JP2012080048A - Substrate processing apparatus, substrate processing method, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the bumping in a supply tank and an evaporation tank of a sulfuric acid-regenerating unit of a substrate processing apparatus.SOLUTION: The substrate processing apparatus has: a substrate-processing part 60 for processing a substrate W to be processed using sulfuric acid; and a sulfuric acid-regenerating unit 1 for regenerating waste sulfuric acid consisting of the sulfuric acid used in the substrate-processing part 60. The sulfuric acid-regenerating unit 1 includes: evaporation tanks 15a and 15b for storing the waste sulfuric acid; a heating parts 17a and 17b for heating the waste sulfuric acid in the evaporation tanks 15a and 15b; a supply tank 10 for supplying the waste sulfuric acid to the evaporation tanks 15a and 15b; supply pipes 12a and 12b for connecting between the supply tank 10 and the evaporation tanks 15a and 15b; and flow-rate regulators 13a and 13b for regulating the amount of the waste sulfuric acid supplied from the supply tank 10 to the evaporation tanks 15a and 15b. As to the evaporation tanks 15a and 15b, a first pressure-reducing part 24 for reducing the pressures inside the evaporation tanks 15a and 15b is provided. The supply tank 10 is provided with a pressure regulator 11 for making the pressure inside the supply tank 10 higher than the pressures inside the evaporation tanks 15a and 15b.

Description

  The present invention relates to a substrate processing apparatus and a substrate processing method provided with a sulfuric acid regenerating apparatus for regenerating waste sulfuric acid, and a storage medium storing a computer program for causing the substrate processing apparatus to execute the substrate processing method.

  2. Description of the Related Art Conventionally, a sulfuric acid regenerating apparatus including a distillation tank that stores waste sulfuric acid and a heating unit that heats waste sulfuric acid stored in the distillation tank is known (see, for example, Patent Document 1). However, when waste sulfuric acid is regenerated at a time in one evaporation tank, hydrogen peroxide contained in the waste sulfuric acid is decomposed, and the liquid surface may be shaken to cause bumping.

Japanese Patent Laid-Open No. 08-091811

  The present disclosure relates to a substrate processing apparatus and a substrate processing method capable of preventing bumping in a supply tank and an evaporation tank in a sulfuric acid regeneration apparatus of a substrate processing apparatus, and a computer for causing the substrate processing apparatus to execute the substrate processing method A storage medium storing a program is provided.

A substrate processing apparatus according to the present disclosure includes:
A substrate processing unit for processing a substrate to be processed using sulfuric acid;
A sulfuric acid regenerating apparatus for regenerating waste sulfuric acid used in the substrate processing unit,
The sulfuric acid regenerator is
An evaporation tank containing the waste sulfuric acid;
A heating unit for heating the waste sulfuric acid accommodated in the evaporation tank;
A supply tank for containing the waste sulfuric acid and supplying the waste sulfuric acid to the evaporation tank;
A supply pipe connecting the supply tank and the evaporation tank;
A flow rate adjusting unit for adjusting an amount of the waste sulfuric acid provided in the supply pipe and supplied from the supply tank to the evaporation tank;
A first pressure reducing unit provided in the evaporation tank, for reducing the pressure in the evaporation tank;
A pressure adjusting unit that is provided in the supply tank and makes the pressure in the supply tank higher than the pressure in the evaporation tank.

In the substrate processing apparatus according to the present disclosure,
When the waste sulfuric acid is supplied from the supply tank to the evaporation tank, a gas flow between the supply tank and the evaporation tank may be blocked by the waste sulfuric acid.

In the substrate processing apparatus according to the present disclosure,
The pressure adjusting unit may be a pressure adjusting pipe provided in the supply tank and connected to the outside.

In the substrate processing apparatus according to the present disclosure,
The pressure adjusting unit may be a pressurizing unit that increases the pressure in the supply tank.

A substrate processing apparatus according to the present disclosure includes:
A product receiving tank connected to the evaporation tank and receiving sulfuric acid concentrated in the evaporation tank;
A second decompression unit connected to the product receiving tank and decompressing the inside of the product receiving tank may further be provided.

In the substrate processing apparatus according to the present disclosure,
When the concentrated sulfuric acid is transferred from the evaporation tank to the product receiving tank, the inside of the product receiving tank may be depressurized by the second decompression unit.

A substrate processing apparatus according to the present disclosure includes:
A plurality of product receiving tanks connected to the evaporation tank and receiving sulfuric acid concentrated in the evaporation tank;
A second decompression unit connected to each of the product receiving tanks and for depressurizing the inside of the product receiving tanks,
When the concentrated sulfuric acid is transferred from the evaporation tank to at least one of the product receiving tanks, the inside of the product receiving tank to which the concentrated sulfuric acid is transferred is depressurized and concentrated by the second pressure reducing unit. The inside of the product receiving tank where the sulfuric acid is not transferred does not have to be depressurized.

In the substrate processing apparatus according to the present disclosure,
A flow rate adjusting unit for adjusting the amount of the waste sulfuric acid supplied from the supply tank to the evaporation tank may be provided between the supply tank and the evaporation tank.

In the substrate processing apparatus according to the present disclosure,
The substrate processing unit processes the substrate to be processed using waste sulfuric acid containing hydrogen peroxide,
A deaeration unit for decomposing and removing the hydrogen peroxide contained in the waste sulfuric acid is connected to the substrate processing unit,
The supply tank may contain waste sulfuric acid from which the hydrogen peroxide has been removed in the deaeration unit.

In the substrate processing apparatus according to the present disclosure,
The substrate processing unit processes the substrate to be processed using waste sulfuric acid containing hydrogen peroxide,
A deaeration unit for decomposing and removing the hydrogen peroxide contained in the waste sulfuric acid is connected to the substrate processing unit,
The deaeration unit includes a deaeration tank that stores the waste sulfuric acid containing the hydrogen peroxide, and a heating unit that heats the waste sulfuric acid containing the hydrogen peroxide,
The supply tank may be the deaeration tank.

A substrate processing method according to the present disclosure includes:
Treating the substrate to be treated with a treatment solution containing sulfuric acid;
Regenerating the waste sulfuric acid used in the substrate processing unit,
Recycling waste sulfuric acid
Supplying waste sulfuric acid from the supply tank to the evaporation tank;
Heating the waste sulfuric acid accommodated in the evaporation tank under reduced pressure,
When supplying the waste sulfuric acid from the supply tank to the evaporation tank, the flow rate of the waste sulfuric acid is adjusted, and the pressure in the supply tank is higher than the pressure in the evaporation tank.

In the substrate processing method according to the present disclosure,
When supplying the waste sulfuric acid from the supply tank to the evaporation tank, a gas flow between the supply tank and the evaporation tank may be blocked by the waste sulfuric acid.

A storage medium according to the present disclosure includes:
A storage medium storing a computer program for causing a substrate processing apparatus to execute a substrate processing method,
The substrate processing method comprises:
Treating the substrate to be treated with a treatment solution containing sulfuric acid;
Regenerating the waste sulfuric acid used in the substrate processing unit,
Recycling waste sulfuric acid
Supplying waste sulfuric acid from the supply tank to the evaporation tank;
Heating the waste sulfuric acid accommodated in the evaporation tank under reduced pressure,
When supplying the waste sulfuric acid from the supply tank to the evaporation tank, the flow rate of the waste sulfuric acid is adjusted, and the pressure in the supply tank is higher than the pressure in the evaporation tank. .

  According to the present invention, since the flow rate adjusting unit is provided in the supply pipe that connects the supply tank and the evaporation tank, the waste sulfuric acid is supplied to the evaporation tank little by little. For this reason, bumping can be prevented from occurring in the evaporation tank. Moreover, since the pressure adjustment part which makes the pressure in a supply tank higher than the pressure in an evaporation tank is provided, bumping in a supply tank can be prevented. Furthermore, since the pressure in the evaporation tank is reduced, the water in the waste sulfuric acid can be evaporated at a lower temperature than that under normal pressure, and the waste sulfuric acid can be concentrated efficiently.

The figure which shows the structure of the substrate processing apparatus by the 1st Embodiment of this invention. The enlarged view which shows a part of structure of the substrate processing apparatus by the modification of the 1st Embodiment of this invention. The figure for demonstrating the flow of the signal in the substrate processing apparatus by the 1st Embodiment of this invention. The figure which shows the structure of the substrate processing apparatus by the 2nd Embodiment of this invention. The enlarged view which shows a part of structure of the substrate processing apparatus by the modification of the 2nd Embodiment of this invention.

First Embodiment Hereinafter, a first embodiment of a sulfuric acid regenerating apparatus according to the present invention will be described with reference to the drawings. Here, FIG. 1 to FIG. 3 are diagrams showing a first embodiment of the present invention.

  As shown in FIG. 1, the sulfuric acid regenerator 1 includes evaporation tanks 15a and 15b for storing waste sulfuric acid, and heating units 17a and 17b for heating the waste sulfuric acid stored in the evaporation tanks 15a and 15b. The evaporation unit 5 is provided. The sulfuric acid regenerating apparatus 1 also includes a supply tank 10 that supplies waste sulfuric acid to the evaporation tanks 15 a and 15 b, and supply pipes 12 a and 12 b that are disposed between the evaporation tanks 15 a and 15 b and the supply tank 10. In addition, in this Embodiment, although demonstrated using the aspect with which two evaporation tanks are provided, it is an example to the last, and there may be only one evaporation tank, and three or more are provided. It may be.

  As shown in FIG. 1, a vacuum pump 24, which is a first pressure reducing unit for reducing the pressure in the evaporation tanks 15 a and 15 b, is connected to the evaporation tanks 15 a and 15 b through an exhaust pipe 18. The exhaust pipe 18 is provided with a heat exchanger 16 that cools the water vapor evaporated from the evaporation tanks 15a and 15b and converts it into water. The water generated by the heat exchanger 16 is discharged to the outside through the drain pipe 19.

  The supply tank 10 is connected to the outside, and is provided with a pressure adjusting pipe 11 that makes the pressure in the supply tank 10 substantially equal to the outside. In the present embodiment, the pressure adjusting pipe 11 constitutes a pressure adjusting unit that makes the pressure in the supply tank 10 higher than the pressure in the evaporation tanks 15a and 15b. By the way, the pressure adjusting unit is not limited to such a pressure adjusting tube 11, and a pressurizing unit 11 ′ for increasing the pressure in the supply tank 10 as shown in FIG. 2 can also be used.

  As shown in FIG. 1, the supply pipes 12a and 12b are provided with open / close valves 14a and 14b for switching the supply pipes 12a and 12b, and an orifice 13a provided on the downstream side of the open / close valves 14a and 14b. , 13b are provided. The orifices 13a and 13b constitute a flow rate adjusting unit that adjusts the amount of waste sulfuric acid supplied from the supply tank 10 to the evaporation tanks 15a and 15b. By the way, as the orifices 13a and 13b, a fixed orifice whose opening degree is fixed, a variable orifice whose air opening degree can be changed, an air operation valve, or the like can be used. Even when fixed orifices are used as the orifices 13a and 13b, the waste supplied to the evaporation tanks 15a and 15b can be maintained by maintaining a constant pressure difference between the supply tank 10 and the evaporation tanks 15a and 15b. The amount of sulfuric acid can be made constant.

  The evaporating tanks 15a and 15b receive a concentrated sulfuric acid (hereinafter also referred to as “concentrated sulfuric acid”) after the water is evaporated through the supply pipe 21 provided with the opening and closing valves 22a and 22b. A plurality (two in the present embodiment) of product tanks 20a and 20b, which are receiving tanks, are provided. Each of the product tanks 20a and 20b is provided with the vacuum pump 24 via an exhaust pipe 28 provided with opening and closing valves 27a and 27b. When the concentrated sulfuric acid is transferred from the evaporation tanks 15a and 15b to one of the product tanks 20a and 20b (for example, the product tank 20a), the open / close valve 27a is opened and the product tank to which the concentrated sulfuric acid is supplied. The interior of 20a is configured to be depressurized by a vacuum pump 24. On the other hand, when the concentrated sulfuric acid is transferred to the product tank 20a in this way, the open / close valve 27b is closed and the inside of the product tank 20b is not depressurized by the vacuum pump 24. By the way, each of the product tanks 20a and 20b is provided with leak valves 25a and 25b for returning the product tanks 20a and 20b to normal pressure.

  In the present embodiment, the first vacuum part for reducing the pressure in the evaporation tanks 15 a and 15 b and the second pressure reducing part for reducing the pressure in the product tanks (product receiving tanks) 20 a and 20 b are provided from the same vacuum pump 24. However, the present invention is not limited to this, and the first decompression unit and the second decompression unit may be composed of separate vacuum pumps, for example.

  In addition, the supply tank 10 is provided with an opening / closing valve 77 that includes a degassing unit 70 that decomposes and removes hydrogen peroxide by heating used sulfuric acid / hydrogen peroxide (waste sulfuric acid containing hydrogen peroxide). Are connected via a connecting pipe 79. The deaeration unit 70 includes a deaeration tank 71 for storing used sulfuric acid / hydrogen peroxide, a circulation pipe 78 for circulating the used sulfuric acid / hydrogen peroxide in the degassing tank 71, and a circulation pipe 78. A drive unit 73 such as a pump that provides drive power to the used sulfuric acid superwater that is provided and accommodated in the deaeration tank 71, and a heating unit 72 that heats the used sulfuric acid hydrogen peroxide circulated in the circulation pipe, ,have. The deaeration unit 70 is necessary only when the waste sulfuric acid contains hydrogen peroxide, and when the waste sulfuric acid regenerated by the sulfuric acid regeneration device 1 does not contain hydrogen peroxide. Need not be provided. In this respect, this embodiment will be described using an aspect in which hydrogen peroxide is contained in waste sulfuric acid (that is, used sulfuric acid / hydrogen peroxide).

  In addition, a cooling unit 30 for cooling the concentrated sulfuric acid heated and concentrated is connected to each of the product tanks 20 a and 20 b through a connecting pipe 29. The connecting pipe 29 is provided with a driving unit 23 such as a pump for applying a driving force to the concentrated sulfuric acid in the connecting pipe 29.

  The cooling unit 30 includes a cooling tank 31 for storing concentrated sulfuric acid, and a driving unit 33 such as a pump for applying a driving force to the concentrated sulfuric acid stored in the cooling tank 31 and discharging the concentrated sulfuric acid. Yes. In addition, a pipe (not shown) for flowing cooling water is provided at the periphery of the cooling tank 31, and the concentrated sulfuric acid accommodated in the cooling tank 31 is cooled by flowing cooling water through the pipe. It has come to be. In addition, in this Embodiment, although demonstrated using the aspect with which two cooling tanks are provided, it is an example to the last, and only one cooling tank may be provided, and three or more are provided. It may be.

  In addition, a processing liquid generation unit 50 that prepares a processing liquid to be supplied to a substrate processing unit 60 described later is connected to the cooling unit 30 via a connecting pipe 39. The treatment liquid generator 50 is provided in the treatment liquid tank 51 for containing a sulfuric acid aqueous solution as a material for the treatment liquid, a circulation pipe 58 for circulating the sulfuric acid aqueous solution in the treatment liquid tank 51, and the circulation pipe 58. A driving unit 53 such as a pump for applying a driving force to the aqueous sulfuric acid solution stored in the treatment liquid tank 51 and a heating unit 52 for heating the aqueous sulfuric acid solution circulating in the circulation pipe 58 are provided. The circulation pipe 58 is provided with a processing liquid supply pipe 59 for supplying sulfuric acid / hydrogen peroxide as a processing liquid to a substrate processing unit 60 described later. The processing liquid supply pipe 59 is provided corresponding to each of the plurality of substrate processing units 60.

  Further, in the treatment liquid tank 51, a premixing unit 40 for mixing concentrated sulfuric acid (for example, concentrated sulfuric acid having a concentration of 98%) and pure water (DIW) is connected via a connecting pipe 49 provided with an opening / closing valve 47. Are connected. The pre-mixing unit 40 includes a mixing tank 41 to which concentrated sulfuric acid and pure water are supplied, a circulation pipe 48 for circulating the concentrated sulfuric acid and pure water in the mixing tank 41, and a mixing tank provided in the circulation pipe 48. 41, and a driving unit 43 such as a pump for applying a driving force to concentrated sulfuric acid and pure water accommodated in 41. In addition, in this Embodiment, although demonstrated using the aspect with which two mixing tanks are provided, it is an example to the last, only one mixing tank may be provided, and three or more are provided. It may be.

  Further, each of the treatment liquid supply pipes 59 is connected to a hydrogen peroxide solution supply unit 56 that generates sulfuric acid / hydrogen peroxide by supplying hydrogen peroxide solution to the sulfuric acid aqueous solution downstream of the opening / closing valve 57. . The hydrogen peroxide solution supply unit 56 may be branched from one hydrogen peroxide solution supply unit 56 and connected to each treatment liquid supply pipe 59. A hydrogen oxide water supply unit 56 may be provided.

  A substrate processing unit 60 for processing the substrate W to be processed with sulfuric acid / hydrogen peroxide supplied from the processing liquid supply pipe 59 is provided on the downstream side of the processing liquid supply pipe 59. Note that a plurality of (for example, 20) processing liquid supply pipes 59 and substrate processing units 60 are provided. Then, by opening and closing the open / close valve 57 provided in each of the processing liquid supply pipes 59, the generated sulfuric acid / hydrogen peroxide is appropriately supplied to each substrate processing unit 60. Examples of the substrate W to be processed include a wafer and a glass substrate.

  Further, the substrate processing unit 60 is provided with a drain pipe 69 for discharging sulfuric acid / hydrogen peroxide, which is a used processing liquid used in the substrate processing unit 60, and through the drain pipe 69, Used sulfuric acid / hydrogen peroxide is discharged to the deaeration tank 71. In this embodiment, two sets of the deaeration tank 71, the circulation pipe 78, the drive unit 73, and the heating unit 72 are provided, and one set of the deaeration tank 71, the circulation pipe 78, the drive unit 73, and When the hydrogen peroxide contained in the used sulfuric acid / hydrogen peroxide is decomposed using the heating unit 72, the used sulfuric acid / hydrogen peroxide used in the substrate processing unit 60 is placed in another set of degassing tanks 71. Water is discharged through the drainage pipe 69. The selection of which of the two degassing tanks 71 is used to discharge the used sulfuric acid / hydrogen peroxide is performed by switching the three-way valve 74 provided in the drainage pipe 69.

  3, orifices 13a and 13b, on-off valves 14a, 14b, 22a, 22b, 27a, 27b, 47, 57, 77, heating units 17a, 17b, 52, 72, driving units 23, 33, The control part 80 which controls these is connected to 43,53,73, the vacuum pump 24, the three-way valve 74, etc.

  By the way, in the present embodiment, a computer program for causing the substrate processing apparatus to execute a substrate processing method described later is stored in the storage medium 86 (see FIG. 3). The substrate processing apparatus also includes a computer 85 that receives the storage medium 86. The control unit 80 is configured to receive a signal from the computer 85 and control the substrate processing apparatus itself. In the present application, the storage medium 86 means, for example, a CD, DVD, MD, hard disk, RAM, or the like.

  Next, the operation and effect of the present embodiment having such a configuration will be described.

(Processing liquid supply)
First, a process until the sulfuric acid / hydrogen peroxide as a processing liquid is supplied to the substrate W to be processed will be described.

  First, 98% concentrated sulfuric acid and pure water (DIW) are supplied to the mixing tank 41. Next, a driving force is applied to the concentrated sulfuric acid and pure water stored in the mixing tank 41 by the driving unit 43, and the concentrated sulfuric acid and pure water are mixed with each other by being circulated through the circulation pipe 48. At this time, the opening / closing valve 47 provided in the connecting pipe 49 is closed.

  After the concentrated sulfuric acid and pure water are mixed in this way, the open / close valve 47 is opened in response to a signal from the control unit 80, and the concentrated sulfuric acid and pure water are introduced into the processing liquid tank 51 through the connecting pipe 49. A sulfuric acid aqueous solution generated by mixing is supplied and accommodated in the processing liquid tank 51.

  Next, a driving force is applied from the drive unit 53 to the aqueous sulfuric acid solution stored in the processing liquid tank 51, and the aqueous sulfuric acid solution is circulated through the circulation pipe 58. At this time, the heating unit 52 is controlled by the control unit 80 so that the aqueous sulfuric acid solution has an appropriate temperature.

  When the sulfuric acid / hydrogen peroxide is supplied to the substrate W to be processed, the open / close valve 57 is opened in response to a signal from the controller 80. Then, the hydrogen peroxide solution is added from the hydrogen peroxide solution supply unit 56 to the sulfuric acid aqueous solution supplied from the processing solution generation unit 50 to generate sulfuric acid / hydrogen peroxide. Then, the sulfuric acid / hydrogen peroxide generated in this way is supplied to the substrate to be processed W, and the substrate to be processed W is processed with sulfuric acid / hydrogen peroxide.

(Regeneration of treatment liquid)
Next, a process until the production of concentrated sulfuric acid from sulfuric acid / hydrogen peroxide, which is a processing liquid used when processing the target substrate W, will be described.

  The used sulfuric acid / hydrogen peroxide used in processing the substrate W to be processed is sent to the deaeration tank 71 through the drainage pipe 69 and accommodated in the deaeration tank 71.

  Next, the used sulfuric acid superwater accommodated in the deaeration tank 71 receives a driving force from the driving unit 73 and is circulated in the circulation pipe 78. In this way, while the used sulfuric acid / hydrogen peroxide is being circulated in the circulation pipe 78, the used sulfuric acid / hydrogen peroxide is heated by the heating unit 72. Then, when the used sulfuric acid / hydrogen peroxide is heated, hydrogen peroxide contained in the used sulfuric acid / hydrogen peroxide is decomposed to become water and oxygen. At this time, the open / close valve 77 provided in the connecting pipe 79 is closed. By the way, in this Embodiment, as mentioned above, two sets of the deaeration tank 71, the circulation pipe 78, the drive part 73, and the heating part 72 are provided. When the hydrogen peroxide contained in the used sulfuric acid / hydrogen peroxide is decomposed using one set of the deaeration tank 71, the circulation pipe 78, the drive unit 73, and the heating unit 72, another set of The used sulfuric acid / hydrogen peroxide used in the substrate processing unit 60 is discharged into the deaeration tank 71 through the drainage pipe 69. For this reason, the used sulfuric acid overwater used in the substrate processing unit 60 can always be collected in the deaeration tank 71.

  After the hydrogen peroxide contained in the used sulfuric acid / hydrogen peroxide was decomposed in the deaeration unit 70, the open / close valve 77 provided in the connecting pipe 79 was opened, and the hydrogen peroxide was removed from the supply tank 10. Waste sulfuric acid is sent. At this time, the on-off valves 14a and 14b are closed.

  After the waste sulfuric acid from which hydrogen peroxide has been removed is sent to the supply tank 10 and stored in the supply tank 10, the open / close valves 14a and 14b are opened, and the waste sulfuric acid is transferred from the supply tank 10 to the evaporation tanks 15a and 15b. Supplied. At this time, the pressure in the evaporation tanks 15 a and 15 b is reduced by the vacuum pump 24. On the other hand, since the supply tank 10 is communicated to the outside by the pressure adjusting pipe 11, the pressure in the supply tank 10 is substantially equal to the external pressure.

  By the way, in this Embodiment, waste sulfuric acid can be supplied little by little to the evaporation tanks 15a and 15b via the orifices 13a and 13b with a slight opening, and the waste sulfuric acid is rapidly supplied to the evaporation tanks 15a and 15b. Since this can be prevented, waste sulfuric acid can be prevented from bumping in the evaporation tanks 15a and 15b.

  In the present embodiment, since the waste sulfuric acid passes through the orifices 13a and 13b having a slight opening, the flow of gas between the supply tank 10 and the evaporation tanks 15a and 15b is blocked by the waste sulfuric acid. The evaporation tanks 15a and 15b can be depressurized while making the supply tank 10 substantially equal to the external pressure. In this way, since the supply tank 10 is maintained substantially equal to the external pressure, it is possible to prevent the waste sulfuric acid from boiling even when high-temperature waste sulfuric acid is supplied to the supply tank 10. Furthermore, the inner surface of the supply tank 10 may be uneven. Thus, when the inner surface has an uneven shape, the surface area of the inner surface of the supply tank 10 can be increased, and the occurrence of bumping can be more reliably prevented. In addition, a member such as a boiling stone may be placed in the supply tank 10, and it is possible to more reliably prevent bumping from occurring by inserting a member such as a boiling stone in this way.

  In addition, as a method for preventing the waste sulfuric acid from suddenly boiling in the supply tank 10 as described above, it is conceivable to lower the temperature of the waste sulfuric acid supplied to the supply tank 10, but it is supplied to the supply tank 10 in this way. When the temperature of the waste sulfuric acid is lowered, the waste sulfuric acid supplied to the evaporation tanks 15a and 15b is also cooled. Therefore, extra energy is required to remove the water in the waste sulfuric acid in the evaporation tanks 15a and 15b. Efficiency will be reduced. On the other hand, according to the present embodiment, such extra energy is beneficial in that it is unnecessary.

  Moreover, when a variable orifice or an air operated valve whose opening degree can be changed is used as the orifices 13a and 13b, the width of the flow path through which the waste sulfuric acid flows can be adjusted as appropriate. For this reason, the flow of gas between the supply tank 10 and the evaporation tanks 15a and 15b can be reliably blocked by the waste sulfuric acid flowing in the orifices 13a and 13b, and the supply tank 10 is made approximately equal to the external pressure. It is possible to reliably achieve decompression of the evaporation tanks 15a and 15b.

  Further, in the present embodiment, since the waste sulfuric acid in the evaporation tanks 15a and 15b can be heated under reduced pressure, the water in the waste sulfuric acid can be evaporated at a lower temperature than that performed under normal pressure. It can concentrate efficiently. The evaporated water is cooled by the heat exchanger 16 and then discharged to the outside through the drain pipe 19.

  In addition, after all the waste sulfuric acid in the supply tank 10 is supplied to the evaporation tanks 15a and 15b, the open / close valves 14a and 14b are closed in response to a signal from the control unit 80.

  After the water is removed and the waste sulfuric acid is concentrated as described above, this concentrated sulfuric acid is supplied to one of the product tanks 20a and 20b (in this embodiment, hereinafter, the concentrated sulfuric acid is supplied to the product tank 20a). This will be described with reference to the embodiment. At this time, the opening / closing valve 22a is opened and the opening / closing valve 22b is closed. The open / close valve 27a is opened, and the inside of the product tank 20a to which concentrated sulfuric acid is supplied is decompressed by the vacuum pump 24. For this reason, the concentrated sulfuric acid can be smoothly moved from the decompressed evaporation tanks 15a and 15b to the product tank 20a. At this time, the open / close valve 27b is closed, and the inside of the product tank 20b is not depressurized by the vacuum pump 24.

  After all of the concentrated sulfuric acid generated in the evaporation tanks 15a and 15b is stored in the product tank 20a, the open / close valve 27a is closed and the inside of the product tank 20a is not depressurized by the vacuum pump 24. Thereafter, the leak valve 25a is opened and the inside of the product tank 20a is returned to normal pressure. After the opening / closing valve 27a is closed, the opening / closing valve 27b is opened instead, and the product tank 20b starts to be depressurized. Thereafter, the opening / closing valve 22b is opened, and the newly generated concentrated sulfuric acid is supplied and stored in the decompressed product tank 20b. At this time, the opening / closing valve 22a is closed.

  Concentrated sulfuric acid in the product tank 20 a receives a driving force from the drive unit 23 and is sent from the product tank 20 a to the cooling tank 31. In addition, piping for flowing cooling water is provided in the periphery of the cooling tank 31, and the concentrated sulfuric acid accommodated in the cooling tank 31 is cooled by flowing cooling water into this piping. Then, after the concentrated sulfuric acid is cooled in the cooling tank 31 in this way, the concentrated sulfuric acid receives a driving force from the driving unit 33 and is sent to the processing liquid tank 51. Then, the concentrated sulfuric acid regenerated in this way and the mixed solution of concentrated sulfuric acid and pure water supplied from the pre-mixing unit 40 are mixed in the treatment liquid tank 51 and the circulation pipe 58.

  According to the present embodiment, while the concentrated sulfuric acid is being supplied from one product tank 20a to the cooling tank 31, the other product tank 20b is decompressed and newly generated in the product tank 20b. Sulfuric acid is supplied. For this reason, since the concentrated sulfuric acid produced | generated by the evaporation tanks 15a and 15b can be supplied to the product tank 20b, without stopping, the time required in order to reproduce | regenerate sulfuric acid can be shortened.

  By the way, as shown in FIG. 2, when the pressurizing unit 11 ′ that increases the pressure in the supply tank 10 is used as the pressure adjusting unit, the supply tank is more than when the pressure adjusting tube 11 is used as the pressure adjusting unit. Since the pressure in 10 can be made higher, it is possible to more reliably prevent waste sulfuric acid from bumping into the supply tank 10. The pressurizing unit 11 ′ is configured to increase the pressure in the supply tank 10 (for example, about 0.3 MPa) by supplying an inert gas such as nitrogen into the supply tank 10.

  Moreover, by providing such a pressurizing part 11 ', the pressure in the supply tank 10 can be freely adjusted, and the flow rate of waste sulfuric acid supplied into the evaporation tanks 15a and 15b can be adjusted. When fixed orifices are used as the orifices 13a and 13b, the opening degree cannot be adjusted. Therefore, the flow rate of the waste sulfuric acid supplied into the evaporation tanks 15a and 15b by adjusting the pressure by the pressurizing unit 11 ′ is adjusted. It is beneficial to adjust.

Modification of First Embodiment The flow of waste sulfuric acid from the supply tank 10 to the evaporation tanks 15a and 15b and the flow of concentrated sulfuric acid from the evaporation tanks 15a and 15b to the product tanks 20a and 20b are as described above. A modification example different from the first embodiment will be described below. Note that portions overlapping the description of the first embodiment will be described as appropriate.

  More specifically, in this modification, the on-off valves 14a and 14b are always open, and when the amount of waste sulfuric acid stored in the supply tank 10 exceeds a certain amount, the supply tank 10 and the evaporation tank The waste sulfuric acid always flows to 15a and 15b. (Note that when the amount of waste sulfuric acid to be regenerated is small, one of the two on-off valves 14a and 14b is closed.)

  In addition, any one of the opening / closing valves 22a and 22b (for example, the opening / closing valve 22a) is always in an open state, and when the amount of concentrated sulfuric acid stored in the evaporation tanks 15a and 15b becomes a certain amount or more, the evaporation tank. Concentrated sulfuric acid always flows from 15a, 15b to any one of the product tanks 20a, 20b (for example, the product tank 20a). By the way, if the on-off valves 14a and 14b are opened as described above, waste sulfuric acid before concentration always flows from the supply tank 10 to the evaporation tanks 15a and 15b, but the specific gravity of sulfuric acid is heavier than that of water. Since the supply pipe 21 is connected to the bottom surfaces of the evaporation tanks 15a and 15b and concentrated sulfuric acid is sent from the bottom surfaces of the evaporation tanks 15a and 15b to the product tank 20a, concentrated sulfuric acid not mixed with water is supplied to the product tank 20a. be able to.

  In the present modification as well, as in the first embodiment, after concentrated sulfuric acid is stored in one product tank 20a, the concentrated sulfuric acid is supplied from one product tank 20a to the cooling tank 31. The other product tank 20b is depressurized, and the newly generated concentrated sulfuric acid is supplied to the product tank 20b.

  Incidentally, even in such a modified example, the same effects as those of the first embodiment can be naturally obtained.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS.

  Although 1st Embodiment was the aspect in which the deaeration tank 71 and the supply tank 10 comprised a different body, in this Embodiment, the deaeration tank 71 of the deaeration part 70 comprises a supply tank. ing. The deaeration tank 71 is provided with a pressure adjusting pipe 76 communicated to the outside as a pressure adjusting unit. In the second embodiment, other configurations are substantially the same as those in the first embodiment.

  In the second embodiment shown in FIG. 4 and FIG. 5, the same parts as those in the first embodiment shown in FIG. 1 to FIG.

  Hereinafter, the operation and effect of the present embodiment when the treatment liquid is regenerated will be described. In addition, the part which overlaps description with 1st Embodiment is demonstrated, abbreviate | omitting suitably.

  By the way, since the operation and effect at the time of supplying the processing liquid in the present embodiment are the same as those in the first embodiment, the description thereof is omitted.

  Used sulfuric acid / hydrogen peroxide used for processing the substrate W to be processed by the substrate processing unit 60 is sent to the deaeration tank 71 via the drainage pipe 69 and accommodated in the deaeration tank 71. .

  By the way, also in this Embodiment, two sets of the deaeration tank 71, the circulation pipe 78, the drive part 73, and the heating part 72 are provided. When the hydrogen peroxide contained in the used sulfuric acid / hydrogen peroxide is decomposed using one set of the deaeration tank 71, the circulation pipe 78, the drive unit 73, and the heating unit 72, another set of The used sulfuric acid / hydrogen peroxide used in the substrate processing unit 60 is discharged into the deaeration tank 71 through the drainage pipe 69. For this reason, the used sulfuric acid overwater used in the substrate processing unit 60 can always be collected in the deaeration tank 71.

  The used sulfuric acid superwater accommodated in the deaeration tank 71 receives a driving force from the driving unit 73 and is circulated in the circulation pipe 78. In this way, while the used sulfuric acid superwater is circulated in the circulation pipe 78, the used sulfuric acid hydrogen is heated by the heating unit 72, and hydrogen peroxide contained in this used sulfuric acid hydrogen peroxide is used. Is decomposed into water and oxygen. At this time, the open / close valve 77 provided in the connecting pipe 79 is closed.

  After the hydrogen peroxide contained in the used sulfuric acid / hydrogen peroxide is decomposed in the deaeration unit 70, the opening / closing valve 77 provided in the connecting pipe 79 is opened, and the deaeration tank 71 is transferred to the evaporation tanks 15a and 15b. Waste sulfuric acid is supplied. At this time, the pressure in the evaporation tanks 15 a and 15 b is reduced by the vacuum pump 24. On the other hand, since the deaeration tank 71 communicates with the outside through the pressure adjusting pipe 76, the pressure in the deaeration tank 71 is substantially equal to the external pressure.

  By the way, also in this embodiment, waste sulfuric acid can be supplied little by little to the evaporation tanks 15a and 15b via the orifices 13a and 13b with a slight opening, and the waste sulfuric acid is supplied to the evaporation tanks 15a and 15b abruptly. Since this can be prevented, waste sulfuric acid can be prevented from bumping in the evaporation tanks 15a and 15b.

  Further, since the waste sulfuric acid passes through the orifices 13a and 13b having a slight opening, the flow of gas between the deaeration tank 71 and the evaporation tanks 15a and 15b is blocked by the waste sulfuric acid, The evaporation tanks 15a and 15b can be decompressed while making the air tank 71 substantially equal to the external pressure. As described above, since the deaeration tank 71 is maintained substantially equal to the external pressure, the waste sulfuric acid can be prevented from bumping even when high temperature waste sulfuric acid is supplied to the deaeration tank 71. Further, the inner surface of the deaeration tank 71 may be uneven. Thus, when the inner surface has an uneven shape, the surface area of the inner surface of the deaeration tank 71 can be increased, and the occurrence of bumping can be more reliably prevented. In addition, a member such as a boiling stone may be placed in the deaeration tank 71. By inserting a member such as a boiling stone in this way, it is possible to more reliably prevent bumping.

  Moreover, when a variable orifice or an air operated valve whose opening degree can be changed is used as the orifices 13a and 13b, the width of the flow path through which the waste sulfuric acid flows can be adjusted as appropriate. For this reason, the flow of gas between the deaeration tank 71 and the evaporation tanks 15a and 15b can be reliably interrupted by the waste sulfuric acid flowing in the orifices 13a and 13b, and the deaeration tank 71 can be roughly connected to the external pressure. It is possible to reliably achieve depressurization of the evaporation tanks 15a and 15b while making them equal.

  Further, in the present embodiment, since the waste sulfuric acid in the evaporation tanks 15a and 15b can be heated under reduced pressure, the water in the waste sulfuric acid can be evaporated at a lower temperature than that performed under normal pressure. It can concentrate efficiently.

  In addition, after all the waste sulfuric acid in the deaeration tank 71 is supplied to the evaporation tanks 15a and 15b, the open / close valves 14a and 14b are closed in response to a signal from the control unit 80.

  After the water is removed and the waste sulfuric acid is concentrated as described above, this concentrated sulfuric acid is supplied to one of the product tanks 20a and 20b (in this embodiment, hereinafter, the concentrated sulfuric acid is supplied to the product tank 20a). This will be described with reference to the embodiment. At this time, the opening / closing valve 22a is opened and the opening / closing valve 22b is closed. The open / close valve 27a is opened, and the inside of the product tank 20a to which concentrated sulfuric acid is supplied is decompressed by the vacuum pump 24. For this reason, the concentrated sulfuric acid can be smoothly moved from the decompressed evaporation tanks 15a and 15b to the product tank 20a. At this time, the open / close valve 27b is closed, and the inside of the product tank 20b is not depressurized by the vacuum pump 24.

  After all of the concentrated sulfuric acid generated in the evaporation tanks 15a and 15b is stored in the product tank 20a, the open / close valve 27a is closed and the inside of the product tank 20a is not depressurized by the vacuum pump 24. Thereafter, the leak valve 25a is opened and the inside of the product tank 20a is returned to normal pressure. After the opening / closing valve 27a is closed, the opening / closing valve 27b is opened instead, and the product tank 20b starts to be depressurized. Thereafter, the opening / closing valve 22b is opened, and the newly generated concentrated sulfuric acid is supplied and stored in the decompressed product tank 20b. At this time, the opening / closing valve 22a is closed.

  Concentrated sulfuric acid in the product tank 20 a receives a driving force from the drive unit 23 and is sent from the product tank 20 a to the cooling tank 31. Then, after the concentrated sulfuric acid is cooled in the cooling tank 31, the concentrated sulfuric acid receives a driving force from the driving unit 33 and is sent to the processing liquid tank 51. Then, the concentrated sulfuric acid regenerated in this way and the mixed solution of concentrated sulfuric acid and pure water supplied from the pre-mixing unit 40 are mixed in the treatment liquid tank 51 and the circulation pipe 58.

  Also according to the present embodiment, while concentrated sulfuric acid is being supplied from one product tank 20a to the cooling tank 31, another product tank 20b is decompressed and newly generated concentrated sulfuric acid is generated in the product tank 20b. Is to be supplied. For this reason, since the concentrated sulfuric acid produced | generated by the evaporation tanks 15a and 15b can be supplied to the product tank 20b, without stopping, the time required in order to reproduce | regenerate sulfuric acid can be shortened.

  By the way, as shown in FIG. 5, when the pressurizing unit 76 ′ that increases the pressure in the deaeration tank 71 is used as the pressure adjusting unit, the pressure adjusting unit is removed more than when the pressure adjusting pipe 76 is used as the pressure adjusting unit. Since the pressure in the air tank 71 can be made higher, it is possible to more reliably prevent the waste sulfuric acid from boiling suddenly in the deaeration tank 71.

  Moreover, by providing such a pressurizing part 76 ', the pressure in the deaeration tank 71 can be adjusted freely, and the flow rate of the waste sulfuric acid supplied into the evaporation tanks 15a and 15b can be adjusted. .

  Also in this embodiment, the same configuration as that of the modification of the first embodiment can be adopted. More specifically, when the on-off valves 14a and 14b are always open and the amount of waste sulfuric acid stored in the deaeration tank 71 exceeds a certain level, the evaporation tanks 15a and 15b are removed from the deaeration tank 71. It may be configured so that the waste sulfuric acid always flows. Further, when any one of the opening / closing valves 22a and 22b is always opened and the amount of concentrated sulfuric acid stored in the evaporation tanks 15a and 15b exceeds a certain level, the evaporation tanks 15a and 15b to the product tanks 20a and 20b. Concentrated sulfuric acid may always flow to any one of the above.

DESCRIPTION OF SYMBOLS 1 Sulfuric acid regenerating apparatus 5 Evaporating part 10 Supply tank 11 Pressure adjusting pipe (pressure adjusting part)
11 'Pressurizing part (pressure adjusting part)
12a, 12b Supply pipes 13a, 13b Orifices 15a, 15b Evaporating tanks 17a, 17b Heating units 20a, 20b Product tank (product receiving tank)
24 Vacuum pump (decompression unit)
27a, 27b Open / close valve 30 Cooling unit 40 Pre-mixing unit 50 Processing liquid generation unit 56 Hydrogen peroxide solution supply unit 60 Substrate processing unit 70 Deaeration unit 80 Control unit 85 Computer 86 Storage medium

Claims (12)

A substrate processing unit for processing a substrate to be processed using sulfuric acid;
A sulfuric acid regenerating apparatus for regenerating waste sulfuric acid used in the substrate processing unit,
The sulfuric acid regenerator is:
An evaporation tank containing the waste sulfuric acid;
A heating unit for heating the waste sulfuric acid accommodated in the evaporation tank;
A supply tank for containing the waste sulfuric acid and supplying the waste sulfuric acid to the evaporation tank;
A supply pipe connecting the supply tank and the evaporation tank;
A flow rate adjusting unit for adjusting an amount of the waste sulfuric acid provided in the supply pipe and supplied from the supply tank to the evaporation tank;
A first pressure reducing unit provided in the evaporation tank, for reducing the pressure in the evaporation tank;
A substrate processing apparatus, comprising: a pressure adjusting unit that is provided in the supply tank and makes a pressure in the supply tank higher than a pressure in the evaporation tank.   2. The gas flow between the supply tank and the evaporation tank is blocked by the waste sulfuric acid when the waste sulfuric acid is supplied from the supply tank to the evaporation tank. Substrate processing equipment.   The substrate processing apparatus according to claim 1, wherein the pressure adjusting unit is a pressure adjusting tube provided in the supply tank and connected to the outside.   The substrate processing apparatus according to claim 1, wherein the pressure adjusting unit is a pressurizing unit that increases a pressure in the supply tank. A product receiving tank connected to the evaporation tank and receiving sulfuric acid concentrated in the evaporation tank;
A second decompression unit connected to the product receiving tank and for decompressing the product receiving tank;
The substrate processing apparatus according to claim 1, further comprising:   The substrate processing apparatus according to claim 5, wherein when the concentrated sulfuric acid is transferred from the evaporation tank to the product receiving tank, the inside of the product receiving tank is depressurized by the second decompression unit. . A plurality of product receiving tanks connected to the evaporation tank and receiving sulfuric acid concentrated in the evaporation tank;
A second decompression unit connected to each of the product receiving tanks and for depressurizing the inside of the product receiving tanks,
When the concentrated sulfuric acid is transferred from the evaporation tank to at least one of the product receiving tanks, the inside of the product receiving tank to which the concentrated sulfuric acid is transferred is depressurized and concentrated by the second pressure reducing unit. 5. The substrate processing apparatus according to claim 1, wherein the inside of the product receiving tank to which sulfuric acid is not transferred is not depressurized. The substrate processing unit processes the substrate to be processed using waste sulfuric acid containing hydrogen peroxide,
A deaeration unit for decomposing and removing the hydrogen peroxide contained in the waste sulfuric acid is connected to the substrate processing unit,
The substrate processing apparatus according to claim 1, wherein the supply tank contains waste sulfuric acid from which the hydrogen peroxide has been removed in the deaeration unit. The substrate processing unit processes the substrate to be processed using waste sulfuric acid containing hydrogen peroxide,
A deaeration unit for decomposing and removing the hydrogen peroxide contained in the waste sulfuric acid is connected to the substrate processing unit,
The deaeration unit includes a deaeration tank that stores the waste sulfuric acid containing the hydrogen peroxide, and a heating unit that heats the waste sulfuric acid containing the hydrogen peroxide,
The substrate processing apparatus according to claim 1, wherein the supply tank is the deaeration tank. Treating the substrate to be treated with a treatment solution containing sulfuric acid;
Regenerating the waste sulfuric acid used in the substrate processing unit,
Recycling waste sulfuric acid
Supplying waste sulfuric acid from the supply tank to the evaporation tank;
Heating the waste sulfuric acid accommodated in the evaporation tank under reduced pressure,
When supplying the waste sulfuric acid from the supply tank to the evaporation tank, the flow rate of the waste sulfuric acid is adjusted, and the pressure in the supply tank is higher than the pressure in the evaporation tank. A substrate processing method.   The gas flow between the supply tank and the evaporation tank is blocked by the waste sulfuric acid when the waste sulfuric acid is supplied from the supply tank to the evaporation tank. Substrate processing method. In a storage medium storing a computer program for causing a substrate processing apparatus to execute a substrate processing method,
The substrate processing method includes:
Treating the substrate to be treated with a treatment solution containing sulfuric acid;
Regenerating the waste sulfuric acid used in the substrate processing unit,
Recycling waste sulfuric acid
Supplying waste sulfuric acid from the supply tank to the evaporation tank;
Heating the waste sulfuric acid accommodated in the evaporation tank under reduced pressure,
When supplying the waste sulfuric acid from the supply tank to the evaporation tank, the flow rate of the waste sulfuric acid is adjusted, and the pressure in the supply tank is higher than the pressure in the evaporation tank. A storage medium characterized by that.

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