Patent US3560815A successfully refreshed from Google Patents.
US3560815A
Expired / Lapsed
US
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Voltage-variable capacitor with extendible pn junction region
Assignee: General Electric Co
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Filing: 1968-10-10
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Granted: 1971-02-02
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Expires: 1988-10-10
Abstract
Abstract A PN junction region formed in a portion of a semiconductor wafer extends beneath the edge of a conductor overlaid on an insulating layer atop the wafer, in absence of voltage above a threshold amplitude across the conductor and wafer. As this voltage is increased to exceed the threshold amplitude, majority carriers are repelled from the wafer surface beneath the conductor and sufficient minority carriers are accumulated near the surface to invert the surface. This extends the PN junction beneath the entire conductor, with an attendant increase in junction capacitance.
Inventors
- 👤 Raymond A Sigsbee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:12
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10D; H10D99/00; H10P; H10P95/00; H10W74/00; H10W74/40; H10W74/43; H10W72/00; H10W72/851; H10W72/874; H10W72/884
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
22 words
The voltage-variable capacitor of claim 1 including electrical insulator means situated between said conductive means and said one Surface of said wafer.
Claim 2
Dependent Claim
20 words
The voltage-variable capacitor of claim 1 wherein said semiconductor wafer comprises silicon and said electrical insulator means comprises silicon dioxide.
Claim 3
Dependent Claim
90 words
A voltage-variable capacitor comprising: a semiconductor wafer having a portion of one type conductivity and a region of opposite type conductivity defining a PN junction of predetermined area therein; means for controllably establishing an inversion layer in said one type conductivity portion of said wafer with the layer extending to said region of opposite type conductivity and merging therewith; and means coupled to the sides of said wafer, including means on either side of said PN junction for supplying electrical capacitance from said PN junction together with the inversion layer.
Claim 4
Dependent Claim
28 words
The voltage-variable capacitor of claim 4 wherein said means for controllably establishing an inversion layer includes means affixed to said semiconductor wafer for establishing an electric field thereon.
Claim 5
Dependent Claim
49 words
The voltage-variable capacitor of claim 5 wherein said means affixed to said semiconductor wafer comprises insulator means disposed atop the surface of said wafer and conductive means disposed atop the surface of said insulator means, said conductive means overlapping above the surface of said region of opposite type conductivity.
Claim 6
Dependent Claim
27 words
The voltage-variable capacitor of claim 6 wherein said semiconductor material comprises silicon, said insulator means comprises silicon dioxide, and said conductive means comprises a layer of metal.
Claim 7
Dependent Claim
11 words
The voltage-variable capacitor of claim 7 wherein said metal comprises molybdenum.
Claim 8
Dependent Claim
163 words
A voltage-variable capacitor comprising: a semiconductor wafer of one type conductivity, said wafer containing in each of first and second separate portions thereof a region of opposite type conductivity extending from one surface thereof into said wafer; conductive means insulatingly disposed above said one surface of said wafer over a third portion of said wafer, said conductive means having at least one edge thereof overlapping said first portion of said wafer and at least another edge thereof overlapping said second portion of said wafer; means coupling a variable electrical control potential across said conductive means and said wafer for establishing a surface inversion layer in the wafer that connects the first and second regions of opposite conductivity beneath the conductive means when the amplitude of said potential rises above a predetermined value; and circuit means connected to said region of opposite type conductivity and the remainder of said wafer for providing an output capacitance which varies as said electrical control potential is varied.
Claim 9
Dependent Claim
22 words
The voltage-variable capacitor of claim 9 including electrical insulator means situated between said conductive means and said one surface of said wafer.
Claim 10
Dependent Claim
20 words
The voltage-variable capacitor of claim 10 wherein said semiconductor wafer comprises silicon and said electrical insulator means comprises silicon dioxide.
Claim 11
Dependent Claim
111 words
A voltage-variable capacitor comprising: a semiconductor wafer of one type conductivity containing first and second separate PN junctions of predetermined area therein, said first and second PN junctions being defined respectively by first and second separate regions of opposite type conductivity formed in said semiconductor of said one type conductivity; means for controllably establishing an inversion layer in said one type conductivity portion of said wafer with the layer extending to said first and second separate regions of opposite type conductivity and merging therewtih; and means coupled to said opposite conductivity region of said first PN junction and said wafer to permit electrical sensing of capacitance across said first PN junction.
Claim 12
Dependent Claim
28 words
The voltage-variable capacitor of claim 12 wherein said means for controllably establishing an inversion layer includes means affixed to said semiconductor wafer for establisHing an electric field thereon.
Claim 13
Dependent Claim
55 words
The voltage-variable capacitor of claim 13 wherein said means affixed to said semiconductor wafer comprises insulator means disposed atop the surface of said wafer and conductive means disposed atop the surface of said insulator means, said conductive means overlapping above the surface of each of said first and second separate regions of opposite type conductivity.
Claim 14
Dependent Claim
27 words
The voltage-variable capacitor of claim 14 wherein said semiconductor material comprises silicon, said insulator means comprises silicon dioxide, and said conductive means comprises a layer of metal.
Claim 15
Dependent Claim
11 words
The voltage-variable capacitor of claim 15 wherein said metal comprises molybdenum.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-01 | 1974-08-03 | 1975-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-01 | 1978-08-03 | 1979-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-01 | 1982-08-03 | 1983-02-02 | $7700.00 | Window Closed / Lapsed |