III group nitride based semiconductor element and method for manufacture thereof

摘要

A separator layer of Ti is formed on an auxiliary substrate of sapphire or the like. An undercoat layer of TiN is formed on the separator layer. The undercoat layer is provided so that a Group III nitride compound semiconductor layer can be grown with good crystallinity on the undercoat layer. TiN is sprayed on the undercoat layer to form a thermal spray depositing layer. Then, the separator layer is chemically etched to reveal the undercoat layer. Then, a Group III nitride compound semiconductor layer is grown on a surface of the undercoat layer.