Pattern transfer and post processing of complex nanostructures formed by e-beam exposure in PMMA

We present results on various post processing techniques to create complex 3-dimensional nanostructures with enhanced capabilities. The starting point for all architectures is a self aligned nanopillar with surrounding circular rim in PMMA. This particular shape is obtained by the energy density distribution of incident and backscattered electrons of e-beam exposure and reflects the dual behavior of PMMA as positive and negative resist. Employing only 1 lithographic step and several batch processing techniques, we ensure that the creation of the complex shapes can be obtained in a reproducible manner without subsequent realignment steps. We propose several applications for these structures, covering a wide variety of research areas. (C) 2011 Elsevier B.V. All rights reserved.