MULTI-FOCUS METHOD OF ENHANCED THREE-DIMENSIONAL EXPOSURE OF RESIST

摘要

The field of this disclosure is making three-dimensional topographic structures by means of graduated exposure in a photosensitive material, such as a photoresist, photosensitive polymide, or similar. Such patterns may be written either to be used directly as optical, mechanical, fluidic, etc. components, e.g. diffusors, non-reflecting surfaces, Fresnel lenses and Fresnel prisms, computer-generated holograms, lenslet arrays, etc, or to be used as masters for the fabrication of such components by replication. Replication can be done by molding, pressing, embossing, electroplating, etching, as known in the art. This disclosure includes descriptions of using passive absorbing components in thin resist, using high gamma thick resists with high resolution pattern generators, using multiple focal planes including at least one focal plane in the bottom half of the resist, and iterative simulation of patterning and adjustment of an exposure map.