Patent ID: 8119017

Claim:
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 0 , where n is an integer equal to or greater than 2; depositing on the patterned substrate a layer of material comprising a block copolymer having a bulk period L 0 , whereby the copolymer material is guided by the stripes to self-assemble into generally radial lines of alternating first and second copolymer components, the radial lines of each component having a circumferential spacing of approximately L 0 ; 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.