We present a method for fabricating three-dimensional photonic crystal
structures by interference lithography, capable of generating face-centered cubic lattices with lattice periods that can be controllably varied over a wide range. The method consists of three separate exposures of a layer of photoresist by interfering laser beams, where each exposure generates a two-dimensional interference pattern, specifically a tilted set of parallel rods. When properly oriented, superimposing these three rod arrays within a common volume of resist material yields an fcc lattice. The lattice period is controlled by the spacing of the rod arrays, which can be tuned independently of the laser wavelength by varying the relative orientations of the interfering beams. We have developed a method for generating the necessary laser beams that is highly repeatable and requires zero alignment, using an array of diffraction gratings patterned on a single mask plate and a rotating beam blocker to select which subset of the grating array is to be used for any given exposure. This paper contains a description of the method and our fabrication setup, and presents the samples that have been fabricated using this method.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.