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:
Apr. 23, 2013
Filed:
Sep. 06, 2011
Kou-way Tu, New Taipei, TW;
Hsiu-wen Hsu, Hsinchu County, TW;
Yi-yun Tsai, Penghu County, TW;
Yuan-shun Chang, Taipei, TW;
Kou-Way Tu, New Taipei, TW;
Hsiu-Wen Hsu, Hsinchu County, TW;
Yi-Yun Tsai, Penghu County, TW;
Yuan-Shun Chang, Taipei, TW;
Niko Semiconductor Co., Ltd., New Taipei, TW;
Abstract
A fabrication method of a trenched power MOSFET is provided. A pattern layer having a first opening is formed on a substrate. A portion of the substrate is removed, using the pattern layer as a mask, to form a trench in the substrate. A width of the trench is expanded. A gate oxide layer is formed on a surface of the trench. A portion of the gate oxide layer on a bottom of the trench is removed, using the pattern layer as a mask, to form a second opening in the gate oxide layer. The width of the expanded trench is greater than that of the second opening. A thick oxide layer is formed in the second opening. Heavily doped regions are formed beside the thick oxide layer. A gate is formed in the trench. A body layer surrounding the trench is formed. Sources are formed beside the trench.