Thin Films formed by Radiofrequency Sputtering of β-tricalcium Phosphate

Purpose: The purpose of this study was to evaluate the feasibility of formation of thin film coatings of bioactive ceramics, such as β-tricalcium phosphate (β-TCP), by radio frequency (RF) sputtering. In this paper, we report the results of our preliminary attempts, as a trial of this concept, to use radio frequency sputtering for obtaining thin film coatings of a ceramic substance on a quartz glass substrate.Methods: We attempted to obtain a thin film coating of β-TCP on a quartz glass surface using an RF sputtering deposition system (L-332S-5FHS, ANELVA, Japan). We examined the thickness of the films deposited on the quartz glass substrate with a confocal laser scanning microscope and characterized the films by electron probe microanalysis (EPMA), scanning electron microscopy (SEM), X ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis.Results: The films were found to be about 0.51 μm in thickness. Although our attempt was directed at obtaining a β-TCP coating on the quartz glass surface, the resultant film consisted of Ca and P in the ratio of 3:1, and was almost amorphous. However, the Ca and P were uniformly distributed on the surface of the films, confirming the feasibility of using an RF sputtering system to obtain a homogeneous film coating.Conclusion: Our results suggest that RF sputtering may be a feasible technique for the preparation of ceramic coatings.