A semiconductor device including a substrate, a first body of a semiconductor material epitaxially deposted on the surface of the substrate and a second body of a semiconductor material epitaxially deposited on the first body. The first body is deposited so as to include a plurality of superimposed epitaxial layers having growth interfaces between adjacent layers so that each of the layers has fewer crystal dislocations than the adjacent layer which is closer to the substrate and the layer adjacent the second body has the fewest crystal dislocations. The second body is of a semiconductor material which has a crystal lattice which substantially matches the crystal lattice of the semiconductor material of the first body.