METHOD AND APPARATUS FOR PRODUCING A PHOTO MASK BLANK, AND APPARATUS FOR REMOVING AN UNNECESSARY PORTION OF A FILM

摘要

in the method of manufacturing a photomask blank , forming a thin film that causes an optical change in the exposure light on the rectangular substrate a thin-film forming step , a resist coating step of applying a positive resist on a film , comprising: a removing step of removing the resist film formed in the baking step of heat-treating the applied resist , and the peripheral portion on the thin film substrate , after the step of removing the resist film forming step haejyeoseo the line and the periphery of the substrate by exposing the resist film prior to the baking step , when carried out one after another from the developer removing step , provided the difference in the solubility or dissolution rate of the developing solution between the exposed portion and the unexposed portion and the exposed portion for a developer solution optionally It is obtained by .