Patent ID: 7808001

Claim:
A semiconductor device comprising: a semiconductor substrate; a first MOS transistor including a first gate insulation film formed on a first region of the semiconductor substrate, a first gate electrode formed on the first gate insulation film, a first sidewall formed of an insulating material on each side surface of the first gate electrode, fine particles of group IV semiconductor crystal implanted at least in part of the first sidewall and a first impurity doped region of a first conductivity type formed in part of the first region located at a side of the first gate electrode and the first sidewall; and a second MOS transistor including a second gate insulation film formed on a second region of the semiconductor substrate, a second gate electrode formed on the second gate insulation film, a second sidewall formed of an insulating material on each side surface of the second gate electrode so as to have a smaller thickness than a thickness of the first sidewall and a second impurity doped region of a second conductivity type formed in part of the second region located at a side of the second sidewall.