Simulation of hot electron and quantum effects in AlGaN/GaN heterostructure field effect transistors

We report on simulations of electrical characteristics of AlGaN/(InGaN)/GaN heterostructure field effect transistors with quantum and hot electron effects taken into account. Polarization charges lead to quantum confinement of electrons in the channel and to the formation of two-dimensional electron gas. The electron quantization leads to the spread of the electron wave function into the barrier and bulk but does not have significant impact on dc electrical characteristics. Hot electrons play an important part in the charge transport by spilling over into the bulk GaN where they are captured by traps. This leads to negative differential conductivity, which is also observed experimentally. The simulation results are in good agreement with measured dc characteristics.