US3860945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High frequency voltage-variable capacitor
Assignee: RCA Corp
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Filing: 1973-03-29
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Granted: 1975-01-14
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Expires: 1993-03-29
Abstract
Abstract A voltage-variable capacitor having a relatively high figure of merit, Q, and thus useful at relatively high frequencies, includes a thin layer of epitaxial semiconductive material on a highly doped semiconductor substrate. An apertured dielectric layer is disposed on the epitaxial layer and a layer of material capable of making rectifying contact to the semiconductive material is disposed on the dielectric layer, with a portion thereof extending into an aperture in the dielectric layer into rectifying contact with the epitaxial layer. This construction eliminates the need for a diffused, minority-carrier-collecting junction, thereby allowing the epitaxial layer to be thin and the series resistance of the device to be low.
Inventors
- 👤 Robert Herman Dawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:34
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/62; H10D1/64; Y; Y10; Y10S; Y10S148/00; Y10S148/122
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
170 words
A voltage variable capacitor structure comprising: a body of semiconductive material of one type conductivity having a surface, a layer of dielectric material on said surface, said layer of dielectric material having an opening therein exposing a portion of said surface of said body, and a layer of material on said layer of dielectric material, adapted to make rectifying contact with said semiconductive material and having a portion thereof disposed in said opening to define with said body a rectifying junction at the surface of said body, the area of said layer adapted to make rectifying contact with said semiconductive material being large relative to the area of said portion thereof, wherein said body of semiconductive material comprises an epitaxial layer having said one type conductivity disposed on a substrate of semiconductive material having said one type conductivity, said substrate containing conductivity modifiers in an amount of at least 4 X 1020 atoms per cubic centimeter, and said epitaxial layer having a thickness between about one and about two micrometers.
Claim 2
Dependent Claim
170 words
A voltage variable capacitor structure comprising: a body of semiconductive material of one type conductivity having a surface, a layer of dielectric material on said surface, said layer of dielectric material having an opening therein exposing a portion of said surface of said body, and a layer of material on said layer of dielectric material, adapted to make rectifying contact with said semiconductive material and having a portion thereof disposed in said opening to define with said body a rectifying junction at the surface of said body, the area of said layer adapted to make rectifying contact with said semiconductive material being large relative to the area of said portion thereof, wherein said body of semiconductive material comprises an epitaxial layer having said one type conductivity disposed on a substrate of semiconductive material having said one type conductivity, said substrate containing conductivity modifiers in an amount of at least 4 X 1020 atoms per cubic centimeter, and said epitaxial layer having a thickness between about one and about two micrometers.
Claim 3
Dependent Claim
46 words
A voltage variable capacitor structure as defined in claim 1, wherein there are a plurality of openings through said dielectric layer, each opening being narrow and elongated and the direction of elongation of each opening being parallel to the direction of elongation of each other opening.
Claim 4
Dependent Claim
39 words
A voltage variable capacitor structure as defined in claim 1, wherein said layer of material adapted to make rectifying contact with said semiconductive material is a layer of semiconductive material of conductivity type opposite to that of said body.
Claim 5
Dependent Claim
23 words
A voltage variable capacitor structure as defined in claim 3 wherein said layer of opposite conductivity type semiconductive material is doped to degeneracy.
Claim 6
Dependent Claim
26 words
A voltage variable capacitor structure as defined in claim 4 wherein said capacitor further comprises a layer of conductive material on said layer of semiconductive material.
Claim 7
Dependent Claim
24 words
A voltage variable capacitor structure as defined in claim 5 wherein said layer of conductive material is coextensive with said layer of semiconductive material.
Claim 8
Dependent Claim
35 words
A voltage variable capacitor structure as defined in claim 1 wherein the material of each of said epitaxial layer, said suBstrate, and said layer adapted to make rectifying contact to said semiconductive material is silicon.
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) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |