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:
Jul. 30, 1996
Filed:
Dec. 19, 1994
Hidenori Nishihara, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A trench is formed on a main surface of a p+ type monocrystalline silicon substrate. A silicon oxide film is formed extending from the inner surface of trench onto the main surface of p+ type monocrystalline silicon substrate. The thickness of a corner portion positioned on the upper end corner portion of the sidewall of trench in silicon oxide film is larger than the thickness of silicon oxide film positioned on the sidewall of trench. An n type polycrystalline silicon layer extending from the inside of trench onto the main surface of p+ type monocrystalline silicon substrate is formed on silicon oxide film. Thus, a semiconductor device having a trench structure with an improved breakdown voltage for an insulating layer positioned on an upper end corner portion of the sidewall of a trench is obtained.