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. 25, 1995
Filed:
Mar. 29, 1993
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A power DMOS semiconductor device providing improved current detection accuracy can be produced using standard pocessess. The device includes main wells, subwells and a line well which is independent of the main wells and subwells. These wells are formed by doping the surface of a semiconductor substrate with well-forming impurities. The line well surrounds the subwells at a predetermined distance away from the subwells to relax an electric field on the surface of the substrate. Gate electrodes are patterned to form a line opening which surrounds the subwells. The line opening serves as a mask when forming the line well by doping the surface of the substrate with the well-forming impurities. Accordingly, the width of a region between the line well and an adjacent subwell will not fluctuate.