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. 28, 2006
Filed:
Jun. 21, 2004
Yoshimi Yamashita, Kawasaki, JP;
Akira Endoh, Kawasaki, JP;
Keiji Ikeda, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
In a nitride-system semiconductor, being different from GaAs and Si, Schottky barrier heights Φchange significantly against work functions Φof metals. Then, for example, on an HEMT in which a buffer layer and a barrier layer constituted by nitride-system semiconductors are sequentially formed on a substrate, and a gate electrode is formed on the barrier layer, when a metal having a relatively large work function Φis selected as a metal constituting the gate electrode, and the thickness of the barrier layer is adjusted so that the Schottky barrier height Φbecomes larger as compared to a semiconductor surface potential Φon both sides of the gate electrode, a two-dimensional electron gas cannot exist below the gate electrode even when no recess is formed on a portion immediately beneath the gate electrode on the barrier layer, so that the enhancement operation becomes possible.