Reactions of ultrathin hard amorphous carbon (a-C) films under microbeam laser processing

Abstract

The decomposition rate and mechanism of amorphous carbon (a-C) films under laser irradiation were analyzed. Graphitization saturated at early exposures of ∼4 min, while the composition progressed exponentially with the exposure time. It was found that the structure resistance to laser-induced changes increased with the sp s3/sp s2 bonding ratio in the a-C structure. The films sputtered at lower pressure showed higher degree of bonding ratio, higher degree of cross-linking between graphic domains and lower amount of interstitial and weakly bonded compositions. It was also found that reaction rate constant of carbon structure decreases with the bonding ratio in a-C structure.