Semiconductor device MESFET with upper and lower layers
US5027170A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1990 |
| Grant date | Jun 25, 1991 |
| Priority date | — |
| Expiry date | Nov 13, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S257/907
Abstract
This invention is for improving the radiation hardness or radiation resistance of GaAs MESFETs. According to this invention, an n-type active layer is formed by doping in the GaAs crystal. The n-type active layer includes an upper layer and a heavy doped lower layer. A Schottky gate electrode is provided on the active layer so that the carrier concentration in the active layer and the thickness of the active layer are set to required values. According to this invention, not only in the case of a total dose of exposure radiation of R=1.times.10.sup.9 roentgens but also in the case of a higher total dose, at least one of the threshold voltage V.sub.th of the GaAs MESFET, the saturated drain current I.sub.dss there of, or the transconductance g.sub.m will remain in their tolerable ranges. Consequently a semiconductor device comprising the GaAs MESFET and a signal processing circuit cooperatively combined therewith can operate normally as initially designed, with the result of conspicuously improved radiation hardness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.