PROPERTIES OF AMORPHOUS-CARBON FILMS CHARACTERIZED BY LASER-DESORPTION TIME-OF-FLIGHT MASS-SPECTROSCOPY

Laser desorption time of flight mass spectroscopy was applied to measu re carbon materials with various degrees of crystallinity. The thresho ld laser energy density (E-th) to detect C-12(+) systematically varied not only with the crystallinity of materials but also with light soak ing and thermal annealing with respect to hydrogenated amorphous carbo n (a-C:H). Since E-th decreased by the light irradiation could be reco vered by thermal annealing as was observed for hydrogenated amorphous silicon, we have verified for the first time a photo-degradation effec t in a-C:H film. (C) 1998 Elsevier Science B.V. All rights reserved.