SOI SUBSTRATE

摘要

The purpose of the invention is to provide an SOI substrate for a power semiconductor device which does not contain rare metals and has no cooling mechanism, by simultaneously solving both the problems relating to conventional SOI substrates in which a carbon film is used as an insulating layer (I layer) and the problems relating to diamond synthesis by the HFCVD method. The SOI substrate for a power semiconductor device can be provided having a high withstand voltage and high thermal conductivity by making the SOI substrate an I layer having a hybrid construction of a carbon film and microcrystalline diamond film, or more preferably by making the SOI substrate an I layer further provided with a silicon oxide film (SiO2 film) between a silicon substrate and the carbon film.