Clamping fixtures and cleaning equipment

Abstract

A clamping jig according to the present disclosure comprises: a support column part; a holding part which is positioned at one end of the support column part for the purpose of holding the outer peripheral part of a substrate; and a base part which is positioned at the other end of the support column part for the purpose of supporting the support column part. The holding part comprises: a main body which is formed of a ceramic that is mainly composed of silicon carbide or zirconium oxide; and a first thermal insulation layer which is positioned at the front end of the main body and has a thermal conductivity that is lower than the thermal conductivity of the main body.

Description

[Technical Field]

[0001] The present invention relates to a clamping jig for holding a substrate such as a semiconductor wafer or a liquid crystal display (LCD) substrate, and to a cleaning device using the same. [Background technology]

[0002] Conventionally, cleaning devices have been used to clean substrates with cleaning liquids such as predetermined chemicals or pure water to remove particles, organic contaminants, metal impurities, and other contaminants adhering to the substrate, as well as polymers remaining after etching.

[0003] As a liquid processing apparatus including such a cleaning device, Patent Document 1 discloses a liquid processing apparatus that includes a holding means for holding a substrate horizontally, the holding means having a gripper for holding an edge surface of the substrate. As the holding means for holding the substrate horizontally, Patent Document 2 proposes a clamper that presses down on the substrate from above, and describes that the material of the clamper is silicon carbide. Patent Document 3 proposes an annular clamping jig having an anti-adhesion layer (conductive layer) that suppresses adhesion of resist material on the contact surface that comes into contact with the substrate, and cites alumina as an example of the clamp material and a DLC (Diamond Like Carbon) film as an example of the anti-adhesion layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5726686 [Patent Document 2] Japanese Patent Application Publication No. 4-130627 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-154866 Summary of the Invention

[0005] The clamping jig of the present disclosure includes a support portion, a gripping portion located at one end of the support portion for gripping the outer periphery of the substrate, and a base portion located at the other end of the support portion for supporting the support portion, and the gripping portion has a main body made of ceramics primarily composed of silicon carbide or zirconium oxide, and a first insulating layer located at the tip of the main body and having a lower thermal conductivity than the main body.

[0006] The cleaning device according to the present disclosure includes the clamping jig. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram illustrating a general configuration of a cleaning device equipped with a clamping jig according to an embodiment of the present disclosure. [Figure 2A] 2 is a cross-sectional view showing the clamping jig shown in FIG. 1 and a state in which the clamping jig is attached to a rotating plate. FIG. [Figure 2B] FIG. 2B is an enlarged view showing an example of part A in FIG. 2A. [Figure 2C] FIG. 2C is an enlarged top view of part A shown in FIG. 2B. [Figure 3A] 3 is a schematic enlarged cross-sectional view showing the boundary portion between the main body and the first insulating layer in one embodiment of the present disclosure. FIG. [Figure 3B] 3 is a schematic enlarged cross-sectional view showing the boundary portion between the main body and the second insulating layer in one embodiment of the present disclosure. FIG. [Figure 4] 1 is a photomicrograph showing a surface obtained by polishing and etching a cross section of a clamping jig according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] The clamping jig of the present disclosure will be described in detail below with reference to Figures 1 and 2. Figure 1 is a schematic diagram showing the general configuration of a cleaning device 30 equipped with a clamping jig 22 according to one embodiment of the present disclosure.

[0009] The cleaning apparatus 30 shown in FIG. 1 includes a housing 1 and a chamber 2 that provides a space inside the housing 1 for cleaning various substrates W such as semiconductor wafers and liquid crystal display (LCD) substrates.

[0010] The housing 1 has a first window 3 for loading and unloading a substrate W into and from the housing 1, and the first window 3 is opened and closed by a first shutter 4. A transport arm 5 carries the substrate W and loads and unloads the substrate W into and from the housing 1 through the first window 3.

[0011] The first window 3 is closed by a first shutter 4 except when the substrate W is being loaded or unloaded. The first shutter 4 is installed inside the housing 1 so that the first window 3 can be opened and closed from inside the housing 1.

[0012] The chamber 2 has a second window 6 for loading and unloading the substrate W into and from the chamber 2, and the second window 6 is opened and closed by a second shutter 7. The transport arm 5 enters and exits the chamber 2 through the second window 6, and delivers the substrate W to and from a rotating chuck 8 installed inside the chamber 2.

[0013] The second shutter 7 is installed inside the chamber 2 and is configured to open and close the second window portion 6 from inside the chamber 2.

[0014] A gas supply unit 9 that supplies a dry gas such as nitrogen into the chamber 2 is provided on the top plate of the chamber 2. The gas supply unit 9 supplies the dry gas downward to prevent the chamber 2 from filling up with air due to evaporation of the chemical solution supplied to the substrate W held on the rotating chuck 8. When the dry gas is supplied downward, watermarks, which are contaminants, are less likely to form on the surface of the substrate W.

[0015] Within the chamber 2 are a processing cup 10 for accommodating the substrate W, a rotating chuck 8 for holding the substrate W within the processing cup 10, an underplate 11 positioned away from the back surface of the substrate W, and a top plate 16 positioned away from the front surface of the substrate W.

[0016] Processing cup 10 has an inclined portion at its top and a drain 10a at its bottom. Processing cup 10 can be raised and lowered between a position where the inclined portion of the upper portion is located above substrate W held by rotating chuck 8 (the position shown by the solid line in FIG. 1; hereinafter, this may be referred to as the "processing position") and a position where the upper portion is located below substrate W held by rotating chuck 8 (the position shown by the two-dot chain line in FIG. 1; hereinafter, this may be referred to as the "retracted position").

[0017] When transferring the substrate W between the transfer arm 5 and the rotary chuck 8, the processing cup 10 is held in a retracted position so as not to interfere with the advancement or retreat of the transfer arm 5. On the other hand, when cleaning the substrate W held on the rotary chuck 8, the processing cup 10 is held in a processing position. The processing cup 10 held in the processing position prevents the cleaning liquid supplied to the substrate W from splashing around and also guides the cleaning liquid used in cleaning the substrate W to a drain 10a. The drain 10a is connected to a cleaning liquid recovery line and an exhaust duct. The drain 10a is configured to discard mist and the like generated in the processing cup 10 and to recover the cleaning liquid in the chamber 2.

[0018] The rotary chuck 8 has a disk-shaped rotating plate 12 and a cylindrical body 13 connected to the rotating plate 12. Supports for supporting the substrate W and clamping jigs 22 for fixing the substrate W are attached to the outer periphery of the rotating plate 12. The supports are arranged at at least three positions along the circumference at equal intervals and support the backside of the substrate W. The clamping jigs 22 are arranged at multiple positions, for example, at least three positions, along the circumference at equal intervals and fix the substrate W from the outer periphery. A belt 14 is wound around the outer periphery of the cylindrical body 13. By driving the belt 14 with a first motor 15, the cylindrical body 13 and the rotating plate 12 are rotated, and the substrate W fixed by the clamping jigs 22 can be rotated.

[0019] The underplate 11 is connected to a first shaft 24 that penetrates the center of the rotating plate 12 and the inside of the cylinder 13. The first shaft 24 is fixed to a first horizontal plate 25, and the first horizontal plate 25 can be raised and lowered together with the first shaft 24 by a first lifting mechanism 26 such as an air cylinder. The underplate 11 and the first shaft 24 are provided with a first flow path 23 that supplies a chemical solution, a cleaning liquid such as pure water, or a drying gas toward the substrate W.

[0020] A disk-shaped top plate 16 located near the top plate of the chamber 2 is connected to the lower end of a cylindrical second shaft 17. The top plate 16 is rotatable by a second motor 19 provided on a second horizontal plate 18. The second shaft 17 is rotatably supported on the underside of the second horizontal plate 18. The second horizontal plate 18 can be raised and lowered in the vertical direction by a second lifting mechanism 20, such as an air cylinder, fixed to the top plate of the chamber 2. A second flow path 21 is provided inside each of the top plate 16 and the second shaft 17 along the axial direction, for supplying a chemical solution, a cleaning liquid such as pure water, or a drying gas.

[0021] When the substrate W is transferred between the rotary chuck 8 and the transfer arm 5, the top plate 16 is held in a position close to the ceiling of the chamber 2 so as not to collide with the transfer arm 5. When cleaning the surface (upper surface) of the substrate W, the top plate 16 is lowered to a position close to the surface of the substrate W held by the clamping jig 22, and a cleaning liquid etc. is supplied toward the substrate W through the second flow path 21. After cleaning, a rinse process is performed by supplying pure water etc. toward the substrate W to wash away the cleaning liquid etc. Thereafter, the substrate W is rotated to dry the pure water etc. adhering to the substrate W by centrifugal force.

[0022] When cleaning the front and back surfaces (top and bottom surfaces) of the substrate W simultaneously, the back surface of the substrate W is cleaned using the underplate 11 and the first flow path 23 at the same time as cleaning the front surface of the substrate W as described above. A method for cleaning the back surface of the substrate W involves, for example, first bringing the underplate 11 close to the back surface of the substrate W. Next, a chemical solution is supplied from the first flow path 23 between the substrate W and the underplate 11 to form a chemical solution layer. This is held for a predetermined time to perform chemical treatment, and then pure water or the like is supplied from the first flow path 23 between the substrate W and the underplate 11 to flush out the chemical solution and perform a rinsing treatment. Next, a method is used in which the substrate W is dried by rotating at high speed while a dry gas is supplied from the first flow path 23 between the substrate W and the underplate 11.

[0023] Examples of chemical solutions include aqueous solutions of concentrated nitric acid, hydrochloric acid, SPM (Sulfuric acid Hydrogen Peroxide Mixture), ammonia-based chemical solutions such as ammonia hydrogen peroxide (APM), hydrofluoric acid-based chemical solutions such as dilute hydrofluoric acid (DHF), sulfuric acid-based chemical solutions such as sulfuric acid hydrogen peroxide (SPM), phosphoric acid aqueous solution, sodium hydroxide aqueous solution, etc.

[0024] The substrate W is cleaned after being held by the clamping jig 22. At this time, the processing cup 10 is raised, and then the used chemicals, pure water, etc. are discharged from the drain 10a.

[0025] When cleaning of the substrate W is completed, the processing cup 10 and underplate 11 are lowered. With the top plate 16 raised, the substrate W is transferred from the clamping jig 22 to the support. Next, the first shutter 4 and the second shutter 7 are opened, and the transport arm 5 is advanced into the chamber 2. In this state, the substrate W is transferred from the rotary chuck 8 to the transport arm 5 in the reverse order of the procedure for transferring the substrate W from the transport arm 5 to the rotary chuck 8 described above, and the substrate W is unloaded from the cleaning apparatus 30.

[0026] Next, the clamping jig 22 and the state in which the clamping jig 22 is attached to the rotary plate 12 will be described.

[0027] FIG. 2A is a cross-sectional view showing the clamping jig 22 shown in FIG. 1 and the state in which the clamping jig 22 is attached to the rotary plate 12. 2B is figure 2A FIG. 1 is an enlarged view showing an example of part A; 2C is FIG. 2C is an enlarged top view of part A shown in FIG. 2B.

[0028] The clamping jig 22 includes a support portion 22a extending in the vertical direction, a gripping portion 22b connected to one end portion, which is the upper portion of the support portion 22a, and abutting against the outer periphery of the substrate W, and a base portion 22e located at the other end portion, which is the lower portion of the support portion 22a, for supporting the support portion 22a. The gripping portion 22b includes a base end portion 22c located on the support portion 22a side and a tip portion 22d connected to the base end portion 22c. The portion of the tip portion 22d that abuts against the outer periphery of the substrate W is claw-shaped. The base portion 22e connects to the support portion 22a from below and supports the support portion 22a. The base portion 22e has a through hole 22f formed along the width direction of the clamping jig 22.

[0029] The tip portion 22d has opposing surfaces 22g that face the outer periphery of the substrate W and sandwich the edges of the front and back surfaces of the substrate W from diagonally above and below. The substrate W is sandwiched and held in a groove formed by these opposing surfaces 22g.

[0030] The tip portions 22d are provided spaced apart from each other in the width direction of each clamping jig 22 (see FIG. 2C). If there were only one tip portion 22d, the tip portion 22d might hold a notch formed in the substrate W, which could result in unstable holding of the substrate W. However, with the two spaced apart tip portions 22d, the substrate W can be reliably held regardless of the position of the notch formed in the substrate W.

[0031] When pressing member 27 is moved upward to press the convex portion of base 22e against rotating plate 12, spring 28 contracts, causing the entire clamping jig 22 to rotate around cylindrical third shaft 29. At this time, tip 22d moves outward from rotating plate 12. On the other hand, when pressing member 27 is moved downward, spring 28 expands, causing tip 22d to move inward from rotating plate 12, causing the entire clamping jig 22 to rotate around third shaft 29. In this way, pressing member 27 and spring 28 have the function of adjusting the position of tip 22d. Although the clamping jig 22 described above is a clamping jig having base 22e, base 22e is not essential.

[0032] 2B, at least the tip portion 22d of the gripping portion 22b includes a main body 22b1 made of ceramics containing silicon carbide or zirconium oxide as a main component, and a first heat insulating layer 32 provided on an opposing surface 22g of the main body 22b1 that faces the outer periphery of the substrate W. The first heat insulating layer 32 has a lower thermal conductivity than the main body 22b1. By providing the first heat insulating layer 32 on the surface 22g facing the substrate W in this manner, the substrate W can be protected from the high-temperature mist of the cleaning liquid. W When cleaning the substrate W This reduces heat dissipation within the board W This reduces the temperature difference depending on the position inside the container, thereby reducing uneven cleaning. Here, the thermal conductivity of main body 22b1 is, for example, not less than 3 W / (m·K) and not more than 200 W / (m·K). The thermal conductivity of main body 22b1 may be determined in accordance with JIS R 1611:2010. If main body 22b1 is small and it is not possible to prepare a sample according to JIS R 1611:2010, at least a part of support portion 22a may be used as a sample for measuring thermal conductivity only if the ceramics forming main body 22b1 and support portion 22a have the same main component.

[0033] As shown in FIG. 2C, at least the tip 22d of the gripping portion 22b has a main body 22b at least on both sides of the opposing surface 22g. 1 It is preferable to provide a second heat insulating layer 33 having a lower thermal conductivity than the substrate. W This can further prevent the heat from dissipating from inside. The second heat insulating layer 33 may be provided on only one of the two side surfaces.

[0034] The first and second insulating layers 32 and 33 can be formed from the same or different main components. If they are formed from the same main component, it is desirable to form the first and second insulating layers 32 and 33 simultaneously.

[0035] As described above, the main body 22b1 is made of ceramics containing silicon carbide or zirconium oxide as a main component. In this specification, the term "major component of the ceramics" refers to a component that accounts for 80% by mass or more, and may particularly account for 90% by mass or more, of the total 100% by mass of the components that make up the ceramics. The constituent components can be identified using an X-ray diffractometer using CuKα radiation, and the content of each component can be determined using, for example, an ICP (Inductively Coupled Plasma) emission spectrometer or an X-ray fluorescence analyzer.

[0036] When the main body 22b1 is made of ceramics containing silicon carbide as a main component, it may contain boron and free carbon as other components.When the tip portion 22d is made of ceramics containing zirconium oxide as a main component, it may contain oxides of magnesium, silicon, and calcium as other components.

[0037] When at least the tip 22d of the gripping portion 22b is formed of ceramics mainly composed of silicon carbide or zirconium oxide, the obtained clamping jig 22 has excellent corrosion resistance and can be used for a long period of time even when an acid or alkali such as concentrated nitric acid or sodium hydroxide is used as a cleaning liquid for the substrate W.

[0038] The support portion 22a and the gripping portion 22b may be formed separately or integrally. In particular, if they are integrally formed, there is no risk of the support portion 22a and the gripping portion 22b separating from each other at the boundary between them, even if the substrate W is repeatedly clamped and cleaned, because there is no bonding layer made of glass or resin. "Integral formation" means that the clamping jig 22 is obtained as an integrally formed product by molding, cutting, firing, and grinding, rather than by joining the support portion 22a and the gripping portion 22b. Similarly, the base end portion 22c and the tip end portion 22d that constitute the grip portion 22b may be formed separately or integrally.

[0039] At least one of the first insulating layer 32 and the second insulating layer 33 preferably has a thermal conductivity of 1 W / (m·K) or less (excluding 0 W / (m·K)). As a result, as described above, heat within the substrate W is less likely to dissipate to the clamping jig 22, which promotes uniformity of the temperature within the substrate W. The thermal conductivity of each of the first and second insulating layers 32 and 33 can be determined as follows: The thermal diffusivity α of each of the first and second insulating layers 32 and 33 is measured using the flash method or a measurement method based on JIS R 1689:2018, "Determination of thermal diffusivity of fine ceramic films by pulsed light heating thermoreflectance method." The thermal conductivity of each of the first and second insulating layers 32 and 33 is calculated by multiplying the measured thermal diffusivity α by the respective specific heats S and densities D.

[0040] At least one of the first insulating layer 32 and the second insulating layer 33 preferably has a main component of DLC, zirconium oxide, or silicon nitride. All of these components have high corrosion resistance to concentrated nitric acid and sodium hydroxide, so they can be used for a long period of time even when exposed to cleaning solutions containing these. The first insulating layer 32 and the second insulating layer 33 can be formed by a plasma ion implantation method as described below, but can also be formed by a plasma CVD (chemical vapor deposition) method or the like. In this specification, the "main component of the first heat insulating layer 32" refers to a component having a wave number of 1500 to 1640 cm in a Raman spectrum when the main component of the first heat insulating layer 32 is DLC. -1 and the G band in the wavenumber range of 1300-1400 cm -1 In the Raman spectrum, the D band is observed in the range of 1500 to 1640 cm. -1 The strongest peak intensity among the peaks present in the HG spectrum is the peak with a wave number of 1300 to 1400 cm. -1 When the highest peak intensity among the peaks present in this range is defined as HD, it is preferable that HG>HD. If this relationship is satisfied, the density of the first heat insulating layer 32 can be maintained. The "main component of the first insulating layer 32" refers to a component that, when the main component of the first insulating layer 32 is zirconium oxide or silicon nitride, accounts for 80% by mass or more of the total 100% by mass of the components that make up the first insulating layer 32, and may particularly account for 90% by mass or more. When the main component of the first insulating layer 32 is zirconium oxide or silicon nitride, the content of each component can be determined using an ion scattering analyzer. The definition of the "main component of the second insulating layer 33" is the same as the definition of the "main component of the first insulating layer 32", and the method for determining the main component is also the same. In particular, when the main component of at least one of the first insulating layer 32 and the second insulating layer 33 is DLC, it is preferable that the layer contain at least one of hydrogen and silicon. The thermal conductivity of the first insulating layer 32 and the second insulating layer 33 can be adjusted by adjusting the content of hydrogen or silicon. Hydrogen and silicon can be added when the DLC film is produced by, for example, plasma ion implantation. The hydrogen content in the total 100 mass% of the components constituting the first insulating layer 32 should be between 20 at% and 30 at%. The silicon content in the total 100 mass% of the components constituting the first insulating layer 32 should be between 0.2 mass% and 4.5 mass%. The same applies to the second insulating layer 33. When the main component of the first thermal insulating layer 32 is DLC and contains at least one of hydrogen and silicon, the contents of these elements may be determined using an X-ray photoelectron spectrometer. When the main component of at least one of the first insulating layer 32 and the second insulating layer 33 is zirconium oxide, the thermal conductivity can be controlled by adjusting the density of each layer. To lower the thermal conductivity, the density of the layer can be reduced. When the main component of at least one of the first heat insulating layer 32 and the second heat insulating layer 33 is silicon nitride, the density may be adjusted. To determine density, first, an X-ray diffractometer is used to measure the intensity of reflected X-rays and incident X-rays. lineThe X-ray reflectivity is calculated from the intensity ratio to obtain an X-ray reflectivity curve, which can then be analyzed using thin film comprehensive analysis software (GlobalFit, manufactured by Rigaku Corporation) to determine the density.

[0041] At least one of the first insulating layer 32 and the second insulating layer 33 is preferably semiconductive. This allows the charge to gradually escape through the semiconductive layer even if a sudden electrostatic discharge occurs and current flows instantaneously toward the first insulating layer 32, making the gripping portion 22b less likely to be damaged. To impart semiconductivity to at least one of the first insulating layer 32 and the second insulating layer 33, when DLC is the main component, the graphite skeletal structure SP 2 Diamond framework structure SP for bonding 3 If zirconium oxide or silicon nitride is used as the main component, it is necessary to dope it with carbon or silicon so that the content of these elements contained in the total of 100 mass% of the components constituting the first insulating layer 32 is 0.2 mass% or more and 4.5 mass% or less. The same applies to the second insulating layer 33. In this specification, "semiconductive" means a material having a surface resistance of 10 4 ~10 11 The surface resistance value may be measured using, for example, a surface resistance meter (for example, Hioki E.E. Corporation, HiTester 3127-10).

[0042] 3A is a schematic enlarged cross-sectional view showing the boundary between the main body 22b1 and the first heat insulating layer 32. As shown in FIG. , Book body 22b1 teeth The surface facing the first heat insulating layer 32 has a recess 34 (first recess), The first insulating layer 32 isThe first insulating layer 32 has a first void 35a extending from the recess 34 in the thickness direction of the first insulating layer 32. The tip of the first void 35a is preferably closed within the first insulating layer 32. This makes it possible to suppress the accumulation of residual stress even when the temperature is repeatedly increased and decreased, and because the first void 35a does not communicate with the outside, particles within the first void 35a are not discharged to the outside of the first insulating layer 32. The first void 35a also improves the insulating effect of the first insulating layer 32.

[0043] Here, the recesses 34 refer to pores, grain boundary phases, etc. that open on the surface of the main body 22b1 facing the first heat insulating layer 32, and before the first heat insulating layer 32 is formed, the surface that forms the recesses 34 is part of the surface of the main body 22b1. 22b1 The surface of the film can be polished or the like. The first gap 35a can be formed, for example, when the first insulating layer 32 is formed on the opposing surface of the main body 22b1 by plasma ion implantation, plasma CVD, or the like. The width of the first gap 35a when viewed in cross section along the thickness direction of the first insulating layer 32 may be narrower on the surface side of the first insulating layer 32 than on the recess 34 side. In this configuration, even if the thickness of the first insulating layer 32 decreases as the substrate W is repeatedly gripped and the tip of the first gap 35a opens, particles in the first gap 35a are less likely to be discharged to the outside of the first insulating layer 32 than when the width of the surface side of the first insulating layer 32 is wider than that of the recess 34 side.

[0044] Also, as shown in Figure 3B , Book body 22b1 teeth On the surface facing the second heat insulating layer 33 too It has a recess 34 (second recess), The second heat insulating layer 33 isThe second insulating layer 33 has a second void 35b extending from the recess 34 in the thickness direction of the second insulating layer 33. The tip of the second void 35b is preferably closed within the second insulating layer 33. This allows the same effect as the first insulating layer 32 to be achieved. The relative density of the ceramic forming the main body 22b1 is preferably 96% or more and 99% or less, and particularly preferably 96.7% or more and 98.8% or less. This relative density is the percentage of the apparent density of the wear-resistant member relative to the theoretical density of the ceramic. The apparent density of the main body 22b1 may be determined in accordance with JIS R 1634:1998. When the main component of ceramics is silicon carbide and the other component is boron carbide, and the contents are a% by mass and b% by mass, respectively, the theoretical densities of silicon carbide and boron carbide (silicon carbide = 3.21 g / cm 3 , boron carbide=2.52g / cm 3 ) can be used to calculate the theoretical density (TD) of ceramics using the following formula (1). TD=1 / (0.01×(a / 3.21+b / 2.52))···(1) For example, when the content of the components constituting the ceramic is 99.6 mass% silicon carbide and 0.4 mass% boron carbide, the theoretical density (TD) of the ceramic is calculated using formula (1) as 3.21 g / cm 3 The percentage of the apparent density of a ceramic relative to this theoretical density (TD) is the relative density.

[0045] As shown in Figure 4, the main body 22b1 has a plurality of closed pores 40, and the value (C) obtained by subtracting the average circle-equivalent diameter (B) of the closed pores 40 from the average distance (A) between the centers of gravity of adjacent closed pores 40 is preferably 50 µm or more and 170 µm or less. That is, when the value (C) is 50 µm or more, the porosity decreases and rigidity improves, making the body less susceptible to bending. Furthermore, when the value (C) is 170 µm or less, the adjacent closed pores 40 enhance the heat insulating effect, and even if microcracks occur, the closed pores 40 suppress the progression of the microcracks, improving thermal shock resistance.

[0046] The circle-equivalent diameter of the closed pores 40 can be determined by the following method. Body 2 The cross section of 2b1 is polished (or etched after polishing, if necessary) and observed at a magnification of 200 times. For example, the area is 1.768 mm 2 An image of the area (1.36 mm horizontally and 1.3 mm vertically) is taken with a CCD camera to obtain an observation image. Image analysis software, such as "Azokun (ver. 2.52)" (registered trademark, manufactured by Asahi Kasei Engineering Co., Ltd.; hereafter, the image analysis software "Azokun" refers to the image analysis software manufactured by Asahi Kasei Engineering Co., Ltd.), can be used to determine the circle-equivalent diameter of each closed pore 40 in the observation image by a method called particle analysis. The setting conditions for this method are, for example, a threshold value (an index showing the brightness of the image) of 156, brightness of dark, and a small figure removal area of ​​20 μm. 2 The threshold value can be adjusted according to the brightness of the observed image, the brightness can be darkened, the binarization method can be set to manual, and the small figure removal area can be set to 20 μm 2 The threshold value may be adjusted so that the markers appearing in the observed image match the shape of the closed pores 40, with the noise reduction filter being disabled. The average circle-equivalent diameter of the closed pores 40 determined by the above-described method is, for example, 3 μm or more and 25 μm or less.

[0047] The distance between the centers of gravity of the closed pores 40 can be determined by the following method. The observation image taken to determine the equivalent circle diameter of the closed pores 40 can be used as the target to determine the distance between the centers of gravity of the closed pores 40 using image analysis software such as "A-Image-kun" and a method called the distance between the centers of gravity method for dispersity measurement. The setting conditions for this method are the same as those for determining the equivalent circle diameter of the closed pores 40. The average value of the distance between the centers of gravity of the closed pores 40 determined by the above-mentioned method is, for example, not less than 53 μm and not more than 195 μm.

[0048] Furthermore, the kurtosis Ku of the distance between the centers of gravity of the closed pores 40 is preferably 0.3 or more and 4 or less. That is, when the kurtosis Ku is 0.3 or more, the variation in the distance between the centers of gravity of the closed pores 40 is small, and therefore, there are fewer areas with locally poor mechanical properties. When the kurtosis Ku is 4 or less, there are no closed pores 40 that are extremely far from each other, and therefore, the thermal shock resistance is further improved.

[0049] Here, kurtosis Ku is an index (statistic) that indicates how much the peak and tails of a distribution differ from a normal distribution. When kurtosis Ku>0, the distribution has a sharp peak and long, thick tails; when kurtosis Ku=0, the distribution is normal; and when kurtosis Ku<0, the distribution has a rounded peak and short, thin tails. The kurtosis Ku of the circle-equivalent diameter of the closed pores 40 can be found using the function Kurt provided in Excel (registered trademark, Microsoft Corporation).

[0050] The first insulating layer 32 has a plurality of open holes 36, and it is preferable that the value (H) obtained by subtracting the average value (G) of the circle-equivalent diameters of the open holes 36 from the average value (F) of the distances between the centers of gravity of adjacent open holes 36 is greater than the above value (C). This results in the open holes 36 being sparsely scattered in the first insulating layer 32, making it possible to reduce particles generated from inside the open holes 36. Reducing the particles suppresses adhesion of particles to the substrate W. The difference between the value (H) and the value (C) is, for example, 2 μm or more and 10 μm or less. The distance between the centers of gravity and the circle-equivalent diameter of the open pores 36 included in the first heat insulating layer 32 can be determined by the following method. First, the surface of the first heat insulating layer 32 is observed at a magnification of 200 times using a digital microscope. 2 The area where the horizontal length is 1.36 mm and the vertical length is 1.3 mm is photographed with a CCD camera to obtain an observation image. The procedure thereafter is the same as that used to find the value (C).

[0051] Similarly to the first heat insulating layer 32, the second heat insulating layer 33 also has a plurality of open pores 36, and adjacent open pores36 The average value of the distance between the centers of gravity (J) of the open pores 36 It is preferable that the value (L) obtained by subtracting the average value (K) of the equivalent circle diameters from the value (C) is greater than the value (C). This provides the same effect as the first heat insulating layer 32. The difference between the value (J) and the value (C) is, for example, 2 μm or more and 10 μm or less. 36 The distance between the centers of gravity and the equivalent circle diameter can be determined by the following method: First, the surface of the second heat insulating layer 33 is observed at a magnification of 200 times using a digital microscope. 2 The area where the horizontal length is 1.36 mm and the vertical length is 1.3 mm is photographed with a CCD camera to obtain an observation image. The procedure thereafter is the same as that used to find the value (C). In addition, the open pores contained in the first insulating layer 32 and the second insulating layer 33 36 If the outline is difficult to distinguish, it may be polished by a few micrometers.

[0052] As shown in FIG. 4, main body 22b1 has coarse crystal particles 41 and fine crystal particles 42, each of which is mainly composed of silicon carbide. The average circle-equivalent diameter (M) of fine crystal particles 42 is smaller than the average circle-equivalent diameter (B) of closed pores 40. Coarse crystal particles 41 have an area of ​​1000 μm 2 The fine crystal particles 42 are crystal particles having an equivalent circle diameter of 8 μm or less. 2 It goes without saying that smaller crystal grains may be present. In particular, it is preferable that the difference between the average circle-equivalent diameter (M) of the fine crystal particles 42 and the average circle-equivalent diameter (B) of the closed pores 40 be 5 μm or more. The average circle-equivalent diameter (M) of the fine crystal particles 42 is, for example, 1 μm or more and 6 μm or less. The average circle-equivalent diameter (B) of the closed pores 40 is, for example, 8 μm or more and 30 μm or less. The circle-equivalent diameter of the fine crystal particles 42 is, for example, 2.67×10 -2 mm 2 The image was taken of an etched surface (191 μm horizontal length, 140 μm vertical length). analysisThe average diameter of the sample can be obtained by analyzing it using software (for example, Win ROOF, manufactured by Mitani Corporation). In the analysis, the threshold value of the equivalent circle diameter is set to 0.21 μm, and particle sizes less than 0.21 μm are not included in the calculation of the average equivalent circle diameter (B). Etching is carried out by immersing a sample of the sample, the surface of which has been polished in advance, in a heated and fused solution of sodium hydroxide and potassium nitrate in a mass ratio of 1:1. 22b1 The main body 22b1 is immersed in the solution for 20 seconds. The main body 22b1 has coarse crystal particles 41 in addition to fine crystal particles 42, and the area of ​​the coarse crystal particles 41 is preferably 6% by area or more and 15% by area or less. If the coarse crystal particles 41 account for 6% by area or more, even if fine cracks occur due to thermal shock, the coarse crystal particles 41 can suppress the crack propagation. If the coarse crystal particles 41 account for 15% by area or less, mechanical properties such as strength, rigidity, and fracture toughness can be improved.

[0053] The coarse-grained crystal particles 41 preferably contain intragranular pores 43. If the coarse-grained crystal particles 41 contain intragranular pores 43, the thermal stress generated in the coarse-grained crystal particles 41 in a high-temperature environment is more easily alleviated by the intragranular pores 43, thereby improving thermal shock resistance. Whether the coarse-grained crystal particles 41 contain intragranular pores 43 can be confirmed by observing the surface etched by the method described above. Main unit 22b1 Rough grain containing crystalline particles 41 and coarse grain When the crystalline grains 41 are observed on the etched surface, the etched surface has roughness. grain The cross section of the crystalline grain 41 is exposed. grain When the crystalline grains 41 contain intragranular pores 43, the intragranular pores 43 are not included in the roughness observed on the etched surface. grain Since the intragranular pores 43 are observed as depressions in the crystalline grains 41, it is possible to distinguish between the intragranular pores 43, which are depressions, and the rest of the grains. When the etched surface is observed with an optical microscope, the intragranular pores 43 are observed to be darker or recessed than the areas other than the intragranular pores 43, so that the intragranular pores 43 can be confirmed.

[0054] Next, an example of a method for manufacturing the clamping jig 22 according to the present disclosure will be described. In the following description, it is assumed that the support portion 22a, the grip portion 22b, and the base portion 22e are integrally formed with the main body 22b1 made of ceramics containing silicon carbide or zirconium oxide as a main component.

[0055] First, granules containing silicon carbide as a main component are prepared, for example, by the following procedure: Coarse powder and fine powder are prepared as silicon carbide powder, and ion-exchanged water and, if necessary, a dispersant are added to the powder, and the powder is pulverized and mixed in a ball mill or a bead mill for 40 to 60 hours to form a slurry. 22b1 To make the area of ​​the coarse crystal particles 41 contained in the powder 6% by area or more and 15% by area or less, 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. The particle sizes of the fine powder and the coarse powder after pulverization and mixing are in the ranges of 0.4 μm to 4 μm and 11 μm to 34 μm, respectively. To obtain a clamping jig 22 in which the coarse-grained crystal particles 41 contain intragranular pores 43, it is sufficient to use a coarse-grained powder that contains voids in advance.

[0056] Next, the resulting slurry is mixed with a sintering aid consisting of boron carbide powder and amorphous carbon powder or phenolic resin, and a binder, and then spray-dried to obtain granules whose main component is silicon carbide. Examples of binders include acrylic emulsion, polyvinyl alcohol, polyethylene glycol, and polyethylene oxide. To obtain a clamping jig 22 in which the first insulating layer 32 has a first void 35a and the tip of the first void 35a is closed within the first insulating layer 32, a hydrophobic pore-forming agent made of resin beads and a pore-dispersing agent for dispersing the pore-forming agent are added to the slurry together with a binder, and the body after sintering is formed. 22b1 On the opposite side of , forming a recess 34 It is sufficient to make it easier for open pores to exist in advance. To obtain a clamping jig 22 having the value (C) of 50 μm or more and 170 μm or less, for example, the content of the pore-forming agent is set to 1.2 parts by mass or more and 1.38 parts by mass or less with respect to 100 parts by mass of silicon carbide powder, and the average particle size (D 50 ) may be set to 36 μm or more and 45 μm or less, particularly 40 μm or more and 45 μm or less. In order to obtain a clamping jig 22 in which the kurtosis Ku of the distance between the centers of gravity of the closed pores 40 is 0.3 or more and 4 or less, the average particle diameter (D 50 ) may be, for example, 42.5 μm or more and 44.5 μm or less. The pore dispersant disperses the pore-forming agent and is, for example, an anionic surfactant such as a carboxylate, a sulfonate, a sulfate, or a phosphate. The anionic surfactant adsorbs to the pore-forming agent, allowing the pore-forming agent to easily wet and penetrate into the slurry. Furthermore, the charge repulsion of the hydrophilic groups in the anionic surfactant further suppresses aggregation of the pore-forming agent, allowing the pore-forming agent to be sufficiently dispersed in the slurry without aggregation. The anionic surfactant is highly effective in wetting and penetrating the pore-forming agent into the slurry. The pore dispersant may be added in an amount of 0.14 parts by mass or more and 0.24 parts by mass or less per 100 parts by mass of the pore-forming agent.

[0057] The resulting granules are then filled into a mold and subjected to a pressure of, for example, 49 MPa to 147 MPa. below The compact is then degreased at 400 to 600°C, and the degreased body is held in a reduced pressure atmosphere of an inert gas such as argon at a temperature of 1800 to 2200°C for 3 to 6 hours to obtain a sintered body.

[0058] Next, the resulting sintered body is polished at a portion of the tip portion 22d corresponding to the opposing surface 22g of the main body 22b1. Examples of polishing include buffing. The base material for the buff is not limited, and examples include felt, a cotton strip, and a cotton strip. Examples of abrasives include diamond powder and green carborundum (GC) powder. These abrasives may be added to oils and fats and used in a paste state.

[0059] 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 the rotation speed is, for example, 28 m / min or more and 170 m / min or less. The polishing time is, for example, 0.5 minutes or more and 5 minutes or less.

[0060] Next, in the polished sintered body, a first heat insulating layer 32 is formed on a portion of the main body 22b1 corresponding to the surface 22g facing the substrate W. When the first heat insulating layer 32 is mainly composed of DLC, it is formed, for example, by the following procedure.

[0061] First, a sintered body is placed in a predetermined position in a plasma processing chamber. After evacuation, the sintered body is heated to 100°C to 450°C in a non-oxidizing gas atmosphere, such as argon gas or nitrogen gas, or in a high vacuum. Next, high-frequency power and a negative bias voltage are applied to the sintered body in a non-oxidizing gas atmosphere or an inert gas atmosphere to generate a discharge plasma, and ion beams are irradiated onto the portion of the main body 221b corresponding to the facing surface 22g. This ion beam removes any oxide film or deposits from the portion of the main body 221b corresponding to the facing surface 22g. Next, a DLC film-forming source gas is supplied into the plasma processing chamber to generate a discharge plasma, forming a first insulating layer 32, primarily composed of DLC, on the portion of the main body 221b corresponding to the facing surface 22g. The DLC film-forming source gas is, for example, a hydrocarbon gas, such as methane, acetylene, or toluene, with hydrogen added as needed. A second insulating layer 33 may be formed simultaneously with the first insulating layer 32. To obtain a clamping jig 22 having a value (H) or a value (L) greater than the value (C), the first insulating layer 32 and By increasing the density of the heat insulating layer 33, 22g Open pores above 36 The density is negatively correlated with the strength ratio (HD / HG), so the opposing surfaces should be filled with DLC to reduce the strength ratio (HD / HG). 22g The film forming conditions may be adjusted so that the peripheral plasma density becomes high.

[0062] When the first heat insulating layer 32 and / or the second heat insulating layer 33 are made mainly of zirconium oxide or silicon nitride instead of DLC, they may be formed by a CVD (chemical vapor deposition) process.

[0063] When the main body 22b1 of the clamping jig 22 of the present disclosure is formed from ceramics containing zirconium oxide as a main component, the zirconium oxide powder may be a mixed powder consisting of 88 to 99 mol % zirconium oxide powder and 1 to 12 mol % of at least one stabilizer powder selected from yttrium oxide (Y2O3), cerium oxide (CeO2), magnesium oxide (MgO), neodymium oxide (Nd2O3), dysprosium oxide (Dy2O3), and calcium oxide (CaO), or zirconium oxide powder produced by co-precipitation with the addition of a stabilizer. The weighed powders and water as a solvent are then mixed and pulverized in a vibrating mill, bead mill, sand mill, agitator mill, ball mill, etc. to obtain a slurry. Next, a predetermined amount of binder is added to the slurry, which is then dried using a spray dryer to obtain granules. The granules are filled into a mold, and a green compact is obtained in the same manner as described above. This green compact is then degreased and fired to obtain a sintered body. Specifically, firing is performed in an air atmosphere at a temperature of 1350°C to 1550°C for 3 to 6 hours. Next, in the same manner as described above, a first insulating layer 32 is formed on the portion of the main body 22b1 corresponding to the surface 22g facing the substrate W, and a second insulating layer 33 is further formed on the side surface.

[0064] The clamping jig 22 obtained by the above-described manufacturing method is made of ceramics with excellent corrosion resistance. Therefore, the clamping jig 22 according to the present disclosure can be used continuously for a long period of time, for example, as a component of a cleaning device 30. Furthermore, at least the tip 22d of the gripping portion 22b of the clamping jig 22 is provided with the first heat insulating layer 32 on the facing surface 22g facing the outer periphery of the substrate W, so that the temperature difference depending on the position within the substrate W is small, and uneven cleaning occurring on the surface of the substrate W can be reduced.

[0065] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the present disclosure. [Explanation of symbols]

[0066] 1. Housing 2 chambers 3 First window 4 First shutter 5 Transfer arm 6 Second window section 7 Second shutter 8 Rotating Chuck 9 Gas supply section 10 Processing Cups 10a Drain 11 Underplate 12 Rotating Plate 13 Cylinder 14 Belt 15 First motor 16 Top Plate 17 Second Axial Body 18 Second horizontal plate 19 Second motor 20 Second lifting mechanism 21 Second Flow Path 22 Clamping jig 22a Strut part 22b Grip part 22b1 main body 22c Proximal end 22d Tip 22e base 22f through hole 22g opposing surface 22j connection surface 23 First Channel 24 First axis 25 1st horizontal plate 26 First lifting mechanism 27 Pressing member 28 Spring 29 Third Axial Body 30 Cleaning equipment 32 First insulation layer 33 Second insulation layer 34 Recess 35a 1st cavity 35b 2nd cavity 36 Open pores 40 Closed pores 41 Coarse grained crystal particles 42 Fine crystalline particles 43 Intragranular pores W substrate

Claims

1. A support portion; a gripping portion located at one end of the support portion for gripping an outer periphery of the substrate; a base portion located at the other end of the support column portion for supporting the support column portion, the gripping portion includes a main body made of ceramics containing silicon carbide or zirconium oxide as a main component, and a first heat insulating layer located at a tip of the main body and having a thermal conductivity lower than that of the main body; the main body has a first recess on a surface facing the first insulating layer, the first heat insulating layer includes a first gap portion extending from the first recess in a thickness direction, The tip of the first gap is closed within the first heat insulating layer. Clamping jig.

2. The clamping jig according to claim 1 , further comprising a second heat insulating layer having a lower thermal conductivity than the main body, at least on the opposing surface of either side of the gripping portion.

3. The clamping jig according to claim 2 , wherein at least one of the first insulating layer and the second insulating layer has a thermal conductivity greater than 0 W / (m·K) and equal to or less than 1 W / (m·K).

4. 4. The clamping jig according to claim 2, wherein at least one of the first heat insulating layer and the second heat insulating layer is mainly composed of DLC, zirconium oxide or silicon nitride.

5. 4. The clamping jig according to claim 2, wherein at least one of the first heat insulating layer and the second heat insulating layer is mainly composed of DLC and contains at least one of hydrogen and silicon.

6. The clamping jig according to claim 2 or 3, wherein at least one of the first insulating layer and the second insulating layer is semiconductive.

7. A clamping jig as described in claim 2 or 3, wherein the side has a second recess, the second insulating layer has a second void portion extending in the thickness direction from the second recess, and the tip of the second void portion is blocked within the second insulating layer.

8. A support portion, a gripping portion located at one end of the support portion for gripping an outer periphery of the substrate; a base portion located at the other end of the support column portion for supporting the support column portion, The gripping portion includes a main body made of ceramics containing silicon carbide or zirconium oxide as a main component, and a first insulating layer located at the tip of the main body and having a thermal conductivity lower than that of the main body, the main body having a plurality of closed pores, and a value (C) obtained by subtracting an average value (B) of the circle-equivalent diameters of the closed pores from an average value (A) of the distances between the centers of gravity of adjacent closed pores is 50 μm or more and 170 μm or less. Clamping jig.

9. 4. The clamping jig according to claim 2 or 3, wherein the main body has a plurality of closed pores, and a value (C) obtained by subtracting an average value (B) of the circle-equivalent diameters of the closed pores from an average value (A) of the distances between the centers of gravity of adjacent closed pores is 50 μm or more and 170 μm or less.

10. The clamping jig according to claim 9 , wherein the kurtosis Ku of the distance between the centers of gravity of the closed pores is 0.3 or more and 4 or less.

11. 4. The clamping jig according to claim 1, wherein the main body has coarse crystal grains, and the area of ​​the coarse crystal grains is 6% by area or more and 15% by area or less.

12. The clamping jig of claim 11 , wherein the coarse-grained crystalline grains include intragranular porosity.

13. The clamping jig of claim 9, wherein the first insulating layer has a plurality of open holes, and the value (H) obtained by subtracting the average value (G) of the circle equivalent diameters of the open holes from the average value (F) of the distances between the centers of gravity of adjacent open holes is greater than the value (C).

14. The clamping jig of claim 9, wherein the second insulating layer has a plurality of open holes, and the value (L) obtained by subtracting the average value (K) of the circle equivalent diameters of the open holes from the average value (J) of the distances between the centers of gravity of adjacent open holes is greater than the value (C).

15. A cleaning device comprising the clamping jig according to any one of claims 1 to 3.

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