InxGa1−xSb n-channel MOSFET: Effect of interface states on C-V characteristics

The Capacitance-Voltage (CV) characteristics of InGaSb based n-MOSFET are investigated by quantum mechanical calculation solving 1D self-consistent Schrodinger-Poisson equation using Silvaco's ATLAS device simulation package. The charge density profile is determined by wave function penetration effect within the oxide layer and Neuman boundary condition. Low and high frequency CV characteristics are studied both for the positive and negative interface charge densities. The results obtained from the simulation demonstrate that the CV characteristics are not so sensitive in the shift of threshold voltage for high frequency operation. On the other hand, a significant shift in threshold voltage is noticed for the low frequency operation and the shift is entirely depends on the density of interface charge density and its type.