Surface morphological, electrical and transport properties of rapidly annealed double layers Ru/Cr Schottky structure on n-type InP

The electrical and transport properties of a fabricated bilayer Ru/Cr/n-InP Schottky diode (SD) have been investigated at different annealing temperatures. Atomic force microscopy results have showed that the overall surface morphology of the Ru/Cr/n-InP SD is fairly smooth at elevated temperatures. High barrier height is achieved for the diode annealed at 300 °C compared to the as-deposited, annealed at 200 and 400 °C diodes. The series resistance and shunt resistance of the Ru/Cr/n-InP SD are estimated by current–voltage method at different annealing temperatures. The barrier heights and series resistance are also determined by Cheung’s and modified Norde functions. The interface state density of the Ru/Cr/n-InP SD is found to be decreased after annealing at 300 °C and then slightly increased upon annealing at 400 °C. The difference between barrier heights obtained from current–voltage and capacitance–voltage is also discussed. Experimental results have showed that the Poole–Frenkel emission is found to be dominant in the lower bias region whereas Schottky emission is dominant in the higher bias region for the Ru/Cr/n-InP SDs irrespective of annealing temperatures.