Patent ID: 7976715

Claim:
A method for making a master mold for use in imprinting magnetic recording disks 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; forming 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 components of the coploymer, the radial lines of each component having a circumferential spacing of approximately L 0 ; and forming on the block copolymer material a pattern of concentric rings radially spaced apart by a distance equal to or greater than L 0 .