US Patent 10128236 Semiconductor device and method for fabricating the same

A semiconductor device is provided. The semiconductor device includes a gate spacer that defines a trench on a substrate and includes an upper part and a lower part, a gate insulating film that extends along sidewalls and a bottom surface of the trench and is not in contact with the upper part of the gate spacer, a lower conductive film that extends on the gate insulating film along the sidewalls and the bottom surface of the trench and is not overlapped with the upper part of the gate spacer, and an upper conductive film on an uppermost part of the gate insulating film on the lower conductive film.