Clamping fixture, method for manufacturing clamping fixture, and cleaning device

Abstract

The clamping fixture of the present invention includes: a support portion; a gripping portion located at one end of the support portion and used to grip the outer periphery of a substrate; and a base portion located at the other end of the support portion and used to support the support portion. At least the base portion comprises a ceramic primarily composed of silicon carbide. In the base portion, less carbon is present on the upper main surface than carbon is present in the portions other than the upper main surface.

Description

Technical Field

[0001] This invention relates to a clamping fixture, a method for manufacturing a clamping fixture, and a cleaning apparatus. Background Technology

[0002] In the past, in order to remove contaminants such as particles, organic pollutants, metallic impurities, and polymers after etching that adhere to semiconductor substrates, cleaning devices using prescribed cleaning solutions such as chemicals and pure water were used to clean the semiconductor substrates.

[0003] As a liquid treatment device including such a cleaning apparatus, Patent Document 1 discloses a liquid treatment device having a holding mechanism that holds the substrate horizontally and the holding mechanism having claws that hold the end face of the substrate. Furthermore, as a holding mechanism that holds the substrate horizontally, Patent Document 2 discloses a clamping member that presses the substrate from above, and describes that the clamping member is made of silicon carbide.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 5726686

[0007] Patent Document 2: Japanese Patent Application Publication No. 4-130627 Summary of the Invention

[0008] Solution for solving the problem

[0009] The clamping fixture of the present invention includes: a support portion; a gripping portion located at one end of the support portion and used to grip the outer periphery of a substrate; and a base portion located at the other end of the support portion and used to support the support portion. At least the base portion comprises a ceramic primarily composed of silicon carbide. In the base portion, less carbon is present on the upper main surface than carbon is present in the portions other than the upper main surface.

[0010] The manufacturing method of the clamping fixture of the present invention includes: a step of filling a forming mold with particles mainly composed of silicon carbide and forming it to obtain a shaped body; a step of cutting the shaped body to obtain a precursor; a step of sintering the precursor to obtain a sintered body; and a step of heat-treating the sintered body in an atmospheric atmosphere at a temperature of 300°C or higher and 750°C or lower.

[0011] Furthermore, the cleaning apparatus of the present invention includes the aforementioned clamping fixture. Attached Figure Description

[0012] Figure 1 This is a schematic diagram showing the outline structure of a cleaning apparatus equipped with a clamping fixture according to an embodiment of the present invention.

[0013] Figure 2 This is an enlarged view showing a clamping fixture according to an embodiment of the present invention. Detailed Implementation

[0014] As described above, conventional wiring boards, when repeatedly cleaned with fluorine-containing acids such as hydrofluoric acid or hypofluorite over a prolonged period, will have fluorine bonded to the carbon on the surface of the clamping fixture, causing it to whiten. Therefore, there is a need for a clamping fixture that will not cause whitening on the surface even when repeatedly cleaned with fluorine-containing acids such as hydrofluoric acid or hypofluorite over a prolonged period.

[0015] As described above, the clamping fixture of the present invention has less carbon on the upper main surface of the base than on the parts other than the upper main surface of the base. As a result, even when the workpiece is repeatedly cleaned with fluorine-containing acids such as hydrofluoric acid or hypofluorite over a long period, whitening is unlikely to occur on the upper main surface of the base, which is easily exposed to the fluorine-containing acid. Therefore, the clamping fixture of the present invention reduces appearance degradation and can be used for a long period.

[0016] The following is based on Figure 1 The clamping fixture of the present invention will be described in detail in section 2. Figure 1 This is a schematic diagram showing the general structure of a cleaning device 30 equipped with a clamping fixture 22 according to an embodiment of the present invention.

[0017] Figure 1 The cleaning apparatus 30 shown includes a housing 1 and a chamber 2 inside the housing 1 for cleaning various substrates W such as semiconductor wafers and liquid crystal display (LCD) substrates.

[0018] The housing 1 has a first window 3 for loading or unloading the substrate W into or out of the housing 1. The first window 3 is opened and closed by a first gate 4. A transport arm 5 carries the substrate W and loads it into or unloads it from the housing 1 through the first window 3. The first window 3 is closed by the first gate 4 except when the substrate W is being loaded or unloaded. The first gate 4 is located inside the housing 1 and opens and closes the first window 3 from inside the housing 1.

[0019] The chamber 2 has a second window 6 for loading or unloading the substrate W into or out of the chamber 2. The second window 6 is opened and closed by a second gate 7. The transport arm 5 enters or exits the chamber 2 through the second window 6 and transfers the substrate W relative to a rotating chuck 8 disposed inside the chamber 2. The second gate 7 is disposed inside the chamber 2 and opens and closes the second window 6 from inside the chamber 2.

[0020] A gas supply unit 9, which supplies drying gas such as nitrogen into chamber 2, is provided on the top plate of chamber 2. To prevent the chamber 2 from becoming filled due to evaporation of the cleaning solution (e.g., hydrofluoric acid, hypofluorite, or other fluorine-containing acids) supplied to the substrate W held in the rotating chuck 8, the gas supply unit 9 supplies drying gas downwards. When the drying gas is supplied downwards, it is difficult to generate watermarks as contaminants on the surface of the substrate W.

[0021] The chamber 2 is provided with a processing cup 10 for receiving substrate W, a rotating chuck 8 for holding substrate W in the processing cup 10, a lower plate 11 located at a position separated from the back of substrate W, and an upper plate 16 located at a position separated from the surface of substrate W.

[0022] The processing cup 10 has an inclined portion at the top and a drain pipe 10a at the bottom. The upper part of the processing cup 10, where the inclined portion is formed, is located above the substrate W held in the rotating chuck 8 (in...). Figure 1 The position is indicated by a solid line. (The following may refer to a "processing position"). The upper part is located below the substrate W held in the rotating chuck 8 (in...). Figure 1 The positions below are indicated by double-dotted lines. Some positions are marked as "retreat positions." (These positions can be moved freely up and down between these points.)

[0023] When the substrate W is transferred between the transport arm 5 and the rotary chuck 8, the processing cup 10 remains in the retracted position so as not to obstruct the entry and exit of the transport arm 5. On the other hand, when cleaning the substrate W held in the rotary chuck 8, the processing cup 10 remains in the processing position. The processing cup 10, held in the processing position, prevents the cleaning fluid supplied to the substrate W from splashing around, and guides the cleaning fluid used in cleaning the substrate W to the drain pipe 10a.

[0024] The drain pipe 10a is connected to the cleaning fluid recovery line and the exhaust pipe (neither shown). The drain pipe 10a will discharge waste such as mist generated in the treatment cup 10 or recover the cleaning fluid in the chamber 2.

[0025] The rotary chuck 8 has a circular rotating plate 12 and a cylindrical body 13 connected to the rotating plate 12. A support member (not shown) for supporting the substrate W and a clamping fixture 22 for fixing the substrate W are mounted on the outer periphery of the rotating plate 12. The support member is arranged at least at three equal intervals along the circumferential direction and supports the substrate W from the back side.

[0026] The clamping fixture 22 is arranged at least three equally spaced locations along the circumferential direction to fix the substrate W from the outer peripheral surface. A belt 14 is wound around the outer peripheral surface of the cylindrical body 13. By using the motor 15 to drive the belt 14, the cylindrical body 13 and the rotating plate 12 can be rotated, thereby rotating the substrate W fixed by the clamping fixture 22.

[0027] The lower plate 11 is connected to the central portion of the rotating plate 12 and the first shaft 24 inside the cylindrical body 13. The first shaft 24 is fixed to a horizontal plate 25, which can be raised and lowered together with the first shaft 24 via a first lifting mechanism 26 such as a cylinder. A first flow path 23 is provided on the lower plate 11 and the first shaft 24 to supply cleaning fluid and drying gas toward the substrate W.

[0028] A circular upper plate 16, located near the top plate of chamber 2, is connected to the lower end of a cylindrical second shaft 17. The upper plate 16 can be rotated by a motor 19 mounted on a horizontal plate 18. The second shaft 17 is rotatably supported on the lower surface of the second horizontal plate 18. The second horizontal plate 18 can be raised and lowered vertically using a second lifting mechanism 20, such as a cylinder fixed to the top plate of chamber 2. Both the upper plate 16 and the second shaft 17 have axially arranged second flow paths 21 for supplying cleaning fluid and drying gas.

[0029] When the substrate W is transferred between the rotating chuck 8 and the transport arm 5, the upper plate 16 is held in a position close to the top plate of the chamber 2 to avoid collision with the transport arm 5. When cleaning the surface (upper surface) of the substrate W, the upper plate 16 descends to a position close to the surface of the substrate W held in the clamping fixture 22. Cleaning fluid or the like is supplied to the substrate W through the second flow path 21.

[0030] While simultaneously cleaning the front and back surfaces (top and bottom surfaces) of substrate W, the back surface of substrate W is cleaned using the lower plate 11 and the first flow path 23, concurrently with the cleaning of the front surface. A possible method for cleaning the back surface of substrate W is as follows: First, the lower plate 11 is initially brought close to the back surface of substrate W. Next, a cleaning solution is supplied from the first flow path 23 between substrate W and the lower plate 11 to form a cleaning solution layer. The cleaning solution is maintained for a predetermined time. Next, pure water or the like is supplied from the first flow path 23 between substrate W and the lower plate 11 to allow the solution to flow out and perform a rinsing process. Then, while supplying dry gas from the first flow path 23 between substrate W and the lower plate 11, substrate W is rotated at high speed.

[0031] Cleaning solutions can include, for example, hydrofluoric acid, hypofluorite, and other acids containing fluorine.

[0032] After cleaning the substrate W, it is held in the clamping fixture 22. At this time, after the treatment cup 10 is raised, the used medicine, pure water, etc. are discharged from the drain pipe 10a.

[0033] After the substrate W is cleaned, the processing cup 10 and the lower plate 11 are lowered. With the upper plate 16 raised, the substrate W is transferred from the clamping jig 22 to the support member. Next, the first gate 4 and the second gate 7 are opened, allowing the transfer arm 5 to enter the chamber 2. In this state, by reversing the previously described step of transferring the substrate W from the transfer arm 5 to the rotary chuck 8, the substrate W is transferred from the rotary chuck 8 to the transfer arm 5, and the substrate W is removed from the cleaning device 30.

[0034] Next, a clamping fixture 22 according to one embodiment of the present invention will be described. For example... Figure 2 As shown, the clamping fixture 22 includes a support portion 22a, a holding portion 22b located at one end of the support portion 22a and used to hold the outer periphery of the substrate, and a base portion 22c located at the other end of the support portion 22a and used to support the support portion.

[0035] The support portion 22a is a component used to connect the grip portion 22b (described later) and the base portion 22c, and is made of, for example, ceramic. The type of ceramic is not limited; examples include ceramics primarily composed of silicon carbide, boron carbide, or aluminum oxide.

[0036] In this specification, "main component" means, when the main component is silicon carbide or boron carbide, that the components constituting the ceramic account for 80% or more of the total mass percentage. When the main component is aluminum oxide, it means that the components constituting the ceramic account for 99.6% or more of the total mass percentage.

[0037] When the support portion 22a is formed of a ceramic with silicon carbide as the main component, boron and free carbon may also be included as other components. When the support portion 22a is formed of a ceramic with aluminum oxide as the main component, oxides of magnesium, silicon, and calcium may also be included as other components.

[0038] The composition of the ceramic can be identified using an X-ray diffraction apparatus with CuKα lines. The content of each component can be determined, for example, by an ICP (Inductively Coupled Plasma) luminescence spectrophotometer or a fluorescence X-ray analyzer.

[0039] The gripping part 22b is a component used to grip the outer periphery of the substrate W. The gripping part 22b is located at one end of the support part 22a. The gripping part 22b is made of ceramic, for example. The type of ceramic is not limited, and examples include ceramics with silicon carbide as the main component, ceramics with boron carbide as the main component, and ceramics with aluminum oxide as the main component.

[0040] When the gripping part 22b is formed of a ceramic with silicon carbide as the main component, boron and free carbon may also be included as other components. When the gripping part 22b is formed of a ceramic with boron carbide as the main component, iron, aluminum, silicon, yttrium, etc., may also be included as other components. When the gripping part 22b is formed of a ceramic with aluminum oxide as the main component, oxides of magnesium, silicon, and calcium may also be included as other components.

[0041] exist Figure 2 Although not specifically illustrated, the gripping portion 22b is machined into a shape that facilitates gripping the outer periphery of the substrate W. Specifically, the gripping portion 22b has slits, grooves, etc.

[0042] The base 22c is located at the other end of the support portion 22a, that is, it is arranged opposite to the holding portion 22b. The base 22c is formed of ceramic with silicon carbide as the main component. In addition to silicon carbide, the ceramic forming the base 22c may also contain, for example, boron or free carbon.

[0043] In the base 22c, which is made of silicon carbide-based ceramic, the carbon present on the upper main surface 22c' is less than the carbon present on the parts other than the upper main surface 22c'. Therefore, even if the object is repeatedly cleaned with fluorine-containing acids such as hydrofluoric acid or hypofluorite over a long period of time, it is difficult for whitening to occur on the upper main surface of the base, which is easily exposed to fluorine-containing acids. That is, the bonding of fluorine, which has a relatively high covalent bonding energy with carbon, can be suppressed, thus making whitening difficult to occur. As a result, the clamping fixture of the present invention reduces the deterioration of appearance and can be used for a long period of time.

[0044] On the other hand, the carbon present on surfaces other than the upper main surface 22c', such as the lower main surface, is greater than the carbon present on the upper main surface 22c'. Therefore, the surfaces other than the upper main surface 22c' can maintain the semiconductivity inherent in silicon carbide (e.g., a surface resistivity of 10 Ω·cm). 4 ~10 11 Ω), thus it can suppress the adsorption of particles floating in space.

[0045] The upper main surface 22c' may also contain at least one of silicon oxide, silicon carbide (SiCO), and silicon oxynitride (SiCON). These compounds may also be disposed in a dispersed configuration. When the upper main surface 22c' contains silicon carbide (SiCO) or silicon oxynitride (SiCON), these compounds may also be layered. When the upper main surface 22c' contains silicon carbide (SiCO), its composition can be represented, for example, as SiC. 1-x O x (x = 0.1 or higher and 0.9 or lower).

[0046] In this specification, "upper main surface of the base" means from the surface to the depth direction ( Figure 2 The area within 0.5mm (in the direction of arrow D).

[0047] The carbon content in the upper main surface 22c' of the base 22c is not limited as long as it is less than that in the portion outside the upper main surface 22c'. To further suppress fluorine bonding and make whitening less likely, the ratio (R1) of the carbon statistical number to the silicon statistical number is preferably 0.004 or less. This ratio (R1) is the ratio of the carbon statistical number to the silicon statistical number based on elemental mapping using an electron beam microscopy analyzer.

[0048] On the other hand, the ratio R2 of the carbon count to the silicon count in the surface other than the upper main surface 22c' is 0.0045 or more, and the difference between the ratio (R1) and the ratio (R2) is preferably 0.0005 or more. The ratio R2 in the surface other than the upper main surface 22c' can be, for example, the R2 in the lower main surface of the base 22c, or the ratio R2 in the side surface of the base 22c excluding the area within 0.5 mm from the top.

[0049] Elemental mapping based on electron beam microscopy is an elemental analysis performed using an energy-dispersive X-ray analyzer (EDS). Specifically, it involves a semi-quantitative analysis using the ZAF correction method based on the peak intensity of elements detected within a specified analytical range (e.g., the range magnified at 1500x) using a scanning electron microscope (SEM), with the total concentration set at 100%, to determine the ratio of the specified element to the principal component. The accelerating voltage used in elemental mapping is 15 kV.

[0050] In the base 22c, the cross-sectional height difference (Rδc) of the upper main surface 22c', that is, the difference between the cross-sectional height at 25% load length ratio and the cross-sectional height at 75% load length ratio in the roughness curve of the upper main surface 22c' of the base 22c, is not particularly limited. However, for the purpose of better suppressing dirt adhesion, better suppressing fluoride bonding, and making whitening less likely, the cross-sectional height difference (Rδc) of the upper main surface 22c' is preferably 0.17 μm or more and 0.38 μm or less.

[0051] If the cross-sectional height difference (Rδc) of the upper main surface 22c' is 0.17 μm or more, the contact angle between the upper main surface 22c' and pure water is small, exhibiting hydrophilicity. Therefore, when cleaning with pure water or the like after cleaning with an acid containing fluoride, the adhesion of air bubbles is reduced. As a result, the reduced adhesion of air bubbles can suppress the adhesion of dirt contained in the air bubbles. On the other hand, if the cross-sectional height difference (Rδc) of the upper main surface 22c' is 0.38 μm or less, the anchoring effect of fluoride on the upper main surface 22c' is reduced. As a result, the adhesion of fluoride can be further suppressed, making it more difficult for whitening to occur.

[0052] In the base 22c, the root mean square inclination (RΔq) in the roughness curve of the upper main surface 22c' is not particularly limited. However, the root mean square inclination (RΔq) of the upper main surface 22c' is preferably 0.18 or higher and 0.5 or lower, in order to better suppress the adhesion of dirt, better suppress the bonding of fluoride, and make the whitening phenomenon less likely to occur.

[0053] If the root mean square inclination (RΔq) of the upper principal surface 22c' is 0.18 or greater, the contact angle between the upper principal surface 22c' and pure water is small, exhibiting hydrophilicity. Therefore, when cleaning with pure water or the like after cleaning with an acid containing fluoride, the adhesion of air bubbles is reduced. As a result, the reduced adhesion of air bubbles can suppress the adhesion of dirt contained in the air bubbles. On the other hand, if the root mean square inclination (RΔq) of the upper principal surface 22c' is 0.5 or less, the anchoring effect of fluoride on the upper principal surface 22c' is reduced. As a result, the adhesion of fluoride can be further suppressed, making it more difficult for whitening to occur.

[0054] The cross-sectional height difference (Rδc) and root mean square tilt (RΔq) can be measured according to JIS B 0601:2001 using a laser microscope (Keyence AG, ultra-deep color 3D shape measuring microscope (VK-X1000 or its successor)). As for the measurement conditions, the illumination mode is set to coaxial illumination, the measurement magnification is set to 480x, the cutoff value λs is set to none, the cutoff value λc is set to 0.08mm, the correction for the terminal effect is set to yes, and the measurement range for each part is set to 710μm × 533μm. The measurement ranges are then set separately for three locations along the short side direction of the base 22c: the right end, the center, and the left end.

[0055] Furthermore, for each measurement range, four lines designated as the measurement objects are drawn out at approximately equal intervals, and line roughness measurements are performed. The length of each line designated as the measurement object is 560 μm, and the measurement is performed along the short side direction of the base 22c.

[0056] Alternatively, the clamping fixture 22 of one embodiment can be obtained by separately forming the support portion 22a, the gripping portion 22b, and the base portion 22c and joining them together. Alternatively, it can be an integrally formed article in which at least two of the support portion 22a, the gripping portion 22b, and the base portion 22c are integrally formed. In the case of an integrally formed article, since there is no bonding layer, separation will not occur at the bonding layer boundary. Particularly preferred is an integrally formed article in which all three portions—support portion 22a, gripping portion 22b, and base portion 22c—are integrally formed.

[0057] The base 22c contains a silicon carbide-based ceramic with a relative density of 95% or higher. This relative density is the percentage of the apparent density of the ceramic relative to its theoretical density, as determined according to JIS R 1634:1998. The theoretical density of the ceramic is determined by inductively coupled plasma optical emission spectrometry (ICP) or fluorescence X-ray diffraction, and each component is identified using CuKα line X-ray diffraction. If the identified components are SiC and B4C, the Si and B content values ​​determined by ICP or fluorescence X-ray diffraction are used to convert them to SiC and B4C.

[0058] At least the upper main surface 22c' of the base 22c has, for example, an area of ​​170 μm. 2 The above describes both coarse-grained silicon carbide particles and micro-grained silicon carbide particles with a grain diameter of less than 8 μm. Of course, grains with a diameter exceeding 8 μm and an area less than 170 μm may also exist. 2 Silicon carbide particles.

[0059] Furthermore, when at least the upper main surface 22c' of the base 22c contains coarse-grained silicon carbide particles with an area of ​​170 μm2 or more, which account for 6% to 15% of the area, even if micro-cracks are generated in the upper main surface 22c' due to thermal shock or mechanical shock, the coarse-grained silicon carbide particles can be used to suppress the propagation of cracks, thereby improving mechanical properties such as strength and rigidity, as well as thermal shock resistance.

[0060] Alternatively, the coarse-grained silicon carbide particles may contain at least one of open pores and closed pores.

[0061] When coarse-grained silicon carbide particles contain at least one of open pores and closed pores, even if micro-cracks occur within the coarse-grained silicon carbide particles due to thermal or mechanical shock, the propagation of cracks can be suppressed by the open and closed pores, thus improving thermal shock resistance.

[0062] The upper main surface 22c' preferably contains coarse-grained silicon carbide particles, which include at least one of, for example, two or more but less than five, open pores and closed pores. When it contains at least one of multiple open pores and closed pores, even if microcracks are generated in the coarse-grained silicon carbide particles due to thermal shock or mechanical impact, the propagation of cracks can be suppressed by adjacent open pores and closed pores, and it is difficult to affect adjacent silicon carbide particles.

[0063] The equivalent circle diameter of each open and closed pore is, for example, 1 μm or more and 5 μm or less, and they are independent of each other. The equivalent circle diameter of the open and closed pores is the arithmetic mean of the major and minor axes of the pores of the object, and can be obtained using the observation plane described later. The major axis is the length of the longest part of the pores of the object whose equivalent circle diameter is being measured, and the minor axis is the length of the longest part in the direction perpendicular to the major axis.

[0064] To identify coarse-grained silicon carbide particles, a tin-based polishing mill was used, employing diamond abrasive grains with a diameter of 1–3 μm, to polish until the arithmetic mean roughness Ra specified by JIS B 0601:2013 (ISO 4287:1997) was below 0.01 μm. Next, the base 22c was immersed in a heated molten solution of sodium hydroxide and potassium nitrate in a 1:1 mass ratio for 20 seconds to etch the polished surface.

[0065] Furthermore, using an optical microscope at 500x magnification, the etched surface was selected as the observation surface, where silicon carbide particles of various sizes were observed on average. This surface, where silicon carbide particles of various sizes were observed on average, was not intentionally chosen; rather, it contained an area exceeding 15000 μm where a single particle was not observed in other areas. 2 The region of the particles, the area of ​​which is 170 μm 2 The above-mentioned particle area refers to the area where coarse-grained silicon carbide particles and fine-grained silicon carbide particles are present on an average basis when observing a large area of ​​the etched surface.

[0066] Furthermore, the area ratio (area %) of coarse-grained silicon carbide particles in the observation surface was determined using an image of the observation surface and particle analysis software "A-Image-kun" (registered trademark, manufactured by Asahi Kasei Engineering Co., Ltd.). As a setting, the threshold for representing the density of the image was set to 150, and the extracted area was 170 μm. 2 The total area of ​​the coarse silicon carbide particles mentioned above divided by the area of ​​the observation surface, for example, 0.054 mm. 2 (The horizontal length is 0.27 mm and the vertical length is 0.2 mm) The percentage value is the area ratio of coarse silicon carbide particles.

[0067] The particles observed in the observation plane are silicon carbide particles, which can be confirmed by using a wavelength dispersion type X-ray microanalyzer (JXA-8600M model manufactured by Nippon Electron Co., Ltd.) to confirm the distribution of Si and C respectively. When the distributions of Si and C are superimposed, they coincide.

[0068] Next, an embodiment of the manufacturing method of the clamping fixture of the present invention will be described. The manufacturing method of the clamping fixture according to one embodiment includes the following steps (a) to (d).

[0069] (a) A process of filling a molding die with particles mainly composed of silicon carbide and molding them to obtain a molded body.

[0070] (b) The process of cutting the shaped body to obtain the precursor.

[0071] (c) The process of sintering the precursor to obtain a sintered body.

[0072] (d) A process in which the upper main surface of the base of the sintered body is set as the upper side and the lower main surface of the base is set as the lower side, the sintered body is placed on a sintering support table with carbon and carbides as the main components or on a powder with carbon and carbides as the main components, and heat-treated in an atmospheric atmosphere at a temperature of 300°C or higher and 750°C or lower.

[0073] Regarding step (a), firstly, particles mainly composed of silicon carbide are prepared, for example, using the following steps. As silicon carbide powder, coarse-grained powder and fine-grained powder are prepared. Ion-exchanged water, and dispersant as needed, are pulverized and mixed using a ball mill or bead mill for 40–60 hours to form a slurry. As for the mass ratio of fine-grained powder to coarse-grained powder, for example, the fine-grained powder may be 85% by mass or more and 94% by mass or less, and the coarse-grained powder may be 6% by mass or more and 15% by mass or less. The particle size range of the pulverized and mixed fine-grained powder and the coarse-grained powder is 0.4 μm or more and 4 μm or less, and 11 μm or more and 34 μm or less, respectively.

[0074] Next, a sintering aid and binder consisting of boron carbide powder, amorphous carbon powder, or phenolic resin are added to the obtained slurry and mixed. The mixture is then spray-dried to obtain particles whose main component is silicon carbide. Examples of binders include acrylic emulsions, polyvinyl alcohol, polyethylene glycol, and polyethylene oxide.

[0075] Next, the obtained particles are filled into a molding die and, for example, pressed under a pressure of 49 MPa or higher and 147 MPa to obtain a molded body. The obtained molded body is then supplied to process (b). Specifically, the obtained molded body is machined to obtain a precursor for a clamping fixture according to one embodiment. The obtained precursor is then supplied to process (c). Specifically, the obtained precursor is degreased by holding it in a nitrogen atmosphere at a temperature of 450°C or higher and 650°C or lower for 2 hours or more and 10 hours or less to obtain a degreased body. Next, the degreased body is held in a reduced-pressure atmosphere of an inert gas such as argon at a temperature of 1800°C or higher and 2200°C or lower for 3 hours or more and 6 hours or less to obtain a sintered body.

[0076] Next, the resulting sintered body is fed to process (d). Specifically, the resulting sintered body is subjected to heat treatment in an atmospheric atmosphere at a temperature of 300°C or higher and 750°C or lower. In an atmospheric atmosphere, by performing heat treatment (annealing) at a temperature of 300°C or higher and 750°C or lower, the carbon present on the upper main surface 22c' of the base 22c is more easily dispersed compared to the carbon present on the portion other than the upper main surface 22c'. As a result, the carbon present on the upper main surface 22c' of the base 22c becomes less than the carbon present on the portion other than the upper main surface 22c' of the base 22c. When performing this heat treatment, with the upper main surface 22c' of the base 22c set as the upper side and the lower main surface of the base 22c set as the lower side, it is placed on a firing support or powder base with at least one of carbon and carbides as the main component. The carbon is, for example, graphite. Carbides include silicon carbide, boron carbide, and titanium carbide.

[0077] The main component of the firing support or powder coating refers to a component that accounts for 90% or more by mass out of a total of 100% by mass of its respective components, and may also include silicon, aluminum, sodium, etc. In particular, the main component is preferably 95% by mass or more. When the base 22c is placed on the powder coating, the powder coatings can be arranged so that they are adjacent to each other and have the same or more area as the lower main surface of the base 22c. The heat treatment temperature is particularly preferably 400°C or higher and 500°C or lower.

[0078] The clamping fixture obtained by the above manufacturing method is less prone to whitening on the upper main surface of the base that is easily exposed to fluorine-containing acids such as hydrofluoric acid and hypofluorite. Therefore, the clamping fixture of the present invention reduces appearance degradation and can be used continuously for a long period of time as a component of cleaning devices, etc.

[0079] Explanation of reference numerals in the attached figures

[0080] 1. Shell

[0081] 2 chambers

[0082] 3 First Window

[0083] 4 First gate

[0084] 5-arm handling arm

[0085] 6 Second Window

[0086] 7 Second gate

[0087] 8-rotary chuck

[0088] 9 Gas Supply Department

[0089] 10 processing cups

[0090] 11 Lower board

[0091] 12 rotating plates

[0092] 13 cylindrical bodies

[0093] 14 belts

[0094] 15 motors

[0095] 16 on board

[0096] 17 Second Axis

[0097] 18 Second Horizontal Plate

[0098] 19 motors

[0099] 20 Second lifting mechanism

[0100] 21 Second Flow Path

[0101] 22 Clamping Fixture

[0102] 22a Support Section

[0103] 22b Control Department

[0104] 22c base

[0105] 22c' upper main face

[0106] 23First flow path

[0107] 24 First Axis

[0108] 25 level board

[0109] 26 First Lifting Mechanism

[0110] 30 Cleaning device.

Claims

1. A clamping fixture, wherein, The clamping fixture includes: Support section; A gripping portion, located at one end of the support portion, is used to grip the outer periphery of the substrate; and The base, located at the opposite end of the support portion, serves to support the support portion. At least the base comprises a ceramic with silicon carbide as the main component. In the base, there is less carbon on the upper main surface than there is carbon in the portion outside the upper main surface.

2. The clamping fixture according to claim 1, wherein, In the upper main surface of the base, the ratio of the carbon statistic to the silicon statistic, based on elemental mapping by an electron beam microscopy analyzer, is less than 0.

004.

3. The clamping fixture according to claim 1 or 2, wherein, The support portion comprises a ceramic mainly composed of silicon carbide, and at least the support portion and the base portion are integrally formed.

4. The clamping fixture according to claim 1 or 2, wherein, The section height difference (Rδc), which represents the difference between the section height at 25% load length ratio and the section height at 75% load length ratio in the roughness curve of the upper main surface of the base, is 0.17 μm or more and 0.38 μm or less.

5. The clamping fixture according to claim 1 or 2, wherein, The root mean square inclination (RΔq) in the roughness curve of the upper main surface of the base is greater than 0.18 and less than 0.

5.

6. The clamping fixture according to claim 1 or 2, wherein, The base has at least 6% to 15% of an area of ​​170 μm on its upper main surface. 2 The above are coarse-grained silicon carbide particles.

7. The clamping fixture according to claim 6, wherein, The coarse-grained silicon carbide particles include at least one of open pores and closed pores.

8. A method for manufacturing a clamping fixture, wherein, The method for manufacturing the clamping fixture includes: The process of filling silicon carbide-based particles into a molding die and forming them to obtain a molded body; The process of cutting the shaped body to obtain the precursor; The process of sintering the precursor to obtain a sintered body; and With the upper main surface of the base of the sintered body set as the upper side and the lower main surface of the base set as the lower side, the sintered body is placed on a sintering support table with carbon and carbides as the main components or on a powder with carbon and carbides as the main components, and heat-treated in an atmospheric atmosphere at a temperature of 300°C or higher and 750°C or lower.

9. A cleaning device, wherein, The cleaning device includes a clamping fixture as described in any one of claims 1 to 7.

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