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

摘要

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) an-rnnealed at 400 ℃ for 1 min in the nitrogen atmosphere. However, after annealing the sample at 500 ℃ 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 ℃ is fairly smooth with a RMS roughness 1.9 nra. Based on the XRD results, the formation of indium phases at the Pd/Au-InP interface could be the reason for the increase in the Schottky barrier height at 400 ℃.