Nano-patterning for patterned media using block-copolymer

Block-copolymers are known to generate nano-scale microdomains by microphase-separation, if they are annealed at a temperature lower than their order-disorder transition temperatures. We tried to transfer microdomains onto substrates by only using the reactive-ion etching method, which is widely used in semiconductor manufacturing processes. Block-copolymers consisting of an aromatic polymer and an acrylic polymer were used since there is a big difference in the dry-etch resistance, and nanometer-scale dot patterns can be easily obtained on the substrates. Regarding the application of this nano-patterning technique, we demonstrated the first circumferential magnetic patterned media for hard disk, which were prepared on a 2.5-inch diameter glass plate.