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:
Nov. 17, 1998
Filed:
May. 25, 1995
Takao Kuroda, Kokubunji, JP;
Yasuhiro Shiraki, Hino, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Disclosed is a semiconductor device comprising an undoped GaAs layer, an intermediate undoped layer and an undoped Ga.sub.1-x Al.sub.x As layer which are successively provided on a substrate made of a semiinsulating GaAs crystal; the intermediate undoped layer being an undoped In.sub.y Ga.sub.1-y As layer, an undoped GaAs.sub.1-z Sb.sub.z layer, a superlattice layer which includes an undoped In.sub.y Ga.sub.1-y As layer and an undoped GaAs.sub.1-z Sb.sub.z layer, a superlattice layer which includes an undoped In.sub.y Ga.sub.1-y As layer and an undoped GaAs layer, or a superlattice layer which includes an undoped GaAs.sub.1-z Sb layer and an undoped GaAs layer. When applied to a high electron mobility transistor, this semiconductor device affords a high current and a high speed and has the merit of a small dispersion in the threshold voltage thereof.