Ceramic component and method for manufacturing the same

Abstract

This invention provides a ceramic component in which the surface of the ceramic component is left as is after firing (fired surface), and the surface roughness of the ceramic component is increased to make it difficult for fired particles to peel off from the surface, thereby suppressing particle generation. [Solution] The ceramic member 1 according to the present invention is a fired ceramic member 1 having ceramics as its main component and further containing silica, wherein the surface 1a of the ceramic member is the as-fired surface, and in a 1000 μm square region at any point on one main surface of the as-fired ceramic member, there are 21 to 160 recesses 2, the average diameter of the openings 2a is 1 μm or more and 35 μm or less, and the maximum depth 2b is 1 μm or more and 35 μm or less, and the arithmetic mean height Sa of the region is 2 μm or more and 5 μm or less.

Description

Technical Field

[0001] The present invention relates to a ceramic member and a method for manufacturing the same, and more particularly, to a ceramic member such as a gas nozzle, a plate, a ring, etc. of an etching apparatus used in a semiconductor manufacturing apparatus and a method for manufacturing the same.

Background Art

[0002] For example, as described in Patent Document 1, a ceramic member having excellent corrosion resistance is used for a gas nozzle of a plasma apparatus. This gas nozzle is formed by forming through-holes through which gas flows in a columnar ceramic sintered body. When the gas nozzle is attached to a plasma apparatus and continuously used, the inner wall surface of the through-hole of the gas nozzle is exposed to the plasmaized gas and damaged.

[0003] When the inner wall surface of the gas nozzle is damaged by the plasmaized gas, particles of the sintered body fall off from the damaged surface, and these particles adhere to the object to be plasma-treated. Even if the fallen particles do not adhere to the object but adhere to the ceramic sintered body, since the adhesive force is weak, they are detached from the surface of the ceramic sintered body again and adhere to the object. As described above, there has been a problem that particles of the sintered body fall off from the damaged surface and adhere to the object, resulting in defects in the object. Specifically, when the object is a semiconductor wafer, the particles adhering to the object may cause, for example, circuit formation defects due to protrusions (particles) in the region where circuits around the adhesion location are formed, electrical problems due to impurity diffusion from the particles, and problems such as leakage and short circuits.

[0004] To solve the problem of sintered particles falling off the damaged surface, Patent Document 1 proposes dividing the inner wall of the through hole into a first region located near the outlet, which is the exit of the through hole, and a second region located further inside than the first region, with the first and second regions being the fired surface of the ceramic sintered body, and forming the average grain size in the first region to be larger than the average grain size in the second region.

[0005] Specifically, a gas nozzle has been proposed in which the first region, which is most likely to be exposed to plasma-generated gas, is made the burnt surface of the ceramic sintered body, and the average grain size in the first region is made larger than the average grain size in the second region, thereby improving plasma resistance and reducing the shedding of particles from the sintered body. In other words, by making the surface of the ceramic component (gas nozzle) the burnt surface as it is after firing (sintering), the generation of particles during plasma exposure caused by processing distortion and fracture layers present in polished surfaces is suppressed. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 6046752 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] As described above, by leaving the surface of the ceramic member as a fired (sintered) surface (fired surface) and forming a large average crystal grain size, plasma resistance is enhanced and the shedding of particles (particles) from the fired (sintered) body is suppressed.

[0008] From the invention described in Patent Document 1, it can be inferred that a surface with an increased average grain size and irregularities is more preferable than a smooth surface for a ceramic member from the viewpoint of plasma resistance. However, Patent Document 1 does not disclose what average grain size and degree of irregularities are necessary to suppress particle generation in the aforementioned "surface with an increased average grain size and irregularities."

[0009] Furthermore, generally speaking, when using raw materials with large particle sizes, pores remain in the molded body during molding, and if fired in this state, the fired body will not become sufficiently dense. As a result, particle detachment from the fired body (sintered body) is more likely to occur. On the other hand, when using raw materials with small particle sizes, firing for a long time or at a high temperature is required for the particles to grow, causing deformation of the fired body itself, and making it impossible to obtain a high degree of dimensional accuracy in the fired body.

[0010] Thus, it is generally known that the properties of a fired body change depending on the particle size. However, in order to obtain a suitable surface with irregularities by increasing the average crystal grain size, conventional methods of controlling this by adjusting the average particle size of the raw material powder during molding and the firing conditions are insufficient to achieve the above objective.

[0011] Furthermore, if the surface of the ceramic component (fired body) is not subjected to machining such as grinding and is left in a fired surface state, it is difficult to control the surface roughness and degree of unevenness of the ceramic component afterward because no machining is performed after firing.

[0012] Therefore, in order to solve the above technical problems, the inventors diligently studied the surface properties of sintered ceramic members to find a ceramic member with enhanced plasma resistance and suppressed shedding of sintered particles. They discovered that when a specific number of recesses of a specific shape are formed on the surface of the ceramic member, and these recesses have a specific arithmetic mean height, it becomes difficult for sintered particles to peel off from the surface of the ceramic member, thereby suppressing particle generation, and thus completed the present invention.

[0013] This invention has been made in view of the above circumstances, and aims to provide a ceramic member in which the surface of the ceramic member is left as-fired (fired surface), and further increases the surface roughness of the surface of the ceramic member, thereby making it difficult for fired particles to peel off from the surface and suppressing the generation of particles. [Means for solving the problem]

[0014] The ceramic member according to the present invention, which was made to solve the aforementioned problems, is a fired ceramic member having ceramics as its main component and further containing silica, wherein the surface of the ceramic member is in the as-fired state, and in a 1000 μm square region at any point on one main surface of the as-fired state of the ceramic member, there are 21 to 160 recesses, the average diameter of the openings being 1 μm or more and 35 μm or less, and the maximum depth being 1 μm or more and 35 μm or less, and the arithmetic mean height Sa of the region is 2 μm or more and 5 μm or less.

[0015] In the ceramic member according to the present invention, the arithmetic mean height Sa of a 1000 μm square region at any point on one main surface in the as-fired state is formed to be 2 μm or more and 5 μm or less.

[0016] Generally, to manufacture dense ceramics with high plasma resistance and no extreme irregularities, raw material powders with an average particle size in the range of 0.05 μm to 20 μm are used. In this case, the arithmetic mean height Sa of the surface irregularities after firing is approximately 0.5 μm to 1 μm. On the other hand, the surface (fired surface) of the ceramic member according to the present invention has an average particle size in the same range as conventional materials, but the Sa value is greater than 0.5 μm to 1 μm, and the arithmetic mean height Sa is formed to be 2 μm to 5 μm.

[0017] Thus, when the arithmetic mean height Sa is between 2 μm and 5 μm, the area ratio of the grain boundaries susceptible to plasma corrosion on the fired surface becomes smaller than in the conventional case. As a result, the fired particles on the surface of the ceramic component are less likely to peel off than in the conventional case, and particle generation can be further suppressed.

[0018] Furthermore, within a 1000 μm square area on the surface of the ceramic member, there are 21 to 160 recesses with an average diameter of 1 μm to 35 μm and a maximum depth of 1 μm to 35 μm. This provides a stress relaxation effect, suppresses the peeling of fired particles from the surface of the ceramic member, and suppresses particle generation.

[0019] Here, the ceramics are preferably rare earth oxides. For example, yttria can be suitably used. In particular, when yttria is used as the ceramic raw material powder, since yttria has hydrofluoric acid resistance, only the silica can be dissolved due to the difference in solubility of the ceramic raw material powder and silica particles in hydrofluoric acid, and suitable recesses can be formed on the surface of the ceramic member.

[0020] Further, the manufacturing method of the ceramic member according to the present invention is the manufacturing method of the ceramic member, wherein silica powder having an average particle diameter of 40 μm or less is added to the ceramic raw material powder as an auxiliary agent in an amount of 5% by weight or more and 13% by weight or less, and after firing, a fired surface which is an arbitrary main surface is subjected to a fluorination treatment to dissolve the silica powder exposed on the one main surface, thereby forming a recess. It is more preferable that the average particle diameter of the ceramic raw material powder is 0.1 to 10 μm.

[0021] Thus, by adding silica powder having an average particle diameter of 40 μm or less as an auxiliary agent to the ceramic raw material powder in an amount of 5% by weight or more and 13% by weight or less, firing, and then subjecting a fired surface which is an arbitrary main surface to a fluorination treatment, in a region of 1000 μm square on the surface of the ceramic member, recesses having an average opening diameter of 1 μm or more and 35 μm or less and a maximum depth of 1 μm or more and 35 μm or less can be formed in a number of 21 or more and 160 or less, and the arithmetic mean height Sa of the region can be formed to be 2 μm or more and 5 μm or less.

[0022] Note that even if the silica powder is a fine powder having an average particle diameter of less than 1 μm, the silica powder aggregates at the grain boundaries of the ceramic raw material powder. Therefore, after adding silica powder having an average particle diameter of less than 1 μm as an auxiliary agent to the ceramic raw material powder in an amount of 5% by weight or more and 13% by weight or less, firing, subjecting a fired surface which is an arbitrary main surface to a fluorination treatment, and dissolving the silica powder exposed on the one main surface to form a recess, it can be manufactured.

Effects of the Invention

[0023] According to the present invention, it is possible to obtain a ceramic member in which fired body particles are difficult to peel off from the surface and generation of particles is suppressed.

Brief Description of the Drawings

[0024] [Figure 1] FIG. 1 is a conceptual diagram showing the surface of a ceramic member according to an embodiment of the present invention. [Figure 2]Figure 2 is a flowchart illustrating a method for manufacturing a ceramic member according to an embodiment of the present invention. [Modes for carrying out the invention]

[0025] Hereinafter, embodiments of the ceramic member according to the present invention will be described with reference to the drawings. Figure 1 is a conceptual diagram showing the surface of the ceramic member according to this embodiment. Figure 2 is a flowchart showing the manufacturing method of the ceramic member according to the embodiment of the present invention.

[0026] As shown in Figure 1, the ceramic member 1 according to the present invention is a member fired with ceramics as the main component, and its surface 1a is a fired surface (fired surface) that has not been subjected to machining such as polishing or grinding. Machining the surface of ceramic component 1, such as grinding, is undesirable because it generates machining distortion and a fractured layer, which can cause particle generation during plasma exposure. In other words, the fired surface, which has not undergone machining such as grinding, does not have machining distortion or a fractured layer, thus suppressing particle generation.

[0027] As shown in Figure 2, the ceramic component 2 is manufactured by adding silica particles to ceramic raw material powder, granulating and molding it (S1, S2). Subsequently, the molded body is processed to a predetermined size and shape (S3) and fired (S4). In this manufacturing process, as will be described later, silica particles are added to the ceramic raw material powder and then fired, so the silica particles are exposed on the fired surface. Then, by immersing the ceramic member (fired body) with exposed silica particles in hydrofluoric acid, the fired surface is subjected to fluorination treatment (S5). By immersing the fired body in hydrofluoric acid, the silica particles exposed on the surface dissolve, forming a predetermined shape and number of recesses 2 on the surface 1a of the fired body, thus completing the ceramic component as the final product.

[0028] Thus, when a surface that has been fired is treated with fluorine, it is preferable because, compared to machining processes such as grinding, it is less likely to cause processing distortion or a fractured layer, and it is less likely to cause particle generation during plasma exposure. In particular, when yttria is used as the ceramic raw material powder, because yttria has hydrofluoric acid corrosion resistance, only the silica can be dissolved due to the difference in solubility of the ceramic raw material powder and silica particles in hydrofluoric acid. As a result, a predetermined shape and number of suitable recesses can be formed on the surface of the ceramic member.

[0029] The recesses 2 formed on the surface that has been fluorinated after firing are such that, in a 1000 μm square area at any point on one main surface of the ceramic member, 21 to 160 recesses are formed, each having an average opening diameter of 1 μm or more and 35 μm or less, and a maximum depth of 1 μm or more and 35 μm or less.

[0030] The reason for selecting a 1000 μm square area at any point on one main surface of the ceramic component is that, when high-purity yttria raw material is sintered, the grain size becomes almost uniform throughout the sintered body unless abnormal grain growth occurs. Therefore, the observation range was chosen to avoid becoming too wide and increasing the effort required for observation, while also ensuring that the number of samples observed (N) was not too small. Furthermore, it is not strictly required that the surface be 1000 μm square. For the reasons mentioned above, even if the surface is, for example, 500 to 2000 μm square, the significance of the present invention will not be diminished as long as the number of recesses increases or decreases accordingly.

[0031] Furthermore, the average diameter of the opening 2a can be determined by observing the surface with a SEM and measuring the size of the recesses. The maximum depth 2b was determined by cleaving the ceramic member, observing the cross-section, extracting 10 arbitrary recesses, and measuring the value of the deepest part. Furthermore, the number of recesses 2 was determined by observing the surface of the ceramic member using a scanning electron microscope (SEM).

[0032] Furthermore, the average diameter of the opening 2a of the recess 2 is the average of the equivalent diameters calculated from circles set by visual observation or circles obtained by known image analysis, assuming that the shape of the opening formed on the fluorinated surface of the fired surface corresponds to a circle within the observation range described above. Furthermore, the maximum depth 2b of the recess 2 refers to the maximum depth from the fluorinated surface of the fired surface to the bottom surface of the recess 2.

[0033] Furthermore, the fired surface 1a of the ceramic member is formed such that, in a 1000 μm square region at any point on one main surface of the ceramic member, the arithmetic mean height Sa is between 2 μm and 5 μm. Here, the arithmetic mean height Sa refers to a parameter that extends the arithmetic mean height Ra (arithmetic mean height of a line) defined in ISO 25178 Surface properties (surface roughness measurement) to a surface. Furthermore, the arithmetic mean height Sa was determined by measurement using a non-contact roughness measuring instrument.

[0034] The surface 1a (fired surface) of the ceramic component 1 reflects, to some extent, the particle size distribution of the ceramic raw material powder, resulting in irregularities corresponding to the shape of the particle size of the raw material powder used. Generally, ceramic raw material powders with an average particle size of approximately 0.05 μm to 20 μm are used, and the arithmetic mean height Sa of the surface irregularities of conventional fired ceramics is approximately 0.5 μm to 1 μm. On the other hand, the surface 1a (fired surface) of the ceramic member 1 according to the present invention can be made larger than the arithmetic mean height Sa of conventional fired surfaces, which is 0.5 μm to 1 μm, by silica particles, and is formed to have an arithmetic mean height Sa of 2 μm to 5 μm.

[0035] Incidentally, when the arithmetic mean height Sa of surface 1a (fired surface) is large, the average grain size of the fired body tends to be large, and the area ratio of grain boundaries on the fired surface that are susceptible to plasma corrosion tends to be small. For this reason, the fired body particles on the surface of the ceramic member 1 are less likely to peel off, and particle generation is suppressed.

[0036] To further suppress particle generation by taking advantage of the fact that the fired particles on the surface of the ceramic member 1 described above are difficult to peel off, it is preferable that the arithmetic mean height Sa is 2 μm or more. On the other hand, if the arithmetic mean height Sa exceeds 5 μm, it is undesirable because there is a concern that large fired particles may peel off. For example, when yttria is used as the ceramic raw material, since yttria is a low-strength material, there is a concern that intragranular fracture may occur as the particles become larger, leading to concerns about peeling of the fired particles. Therefore, an arithmetic mean height Sa of 2 μm or more and 5 μm or less is preferable.

[0037] Furthermore, as described above, the recesses 2 formed by fluorinating the fired surface consist of 21 to 160 recesses, each with an average opening diameter of 1 μm to 35 μm and a maximum depth of 1 μm to 35 μm. In this way, by forming a specific number of recesses 2, i.e., at an appropriate density, the stresses such as mechanical stress and thermal stress acting on the surface of the ceramic member can be relieved, and the peeling of fired particles from the surface 1a of the ceramic member 1 can be effectively suppressed. Furthermore, the average diameter and maximum depth 2b of the opening 2a of the recess 2 can be controlled by changing the form and particle size of the silica powder added to the ceramic raw material powder.

[0038] As described above, this recess 2 is formed on the hardened surface (surface) 1a, and if the average diameter of the opening 2a of this recess 2 is less than 1 μm, the stress-relieving effect is reduced, and it is difficult to obtain a peel-inhibiting effect, which is undesirable. On the other hand, if the average diameter of the opening 2a of the recess 2 exceeds 35 μm, the flatness of the heat-treated surface (surface) 1a deteriorates, which affects the dimensional accuracy of the member and is therefore undesirable.

[0039] Furthermore, if the maximum depth 2b of the recess 2 is less than 1 μm, the stress-relieving effect is reduced, making it difficult to obtain a peel-inhibiting effect, which is undesirable. On the other hand, if the maximum depth 2b of the recess 2 exceeds 35 μm, the flatness of the burnt surface (surface) 1a deteriorates, affecting the dimensional accuracy of the member, which is also undesirable.

[0040] Furthermore, as described above, in any 1000 μm square region on one main surface of the ceramic member 1, 21 to 160 recesses 2 are formed. If more than 35 recesses 2 are formed in a 1000 μm square area, it is undesirable because it leads to a deterioration in the dimensional accuracy of the member. If fewer than 21 recesses 2 are formed in a 1000 μm square area, it is undesirable because a stress relaxation effect cannot be obtained. Furthermore, the number of recesses 2 can be adjusted as needed by changing the amount of silica powder added to the ceramic raw material powder.

[0041] As described above, in order to effectively suppress the peeling of fired particles from the surface of the ceramic member and to suppress the deterioration of the dimensional accuracy of the member, it is necessary that in a 1000 μm square area at any point on one main surface of the ceramic member, 21 to 160 recesses are formed, each having an average diameter of 1 μm or more and 35 μm or less, and a maximum depth of 1 μm or more and 35 μm or less, and furthermore, in a 1000 μm square area at any point on one main surface of the ceramic member, the arithmetic mean height Sa is 2 μm or more and 5 μm or less.

[0042] Next, a preferred method for manufacturing the ceramic member according to the present invention will be described with reference to Figure 1.

[0043] (Weighing, mixing, granulation) First, a slurry is prepared by adding 5% to 13% by weight of silica powder of a predetermined size as an auxiliary agent, for example, silica powder with an average particle size of 20 μm to 40 μm, 10% by weight of pure water as a solvent, and ceramic raw material powder with a predetermined average particle size according to the application and purpose of the ceramic component to be manufactured, and mixing them together to make a total of 100% by weight. Granulated powder is then formed using this slurry (S1).

[0044] In this invention, there are no particular restrictions on the average particle size of the ceramic raw material powder. However, as mentioned above, if the average particle size of the ceramic raw material powder is too large, there is a concern that pores will easily remain after sintering, making it difficult to obtain a dense sintered body. On the other hand, if the average particle size of the ceramic raw material powder is too small, there is a risk that the particle size after sintering will be too small, resulting in a decrease in plasma resistance. In other words, it is not desirable to use ceramic raw material powder with an average particle size that may negate the effects of the recesses in this invention. Therefore, taking these factors into consideration, the average particle size of the ceramic raw material powder is preferably in the range of 0.1 to 10 μm.

[0045] (Shaping, processing, firing) Subsequently, the obtained granulated powder is pressure-molded using a cold isostatic press (CIP) to produce a molded body (S2). This molded body is then processed to a predetermined shape and dimensions (S3). Furthermore, this molded body is fired in a known firing furnace under a predetermined atmosphere and temperature (S4). For example, it can be manufactured by firing under conditions of a hydrogen atmosphere, a firing temperature of 1750-1850°C, and a firing time of 4-6 hours.

[0046] In the process described above, after the molded body is fired, some of the silica particles are incorporated into the ceramic grain boundaries, but most remain in their particle form. Figure 1 schematically shows the remaining silica particles 3.

[0047] Next, the fired ceramic body is subjected to a fluoride treatment, that is, immersed in hydrofluoric acid, which dissolves and removes any silica particles remaining on the surface of the fired body, forming a recess 2 as the trace of the silica particles as shown in Figure 1 (S5).

[0048] The recess 2, formed by immersing in hydrofluoric acid to dissolve and remove silica particles, is smooth overall because it does not contain any fractured layers or protrusions. Therefore, the ceramic member 1 according to the present invention can obtain a synergistic effect of the particle generation suppression effect of the fired surface and the stress relaxation effect of the recess 2. Furthermore, compared to conventional fired surfaces without recesses, the ceramic member according to the present invention is superior in that it maintains a long-term particle generation suppression effect.

[0049] Here, the average diameter of the opening 2a of the recess 2, the maximum depth 2b, and the number of recesses 2 can be controlled not only by the average particle size and addition ratio of the added silica particles, but also by the temperature, concentration, and immersion time of the hydrofluoric acid. The immersion time depends on the concentration of the hydrofluoric acid, but for example, the temperature of the hydrofluoric acid can be room temperature, but preferably 10°C to 25°C. Also, a hydrofluoric acid concentration of 5% to 25% is preferably used, and the immersion time is 5 to 30 minutes.

[0050] If the concentration is less than 5%, the silica component is not completely removed, and particles are generated during the etching process, which is undesirable. On the other hand, if the hydrofluoric acid concentration is higher than 25%, it damages the ceramic base material, and the size of the recesses becomes larger than the silica diameter, which is also undesirable. Although immersion in hydrofluoric acid was given as an example of fluorination treatment, other methods, such as exposure to hydrofluoric acid vapor, may also be used to remove silica by fluorination.

[0051] While the ceramics are not particularly limited, when yttria is used as the ceramic raw material powder, yttria has hydrofluoric acid resistance, and due to the difference in solubility of the ceramic raw material powder and silica particles in hydrofluoric acid, only the silica can be dissolved. As a result, suitable recesses can be formed on the surface of the ceramic member, so it is preferable to use yttria as the ceramic raw material powder.

[0052] More preferably, a small amount of tantalum oxide is added to the yttria raw material powder to make the particle size smaller and denser after sintering. By adding tantalum to yttria, abnormal grain growth is suppressed and the sintered body becomes denser. Furthermore, tantalum oxide and silica are compatible as sintering aids, and the sintered surface is very smooth, allowing for a small arithmetic mean height Sa, while the size of the silica particles allows for the appropriate formation of depressions, thus making it easier to obtain a synergistic effect of smooth surface and stress relaxation. [Examples]

[0053] [Examples 1-6, Comparative Examples 1-5] Yttria powder with a purity of 99.9% and an average particle size of 1 μm, tantalum oxide powder with a purity of 99.9% and an average particle size of 1 μm, and silica powder with an average particle size of 0.5 to 50 μm as a silica raw material were weighed in predetermined amounts according to the proportions shown in Table 1 below, and mixed with 10% by weight of pure water to prepare a slurry. Next, the granulated powder obtained using this slurry is subjected to a cold isostatic press (CIP) at 1500 kgf / cm². 2 By pressurizing the material, molded bodies measuring 6 mm x 6 mm x 1 mm were produced, and each of these molded bodies was fired at 1800°C in a hydrogen atmosphere to obtain fired bodies. Furthermore, each of the calcined bodies was immersed in 25% hydrofluoric acid for 5 minutes to dissolve the silica exposed on the surface of each calcined body, thereby forming depressions. Through the above process, each evaluation sample was obtained.

[0054] [evaluation] The average diameter of the recesses was determined by observing the central part of one main surface of each evaluation sample using a scanning electron microscope (SEM) and measuring the size of the recesses. Specifically, the size of each recess observed in a 1000 μm square area within a 100x magnification SEM image (calculated using the formula (maximum diameter + minimum diameter) / 2)) was measured, and the average size of each recess was used to determine the average recess diameter. The maximum depth was determined by cleaving the evaluation sample, observing it from the cross-section, extracting 10 arbitrary recesses from the central part of the surface, and measuring the value of the deepest part. Furthermore, the arithmetic mean height Sa was measured using a non-contact roughness meter at the central part of the surface as described above. While the measurement results showed that the arithmetic mean height Sa in the examples ranged from 2.1 μm to 4.8 μm, due to measurement variability, the values ​​were rounded to 2 μm to 5 μm.

[0055] The amount of particles generated was determined by using the chamber of a known ICP etching apparatus and performing a 12-hour corrosion test on each evaluation sample with CF4 plasma. This was followed by three accelerated tests in which each sample was cooled after being heated to a working temperature of 200°C, thereby forcibly creating conditions for particle generation. Subsequently, the amount of particles generated was measured using a known particle counter. A particle generation count of 20 or less was considered acceptable.

[0056] [Table 1]

[0057] As is clear from Table 1, the amount of particle generation within the scope of the present invention is sufficiently suppressed, and the effects of the present invention are demonstrated. [Industrial applicability]

[0058] The ceramic component according to the present invention is suitably used as a ceramic component in semiconductor manufacturing equipment, for example, in gas nozzles, plates, rings, etc., of etching equipment. [Explanation of symbols]

[0059] 1. Ceramic component 1a Surface (baked surface) 2 recesses 2a opening 2b Maximum depth 3. Silica particles

Claims

1. A fired ceramic member having ceramics as its main component and further containing silica, wherein the surface of the ceramic member is in the as-fired state, and in a 1000 μm square region at any point on one main surface of the ceramic member in the as-fired state, A ceramic member characterized by having 21 to 160 recesses, each having an average diameter of 1 μm to 35 μm and a maximum depth of 1 μm to 35 μm, and having an arithmetic mean height Sa of the said region of 2 μm to 5 μm.

2. The ceramic member according to claim 1, characterized in that the ceramic is a rare earth oxide.

3. The ceramic member according to claim 2, characterized in that the rare earth oxide is yttria.

4. A method for manufacturing a ceramic member according to any one of claims 1 to 3, characterized in that silica powder having an average particle size of 40 μm or less is added as an auxiliary agent in an amount of 5% by weight or more and 13% by weight or less relative to the ceramic raw material powder, and then fired, and then a fired surface which is any one main surface is fluorinated, and the silica powder exposed on the main surface is dissolved to form a recess.

5. The method for manufacturing a ceramic member according to claim 4, wherein the average particle size of the ceramic raw material powder is 0.1 to 10 μm.

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