Utilizing vacuum ultraviolet (VUV) exposure to remove halos of carbon deposition in clear reticle repair

摘要

The present invention relates to a method of removing halos resulting from focused ion beam (FIB) repair of clear defects on reticles. The halos are formed during carbon deposition on clear defects. An exposure with 172 nm VUV radiation is used to vaporize the carbon compounds in the halo. MSM measurements of the space width adjacent to the repair site are compared to space widths between similar features in areas that are clear of halos. The radiation and measurement is repeated until the % variation between said space widths is <2%. Cleaning and MSM measurement steps are repeated until space width adjacent to the repair site is within 2% of space width in unaffected areas. This method avoids expensive rework and restores transmission through the substrate adjacent to the repair site to a value equivalent to regions of substrate unaffected by halos.