Dc electrical oxide thickness model for quantization of the inversion layer in MOSFETs

Abstract

A simulator using the coupled Schrödinger equation, the Poisson equation and Fermi-Dirac statistics to analyse inversion-layer quantization has been shown to match the measured C-V data of thin-gate-oxide metal-oxide semiconductor (MOS) capacitors closely. This simulator is used to study in detail the effects of bias voltage, oxide thickness and doping concentration on the charge centroid and from this a simple empirical model for the dc charge centroid of the inversion layer is proposed. This model predicts the inversion charge density in terms of Tox, Vt and Vg explicitly and can be used to estimate transistor current in device engineering and circuit simulation models.