Sputtering material, sputtering film, method for forming sputtering film, member for plasma etching device

Abstract

Provided is a sputtered coating film that is excellent in plasma etching resistance, can protect a member of a plasma etching device from the influence of plasma etching for a long period of time, contributes to stable production of the device, and contributes to long life of the member. A sputtering material of one embodiment of the present application is formed of a complex compound that contains rare earth fluoride at a proportion of 40 mol% or more and 80 mol% or less, contains magnesium fluoride at a proportion of 10 mol% or more and 40 mol% or less, and contains calcium fluoride at a proportion of 0 mol% or more and 40 mol% or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a sputtering material, a sputtering coating film, a method for forming a sputtering coating film, and a member for a plasma etching apparatus. BACKGROUND

[0002] In the field of manufacturing semiconductor devices, fine processing is generally performed on the surface of a semiconductor substrate by dry etching using a halogen gas such as fluorine, chlorine, or bromine in the interior of a vacuum chamber. After the dry etching, the interior of the chamber after the semiconductor substrate is removed is cleaned using an oxygen plasma. Along with this, a member exposed to the reactive plasma in the chamber can be eroded and thinned, and the eroded portion can be detached as particles. If the particles adhere to the semiconductor substrate, defects can be caused in the circuit.

[0003] Thus, in order to reduce the generation of particles, a member exposed to the reactive plasma in the chamber has been provided with a sputtering coating film having high resistance to plasma erosion, so as to protect the member from the effects of plasma erosion.

[0004] For example, Patent Document 1 describes that, as a sputtering coating film having high resistance to plasma erosion, a dense fluoride ceramic layer having a porosity of 2% or less and composed of at least one selected from CaF2, MgF2, YF3, AlF3, and CeF3 as a main body.

[0005] Patent Document 2 describes that, in order to form a coating film that is less likely to generate large particles when eroded by a plasma, a member exposed to a reactive plasma is sputtered with a sputtering powder containing a rare earth element and a Group 2 element of the periodic table, and an oxide coating film is formed.

[0006] Patent Document 3 describes a sputtering material containing composite particles in which a plurality of yttrium fluoride particles are integrated, and having a lightness L of 91 or less in the Lab color space, as a sputtering material capable of forming a sputtering coating film having improved resistance to plasma erosion.

[0007] In Patent Literature 4, as a substrate with a sputter-coated film having high plasma resistance on the surface of the substrate, being difficult to peel, excellent acid resistance, and high surface resistance, a substrate satisfying the following constitutions (1) to (4) is described. (1) The thickness of the film is 10 to 1000 μm. (2) The film contains a fluoride and an oxide of a rare earth element (Ln) as a main component. (3) On the surface of the film, a granular portion [α1] having a monoclinic crystal structure and a diameter of 10 nm to 1 μm and a granular portion [β1] having an orthorhombic crystal structure and a diameter of 10 nm to 1 μm of a fluoride of a rare earth element (Ln) are dispersed in a matrix of an amorphous substance of a fluoride of a rare earth element (Ln). (4) If the surface of the film is observed at 200 times using an optical microscope, a white patchy portion having a maximum diameter of 50 to 1000 μm is confirmed, and the area ratio of the patchy portion in the field of view is 0.01 to 2%.

[0008] Prior Art Documents

[0009] Patent Literature

[0010] Patent Literature 1: Japanese Patent Application Laid-Open (JP-A) No. 2000-219574

[0011] Patent Literature 2: Japanese Patent No. 6261980

[0012] Patent Literature 3: WO 2018 / 052129

[0013] Patent Literature 4: Japanese Patent Application Laid-Open (JP-A) No. 2017-172021 SUMMARY

[0014] PROBLEMS TO BE SOLVED BY THE INVENTION

[0015] However, the sputter-coated film described in Patent Literatures 1 to 4 has room for improvement in terms of excellent plasma etching resistance, long-term protection of members of a plasma etching device from the influence of plasma etching, and the like.

[0016] The present application has an object to provide a sputter-coated film having excellent plasma etching resistance, capable of long-term protection of members of a plasma etching device from the influence of plasma etching, contributing to stable production of equipment, and long service life of the members.

[0017] SOLUTION TO THE PROBLEM

[0018] To solve the above problems, a first aspect of the present application provides a sputtering material formed of a compound that contains a rare earth fluoride at a ratio of 40 mol% or more and 80 mol% or less, a magnesium fluoride at a ratio of 10 mol% or more and 40 mol% or less, and a calcium fluoride at a ratio of 0 mol% or more and 40 mol% or less.

[0019] A second aspect of the present application provides a sputtering coating film that contains a rare earth fluoride at a ratio of 40 mol% or more and 80 mol% or less, a magnesium fluoride at a ratio of 10 mol% or more and 40 mol% or less, and a calcium fluoride at a ratio of 0 mol% or more and 40 mol% or less, the sputtering coating film containing a crystalline phase and an amorphous phase, and a degree of crystallinity being 1% or more and 75% or less.

[0020] Effects of the Invention

[0021] The sputtering material according to the first aspect of the present application can form a sputtering coating film that is excellent in plasma etching resistance, can protect a member of a plasma etching device from plasma etching for a long period of time, and is useful for stable production of equipment and long life of the member.

[0022] The sputtering coating film according to the second aspect of the present application can form a sputtering coating film that is excellent in plasma etching resistance, can protect a member of a plasma etching device from plasma etching for a long period of time, and is useful for stable production of equipment and long life of the member.

[0023] The method of forming a sputtering coating film using the sputtering material according to the first aspect of the present application can form a sputtering coating film that is excellent in plasma etching resistance, can protect a member of a plasma etching device from plasma etching for a long period of time, and is useful for stable production of equipment and long life of the member. DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present application will be described, but the present application is not limited to the embodiments shown below. In the embodiments shown below, preferred limitations are made in the technical field for implementing the present application, but the limitations are not essential conditions of the present application.

[0025] The sputtering material of the present embodiment is formed of a compound that contains a fluoride of a rare earth element at a ratio of 40 mol% or more and 80 mol% or less, a magnesium fluoride at a ratio of 10 mol% or more and 40 mol% or less, and a calcium fluoride at a ratio of 0 mol% or more and 40 mol% or less. The ratio of the magnesium fluoride is preferably 20 mol% or more and 40 mol% or less.

[0026] The fluoride of the rare earth element is preferably yttrium fluoride.

[0027] The composite is a granulated powder of yttrium fluoride primary particles having an average particle diameter of 10 μm or less, magnesium fluoride primary particles having an average particle diameter of 10 μm or less, and calcium fluoride primary particles having an average particle diameter of 10 μm or less. The average particle diameter of the granulated powder is preferably 5 μm or more and 40 μm or less.

[0028] The composite is preferably a granulated sintered powder obtained by sintering the granulated powder.

[0029] The sputtered coating film formed by sputtering the sputtering material of the present embodiment using general conditions is a sputtered coating film containing a fluoride of a rare earth element at a proportion of 40 mol% or more and 80 mol% or less, containing magnesium fluoride at a proportion of 10 mol% or more and 40 mol% or less, containing calcium fluoride at a proportion of 0 mol% or more and 40 mol% or less, containing a crystalline phase and an amorphous phase, and having a crystallinity of 1% or more and 75% or less. The crystallinity of the sputtered coating film can be calculated from a diffraction pattern obtained by X-ray diffraction.

[0030] The fluoride of the rare earth element is preferably yttrium fluoride.

[0031] The sputtered coating film preferably has a porosity of 2.0 area% or less.

[0032] The method of forming a sputtered coating film of the present embodiment is a method of forming a sputtered coating film using a composite containing a fluoride of a rare earth element at a proportion of 40 mol% or more and 80 mol% or less, containing magnesium fluoride at a proportion of 10 mol% or more and 40 mol% or less, and containing calcium fluoride at a proportion of 0 mol% or more and 40 mol% or less, the sputtered coating film containing a fluoride of a rare earth element at a proportion of 40 mol% or more and 80 mol% or less, containing magnesium fluoride at a proportion of 10 mol% or more and 40 mol% or less, and containing calcium fluoride at a proportion of 0 mol% or more and 40 mol% or less, the sputtered coating film containing a crystalline phase and an amorphous phase.

[0033] The composite used in the method preferably contains a fluoride of a rare earth element at a proportion of 40 mol% or more and 80 mol% or less, contains magnesium fluoride at a proportion of 20 mol% or more and 40 mol% or less, and contains calcium fluoride at a proportion of 0 mol% or more and 40 mol% or less.

[0034] The fluoride of the rare earth element constituting the composite used in the method is preferably yttrium fluoride.

[0035] According to the method of forming a sputtered coating film of the present embodiment, it is possible to form a sputtered coating film having a porosity of 2.0 area% or less.

[0036] According to the sputtering film formation method of the present embodiment, a sputtering film having a crystallinity of 1% or more and 75% or less can be formed.

[0037] The plasma etching device member of the present embodiment is a plasma etching device member having a surface covered with the sputtering film described above.

[0038] According to the sputtering material of the present embodiment, a sputtering film excellent in plasma etching resistance, capable of protecting members of a plasma etching device from plasma etching for a long period of time, and contributing to stable production of equipment and long life of members can be formed.

[0039] The sputtering film of the present embodiment is expected to be a sputtering film excellent in plasma etching resistance, capable of protecting members of a plasma etching device from plasma etching for a long period of time, and contributing to stable production of equipment and long life of members.

[0040] According to the sputtering film formation method of the present embodiment, a sputtering film excellent in plasma etching resistance, capable of protecting members of a plasma etching device from plasma etching for a long period of time, and contributing to stable production of equipment and long life of members can be formed.

[0041] [Method for producing sputtering material]

[0042] The complex of the sputtering material constituting the first aspect of the present invention is formed of a material containing at least a fluoride of a rare earth element and a fluoride of a second group element. The complex can be produced by granulating primary particles formed of a fluoride of a rare earth element and primary particles formed of a fluoride of a second group element into, for example, a spherical shape. Alternatively, the complex can be produced by further sintering the granulated powder while maintaining the composition of the primary particles.

[0043] There is no particular limitation on the granulation method, and various publicly known granulation methods can be used. Specifically, for example, one or more of a tumbling granulation method, a fluidized layer granulation method, a stirring granulation method, a compression granulation method, an extrusion granulation method, a crushing granulation method, a spray drying method, and the like can be used. The spray drying method is preferred. In the calcination of the granulated powder, a general batch-type calcination furnace, a continuous calcination furnace, or the like can be used without particular limitation.

[0044] In a general granulated powder, fine particles of primary particles are, for example, in a state of being simply and integrally aggregated (bound based on a binder) with a binder. A large pore is trapped in the gap of the fine particles of the granulated powder. As such, in a general granulated powder, a "granulation" is meant by the presence of a large pore between the fine particles.

[0045] On the other hand, if the granulated powder is sintered, the binder disappears, and the fine particles directly bond in order to reduce surface energy. Thus, the composite particles are realized by the above-described integral bonding. Note that if the sintering is advanced, the area of the bonding portion (interface) gradually increases, and the bonding strength further increases. In addition, the fine particles become more stable spherical shape with a curvature due to the movement of the substances in the sintered particles. At the same time, the pores present inside the granulated powder are expelled, and densification occurs.

[0046] The calcination conditions for sintering are not limited as long as the composition of the primary particles does not change in a state where sintering is sufficiently performed at one time. As for the calcination conditions, heating at 600°C or higher and less than the melting point (for example, less than 1200°C) in a non-oxidizing atmosphere can be taken as a general guideline.

[0047] The calcination atmosphere can be set to, for example, a non-active atmosphere, a vacuum atmosphere, so that the composition does not change. The non-active atmosphere at this time means an atmosphere that does not contain oxygen, and can be set to a rare gas atmosphere such as argon (Ar), neon (Ne), helium (He), a non-oxidizing atmosphere such as nitrogen (N2), or the like. Note that in the case of using a batch calcination furnace, for example, the atmosphere inside the furnace can be set to a non-oxidizing atmosphere. In addition, in the case of using a continuous calcination furnace, for example, a non-oxidizing gas stream can be introduced into the region where heating is performed (the region where sintering is performed) in the calcination furnace to perform sintering.

[0048] [About the base material]

[0049] In the plasma etching device member (the base material with a coating film having a coating film on the surface) in which the sputter coating film of the second aspect of the present application coats the surface, the base material to be formed with the sputter coating film is not particularly limited. For example, as long as it is a base material formed of a material that can have a desired resistance to sputtering of a sputtering material, the material, shape, and the like are not particularly limited. As the material constituting the base material, various metals, semimetals, and metal materials including alloys thereof, various inorganic materials, and the like can be listed.

[0050] Specifically, as the metal material, for example, a metal material such as aluminum, an aluminum alloy, iron, steel, copper, a copper alloy, nickel, a nickel alloy, gold, silver, bismuth, manganese, zinc, a zinc alloy, or the like; a Group IV compound semiconductor such as silicon (Si) or germanium (Ge); a Group II-VI compound semiconductor such as zinc selenide (ZnSe), cadmium sulfide (CdS), or zinc oxide (ZnO); a Group III-V compound semiconductor such as gallium arsenide (GaAs), indium phosphide (InP), or gallium nitride (GaN); a Group IV compound semiconductor such as silicon carbide (SiC) or silicon germanium (SiGe); a semimetal material such as a chalcopyrite semiconductor such as copper-indium-selenium (CuInSe2), or the like; or the like can be exemplified. As the inorganic material, for example, a substrate material such as calcium fluoride (CaF2) or quartz (SiO2); an oxide ceramic such as aluminum oxide (Al2O3) or zirconium oxide (ZrO2); a nitride ceramic such as silicon nitride (Si3N4), boron nitride (BN), or titanium nitride (TiN); a carbide ceramic such as silicon carbide (SiC) or tungsten carbide (WC); or the like can be exemplified.

[0051] Any of these materials can constitute the base material, or two or more of these materials can be compounded to constitute the base material. Among these, as suitable examples, a base material formed of steel represented by various SUS materials (which can be so-called stainless steel), a heat-resistant alloy represented by Inconel or the like, a low-expansion alloy represented by nickel-iron alloy, iron-nickel-cobalt alloy, or the like, a corrosion-resistant alloy represented by nickel-based alloy resistant to hydrochloric acid, or the like, an aluminum alloy represented by 1000 series to 7000 series aluminum alloy, which is useful as a lightweight structural material or the like, or the like, having a large coefficient of thermal expansion among general metal materials, can be exemplified.

[0052] The base material can be, for example, a member constituting a semiconductor device manufacturing apparatus that is exposed to an oxygen plasma having high reactivity, a halogen gas plasma, or the like. Note that, for example, silicon carbide (SiC) or the like is classified into different categories as a compound semiconductor, an inorganic material, or the like for the convenience of use or the like, and can be the same material.

[0053] [Method for forming sputtered coating film]

[0054] The sputtered coating film of the second mode can be formed by supplying the sputtering material of the first mode to a sputtering apparatus based on a publicly known sputtering method. In other words, a sputtered coating film formed of the material is formed by blowing a sputtering material in the form of a powder while softening or melting the sputtering material using a heat source such as combustion or electric energy. The sputtering method for sputtering the sputtering material is not particularly limited. For example, a sputtering method such as a plasma sputtering method, a high-speed flame sputtering method, a flame sputtering method, a detonation sputtering method, or the like can be exemplified as being suitable.

[0055] The properties of the sprayed film depend to some extent on the spraying method and its spraying conditions. However, with any spraying method and spraying conditions, by using the spraying material disclosed herein, a sprayed film with improved resistance to plasma erosion can be formed compared to the case of using other spraying materials.

[0056] The plasma spraying method is a spraying method in which a plasma flame is used as a spraying heat source for softening or melting the spraying material. If an arc is generated between electrodes and the arc is used to plasma-ize a working gas, the plasma stream forms a high-temperature high-speed plasma jet from a nozzle and is ejected. The plasma spraying method generally includes a coating method in which the spraying material is heated and accelerated by being thrown into the plasma jet to be deposited on a substrate to obtain a sprayed film.

[0057] Note that the plasma spraying method can be atmospheric plasma spraying (APS) performed in the atmosphere, low pressure plasma spraying (LPS) performed at a pressure lower than atmospheric pressure, high pressure plasma spraying performed in a pressurized container at a pressure higher than atmospheric pressure, or the like. According to the plasma spraying, for example, by using a plasma jet of about 5000°C to 10000°C to melt and accelerate the spraying material, the spraying material can be made to impact on and be deposited on a substrate at a speed of about 300 m / s to 600 m / s.

[0058] Example

[0059] Hereinafter, an example of the present application will be described.

[0060] [Production of Spraying Material]

[0061] <No. 1>

[0062] First, yttrium fluoride (YF3) powder having an average primary particle diameter of 3.0 μm, calcium fluoride (CaF2) powder having an average primary particle diameter of 1.0 μm, and magnesium fluoride (MgF2) powder having an average primary particle diameter of 4.0 μm were dispersed in a dispersing medium at a ratio of 50 mol% of YF3, 20 mol% of CaF2, and 30 mol% of MgF2, together with a resin binder, to obtain a raw material dispersion liquid. The resin binder was set at a ratio of 1.0 parts by mass with respect to 100 parts by mass of the total powder.

[0063] Next, the raw material dispersion liquid was sprayed into a gas stream using a spray dryer, and granulated powder was produced by evaporating the dispersion medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed under an Ar atmosphere at 800°C for about 120 minutes, whereby granulated sintered powder was obtained. The composition of the obtained granulated sintered powder was not changed, with YF3 being 50 mol%, CaF2 being 20 mol%, and MgF2 being 30 mol%, and the average particle diameter of the particles classified using a sieve and an air current was 30 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 1.

[0064] <No. 2>

[0065] First, a yttrium fluoride (YF3) powder having an average primary particle diameter of 1.0 μm and a magnesium fluoride (MgF2) powder having an average primary particle diameter of 4.0 μm were dispersed in a dispersion medium together with a resin binder at a ratio of YF3 being 64 mol% and MgF2 being 36 mol%, whereby a raw material dispersion liquid was obtained. The resin binder was set at a proportion of 1.0 part by mass with respect to 100 parts by mass of the total powders.

[0066] Next, the raw material dispersion liquid was sprayed into a gas stream using a spray dryer, and granulated powder was produced by evaporating the dispersion medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed under an Ar atmosphere at 800°C for about 120 minutes, whereby granulated sintered powder was obtained. The composition of the obtained granulated sintered powder was not changed, with YF3 being 50 mol%, CaF2 being 20 mol%, and MgF2 being 30 mol%, and the average particle diameter of the particles classified using a sieve and an air current was 30 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 1.

[0067] <No. 3>

[0068] First, a yttrium fluoride (YF3) powder having an average primary particle diameter of 1.0 μm and a magnesium fluoride (MgF2) powder having an average primary particle diameter of 4.0 μm were dispersed in a dispersion medium together with a resin binder at a ratio of YF3 being 64 mol% and MgF2 being 36 mol%, whereby a raw material dispersion liquid was obtained. The resin binder was set at a proportion of 1.0 part by mass with respect to 100 parts by mass of the total powders.

[0069] Next, the raw material dispersion liquid was sprayed into a gas stream using a spray dryer, and granulated powder was produced by evaporating the dispersion medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed under conditions of N2atmosphere, 850°C for about 120 minutes, whereby granulated sintered powder was obtained. In the composition of the obtained granulated sintered powder, YF3was 50 mol%, CaF2was 25 mol%, and MgF2was 25 mol%, and did not change, and the average particle diameter of the particles classified using a sieve and an air current was 30 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 3.

[0070] <No. 4>

[0071] First, yttrium fluoride (YF3) powder having an average primary particle diameter of 2.0 μm, calcium fluoride (CaF2) powder having an average primary particle diameter of 4.0 μm, and magnesium fluoride (MgF2) powder having an average primary particle diameter of 3.0 μm were dispersed in a dispersion medium together with a resin binder at a ratio of YF3being 64 mol%, CaF2being 12 mol%, and MgF2being 24 mol%, whereby a raw material dispersion liquid was obtained. The resin binder was set at a ratio of 1.0 part by mass with respect to 100 parts by mass of the total powder.

[0072] Next, the raw material dispersion liquid was sprayed into a gas stream using a spray dryer, and granulated powder was produced by evaporating the dispersion medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed under conditions of N2atmosphere, 850°C for about 120 minutes, whereby granulated sintered powder was obtained. In the composition of the obtained granulated sintered powder, YF3was 50 mol%, CaF2was 25 mol%, and MgF2was 25 mol%, and did not change, and the average particle diameter of the particles classified using a sieve and an air current was 30 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 3.

[0073] <No. 4>

[0074] First, yttrium fluoride (YF3) powder having an average primary particle diameter of 2.0 μm, calcium fluoride (CaF2) powder having an average primary particle diameter of 4.0 μm, and magnesium fluoride (MgF2) powder having an average primary particle diameter of 3.0 μm were dispersed in a dispersion medium together with a resin binder at a ratio of YF3being 64 mol%, CaF2being 12 mol%, and MgF2being 24 mol%, whereby a raw material dispersion liquid was obtained. The resin binder was set at a ratio of 1.0 part by mass with respect to 100 parts by mass of the total powder.

[0075] Next, using a spray dryer, the raw material dispersion liquid was sprayed into a gas stream, and granulated powder was produced by evaporating the dispersion medium from the spray droplets. In other words, granulation was performed by a spray drying method. Next, the resulting granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed under a vacuum atmosphere at 830°C for about 180 minutes, thereby obtaining granulated sintered powder. In the composition of the resulting granulated sintered powder, YF3 was 50 mol%, CaF2 was 20 mol%, and MgF2 was 30 mol%, and did not change, and the average particle diameter of the particles classified using a sieve and an air current was 22 μm. The granulated sintered powder obtained by such an operation was set as the No. 5 sputtering material.

[0076] <No. 6>

[0077] The granulated powder obtained by granulation using a spray drying method in No. 1 was not sintered, and was directly set as the No. 6 sputtering material. The average particle diameter of the particles classified using a sieve and an air current was 32 μm.

[0078] <No. 7>

[0079] The granulated powder obtained by granulation using a spray drying method in No. 2 was introduced into a multi-atmosphere furnace, and calcination was performed under an Ar atmosphere at 850°C for about 120 minutes, thereby obtaining granulated sintered powder. In the composition of the resulting granulated sintered powder, YF3 was 64 mol%, and MgF2 was 36 mol%, and did not change, and the average particle diameter of the particles classified using a sieve and an air current was 46 μm. The granulated sintered powder obtained by such an operation was set as the No. 7 sputtering material.

[0080] <No. 8>

[0081] The granulated powder obtained by granulation using a spray drying method in No. 2 was introduced into a multi-atmosphere furnace, and calcination was performed under an Ar atmosphere at 870°C for about 120 minutes, thereby obtaining granulated sintered powder. In the composition of the resulting granulated sintered powder, YF3 was 64 mol%, and MgF2 was 36 mol%, and did not change, and the average particle diameter of the particles classified using a sieve and an air current was 52 μm. The granulated sintered powder obtained by such an operation was set as the No. 8 sputtering material.

[0082] <No. 9>

[0083] The granulated powder obtained by the granulation using the spray drying method in No. 2 was introduced into a multi-atmosphere furnace, and calcination was performed for about 120 minutes under a vacuum atmosphere at 850°C, whereby a granulated sintered powder was obtained. The composition of the obtained granulated sintered powder was not changed, with YF3 being 64 mol% and MgF2 being 36 mol%, and the average particle diameter of the particles classified using a sieve and an air current was 10 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 9.

[0084] <No. 10>

[0085] The granulated powder obtained by the granulation using the spray drying method in No. 2 was introduced into a multi-atmosphere furnace, and calcination was performed for about 120 minutes under a vacuum atmosphere at 860°C, whereby a granulated sintered powder was obtained. The composition of the obtained granulated sintered powder was not changed, with YF3 being 64 mol% and MgF2 being 36 mol%, and the average particle diameter of the particles classified using a sieve and an air current was 8 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 10.

[0086] <No. 11>

[0087] First, yttrium fluoride (YF3) powder having an average primary particle diameter of 3.0 μm, calcium fluoride (CaF2) powder having an average primary particle diameter of 0.8 μm, and magnesium fluoride (MgF2) powder having an average primary particle diameter of 4.0 μm were dispersed in a dispersing medium together with a resin binder at a ratio of YF3 being 30 mol%, CaF2 being 20 mol%, and MgF2 being 50 mol%, whereby a raw material dispersion liquid was obtained. The resin binder was set at a proportion of 2.0 parts by mass with respect to 100 parts by mass of the total powder.

[0088] Next, using a spray drier, the raw material dispersion liquid was sprayed into an air current, and a granulated powder was produced by evaporating the dispersing medium from the spray droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed for about 120 minutes under a N2 atmosphere at 800°C, whereby a granulated sintered powder was obtained. The composition of the obtained granulated sintered powder was not changed, with YF3 being 30 mol%, CaF2 being 20 mol%, and MgF2 being 50 mol%, and the average particle diameter of the particles classified using a sieve and an air current was 25 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 11.

[0089] <No. 12>

[0090] First, yttrium fluoride (YF3) powder having an average primary particle diameter of 3.0 μm and calcium fluoride (CaF2) powder having an average primary particle diameter of 2.0 μm were dispersed in a dispersing medium together with a resin binder at a ratio of 30 mol% of YF3 and 70 mol% of CaF2 to obtain a raw material dispersion liquid. The resin binder was set at a proportion of 1.0 part by mass with respect to 100 parts by mass of the total powders.

[0091] Next, using a spray dryer, the raw material dispersion liquid was sprayed into a gas stream, and granulated powder was produced by evaporating the dispersing medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed under an Ar atmosphere at 750°C for about 180 minutes, whereby granulated sintered powder was obtained. In the composition of the obtained granulated sintered powder, YF3 was 30 mol% and CaF2 was 70 mol%, and no change occurred, and the average particle diameter of the particles classified using a sieve and an air current was 48 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 12.

[0092] <No. 13>

[0093] First, yttrium fluoride (YF3) powder having an average primary particle diameter of 1.0 μm and calcium fluoride (CaF2) powder having an average primary particle diameter of 1.0 μm were dispersed in a dispersing medium together with a resin binder at a ratio of 71 mol% of YF3 and 29 mol% of CaF2 to obtain a raw material dispersion liquid. The resin binder was set at a proportion of 2.5 parts by mass with respect to 100 parts by mass of the total powders.

[0094] Next, using a spray dryer, the raw material dispersion liquid was sprayed into a gas stream, and granulated powder was produced by evaporating the dispersing medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed under a vacuum atmosphere at 900°C for about 30 minutes, whereby granulated sintered powder was obtained. In the composition of the obtained granulated sintered powder, YF3 was 71 mol% and CaF2 was 29 mol%, and no change occurred, and the average particle diameter of the particles classified using a sieve and an air current was 26 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 13.

[0095] <No. 14>

[0096] First, yttrium fluoride (YF3) powder having an average primary particle diameter of 2.0 μm and calcium fluoride (CaF2) powder having an average primary particle diameter of 2.0 μm were dispersed in a dispersing medium together with a resin binder at a ratio of 80 mol% of YF3 and 20 mol% of CaF2 to obtain a raw material dispersion liquid. The resin binder was set at a proportion of 1.5 parts by mass with respect to 100 parts by mass of the total powders.

[0097] Next, the raw material dispersion liquid was sprayed into a gas stream using a spray dryer, and granulated powder was produced by evaporating the dispersion medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed at 800°C under Ar atmosphere for about 60 minutes, whereby granulated sintered powder was obtained. The composition of the obtained granulated sintered powder was 80 mol% of YF3and 20 mol% of CaF2, and did not change, and the average particle diameter of the particles classified using a sieve and an air current was 49 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 14.

[0098] <No. 15>

[0099] First, a yttrium fluoride (YF3) powder having an average primary particle diameter of 5.0 μm and a calcium fluoride (CaF2) powder having an average primary particle diameter of 1.0 μm were dispersed in a dispersion medium together with a resin binder at a ratio of 91 mol% of YF3and 9 mol% of CaF2, whereby a raw material dispersion liquid was obtained. The resin binder was set at a proportion of 1.0 part by mass with respect to 100 parts by mass of the total powders.

[0100] Next, the raw material dispersion liquid was sprayed into a gas stream using a spray dryer, and granulated powder was produced by evaporating the dispersion medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed at 800°C under Ar atmosphere for about 60 minutes, whereby granulated sintered powder was obtained. The composition of the obtained granulated sintered powder was 80 mol% of YF3and 20 mol% of CaF2, and did not change, and the average particle diameter of the particles classified using a sieve and an air current was 49 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 14.

[0101] <No. 15>

[0102] First, a yttrium fluoride (YF3) powder having an average primary particle diameter of 5.0 μm and a calcium fluoride (CaF2) powder having an average primary particle diameter of 1.0 μm were dispersed in a dispersion medium together with a resin binder at a ratio of 91 mol% of YF3and 9 mol% of CaF2, whereby a raw material dispersion liquid was obtained. The resin binder was set at a proportion of 1.0 part by mass with respect to 100 parts by mass of the total powders.

[0103] Next, the raw material dispersion liquid was sprayed into a gas stream using a spray dryer, and granulated powder was produced by evaporating the dispersion medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed under a vacuum atmosphere at 1050°C for about 120 minutes, whereby granulated sintered powder was obtained. The composition of the obtained granulated sintered powder was 100 mol% YF3, and the average particle diameter of the particles classified using a sieve and an air current was 25 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 16.

[0104] <No. 17>

[0105] First, calcium fluoride (CaF2) powder having an average primary particle diameter of 1.0 μm was dispersed in a dispersion medium together with a resin binder, whereby a raw material dispersion liquid was obtained. The proportion of the resin binder was set to 1.5 parts by mass relative to 100 parts by mass of the powder.

[0106] Next, the raw material dispersion liquid was sprayed into a gas stream using a spray dryer, and granulated powder was produced by evaporating the dispersion medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed under a vacuum atmosphere at 1050°C for about 120 minutes, whereby granulated sintered powder was obtained. The composition of the obtained granulated sintered powder was 100 mol% YF3, and the average particle diameter of the particles classified using a sieve and an air current was 25 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 16.

[0107] <No. 17>

[0108] First, magnesium fluoride (MgF2) powder having an average primary particle diameter of 4.0 μm was dispersed in a dispersion medium together with a resin binder, whereby a raw material dispersion liquid was obtained. The proportion of the resin binder was set to 2.0 parts by mass relative to 100 parts by mass of the powder.

[0109] Next, the raw material dispersion liquid was sprayed into a gas stream using a spray dryer, and granulated powder was produced by evaporating the dispersion medium from the sprayed droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into a multi-atmosphere furnace, and calcination was performed under a vacuum atmosphere at 1050°C for about 120 minutes, whereby granulated sintered powder was obtained. The composition of the obtained granulated sintered powder was 100 mol% YF3, and the average particle diameter of the particles classified using a sieve and an air current was 25 μm. The granulated sintered powder obtained by such an operation was set as the sputtering material of No. 16.

[0110] <No. 17>

[0111] First, a yttrium fluoride (YF3) powder having an average primary particle diameter of 0.5 μm, a calcium fluoride (CaF2) powder having an average primary particle diameter of 1.0 μm, and a magnesium fluoride (MgF2) powder having an average primary particle diameter of 5.0 μm were mixed at a ratio of 50 mol% of YF3, 25 mol% of CaF2, and 25 mol% of MgF2, to obtain a mixture.

[0112] Next, the obtained mixture was introduced into a multi-atmosphere furnace, and after melting under conditions of Ar atmosphere and 1150°C for about 120 minutes, the molten block was pulverized using a jaw crusher and a grinding machine, to obtain a powder having an average particle diameter of 30 μm of the particles classified using a sieve and air flow. In the composition of the obtained powder, YF3 was 50 mol%, CaF2 was 25 mol%, and MgF2 was 25 mol%, and no change occurred. The powder obtained by such an operation was set as a sputtering material of No. 19.

[0113] <No. 20>

[0114] First, a yttrium fluoride (YF3) powder having an average particle diameter of 30.0 μm, a calcium fluoride (CaF2) powder having an average particle diameter of 30.0 μm, and a magnesium fluoride (MgF2) powder having an average particle diameter of 30.0 μm were mixed at a ratio of 50 mol% of YF3, 25 mol% of CaF2, and 25 mol% of MgF2, to obtain a mixed powder having an average particle diameter of 30.0 μm. The mixed powder obtained by such an operation was set as a sputtering material of No. 20.

[0115] <No. 21>

[0116] First, a yttrium oxide (Y2O3) powder having an average primary particle diameter of 3.0 μm was dispersed in a dispersion medium together with a resin binder, to obtain a raw material dispersion liquid. The resin binder was set at a proportion of 1.0 part by mass with respect to 100 parts by mass of the powder.

[0117] Next, using a spray dryer, the raw material dispersion liquid was sprayed into an air flow, and granulated powder was produced by evaporating the dispersion medium from the spray droplets. In other words, granulation was performed by a spray drying method. Next, the obtained granulated powder was introduced into an atmospheric calcination furnace, and calcination was performed under conditions of atmospheric air and 1600°C for about 300 minutes, to thereby obtain granulated sintered powder. In the composition of the obtained granulated sintered powder, Y2O3 was 100 mol%, and the average particle diameter of the particles classified using a sieve and air flow was 25 μm. The granulated sintered powder obtained by such an operation was set as a sputtering material of No. 21.

[0118] [Formation of Sputtered Coating Film]

[0119] The No. 1 to No. 21 sprayed materials were sprayed on a base material to form a sprayed coating film.

[0120] The spraying conditions are shown below.

[0121] First, as a base material to be sprayed, a plate (20 mm x 20 mm x 2 mm) formed of an aluminum alloy (A6061) was prepared. The sprayed surface of the base material was subjected to a sandblasting treatment using an alumina abrasive material.

[0122] The spraying was performed using a commercially available plasma spraying device (Metco (trademark) F4 Series manufactured by Oerlikon Metco) by an atmospheric pressure plasma spraying method. As for the spraying conditions, argon and hydrogen were used as plasma working gases to generate plasma, and a sprayed coating film having a thickness of 200 μm was formed.

[0123] The No. 1 to No. 21 sprayed coating films obtained by such operations were investigated for the porosity, the crystallinity, and the erosion rate by the methods shown below. The results thereof are shown in Table 1 together with the composition of each sprayed material.

[0124] (Porosity)

[0125] The calculation of the porosity was performed by the following method.

[0126] First, as for the base material on which each of the No. 1 to No. 21 sprayed coating films was formed, the cutting was performed perpendicularly to the surface on which the sprayed coating film was formed, the cut product was embedded in a resin, and after the cross section generated by the cutting was polished, a scanning electron microscope (JSM-IT300LA manufactured by JEOL) was used to take an image of the cross section of the coating film. Next, by analyzing the cross-sectional image of the coating film using an image analysis software (WinROOF2018 manufactured by Shimadzu Corporation), the area of the pore portion in the cross-sectional image of the coating film was determined, and the proportion of the area of the pore portion in the entire cross section (area %) was calculated. The calculated value was taken as the porosity. The results thereof are shown in the column of "porosity" of "sprayed coating film" in Table 1.

[0127] (Crystallinity)

[0128] Each of the No. 1 to No. 21 sprayed coating films was set on a sample holder of an X-ray diffractometer (SmartLab manufactured by Rigaku Corporation), and a diffraction pattern was obtained. Thereafter, the scattering integrated intensity of the amorphous phase and the scattering integrated intensity of the crystalline phase based on the obtained diffraction pattern were defined, and the crystallinity was calculated according to the following calculation formula. Note that the scattering integrated intensity corresponds to the area of a diffraction peak.

[0129] "Crystallinity = scattering integral intensity of crystalline phase / (scattering integral intensity of crystalline phase + scattering integral intensity of amorphous phase)"

[0130] The results thereof are shown in the column of "crystallinity" of "sputter-deposited film" of Table 1.

[0131] (Erosion rate)

[0132] After mirror-polishing each of the sputter-deposited films of No. 1 to No. 21, a silicon wafer was placed on a base provided in a chamber of an inductively coupled (ICP) plasma etching device (RIE-101iPH manufactured by SAMCO Inc.).

[0133] Next, using a mixed gas of fluorine (CF4), oxygen, and Ar (flow rate ratio: 7:1:9), plasma was generated, and the silicon wafer and the sputter-deposited film were etched. The exposure time of each plasma was set to 45 minutes.

[0134] After the plasma exposure test was performed in this way, the thickness reduction amount of the silicon wafer and the sputter-deposited film based on the plasma was measured as the etching amount (erosion amount). The plasma erosion rate of each sputter-deposited film was converted to a value when the erosion rate of the silicon wafer was set to 100. The thickness reduction amount of the silicon wafer and the sputter-deposited film was found by measuring the height difference between the central portion of the masked sample and the plasma exposure surface using a laser microscope (VK-X250 / X260 manufactured by KEYENCE CORPORATION).

[0135] [Table 1]

[0136]

[0137] From the results of Table 1, the following can be known.

[0138] In the examples of No. 1 to No. 10, the sputter-deposited material and the sputter-deposited film each satisfied "the fluoride of the rare earth element is contained at a proportion of 40 mol% or more and 80 mol% or less", "the magnesium fluoride is contained at a proportion of 10 mol% or more and 40 mol% or less", "the calcium fluoride is contained at a proportion of 0 mol% or more and 40 mol% or less", and "the fluoride of the rare earth element is yttrium fluoride".

[0139] In addition, in the examples of No. 1 to No. 10, the composite compound constituting the sputter-deposited material satisfied "it is a granulated powder of yttrium fluoride primary particles having an average particle diameter of 10 μm or less, magnesium fluoride primary particles having an average particle diameter of 10 μm or less, and calcium fluoride primary particles having an average particle diameter of 10 μm or less, or a granulated sintered powder obtained by sintering the granulated powder".

[0140] Therefore, the sprayed coating film formed by spraying the spraying materials of No. 1 to No. 10 under normal conditions becomes a sprayed coating film containing a crystalline phase and an amorphous phase, and the porosity of the sprayed coating film can be 2.1 area% or less, and the crystallinity of the sprayed coating film can be 32.7% or more and 71.5% or less. In addition, the erosion rate of the formed sprayed coating film can be 15.0% or less. In particular, in No. 1 to No. 3, No. 5, No. 6, No. 9, and No. 10, the erosion rate of the formed sprayed coating film can be 13.0% or less.

[0141] In addition, among the spraying materials of No. 1 to No. 10, the spraying materials of No. 1 to No. 6, No. 9, and No. 10 with an average particle diameter of 40 μm or less can make the porosity of the sprayed coating film 1.5 area% or less.

[0142] On the contrary, the crystallinity of the sprayed coating film formed by spraying the spraying materials of No. 11 to No. 21 under normal conditions is as high as 92.7% or more, and the erosion rate is 14.6% or more, and in particular, No. 12 to No. 18 shows a value of the porosity as high as 2.8 area% or more.

Claims

1. A spray coating material formed from a composite compound, wherein the composite compound contains rare earth fluorides in a proportion of 40 mol% to 80 mol% and magnesium fluoride in a proportion of 10 mol% to 40 mol% and contains calcium fluoride as an essential component, wherein the calcium fluoride content is 40 mol% or less, and the composite compound is a granulated sintered powder obtained by sintering granulated powders of yttrium fluoride with an average primary particle size of 10 μm or less, magnesium fluoride with an average primary particle size of 10 μm or less, and calcium fluoride with an average primary particle size of 10 μm or less, wherein the average particle size of the granulated powder is 5 μm or more and 40 μm or less.

2. A spray-plated coating formed from the spray-plating material of claim 1, comprising rare earth fluorides in a proportion of 40 mol% or more and 80 mol% or less, magnesium fluoride in a proportion of 10 mol% or more and 40 mol% or less, and calcium fluoride as an essential component, wherein the calcium fluoride content is 40 mol% or less, and the spray-plated coating comprises a crystalline phase and an amorphous phase, with a crystallinity of 1% or more and 75% or less.

3. The spray coating according to claim 2 has a porosity of less than 2.0% of area.

4. A method for forming a spray-coated film, wherein, Using the spraying material as described in claim 1, a sprayed coating as described in claim 2 or 3 is formed.

5. A component for a plasma etching apparatus, wherein the surface is covered by a spray coating as described in claim 2 or 3.

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