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 l/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.