Method for repairing photomask by removing residual defect in said photomask

Abstract

A method for repairing a photomask by removing a residual defect in the photomask is provided which can solve problems, involved in repair of the photomask by the conventional laser beam irradiation, such as various types of maladjustments, limitation of focusing of a laser beam, creation of roughening in the repaired area, and problems, involved in repair of the photomask by focused ion beam irradiation, such as damage to a transparent substrate and a gallium stain. The method comprises the steps of: (a) applying actinic radiation to the residual defect area to remove the residual defect except for a defect edge region having a predetermined width from the periphery of the residual defect area over the whole periphery of the residual defect area; and (b) removing the defect edge region, remaining unremoved by the physical means, having a predetermined width from the periphery of the residual defect area over the whole periphery of the residual defect area by chemical etching with a chemical, the predetermined width being such that the influence of the actinic radiation does not extend over the outside of the residual defect area and, at the same time, the etching time can be set so that the region having a predetermined width from the periphery is removed by the chemical etching without any substantial influence on other layers including a light-shielding layer.

Dependencies are inferred from the claim text.