ELECTRON-DRIFT VELOCITY VERSUS ELECTRIC-FIELD IN GAAS

In assessing the performance of small, high-speed GaAs devices, it is very important to know the behavior of the drift velocity of electrons and holes vs electric field for various temperatures, doping concentrations, channel inversion fields, etc. , for transient as well as steady-state conditions. For this reason, many experimental and theoretical studies have been devoted to determine these dependences. Theoretical calculations are reliable only for fields lower than 15 kV/cm. Often the complexities of competing processes in complicated geometries necessitate expressing these results empirically. In this paper, we suggest an empirical formula, which only contains several physical parameters, to accurately approach the behavior of the electron drift velocity vs electric field in GaAs. We also show its application in the analytical model of GaAs FET.