Investigation and modeling the surface mobility of MOSFETs from -25 to +150 degrees C

The surface mobility of n- and p-channel MOS transistors with varying densities of oxide charge and interface states has been investigated at low drain voltage in the temperature range from -25 to 150 degrees C. Mobility values were extracted from DC transfer characteristics using the Pao-Sah drain current model and taking into account interface-state charge and short-channel effects. The dependence of the surface mobility is calculated using a partly diffuse scattering model. The influence of oxide and interface state charges on current transport is modeled by screened Coulomb potential scattering and by surface potential fluctuation, which saturates for charge densities larger than 6.25*10/sup 10/ cm/sup -2/.>