Properties of Indium Tin Oxide Films Grown on Microtextured Glass Substrates

Indium tin oxide (ITO) films were grown by radio frequency (RF) sputtering on plain and textured glass substrates that are kept at room temperature. Periodical texturing on the substrate surface was achieved through creation of cross-linked SU8 2000.5 negative tone photoresist structures by using the i-line 365 nm lithography process. Cross-linked SU8 2000.5 was highly transparent in the visible region. Optical and electrical properties of ITO films grown on both plain and textured glass substrates are measured and compared. ITO thin films coated on a periodically textured substrate showed higher transmittance when compared to ITO thin films coated on a plain substrate. The reason for the increase in the transmittance is attributed to multiple reflection induced due to the presence of side walls and edges of the periodic textures, leading to increased light path length near the ITO film surface and subsequent transmission reducing reflection. Electrical resistivity values measured on ITO films grown on plain and textured substrates revealed an increase in resistivity values of the films grown on textured substrates indicative of surface defects.