Disclosed herein is a process for producing a single crystal layer of a semiconductor device, which comprises the steps of providing an oxide insulator layer separated by an opening part for seeding, on a major surface of a single crystal semiconductor substrate of the cubic system, providing a polycrystalline or amorphous semiconductor layer on the entire surface of the insulator layer inclusive of the opening part, then providing a protective layer comprising at least a reflective or anti-reflection film comprising strips of a predetermined width, in a predetermined direction relative to the opening part and at a predetermined interval, the protective layer capable of controlling the temperature distributions in the semiconductor layer at the parts corresponding to the stripes or the parts not corresponding to the stripes, thereby completing a base for producing a semiconductor device, thereafter the surface of the base is irradiated with an energy beam through the striped reflective or anti-reflection film to melt the polycrystalline or amorphous semiconductor and scanning the energy beam in a predetermined direction such that the direction of the crystal of the semiconductor re-solidified and converted into a single crystal accords with a {111} plane, to produce the single crystal of the semiconductor device. Also disclosed is a semiconductor device produced by the method, which comprises a single crystal layer having a wide range of a crystal in a predetermined direction relative to the facial orientation of the major surface of the substrate, and has a three-dimensional semiconductor circuit element construction.