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

Abstract

The clamping fixture of the present invention includes: a support portion; a holding portion located at one end of the support portion and holding the outer periphery of a substrate; and a base portion located at the other end of the support portion and supporting the support portion. At least the base portion comprises a ceramic primarily composed of silicon carbide. The average value of the section height difference (Rδcl), representing 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 base portion along its long side, is smaller on the upper main surface of the base compared to the lower main surface of the base portion.

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 holding portion located at one end of the support portion and holding the outer periphery of a substrate; and a base portion located at the other end of the support portion and supporting the support portion. At least the base portion comprises a ceramic primarily composed of silicon carbide. The average value of the section height difference (Rδcl), representing 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 base portion along its long side, is smaller on the upper main surface of the base compared to the lower main surface of the base portion.

[0010] Another clamping fixture of the present invention includes: a support portion; a holding portion located at one end of the support portion and holding the outer periphery of a substrate; and a base portion located at the other end of the support portion and supporting the support portion. At least the base portion comprises a ceramic primarily composed of silicon carbide. The average value of the section height difference (Rδcs), representing 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 base portion in the short-side direction, is smaller on the upper main surface of the base portion compared to the lower main surface of the base portion.

[0011] The method for manufacturing a 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 polishing and grinding at least the upper main surface of the sintered body.

[0012] Furthermore, the cleaning apparatus of the present invention includes the aforementioned clamping fixture. Attached Figure Description

[0013] 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.

[0014] Figure 2 This is an enlarged view showing a clamping fixture according to an embodiment of the present invention. Detailed Implementation

[0015] In liquid treatment apparatuses such as those described in Patent Document 1, where a clamping fixture made of ceramic with silicon carbide as the holding mechanism is used, if the workpiece, such as a semiconductor substrate, is repeatedly cleaned with fluorine-containing acids such as hydrofluoric acid or hypofluorite over a long period, the fluorine adheres to the carbon on the surface of the clamping fixture, causing it to whiten. Therefore, a clamping fixture is sought that will not cause whitening on the surface of the workpiece even when it is repeatedly cleaned with fluorine-containing acids such as hydrofluoric acid or hypofluorite over a long period.

[0016] As described above, the clamping fixture of the present invention has a smaller average value for the section height difference (Rδcl), which represents the difference between the section height at 25% of the load length ratio and the section height at 75% of the load length ratio in the roughness curve of the base in the long side direction, compared to the lower main surface of the base. Alternatively, the average value for the section height difference (Rδcs), which represents the difference between the section height at 25% of the load length ratio and the section height at 75% of the load length ratio in the roughness curve of the base in the short side direction, compared to the lower main surface of the base, is smaller. As a result, even when the workpiece is repeatedly cleaned with fluorine-containing acids such as hydrofluoric acid or hypofluorite over a long period, it is difficult for whitening to occur on the upper main surface of the base, which is easily exposed to fluorine-containing acids. Therefore, the clamping fixture of the present invention reduces appearance degradation and can be used for a long period of time.

[0017] 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.

[0018] 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. When the substrate W is a semiconductor wafer, the semiconductor wafer is made of, for example, Si, SiC, GaN, etc.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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." (The positions can be moved freely between these points.)

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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 rotate via a motor 19 mounted on a second 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.

[0030] 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.

[0031] 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.

[0032] Cleaning solutions can include, for example, hydrofluoric acid, hypofluorite, and other acids containing fluorine.

[0033] After the substrate W is held in the clamping fixture 22, the substrate W is cleaned. At this time, after the processing cup 10 is raised, the used medicine, pure water, etc. are discharged from the drain pipe 10a.

[0034] 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.

[0035] 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.

[0036] The support member 22a is a component used to connect the gripping part (described later) and the base, 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.

[0037] 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.

[0038] When the support portion 22a is formed of ceramic with silicon carbide as the main component, other components may include metallic silicon, boron, free carbon, etc. When metallic silicon is included, it may be either crystalline silicon or amorphous silicon. When the support portion 22a is formed of ceramic with aluminum oxide as the main component, other components may include oxides of magnesium, silicon, and calcium.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] The base 22c is disposed at the other end of the support portion 22a, that is, 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, metallic silicon, boron, free carbon, etc. When metallic silicon is included, the metallic silicon may be either crystalline silicon or amorphous silicon.

[0044] In the base 22c formed of a ceramic primarily composed of silicon carbide, the average value of the cross-sectional height difference (Rδcl), which represents the difference between the cross-sectional height at 25% of the load length ratio and the cross-sectional height at 75% of the load length ratio in the roughness curve of the base 22c', is smaller than that of the lower main surface 22c'. Therefore, even if the substrate W or other objects to be cleaned are 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 22c, which is easily exposed to fluorine-containing acids. As a result, the clamping fixture 22 of the present invention reduces appearance degradation and can be used for a long period of time.

[0045] Specifically, the upper main surface 22c' of the base 22c contains force-applying components such as the support portion 22a located on the outer periphery and the spring (not shown) located in the center of the upper main surface 22c', which hinder the removal of the cleaning fluid (fluoride-containing acid) by centrifugal force. Furthermore, as with the lower main surface 22c", it is not expected that the cleaning fluid will be removed by natural falling due to gravity. As a result, even when cleaning the substrate W while it is placed on the rotating plate 12 and rotated, cleaning fluid easily remains on the upper main surface 22c'. Therefore, by specifying the average value of the cross-sectional height difference (Rδcl) as described above, the contact angle of the cleaning fluid with respect to the upper main surface 22c' can be increased. Therefore, the water repellency of the upper main surface 22c' can be improved, and the adhesion of fluoride contained in the cleaning fluid can be suppressed.

[0046] In the base 22c, the difference is not limited as long as the average value of the section height difference (Rδcl), which represents the difference between the section height at 25% of the load length ratio and the section height at 75% of the load length ratio in the roughness curve of the long side direction of the base 22c, is smaller than that of the upper main surface 22c' and the lower main surface 22c”. However, the difference between the average value of the section height difference (Rδcl) of the upper main surface 22c' and the average value of the section height difference (Rδcl) of the lower main surface 22c” of the base 22c is preferably 0.16 μm or more.

[0047] In the lower main surface 22c”, the average value of the section height difference (RScl), 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 long side direction of the base 22c, is less than 0.35 μm. Here, the base 22c has a rectangular shape when viewed from above, and the long side directions of the upper main surface 22c' and the lower main surface 22c” are the radial directions of the substrate W, while the short side directions, described later, are the circumferential directions of the substrate W.

[0048] If the average value of the cross-sectional height difference (Rδcl) in the lower main surface 22c” is less than 0.35 μm, then particles detaching from the lower main surface 22c” are suppressed. Therefore, contamination within the cleaning device caused by detached particles can be suppressed.

[0049] Alternatively, in the base 22c formed of a ceramic primarily composed of silicon carbide, the average value of the cross-sectional height difference (Rδcs), which represents the difference between the cross-sectional height at 25% of the load length ratio and the cross-sectional height at 75% of the load length ratio in the roughness curve of the base 22c, is smaller than that of the upper main surface 22c' and the lower main surface 22c'. For the reasons stated above, this improves the water repellency of the upper main surface 22c' and inhibits the adhesion of fluoride contained in the cleaning fluid.

[0050] In particular, the difference between the average value of the cross-sectional height difference (Rδcs) of the upper main surface 22c' of the base 22c and the average value of the cross-sectional height difference (Rδcs) of the lower main surface 22c” of the base 22c is preferably 0.16 μm or more.

[0051] Furthermore, in the lower main surface 22c", the average value of the section height difference (Rδcs), 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 short side direction of the base 22c, is preferably 0.35 μm or less. As explained above, this allows for the suppression of contamination within the cleaning apparatus caused by detached particles.

[0052] The upper main surface 22c' of the base 22c can also be a mirror surface or a glossy surface. In this case, the ratio (Ra1 / Ra2) of the average arithmetic mean roughness Ra1 in the long side direction of the base 22c to the average arithmetic mean roughness Ra2 in the short side direction of the base 22c is preferably 0.9 or more and 1.3 or less. If such a ratio is used, the difference caused by the direction of the arithmetic mean roughness Ra is small. As a result, the adhesion of fluoride contained in the cleaning fluid can be further suppressed, and it can be used for a long period of time. Furthermore, the mirror surface or glossy surface may have cutting marks along at least one of the short side direction and the long side direction of the base 22c. Cutting marks are particularly prone to form in the short side direction of the base 22c.

[0053] The cross-sectional height difference (Rδcl), cross-sectional height difference (Rδcs), arithmetic mean roughness Ra1, and arithmetic mean roughness Ra2 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 end effect correction 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 parts along the short side direction of the base 22c: the right end, the center, and the left end.

[0054] Furthermore, for each measurement range, four lines designated as measurement objects are drawn out at approximately equal intervals, and surface roughness measurements are performed. For example, the length of each line designated as the measurement object is 401 μm in the vertical direction of the measurement range when the long side direction of the base 22c is designated as the object, and 560 μm in the horizontal direction of the measurement range when the short side direction of the base 22c is designated as the object.

[0055] The average values ​​of the section height difference (Rδcl), section height difference (Rδcs), arithmetic mean roughness Ra1, and arithmetic mean roughness Ra2 are the average values ​​of the measured values ​​obtained from a total of 12 lines of the object being measured. The section height difference (Rδcl) and section height difference (Rδcs) of the lower main surface can also be obtained using the same method as described above.

[0056] Alternatively, the upper main surface 22c' of the base 22c can be connected to the side surface of at least one of the bases 22c via a curved surface. When formed by a curved surface, it becomes an inclined surface with curvature from the upper main surface 22c' toward the side surface. Therefore, the slippage of the fluorinated acid (cleaning liquid) is improved. Furthermore, compared to the case where the upper main surface 22c' and the side surface are orthogonal, the possibility of threshing is reduced.

[0057] Alternatively, the curved surface may have multiple grooves along the short side of the base 22c. By having such grooves on the curved surface, the fluorinated acid (cleaning solution) is dispersed within the grooves. As a result, the flowability of the fluorinated acid (cleaning solution) is improved. The shape of the grooves is not limited; for example, a U-shaped groove is preferred. A U-shaped groove does not have a surface orthogonal to the surface forming the groove. As a result, the likelihood of granulation is reduced compared to the case where an orthogonal surface exists.

[0058] The average arithmetic mean roughness Ra3 of the surface along its long side is preferably 0.1 μm or more and 0.8 μm or less. When the average arithmetic mean roughness Ra3 of the surface falls within this range, the water repellency is increased. Therefore, residues generated by the adhesion of fluorine-containing acids (cleaning solutions) are less likely to remain. Furthermore, the possibility of particles being removed from the surface is reduced.

[0059] The arithmetic mean roughness Ra3 can be measured using the laser microscope described above. As 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 end effect correction is set to yes, the measurement range for each part is set to 710μm × 533μm, and the measurement range is set separately for two parts: the right end and the left end of the short side direction of the base 22c.

[0060] Furthermore, for each measurement range, four lines designated as the measurement object are drawn out at approximately equal intervals along the horizontal direction of the measurement range, and surface roughness measurements are performed. The length of each line designated as the measurement object is, for example, 560 μm. The arithmetic mean roughness Ra3 is the average of the measured values ​​obtained from a total of eight lines designated as the measurement object.

[0061] 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.

[0062] 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.

[0063] At least the upper main surface 22c' of the base 22c has, for example, an area of ​​170 μm. 2The 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.

[0064] Furthermore, when at least the upper main surface 22c' of the base 22c contains an area of ​​170 μm that is more than 6% and less than 15% of the area. 2 When using the coarse-grained silicon carbide particles described above, even if micro-cracks are generated within the upper main surface 22c' due to thermal or mechanical shock, the propagation of these cracks can be suppressed. As a result, mechanical properties such as strength and rigidity, as well as thermal shock resistance, are improved.

[0065] Alternatively, the coarse-grained silicon carbide particles may contain at least one of open pores and closed pores. When the 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 the cracks can be suppressed by the open and closed pores. As a result, thermal shock resistance is improved.

[0066] The upper main surface 22c' preferably comprises 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 includes 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. As a result, it is difficult to affect adjacent silicon carbide particles.

[0067] 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.

[0068] 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.

[0069] 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 evenly present when observing a large area of ​​the etched surface.

[0070] 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.

[0071] 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.

[0072] 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).

[0073] (a) A process of filling a molding die with particles mainly composed of silicon carbide and molding them to obtain a molded body.

[0074] (b) The process of cutting the shaped body to obtain the precursor.

[0075] (c) The process of sintering the precursor to obtain a sintered body.

[0076] (d) A process of polishing and grinding at least the upper main surface of the sintered body that forms the base.

[0077] Regarding process (a), firstly, particles with silicon carbide as the main component are prepared, for example, using the following steps. As silicon carbide powder, coarse powder and fine powder are prepared, and ion-exchanged water and, if necessary, a dispersant are pulverized and mixed using a ball mill or bead mill for 40 to 60 hours to form a slurry. As for the mass ratio of fine powder to coarse powder, for example, the fine powder may be 85% by mass or more and 94% by mass or less, and the coarse powder may be 6% by mass or more and 15% by mass or less.

[0078] The particle sizes of the pulverized and mixed fine powder and coarse powder each range from 0.4 μm to 4 μm and 11 μm to 34 μm, respectively. Next, a sintering aid and binder composed of boron carbide powder, amorphous carbon powder, or phenolic resin are added to the obtained slurry, and after mixing, it is spray-dried to obtain particles whose main component is silicon carbide. Examples of binders include acrylic emulsions, polyvinyl alcohol, polyethylene glycol, and polyethylene oxide.

[0079] The principal component in the particles refers to the component that accounts for more than 80% by mass when the total of the components excluding the binder is set at 100% by mass. The content of the components constituting the particles can be determined, for example, using an ICP (Inductively Coupled Plasma) luminescence spectrophotometer or a fluorescence X-ray analysis device.

[0080] 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.

[0081] Next, the resulting sintered body is fed into process (d). Specifically, the upper main surface of the sintered body obtained in process (c), which serves as at least the base, is polished. The substrate for polishing is not limited; examples include felt, cotton strips, and kapok strips. Examples of abrasives include diamond powder and green silicon carbide (GC) powder. These abrasives are added to an oil-based mixture and used in a paste form.

[0082] The average particle size of the abrasive is, for example, 0.5 μm or more and 6 μm or less. The outer diameter of the substrate is 150 mm, and its rotational speed is, for example, 28 m / min or more and 170 m / min or less. The grinding time is, for example, 0.5 minutes or more and 5 minutes or less. In order to obtain a clamping fixture with a ratio (Ra1 / Ra2) of 0.9 or more and 1.3 or less for the average value of the arithmetic mean roughness Ra1 to the average value of the arithmetic mean roughness Ra2, the average particle size of the abrasive is set to 2 μm or more and 6 μm or less.

[0083] The cross-sectional height difference (Rδcl) was measured for a clamping fixture obtained by the manufacturing method of a clamping fixture according to one embodiment. First, the cross-sectional height difference (Rδcl) was measured on the upper main surface 22c' of the base 22c, and the average value was calculated. The average value was 0.1821 μm. Similarly, the cross-sectional height difference (Rδcl) was measured on the lower main surface 22c" of the base 22c, and the average value was calculated. The average value was 0.2586 μm.

[0084] Thus, it can be seen that, compared with the lower main surface 22c", the average value of the section height difference (Rδcl), 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 long side direction of the base 22c, is smaller.

[0085] Furthermore, the aforementioned cross-sectional height difference (Rδcs) was measured on the upper main surface 22c' of the base 22c, and the average value was calculated. The average value was 0.1659 μm. Similarly, the aforementioned cross-sectional height difference (Rδcs) was measured on the lower main surface 22c” of the base 22c, and the average value was calculated. The average value was 0.2614 μm.

[0086] Thus, it can be seen that, compared with the lower main surface 22c", the average value of the section height difference (Rδcs), 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 base 22c in the short side direction, is smaller on the upper main surface 22c'.

[0087] Next, the arithmetic mean roughness Ra of the upper main surface 22c' of the base 22c was measured for the clamping fixture obtained by the manufacturing method of the clamping fixture according to one embodiment. The arithmetic mean roughness Ra1 of the upper main surface 22c' of the base 22c in the long side direction is 0.1296 μm. On the other hand, the arithmetic mean roughness Ra2 of the upper main surface 22c' of the base 22c in the short side direction is 0.1218 μm. The ratio of the arithmetic mean roughness Ra1 to the arithmetic mean roughness Ra2 (Ra1 / Ra2) is 1.06.

[0088] The cross-sectional height difference (Rδcl), cross-sectional height difference (Rδcs), arithmetic mean roughness Ra1, and arithmetic mean roughness Ra2 are all measured values ​​obtained by the above-mentioned measurement methods, and their average values ​​are calculated based on these measured values.

[0089] 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.

[0090] Explanation of reference numerals in the attached figures

[0091] 1. Shell

[0092] 2 chambers

[0093] 3 First Window Section

[0094] 4 First gate

[0095] 5. Handling arm

[0096] 6 Second Window

[0097] 7 Second gate

[0098] 8. Rotary chuck

[0099] 9. Gas Supply Department

[0100] 10 processing cups

[0101] 11 Lower board

[0102] 12 Rotating Plate

[0103] 13. Cylindrical body

[0104] 14 belts

[0105] 15 motors

[0106] 16 board

[0107] 17 Second Axis

[0108] 18 Second Horizontal Plate

[0109] 19 motors

[0110] 20 Second lifting mechanism

[0111] 21 Second Flow Path

[0112] 22 Clamping fixtures

[0113] 22a Support column

[0114] 22b Control Department

[0115] 22c base

[0116] 22c' Top Main Face

[0117] 22c” Bottom Main Face

[0118] 23 First flow path

[0119] 24 First Axis

[0120] 25 Horizontal Plate

[0121] 26 First Lifting Mechanism

[0122] 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, grips the outer periphery of the substrate; and The base, located at the opposite end of the support portion, supports the support portion. At least the base comprises a ceramic with silicon carbide as the main component. Compared to the lower main surface of the base, the average value of the cross-sectional height difference (Rδcl), which represents 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 base along its long side, is smaller on the upper main surface of the base.

2. The clamping fixture according to claim 1, wherein, The difference between the average value of the cross-sectional height difference (Rδcl) of the upper main surface of the base and the average value of the cross-sectional height difference (Rδcl) of the lower main surface of the base is 0.16 μm or more.

3. The clamping fixture according to claim 2, wherein, The average value of the section height difference (Rδcl), 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 lower main surface of the base, is less than 0.35 μm.

4. The clamping fixture according to any one of claims 1 to 3, wherein, The upper main surface of the base is a mirror or glossy surface. The ratio (Ra1 / Ra2) of the average arithmetic mean roughness (Ra1) of the base along the long side to the average arithmetic mean roughness (Ra2) of the base along the short side is 0.9 or more and 1.3 or less.

5. The clamping fixture according to claim 4, wherein, The mirror surface or the glossy surface has cutting marks along at least one of the short side direction and the long side direction of the base.

6. The clamping fixture according to any one of claims 1 to 3, wherein, The upper main surface of the base is connected to the side surface of at least one of the bases by a curved surface.

7. The clamping fixture according to claim 6, wherein, The average arithmetic mean roughness (Ra3) of the surface along the long side is greater than 0.1 μm and less than 0.8 μm.

8. The clamping fixture according to any one of claims 1 to 3, 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.

9. The clamping fixture according to any one of claims 1 to 3, 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.

10. The clamping fixture according to claim 9, wherein, The coarse-grained silicon carbide particles include at least one of open pores and closed pores.

11. A clamping fixture, wherein, The clamping fixture includes: Support section; A gripping portion, located at one end of the support portion, grips the outer periphery of the substrate; and The base, located at the opposite end of the support portion, supports the support portion. At least the base comprises a ceramic with silicon carbide as the main component. Compared to the lower main surface of the base, the average value of the cross-sectional height difference (Rδcs), which represents 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 base in the short side direction, is smaller on the upper main surface of the base.

12. The clamping fixture according to claim 11, wherein, The difference between the average value of the cross-sectional height difference (Rδcs) of the upper main surface of the base and the average value of the cross-sectional height difference (Rδcs) of the lower main surface of the base is 0.16 μm or more.

13. The clamping fixture according to claim 11 or 12, wherein, The average value of the section height difference (Rδcs), 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 lower main surface of the base, is less than 0.35 μm.

14. The clamping fixture according to claim 11 or 12, wherein, The upper main surface of the base is a mirror or glossy surface. The ratio (Ra1 / Ra2) of the average arithmetic mean roughness (Ra1) of the base along the long side to the average arithmetic mean roughness (Ra2) of the base along the short side is 0.9 or more and 1.3 or less.

15. The clamping fixture according to claim 14, wherein, The mirror surface or the glossy surface has cutting marks along at least one of the short side direction and the long side direction of the base.

16. The clamping fixture according to claim 11 or 12, wherein, The upper main surface of the base is connected to the side surface of at least one of the bases by a curved surface.

17. The clamping fixture according to claim 16, wherein, The surface has a plurality of grooves along the direction of the short side.

18. The clamping fixture according to claim 17, wherein, The groove is a U-shaped groove.

19. The clamping fixture according to claim 11 or 12, 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.

20. The clamping fixture according to claim 11 or 12, wherein, At least the upper side main surface of the base portion contains 6 area% or more and 15 area% or less of the area of 170 μm 2 The above coarse granular silicon carbide particles.

21. The clamping fixture according to claim 20, wherein, The coarse-grained silicon carbide particles include at least one of open pores and closed pores.

22. A method for manufacturing a clamping fixture, wherein the clamping fixture is the clamping fixture according to any one of claims 1 to 21, 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 The process of polishing and grinding at least the upper main surface of the base of the sintered body.

23. A cleaning apparatus, wherein, The cleaning device includes a clamping fixture as described in any one of claims 1 to 21.

Images