Fabrication of FePt patterned media with diblock copolymer templates

Abstract

We apply self-assembly pattern of diblock copolymers for fabrication of patterned magnetic media. FePt dot arrays with 30 nm center-to-center distance have been fabricated using self-assembled pattern formation of polystyrene-polymethylemethacrylate(PS-PMMA) diblock copolymer. The FePt dot arrays have strong perpendicular anisotropy. Increase of coercive force in easy axis from 4.5 kOe for a film structure to 13 kOe for a dot structure is observed. No significant deterioration of crystal structures is observed on the sidewall of the FePt dots which is possibly attributable to weak damage during ion beam etching. Also fabrication of aligned FePt dot arrays on circumferential lines is also demonstrated using assisted self-assembly of PS-PMMA diblock copolymers by groove guide patterns. ©2006TAPJ.