Abstract: A fabrication method of a semiconductor device with the CMOS structure, which suppresses the sheet resistance of silicide layers of a refractory metal in an n-channel MOSFET at a satisfactorily low level while preventing the junction leakage current in a p-channel MOSFET from increasing. An n-type dopant is selectively ion-implanted into surface areas of a first pair of n-type source/drain regions and a surface area of a first gate electrode in an NMOS region at a first acceleration energy, thereby forming a first plurality of amorphous regions in the NMOS region. The n-type dopant is ion-implanted into surface areas of the second pair of p-type source/drain regions and a surface area of the second gate electrode in a PMOS region at a second acceleration energy lower than the first acceleration energy, thereby forming second plurality of amorphous regions in the PMOS region.