Can synthetic aperture techniques be applied to optical lithography?

Abstract

This article discusses the theoretical feasibility of applying optical aperture synthesis to lithography. A technique involving the insertion of three phase gratings into a conventional projection system is described. While this approach paraxially yields imaging with doubled spatial bandwidth, aberrations introduced by the gratings are shown to be a serious limitation. Image simulations demonstrated that for very restricted pattern types, resolution down to 0.1 μm is theoretically achievable.