PHOTOMASK SUBSTRATE PHOTOMASK BLANK PHOTOMASK METHOD FOR MANUFACTURING PHOTOMASK SUBSTRATE METHOD FOR MANUFACTURING PHOTOMASK AND METHOD FOR MANUFACTURING DISPLAY DEVICE

摘要

A photomask substrate capable of minimizing the possibility of generating foreign matter in the cleaning process and capable of suppressing the risk of occurrence of defects in a photomask blank or a photomask manufacturing process. A photomask substrate made of a transparent material for forming a transfer pattern and used as a photomask, comprising: a first main surface for forming a transfer pattern; a second main surface on a back side of the transfer pattern; Respectively. An inclined region is formed near the end of the first main surface, and the inclined region has a first chamfered surface and a first curved surface formed between the first major surface and the first chamfered surface. The first chamfered surface has an inclination angle of 50 degrees or less with respect to the first major surface, and has a plane. The curvature radius r1 (mm) of the first curved surface satisfies 0.3 r1, and the surface roughness Ra of the first curved surface and the first chamfered surface is less than 0.05 mu m.