Investigation on Ag/Ti Ohmic Contacts to Si-Doped n-Type Al0.27Ga0.73N and the Effect of Post Annealing Treatments
In this study, we investigated the contact characteristics of bi-layer thin films, Ag (200nm)/Ti (100nm) on Si-doped n-type Al0.27Ga0.73N film grown on sapphire substrate. The contacts were annealed at different temperatures (400°C-800°C) for 10 min in N2 ambient. The effects of cryogenic cooling immediately after heat treatment for improving ohmic behavior (I-V linearity) of the samples were reported. Specific contact resistivity, ρc, was determined using transmission line method (TLM) via current-voltage (I-V) measurements. Scanning electron microscopy (SEM) measurements were carried out on the as-deposited, annealed (N), and annealed-and-cryogenically (N+C) treated contacts where the surface morphology of each of these conditions were compared. In addition, measurement of the samples by atomic force microscopy (AFM) was taken in order to characterize the surface morphology.
A.K. Arof and S.A. Hashim Ali
S. Othman et al., "Investigation on Ag/Ti Ohmic Contacts to Si-Doped n-Type Al0.27Ga0.73N and the Effect of Post Annealing Treatments", Materials Science Forum, Vol. 517, pp. 281-286, 2006