A glass material, method of making and use thereof

Abstract

The present application relates to a kind of glass materials and its preparation method and application.The composition of the glass material includes: 53-60wt% SiO2, 20-26wt% Al2O3, 3-4wt% Li2O, 1-4wt% ZnO, 0.5-3wt% MgO, 0.2-3wt% RO, 1-2wt% TiO2, 1-2wt% ZrO2, 3-5wt% P2O5, 0.5-3wt% Ln2O3 and 0-2wt% clarifying agent;Wherein, R=at least one of Sr, Ca, Ba;Ln=at least one of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Tb, Er, Tm, Yb, Lu;The clarifying agent is selected from Sb2O3, CeO2 and at least one of combination.

Description

TECHNICAL FIELD

[0001] The present application relates to a glass material and its preparation method and application, in particular to an ultra-fine crystal extremely low expansion transparent microcrystalline glass and its preparation method, and particularly to an ultra-low microcrystalline glass for an optical system of an EUV lithography machine and a workpiece table and a mask table and its preparation method. BACKGROUND

[0002] Transparent ultra-low expansion glass materials have been widely used in optical systems of workpiece tables, mask tables and optical objective systems in lithography machines. In particular, the requirements for ultra-low expansion glass materials in optical systems are very high, in addition to the requirement of extremely low thermal expansion coefficient ≤ 10 ppb / K, the requirements for internal defects and processability are also very high. Extreme ultraviolet lithography (EUVL) is a microelectronic lithography technology using EUV rays with a wavelength of 11-14 nm as an exposure light source, which is suitable for mass production of integrated circuits with a feature size of 32 nm and finer line width. Therefore, different i-line to DUV lithography machine transmission type optical system design schemes, EUV lithography machines use 6 or 8 mirror reflection type exposure systems to achieve chip production of 3 nm and below, and all optical parts use multilayer coated aspherical reflective optical elements. Moreover, in order to meet the quality requirements of lithography imaging, the wavefront aberration of the EUVL optical system needs to be controlled within 1 nm. The wavefront aberration needs to be carefully distributed to each detail factor affecting the imaging quality, such as the mirror substrate, the film thickness, etc. Since the medium and high frequency roughness of the working surface of the element directly affects the contrast of the image surface and the system energy transmission, the surface shape precision and roughness of the element need to reach deep sub-nanometer level. Germany Zeiss company has developed for 20 years under the demand of EUV lithography machine developed by ASML company in the Netherlands, with the improvement and improvement of the requirements of wavefront aberration, element surface roughness and multilayer film thickness, the optical processing, adjustment and coating technology of EUVL is becoming mature. The optical element surface error and medium and high frequency roughness processing precision of large aperture EUVL element reaches 0.1 nm rms, and the wavefront aberration of the EUV optical system reaches the diffraction limit.

[0003] At present, high-quality ultra-low expansion transparent glass materials used in lithography machine systems are divided into two categories: microcrystalline ultra-low expansion transparent glass and amorphous ultra-low expansion microcrystalline glass.

[0004] The microcrystalline ultra-low expansion glass material is a Li2O-Al2O3-SiO2 system ultra-low expansion transparent microcrystalline glass with nano β-quartz solid solution as a main crystal phase. The grain size of the precipitated β-quartz solid solution phase is 50-80 nm, which is 1 / 10 of the wavelength of visible light. The refractive index of the crystal phase is close to the refractive index of the glass, so the light transmittance in the visible light and infrared light range is high. The volume fraction (70% or more) of the negative expansion β-quartz solid solution and the volume fraction of the remaining glass liquid with positive expansion can be well matched to form a near ultra-low expansion coefficient (7-20 ppb / K). Due to the characteristics of nearly zero thermal expansion, excellent three-dimensional overall uniformity, good processing performance, polishing to extremely high precision, good film plating performance, low chemical helium permeability, excellent chemical stability, etc., the ultra-low expansion transparent microcrystalline glass material is a core substrate material of the mask frame system of the DUV, EUV photoetching machine, and carries out the work of wafer pretreatment and exposure. At present, the microcrystalline ultra-low expansion microcrystalline glass material for photoetching machine adopts the ZERODUR® brand of Germany Schott Company Expansion Class 0SPECIAL brand and ZERODU The thermal expansion coefficients of the ultra-low expansion microcrystalline glass materials of the EXTREME brand can be 7 ppb / K and 10 ppb / K (0-50℃) respectively (related patent numbers WO2015124710(A1), DE102010002188(A1)).

[0005] Table 1 is a performance comparison table of ultra-low expansion transparent microcrystalline glass materials of different companies

[0006]

[0007] Amorphous ultra-low expansion glass is a kind of titanium silicate TiO2-SiO2 low expansion glass (related patent number WO20141085529 A1) made by the same vapor deposition process as the Corning ULE system, whose thermal expansion coefficient is very close to 0 ppb / K. This glass is designed to meet the mask requirements of EUVL application and as an optical substrate for ultraviolet lithography. At the same time, Japan Asahi and Nikon have related patent layout in this regard (CN 104395248 B and CN102421713 A). The transition of lithography technology from 193 nm to 13.4 nm lithography requires a major design change from refractive to reflective in the step optical device. In reflective optics, the substrate material should be a pure passive material. The incident light should be reflected from the multilayer coating of the optical device and the photomask, without introducing any mechanical or optical distortion caused by the underlying substrate. In order to minimize the distortion caused by small temperature changes and meet the strict EUVL specification, the substrate must have a near-zero thermal expansion coefficient (CTE, ppb / K level) and a low peak-to-valley (P-V) CTE variation. Currently successfully applied in the optical system designed by Zeiss Company for the new generation of ASML Company EUV lithography machine 3400.

[0008] Table 2 Corning's ultra-low expansion glass material performance table

[0009]

[0010] Research shows that the main reason why microcrystalline ultra-low expansion glass material represented by Germany Schott Company cannot be applied to optical reflective elements in EUV lithography machine is two: first, the mechanical properties of microcrystalline glass material such as elastic modulus and Poisson's ratio are better than ULE glass, so the ion beam polishing process is slower; second, microcrystalline glass is composed of 50-80 nm β-quartz solid solution phase and residual glass phase. Due to the different processing rates of ion beam on the two phases, it is difficult to achieve the 0.12 nm rms required by EUVL, with a high frequency surface roughness of 0.5-0.7 0.12 nm rms; third, most of the ultra-low expansion microcrystalline glass contains B2O3, Na2O and K2O and other components that are not conducive to the coating process. SUMMARY

[0011] The present application aims to provide a kind of EUVL optical lithography machine optical reflection element with ultrafine crystal extremely low expansion transparent microcrystalline glass material, it has extremely low ± (0.5 ~ 10) ppb / K (-50 ~ 150 DEG C) thermal expansion coefficient, high optical property and excellent performance uniformity, 5 ~ 10nm β-quartz solid solution Li2 O-Al2 O3-SiO2 system microcrystalline glass, can meet the application requirements of EUVL optical lithography machine optical reflection element to basic material.

[0012] Another purpose of the present application is to solve the above problems and provide a microcrystalline glass with extremely low expansion characteristics and a manufacturing method of the microcrystalline glass element.

[0013] In a first aspect, in order to realize the ultra-low expansion transparent microcrystalline glass material for EUV mirror material with excellent ultra-low expansion performance and ion beam processability, the present application provides a glass material, the composition of the glass material comprises: 53 ~ 60wt% SiO2, 20 ~ 26wt% Al2O3, 3 ~ 4wt% Li2O, 1 ~ 4wt% ZnO, 1 ~ 3wt% MgO, 0.2 ~ 2wt% RO, 1 ~ 2wt% TiO2, 1 ~ 2wt% ZrO2, 3 ~ 5wt% P2O5, 0.5 ~ 3wt% Ln2O3 and 0 ~ 2wt% fining agent; wherein, R = at least one of Sr, Ca and Ba; Ln = at least one of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Tb, Er, Tm, Yb and Lu; the fining agent is selected from at least one of Sb2O3, CeO2 and combination.

[0014] Preferably, the composition of the glass material comprises: 55 ~ 60wt% SiO2, 20 ~ 25wt% Al2O3, 3 ~ 4wt% Li2O, 2 ~ 4wt% ZnO, 1 ~ 3wt% MgO, 1 ~ 2wt% RO, 1 ~ 2wt% TiO2, 1 ~ 2wt% ZrO2, 3 ~ 4wt% P2O5, 0.5 ~ 3wt% Ln2O3 and 0.5 ~ 2wt% fining agent.

[0015] Preferably, SiO2+Al2O3+Li2O+MgO+ZnO = 85 ~ 90wt%; Li2O+MgO+ZnO = 6 ~ 8wt%, Li2O / (MgO+ZnO) = 1.1 ~ 1.5.

[0016] Wherein Ln = at least three of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Er, Tm, Yb and Lu; the composition of the glass material does not contain PbO, Bi2O3, Na2O, K2O and As2O3.

[0017] In a second aspect, the present application provides a low-expansion transparent glass-ceramic material, wherein the low-expansion transparent glass-ceramic material is obtained by subjecting the above glass material to a crystallization treatment, and wherein the crystalline phase of the low-expansion transparent glass-ceramic material comprises a β-quartz solid solution phase.

[0018] Preferably, the low-expansion transparent glass-ceramic material does not contain PbO, Bi2O3, Na2O, K2O and As2O3.

[0019] Preferably, the crystalline phase has a crystal grain size of 5-10 nm, and the content of the crystalline phase is 70-80 vol%.

[0020] Preferably, the low-expansion transparent glass-ceramic material has an average thermal expansion coefficient of 0.5-10 ppb / ℃, an elastic modulus of 85-91 GPa, and a Poisson's ratio of 0.245-0.255.

[0021] Preferably, the low-expansion transparent glass-ceramic material has the following properties: an elastic modulus of 85-91 GPa, an ion beam processing high frequency roughness of less than 0.20 nm rms, a transmittance of more than 85% in the wavelength range of 500-1500 nm, and an ultra-low thermal expansion coefficient of ±(0.5-10) ppb / K (0-50℃) and excellent thermal expansion coefficient uniformity of ±(0.5-10) ppb / K (0-50℃) under the crystallization treatment at 690-720℃ for 6-24 hours.

[0022] Preferably, the crystallization treatment has the following conditions: a temperature of 680-740℃ and a holding time of 6-24 hours.

[0023] Preferably, the crystallization treatment is accompanied by rotation, and the rotation speed is 0.05-1 revolutions per minute.

[0024] Preferably, the heating rate and the cooling rate of the crystallization treatment are both 0.01-3℃ / min.

[0025] Preferably, the crystallization treatment has the following conditions: first holding at 300-400℃ for 6-24 hours, then holding at 500-550℃ for 6-24 hours, then holding at 680-740℃ for 6-24 hours, and finally cooling to 200-300℃, then powering off and cooling to room temperature.

[0026] In another aspect, the present application provides a method for preparing a glass material, comprising:

[0027] (1) mixing a Si source, an Al source, a Li source, a Zn source, a Mg source, a Ti source, a Zr source, a P source, an R source, an Ln source and a fining agent, and then subjecting the mixture to melting-homogenization and cold leaching to obtain glass slag;

[0028] (2) the obtained glass scrap is subjected to melting, homogenization, fining and annealing to obtain the glass material.

[0029] In order to realize the melting and forming of the homogeneous, defect-free (pore, solidification, forming stripe) base glass of the ultra-low expansion transparent glass-ceramic material for the EUV mirror material, the present application repeatedly carries out deep forming process test research, and obtains a preparation method of the ultra-low expansion transparent glass-ceramic material in a gradient melting process, that is, the melting, stirring homogenization and fining three stages in the glass melting process are carried out in different temperature furnaces.

[0030] Preferably, the Si source is silicon oxide or / and quartz glass, and the purity of the Si source is ≥ 99.9%;

[0031] The Al source is at least one of AlPO4 and Al(OH)3, and the purity of the Al source is ≥ 99.9%;

[0032] The Li source is Li2O or / and lithium carbonate, and the purity of the Li source is ≥ 99.9%;

[0033] The Zn source is ZnO, and the purity is ≥ 99.9%;

[0034] The Mg source is MgO, and the purity is ≥ 99.9%;

[0035] The Ti source is TiO2, and the purity is ≥ 99.9%;

[0036] The Zr source is ZrO2, and the purity is ≥ 99.9%;

[0037] The P source is P2O5 or / and AlPO4, and the purity of the P source is ≥ 99.9%;

[0038] The R source is at least one of the oxide of R, the carbonate of R, and the nitrate of R, and the purity of the R source is ≥ 99.9%;

[0039] The Ln source is at least one of the oxide of Ln, the carbonate of Ln, and the nitrate of Ln, and the purity of the Ln source is ≥ 99.9%.

[0040] Preferably, in step (1), the temperature of the melting-homogenization is 1550-1600℃, and the holding time is 2-6 hours.

[0041] The cold extraction system is that the glass melt is poured into a roller gate machine for cold extraction treatment.

[0042] Preferably, the heating rate and the cooling rate of the melting are both 2-20℃ / min.

[0043] Preferably, the number of operations of the melting-homogenizing and cold extraction is 1-4, preferably 1-3.

[0044] Preferably, in step (2), the melting, homogenizing, clarifying and annealing are carried out in four crucibles respectively, and the heating and cooling rates are both 2-20℃ / min.

[0045] The temperature of the melting is 1575-1640℃, and the holding time is 6-24 hours.

[0046] The temperature of the homogenizing is 1575-1640℃, and stirring is carried out simultaneously during the homogenizing, the stirring system comprises high-speed stirring at 30-60rpm and low-speed stirring at 15-25rpm, the total time of the homogenizing and stirring is 6-24 hours, and the ratio of the high-speed stirring time to the low-speed stirring time is 1:(0.2-0.5).

[0047] The temperature of the clarifying is 1400-1500℃, and the holding time is 4-12 hours.

[0048] The temperature system of the annealing is 600-700℃, and the holding time is 12-48 hours.

[0049] Preferably, in step (2), the melting, homogenizing, clarifying and annealing are carried out in four crucibles respectively, and the heating and cooling rates are both 2-20℃ / min.

[0050] The crucible used for the melting is a platinum-rhodium crucible or a quartz crucible.

[0051] The crucible used for the homogenizing is a platinum-rhodium crucible or a quartz crucible.

[0052] The crucible used for the clarifying is a quartz crucible or a graphite crucible.

[0053] The crucible used for the annealing is a graphite crucible, and the structure design can realize no machining or less machining of the element.

[0054] In a fourth aspect, the application provides a glass material for use in an optical reflecting element of an EUVL photolithography machine.

[0055] In a fifth aspect, the application provides an application of an extremely low-expansion transparent microcrystalline glass material in an optical reflecting element of an EUVL photolithography machine.

[0056] The application has the following advantages:

[0057] The present application is according to the application requirement of EUV photoetching machine to optical material and processability, design a kind of with ppb / K level 0.5-10nm beta-quartz solid solution phase as main crystal phase of ultra-low expansion transparent microcrystalline glass material and its element preparation method, its average linear expansion coefficient is ± (0.5-10) ppb / K (0-50 DEG C), and thermal expansion uniformity is also controlled in ± (0.5-10) ppb / K (0-50 DEG C) range, and its basic performance can realize to Germany Schott company Expansion Class 0SPECIAL brand (10ppb / K) and ZERODU Expansion Class 0EXTREME (7ppb / K) brand ultra-low expansion microcrystalline glass material is replaced, and part performance has surpassed the ultra-low expansion microcrystalline glass material of Schott company.And, according to the preferred mode of the present application, ultra-low expansion transparent microcrystalline glass material can be obtained, which is composed of beta-quartz solid solution phase crystal particles with a particle size of 0.5-10 nm and residual glass phase, with a crystal phase content of ≥70%, an elastic modulus of 86-91 GPa, a Poisson's ratio of 0.245-0.255, a microcrystallization system of 690-720 DEG C for 9-15 hours, an ultra-low thermal expansion coefficient of ± (0.5-10) ppb / K (0-50 DEG C), a surface error roughness of ≤0.20 nm rms controllable by ion beam polishing (IBF) and other processing technologies, a transmittance of higher than 85% in the 500-1500 nm wave band, and a microcrystalline glass surface and film layer firmly combined after coating, which can completely meet the basic material requirements of optical elements in extreme ultraviolet lithography (EUVL) optical systems and worktable and mask table applications in all series of photoetching machines;

[0058] The present application has obvious advantages in formula design, melting forming process, microcrystallization process and formula design-preparation process compatibility technical solutions, and has the following specific beneficial effects: 1. Firstly, aiming at the problems of high thermal expansion coefficient, poor processability, easy diffusion of coating ions and the like, the present application uses high ion field strength rare earth oxides to partially or completely replace the alkali earth metal oxides (CaO, BaO, SrO) commonly used as solvents in the base glass of the ultra-low expansion microcrystalline glass, alkali metal oxides (K2O, Na2O) and B2O3 components, and combines the introduction of high-entropy rare earth oxides (component content ≥3) to compress the glass network structure, thereby regulating the glass crystallization behavior, improving the compactness of the residual glass network structure, reducing the temperature sensitivity of the residual glass network structure, and further obtaining the ultra-low expansion coefficient microcrystalline glass material. In addition, in order to reduce the melting temperature, the present application selects raw materials with low melting point, low decomposition temperature and high reactivity;

[0059] 2、The present application optimizes the traditional center / eccentric stirring + casting forming process in melting and forming process, designs gradient melting process: the glass melting-micro-channel leakage material homogenization-clearing stage is carried out in different crucibles respectively, and the homogeneous, defect-free matrix glass forming meets the harsh requirements of manufacturing EUV optical device;

[0060] 3、The present application also optimizes the microcrystallization process, selects TiO2+ZrO2+P2O5 ternary system as nucleating agent, and controls its content, and there is no nucleation process in the microcrystallization process, and through ultra-low heating rate and low temperature crystallization temperature, the microcrystalline glass element has ultra-low thermal expansion coefficient 0.5-2*10 -8 / K (0-50℃) in the 690-720℃ holding time range of 9-15 hours, so that the microcrystalline glass element has high thermal expansion coefficient uniformity;

[0061] 4、According to the basic properties of glass formula, high-temperature glass melt viscosity characteristics and the like, the present application uniquely designs melting-forming-annealing-crystallization process and the corresponding equipment, and breaks through the whole chain of raw material-component design-key process and equipment design of ultra-low expansion microcrystalline glass material;

[0062] 5、According to the characteristics of the material, the present application designs the process and equipment, simplifies the process, shortens the production cycle, and produces high-quality ultra-low expansion microcrystalline glass material. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 The TEM diagram of the extremely low expansion transparent microcrystalline glass material of example 1 is shown in the figure, and it can be seen from the figure that the microcrystalline glass of example 1 precipitates a crystal phase (white particles) with a particle size of 5-10nm and uniformity;

[0064] Figure 2 The XRD diagram of the extremely low expansion transparent microcrystalline glass material of example 1 under different crystallization systems is shown in the figure, and it can be seen from the figure that only β-quartz solid solution is precipitated in the microcrystalline glass with the change of the microcrystallization system, and the diffraction peak intensity basically does not change with the change of the crystallization system, which shows that the crystallization window (including temperature and time) of the ultra-low expansion microcrystalline glass can be effectively expanded through the control of rare earth ions, and the design purpose of the present application is achieved;

[0065] Figure 3 The thermal expansion coefficient diagram of the extremely low expansion transparent microcrystalline glass material of example 1 under different crystallization systems is shown in the figure, and it can be seen from the figure that the thermal expansion coefficient of the microcrystalline glass changes in the range of 0-50℃, and the change trend is compared, and they are all in the range of ±(0.5-10ppb) / K, which is caused by the ultra-fine crystal and the change of the phase and the content, and the requirement of the present application for the control of the thermal expansion coefficient is achieved;

[0066] Figure 4 The XRD patterns of the ultra-low expansion transparent glass-ceramics after different crystallization regimes in Example 4 show that only β-quartz solid solution is precipitated in the glass-ceramics as the crystallization regime changes, and the diffraction peak intensity remains essentially unchanged. This indicates that the control of rare earth ions can effectively expand the crystallization window (including temperature and time) of ultra-low expansion glass-ceramics, achieving the design objective of this patent.

[0067] Figure 5 Figure 4 shows the thermal expansion coefficient of the ultra-low expansion transparent glass-ceramics material after different crystallization systems. As can be seen from the figure, the thermal expansion coefficient of the glass-ceramics varies between 0 and 50°C, all within the range of ±(0.5-10 ppb) / K. This is due to the fact that its ultrafine grains and phase changes and content remain unchanged, achieving the thermal expansion coefficient regulation of this patent.

[0068] Figure 6 This is a TEM image of the ultra-low expansion transparent glass-ceramics material of Comparative Example 1. As can be seen from the image, without rare earth ion control, the glass precipitates rod-like grains with a diameter of >10nm;

[0069] Figure 7 This is the XRD pattern of the ultra-low expansion transparent glass-ceramics material of Comparative Example 1. As can be seen from the figure, with the increase of crystallization temperature and holding time, in addition to the diffraction peak corresponding to the β-quartz solid solution, a miscellaneous peak appears at ~23°, and the intensity of the diffraction peak at ~19° also fluctuates. This indicates that the crystallization of the glass-ceramics without rare earth ion control is easily affected by the crystallization system, resulting in changes in its thermal expansion coefficient.

[0070] Figure 8 Comparative Example 1 shows the thermal expansion coefficient diagram of extremely low expansion transparent microcrystalline glass materials under different crystallization systems. It can be seen from the figure that the thermal expansion coefficient of microcrystalline glass has a relatively large change trend with the change of crystallization system (temperature increase and holding time), which exceeds the range of ± (0.5 ~ 10ppb) / K. DETAILED DESCRIPTION

[0071] The present invention is further described below through the following embodiments. It should be understood that the following embodiments are only used to illustrate the present invention, rather than to limit the present invention.

[0072] In the present application, the glass component of the glass material comprises: a base component of 55-60wt% SiO2, 20-25wt% Al2O3, 3-4wt% Li2O, 2-4wt% ZnO, 1-3wt% MgO, a fluxing agent of 1-2wt% R'O (R' = Sr, Ca, Ba), a nucleating agent of 1-2wt% TiO2, 1-2wt% ZrO2, 3-4wt% P2O5, an ultra-low expansion control agent of 0.5-3wt% rare earth oxide Ln2O3 (Ln = Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Er, Tm, Yb, Dy, Lu) of three or more kinds; and 0-2wt% clarifying agent selected from at least one of Sb2O3, CeO2 and combinations. The present application does not contain B2O3, R"2O (R" = Na, K and other components that are not conducive to the plating process).

[0073] In the optional embodiment, the composition is explained as follows:

[0074] In the Li2O-Al2O3-SiO2 system ultra-low expansion transparent glass-ceramic composition, Li2O-Al2O3-SiO2 is the main component of the β-quartz solid solution phase, so the composition ratio of the three is the core of the glass-ceramic having ultra-low expansion coefficient and optical performance. In the present application, the β-quartz solid solution refers to the introduction of Al 3+ ion replacement Si 4+ and the introduction of interstitial ions Li + (occupying the tetrahedral vacancy in the β-quartz phase structure), Mg 2+ (occupying the octahedral vacancy in the β-quartz phase structure), Zn 2+ (occupying the tetrahedral vacancy in the β-quartz phase structure) balance the charge. Therefore, the main components of the glass in the present application are SiO2, Al2O3, Li2O, MgO and ZnO, wherein SiO2+Al2O3+Li2O+MgO+ZnO = 85-90wt%;

[0075] Li2O+MgO+ZnO = 6-8wt%, Li2O / (MgO+ZnO) = 1.1-1.5;

[0076] SiO2 as a glass network former oxide, if the content is less than 55wt%, on the one hand it will reduce the mechanical strength of the base glass, the crystal size will be large after crystallization, the SiO2 component in the residual glass phase is too low, on the other hand, too low content will also lead to the decrease of the transparency of the glass, the parent glass is easy to be devitrified; but when the content of SiO2 exceeds 60wt%, it will increase the high temperature viscosity of the glass melt, leading to the failure of the elimination of stripes, bubbles and stones in the glass. Therefore, the content of SiO2 in the present application is preferably 55-60wt%, more preferably 56-59wt%.

[0077] Al2O3 as glass network intermediate oxide, can reduce the tendency of glass crystallization, improve the chemical stability of glass, thermal stability, mechanical strength, hardness and refractive index. When the amount of > 20wt% or more, the melting of the base glass becomes easy, so the homogeneity of the resulting glass-ceramics is improved, and the chemical durability of the glass-ceramics is also good. While the amount of ≤ 26wt% or less, the base glass has good devitrification resistance, and the mechanical strength is improved. Therefore, the content of Al2O3 in the present application is preferably 20-26wt%, more preferably 22-24wt%.

[0078] The total content of SiO2 and Al2O3 directly affects the melting of the glass, considering the requirements as the main crystal phase component and the properties of the residual glass phase after crystallization. Therefore, in the present application, Al2O3 + SiO2 = 78-83wt%, SiO2 / Al2O3 = 2.3-2.7.

[0079] Li2O, MgO, ZnO as one of the necessary components of β-quartz solid solution phase, can also play a fluxing effect, MgO and ZnO improve the mechanical properties and chemical stability of the glass. But the content is too high, on the one hand, the matrix glass crystallization ability is enhanced, the grain size is too large, affecting the transparency of the material. Therefore, in the present application, Li2O + MgO + ZnO = 6-8wt%, Li2O / (MgO + ZnO) = 1.1-1.5.

[0080] Alkaline earth metal oxides CaO, BaO and SrO as glass structure network outer oxide, have good fluxing effect, the introduction of glass can reduce the melting temperature and significantly improve the clarifying effect, reduce the crystallization ability. In glass-ceramics, they remain in the residual glass phase, but in order to ensure the hardness of the glass-ceramics, the content should not be too high, this project will use rare earth oxides to partially replace alkaline earth metal oxides. Therefore, in the present application, CaO + BaO + SrO = 2-4wt%.

[0081] The patent selects TiO2-ZrO2-P2O5 ternary system oxide as a crystal nucleus agent, which has a very important role in the microcrystallization heat treatment process of the glass-ceramics. If the content is insufficient, the crystallization degree of the β-quartz solid solution is not enough, the content of the negative expansion phase is insufficient, and the product's thermal expansion coefficient is too high, or the β-quartz solid solution grain growth is too large, thereby causing the optical decline of the glass-ceramics. If the content of the crystal nucleus agent is too high, the product body grows too fast, which leads to optical decline, and even more, the β-quartz solid solution is converted into the β-spodumene phase, which leads to the increase of thermal expansion. Similarly, if the composition design of the three is unreasonable, the above problems will also occur. In the present application, in order to expand the microcrystallization temperature and time interval of the ultra-low expansion glass-ceramics, the content of the nucleating agent is relatively low compared with other patents, which is: TiO2 1-2%, ZrO2 1-2%, and P2O5 4-5%.

[0082] In the present application, B2O3, Na2O and K2O are selected as the fluxing agent, which can effectively reduce the glass melting temperature. However, B2O3, Na2O and K2O are not contained in the present project because they are prone to ion migration during the Si and Mo plating process. In the present application, the ultra-low expansion control agent, rare earth oxide Ln2O3 (Ln = Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Er, Tm, Yb, Lu), is replaced by three or more kinds.

[0083] In an optional embodiment, the glass transition temperature of the ultra-low expansion transparent glass-ceramics material is 700-850℃, and the initial crystallization temperature is 800-1000℃.

[0084] In the present application, the main crystal phase of the ultra-low expansion transparent glass-ceramics material is a β-quartz solid solution phase with a particle size in the range of 1-10 nm and a crystal phase content of ≥80%.

[0085] In an optional embodiment, the average linear expansion coefficient of the ultra-low expansion transparent glass-ceramics is ±(0.5-10) ppb / K (0-50℃), and the thermal expansion uniformity of the medium cavity is also controlled to be ±(0.5-10) ppb / K (0-50℃). The ultra-low expansion transparent glass-ceramics material has an elastic modulus of 85-91 GPa, a Poisson's ratio of 0.245-0.255, a microcrystallization system of 690-720℃ for 9-15 hours, an ultra-low thermal expansion coefficient of ±(0.5-10) ppb / K (0-50℃), a surface error roughness controlled to ≤0.20 nm rms through ion beam polishing (IBF) and other processing technologies, and a transmittance of higher than 85% in the wavelength range of 500-1500 nm.

[0086] The following exemplary describes the preparation method of the ultra-low expansion transparent glass-ceramics material, and the preparation process is as follows:

[0087] In an optional embodiment, the base glass melting raw materials of the microcrystalline glass are selected as follows: SiO2 is introduced by one or more of silica with a purity of ≥99.9% or quartz glass;

[0088] Al2O3 is introduced by one or more of AlPO4 and Al(OH)3 with a purity of ≥99.9%, wherein AlPO4 can both play a fluxing role and improve the reactivity of AlPO4 and Al(OH)3 during the melting process, thereby reducing the melting temperature;

[0089] Li2O is introduced by one or more of carbonates or oxides with a purity of ≥99.9%;

[0090] R'O (R' = Sr, Ca) and R"2O (R" = Na, K) are introduced by one or more of carbonates / nitrates with a purity of ≥99.0%, wherein the carbonates / nitrates are controlled to be 1:(0-0.5);

[0091] BaO is introduced by one or more of barium nitrates with a purity of ≥99.0%, because barium carbonate decomposes too much at ≥1400°C, which is not conducive to gas removal, resulting in too high gas content in the glass matrix, leading to the precipitation of bubbles during fining, thereby affecting the quality of the matrix glass, while the decomposition temperature of barium nitrate is 600°C;

[0092] ZnO / MgO / TiO2 / ZrO2 are introduced by oxides with a purity of ≥99.9%;

[0093] P2O5 is introduced by AlPO4 with a purity of ≥99.9%;

[0094] The fining agent is introduced by at least one of Sb2O3, CeO2, and a combination thereof with a purity of ≥99.9%.

[0095] The above raw materials are calculated according to the composition of the oxides in mass percent, accurately weighed using an electronic balance, and mixed uniformly in a three-dimensional mixer with iron removal function;

[0096] The platinum-rhodium crucible or quartz crucible is used in a glass high-temperature melting furnace at 1550-1600°C for 2-6 hours for melting, and a pair of rollers is used for rapid cold extraction into glass fragments (which can be referred to as glass clinker hereinafter). The glass clinker melting process is operated 1-4 times, and the extrusion pressure during the forming process is used to improve the uniformity of the glass composition and eliminate the dissolved bubbles in the glass matrix.

[0097] After initial crushing, the glass frit is added to a self-designed multi-layer platinum-rhodium or quartz crucible at room temperature or 1400-1500°C, and heated to 1550-1600°C at a rate of 1-5°C / min for 2-8h of melting-homogenization of the ingredients, and then decreased to 1500-1400°C at a rate of 1-5°C / min for 4-10h of fining, and then decreased to 600-700°C at a rate of 2-10°C / min for 24-96h of annealing treatment, and then decreased to 150°C at a rate of 0.5-2°C / min and then air-cooled to room temperature after the electric current is turned off, without stirring process during the glass melting-homogenization process. Specifically, the charging temperature and melting system are 1450-1500°C for 4-24h (furnace 1), the micro-channel homogenization system is 1550-1600°C for 4-24h (furnace 2), the fining system is 1400-1500°C for 4-12h (furnace 3), and the annealing system is 600-700°C for 12-48h (furnace 4). In an optional embodiment, the micro-channel homogenization process is completed by using a self-designed multi-layer crucible with a micro-channel structure, and the upper and middle layer crucibles in the micro-channel homogenization process can be platinum-rhodium crucibles or quartz crucibles, and the bottom layer crucible can be a quartz crucible or a graphite crucible or a platinum-rhodium crucible. The glass frit melting process uses a platinum-rhodium crucible or a quartz crucible, and a high-temperature glass melting furnace is used. The glass stirring process in the preparation method of the glass-ceramic uses an eccentric stirring process, and the stirring process is divided into a high-speed process of 30-60r / min and a low-speed process of 15-25r / min, and the ratio of high-speed stirring time to low-speed stirring time is 1:(0.2-0.5).

[0098] The homogeneous, defect-free glass blank is placed in a self-designed rotary crystallization furnace and heated to 680-750°C at a rate of 0.5-2°C / min for microcrystallization treatment. Preferably, the microcrystallization system in the preparation method of the glass-ceramic is 680-750°C for 6-24h, and is respectively annealed at 350 and 500°C for 24h, and the heating and cooling rates are 0.1-3°C / min. In the microcrystallization process of the preparation method of the glass-ceramic, a rotary crystallization furnace is used, the temperature control accuracy is ±1°C, and the rotation speed is 0.1-1r / min.

[0099] Test method:

[0100] (1) Thermal expansion analysis test: The thermal expansion test uses a German Linseis laser dilatometer DIL L75 Laser thermal expansion analyzer, and the sample size is 50mm x 6mm, and the sample is heated from -50°C to 100°C at a rate of 1°C / min.

[0101] (2) Differential thermal analysis (DSC): Differential thermal analysis was performed on sample powder passed through a 200-mesh sieve using a Netzsch DSC 404 differential scanning calorimeter (Germany) from room temperature to 1100℃, with a temperature rise rate of 10℃ / min;

[0102] (3) X-ray diffraction analysis (XRD): After sintering, the sample was crushed with an agate mortar and passed through a 200-mesh sieve, and was tested using a Bruker D8 ADVANCE high-resolution powder X-ray diffractometer with a test voltage of 40KV, a test current of 40mA, Cu / Kα rays, a scanning range of 10-80°, and a scanning speed of 5° / min. The obtained XRD pattern was searched for JCPDS cards using Jade software to determine the crystal phase type;

[0103] (4) Transmission electron microscope analysis (TEM): After sintering, the sample was crushed with an agate mortar and passed through a 200-mesh sieve, and was observed for morphology using a Tecnai G2 F20 field emission transmission electron microscope;

[0104] (5) Optical performance test: The test of the Young's modulus of the microcrystalline glass in the present application is based on the standard "GB / T 7962.12-2010 Colorless Optical Glass Test Methods Part 12: In-Spectrum Transmittance"

[0105] (6) Mechanical property test: The test of the Young's modulus of the microcrystalline glass in the present application is based on the standard "GBT 7962 6-2010 Colorless Optical Glass Test Methods Part 6: Young's Modulus, Shear Modulus and Poisson's Ratio"; the test standard of Knoop hardness is "GB / T 7962.18-2010 Colorless Optical Glass Test Methods Part 18: Knoop Hardness"; and the test standard of bending strength is "GBT 6569-2006 Fine Ceramic Bending Strength Test Method".

[0106] The following further examples are further illustrated in detail. It should also be understood that the following examples are only used to further illustrate the present application, and cannot be understood as limiting the scope of protection of the present application. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present application all belong to the protection scope of the present application. The specific process parameters in the following examples are only one example in the appropriate range, i.e., those skilled in the art can make appropriate selection within the range through the description herein, and are not limited to the specific values in the following examples.

[0107] Example 1:

[0108] (1)Batching: according to the glass mass fraction of Example 1 in Table 1, the total mass is 2000 grams, and each corresponding raw material is calculated and weighed: SiO2 961.50 grams, Al(OH)3 530.11 grams, Li2CO3 153.21 grams, CaCO3 57.98 grams, AlPO4 86.9 grams, ZnO 40.36 grams, ZrO2 22.77 grams, TiO2 22.77 grams, Sb2O3 10.05 grams, MgO 16.74 grams, Ba(NO3)3 49.38 grams, Sm2O3 10.57 grams, Tb2O3 11.17 grams, Er2O3 11.75 grams, and the mixture is obtained after rotating for 8 hours with a three-dimensional mixer with iron removal function and discharging.

[0109] (2) Clinker melting system: the mixture in step (1) is placed in a 1550°C platinum crucible and melted for 43 hours, and the glass melt is poured into a roller gate machine;

[0110] (3) Clinker melting system: the mixture in step (2) is placed in a 1550°C furnace and kept for 2 hours, and the glass melt is introduced into a 1620°C furnace through a microflow pipe and kept for 6 hours (first stirring at 40 rpm for 4 hours, then stirring at 20 rpm / min for 2 hours, a total of 6 hours), and the uniform glass liquid is introduced into a 1460°C furnace and kept for 4 hours, then poured into a forming mold;

[0111] (4) Annealing process: the glass in step (3) is placed in a 670°C rotary annealing furnace and kept for 24 hours, then cooled to 100°C at a rate of 2°C / min, and the power is turned off and the furnace is cooled to room temperature;

[0112] (5) Crystallization process: the glass obtained in step (4) is placed in a rotary crystallization furnace and heated to 350°C at a rate of 1°C / min and kept for 24h, then heated to 500°C at a rate of 1°C / min and kept for 24h, and finally heated to 690°C at a rate of 1°C / min and kept for 12h, then cooled to 100°C at a rate of 2°C / min, the power is turned off and the furnace is cooled to room temperature, and an ultra-low expansion glass-ceramic material is obtained.

[0113] Example 2:

[0114] The preparation process of the glass-ceramic material in this example 2 is referred to example 1, the only difference is that: (1) ingredients: according to the glass ratio in table 1 of example 1, with the total mass of 2000 grams, calculate and take each corresponding raw material: SiO2 961.50 grams, Al(OH)3 530.11 grams, Li2CO3 153.21 grams, CaCO3 57.98 grams, AlPO4 86.9 grams, ZnO 40.36 grams, ZrO2 22.77 grams, TiO2 22.77 grams, Sb2O3 10.05 grams, MgO 16.74 grams, Ba(NO3)3 49.38 grams, Nd2O3 10.14 grams, Tb2O3 11.18 grams, Yb2O3 12.17 grams, after rotating for 8 hours by using the three-dimensional mixer with iron removal function, the mixture is obtained.

[0115] Example 3:

[0116] The preparation process of the glass-ceramic material in this example 3 is referred to example 1, the only difference is that: (1) ingredients: according to the glass ratio in table 1 of example 3, with the total mass of 2000 grams, calculate and take each corresponding raw material: SiO2 961.50 grams, Al(OH)3 530.12 grams, Li2CO3 153.21 grams, CaCO3 57.98 grams, AlPO4 86.9 grams, ZnO 40.36 grams, ZrO2 22.77 grams, TiO2 22.77 grams, Sb2O3 10.05 grams, MgO 16.75 grams, Ba(NO3)3 49.38 grams, Nd2O3 6.09 grams, Sm2O3 6.34 grams, Tb2O3 6.7 grams, Er2O3 7.06 grams, Yb2O3 7.3 grams, after rotating for 8 hours by using the three-dimensional mixer with iron removal function, the mixture is obtained.

[0117] Example 4:

[0118] The preparation process of the glass-ceramic material in this embodiment 4 is referred to the embodiment 1, the difference is only that: (1) the batching: according to the glass batching of the embodiment 1 in table 1, the total mass is 2000 grams, each corresponding raw material is calculated and weighed: SiO2 961.50 grams, Al(OH)3 530.12 grams, Li2CO3 153.21 grams, CaCO3 57.98 grams, AlPO4 86.9 grams, ZnO 40.36 grams, ZrO2 22.77 grams, TiO2 22.77 grams, Sb2O3 10.05 grams, MgO 16.75 grams, Ba(NO3)3 49.38 grams, Y2O3 2.51 grams, La2O3 3.93 grams, Nd2O3 4.08 grams, Sm2O3 4.25 grams, Tb2O3 4.49 grams, Dy2O3 4.6 grams, Er2O3 4.73 grams, Yb2O3 4.89 grams, the mixture is obtained after the rotation of the three-dimensional mixer with iron removal function for 8 hours.

[0119] Embodiment 5:

[0120] The preparation process of the glass-ceramic material in this embodiment 5 is referred to the embodiment 1, the difference is only that: (1) the batching: according to the glass batching of the embodiment 1 in table 1, the total mass is 2000 grams, each corresponding raw material is calculated and weighed: SiO2 955.54 grams, Al(OH)3 526.83 grams, Li2CO3 152.26 grams, CaCO3 72.47 grams, AlPO4 86.36 grams, ZnO 40.11 grams, ZrO2 22.63 grams, TiO2 22.63 grams, Sb2O3 9.98 grams, MgO 16.64 grams, Ba(NO3)3 63.25 grams, Y2O3 1.25 grams, La2O3 1.95 grams, Nd2O3 2.03 grams, Sm2O3 2.11 grams, Tb2O3 2.23 grams, Dy2O3 2.28 grams, Er2O3 2.35 grams, Yb2O3 2.43 grams, the mixture is obtained after the rotation of the three-dimensional mixer with iron removal function for 8 hours.

[0121] Embodiment 6:

[0122] The preparation process of the glass-ceramic material in this example 6 refers to example 1, the difference is only in that: (1) batching: according to the glass ratio in example 1 in table 1, calculate and weigh each corresponding raw material with total mass of 2000 grams: SiO2 961.50 grams, Al(OH)3 530.12 grams, Li2CO3 153.21 grams, CaCO3 57.98 grams, AlPO4 86.9 grams, ZnO 40.36 grams, ZrO2 22.77 grams, TiO2 22.77 grams, Sb2O3 10.05 grams, MgO 16.75 grams, Ba(NO3)3 49.38 grams, Sc2O3 3.75 grams, La2O3 3.77 grams, Nd2O3 3.92 grams, Sm2O3 4.08 grams, Tb2O3 4.32 grams, Dy2O3 4.41 grams, Er2O3 4.54 grams, Yb2O3 4.7 grams, and the mixture is obtained after rotating for 8 hours with a three-dimensional mixer having iron removal function and discharging.

[0123] Example 7:

[0124] The preparation process of the glass-ceramic material in this example 7 refers to example 1, the difference is only in that: (5) crystallization process: the glass obtained in step (4) is placed in a rotating crystallization furnace and heated to 350℃ at a heating rate of 1℃ / min for 24h, then heated to 500℃ at a heating rate of 1℃ / min for 24h, and finally heated to 680℃ at a heating rate of 1℃ / min for 12h, and then cooled to 100℃ at a cooling rate of 2℃ / min, and the furnace is cooled to room temperature after power-off, to obtain a super-low expansion glass-ceramic material.

[0125] Example 8:

[0126] The preparation process of the glass-ceramic material in this example 8 refers to example 1, the difference is only in that: (5) crystallization process: the glass obtained in step (4) is placed in a rotating crystallization furnace and heated to 350℃ at a heating rate of 1℃ / min for 24h, then heated to 500℃ at a heating rate of 1℃ / min for 24h, and finally heated to 740℃ at a heating rate of 1℃ / min for 12h, and then cooled to 100℃ at a cooling rate of 2℃ / min, and the furnace is cooled to room temperature after power-off, to obtain a super-low expansion glass-ceramic material.

[0127] Comparative Example 1:

[0128] The preparation process of the glass-ceramic material in the present comparative example 1 is referred to example 1, the difference is only that: (1) batching: according to the glass ratio of example 1 in table 1, the total mass is 2000 grams, each corresponding raw material is calculated and weighed: SiO2 957.02 grams, Al(OH)3 513.72 grams, Li2CO3 152.496 grams, CaCO3 57.71 grams, Na2CO3 22.8 grams, K2CO3 29.34 grams, AlPO4 108.26 grams, ZnO 40.17 grams, ZrO2 29 grams, TiO2 29 grams, Sb2O3 0 grams, MgO 11.33 grams, Ba(NO3)3 49.15 grams, Y2O3 0 grams, La2O3 0 grams, Nd2O3 0 grams, Sm2O3 0 grams, Tb2O3 0 grams, Dy2O3 0 grams, Er2O3 0 grams, Yb2O3 0 grams, and the mixture is obtained after the rotation of the three-dimensional mixer with iron removal function for 8 hours.

[0129] Comparative example 2:

[0130] The preparation process of the glass-ceramic material in the present comparative example 2 is referred to example 1, the difference is only that: (1) batching: according to the glass ratio of example 1 in table 1, the total mass is 2000 grams, each corresponding raw material is calculated and weighed: SiO2 955.59 grams, Al(OH)3 512.95 grams, Li2CO3 152.26 grams, CaCO3 72.47 grams, Na2CO3 11.38 grams, K2CO3 14.65 grams, AlPO4 108.09 grams, ZnO 40.11 grams, ZrO2 28.96 grams, TiO2 28.96 grams, Sb2O3 0 grams, MgO 11.32 grams, Ba(NO3)3 63.26 grams, Y2O3 0 grams, La2O3 0 grams, Nd2O3 0 grams, Sm2O3 0 grams, Tb2O3 0 grams, Dy2O3 0 grams, Er2O3 0 grams, Yb2O3 0 grams, and the mixture is obtained after the rotation of the three-dimensional mixer with iron removal function for 8 hours.

[0131] Comparative example 3:

[0132] The preparation process of the glass-ceramic material in Comparative Example 3 is the same as that in Example 1, except that (1) the ingredients are calculated and weighed according to the glass composition in Example 1 in Table 1, with a total mass of 2000 grams: SiO2 958.14 grams, Al(OH)3 514.32 grams, Li2CO3 152.67 grams, CaCO3 57.78 grams, SrCO3 23.77 grams, Na2CO3 11.41 grams, K2CO3 14.69 grams, AlPO4 108.38 grams, ZnO 40.21 grams, ZrO2 29.03 grams, TiO2 29.03 grams, Sb2O3 0 grams, MgO 161.35 grams, Ba(NO3)3 49.20 grams, Y2O3 0 grams, La2O3 0 grams, Nd2O3 0 grams, Sm2O3 0 grams, Tb2O3 0 grams, Dy2O3 0 grams, Er2O3 0 grams, Yb2O3 0 grams, and the mixture is obtained after rotating for 8 hours using a three-dimensional mixer with iron removal function.

[0133] Comparative Example 4:

[0134] The preparation process of the glass-ceramic material in Comparative Example 4 is the same as that in Example 1, except that (1) the ingredients are calculated and weighed according to the glass composition in Example 1 in Table 1, with a total mass of 2000 grams: SiO2 984.61 grams, Al(OH)3 528.53 grams, Li2CO3 156.89 grams, CaCO3 13.47 grams, AlPO4 111.38 grams, ZnO 41.33 grams, ZrO2 29.84 grams, TiO2 29.84 grams, Sb2O3 10.29 grams, MgO 11.66 grams, Ba(NO3)3 6.72 grams, Y2O3 0 grams, La2O3 0 grams, Nd2O3 0 grams, Sm2O3 23.12 grams, Tb2O3 0 grams, Dy2O3 0 grams, Er2O3 25.72 grams, Yb2O3 26.61 grams, and the mixture is obtained after rotating for 8 hours using a three-dimensional mixer with iron removal function.

[0135] Comparative Example 5:

[0136] The preparation process of the glass-ceramic material in Comparative Example 5 refers to Example 1, the only difference is that: (1) batching: according to the glass ratio in Example 1 in Table 1, calculate and weigh each corresponding raw material with a total mass of 2000 grams: SiO2 961.50 grams, Al(OH)3 530.12 grams, Li2CO3 153.21 grams, CaCO3 57.98 grams, AlPO4 86.9 grams, ZnO 40.36 grams, ZrO2 22.77 grams, TiO2 22.77 grams, Sb2O3 10.05 grams, MgO 16.75 grams, Ba(NO3)3 49.38 grams, Y2O3 0 grams, La2O3 22.49 grams, Nd2O3 0 grams, Sm2O3 0 grams, Tb2O3 0 grams, Dy2O3 0 grams, Er2O3 0 grams, Yb2O3 0 grams, and the mixture is obtained after rotating for 8 hours with a three-dimensional mixer having a deironing function and discharging.

[0137] Comparative Example 6:

[0138] (3) The mixture in step (2) is placed in a 1550℃ furnace for 2 hours, the glass melt is introduced into a 1620℃ furnace through a micro-flow pipe for 6 hours (stirring at a speed of 40 rpm for 6 hours), and the uniform glass liquid is introduced into a 1460℃ furnace body for 4 hours and then poured into a forming mold.

[0139] Comparative Example 7:

[0140] (3) The mixture in step (2) is placed in a 1550℃ furnace for 2 hours, the glass melt is introduced into a 1620℃ furnace through a micro-flow pipe for 6 hours (stirring at a speed of 20 rpm / min for 6 hours), and the uniform glass liquid is introduced into a 1460℃ furnace body for 4 hours and then poured into a forming mold.

[0141] Comparative Example 8:

[0142] The preparation process of the glass-ceramic material in Comparative Example 9 refers to Example 1, the only difference is that: (5) crystallization process: the glass obtained in step (4) is placed in a rotating crystallization furnace, heated to 350℃ at a heating rate of 1℃ / min for 24h, then heated to 500℃ at a heating rate of 1℃ / min for 24h, and finally heated to 670℃ at a heating rate of 1℃ / min for 12h, and then cooled to 100℃ at a cooling rate of 2℃ / min, and then the power is turned off and the furnace is cooled to room temperature, to obtain an ultra-low expansion glass-ceramic material.

[0143] Comparative Example 9:

[0144] The preparation process of the glass-ceramic material in Comparative Example 9 is the same as that in Example 1, except that (5) the crystallization process: the glass obtained in step (4) is placed in a rotating crystallization furnace and heated to 350℃ at a heating rate of 1℃ / min for 24h, then heated to 500℃ at a heating rate of 1℃ / min for 24h, and finally heated to 760℃ at a heating rate of 1℃ / min for 12h, and then cooled to 100℃ at a cooling rate of 2℃ / min, and then the furnace is turned off and cooled to room temperature, to obtain a super-low expansion glass-ceramic material.

[0145] Table 1 is a comparison of the composition and properties of the glass-ceramic materials obtained in Examples 1-5 (mass percentage)

[0146]

[0147]

[0148] Table 2 is a comparison of the composition and properties of the glass-ceramic materials obtained in Comparative Examples 7-8 / Comparative Examples 6-9 (mass percentage)

[0149]

[0150]

[0151] Table 2 is a comparison of the composition and properties of the glass-ceramic materials obtained in Comparative Examples 1-5 (mass percentage)

[0152]

[0153]

[0154] In the present application, by controlling the β-quartz solid phase ultrafine crystal microcrystallization (crystal size of 1-10nm) in the Li2O-Al2O3-SiO2 system glass through high-entropy rare earth oxides, an extremely low expansion coefficient of 0.5-10ppb / ℃ is obtained, and the crystallization temperature and crystallization time interval of the microcrystalline glass with extremely low expansion coefficient can be effectively widened, which is beneficial to obtain high-uniformity extremely low-expansion transparent microcrystalline glass. And the surface error roughness can be controlled to ≤0.2nm rms through small grinding head polishing (CCP), magnetorheological polishing (MRF) and ion beam polishing (IBF) and other processing technologies, which can be used as the basic material of the optical reflection element in the extreme ultraviolet lithography machine (EUVL), and also can be used as the basic material of the workpiece table and mask table in the lithography machine.

Claims

1. A method for preparing an ultra-low expansion transparent glass-ceramic material, characterized in that: The glass material comprises: 53-60 wt% SiO2, 20-26 wt% Al2O3, 3-4 wt% Li2O, 1-4 wt% ZnO, 0.5-3 wt% MgO, 0.2-3 wt% RO, 1-2 wt% TiO2, 1-2 wt% ZrO2, 3-3.02 wt% P2O5, 0.5-3 wt% Ln2O3, and 0-2 wt% fining agent; wherein R = at least one of Sr, Ca, and Ba; Ln = at least one of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Tb, Er, Tm, Yb, and Lu; and the fining agent is at least one selected from Sb2O3, CeO2, and a combination thereof; The preparation method comprises: (1) Si source, Al source, Li source, Zn source, Mg source, Ti source, Zr source, P source, R source, Ln source and clarifier are mixed, and then melted, homogenized and quenched to obtain glass slag; (2) melting, homogenizing, clarifying and annealing the obtained glass slag to obtain the glass material; (3) The glass material is subjected to microcrystallization treatment to obtain an extremely low expansion transparent microcrystalline glass material, wherein the microcrystallization treatment system includes: a temperature of 680 to 740°C, a heat preservation time of 6 to 24 hours, and a heating rate and a cooling rate of the microcrystallization treatment are both 0.01 to 3°C / min.

2. The preparation method according to claim 1, wherein The glass material comprises 55-60 wt% SiO2, 20-25 wt% Al2O3, 3-4 wt% Li2O, 2-4 wt% ZnO, 1-3 wt% MgO, 1-3 wt% RO, 1-2 wt% TiO2, 1-2 wt% ZrO2, 3-3.02 wt% P2O5, 0.5-3 wt% Ln2O3 and 0.5-2 wt% clarifier.

3. The preparation method according to claim 1, wherein Among them, SiO2+Al2O3+Li2O+MgO+ZnO=85~90wt%; Li2O+MgO+ZnO=6~8wt%, Li2O / (MgO+ZnO) =1.1~1.5; Wherein Ln = at least three of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Er, Tm, Yb, and Lu; The glass material does not contain PbO, Bi2O3, Na2O, K2O and As2O3.

4. The preparation method according to claim 1, characterized in that The microcrystallization process is accompanied by rotation, and the rotation speed is 0.05 to 1 revolutions per minute.

5. The preparation method according to claim 1, characterized in that The microcrystallization treatment system includes: first keeping the temperature at 300-400°C for 6-24 hours, then keeping the temperature at 500-550°C for 6-24 hours, then keeping the temperature at 680-740°C for 6-24 hours, and finally cooling to 200-300°C, then turning off the power and cooling the temperature to room temperature along with the furnace.

6. The preparation method according to claim 1, characterized in that The Si source is silicon oxide and / or quartz glass, and the purity of the Si source is ≥99.9%; The Al source is at least one of AlPO4 and Al(OH)3, and the purity of the Al source is ≥99.9%; The Li source is Li2O and / or lithium carbonate, and the purity of the Li source is ≥99.9%; The Zn source is ZnO with a purity of ≥99.9%; The Mg source is MgO with a purity of ≥99.9%; The Ti source is TiO2 with a purity of ≥99.9%; The Zr source is ZrO2 with a purity of ≥99.9%; The P source is P2O5 or / and AlPO4, and the purity of the P source is ≥99.9%; The R source is at least one of an oxide of R, a carbonate of R, and a nitrate of R, and the purity of the R source is ≥99.9%; The Ln source is at least one of Ln oxide, Ln carbonate, and Ln nitrate, and the purity of the Ln source is ≥99.9%.

7. The preparation method according to claim 1, characterized in that In step (1): the melting-homogenizing temperature is 1550-1600° C., and the holding time is 2-6 hours; The quenching system is to pour the molten glass into a roller mill for quenching treatment.

8. The preparation method according to claim 7, characterized in that The heating rate and cooling rate of the melting are both 2-20°C / min.

9. The preparation method according to claim 1, characterized in that The melting-homogenizing and quenching operations are performed 1 to 4 times.

10. The preparation method according to claim 9, characterized in that The melting-homogenizing and quenching operations are performed 1 to 3 times.

11. The preparation method according to claim 1, characterized in that In step (2): The melting temperature is 1575-1640°C and the holding time is 6-24 hours; The homogenization temperature is 1575-1640°C and stirring is performed simultaneously during the homogenization process. The stirring system includes: first high-speed stirring at 30-60 rpm, and then low-speed stirring at 15-25 rpm; the total homogenization and stirring time is 6-24 hours, and the ratio of high-speed stirring time to low-speed stirring time is 1:(0.2-0.5); The clarification temperature is 1400-1500°C and the holding time is 4-12 hours; The annealing temperature is 600-700° C., and the heat preservation time is 12-48 hours.

12. The preparation method according to claim 11, characterized in that In step (2), the melting, homogenization, clarification and annealing are respectively carried out in four crucibles, and the heating rate and cooling rate are both 2 to 20°C / min; The crucible used for melting is a platinum-rhodium crucible or a quartz crucible; The crucible used for homogenization is a platinum-rhodium crucible or a quartz crucible; The crucible used for clarification is a quartz crucible or a graphite crucible; The crucible used for annealing is a quartz crucible or a graphite crucible, and the components used can be free of processing or require minimal processing through structural design.

13. An ultra-low expansion transparent glass-ceramic material prepared by the preparation method according to any one of claims 1 to 12, characterized in that: The crystallization phase in the ultra-low expansion transparent microcrystalline glass material contains a β-quartz solid solution phase.

14. The ultra-low expansion transparent glass-ceramic material according to claim 13, characterized in that: The composition of the ultra-low expansion transparent glass-ceramic material does not contain PbO, Bi2O3, Na2O, K2O and As2O3.

15. The ultra-low expansion transparent glass-ceramic material according to claim 13 or 14, characterized in that: The crystal particle size of the crystallized phase is 5 to 10 nm, and the content of the crystallized phase is 70 to 80 vol%.

16. The ultra-low expansion transparent glass-ceramic material according to claim 13 or 14, characterized in that: The ultra-low expansion transparent glass-ceramic material has an average thermal expansion coefficient of 0.5-10 ppb / °C, an elastic modulus of 85-91 GPa, and a Poisson's ratio of 0.245-0.

255.

17. Use of the ultra-low expansion transparent glass-ceramic material according to any one of claims 13 to 16 in an optical reflective element of an EUVL lithography machine.

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