Influence of Interface Traps on MOSFET thermal coefficients and its effects on the ZTC current

Abstract

Interface degradation-induced shifts of MOSFET thermal coefficients and zero temperature coefficient current (IZTC) were studied by monitoring the interface traps (Nit) growth in a thick oxide n-channel MOSFET due to exposure to ionizing radiation, and to further annealing at room temperature. A new physics-based compact model was proposed to account for the observed results, and to predict the evolution of these parameters as interface traps are generated during stress. Within a range (0–40∘C) around room temperature, both the inverse of the mobility and the threshold voltage thermal coefficient varied roughly linear with Nit, with relative variations of 5.2×10−13eVcm2 and −9.33×10−13eVcm2, respectively. Furthermore, the dependence for IZTC with Nit can also be approximated to a linear expression, with a relative increment of 1.94×10−12eVcm2. The implications for temperature error mitigation in MOS sensors were discussed.