US4240844A
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US
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Reducing the switching time of semiconductor devices by neutron irradiation
Assignee: Westinghouse Electric Corp
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Filing: 1978-12-22
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Granted: 1980-12-23
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Expires: 1998-12-22
Abstract
Abstract The switching time of certain semiconductor devices is decreased while maintaining other electrical characteristics of the devices by irradiating them with a neutron radiation source of greater than 1.0 Mev. to a dosage between 1×10 11 and 1×10 15 neutrons per square centimeter. The irradiation is preferably to a dosage between 1×10 1 and 1×10 14 neutrons per square centimeter and preferably has substantial energy greater than 14 Mev. The devices are also annealed during and/or subsequent to the irradiation at a temperature higher than the highest specified temperature and preferably at least 50° C. higher than the highest specified temperature.
Inventors
- 👤 Patrick E. Felice
- 👤 John Bartko
- 👤 Krishan S. Tarneja
- 👤 Chang K. Chu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:04
CPC Classifications
H; H10; H10P; H10P34/00; H10P34/40; Y; Y10; Y10S; Y10S148/00; Y10S148/165
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
92 words
A method of changing the switching time and recovery charge of certain semiconductor devices comprising the steps of: A. positioning a semiconductor device containing at least one PN junction to be exposed to a neutron radiation source of greater than 1.0 Mev.; B. thereafter irradiating the semiconductor device with the neutron radiation source of greater than 1.0 Mev. to a dosage between 1×10 11 and 1×10 15 neutrons per square centimeter; C. annealing the semiconductor device at a temperature at least as high as the highest specified temperature for storage and use.
Claim 2
Independent Claim
92 words
A method of changing the switching time and recovery charge of certain semiconductor devices comprising the steps of: A. positioning a semiconductor device containing at least one PN junction to be exposed to a neutron radiation source of greater than 1.0 Mev.; B. thereafter irradiating the semiconductor device with the neutron radiation source of greater than 1.0 Mev. to a dosage between 1×10 11 and 1×10 15 neutrons per square centimeter; C. annealing the semiconductor device at a temperature at least as high as the highest specified temperature for storage and use.
Claim 3
Dependent Claim
39 words
A method of changing the switching time and recovery charge of certain semiconductor devices as set forth in claim 1 wherein: the irradiation step is taken to a dosage between 1×10 11 and 1×10 14 neutrons per square centimeter.
Claim 4
Dependent Claim
43 words
A method of changing the switching time and recovery charge of certain semiconductor devices as set forth in claim 1 wherein: the annealing step is performed at a temperature at least 50° C. higher than the highest specified temperature for storage and use.
Claim 5
Dependent Claim
32 words
A method of changing the switching time and recovery charge of certain semiconductor devices as set forth in claim 1 wherein: substantial energy of the radiation source is greater than 14 Mev.
Claim 6
Dependent Claim
34 words
A method of changing the switching time and recovery charge of certain semiconductor devices as set forth in claim 1 wherein: the annealing step is performed at least in part during the irradiation step.
Claim 7
Dependent Claim
30 words
A method of changing the switching time and recovery charge of certain semiconductor devices as set forth in claim 1 wherein: the annealing step is performed after the irradiation step.
Claim 8
Independent Claim
89 words
A method of changing the switching time and recovery charge of thyristors comprising the steps of: A. positioning a thyristor containing at least one PN junction to be exposed to a neutron radiation source of greater than 1.0 Mev.; B. thereafter irradiating the thyristor with the neutron radiation source of greater than 1.0 Mev. to a dosage between about 1×10 11 and 1×10 14 neutrons per square centimeter; and C. annealing the thyristor at a temperature at least as high as the highest specified temperature for storage and use.
Claim 9
Independent Claim
89 words
A method of changing the switching time and recovery charge of thyristors comprising the steps of: A. positioning a thyristor containing at least one PN junction to be exposed to a neutron radiation source of greater than 1.0 Mev.; B. thereafter irradiating the thyristor with the neutron radiation source of greater than 1.0 Mev. to a dosage between about 1×10 11 and 1×10 14 neutrons per square centimeter; and C. annealing the thyristor at a temperature at least as high as the highest specified temperature for storage and use.
Claim 10
Dependent Claim
41 words
A method of changing the switching time and recovery charge of thyristors as set forth in claim 7 wherein: the annealing step is performed at a temperature at least 50° C. higher than the highest specified temperature for storage and use.
Claim 11
Dependent Claim
33 words
A method of changing the switching time and recovery charge of thyristors as set forth in claim 8 wherein: the annealing step is performed at a temperature of at least about 200° C.
Claim 12
Dependent Claim
32 words
A method of changing the switching time and recovery charge of thyristors as set forth in claim 8 wherein: the annealing step is performed at least in part during the irradiation step.
Claim 13
Dependent Claim
28 words
A method of changing the switching time and recovery charge of thyristors as set forth in claim 8 wherein: the annealing step is performed after the irradiation step.
Claim 14
Independent Claim
89 words
A method of changing the switching time and recovery charge of diodes comprising the steps of: A. positioning a diode containing at least one PN junction to be exposed to a neutron radiation source of greater than 1.0 Mev.; B. thereafter irradiating the diode with the neutron radiation source of greater than 1.0 Mev. to a dosage between about 1×10 11 and 1×10 15 neutrons per square centimeter; and C. annealing the diode at a temperature at least as high as the highest specified temperature for storage and use.
Claim 15
Independent Claim
89 words
A method of changing the switching time and recovery charge of diodes comprising the steps of: A. positioning a diode containing at least one PN junction to be exposed to a neutron radiation source of greater than 1.0 Mev.; B. thereafter irradiating the diode with the neutron radiation source of greater than 1.0 Mev. to a dosage between about 1×10 11 and 1×10 15 neutrons per square centimeter; and C. annealing the diode at a temperature at least as high as the highest specified temperature for storage and use.
Claim 16
Dependent Claim
41 words
A method of changing the switching time and recovery charge of diodes as set forth in claim 12 wherein: the annealing step is performed at a temperature at least 50° C. higher than the highest specified temperature for storage and use.
Claim 17
Dependent Claim
33 words
A method of changing the switching time and recovery charge of diodes as set forth in claim 13 wherein: the annealing step is performed at a temperature of at least about 200° C.
Claim 18
Dependent Claim
30 words
A method of changing the switching time and recovery charge of diodes as set forth in claim 13 wherein: substantial energy of the radiation source is greater than 14 Mev.
Claim 19
Dependent Claim
32 words
A method of changing the switching time and recovery charge of diodes as set forth in claim 13 wherein: the annealing step is performed at least in part during the irradiation step.
Claim 20
Dependent Claim
28 words
A method of changing the switching time and recovery charge of diodes as set forth in claim 13 wherein: the annealing step is performed after the irradiation step.
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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) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |