Patent ID: 8394690

Claim:
A fabrication method of a semiconductor device comprising: forming convex active areas on a surface region of a Si substrate by forming a plurality of trenches that are long in one direction and are formed in parallel in the surface region of the Si substrate, burying a first device isolation layer in the trenches, etching the surface regions of the convex active areas with the first device isolation layer used as a mask, growing a first semiconductor layer of Si 1-x Ge x (0<x<1) and a second semiconductor layer of Si 1-y Ge y (x<y≦1) in this order on the convex active areas with etched the surface regions, removing the first device isolation layer after growing the first and second semiconductor layers, narrowing a width of the second semiconductor layer in a direction perpendicular to the one direction and exposing a (110) plane perpendicular to the surface of the Si substrate to the side surface of the second semiconductor layer by etching the second semiconductor layer by an anisotropic wet etching method after removing the first device isolation layer, and burying a second device isolation layer in the trenches after etching the second semiconductor layer.