IP Library Granted Patent US 7,922,814
Granted Patent B2
US 7,922,814 · App. 11/556,524 · Granted Apr 12, 2011

Production process for high purity polycrystal silicon and production apparatus for the same

Assignee: Chisso Corporation
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Quick Facts
Patent No.
US 7,922,814
App. No.
11/556,524
Granted
Apr 12, 2011
Kind
B2
Abstract

In the production process of the present invention for high purity polycrystal silicon, using a vertical reactor having a silicon chloride gas-feeding nozzle and a reducing agent gas-feeding nozzle which are disposed at an upper part and a waste gas discharge pipe, a silicon chloride gas and a reducing agent gas are fed into the reactor to form polycrystal silicon at a tip part of the silicon chloride gas-feeding nozzle by the reaction of the silicon chloride gas with the reducing agent gas, and the polycrystal silicon is allowed to grow from the tip part of the silicon chloride gas-feeding nozzle toward a lower part thereof.

Claims (15)

1. A production process for high purity polycrystal silicon characterized by:

using a vertical reactor comprising a silicon chloride gas-feeding nozzle, a reducing agent gas-feeding nozzle and a waste gas discharge pipe, in which the silicon chloride gas-feeding nozzle is inserted and installed from an upper part of the reactor into an inside of the reactor,

feeding a silicon chloride gas from the silicon chloride gas-feeding nozzle and a reducing agent gas from the reducing agent gas-feeding nozzle into the reactor,

forming polycrystal silicon at a tip part of the silicon chloride gas-feeding nozzle by the reaction of the silicon chloride gas with the reducing agent gas, and

allowing the polycrystal silicon to grow from the tip part of the silicon chloride gas-feeding nozzle toward a lower part thereof.

2. The production process for high purity polycrystal silicon as described in claim 1 , comprising a step for continuously taking out the polycrystal silicon to the outside of the reactor.

3. The production process for high purity polycrystal silicon as described in claim 2 , wherein the step for taking out the polycrystal silicon to the outside of the reactor is carried out by allowing the polycrystal silicon to fall into a cooling zone provided at a lower part of the vertical reactor by an own weight thereof or by a mechanical method to cool it and then discharging it from the bottom of the vertical reactor.

4. The production process for high purity polycrystal silicon as described in claim 2 , wherein the step for taking out the polycrystal silicon to the outside of the reactor is carried out by allowing the polycrystal silicon to fall into a lower part of the vertical reactor by an own weight thereof or by a mechanical method, melting the polycrystal silicon by heating the lower part of the vertical reactor to a temperature of not lower than a melting point of silicon and then discharging it from the bottom of the vertical reactor in the form of a silicon melt.

5. The production process for high purity polycrystal silicon as described in claim 1 , wherein the polycrystal silicon grows without being brought into contact with an inner wall surface of the vertical reactor.

6. The production process for high purity polycrystal silicon as described in claim 1 , wherein the silicon chloride gas is reacted with the reducing agent gas at 800° C. to 1200° C.

7. The production process for high purity polycrystal silicon as described in claim 1 , wherein a face direction of the polycrystal silicon in a crystal growth direction is a (111) face.

8. The production process for high purity polycrystal silicon as described in claim 1 , wherein the silicon chloride gas is at least one gas selected from the group consisting of chlorosilanes represented by Si m H n Cl 2m+2−n (m is an integer of 1 to 3, and n is an integer of 0 or more which does not exceed 2 m+2).

9. The production process for high purity polycrystal silicon as described in claim 1 , wherein the silicon chloride gas is a silicon tetrachloride gas.

10. The production process for high purity polycrystal silicon as described in claim 1 , wherein the reducing agent gas is a gas of at least one selected from the group consisting of sodium, potassium, magnesium, zinc and hydrogen.

11. The production process for high purity polycrystal silicon as described in claim 1 , wherein the reducing agent gas is a zinc gas.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 27, 2011
From: CHISSO CORPORATION
To: JNC CORPORATION
Reel/Frame 026187/0940 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 3, 2006
From: HONDA, SHUICHI; YASUEDA, MINORU; HAYASHIDA, SATOSHI; YAMAGUCHI, MASATSUGU; TANAKA, TORU
To: CHISSO CORPORATION
Reel/Frame 018482/0830 →
Priority Claims (2)
JP 2005-344004 · Nov 29, 2005 · national
JP 2006-043997 · Feb 21, 2006 · national
Continuity (1)
Related Publication 20070123011A1 · May 31, 2007