Low surface energy and corrosion resistant ultrathin TiSiC disk overcoat

Ultra-thin films of titanium silicon carbide (TiSiC) were deposited by magnetron sputtering (using Ti2SiC3 targets) to form protection overcoats (OCs) onto magnetic recording media of hard disk drives. The chemico-physical properties (composition, optical constants, electrical resistivity, mass density, and surface energy) of titanium silicon nitride (TiSiN) films were measured and correlated to their OC performances in terms of protection against Si oxidation, Co corrosion, and Co diffusion. Performances of TiSiC OCs were compared to those of silicon carbide (SiC), silicon nitride (SiN), and TiSiN OCs. It was found that Ti incorporation into SiC and SiN considerably densifies the films, reduces their surface energy, and renders them more metallic. 25 angstrom thick TiSiC OC forms stable protecting barriers than can sustain hydrolysis conditions without growth of surface silicon oxide or cobalt diffusion or oxidation in the underlying recording magnetic medium. Overall, TiSiC OCs outperformed TiSiN, SiC, and SiN OCs as disk protection layers. We could directly correlate good protection against surface silicon oxide formation with film's lower surface energy, and good protection against Co diffusion with film's higher mass density. (C) 2013 AIP Publishing LLC.