The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 28, 1991
Filed:
Oct. 26, 1990
Masanori Nishiguchi, Kanagawa, JP;
Naoto Okazaki, Kyoto, JP;
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 GaAs crystal evenly in the depth direction of the GaAs crystal, and 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 thereof, and 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.