Lithographic patterning and confocal imaging with zone plates

Zone-plate-array lithography (ZPAL) uses an array of zone plates, combined with an array of micromechanical mirrors or shutters, to pattern features o n a substrate without a mask. In this article, we investigate the patternin g characteristics of individual zone plates. We show patterns printed with pixel-dose modulation (gray scaling) and subpixel beam stepping. Using a co mbination of these techniques for linewidth control, edge placement, and pr oximity-effect correction, ZPAL can produce arbitrary patterns with feature s as small as the focal spot of a zone plate. We also demonstrate the use o f zone plates in a confocal-microscopy mode for placing the substrate at th e focus of the zone plates, and for imaging. Zone-plate-array scanning-conf ocal microscopy (ZPAM) could be useful for gapping and alignment in ZPAL, a nd possibly for wafer or mask inspection at deep ultraviolet wavelengths. ( C) 2000 American Vacuum Society. [S0734-211X(00)13106-3].