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:
Aug. 18, 1998
Filed:
Aug. 13, 1997
Hirofumi Nakano, Tokyo, JP;
Osamu Ishihara, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
On a semiconductor substrate with an active layer, a first-stage recess groove is formed by photolithography and wet or dry etching. On the semiconductor substrate and the surface of the first-stage recess groove, a surface passivation film a crystalline material such as i-GaAs or an insulating film of, e.g., SiON, is formed. The surface passivation film on an area where an ohmic electrodes is to be formed is removed and the ohmic electrode is formed on the area by vapor deposition. Thereafter, in the first-stage recess groove, a second-stage recess groove is formed by photolithography and wet or dry etching. A gate electrode is formed on the second-stage recess groove by sputtering or the like.