Stamps for nanoimprint lithography fabricated by proton beam writing and nickel electroplating

In the emerging fields of nanoscience and nanotechnology, the demands for low-cost and high-throughput nanolithographic techniques have increased. Nanoimprint lithography is considered as one of the candidates showing high potential for nanofabrication, and here we report a fabrication process that utilizes high-quality nickel stamps with micron features down to sub-100 nm, made using proton beam writing coupled with nickel sulfamate electroplating. The fabricated stamps have a high aspect ratio, with smooth and vertical sidewalls. Nanoindentation and atomic force microscopy (AFM) measurements of the features on the surface of the stamps indicate a hardness of 5 GPa and a sidewall roughness of 7 nm. The stamps have been used for nanoimprint lithography on polymethylmethacrylate (PMMA) substrates and the imprinted patterns show a high degree of reproducibility.