Patent ID: 6027843
Filing Date: 2000-02-22
Classification: B82Y,H01J

Abstract:
In a method for imprinting an image of a pattern, defined by a reticle mounted on a reticle stage, onto a substrate mounted on a substrate stage using a charged particle beam passing through the reticle, through a projection lens, and through an image-adjustment lens to the substrate, a method for correcting an imaging fault, comprising:(a) projecting the pattern image onto the substrate;(b) detecting a positioning error of a stage from a nominal position, the positioning error resulting in an imaging fault;(c) determining from the detected stage-position error a correction to the imaging fault; and(d) if the determined correction requires an adjustment displacement having a magnitude at or above a preset threshold, then correcting the imaging fault by moving a stage, and if the determined correction requires an adjustment displacement having a magnitude below the preset threshold and requiring an adjustment speed that does not reduce throughput from a level that would otherwise be achieved if no imaging fault were detected, then correcting the imaging fault by adjusting the image-adjustment lens.