Post exposure modification of critical dimensions in mask fabrication

Abstract

A system and method are described for modifying an exposure image in a radiation sensitive layer with a heterogeneous and non-uniform post exposure thermal treatment. The treatment may include providing different thermal flux to different regions of the radiation sensitive layer to concurrently create different temperatures in those regions. The different temperatures may cause different physicochemical transformation of the regions that may be used to reduce critical dimension errors in those regions. A post exposure bake hot plate may be configured to provide heterogeneous radiant energy flux to a radiation sensitive layer by providing adjustable spacers that adjust a separation distance between the hot plate and the layer. The adjustable spacers may be adjusted prior to exposure image modification by using an adjustment plate having openings to provide access to and adjustment of the adjustable spacers.