Modeling of Temperature-Dependent MOSFET Aging

Abstract

We have modeled MOSFET-device aging based on the trap-density increase, which is included in the Poisson equation to consider aging explicitly and physically correct. To preserve consistency, the Poisson equation is solved iteratively. Measured temperature dependence of aged I-V characteristics are well reproduced with implementation of this aging model into the industry-standard model HiSIM. The extracted physical device quantities with the developed model from measurements have been investigated to characterize the aging features. It is observed that the activation energy Ea as a function of Vgs is nearly identical for non-aged and aged devices. This concludes that the temperature dependence of aging originates mostly from the temperature-dependent electrostatic potential, resulting in negligible temperature dependency of extracted trap density Ntrap. To generalize the conclusion, 2D-device simulation is investigated for a double-gate (DG) MOSFET with increased stress-induced trap density. The same results as obtained from measurements are achieved, namely the activation energy is nearly identical for either non-aged or aged cases. This concludes that the temperature dependence of device aging can be accurately predicted using the temperature-dependent I-V characteristics of non-aged device.