Effects of bias voltage on the properties of ITO films prepared on polymer substrates

The ITO (indium tin oxide) thin films were deposited on acryl, glass, PET, and poly-carbonate substrates by DC reactive magnetron sputtering. The bias voltage was changed from −20 to −80 V. As the bias voltage increased, the deposition rate of ITO films decreased regardless of substrate types. The roughness of the films on PET increased with the bias voltage. The study demonstrated that the bias improved the electrical and optical properties of ITO films regardless of substrate types. The lowest electrical resistivity of 5.5×10−4 Ω-cm and visible transmittance of about 80% were achieved by applying a negative bias of −60 V.