METHOD OF MANUFACTURING POLYCRYSTALLINE SILICON ROD

• US 20090269493A1
• Filed: 04/03/2009
• Published: 10/29/2009
• Est. Priority Date: 04/23/2008
• Status: Active Grant

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: Kurotani, Shinichi, Netsu, Shigeyoshi, Mizuno, Michihiro, Oguro, Kyoji
• Granted Patent: US 8,328,935 B2
• Time in Patent Office: Days
• US Class Current: 427/255.180
• CPC Class Codes: C01B 33/03 by decomposition of silicon halides or halosilanes or reduction thereof with hydrogen as the only reducing agent
• CPC Class Codes: C01B 33/035 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

Abstract

The present invention utilizes a silicon member (single-crystalline silicon rod), which is cut out from a single-crystalline silicon ingot which is grown by a CZ method or FZ method, as the core wire when manufacturing a silicon rod. Specifically, a planar silicon is cut out from a body portion which is obtained by cutting off a shoulder portion and a tail portion from a single-crystalline silicon ingot and is further cut into thin rectangles to obtain a silicon bar. In the case that the crystal growth axis orientation is <100>, there are four crystal habit lines, and the silicon bar is cut out such that the surface forms an off-angle θ in a predetermined range with the crystal habit line. The provided polycrystalline silicon rod has a low impurity contamination and high single-crystallization efficiency.

Claims

1. A method of manufacturing a polycrystalline silicon rod by silicon deposition on a silicon core wire by a CVD method, wherein

a silicon member which is cut out from a single-crystalline silicon ingot is used as said silicon core wire.

2. The method of manufacturing a polycrystalline silicon rod according to claim 1, wherein

a surface of said silicon core wire is preferably etched off by a removal amount of 50 μ

m to 200 μ

m after being cut out from said single-crystalline silicon ingot.

3. The method of manufacturing a polycrystalline silicon rod according to claim 1, wherein

the silicon deposition by said CVD method is carried out in a gas atmosphere made up of trichlorosilane (TCS) and hydrogen.

4. The method of manufacturing a polycrystalline silicon rod according to claim 1, wherein

said silicon core wire is cut out such that a side face of said core wire forms an angle in the range of 5 to 40 degrees with respect to a crystal habit line of said single-crystalline silicon ingot.

5. The method of manufacturing a polycrystalline silicon rod according to claim 4, wherein

said single-crystalline silicon ingot is grown by a Czochralski method (CZ method) and has an interstitial oxygen concentration of 7 ppma to 20 ppma.

6. The method of manufacturing a polycrystalline silicon rod according to claim 5, wherein

said interstitial oxygen concentration is not less than 17 ppma.

7. The method of manufacturing a polycrystalline silicon rod according to claim 1, wherein

said single-crystalline silicon ingot is grown by a Czochralski method (CZ method) or a floating zone method (FZ method) and said single-crystalline silicon ingot has a crystal growth axis orientation of <

100>

or <

111>

by a Miller index.

8. The method of manufacturing a polycrystalline silicon rod according to claim 7, wherein

a surface of said silicon core wire is preferably etched off by a removal amount of 50 μ

m to 200 μ

m after being cut out from said single-crystalline silicon ingot.

9. The method of manufacturing a polycrystalline silicon rod according to claim 7, wherein

the silicon deposition by said CVD method is carried out in a gas atmosphere made up of trichlorosilane (TCS) and hydrogen.

10. The method of manufacturing a polycrystalline silicon rod according to claim 7, wherein

said single-crystalline silicon ingot is grown by a Czochralski method (CZ method) and has an interstitial oxygen concentration of 7 ppma to 20 ppma.

11. The method of manufacturing a polycrystalline silicon rod according to claim 10, wherein

said interstitial oxygen concentration is not less than 17 ppma.

12. The method of manufacturing a polycrystalline silicon rod according to claim 7, wherein

said silicon core wire is cut out such that a side face of said core wire forms an angle in the range of 5 to 40 degrees with respect to a crystal habit line of said single-crystalline silicon ingot.

13. The method of manufacturing a polycrystalline silicon rod according to claim 12, wherein

said single-crystalline silicon ingot is grown by a Czochralski method (CZ method) and has an interstitial oxygen concentration of 7 ppma to 20 ppma.

14. The method of manufacturing a polycrystalline silicon rod according to claim 13, wherein

said interstitial oxygen concentration is not less than 17 ppma.