Fabrication of oxide TFTs with Al2O3/ZnO gate stacks patterned using a dry etching method

In this paper, we describe a newly developed dry etching process for the fabrication of ZnO-based oxide thin-film transistors (TFTs). The dry etching behavior of ZnO and Al2O3 thin films was systematically investigated by varying the etching gas mixtures and their mixing ratios in a dry etching system using high-density helicon plasma. We fabricated an oxide TFT using an Al2O3/ZnO gate stack patterned by dry etching and confirmed good device characteristics, in which the field effect mobility and the ratio of on/off drain currents were about 0.8 cm(2)/(V s) and 10(7), respectively. (c) 2007 The Electrochemical Society.