High performance solution-deposited bilayer channel indium-zinc-oxide thin film transistors by low-temperature microwave annealing

摘要

We report the high-performance solution-deposited indium zinc-oxide (IZO) TFTs with a bilayer channel structure fabricated at low temperature using a microwave irradiation (MWI) post-deposition annealing (PDA) process. Although, the MWI process temperature (89 degrees C) was much lower than the baking temperature (180 degrees C) of solution precursors, the microwave irradiated film has comparable chemical binding states to the thermal annealed film at 600 degrees C. For the enhancement of channel performance, channel engineering was applied by exploiting bilayer channel with different composition-ratios of In and Zn (In:Zn = 3:1, 2:1, 1:1, 1:2 and 1:3). Bilayer channel IZO TFTs consist of electron transfer channel layer and capping layer. The electrical characteristics for various combinations of bilayer channel were investigated. As a result, the transfer channel layer of In:Zn = 1:1 and the capping layer of In:Zn = 3:1 turned out to be effective for improving the mobility, subthreshold swing and hysteresis of IZO TFTs. We found that the electrical characteristics of solution-deposited IZO TFTs can be greatly improved by using bilayer channel structure and low temperature MWI-PDA process. (C) 2015 Elsevier B.V. All rights reserved.