Preparation of diamond mold using electron beam lithography for application to nanoimprint lithography

Diamond molds were fabricated by two types of fabrication processes, both o f which use a conductive intermediate layer between the diamond surface and polymethylmethacrylate (PMMA) resist to prevent surface charge-up. Using a PtPd intermediate layer, electron beam lithography and ion beam etching, a denting line pattern of 600 nm width and 70 nm depth was fabricated. Using a carbon intermediate layer, electron beam lithography, PtPd lift-off and oxygen ion beam etching, a convex line pattern of 600 nm width and 110 nm h eight was fabricated. These diamond molds were pressed into PMMA on a silic on substrate that was heated to a temperature of 150 degreesC and kept at a pressure of 23.5 MPa until the temperature dropped below 90 degreesC, and then the diamond mold was released from the PMMA. The convex line pattern o f 600 nn width and 150 nm height was imprinted using a denting diamond mold . The denting pattern of 1100 nm width and 180 nm height was imprinted usin g a convex diamond mold. PMMA patterns were transferred well over the impri nted area, by the diamond molds.