Surface modification of ceramics is required to protect from metallic contamination by using knives and forks and to keep a water repellent nature.[1] Partly, zirconium oxide (ZrO₂) thin films are used for the demands and have been prepared from zirconium oxychloride octahydrate using a sol-gel method[1]. However, this method has disadvantageous to efficient preparation due to process time. Strong-acid property of the solution is also another problem. From these points, we have proposed dry process using radio frequency (RF) inductively coupled plasma (ICP) sputtering. This is expected to improve working conditions and is also to be cost-effective method for ZrO₂ thin film preparation. Our previous works[2] resulted that this dry process using oxygen RF plasma sputtering was certified to modify effectively the surface state of the ceramics. This was because the stoichiometric ZrO₂ film was prepared in a state of amorphous and the water contact angle of the prepared film was similar to that of the existing sol-gel method. On the other hand, the water contact angle of the film increased up to about 90 degree with the time after the substrate was taken out of the chamber. The water contact angles were found to tend to increase with oxidation of the target. Influences of the surface state of the sputtering target on the water contact angle of ZrO₂ thin film have been investigated by X-ray photo spectroscopy analysis.

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