Directed Self-Assembly of Block Copolymer for Bit Patterned Media with Areal Density of 1.5 Teradot/Inch2 and Beyond
Figure 7
(a) Schematic representation of directed self-assembly of cylinder-forming or sphere-forming BCP thin films by a 1D high-topographic groove pattern. (b) and (c) are SEM images of groove-guided cylinder-forming PS-b-PMMA thin films with a pitch of 27.0 nm (1.0 Td/in2). (d) and (e) are SEM images of groove-guided sphere-forming PS-b-PDMS thin films with a pitch of 22.3 nm (1.5 Td/in2). (f) and (g) are SEM images of groove-guided sphere-forming PS-b-PDMS patterns with a pitch of 15.2 nm (3.2 Td/in2). All the patterns in the left columns are chevron patterns, whereas the patterns in the right columns are stripe patterns. The groove height ranges from 20 nm to 35 nm.
