Method for selecting polycrystalline silicon rod, and method for producing single crystalline silicon

Patent metadata

Field	Value
Publication number	US-9605356-B2
Application number	US-201214111597-A
Country	US
Kind code	B2
Filing date	Apr 4, 2012
Priority date	Jun 2, 2011
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

Plate-like samples each having as a principal plane thereof a cross section perpendicular to the long axis direction of a polycrystalline silicon rod grown by the deposition using a chemical vapor deposition method are sampled; an X-ray diffraction measurement is performed omnidirectionally in the plane of each of the plate-like samples thus sampled; and when none of the plate-like samples has any X-ray diffraction peak with a diffraction intensity deviating from the average value ±2×standard deviation (μ±2σ) found for any one of the Miller indices <111>, <220>, <311> and <400>, the polycrystalline silicon rod is selected as the raw material for use in the production of single-crystalline silicon. The use of such a polycrystalline silicon raw material suppresses the local occurrence of the portions remaining unmelted, and can contribute to the stable production of single-crystalline silicon.

First claim

The invention claimed is:

1. A method for selecting a polycrystalline silicon rod, the method comprising:
obtaining one or more plate-like samples from a polycrystalline silicon rod grown by a chemical vapor deposition process, each of the one or more plate-like samples having a cross section perpendicular to a long axis direction of the polycrystalline silicon rod, wherein the cross section is a principal plane of each of the one or more plate-like samples;
performing an X-ray diffraction measurement omnidirectionally in the principal plane of each of the one or more plate-like samples; and
selecting the polycrystalline silicon rod as suitable for use in the production of single-crystalline silicon when none of the plate-like samples has any X-ray diffraction peak with a diffraction intensity deviating from an average value ±2×standard deviation found for any one of the Miller indices <111>, <220>, <311> and <400>.

2. The method according to claim 1 , wherein the polycrystalline silicon rod is a polycrystalline silicon rod grown by a Siemens method.

3. A method for producing single-crystalline silicon, the method comprising crushing the polycrystalline silicon rod selected by the method according to claim 2 .

4. A method for producing a polycrystalline silicon block, the method comprising crushing the polycrystalline silicon rod selected by the method according to claim 2 .

5. A method for producing single-crystalline silicon, the method comprising crushing the polycrystalline silicon block obtained by the method according to claim 4 .

6. A method for producing single-crystalline silicon, the method comprising crushing the polycrystalline silicon rod selected by the method according to claim 1 .

7. A method for producing a polycrystalline silicon block, the method comprising crushing the polycrystalline silicon rod selected by the method according to claim 1 .

8. A method for producing single-crystalline silicon, the method comprising crushing the polycrystalline silicon block obtained by the method according to claim 7 .

Assignees

• Miyao Shuichi
• Okada Junichi
• Netsu Shigeyoshi
• Shinetsu Chemical Co

Inventors

• Miyao Shuichi
• Okada Junichi
• Netsu Shigeyoshi

Classifications

• C30B35/007

  Apparatus for preparing, pre-treating the source material to be used for crystal growth · CPC title

• C30B15/00

  Single-crystal growth by pulling from a melt, e.g. Czochralski method (under a protective fluid C30B27/00) · CPC title

• C30B29/06

  Silicon · CPC title

• C30B13/00 Primary

  Single-crystal growth by zone-melting; Refining by zone-melting (C30B17/00 takes precedence; by changing the cross-section of the treated solid C30B15/00; under a protective fluid C30B27/00; for the growth of homogeneous polycrystalline material with defined structure C30B28/00) · CPC title

• C01B33/035 Primary

  by decomposition or reduction of gaseous or vaporised silicon compounds in the presence of heated filaments of silicon, carbon or a refractory metal, e.g. tantalum or tungsten, or in the presence of heated silicon rods on which the formed silicon is deposited, a silicon rod being obtained, e.g. Siemens process · CPC title