An electrical method to characterize thermal reactions of Pd/GaAs and Ni/GaAs contacts

Capacitance-voltage (C-V) and current-voltage (I-V) measurements were used to study the thermal reaction of Pd/GaAs contacts and Ni/GaAs contacts. The thickness of GaAs consumed by the metal/GaAs reaction during annealing was calculated from C-V analyses and I-V analyses. For annealing temperatures below 350°C, the Schottky characteristics of the diodes were good but the electrical junction moves into the GaAs after annealing. The amount of junction movement was calculated directly from our measurements. The diffusion coefficients of Pd and Ni in GaAs at 300°C were estimated both to be around 1.2 × 1014 cm2/s.