Study on wet patterning of thin films in vertical-transfer wet station for thin-film-transistor manufacturing

Abstract

To overcome the "pseudo-puddling effect" in a low-angle-tilt transfer system with an oversized glass substrate over 2 m, a vertical transfer is suggested. The aim of the present work is to study the wet-etching behavior of an aluminum/molybdenum double layer deposited on the glass substrate in a vertical transfer wet etching system and compare it with a typical 5 degrees-tilt-transfer system. Compared with the tilt-transfer wet station, the vertical etching system has three advantages, namely, 50% space savings, higher throughput due to the high etch rate, and good etch uniformity over the entire glass for thin-film-transistor application. The computational fluid-dynamics analysis is used to predict the change of the etch uniformity as a function of the tilt angle of the glass substrate.