Fabrication of polycrystalline TiO2 nanopatterns by TiO2 sol base imprint lithography

This paper reports a process for fabricating TiO2 nano-patterns using nanoimprint lithography and a sol–gel method. An ethanol-based TiO2 sol was prepared using tetrabutylorthotitanate as a precursor and used as an imprint resin. A replicated polydimethylsiloxane (PDMS) mold was used as an imprint stamp. During the imprinting process at 5 atm and 200 °C for 1 h, the TiO2 sol changed to a TiO2 gel by absorbing the solvent into the PDMS mold. After imprinting, a TiO2 gel pattern was formed on an oxidized Si wafer. After subsequent annealing, it confirmed that patterns of the master template were transferred to TiO2 patterns by Scanning Electron Microscopy. Furthermore, Transmission Electron Microscopy and X-Ray Diffraction showed that the TiO2 gel patterns had been converted to an inorganic polycrystalline TiO2 pattern.