Oxide mobility enhancement due to bias sputtering in perpendicular recording media

This study addresses some consideration of oxide mobility in two types of oxide composite perpendicular media A (CoCrPt-SiO₂) and B (FePt-MgO). The effects of bias sputtering on the morphology of the deposited composite film was examined. Results show that although the preferential sputtering seems different, the enhanced grain separation in the biased films is similar for the two media, which suggests that biasing is generally effective in driving the segregation. This is ascribed to an increase in Ar ion bombardment of the substrate during bias sputtering, which helps to increase mobility of the oxide molecules on the growing surface such that they reach grain boundaries.