Abstract: A body of semiconductor material having a first surface and a second surface spaced from the first surface includes a first layer along the first surface, a second layer along the second surface, a third layer between and contiguous to the first and second layers. The third layer is of a conductivity type opposite that of the first and second layers so as to form first and second P-N junctions respectively therebetween. The thickness of the third layer is at least twice the minority carrier diffusion length of the semiconductor material, so that carriers generated within the third layer have a high probability of being collected by one of the P-N junctions. The body includes means for electrically connecting the first and second P-N junctions and means for transferring the carriers collected at the first P-N junction to a portion of the first surface.

Abstract: Certain electrical characteristics of a semiconductor device which includes a body of semiconductor material are improved by exposing the semiconductor device to a substantially water vapor free atmosphere of chlorine and heating the device in this atmosphere.

Abstract: Epitaxial layers of silicon, having thicknesses of at least about 25 .mu.m, are grown on the (100) or (111) planar surfaces of silicon substrates by the vapor deposition of silicon from the reaction of dichlorosilane and hydrogen gas in a reactor furnace. Good epitaxial layers of silicon of substantially uniform thicknesses are formed on the substrates when the growth rate of the epitaxial layer is between about 5 and 20 .mu.m/minute in the reactor furnace, and the latter is heated to a temperature of between about 1050.degree. and 1200.degree.C.