Method of forming a photomask of high dimensional accuracy utilizing heat treatment equipment

摘要

Heat is supplied from a base plate located under a photomask blank to the photomask blank in a pre-baking process, and heat is partially supplied from an end surface use plate to the photomask blank so that the intra-planar temperature distribution of the photomask blank becomes uniform through correction of heat radiation from the end surface of the photomask blank. The photomask blank is cooled in a cooling process after the pre-baking process while partially supplying heat from the end surface use plate to the photomask blank so that the intra-planar temperature distribution of the photomask blank becomes uniform through the correction of heat radiation from the end surface of the photomask blank.