Patent US4512812A successfully refreshed from Google Patents.
US4512812A
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Method for reducing phosphorous contamination in a vacuum processing chamber
Assignee: Varian Semiconductor Equipment Associates Inc
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Filing: 1983-09-22
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Granted: 1985-04-23
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Expires: 2003-09-22
Abstract
Abstract A method for reducing contamination in a vacuum processing chamber includes introducing into the vacuum chamber a gas selected to react with the contaminant and form a compound more volatile than the contaminant. The volatile compound is then removed from the vacuum chamber, typically by vacuum pumping. In one embodiment, the vacuum chamber is an ion implantation chamber, the contaminant is phosphorous and the gas is water vapor, which reacts with the phosphorous to form phosphine gas or other high vapor pressure phosphorous-containing substances.
Inventors
- 👤 Reuel B. Liebert
- 👤 Carl J. Russo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:11
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/22; C23C14/48; C23C14/56; C23C14/564; C23C16/00; C23C16/44; C23C16/4401; C23C16/4405; C30; C30B; C30B31/00; C30B31/20; C30B31/22; H; H01; H01J; H01J37/00; H01J37/02; H01J37/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
47 words
A method for removing phosphorous contaminants from a vacuum processing chamber comprising the steps of: introducing water vapor into said vacuum chamber to react with said phosphorous contaminants and form a compound more volatile than said phosphorous contaminants; and removing said volatile compound from said vacuum chamber.
Claim 2
Independent Claim
47 words
A method for removing phosphorous contaminants from a vacuum processing chamber comprising the steps of: introducing water vapor into said vacuum chamber to react with said phosphorous contaminants and form a compound more volatile than said phosphorous contaminants; and removing said volatile compound from said vacuum chamber.
Claim 3
Dependent Claim
20 words
The method as defined in claim 1 wherein said step of removing said volatile compound includes vacuum pumping said chamber.
Claim 4
Dependent Claim
25 words
The method as defined in claim 1 wherein said water vapor is introduced into said vacuum chamber at a pressure between 150 and 200 Torr.
Claim 5
Dependent Claim
25 words
The method as defined in claim 1 wherein said water vapor is introduced into said vacuum chamber at a pressure between 50 and 500 Torr.
Claim 6
Dependent Claim
25 words
The method as defined in claim 1 wherein said vacuum chamber is an ion implantation chamber for ion implantation of impurity dopants into semiconductor wafers.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-22 | 1988-10-22 | 1989-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-22 | 1992-10-22 | 1993-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-22 | 1996-10-22 | 1997-04-23 | $7700.00 | Window Closed / Lapsed |