Two nanometer IBD overcoats development for magnetic and tribology improvement

To reduce the overcoat thickness to achieve higher recording density, 2 nm carbon overcoat produced by ion-beam-deposition (IBD) was designed to replace conventional IBD/sputtered-CN dual layer overcoat. Different combinations of overcoat films were deposited with various thicknesses by DC sputter or IBD. Optimized Z-Tol lubricant and additive were coated on the overcoat films. We found that a new designed IBD overcoat with optimized lubricant can effectively decrease the total head-disk spacing interface which results in 1.5 dB OW, 0.4 dB SNR, 0.7 dB SpN and 0.013 dBm Nm, better and higher than the previous design. It also shows promising tribological performance due to the more diamond like structure and higher lubricant bonding ratio.