Abstract: A silica glass for a radio-frequency device has an OH group concentration being less than or equal to 300 wtppm; an FQ value being higher than or equal to 90,000 GHz at a frequency of higher than or equal to 25 GHz and lower than or equal to 30 GHz; and a slope being greater than or equal to 1,000 in a case where the FQ value is approximated as a linear function of the frequency in a frequency band of higher than or equal to 20 GHz and lower than or equal to 100 GHz.

Abstract: A silica glass for a radio-frequency device has an OH group concentration being less than or equal to 300 wtppm; an FQ value being higher than or equal to 90,000 GHz at a frequency of higher than or equal to 25 GHz and lower than or equal to 30 GHz; and a slope being greater than or equal to 1,000 in a case where the FQ value is approximated as a linear function of the frequency in a frequency band of higher than or equal to 20 GHz and lower than or equal to 100 GHz.

Abstract: The present invention relates to a blank for a nanoimprint mold, comprising a glass substrate and a hard mask layer formed on the glass substrate, wherein the hard mask layer contains chromium (Cr) and nitrogen (N) and has a Cr content of 45 to 95 at %, an N content of 5 to 55 at % and a total content of Cr and N of 95 at % or more and the thickness of the hard mask layer is 1.5 nm or more and less than 5 nm.

Abstract: The present invention relates to a process for production of a TiO2—SiO2 glass body, comprising a step of, when an annealing point of a TiO2—SiO2 glass body after transparent vitrification is taken as T1(° C.), holding the glass body after transparent vitrification in a temperature region of from T1?90(° C.) to T1?220(° C.) for 120 hours or more.

Abstract: The present invention relates to a process for production of a TiO2—SiO2 glass body, comprising: a step of, when an annealing point of a TiO2—SiO2 glass body after transparent vitrification is taken as T1 (° C.), heating the glass body after transparent vitrification at a temperature of T1+400° C. or more for 20 hours or more; and a step of cooling the glass body after the heating step up to T1?400 (° C.) from T1 (° C.) in an average temperature decreasing rate of 10° C./hr or less.

Abstract: A process for producing a porous quartz glass body containing hydrolyzing a metal dopant precursor and an SiO2 precursor in a flame of a burner to form glass fine particles, and depositing and growing the formed glass fine particles on a base material, in which the burner has at least two nozzles, and in which a mixed gas containing (A) a metal dopant precursor gas, (B) an SiO2 precursor gas, (C) one gas of H2 and O2, and (D) one or more gases selected from the group consisting of a rare gas, N2, CO2, a hydrogen halide and H2O, with a proportion of the gas (D) being from 5 to 70 mol %; and (E) the other gas of H2 and O2 of (C), are fed into different nozzles of the burner from each other.

Abstract: A silica glass containing TiO2, which has a fictive temperature of at most 1,200° C., a F concentration of at least 100 ppm and a coefficient of thermal expansion of 0±200 ppb/° C. from 0 to 100° C. A process for producing a silica glass containing TiO2, which comprises a step of forming a porous glass body on a target quartz glass particles obtained by flame hydrolysis of glass-forming materials, a step of obtaining a fluorine-containing porous glass body, a step of obtaining a fluorine-containing vitrified glass body, a step of obtaining a fluorine-containing formed glass body and a step of carrying out annealing treatment.

Abstract: The present invention relates to a TiO2-containing silica glass having a TiO2 content of 7.5 to 12% by mass, a fictive temperature of 1,000° C. or higher, and a temperature at which a coefficient of linear thermal expansion is 0 ppb/° C. being within the range of 40 to 110° C.

Abstract: The present invention relates to a process for production of a TiO2—SiO2 glass body, comprising a step of, when an annealing point of a TiO2—SiO2 glass body after transparent vitrification is taken as T1(° C.), holding the glass body after transparent vitrification in a temperature region of from T1?90(° C.) to T1?220(° C.) for 120 hours or more.

Abstract: The present invention provides a TiO2—SiO2 glass whose coefficient of linear thermal expansion in the range of the time of irradiation with EUV light is substantially zero when used as an optical member of an exposure tool for EUVL and which has extremely high surface smoothness. The present invention relates to a TiO2-containing silica glass having a TiO2 content of from 7.5 to 12% by mass, a temperature at which a coefficient of linear thermal expansion is 0 ppb/° C., falling within the range of from 40 to 110° C., and a standard deviation (?) of a stress level of striae of 0.03 MPa or lower within an area of 30 mm×30 mm in at least one plane.

Abstract: The present invention relates to a process for production of a TiO2—SiO2 glass body, comprising: a step of, when an annealing point of a TiO2—SiO2 glass body after transparent vitrification is taken as T1 (° C.), heating the glass body after transparent vitrification at a temperature of T1+400° C. or more for 20 hours or more; and a step of cooling the glass body after the heating step up to T1?400 (° C.) from T1 (° C.) in an average temperature decreasing rate of 10° C./hr or less.

Abstract: The present invention provides a TiO2—SiO2 glass in which when used as an optical member for an exposure tool for EUVL, a thermal expansion coefficient is substantially zero at the time of irradiation with high-EUV energy light, and physical properties of a multilayer can be kept over a long period of time by releasing hydrogen from the glass. The present invention relates to a TiO2-containing silica glass having a fictive temperature of 1,100° C. or lower, a hydrogen molecule concentration of 1×1016 molecules/cm3 or more, and a temperature, at which a linear thermal expansion coefficient is 0 ppb/° C., falling within the range of from 40 to 110° C.

Abstract: The present invention relates to a process for producing a porous quarts glass body containing hydrolyzing a metal dopant precursor and an SiO2 precursor in a flame of a burner to form glass fine particles, and depositing and growing the formed glass fine particles on a base material, in which the burner has at least two nozzles, and in which a mixed gas containing (A) a metal dopant precursor gas, (B) an SiO2 precursor gas, (C) one gas of H2 and O2, and (D) one or more gases selected from the group consisting of a rare gas, N2, CO2, a hydrogen halide and H2O, with a proportion of the gas (D) being from 5 to 70 mol %; and (E) the other gas of H2 and O2 of (C), are fed into different nozzles of the burner from each other.

Abstract: The present invention is to provide a TiO2—SiO2 glass whose coefficient of linear thermal expansion at the time of irradiating with high EUV energy light becomes substantially zero when used as an optical member of an exposure tool for EUVL. The present invention relates to a TiO2-containing silica glass, having a fictive temperature of 1,000° C. or lower, a OH concentration of 600 ppm or higher, a temperature at which the coefficient of linear thermal expansion becomes 0 ppb/° C. of from 40 to 110° C., and an average coefficient of linear thermal expansion in the temperature range of 20 to 100° C., of 50 ppb/° C. or lower.

Abstract: The present invention provides a TiO2—SiO2 glass whose coefficient of linear thermal expansion upon irradiation with high EUV energy light is substantially zero, which is suitable as an optical member of an exposure tool for EUVL. The present invention relates to a TiO2-containing silica glass having a halogen content of 100 ppm or more; a fictive temperature of 1,100° C. or lower; an average coefficient of linear thermal expansion in the range of from 20 to 100° C. of 30 ppb/° C. or lower; a temperature width ?T, in which a coefficient of linear thermal expansion is 0±5 ppb/° C., of 5° C. or greater; and a temperature, at which a coefficient of linear thermal expansion is 0 ppb/° C., falling within the range of from 30 to 150° C.

Abstract: The present invention is to provide a TiO2—SiO2 glass having suitable thermal expansion properties as an optical member of an exposure tool for EUVL. The present invention relates to a TiO2-containing silica glass having a temperature, at which a coefficient of thermal expansion is 0 ppb/° C., falling within the range of 23±4° C. and a temperature width, in which a coefficient of thermal expansion is 0±5 ppb/° C., of 5° C. or more.

Abstract: An object of the present invention is to provide a TiO2-containing quartz glass substrate which, when used as a mold base for nanoimprint lithography, can form a concavity and convexity pattern having a dimensional variation falling within ±10%. The invention relates to a TiO2-containing quartz glass substrate: in which a coefficient of thermal expansion in the range of from 15 to 35° C. is within ±200 ppb/° C.; a TiO2 concentration is from 4 to 9 wt %; and a TiO2 concentration distribution, in a substrate surface on the side where a transfer pattern is to be formed, is within ±1 wt %.

Abstract: The present invention provides a TiO2—SiO2 glass whose coefficient of linear thermal expansion upon irradiation with high EUV energy light is substantially zero, which is suitable as an optical member of an exposure tool for EUVL. The present invention relates to a TiO2-containing silica glass having a halogen content of 100 ppm or more; a fictive temperature of 1,100° C. or lower; an average coefficient of linear thermal expansion in the range of from 20 to 100° C. of 30 ppb/° C. or lower; a temperature width ?T, in which a coefficient of linear thermal expansion is 0±5 ppb/° C., of 5° C. or greater; and a temperature, at which a coefficient of linear thermal expansion is 0 ppb/° C., falling within the range of from 30 to 150° C.

Abstract: The present invention provides a TiO2—SiO2 glass whose coefficient of linear thermal expansion in the range of the time of irradiation with EUV light is substantially zero when used as an optical member of an exposure tool for EUVL and which has extremely high surface smoothness. The present invention relates to a TiO2-containing silica glass having a TiO2 content of from 7.5 to 12% by mass, a temperature at which a coefficient of linear thermal expansion is 0 ppb/° C., falling within the range of from 40 to 110° C., and a standard deviation (?) of a stress level of striae of 0.03 MPa or lower within an area of 30 mm×30 mm in at least one plane.

Abstract: The present invention provides a TiO2—SiO2 glass in which when used as an optical member for an exposure tool for EUVL, a thermal expansion coefficient is substantially zero at the time of irradiation with high-EUV energy light, and physical properties of a multilayer can be kept over a long period of time by releasing hydrogen from the glass. The present invention relates to a TiO2-containing silica glass having a fictive temperature of 1,100° C. or lower, a hydrogen molecule concentration of 1×1016 molecules/cm3 or more, and a temperature, at which a linear thermal expansion coefficient is 0 ppb/° C., falling within the range of from 40 to 110° C.