[8a-PA1-1~17] 6.2 Carbon-based thin films

[8a-PA1-11] Modification process of fluorinated DLC film by the irradiation of soft X-rays

〇Kazuhiro Kanda¹, Hiroki Takamatsu¹, Eri Miura-Fujisawa², Hiroki Akasaka³, Akihiro Saiga⁴, Koji Tamada⁴ (1.LASTI, Univ. Hyogo, 2.School Eng., Univ. Hyogo., 3.Tokyo Inst. Tech., 4.Tokyo College)

Keywords:Diamond-like Carbon thin film, Soft X-ray, Irradiation effect

The effect of soft X-ray irradiation on fluorinated diamond-like carbon (F-DLC) films was investigated using synchrotron radiation (SR). The Vickers hardness of the F-DLC films substantially increased from an initial value of »290 HV to »800 HV at a dose of 50 mA×h, the remained constant at »1100 HV at doses of more than 300 mA×h. This dose dependence was consistent with those of the film thickness, elemental composition, and sp²/(sp²+sp³) ratio of carbon in the film. A depth profile of the elemental composition inside each F-DLC film obtained by measurement of the X-ray photoelectron spectrum (XPS) during sputtering showed that the composition ratio of fluorine was approximately constant from the surface to the neighborhood of the substrate. Namely, fluorine atoms were desorbed by the SR irradiation from not only the surface but also the substrate neighborhood. Modification by the SR irradiation was found to occur in the entire F-DLC film of thickness »200 nm.