Properties of Indium Tin Oxide Thin Films Deposited on Glass and Clay Substrates by Ion-Beam Sputter Deposition Method

Abstract

Indium tin oxide (ITO) thin films were prepared on glass and clay substrates by ion beam sputter deposition method. The surface morphologies of ITO films showed that the ITO film on glass substrate is smooth; in contrast, the ITO film on clay substrate is rough. The X-ray diffraction patterns showed two different orientations, i.e., (400) and (222) on different substrates, i.e., glass and clay, respectively. The optical spectra showed that the optical transmittance of ITO/glass is greater than that of ITO/clay substrate; it is due to the difference in substrate surface roughness between ITO/glass and ITO/clay. The sheet resistances of ITO/glass and ITO/clay were calculated as 32 and 41 Ω/□, respectively. The increase in film thickness enhances the growth of the films along (222) direction. It is attributed that the stress relaxation is one of the reasons for the change of preferred orientation from (444) to (222) plane. In this paper we discuss the possible factors which determine the crystal growth and orientation of ITO thin films.