Patent ID: 6151101
Filing Date: 2000-11-21
Classification: B82Y,H01J

Abstract:
A charged-particle-beam (CPB) microlithographic projection-exposure apparatus, comprising:(a) a substrate stage on which a sensitive substrate is mounted for CPB projection-exposure of the substrate;(b) a reticle stage on which a reticle is mounted, the reticle defining a pattern to be CPB projection-exposed onto the substrate and being divided into multiple exposure units each defining a respective portion of the pattern;(c) an illumination-optical system situated upstream of the reticle stage, the illumination-optical system comprising multiple CPBillumination-optical components and being configured to sequentially illuminate the exposure units of the reticle with a CPB illumination beam;(d) a projection-optical system situated between the reticle stage and the substrate stage, the projection-optical system comprising multiple CPB-projection-optical components and being configured to project, via a patterned beam propagating downstream of the reticle on the reticle stage, an image of the illuminated exposure unit onto a corresponding location on the sensitive substrate so as to stitch together the exposure-unit images and form an image of the pattern on the substrate; and(e) a controller connected to each of the illumination-optical components and to each of the projection-optical components, the controller being configured to controllably energize each of said components, the controller comprising a memory for storing a look-up table comprising a listing of index data for each of multiple exposure units of the pattern and, for each index datum, corresponding values of imaging parameters pertaining to said components, each index datum being based on a distribution of pattern features within the respective exposure unit, wherein, as an exposure unit is selected for exposure, the controller recalls from the memory the index datum for the exposure unit as well as the corresponding values of imaging parameters, and causes energization of said components according to the recalled values of imaging parameters to perform an optical correction of the image of the respective exposure unit as formed on the substrate.