Gallium-doped zinc oxide (ZnO:Ga = 97:3 wt%, GZO) transparent conducting films have been deposited on glass substrates (Corning 1737F), with and without ZnO buffer layers by radio-frequency (r.f.) magnetron sputtering. The effect of ZnO buffer layer deposition parameters on electrical, structural, morphological and optical properties of GZO films (GZO/ZnO/glass) was investigated. The optimization of coating process parameters (r.f. power, sputtering pressure, thickness, annealing) on ZnO buffer layer with multiple qualities based on the orthogonal array has been studied. The electrical resistivity and the average transmittance of the GZO/ZnO/glass films were improved by annealing in vacuum ambient of the ZnO buffer layer. Findings based on the grey relational analysis show that the lowest electrical resistivity of GZO/ZnO/glass films to be about 9.45 x 10(-4) Omega m, and visible range transmittance about 85%. (c) 2007 Elsevier B.V. All rights reserved.