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US5229334A
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Method of forming a gate insulating film involving a step of cleaning using an ammonia-peroxide solution
Assignee: Seiko Epson Corp
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Filing: 1991-08-13
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Granted: 1993-07-20
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Expires: 2011-08-13
Abstract
Abstract A method of producing a semiconductor device which comprises; a first cleaning step of cleaning the surface of Si of a semiconductor device having an Si base or an Si thin film as a substrate (1) by using an APM solution; a second cleaning step of cleaning the surface of Si by using a dilute HF solution to thereby remove the uppermost surface layer (3) of a naturally oxidized film (2) formed in the first cleaning step; and a step of forming a silicon oxide film by thermally oxidizing the cleaned surface of the naturally oxidized film (2).
Inventors
- 👤 Juri Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:32
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P70/18; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6322; H10P14/65; H10P14/6502; H10P14/6506; H10P14/6508; H10P70/15; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; Y; Y10; Y10S; Y10S438/00; Y10S438/906
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
94 words
A method of fabricating a semiconductor device comprising: a first step of cleaning a surface of a silicon body using an ammonia-peroxide solution and producing, by the cleaning step, a first layer of naturally formed oxide having a first thickness on said surface, a second step of removing, by use of a dilute hydrofluoric acid solution, a preselected thickness of said first layer while leaving a portion of said first layer on and protecting said surface; and a step of then forming a second layer of silicon oxide on said surface by thermal oxidation.
Claim 2
Independent Claim
94 words
A method of fabricating a semiconductor device comprising: a first step of cleaning a surface of a silicon body using an ammonia-peroxide solution and producing, by the cleaning step, a first layer of naturally formed oxide having a first thickness on said surface, a second step of removing, by use of a dilute hydrofluoric acid solution, a preselected thickness of said first layer while leaving a portion of said first layer on and protecting said surface; and a step of then forming a second layer of silicon oxide on said surface by thermal oxidation.
Claim 3
Dependent Claim
24 words
A method according to claim 1 including, after forming said second layer, removing a preselected thickness from an upper portion of said second layer.
Claim 4
Dependent Claim
16 words
A method according to claim 1 wherein said dilute hydrofluoric acid solution includes hydrogen peroxide acid.
Claim 5
Dependent Claim
27 words
A method according to claim 2 wherein a dilute hydrofluoric acid solution is used for removing said preselected thickness from the upper portion of said second layer.
Claim 6
Dependent Claim
29 words
A method according to claim 1 wherein said preselected thickness of said first layer removed during said second step is within the range from 1 Å to 8 Å.
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) | 1996-07-19 | 1997-01-18 | 1997-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-19 | 2001-01-18 | 2001-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-19 | 2005-01-18 | 2005-07-20 | $7700.00 | Window Closed / Lapsed |