Patent ID: 7118978

Claim:
A method for producing a semiconductor device comprising: preparing an SOI substrate having a first insulating film between a support substrate and a semiconductor layer; forming an element region and an element-separation region in said semiconductor layer; forming a gate insulating film on said semiconductor layer in said element region; forming a gate electrode on said gate insulating film; forming a second insulating film overlaying an upper surface and side surfaces of said gate electrode; removing said gate insulating film by using said gate electrode overlaid by said second insulating film as a mask, wherein said upper surface and said side surfaces of said gate electrode are overlaid by said second insulating film after said removal of said gate insulating film; performing a first thickness adjustment by a selective epitaxial growth process to obtain a predetermined thickness of said semiconductor layer after removing said gate insulating film; performing ion implantation introducing a low concentration of impurities on said semiconductor layer; forming a first sidewall portion on side surfaces of said gate electrode by removing said second insulating film on an upper surface of said gate electrode; and forming a second sidewall portion on side surfaces of said first sidewall portion.