摘要 |
A substrate set is a mask blank substrate set including a plurality of substrates each for use in a mask blank for producing a photomask to be chucked on a mask stage of an exposure apparatus. In each of the substrates in the mask blank substrate set, a main surface, on the side where a thin film for forming a transfer pattern is to be formed, has a convex shape being relatively high at its center and relatively low at its peripheral portion. In each substrate, the flatness in a 142 mm square area, including a central portion, of the main surface is 0.3 μm or less and the difference upon fitting to a reference main surface of a reference substrate is 40 nm or less. |