Simulation of current collapse in the 0.25 µm gate Length Al0.28Ga0.72N/GaN HEMT

A 2D drift-diffusion (DD) and Hydrodynamic (HD) transport models within ATLAS simulation toolbox by Silvaco have been calibrated against experimental I-V characteristics of the 0.25μm gate length GaN High Electron Mobility Transistor (HEMT). The simulations take into account both piezoelectric and spontaneous polarization effects at the interface of AlGaN and GaN. The simulations have been employed to investigate the current collapse phenomenon that plays a key role in the output characteristics of a device which can significantly limit the output power. The current collapse is investigated using shallow acceptor traps in the both AlGaN and GaN layers.