Flexible coherent diffraction lithography is proposed and preliminarily tested by means of an optical phase mask. The phase mask consisted of a two-dimensional hexagonal lattice of reversed ferroelectric domains engineered in a z-cut lithium niobate substrate and was electro-optically tunable. Appropriate phase shift values across adjacent reversed domains were induced by the application of an external electric field along the z-axis of the crystal via transparent electrodes. Photolithographic exposures of the self-imaging near-field diffraction intensity patterns, at various planes corresponding to the Talbot distances, were performed by using different values of the driving electric field signal.
15 Apr 2008
Volume: 281 Issue: 8 Pages: 1950-1953