Reliability considerations of strained silicon on relaxed silicon-germanium (SiGe) substrate

The process-induced I-V characteristics and reliability degradations for both nMOSFETs and pMOSFETs on strained Si have been fully characterized. Contrary to nMOSFETs, an apparent device reliability degradation of pMOSFETs at high temperature was observed. The degradation mechanism is attributed to SiGe substrate-induced donor-type interface state generation along the oxide/Si interface. From a manufacturing point of view, it is considered that not only the strain-induced misfit dislocations but also the MOSFETs' reliability degradations should be considered for strained-Si technology with SiGe substrate.