Impact ionisation in strained SiGe pMOSFETs

Impact ionisation in compressively strained Si/sub 0.64/Ge/sub 0.36/ pMOSFETs is investigated. Despite the smaller bandgap and higher hole mobility, impact ionisation is found to be reduced in strained SiGe. This is attributed to the reduced density of states in strained SiGe, brought about by strain-induced band splitting, limiting the opportunities for scattering.