Low-Temperature Solution-Based In2O3 Channel Formation for Thin-Film Transistors Using a Visible Laser-Assisted Combustion Process

This letter reports the low-temperature solution-based fabrication of indium oxide (In
₂
O
₃
) thin-film transistors (TFTs) using a visible laser-assisted urea combustion process. An In
₂
O
₃
precursor solution containing a small amount of urea absorbed the photon energy from a blue laser and started the combustion of urea to form a crystallized In
₂
O
₃
phase. Atomic force microscopy and X-ray diffraction showed that both laser radiation and urea combustion together are necessary to convert a dried precursor solution layer to a crystallized In
₂
O
₃
phase. A TFT fabricated from the 0.2-mol% urea-added solution and laser annealed with a 250-J/cm
²
energy fluence exhibited superior transfer characteristics compared with the TFTs fabricated either without urea addition or with small energy fluence radiation. Based on these results and considering the price of blue laser diodes, this technique can be an economical solution for the fabrication of oxide semiconductor TFTs on flexible substrates with a low melting point.