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. 30, 1993
Filed:
Mar. 17, 1992
Kunio Tsuda, Yokohama, JP;
Kouhei Morizuka, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A compound semiconductor device wherein a contact to an n type Al.sub.x Ga.sub.1-x As layer comprises an In.sub.x Ga.sub.1-x As graded-composition layer, an In.sub.x Ga.sub.1-x As contact layer having a constant composition and a metal electrode layer, the In.sub.x Ga.sub.1-x As graded-composition layer is doped with an n type impurity which concentration is higher than a concentration of an impurity activated as n type, whereby, even when a thickness of the In.sub.x Ga.sub.1-x As graded-composition layer is made sufficiently small, a reduction in the carrier concentration of the thin graded-composition layer causes no increase of its resistance and a low-resistance contact is realized.