Abstract: A transparent electrode is provided on a glass substrate, and an amorphous silicon layer is provided on the transparent electrode. A nickel layer as a metal catalyst element is provided in or so as to contact with the surface of the amorphous silicon layer, followed by heat treatment to crystallize the amorphous silicon layer, thereby forming a p-type polycrystalline silicon layer. This polycrystalline silicon layer is crystallographically oriented and has high crystallinity. The polycrystalline silicon layer is used as a seed crystal to form a p-type polycrystalline silicon layer which is crystallographically oriented and, at the same time, has high crystallinity. Further, an i-type polycrystalline silicon layer and an n-type polycrystalline silicon layer are successively formed on the polycrystalline silicon layer.

Abstract: A plurality of linear catalytic metal element portions are arranged at predetermined intervals just on or just beneath an amorphous silicon layer, and, in this state, the amorphous silicon layer is heat treated to crystallize the amorphous silicon layer and consequently to form a polycrystalline silicon layer. This construction can realize the provision of a method for the formation of an evenly oriented, high-quality crystalline silicon layer in a large area, and a crystalline silicon semiconductor device produced by this method.

Abstract: Concave and convex are formed on the substrate 1, the amorphous silicon layer 4 is formed on the metallic catalyst 3 dispersed and arranged in a dotted shape in the concave portion of the concave and convex, the crystal phases 5 having respective orientations from the metallic catalyst 3 are grown, further the crystal phases 5 are integrated with each other by continuing heat treatment and the polycrystalline silicon layer 6 is formed. A crystalline silicon semiconductor device and its method for fabrication which are costly advantageous and capable of efficiently forming the polycrystalline silicon layer of a predetermined thickness needed as a semiconductor device are provided.