Directed Self-Assembly of Block Copolymer for Bit Patterned Media with Areal Density of 1.5 Teradot/Inch2 and Beyond
Figure 10
(a) Schematic representation of fabricating a servo-integrated BPM template using two types of prepatterns for DSA. All patterns in both data zone and servo zone are BCP dots-array features. DSA in the data zone is guided by a 2D dots-array prepattern, whereas DSA in servo zone is guided by a 1D groove pattern with a top height of . (b) Candela optical images of a 2.4 mm wide imprint circular full track on a 2.5 inch disk. The patterned band contains both the data zone and servo zone at a density of 1.0 Td/in2. (c)–(f) are SEM images of a servo-integrated 1 Td/in2 template fabricated at various stages: (c) BCP pattern. (d) Etched Cr dots as hard mask. (e) Etched fused silica pillars in the data zone. (f) SEM images of servo zone showing several servo features in the template.
