Multilayer resist methods for nanoimprint lithography on nonflat surfaces

Five multilayer resist methods (three positive tones and two negative tones) have been devised for nanoimprint lithography on nonflat surfaces. Three of the methods have been demonstrated experimentally on a SiO2 surface with 100 nm deep sharp steps. The advantages and disadvantages of each method are discussed. Our results should be applicable to nanoimprint lithography with 10 nm feature size on nonflat surfaces.