The zinc doped indium oxide (IZO) films deposited with various sputter parameters such as, film thickness ranging from 200 to 500 nm, O-2/Ar ratio ranging from 0% to 12%, and sputter power ranging from 100 to 250 W was studied in this work. For a 200 nm thick IZO film grown at room temperature in pure argon atmosphere, the resistivity was 2.4 x 10(-4) Omega cm and the average transmittance in the visible region was 80%. The root mean square roughness of IZO film was around 0.4 nm regardless of the film thickness due to the IZO films exhibiting an amorphous structure. With increasing film thickness, the IZO films showed an increase in the resistivity and energy band gap. X-ray photoelectron spectroscopy analysis suggests that the IZO films with reduction of O-2/Ar ratio possess two splitting O 1s binding energy levels, suggesting the IZO films were oxygen deficient and resulted in a lower resistivity. (c) 2005 American Vacuum Society.