Abstract:
A blank made of titanium-doped silica glass for a mirror substrate for use in EUV lithography is provided. The blank includes a surface portion to be provided with a reflective film and having an optically used area (CA) over which a coefficient of thermal expansion (CTE) has a two-dimensional inhomogeneity (dCTE) distribution profile averaged over a thickness of the blank. A maximum inhomogeneity (dCTEmax) of less than 5 ppb/K is defined as a difference between a CTE maximum value and a CTE minimum value. The dCTEmax is at least 0.5 ppb/K. The CA forms a non-circular area having a centroid. The dCTE distribution profile is not rotation-symmetrical and is defined over the CA, such that straight profile sections normalized to a unit length and extending through the centroid of the area yield a dCTE family of curves forming a curve band with a bandwidth of less than 0.5×dCTEmax.
Abstract:
A boron-doped titania-silica glass containing 0.1 wt % to 8.0 wt % boron, 9.0 wt % to 16.0 wt % TiO2, and 76.0 wt % to 90.9 wt % SiO2. The glass may further include F, Nb, Ta, Al, Li, Na, K, Ca, and Mg, individually or in combinations of two or more, at levels up to 4 wt %. The glass may have an OH concentration of more than 10 ppm. The glass features a CTE slope at 20° C. of less than 1 ppb/K2. The fictive temperature of the glass is less than 825° C. and the peak CTE of the glass is less than 30 ppb/K. The glass has two crossover temperatures and a wide temperature interval over which CTE is close to zero. The uniformity of each crossover temperature relative to its average over a volume of at least 50 cm3 is within ±5° C.
Abstract:
Titania-doped quartz glass is manufactured by mixing a silicon-providing reactant gas and a titanium-providing reactant gas, preheating the reactant gas mixture at 200-400° C., and subjecting the mixture to oxidation or flame hydrolysis. A substrate of the glass is free of concave defects having a volume of at least 30,000 nm3 in an effective region of the EUV light-reflecting surface and is suited for use in the EUV lithography.
Abstract:
A blank of TiO2—SiO2 glass for a mirror substrate for use in EUV lithography has a low need for adaptation to optimize the progression of the coefficient of thermal expansion, and consequently also the progression of the zero crossing temperature Tzc. The TiO2—SiO2 glass has at a mean value of the fictive temperature Tf in the range between 920° C. and 970° C. a dependence expressed as the differential quotient dTzc/dTf of its zero crossing temperature Tzc on the fictive temperature Tf of less than 0.3.
Abstract:
A method for manufacturing an SiO2—TiO2 based glass upon a target by a direct method, includes a first process of preheating the target and a second process of growing an SiO2—TiO2 based glass ingot to a predetermined length upon the target which has been preheated, wherein the target is heated in the first process such that, in the second process, the temperature of growing surface of the glass ingot is maintained at or above a predetermined lower limit temperature.
Abstract:
Disclosed is a mask blank substrate for use in lithography, wherein the main surface on which the transfer pattern of the substrate is formed has a root mean square roughness (Rms) of not more than 0.15 nm obtained by measuring an area of 1 μm×1 μm with an atomic force microscope, and has a power spectrum density of not more than 10 nm4 at a spatial frequency of not less than 1 μm−1.
Abstract:
The invention relates to an extra-clear glass sheet, i.e. a glass sheet with high energy transmission, which can be used in particular in the field of solar energy. Specifically, the invention relates to a glass sheet having a composition that includes, in an amount expressed in wt % for the total weight of the glass: 60-78% of SiO2; 0-10% of Al2O3; 0-5% of B2O3; 0-15% of CaO; 0-10% of MgO; 5-20% of Na2O; 0-10% of K2O; 0-5% of BaO, wherein the total amount of iron (in the form of Fe2O3) is 0.002-0.03%, and the composition includes a ratio of manganese/(total iron) of 1 to 8.5, the manganese content being expressed in the form of MnO in wt % relative to the total weight of the glass.
Abstract:
A member is made of titania-doped quartz glass in which striae have a curvature radius of at least 150 mm in a surface perpendicular to an EUV-reflecting surface. The member free of exposed striae and having a high flatness is useful in EUV lithography.
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:
For the production of mirrors for EUV lithography, substrates are suggested having a mean relative thermal longitudinal expansion of no more than 10 ppb across a temperature difference ΔT of 15° C. and a zero-crossing temperature in the range between 20° C. and 40° C. For this purpose, at least one first and one second material having low thermal expansion coefficients and opposite gradients of the relative thermal expansion as a function of temperature are selected and a substrate is produced by mixing and bonding these materials.