Abstract: A synthetic quartz glass substrate is prepared by immersing a starting substrate in an aqueous solution of a nonionic surfactant and precision polishing the substrate with a colloidal silica water dispersion. A synthetic quartz glass substrate having a few defects and low surface roughness is obtained while the polishing rate is improved and the polishing time is reduced.

Abstract: A rough surface of a starting synthetic quartz glass substrate is polished to a mirror finish, using a polishing slurry containing tetragonal or cubic zirconia.

Abstract: A synthetic quartz glass substrate has a surface of 6 inch squares including a central surface area of 132 mm squares. The central surface area of 132 mm squares has a flatness of up to 50 nm. A frame region obtained by subtracting the central surface area of 132 mm squares from the central surface area of 148 mm squares has a flatness of up to 150 nm.

Abstract: A synthetic quartz glass substrate is prepared by furnishing a synthetic quartz glass block, coating two opposite surfaces of the block with a liquid having a transmittance of at least 99.0%/mm at the wavelength of birefringence measurement, measuring a birefringence distribution on the block by letting light enter one coated surface and exit the other coated surface, and sorting the block to an acceptable group or unacceptable group, based on the measured birefringence distribution.

Abstract: A rectangular substrate is used as a mold after it is provided with a topological pattern. The substrate has A-side and B-side opposed surfaces, the A-side surface being provided with the topological pattern. The A-side surface includes a central rectangular region of 1 to 50 mm by 1 to 50 mm having a flatness of up to 350 nm. Use of the mold-forming substrate prevents the occurrence of a pattern misalignment or pattern error between the step of forming a pattern on a mold-forming substrate and the transfer step. Transfer of a fine size and complex pattern is possible.

Abstract: Proposed herein is a method for producing substrates, particularly those of synthetic quartz glass, while saving the substrate surface from killer defects without resorting to any large-scale apparatus and precision polishing plate, thereby reducing defectives and improving yields more than in production with conventional facilities. The method for producing substrates by polishing, includes steps of placing substrate stocks individually in work holes formed in a carrier on a lower polishing plate, bringing an upper polishing plate into contact with the surface of the substrate stocks, with the surface of the substrate stocks being coated with an impact-absorbing liquid and the lower polishing plate being rotated, and rotating the upper and lower polishing plates, with the surface of the substrate stocks being accompanied by a polishing slurry.

Abstract: A method for heat treating a synthetic quartz glass having a hydroxyl concentration with a maximum/minimum difference (?OH) of less than 350 ppm involves the steps of first heat treatment of holding at 1,150-1,060° C. for a time of 0.5-10 hours, cooling down to a second heat treatment temperature at a rate of ?7° C./hr to ?30° C./hr, second heat treatment of holding at 1,030-950° C. for a time of 5-20 hours, and annealing at a rate of ?25° C./hr to ?85° C./hr. Two stages of heat treatment ensures that the glass has a low birefringence.

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 method for recovery of cerium oxide from the abrasive waste composed mainly of cerium oxide arising from the polishing of glass substrates, said method including the steps of (i) adding to the abrasive waste an aqueous solution of a basic substance; (ii) adding to the resulting solution a precipitant, thereby forming precipitates composed mainly of cerium oxide, and removing the supernatant liquid; (iii) adding to the resulting precipitates a solution of an acid substance, thereby making said precipitate slightly acid to neutral; (iv) washing the precipitates with an organic solvent; and (v) drying and crushing the precipitates. The method males it possible to recycle abrasive waste into a pure abrasive composed mainly of cerium oxide which can be reused to polish synthetic quartz glass substrates for state-of-the-art semiconductor technology relating to photomasks and reticles.

Abstract: A synthetic quartz glass substrate is prepared by furnishing a synthetic quartz glass block, coating an arbitrary surface and an opposite surface of the block with a liquid having a transmittance of at least 99.0%/mm at the wavelength of birefringence measurement, measuring the birefringence of the block by letting light enter one coated surface and exit the other coated surface, and sorting the block to an acceptable or unacceptable group, based on the measured birefringence value.

Abstract: A method for heat treating a synthetic quartz glass having a hydroxyl concentration with a maximum/minimum difference (?OH) of less than 350 ppm involves the steps of first heat treatment of holding at 1,150-1,060° C. for a time of 0.5-10 hours, cooling down to a second heat treatment temperature at a rate of ?7° C./hr to ?30° C./hr, second heat treatment of holding at 1,030-950° C. for a time of 5-20 hours, and annealing at a rate of ?25° C./hr to ?85° C./hr. Two stages of heat treatment ensures that the glass has a low birefringence.

Abstract: A nanoimprint-mold release agent including an alkoxysilane compound represented by general formula (1) is provided wherein Rf and Rf? are each independently a fluoroalkyl group of 1 to 10 carbon atoms; R1 is a hydrogen atom or an aliphatic monovalent hydrocarbon group of 1 to 6 carbon atoms; R2 and R3 are each independently methyl group or ethyl group; X and Y are each independently an ether linkage or an ester linkage; a and b are each 0 or 1; m, n, and p are each an integer of 0 to 6; q is an integer of 1 to 6 and r is an integer of 0 to 2.

Abstract: A synthetic quartz glass substrate is prepared by immersing a starting substrate in an aqueous solution of a nonionic surfactant and precision polishing the substrate with a colloidal silica water dispersion. A synthetic quartz glass substrate having a few defects and low surface roughness is obtained while the polishing rate is improved and the polishing time is reduced.

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: Disclosed are silazane compounds having two fluoroalkyl groups, represented by the following general formula (1): wherein Rf and Rf? are each a fluoroalkyl group, R1 is a hydrogen atoms or an aliphatic monovalent hydrocarbon group, R2 and R3 are each an aliphatic monovalent hydrocarbon group, R4 is a hydrogen atom or an aliphatic monovalent hydrocarbon group, a and b are each 0 or 1, m, n and p are each an integer of 0 to 6, q is an integer of 1 to 6, and r is 1 or 2. By treating an inorganic material with the silazane compound having two fluoroalkyl groups, high water and oil repellency and high sliding properties can be imparted to the inorganic material in good balance.

Abstract: A polishing composition comprising a colloidal dispersion of spherical silica particles and associated silica particles as abrasive is provided. When used in the step of polishing synthetic quartz glass substrates, the polishing composition ensures a higher polishing rate than conventional colloidal silica and is effective for preventing any microscopic defects on the substrate surface, thus providing the substrate with a high smoothness. The polishing composition can be used as the ceria replacement polishing composition for polishing a lapped surface.

Abstract: A polishing slurry comprising a collagen derivative and a colloidal solution is effective for polishing of synthetic quartz glass substrates. It prevents formation of defects having a size that can be detected by a high-sensitivity flaw detector.

Abstract: A rectangular substrate is used as a mold after it is provided with a topological pattern. The substrate has A-side and B-side opposed surfaces, the A-side surface being provided with the topological pattern. The A-side surface includes a central rectangular region of 1 to 50 mm by 1 to 50 mm having a flatness of up to 350 nm. Use of the mold-forming substrate prevents the occurrence of a pattern misalignment or pattern error between the step of forming a pattern on a mold-forming substrate and the transfer step. Transfer of a fine size and complex pattern is possible.

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.