Random telegraph signal noise in gate current of unstressed and reverse-bias-stressed AlGaN/GaN high electron mobility transistors

Random telegraph signal (RTS) fluctuations with relative amplitude up to 50% are observed in forward and reverse gate current of unstressed and reverse-bias-stressed AlGaN/GaN high electron mobility transistors. Measurements of RTS amplitude and mean pulse widths as a function of forward gate bias indicate that the RTS is due to modulation of current along an intrinsic or stress-induced percolation path across the AlGaN-barrier by electron capture and emission on a trap within the barrier. Processes of electron capture from GaN to trap and subsequent tunneling to metal gate or electron exchange between GaN channel and the trap are considered. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3701164]