Effect of VUV exposures to the hydrogenated diamond-like carbon films

Yokota, Kumiko*; Tagawa, Masahito*; Furuyama, Yuichi*; Kanda, Kazuhiro*; Tode, Mayumi; Yoshigoe, Akitaka ; Teraoka, Yuden

In this study, hydrogen desorption from highly-hydrogenated diamond-like-carbon (DLC) containing 54% hydrogen via vacuum ultraviolet light irradiation was investigated and compared to that of soft X-ray irradiation. An elastic recoil detection analysis (ERDA) spectrum showed the decrease of hydrogen up to 0.5 micrometer depth with increasing the dose of vacuum ultraviolet light. On the other hand, an ERDA spectrum for the soft X-ray irradiation revealed that the decrease of hydrogen from a whole depth, that is, hydrogen desorption reactions took place remarkably comparing to the vacuum ultraviolet light irradiation. In both cases, the thickness of DLC film did not change at all. These facts showed that a depth profile of hydrogen desorption via light excitation depended considerably on wavelength.