Novel sputtering process to reduce the grain size and its distribution in Co based longitudinal thin film media - new seedlayer and high KU GRAIN material-

This study is aimed at reducing the grain size and its distribution in Co-based longitudinal film media using the UC process as infrastructure. Proposed are two kinds of techniques. The first is the use of Co co-precipitated NiP/Al-alloy substrate (Co-NiP substrate). To reduce the grain size of Cr underlayer grown onto the substrate surface, oxygen exposure is introduced to increase the density of nucleation sites. The second is the use of a very thin W₅₄Cr₄₆ alloy seedlayer combined with dry-etching process. In this concept, the island-like structure at the initial layer is enhanced using a material with high melting point such as W. These techniques are expected to be useful in controlling the density of the nucleation sites of the initial film layer.