Fabrication of high-transmittance ITO conducting films on PC substrates using multi-target sputtering

• Main Authors: Shui-Wen Li, 李水文
• Other Authors: 武東星
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/49333838303369269578

碩士 === 國立中興大學 === 材料科學與工程學系所 === 100 === In this study, the multi-target and dual-power (DC & RF) magnetron sputtering system was adopted to deposit anti-reflective films (SiO2 and TiO2) and transparent conducting film (indium-tin oxide, ITO) on polycarbonate substrates for touch plane applications. Before simulating the optical performance of this functional coating, the single-layer material such as SiO2, TiO2 and ITO was deposited on the Si substrates to acquire the corresponding reflectivity, absorptivity and refractive index data using an ellipseometer. The polycarbonate substrates were cleaned using O2 plasma before each coating process. The optical multilayer coatings were deposited with various process parameters such as sputtering power, substrate temperature and working pressure. The resistivity, transmittance, microstructure and mechanical characteristics of optical thin films were measured to evaluate the performance.In this work, the macromolecule polymer substrate (polycarbonate) with an endurance temperature of 100-130℃was used to replace the conventional glass substrate due to its lower cost. Since the ITO thin film has high transmittance (in the visible region) and low resistivity, the ITO thin film deposited on PC substrate can act as a potential structure for touch plane applications. Under optimum deposition conditions, where the working temperature, RF power, Ar and O2 flow rates were controlled on room temperature, 1.6 KW, 300 sccm and 2.2 sccm, respectively, the 20 nm ITO thin film with sheet resistivity of 300-600 Ω/□ and visible light transmittance of 88% was achieved. The successive ITO and anti-reflective coating process within the same multi-target and sputtering system, the transmittance of this functional coating can be improved to 91%. By integrating the cover glass, cover lens and adhesion glue, the developed functional multilayer (ITO with antireflection) shows high potential in touch panel applications.