Patent ID: 7633124

Claim:
A semiconductor device comprising: a gate insulating film formed on a semiconductor substrate having a first conductivity type; a gate electrode formed on said gate insulating film; a nitrogen-introduced layer formed on the side surfaces of said gate electrode; side walls formed on both side surfaces of said gate electrode via said nitrogen-introduced layer; and a pair of impurity layers having an opposite conductivity type from said first conductivity type, which are formed in said semiconductor substrate to fall on both sides of the gate electrode, wherein said nitrogen-introduced layer is formed directly on the surface of said semiconductor substrate under the side walls, wherein a laminated layer including an oxide film and a nitride film is formed on said nitrogen-introduced layer, wherein said laminated layer has a notch on a lower portion of said nitrogen-introduced layer, wherein said oxide film is arranged between said nitrogen-introduced layer and said nitride film, and wherein said side walls are formed on said laminated layer.