Patent ID: 7629243

Claim:
A method for manufacturing a semiconductor device comprising: forming a gate insulating film on a semiconductor substrate; forming an In-rich layer having a thickness ranging from 0.5 to 1.5 atomic layer through the deposition of In or InB on the gate insulating film; forming a first layer on the In-rich layer, the first layer containing an amorphous or polycrystalline formed of Si 1-x Ge x (0≦x<0.25) and containing In as a first p-type impurity; subjecting the first layer to a first heat treatment wherein the first layer is heated for 1 msec or less at a temperature higher than 1100° C. or the first layer is irradiated with laser having an energy density of 1.5 J/cm 2 or more for 15 nsec or less to laser-anneal the first layer, a solid solution limit of the first p-type impurity in the first layer after the first heat treatment being enhanced up to 2×10 20 /cm 3 ; forming a second layer on the first layer, the second layer containing B as a second p-type impurity and formed of amorphous silicon or polycrystalline silicon, the second p-type impurity having a smaller covalent bond radius than that of the first p-type impurity; and subjecting the second layer to a second heat treatment to heat the second layer at a temperature ranging from 800° C. to 1100° C.