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. 17, 1994
Filed:
Aug. 11, 1992
Yoshikazu Nakagawa, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
A compound semiconductor device includes an undoped semiconductor layer; a doped semiconductor layer formed on the undoped semiconductor layer and having smaller electron affinity than the undoped semiconductor layer; a gate electrode formed on the doped semiconductor layer; a cap layer formed on the doped semiconductor layer; and a source electrode and a drain electrode respectively formed on the cap layer. In the device, an undoped-material layer having greater electron affinity than the doped semiconductor layer and the cap layer, is formed between the doped semiconductor layer and the cap layer. A layer which has the same composition and impurities as those of the doped semiconductor layer and whose impurity concentration is sufficiently higher than an impurity concentration of the doped semiconductor layer may, be provided between the doped semiconductor layer and the cap layer.