Abstract: The present invention relates to a method for removing etching assist gas from a fabrication system used during defect repair of a photomask in the fabrication of an integrated circuit, including: (a) inspecting the photomask and detecting a defect, the defect in a defect region; and (b) repairing the defect, wherein an amount, effective for the purpose of styrene is added to the system. By the method of the present invention, the amount of gas remaining on the MOS film is reduced, resulting in less surface defects present on the photomask.

Abstract: 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.