A facile dry-PMMA transfer process for electron-beam lithography on non-flat substrates

This paper presents a simple yet powerful technique that enables the use of high resolution e-beam lithography on irregular substrates by transferring a Dry-Poly (methyl methacrylate) (PMMA) film. The Dry-PMMA film can be patterned and developed via electron-beam lithography before or after the transfer depending on the applications. Then the film can easily be transferred to non-flat or fragile substrates including the sharp tip of a sewing needle, a conical surface, the edge of a silicon wafer, and suspended structures. Specifically, this paper focuses on a transfer method of pre-pattered Dry-PMMA film on sharp substrates. This technique can be applied to a broad range of applications in micro- and nano-technology research areas where a conventional photo-resist spinning method is not available.