RF-magnetron sputtering technique for producing hydroxyapatite coating film on various substrates.

A sputtering technique is an effective method for surface modification of materials, but there are many complex process parameters to influence on the physical and chemical properties of the sputtered coating films. In this paper the process parameters were investigated when the hydroxyapatite (HA) was coated onto various substrates including titanium (Ti), alumina ceramic (Al(2)O(3)) and stainless steel (SUS) plates under various sputtering conditions, target type, Ar gas pressure, and discharge power. The deposition rate of HA was much higher in a solid plate target than in a powder lump target owing to the difference of apparent density 75%, 18%, respectively. Ar gas pressure little influenced on the deposition rate. The HA coating thickness increased in proportion with discharge power. After hydrothermal treatment the thickness of HA slightly decreased, on the other hands Ca/P ratio slightly raised. The surface of the HA coating was smooth, homogeneous and dense.