Mobility degradation due to the gate field in the inversion layer of MOSFET´s

A simple classical theory that explains how the carrier mobility degrades as a function of the gate field in the inversion layer of MOSFET\´s is presented here. A formula of effective gate field-dependent mobility is derived and is reducible to the well-known empirical formula at the limit of large gate oxide thickness. However, their difference becomes drastic at thin gate oxide and high gate fields. For example, at Å, and V, the difference is about 20% for mobility prediction if same physical parameters are used in both formulae. The present theory has been incorporated into a new model for characteristics of MOSFET\´s and good agreements with experimental data for Å transistors have been observed.