Substrate for epitaxy

Abstract

The invention relates to a nitride single crystal block, which is a gallium nitride single crystal, and which has an area measured in a cross section perpendicular to the c-axis of the gallium nitride hexagonal crystal lattice of more than 100 mm2, a thickness of more than 0.1 mm, and a surface dislocation density in the C plane of less than 106 / cm2, while its volume is sufficient to form at least one further processable, non-polar A-plane or M-plane plate, preferably with a surface area of ​​at least 100 mm2, and can be produced by a process in which a Group XIII element is dissolved as a raw material in a supercritical solvent, and the selected gallium-containing nitride is crystallized on one of the surfaces of the crystal seed by supersaturating the supercritical solution with respect to the gallium-containing nitride by creating a temperature gradient or by changing the pressure. O