Patent ID: 8384166

Claim:
A method for manufacturing a semiconductor device comprising: successively forming, a gate insulating film, a first dummy gate section and a second dummy gate section stacked in this order; removing a portion of the first dummy gate section that is located directly beneath outer sides of the second dummy gate section to form a notch section; forming a side wall made of an insulating material at a side part of each of the gate insulating film, the first dummy gate section and the second dummy gate section and filling the notch section with the insulating material; removing the first dummy gate section and the second dummy gate section to leave the gate insulating film and the insulating material filled into the notch section located on outer sides of the gate insulating film; forming a gate electrode made of a conductive material by embedding the removed portion with the conductive material; and wherein at least portions of the sidewall directly contacts the gate electrode.