Patent US 6,133,986

A microscopy and/or lithography system uses a comparatively low-resolution image projection system, which has a very small numerical aperture but large image field, in conjunction with a microlens array comprising miniature lens elements, each of which has a large numerical aperture but very small field. The projection system contains a small aperture stop which is imaged by the microlenses onto an array of diffraction-limited microspots on the microscope sample or printing surface at the microlens focal point positions, and the surface is scanned to build up a complete raster image from the focal point array. The system design thus circumvents the tradeoff between image resolution and field size which is the source of much of the complexity and expense of conventional wide-field, high-NA microscopy and microlithography systems. The system makes possible flat field, distortion-free imaging, with accurate overlay, focus, and warp compensation, over very large image fields (larger than the practical limits of conventional imaging means). In one embodiment it would use a Digital Micromirror Device as the image source, potentially eliminating the need for photomasks in semiconductor manufacture.