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:
Aug. 04, 1998
Filed:
Sep. 20, 1996
Tsutomu Hayakawa, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A manufacturing method for a semiconductor device is disclosed for effecting improvement of voltage resistance between an N-well and N-type diffusion layer without adversely affecting circuit and transistor characteristics. At the time of forming an N-well, a side wall composed of nitride layer is formed on the oxide layer that is used as a mask in phosphorus implantation, and the N-well is formed using as a mask the oxide layer on which this side wall is provided. The side wall is then removed, boron is implanted, and a channel stopper is formed only between the N-well and N-type diffusion layer. A channel stopper between N-type diffusion layers is formed subsequently as a separate step. In this way, the concentration of the channel stopper between the N-well and N-type diffusion can be set to a concentration different from that of the channel stopper between N-type diffusion layers.