Patent ID: 9348217
Filing Date: 2016-05-24
CPC Classification: G03F,H01L

Claim Text:
1. A mask blank substrate for use in lithography, wherein a main surface of the substrate satisfies a relational equation of (BA 70 −BA 30 )/(BD 70 −BD 30 )≧350 (%/nm), and has a maximum height (Rmax)≦1.2 nm in a relation between a bearing area (%) and a bearing depth (nm) obtained by measuring, with an atomic force microscope, an area of 1 μm×1 μm in the main surface on the side of the substrate where a transfer pattern is formed, wherein BA 30 is defined as a bearing area of 30%, BA 70 is defined as a bearing area of 70%, and BD 70 and BD 30 are defined to respectively represent bearing depths for the bearing area of 30% and the bearing area of 70%.