Electrical and structural properties of Pd/V/n-type InP (111) Schottky structure as a function of annealing temperature

Palladium/Vanadium (Pd/V) Schottky structures are fabricated on n-type InP (100) and the electrical, structural and surface morphological characteristics have been studied at different annealing temperatures. The extracted barrier height of as-deposited Pd/V/n-InP Schottky diode is 0.59 eV (I-V) and 0.79 eV (C-V), respectively. However, the Schottky barrier height of the Pd/V Schottky contact slightly increases to 0.61 eV (I-V) and 0.84 eV (C-V) when the contact is annealed at 200 degrees C for 1 min. It is observed that the Schottky barrier height of the contact slightly decreases after annealing at 300, 400 and 500 degrees C for 1 min in N-2 atmosphere. From the above observations, it is clear that the electrical characteristics of Pd/V Schottky contacts improve after annealing at 200 degrees C. This indicates that the optimum annealing temperature for the Pd/V Schottky contact is 200 degrees C. Basing on the auger electron spectroscopy and X-ray diffraction results, the formation of Pd-In intermetallic compound at the interface may be the reason for the increase of barrier height upon annealing at 200 degrees C. The formation of phosphide phases at the Pd/V/n-InP interface could be the reason for the degradation in the barrier heights after annealing at 300, 400 and 500 degrees C. From the AFM results, it is evident that the overall surface morphology of the Pd/V Schottky contacts is fairly smooth. Copyright (c) 2011 John Wiley & Sons,