

2. ACCEPTANCE RULES

2.1. Each silicon ingot is subjected to control by determining the conductivity type, resistivity, diameter, length, and mass.

Control provide technology options should be carried out periodically, at least once in six months on a single silicon ingot.

2.2. Each ingot of monocrystalline silicon is accompanied by a quality document in which you specify:

trademark or the name and trademark of manufacturer;

the name of the product and its brand;

the number of the ingot;

type of conductivity;

the average value of specific electrical resistance at each end;

the value of the relative deviation of the average values of electrical resistivity of the ends of the ingot from the nominal value;

the magnitude of the radial relative deviation of the resistivity from the average value at the end of the ingot;

the lifetime of nonequilibrium charge carriers (for bars with indexes «e» and «R»);

the length and diameter of ingot, mm;

the net mass, g;

the date of manufacture;

stamp of technical control;

the designation of this standard.

Sec. 2. (Changed edition, Rev. N 1).

3. CONTROL METHODS

3.1. Inspection of silicon ingots monocrystalline and the absence of external surface defects is carried out according to methodology described in Annex 1.

3.2. Type of conductivity determined by the method given in Appendix 2. The type of conductivity of ingots with diameter mm 152,5 define similar adjacent to each of the ends of the ingot are annealed washers (thickness 4−30 mm).

3.3. Electrical resistivity is measured at both end faces of ingots of monocrystalline silicon or adjacent to each of the ends in the annealed goals in six fixed locations in two mutually perpendicular directions, the diameter of the ingot according to the method specified in Annex 3.

3.4. The dislocation density determined at the bottom end of the ingot or in the adjacent washer according to methodology described in Annex 4; for ingots with a diameter of 150 mm and more is used only the untreated washer.

3.2.-3.4. (Changed edition, Rev. N 1).

3.5. The diameter of the ingots is measured in randomly selected on the circumference points anywhere along the length of the ingot with an error of less than 0.1 mm, and the length — with an accuracy of at least 1 mm. the measured standard measuring tools to ensure the specified accuracy of the measurement.

3.6. The weight of the ingot is determined by weighing:

up to 2 kg on the scales with accuracy of at least ±2 g;

up to 10 kg on the scales with accuracy of at least ±5 g;

up to 30 kg on the scales with accuracy up to ±50 g.

Allowed determination of the mass of the ingot by calculation based on its volume and the density of silicon to be 2.33 g·cm. If there is disagreement in the determination of the mass of the ingot is determined by weighing.

3.7. The deflection angle of the plane end of the cut single crystal silicon ingot is measured according to methods given in annexes 5 and 6.

The identification of the crystallographic orientation of the plane face of the slice of monocrystalline silicon ingot with a given crystallographic plane is carried out according to methodology described in Appendix 5.

3.8. The concentration of optically active atoms of oxygen in ingots monocrystalline silicon is determined by the method given in Annex 7. When calculating the atomic concentration of optically active oxygen is allowed to use a calibration ratio of 2.45·10cm.

3.6.-3.8. (Changed edition, Rev. N 1).

3.8. The concentration of optically active atoms of carbon in the ingots of monocrystalline silicon to define the bottom end of the ingot according to the method specified in Appendix 8A.

3.8 b. The concentration of atoms of trace impurities of iron, gold and copper is determined at the bottom end of the ingot according to GOST 26239.1.

3.8 a, 3.8 b. (Added, Rev. N 1).

3.9. The lifetime of nonequilibrium charge carriers in silicon bars is measured on both ends of the ingot at three points, one of which is located in the center, and the other two in diameter at a distance of 0.7 of the radius from the center, according to methodology described in Annex 8.

3.10. Swirley the absence of defects determine the density of micro-defects directly on the upper and lower ends of the ingot or adjacent to each of the ends of the control disc according to methodology described in Annex 9. for bars with a diameter of 150 mm and more are used only the untreated washer.

3.9, 3.10. (Changed edition, Rev. N 1).

3.11. Allowed to control electrophysical parameters of ingots of monocrystalline silicon with a diameter of 100; 102,5; 125; 127,5; 150 152,5 mm washers adjacent to the upper and lower ends of the bars. To measure the resistivity and type of conductivity of the washer is previously subjected to heat treatment.

3.12. Annealing the washers is carried out at =600−700 °C for 20−60 min with subsequent cooling in air.

3.13. At the request of the consumer goals, which were measured, are supplied together with the ingot. The mass of the washers included in the weight of marketable products.

3.11.-3.13. (Added, Rev. N 1).

4. PACKING, MARKING, TRANSPORTATION AND STORAGE

4.1. Each silicon ingot is placed in a package of polyethylene film according to GOST 10354.

Allowed in the package with the ingot to attach a document about quality.

4.2. Plastic bag sealed or sealed with tape with adhesive layer according to GOST 20477 or tape of a similar type and Packed in a cardboard or plastic box with soft padding.

Allowed to attach a document on quality in the box with the ingot.

Box with lid tie lapped polyethylene tape with adhesive layer according to GOST 20477 or tape of the same type.

(Changed edition, Rev. N 1).

4.3. A different kind of packaging: the silicon ingot brewed in a plastic bag wrapped in elastic polyurethane foam or other soft packaging and tie lapped polyethylene tape with adhesive layer according to GOST 20477 or another tape of the same type. Packed in such a way the ingot placed in a plastic bag, in which put one side of the label, a quality document, then the package is sealed.

(Changed edition, Rev. N 1, 2).

4.4. On the box label showing:

name or trademark of the manufacturer;

product;

brand;

document number the quality;

rooms of the ingot;

the length and diameter of ingot, mm;

net mass, g;

the date of manufacture.

the names and numbers of the packer;

designation of this standard.

(Changed edition, Rev. N 2).

4.5. Ingots of silicon, Packed in accordance with the requirements of the PP.4.1−4.3, placed in wooden or plywood boxes according to GOST 5959.

Each box must be attached to packing list stating:

the name and trademark of manufacturer;

net mass in kilograms;

product;

the number of bars in the box;

date of packing;

the names and numbers of the packer.

May be specified in the packing list for more data.

Bars may be Packed in reusable containers, made according to normative-technical documentation.

(Changed edition, Rev. N 1, 2).

4.6. Labeling boxes according to GOST 14192 with the application of warning signs:

«The fragile. Caution»;

«Keep away from moisture»;

The «top».

4.7. Transportation of silicon ingots is carried out by all types of transport in covered vehicles in accordance with the rules of transportation of cargoes effective for this transport.

It is allowed to transport ingots of silicon postal parcels. When transporting postal parcels warning signs do not cause.

(Changed edition, Rev. N 1).

4.8. Ingots of silicon should be stored in the manufacturer’s packaging in covered warehouses.

5. MANUFACTURER’S WARRANTY

5.1. The manufacturer guarantees the conformity of silicon ingots to the requirements of this standard when complying with the storage conditions in the manufacturer’s packaging.

5.2. Warranty period of product is 1 year from the date of manufacture.

(Changed edition, Rev. N 1).

APP 1a (required)

ANNEX 1a
Mandatory

Mark	OKP code
ACDB 1A	17 7213 0111 06
ACDB 1B	17 7213 0112 05
ACDB 1V	17 7213 0113 04
ACDB 1G	17 7213 0114 03
ACDB 1D	17 7213 0115 02
ACDB 2A	17 7213 0121 04
ACDB 2B	17 7213 0122 03
ACDB 2B	17 7213 0123 02
ACDB 2G	17 7213 0124 01
ACDB 2D	17 7213 0125 00
ACDB 3A	17 7213 0131 02
ACDB 3b	17 7213 0132 01
ACDB 3V	17 7213 0133 00
ACDB 3G	17 7213 0134 10
ACDB 3D	17 7213 0135 09
ACDB 4A	17 7213 0141 00
ACDB 4B	17 7213 0142 10
ACDB 4B	17 7213 0143 09
ACDB 4G	17 7213 0144 08
ACDB 4D	17 7213 0145 07
ACDB 5A	17 7213 0151 09
ACDB 5B	17 7213 0152 08
ACDB 5V	17 7213 0153 07
ACDB 5g	7213 06 17 0154
ACDB 5D	17 7213 0155 05
ACDB 6A	17 7213 0161 07
ACDB 6b	17 7213 0162 06
ACDB 6V	17 7213 0163 05
ACDB 6g	17 7213 0164 04
ACDB 6D	17 7213 03 0165
ECDB 7a	17 7213 0171 05
ACDB 7b	17 7213 0172 04
ACDB 7V	17 7213 0173 03
ACDB 7G	17 7213 0174 02
ACDB 8A	17 7213 0181 03
ACDB 8b	17 7213 0182 02
ACDB 8V	17 7213 0183 01
ACDB 8G	17 7213 0184 00
11a, ACES	7213 17 0211 03
11b, ACES	17 7213 0212 02
11b, ACES	17 7213 0213 01
12A, ACES	17 7213 0221 01
12B, ACES	17 7213 0222 00
ECAF 21A	17 7213 0311 00
ECAF 21B	17 7213 0312 10
ECAF 21V	17 7213 0313 09
ECAF 21G	17 7213 0314 08
ECAF 21D	17 7213 0315 07
ECAF 22A	17 7213 0321 09
ECAF 22b	17 7213 0322 08
ECAF 22V	17 7213 0323 07
ECAF 22g	17 7213 0324 06
ECAF 22E	17 7213 0325 05
ECAF 23a	17 7213 0331 07
ECAF 23B	17 7213 0332 06
ECAF 23V	17 7213 0333 05
ECAF 23g	17 7213 0334 04
ECAF 23д	17 7213 0335 03
ECAF 24A	17 7213 0341 05
ECAF 24B	17 7213 0342 04
ECAF 24V	17 7213 0343 03
ECAF 24g	17 7213 0344 02
ECAF 24D	17 7213 0345 01
ECAF 25A	17 7213 0351 03
ECAF 25B	17 7213 0352 02
ECAF 25V	17 7213 0353 01
ECAF 25g	17 7213 0354 00
ECAF 25d	17 7213 0355 10
ECAF 26a	17 7213 0361 01
ECAF 26B	17 7213 0362 00
ECAF 26V	17 7213 0363 10
ECAF 26g	17 7213 0364 09
ECAF 26D	17 7213 0365 08

ANNEX 1a. (Added, Rev. N 1).

ANNEX 1 (mandatory). DEFINITION OF MONOCRYSTALLINE AND ABSENCE OF EXTERNAL DEFECTS ON THE SURFACE OF SILICON INGOTS

ANNEX 1
Mandatory

The technique is intended for a quality control visual inspection the entire surface of silicon ingots of electronic and hole types of conductivity with different specific electric resistance with crystallographic orientation (111), (100) and (013).

The technique allows to control the presence of macroscopic defects in structures that violate monocrystalline ingot (grain boundaries and twinning, with twin lamellae) and external defects (macroscopic cracks, spalls and cracks).

The technique is based on visual inspection of the entire surface of the ingot, which reveal the presence of macroscopic structure defects and external defects.

Control of the listed defects is carried out at a standard out-of-focus light.

All natural or machined surface of the ingots examined visually immediately after their cultivation or after chemical etching. Etching is carried out in a mixture of fluoride-hydrogen acid (HF) and an aqueous solution of chromic anhydride (CrO250−500 g/DM), taken in the ratio 1:(2−4) ppm.

To control the presence of cracks, spalls and cracks special etching is not carried out.

1. Equipment and materials

Table lamp with a capacity of at least 40 watts.

The metal ruler according to GOST 427.

Hydrofluoric acid OS.h. on the other 6−09−4015, H. h; h; h. d. a. according to GOST 10484.

Chromic anhydride h. d. a. for scientific and technical documentation, technical GOST 2548.

2. Control

2.1. Testing for the presence of macroscopic cracks, spalls, cracks, grain boundaries, boundaries of twinning and twinning lamellae is carried out visually.

2.2. The presence of grain boundaries on the lateral surface, and at the ends after machining, the ingots detect the change in light reflected by the surface is controlled by the displacement of its position relative to the light source.

After chemical etching of the grain boundaries are identified in clearly visible randomly oriented strips of etching (Fig.1).

Damn.1. Grain boundaries in ingots of silicon after chemical etching

Grain boundaries in ingots of silicon after chemical etching
and on the lateral surface	b on the end surface
Damn.1

2.3. The presence of the boundaries of twinning on the lateral surface of the ingot and on its ends (Fig.2) determined by the change of light reflection regions divided by the borders of twinning; on the surfaces after the chemical etching and the presence of clearly visible bands of etching, which usually comes out on the lateral surface or ends at the other defect.

Damn.2. The boundaries of the twinning in single-crystal ingots of silicon

The boundaries of the twinning in single-crystal ingots of silicon
and on the lateral surface (without etching)	b on the end surface after chemical etching	in microcatena the boundaries of twinning after chemical etching
Damn.2

2.4. The presence of twin lamellae in the ingot is determined after chemical etching by the presence of clearly visible bands of etching, similar to the twinning boundary (Fig.3).

Damn.3. Twin lamellae on the end face of the single crystal ingot, detectable after chemical etching

Twin lamellae on the end face of the single crystal ingot, find
after chemical etching

Damn.3

2.5. The silicon ingot is a single crystal with no grain boundaries, the boundaries of twinning and twinning lamellae.

3. Qualifications of the operator

Qualification of operator to the extent necessary to determine monocrystalline of silicon ingots, must meet the requirements of measuring electrical parameters of semiconductor materials of the third or higher rank in accordance with the current tariff-qualification Handbook.

4. Safety requirements

The chemical etching of the main precautions apply to the storage of reagents, dilution solutions of acids, alkalis and salts and their use in cold and heated state, and when the electrolytic etching.

Work with chemicals should be carried out in accordance with the «Basic rules of safe work in the chemical laboratory"*.
________________
* On the territory of the Russian Federation the document is not valid. Acts PND f 12.13.1−03, here and hereafter. — Note the manufacturer’s database.


APPENDIX 1. (Changed edition, Rev. N 1).

ANNEX 2 (mandatory). DETERMINATION OF TYPE OF CONDUCTIVITY

ANNEX 2
Mandatory

The method is designed to determine the type of electrical conductivity of doped single-crystal silicon ingots.

The definition of the type conductivity monocrystalline silicon ingots can be carried out:

method of using a thermal probe (thermoelectric power);

the method of point-contact rectification.

A method of using a thermal probe is recommended for silicon ingots with a specific electric resistance less than 100 Ω·cm; point of contact rectification — silicon ingots with electrical resistivity more than 10 Ohm·cm.

1. The definition of the type of conductivity of a method of using a thermal probe

1.1. The essence of the method

The method consists in determining the polarity of the thermoelectric power that occurs between the heated and cooler areas of the semiconductor, by using a sensitive null indicator.

The temperature gradient creates a local heating of the sample as a result of the pressure of the heated probe.

Schematic diagram for determination of conductivity type by hot probe shown in hell.1.

Damn.1. Schematic diagram for determination of conductivity type by hot probe

1 — probe; 2 — sample; 3 — metallic plate; 4 — zero-indicator

Damn.1

1.2. Requirements applicable to means of measurement

1.2.1. The probe is made of any conductive material. It is recommended to use materials not subject to corrosion when heated (e.g., Nickel). The second contact is a metal plate of copper or lead.

1.2.2. Heating the probe to a temperature not below 60 °C can be any heating device. The temperature display is carried out visually by the melting of the granules of alloy wood provided in thermal contact with the probe.

When determining the type of conductivity, the probe should be cleaned from traces of wood’s alloy.

1.2.3. As indicator use a galvanometer with a sensitivity of at least 4·10A/div (for example, type M-195/2, or M-195/3). Allowed to use the installations of type TP-101, TP-201, or other indicators with parameters, accuracy is not inferior to those specified.

(Changed edition, Rev. N 1).

1.3. Preparation of ingots

Surface bars should not be visible to the naked eye traces of oxidation or tint. Change on the surface obtained after cutting with a diamond tool or abrasive treatment.

1.4. Determination of type of conductivity

1.4.1. Determination of type of conductivity is carried out at a temperature of (23±2) °C.

1.4.2. Pressing the heated probe to the sample surface is included in the measuring circuit (Fig.1) gain a greater deflection of the null indicator.

1.4.3. The deflection of the null indicator determines the type of conductivity. The deflection of the null indicator must exceed the full scale of the device by 30%. To fulfil this requirement may increase the temperature difference between the probe and the ingot.

2. The type definition of conductivity by the method of point-contact rectification

2.1. The essence of the method

The rectifying properties of the contact metal-semiconductor is determined by the type of charge carriers in the semiconductor. The method is based on a qualitative comparison of the resistance of a point contact metal-semiconductor under different polarities of applied voltage. Type of electrical conductivity is determined by the deflection current-sensitive null indicator or by referring to the current-voltage curve obtained on the oscilloscope screen.

Schematic diagram to determine the type of electrical conductivity by the method of point-contact rectification with the use of the zero-indicator and oscilloscope b given on features.2.

Damn.2. Schematic diagram to determine the type of electrical conductivity by the method of point-contact rectification

1 — point contact (probe); 2 — bar; 3 — ohmic contact; 4 — autotransformer; 5 — zero indicator;
6 — branch to the horizontal plates of the oscilloscope; 7 — branch to the vertical plates of the oscilloscope;
8 — adjusting resistance

Damn.2

Depending on the resistivity of the sample and the sensitivity of the oscilloscope the value of the resistance may be different, but should provide a full sweep of the oscilloscope on the vertical axis.

2.2. Requirements applicable to means of measurement

2.2.1. The probe is made of tungsten or steel wire. The second contact is a metal plate of copper or lead. Ohmic contact is obtained by coating the surface of the sample pin alloy (for example, using lumogallion pencil or indium-gallium paste).

2.2.2. As indicator use a galvanometer with a sensitivity of at least 4·10A/div (for example, type M-195/2, or M-195/3); for monitoring of volt-current characteristics use oscilloscope type S1−5, S1−19, S1−48 or similar. Allowed to use the installations of type TP-101, TP-201.

(Changed edition, Rev. N 1).

2.3. Preparation of ingots

Surface bars should not be visible to the naked eye traces of oxidation or tint. The measurement is permitted on the surface obtained through cutting with a diamond tool or abrasive treatment. For bullion with a specific electric resistance of over 200 Ω·cm is applied to the ohmic contact.

2.4. Determination of type of conductivity

2.4.1. Determination of type of conductivity is carried out at a temperature of (23±2) °C.

2.4.2. The measurements of the ingot includes measuring circuit (Fig.2).

2.4.3. Clamp the probe to the surface of the ingot to achieve the deflection of the null indicator or appears on the screen of the oscilloscope voltage-current characteristics as shown on the devil.3, indicating the presence in the circuit of the rectifying contact.

Damn.3

Damn.3

Type of electric conductivity is adjusted in accordance with the devil.2, 3.

The deflection of the null indicator must be more than 30% of the full scale of the instrument.

The method does not introduce quantitative characteristics.

The characteristic bend of the curves (Fig.3) must not be considered from the quantitative point of view.

2.4.4. When using the method of point-contact rectification with the use of the oscilloscope can’t determine the type of electrical conductivity on the characteristics of rectification, if the characteristic is not bent or is bent twice.

Similar effects can occur due to the presence of -transitions in the material.

3. Qualifications of the operator

Operator qualification shall meet the requirements of measuring electrical parameters of semiconductor materials of the second or higher rank in accordance with the tariff-qualifying collection.

4. Safety requirements

4.1. The device and maintenance of electrical equipment used must meet the requirements of «Rules of technical operation of electrical installations of consumers and safety regulations in the operation of electrical installations», approved by Gaselectronica.

Under the terms of electrical safety of electrical installations, used for measuring type of conductivity apply to electrical voltage up to 1000 V.

5. Terms

Type of conductivity is a qualitative characteristic of semiconductor materials. Depending on the nature of the predominant impurities (donor or acceptor) semiconductor can be electrically (-type) or hole (-type) conductivity. Type of electrical conductivity determines the nature of the main charge carriers in the semiconductor.

APPENDIX 3 (obligatory). MEASUREMENT OF ELECTRICAL RESISTIVITY BY FOUR-PROBE METHOD

APPENDIX 3
Mandatory

The method is designed to measure electrical resistivity on the end surface of monocrystalline silicon ingots from 1·10to 1·10Ohm·cm.

1. The essence of the method

The method is based on calculation of specific electrical resistance for measuring the potential difference at two points located on the flat surface of the ingot, while passing through two point of contact, are located on the same surface, electric current of a certain magnitude.

2. Equipment, measuring devices and materials

Block diagram of equipment for measurement of electrical resistivity is shown in hell.1. The insulation resistance of the installation and all mounting fixtures should not be lower than the required input resistance of the measuring device.

Damn.1. A block diagram of apparatus for measuring electrical resistivity

A block diagram of apparatus for measuring electrical resistivity

1 — by four-probe measuring head; 2 — the constant current source of variable polarity;
3 — a device for measuring the voltage; 4 — ingot

Damn.1

The installation must be certified on standard samples of resistivity, which is included in the State registry of measures and measuring instruments, the maximum value of the total error of less than 5% of the measured value.

2.1. Requirements applicable to means of measurement

2.1.1. Measurement by four-probe type head С2080 with four linearly arranged probes of tungsten carbide;

meisongbei distance =(1,3±0,010) mm

the maximum linear size of the working platform of the probe — not more than 60 microns.

The force probe to the bar and 0.5−2.0 N.

2.1.2. A constant current source, providing the currents measured polarity in the range corresponding to the purpose of the facility.

Permissible variation in electric current during the measurement — not more than 0.5% of its value.

The error of measurement of electrical current — not more than 0.5%.

2.1.3. Measuring device that provides voltage measurement in the range corresponding to the purpose of the installation, when required to properly measure the input resistance.

Measurement error not more than 1.0%.

The limiting values of operating currents and the measured voltages depending on the value of resistivity given in the table.

The upper limit of the measured electrical resistivity , Ohm·cm	The upper limit of the operating currents , And	The upper limit of the measured voltage ,	Input resistance of measuring devices , Ohm, not less
10	1,0·10	1,2·10	1·10
10	1,0·10	1,2·10	1·10
10	1,0·10	1,2·10	1·10
1,0	8,2·10	1,0·10	1·10
10	8,2·10	1,0·10	1·10
10	8,2·10	1,0·10	1·10
10	8,2·10	1,0·10	2·10

When used as a measuring instrument compensating potentiometer input resistance (), Ω, is calculated by the formula

, (1)

where is measured voltage, V;

 — the sensitivity of the galvanometer current, A/mm;

 — the minimum scale of the galvanometer.

The use of semi-automatic potentiometer type R-348 R-349 recommended for those ranges of specific electrical resistance for which the specified in the passport of the potentiometer values for the allowable external resistance are the values recommended by table for input impedance measurement device.

2.1.4. Allowed use of «Metric-104», «Metric-124», «Metrics-224», «Drive-204» and other means of measurement, the characteristics of which meet the requirements of GOST 24392.

(Added, Rev. N 1).

2.2. Materials, equipment

Abrasive materials according to GOST 3647*.
_______________
* On the territory of the Russian Federation c 01.07.2006 will act GOST R 52381−2005. — Note the CODE.

Diamond powder according to GOST 9206.

Diamond tools with the use of diamond powders.

Fabric, wrapping, harsh.

Filters obestochennye.

The blotting paper.

Drinking water technical.

Calico bleached GOST 29298.

Ethyl alcohol according to GOST 18300, according to GOST 5962*.
_______________
* On the territory of the Russian Federation GOST R 51652−2000.

Gauze GOST 9412.

Filter paper according to GOST 12026.

Setup for the measurement of electrical resistivity:

«Metric-104» on the other 25−10 (AMTS.778.019);

«Metric-124» on the other 2−10 (AMTS.778.020);

«Metric-224»;

«Drive-204».

(Changed edition, Rev. N 1).

3. The conditions of measurement

3.1. Measurement of resistivity carried out on the ingots, having at all points the same type of conductivity.

3.2. The measurements were carried out on flat surfaces, having a roughness of not more than 2.5 µm according to GOST 2789.

3.3. When measuring the distance between the edge of the ingot and the closest probe must be at least 5 mm.

3.4. The measurements were carried out at a fixed temperature (23±2) °C.

The temperature of the ingot is adjusted to (23±2) °C, soaking for at least 1 h at this temperature.

3.5. Dimension of ingots with a specific electric resistance in a large 200 Ohm·cm is required to make under the darkening of the ingot. For other ranges of electrical resistivity measurements allowed the illumination of the ingot ambient light 500 Lux.

4. Measurements

4.1. On the prepared surface of the ingot that is installed in the holder, is lowered without hitting the probes of the measuring head perpendicular to the surface.

4.2. Set the amount of current through the ingot (see table) and perform measurements of the voltage drop between the inner probes with two polarities of current.

The value of the measured voltage is defined as the arithmetic mean of measurements at two polarities of the current.

Allowed the measurement at one polarity of current.

5. Processing of the results

Electrical resistivity (), Ω·cm, is calculated by the formula

, (2)

where is the effective distance between the probes of the measuring head, cm, calculated by the formula

, (3)

where , , is the distance between the probes, see

When the measuring head =(1,3±0,010) m in the formula (2) substitute the value ; when the deviation meisongbei ranges of less than 0.010 mm, in the formula (2) substitute the value .

6. Rules on accuracy metrics

6.1. The interval in which there is random error of measurement of electrical resistivity, which characterizes the convergence of the measurements is ±2% with the confidence probability =0,95.

6.2. The interval in which the error of a measurement, that characterizes the reproducibility of measurements in compliance with the requirements of this standard, is ±5% at confidence probability=0,95.

7. Processing of the results

7.1. The result of measuring electrical resistivity () is a value calculated according to the formula (2).

7.2. The measurement result is characterized by the error , if measurements at two polarities of the current, or by repeated measurements within the same region differ by no more than the amount set random measurement error (±2%).

7.3. If there is a difference in measurements with the two current polarities (, ) exceeding ±2% of measured value () if it is established that these differences are not of instrumental origin, the measurements are characterized by the error:

, (4)

where

;

 — random component of the uncertainty equal to 2%;

 — systematic component of error is 3%.

7.4. The measurement results expressed in a three-digit number if the first digit is 1, 2, 3, and double-digit, if first digit is three.

8. Determining the quality of silicon ingots in electrical resistivity

Electrical resistivity is measured at both ends of the ingot of monocrystalline silicon in six fixed points along the diameter of the ingot, in two mutually perpendicular directions in accordance with the devil.2.

Damn.2

Damn.2

According to the results of measurement of resistivity at the two ends of the ingot is calculated:

the average value of resistivity in the peripheral ring of the end:

,

where  — at one end; at the other end;

the average value of resistivity in the center of the end face:

,

where  — at one end; at the other end;

the average value of electrical resistivity at the end:

,

where  — at one end; at the other end;

the radial relative deviation of the resistivity from the average value at the end of the ingot at the end:

%,

where  — at one end; at the other end;

the relative deviation of the average values of electrical resistivity of the ends of the nominal value of the resistivity :

%,

for one end and

,

for the other end.

(Changed edition, Rev. N 1).

9. Qualifications of the operator

Qualification of operator to the extent necessary to perform the measurements must meet the requirements of measuring electrical parameters of semiconductor materials of the third or higher rank in accordance with the applicable tariff and qualification categories.

10. Safety requirements

10.1. The device and maintenance of electrical equipment used must meet the requirements of «Rules of technical operation of electrical installations of consumers and safety regulations in the operation of electrical installations», approved by Gaselectronica.

According to the electrical conditions of the installation used for measuring electrical resistivity, are electrical installations with voltage up to 1000 V.

ANNEX 4 (required). DETERMINATION OF DISLOCATION DENSITY IN SINGLE CRYSTAL INGOTS OF SILICON

ANNEX 4
Mandatory

DETERMINATION OF THE DENSITY OF DISLOCATIONS IN THE SINGLE CRYSTAL
INGOTS OF SILICON

The technique is intended for determining the density of dislocations in monocrystalline silicon ingots of electronic and hole types of conductivity with the electrical resistivity of 0.005 Ohm·cm, orientation (100) and (013), with specific electrical resistance of more than 0.0008 inch Ohm·cm, orientation (111).

The technique is applicable to ingots of silicon with the dislocation density from 0 to 1·10cm. Silicon bestelerini with no more than 10cm.

1. The essence of the method

The number of dislocations is a characteristic of perfection of the crystal.

Methods of identification of dislocations is based on the difference in the speed of etching regions of the ingot with dislocation and without them. At the intersection of dislocations and the surface of the etching rate of the ingot above, resulting in dislocations are identified in the form of etching pits. The definition of the dislocation density is performed on the surface of ingots subjected to selective chemical etching after cultivation or mechanical processing.

2. Reagents, materials and apparatus

Hydrofluoric acid according to GOST 2567, GOST 10484.

Nitric acid according to GOST 11125, GOST 4461, GOST 701.

Chromic anhydride according to GOST 3776, GOST 2548.

Potassium dichromate according to GOST 4220.

Diamond powder according to GOST 9206.

Diamond tools with the use of diamond powders according to GOST 9206.

The particle size fraction used abrasive materials should be not more than 100 µm.

The blotting paper.

Filter paper according to GOST 12026.

Calico bleached GOST 29298.

Libra WLTK or VSC-2 according to GOST 29329.

The beakers, beakers, tongs.

Baths acid.

Grinding machine type LCD 7809 or similar.

The metallographic microscope MIM-type-7 or similar.

3. Preparation of samples to measurements

Control of the dislocation density is on the surface of the ends of the single crystal ingots or on adjacent plates.

3.1. Machining

3.1.1. The measured surface of the ends of single-crystal ingots or wafers processed using special diamond tools. The roughness of the plane should be no more than 2.5 µm according to GOST 2789.

3.1.2. The treated surface washed in running water and dried with filter paper.

3.2. Chemical polishing

Before the selective etching is subjected to the chemical polishing surface of the ends of ingots or plates. The natural surface of the ingot before the selective etching and chemical polishing are not subjected to.

3.2.1. For chemical polishing a solution of the composition: hydrofluoric acid — 1 volume part of nitric acid of 2 to 4 volume parts.

3.2.2. Monocrystalline ingots or plates immersed in a bath with the polishing solution at room temperature.

3.2.3. The volume of the polishing solution is 8−10 ml per 1 g of the processed material. In this case, all subject to the measurement surface should be coated with a polishing solution.

3.2.4. During the polishing, conducting continuous stirring of the solution and the rotation of the sample.

3.2.5. The duration of chemical polishing is 2−10 min.

3.2.6. Upon completion of the polishing of monocrystalline ingots or plate quickly discharged from the polishing solution, washed in running water and dried with filter paper.

3.2.7. You can reuse the polishing solution. The polishing solution, if the etching for 10 min. polishing does not occur.

3.3. Identification of dislocations

3.3.1. Monocrystalline ingots and wafers with orientation (III)

3.3.1.1. To detect dislocations at the ends of the single crystal ingots or on adjacent wafers using a selective Etchant, the composition of which, depending on the initial concentration of hydrofluoric acid is determined by the table.1.

Table 1

Hydrofluoric acid		The volumetric ratio of the components
Concentration, %	Density, g/cm	HF	Aqueous solution CrO	HO
30	1,102	1,5	1	1,5
35	1,116	1,3	1	1,7
40	1,128	1,1	1	1,9
45	1,142	1,0	1	2,0
50	1,155	0,9	1	2,1
55	1,169	0,8	1	2,2
60	1,183	0,75	1	2,25

3.3.1.2. An aqueous solution of chromic anhydride is prepared by dissolving 250 g of chromic anhydride in 1 liter of water.

3.3.1.3. Monocrystalline ingots or plate is immersed in a bath of etching solution at room temperature. The solution volume is 2−4 ml per 1 g of the processed material. In this case, all subject to the measurement surface should be coated with etching solution.

At the same time in the bath, place the sample-Sputnik. Sample-the satellite is subjected to mechanical treatment and chemical polishing before each etching to reveal dislocations. As a model of the satellite can be used any sample of silicon with dislocations detected in the freshly prepared solution.

3.3.1.4. The duration of etching is 10−40 min.

3.3.1.5. Bars or plates, together with a model-companion is discharged from the etching solution, washed in running water and dried with filter paper.

3.3.1.6. The quality of the etching of the measured surface is determined by the definition of revealing dislocations on the sample satellite.

3.3.1.7. You can reuse the etching solution. Etching solution is not suitable for further use, if the etching for 40 min on the sample-the companion is not detected dislocation pattern etching.

3.3.1.8. Allowed to carry out the identification of dislocations in the single crystal ingots or plates (III) in solution:

hydrofluoric acid,

an aqueous solution of potassium dichromate in the ratio (1:1).

3.3.1.9. An aqueous solution of potassium dichromate prepared by dissolving 100−150 g of potassium dichromate in 1 liter of water (70−90 °C).

3.3.1.10. The identification of dislocations is carried out in accordance with subsection.3.3.1.3−3.3.1.9.

(Changed edition, Rev. N 1).

3.3.2. Monocrystalline ingots and wafers with orientation (100)

3.3.2.1. Preparation of monocrystalline ingots and wafers with orientation (100) to identify dislocations is carried out in accordance with PP.3.1−3.2.

3.3.2.2. The identification of dislocations is carried out in a selective Etchant, the composition of which, depending on the initial concentration of hydrofluoric acid is determined by the table.2.

Table 2

Hydrofluoric acid		The volumetric ratio of the components
Concentration, %	Density, g/cm	HF	An aqueous solution of CrO	HO
35	1,116	8	1	1
40	1,128	7	1	2
45	1,142	6	1	3
50	1,155	5,5	1	3,5
55	1,169	5	1	4
60	1,183	4,5	1	4,5

3.3.2.3. An aqueous solution of chromic anhydride is prepared by dissolving CrO 250−300 gin 1 l of water.

3.3.2.4. The identification of dislocations is carried out in accordance with subsection.3.3.1.3−3.3.1.7.

(Changed edition, Rev. N 1).

3.3.2.5. (Deleted, Rev. N 1).

4. Measurements

The calculation of the dislocation density is carried out using the metallographic microscope.

The recommended magnification of the microscope, depending on the dislocation density is defined according to table.3.

Table 3

The dislocation density, cm	Increase
0−5·10	40−60
5·10-1·10	60−80
1·10-5·10	80−120
5·10-1·10	120−170
1·10-5·10	170−350
5·10-1·10	350−600

The surface to be measured scan in two mutually perpendicular directions nine fields of view and determine the number of dislocation etch pits in each of them. The location of fields of view to determine density of dislocations at the ends of ingots or plates are given in table.4. The scheme of selection of fields of view to determine density of dislocations shown in hell.2.

Table 4

The location of fields of view for control of the dislocation density on the ends
single-crystal ingots or on wafers

The diameter of sample, mm	Distance of measurement points from the edge of the sample, mm
	1 and 6	2 and 7	3	4 and 8	5 and 9
30,0	3,1	7,2	15,0	22,8	26,9
31,0	3,1	7,4	15,5	23,6	27,9
32,0	3,2	7,6	16,0	24,4	28,8
33,0	3,2	7,8	16,5	25,2	29,8
34,0	3,3	8,0	17,0	26,0	30,7
55,0	4,6	12,8	27,5	42,6	50,4
56,0	4,7	12,6	28,0	43,4	51,3
57,0	4,7	12,8	28,5	44,2	52,3
58,0	4,8	13,0	29,0	45,0	53,2
59,0	4,9	13,3	29,5	45,7	54,1
60,0	4,9	13,5	30,0	46,5	55,1
61,0	5,0	13,7	30,5	47,3	56,0
62,0	5,0	13,9	31,0	48,1	57,0
63,0	5,1	14,1	31,5	48,9	57,9
64,0	5,2	14,3	32,0	49,7	58,8
65,0	5,2	14,5	32,5	50,5	59,8
66,0	5,3	14,7	33,0	51,3	60,7
67,0	5,3	14,9	33,5	52,1	61,7
68,0	5,4	15,2	34,0	52,8	62.6 per
69,0	5,5	15,4	34,5	53,6	63,5
70,0	5,5	15,6	35,0	54,4	64,5
71.0 per	5,5	15,8	35,5	55,2	65,4
72,0	5,6	16,0	36,0	56,0	66,4
73,0	5,7	16,2	36,5	56,8	67,3
74,0	5,8	16,4	37,0	57,6	68,3
75,0	5,8	16,6	37,5	58,4	69,2
76,0	5,9	16,8	38,0	59,2	70,1
77,0	5,9	17,0	38,5	60,0	71,1
78,0	6,0	17,3	39,0	60,7	72,0
79,0	6,1	17,5	39,5	61,5	72,9
80,0	6,1	17,7	40,0	62,3	73,9
81,0	6,2	17,9	40,5	63,1	74,8
82,0	6,2	18,1	41,0	63,9	75,8
83,0	6,3	18,3	41,5	64,7	76,7
84,0	6,4	18,5	42,0	65,5	77,6
85,0	6,4	18,7	42,5	66,3	78,6
86,0	6,5	18,9	43,0	67,1	79,5
87,0	6,5	19,1	43,5	67,9	80,5
88,0	6,6	19,4	44,0	68,0	81,4
89,0	6,7	19,6	44,5	69,4	82,3
90,0	6,7	19,8	45,0	70,2	83,3
91,0	6,8	20,0	45,5	71.0 per	84,2
92,0	6,8	20,2	46,0	71,8	85,2
93,0	6,9	20,4	46,5	72,6	86,1
94,0	7,0	20,6	47,0	73,4	87,0
95,0	7,0	20,8	47,5	74,2	88,0
96,0	7,1	21,0	48,0	75,0	88,9
97,0	7,1	21,2	48,5	75,8	89,9
98,0	7,2	21,4	49,0	76,6	90,8
99,0	7,3	21,7	49,5	77,3	91,7
100,0	7,3	21,9	50,0	78,1	92,7

5. Processing of the results

5.1. According to the measurement results calculate the average value of the number of etch pits in sight

, (1)

where is the number of pits in the field of view;

 — the number of fields of view.

5.2. The dislocation density is calculated by the formula

, (2)

where  — the scalar factor determined by the magnification of the microscope.

5.3. Scalar coefficient determined by the formula

,

where  — area of the field of view defined by the magnification of the microscope, cm.

5.4. The area of the field of view is determined by objectmaker attached to the microscope.

6. Processing of measurement results

6.1. The result of measuring the dislocation density is a value calculated according to the formula (2).

6.2. The error of the measurements is ±50% with the confidence probability =0,95.

6.3. The results represent two significant digits, multiplied by the order of the determined values of the dislocation density (for example, a 2.2·10cm).

7. Qualifications of the operator

Qualification of operator in the amount necessary to perform measurement this method shall meet the requirements of measuring electrical parameters of semiconductor materials of the third or higher rank in accordance with the current tariff-qualification Handbook.

8. Safety requirements

When working in chemical laboratories major precautions also apply to storage of reagents, dilution solutions, acids, alkalies, their use in chemical etching in a cold and heated state.

Work with chemicals should be carried out in accordance with the «Basic rules of safety work in the chemical laboratory».

9. Terms and definitions

9.1. Dislocation — a linear structural defect, which limits the area of the shift, or the defect of the packing within the crystal.

9.2. Hole etching of dislocation — cavity obtained by the selective etching, resulting in the exit of dislocations on the crystal surface, the shape and cut of which depends on the symmetry surface (Fig.1).

Damn.1. Dislocation etching pits

Dislocation etching pits;
increase 225

the plane (111); b — plane (100)

Damn.1

9.3. A selective etching and chemical or electrochemical etching, wherein removal of the material of the crystal in the defect area and defect-free matrix occurs in different ways.

9.4. The surface dislocation density — the number of dislocations that intersect a unit area of a surface section of the crystal, determined by counting the dislocation etch pits.

9.5. Ingot — products for the production of semiconductor materials obtained as a result of the growing process.

9.6. Natural crystal surface, the crystal surface formed as a result of cultivation.

9.7. Machined surface — to-surface or portions of the ingot subjected to treatment with a diamond tool.

9.8. The end — section of the ingot perpendicular to the growth direction.

9.9. Sample-Sputnik — plate, structure or other object participating in the technological process of manufacturing of these products used to measure any parameter.

Damn.2. The scheme of selection of fields of view

The scheme of selection of fields of view

Damn.2

APPENDIX 5 (mandatory). MEASUREMENT OF THE DEFLECTION ANGLE OF THE PLANE END OF THE CUT SINGLE CRYSTAL SILICON INGOT FROM A GIVEN CRYSTALLOGRAPHIC PLANE AND IDENTIFICATION OF THE CRYSTALLOGRAPHIC ORIENTATION OF THE PLANE FACE OF THE SLICE INGOT WITH A GIVEN

ANNEX 5
Mandatory

MEASUREMENT OF THE DEFLECTION ANGLE OF THE END PLANE OF THE SLICE
MONOCRYSTALLINE SILICON INGOT FROM THE SPECIFIED
THE CRYSTALLOGRAPHIC PLANE AND IDENTIFICATION
THE CRYSTALLOGRAPHIC ORIENTATION OF THE PLANE OF THE END
SLICE OF THE INGOT WITH A PREDETERMINED CRYSTALLOGRAPHIC PLANE
X-RAY DIFRACTOMETRIC METHOD

A. Measurement of the angle of deviation and identification of the crystallographic orientation on the plate (washer)

The method is designed to measure the angle of deviation of the plane end of the cut single crystal silicon ingot from a given crystallographic plane and identification of the crystallographic orientation of the plane face of the slice with a given crystallographic plane () on the plate, cut parallel to the plane face of the slice.

The technique spread to the bars of cylindrical and arbitrary shaped diameter (or linear dimensions) the plane of the end cut of more than 20 mm.

The technique is applicable in the range of deflection angles to the plane face of the slice from a given crystallographic plane is not more than 5 degrees for the orientation (111) and (100) and not more than 3 degrees for orientation (013).

1. The essence of the method

1.1. The method is based on using the phenomenon of diffraction of the characteristic x-ray radiation in single-crystal sample.

For crystals of cubic symmetry the slip angle (the angle between incident on a single crystal sample by the primary x-ray beam and the reflecting crystallographic plane ()) is calculated according to the formula

, (1)

where is the period lattice of the single crystal sample, nm;

 — wavelength of the characteristic radiation, nm;

 — Miller indices crystallographic plane;

 — the order of reflection.

1.2. Check the intensity of the reflected (diffracted) radiation is carried out using the x-ray detector that is installed under the double slip angle to the primary beam.

1.3. The geometric plane of the plate (washer) combine with a rotation axis of the goniometer. The primary beam is directed at the wafer surface. The plate is rotated around the axis of roentgenogrammetry as long as a plane () will not make the slip angle () with the primary beam. When this occurs, the reflected (diffracted) single crystal plate, the beam, which is detected by the detector of x-ray quanta. The angular position of the plate (), the corresponding maximum intensity of the reflected beam, measured on a scale of roentgenogrammetry.

1.4. The angle of deviation of the geometric plane of the plate from a given crystallographic plane () is calculated by the formula

, (2)

where , , , values of angles at different azimuthal positions of the plate with different rotation angles 0°, 90°, 180° and 270° around the normal to the geometric plane of the plate.

1.5. The angle of deflection of a geometric plane face of the slice ingot is determined in accordance with sub.1.1−1.4 on the plate, cut parallel to the plane face of the slice.

1.6. The crystallographic orientation of the plane face of the slice considered identical to a given crystallographic plane () (see table). if the corner does not exceed the values specified in the technical requirements for the material.

If the angle of deflection () exceeds allowable values, and in the absence of the reflected sample beam under the conditions of the PP.1.2 and 1.3 in the two azimuthal positions of the sample, differing by 90°, the crystallographic orientation of the plane face of the slice is not identical to a given crystallographic plane.

The angles for some crystallographic planes ()
monocrystalline silicon (Cu Kradiation, =0,15406 nm)
(1,5406), =0,5431 nm (5,431)

The indices of the crystallographic plane	(111)	(100)	(013)
The indices of reflections	111	400	026
Slip angle	14°13'	34°33'	63°48'

2. Equipment, measuring instruments, materials

X-ray equipment types URS-50ИМ; DRON-2, DRON-3M, installation and other measuring tools, not inferior to the listed technical and metrological specifications and certified by the NSI with the absolute error of the orientation measurement on standard samples of less than ±8 angular minutes.

Machines for cutting with the inner cutting edge types «Almaz-6», «Diamond-4» or other similar machines, are no less technical and metrological characteristics.

The multi-turn indicator according to GOST 9696.

Flat, table C-III according to GOST 10197.

Protractor.

Steklograf (pencil).

Filter paper according to GOST 12026.

The blotting paper.

3. The preparation of the measurements

3.1. Installation prepare and test in accordance with the attached instructions.

Set the scales of the goniometer for sample — slip angle and for the detector — dual slip angle, corresponding to given crystallographic planes given in the table.

Set the mode of operation: the tube voltage 10−25 kV; anode current of 1−5 mA.

In the collimator of the goniometer, set the vertical gap # 1 and 2 with a width of 0.1 mm, each (when using SSE).

Check the correct alignment of the optical scheme of x-ray units using a standard sample (plate corresponding to the orientation () with an error of no more than 3).

3.2. The measurements were carried out on plates cut as specified in claim 1.5, a thickness of 0.5 to 20 mm. On the plate indicates the side facing the cut end of the ingot and the target crystallographic orientation of the plane face of the slice ingot from which the cut plate.

The plate cut from the plane face of the slice ingot, before the measurement sand the impossible.

4. Preparation of the plate to dimensions

The plate was washed with water, then dried with filter paper. On the surface of the plate applied to a rectangular coordinate system using the protractor and pencil.

5. The conditions of measurement

5.1. For measurements the following are required:

ambient temperature 10 to 35 °C;

relative humidity not more than 80% at 25 °C.

5.2. Other conditions of measurement shall conform to the requirements set forth in the certificate on metrological certification of measuring instruments.

6. Measurements

6.1. Include installation, set the operating mode.

The plate is mounted on the console using a goniometer (sample holder) so that the surface to be measured was pressed against the base plane of the sample holder, and the axis «a» parallel to the horizontal plane of diffraction and is directed toward the detector.

6.2. The voltage applied to the x-ray tube, and to open the tonneau covers of the primary beam.

6.3. The rotating holder with the sample around the axis of the goniometer to an angle , looking for a position where the reflected beam occurs.

In the absence of the reflected beam turn the plate 90° from its original position and again trying to get the reflection of the rotating plate around the axis of the goniometer to an angle . The lack of reflection and in this position of the plate means non-identity of the crystallographic orientation of the plane face of the slice ingot with a given crystallographic plane.

6.4. Close the tonneau covers of the primary beam (or remove voltage from the x-ray tube in the absence of the cover).

6.5. In the presence of the reflected beam output plate in a position of maximum reflection by rotating it around the axis of the goniometer to an angle . Then perform the operation as specified in clause 6.4.

6.6. The value of the angle is determined by the scale of the sample goniometer.

6.7. The plate is rotated 180° relative to the position specified in item 6.1 by rotating it around the normal to the surface, and repeat the operations specified in the claims.6.2, 6.4 and 6.5.

6.8. The value of the angle is determined by the scale of the sample goniometer.

6.9. The plate is installed in the console using a goniometer (sample holder) so that the surface to be measured was pressed against the base plane of the sample holder and the axis of the «» was directed towards the detector and parallel to the plane of diffraction, and then repeat the operations indicated in the claims.6.2, 6.4 and 6.5.

6.10. The value of the angle is determined by the scale of the sample goniometer.

6.11. The plate is rotated 270° relative to the position specified in item 6.1 by rotating it around the normal to the surface, and repeat the operations specified in the claims.6.2, 6.4 and 6.5.

6.12. Define the angle value on the scale of the sample goniometer.

7. Processing of the results

7.1. Calculate the value of the angle of orientation of the plane of the face of the slice ingot from a given crystallographic plane () according to the formula (2).

7.2. Carry out the identification of the crystallographic orientation of the plane face of the slice with a given crystallographic plane in accordance with the requirements of paragraph 1.6.

7.3. For the measurement of the deflection angle of the plane face of the slice from a given crystallographic plane () take the amount calculated according to the formula (2).

7.4. The error of measurement shall not exceed 20 minutes of arc with the confidence probability =0,95.

8. Qualifications of the operator

Operator qualification necessary to perform measurements according to this method, must meet the qualifications of the research rentgenostrukturnyi fourth category or a higher category of «Uniform tariff-qualifying directory of works and professions of workers».

9. Safety requirements

11.1 the structure and technical operation of the equipment used in accordance with this methodology shall meet the requirements of «Rules of technical operation of electrical installations of consumers and safety regulations in the operation of electrical consumers».

11.2. The structure and technical operation of x-ray equipment used in accordance with this methodology shall meet the requirements of «the Main sanitary rules when working with radioactive substances and other sources of ionizing radiation» and «radiation safety Standards».

B. Measurement of angle of deviation and identification of the crystallographic orientation of the ingot

The method is designed to measure the deflection angle of the end plane of the slice of monocrystalline silicon ingot of a cylindrical shape from a given crystallographic plane and identification of the crystallographic orientation of the plane face of the slice ingot with a given crystallographic plane ().

The technique applies to ingots having a cylindrical shape with diameter of grounds from 11.5 mm to 100 mm and length from 50 mm to 400 mm. it is assumed that the geometrical axis of the ingot parallel to a generatrix of the cylinder.

The technique is applicable in the range of deflection angles to the plane face of the slice from a given crystallographic plane ±5° to the crystallographic orientation (111) and (100) and ±3° for the crystallographic orientation (013).

1. The essence of the method

1.1. The method is based on the combined use of the diffraction phenomenon of x-ray characteristic radiation in single-crystal sample, which is the case when the condition (1), and mechanical measurement of the constituents and (damn.1) angle to the plane face of the slice ingot from the hypothetical plane normal to the geometrical axis of the ingot.

Damn.1. A stereographic projection of the location of the geometrical axis of the ingot, the crystallographic axis and the normal to the plane face of the slice ingot

A stereographic projection of the location of the geometrical axis of the ingot (),
the crystallographic axis [] () and the normal to the plane face of the slice ingot ()
in the azimuthal coordinate «»

Damn.1

1.2. The phenomenon of diffraction is used to measure the angle of deviation of the geometrical axis of the single crystal ingot, having the shape of a cylinder, from the crystallographic direction [], which is perpendicular to a given crystallographic plane () for cubic crystal structure, which includes monocrystalline silicon. In the future, [] will be called the specified crystallographic direction (see the devil.1).

1.3. Check the intensity of the reflected (diffracted) radiation is carried out using the x-ray detector that is installed under the double slip angle to the primary beam.

1.4. The ingot set in the holder so that its geometrical axis is parallel to the reference direction of the holder perpendicular to the axis of rotation of the goniometer. The basic direction of the holder mean the axis defined prismatic surface of the holder, which put the ingot.

In this case, the hypothetical plane of the ingot, normal to its geometrical axis coincides with the vertical plane containing the axis of rotation of the goniometer.

The primary beam is directed at the plane face of the slice ingot and rotates the holder with the ingot around the axis of roentgenogrammetry until, until the condition of diffraction (1). When this occurs, the reflected (diffracted) single-crystal ingot, a beam, which is detected by the x-ray detector. The angular position of the single crystal ingot (relative to the direction of the primary beam) corresponding to the maximum intensity of the reflected beam, measured on a scale of roentgenogrammetry. When the geometrical axis of the ingot coincides with the predetermined crystallographic direction.

1.5. The deflection angle of the geometrical axis of ingot from the specified crystallographic direction () or equal to the deflection angle of the hypothetical plane of the ingot, normal to the geometrical axis, from a given crystallographic plane with the same indexes () is calculated by the formula

,

where , values of angles at different azimuthal positions of the ingot, wherein the rotation angle of 90° around its geometrical axis (see the devil.1).

1.6. The ingot is set in a device for measuring angles and between the normal to the geometric axis of the ingot and the plane end of the cut so that the geometrical axis of the ingot parallel to the reference direction of the holder, and azimuthal position, wherein a twist angle of 90° around its geometrical axis (see the devil.1), coincided with the corresponding azimuthal provisions indicated in claim 1.5, and using the time the micrometer indicator measure angles (90°-) and (90°-a) between the geometric axis of the ingot and the corresponding azimuthal diameter (or ) end of the slice of the ingot.

1.7. Angle  — the angle of deviation of the plane face of the slice ingot from a given crystallographic plane () is calculated by the formula

, (3)

where and are the components of the deflection angle of the plane of the face of the slice ingot from a given crystallographic plane (or normal to the plane face of the slice ingot from the normal to a given crystallographic plane) to hell.1 and 2 at the same azimuthal positions of the ingot as in claim 1.5.

; (4A)

. (4B)

Damn.2. A stereographic projection of the mutual arrangement of the crystallographic axis and the normal to the plane face of the slice ingot

A stereographic projection of the mutual arrangement of the crystallographic axis []
and the normal to the plane face of the slice ingot

Damn.2

1.8. The crystallographic orientation of the plane face of the slice is identical to a given crystallographic plane, if the angle does not exceed the values specified in the technical requirements for bullion.

If the angle exceeds the permissible value, and in the absence of the reflected monocrystalline ingot beam in compliance with PP.1.3 and 1.4 at two azimuthal positions of the sample, differing by 90°, the crystallographic orientation of the plane face of the slice ingot is not identical to a given crystallographic plane.

1.9. Allowed to measure the deviation of the geometrical axis of ingot from the specified crystallographic direction () (and ) the departure of the plane face of the slice from the normal to geometrical axis of ingot (and ) on the same holder with prismatic surface.

2. Instrumentation, measurement, materials

The x-ray diffractometer types URS-60; DRON-2, DRON-3; DRON-3M according to GOST 24745−81 complete with certified non-standardized attachments-specimen holders and fixtures, providing measurement of angles and on the PP.1.5 and 1.6, and other measuring instruments (including certificated NSI), which provide absolute measurement error of the angle of deviation of the geometrical axis of ingot from the specified crystallographic directions ±8 angular minutes.

The sample standard orientation. Allowed the use of SOPS. Absolute error of establishing certified characteristics of ±4 arc minutes.

Exemplary cylindrical square for alignment, measuring angles according to claim 1.6. The error of the certified characteristics of 30 µm at a length of 100 mm.

A protractor, a compass to measure the azimuth directions for PP.1.5 and 1.6.

Steklograf (pencil).

Gauze GOST 11109, GOST 9412.

3. The preparation of the measurements

3.1. X-ray machine to determine the crystallographic orientation of the ingots prepared to work in accordance with the relevant instructions.

3.2. Set the operation mode: rated tube voltage of 10−25 kV, anode current — 1 to 5 And*.
_______________
* Unit conforms to the original. — Note the CODE.

3.3. With a sample standard orientation they control the alignment of the optical installation scheme.

The order of operations to the instruction manual.

3.4. Using the instructions to install x-ray to determine the crystallographic orientation of the ingots, check the correct alignment of the goniometer and set-top boxes using a standard sample.

3.5. In accordance with the table set on the scale of the goniometer for sample slip angleand for the detector — slip angle corresponding to the reflection from the plane (), and radiation (=0,15406 nm).

3.6. Using the exemplary cylindrical gon perform control of adjustment of the measuring angle according to claim 1.6. The order of operations to the instruction manual.

3.7. Preparation of ingots.

Washed the butt end of the ingot with water and dry it using filter paper.

At the ends of the ingot applied with a pencil or steklografom rectangular coordinate system with a protractor or special template. The axes and planes of both end sections of the ingot shall be respectively parallel, and the directions of the axes differ by 180°. Put on the ends of digits I and II. In the case that measurement of angles and are performed on the same holder (see p.1.9), the azimuthal direction and is applied to one end

.

4. Condition measurements — see section A, paragraph 5.

5. Measurements

5.1. Determination of the angles and between the plane face of the slice ingot and a hypothetical plane normal to its geometrical axis.

5.1.1. Set ingot holder fixture (see p.1.4) so that the axis of the ingot parallel to the reference direction of the holder , and the axis marked on the end planes of the slice of the ingot, parallel to the azimuthal directions defined by the measuring nodes. The positive directions of axes at the first end (marked with I) should be directed upwards and the second downwards.

5.1.2. Pressed against the ingot in position (see p.5.1.1) to the stops of the measuring unit (see p.1.6).

Record the indicator reading (microns).

5.1.3. Repeat the requirements of clause 5.1.2 — in position . Record the reading (microns).

5.1.4. Repeat the requirements of the PP.5.1.2 and 5.1.3 related to the plane of the end section (II) of the ingot to the ingot in position and . Write the relevant testimony , and (µm).

5.1.5. Calculate the corresponding values of azimuth and angle of the end planes of the slice of the ingot from the hypothetical plane normal to the axis of the ingot by the formulas:

; (5A)

; (5B)

; (5V)

, (5g)

where fixed for this device the distance between the axis of the abutment and movable axis of the indicator, µm, (see PP.1.4−1.6).

5.2. Determination of the angles and the deviation of the geometrical axis of ingot from the specified crystallographic directions [].

5.2.1. Set the ingot on the prismatic surface of the holder bars so that the plane of its end cut II concerned the focus (see p.1.4), and the positive axis direction on the plane face of the slice I pointed to the direction of the primary beam.

5.2.2. The voltage applied to the x-ray tube, and to open the shutter in the primary beam.

5.2.3. Rotating console with ingot around a vertical axis goniometer, find the position of the console relative to the direction of the primary x-ray beam corresponding to the maximum intensity of the reflected x-ray beam.

5.2.4. Close the shutter of the primary beam (or remove voltage from the x-ray tube in the absence of the cover).

5.2.5. Recording an indication of the scale of roentgenogrammetry corresponding to the angle of rotation of the console relative to the direction of the primary beam.

5.2.6. Change the position of the ingot in the console by turning it around its axis by 180°, repeat the requirements of the PP.5.2.3−5.2.5 and record the corresponding angle value .

5.2.7. Change the position of the ingot in the console by turning it around its axis by 90° in any direction.

5.2.8. Fulfill the requirements of the PP.5.2.2−5.2.5 to determine the corresponding values of the angles and .

5.2.9. Calculates the values and formulas:

Time; (6A)

. (6b)

5.2.10. Calculated values and (according to the formulas 4A, b) for the first (I) and second (II) ends, respectively.

5.3. When measuring angles and on the same holder (see p.1.9) the sequence of operations change. In the position of the ingot (see PP.5.1.2, 5.2.1) is measured , and in accordance with the requirements of paragraphs.5.1.2, 5.1.4, 5.2.1−5.2.8, but in the position of the ingot are measured, respectively , and in accordance with the requirements of paragraphs.5.1.3, 5.1.4, 5.2.7.

6. Processing of the results

6.1. The value of the deflection angle of the plane of the end sections of the ingot from a given crystallographic plane is calculated by the formula 3. (Calculations according to equations 2−5 can be performed using the relevant tables).

6.2. For the result of the measurement of the deflection angle of the end plane of the ingot from a given crystallographic plane () take the value calculated according to claim 1.7.

6.3. The error of angle measurements should not exceed ±20 angular minutes with a confidence level .

6.4. The identification of the crystallographic orientation of the plane face of the slice with a given crystallographic plane is carried out in accordance with the requirements of paragraph 1.8.

7. Qualifications of the operator — see section A, item 10.

8. Safety requirements — see section A, paragraph 11.

(Changed edition, Rev. N 1).

APPENDIX 6 (mandatory). DETERMINATION OF THE DEFLECTION ANGLE OF THE END PLANE OF THE SLICE FROM A GIVEN CRYSTALLOGRAPHIC PLANE OF SINGLE CRYSTAL SILICON INGOTS USING AN OPTICAL METHOD

APPENDIX 6
Mandatory

The technique is intended for determining the deflection angle of the plane face of the slice from a given crystallographic plane.

1. The essence of the method

Reflected from the end face of the ingot linear light beam forms on the screen a luminous figure, the location where you can define the angle of deviation of the plane of the slice from a given crystallographic plane.

(Changed edition, Rev. N 1).

2. Equipment and materials

Installation ЖК78 intended for guiding an optical method of monocrystalline ingots.

The accuracy of the orientation of monocrystalline silicon ingots ±30°.

Abrasive materials according to GOST 3647*.
_______________
* On the territory of the Russian Federation c 01.07.2006 will act GOST R 52381−2005. — Note the CODE.

Diamond powder according to GOST 9206.

Diamond tools with the use of diamond powders according to GOST 9206.

The particle size fraction used diamond powders should be no more than 100 microns.

Sodium hydroxide 2263 according to GOST, GOST 11078.

Potassium hydroxide (technical) according to GOST 9285.

3. Preparation for measurement

3.1. Preparation of ingots

The end face of the ingot is polished with abrasive material, diamond powder or diamond tool.

On the polished surface are not allowed chips, ledges and cracks.

A polished end face of the ingot is etched for 3−5 minutes in a boiling solution of KOH or NaOH with a concentration of not less than 20%.

3.2. Installation preparation

The zero position of the plane of the stage check with a test mirror, is placed on this plane. When checking the output light spot in the cross-hairs on the screen using a pen goniometric head.

4. Measurements

4.1. To set the ingot a controlled end to the opening in the plane of the stage.

4.2. To rotate the ingot to the center of the light a figure appeared on the horizontal or vertical scale of the cross hair screen.

4.3. Rotating limb azimuth head to combine the center of light of the shape with a crosshair on the screen.

4.4. Count on the limb angle of the deflection plane of the slice (end) from given crystallographic plane. You can define the deflection angle directly on the scale of the screen, knowing the price of division of the linear scale into angle values.

5. Indicators of measurement accuracy

5.1. When using the equipment recommended in sect.2, and the conditions of preparation and measurement (sect.3, 4), the error in determining the orientation of an ingot .

6. Qualifications of the operator

6.1. Qualification of operator to the extent necessary to perform the measurements must meet the requirements of measuring electrical parameters of semiconductor materials of the third or higher rank of the current collection of tariff and qualifying works.

7. Safety requirements

7.1. The device and maintenance of electrical equipment used must meet the requirements of «Rules of technical operation of electrical installations of consumers and safety regulations in the operation of electrical consumers».

Under the terms of electrical safety of electrical systems used for optical orientation of silicon ingots, are electrical installations with voltage up to 1000 V.

ANNEX 7 (obligatory). MEASUREMENT OF THE CONCENTRATION OF OPTICALLY ACTIVE ATOMS OF OXYGEN IN THE INGOTS OF MONOCRYSTALLINE SILICON

ANNEX 7
Mandatory

This methodology is designed to measure the concentration of optically active oxygen () in ingots of monocrystalline silicon grown by Czochralski methods (MCH) or floating zone zone melting (BZP).

Be measured ingots are allowed to be subjected to heat treatment at temperatures above 750 °C and duration 3 hours, max.

Measurements can be done more efficient or more accurate absolute differential optical methods.

The differential method is applicable for determining from at least 1·10to 3·10at·cmingot grown at «MCH» with specific electrical resistance (resistivity) is not less than 0.04 Ω·cm with electronic type of conductivity (a-Si) and in ingots with resistivity not less than 1 Ohm·cm p-type conductivity (a-Si) ingots grown by the method of BZP, determine the interval of less than 2·10to 8·10at·cmin resistivity more than 20 Ohm·cm (a-Si) and with resistivity of 50 Ω·cm (a-Si).

The absolute method is applicable to determine in ingots grown only «MCH» (-Si) with resistivity of 50 Ω·cm, and (-Si) with resistivity of 20 Ohm·cm.

1. The essence of the method

The presence of optically active oxygen atoms in silicon leads to the appearance of absorption bands in the region of wavelengths close to 9.1 microns (wave number 1105 cm). In this region of wavelengths available and the absorption band of the crystal lattice of the silicon absorption coefficient at the maximum =0,92 cm. The absorption in this region of the spectrum can be caused by free charge carriers.

The concentration of optically active oxygen is proportional to its absorption coefficient in the maximum oxygen band . The value determined from optical measurements performed in absolute or differential methods.

The absolute method is based on measurement of transmittance spectrum of sample () in the region of wavelengths close to 9.1 µm, accounting for the absorption by the crystalline lattice in calculation of measured () and used to determine the in Vysokomol material, when the absorption by free charge carriers can be neglected.

Differential method eliminates the influence of light absorption by the crystalline lattice of silicon and the free charge carriers in the measurement . It is based on the measurement curve relative to the transmission by comparing the transmission spectra of the measured sample and reference sample that is placed in two-channel double-beam spectrophotometer.

2. Equipment, measuring devices and materials

Types of spectrophotometer «Specord-75 IR», «Perkin-Elmer-983», «X-29» or any dual-beam spectrophotometer measurement with an optical slit width of not more than 5 cmand the absolute error of measurement of transmittance of not more than 0,012 at standard measurements.

The multi-turn indicator according to GOST 9696 or indicator of the same type with a measuring error of more than 0.001 cm

Powders abrasive grinding M28, M14, M7 according to GOST 3647* and GOST 9206.
_______________
* On the territory of the Russian Federation c 01.07.2006 will act GOST R 52381−2005. — Note the CODE.

Diamond paste ASM 1/0 according to GOST 25593.

Rectified ethyl alcohol according to GOST 17299, GOST 18300.

Hydrofluoric acid according to GOST 10484, technical, or H. h

Nitric acid according to GOST 4461, h.d. a.

Acetic acid according to GOST 61, H. h

Potassium bromide according to GOST 4160, h. h. or h.d. a.

Batiste bleached GOST 29298.

The reference sample.

3. The conditions of measurement

The measurement is carried out at a temperature of (20±5) °C, other conditions in accordance with the requirements of GOST 12997.

4. Preparation and measurements

4.1. Sample preparation

4.1.1. From the study of single-crystal silicon ingot is cut parallel to the sample (the puck).

4.1.2. The sample is polished on both sides and polished with diamond paste ASM-1 to obtain a surface free of scratches and scratches. Instead of mechanical polishing allowed chemical etching the polished surface in one of the polishing etchants of the SR-4 or SR-8 until the brown fumes.

4.1.3. Cross section of the specimen must be greater than the cross section of the working beam of the spectrophotometer or used to measure microasperities device.

For measuring oxygen concentration in small samples and for measuring the distribution in the sample section allowed workers aperturing beam spectrophotometers. The influence of the size of the diaphragms on the weekend passport characteristics of the spectrophotometer to check the experimental-industrial testing, measuring or examination of the spectrophotometer and repeat for the inspections of the spectrophotometer at least once a year. The size of the holes in the diaphragms must be such that the introduction of the diaphragm does not impair any of the passport characteristics of the spectrophotometer.

4.1.4. The reference sample is chosen so that its specific resistance a-Si (a-Si) was more than 20 Ohm·cm (50ω·cm) when measured in a-Si with more than 20 Ω·cm and a-Si with more than 50 Ohm·cm When measured in a-Si; C =0,04−20 Ω·cm or Si; C =1−50 Ohm·cm electrical resistivity of the reference sample must be greater than or equal to the electrical resistivity measured on

a sample of the.

4.1.5. Before measurement, the polished samples surface carefully wiped with ethanol.

4.1.6. The thickness of the test specimen is measured at four points on two arbitrary, mutually perpendicular directions on the perimeter of the select area that will be covered by the working beam of the spectrophotometer. The measured values should not differ from each other by more than ±0,002 cm

To measure the absolute method the thickness of the samples should be greater than 0.2, see

To measure the differential method, all values of the thickness of the measured sample and reference sample must be in the range of 0.20−0.25 cm for the expected values of at least 2·10at·cm(for ingots grown by the method (MCH)) and 0.95 to 1.00 cm for values in the range 8·10<2·10at·cm(for ingots grown by the method of (BZP)), and should not differ by more than 0,00

4 see

4.2. Preparation of the spectrophotometer for measurements

Prepare the spectrophotometer for measurements according to instructions.

4.3. Measurement of the curve of the relative transmittance of the absolute method

4.3.1. Write a 100% line in the region of wave numbers =1000−1400 cm. If the change in 100% line is greater than the tolerance provided in the specification of the device, the spectrophotometer must be calibrated.

4.3.2. Set the measured sample in the holder.

4.3.3. Record the transmission spectrum of the sample in the region of wave numbers of 1000−1400 cmmode, which provides lack of distortion of the shape of the absorption bands of oxygen introduced by the spectrophotometer. The recommended modes of operation for the type of spectrophotometer «Specord-75 IR» in the table.

The recommended measurement mode for dual beam type spectrophotometer «Specord-75 IR».

Method of measurement	Write speed, cm/min	Slit program	The scale of registration, mm/100 cm	Strengthening	Time constant	Duration tions of the record, min/sheet
Absolute	Not specified	3	50	2−3	10	11
Differential	The same					4,4x10

4.4. Measurement of the curve of relative differential transmission method.

4.4.1. Before each series of measurements, but not less than once per shift, record the 100% line in the region of wave numbers =900−1400 cm. If the change in 100% line is greater than the tolerance provided in the specification of the device, the spectrophotometer must be calibrated.

4.4.2. In the channel of the sample beam of the spectrophotometer set to the measured sample, and the channel comparison — sample comparison.

The correct choice of recording speed spectrum and a slit program of the spectrophotometer test in two ways:

a) control the half-width of absorption bands of oxygen, which should not exceed 35 cm. The half-width of the absorption bands is equal to half the maximum value of the absorption coefficient of oxygen ;

b) check the reduction of the coefficient of relative transmittance in the differential measurements in the minimum of the absorption band of oxygen at a further decrease in recording speed.

4.4.3. If in the short wavelength region of the measured spectral range (at wave speed =1300 cm) the instrument reading is between 90 and 100%, the curve relative to the transmission in the area =900−1400 cmin write mode, ensuring the absence of distortions of the shape of the absorption bands of oxygen introduced by the spectrophotometer. Recommended operation modes type spectrophotometer «Specord-75 IR» in the table. During measurements in the field =1200−1400 cmrecording time can be reduced (write speed increased), but not more than three times.

4.4.4. If in the short wavelength region of the measured spectral range the instrument reading is not between 90 and 100%, achieve such readings introduction to the comparison channel of the spectrophotometer neutral attenuator, and then write down the curve of the relative transmittance, fulfilling all the requirements set out in clause 4.4.3.

5. Processing of the results

5.1. The processing of the measurement results by the absolute method

5.1.1. Conduct base line (tangent to the curve of transmittance) (Fig.1) was on the curve of the transmittance (). If you cannot spend the base line to the curve of the transmittance measured at =900−1400 cm, the transmittance curve spread on a larger spectral range, allowing to carry out the base line.

5.1.2. According to the measured transmission curve determine the value of , the fraction corresponding to low dependence (), and baseline — comparative value , in fractions of a unit, with the same wave number (see the devil.1).

5.1.3. The concentration of optically active oxygen to two significant digits is calculated by the formula

, (1)

where ,

3,3·10cm — calibration coefficient, determined according activation analysis;

 — coefficient taking into account multiple reflection of infrared radiation in the sample and depend on and . Values find features.3.

When using the dependencies given on features.3−6, to find intermediate values, use linear interpolation.

5.2. Processing of results of measurements using a differential method

5.2.1. Conduct base line (tangent to the curve of the relative transmittance) (Fig.2) on the registered curve of the relative transmittance (). If you cannot spend the base line to the curve of the relative transmittance measured at =900−1400 cm, a curve of the relative transmittance circulate on a larger spectral range, allowing to carry out the base line.

5.2.2. On the measured curve of the relative transmittance to determine the value corresponding to the minimum of the dependence (), and baseline — comparative value , at the same (damn.2).

5.2.3. The concentration of oxygen is calculated to two significant figures by the formula

, (2)

where the measured thickness of sample, cm;

is a coefficient determined from the resistivity, type of conductivity that take into account multiple reflection of infrared radiation in the samples. The dependence of () for various values of the resistivity for (a-Si) and (Si) are shown in hell.4 and 5, respectively.

For (a-Si) with a resistivity of 0.04 to 0.09 Ω·cm value is taken to equal 1 when the calibration coefficient of 3.3·10

cm.

5.3. This method sets the following indicators of the accuracy of measuring the concentration of optically active oxygen.

Random measurement error should not exceed 10% for the absolute method, and method for differential — 20% (with a resistivity of 0.04−0.05 Ω·cm for (a-Si) and resistivity 1−3 Ω·cm for (a-Si) and 10% with a resistivity greater than 0.05 Ohm·cm for (a-Si) and WES more than 4 Ω·cm for (a-Si) with the confidence coefficient =0,95.

The limit value of the total error determined by arithmetic summation of the instrumental error, the calibration error factor of 3.3·10cmequal to 4%, with =0.95, and a random error shown in hell.6 and 7 for =

0,01.

5.4. The result of measuring the concentration of optically active oxygen is a value calculated according to the formulas (1) or (2) with a total measurement uncertainty specified in clause 5.3.

5.5. If the measured value is proved to be less than 1·10cmfor ingots grown by the method (MCH), and less than 8·10cmfor ingots grown by the method of (BZP), the result of the measurements are estimates: less than 1·10cmand less than 8·10

cm.

5.6. Interlaboratory error, defined as the difference between the average (not less than 10 concurrent measurements) values should not exceed 10% with the confidence probability =0,95.

6. Qualifications of the operator

Qualification of operator in the amount necessary to perform measurement this method shall meet the requirements of measuring electrical parameters of semiconductor materials of the fourth or higher rank «of the collection of tariff and qualifying characteristics of works and professions of workers of the enterprises of nonferrous metallurgy. The production of titanium and rare metals, semiconductor materials and quartz products."

7. Requirements for safety

7.1. The device and maintenance of electrical equipment used in accordance with this methodology shall meet the requirements of «Rules of technical operation of electrical installations of consumers and safety regulations in the operation of electrical consumers».

Under the terms of electrical safety of electrical systems used in the measurement of the concentration of optically active oxygen, are electrical installations up to 1000 V.

7.2. Electrical installation (spectrophotometer) should be subjected to regular inspection and preventive repair carried out by representatives of enterprises, producing this installation.

7.3. The measurements allowed persons over the age of 18, having a first qualifying group safety briefed on safety in the workplace with an entry in the journal safety familiar with this method, work instruction and safety manual.

7.4. Grinding, cutting, chemical treatment of samples is carried out in special premises under the hood with observance of security measures.

8. Terms and definitions

Optically active are those oxygen atoms in silicon, which are in interstitial condition. It is assumed that in silicon, all the oxygen atoms are optically active.

The reference sample is called the sample optically polished silicon, which has the same measured sample thickness, and the oxygen concentration determined by the method of activation analysis less than 5·10cm.

Damn.1. Transmittance curve of a typical plate of monocrystalline ingot (n-Si) having a specific electric resistance more than 50 Ohm·cm, measured by the absolute method

Transmittance curve of a typical plate of monocrystalline ingot (-Si)
with specific electrical resistance more than 50 Ohm·cm, measured by the absolute method

Damn.1

Damn.2. Curves of the relative transmittance of a typical plate of monocrystalline ingot (n-Si) having a specific electric resistance of 0.09 Ω·cm, as measured using a differential method

Curves of the relative transmittance of a typical plate of monocrystalline ingot ()
with a specific electric resistance of 0.09 Ω·cm, as measured using a differential method

 — comparison sample () with a value of resistivity of 0.1 Ω·cm, close, but more than WES
the measured sample; b — reference sample (a-Si) with resistivity of 20 Ω·cm

Damn.2

Damn.3. The dependence of the coefficient C of the sample thickness for different values of N' when measured by the absolute method

The dependence of the ratio of sample thickness for different values of
when measured by the absolute method

Curve number	1	2	3	4	Five	6	7
N, cm	1·10	3·10	5·10	7·10	1·10	1,5·10	2·10

Damn.3

Damn.4. The dependence of the coefficient C of N' different values of resistivity of the samples (n-Si) when measured using a differential method

The dependence of the ratio from different values of the resistivity of the samples (a-Si) during
measurements using a differential method

Room curves	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
Resistivity, Ohm·cm	At least 10	5	1	0,7	0,5	0,4	0,3	0,2	0,15	0,12	0,11	0,095	0,093	0,090	20
see	0,2−0,25														Not less than 0.95 to 1.00,

Damn.4

Damn.5. The dependence of the coefficient C of N' for various values of resistivity of the samples (p-Si) when measured using a differential method

The dependence of the coefficients from the different values of the resistivity of the samples (a-Si)
when carrying out measurements using a differential method

Room curves	1	2	3	4	5	6
Resistivity, Ohm·cm	At least 20	10	5,0	2,8	1,0	At least 50
see	0,20−0,25	0,20−0,25	0,20−0,25	0,20−0,25	0,20−0,25	0,09−1,00

Damn.5

Damn.6. The total error from the measured thickness of the specimen calculated for the absolute error of measurement of transmittance of 0.01 in determining the concentration of optically active oxygen by the absolute method

The dependence of the total error from the measured thickness of the sample , calculated
for in determining the concentration of optically active oxygen by the absolute method

Room curves	1	2	3	4	5	6	7
see	1·10	3·10	5·10	7·10	1·10	1,5·10	2·10

Damn.6

Damn.7. The dependence of the total error in N calculated for the absolute error of measurement of transmittance of 0.01 in determining the differential method

The total error from the calculated for a =0,01
when determining differential method

Curve number	see	Resistivity, Ohm·cm (a-Si)	Resistivity, Ohm·cm (a-Si)
1	0,95−1,00	More than 20	More than 50
2	0,20−0,25	More than 0.05	More than 3
3	0,20−0,25	0,04−0,05	1−3

Damn.7

ANNEX 7. (Changed edition, Rev. N 1).

ANNEX 8 (obligatory). MEASUREMENT of the lifetime of NONEQUILIBRIUM CHARGE CARRIERS (N. N. z.) IN INGOTS OF MONOCRYSTALLINE SILICON BY THE METHOD OF CONDUCTIVITY MODULATION IN A POINT CONTACT

ANNEX 8
Mandatory

The method is designed for measurement of the lifetime of nonequilibrium charge carriers in single crystal silicon with a specific electrical resistance of 5·10-5·10Ohm·cm in the following ranges:

more than 2.8 µs for silicon -type conductivity;

more than 7.7 µs for silicon -type conductivity and includes an indicator method of measurement of the lifetime of nonequilibrium charge carriers having a lifetime of at least 2 µs.

1. The essence of the method

The measured sample includes an electrical circuit. One of the current leads is large ohmic contact area, and the other is carried out by pressing the metal point of the probe to the semiconductor surface. Point contact is the emitter through which to forward direction skip two time-shifted pulse current. The amplitude of these pulses is equal and constant mode (current generator). The voltage drop across the sample due to the passage of these pulses observed on the oscilloscope screen.

The shape of the curves of voltage in a point contact with modulation of conductivity injectisome carriers is shown schematically in hell.1.

Damn.1. The shape of the curves of voltage in a point contact with modulation of conductivity injectisome carriers

Damn.1

At the time of passage of the first (an injecting) pulse to the sample injected non-equilibrium charge carriers, modulating (increasing) the conductivity of the sample.

At the end of an injecting pulse the number of nonequilibrium charge carriers is reduced as a result of recombination, therefore, the contact resistance begins to return to its original value, increasing with time. The voltage on the sample at the beginning of the second (test) pulse is determined by the concentration of nonequilibrium charge carriers remaining in the sample.

Under these conditions, the voltage drop across the sample at the beginning of the measurement impulse will be a function of time delay between pulses . The difference between the amplitudes of the first and second pulses changes in accordance with the delay time according to the law

, (1)

where is the lifetime of nonequilibrium (non-core) of charge carriers.

Fixing the amount and changing the time delay on the inclination of the straight , you could define a lifetime .

2. Requirements for measuring instruments and auxiliary devices

A block diagram of the setup for the measurement of the lifetime of nonequilibrium charge carriers is shown in hell.2.

Damn.2. A block diagram of the setup for the measurement of the lifetime of nonequilibrium charge carriers

1 generator of double pulses; 2 — resistive element that implements the mode of the current generator;
3 — stop pulses; 4 — oscilloscope; 5 — block forming a point contact; 6 — sample

Damn.2

Measurement of the lifetime of nonequilibrium charge carriers in silicon is carried out at the installation types, TAU 102, TAU-202 with an appropriate metric to use them or similar to them.

Allowed the use of special devices that in numerical form the results of the measurement of the lifetime of nonequilibrium charge carriers and guaranteed to measurement error.

2.1. The basic measuring elements, collected at the block diagram (Fig.2) are the dual pulse generator and the oscilloscope registered.

As the generator used appliances of the type G5−7A or G5−30A. As a registered device used oscilloscopes of the type S1−3, S1−5, C1−20 C1−65.

2.2. The probe manufactured for samples:

-type — phosphor bronze BROF 6,5−0,15 GOST 5017;

-type aluminium brand A5 according to GOST 11069*.
_______________
* On the territory of the Russian Federation GOST 11069−2001. — Note the CODE.

2.3. Auxiliary elements to ensure the regime of the current generator, forming a point contact, the limitation of the recorded pulses, etc., United in a schematic diagram (DWG.3). The resistance value of the resistor for mode generator current is to flow through the contact probe according to the constant pulse current, guaranteeing an unchanged level of injection. So the value is 100 Ohms for samples with resistivity less than 1 Ω·cm; 500 Ohms for samples with electrical resistivity of 1 to 100 Ω·cm and 2.7−20 ohms for the samples with electrical resistivity more than 100 Ohm·cm.

Damn.3. Auxiliary elements. Schematic diagram

Damn.3

Using the elements to produce the limitation of the measuring pulse from below, which improves the possibility of registering small values of the difference . As elements use high-frequency diodes type Д311 direct low resistance and low capacitance.

Forming a contact of the probe with the sample surface is carried out by briefly applying to the probe a DC voltage from any source with a voltage of 300−400 V.

If measurements are not necessary simultaneous observation of an injecting and metering pulses. Their time delay relative to each other is set directly by the generator. For convenience of measurement injectisome first impulse may be not to apply to the input of the oscilloscope, which in the scheme have a switch , switching the synchronization circuit of the oscilloscope.

2.4. Auxiliary materials.

Abrasive materials according to GOST 3647*.
_______________
* On the territory of the Russian Federation c 01.07.2006 will act GOST R 52381−2005. — Note the CODE.

Diamond powder according to GOST 9206.

Diamond tools with the use of diamond powders according to GOST 9206. The particle size of main fraction of used abrasive materials and diamond powder must be not more than 100 µm.

Filters obestochennye according to GOST 12026.

The blotting paper.

Paper scale-coordinate PLM brand for GOST 334.

Calico bleached GOST 29298.

Fabric, wrapping, harsh.

Gauze GOST 9412 or GOST 11109.

Ethyl alcohol according to GOST 18300, GOST 5962*.
_______________
* On the territory of the Russian Federation GOST R 51652−2000.

Technical drinking water according to GOST 2874*.
_______________
* On the territory of the Russian Federation GOST R 51232−98.

3. Preparation for measurement

3.1. The measured surface of the end single crystal is polished, abrasive material, diamond powder and diamond tools. In case of insufficient injection allowed the etching of the surface.

3.2. On the side surface of the single crystal to create the ohmic contact area of not less than 1 cmto application of palladium, Nickel, indium-gallium or aluminum-gallium paste.

3.3. All measuring instruments must be enabled and provisioned in accordance with their operational instructions. Seek on the oscilloscope screen two distinct rectangular pulses. Rotating the knob «delay» of the measuring generator, bring together two impulses and knob «amplitude» of the generator sets the same maximum pulse amplitude.

With the appearance on the oscilloscope screen intermittent pulses with the rotation of the pen «repetition rate» to achieve a stable pulse.

3.4. The ingot set in the holder, ensuring reliable connection to the measuring circuit.

3.5. Setting the time delay between the two pulses exceeding the expected lifetime of nonequilibrium charge carriers, seek on the oscilloscope screen of two equal amplitude pulses. The correct choice of the delay interval control, by making sure of the independence of the amplitude of the second pulse from the delay time when the last change within a small range. Further measurements can be watching on the screen of the oscilloscope, only one measuring pulse. The time delay between pulses in the measurement shall not be less than 2−3 .

4. Measurements

4.1. The measurement is carried out at a temperature of (23±2) °C.

4.2. Switch type conductivity are installed in the correct position for the type of conductivity of the measured sample.

4.3. Select the required operating current measurement by inclusion of the appropriate resistor .

4.4. An injecting duration of the pulse is chosen depending on brands samples:

for marks -type the expected lifetime value, a large 30−300 µs;

for marks -type the expected lifetime value, a large 10−300 µs

for brands  — and -types of conductivity with the expected values of the lifetime, the smaller the above — 50 µs.

4.5. Lower the probe to the measured point on the surface of the single crystal (before measurement it is necessary to wipe the surface to be measured ethyl alcohol).

4.6. Achieve the appearance on the screen of the oscilloscope of the pulse, conducting, if necessary, forming the contact.

4.7. Change the delay time as long as the amplitude of the measuring pulse will cease to rise, i.e. before saturation. Under the scheme, the restriction of pulses from the bottom choose, achieving sufficiently precise registration of changes of the amplitude.

4.8. Reducing the time delay, record delay time and the corresponding changes in the amplitude of the measuring pulse.

4.9. In the semilog scale build dependency , where is the delay time.

The slope of the straight line determine the lifetime of nonequilibrium charge carriers by the formula

. (2)

Dependency build for the three or more points.

4.10. Allowed the determination of the lifetime of nonequilibrium charge carriers without plotting two points from the difference of the two values of time delay, the difference of the logarithms is equal to one.

4.10.1. Increase the measuring pulse up to saturation, similar to claim 4.6.6.

4.10.2. Reducing the duration of the delay, record delay time with decreasing measuring pulse for one (or two) of the cage and then when you decrease by 1.7 (or 3, 4) cells.

(Changed edition, Rev. N 1).

4.10.3. The measured lifetime of nonequilibrium charge carriers is equal to the difference was the time delay.

4.11. The low-level measurement of the lifetimes of the silicon with an electrical resistivity of 1 to 3 Ω·cm is held flat by the way by the disappearance of injection of nonequilibrium charge carriers.

5. Subject to the requirements of sec. 2−4 measurement error does not exceed ±20%.

6. Qualifications of the operator

Qualification of operator to the extent necessary to perform the measurements must meet the requirements of measuring electrical parameters of semiconductor materials of the third or higher rank in accordance with the tariff-qualifying collection.

7. Requirements for safety

The device and maintenance of electrical equipment used must meet the requirements of «Rules of technical operation of electrical installations of consumers and safety regulations in the operation of electrical consumers».

According to the electrical conditions of the electrical installation used for the measurement of the lifetime of nonequilibrium charge carriers, are electrical installations with voltage up to 1000 V.

APP 8A (mandatory). MEASUREMENT OF THE CONCENTRATION OF OPTICALLY ACTIVE ATOMS OF CARBON IN THE INGOTS OF MONOCRYSTALLINE SILICON

APPENDIX 8a
Mandatory

The concentration of the optically active carbon in heteroarylboronic ingots of monocrystalline silicon electron or hole types of conductivity differential optical method. Allowed to heat treatment at temperatures not exceeding 750 °C for 3 hours.

The range of concentrations of optically active carbon to be measured by this method from =3·10cm(the ultimate sensitivity of the method, defined as the concentration , a measurement which is performed with a relative error not exceeding 50% with the confidence probability =0,95) up to the limit of solubility of atomic carbon in silicon, equal to 3·10cm.

The concentration of optically active carbon measured on samples with a specific electrical resistance of more than 30 Ohm·cm for silicon -type conductivity and more than 5 Ω·cm for silicon -type conductivity.

1. The essence of the method

The presence of optically active carbon atoms in silicon leads to the appearance of absorption band with a maximum at the value of the wave number of 607 cm(Fig.1). In the same region of the spectrum in silicon, besides carbon bands observed in the absorption band of the crystal lattice with the absorption coefficient in the maximum of 8 cm.

Damn.1. Schematic representation of the experimental spectrum, the relative bandwidth

Schematic representation of the experimental spectrum, the relative bandwidth

Damn.1

In this regard, the optical measurement is carried out using a differential method that automatically exclude the influence of absorption of the crystal lattice. In the sample channel of the dual beam infrared spectrophotometer is placed the sample, and the channel comparison — sample comparison.

The concentration of optically active carbon is proportional to its absorption coefficient at the maximum of the impurity band : where =1,1·10cm — calibration coefficient, determined from the comparison of optical data with the results of the activation analysis.

2. Equipment, measuring devices and materials

Types of spectrophotometer «Specord-75 IR», «Perxin-Elmer-983», or any dual-beam spectrophotometer measurement with an optical slit width of not more than 5 cmand the absolute error of measurement of transmittance of not more than 0,012 at standard measurements.

The spectrophotometer may also be a device to zoom in on the y-axis, and you can define a small (not more than 0.1 cm) absorption coefficients.

The multi-turn indicator according to GOST 9696 or similar indicator with measurement error no more than 0.001, see

Powders abrasive grinding M28, M14, M7 according to GOST 3647* and GOST 9206.
_______________
* On the territory of the Russian Federation c 01.07.2006 will act GOST R 52381−2005. — Note the CODE.

Paste the diamond ASM-1/0 according to GOST 25593.

Rectified ethyl alcohol according to GOST 17299, GOST 18300.

Hydrofluoric acid according to GOST 10484, technical, or H. h

Nitric acid according to GOST 11125, GOST 701, h.d. a.

Acetic acid according to GOST 61, H. h

Potassium bromide according to GOST 4160, h. h. or h.d. a.

Batiste bleached GOST 29298.

The reference sample.

(Changed edition, Rev. N 2).

3. The conditions of measurement

The measurement is carried out at a temperature of (20±5) °C, other conditions in accordance with the requirements of GOST 12997.

4. Preparation and measurements

4.1. Sample preparation

4.1.1. From the study of single-crystal silicon ingot is cut parallel to the sample (the puck).

4.1.2. The sample is polished on both sides and polished with diamond paste ASM-1 to obtain a surface free of scratches and scratches.

Instead of mechanical polishing allowed chemical etching the polished surface in one of the polishing etchants CP-4 and CP-8 until the brown fumes.

4.1.3. Cross section of the specimen must be greater than the cross section of the working beam of the spectrophotometer.

To measure the concentration of carbon in small samples and for measuring the concentration of optically active carbon in the sample section is allowed, the aperturing of the working beams of the spectrophotometer.

The size of the holes in the diaphragms must be such that the introduction of the diaphragm does not impair any of the passport characteristics of the spectrophotometer.

4.1.4. Before measurements, the polished sample surface carefully wiped with ethanol.

4.1.5. The thickness of the test specimen is measured at four points on two arbitrary, mutually perpendicular directions on the perimeter of the select area that will be covered by the working beam of the spectrophotometer.

The thickness of the measured sample and reference sample at specified points should be in the range of 0.20−0.25 cm, and should not differ from each other by more than ±0,001, see

4.2. Preparation of the spectrophotometer for measurements.

Prepare the spectrophotometer for measurements according to instructions.

4.3. Measurement of the curve of the relative transmittance.

4.3.1. Before each series of measurements, but not less than once per shift, record the 100% line in the region of wave numbers =570−770 cm. If the change in 100% line is greater than the tolerance provided in the specification of the device, the spectrophotometer must be calibrated.

4.3.2. In the channel of the sample beam of the spectrophotometer set to the measured sample, and the channel comparison — sample comparison.

4.3.3. Record the spectrum of the relative transmission of the sample in the to ensure the absence of distortion of the shape of the absorption band of carbon deposited by the spectrophotometer. Recommended operation modes type spectrophotometer «Specord-75 IR» in the table.

4.3.4. The correct choice of recording speed spectrum and a slit program of the spectrophotometer test in two ways.

Type spectrophotometer	Slit program	The scale of registration, mm/100 cm	The amplification nie	Recording time, min/sheet	Time constant
«Specord IR -75"	3	200	6	11х0,3 (manual mode constant deceleration)	10

4.3.4.1. Control the half-width of absorption bands of carbon, which should not exceed 8 cmat a temperature of 300 °K. the half-Width of the absorption bands is equal to half the maximum value of the absorption coefficient of carbon .

4.3.4.2. Check the persistence of the coefficient of relative transmittance in the low absorption bands of carbon while further reduction of the write speed.

5. Processing of the results

5.1. Conduct base line (tangent to the curve of the relative transmittance) was on the curve of the relative transmittance (Fig.1).

5.2. Measured relative transmission curve determine the value of the corresponding minimum of dependence , and baseline — comparative value at the same (damn.1).

5.3. The concentration of carbon calculated to two significant figures by the formula

. (1)

5.4. This method sets the following indicators of the accuracy of measuring the concentration of optically active carbon in monocrystalline silicon.

5.4.1. Random measurement error should not exceed 20% with the confidence probability =0,95.

5.4.2. The limit value of the total error is determined by arithmetic summation of the instrumental and random errors (Fig.2).

Damn.2. The dependence of the relative total error of the concentration of optically active carbon atoms. Absolute error of measurement of transmittance of 0.01

The dependence of the relative total error of the concentration
optically active carbon atoms ; =±1%

Damn.2

5.5. If the concentration calculated by the formula specified in clause 5.3, more than 3·10cm, then the result of measuring the concentration of optically active carbon is a value calculated according to the formula (1), taking into account the measurement uncertainty specified in clause 5.4.2. From the large value the method has no restrictions measured value , up to the solubility limit of carbon is equal to 3·10cm.

If the calculated concentration is less than 3·10cm, then the result of measuring the concentration of optically active carbon is rating: less than 3·

10cm.

5.6. Interlaboratory error, defined as the difference between the average of the ten parallel measurements values should not exceed 25%.

6. Qualifications of the operator

Qualification of operator in the amount necessary to perform measurement according to the present method must conform to measuring electrical parameters of semiconductor materials of the fourth or higher rank in accordance with the tariff-qualifying collection.

7. Requirements for safety

7.1. The device and maintenance of electrical equipment used in accordance with this methodology shall meet the requirements of «Rules of technical operation of electrical installations of consumers and safety regulations in the operation of electrical consumers».

According to the electrical conditions of the installation used for measuring the concentration of optically active carbon, are electrical installations up to 1000 V.

8. Terms and definitions

Optically active carbon atoms — the atoms of carbon in silicon, located in the crystal lattice and substitute the silicon atoms. It is assumed that nettervibration silicon and in silicon subjected to heat treatment at the above-mentioned modes, all the carbon atoms are optically active.

The reference sample is considered the sample of silicon, which has the same measured sample thickness, reflectivity coefficients, electrical resistivity 30 Ω·cm (a-Si) and more than 5 Ω·cm (a-Si), and carbon concentration determined by the method of activation analysis, less than 3·10cm.

The transmittance of the sample of silicon, the ratio of the radiation flux , the missed sample to the flux incident on the sample

.

Coefficient of relative transmittance of the measured sample of silicon (0) relative to the reference sample (s) is the ratio of the transmittances of these samples

.

Curve or spectrum of relative transmittance represents the dependence of the coefficient of relative transmittance wave number .

The absorption coefficient is a measure of the radiation flux absorbed by the sample at wave speed , and characterizes the properties of the material and is the reciprocal of the thickness at which the intensity of the electromagnetic wave in the substance is reduced of 2.78 times. The absorption coefficients corresponding to different absorption mechanisms are summarized.

(Added, Rev. N 1).

ANNEX 9 (required). AVAILABILITY CONTROL SWIRLEY DEFECTS IN MESDICATION INGOTS OF MONOCRYSTALLINE SILICON

ANNEX 9
Mandatory

The methodology is designed to identify and control the presence of swirley mesdication defects in the monocrystalline silicon ingots of electronic and hole types of conductivity with an electrical resistivity of 0.3 Ohm·cm with orientation (111), (100), (013). The technique is applicable to ingots of silicon with a density of microdefects from 1·10to 1·10cm.

1. The essence of the method

Methods of identification swirley defects (swirley pattern) based on differences in the speed of etching regions of the single crystal ingot containing micro-defects, compared to the crystallographically perfect region. The locations of microdefects, the etching rate is changed so that the area of microdefects revealed in the form of flat-bottomed holes, the geometry of which is defined by the orientation of the investigated plane and microdefect (damn.2).

Availability control swirley defects (swirley pattern) is carried out by visual inspection controlled surface and count the number of microdefects in the field of view of the microscope.

2. Apparatus, materials, reagents

Metallographic microscope MMR-4.

Fluorescent lamp with a power of at least 15 watts.

Libra WLTK or VSC-2 according to GOST 29329.

Tubs of vinyl plastic.

Volumetric flasks according to GOST 1770.

Tools with the use of diamond powders according to GOST 9206 fraction of not more than 100/80 microns.

Fabrics, cotton, coarse calico and plain group according to GOST 29298.

The blotting paper.

Filter paper according to GOST 12026.

Hydrofluoric acid OS.h. on the other 6−09−3401 the 6−09−4015, technical GOST 2567, h h, h, h. d. a. according to GOST 10484.

Nitric acid is the OS.h. according to GOST 11125, h, h. e. a., H. h according to GOST 4461, concentrated technical GOST 701.

Acid acetic OS.h. according to GOST 18270, h, H. h, h. d. a. according to GOST 61.

Chromic anhydride h. d. a. according to GOST 3776, technical GOST 2548.

Drinking water according to GOST 2874*.
_______________
* On the territory of the Russian Federation GOST R 51232−98.

Use the snap measurement tools and materials of similar purpose and equal performance.

(Changed edition, Rev. N 2).

3. Sample preparation

3.1. Availability control swirley defects carried on the ends of the single crystal ingots or plates immediately adjacent to the ends of the ingot.

3.2. Controlled surface processed by the tool (cutting or grinding), specified in sec. 2. In the controlled surface should be free of chips, projections, cracks.

3.3. The treated surface washed in running water and dried with filter paper or other cleaning material listed in paragraph 3.

3.4. Chemical polishing.

3.4.1. Use the polishing solution of the composition: hydrofluoric acid — nitric acid in the ratio 1:(2−4).

3.4.2. Monocrystalline ingots or plates immersed in a bath with the polishing solution. In the etching process the solution is heated.

The volume of the polishing solution is 5−10 cmper 1 g of the processed material or of 5−10 cmper 1 cmof the surface. In this case, all subject to the control surface should be coated with a polishing solution. While polishing you need constant agitation of the solution.

3.4.3. The duration of chemical polishing is 2−10 min.

3.4.4. After polishing the ingots or plate quickly unloaded from the solution, washed in running water and dried with filter paper or other cleaning material listed in sec. 2.

3.4.5. Allowed to reuse the polishing solution. The polishing solution becomes unusable if the etching for 10 min. polishing does not occur.

3.4.6. Allowed to chemical polishing to use a solution of the composition: hydrofluoric acid — nitric acid — acetic acid in the ratio (3:6:2).

3.5. Identifying swirley defects.

3.5.1. Plane (111).

3.5.1.1. Use a solution of the composition: hydrofluoric acid is aqueous solution of chromic anhydride (250−300 g/l) in the ratio (3:4).

3.5.1.2. The volume of Etchant is 1.0−1.5 cmper 1 g of the processed material or 1.8−2.2 cmper 1 cmof the surface.

The etching tub with solution close the lid.

3.5.1.3. The duration of etching is 20−30 min.

3.5.1.4. The method of loading of samples is carried out as specified in clause 3.4.2. Unloading of the samples is carried out after dilution of an aqueous solution of chromic anhydride with plenty of water until complete discoloration of the solution.

3.5.1.5. Recommended single use solution for all controlled planes (see PP.3.5.1−3.5.3).

3.5.2. Plane (100).

3.5.2.1 Use a solution of the composition: hydrofluoric acid is aqueous solution of chromic anhydride (1200 g/l) in ratio (1:4).

3.5.2.2. The amount of etching is 1.6−2.2 cmper 1 g of the processed material or 5.5−5.7 cmand over 1 cmof the surface.

3.5.2.3. The duration of etching is 30−40 min.

3.5.3. Plane (013).

3.5.3.1. Use a solution of the composition: hydrofluoric acid is aqueous solution of chromic anhydride (300 g/l) — water in the ratio (3:2:3).

3.5.3.2. The volume of Etchant is 0.8−1.3 cmper 1 g of the processed material or 1.6−1.9 cmby 1 cmof the surface.

3.5.3.3. The duration of etching is 25−30 min.

4. Control

4.1. In the control swirley defects inspect the controlled surface to the naked eye, changing its position relative to the light source. Mark the place on the circuit swirley defects with presumably the highest density of microdefects. In this peripheral region with a width of 5 mm is not considered.

4.2. The density of micro-defects is determined on the metallographic microscope. It is recommended to have in sight not more than 200 pits etching. When working with a microscope MMR-4, the recommended increase is shown in the table.

The density of microdefects, cm	Increase
To 5·10	100
From 5·10to 2·10	100−200
From 2·10to 1·10	200−300

Allowed density of etch pits counting on the part of the field of view.

The number of micro-defects counted in five fields of view, located along the loop swirley defects with a maximum density of microdefects, skipping after each measurement two fields of view.

The density of microdefects in the field of view () is calculated by the formula

, (1)

where is the number of microdefects in the field of view.

When the density of micro-defects no more than 2·10cmfor bars with the orientation (100) and (013) and no more than 3·10cmbars for a (111) orientation bars are considered not containing swirley defects.

4.3. When calculating the density of micro-defects on the surface under a microscope we should distinguish between the etching pits are related to the growth of the microdefects, from figures etching, resulting from the oxidation or mechanical irregularities of the surface (Fig.3, 4).

The density of micro-defects count in round swirley defects, free from the above figures etching.

4.4. The oxide film looks like a smear, islets or solid matte background. When the oxide film hinders the observation swirley defects, controlled surface is subject to repeated mechanical and chemical processing.

4.5. Visual inspection can be detected by the relief etching that is associated with the impurity inhomogeneity. This relief under the microscope appears as a system of grooves.

4.6. To prepare the polishing solution using acid of any purity, to the selective solution (identify swirley defects) use only acid of high purity.

4.7. The measurement error calculated by formula (1), does not exceed 30% with the confidence probability =0,95.

5. Qualifications of the operator

Qualification of operator in the amount necessary to perform measurement this method shall meet the requirements of measuring electrophysical parameters of semiconductor materials of the third or higher rank in accordance with the current tariff-qualification Handbook.

6. Safety requirements

6.1. In carrying out the work according to the availability control swirley mesdication defects in the silicon ingots may experience the following risks and hazards: energy hazard, chemical burns and toxicity (poisoning acids).

6.2. Source of electropenalty are electrical system the following equipment: illuminators of the microscope and a fume cupboard.

6.3. Source of chemical burns and toxicity are: nitric acid, acetic acid and chromic anhydride.

6.4. At performance of works it is necessary to strictly comply with safety regulations and industrial hygiene in a chemical laboratory in accordance with the requirements of GOST 1367.0.

7. Terms and definitions

7.1. Swirley defect (sverlova pattern) — spiral distribution of micro-defects with respect to the axis of growth, detectable after selective etching on the end face of the single crystal ingot (Fig.1) with the density of micro-defects more than 2·10cm.

7.2. Microdefect local area of the ingot, different in properties from the surrounding matrix will be limited by the amount of 10-10microns.

Damn.1. Sverlova picture at the end of monocrystalline silicon

Sverlova picture at the end of monocrystalline silicon

Damn.1

Damn.2. Etching pits, forming swirley picture

Etching pits, forming swirley picture

a — on a (111) plane; b — plane (100); in — plane (013)

An increase of 100

Damn.2

Damn.3. Etching pits caused by oxidation of the sample surface

Etching pits caused by oxidation of the sample surface

Increase 225

Damn.3

Damn.4. Etching pits, occurs due to mechanical irregularities of the sample surface

Etching pits, occurs due to mechanical irregularities of the sample surface

Increase 225