Rapid thermal annealing temperature dependence of noise properties in Au/n-GaAs Schottky diodes with embedded InAs quantum dots in asymmetric In0.2Ga0.8As wells

Abstract

The effect of rapid thermal annealing temperature on the trap properties of Au/n-GaAs Schottky diodes with embedded InAs quantum dots in asymmetric In0.2Ga0.8As wells have been investigated by capacitance-voltage (C -V) and low frequency noise (LFN) measurements in both reverse and forward bias regimes. The current noise spectra show 1/f behaviour and generation-recombination (g-r) noise, attributed to uniformly distributed traps in energy and to a discrete trap level in the energy band-gap of the GaAs capping layer, respectively. The experimental results show that the annealing temperature is closely related with the level of these noise sources. The apparent doping concentrations, calculated from the C -V characteristics, indicate that the density of trapping states near the buffer layer interface is increased as the annealing temperature increases. (c) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim