Investigation of hot carrier effects in n-MOSFETs thick oxide with HfSiON and SiON gate dielectrics

This paper reports the reliability characteristics of poly gated n-MOSFETs with HfSiON and SiON gate dielectrics in both thin and thick oxide of dual gate oxide scheme. Hot carrier stress (HCS) at Isub, max condition on thick oxide is found to be the most critical part among the various reliability concerns. Regardless of gate dielectric and gate oxide thickness, the degradation behavior of the condition of Isub, max and Vg=Vd HCS is mainly SS increase and Vth shift, respectively. Therefore, for precise evaluation of the device reliability, it is necessary that HC immunity at Isub, max stress should be checked in thick oxide transistor below 50 nm design rule era.