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. 16, 2004
Filed:
Jan. 30, 2002
Shoji Kitamura, Nagano, JP;
Toshiyuki Matsui, Nagano, JP;
Fuji Electric Co., Ltd., Kawasaki, JP;
Abstract
An N-type semiconductor layer with a low impurity concentration is grown by epitaxial growth on top of an N-type semiconductor substrate. An oxide film, with a desired pattern, is formed on the surface of the semiconductor layer. Using the oxide film as a mask, an active region edge and a guard ring region are formed by ion injection. After formation, the portion that forms the active region is exposed, and a paste containing platinum is coated onto the back surface of semiconductor substrate. The platinum is heat diffused into the substrate. Through this process, a region near the surface of the active region of semiconductor layer reverses to a P-type, and a shallow reverse region is formed, thereby producing a fast diode with adequate soft recovery characteristics.