Patent US3576477A successfully refreshed from Google Patents.
US3576477A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Insulated gate fet with selectively doped thick and thin insulators
Assignee: US Philips Corp
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Filing: 1969-05-21
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Granted: 1971-04-27
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Expires: 1989-05-21
Abstract
Abstract An insulated gate field effect transistor is described having a thin insulator under the gate and a thick insulator under source and drain connections. The insulator over the source and drain is impurity doped, which impurity is diffused into the semiconductor body to form the source and drain. However, the insulator under the gate is a mask against diffusion of the said impurity.
Inventors
- 👤 Else Kooi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:48
CPC Classifications
H; H10; H10D; H10D99/00; H10D30/00; H10D30/60; H10P; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/053; Y10S148/151
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
41 words
A transistor as set forth in claim 1 wherein the source and drain contact means comprise conductive layers on the second insulating layer over the first insulating layer and extending through the openings into contact with the source and drain regions.
Claim 2
Dependent Claim
18 words
A transistor as set forth in claim 2 wherein the first insulator is thinner than the second insulator.
Claim 3
Dependent Claim
27 words
A transistor as set forth in claim 3 wherein the gate comprises a conductive layer on the second insulating layer extending into contact with the 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) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |