Abstract: In a method of producing a glass substrate for a mask blank, a surface of the glass substrate is polished by the use of an alkaline polishing liquid that contains colloidal silica abrasive grains, from which alkali metal is removed to suppress occurrence of an alkali metal gel substance protrusion adhered on the glass substrate. The polishing process may include a surface roughness control step for initially finishing the surface of the glass substrate to a predetermined surface roughness by moving a polishing member and the glass substrate relative to each other under a predetermined pressure. This may be followed by a protrusion suppressing step under a pressure lower than the predetermined pressure, to minimize polishing rate and suppress occurrence of a fine convex protrusion.

Abstract: A method of producing a glass substrate for a mask blank has the steps of measuring a convex/concave profile of a surface of the glass substrate, controlling a flatness of the surface of the glass substrate to a value not greater than a predetermined reference value by specifying the degree of convexity of a convex portion present on the surface of the glass substrate with reference to a result of measurement obtained in the profile measuring step and executing local machining upon the convex portion under a machining condition depending upon the degree of convexity, and polishing, after the flatness control step, the surface of the glass substrate subjected to the local machining. The surface of the glass substrate subjected to the local machining is subjected to acid treatment after the flatness control step and before the polishing step.

Abstract: In a transparent substrate for a mask blank, which is required to have a predetermined optical characteristic, a substrate mark is formed by cutting off a predetermined corner portion into an oblique section. The shape of the mark is determined in accordance with the optical characteristic of he substrate.

Abstract: In a transparent substrate for a mask blank, which is required to have a predetermined optical characteristic, a substrate mark is formed by cutting off a predetermined corner portion into an oblique section. The shape of the mark is determined in accordance with the optical characteristic of he substrate.

Abstract: In a method of producing a glass substrate for a mask blank, a surface of the glass substrate is polished by the use of a polishing liquid having a pH value between 7.0 and 7.6 that contains abrasive grains, and the abrasive grains include colloidal silica abrasive grains produced by hydrolysis of an organosilicon compound. The polishing process includes a surface roughness control step for initially finishing the surface of the glass substrate to a predetermined surface roughness by moving a polishing member and the glass substrate relative to each other under a predetermined pressure. This is followed by a protrusion suppressing step, carried out immediately before the end of the polishing process, under a pressure lower than the predetermined pressure, to minimize polishing rate and suppress occurrence of a fine convex protrusion. A mask blank and then a transfer mask are formed from this polished glass substrate.

Abstract: A flatness of a substrate is determined to achieve a desired flatness of a mask blank by predicting the variation in flatness resulting from a film stress of a thin film formed on the substrate. The flatness is adjusted by measuring the flatness of the substrate as a measured flatness, selecting a load type with reference to the measured flatness, and polishing the substrate under pressure distribution specified by the load type. A principal surface of the substrate has a flatness greater than 0 ?m and not greater than 0.25 ?m. A polishing apparatus includes a rotatable surface table, a polishing pad formed thereon, abrasive supplying means for supplying an abrasive to the polishing pad, substrate holding means, and substrate pressing means for pressing the substrate. The substrate pressing means has a plurality of pressing members for individually and desirably pressing a plurality of divided regions of the substrate surface.

Abstract: In a method of producing a glass substrate for a mask blank, a surface of the glass substrate is polished by the use of a polishing liquid having a pH value between 7.0 and 7.6 that contains abrasive grains, and the abrasive grains include colloidal silica abrasive grains produced by hydrolysis of an organosilicon compound. The polishing process includes a surface roughness control step for initially finishing the surface of the glass substrate to a predetermined surface roughness by moving a polishing member and the glass substrate relative to each other under a predetermined pressure. This is followed by a protrusion suppressing step, carried out immediately before the end of the polishing process, under a pressure lower than the predetermined pressure, to minimize polishing rate and suppress occurrence of a fine convex protrusion. A mask blank and then a transfer mask are formed from this polished glass substrate.

Abstract: In a transparent substrate for a mask blank, which is required to have a predetermined optical characteristic, a substrate mark is formed by cutting off a predetermined corner portion into an oblique section. The shape of the mark is determined in accordance with the optical characteristic of he substrate.

Abstract: A flatness of a substrate is determined to achieve a desired flatness of a mask blank by predicting the variation in flatness resulting from a film stress of a thin film formed on the substrate. The flatness is adjusted by measuring the flatness of the substrate as a measured flatness, selecting a load type with reference to the measured flatness, and polishing the substrate under pressure distribution specified by the load type. A principal surface of the substrate has a flatness greater than 0 ?m and not greater than 0.25 ?m. A polishing apparatus includes a rotatable surface table, a polishing pad formed thereon, abrasive supplying means for supplying an abrasive to the polishing pad, substrate holding means, and substrate pressing means for pressing the substrate. The substrate pressing means has a plurality of pressing members for individually and desirably pressing a plurality of divided regions of the substrate surface.

Abstract: A flatness of a substrate is determined to achieve a desired flatness of a mask blank by predicting the variation in flatness resulting from a film stress of a thin film formed on the substrate. The flatness is adjusted by measuring the flatness of the substrate as a measured flatness, selecting a load type with reference to the measured flatness, and polishing the substrate under pressure distribution specified by the load type. A principal surface of the substrate has a flatness greater than 0 ?m and not greater than 0.25 ?m. A polishing apparatus includes a rotatable surface table, a polishing pad formed thereon, abrasive supplying means for supplying an abrasive to the polishing pad, substrate holding means, and substrate pressing means for pressing the substrate. The substrate pressing means has a plurality of pressing members for individually and desirably pressing a plurality of divided regions of the substrate surface.

Abstract: A method of producing a glass substrate for a mask blank has the steps of measuring a convex/concave profile of a surface of the glass substrate, controlling a flatness of the surface of the glass substrate to a value not greater than a predetermined reference value by specifying the degree of convexity of a convex portion present on the surface of the glass substrate with reference to a result of measurement obtained in the profile measuring step and executing local machining upon the convex portion under a machining condition depending upon the degree of convexity, and polishing, after the flatness control step, the surface of the glass substrate subjected to the local machining by the action of a machining liquid interposed between the surface of the glass substrate and a surface of a polishing tool without direct contact therebetween.

Abstract: A method of producing a glass substrate for a mask blank has the steps of measuring a convex/concave profile of a surface of the glass substrate, controlling a flatness of the surface of the glass substrate to a value not greater than a predetermined reference value by specifying the degree of convexity of a convex portion present on the surface of the glass substrate with reference to a result of measurement obtained in the profile measuring step and executing local machining upon the convex portion under a machining condition depending upon the degree of convexity, and polishing, after the flatness control step, the surface of the glass substrate subjected to the local machining. The surface of the glass substrate subjected to the local machining is subjected to acid treatment after the flatness control step and before the polishing step.

Abstract: In a method of producing a glass substrate for a mask blank, a surface of the glass substrate is polished by the use of a polishing liquid containing abrasive grains, and the abrasive grains include colloidal silica abrasive grains produced by hydrolysis of an organosilicon compound.

Abstract: A flatness of a substrate is determined to achieve a desired flatness of a mask blank by predicting the variation in flatness resulting from a film stress of a thin film formed on the substrate. The flatness is adjusted by measuring the flatness of the substrate as a measured flatness, selecting a load type with reference to the measured flatness, and polishing the substrate under pressure distribution specified by the load type. A principal surface of the substrate has a flatness greater than 0 &mgr;m and not greater than 0.25 &mgr;m. A polishing apparatus includes a rotatable surface table, a polishing pad formed thereon, abrasive supplying means for supplying an abrasive to the polishing pad, substrate holding means, and substrate pressing means for pressing the substrate. The substrate pressing means has a plurality of pressing members for individually and desirably pressing a plurality of divided regions of the substrate surface.

Abstract: A surface of a silicon carbide film which is an x-ray membrane 12 is made so that the surface roughness thereof may be 1.0 nm or less in terms of Ra (center-line average roughness) and the surface may have no scratch of 0.25 .mu.m or more in width. The surface of the silicon carbide film, which is the x-ray membrane 12 is polished a diamond particle, of a predetermined particle diameter, and colloidal silica dispersed in a solution containing hydrogen peroxide as an abrasive material, so that the surface is highly precise.