STRUCTURE AND PHOTO- FUNCTIONAL PROPERTIES OF TiO2 THIN FILM PREPARED BY RF HELICON MAGNETRON SPUTTERING

Abstract

Fabrication of titanium dioxide (TiO₂) thin film (200nm) has been done by using RF helicon magnetron sputtering from metallic Ti target under changing of O₂ flow rate and substrate temperature. Film structure was measured by X-ray diffraction (XRD). The films were examined by an X-ray photoelectron spectroscopy (XPS) to study the structure; atomic force microscopy (AFM) and field-emission scanning electron microscope (FE-SEM) were employed to investigate the surface morphology and the cross section of films, respectively. Optical properties and optical band gap were calculated by using UV-VIS spectrophotometer. Photocatalytic activity was evaluated by light induced degradation of methylene blue (MB) solution using UV and Vis light. TiO₂ thin film with a rutile phase at substrate temperature 100^oC and O₂ flow rate to 0.5 - 1.0sccm can be obtained, also an anatase phase can be fabricated when set substrate temperature to 300 ^oC and O₂ flow rate to 2.5sccm. Obtained films showed a high dense with smooth surface and high crystalline. Maximum degradation rate (about 85%) of MB has been indicated at anatase phase under UV light irradiation, while under Vis light irradiation rutile and anatase mixture phase showed a maximum degradation rate (about 15%).

In this work, the morphological, structural, optical, and photocatalytic properties of TiO₂ thin films that were fabricated by RF helicon magnetron sputtering under change of O₂ flow rate and substrate temperature have been investigated. It is expected that the change of substrate temperature and/or O₂ flow rate will make ability to control the film structure.