This paper presents a semianalytical model developed for the ON state (V-G
> V-T) Of trench gate MOSFETs. It incorporates a more realistic model for t
he inversion channel region, taking the effects of doping variation, transv
erse, and longitudinal electric fields including the surface scattering, in
to consideration. Accurate modeling of the inversion channel region is of p
aramount importance, especially in the case of low voltage power devices wh
ere the inversion channel resistance is a significant portion of the overal
l resistance. The carrier velocity saturation at high longitudinal electric
fields is also taken into account in the formulation of the model. The pro
posed model is supported by both numerical simulation results using MEDICI
and experimental results, which are in good agreement with the results of t
he model. This can be a useful tool in the design of optimum devices.