CONTACT HOLE PRINTING METHOD AND APPARATUS WITH SINGLE MASK, MULTIPLE EXPOSURES, AND OPTIMIZED PUPIL FILTERING

摘要

The present invention provides a lithographic method and apparatus (e.g., for printing contact holes on a wafer) that use a single mask, multiple exposures, and optimized pupil filtering. The method comprises: providing a mask including pattern features to be transferred to a wafer; transferring a first set of pattern features from the mask to the wafer using a first type of illumination and a first type of pupil filter; and transferring a second set of pattern features from the mask to the wafer using a second type of illumination and a second type of pupil filter.