The electrostatics of InSb double-gate MOSFETs is simulated using a self-consistent solver which calculates channel bandstructure and carrier population by tight-binding (TB) approach. The
characteristic and the Quantum Confinement Stark Effect (QCSE) are evaluated. By comparing with the results from the
k · p
method and effective mass approach, we show that full-band approach based on TB becomes more desirable when the channel is scaled down to a low dimensional quantum well. As the consequence of narrow channel width it is observed that the density of states (DOS) near band edges is decreased.