Analytical Model of Gate to Channel Capacitance for Nanoscale MOSFETs

We present an analytical model for gate to channel capacitance,CGC, in nanoscale metal oxide semiconductor field effect transistors. The model incorporates quantum mechanical effects, drain-induced barrier lowering and short channel effects. While the charge density in the channel is evaluated using two-dimensional density of states, the average separation charges from the interface are determined from the solution of Schrodinger's wave equation. We evaluate the average separation of charge carriers from the silicon-silicon dioxide interface, which facilitates the evaluation ofCGC. The calculated wavefunction gives a non-zero value at the Si-SiO(2)interface, which has a significant effect onCGCvis-a-vis the obtained value when the zero wavefunction is used. The evaluatedC(GC)is seen to be in reasonable agreement with the self-consistent results of Harelandet al. and van Dort's model.