The structural, electrical and moisture resistance properties of Ga-doped ZnO (GZO) films with 200 nm thickness in terms of their dependence on oxygen gas flow rate (fO(2)) during deposition were studied. GZO films are deposited on glass substrates by ion plating with DC arc discharge. After a reliability test at a temperature of 60 degrees C and a relative humidity of 95% for 500 h, the percentage of resistivity change of GZO films decreased from 16-20% to 3-11% with increasing fO(2) from 6-12 to 14-25 sccm. The minimum percentage of the resistivity change was observed in the GZO films deposited at fO(2) of 21 sccm and the resistivity after the reliability test was 3.5x10(-4) Omega cm. The effects of the intrinsic defects on the percentage of resistivity change are discussed on the basis of electrical and optical characteristics of GZO films. (C) 2011 Elsevier B.V. All rights reserved.