[Ni-Fe/Si] double seedlayer with low surface energy for Fe-Co-B soft magnetic underlayer with high Hk for perpendicular magnetic recording media

Fe-Co-B layers deposited on Ni-Fe seedlayer exhibited a high in-plane anisotropy field H_k of 280 Oe caused by inclined incident angle of sputtered particles. Ni-Fe/Si double seedlayer with low surface energy led to increase the effect of inclined incident angle. For more increase of the H_k in Fe-Co-B layer, a control of surface energy in Ni-Fe seedlayer was investigated. An improvement of closest packing plane (111) crystallites orientation led to reduce the surface energy in Ni-Fe layer. The adhesive force of Ni-Fe(10 nm) deposited on Si(2 nm) layer with (111) crystallites orientation exhibited 475 nN corresponding to about 65% of that of Ni-Fe(10 nm) single layer with random orientation. [Ni-Fe/Si] double seedlayer with lower adhesive force was effective in attaining a small crystallites size as well as finer grains in Fe-Co-B layer. Moreover, the H_k increased up to 380 Oe in Fe-Co-B layer on [Ni-Fe/Si] double seedlayer with lower adhesive force.