METHOD OF ALIGNING A PARTICLE-BEAM-GENERATED PATTERN TO A PATTERN ON PRE-PATTERNED SUBSTRATE

摘要

A significant improvement in the alignment of a particle-beam-generated pattern relative to a pre-existing pattern present on a substrate has been accomplished using optical measurement to register the particle beam to the pre-existing pattern. Use of a position fiducial which can be accurately measured by both an optical microscope and a particle beam axis is used to align a pre-existing pattern with a particle-beam-generated pattern during writing of the particle-beam-generated pattern. Registration of the pre- existing pattern to the fiducial and registration of the particle beam axis to the fiducial periodically during production of the particle-beam-generated pattern continually provides an improvement in the overall alignment of the pattern being created to the pre-existing pattern on the substrate. The improved method of alignment can be used to correct for drift, or thermal expansion, or gravitational sag, by way of example.