Dependence of thermal annealing on the density distribution of interface states in Ti/n-GaAs(Te) Schottky diodes

The Ti/n-GaAs(Te) Schottky barrier diodes have been annealed in the tempera ture range 200-400 degrees C with steps of 100 degrees C for 5 min. The bar rier height value has increased with increasing annealing temperature. This increase has been attributed to that the annealing removes the passivation effect of the native oxide layer and reactivates the surface defects which are responsible for the Fermi level pinning. The value of equilibrium inte rface charge density Q(ss)(0) has increased with increasing annealing tempe rature. It has been found that the experimental density distribution curves of the interface states and the values of equilibrium interface charge den sity Q(ss)(0) has confirmed this interpretation. The results indicate that the negative equilibrium interface charge is responsible for the actual equ ilibrium barrier height value. (C) 1999 Elsevier Science B.V. All rights re served.