Sintered body and member for semiconductor manufacturing apparatus

Abstract

To provide a sintered body of yttrium oxyfluoride excellent in impact resistance.SOLUTION: In the sintered body, particles made of yttrium fluoride are dispersed in a matrix of yttrium oxyfluoride. In a cross section of the sintered body, a relation between an average equivalent circle diameter D of the particles made of yttrium fluoride and an average distance L between centers of mass of the particles made of yttrium fluoride satisfies 1.50≤L / D≤20.0.SELECTED DRAWING: Figure 3A

Description

Technical Field

[0001] The present invention relates to a sintered body and a member for a semiconductor manufacturing apparatus.

Background Art

[0002] In each step in semiconductor manufacturing, particularly in the steps of dry etching, plasma etching, and cleaning, fluorine-based corrosive gases, chlorine-based corrosive gases, and plasmas using these are used.

[0003] When using these corrosive gases and plasmas, the components of the semiconductor manufacturing apparatus may be corroded, and fine particles (particles) detached from the surface of the above components may adhere to the surface of the semiconductor, easily causing product defects. Therefore, for the components of the semiconductor manufacturing apparatus, it is necessary to use ceramics with high corrosion resistance to halogen-based plasmas as the bulk material.

[0004] As such a bulk material, a sintered body made of yttrium oxyfluoride (yttrium oxyfluoride) has been proposed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the sintered body described in Patent Document 1 has insufficient impact resistance and there is still room for improvement as a structural member of a semiconductor manufacturing apparatus.

[0007] In view of the above problems, an object of the present invention is to provide a sintered body of yttrium oxyfluoride having excellent impact resistance.

Means for Solving the Problems

[0008] The sintered body of the present invention for solving the above problems is a sintered body in which particles made of yttrium fluoride are dispersed in a matrix of yttrium oxyfluoride, and in the cross section of the sintered body, the relationship between the average distance L between the centers of gravity of the particles made of yttrium fluoride and the average equivalent circle diameter D of the particles made of yttrium fluoride satisfies 1.50 ≦ L / D ≦ 20.0.

[0009] Hereinafter, in this specification, particles made of yttrium fluoride are simply referred to as yttrium fluoride particles or YF 3 particles.

[0010] Due to the yttrium fluoride particles, the stress field becomes non-uniform in the matrix of yttrium oxyfluoride, and local deformation is caused around the yttrium fluoride particles. It is presumed that such deformation occurs around a large number of yttrium fluoride particles dispersed in the matrix and absorbs the energy of impact, thereby improving the impact resistance of the sintered body. According to the findings of the present inventors, by adjusting the relationship L / D between the average distance L between the centers of gravity of the particles made of yttrium fluoride and the average equivalent circle diameter D of the particles made of yttrium fluoride to 1.50 to 20.0, the impact resistance of the sintered body can be improved particularly effectively.

[0011] The relationship L / D between the average distance L between the centers of gravity of the particles made of yttrium fluoride and the average equivalent circle diameter D of the particles made of yttrium fluoride is measured as follows. The sintered body is cut, and its cross section is observed with an electron microscope (magnification: 1000 times). Using a wavelength-dispersive fluorescent X-ray analyzer, particles with a relatively low oxygen content and a relatively high fluorine content compared to the matrix region are identified as yttrium fluoride particles from the mapping of yttrium, oxygen, and fluorine.

[0012] Next, the cross-sectional photograph taken with an electron microscope (magnification: 1000 times) is binarized (if the sintered body further contains voids, multi-valued processing such as ternarization is performed), and for the plurality of yttrium fluoride particles dispersed in the matrix, the average distance between centroids L and the average equivalent circle diameter D are calculated using image processing software (ImageJ). Here, the average distance between centroids L is measured as follows. (1) For the figure with the contour of a certain yttrium fluoride particle A, calculate and obtain the centroid of the figure, and calculate the centroids of the yttrium fluoride particles A1, A2, A3, A4 ··· AN adjacent to the particle A around it respectively. Calculate and measure the distances of the line segments connecting the centroid of the yttrium fluoride particle A and the centroids of the surrounding yttrium fluoride particles A1, A2, A3, A4 ··· AN respectively, select three line segments from those with the shortest distances, and take the average value as the distance between centroids between the yttrium fluoride particle A and the surrounding yttrium fluoride particles. (2) Next, perform the same calculation as for the yttrium fluoride particle A for all the yttrium fluoride particles present on the screen, obtain the distance between centroids between each yttrium fluoride particle and the surrounding yttrium fluoride particles, and measure the average value of these distances between centroids as the average distance between centroids L.

[0013] The average equivalent circle diameter D is measured as follows. (1) For a certain yttrium fluoride particle A, calculate and measure the area of the figure with the contour of the yttrium fluoride particle A using image processing software (ImageJ), and calculate the diameter of the true circle with the same area as the calculated area as the equivalent circle diameter of the yttrium fluoride particle A. (2) Next, calculate the equivalent circle diameters of each yttrium fluoride particle in the same way as for the yttrium fluoride particle A for all the yttrium fluoride particles present on the screen, and measure the average value of these equivalent circle diameters as the average equivalent circle diameter D.

[0014] In the sintered body of the present invention, it is desirable that the average distance L between the centroids of particles composed of yttrium fluoride exceeds 2.20 μm and is 10.0 μm or less. This is because local deformation is likely to occur around the yttrium fluoride particles. In the sintered body of the present invention, it is desirable that the average equivalent circle diameter D of particles composed of yttrium fluoride is 0.10 to 5.00 μm. This is because local deformation is likely to occur around the yttrium fluoride particles. The sintered body of the present invention has voids, and it is desirable that the porosity in the cross-section of the sintered body is 2.00% or less. This is because the impact resistance of the sintered body can be improved.

[0015] The porosity in the cross-section of the sintered body is measured by binarizing (for example, it can be ternarized with different matrices of yttrium oxyfluoride, particles composed of yttrium fluoride, and voids) an electron micrograph of the cross-section of the sintered body and calculating the ratio of the total area of the voids to the total area of the image.

[0016] In addition, the member for a semiconductor manufacturing apparatus of the present invention includes the sintered body of yttrium oxyfluoride described above. The sintered body of yttrium oxyfluoride described above has high corrosion resistance against halogen and oxygen plasma. Therefore, a member for a semiconductor manufacturing apparatus excellent in corrosion resistance and impact resistance can be provided.

Brief Description of the Drawings

[0017]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0018] (Sintered Body of Yttrium Oxyfluoride) In the sintered body of yttrium oxyfluoride of the present invention, particles made of yttrium fluoride are dispersed in a matrix of yttrium oxyfluoride. As the yttrium oxyfluoride, Y 5 O 4 F 7 is desirable, and as the yttrium fluoride, YF 3 is desirable.

[0019] Hereinafter, the case including Y 5 O 4 F 7 as the yttrium oxyfluoride and YF 3 will be described as an example. In the sintered body of yttrium oxyfluoride in the present invention, since Y 5 O 4 F 7 and YF 3 are the main components, it has high corrosion resistance against halogen and oxygen plasma. Further, in the sintered body of yttrium oxyfluoride in the present invention, the relationship between the average distance L between the centers of gravity of YF 3 particles and the average equivalent circle diameter D of YF 3 particles in the cross section of the sintered body satisfies 1.50 ≦ L / D ≦ 20.0. YF 3 By adjusting the average equivalent circle diameter D of the particles and the average distance L between the centers of gravity of YF 3 particles, around the YF 3 particles, Y 5 O 4 F 7Since local deformations occurring in the matrix can be appropriately dispersed and generated, the energy of impact can be absorbed by this deformation, making it possible to improve the impact resistance.

[0020] In the sintered body of the present invention, the YF 3 The content ratio of the particles can be obtained by binarizing an electron micrograph of the cross-section of the sintered body and calculating the total area of the YF 3 particles from this binarized image. The total area of the YF 3 particles is preferably 5 to 49% with respect to the total area of this image. YF 3 When the occupied area of the particles is 5% or more, deformation is less likely to occur around the YF 3 particles. When the occupied area of the particles is 49% or less, deformation is also less likely to occur around the YF 3 particles, and the impact resistance of the sintered body decreases. 3 This is because

[0021] In the sintered body of yttrium oxyfluoride of the present invention, the average distance L between the centroids of the YF 3 particles is desirably more than 2.20 μm and 10.0 μm or less. This is because local deformation is likely to occur around the YF 3 particles.

[0022] In the sintered body of yttrium oxyfluoride of the present invention, the average equivalent circle diameter D of the YF 3 particles is desirably 0.10 to 5.00 μm. This is because local deformation is likely to occur around the YF 3 particles.

[0023] In the sintered body of the present invention, voids exist, and the porosity in the cross-section of the sintered body is desirably 2.00% or less. This is because the impact resistance of the sintered body can be improved.

[0024] (Method for manufacturing a sintered body of yttrium oxyfluoride) The sintered body of yttrium oxyfluoride of the present invention can be manufactured by the following manufacturing method. In the present invention, the raw material is Y 5 O 4 F 7 and Y.F. 3 and Y 2 O 3 and Y.F. 3 may be combined. By combining the above ingredients, 5 O 4 F 7 and Y.F. 3 It is possible to obtain yttrium oxyfluoride having the following as a main component.

[0025] In the powder of the raw material composition, Y 5 O 4 F 7 and Y.F. 3 When combining with Y 5 O 4 F 7 and Y.F. 3 The molar ratio of Y 5 O 4 F 7 :YF 3 = 100:1 to 40 is preferable. If this raw material composition is sintered, the sintered body is Y 5 O 4 F 7 YF in matrix 3 Average distance between the centers of gravity of particles L and YF 3 The relationship of the average equivalent circular diameter D of the particles can be adjusted to satisfy 1.50≦L / D≦20.0.

[0026] Also, Y 2 O 3 and Y.F. 3 When combining, the molar ratio is Y 2 O 3 :YF 3 =100:175~300 is preferred. If this raw material composition is sintered, the sintered body is Y 5 O 4 F 7 YF in matrix 3 Average distance between the centers of gravity of particles L and YF 3The relationship between the average equivalent circle diameter D of the particles can be adjusted so as to satisfy 1.50 ≤ L / D ≤ 20.0. Also, by adjusting the firing conditions, Y 5 O 4 F 7 YF in the matrix 3 The relationship between the average distance L between the centers of gravity of the particles and the average equivalent circle diameter D of the YF 3 particles can also be adjusted so as to satisfy 1.50 ≤ L / D ≤ 20.0. For example, by adjusting the firing temperature, time, and pressure conditions during firing, the value of L / D can be adjusted. Applying a high pressure during firing tends to make the value of L / D smaller than 1.50.

[0027] As the raw material of the sintered body of the present invention, it is not appropriate to use only the Y 5 O 4 F 7 powder, binder, and sintering aid added as necessary. The sintered body described as Comparative Example 2 in this specification is made using only the Y 5 O 4 F 7 powder and binder as described in Japanese Patent No. 5911036, and it is understood that sufficient impact resistance has not been obtained.

[0028] Also, in the raw material composition, in addition to the above-mentioned Y 5 O 4 F 7 、Y 2 O 3 、and fluoride such as YF 3 etc., additives such as an organic binder, lubricant, dispersion medium liquid, and molding aid may be appropriately added. The organic binder is not particularly limited, and examples thereof include polyacrylonitrile (PAN), acrylic resin, phenol resin, epoxy resin, imide resin, furan resin, and the like. The lubricant is not particularly limited, and examples thereof include polyoxyalkylene-based compounds such as polyoxyethylene alkyl ether and polyoxypropylene alkyl ether.

[0029] The dispersion medium is not particularly limited, and examples thereof include water, organic solvents such as benzene, and alcohols such as methanol. The molding aid is not particularly limited, and examples thereof include ethylene glycol, dextrin, fatty acids, fatty acid soaps, polyalcohols, and the like.

[0030] The size (average particle diameter) of the particles of the powder obtained by granulating the raw material composition is preferably, for example, 10 to 200 μm.

[0031] The process of manufacturing the sintered body of yttrium oxyfluoride will be described. The powder of the above-described raw material composition is preliminarily molded into a predetermined shape to produce a preform. The method of preliminary molding is not particularly limited, and die pressing, CIP molding, etc. can be applied.

[0032] By degreasing the obtained molded body, firing it to bond the particles together and sintering, the sintered body of yttrium oxyfluoride of the present invention can be obtained. The firing temperature and atmosphere are not particularly limited, but the atmosphere is preferably an inert atmosphere such as argon, and the firing temperature is preferably 800 to 1100 °C. Also, the pressure during firing may be normal pressure, or a hot isostatic pressing method (HIP) for sintering the particles while pressurizing the molded body, a spark plasma sintering method (SPS) for sintering the particles by mechanical pressure and pulse electric heating, etc. may be adopted.

[0033] The member for a semiconductor manufacturing apparatus of the present invention is characterized by including the above-described sintered body of yttrium oxyfluoride. The sintered body of yttrium oxyfluoride is Y 5 O 4 F 7 and YF 3 and are the main components, so it has strong corrosion resistance against halogen and oxygen plasma. Also, regarding the cross-section of the sintered body, the relationship between the average distance L between the centers of gravity of YF 3 particles and the average equivalent circle diameter D of YF 3 particles satisfies 1.50 ≦ L / D ≦ 20.0. YF 3 The average equivalent circle diameter D of the particles and YF 3 By adjusting the average distance L between the centers of gravity between the particles, YF 3 Around the particles, Y 5 O 4 F 7 Since the local deformation occurring in the matrix can be appropriately dispersed and caused, the energy of the impact can be absorbed by this deformation, and a member for a semiconductor manufacturing apparatus excellent in impact resistance can be provided.

[0034] Further, according to the member for a semiconductor manufacturing apparatus of the present invention, as the member for a semiconductor manufacturing apparatus, a sintered body of yttrium oxyfluoride is used, and the main components are Y 5 O 4 F 7 and YF 3 Therefore, it is hardly corroded by halogen-based plasma, has excellent resistance, and can be used over a long period of time.

[0035] The specific member for a semiconductor manufacturing apparatus of the present invention is not particularly limited, and examples thereof include a mounting table for semiconductor members such as wafers, an electrostatic chuck, a gas supply unit, a coolant supply unit, a transfer arm, a chamber inner wall material, an upper electrode, a shower plate, a focus ring, an edge plate, and the like.

Example

[0036] Hereinafter, examples specifically disclosing the present invention will be shown. Note that the present invention is not limited only to the following examples.

[0037] (Example 1) Y 2 O 3 36.3 parts by weight, YF 3 63.7 parts by weight (that is, the composition after the firing reaction is, in molar ratio, Y 5 O 4 F 7 :YF 3(Example 1) 3.0 parts by weight of an acrylic resin as an organic binder and 40 parts by weight of an alcohol-based solvent as a dispersion medium were mixed, and then dried and granulated at 70 °C using a spray dryer to prepare a granular raw material composition. For the obtained granular particles, particles having a particle diameter of 80 μm or more were cut (removed) for particle size adjustment. The alcohol-based solvent was 86% by weight of ethanol and 14% by weight of isopropyl alcohol. In spray drying, the granulated particles had moisture without being completely dried. It is considered that isopropyl alcohol, whose boiling point is higher than the temperature of spray drying, remained.

[0038] Next, these granulated particles were filled into a mold of φ25 mm and uniaxially formed at 6 MPa to adjust the overall shape, and then further packed in a rubber bag and CIP formed at 200 MPa.

[0039] The above-formed body was degreased at 600 °C for 2 hours in the air, and then fired at 950 °C for 2 hours in an argon atmosphere to obtain a sintered body of yttrium oxyfluoride. The obtained sintered body of yttrium oxyfluoride was in the form of a plate with a diameter of φ19 mm and a thickness of 3 mm.

[0040] (Example 2) Y 2 O 3 was 45.1 parts by weight, and YF 3 was 54.9 parts by weight (that is, the composition after the firing reaction was, in molar ratio, Y 5 O 4 F 7 :YF 3 =100:5). 3.0 parts by weight of an acrylic resin as an organic binder and 40 parts by weight of an alcohol-based solvent as a dispersion medium were mixed, and then dried and granulated at 70 °C using a spray dryer to prepare a granular raw material composition. For the obtained granular particles, particles having a particle diameter of 80 μm or more were cut (removed) for particle size adjustment.

[0041] Next, these granulated particles were filled into a mold with a diameter of φ25 mm, uniaxially formed at 6 MPa to adjust the overall shape, and then further packed in a rubber back and CIP formed at 200 MPa.

[0042] The above-formed body was degreased at 600 °C for 2 hours in the atmosphere, and then fired at 950 °C for 2 hours in an argon atmosphere to obtain a sintered body of yttrium oxyfluoride. The obtained sintered body of yttrium oxyfluoride was in the shape of a plate with a diameter of φ19 mm and a thickness of 3 mm.

[0043] (Comparative Example 1) The procedure was the same as in Example 1, but the degreased formed body was hot press fired at 21 MPa and 950 °C for 2 hours in an argon atmosphere to obtain a sintered body of yttrium oxyfluoride.

[0044] (Example 3) Y 2 O 3 46.2 parts by weight, YF 3 53.8 parts by weight (that is, the composition after the firing reaction was Y 5 O 4 F 7 :YF 3 = 100:2), 3.0 parts by weight of an acrylic resin as an organic binder, and 40 parts by weight of an alcohol-based solvent as a dispersion medium solution were mixed, and then dried and granulated at 70 °C using a spray dryer to prepare a granular raw material composition. The other procedures were the same as in Example 2 to obtain a sintered body of yttrium oxyfluoride.

[0045] (Comparative Example 2) Y 2 O 3 46.9 parts by weight, YF 3 53.1 parts by weight (that is, the composition after the firing reaction was Y 5 O 4 F 7 :YF 3 = 100:0) were mixed and fired at 700 °C for 2 hours to obtain Y 5 O 4 F 7were synthesized, and the synthesized product was pulverized to a powder form with an average particle size of 1.1 μm. 3.0 parts by weight of an acrylic resin was used as an organic binder, and 40 parts by weight of an alcohol-based solvent was used as a dispersion medium solution. After mixing, it was dried and granulated at 70 °C using a spray dryer to prepare a granular raw material composition. The others were the same as in Example 1 to obtain a sintered body of yttrium oxyfluoride. In the electron micrograph of this sintered body, very small amounts of YF 3 particles were confirmed.

[0046] For the obtained sintered bodies of Examples 1 to 3 and Comparative Examples 1 and 2, cross-sectional photographs were taken by electron microscopy under the following conditions, and from the images, the average center-to-center distance L between YF 3 particles and the average equivalent circle diameter D of YF 3 particles were measured. The measurement results are summarized in Table 1.

[0047] For Examples 1, 2 and Comparative Example 1, their imaging results are shown in the following figures. The imaging conditions of the electron microscope are as follows. Apparatus: S-4800 manufactured by Hitachi High-Tech Corporation Accelerating voltage: 15 kV Magnification: 1000 times

[0048] Figure 1A is a cross-sectional electron micrograph of the sintered body of yttrium oxyfluoride according to Comparative Example 1, and Figure 1B is an image obtained by binarizing the cross-sectional electron micrograph of Figure 1A. Figure 2A is a histogram obtained by calculating the equivalent circle diameter of the domain from the image of Figure 1B obtained by binarizing the cross-sectional electron micrograph of Figure 1A, and Figure 2B is a histogram obtained by calculating the center-to-center distance between yttrium fluoride particles from the image of Figure 1B obtained by binarizing the cross-sectional electron micrograph of Figure 1A. Figure 3A is a cross-sectional electron micrograph of the sintered body of yttrium oxyfluoride according to Example 1, and Figure 3B is an image obtained by binarizing the cross-sectional electron micrograph of Figure 3A. Figure 4A is a histogram obtained by calculating the equivalent circle diameter of domains from the image of FIG. 3B obtained by binarizing the cross-sectional electron micrograph of FIG. 3A, and FIG. 4B is a histogram obtained by calculating the distance between the centers of gravity between yttrium fluoride particles from the image of FIG. 3B obtained by binarizing the cross-sectional electron micrograph of FIG. 4A. FIG. 5A is a cross-sectional electron micrograph of a sintered body of yttrium oxyfluoride according to Example 2, and FIG. 5B is an image obtained by binarizing the cross-sectional electron micrograph of FIG. 5A. Figure 6A is a histogram obtained by calculating the equivalent circle diameter of domains from the image of FIG. 5B obtained by binarizing the cross-sectional electron micrograph of FIG. 5A, and FIG. 6B is a histogram obtained by calculating the distance between the centers of gravity between yttrium fluoride particles from the image of FIG. 5B obtained by binarizing the cross-sectional electron micrograph of FIG. 5A.

[0049] YF 3 The average distance L between the centers of gravity between particles, YF 3 The average equivalent circle diameter D of the particles was determined from the images obtained by binarizing the cross-sectional electron micrographs such as FIG. 1B, FIG. 3B, and FIG. 5B among the above images. In addition, the image obtained by binarizing the cross-sectional electron micrograph was binarized with the matrix of yttrium oxyfluoride, the particles composed of yttrium fluoride, and the voids being different from each other, and the porosity was determined from this image.

[0050] In addition, for the cross-sections of the sintered bodies obtained in Examples 1 to 3 and Comparative Examples 1 and 2, elemental mapping of yttrium, fluorine, and oxygen was performed using a wavelength-dispersive fluorescent X-ray analyzer. FIG. 7 is an electron micrograph of a cross-section of a sintered body according to Example 1 and an image obtained by imaging elemental mapping images of fluorine (F), oxygen (O), and yttrium (Y) for the cross-section with a wavelength-dispersive fluorescent X-ray analyzer. As can be understood from FIG. 7, in the cross-section of the sintered body, a state in which dark gray particles are dispersed in a matrix that appears white (light gray) in the electron microscope image is confirmed. In the elemental mapping image, since O was not present in the particles that appeared dark gray and Y and F were confirmed, the region of these dark gray particles was designated as YF3 It was determined that... Regarding Examples 2 and 3 and Comparative Examples 1 and 2, since no O was present in the particles that appeared dark gray and Y and F were confirmed, the region of these dark gray particles was designated as YF. 3 It was determined that...

[0051] The elemental mapping conditions using a wavelength-dispersive fluorescent X-ray analyzer are as follows. Apparatus: JXA-8500F manufactured by JEOL Ltd. Accelerating voltage: 15.0 kV Irradiation current: 2.695×10 -8 A Magnification: 3000 times Time: 5 ms Size: X: 0.1303 μm Y: 0.1303 μm

[0052] Furthermore, powder X-ray diffraction (XRD) was performed on the sintered compacts obtained in Examples 1 to 3 and Comparative Examples 1 and 2 under the following conditions to obtain powder X-ray diffraction charts. The crystal structures of Y, 5 O, 4 F 7 were confirmed in all the charts. Also, peaks of YF were observed in the powder X-ray diffraction charts shown in FIGS. 8 and 9. 3 were observed. FIG. 8 is a powder X-ray diffraction chart of the sintered compact according to Example 1, FIG. 9 is a powder X-ray diffraction chart of the sintered compact according to Example 2, and FIG. 10 is a powder X-ray diffraction chart of the sintered compact according to Example 3. In FIGS. 8, 9, and 10, the identification of the crystal structures of Y, 5 O, 4 F 7 was performed using JCPDS card number 01-080-1124.

[0053] The measurement conditions for powder X-ray diffraction are as follows. Apparatus: SmartLab manufactured by Rigaku Corporation Voltage: 40 kV, current: 20 mA X-ray source: CuKα Scanning range: 2θ = 10 to 70° Scanning speed: 10° / min

[0054] For the sintered compacts of Examples 1 to 3 and Comparative Examples 1 and 2, the impact resistance was measured under the following conditions. The results are shown in Table 1. When there were fractures or cracks in the sintered compact, it was marked with ×, and when there was no change in appearance, it was marked with 〇.

[0055] (Impact resistance test) For the impact resistance test, a DuPont type impact tester (manufactured by TP Giken Co., Ltd.) was used. The punch had a diameter of 12.5 mm and a flat sample contact surface. A drop test was carried out with a load of 112 g and a height of 5 mm. As a representative example, a photograph after the impact resistance test of the sintered compact according to Example 1 is shown in Fig. 11, and a photograph after the impact resistance test of the sintered compact according to Comparative Example 1 is shown in Fig. 12.

[0056]

Table 1

[0057] The sintered compacts obtained in each example had an excellent impact resistance because the L / D value was within a predetermined range. On the other hand, the sintered compacts obtained in each comparative example had a poor impact resistance because the L / D value was outside the predetermined range.

Claims

1. A sintered body in which particles composed of yttrium fluoride are dispersed in a matrix of yttrium oxyfluoride, wherein the relationship between the average distance L between the centers of gravity of the particles composed of yttrium fluoride and the average equivalent circle diameter D of the particles composed of yttrium fluoride in the cross section of the sintered body is 1.50 ≤ L / D ≤ 20.0, the average distance L between the centers of gravity of the particles composed of yttrium fluoride exceeds 2.20 μm and is 10.0 μm or less, the average equivalent circle diameter D of the particles composed of yttrium fluoride is 0.10 to 5.00 μm, voids are present in the sintered body, and the porosity in the cross section of the sintered body is 2.00% or less. A sintered body characterized by this.

2. A member for a semiconductor manufacturing apparatus, comprising the sintered body according to Claim 1.

Images