This paper has relatively high technical standard and experimental skill. The fabrication of TCO film with hightransparency, low resistance and low chromaticity require exact control of several competing factors. This paper has resolvedthese problems reasonably well, thus recommended for publication. Indium tin oxide(ITO) thin films were by D.C. magnetronroll-to-roll sputter system utilizing ITO and SiO2 targets of ITO and SiO2. In this experiment, the effect of D.C. power, windingspeed, and oxygen flow rate on electrical and optical properties of ITO thin films were investigated from the view point ofsheet resistance, transmittance, and chromaticity(b*). The deposition of SiO2 was performed with RF power of 400W, Ar gasof 50sccm and the deposition of ITO, DC power of 600W, Ar gas of 50sccm, O2 gas of 0.2sccm, and winding speed of 0.56m/min. High quality ITO thin films without SiO2 layer had chromaticity of 2.87, sheet resistivity of 400ohm/square, and trans-mittance of 88% and SiO2-doped ITO Thin film with chromaticity of 2.01, sheet resistivity of 709ohm/square, and transmittanceof more than 90% were obtained. As a result, SiO2 was coated on PET before deposition of ITO, their chromaticity(b*) andtransmittance were better than previous results of ITO films. These results show that coating of SiO2 induced arisingchromaticity(b*) and transmittance. If the thickness of SiO2 is controlled, sheet resistance value of ITO film will be expected tobe better for touch screen. A four point probe and spectrophotometer are used to investigate the properties of ITO thin films.

Indium Tin Oxide (ITO) thin films on Polyethylene Terephtalate (PET) substrate were prepared by Roll-to-Roll sputter system with targets of 5 wt% and 10 wt% SnO2 at room temperature. The influence of the chromaticity (b*) and transmittance properties of the ITO Films were investigated. The ITO thin films were deposited as a function of the DC power, rolling speed, and Ar/O2 gas flow ratio, and then characterized by spectrophotometer. Their crystallinity and surface resistance were also analyzed by X-ray diffractometer and 4-point probe. As a result, the chromaticity (b*) and transmittance of the ITO films were broadly dependent on the thickness, which was controlled by the rolling speed. When the ITO films were prepared with the DC power of 300 W and the Ar/O2 gas flow ratio of 30/1 sccm using 10 wt% SnO2 target as a function of the rolling speeds 0.01 through 0.10 m/min, its chromaticity (b*) and transmittance were about -4.01 to 11.28 and 75.76 to 86.60%, respectively. In addition, when the ITO films were deposited with the DC power of 400W and the Ar/O2 gas flow ratio of 30/2 sccm used in 5 wt% SnO2 target, its chromaticity (b*) and transmittance were about -2.98 to 14.22 and 74.29 to 88.52%, respectively.

In this study, the stress-strain response and the cracking behaviors of ITO film on a PET substrate are investigated. The cracking behaviors of ITO thin films deposited on a thermoplastic semi-crystalline polymer developed for flexible display applications was investigated by means of tensile experiments equipped with an electrical measurement apparatus and an in-situ optical microscope. Electrical resistance increased gradually in the elastic-to-plastic transition region of the stress strain curves and cracks formed. Numerous cracks were found in this region, and the increase of the resistance was linked to the cracking of ITO thin films. Upon loading, the initial cracks perpendicular to the tensile axis were observed at about 1% of the total strain. They propagated to the entire sample width as the strain increased. The spacing between the horizontal cracks is thought to be determined by the fracture strength and the thickness of the ITO film as well as by the interfacial strength between the ITO and PET. The effect of the strain rate on the cracking behavior was also investigated. The crack density increased as the strain increased. The spacing between the horizontal cracks (perpendicular to the stress axis) increased as the strain rate decreased. The increase of the crack density as the strain rate decreased can be attributed to the higher fraction of the plastic strain to the total strain at a given total strain. The higher critical strain for the onset of the increase in the resistance and the crack initiation of the ITO/PET with a thinner ITO film (300 ohms/sq.) suggests a higher strength of the thinner ITO film.