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US4923828A
Expired / Lapsed
US
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Gaseous cleaning method for silicon devices
Assignee: Eastman Kodak Co
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Filing: 1989-08-07
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Granted: 1990-05-08
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Expires: 2009-08-07
Abstract
Abstract A method for cleaning metallic impurities from a silicon surface of a semiconductor device is described. The first method includes, in sequence, the steps of: (a) exposing the silicon surface for a first time to a plasma afterglow anhydrous cleaning gas mixture containing nitric oxide and hydrogen chloride together with an inert carrier gas to remove metallic impurities, and then either; (b) exposing that surface for a second time to a plasma afterglow gas mixture of a fluorocarbon gas and hydrogen or carbon dioxide to remove the silicon oxynitrochloride film which is formed by step (a), leaving a fluorocarbon polymer film; and (c) exposing the surface for a third time to a plasma afterglow gas of oxygen to remove the fluorocarbon polymer film deposited in step (b); or (d) exposing that surface for a second time to a plasma afterglow gas mixture of inorganic fluorine compound gas, O 2 and carrier gas to remove the silicon oxynitrochlorine film which is formed in step (a).
Inventors
- 👤 Ronald Gluck
- 👤 Paul L. Roselle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:40
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P70/12; Y; Y10; Y10S; Y10S148/00; Y10S148/017
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
131 words
A method for cleaning a silicon semiconductor device in which metallic impurities are removed from a silicon surface of the device, said method comprising, in sequence, the steps of: (a) exposing a silicon surface of a device for a first time to a plasma afterglow anhydrous cleaning gas mixture containing nitric oxide and hydrogen chloride together with an inert carrier gas to remove metallic impurities; (b) exposing said surface for a second time to a plasma afterglow gas mixture of a fluorocarbon gas and hydrogen or carbon dioxide to remove the silicon oxynitrochloride film which is formed by step (a), leaving a fluorocarbon polymer film; and (c) exposing said surface for a third time to a plasma afterglow gas of oxygen to remove the fluorocarbon polymer film deposited in step (b).
Claim 2
Independent Claim
131 words
A method for cleaning a silicon semiconductor device in which metallic impurities are removed from a silicon surface of the device, said method comprising, in sequence, the steps of: (a) exposing a silicon surface of a device for a first time to a plasma afterglow anhydrous cleaning gas mixture containing nitric oxide and hydrogen chloride together with an inert carrier gas to remove metallic impurities; (b) exposing said surface for a second time to a plasma afterglow gas mixture of a fluorocarbon gas and hydrogen or carbon dioxide to remove the silicon oxynitrochloride film which is formed by step (a), leaving a fluorocarbon polymer film; and (c) exposing said surface for a third time to a plasma afterglow gas of oxygen to remove the fluorocarbon polymer film deposited in step (b).
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein sequence of steps (a), (b) and (c) is repeated at least one more time.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein the fluorocarbon gas is either CF 4 or CHF 3 .
Claim 5
Independent Claim
101 words
A method for cleaning a silicon semiconductor device in which metallic impurities are removed from a silicon surface of the device, said method comprising, in sequence, the steps of: (a) exposing a silicon surface of a device for a first time to a plasma afterglow anhydrous cleaning gas mixture containing nitric oxide and hydrogen chloride together with an inert carrier gas to remove metallic impurities; (b) exposing said surface for a second time to a plasma afterglow gas mixture of inorganic fluoride compound gas, O 2 and carrier gas to remove the silicon oxynitrochloride film which is formed by step (a).
Claim 6
Independent Claim
101 words
A method for cleaning a silicon semiconductor device in which metallic impurities are removed from a silicon surface of the device, said method comprising, in sequence, the steps of: (a) exposing a silicon surface of a device for a first time to a plasma afterglow anhydrous cleaning gas mixture containing nitric oxide and hydrogen chloride together with an inert carrier gas to remove metallic impurities; (b) exposing said surface for a second time to a plasma afterglow gas mixture of inorganic fluoride compound gas, O 2 and carrier gas to remove the silicon oxynitrochloride film which is formed by step (a).
Claim 7
Dependent Claim
19 words
The method of claim 4 wherein sequence of steps (a) and (b) is repeated at least one more time.
Claim 8
Dependent Claim
23 words
The method of claim 4 where the inorganic fluorine compound gas is NF 3 or SF 6 and the carrier gas is argon.
References Cited (Backward Citations)
US4159917A
Cited
US4849375A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-05-07 | 1993-11-06 | 1994-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-07 | 1997-11-06 | 1998-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-07 | 2001-11-06 | 2002-05-08 | $7700.00 | Window Closed / Lapsed |