CURRENT-VOLTAGE CHARACTERISTICS OF THERMALLY ANNEALED Ni/n-GaAs SCHOTTKY CONTACTS

Abstract

The Schottky barrier type Ni/n-GaAs contacts fabricated by us were thermally annealed at 600 degrees C and 700 degrees C for 1 min. The apparent barrier height Phi(ap) and ideality factor of the diodes were calculated from the forward bias current-voltage characteristic in 60-320 K range. The Phi(ap) values for the nonannealed and 600 degrees C and 700 degrees C annealed diodes were obtained as 0.80, 0.81 and 0.67 eV at 300 K, respectively. Thus, it has been concluded that the reduced barrier due to the thermal annealing at 700 degrees C promises some device applications. The current preferentially flows through the lowest barrier height (BH) with the temperature due to the BH inhomogeneities. Therefore, it was seen that the Phi(ap) versus (2kT)(-1) plots for the nonannealed and annealed diodes showed the linear behavior according to Gaussian distributions.