Electrochemical fabrication and characterization of CoPt bit patterned media: Towards a wetchemical, large-scale fabrication

This paper describes the fabrication process of CoPt nandot arrays on a glass disk substrate with a CoZrNb underlayer as a soft magnetic underlayer (SUL) by using an electrochemical process, and also the analysis on the magnetic properties of these fabricated CoPt nanodot arrays. We formed nano-patterned substrates by UV-nanoimprint lithography (UV-NIL) on the glass disk substrate. CoPt was electrodeposited into the nano-patterned substrates optimizing the electrodeposition condition and bath composition as well as a Cu intermediate layer. The construction of the nanodot arrays were CoPt nanodot arrays (20 nm)/Cu (<5 nm)/CoZrNb (100 nm)/Cr (5 nm)/Glass disk. Magnetic signals were clearly observed on the dc magnetized state and multi domain were observed in each nanodot on the ac magnetized state by magnetic force microscopy (MFM). The perpendicular coercivity of the CoPt nanodot arrays was 430 kA/m. These results showed electrochemical process can be used for the manufacture of magnetic recording media.