New method for assessment of depletion charge dependence of mobility in short-channel silicon MOS transistors

Abstract

An original method for the extraction of the depletion charge mobility dependency coefficient α based on the exploitation of the body-to-gate transconductance ratio gb/gm(Vg) MOSFET characteristics is presented. This method allows the demonstration of the fact that α is a parameter strongly dependent on channel length for both device types (p or n). Moreover, it is shown that the channel length reduction of a is closely correlated to that of the depletion charge to the gate oxide capacitance ratio Cd/Cox due to the increase of charge sharing effect when scaling down the devices.