Single crystalline undoped and Ga-doped n-type zinc oxide (ZnO) films were grown on sapphire (Al(2)O(3)) substrates by inductively coupled plasma (ICP) metal organic chemical vapor deposition. Effects of growth variables on the structural, optical, and electrical properties of ZnO films have been studied in detail. Single crystal films with flat and smooth surfaces were reproducibly obtained, with application of sample bias and O(2) ICP. The best film properties were obtained at the growth condition of 650 degrees C, 400 W ICP power, -94 V bias voltage, O/Zn (VI/II) ratio of 75. Single crystalline Ga doped n-ZnO films were also obtained, with free carrier concentration of about 1.5 x 10(19)/cm(3) at 1 at.% Ga concentration. (C) 2009 Elsevier B.V. All rights reserved.