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 °C for 1 min. It is observed that the Schottky barrier height of the contact slightly decreases after annealing at 300, 400 and 500 °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 °C. This indicates that the optimum annealing temperature for the Pd/V Schottky contact is 200 °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 °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 °C. From the AFM results, it is evident that the overall surface morphology of the Pd/V Schottky contacts is fairly smooth.