Universal, semi-empirical MOSFET hole inversion layer mobility degradation models for use in circuit simulation programs such as SPICE are presented. By accurately predicting the mobility degradation due to acoustic phonon scattering and surface roughness scattering for p-channel MOSFETs at room temperature, these models eliminate the need for fitting parameters for each technology, which is required in the current SPICE level 3 model. The expressions reported accurately predict the mobility over a very wide range of channel doping concentrations, gate oxide thicknesses, gate voltage, and substrate bias, and they agree very well with recently published experimental mobility degradation data. When implemented in a circuit simulation code, these models will accurately determine the channel mobility in surface p-channel MOSFETs using only the channel doping concentration, gate oxide thickness, substate bias, and applied gate drive voltage as input parameters.>

Based on the physical insights provided by the universal mobility curve, an improved comprehensive universal model for effective electron mobility in inversion layers of n-channel MOSFETs is developed for circuit simulation. This model expresses the effective electron mobility at room temperature as a function of effective vertical field. It exhibits a high degree of accuracy for a wide range of different device characteristics, such as channel doping levels, gate oxide thicknesses, and channel dimensions. In addition, it predicts very well the effective mobility under the effects of substrate biases for gate voltages well above threshold, which is an improvement over earlier models. Moreover, this model has been developed with an emphasis on the functional dependence of mobility on high effective field, and is thus particularly accurate in that range of effective field. This is a significant advantage of the model since today's submicrometer MOSFETs typically operate at high effective fields.>