Ultra-thin α-SiNxprotective overcoats for hard disks and read/write heads

This paper reports that amorphous silicon nitride ( a -SiN x ) overcoats were deposited at room temperature by microwave ECR plasma enhanced unbalanced magnetron sputtering. The 2 nm a -SiN x overcoat has better anti-corrosion properties than that of reference a -CN x overcoats (2–4.5 nm). The superior anti-corrosion performance is attributed to its stoichiometric bond structure, where 94.8% Si atoms form Si–N asymmetric stretching vibration bonds. The N/Si ratio is 1.33 as in the stoichiometry of Si 3 N 4 and corresponds to the highest hardness of 25.0 GPa. The surface is atomically smooth with RMS < 0.2 nm. The ultra-thin α-SiN x overcoats are promising for hard disks and read/write heads protective coatings.