JP2020035880A - Cleaning system - Google Patents

Abstract

To provide a cleaning system which can early detect a breakage of an electrolysis cell electrode, in a cleaning system which performs cleaning by passing an electrolytic solution through an electrolytic cell having an electrode, and making electric conduction to cause an electrolytic reaction, using an electrolytic solution generated by the reaction.SOLUTION: A cleaning system 1 includes a batch-type processing device 2 and an electrolytic reactor 3 which supplies an electrolytic solution S to the processing device 2. The processing device 2 includes: a processing tank 21 in which the electrolytic solution S is stored; and a return line 22 and a discharge line 23 connected to the processing tank 21, so as to process a processing target member T, such as a semiconductor substrate, immersed in the processing tank 21. The electrolytic reactor 3 includes an electrolytic cell 31, and the return line 22 having a solution feed pump 32 is connected to the inlet side of the electrolytic cell 31, whereas a solution feed line 33 is connected to the outlet side, and the end of the solution feed line 33 communicates with a storage tank 34. In the middle of the solution feed line 33, a supply valve 35 and a fine particle counter 36 are provided.SELECTED DRAWING: Figure 1

Description

  The present invention provides an electrolytic reaction by passing an electrolytic solution through an electrolytic cell provided with electrodes to cause an electrolysis reaction, producing an electrolytic solution containing a large amount of active ingredients by the reaction, and washing with the electrolytic solution generated. In particular, the present invention relates to a cleaning system capable of detecting breakage of an electrode of an electrolytic cell.

  In the process of removing and cleaning resist residues, fine particles, metals, natural oxide films, and the like in the wafer cleaning technology in the semiconductor manufacturing process, sulfuric acid is produced by electrolyzing sulfuric acid with an electrolytic reactor equipped with an electrolytic cell. Cleaning with persulfuric acid is performed. In addition, it is also practiced to electrolyze ammonia, hydrochloric acid, or the like, and to wash semiconductor materials made of various metals with the electrolytic solution.

  In a cleaning system for performing such cleaning, it is desirable to use a conductive diamond electrode having diamond exposed on the surface from the viewpoint of efficient oxidation of a solution to be electrolyzed such as sulfuric acid, ammonia water, or hydrochloric acid. In order to achieve this, it is desired to use an electrolytic cell in which the size of the electrolytic reaction device for performing the electrolytic treatment is small. In an electrolytic cell using a conductive diamond electrode, the electrodes can be arranged to face each other, and an electrolytic reaction can be caused by energizing the electrodes while passing an electrolytic solution through the gap. Further, in order to increase the electrolysis efficiency, it is desired to use an electrolysis cell using many electrode plates.

  The electrodes in the electrolysis cell of such an electrolysis reactor are very thin, so that there is a possibility that the electrodes may be damaged in a use state where the inflow pressure of the electrolyte is large. In particular, when a diamond electrode is used as an electrode, the electrode is not easily durable because of low durability. When the broken electrode is mixed into the electrolytic solution, it has a problem that the subsequent cleaning process is adversely affected and the throughput is reduced. Therefore, it is required to quickly detect the damage of the electrode in the electrolytic cell of the electrolytic reaction device and to minimize the adverse effect on the cleaning process.

  The present invention has been made in view of the above-described problems, and causes an electrolysis reaction to occur by passing electricity while passing an electrolytic solution through an electrolytic cell provided with electrodes, thereby causing an electrolytic solution to be generated by the electrolytic solution. It is an object of the present invention to provide a cleaning system capable of early detection of breakage of an electrode of an electrolytic cell in a cleaning system for performing cleaning.

  In order to achieve the above object, the present invention has a plurality of electrolysis cells having at least one pair of electrodes having an anode and a cathode, and an electrolysis reaction device for electrolyzing a solution by electrolysis, and electrolysis by the electrolysis reaction device. A processing device for processing the material to be processed with the electrolytic solution, a liquid sending line for sending the electrolytic solution from the electrolytic reaction device to the processing device, and a return line for returning the electrolytic solution supplied to the processing device to the electrolytic reaction device And a cleaning system provided with fine particle measuring means in a liquid sending line between the electrolytic reaction device and the processing device (Invention 1).

  The electrolytic solution produced by the electrolytic reaction device usually contains only a small amount of fine particles. Therefore, if large particles or debris is included, it is highly likely that it is caused by damage to the electrodes of the electrolytic cell. Therefore, according to the invention (Invention 1), a particle measuring means is provided at the subsequent stage of the electrolytic reaction apparatus, and the presence or absence of particles of a predetermined size is monitored, and this can determine the damage of the electrode based on the detection result. .

  In the above invention (Invention 1), the electrode of the electrolytic cell is preferably a diamond electrode having diamond exposed on the surface (Invention 2).

  According to this invention (Invention 2), the diamond electrode can be electrolyzed at a high current density, and thus has excellent electrolysis ability. However, the diamond electrode is easily broken, so that it is necessary to detect the breakage of the electrode.

  In the above inventions (Inventions 1 and 2), the measurement upper limit of the fine particle measuring means is preferably 10 μm or more (Invention 3).

  According to this invention (Invention 3), the electrolytic solution produced by the electrolytic reaction apparatus usually contains only a small amount of fine particles, and fine particles of 10 μm or more may be caused by damage to the electrodes of the electrolytic cell. Therefore, the breakage of the electrode can be determined by detecting the fine particles of 10 μm or more.

  In the above inventions (Inventions 1 to 3), the solution to be electrolyzed preferably contains sulfuric acid, hydrochloric acid or ammonia (Invention 4).

  According to this invention (Invention 4), an electrolytic solution obtained by performing an electrolytic reaction on a solution containing sulfuric acid, hydrochloric acid, or ammonia is suitable for treating a semiconductor substrate or the like in which various metals are exposed. Detecting breakage of the electrode is important because broken electrodes entering the electrolytic solution have a particularly adverse effect on the subsequent cleaning process.

  According to the present invention, since the electrolytic reaction device of the cleaning system that circulates the electrolytic solution between the electrolytic reaction device and the treatment device is provided with a particle measurement unit that can detect particles having a predetermined particle size or more at the subsequent stage, By monitoring the presence or absence of fine particles having a predetermined particle size or more in the electrolytic solution by the fine particle measuring means, it is possible to determine the breakage of the electrode. This can minimize the adverse effects of the electrode damage to the cleaning process.

1 is a system diagram illustrating a cleaning system according to a first embodiment of the present invention. FIG. 4 is a system diagram illustrating a cleaning system according to a second embodiment of the present invention. FIG. 9 is a system diagram illustrating a cleaning system according to a third embodiment of the present invention. FIG. 11 is a system diagram illustrating a cleaning system according to a fourth embodiment of the present invention. FIG. 13 is a system diagram illustrating a process of determining electrode damage in the cleaning system according to the fourth embodiment. FIG. 13 is a system diagram illustrating a process of determining electrode damage in the cleaning system according to the fourth embodiment. FIG. 4 is a system diagram showing a cleaning system of Comparative Example 1. FIG. 9 is a system diagram illustrating a cleaning system of Comparative Example 2.

  Hereinafter, the cleaning system of the present invention will be described with reference to FIGS. The embodiments described below are for facilitating the understanding of the present invention, and do not limit the present invention in any way.

[Cleaning system]
FIG. 1 shows a cleaning system according to a first embodiment of the present invention. In FIG. 1, a cleaning system 1 is a batch-type process in which a process of immersing, cleaning (processing), and removing a member to be processed T is sequentially repeated. The apparatus includes an apparatus 2 and an electrolytic reaction apparatus 3 for supplying an electrolytic solution S to the processing apparatus 2.

(Processing equipment)
The processing apparatus 2 has a processing tank 21 in which the electrolytic solution S is stored, a return line 22 and a discharge line 23 connected to the processing tank 21, and a processing target such as a semiconductor substrate immersed in the processing tank 21. The member T is processed.

(Electrolytic reactor)
The electrolysis reaction device 3 includes an electrolysis cell 31. A return line 22 having a liquid feed pump 32 is connected to the inlet side of the electrolysis cell 31, and a liquid feed line 33 is connected to the outlet side. The end of the liquid sending line 33 communicates with the storage tank 34. In the middle of the liquid sending line 33, a supply valve 35 and a fine particle meter 36 as fine particle measuring means are provided. In the drawings, the black color of the valve indicates an open state and the white color indicates a closed state. Further, a supply line 37 communicating with the processing tank 21 is connected to the storage tank 34. Reference numeral 38 denotes a supply pump.

  In the electrolytic reaction device 3 as described above, the electrolytic cell 31 uses a diamond electrode as an anode and a cathode in the present embodiment. Since a diamond electrode can be electrolyzed at a high current density, it has excellent electrolysis ability. Further, as the fine particle meter 36, those having a measurement upper limit of fine particles of 10 μm or more can be suitably used.

(Electrolyte)
The stock solution (electrolyte solution) of the electrolytic solution S may be any one that is electrically decomposable and used for etching metal, etc., such as sulfuric acid, hydrochloric acid, phosphoric acid, hydrofluoric acid, aqueous ammonia, and aqueous hydrogen peroxide. And the like. In particular, the electrolytic solution S obtained by performing an electrolytic reaction on a solution containing sulfuric acid, hydrochloric acid, or aqueous ammonia is suitable for treating a semiconductor substrate or the like in which various metals are exposed. Therefore, sulfuric acid, hydrochloric acid, or ammonia may be used as a stock solution. preferable.

  However, it is preferable that the electrolytic solution S does not contain particles of 10 μm or more, and substantially does not contain fine particles of 0.1 μm or more, particularly fine particles of 100 nm or more. Here, the phrase “substantially not contained” may be defined in advance, for example, as a state in which the number of fine particles of these sizes is equal to or smaller than a predetermined number (eg, equal to or smaller than 1) in 1 mL.

(Washing process)
Next, a method for cleaning a member to be processed T such as a semiconductor substrate using the above-described cleaning system 1 will be described.

  First, an electrolytic treatment is performed by supplying a stock solution of the electrolytic solution S to the electrolytic cell 31. At this time, as shown in FIG. 1, the supply valve 35 is open, and the manufactured electrolytic solution S is stored in the storage tank 34 from the liquid sending line 33. When a predetermined amount of the electrolytic solution S is accumulated, the supply pump 38 is operated to send the electrolytic solution S from the supply line 37 to the processing tank 21 of the processing apparatus 2, and the electrolytic solution S in the processing tank 21 reaches a predetermined amount. Then, the processing can be performed by immersing the plurality of members to be processed T for a predetermined time. Then, the concentration of the effective component of the electrolytic solution S used for the treatment in the treatment tank 21 decreases with the treatment, so that the electrolytic solution is returned to the electrolytic cell 31 via the return line 22 by the liquid sending pump 32 and subjected to the electrolytic treatment. The regenerated electrolytic solution S is stored in a storage tank 34 via a liquid sending line 33. In this way, by repeating the circulation of the electrolyte S in the liquid supply line 33, the supply line 37, and the return line 22, it is possible to continuously perform the processing while sequentially replacing the member to be processed T.

  In such a washing step, the anode and the cathode of the electrolytic cell 31 are diamond electrodes. This diamond electrode has poor durability and may crack during use. When the broken electrode is mixed with the electrolytic solution S, it has an adverse effect on the cleaning process of the member to be processed T in the processing tank 21, and the throughput is reduced. Therefore, in the present embodiment, a fine particle meter 36 is provided in the liquid feed line 33 at the subsequent stage (outlet side) of the electrolytic cell 31 to monitor fine particles in the electrolytic solution S. In a normal state (the diamond electrode is not damaged), the electrolytic solution S does not substantially contain fine particles of 0.1 μm or more, particularly fine particles of 100 nm or more. When the diamond electrode is damaged in the cell 31, large fine particles or fragments are contained in the electrolyte S. Therefore, in the present embodiment, since the upper limit of measurement is 10 μm or more as the fine particle meter 36, fine particles of 10 μm or more can be detected, and when this is detected, it can be determined that the diamond electrode is broken. it can. For example, if fine particles or fragments of 10 μm or more are detected at a rate exceeding 1 in 1 mL, it may be determined that the diamond electrode has been damaged. Then, the supply valve 35 may be closed and the electrolytic cell 31 may be replaced.

  Next, a cleaning system according to a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the cleaning system 1 is a so-called single-wafer system for cleaning wafers T1 as members to be processed one by one, and has basically the same configuration as that of the first embodiment described above. Are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 2, a wafer T1 as a member to be cleaned, which is a cleaning target of the cleaning system 1 in this embodiment, is installed in a processing chamber 21A, and a nozzle 37A provided at the tip of a supply line 37 is connected to the processing chamber 21A. It is provided facing 21A.

  As in the cleaning system 1 according to the second embodiment, the members to be processed are not only immersed in the electrolytic solution S, but also cleaned one by one by discharging the electrolytic solution S from the nozzle 37A to the wafer T1 to be processed. The processing can be performed in the same manner.

  Next, a cleaning system according to a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, the cleaning system 1 has basically the same configuration as the above-described first embodiment, except that the cleaning system 1 performs processing in a plurality of electrolytic cells. Detailed description is omitted. In FIG. 3, the electrolysis reaction device 3 of the cleaning system 1 has a plurality of (two in this embodiment) electrolysis cells, that is, first and second electrolysis cells 31A and 31B, and the electrolysis cells 31A and 31B. A first return line 22A and a second return line 22B, which are branched from the return line 22 having the liquid feed pump 32, are connected to the inlet side. On the other hand, one liquid sending line 33A and the second liquid sending line 33B are connected to the outlet side, respectively, and the ends thereof communicate with the storage tank. In the middle of the first liquid sending line 33A and the second liquid sending line 33B, a first fine particle meter 36A and a second fine particle meter 36B as fine particle measuring means are provided, respectively.

  In the present embodiment as described above, the first fine particle meter 36A monitors fine particles in the electrolytic solution S discharged from the first electrolytic cell 31A to determine the breakage of the diamond electrode of the first electrolytic cell 31A. At the same time, the breakage of the diamond electrode of the second electrolytic cell 31B is determined by monitoring the fine particles in the electrolytic solution S discharged from the second electrolytic cell 31B by the second fine particle meter 36B. As described above, by setting the fine particle meters 36A and 36B for the plurality of electrolytic cells 31A and 31B, respectively, and monitoring the behavior of the fine particles of the electrolytic solution S, a crack in the electrolytic cell can be detected.

  Further, a cleaning system according to a fourth embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the cleaning system 1 has the same configuration as that of the above-described third embodiment, and thus the same configuration is denoted by the same reference numeral, and detailed description thereof will be omitted. In the present embodiment, the electrolysis reaction device 3 of the cleaning system 1 is a device in which the number of particle counters is one instead of two in the third embodiment, and a plurality (two in this embodiment) of electrolysis cells, ie, It has first and second electrolysis cells 31A and 31B, and a first return line 22A and a second return line branched from a return line 22 having a liquid feed pump 32 at the inlet side of the electrolysis cells 31A and 31B. 22B are connected to each other, while the first liquid supply line 33A and the second liquid supply line 33B are connected to the outlet side, respectively, and the first electrolytic cell 31A is connected to the first supply valve 35A and the second supply valve 35A. The third supply valve 35C allows the liquid to flow through both the first liquid supply line 33A and the second liquid supply line 33B so as to be switchable, while the second electrolytic cell 31B also has the second supply valve. 5B and the fourth supply valve 35D, the liquid can be switchably passed through both the second liquid supply line 33B and the first liquid supply line 33A, and the first liquid supply line 33A and the second liquid supply line 33A. The ends of the liquid sending lines 33B communicate with the storage tanks 34, respectively. In the middle of the first liquid sending line 33A, a fine particle meter 36 as fine particle measuring means is provided.

  Next, a method for cleaning a member to be processed T such as a semiconductor substrate using the above-described cleaning system 1 will be described.

(Washing process)
First, an undiluted solution of the electrolytic solution S is supplied to the first electrolytic cell 31A and the second electrolytic cell 31B to perform an electrolytic treatment. At this time, as shown in FIG. 4, in the first electrolytic cell 31A, the liquid can be passed through the first liquid sending line 33A. On the other hand, in the second electrolytic cell 31B, the second supply valve 35B is open and the fourth supply valve 35D is closed, so that the liquid can be passed through the first liquid supply line 33A. Thus, the electrolytic treatment is performed in both the first electrolytic cell 31A and the second electrolytic cell 31B. The electrolytic solution S produced here is temporarily stored in the storage tank 34 from the first liquid sending line 33A. Is done. When a predetermined amount of the electrolytic solution S is accumulated, the supply pump 38 is operated to send the electrolytic solution S from the supply line 37 to the processing tank 21 of the processing apparatus 2, and the electrolytic solution S in the processing tank 21 reaches a predetermined amount. Then, the processing can be performed by immersing the plurality of members to be processed T for a predetermined time. Then, the electrolytic solution S used for the treatment is returned from the return lines 22A and 22B to the first electrolytic cell 31A and the second electrolytic cell 31B while circulating through the return line 22 by the liquid supply pump 32, and the electrolytic treatment is continued. However, the electrolytic solution S manufactured here is stored in the storage tank 34 via the first liquid sending line 33A. By repeatedly circulating the electrolytic solution S in such a circulation line, the member to be processed T can be continuously processed.

  In such a washing step, the anode and the cathode of the first electrolytic cell 31A and the second electrolytic cell 31B are diamond electrodes. Diamond electrodes have poor durability and may crack during use. Therefore, in the present embodiment, a fine particle meter 36 is provided in the first liquid sending line 33A to monitor fine particles in the electrolytic solution S, and it is determined that the diamond electrode is broken by detecting fine particles of 10 μm or more. be able to. For example, if fine particles or fragments of 10 μm or more are detected at a rate exceeding 1 in 1 mL, it can be determined that the diamond electrode has been damaged.

(Identification of damaged electrolysis cell)
In the above process, it is known that the diamond electrode has been damaged, but it cannot be determined which diamond electrode of the first electrolytic cell 31A or the second electrolytic cell 31B has been damaged. Therefore, cleaning is performed by switching each valve by control means (not shown). For example, as shown in FIG. 5, in the first electrolytic cell 31A, since the first supply valve 35A is open and the third supply valve 35C is closed, the liquid is passed through the first liquid supply line 33A. It is possible. On the other hand, the second electrolysis cell 31B closes the second supply valve 35B and opens the fourth supply valve 35D, so that the flow line from the first liquid supply line 33A to the second liquid supply line 33B. Switch. That is, since only the electrolytic solution S generated in the first electrolytic cell 31A passes through the first liquid sending line 33A, only the fine particles in the electrolytic solution S flowing through the first liquid sending line 33A are removed. When monitoring with the fine particle meter 36 and detecting fine particles of 10 μm or more, it can be determined that the diamond electrode of the first electrolytic cell 31A has been damaged. In that case, the first supply valve 35A may be closed and the first electrolytic cell 31A may be replaced. On the other hand, if no detection is made, it can be determined that the diamond electrode of the second electrolytic cell 31B has been damaged. In that case, the fourth supply valve 35D may be closed and the second electrolytic cell 31B may be replaced.

  However, the detection of fine particles by the fine particle meter 36 in the normal cleaning process may be erroneous. Therefore, as shown in FIG. 6, in the first electrolytic cell 31A, by closing the first supply valve 35A and opening the third supply valve 35C, the liquid supply route is changed from the first liquid supply line 33A to the first liquid supply line 33A. Switch to the second liquid sending line 33B. On the other hand, in the second electrolytic cell 31B, the second supply valve 35B is opened and the fourth supply valve 35D is closed to supply the electrolytic solution S to the first liquid supply line 33A. That is, since only the electrolytic solution S generated in the second electrolytic cell 31B passes through the first liquid sending line 33A, only the fine particles in the electrolytic solution S flowing through the second liquid sending line 33B are removed. When the fine particles of 10 μm or more are detected by monitoring with the total 36, it can be determined that the diamond electrode of the second electrolytic cell 31B has been damaged. In that case, the second supply valve 35B may be closed and the second electrolytic cell 31B may be replaced.

  As described above, the cleaning system of the present invention has been described based on the above embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made. For example, the electrolytic solution S can be various solutions. Further, in the fourth embodiment, the operation of specifying the damaged electrolytic cell may be performed by appropriately combining the operations shown in FIGS. 5 and 6.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited by these descriptions.

[Example 1]
Using a batch-type cleaning system shown in FIG. 1, a silicon wafer having a TiN film formed on its surface using sulfuric acid (H ₂ SO ₄ ) as a stock solution of an electrolytic solution was cleaned. As the fine particle meter 36, one capable of detecting fine particles of 10 μm to 1 mm was used. The treatment tank 21 is provided with a sulfuric acid supply device for replenishing sulfuric acid and an ultrapure water supply device (not shown), and the concentration and amount of sulfuric acid can be adjusted by control means (not shown).

  After the cleaning of the silicon wafer is continued for about 12 months using the cleaning system 1 as described above, the diamond electrode of the electrolytic cell 31 is damaged, and the fine particles of the electrolytic solution S flowing through the liquid sending line 33 are measured by the fine particle meter 36. Then, the time required to detect fine particles of 10 μm to 1 mm was measured. Table 1 shows the results.

[Comparative Example 1]
As shown in FIG. 7, a silicon wafer having a TiN film formed on its surface using sulfuric acid (H ₂ SO ₄ ) as a stock solution of an electrolytic solution is cleaned using a batch cleaning system having no fine particle meter 36 in FIG. went. In FIG. 7, the same components as those in FIG. 1 are denoted by the same reference numerals.

  After the cleaning of the silicon wafer was continued for about 12 months using the cleaning system 1 as described above, the diamond electrode of the electrolytic cell 31 was damaged, and the result of detecting the damage of the diamond electrode by the leak sensor provided in the electrolytic cell 31 was obtained. Are also shown in Table 1.

  As is clear from Table 1, the cleaning system of Example 1 required only 10 seconds from breakage of the diamond electrode to detection, whereas Comparative Example 1 detected by the leak sensor required 5 minutes. From these results, in Example 1, the operation can be stopped in about ten seconds after the electrode is broken, but in Comparative Example 1, it is predicted that the electrolytic solution S containing the fine particles is supplied to the processing tank 21 and the throughput is reduced. Is done.

[Example 2]
Using a batch type cleaning system shown in FIG. 3, a silicon wafer having a TiN film formed on its surface using sulfuric acid (H ₂ SO ₄ ) as a stock solution of an electrolytic solution was cleaned. The treatment tank 21 is provided with a sulfuric acid supply device for replenishing sulfuric acid and an ultrapure water supply device (not shown), and the concentration and amount of sulfuric acid can be adjusted by control means (not shown).

  After the cleaning of the silicon wafer is continued for about 12 months using the cleaning system 1 as described above, the diamond electrode of the first electrolytic cell 31A is damaged, and the first liquid supply line 33A and the second liquid supply line 33B are damaged. The fine particles of the electrolyte S flowing through are measured by the fine particle meters 36A and 36B, and the time until the fine particles of 10 μm to 1 mm are detected is measured. Table 2 shows the results.

[Example 3]
Using a batch-type cleaning system shown in FIG. 4, a silicon wafer having a TiN film formed on its surface using sulfuric acid (H ₂ SO ₄ ) as a stock solution of an electrolytic solution was cleaned. The treatment tank 21 is provided with a sulfuric acid supply device for replenishing sulfuric acid and an ultrapure water supply device (not shown), and the concentration and amount of sulfuric acid can be adjusted by control means (not shown).

  After the cleaning of the silicon wafer is continued for about 12 months using the cleaning system 1 as described above, the diamond electrode of the first electrolytic cell 31A is damaged, and the electrolytic solution S flowing through the first liquid supply line 33A is damaged. The fine particles were measured by the fine particle meter 36, and when the fine particles of 10 μm to 1 mm were detected, the line flowing to the fine particle meter 36 was changed as shown in FIG. 5, the broken cell was specified, and the time until the specified was measured. . Table 2 shows the results.

[Comparative Example 1]
As shown in FIG. 8, a silicon wafer having a TiN film formed on the surface thereof using sulfuric acid (H ₂ SO ₄ ) as a stock solution of an electrolytic solution is cleaned using a batch-type cleaning system having no fine particle meter 36 in FIG. went. In FIG. 8, the same components as those in FIG. 4 are denoted by the same reference numerals.

  After the cleaning of the silicon wafer is continued for about 12 months using the cleaning system 1 as described above, the diamond electrode of the first electrolytic cell 31A is damaged, and the diamond electrode is damaged by a leak sensor provided in the first electrolytic cell 31A. Table 2 shows the results of detection of electrode breakage.

  As is clear from Table 2, the cleaning systems of Examples 2 and 3 required only 8 seconds from the breakage of the diamond electrode to detection, whereas Comparative Example 2 detected by the leak sensor required 4 minutes. From these results, in Examples 2 and 3, the operation was stopped within 10 seconds after the electrode was broken and the operation was stopped, and the electrolytic cell could be replaced. In Comparative Example 2, the electrolytic solution S containing fine particles was used. Can be predicted to be supplied to the processing tank 21 to cause a decrease in throughput.

DESCRIPTION OF SYMBOLS 1 Cleaning system 2 Processing apparatus 21 Processing tank 21A Processing chamber 22 Return line 22A First return line 22B Second return line 23 Discharge line 3 Electrolysis reactor 31 Electrolysis cell 31A First electrolysis cell 31B Second electrolysis cell 32 Liquid supply pump 33 Liquid supply line 33A First liquid supply line 33B Second liquid supply line 34 Storage tank 35 Supply valve 35A First supply valve 35B Second supply valve 35C Third supply valve 35D Fourth supply Valve 36 Fine particle meter (fine particle measuring means)
37 Supply line 37A Nozzle 38 Supply pump S Electrolyte T Target member T1 Wafer (target member)

Claims (4)

An electrolytic reaction device having a plurality of electrolytic cells having at least one pair of electrodes having an anode and a cathode, and electrolyzing a solution by an electrolytic reaction,
A treatment device for treating the material to be treated with the electrolytic solution electrolyzed by the electrolytic reaction device,
A liquid sending line that sends an electrolytic solution from the electrolytic reaction device to the processing device,
A return line for returning the electrolytic solution supplied to the processing device to the electrolytic reaction device,
A cleaning system, wherein a particle measuring unit is provided in a liquid sending line between the electrolytic reaction device and the processing device.   The cleaning system according to claim 1, wherein the electrode of the electrolytic cell is a diamond electrode having diamond exposed on the surface.   The cleaning system according to claim 1, wherein the measurement upper limit of the fine particle measurement unit is 10 μm or more.   The cleaning system according to any one of claims 1 to 3, wherein the solution to be electrolyzed includes sulfuric acid, hydrochloric acid, or ammonia.

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