Glass member and method for manufacturing the same

Abstract

The present invention relates to a glass member used in a semiconductor manufacturing device, the glass member having a hydrogen content of 200 mass ppm or less. The present invention also relates to a method for manufacturing the glass member, the method for melting a glass raw material by heating the same at a melting temperature of 1500 to 1800°C, and cooling the obtained molten glass to a cooling stop temperature of 700 to 900°C at a cooling rate of 100 to 1500°C / min.

Description

Technical Field

[0001] The present invention relates to a glass member and a method for manufacturing the same.

Background Art

[0002] Members used in semiconductor manufacturing equipment are often exposed to plasma and gradually consumed during the operation of the semiconductor manufacturing equipment. A member with advanced wear is replaced with a new one. In recent years, with the increasing sophistication and complexity of products manufactured by semiconductor manufacturing equipment, the plasma environment to which the members are exposed has become increasingly severe, and in that case, the need to replace the members frequently arises. However, during the replacement of the members, the semiconductor manufacturing equipment cannot be operated. Therefore, as the replacement frequency of the members increases, the production efficiency of the products decreases.

[0003] Therefore, members used in semiconductor manufacturing equipment are required to have an even longer lifespan. That is, good plasma resistance is required.

[0004] Examples of semiconductor manufacturing equipment include, for example, plasma etching equipment. Various members such as a top plate (conductor type), a microwave introduction tube, lift pins, and various nozzles are used in plasma etching equipment. Conventionally, materials such as cordierite sintered compacts have been used as these members (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] A glass member may be used in a semiconductor manufacturing apparatus. In this case, the glass member is also required to have good plasma resistance.

[0007] The present invention has been made in view of the above points, and an object thereof is to provide a glass member used in a semiconductor manufacturing apparatus, which has excellent plasma resistance.

Means for Solving the Problems

[0008] As a result of intensive studies, the present inventors have found that the above object can be achieved by adopting the following configuration, and have completed the present invention.

[0009] That is, the present invention provides the following [1] to

[15] . [1] A glass member used in a semiconductor manufacturing apparatus, wherein the hydrogen content is 200 mass ppm or less. [2] The glass member according to [1] above, wherein the refractive index at a wavelength of 365 nm has an average of 1.5 or more, and the difference between the upper limit value and the lower limit value is 0.2 or less. [3] The glass member according to [1] or [2] above, which has a cross-sectional area of 10 cm 2 or more. [4] A ring shape with an outer diameter of 300 to 600 mm, an inner diameter of 200 to 450 mm, and a thickness of 2 to 30 mm, which is chamfered with C1.0 or less, has a surface roughness Ra of 1 μm or less, and a flatness of 0.5 mm or less. The glass member according to any one of [1] to [3] above. [5] The glass member according to any one of [1] to [4] above, which contains yttrium and silicon, and the molar ratio Y / Si of the yttrium content to the silicon content is 0.2 to 1.5. [6] The glass member according to any one of [1] to [5] above, wherein the SiO2 content is 40 to 70 mol%, the Y2O3 content is 5 to 40 mol%, and the Al2O3 content is 10 to 30 mol%. [7] The content of at least one element a selected from the group consisting of tantalum, boron, magnesium, calcium, strontium, and barium in terms of oxide is 10 mol% or less, and the glass member according to [6] above. [8] The content of at least one element b selected from the group consisting of alkali metal elements, iron, and titanium in terms of oxide is 3000 mass ppm or less, and the glass member according to [6] or [7] above. [9] The Young's modulus is 100 GPa or more, and the average coefficient of thermal expansion at 50 to 350 °C is 4 to 7 ppm / K, and the glass member according to any one of [1] to [8] above.

[10] The transmittance at a wavelength of 800 nm is 92% or less, and the glass member according to any one of [1] to [9] above.

[11] Any 100 mm 2 In 10 areas of the area region, the number of bubbles of 0.1 mm 2 or more is 40 or less in total, and the glass member according to any one of [1] to

[10] above.

[12] Any 100 mm 2 In 10 areas of the area region, 0.1 mm 2 or more, the average area ratio of crystals is 5% or less, and the glass member according to any one of [1] to

[11] above.

[13] Used as a focus ring, shower plate, electrostatic chuck, susceptor, injector, viewing window, top plate, or side wall provided in the semiconductor manufacturing apparatus, and the glass member according to any one of [1] to

[12] above.

[14] When etched with CF4 gas at a flow rate of 100 sccm, the etching rate is 0.1 or less with respect to quartz, and the glass member according to any one of [1] to

[13] above.

[15] A method for manufacturing the glass member according to any one of [1] to

[14] above, wherein the glass raw material is melted by heating at a melting temperature of 1500 to 1800 °C, and the obtained molten glass is cooled at a cooling rate of 100 to 1500 °C / min to a cooling stop temperature of 700 to 900 °C.

Advantages of the Invention

[0010] According to the present invention, a glass member excellent in plasma resistance can be provided.

Mode for Carrying Out the Invention

[0011] A numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0012] [Glass Member] The glass member of the present embodiment is a glass member used in a semiconductor manufacturing apparatus, and the hydrogen content thereof is 200 mass ppm or less.

[0013] Hereinafter, the glass member may be simply referred to as "glass", and the glass member of the present embodiment may also be referred to as "this glass member" or "this glass".

[0014] This glass member is excellent in plasma resistance. The reason is presumed as follows. First, hydrogen contained in the glass member is understood to be derived from water molecules. Since the amount of hydrogen is small, the structure of the glass member becomes dense, and as a result, the rate of deterioration due to plasma irradiation becomes slow. In addition, when the plasma (or the gas used for generating the plasma) contains fluorine, hydrogen contained in the glass member easily reacts with this fluorine. However, since the amount of this hydrogen is small, the reaction with fluorine relatively decreases, and damage to the glass member is suppressed.

[0015] 〈Hydrogen Content (H Content)〉 In this glass member, the hydrogen content (also denoted as "H content") is 200 mass ppm or less as described above. For the reason that the plasma resistance is more excellent, the H content is preferably 150 mass ppm or less, more preferably 100 mass ppm or less, still more preferably 50 mass ppm or less, yet more preferably 40 mass ppm or less, particularly preferably 30 mass ppm or less, very preferably 20 mass ppm or less, and most preferably 10 mass ppm or less.

[0016] On the one hand, since the H content is a realistic value that is easy to control in consideration of mass productivity, for example, it is 1 mass ppm or more, preferably 2 mass ppm or more, and more preferably 3 mass ppm or more.

[0017] The H content of the glass member is determined by secondary ion mass spectrometry (SIMS). More specifically, using a secondary ion mass spectrometer (model IMS-6f, manufactured by Ametek), the primary ion species Cs + is determined under the conditions of a primary acceleration voltage of 15.0 kV, a detection area of φ30 μm, and a measurement depth of 1 μm.

[0018] 〈Refractive index〉 《Average》 In this glass member, the average of the refractive index at a wavelength of 365 nm (also simply referred to as "refractive index") is preferably 1.5 or more, more preferably 1.57 or more, still more preferably 1.63 or more, particularly preferably 1.68 or more, and most preferably 1.7 or more. Thereby, this glass member has more excellent plasma resistance. The reason is presumably that elements such as yttrium (Y) have good plasma resistance, and when there are many such elements, the refractive index of the glass member becomes high.

[0019] On the other hand, the average of the refractive index is preferably 1.8 or less, more preferably 1.76 or less, and still more preferably 1.73 or less. When the average of the refractive index is within this range, crystallization during the production of the glass member is suppressed, and the surface reflectance of the glass member is suppressed, so light such as that of a sensor easily passes through.

[0020] 《Difference (variation) between the upper limit value and the lower limit value》 In this glass member, the difference (also referred to as "variation") between the upper limit value and the lower limit value of the refractive index is preferably 0.2 or less, more preferably 0.05 or less, still more preferably 0.01 or less, even more preferably 0.005 or less, particularly preferably 0.001 or less, very preferably 0.0005 or less, and most preferably 0.0003 or less. As a result, this glass member has better plasma resistance. The reason is presumably that when the refractive index is uniformly high without bias, phenomena such as only a part being easily damaged by plasma irradiation are less likely to occur, and the overall plasma resistance becomes good. In addition, when the glass member is enlarged, since the strength, composition, etc. may vary depending on the part, it is beneficial that the plasma resistance is good overall without bias in this way.

[0021] 《Measurement method》 The refractive index of the glass member is measured at any 10 points using a Carl Zeiss precision refractometer KPR-3000 (accuracy: ±0.00002 (23°C)). The average of the 10 measurement values is obtained as the average refractive index. Also, the difference between the upper limit value and the lower limit value of the 10 measurement values is obtained as the variation in refractive index (difference between the upper limit value and the lower limit value).

[0022] 〈Glass composition〉 Next, the composition of this glass member (glass composition) will be described. That is, the content of elements that the glass member can contain, etc. will be described.

[0023] 《Si, Y, and Al》 This glass member may contain silicon (Si) and yttrium (Y), and may further contain aluminum (Al).

[0024] (Molar ratio Y / Si) The molar ratio (Y / Si) of the content of yttrium (Y) to the content of silicon (Si) is preferably 0.2 or more, more preferably 0.4 or more, and still more preferably 0.5 or more. As a result, the relative amount of Y contained in the glass member increases, and the plasma resistance becomes more excellent. On the other hand, for the reason that crystallization during the production of the glass member is suppressed, the molar ratio (Y / Si) is preferably 1.5 or less, more preferably 1.0 or less, and still more preferably 0.8 or less.

[0025] (Content of SiO2) The content of SiO₂ is preferably 40 mol% or more, more preferably 45 mol% or more, and still more preferably 50 mol% or more. On the other hand, the content of SiO₂ is, for example, 80 mol% or less, preferably 70 mol% or less, more preferably 65 mol% or less, and still more preferably 60 mol% or less.

[0026] (Content of Y₂O₃) The content of Y₂O₃ is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 15 mol% or more, and particularly preferably 20 mol% or more. Thereby, the refractive index of the glass member becomes higher and the plasma resistance is more excellent. On the other hand, the content of Y₂O₃ is preferably 40 mol% or less, more preferably 35 mol% or less, still more preferably 30 mol% or less, and particularly preferably 25 mol% or less because the crystallization during the production of the glass member is suppressed.

[0027] (Content of Al₂O₃) The content of Al₂O₃ is preferably 10 mol% or more, more preferably 15 mol% or more, and still more preferably 18 mol% or more from the viewpoint of improving the strength and heat resistance of the glass member. On the other hand, the content of Al₂O₃ is preferably 30 mol% or less, more preferably 28 mol% or less, and still more preferably 25 mol% or less from the viewpoint of obtaining more excellent plasma resistance.

[0028] 《Element a: Ta, B, Mg, Ca, Sr, and Ba》 This glass member may contain at least one element a selected from the group consisting of tantalum (Ta), boron (B), magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba). However, the content of element a in terms of oxide is preferably 10 mol% or less, more preferably 8 mol% or less, still more preferably 5 mol% or less, even more preferably 3 mol% or less, particularly preferably 1 mol% or less, and most preferably 0 mol%. When this glass member contains a plurality of elements as element a, the "content of element a in terms of oxide" means the sum of the contents of the respective oxides of the plurality of elements.

[0029] The content of Ta in terms of oxide specifically means the content of Ta2O5. The content of B in terms of oxide specifically means the content of B2O3. The content of Mg in terms of oxide specifically means the content of MgO. The content of Ca in terms of oxide specifically means the content of CaO. The content of Sr in terms of oxide specifically means the content of SrO. The content of Ba in terms of oxide specifically means the content of BaO.

[0030] 《Element b: Alkali metal element, Fe, and Ti》 This glass member may contain at least one element b selected from the group consisting of an alkali metal element, iron (Fe), and titanium (Ti). Examples of the alkali metal element include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Among these, substantially, lithium (Li), sodium (Na), and potassium (K) are preferred. However, element b is an impurity element for the glass member used in the semiconductor manufacturing apparatus, and it is preferably less. Specifically, the content of element b in terms of oxide is preferably 3000 mass ppm or less, more preferably 1000 mass ppm or less, still more preferably 300 mass ppm or less, particularly preferably 100 mass ppm or less, and most preferably 50 mass ppm or less. In the case where this glass member contains a plurality of elements as element b, the "content of element b in terms of oxide" means the sum of the contents of each of the plurality of elements in terms of oxide.

[0031] The content of the alkali metal element (R) in terms of oxide specifically means the content of R2O. The content of Fe in terms of oxide specifically means the content of Fe2O3. The content of Ti in terms of oxide specifically means the content of TiO2.

[0032] 《Measurement Method》 The content (in terms of mol percentage or mass percentage based on oxide) of each of the above-described elements (excluding Si) in the glass member is measured using a fluorescent X-ray apparatus (XRF) (ZSX100e manufactured by Rigaku Corporation). That is, the X-ray intensity of each element on the surface of the glass member is measured and quantitatively analyzed to obtain the content of each element.

[0033] The content of SiO2 in the glass member is determined as follows. First, a powdered sample is collected by polishing from the central part of the glass member, and the total oxygen amount Z1 in the glass member is determined by the infrared absorption method using an oxygen / hydrogen analyzer (ROH-600 manufactured by LECO Corporation). The oxygen amount Z3 is calculated by subtracting the oxygen amount Z2 that is combined with the elements (excluding Si) in the glass member in a stoichiometric composition from the total oxygen amount Z1 in the glass member (oxygen amount Z3 = total oxygen amount Z1 - oxygen amount Z2). Assuming that the total amount of the oxygen amount Z3 is used for bonding with silicon atoms, the oxygen amount Z3 is converted into the SiO2 amount. The SiO2 amount thus obtained is taken as the content of SiO2 in the glass member.

[0034] 〈Young's modulus〉 The Young's modulus of this glass member is preferably 60 GPa or more, more preferably 80 GPa or more, still more preferably 100 GPa or more, and particularly preferably 110 GPa or more. Such a glass member has good dimensional accuracy, little deflection, and excellent thermal shock resistance. On the other hand, the upper limit of the Young's modulus of this glass member is not particularly limited, and is, for example, 200 GPa, preferably 180 GPa, and more preferably 160 GPa. The Young's modulus of the glass member is measured at 25 °C by the ultrasonic pulse method.

[0035] 〈Coefficient of thermal expansion〉 In a semiconductor manufacturing apparatus, the glass member may be used in combination with other members (also referred to as "peripheral members"), and examples of the materials of the peripheral members include SiC and AlN. The coefficient of thermal expansion of this glass member is preferably close to that of the material of the peripheral member. Thereby, the expansion and contraction behavior of this glass member becomes the same as that of the peripheral member, and detachment from the peripheral member and the like are prevented. Specifically, the average coefficient of thermal expansion of this glass member at 50 to 350 °C (simply also referred to as "coefficient of thermal expansion") is preferably 4 ppm / K or more, more preferably 4.1 ppm / K or more, still more preferably 4.2 ppm / K or more, and particularly preferably 4.5 ppm / K or more. On the other hand, the coefficient of thermal expansion of this glass member is preferably 7 ppm / K or less, more preferably 6.5 ppm / K or less, and still more preferably 6 ppm / K or less. The coefficient of thermal expansion is measured using a differential thermal dilatometer in accordance with the method described in JIS R 3102-1995.

[0036] 〈Transmittance〉 The lower the transmittance of the glass member, the better its heat insulation property. Therefore, from the viewpoint of obtaining good heat insulation property, the transmittance of this glass member at a wavelength of 800 nm (simply referred to as "transmittance") is preferably 92% or less, more preferably 91% or less, still more preferably 90% or less, even more preferably 89% or less, and particularly preferably 88% or less. However, depending on the use in semiconductor manufacturing equipment, a certain degree of transparency may be required for the glass member. Therefore, from the viewpoint of ensuring good transparency, the transmittance of this glass member is preferably 80% or more, more preferably 83% or more, and still more preferably 85% or more. The transmittance is measured for a glass member with a thickness of 2 mm by a method conforming to JIS R 3106 (1998). That is, such transmittance is the transmittance in terms of a thickness of 2 mm.

[0037] 〈Number of bubbles〉 The glass member may contain bubbles (air bubbles), but large bubbles are preferably few because of excellent appearance and more excellent plasma resistance. Specifically, in any 10 locations of a 100 mm 2 area region of the glass member, the number of bubbles of 0.1 mm 2 or more (simply referred to as "number of bubbles") is preferably 40 or less in total, more preferably 30 or less, still more preferably 20 or less, particularly preferably 10 or less, and most preferably 5 or less. More specifically, a plate-shaped (thickness: 2 mm) glass member is prepared, and for an arbitrary region (area: 100 mm 2 ) on the main surface of this glass member, a photograph is taken using an optical microscope, and from the photograph, the number of bubbles with an area of 0.1 mm 2 or more is measured. The total number of bubbles in 10 arbitrary regions is obtained.

[0038] 〈Crystal ratio〉 Although the glass member may contain crystals (crystalline phase), from the viewpoint of ensuring good transparency, it is preferable that large crystals are few. Also, from the viewpoint of reducing the dust generation that occurs when the glass member is exposed to plasma, it is preferable that large crystals are few. Specifically, in any 100 mm 2 area regions of the glass member, the area ratio of crystals of 0.1 mm 2 or more (also conveniently referred to as "crystal ratio") is preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less on average. More specifically, a glass member in the form of a plate (thickness: 2 mm) is prepared, and for an arbitrary region (area: 100 mm 2 ) on the main surface of this glass member, a photograph is taken using an optical microscope, and from the photograph, the area ratio (unit: %) of crystals with an area of 0.1 mm 2 or more is measured. The average of the area ratios of crystals in 10 arbitrary regions is obtained.

[0039] <Etching rate> In this glass member, when using CF4 gas with a flow rate of 100 sccm, the etching rate of this glass member with respect to quartz is preferably 0.1 or less, more preferably 0.05 or less, even more preferably 0.04 or less, still more preferably 0.03 or less, and most preferably 0.02 or less. The smaller the etching rate, the more excellent the plasma resistance of this glass member can be said to be. Since the life of this glass member is extended, the replacement frequency decreases, and the tact of the manufacturing apparatus is improved. The lower limit of the etching rate is not particularly limited, but from the viewpoint of ease of glass production, 0.01 or more is preferable. The calculation conditions for the etching rate in this specification are specifically as follows.

[0040] (Calculation conditions for the etching rate) A test piece with a size of 20 mm × 20 mm × 2 mm is cut out from the glass member, and the 20 mm × 20 mm surface is mirror-finished. A Kapton tape is attached to a part of the mirror-finished surface for masking, and etching is performed with a plasma gas under the following conditions. · Equipment: CCP-RIE · Gas type: CF4 (100 sccm) · Output: 350 W · Pressure: 10 Pa · Time: 130 minutes · Temperature: 20 °C After that, the etching amount (wear amount) is obtained by measuring the step differences generated in the etched portion and the non-etched portion using a stylus surface profiler (manufactured by ULVAC, Dectak 150). Furthermore, for quartz glass as well, the etching amount is obtained in the same manner. The ratio of the etching amount of the glass member to the etching amount of the quartz glass is obtained as the etching rate.

[0041] 〈Usage〉 This glass member is used, for example, as part or all of each part included in a semiconductor manufacturing apparatus (including a semiconductor inspection apparatus). Examples of the parts included in the semiconductor manufacturing apparatus include a focus ring, a shower plate, an electrostatic chuck, a susceptor, an injector (injector nozzle), a viewing window (a member for looking inside from the outside of the semiconductor manufacturing apparatus), a top plate, or a side wall (inner wall).

[0042] 〈Shape and size〉 Examples of the shape of this glass member include plate-like (e.g., disk-like, flat plate-like), spherical (true spherical, oblate spherical), ring-like, etc., and are appropriately selected according to the usage.

[0043] The size of this glass member is appropriately selected according to the usage. This glass member may be enlarged depending on the usage, and for example, may have a cross-sectional area of 10 cm 2 or more (for example, when the glass member is plate-like, the area of the cross-section parallel to the main surface). From the viewpoint of versatility, the cross-sectional area of this glass member is preferably 100 cm 2 or more, more preferably 300 cm 2 or more, and even more preferably 500 cm 2 or more. On the one hand, the upper limit of this cross-sectional area is not particularly limited. However, from the perspective of versatility, it is preferably 5000 cm 2 or less, and more preferably 1000 cm 2 or less.

[0044] When the glass member is used for a focus ring, a susceptor, etc., its shape is ring-shaped. For applications such as focus rings, etc., the outer diameter of the ring-shaped glass member is preferably 300 to 600 mm, and more preferably 350 to 450 mm. For the same reason, the inner diameter is preferably 200 to 450 mm, and more preferably 250 to 350 mm. For the same reason, the thickness is preferably 2 to 30 mm, and more preferably 3 to 7 mm. At this time, it is preferable that the ring-shaped glass member is chamfered to C1.0 or less. Also, from the perspective of suppressing dust generation when irradiated with plasma and being less affected by thermal stress, the surface roughness (arithmetic mean roughness Ra) of the ring-shaped glass member is preferably 1 μm or less, more preferably 0.1 μm or less, and even more preferably 0.03 μm or less. Ra is measured in accordance with JIS B 0601:2001. Also, due to good dimensional accuracy, the flatness of the ring-shaped glass member is preferably 0.5 mm or less, more preferably 0.1 mm or less, and even more preferably 0.03 mm or less. The flatness can be measured by a non-contact three-dimensional shape measuring device (manufactured by Mitaka Kogaku Co., Ltd., NH-5Ns).

[0045] [Manufacturing method of glass member] Next, a method for manufacturing this glass member (hereinafter also referred to as "this manufacturing method") will be described. In this manufacturing method, generally, glass raw materials are heated to be melted (dissolved), and the obtained molten glass is cooled.

[0046] 〈Glass raw materials〉 It is preferable to weigh and mix various glass raw materials so that the composition of the obtained glass member becomes the above-described glass composition.

[0047] "Use of Oxides" As the glass raw material, it is preferable to use oxides instead of hydroxides. This reduces the OH amount (H amount) of the glass raw material, making it easier to reduce the H content of the resulting glass member.

[0048] However, for the purpose of reducing the number of bubbles contained in the resulting glass member, a sulfur compound may be added to the glass raw material. From the perspective of reducing the amount of impurities contained in the resulting glass member, aluminum sulfate, for example, is preferable as the sulfur compound.

[0049] "Moisture Content" The moisture content of the glass raw material is preferably 200 mass ppm or less, more preferably 150 mass ppm or less, still more preferably 100 mass ppm or less, even more preferably 50 mass ppm or less, particularly preferably 30 mass ppm or less, very preferably 25 mass ppm or less, and most preferably 20 mass ppm or less, because it is easier to reduce the H content of the resulting glass member. The moisture content of the glass raw material can be adjusted by drying the glass raw material or the like. The moisture content of the glass raw material is determined by thermogravimetric analysis (TGA). Confirmed.

[0050] "Mixing Conditions" When mixing the glass raw materials, it is preferable to use a stirrer and stir for 10 minutes or more under the condition of 10 - 100 rpm. This sufficiently mixes the glass raw materials and makes it easier to reduce the variation in the refractive index of the resulting glass member. The glass raw materials may also be mixed by putting them in a bag and shaking. At this time, it is preferable to shake 100 times or more. This sufficiently mixes the glass raw materials and makes it easier to reduce the variation in the refractive index of the resulting glass member.

[0051] 〈Melting〉 Next, the mixed glass raw materials are heated and melted. At this time, defoaming, homogenization, etc. may be appropriately performed on the melt by a known method. Thus, molten glass is obtained.

[0052] 《Type of Atmosphere Gas》 The atmosphere when melting the glass raw material (also referred to as the "melting atmosphere") is, for example, air (atmospheric atmosphere). Gas (also referred to as "atmosphere gas") may be introduced into the melting atmosphere. Examples of the atmosphere gas include nitrogen gas (N2), oxygen gas (O2), compressed air, water vapor (H2O), etc. These may be used alone or in combination of two or more. When N2 and O2 are used in combination, the volume ratio of the two (N2 / O2) is, for example, 8 / 2. Among these, at least one selected from the group consisting of N2, O2, and compressed air is preferable because it is easy to reduce the H content of the obtained glass member. The atmosphere gas may be bubbled into the glass raw material (molten glass), or may be simply flowed onto the surface of the container (such as a crucible) containing the glass raw material.

[0053] 《Flow Rate of Atmosphere Gas》 The flow rate SLM of the atmosphere gas (flow rate per minute at 1 atm and 0°C) is, for example, 0.1 L / min or more, preferably 1 L / min or more, more preferably 3 L / min or more, still more preferably 5 L / min or more, even more preferably 10 L / min or more, particularly preferably 15 L / min or more, very preferably 20 L / min or more, and most preferably 25 L / min or more. On the other hand, the flow rate of the atmosphere gas is preferably 60 L / min or less, more preferably 55 L / min or less, still more preferably 50 L / min or less, particularly preferably 45 L / min or less, and most preferably 40 L / min or less.

[0054] 《Temperature of Atmosphere Gas》 From the viewpoint of keeping the glass melting temperature constant, the temperature of the atmosphere gas is preferably 30°C or more, more preferably 35°C or more, and still more preferably 40°C or more. On the other hand, from the viewpoint of reducing the manufacturing cost, the temperature of the atmosphere gas is preferably 100°C or less, more preferably 80°C or less, and still more preferably 60°C or less.

[0055] "Melting Temperature" When heating and melting the glass raw material, the temperature (melting temperature) is preferably 1500 °C or higher, more preferably 1550 °C or higher, and still more preferably 1600 °C or higher. Thereby, the glass raw material is sufficiently melted, and it is easy to reduce the variation in the refractive index of the obtained glass member. On the other hand, from the viewpoint of manufacturing cost and the like, the melting temperature is preferably 1800 °C or lower, more preferably 1750 °C or lower, and still more preferably 1700 °C or lower.

[0056] "Melting Time" The time (melting time) for heating and melting the glass raw material is preferably 2 hours or more, more preferably 2.5 hours or more, and still more preferably 3 hours or more. Thereby, the glass raw material is sufficiently melted, and it is easy to reduce the variation in the refractive index of the obtained glass member. Further, since the molten glass can be sufficiently clarified, it is easy to reduce the number of bubbles contained in the obtained glass member. On the other hand, for the reason of excellent manufacturing cost, the melting time is preferably 24 hours or less, more preferably 12 hours or less, still more preferably 10 hours or less, even more preferably 8 hours or less, particularly preferably 6 hours or less, and most preferably 4 hours or less.

[0057] "Stirring" When heating and melting the glass raw material, it is preferable to stir for 1 hour or more under the condition of 20 to 60 rpm using a stirrer. Thereby, the glass raw material is sufficiently melted, and it is easy to reduce the variation in the refractive index of the obtained glass member.

[0058] "Crushing and Remelting" The obtained molten glass may be crushed one or more times, and then the crushed material may be remelted. Thereby, it is easy to reduce the variation in the refractive index of the obtained glass member.

[0059] 〈Cooling〉 Thereafter, the obtained molten glass is cooled. At this time, it is preferable to cool (quench) the molten glass from the above-described melting temperature to the cooling stop temperature described later. Then, it is cooled to room temperature (for example, 25°C) as appropriate.

[0060] 《Cooling Stop Temperature》 The cooling stop temperature is, for example, 700 to 900°C, and preferably 750 to 850°C.

[0061] 《Cooling Rate》 From the viewpoint of reducing the crystals contained in the obtained glass member, the cooling rate from the melting temperature to the cooling stop temperature is preferably 100°C / min or more, and more preferably 200°C / min or more. On the other hand, from the viewpoints of suppressing variations in the glass composition in the obtained glass member and being easy to control when manufacturing the glass member, this cooling rate is preferably 1500°C / min or less, more preferably 1000°C / min or less, still more preferably 800°C / min or less, and particularly preferably 500°C / min or less. Note that if the cooling rate is within the above range, variations in the glass composition due to heat convection during pouring are suppressed, and it is easy to reduce variations in the refractive index of the obtained glass member.

[0062] 《Forming》 It is preferable to cool the molten glass after forming it into a desired shape. The forming method is not particularly limited, and examples include the float method, the press method, the fusion method, the down-draw method, etc. Note that the obtained molten glass may be formed into a temporary shape, then cooled, and the obtained temporary shaped body may be subjected to processing such as cutting.

[0063] 《Slow Cooling》 The formed glass may be slowly cooled to remove the strain in the glass. At this time, for example, the glass is held at an arbitrary temperature for a certain period of time, and then cooled to room temperature (for example, 25°C). The temperature for holding the glass (holding temperature) is preferably a temperature near the glass transition point because strain can be efficiently removed. Specifically, for example, a temperature in the range of 700 to 1100 °C is preferred, and a temperature in the range of 850 to 950 °C is more preferred. The time for holding the glass at the holding temperature (holding time) is, for example, 1 to 10 hours, and preferably 2 to 5 hours. The holding time is preferably longer as the shape of the glass is larger and more complex. The cooling rate from the holding temperature to room temperature is, for example, 0.1 to 5 °C / min, and preferably 0.5 to 1 °C / min.

[0064] In this way, a glass member having a desired shape is obtained. If necessary, the obtained glass member may be subjected to processes such as grinding and polishing.

[0065] 《logη at the time of pouring》 The viscosity logη of the molten glass when pouring for cooling or the like is preferably 0.5 Pa·s or more. This is to suppress variations in the glass composition due to heat convection during pouring and to reduce variations in the refractive index of the obtained glass member.

Examples

[0066] Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the examples described below.

[0067] [Test A: Examples A1 to A11] Hereinafter, Examples A1 to A10 are examples, and Example A11 is a comparative example. Glass raw materials were weighed and mixed so that the glass composition of the obtained glass member was SiO2: 59 mol%, Y2O3: 22 mol%, and Al2O3: 19 mol%. The moisture content of the glass raw materials is shown in Table 1 below. The mixed glass raw materials were put into a platinum crucible and charged into an electric furnace, and melted by heating at a melting temperature of 1600 °C (melting time: 3 hours) to obtain molten glass. Atmospheric gas was introduced into the melting atmosphere under the conditions shown in Table 1 below. However, when melting was carried out in the air atmosphere without introducing the atmosphere gas, it was described as "air" in Table 1 below. Also, when nitrogen gas (N2) and oxygen gas (O2) were used in combination at a volume ratio of 8 / 2 (N2 / O2), it was described as "N2 + O2" in Table 1 below. The obtained molten glass was cooled at a cooling rate of 250 °C / min from the melting temperature to the cooling stop temperature of 800 °C, and then further cooled to room temperature (25 °C) to obtain a glass member (dimensions: 100 mm × 100 mm × 15 mm). The H content and the content of element b (Na, Fe, and Ti) in the obtained glass member are shown in Table 1 below.

[0068] 〈Etching Rate〉 A test piece with a size of 20 mm × 20 mm × 2 mm was cut out from the glass member, and the surface of 20 mm × 20 mm was polished to a mirror finish. A part of the mirror-finished surface was masked by sticking Kapton tape, and etching was performed with a plasma gas under the following conditions. · Equipment: CCP-RIE · Gas type: CF4 (100 sccm) · Output: 350 W · Pressure: 10 Pa · Time: 130 minutes · Temperature: 20 °C Thereafter, the etching amount (wear amount) was obtained by measuring the step difference generated between the etched portion and the non-etched portion using a stylus-type surface profile measuring instrument (manufactured by ULVAC, Dectak150). Furthermore, the etching amount of the quartz glass was also obtained in the same manner. The ratio of the etching amount of the glass member to the etching amount of the quartz glass was obtained as the etching rate. The results are shown in Table 1 below. The smaller the value of the etching rate, the better the plasma resistance can be evaluated.

[0069]

Table 1

[0070] <Summary of Evaluation Results> As shown in Table 1 above, the glass members of Examples A1 to A10 with an H content of 200 mass ppm or less had a smaller etching rate value and better plasma resistance than the glass member of Example A11 with an H content exceeding 200 mass ppm.

[0071] [Test B: Examples B1 to B11] Hereinafter, Examples B1 to B11 are examples. A glass member was obtained in the same manner as in Example A3 of Test A, except that the glass raw materials were weighed so as to have the composition shown in Table 2 below. However, the cooling rate from the melting temperature to the cooling stop temperature was set to the rate shown in Table 2 below. The H content, average refractive index, refractive index variation, Young's modulus, expansion coefficient, transmittance, number of bubbles, crystal ratio, and etching rate in the obtained glass member are shown in Table 2 below.

[0072] [Table 2]

[0073] <Summary of Evaluation Results> As shown in Table 2 above, the glass members of Examples B1 to B11 with an H content of 200 mass ppm or less had good plasma resistance.

[0074] [Test C: Examples C1 to C20] Hereinafter, Examples C1 to C20 are examples. A glass member having the dimensions shown in Table 3 below was obtained in the same manner as in Example A3 of Test A, except that the glass raw materials were weighed so as to have the composition shown in Table 3 below. For the obtained glass member, its surface was processed so that the surface roughness (Ra) and flatness became the values shown in Table 3 below. However, the melting time was set to the temperature shown in Table 3 below. Also, the cooling rate from the melting temperature to the cooling stop temperature was set to the rate shown in Table 3 below. The H content, average refractive index, refractive index variation, Young's modulus, expansion coefficient, transmittance, number of bubbles, crystal ratio, and etching rate in the obtained glass member are shown in Table 3 below.

[0075]

Table 3

[0076] 〈Summary of Evaluation Results〉 As shown in Table 3 above, the glass members of Examples C1 to C20 with an H content of 200 mass ppm or less had good plasma resistance.

[0077] As described above, various embodiments have been explained, but it goes without saying that the present invention is not limited to such examples. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and it is naturally understood that they also belong to the technical scope of the present invention. Also, within the scope not departing from the gist of the invention, the constituent elements in the above embodiments may be arbitrarily combined.

[0078] This application is based on a Japanese patent application filed on April 19, 2023 (Japanese Patent Application No. 2023-068600), the content of which is incorporated herein by reference.

Claims

1. A glass member used in a semiconductor manufacturing apparatus, wherein the hydrogen content is 200 mass ppm or less, SiO ２ The content thereof is 40 to 70 mol%, Y ２ O ３ The content of which is 5 to 40 mol%, Al ２ O ３ A glass member in which the content of ２ is 10 to 30 mol%.

2. The glass member according to claim 1, wherein the content of at least one element a selected from the group consisting of tantalum, boron, magnesium, calcium, strontium, and barium in terms of oxide is 10 mol% or less.

3. The glass member according to claim 1 or 2, wherein the content of at least one element b selected from the group consisting of alkali metal elements, iron, and titanium in terms of oxide is 3000 mass ppm or less.

4. The Young's modulus is 100 GPa or more, and the average coefficient of thermal expansion at 50 to 350 °C is 4 to 7 ppm / K. The glass member according to claim 1 or 2.

5. The refractive index at a wavelength of 365 nm has an average of 1.5 or more, and the difference between the upper limit value and the lower limit value is 0.2 or less. The glass member according to claim 1 or 2.

6. The molar ratio Y / Si of the content of yttrium to the content of silicon is 0.2 to 1.

5. The glass member according to claim 1 or 2.

7. 10 cm ２ The glass member according to claim 1 or 2, having the cross-sectional area described above.

8. It is ring-shaped with an outer diameter of 300 to 600 mm, an inner diameter of 200 to 450 mm, and a thickness of 2 to 30 mm, chamfering with C1.0 or less is performed, the surface roughness Ra is 1 μm or less, and the flatness is 0.5 mm or less. The glass member according to claim 1 or 2.

9. The glass member according to claim 1 or 2, wherein the transmittance at a wavelength of 800 nm is 92% or less.

10. Any 100 mm ２ In 10 area regions, the number of bubbles of 0.1 mm ２ or more is 40 or less in total. The glass member according to claim 1 or 2.

11. Any 100 mm ２ In 10 area regions, the crystal area ratio of 0.1 mm ２ or more is 5% or less on average. The glass member according to claim 1 or 2.

12. The glass member according to claim 1 or 2, which is used as a focus ring, a shower plate, an electrostatic chuck, a susceptor, an injector, a viewing window, a top plate, or a side wall provided in the semiconductor manufacturing apparatus.

13. A method for manufacturing the glass member according to claim 1, wherein the glass raw material is melted by heating at a melting temperature of 1500 to 1800 °C, and the obtained molten glass is cooled at a cooling rate of 100 to 1500 °C / min to a cooling stop temperature of 700 to 900 °C. A method for manufacturing a glass member.

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