Semiconductor substrate, semiconductor device, manufacturing method thereof, and method for designing semiconductor substrate

摘要

A semiconductor substrate, includes: a capacitance-adjusting semiconductor layer which is disposed in a predetermined region on a semiconductor substrate material and which is sufficiently thick and has a lower impurity density than that of the semiconductor substrate material; a first insulation film disposed on the capacitance-adjusting semiconductor layer; and a body layer made of a semiconductor disposed on the first insulation film.