Patent ID: 7416967

Claim:
A method for manufacturing a semiconductor device comprising: forming a first gate insulation layer on a p-type semiconductor layer; forming a first polycrystalline silicon layer on the first gate insulation layer; forming a first source-drain region on a surface of the p-type semiconductor layer where the first polycrystalline silicon layer is sandwiched; performing an ion implantation of Ni into the first polycrystalline silicon layer; performing a heat treatment for forming a NiSi2 crystal nucleus in the first polycrystalline silicon layer at a temperature of 300° C. to 800° C.; forming on the first polycrystalline silicon layer a first Ni layer whose thickness is 5/18 to ½ with respect to the thickness of the first polycrystalline silicon layer; and transforming the first polycrystalline silicon layer into a crystal phase of NiSi2 by performing a heat treatment for growing the NiSi2 crystal nucleus at a temperature of 300° C. to 600° C.