Patent ID: 7713819

Claim:
A semiconductor device manufacturing method comprising: forming a first insulating film on a semiconductor substrate; forming a first conductor film on the first insulating film; forming a second insulating film on the first conductor film; forming a first line-and-space pattern by etching the second insulating film and the first conductor film; forming an etched region etched into a second line-and-space pattern perpendicular to the first line-and-space pattern by etching the second insulating film, the first conductor film, the first insulating film, and the semiconductor substrate; burying a third insulating film in the etched region; etching the third insulating film to a middle of the second insulating film; forming a film on the etched region; implanting an impurity into the film parallel to the first line-and-space pattern and obliquely to the semiconductor substrate to form a first portion where the impurity is not implanted into the film and a second portion where the impurity is implanted into the film; etching the first portion; etching the third insulating film to a middle of a film thickness of the first conductor film by using the second portion and the second insulating film as masks; removing the second portion and the second insulating film; forming a fourth insulating film on the first conductor film and the third insulating film; forming a second conductor film on the fourth insulating film; and partially removing the second conductor film to form a buried interconnection formed of the second conductor film.