Patterning of indium tin oxide by projection photoablation and lift-off process for fabrication of flat-panel displays

Abstract

Indium tin oxide (ITO), an important material used as a transparent conductive oxide in thin-film transistor liquid-crystal display fabrication, was patterned by a nonlithographic process. First, a Si3N4 substrate coated with photoresist was patterned by a projection photoablation process using 248nm wavelength KrF excimer laser radiation. ITO was then deposited by sputtering and patterned by lift-off. The resulting ITO pattern was clean even though it was patterned without the conventional steps of photoresist development and ITO etching. This process technology provides a faster and more economical patterning capability compared to conventional photolithography and etch processes used in the display industry.