Discrimination between two noise models in metal-oxide-semiconductor field-effect transistors

Abstract

In order to discriminate between the number‐fluctuation and the mobility‐fluctuation noise models of 1/f noise in metal‐oxide‐semiconductor field‐effect transistors, the drain‐flicker‐noise spectral intensity SI_d (f) was measured as a function of drain bias V_d from low values of V_d through saturation (V_d≳V_ds). Chiefly because of the hot‐electron effects in mobility‐fluctuation noise at high fields, discovered by Bosman, Zijlstra, and Van Rheenen, the theoretically predicted dependence of SI_d (f) upon V_d differs for the two models. Data on some metal‐oxide semiconductor (MOS) devices agree better with the number‐fluctuation model, whereas other MOS devices, e.g., those made by shallow ion implantation, agree best with the mobility‐fluctuation model. In these cases the temperature dependence of the noise also agrees with the mobility‐fluctuation model.