Dielectrically isolated substrate and semiconductor device using the same

摘要

A dielectrically isolated substrate comprises a first semiconductor wafer, a second semiconductor wafer bonded on the first semiconductor wafer with a first insulating layer interposed therebetween, a semiconductor layer formed on the second semiconductor wafer, a first groove formed in the semiconductor layer and the second semiconductor wafer so as to reach the first insulating layer, thereby isolating the semiconductor layer and the second semiconductor wafer and a second insulating layer formed on the side face of the first groove or embedded in the first groove. In this dielectrically isolated substrate, a high breakdown voltage element and a low breakdown voltage element are formed in a region isolated by the first groove.