TWI638795B - Structure - Google Patents

Abstract

A structure comprising a polycrystal of a fluorinated fluorinated crystal having a rhombohedral crystal structure, wherein an average crystallite size of the polycrystal is less than 100 nm, and X-ray diffraction at a diffraction angle The peak intensity of the rhombohedral crystal detected near 2θ=13.8° is r1, and the peak intensity of the rhombohedral crystal detected near the diffraction angle 2θ=36.1° is r2, and the ratio γ1 is γ1 (%)=r2/ When r1 × 100, the ratio γ1 is 0% or more and less than 100%.

Description

Structure

Embodiments of the present invention generally relate to structures.

As a member used in a plasma irradiation environment such as a semiconductor manufacturing apparatus, a member having a coating film having a high plasma resistance on its surface can be used. As the coating film, for example, an oxide such as alumina (Al ₂ O ₃ ), yttria (Y ₂ O ₃ ), or a nitride such as aluminum nitride (AlN) can be used.

On the other hand, in oxide-based ceramics, fluorination caused by the reaction with CF-based gases causes the membrane to expand in volume and generate cracks. As a result, particles are generated. This has been proposed. A fluoride-based ceramic such as yttrium fluoride (YF ₃ ) which has been fluorinated is used (Patent Document 1).

In addition, although YF ₃ has high resistance to F-based plasmas, it has insufficient resistance to Cl-based plasmas, or has doubts about the chemical stability of fluorides, etc. In this regard, the use of yttrium Coating film or sintered body of oxyfluoride) (YOF) (Patent Literature 2, Patent Literature 3).

So far, YF ₃ or YOF has been reviewed for thermal spraying films and sintered bodies. However, plasma spray resistance in a spray film or a bulk body is often insufficient, and it is required to further improve plasma resistance. For example, the formation of a thermal spray film using a rare earth element oxyfluoride as a raw material has been reviewed (Patent Document 4). However, oxidation occurs due to oxygen in the atmosphere when heated in a melt shot. Therefore, mixing Y ₂ O ₃ into the resulting spray film often makes it difficult to control the composition. In addition, there is still a problem in the denseness of the spray film. Furthermore, if a reaction chamber (coating) which is coated with YF _{3 by} spraying or the like is used for plasma etching, there is also a problem that the etching rate drifts and becomes unstable (Patent Document 5). In addition, a method of fluorinating the film including Y ₂ O ₃ by anneal such as plasma treatment is also examined (Patent Document 6). However, in this method, the film containing Y ₂ O ₃ was subjected to a fluorination treatment, so that the volume of the film changed due to the fluorination and peeled off from the substrate, or cracks occurred in the film. Risk of adverse conditions. Moreover, it is often difficult to control the composition of the entire membrane. Further, in the thermal spray or sintered body, the F ₂ gas is released due to the thermal decomposition of the fluoride raw material particles during heating, and there is a problem of safety.

On the other hand, Patent Document 7 discloses that Y ₂ O ₃ can be formed into a plasma-resistant structure at an ordinary temperature by an aerosol deposition method. However, the aerosol deposition method using yttrium oxyfluoride has not been fully reviewed. .

Patent Document 1: Japanese Patent Application Publication No. 2013-140950 Patent Document 2: Japanese Patent Application Publication No. 2014-009361 Patent Document 3: Japanese Patent Application Publication No. 2016-098143 Patent Document 4: Japanese Patent Publication No. 5927656 Patent Document 5: US Patent Application Publication No. 2015/0126036 Patent Document 6: US Patent Application Publication No. 2016/273095 Patent Document 7: Japanese Patent Application Laid-Open No. 2005-217351

Plasma resistance may be uneven in a structure containing yttrium oxyfluoride. The present invention has been made based on the recognition of such problems, and an object thereof is to provide a structure capable of improving plasma resistance.

The first invention is a structure comprising a polycrystal of yttrium oxyfluoride having a crystal structure of rhombohedral crystal as a main component. The average crystallite size is less than 100 nanometers, and the peak intensity of the rhombohedral crystal detected by X-ray diffraction around the diffraction angle 2θ = 13.8 ° is r1. When the peak intensity of the rhombohedral crystal detected near the diffraction angle 2θ = 36.1 ° is r2, and the ratio γ1 is γ1 (%) = r2 / r1 × 100, the ratio γ1 is 0% or more and less than 100%. The second invention is a structure. In the first invention, the aforementioned ratio γ1 is less than 80%.

The present inventors have found that a predetermined peak intensity ratio (ratio γ1) of yttrium oxyfluoride of rhombohedral crystals is related to the plasma resistance. It was found that when the ratio γ1 is 100% or more, the plasma resistance performance becomes low. By setting the ratio γ1 to be 0% or more and less than 100%, preferably less than 80%, it is possible to develop practically excellent plasma resistance.

The third invention is a structure. In the first or second invention, the aforementioned structure does not include yttrium oxyfluoride having an orthorhombic crystal structure, or further includes yttrium oxyfluoride having an orthorhombic crystal structure. The peak intensity of the orthorhombic crystal detected near the diffraction angle 2θ = 16.1 ° is о, and when the ratio of the orthorhombic to rhombohedral crystal is γ2 (%) = о / r1 × 100, the aforementioned ratio γ2 is Above 0% and below 100%. The present inventors have found that there is a correlation between the ratio of the compound or crystal phase (ratio γ2) in the structure and the plasma resistance. It was found that when the ratio γ2 is 100% or more, the plasma resistance is lowered. By setting the ratio γ2 to be 0% or more and less than 100%, the plasma resistance can be improved.

The fourth invention is a structure. In any one of the first to third inventions, the aforementioned yttrium oxyfluoride having a crystal structure of rhombohedral crystals is YOF. A fifth invention is a structure. In the third invention, the aforementioned yttrium oxyfluoride having an orthorhombic crystal structure is a YOF of 1: 1: 1. According to these structures, plasma resistance can be improved.

The sixth invention is a structure, and in the third invention, the aforementioned ratio γ2 is 85% or less. The seventh invention is a structure, and in the third invention, the aforementioned ratio γ2 is 70% or less. The eighth invention is a structure, and in the third invention, the aforementioned ratio γ2 is 30% or less. According to these structures, the plasma resistance can be further improved.

The ninth invention is a structure. In any one of the first to eighth inventions, the average crystallite size is less than 50 nm. The tenth invention is a structure. In any one of the first to eighth inventions, the average crystallite size is less than 30 nm. The eleventh invention is a structure. In any one of the first to eighth inventions, the average crystallite size is less than 20 nm. According to these structures, by having a small average crystallite size, it is possible to reduce particles generated by the structure due to plasma.

The twelfth invention is a structure. In any one of the first to eleventh inventions, when the peak intensity detected by X-ray diffraction around a diffraction angle of 2θ = 29.1 ° is ε, At least one of the ratio of the ε to the r1 and the ratio of the ε to the r2 is less than 1%. According to this structure, since the Y ₂ O ₃ contained in the structure is small, the fluorination by the CF-based plasma is suppressed, and the plasma resistance can be further improved.

The thirteenth invention is a structure. In any one of the first to eleventh inventions, when the peak intensity detected by X-ray diffraction around a diffraction angle of 2θ = 29.1 ° is ε, At least one of the ratio of the ε to the r1 and the ratio of the ε to the r2 is 0%. According to this structure, since Y ₂ O ₃ is not substantially contained, the fluorination by the CF-based plasma is suppressed, and the plasma resistance can be further improved.

According to an aspect of the present invention, a structure including yttrium oxyfluoride having a crystal structure with rhombohedral crystals can be provided, and the plasma resistance can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in the drawings, the same constituent elements are assigned the same reference numerals, and detailed descriptions are appropriately omitted. FIG. 1 is a cross-sectional view illustrating a member having a structure according to an embodiment. As shown in FIG. 1, the member 10 is, for example, a composite structure having a base material 15 and a structure 20. The member 10 is, for example, a member for a semiconductor manufacturing apparatus having a reaction chamber, and is provided inside the reaction chamber. Since the plasma is generated by introducing a gas into the reaction chamber, the component 10 is required to be resistant to plasma. In addition, the member 10 (structure 20) may be used outside the reaction chamber, and the semiconductor manufacturing apparatus includes annealing, etching, sputtering, CVD (Chemical Vapor Deposition), and the like. Arbitrary semiconductor manufacturing equipment (semiconductor processing equipment). Moreover, the component 10 (structure 20) can also be used for components other than a semiconductor manufacturing apparatus.

The substrate 15 contains, for example, alumina. However, the material of the substrate 15 is not limited to ceramics such as alumina, and may be quartz, alumite, metal, glass, or the like. In this example, a member 10 having a base material 15 and a structure 20 will be described. The embodiment in which only the structure 20 is not provided with the base material 15 is also included. The arithmetic mean roughness Ra (JISB0601: 2001) of the surface of the substrate 15 (the surface on which the structure 20 is formed) is, for example, less than 5 μm, more preferably less than 1 μm, and more preferably It is less than 0.5 μm.

The structure 20 includes a polycrystal of yttrium oxyfluoride having a crystal structure of rhombohedral crystal. The main component of the structure 20 is a polycrystal of yttrium oxyfluoride (YOF) having a crystal structure of rhombohedral crystals.

In the description of this case, the main component of a structure refers to quantitative or quasi-quantitative analysis by X-ray Diffraction (XRD) of the structure, which is relatively more than other compounds contained in the structure 20 Contained compounds. For example, the main component is the compound that contains the most in the structure, and the ratio of the main component in the structure is greater than 50% by volume ratio or mass ratio. The ratio of the main component is more preferably more than 70%, and more than 90% is also suitable. The ratio of the main component may be 100%.

In addition, yttrium oxyfluoride means a compound of yttrium (Y), oxygen (O), and fluorine (F). Examples of yttrium oxyfluoride include YOF (Molar ratio Y: O: F = 1: 1: 1) and YOF (Molar ratio Y: O: 1: 1). : F = 1: 1: 2). In addition, in the description of this case, the range of Y: O: F = 1: 1: 2 is not limited to the composition where Y: O: F is exactly 1: 1: 1, and may also include fluorine to yttrium. A composition having a ratio (F / Y) of more than 1 and less than 3. For example, Y: O: F = 1: 1: 2 yttrium oxyfluoride includes Y ₅ O ₄ F ₇ (Molar ratio is Y: O: F = 5: 4: 7), Y ₆ O ₅ F ₈ (Molar ratio Y: O: F = 6: 5: 8), Y ₇ O ₆ F ₉ (Molar ratio Y: O: F = 7: 6: 9), Y ₁₇ O ₁₄ F ₂₃ (Mole ratio is Y: O: F = 17: 14: 23) and so on. Moreover, in the description of this case, it means Y: O: F = 1: 1: 1 when it is called only [YOF], and it means when it is called [1: 1: 2 YOF]. The above Y: O: F = 1: 1: 2. In addition, a composition other than the above may be included in this range of yttrium oxyfluoride.

Although the structure 20 has a single-layer structure in the example of FIG. 1, the structure formed on the base material 15 may have a multilayer structure (see FIG. 6). For example, another layer 22 (for example, a layer containing Y ₂ O ₃ ) may be provided between the substrate 15 and the layer 21 corresponding to the structure 20 in FIG. 1. The layer 21 corresponding to the structure 20 forms the surface of the structure 20a having a multilayer structure.

The structure 20 is formed of, for example, a raw material containing yttrium oxyfluoride. This raw material can be produced, for example, by subjecting yttrium oxide to a fluorination treatment. By this process, the raw materials are roughly divided into two types: raw materials with high oxygen content and raw materials with low oxygen content. The raw material having a large oxygen content includes, for example, YOF and YOF (1: 1: 2) (for example, Y ₅ O ₄ F ₇ , Y ₇ O ₆ F _9, and the like). The oxygen-rich raw material may include only YOF. In addition, the raw material having a small amount of oxygen contains, for example, Y ₅ O ₄ F ₇ , Y ₇ O ₆ F _9, and the like, and includes YF ₃ instead of YOF. When a sufficient fluorination process is performed, the raw material may include only YF ₃ and may not include yttrium oxyfluoride. In this embodiment, the structure includes rhombohedral yttrium oxyfluoride. The yttrium oxyfluoride containing a rhombohedral crystal in a raw material or a structure means that in X-ray diffraction, a peak is detected at at least one of a diffraction angle around 2θ = 13.8 ° and a diffraction angle around 2θ = 36.1 °.

In structures used in semiconductor manufacturing equipment and the like, YF ₃ , Y ₅ O ₄ F ₇ , Y ₇ O ₆ F _9, etc. are oxidized over the years and sometimes change to YOF. Furthermore, there are reports that YOF is superior in corrosion resistance (corrosion resistance) to other compositions (Patent Document 3).

The present inventors have found that in a structure containing yttrium oxyfluoride as a main component, there is a correlation between the plasma resistance and the crystal structure of the structure, and the plasma resistance can be improved by controlling the crystal structure. By controlling the crystal structure of yttrium oxyfluoride contained in the structure, the plasma resistance can be improved.

Specifically, the crystal structure of the structure 20 according to the embodiment is shown below. The structure 20 includes a polycrystal of yttrium oxyfluoride having a crystal structure of rhombohedral crystal. In the X-ray diffraction of the structure 20, the ratio γ1 of the peak intensity of the rhombohedral crystal is 0% or more and less than 100%, and preferably less than 80%.

Here, the ratio γ1 is calculated by the following method. The structure 20 containing yttrium oxyfluoride is subjected to X-ray diffraction by θ-2θ scanning. It is assumed that the peak intensity of the rhombohedral crystal detected by the X-ray diffraction of the structure 20 near the diffraction angle 2θ = 13.8 ° is r1. It is assumed that the peak intensity of the rhombohedral crystal detected by the X-ray diffraction of the structure 20 near the diffraction angle 2θ = 36.1 ° is r2. At this time, γ1 (%) = r2 / r1 × 100. For example, the ratio γ1 represents the degree of orientation of the yttrium oxyfluoride of the rhombohedral crystal.

In addition, it is considered that the spikes around the diffraction angle 2θ = 13.8 ° and the spikes around the diffraction angle 2θ = 36.1 ° are caused by, for example, YOF of the rhombohedral crystal. In addition, a diffraction angle around 2θ = 13.8 ° means, for example, about 13.8 ± 0.4 ° (above 13.4 °, 14.2 ° or less), and a diffraction angle around 2θ = 36.1 ° means, for example, about 36.1 ° ± 0.4 ° (above 35.7 °, 36.5 ° or less).

Furthermore, the structure 20 includes yttrium oxyfluoride having a crystal structure of rhombohedral crystals, and does not include yttrium oxyfluoride having a crystal structure of orthorhombic crystals. Alternatively, the structure 20 includes yttrium oxyfluoride having a crystal structure of rhombohedral crystal and yttrium oxyfluoride having a crystal structure of orthorhombic crystal, and the ratio of orthorhombic to rhombohedral crystal γ2 is 0% or more and less than 100%.

Here, the ratio γ2 can be calculated by the following method. The structure 20 containing yttrium oxyfluoride is subjected to X-ray diffraction (X-ray Diffraction: XRD) by θ-2θ scanning. Let the peak intensity of the rhombohedral crystal detected by X-ray diffraction around a diffraction angle of 2θ = 13.8 ° be r1. It is assumed that the peak intensity of the orthorhombic crystal detected by the X-ray diffraction around the diffraction angle 2θ = 16.1 ° is о. At this time, γ2 (%) = о / r1 × 100.

In addition, it may be considered that the spike near the diffraction angle 2θ = 16.1 ° is caused by the orthorhombic YOF of 1: 1: 1 (for example, at least either of the orthorhombic Y ₅ O ₄ F ₇ or Y ₇ O ₆ F ₉ One). The vicinity of the diffraction angle 2θ = 16.1 ° means, for example, about 16.1 ± 0.4 ° (15.7 ° or more and 16.5 ° or less).

The ratio γ2 of the orthorhombic crystal to the rhombohedral crystal is preferably 85% or less, more preferably 70% or less, still more preferably 30% or less, and most preferably 0%. In the present specification, γ2 = 0% means the lower limit of detection during measurement, and is synonymous with yttrium oxyfluoride which does not substantially include a crystal structure having an orthorhombic crystal.

In the polycrystal of yttrium oxyfluoride contained in the structure, the average crystallite size is, for example, less than 100 nm, preferably less than 50 nm, more preferably less than 30 nm, and most preferably less than 20 nm. With a small average crystallite size, particles generated by the plasma can be reduced.

In addition, X-ray diffraction can be used for the measurement of the crystallite size. As the average crystallite size, the crystallite size can be calculated by the following Scherrer formula. D = Kλ / (βcosθ) where D is the crystallite size, β is the half width of the peak (弪 (rad)), θ is the Bragg angle (rad), and λ is the wavelength of the X-ray used in the measurement . In the Scherrer formula, β is calculated by β = (βobs-βstd). βobs is the half-value width of the X-ray diffraction peak of the measurement sample, and βstd is the half-value width of the X-ray diffraction peak of the standard sample. K is the Xie Le constant. In yttrium oxyfluoride, the X-ray diffraction peaks used for the calculation of the crystallite size can be, for example, peaks caused by the mirror surface (006) near the diffraction angle 2θ = 28 °, and the diffraction angle 2θ = 29 °. Spikes near the mirror surface (012), spikes due to the mirror surface (018) near the diffraction angle 2θ = 47 °, spikes due to the mirror surface (110) near the diffraction angle 2θ = 48 °, and the like. The crystallite size can also be calculated from images such as TEM observations. For example, the average crystallite size can use the average value of the diameter of a crystallite corresponding to a circle.

The interval between adjacent crystallites is preferably 0 nm or more and less than 10 nm. The interval between adjacent crystallites means the closest interval between the crystallites, and does not include a void formed by a plurality of crystallites. The interval between the microcrystals can be obtained from an image obtained by observation using a transmission electron microscope (TEM). FIG. 7 shows a TEM image of an example of the structure 20 according to the embodiment. The structure 20 includes a plurality of microcrystals 20c (crystal grains).

Further, for example, the structure 20 does not substantially contain Y ₂ O ₃ . When X-ray diffraction is performed on the structure 20 by θ-2θ scanning, it is assumed that the peak intensity of Y ₂ O ₃ caused by the diffraction angle around 2θ = 29.1 ° is ε. At this time, at least any one of the ratio of ε to r1 (ε / r1) and the ratio of ε to r2 (ε / r2) is less than 1%, more preferably 0%. Since the structure 20 does not contain Y ₂ O ₃ or the structure 20 contains a small amount of Y ₂ O ₃ , the fluorination caused by the CF-based plasma is suppressed, and the plasma resistance can be further improved. The vicinity of 2θ = 29.1 ° means, for example, about 29.1 ± 0.4 ° (28.7 ° or more and 29.5 ° or less).

The structure 20 according to the embodiment can be formed, for example, by disposing fine particles such as a brittle material on the surface of the substrate 15 and applying a mechanical impact force to the fine particles. Here, the method of [applying mechanical impact force] includes, for example, using a brush or roller that rotates at a high speed and a high hardness, or a piston that moves up and down at a high speed, and utilizes a shock wave generated during an explosion. Compressive force or ultrasonic effect or a combination of these methods.

The structure 20 according to the embodiment is also preferably formed by, for example, an aerosol deposition method. [Aerosol deposition method] is a method of spraying nozzles (aerosol) toward a substrate to disperse particles containing brittle materials and the like in the gas, and to cause the particles to collide with a substrate such as metal, glass, ceramic, or plastic. The particles of the brittle material are deformed and / or broken by the impact of the collision to join the substrates, so that a structure (such as a layered structure or a film-like structure) of the constituent material containing the particles is directly formed on the substrate On the method. According to this method, a heating means, a cooling means, and the like are not particularly required, and a structure can be formed at normal temperature, and a structure having a mechanical strength equal to or higher than that of a sintered body can be obtained. In addition, the density, mechanical strength, and electrical characteristics of the structure can be changed in various ways by controlling the conditions under which the particles collide, the shape and composition of the particles.

In the present specification, [polycrystalline] refers to a structure in which crystal grains are bonded and accumulated. The diameter of the crystal grains is, for example, 5 nanometers (nm) or more.

In addition, in the description of this case, [microparticles] means that when the primary particles are dense plasmids, the average particle diameter identified by particle size distribution measurement or scanning electron microscope is 5 micrometers (μm) or less. When the primary particles are porous particles that are easily broken by impact, the average particle diameter is 50 μm or less.

[Aerosol] in this specification refers to a gas (carrier gas (carrier gas (Hydrogen), etc.) in which the aforementioned fine particles are dispersed in a mixed gas containing helium, nitrogen, argon, oxygen, and dry air. carrier gas)) may contain a part of the [aggregate], but the particles are essentially dispersed separately. The gas pressure and temperature of the aerosol are arbitrary, but the concentration of the fine particles in the gas is 0.0003 mL when the gas pressure is converted to 1 barometric pressure and the temperature is converted to 20 degrees Celsius. The range of / L ~ 5mL / L is ideal for the formation of structures.

The aerosol deposition process is usually carried out at normal temperature, and has a feature at a temperature far below the melting point of the particulate material, that is, the formation of structures below several hundred degrees Celsius. In addition, in this specification, "normal temperature" refers to a temperature at which the sintering temperature of ceramics is significantly low, and is substantially a room temperature environment of 0 to 100 ° C. [Powder] in the specification of the present case refers to a state in which the aforementioned fine particles are spontaneously agglutination.

The following describes the review by the inventors of this case. FIG. 2 is a table illustrating raw materials of a structure. In this review, eight types of powders of raw materials F1 to F8 shown in FIG. 2 were used. These raw materials are powders of yttrium oxyfluoride, and include at least one of YOF and YOF (for example, Y ₅ O ₄ F ₇ , Y ₇ O ₆ F _9, etc.) of 1: 1: 1. In addition, each raw material does not substantially contain YF ₃ and Y ₂ O ₃ .

In addition, the fact that YF ₃ is not substantially included means that in X-ray diffraction, the peak intensity of YF ₃ due to a diffraction angle of 2θ = 24.3 ° or around 25.7 ° is not fully due to a diffraction angle of 2θ = 13.8 ° or 1% of the peak intensity of YOF near 36.1 °. Or the fact that YF ₃ is not substantially included means that in X-ray diffraction, the peak intensity of YF ₃ caused by the diffraction angle around 2θ = 24.3 ° or around 25.7 ° is not fully caused by the diffraction angle around 2θ = 32.8 ° 1: 1% of the intensity of the spikes of 1: 2 YOF. The vicinity of 2θ = 24.3 ° means, for example, about 24.3 ± 0.4 ° (23.9 ° or more and 24.7 ° or less). The vicinity of 2θ = 25.7 ° means, for example, about 25.7 ± 0.4 ° (25.3 ° or more and 26.1 ° or less). The vicinity of 2θ = 32.8 ° means, for example, about 32.8 ° ± 0.4 ° (32.4 ° or more and 33.2 ° or less). In addition, the fact that Y ₂ O ₃ is not substantially included means that the peak intensity of Y ₂ O ₃ due to the vicinity of the diffraction angle 2θ = 29.1 ° in X-ray diffraction is less than the cause of the diffraction angle 2θ = 13.8 ° or 36.1 °. The peak intensity of the nearby YOF is 1%. Or the fact that Y ₂ O ₃ is not substantially included means that in X-ray diffraction, the peak intensity of Y ₂ O ₃ caused by the vicinity of the diffraction angle 2θ = 29.1 ° is not fully caused by the vicinity of the diffraction angle 2θ = 32.8 °: 1% of the intensity of the spikes of 1: 2 YOF.

The raw materials F1 to F8 are different from each other in the median size (D50 (μm)) shown in FIG. 2. In addition, the median particle diameter is a diameter of 50% in a cumulative distribution of the particle diameters of the respective raw materials. As the diameter of each particle, a diameter obtained by a circular approximation can be used. Samples of a plurality of structures (layered structures) were produced by changing the combination of these raw materials and film forming conditions (the type and flow rate of the carrier gas), and the plasma resistance was evaluated. In addition, in this example, an aerosol deposition method was used for the preparation of the samples.

FIG. 3 is a table illustrating a sample of a structure. As shown in FIG. 3, the carrier gas may be nitrogen (N ₂ ) or helium (He). An aerosol can be obtained by mixing a carrier gas and a raw material powder (raw material fine particles) in an aerosol generator. The obtained aerosol is sprayed from a nozzle connected to the aerosol generator toward a substrate disposed inside the film-forming reaction chamber by a pressure difference. At this time, the air in the film-forming reaction chamber is exhausted to the outside by a vacuum pump. In the case of nitrogen, the flow rate of the carrier gas is 5 (L / min: L / min) to 10 (L / min). In the case of helium, the flow rate of the carrier gas is 3 (L / min) to 5 (L / min). .

Each of the structures of samples 1 to 10 mainly contains polycrystals of yttrium oxyfluoride, and the average crystallite size in the polycrystals is less than 100 nm.

The crystallite size was measured using X-ray diffraction. [X'PertPRO / PANalytical] was used as the XRD device. Use tube voltage 45kV, tube current 40mA, Step Size 0.033 °, Time per Step 336 seconds or more. The crystallite size was calculated by the above-mentioned Xie Le formula as the average crystallite size. Use 0.94 as the K value in the Xie Le formula.

The main component of the crystal phase of yttrium oxyfluoride is measured using X-ray diffraction. [X'PertPRO / PANalytical] was used as the XRD device. Use X-ray Cu-Kα (wavelength 1.5418Å), tube voltage 45kV, tube current 40mA, Step Size 0.033 °, Time per Step 100 seconds or more. The calculation of the principal component was performed using XRD analysis software [High Score Plus / PANalytical]. Using the ICDD (International Centre for Diffraction Data) card's quasi-quantitative value (RIR = Reference Intensity Ratio), the peak search is performed on the diffraction peak. The relative intensity ratio obtained at time is calculated. In addition, in the case of a laminated structure, the measurement results of the main component of yttrium oxyfluoride are preferably obtained by using thin film XRD from the outermost surface to a depth of less than 1 μm.

The crystal structure of yttrium oxyfluoride was evaluated using X-ray diffraction. [X'PertPRO / PANalytical] was used as the XRD device. X-ray Cu-Kα (wavelength 1.5418 Å), tube voltage 45 kV, tube current 40 mA, and step size 0.033 ° were used. In addition, in order to improve the measurement accuracy, Time per Step is preferably 700 seconds or more.

The ratio of the peak intensity of the rhombohedral crystal in yttrium oxyfluoride to γ1 uses the peak intensity (r1) of the rhombohedral crystal of yttrium oxyfluoride due to the diffraction angle around 2θ = 13.8 ° and the The peak intensity (r2) of the rhombohedral crystal of yttrium oxyfluoride in the vicinity of the shot angle 2θ = 36.1 ° was calculated from r2 / r1 × 100 (%).

The ratio γ2 of the orthorhombic to rhombohedral crystals in the oxyfluoride of yttrium was measured using X-ray diffraction as described above. [X'PertPRO / PANalytical] was used as the XRD device. X-ray Cu-Kα (wavelength 1.5418 Å), tube voltage 45 kV, tube current 40 mA, and step size 0.033 ° were used. In addition, in order to improve the measurement accuracy, Time per Step is preferably 700 seconds or more.

The ratio of the orthorhombic to rhombohedral crystal γ2 uses the peak intensity (r1) of the specular surface (003) of the rhombohedral crystal containing YOF and the like that is near the diffraction angle 2θ = 13.8 ° and the diffraction angle 2θ = The peak intensity (о) of the mirror surface (100) of the orthorhombic crystal including Y ₇ O ₆ F ₉ or Y ₅ O ₄ F ₇ near 16.1 °. The peak intensity (о) of the orthorhombic crystal / rhombohedron The peak intensity (r1) x 100 (%) of the crystal was calculated.

4 (a), 4 (b), and 5 are graphs showing X-ray diffraction in a sample of a structure. In each of FIGS. 4 (a), 4 (b), and 5, the horizontal axis represents the diffraction angle 2θ, and the vertical axis represents the intensity. As shown in Fig. 4 (a) and Fig. 5, samples 1 to 10 contain rhombohedral crystals of yttrium oxyfluoride (for example, polycrystalline YOF), and spikes were detected around the diffraction angle 2θ = 13.8 ° in each sample. Pr1. Further, as shown in FIG. 4 (b), a peak Pr2 was detected in the vicinity of the diffraction angle 2θ = 36.1 ° in each of the samples 3, 4, and 6 to 10. In samples 1 and 2, no peak was detected near the diffraction angle 2θ = 36.1 °.

As shown in FIGS. 4 (a) and 5, samples 3 to 7 contain orthorhombic yttrium oxyfluoride (for example, at least one of Y ₅ O ₄ F ₇ or Y ₇ O ₆ F ₉ polycrystalline). A peak Po was detected near the diffraction angle 2θ = 16.1 °. In samples 1, 2, 8 to 10, no peak was detected near the diffraction angle 2θ = 16.1 °.

For each sample, the intensity of the background (r1 and r2) was calculated by excluding the intensity of the background from the data shown in FIGS. 4 (a) and 4 (b), and the ratio γ1 of the peak intensity of the rhombohedral crystal was obtained. For each sample, the intensity of the background (r1 and о) was calculated by excluding the intensity of the background from the data shown in FIG. 5 to obtain the ratio γ2 of the orthorhombic crystal to the rhombohedral crystal. The obtained ratios γ1 and γ2 are shown in FIG. 3.

As shown in FIG. 3, the ratio γ1 greatly changes by the combination of the raw material and the film formation conditions. The present inventors have obtained new knowledge that there is a correlation between the orientation of yttrium oxyfluoride of rhombohedral crystals and the plasma resistance. Furthermore, the ratio γ2 greatly changes depending on the combination of the raw material and the film forming conditions. The inventors of the present case have discovered for the first time that the ratio of the compounds in the structure is changed by film formation conditions and the like. For example, in raw material powders with a large oxygen content, such as raw materials F1 to F5, the ratio γ2 of the orthorhombic crystal to the rhombohedral crystal is 50% or more and 100% or less. On the other hand, by film formation by an aerosol deposition method, the ratio γ2 becomes 0% in samples 1 and 2, and exceeds 100% in sample 7. In addition, in all of the samples 1 to 10, no intensity peak was detected near the diffraction angle 2θ = 29.1 °. That is, if the intensity of the background is removed, the ratio of the peak intensity ε to the peak intensity r1 (ε / r1) is 0%, and samples 1 to 10 do not include Y ₂ O ₃ .

In addition, the plasma resistance of these samples 1 to 7 was evaluated. The plasma resistance of yttrium oxyfluoride was evaluated using a plasma etching apparatus and a surface profile measuring instrument. [Muc-21 Rv-Aps-Se / made by Sumitomo Precision Industry] was used for the plasma etching apparatus. The conditions for plasma etching are as follows: ICP (Inductively Coupled Plasma) output power is 1500W as power output, bias output power is 750W, and a mixed gas of CHF ₃ 100ccm and O ₂ 10ccm is used as Process gas (process gas), pressure is 0.5Pa, plasma etching time is 1 hour.

As the surface roughness measuring instrument, [SURFCOM 1500DX / Tokyo Precision] was used. As the index of the surface roughness, an arithmetic average roughness Ra was used. The cut off and evaluation length in the measurement of the arithmetic mean roughness Ra are standard values of the arithmetic mean roughness Ra suitable for the measurement results in accordance with JIS B0601.

Using the surface roughness Ra ₀ before the plasma etching of the sample and the surface roughness Ra ₁ after the plasma etching of the sample, the plasma resistance was evaluated by the amount of surface roughness change (Ra ₁ -Ra ₀ ).

The evaluation results of the plasma resistance are shown in FIG. 3. [〇] shows higher plasma resistance than a sintered body of yttrium oxide. [◎] indicates that the plasma resistance is higher than [0], and is equal to or more than the plasma resistance of the yttrium oxide structure produced by the aerosol deposition method. [△] indicates that the plasma resistance is lower than that of [0] and is equivalent to that of a sintered body of yttrium oxide. [×] indicates that the plasma resistance is lower than [△].

As shown in FIG. 3, the inventors of the present case found that the plasma resistance was related to the ratio γ1. That is, in samples 6 and 7 in which the ratio γ1 was 100% or more, the plasma resistance was low. By controlling the ratio γ1 to less than 100% by film forming conditions, etc., the plasma resistance can be improved, and practically sufficient plasma resistance can be obtained.

By making the ratio γ1 less than 80%, as in samples 3, 4, 9, and 10, the plasma resistance can be made higher than that of the sintered body of yttrium oxide. By setting the ratio γ1 to 0%, the plasma resistance can be improved to be equal to or more than that of the yttrium oxide structure produced by the aerosol deposition method as in samples 1, 2, and 8.

Furthermore, as shown in FIG. 3, the inventors of the present case found that the plasma resistance was related to the ratio γ2. That is, in Sample 7 in which the ratio γ2 was 106% or more, the plasma resistance was low. In the structure 20 according to the embodiment, the ratio γ2 is controlled to less than 100% by adjusting the film formation conditions and the like, thereby improving the plasma resistance and obtaining practically sufficient plasma resistance.

By setting the ratio γ2 to 85% or less, and preferably 70% or less, the plasma resistance can be improved to the same level as the sintered body of yttrium oxide as in samples 5 and 6. By setting the ratio γ2 to 30% or less, the plasma resistance can be improved to the same level as the structure of yttrium oxide formed by the aerosol deposition method as in samples 3 and 4. By setting the ratio γ2 to 0%, the plasma resistance can be further improved like the samples 1 and 2.

It is known that when an aerosol deposition method is used to form a structure of an oxide such as Al ₂ O ₃ or Y ₂ O ₃ , the structure has no crystal orientation. On the other hand, since YF ₃ or yttrium oxyfluoride has cleavage, for example, particles of the raw material are easily broken along the cleavage plane due to the application of mechanical shock. Therefore, it is considered that the fine particles are broken along the cleavage surface during film formation due to a mechanical impact force, and the structure is aligned in a specific crystal direction.

Further, when the raw material has cleavage, if the structure is damaged by plasma irradiation, a crack may be generated along the cleavage plane, and particles may be generated from the crack as a starting point. Therefore, when the structure is formed, the fine particles are broken along the cleavage plane in advance, and the alignment is adjusted. Specifically, the ratios γ1 and γ2 are adjusted. Accordingly, it is considered that the plasma resistance can be improved.

The embodiment of the present invention has been described above. However, the present invention is not limited to these descriptions. Regarding the aforementioned embodiments, those skilled in the art may suitably add design changes as long as they have the features of the present invention and are included in the scope of the present invention. For example, the shape, size, material, and arrangement of a structure, a substrate, and the like are not limited to those illustrated, and may be appropriately changed. In addition, each element provided in each of the aforementioned embodiments can be technically combined as much as possible, and those who combine these elements are included in the scope of the present invention as long as they also include the features of the present invention.

10: Component 15: Base material 20, 20a: Structure 20c: Crystal 21, 22: Layer Po, Pr1, Pr2: Spike

FIG. 1 is a cross-sectional view illustrating a member having a structure according to an embodiment. FIG. 2 is a table illustrating raw materials of a structure. FIG. 3 is a table illustrating a sample of a structure. 4 (a) and 4 (b) are graphs showing X-ray diffraction in a sample of a structure. FIG. 5 is a graph showing X-ray diffraction in a sample of a structure. 6 is a cross-sectional view illustrating a member having another structure according to the embodiment. FIG. 7 is a photographic view illustrating a structure according to the embodiment.

Claims (19)

A structure mainly composed of a polycrystal of yttrium oxyfluoride having a crystal structure of rhombohedral crystals, and the average crystallite size in the polycrystal is less than 100 nm, and is diffracted at a diffraction angle by X-ray The peak intensity of the rhombohedral crystal detected near 2θ = 13.8 ° is r1, the peak intensity of the rhombohedral crystal detected near the diffraction angle 2θ = 36.1 ° is r2, and the ratio γ1 is γ1 (%) = r2 / For r1 × 100, the ratio γ1 is 0% or more and less than 100%. For example, the structure in the first scope of the patent application, wherein the ratio γ1 is less than 80%. For example, if the structure of item 1 or item 2 of the patent application scope does not include yttrium oxyfluoride with a crystal structure of orthorhombic crystals, or further includes yttrium oxyfluoride with a crystal structure of orthorhombic crystals, The peak intensity of the orthorhombic crystal detected by X-ray diffraction around the diffraction angle 2θ = 16.1 ° is о, and the ratio of the orthorhombic to rhombohedral crystal is γ2 (%) = о / r1 × 100, The ratio γ2 is 0% or more and less than 100%. For example, if the structure of the first or second aspect of the patent application is applied, the yttrium oxyfluoride having a crystal structure of rhombohedral crystal is YOF. For example, the structure in the third item of the patent application, wherein the yttrium oxyfluoride having an orthorhombic crystal structure is a YOF of 1: 1.2. For example, for the structure in the third scope of the patent application, the ratio γ2 is 85% or less. For the structure in the third item of the patent application, the ratio γ2 is 70% or less. For the structure in the third scope of the patent application, the ratio γ2 is 30% or less. For example, the structure of item 1 or item 2 of the patent application scope, wherein the average crystallite size is less than 50 nm. For example, the structure of item 1 or item 2 of the patent application scope, wherein the average crystallite size is less than 30 nm. For example, the structure of the first or the second item of the patent application scope, wherein the average crystallite size is less than 20 nm. For example, if the structure of item 1 or item 2 of the patent application scope, in which the peak intensity detected by X-ray diffraction around the diffraction angle 2θ = 29.1 ° is ε, the ratio of ε to r1 and the ε At least one of the ratios to r2 is less than 1%. For example, if the structure of item 1 or item 2 of the patent application scope, in which the peak intensity detected by X-ray diffraction around the diffraction angle 2θ = 29.1 ° is ε, the ratio of ε to r1 and the ε At least one of the ratios to r2 is 0%. For example, the structure of claim 3, wherein the yttrium oxyfluoride having a crystal structure of rhombohedral crystal is YOF. For example, the structure in the scope of patent application No. 3, wherein the average crystallite size is less than 50 nm. For example, the structure in the scope of patent application No. 3, wherein the average crystallite size is less than 30 nm. For example, the structure of claim 3 in the patent application scope, wherein the average crystallite size is less than 20 nm. For example, the structure of the third item of the patent application, where the peak intensity detected by X-ray diffraction around the diffraction angle 2θ = 29.1 ° is ε, the ratio of ε to r1 and the ratio of ε to r2 At least one of the ratios is less than 1%. For example, the structure of the third item of the patent application, where the peak intensity detected by X-ray diffraction around the diffraction angle 2θ = 29.1 ° is ε, the ratio of ε to r1 and the ratio of ε to r2 At least one of the ratios is 0%.