US3821566A
Expired / Lapsed
US
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Method and apparatus for electronically recovering metal nitride oxide semiconductor devices exposed to radiation
Assignee: Westinghouse Electric Corp
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Filing: 1972-03-10
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Granted: 1974-06-28
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Expires: 1992-03-10
Abstract
Abstract A method and apparatus for recovering the original characteristics of complementary metal-nitride-oxide semiconductor devices after irradiation by periodic application of driving and gate voltages above the normal driving and gate voltages to the two complementary devices connected in series.
Inventors
- 👤 J Cricchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:38
CPC Classifications
H; H10; H10P; H10P95/00; H10D; H10D84/00; H10D84/80; H10D84/82; H10D84/83; H10D84/85; H10D99/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
88 words
A method for compensating for threshold voltage shifts caused by irradiation in complementary metal-nitride-oxide semiconductor devices having gate electrodes and having channels connected in series across a source of driving voltage, which comprises periodically varying the magnitude of both the driving voltage source as well as a voltage applied to both of said gate electrodes to thereby transport charge through the oxide layers of the devices to compensate for the generation of trapped charges at the oxide-nitride interfaces of said devices tending to shift the threshold voltages thereof.
Claim 2
Independent Claim
88 words
A method for compensating for threshold voltage shifts caused by irradiation in complementary metal-nitride-oxide semiconductor devices having gate electrodes and having channels connected in series across a source of driving voltage, which comprises periodically varying the magnitude of both the driving voltage source as well as a voltage applied to both of said gate electrodes to thereby transport charge through the oxide layers of the devices to compensate for the generation of trapped charges at the oxide-nitride interfaces of said devices tending to shift the threshold voltages thereof.
Claim 3
Dependent Claim
46 words
The method of claim 1 wherein said source of driving voltage normally is at a level of 10 volts and the bias voltage applied to the gates of said devices is at 10 volts, said driving and bias voltage sources being periodically increased to 30 volts.
Claim 4
Dependent Claim
40 words
The method of claim 1 wherein said driving voltage is initially increased, followed by applying a voltage of like magnitude to the gate electrodes of said complementary devices, and then reducing the voltage applied to said gate electrodes to 0.
Claim 5
Dependent Claim
80 words
In combination, complementary P-channel and N-channel metal-nitride-oxide semiconductor devices connected in series across a source of driving potential with their drain contacts interconnected, means for applying a bias voltage to the gate electrodes of both of said devices such that one device will conduct when the bias voltage is present and the other will conduct when the bias voltage is absent, and means for periodically increasing said bias voltage and said driving potential to compensate for irradiation of said devices.
Claim 6
Dependent Claim
80 words
In combination, complementary P-channel and N-channel metal-nitride-oxide semiconductor devices connected in series across a source of driving potential with their drain contacts interconnected, means for applying a bias voltage to the gate electrodes of both of said devices such that one device will conduct when the bias voltage is present and the other will conduct when the bias voltage is absent, and means for periodically increasing said bias voltage and said driving potential to compensate for irradiation of said devices.
Claim 7
Dependent Claim
25 words
The combination of claim 4 wherein said driving potential and bias voltage are normally equal and are increased in equal amounts to compensate for irradiation.
Claim 8
Dependent Claim
42 words
The combination of claim 4 including means for sensing an increase in current through at least one of said devices, and means responsive to an increase in current sensed by said sensing means for increasing said bias voltage and said driving potential.
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) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |