Low-frequency noise in AlGaN/GaN HEMT structures with AlN thin film layer

Low‐frequency noise in AlGaN/GaN high electron mobility transistor (HEMT) heterostructures with additional AlN thin barrier layer is investigated. Transmission line model structures with different lengths of the conducting channel formed by polarization effects at the heterointerface of undoped AlGaN/AlN/GaN layers are studied. The measured noise demonstrates an unusual broadening of the generation‐recombination components of the spectra. To explain the noise behaviour of the structure we consider a model taking into account peculiarities of the band structure of the interface with inserted AlN high molar fraction barrier layer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)