Reducing the reverse recovery charge of thyristors by nuclear irradiation
US4311534A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1980 |
| Grant date | Jan 19, 1982 |
| Priority date | — |
| Expiry date | Jun 27, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/084
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of reducing the reverse recovery charge of thyristors without substantially increasing forward voltage drop by first determining the depth of the anode PN junction from a major surface adjoining a cathode emitter region. The depth of maximum defect generation in thyristor on irradiation through the major surface with a given radiation source radiating particles with molecular weight greater than one, preferably proton or alpha particles, and adjusting the energy level at the major surface of the thyristor from the radiation source to provide the depth of maximum defect generation adjacent the anode PN junction and preferably in the anode base region within 20 micrometers of the anode PN junction or in the anode emitter region within 15 micrometers of the anode PN junction. Thereafter the thyristor is irradiated through said major surface with the adjusted energy level from the radiation source to a given dosage to reduce the reverse recovery stored charge of the thyristor without substantially increasing the forward voltage drop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.