COMPARISON OF WURTZITE AND ZINC BLENDE III-V NITRIDES FIELD-EFFECT TRANSISTORS - A 2D MONTE-CARLO DEVICE SIMULATION

An ensemble Monte Carlo method is used to compare the potentialities o f zinc blende and wurtzite GaN for field effect transistor application s. First, bulk material electron transport properties are compared and we find that mobility, steady state velocity and velocity overshoot a re at the advantage of zinc blende GaN. Then, zinc blende GaN and wurt zite GaN MESFET with very short gate length (L-g = 0.12 mu m) are inve stigated using a 2D Monte Carlo device simulation. A 50% gain in perfo rmance is obtained for the zinc blende GaN MESFET as compared with the wurtzite one. A zinc blende AlGaN/GaN HEMT is also simulated and exhi bits a current density of 900 mA mm(-1), a transconductance of 480 mS mm(-1) and a cut-off frequency of 180 GHz. (C) 1997 Elsevier Science S .A.