Embedded source/drain SiGe stressor devices on SOL integrations, performance, and analyses

A detailed investigation of embedded source/drain SiGe stressors (eSiGes) on a silicon-on-insulator substrate for pMOS performance enhancement is presented. It is found that the integration with undoped SiGe epitaxy suffers strain relaxation from a postepitaxy implantation. SiGe growth with in situ doping is able to retain high strain for carrier mobility enhancement. For doped eSiGe integration with a proper thermal sequence, 20% pMOS drive current improvement is demonstrated. Quantitative analyses of contributions from mobility enhancement and device exterior resistance reduction to the performance improvement are also discussed.