Reduction of initial film-growth layer of CoCrPt based perpendicular recording media was investigated using TiCr, CoCr and Ru seed layers. The initial layer has small perpendicular magnetic anisotropy K_u, and the thickness of the initial layer was about 10〜15 nm with TiCr seed layer, and 1-6nm with CoCr or Ru Seed layers. X-ray diffraction patterns and TEM images indicated that the initial layer contains fcc-like structure. Moreover, a lot of stacking faults exist in the CoCrPt based perpendicular films even with CoCr or Ru seed layers. The improvement of epitaxial film growth by using CoCr or Ru seed layers is very effective to reduce the thickness of the initial layer, while is found to prevent the segregation of Cr from Co, resulting in larger intergranular exchange coupling.
