Effect of Using Oblique-Incidence Deposited Ru Interlayers Deposited by Evaporation and Sputtering on Recording Characteristics of Perpendicular Media

Oblique-incidence evaporation and sputtering were performed to investigate the effect of reducing the Ru interlayer thickness on the recording characteristics of perpendicular magnetic recording media. Deep gaps were observed at grain boundaries on oblique-incidence evaporated and sputtered films when the incident angle was over 60^°. Evaporated Ru films have a lower density than sputtered Ru films at the same incident angle. This indicates that the self-shadowing effect predominantly occurs due to suppression of migration of deposited atoms for evaporation films. However, degradation of the crystal orientation is observed in evaporated Ru films due to the present experimental limitations. Examination of the recording characteristics revealed that the Ru interlayer thickness can be reduced by using an oblique-incidence sputtered Ru interlayer and the writing ability can be improved by reducing the spacing loss between the head and the soft magnetic underlayer.