TW202235390A - Glass - Google Patents

Abstract

Provided is a glass is characterized by containing, as the glass composition thereof, 55-80 mol% SiO2, 11-30 mol% Al2O3, 0-3 mol% B2O3, 0-3 mol% Li2O + Na2O + K2O, and 5-35 mol% MgO + CaO + SrO + BaO, and by the strain point being higher than 700 DEG C.

Description

Glass

The present invention relates to a glass with high heat resistance, for example, relates to a glass substrate for making semiconductor crystals for Light Emitting Diodes (LEDs) at high temperatures.

For semiconductor crystals used in LEDs and the like, it is known that the higher the temperature at which the film is formed, the more the semiconductor characteristics will be improved.

Generally, a highly heat-resistant sapphire (sapphire) substrate is used for such applications. In other applications, a sapphire substrate is also used when forming a semiconductor crystal film at a high temperature (for example, 700° C. or higher). [Prior art literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 11-243229

[Problem to be Solved by the Invention] In addition, in recent years, a technique of forming a large-area semiconductor crystal into a film has been actively studied. It is believed that this technology is also expected to be used as a surface-emitting light source for large displays.

However, a sapphire substrate is difficult to achieve a large area, and is not suitable for such applications.

If a glass substrate is used instead of a sapphire substrate, it is considered that the substrate can be enlarged in area, but conventional glass substrates are not sufficiently heat resistant, and thus tend to be thermally deformed during high-temperature heat treatment.

Moreover, if the heat resistance of the conventional glass substrate is to be improved, the thermal expansion coefficient of the glass substrate will be unduly lowered, making it difficult to match the thermal expansion coefficient of the semiconductor crystal. After the semiconductor crystal is produced, the glass substrate is easy to warp, or the semiconductor The film is prone to cracks. Furthermore, when trying to improve the heat resistance of a glass substrate, devitrification resistance will fall, and it will become difficult to shape it into a flat glass substrate.

The present invention was made in view of the above circumstances, and its technical problem is to create glass that has high heat resistance and thermal expansion coefficient and can be formed into a flat plate shape.

MEANS TO SOLVE THE PROBLEM As a result of repeated various experiments, the present inventors found that the said technical subject can be solved by limiting a glass composition to a predetermined range, and came up with this invention. That is, the glass of the present invention is characterized by containing 55% to 80% of SiO ₂ , 11% to 30% of Al ₂ O ₃ , 0 to 3% of B ₂ O ₃ , and 0 to 3% in mole %. % Li ₂ O+Na ₂ O+K ₂ O, 5%-35% MgO+CaO+SrO+BaO as the glass composition, and the strain point (strain point) is higher than 700°C. Here, "Li ₂ O+Na ₂ O+K ₂ O" means the total amount of Li ₂ O, Na ₂ O and K ₂ O. "MgO+CaO+SrO+BaO" means the total amount of MgO, CaO, SrO, and BaO. Here, the "strain point" refers to a value measured based on the method of American Society for Testing and Materials (ASTM) C336.

In the glass composition of the present invention, the content of Al ₂ O ₃ is limited to 11 mol % or more, the content of B ₂ O ₃ is limited to 3 mol % or less, and Li ₂ O+Na ₂ O+K ₂ The content of O is limited to 3 mol % or less. Thereby, the strain point rises remarkably, and the heat resistance of a glass substrate can be improved significantly.

Furthermore, the glass of the present invention contains 5 mol% to 25 mol% of MgO+CaO+SrO+BaO in the glass composition. Thereby, thermal expansion coefficient can be raised, and devitrification resistance can be improved.

Second, the B ₂ O ₃ content of the glass of the present invention is preferably less than 1 mol%.

Thirdly, the content of Li ₂ O+Na ₂ O+K ₂ O in the glass of the present invention is preferably 0.2 mol % or less.

Fourth, the molar ratio (MgO+CaO+SrO+BaO)/Al ₂ O ₃ of the glass of the present invention is preferably 0.5-5. Here, "(MgO+CaO+SrO+BaO)/Al ₂ O ₃ " is a value obtained by dividing the total amount of MgO, CaO, SrO, and BaO by the content of Al ₂ O ₃ .

Fifth, the glass of the present invention preferably has a molar ratio MgO/(MgO+CaO+SrO+BaO) of less than 0.5. Here, "MgO/(MgO+CaO+SrO+BaO)" is a value obtained by dividing the content of MgO by the total amount of MgO, CaO, SrO, and BaO.

Sixth, the thermal expansion coefficient of the glass of the present invention in the temperature range of 30°C to 380°C is preferably 40×10 ^-7 /°C or higher. Here, "the thermal expansion coefficient in the temperature range of 30 degreeC - 380 degreeC" means the average value measured by the dilatometer.

Seventh, the strain point of the glass of the present invention is preferably 800° C. or higher.

Eighth, the glass of the present invention (temperature-strain point at a high temperature viscosity of 10 ^2.5 dPa·s) is preferably 900°C or lower. Here, "the temperature at which the high-temperature viscosity is 10 ^2.5 dPa·s" refers to a value measured by the platinum ball pulling method.

Ninth, the temperature of the glass of the present invention is preferably below 1750°C when the high temperature viscosity is 10 ^2.5 dPa·s.

Tenth, the glass of the present invention is preferably in the shape of a flat plate.

Eleventh, the glass of the present invention is preferably used as a substrate for growing semiconductor crystals.

The glass of the present invention contains 55% to 80% of SiO ₂ , 11% to 30% of Al ₂ O ₃ , 0 to 3% of B ₂ O ₃ , and 0 to 3% of Li ₂ O+ in mole %. Na ₂ O+K ₂ O, 5% to 35% MgO+CaO+SrO+BaO are used as the glass composition. As mentioned above, the reason for limiting content of each component is demonstrated below. In addition, in description of each component, the following expression of % means mole %.

The appropriate lower limit range of _SiO2 is more than 55%, more than 58%, more than 60%, more than 65%, especially more than 68%, and the appropriate upper limit range is preferably less than 80%, less than 75%, less than 73%, and less than 72%. % or less, 71% or less, especially 70% or less. When the content of SiO ₂ is too small, defects due to devitrified crystals containing Al ₂ O ₃ are likely to occur, and the strain point is likely to decrease. Furthermore, the high-temperature viscosity decreases, and the liquid phase viscosity tends to decrease. On the other hand, if the content of _SiO2 is too high, the coefficient of thermal expansion will decrease unduly, and the high-temperature viscosity will increase, the meltability will decrease, and devitrification crystals containing _SiO2 will easily occur.

The appropriate lower limit of Al ₂ O ₃ is 11%, 12%, 13%, 14%, especially 15%, and the appropriate upper limit is 30%, 25%, 20%, 18% % or less, 17% or less, especially 16% or less. When the content of Al ₂ O ₃ is too small, the strain point tends to decrease, or the high-temperature viscosity increases, and the meltability tends to decrease. On the other hand, when the content of Al ₂ O ₃ is too large, devitrified crystals containing Al ₂ O ₃ are likely to be generated.

From the viewpoint of both high strain point and high devitrification resistance, the molar ratio SiO ₂ /Al ₂ O ₃ is preferably 2-6, 3-5.5, 3.5-5.5, 4-5.5, 4.5-5.5, especially 4.5-5. _In addition, " _SiO2 / _Al2O3 " is the value obtained by dividing the content _{of SiO2} by the content of _Al2O3 .

The appropriate upper limit range of B ₂ O ₃ is 3% or less, 1% or less, less than 1%, especially 0.1% or less. When the content of B ₂ O ₃ is too high, the strain point may be significantly lowered.

The appropriate upper limit range of Li ₂ O+Na ₂ O+K ₂ O is 3% or less, 1% or less, less than 1%, 0.5% or less, especially 0.2% or less. When the content of Li ₂ O+Na ₂ O+K ₂ O is too large, the properties of the semiconductor crystal formed on the glass may deteriorate. In addition, the appropriate upper limit ranges of Li ₂ O, Na ₂ O, and K ₂ O are respectively 3% or less, 1% or less, less than 1%, 0.5% or less, 0.3% or less, especially 0.2% or less.

The appropriate lower limit range of MgO+CaO+SrO+BaO is 5% or more, 7% or more, 9% or more, 11% or more, 13% or more, especially 14% or more, and the appropriate upper limit range is 35% or less, 30% Less than 25%, less than 20%, less than 18%, less than 17%, especially less than 16%. If the content of MgO+CaO+SrO+BaO is too small, the liquidus temperature will rise significantly, devitrification crystals will easily occur in the glass, or the high-temperature viscosity will increase, and the meltability will easily decrease. On the other hand, if the content of MgO+CaO+SrO+BaO is too large, the strain point will tend to fall, and devitrified crystals containing alkaline earth elements will tend to occur.

The appropriate lower limit range of MgO is 0% or more, 1% or more, 2% or more, 3% or more, 4% or more, especially 5% or more, and the appropriate upper limit range is 15% or less, 10% or less, 8% or less, Especially less than 7%. When there is too little content of MgO, meltability will fall easily, or the devitrification property of the crystal|crystallization containing an alkaline-earth element will become high easily. On the other hand, if the content of MgO is too high, the precipitation of devitrified crystals including Al ₂ O ₃ will be promoted, resulting in a decrease in liquid phase viscosity, or a significant decrease in strain point. In addition, although MgO has the effect of increasing the thermal expansion coefficient, the effect of MgO is the smallest among alkaline earth oxides.

The appropriate lower limit range of CaO is 2% or more, 3% or more, 4% or more, 5% or more, 6% or more, especially 7% or more, and the appropriate upper limit range is 20% or less, 15% or less, 12% or less, Below 11%, below 10%, especially below 9%. When there is too little content of CaO, meltability will fall easily. On the other hand, when there is too much content of CaO, a liquidus temperature will rise, and devitrification crystal|crystallization will generate|occur|produce easily in glass. Furthermore, compared with other alkaline earth oxides, CaO has a greater effect of improving the liquid phase viscosity or improving the meltability without lowering the strain point, and has a greater effect of increasing the thermal expansion coefficient than MgO.

The appropriate lower limit range of SrO is 0% or more, 1% or more, especially 2% or more, and the appropriate upper limit range is 10% or less, 8% or less, 7% or less, 6% or less, 5% or less, especially 4% the following. When there is too little content of SrO, a strain point will fall easily. On the other hand, if the content of SrO is too large, the liquidus temperature will rise, devitrification crystals will easily occur in the glass, and the meltability will tend to decrease. Furthermore, when it coexists with CaO, when content of SrO increases, there exists a tendency for devitrification resistance to fall. Furthermore, SrO has a greater effect of raising the thermal expansion coefficient than MgO or CaO.

The appropriate lower limit range of BaO is 0% or more, 3% or more, 4% or more, 5% or more, 6% or more, 7% or more, especially 8% or more, and the appropriate upper limit range is 15% or less, 12% or less, Below 11%, especially below 10%. When the content of BaO is too small, the strain point and the coefficient of thermal expansion tend to decrease. On the other hand, when there is too much content of BaO, a liquidus temperature will rise, and devitrification crystal|crystallization will generate|occur|produce easily in glass. Furthermore, meltability tends to decrease. Furthermore, BaO has the greatest effect of increasing the thermal expansion coefficient or strain point among alkaline earth metal oxides.

From the viewpoint of improving devitrification resistance, the lower limit range of the molar ratio MgO/CaO is preferably 0.1 or more, 0.2 or more, 0.3 or more, especially 0.4 or more, and the upper limit range is preferably 2 or less, 1 or less, and 0.8 or less. , 0.7 or less, especially 0.6 or less. In addition, "MgO/CaO" means the value which divided the content of MgO by the content of CaO.

From the viewpoint of improving devitrification resistance, the lower limit range of the molar ratio BaO/CaO is preferably 0.2 or more, 0.5 or more, 0.6 or more, 0.7 or more, especially 0.8 or more, and the upper limit range is preferably 5 or less and 4.5 or less , 3 or less, 2.5 or less, especially 2 or less. In addition, "BaO/CaO" means the value which divided the content of BaO by the content of CaO.

In view of the balance between strain point and melting property, the lower limit range of the molar ratio (MgO+CaO+SrO+BaO)/Al ₂ O ₃ is preferably 0.5 or more, 0.6 or more, 0.7 or more, especially 0.8 or more, and the upper limit range is better 5.0 or less, 4.0 or less, 3.0 or less, 2.0 or less, 1.5 or less, 1.2 or less, especially 1.1 or less.

The molar ratio MgO/(MgO+CaO+SrO+BaO) is preferably 0.6 or less, less than 0.5, 0.4 or less, 0.3 or less, 0.2 or less, especially 0.1 or less. MgO is a component that greatly lowers the strain point, and the effect of lowering the strain point is remarkable in an area where the content of MgO is small. Accordingly, it is preferable that the content ratio of MgO in the alkaline earth metal oxide is small.

7×[MgO]+5×[CaO]+4×[SrO]+4×[BaO] is preferably 100% or less, 90% or less, 80% or less, 70% or less, 65% or less, especially 60% the following. All alkaline earth metal elements have the effect of lowering the strain point, but the smaller the ionic radius of the element, the greater the effect. In this way, the upper limit of 7×[MgO]+5×[CaO]+4×[SrO]+4×[BaO] is limited so as not to increase the proportion of alkaline earth elements with small ionic radii , the strain point can be increased preferentially. In addition, [MgO] means the content of MgO, [CaO] means the content of CaO, [SrO] means the content of SrO, and [BaO] means the content of BaO. Moreover, "7×[MgO]+5×[CaO]+4×[SrO]+4×[BaO]" means 7 times [MgO], 5 times [CaO], 4 times [SrO] and 4 times the total amount of [BaO].

21×[MgO]+20×[CaO]+15×[SrO]+12×[BaO] is preferably 200% or more, 210% or more, 220% or more, 230% or more, 240% or more, 250% or more, In particular, it is 300% to 1000%. Alkaline earth metal elements all have the effect of improving the meltability, but the smaller the ionic radius of the element, the greater the effect. In this way, the lower limit of 21×[MgO]+20×[CaO]+15×[SrO]+12×[BaO] is limited so as not to increase the proportion of alkaline earth elements with small ionic radii , the meltability can be preferentially improved. However, if 21×[MgO]+20×[CaO]+15×[SrO]+12×[BaO] is too large, the strain point may decrease. Furthermore, "21×[MgO]+20×[CaO]+15×[SrO]+12×[BaO]" means 21 times [MgO], 20 times [CaO], and 15 times [SrO] And 12 times the total amount of [BaO].

In addition to the above components, the following components may also be introduced into the glass composition.

ZnO is a component that improves the meltability, but if the glass composition contains a large amount of ZnO, the glass is likely to be devitrified and the strain point is likely to be lowered. Accordingly, the content of ZnO is preferably 0-5%, 0-3%, 0-0.5%, 0-0.3%, especially 0-0.1%.

ZrO ₂ is a component that increases Young's modulus. The content of ZrO ₂ is preferably 0-5%, 0-3%, 0-0.5%, 0-0.2%, especially 0-0.02%. If the content of ZrO ₂ is too high, the liquidus temperature will rise, and devitrified crystals of zircon (zircon) will easily precipitate.

TiO ₂ is a component that lowers high-temperature viscosity to improve meltability, and is a component that suppresses solarization. However, when the glass composition contains a large amount of TiO ₂ , the glass tends to be colored. Accordingly, the content of TiO ₂ is preferably 0-5%, 0-3%, 0-1%, 0-0.1%, especially 0-0.02%.

P ₂ O ₅ is a component that improves the devitrification resistance, but if the glass composition contains a large amount of this P ₂ O ₅ , the glass is likely to phase-separate and become opalescent, and there is a possibility that the water resistance may be significantly lowered. Accordingly, the content of P ₂ O ₅ is preferably 0 to 5%, 0 to 4%, 0 to 3%, 0 to less than 2%, 0 to 1%, 0 to 0.5%, especially 0 to 0.1%.

SnO ₂ is a component that has a good clarification effect in a high-temperature region, and is a component that lowers high-temperature viscosity. The content of SnO ₂ is preferably 0-1%, 0.01%-0.5%, 0.01%-0.3%, especially 0.04%-0.1%. When the content of SnO ₂ is too large, devitrified crystals of SnO ₂ are easily precipitated.

As mentioned above, it is preferable to add SnO ₂ as a clarifying agent to the glass of the present invention, but CeO ₂ , SO ₃ , C, metal powder (such as Al, Si, etc.) as clarifiers.

As ₂ O ₃ , Sb ₂ O ₃ , F, and Cl also function effectively as clarifiers, and the glass of the present invention does not exclude the inclusion of these components, but from an environmental point of view, the contents of these components are relatively low. It is preferably less than 0.1%, especially less than 0.05%.

In the case of containing 0.01% to 0.5% of SnO ₂ , if the content of Rh ₂ O ₃ is too large, the glass will be easily colored. Furthermore, Rh ₂ O ₃ may be mixed in from the platinum manufacturing container. The content of Rh ₂ O ₃ is preferably from 0 to 0.0005%, more preferably from 0.00001% to 0.0001%.

SO ₃ is a component mixed from the raw material as an impurity, but if the content of SO ₃ is too high, bubbles called reboil will be generated during melting or forming, which may cause defects in the glass. The appropriate lower limit range of SO ₃ is 0.0001% or more, and the appropriate upper limit range is 0.005% or less, 0.003% or less, 0.002% or less, especially 0.001% or less.

The content of rare earth oxides (oxides of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, etc.) is preferably less than 2%, Less than 1%, less than 0.5%, especially less than 0.1%. In particular, the content of La ₂ O ₃ +Y ₂ O ₃ is preferably less than 2%, less than 1%, less than 0.5%, especially less than 0.1%. The content of La ₂ O ₃ is preferably less than 2%, less than 1%, less than 0.5%, especially less than 0.1%. If the content of the rare earth oxide is too high, the batch cost will easily increase. In addition, "Y ₂ O ₃ +La ₂ O ₃ " is the total amount of Y ₂ O ₃ and La ₂ O ₃ .

The glass of the present invention preferably has the following properties.

The density is preferably 3.20 g/cm ³ or less, 3.00 g/cm ³ or less, 2.90 g/cm ³ or less, especially 2.80 g/cm ³ or less. If the density is too high, it will be difficult to reduce the weight of electronic components.

The thermal expansion coefficient in the temperature range of 30°C to 380°C is preferably 40×10 ^-7 /°C or higher, 42×10 ^-7 /°C or higher, 44×10 ^-7 /°C or higher, 46×10 ^-7 /°C or higher , preferably 48×10 ^-7 /°C to 80×10 ^-7 /°C. If the thermal expansion coefficient in the temperature range of 30° C. to 380° C. is too low, the thermal expansion coefficients of semiconductor crystals (for example, nitride semiconductor crystals) and the glass substrate will not match, and the glass substrate will easily warp, or the semiconductor crystal will easily crack.

The strain point is preferably higher than 700°C, higher than 750°C, higher than 780°C, higher than 800°C, higher than 810°C, higher than 820°C, particularly preferably 830°C to 1000°C. If the strain point is too low, the heat treatment temperature cannot be increased, making it difficult to improve the semiconductor characteristics of the semiconductor crystal.

The SiO ₂ -Al ₂ O ₃ -RO (RO means alkaline earth metal oxide)-based glass of the present invention is generally difficult to melt. Therefore, improvement of meltability becomes a subject. If the meltability is improved, the defective rate due to air bubbles, foreign matter, etc. will be reduced, and thus a large amount of high-quality glass substrates can be supplied at low cost. On the other hand, if the high-temperature viscosity is too high, it is difficult to promote degassing by the melting step. Accordingly, the temperature at high temperature viscosity of 10 ^2.5 dPa·s is preferably below 1750°C, below 1700°C, below 1680°C, below 1670°C, below 1650°C, especially below 1630°C. Furthermore, the temperature at a high-temperature viscosity of 10 ^2.5 dPa·s corresponds to the melting temperature, and the lower the temperature, the better the meltability.

From the viewpoint of achieving both a high strain point and a low melting temperature, (temperature-strain point at 10 ^2.5 dPa·s) is preferably 900°C or lower, 850°C or lower, especially 800°C or lower.

When forming into a flat plate shape, devitrification resistance becomes important. Considering the forming temperature of the SiO ₂ -Al ₂ O ₃ -RO glass of the present invention, the liquidus temperature is preferably 1450°C or lower, 1400°C or lower, especially 1300°C or lower. Furthermore, the liquid phase viscosity is preferably at least 10 ^3.0 dPa·s, at least 10 ^3.5 dPa·s, especially at least 10 ^4.0 dPa·s. Furthermore, "liquidus temperature" refers to putting glass powder that passed through a 30 mesh (500 μm) standard sieve and remained on a 50 mesh (300 μm) standard sieve into a platinum boat , the value obtained by measuring the temperature at the time of crystallization in a temperature gradient furnace for 24 hours. The "liquidus viscosity" refers to a value obtained by measuring the viscosity of glass at the liquidus temperature by the platinum ball pulling method.

The glass of the present invention can be formed by various forming methods. For example, the glass substrate can be shaped by an overflow down draw method, a slot down draw method, a redraw method, a float method, a roll out method, or the like. Furthermore, if the glass substrate is shaped by the overflow down-draw method, it is easy to produce a glass substrate with high surface smoothness.

When the glass of the present invention is in the form of a plate, the plate thickness is preferably not more than 1.0 mm, not more than 0.7 mm, not more than 0.5 mm, especially not more than 0.4 mm. The smaller the plate thickness, the easier it is to reduce the weight of electronic components. On the other hand, the smaller the plate thickness, the easier the glass substrate is to bend, but the glass of the present invention has a higher Young's modulus or higher specific Young's modulus, so it is less likely to cause defects caused by bending . Furthermore, the plate thickness can be adjusted by utilizing the flow rate during forming, the plate pulling speed, and the like.

In the glass of the present invention, if the β-OH value is lowered, the strain point can be increased. The β-OH value is preferably 0.45/mm or less, 0.40/mm or less, 0.35/mm or less, 0.30/mm or less, 0.25/mm or less, 0.20/mm or less, especially 0.15/mm or less. When the β-OH value is too large, the strain point tends to decrease. Furthermore, when the β-OH value is too small, the meltability tends to decrease. Accordingly, the β-OH value is preferably at least 0.01/mm, especially at least 0.05/mm.

The following method can be mentioned as a method of reducing a (beta)-OH value. (1) Choose raw materials with low water content. (2) Add components (Cl, SO ₃ , etc.) that reduce the moisture content in the glass. (3) Reduce the moisture content in the furnace environment. (4) _N2 bubbling in molten glass. (5) Use a small melting furnace. (6) Speed up the flow of molten glass. (7) The electric melting method is adopted.

Here, the "β-OH value" refers to a value obtained by measuring the transmittance of glass using a Fourier Transform Infrared Spectrometer (Fourier Transform Infrared Spectrometer, FT-IR) and using the following formula. β-OH value=(1/X)log(T ₁ /T ₂ ) X: Glass wall thickness (mm) T ₁ : Transmittance (%) at reference wavelength of 3846 cm ^-1 T ₂ : 3600 cm ^-1 Minimum transmittance (%) at nearby hydroxyl absorption wavelength [Example]

Hereinafter, the present invention will be described in detail based on examples. In addition, the following embodiment is only an illustration. The present invention is not limited to the following examples at all.

Tables 1 to 4 show Examples (sample No. 1 to No. 63) of the present invention.

[Table 1] No.1 No.2 No.3 No.4 No.5 No.6 No.7 No.8 No.9 No.10 No.11 No.12 No.13 No.14 No.15 No.16 Composition (mol%) SiO ₂ 59.9 59.9 64.9 64.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 63.9 63.9 63.9 Al ₂ O ₃ 25.0 25.0 20.0 20.0 15.0 15.0 15.0 15.0 15.0 13.0 13.0 13.0 13.0 18.0 18.0 18.0 B ₂ O ₃ 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Li ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Na ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 K ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 MgO 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 8.5 0.0 0.0 0.0 9.0 0.0 0.0 CaO 0.0 0.0 0.0 0.0 0.0 0.0 7.5 7.5 0.0 0.0 8.5 8.5 0.0 0.0 9.0 9.0 SrO 15.0 0.0 15.0 0.0 15.0 0.0 7.5 0.0 7.5 0.0 8.5 0.0 8.5 0.0 9.0 0.0 BaO 0.0 15.0 0.0 15.0 0.0 15.0 0.0 7.5 7.5 8.5 0.0 8.5 8.5 9.0 0.0 9.0 _SnO2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 _{Li2O +} Na2O ₊ K2O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 MgO+CaO+SrO+BaO 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 17.0 17.0 17.0 17.0 18.0 18.0 18.0 (MgO+CaO+SrO+BaO)/Al ₂ O ₃ 0.60 0.60 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.31 1.31 1.31 1.31 1.00 1.00 1.00 ρ[g/cm ³ ] 2.82 3.01 2.78 2.98 2.73 2.93 2.62 2.74 2.84 2.76 2.65 2.78 2.90 2.82 2.71 2.84 α[×10 ^-7 /℃] 40.9 43.5 41.7 45.3 44.6 49.0 41.0 43.0 46.4 40.3 44.5 46.9 49.6 40.1 45.1 46.8 Ps[°C] 822 Not determined 824 832 823 832 806 798 816 781 783 769 779 777 802 797 Ta[°C] 875 Not determined 880 894 882 896 863 816 879 825 826 819 824 814 856 855 Ts[°C] Not determined Not determined 1091 1120 1107 1137 1075 1091 1117 1060 1052 1051 1063 1042 1060 1065 10 ^4.0 dPa s[°C] Not determined Not determined 1365 1413 1416 1471 1393 1411 1444 1383 1367 1382 1404 1326 1328 1346 10 ^3.0 dPa s[°C] Not determined Not determined 1506 1554 1573 1630 1547 1570 1605 1545 1528 1549 1576 1467 1468 1489 10 ^2.5 dPa s[°C] Not determined Not determined 1595 1645 1674 1736 1648 1673 1708 1651 1633 1656 1686 1559 1559 1582 TL[°C] Not determined Not determined 1517 Not determined 1497 Not determined 1404 1388 1484 1293 1385 1328 1438 1376 1498 1352 logηTL[dPa s] Not determined Not determined 2.9 Not determined 3.4 Not determined 3.9 4.2 3.7 4.7 3.9 4.4 3.8 3.6 2.8 4.0 10 ^2.5 dPa s-Ps[°C] Not determined Not determined 771 813 851 904 842 874 892 870 850 887 907 782 757 785 β-OH[/mm] Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined

[Table 2] No.17 No.18 No.19 No.20 No.21 No.22 No.23 No.24 No.25 No.26 No.27 No.28 No.29 No.30 No.31 No.32 Composition (mol%) SiO ₂ 63.9 63.9 58.9 64.2 71.8 63.9 63.9 63.9 63.9 69.4 68.4 69.9 69.9 69.9 69.9 66.6 Al ₂ O ₃ 18.0 16.0 11.6 12.7 14.2 16.0 16.0 16.0 16.0 14.8 14.3 15.0 15.0 15.0 15.0 14.3 B ₂ O ₃ 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Li ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Na ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 K ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 MgO 0.0 10.0 29.4 0.0 0.0 10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 CaO 0.0 0.0 0.0 23.0 0.0 0.0 10.0 10.0 0.0 7.4 7.2 10.0 10.0 5.0 5.0 4.8 SrO 9.0 10.0 0.0 0.0 13.9 0.0 10.0 0.0 10.0 0.0 0.0 5.0 0.0 10.0 5.0 0.0 BaO 9.0 0.0 0.0 0.0 0.0 10.0 0.0 10.0 10.0 7.4 7.2 0.0 5.0 0.0 5.0 14.3 _SnO2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 1.0 2.9 0.1 0.1 0.1 0.1 0.1 _{Li2O +} Na2O ₊ K2O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 MgO+CaO+SrO+BaO 18.0 20.0 29.4 23.0 13.9 20.0 20.0 20.0 20.0 14.8 14.4 15.0 15.0 15.0 15.0 19.0 (MgO+CaO+SrO+BaO)/Al ₂ O ₃ 1.00 1.25 2.53 1.82 0.98 1.25 1.25 1.25 1.25 1.00 1.01 1.00 1.00 1.00 1.00 1.33 ρ[g/cm ³ ] 2.96 2.72 2.61 2.61 2.70 2.86 2.74 2.88 3.02 Not determined Not determined 2.59 2.66 2.66 2.73 2.99 α[×10 ^-7 /℃] 49.9 41.5 42.0 50.7 42.9 43.8 47.3 50.3 53.8 Not determined Not determined 40.9 42.1 42.4 43.8 53.2 Ps[°C] 817 761 742 754 822 766 779 768 777 Not determined Not determined 804 798 808 800 758 Ta[°C] 876 813 787 802 885.5 820 832 823 833 Not determined Not determined 861 856 867 862 816 Ts[°C] 1053 1020 960 988 1165 1033 1034 1036 1052 Not determined Not determined 1080 1082 1089 1094 1041 10 ^4.0 dPa s[°C] 1382 1294 1180 1243 1438 1314 1309 1325 1364 Not determined Not determined 1374 1392 1398 1410 1359 10 ^3.0 dPa s[°C] 1528 1433 1296 1382 1602 1456 1451 1472 1504 Not determined Not determined 1534 1547 1556 1568 1517 10 ^2.5 dPa s[°C] 1620 1524 1374 1475 1708 1547 1543 1565 1598 Not determined Not determined 1630 1649 1658 1669 1617 TL[°C] Not determined 1374 1308 1324 1463 1390 1474 Not determined Not determined Not determined Not determined 1399 1361 >1469 1391 >1510 logηTL[dPa s] Not determined 3.4 2.9 3.4 3.8 3.4 2.9 Not determined Not determined Not determined Not determined 3.8 4.3 <3.5 4.2 <3.0 10 ^2.5 dPa s-Ps[°C] 803 763 632 721 886 781 764 797 821 Not determined Not determined 826 851 850 869 859 β-OH[/mm] Not determined Not determined Not determined Not determined 0.1 Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined

[table 3] No.33 No.34 No.35 No.36 No.37 No.38 No.39 No.40 No.41 No.42 No.43 No.44 No.45 No.46 No.47 No.48 Composition (mol%) SiO ₂ 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 69.9 Al ₂ O ₃ 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 B ₂ O ₃ 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Li ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Na ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 K ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 MgO 0.0 0.0 5.0 0.0 2.5 2.5 0.0 1.0 1.0 1.0 2.5 2.5 2.5 2.5 5.0 2.5 CaO 0.0 0.0 0.0 5.0 5.0 5.0 10.0 6.0 6.0 6.0 0.0 0.0 0.0 0.0 0.0 2.5 SrO 10.0 5.0 0.0 0.0 2.5 0.0 2.5 8.0 4.0 0.0 12.5 7.5 5.0 0.0 2.5 5.0 BaO 5.0 10.0 10.0 10.0 5.0 7.5 2.5 0.0 4.0 8.0 0.0 5.0 7.5 12.5 7.5 5.0 _SnO2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 _{Li2O +} Na2O ₊ K2O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 MgO+CaO+SrO+BaO 18.0 20.0 29.4 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 (MgO+CaO+SrO+BaO)/Al ₂ O ₃ 1.20 1.33 1.96 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 ρ[g/cm ³ ] 2.80 2.87 2.80 2.79 2.69 2.72 2.62 2.63 2.68 2.74 2.69 2.75 2.79 2.84 2.76 2.73 α[×10 ^-7 /℃] 45.9 47.4 40.7 44.6 40.5 41.0 41.2 41.0 41.6 42.5 41.3 42.3 43.0 44.3 40.1 41.3 Ps[°C] 818 818 788 798 779 780 797 795 790 788 793 790 788 795 783 786 Ta[°C] 880 882 850 860 839 840 856 854 850 849 853 852 851 860 844 846 Ts[°C] 1112 1121 1087 1100 1076 1080 1080 1080 1082 1088 1085 1092 1098 1118 1081 1084 10 ^4.0 dPa s[°C] 1430 1453 1411 1432 1392 1403 1387 1390 1400 1410 1400 1417 1426 1441 1401 1404 10 ^3.0 dPa s[°C] 1591 1617 1571 1594 1552 1565 1545 1548 1560 1572 1559 1580 1590 1602 1562 1563 10 ^2.5 dPa s[°C] 1698 1730 1674 1694 1654 1667 1646 1649 1661 1675 1660 1683 1692 1704 1664 1664 TL[°C] >1510 >1512 1371 1398 1300 1290 1378 1400 1359 1344 1433 1405 1398 1434 1345 1386 logηTL[dPa s] <3.5 <3.6 4.3 4.3 4.8 5.0 4.1 3.9 4.3 4.5 3.8 4.1 4.2 4.0 4.5 4.1 10 ^2.5 dPa s-Ps[°C] 880 912 886 896 875 887 849 854 871 887 867 893 904 909 881 878 β-OH[/mm] Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined

[Table 4] No.49 No.50 No.51 No.52 No.53 No.54 No.55 No.56 No.57 No.58 No.59 No.60 No.61 No.62 No.63 Composition (mol%) SiO ₂ 69.9 69.9 69.9 69.9 69.9 69.9 68.9 69.9 68.9 69.9 68.9 70.9 69.9 71.9 70.9 Al ₂ O ₃ 15.0 15.0 15.0 15.0 15.0 15.0 15.0 14.0 15.0 14.0 15.0 13.0 13.0 13.0 13.0 B ₂ O ₃ 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Li ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Na ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 K ₂ O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 MgO 2.5 2.5 2.5 3.5 3.5 3.5 2.5 5.3 5.3 3.7 3.7 5.3 5.7 3.5 3.7 CaO 2.5 2.5 0.0 4.0 3.0 3.5 5.0 2.7 2.7 5.3 5.3 2.7 2.8 5.0 5.3 SrO 2.5 0.0 2.5 0.0 0.0 1.5 0.0 2.7 2.7 0.0 0.0 2.7 2.8 0.0 0.0 BaO 7.5 10.0 10.0 7.5 8.5 6.5 7.5 5.3 5.3 6.9 6.9 5.3 5.7 6.5 6.9 _SnO2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.0 0.0 0.1 0.1 0.1 0.1 _{Li2O +} Na2O ₊ K2O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 MgO+CaO+SrO+BaO 15.0 15.0 15.0 15.0 15.0 15.0 15.0 16.0 16.0 16.0 16.0 16.0 17.0 15.0 16.0 (MgO+CaO+SrO+BaO)/Al ₂ O ₃ 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.14 1.07 1.14 1.07 1.23 1.31 1.15 1.23 ρ[g/cm ³ ] 2.77 2.80 2.83 2.73 2.76 2.72 2.73 2.71 2.72 2.72 2.73 2.69 2.71 2.68 2.70 α[×10 ^-7 /℃] 42.0 42.7 43.8 40.3 41.0 40.3 41.2 40.2 40.2 41.5 41.4 40.6 42.0 40.2 41.7 Ps[°C] 788 789 797 780 782 780 767 769 773 770 776 765 761 772 767 Ta[°C] 849 852 860 841 844 840 827 828 832 831 835 826 820 833 827 Ts[°C] 1088 1094 1104 1078 1084 1077 1065 1062 1062 1065 1064 1066 1055 1077 1067 10 ^4.0 dPa s[°C] 1414 1420 1438 1395 1404 1396 1381 1381 1369 1386 1375 1390 1376 1406 1392 10 ^3.0 dPa s[°C] 1576 1580 1602 1555 1566 1556 1539 1539 1525 1545 1532 1552 1536 1571 1555 10 ^2.5 dPa s[°C] 1678 1680 1706 1654 1671 1655 1640 1639 1623 1648 1632 1657 1640 1677 1660 TL[°C] 1384 1404 >1455 1319 1345 1306 1298 1292 1311 1306 1318 Not determined Not determined Not determined Not determined logηTL[dPa s] 4.2 4.1 <3.88 4.6 4.5 4.8 4.7 4.8 4.5 4.7 4.5 Not determined Not determined Not determined Not determined 10 ^2.5 dPa s-Ps[°C] 890 891 909 874 889 875 873 870 850 878 856 891 879 905 893 β-OH[/mm] Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined Not determined

Each sample was prepared as follows. First, glass batches prepared by preparing glass raw materials so as to have the glass compositions in the table were put into platinum crucibles and melted at 1600° C. to 1750° C. for 24 hours. When melting the glass batch, stirring was performed using a platinum stirrer to homogenize the glass batch. Next, the molten glass is flowed onto a carbon plate to form a flat plate shape. For each sample obtained, density ρ, coefficient of thermal expansion α, strain point Ps, annealing point Ta, softening point Ts, temperature at high temperature viscosity of 10 ^4.0 dPa·s, temperature at high temperature viscosity of 10 ^3.0 dPa·s Temperature, temperature at high temperature viscosity of 10 ^2.5 dPa·s, liquidus temperature TL, liquidus viscosity logηTL.

Density ρ is a value measured by the well-known Archimedes method.

The thermal expansion coefficient α is an average value measured with a dilatometer in a temperature range of 30°C to 380°C.

The strain point Ps, the annealing point Ta, and the softening point Ts are values measured in accordance with ASTM C336 or ASTM C338.

The temperature at high temperature viscosity of 10 ^4.0 dPa·s, the temperature at high temperature viscosity of 10 ^3.0 dPa·s, and the temperature at high temperature viscosity of 10 ^2.5 dPa·s are values measured by the platinum ball pulling method.

The liquidus temperature TL is to pulverize each sample, put the glass powder that passes through a 30 mesh (500 μm) standard sieve and remains on a 50 mesh (300 μm) standard sieve into a platinum boat, and keep it in a temperature gradient furnace The temperature at which the platinum boat is taken out after 24 hours and devitrification (devitrification crystals) is seen in the glass. The liquidus viscosity logηTL is a value obtained by measuring the viscosity of glass at the liquidus temperature TL by the platinum ball pulling method.

The β-OH value is a value calculated from the above formula.

Tables 1 to 4 show that samples No. 1 to No. 63 have high strain points and thermal expansion coefficients, and have devitrification resistance capable of being formed into a flat plate shape. Accordingly, it is considered that samples No. 1 to No. 63 are suitable as substrates for crystal growth of semiconductor crystals (for example, nitride semiconductor crystals, especially gallium nitride-based semiconductor crystals) at high temperatures. [Industrial availability]

The glass of the present invention has a high strain point and a high coefficient of thermal expansion, and has good resistance to devitrification. Thereby, the glass of the present invention is not only suitable for substrates used to make semiconductor crystals at high temperatures, but also suitable for display substrates such as organic light emitting diode (Organic Light Emitting Diode, OLED) displays, liquid crystal displays, etc., especially suitable as A substrate for displays driven by low temperature polysilicon (Low Temperature Poly Silicon, LTPS) and oxide thin film transistors (Thin Film Transistor, TFT).

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Claims (11)

A glass, characterized in that: in mole %, it contains 55%-80% of SiO ₂ , 11%-30% of Al ₂ O ₃ , 0-3% of B ₂ O ₃ , and 0-3% of Li ₂ O+Na ₂ O+K ₂ O, 5%-35% MgO+CaO+SrO+BaO are used as the glass composition, and the strain point is higher than 700°C. The glass as described in Claim 1 of the scope of the patent application, wherein the content of B ₂ O ₃ is less than 1 mol%. The glass according to claim 1 or claim 2, wherein the content of Li ₂ O+Na ₂ O+K ₂ O is 0.2 mol% or less. The glass according to claim 1 or claim 2, wherein the molar ratio (MgO+CaO+SrO+BaO)/Al ₂ O ₃ is 0.5-5. The glass as described in claim 1 or claim 2, wherein The molar ratio MgO/(MgO+CaO+SrO+BaO) is less than 0.5. The glass according to Claim 1 or Claim 2, wherein the thermal expansion coefficient in the temperature range of 30°C to 380°C is 40×10 ^-7 /°C or higher. The glass as described in claim 1 or claim 2, wherein The strain point is above 800°C. The glass according to Claim 1 or Claim 2, wherein (temperature-strain point at high temperature viscosity of 10 ^2.5 dPa·s) is 900°C or lower. The glass according to Claim 1 or Claim 2, wherein the temperature at a high-temperature viscosity of 10 ^2.5 dPa·s is below 1750°C. The glass as described in claim 1 or claim 2, wherein The glass is in the shape of a flat plate. The glass as described in claim 1 or claim 2, wherein The glass is used as a substrate for making semiconductor crystals.