PURPOSE: To effectually avoid deterioration of crystal of a plurality of semiconductor layers by irradiating as a heat treatment only a region, into which impurity is introduced, of one semiconductor layer among the plurality of semiconductor layers with laser light.

CONSTITUTION: A semiconductor laminate 2 yielded by laminating semiconductor layer 3-8 is formed on a semiconductor substrate 1. An insulating film 13 is formed on the semiconductor laminate 2, and impurity ion for a p type is implanted to form an impurity introduced region 6b in the region 6a in which the impurity for a p type is introduced at a high concentration, utilizing the region 6a of the semiconductor layer 6 possessing a less thickness than other regions. Only the impurity introduced region 6b is irradiated with laser light 51 to be subjected to a heat treatment. Thus, an activated region 6c is formed. Hereby, the semiconductor layers 3-8 are fabricated without causing any deterioration of crystal.