TWI798859B - Clamping jig, manufacturing method of clamping jig, and cleaning apparatus - Google Patents

Abstract

A clamping jig disclosed in the present invention includes a pillar part, a holding part located at one end of the pillar part and used for holding an outer peripheral of a substrate, and a base part located at the other end of the pillar part and used for supporting the pillar part. At least the base part includes a ceramic containing silicon carbide as a main component. In the base part, carbon existing on the upper main surface is less than carbon existing on the parts other than the upper main surface.

Description

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

The invention relates to a fixture (jig, also known as an auxiliary tool) for clamping and a cleaning device.

Conventionally, in order to remove particles, organic pollutants, metal impurities and other pollutants adhering to the semiconductor substrate, polymers after etching, etc., a cleaning solution for cleaning the semiconductor substrate with a predetermined chemical solution, pure water or other cleaning solution is used. net device.

Regarding a liquid processing device including such a cleaning device, Patent Document 1 discloses a liquid processing device including a holding mechanism for holding a substrate horizontally, and the holding mechanism has claws for holding an end surface of the substrate. In addition, regarding the holding mechanism for holding the substrate horizontally, Patent Document 2 discloses a holder that presses the substrate from above, and discloses that the material of the holder is silicon carbide.

[Prior Art Literature]

[Patent Document]

[Patent Document 1] Japanese Patent Publication No. 5726686

[Patent Document 2] Japanese Patent Laid-Open Publication No. Hei 4-130627

When the holding portion of the holding mechanism described in Patent Document 1 is formed of ceramics mainly composed of silicon carbide, the following problems arise. That is, if for a long time repeatedly use fluorine-containing acids such as hydrofluoric acid and hypofluorous acid to clean objects to be cleaned such as semiconductor substrates, fluorine will be fixed to the carbon on the surface (main surface) of the clamping jig and There is a problem that the appearance of the clamping jig deteriorates due to the whitening phenomenon.

The object of the present invention is to provide a jig for clamping, even if the object to be cleaned is repeatedly washed with fluorine-containing acids such as hydrofluoric acid and hypofluorous acid for a long time, the surface is difficult to whiten.

The jig for clamping disclosed in the present invention comprises: a pillar part; a gripping part located at one end of the pillar part for holding the outer periphery of the substrate; and a base part located at the other end of the pillar part for supporting the pillar department. At least the base includes ceramics mainly composed of silicon carbide. In the base portion, carbon existing on the upper main surface is smaller than carbon existing on parts other than the upper main surface.

The manufacturing method of the clamping jig disclosed in the present invention includes: the step of filling the particles mainly composed of silicon carbide in a forming mold and forming it to obtain a shaped body; the step of cutting the shaped body to obtain a precursor; firing The step of obtaining a sintered body from the precursor; and the step of heat-treating the sintered body at a temperature of not less than 300°C and not more than 750°C in an air environment.

Furthermore, the cleaning device disclosed in the present invention includes the above-mentioned jig for clamping.

As described above, the clamping jig disclosed in the present invention has less carbon present on the upper main surface of the base than carbon present in parts other than the upper main surface of the base. As a result, according to the jig disclosed by the present invention, even if the object to be cleaned is washed with fluorine-containing acids such as hydrofluoric acid and hypofluorous acid repeatedly for a long time, it is easy to expose It is also difficult to cause whitening on the upper main surface of the base of fluorine-containing acids. Therefore, the jig for clamping disclosed by the present invention can reduce the deterioration of the appearance and can be used for a long time.

1: Shell

2: chamber

3: The first window

4: The first gate

5: Transfer arm

6: Second window

7:Second gate

8: Swivel clamp

9: Gas supply part

10: Disposal Cup

10a: Emission Department

11: Lower side panel

12:Rotating board

13: Cylindrical body

14: belt body

15: Motor

16: Upper side panel

17: Second axis body

18: Second horizontal board

19: motor

20: The second lifting mechanism

21: Second flow path

22: Fixture for clamping

22a: pillar part

22b: control part

22c: base

22c’: upper main surface

23: The first channel

24: The first axis body

25: Horizontal board

26: The first lifting mechanism

30: Cleaning device

D: Arrow

W: Substrate

Fig. 1 is a schematic diagram showing a schematic configuration of a cleaning device equipped with a clamping jig according to an embodiment of the present invention.

Fig. 2 is an enlarged view showing a clamping jig according to an embodiment of the present invention.

The jig for clamping disclosed by the present invention will be described in detail below based on FIG. 1 and FIG. 2 . FIG. 1 is a schematic diagram showing a schematic configuration of a cleaning device 30 equipped with a clamping jig 22 according to an embodiment of the present invention.

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

The casing 1 has a first window portion 3 for carrying the substrate W into the casing 1 and carrying the substrate W out of the casing 1 . The first window portion 3 is opened and closed by the first shutter 4 . The transport arm 5 places the substrate W, and carries the substrate W into the housing 1 or out of the housing 1 through the first window portion 3 . The first window 3 is closed by the first shutter 4 when the substrate W is not being loaded or unloaded. The first shutter 4 is provided inside the housing 1 to open and close the first window 3 from the inside of the housing 1 .

The chamber 2 has a second window portion 6 for carrying the substrate W into the chamber 2 and carrying the substrate W out of the chamber 2 . The second window portion 6 is opened and closed by the second shutter 7 . The transfer arm 5 is provided so as to enter or exit the chamber 2 through the second window portion 6 , and transfers the substrate W to the spin chuck 8 provided inside the chamber 2 . The second shutter 7 is provided inside the chamber 2 to open and close the second window 6 from the inside of the chamber 2 .

A gas supply unit 9 for supplying a dry gas such as nitrogen gas into the chamber 2 is provided on the ceiling of the chamber 2 . The gas supply unit 9 supplies the drying gas downward so as to prevent the cleaning solution (for example, fluorine-containing acids such as hydrofluoric acid and hypofluorous acid) supplied to the substrate W held by the spin clamp 8 from evaporating and filling the chamber 2 . If the drying gas is supplied downward, liquid stains which are pollutants are less likely to be generated on the surface of the substrate W. FIG.

The chamber 2 is provided with a processing cup 10 , a rotary holder 8 , a lower side plate 11 and an upper side plate 16 . The processing cup 10 accommodates the substrate W. As shown in FIG. The spin chuck 8 holds the substrate W in the processing cup 10 . The lower side plate 11 is located at a position isolated from the back surface of the substrate W. As shown in FIG. The upper side plate 16 is located at a position isolated from the front surface of the substrate W. As shown in FIG.

The processing cup 10 is provided with an inclined part at the upper part and provided with the discharge part 10a at the bottom. The upper portion of the processing cup 10 forming the inclined portion is located above the substrate W held by the spin chuck 8 (the position shown by the solid line in FIG. 1. It may also be referred to as the "processing position" below), And its upper part is lower than the position of the substrate W held by the rotary chuck 8 (the position shown by the two-point chain line in FIG. 1. Hereinafter, it may also be referred to as the "retreat position") between them.

When transferring the substrate W between the transfer arm 5 and the spin clamp 8 , the processing cup 10 is held at a retracted position where the transfer arm 5 does not interfere with entry and exit. On the other hand, when the substrate W held by the spin chuck 8 is to be cleaned, the processing cup 10 is held at the processing position. 10 series of treatment cups held in the treatment position The cleaning liquid supplied to the substrate W is prevented from being scattered around, and the cleaning liquid used to clean the substrate W is guided to the discharge part 10a.

The discharge part 10a is connected to a cleaning liquid recovery pipe and an exhaust pipe (both not shown). The discharge unit 10 a is provided to discard the atomized fine particle droplets and the like generated in the processing cup 10 and recover the cleaning solution in the chamber 2 .

The rotary clamp 8 has a rotary plate 12 and a cylindrical body 13 . The rotating plate 12 is in the shape of a disc. The cylinder body 13 is connected with the rotating plate 12 and has a cylindrical shape. A holder (not shown) for supporting the substrate W and a chucking jig 22 for fixing the substrate W are attached to the outer peripheral portion of the rotating plate 12 . The holders are arranged at least three places at equal intervals along the circumferential direction, and support the substrate W from the reverse side of the substrate W.

The clamping jigs 22 are arranged at least three places at equal intervals along the circumferential direction, and fix the substrate W from the outer peripheral surface side of the substrate W. As shown in FIG. A belt 14 is wound around the outer peripheral surface of the cylindrical body 13 . The belt body 14 is driven by the motor 15 to rotate the cylindrical body 13 and the rotating plate 12 , thereby rotating the substrate W fixed by the clamping jig 22 .

The lower side plate 11 is connected to the first shaft body 24 penetrating through the central portion of the rotating plate 12 and the cylindrical body 13 . The first shaft body 24 is fixed on the horizontal plate 25, and the horizontal plate 25 is arranged so as to be able to lift together with the first shaft body 24 through a first lifting mechanism 26 such as an air cylinder. The lower plate 11 and the first shaft body 24 are provided with a first flow path 23 for supplying cleaning liquid and drying gas to the substrate W. As shown in FIG.

The disc-shaped upper side plate 16 located near the top plate of the chamber 2 is connected to the lower end of the cylindrical second shaft body 17 . The upper side plate 16 is provided so as to be rotatable by a motor 19 provided on the horizontal plate 18 . The second shaft body 17 is rotatably supported on the lower surface of the second horizontal plate 18 . The second horizontal plate 18 can be vertically moved up and down by a second lifting mechanism 20 such as an air cylinder fixed to the ceiling of the chamber 2 . The upper side plate 16 and the second shaft body 17 are respectively provided with a second flow path 21 along the axial direction for supplying cleaning liquid and drying gas.

When the substrate W is transferred between the spin chuck 8 and the transfer arm 5 , the upper side plate 16 is held at a position close to the top plate of the chamber 2 so as not to collide with the transfer arm 5 . When the front (upper surface) of the substrate W is to be cleaned, the upper side plate 16 is lowered to a position close to the front of the substrate W held by the jig 22 for clamping, and the cleaning liquid is supplied to the substrate W through the second flow path 21. wait.

When the front and back surfaces (upper and lower surfaces) of the substrate W are to be cleaned at the same time, the front surface of the substrate W is cleaned as described above, and the back surface of the substrate W is cleaned using the lower plate 11 and the first flow path 23 . As a method of cleaning the back surface of the substrate W, the following methods are exemplified. First, the lower side plate 11 is brought close to the back surface of the substrate W. As shown in FIG. Next, a cleaning liquid is supplied from the first flow path 23 between the substrate W and the lower plate 11 to form a cleaning liquid layer, which is maintained for a predetermined time to perform cleaning liquid treatment. Next, pure water or the like is supplied from the first flow path 23 between the substrate W and the lower plate 11 to cause the chemical solution to flow out to perform a rinse process. Next, while supplying dry gas from the first flow path 23 between the substrate W and the lower plate 11 , the substrate W is rotated at a high speed.

Examples of the cleaning solution include fluorine-containing acids such as hydrofluoric acid and hypofluorous acid.

After holding the substrate W on the jig 22 for chucking, the substrate W is cleaned. At this time, after the processing cup 10 is raised, the used chemical solution, pure water, etc. are discharged from the discharge part 10a.

After the cleaning of the substrate W is completed, the processing cup 10 and the lower plate 11 are lowered. With the upper plate 16 raised, the substrate W is transferred from the holding jig 22 to the holder. Then, the first gate 4 and the second gate 7 are opened, and the transfer arm 5 enters the chamber 2 . In this state, the substrate W is transferred from the spin chuck 8 to the transfer arm 5 by the reverse procedure of the transfer of the substrate W from the transfer arm 5 to the spin chuck 8 described earlier, and the substrate W is transferred from the cleaning to the transfer arm 5 . The device 30 is moved out.

Next, the clamping jig 22 according to one embodiment of the present invention will be described. As shown in FIG. 2 , the clamping jig 22 includes a pillar portion 22a, a grip portion 22b, and a base portion 22c. The gripping portion 22b for gripping the outer peripheral portion of the substrate is located at one end of the pillar portion 22a. The base 22c for supporting the pillar is located at the other end of the pillar 22a.

The pillar part 22a is a member for connecting the grip part 22b and the base part 22c mentioned later, and is formed of ceramics, for example. The ceramics are not limited, and examples thereof include ceramics mainly composed of silicon carbide, ceramics mainly composed of boron carbide, and ceramics mainly composed of alumina.

The "main component" in this specification means a component accounting for 80% by mass or more of the total 100% by mass of components constituting ceramics when the main component is silicon carbide or boron carbide. When the main component is alumina, it means a component accounting for 99.6% by mass or more in a total of 100% by mass of components constituting ceramics.

When the pillar portion 22a is formed of ceramics mainly composed of silicon carbide, other components may include boron, free carbon, and the like. When the pillar portion 22a is formed of ceramics mainly composed of alumina, other components may include oxides of magnesium, silicon, and calcium.

Components constituting ceramics can be identified by an X-ray diffraction device using CuKα rays. The content of each component can be obtained by, for example, an inductively coupled plasma (Inductively Coupled Plasma; ICP) emission spectrometer or a fluorescent X-ray analyzer.

The holding part 22b is a member for holding the outer peripheral part of the board|substrate W. As shown in FIG. The grip part 22b is located at one end of the pillar part 22a. The holding part 22b is formed of ceramics, for example. The ceramics are not limited, and examples thereof include ceramics mainly composed of silicon carbide, ceramics mainly composed of boron carbide, and ceramics mainly composed of alumina.

When the holding portion 22b is formed of ceramics mainly composed of silicon carbide, other components may include boron, free carbon, and the like. When the holding portion 22b is formed of ceramics mainly composed of boron carbide, other components may include Iron, aluminum, silicon, yttrium, etc. When the holding portion 22b is formed of ceramics mainly composed of alumina, other components may include oxides of magnesium, silicon, and calcium.

Although not specifically shown in FIG. 2 , the holding portion 22 b is processed into a shape that facilitates holding the outer peripheral portion of the substrate W. As shown in FIG. Specifically, the grasping portion 22b is formed with slits, grooves, and the like.

The base portion 22c is located at the other end of the pillar portion 22a, that is, at a position facing the grip portion 22b. The base portion 22c is formed of ceramics mainly composed of silicon carbide. The ceramics forming the base portion 22c may include, for example, boron, free carbon, etc. in addition to silicon carbide.

In the base portion 22c formed of ceramics mainly composed of silicon carbide, the amount of carbon existing on the upper principal surface 22c' is smaller than the carbon existing on portions other than the upper principal surface 22c'. Therefore, even if fluorine-containing acids such as hydrofluoric acid and hypofluoro acid are repeatedly used to clean the object to be cleaned for a long time, the upper main surface of the base that is easily exposed to fluorine-containing acids is difficult to cause whitening. That is, the fixation of fluorine, which has a high covalent bonding energy with carbon, can be suppressed, so that the whitening phenomenon hardly occurs. As a result, the jig for clamping disclosed by the present invention can reduce the deterioration of appearance and can be used for a long time.

On the other hand, on the surface other than the upper main surface 22c', for example, the carbon system present on the lower main surface is more than the carbon existing on the upper main surface 22c'. Therefore, the surfaces other than the upper main surface 22c' can maintain the inherent semiconducting properties of silicon carbide (for example, the surface resistance value is 10 ⁴ to 10 ¹¹ Ω), and the adsorption of particles floating in the space can be suppressed.

The upper main surface 22c' may include at least one of silicon oxide, silicon oxycarbide (SiCO), and silicon oxycarbonitride (SiCON). These compounds may also exist dispersedly on the upper main surface 22c'. When the upper main surface 22c' includes silicon oxycarbide (SiCO) or silicon oxycarbonitride (SiCON), these compounds may also be layered. When the upper main surface 22c' is made of silicon oxycarbide (SiCO), its composition formula can be expressed as, for example, SiC _{1 -x} O _x (x=0.1 to 0.9).

In this specification, "the upper main surface of the base" refers to a region within 0.5 mm from the surface in the depth direction (direction of arrow D in FIG. 2 ).

In the upper main surface 22c' of the base portion 22c, there is no limitation as long as the content of carbon is less than the portion other than the upper main surface 22c'. In order to further suppress the fixation of fluorine and make the whitening less likely to occur, the ratio (R ₁ ) of the count value of carbon to the count value of silicon is preferably 0.004 or less. This ratio (R ₁ ) is the ratio of the count value of carbon to the count value of silicon when the element mapping (Mapping) analysis is performed with an electron microprobe analyzer (Electron Probe Micro Analyzer).

On the other hand, the ratio _R2 of the count value of carbon to the count value of silicon on surfaces other than the upper main surface 22c' is preferably 0.0045 or more, and the difference between the ratio (R ₁ ) and the ratio (R ₂ ) is preferably 0.0005 or more. good. The ratio _R2 of the surface other than the upper main surface 22c' may be, for example, _R2 of the lower main surface of the base 22c, or the area of the side surface of the base 22c other than the area within 0.5 mm from the upper end. The ratio R ₂ .

Elemental mapping analysis with electron microprobe analyzer is a method of elemental analysis by energy dispersive X-ray spectroscopy (EDS). Specifically, by the ZAF correction method of the peak intensity of elements detected in a predetermined analysis range (for example, a range of 1500 times) by a scanning electron microscope (SEM), the total concentration becomes 100%. A method of calculating the ratio of a predetermined element to the element of the main component by semi-quantitative analysis approximately calculated by the method. The accelerating voltage used in elemental mapping was 15kV.

In the base portion 22c, there is no particular limitation on the cross-sectional degree difference (Rδc) of the upper main surface 22c′, and the cross-sectional degree difference (Rδc) represents 25% of the load in the roughness curve of the upper main surface 22c′ of the base portion 22c. The difference between the cut level of the length ratio and the cut level of the 75% load length ratio in the roughness curve. From the point of view of further suppressing the adhesion of dirt, and further suppressing the fixation of fluorine, it is difficult to occur From the viewpoint of the whitening phenomenon, the cross-sectional degree difference (Rδc) of the upper main surface 22c' is preferably not less than 0.17 μm and not more than 0.38 μm.

When the cross-sectional degree difference (Rδc) of the upper main surface 22c' is 0.17 µm or more, the contact angle between the upper main surface 22c' and pure water becomes small and exhibits hydrophilicity. Therefore, when washing with pure water or the like after washing with fluorine-containing acids, adhesion of air bubbles can be reduced. As a result, since the adhesion of air bubbles can be reduced, the adhesion of dirt contained in the air bubbles can be suppressed. On the other hand, when the cross-sectional degree difference (Rδc) of the upper main surface 22c' is 0.38 μm or less, the anchoring effect of fluorine on the upper main surface 22c' can be reduced. As a result, the fixation of fluorine can be further suppressed and the whitening phenomenon is more difficult to occur.

In the base portion 22c, the root mean square slope (RΔq) in the roughness curve of the upper main surface 22c' is not particularly limited. From the viewpoint of further suppressing the adhesion of dirt and the viewpoint of further suppressing the fixation of fluorine to prevent whitening, the root mean square slope (RΔq) of the upper main surface 22c' is 0.18 to 0.5. good.

When the root-mean-square slope (RΔq) of the upper main surface 22c' is 0.18 or more, the contact angle between the upper main surface 22c' and pure water becomes small and exhibits hydrophilicity. Therefore, when washing with pure water or the like after washing with fluorine-containing acids, adhesion of air bubbles can be reduced. As a result, since the adhesion of air bubbles can be reduced, the adhesion of dirt contained in the air bubbles can be suppressed. On the other hand, when the root mean square slope (RΔq) of the upper main surface 22c' is 0.5 or less, the anchoring effect of fluorine on the upper main surface 22c' can be reduced. As a result, the fixation of fluorine can be further suppressed and the whitening phenomenon is more difficult to occur.

For the degree of cross section difference (Rδc) and the root mean square slope (R△q), a laser microscope (manufactured by Keyence Co., Ltd., ultra-deep color 3D shape measurement microscope (VK-X1000 or its successor)) can be used , measured according to Japanese Industrial Standard JIS B 0601:2001. As far as the measurement conditions are concerned, the illumination method can be set to coaxial illumination, the measurement magnification can be set to 480 times, and the cut-off value λs can be set to "None". Set the cutoff value λc to 0.08mm, set the terminal effect correction to "Yes", and set the size of the measurement range at one point to 710μm× 533μm and set the measurement range.

Then, four lines to be measured were marked at approximately equal intervals in each measurement range, and the surface roughness was measured. The length of one of the lines to be measured is 560 μm and may be measured along the short-side direction of the base portion 22 c.

One embodiment of the jig 22 for clamping can be obtained by forming the pillar part 22a, the grip part 22b, and the base part 22c separately and then joining them together. Alternatively, at least two of the pillar portion 22a, the grip portion 22b, and the base portion 22c may be integrally formed as an integral product. In the case of an integrally formed product, since there is no bonding layer, separation does not occur at the bonding layer as a boundary. In particular, an integrally formed product in which the pillar portion 22a, the grip portion 22b, and the base portion 22c are all integrally formed is preferable.

The relative density of the ceramic mainly composed of silicon carbide contained in the base portion 22c is, for example, 95% or more. This relative density is the percentage of the apparent density of ceramics obtained based on JIS R 1634:1998 with respect to the theoretical density of ceramics. As far as the theoretical density of ceramics is concerned, the content of each component that constitutes ceramics is obtained by using an inductively coupled plasma (Inductively Coupled Plasma; ICP) emission spectrum analysis device or a fluorescent X-ray analysis device. CuK _α- ray X-ray diffraction method to identify. If the identified components are SiC and B ₄ C, they are converted into SiC and B ₄ C using the values of the Si and B contents obtained by an ICP spectrometer or a fluorescent X-ray analyzer.

At least the upper main surface 22c' of the base portion 22c includes, for example, coarse silicon carbide particles with an area of 170 μm ² or more and fine silicon carbide particles with a crystal grain size of 8 μm or less. Here, it goes without saying that there may be silicon carbide particles with a crystal grain size exceeding 8 μm and an area of less than 170 μm ² .

Moreover, if at least the upper main surface 22c' of the base 22c contains coarse-grained silicon carbide particles with an area of 6 area % to 15 area % and an area of 170 μm ^or more, even if the upper main surface 22c is damaged due to thermal shock or mechanical shock, Fine cracks can be generated inside, and the progress of cracks can also be suppressed by coarse-grained silicon carbide particles, thus improving mechanical properties such as strength and rigidity, and thermal shock resistance.

The coarse silicon carbide particles may include at least one of open pores and closed pores. If the coarse-grained silicon carbide particles include at least one of open pores and closed pores, even if fine cracks are generated in the coarse-grained silicon carbide particles due to thermal shock or mechanical shock, the cracks can be eliminated by opening pores, Closed pores inhibit the progression of cracks, thus improving thermal shock resistance.

In particular, the coarse-grained silicon carbide particles included in the upper main surface 22c' may include at least one of a plurality of, for example, two or more and five or less open pores and closed pores. If at least one of a plurality of open pores and closed pores is included, even if fine cracks are generated in the coarse-grained silicon carbide particles due to thermal shock or mechanical shock, the adjacent open pores and closed pores can Holes, etc. inhibit the progress of cracks, and their influence will be difficult to be shared with adjacent silicon carbide particles.

The equivalent circle diameters of the open pores and the closed pores are independent from each other, for example, from 1 μm to 5 μm. The circle-equivalent diameters of open pores and closed pores are the summed average of the major and minor diameters of the target pores, and can be obtained using the observation plane described later. The long diameter refers to the length of the longest part of the pores of the object whose equivalent circle diameter is to be measured, and the short diameter refers to the length of the longest part perpendicular to the direction of the long diameter.

In order to specifically identify coarse-grained silicon carbide particles, if necessary, use a tin grinder to grind to the arithmetic mean specified in JIS B 0601: 2013 (ISO 4287: 1997) with diamond abrasive grains with a particle size of 1-3 μm The roughness Ra is 0.01 μm or less. Next, the base portion 22c was immersed in a heating solution having a mass ratio of sodium hydroxide and potassium nitrate of 1:1 for 20 seconds to etch the polished surface.

Then, the etched surface was observed with an optical microscope at a magnification of 500 times, and the surface where silicon carbide particles of various sizes could be observed on average was used as the observation surface. The surface where silicon carbide particles of various sizes can be observed on average refers to the area where there are particles with an area of one particle exceeding 15000 μm ² that are not observed in other areas, or refers to the observation of a wide area of the etched surface, select coarse grained Where silicon carbide particles, granular silicon carbide particles, etc. exist uniformly, instead of deliberately selecting a particle-free area with an area of 170 μm ² or more.

In addition, the area ratio (area %) of the coarse-grained silicon carbide particles on the observation surface is a particle analysis method using image analysis software "A Xiangjun" (registered trademark in Japan, product of Asahi Kasei Engineering Corporation) using the captured image of the observation surface. to proceed. In terms of setting, the threshold value of the index indicating the intensity of the image is set to 150, and the total area of the coarse-grained silicon carbide particles with an extraction area of 170 μm ² or more is set to the area of the observation surface, for example, 0.054 mm ² (the length in the horizontal direction is 0.27mm, the longitudinal length is 0.2mm), and the value expressed as a percentage is the area ratio of coarse-grained silicon carbide particles.

To confirm whether the particles observed on the observation surface are silicon carbide particles, the distribution of Si and C, and the distribution of Si and C can be confirmed using a wavelength dispersive X-ray microanalysis device (JXA-8600M manufactured by JEOL Ltd.) When overlapping, it was confirmed that the distributions of Si and C overlapped.

Next, an embodiment of the manufacturing method of the clamping jig disclosed in the present invention will be described. A manufacturing method of a clamping jig according to an embodiment includes the following steps (a)-(d).

In step (a), the particles mainly composed of silicon carbide are filled into a forming mold and shaped to obtain a formed body.

Step (b), cutting the shaped body to obtain the precursor.

Step (c), firing the precursor to obtain a sintered body.

In step (d), the sintered body is placed on a pillow for firing or on a powder for a base in a state in which the upper main surface of the base of the sintered body is located on the upper side and the lower main surface of the base is located on the lower side. above, and in an atmospheric environment, heat treatment is carried out at a temperature above 300°C and below 750°C, wherein the firing pillow system uses at least one of carbon and carbide as the main component, and the base powder system uses carbon and carbonized At least one of the objects is used as the main component.

Regarding the step (a), first, particles containing silicon carbide as a main component are prepared, for example, in the following steps. For silicon carbide powder, prepare coarse-grained powder and fine-grained powder, and use a ball mill or bead mill to pulverize and mix ion-exchanged water and a dispersant as needed for 40-60 hours to prepare a slurry. The mass ratio of the fine-grained powder to the coarse-grained powder is, for example, 85% by mass or more and 94% by mass or less for the fine-grained powder, and 6% by mass or less and 15% by mass or less for the coarse-grained powder. The individual particle diameter ranges of the pulverized and mixed fine-grained powder and the coarse-grained powder are 0.4 μm to 4 μm and 11 μm to 34 μm, respectively.

Next, a sintering aid and a binder composed of boron carbide powder and amorphous carbon powder or phenolic resin are added to the obtained slurry, and then spray-dried to obtain a slurry whose main component is silicon carbide. particles. As for the binder, for example, acrylic emulsion, polyvinyl alcohol, polyethylene glycol, polyethylene oxide and the like can be mentioned.

Next, the obtained pellets are filled in a molding die, and pressed at a pressure of, for example, 49 MPa to 147 MPa to obtain a molded body. The obtained shaped body is subjected to step (b). Specifically, cutting processing was performed on the obtained formed body to obtain a precursor of a jig for clamping according to an embodiment. Step (c) is performed on the resulting precursor. Specifically, the obtained precursor is kept in a nitrogen atmosphere at a temperature of 450°C to 650°C for two hours to ten hours to degrease, and obtain degreasing liposome. Next, the degreased body is kept at a temperature of not less than 1800° C. and not more than 2200° C. for three hours or more but not more than six hours in a decompressed atmosphere of an inert gas such as argon to obtain a sintered body.

Next, step (d) is performed on the obtained sintered body. Specifically, the obtained sintered body is heat-treated at a temperature of 300° C. to 750° C. in an air atmosphere. By performing heat treatment (annealing treatment) at a temperature of 300° C. to 750° C. in an air environment, the carbon existing on the upper main surface 22c′ of the base portion 22c is reduced compared to the carbon existing on the upper main surface 22c′ of the base portion 22c. Part of the carbon is more likely to fly. As a result, the carbon present on the upper main surface 22c' of the base portion 22c becomes smaller than the carbon present in the portion other than the upper main surface 22c' of the base portion 22c. When performing this heat treatment, the upper principal surface 22c' of the base is positioned on the upper side and the lower principal surface of the base is positioned on the lower side, and the base is placed on the pillow for firing or on the powder for the bottom. The powder system for the pillow and the base has at least one of carbon and carbide as a main component. Carbon based such as graphite. Carbides such as silicon carbide, boron carbide, titanium carbide, etc.

The main component of the pillow for firing or the powder for the base refers to the component accounting for 90% by mass or more out of the total 100% by mass of these components, and silicon, aluminum, sodium, etc. may also be included. In particular, the main component is preferably 95% by mass or more. When the base part 22c is placed on the padding powder, the padding powder may be arranged adjacent to each other so as to have an area equal to or greater than the area of the lower main surface of the base part 22c. The heat treatment temperature is preferably not less than 400°C and not more than 500°C.

In the clamping jig produced by the above production method, the upper main surface of the base that is easily exposed to fluorine-containing acids such as hydrofluoric acid and hypofluorous acid is less prone to whitening. Therefore, the jig for clamping disclosed by the present invention can reduce the deterioration of the appearance, and can be continuously used as a component such as a cleaning device for a long time.

1: Shell

2: chamber

3: The first window

4: The first gate

5: Transfer arm

6: Second window

7:Second gate

8: Swivel clamp

9: Gas supply part

10: Disposal Cup

10a: Emission Department

11: Lower side panel

12:Rotating board

13: Cylindrical body

14: belt body

15: Motor

16: Upper side panel

17: Second axis body

18: Second horizontal board

19: motor

20: The second lifting mechanism

21: Second flow path

22: Fixture for clamping

23: The first channel

24: The first axis body

25: Horizontal board

26: The first lifting mechanism

30: Cleaning device

W: Substrate

Claims (9)

A fixture for clamping, comprising: a pillar part; a gripping part, located at one end of the pillar part, for holding the outer periphery of a substrate; and a base part, located at the other end of the pillar part, for supporting the aforementioned The pillar part; wherein at least the base part contains ceramics mainly composed of silicon carbide; in the base part, the carbon existing on the upper main surface is less than the carbon existing on the part other than the upper main surface. The jig for clamping according to Claim 1, wherein, on the upper main surface of the base, the ratio of the count value of carbon to the count value of silicon when element mapping analysis is performed with an electronic microprobe analyzer is 0.004 the following. The jig for clamping according to claim 1 or 2, wherein the pillar part is made of ceramics mainly composed of silicon carbide, and at least the pillar part and the base part are integrally formed. The jig for clamping according to claim 1 or 2, wherein the difference Rδc of the upper main surface of the base is 0.17 μm to 0.38 μm, and the difference Rδc represents the upper main surface of the base. The difference between the degree of cross-section at a load length ratio of 25% in the surface roughness curve and the degree of cross-section at a load length ratio of 75% in the aforementioned roughness curve. The clamping jig according to claim 1 or 2, wherein the root mean square slope RΔq of the roughness curve of the upper main surface of the base is 0.18 to 0.5. The jig for clamping according to claim 1 or 2, wherein at least the upper main surface of the base part contains coarse-grained silicon carbide particles with an area of 170 μm ^{or more} in an area of 6 to 15 area %. The jig for clamping according to Claim 6, wherein the aforementioned coarse silicon carbide particles include at least one of open pores and closed pores. A method for manufacturing a jig for clamping, comprising: filling a forming mold with particles mainly composed of silicon carbide and forming it to obtain a formed body; cutting the formed body to obtain a precursor; firing the A step of obtaining a sintered body from the precursor; and placing the sintered body on a firing pillow in a state where the upper main surface of the base of the sintered body is located on the upper side and the lower main surface of the aforementioned base is located on the lower side. Or a step of heat-treating the powder for the bottom at a temperature of 300°C to 750°C in the air environment, wherein the firing pillow is made of at least one of carbon and carbide as the main component, the The base powder system contains at least one of carbon and carbide as a main component. A cleaning device comprising the clamping jig described in any one of claims 1 to 7.

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