Substrate processing apparatus and substrate processing method

Abstract

The purpose of the present invention is to prolong the life of a filter for removing organic substances from a waste liquid, which is a treatment liquid used for substrate treatment, in a treatment for generating a treatment liquid using the waste liquid. The substrate processing apparatus includes: a nozzle to which a first solution including peroxydisulfate ions is supplied and which supplies a processing liquid including the first solution to a substrate; a first tank for storing the first solution; a second tank to which a waste liquid, which is a processing liquid after processing the substrate, is supplied, and which stores a second solution; a first path for circulating the second solution between the first path and the second tank, and performing first electrolysis on the second solution to generate a third solution; a second path that has a filter and generates the first solution by performing second electrolysis while filtering the third solution by the filter; and a third path for supplying the first solution to the first tank.

Description

Technical Field

[0001] The present invention relates to a technology for processing substrates. Substrates subjected to this processing (hereinafter referred to as "substrate processing") include, for example, semiconductor wafers, glass substrates for liquid crystal displays, substrates for flat panel displays (FPDs) such as organic EL (electroluminescence) displays, substrates for optical disks, magnetic disks, magneto-optical disks, glass substrates for photomasks, ceramic substrates, substrates for field emission displays (FEDs), and substrates for solar cells. Background Art

[0002] As a treatment liquid used for substrate treatment, for example, there is a well-known mixture of sulfuric acid (H2SO4) and hydrogen peroxide (H2O2), commonly known as SPM (sulfuric acid-hydrogen peroxide mixture) (for example, see Patent Document 1 below). Peroxymonosulfuric acid (H2SO5) is generated by SPM and is used, for example, to remove resist formed on the substrate surface.

[0003] As active species (etchant) in substrate processing, it is well known that peroxydisulfate ions (S2O8 2- For example, Patent Document 2 discloses a technique for obtaining peroxydisulfate ions using a mixture of sulfuric acid and ozone (SOM: Sulfuric Ozone peroxide mixture).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-47857

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2022-188425 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] The processing liquid after substrate processing (hereinafter referred to as "waste liquid") contains a larger amount of organic matter than the processing liquid before substrate processing. For example, Patent Document 1 describes a process for generating processing liquid from recycled waste liquid (hereinafter also referred to as "regeneration" or "regeneration process").

[0010] Performing substrate processing in a state where the processing liquid contains organic matter may cause contamination during substrate processing, especially the problem of particle adhesion to the substrate. Therefore, it is desirable to remove the organic matter during the regeneration process.

[0011] This removal is performed by filtering, for example, through a filter. Removing organic matter only through the filter during regeneration has the problem of shortening the life of the filter.

[0012] In view of the above problems, this application discloses a technology for extending the life of a filter for removing organic matter from wastewater during a regeneration process.

[0013] Means used to solve problems

[0014] The substrate processing apparatus of the present invention is an apparatus for processing a substrate using a processing liquid. A first embodiment of the substrate processing apparatus comprises: a nozzle supplied with a first solution containing peroxydisulfate ions and supplying the processing liquid containing the first solution to the substrate; a first tank storing the first solution; a second tank supplied with waste liquid and storing a second solution, the waste liquid being the processing liquid after the substrate has been processed; a first path circulating the second solution between the first path and the second tank, performing a first electrolysis on the second solution to generate a third solution; a second path having a filter, filtering the third solution through the filter while performing a second electrolysis to generate the first solution; and a third path supplying the first solution to the first tank.

[0015] A second aspect of the substrate processing apparatus of the present invention is as described in the first aspect, wherein the first path includes a first electrolysis device for performing the first electrolysis. The second path includes a third tank storing the third solution, and a second electrolysis device for performing the second electrolysis by circulating the third solution between the second electrolysis device and the third tank.

[0016] A third aspect of the substrate processing apparatus of the present invention is the first aspect, wherein the second tank is included in both the first path and the second path, and the third solution is circulated between the second path and the second tank.

[0017] A fourth aspect of the substrate processing apparatus of the present invention is the third aspect, wherein the first path includes a first electrolysis device for performing the first electrolysis, and the second path includes a second electrolysis device for performing the second electrolysis.

[0018] A fifth aspect of the substrate processing apparatus of the present invention is as described in the third aspect, wherein the second path further comprises a first on-off valve connected in series with the filter. The first path comprises a second on-off valve disposed in parallel with the filter and the series connection of the first on-off valve; and an electrolysis device shared by the second path. The electrolysis device performs the first electrolysis when the first on-off valve is closed and the second on-off valve is open, and performs the second electrolysis when the second on-off valve is closed and the first on-off valve is open.

[0019] A sixth aspect of the substrate processing apparatus of the present invention is any one of the first to fifth aspects, wherein the second electrolysis is performed at a higher temperature than the first electrolysis.

[0020] The substrate processing method of the present invention is a method for processing a substrate using a processing liquid, comprising the following steps: supplying the above-mentioned processing liquid containing the first solution to the above-mentioned substrate, the above-mentioned first solution containing peroxydisulfate ions; supplying waste liquid to a tank storing a second solution, the above-mentioned waste liquid being the above-mentioned processing liquid after the above-mentioned processing on the above-mentioned substrate; in a first path that circulates the above-mentioned second solution between the above-mentioned tank, performing a first electrolysis on the above-mentioned second solution to generate a third solution; and in a second path having a filter, filtering the above-mentioned third solution through the above-mentioned filter while performing a second electrolysis to generate the above-mentioned first solution.

[0021] Effects of the Invention

[0022] The first embodiment of the substrate processing apparatus and substrate processing method of the present invention contributes to extending the life of a filter that removes organic matter from wastewater during regeneration. The second and fourth embodiments of the substrate processing apparatus contribute to suppressing degradation of an electrolysis device. The fifth embodiment of the substrate processing apparatus is easily and cost-effectively implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a block diagram schematically showing the configuration of the substrate processing apparatus of the present invention.

[0024] Figure 2 It is a schematic diagram illustrating the structure of the supply recovery unit.

[0025] Figure 3 It is a schematic diagram illustrating the configuration of a processing unit.

[0026] Figure 4 This is a schematic diagram schematically illustrating a processing unit and related components.

[0027] Figure 5 It is a cross-sectional view illustrating the internal structure of the nozzle.

[0028] Figure 6It is a schematic diagram illustrating the configuration of the discharge unit.

[0029] Figure 7 This is a block diagram conceptually illustrating the configuration of a control unit.

[0030] Figure 8 This is a schematic diagram illustrating the structure of the first recovery unit.

[0031] Figure 9 It is a schematic diagram illustrating the structure of the first sulfuric acid electrolysis section.

[0032] Figure 10 This is a schematic diagram illustrating the structure of the second recovery unit.

[0033] Figure 11 It is a schematic diagram illustrating the structure of the second sulfuric acid electrolysis section.

[0034] Figure 12 It is a schematic diagram illustrating the structure of the third sulfuric acid electrolysis section.

[0035] Figure 13 This is a flowchart illustrating the regeneration process. DETAILED DESCRIPTION

[0036] The following embodiments will be described with reference to the accompanying drawings. Detailed features and the like are shown in the following embodiments to illustrate the technology, but these are merely examples and are not necessarily required to implement the embodiments.

[0037] The drawings are schematic representations, and for ease of explanation, some components may be omitted or simplified as appropriate. Furthermore, the sizes and positions of components shown in the various drawings are not necessarily accurate representations and may be modified as appropriate. Furthermore, in drawings such as top views, which are not cross-sectional views, hatching may be used to facilitate understanding of the embodiments.

[0038] When piping is drawn in a triangular or T-shaped pattern in the drawings, unless otherwise specified, it means that the three pipes drawn in a straight line are interconnected. When piping is drawn in a quadrilateral or cross pattern in the drawings, unless otherwise specified, it means that the two pipes drawn in a straight line passing through the intersection are not interconnected.

[0039] Arrows attached to lines drawn as pipes in the drawings indicate directions in which fluids flow.

[0040] In the following description, the same components are denoted by the same reference numerals and shown in the figures, and their names and functions are the same, so their detailed description may be omitted in order to avoid redundancy.

[0041] In the description described in the specification of the present application, when a certain component is expressed as “having”, “including” or “having”, it is not intended to be an exclusive expression excluding the presence of other components unless otherwise specified.

[0042] In the descriptions recorded in the specification of this application, ordinal numbers such as "1st" or "2nd" are sometimes used. These words are used for expedient purposes to make the content of the implementation method easier to understand, and the content of the implementation method is not limited to the order that can be generated by these ordinal numbers.

[0043] In the descriptions recorded in the specification of this application, words such as "up", "down", "left", "right", "side", "bottom", "front" or "reverse" are sometimes used to indicate specific positions or directions. These words are used expediently to make the contents of the implementation method easier to understand and have nothing to do with the position or direction when the implementation method is actually implemented.

[0044] In the description of this application, expressions such as "the upper surface of..." or "the lower surface of..." include not only the upper surface or lower surface of the component in question, but also states where other components are formed on the upper or lower surface of the component in question. That is, for example, the expression "B disposed on the upper surface of A" does not preclude the presence of another component "C" between A and B.

[0045] <1. Overview of Substrate Processing Apparatus 1 >

[0046] Figure 1 It is a block diagram schematically showing the configuration of the substrate processing apparatus 1 according to the present invention.

[0047] The substrate processing apparatus 1 includes a supply recovery unit 3 , a discharge unit 5 , a processing unit 6 , a regeneration unit 7 , recovery pipes 110 and 124 , a discharge liquid pipe 160 , and a control unit 90 .

[0048] <1-1. Supply and Recovery Section 3>

[0049] Figure 2 This is a schematic diagram illustrating the configuration of the supply and recovery unit 3. The supply and recovery unit 3 has the function of supplying and recovering the first solution to and from the processing unit 6. The processing unit 6 performs substrate processing. The first solution contains peroxydisulfate ions, typically peroxydisulfuric acid (H2S2O8). As described below, the concentration of peroxydisulfuric acid in the first solution is preferably high.

[0050] The supply recovery unit 3 includes a supply tank 10 , supply pipes 100 and 102 , a discharge liquid pipe 162 , valves 100A, 102A, and 162A, a flow meter 112 , a pump 114 , heaters 103 and 116 , thermometers 105 and 117 , and a filter 119 .

[0051] The first solution (hereinafter also referred to as “regenerated sulfuric acid”) regenerated by the regeneration unit 7 as described below flows through the supply pipe 100 . The regenerated sulfuric acid is supplied from the supply pipe 100 to the supply tank 10 .

[0052] The supply tank 10 functions as a first tank storing the first solution. The valve 100A is provided in the supply pipe 100 and adjusts the flow rate of the regenerated sulfuric acid flowing through the supply pipe 100 under the control of the controller 90 .

[0053] A supply pipe group 106G communicates with the supply pipe 102. The supply pipe 102 has a function of supplying the first solution to the processing unit 6 via the supply pipe group 106G.

[0054] The flow meter 112 , the pump 114 , the heater 116 , the thermometer 117 , the filter 119 , and the valve 102A are provided in series in the supply pipe 102 , for example, in this order.

[0055] The thermometer 117 measures the temperature of the first solution flowing through the supply pipe 102 . The heater 116 heats the first solution so that the temperature measured by the thermometer 117 reaches, for example, 90° C. This temperature adjustment is performed under the control of the control unit 90 .

[0056] The filter 119 removes foreign matter, such as particles, from the first solution flowing through the supply pipe 102 .

[0057] Pump 114 pressurizes the first solution in supply pipe 102 from the bottom of supply tank 10 toward the side opposite to supply tank 10. This pressurization causes the first solution to flow from the bottom of supply tank 10 through supply pipe 102 to supply pipe group 106G. The portion of the first solution that flows through supply pipe 102 and does not flow toward supply pipe group 106G is supplied to regeneration unit 7.

[0058] The control unit 90 controls the substrate processing performed by the processing unit 6 by referring to the processing schedule. The flow rate of the first solution flowing through the supply pipe 102 is adjusted by, for example, adjusting the opening of valve 102A so that the flow rate of the first solution measured by flowmeter 112 is sufficient for the substrate processing. Valve 102A is adjusted under the control of the control unit 90.

[0059] The discharge liquid piping 162 has the function of discharging the first solution from the supply tank 10. A valve 162A is provided on the discharge liquid piping 162 to adjust the flow rate of the first solution flowing through the discharge liquid piping 162 under the control of the controller 90. The first solution discharged from the supply tank 10 via the discharge liquid piping 162 is supplied to the discharge unit 5.

[0060] The thermometer 105 measures the temperature of the first solution flowing through the supply pipe 100 . The heater 103 heats the first solution so that the temperature measured by the thermometer 105 reaches, for example, 90° C. This temperature adjustment is performed under the control of the control unit 90 .

[0061] <1-2. Recovery Pipes 110 and 124 and Drain Pipe 160>

[0062] The recovery pipe 110 is connected to the return pipe group 108G. The first solution supplied from the supply pipe group 106G but not used for substrate processing flows into the return pipe group 108G. The first solution flows from the processing section 6 through the return pipe group 108G into the recovery pipe 110. The first solution flowing into the recovery pipe 110 is supplied to the regeneration section 7.

[0063] The recovery pipe 124 is connected to a waste liquid piping group 122G. The waste liquid used for the first substrate processing (hereinafter referred to as "first waste liquid") flows into the waste liquid piping group 122G. The first waste liquid flows from the processing section 6 through the waste liquid piping group 122G and into the recovery pipe 124. The first waste liquid flowing into the recovery pipe 124 is supplied to the regeneration section 7. The supply of the first waste liquid to the regeneration section 7 can be considered as the recovery of the first waste liquid from the processing section 6 to the regeneration section 7.

[0064] In the regeneration unit 7, the first solution is obtained from the recovered first waste liquid through the regeneration process described below. The regeneration process can reduce the amount of new chemical solution supplied to the substrate processing apparatus 1 and the amount of first waste liquid discharged from the substrate processing apparatus 1, thereby more effectively utilizing resources and contributing to environmentally friendly technologies and production methods.

[0065] A waste liquid piping group 161G communicates with the drain liquid piping 160. Waste liquid after the second substrate processing (hereinafter referred to as "second waste liquid") flows into the waste liquid piping group 161G. The second waste liquid flows from the processing unit 6 through the waste liquid piping group 161G into the drain liquid piping 160. The second waste liquid flowing into the drain liquid piping 160 is then supplied to the discharge unit 5.

[0066] Recovery pipes 110 and 124 and drain pipe 160 are arranged, for example, in pipe space 8. Pipe space 8 is provided, for example, between the location where supply recovery unit 3 is arranged and the space where processing unit 6 is arranged. In pipe space 8, supply pipe group 106G is connected to supply pipe 102, return pipe group 108G is connected to recovery pipe 110, waste pipe group 122G is connected to recovery pipe 124, and waste pipe group 161G is connected to drain pipe 160.

[0067] <1-3. Processing Unit 6>

[0068] Figure 3 Schematic diagram illustrating the structure of the processing unit 6. The processing unit 6 has a plurality of ( Figure 3 In the example, there are 6) processing units 600.

[0069] The substrate processing method using the substrate processing apparatus 1 includes the following steps: spraying a processing liquid onto a substrate W transferred to the processing unit 600 to process the substrate; cleaning the processed substrate W; rotating and drying the cleaned substrate W; and unloading the dried substrate W from the processing unit 600. These steps are performed by controlling the operation of various components of the substrate processing apparatus 1 (e.g., pumps, heaters, valves, or rotary motors) using the control unit 90.

[0070] Each processing unit 600 has valves 106A, 108A, 122A, 160A, 200A, and a nozzle 106B. A supply pipe 106, a return pipe 108, waste liquid pipes 122, 161, and a mixing pipe 200 are introduced into each processing unit 600. The plurality of supply pipes 106 constitute a supply pipe group 106G, the plurality of return pipes 108 constitute a return pipe group 108G, the plurality of waste liquid pipes 122 constitute a waste liquid pipe group 122G, and the plurality of waste liquid pipes 161 constitute a waste liquid pipe group 161G (see FIG. Figure 1 ).

[0071] The first solution flows from the supply pipe 102 into the supply pipe 106 . The valve 106A is provided in the supply pipe 106 and adjusts the flow rate of the first solution flowing through the supply pipe 106 under the control of the controller 90 .

[0072] The first solution flows from nozzle 106B into reflux pipe 108. The first solution flowing into reflux pipe 108 merges with recovery pipe 110 and flows into regeneration unit 7. Valve 108A is provided in reflux pipe 108 and adjusts the flow rate of the first solution flowing into reflux pipe 108 under the control of control unit 90.

[0073] The first waste liquid flows into waste liquid piping 122. The first waste liquid flowing into waste liquid piping group 122G merges in recovery piping 124 and flows into regeneration unit 7. Valve 122A is provided in waste liquid piping 122 and adjusts the flow rate of the first waste liquid flowing into waste liquid piping 122 under the control of control unit 90.

[0074] The second waste liquid flows into waste liquid piping 161. The second waste liquid flowing into waste liquid piping 161 merges with discharge liquid piping 160 and flows into discharge unit 5. Valve 160A is provided in waste liquid piping 161 and adjusts the flow rate of the second waste liquid flowing into waste liquid piping 161 under the control of control unit 90.

[0075] Hydrogen peroxide water is supplied from a hydrogen peroxide water supply source 13 (see Figure 1) flows into the mixing pipe 200. The valve 200A is provided in the mixing pipe 200 and adjusts the flow rate of the hydrogen peroxide solution flowing into the mixing pipe 200 under the control of the control unit 90.

[0076] Nozzle 106B adds hydrogen peroxide to the first solution to form a treatment solution, which is then supplied to substrate W. This addition is not essential for substrate processing using the first solution. This addition increases the temperature of the first solution during substrate processing. This higher temperature improves substrate processing efficiency.

[0077] If the temperature of the first solution before substrate processing is high, then as shown below,

[0078] S2O8 2- →2SO 4- ·

[0079] 2SO 4- +2H2O→2HSO4 2- +2OH·

[0080] 2HSO 4- +xH2O→2H2SO5+xH2

[0081] 2SO 4- +2H2O→2HSO4 2- +2OH·

[0082] Peroxydisulfuric acid is easily decomposed (the symbol "·" represents a free radical; the same applies hereinafter). This decomposition also manifests as the deactivation of peroxydisulfuric acid.

[0083] Before being used for substrate processing, the temperature of the first solution is not increased to suppress its deactivation, and hydrogen peroxide water is added to the first solution during substrate processing, which will help improve the efficiency of substrate processing.

[0084] The nozzle 106B is connected to the supply pipe 106, the return pipe 108, and the mixing pipe 200. The first solution is supplied from the supply pipe 102 to the nozzle 106B via the supply pipe 106 through the valve 106A. Hydrogen peroxide solution is supplied from the hydrogen peroxide solution supply source 13 to the nozzle 106B via the mixing pipe 200 through the valve 200A. The first solution supplied from the supply pipe 106 but not used as the treatment solution is discharged into the nozzle 106B via the return pipe 108 through the valve 108A and into the recovery pipe 110.

[0085] For example, the nozzle 106B adds hydrogen peroxide solution to the first solution and then sprays the solution, or allows the first solution to flow into the return pipe 108 without adding hydrogen peroxide solution, as described below.

[0086] Figure 3 The hydrogen peroxide water supply source 13 is omitted, and Figure 1 Although the example in FIG. 1 shows a case where the hydrogen peroxide solution supply source 13 is provided outside the substrate processing apparatus 1 , it may be provided inside the substrate processing apparatus 1 .

[0087] <1-4. Processing Unit 600>

[0088] Figure 4 It is a schematic diagram schematically illustrating the processing unit 600 and related components. Figure 4 The configuration is shown in Figure 3 The illustrated example is a configuration example of a processing unit 600 on the side of the supply pipe 106 opposite to the supply pipe 102 (downstream side of the first solution flowing into the supply pipe 102; hereinafter also referred to as "downstream side of the supply pipe 102"). Figure 3 The processing unit 600 on the downstream side of the supply pipe 102 of the other supply pipe 106 is also connected to the supply pipe 106. Figure 4 The configuration shown as an example is configured in the same manner.

[0089] The processing unit 600 includes a chamber 80 , a spin chuck 251 , and a processing cup 511 .

[0090] The chamber 80 is box-shaped with an internal space. The spin chuck 251 holds a substrate W in a horizontal position within the chamber 80 while rotating it about a vertical rotation axis Z1. For example, the substrate W is held on the spin chuck 251 with the center of the substrate W positioned on the rotation axis Z1.

[0091] The nozzle 106B discharges the processing liquid toward a predetermined location (eg, the spin base 251A) inside the chamber 80. When the spin base 251A holds the substrate W, the discharge corresponds to the supply of the processing liquid from the nozzle 106B to the substrate W.

[0092] The processing unit 600 may also be connected to a nozzle different from the nozzle 106B for ejecting liquid for other purposes (for example, a nozzle for ejecting other chemical liquids or a nozzle for ejecting a rinse liquid).

[0093] The processing cup 511 includes an outer cup 511A and an inner cup 511B. Both the outer cup 511A and the inner cup 511B are cylindrical in shape and extend along the rotation axis Z1.

[0094] The inner cup 511B surrounds the rotation chuck 251 , and the outer cup 511A surrounds the inner cup 511B.

[0095] Waste liquid pipe 122 is provided at the bottom of chamber 80 , inside outer cup 511A and outside inner cup 511B. Waste liquid pipe 161 is provided at the bottom of chamber 80 , inside inner cup 511B and outside spin chuck 251 .

[0096] The upper end of the inner cup 511B is located below the upper end of the outer cup 511A. The outer cup 511A and the inner cup 511B are vertically moved up and down independently or in conjunction with each other by a lifting mechanism (eg, a motor or cylinder) (not shown).

[0097] When the substrate W is to be held on the spin chuck 251, the upper ends of the outer cup 511A and the inner cup 511B are both located below the spin base 251A. When the substrate W is being processed, the upper end of the outer cup 511A is located above the substrate W held by the spin chuck 251.

[0098] The inner cup 511B can move to a position above the substrate W held on the spin chuck 251 and below the outer cup 511A (hereinafter referred to as the "upper position"). The inner cup 511B can move to a position below the substrate W held on the spin chuck 251 (hereinafter referred to as the "lower position"). Figure 4 the location illustrated in ).

[0099] When performing the first substrate treatment, the inner cup 511B moves to the lower position. The first substrate treatment is, for example, a treatment in which a resist is removed from the substrate W using a treatment solution. Peroxodisulfate ions contribute to the removal of the resist, so a high concentration of peroxodisulfate ions in the first solution contained in the treatment solution is desirable.

[0100] The first waste liquid is caught by the inner side surface of the outer cup 511A. The first waste liquid caught by the outer cup 511A flows into the recovery pipe 124 via the waste liquid pipe 122, and is then supplied to the regeneration unit 7 for the regeneration process described below.

[0101] When performing the second substrate treatment, the inner cup 511B moves to the upper position. The second substrate treatment is, for example, a rinsing treatment for scrubbing the substrate W after the first substrate treatment. Details of the rinsing treatment, the rinsing liquid used to perform the rinsing treatment, and its supply to the substrate W are omitted in this embodiment.

[0102] The second waste liquid is received by the inner side surface of the inner cup 511B. The second waste liquid received by the inner cup 511B is not used for the regeneration process described below, but flows into the discharge liquid pipe 160 via the waste liquid pipe 161 and is then supplied to the discharge unit 5.

[0103] The chamber 80 has a box-shaped wall 250A. An opening 250B is formed in the wall 250A. The substrate W is loaded into the chamber 80 and unloaded from the chamber 80 through the opening 250B.

[0104] The chamber 80 has a movable shutter 250C. The opening 250B is opened or closed by the shutter 250C. The shutter 250C is moved to a closed position ( Figure 4 The opening position of the opening portion 250B (shown by the dotted line) is the same as the opening position of the opening portion 250B ( Figure 4 The solid line indicates the rise and fall between the two.

[0105] The rotary chuck 251 includes a rotary base 251A, a plurality of chuck pins 251B, a rotary shaft 251C, and a rotary motor 251D.

[0106] The rotating base 251A is disk-shaped. A plurality of chuck pins 251B protrude upward from the outer periphery of the upper surface of the rotating base 251A. The plurality of chuck pins 251B grip or release the peripheral edge of the substrate W. The substrate W gripped by the chuck pins 251B faces the rotating base 251A and is held horizontally on the rotating chuck 251. A rotation shaft 251C extends downward from the center of the rotating base 251A. The rotation motor 251D rotates the rotation shaft 251C, thereby rotating the substrate W gripped by the plurality of chuck pins 251B.

[0107] For example, a vacuum adsorption type chuck having a rotation base for vacuum adsorbing the lower surface of the substrate W may be used instead of the spin chuck 251 that uses a plurality of chuck pins 251B to hold the substrate W.

[0108] The exhaust port 515 is provided at the side of the chamber 80. The atmosphere in the chamber 80 is appropriately exhausted to the outside of the chamber 80 through the exhaust port 515. The atmosphere in the processing cup 511 is exhausted by a cup exhaust mechanism (not shown).

[0109] <1-5. Nozzle 106B>

[0110] Figure 5 It is a cross-sectional view illustrating the internal structure of the nozzle 106B.

[0111] The nozzle 106B includes a body 36 , a valve body 37 , a pneumatic actuator 38 , and a discharge port 31 . The body 36 includes a valve chamber 45 .

[0112] The main body 36 includes a flow path 35 for guiding the first solution or treatment liquid. A valve body 37 opens or closes the flow path 35. A pneumatic actuator 38 moves the valve body 37 forward and backward in the axial direction X1 to open or close the flow path 35. The flow path 35 located closer to the discharge port 31 than the valve body 37 communicates with the mixing pipe 200. The flow path 35 located closer to the discharge port 31 than the mixing pipe 200 functions as a flow path 35c for the treatment liquid. The flow path 35 located farther from the discharge port 31 than the valve body 37 branches into flow paths 35a and 35b.

[0113] A pair of joints 48 are connected to the main body 36. Supply pipe 106 is connected to one joint 48, and supply pipe 106 communicates with flow path 35a. Flow path 35a can also be considered a portion of supply pipe 106. Return pipe 108 is connected to the other joint 48, and return pipe 108 communicates with flow path 35b. Flow path 35b can also be considered a portion of return pipe 108.

[0114] The flow path 35a communicates with the supply pipe 106 and the valve chamber 45. The flow path 35b communicates with the return pipe 108 and the valve chamber 45. The flow path 35c communicates with the valve chamber 45 and the discharge port 31.

[0115] The pneumatic actuator 38 includes a cylinder 39, a piston 42, a spring 43, and a rod 44. The cylinder 39 and the valve chamber 45 are arranged along the axial direction X1. The cylinder 39 and the valve chamber 45 are separated by a partition wall 41. The valve body 37 moves forward and backward in the valve chamber 45.

[0116] The cylinder 39 is partitioned by the piston 42 into a front chamber on the partition wall 41 side and a rear chamber sandwiching the piston 42 in the axial direction X1. A spring 43 is installed between the piston 42 and the body 36 on the rear chamber side of the cylinder 39. The spring 43 presses the piston 42 toward the partition wall 41.

[0117] A pair of joints 47 are connected to the body 36. A pipe (not shown) is connected to one joint 47 for transmitting air pressure to the front chamber of the cylinder 39. A pipe (not shown) is connected to the other joint 47 for transmitting air pressure to the rear chamber of the cylinder 39. The transmission of air pressure to either the front chamber or the rear chamber of the cylinder 39 via these pipes and the joint 47 causes the piston 42 to advance and retract within the cylinder 39 along the axial direction X1.

[0118] The rod 44 extends along the axial direction X1 through the partition wall 41. One end of the rod 44 is connected to the piston 42. The other end of the rod 44 is connected to the valve body 37. The valve body 37 is, for example, in the shape of a disk, and its radial direction is perpendicular to the axial direction X1.

[0119] When the piston 42 moves forward and backward in the axial direction X1 in the cylinder 39 , the valve body 37 moves forward and backward in the axial direction X1 in the valve chamber 45 via the rod 44 .

[0120] The valve chamber 45 includes a valve seat surface 46. The valve seat surface 46 faces the partition wall 41 and has, for example, a circular annular shape perpendicular to the axial direction X1. The flow paths 35a and 35b are connected, for example, to the inner edge of the circular annular shape of the valve seat surface 46. When viewed along the forward and backward direction of the valve body 37 (axial direction X1), the flow path 35c is connected to the side of the valve chamber 45.

[0121] The main body 36 includes a cylindrical portion 49. The cylindrical portion 49 protrudes downward, and a discharge port 31 is formed at the lower end thereof. The mixing pipe 200 is introduced to the side of the cylindrical portion 49 and communicates with the flow path 35c.

[0122] When no air pressure is applied to the front and rear chambers of the cylinder 39, the pneumatic actuator 38 is in an inoperative state. At this time, the piston 42 is pushed toward the valve chamber 45 by the spring 43 in the cylinder 39, and the valve body 37 contacts the valve seat surface 46 in the valve chamber 45. Due to this contact, the flow path 35 is closed between the flow paths 35a, 35b and the flow path 35c ( Figure 5 At this time, the piston 42 is located close to the partition wall 41.

[0123] When valves 106A and 108A are opened in this state, the first solution supplied from the supply tank 10 through the supply pipe 106 and the flow path 35a to the nozzle 106B is supplied to the regeneration unit 7 through the flow path 35b, the return pipe 108, and the recovery pipe 110. The state in which the first solution flows from the supply pipe 106 to the return pipe 108 without being used for substrate processing is hereinafter referred to as the "pass-through nozzle state."

[0124] In the nozzle-passing state, the first solution also flows from the supply pipe 102 to the regeneration section 7 without being branched from the supply pipe 102 to the supply pipe 106 .

[0125] When air pressure is applied to the front chamber of cylinder 39 after the nozzle has passed through, piston 42 retreats toward the rear chamber of cylinder 39 against the urging force of spring 43. At this point, valve element 37 leaves valve seat 46 within valve chamber 45. As valve element 37 leaves valve seat 46, flow paths 35a and 35c communicate with valve chamber 45, flow path 35c communicates with valve chamber 45, and flow paths 35a and 35c communicate with flow path 35c.

[0126] The first solution supplied from the supply tank 10 through the supply pipe 106 and the flow path 35a flows into the flow path 35c. At this time, if the valve 200A is opened, the hydrogen peroxide solution flows from the mixing pipe 200 into the flow path 35c and is added to the first solution. The first solution to which the hydrogen peroxide solution is added is ejected from the ejection port 31. The state in which the treatment liquid is ejected from the ejection port 31 is hereinafter referred to as the "ejection state."

[0127] When this ejection state is achieved, if the air pressure supplied to the front chamber of cylinder 39 is stopped, or if the air pressure supplied to the rear chamber of cylinder 39 is stopped simultaneously, piston 42 advances toward the front chamber of cylinder 39 due to the urging force of spring 43. At this point, valve body 37 contacts valve seat 46 within valve chamber 45. As valve body 37 contacts valve seat 46, flow paths 35a and 35b are blocked from valve chamber 45, flow path 35c is blocked from valve chamber 45, and the connection between flow paths 35a and 35b and flow path 35c is closed. This achieves a through-nozzle state.

[0128] Nozzle 106B is in the ejection state ( Figure 5When valve body 37 is separated from valve seat surface 46 (in the state where valve body 37 is separated from valve seat surface 46), valve 106A opens and valve 108A closes. The first solution is supplied to flow path 35c. In the spraying state, valve 200A is also opened, and hydrogen peroxide solution is also supplied from mixing pipe 200 to flow path 35c. The hydrogen peroxide solution is added to the first solution in flow path 35c, and the treated solution is then sprayed out from spray port 31.

[0129] The nozzle 106B helps to generate the processing liquid using the first solution. The processing liquid ejected from the ejection port 31 reaches the upper surface of the substrate W to perform substrate processing.

[0130] As described above, flowing the first solution into nozzle 106B of supply pipe 106 not only in the ejection state but also in the pass-through state helps suppress temperature fluctuations of the first solution in supply pipes 102 and 106, and thus helps suppress temperature fluctuations of the processing liquid supplied for substrate processing. For example, in the pass-through state, the first solution flowing into supply pipe 102 and nozzle 106B is kept at a minimum flow rate sufficient to maintain the temperature of supply pipes 102 and 106.

[0131] <1-6. Discharge Portion 5>

[0132] Figure 6 4 is a schematic diagram illustrating the configuration of the discharge unit 5. The discharge unit 5 has a function of discharging liquid that is not necessary for the substrate processing apparatus 1 from the substrate processing apparatus 1. The discharge unit 5 includes a discharge liquid tank 40 and a valve 40A.

[0133] The first solution is supplied from the supply recovery unit 3, specifically the supply tank 10, to the drain tank 40 via the drain pipe 162. The first waste liquid, and any one or more of the second, third, fourth, and fifth solutions (all described below) are supplied from the regeneration unit 7 via the drain pipe 164 to the drain tank 40. The second waste liquid is supplied from the treatment unit 6 via the drain pipe 160 to the drain tank 40.

[0134] The drain tank 40 stores one or more of the first waste liquid, the second waste liquid, the first solution, the second solution, the third solution, the fourth solution, and the fifth solution. The liquid stored in the drain tank 40 is discharged to the outside of the substrate processing apparatus 1 through a valve 40A. The valve 40A adjusts the flow rate of the liquid discharged from the drain tank 40 under the control of the controller 90.

[0135] <1-7. Control Unit 90>

[0136] Figure 7This block diagram conceptually illustrates the configuration of control unit 90. Control unit 90 can be configured as a conventional computer having electrical circuits. Specifically, control unit 90 includes a central processing unit (CPU) 91, read-only memory (ROM) 92, random access memory (RAM) 93, storage device 94, input unit 96, display unit 97, communication unit 98, and a bus 95 interconnecting these.

[0137] ROM 92 stores basic programs. RAM 93 is used as a work area for CPU 91 when performing predetermined processing. Storage device 94 is composed of a non-volatile storage device (e.g., a flash memory or a hard disk device). Input unit 96 is composed of, for example, various switches or a touch panel, and receives input setting instructions (e.g., processing procedures) from the operator. Display unit 97 is composed of, for example, a liquid crystal display device and indicator lights, and displays various information under the control of CPU 91. Communication unit 98 has a data communication function, for example, via a local area network (LAN).

[0138] The storage device 94 is pre-set with a plurality of modes for controlling the various components of the substrate processing apparatus 1. The CPU 91 executes a processing program 94P, which selects one of these modes and controls the various components in that mode. Furthermore, the processing program 94P may also be stored on a 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 performed by the control unit 90 do not necessarily need to be implemented by software; they may also be implemented by dedicated hardware, such as logic circuits.

[0139] <2. Regeneration Section 7>

[0140] The regeneration unit 7 performs a regeneration process. In the regeneration process, the first electrolysis and the second electrolysis are performed in sequence, and the first solution is generated using the first waste liquid.

[0141] <2-1. First embodiment of the regeneration unit 7>

[0142] Figure 8 It is a schematic diagram illustrating the structure of the first collecting part 7A. Figure 9 It is a schematic diagram illustrating the structure of the first sulfuric acid electrolysis unit 7B.

[0143] The first embodiment of the regeneration unit 7 includes a first recovery unit 7A, a first sulfuric acid electrolysis unit 7B, a recovery pipe 126, and a discharge liquid pipe 164. The first recovery unit 7A and the first sulfuric acid electrolysis unit 7B can be regarded as having the recovery pipe 126 and the discharge liquid pipe 164 in common, or either the first recovery unit 7A or the first sulfuric acid electrolysis unit 7B can be regarded as having the recovery pipe 126 and the discharge liquid pipe 164.

[0144] The first recovery section 7A and the first sulfuric acid electrolysis section 7B are connected via a recovery pipe 126 and a discharge liquid pipe 164 .

[0145] <2-1-1. 1st Collection Section 7A>

[0146] The first recovery section 7A includes recovery tanks 30A, 30B, and 30D, valves 102D, 110D, 124A, 124B, 125A, 125B, 125C, 125D, 136A, 136B, 136D, 164D, 164E, and 164F, a circulation pipe 125 , a pump 136 , and an electrolysis unit 21C.

[0147] Recovery pipe 124 supplies the first waste liquid to recovery tank 30A via valve 124A and supplies the first waste liquid to recovery tank 30B via valve 124B. Recovery tanks 30A and 30B both function as a second tank for storing a second solution. The second solution is a provisional name for a solution containing either or both of the first waste liquid and the third solution described below.

[0148] The valve 124A adjusts the flow rate of the first waste liquid supplied to the recovery tank 30A under the control of the control unit 90 , and the valve 124B adjusts the flow rate of the first waste liquid supplied to the recovery tank 30B under the control of the control unit 90 .

[0149] The valve 164E is provided between the recovery tank 30A and the discharge liquid pipe 164 . The valve 164E adjusts the amount of the second solution supplied from the recovery tank 30A to the discharge unit 5 via the discharge liquid pipe 164 .

[0150] The valve 164F is provided between the recovery tank 30B and the discharge liquid pipe 164. The valve 164F adjusts the amount of the second solution supplied from the recovery tank 30B to the discharge unit 5 via the discharge liquid pipe 164.

[0151] The flow rates are adjusted by valves 164E and 164F under the control of the control unit 90 .

[0152] The recovery tank 30A supplies the second solution to the pump 136 via the valve 136A, and the recovery tank 30B supplies the second solution to the pump 136 via the valve 136B.

[0153] The valves 136A and 136B are both controlled by the control unit 90 and adjust the flow rate of the second solution supplied to the pump 136 .

[0154] The second solution stored in the recovery tank 30A is transported in either or both of the circulation pipe 125 and the recovery pipe 126 via the valve 136A and the pump 136, and the second solution stored in the recovery tank 30B is transported in either or both of the circulation pipe 125 and the recovery pipe 126 via the valve 136B and the pump 136.

[0155] The first recovery unit 7A decomposes the organic matter contained in the first waste liquid through electrolysis performed by the electrolysis unit 21C. This electrolysis generates a third solution from the first waste liquid. Alternatively, the second solution can be electrolyzed to generate the third solution. This electrolysis that decomposes the organic matter is the first electrolysis described above.

[0156] The recovery pipe 110 supplies the first solution to the recovery tank 30D via a valve 110D, and the supply pipe 102 supplies the first solution to the recovery tank 30D via a valve 102D. The recovery tank 30D contributes to cooling the first solution.

[0157] The valves 102D and 110D adjust the flow rate of the first solution supplied to the recovery tank 30D under the control of the controller 90 .

[0158] Valve 164D is provided between recovery tank 30D and discharge liquid piping 164. Valve 164D adjusts the amount of the first solution supplied from recovery tank 30D to discharge unit 5 via discharge liquid piping 164. Recovery tank 30D supplies the first solution to pump 136 via valve 136D. Flow rate adjustment by valves 136D and 164D is performed under the control of controller 90.

[0159] The valve 125D adjusts the flow rate of the fourth solution flowing from the circulation pipe 125 to the recovery pipe 126 under the control of the controller 90. The fourth solution is a temporary name referring to one or both of the first solution and the third solution.

[0160] Before the first electrolysis is performed using the recovery tank 30A, an appropriate amount of the first waste liquid for the first electrolysis is stored in the recovery tank 30A by adjusting the valves 124A and 164E.

[0161] Before the first electrolysis is performed using the recovery tank 30B, an appropriate amount of the first waste liquid for the first electrolysis is stored in the recovery tank 30B by adjusting the valves 124B and 164F.

[0162] Whether the first electrolysis is performed using recovery tank 30A or recovery tank 30B, valve 125D is closed. The first solution contains a small amount of the organic matter, so the first electrolysis is unnecessary and valve 136D is closed.

[0163] When the first electrolysis is performed using recovery tank 30A, valves 124A and 164E are closed, and valves 125A, 136A, and 125C are opened. Pump 136 is used to pump the solution, thereby circulating the third solution through circulation piping 125 between recovery tank 30A and electrolysis unit 21C, and the first electrolysis is performed in electrolysis unit 21C.

[0164] When the first electrolysis is performed using recovery tank 30B, valves 124B and 164F are closed, and valves 125B, 136B, and 125C are opened. Pump 136 is used to pump the solution, thereby circulating the third solution through circulation pipe 125 between recovery tank 30B and electrolysis unit 21C, and the first electrolysis is performed in electrolysis unit 21C.

[0165] During the first electrolysis, it is undesirable for the second solution to have a high temperature. Recovery tanks 30A and 30B store the second solution, and their temperature is lowered to, for example, 60°C or below. Complementarily supplying the first waste liquid to recovery tanks 30A and 30B and performing the first electrolysis using recovery tanks 30A and 30B contributes to improved efficiency of the first electrolysis, compared to a case where only one of recovery tanks 30A and 30B is used for the first electrolysis.

[0166] For example, when valve 124A is open, valve 136A is closed, the first waste liquid is supplied to recovery tank 30A, and valves 125B and 136B are opened, and the first electrolysis is performed using recovery tank 30B. For example, when valve 124B is open, valve 136B is closed, the first waste liquid is supplied to recovery tank 30B, and valves 125A and 136A are opened, and the first electrolysis is performed using recovery tank 30A.

[0167] In the first electrolysis, organic matter is decomposed as follows.

[0168] S2O8 2- →2SO 4- ·

[0169] 2SO 4- +2H2O→2HSO4 2- +2OH·

[0170] C, H (organic matter) + 2SO 4- →2HSO 4- +xCO2+yH2O

[0171] 2HSO 4- +xH2O→2H2SO5+xH2

[0172] C, H (organic matter) + 2OH → xCO2 + yH2O

[0173] The longer the first electrolysis is performed, the more the organic matter is decomposed. For example, the first electrolysis is performed for a time period sufficient to decompose the organic matter to a desired degree.

[0174] After the first electrolysis is completed, valves 125A and 125B are both closed, or valve 125C is closed. After the first electrolysis is completed, either or both valves 136A and 136B are opened. After the first electrolysis is completed, valve 136D is opened.

[0175] The recovery pipe 126 is supplied with the third solution supplied from the recovery tank 30A via valves 136A and 125D, the third solution supplied from the recovery tank 30B via valves 136B and 125D, and the first solution supplied from the recovery tank 30C via valve 136D by the pump 136 .

[0176] The path for generating the third solution by performing the first electrolysis on the second solution is hereinafter referred to as the "first path." For example, valves 125A, 136A, 125C, electrolysis unit 21C, and circulation piping 125 can be considered the first path, which circulates the second solution between the first path and recovery tank 30A. For example, valves 125B, 136B, 125C, electrolysis unit 21C, and circulation piping 125 can be considered the first path, which circulates the second solution between the first path and recovery tank 30B.

[0177] In the first recovery section 7A, the recovery tank 30A and the first path associated with the recovery tank 30A may be provided, but the recovery tank 30B and the first path associated with the recovery tank 30B may be omitted.

[0178] <2-1-2. First sulfuric acid electrolysis unit 7B>

[0179] The first sulfuric acid electrolysis section 7B includes regeneration tanks 20A and 20B, electrolysis units 21A and 21B, circulation pipes 128 and 130 , supply pipes 132 and 134 , and valves 126A and 126B.

[0180] The fourth solution is supplied from recovery pipe 126 to regeneration tank 20A via valve 126A, and to regeneration tank 20B via valve 126B. Valves 126A and 126B are controlled by controller 90 to adjust the flow rate of the supplied fourth solution. "Fourth solution" is a provisional term for either or both the first and third solutions. Both regeneration tanks 20A and 20B can store the fourth solution.

[0181] Both the regeneration tanks 20A and 20B function as a third tank for storing the third solution.

[0182] Circulation piping 128 circulates the fourth solution between regeneration tank 20A and electrolysis unit 21A. During this circulation, electrolysis unit 21A electrolyzes the third solution contained in the fourth solution to produce the first solution. Circulation piping 130 circulates the fourth solution stored in regeneration tank 20B. During this circulation, electrolysis unit 21B electrolyzes the third solution contained in the fourth solution to produce the first solution. This electrolysis is the aforementioned second electrolysis.

[0183] In the second electrolysis, peroxodisulfate ions are generated as shown below.

[0184] 2SO4 2- →S2O8 2- +2e -

[0185] 2HSO 4- →2H + +S2O8 2- +2e -

[0186] The regeneration tanks 20A and 20B both store the first solution obtained by the second electrolysis and the first solution stored in the recovery tank 30D.

[0187] The supply pipe 132 supplies the first solution from the regeneration tank 20A to the supply pipe 100 , and the supply pipe 134 supplies the first solution from the regeneration tank 20B to the supply pipe 100 .

[0188] The circulation pipe 128 is provided with a valve 128A, a pump 140 , a heater 142 , a thermometer 143 , a filter 144 , the electrolysis unit 21A, and a concentration meter 138 .

[0189] The valve 128A adjusts the flow rate of the fourth solution flowing from the regeneration tank 20A to the circulation pipe 128 under the control of the controller 90 .

[0190] Pump 140 delivers the fourth solution flowing through circulation pipe 128. Heater 142 heats the fourth solution flowing through circulation pipe 128. Thermometer 143 measures the temperature of the fourth solution flowing through circulation pipe 128. Filter 144 removes foreign matter, such as particulates, from the fourth solution flowing through circulation pipe 128. Concentrator 138 measures the sulfuric acid concentration of the fourth solution flowing through circulation pipe 128.

[0191] The circulation pipe 130 is provided with a valve 130A, a pump 148 , a heater 150 , a thermometer 151 , a filter 152 , an electrolysis unit 21B, and a concentration meter 146 .

[0192] The valve 130A adjusts the flow rate of the fourth solution flowing from the regeneration tank 20B to the circulation pipe 130 under the control of the controller 90 .

[0193] Pump 148 delivers the fourth solution flowing through circulation pipe 130. Heater 150 heats the fourth solution flowing through circulation pipe 130. Thermometer 151 measures the temperature of the fourth solution flowing through circulation pipe 130. Filter 152 removes foreign matter, such as particulates, from the fourth solution flowing through circulation pipe 130. Concentrator 146 measures the sulfuric acid concentration of the fourth solution flowing through circulation pipe 130.

[0194] The "sulfuric acid concentration" mentioned above includes any of the concentrations of sulfuric acid, peroxymonosulfuric acid, and peroxydisulfuric acid. For example, the duration of the second electrolysis is used to estimate whether the peroxydisulfuric acid concentration exceeds a desired lower limit. If the second electrolysis duration exceeds a predetermined time, the second electrolysis is terminated.

[0195] In the first sulfuric acid electrolysis unit 7B, a pump 154 ​​, a heater 156 , a thermometer 157 , and a filter 158 are provided in the supply pipe 100 .

[0196] The first solution is supplied from the regeneration tank 20A via the supply pipe 132 and the valve 132A to the pump 154 ​​, and the first solution is supplied from the regeneration tank 20B via the supply pipe 134 and the valve 134A to the pump 154 ​​.

[0197] The valve 132A adjusts the flow rate of the first solution flowing through the supply pipe 132 under the control of the control unit 90 , and the valve 134A adjusts the flow rate of the first solution flowing through the supply pipe 134 under the control of the control unit 90 .

[0198] The filter 158 removes foreign matter, such as particles, from the first solution flowing through the supply pipe 100 .

[0199] The thermometer 157 measures the temperature of the first solution flowing through the supply pipe 100 . The heater 156 heats the first solution so that the temperature measured by the thermometer 157 reaches, for example, 90° C. This temperature adjustment is performed under the control of the control unit 90 .

[0200] The first sulfuric acid electrolysis unit 7B includes valves 164A and 164B. Regeneration tank 20A supplies the fourth solution to effluent pipe 164 via valve 164A, while regeneration tank 20B supplies the fourth solution to effluent pipe 164 via valve 164B. Flow rate adjustment by valves 164A and 164B is performed under the control of controller 90.

[0201] Pure water (DIW), hydrogen peroxide solution, or ozone water is supplied to the regeneration tank 20A and the regeneration tank 20B from the pure water supply source 14. The flow rate of the pure water, etc. supplied from the pure water supply source 14 to the regeneration tank 20A can be adjusted by controlling the valve 14A using the control unit 90. Furthermore, the flow rate of the pure water, etc. supplied from the pure water supply source 14 to the regeneration tank 20B can be adjusted by controlling the valve 14B using the control unit 90.

[0202] Sulfuric acid is supplied to the regeneration tank 20A and the regeneration tank 20B from the sulfuric acid supply source 16. The flow rate of the sulfuric acid supplied from the sulfuric acid supply source 16 to the regeneration tank 20A can be adjusted by controlling the valve 16A using the control unit 90. Furthermore, the flow rate of the sulfuric acid supplied from the sulfuric acid supply source 16 to the regeneration tank 20B can be adjusted by controlling the valve 16B using the control unit 90.

[0203] For simplicity of explanation, the second electrolysis is first described using the regeneration tank 20A. Prior to the second electrolysis, the regeneration tank 20A is filled with an appropriate amount of the fourth solution for the second electrolysis by adjusting the valves 126A and 164A.

[0204] During the second electrolysis, valve 132A is closed, and regeneration tank 20A is disconnected from supply pipe 100. Valve 164A is closed, and regeneration tank 20A is disconnected from discharge pipe 164. Valve 126A is closed, and the fourth solution is not supplied from recovery pipe 126 to regeneration tank 20A.

[0205] During the second electrolysis, valve 128A opens, pump 140 operates, and the fourth solution stored in regeneration tank 20A is supplied to electrolysis unit 21A. Electrolysis unit 21A functions as an electrolysis device. As electrolysis unit 21A operates, the third solution contained in the fourth solution undergoes the second electrolysis, generating the first solution, which is then supplied to regeneration tank 20A. This increases the proportion of the first solution in the fourth solution stored in regeneration tank 20A.

[0206] When the second electrolysis is performed in the regeneration tank 20A, the fourth solution may be supplied to the regeneration tank 20B via the valve 126B, and the fourth solution may be discharged from the regeneration tank 20B via the valve 164B. For example, during these processes, the valve 130A is closed.

[0207] When the sulfuric acid concentration measured by the concentration meter 138 is low, for example, the valve 16A is opened to supply sulfuric acid to the regeneration tank 20A. When the sulfuric acid concentration measured by the concentration meter 138 is high, for example, the valve 14A is opened to supply pure water, hydrogen peroxide solution, or ozone water to the regeneration tank 20A.

[0208] For example, when the measured sulfuric acid concentration continues to be within the specified range during the period required for the entire fourth solution stored in the regeneration tank 20A to flow through the electrolysis unit 21A, the measured sulfuric acid concentration can be considered to be the sulfuric acid concentration of the fourth solution stored in the regeneration tank 20A.

[0209] In the regeneration tank 20B, the second electrolysis is similarly performed using the circulation pipe 130, pump 148, heater 150, thermometer 151, and filter 152. At this time, valve 134A is closed, and the regeneration tank 20B is disconnected from the supply pipe 100. Valve 164B is closed, and the regeneration tank 20B is disconnected from the effluent pipe 164. Valve 126B is closed, and the fourth solution is not supplied from the recovery pipe 126 to the regeneration tank 20B.

[0210] During the second electrolysis, valve 130A opens, pump 148 operates, and the fourth solution stored in regeneration tank 20B is supplied to electrolysis unit 21B. Electrolysis unit 21B functions as an electrolysis device. As electrolysis unit 21B operates, the third solution contained in the fourth solution undergoes the second electrolysis, generating the first solution, which is then supplied to regeneration tank 20B. This increases the proportion of the first solution in the fourth solution stored in regeneration tank 20B.

[0211] When the second electrolysis is performed in the regeneration tank 20B, the fourth solution may be supplied to the regeneration tank 20A via the valve 126A, and the fourth solution may be discharged from the regeneration tank 20A via the valve 164A. For example, during these processes, the valve 128A is closed.

[0212] When the sulfuric acid concentration measured by the concentration meter 146 is low, for example, the valve 16B is opened to supply sulfuric acid to the regeneration tank 20B. When the sulfuric acid concentration measured by the concentration meter 146 is high, for example, the valve 14B is opened to supply pure water, hydrogen peroxide water, or ozone water to the regeneration tank 20B.

[0213] For example, when the measured sulfuric acid concentration continues to be within the specified range during the period required for the entire fourth solution stored in the regeneration tank 20B to flow through the electrolysis unit 21B, the measured sulfuric acid concentration can be considered to be the sulfuric acid concentration of the fourth solution stored in the regeneration tank 20B.

[0214] For example, the second electrolysis is performed at a higher temperature than the first electrolysis. For example, the temperature of the fourth solution in the second electrolysis is higher than the temperature of the second solution in the first electrolysis. For example, before performing the first electrolysis in the first recovery section 7A, the second solution is cooled to room temperature in the recovery tanks 30A and 30B. For example, the temperature of the fourth solution in the second electrolysis is raised to 60°C.

[0215] This temperature increase is performed, for example, by referring to the temperature measurement of the thermometer 143 and through the heater 142 under the control of the control unit 90 , or by referring to the temperature measurement of the thermometer 151 and through the heater 150 under the control of the control unit 90 .

[0216] Using the regeneration tank 20A to perform the second electrolysis while using the regeneration tank 20B to supply or discharge the fourth solution or both will help improve the efficiency of the second electrolysis.

[0217] The second electrolysis performed using the regeneration tank 20A and the second electrolysis performed using the regeneration tank 20B may be performed in parallel.

[0218] The path for generating the first solution by performing the second electrolysis on the third solution is hereinafter referred to as the "second path." For example, valve 128A, filter 144, electrolysis unit 21A, and circulation piping 128 can be considered the second path for generating the first solution while filtering the third solution through filter 144. For example, valve 130A, filter 152, electrolysis unit 21B, and circulation piping 130 can be considered the second path for generating the first solution while filtering the third solution through filter 152.

[0219] The supply pipes 100 , 132 , and 134 can be regarded as a third path for supplying the first solution from the regeneration unit 7 , more specifically, the first sulfuric acid electrolysis unit 7B, to the supply tank 10 .

[0220] According to the above operation, the first waste liquid can be used to generate the first solution in the regeneration process, and the first electrolysis and the second electrolysis can be performed sequentially. In addition, since the organic matter contained in the first waste liquid is decomposed in the first electrolysis, when peroxydisulfate ions are generated in the second electrolysis, the organic matter flowing into the circulation pipes 128 and 130 is reduced, thereby extending the life of the filters 144 and 152.

[0221] For example, refer to Figure 8 During the second electrolysis or after the second electrolysis is completed, while valves 136A and 136B are closed, valves 136D, 125D, and 126A are opened to supply the first solution from the recovery tank 30D to the regeneration tank 20A.

[0222] For example, refer to Figure 8 During the second electrolysis or after the second electrolysis is completed, while valves 136A and 136B are closed, valves 136D, 125D, and 126B are opened to supply the first solution from the recovery tank 30D to the regeneration tank 20B.

[0223] In the first sulfuric acid electrolysis unit 7B, the regeneration tank 20A and the second path associated with the regeneration tank 20A may be provided, but the regeneration tank 20B and the second path associated with the regeneration tank 20B may be omitted.

[0224] <2-2. Second embodiment of the regeneration unit 7>

[0225] Figure 10 It is a schematic diagram illustrating the structure of the second collecting part 7C. Figure 11 It is a schematic diagram illustrating the structure of the second sulfuric acid electrolysis section 7D.

[0226] The second embodiment of the regeneration unit 7 includes a second recovery unit 7C, a second sulfuric acid electrolysis unit 7D, a recovery pipe 126, and a discharge liquid pipe 164. The second recovery unit 7C and the second sulfuric acid electrolysis unit 7D can be regarded as having the recovery pipe 126 and the discharge liquid pipe 164 in common, or either the second recovery unit 7C or the second sulfuric acid electrolysis unit 7D can be regarded as having the recovery pipe 126 and the discharge liquid pipe 164.

[0227] The second recovery section 7C and the second sulfuric acid electrolysis section 7D are connected via a recovery pipe 126 and a discharge liquid pipe 164 .

[0228] <2-2-1. Second Collection Section 7C>

[0229] The second recovery unit 7C includes a recovery tank 30C, valves 124C, 136C, 164C, 110C, 102C, and a pump 136 .

[0230] The second recovery section 7C is different from the first recovery section 7A in that the first electrolysis is not performed. The regeneration process, specifically the first electrolysis and the second electrolysis, are both performed in the second sulfuric acid electrolysis section 7D.

[0231] The recovery pipe 124 supplies the first waste liquid to the recovery tank 30C via a valve 124C. The valve 124C is controlled by the control unit 90 to adjust the flow rate of the first waste liquid supplied to the recovery tank 30C.

[0232] By adjusting the valve 124C, an appropriate amount of the first waste liquid for the regeneration process in the second sulfuric acid electrolysis section 7D is supplied to the recovery tank 30C.

[0233] The supply pipe 102 adjusts the flow rate of the first solution supplied to the recovery tank 30C via a valve 102C under the control of the controller 90 . The recovery pipe 110 adjusts the flow rate of the first solution supplied to the recovery tank 30C via a valve 110C under the control of the controller 90 .

[0234] The recovery tank 30C stores the fifth solution, which is a mixture of the first waste liquid and the first solution.

[0235] The valve 164C is provided between the recovery tank 30C and the discharge liquid pipe 164. The valve 164C adjusts the amount of the fifth solution supplied from the recovery tank 30C to the discharge unit 5 via the discharge liquid pipe 164. The flow rate adjustment by the valve 164C is performed under the control of the controller 90.

[0236] The recovery tank 30C supplies the fifth solution to the pump 136 via the valve 136C. The valve 136C adjusts the flow rate of the fifth solution supplied to the pump 136 under the control of the controller 90.

[0237] The fifth solution to be supplied to the second sulfuric acid electrolysis section 7D flows into the recovery pipe 126 by adjusting the valve 136C and operating the pump 136 .

[0238] During the first electrolysis, it is undesirable for the temperature of the first solution to be high. The recovery tank 30C stores the fifth solution, and its temperature is lowered to, for example, 60°C or less. Storing the fifth solution in the recovery tank 30C before it is sent to the second sulfuric acid electrolysis section 7D contributes to improving the efficiency of the first electrolysis in the second sulfuric acid electrolysis section 7D.

[0239] <2-2-2. Second sulfuric acid electrolysis unit 7D>

[0240] The second sulfuric acid electrolysis unit 7D has a first sulfuric acid electrolysis unit 7B (see Figure 9 ) The electrolysis units 21D, 21E, and valves 138A, 140A, 142A, 146A, 148A, and 150A are added.

[0241] For example, valves 138A, 140A, 142A, 146A, 148A, and 150A are all on-off valves, and their opening or closing is controlled by the control unit 90 .

[0242] Valves 138A and 142A are provided in the circulation piping 128. Valve 138A separates the heater 142, thermometer 143, filter 144, electrolysis unit 21A, and concentration meter 138 from the liquid level side of the regeneration tank 20A in the circulation piping 128. Valve 142A separates the heater 142, thermometer 143, filter 144, electrolysis unit 21A, and concentration meter 138 from the pump 140 and valve 128A in the circulation piping 128.

[0243] Circulation piping 128 branches between the liquid level side of regeneration tank 20A and valve 138A, with electrolysis unit 21D installed at this branch. Circulation piping 128 branches between pump 140 and valve 142A, with valve 140A installed at this branch. Valve 140A and electrolysis unit 21D are connected in series between valves 138A and 142A. The order of connection between valve 140A and electrolysis unit 21D may be reversed.

[0244] Valves 146A and 150A are provided in the circulation piping 130. Valve 146A separates the heater 150, thermometer 151, filter 152, electrolysis unit 21B, and concentration meter 146 from the liquid level side of the regeneration tank 20B in the circulation piping 130. Valve 150A separates the heater 150, thermometer 151, filter 152, electrolysis unit 21B, and concentration meter 146 from the pump 148 and valve 130A in the circulation piping 130.

[0245] Circulation piping 130 branches between the liquid level side of regeneration tank 20B and valve 146A, with electrolysis unit 21E installed at this branch. Circulation piping 130 branches between pump 148 and valve 150A, with valve 148A installed at this branch. Valve 148A and electrolysis unit 21E are connected in series between valves 146A and 150A. The order of connection between valve 148A and electrolysis unit 21E may be reversed.

[0246] The fifth solution is supplied to the regeneration tank 20A via valve 126A and to the regeneration tank 20B via valve 126B from the recovery pipe 126. Both valves 126A and 126B are controlled by the controller 90 to adjust the flow rate of the supplied fifth solution.

[0247] The regeneration tank 20A stores the fifth solution until the first electrolysis begins. Since the first electrolysis generates the third solution from the first waste liquid in the fifth solution, the regeneration tank 20A can be said to store both the fifth solution and the third solution, or it can be said to contain both the first and second solutions. In the regeneration tank 20A, the second electrolysis generates the first solution from the third solution. From these perspectives, the regeneration tank 20A can be considered the second tank storing the second solution, or the third tank storing the third solution. Similarly, the regeneration tank 20B can be considered the second tank or the third tank.

[0248] In the second sulfuric acid electrolysis section 7D, with valves 128A and 140A open and valves 138A and 142A closed, the pump 140 and the electrolysis unit 21D operate to perform the first electrolysis on the first waste liquid contained in the fifth solution stored in the regeneration tank 20A.

[0249] The fifth solution stored in regeneration tank 20A is blocked by valves 138A and 142A and, therefore, does not pass through electrolysis unit 21A or filter 144. Instead, it is transported through valves 128A and 140A in circulation piping 128 by the operation of pump 140. The first waste liquid contained in this fifth solution undergoes the first electrolysis in electrolysis unit 21D. As this first electrolysis progresses, the amount of the first waste liquid in regeneration tank 20A decreases, while the amount of the third solution increases.

[0250] The first electrolysis performed using the regeneration tank 20A ends, for example, based on the passage of time, similarly to the first electrolysis in the first recovery unit 7A. At the time when the first electrolysis ends, the regeneration tank 20A substantially stores the fourth solution.

[0251] After the first electrolysis is completed, with valves 128A, 138A, and 142A open and valve 140A closed, pump 140 and electrolysis unit 21A are operated to perform second electrolysis on the third solution contained in the fourth solution stored in regeneration tank 20A.

[0252] The fourth solution stored in regeneration tank 20A is blocked by valve 140A and therefore does not pass through electrolysis unit 21D. Instead, it is delivered through valves 128A, 138A, and 142A in circulation piping 128 by the operation of pump 140. The fourth solution is filtered by filter 144, while the third solution contained in the fourth solution undergoes secondary electrolysis in electrolysis unit 21A. As this secondary electrolysis proceeds, the amount of the third solution in regeneration tank 20A decreases, while the amount of the first solution increases.

[0253] The second electrolysis performed using the regeneration tank 20A ends, for example, based on the passage of time, similarly to the second electrolysis in the first sulfuric acid electrolysis unit 7B. At the time when the second electrolysis ends, the regeneration tank 20A substantially stores the first solution.

[0254] According to the above-described operation, the electrolysis unit 21D can be regarded as a first electrolysis device that performs the first electrolysis, and the electrolysis unit 21A can be regarded as a second electrolysis device that performs the second electrolysis.

[0255] In the second sulfuric acid electrolysis section 7D, with valves 130A and 148A open and valves 146A and 150A closed, the pump 148 and the electrolysis unit 21E operate to perform the first electrolysis on the first waste liquid contained in the fifth solution stored in the regeneration tank 20B.

[0256] The fifth solution stored in regeneration tank 20B is blocked by valves 146A and 150A and, therefore, does not pass through electrolysis unit 21E or filter 152. Instead, it is transported through valves 130A and 148A within circulation piping 130 by the operation of pump 148. The first waste liquid contained in this fifth solution undergoes the first electrolysis in electrolysis unit 21E. As this first electrolysis progresses, the amount of the first waste liquid in regeneration tank 20B decreases, while the amount of the third solution increases.

[0257] The first electrolysis performed using the regeneration tank 20B ends, for example, based on the passage of time, similarly to the first electrolysis in the first recovery unit 7A. At the time of the completion of the first electrolysis, the regeneration tank 20B substantially stores the fourth solution.

[0258] After the first electrolysis is completed, with valves 130A, 146A, and 150A open and valve 148A closed, pump 148 and electrolysis unit 21B are operated to perform second electrolysis on the third solution contained in the fourth solution stored in regeneration tank 20B.

[0259] The fourth solution stored in regeneration tank 20B is blocked by valve 148A and therefore does not pass through electrolysis unit 21E. Instead, it is delivered through valves 130A, 146A, and 150A within circulation piping 130 by the operation of pump 148. The fourth solution is filtered by filter 152, while the third solution contained in the fourth solution undergoes secondary electrolysis in electrolysis unit 21B. As this secondary electrolysis proceeds, the amount of the third solution in regeneration tank 20B decreases, while the amount of the first solution increases.

[0260] The second electrolysis performed using the regeneration tank 20B ends, for example, based on the passage of time, similarly to the second electrolysis in the first sulfuric acid electrolysis unit 7B. At the time of the completion of the second electrolysis, the regeneration tank 20B substantially stores the first solution.

[0261] According to the above-described operation, the electrolysis unit 21E can be regarded as a first electrolysis device that performs the first electrolysis, and the electrolysis unit 21B can be regarded as a second electrolysis device that performs the second electrolysis.

[0262] The operation of the second sulfuric acid electrolysis section 7D except for the first electrolysis performed by the electrolysis units 21D and 21E is the same as that of the first sulfuric acid electrolysis section 7B.

[0263] The first electrolysis performed using the regeneration tank 20A and the first electrolysis performed using the regeneration tank 20B may be performed in parallel. The second electrolysis performed using the regeneration tank 20A and the second electrolysis performed using the regeneration tank 20B may also be performed in parallel.

[0264] The regeneration tank 20A can be used to perform the first electrolysis while the regeneration tank 20B is used to perform the second electrolysis. Alternatively, the regeneration tank 20A can be used to perform the second electrolysis while the regeneration tank 20B is used to perform the first electrolysis. Compared to the case where only one of the regeneration tanks 20A or 20B is used in the second sulfuric acid electrolysis section 7D, the regeneration tanks 20A and 20B complementarily perform the first and second electrolysis, which helps to improve the efficiency of the regeneration process.

[0265] In the second embodiment, for example, valves 128A and 140A, electrolysis unit 21D, and circulation pipe 128 can be considered as a first path, and the second solution circulates between the first path and regeneration tank 20A. For example, valves 130A and 148A, electrolysis unit 21E, and circulation pipe 130 can be considered as a first path, and the second solution circulates between the first path and regeneration tank 20B.

[0266] In the second embodiment, similarly to the first embodiment, for example, valve 128A, filter 144, electrolysis unit 21A, and circulation pipe 128 can be considered as a second path for generating the first solution while filtering the third solution through filter 144. For example, valve 130A, filter 152, electrolysis unit 21B, and circulation pipe 130 can be considered as a second path for generating the first solution while filtering the third solution through filter 152.

[0267] In the second embodiment, similarly to the first embodiment, the supply pipes 100 , 132 , and 134 can be regarded as a third path for supplying the first solution from the regeneration unit 7 , more specifically, the second sulfuric acid electrolysis unit 7D, to the supply tank 10 .

[0268] In the second embodiment, as in the first embodiment, the life of the filters 144 and 152 is extended.

[0269] In the second embodiment, similarly to the first embodiment, the electrolysis units 21A and 21B are not responsible for the first electrolysis, thereby suppressing the degradation of the electrolysis units 21A and 21B.

[0270] In the first embodiment, the valve 136D can be opened or closed exclusively together with the valves 136A and 136B (see Figure 8 By opening or closing, the first solution supplied from the recovery pipe 110 and the supply pipe 102 to the regeneration unit 7 does not need to be regenerated. From this point of view, the first embodiment has the above-mentioned advantages over the second embodiment.

[0271] In the second embodiment, similarly to the first embodiment, for example, the second electrolysis is performed at a higher temperature than the first electrolysis. This temperature control can be achieved by the cooperation of the thermometer 143 and the heater 142 or the cooperation of the thermometer 151 and the heater 150.

[0272] The second sulfuric acid electrolysis unit 7D may also include the regeneration tank 20A and the first and second paths associated with the regeneration tank 20A, but may omit the regeneration tank 20B and the first and second paths associated with the regeneration tank 20B.

[0273] <2-3. Third embodiment of the regeneration unit 7>

[0274] Figure 12 Schematic diagram illustrating the structure of the third sulfuric acid electrolysis unit 7E. The third embodiment of the regeneration unit 7 includes a second recovery unit 7C (see Figure 10), the third sulfuric acid electrolysis section 7E, the recovery pipe 126, and the discharge liquid pipe 164. The second recovery section 7C and the third sulfuric acid electrolysis section 7E may be considered to share the recovery pipe 126 and the discharge liquid pipe 164, or it may be considered that either the second recovery section 7C or the third sulfuric acid electrolysis section 7E has the recovery pipe 126 and the discharge liquid pipe 164.

[0275] The second recovery section 7C and the third sulfuric acid electrolysis section 7E are connected via a recovery pipe 126 and a discharge liquid pipe 164 .

[0276] The third sulfuric acid electrolysis unit 7E also performs the first electrolysis and the second electrolysis similarly to the second sulfuric acid electrolysis unit 7D. In the third embodiment, the second recovery unit 7C also operates similarly to the second embodiment.

[0277] The third sulfuric acid electrolysis unit 7E has a first sulfuric acid electrolysis unit 7B (see Figure 9 ) The structure of valves 144A, 144B, 144C, 152A, 152B, and 152C is added. For example, valves 144A, 144B, 144C, 152A, 152B, and 152C are all on-off valves, and their opening or closing is controlled by the control unit 90.

[0278] Valves 144A and 144B are provided in circulation piping 128. Valve 144A is disposed in circulation piping 128 between thermometer 143 and filter 144. Valve 144B is disposed in circulation piping 128 between electrolysis cell 21A and filter 144. Circulation piping 128 branches off valve 144A between thermometer 143 and electrolysis cell 21A, with valve 144C provided at this branch. Valve 144C can be said to be provided in parallel with the series connection between valve 144A and filter 144, or in parallel with the series connection between valve 144B and filter 144, or in parallel with the series connection between valves 144A and filter 144.

[0279] Valves 152A and 152B are installed in circulation piping 130. Valve 152A is located in circulation piping 130 between thermometer 151 and filter 152. Valve 152B is located in circulation piping 130 between electrolysis cell 21B and filter 152. Circulation piping 130 branches off valve 152A between thermometer 151 and electrolysis cell 21B, with valve 152C installed at this branch. Valve 152C can be said to be installed in parallel with the series connection between valve 152A and filter 152, or in parallel with the series connection between valve 152B and filter 152, or in parallel with the series connection between valves 152A, 152B, and filter 152.

[0280] As in the second embodiment, both the regeneration tanks 20A and 20B can be referred to as the second tank or the third tank.

[0281] The fifth solution is supplied to the regeneration tank 20A via valve 126A and to the regeneration tank 20B via valve 126B from the recovery pipe 126. Both valves 126A and 126B are controlled by the controller 90 to adjust the flow rate of the supplied fifth solution.

[0282] In the third sulfuric acid electrolysis section 7E, with either or both of valves 144A and 144B closed and valves 128A and 144C open, the pump 140 and the electrolysis unit 21A operate to perform the first electrolysis on the first waste liquid contained in the fifth solution stored in the regeneration tank 20A.

[0283] The fifth solution stored in regeneration tank 20A is blocked by either valve 144A or 144B and, therefore, does not pass through filter 144. Instead, it is delivered through valves 128A and 144C in circulation piping 128 by the operation of pump 140. The first waste liquid contained in this fifth solution undergoes first electrolysis in electrolysis unit 21A. As this first electrolysis proceeds, the amount of the first waste liquid in regeneration tank 20A decreases, while the amount of the third solution increases.

[0284] The first electrolysis performed using the regeneration tank 20A ends, for example, based on the passage of time, similarly to the first electrolysis in the first recovery unit 7A. At the time when the first electrolysis ends, the regeneration tank 20A substantially stores the fourth solution.

[0285] After the first electrolysis is completed, with valves 128A, 144A, and 144B open and valve 144C closed, pump 140 and electrolysis unit 21A are operated to perform second electrolysis on the third solution contained in the fourth solution stored in regeneration tank 20A.

[0286] The fourth solution stored in regeneration tank 20A is blocked by valve 144C and, therefore, does not bypass filter 144. Instead, it is delivered through valves 128A, 144A, and 144B into circulation piping 128 by the operation of pump 140. While the fourth solution is filtered by filter 144, the third solution contained in the fourth solution undergoes secondary electrolysis in electrolysis unit 21A. As this secondary electrolysis proceeds, the amount of the third solution in regeneration tank 20A decreases, while the amount of the first solution increases.

[0287] The second electrolysis performed using the regeneration tank 20A ends, for example, based on the passage of time, similarly to the second electrolysis in the first sulfuric acid electrolysis unit 7B. At the time when the second electrolysis ends, the regeneration tank 20A substantially stores the first solution.

[0288] According to the above-described operation, the electrolysis unit 21A can be said to be a first electrolysis device that performs the first electrolysis, and also a second electrolysis device that performs the second electrolysis.

[0289] In the third sulfuric acid electrolysis section 7E, with either or both of valves 152A and 152B closed and valves 130A and 152C open, the pump 148 and the electrolysis unit 21B operate to perform the first electrolysis on the first waste liquid contained in the fifth solution stored in the regeneration tank 20B.

[0290] The fifth solution stored in regeneration tank 20B is blocked by either valve 152A or 152B and, therefore, does not pass through filter 152. Instead, it is transported through valves 130A and 152C within circulation piping 130 by the operation of pump 148. The first waste liquid contained in this fifth solution undergoes first electrolysis in electrolysis unit 21B. As this first electrolysis proceeds, the amount of the first waste liquid in regeneration tank 20B decreases, while the amount of the third solution increases.

[0291] The first electrolysis performed using the regeneration tank 20B ends, for example, based on the passage of time, similarly to the first electrolysis in the first recovery unit 7A. At the time of the completion of the first electrolysis, the regeneration tank 20B substantially stores the fourth solution.

[0292] After the first electrolysis is completed, with valves 130A, 152A, and 152B open and valve 152C closed, pump 148 and electrolysis unit 21B are operated to perform second electrolysis on the third solution contained in the fourth solution stored in regeneration tank 20B.

[0293] The fourth solution stored in regeneration tank 20B is blocked by valve 152C and, therefore, does not bypass filter 152. Instead, it is delivered through valves 130A, 152A, and 152B into circulation piping 130 by the operation of pump 148. While the fourth solution is filtered by filter 152, the third solution contained in the fourth solution undergoes secondary electrolysis in electrolysis unit 21B. As this secondary electrolysis proceeds, the amount of the third solution in regeneration tank 20B decreases, while the amount of the first solution increases.

[0294] The second electrolysis performed using the regeneration tank 20B ends, for example, based on the passage of time, similarly to the second electrolysis in the first sulfuric acid electrolysis unit 7B. At the time of the completion of the second electrolysis, the regeneration tank 20B substantially stores the first solution.

[0295] According to the above-described operation, the electrolysis unit 21B can be said to be a first electrolysis device that performs the first electrolysis, and also a second electrolysis device that performs the second electrolysis.

[0296] The operation of the third sulfuric acid electrolysis section 7E, except for the first electrolysis performed by the electrolysis units 21A and 21B, is the same as that of the first sulfuric acid electrolysis section 7B.

[0297] The first electrolysis performed using the regeneration tank 20A and the first electrolysis performed using the regeneration tank 20B may be performed in parallel. The second electrolysis performed using the regeneration tank 20A and the second electrolysis performed using the regeneration tank 20B may also be performed in parallel.

[0298] The regeneration tank 20A can be used to perform the first electrolysis while the regeneration tank 20B is used to perform the second electrolysis. Alternatively, the regeneration tank 20A can be used to perform the second electrolysis while the regeneration tank 20B is used to perform the first electrolysis. Compared to the case where only one of the regeneration tanks 20A or 20B is used in the third sulfuric acid electrolysis section 7E, the regeneration tanks 20A and 20B complementarily perform the first and second electrolysis, which helps to improve the efficiency of the regeneration process.

[0299] In the third embodiment, for example, valves 128A and 144C, electrolysis unit 21A, and circulation pipe 128 can be considered as a first path, and the second solution circulates between the first path and regeneration tank 20A. For example, valves 130A and 152C, electrolysis unit 21B, and circulation pipe 130 can be considered as a first path, and the second solution circulates between the first path and regeneration tank 20B.

[0300] In the third embodiment, for example, valve 128A, filter 144, valves 144A and 144B, electrolysis unit 21A, and circulation piping 128 can be considered as a second path for generating the first solution while filtering the third solution through filter 144. For example, valve 130A, filter 152, valves 152A and 152B, electrolysis unit 21B, and circulation piping 130 can be considered as a second path for generating the first solution while filtering the third solution through filter 152.

[0301] In the third embodiment, similarly to the first embodiment, the supply pipes 100 , 132 , and 134 can be regarded as a third path for supplying the first solution from the regeneration unit 7 , more specifically, the third sulfuric acid electrolysis unit 7E, to the supply tank 10 .

[0302] In the third embodiment, as in the first embodiment, the life of the filters 144 and 152 is extended.

[0303] In the third embodiment, the electrolytic unit 21C in the first embodiment is unnecessary, and the electrolytic units 21D and 21E in the second embodiment are also unnecessary. From this point of view, the third embodiment has an advantage of being more readily available at a lower cost than the first and second embodiments.

[0304] In the third embodiment, the electrolysis unit 21C of the first embodiment and the electrolysis units 21D and 21E of the second embodiment are not used. Instead, the electrolysis units 21A and 21B serve as both the first and second electrolysis units. From this perspective, both the first and second embodiments have the advantage of being less susceptible to (and less prone to) degradation of the electrolysis units 21A and 21B compared to the third embodiment.

[0305] In the first embodiment, the first solution supplied from the recovery pipe 110 and the supply pipe 102 to the regeneration unit 7 does not need to be regenerated. From this point of view, the first embodiment has the above-mentioned advantage over the third embodiment.

[0306] In the third embodiment, similarly to the first embodiment, for example, the second electrolysis is performed at a higher temperature than the first electrolysis. This temperature control can be achieved by the cooperation of the thermometer 143 and the heater 142 or the cooperation of the thermometer 151 and the heater 150.

[0307] In the third sulfuric acid electrolysis unit 7E, the regeneration tank 20A and the first and second paths associated with the regeneration tank 20A may be provided, but the regeneration tank 20B and the first and second paths associated with the regeneration tank 20B may be omitted.

[0308] <3. Sulfuric acid regeneration treatment>

[0309] The substrate processing apparatus 1 operates as described above to generate the first solution from the first waste liquid. The first solution is supplied to the supply tank 10 as regenerated sulfuric acid to generate the processing liquid.

[0310] Figure 13 This is a flowchart illustrating a regeneration process for obtaining a first solution from a first waste liquid. The regeneration process includes steps S11, S12, S13, S14, S15, S16, and S17. The sulfuric acid regeneration process may further include step S18.

[0311] Step S11 is a step of supplying the first waste liquid to the second tank. In the first embodiment, in step S11, the first waste liquid is supplied from the recovery pipe 124 to the recovery tank 30A via the valve 124A, and the first waste liquid is supplied to the recovery tank 30B via the valve 124B (see Figure 8 ). In the second and third embodiments, in step S11, the first waste liquid is supplied from the recovery pipe 124 through the valve 124C to the recovery tank 30C (see Figure 10 ).

[0312] Step S12 is a step for starting the first electrolysis. In the first embodiment, in step S12, valves 124A, 124B, 125D, 164E, and 164F are closed, valve 125C is opened, and pump 136 and electrolysis unit 21C are operated. When the first electrolysis is performed using recovery tank 30A, valves 125A and 136A are opened. When the first electrolysis is performed using recovery tank 30B, valves 125B and 136B are opened (see FIG. Figure 8 ).

[0313] In the first electrolysis of the first embodiment, the closing valve 136D prevents the first solution stored in the recovery tank 30D from being supplied to the first electrolysis, thereby contributing to reducing the load on the electrolysis unit 21C.

[0314] In the second embodiment, in step S12, valves 132A and 134A are closed. When the first electrolysis is performed using the regeneration tank 20A, in step S12, valves 138A and 142A are closed, valves 128A and 140A are opened, and the pump 140 and the electrolysis unit 21D are operated. When the first electrolysis is performed using the regeneration tank 20B, in step S12, valves 146A and 150A are closed, valves 130A and 148A are opened, and the pump 148 and the electrolysis unit 21E are operated (see Figure 11 ).

[0315] In the third embodiment, in step S12, valves 132A and 134A are closed. When the first electrolysis is performed using the regeneration tank 20A, in step S12, either or both of valves 144A and 144B are closed, valve 144C is opened, and pump 140 and electrolysis unit 21A are operated. When the first electrolysis is performed using the regeneration tank 20B, in step S12, either or both of valves 152A and 152B are closed, valve 152C is opened, and pump 148 and electrolysis unit 21B are operated (see Figure 12 ).

[0316] After the first electrolysis is started in step S12, step S13 is executed. In step S13, it is determined whether the first predetermined time has elapsed since the execution of step S12. Step S13 is repeatedly executed until the result of this determination becomes affirmative.

[0317] The first electrolysis started in step S12 is continued until the first predetermined time has passed. The first predetermined time is the estimated time required for the first electrolysis. The first predetermined time can also be said to be the estimated time required to make the amount of organic matter in the first waste liquid or its ratio lower than the specified value. When the result of the judgment in step S13 becomes affirmative, step S14 is executed.

[0318] Step S14 is a step of stopping the first electrolysis. In the first embodiment, for example, the operation of the electrolysis unit 21C is stopped (see Figure 8 ). In the second embodiment, when the first electrolysis performed using the regeneration tank 20A is stopped, for example, the operation of the electrolysis unit 21D is stopped; when the first electrolysis performed using the regeneration tank 20B is stopped, for example, the operation of the electrolysis unit 21E is stopped (see Figure 11 ). In the third embodiment, when the first electrolysis performed by the regeneration tank 20A is stopped, for example, the operation of the electrolysis unit 21A is stopped; when the first electrolysis performed by the regeneration tank 20B is stopped, for example, the operation of the electrolysis unit 21B is stopped (refer to Figure 12 ).

[0319] In the third embodiment, the electrolysis units 21A and 21B are operated in both the first and second electrolysis operations. Since the second electrolysis is performed after the first electrolysis, the electrolysis units 21A and 21B do not necessarily need to be stopped in step S14.

[0320] Step S15 is a step for starting the second electrolysis. In the first embodiment, in step S15, valve 125C (or valves 125A and 125B) are closed. When the first electrolysis using recovery tank 30A is completed, valve 136A is opened. When the first electrolysis using recovery tank 30B is completed, valve 136B is opened. In both cases, pump 136 is operated (see FIG. Figure 8 ).

[0321] In step S15, valves 132A and 134A are closed. When the second electrolysis is performed using the regeneration tank 20A, valve 128A is opened to operate the pump 140 and the electrolysis unit 21A. When the second electrolysis is performed using the regeneration tank 20B, valve 130A is opened to operate the pump 148 and the electrolysis unit 21B (see Figure 9 ).

[0322] In the second embodiment, in step S15, valves 132A and 134A are closed. When the second electrolysis is performed using the regeneration tank 20A, valves 138A and 142A are opened, and the pump 140 and the electrolysis unit 21A are operated. When the second electrolysis is performed using the regeneration tank 20B, valves 146A and 150A are opened, and the pump 148 and the electrolysis unit 21B are operated (see FIG. 2 ). Figure 11 ).

[0323] In the third embodiment, in step S15, valves 132A and 134A are closed. When the second electrolysis is performed using the regeneration tank 20A, valves 144A and 144B are opened, valve 144C is closed, and the pump 140 and the electrolysis unit 21A are operated. When the second electrolysis is performed using the regeneration tank 20B, valves 152A and 152B are opened, valve 152C is closed, and the pump 148 and the electrolysis unit 21B are operated (see FIG. Figure 12 ).

[0324] After the second electrolysis is started in step S15, step S16 is executed. In step S16, it is determined whether the second predetermined time has elapsed since the execution of step S15. Step S16 is repeatedly executed until the result of this determination becomes affirmative.

[0325] The second electrolysis started in step S15 continues until the second predetermined time has elapsed. The second predetermined time is the estimated time required for the second electrolysis. The second predetermined time can also be said to be the estimated time required for the amount or concentration of the first solution, specifically the amount or concentration of peroxydisulfate ions, to exceed a predetermined value. If the determination result in step S16 is affirmative, step S17 is executed.

[0326] Step S17 is a step of stopping the second electrolysis. In the first embodiment, the second embodiment, and the third embodiment, when the second electrolysis performed using the regeneration tank 20A is to be stopped, for example, the operation of the electrolysis unit 21A is stopped; when the second electrolysis performed using the regeneration tank 20B is to be stopped, for example, the operation of the electrolysis unit 21B is stopped (see Figure 9 、 Figure 11 、 Figure 12 ).

[0327] The sulfuric acid regeneration process also assumes a case where it further includes step S18. Step S18 is a step of supplying the first solution to the first tank after executing step S17. In the first, second, and third embodiments, in step S17, for example, valves 132A and 134A are opened and pump 154 ​​is activated.

[0328] From the above point of view, the substrate processing method of the present invention can be regarded as a method for processing a substrate using a processing liquid, comprising the following steps: supplying a processing liquid containing a first solution to a substrate W, wherein the above-mentioned first solution, for example, contains peroxydisulfate ions; supplying the waste liquid to a second tank storing a second solution (in the case of the first embodiment, it is the recovery tank 30A, 30B, and in the case of the second and third embodiments, it is the regeneration tank 20A, 20B); and performing regeneration treatment.

[0329] The regeneration process can be considered to consist of two steps: the first electrolysis and the second electrolysis. The first electrolysis involves generating the third solution from the second solution in the first path, which circulates the second solution between the first path and the second tank. The second electrolysis involves generating the first solution while filtering the third solution through filters 144 and 152 in the second path, which includes filters 144 and 152. The first solution generated in this way is reused as the treated solution.

[0330] <4. Transformation>

[0331] Concentrators 138 and 146 can sometimes measure the concentration of peroxodisulfuric acid separately from the concentrations of sulfuric acid and peroxomonosulfuric acid (e.g., by spectroscopic analysis). The determination in step S16 is to determine the degree of inactivation of peroxodisulfuric acid. In this case, the determination condition in step S16 can be changed to "the concentration of peroxodisulfuric acid has not reached a predetermined concentration."

[0332] In the second and third embodiments, a configuration in which the circulation pipe 125, the electrolysis unit 21C, and the valves 125A, 125B, and 125C are removed from the first recovery section 7A may be employed in place of the second recovery section 7C.

[0333] Furthermore, it is of course possible to appropriately combine all or part of the above-mentioned embodiments and various modifications within a range that does not conflict with each other.

[0334] [Description of Reference Numerals]

[0335] 1: Substrate processing equipment

[0336] 10: Supply tank

[0337] 20A, 20B: Regeneration tank

[0338] 30A, 30B: Recovery tank

[0339] 21A, 21B, 21C, 21D, 21E: Electrolysis units

[0340] 100, 132, 134: Supply piping

[0341] 125, 128, 130: Circulation piping

[0342] 106B: Nozzle

[0343] 125A, 125B, 125C, 128A, 130A, 136A, 136B, 140A, 148A, 144A, 144B, 144C, 152A, 152B, 152C: valve

[0344] 144, 152: Filter

[0345] W: substrate

Claims

1. A substrate processing device, a device for processing a substrate using a processing liquid, wherein: have: a nozzle supplied with a first solution containing peroxodisulfate ions and supplying the processing liquid containing the first solution to the substrate; a first tank storing the first solution; a second tank supplied with waste liquid and storing a second solution, wherein the waste liquid is the processing liquid after the substrate is processed; a first path, wherein the second solution is circulated between the first path and the second tank, and the second solution is subjected to first electrolysis to generate a third solution; a second path having a filter, wherein the third solution is filtered through the filter while performing second electrolysis to generate the first solution; and The third path supplies the first solution to the first tank.

2. The substrate processing apparatus according to claim 1, wherein: The first path has a first electrolysis device for performing the first electrolysis. The second path mentioned above has: a third tank storing the third solution; and The second electrolysis device circulates the third solution between the second electrolysis device and the third tank to perform the second electrolysis.

3. The substrate processing apparatus according to claim 1, wherein: The second tank is included in both the first path and the second path, and The third solution is circulated between the second path and the second tank.

4. The substrate processing apparatus according to claim 3, wherein: The first path has a first electrolysis device for performing the first electrolysis. The second path includes a second electrolysis device for performing the second electrolysis.

5. The substrate processing apparatus according to claim 3, wherein: The second path further includes a first on-off valve connected in series with the filter. The first path mentioned above has: a second on-off valve provided in parallel with the series connection of the filter and the first on-off valve; and an electrolysis device, which is also shared by the second path; and The electrolysis device performs the first electrolysis when the first on-off valve is closed and the second on-off valve is opened. The electrolysis device performs the second electrolysis when the second on-off valve is closed and the first on-off valve is opened.

6. The substrate processing apparatus according to any one of claims 1 to 5, wherein: The second electrolysis is performed at a higher temperature than the first electrolysis.

7. A substrate processing method, a method for processing a substrate using a processing liquid, wherein: The following steps are involved: supplying the treatment solution containing a first solution to the substrate, wherein the first solution contains peroxydisulfate ions; supplying a waste liquid to a tank storing a second solution, wherein the waste liquid is the treatment liquid after the substrate has been subjected to the treatment; performing first electrolysis on the second solution in a first path for circulating the second solution between the first path and the tank to generate a third solution; and In the second path having the filter, the second electrolysis is performed while the third solution is filtered through the filter to generate the first solution.

Images