| 摘要 |
<p>This invention is for improving the radiation hardness or radiation resistance of GaAs MESFETs. According to this invention, an n-type active layer (2) is formed by doping a GaAs crystal (1) evenly depthwise in the GaAs crystal, and a Schottky gate electrode (6) is provided on the active layer (2) so that the carrier concentration in the active layer (2) and the thickness of the active layer (2) are set to required values. According to this invention, not only in the case of a total dose of exposure radiation of R=1x10<9> roentgens but also in the case of a higher total dose, at least one of the threshold voltage Vth of the GaAs MESFET, the saturated drain current Idss thereof, and the transconductance gm are 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 a result of considerably improved radiation hardness.</p> |
