Characterization of diamond-like carbon films formed by magnetically enhanced plasma chemical vapor deposition

Diamond-like carbon (DLC) films were formed at high deposition rates on various substrates such as silicon wafers, metal-evaporated magnetic (ME) tape and polyethylene terephthalate (PET) film by magnetically enhanced plasma chemical vapor deposition. The film deposition was carried out on a running plastic film by discharge decomposition of C2H4 and C2H2 using a roll coater. The maximum dynamic deposition rate was 750 nm m/min at a magnetic field intensity of approximately 2.4×104 A/m using C2H2 gas. The films were hard with a micro-Vickers hardness of 2000. The coefficient of kinetic friction of the films deposited on the ME tape was 0.06–0.09, which was smaller than that of an uncoated one, 0.15. Results from scratch tests on the above films showed excellent durability in comparison with those for undeposited tapes. Moreover, DLC film deposited PET film showed a good gas barrier characteristic, that is, its oxygen transmission rate was 0.4 cm3/m2 day atm.