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. 18, 2004
Filed:
Jan. 31, 2002
Zempei Kawazu, Tokyo, JP;
Tetsuya Yagi, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A heterojunction structure has an Al Ga As layer (0<x≦1), on which an Al Ga As layer (0≦y≦1 and y<x) is provided and having a band gap energy smaller than that of the Al Ga As layer and a valence band energy edge higher than that of the Al Ga As layer. When the Al Ga As layer is selectively etched, an Au electrode film is formed on a surface of the Al Ga As layer outside an etching region, a resist pattern is formed covering the Au electrode film and leaving exposed the etching region, and the Al Ga As layer is selectively removed by etching while irradiating with light, using an etching solution having a Fermi level higher than that of the Al Ga As layer.