Amongst the most widely employed thin films in Flat Panel Displays (FPDs) belong to the described as Transparent Conducting Oxide (TCO) materials. When the thin films were applied for devices, etching characteristics is important process factor due to availability of patterning is directly linked with productivity. The TCO materials should have to proper etching characteristics for transparent electrode¹. By far the most common industrially employed TCO is Indium Tin Oxide (ITO), which is more correctly described as Sn-doped In₂O₃. An n-type semiconductor, it offers an optimum performance in terms of conductivity and transparency. In order to utilize properties of thin films such as ITO it is usually necessary to pattern them to create functional structures. The conventional method for patterning is to use wet chemical etch process. Such techniques require multiple process stages, large expensive machinery, small-geometry patterning².

In this study, the relationship between patterning characteristics and other characteristics which depend on etch conditions, especially the RF power, the DC bias voltage, the process pressure, was investigated in ITO films etched by the inductively coupled plasma (ICP) system³. The analysis of x-ray photoelectron spectroscopy (XPS) was carried out to investigate the chemical reactions between the surfaces of ITO thin films and etch species.

¹Z. Wang, S. Naka, H. Okada, Thin Solid Films, 518 (2009) 497.

²C.J. Huang, Y.K. Su, S.L. Wu, Materials Chemistry and Physics 84 (2004) 146.

³J.C. Woo, D.S. Um, C.I. Kim, Thin Solid Films 518 (2010) 2905