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. 17, 2012
Filed:
Feb. 20, 2008
Fwu-iuan Hshieh, Saratoga, CA (US);
Fwu-Iuan Hshieh, Saratoga, CA (US);
Abstract
A trenched semiconductor power device includes a plurality of trenched gates surrounded by source regions near a top surface of a semiconductor substrate encompassed in body regions. The trenched semiconductor power device further includes a first epitaxial layer above heavily doped substrate and beyond the trench bottom and a second epitaxial layer above said first epitaxial layer wherein a resistivity Nof said first epitaxial layer is greater than a resistivity Nof said second epitaxial layer represented by a functional relationship of N>N. In an exemplary embodiment, each of the trenched gates include an upper gate portion and lower gate portion formed with single polysilicon deposition processes wherein the lower gate portion is surrounded with a lower gate insulation layer having a greater thickness than an upper gate insulation layer surrounding the upper gate portion.