Patent ID: 7737510

Claim:
A semiconductor device having a MIS transistor, said MIS transistor comprising: a first gate insulating film formed on a semiconductor substrate; a first gate electrode formed on the first gate insulating film; a first sidewall covering the sides of the first gate electrode and the top surface of part of the semiconductor substrate and made of a first insulating film forming an L shape in cross section; first source/drain regions formed in regions of the semiconductor substrate located outside an area covered by the first gate electrode and the first sidewall; a stress-applying insulating film covering the first gate electrode and the first sidewall; and a second sidewall forming a plate-like shape in cross section and made of a second insulating film, the second sidewall being formed between the first gate electrode and the first sidewall, wherein the stress-applying insulating film is in contact with the bend of the L-shaped first sidewall, and a third sidewall forming an L shape in cross section and made of a third insulating film is formed between the first sidewall and the second sidewall and between the semiconductor substrate and the first sidewall.