Capacitance characterization of AlN/GaN double‐barrier resonant tunnelling diodes

Abstract

Abstract We report on the electrical characterization of AlN/GaN/AlN double‐barrier resonant tunnelling diodes (RTDs) using steady‐state current‐voltage and capacitance‐voltage (C‐V) characteristics in a wide frequency range with 2 kHz steps. The C‐V characteristics of a double‐barrier RTD show different behaviour under forward and reverse polarities and a strong dependence on frequency. The monotonous growth of capacitance at forward bias was registered, while a more complicated dependence was observed at reverse voltages. In order to analyse this dependence, a self‐consistent calculation of the potential profile of the structure was performed taking into account polarization effects at the AlN/GaN interfaces. The peculiarities are analysed in the model of possible charge trapping at the interface states. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)