US4638347A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gate electrode sidewall isolation spacer for field effect transistors
Assignee: International Business Machines Corp
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Filing: 1985-08-09
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Granted: 1987-01-20
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Expires: 2005-08-09
Abstract
Abstract A sidewall isolation structure for field effect transistor which includes a first electrical insulating layer and a second electrical insulating layer contiguous with the first layer. The second electrical insulating material is etched above or below the surface level of the first insulating layer to provide recesses in the sidewall isolation structure, and method for the preparation thereof.
Inventors
- 👤 Subramanian S. Iyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:58
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0212; H10D64/00; H10D64/01; H10D64/021; H10D64/60; H10D64/66; H10D64/671; Y; Y10; Y10S; Y10S257/00; Y10S257/90
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
105 words
A sidewall isolation structure for the gate electrode of an insulated gate field effect transistor which comprises a first electrical insulating material and a second and different electrical insulating material contiguous with said first electrical insulating material, and wherein said second and different electrical insulating material being etched below the surface level of said first electrical insulating material and being etched to a greater extent than and at a rate faster than said first electrical insulating material to provide a recess in said sidewall isolation structure wherein said recess is such as to prevent the formation of a continuous metal film over the sidewall isolation.
Claim 2
Dependent Claim
105 words
A sidewall isolation structure for the gate electrode of an insulated gate field effect transistor which comprises a first electrical insulating material and a second and different electrical insulating material contiguous with said first electrical insulating material, and wherein said second and different electrical insulating material being etched below the surface level of said first electrical insulating material and being etched to a greater extent than and at a rate faster than said first electrical insulating material to provide a recess in said sidewall isolation structure wherein said recess is such as to prevent the formation of a continuous metal film over the sidewall isolation.
Claim 3
Dependent Claim
14 words
The structure of claim 1 wherein said first electrical insulating material is silicon dioxide.
Claim 4
Dependent Claim
14 words
The structure of claim 2 wherein said second electrical insulating material is silicon nitride.
Claim 5
Dependent Claim
14 words
The structure of claim 1 wherein said second electrical insulating material is silicon nitride.
Claim 6
Dependent Claim
23 words
The sidewall isolation structure of claim 1 which further includes a third electrical insulating material adjacent said second and different electrical insulating material.
Claim 7
Dependent Claim
30 words
The sidewall isolation structure of claim 5 wherein said third electrical insulating material has an etch rate different from the etch rate of said second and different electrical insulating material.
Claim 8
Dependent Claim
30 words
The sidewall isolation structure of claim 5 wherein said third electrical insulating material has an etch rate substantially the same as the etch rate of said first electrical insulating material.
Claim 9
Dependent Claim
14 words
The structure of claim 5 wherein said first electrical insulating material is silicon dioxide.
Claim 10
Dependent Claim
14 words
The structure of claim 8 wherein said second electrical insulating material is silicon nitride.
Claim 11
Dependent Claim
14 words
The structure of claim 5 wherein said second electrical insulating material is silicon nitride.
Claim 12
Dependent Claim
14 words
The structure of claim 8 wherein said third electrical insulating material is silicon dioxide.
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) | 1990-01-19 | 1990-07-21 | 1991-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-19 | 1994-07-21 | 1995-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-19 | 1998-07-21 | 1999-01-20 | $7700.00 | Window Closed / Lapsed |