Large areas of periodic nanoholes perforated in multistacked films produced by lift-off

Abstract

The authors report a low-cost and high-throughput method—nanosphere photolithography, for generating periodic subwavelength holes in metals/dielectrics. By combining the self-assembled and focus properties of micro-/nanospheres, the authors utilized the sphere arrays as lenses to produce large areas of nanopillars with a strong undercut in negative photoresist. Using lift-off with the nanopillars of photoresist, the authors demonstrate a large area of uniform nanoholes of as small as 50 nm in diameter at the bottom of ∼160 nm thick metal. The authors also show that the nanohole arrays can be generated in multistacked layers of different materials and these nanoholes can be processed with different sidewall shapes. The technique promises to be an alternative nanopatterning method that is simple, economical, fast, and flexible.