C-axis orientation of Co-Cr thin films by facing targets sputtering

Sputtered Co-Cr thin films have been extensively investigated as one of the most promising media for the perpendicular magnetic recording. In this study, the dependence of the c-axis dispersion ΔΘ50on the film thickness δ has been investigated using the Facing Targets Sputtering (FTS) apparatus and the conventional DC planar magnetron sputtering (DCM) one. The films deposited by DCM exhibited a considerable dependence of ΔΘ50on δ below 4,000 Å. This was mainly attributed to the bombardment of γ-electrons ejected from the central area of the target where the magnetic field is not so strong as to confine them. However, the films deposited by FTS did not show the significant dependence of ΔΘ50on δ and it was less than 5 degrees even at δ as thin as 200 Å. This result indicates that the FTS system developed by the authors may be very suitable to prepare Co-Cr thin films for high density perpendicular magnetic recording media.