Micro-patterning of TiO2 thin films by photovoltaic effect on silicon substrates

In this letter, micro-patterned TiO2 thin films were prepared on the Si wafer substrates by photogenerated carriers without using photoresist or self-assembled monolayers. The TiO2 particles deposited onto the unirradiated regions. The different trapping/detrapping dynamics of the electrons and holes cause the change of surface potential in the irradiated regions, thus patterned TiO2 thin films formed by the photovoltaic effect. The thickness of the TiO2 patterns is about 80 nm and the film is anatase after annealed at 500 °C. This method is applied to get ZrO2 patterns on Si substrate.