Structure and Morphology Evolution of TiO2 Films Grown by Sputtering

The structure and morphology evolution of TiO₂ thin films deposited by RF magnetron sputtering on Si(100), glass and steel substrates at various deposition conditions was investigated. The effect of total pressure (P_t), O₂/Ar flow and Au-Pd buffer layer on the structure and morphology of TiO₂ film has been studied thoroughly. It was found that the rutile phase crystallinity increased with decrease in P_t and increase in O₂ flow. Here we also show by sputtering it is possible to grow rutile core and anatase shell heterostructure TiO₂ nanorods of length 500-700 nm and diameter 40-100 nm on gold coated Si (Au/Si) substrate without external heating. Also, TiO₂ whiskers of length 0.9-30 μm and diameter 0.66-1.2 μm were grown on Au-Pd/Si substrates when substrate temperature was maintained at 450-500°C. The presented results suggests that the process parameters (such as: P_t, Ar/O₂ flow, Au-Pd layer on Si) define the structure and morphology of TiO₂ during magnetron sputtering.