Sputtering of high coercivity/low noise CoCrTa bilayered hard disks in a manufacturing system

The magnetic properties and recording performance of mono- and symmetrically bilayered Cr-CoCrTa layer stacks are compared. The media coercivity changes drastically at thin intermediate Cr thicknesses d with a d/sup -0.74/ dependence between 1 and 5 nm and a monotonic increase at d greater than 5 nm. The media noise is reduced by 4-5 dB at very thin intermediate Cr, the M-H loop is square and PW/sub 50/ values are the same for mono- and bilayered films. The stability of the process was investigated and the manufacturing of disks was demonstrated in a production sputtering system.<
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