  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.
