Reregistration system for a charged particle beam exposure system

摘要

A reregistration system for determining and positioning the location of a substrate target surface with respect to a plurality of charged particle beams used to directly write an integrated circuit pattern simultaneously at a plurality of locations on the substrate is disclosed. Reregistration is accomplished by scanning two or more of the charged particle beams over a corresponding number of reregistration fiducial marks on the substrate. The reregistration marks may consist of a material having a high atomic number or predefined topographical features. Electrons scattered from these marks are detected and converted to electrical signals. The temporal relationship between the scanning beams and the resultant electrical signals may then be used to determine substrate location.