Abstract: Disclosed is a polishing agent for synthetic quartz glass substrates, which is characterized by containing a colloidal solution of a colloidal silica or the like having a colloid concentration of 20-50% by mass, and a polycarboxylic acid polymer, an acidic amino acid, a phenol or a glycosaminoglycan.

Abstract: A photomask-forming glass substrate having a square major surface is provided wherein two strip regions are defined on the major surface near a pair of opposed sides such that each region spans between 2 mm and 10 mm inward of the side and excludes end portions extending 2 mm inward from the opposed ends of the side, a least squares plane is computed for each of the two strip regions, the angle included between normal lines to the least squares planes of two strip regions is within 10 seconds, and the height difference between two strip regions is up to 0.5 ?m.

Abstract: Disclosed is a polishing agent for synthetic quartz glass substrates, which is characterized by containing a colloidal solution of a colloidal silica or the like having a colloid concentration of 20-50% by mass, and a polycarboxylic acid polymer, an acidic amino acid, a phenol or a glycosaminoglycan.

Abstract: A photomask-forming glass substrate having a square major surface is provided wherein two strip regions are defined on the major surface near a pair of opposed sides such that each region spans between 2 mm and 10 mm inward of the side and excludes end portions extending 2 mm inward from the opposed ends of the side, a least squares plane is computed for each of the two strip regions, the angle included between normal lines to the least squares planes of two strip regions is within 10 seconds, and the height difference between two strip regions is up to 0.5 ?m.

Abstract: A photomask-forming glass substrate having a square major surface is provided wherein two strip regions are defined on the major surface near a pair of opposed sides such that each region spans between 2 mm and 10 mm inward of the side and excludes end portions extending 2 mm inward from the opposed ends of the side, a least squares plane is computed for each of the two strip regions, the angle included between normal lines to the least squares planes of two strip regions is within 10 seconds, and the height difference between two strip regions is up to 0.5 ?m.

Abstract: A large-size synthetic quartz glass substrate is produced by measuring a flatness and parallelism of front and back surfaces of a synthetic quartz glass substrate stock having a diagonal length of at least 1,000 mm, and partially removing raised portions and thick portions of the substrate stock on the basis of the measured data of flatness and parallelism. The removing step includes abrasive working by a first working tool having a diameter of 15-50% of the diagonal length, and abrasive working by a second working tool having a smaller diameter.

Abstract: A large-size substrate adapted for light exposure is of a plate shape having a diagonal length or diameter of 500-2,000 mm, a thickness of 1-20 mm, and a peripheral surface with a roughness Ra of 0.05-0.4 ?m. The number of particles released from the substrate periphery during cleaning is minimized, leading to an improved yield in the cleaning step. The substrate can be manually handled, achieving an improvement in substrate quality without a need for a handling mechanism.

Abstract: A photomask-forming glass substrate having a square major surface is provided wherein two strip regions are defined on the major surface near a pair of opposed sides such that each region spans between 2 mm and 10 mm inward of the side and excludes end portions extending 2 mm inward from the opposed ends of the side, a least squares plane is computed for each of the two strip regions, the angle included between normal lines to the least squares planes of two strip regions is within 10 seconds, and the height difference between two strip regions is up to 0.5 ?m.

Abstract: A used large-size photomask substrate having a patterned light-shielding film is recycled by (i) removing the light-shielding film from the used substrate to provide a photomask-forming glass substrate stock, (ii) resurfacing the glass substrate stock by sand blasting, (iii) repolishing the resurfaced glass substrate stock to yield a regenerated glass substrate stock, (iv) applying a light-shielding film onto the regenerated glass substrate stock to yield a regenerated photomask-forming blank, and (v) processing the light-shielding film of the blank into a pattern corresponding to a desired exposure of a mother glass, yielding a regenerated photomask substrate.

Abstract: A large-size synthetic quartz glass substrate is produced by measuring a flatness and parallelism of front and back surfaces of a synthetic quartz glass substrate stock having a diagonal length of at least 1,000 mm, and partially removing raised portions and thick portions of the substrate stock on the basis of the measured data of flatness and parallelism. The removing step includes abrasive working by a first working tool having a diameter of 15-50% of the diagonal length, and abrasive working by a second working tool having a smaller diameter.

Abstract: Disclosed is a polishing agent for synthetic quartz glass substrates, which is characterized by containing a colloidal solution of a colloidal silica or the like having a colloid concentration of 20-50% by mass, and a polycarboxylic acid polymer, an acidic amino acid, a phenol or a glycosaminoglycan.

Abstract: A large-sized substrate having a diagonal length of not less than 500 mm and a ratio of flatness/diagonal length of not more than 6×10?6 is disclosed. By use of the large-sized substrate for exposure of the present invention, the exposure accuracy, particularly the register accuracy and resolution are enhanced, so that it is possible to achieve high-precision exposure of a large-sized panel. With the processing method according to the present invention, it is possible to stably obtain a large-sized photomask substrate with a high flatness, and since the CD accuracy (dimensional accuracy) at the time of exposure of the panel is enhanced, it is possible to perform exposure of a fine pattern, leading to a higher yield of the panel. Furthermore, by applying the processing method according to the present invention, it is also possible to create an arbitrary surface shape.

Abstract: A large-size glass substrate, from which a photomask substrate is formed, is prepared by processing a large-size glass substrate stock by (1) a flattening removal quantity based on height data of the substrate stock in the vertical attitude plus a deformation-corrective removal quantity. The deformation-corrective removal quantity is calculated from (2) a deflection of the substrate stock by its own weight in the horizontal attitude, (3) a deformation of the photomask substrate caused by chucking in an exposure apparatus, and (4) an accuracy distortion of a platen for supporting a mother glass.

Abstract: A wafer substrate is polished by disposing the wafer substrate between an abrasive cloth on a polishing platen and a plate, and relatively rotating the polishing platen and the plate for mirror polishing the surface of the wafer substrate with the abrasive cloth. A liquid is fed onto the plate side surface of the wafer substrate so that the wafer substrate is directly held to the plate by the adsorption force of the liquid, while performing the mirror polishing.

Abstract: A large-size glass substrate, from which a photomask substrate is formed, is prepared by processing a large-size glass substrate stock by (1) a flattening removal quantity based on height data of the substrate stock in the vertical attitude plus a deformation-corrective removal quantity. The deformation-corrective removal quantity is calculated from (2) a deflection of the substrate stock by its own weight in the horizontal attitude, (3) a deformation of the photomask substrate caused by chucking in an exposure apparatus, and (4) an accuracy distortion of a platen for supporting a mother glass.

Abstract: A used large-size photomask substrate having a patterned light-shielding film is recycled by (i) removing the light-shielding film from the used substrate to provide a photomask-forming glass substrate stock, (ii) resurfacing the glass substrate stock by sand blasting, (iii) repolishing the resurfaced glass substrate stock to yield a regenerated glass substrate stock, (iv) applying a light-shielding film onto the regenerated glass substrate stock to yield a regenerated photomask-forming blank, and (v) processing the light-shielding film of the blank into a pattern corresponding to the desired exposure of a mother glass, yielding a regenerated photomask substrate.

Abstract: A large-sized substrate having a diagonal length of not less than 500 mm and a ratio of flatness/diagonal length of not more than 6×10?6 is disclosed. By use of the large-sized substrate for exposure of the present invention, the exposure accuracy, particularly the register accuracy and resolution are enhanced, so that it is possible to achieve high-precision exposure of a large-sized panel. With the processing method according to the present invention, it is possible to stably obtain a large-sized photomask substrate with a high flatness, and since the CD accuracy (dimensional accuracy) at the time of exposure of the panel is enhanced, it is possible to perform exposure of a fine pattern, leading to a higher yield of the panel. Furthermore, by applying the processing method according to the present invention, it is also possible to create an arbitrary surface shape.

Abstract: A large-sized substrate having a diagonal length of not less than 500 mm and a ratio of flatness/diagonal length of not more than 6.0×10?6 is disclosed. By use of the large-sized substrate for exposure of the present invention, the exposure accuracy, particularly the register accuracy and resolution are enhanced, so that it is possible to achieve high-precision exposure of a large-sized panel. With the processing method according to the present invention, it is possible to stably obtain a large-sized photomask substrate with a high flatness, and since the CD accuracy (dimensional accuracy) at the time of exposure of the panel is enhanced, it is possible to perform exposure of a fine pattern, leading to a higher yield of the panel. Furthermore, by applying the processing method according to the present invention, it is also possible to create an arbitrary surface shape.

Abstract: A wafer substrate is polished by disposing the wafer substrate between an abrasive cloth on a polishing platen and a plate, and relatively rotating the polishing platen and the plate for mirror polishing the surface of the wafer substrate with the abrasive cloth. A liquid is fed onto the plate side surface of the wafer substrate so that the wafer substrate is directly held to the plate by the adsorption force of the liquid, while performing the mirror polishing.

Abstract: A large-size substrate having improved flatness is prepared by measuring the flatness of one surface or opposite surfaces of a large-size substrate having a diagonal length of at least 500 mm, and partially removing raised portions on the one surface or opposite surfaces of the substrate by means of a processing tool on the basis of the measured data. The processing tool is adapted to blast a slurry of microparticulates in water carried on compressed air against the substrate.