Member for plasma processing apparatus and method for manufacturing same

Abstract

A coating film (53) is formed on a substrate (52) of a member for a plasma processing device by using a suspension plasma thermal spray method. A suspension (63) used in suspension plasma thermal spraying contains a fluorine-containing solvent (61), a plurality of yttrium fluoride particles, and a plurality of yttrium oxyfluoride particles.

Description

Technical Field

[0001] The present invention relates to a member for a plasma processing apparatus and a method for manufacturing the same, and for example, to a member that is arranged in a processing chamber of a plasma processing apparatus and exposed to plasma and a method for manufacturing the same. Background Art

[0002] In the manufacture of semiconductor devices such as electronic devices and magnetic memories, plasma etching is used in micro-machining. The inner wall of the processing chamber of a plasma processing device that performs plasma etching is exposed to high-frequency plasma and etching gas during the etching process. Therefore, a film with excellent plasma resistance is formed on the inner wall surface of the processing chamber for protection. As a conventional technology related to materials having such a plasma-resistant film, the following technology is known.

[0003] In JP-A-2004-197181 (Patent Document 1), a film containing a group IIIA element and a fluorine element is known as a film covering the surface of a grounding portion disposed inside a plasma etching device. The film contains a group IIIA fluoride phase, which is an orthorhombic system and contains more than 50% of a crystal phase belonging to the space group Pnma.

[0004] In JP-A-2009-176787 (Patent Document 2), it is described that a film on the surface of a grounding portion arranged inside a plasma etching device is formed of any one of Al2O3, YAG, Y2O3, Gd2O3, Yb2O3, and YF3, or two or more materials. In JP-A-2016-539250 (Patent Document 3), it is described that a film on the surface of a grounding portion arranged inside a plasma etching device is formed of a material including Y3Al5O 12 , Y4Al2O9, Er2O3, Gd2O3, Y2O3, Er3Al5O 12 、Gd3Al5O 12 , any one of YF3, Nd2O3, or Y4Al2O9 and Y2O3-ZrO2 solid solution.

[0005] Japanese Patent Application Laid-Open No. 2013-140950 (Patent Document 4) describes that the material of the film on the surface of the ground portion of a plasma etching device includes yttrium fluoride and yttrium oxyfluoride.

[0006] In JP Patent Publication No. 2014-141390 (Patent Document 5), JP Patent Publication No. 2016-27624 (Patent Document 6), and JP Patent Publication No. 2018-82154 (Patent Document 7), it is described that yttrium oxide, yttrium fluoride, and yttrium fluoride oxide with an average crystallite size of less than 100 nm are used as the film material of the grounding portion disposed inside the plasma etching device, and the film is formed by an aerosol deposition method. The aerosol deposition method is also known to have the following characteristics: compared with the atmospheric plasma thermal spraying method, the surface unevenness of the formed film can be reduced.

[0007] On the other hand, Kazuhiro Ueda et al. disclosed in Japan Society of Analytical Chemistry X-ray Analysis Research Forum (ed.), Advances in X-ray Analysis 50 (April 1, 2019), pp. 197-205 (Non-patent Document 1) that increasing the average crystallite size results in more foreign matter being produced.

[0008] JP Patent Publication No. 2019-192701 (Patent Document 8) discloses that by setting the crystallite size of the film of the grounding portion disposed inside the plasma processing device to less than 50 nm, the generation of foreign matter into the semiconductor wafer being processed inside is reduced. Furthermore, it is also disclosed that by setting the temperature of the base material of the grounding portion when forming the film to within a given range, the low-temperature phase ratio can be made greater than 60% and the crystallite size can be made less than 50 nm.

[0009] JP-A-2017-190475 (Patent Document 9) discloses a specific range of the mixing ratio of yttrium fluoride granulated powder and yttrium oxide granulated powder as a thermal spray material capable of obtaining a thermal spray coating of a yttrium-based fluoride compound. The thermal spray coating of the yttrium-based fluoride compound has sufficient corrosion resistance against plasma and can effectively prevent damage to the base material caused by acid penetration during cleaning with acid.

[0010] JP-A-2017-150085 (Patent Document 10) describes a process for manufacturing a thermal spray coating made of yttrium fluoride that can suppress the generation of particles. As this process, a high-velocity flame thermal spraying method or an atmospheric pressure plasma thermal spraying method is disclosed, and a slurry containing yttrium fluoride particles having an average particle size within a specific range is supplied to a position away from the nozzle of a thermal spray gun toward the downstream side or to the front end of the nozzle.

[0011] In JP Patent Publication No. 2020-172702 (Patent Document 11), a method for forming a thermal spray coating formed on parts, components, etc. in a plasma etching device is described. It is disclosed that a thermal spray coating is formed by a suspension plasma thermal spraying method by thermal spraying a slurry in which rare earth / aluminum / monoclinic (R4Al2O9) is dispersed in a solvent. Suspension plasma thermal spraying is also called SPS (Suspension Plasma Spraying), suspension plasma thermal spraying, or suspension plasma thermal spraying.

[0012] Prior art literature

[0013] Patent Literature

[0014] Patent Document 1: Japanese Patent Application Publication No. 2004-197181

[0015] Patent Document 2: Japanese Patent Application Publication No. 2009-176787

[0016] Patent Document 3: Japanese Patent Application No. 2016-539250

[0017] Patent Document 4: Japanese Patent Application Publication No. 2013-140950

[0018] Patent Document 5: Japanese Patent Application Publication No. 2014-141390

[0019] Patent Document 6: Japanese Patent Application Publication No. 2016-27624

[0020] Patent Document 7: Japanese Patent Application Publication No. 2018-82154

[0021] Patent Document 8: JP Patent Publication No. 2019-192701

[0022] Patent Document 9: Japanese Patent Application Publication No. 2017-190475

[0023] Patent Document 10: Japanese Patent Application Publication No. 2017-150085

[0024] Patent Document 11: Japanese Patent Application Publication No. 2020-172702

[0025] Non-patent literature

[0026] Non-patent literature 1: Kazuhiro Ueda, Kazuyuki Ikenaga, Tomoyuki Tamura, Makoto Kadoya, "Study on the crystal structure and foreign matter generation mechanism of yttrium-based materials for plasma etching equipment", X-ray Analysis Research Forum of the Japanese Society of Analytical Chemistry (ed.), Advances in X-ray Analysis 50, AGNE Technology Center, published on April 1, 2019, p. 197-205 Summary of the invention

[0027] Problems to be solved by the invention

[0028] However, in the above-mentioned prior art using atmospheric plasma thermal spraying, the inventors of the present invention have found, through their studies, that problems arise because the following points are not sufficiently considered.

[0029] That is, even if the raw material used to form the film is micronized for the purpose of reducing the crystal size of the film to be formed, the raw material powder will be charged and agglomerated due to the friction between the transport gas such as dry nitrogen and the raw material powder, so the effect of micronizing the raw material cannot be fully obtained. In addition, even if a transport gas containing water is used to reduce the charge of the raw material powder, the raw material powder will agglomerate due to the adsorption force of water on the surface of the raw material powder, so the effect of micronizing the raw material cannot be fully obtained. Furthermore, due to the influence of the agglomeration of the raw material powder, a part of the raw material powder is not completely melted and is deposited in a semi-molten state. Due to this situation, it is difficult to form a thick microcrystalline layer. That is, in the above-mentioned prior art using atmospheric plasma thermal spraying, the agglomeration of the above-mentioned raw materials is not fully considered.

[0030] In order to prevent the aggregation of the raw material powder, a suspension plasma thermal spraying method using a suspension in which the raw material is dispersed in a solvent is effective.

[0031] In the suspension plasma thermal spraying of Patent Document 11, a method of suspending an oxide raw material in a solvent is disclosed. In the suspension plasma thermal spraying method using a suspension in which the raw material is dispersed in an organic solvent such as water or ethanol, since the solvent in the suspension functions as a heat-activated solution that reacts with the raw material powder, more energy is generated than in the atmospheric plasma thermal spraying method. Therefore, in the suspension plasma thermal spraying method, since the raw material powder is completely melted and deposited, a thick microcrystalline layer can be formed compared to the atmospheric plasma thermal spraying method.

[0032] However, in the suspension plasma thermal spraying method using a suspension in which a raw material is dispersed in a solvent, the inventors' studies revealed that when a fluoride or an oxyfluoride is used as a raw material, the following problems arise.

[0033] That is, in the process of forming a film based on the suspended plasma thermal spraying method, the raw material powder containing fluoride and fluoride oxide is thermally decomposed and reacts with oxygen generated from the solvent and oxygen in the atmosphere to generate oxides. As a result, yttrium oxide is mixed into the formed film. When such a film is used in a plasma etching device, the film is exposed to the fluorine plasma used during the etching process, whereby the yttrium oxide part in the film reacts with the fluorine plasma and changes into fluoride. At this time, the volume of the yttrium oxide part expands, thereby generating cracks on the surface of the film. As a result, tiny particles are scattered from the film as foreign matter. If the scattered tiny particles are attached to the processed object such as a semiconductor wafer as foreign matter, the plasma treatment of the processed object will no longer be performed normally. As a result, the yield of the plasma treatment of the processed object is reduced. In the above-mentioned prior art, the conditions for forming a thermal spray film that can fully suppress the generation of the above-mentioned tiny particles have not been fully considered.

[0034] The main object of the present application is to reduce the generation of foreign matter from components used in a plasma processing device. Other problems and new features will become apparent from the description of this specification and the accompanying drawings.

[0035] Means for solving problems

[0036] The outline of a typical embodiment among the embodiments disclosed in the present application will be briefly described as follows.

[0037] In a method for manufacturing a plasma processing device component according to one embodiment, a coating is formed on a substrate of the plasma processing device component using a suspension plasma thermal spraying method. The suspension used in the suspension plasma thermal spraying includes a fluorine-containing solvent, a plurality of yttrium fluoride particles, and a plurality of yttrium oxyfluoride particles.

[0038] Effects of the Invention

[0039] According to one embodiment, generation of foreign matter from a film on a surface of a member disposed in a processing chamber of a plasma processing apparatus can be reduced, and the life of the film can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a longitudinal sectional view showing a schematic structure of a plasma processing apparatus in one embodiment.

[0041] Figure 2 It is an explanatory diagram of a method for forming a film in one embodiment.

[0042] Figure 3 This is a SEM image of a cross section of the film.

[0043] Figure 4 This is a SEM image of a cross section of the film.

[0044] Figure 5 This is a SEM image of a cross section of the film. DETAILED DESCRIPTION

[0045] Hereinafter, the embodiments are described in detail based on the accompanying drawings. In addition, in all the drawings used to illustrate the embodiments, the same reference numerals are used to mark the components having the same functions, and their repeated descriptions are omitted. In addition, in the following embodiments, the description of the same or identical parts is not repeated in principle except when it is particularly necessary.

[0046] (Implementation Method 1)

[0047] <Structure of Plasma Processing Device>

[0048] Below, use Figure 1 The plasma processing apparatus 1 in this embodiment will be described. Figure 1 It is a longitudinal sectional view showing a schematic structure of a plasma processing apparatus 1 in this embodiment.

[0049] like Figure 1 As shown, the plasma processing apparatus 1 includes a vacuum container 2. The processing chamber 3 is a space inside the vacuum container 2. The processing chamber 3 is surrounded by the inner wall of the vacuum container 2. The upper part of the processing chamber 3 is a space surrounded by the inner wall of the cylindrical shape, and constitutes a discharge chamber (plasma generation chamber) for forming plasma 4.

[0050] Below the discharge chamber where the plasma 4 is formed, a stage 5 as a sample stage is arranged in the processing chamber 3. A wafer 6 as a processed object is arranged on the upper surface of the stage 5 and held. The stage 5 is a member having a cylindrical shape. The central axis of the stage 5 and the central axis of the discharge chamber are arranged on the same axis or at a position that is approximately considered to be on the same axis.

[0051] An exhaust port 7 is formed at the bottom of the vacuum container 2. The upper surface of the bottom of the vacuum container 2 constitutes the bottom surface of the processing chamber 3. The exhaust port 7 is arranged below the stage 5. The central axis of the exhaust port 7 in the vertical direction and the central axis of the stage 5 in the vertical direction are arranged on the same axis or at a position that is approximately considered to be on the same axis.

[0052] A space 8 is arranged between the bottom surface of the processing chamber 3 where the exhaust port 7 is formed and the lower surface of the stage 5. The space 8 constitutes the lower part of the processing chamber 3. In the up-down direction of the processing chamber 3, the stage 5 is held at a position in the middle between the upper end surface and the lower end surface of the processing chamber 3. In the processing chamber 3, a ring-shaped exhaust plate 9 is arranged to surround the stage 5. A plurality of through holes (not shown) are formed in the exhaust plate 9. The plurality of through holes connect the space above the exhaust plate 9 in the processing chamber 3 and the space 8 below the exhaust plate 9. The space 8 below the stage 5 is connected to the discharge chamber via the plurality of through holes of the exhaust plate 9 and the gap between the side wall of the stage 5 and the cylindrical inner wall of the processing chamber 3. During the processing of the wafer 6 on the stage 5, the products generated on the upper surface of the wafer 6 and the discharge chamber, the plasma in the discharge chamber, and the gas particles are discharged from the exhaust port 7 to the outside of the processing chamber 3 through the space 8. Therefore, the space 8 constitutes an exhaust path.

[0053] Although the detailed structure of the stage 5 is omitted in the figure, the stage 5 has: a cylindrical metal member, i.e., a substrate; a dielectric film arranged to cover the upper surface of the substrate; a heater arranged inside the dielectric film; and a coolant flow path arranged inside the substrate. In the stage 5, the coolant flow paths are arranged in multiple concentric or spiral shapes around the central axis of the stage 5. Furthermore, in a state where the wafer 6 is arranged on the upper surface of the dielectric film of the stage 5, a heat-conductive gas such as helium (He) gas is supplied to the gap between the lower surface of the wafer 6 and the upper surface of the dielectric film. Therefore, a pipe through which a heat-conductive gas flows is arranged inside the substrate and the dielectric film in the stage 5.

[0054] The substrate of the stage 5 is connected to a high-frequency power supply 11 via an impedance matching box 12 and a coaxial cable. The high-frequency power supply 11 supplies high-frequency power to the substrate of the stage 5 during the processing of the wafer 6 by the plasma 4. The high-frequency power forms an electric field above the upper surface of the wafer 6 for attracting charged particles in the plasma 4.

[0055] In addition, an electrode for electrostatic attraction is arranged above the heater in the dielectric film on the substrate in the stage 5. By supplying DC power to the electrode, an electrostatic force for attracting and holding the wafer 6 on the upper surface of the dielectric film is generated inside the dielectric film and the wafer 6.

[0056] A window member 13 is arranged above the upper surface of the stage 5 so as to be opposed to the stage 5. The window member 13 contains a dielectric such as quartz or ceramic and has a disc shape. The window member 13 constitutes the upper part of the vacuum container 2 and hermetically seals the processing chamber 3. Furthermore, a shower plate 14 is arranged at a position constituting the top plate surface of the processing chamber 3 below the window member 13. The shower plate 14 contains a dielectric such as quartz and has a disc shape. A plurality of through holes 15 are formed in the central portion of the shower plate 14. The shower plate 14 is arranged so that a gap (space) 16 is formed between the lower surface of the window member 13 and the shower plate 14. The window member 13 or the shower plate 14 constitutes the top plate of the processing chamber 3.

[0057] The processing gas supply pipe 17 is connected to the vacuum container 2 so as to communicate with the gap 16. A valve 18 for opening or closing the inside of the processing gas supply pipe 17 is arranged at a given position on the processing gas supply pipe 17. The processing gas (processing gas) to be supplied to the processing chamber 3 flows into the gap 16 through the processing gas supply pipe 17 opened by the valve 18, diffuses in the gap 16, and is supplied to the processing chamber 3 from the multiple through holes 15 of the shower plate 14. Therefore, the processing gas is supplied from the top to the processing chamber 3. The flow rate or speed of the processing gas is adjusted by a gas flow control unit (not shown) connected to one end side of the processing gas supply pipe 17.

[0058] A vacuum exhaust section for exhausting the gas and particles in the processing chamber 3 through the exhaust port 7 is arranged below the vacuum container 2. The vacuum exhaust section includes: a pressure adjustment plate 21; and a turbomolecular pump 22 as a vacuum pump. The pressure adjustment plate 21 is a disc-shaped valve. The pressure adjustment plate 21 moves up and down above the exhaust port 7 to increase or decrease the area of ​​the flow path for the gas to flow into the exhaust port 7. Furthermore, in the vacuum exhaust section, the outlet of the turbomolecular pump 22 is connected to a dry pump 23 as a roughing pump via an exhaust pipe. A valve 24 is arranged on the exhaust pipe.

[0059] The pressure adjustment plate 21 also has a valve function for opening and closing the exhaust port 7. A pressure detector 25, which is a sensor for detecting the pressure in the processing chamber 3, is provided in the vacuum container 2. A signal output from the pressure detector 25 is sent to a control unit (not shown) to detect the pressure value. According to the detected pressure value, the pressure adjustment plate 21 is driven based on a command signal output from the control unit. As a result, the position of the pressure adjustment plate 21 in the vertical direction changes, thereby increasing or decreasing the area of ​​the flow path for the gas to flow into the exhaust port 7.

[0060] The dry pump 23 is connected to the vacuum container 2 via an exhaust pipe 27. A valve 28 and a valve 29 are connected to the exhaust pipe 27. The valve 28 is a slow exhaust valve for slowly exhausting the processing chamber 3 from atmospheric pressure to vacuum by the dry pump 23. The valve 29 is a main exhaust valve for exhausting the processing chamber 3 at high speed by the dry pump 23.

[0061] A plasma forming unit is disposed above the cylindrical portion of the upper part of the vacuum container 2 and around the side wall surrounding the cylindrical portion. The plasma forming unit is a structure for forming an electric field or a magnetic field supplied to the processing chamber 3 in order to generate plasma 4. The plasma forming unit includes a waveguide 31, a magnetron oscillator 32, a solenoid coil 33, and a solenoid coil 34.

[0062] That is, a waveguide 31 is arranged above the window member 13. A magnetron oscillator 32 that oscillates and outputs an electric field of microwaves is arranged at one end of the waveguide 31. The waveguide 31 is a pipeline through which the electric field of the microwaves output by the magnetron oscillator 32 is propagated. The electric field of the microwaves propagated in the waveguide 31 is supplied to the processing chamber 3. The waveguide 31 comprises: a square waveguide portion 31a extending in the horizontal direction; and a circular waveguide portion 31b extending in the vertical direction. The longitudinal section of the square waveguide portion 31a has a rectangular shape. A magnetron oscillator 32 is arranged at one end of the square waveguide portion 31a. A circular waveguide portion 31b is connected to the other end of the square waveguide portion 31a. The cross section of the circular waveguide portion 31b has a circular shape, and the central axis extends in the vertical direction. A cavity portion 31c having a cylindrical shape that expands radially is arranged at the lower end of the circular waveguide portion 31b. Inside the cavity portion 31c, the electric field of a specific mode is strengthened. Multi-stage solenoid coils 33 and 34 as magnetic field generating units are arranged above and around the cavity portion 31 c and around the sides of the processing chamber 3 .

[0063] <Operation of Plasma Processing Device>

[0064] Next, the operation of the plasma processing apparatus 1 will be described.

[0065] The wafer 6 as the object to be processed is transported in a transport chamber inside a vacuum transport container (not shown) connected to the side wall of the vacuum container 2, and transported into the processing chamber 3 of the vacuum container 2 of the plasma processing device 1. Specifically, the wafer 6 is loaded on the front end of an arm of a vacuum transport device (not shown) such as a robot arm disposed in the transport chamber, transported into the processing chamber 3 of the vacuum container 2, and placed on the upper surface of the stage 5.

[0066] When the arm of the vacuum transport device is withdrawn from the processing chamber 3, the interior of the processing chamber 3 is sealed, and a DC voltage is applied to the electrode for electrostatic adsorption in the dielectric film of the carrier 5. The chip 6 is held on the dielectric film of the carrier 5 by the electrostatic force generated thereby. In this state, a heat-conducting gas such as He is supplied to the gap between the chip 6 and the upper surface of the dielectric film of the carrier 5 through the pipe inside the carrier 5. A coolant whose temperature is adjusted by a coolant temperature regulator is supplied to the coolant flow path inside the carrier 5. Thus, heat transfer is promoted between the substrate of the carrier 5 whose temperature is adjusted and the chip 6, and the temperature of the chip 6 is adjusted to a temperature range suitable for plasma processing.

[0067] The processing gas whose flow rate or speed is regulated by the gas flow control unit is supplied to the processing chamber 3 through the processing gas supply pipe 17 and through the plurality of through holes 15 of the shower plate 14 from the gap 16. In addition, the interior of the processing chamber 3 is exhausted from the exhaust port 7 by the action of the turbomolecular pump 22. The pressure in the processing chamber 3 is adjusted to a pressure range suitable for plasma processing by balancing the supply of the processing gas to the processing chamber 3 and the exhaust from the exhaust port 7. In this state, the electric field of the microwave oscillating from the magnetron oscillator 32 propagates in the waveguide 31, and is radiated into the processing chamber 3 through the window member 13 and the shower plate 14. Furthermore, the magnetic field generated by the solenoid coils 33 and 34 is supplied to the processing chamber 3, and electron cyclotron resonance (ECR: Electron Cyclotron Resonance) is generated by the interaction between the magnetic field and the electric field of the microwave. As a result, the atoms or molecules of the processing gas are excited, ionized, and dissociated, thereby generating plasma 4 in the processing chamber 3.

[0068] When plasma 4 is generated, high-frequency power is supplied from high-frequency power supply 11 to the substrate of stage 5, and bias potential is formed above the upper surface of wafer 6. Thus, charged particles such as ions in plasma 4 are attracted to the upper surface of wafer 6. A structure including a film of a processing object and a mask layer on the film is formed in advance on the upper surface of wafer 6. Therefore, the film of the processing object on the upper surface of wafer 6 is etched. Since the film of the processing object exposed from the mask layer is selectively etched, the etching of the film of the processing object progresses along the shape of the mask layer. When the etching process of the film of the processing object reaches the end point, the supply of high-frequency power from high-frequency power supply 11 to stage 5 is stopped, and plasma 4 is extinguished. Thus, the etching process stops.

[0069] If the control unit determines that it is not necessary to further advance the etching process on the wafer 6, high vacuum exhaust is performed in the processing chamber 3. Furthermore, static electricity on the stage 5 is removed to release the adsorption of the wafer 6. After that, the arm of the vacuum transport device enters the processing chamber 3, transfers the processed wafer 6 to the arm, and then transports the wafer 6 out of the processing chamber 3 to the vacuum transport chamber outside the processing chamber 3 as the arm retracts.

[0070] <Ground Electrode>

[0071] The inner wall (inner wall surface) of the processing chamber 3 of the plasma processing device 1 is a surface facing the plasma 4 and exposed to the particles in the plasma 4. On the other hand, in order to stabilize the potential of the plasma 4 as a dielectric, it is necessary to configure a member in the processing chamber 3 that functions as a grounding electrode that faces the plasma 4 and is connected to the plasma 4.

[0072] In the plasma processing apparatus 1 of the present embodiment, a grounding electrode 41 is arranged in the processing chamber 3. The grounding electrode 41 has a function as an electrode for grounding. The grounding electrode 41 is a ring-shaped member. The grounding electrode 41 covers a portion of the surface of the inner wall of the processing chamber 3 surrounding the discharge chamber. The grounding electrode 41 is arranged to surround the periphery (lateral periphery) of the space above the upper surface of the carrier 5. In the up-down direction, at least a portion of the grounding electrode 41 is located at a position higher than the upper surface of the carrier 5.

[0073] The ground electrode 41 includes a base material (parent material) 42 made of a conductive material and a film 43 covering the surface of the base material 42. In the present embodiment, the base material 42 of the ground electrode 41 includes a metal such as a stainless steel alloy or an aluminum alloy. The ground electrode 41 is grounded.

[0074] When the plasma processing apparatus 1 is operated, plasma 4 is formed in the processing chamber 3 , and the ground electrode 41 is exposed to the plasma 4 . Since the ground electrode 41 has the film 43 , the film 43 of the ground electrode 41 is exposed to the plasma 4 .

[0075] Unlike the present embodiment, if the ground electrode 41 does not have a film on the surface of the substrate 42, the substrate 42 of the ground electrode 41 is exposed to the plasma 4, and there is a concern about corrosion of the substrate 42 of the ground electrode 41 and generation of foreign matter from the substrate 42. As a result, there is a concern about contamination of the wafer 6.

[0076] Therefore, in this embodiment, a film 43 containing a material having high plasma resistance is formed so as to cover the surface of the base material 42 of the ground electrode 41. By forming the film 43 covering the base material 42, it is possible to suppress damage to the base material 42 of the ground electrode 41 caused by the plasma 4 while maintaining the function of the ground electrode 41 as an electrode. As a result, it is possible to prevent the ground electrode 41 from being corroded and the ground electrode 41 from becoming a source of foreign matter, thereby suppressing contamination of the wafer 6. In addition, the film 43 may be a laminated film.

[0077] In this embodiment, the film 43 of the ground electrode 41 contains yttrium fluoride and yttrium oxyfluoride. Yttrium fluoride and yttrium oxyfluoride are excellent as film materials with high plasma resistance. Therefore, the film 43 containing yttrium fluoride and yttrium oxyfluoride has high resistance to plasma.

[0078] In the present embodiment, the film 43 of the ground electrode 41 is formed by a suspension plasma thermal spraying method. Compared with the atmospheric plasma thermal spraying method, the suspension plasma thermal spraying method has the advantage that it is difficult to cause agglomeration of raw material particles used in thermal spraying. In the present embodiment, since the film 43 containing yttrium fluoride and yttrium oxyfluoride is formed by the suspension plasma thermal spraying method, the suspension used when forming the film 43 contains yttrium fluoride particles and yttrium oxyfluoride particles.

[0079] However, according to the research of the inventors of the present invention, when a film is formed by a suspension plasma thermal spraying method using a suspension containing yttrium fluoride particles and yttrium oxyfluoride particles, yttrium oxide is easily mixed into the formed film. In a film containing yttrium fluoride, yttrium oxyfluoride and yttrium oxide, if the ratio of yttrium oxide becomes large, when the film is exposed to plasma in the processing chamber of a plasma processing device, foreign matter is easily generated from the film. Therefore, it is desirable to suppress the ratio of yttrium oxide in the film.

[0080] Therefore, in the present embodiment, a fluorine-containing solvent is used as a solvent of the suspension used when forming the film 43. That is, when the film 43 is formed by the suspension plasma thermal spraying method, a suspension containing a fluorine-containing solvent, yttrium fluoride particles, and yttrium oxyfluoride particles is used. Thus, mixing of yttrium oxide into the film 43 is suppressed, and the content of yttrium oxide in the film 43 can be suppressed. This will be described in more detail later.

[0081] On the other hand, a member containing metal such as stainless steel alloy or aluminum alloy is also used in the base material 44 of the vacuum container 2 which does not have a function of grounding. The surface of the base material 44 of the vacuum container 2 is also subjected to passivation treatment, thermal spraying, PVD, CVD, etc. to improve the corrosion resistance to plasma and reduce consumption. In this way, corrosion, metal contamination, or generation of foreign matter caused by exposure of the base material 44 of the vacuum container 2 to the plasma 4 can be suppressed.

[0082] In addition, a cylindrical cover member (not shown) containing ceramics such as yttrium oxide or quartz may be arranged inside the inner wall surface of the cylindrical substrate 44 and between the discharge chamber and the substrate 44. By arranging such a cover member between the substrate 44 and the plasma 4, the contact between the highly reactive particles in the plasma 4 and the substrate 44 and the collision between the substrate 44 and the charged particles are blocked or reduced, and the consumption of the substrate 44 can be suppressed.

[0083] <Method of forming film>

[0084] refer to Figure 2 , the method for forming the film according to this embodiment is described below. Figure 2 It is an explanatory diagram of the method of forming a film in this embodiment.

[0085] The ground electrode 41 is prepared in a state where the coating 43 is not formed. At this stage, the coating 43 is not formed on the surface of the base material 42 of the ground electrode 41, and the surface of the base material 42 of the ground electrode 41 is exposed.

[0086] Next, the surface of the substrate 42 of the ground electrode 41 is roughened by sandblasting to improve adhesion between the surface of the substrate 42 and the film 43 formed thereon. The surface roughness Ra of the substrate 42 is preferably 1 μm or more (Ra ≥ 1 μm).

[0087] Next, the surface of the base material 42 of the ground electrode 41 that has been contaminated by the sandblasting method is subjected to a degreasing cleaning process. The degreasing cleaning process can be performed by ultrasonic cleaning using an organic solvent such as acetone. The surface of the base material 42 of the ground electrode 41 that has been degreased and cleaned becomes Figure 2 The surface of the substrate 52 shown. That is, Figure 2 The illustrated substrate 52 corresponds to the substrate 42 of the ground electrode 41 .

[0088] Next, a process of forming a film 53 on the surface of the base material 52 by using a suspension plasma thermal spraying method is performed. This process will be described below. The film 53 corresponds to the film 43 of the ground electrode 41 described above.

[0089] A thermal spray material (material for thermal spraying) 61 and a solvent (dispersion solvent) 62 are placed in a stirrer (not shown) and stirred to prepare (prepare) a suspension (liquid suspension) 63 in which the thermal spray material 61 is dispersed in the solvent 62 .

[0090] The thermal spray material 61 used in the present embodiment contains a plurality of yttrium fluoride particles and a plurality of yttrium fluoride oxide particles. Here, a thermal spray material 61 containing a plurality of yttrium fluoride particles and a plurality of yttrium fluoride oxide particles is used. The thermal spray material 61 preferably does not contain yttrium oxide particles. The solvent 62 is a solvent (dispersion solvent) in which the thermal spray material 61 is dispersed. The particles constituting the thermal spray material 61 are dispersed in the solvent 62. The solvent 62 used in the present embodiment contains fluorine. Here, a Freon liquid containing CFC (chlorofluorocarbon) is used as the solvent 62.

[0091] Therefore, the suspension 61 used in the present embodiment is a suspension containing a fluorine-containing solvent, a plurality of yttrium fluoride particles, and a plurality of yttrium oxyfluoride particles.

[0092] The average crystallite size of the yttrium fluoride particles constituting the thermal spray material 61 and the average crystallite size of the yttrium fluoride particles are preferably less than 50 nm, respectively. In addition, the average particle diameter of the yttrium fluoride particles and the average particle diameter of the yttrium fluoride particles constituting the thermal spray material 61 are preferably greater than 0.05 μm, respectively. When the average particle diameter is less than 0.05 μm, the particles are charged due to the friction between the solvent and the particles, and the particles agglomerate with each other in the suspension 63. In addition, the average particle diameter of the yttrium fluoride particles and the average particle diameter of the yttrium fluoride particles constituting the thermal spray material 61 are preferably less than 50 μm, respectively. If the average particle diameter is greater than 50 μm, the particles precipitate in the solvent, and the suspension 63 no longer fully functions as a suitable suspension. In addition, the total content of the yttrium fluoride particles and the yttrium fluoride particles in the suspension 63 is preferably greater than 10% by weight and less than 70% by weight.

[0093] A high voltage 72 is applied to the nozzle 71 of the thermal spraying device, and a plasma gas 73 flows through the nozzle 71 to generate arc discharge, thereby generating a thermal spraying flame (plasma jet flame) 74. The plasma gas 73 is a gas for plasma generation, and for example, argon gas alone or nitrogen gas alone, or a mixed gas of two or more selected from argon gas, hydrogen gas, helium gas, and nitrogen gas, etc. is used, but it is not particularly limited. The thermal spraying flame 74 is a plasmatized gas jet ejected from the nozzle 71.

[0094] The suspension 63 prepared as described above is introduced into the suspension supply pipe 75, and is thrown into the thermal spraying flame 74 through the suspension supply pipe 75. The suspension 63 thrown into the thermal spraying flame 74 is heated by the thermal spraying flame 74. As a result, the solvent 62 contained in the suspension 63 is volatilized, and the thermal spraying material 61, i.e., the yttrium fluoride particles and the yttrium oxyfluoride particles contained in the suspension 63, becomes a molten state. At this time, a part of the yttrium fluoride and a part of the yttrium oxyfluoride are thermally decomposed to form yttrium ions, fluoride ions and oxygen ions. Then, when the thermally decomposed yttrium fluoride and yttrium oxyfluoride are recombined, yttrium fluoride, yttrium oxyfluoride and yttrium oxide are formed, and they are thermally sprayed onto the substrate 52.

[0095] In the suspension plasma thermal spraying method of the prior art, an organic solvent such as water (H2O) or ethanol (C2H5OH) is used as a solvent for making a suspension. In this case, when the yttrium fluoride and yttrium oxyfluoride thermally decomposed in the thermal spraying flame recombine, yttrium oxide is easily formed. This is because the environment during recombination becomes an environment where a large amount of oxygen exists due to the presence of oxygen in the atmosphere and oxygen generated by the decomposition of the solvent (water or organic solvent).

[0096] On the other hand, in the suspension plasma thermal spraying method in the present embodiment, a fluorine-containing solvent is used as the solvent 62 contained in the suspension 63, and here, a Freon liquid containing CFC is used. Therefore, in the thermal spraying flame 74, oxygen in the atmosphere, oxygen generated from yttrium oxyfluoride, fluorine generated from yttrium fluoride, fluorine generated from yttrium oxyfluoride, and fluorine generated from the solvent (Freon liquid) exist around the material melt (melt of the thermal spraying material 61). In addition, the electronegativity of fluorine is greater than the electronegativity of oxygen. Therefore, when yttrium fluoride and yttrium oxyfluoride thermally decomposed in the thermal spraying flame 74 recombine, the probability of re-forming yttrium oxyfluoride is higher than the probability of forming yttrium oxide. As a result, when yttrium fluoride and yttrium oxyfluoride thermally decomposed in the thermal spraying flame 74 recombine, the probability of forming yttrium oxide can be reduced. Therefore, when a fluorine-containing solvent (here, CFC) is used as the solvent 62 as in the present embodiment, the formation of yttrium oxide in the thermal spraying flame 74 can be suppressed, compared with the case where water or an organic solvent is used as the solvent 62 .

[0097] Molten yttrium fluoride, molten yttrium oxyfluoride, and molten yttrium oxide are thermally sprayed onto the substrate 52 and attached, and then cooled and solidified. Thus, a mixed film of yttrium fluoride crystals, yttrium oxyfluoride crystals, and yttrium oxide crystals is formed on the substrate 52. By repeating this process to stack the mixed film, a film 53 having a thickness of, for example, about 100 μm is formed. The film 53 contains a mixture of yttrium fluoride, yttrium oxyfluoride, and yttrium oxide.

[0098] The ratio of the crystal phases contained in the film 53 formed by the suspension plasma thermal spraying method of this embodiment is 3 wt% of the orthorhombic YF3 phase, 3 wt% of the hexagonal YF3 phase, 56 wt% of the orthorhombic Y5O4F7 phase, 36 wt% of the hexagonal YOF phase, and 2 wt% of the monoclinic Y2O3 phase. The crystal phase ratio is determined by semi-quantitative analysis of the intensity of X-ray diffraction using the RIR (Reference Intensity Ratio) method.

[0099] On the other hand, when the film 53 is formed by the suspension plasma thermal spraying method using water or an organic solvent as the solvent 62, the ratio of the crystal phases contained in the film 53 is 3% by weight of the orthorhombic YF3 phase, 3% by weight of the hexagonal YF3 phase, 41% by weight of the orthorhombic Y5O4F7 phase, 41% by weight of the hexagonal YOF phase, 6% by weight of the monoclinic Y2O3 phase, and 5% by weight of the cubic Y2O3 phase. According to the research of the inventors of the present invention, in the suspension plasma thermal spraying method using water or an organic solvent as the solvent 62, the yttrium oxide phase in the formed film 53 cannot be reduced to less than 5% by weight.

[0100] Therefore, it was confirmed that when the film 53 is formed by the suspension plasma thermal spraying method using Freon liquid (CFC) as the solvent 62 as in the present embodiment, the ratio of the yttrium oxide phase in the film 53 can be reduced, compared with the case where the film 53 is formed by the suspension plasma thermal spraying method using water or an organic solvent as the solvent 62.

[0101] When the film 53 is exposed to the plasma 4 in the processing chamber 3 of the plasma processing device 1, in order to suppress the generation of foreign matter from the film 53, the content of yttrium oxide in the film 53 is preferably 9 wt% or less, and more preferably 5 wt% or less. Such a content of yttrium oxide can be achieved by the method for forming the film 53 of this embodiment.

[0102] In addition, in the film 53 , it is also acceptable that the content of yttrium oxide is zero, that is, that the film 53 does not contain yttrium oxide.

[0103] Figure 3 This is a SEM image of a cross section of the film 53 when the film 53 is formed on the substrate 52 by the suspension plasma thermal spraying method using freon liquid (CFC) as the solvent 62 as in the present embodiment.

[0104] exist Figure 3In the SEM image, the pure black area is the substrate 52 and the pores 210. From the results of SEM-EDX analysis, it was confirmed that the brighter (whiter) the contrast of the SEM image, the higher the oxygen concentration, and the darker (blacker) the contrast, the higher the fluorine concentration. The bright area (white area) 209 is an area with a high oxygen concentration, which is believed to mainly contain yttrium oxide. The dark area (black area) 208 is an area with a high fluorine concentration, which is believed to mainly contain yttrium fluoride. The area 207 with brightness (color) between area 208 and area 209 is believed to mainly contain yttrium fluoride oxide based on the judgment based on oxygen concentration and fluorine concentration. In addition, from the XRD analysis of the film 53, it was confirmed that the crystallite size on the surface of the film 53 is less than 30nm. In addition, through the observation of the cross-section STEM, in the film 53 of the present embodiment, it can be determined that a microcrystalline layer is formed in the area from the surface of the film 53 to a depth of 10μm. Furthermore, considering the analysis results of XRD, it can be estimated that the thickness of the microcrystalline layer having a crystallite size of 30 nm or less is 10 μm or more.

[0105] When the film 53 is exposed to the plasma 4 in the processing chamber 3 of the plasma processing device 1, in order to suppress the generation of foreign matter from the film 53, the average size of the crystallites in the yttrium fluoride phase in the film 53 and the average size of the crystallites in the yttrium oxyfluoride phase in the film 53 are preferably 50 nm or less. Such an average size of the crystallites can be achieved by the method for forming the film 53 of the present embodiment.

[0106] Figure 4 This is a SEM image of a cross section of the film 53 when the film 53 is formed on the substrate 52 by the suspension plasma thermal spraying method using water or an organic solvent as the solvent 62. Figure 3 Compared with the SEM image, Figure 4 In the SEM image of , it can be clearly confirmed that there are many bright areas (white areas) 209 containing yttrium oxide. Figure 3 Compared with the SEM image, Figure 4 In the SEM image of , in the intermediate color region 207 , regions close to white and regions close to black are also dispersed over a wide range.

[0107] Therefore, it was also confirmed from the SEM image that, compared with the case where the film 53 is formed by the suspension plasma thermal spraying method using water or an organic solvent as the solvent 62, when the film 53 is formed by the suspension plasma thermal spraying method using a Freon liquid (CFC) as the solvent 62 as in the present embodiment, the ratio of the yttrium oxide phase in the film 53 can be reduced.

[0108] Figure 5 This is a SEM image of a cross section of the film 53 when the film 53 is formed on the base material 52 by the atmospheric plasma thermal spraying method without using a suspension.

[0109] and Figure 3 as well as Figure 4 Compare, in Figure 5 In the SEM image of , there is almost no region with high oxygen concentration (white region) in the film 53. This suggests that yttrium oxide is hardly generated. Figure 5 In the SEM image of , the remaining particle portion 211 is also observed near the surface of the film 53. Here, the remaining particle portion 211 is formed by laminating raw material particles in a semi-molten state.

[0110] When the film 53 is formed by the atmospheric plasma thermal spraying method, it is difficult to make the crystallite size near the surface of the film 53 less than 30nm due to the influence of the agglomeration of the raw material particles. In addition, it is known that the atmospheric plasma thermal spraying method deposits raw material particles in a semi-molten state during film formation. Since the remaining particle portion 211 is heated during thermal spraying, the remaining particle portion 211 contains coarse crystals formed by crystal growth inside the particles. In the atmosphere, the speed of the solid is greater than the speed of the liquid due to air resistance, so the semi-molten particles reach the substrate 52 earlier than the molten raw material. As a result, the remaining particle portion 211 is first deposited on the substrate 52, and the molten raw material is deposited thereon and microcrystallized. Therefore, the film 53 formed by the atmospheric plasma thermal spraying method has a stacked structure in which a microcrystalline layer exists on its surface and a remaining particle portion 211 exists inside it.

[0111] If the plasma etching device is operated, the film 53 disposed inside the processing chamber is gradually thinned by the reaction with the plasma gas, ion collision, etc. If the microcrystalline layer on the surface of the film 53 disappears and the residual particle portion 211 containing large microcrystals is exposed on the surface of the film 53, foreign matter is generated due to the residual particle portion 211. This time point can be judged as the life of the film 53. Therefore, reducing the residual particle portion 211 in the film 53 and thickening the microcrystalline layer on the surface of the film 53 helps to extend the life of the film 53.

[0112] In this embodiment, since the film 53 is formed by the suspension plasma thermal spraying method instead of the atmospheric plasma thermal spraying method, the generation of the residual particle portion 211 in the film 53 can be suppressed or prevented. In addition, the microcrystalline layer on the surface of the film 53 can be thickened. As a result, the life of the film 53 can be extended.

[0113] In addition, Figure 3 There is a small amount of yttrium oxide near the surface of the film 53. It is considered that this small amount of yttrium oxide will also affect the generation of foreign matter, but considering the probability, there is almost no effect. The reason is as follows.

[0114] When the plasma etching device is in operation, if a crystal larger than the size detected as a foreign matter among a large number of crystals located on the inner wall surface cracks and fragments fly, and the scattered fragments accidentally fall on the wafer, an event may occur in which a foreign matter originating from the inner wall of the processing chamber falls on the wafer. The probability of this event occurring is estimated based on the area of ​​the inner wall, the crystallite size of the inner wall material, the number of crystals, the wafer diameter, and the inner diameter of the processing chamber, and is 10. -12 ~10 -13 That is, in order to detect the generation of foreign matter from the surface of the film 53, it is necessary that Y2O3 crystals are exposed on the surface of the film 53. Figure 3 Yttrium oxide observed in the SEM image has almost no effect on the generation of foreign matter.

[0115] As described above, according to the present embodiment, a film 53 having a low content of yttrium oxide phase can be formed. In addition, a film 53 having a thick surface microcrystalline layer with an average microcrystalline size of 30 nm or less can be formed on the surface. In the processing chamber 3 of the plasma processing device 1 provided with a member having the film 53 (here, the ground electrode 41), the generation of foreign matter from the film 53 is reduced, and the life of the film 53 can be extended.

[0116] In the present embodiment, CFC (chlorofluorocarbon) is used as the solvent 62. As the solvent 62, any one of FC (fluorocarbon), HCFC (hydrochlorofluorocarbon) or HFC (hydrofluorocarbon) can also be used. Alternatively, a mixed liquid of two or more of CFC, FC, HCFC, and HFC can also be used as the solvent 62. Therefore, a Freon-based liquid can be used as the solvent 62. In these cases, it is also possible to obtain substantially the same effect as when CFC is used as the solvent 62.

[0117] In addition, in this embodiment, the case where the film 53 and the method for forming the same are applied to the film 43 of the ground electrode 41 as a member for a plasma processing device is described. The film 53 and the method for forming the same in this embodiment can also be applied to the film of a member for a plasma processing device other than the ground electrode 41. The member for a plasma processing device to which the film 53 and the method for forming the same in this embodiment are applied is arranged in the processing chamber 3 of the plasma processing device 1, and the film of the member for a plasma processing device is exposed to the plasma 4 during the operation of the plasma processing device.

[0118] (Implementation Method 2)

[0119] In the second embodiment, the film 53 is formed by the suspension plasma thermal spraying method as in the first embodiment, but the solvent 62 contained in the suspension 63 is different from that in the first embodiment. In the second embodiment, an ammonium fluoride (NH4F) aqueous solution is used as the solvent 62. In addition, the solvent 62 contains fluorine in the first embodiment and the second embodiment. Figure 2 Next, a process of forming the film 53 using the suspension plasma thermal spraying method in the second embodiment will be described.

[0120] The thermal spray material 61 and the solvent 62 are placed in a stirrer (not shown) and stirred to prepare a suspension 63. The thermal spray material 61 used in the second embodiment is the same as that in the first embodiment.

[0121] The solvent 62 used in the second embodiment is an ammonium fluoride (NH4F) aqueous solution. The concentration of the ammonium fluoride aqueous solution constituting the solvent 62 is preferably 5% by weight or more and 50% by weight or less. The reason is that when the concentration of the ammonium fluoride aqueous solution is greater than 50% by weight, it becomes difficult to prepare a suitable suspension 63 in which NH4F is precipitated with the thermal spray material 61 as a core. In addition, this is because when the concentration of the ammonium fluoride aqueous solution is less than 5% by weight, the fluorine content of the solvent 62 becomes low, and the effect of suppressing the ratio of yttrium oxide in the film 53 formed by the suspension plasma thermal spraying method is reduced.

[0122] In the second embodiment, a suspension 63 made by using the same thermal spray material 61 as in the first embodiment and a solvent 62 containing an aqueous solution of ammonium fluoride is introduced into a suspension supply pipe 75 as in the first embodiment, and is thrown into a thermal spray flame 74 through the suspension supply pipe 75. The suspension 63 thrown into the thermal spray flame 74 is heated by the thermal spray flame 74. As a result, the solvent 62 contained in the suspension 63 volatilizes, and the yttrium fluoride particles and yttrium oxyfluoride particles contained in the suspension 63 become molten. At this time, a part of the yttrium fluoride and a part of the yttrium oxyfluoride are thermally decomposed to form yttrium ions, fluoride ions, and oxygen ions. Furthermore, when the thermally decomposed yttrium fluoride and yttrium oxyfluoride recombine, yttrium fluoride, yttrium oxyfluoride, and yttrium oxide are formed, and these are thermally sprayed onto the substrate 52.

[0123] In the suspension plasma thermal spraying method in the present embodiment 2, an ammonium fluoride aqueous solution is used as the solvent 62 contained in the suspension 63. Therefore, in the thermal spraying flame 74, oxygen in the atmosphere, oxygen generated from yttrium oxyfluoride, and oxygen generated from the solvent 62 exist around the material melt (melt of the thermal spraying material 61). However, fluorine generated from yttrium fluoride, fluorine generated from yttrium oxyfluoride, and fluorine generated from ammonium fluoride constituting the solvent 62 also exist around the material melt. In addition, the electronegativity of fluorine is greater than the electronegativity of oxygen. Therefore, when yttrium fluoride and yttrium oxyfluoride thermally decomposed in the thermal spraying flame 74 recombine, the probability of re-forming yttrium oxyfluoride is higher than the probability of forming yttrium oxide. As a result, when yttrium fluoride and yttrium oxyfluoride thermally decomposed in the thermal spraying flame 74 recombine, the probability of forming yttrium oxide can be reduced. Therefore, when a fluorine-containing solvent (ammonium fluoride aqueous solution in this case) is used as the solvent 62 as in the second embodiment, the formation of yttrium oxide in the thermal spraying flame 74 can be suppressed, compared with the case where water or an organic solvent is used as the solvent 62 .

[0124] Molten yttrium fluoride, molten yttrium oxyfluoride, and molten yttrium oxide are thermally sprayed onto the substrate 52 to adhere, and then cooled and solidified. Thus, a mixed film of yttrium fluoride crystals, yttrium oxyfluoride crystals, and yttrium oxide crystals is formed on the substrate 52. By repeating this process to stack the mixed film, a film 53 having a thickness of, for example, about 100 μm is formed. The film 53 contains a mixture of yttrium fluoride, yttrium oxyfluoride, and yttrium oxide.

[0125] The ratio of the crystal phases contained in the film 53 formed by the suspension plasma thermal spraying method of the second embodiment is 2 wt% of the orthorhombic YF3 phase, 3 wt% of the hexagonal YF3 phase, 53 wt% of the orthorhombic Y5O4F7 phase, 39 wt% of the hexagonal YOF phase, and 3 wt% of the monoclinic Y2O3 phase. The crystal phase ratio is determined by the same method as in the first embodiment.

[0126] Therefore, it can be confirmed that, compared with the case where the film 53 is formed by the suspension plasma thermal spraying method using water or an organic solvent as the solvent 62, when the film 53 is formed by the suspension plasma thermal spraying method using an ammonium fluoride aqueous solution as the solvent 62 as in the present embodiment 2, the ratio of the yttrium oxide phase in the film 53 can be reduced.

[0127] In addition, when the film 53 is formed by the suspension plasma thermal spraying method using an ammonium fluoride aqueous solution as the solvent 62 as in the second embodiment, the SEM image of the cross section of the film 53 is similar to the above-mentioned Figure 3 That is, it can be confirmed that in the SEM image of the film 53 of the present embodiment 2, the amount of the bright area (white area) 209 containing yttrium oxide is similar to the above Figure 4The SEM image of the coating 53 is clearly reduced. In addition, the XRD analysis of the coating 53 also confirms that the crystallite size on the surface of the coating 53 of the second embodiment is less than 30nm. In addition, through the observation of the cross-section STEM, in the coating 53 of the second embodiment, it can be determined that a microcrystalline layer is formed in the region from the surface of the coating 53 to a depth of 10μm. In addition, if the analysis results of XRD are taken into consideration, it can be inferred that the thickness of the microcrystalline layer with a crystallite size of less than 30nm is more than 10μm.

[0128] As also described in the first embodiment, reducing the above-mentioned residual particle portion 211 in the film 53 and thickening the microcrystalline layer on the surface of the film 53 contributes to extending the life of the film 53. In the second embodiment, it is also possible to suppress or prevent the above-mentioned residual particle portion 211 from being generated in the film 53. In addition, the microcrystalline layer on the surface of the film 53 can be thickened. As a result, the life of the film 53 can be extended.

[0129] As described above, according to the second embodiment, a film 53 having a low content of yttrium oxide phase can be formed. In addition, a film 53 having a thick surface microcrystalline layer with an average microcrystalline size of 30 nm or less can be formed on the surface. In the processing chamber 3 of the plasma processing device 1 provided with a member having the film 53 (here, the ground electrode 41), the generation of foreign matter from the surface of the film 53 is reduced, and the life of the film 53 can be extended.

[0130] In the second embodiment, an ammonium fluoride aqueous solution is used as the solvent 62. Instead of using the ammonium fluoride aqueous solution, a potassium fluoride (KF) aqueous solution may be used as the solvent 62. When the potassium fluoride aqueous solution is used as the solvent 62, substantially the same effect as when the ammonium fluoride aqueous solution is used as the solvent 62 can be obtained. When the potassium fluoride aqueous solution is used as the solvent 62, the concentration of the potassium fluoride aqueous solution is preferably 5% by weight or more and 50% by weight or less, similar to the concentration range of the ammonium fluoride aqueous solution described above.

[0131] In addition, in the present embodiment 2, a sodium fluoride (NaF2) aqueous solution can also be used as the solvent 62. When it is necessary to use the aqueous solution at a concentration of less than 5% by weight, if a sodium fluoride (NaF2) aqueous solution is used, a high effect can be obtained due to the high fluorine concentration in the solvent. However, the concentration of the sodium fluoride aqueous solution is preferably less than 4% by weight. The reason is that, when the concentration of the sodium fluoride aqueous solution is greater than 4% by weight, sodium fluoride is precipitated in the suspension 63 with the thermal spray material 61 as the core.

[0132] Therefore, in the second embodiment, as the solvent 62, any one of an ammonium fluoride aqueous solution, a potassium fluoride aqueous solution, or a sodium fluoride aqueous solution, or a mixed solution of two or more of the ammonium fluoride aqueous solution, the potassium fluoride aqueous solution, and the sodium fluoride aqueous solution can be used.

[0133] As mentioned above, although this invention was specifically described based on the said embodiment, this invention is not limited to the said embodiment, Various changes can be made within the range which does not deviate from the summary.

[0134] Description of Reference Numerals

[0135] 1 Plasma treatment device

[0136] 2 Vacuum container

[0137] 3. Processing Chamber

[0138] 4 Plasma

[0139] 5. Carrier

[0140] 6 chips

[0141] 7 Exhaust port

[0142] 8. Space

[0143] 9 Exhaust plate

[0144] 11 High frequency power supply

[0145] 12 Impedance Matching Box

[0146] 13 Window components

[0147] 14 Shower Panel

[0148] 15 Through hole

[0149] 16 Gap

[0150] 17 Process gas supply piping

[0151] 18 valve

[0152] 21 Pressure adjustment plate

[0153] 22 Turbomolecular pump

[0154] 23 Dry Pump

[0155] 24 valves

[0156] 25 Pressure Detector

[0157] 27 Exhaust pipe

[0158] 28, 29 valve

[0159] 31 Waveguide

[0160] 31a Square waveguide section

[0161] 31b Circular waveguide section

[0162] 31c Cavity

[0163] 32 Magnetron Oscillator

[0164] 33, 34 Solenoid coil

[0165] 41 Grounding electrode

[0166] 42 Substrate

[0167] 43 membrane

[0168] 52 Substrate

[0169] 53 membrane

[0170] 61 Thermal spray materials

[0171] 62 solvent

[0172] 63 Suspension

[0173] 71 Nozzle

[0174] 72 High Voltage

[0175] 73 Plasma Gas

[0176] 74 Thermal spray flame.

Claims

1. A method for manufacturing a component for a plasma processing device, comprising: (a): A step of preparing a substrate used in a member for a plasma processing device; (b): a step of preparing a first suspension comprising a fluorine-containing solvent, a plurality of yttrium fluoride particles, and a plurality of yttrium oxyfluoride particles; and (c): A step of forming a film on the substrate by a suspension plasma thermal spraying method using the first suspension liquid.

2. The method for manufacturing a member for a plasma processing apparatus according to claim 1, wherein: The solvent is a freon-based liquid.

3. The method for manufacturing a member for a plasma processing apparatus according to claim 1, wherein: The solvent contains any one of CFC, FC, HCFC and HFC, or a mixed liquid containing two or more of CFC, FC, HCFC and HFC.

4. The method for manufacturing a member for a plasma processing apparatus according to claim 1, wherein: The solvent contains any one of an aqueous solution of ammonium fluoride, an aqueous solution of potassium fluoride or an aqueous solution of sodium fluoride, or a mixed solution containing two or more of the aqueous solutions of ammonium fluoride, the aqueous solution of potassium fluoride and the aqueous solution of sodium fluoride.

5. The method for manufacturing a member for a plasma processing apparatus according to claim 4, wherein: The concentration of each of the ammonium fluoride aqueous solution and the potassium fluoride aqueous solution is 5% by weight or more and 50% by weight or less.

6. The method for manufacturing a member for a plasma processing apparatus according to claim 4, wherein: The concentration of the sodium fluoride aqueous solution is 4 weight % or less.

7. The method for manufacturing a member for a plasma processing apparatus according to claim 1, wherein: An average particle diameter of the plurality of yttrium fluoride particles and an average particle diameter of the plurality of yttrium oxyfluoride particles are respectively 0.05 μm or more and 50 μm or less.

8. The method for manufacturing a member for a plasma processing apparatus according to claim 1, wherein: The plasma processing device component is arranged in a processing chamber of the plasma processing device. When the plasma processing device is operated, the film is exposed to plasma.

9. The method for manufacturing a member for a plasma processing apparatus according to claim 1, wherein: The content of yttrium oxide in the film is 9 weight % or less.

10. The method for manufacturing a member for a plasma processing apparatus according to claim 1, wherein: The content of yttrium oxide in the film is 5% by weight or less.

11. The method for manufacturing a member for a plasma processing apparatus according to claim 1, wherein: The film comprises a yttrium fluoride phase and a yttrium oxyfluoride phase, An average size of crystallites in the yttrium fluoride phase and an average size of crystallites in the yttrium oxyfluoride phase are each 50 nm or less.

12. A component for a plasma processing device, comprising: substrate; and a film formed on the substrate, The component for a plasma processing device is characterized in that: The film comprises a yttrium fluoride phase and a yttrium oxyfluoride phase, The average size of the crystallites in the yttrium fluoride phase and the average size of the crystallites in the yttrium fluoride phase are respectively less than 50 nm, The content of yttrium oxide in the film is 5% by weight or less.

13. The member for a plasma processing apparatus according to claim 12, wherein: The film is formed by a suspension plasma thermal spraying method.

14. The member for a plasma processing apparatus according to claim 12, wherein: The plasma processing device member is disposed in a processing chamber of a plasma processing device and is exposed to plasma during operation of the plasma processing device.

Images