JP2016211070A - Material for spray coating, spray coating film, and member with spray coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material for spray coating capable of forming a spray coating film having improved plasma erosion resistance.SOLUTION: A material for spray coating contains an oxyhalogenated compound of a rare-earth element (RE-O-X) of 77 mass% or more, the compound containing the rare-earth element (RE), oxygen (O), and a halogen element (X) as constituent elements. The spray coating material does not substantially contain an oxide of the rare-earth element.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermal spray material, a thermal spray coating formed using the thermal spray material, and a member with a thermal spray coating.

  Techniques for imparting new functionality by coating the surface of a substrate with various materials have been used in various fields. As one of the surface coating techniques, for example, sprayed particles made of a material such as ceramics are sprayed on the surface of a base material as a softened or molten state by combustion or electric energy to form a sprayed coating made of such a material. Thermal spraying is known.

  In the field of manufacturing semiconductor devices and the like, generally, fine processing is performed on the surface of a semiconductor substrate by dry etching using plasma of a halogen-based gas such as fluorine, chlorine or bromine. Further, after dry etching, the inside of the chamber (vacuum container) from which the semiconductor substrate is taken out is cleaned using oxygen gas plasma. At this time, in the chamber, a member exposed to highly reactive oxygen gas plasma or halogen gas plasma may be corroded. When the corrosion (erosion) part falls off in the form of particles from the member, the particles can be attached to the semiconductor substrate and become a foreign substance (hereinafter, the foreign substance is referred to as a particle) that causes a defect in the circuit.

  Therefore, conventionally, in a semiconductor device manufacturing apparatus, for the purpose of reducing the generation of particles, a ceramic sprayed coating having plasma erosion resistance has been provided on a member exposed to plasma such as oxygen gas or halogen gas. It has been broken. For example, Patent Document 1 discloses that a sprayed coating having high corrosion resistance against plasma can be formed by using, as a thermal spraying material, granules containing at least a portion of yttrium oxyfluoride.

International Publication No. 2014/002580

However, with the improvement of the degree of integration of semiconductor devices, more precise management has been required for contamination by particles. Further, further improvement in plasma erosion resistance is required for ceramic spray coatings provided in semiconductor device manufacturing apparatuses.
In view of such circumstances, an object of the present invention is to provide a thermal spray material capable of forming a thermal spray coating having further improved plasma erosion resistance. Another object of the present invention is to provide a thermal spray coating formed by using this thermal spraying material and a member with a thermal spray coating.

In order to solve the above-described problems, the present invention provides a thermal spray material having the following characteristics. That is, the thermal spraying material disclosed herein includes a rare earth element oxyhalide (RE-O-X) containing rare earth elements (RE), oxygen (O) and halogen elements (X) as constituent elements. It is characterized by being contained in a proportion of not less than mass% and substantially free of the rare earth element oxide.
According to the study by the present inventors, the thermal spray material substantially free of rare earth element oxide and containing rare earth element oxyhalide (RE-OX) in the above range is, for example, thermal spraying composed of yttrium oxide. It has been found that a sprayed coating having superior plasma erosion resistance compared to the coating can be formed. As a result, a thermal spray material capable of forming a thermal spray coating with further improved plasma erosion resistance against halogen-based plasma is realized.

Note that Patent Document 1 discloses a thermal spray material containing a relatively high ratio of yttrium oxyfluoride (YOF) (see Examples 9 to 11). However, the content ratio of YOF calculated from the X-ray diffraction analysis results of these thermal spray materials and the oxygen content is 77% by mass or more of the whole, and does not contain yttrium oxide (Y ₂ O ₃ ). The material is not disclosed. That is, it can be said that the thermal spraying material disclosed here is a novel thermal spraying material capable of forming a thermal spraying coating having an unprecedented plasma erosion resistance.

In a preferred embodiment of the thermal spray material disclosed herein, the rare earth element fluoride is further contained in a proportion of 23% by mass or less. Furthermore, the rare earth element fluoride may be substantially not included.
The thermal spraying material disclosed here does not contain rare earth element oxides, so that the plasma erosion resistance of the thermal spray coating formed is improved as described above. Therefore, the rare earth element fluoride that can lower the plasma erosion resistance by being present in the sprayed coating can be allowed to contain up to the above ratio. And it is suitable for the thermal spray material that the plasma erosion resistance of the thermal spray coating to be formed can be further enhanced by being in a form that does not substantially contain a rare earth element fluoride.

In a preferred aspect of the thermal spray material disclosed herein, the rare earth element oxyhalide is characterized in that a molar ratio (X / RE) of the halogen element to the rare earth element is 1.1 or more. . The molar ratio of oxygen to the rare earth element (O / RE) is preferably 0.9 or less.
Increasing the proportion of the halogen element in the rare earth element oxyhalide in the thermal spraying material is preferable because the resistance to halogen-based plasma can be further enhanced. Further, it is preferable to reduce the ratio of oxygen in the rare earth element oxyhalide in the thermal spraying material because rare earth element oxides are hardly formed in the thermal spray coating. And it is preferable that these are adjusted in a well-balanced manner because a thermal spray coating having a low porosity and a high Vickers hardness can be obtained.

  In a preferred aspect of the thermal spray material disclosed herein, the rare earth element is yttrium, the halogen element is fluorine, and the rare earth element oxyhalide is yttrium oxyfluoride. With such a configuration, for example, a thermal spray material capable of forming a thermal spray coating excellent in erosion resistance against fluorine plasma is provided.

  In another aspect, the present invention provides a thermal spray coating that is a thermal spray material of the thermal spray material described above. Oxide components of rare earth elements in the thermal spray coating can embrittle the thermal spray coating and degrade plasma resistance. The thermal spray coating disclosed herein is formed by thermal spraying one of the above-mentioned thermal spray materials, and since the content of rare earth element oxide is reduced, it is resistant to plasma erosion. It is provided as an improvement in performance.

The thermal spray coating provided by the present invention is mainly composed of a rare earth element oxyhalide (RE-O-X) containing rare earth elements (RE), oxygen (O), and halogen elements (X) as constituent elements. Characterized by being substantially free of rare earth fluorides.
According to such a configuration, the sprayed coating is provided as having improved plasma erosion resistance with certainty because the content of the rare earth element fluoride is reduced.

  In a preferred embodiment of the thermal spray coating disclosed herein, the rare earth element oxide is substantially not contained. The rare earth element oxide is allowed to be contained when the rare earth element oxyhalide is the main component, but when it is not substantially contained, the plasma erosion resistance is preferably improved.

  In a preferred embodiment of the thermal spray coating disclosed herein, the rare earth element is yttrium, the halogen element is fluorine, and the rare earth element oxyhalide is yttrium oxyfluoride. With such a configuration, for example, a sprayed coating having excellent erosion resistance against fluorine plasma can be configured.

  Moreover, the member with a thermal spray coating provided by the technology disclosed herein is characterized in that the thermal spray coating according to any one of the above is provided on the surface of the base material. With this configuration, a film-coated member having excellent plasma erosion resistance is provided.

(A) No. 1 which is an embodiment. 8 and (b) no. It is a figure which shows the X-ray-diffraction spectrum acquired about the material for thermal spraying of 11.

  Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.

[Materials for thermal spraying]
The thermal spraying material disclosed here has (1) 77 mass of rare earth element oxyhalide (RE-O-X) containing rare earth element (RE), oxygen (O) and halogen element (X) as constituent elements. %, And (2) characterized by substantially not containing this rare earth element oxide.

  In the technology disclosed herein, the rare earth element (RE) is not particularly limited, and can be appropriately selected from scandium, yttrium, and lanthanoid elements. Specifically, scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), One or more of gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu) Combinations can be considered. Preferably, Y, La, Gd, Tb, Eu, Yb, Dy, Ce, etc. are mentioned from the viewpoints of improving plasma erosion resistance and cost. This rare earth element may contain any one of these alone or in combination of two or more.

  Further, the halogen element (X) is not particularly limited, and may be any element belonging to Group 17 of the periodic table. Specifically, any one of halogen elements such as fluorine (F), chlorine (Cl), bromine (Br), iodine (I) and astatine (At) may be used alone or in combination of two or more. Can do. Preferably, F, Cl and Br can be used. Typical examples of such rare earth element oxyhalides include oxyfluorides, oxychlorides and oxybromides of various rare earth elements.

The ratio of the rare earth element (RE), oxygen (O), and halogen element (X) constituting the rare earth element oxyhalide is not particularly limited.
For example, the molar ratio (X / RE) of the halogen element to the rare earth element is not particularly limited. As a preferred example, the molar ratio (X / RE) may be 1, for example, and is preferably larger than 1. Specifically, for example, it is more preferably 1.1 or more, for example, 1.2 or more, and further preferably 1.3 or more. The upper limit of the molar ratio (X / RE) is not particularly limited, and can be 3 or less, for example. Among these, the molar ratio (X / RE) of the halogen element to the rare earth element is more preferably 2 or less, and even more preferably 1.4 or less (less than 1.4). As a more preferable example of the molar ratio (X / RE), it is exemplified that the molar ratio (X / RE) is 1.3 or more and 1.39 or less (eg, 1.32 or more and 1.36 or less). Thus, a high ratio of the halogen element to the rare earth element is preferable because resistance to the halogen-based plasma is increased.

In addition, the molar ratio of oxygen element to rare earth element (O / RE) is not particularly limited. As a suitable example, the molar ratio (O / RE) may be 1, and is preferably smaller than 1. Specifically, for example, 0.9 or less is more preferable, for example, 0.88 or less, and further 0.86 or less is desirable. The lower limit of the molar ratio (O / RE) is not particularly limited, and can be, for example, 0.1 or more. Among them, as a more preferable example of the molar ratio of oxygen element to rare earth element (O / RE), it is preferably more than 0.8 and less than 0.85 (preferably 0.81 or more and 0.84 or less). . In this way, the ratio of oxygen element to the rare earth element is less preferred for the formation of oxides of rare earth elements in the thermal spray coating in the oxidation in the thermal spray (e.g., Y _{2 O 3)} is suppressed.

That is, rare earth element oxyhalides are represented by, for example, the general formula: RE ₁ O _m1 X _m2 (for example, 0.1 ≦ m1 ≦ 1.2, 0.1 ≦ m2 ≦ 3), and the like. And the ratio of X may be any compound. The rare earth element oxyhalide preferably has 0.81 <m1 <1, more preferably 0.81 <m1 <0.85, for example 0.82 ≦ m1 ≦ 0.84. Further, 1 <m2 <1.4 is preferable, and 1.29 <m2 <1.4, for example, 1.3 ≦ m2 ≦ 1.38.
As a preferred embodiment, the case where the rare earth element is yttrium (Y), the halogen element is fluorine (F), and the rare earth element oxyhalide is yttrium oxyfluoride (Y—O—F) will be described. Such yttrium oxyfluoride may be, for example, a compound that is thermodynamically stable and has a chemical composition of 1: 1: 1 in the ratio of yttrium, oxygen, and halogen as YOF. Further, thermodynamically relatively stable, the general _{formula; Y 5} (wherein, n, for example, satisfying 0.12 ≦ n ≦ 0.22.) Y 1 O 1-n F 1 + 2n represented by O ₄ F ₇ , Y ₆ O ₅ F ₈ , Y ₇ O ₆ F _9, Y ₁₇ O ₁₄ F _{23 and the} like may be used. In particular, Y ₆ O ₅ F ₈ , Y ₁₇ O ₁₄ F _{23 and the} like in which the molar ratios (O / RE) and (X / RE) are in the above-described preferable ranges are excellent in plasma erosion resistance and more precise. This is preferable because a sprayed coating having a high hardness can be formed.

In the above examples of yttrium oxyfluoride, since they can have the same or similar crystal structure, a part or all of yttrium (Y) is replaced with an arbitrary rare earth element, and part or all of fluorine (F). Can be replaced with any halogen element.
Such a rare earth element oxyhalide may be composed of any one of the above-mentioned single phases, or any of a mixed phase, a solid solution, a compound in which any two or more phases are combined, or these It may be configured by mixing or the like.

In addition, when the spray material contains rare earth element oxyhalides having a composition of plural (for example, a; when a natural number is a ≧ 2), the above molar ratio (X / RE) and molar ratio (O / For RE), the molar ratio (Xa / REa) and molar ratio (Oa / REa) are calculated for each composition, and the molar ratio (Xa / REa) and molar ratio (Oa / REa) By multiplying the respective abundance ratios and totaling them, the molar ratio (X / RE) and molar ratio (O / RE) of the entire rare earth element oxyhalide can be obtained.
The molar ratio (X / RE) and molar ratio (O / RE) for the above rare earth element oxyhalides should be calculated based on, for example, the composition of the rare earth element oxyhalide identified by X-ray diffraction analysis. Can do.

Specifically, the content ratio of the rare earth element oxyhalide contained in the thermal spraying material can be measured and calculated by the following method. First, the crystal structure of the substance contained in the thermal spray material is specified by X-ray diffraction analysis. At this time, the rare earth element oxyhalide is specified up to its valence (element ratio).
For example, in the case where one kind of rare earth element oxyhalide is present in the thermal spray material and the remaining is YF ₃ , the oxygen content of the thermal spray material is determined by, for example, an oxygen / nitrogen / hydrogen analyzer (for example, LECO Corporation). The content of rare earth element oxyhalides can be determined from the obtained oxygen concentration.
When two or more kinds of rare earth element oxyhalides are present or a compound containing oxygen such as yttrium oxide is mixed, the ratio of each compound can be quantified by a calibration curve method, for example. Specifically, several types of samples with different content ratios of each compound were prepared, X-ray diffraction analysis was performed on each sample, and a calibration curve showing the relationship between the main peak intensity and the content of each compound was created. To do. Then, based on the calibration curve, the content is quantified from the main peak intensity of the XRD rare earth element oxyhalide of the thermal spray material to be measured.

In the technology disclosed herein, the halogen-based plasma is typically plasma generated using a plasma generation gas containing a halogen-based gas (halogen compound gas). For example, specifically, a fluorine-based gas such as SF ₆ , CF ₄ , CHF ₃ , ClF ₃ , or HF, or chlorine such as Cl ₂ , BCl ₃ , or HCl, which is used in a dry etching process when manufacturing a semiconductor substrate. A typical example is plasma generated by using one kind of a bromine-based gas such as a system gas or HBr alone or by mixing two or more kinds. These gases may be used as a mixed gas with an inert gas such as argon (Ar).

The rare earth element oxyhalide is contained in the thermal spray material at a high rate of 77% by mass or more. Rare earth element oxyhalides are more excellent in plasma erosion resistance than yttria (Y ₂ O ₃ ), which is known as a material having high plasma erosion resistance. Such a rare earth element oxyhalide contributes to the improvement of the plasma erosion resistance even if it is contained in a small amount, but it is preferable because a very large amount of such a rare earth element oxyhalide can exhibit excellent plasma resistance. The ratio of the rare earth element oxyhalide is preferably 80% by mass or more (exceeding 80% by mass), more preferably 85% by mass or more (exceeding 85% by mass), and 90% by mass or more (90% by mass). % Excess), more preferably 95% by mass or more (95% excess). For example, substantially 100% by mass (all except inevitable impurities) is particularly preferable.

The thermal spray material disclosed herein is configured so as not to substantially contain the rare earth element oxide so that the high plasma resistance of the rare earth element oxyhalide can be expressed better.
The rare earth element oxide contained in the thermal spraying material can be present as it is in the thermal spray coating as a rare earth element oxide. For example, yttrium oxide contained in the thermal spraying material can exist as yttrium oxide as it is in the thermal spray coating by thermal spraying. This rare earth element oxide (for example, yttrium oxide) has lower plasma resistance than the rare earth element oxyhalide. For this reason, the portion containing the rare earth element oxide is liable to generate a brittle altered layer when exposed to a plasma environment, and the altered layer tends to be detached as fine particles. And there exists a possibility that this fine particle may accumulate on a semiconductor substrate as a particle. Therefore, the thermal spray material disclosed herein excludes the inclusion of rare earth element oxides that can serve as particle sources.

  In the present specification, “substantially free” means that the content ratio of the component (here, a rare earth element oxide such as yttrium oxide) is 5% by mass or less, preferably 3% by mass or less. It means that it is 1 mass% or less. Such a configuration can also be grasped, for example, when a diffraction peak based on the component is not detected when the thermal spray material is subjected to X-ray diffraction analysis.

Further, the thermal spray material disclosed herein is configured to suppress the content ratio of the fluoride of the rare earth element to 23% by mass or less. The rare earth element fluoride contained in the thermal spray material can be oxidized by thermal spraying to form an oxide of the rare earth element in the thermal spray coating. For example, yttrium fluoride contained in the thermal spray material can be oxidized by thermal spraying to form yttrium oxide in the thermal spray coating. Since such rare earth element oxides can serve as a particle source as described above, inclusion of more than 23% by mass is not preferable because plasma erosion resistance is reduced. From this point of view, the content of the rare earth element fluoride is preferably 20% by mass or less, more preferably 15% by mass or less, and further 10% by mass or less, for example, 5% by mass or less. Is preferred. In a more preferable embodiment of the thermal spray material disclosed herein, it may be substantially free of rare earth element fluorides (for example, yttrium fluoride).
In addition, the thermal spray material of this invention is allowed to contain the other substance which is hard to become a particle source by containing rare earth element oxyhalide in such a high ratio.

  The thermal spray material is typically provided in the form of a powder. Such a powder may be composed of granulated particles obtained by granulating finer primary particles, or a powder composed mainly of aggregates of primary particles (may include agglomerated form). There may be. From the viewpoint of thermal spraying efficiency, for example, the average particle diameter is not particularly limited as long as it is about 30 μm or less, and the lower limit of the average particle diameter is not particularly limited. The average particle diameter of the thermal spray material can be, for example, 50 μm or less, preferably 40 μm or less, and more preferably about 35 μm or less. The lower limit of the average particle diameter is not particularly limited, and can be set to, for example, 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, for example, 20 μm or more when considering the fluidity of the thermal spray material. can do.

[Sprayed coating]
A thermal spray coating can be formed by spraying the above thermal spraying material. This thermal spray coating is provided as a member with a thermal spray coating by being provided on the surface of the substrate. Hereinafter, the member with the thermal spray coating and the thermal spray coating will be described.
(Base material)
In the member with a thermal spray coating disclosed herein, the base material on which the thermal spray coating is formed is not particularly limited. For example, the material, shape, etc. are not particularly limited as long as it is a base material made of a material that can be subjected to thermal spraying of such a thermal spraying material and have desired resistance. Examples of the material constituting the base material include metal materials including various metals, metalloids and alloys thereof, and various inorganic materials. Specifically, examples of the metal material include metal materials such as aluminum, aluminum alloy, iron, steel, copper, copper alloy, nickel, nickel alloy, gold, silver, bismuth, manganese, zinc, and zinc alloy; silicon ( Group IV semiconductors such as Si) and germanium (Ge), II-VI group compound semiconductors such as zinc selenide (ZnSe), cadmium sulfide (CdS), and zinc oxide (ZnO), gallium arsenide (GaAs), and indium phosphide ( Group III-V compound semiconductors such as InP) and gallium nitride (GaN), Group IV compound semiconductors such as silicon carbide (SiC) and silicon germanium (SiGe), chalcopyrite semiconductors such as copper, indium selenium (CuInSe ₂ ), etc. And a semi-metal material. Examples of inorganic materials include calcium fluoride (CaF), quartz (SiO ₂ ) substrate materials, alumina (Al ₂ O ₃ ), oxide ceramics such as zirconia (ZrO ₂ ), silicon nitride (Si ₃ N ₄ ), and nitriding. Examples thereof include nitride ceramics such as boron (BN) and titanium nitride (TiN), and carbide ceramics such as silicon carbide (SiC) and tungsten carbide (WC). Any one of these materials may constitute a base material, or two or more of them may be combined to constitute a base material. Among them, steels typified by various SUS materials (so-called stainless steels) and the like, heat resistant alloys typified by Inconel, Invar, Kovar, etc., which have a relatively large thermal expansion coefficient among metal materials that are widely used. Preferred examples include a base material made of a low expansion alloy typified by, etc., a corrosion resistant alloy typified by Hastelloy, etc., an aluminum alloy typified by 1000 series to 7000 series aluminum alloys useful as a lightweight structural material, etc. . Such a base material may be, for example, a member that constitutes a semiconductor device manufacturing apparatus and that is exposed to highly reactive oxygen gas plasma or halogen gas plasma. Note that, for example, the above-described silicon carbide (SiC) and the like can be classified into different categories as compound semiconductors and inorganic materials for convenience, but are the same material.

(Sprayed coating)
The thermal spray coating disclosed here is formed by spraying the thermal spray material on the surface of an arbitrary base material, for example. Therefore, the thermal spray coating is configured as a coating mainly composed of a rare earth element oxyhalide (RE-OX) containing rare earth elements (RE), oxygen (O) and halogen elements (X) as constituent elements. Is done.
Here, “main component” means a component having the largest content among the constituent components constituting the thermal spray coating. Specifically, for example, it means that the component occupies 50% by mass or more of the entire sprayed coating, and preferably 75% by mass or more, for example, 80% by mass or more. Such a rare earth element oxyhalide is the same as that in the above-mentioned thermal spraying material, and therefore detailed description thereof is omitted.
Although the detailed mechanism is not clear, rare earth element oxyhalides are excellent in plasma erosion resistance, in particular, erosion resistance against halogen-based plasma. Therefore, the thermal spray coating containing a rare earth element oxyhalide as a main component can be extremely excellent in plasma erosion resistance.

This thermal spray coating is further characterized by substantially not containing the rare earth element fluoride. When a rare earth element fluoride is contained in the thermal spray coating, when the thermal spray coating is exposed to, for example, oxygen plasma, the portion where the rare earth element fluoride exists is easily oxidized. When the rare earth element oxide is generated by oxidation of the rare earth element fluoride, the rare earth element oxide becomes a partially deteriorated layer. The deteriorated layer portion (rare earth element oxide) is relatively hard but fragile, so when exposed to a plasma environment by dry etching or the like, the deteriorated layer portion may be peeled off to generate particles.
On the other hand, the thermal spray coating disclosed here contains substantially no rare earth element fluoride. Therefore, the generation of the bangles when exposed to plasma is suppressed, and the plasma erosion resistance can be further improved.

  Moreover, this sprayed coating is provided as a more preferable embodiment, which is substantially free of the rare earth element oxide. As described above, rare earth oxides are relatively hard but brittle, and therefore, particles can be generated when exposed to a plasma environment by subsequent dry etching or the like. Therefore, since the sprayed coating disclosed herein does not substantially contain this rare earth element oxide, it can be further excellent in plasma erosion resistance.

  Note that in dry etching apparatuses for manufacturing semiconductor devices, reduction in particles is required. Factors for generating particles include peeling of reaction products adhering to the inside of the vacuum chamber, and deterioration of the chamber by using halogen gas plasma or oxygen gas plasma. The larger the particle size, the more serious the problem. In recent years when the processing accuracy has become more precise, the generation of particles with a particle size of 0.2 μm or less (less than 0.2 μm, for example, 0.1 μm or less) must be strictly limited. Yes. According to the study by the present inventors, it has been confirmed that the number and size of particles generated from the sprayed coating in a dry etching environment are greatly influenced by the composition of the sprayed coating. For example, according to the conventional thermal spray coating, particles having a size of 0.2 μm or more could be generated, but by performing appropriate thermal spraying using the thermal spray material disclosed herein, thermal spraying having excellent plasma erosion resistance was achieved. A film can be obtained. Typically, for example, according to the thermal spray coating disclosed herein, a deteriorated layer that causes generation of coarse particles of about 0.2 μm or more is not formed under the current dry etching environment. When the thermal spray coating disclosed herein is corroded in a dry etching environment, the generated particles are constituted by a particulate alteration layer having a size of about 0.2 μm or less (typically 0.1 μm or less). This is because that. Accordingly, the thermal spray coating disclosed herein is, for example, about 0.2 μm or less (for example, 0.1 μm or less, typically 0.06 μm or less, preferably 19 nm or less, more preferably 5 nm or less, most preferably 1 nm or less). ) Particles are suppressed. For example, the number of occurrences of these particles is substantially suppressed to zero.

  The plasma erosion resistance of such a sprayed coating can be evaluated by, for example, the number of particles generated when this sprayed coating is exposed to a predetermined plasma environment. In dry etching, an etching gas is introduced into a vacuum vessel (chamber), and this etching gas is excited by high frequency, microwaves, or the like to generate plasma, thereby generating radicals and ions. By reacting radicals and ions generated by this plasma with the object to be etched (wafer) and exhausting the reaction product to the outside as a volatile gas by a vacuum exhaust system, fine processing is performed on the object to be etched. It can be carried out. For example, in an actual parallel plate RIE (reactive ion etching) apparatus, a pair of parallel plate electrodes are installed in an etching chamber (chamber). Then, a high frequency is applied to one electrode to generate plasma, and a wafer is placed on this electrode to perform etching. The plasma is generated in a pressure range of about 10 mTorr to 200 mTorr. As described above, various halogen gases, oxygen gases, and inert gases can be considered as the etching gas. When evaluating the plasma erosion resistance of the thermal spray coating, a mixed gas containing a halogen gas and an oxygen gas (for example, a mixed gas containing argon, carbon tetrafluoride and oxygen in a predetermined volume ratio) is used as an etching gas. Is preferred. The flow rate of the etching gas is preferably about 0.1 L / min or more and 2 L / min or less, for example.

Then, by measuring the number of particles generated after placing the sprayed coating in such a plasma environment for a predetermined time (for example, processing time of 2000 semiconductor substrates (silicon wafers, etc.)), the plasma resistance of the sprayed coating is measured. The erosion property can be suitably evaluated. Here, in order to realize advanced quality control, for example, particles having a diameter of 0.06 μm or more can be measured, but can be appropriately changed according to required quality. . And, for example, by calculating how many particles of such a size are deposited per unit area of the semiconductor substrate and calculating the number of particles generated (pieces / cm ² ), the plasma erosion resistance is evaluated. Can do.
About the preferable one aspect | mode of the sprayed coating disclosed here, it can recognize that this particle generation number is suppressed to about 15 pieces / cm < ² > or less. For example, the number of particles generated under the conditions specified below can be 15 / cm ² or less. Such a configuration is preferable because a thermal spray coating with improved plasma erosion resistance is realized.

[Particle count count condition]
A spray coating of 70 mm × 50 mm is placed on the upper electrode of the parallel plate type plasma etching apparatus. In addition, a substrate to be plasma processed having a diameter of 300 mm is set on the stage. First, in order to simulate the state after long-term use of the thermal spray coating, a dummy run of 100 hours is performed in which plasma dry etching is performed on 2000 substrates (silicon wafers). The plasma generation conditions are as follows: pressure: 13.3 Pa (100 mTorr), etching gas: mixed gas of argon, carbon tetrafluoride and oxygen, applied voltage: 13.56 MHz, 4000 W. Thereafter, a measurement monitor substrate (silicon wafer) is placed on the stage, and plasma is generated for 30 seconds under the same conditions as described above. Then, before and after the plasma treatment, the number of particles having a diameter of 0.06 μm or more deposited on the measurement monitor substrate is counted. At this time, a value obtained by dividing the number of counted particles by the area of the substrate may be used for evaluation as the number of generated particles (pieces / cm ² ). At this time, the etching gas is a mixed gas containing argon, carbon tetrafluoride, and oxygen. Further, the flow rate of the etching gas is, for example, 1 L / min.

(Film formation method)
In addition, said thermal spray coating can be formed by using the thermal spray material disclosed here for the thermal spraying apparatus based on the well-known thermal spraying method. A thermal spraying method for suitably spraying this thermal spraying material is not particularly limited. For example, preferably, a thermal spraying method such as a plasma spraying method, a high-speed flame spraying method, a flame spraying method, an explosion spraying method, an aerosol deposition method or the like is employed. The properties of the thermal spray coating may depend to some extent on the thermal spray method and the thermal spray conditions. However, even if any thermal spraying method and thermal spraying condition are adopted, the plasma erosion resistance is excellent by using the thermal spraying material disclosed here as compared with the case where other thermal spraying materials are used. It is possible to form a sprayed coating.

  Several examples relating to the present invention will be described below, but the present invention is not intended to be limited to those shown in the examples.

[Embodiment 1]
No. As a thermal spraying material 1, yttrium oxide powder generally used as a protective coating for members in a semiconductor device manufacturing apparatus was prepared. In addition, powdery yttrium-containing compound and fluorine-containing compound are appropriately mixed and fired, so 2-7 powdery thermal spray materials were obtained. The physical properties of these thermal spray materials were examined and are shown in Table 1 below.

The column of “XRD detection phase of thermal spray material” in Table 1 shows the detected crystal phase as a result of powder X-ray diffraction analysis for each thermal spray material. In the same column, “Y ₂ O ₃ ” is a phase composed of yttrium oxide, “YF 3” is a phase composed of yttrium fluoride, and “Y ₅ O ₄ F ₇ ” is composed of yttrium oxyfluoride whose chemical composition is represented by Y ₅ O ₄ F _7. The phase “YOF” indicates that a phase composed of yttrium oxyfluoride having a chemical composition represented by YOF (Y ₁ O ₁ F ₁ ) was detected. For this analysis, an X-ray diffraction analyzer (manufactured by RIGAKU, Ultimate IV) is used, CuKα rays (voltage 20 kV, current 10 mA) are used as the X-ray source, and the scanning range is 2θ = 10 ° to 70 °. Measurement was performed at a scan speed of 10 ° / min and a sampling width of 0.01 °. The divergence slit was adjusted to 1 °, the divergence length limiting slit was adjusted to 10 mm, the scattering slit was adjusted to 1/6 °, the light receiving slit was adjusted to 0.15 mm, and the offset angle was adjusted to 0 °.

The column of “X-ray diffraction main peak relative intensity” in Table 1 shows the intensity of the main peak of each detected crystal phase in the diffraction pattern obtained as a result of the above powder X-ray diffraction analysis for each thermal spraying material. It is the result shown as a relative value with the highest main peak intensity as 100. For reference, the main peak of each crystal phase is 29.157 ° for Y ₂ O ₃ , 27.881 ° for YF ₃ , 28.064 ° for YOF, and 28 for Y ₅ O ₄ F ₇ . Detected at 114 °.

The columns of “oxygen” and “fluorine” in Table 1 show the results of measuring the amount of oxygen and the amount of fluorine contained in each thermal spray material, respectively. These oxygen amounts are values measured using an oxygen / nitrogen / hydrogen analyzer (manufactured by LECO, ONH836), and the fluorine amounts are measured using an automatic fluorine ion measuring device (made by HORIBA, FLIA-101 type).
The column “Ratio of each crystal phase” in Table 1 shows the mass ratio of each crystal phase when the total amount of the four types of crystal phases detected for each thermal spray material is 100 mass%. The result calculated from the main peak relative intensity, the oxygen content, and the nitrogen content is shown.

  The column of “average particle size” in Table 1 indicates the average particle size of each thermal spray material. The average particle diameter is a volume-based value of D50% measured using a laser diffraction / scattering particle size distribution measuring apparatus (manufactured by HORIBA, LA-300).

As apparent from the ratio of each crystal phase in Table 1, No. As a thermal spraying material of 5 to 7, it was confirmed that the thermal spraying material disclosed here containing YOF in a ratio of 77% by mass or more and substantially not containing Y ₂ O ₃ was obtained.

[Embodiment 2]
No. prepared in the first embodiment. In addition to the thermal spraying materials 1-7, No. Particles made of yttrium oxyfluoride having four compositions were newly prepared as the thermal spraying materials 8-11. And these No. When X-ray diffraction analysis was performed on the thermal spray materials 8 to 11, none of the diffraction peaks derived from Y ₂ O ₃ and YF ₃ were detected in the obtained X-ray diffraction spectrum, and these thermal spray materials were In this order, it was confirmed to be composed of a substantially single phase of YOF, Y ₇ O ₆ F ₉ , Y ₆ O ₅ F ₈ , and Y ₅ O ₄ F ₇ . For reference, no. 8 and no. The X-ray diffraction spectra obtained for the 11 thermal spray materials are shown in order in FIGS.

By spraying these thermal spraying materials by the plasma spraying method, The member with a thermal spray coating provided with the thermal spray coating of 1-11 was produced. The thermal spraying conditions were as follows.
That is, first, as a base material which is a sprayed material, a plate material (70 mm × 50 mm × 2.3 mm) made of an aluminum alloy (Al6061) is prepared and subjected to a blast treatment with a brown alumina abrasive (A # 40). Using. The plasma spraying was performed using a commercially available plasma spraying apparatus (Praxair Surface Technologies, SG-100). As plasma generation conditions, argon gas 50 psi (0.34 MPa) and helium gas 50 psi (0.34 MPa) were used as plasma working gas, and plasma was generated under conditions of a voltage of 37.0 V and a current of 900 A. In addition, for supplying the thermal spray material to the thermal spray apparatus, a powder feeder (Praxair Surface Technologies, Model 1264 type) was used, and the thermal spray material was supplied to the thermal spray apparatus at a rate of 20 g / min, and the thickness was 200 μm. A sprayed coating was formed. The moving speed of the spray gun was 24 m / min, and the spray distance was 90 mm.

  The physical properties of the obtained thermal spray coating were examined and are shown in Table 2 below. The number of particles generated when the thermal spray coating was exposed to the halogen-based plasma was examined by the following three different methods, and the results are shown in Table 2. Of the data item columns shown in Table 2, those common to Table 1 show the results of examining the same content as in Table 1 for the sprayed coating.

The column of “Crystal Phase of Thermal Spray Material” in Table 2 shows the crystal phase constituting each thermal spray material and its approximate number based on the ratio of each crystal phase calculated in Embodiment 1 and the XRD analysis result. The ratio is shown.
The column of “XRD detection phase of sprayed coating” in Table 2 shows the detected crystal phase as a result of X-ray diffraction analysis of each sprayed coating. In Table 2, “Y6O5F8” is a phase composed of yttrium oxyfluoride whose chemical composition is represented by Y ₆ O ₅ F ₈ , and “Y7O6F9” is yttrium oxyfluoride whose chemical composition is represented by Y ₇ O ₆ F _9. The other phases are the same as those shown in Table 1. For reference, the main peak of Y ₆ O ₅ F ₈ is detected at 28.139 °, and Y ₇ O ₆ F ₉ is detected at 28.137 °.

  Moreover, the column of “porosity” in Table 2 shows the measurement results of the porosity of each thermal spray coating. The porosity was measured as follows. That is, the thermal spray coating was cut at a plane orthogonal to the surface of the base material, and the obtained cross section was resin-filled and polished, and then a cross section image was taken using a digital microscope (OM-7, VC-7700). . Then, by analyzing this image using image analysis software (Image Pro, manufactured by Nippon Roper Co., Ltd.), the area of the pore portion in the cross-sectional image is specified, and the ratio of the area of the pore portion to the entire cross section Was calculated by calculating.

  The column “Vickers hardness” in Table 2 shows the measurement results of the Vickers hardness of each thermal spray coating. The Vickers hardness was measured according to JIS R1610: 2003 using a hard microhardness measuring device (manufactured by Shimadzu Corporation, HMV-1) and applying a test force of 1.96 N with a diamond indenter with a facing angle of 136 °. Vickers hardness (Hv0.2) sometimes required.

  The column “number of particles [1]” in Table 2 shows the results of evaluating the number of particles generated when each sprayed coating was exposed to plasma under the following conditions. That is, first, the surface of the thermal spray coating of the member with the thermal spray coating prepared above was mirror-polished using colloidal silica having an average particle size of 0.06 μm. The member with the thermal spray coating was placed on the member corresponding to the upper electrode in the chamber of the parallel plate type semiconductor device manufacturing apparatus so that the polished surface was exposed. Then, a silicon wafer having a diameter of 300 mm was placed on the stage in the chamber, and a dummy run for performing plasma dry etching on 2000 silicon wafers was performed for 100 hours. The plasma in the etching process is 4000 W at 13.56 MHz while maintaining the pressure in the chamber at 13.3 Pa and supplying an etching gas containing argon, carbon tetrafluoride, and oxygen at a predetermined rate at a flow rate of 1 L / min. It was generated by applying high frequency power. Thereafter, a silicon wafer having a diameter of 300 mm for particle counting was placed on the stage in the chamber, and when plasma was generated for 30 seconds under the same conditions as described above, it was deposited from the sprayed coating on the silicon wafer for particle counting. Counted the number of particles. The total number of particles having a diameter of 0.06 μm (60 nm) or more was measured using a particle counter (wafer surface inspection device, Surfscan SP2) manufactured by KLA-Tencor. When counting the total number of particles, the number of particles on the silicon wafer is counted before and after 30 seconds of plasma etching, and the difference is the number of particles generated from the sprayed coating after endurance (after the dummy run) and deposited on the silicon wafer. (Total). In addition, the evaluation of the number of generated particles is No. 100% yttria. Evaluation was performed by calculating the relative value when the total number of particles for one thermal spray coating was 100 (reference).

  “A” described in the column of the number of particles [1] indicates a case where the number of particles (relative value) is less than 1, “B” indicates a case where the number of particles is 1 or more and less than 5, “C” indicates a case where the number of particles is 5 or more and less than 15, “D” indicates a case where the number of particles is 15 or more and less than 100, and “E” indicates a case where the number of particles is 100 or more.

  In the column of “number of particles [2]” in Table 2, the number of generated particles when plasma etching is performed on each sprayed coating under the same conditions as described above is the wafer surface inspection device manufactured by KLA-Tencor, Surfscan SP2. Instead, the evaluation results when measured using Surfscan SP5 are shown. Surfscan SP5 is capable of detecting particles having a diameter of 19 nm or more, and the number of particles [2] indicates a result when measuring even finer particles deposited on a silicon wafer. When counting the total number of particles, the number of particles on the silicon wafer is counted before and after the plasma etching for 30 seconds, and the difference is calculated as the number of particles (total number) generated from the sprayed coating after durability and deposited on the silicon wafer. did. In addition, the evaluation of the number of generated particles is No. 100% yttria. Evaluation was performed by calculating the relative value when the total number of particles for one thermal spray coating was 100 (reference).

  “A” described in the column of the number of particles [2] indicates a case where the number of particles (relative value) is less than 1, “B” indicates a case where the number of particles is 1 or more and less than 5, “C” indicates a case where the number of particles is 5 or more and less than 15, “D” indicates a case where the number of particles is 15 or more and less than 100, and “E” indicates a case where the number of particles is 100 or more. Yes.

The column “number of particles [3]” in Table 2 indicates that each sprayed coating is irradiated with plasma under the following conditions, and then ultrasonic waves are applied to actively release particles from the sprayed coating. The result of measuring the number of particles is shown.
Specifically, in this example, after the coating surface of the prepared thermal spray coating member is mirror-polished, a test piece having a 10 mm × 10 mm thermal spray coating exposed is prepared by masking the four corners of the thermal spray coating with a masking tape. did. And this test piece was installed in the upper electrode of the semiconductor device manufacturing apparatus, and the etching gas containing carbon tetrafluoride and oxygen at a predetermined ratio was maintained at a flow rate of 1 L / min while maintaining the pressure in the chamber at 13.3 Pa. The test piece was exposed to plasma by supplying and applying high frequency power of 700 W at 13.56 MHz for a total of 1 hour. After that, Air is supplied into the chamber, and by applying ultrasonic waves with a frequency of 22 Hz and an output of 400 W for 30 seconds to the sprayed coating of the test piece after the plasma exposure, particles are knocked out of the sprayed coating, and particles in the Air are removed. Measured at the counter. For the measurement of particles, a particle counter (manufactured by PMS, LASAIR) was used, and the total number of particles having a diameter of 100 nm or more was measured. The results are shown in No. 100% yttria. Evaluation was performed by calculating the relative value when the total number of particles for one thermal spray coating was 100 (reference).

  “A” described in the column of the number of particles [3] indicates a case where the number of particles (relative value) is less than 10, and “B” indicates a case where the number of particles is 10 or more and less than 25. “C” indicates the case where the number of particles is 25 or more and less than 50, “D” indicates the case where the number of particles is 50 or more and less than 90, and “E” indicates the case where the number of particles is 90 or more. Yes.

(Evaluation)
No. in Table 2 As is apparent from the results, Y 2 _O 3 sprayed coating formed by thermal spraying a spraying material consisting of _(yttrium oxide) only, consists essentially of Y ₂ O _3, in spray Y ₂ It was found that no further oxidative decomposition of O ₃ was observed.
No. From the results of 2 to 4, it was found that a part of the thermal spraying material containing yttrium fluoride (YF ₃ ) was oxidized by thermal spraying to form yttrium oxyfluoride in the thermal spray coating. When the proportion of YF ₃ in the thermal spray material is relatively large, the chemical composition of the yttrium oxyfluoride formed is the composition of the yttrium oxyfluoride coexisting in the thermal spray material (in this example, Y ₅ O ₄ F ₇ ), but no. As shown in FIG. 4, when the proportion of YF ₃ in the thermal spray material decreases and the degree of oxidation of YF ₃ increases, yttrium oxyfluoride having a higher oxygen content in the thermal spray coating (in this example, Y ₆ O ₅ it has been found that F ₈ or YOF) is formed.

No. From the results of 5 to 8, when the amount of yttrium oxyfluoride (here, YOF) in the thermal spray material increases to 77% by mass or more, YOF is hardly decomposed and YF ₃ is preferentially decomposed, and more in the thermal spray coating. Of YOF remained. Moreover, YF ₃ is formed that forms a Y ₂ O ₃ in the thermal spray coating in further oxidative decomposition proceeds by thermal spraying, also the Y ₂ O ₃ when YOF a part by thermal spraying is oxidative degradation during thermal spray coating I was able to confirm.
On the other hand, no. According to the results of 8 to 11, among yttrium oxyfluorides in the thermal spray material, Y ₇ O ₆ F ₉ , Y ₆ O ₅ F _8, Y ₅ O ₄ F _7, etc., which have a lower oxygen content than YOF, etc. It was found that oxidation by thermal spraying first changed to a more stable YOF phase, and Y ₂ O ₃ was not directly formed. That is, it was confirmed that the formation of Y ₂ O ₃ in the thermal spray coating can be suppressed by using yttrium oxyfluoride having a lower oxygen content than YOF as the thermal spray material.

Regarding the number of particles [1] No. The number of particles generated in the plasma environment of the thermal spray coating composed of only one Y ₂ O _{3 in} the plasma environment is (E) 100 (standard), and the number of particles on the silicon wafer is about 500 to 1000 / sheet. Reached. Of the measured particles, approximately 90% or more were extremely fine particles that had not been controlled so far in the range of diameters of 0.06 μm or more and less than 0.2 μm. In general, it is known that yttria-based thermal spray coatings are superior in plasma erosion resistance compared to alumina-based thermal spray coatings and the like, but in this embodiment, the number of particles of the thermal spray coating consisting of Y ₂ O ₃ is the largest. There were many, and it was the result inferior to the plasma resistance among all the sprayed coatings.

No. It was found that the thermal spray coating containing 2 to 4 YF ₃ also had poor plasma resistance, with the number of particles generated in the plasma environment being (E) 100 or more. If YF ₃ is present in the thermal spray coating, oxidation is likely to occur when exposed to oxygen plasma. When Y ₂ O ₃ is generated by oxidation of YF _{3 in} the sprayed coating, this Y ₂ O ₃ portion becomes a deteriorated layer. The deteriorated layer is fragile, and when it is exposed to the plasma environment by the next dry etching, the deteriorated layer is peeled off and becomes particles and easily deposits on the semiconductor substrate. Therefore, it has been confirmed that the plasma erosion resistance is lowered when YF ₃ is contained in the thermal spray coating.

In addition, No. As is clear from the examples of 5 to 11, the thermal spray coating that does not contain YF ₃ has less than (A) to (D) 100 particles generated under the plasma environment even if Y ₂ O ₃ is contained. It was found that it can be suppressed to a small amount. This is considered to be due to the fact that YOF present in the sprayed coating is extremely stable against plasma and exhibits the effect of suppressing peeling of the Y ₂ O ₃ altered layer by plasma.
No. From the results of 5 to 8, the number of particles tended to decrease as the proportion of Y ₂ O ₃ in the sprayed coating decreased.

And No. As shown in 9 to 11, the thermal spray coating substantially containing only yttrium oxyfluoride does not contain YF ₃ or Y ₂ O _{3 and the} number of particles is extremely less than (A) to (B) 5; It was confirmed that the amount could be reduced to a small amount. These sprayed coatings show good values in good balance between porosity and Vickers hardness, and it can be said that a good quality sprayed coating is formed. It was confirmed that almost all of these particles were extremely small with a diameter of 0.06 μm or more and less than 0.2 μm.
In addition, No. 2 formed using Y ₇ O ₆ F ₉ and Y ₆ O ₅ F ₈ as the thermal spraying material. Nos. 9 and 10 have a particle number of less than (A) 1 and No. 1 formed using Y ₅ O ₄ F ₇ as the thermal spraying material. It was found that the plasma erosion resistance was superior to the thermal spray coating of No. 11. From the viewpoint of porosity, no. It can be said that the thermal spray coating of 11 is more preferable.

From the above, it was found that the plasma erosion resistance of the thermal spray coating not containing YF ₃ is greatly improved. In particular, it has been found that the plasma erosion resistance is further improved by including yttrium oxyfluoride in the spray coating and further by reducing the proportion of Y ₂ O ₃ .

In addition, in order to form a thermal spray coating having excellent plasma erosion resistance, thermal spraying is performed using a thermal spray material containing yttrium oxyfluoride in a proportion of 77% by mass or more and substantially free of Y ₂ O _3. I knew it was good. Note that YF ₃ may be contained in the thermal spray material, but in order to prevent YF ₃ from remaining in the thermal spray coating, the ratio of YF ₃ in the thermal spray material is, for example, 25% by mass or less (more preferably It has been found that it is better to set it to about 23% or less. It has also been confirmed that a thermal spray coating having particularly excellent plasma erosion resistance can be formed by thermal spraying using a thermal spray material substantially consisting of yttrium oxyfluoride.

About the number of particles [2] As shown in Table 2, it was found that the evaluation result of the number of particles [2] roughly corresponds to the evaluation result of the number of particles [1]. For the number of particles [2], no. It was confirmed that the generation ratio of finer particles slightly increased from C to D only for the thermal spray coating obtained from the thermal spray material consisting of 8 100% YOF. _However, consisting only of Y 2 _{O 3} No. As compared with the thermal spray coating of No. 1, it was found that the other thermal spray coatings had a relatively large decrease in particles, and in particular, the generation of fine particles of 19 to 60 nm was suppressed to a small amount. The particle of 19 nm or more is the smallest particle size that can be measured at this stage, and the result is that such fine particles are almost close to zero. Thereby, it was confirmed that the thermal spray coating which is a thermal spray material of the thermal spray material disclosed here still exhibits high plasma erosion resistance even if the accuracy of the lower limit of detection of particles is increased.

About the number of particles [3] As shown in Table 2, it was found that the evaluation result of the number of particles [3] corresponds well with the evaluation result of the number of particles [2]. However, the particles detected by the number of particles [3] are relatively coarse particles of 100 nm or more, and the critical values of A to D are classified so that the evaluation is close to E. That is, according to the number of particles [3], more coarse particles can be generated and detected by the impact of ultrasonic waves. From this, according to the number of particles [3], in addition to the particles directly generated by the irradiation of the halogen-based plasma, it can be said that a particle generation source that is not actually generated but can become a particle thereafter can be evaluated. . This particle generation source is considered to be a sprayed coating (modified layer) that has been altered by irradiation with halogen-based plasma, and a portion that can become particles by subsequent plasma etching. From this, it can be said that the plasma erosion resistance of the thermal spray coating can be more accurately evaluated by irradiating the thermal spray coating exposed to the halogen-based plasma with ultrasonic waves. Further, according to the number of particles [3], for example, it can be said that the generation state of particles derived from the thermal spray coating can be predicted when a silicon wafer is processed in a larger amount than 2000 sheets. From the results in Table 2, for example, No. For the thermal spray coatings 6-8, it was confirmed that the generation of particles when exposed to the halogen-based plasma was suppressed to a higher degree.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

Claims (11)

Rare earth element oxyhalides (RE-O-X) containing rare earth elements (RE), oxygen (O) and halogen elements (X) as constituent elements are contained in a proportion of 77% by mass or more of the whole,
A thermal spray material substantially free of oxide of the rare earth element.   Furthermore, the material for thermal spraying of Claim 1 in which the fluoride of the said rare earth element is contained in the ratio of 23 mass% or less of the whole.   The thermal spray material according to claim 1, which is substantially free of the halide of the rare earth element. In the rare earth element oxyhalide,
The thermal spray material according to any one of claims 1 to 3, wherein a molar ratio (X / RE) of the halogen element to the rare earth element is 1.1 or more.   The thermal spray material according to claim 4, wherein a molar ratio (O / RE) of the oxygen to the rare earth element is 0.9 or less.   The thermal spray material according to any one of claims 1 to 5, wherein the rare earth element is yttrium, the halogen element is fluorine, and the rare earth element oxyhalide is yttrium oxyfluoride.   The thermal spray coating which is a thermal spray material of the thermal spray material of any one of Claims 1-6. The main component is a rare earth element oxyhalide (RE-O-X) containing rare earth elements (RE), oxygen (O) and halogen elements (X) as constituent elements,
A thermal spray coating substantially free of fluoride of the rare earth element.   The thermal spray coating according to claim 8, which is substantially free of the oxide of the rare earth element.   The thermal spray coating according to claim 8 or 9, wherein the rare earth element is yttrium, the halogen element is fluorine, and the rare earth element oxyhalide is yttrium oxyfluoride.   The member with a thermal spray coating in which the thermal spray coating of any one of Claims 7-10 is provided on the surface of the base material.

Images