Patent ID: 7045417

Claim:
A method of manufacturing a semiconductor device, which comprises: forming a first semiconductor film including polycrystalline silicon or amorphous silicon on a surface of a semiconductor substrate; adsorbing a first impurity on a surface of the first semiconductor film; adsorbing a second impurity on the surface of the first semiconductor film having the first impurity adsorbed thereon; forming a second semiconductor film made of polycrystalline silicon or amorphous silicon on the surface of the first semiconductor film having the first and second impurities adsorbed thereon; and solid-phase-diffusing the first impurity and the second impurity into a region of the semiconductor substrate which is located adjacent to the first and second semiconductor films to thereby form a first diffusion region containing the first impurity and a second diffusion region containing the second impurity, a concentration of the first impurity in said first diffusion region being higher than that of the second impurity in said second diffusion region, and said first diffusion region having the bottom thereof covered by said second diffusion region.