Patent ID: 8110848

Claim:
A single crystal substrate used for opto-electric or electrical devices which comprises a layer of nitride grown by vapor phase epitaxy growth wherein the nitride substrate includes a first crystalline growth surface and a second crystalline growth surface, and the first crystalline growth surface is substantially consisting of a non N-polar face and the second crystalline growth surface is substantially consisting of an N-polar face, and a dislocation density of the substrate is 5×10 5 /cm 2 or less, wherein the substrate has a thickness of 100 μm or more, which is sliced from a portion of at least one of B 1 ) a layer of nitride grown by MOCVD or MBE and B 2 ) a layer of gallium-containing nitride grown by HVPE, in combination layers of A) a layer of bulk mono-crystal nitride containing at least one element selected from alkali metals of Na, K, Rb and Cs, and at least one of the layers B 1 ) and B 2 ).