Properties of amorphous carbon films characterized by laser desorption time of flight mass spectroscopy

Abstract Laser desorption time of flight mass spectroscopy was applied to measure carbon materials with various degrees of crystallinity. The threshold laser energy density ( E th ) to detect 12 C + systematically varied not only with the crystallinity of materials but also with light soaking and thermal annealing with respect to hydrogenated amorphous carbon (a-C:H). Since E th decreased by the light irradiation could be recovered by thermal annealing as was observed for hydrogenated amorphous silicon, we have verified for the first time a photo-degradation effect in a-C:H film.