MASK BLANK SUBSTRATE, MASK BLANK, REFLECTIVE MASK BLANK, TRANSFER MASK, REFLECTIVE MASK, AND METHOD FOR MAKING THESE

摘要

The purpose of the present invention is to provide a mask blank substrate, mask blank and transfer mask which, during grinding, make it possible to eliminate adverse effects on flatness due to a substrate mark comprising an oblique surface and make it possible to improve flatness, and also to provide a method for making the mask blank substrate, mask blank and transfer mask. A substrate mark (4) comprising an oblique surface is formed in a mask blank substrate (1), the angle of inclination of the substrate mark (4) with respect to a main surface (112) is greater than 45° but less than 90°, and the distance (W₁) from the boundary of the substrate mark (4) with the main surface (112) to the outer periphery of the mask blank substrate (1) is less than 1.5 mm.