Patent ID: 7846826

Claim:
A method of manufacturing a semiconductor device, comprising: a first step of forming a gate dielectric film on a semiconductor substrate; a second step of forming at least a poly-silicon film and a refractory metal film on the gate dielectric film; a third step of patterning at least the refractory metal film to form a patterned refractory metal film that includes first and second side surfaces; a fourth step of forming first and second sidewalls respectively on the first and second side surfaces of the patterned refractory metal film, each of the first and second sidewalls comprising first and second insulating layers that are different in material from each other, the first insulating layer intervening between an associated one of the first and second side surfaces of the patterned refractory metal film and the second insulating layer; a fifth step of patterning the poly-silicon film by using the first and second sidewalls as a mask to form a patterned poly-silicon film that includes third and fourth side surfaces; and a sixth step of oxidizing the third and fourth side surfaces of the patterned poly-silicon film.