US3611070A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voltage-variable capacitor with controllably extendible pn junction region
Assignee: General Electric Co
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Filing: 1970-06-15
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Granted: 1971-10-05
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Expires: 1990-06-15
Abstract
Abstract A PN junction region formed in a portion of a semiconductor wafer extends beneath the edge of a resistive layer coated on an insulating layer atop the wafer. Voltage applied across the resistive layer may be adjusted in amplitude, with respect to the wafer, to invert at least a fraction of the wafer surface extending from the PN junction beneath a proportionate fraction of the resistive layer. By varying this voltage, the area of the wafer which is inverted is made to vary accordingly, thereby varying capacitance measured across the device. By appropriately shaping the resistive layer, a predetermined capacitance-voltage characteristic may be obtained.
Inventors
- 👤 William E Engeler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:39
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/62; H10D1/64; H10D99/00; H10P; H10P95/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
22 words
The controllable voltage-variable capacitor of claim 1 wherein said insulating means is a layer produced on said one surface of said wafer.
Claim 2
Dependent Claim
21 words
The controllable voltage-variable capacitor of claim 2 wherein said semiconductor wafer comprises silicon and said electrical insulating means comprises silicon dioxide.
Claim 3
Dependent Claim
106 words
A controllable voltage-variable capacitor comprising: a semiconductor wafer of one type conductivity containing a small region of opposite type conductivity in a surface thereof; electrical resistive means overlying said surface with insulating means separating the resistive means from the surface; means including said resistive means for establishing an inversion layer of controllably variable length in said one type conductivity portion of said wafer in said surface with said inversion layer merging with said small region of opposite type conductivity and extending therefrom; and conductor means respectively connected to each of said regions of one type and opposite type conductivity for connecting said capacitor in a circuit.
Claim 4
Dependent Claim
26 words
The controllable voltage-variable capacitor of claim 4 wherein said resistive means is affixed to said semiconductor wafer for establishing an electric potential gradient along said wafer.
Claim 5
Dependent Claim
53 words
The controllable voltage-variable capacitor of claim 5 wherein said means affixed to said semiconductor wafer comprises insulating means disposed atop the surface of said wafer with the resistive means disposed atop the surface of said insulating means and, said resistive means overlapping above the surface of said small region of opposite type conductivity.
Claim 6
Dependent Claim
35 words
The controllable voltage-variable capacitor of claim 6 wherein said semiconductor material comprises silicon, said insulating means comprises silicon dioxide, and said resistive means comprises one of the group consisting of amorphous silicon and chromium nitride.
Claim 7
Dependent Claim
121 words
A controllable voltage-variable capacitor comprising: a semiconductor wafer of one type conductivity containing a small region of opposite conductivity formed in a surface thereof; a layer of said one type conductivity at said surface having a resistivity less than that of said wafer and having a depth less than that of said opposite conductivity region; means overlying said surface including resistive means for producing a potential gradient along said surface and establishing an inversion layer of controllably variable lengths in said layer with said inversion layer merging with said region of opposite conductivity and extending for a controllable distance therefrom; and means connected to each of said regions of one type and opposite type conductivity for sensing capacitance of said capacitor.
Claim 8
Dependent Claim
20 words
The controllable voltage-variable capacitor of claim 8 wherein the means overlying said surface is 34 affixed to said semiconductor wafer.
Claim 9
Dependent Claim
51 words
The controllable voltage-variable capacitor of claim 9 wherein said means affixed to said semiconductor wafer comprises insulating means disposed atop the surface of said wafer and resistive means disposed atop the surface of said insulating means, said resistive means overlapping above the surface of said small region of opposite type conductivity.
Claim 10
Dependent Claim
35 words
The controllable voltage-variable capacitor of claim 10 wherein said semiconductor material comprises silicon, said insulating means comprises silicon dioxide, and said resistive means comprises one of the group consisting of amorphous silicon and chromium nitride.
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) | 1974-10-04 | 1975-04-05 | 1975-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-04 | 1979-04-05 | 1979-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-04 | 1983-04-05 | 1983-10-05 | $7700.00 | Window Closed / Lapsed |