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:
Mar. 17, 1998
Filed:
May. 24, 1996
Yoshitsugu Yamamoto, Tokyo, JP;
Norio Hayafuji, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor device includes an InP substrate; a channel layer in which electrons, as charge carriers, travel; and an Al.sub.x1 Ga.sub.1-x1 As.sub.y1 P.sub.z1 Sb.sub.1-y1-z1 (0.ltoreq.x1.ltoreq.1, 0.ltoreq.y1<1, 0<z1.ltoreq.1) electron supply layer for supplying electrons to the channel layer. The electron supply layer has an electron affinity smaller than that of the channel layer and is doped with a dopant impurity producing n type conductivity. Since n type AlGaAsPSb is thermally stable, its electrical characteristics are not changed by heat treatment at about 350.degree. C., resulting in a thermally stable and highly reliable HEMT in which the characteristics hardly change with the passage of time during fabrication and operation. Further, a heterostructure including an electron supply layer and a channel layer and having a desired energy band structure is easily produced with a wide degree of freedom in designing the device.