Patent ID: 6649462
Filing Date: 2003-11-18
Classification: H01L,Y10S

Abstract:
A method of manufacturing a semiconductor device, comprising:preparing a semiconductor substrate; forming a dummy-gate insulating film and a dummy gate having a circumferential surface, on a region of said semiconductor substrate, in which an insulated gate field-effect transistor will be formed; introducing an impurity into a surface of said semiconductor substrate selectively, thereby forming a drain region and a source region of said insulated gate field-effect transistor and forming a channel region between said drain region and said source region; forming a first insulating film on said circumferential surface of said dummy gate, said first insulating film having a predetermined etching ratio to said dummy gate; forming a second insulating film above said semiconductor substrate, said second insulating film having a predetermine etching ratio to said first insulating film; processing said second insulating film, thereby giving a substantially flat surface thereto and burying said dummy gate and said first insulating film in said second insulating film; removing a part of said first insulating film to leave the remaining part of said first insulating film at a prescribed height, said remaining part contacting said circumferential surface of said dummy gate; removing said dummy gate and said dummy-gate insulating film above said channel region, thereby making a trench surrounded by said second insulating film and said first insulating film; forming a gate insulating film on said channel region; and wherein said forming of said first insulating film includes forming a first silicon nitride film above an entire surface of said semiconductor substrate after forming a first pair of impurity-diffused layers in said drain and source regions, respectively; forming an oxide film at a side-wall of said dummy gate; removing a portion of said first silicon nitride film, which is not covered with said oxide film, removing said oxide film after introducing an impurity into a surface of said semiconductor substrate selectively, by using said dummy gate and said oxide film as a mask, to form a second pair of impurity-diffused layers in said drain and source regions, respectively, and forming a second silicon nitride film above an entire surface of said semiconductor substrate.