Patent ID: 6872628
Filing Date: 2005-03-29
Classification: H01L,Y10S

Abstract:
1. A method of manufacturing a semiconductor device, comprising the steps of (a) preparing a substrate; (b) providing a gate structure on a main surface of said substrate; (x) implanting a first impurity of a conductivity type into said main surface of said substrate using said gate structure configured to serve as a mask against implantation, thereby forming a first impurity-injected region having a first depth and a first concentration; (c) after said step (x), providing a sidewall on a side surface of said gate structure; (y) implanting a second impurity of said conductivity type into said main surface of said substrate including a region defined under said sidewall using said gate structure and said sidewall each configured to serve as a mask against implantation, thereby forming a second impurity-injected region having a second depth and a second concentration, said second depth being shallower than said first depth and said second concentration being higher than said first concentration; and (z) implanting a third impurity of said conductivity type into said main surface of said substrate using said gate structure and said sidewall each configured to serve as a mask against implantation, thereby forming a third impurity-injected region having a third depth and a third concentration, said third depth being greater than said first depth and said third concentration being higher than said second concentration, wherein in said step (y), said second impurity-injected region does not overlap said gate structure in plan view.