Several metal contacts (Au, Ag, Pt, Pd, Cu, Ni, Ge, Ti, Cr, and Al) were tested on Metalorganic vapour phase epitaxy (MOVPE)-grown InN. Current-voltage (I-V) measurements were carried out. Most of the metals showed ohmic behavior. Pt and Ge yielded some Schottky contact behavior, but were very unstable. Al formed a stable rectifying contact after thermal annealing over 500°C. Several annealing temperatures and times were studied. The rectifying behavior is explained in terms of N atoms reacting with In and Al to form a layer of AlInN, which has a larger band gap than InN. 10.1143/JJAP.45.36 ©2006 The Japan Society of Applied Physics.