Forming method

Abstract

To improve the wear resistance of components used in substrate processing apparatus disclosed in the present application specification.SOLUTION: The molding method related to the technology disclosed in the present application specification is a molding method of a molding used in substrate processing apparatus. The molding method comprises the process of irradiating the molding, which is made of a copolymer of tetrafluoroethylene and ethylene, with an electron beam.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to molded products used in substrate processing equipment. The substrates to be processed include, for example, semiconductor wafers, glass substrates for liquid crystal displays, substrates for flat panel displays (FPDs) such as organic electroluminescence (EL) displays, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, glass substrates for photomasks, ceramic substrates, substrates for field emission displays (FEDs), and substrates for solar cells. [Background technology]

[0002] In a substrate processing apparatus, there are arranged a large number of pipes for introducing a processing liquid for processing the substrate to the substrate, or valves for controlling the flow of the processing liquid in the pipes (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-222189 Summary of the Invention [Problem to be solved by the invention]

[0004] To ensure uniform substrate processing, it is important to maintain the cleanliness of the processing solution. However, particles may be generated due to wear on the components of the piping, etc., and these particles may become mixed into the processing solution. When such particles are mixed in, the cleanliness of the processing solution decreases, making it difficult to perform uniform substrate processing.

[0005] The technology disclosed in the present specification has been made in consideration of the problems described above, and is a technology for improving the wear resistance of members used in substrate processing apparatuses. [Means for solving the problem]

[0006] A molding method according to a first aspect of the technology disclosed in the present specification is a molding method for molding a molded article used in a substrate processing apparatus, and includes a step of irradiating the molded article made of a copolymer of tetrafluoroethylene and ethylene with an electron beam. and a step of applying an acidic chemical solution containing hydrogen peroxide to the molded article after the electron beam irradiation. .

[0007] The molding method, which is the second aspect of the technology disclosed in the present specification, is related to the molding method, which is the first aspect, and the step of irradiating the molded article with the electron beam is a step of irradiating the electron beam only to a portion of the molded article.

[0008] The molding method, which is the third aspect of the technology disclosed in the present specification, is related to the molding method, which is the second aspect, and the step of irradiating the molded product with the electron beam is a step of irradiating the electron beam only to the edge of the molded product.

[0010] The first technology disclosed in the present specification 4 The molding method according to the present invention is 1 In the molding method according to the aspect of the present invention, the step of applying the chemical solution to the molded product is a step of applying the chemical solution, which is a mixed solution of hydrochloric acid and hydrogen peroxide, or a mixed solution of sulfuric acid and hydrogen peroxide, to the molded product. [Effects of the Invention]

[0012] At least one of the techniques disclosed in the present specification 1 of According to this aspect, a molded product having high abrasion resistance can be obtained, and thus particles generated due to abrasion of the molded product can be significantly reduced. Therefore, in a substrate processing apparatus in which the molded product is used as a component, it is possible to reduce the inclusion of particles in a processing solution for processing substrates.

[0013] Furthermore, objects, features, aspects, and advantages associated with the technology disclosed herein will become more apparent from the detailed description and accompanying drawings set forth below. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a plan view schematically showing an example of the configuration of a substrate processing apparatus according to an embodiment; [Figure 2] 2 is a diagram illustrating an example of the configuration of a control unit illustrated in FIG. 1. FIG. [Figure 3] FIG. 2 illustrates an example of the configuration of a processing unit. [Figure 4] 10 is a flowchart showing an operation in a processing unit among the operations of the substrate processing apparatus. [Figure 5] 4 is a diagram showing an example of the configuration of a processing cup in the processing unit shown in FIG. 3. FIG. [Figure 6] 4 is a diagram showing an example of the configuration of a diaphragm valve in the processing unit shown in FIG. 3. FIG. [Figure 7] FIG. 10 is a diagram showing an example of a molded product immersed in a predetermined chemical solution. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments will be described with reference to the accompanying drawings. In the following embodiments, detailed features will be shown for the purpose of explaining the technology, but these are merely examples and are not necessarily essential features for enabling the embodiments to be implemented.

[0016] The drawings are schematic, and for the sake of convenience, components may be omitted or simplified as appropriate. The relative sizes and positions of components shown in different drawings are not necessarily accurately depicted and may be changed as appropriate. Hatching may also be used in drawings such as plan views that are not cross-sectional views to facilitate understanding of the embodiments.

[0017] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions of them may be omitted to avoid duplication.

[0018] Furthermore, in the description given in this specification, when a certain component is described as "comprising," "including," or "having," unless otherwise specified, this is not an exclusive expression that excludes the presence of other components.

[0019] Furthermore, although ordinal numbers such as "first" or "second" may be used in the descriptions in this specification, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and the contents of the embodiments are not limited to the order that may result from these ordinal numbers.

[0020] Furthermore, in the description given in this specification, expressions such as "positive direction of the ... axis" or "negative direction of the ... axis" refer to the direction along the arrow of the ... axis shown in the figure as the positive direction, and the direction opposite to the arrow of the ... axis shown in the figure as the negative direction.

[0021] Furthermore, in the description provided in this specification, terms that indicate specific positions or directions, such as "top," "bottom," "left," "right," "side," "bottom," "front," or "back," may be used, but these terms are used for convenience to facilitate understanding of the contents of the embodiments and have no relation to the positions or directions when the embodiments are actually implemented.

[0022] Furthermore, in the description of the present specification, when "the upper surface of ..." or "the lower surface of ..." is used, it is intended to include not only the upper surface or lower surface of the target component itself, but also a state in which another component is formed on the upper surface or lower surface of the target component. For example, when it is described as "B provided on the upper surface of A," it does not preclude another component "C" from being interposed between A and B.

[0023] Furthermore, in the explanations given in this specification, expressions indicating a shape, such as "rectangular shape" or "cylindrical shape," unless otherwise specified, include cases in which the shape is strictly that shape, as well as cases in which irregularities or chamfers are formed within a tolerance or within a range in which the same level of functionality is obtained.

[0024] <Embodiment> The molded product and molding method according to this embodiment will be described below.

[0025] <Configuration of the substrate processing apparatus> First, the configuration of a substrate processing apparatus in which molded products are used will be described.

[0026] 1 is a plan view schematically illustrating an example of the configuration of a substrate processing apparatus 1 according to this embodiment. The substrate processing apparatus 1 includes a load port 601, an indexer robot 602, a center robot 603, a control unit 90, and at least one processing unit 600 (four processing units in FIG. 1).

[0027] The processing unit 600 is a single-wafer processing apparatus that can be used for substrate processing, and specifically, an apparatus that performs processing to remove organic matter adhering to the substrate W. The organic matter adhering to the substrate W is, for example, a used resist film. The resist film has been used, for example, as an implantation mask for an ion implantation process.

[0028] The processing unit 600 may include a chamber 180. In this case, the atmosphere in the chamber 180 may be controlled by the control unit 90, allowing the processing unit 600 to perform substrate processing in a desired atmosphere.

[0029] The control unit 90 can control the operation of each component in the substrate processing apparatus 1. The carrier C is a container that stores substrates W. The load port 601 is a container holding mechanism that holds multiple carriers C. The indexer robot 602 can transport substrates W between the load port 601 and the substrate platform 604. The center robot 603 can transport substrates W between the substrate platform 604 and the processing unit 600.

[0030] With the above configuration, the indexer robot 602 , the substrate platform 604 and the center robot 603 function as a transport mechanism for transporting substrates W between each processing unit 600 and the load port 601 .

[0031] The unprocessed substrate W is taken out of the carrier C by the indexer robot 602. Then, the unprocessed substrate W is transferred to the center robot 603 via the substrate placement unit 604.

[0032] The center robot 603 carries the unprocessed substrate W into the processing unit 600. Then, the processing unit 600 processes the substrate W.

[0033] The substrate W that has been processed in the processing unit 600 is removed from the processing unit 600 by the center robot 603. Then, the processed substrate W passes through other processing units 600 as necessary, and is then transferred to the indexer robot 602 via the substrate placement part 604. The indexer robot 602 loads the processed substrate W into the carrier C. In this manner, the processing of the substrate W is completed.

[0034] Fig. 2 is a diagram showing an example of the configuration of the control unit 90 shown in Fig. 1. The control unit 90 may be configured by a general computer having electric circuits. Specifically, the control unit 90 includes a central processing unit (CPU) 91, a read only memory (ROM) 92, a random access memory (RAM) 93, a recording device 94, an input unit 96, a display unit 97, and a communication unit 98, as well as a bus line 95 interconnecting these units.

[0035] The ROM 92 stores a basic program. The RAM 93 is used as a work area when the CPU 91 performs predetermined processing. The recording device 94 is composed of a non-volatile recording device such as a flash memory or a hard disk drive. The input unit 96 is composed of various switches or a touch panel, and receives input setting instructions such as processing recipes from the user. The display unit 97 is composed of, for example, a liquid crystal display device and lamps, and displays various information under the control of the CPU 91. The communication unit 98 has a data communication function via a local area network (LAN), etc.

[0036] The recording device 94 has preset therein a plurality of modes for controlling each component in the substrate processing apparatus 1 of FIG. 1. When the CPU 91 executes the processing program 94P, one of the above-described modes is selected, and each component is controlled in that mode. The processing program 94P may be recorded on an external recording medium. Using this recording medium, the processing program 94P can be installed in the control unit 90. Furthermore, some or all of the functions executed by the control unit 90 do not necessarily have to be realized by software, but may be realized by hardware such as a dedicated logic circuit.

[0037] <About the processing unit> Fig. 3 is a diagram showing an example of the configuration of a processing unit 600. As shown in the example in Fig. 3, the processing unit 600 includes a spin chuck 10 that holds one substrate W in a substantially horizontal position and rotates the substrate W about a vertical rotation axis Z1 that passes through the center of the substrate W, a processing liquid nozzle 20 that discharges a processing liquid onto the substrate W, a nozzle arm 22 to which the processing liquid nozzle 20 is attached at its end, and a cylindrical processing cup 12 that surrounds the spin chuck 10 about the rotation axis Z1 of the substrate W.

[0038] When multiple types of processing liquid are expected, multiple processing liquid nozzles 20 may be provided corresponding to the respective processing liquids. The processing liquid nozzles 20 eject the processing liquid onto the upper surface of the substrate W. A diaphragm valve 124 for controlling the supply of the processing liquid is provided in a pipe for supplying the processing liquid to the processing liquid nozzles 20. The diaphragm valve 124 is controlled by, for example, the control unit 90.

[0039] The spin chuck 10 includes a disk-shaped spin base 10A that vacuum-sucks the underside of the substrate W in a substantially horizontal position, a rotation shaft 10C that extends downward from the center of the spin base 10A, and a spin motor 10D that rotates the rotation shaft 10C to rotate the substrate W that is attracted to the spin base 10A. Note that instead of the spin chuck 10, a clamping chuck that includes multiple chuck pins that protrude upward from the outer periphery of the upper surface of the spin base and clamps the peripheral edge of the substrate W with the chuck pins may be used.

[0040] The nozzle arm 22 includes an arm portion 22A, a shaft body 22B, and a drive unit 22C. The drive unit 22C adjusts the extension and contraction of the shaft body 22B and the angle of the shaft body 22B around its axis. One end of the arm portion 22A is fixed to the shaft body 22B, and the other end of the arm portion 22A is disposed away from the axis of the shaft body 22B. The processing liquid nozzle 20 is attached to the other end of the arm portion 22A. This allows the processing liquid nozzle 20 to swing in the radial direction of the substrate W. Note that the movement direction of the processing liquid nozzle 20 due to the swinging movement only needs to have a radial component of the substrate W, and does not need to be strictly parallel to the radial direction of the substrate W.

[0041] The processing cup 12 comprises a cylindrical guard 12A that surrounds the spin chuck 10 in a planar view, a shaft 12B attached to the guard 12A, a drive unit 12C that raises and lowers the guard 12A, and a cylindrical guard 12D that surrounds the guard 12A in a planar view.

[0042] The control unit 90 controls the rotation speed of the spin motor 10D of the spin chuck 10, and causes the processing liquid nozzle 20 to discharge the processing liquid onto the upper surface of the substrate W. The control unit 90 also controls the driving of the driving unit 22C of the nozzle arm 22, thereby moving and swinging the processing liquid nozzle 20 up and down above the upper surface of the substrate W. The control unit 90 also controls the driving of the driving unit 12C of the processing cup 12, thereby moving the guard 12A up and down.

[0043] <Operation of the substrate processing apparatus> Next, an example of the operation of the substrate processing apparatus 1 will be described with reference to Fig. 4. Fig. 4 is a flowchart showing the operation of the processing unit 600 in the operation of the substrate processing apparatus 1.

[0044] The indexer robot 602 transports the substrate W from the carrier C in the load port 601 to the substrate mounting part 604. The center robot 603 transports the substrate W from the substrate mounting part 604 to one of the processing units 600. The processing unit 600 processes the substrate W. The center robot 603 transports the substrate W from the processing unit 600 to the substrate mounting part 604. The indexer robot 602 transports the substrate W from the substrate mounting part 604 to the carrier C in the load port 601.

[0045] In the substrate processing in the processing unit 600, first, a chemical solution is supplied to the upper surface of the substrate W to perform a predetermined chemical processing (step ST01 in FIG. 4). Then, pure water (DIW) or the like is supplied to the upper surface of the substrate W to perform a rinse processing (step ST02 in FIG. 4). Furthermore, the substrate W is rotated at high speed to shake off the pure water, thereby drying the substrate W (step ST03 in FIG. 4).

[0046] In the chemical liquid treatment among the above substrate treatments, a predetermined treatment liquid is discharged from a treatment liquid nozzle 20 onto the upper surface of the substrate W held and rotating on the spin chuck 10. The type, discharge amount, concentration, temperature, discharge timing, etc. of the treatment liquid discharged from the treatment liquid nozzle 20 are controlled by the control unit 90 based on a treatment recipe recorded in a recording device 94 or the like.

[0047] <About the composition of molded products> Next, the configuration of the molded article used as at least a part of the constituent members of the substrate processing apparatus 1 will be described.

[0048] The molded article used in the substrate processing apparatus 1 according to this embodiment is a fluororesin made of a copolymer of tetrafluoroethylene C2F4 and ethylene C2H4 (tetrafluoroethylene-ethylene copolymer resin, i.e., ETFE). ETFE is a thermoplastic resin similar to perfluoroalkoxyalkane (PFA). ETFE also has chemical resistance, insulating properties, and abrasion resistance. ETFE can be molded not only by cutting but also by molding, which helps keep manufacturing costs down.

[0049] The above molded products can be applied to any configuration in the substrate processing apparatus 1, but because they are highly wear-resistant components, they are particularly desirable for use in components that are subject to repeated deformation or separation, such as bellows parts, diaphragms and valve seats of valve components, and chuck pins used to hold substrates.

[0050] FIG. 5 is a diagram showing an example of the configuration of the processing cup 12 in the processing unit 600 shown in FIG.

[0051] The shaft 12B of the processing cup 12 comprises a connecting portion 85 connected to the lateral end of the guard 12A, a lifting head 82 that can move up and down together with the guard 12A via the connecting portion 85, and a bellows 84 that covers the lifting head 82 and is expandable and contractible in the Z-axis direction.

[0052] The drive unit 12C of the processing cup 12 includes a drive source 81 including a horizontally extending rotation shaft 81A, and a transmission mechanism 83 that transmits the rotation of the rotation shaft 81A to the lifting head 82, thereby moving the lifting head 82 up and down. The drive source 81 is, for example, a motor that rotates the rotation shaft 81A.

[0053] The transmission mechanism 83 includes a plurality of rack teeth 83A formed on the lifting head 82, and a plurality of pinion teeth 83B to which the rotation of the rotary shaft 81A is transmitted and which mesh with the rack teeth 83A.

[0054] When the drive motor of the drive source 81 rotates the rotary shaft 81A, the pinion teeth 83B at the tip of the rotary shaft 81A rotates. The rotation of the pinion teeth 83B is transmitted to the lifting head 82 via the rack teeth 83A and converted into linear motion of the lifting head 82 in the Z-axis direction. This causes the lifting head 82 to move up and down. The guard 12A is then raised and lowered in accordance with the up and down movement of the lifting head 82.

[0055] Here, the above-mentioned molded product, that is, one formed from a fluororesin made of ETFE, can be used for the bellows 84. By using the above-mentioned molded product, which has high wear resistance, for the bellows 84, it is possible to significantly reduce particles generated due to wear of the bellows 84. Furthermore, because the wear resistance of the bellows 84 is improved, deterioration of the bellows 84 over time is suppressed, and the replacement cycle of the bellows 84 can be extended.

[0056] Furthermore, the same lifting head and bellows as those of the shaft 12B can be applied to the shaft 22B of the nozzle arm 22 shown in Fig. 3. In this case, the bellows can also be made of the above-mentioned molded product, i.e., a fluororesin made of ETFE.

[0057] However, because nozzle arm 22 is provided with arm portion 22A that can swing around shaft body 22B, the bellows may undergo torsional deformation due to rotation in the XY plane in addition to expansion and contraction deformation in the Z axis direction. In such a case, by using a fluororesin made of ETFE that has been irradiated with an electron beam only at the end of the bellows where stress tends to concentrate (i.e., region 222 shown in Figure 3), it is possible to efficiently improve the wear resistance of the molded product while suppressing the amount of electron beam irradiation.

[0058] FIG. 6 is a diagram showing an example of the configuration of the diaphragm valve 124 in the processing unit 600 shown in FIG.

[0059] The diaphragm valve 124 comprises a body 24 in which a flow path 23 extending from an inlet 121 to an outlet 122 is formed, a diaphragm 25 as a valve body for opening and closing the flow path 23, a piston rod 26 for driving the diaphragm 25, and a cylindrical body 27 for accommodating the piston rod 26 therein.

[0060] The body 24 is made of fluororesin (PTFE or PFA), and has an inlet channel 28 formed therein that communicates with the inlet 121. The processing liquid supplied to the processing liquid nozzle 20 flows into the inlet channel 28 through the inlet 121. The inlet channel 28 is bent at a substantially right angle midway toward the diaphragm 25.

[0061] Furthermore, an outlet path 29 communicating with the outlet port 122 is formed inside the body 24. The outlet path 29 and the inlet path 28 form the flow path 23. The outlet path 29 has an inlet end facing the diaphragm 25, and is bent at a right angle toward the outlet port 122 a predetermined distance downstream from the inlet end. The processing liquid is supplied from the outlet path 29 through the outlet port 122 to the processing liquid nozzle 20.

[0062] A valve seat 30 for seating the diaphragm 25 is formed at the inlet end of the outflow passage 29. Therefore, the outflow passage 29 communicates with the inflow passage 28 via the valve seat 30.

[0063] Valve seat 30 has a tubular (specifically, cylindrical) shape, and is provided at its tip (i.e., the end facing diaphragm 25) with an annular seal member 120. Seal member 120 is, for example, an O-ring with a circular cross section, and is provided so that its annular tip edge protrudes toward diaphragm 25 beyond the tip face of valve seat 30 (the face facing diaphragm 25), forming a seating surface on which diaphragm 25 sits.

[0064] A space 31 for allowing the diaphragm 25 to move is formed at the end of the cylindrical body 27 facing the body 24, and furthermore, the piston rod 26 is inserted into a guide hole 32 that communicates with the space 31.

[0065] A piston 33 is attached to a portion of the piston rod 26 that is disposed in the internal space of the cylindrical body 27. A port 35 that faces the outer surface of the body 24 is formed in the space 34, closer to the body 24 than the piston 33. An air supply pipe 14 is connected to the port 35, and air (compressed air for operation) is supplied from the air supply pipe 14 into the space 34.

[0066] A cover 36 is attached to the cylindrical body 27 on the side opposite the body 24, and the piston rod 26 is slidably inserted into a cylindrical boss 37 formed on the inner surface of this cover 36. A compression coil spring 38 is arranged around the boss 37 so as to surround it. The compression coil spring 38 biases the diaphragm 25 toward the body 24. A space 39 that houses the compression coil spring 38 communicates with the atmosphere via a port 40.

[0067] The diaphragm 25 has a seal surface 25A that faces the tip surface of the valve seat 30. A central portion 41 of the diaphragm 25 is formed to be thick. On the surface of the central portion 41 opposite the seal surface 25A, a fitting recess 42 that fits onto a fixing protrusion 26A provided on the tip of the piston rod 26 is formed in the central portion 41. The central portion 41 is fitted onto the fixing protrusion 26A via the fitting recess 42, and the central portion 41 is fixed to the piston rod 26. A peripheral portion 43 of the diaphragm 25 is fixed to the body 24. Therefore, the diaphragm 25 deforms as the piston rod 26 moves.

[0068] When air is supplied from the air supply pipe 14 to the space 34 via the port 35, the pressure in the space 34 increases. Then, the piston rod 26 moves toward the cover 36 (in the positive direction of the Z axis in FIG. 6 ) against the elastic force of the compression coil spring 38. Along with the piston rod 26, the center portion 41 of the diaphragm 25 moves away from the valve seat 30 toward the cover 36, thereby deforming the diaphragm 25. In this way, a gap S is formed between the diaphragm 25 and the valve seat 30 (and the seal member 120), and the flow path 23 is opened. As a result, the treatment liquid in the inflow path 28 flows into the outflow path 29 via the gap S.

[0069] On the other hand, when the air in the space 34 is discharged into the atmosphere through the port 35, the pressure in the space 34 becomes atmospheric pressure. Then, the elastic force of the compression coil spring 38 moves the piston rod 26 toward the body 24 (in the negative direction of the Z axis in FIG. 6 ), and the diaphragm 25 returns to its original shape along with the piston rod 26. The seal member 120 is interposed between the diaphragm 25 and the valve seat 30 in a tight contact state, and the flow path 23 is closed. Therefore, the treatment liquid in the inflow path 28 does not flow into the outflow path 29.

[0070] Here, the diaphragm 25 can be the above-mentioned molded product, i.e., one formed from a fluororesin such as ETFE. By using a diaphragm 25 with high wear resistance, particles generated by wear of the diaphragm 25 can be significantly reduced. Therefore, particles can be prevented from being mixed into the processing liquid. Furthermore, since particles are prevented from being mixed into the processing liquid, the cleanliness of the processing liquid is improved, thereby shortening the process time required to remove impurities from the processing liquid prior to substrate processing. This allows for early start-up of the substrate processing apparatus. Furthermore, since the wear resistance of the diaphragm 25 is improved, deterioration of the diaphragm 25 over time is suppressed, thereby extending the replacement cycle of the diaphragm 25.

[0071] <About the manufacturing method of molded products> Next, a method for manufacturing a molded product according to this embodiment will be described.

[0072] First, a layer of uncrosslinked fluororesin (ETFE) is formed on a substrate. To form a fluororesin layer on a substrate, a fluororesin dispersion is usually applied to the substrate by dipping, spin coating, spray coating, or the like, followed by drying.

[0073] Alternatively, a fluororesin layer can be formed on a substrate by applying a powder coating of fluororesin (ETFE) to the substrate. Examples of powder coating methods include electrostatic coating and fluidized bed coating. The use of a fluororesin dispersion coating method is preferred because it allows for the formation of a uniform, thin coating film.

[0074] Next, the fluororesin layer, whose temperature has been adjusted to a temperature suitable for irradiation, is irradiated with radiation (electron beam) at a dose of, for example, 50 kGy or more and 250 kGy or less in an atmosphere with an oxygen concentration of 1000 ppm or less, thereby crosslinking the uncrosslinked fluororesin.

[0075] Examples of radiation that can be used include particle rays such as α-rays (particle rays of helium-4 nuclei emitted from radioactive nuclei undergoing α-decay), β-rays (negative electrons and positrons emitted from atomic nuclei), and electron beams (electron beams with almost constant kinetic energy generated by, for example, accelerating thermal electrons in a vacuum), and ionizing radiation such as γ-rays (short-wavelength electromagnetic waves emitted or absorbed by transitions between energy levels of atomic nuclei or elementary particles, or by pair annihilation, pair creation, etc. of elementary particles). However, from the viewpoint of crosslinking efficiency or operability, electron beams and γ-rays are preferred, and electron beams are used in this embodiment.

[0076] The radiation exposure dose is, for example, 50 kGy or more and 250 kGy or less, but from the viewpoint of abrasion resistance, it is preferably, for example, 55 kGy or more and 230 kGy or less, and more preferably, for example, 60 kGy or more and 200 kGy or less.

[0077] It is important to maintain the oxygen concentration of the atmosphere in the radiation irradiated area at 1000 ppm or less in order to promote the crosslinking reaction. The oxygen concentration in the atmosphere in the radiation irradiated area is preferably 800 ppm or less, more preferably 500 ppm or less, and particularly preferably 300 ppm or less. The lower limit of the oxygen concentration is usually 0.1 ppm, and in many cases is about 1 ppm.

[0078] The electron beam irradiation breaks the C—F bonds and C—H bonds in ETFE, generating carbon radicals (alkyl carbon radicals, polyenyl carbon radicals). Then, C—C bonds are formed between adjacent carbon radicals, forming crosslinks. The crosslinked structure in ETFE improves the abrasion resistance of ETFE. For example, the limiting PV value of polytetrafluoroethylene (PTFE) is about 10 [MPa·m / min], while the limiting PV value of uncrosslinked ETFE is about 100 [MPa·m / min]. Furthermore, the limiting PV value of ETFE after electron beam irradiation is about 1200 [MPa·m / min].

[0079] Here, the electron beam irradiation may be performed on only a part of the molded product. For example, the electron beam may be irradiated only on region 222 of the bellows member used in shaft body 22B shown in Fig. 3. Note that the location selectively irradiated with the electron beam is not limited to the end of the molded product such as region 222, and may be other locations.

[0080] <About discoloration of molded products> When ETFE is irradiated with electron beams as described above, it becomes cross-linked, improving its abrasion resistance. On the other hand, when ETFE is irradiated with electron beams as described above, its color changes from white to brown.

[0081] The brown color change is thought to be caused by residual radicals, and the fading occurs due to the removal of residual radicals inside by penetration or other means.

[0082] If the ETFE whose color has changed in this way is immersed in a specific chemical solution, the color of the ETFE will fade and it will return to the color it had before being irradiated with the electron beam (white).

[0083] Fig. 7 is a diagram showing an example of a molded product immersed in a predetermined chemical solution. As shown in the example in Fig. 7, a molded product 56 made of ETFE and irradiated with the electron beam is immersed in a predetermined chemical solution 54 stored in a container 52.

[0084] The chemical solution 54 is an acidic chemical solution containing hydrogen peroxide, such as a mixed solution of hydrochloric acid and hydrogen peroxide, or a mixed solution of sulfuric acid and hydrogen peroxide. In the case of a mixed solution of hydrochloric acid and hydrogen peroxide, for example, the ratio of 36 wt% hydrochloric acid, 30 wt% hydrogen peroxide, and pure water is 1:1:4, and the temperature is 70°C. In the case of a mixed solution of sulfuric acid and hydrogen peroxide, for example, the ratio of 96 wt% sulfuric acid and 30 wt% hydrogen peroxide is 2:1, and the temperature is 80°C. The immersion time is, for example, about several weeks (e.g., 4 weeks).

[0085] The method of applying the chemical solution 54 to the molded article 56 is not limited to the above-described immersion method. For example, the chemical solution 54 may be applied to the molded article 56 in droplet form, or may be sprayed onto the molded article 56 in atomized form. Furthermore, although the chemical solution 54 is applied to the molded article 56 in the above embodiment, pure water (DIW) may be used instead of the chemical solution 54. Even when pure water (DIW) is applied to the molded article 56, it is possible to fade the color caused by irradiation with the electron beam. In particular, heated pure water (DIW) can fade the color more effectively than unheated pure water (DIW).

[0086] If the color of a molded product made of ETFE changes to brown or the like, it may be mistakenly believed that the molded product has been contaminated during substrate processing. Therefore, fading the color of the molded product made of ETFE to return it to the color it had before being irradiated with an electron beam as described above has the effect of suppressing such misidentification. As a result, it is possible to reduce the number of times that substrate processing is interrupted due to such misidentification, thereby improving the throughput of substrate processing.

[0087] <Effects of the above-described embodiments> Next, examples of effects obtained by the above-described embodiments will be described. Note that in the following description, the effects will be described based on the specific configurations exemplified in the above-described embodiments, but these may be replaced with other specific configurations exemplified in the present specification as long as the same effects are obtained. In other words, for convenience, only one of the corresponding specific configurations may be described as a representative below, but the representatively described specific configuration may be replaced with another corresponding specific configuration.

[0088] According to the embodiment described above, the molding method includes a step of irradiating the molded article 56 made of a copolymer of tetrafluoroethylene and ethylene with an electron beam.

[0089] This configuration provides a molded product 56 with high wear resistance, significantly reducing particle generation due to wear of the molded product 56. Therefore, in a substrate processing apparatus 1 in which the molded product 56 is used as a component, particle contamination in the processing liquid used to process substrates W can be reduced. Furthermore, the molded product 56, made of a copolymer of tetrafluoroethylene and ethylene, can be molded not only by cutting but also by molding, allowing for greater flexibility in molding. Furthermore, the molded product 56 can be obtained at lower cost than PFA, PTFE, and the like. Furthermore, the reduced contamination of particles in the processing liquid improves the cleanliness of the processing liquid, thereby shortening the process time required to remove impurities from the processing liquid prior to substrate processing. This allows for earlier start-up of the substrate processing apparatus 1. Furthermore, the improved wear resistance of the molded product 56 reduces deterioration over time of the molded product 56, thereby extending the replacement cycle of the molded product 56.

[0090] Furthermore, even if other configurations shown as examples in this specification are appropriately added to the above configuration, that is, even if other configurations in this specification that were not mentioned as the above configuration are appropriately added, the same effect can be achieved.

[0091] Furthermore, according to the embodiment described above, the step of irradiating the molded article 56 with an electron beam is a step of irradiating the electron beam only to a portion of the molded article 56. With this configuration, by selecting the region to be irradiated with the electron beam depending on the degree of deformation of the molded article 56, it is possible to efficiently improve the wear resistance of the molded article 56 while suppressing the amount of electron beam irradiation.

[0092] Furthermore, according to the embodiment described above, the step of irradiating the molded article 56 with an electron beam is a step of irradiating the electron beam only onto the end portion of the molded article 56. With this configuration, when the molded article 56 undergoes deformation including not only linear expansion and contraction but also torsion, the electron beam is selectively irradiated onto the end portion of the molded article 56 where the degree of deformation is likely to be large (i.e., where stress is likely to concentrate), thereby making it possible to efficiently improve the wear resistance of the molded article 56 while suppressing the amount of electron beam irradiation.

[0093] Furthermore, according to the embodiment described above, the molding method includes a step of applying an acidic chemical solution containing hydrogen peroxide to the molded article 56 after the electron beam irradiation. This configuration allows the color caused by the electron beam irradiation to fade. Therefore, it is possible to prevent a molded article 56 whose color has changed to brown or the like from being mistaken for contamination (metal contamination, organic contamination, etc.) during substrate processing, etc. This reduces the chance of interrupting substrate processing due to such a mistake, and improves the throughput of substrate processing.

[0094] Furthermore, according to the embodiment described above, the step of applying a chemical solution to the molded article 56 is a step of applying a chemical solution that is a mixed solution of hydrochloric acid and hydrogen peroxide or a mixed solution of sulfuric acid and hydrogen peroxide to the molded article 56. With this configuration, it is possible to fade the color that has been produced by irradiation with an electron beam with high accuracy.

[0095] According to the embodiment described above, the molded article is molded article 56 used in substrate processing apparatus 1, which is made of a copolymer of tetrafluoroethylene and ethylene and is brown in color.

[0096] According to this configuration, a molded product 56 having high abrasion resistance can be obtained, which significantly reduces particles generated due to abrasion of the molded product 56. Therefore, in the substrate processing apparatus 1 in which the molded product 56 is used as a component, it is possible to prevent particles from being mixed into the processing liquid for processing the substrate.

[0097] Furthermore, even if other configurations shown as examples in this specification are appropriately added to the above configuration, that is, even if other configurations in this specification that were not mentioned as the above configuration are appropriately added, the same effect can be achieved.

[0098] <Modifications of the above-described embodiments> In the embodiments described above, the material, composition, dimensions, shape, relative positional relationship, or implementation conditions of each component may also be described, but these are merely examples in all aspects and are not limiting.

[0099] Thus, numerous variations and equivalents not shown are contemplated within the scope of the technology disclosed herein, including, for example, the modification, addition, or omission of at least one component.

[0100] Furthermore, in the embodiments described above, when a material name is mentioned without any particular specification, it is assumed that the material may contain other additives, such as an alloy, unless a contradiction arises. [Explanation of symbols]

[0101] 1. Substrate processing equipment 10 Spin chuck 10C, 81A Rotating shaft 10A Spin Base 10D Spin Motor 12 Processing Cups 12B,22B shaft body 12C, 22C drive unit 12A, 12D Guard 14 Air supply piping 20 Processing liquid nozzle 22 Nozzle arm 22A Arm section 23 Flow path 24 Body 25 diaphragm 25A sealing surface 26 Piston rod 26A Fixing protrusion 27 Cylinder 28 Inflow channel 29 Outflow channel 30 Valve seat 31,34,39 space 32 Guide hole 33 Piston 35,40 ports 36 Cover 37 Boss 38 Compression coil spring 41 Central part 42 mating recess 43 Periphery 52 Container 54 Chemical Solution 56 Molded products 81 Power Source 82 Lifting head 83 Transmission Mechanism 83A rack teeth 83B Pinion teeth 84 Bellows 85 Connecting part 90 Control Unit 91 CPU 92 ROM 93 RAM 94 Recording Devices 94P Processing Program 95 Bus Line 96 Input section 97 Display section 98 Communications Department 120 sealing material 121 Inlet 122 Outlet 124 Diaphragm Valve 180 Chamber 222 areas 600 processing units 601 Loading Port 602 Indexer Robot 603 Center Robot 604 Substrate placement section

Claims

1. A molding method for a molded product used in a substrate processing apparatus, The method includes a step of irradiating the molded article made of a copolymer of tetrafluoroethylene and ethylene with an electron beam, The method further includes a step of applying an acidic chemical solution containing hydrogen peroxide to the molded article after the electron beam irradiation. Molding method.

2. The molding method according to claim 1, The step of irradiating the molded article with the electron beam is a step of irradiating only a part of the molded article with the electron beam. Molding method.

3. The molding method according to claim 2, The step of irradiating the molded article with the electron beam is a step of irradiating only an end portion of the molded article with the electron beam. Molding method.

4. The molding method according to claim 1, The step of applying the chemical solution to the molded article is a step of applying the chemical solution, which is a mixed solution of hydrochloric acid and hydrogen peroxide or a mixed solution of sulfuric acid and hydrogen peroxide, to the molded article. Molding method.

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