Study of low-temperature and post-stress hysteresis in high-k gate dielectrics

Abstract

In this work, we present the comparison of hysteresis behaviors of HfAlON and HfSiON high-k dielectrics at low-temperature and subjected to constant voltage stress (CVS). The V-FB instability in the HfAlON and HfSiON gate dielectric were deeply studied. A model is proposed to explain the V-FB Shift and hysteresis direction in thus two samples. We also treat the CVS voltage and CVS time dependence of hysteresis and V-FB Shift. The decreasing hysteresis with temperature is ascribed to traps generation/recombination rate reduction at low temperature.