Patent ID: 8637938

Claim:
A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a gate insulating film on the semiconductor substrate; a gate electrode on the gate insulating film; a source region and a drain region of a second conductivity type in the semiconductor substrate; a first pocket region of the first conductivity type in the semiconductor substrate in contact with the source region; and a second pocket region of the first conductivity type in the semiconductor substrate in contact with the drain region, the second pocket region underlying from the gate electrode to a sidewall spacer, wherein the source region includes a first extension region having a concentration peak located at a first depth from a surface of the semiconductor substrate; and the first pocket region has a concentration peak located deeper than the first depth, and wherein the drain region includes a second extension region having a concentration peak located at a second depth from the surface of the semiconductor substrate, and the second pocket region has a concentration peak located shallower than the second depth.