Patent US5380370A successfully refreshed from Google Patents.
US5380370A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of cleaning reaction tube
Assignee: Tokyo Electron Ltd
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Filing: 1993-04-30
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Granted: 1995-01-10
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Expires: 2013-04-30
Abstract
Abstract Prior to formation of a polysilicon film on a wafer, a pre-coat film having a thickness of 1 μm and consisting of polysilicon is formed on the inner wall surface of a reaction tube or the surface of a member incorporated in the reaction tube. A polysilicon film is formed on the wafer at a temperature of 450° C. to 650° C. A cleaning gas containing ClF 3 having a concentration of 10 to 50 vol. % is supplied into the reaction tube at a flow rate to an area of an object be cleaned of 750 to 3,500 SCCM/m 2 to remove a polysilicon film deposited on the inner wall surface of the reaction tube or the surface of the member incorporated in the reaction tube by etching using the ClF 3 . In this case, the cleaning gas is supplied while a temperature in the reaction tube is kept at a temperature of 450° C. to 650° C. and in a pressure condition set at the kept temperature such that an etching rate of a polysilicon film by the cleaning gas is higher than an etching rate of quartz constituting the reaction tube or the member incorporated in the reaction tube.
Inventors
- 👤 Reiji Niino
- 👤 Yoshiyuki Fujita
- 👤 Hideki Lee
- 👤 Yasuo Imamura
- 👤 Toshiharu Nishimura
- 👤 Yuuichi Mikata
- 👤 Shinji Miyazaki
- 👤 Takahiko Moriya
- 👤 Katsuya Okumura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:45
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/24; C23C16/30; C23C16/40; C23C16/405; C23C16/44; C23C16/4401; C23C16/4405; C23C16/4412
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
153 words
A method of cleaning an inside of a reaction tube, comprising the steps of: supplying a cleaning gas containing ClF 3 in a concentration of 10 to 50 vol. % into said reaction tube at a flow rate to remove a film deposited on an inner wall surface of said reaction tube or a surface of a member incorporated in said reaction tube by etching using the ClF 3 ; maintaining the temperature in said reaction tube at not less than 450° C. while said cleaning gas is supplied; and setting a pressure condition such that the etching rate of the film being removed by the cleaning gas is higher than the etching rate of the material of said reaction tube or a member incorporated in said reaction tube, said film being selected from the group consisting of a polysilicon based film, a silicon nitride based film, and a silicon oxide based film.
Claim 2
Independent Claim
153 words
A method of cleaning an inside of a reaction tube, comprising the steps of: supplying a cleaning gas containing ClF 3 in a concentration of 10 to 50 vol. % into said reaction tube at a flow rate to remove a film deposited on an inner wall surface of said reaction tube or a surface of a member incorporated in said reaction tube by etching using the ClF 3 ; maintaining the temperature in said reaction tube at not less than 450° C. while said cleaning gas is supplied; and setting a pressure condition such that the etching rate of the film being removed by the cleaning gas is higher than the etching rate of the material of said reaction tube or a member incorporated in said reaction tube, said film being selected from the group consisting of a polysilicon based film, a silicon nitride based film, and a silicon oxide based film.
Claim 3
Dependent Claim
33 words
A method according to claim 1, wherein a flow rate of the cleaning gas to an area of an object be processed falls within a range of 750 to 3500 SCCM/m 2 .
Claim 4
Dependent Claim
18 words
A method according to claim 1, wherein a pressure falls within a range of 0.3 to 5 Torr.
Claim 5
Dependent Claim
56 words
A method according to claim 1, wherein when the film is the polysilicon-based film, a temperature in said reaction tube is 450° C. to 650° C., a flow rate of the cleaning gas to the area of the object be processed is 750 to 3,500 SCCM/m 2 , and a pressure is 0.3 to 5 Torr.
Claim 6
Dependent Claim
17 words
A method according to claim 4, wherein the cleaning gas is supplied for 50 to 150 minutes.
Claim 7
Dependent Claim
56 words
A method according to claim 4, wherein when the film is the silicon-oxide-based film, a temperature in said reaction tube is 450° C. to 650° C., a flow rate of the cleaning gas to the area of the object be processed is 750 to 3,500 SCCM/m 2 , and a pressure is 0.3 to 5 Torr.
Claim 8
Dependent Claim
56 words
A method according to claim 1, wherein when the film is the silicon-nitride-based film, a temperature in said reaction tube is 550° C. to 650° C., a flow rate of the cleaning gas to the area of the object be processed is 750 to 3,500 SCCM/m 2 , and a pressure is 0.3 to 5 Torr.
Claim 9
Dependent Claim
17 words
A method according to claim 7, wherein the cleaning gas is supplied for 35 to 110 minutes.
References Cited (Backward Citations)
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US4568410A
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US5022961A
Cited
US5022961B1
Cited
JPH04157161A
Cited
US5116784A
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US5254176A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-09 | 1998-07-11 | 1999-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-09 | 2002-07-11 | 2003-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-09 | 2006-07-11 | 2007-01-10 | $7700.00 | Window Closed / Lapsed |