Simulation of electron tunneling in HEMT devices

We report results of 2D simulations of the electron tunneling through hetero-interfaces and gate Schottky contact in AlGaAs/InGaAs HEMT. For the first time the rigorous non-local tunneling models have been applied for heterostructure device simulations. The simulations have been performed within hydrodynamic transport model to account for hot electrons. The tunneling through hetero-interfaces fully controls the drain current. The tunneling through the Schottky barrier is responsible for the gate leakage and can significantly affect the transfer characteristics. Further, we have found that the breakdown characteristics of a HEMT are strongly affected by the gate leakage due to tunneling through the Schottky barrier. This effect may lead to a considerable underestimation of the HEMT breakdown voltage, when non-destructive measurement methods are applied.