Patent ID: 8633516
Filing Date: 2014-01-21
Classification: H01L

Abstract:
1. A semiconductor device comprising: a substrate; a fin formed by a first semiconductor material have a first lattice constant on the substrate; a gate region formed on a portion of the fin on the substrate; a source region and a drain region separated by the gate region on the substrate; a source/drain stack having a thickness (T) on the source and drain region; a second semiconductor material, having a second lattice constant, as a bottom portion of the source/drain stack and contacting a low portion of the fin in the gate region, wherein the second lattice constant is substantial smaller than the first lattice constant; and a third semiconductor material, having a third lattice constant and a thickness (t), on top of the second semiconductor material as an upper portion of the source/drain stack and contacting an upper portion of the fin in the gate region, wherein the third lattice is larger or equal to the first lattice constant.