US3967988A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffusion guarded metal-oxide-silicon field effect transistors
Assignee: Motorola Solutions Inc
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Filing: 1975-03-14
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Granted: 1976-07-06
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Expires: 1995-03-14
Abstract
Abstract Metal-oxide-silicon field effect transistors (MOSFET) are shown utilizing diffusion guarding of the gate electrode of a MOSFET device and utilizing the drain of one MOSFET device as the source of the next integrally formed MOSFET device. Other types of isolation shown include the surrounding of a functional unit with a source diffusion area, and/or permanently connecting a gate electrode to a potential level for preventing signal flow past such a gate.
Inventors
- 👤 Uryon S. Davidsohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:57
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/80; H10D84/82; H10D84/83; H10D84/85; H10D99/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
97 words
A method for fabricating a field effect transistor having at least one guard region in a semiconductor substrate of one conductivity type, which comprises: forming spaced apart source and drain regions of opposite conductivity type to said substrate in said substrate, forming an insulating layer over the space between said source and drain regions, forming a conductive gate electrode having two ends over said insulating layer, and subsequently forming said at least one guard region so that the ends of said gate electrode are in registration with a corresponding portion of said at least one guard region.
Claim 2
Independent Claim
97 words
A method for fabricating a field effect transistor having at least one guard region in a semiconductor substrate of one conductivity type, which comprises: forming spaced apart source and drain regions of opposite conductivity type to said substrate in said substrate, forming an insulating layer over the space between said source and drain regions, forming a conductive gate electrode having two ends over said insulating layer, and subsequently forming said at least one guard region so that the ends of said gate electrode are in registration with a corresponding portion of said at least one guard region.
Claim 3
Dependent Claim
19 words
The method of claim 1 in which said insulating layer is silicon dioxide and said gate electrode is silicon.
Claim 4
Dependent Claim
29 words
The method of claim 2 in which said source region extends around said drain region and a separate guard region is diffused at each end of said gate electrode.
Claim 5
Dependent Claim
29 words
The method of claim 1 in which said source region extends around said drain region and a separate guard region is diffused at each end of said gate electrode.
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) | 1979-07-06 | 1980-01-05 | 1980-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-06 | 1984-01-05 | 1984-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-06 | 1988-01-05 | 1988-07-06 | $7700.00 | Window Closed / Lapsed |