| 摘要 |
PROBLEM TO BE SOLVED: To enable in a short time and easy the formation of a shallow P-type semiconductor region, having relatively high impurity concentration and a deep P-type semiconductor region having relatively low impurity concentration. SOLUTION: In this manufacturing method, a liquid impurity material source 2 composed of mixed material of aluminum, boron and organic solvent is spread on the surface of an N-type semiconductor substrate 1 and heated at a temperature lower than the diffusion temperature of aluminum, the organic solvent is vaporized, and a layer containing aluminum and boron is formed. The layer is thermally treated in an atmosphere containing oxygen. After that, thermal treatment is performed at a temperature higher than that of this thermal treatment, aluminum and boron are diffused in the N-type semiconductor substrate 1, and first and second P-type semiconductor regions 7, 8 different respectively in impurity concentrations are formed.
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