NUMERICAL-SIMULATION ON THE DEVICE STRUCTURE OF GAAS FLOATED ELECTRON CHANNEL FIELD-EFFECT TRANSISTOR

Abstract

In order to characterize the performance and design the optimal structure of the GaAs floated electron channel field-effect transistor (FECFET), we have carried out two-dimensional numerical simulation with varying the values of the key structure parameters of the FECFET. In the simulation, the uniform distribution of surface state charges on triangular void wall and the electron saturation velocity as a function of gate length are taken into account. It is shown from the simulation that the GaAs FECFET has an effective channel length of about 0.5 mu m and the vertical distance between the top vertex of void and the Ohmic layer front affects the channel length. When the gate-length-dependent saturation velocity is considered, the simulated current-gain cut-off frequency of the FECFET is linearly proportional to the reciprocal of the metallized gate length. When the gate is misaligned toward the drain direction, the transconductance values of the FECFET more abruptly decrease than in the case of misalignment toward the source direction.