Effect of substrate feature on surface morphologies and properties of ITO films deposited by RF magnetron sputtering

Abstract

ITO films were deposited on c-Si wafer, and two glass substrates by RF magnetron sputtering at constant RF power, and substrate temperature of 60 W, and 450°C respectively. The surface morphologies of the substrates were analyzed before and after film depositions by AFM measurements. The crystalline structural, electrical, and optical properties were analyzed after film depositions by XRD, Hall measurement, and UV-Vis spectrophotometer respectively. It was found that, with lower surface roughness, the deposited ITO films showed significant larger domain-grain structure, lower surface roughness, and higher (400) preferred orientation than that deposited on the substrate with higher surface roughness, with the transmittances of higher than 80% for both substrates. From the structural, and electrical properties, it implied that, with higher surface roughness, the carrier concentrations was contributed mainly from the Sn substitution, whereas it was dominant from the oxygen deficiency for the lower surface roughness substrate. The deposited ITO film with lower resistivity and high transmittance can be achieved for the films deposited on lower substrate surface roughness.