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US3793090A
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Method for stabilizing fet devices having silicon gates and composite nitride-oxide gate dielectrics
Assignee: International Business Machines Corp
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Filing: 1972-11-21
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Granted: 1974-02-19
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Expires: 1992-11-21
Abstract
Abstract Large threshold voltage shifts of silicon gate FET devices having a composite nitride-oxide gate dielectric are greatly reduced by subjecting the nitride to a dry oxygen annealing at temperatures between 970*-1,150*C prior to depositing the silicon gate electrode. Annealing at 1,050*C applied for a duration of one-half to one hour produces excellent results.
Inventors
- 👤 C Barile
- 👤 R Dockerty
- 👤 A Nagarajan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:23
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/65; H10P14/6516; H10P14/6529; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0413; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/0134; H10D64/01344; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/685; H10D64/693; H10D99/00; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/6322; H10P14/6326; H10P14/6328; H10P14/6334; H10P14/6336; H10P14/66; H10P14/662; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215; H10P14/6922; H10P14/6927; H10P14/694; H10P14/6943; H10P14/69433; Y; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/113; Y10S148/114; Y10S148/122
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
11 words
The method as in claim 1 wherein said temperature is 1,050*C.
Claim 2
Dependent Claim
26 words
A method as in claim 1 wherein said FET device is a P channel device and said silicon gate is doped with a P type impurity.
Claim 3
Dependent Claim
32 words
A method as in claim 1 wherein the thickness of said nitride layer lies between 100 and 350 A. and the thickness of said oxide layer lies between 200 and 900 A.
Claim 4
Dependent Claim
20 words
A method as in claim 4 wherein the thickness of each of the nitride and oxide layers is 300 A.
Claim 5
Dependent Claim
18 words
A method as in claim 1 wherein the duration of said annealing step is one hour or less.
Claim 6
Independent Claim
69 words
A method for stabilizing the threshold voltages of silicon gate FET devices of different dimensions and voltage characteristics formed in a monolithic structure, each device having a composite gate dielectric of silicon nitride and silicon oxide comprising: annealing the monolithic structure after the deposition of said nitride and prior to the deposition of said silicon gates in a dry oxygen atmosphere at a temperature between 970* and 1, 150*C.
Claim 7
Independent Claim
56 words
A method for stabilizing the threshold voltage of a silicon gate FET device having a composite gate dielectric of silicon nitride and silicon oxide comprising: annealing the device after the deposition of said nitride and prior to the deposition of said silicon gate in an atmosphere of oxygen at a temperature of between 970* and 1,150*C.
Claim 8
Dependent Claim
32 words
A method as in claim 8 wherein the thickness of said nitride layer lies between 100 and 350 A. and the thickness of said oxide layer lies between 200 and 900 A.
Claim 9
Dependent Claim
20 words
A method as in claim 9 wherein the thickness of each of the nitride and oxide layers is 300 A.
Claim 10
Independent Claim
67 words
A method for stabilizing the threshold voltages of silicon gate FET devices of different dimensions and voltage characteristics formed in a monolithic structure, each device having a composite gate dielectric of silicon nitride and silicon oxide comprising: annealing the monolithic structure after the deposition of said nitride and prior to the deposition of said silicon gates in an oxygen atmosphere at a temperature between 970* and 1150*C.
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) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |