Comparative analysis of hot-electron transport in AlGaN/GaN and AlGaN/AIN/GaN 2DEG channels

Nanosecond-pulsed current-voltage measurements were used to study hot-electron transport in undoped AlGaN/GaN and AlGaN/AlN/GaN two-dimensional electron gas channels biased up to 200 kV/cm. Voltage pulses of 1 ns were applied in order to minimize channel heating. The current saturated at 100 kV/cm in the AlN-interbarrier-contained structures; the estimated saturated drift velocity was about 1.1 x 10(7) cm/s. No saturation of the current was observed in AlGaN/GaN channels in the field range below 200 kV/cm. Monte Carlo simulation of hot-electron transport was carried out with electron gas degeneracy and hot phonons taken into account. A fairly good fit of the experimental results with the Monte Carlo simulation data was obtained in the electric field range up to 30 kV/cm. (c) 2005 WILEY-VCH Verlag GmbH & Co.