Patent ID: 8119017
Filing Date: 2012-02-21
Classification: G11B

Abstract:
1. A method for making a master mold for use in imprinting magnetic recording disks, the method including the use of a block copolymer having a bulk period L 0 and comprising: forming on a substrate having a center a pattern of generally radial stripes arranged in an annular band, the stripes having a circumferential spacing of approximately nL depositing on the patterned substrate a layer of material comprising a block copolymer having a bulk period L removing the radial lines of the first copolymer component, leaving the radial lines of the second copolymer component; forming over the radial lines of the second copolymer component a resist pattern of concentric rings; etching portions of the radial lines of the second copolymer component unprotected by the resist; removing the resist, leaving a pattern of pillars of second copolymer component; etching the substrate, using the pillars of second copolymer component as an etch mask; and removing the pillars of second copolymer component, leaving a substrate with a pattern of pillars of substrate material.