ZnO: In (IZO, 10wt % In2O3) and ZnO: Al (AZO, 1wt % Al2O3) films were deposited on Corning glass substrates by RF magnetron sputtering. The samples were either prepared on unheated substrates and post annealed in N2 at different temperatures, or prepared at elevated temperatures. Electrical, optical and structural properties were investigated as a function of deposition temperature and annealing temperature. Increasing the substrate heater temperature would lead to a decline in the electrical conductivity of IZO films, while AZO films showed unchanged performance in the substrate heater temperature range of 150 - 300°C. Post annealing appears to be an effective way to improve the electrical properties of both IZO and AZO films without sacrificing transparency. In this work, AZO films have higher conductivity and light transmission than IZO films.