Method of manufacturing semiconductor device having trench isolation

摘要

A semiconductor device includes a plurality of circuit portions of different functions each constructed by including a MOS transistor on an SOI substrate obtained by sequentially stacking a semiconductor substrate, a buried insulating film and a semiconductor layer. The semiconductor device includes first and second portions. The first circuit portion is isolated by being surrounded with a first insulating film provided on an upper portion of the semiconductor layer and a second insulating film penetrating the semiconductor layer to reach the buried insulating film.