Corrosion Resistance of Diamond-like Carbon-Coated Aluminum Films

摘要

The corrosion characteristics of diamond-like carbon (DLC) films, deposited on aluminum film-covered single-crystal silicon substrates were investigated using standard potentiometric methods. The DLC films were deposited by radio frequency (13.56 MHZ) plasma deposition from three different precursors, methane, acetylene, and 1,3 butadiene, with argon or hydrogen as the diluent. A 5 nm thick polysilicon (PS) film was plasma-deposited prior to DLC film deposition to improve adhesion. The measured corrosion current increased with an increase in the hydrogen content in the feed gas mixture and was lowest for the films deposited from butadiene and highest for those deposited from methane. Also, the DLC films deposited at higher gas flow rates and lower rf powers offered better protection against corrosion than those deposited at lower gas flow rates and higher rf powers. Annealing improved the corrosion resistance. The corrosion currents for certain DLC/PS/Al/Si samples were about 15 times smaller than those for polyimide (PI)/Al/Si samples.