Plasma-resistant member

Abstract

To provide a plasma-resistant member that suppresses corrosion and particles of a plasma-resistant member.SOLUTION: In a plasma-resistant member, a sintered body has the content of magnesium oxide (MgO) of at least 95 when the total mass of the sintered body is taken as 100, and has a thermal conductivity of at least 59 W / m K at 25°C. The sintered body may also have a thermal conductivity of at least 33 W / m K at 200°C. The sintered body may have a total content of silicon (Si) and potassium (K), expressed in terms of silicon dioxide (SiO2) and potassium oxide (K2O), of 0.06 or more and 0.6 or less when a mass of magnesium oxide (MgO) is taken as 100.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a plasma-resistant member. [Background technology]

[0002] Semiconductor manufacturing equipment used in dry processes and plasma coating in semiconductor manufacturing employs highly reactive halogen-based plasma for etching and cleaning. Therefore, the components used in such equipment must be highly corrosion-resistant, and even higher corrosion resistance is required for components that come into contact with silicon (Si) wafers, such as electrostatic chucks and heaters, as well as the chambers and chamber parts that cover them. Sintered bodies of alumina (Al2O3) and yttria (Y2O3) are known to meet these corrosion-resistant requirements. Semiconductor manufacturing equipment using sintered bodies of Y2O3 are disclosed, for example, in Patent Documents 1 to 3. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-278935 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-179080 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-69843 Summary of the Invention [Problem to be solved by the invention]

[0004] Although corrosion-resistant members can be obtained by the techniques described in Patent Documents 1 to 3, there is a need for techniques that further suppress corrosion and particle generation. Note that this problem is not limited to semiconductor manufacturing equipment, but is a common problem with various members that are exposed to halogen-based plasma, such as base materials to be plasma-coated and water-repellent members such as nozzles that irradiate plasma gas. [Means for solving the problem]

[0005] The present disclosure has been made to solve at least one of the above-mentioned problems, and can be realized in the following forms.

[0006] (1) One embodiment of the present disclosure provides a plasma-resistant member including a sintered body. In this plasma-resistant member, the sintered body has a magnesium oxide (MgO) content of 95 or more and a thermal conductivity of 59 W / m·K or more at 25°C, where the mass of the entire sintered body is taken as 100. Here, the plasma-resistant member refers to a part that is corrosion-resistant (hard to be etched) by plasma such as a halogen-based gas.

[0007] This plasma-resistant member can reduce the etching rate compared to using a sintered body primarily containing alumina (Al2O3) or yttria (Y2O3) or a sintered body with a magnesium oxide (MgO) content of less than 95%. Furthermore, because the thermal conductivity is 59 W / m·K or higher at 25°C, plasma can be uniformly irradiated onto the sintered body at room temperature (25°C), suppressing the rate of change in surface roughness. This means that the plasma-resistant member's resistance to halogen-based gas corrosion (also known as plasma resistance) can be improved. Therefore, when the plasma-resistant member is exposed to halogen-based plasma, corrosion and particle generation can be reduced, improving the durability of the plasma-resistant member.

[0008] (2) In the plasma-resistant member of the above aspect, the sintered body may have a thermal conductivity of 33 W / m K or more at 200°C. This makes it possible to suppress changes in surface roughness even when the plasma-resistant member is heated to a high temperature (about 200°C) due to plasma irradiation.

[0009] (3) In the plasma-resistant member of the above aspect, the sintered body may have a total silicon (Si) and potassium (K) content converted to silicon dioxide (SiO2) and potassium oxide (KO), respectively, of 0.06 or more and 0.6 or less when the mass of magnesium oxide (MgO) is taken as 100. In this way, a decrease in thermal conductivity can be suppressed, and therefore, a change in surface roughness can be suppressed while ensuring sinterability, and plasma resistance can be improved.

[0010] The present invention can be realized in various forms, for example, in the form of a semiconductor manufacturing equipment component, a semiconductor manufacturing equipment, a holding device, an electrostatic chuck, a water-repellent member, an apparatus including any of these, a method for manufacturing a semiconductor manufacturing equipment component, a method for manufacturing a water-repellent member, etc. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an explanatory diagram schematically illustrating a plasma device including a plasma-resistant member. [Figure 2] FIG. 10 is a diagram showing the evaluation results of the examples. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Embodiment> 1 is an explanatory diagram schematically illustrating a plasma device 100 equipped with a plasma-resistant member according to an embodiment of the present disclosure. The plasma device 100 includes a reaction vessel 20 equipped with a vessel body 21 and a lid member 22, a holding device 30 for holding a substrate W, and a gas nozzle 10 as a plasma-resistant member.

[0013] Examples of the plasma device 100 include a film forming device for forming a thin film on a substrate W such as a semiconductor wafer or a glass substrate in a semiconductor manufacturing process, a water-repellent processing process, or a liquid crystal manufacturing process, or an etching device for performing micro-processing on a substrate W.

[0014] For example, in a film forming apparatus, a source gas containing a halogen-based corrosive gas is introduced into a reaction vessel 20 using a gas nozzle 10, and a thin film is formed on a substrate W by a plasma CVD (Chemical Vapor Deposition) method in which the source gas is converted into plasma. Also, in an etching apparatus, a halogen-based corrosive gas is introduced into a reaction vessel 20 using a gas nozzle 10 as a source gas, and the corrosive gas is converted into plasma to form an etching gas, thereby performing microfabrication on the substrate W.

[0015] The gas nozzle 10 has a gas supply port 11 through which gas such as a corrosive gas is supplied from a gas supply unit not shown, a gas exhaust port 12 through which gas is discharged into the reaction vessel 20, and a nozzle hole 13 that connects the gas supply port 11 and the gas exhaust port 12.

[0016] In this embodiment, the gas nozzle 10 as a plasma-resistant member has a sintered body in at least a part of the portion exposed to the corrosive gas, for example, the portion including the nozzle hole 13 and the portion exposed to the inside of the reaction vessel 20, and the entire gas nozzle 10 may be made of a sintered body. Furthermore, another layer such as a coating layer may be provided on the surface of the sintered body.

[0017] The plasma-resistant member includes a sintered body, and the sintered body has a magnesium oxide (MgO) content of 95 or more and a thermal conductivity of 59 W / m·K or more at 25°C, assuming the mass of the entire sintered body to be 100. This allows for a lower etching rate compared to using a sintered body primarily containing alumina (Al2O3) or yttria (Y2O3) or using a sintered body with a magnesium oxide (MgO) content of less than 95. Furthermore, because the thermal conductivity is 59 W / m·K or more at 25°C, the sintered body is more easily irradiated with plasma, suppressing the rate of change in surface roughness. In other words, the halogen-based gas corrosion resistance (also referred to as plasma resistance) can be improved. Therefore, when the plasma-resistant member is exposed to halogen-based plasma, corrosion and particle generation can be reduced, improving the durability of the plasma-resistant member.

[0018] The thermal conductivity of the sintered body at 200°C is not particularly limited, but is preferably 33 W / m K or more. This makes it possible to suppress changes in surface roughness even when the plasma-resistant member is heated to a high temperature (about 200°C) by plasma irradiation.

[0019] The silicon (Si) and potassium (K) contents in the sintered body are not particularly limited. However, when the mass of magnesium oxide (MgO) is taken as 100, the total silicon (Si) and potassium (K) contents, converted into silicon dioxide (SiO2) and potassium oxide (KO), are preferably 0.06 to 0.6, respectively. While silicon dioxide (SiO2) and potassium oxide (KO) function as sintering aids, excessive amounts of these elements tend to increase the likelihood of the formation of a glass phase and decrease thermal conductivity. Therefore, by keeping the silicon (Si) and potassium (K) contents within the above ranges, sinterability can be maintained while suppressing a decrease in thermal conductivity. In other words, sinterability can be maintained while suppressing changes in surface roughness, resulting in improved plasma resistance. Here, since it is preferable to include a certain amount of silicon dioxide (SiO2) and potassium oxide (KO) as sintering aids from the viewpoint of sinterability, the silicon (Si) and potassium (K) contents are shown as the total converted into silicon dioxide (SiO2) and potassium oxide (KO). Furthermore, the ratio of silicon (Si) and potassium (K) contents to magnesium oxide (MgO) is important.

[0020] The sintered body may further contain sodium oxide (Na2O), alumina (Al2O3), calcium oxide (CaO), and the like.

[0021] As described above, the plasma-resistant member of this embodiment can reduce the etching rate and improve plasma resistance compared to using a sintered body mainly containing alumina (Al2O3) or yttria (Y2O3) or a sintered body with a magnesium oxide (MgO) content of less than 95%. Furthermore, since the thermal conductivity is 59 W / m·K or higher at 25°C, plasma is easily irradiated uniformly onto the gas nozzle 10, suppressing the rate of change in surface roughness. Therefore, when the gas nozzle 10, which is a plasma-resistant member, is exposed to halogen-based plasma, corrosion and particle generation can be reduced. Therefore, the product yield of the plasma device 100 can be improved. Furthermore, the frequency of replacement of the plasma-resistant member (gas nozzle 10) in the plasma device 100 can be reduced.

[0022] In the plasma device 100, the reaction vessel 20 and the holding device 30 may be made of plasma-resistant materials. [Example]

[0023] The present disclosure will be explained more specifically with reference to examples. 2 shows the evaluation results of samples S1 to S15. Using samples S1 to S15 of sintered bodies with different compositions and manufacturing conditions, the MgO amount, SiO2 content, K2O content, Na2O content, thermal conductivity, etching rate, and surface change rate were evaluated. Samples S13 to S15 are comparative examples that do not satisfy the conditions for the sintered bodies described in the embodiment.

[0024] 1. Sample Preparation The manufacturing method for porous sintered bodies involves the blending process followed by the hot-pressing process. First, in the blending process P1, inorganic components and a binder dispersant are added to a solvent and then ground and mixed using a ball mill. The inorganic components consist of the inorganic components that form the main phase, plus auxiliary materials such as silicon dioxide (SiO2), potassium oxide (K2O), and sodium oxide (Na2O). The inorganic components vary depending on the sample. In the hot-pressing process, the slurry obtained in the blending process is hot-pressed at 1250°C to 1540°C in an inert atmosphere (Ar, vacuum, etc.). This produces a sintered body. Hot-pressing applies pressure during firing, which crushes particles during firing compared to atmospheric pressure firing, promoting densification and reducing grain boundary pores. Furthermore, the contact area between particles is larger, allowing the sintering process itself to be completed in a shorter time than air firing. The sample size is 15mm x 15mm x 2mm (thickness).

[0025] [Samples S1, S2, S4-S11, S13] In samples S1 to S14 and S17, magnesium oxide (MgO) was used as the inorganic component that forms the main phase, with silicon dioxide (SiO2) and potassium oxide (KO) used as auxiliary components. The inorganic components were mixed in the proportions shown in Figure 2 and hot-pressed in an argon (Ar) atmosphere at 1250°C and 55 MPa for 3 hours.

[0026] [Samples S3, S12] Samples S3 and S12 used magnesium oxide (MgO) as the inorganic component that forms the main phase, with silicon dioxide (SiO2) and sodium oxide (Na2O) as auxiliary components. The inorganic components were mixed in the proportions shown in Figure 2 and hot-pressed for 3 hours at 1250°C and 55 MPa in an argon (Ar) atmosphere. In Figure 2, the Na2O content is shown in the K2O content column, and the total column shows the sum of SiO2 and Na2O.

[0027] [Sample S14] Sample S14 used yttria (YO) as the inorganic component that forms the main phase, with silicon dioxide (SiO) and potassium oxide (KO) as auxiliary components. The inorganic components were mixed in the proportions shown in Figure 2 and hot-pressed in a vacuum atmosphere at 1400°C and 50 MPa for 3 hours. In Figure 2, the SiO and KO contents are shown as a percentage of the YO content, which is taken as 100.

[0028] [Sample S15] Sample S15 used alumina (Al2O3) as the inorganic component that forms the main phase, with silicon dioxide (SiO2) and potassium oxide (K2O) as auxiliary components. The inorganic components were mixed in the proportions shown in Figure 2 and hot-pressed in an argon (Ar) atmosphere at 1540°C and 20 MPa for 4 hours. In Figure 2, the SiO2 and K2O contents are shown as a percentage when the Al2O3 content is taken as 100.

[0029] 2.Measurement method [MgO content, SiO2 content, K2O content, Na2O content] Quantitative analysis was performed using X-ray fluorescence analysis (XRF). In Figure 2, the MgO content is shown as a percentage of the entire sintered body, which is 100, and the SiO2 content, K2O content, and Na2O content are shown as percentages of the MgO content, which is 100.

[0030] [Thermal Conductivity] According to JIS-R1611, specimens were cut out from each sample and processed, and their thermal conductivity (W / m·K) was measured by the laser flash method.

[0031] [Etching rate] Each sample was partially masked and subjected to a plasma resistance test (etching) under the following conditions. After the plasma resistance test, the masking was removed from the sample, and the step between the etched and masked areas was measured using a stylus-type step gauge. This step was taken as the amount of etching. In Figure 2, the etching rate is expressed as a relative value based on the amount of etching of sample S14 (a sintered compact whose main phase is Y2O3). As shown in Figure 2, the etching rate of sample S14 is "1". Test conditions Microwave excited plasma: 2000W Bias: 200W Etching gas: NF3 Pressure: 20mtorr NF3 flow rate: 20sccm (standard cubic centimetre / min) Irradiation time: 10 hours

[0032] [Change in surface roughness before and after etching] The above plasma resistance test was carried out on each sample, and the surface roughness was measured before and after the test to determine the rate of change. The surface roughness was measured using an Alicona non-contact three-dimensional measuring machine manufactured by Eurotechno Corporation. Figure 2 shows the evaluation results for arithmetic mean height Ra, root mean square height Rq, and maximum height Rz. The evaluation was carried out according to the following criteria. ◎: Less than 20% 〇: 20% or more but less than 30% ●: 30% or more but less than 40% △: 40% or more but less than 50% ▽: 50% or more but less than 60% ×: 70% or more

[0033] 3.Measurement results As shown in FIG. 2, samples S1 to S13 satisfy the following requirement [1]. [1] When the mass of the entire sintered body is taken as 100, the content of magnesium oxide (MgO) is 95 or more. Samples S1 to S13 have smaller etching rates than sample S14. Sample S14 is a sintered body having Y2O3 as the main phase. It was confirmed that by satisfying the above requirement [1], it is possible to improve the plasma resistance compared to a sintered body having Y2O3 as the main phase. Furthermore, samples S1 to S13 have smaller etching rates than sample S15. Sample S14 is a sintered body having Al2O3 as the main phase. In other words, it was confirmed that by satisfying the above requirement [1], it is possible to improve the plasma resistance compared to a sintered body having Al2O3 as the main phase.

[0034] Samples S1 to S12 further satisfy the following requirement [2]. [2] The sintered body has a thermal conductivity of 59 W / m·K or more at 25°C. Samples S1 to S12 were evaluated as having a better rate of change in surface roughness than samples S13 and S15, and were equivalent to sample S14. Samples S13 to S15 had a lower thermal conductivity at 25°C than samples S1 to S12, lower than 59 W / m K. In other words, it was confirmed that by satisfying the above requirement [2], it was possible to reduce the rate of change in surface roughness before and after etching.

[0035] Samples S1 to S12 further satisfy the following requirement [3]. [3] The sintered body has a thermal conductivity of 33 W / m·K or more at 200°C. Samples S1 to S12 were evaluated as having a better rate of change in surface roughness than samples S13 and S15, and were equivalent to sample S14. Samples S13 to S15 had a lower thermal conductivity at 200°C than samples S1 to S12, lower than 33 W / m K. In other words, it was confirmed that by satisfying the above requirement [3], it was possible to reduce the rate of change in surface roughness before and after etching.

[0036] Samples S1 to S7 further satisfy the following requirement [4]. [4] When the mass of magnesium oxide (MgO) of the sintered body is taken as 100, the total content of silicon (Si) and potassium (K) converted to silicon dioxide (SiO2) and potassium oxide (KO), respectively, is 0.06 or more and 0.6 or less. The surface roughness change rate of samples S1 to S7 was evaluated to be even better than that of samples S8 to S12. The silicon (Si) and potassium (K) contents of samples S1 to S7, converted into silicon dioxide (SiO2) and potassium oxide (KO), respectively, were 0.06 or more and 0.6 or less in total. In other words, it was confirmed that by satisfying the above requirement [4], the surface roughness change rate before and after etching could be further reduced.

[0037] Furthermore, although samples S2 and S3 were different in the type of auxiliary agent, they had the same magnesium oxide (MgO) content and thermal conductivity, similar etching rates, and were evaluated as having the same rate of change in surface roughness. Similarly, although samples S11 and S12 were different in the type of auxiliary agent, they had the same magnesium oxide (MgO) content and thermal conductivity, and were evaluated as having the same etching rate and rate of change in surface roughness. This confirmed that if the above requirements [1] and [2] are met, plasma resistance can be improved and particles can be suppressed, regardless of the composition other than MgO.

[0038] From the evaluation results of the example shown in FIG. 2, it was confirmed that the surface roughness is less likely to change before and after etching by maintaining a high thermal conductivity with a small amount of components (auxiliaries, etc.) other than MgO.

[0039] <Modification of this embodiment> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0040] The method for producing the sintered body is not limited to the above-described examples. By appropriately changing the type and amount of additive, firing method, firing atmosphere, firing temperature, hot press pressure, etc., it is possible to produce a sintered body having a magnesium oxide (MgO) content of 95% or more when the mass of the entire sintered body is taken as 100%. Alternatively, the sintered body may be produced by other known methods, such as gel casting.

[0041] In the above examples, the sintered body contains Si, K, and Na in addition to magnesium oxide (MgO), but other components may also be included. For example, various metals contained in sintering aids (e.g., Ca, Al, Zn, Ti, etc.) may also be included. Furthermore, unavoidable impurities such as components contained in raw materials and components mixed in during the manufacturing process may also be included.

[0042] The present disclosure has been described above based on embodiments, examples, and modifications. However, the above-described embodiments are intended to facilitate understanding of the present disclosure and are not intended to limit the present disclosure. The present disclosure may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in the present disclosure. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

[0043] The present invention can also be realized as the following application examples. [Application example 1] A plasma-resistant member including a sintered body, The sintered body is When the mass of the entire sintered body is taken as 100, the content of magnesium oxide (MgO) is 95 or more, A thermal conductivity of 59 W / m·K or more at 25°C. Plasma resistant materials. [Application example 2] The plasma-resistant member according to Application Example 1, The sintered body is A thermal conductivity of 33 W / m K or more at 200°C. Plasma resistant materials. [Application example 3] The plasma-resistant member according to Application Example 1 or Application Example 2, The sintered body is The total content of silicon (Si) and potassium (K) converted into silicon dioxide (SiO2) and potassium oxide (KO) is 0.06 or more and 0.6 or less when the mass of magnesium oxide (MgO) is 100, Plasma resistant materials. [Explanation of symbols]

[0044] 10...Gas nozzle 11...Gas supply port 12...Gas outlet 13...Nozzle hole 20...Reaction vessel 21...Container body 22...Lid part 100...Plasma device W...Substrate

Claims

1. A plasma-resistant member including a sintered body, The sintered body is When the mass of the entire sintered body is taken as 100, the content of magnesium oxide (MgO) is 95 or more, A thermal conductivity of 59 W / m K or more at 25°C. Plasma resistant materials.

2. The plasma-resistant member according to claim 1, The sintered body is The thermal conductivity is 33 W / m K or more at 200°C. Plasma resistant materials.

3. The plasma-resistant member according to claim 1 or 2, The sintered body is When the mass of magnesium oxide (MgO) is 100, the contents of silicon (Si) and potassium (K) are respectively 100% of silicon dioxide (SiO 2 ) and potassium oxide (K 2 O), the total of which is 0.06 or more and 0.6 or less, Plasma resistant materials.

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