Abstract: The present invention relates to a silica glass substrate including: a first main surface and a second main surface that are facing each other, in which the silica glass substrate has a density of 2.0 g/cm3 or less, the silica glass substrate includes a plurality of bubbles, the silica glass substrate has an average diameter of first recessed portions of 30 ?m or less, the first recessed portions being formed by the bubbles exposed on the first main surface, and the silica glass substrate has the number of the first recessed portions of 200/mm2 or less on the first main surface.

Abstract: A method of manufacturing a glass substrate having a penetrating structure, the method includes: (1) preparing a glass substrate that has a first surface and a second surface opposite to each other, and includes 3 mol % to 30 mol % of B2O3 in terms of oxide; (2) having the glass substrate irradiated with a laser from a first surface side, to form an initial penetrating structure; (3) wet etching the glass substrate having the initial penetrating structure formed; (4) polishing the wet-etched glass substrate from the first surface side, by using an abrasive including acid-soluble abrasive grains; and (5) cleaning the glass substrate with an acid solution.

Abstract: The present invention provides a detergent for effectively cleaning, by a safe and simple method, a manganese component remaining on and adhered to a substrate surface, after polishing a silicon carbide single crystal substrate with a manganese compound-containing polishing agent. The present invention relates to a detergent for cleaning a silicon carbide single crystal substrate polished with a manganese compound-containing polishing agent, the detergent including at least one of ascorbic acid and erythorbic acid, in which the detergent has a pH of 6 or less.

Abstract: The present invention relates to a polishing slurry including: a colloidal silica having an average particle size of 40 nm or more; water; and a ? potential adjusting component, in which the ? potential adjusting component includes at least one water-soluble organic polymer selected from a water-soluble polyether polyamine and a water-soluble polyalkylene polyamine and at least one acid selected from hydrochloric acid, sulfuric acid, nitric acid, nitrous acid and amidosulfuric acid, and the ? potential adjusting component contains the acid at a ratio of from 0.6 to 1.4 to the water-soluble organic polymer in terms of molar ratio, and the polishing slurry has a pH of 8 or more.

Abstract: The present invention relates to a method for manufacturing a glass substrate for information recording medium, the method including: a lapping step of lapping a circular glass plate made of an alkali aluminosilicate glass; and a subsequent cerium oxide polishing step of polishing the circular glass plate with a slurry containing a cerium oxide abrasive, in which a difference (SiO2?Al2O3) obtained by subtracting an Al2O3 content from an SiO2 content in the alkali aluminosilicate glass is 62% by mole or less; and in which the method further includes: subsequently to the cerium oxide polishing step, a cleaning step of cleaning the circular glass plate with a cleaning liquid having a sulfuric acid concentration of 20% by mass or more and 80% by mass or less and a hydrogen peroxide concentration of 1% by mass or more and 10% by mass or less at a liquid temperature of 50° C. or higher and 100° C.

Abstract: A process for producing a glass substrate for information recording media, comprising lapping a glass disk made of low alkali aluminosilicate glass that contains no alkali metal oxide or contains alkali metal oxides in a total amount of less than 4 mol %, and subsequently polishing the glass disk by using a slurry that contains cerium oxide abrasives, characterized by cleaning the glass disk by using a cleaning liquid that contains sulfuric acid at a concentration of from 20 mass % to 80 mass % and hydrogen peroxide at a concentration of from 0.5 mass % to 10 mass % at a liquid temperature of from 50° C. to 100° C., and thereafter polishing the main surface of the glass disk, by using a slurry that contains colloidal silica abrasives.

Abstract: The present invention relates to a colloidal silica slurry used in a method for manufacturing a glass substrate for an information recording medium, the method including: a lapping step of lapping a main surface of a circular glass plate; a subsequent cerium oxide polishing step of polishing the main surface of the circular glass plate with a slurry containing a cerium oxide abrasive; and a colloidal silica polishing step of polishing the main surface of the circular glass plate with a slurry containing a colloidal silica abrasive after the cerium oxide polishing step, in which the colloidal silica abrasive has a BET average particle size determined by a BET specific surface area measuring method of 40 nm or less, and a smoothness index represented by a ratio (BET average particle size (nm)/Circularity) of the BET average particle size and a circularity indicated by 4·?·S/L2 in which an area per one particle of the colloidal silica abrasive is taken as S and an outer peripheral length thereof is taken as L, o

Abstract: The present invention relates to a polishing slurry including: a colloidal silica having an average particle size of 40 nm or more; water; and a ? potential adjusting component, in which (1) the ? potential adjusting component includes at least one sodium salt selected from the group consisting of sodium nitrate and sodium sulfate, and the polishing slurry has a pH of 8 or more, or (2) the ? potential adjusting component includes at least one water-soluble organic polymer selected from the group consisting of a water-soluble polyether polyamine and a water-soluble polyalkylene polyamine and at least one acid selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, nitrous acid and amidosulfuric acid, and the ? potential adjusting component contains the acid at a ratio of from 0.6 to 1.4 to the water-soluble organic polymer in terms of molar ratio, and the polishing slurry has a pH of 8 or more.

Abstract: The present invention relates to a method for manufacturing a glass substrate for information recording medium, the method including: a lapping step of lapping a circular glass plate made of an alkali aluminosilicate glass; and a subsequent cerium oxide polishing step of polishing the circular glass plate with a slurry containing a cerium oxide abrasive, in which a difference (SiO2?Al2O3) obtained by subtracting an Al2O3 content from an SiO2 content in the alkali aluminosilicate glass is 62% by mole or less; and in which the method further includes: subsequently to the cerium oxide polishing step, a cleaning step of cleaning the circular glass plate with a cleaning liquid having a sulfuric acid concentration of 20% by mass or more and 80% by mass or less and a hydrogen peroxide concentration of 1% by mass or more and 10% by mass or less at a liquid temperature of 50° C. or higher and 100° C.

Abstract: A method for producing a glass substrate for a magnetic disk by polishing a circular glass plate, which comprises a step of polishing the principal plane of the circular glass plate by using a slurry containing a CeO2 crystal powder, the CeO2 crystal powder being obtained in such a manner that a melt containing CeO2 is quenched to obtain an amorphous material, and the amorphous material is subjected to heat treatment to obtain a CeO2 crystals-precipitated amorphous material, which is subjected to acid treatment to separate and extract the CeO2 crystal powder from the CeO2 crystals-precipitated amorphous material.

Abstract: A method for producing a glass substrate for a magnetic disk by polishing a circular glass plate, which comprises a step of polishing the principal plane of the circular glass plate by using a slurry containing at least one water-soluble polymer selected from the group consisting of a water-soluble organic polymer having amino groups, a water-soluble organic polymer having amine salt groups and a water-soluble organic polymer having quaternary ammonium salt groups, and colloidal silica.

Abstract: A method for producing a glass substrate for a magnetic disk by polishing a circular glass plate, which comprises a step of polishing the principal plane of the circular glass plate by using a slurry containing at least one water-soluble polymer selected from the group consisting of a water-soluble organic polymer having amino groups, a water-soluble organic polymer having amine salt groups and a water-soluble organic polymer having quaternary ammonium salt groups, and colloidal silica.

Abstract: A method for producing a glass substrate for a magnetic disk by polishing a circular glass plate, which comprises a step of polishing the principal plane of the circular glass plate by using a slurry containing a CeO2 crystal powder, the CeO2 crystal powder being obtained in such a manner that a melt containing CeO2 is quenched to obtain an amorphous material, and the amorphous material is subjected to heat treatment to obtain a CeO2 crystals-precipitated amorphous material, which is subjected to acid treatment to separate and extract the CeO2 crystal powder from the CeO2 crystals-precipitated amorphous material.

Abstract: To provide a composition for forming a dielectric layer excellent in dielectric constant and withstand voltage properties, a MIM capacitor and a process for its production. A composition for forming a dielectric layer, which comprises fine particles of perovskite type dielectric crystal, glass frit, and a hydrolysable silicon compound or its oligomer, and a MIM capacitor comprising a substrate, and a bottom electrode layer, a dielectric layer having a structure such that fine particles of perovskite type dielectric crystal are dispersed in a silicon oxide matrix containing glass-forming ions and a top electrode, formed on the substrate in this order.

Abstract: To provide a composition for forming a dielectric layer excellent in dielectric constant and withstand voltage properties, a MIM capacitor and a process for its production. A composition for forming a dielectric layer, which comprises fine particles of perovskite type dielectric crystal, glass frit, and a hydrolysable silicon compound or its oligomer, and a MIM capacitor comprising a substrate, and a bottom electrode layer, a dielectric layer having a structure such that fine particles of perovskite type dielectric crystal are dispersed in a silicon oxide matrix containing glass-forming ions and a top electrode, formed on the substrate in this order.