Seedlayer and preheating effects on crystallography and recording performance of CoCrPtB perpendicular media

Development of Media Nanostructure for Perpendicular Magnetic Recording

“…As explained in the previous section, the nanostructure of recording layer must be controlled simultaneously in the crystal orientation, the grain diameter, as well as the separation between magnetic grains with a presence of thin nonmagnetic layer. Dual layer structures of hcp-Ru/Ta 42,43) , hcpRu/Ni-W, or even more complicated stacked structures 101,102) were employed as the intermediate layer, where the first layer of Ta or Ni-W provided a surface condition that promoted free nucleation of hcp-Ru crystal with the (0001) basal plane, energetically most stable plane, parallel to the surface. A sputter deposition consisting of low Ar pressure deposition followed by high Ar pressure deposition for the Ru layer preparation was employed to produce an intermediate layer with the caxis oriented dome-like Ru crystal grains which were effective in enhancing nonmagnetic SiOx segregation around the Co-alloy magnetic crystal grains 101,102) .…”

“…Underlayer materials were then extended to nonmagnetic hcp-CoCr 31,32) , hcpRu 30,33) , fcc-Au, fcc-Al 34) , fcc-Pt 35) , etc. and dualunderlayer structures; Ti/Ge 36) , CoCr/TiCr 37,38) , Co3O4/Pt 35) , Pt/Ti 39) , Pd/Ti 40) , CoCrRu/TiCr 41) , Ru/Ta 42,43) , Ru-oxide/Ru 44) , etc. for the preparation of PMR media.…”

Effect of material selection and background impurity on interface property and resulted CIP-GMR performance

“…It provides a very good ''wetting'' base for Ru growth. Zheng et al [9] reported that Ta/Ru provided much better texture growth Table 1 Crystal structure, lattice constants [16,17], and the corresponding densely packed crystal plane d-spaces for various metals and their alloys commonly used for CIP-GMR devices. for Co (0 0 0 2) for perpendicular recording medium, compared with Ru seed layer only.…”

“…Those interfaces can significantly affect the AFM texture development (and the corresponding AFM pinning field and blocking temperature), SAF coupling strength, interface spin-dependent electron scattering, and thus the achievable overall GMR performance. For example, it has been found that the seed layer material selection [9][10][11][12][13], critical seed layer thickness [10,11,14], oxygen impurity content [15] had strong impact on the AFM texture growth, its grain size, and the corresponding GMR ratio of the film stack. Background impurity effect can be more profound when high oxygen-affinity seed layer (like Ta) is used.…”

Effects of varying CoCrV seed layer deposition pressure on Ru crystallinity in perpendicular magnetic recording media

“…Deposition of an additional seed layer such as Ti and Ta between the SUL and the Ru layer is a common technique and has been used to improve the media structure and the resulting performance. [6][7][8] Significant research has already been dedicated to the effects of deposition parameters on the Ru layer, including substrate temperature, sputtering power, sputtering pressure, and substrate bias. [9][10][11][12] While research on the relationship between Ru deposition parameters and Ru layer properties has been very thorough, focus on the effects of the deposition parameters of the seed layer ͑such as Ti or Ta͒ on the structural properties of the Ru layer has so far been limited to substrate biasing.…”