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Masabumi Ito, Tokyo JP

Masabumi Ito, Tokyo JP

Patent application numberDescriptionPublished
20080311487GLASS SUBSTRATE FOR MASK BLANK AND METHOD OF POLISHING FOR PRODUCING THE SAME - The present invention aims at providing a glass substrate required to have a surface polished with extremely high accuracy as in glass substrates for reflective masks for use in EUVL; and a polishing method for producing the glass substrate. The present invention provides a glass substrate for mask blank, which is a glass substrate comprising SiO12-18-2008
20090017257PROCESSING METHOD OF GLASS SUBSTRATE, AND HIGHLY FLAT AND HIGHLY SMOOTH GLASS SUBSTRATE - The present invention is to provide a processing method for manufacturing a highly flat and highly smooth glass substrate with good productivity. A highly flat and highly smooth glass substrate is obtained with good productivity by processing of a glass substrate, which comprises a step of measuring the surface shape of the glass substrate prior to processing, a step of processing the surface of the substrate by changing a processing condition for each site (first processing step), and a step of finish-polishing the surface of the glass substrate that has been subjected to the first processing step (second processing step). At that time, the processing condition for each site within the surface of the substrate in the first processing step is determined from a processing amount that is determined from the concave-convex shape of the surface of the glass substrate prior to processing and the in-plane distribution of a processing amount by the second processing step separately measured by using a similar substrate.01-15-2009
20100048375METHOD FOR POLISHING GLASS SUBSTRATE AND PROCESS FOR PRODUCING GLASS SUBSTRATE - Spots generated on a glass substrate after a polishing step are reduced. The present invention relates to a method for polishing a glass substrate including injecting a silica abrasive and a high-boiling solvent in a final glass substrate polishing step. The high-boiling solvent is preferably a solvent having a molecular weight of 300 or lower and a boiling point of 150° C. or higher. As Examples of the high-boiling solvent having a molecular weight of 300 or lower and a boiling point of 150° C. or higher includes ethylene glycol, propylene glycol and glycerine.02-25-2010
20100075577METHOD OF POLISHING GLASS SUBSTRATE - An object of the present invention is to provide a polishing method for diminishing concave defects of a glass substrate used in a reflective mask for EUVL and the like. The invention relates to a method of polishing a glass substrate which comprises polishing a major surface of the glass substrate while feeding a polishing slurry between the glass substrate and a pad surface of a polishing pad, wherein the polishing load of the polishing pad is from 1 to 60 g/cm03-25-2010
20100080961METHOD OF PROCESSING GLASS SUBSTRATE SURFACE - The present invention is to provide a method for processing the whole of a glass substrate surface so as to give a surface excellent in flatness and surface roughness. The present invention provides a method of processing a glass substrate surface using a processing technique selected from the group consisting of ion-beam etching, gas cluster ion-beam etching, plasma etching, and nano-ablation, wherein a frame element satisfying the following (1) and (2) is arranged along the periphery of the glass substrate before the glass substrate surface is processed: (1) the difference between the height of the frame element and the height of the glass substrate surface is 1 mm or smaller; and (2) the frame element has a width which is not smaller than one-half the beam diameter or laser light diameter to be used in the processing technique.04-01-2010
20100086864METHOD OF POLISHING GLASS SUBSTRATE - The present invention is to provide a method of polishing a glass substrate required to have extremely high surface smoothness and surface accuracy like glass substrates for mask blanks. The invention relates to a method of polishing a glass substrate which comprises polishing the glass substrate with a polishing pad while supplying a polishing slurry comprising an abrasive material and water to the polishing pad, wherein the polishing slurry contains at least one member selected from the group consisting of pullulan and water-soluble alcohols which are polyvalent organic compounds having two or more OH groups. The slurry preferably has a pH adjusted to 0.5-4.04-08-2010
20100101940METHOD FOR REMOVING FOREIGN MATTER FROM GLASS SUBSTRATE SURFACE AND METHOD FOR PROCESSING GLASS SUBSTRATE SURFACE - An object of the invention is to provide a method for removing foreign matter from a glass substrate surface to be finish-processed by a method accompanied with beam irradiation or laser light irradiation on the glass substrate surface. The present invention relates to a method for removing foreign matter from a glass substrate surface, which includes subjecting the glass substrate surface to gas cluster ion beam etching at an accelerating voltage of from 5 to 15 keV.04-29-2010
20100315704OPTICAL COMPONENT FOR EUVL AND SMOOTING METHOD THEREOF - The present invention is to provide a method for smoothing the optical surface having a concave defect of an optical component for EUVL.12-16-2010

Patent applications by Masabumi Ito, Tokyo JP