Patent ID: 6632722
Filing Date: 2003-10-14
Classification: B82Y,H01J,H01L

Abstract:
A method for fabricating a fiducial mark body for placement on a wafer stage of charged-particle-beam (CPB) microlithography apparatus and used to perform alignments of said apparatus, the method comprising:providing an electrically non-conductive substrate plate made of a material having a coefficient of thermal expansion of 10âˆ’7/Â° C. or less; applying a layer of a heavy metal to the substrate plate, the layer having a thickness greater than a critical thickness of the heavy metal; defining, in the layer of heavy metal, mark elements; removing heavy metal from regions other than the mark elements such that the thickness of any remaining heavy metal other than the mark elements is in the range of zero to a thickness that is less than the critical thickness of the heavy metal; and applying a layer of an electrically conductive material to the substrate plate, the layer having a thickness less than a critical thickness of the electrically conductive material.