Solution-Free UV-Based Direct Surface Modification of Oxide Films for Self-Patterned Metal-Oxide Thin-Film Transistors

초록

In thin-film device fabrication, particularly using a solution process, self-patterning is effective in reducing the fabrication steps by eliminating the conventional photolithography process. Here, solution-free ultraviolet (UV)-based direct surface modification is introduced for self-patterning of solution-processed oxide semiconductors. The direct surface modification is carried out by selectively irradiating UV light on a SiO2 film, creating regions with different surface energies. This surface energy difference induces different wetting behaviors of spin-coated indium-gallium-zinc-oxide (IGZO) precursor film, enabling the direct self-patterning. By optimizing the surface modification conditions and the channel design, self-patterned IGZO thin-film transistors (TFTs) are successfully fabricated. The self-patterned IGZO TFTs exhibit low off-state current (<10(-12) A), high on/off ratio (approximate to 10(8)), and low gate-leakage level without using any channel etching process. The results show that the direct surface modification can be a good candidate for realizing self-patterned IGZO TFTs.

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