CORE WIRE HOLDER AND METHOD FOR PRODUCING SILICON

• US 20170341944A1
• Filed: 10/30/2015
• Published: 11/30/2017
• Est. Priority Date: 11/04/2014
• Status: Active Grant

• Current Assignee: Tokuyama Corporation
• Original Assignee: Tokuyama Corporation
• Inventors: ISHIDA, Haruyuki
• Granted Patent: US 10,640,385 B2
• Time in Patent Office: Days
• 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
• CPC Class Codes: C23C 16/24 Deposition of silicon only
• CPC Class Codes: C23C 16/4418 Methods for making free-standing articles C23C16/01 takes precedence

Abstract

A core wire holder 3 attached on an electrode 2 placed on a bottom panel of a device 20 for producing silicon by Siemens process includes a silicon core wire holding portion 9 being generally circular truncated cone-shaped, and holding and energizing a silicon core wire 4. The silicon core wire holding portion 9 includes a generally circular truncated cone having an upper surface formed with a silicon core wire insertion hole 7 for holding the silicon core wire 4, and the silicon core wire holding portion 9 includes an upper surface and a side surface, which form a ridge having a curved surface and serving as a chamfered portion 8.

Claims

1. A core wire holder attached on a metal electrode placed on a bottom panel of a device for producing silicon by Siemens process, the core wire holder comprising:

a silicon core wire holding portion being generally circular truncated cone-shaped, and configured to hold and energize a silicon core wire, wherein;

the silicon core wire holding portion includes a generally circular truncated cone having an upper surface formed with a silicon core wire insertion hole for holding the silicon core wire, and

the silicon core wire holding portion includes a chamfered portion having a curved surface formed on a ridge formed by an upper surface and a side surface of the silicon core wire holding portion.

2. The core wire holder of claim 1, further comprising:

a cylindrical-shaped or circular truncated cone-shaped base portion.

3. The core wire holder of claim 1, wherein:

a circular truncated cone, in which the silicon core wire holding portion that is generally circular truncated cone-shaped is inscribed;

includes an upper surface in a shape of a circle with a diameter a,

includes a bottom surface in a shape of a circle with a diameter b, and has a height h,

the silicon core wire holding portion includes the chamfered portion having the curved surface and having a radius R of curvature, and

relations a<

b, a≦

h≦

15a, and a/10≧

R≦

2b are satisfied.

4. The core wire holder of claim 1, wherein the core wire holder is made of carbon.

5. The core wire holder of claim 1, wherein a material for the core wire holder has a coefficient of thermal expansion at a ratio of 0.7-1.7, where a coefficient of thermal expansion of a silicon rod is 1.

6. A method for producing polysilicon by Siemens process, comprising:

using the core wire holder of claim 1, and

depositing polysilicon on the silicon core wire.

7. A method for producing polysilicon by Siemens process, comprising:

using the core wire holder of claim 2, and

depositing polysilicon on the silicon core wire.

8. A method for producing polysilicon by Siemens process, comprising:

using the core wire holder of claim 3, and

depositing polysilicon on the silicon core wire.

9. A method for producing polysilicon by Siemens process, comprising:

using the core wire holder of claim 4, and

depositing polysilicon on the silicon core wire.

10. A method for producing polysilicon by Siemens process, comprising:

using the core wire holder of claim 5, and

depositing polysilicon on the silicon core wire.