Magnetotransconductance profiling of mobility and doping in GaAs MESFETs

Electron mobility profiles of GaAs MESFETs have been measured using the magnetotransconductance technique and corrected using in situ measurements of parasitic resistances. It is shown that with this technique both mobility and carrier density profiles versus depth can be calculated without C-V data. This enables complete mobility and carrier density profiles to be obtained on short-gate-length packaged devices without the inherent difficulties of the C-V method and its attendant inaccuracies near the active layer-substrate interface. The results for two commercial packaged devices at room temperature, which indicate mobilities of 3500 to 4500 cm/sup 2//V/s and peak carrier concentrations of 1.2 to 2.0*10/sup 17/ cm/sup -3/, are given.<>