| US 7,549,141 B2 | ||
| Photomask, photomask manufacturing method, and photomask processing device | ||
| Yoshiaki Ikuta, Guilderland, N.Y. (US); Hiroshi Kojima, Hitachinaka (Japan); and Kouji Otsuka, Yokohama (Japan) | ||
| Assigned to Asahi Glass Company, Ltd., Tokyo (Japan) | ||
| Filed on Sep. 12, 2005, as Appl. No. 11/222,979. | ||
| Prior Publication US 2007/0059608 A1, Mar. 15, 2007 | ||
| Int. Cl. G06F 17/50 (2006.01) | ||
| U.S. Cl. 716—19 [716/20] | 17 Claims |
| 1. A method of manufacturing a photomask substrate by a processing device, comprising:
providing a substrate having a surface including a portion on which a predetermined pattern is to be formed and a peripheral
portion outside the portion;
disposing the substrate in a substantially horizontal position, the substrate having the surface facing downward and being
supported at the peripheral portion;
determining an amount of deformation of the surface caused by an external force exerted on the substrate while being supported
at the peripheral portion and being disposed in the substantially horizontal position;
calculating a target surface profile of the surface, based on the amount of deformation and a target flatness of the surface
of the substrate being disposed in the substantially horizontal position; and
removing a surface portion of the substrate so as to obtain the target surface profile.
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