EUVL precision parts with specific thermal expansion behavior

Abstract

The present invention relates to EUVL precision components with improved thermal expansion behavior.

Description

[Technical Field]

[0001] The present invention relates to EUVL precision components that exhibit specific thermal expansion behavior.

[0002] Background of the Invention EUV lithography (hereinafter also referred to as EUVL) is a photolithography method that uses electromagnetic radiation, usually between 5 nm and 50 nm (soft X-rays), in particular electromagnetic radiation with a wavelength of 13.5 nm (91.82 eV). This is the so-called "extreme ultraviolet" (EUV). This range of the electromagnetic spectrum is completely absorbed by almost all materials. Therefore, in contrast to DUV lithography (Deep ultraviolet, e.g., 248 nm and / or 193 nm), optically transparent photomasks cannot be used, and reflective multilayer stack systems on low-thermal-expansion photomask substrates (hereinafter also referred to as reticle substrates or mask substrates, English: "Reticle Mask Blank" or "Photo-Mask Blank" or "Mask Blank" or "Substrate") must be used as photomasks (hereinafter also referred to as reticles, reticle masks, or masks, English: "Reticles" or "Reticle Masks" or "Photomasks" or "Masks"). However, the disadvantage of using reflective photomasks is that the maximum reflectivity of the multilayer stack in the EUV radiation range is relatively low, typically less than 70%. Radiation that is not reflected by the photomask is absorbed by the photomask and conducted in the form of heat to the photomask substrate, and in some cases to the photomask support (hereinafter also referred to as the "reticle support" or "reticle stage" or "mask support" or "mask stage", English: "Reticle Stage" or "Photomask Stage" or "Mask Stage"), which can cause its temperature to rise, especially as the exposure time increases.

[0003] However, even slight thermally induced deformation of the photomask can lead to imaging errors on the irradiated wafer and ultimately to yield loss during chip manufacturing. Therefore, to prevent such local deformation or distortion of the photomask substrate, it is necessary to use a material with low thermal expansion or low CTE (Coefficient of Thermal Expansion) for the photomask substrate.

[0004] This is all the more true as the average power of EUV radiation sources used in EUV lithography will increase in the future, for example, by higher repetition rates and / or higher single-pulse energies to improve throughput, which will in turn increase the thermal load on the photomask and possibly even the photomask support. This will increase the importance of active cooling concepts for the photomask and the photomask support, which may further accelerate temperature variations, especially in the photomask and the photomask support. It must also be taken into account that the thermal load on the photomask and the photomask support is not constant but varies due to various factors, particularly inconsistencies in the exposure time due to, for example, loading a new photomask onto the photomask support or downtime due to process stalls. The aforementioned thermally induced deformations can be partially compensated for by compensation mechanisms within the overall optical system of the EUVL lithography apparatus, for example, in beam shaping of the exposure. However, since this compensation is limited, it is desirable to minimize their individual impact on the (imaging) error. Here, not only the thermally induced deformation of the material during exposure must be taken into account, but also its thermal behavior over time (thermal hysteresis). However, materials with relatively high thermal hysteresis make such compensation more difficult, and therefore more difficult to prevent unwanted thermally induced imaging errors in the photomask.

[0005] Furthermore, other EUVL precision components that have high demands on thermal properties include, in particular, the EUVL mirrors in the optical system of the EUVL device and the wafer support (hereinafter also referred to as the "wafer stage") on which the (Si) wafer to be exposed is placed.

[0006] Low thermal expansion or low CTE (Coefficient of Thermal Expansion) materials and precision components are already known from the prior art.

[0007] Known precision component materials with low thermal expansion near room temperature include ceramics, Ti-doped quartz glass, and glass ceramics. Low-thermal expansion glass ceramics are, in particular, lithium aluminum silicate glass ceramics (LAS glass ceramics), as described in, for example, U.S. Pat. Nos. 4,851,372, 5,591,682, EP 587979, 7,226,881, 7,645,714, DE 102004008824, and DE 102018111144. Another precision component material is cordierite ceramic or cordierite glass ceramics.

[0008] Such materials are often used in precision components that must meet particularly stringent requirements regarding their properties (e.g., mechanical, physical, and optical properties). They are used in particular in ground- and space-based astronomy and Earth observation, LCD lithography, microlithography and EUV lithography, metrology, spectroscopy, and measurement techniques. In this case, it is necessary for the components to exhibit particularly low thermal expansion, depending on the specific application.

[0009] Generally, the thermal expansion of materials is measured by a static method, in which the length of a specimen is measured at the beginning and end of a specific temperature range, and the average coefficient of thermal expansion (α) or CTE (Coefficient of Thermal Expansion) is calculated from the difference in these lengths. In this case, the CTE is expressed as the average value for this temperature range, for example, CTE(0;50) or α(0;50) for the temperature range 0°C to 50°C.

[0010] To meet ever-increasing demands, materials have been developed with CTEs more tailored to the application of the components they will be made from. For example, the average CTE can be optimized not only for the standard temperature interval (CTE(0;50)) but also for a temperature interval close to the actual application temperature, e.g., the 19°C to 25°C interval for specific lithography applications, such as EUV lithography, i.e., CTE(19;25). In addition to determining the average CTE, the thermal expansion of the specimen can also be determined over a very small temperature interval and expressed as a CTE-T curve. In particular, such a CTE-T curve can have zero crossings at one or more temperatures, particularly at or near the intended application temperature. At the zero crossings of the CTE-T curve, the relative length change with temperature is particularly small. In some glass-ceramics, the zero crossings of such CTE-T curves can be shifted to the application temperature of the component by appropriate temperature treatment. To minimize the change in length of a part when the temperature changes slightly, it is desirable to minimize not only the absolute value of the CTE but also the slope of the CTE-T curve near the application temperature. Optimization of the CTE or thermal expansion is usually achieved by varying the ceramization conditions for these specific zero-expansion glass-ceramics with the same composition.

[0011] One of the adverse effects in known precision components and materials, particularly in glass ceramics such as LAS glass ceramics, is "thermal hysteresis," hereafter abbreviated as "hysteresis." Hysteresis, as used herein, refers to the fact that the change in length of a specimen when heated at a constant heating rate differs from the change in length of the specimen when subsequently cooled at a constant cooling rate, even if the absolute values ​​of the cooling rate and heating rate are identical. A typical hysteresis loop is obtained by plotting the change in length against the heating or cooling temperature. The shape of the hysteresis loop also depends on the rate of temperature change. The faster the temperature change is performed, the more pronounced the hysteresis effect becomes.The hysteresis effect reveals that the thermal expansion of LAS glass-ceramics depends on temperature and time, i.e., for example, on the rate of change of temperature, and this has already been described in several specialist publications, e.g., O. Lindig and W. Pannhorst, “Thermal expansion and length stability of ZERODUR® in dependence on temperature and time”, APPLIED OPTICS, Vol. 24, No. 20, October 1985; R. Haug et al., “Length variation in ZERODUR® M in the temperature range from −60°C to +100°C”, APPLIED OPTICS, Vol. 28, No. 19, October 1989; R. Jedamzik ​​et al., “Modeling of the thermal expansion behavior of ZERODUR® at arbitrary temperature profiles”, Proc. SPIE Vol. 7739, 2010; D.B. Hall, “Dimensional stability tests over time and temperature for several low-expansion glass ceramics”, APPLIED OPTICS, Vol. 35, No. 10, April 1996.

[0012] Because the length change of glass-ceramics that exhibit thermal hysteresis lags behind or even precedes the temperature change, these materials or precision components made from them exhibit disruptive isothermal length changes, i.e., the material undergoes length changes even after a temperature change, when the temperature is already held constant (so-called "isothermal hold"), and this continues until a steady state is reached. If the material is then heated and cooled again, the same effect occurs again.

[0013] With previously known LAS glass-ceramics, it has not been possible to eliminate the effects of thermal hysteresis while maintaining other properties, even when the ceramization conditions are changed with the same composition.

[0014] The properties of materials, especially glass ceramics, used in precision components, especially EUVL precision components, are often critical in the temperature range of 0°C to 50°C, particularly 10°C to 35°C, or 10°C to 25°C, or 19°C to 25°C, where 22°C is commonly referred to as room temperature. Because many precision components are used in temperatures above 0°C and room temperature, materials with thermal hysteresis effects or isothermal length changes are disadvantageous because they can cause optical disturbances and imaging errors in optical components such as EUVL photomasks, EUVL photomask supports, lithography or EUVL mirrors, EUVL wafer supports, and astronomy or space-based mirrors. This can reduce the measurement accuracy of other precision components made of glass ceramics used in measurement techniques, such as precision scales and interferometer reference plates.

[0015] Several known materials, such as ceramics, Ti-doped silica glass, and some glass-ceramics, have an average coefficient of thermal expansion (CTE) of 0±0.1×10 -6 / K (corresponding to 0±0.1 ppm / K). Materials with such low average CTEs in the aforementioned temperature range are referred to as zero-expansion materials for the purposes of this invention. However, glass-ceramics, particularly LAS glass-ceramics with such optimized average CTEs, typically exhibit thermal hysteresis in the temperature range of 10°C to 35°C. This means that, particularly when used near room temperature (i.e., 22°C), such materials experience detrimental hysteresis effects, which impair the accuracy of precision components manufactured with such materials, especially in EUV lithography. Therefore, glass-ceramic materials that do not exhibit significant hysteresis at room temperature have been developed (see U.S. Pat. No. 4,851,372). However, the effect is not eliminated, merely shifted to lower temperatures. Therefore, these glass-ceramics exhibit significant hysteresis at temperatures below 10°C, which can still be detrimental. This can become even more important when, for example, increased power in EUVL applications requires cooling some EUVL precision components, such as photomask supports or photomasks, to temperatures below room temperature, e.g., about 10°C, about 12°C, about 14°C, about 16°C, or about 18°C. Cooling of EUVL photomasks or photomask supports is described, for example, in EP 1411391, U.S. 2015 / 0241796, and U.S. 20212 / 0026474. Therefore, to characterize the thermal hysteresis of a material over a given temperature range, the present invention considers the thermal behavior of the material at each temperature point within that temperature range. Furthermore, although there are glass-ceramics that do not exhibit significant hysteresis at 22°C and 5°C, these glass-ceramics are not zero-expansion glass-ceramics within the meaning of the above definition because their average CTE(0;50) is greater than 0±0.1 ppm / K.

[0016] Another requirement for glass-ceramic materials is good solubility of the glass components as well as easy melting and homogenization of the base glass melt in large-scale production plants, so that after the subsequent ceramization of the glass, high demands on glass-ceramics or precision components containing glass-ceramics can be met with regard to CTE uniformity, internal quality, in particular low numbers of inclusions (especially bubbles), low striae levels, and polishability.

[0017] It was therefore one of the objectives of the present invention to provide EUVL precision components and glass-ceramics with improved thermal behavior, e.g. with regard to their thermal expansion behavior and / or their thermal hysteresis and / or their CTE uniformity, in particular at application temperatures typical in EUV lithography, in particular at temperatures in the temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, more preferably at least 10°C to 35°C, and even more preferably at or near 22°C.

[0018] Therefore, one of the objectives of the present invention was to provide an EUVL precision part (hereinafter also referred to as precision part) with improved expansion behavior.

[0019] Another object was to provide glass ceramics that can be mass-produced, in particular for EUVL precision components, that have zero expansion and reduced thermal hysteresis, especially in the temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, and particularly preferably at least 10°C to 35°C.

[0020] Another object was to provide glass-ceramics that can be mass-produced, in particular for EUVL precision components, that have zero expansion and reduced thermal hysteresis, in particular in the temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, and particularly preferably at least 10°C to 35°C.

[0021] The above problems are solved by the subject matter of the claims.The invention has various aspects.

[0022] According to one aspect, the present invention provides an EUVL precision component, having an average coefficient of thermal expansion (CTE) of at most 0±0.1×10 in the range of 0 to 50°C. -6 / K, a thermal hysteresis of <0.1 ppm in the temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, particularly preferably at least 10°C to 35°C, and a parameter F of <1.2, where F=TCL(0;50°C) / |Expansion(0;50°C)|.

[0023] According to another aspect, the present invention provides an EUVL precision component, the average coefficient of thermal expansion (CTE) of which is at most 0±0.1×10 in the range of 0 to 50°C. -6 / K, and the thermal hysteresis is less than 0.1 ppm in a temperature range of at least 19 ° C. to 25 ° C., preferably at least 10 ° C. to 25 ° C., particularly preferably at least 10 ° C. to 35 ° C., and the EUVL precision component has an alternative parameter f (20;40) <0.024 ppm / K, alternative parameter f (20;70) <0.039 ppm / K, alternative parameter f (-10;30) <0.015 ppm / K. T.i. and preferably with alternative parameters f (20;40) <0.024 ppm / K for EUVL precision parts.

[0024] According to a further aspect, the present invention relates to an EUVL precision component, having an average coefficient of thermal expansion (CTE) of at most 0±0.1×10 in the range of 0 to 50°C. -6 / K, a thermal hysteresis of <0.1 ppm in the temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, particularly preferably at least 10°C to 35°C, and a parameter F of <1.2, where F = TCL(0;50°C) / |Expansion(0;50°C)|, and the component comprises at least one inorganic material selected from the group consisting of doped quartz glass, glass ceramics and ceramics, in particular Ti-doped quartz glass, LAS glass ceramics and cordierite.

[0025] According to a further aspect, the present invention relates to an EUVL precision component, having an average coefficient of thermal expansion (CTE) of at most 0±0.1×10 in the range of 0 to 50°C. -6 / K, and the thermal hysteresis is less than 0.1 ppm in a temperature range of at least 19 ° C. to 25 ° C., preferably at least 10 ° C. to 25 ° C., particularly preferably at least 10 ° C. to 35 ° C., and the EUVL precision component has an alternative parameter f (20;40) <0.024 ppm / K, alternative parameter f (20;70) <0.039 ppm / K, alternative parameter f (-10;30) <0.015 ppm / K. T.i. and preferably with alternative parameters f (20;40) <0.024 ppm / K and comprising at least one inorganic material selected from the group consisting of doped quartz glass, glass ceramics and ceramics, in particular Ti-doped quartz glass, LAS glass ceramics and cordierite.

[0026] According to a further aspect, the present invention relates to an EUVL precision component, having an average coefficient of thermal expansion (CTE) of at most 0±0.1×10 in the range of 0 to 50°C. -6 / K, a thermal hysteresis of <0.1 ppm in the temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, particularly preferably at least 10°C to 35°C, and a parameter F of <1.2, where F=TCL(0;50°C) / |Expansion(0;50°C)|, wherein the EUVL precision component comprises an LAS glass-ceramic according to the invention.

[0027] According to a further aspect, the present invention relates to an EUVL precision component, having an average coefficient of thermal expansion (CTE) of at most 0±0.1×10 in the range of 0 to 50°C. -6 / K, and the thermal hysteresis is less than 0.1 ppm in a temperature range of at least 19 ° C. to 25 ° C., preferably at least 10 ° C. to 25 ° C., particularly preferably at least 10 ° C. to 35 ° C., and the EUVL precision component has an alternative parameter f (20;40) <0.024 ppm / K, alternative parameter f (20;70) <0.039 ppm / K, alternative parameter f (-10;30) <0.015 ppm / K. T.i. and preferably with alternative parameters f (20;40) <0.024 ppm / K, said EUVL precision part comprising an LAS glass ceramic according to the invention.

[0028] According to a further aspect, the present invention relates to an EUVL precision component according to the invention selected from the group consisting of a photomask or reticle, a photomask substrate or reticle mask blank or mask blanks, a photomask support or reticle stage, a mirror, a mirror support and a wafer support or wafer stage, in particular a photomask or reticle and / or a photomask substrate or reticle mask blank or mask blanks and / or a photomask support or reticle stage.

[0029] According to a further aspect, the present invention relates to a substrate for an EUV (micro)lithography mirror (also called "EUVL mirror") comprising a precision component according to the present invention.

[0030] According to a further aspect, the present invention relates to a substrate for an EUV photomask (also called "(EUVL) photomask blank" or "reticle mask blank") comprising an EUVL precision component according to the present invention.

[0031] According to a further aspect, the present invention relates to an EUV photomask support (also called a "reticle stage") comprising an EUVL precision component according to the present invention.

[0032] According to a further aspect, the present invention relates to a substrate for an EUVL photomask and / or photomask support, which comprises a precision component according to the invention, wherein the precision component has a relative length change (dl / l0) in the temperature range of 20°C to 30°C of ≦|0.10| ppm, preferably ≦|0.09| ppm, particularly preferably ≦|0.08| ppm, and especially preferably ≦|0.07| ppm, and / or a relative length change (dl / l0) in the temperature range of 20°C to 35°C of ≦|0.10| ppm, preferably ≦|0.09| ppm, particularly preferably ≦|0.08| ppm, and especially preferably ≦|0.07| ppm. The relative length change (dl / l0) is ≦|0.17| ppm, preferably ≦|0.15| ppm, particularly preferably ≦|0.13| ppm, and especially preferably ≦|0.11| ppm, and / or the relative length change (dl / l0) in the temperature range from 20°C to 40°C is ≦|0.30| ppm, preferably ≦|0.25| ppm, particularly preferably ≦|0.20| ppm, and especially preferably ≦|0.15| ppm.

[0033] According to a further aspect, the present invention relates to an LAS glass ceramic, in particular for EUVL precision components according to an aspect of the invention, having an average coefficient of thermal expansion CTE in the range of 0 to 50°C of at most 0±0.1 × 10 -6 / K, a thermal hysteresis of <0.1 ppm in a temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, particularly preferably at least 10°C to 35°C, and containing (in mole % on an oxide basis) the following components: SiO260~71 Li2O 7~9.4 MgO+ZnO 0~<0.6 at least one component selected from the group consisting of P2O5, R2O and RO, wherein R2O may be Na2O and / or K2O and / or Cs2O and / or Rb2O, and RO may be CaO and / or BaO and / or SrO; Nucleating agent: 1.5-6 mol % content, where the nucleating agent is TiO 2、 ZrO 2、 At least one component selected from the group consisting of Ta2O5, Nb2O5, SnO2, MoO3, and WO3 The present invention provides a LAS glass-ceramic comprising: [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 shows CTE-T curves of low linear thermal expansion materials, e.g. for precision components, known from the prior art. [Figure 2] Figure 1 shows the hysteresis behavior of three glass-ceramic samples determined using the same method as used in the present invention. This figure is adapted from R. Jedamzik ​​et al., "Modeling of the thermal expansion behavior of ZERODUR® at arbitrary temperature profiles", Proc. SPIE Vol. 7739, 2010. [Figure 3] FIG. 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of known glass-ceramic materials that can be used to manufacture precision components and that exhibit a thermal hysteresis of >0.1 ppm at least in the temperature range of 10-35° C. [Figure 4]FIG. 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of known glass-ceramic materials that can be used to manufacture precision components and that exhibit a thermal hysteresis of >0.1 ppm in at least the temperature range of 15-35° C. [Figure 5] FIG. 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of known glass-ceramic materials that can be used to manufacture precision components and that exhibit a thermal hysteresis of >0.1 ppm in at least the temperature range of 15-35° C. [Figure 6] FIG. 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of known glass-ceramic materials that can be used to manufacture precision components and that exhibit a thermal hysteresis of >0.1 ppm in at least the temperature range of 15-35° C. [Figure 7] FIG. 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of known glass-ceramic materials that can be used to manufacture precision components and that exhibit a thermal hysteresis of >0.1 ppm in at least the temperature range of 15-35° C. [Figure 8] FIG. 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of known glass-ceramic materials that can be used to manufacture precision components and that exhibit a thermal hysteresis of >0.1 ppm in at least the temperature range of 15-35° C. [Figure 9] FIG. 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of prior art glass-ceramics that can be used to manufacture precision components and that exhibit a thermal hysteresis of <0.1 ppm in at least the temperature range of 10-35° C. However, the steep transition of the curve indicates that the glass-ceramics are not zero-expansion. [Figure 10] FIG. 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of a precision part according to the invention or a glass-ceramic according to the invention (composition according to Example 6 of Table 1a) showing a thermal hysteresis of <0.1 ppm at least in the temperature range from 10 to 35° C. [Figure 11] FIG. 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of a precision part according to the invention or a glass-ceramic according to the invention (composition according to Example 7 of Table 1a) showing a thermal hysteresis of <0.1 ppm at least in the temperature range from 10 to 35° C. [Figure 12] 1 shows the normalized Δl / l0-T curve (also called dl / l0 curve) of a precision part according to the invention and advantageously of a glass ceramic (composition according to Example 6 of Table 1a), and an auxiliary line for determining the parameter F as an indicator of the flatness of the expansion curve in the temperature range from 0°C to 50°C. [Figure 13] 1 shows the normalized Δl / l0-T curve (also called dl / l0 curve) of a precision part according to the invention and advantageously of a glass ceramic (composition according to Example 7 of Table 1a), and an auxiliary line for determining the parameter F as an indicator of the flatness of the expansion curve in the temperature range from 0°C to 50°C. [Figure 14] FIG. 1 is a diagram showing a normalized Δl / l0-T curve of a known material that can be used to manufacture a known precision part, and an auxiliary line for determining a parameter F as an index of flatness of the expansion curve in the temperature range of -10°C to 70°C. [Figure 15] FIG. 1 is a diagram showing a normalized Δl / l0-T curve of a known material that can be used to manufacture a known precision part, and an auxiliary line for determining a parameter F as an index of flatness of the expansion curve in the temperature range of −10° C. to 80° C. [Figure 16] FIG. 1 shows a normalized Δl / l0-T curve of a known material that can be used to manufacture a known precision part, and an auxiliary line for determining a parameter F as an index of flatness of the expansion curve in the temperature range of −20° C. to 80° C. [Figure 17] FIG. 1 is a diagram showing a normalized Δl / l0-T curve of a known material that can be used to manufacture a known precision part, and an auxiliary line for determining a parameter F as an index of flatness of the expansion curve in the temperature range of -10°C to 70°C. [Figure 18]FIG. 14 is a diagram showing normalized Δl / l0-T curves of the precision parts or glass ceramics of FIGS. 12 and 13 in the temperature range of −30° C. to +70° C. [Figure 19] FIG. 1 shows normalized Δl / l0-T curves of known materials in the temperature range of −30° C. to +70° C. [Figure 20] FIG. 13 shows that the CTE-T curve of the preferred precision component or preferred glass ceramic of FIG. 12 preferably has a CTE plateau. [Figure 21] FIG. 14 shows that the CTE-T curve of the preferred precision component or preferred glass ceramic of FIG. 13 preferably has a CTE plateau. [Figure 22] FIG. 25 is a diagram showing the slope of the CTE-T curve in FIG. 24. [Figure 23] FIG. 26 is a diagram showing the slope of the CTE-T curve in FIG. 25. [Figure 24] FIG. 1 shows CTE curves of example compositions of the present invention adjusted by ceramization parameters. [Figure 25] FIG. 1 shows CTE curves of example compositions of the present invention adjusted by ceramization parameters. [Figure 26] 1 shows the slope of the CTE-T curve of an advantageous precision component or advantageous glass-ceramic, where the glass-ceramic has a composition according to Example 17 of Table 1a. [Figure 27] 1 shows the normalized Δl / l0-T curve of a precision part according to the invention or of an advantageous glass-ceramic (composition according to Example 17 of Table 1a) and an auxiliary line for determining the alternative parameter f(20;40) as an indicator of the flatness of the expansion curve in the temperature range from 20°C to 40°C. [Figure 28] FIG. 14 shows the normalized Δl / l0-T curve of the precision part or glass ceramic of FIG. 13, and an auxiliary line for determining the alternative parameter f(-10;30) as an index of the flatness of the expansion curve in the temperature range of -10°C to 30°C. [Figure 29]FIG. 14 shows the normalized Δl / l0-T curve of the precision part or glass ceramic of FIG. 13, and an auxiliary line for determining the alternative parameter f(20;70) as an index of the flatness of the expansion curve in the temperature range of 20°C to 70°C. [Figure 30] 1 shows the normalized Δl / l0-T curve of a precision part according to the invention or of an advantageous glass-ceramic (composition according to Example 14 of Table 1a) and an auxiliary line for determining the alternative parameter f(-10;30) as a measure of the flatness of the expansion curve in the temperature range from -10°C to 30°C. [Figure 31] 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of a precision part according to the invention or a glass-ceramic according to the invention (composition according to Example 2b of Table 1b) showing a thermal hysteresis of <0.1 ppm at least in the temperature range from 10 to 35°C. [Figure 32] 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of a precision part according to the invention or a glass-ceramic according to the invention (composition according to Example 6b of Table 1b) showing a thermal hysteresis of <0.1 ppm at least in the temperature range from 10 to 35°C. [Figure 33] 1 shows hysteresis curves (dashed line = cooling curve, dotted line = heating curve) of a precision part according to the invention or a glass-ceramic according to the invention (composition according to Example 7b of Table 1b) showing a thermal hysteresis of <0.1 ppm at least in the temperature range from 10 to 35°C. [Figure 34] 1 shows the normalized Δl / l0-T curve (also called dl / l0 curve) of a precision part according to the invention or of an advantageous glass ceramic (composition according to Example 7b of Table 1b) and an auxiliary line for determining the parameter F as an indicator of the flatness of the expansion curve in the temperature range from 0°C to 50°C. [Figure 35]1 shows another normalized Δl / l0-T curve of a precision part according to the invention based on another ceramization or of an advantageous glass-ceramic (composition according to Example 7b of Table 1b) and an auxiliary line for determining the alternative parameter f(20;70) as an indicator of the flatness of the expansion curve in the temperature range from 20°C to 70°C. [Figure 36] 1 shows the normalized Δl / l0-T curve (also called dl / l0 curve) of a precision part according to the invention or of an advantageous glass-ceramic (composition according to Example 6b of Table 1b) and an auxiliary line for determining the alternative parameter f(-10;30) as an indicator of the flatness of the expansion curve in the temperature range from -10°C to 30°C. [Figure 37] FIG. 1 shows that the CTE-T curve of an advantageous glass-ceramic (composition according to Example 6b in Table 1b) that can be used to manufacture an advantageous precision component or an advantageous EUVL precision component advantageously has a CTE “plateau.” [Figure 38] FIG. 38 is a cross-sectional view of FIG. 37. [Figure 39] FIG. 1 shows that the CTE-T curve of an advantageous glass-ceramic (composition according to Example 7b in Table 1b) that can be used to manufacture an advantageous precision component or an advantageous EUVL precision component advantageously has a CTE “plateau.” [Figure 40] FIG. 40 is a cross-sectional view of FIG. 39. [Figure 41] FIG. 1 shows that the CTE-T curve of an advantageous glass-ceramic (composition according to Example 9b in Table 1b) that can be used to manufacture an advantageous precision component or an advantageous EUVL precision component advantageously has a CTE “plateau.” [Figure 42] FIG. 1 shows the slope of the CTE-T curve of an advantageous precision component or advantageous glass-ceramic having a composition according to Example 6b of Table 1b. [Figure 43] FIG. 1 shows the slope of the CTE-T curve of an advantageous precision component or advantageous glass-ceramic having a composition according to Example 7b of Table 1b. [Figure 44]1 shows the expansion curves of preferred precision components or preferred glass-ceramics having a composition according to Example 6b of Table 1b, adjusted by the ceramization parameters. [Figure 45] 1 shows the expansion curves of preferred precision components or preferred glass-ceramics having a composition according to Example 7b of Table 1b, adjusted by the ceramization parameters.

[0035] First, the EUVL precision component according to the invention and its properties will be described, followed by a description of the LAS glass ceramic according to the invention, which can be used in particular for the production of the EUVL precision component; however, the description of the inventive and advantageous properties of the EUVL precision component also applies to the LAS glass ceramic according to the invention (hereinafter referred to as "glass ceramic" for short) and its advantageous developments.

[0036] Within the scope of the present invention, for the first time, an EUVL precision component is provided that combines several important properties: the average coefficient of thermal expansion (CTE) in the range of 0-50°C is at most 0±0.1×10 -6 / K, i.e., it exhibits zero thermal expansion. Furthermore, the precision part has a thermal hysteresis of <0.1 ppm in the temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, and particularly preferably at least 10°C to 35°C, for a heating rate and cooling rate of 36 K / h, i.e., 0.6 K / min, respectively (see Figures 10 and 11, and Figures 31 to 33). EUVL precision parts having such low hysteresis effects are referred to as hysteresis-free.

[0037] Corresponding precision components having a thermal hysteresis of <0.1 ppm in at least the temperature range of 19°C to 25°C, preferably at least the temperature range of 10°C to 25°C, and therefore being hysteresis-free, can also be advantageously used in other applications, in particular in measurement technology applications that take place at or near room temperature, such as precision scales and positioning systems.

[0038] According to a first variant of the invention, the EUVL precision part further has a parameter F<1.2 for the temperature range 0°C-50°C, where F=TCL(0;50°C) / |Expansion(0;50°C)|, i.e. the expansion curve (i.e. Δl / l0-T curve) shows a flat progression in this temperature range (see, for example, Figures 12, 13, 27 and 34).

[0039] According to a second variant of the invention, the EUVL precision part further comprises an alternative parameter f (20;40) <0.024 ppm / K, alternative parameter f (20;70) <0.039 ppm / K, alternative parameter f (-10;30) <0.015 ppm / K. T.i. (See, for example, FIGS. 27 to 30, 35 and 36).

[0040] CTE The EUVL precision components and glass ceramics according to the present invention exhibit zero thermal expansion, i.e., an average coefficient of thermal expansion (CTE) in the range of 0 to 50°C of at most 0±0.1×10 -6 / K. In some advantageous variations, the average CTE in the range of 0 to 50°C is at most 0±0.05×10 -6 In certain applications, the average CTE over a wider temperature range, for example, from -30°C to +70°C, especially from -40°C to +80°C, can be up to 0±0.1×10 -6 / K, i.e., exhibiting zero expansion.

[0041] To determine the CTE-T curves of the glass ceramics and EUVL precision components according to the present invention and the comparative examples, the differential CTE (T) is first determined. The differential CTE (T) is determined as a function of temperature. The CTE is then determined according to the following equation (1): CTE(T)=(1 / l0)×(∂l / ∂T) (1)

[0042] To create a Δl / l0-T curve or expansion curve or a plot of the change in length Δl / l0 versus temperature of a test specimen (precision part or glass ceramic), the initial length l0 at initial temperature t0 is changed to the length l at temperature t. t The temperature-dependent length change of a specimen can be measured up to 100°C. Here, in particular, a small temperature interval, such as 5°C, 3°C, or 1°C, is selected to determine the measurement points. Such measurements can be performed, for example, by dilatometry, interferometry, e.g., the Fabry-Perot method, i.e., evaluating the shift of the resonance peak of a laser beam incident on the material, or other suitable methods. Within the scope of the present invention, the dilatometry method was selected for determining the CTE on a bar-shaped specimen 100 mm long and 6 mm in diameter, with a temperature interval of 1°C. The method selected for determining the CTE has, in particular, an accuracy of at least ±0.05 ppm / K, preferably at least ±0.03 ppm / K. However, the CTE can, of course, also be determined by a method with an accuracy of at least ±0.01 ppm / K, preferably at least ±0.005 ppm / K, or, according to some embodiments, even at least ±0.003 ppm / K or at least ±0.001 ppm / K.

[0043] From the Δl / l0-T curve, the average CTE for a specific temperature interval, for example, the temperature range of 0°C to 50°C, is calculated.

[0044] The CTE-T curve is obtained by deriving the Δl / l0-T curve. From the CTE-T curve, the zero crossing and the slope of the CTE-T curve within the temperature range can be determined. Based on the CTE-T curve, the shape and location of the advantageous CTE plateau formed in some variations can be determined (see below and Figures 20 and 21, as well as Figures 37, 39, and 41).

[0045] An advantageous embodiment of an EUVL precision component has a high CTE uniformity, where the value of the CTE uniformity (English: "total spatial variation of CTE") is understood to be the so-called peak-to-valley value, i.e. the difference between the highest and lowest CTE values ​​of samples taken from the precision component.

[0046] To determine the CTE uniformity, multiple samples, for example, at least 5, at least 10, at least 20, at least 30, at least 40, or at least 50 samples, are taken from the precision part at each location, and the CTE value for each sample is determined in a predetermined temperature range, for example, the CTE in the temperature range of 0°C to 50°C or the CTE in the temperature range of 19°C to 25°C, in ppb / K, where 1 ppb / K=0.001×10 -6 / K.

[0047] Typically, the thermal expansion or CTE value of the sample is determined by the static method described above, in which the length of the specimen is measured at the start and end of a specific temperature range, and the average coefficient of thermal expansion α or CTE (Coefficient of Thermal Expansion) is calculated from the difference in these lengths. In this case, the CTE is expressed as the average value for this temperature range. For example, the temperature range from 0°C to 50°C is expressed as CTE(0;50) or α(0;50), and the temperature range from 19°C to 25°C is expressed as CTE(19;25).

[0048] Thus, CTE uniformity does not refer to the CTE of the material for a component, but rather to the spatial variation of CTE across the area or precision component. When the CTE uniformity of a component is to be determined over multiple temperature ranges, e.g., 19°C to 25°C and 0°C to 50°C, the CTE uniformity for both temperature ranges can generally be determined on the same sample. However, in this case, it is advantageous to first determine the CTE for the narrower temperature range, e.g., CTE(19;25), and then the CTE for the wider temperature range, e.g., CTE(0;50), for each sample. However, it is particularly advantageous to determine the CTE uniformity of components over different temperature ranges using different samples of those components.

[0049] The CTE uniformity in the temperature range of 0°C to 50°C, i.e., the spatial variation of CTE(0;50), is also referred to as CTE uniformity(0;50) below. CTE uniformity in other temperature ranges can also be referred to similarly. For example, the CTE uniformity in the temperature range of 19°C to 25°C, i.e., the spatial variation of CTE(19;25), is also referred to as CTE uniformity(19;25) below.

[0050] In an advantageous embodiment, the EUVL precision component according to the invention has a CTE uniformity (0;50) across the precision component of at most 5 ppb / K, in particular at most 4 ppb / K, most preferably at most 3 ppb / K and / or a CTE uniformity (19;25) across the precision component of at most 5 ppb / K, in particular at most 4.5 ppb / K, in particular at most 4 ppb / K, even more preferably at most 3.5 ppb / K, even more preferably at most 3 ppb / K, even more preferably at most 2.5 ppb / K. Methods for determining CTE uniformity and means for achieving CTE uniformity are described in WO 2015 / 124710, the disclosure of which is incorporated herein by reference in its entirety.

[0051] Thermal Hysteresis Within the scope of the present invention, EUVL precision components and glass ceramics have a thermal hysteresis of <0.1 ppm over a temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, and particularly preferably at least 10°C to 35°C. Thus, at any temperature within the temperature range of 19°C to 25°C, preferably at least 10°C to 25°C, and particularly preferably at least 10°C to 35°C, the glass ceramic exhibits an isothermal length change of less than 0.1 ppm at a subsequent constant temperature after being subjected to a temperature change. In an advantageous embodiment, this hysteresis-free property exists over a temperature range of at least 5°C to 35°C, particularly at least 5°C to 45°C, and especially at least >0°C to 45°C, preferably at least -5°C to 50°C. In another advantageous embodiment, the temperature range exhibiting the hysteresis-free property is even wider. Preferred application temperatures are in the range of -60 to 100°C, especially -40°C to +80°C. A particular variant of the invention is to use an application temperature T A , or T of 22°C, 40°C, 60°C, 80°C and 100°C A The present invention relates to glass ceramics and EUVL precision components for use in glass ceramics and EUVL precision components for ... A or 22°C T A Glass ceramics and EUVL precision components for automotive applications.

[0052] Thermal hysteresis was determined for the EUVL precision components and glass ceramics according to the invention, as well as for comparative examples, on rod-shaped specimens (i.e., precision component specimens or glass ceramic specimens) with a length of 100 mm and a diameter of 6 mm. The CTE was determined with a precision dilatometer capable of determining the CTE with a reproducibility of ±0.001 ppm / K and ±0.003 ppm / K (absolute value) in a temperature interval of 1°C, according to the method and apparatus configuration disclosed in DE 10 2015 113 548 A1, the disclosure of which is incorporated herein by reference in its entirety. For each tested specimen, the length change Δl / l0 was determined as a function of temperature while cooling from 50°C to -10°C at a cooling rate of 36 K / h. After an isothermal hold time of 5 hours at -10°C, the specimen was heated to 50°C at a heating rate of 36 K / h, and the length change Δl / l0 was recorded as a function of temperature. The thermal hysteresis behavior of the test specimens is investigated at -5°C, 0°C, 5°C, 10°C, 22°C, 35°C, and 40°C. These points are representative of the temperature range from -10°C to 50°C, since in this temperature range the hysteresis decreases with increasing temperature. Thus, a specimen that is hysteresis-free at 22°C or 35°C will also not exhibit hysteresis in the range up to 50°C. Depending on the operating temperature and the materials from which the EUVL precision components are manufactured, further temperature points can be advantageously considered, in particular 19°C and / or 25°C.

[0053] To determine the thermal hysteresis at 10°C, individual measurements of the length change were recorded at five temperatures: 8°C, 9°C, 10°C, 11°C, and 12°C, i.e., two temperature points above and below 10°C, when the sample was heated and cooled at a rate of 36 K / h from -10°C to 50°C. The average value was calculated from the difference between the measurements of the heating and cooling curves for these five temperature points, and this was reported in the table as "Hyst.@10°C" in [ppm].

[0054] To determine the thermal hysteresis at 35°C, the sample was similarly heated and cooled in the range of -10°C to 50°C at a rate of 36 K / h, and individual measurements of the length change were recorded at five temperatures: 33°C, 34°C, 35°C, 36°C, and 37°C, i.e., two temperature points above and below 35°C. The average value was calculated from the difference between the measurements of the heating and cooling curves for these five temperature points, and this was recorded in the table in ppm as "Hyst.@35°C."

[0055] The same procedure was carried out for the other temperature points mentioned above.

[0056] Figures 2 to 8 show thermal hysteresis curves of known materials used in precision components. To allow for better comparison, a range of 6 ppm was always selected on the y-axis for illustration in the figures. The cooling curves (dashed lines) and heating curves (dotted lines) are clearly separated from each other, particularly at low temperatures, i.e., the curves clearly move apart. At 10°C, they are separated by more than 0.1 ppm, and in some comparative examples, by as much as about 1 ppm. Thus, these materials and precision components made therefrom exhibit significant thermal hysteresis at least in the relevant temperature range of 10°C to 35°C.

[0057] In contrast, the EUVL precision components and glass ceramics according to the invention are hysteresis-free not only in the ranges of 19°C to 25°C and 10°C to 35°C, but also advantageously in the range of at least 5°C to 35°C, or at least in the range of 5°C to 45°C, in particular at least in the range of >0°C to 45°C, preferably at least in the temperature range of -5°C to 50°C, preferably also at higher and lower temperatures (see, for example, Figures 10 and 11 and Figures 31 to 33, which are also shown in the range of 6 ppm on the y-axis).

[0058] Parameter F To describe the expansion behavior of a test specimen (precision component or glass ceramic according to the first variant of the invention), the TCL value is often indicated, where TCL stands for "Total Change of Length." In the context of the present invention, the TCL value is indicated in the temperature range of 0 °C to 50 °C. This is determined from the normalized Δl / l0-T curve (also referred to as dl / l0-T curve in the figures) of each test specimen, where "normalized" means that the length change at 0 °C is 0 ppm. The Δl / l0-T curve for determining the TCL is generated in the same way as described above for determining the CTE in the context of the present invention.

[0059] The TCL value is the difference between the highest and lowest dl / l0 values ​​in this temperature range: TCL(0;50℃)=|dl / l0max.|+|dl / l0min.| (2) where "dl" represents the change in length at each temperature, and "l0" represents the length of the test piece at 0°C. When calculating, the absolute values ​​of the dl / l0 values ​​are adjusted.

[0060] Figures 14 to 17 show expansion curves of known materials, from which the maximum and minimum dl / l0 values ​​can be read to calculate the TCL value (see also below). The expansion curves each show a curved progression in the temperature range 0°C to 50°C.

[0061] In contrast, within the scope of the present invention, the flat course of the expansion curve in the temperature range from 0° C. to 50° C. is a further feature of the first variant of the EUVL precision component according to the invention and an advantageous feature of glass ceramics, in particular of glass ceramics for said EUVL precision components. As an expression of the degree to which the course of the thermal expansion curve deviates from a simple linear course, a parameter F, an index of the flatness of the expansion curve, is introduced, which allows for a classification of CTE curves: F = TCL(0;50℃) / |Expansion(0;50℃)| (3)

[0062] The parameter F is calculated by taking the ratio of the TCL(0;50) value (in ppm) (see above) to the difference in expansion (in ppm) between the temperature points 0°C and 50°C. The expansion curves for determining the TCL are, by definition, normalized so that the length change at 0°C is 0 ppm, so the "difference in expansion between the temperature points 0°C and 50°C" corresponds to the "expansion at 50°C" given in the table. The absolute value of the expansion at 50°C is used to calculate the parameter F.

[0063] Here, it is advantageous if the parameter F is <1.2, preferably <1.1, preferably at most 1.05. The closer the parameter F is to 1, the flatter the progression of the expansion curve.

[0064] FIG. 12 illustrates the expansion curve of a precision component or glass-ceramic based on the preferred ceramization of Composition Example 6 according to the present invention. For illustration purposes, a 1.6 ppm zone was selected on the y-axis. The maximum expansion value (dl / l0 max.) is at +50°C (dl / l0 is +0.57 ppm, i.e., |0.57 ppm|), and the minimum expansion value (dl / l0 min.) is 0 ppm. The expansion difference between the temperatures of 0°C and 50°C, which corresponds to the absolute value of "expansion at 50°C," is 0.57 ppm. From this, the parameter F of this material is calculated as follows: F (Example 6 in Table 1a) = 0.57 ppm / 0.57 ppm = 1.

[0065] FIG. 13 shows a further example of the invention (a composition according to Example 7 of Table 1a), in which the parameter F is also 1.

[0066] FIG. 34 illustrates the expansion curve of a further precision component or advantageous glass-ceramic based on the advantageous ceramization of Example 7b (maximum temperature 830°C, duration 3 days). For illustration purposes, a 2.4 ppm zone was selected on the y-axis. The maximum expansion value (dl / l0max.) is at +50°C (dl / l0 is +0.57 ppm, i.e., |0.57 ppm|), and the minimum expansion value (dl / l0min.) is 0 ppm. The expansion difference between the temperature points of 0°C and 50°C, which corresponds to the absolute value of "expansion at 50°C," is 0.57 ppm. From this, the parameter F of this material is calculated as follows: F (Example 7b in Table 1b) = 0.57 ppm / 0.57 ppm = 1.

[0067] FIG. 35 shows the advantageously flat progression of the expansion curve in the temperature range from -10°C to 80°C for another precision part or glass ceramic that has been subjected to another ceramization of the glass ceramic of Example 7b of Table 1b (maximum temperature 825°C, duration 3 days).

[0068] Thus, the EUVL precision component of the first variant of the invention and the preferred glass-ceramic exhibit a very flat progression of its expansion curve in the temperature range from 0°C to 50°C, i.e., not only is it zero-expansion in this temperature range, but also the variation in the change in linear expansion, and thus in the differential CTE, is small in this range. As can be seen in Figure 18, the preferred embodiment of the invention also exhibits a flat progression of its expansion curve over an even wider temperature range (here, exemplarily, from -30°C to +70°C). See, by comparison, the much steeper progression of the expansion curve of the known material for the same temperature range in Figure 19.

[0069] In comparison with the preferred EUVL precision components and glass ceramics according to the present invention, Figures 14 to 17 show the expansion behavior of known materials and EUVL precision components made therefrom, from which the parameter F can be calculated, respectively. The expansion behavior of the materials or EUVL precision components shown in Figures 14 to 17 and 19 was measured using the same dilatometer under conditions equivalent to those of the EUVL precision components and glass ceramics according to the present invention shown in, for example, Figures 12, 13, 18, 27 to 30, and 34 to 36. Generally, the known materials exhibit curved progressions in the expansion curves.

[0070] Figure 14 shows the expansion curve of a commercially available titanium-doped silica glass in the same dl / l0 region as shown in Figures 34-36. As can be seen, the absolute value of the expansion at +50°C (dl / l0 max. is +0.73 ppm, i.e., |0.73 ppm|) plus the absolute value of the expansion at 14°C (dl / l0 min. is -0.19 ppm, i.e., |0.19 ppm|) gives a TCL(0;50) value of approximately 0.92 ppm. The expansion difference between the 0°C and 50°C temperatures, corresponding to the absolute value of "expansion at 50°C," is 0.73 ppm. From this, the parameter F of this material is calculated as follows: F(Ti-doped SiO2) = 0.92 ppm / 0.73 ppm = 1.26.

[0071] Similarly, the parameter F of the known LAS glass ceramic or the corresponding precision part (see FIG. 15) is calculated as follows: F(known LAS glass ceramic)=1.19 ppm / 0.11 ppm=10.82.

[0072] Similarly, the parameter F of the known cordierite glass ceramic or the corresponding precision part (see FIG. 16) is calculated as follows: F(known cordierite glass ceramic)=2.25 ppm / 0.25 ppm=9.

[0073] Similarly, the parameter F of the known sintered cordierite ceramic or the corresponding precision part (see FIG. 17) is calculated as follows: F(known sintered cordierite ceramic)=4.2 ppm / 2.71 ppm=1.55.

[0074] The EUVL precision components and advantageous glass ceramics according to the invention, which exhibit a flat progression of the expansion curve, are highly advantageous because the components can be optimized not only for the subsequent application temperature, but also exhibit low thermal expansion, for example, at higher and / or lower temperature loads, for example, during production. Precision components for microlithography, EUV (extreme UV) lithography or microlithography (also referred to as "EUV lithography" or "EUVL" for short) and metrology are usually used in standard cleanroom conditions, in particular at room temperature of 22°C. The CTE can be adapted to this application temperature. However, such components are subjected to various process steps, such as, for example, coating with metal layers, cleaning steps, structuring steps and / or exposure steps, during which temperatures higher or possibly lower than those present during subsequent use in the cleanroom may be present. Furthermore, when using EUVL components, the typical T of 22°C is also used. A, higher or lower temperatures than the above may occur, for example, when the photomask is irradiated with EUVL radiation and / or when the photomask and / or the photomask support is heated, or when the photomask and / or the photomask support is cooled. Therefore, EUVL precision components and advantageous glass-ceramics according to the invention, which have a parameter F of <1.2 and thus exhibit optimized zero expansion not only at the application temperature but also, possibly, at the high and / or low temperatures during production, are highly advantageous. Properties such as hysteresis-freeness and a parameter F of <1.2 are particularly advantageous because the EUVL precision component or glass-ceramic is used in EUV lithography, i.e., when the precision component is, for example, an EUV lithography mirror (also referred to as "EUVL mirror" for short) or an EUVL photomask or a corresponding substrate or photomask support, because in EUV lithography, the mirror, photomask, or photomask support, in particular, is heated very non-uniformly in a point-wise or radial direction by the irradiation of high-energy radiation. In the case of photomasks, heat dissipation to the photomask support can also be a source of heat generation. Under these conditions, it is advantageous for EUVL precision components or glass ceramics to have a low slope of the CTE-T curve in the temperature range around the application temperature (see below).

[0075] Advantageous EUVL precision components and advantageous glass ceramics of the first variant, in particular advantageous glass ceramics for EUVL precision components of the first variant, which are even better optimized for application temperatures in the range of 20°C to 25°C, for example 20 or 22°C at a later time, are characterized by a relative length change (dl / l0) in the temperature range of 20°C to 30°C of |0.10| ppm or less, preferably |0.09| ppm or less, particularly preferably |0.08| ppm or less, and very particularly preferably |0.07| ppm or less and / or a relative length change (dl / l0) in the temperature range of 20°C to 35°C of |0.17| ppm or less, preferably |0.15| ppm or less, particularly preferably |0.13| ppm or less, and very particularly preferably |0.11| ppm or less. Alternatively or additionally, the glass ceramics and precision components thus optimized can be characterized by a relative length change (dl / l0) of |0.30| ppm or less, preferably |0.25| ppm or less, particularly preferably |0.20| ppm or less, and especially preferably |0.15| ppm or less in the temperature range from 20°C to 40°C. The characteristics of the relative length change for each temperature range can be read, in particular, from the dl / l0 curves, for example, in Figures 12 to 19. When referring to the relative length change (dl / l0), these data naturally relate to the absolute value of the respective value.

[0076] Zero-expansion, hysteresis-free EUVL precision components exhibiting such advantageous expansion behavior are particularly suitable for use as EUVL mirrors or EUVL mirror substrates, which are heated to different degrees in light and shadow areas during operation, for example due to the respective exposure mask. Zero-expansion, hysteresis-free EUVL precision components exhibiting such advantageous expansion behavior are likewise particularly suitable for use as EUVL photomask substrates and / or photomask supports, which are heated to different intensities during operation. Due to the above-mentioned small relative length changes, the described EUVL precision components formed from advantageous glass-ceramics have smaller local gradients (local slopes or local tilts) in their surface topography than corresponding EUVL precision components made from known materials.

[0077] The present invention further relates to an EUVL photomask substrate and an EUVL photomask support comprising a precision component according to the present invention, wherein the mirror has an advantageous relative length change as described above.

[0078] Alternative parameter f T.i. The EUVL precision component according to the second variant of the invention, and in particular the preferred glass-ceramics for such a precision component, is characterized by the alternative parameter f T.i. It is characterized by:

[0079] To explain the expansion behavior of the test specimens (precision components or glass ceramics), the TCL according to the second variant of the EUVL precision components and the preferred glass ceramics was used. (T.i.) Values ​​are shown, where TCL stands for "Total Change of Length" and Ti represents the respective temperature interval.

[0080] Alternative parameter f T.i. The expansion behavior can be investigated in the temperature interval (Ti), in particular in the temperature ranges (20;40), (20;70) and / or (-10;30), thereby allowing the expansion behavior to be better classified in terms of the application area at a later time. In particular, in the case of EUVL precision components made of glass ceramics, whose expansion curves show a very flat progression in the temperature range in question and fluctuate around or at 0 ppm (see, for example, Figures 35 and 36) - which is an overall advantageous expansion behavior - it may be advantageous to introduce a further indicator of the flatness of the expansion curve instead of or in addition to the parameter F.

[0081] Alternative parameter f T.i. has units (ppm / K) and is as follows: f T.i. =TCL (T.i.) / Temperature range (Ti) width (4) where Ti represents the respective temperature interval.

[0082] TCL (T.i.) The value is the difference between the maximum and minimum dl / l0 values ​​in each temperature range (Ti), where the expansion curve is (T.i.) The calculation is also normalized so that the length change at 0°C is 0 ppm, according to the definition. So, for example: TCL (20;40℃) =|dl / l0max.|+|dl / l0min.| (5) where "dl" represents the change in length at each temperature, and "l0" represents the length of the specimen at 0°C. If the curve fluctuates around zero in the temperature range (e.g., Figures 30, 35, and 36), the absolute value of the dl / l0 value is used for calculation. Otherwise, the TCL (T.i.) is the interval calculated from the difference between the maximum and minimum dl / l0 values ​​in each temperature interval (Ti), which is self-evident and can be seen in the figures (e.g., Figures 27 and 29). (T.i.) can be calculated as follows: TCL (T.i.) = dl / l0max.-dl / l0min. (6)

[0083] Alternative parameter f T.i. is expressed as TCL according to equation (4). (T.i.) It is calculated by calculating the ratio of the value [in ppm] (see above) to the width, in [K], of the temperature interval (Ti) in which the expansion difference is considered. The width of this temperature interval, from 20°C to 40°C, is 20 K. On the other hand, if we consider the progression of the expansion curve in the interval Ti = (20; 70) or (-10; 30), the denominator of equation (4) is 50 K or 40 K.

[0084] The EUVL precision component according to the invention and the advantageous glass ceramics, whose expansion curves show a very flat course, are very advantageous, since the EUVL precision component can now be optimized not only for the application temperature at a later time, but also for example for higher and / or lower temperature loads that can be expected. T.i. is suitable for defining suitable materials according to the specifications required for a particular component application and for providing corresponding EUVL precision components. Specific precision components and their applications are described below and included herein.

[0085] The EUVL precision component or advantageous glass ceramic of the second variant according to the invention has an alternative parameter f (20;40) may be less than 0.024 ppm / K, preferably less than 0.020 ppm / K, preferably less than 0.015 ppm / K. Hysteresis-free zero-expansion components or glass-ceramics that exhibit such expansion behavior in the temperature range (20;40) can be particularly well used at room temperature as EUVL precision components. Examples of such precision components and advantageous glass-ceramics are shown in FIG. 27 and can also be seen, for example, in FIG. 35.

[0086] The EUVL precision component or advantageous glass ceramic of the second variant according to the invention has an alternative parameter f (20;70)The thermal expansion coefficient (Tc) of the EUVL precision component can be less than 0.039 ppm / K, preferably less than 0.035 ppm / K, preferably less than 0.030 ppm / K, preferably less than 0.025 ppm / K, preferably less than 0.020 ppm / K. Hysteresis-free, zero-expansion components or glass ceramics exhibiting such expansion behavior in the temperature range (20;70) can also be particularly well suited for use as EUVL precision components. It is particularly advantageous if the component also exhibits low thermal expansion when subjected to higher temperature loads, which can occur, for example, locally or over a wide area, during the manufacture of the EUVL precision component as well as during operation. Further details of the temperature loads occurring in EUVL precision components have already been given above in connection with the parameter F, and reference will now be made to this parameter F to avoid repetition. An example of such a precision component and an advantageous glass ceramic is shown in FIG. 29 and also in FIG. 35.

[0087] The EUVL precision component or advantageous glass ceramic of the second variant according to the invention has an alternative parameter f (-10;30) The expansion coefficient may be less than 0.015 ppm / K, preferably less than 0.013 ppm / K, preferably less than 0.011 ppm / K. Hysteresis-free, zero-expansion components or glass-ceramics exhibiting such expansion behavior in the temperature range (-10; 30) are particularly well suited for use as precision components, in particular as mirror substrates for applications where temperatures below room temperature may occur, such as in astronomy or Earth observation from outer space, and in EUVL photomasks or EUVL photomask supports, which are particularly cooled in the context of the present application. Corresponding components are described below. Examples of such precision components and advantageous glass-ceramics are shown in FIGS. 28 and 30 and also in FIG. 36.

[0088] A particularly advantageous embodiment of the EUVL precision component or glass ceramic is characterized by the fact that at least two alternative parameters f (T.i.) It has.

[0089] A particularly advantageous embodiment of the precision component or glass ceramic comprises a parameter F and at least one alternative parameter f (T.i.) and

[0090] Further advantageous features Some advantageous EUVL precision components and glass ceramics also have so-called CTE plateaus (see Figures 20 and 21, and Figures 37, 39 and 41).

[0091] The differential CTE has a plateau close to 0 ppm / K, i.e., a temperature range T P It is advantageous if the differential CTE is less than 0±0.025 ppm / K at T P It is called.

[0092] A CTE plateau is therefore understood to be the range extending over the section of the CTE-T curve where the differential CTE does not exceed 0±0.025 ppm / K, in particular 0±0.015 ppm / K, more preferably 0±0.010 ppm / K, even more preferably 0±0.005 ppm / K, i.e., a CTE value around 0 ppb / K.

[0093] A temperature interval T with a width of at least 40 K P In some cases, it may be advantageous for the differential CTE to be less than 0±0.015 ppm / K, i.e., less than 0±15 ppb / K. In a preferred embodiment, a CTE plateau of 0±0.01 ppm / K, i.e., 0±10 ppb / K, may be formed over a temperature interval of at least 50 K. In Figure 25, the middle curve even shows a CTE plateau of 0±0.005 ppm / K, i.e., 0±5 ppb / K, between 7°C and 50°C, i.e., over a range of more than 40 K.

[0094] Temperature interval T P It may be advantageous if the temperature is in the range of -10 to +100°C, particularly 0 to 80°C.

[0095] The position of the CTE plateau is particularly important for precision components at the application temperature T A The preferred application temperature of precision parts is T A is in the range of -60°C to +100°C, more preferably -40°C to +80°C. Particular variations of the invention are applicable to application temperatures T of 0°C, 5°C, 10°C, 22°C, 40°C, 60°C, 80°C and 100°C. A , preferably at a T of 22°C A or T in a temperature range of 10°C to 35°C, preferably 10°C to 25°C, and more preferably 19°C to 25°C. A CTE plateau, i.e., temperature range T p The curve range with small deviations of the differential CTE at can be in the temperature ranges of [-10; 100]; [0; 80], [0; 30°C], [10; 40°C], [20; 50°C], [30; 60°C], [40; 70°C] and / or [50; 80°C]. In further advantageous EUVL precision components or glass-ceramics, the CTE plateau can also be in the temperature ranges of [-10; 30], [0; 50], [10; 25°C], [19; 25°C]; [20; 40] and / or [20; 70].

[0096] Figure 37, based on Example 6b in Table 1b, shows that this precision part or glass-ceramic has a CTE of 0±0.010 ppm / K, i.e., a 10 ppb plateau, over the entire temperature range shown, from -10° C. to 90° C. A closer look at a section of this curve (see Figure 38) reveals that the glass-ceramic has a CTE of 0±0.005 ppm / K over the temperature range of -5° C. to 32° C.

[0097] This glass-ceramic meets the average CTE(19;25) requirements set out in standard SEMI P37-1109 for EUVL substrates and blanks.

[0098] Figure 39 shows that for Example 7b of Table 1b, which was ceramized for 3 days at temperatures up to 825°C, the precision part or glass-ceramic has a CTE of 0±0.010 ppm / K from 12°C, i.e., a 10 ppb plateau with a width of more than 40 K. As can be seen in Figure 40, the example in the range of 16°C to 40°C even has a CTE of 0±0.005 ppm / K, thus also meeting the average CTE(19;25) requirement set out in standard SEMI P37-1109 for EUVL substrates and blanks.

[0099] FIG. 41 shows that for Example 9b of Table 1b, which was ceramized at temperatures up to 830°C for 3 days, the precision part or glass-ceramic has a CTE of 0±0.010 ppm / K, i.e., a 10 ppb plateau, over the indicated temperature range of -5°C to 45°C.

[0100] EUVL precision components and glass ceramics with a plateau, i.e., optimized zero expansion, are characterized by a flat progression of the expansion curve and a zero expansion coefficient of the parameter F or alternatively the parameter f T.i. provides the same advantages as already mentioned above in connection with

[0101] According to an advantageous embodiment of the invention, the CTE-T curve of the EUVL precision component or glass ceramic has at least one curve section with a small slope in a temperature range having a width of at least 30 K, in particular a width of at least 40 K, more preferably a width of at least 50 K, in particular a slope of at most 0±2.5 ppb / K. 2 , advantageously at most 0±2 ppb / K 2 , advantageously at most 0±1.5 ppb / K 2 , especially up to 0±1 ppb / K 2 , especially up to 0±0.8 ppb / K 2 , and according to certain variants even up to only 0±0.5 ppb / K 2 is.

[0102] The temperature range with a small slope is especially suitable for EUVL precision parts.A The preferred application temperature of precision parts is T A The T ranges from -60°C to +100°C, more preferably from -40°C to +80°C. A particular variant of the invention is directed to application temperatures in the range of 10 to 35°C, preferably 10 to 25°C, and even more preferably 19 to 25°C, as well as T ranges of 0°C, 5°C, 10°C, 22°C, 40°C, 60°C, 80°C and 100°C. A The temperature range with a small slope can be in the temperature ranges of [-10; 100], [0; 80], [0; 30°C], [10; 40°C], [20; 50°C], [30; 60°C], [40; 70°C], [10; 25°C], [19; 25°C] and / or [50; 80°C]. In further advantageous precision parts or glass ceramics, the temperature range with a small slope can be in the temperature ranges of [-10; 30], [0; 50], [10; 25°C], [19; 25°C], [20; 40] and / or [20; 70].

[0103] FIG. 22 shows the slope of the CTE-T curve for an advantageous EUVL precision component or glass-ceramic based on the composition of Example 6 in Table 1a in the temperature range of 0° C. to 45° C. The slope of the CTE is 0±2.5 ppb / K over the entire temperature range. 2 and 0±1.5 ppb / K over an interval of at least 30K. 2 is less than.

[0104] In FIG. 23, the CTE slope of the advantageous EUVL precision component or glass ceramic corresponding to Composition Example 7 in Table 1a is 0±1.0 ppb / K over the entire temperature range of 0°C to 40°C, which is at least 40K wide. 2 and 0±0.5 ppb / K over an interval of at least 30 K. 2 It can be seen that it is less than

[0105] In FIG. 26, the CTE slope of the advantageous EUVL precision component or glass ceramic corresponding to Example 17 in Table 1a is 0±1.0 ppb / K over the entire temperature range of 0° C. to 45° C., with a width of at least 45 K. 2and 0±0.5 ppb / K over an interval of at least 30 K. 2 It can be seen that it is less than

[0106] FIG. 42 shows the slope of the CTE-T curve for the advantageous EUVL precision component or glass-ceramic based on the composition of Example 6b in Table 1b in the temperature range of 0° C. to 45° C. The slope of the CTE is 0±1 ppb / K over the entire temperature range. 2 and even less than 0±0.5 ppb / K over an interval of at least 30 K (from about 12°C). 2 is less than.

[0107] In FIG. 43, the CTE slope of the advantageous precision component or glass ceramic corresponding to Example 7b in Table 1b is 0±1.0 ppb / K over the entire temperature range of 0° C. to 45° C., which is at least 45 K wide. 2 and even less than 0±0.5 ppb / K over an interval of at least 40 K (in the range of 0 to 42°C shown). 2 It can be seen that it is less than

[0108] Glass ceramics and precision components exhibiting such expansion behavior are particularly well suited for EUV lithography applications (e.g. as mirrors or substrates for mirrors or masks or mask blanks, or as photomask supports or wafer supports), since in this field increasingly high demands are placed on the materials and precision components used in optical components with regard to extremely low thermal expansion, zero crossings of the CTE-T curve near the application temperature, and in particular a small slope of the CTE-T curve. Advantageous embodiments of EUVL precision components or glass ceramics within the scope of the present invention exhibit a very flat CTE profile, which in addition to the zero crossings also exhibits a very small CTE slope and possibly also a very flat plateau.

[0109] The low slope feature can be present with or without the formation of a favorable CTE plateau.

[0110] 24 and 25 show how the CTE profile can be adapted to various application temperatures by varying the ceramization temperature and / or ceramization time. As can be seen in FIG. 24, increasing the ceramization temperature by 10 K can shift the zero crossing of the CTE-T curve, for example, from 12°C to 22°C. Instead of increasing the ceramization temperature, the ceramization time can be appropriately extended. FIG. 25 exemplarily illustrates that increasing the ceramization temperature by, for example, 5 K or 10 K can increase the very flat profile of the CTE-T curve. Instead of increasing the ceramization temperature, the ceramization time can be appropriately extended.

[0111] Figures 44 and 45 show how the expansion curves can be adapted to different application temperatures by varying the ceramization temperature and / or ceramization time.

[0112] Figure 44, based on Example 6b in Table 1b, shows that the expansion curve of the resulting precision component or glass-ceramic can be targeted by selecting the maximum ceramizing temperature for the initial green glass. The dotted curve shows the expansion curve of a glass-ceramic obtained by ceramizing the base green glass at up to 810°C for 2.5 days, while the dashed curve shows the expansion curve of a glass-ceramic obtained by ceramizing the base green glass at up to 820°C for 2.5 days. Furthermore, Figure 44 illustrates that glass-ceramics according to the present invention can be re-ceramized, i.e., the expansion curve of a glass-ceramic can be targetedly fine-tuned by subjecting an already ceramized material to a new temperature treatment. In this case, the glass-ceramic material ceramized at up to 810°C for 2.5 days was further re-ceramized at 810°C for 1.25 days, i.e., a shorter holding time. The effect of this re-ceramization is shown in the form of the dashed expansion curve. Comparison of the expansion curves shows that the expansion curves, and therefore the average CTE(0;50), are different before and after re-ceramization. However, XRD analysis of the samples before and after re-ceramization revealed identical results, within the limits of measurement accuracy, in terms of average crystallite size and percentage of crystalline phase.

[0113] Figure 45 shows the tunability of the expansion curve over different maximum ceramization temperatures for Example 7b in Table 1b when ceramizing the same initial green glass. The dashed line indicates ceramization up to 830°C for 3 days, and the dotted line indicates ceramization up to 825°C for 3 days.

[0114] Instead of increasing the ceramization temperature, the ceramization time can be appropriately extended.

[0115] Advantageous EUVL precision components and glass ceramics also have good internal quality. In particular, they are suitable for 100 cm 3A maximum of 5 inclusions per 100cm² is preferred. 3 Maximum of 3 inclusions per 100cm, most preferably 3 According to the invention, inclusions are understood to mean both bubbles and crystallites with a diameter of more than 0.3 mm.

[0116] According to one variant of the invention, the diameter or side length is at most 800 mm, the thickness is at most 250 or 100 mm, and the inclusions with a diameter greater than 0.03 mm are each 100 cm 3 At most 5, in particular at most 3, more preferably at most 1 EUVL precision part per wafer, such as photomask substrates, photomask supports, EUVL mirrors and / or wafer stages are provided.

[0117] In addition to the number of inclusions, the maximum diameter of the detected inclusions also serves as an indicator of the internal quality grade. The maximum diameter of individual inclusions in the total volume of precision parts with a diameter or side length of less than 500 mm is in particular 0.6 mm, and in application-critical volumes, for example near the surface, in particular 0.4 mm.

[0118] The maximum diameter of individual inclusions in glass-ceramic components with a diameter of 500 mm to less than 2 m or a side length of 500 mm to less than 2 m is, in particular, at most 3 mm, and in application-relevant volumes, for example near the surface, at most 1 mm, which may be advantageous for achieving the surface quality required for the application.

[0119] One embodiment relates to an EUVL precision component having small dimensions, in particular a side length (width and / or depth) in the case of a polygon (rectangle) or a diameter in the case of a circular surface of at least 50 mm, preferably at least 100 mm and / or at most 1500 mm, preferably at most 1000 mm, and / or a thickness of less than 50 mm, in particular less than 10 mm and / or at least 1 mm, more preferably at least 2 mm. Such precision components can be used, for example, in microlithography and EUV lithography, for example as photomask substrates and / or reticle stages and / or spacers and / or holders for measurement techniques / sensors and / or grid substrates and / or covers.

[0120] Another embodiment relates to precision parts with very small dimensions, in particular side lengths (width and / or depth) or diameters and / or thicknesses of a few mm (for example, up to 20 mm, up to 10 mm, up to 5 mm, up to 2 mm or up to 1 mm), which can be used as covers for lightweight structures, for example in microlithography and EUV lithography.

[0121] However, very large precision parts can also be produced. Thus, one embodiment of the present invention relates to large-volume parts, which in the sense of the present application should be understood to mean parts weighing at least 300 kg, in particular at least 400 kg, in particular at least 500 kg, in particular at least 1 t, more preferably at least 2 t, and in one variant of the invention at least 5 t, or parts which, in the case of polygons (rectangles), have a side length (width and / or depth) of at least 0.5 m, more preferably at least 1 m or at most 2 m, preferably at most 1.5 m, and / or a thickness (height) of at least 50 mm, in particular at least 100 mm, preferably at least 200 mm, and even more preferably at least 250 mm, or parts which, in the case of circles, have a diameter of at least 0.5 m, more preferably at least 1 m, more preferably at least 1.5 m, and / or a thickness (height) of at least 50 mm, in particular at least 100 mm, preferably at least 200 mm, and even more preferably at least 250 mm. Such precision components can be used, for example, in EUV lithography, not only in low NA systems but also as so-called second generation mirrors in high NA systems.

[0122] Using the glass ceramics according to the invention, EUVL precision components can be manufactured in the above-mentioned sizes.

[0123] In particular embodiments of the invention, the parts may be even larger, for example having a diameter of at least 1 m or at least 2 m or more and / or a thickness of 50 mm to 400 mm, preferably 100 mm to 300 mm. According to one variant, the invention also relates to rectangular parts, in particular parts having at least one side with a thickness of at least 1 m. 2 , especially at least 1.2 m 2 , more preferably at least 1.4 m 2 , more preferably at least 3 m 2 Or at least 4m 2and / or a thickness of 50 mm to 400 mm, preferably 100 mm to 300 mm. Large volume parts are usually produced whose base area is significantly greater than their height. However, these can also be large volume parts with a shape approximating a cube or sphere.

[0124] In one advantageous embodiment of the EUVL precision component, the EUVL precision component comprises at least one inorganic material selected from the group consisting of doped quartz glass, glass ceramics and ceramics, in particular Ti-doped quartz glass, LAS glass ceramics and cordierite.

[0125] The present invention also provides an EUVL precision part, which has an average coefficient of thermal expansion (CTE) of 0±0.1×10 at most in the range of 0 to 50°C. -6 / K, a thermal hysteresis of <0.1 ppm in the temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, particularly preferably at least 10°C to 35°C, and a parameter F of <1.2, where F = TCL(0;50°C) / |Expansion(0;50°C)|, and the precision component comprises at least one inorganic material selected from the group consisting of doped quartz glass, glass ceramics and ceramics, in particular Ti-doped quartz glass, LAS glass ceramics and cordierite.

[0126] The present invention also provides an EUVL precision part, which has an average coefficient of thermal expansion (CTE) of 0±0.1×10 at most in the range of 0 to 50°C. -6 / K, and the thermal hysteresis is less than 0.1 ppm in a temperature range of at least 19 ° C. to 25 ° C., preferably at least 10 ° C. to 25 ° C., particularly preferably at least 10 ° C. to 35 ° C., and the precision part has an alternative parameter f (20;40) <0.024 ppm / K, alternative parameter f (20;70) <0.039 ppm / K, alternative parameter f (-10;30) <0.015 ppm / K. T.i.and the precision component comprises at least one inorganic material selected from the group consisting of doped quartz glass, glass ceramics and ceramics, preferably Ti-doped quartz glass, LAS glass ceramics and cordierite.

[0127] In an advantageous development, the inorganic material is a hysteresis-free, zero-expansion LAS glass ceramic. Advantageously, the LAS glass ceramic contains less than 0.6 mol % of MgO and / or ZnO. Advantageously, it may contain 60-71 mol % SiO2 and 7-9.4 mol % Li2O. An advantageous version of the precision component comprises an LAS glass ceramic according to the invention, the inventive features and advantageous developments of which are described in detail below. The description below of the LAS glass ceramic and its advantageous developments also applies, where appropriate, to precision components comprising such an LAS glass ceramic, so reference is made thereto for the advantageous composition and advantageous features of the material.

[0128] Furthermore, the present invention also relates to an EUVL precision component according to the present invention selected from the group consisting of a photomask or reticle, a photomask substrate or reticle mask blank or mask blank, a photomask support or reticle stage, a mirror, a mirror support and a wafer support or wafer stage, in particular a photomask or reticle and / or a photomask substrate or reticle mask blank or mask blank and / or a photomask support or reticle stage.

[0129] The invention also relates to the use of an EUVL precision component according to the invention.

[0130] Therefore, advantageously, the EUVL precision component according to the invention can be used in EUV lithography.

[0131] EUV lithography in the sense of the present invention also includes EUV microlithography.

[0132] The invention therefore also relates to the use of an EUVL precision component according to the invention, advantageously in EUVL lithography, in particular as a photomask or reticle, a photomask substrate or reticle mask blank or mask blank, a photomask support or reticle stage, a mirror, a mirror support and / or a wafer support or wafer stage.

[0133] The EUVL precision component may be, for example, an optical component, in particular a so-called normal incidence mirror, i.e., a mirror operating near normal incidence of radiation, or a so-called grazing incidence mirror, i.e., a mirror operating at a grazing incidence of radiation. Such mirrors include, in addition to a substrate, a coating that reflects the incident radiation. In particular, in the case of an X-ray mirror, the reflective coating is, for example, a multilayer system or multilayer having several layers with high reflectivity in the X-ray range at non-grazing incidence. Preferably, such a multilayer system for a normal incidence mirror includes 40 to 200 pairs of alternating layers of one of the material pairs Mo / Si, Mo / Bi, Ru / Si, and / or MoRu / Be.

[0134] In particular, the optical element according to the invention may be an X-ray optical element, i.e. an optical element used in combination with X-rays, in particular soft X-rays or EUV radiation, in particular a reticle mask or photomask operating in reflection, in particular for EUV (micro)lithography. Advantageously, this may be a mask blank. Even more advantageously, the precision component can be used as a mirror or as a substrate for a mirror for EUV lithography.

[0135] As already explained, advantageous embodiments of the EUVL precision component or glass-ceramic according to the invention exhibit a flat CTE profile over a wide temperature range. These embodiments are therefore advantageous when used in EUVL applications where temperatures may be below and / or above typical application temperatures, for example, because the photomask and / or photomask support are actively cooled and / or the use of a higher-power EUV beam source and / or the use of smaller photomasks and photomask supports may result in localized temperature increases in the photomask or photomask support. Furthermore, EUVL precision components exhibiting the described flat CTE profile over a wide temperature range are advantageous with regard to the adhesion and / or durability of reflective multilayer coating systems applied to the photomask substrate, since in this case a reduction in tensile stress may occur during temperature changes during the manufacture and use of the photomask.

[0136] In EUV lithography, further advantages, particularly with regard to the resulting image quality, may arise if different EUVL precision parts are matched or adapted to one another with regard to their thermal properties, such as CTE, CTE progression, thermal hysteresis, etc., in particular due to the fact that different EUVL precision parts have very similar or nearly identical thermal properties. Therefore, it may be advantageous to use the same material for the photomask substrate and the photomask support in particular.

[0137] Due to their excellent mechanical stability, EUVL precision components made from the advantageous glass ceramics according to the invention can be used in so-called high-NA EUVL systems or other EUVL systems with increased wafer throughput. The high elastic modulus of LAS glass ceramics compared to other materials, such as Ti-doped quartz glass, allows for improved dynamic positioning accuracy here, especially of photomasks.

[0138] The EUVL precision component according to the present invention, particularly the photomask support and / or wafer support, may be a lightweight structure. The component according to the present invention may further include a lightweight structure. This means that a cavity is provided in some areas of the component to reduce weight. In particular, the weight of the component is reduced by at least 80%, more preferably at least 90%, compared to the unprocessed component by lightweight processing.

[0139] The invention further relates to LAS glass ceramics, in particular for EUVL precision components according to the invention, having an average coefficient of thermal expansion CTE in the range of 0 to 50°C of at most 0±0.1 × 10 -6 / K, a thermal hysteresis of <0.1 ppm in a temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, particularly preferably at least 10°C to 35°C, and containing (in mole % on an oxide basis) the following components: SiO260~71 Li2O 7~9.4 MgO+ZnO 0~<0.6 at least one component selected from the group consisting of P2O5, R2O and RO, wherein R2O may be Na2O and / or K2O and / or Cs2O and / or Rb2O, and RO may be CaO and / or BaO and / or SrO; Nucleating agent: 1.5-6 mol % content, where the nucleating agent is TiO 2、 ZrO 2、 At least one component selected from the group consisting of Ta2O5, Nb2O5, SnO2, MoO3, and WO3 Including LAS glass ceramics.

[0140] In an advantageous embodiment, the EUVL precision component can comprise a substrate comprising a glass ceramic according to the invention. In a further advantageous embodiment, the EUVL precision component can comprise or consist of a glass ceramic according to the invention.

[0141] In the present invention, zero-expansion glass-ceramics are provided for the first time, exhibiting extremely low thermal hysteresis of <0.1 ppm at least in the temperature range of 19°C to 25°C, preferably at least in the temperature range of 10°C to 25°C, and particularly preferably at least in the temperature range of 10°C to 35°C. Materials exhibiting such low hysteresis effects of less than 0.1 ppm in the aforementioned temperature ranges are hereinafter referred to as "hysteresis-free." As already explained above, the form of hysteresis depends on the rate of temperature change used to determine it. Therefore, in the present invention, references to hysteresis relate to a heating / cooling rate of 36 K / h, i.e., 0.6 K / min. In advantageous embodiments, the LAS glass-ceramics can be hysteresis-free at least in the temperature range of 5°C to 35°C, or at least in the temperature range of 5°C to 40°C, advantageously at least in the temperature range of >0°C to 45°C, and preferably at least in the temperature range of -5°C to 50°C.

[0142] The CTE and thermal hysteresis have already been explained in detail above in connection with EUVL precision components. All explanations, including the differences from the prior art indicated, apply equally to the LAS glass ceramics according to the invention.

[0143] According to the present invention, glass ceramics are understood to be inorganic, non-porous materials having a crystalline phase and a glassy phase, with the matrix, or continuous phase, usually being a glass phase. To produce glass ceramics, the components of the glass ceramic are first mixed, melted, refined, and poured to produce a so-called green glass. After cooling, this green glass is reheated and crystallized in a controlled manner (so-called "controlled volume crystallization"). The analytical chemical composition of the green glass is identical to that of the glass ceramic produced therefrom; ceramization changes only the internal structure of the material. Therefore, when the composition of a glass ceramic is mentioned below, the same applies to the precursor of the glass ceramic, i.e., the green glass.

[0144] Within the scope of the present invention, it has been recognized for the first time that both MgO and ZnO contribute to the development of thermal hysteresis in the temperature range in question, and that therefore, in order to provide a zero-expansion LAS glass-ceramic that is hysteresis-free at least in the temperature range of 10°C to 35°C, it is essential to limit the MgO and ZnO contents as shown below. In contrast, it has previously been believed that, particularly in zero-expansion LAS glass-ceramics, the use of these glass components in combination or individually is necessary to achieve zero expansion and to "flatten" the shape of the CTE-T curve of the material, i.e., to reduce the slope of the CTE-T curve in the temperature range in question. Consequently, there has been a conflict of opinion as to whether to make LAS glass-ceramics zero-expansion or hysteresis-free.

[0145] This inconsistency in directionality is resolved by the present invention not only by largely omitting the use of MgO and ZnO, but also by selecting the SiO2 and Li2O contents within the ranges specified by the present invention. Surprisingly, it has been found that zero-expansion and hysteresis-free glass-ceramics can be obtained within the ranges specified by the SiO2 (60-71 mol%) and Li2O (7-9.4 mol%) contents within the scope of the present invention.

[0146] LAS glass ceramics comprise a crystalline phase exhibiting negative expansibility and a glassy phase exhibiting positive expansibility, which, within the scope of the present invention, advantageously comprises or consists of a high-quartz solid solution, also known as β-eucryptite. In addition to SiO and AlO, one of the main components of the solid solution is LiO. If present, ZnO and / or MgO are also incorporated into the solid solution phase and, together with LiO, affect the expansion behavior of the crystalline phase. This means that the aforementioned provisions according to the present invention (reduction, especially elimination, of MgO and ZnO) significantly affect the type and properties of the solid solution formed during ceramization. In contrast to known zero-expansion glass-ceramics, in which MgO and ZnO are used inter alia to adjust the desired expansion behavior of the glass-ceramics, at least one component selected from the group consisting of PO, RO and RO, where RO may be NaO and / or KO and / or RbO and / or CsO, and RO may be CaO and / or BaO and / or SrO, is used within the scope of the present invention. However, when the aforementioned alkaline earth metal oxides and alkali metal oxides are present, they, unlike MgO and ZnO, remain in the glass phase and are not incorporated into the high-quartz solid solution.

[0147] In the context of the present invention, it has been found to be advantageous for the provision of zero-expansion and hysteresis-free glass-ceramics if the composition satisfies the condition: molar content of SiO + (5 × molar content of LiO) ≥ 10 or preferably ≥ 10.5, in particular molar content of SiO + (5 × molar content of LiO) ≥ 10 ≥ 10.5 Alternatively or additionally, advantageous upper limits of ≤ 115.5, ≤ 114.5 or ≤ 113.5 may hold for the condition "molar content of SiO + (5 × molar content of LiO)".

[0148] In an advantageous development, the glass ceramic comprises, individually or in any combination, the following components in molar percentages: [Table 1] may include:

[0149] In an advantageous development, the glass ceramic comprises, individually or in any combination, the following components in molar percentages: [Table 2] may include:

[0150] More preferably, the glass ceramic contains, individually or in any combination, the following components in mole %, within the above-mentioned limits for R2O, RO and the sum of TiO2 + ZrO2: [Table 3] may be included.

[0151] In one advantageous embodiment, the LAS glass ceramic comprises (in mole % on an oxide basis): [Table 4] wherein the nucleating agent is preferably TiO2 and / or ZrO2.

[0152] In one advantageous embodiment, the LAS glass ceramic comprises (in mole % on an oxide basis): [Table 5] wherein the nucleating agent is preferably TiO2 and / or ZrO2.

[0153] In a further advantageous embodiment, the LAS glass ceramic comprises (in mole % on an oxide basis): [Table 6] wherein the nucleating agent is preferably TiO2 and / or ZrO2.

[0154] The glass ceramics have a silicon dioxide (SiO2) content of at least 60 mol%, more preferably at least 60.5 mol%, also preferably at least 61 mol%, also preferably at least 61.5 mol%, and even more preferably at least 62.0 mol%. The SiO2 content is at most 71 mol% or less, more preferably at most 70 mol% or less, even more preferably at most 69 mol%, and even more preferably at most 68.5 mol%. A high SiO2 content makes batch melting difficult and increases the viscosity of the melt, which can cause problems with melt homogenization in large-scale production plants. Therefore, it is desirable for the content not to exceed 71 mol%, preferably 70 mol%. A high melt viscosity increases the melt processing temperature (Va). Very high temperatures are required for melt clarification and homogenization, which can lead to attack of the melting unit lining due to the aggressiveness of the melt, which increases with temperature. Furthermore, even high temperatures may not be sufficient to produce a homogeneous melt, which can result in striae and inclusions in the green glass (especially bubbles and particles originating from the lining of the melting unit), which, after ceramization, do not meet the requirements regarding the uniformity of the properties of the produced glass-ceramics, for example the requirements regarding the uniformity of the thermal expansion coefficient. For this reason, an SiO2 content below the aforementioned upper limit may be preferable.

[0155] The proportion of Al2O3 is advantageously at least 10 mol%, advantageously at least 11 mol%, preferably at least 12 mol%, more preferably at least 13 mol%, also preferably at least 14 mol%, also preferably at least 14.5 mol%, and even more preferably at least 15 mol%. If the content is too low, a low-expansion solid solution is not formed, or if formed, it is formed in too small an amount. The proportion of Al2O3 is advantageously at most 22 mol%, in particular at most 21 mol%, preferably at most 20 mol%, even more preferably at most 19.0 mol%, and even more preferably at most 18.5 mol%. If the content of Al2O3 is too high, the viscosity increases and promotes uncontrollable devitrification of the material.

[0156] The glass ceramics according to the present invention may contain 0 to 6 mol % P2O5, and in some advantageous embodiments, 0.1 to 6 mol %. The phosphate content of P2O5 in the glass ceramics may be advantageously at least 0.1 mol %, in particular at least 0.3 mol %, preferably at least 0.5 mol %, also preferably at least 0.6 mol %, more preferably at least 0.7 mol %, and even more preferably at least 0.8 mol %. P2O5 is substantially incorporated into the crystalline phase of the glass ceramic, favorably influencing the expansion behavior of the crystalline phase and, therefore, the expansion behavior of the glass ceramic. Furthermore, it improves the solubility of the components and the fining behavior of the melt. However, if the P2O5 content is excessively high, the CTE-T curve in the temperature range from 0°C to 50°C will no longer exhibit the advantageously flat curve. Therefore, it is advantageous to have a maximum of 6 mol %, in particular at most 5 mol %, more preferably at most 4 mol %, and even more preferably less than 4 mol % P2O5 in the glass ceramics. According to particular embodiments, the glass-ceramics may be free of P2O5.

[0157] Within the scope of the present invention, certain sums and ratios of the components SiO2, Al2O3 and / or P2O5, i.e. components that form a high-quartz solid solution, can promote the formation of glass-ceramics according to the invention.

[0158] The total proportion in mole percent of the base components SiO and AlO of the LAS glass ceramic is advantageously at least 75 mole percent, in particular at least 78 mole percent, preferably at least 79 mole percent, more preferably at least 80 mole percent, and / or in particular at most 90 mole percent, in particular at most 87 mole percent, preferably at most 86 mole percent, more preferably at most 85 mole percent. If this total is too high, the viscosity curve of the melt will shift to higher temperatures, which is disadvantageous as already explained above in connection with the component SiO. If the total is too low, too little solid solution will be formed.

[0159] The total proportion in molar percentage of the base components SiO, AlO and PO of the LAS glass ceramic is in particular at least 77 mol%, advantageously at least 81 mol%, advantageously at least 83 mol%, more preferably at least 84 mol% and / or in particular at most 91 mol%, advantageously at most 89 mol%, more preferably at most 87 mol%, and according to one variant at most 86 mol%.

[0160] The ratio of the molar percentages of P2O5 to SiO2 is in particular at least 0.005, advantageously at least 0.01, preferably at least 0.012 and / or in particular at most 0.1, more preferably at most 0.08, and according to one variant at most 0.07.

[0161] As an additional component, the glass ceramic contains lithium oxide (LiO) in a proportion of at least 7 mol%, preferably at least 7.5 mol%, in particular at least 8 mol%, and particularly preferably at least 8.25 mol%. The proportion of LiO is limited to a maximum of 9.4 mol%, more preferably at a maximum of 9.35 mol%, and even more preferably at a maximum of 9.3 mol% or less. LiO is a component of the solid solution phase and has a significant influence on the thermal expansion of the glass ceramic. It is desirable not to exceed the aforementioned upper limit of 9.4 mol%, because exceeding this upper limit would result in a glass ceramic with a negative coefficient of thermal expansion (CTE) of (0:50). If the LiO content is less than 7 mol%, the solid solution is not formed sufficiently, and the CTE of the glass ceramic remains positive.

[0162] Glass-ceramics can contain at least one alkaline earth metal oxide selected from the group consisting of CaO, BaO, and SrO, collectively referred to as "RO." Each component of the RO group remains substantially in the amorphous glass phase of the glass-ceramic and can be important for ensuring the zero expansion of the ceramized material. If the sum of CaO, BaO, and SrO is too high, the CTE (0:50) targeted by the present invention will not be achieved. Therefore, the RO content is advantageously at most 6 mol% or at most 5.5 mol%, particularly at most 5 mol%, advantageously at most 4.5 mol%, especially at most 4 mol%, preferably at most 3.8 mol%, even more preferably at most 3.5 mol%, and preferably at most 3.2 mol%. If the glass-ceramic contains RO, an advantageous lower limit can be at least 0.1 mol%, advantageously at least 0.2 mol%, preferably at least 0.3 mol%, and preferably at least 0.4 mol%. According to particular embodiments, the glass-ceramics may be free of RO.

[0163] The proportion of CaO may be, in particular, at most 5 mol%, advantageously at most 4 mol%, advantageously at most 3.5 mol%, advantageously at most 3 mol%, even more preferably at most 2.8 mol%, and more preferably at most 2.6 mol%. The glass ceramic may advantageously contain at least 0.1 mol%, advantageously at least 0.2 mol%, especially at least 0.4 mol%, and preferably at least 0.5 mol% of CaO. The glass ceramic may advantageously contain the component BaO, which is a good glass former, in a proportion of at least 0.1 mol%, especially at least 0.2 mol%, and / or at most 4 mol%, advantageously at most 3 mol%, advantageously at most 2.5 mol%, especially at most 2 mol%, preferably at most 1.5 mol%, and also preferably at most 1.4 mol%. The glass ceramics can contain SrO in a proportion of at most 3 mol%, advantageously at most 2 mol%, in particular at most 1.5 mol%, preferably at most 1.3 mol%, preferably at most 1.1 mol%, more preferably at most 1 mol%, also preferably at most 0.9 mol% and / or in particular at least 0.1 mol%. According to individual embodiments, the glass ceramics do not contain CaO and / or BaO and / or SrO.

[0164] Sodium oxide (NaO) and / or potassium oxide (KO) and / or cesium oxide (CsO) and / or rubidium oxide (RbO) are optionally present in the glass ceramics, i.e., NaO-free and / or KO-free and / or CsO-free and / or RbO-free variants are possible. The proportion of NaO can be advantageously at most 3 mol%, preferably at most 2 mol%, in particular at most 1.7 mol%, preferably at most 1.5 mol%, preferably at most 1.3 mol%, and preferably at most 1.1 mol%. The proportion of KO can be advantageously at most 3 mol%, in particular at most 2.5 mol%, preferably at most 2 mol%, preferably at most 1.8 mol%, and preferably at most 1.7 mol%. The proportion of CsO may advantageously be at most 2 mol%, in particular at most 1.5 mol%, preferably at most 1 mol%, and preferably at most 0.6 mol%. The proportion of RbO may advantageously be at most 2 mol%, in particular at most 1.5 mol%, preferably at most 1 mol%, and preferably at most 0.6 mol%. According to individual embodiments, the glass-ceramics do not contain NaO and / or KO and / or CsO and / or RbO.

[0165] NaO, KO, CsO, and RbO may each be present in the glass-ceramic independently in a proportion of at least 0.1 mol %, in particular at least 0.2 mol %, and more preferably at least 0.5 mol %. The components NaO, KO, CsO, and RbO remain substantially in the amorphous glass phase of the glass-ceramic and can be important for maintaining the zero expansion properties of the ceramized material.

[0166] Thus, the sum of the R2O contents of Na2O, K2O, Cs2O, and Rb2O may be advantageously at least 0.1 mol%, in particular at least 0.2 mol%, advantageously at least 0.3 mol%, and preferably at least 0.4 mol%. A low R2O content, advantageously at least 0.2 mol%, can help increase the temperature range in which the expansion curve of the glass-ceramic exhibits a flatter profile. The sum of the R2O contents of Na2O, K2O, Cs2O, and Rb2O may be advantageously at most 6 mol%, in particular at most 5 mol%, preferably at most 4 mol%, preferably at most 3 mol%, and preferably at most 2.5 mol%. If the sum of Na2O + K2O + Cs2O + Rb2O is too low or too high, the desired CTE (0:50) may not be achieved according to the present invention. According to individual embodiments, the glass-ceramic may be free of R2O.

[0167] The glass ceramic may contain at most 0.35 mol% magnesium oxide (MgO). Further advantageous upper limits may be at most 0.3 mol%, at most 0.25 mol%, at most 0.2 mol%, at most 0.15 mol%, at most 0.1 mol%, or at most 0.05 mol%. Particularly preferably, the glass ceramic according to the invention is free of MgO. As mentioned above, the MgO component in the glass ceramic causes thermal hysteresis in the temperature range from 0°C to 50°C. The less MgO contained in the glass ceramic, the smaller the hysteresis in the aforementioned temperature range.

[0168] The glass ceramic may contain at most 0.5 mol% zinc oxide (ZnO). Further advantageous upper limits may be at most 0.45 mol%, at most 0.4 mol%, at most 0.35 mol%, at most 0.3 mol%, at most 0.25 mol%, at most 0.2 mol%, at most 0.15 mol%, at most 0.1 mol%, or at most 0.05 mol%. Particularly preferably, the glass ceramic according to the invention does not contain ZnO. As already mentioned above, the inventors have found that the ZnO component in glass ceramics causes thermal hysteresis in the temperature range from 0°C to 50°C. The less ZnO contained in the glass ceramic, the smaller the hysteresis in the aforementioned temperature range.

[0169] For the hysteresis-free properties of the glass-ceramics according to the invention, it is important that the condition that MgO+ZnO is less than 0.6 mol% is met. Further advantageous upper limits for the sum of MgO+ZnO can be at most 0.55 mol%, at most 0.5 mol% or less than 0.5 mol%, at most 0.45 mol%, at most 0.4 mol%, at most 0.35 mol%, at most 0.3 mol%, at most 0.25 mol%, at most 0.2 mol%, at most 0.15 mol%, at most 0.1 mol%, or at most 0.05 mol%.

[0170] The glass ceramic further comprises at least one nucleating agent selected from the group consisting of TiO2, ZrO2, Ta2O5, Nb2O5, SnO2, MoO3, and WO3. The nucleating agent may be a combination of two or more of the above components. A further advantageous nucleating agent may be HfO2. Thus, in an advantageous embodiment, the glass ceramic comprises HfO2 and at least one nucleating agent selected from the group consisting of TiO2, ZrO2, Ta2O5, Nb2O5, SnO2, MoO3, and WO3. The total proportion of nucleating agents is, in particular, at least 1.5 mol%, preferably at least 2 mol% or more than 2 mol%, more preferably at least 2.5 mol%, and in certain variants, at least 3 mol%. The upper limit can be at most 6 mol%, in particular at most 5 mol%, preferably at most 4.5 mol% or at most 4 mol%. In a particularly advantageous variant, the stated upper and lower limits apply to the sum of TiO2 and ZrO2.

[0171] The glass ceramics may contain titanium oxide (TiO) in a proportion of at least 0.1 mol%, advantageously at least 0.5 mol%, in particular at least 1.0 mol%, preferably at least 1.5 mol%, preferably at least 1.8 mol%, and / or in particular at most 5 mol%, advantageously at most 4 mol%, more preferably at most 3 mol%, even more preferably at most 2.5 mol%, preferably 2.3 mol%. TiO-free variants of the glass ceramics according to the invention are also possible.

[0172] The glass ceramics can advantageously further comprise zirconium oxide (ZrO) in a proportion of at most 3 mol%, in particular at most 2.5 mol%, more preferably at most 2 mol%, and preferably at most 1.5 mol% or 1.2 mol%. In particular, ZrO may be present in a proportion of at least 0.1 mol%, more preferably at least 0.5 mol%, at least 0.8 mol%, or at least 1.0 mol%. ZrO-free variants of the glass ceramics according to the invention are also possible.

[0173] According to some advantageous variants of the invention, 0 to 5 mol % of Ta2O5 and / or Nb2O5 and / or SnO2 and / or MoO3 and / or WO3, individually or in total, may be included in the glass-ceramics, for example, as alternative or additional nucleation agents or to adjust optical properties, such as the refractive index. HfO2 may also serve as an alternative or additional nucleation agent. To adjust the optical properties, some advantageous variants may include, for example, Gd2O3, YO3, HfO2, Bi2O3, and / or GeO2.

[0174] Glass ceramics are As2O3, Sb2O3, SnO2, SO4 2- , F - , Cl - , Br - or mixtures thereof in a proportion of more than 0.05 mol %, or at least 0.1 mol % and / or at most 1 mol %. However, since the fining agent fluorine can reduce the transparency of the glass-ceramic, if present, this component is advantageously limited to at most 0.5 mol %, preferably at most 0.3 mol %, and preferably at most 0.1 mol %. Preferably, the glass-ceramic is fluorine-free.

[0175] An advantageous embodiment of the invention is an LAS glass ceramic, in particular for an EUVL precision component or an EUVL precision component, which glass ceramic comprises As2O3 as a fining agent.

[0176] In another advantageous embodiment of the LAS glass ceramic or EUVL precision component, the LAS glass ceramic contains a maximum of 0.05 mol% As2O3 as a fining agent. Advantageously, the As2O3 content in the glass ceramic is ≦0.04 mol%, in particular ≦0.03 mol%, preferably ≦0.025 mol%, preferably ≦0.02 mol%, and preferably ≦0.015 mol%. It is advantageous for the glass ceramic to contain as little As2O3 as possible. A particularly preferred variant of the glass ceramic is substantially As2O3-free, where "substantially As2O3-free or As-free" means that the As2O3 component is not intentionally added to the composition as a component and is present only as an impurity. For As2O3-free glass ceramics, the As2O3 impurity limit is ≦0.01 mol%, in particular ≦0.005 mol%. According to a specific embodiment, the glass ceramic is free of As2O3.

[0177] It has surprisingly been found that, even if the glass-ceramics according to an advantageous embodiment are refined in a more environmentally friendly manner within the scope defined by the present invention, i.e., contain a maximum of 0.05 mol % As2O3, and preferably are substantially As2O3-free, zero-expansion and hysteresis-free glass-ceramics are obtained.

[0178] In order to provide advantageous embodiments of hysteresis-free zero-expansion glass-ceramics with the desired internal quality, in particular with a low number of bubbles and low striae, despite a reduced As2O3 content or even without As2O3, in an advantageous embodiment at least one chemical fining agent is used.

[0179] In an advantageous embodiment, the glass-ceramic can contain, as chemical fining agent, at least one alternative redox fining agent and / or at least one evaporative fining agent and / or at least one decomposition fining agent instead of As2O3 or in addition to a small proportion (maximum 0.05 mol%) of As2O3. Since As2O3 is also a redox fining agent, within the scope of the present invention, redox fining agents used instead of or in addition to As2O3 are referred to as "alternative redox fining agents".

[0180] In an advantageous embodiment, the total content of chemical fining agents detectable in the glass ceramic (excluding the content of As2O3, if present in the glass ceramic) can be in the range of 0 mol% to 1 mol%. In an advantageous embodiment, the total content of fining agents detectable in the glass ceramic (excluding As2O3) is greater than 0.01 mol%, in particular at least 0.05 mol%, in particular at least 0.1 mol%, in particular at least 0.15 mol%, advantageously at least 0.2 mol% and / or at most 1 mol%, in particular at most 0.7 mol%, preferably at most 0.5 mol%, and preferably at most 0.4 mol%. Some advantageous variants can also contain fining agents in amounts of at most 0.3 mol%, in particular at most 0.25 mol%, or at most 0.2 mol%. The proportion of each component is detectable by analysis of the glass ceramic. This applies to all fining agents described below, except for the specifically mentioned sulfate components.

[0181] Redox fining agents contain highly or multivalent ions capable of adopting at least two oxidation states in temperature-dependent equilibrium with one another, releasing gases, usually oxygen, at high temperatures. Therefore, certain multivalent metal oxides can be used as redox fining agents. In an advantageous variant, the alternative redox fining agent can be at least one component selected from the group consisting of Sb2O3, SnO2, CeO2, MnO2, and Fe2O3. However, in principle, other redox compounds are also suitable, provided they release fining gases in the temperature range relevant for fining and the valence of the metal ion changes to a different oxide or to the metallic form. Many such compounds are described, for example, in DE 19939771 A1. Preference is given to alternative redox fining agents, such as Sb2O3, SnO2, and CeO2, that release fining gases, especially oxygen, at temperatures below 1700°C.

[0182] The content of As2O3 and / or the content of at least one alternative redox fining agent can be determined by analyzing the glass-ceramic, from which a person skilled in the art can draw inferences regarding the type and amount of fining agent used. The alternative redox fining agent can be added to the batch, for example, as an oxide.

[0183] In an advantageous embodiment, the total content of alternative redox fining agents can be in the range of 0 mol% to 1 mol%. In an advantageous embodiment, the total content of alternative redox fining agents detectable in the glass-ceramic is greater than 0.01 mol%, in particular at least 0.05 mol%, in particular at least 0.1 mol%, in particular at least 0.15 mol%, advantageously at least 0.2 mol% and / or at most 1 mol%, in particular at most 0.7 mol%, preferably at most 0.5 mol%, preferably at most 0.4 mol%. Some advantageous variations can also include at most 0.3 mol%, in particular at most 0.25 mol%, or at most 0.2 mol% of alternative redox fining agents.

[0184] The glass-ceramics can contain 0 mol% to 1 mol% antimony oxide (Sb2O3) as an alternative redox fining agent. In one advantageous embodiment, the glass-ceramics contain more than 0.01 mol% Sb2O3, in particular at least 0.05 mol%, advantageously at least 0.1 mol%, advantageously at least 0.15 mol%, especially at least 0.2 mol%, and / or in particular at most 1 mol%, advantageously at most 0.7 mol%, more preferably at most 0.5 mol%, even more preferably at most 0.4 mol%, and preferably at most 0.3 mol%. Since Sb2O3 is considered harmful to the environment, it can be advantageous to use as little Sb2O3 as possible in the fining process. A preferred embodiment of the glass-ceramics is substantially Sb2O3-free or Sb-free, where "substantially Sb2O3-free" means that Sb2O3 is not intentionally added to the composition as a raw material component, but is present at most as an impurity, and for Sb2O3-free glass-ceramics, the impurity limit is at most 0.01 mol %, in particular at most 0.005 mol %. According to a specific embodiment, the glass-ceramics are Sb2O3-free.

[0185] The glass ceramics can contain 0 mol% to 1 mol% tin oxide (SnO2) as an alternative redox fining agent. In one advantageous embodiment, the glass ceramics contain more than 0.01 mol% SnO2, in particular at least 0.05 mol%, advantageously at least 0.1 mol%, advantageously at least 0.15 mol%, in particular at least 0.2 mol%, in particular at least 0.3 mol%, and / or in particular at most 1 mol%, advantageously at most 0.7 mol%, and more preferably at most 0.6 mol%. In some variations, an upper limit of at most 0.5 mol%, even more preferably at most 0.4 mol%, and preferably at most 0.3 mol% can be advantageous. If the SnO2 content is too high, the high SnO2 content can act not only as a fining agent but also as a crystal nucleation agent, making the ceramization process of the green glass more difficult to control. SnO2-free or Sn-free variants of the glass ceramics according to the invention are possible and advantageous, i.e., no Sn-containing raw materials are added to the batch for fining the base green glass, with the limit for raw material or process-introduced SnO2 impurities being at most 0.01 mol %, in particular at most 0.005 mol %.

[0186] The glass-ceramics may contain 0 mol % to 1 mol % of CeO2 and / or MnO2 and / or Fe2O3 as alternative redox fining agents, each of which may be present independently of one another in a proportion of more than 0.01 mol %, in particular at least 0.05 mol %, advantageously at least 0.1 mol %, advantageously at least 0.15 mol %, in particular at least 0.2 mol %, and / or in particular at most 1 mol %, advantageously at most 0.7 mol %, more preferably at most 0.5 mol %, even more preferably at most 0.4 mol %, preferably at most 0.3 mol %. A preferred variant of the glass-ceramic is free of CeO2 and / or MnO2 and / or Fe2O3, i.e. no Ce-containing and / or Mn-containing and / or Fe-containing raw materials are added to the batch for fining the base green glass, with the limit for raw material or process-introduced CeO2 and / or MnO2 and / or Fe2O3 impurities being at most 0.01 mol %, in particular at most 0.005 mol %.

[0187] Evaporative fining agents are components that volatilize at high temperatures due to their vapor pressure, whereby the gas formed in the melt exerts a fining effect.

[0188] In one advantageous variant, the evaporative fining agent may contain a halogen component.

[0189] In an advantageous variant, the evaporative fining agent can contain at least one halogen with a fining effect, in particular selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I). A preferred halogen with a fining effect is chlorine. Fluorine is not a halogen with a fining effect because it volatilizes at excessively low temperatures. Nevertheless, the glass ceramic can contain fluorine. However, since fluorine can reduce the transparency of the glass ceramic, if this component is present, it is limited, in particular, to a maximum of 0.5 mol%, preferably a maximum of 0.3 mol%, and more preferably a maximum of 0.1 mol%. Preferably, the glass ceramic does not contain fluorine.

[0190] The fining halogen can be added in various forms. In one embodiment, it is added to the batch as a salt with an alkali metal or alkaline earth metal cation or as an aluminum halogen. In one embodiment, the halogen is used as a salt, and the cation in the salt corresponds to the cation present as an oxide in the glass ceramic. The fining halogen can be used in the form of a halide compound, particularly a halide compound. Suitable halide compounds are salts of chloride, bromide, and / or iodide anions with alkali metal or alkaline earth metal cations or aluminum cations. Preferred examples are chlorides such as LiCl, NaCl, KCl, CaCl2, BaCl2, SrCl2, AlCl3, and combinations thereof. Corresponding bromides and iodides are also possible, such as LiBr, LiI, NaBr, NaI, KBr, KI, CaI2, CaBr2, and combinations thereof. Other examples include BaBr2, BaI2, SrBr2, SrI2, and combinations thereof.

[0191] In an advantageous variant, the total content of halogens with a fining effect (i.e., Cl and / or Br and / or I) can be in the range of 0 mol% to 1 mol%. In an advantageous embodiment, the total content of halogens with a fining effect detectable in the glass ceramic is greater than 0.03 mol%, in particular at least 0.04 mol%, in particular at least 0.06 mol%, in particular at least 0.08 mol%, in particular at least 0.1 mol%, in particular at least 0.15 mol%, advantageously at least 0.2 mol% and / or at most 1 mol%, in particular at most 0.7 mol%, preferably at most 0.5 mol%, preferably at most 0.4 mol%. Some advantageous variants can also contain halogens with a fining effect in an amount of at most 0.3 mol%, in particular at most 0.25 mol%, or at most 0.2 mol%. The above contents relate to the amount of halogen detectable in the glass ceramic. Those skilled in the art are familiar with using these data to calculate the amount of halogen or halide compounds required for fining.

[0192] The glass ceramics can contain 0 mol% to 1 mol% chlorine (determined atomically and expressed as Cl). In one advantageous embodiment, the glass ceramics contain more than 0.03 mol%, advantageously at least 0.04 mol%, advantageously at least 0.05 mol%, advantageously at least 0.1 mol%, advantageously at least 0.15 mol%, in particular at least 0.2 mol%, and / or in particular at most 1 mol%, advantageously at most 0.7 mol%, more preferably at most 0.5 mol%, even more preferably at most 0.4 mol%, and preferably at most 0.3 mol% of Cl. Some advantageous glass ceramics can be Cl-free, i.e., no Cl-containing raw materials are added to the batch for fining the base green glass. Cl is present at most as an impurity, with the upper limit for Cl impurity being at most 0.03 mol%.

[0193] The same ranges and limits mentioned above also apply to Br as a halogen having a fining effect. The same ranges and limits mentioned above also apply to I as a halogen having a fining effect. A preferred variant of the glass-ceramic does not contain Br and / or I.

[0194] Instead of, or in addition to, evaporative fining agents and / or alternative redox fining agents, chemical fining agents may include at least one decomposition fining agent, which decomposes at high temperatures with the release of fining gases and the decomposition products are released at sufficiently high gas pressures, especially at 10 5 The decomposition fining agent is an inorganic compound having a gas pressure exceeding 0.1 Pa. Preferably, the decomposition fining agent is a salt containing an oxoanion, particularly a sulfate component. In particular, the decomposition fining agent contains a sulfate component. The decomposition of the component added as sulfate releases SO2 and O2 gases at high temperatures, which contribute to the fining of the melt.

[0195] The sulfate component can be added in various forms. In one embodiment, it is added to the batch as a salt with an alkali metal or alkaline earth metal cation. In one embodiment, the sulfate is used as a salt, and the cations in the salt correspond to the cations present as oxides in the glass-ceramic. For example, the following components can be advantageously used as sulfate sources: LiSO, NaSO, KSO, CaSO, BaSO, SrSO.

[0196] Within the scope of the present invention, sulfate is determined as SO3 in material analysis. However, since LAS glass-ceramics have very low solubility in sulfate, the sulfate component (i.e., SO3) in the molten product cannot be detected after melting by conventional X-ray fluorescence analysis. Therefore, in the case of the sulfate-fined embodiment (see below), the mol % of SO4 relative to the synthesis of the glass melt is determined. 2- Alternatively, the mole percent of SO3 used is stated. The use of sulfate components as fining agents can be determined, for example, by analyzing the residual gas content (SO2) in the glass-ceramics.

[0197] Preferred sulfate-fined glass-ceramics contain more than 0.01 mol %, in particular at least 0.05 mol %, advantageously at least 0.1 mol %, advantageously at least 0.15 mol %, in particular at least 0.2 mol % and / or in particular at most 1 mol %, advantageously at most 0.7 mol %, more preferably at most 0.5 mol %, even more preferably at most 0.4 mol %, preferably at most 0.3 mol % of SO3 added during synthesis via at least one corresponding sulfate compound. Sulfate-free (i.e., SO3-free or SO4 2- Fined (free) glass-ceramics are possible and advantageous. The proportion of fining sulfates added in the synthesis of glass-ceramics can therefore be in the range of 0 mol % to 1 mol % SO3.

[0198] According to one variant of the invention, the glass ceramic or base glass can be refined using a suitable metal sulfide as a decomposition fining agent, as described, for example, in U.S. Patent Application Publication No. 2011 / 0098171. In one embodiment, the cations in the sulfide correspond to the cations present as oxides in the glass ceramic. Examples of suitable metal sulfides are alkali metal sulfides, alkaline earth metal sulfides, and / or aluminum sulfide, which release SO3 in the melt under oxidizing conditions. To fully function as a fining agent, metal sulfides are advantageously used in combination with an oxidizing agent, especially nitrates and / or sulfates.

[0199] Preferred glass-ceramics with reduced As2O3 content or free As2O3 can contain a combination of chemical fining agents, whereby the following combinations may be advantageous, each glass-ceramic containing the aforementioned fining agents, in particular individually and / or in total, within the aforementioned limits. - SnO2 and / or Sb2O3 with up to 0.05 mol% of each As2O3; or - As2O3-free combinations, for example Sb2O3 and SnO2; Sb2O3 and Cl, Sb2O3 and SO3; or - Combinations that do not contain As2O3 and do not contain Sb2O3, for example, a combination of SnO2 and Cl, a combination of SnO2 and SO3, a combination of Cl and SO3 Includes:

[0200] Glass-ceramics that have been refined with only one fining agent may also be advantageous, for example glass-ceramics that contain only Sb2O3 or only SnO2 as fining agent.

[0201] Instead of or in addition to the above-described fining treatments of the melt with chemical fining agents, the principle of which is the addition of compounds which decompose to release a gas or which volatilize at high temperatures or which release a gas in an equilibrium reaction at high temperatures, known physical fining processes can also be used to advantage, such as, for example, reducing the viscosity of the glass melt by increasing the temperature, vacuum fining, high-pressure fining, etc.

[0202] In one advantageous variant of the invention, the batch can contain nitrates (NO3), which act as oxidizing agents in the melting and fining process, ensuring that oxidizing conditions exist in the melt, thereby enhancing the effectiveness of the fining agents used, especially alternative redox fining agents. In one embodiment, the nitrates are used as salts, the cations in the salts corresponding to the cations present as oxides in the glass-ceramic. Examples of this would be: aluminum nitrate, alkali metal nitrates, alkaline earth metal nitrates, zirconium nitrate. However, ammonium nitrate can also advantageously serve as a nitrate source. One nitrate compound or a mixture of several nitrate compounds can be used. If a nitrate compound or a mixture of nitrate compounds is included in the batch to support the fining process, NO3 -The total of is particularly at least 0.4 mol%, particularly at least 0.5 mol%, particularly at least 0.8 mol%, preferably at least 1 mol% and / or advantageously at most 5 mol%, particularly at most 4 mol%. In some advantageous variants, up to 3 mol% of nitrate can also be used. Due to their volatility, nitrate cannot be detected in glass or glass ceramics.

[0203] The above glass compositions can optionally contain coloring oxide additives, such as Nd2O3, Fe2O3, CoO, NiO, V2O5, MnO2, CuO, CeO2, Cr2O3, rare earth oxides, each individually or in total in a content of 0 to 3 mol %. A preferred variant does not contain any coloring oxides.

[0204] B2O3 can have a negative effect on the transparency of the glass-ceramics. Therefore, in an advantageous variant, the content of this component is limited to less than 0.2 mol %, preferably at most 0.1 mol %. A preferred variant does not contain B2O3.

[0205] According to one advantageous embodiment of the invention, the composition does not contain any other ingredients than those mentioned above.

[0206] According to an advantageous embodiment of the invention, the glass ceramic or green glass according to the invention consists in particular of at least 90 mol %, more preferably at least 95 mol %, most preferably at least 99 mol % of the above-mentioned components, or in particular of the components SiO, AlO, LiO, PO, R0, RO and a nucleating agent.

[0207] According to an advantageous development of the glass ceramic, the glass ceramic is substantially free of one or more glass components selected from the group consisting of MgO, ZnO, PbO, B2O3, CrO3, F, Cd compounds.

[0208] According to the present invention, the expressions "free of X" or "free of component X" mean that the glass-ceramic is substantially free of this component X, i.e., such component is present at most as an impurity in the glass and is not added to the composition as an individual component. With regard to impurities, particularly MgO and / or ZnO, in the MgO-free and / or ZnO-free variants, it is desirable not to exceed a limit of 0.03 mol %, preferably 0.01 mol %, for each single component. For other glass components, higher impurity contents are possible, up to 0.1 mol %, preferably up to 0.05 mol %, advantageously up to 0.01 mol %, advantageously up to 0.005 mol %, and advantageously up to 0.003 mol % for some components. Here, X represents an optional component, such as PbO. These limits do not apply to fining agents, for which separate impurity limits are described above.

[0209] The glass-ceramics according to the present invention have a high-quartz solid solution as the predominant crystalline phase. The predominant crystalline phase is the crystalline phase that accounts for the largest volume percentage of the crystalline phase. The high-quartz solid solution is a metastable phase whose composition and / or structure change or transform into another crystalline phase depending on the crystallization conditions. The high-quartz solid solution has very low thermal expansion, or even decreases with increasing temperature. In one advantageous embodiment, the crystalline phase does not include β-spodumene or keatite.

[0210] Advantageous embodiments of the LAS glass ceramics have a crystalline phase content of less than 70% by volume and / or preferably more than 45% by volume. The crystalline phase consists of a high-quartz solid solution, also known as β-eucryptite solid solution. The average crystallite size of the high-quartz solid solution is advantageously <100 nm, in particular <80 nm, preferably <70 nm. The small crystallite size makes the glass ceramic transparent and also allows it to be polished more easily. In a particularly advantageous variant, the average crystallite size of the high-quartz solid solution may be ≦60 nm, in particular ≦50 nm. The crystalline phases, their content, and the average crystallite size are determined by X-ray diffraction analysis, as is known.

[0211] According to one embodiment of the present invention, transparent glass-ceramics are produced. Transparency allows for better evaluation of many of the properties of such glass-ceramics, particularly, of course, their internal quality. The glass-ceramics according to the present invention are transparent, i.e., have a net transmittance of at least 70% in the wavelength range from 350 to 650 nm. B2O3 and / or a high fluorine content can reduce transparency. Therefore, an advantageous variant does not contain one or both of the aforementioned components. Furthermore, the glass-ceramics produced within the scope of the present invention are non-porous and crack-free. Within the scope of the present invention, "non-porous" means a porosity of less than 1%, preferably less than 0.5%, and more preferably less than 0.1%. Cracks are gaps, i.e., discontinuities, in an otherwise continuous microstructure.

[0212] To enable the production of uniform glass-ceramics in large-scale production plants, the processing temperature Va of the green glass on which the glass-ceramic is based (and thus of the glass-ceramic) is advantageously at most 1330°C, preferably at most 1320°C. Some advantageous variants can have a processing temperature of at most 1310°C or at most 1300°C or less than 1300°C. The processing temperature Va is the temperature at which the melt is heated to 10 4 This is the temperature at which the glass-ceramic has a viscosity of 1000 dPa. Homogeneity refers in particular to the uniformity of the CTE of the glass-ceramic over a large volume and the low number, and preferably absence, of inclusions such as bubbles or particles. This is a quality characteristic of glass-ceramics and a prerequisite for their use in EUVL precision components, especially very large ones.

[0213] The processing temperature is determined by the composition of the glass-ceramic. In particular, SiO2, a glass network former, is considered to be an important component for increasing the viscosity and therefore the processing temperature. Therefore, the maximum SiO2 content should be selected in accordance with the above-mentioned regulations.

[0214] CTE The glass-ceramics according to the invention exhibit zero expansion (see Tables 1a and 1b), i.e., have an average coefficient of thermal expansion CTE in the range 0-50°C of at most 0±0.1×10 -6 / K. In some advantageous variations, the average CTE in the range of 0 to 50°C is at most 0±0.05×10 -6 In certain applications, the average CTE over a wider temperature range, for example, from -30°C to +70°C, especially from -40°C to +80°C, can be up to 0±0.1×10 -6 / K. Further details regarding the mean and differential CTE have already been given above in connection with the EUVL precision component according to the invention; this disclosure is fully included in the description of the glass-ceramics.

[0215] Thermal Hysteresis In the context of the present invention, glass ceramics are hysteresis-free since they have a thermal hysteresis of less than 0.1 ppm in the temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, and particularly preferably at least 10°C to 35°C (see Figures 10 and 11 and Figures 31 to 33). In an advantageous embodiment, this hysteresis-free property exists in the temperature range of at least 5°C to 35°C, in particular at least 5°C to 45°C, in particular at least >0°C to 45°C, preferably at least -5°C to 50°C. Particularly preferably, the temperature range over which the hysteresis-free property is exhibited is even wider, so that the material or component is also suitable for applications at temperatures up to, and advantageously even above, 100°C.

[0216] Further details regarding thermal hysteresis have already been given above in connection with the EUVL precision components according to the invention, the disclosure of which is fully included in the description of glass-ceramics.

[0217] Figures 2 to 9 show thermal expansion curves for known LAS glass-ceramics, all of which were generated by the same method as for the LAS glass-ceramics according to the invention (Figures 10 and 11, and Figures 31 to 33). For the materials shown in Figures 3 to 8, the cooling curves (dashed lines) and heating curves (dotted lines), respectively, clearly deviate from each other, especially at low temperatures. At 10°C, the difference is greater than 0.1 ppm, and in some comparative examples, it reaches approximately 1 ppm. This means that the materials exhibit significant thermal hysteresis, at least in the temperature range of 10°C to 35°C.

[0218] The tested LAS glass-ceramics shown in Figures 2-5 (Comparative Examples 7, 9, and 10 in Table 2) all contain MgO and ZnO and exhibit thermal hysteresis over a wide temperature range between 10°C and 35°C. Figures 6 and 7 show the hysteresis curves for LAS glass-ceramics containing ZnO but not MgO (Comparative Examples 8 and 14 in Table 2). Both materials exhibit a significant increase in thermal hysteresis below 15°C. Figure 8 shows the hysteresis curve for LAS glass-ceramics containing MgO but not ZnO (Comparative Example 15 in Table 2). This material also exhibits a significant increase in thermal hysteresis below 15°C. As can be seen in Figure 9, this known material (Comparative Example 1 in Table 2) does not exhibit thermal hysteresis, but the steep transition in the curve indicates that it is not a zero-expansion material. The average CTE here is -0.24 ppm / K.

[0219] The LAS glass ceramics according to the present invention have very low MgO and / or ZnO contents, or preferably are free of MgO and ZnO. As can be seen in Figures 10 and 11 and Figures 31-33, the heating and cooling curves overlap at least in the temperature range of 10°C to 35°C. However, these materials are not only hysteresis-free in the 10°C to 35°C range, but also in the temperature range of at least 5°C to 35°C, particularly in the temperature range of at least 5°C to 45°C, and especially in the temperature range of at least >0°C to 45°C. Example 7 in Figure 11 is also hysteresis-free at least in the temperature range of -5°C to 50°C, preferably at higher and lower temperatures.

[0220] Parameter F It can be advantageous for the expansion curve of an LAS glass ceramic to exhibit a flat profile in the temperature range from 0°C to 50°C. The parameter F, which is an indicator of the flatness of the expansion curve, can be used to express the extent to which the profile of the thermal expansion curve deviates from a simple linear profile, where F = TCL(0;50°C) / |Expansion(0;50°C)|. Therefore, it is advantageous for the parameter F to be <1.2, preferably <1.1, and preferably at most 1.05. The closer the parameter F is to 1, the flatter the profile of the expansion curve. Looking at Figures 12, 13, 18, and 34, it can be seen that advantageous embodiments of LAS glass ceramics exhibit a flat profile of the expansion curve (here, F = 1) both in the temperature range from 0°C to 50°C and in the wider temperature range from -30°C to 70°C. In comparison, Figures 14 to 17 and 19 show that known materials exhibit a much steeper and more curved profile of the expansion curve in this temperature range.

[0221] Alternative parameter f T.i. In some advantageous variants, depending on the field of application of the component, a flat progression of the expansion curve may also be desired for other temperature intervals (Ti), in particular for the temperature ranges (20; 40), (20; 70) and / or (-10; 30). T.i.has units (ppm / K), and f T.i. =TCL (T.i.) / is defined by the width of the temperature interval (Ti), where Ti represents the respective temperature interval. (20;40) <0.024 ppm / K and / or alternative parameter f (20;70) <0.039 ppm / K and / or alternative parameter f (-10;30) It is advantageous to have <0.015 ppm / K, which can be seen in FIGS.

[0222] Parameter F and alternative parameter f T.i. Further details regarding the relative length change (dl / l0) in the temperature ranges 20°C-30°C, 20°C-35°C and / or 20°C-40°C have already been given above in connection with the EUVL precision component according to the invention, the disclosure of which is fully included in the description of the glass-ceramics.

[0223] Further advantageous features 20 and 21, as well as 37-41, show that advantageous embodiments of LAS glass-ceramics have a CTE plateau. Glass-ceramics with a plateau over a wide temperature range, i.e., optimized zero expansion, have a flat progression of the expansion curve and a constant value of the parameter F and the alternative parameter f. T.i. provides the same advantages as already mentioned above in connection with

[0224] The temperature range T has a plateau close to 0 ppm / K, i.e., a width of at least 40 K, in particular at least 50 K. P Advantageously, the differential CTE at T is less than 0±0.025 ppm / K. P Advantageously, the temperature interval T has a width of at least 40 K. P The differential CTE at may be less than 0±0.015 ppm / K.

[0225] 22, 23 and 26, as well as 42 and 43, already mentioned above in connection with EUVL precision components, show that advantageous embodiments of LAS glass ceramics have CTE curves with advantageously very low slopes over a wide temperature range. The CTE-T curves have a slope of ≦0±2.5 ppb / K in a temperature interval with a width of at least 30 K. 2 , preferably ≦0±2 ppb / K 2 , preferably ≦0±1.5 ppb / K 2 , particularly preferably ≦0±1 ppb / K 2 , and in some variants ≦0±0.8 ppb / K 2 , and according to certain variants, further ≦0±0.5 ppb / K 2 It is advantageous to have a slope of

[0226] The low slope feature can be present with or without the formation of a favorable CTE plateau.

[0227] The glass ceramics according to the invention or advantageous EUVL precision parts made of the glass ceramics according to the invention preferably have an elastic modulus determined in accordance with ASTM C 1259 (2021) of 75 GPa to 100 GPa, in particular 80 GPa to 95 GPa. As already explained above, the use of such advantageous EUVL precision parts in so-called high NA EUVL systems or other EUVL systems with increased wafer throughput is advantageous, since a higher elastic modulus allows for increased dynamic positioning accuracy, in particular of photomasks.

[0228] Further advantageous details regarding the CTE plateau, the slope of the CTE-T curve, the zero crossing of the CTE-T curve, and the adaptation of the CTE or expansion curve to different application temperatures by varying the ceramization temperature and / or ceramization time (see, e.g., Figures 24, 25, 44, 45), etc., have already been described above in connection with the EUVL precision components according to the invention, and this disclosure is fully included in the description of the glass-ceramics.

[0229] Example Tables 1a, 1b and 2 show the compositions of examples of glass-ceramics according to the invention, in particular for EUVL precision parts, and the compositions of comparative examples, as well as their properties.

[0230] The compositions shown in Table 1a were melted by conventional manufacturing methods from commercially available raw materials such as oxides, carbonates, and nitrates. The green glasses produced according to Table 1a were first ceramized at the maximum temperatures shown for the times shown.

[0231] The production of glass ceramics for precision components, in particular large precision components, is described, for example, in WO 2015 / 124710.

[0232] Table 1a lists 23 examples of the present invention (denoted as Examples) that are hysteresis-free and exhibit zero expansion over at least the temperature range of 10°C to 35°C. Examples 6, 18, 19, and 20 exhibit thermal hysteresis only from about 0°C, while Examples 11, 17, and 23 exhibit it only from -5°C. Examples 7, 12, 14, 15, and 22 are hysteresis-free over the entire temperature range from -5°C to 45°C. Furthermore, the parameter F is <1.2, i.e., the progression of the expansion curves in the temperature range from 0°C to 50°C is advantageously flat in all examples. Furthermore, since the processing temperatures in these examples are ≦1330°C, the glass-ceramics can be produced with high uniformity in large-scale production plants. The processing temperatures shown in Tables 1a, 1b and 2 were determined in accordance with DIN ISO 7884-1 (2014 - Source: Schott Techn. Glas-Katalog).

[0233] In Example 5, after ceramization for 2.5 days at up to 780°C, the average CTE was determined at additional temperature intervals, yielding the following results: CTE(20; 300°C): -0.17 ppm / K, CTE(20; 500°C): -0.02 ppm / K, CTE(20; 700°C): 0.17 ppm / K.

[0234] For Example 7, the average CTE was determined over a temperature range of 19°C to 25°C, and as a result, Example 7 had a CTE (19;25) of -1.7 ppb / K.

[0235] The compositions shown in Table 1b were melted in a conventional manufacturing process using different fining agents or combinations of fining agents from commercially available raw materials such as oxides, carbonates, and nitrates. Within the scope of the present invention, fining agents with significantly reduced or no As2O3 were used. In Example 7b, which was fined with SnO2 and sulfates, 0.19 mol% SO3 was added to the synthesis as Na2SO4, which was equivalent to 0.22 mol% SO4. 2- X-ray fluorescence analysis of the green glasses or glass-ceramics revealed SO3 contents below the detection limit of <0.02 wt. %. The green glasses produced according to Table 1b were first ceramized at the indicated maximum temperatures for the indicated times. As already mentioned above in connection with the figures for Examples 6b and 7b, samples were also produced that were ceramized with other ceramization parameters (in particular different maximum temperatures).

[0236] The production of glass ceramics for precision components, in particular large precision components, is described, for example, in WO 2015 / 124710.

[0237] Table 1b lists 15 examples of the present invention (denoted as "Examples") that are hysteresis-free and exhibit zero expansion at least in the temperature range from 10°C to 35°C. Examples 1b, 8b, and 13b exhibit thermal hysteresis only from about 5°C, while Examples 2b and 9b exhibit thermal hysteresis only from about -5°C. Examples 3b, 5b, 6b, and 7b are hysteresis-free over the entire temperature range from -5°C to 45°C. Furthermore, the parameter F is <1.2, i.e., the progression of the expansion curve in the temperature range from 0°C to 50°C is advantageously flat in all examples. Furthermore, since the processing temperatures in these examples are ≦1330°C, the glass ceramics can be produced with high uniformity in large-scale production plants. The processing temperatures listed in Tables 1a, 1b, and 2 were determined in accordance with DIN ISO 7884-1 (2014 - Source: Schott Techn. Glas-Katalog).

[0238] For Example 7b, after ceramization for 2.5 days at temperatures up to 810°C, the average CTE was determined over additional temperature intervals, yielding the following results: CTE(20; 300°C): +0.13 ppm / K, CTE(20; 500°C): +0.34 ppm / K, CTE(20; 700°C): +0.59 ppm / K.

[0239] For Example 6b and Example 7b, the average CTE was determined over the temperature range of 19°C to 25°C, where Example 6b had a CTE(19:25) of 0.77 ppb / K and Example 7b had a CTE(19:25) of 0.37 ppb / K.

[0240] In Example 10b, a refining treatment was performed using SnO2. Furthermore, nitrates were included as oxidizing agents, and in particular, the components BaO and Na2O were used as nitrate raw materials to adjust the melt to an oxidized state.

[0241] Example 15b was refined with SnO2, which also served as a nucleating agent. An additional nucleating agent was ZrO2.

[0242] Table 2 shows comparative examples (denoted as Comparative Examples). Comparative Examples 1, 2, 5, and 6 have neither MgO nor ZnO, but have an average CTE(0;50) of 0±0.1×10 -6 / K, i.e., these comparative examples are not zero-expansion. Furthermore, Comparative Examples 1 and 2 have processing temperatures above 1330°C. Because these materials are very viscous, they cannot be used to fabricate parts with high uniformity in large-scale production plants.

[0243] Comparative Examples 7 to 13 and 15 all contain MgO and / or ZnO, and most of them have zero thermal expansion. However, these comparative examples exhibit thermal hysteresis far exceeding 0.1 ppm at least in the temperature range of 10°C to 35°C. At room temperature, i.e., 22°C, all comparative examples, except for Comparative Example 14, exhibit thermal hysteresis. Furthermore, although Comparative Example 9 has zero thermal expansion, it has an undesirably steep transition in the expansion curve in the temperature range of 0°C to 50°C, as evidenced by the large value of parameter F.

[0244] In the tables below, if a column for composition data is blank, this means that the ingredient(s) is / are not intentionally added or included.

[0245] Table 3a shows the calculated alternative parameters f for each temperature interval for some advantageous embodiments of the present invention and one comparative example in Table 1a. (T.i.) , which shows that the expansion curves of the Examples in the indicated temperature ranges show a flatter progression than the Comparative Examples, respectively.

[0246] Table 3b shows the calculated alternative parameters f for each temperature interval for some advantageous embodiments of the present invention and one comparative example in Table 1b. (T.i.) , which shows that the expansion curves of the Examples in the indicated temperature ranges show a flatter progression than the Comparative Examples, respectively.

[0247] Table 4a shows the CTE uniformity across part sizes for advantageous parts having a composition according to Inventive Example 7 of Table 1a, demonstrating that the tested parts advantageously have high CTE uniformity in both the temperature range of 0° C. to 50° C. and the temperature range of 19° C. to 25° C. Additionally, the modulus of elasticity (also referred to as elastic modulus) determined in accordance with ASTM C 1259 (2021) is shown.

[0248] Table 4b shows the CTE uniformity across part sizes for advantageous parts having a composition according to Inventive Example 6b of Table 1b, demonstrating that the tested parts advantageously have high CTE uniformity in both the temperature range of 0° C. to 50° C. and the temperature range of 19° C. to 25° C. Additionally, the modulus of elasticity (also referred to as elastic modulus) determined in accordance with ASTM C 1259 (2021) is shown.

[0249] It is clear to those skilled in the art that depending on the application temperature of the glass ceramic or EUVL precision component comprising the glass ceramic, a glass ceramic will be selected that has the desired properties, in particular with regard to thermal hysteresis and / or average CTE and / or CTE uniformity.

[0250] [Table 7-1] [Table 7-2] [Table 7-3] [Table 7-4]

[0251] [Table 8-1] [Table 8-2] [Table 8-3]

[0252] [Table 9-1] [Table 9-2] [Table 9-3]

[0253] [Table 10]

[0254] [Table 11]

[0255] CTE uniformity Each CTE uniformity tested part was manufactured using measures to improve CTE uniformity as described in WO 2015 / 124710.

[0256] First, 28 ml of green glass was prepared according to the composition mentioned in relation to the glass-ceramics of Example 7 in Table 1a and Example 6b in Table 1b. 3 The glass melt was melted in a melting bath at a temperature of approximately 1600°C for several days. During this process, fining gases were generated by the decomposition of As2O3 or Sb2O3, which entrained small gaseous inclusions and homogenized the melt. The fining and subsequent cooling stages further homogenized the glass melt. To facilitate homogenization, the temperature of the bath surface was specifically controlled to induce convection in the melt. During the subsequent cooling stage, which also could take several days, the temperature of the glass melt was reduced to approximately 1400°C, and it was then poured into a mold with a side length of 1.7 m and a height of 500 mm.

[0257] Ceramization was carried out under the following conditions: First, each green glass block (or blank) was heated at a heating rate of 0.5°C / h to a temperature of 630-680°C. The heating rate was then reduced to 0.01°C / h, and the glass was further heated to a temperature of 770-830°C. This temperature was maintained for approximately 60 hours. The blank was then cooled to room temperature at a cooling rate of -1°C / h.

[0258] From the glass ceramics thus produced, blocks were cut after removal of the edge regions, with the following dimensions: - 500×500×100mm - 700×700×200mm - 1400×1400×300mm

[0259] The CTE uniformity of the obtained ceramic block was determined as follows.

[0260] To determine the CTE uniformity (0:50) and CTE uniformity (19:25) of the components, 64 samples were cut from each glass-ceramic component and measured separately. The CTE(0:50) was determined for each of the 64 samples from a component, and the CTE(19:25) was determined for an additional 64 samples. The thermal expansion of the samples was determined using a static method, where the length of each sample was measured at the beginning and end of a specific temperature interval, i.e., 0°C to 50°C or 19°C to 25°C, and the average coefficient of expansion α or CTE was calculated from the difference in length. The CTE is then reported as the average value for this temperature interval, e.g., CTE(0:50) or α(0:50) for the 0°C to 50°C temperature interval, and CTE(19:25) for the 19°C to 25°C temperature interval. The difference between the highest CTE (0;50) and the lowest CTE (0;50) or the highest CTE (19;25) and the lowest CTE (19;25) (peak-to-valley value) was then calculated. The smaller this difference (e.g., 3 ppb), the smaller the CTE variation within the tested component and the higher the CTE uniformity.

[0261] The CTE uniformity determined in the temperature range of 0 to 50°C or 19 to 25°C is summarized in Table 4a and Table 4b.

[0262] [Table 12]

[0263] [Table 13]

Claims

1. An EUVL precision part having an average coefficient of thermal expansion (CTE) of 0±0.1×10 at most in the range of 0 to 50°C. －６ / K, a thermal hysteresis of at least 19° C. to 25° C., preferably at least 10° C. to 25° C., particularly preferably at least 10° C. to 35° C., of <0.1 ppm, a parameter F of <1.2, where F=TCL(0; 50° C.) / |Expansion(0; 50° C.)|, and the EUVL precision component comprises the following components (in mole % on an oxide basis): Yes ２ 60~71 Li ２ O7~9.4 MgO+ZnO 0~<0.6 B ２ O ３ 0~0.1 F 0 to 0.3 P ２ O ５ , R ２ At least one component selected from the group consisting of O and RO, where R ２ O is Na ２ O and / or K ２ O and / or Cs ２ O and / or Rb ２ O, and RO may be CaO and / or BaO and / or SrO; Nucleating agent: 1.5-6 mol % content, where the nucleating agent is TiO ２、 ZrO ２、 Ta ２ O ５ , Nb ２ O ５ , SnO ２ , MoO ３ and W.O. ３ and at least one component selected from the group consisting of 1. An EUVL precision component comprising an LAS glass ceramic, comprising:

2. An EUVL precision part having an average coefficient of thermal expansion (CTE) of 0±0.1×10 at most in the range of 0 to 50°C. －６ / K, and the thermal hysteresis in the temperature range of at least 19°C to 25°C, preferably at least 10°C to 25°C, particularly preferably at least 10°C to 35°C is <0.1 ppm, and the precision component has an alternative parameter f （２０；４０） <0.024 ppm / K, alternative parameter f （２０；７０） <0.039 ppm / K, alternative parameter f （－１０；３０） <0.015 ppm / K. Ｔ．ｉ． and the EUVL precision component comprises the following components (in mole % on an oxide basis): Yes ２ 60~71 Li ２ O7~9.4 MgO+ZnO 0~<0.6 F 0 to 0.3 P ２ O ５ , R ２ At least one component selected from the group consisting of O and RO, where R ２ O is Na ２ O and / or K ２ O and / or Cs ２ O and / or Rb ２ O, and RO may be CaO and / or BaO and / or SrO; Nucleating agent: 1.5-6 mol % content, where the nucleating agent is TiO ２、 ZrO ２、 Ta ２ O ５ , Nb ２ O ５ , SnO ２ , MoO ３ and W.O. ３ and at least one component selected from the group consisting of 1. An EUVL precision component comprising an LAS glass ceramic, comprising:

3. The LAS glass ceramics is Al ２ O ３ in a content of 10 to 22 mol %, preferably 11 to 21 mol %, and / or P ２ O ５ with a content of 0.1 to 6 mol %, preferably 0.3 to 5 mol %, and / or a total of ZnO + MgO with a content of less than 0.5 mol %, preferably 0.3 mol % or less, and / or SiO ２ 3. The EUVL precision part according to claim 1, further comprising: a content of up to 69 mol %, preferably up to 68.5 mol %, and / or CaO in a content of 0.4 to 5 mol %.

4. A maximum of 0±2.5 ppb / K in a temperature range where the CTE-T curve has a width of at least 30 K ２ , especially maximum 0±2 ppb / K ２ , preferably at most 0±1.5 ppb / K ２ , preferably at most 0±1 ppb / K ２ 4. The EUVL precision part according to claim 1, wherein the EUVL precision part has a slope of:

5. The differential CTE of the EUVL precision component has a plateau close to 0 ppm / K, i.e., a temperature range T having a width of at least 40 K, in particular at least 50 K. Ｐ 5. The EUVL precision component according to claim 1, wherein the differential CTE of the EUVL precision component is less than 0±0.025 ppm / K.

6. The EUVL precision component according to any one of claims 1 to 5, wherein the EUVL precision component has a CTE uniformity (0; 50) of at most 5 ppb / K, in particular at most 4 ppb / K, most preferably at most 3 ppb / K and / or a CTE uniformity (19; 25) of at most 5 ppb / K, in particular at most 4.5 ppb / K, in particular at most 4 ppb / K, even more preferably at most 3.5 ppb / K, even more preferably at most 3 ppb / K, even more preferably at most 2.5 ppb / K.

7. 7. The EUVL precision component according to claim 1, wherein the thermal hysteresis is <0.1 ppm at least in the temperature range of 5°C to 45°C, advantageously at least in the temperature range of >0°C to 45°C, preferably at least in the temperature range of -5°C to 50°C.

8. The EUVL precision part has a relative length change (dl / l) of |0.10| ppm or less, preferably |0.09| ppm or less, particularly preferably |0.08| ppm or less, and particularly preferably |0.07| ppm or less in the temperature range of 20°C to 30°C. ０ ) and / or a relative length change (dl / l) of |0.17| ppm or less, preferably |0.15| ppm or less, particularly preferably |0.13| ppm or less, and especially preferably |0.11| ppm or less in the temperature range from 20° C. to 35° C. ０ 8. The EUVL precision part according to claim 1, further comprising:

9. The EUVL precision component has a relative length change (dl / l) of |0.30| ppm or less, preferably |0.25| ppm or less, particularly preferably |0.20| ppm or less, and particularly preferably |0.15| ppm or less in the temperature range of 20°C to 40°C. ０ 9. The EUVL precision part according to claim 1, wherein the EUVL precision part comprises a first surface and a second surface.

10. 10. The EUVL precision part according to any one of claims 1 to 9, wherein the precision part is selected from the group consisting of a photomask or reticle, a photomask substrate or reticle mask blank or mask blank, a photomask support or reticle stage, a mirror, a mirror support and a wafer support or wafer stage, in particular a photomask or reticle and / or a photomask substrate or reticle mask blank or mask blank and / or a photomask support or reticle stage.

11. 11. Use of an EUVL precision component according to any one of claims 1 to 10 in EUVL lithography, in particular as a photomask or reticle, a photomask substrate or reticle mask blank or mask blank, a photomask support or reticle stage, a mirror, a mirror support and / or a wafer support or wafer stage.

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