Reliability studies on biaxially tensile strained-Si channel p-MOSFETs

Abstract

An integrated technology computer aided simulation framework is used for the first time to predict the reliability (degradation) of substrate-induced strained-Si channel heterojunction field effect transistors on relaxed Silicon-Germanium buffer layer with ultra-thin SiO2 and high-k gate stacks. State-of-the-art four-state nonradiative multiphonon model is used for the degradation studies. Single defects and trap studies have been taken up on devices subjected to negative voltage stressing at an elevated temperature. Threshold voltage shift (due to charge capture and emission processes) in virtually fabricated devices has been studied in detail. For the first time, non radiative multiphonon model is used to explain the degradation mechanisms (oxide defects dominating the partial recovery of threshold voltage after stressing) in strained-Si channel heterojunction field effect transistors. It is shown that degradation in strained-Si channel device on relaxed-SiGe buffer is more compared to its Si-channel counterpart.