Rapid thermal annealing effects on electrical and structural properties of Pd/Au Schottky contacts to n-type InP(111)

Abstract

The effects of rapid thermal annealing on the electrical and structural properties of Pd/Au Schottky contacts to n-type InP(111) have been investigated by current–voltage (I –V), capacitance–voltage (C –V) and X-ray diffraction (XRD) measurements. The barrier height of the as-deposited Pd/Au Schottky contact was found to be 0.46 eV (I –V) and 0.70 eV (C –V) respectively. It is observed that the Schottky barrier height increases with annealing temperature and found maximum values of 0.51 eV (I –V) and 0.92 eV (C –V) annealed at 400 °C for 1 min in the nitrogen atmosphere. However, after annealing the sample at 500 °C resulted in the decrease of barrier height and values are 0.40 eV (I –V) and 0.60 eV (C –V). The AFM results showed that the surface morphology of the contact annealed at 500 °C is fairly smooth with a RMS roughness 1.9 nm. Based on the XRD results, the formation of indium phases at the Pd/Au/n-InP interface could be the reason for the increase in the Schottky barrier height at 400 °C. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)