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:
Feb. 11, 1992
Filed:
Feb. 26, 1991
Fumiaki Katano, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A schottky barrier junction gate type field effect transistor includes a buffer layer formed on a semi-insulating GaAs substrate and including at least an undoped GaAs crystalline layer, a first n-type GaAs crystalline layer of a first carrier concentration formed on the buffer layer, and a second n-type GaAs crystalline layer formed on the first n-type GaAs crystalline layer and having a second carrier concentration which is lower than the first carrier concentration. A gate electrode made of a Schottky barrier metal is formed on the second n-type GaAs crystalline layer, and a pair of ohmic electrodes are formed at opposite sides of the gate electrode separately from the gate electrode. A third n-type GaAs crystalline layer is formed under each of the pair of ohmic electrodes and has a third carrier concentration which is higher than the first carrier concentration, and a fourth n-type GaAs crystalline layer is formed between the third n-type GaAs crystalline layer and a region which is composed of the first and second n-type GaAs crystalline layers. The fourth n-type GaAs crystalline layer has a fourth carrier concentration which is not less than the first carrier concentration, and a thickness corresponding to a total thickness of the first and second n-type GaAs crystalline layers.