Preparation condition of Co-Pt-Cr-SiO2 films with high coercivity

Preparation conditions of Co-Pt-Cr-SiO2 granular type films for perpendicular recording media were studied. Crystal orientation of the Co-Pt-Cr-SiO2 film directly depended on that of the Ru underlayer. Films with smaller grain size and grain size distribution tended to exhibit higher perpendicular coercivities. The Ar pressure during sputtering of Co-Pt-Cr-SiO2 films and Ru underlayers was found to be an important factor for controlling the surface morphology. A Ta pre-coat layer could improve the crystal orientation of the Ru underlayer and the surface smoothness so that it increased the coercivity of the Co-Pt-Cr-SiO2 films.