Method of diffusing P type impurity

摘要

A method of diffusing a P type impurity into a semiconductor substrate includes selectively implanting ions of a first P type impurity into a semiconductor substrate and thermally diffusing a second P type impurity into the semiconductor substrate at least in a region where the first P type impurity ions are implanted. The diffusion speed of the P type impurity is increased in the ion implantation region whereby a P type impurity diffusion region which nearly corresponds in extent to the ion implantation region is obtained. The P type diffusion region can be precisely produced with a high dopant impurity concentration.