Patent ID: 7052979

Claim:
A method for producing a semiconductor crystal in which a semiconductor substrate is formed by growing a semiconductor crystal A comprising group III nitride compound semiconductor on a base substrate, which is made of silicon (Si), by using lateral crystal growth, comprising: a reaction prevention process for forming a reaction prevention layer, which is made of a material B whose melting point is higher than that of the semiconductor crystal A, on said base substrate; a projection part forming process for forming numbers of projection parts from said reaction prevention layer by employing chemical or physical etching, without exposing the side of said base substrate on which said reaction prevention layer is formed; and a crystal growing process wherein at least a portion of the surface of said projection part is used as an initial growth surface on which crystal growth of said semiconductor crystal A starts first, and said semiconductor crystal A is formed by crystal growth until each growth surface is connected to become a series of an approximately flat surface, wherein AlGaN, AlInN, or AlGaInIN, in which aluminum composition ratio is at least 0.30 or more, is used as monocrystalline material B forming said reaction prevention layer.