Fabrication of 30 nm pitch imprint moulds by frequency doubling for nanowire arrays

We report the fabrication of 30 nm pitch nanowire array imprint moulds by spatial frequency doubling a 60 nm pitch array generated by electron beam lithography. We have successfully fabricated nanowire arrays at a 30 nm pitch, which is targeted for the year 2020 by the International Technology Roadmap for Semiconductors, with an average line-width of 17 nm and a 3σ line width roughness (LWR) of 4.0 nm. In contrast to previously reported procedures, our spatial frequency doubling technique produces electrically isolated nanowires that are appropriate for crossbar circuits.