In this paper we present results of indium zinc oxide deposited at room temperature by rf magnetron sputtering, with an electron mobility as high as 60 cm(2)/Vs. The films present a resistivity as low as 5 x 10(-4) Omega cm, with an optical transmittance of 85%. The structure of these films seems to be polymorphous (mix of different amorphous and nanocrystalline phases from different origins) as detected from XRD patterns with a smooth surface and from SEM micrographs, is highly important to ensure a long lifetime when used in display devices. (c) 2005 Elsevier B.V. All rights reserved.