US4816894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor variable capacitance element
Assignee: ELECTRONICS Ltd 31-1 KAMEIDO 6-CHOME KOTO-KU TOKYO JAPAN
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Filing: 1987-01-29
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Granted: 1989-03-28
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Expires: 2007-01-29
Abstract
Abstract A variable capacitive element is comprised of a semiconductor substrate having a major surface and a capacitive region under the major surface of the semiconductor substrate, a floating electrode disposed on and electrically insulated from the semiconductor substrate through an insulating film for storing electric charge to build up an electric potential in the floating electrode according to the stored amount of electric charge to thereby determine an amount of capacitance of the capacitive region, and a control electrode for injecting electric charge into the floating electrode. A terminal electrode is electrically connected to the capacitive region for electrically connecting the capacitive region to an external circuit. The terminal electrode is capacitively coupled to the floating electrode. A given voltage is applied to the terminal electrode to adjust the electric potential of the floating electrode through the capacitive coupling between the terminal electrode and floating electrode. A capacitor is electrically connected between the terminal electrode and the external circuit for blocking an application of a DC voltage from the external circuit to the terminal electrode.
Inventors
- 👤 Yoshio Hattori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:32
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/62; H10D1/64
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
161 words
A semiconductor variable capacitance element comprising: a floating MOS variable capacitor comprised of a semiconductor substrate, a floating electrode, an insulator film, a capacitance electrode and a control electrode, the semiconductor substrate having a major surface and a capacitance region under the major surface, the floating electrode having opposed major surfaces and being disposed on the major surface of the semiconductor substrate for controlling the capacitance of the capacitive region, the insulator film covering the opposed major surfaces of the floating electrode to insulate the floating electrode from the outside, the capacitance electrode being capacitively strongly coupled to the floating electrode, and the control electrode being formed in the semiconductor substrate for injecting electric charge into the floating electrode; bias means for applying a bias voltage to the capacitance electrode; and a DC blocking capacitor connected to the capacitance electrode to cut out DC voltage of an external circuit and to connect the floating MOS variable capacitor to the external circuit.
Claim 2
Dependent Claim
161 words
A semiconductor variable capacitance element comprising: a floating MOS variable capacitor comprised of a semiconductor substrate, a floating electrode, an insulator film, a capacitance electrode and a control electrode, the semiconductor substrate having a major surface and a capacitance region under the major surface, the floating electrode having opposed major surfaces and being disposed on the major surface of the semiconductor substrate for controlling the capacitance of the capacitive region, the insulator film covering the opposed major surfaces of the floating electrode to insulate the floating electrode from the outside, the capacitance electrode being capacitively strongly coupled to the floating electrode, and the control electrode being formed in the semiconductor substrate for injecting electric charge into the floating electrode; bias means for applying a bias voltage to the capacitance electrode; and a DC blocking capacitor connected to the capacitance electrode to cut out DC voltage of an external circuit and to connect the floating MOS variable capacitor to the external circuit.
Claim 3
Dependent Claim
18 words
A semiconductor variable capacitance element as claimed in claim 1; wherein the insulator film comprises an oxide film.
Claim 4
Dependent Claim
24 words
A semiconductor variable capacitance element as claimed in claim 1; including an RF cut-off element connected between the bias means and the capacitance electrode.
Claim 5
Dependent Claim
27 words
A semiconductor variable capacitance element as claimed in claim 1; wherein the capacitance electrode comprises a diffusion region formed under the major surface of the semiconductor substrate.
Claim 6
Dependent Claim
24 words
A semiconductor variable capacitance element as claimed in claim 2; including an RF cut-off element connected between the bias means and the capacitance electrode.
Claim 7
Dependent Claim
19 words
A semiconductor variable capacitance element as claimed in claim 3; wherein the RF cut-off element comprises a resistance element.
Claim 8
Dependent Claim
19 words
A semiconductor variable capacitance element as claimed in claim 5; wherein the RF cut-off element comprises a resistance element.
Claim 9
Dependent Claim
179 words
A variable capacitive element electrically connectable to an external circuit, comprising: a semiconductor substrate having a major surface and a capacitive region under the major surface of the semiconductor substrate; an insulating film disposed on the major surface of the semiconductor substrate; a floating electrode disposed on the insulating film and electrically insulated from the semiconductor substrate through the insulating film for storing electric charge to build up an electric potential in the floating electrode according to the stored amount of electric charge to thereby determine an amount of capacitance of the capacitive region; a control electrode formed in the semiconductor substrate for injecting electric charge into the floating electrode; a terminal electrode capacitively coupled to the floating electrode; bias means for applying a given voltage to the terminal electrode to change the electric potential of the floating electrode through the capacitive coupling between the terminal electrode and floating electrode; and blocking means electrically connected between the terminal electrode and the external circuit for blocking an application of a DC voltage from the external circuit to the terminal electrode.
Claim 10
Dependent Claim
179 words
A variable capacitive element electrically connectable to an external circuit, comprising: a semiconductor substrate having a major surface and a capacitive region under the major surface of the semiconductor substrate; an insulating film disposed on the major surface of the semiconductor substrate; a floating electrode disposed on the insulating film and electrically insulated from the semiconductor substrate through the insulating film for storing electric charge to build up an electric potential in the floating electrode according to the stored amount of electric charge to thereby determine an amount of capacitance of the capacitive region; a control electrode formed in the semiconductor substrate for injecting electric charge into the floating electrode; a terminal electrode capacitively coupled to the floating electrode; bias means for applying a given voltage to the terminal electrode to change the electric potential of the floating electrode through the capacitive coupling between the terminal electrode and floating electrode; and blocking means electrically connected between the terminal electrode and the external circuit for blocking an application of a DC voltage from the external circuit to the terminal electrode.
Claim 11
Dependent Claim
16 words
A variable capacitive element as claimed in claim 8; wherein the blocking means comprises a capacitor.
Claim 12
Dependent Claim
26 words
A variable capacitive element as claimed in claim 8; wherein the capacitive region comprises a depletion region formed in the semiconductor substrate under the floating electrode.
Claim 13
Dependent Claim
48 words
A variable capacitive element as claimed in claim 10; wherein the terminal electrode comprises a diffusion region formed in the semiconductor substrate adjacent to the depletion region under the floating electrode so that the diffusion region is capacitively strongly coupled to the floating electrode through the insulating film.
Claim 14
Dependent Claim
36 words
A variable capacitive element as claimed in claim 8; including an RF cut element connected between the terminal electrode and the bias means for cutting out RF components of the voltage applied to the bias means.
Claim 15
Dependent Claim
17 words
A variable capacitive element as claimed in claim 12; wherein the RF cut element comprises a resistor.
References Cited (Backward Citations)
US3512052A
Cited
US3611070A
Cited
US3890635A
Cited
US3890631A
Cited
US4021788A
Cited
US4097829A
Cited
US4630082A
Cited
US4529994A
Cited
JPS60201724A
Cited
JPH05275211A
Cited
JPH05309486A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-27 | 1992-09-26 | 1993-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-27 | 1996-09-26 | 1997-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-27 | 2000-09-26 | 2001-03-28 | $7700.00 | Window Closed / Lapsed |