Top-down contact lithography fabrication of a TiO2 nanowire array over a SiO2 mesa

A fast and cheap nanofabrication process for a titania (TiO2) nanostructured nanowire array with a lateral section ranging from 90 to 180 nm and 1.4 mm in length is presented. As an alternative to typical pattern transfer techniques for submicron fabrication, this work focused on a standard 365 nm ultraviolet (UV) photolithographic process that is able to fabricate sol-gel nanostructured titania nanowires from a solid thin film onto a silicon oxide mesa. Useful process parameters like anisotropy and bias have been calculated. Finally, in order to carry out electrical characterization, the TiO2 nanowire-based array was electrically contacted by platinum electrodes and tested with EtOH pulses to validate enhanced gas sensor device performance and to verify electrical conductivity of these nanostructures.