Epitaxial wafers avoiding edge melt-back-etching and method for fabricating the same

摘要

An epitaxial wafer 100, comprising a silicon substrate having a principal surface with a center region 110 and an edge region near an outer circumferential line of the principal surface, and a polycrystalline or amorphous edge-mask layer 120, which is made of a material suitable for growth of group-III-nitride material thereon and which is deposited directly and only on the edge region of the principal surface, such that the center region 110 and the edge-mask layer 120 together form a growth substrate for a group-III-nitride buffer layer 130 structure conformally deposited thereon.