Modeling of temperature dependence of the leakage current through a hafnium silicate gate dielectric in a MOS device

Abstract

The coupling between the longitudinal and transverse components of the electron thermal motion due to the difference between the effective electron mass of the hafnium silicate and silicon can explain the temperature dependence of the tunneling current through the hafnium silicate gate dielectric. By taking this coupling effect into consideration, the calculated tunneling currents under different temperatures fit well with the experimental data. The numerical calculations demonstrate that the temperature dependence of the tunneling current strongly depends on the thickness of the hafnium silicate gate dielectric. By comparing the results of the coupling effect on the tunneling current through the hafnium silicate film with those of the silicon dioxide layer, the coupling effect has been found to be more important for the case of hafnium silicate than that for the case of silicon dioxide.