Patent ID: 8878244
Filing Date: 2014-11-04
Classification: C23C,C30B,H01L

Abstract:
1. A semiconductor device, comprising: a semiconductor substrate; a silicon-germanium film epitaxially grown over said semiconductor substrate, the silicon-germanium film having a thickness of about 3 to 4 μm; and a silicon film epitaxially grown over and in contact with said silicon-germanium film and constituting a channel region of an FET, wherein a concentration distribution of germanium along a thickness of said silicon-germanium film has a peak in an intermediate region along the thickness of said silicon-germanium film, and wherein, as considered along the thickness of said silicon-germanium film in a direction from said substrate toward said silicon film, the concentration distribution of germanium increases gradually from a vicinity of a first interface at a substrate side of said silicon-germanium film, once decreases gradually in a direction toward a second interface between the silicon-germanium film and the silicon film after having once reached said peak in said intermediate region, and thereafter remains substantially constant to a vicinity of the second interface, and where the concentration distribution of germanium remains substantially constant to the vicinity of the second interface, the thickness of the silicon-germanium film is about 1.5 to 2 μm.