Patent ID: 7465499

Claim:
A boron phosphide-based semiconductor device comprising: a silicon single crystal substrate ( 11 ); a boron phosphide-based polycrystalline layer formed on a {111} surface of said substrate; and a group III-V compound semiconductor layer stacked on said boron phosphide-based polycrystalline layer to form a hetero junction on the boron phosphide-based polycrystalline layer; wherein the boron phosphide-based polycrystalline layer is composed of an aggregate of a plurality of triangular pyramidal or truncated triangular pyramidal single crystal entities ( 13 ); each of said entities having a {111} bottom face ( 13 a ) that is parallel to said {111} surface of the substrate, having {111} side faces ( 15 ) and having a twinning interface that forms an angle of 60° relative to a <110> direction of said substrate; and wherein the group III-V compound semiconductor layer is composed of crystal planes arrayed at an interval agreeing with a lattice spacing of crystal planes intersecting with surfaces of the single crystal entities ( 13 ).