Low-frequency noise in reverse-biased Schottky barriers on InAlN/AlN/GaN heterostructures

Abstract

We present low-frequency gate noise characteristics of InAlN/AlN/GaN heterostructures grown by low-pressure metal-organic vapor phase epitaxy. The electric field in the InAlN barrier is determined from C-V measurements and is used for gate leakage current modeling. The latter is dominated by Poole-Frenkel emission at low reverse bias and Fowler-Nordheim tunneling at high electric field. Several useful physical parameters are extracted from a gate leakage model including polarizations-induced field. The gate noise fluctuations are dominated by trapping-detrapping processes including discrete traps and two continuums of traps with distributed time constants. Burst noise with several levels and time constant values is also observed in these structures. Low-frequency noise measurements confirm the presence of field-assisted emission from trap states. The 1/f noise model of McWorther is used to explain the 1/f-like noise behavior in a restricted frequency range.