Parallel optical trap assisted nanopatterning on rough surfaces.

There exist many optical lithography techniques for generating nanostructures on hard, flat surfaces over large areas. However, few techniques are able to create such patterns on soft materials or surfaces with pre-existing structure. To address this need, we demonstrate the use of parallel optical trap assisted nanopatterning (OTAN) to provide an efficient and robust direct-write method of producing nanoscale features without the need for focal plane adjustment. Parallel patterning on model surfaces of polyimide with vertical steps greater than 1.5 µm shows a feature size uncertainty better than 4% across the step and lateral positional accuracy of 25 nm. A Brownian motion model is used to describe the positional accuracy enabling one to predict how variation in system parameters will affect the nanopatterning results. These combined results suggest that OTAN is a viable technique for massively parallel direct-write nanolithography on non-traditional surfaces.