A Physically Based Accurate Model for Quantum Mechanical Correction to the Surface Potential of Nanoscale MOSFETs

Abstract

We present a physically based explicit analytical model for the quantum mechanical (QM) correction to the surface potential of nanoscale metal-oxide-semiconductor (MOS) devices. The effect of wave function penetration into the gate dielectric is taken into account. Instead of using the band-gap widening approach, which indirectly includes QM correction, the proposed correction term is directly added to the semiclassical surface potential. Under accumulation bias, charges in extended states and quantized states contribute to the surface potential in different ways. The proposed QM correction considers this difference in contributions. Comparison with two existing analytical QM correction models and two self-consistent QM numerical models show that the proposed correction is more accurate than the existing analytical models. The improvement achieved under the accumulation bias is particularly significant. The gate C-V characteristics of a number of different MOS devices have been simulated using the proposed correction. Excellent agreement with published experimental data has been observed.