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:
Jul. 22, 1997
Filed:
Mar. 08, 1995
Minoru Sawada, Hirakata, JP;
Shigeharu Matsushita, Katano, JP;
Satoshi Terada, Hirakata, JP;
Emi Fujii, Nara-ken, JP;
Yasoo Harada, Hirakata, JP;
Sanyo Electric Co., Ltd., Osaka-fu, JP;
Abstract
A field effect semiconductor device comprises a first channel layer composed of an undoped semiconductor in which electrons mainly drift in low-noise operation and a second channel layer composed of a semiconductor of one conductivity type in which electrons mainly drift in high-power operation, a third channel layer being provided in the second channel layer or on the second channel layer on the opposite side of the first channel layer. The third channel layer is constituted by at least one semiconductor layer of the one conductivity type or undoped having a greater electron affinity than that of the second channel layer and having a smaller forbidden bandgap than that of the second channel layer. In another field effect semiconductor device, an undoped impurity diffusion preventing layer having an electron affinity approximately equal to that of the second channel layer is provided between the first channel layer and the second channel layer.