[17a-Z15-1~7] 6.2 Carbon-based thin films

[17a-Z15-1] Change of free volume in hydrogenated DLC film by the irradiation of soft X-rays

〇Kazuhiro Kanda¹, Tatsuya Tamura¹, Hiroki Akasaka², Fuminobu Hori³, Atsushi Yabuuchi⁴, Atsushi Kinomura⁴ (1.LASTI, Univ. Hyogo, 2.Tokyo Inst. Tech., 3.Eng., Osaka Pref. Univ., 4.KURNS, Kyoto Univ.)

Keywords:amorphous carbon film, Positron Annihilation Spectroscopy, soft X-ray irradiation

Measurements of positron annihilation spectroscopy were carried out using a slow positron beam to investigate how the free volume in the hydrogenated DLC film changes with soft X-ray irradiation. The positron lifetime increased with increasing soft X-ray dose, indicating an increase in the free volume in the film. On the other hand, the S parameter decreased, indicating an increase in the free electron density in the voids. This may be attributed to the change in the elemental composition around the voids due to the desorption of hydrogen by soft X-ray irradiation.