KR20190120119A - Structure - Google Patents

Abstract

An object of the present invention is to provide a structure containing yttrium oxyfluoride and capable of increasing plasma resistance. The structure has a polycrystalline body of yttrium oxyfluoride having a rhombohedral crystal as a main component and an average crystallite size is less than 100 nanometers in the polycrystalline body, wherein if the peak intensity of the rhombohedral crystal detected near a diffraction angle 2θ=13.8° by X-ray diffraction is called r1, the peak intensity of the rhombohedral crystal detected near the diffraction angle 2θ = 36.1° is called r2, and a ratio γ1 is set to γ1(%) = r2 / r1×100, the structure which has 0% or more and less than 100% of the ratio is provided.

Description

Structure {STRUCTURE}

The form of this invention relates generally to a structure.

As a member used in a plasma irradiation environment, such as a semiconductor manufacturing apparatus, what formed the film with high plasma resistance on the surface is used. As the 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) is used.

On the other hand, in the oxide-based ceramics according to the fluoride by the reaction of a CF-based gas, the membrane by a volume expansion and the like cracks, as a result, by that connection to the generation of particles, originally it has been fluoride yttrium with fluoride (YF _3), etc. A proposal has been made to use fluoride-based ceramics (JP-A-2013-140950).

In YF ₃ , the resistance to F plasma is high, but the resistance to Cl plasma is insufficient, or the chemical stability of fluoride is questioned. Also, Japanese Patent Laid-Open No. 2014-009361 and Japanese Patent Laid-Open No. 2016-098143 have been proposed.

So far, YF ₃ and YOF have been studied in a thermal sprayed coating and a sintered body. However, in a thermal sprayed coating and a sintered compact, plasma resistance may be inadequate and it is calculated | required to further improve plasma resistance.

For example, forming a thermal sprayed coating using the oxyfluoride of a rare earth element as a raw material is examined (Japanese Patent No. 5927656). However, in the thermal spraying, oxidation occurs due to oxygen in the atmosphere during heating. Therefore, by the Y ₂ O ₃ incorporated into the sprayed coating obtained in some cases the control of the composition difficult. Moreover, the thermal spraying still has a problem in density. Further, in the plasma etching, the use of YF ₃ coating chamber by spraying, the etching rate is also problem that does not drift, and stability (U.S. Patent Application Publication No. 2015/0126036 specification). Further, Y ₂ after the formation of a film containing O _3, has also been reviewed by the fluoride method for annealing a film such as a plasma process (U.S. Patent Application Publication No. 2016/273095 specification). However, in this method, since the fluorination treatment is performed on the film containing Y ₂ O ₃ formed once, the volume of the film is changed by the fluorination, which may cause problems such as peeling from the substrate or cracking of the film. . Moreover, the control of the composition of the whole film may be difficult. In addition, in a thermal spraying or a sintered compact, F ₂ gas is released by thermal decomposition of fluoride raw material fine particles during heating, which poses a problem to safety.

On the other hand, Japanese Patent Laid-Open No. 2005-217351 discloses that a plasma resistant structure can be formed at room temperature by the aerosol deposition method for Y ₂ O ₃ . However, the aerosol deposition method using yttrium oxyfluoride has not been sufficiently studied.

The first invention is a structure in which a polycrystalline body of yttrium oxyfluoride having a crystal structure of a rhombohedral crystal is a main component, and the average crystallite size in the polycrystalline body is less than 100 nanometers, and the diffraction angle is 2θ = 13.8 by X-ray diffraction. The peak intensity of the rhombohedral crystal detected in the vicinity of ° 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 / r1 × 100. When it is set as above, the ratio γ1 is a structure that is 0% or more and less than 100%.

In the second invention, the ratio γ1 is a structure of less than 80%.

The inventors of the present invention have found that the predetermined peak intensity ratio (ratio γ1) of yttrium oxyfluoride of rhombohedral crystals is correlated with plasma resistance. When ratio (gamma) 1 is 100% or more, it turned out that plasma performance falls. By setting the ratio γ1 to 0% or more and less than 100%, preferably less than 80%, it becomes possible to express practically excellent plasma resistance.

The third invention is the first or second invention, wherein the structure does not include yttrium oxyfluoride having a tetragonal crystal structure, or further comprises yttrium oxyfluoride having a tetragonal crystal structure, and the diffraction angle 2θ = 16.1 When the peak intensity of the tetragonal crystal detected in the vicinity is o, and the ratio of the tetragonal crystal to the rhombohedral crystal is γ 2 (%) = o / r 1 × 100, the ratio γ 2 is a structure of 0% or more and less than 100%. .

The inventors have found a correlation between the ratio of the compound or crystal phase in the structure (ratio γ 2) and the plasma resistance. When ratio (gamma) 2 is 100% or more, it turned out that plasma resistance becomes low. Plasma resistance can be improved by making ratio (gamma) 2 into 0% or more and less than 100%.

In the fourth aspect of the invention, the yttrium oxyfluoride having the crystal structure of the rhombohedral crystal is YOF.

In a fifth aspect of the invention, the yttrium oxyfluoride having a tetragonal crystal structure is a YOF of 1: 1: 2.

According to these structures, plasma resistance can be improved.

6th invention is 3rd invention WHEREIN: The said ratio (gamma) 2 is a structure which is 85% or less.

7th invention is a structure which the said ratio (gamma) 2 is 70% or less in 3rd invention.

In 8th invention, in the 3rd invention, the said ratio (gamma) 2 is 30% or less of structure.

According to these structures, plasma resistance can be further improved.

The ninth invention is the structure of any one of the first to eighth aspects, wherein the average crystallite size is less than 50 nanometers.

The tenth invention is the structure of any one of the first to eighth aspects, wherein the average crystallite size is less than 30 nanometers.

In an eleventh invention, in the invention of any one of the first to eighth, the average crystallite size is a structure of less than 20 nanometers.

According to these structures, the particles generated from the structure by the plasma can be made small by the small average crystallite size.

12th invention is any one of 1st-11th invention WHEREIN: When the peak intensity detected by X-ray diffraction in the vicinity of diffraction angle 2 (theta) = 29.1 degrees is epsilon, the ratio of said epsilon with respect to said r1, And at least one of the ratios of ε to r2 is less than 1%.

According to this structure, since Y ₂ O ₃ contained in the structure is minute, fluorination by CF plasma can be suppressed, and the plasma resistance can be further improved.

13th invention is any one of the 1st-11th invention WHEREIN: When the peak intensity detected by X-ray diffraction in the vicinity of diffraction angle 2 (theta) = 29.1 degrees is epsilon, the ratio of said epsilon with respect to said r1, And at least one of the ratio of ε to the r2 is 0%.

According to this structure, since Y ₂ O ₃ is not substantially contained, fluorination by CF plasma is suppressed, and the plasma resistance can be further improved.

1 is a cross-sectional view illustrating a member having a structure according to an embodiment.
2 is a table illustrating raw materials of the structure.
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 the structure.
5 is a graph showing X-ray diffraction in a sample of the structure.
6 is a cross-sectional view illustrating a member having another structure according to the embodiment.
7 is a photograph illustrating a structure according to an embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same component, and detailed description is abbreviate | omitted suitably.

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 a composite structure which has the base material 15 and the structure 20, for example.

The member 10 is a member for a semiconductor manufacturing apparatus which has a chamber, for example, and is installed in a chamber. Since gas is introduced into the chamber to generate plasma, the member 10 is required to have plasma resistance. The member 10 (structure 20) may be used in addition to the inside of the chamber, and the semiconductor manufacturing apparatus includes any semiconductor manufacturing apparatus (semiconductor processing apparatus) that performs annealing, etching, sputtering, CVD, or the like. . In addition, the member 10 (structure 20) may be used for members other than a semiconductor manufacturing apparatus.

The base material 15 contains alumina, for example. However, the material of the base material 15 is not limited to ceramics such as alumina, and may be quartz, aluminite, metal, glass, or the like. In addition, in this example, the member 10 which has the base material 15 and the structure 20 is demonstrated. The form of only the structure 20 is also included in embodiment without installing the base material 15. FIG. In addition, 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 micrometers (µm), preferably less than 1 µm, More preferably, it is less than 0.5 micrometer.

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

In the present specification, the principal component of the structure refers to a compound that is included relatively more than other compounds included in the structure 20 by quantitative or quasi-quantitative analysis by X-ray diffraction (XRD) of the structure. . For example, the main component is the compound most contained in the structure, the proportion of the main component in the structure is greater than 50% by volume or mass ratio. The proportion occupied by the main component is more preferably greater than 70% and more preferably greater than 90%. The proportion of the main component may be 100%.

In addition, yttrium oxyfluoride is a compound of yttrium (Y), oxygen (O), and fluorine (F). As yttrium oxyfluoride, for example, YOF of 1: 1: 1 (molar ratio Y: O: F = 1: 1: 1), YOF of 1: 1: 2 (molar ratio Y: O: F = 1: 1 : 2). In addition, in this specification, the range of Y: O: F = 1: 1: 2 is not limited to the composition whose Y: O: F is exactly 1: 1: 2, The molar ratio of fluorine to yttrium (F / Y) may contain a composition larger than 1 and less than 3. For example, Y ₅ O ₄ F ₇ (molar ratio Y: O: F = 5: 4: 7), Y ₆ O ₅ F ₈ (molar ratio as y: O: F = 1: 1: 2 yttrium oxyfluoride) 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 (molar ratio Y: O: F = 17:14:23). In addition, in this specification, when it says only "YOF", it means Y: O: F = 1: 1: 1, and when it says "YOF of 1: 1: 1," Y: O: F mentioned above. = 1: 1: 2. Moreover, the composition of that excepting the above may be contained in the range called yttrium oxy fluoride.

In the example of FIG. 1, the structure 20 is a single layer structure, but the structure formed on the base material 15 may be a multilayer structure (refer FIG. 6). For example, a separate layer 22 (for example, a layer containing Y ₂ O ₃ ) is formed between the substrate 15 and the layer 21 corresponding to the structure 20 in FIG. 1. It may be. The layer 21 corresponding to the structure 20 forms the surface of the structure 20a of a multilayer structure.

The structure 20 is formed of a raw material containing, for example, yttrium oxyfluoride. This raw material is manufactured by, for example, fluorination of yttria. By this manufacturing process, a raw material is divided roughly into two types, a thing with large oxygen content and a thing with small oxygen content. The oxygen content of the raw material is large, for example, YOF, 1: 1: 2 of YOF _{(e.g., Y 5 O 4 F 7,} Y 7 O 6 F 9 , etc.) and a. The raw material with much oxygen content may contain only YOF. In addition, oxygen content of less raw material is, for example, _{Y 5 O 4 F 7, Y} 7 O 6 F 9 and the like include adding YF _3, YOF does not include. When sufficient fluorination treatment is carried out, the raw material may contain only YF ₃ and may not contain yttrium oxyfluoride. In this embodiment, the structure contains yttrium oxyfluoride of rhombohedral crystals. The fact that a raw material or a structure contains yttrium oxyfluoride of rhombohedral crystals means that a peak is detected in at least one of the vicinity of diffraction angle 2θ = 13.8 ° and the diffraction angle 2θ = 36.1 ° in X-ray diffraction.

In a structure used for a semiconductor manufacturing apparatus or the like, YF ₃ , Y ₅ O ₄ F ₇ , Y ₇ O ₆ F _9, etc. may be oxidized over time and changed to YOF. In addition, YOF has also been reported to have better corrosion resistance than other compositions (Japanese Patent Laid-Open No. 2016-098143).

The inventors of the present invention have found that, in a structure mainly composed of yttrium oxyfluoride, there is a correlation between the plasma resistance and the crystal structure of the structure, and the plasma resistance can be enhanced by controlling the crystal structure. Plasma resistance can be improved by controlling the crystal structure of yttrium oxyfluoride contained in the structure.

Specifically, the crystal structure of the structure 20 according to the embodiment is as follows.

The structure 20 includes polycrystals of yttrium oxyfluoride having a crystal structure of rhombohedral crystals. Further, in the X-ray diffraction of the structure 20, the ratio γ1 with respect to the peak intensity of the rhombohedral crystal is 0% or more and less than 100%, preferably less than 80%.

Here, the ratio γ1 is calculated by the following method.

X-ray diffraction is performed on the structure 20 containing yttrium oxyfluoride by θ-2θ scan. The peak intensity of the rhombohedral crystal detected near the diffraction angle 2θ = 13.8 ° by X-ray diffraction of the structure 20 is called r1. 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 called r2. At this time, γ 1 (%) = r 2 / r 1 × 100. For example, the ratio γ1 represents the degree of orientation of the yttrium oxyfluoride of the rhombohedral crystal.

The peaks near the diffraction angle 2θ = 13.8 ° and the peaks near the diffraction angle 2θ = 36.1 ° are considered to be due to the YOF of the rhombohedral crystal, for example.

In addition, near diffraction angle 2θ = 13.8 ° is, for example, about 13.8 ± 0.4 ° (13.4 ° or more and 14.2 ° or less), and diffraction angle 2θ = 36.1 ° is, for example, about 36.1 ° ± 0.4 ° (35.6 ° or more and 36.4). ° or less).

In addition, the structure 20 includes yttrium oxyfluoride having a crystal structure of rhombohedral crystals and no yttrium oxyfluoride having a tetragonal crystal structure.

Alternatively, the structure 20 includes yttrium oxyfluoride having a crystal structure of rhombohedral crystals and yttrium oxyfluoride having a crystal structure of rhombohedral crystals, and the ratio γ2 to rhombohedral crystals is 0% or more and less than 100%.

Here, the ratio γ 2 is calculated by the following method.

The structure 20 containing yttrium oxyfluoride is subjected to X-ray diffraction (XRD) by θ-2θ scan. The peak intensity of the rhombohedral crystal detected near the diffraction angle 2θ = 13.8 ° by X-ray diffraction is called r1. The peak intensity of the tetragonal crystal detected by the X-ray diffraction near the diffraction angle 2θ = 16.1 ° is called o. At this time, γ2 (%) = o / r1 × 100.

In addition, the peak near the diffraction angle 2θ = 16.1 ° is considered to be due to a YOF of 1: 1: 2 of the tetragonal crystal (for example, at least one of Y ₅ O ₄ F ₇ or Y ₇ O ₆ F ₉ of the tetragonal crystal). do.

In addition, near diffraction angle 2θ = 16.1 ° is, for example, about 16.1 ± 0.4 ° (15.7 ° or more and 16.5 ° or less).

The ratio γ2 of the rhombohedral 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 this specification, (gamma) 2 = 0% means that it is below the lower limit of detection in a measurement, and it is synonymous that it does not contain the yttrium oxy fluoride which has a tetragonal crystal structure substantially.

In the polycrystal of yttrium oxyfluoride included 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, most preferably less than 20 nm. The particle generated by plasma can be made small because the average crystallite size is small.

In addition, X-ray diffraction can be used for the determination of crystallite size.

As the average crystallite size, the crystallite size can be calculated by the following Scheller formula.

D = Kλ / (βcosθ)

Here, D is the crystallite size, β is the peak half width (rad), θ is the bracket angle (rad), and λ is the wavelength of the X-ray used for the measurement.

In Scherer's equation, β is calculated by β = (βobs-βstd). βobs is the half width of the X-ray diffraction peak of the measurement sample, and βstd is the half width of the X-ray diffraction peak of the standard sample. K is a sherler integer.

X-ray diffraction peaks that can be used for the calculation of crystallite size in yttrium oxyfluoride are, for example, peaks resulting from the mirror plane (006) near the diffraction angle 2θ = 28 °, and the mirror near the diffraction angle 2θ = 29 ° Peaks attributable to the plane 012, peaks attributable to the mirror plane 018 near the diffraction angle 2θ = 47 °, peaks attributable to the mirror plane 110 near the diffraction angle 2θ = 48 °, and the like.

Moreover, you may calculate crystallite size from images, such as TEM observation. For example, the average value of the crystallite's equivalent circular diameter can be used for the average crystallite size.

In addition, the spacing between adjacent crystallites is preferably 0 nm or more and less than 10 nm. The spacing between adjacent crystallites means the spacing closest to each other and does not include a gap composed of a plurality of crystallites. The spacing between crystallites can be obtained from an image obtained by observation using a transmission electron microscope (TEM). In addition, the TEM image which observed an example of the structure 20 by embodiment in FIG. 7 is shown. The structure 20 includes a plurality of crystallites 20c (crystal grains).

Also, for example, structure 20 is substantially free of Y ₂ O ₃ . When X-ray diffraction is performed on the structure 20 by θ-2θ scan, the peak intensity attributable to Y ₂ O ₃ detected near the diffraction angle 2θ = 29.1 ° is referred to as ε. At this time, at least 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 Y ₂ O ₃ contained in the structure 20 is minute, fluorination by the CF-based plasma can be suppressed, thereby further improving plasma resistance. In addition, near 2θ = 29.1 ° is, for example, about 29.1 ± 0.4 ° (28.7 ° or more and 29.5 ° or less).

The structure 20 which concerns on embodiment can be formed by arrange | positioning microparticles | fine-particles, such as a brittle material, for example on the surface of the base material 15, and giving a mechanical impact force to the said microparticles | fine-particles. Here, in the "mechanical impact force provision" method, for example, a high hardness brush or roller that rotates at high speed, a piston which moves up and down at high speed, or the like, or a compressive force due to the shock wave generated at the time of explosion is used, or Ultrasonic waves or a combination thereof.

Moreover, it is also preferable to form the structure 20 which concerns on embodiment by the aerosol deposition method, for example.

The "aerosol deposition method" injects "aerosol" which disperse | distributed microparticles | fine-particles containing a brittle material, etc. in gas from a nozzle toward a base material, collides microparticles with base materials, such as a metal, glass, ceramics, and plastics, and this collision It is a method of forming a structure (for example, a layered structure or a film | membrane structure) containing the constituent material of microparticles | fine-particles on a base material by making a deformation | transformation or crushing into brittle material microparticles | fine-particles by the impact of the above. According to this method, a structure can be formed at normal temperature without requiring heating means, cooling means, or the like, and a structure having a mechanical strength equal to or higher than that of the sintered body can be obtained. In addition, it is possible to vary the density, mechanical strength, electrical properties, etc. of the structure by controlling the conditions for causing the fine particles to collide, the shape, the composition, and the like of the fine particles.

In addition, in this specification, a "polycrystal" means the structure which a crystal grain joins and aggregates. The diameter of crystal grains is 5 nanometers (nm) or more, for example.

In addition, in this specification, when a primary particle is a dense particle | grain, it means that the average particle diameter identified by particle size distribution measurement, a scanning electron microscope, etc. is 5 micrometers (micrometer) or less. In the case where the primary particles are porous particles which are easily broken by impact, the mean particle size is 50 µm or less.

In addition, in this specification, "aerosol" refers to the solid / gas mixed body which disperse | distributed the above-mentioned microparticles | fine-particles in gas (carrier gas), such as helium, nitrogen, argon, oxygen, dry air, and mixed gas containing these, and some Although "agglomerate" may be included, it is the state in which microparticles | fine-particles are disperse | distributed independently. The gas pressure and temperature of the aerosol are arbitrary, but the concentration of the fine particles in the gas is in the range of 0.0003 mL / L to 5 mL / L at the time of injection from the discharge port when the gas pressure is converted into 1 atmosphere and the temperature is 20 degrees Celsius. It is preferable in the formation of a structure.

The process of aerosol deposition is usually carried out at room temperature and has one feature in that the structure can be formed at a temperature sufficiently lower than the melting point of the particulate material, i.e., several hundred degrees Celsius or less.

In addition, in this specification, "room temperature" is the temperature which is remarkably low with respect to the sintering temperature of ceramics, and means a room temperature environment of 0-100 degreeC substantially.

In the present specification, the "powder" refers to a state in which the fine particles described above naturally aggregate.

Hereinafter, the examination by the inventors of the present application will be described.

2 is a table illustrating raw materials of the structure.

In this study, eight kinds of powders of the raw materials F1 to F8 shown in Fig. 2 are used. These raw materials are powders of yttrium oxyfluoride, and include at least one of YOF and YOF of 1: 1: 2 (for example, Y ₅ O ₄ F ₇ , Y ₇ O ₆ F _9, and the like). In addition, each raw material substantially does not contain YF ₃ and Y ₂ O ₃ .

In addition, the fact that YF ₃ is not substantially included means that the peak intensity attributable to YF ₃ near the diffraction angle 2θ = 24.3 ° or 25.7 ° in the X-ray diffraction is near the diffraction angle 2θ = 13.8 ° or 36.1 °. It is said that it is less than 1% of the peak intensity resulting from YOF. Alternatively, the fact that YF ₃ is not substantially included means that the peak intensity attributable to YF ₃ near the diffraction angle 2θ = 24.3 ° or near 25.7 ° in the X-ray diffraction is 1: 1: around the diffraction angle 2θ = 32.8 °. It is said to be less than 1% of the peak intensity resulting from YOF of 2. In addition, near 2θ = 24.3 ° is, for example, about 24.3 ± 0.4 ° (23.9 ° or more and 24.7 ° or less). The vicinity of 2θ = 25.7 ° is, for example, about 25.7 ± 0.4 ° (from 25.3 ° to 26.1 °). 2θ = around 32.8 ° is, for example, about 32.8 ° ± 0.4 ° (32.4 ° or more and 33.2 ° or less).

The fact that Y ₂ O ₃ is not substantially included means that the peak intensity attributable to Y ₂ O ₃ near the diffraction angle 2θ = 29.1 ° in the X-ray diffraction is near the diffraction angle 2θ = 13.8 ° or near 36.1 °. It is said that it is less than 1% of the peak intensity resulting from YOF. Or, Y ₂ it does not include the O ₃ substantially, the X-ray diffraction peak intensity due to the diffraction angle 2θ = 29.1 ° the vicinity of the Y ₂ O _3, the diffraction angle 2θ = 32.8 ° 1 in the vicinity of 1: It is said to be less than 1% of the peak intensity resulting from YOF of 2.

The raw materials F1 to F8 differ from each other in particle size as in the median diameter (D50 (µm)) shown in FIG. In addition, the median diameter is 50% of the diameter in the cumulative distribution of the particle diameter of each raw material. The diameter of each particle is the diameter obtained by circular approximation.

The combination of these raw materials and film forming conditions (type of carrier gas and flow rate) was changed to produce a sample of a plurality of structures (layered structures), and the plasma resistance was evaluated. In this example, the aerosol deposition method is used to prepare the sample.

3 is a table illustrating a sample of a structure.

As shown in FIG. 3, nitrogen (N ₂ ) or helium (He) is used for the carrier gas. An aerosol is obtained by mixing a carrier gas and raw material powder (raw material fine particles) in an aerosol generator. The obtained aerosol is injected toward the substrate disposed inside the film forming chamber from the nozzle connected to the aerosol generator by the pressure difference. At this time, the air in the film forming chamber is exhausted to the outside by the vacuum pump. The flow rate of the carrier gas is 5 (liters / minute: L / min) to 10 (L / min) for nitrogen, and 3 (L / min) to 5 (L / min) for helium.

Each of the structures of Samples 1 to 10 mainly contained polycrystals of yttrium oxyfluoride, and the average crystallite size in the polycrystals was less than 100 nm.

In addition, X-ray diffraction was used for the measurement of crystallite size.

As the XRD apparatus, "X'PertPRO / Panarical Chemical" was used. A tube voltage of 45 kV, a tube current of 40 mA, a Step Size of 0.033 ° and a Time per Step of 336 seconds or more were used.

As an average crystallite size, the crystallite size by the above-mentioned Scherler's formula was computed. 0.94 was used as the value of K in Scherer's formula.

X-ray diffraction was used for the measurement of the principal component of the yttrium oxyfluoride crystal phase. As the XRD apparatus, "X'PertPRO / Panarical Chemical" was used. X-ray Cu-Kα (wavelength: 1.5418 kW), tube voltage 45 kV, tube current 40 mA, Step Size 0.033 °, Time per Step 100 seconds or more were used. The analysis software "High Score Plus / panaritical made" of XRD was used for calculation of a principal component. Using the quasi-quantitative value (RIR = Reference Intensity Ratio) of ICDD card base material, it calculated by the relative intensity ratio calculated | required when performing peak search with respect to a diffraction peak. In addition, in the measurement of the main component of the yttrium oxyfluoride in the case of a laminated structure, it is preferable to use the measurement result of the depth area of less than 1 micrometer from the outermost surface by thin film XRD.

In addition, the crystal structure of yttrium oxyfluoride was evaluated using X-ray diffraction. As the XRD apparatus, "X'PertPRO / Panarical Chemical" was used. X-ray Cu-Kα (wavelength: 1.5418 kW), tube voltage 45 kV, tube current 40 mA, and Step Size 0.033 ° were used. Moreover, it is preferable to set it as Time per Step 700 second or more in order to improve measurement precision.

The ratio γ1 of the yttrium oxyfluoride to the peak intensity of the rhombohedral crystal is the peak intensity (r1) attributable to the rhombohedral crystal of the yttrium oxyfluoride around the diffraction angle 2θ = 13.8 ° and the diffraction angle 2θ = 36.1 ° It is computed by r2 / r1 * 100 (%) using the peak intensity (r2) resulting from the rhombohedral crystal of the yttrium oxyfluoride of the vicinity.

X-ray diffraction was used for the measurement of the ratio (gamma) 2 of a tetragonal crystal with respect to a rhombohedral crystal in yttrium oxyfluoride as mentioned above. As the XRD apparatus, "X'PertPRO / Panarical Chemical" was used. X-ray Cu-Kα (wavelength: 1.5418 kW), tube voltage 45 kV, tube current 40 mA, and Step Size 0.033 ° were used. Moreover, it is preferable to set it as Time per Step 700 second or more in order to improve measurement precision.

The ratio γ2 of the tetragonal crystal to the rhombohedral crystal is the peak intensity r1 attributable to the mirror surface of the rhombohedral crystal including YOF and the like near the diffraction angle 2θ = 13.8 °, and the Y near the diffraction angle 2θ = 16.1 °. _The peak intensity (o) of the tetragonal crystals / the peak intensity of the rhombohedral crystal (r1) using the peak intensity (o) attributable to the mirror surface 100 of the tetragonal crystal including 7O ₆ F ₉ , Y ₅ O ₄ F ₇ , and the like It is calculated by x 100 (%).

4 (a), 4 (b) and 5 are graphs showing X-ray diffraction in a sample of the structure.

In each of Figs. 4A, 4B, and 5, the horizontal axis represents diffraction angle 2θ, and the vertical axis represents intensity. As shown in Fig. 4 (a) and Fig. 5, samples 1 to 10 contain yttrium oxyfluoride (for example, YOF polycrystals) of rhombohedral crystals, and have peaks near the diffraction angle 2θ = 13.8 ° in each sample. Pr1 is detected. As shown in Fig. 4B, the peak Pr2 is detected in the vicinity of diffraction angle 2θ = 36.1 ° in each of Samples 3, 4 and 6 to 10. In samples 1 and 2, no peak is detected near the diffraction angle 2θ = 36.1 °.

4 (a) and 5, samples 3 to 7 are yttrium oxyfluorides having tetragonal crystals (for example, polycrystals of at least one of Y ₅ O ₄ F ₇ or Y ₇ O ₆ F ₉ ). And a peak Po is detected near the diffraction angle 2θ = 16.1 °. In samples 1, 2 and 8 to 10, no peak is detected near the diffraction angle 2θ = 16.1 °.

With respect to each sample, in the data shown in Figs. 4A and 4B, the above-described peak intensities r1 and r2 are calculated except for the background intensity, and the ratio γ1 for the peak intensity of the rhombohedral crystal is calculated. Is saved. In addition, in the data shown in FIG. 5 for each sample, the above-mentioned peak intensities r1 and o are calculated except for the background intensity, and the ratio γ2 of the tetragonal crystal with respect to the rhombohedral crystal is obtained. The obtained ratio γ1 and the ratio γ2 are shown in FIG. 3.

As shown in FIG. 3, ratio (gamma) 1 is largely changed by the combination of a raw material and film-forming conditions. The present inventors have gained new knowledge that there is a relationship between the orientation of the rhombohedral yttrium oxyfluoride and the plasma resistance.

In addition, the ratio γ 2 is also greatly changed by the combination of the raw material and the film forming conditions. The present inventors have found for the first time that the ratio of the compound in a structure changes by the film-forming conditions etc. in this way. For example, in raw material powders with high oxygen content such as raw materials F1 to F5, the ratio γ2 of the tetragonal crystal to the rhombohedral crystal is 50% or more and 100% or less. On the other hand, by the film forming by the aerosol deposition method, ratio (gamma) 2 becomes 0% in the samples 1 and 2, and exceeds 100% in the sample 7.

In addition, in all samples 1-10, the peak of intensity was not detected in the vicinity of diffraction angle 2 (theta) = 29.1 degrees. That is, except for the background intensity, the ratio (? / R1) of the peak intensity? To the peak intensity r1 was 0%, and Samples 1 to 10 did not contain Y ₂ O ₃ .

In addition, the plasma resistance was evaluated about these samples 1-7.

The plasma etching apparatus and the surface shape measuring instrument were used for evaluation of the plasma resistance of the yttrium oxyfluoride.

"Muc-21 Rv-Aps-Se / Sumitomo Seimitsu Kogyo Co., Ltd." was used for the plasma etching apparatus. Plasma etching conditions were 1500 W for the ICP output, 750 W for the bias output, and a mixed gas of CHF ₃ 100 ccm and O ₂ 10 ccm, the pressure was 0.5 Pa, and the plasma etching time was 1 hour as the power supply output.

"Surcomm 1500DX / Tokyo Seimitsu Corporation" was used for the surface roughness measuring instrument. Arithmetic mean roughness Ra was used as an index of surface roughness. The standard value suitable for the arithmetic mean roughness Ra of a measurement result was used for Cut Off and evaluation length in the measurement of arithmetic mean roughness Ra based on JISB0601.

Plasma resistance was evaluated by the surface roughness variation Ra ₁ -Ra ₀ 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 evaluation result of plasma resistance is shown in FIG. "(Circle)" shows higher plasma resistance than the sintered compact of yttria. "(Circle)" has higher plasma resistance than "(circle)" and shows that it is plasma resistance more than or equal to the yttria structure produced by the aerosol deposition method. "(Triangle | delta)" shows lower plasma resistance than "(circle)" and is about plasma resistance equivalent to the sintered compact of yttria. "X" shows that plasma resistance is lower than "(triangle | delta)".

As shown in FIG. 3, the inventors of the present application found that the plasma resistance and the ratio γ1 were correlated. That is, the plasma resistance is low in the samples 6 and 7 whose ratio (gamma) 1 is 100% or more. By controlling the ratio γ1 to less than 100% by the film forming conditions or the like, the plasma resistance can be improved, and sufficient plasma resistance can be obtained practically.

By setting the ratio γ1 to less than 80%, the plasma resistance can be made higher than that of the yttria sintered body as in Samples 3, 4, 9 and 10.

By setting the ratio γ1 to 0%, the plasma resistance can be increased to the equivalent or higher than that of the yttria structure produced by the aerosol deposition method as in Samples 1, 2 and 8.

Moreover, the inventors of the present application found that there is a correlation between the plasma resistance and the ratio γ2. That is, the plasma resistance is low in the sample 7 whose ratio (gamma) 2 is 106% or more. In the structure 20 which concerns on embodiment, plasma resistance can be improved by controlling ratio (gamma) 2 to less than 100% by adjusting film-forming conditions etc., and practically sufficient plasma resistance can be obtained.

By setting the ratio γ2 to 85% or less, preferably 70% or less, the plasma resistance can be increased to the equivalent of the sintered body of yttria as in Samples 5 and 6.

By setting the ratio γ2 to 30% or less, the plasma resistance can be increased to the equivalent of the structure of yttria 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 as in Samples 1 and 2.

In general, when an oxide structure such as Al ₂ O ₃ or Y ₂ O ₃ is formed using the aerosol deposition method, it is known that the structure has no crystal orientation.

On the other hand, since YF ₃ , yttrium oxyfluoride, and the like have cleavage properties, for example, the fine particles of the raw material tend to crack along the cleaved surface by applying a mechanical impact. Therefore, microparticles | fine-particles crack along a cleavage surface at the time of film forming by mechanical impact force, and it is thought that a structure is oriented in a specific crystal direction.

In addition, when the raw material has cleavage, if the structure is damaged by plasma irradiation, cracks are generated along the cleavage surface, and particles may be generated from this. Therefore, the fine particles are crushed along the cleaved surface in advance when the structure is formed to adjust the orientation. Specifically, the ratios γ1 and γ2 are adjusted. It is thought that this can improve plasma resistance.

In the above, embodiment of this invention was described. However, the present invention is not limited to these techniques. Regarding the above-described embodiments, design changes made by those skilled in the art as appropriate are included in the scope of the present invention as long as the features of the present invention are provided. For example, shapes, dimensions, materials, arrangements, and the like of structures, substrates, and the like are not limited to the examples, but may be appropriately changed.

In addition, each element with which each embodiment mentioned above can be combined as far as technically possible, and combining these elements is also included in the scope of the present invention as long as it contains the characteristics of this invention.

Claims (13)

A structure having a polycrystal of yttrium oxyfluoride having a crystal structure of a rhombohedral crystal as a main component, and having an average crystallite size of the polycrystal less than 100 nanometers,
The peak intensity of the rhombohedral crystal detected by the X-ray diffraction near the diffraction angle 2θ = 13.8 ° is r1, and the peak intensity of the rhombohedral crystal detected near the diffraction angle 2θ = 36.1 ° is called r2, and the ratio γ1 is determined. When γ1 (%) = r2 / r1 × 100, the ratio γ1 is 0% or more and less than 100%. The method of claim 1,
The ratio γ1 is less than 80%. The method of claim 1,
The structure is,
Does not contain yttrium oxyfluoride having a tetragonal crystal structure, or
Further comprising yttrium oxyfluoride having a tetragonal crystal structure, the peak intensity of the tetragonal crystal detected by the X-ray diffraction near the diffraction angle 2θ = 16.1 ° is referred to as o, and the ratio of the tetragonal crystal to the rhombohedral crystal is γ2 ( %) = o / r1 * 100, The said structure (gamma) 2 is 0% or more and less than 100% of structures. The method according to any one of claims 1 to 3,
The yttrium oxyfluoride having a rhombohedral crystal structure is YOF. The method of claim 3, wherein
The yttrium oxyfluoride having a tetragonal crystal structure is a YOF of 1: 1: 2. The method of claim 3, wherein
The ratio γ 2 is 85% or less. The method of claim 3, wherein
The ratio γ 2 is 70% or less. The method of claim 3, wherein
The ratio γ 2 is less than 30%. The method according to any one of claims 1 to 3,
Wherein said average crystallite size is less than 50 nanometers. The method according to any one of claims 1 to 3,
Wherein said average crystallite size is less than 30 nanometers. The method according to any one of claims 1 to 3,
Wherein said average crystallite size is less than 20 nanometers. The method according to any one of claims 1 to 3,
When the peak intensity detected by the X-ray diffraction near the diffraction angle 2θ = 29.1 ° is ε, at least one of the ratio of ε to r1 and the ratio of ε to r2 is less than 1%. structure. The method according to any one of claims 1 to 3,
When the peak intensity detected by the X-ray diffraction near the diffraction angle 2θ = 29.1 ° is ε, at least one of the ratio of ε to r1 and the ratio of ε to r2 is 0%. structure.

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