The effect of thermal treatment on the characteristic parameters of Ni/-, Ti/- and NiTi alloy n-GaAs Schottky diodes

Ni/-, Ti/- and NiTi alloy/n-GaAs Schottky barrier diodes (SBDs) have been f abricated and annealed for 5 min in the temperature range of 100-650 degree s C with steps of 50 or 100 degrees C. The value of Phi(b) and n for as-dep osited Ni/-, Ti/- and NiTi alloy/n-GaAs SBDs has been determined to be 0.73 , 0.64 and 0.68 eV and 1.02, 1.08 and 1.10, respectively. For the NiTi allo y/n-GaAs diode, while the ideality factor remains unchanged up to 400 degre es C annealing, it decreased to 1.02 at 500 degrees C. An additional barrie r height enhancement with increased annealing temperature occurs while the ideality factor remains close to unity. Thermal stability of the NiTi alloy /n-GaAs diode is maintained up to an annealing temperature of 500 degrees C . It has been concluded that the NiTi alloy/n-GaAs SBD contact has a better performance than the Ni/- and Ti/n-type. (C) 1999 Elsevier Science Ltd. Al l rights reserved.