High-field diffusivity and noise spectra in GaAs MESFETs

The paper investigates the impact of the high-field electron diffusivity model in GaAs on the simulated noise performances of metal semiconductor field-effect transistors (MESFETs). On the basis of a comparison between the numerical simulation, carried out through a two-dimensional implementation of the impedance-field method, and the noise power and correlation spectra measured on a 0.6 mu m low-noise MESFETs, it is shown that the intermediate and high-field behaviour of the diffusivity-field curve consistent with the experimental data is close to the one suggested in the study by de Murcia et al. (1991), while other experimental or Monte Carlo data overestimate the diffusivity and therefore the noise.