Effects of annealing on Ti Schottky barriers on n-type GaN

Abstract
The authors investigate the Schottky barrier heights of Ti films deposited on n-type GaN. The effective barrier height Φb0 is measured by current-voltage measurements against temperature. An increasing barrier height Φb0 from ~200 meV (as-deposited) to 250 meV after annealing at temperatures as low as 60°C is observed. After annealing at 230°C and above, a stable Φb0 of 450 meV is measured. The increase in Φb0 is not due to any macroscopic interfacial reaction.