US Patent 8633516 Source/drain stack stressor for semiconductor device

The present disclosure provides a semiconductor device. The device includes a substrate, a fin structure formed by a first semiconductor material, a gate region on a portion of the fin, a source region and a drain region separated by the gate region on the substrate and a source/drain stack on the source and drain region. A low portion of the source/drain stack is formed by a second semiconductor material and it contacts a low portion of the fin in the gate region. An upper portion of the source/drain stack is formed by a third semiconductor material and it contacts an upper portion of the fin in the gate region.