Ultrathin CNx overcoats for 1 Tb/in.2 hard disk drive systems

Abstract

Subnanometer scale tribological properties of nitrogen containing carbon coatings used in magnetic storage devices J.Continuity and topography of ultrathin diamond-like carbon films characterized by scanning electron microscopy/energy dispersive x-ray analysis and atomic force microscopy Carbon nitride films were grown on silicon and hard disk substrates using pulsed dc magnetron sputtering in a single-cathode deposition system. Substrates were mounted on a specially designed holder that allowed 45°tilt angle and substrate rotation about the surface normal up to 20 rpm. The influence of substrate bias, substrate tilt, and rotation on film growth and properties was studied. Films with the lowest rms surface roughness and corrosion performance were obtained at Ϫ100 V substrate bias with substrate tilt and rotation. Atomic force microscope scans over 10ϫ10 m 2 sampling areas showed that 50 nm thick CN x films prepared under these conditions have roughness almost four times lower than those prepared without substrate tilt and rotation. We observed a twofold reduction in corrosion damage for hard disk substrates with 1 nm thick CN x overcoats deposited with substrate tilt and rotation. This improved performance is likely a result of more efficient and uniform momentum transfer parallel to the surface during deposition in this configuration.

Growth of nano crystalline near α phase tantalum thin films at room temperature using cylindrical magnetron cathode

“…So far, the energy of the depositing adatoms is mainly controlled by the substrate heating or ion bombardment [15][16][17], which have limitations while coating on substrates used in microelectronics industry [18,19]. The oblique incidence of adatoms or reflected sputter gas atoms are reported to have maximum momentum transfer on the surface of the films yielding results similar to that of local heating on the surface of the growing film [20]. The use of pulsed power is reported to result in an increased power flux on to the substrate [21].…”

“…It is known from the earlier reports [20] that oblique incidence of adatoms influences the nucleation and structure of the growing film. In the present deposition process, there is enough neutral (reflected Ar neutrals) and sputtered atom flux bombarding the adatoms at oblique incidence which enhances the energy of the adatoms over the substrates resulting in the formation of films with a different surface morphology (to attain stable phase) influencing the nucleation and the internal energy (phase) of the Ta films within the nucleation length.…”

“…The use of pulsed power is reported to result in an increased power flux on to the substrate [21]. Following the concepts of oblique incidence [20] and enhanced electron temperature due to pulsing the target power [21], the present paper reports, the growth of high content of nano α phase tantalum thin films at room temperature using a newly designed cylindrical …”

Plasma assisted techniques for deposition of superhard nanocomposite coatings

“…In addition, there was no deposition for half a rotation cycle. Therefore, there was more time available for migration of surface species to fill in voids resulting in a denser structure [102]. The hardness of rotated coatings reached values of 60 GPa and even slightly increased after 1 hour of annealing in argon at 1000ºC, while the hardness of non-rotated ones was well below 40 GPa.…”

In vitro comparison of the hemocompatibility of diamond-like carbon and carbon nitride coatings with different atomic percentages of N

“…Because these elements are widely spread in the human body, CN x may possess excellent biocompatibility. In our previous study [19], magnetron sputtering was employed to fabricate smooth CN x coatings with acceptable corrosion performance. In this work, our aim was to prepare CN x coatings using standard magnetron sputtering, and study the effects of the atomic concentration of N on blood-clotting time as well as platelet adhesion to the coatings.…”