Palladium-based intermediate layers for CoCrPt-SiO2 perpendicular recording media

CoCrPt-SiO2 perpendicular recording media containing Pd and Ru based intermediate layers have been studied. A Pd thin film with a face-centered-cubic (fcc)[111] orientation perpendicular to the film plane can induce a Ru hexagonal close packed (hcp) [0002] perpendicular orientation, which can subsequently induce a vertical Co hcp [0002] orientation for the perpendicular recording. It was observed that certain growth control layers (GCLs), such as Ta and CrTi, help in improving the growth of Pd significantly with a fcc[111] orientation perpendicular to the film plane. With the addition of such layers, the full width at half maximum (Delta theta(50)) of the rocking curves was reduced from more than 11 degrees to about 4 degrees. Moreover, with a CrTi GCL, the intermediate layer could be as thin as 15 nm. Recording performance of disks with CrTi GCL was better than that of disks with Ta GCL. The results indicate that the identification of a suitable GCL for Pd is a path to reduce the Delta theta(50) further.