Patent ID: 8067776
Filing Date: 2011-11-29
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a semiconductor substrate having an upper epitaxial layer with a first surface; a hetero semiconductor region including a semiconductor material having a band gap different from that of the semiconductor substrate and contacting a first portion of the first surface of the semiconductor substrate; and a first insulating film of a silicon oxide on a second portion of the first surface of the semiconductor substrate not contacted by the hetero semiconductor region and on a side surface and upper surface of the hetero semiconductor region; wherein the second portion of the first surface of the semiconductor substrate has an oxidized portion extending from the first surface to a depth less than a thickness of the upper epitaxial layer and the side and upper surfaces of the hetero semiconductor region have an oxidized portion extending from the side and upper surfaces to a depth less than a thickness of the hetero semiconductor region; and wherein the oxidized portions of the semiconductor substrate and the hetero semiconductor region form a second insulating film beneath the first insulating film.