A new model for simulating the reverse shea channel effect and capacitance-voltage (C-V) characteristics of metal-oxide-semiconductor (MOS) transistors has been developed. Due to ion-implantation and stress effects, the interface between Si and SiO2 in the model described here has been assumed to be a nonuniform sink of interstitials. The simulator ALAMODE and the two-dimensional (2D) process simulator TSUPREM4 were used to simulate doping profiles of n-channel MOS (NMOS) devices. Using simulated 2D doping profiles, the threshold voltage and C-V curves of NMOS devices were calculated. We show comparisons of the threshold voltage, C-V curves, and channel doping profiles for extracted profiles using inverse modeling techniques and those simulated by ALAMODE and TSUPREM4. Using default model parameters in TSUPREM4, the doping profiles did not match extract ed doping profiles well, but with the model described here incorporated into TSUPREM4 using calibrated model parameters, a good match between measurements and simulations was observed. The body effect and C-V characteristics of NMOS devices are quantitatively predicted using parameters obtained from matching of experimental threshold voltage data. We describe the model and implementation and discuss the physical significance of the new model.