Large-area patterning for photonic crystals via coherent diffraction lithography

A new method for lithographically patterning a large-area hexagonal lattice of circular holes is proposed, which is particularly suitable for the fabrication of 2D and 3D photonic crystals (PhC). The method, which we call coherent diffraction lithography (CDL), is based on the interference of beams diffracted from a mask containing a periodic pattern, often referred to as the Talbot effect. We demonstrate the replication of large-area hexagonal lattices using CDL, and investigate the most critical parameters of this technique.