Effect of SiO2and Nb2O5Buffer Layer on Optical Characteristics of ITO Thin Film

Abstract

This paper presents the results of the optical characteristics of ITO thin film with different buffer layer thicknesses of <TEX>$SiO_2$</TEX> and <TEX>$Nb_2O_5$</TEX> for touch sensor application. <TEX>$SiO_2$</TEX> and <TEX>$Nb_2O_5$</TEX> buffer layers were deposited using RF magnetron sputtering equipment. The buffer layers were inserted between glass and ITO layers. In order to compare with the experimental results, the Essential Macleod Program (EMP) was adopted. Based on EMP simulation, the [<TEX>$Nb_2O_5{\mid}SiO_2{\mid}ITO$</TEX>] multi-layered thin film exhibited high transmittance of more than 85% in the visible region. The actual experimental results also showed transmittance of more than 85% in the visible region, indicating that the simulated results were well matched with the experimental results. The sheet resistance of ITO based film was about <TEX>$340{\Omega}/sq$</TEX>. The surface roughness maintained a relatively small value within the range of 0.1~0.4 nm when using the <TEX>$Nb_2O_5$</TEX> and <TEX>$SiO_2$</TEX> buffer layers.