TW201805483A - Device and method for producing and supplying persulfuric acid solution - Google Patents

Abstract

A device and method for producing and supplying a persulfuric acid solution are provided, with which the time taken to replace the persulfuric acid solution in a semiconductor wafer cleaning device is shortened. While a persulfuric acid solution is being circulated and supplied to a cleaning tank 11 by a first electrolysis system 20, water and sulfuric acid are introduced into a storage tank 41 of a second electrolysis system, and circulated through a pump 44, a pipe 45, an electrolysis cell 50, a gas-liquid separator 52, and a pipe 53, to generate persulfuric acid. During the chemical change, the solution is drained from the first electrolysis system 20, and the persulfuric acid solution in storage tank 41 is subsequently transferred to storage tank 22.

Description

Device and method for producing and supplying persulfuric acid solution

The present invention relates to a device and method for supplying a persulfuric acid solution to a cleaning device and the like for cleaning and processing semiconductor crystals.

When the semiconductor wafer is cleaned by an electrolytic sulfuric acid solution, the sulfuric acid is electrolyzed by an electrolytic cell provided with a diamond electrode at least on the anode to generate a peroxymonosulfate containing a predetermined amount of persulfuric acid (peroxymonosulfate ) And peroxydisulfate (a general term for peroxydisulfate), and an electrolytic sulfuric acid composed of a persulfate solution containing no persulfate, and an electrolytic sulfuric acid solution is supplied to the washing machine. This liquid is used to dissolve or clean the resist or metal on the semiconductor wafer.

It takes a long time until electrolytic sulfuric acid is electrolyzed and a predetermined amount of persulfuric acid is generated. Therefore, in order to generate and supply electrolytic sulfuric acid as a cleaning solution in accordance with a wafer cleaning process, it is necessary to install a large number of electrolytic cells.

In Embodiment 5 of Patent Document 1 (Japanese Patent Application Laid-Open No. 2008-111184), the following system has been described: three electrolyte storage tanks are provided, and one is used for discharge to the washing section, and the other is 1 Use For recycling from the washing section, one is used for recycling with the electrolytic tank. When one cycle period is completed, the liquid is switched to recycling → discharge, discharge → recycling → recycling, recycling → The merry-go-round process for recycling uses electrolytic washing as a background to generate electrolytic sulfuric acid. However, since the electrolysis time requires a longer time than the washing time, there is a problem that the waiting time until the production of electrolytic sulfuric acid occurs.

In electrolytic sulfuric acid, for example, SPM (sulfuric acid + hydrogen peroxide) does not reduce the sulfuric acid concentration with the regeneration of persulfuric acid. Therefore, the cleaning liquid can be easily recycled and reused for washing. Accordingly, this method is adopted in the aforementioned Patent Document 1. However, the impurities contained in the cleaning liquid (except for a trace amount of metal eluted from the wafer) are organic matter or SS originating from organic matter when the resist is stripped and removed, and remain as a residue when the residual metal is dissolved and removed. Metal residues) are mixed into the liquid as the number of cycles increases. For this reason, there is a risk that the electrolytic treatment or the washing treatment will be adversely affected with the passage of time.

For this reason, it is necessary to exchange the washing | cleaning liquid into a fresh washing | cleaning liquid regularly in the circulation type especially. Specifically, the following steps are required: periodically extruding all the liquid in the system, or periodically or continuously extruding a part, and supplying sulfuric acid in this part to generate electrolytic sulfuric acid and restarting wafer cleaning. . However, in the above-mentioned prior art, solution exchange is not considered.

In a carousel system such as Japanese Patent Application Laid-Open No. 2008-111184, all storage tanks must be formed to the same size. for Here, the system is enlarged, for example, as the first storage tank 100L, the second storage tank 100L, the third storage tank 100L, the cleaning tank capacity 60L, and the piping capacity 10L.

As described above, in the case where the semiconductor wafer is cleaned by electrolytic sulfuric acid, the cleaning and drainage liquid is recycled, and the solution is considered by accumulating the accumulation of impurities contained in the cleaning and drainage liquid over time. However, since it takes a long time to electrolyze sulfuric acid to generate persulfuric acid, the wafer cannot be processed until the electrolyzed and generated amount of persulfuric acid is generated.

[Prior technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 2008-111184

An object of the present invention is to provide a persulfuric acid solution manufacturing and supplying device and method capable of shortening the exchange time of persulfuric acid solution in a semiconductor wafer cleaning device.

The persulfuric acid solution manufacturing and supplying device of the present invention includes a first electrolytic system that cyclically supplies a persulfuric acid solution to a wafer cleaning device. The persulfuric acid solution manufacturing and supplying device includes a second electrolytic system for generating a persulfuric acid solution, which is provided separately from the first electrolytic system; and The transfer device transfers the electrolytic solution from the second electrolytic system to the first electrolytic system.

The persulfuric acid solution production and supply method of the present invention supplies a persulfuric acid solution to a wafer cleaning apparatus using the persulfuric acid solution production and supply apparatus of the present invention. In this method, in at least a part of the step of cleaning the wafer by the wafer cleaning device, electrolytic treatment is performed with a second electrolytic system to generate a persulfuric acid solution; the wafer cleaning device and the first When the persulfuric acid solution of the 1 electrolytic system is exchanged, after the persulfuric acid solution is discharged from the wafer cleaning device and the first electrolytic system, the persulfuric acid solution is transferred from the second electrolytic system to the second electrolytic system.

In one aspect of the present invention, the first electrolytic system includes: a first storage tank that stores a persulfuric acid solution that is circulated and supplied to a wafer cleaning device; and a first electrolytic tank that is an electrolytic treatment unit. The liquid supplied from the first storage tank, and the liquid after the electrolytic treatment is returned to the first storage tank; the second electrolysis system includes: a second storage tank; and a second electrolytic tank And a device for supplying the liquid supplied from the second storage tank and returning the electrolytically processed liquid to the second storage tank; and supplying sulfuric acid and water to the second storage tank.

The present invention provides a second electrolytic system for producing electrolytic sulfuric acid in advance and storing it in a preliminary tank in a persulfuric acid solution manufacturing and supplying device having a first electrolytic system for supplying and returning electrolytic sulfuric acid to a semiconductor wafer cleaning device.

In the apparatus and method of the present invention, since the second electrolytic system can be used to generate and store electrolytic sulfuric acid during wafer cleaning, the waiting time (chemical change time) for wafer cleaning can be shortened . Since the liquid does not flow from the first electrolytic system to the second electrolytic system, there is no possibility that impurities may be mixed into and accumulated in the second electrolytic system.

10‧‧‧batch washing machine

11‧‧‧washing tank

12, 14, 16, 17, 21, 23, 25, 28, 31, 33, 42, 43, 45, 47, 49, 53, 54, 54, 65, 69, 73, 75

13, 24, 27, 44, 64, 67, 71‧‧‧ pump

15‧‧‧ heater

18, 46, 48, 74, 77‧‧‧ valves

20、80‧‧‧The first electrolytic system

22‧‧‧ storage tank (first storage tank)

30‧‧‧ electrolytic cell (first electrolytic cell)

32‧‧‧Gas-liquid separator

40‧‧‧Second electrolytic system

41‧‧‧ storage tank (second storage tank)

50‧‧‧ electrolytic cell (second electrolytic cell)

56‧‧‧Gas treatment plant

60‧‧‧washing device

61‧‧‧washing liquid nozzle

62‧‧‧Turntable

63‧‧‧Recovery tank

66, 70‧‧‧ storage tank

68‧‧‧Heat exchanger

73‧‧‧Fast heater

76‧‧‧Piping (Bypass)

100‧‧‧Semiconductor wafer

Fig. 1 is a block diagram showing an embodiment.

Fig. 2 is a block diagram showing the persulfuric acid solution manufacturing and supplying apparatus of Fig. 1;

Fig. 3 is a block diagram showing another embodiment.

Fig. 4 is a block diagram showing the persulfuric acid solution production and supply device of Fig. 3.

The persulfuric acid solution production and supply device according to the first embodiment of the present invention will be described based on Fig. 1.

This persulfuric acid solution manufacturing and supplying apparatus includes a batch-type cleaning machine 10 that cleans a plurality of semiconductor wafers 100 in a concentrated manner, and a first electrolytic system 20 and a second electrolytic system 40. The electrolytic cells 30 and 50 of the electrolytic systems 20 and 40 each have an electrode using at least the anode as a diamond electrode, and are provided with a power source device for energizing between the anode and the cathode. (Not shown). A bipolar electrode may be provided as an electrode.

The batch-type cleaning machine 10 has a high-temperature rinsing tank for washing semiconductor wafers 100 washed in the cleaning tank 11 in addition to a cleaning tank 11 that can be filled with sulfuric acid solution after electrolysis, and further rinses in A normal-temperature rinsing tank of the semiconductor wafer 100 washed by the high-temperature rinsing tank, and a dryer (not shown) that dries the semiconductor wafer 100 after being washed in the normal-temperature washing tank.

The liquid outflow portion and the liquid inlet portion of the washing tank 11 are connected by a circulation pipe constituted by a pipe 12, a pump 13, a pipe 14, a heater 15, and a pipe 16. Each of the pipes and equipment is made of a material having heat resistance to a temperature of 100 ° C or higher, and is made of, for example, a fluororesin such as PFA.

From the piping 16, a piping 17 having a valve 18 is branched, and the liquid inside the system can be discharged to the outside of the system.

The first electrolysis system 20 includes a storage tank (first storage tank) 22 which can introduce the washing machine discharge liquid through a pipe 21 branched from the pipe 12; and the above-mentioned electrolytic tank 30 and the like, which are electrolysis The liquid in the storage tank 22 is processed; and the piping 23, the pump 24, the piping 25, and the like are used to return the electrolytically processed liquid to the piping 16.

The liquid in the storage tank 22 is introduced into the electrolytic tank 30 (the first electrolytic tank) through a pump 27 and a pipe 28. The liquid after the electrolytic treatment is returned to the storage tank 22 through the pipe 31, the gas-liquid separator 32, and the pipe 33. The gas separated in the gas-liquid separator 32 is sent to the gas processing 装置 56。 Device 56.

The second electrolysis system 40 is provided with a storage tank (second storage tank) 41 which is supplied with sulfuric acid and water from pipes 42 and 43, respectively, and a pump 44, a pipe 45, and a valve 46 which are used for The liquid in the storage tank 41 is supplied to the electrolytic tank (second electrolytic tank) 50; the gas-liquid separator 52 is a liquid that is electrolyzed by the electrolytic tank 50 is introduced through a pipe 51; and the pipe 53 is a gas-liquid separator 52 The liquid is returned to the storage tank 41 and a pipe 54 for sending the gas separated by the gas-liquid separator 52 to the gas processing device 56.

The piping 47 is branched from the piping 45, and the liquid in the storage tank 41 can be supplied to the storage tank 22 of the first electrolysis system through the piping 45, 47, the valve 48, and the piping 49.

Next, the operation of the persulfuric acid solution production and supply device will be described with reference to FIG. 2.

The washing tank 11 is filled with a sulfuric acid solution having a sulfuric acid concentration of 70% to 96% by mass. Part of the liquid flowing from the washing tank 11 to the piping 12 is circulated through the pump 13, the piping 14, the heater 15, and the piping 16. For example, the sulfuric acid solution is circulated at a circulation flow rate of 1/2 V / min to 1/3 V / min with respect to the tank volume V of the cleaning tank 11. At this time, the valve 18 is closed.

The remainder of the liquid flowing out to the piping 12 is introduced into the storage tank 22 through the piping 21. A part of the liquid introduced into the storage tank 22 is circulated to the storage tank 22 through the pump 27, piping 28, electrolytic tank 30, piping 31, gas-liquid separator 32, and piping 33, thereby performing Electrolytically processes and produces persulfuric acid. The liquid in the storage tank 22 containing persulfuric acid is supplied to the pipe 16 through the pipe 23, the pump 24, and the pipe 25.

In this way, during the wafer cleaning, particularly at least in the initial stage of the wafer cleaning process, water and sulfuric acid can be introduced into the storage tank 41 of the second electrolytic system, and a part of the liquid inside the storage tank 41 is transmitted through the pump. 44. The piping 45, the electrolytic tank 50, the gas-liquid separator 52, and the piping 53 are circulated to perform electrolytic treatment and generate persulfuric acid. At this time, the valve 46 is opened and the valve 48 is closed. If the persulfuric acid concentration in the storage tank 41 has reached a predetermined concentration, the cycle is stopped, and the persulfuric acid solution is stored in the storage tank 41 in advance.

After a predetermined time or a predetermined number of wafers have been cleaned, the valve 18 is opened, and the liquid in the cleaning tank 11 and the pipes 12, 14, 16, 21, 23, 25, and the first electrolytic system 20 is passed through the pipes. 17 and discharged to the outside of the system.

Next, after the valve 18 is closed, the fresh persulfuric acid solution previously stored in the storage tank 41 is introduced into the storage tank 22 through the pump 44 and the pipes 45, 47, and 49. At this time, the valve 46 is closed and the valve 48 is opened.

After the predetermined amount of the persulfuric acid solution is transferred to the storage tank 22, the transfer is stopped, the liquid in the tank 22 is supplied to the washing tank 11 through the pump 24, the pipes 23, and 25, and the washing is filled with the persulfuric acid solution. After the circulation lines of the cleaning tank 11, the pipes 12, 14, and 16, the wafer cleaning is started again.

In this way, as shown in FIG. 2, while the wafer 100 is cleaned in the cleaning tank 11, since the persulfuric acid solution has been produced in the second electrolytic system 40, the wafers can be cleaned and processed in one batch. During the next batch of wafer cleaning, only the liquid from the cleaning tank 11 and the first electrolytic system 20 is discharged, and the persulfuric acid is transferred from the second electrolytic system 40 to the cleaning tank 11 and the first electrolytic system 20 Solution to start the cleaning of the next batch, and can significantly reduce the persulfuric acid solution renewal operation (chemical change) time between batches.

In the present invention, the capacity of the storage tank 22 of the first electrolytic system 20 can be reduced. When the second electrolytic system 40 is not provided, for example, the cleaning tank capacity is 60L, and when the required amount of persulfuric acid solution for one batch is 100L, the storage tank 22 capacity is 100L, the cleaning tank capacity is 60L, and the piping capacity is 10L On the other hand, when the second electrolytic system 40 is provided, the storage tank 41 has a capacity of 100 L, the storage tank 22 has a capacity of 30 L, the cleaning tank capacity is 60 L, and the piping capacity is about 10 L. Since the capacity of the storage tank 22 can be halved, it is possible to suppress an increase in the size of the device caused by the addition of the second electrolytic system 40.

Generally, the capacity of the storage tank 22 of the first electrolytic system 20 is 10L to 80L, and the capacity of the storage tank 41 of the second electrolytic system 40 is about 80L to 150L.

Although FIG. 1 and FIG. 2 show a batch-type washing device, the present invention can also be applied to the single-chip washing device 60 shown in FIGS. 3 and 4.

The single-piece cleaning device 60 includes: The mouth 61 is for turning the wafer 100 to be carried in, and the rotary table 62 is for placing and rotating the wafer 100. The cleaning solution nozzle 61 is used to spray a sulfuric acid solution as a cleaning solution or to flow down a small amount at a time to supply to the upper surface of the wafer 100 held by the turntable.

The cleaning liquid supplied to the upper surface of the wafer 100 is subjected to centrifugal force caused by the rotation of the wafer 100 and spreads toward the peripheral portion on the upper surface of the wafer 100 to thereby clean the wafer 100. The cleaning liquid is thrown away from the periphery of the wafer 100 and scattered toward the side, and is introduced into the recovery tank 63 and then introduced into the storage tank 66 through the pump 64 and the pipe 65. The liquid in the storage tank 66 is introduced into the storage tank 70 through the pump 67, the heat exchanger 68, and the piping 69. The liquid in the storage tank 70 is supplied to the washing liquid nozzle 61 through the pump 71, the rapid heater 72, the piping 73, the valve 74, and the piping 75. A pipe (bypass line 76) is branched from the pipe 73, and a valve 77 is provided in the pipe 76. When the wafer is cleaned by the cleaning device 60, the valve 74 is opened and the valve 77 is closed. When the wafer cleaning of the cleaning device 60 is stopped, the valve 74 is closed, the valve 77 is opened, and the liquid from the pipe 73 is supplied through the pipe 76 to the storage tank 66. The rapid heater 72 is, for example, near The infrared heater rapidly heats the sulfuric acid solution to 120 ° C to 220 ° C in a transient manner.

The first electrolytic system 80 includes: the storage tank 70; and the above-mentioned electrolytic tank 30 for electrolytically processing the liquid in the storage tank 70. The configuration of the electrolytic cell 30 and the circulation supply mechanism for circulating the liquid to the electrolytic cell 30 is the same as in the case of FIGS. 1 and 2. That is, the liquid in the storage tank 70 is introduced into the electrolytic tank through the pump 27 and the piping 28 30. The liquid after the electrolytic treatment can be returned to the storage tank 70 through the pipe 31, the gas-liquid separator 32, and the pipe 33. The gas separated by the gas-liquid separator 32 is sent to a gas processing device 56.

The configuration of the second electrolytic system 40 is the same as that of the first and second figures, and the same reference numerals are attached to the same members, and descriptions thereof are omitted.

Even in this single-chip cleaning apparatus, as shown in FIG. 4, during the wafer cleaning by the cleaning apparatus 60, particularly at least in the initial stage of the wafer cleaning process, the first 2 Water and sulfuric acid are introduced into the storage tank 41 of the electrolytic system, and a part of the liquid in the storage tank 41 is circulated through the pump 44, the piping 45, the electrolytic tank 50, the gas-liquid separator 52, and the piping 53 to perform electrolytic treatment and Persulfuric acid is formed. At this time, the valve 46 is opened and the valve 48 is closed. If the persulfuric acid concentration in the storage tank 41 has reached a predetermined concentration, the cycle is stopped, and the persulfuric acid solution is stored in the storage tank 41 in advance.

After a predetermined time or a predetermined number of wafers have been cleaned, the liquid in the cleaning device 60, the recovery tank 63, the storage tank 66, and the pipes 65, 69, 73, 75, and the first electrolytic system 20 is collected and recovered. The tank 63 or a drain line (not shown) connected to the upstream side of the recovery tank 63 is discharged to the outside of the system.

Next, the fresh persulfuric acid solution previously stored in the storage tank 41 is introduced into the storage tank 70 through the pump 44 and the pipes 47 and 49. At this time, the valve 46 is closed and the valve 48 is opened.

After the predetermined amount of the persulfuric acid solution is transferred to the storage tank 70, the transfer is stopped, and the liquid in the storage tank 70 is passed through the pump 71, The tubes 73 and 75 are supplied to the cleaning device 60, and the wafer cleaning is started again.

As described above, since the persulfuric acid solution has been produced in the second electrolytic system 40 while the wafer 100 is being cleaned by the cleaning device 60, when the persulfuric acid solution renewal operation is performed, it is only necessary to perform the operation from the first electrolytic system 80. It is only necessary to discharge the liquid and transfer the persulfuric acid solution from the second electrolytic system 40 to the same, and it is possible to significantly shorten the time for regenerating the persulfuric acid solution (chemical change).

The present invention can be suitably used particularly when the oxidant concentration of the persulfuric acid solution is high (for example, 0.03 mol / L to 0.1 mol / L), or when the temperature of the cleaning solution is high (for example, 150 ° C to 180 ° C).

[Example]

Examples and comparative examples of the present invention are shown below.

[Comparative Example 1]

In the first figure, the second electrolytic system 40 has been omitted. The first electrolytic system 20 is provided with four electrolytic cells 30. With this device, a chemical change was performed. The existing solution was discharged from the pipe 17, and new sulfuric acid and water were put into the washing tank 11 and the storage tank 22 so that the sulfuric acid concentration became 85%. The temperature of the solution in the washing tank 11 was set at 120 ° C. Thereafter, the electrolytic cell 30 was energized at a current density of 0.4 A / cm ² to generate an electrolytic sulfuric acid solution, and the concentration of the oxidant was set to 0.01 mol / L to complete the chemical change.

The time it takes to complete the chemical change is 300 minute. During the subsequent wafer cleaning process (12 hours), the oxidant concentration of the electrolytic sulfuric acid solution was stable.

[Comparative Example 2]

In Comparative Example 1, it was the same except that the number of electrolytic cells 30 was set to 10. With this device, a chemical change was performed. The existing solution was discharged, and new sulfuric acid and water were put into the washing tank 11 and the storage tank 22 so that the sulfuric acid concentration became 85%. The temperature of the solution in the washing tank 11 was set at 120 ° C. Thereafter, the electrolytic cell 30 was energized at a current density of 0.4 A / cm ² to generate an electrolytic sulfuric acid solution, and the oxidant concentration was set to 0.03 mol / L to complete the chemical change.

The time taken until the chemical change was completed was 300 minutes. During the subsequent wafer cleaning process (12 hours), the oxidant concentration of the electrolytic sulfuric acid solution was stable.

[Comparative Example 3]

In Comparative Example 1, it was the same except that the number of electrolytic cells 30 was set to 15. With this device, a chemical change was performed. The existing solution was discharged, and new sulfuric acid and water were put into the washing tank 11 and the storage tank 22 so that the sulfuric acid concentration became 85%. The temperature of the solution in the washing tank 11 was set at 150 ° C. Thereafter, the electrolytic cell 30 was energized at a current density of 0.4 A / cm ² to generate an electrolytic sulfuric acid solution, and the concentration of the oxidant was set to 0.01 mol / L to complete the chemical change.

The time it takes to complete the chemical change is 300 minute. During the subsequent wafer cleaning process (12 hours), the oxidant concentration of the electrolytic sulfuric acid solution was stable.

[Example 1]

As shown in FIG. 1, a second electrolytic system 40 is provided. The number of electrolytic cells 30 in the first electrolytic system is four, and the number of electrolytic cells 50 in the second electrolytic system is two. With this apparatus, during the wafer processing, the second electrolytic system 40 is used to put new sulfuric acid and water into the storage tank 41 so that the sulfuric acid concentration becomes 85%. The electrolytic cells 30 and 50 were energized at a current density of 0.4 A / cm ² to generate an electrolytic sulfuric acid solution, and the oxidant concentration was set to 0.01 mol / L. When a chemical change is performed, first, the electrolytic sulfuric acid solution of the washing tank 11 and the pipes 12 to 16 and the first electrolytic system 20 is discharged, and the electrolytic sulfuric acid solution manufactured in the second electrolytic system 40 is removed from the storage tank 41 transferring to storage tank 22. The temperature of the solution in the washing tank 11 was set at 120 ° C. Accordingly, the chemical change time (the time during which wafer processing cannot be performed) is 60 minutes. During the subsequent wafer cleaning process (12 hours), the oxidant concentration of the electrolytic sulfuric acid solution was stable.

[Example 2]

In Example 1, it is the same except that six electrolytic cells 30 of the first electrolytic system are provided, and three electrolytic cells 50 of the second electrolytic system are provided. With this apparatus, during the wafer cleaning process, the second electrolytic system 40 is used to put new sulfuric acid and water into the storage tank 41 so that the sulfuric acid concentration becomes 85%. Thereafter, the electrolytic cells 30 and 50 were energized at a current density of 0.4 A / cm ² to produce an electrolytic sulfuric acid solution, and the oxidant concentration was set to 0.03 mol / L. The chemical change was performed in the same manner as in Example 1. The temperature of the solution in the washing tank 11 was set at 120 ° C. Accordingly, the chemical change time (the time during which wafer processing cannot be performed) is 60 minutes. During the subsequent wafer cleaning process (12 hours), the oxidant concentration of the electrolytic sulfuric acid solution was stable.

[Example 3]

In Example 1, it is the same except that eight electrolytic cells 30 of the first electrolytic system are provided, and two electrolytic cells 50 of the second electrolytic system are provided. With this device, during the wafer cleaning process, it is put into the storage tank 41 so that the sulfuric acid concentration becomes 85%. The electrolytic cells 30 and 50 were energized at a current density of 0.4 A / cm ² to generate an electrolytic sulfuric acid solution, and the oxidant concentration was set to 0.01 mol / L. The chemical change was performed in the same manner as in Example 1. The temperature of the solution in the washing tank 11 was set at 150 ° C. Accordingly, the chemical change time (the time during which wafer processing cannot be performed) is 60 minutes. During the subsequent wafer cleaning process (12 hours), the oxidant concentration of the electrolytic sulfuric acid solution was stable.

The results of Comparative Examples and Examples are shown in Table 1.

In Comparative Examples 1 to 3, although it took a long time to replace the circulating liquid in the cleaning liquid circulation pipe from the electrolytic sulfuric acid generating section of the first electrolytic system with fresh electrolytic sulfuric acid, in Examples 1 to 3, The time required for liquid exchange can be greatly reduced.

As in Comparative Example 2, although the set concentration of the oxidant concentration in electrolytic sulfuric acid is high, it is necessary to consider the disappearance of persulfuric acid and increase the number of electrolytic cells in the electrolytic sulfuric acid device. As in Example 2, it has been confirmed that the increase in the number of electrolytic cells can be suppressed.

As in Comparative Example 3, when the temperature in the cleaning tank 11 is high, it is necessary to consider the disappearance of persulfuric acid and increase the number of electrolytic cells in the electrolytic sulfuric acid device. However, in the present invention, it is the same as Example 3. In general, it has been confirmed that an increase in the number of electrolytic cells can be suppressed.

Although the present invention has been described in detail using specific aspects, it will be apparent to those skilled in the art to which the present invention pertains that various changes can be made without departing from the spirit and scope of the present invention.

This application is based on Japanese Patent Application No. 2016-061470 filed on March 25, 2016, and its entirety can be incorporated by reference.

10‧‧‧batch washing machine

11‧‧‧washing tank

12, 14, 16, 17, 21, 23, 25, 28, 31, 33, 42, 43, 45, 47, 49, 53, 54

13, 24, 27, 44‧‧‧ pump

15‧‧‧ heater

18, 46, 48‧‧‧ valve

20‧‧‧The first electrolytic system

22‧‧‧ storage tank (first storage tank)

30‧‧‧ electrolytic cell (first electrolytic cell)

32‧‧‧Gas-liquid separator

40‧‧‧Second electrolytic system

41‧‧‧ storage tank (second storage tank)

50‧‧‧ electrolytic cell (second electrolytic cell)

52‧‧‧Gas-liquid separator

56‧‧‧Gas treatment plant

100‧‧‧Semiconductor wafer

Claims (3)

A persulfuric acid solution manufacturing and supplying device includes a first electrolytic system for circulatingly supplying a persulfuric acid solution to a wafer cleaning device, and is characterized by including a second electrolyzing system for generating a persulfuric acid solution. The electrolytic system is provided separately; and a transfer device that transfers an electrolytic solution from the second electrolytic system to the first electrolytic system. The persulfuric acid solution manufacturing and supply device according to claim 1, wherein the first electrolytic system includes: a first storage tank that stores a persulfuric acid solution that is circulated and supplied to the wafer cleaning device; and a first electrolytic tank, It is an electrolytic treatment of the liquid supplied from the first storage tank, and returns the liquid after the electrolytic treatment to the first storage tank; a second electrolytic system includes: a second storage tank; and a second electrolytic tank, This is an apparatus for electrolytically processing the liquid supplied from the second storage tank and returning the electrolytically processed liquid to the second storage tank; and supplying sulfuric acid and water to the second storage tank. A method for manufacturing and supplying a persulfuric acid solution is to supply a persulfuric acid solution to a wafer cleaning device by using the persulfuric acid solution production and supply device according to claim 1 or 2; In at least a part of the round process, the second electrolytic system is used for electrolytic treatment to generate a persulfuric acid solution. When the wafer cleaning device and the first electrolytic system are exchanged with the persulfuric acid solution, the wafer cleaning device And the first electrolytic system After the acid solution, the persulfuric acid solution is transferred from the second electrolysis system to the second electrolysis system.