IP Library Granted Patent US 7,291,220
Granted Patent B2
US 7,291,220 · App. 11/206,855 · Granted Nov 6, 2007

Process of producing silicon wafer

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Quick Facts
Patent No.
US 7,291,220
App. No.
11/206,855
Granted
Nov 6, 2007
Kind
B2
Abstract

A silicon wafer made by the Czochralski method, including a ring-shaped OSF region and having nitrogen concentration ranging from 2.9×10 14 to 5.0×10 15 atoms/cm 3 and oxygen concentration of 1.27×10 18 to 3.0×10 18 atoms/cm 3 is heat-treated in a reducing-gas or inert-gas atmosphere, by increasing the temperature at the rate of 0.5° C./min to 2.0° C./min until the wafer is heated to a heat-treatment temperature of 1000 to 1200° C.

Claims (9)

1. A process of producing a silicon wafer from a single-crystal including a ring-shaped OSF region and having a predetermined nitrogen concentration and a predetermined oxygen concentration prepared by the Czochralski method in a reducing-gas or inert-gas atmosphere, comprising:

inserting a silicon wafer including the ring-shaped OSF region and having the nitrogen concentration ranging from 2.9×10 14 to 5.0×10 15 atoms/cm 3 and the oxygen concentration of 1.27×10 18 to 3.0×10 18 atoms/cm 3 , into a heat-treatment furnace in which the temperature was maintained at 600 to 800° C. in the reducing-gas or inert-gas atmosphere; and

heat-treating the wafer, while maintaining the rate of increasing the temperature at 0.5° C./min to 2.0° C./min until the wafer is heated to a heat-treatment temperature of 1000 to 1200° C.

2. A process of producing a silicon wafer from a single-crystal including a ring-shaped OSF region and having a predetermined nitrogen concentration and a predetermined oxygen concentration prepared by the Czochralski method in a reducing-gas or inert-gas atmosphere, comprising:

inserting a silicon wafer including the ring-shaped OSF region and having the nitrogen concentration ranging from 4.4×10 14 to 5.0×10 15 atoms/cm 3 and the oxygen concentration of 1.15×10 18 to 3.0×10 18 atoms/cm 3 , into a heat-treatment furnace in which the temperature was maintained at 600 to 800° C. in the reducing-gas or inert-gas atmosphere; and

heat-treating the wafer, while maintaining the rate of increasing the temperature at 0.5° C./min to 2.0° C./min until the wafer is heated to a heat-treatment temperature of 1000 to 1200° C.

3. A process of producing a silicon wafer from a single-crystal including a ring-shaped OSF region and having a predetermined nitrogen concentration and a predetermined oxygen concentration prepared by the Czochralski method in a reducing-gas or inert-gas atmosphere, comprising:

inserting a silicon wafer including the ring-shaped OSF region and having the nitrogen concentration ranging from 8.0×10 14 to 5.0×10 15 atoms/cm 3 and the oxygen concentration of 1.35×10 18 to 3.0×10 18 atoms/cm 3 , into a heat-treatment furnace in which the temperature was maintained at 600 to 800° C. in the reducing-gas or inert-gas atmosphere; and

heat-treating the wafer, while maintaining the rate of increasing the temperature at 0.5° to 2.5° C./min until the wafer is heated to a heat-treatment temperature of 1000 to 1200° C.

Assignments (4)
CHANGE OF NAME Recorded Mar 13, 2013
From: COVALENT SILICON CORPORATION
To: GLOBALWAFERS JAPAN CO., LTD.
Reel/Frame 029991/0421 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 11, 2013
From: COVALENT MATERIALS CORPORATION
To: COVALENT SILICON CORPORATION
Reel/Frame 029962/0497 →
MERGER Recorded Jul 6, 2007
From: TOSHIBA CERAMICS CO., LTD.
To: COVALENT MATERIALS CORPORATION
Reel/Frame 019521/0648 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 19, 2005
From: HIRANO, YUMIKO
To: TOSHIBA CERAMICS CO., LTD.
Reel/Frame 016886/0542 →