Patent US2450735A successfully refreshed from Google Patents.
US4042946A
Expired / Lapsed
US
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Radiation hardened field effect device
Assignee: United States Department of the Army
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Filing: 1976-12-08
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Granted: 1977-08-16
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Expires: 1996-12-08
Abstract
Abstract A semiconductor device which utilizes metallic electrodes whose work function can be altered so as to render the device insensitive to the harmful effects caused by exposure to a hostile radiation environment or other events which deleteriously influence the threshold voltage. The gate electrodes of the device consist of materials whose work function is changed by either desorbing or absorbing hydrogen. Depending upon whether the hydride has a larger or smaller work function than the unhydrated material, the invention desorbs or absorbs hydrogen in response to a signal from a sensing circuit which is activated by changes in the threshold voltage of the device.
Inventors
- 👤 Martin M. Sokoloski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 06:07
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D64/00; H10D64/60; H10D64/66; H10D64/665; H10D64/667
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
78 words
A solid state device which remains resistant to degradation generally caused by exposure to a hostile radiation environment which comprises: a field-effect device whose gate electrodes comprise materials whose work function can be changed; and means for changing the amount of hydrogen interstitially present in the materials such that the work function of the electrode gate is varied upon a sensed change in the semiconductor's threshold voltage, whereby the degrading effects on the semiconductors threshold voltage are cancelled.
Claim 2
Dependent Claim
78 words
A solid state device which remains resistant to degradation generally caused by exposure to a hostile radiation environment which comprises: a field-effect device whose gate electrodes comprise materials whose work function can be changed; and means for changing the amount of hydrogen interstitially present in the materials such that the work function of the electrode gate is varied upon a sensed change in the semiconductor's threshold voltage, whereby the degrading effects on the semiconductors threshold voltage are cancelled.
Claim 3
Dependent Claim
37 words
The solid state device as set forth in claim 1 wherein the means for changing the amount of hydrogen present in the gate electrode comprises a heater circuit whereby desorption of hydrogen takes place in said materials.
Claim 4
Dependent Claim
17 words
The solid state device as set forth in claim 2 wherein the materials are hydrides of palladium.
Claim 5
Dependent Claim
40 words
The solid state device as set forth in claim 2 wherein the means for changing the amount of hydrogen present also comprises a switching means for turning on the heater circuit upon a sensed change in the semiconductors threshold voltage.
Claim 6
Dependent Claim
72 words
The solid state device as set forth in claim 1 wherein the means for changing the amount of hydrogen comprises: a container containing pressurized hydrogen which encloses the field-effect device having an outlet which permits hydrogen gas to leave the container; and an activating means for venting the hydrogen from the envelop upon a sensed change in the semiconductor's threshold voltage, whereby hydrogen is exothermally driven out of the gate electrode material.
Claim 7
Dependent Claim
48 words
The solid state device as set forth in claim 5 wherein the activating means comprises: a valve for venting the hydrogen from the container; a relay for operating the valve; and a switching means for turning on the relay upon a sensed change in the semiconductors threshold voltage.
Claim 8
Dependent Claim
62 words
The device set forth in claim 1 wherein the means for changing the amount of hydrogen comprises: a container which surrounds the semiconductor device having an inlet which permits hydrogen gas to enter the container; an activating means which upon the sensed change in the semiconductor's threshold voltage permits the entry of hydrogen gas from a hydrogen source into the exhausted chamber.
Claim 9
Dependent Claim
49 words
The device as set forth in claim 7 wherein the activation means comprises: a valve for controlling the amount of hydrogen gas entering the container; a relay for operating the valve; and a switching means for turning on the relay upon a sensed change in the semiconductor's threshold voltage.
Claim 10
Dependent Claim
41 words
The solid state device as set forth in claim 8 wherein the material chosen for the gate electrodes exothermally absorbs hydrogen and the container and valve are designed so as to maintain a constant partial pressure of hydrogen within the container.
Claim 11
Dependent Claim
37 words
The solid state device as set forth in claim 1 wherein the means for changing the amount of hydrogen present in the materials comprises a switching circuit which has an N-channel MOSFET acting as a control device.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |