Evaluation of ordering of directed self-assembly of block copolymers with pre-patterned guides for bit patterned media

Abstract

Bit patterned media (BPM) is a promising candidate for next-generation magnetic recording media beyond 2.5 Tb/in 2 . To realize such high-density patterned media, directed self-assembling (DSA) technology is a possible solution to form fine dots. In order to read and write magnetic signals on a magnetic dot of magnetic media, the position of magnetic dots must be controlled. We examined ordering of directed self-assembly of diblock copolymer dots with a variety of prepatterned guides in some conditions and evaluated the ordering of the dots by using Delaunay triangulation and Voronoi diagram. Applying the optimized conditions, we obtained highly controlled dot pattern suitable for magnetic recording media.

Photopatternable Interfaces for Block Copolymer Lithography

“…Control of the two-dimensional spatial arrangement of domains in which there are distinct regions of perpendicular and parallel lamellae in a single thin film layer is a critical patterning requirement for many lithographic applications, including production of field effect transistors (FETs), bit-patterned media for hard disk drives, and surface plasmonic waveguides . For example, line-space patterns generated by perpendicular lamellae are important for producing key FinFET features, but individual layers in these devices and other circuit-relevant patterns contain many other pattern motifs, including large featureless regions. , A methodology that would enable defining both servo information areas and areas of bit-patterned magnetic media in a single lithographic layer through control of the orientation of BCP lamellae would be very valuable for hard disk drive manufacturers. − …”