Photolithographic mask and apparatus and method of use thereof

Abstract

A photolithographic system uses a mask that carries a plurality of photolithographic images. In one embodiment, the mask carries images for all the layers necessary to manufacture a variety of different device cells, which can include devices of different types. A single mask may carry the images required to make a complete system consisting of multiple devices. Some devices may comprise multiple layers. The system includes an adjustable aperture system which defines the area of the mask which will be illuminated. The mask is employed in a mask aligner which includes a source of electromagnetic radiation, apparatus to carry and position a substrate, apparatus to position the mask, and apparatus to position and adjust the aperture. The process requires the successive steps of supporting a photoresist-carrying substrate, positioning the mask to register a selected photolithographic image with the substrate, positioning and adjusting the aperture to expose the desired image, and illuminating the radiation source to imprint the chosen image on the substrate. The alignment process may be repeated multiple times with the same mask and adjustable aperture so as to imprint other images of the corresponding layer of other devices elsewhere on the substrate. The substrate is processed to produce the layers of the devices so imprinted. The photolithographic process may then be repeated to imprint successive layers of the various devices, each in registry with the corresponding underlying layers.