In formation manner of the semiconductor substrate and the electric field effective die transistor and SiGe formation and formation manner of the deformation Si formation which uses this and on the production mannered null Si substrate

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor substrate with a low feedthrough dislocation density and surface roughness, a field effect transistor, a forming method of an SiGe layer and a forming method of a distorted Si layer using the same, and to provide a manufacturing method of the field effect transistor.;SOLUTION: The semiconductor substrate is provided with, on an Si substrate, an SiGe buffer layer on which a plurality of SiGe inclined composition layers in which a composition ratio of Ge is gradually increased toward the surface are laminated. Each of these inclined composition layers is constituted so that a compositional ratio of Ge of the lower layers of upper inclined composition layers of the two adjacent inclined composition layers is larger than that of the upper layers of lower inclined composition layers.;COPYRIGHT: (C)2003,JPO