| 摘要 |
PROBLEM TO BE SOLVED: To enhance anti-crack reliability and improve device characteristics by growing on a semiconductor substrate an intermediate layer the lattice constant of which is almost equal to that of a crystal layer, and the thickness of which reduces dislocation to a specified density or below, thinning the intermediate layer by etching, and growing the crystal layer thereon. SOLUTION: An intermediate layer 2 the lattice constant of which is almost equal to that of a crystal layer 3, and the thickness of which reduces dislocation density to 3×10<6> cm<-2> or below, is grown on a semiconductor substrate 1. The intermediate layer 2 is thinned by etching, and the crystal layer 3 is formed thereon. In this case, the disappearance of dislocation in the intermediate layer 2 occurs in proximity to the boundary between the intermediate layer 2 and the semiconductor substrate 1 as well as in proximity to the surface. For the reason, the dislocation density at the surface is reduced even if the intermediate layer 2 is thinned to a thickness at which cracking is hardly caused by thermal expansion. This obtains a crystal layer 3 excellent in crystallinity, and improves the characteristics and reliability of a semiconductor device.
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