Ideality factor dependence of capacitance and reverse current noise in Au/n‐GaAs Schottky diodes with embedded self‐assembled InAs quantum dots

Abstract

The trap properties of Au/n‐GaAs Schottky diodes with embedded InAs quantum dots (QDs) and different ideality factors were studied by capacitance‐voltage (C‐V) and low‐frequency noise (LFN) measurements in the reverse bias regime. The reverse current noise spectra show 1/f behaviour and g‐r noise, attributed to uniformly distributed traps in energy or to a discrete trap level in the energy band‐gap of the GaAs capping layer, respectively. The Schottky contact performance or characteristics is closely related with the level of these noise sources. The C‐V characteristics indicate the existence of traps with Gaussian energy distribution in the GaAs capping layer and in the InAs QDs layer. From analysis of the C‐V characteristics, the density and the activation energy of these trap distributions are determined. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)