Patent ID: 7767535

Claim:
A method of manufacturing a semiconductor device, comprising: forming a dummy gate insulating film on a semiconductor substrate, and forming a dummy gate electrode on the dummy gate insulating film; carrying out ion implantation of an impurity into a surface region of the semiconductor substrate by using the dummy gate insulating film and the dummy gate electrode as a mask, and forming an extension region; forming a gate sidewall insulating film on side faces of the dummy gate insulating film and the dummy gate electrode; doping the impurity into a surface region of the semiconductor substrate by using the dummy gate insulating film, the dummy gate electrode and the gate sidewall insulating film as a mask to form a contact junction region, and forming a source region and a drain region which are constituted of the contact junction region and the extension region; forming an interlayer insulating film on the semiconductor substrate so as to cover the dummy gate insulating film, the dummy gate electrode, and the gate sidewall insulating film; polishing the interlayer insulating film until a surface of the dummy gate electrode is exposed, and planarizing the surface; removing selectively the dummy gate insulating film and the dummy gate electrode to form a gate opening region in the interlayer insulating film; forming a recess on the surface region of the semiconductor substrate by oxidizing the surface of the semiconductor substrate, which is exposed on a bottom portion of the gate opening region, with plasma oxygen at a temperature of not more than 600° C., and by removing selectively the oxidized part; insulating the surface of the recess in a bottom surface of the gate opening region to form a gate insulating film; and burying a gate electrode material in the gate opening region to form a gate electrode, the extension region extending beneath the gate electrode and being in contact with the gate insulating film.