Employment of rapid thermal annealing for solution-processed InGaZnO thin film transistors

We employed rapid thermal annealing (RTA) as a novel approach to anneal indium–gallium–zinc–oxide films for thin film transistor (TFT) applications. We analyzed the binding states of the elements presented in the films annealed with RTA and hot plate based on X-ray photoelectron spectroscopy data. The investigation confirmed that the RTA samples underwent sol–gel reactions at a low temperature of 180 °C. We also acquired the transfer curves of the TFTs incorporated with the samples. The RTA samples exhibited a high on-current level, whereas the hot plate sample annealed at the same temperature demonstrated nearly no current flow. The data manifested that RTA generated both photonic and thermal energies, thus efficiently facilitating sol–gel reactions at a low temperature. Furthermore, we investigated on the energy band structures of the annealed films based on reflection electron energy loss spectroscopy and ultraviolet photoelectron spectroscopy analyses, discovering that the annealing atmosphere significantly affected the band structure of the film.