US4746500A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pnictide trap for vacuum systems
Assignee: Stauffer Chemical Co
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Filing: 1986-07-16
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Granted: 1988-05-24
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Expires: 2006-07-16
Abstract
Abstract A fore line trap is located before the forepump in a vacuum system. The trap utilizes a cracker, which may be a heated filament or a plasma, and cold walls. The cracker cracks pnictide gas species such as P 4 into other species such as P 2 which have a higher sticking co-efficient. The pnictides are deposited on the cold walls. The cold walls preferably comprise a sleeve which may be removed from the trap and replaced by a clean one.
Inventors
- 👤 Robert W. Parry
- 👤 John A. Baumann
- 👤 Rozalie Schachter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:23
CPC Classifications
B; B01; B01D; B01D8/00; B01J; B01J2219/00; B01J2219/08; B01J2219/0894
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
103 words
A method for removing pnictide 4 vapor species from a vacuum system including a vacuum chamber coupled in fluid flow relationship to a forepump by a vacuum line for preventing said pnictide 4 species from entering said forepump, said method including the steps of: providing a housing upstream from said forepump, causing said pnictide 4 vapor species to flow through said housing, cracking said pnictide 4 vapor species into pnictide 2 in said housing, maintaining at least one wall of said housing at a temperature at which said cracked pnictide 2 adheres to and forms a film on said at least one wall.
Claim 2
Independent Claim
103 words
A method for removing pnictide 4 vapor species from a vacuum system including a vacuum chamber coupled in fluid flow relationship to a forepump by a vacuum line for preventing said pnictide 4 species from entering said forepump, said method including the steps of: providing a housing upstream from said forepump, causing said pnictide 4 vapor species to flow through said housing, cracking said pnictide 4 vapor species into pnictide 2 in said housing, maintaining at least one wall of said housing at a temperature at which said cracked pnictide 2 adheres to and forms a film on said at least one wall.
Claim 3
Dependent Claim
17 words
The method of claim 1 further including the step of positioning said housing in said vacuum chamber.
Claim 4
Dependent Claim
24 words
The method of claim 1 further including the step of positioning said housing in said vacuum line between said vacuum chamber and said forepump.
Claim 5
Dependent Claim
24 words
The method of claim 1 further including the step of removing said at least one wall from said housing to remove said film therefrom.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein said pnictide 4 vapor species is P 4 .
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein said pnictide 4 vapor species is cracked by a heated filament.
Claim 8
Independent Claim
61 words
A method of removing gas from a vacuum system including the steps of: cracking said gas to a form having a higher sticking coefficient than the uncracked gases, and causing said cracked gas to flow against a surface having a temperature at which said cracked gas condenses so that said cracked gas adheres to and forms a film on said surface.
Claim 9
Independent Claim
61 words
A method of removing gas from a vacuum system including the steps of: cracking said gas to a form having a higher sticking coefficient than the uncracked gases, and causing said cracked gas to flow against a surface having a temperature at which said cracked gas condenses so that said cracked gas adheres to and forms a film on said surface.
Claim 10
Dependent Claim
13 words
The method of claim 7 wherein said gases are pnictide 4 vapor species.
Claim 11
Dependent Claim
12 words
The method of claim 8 wherein said gases are P 4 .
Claim 12
Dependent Claim
14 words
The method of claim 7 wherein said gases are cracked by a heated filament.
Claim 13
Dependent Claim
14 words
The method of claim 7 wherein said gases are cracked within a vacuum chamber.
Claim 14
Dependent Claim
20 words
The method of claim 11 wherein said cracked gases are condensed on at least one wall of said vacuum chamber.
Claim 15
Dependent Claim
19 words
The method of claim 7 wherein said gases are cracked in a vacuum line coupled to a vacuum chamber.
Claim 16
Dependent Claim
20 words
The method of claim 13 wherein said cracked gases are condensed in said vacuum line coupled to said vacuum chamber.
Claim 17
Independent Claim
129 words
A method of removing gas from a vacuum system including a vacuum chamber coupled in fluid flow relationship to at least one vacuum line, said method including: cracking said gas in said vacuum chamber to a form having a higher sticking coefficient than the uncracked gas, causing said cracked gas to flow against a first surface having a temperature at which said cracked gas condenses so that said cracked gas adheres to and forms a film on said surface, causing any uncracked gas to flow through said vacuum line, cracking said uncracked gas in said vacuum line, and condensing said cracked gas on a second surface in said vacuum line maintained at a temperature at which said cracked gas adheres to and forms a film on said second surface.
Claim 18
Independent Claim
129 words
A method of removing gas from a vacuum system including a vacuum chamber coupled in fluid flow relationship to at least one vacuum line, said method including: cracking said gas in said vacuum chamber to a form having a higher sticking coefficient than the uncracked gas, causing said cracked gas to flow against a first surface having a temperature at which said cracked gas condenses so that said cracked gas adheres to and forms a film on said surface, causing any uncracked gas to flow through said vacuum line, cracking said uncracked gas in said vacuum line, and condensing said cracked gas on a second surface in said vacuum line maintained at a temperature at which said cracked gas adheres to and forms a film on said second surface.
Claim 19
Dependent Claim
16 words
The method of claim 15 wherein said first surface is a wall of said vacuum chamber.
Claim 20
Dependent Claim
13 words
The method of claim 15 wherein said first and second surfaces are removable.
Claim 21
Dependent Claim
14 words
The method of claim 15 wherein said gas is a pnictide 4 vapor species.
Claim 22
Dependent Claim
12 words
The method of claim 18 wherein said gas is P 4 .
Claim 23
Dependent Claim
14 words
The method of claim 15 wherein said gas is cracked by a heated filament.
References Cited (Backward Citations)
US4355010A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |