Determination of 2-D Electron-gas carrier mobility in short gate-length MODFET's by direct elimination of parasitic resistance effects

Two-dimensional (2-D) electron-gas carrier mobiliy in 1µm gate-length modulation-doped FET's has been determined as a function of the gate bias voltage. The measurement technique utilizes a small-signal gate voltage excitation and probes the true channel conductance by directly eliminating the source and drain series resistance effects. The mobility is extracted by combining the channel conductance data with the CV data and its variation with gate bias voltage is indicative of the variation of the effectiveness of screening of the ionized impurities and the quality of the MBE-grown GaAs buffer layer.