US3725151A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making an igfet defice with reduced gate-to- drain overlap capacitance
Assignee: Motorola Solutions Inc
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Filing: 1971-10-29
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Granted: 1973-04-03
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Expires: 1991-10-29
Abstract
Abstract The disclosure teaches a method for producing an IGFET device characterized by an extremely narrow gate area with no overlapping of the source and drain regions. A controlled etch is used to form a pattern in a first layer over the substrate to precisely define the gate width. The substrate is subsequently oxidized so that the material covering the gate area can be preferentially etched away, thereby creating a window precisely defining the gate electrode. The need for precisely registering masks is avoided. A superior IGFET with greater speed of response and other concomitant advantages results.
Inventors
- 👤 D Zoroglu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:40
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/40; H10D; H10D99/00; H10P; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/051; Y10S148/053; Y10S148/106
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
28 words
The invention of claim 1 wherein the substrate is monocrystalline silicon(111) and the first and second layers of said sandwich are composed of silicon nitride and silica respectively.
Claim 2
Dependent Claim
22 words
The invention of claim 1 wherein the width of said gate area defined by said undercut first layer is approximately 0.25 micron.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |