To reduce a thickness of a metamorphic layer caused by diffusion/segregation of In in the hetero-interface between a compound semiconductor including In and a compound semiconductor not including In. Inを含む化合物半導体とInを含まない化合物半導体とのへテロ界面におけるInの拡散/偏析による変成層を少なくする。 - 特許庁