The electrical properties of Cr/Pt/Au and Ni/Au ohmic contacts with unintentionally doped In2O3 (U-In2O3) film and zinc-doped In2O3 (In2O3:Zn) prepared by reactive magnetron sputtering deposition are described. The lowest specific contact resistance of Cr/Pt/ An and Ni/Au is 2.94 x 10(-6) and 1.49 x 10(-2) Omega-cm(2), respectively, as determined by the transmission line model (TLM) after heat treatment at 300 degrees C by thermal annealing for 10 min in nitrogen ambient. The indium oxide diodes have an ideality factor of 1.1 and a soft breakdown voltage of 5 V. The reverse leakage current prior to breakdown is around 10(-5) A. (c) 2006 Elsevier Ltd. All rights reserved.