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. 21, 1989
Filed:
May. 21, 1987
Hikaru Hida, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
For high speed operation and improvement in transconductance, there is disclosed a heterojunction field-effect device comprising, a first layer of a first compound semiconductor material having a relatively high donor impurity concentration, a second layer of a second compound semiconductor material formed on the first layer and having a relatively low donor impurity concentration and a relatively large electron affinity, a third layer of high-purity compound semiconductor material formed on the second layer and having a relatively small electron affinity, a gate electrode formed on the third layer, a source electrode formed on one side of the gate electrode and electrically connected to the first and second layers, and a drain electrode formed on the other side of the gate electrode and electrically connected to the first and second layers, so that a carrier-accumulation layer takes place in the second layer of the relatively low donor impurity concentration due to the difference in electron affinity between the second and third layers.