CHANNEL STOPPING METHOD USED FOR THICK FIELD INSULATING REGION IN TRIPPLE-WELL STRUCTURE

摘要

PROBLEM TO BE SOLVED: To obtain a thick field insulating region which is manufactured easily and whose size can be reduced easily by a method wherein channel stopping impurities are implanted through the thick field insulating region, at different energy levels and in a plurality of implantation quantities. ;SOLUTION: In order to electrically insulate at least one pair of first- conductivity-type source/drain diffusion parts 11, 12, the source/drain diffusion parts 11, 12 are formed inside a first second-conductivity-type well, and the first well is formed inside a second first-conductivity-type well. In this case, a thick field insulating region 23 is formed on the first well between the pair of source/drain diffusion parts 11, 12. Then, second-conductivity-type impurities in a first implantation quantity are implanted selectively into the first well through the thick field insulating region 23 at a first energy level. In addition, second-conductivity-type impurities in a second implantation quantity are implanted selectively into the first well through the thick field insulating region 23 at a second energy level.;COPYRIGHT: (C)1997,JPO