SOURCE AND DRAIN STRESSORS WITH RECESSED TOP SURFACES

摘要

An IC structure includes a gate stack on a semiconductor substrate, and a silicon germanium region which is extended into the semiconductor substrate and is adjacent to the gate stack. The silicon germanium region has an upper surface. The center part of the upper surface is recessed from the edge part of the upper surface to form a recess. The edge part is in the opposite side of the center part.