Improvement of Co71Cr19Pt10/Ti90Cr10 perpendicular recording media by independent optimization of film nucleation and growth processes

Abstract

CoCrPt/TiCr perpendicular recording media having independently optimized nucleation and growth conditions have been prepared by changing the argon pressure during sputter deposition of each film. A low argon pressure CoCrPt nucleation layer produces strong c-axis perpendicular orientation that can be maintained during continued CoCrPt deposition at high argon pressure. The two-layer media combines increased particle separation from high pressure growth and strong orientation to produce higher signal to noise ratio than either high pressure or low pressure single layer CoCrPt media. TiCr underlayers, despite poor orientation and a noncolumnar structure, improve CoCrPt c- axis perpendicular orientation. Low argon pressure during TiCr deposition maximizes CoCrPt orientation. A TiCr bilayer having a low pressure nucleation layer followed by a high pressure growth layer improves performance of the subsequent CoCrPt layer. A TiCr bilayer having a high pressure growth layer followed by a thin low pressure template produces even greater recording performance enhancement. This media has Hc=2560 Oe, D50=90 kfci and S0/Nd at 240 kfci=4.0. An identical CoCrPt layer deposited on the low pressure TiCr underlayer has Hc=1850 Oe, D50=80 kfci and S0/Nd at 240 kfci=2.4.