US4264374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cleaning process for p-type silicon surface
Assignee: International Business Machines Corp
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Filing: 1980-05-28
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Granted: 1981-04-28
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Expires: 2000-05-28
Abstract
Abstract A cleaning process for a silicon surface, especially a p-type silicon surface. The surface is exposed to HF/H 2 O fumes, thereby obtaining a hexafluosilicic acid film on the surface. The exposed surface is then treated with a water-based, oxidizing, non-silicon-etchant cleaning agent. There is no intermediate rinse between the latter two steps.
Inventors
- 👤 Klaus D. Beyer
- 👤 Robert H. Kastl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:53
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P70/18; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P70/12; H10P70/125
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
61 words
A method of cleaning a p-type silicon surface comprising the steps of: (1) exposing said surface to HF/H 2 O vapor thereby obtaining a water soluble film on said surface; and (2) treating the exposed surface and dissolving said water soluble film with a water-based, oxidizing, non-silicon-etchant cleaning agent which removes heavy metal from a silicon surface, without an intermediate rinse.
Claim 2
Independent Claim
61 words
A method of cleaning a p-type silicon surface comprising the steps of: (1) exposing said surface to HF/H 2 O vapor thereby obtaining a water soluble film on said surface; and (2) treating the exposed surface and dissolving said water soluble film with a water-based, oxidizing, non-silicon-etchant cleaning agent which removes heavy metal from a silicon surface, without an intermediate rinse.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein the concentration of HF is approximately within the range of 16% to 49%.
Claim 4
Dependent Claim
47 words
The method of claim 2 wherein: the cleaning agent is selected from the group consisting of a mixture of deionized H 2 O, NH 4 OH and H 2 O 2 , and a mixture of deionized H 2 O, HCl and H 2 O 2 .
Claim 5
Dependent Claim
71 words
The method of claim 3 wherein: said first-mentioned cleaning agent consists of approximately 5 parts deionized H 2 O, 1 part of a 30% solution of NH 4 OH and 1 part of a 30% solution of H 2 O 2 ; and said second-mentioned cleaning agent consists of approximately 5 part deionized H 2 O, 1 part 37% solution HCl and 1 part 30% solution H 2 O 2 .
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein: said exposing step has a duration of approximately one minute.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein: said treating step takes place at a temperature in the range of approximately 35° C. to 60° C.
References Cited (Backward Citations)
US2948642A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |