Patent ID: 6333540
Filing Date: 2001-12-25
Classification: H01L

Abstract:
A semiconductor device having an insulated-gate transistor of a first conductivity type, said semiconductor device comprising:a semiconductor substrate having a predetermined semiconductor region of a second conductivity type in its surface;a gate insulating film selectively formed on said predetermined semiconductor region, the surface of said predetermined semiconductor region under said gate insulating film being defined as a channel region;a gate electrode formed on said gate insulating film;first and second extension-forming side walls formed on sides of said gate electrode and containing an extension-forming impurity of the first conductivity type;first and second auxiliary side walls adjacent respectively to said first and second extension-forming side walls such that the first and second extension-forming side walls are disposed between the sides of the gate elect rode and said first and second auxiliary side walls; andfirst and second source/drain regions separated by said channel region in the surface of said predetermined semiconductor region, whereinsaid gate insulating film, said gate electrode and said first and second source/drain regions define said transistor, andsaid source/drain regions include first and second extension regions which are shallower than other regions and are formed under said first and second extension-forming side walls.