Process Optimization of Aluminum-Doped Zinc Oxide Films by In-Line Pulsed-DC Sputtering and Its Application to Resistive Touch Panels

Abstract

To process transparent conductive oxide (TCO) layers in the fabrication of electronic devices economically, aluminum-doped zinc oxide (AZO) was optimized by in-line pulsed-DC magnetron sputtering with various pulse duty ratios and oxygen gas ratios to obtain a relatively high conductivity and high transparency in the range of visible light. The optimized AZO films were applied to the fabrication of an analog resistive-type touch panel instead of ITO. The optimized AZO showed a sheet resistance of about 600 Omega/square and the transmittance was above 83%. Also, a 3.5-in. diagonal-sized resistive touch panel composed of AZO deposited glass and polyethylene terephthalate (PET) was obtained. The operable AZO touch panel showed similar transmittance to an ITO touch panel and good linearity characteristics.