Dependence of ionization current on gate bias in GaAs MESFETs

Abstract

The nonmonotonic behavior of gate current I/sub g/ as a function of gate-to-source voltage V/sub gs/ is reported for depletion-mode double-implant GaAs MESFETs. Experiments and numerical simulations show that the main contribution to I/sub g/ (in the range of drain biases studied) comes from impact-ionization-generated holes collected at the gate electrode, and that the bell shape of the I/sub g/(V/sub gs/) curve is strongly related to the drop of the electric field in the channel of the device as V/sub gs/ is moved towards positive values.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>