Directed Self-Assembly of Block Copolymer for Bit Patterned Media with Areal Density of 1.5 Teradot/Inch2 and Beyond
Figure 8
(a) Schematic representation of fabricating a hole-tone dots-array template on a fused silica substrate using cylinder-forming PS-b-PMMA thin films. (A) spin coating of PS-b-PMMA film on a 2D chemical prepattern surface, (B) thermal annealing BCP film, (C) removal of PMMA block, and (D) fused silica etch using CHF3 ion beam etching. (b) Large-scale SEM image of a 1.0 Td/in2 hole-tone dots-array template (). (c) A fabricated 6 inch fused silica template. (d) Magnified SEM image of a hole-tone dots template and (e) cross-sectional SEM image of template showing vertical sidewall with an etched depth of about 30 nm.
