Model of low-frequency noise and oscillations in GaAs metal-semiconductor-field effect transistors (MESFETs)

Abstract

We examine the theoretical and experimental aspects of low-frequency noise and oscillations in GaAs metal-semiconductor-field-effect transistors. We attribute the f−3/2 noise behaviour that is often observed in these devices to trap-modified diffusion in the semi-insulating substrate and review the derivation of analytical formulas for the spectrum. The low-frequency oscillations are correlated with the noise and we discuss the contribution to the noise from the random generation of slow domains in the substrate. We derive formulas to describe these oscillations in the drain current. Calculations using our model successfully imitate the experimental results for the noise and oscillations.