Modelling of tunnelling currents in Hf-based gate stacks as a function of temperature and extraction of material parameters

Abstract

In this paper we show that through electrical characterization and detailed quantum simulations of the capacitance-voltage and current-voltage characteristics it is possible to extract a series of material parameters of alternative gate dielectrics. We have focused on HfO2 and HfSiXOYNZ gate stacks and have extracted information on the nature of localized states in the dielectric responsible for a trap-assisted tunneling current component and for the temperature behavior of the I-V characteristics. Simulations are based on a 1D Poisson-Schrdinger solver capable to provide the pure tunneling current and Trap Assisted Tunneling component. Energy and capture cross section of traps responsible for TAT current have been extracted.