Organic solvent recovery apparatus, substrate processing apparatus, and organic solvent recovery method

Abstract

The present invention provides a technique capable of separating water from a liquid mixture with high reliability. This organic solvent recovery device is provided with a recovery pipe (510), a first dehydrator (60), a switching unit (50), and a control unit. A liquid mixture of the organic solvent discharged from the treatment unit (4) and water flows through the recovery pipe (510). The first dehydrator (60) includes a first membrane separator (62) including a first separation membrane (62c) having an application range of solvent concentration, and the first membrane separator (62) separates water from the mixed solution to increase the solvent concentration of the mixed solution. The switching unit (50) switches between a first state in which the solvent concentration of the mixed liquid is increased by the first dehydrator and a second state in which the mixed liquid is supplied to another portion different from the first dehydrator (60). The control unit causes the switching unit (50) to select the first state when the solvent concentration of the mixed liquid is a first value equal to or greater than the concentration lower limit value of the first separation membrane (62c), and causes the switching unit (50) to select the second state when the solvent concentration of the mixed liquid is a second value less than the concentration lower limit value.

Description

Technical Field

[0001] The invention relates to an organic solvent recovery device, a substrate processing device and an organic solvent recovery method. Background Art

[0002] Patent document 1 discloses an IPA recovery system for recovering aqueous IPA (isopropyl alcohol) discharged from a processing unit for processing a substrate. The IPA recovery system includes a storage tank, a circulation piping, a pump, a dehydration unit, and a filter. The aqueous IPA from the processing unit is supplied to the storage tank. The circulation piping is connected to the storage tank so that the aqueous IPA from the storage tank returns to the storage tank. The pump is provided in the circulation piping to transport the aqueous IPA from the upstream end to the downstream end of the circulation piping. The filter is provided in the circulation piping to remove foreign matter in the aqueous IPA. The dehydration unit is provided in the circulation piping to remove water from the aqueous IPA.

[0003] The IPA recovery system circulates aqueous IPA through a circulation path consisting of a storage tank and circulation piping. This circulation allows the aqueous IPA to pass through a filter and dehydration unit. This increases the IPA concentration of the circulating aqueous IPA and reduces foreign matter in the aqueous IPA. In other words, this circulation allows clean aqueous IPA with a high IPA concentration to be stored in the storage tank. The aqueous IPA in this storage tank is then resupplied to the processing unit, thereby reducing the amount of IPA waste.

[0004] [Background Art Literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-41505 Summary of the Invention

[0007] [Problems to be solved by the invention]

[0008] The dehydration unit can utilize a membrane separator with a separation membrane. Such membranes have an applicable range of solvent concentration. In other words, if a mixed liquid with a solvent concentration below the lower limit of the applicable range attempts to pass through the membrane, it may cause problems with the membrane.

[0009] Therefore, an object of the present invention is to provide a technology capable of separating water from a mixed liquid with high reliability.

[0010] [Technical means to solve the problem]

[0011] The first form is an organic solvent recovery device comprising: a recovery pipe for circulating a mixed liquid of an organic solvent and water discharged from a processing unit for processing a substrate; a first dehydrator including a first separation membrane having an applicable range of solvent concentration, which separates water from the mixed liquid to increase the solvent concentration of the mixed liquid; a switching unit for switching between a first state and a second state, the first state being a state in which the solvent concentration of the mixed liquid discharged from the processing unit is increased by the first dehydrator, and the second state being a state in which the mixed liquid discharged from the processing unit is supplied to another part different from the first dehydrator; and a control unit for causing the switching unit to select the first state when the solvent concentration of the mixed liquid is a first value greater than the lower limit of the applicable range, i.e., the lower limit of the concentration, and causing the switching unit to select the second state when the solvent concentration of the mixed liquid is a second value less than the lower limit of the concentration.

[0012] The second aspect is an organic solvent recovery device according to the first aspect, comprising a storage unit storing recipe information indicating processing contents of the substrate by the processing unit, and the control unit calculating the solvent concentration of the mixed liquid discharged from the processing unit based on the recipe information.

[0013] The third form is an organic solvent recovery device according to the second form, wherein the processing unit includes: a substrate holding portion for holding the substrate and rotating it at the same time; a spraying portion for sequentially spraying pure water and an organic solvent onto the main surface of the substrate held by the substrate holding portion; and a support cup having a cylindrical shape surrounding the substrate holding portion and catching the liquid scattered from the periphery of the substrate; the upstream end of the recovery pipe is connected to the support cup, and the recipe information sets the pure water flow rate and spraying time of the pure water sprayed onto the substrate, and the organic solvent sprayed onto the substrate. The solvent flow rate and ejection time, as well as the rotation speed of the substrate, are stored in the storage unit with correspondence information indicating the correspondence between the rotation speed and the pure water film amount, the pure water film amount being the amount of pure water on the main surface of the substrate, and the control unit calculates the pure water film amount based on the rotation speed of the substrate specified according to the recipe information and the correspondence information, and calculates the solvent concentration of the mixed liquid discharged from the processing unit based on the pure water film amount, the time integral value of the pure water flow rate, and the time integral value of the solvent flow rate.

[0014] A fourth aspect is the organic solvent recovery device according to the second aspect, further comprising a concentration sensor for measuring the solvent concentration of the mixed liquid, wherein the control unit controls the switching unit based on the solvent concentration of the mixed liquid measured by the concentration sensor.

[0015] A fifth aspect is the organic solvent recovery device according to any one of the first to fourth aspects, wherein the mixed liquid from a plurality of the treatment units flows through the recovery pipe.

[0016] The sixth aspect is an organic solvent recovery device according to any one of the first to fifth aspects, wherein the first dehydrator includes a first circulation section having a first circulation pipe provided with the first membrane separator, and the mixed liquid is circulated through the first circulation pipe.

[0017] A seventh aspect is the organic solvent recovery device according to any one of the first to sixth aspects, wherein the other portion includes a pipe for discharging the mixed liquid to the outside.

[0018] An eighth aspect is the organic solvent recovery apparatus according to any one of the first to sixth aspects, wherein the other portion includes a second dehydrator that separates water from the mixed liquid to increase the solvent concentration of the mixed liquid.

[0019] The ninth aspect is an organic solvent recovery device according to the eighth aspect, wherein the second dehydrator increases the solvent concentration of the mixed liquid to above the lower limit of the concentration of the first separation membrane, and supplies the mixed liquid having the solvent concentration above the lower limit to the first dehydrator.

[0020] The tenth aspect is the organic solvent recovery apparatus according to the eighth or ninth aspect, wherein the second dehydrator includes at least one of a distillation tower and an ultrasonic atomizing separator.

[0021] The 11th form is an organic solvent recovery device according to the 8th or 9th form, wherein the second dehydrator includes a second membrane separator having a second separation membrane, the lower limit of the applicable range of solvent concentration of the second separation membrane is less than the lower limit of the concentration of the first separation membrane, and the separation constant of the first separation membrane is higher than the separation constant of the second separation membrane.

[0022] The twelfth aspect is the organic solvent recovery apparatus according to the eleventh aspect, wherein the second dehydrator includes: a second circulation pipe in which the second membrane separator is installed; and a liquid feeding section provided in the second circulation pipe.

[0023] The 13th form is an organic solvent recovery device according to the 12th form, which is equipped with a concentration tank for storing the mixed liquid from the recovery piping, the first dehydrator includes a first circulation piping, the first circulation piping is connected to the concentration tank and is provided with the first membrane separator, the first circulation piping includes: a common circulation piping, which is provided with the liquid supply part; and a first individual piping, which is provided with the first membrane separator; the second circulation piping includes the common circulation piping, and a second individual piping provided with the second membrane separator, and the switching part switches the first state and the second state, the first state is a state in which the mixed liquid circulates through the concentration tank and the first circulation piping, and the second state is a state in which the mixed liquid circulates through the concentration tank and the second circulation piping.

[0024] A fourteenth aspect is a substrate processing apparatus comprising the organic solvent recovery apparatus according to any one of the first to thirteenth aspects, and the processing unit.

[0025] The 15th form is an organic solvent recovery method: it comprises: a concentration acquisition process, which acquires the solvent concentration of a mixed liquid of an organic solvent and water discharged from a processing unit for processing a substrate; and a dehydrator process, which uses a first membrane separator including a first separation membrane to separate water from the mixed liquid when the solvent concentration is a first value, thereby increasing the solvent concentration of the mixed liquid; and the first value is above the lower limit of the concentration of the applicable range of the solvent concentration of the first separation membrane.

[0026] [Effects of the Invention]

[0027] According to the first, fourteenth, and fifteenth aspects, the organic solvent recovery device can increase the solvent concentration of the mixed liquid with high reliability.

[0028] According to the second aspect, it is unnecessary to provide a concentration sensor, and thus the manufacturing cost can be reduced.

[0029] According to the third aspect, the solvent concentration can be calculated with high accuracy.

[0030] According to the fourth aspect, the solvent concentration can be obtained with high accuracy.

[0031] According to the fifth aspect, it is not necessary to provide switching units one-to-one with the plurality of processing units, but only a single switching unit is required, thereby reducing manufacturing costs.

[0032] According to the sixth aspect, the size required for the first membrane separator can be reduced.

[0033] According to the seventh aspect, the mixed liquid having a low solvent concentration can be discharged to the outside.

[0034] According to the eighth aspect, the amount of waste organic solvent can be further reduced.

[0035] According to the ninth aspect, after the second dehydrator raises the solvent concentration of the mixed liquid to above the lower limit of the concentration of the first separation membrane, the highly efficient first dehydrator can further raise the solvent concentration of the mixed liquid. Therefore, the solvent concentration of the mixed liquid can be raised more efficiently.

[0036] According to the tenth embodiment, the second dehydrator has a very low concentration lower limit. Therefore, even if the solvent concentration of the mixed liquid discharged from the treatment unit is very low, the second dehydrator can increase the solvent concentration of the mixed liquid to above the concentration lower limit of the first separation membrane.

[0037] According to the eleventh aspect, the second dehydrator can separate water from a mixed liquid having a solvent concentration lower than the lower concentration limit of the first separation membrane, thereby increasing the solvent concentration of the mixed liquid. Furthermore, after the second membrane separator increases the solvent concentration of the mixed liquid to above the lower concentration limit of the first separation membrane, the first membrane separator, which includes a first separation membrane having a higher separation constant, further increases the solvent concentration of the mixed liquid. Therefore, the organic solvent recovery device can increase the solvent concentration of the mixed liquid with higher efficiency.

[0038] According to the twelfth aspect, the size required for the second membrane separator can be reduced.

[0039] According to the thirteenth aspect, the first circulation pipe and the second circulation pipe share the liquid feeding portion, and therefore, the manufacturing cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a plan view schematically showing an example of a substrate processing apparatus.

[0041] Figure 2 It is a side view schematically showing an example of a processing unit.

[0042] Figure 3 It is a diagram schematically showing a first example of the substrate processing apparatus according to the first embodiment.

[0043] Figure 4 This is a diagram schematically showing an example of a specific configuration of the first dehydrator of the organic solvent recovery section.

[0044] Figure 5 This is a flowchart showing an example of the operation of the organic solvent recovery unit according to the first embodiment.

[0045] Figure 6 This is a diagram schematically showing an example of a processing unit according to the first embodiment.

[0046] Figure 7(a) to (f) in Table 1 are diagrams schematically showing an example of the state of the processing unit in each step of Table 1.

[0047] Figure 8 This is a graph showing an example of the distance between each position on the substrate and the center of the substrate, and the thickness of the pure water liquid film at each position.

[0048] Figure 9 (a) to (e) in Table 2 are diagrams schematically showing an example of the state of the processing unit in each step of Table 2.

[0049] Figure 10 This is a graph showing an example of the distance between each position on the substrate and the center of the substrate, and the thickness of the liquid film at each position.

[0050] Figure 11 This is a flowchart showing an example of the operation of the concentration estimating unit.

[0051] Figure 12 It is a diagram schematically showing a second example of the substrate processing apparatus according to the first embodiment.

[0052] Figure 13 It is a diagram schematically showing an example of a substrate processing apparatus according to a second embodiment.

[0053] Figure 14 This is a diagram schematically showing an example of an organic solvent recovery unit according to a third embodiment.

[0054] Figure 15 This is a diagram schematically showing an example of the second dehydrator.

[0055] Figure 16 This is a flowchart showing an example of the operation of the organic solvent recovery unit according to the third embodiment.

[0056] Figure 17 This is a diagram schematically showing an example of a second dehydrator according to the fourth embodiment.

[0057] Figure 18 This is a diagram schematically showing an example of an organic solvent recovery unit according to the fifth embodiment.

[0058] Figure 19 This is a diagram schematically showing an example of an organic solvent recovery unit according to the sixth embodiment.

[0059] Figure 20 This is a flowchart showing an example of the operation of the organic solvent recovery unit according to the sixth embodiment. DETAILED DESCRIPTION

[0060] The following describes the embodiments in detail with reference to the accompanying drawings. In the accompanying drawings, the dimensions and quantities of various components may be exaggerated or simplified as necessary for easier understanding. Components having the same configuration and function are denoted by the same reference numerals, and repeated descriptions are omitted in the following description.

[0061] In the following description, the same components are denoted by the same reference numerals and have the same names and functions, and their detailed descriptions may be omitted to avoid duplication.

[0062] In the following description, even if ordinal numbers such as "first" or "second" are sometimes used, these terms are used for convenience to facilitate understanding of the contents of the implementation method and are not limited to the order in which these ordinal numbers may occur.

[0063] When using expressions that express relative or absolute positional relationships (for example, "toward a direction," "along a direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.), unless otherwise specified in advance, the expression not only strictly expresses the positional relationship, but also expresses a state after relative displacement in terms of angle or distance within a tolerance or a range that can achieve the same degree of function. When using expressions that express an equal state (for example, "same," "equal," "homogeneous," etc.), unless otherwise specified in advance, the expression not only expresses a state of strict quantitative equality, but also expresses a state of difference with a tolerance or a range that can achieve the same degree of function. When using expressions that express shape (for example, "quadrilateral" or "cylindrical shape," etc.), unless otherwise specified in advance, the expression not only strictly expresses the shape geometrically, but also expresses a shape having, for example, concave-convex or chamfered corners within a range that can achieve the same degree of effect. When using an expression such as "including," "provided with," "having," "containing," or "having" a constituent element, the expression is not an exclusive expression that excludes the presence of other constituent elements. When the expression "at least one of A, B, and C" is used, the expression includes only A, only B, only C, any two of A, B, and C, and all of A, B, and C.

[0064] <First embodiment>

[0065] <1. Substrate Processing Apparatus>

[0066] Reference Figure 1 A substrate processing apparatus 100 according to the embodiment will be described. Figure 1 It is a plan view schematically showing an example of the substrate processing apparatus 100 .

[0067] The substrate processing apparatus 100 is a so-called single-wafer processing apparatus that processes target substrates W one by one. The target substrates W processed by the substrate processing apparatus 100 are, for example, semiconductor substrates. The target substrates W are, for example, disk-shaped.

[0068] The substrate processing apparatus 100 includes a load port 1 , a carrier robot 2 , a main transfer robot 3 , a processing unit 4 , an organic solvent recovery unit 5 , and a control unit 6 .

[0069] The loading port 1 is an interface for accessing the substrate W relative to the carrier C, which is a type of storage container for accommodating multiple substrates. For example, there are multiple loading ports 1 (3 in the example in the figure). The multiple loading ports 1 are arranged in a row in the horizontal direction, for example. The carrier C can be a type that stores the substrate W in a confined space (for example, FOUP (Front Opening Unified Pod, front-opening wafer transfer box), SMIF (Standard Mechanical InterFace, standard mechanical interface) wafer box, etc.), or a type that exposes the substrate W to the outside air (for example, OC (OpenCassette, open wafer cassette) etc.).

[0070] The carrier robot 2 is a transport device that transports substrates W. As an example, the carrier robot 2 is a horizontal multi-joint robot having a pair of hands 21, 21 for holding the substrates W and arms 22 connected to the hands 21. In addition, the carrier robot 2 has a drive mechanism (not shown) for rotating the hands 21 and flexing, extending, rotating, and raising and lowering the arms 22. The carrier robot 2 transports substrates W between the carrier C placed on the loading port 1 and the main transport robot 3. That is, the carrier robot 2 enters and exits the carrier C placed on the loading port 1, performing a carry-out operation (i.e., an operation of taking out the substrate W stored in the carrier C using the hands 21) and a carry-in operation (i.e., an operation of storing the substrate W held by the hands 21 in the carrier C). In addition, the carrier robot 2 enters and exits the transfer position to transfer substrates W to and from the main transport robot 3.

[0071] The main transfer robot 3 is a transfer device for transferring substrates W. For example, the main transfer robot 3 is a horizontal multi-joint robot having a pair of hands 31, 31 for holding the substrate W and an arm 32 connected to each hand 31. In addition, the main transfer robot 3 has a drive mechanism (not shown) for rotating each hand 31 and flexing, extending, rotating, and lifting each arm 32. The main transfer robot 3 transfers substrates W between the carrier robot 2 and each processing unit 4. That is, the main transfer robot 3 enters and exits the handover position and transfers substrates W to and from the carrier robot 2. In addition, the main transfer robot 3 enters and exits the processing unit 4 to perform a carry-in action (i.e., an action of carrying the substrate W held by the hand 31 into the processing unit 4) and a carry-out action (i.e., an action of carrying the substrate W in the processing unit 4 out using the hand 31).

[0072] The processing unit 4 performs a specified process on the substrate W using a processing liquid (e.g., a chemical solution, a rinse solution, and IPA). Here, for example, a plurality (e.g., three) of processing units 4 stacked vertically form a tower, and the tower is provided with a plurality (four in the example shown) of processing units 4 arranged to surround the main transfer robot 3. The specific structure of the processing unit 4 will be described below.

[0073] The organic solvent recovery unit 5 recovers the organic solvent from the treatment unit 4 and supplies it back to the treatment unit 4 after purification. For example, an organic solvent recovery unit 5 may be provided for each of the multiple towers, with each organic solvent recovery unit 5 recovering and supplying the organic solvent to each treatment unit 4 included in the corresponding tower. The specific structure of the organic solvent recovery unit 5 will be described below.

[0074] The control unit 6 controls the operation of each component of the substrate processing apparatus 100 (the load port 1, the carrier robot 2, the main transfer robot 3, the processing unit 4, and the organic solvent recovery unit 5). The control unit 6 comprises, for example, a conventional computer having circuitry. For example, the control unit 6 includes a CPU (Central Processor Unit) that performs various computations (data processing), a storage device, and a bus interconnecting these components. The storage device includes a ROM (Read Only Memory) that stores basic programs, a RAM (Random Access Memory) that serves as a work area for the CPU to perform specific processing (data processing), a flash memory, a hard disk drive, and other non-volatile storage devices. Alternatively, a program that specifies the processing to be performed by the control unit 6 may be stored in the storage device or RAM. In this case, for example, the CPU can execute the program, causing the control unit 6 to control the various components of the substrate processing apparatus 100, thereby executing the processing specified by the program in the substrate processing apparatus 100. In other words, the CPU can execute the program to implement circuitry in the control unit 6 that performs the processing specified by the program. However, part or all of the control performed by the control unit 6 (part or all of the circuits implemented by the control unit 6 ) may be executed (implemented) by hardware such as a dedicated logic circuit.

[0075] <2. Processing Unit>

[0076] Reference Figure 2 The processing unit 4 will be described. Figure 2 It is a side view schematically showing an example of the processing unit 4.

[0077] <2-1. Configuration of Processing Unit>

[0078] The processing unit 4 performs a designated process on the substrate W using a processing liquid (e.g., a chemical solution, a rinse solution, and IPA). The processing unit 4 includes, for example, a spin chuck 41 (an example of a substrate holder), a cup 42, and a discharge unit 430. The discharge unit 430 includes a nozzle 43. The spin chuck 41, cup 42, and nozzle 43 are housed in a processing chamber 44.

[0079] The spin chuck 41 holds the substrate W in a horizontal position (a position in which the thickness direction of the substrate W is in the vertical direction (vertical direction)) and rotates the substrate W about an axis (rotation axis) A extending vertically and passing through the center of its main surface. Specifically, the spin chuck 41 includes, for example, a spin base 411. The spin base 411 is a disc-shaped component, and is positioned with its thickness direction in the vertical direction. A plurality of chuck pins 412 are provided on the top surface of the spin base 411. The chuck pins 412 are arranged at equal intervals along a circumference corresponding to the periphery of the substrate W. A link mechanism (not shown) is connected to the chuck pins 412, which moves them between an abutment position and an open position. The "abutment position" is where the chuck pins 412 abut the periphery of the substrate W. The "open position" is where the chuck pins 412 are clear of the periphery of the substrate W. When each of the chuck pins 412 is in the abutment position, the substrate W is held (clamped) in a horizontal position above the spin base 411. When each of the multiple chuck pins 412 is in the open position, the substrate W is released from its grip. The link mechanism switches the position of the chuck pins 412 based on instructions from the control unit 6. In other words, the timing of holding and releasing the substrate W is controlled by the control unit 6. Furthermore, the spin base 411 is connected to a rotation motor 414 via a shaft 413 coaxial with the rotation axis A. The shaft 413 and the rotation motor 414 are housed in a housing 415. The rotation motor 414 rotates the shaft 413 about the rotation axis A. This causes the spin base 411, and consequently the substrate W held thereon, to rotate about the rotation axis A. The rotation motor 414 rotates the spin base 411 based on instructions from the control unit 6. In other words, the rotation speed of the spin base 411 (and consequently the substrate W), as well as the timing of starting and ending rotation, are controlled by the control unit 6.

[0080] The cup 42 has a cylindrical shape surrounding the spin chuck 41 and receives the processing liquid discharged from the substrate W held and rotated by the spin chuck 41. Specifically, the cup 42 includes, for example, a cylindrical guide portion 421 coaxially arranged with the rotation axis A; an inclined portion 422 connected to the upper end of the guide portion 421 and tapering upward in diameter; and a liquid receiving portion 423 connected to the lower end of the guide portion 421 and forming an upwardly open annular groove. The liquid receiving portion 423 is provided with a cup-side recovery pipe (f) for recovering the liquid received therein, specifically, a cup-side recovery pipe f for a chemical solution (not shown) and a cup-side recovery pipe 424 for IPA. Furthermore, a cup-lifting mechanism 425 is connected to the cup 42 to raise and lower it between a lower position and an upper position. The "lower position" refers to a position in which the upper end of the cup 42 (specifically, the upper end of the inclined portion 422) is positioned below the substrate W held by the spin chuck 41. The "upper position" is a position where the upper end of the retainer 42 is positioned above the substrate W held by the spin chuck 41. The retainer lifting mechanism 425 raises and lowers the retainer 42 in response to instructions from the control unit 6. In other words, the position of the retainer 42 is controlled by the control unit 6.

[0081] The discharge unit 430f, specifically the nozzle 43, discharges the processing liquid toward the upper surface of the substrate W held by the spin chuck 41. Here, for example, individual nozzles 43 are provided depending on the type of processing liquid. Specifically, there are nozzles 43f (below) for discharging chemical liquid (also referred to as "chemical liquid nozzle 43a"), nozzles 43f (below) for discharging rinse liquid (also referred to as "rinsing liquid nozzle 43b"), and nozzles 43f (below) for discharging IPA (also referred to as "IPA nozzle 43c").

[0082] The chemical nozzle 43a sprays a chemical solution toward the upper surface of the substrate W held by the spin chuck 41. The chemical nozzle 43a is connected to a chemical supply source 433a via a chemical pipe 432a through which a chemical valve 431a is inserted. When the chemical valve 431a is opened, the chemical solution is supplied to the chemical nozzle 43a through the chemical pipe 432a and sprayed from the chemical nozzle 43a. The chemical valve 431a opens and closes according to instructions from the control unit 6. In other words, the timing of spraying the chemical solution from the chemical nozzle 43a is controlled by the control unit 6. The chemical solution is, for example, hydrofluoric acid. However, the chemical solution is not limited to hydrofluoric acid and may also be a liquid containing at least one of sulfuric acid, acetic acid, nitric acid, hydrochloric acid, hydrofluoric acid, phosphoric acid, aqueous ammonia, aqueous hydrogen peroxide, an organic acid (e.g., citric acid, oxalic acid, etc.), an organic base (e.g., TMAH: tetramethylammonium hydroxide, etc.), a surfactant, and a preservative.

[0083] The rinse liquid nozzle 43b ejects rinse liquid toward the upper surface of the substrate W held by the spin chuck 41. The rinse liquid nozzle 43b is connected to a rinse liquid supply source 433b via a rinse liquid pipe 432b through which a rinse liquid valve 431b is inserted. When the rinse liquid valve 431b is opened, rinse liquid is supplied to the rinse liquid nozzle 43b through the rinse liquid pipe 432b and is ejected from the rinse liquid nozzle 43b. The rinse liquid valve 431b opens and closes according to instructions from the control unit 6. In other words, the timing of ejecting the rinse liquid from the rinse liquid nozzle 43b is controlled by the control unit 6. The rinse liquid is, for example, pure water (deionized water). However, the rinse liquid is not limited to pure water and may also be any of carbonated water, electrolytic ion water, hydrogen water, ozone water, and hydrochloric acid water with a diluted concentration (for example, about 10 to 100 ppm).

[0084] The IPA nozzle 43c ejects IPA (i.e., a liquid primarily composed of IPA) toward the upper surface of the substrate W held by the spin chuck 41. The IPA nozzle 43c is connected to the organic solvent recovery unit 5 via an IPA pipe 432c, through which an IPA valve 431c is inserted. When the IPA valve 431c is opened, IPA is supplied to the IPA nozzle 43c via the IPA pipe 432c, and IPA is ejected from the IPA nozzle 43c. The IPA valve 431c opens and closes based on instructions from the control unit 6. In other words, the timing of ejecting IPA from the IPA nozzle 43c is controlled by the control unit 6.

[0085] Alternatively, a nozzle movement mechanism may be connected to at least one of the chemical liquid nozzle 43a, the rinse liquid nozzle 43b, and the IPA nozzle 43c to move the nozzle between a processing position and a retreat position. The "processing position" is the position where the processing liquid ejected from the nozzles 43a, 43b, and 43c is supplied to the substrate W held by the spin chuck 41. The "retreat position" is a position where the nozzles 43a, 43b, and 43c are located outside (radially outward) of the periphery of the substrate W held by the spin chuck 41 when viewed from above. In this case, the nozzle movement mechanism moves the nozzles 43a, 43b, and 43c in response to instructions from the control unit 6. In other words, the positions of the nozzles 43a, 43b, and 43c are controlled by the control unit 6.

[0086] <2-2. Operation of Processing Unit>

[0087] An example of the operation of the processing unit 4 will be described. The operation performed in the processing unit 4 is performed under the control of the control unit 6 (i.e., the control unit 6 controls the chuck pin 412, the rotary motor 414, the cup lifting mechanism 425, the chemical valve 431a, the rinse liquid valve 431b, the IPA valve 431c, etc.).

[0088] When the substrate W is carried into the processing chamber 44 by the main transfer robot 3 , the spin chuck 41 holds the substrate W. Then, the spin chuck 41 starts to rotate.

[0089] In this state, the chemical liquid valve 431a is opened. In this way, the chemical liquid is sprayed from the chemical liquid nozzle 43a toward the upper surface of the substrate W held and rotated by the spin chuck 41. As a result, the chemical liquid is supplied to the entire area of ​​the upper surface of the substrate W, and the substrate W is treated with the chemical liquid (chemical liquid treatment process). For example, when hydrofluoric acid is used as the chemical liquid, foreign matter such as particles is removed from the substrate W. During the chemical liquid treatment process, the cup 42 is arranged in the upper position. Therefore, the chemical liquid scattered around the substrate W is caught by the cup 42. In other words, the chemical liquid scattered around the substrate W is caught by the inclined portion 422, guided downward by the guide portion 421, and collected in the liquid receiving portion 423. The chemical liquid caught by the cup 42 (i.e., the chemical liquid collected in the liquid receiving portion 423) is recovered through the cup-side recovery pipe for the chemical liquid (not shown).

[0090] At a specified time point after the start of the spraying of the chemical liquid, the chemical liquid valve 431a is closed. In this way, the spraying of the chemical liquid from the chemical liquid nozzle 43a is stopped. Next, the rinsing liquid valve 431b is opened. In this way, the rinsing liquid is sprayed from the rinsing liquid nozzle 43b toward the upper surface of the substrate W held and rotated by the spin chuck 41. Thus, the rinsing liquid is supplied to the entire area of ​​the upper surface of the substrate W, and the chemical liquid attached to the substrate W is washed away by the rinsing liquid (rinsing treatment process). During the rinsing treatment process, the support cup 42 is also arranged in the upper position. Therefore, the chemical liquid and the rinsing liquid scattered around the substrate W are caught by the support cup 42. The chemical liquid and the rinsing liquid caught by the support cup 42 are recovered through the support cup side recovery pipe f for the chemical liquid (not shown in the figure).

[0091] At a specified time point after the start of the rinsing liquid spraying, the rinsing liquid valve 431b is closed. In this way, the spraying of the rinsing liquid from the rinsing liquid nozzle 43b is stopped. Next, the IPA valve 431c is opened. In this way, IPA is sprayed from the IPA nozzle 43c toward the upper surface of the substrate W held and rotated by the spin chuck 41. Thus, IPA is supplied to the entire area of ​​the upper surface of the substrate W, and the rinsing liquid attached to the substrate W is replaced by IPA (IPA supply process). During the IPA supply process, the support cup 42 is also arranged in the upper position. Therefore, the rinsing liquid and IPA scattered around the substrate W are caught by the support cup 42. The rinsing liquid and IPA caught by the support cup 42 are recovered through the support cup side recovery pipe 424 for IPA.

[0092] At a point in time when a specified time has passed since the start of IPA supply, the IPA valve 431c is closed. This stops the discharge of IPA from the IPA nozzle 43c. At this stage, the rinse liquid on the substrate W is completely replaced by IPA, forming a liquid film of IPA covering the entire area of ​​the upper surface of the substrate W. Next, the spin chuck 41 starts to rotate at high speed. As a result, the substrate W is rotated at high speed, so that the IPA on the substrate W is thrown to the periphery of the substrate W by centrifugal force (spin drying process). While the substrate W is being rotated at high speed, the cup 42 is also arranged in the upper position. Therefore, the IPA scattered around the substrate W is caught by the cup 42. The IPA caught by the cup 42 is recovered through the cup-side recovery pipe 424 for IPA.

[0093] After a predetermined time has passed since the start of high-speed rotation of the spin chuck 41 , the spin chuck 41 is stopped. At this stage, the IPA is removed from the substrate W, drying the substrate W. The dried substrate W is carried out of the processing chamber 44 by the main transfer robot 3 .

[0094] The above completes a series of processes for one substrate W. The processing unit 4 processes a plurality of substrates W one by one in sequence by repeating the above series of operations.

[0095] <3. Overview of the Organic Solvent Recovery Unit 5f (Organic Solvent Recovery Device)>

[0096] Reference Figure 3 The structure of the organic solvent recovery unit 5 will be described. Figure 3 1 is a diagram schematically showing a first example of the substrate processing apparatus 100 according to the first embodiment. Hereinafter, the outline of the organic solvent recovery unit 5 will be described first, and then each component of the organic solvent recovery unit 5 will be described in detail.

[0097] The organic solvent recovery unit 5 includes a switching unit 50 and a first dehydrator 60 . Figure 3 The switching unit 50 shown switches the supply destination of the mixed liquid of organic solvent and water discharged from each processing unit 4 between the first dehydrator 60 and the outside. The organic solvent is, for example, an organic solvent with higher volatility than water or an organic solvent with lower surface tension than water. A specific example is IPA (isopropyl alcohol). The outside is, for example, the wastewater treatment unit of factory equipment.

[0098] The first dehydrator 60 includes a first membrane separator 62. The mixed liquid discharged from the treatment unit 4 can flow into the first membrane separator 62. The first membrane separator 62 separates water from the mixed liquid, thereby increasing the concentration of the organic solvent in the mixed liquid (hereinafter referred to as solvent concentration).

[0099] like Figure 3As shown, the first membrane separator 62 includes a first mixing path 62a, a first water path 62b, and a first separation membrane 62c. A mixed liquid flows into the first mixing path 62a. The first separation membrane 62c separates the first mixing path 62a from the first water path 62b. The first separation membrane 62c allows water in the mixed liquid to pass through while largely blocking organic solvents. A portion of the water in the mixed liquid flowing into the first mixing path 62a passes through the first separation membrane 62c and flows into the first water path 62b. As a result, the solvent concentration of the mixed liquid passing through the first mixing path 62a is higher than the solvent concentration of the mixed liquid immediately before entering the first mixing path 62a. The first dehydrator 60 uses the first membrane separator 62 to raise the solvent concentration of the mixed liquid to above a specified reuse threshold value. The reuse threshold value is the solvent concentration that can be used in the treatment unit 4 and is, for example, set in advance. Hereinafter, the mixed liquid whose solvent concentration has been raised to above the reuse threshold value is also referred to as reused liquid. It can also be said that the first dehydrator 60 separates water from the mixed liquid to produce a reused liquid.

[0100] The upstream end of a liquid supply pipe 85 is connected to the first dehydrator 60, and the downstream end of the liquid supply pipe 85 is connected to a supply tank Tk3 for supplying the liquid to the processing unit 4. The first dehydrator 60 supplies the reused liquid to the supply tank Tk3 via the liquid supply pipe 85. The mixed liquid in the supply tank Tk3 is then supplied to the processing unit 4 again.

[0101] In addition, the first separation membrane 62c has an applicable range of solvent concentration. That is, the first separation membrane 62c can appropriately separate water from a mixed liquid having a solvent concentration within the applicable range. On the other hand, if a mixed liquid having a solvent concentration less than the lower limit of the applicable range flows into the first membrane separator 62, the first separation membrane 62c may cause adverse reactions. For example, the first membrane separator 62 may not be able to fully separate water from the mixed liquid. Alternatively, if the proportion of water molecules passing through the first separation membrane 62c exceeds the allowable value, the crystal structure constituting the first separation membrane 62c may partially dissolve, resulting in a significant shortening of the service life of the first separation membrane 62c. hereinafter, the lower limit of the applicable range of solvent concentration is referred to as the lower limit of concentration. As an example, the lower limit of concentration of the first separation membrane 62c is 50 wt%.

[0102] Therefore, the control unit 6 controls the switching unit 50 based on the solvent concentration of the mixed liquid discharged from the processing unit 4. The method for obtaining the solvent concentration of the mixed liquid will be described in detail below. When the solvent concentration of the mixed liquid is a first value that is greater than the lower limit value of the concentration of the first separation membrane 62c, the control unit 6 causes the switching unit 50 to supply the mixed liquid to the first dehydrator 60. The first dehydrator 60 separates water from the mixed liquid and increases the solvent concentration of the mixed liquid. On the other hand, when the solvent concentration of the mixed liquid is a second value that is less than the lower limit value of the concentration of the first separation membrane 62c, the control unit 6 causes the switching unit 50 to supply the mixed liquid to other parts (here, the outside of the drainage treatment part of the factory equipment, etc.).

[0103] As described above, when the solvent concentration of the mixed liquid discharged from the processing unit 4 exceeds the lower concentration limit of the first separation membrane 62c, the organic solvent recovery unit 5 uses the first dehydrator 60 to increase the solvent concentration of the mixed liquid to produce reused liquid. This reused liquid is then supplied to the processing unit 4 again. In other words, the substrate processing apparatus 100 reuses the organic solvent in the mixed liquid discharged from the processing unit 4. This reduces the amount of waste organic solvent and enables more efficient use of the organic solvent. In other words, the organic solvent recovery unit 5 contributes to liquid conservation.

[0104] Furthermore, the first dehydrator 60 uses a first membrane separator 62 to separate water from the mixed liquid. Membrane separation has a higher energy efficiency than separation methods such as distillation, and therefore the first dehydrator 60 is highly efficient. In other words, the first dehydrator 60 can more efficiently increase the solvent concentration in the mixed liquid.

[0105] Conversely, when the solvent concentration of the mixed liquid from the treatment unit 4 is less than the lower concentration limit of the first separation membrane 62c, the mixed liquid is not supplied to the first dehydrator 60. This prevents the mixed liquid with a relatively low solvent concentration from passing through the first separation membrane 62c and causing problems with the first separation membrane 62c. In other words, the reliability of the organic solvent recovery unit 5 can be improved.

[0106] As described above, the organic solvent recovery unit 5 can separate water from the mixed liquid with high reliability and high efficiency to increase the organic solvent concentration of the mixed liquid.

[0107] Furthermore, the switching unit 50 can also be said to switch between the first state and the second state, which will be described below. The first state is a state in which the solvent concentration of the mixed liquid discharged from the processing unit 4 is increased by the first dehydrator 60. Here, the first state is a state in which the switching unit 50 supplies the mixed liquid from the processing unit 4 to the first dehydrator 60. The second state is a state in which the mixed liquid discharged from the processing unit 4 is supplied to another portion other than the first dehydrator 60. In this example, the other portion can also be said to be the outside (for example, the drainage processing unit), or it can be said to be a discharge pipe through which the mixed liquid flows to the outside.

[0108] <3-1. Specific example of the organic solvent recovery unit 5>

[0109] <3-1-1. Switching Unit 50>

[0110] exist Figure 3 In the example of , the switching unit 50 includes a recovery pipe 51 and a switching valve unit 520. Figure 3 In the example of , the recovery pipe 51 includes a first dehydration pipe 511, other pipes 512, and a common recovery pipe 510. Figure 3 In the example of , a plurality of common recovery pipes 510 are provided corresponding to a plurality of processing units 4. Figure 3 In this example, multiple common recovery pipes 510 are provided one-to-one with multiple processing units 4. The upstream end of each common recovery pipe 510 is connected to the corresponding processing unit 4 (specifically, the socket 42). Common recovery pipe 510 is equivalent to the socket-side recovery pipe 424 described above. The mixed liquid from the processing unit 4 flows through common recovery pipe 510.

[0111] The downstream end of each common recovery pipe 510 is connected to the upstream end of the first dehydration pipe 511 and the upstream end of the other pipes 512. The downstream end of the first dehydration pipe 511 is connected to the first dehydrator 60, and the downstream end of the other pipes 512 is connected to the outside. Figure 3 In the example shown, the first dehydration piping 511 includes a first common piping 513 and a plurality of first branch pipes 514. The plurality of first branch pipes 514 are provided one-to-one with the plurality of common recovery piping 510. The upstream ends of the first branch pipes 514 are connected to the downstream ends of the corresponding common recovery piping 510, and the downstream ends of the first branch pipes 514 are connected to the first common piping 513. The downstream end of the first common piping 513 corresponds to the downstream end of the first dehydration piping 511.

[0112] The other pipes 512 are connected to the downstream ends of the common recovery pipes 510. Figure 3In the example shown in FIG. 5 , the other portion piping 512 includes a common other portion piping 515 and a plurality of branch other portion pipings 516. The plurality of branch other portion pipings 516 are provided one-to-one with the plurality of common recovery pipings 510. The upstream ends of the branch other portion pipings 516 are connected to the downstream ends of the corresponding common recovery pipings 510, and the downstream ends of the branch other portion pipings 516 are connected to the common other portion piping 515. The downstream end of the common other portion piping 515 corresponds to the downstream end of the other portion piping 512.

[0113] exist Figure 3 In the example, the switching valve section 520 includes a switching valve 521 and a switching valve 522. The switching valve section 520 switches the state in which the common recovery pipe 510 is connected to the first dehydrator 60 (i.e., the first state) and the state in which the common recovery pipe 510 is connected to the outside (i.e., the second state). Figure 3 In the example, the plurality of switching valve sections 520 are provided one to one with the plurality of processing units 4. Figure 3 In the example shown in FIG, a plurality of switching valves 521 are provided one-to-one with a plurality of processing units 4, and a plurality of switching valves 522 are provided one-to-one with a plurality of processing units 4. Each switching valve 521 is inserted into a corresponding first branch pipe 514, and each switching valve 522 is inserted into a corresponding other branch pipe 516.

[0114] The following describes the operation of the switching valve unit 520 corresponding to a single treatment unit 4. When the controller 6 closes the switching valve 521 and opens the switching valve 522, the mixed liquid from the treatment unit 4 sequentially flows through the common recovery pipe 510 and the other pipes 512 before being supplied to the outside. In other words, the switching valve unit 520 is in the second state. When the controller 6 opens the switching valve 521 and closes the switching valve 522, the mixed liquid from the treatment unit 4 sequentially flows through the common recovery pipe 510 and the first dehydration pipe 511 before being supplied to the first dehydrator 60. In other words, the switching valve unit 520 is in the first state.

[0115] <3-1-2. First Dehydrator 60>

[0116] Figure 4 This is a diagram schematically showing an example of a specific structure of the first dehydrator 60 of the organic solvent recovery unit 5. The first dehydrator 60 of the organic solvent recovery unit 5 can be housed in the first housing box 50a (see Figure 1 As an example, the first storage box 50a is arranged outside the outer wall 100a of the substrate processing apparatus 100 (for example, below the clean room where the substrate processing apparatus 100 is installed (for example, downstairs)).

[0117] exist Figure 4 In the example of , the first dehydrator 60 includes a first circulation unit 61 . Figure 4 In the embodiment, the downstream end portion of the first dehydration pipe 511 is connected to the concentration tank Tk1.

[0118] (a) Concentration tank Tk1

[0119] The mixed liquid is supplied from the treatment unit 4 to the concentration tank Tk1 through the first dehydration pipe 511. The concentration tank Tk1 stores the mixed liquid. As described above, the solvent concentration of the mixed liquid is equal to or higher than the lower limit of the concentration of the first separation membrane 62c.

[0120] (b) First circulation unit 61

[0121] The first circulation section 61 includes a first membrane separator 62 and a first circulation pipe 63. The first circulation pipe 63 is connected to the concentration tank Tk1. The first circulation pipe 63 is a pipe for returning the mixed liquid from the concentration tank Tk1 to the concentration tank Tk1. In other words, the first circulation pipe 63 forms a first circulation path for circulating the mixed liquid stored in the concentration tank Tk1 so that it flows out of the concentration tank Tk1 and returns to the concentration tank Tk1 again. Figure 4 In the example of , the upstream end of the first circulation pipe 63 is connected to the bottom of the concentration tank Tk1 , and the downstream end of the first circulation pipe 63 is connected to the upper part of the concentration tank Tk1 .

[0122] The first membrane separator 62 is disposed in the first circulation piping 63. Specifically, the first mixing path 62a of the first membrane separator 62 is inserted into the first circulation piping 63, forming part of the first circulation path of the first circulation section 61. Therefore, the mixed liquid passes through the first mixing path 62a. A portion of the water in the mixed liquid flowing into the first mixing path 62a passes through the first separation membrane 62c and flows into the first water path 62b. Due to this dehydration, the solvent concentration of the mixed liquid immediately after the first membrane separator 62 in the first circulation piping 63 is higher than the solvent concentration of the mixed liquid immediately before the first membrane separator 62. Because the first circulation section 61 circulates the mixed liquid through the first circulation piping 63, the mixed liquid continuously flows into the first membrane separator 62. Therefore, the first membrane separator 62 continuously separates water from the mixed liquid. As a result, the solvent concentration of the circulating mixed liquid increases over time. Hereinafter, the liquid separated from the mixed liquid by the first membrane separator 62 is also referred to as separated liquid. The separation liquid is almost water.

[0123] The first separation membrane 62c can be a zeolite membrane, an organic separation membrane or a CNT (carbon nanotube) separation membrane. For example, the zeolite membrane has a tetrahedral structure (SiO4). 4- and (AlO4) 5-The crystal structure obtained by connecting with each other. Examples of organic separation membranes are organic membranes of polyvinyl alcohol, chitosan, and polyimide. Examples of CNT separation membranes are membranes obtained by adding carbon nanotubes to membranes of polyamide, etc. Alternatively, a two-dimensional material can be used as the material for the first separation membrane 62c. A two-dimensional material is a material composed of one layer of atoms, such as molybdenum sulfide (MoS2), or a composite atomic layer compound formed by a pre-transition metal (titanium or vanadium, etc.) and a light element (carbon or nitrogen). Alternatively, MOF (Metal Organic Frameworks) materials or carbon materials (for example, graphene or graphene oxide) can be used as the material for the first separation membrane 62c. Here, a zeolite membrane is used as the first separation membrane 62c.

[0124] The upstream end of the separation discharge pipe 66 is connected to the first water path 62b. The separated liquid is discharged to the outside (for example, the drainage treatment part of the factory equipment) through the separation discharge pipe 66. A pressure reducing pump for reducing the pressure of the first water path 62b may also be provided in the separation discharge pipe 66. Figure 4 As shown, a discharge valve 67 is inserted through the separation discharge pipe 66 .

[0125] exist Figure 4 In the example, the first circulation section 61 includes, in addition to the first membrane separator 62 and the first circulation pipe 63 , a pump 64 as an example of a liquid feeding section, a first switching valve 651 , and a second switching valve 652 .

[0126] A pump 64 is inserted into the first circulation pipe 63. For example, the pump 64 is installed upstream of the first membrane separator 62. A first switching valve 651 and a second switching valve 652 are inserted into the first circulation pipe 63. The first switching valve 651 is installed downstream of the first membrane separator 62. The second switching valve 652 is installed upstream of the pump 64.

[0127] Various sensors may be inserted into the first circulation piping 63. For example, a concentration sensor Sn63 for measuring the concentration of an organic solvent (here, for example, IPA) in the fluid flowing through the first circulation piping 63, a flow sensor (flow meter) Sn64 for measuring the flow rate of the fluid flowing through the first circulation piping 63, and a pressure sensor Sn61 for measuring the pressure of the fluid flowing through the first circulation piping 63 are inserted into the first circulation piping 63. The concentration sensor Sn63 is, for example, inserted downstream of the first membrane separator 62. The flow sensor Sn64 is, for example, inserted upstream of the pump 64. The pressure sensor Sn61 is, for example, inserted downstream of the pump 64 and upstream of the first membrane separator 62.

[0128] <3-1-3. Recyclable Liquid Supply Unit 89>

[0129] exist Figure 4 In the example of , the first dehydrator 60 also includes a reused liquid supply unit 89. The reused liquid supply unit 89 supplies the reused liquid to the supply tank Tk3. The reused liquid supply unit 89 includes a liquid supply pipe 85, a liquid supply valve 86, and a pump 64 as an example of a liquid supply unit.

[0130] exist Figure 3 and Figure 4 In the example, the supply tank Tk3 is connected to the first circulation pipe 63 via the liquid supply pipe 85. That is, the downstream end of the liquid supply pipe 85 is connected to the supply tank Tk3, and the upstream end of the liquid supply pipe 85 is connected to the first circulation pipe 63. Specifically, the upstream end of the liquid supply pipe 85 is connected to the first circulation pipe 63 at a position between the pump 64 and the first switching valve 651. As an example, the upstream end of the liquid supply pipe 85 is connected to the first circulation pipe 63 at a position between the pump 64 and the first membrane separator 62. A liquid supply valve 86 is inserted in the liquid supply pipe 85. In addition, the upstream end of the liquid supply pipe 85 does not necessarily have to be connected to the first circulation pipe 63, and can also be connected to the concentration tank Tk1. In this case, a pump different from the pump 64 is provided in the liquid supply pipe 85.

[0131] <New Liquid Supply>

[0132] like Figure 3 As shown, the supply tank Tk3 is connected to a fresh liquid supply source 403 via a fresh liquid pipe 401. Specifically, the downstream end of the fresh liquid pipe 401 is connected to the supply tank Tk3, and the upstream end of the fresh liquid pipe 401 is connected to the fresh liquid supply source 403. The fresh liquid supply source 403 is a source of unused organic solvent (e.g., IPA with a concentration of 99.8 wt% or greater) that has never been supplied to the substrate W. A fresh liquid valve 402 is inserted through the fresh liquid pipe 401.

[0133] The supply tank Tk3 is connected to the IPA nozzle 43c via the third liquid supply pipe 404. Specifically, the supply tank Tk3 is connected to one end of the third liquid supply pipe 404, and the IPA nozzle 43c (specifically, the IPA pipe 432c connected to the IPA nozzle 43c) is connected to the other end of the third liquid supply pipe 404. For example, the third liquid supply pipe 404 is connected to the IPA nozzle 43c included in each of the multiple processing units 4 belonging to the same tower.

[0134] A pump (supply-side liquid supply pump) 405 is inserted through the third liquid supply pipe 404. A filter 407 is inserted through the third liquid supply pipe 404 downstream of the supply-side liquid supply pump 405. A thermostat 406 is inserted through the third liquid supply pipe 404 upstream of the filter 407 and downstream of the supply-side liquid supply pump 405.

[0135] Various sensors are inserted into the third liquid supply pipe 404. For example, a temperature sensor Sn41 is inserted into the third liquid supply pipe 404 to measure the temperature of the fluid flowing through the third liquid supply pipe 404. The temperature sensor Sn41 is inserted, for example, upstream of the filter 407 and downstream of the temperature regulator 406. The temperature regulator 406 adjusts the temperature of the reuse liquid supplied to the processing unit 4 to a specified temperature range corresponding to the processing of the substrate W.

[0136] <3-2. Example of Operation of the Organic Solvent Recovery Unit 5>

[0137] Figure 5 This is a flowchart showing an example of the operation of the organic solvent recovery unit 5 according to the first embodiment. First, the control unit 6 obtains the solvent concentration of the mixed liquid discharged from the treatment unit 4 (step S1: concentration acquisition step). A specific example of the method for obtaining the solvent concentration will be described in detail below.

[0138] Next, the control unit 6 determines whether the solvent concentration is greater than or equal to a predetermined switching reference value (step S2: concentration determination step). The switching reference value is, for example, pre-set to a value greater than or equal to the lower limit concentration value of the first separation membrane 62c (e.g., 50 wt%). The switching reference value can be, for example, a value closer to the lower limit concentration value of the first separation membrane 62c (e.g., 60 wt%) than the reuse reference value (e.g., 99 wt%).

[0139] When the solvent concentration of the mixed liquid is above the switching reference value, the first dehydrator 60 separates water from the mixed liquid discharged from the treatment unit 4, thereby increasing the solvent concentration of the mixed liquid (step S3: first dehydrator process). Specifically, the control unit 6 causes the switching unit 50 to select the first state. As an example, the control unit 6 opens the switching valve 521 and closes the switching valve 522. In other words, if the solvent concentration of the mixed liquid is above the switching reference value, the highly efficient first membrane separator 62 can be used. Therefore, the switching unit 50 supplies the mixed liquid from the treatment unit 4 to the first dehydrator 60. This mixed liquid is stored in the concentration tank Tk1. In addition, when a buffer tank is provided, the mixed liquid from the treatment unit 4 is temporarily stored in the buffer tank, and the mixed liquid is supplied from the buffer tank to the concentration tank Tk1.

[0140] The first circulation unit 61 circulates the mixed liquid through the first circulation piping 63. For example, the controller 6 opens the first switching valve 651, the second switching valve 652, and the discharge valve 67, and activates the pump 64. This causes the mixed liquid to circulate through the first circulation path, which includes the concentration tank Tk1 and the first circulation piping 63. Through this circulation, the mixed liquid continuously passes through the first membrane separator 62. Consequently, the first membrane separator 62 continuously separates the separated liquid from the mixed liquid, and the separated liquid continuously is discharged to the outside through the separation discharge piping 66. Consequently, the solvent concentration of the circulating mixed liquid increases over time.

[0141] The control unit 6 circulates the mixed liquid in the first circulation unit 61 until the solvent concentration of the circulating mixed liquid reaches or exceeds a specified reuse reference value. The reuse reference value can be, for example, 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, 95 wt% or more, or 99 wt% or more. For example, the control unit 6 can compare the solvent concentration measured by the concentration sensor Sn63 with the reuse reference value and stop the circulation of the first circulation unit 61 when the solvent concentration reaches or exceeds the reuse reference value. Specifically, the control unit 6 closes the first switching valve 651, the second switching valve 652, and the discharge valve 67, and stops the pump 64.

[0142] Through this circulation, a mixed liquid with an increased solvent concentration (i.e., recycled liquid) is stored in the concentration tank Tk1. Furthermore, the controller 6 can also stop the circulation in the first circulation unit 61 by triggering a predetermined first dehydration time. The first dehydration time is, for example, set in advance to a time period that is longer than the time required for the solvent concentration to reach a reuse reference value or higher. The first dehydration time can be set, for example, to several tens of minutes or more or several hours or more.

[0143] Next, the reused liquid supply unit 89 supplies the reused liquid to the supply tank Tk3 (Step S4: Supply Process). Specifically, the control unit 6 opens the liquid supply valve 86 and activates the pump 64. As a result, the reused liquid in the concentration tank Tk1 is supplied to at least the supply tank Tk3 via the liquid supply pipe 85.

[0144] On the other hand, in step S2, if the solvent concentration of the mixed liquid is less than the switching reference value, the mixed liquid is supplied to another portion (here, an external portion such as the wastewater treatment unit of the factory equipment) (step S5: other portion process). Specifically, the control unit 6 causes the switching unit 50 to select the second state. As an example, the control unit 6 closes the switching valve 521 and opens the switching valve 522. As a result, the mixed liquid from the processing unit 4 is supplied to the outside through the other portion piping 512.

[0145] As described above, when the solvent concentration of the mixed liquid from the treatment unit 4 is equal to or greater than the switching reference value, the first dehydrator 60 increases the solvent concentration of the mixed liquid (step S3). Therefore, the first dehydrator 60 can appropriately increase the solvent concentration of the mixed liquid using the highly efficient first membrane separator 62.

[0146] On the other hand, when the solvent concentration of the mixed liquid from the treatment unit 4 is less than the switching reference value, the organic solvent recovery unit 5 supplies the mixed liquid from the treatment unit 4 to another unit (step S5). In other words, if the solvent concentration of the mixed liquid is less than the switching reference value, the first membrane separator 62 may not be usable. Therefore, the organic solvent recovery unit 5 discharges the mixed liquid to the outside. This protects the first membrane separator 62 and improves the reliability of the organic solvent recovery unit 5.

[0147] Furthermore, in the example described above, the first dehydrator 60 increases the solvent concentration of the mixed liquid by repeatedly flowing the mixed liquid into the first membrane separator 62 through circulation achieved by the first circulation section 61. Furthermore, the larger the size of the first membrane separator 62 (i.e., the size of the first separation membrane 62c), the greater the increase in solvent concentration achieved by the first membrane separator 62. Therefore, if the first dehydrator 60 does not circulate the mixed liquid, the size of the first membrane separator 62 must be increased to ensure the increase in solvent concentration. In contrast, in the specific example described above, the first dehydrator 60 increases the solvent concentration of the mixed liquid through circulation achieved by the first circulation section 61. Therefore, the size of the first membrane separator 62 (i.e., the size of the first separation membrane 62c) required to raise the solvent concentration of the mixed liquid to the reuse reference value can be reduced.

[0148] <3-2-1. Method for Obtaining Solvent Concentration>

[0149] <3-2-1-1. Calculation of solvent concentration based on formulation information>

[0150] Next, an example of a method for obtaining the solvent concentration of the mixed liquid discharged from the processing unit 4 will be described. The solvent concentration of the mixed liquid discharged from the processing unit 4 depends on the processing content of the substrate W in the processing unit 4. For example, the processing unit 4 supplies pure water to the substrate W and then supplies an organic solvent to the substrate W. During this process, if the processing unit 4 supplies pure water to the substrate W at a high flow rate and for a long time, the solvent concentration of the mixed liquid discharged from the processing unit 4 will be relatively low. On the other hand, if the processing unit 4 supplies an organic solvent to the substrate W at a high flow rate and for a long time, the solvent concentration of the mixed liquid discharged from the processing unit 4 will be relatively high. In this way, the solvent concentration of the mixed liquid discharged from the processing unit 4 depends on the processing content.

[0151] Figure 6: is a diagram schematically showing an example of the processing unit 4 of the first embodiment. Figure 6 As shown, the control unit 6 is connected to a storage unit 603. The storage unit 603 is, for example, a nonvolatile storage unit, and specifically, a memory or a hard disk. The storage unit 603 stores recipe information D1 that specifies the processing details for the substrate W. The recipe information D1 includes, for example, various information such as the nozzle used in each process, the flow rate of the processing liquid, the discharge time of the processing liquid, and the rotation speed of the substrate W.

[0152] In addition, if Figure 6 As shown, the processing unit 4 may include a plurality of cups 42. Figure 6 In the example of FIG, a plurality of support cups 42 are shown, including support cup 42A, support cup 42B, and support cup 42C. Support cup 42A, support cup 42B, and support cup 42C are arranged concentrically. Figure 6 In the example, the support cup 42A is located at the outermost side, the support cup 42C is located at the innermost side, and the support cup 42B is located between the support cup 42A and the support cup 42C.

[0153] The cup lifting mechanism 425 raises and lowers each cup 42. For example, the cup lifting mechanism 425 raises the cup 42A to the upper position, and lowers the cups 42B and 42C to the lower position. In this state, the processing liquid scattered from the periphery of the substrate W is caught by the cup 42A. In addition, the cup lifting mechanism 425 raises the cups 42A and 42B to the upper position, and lowers the cup 42C to the lower position. In this state, the processing liquid scattered from the periphery of the substrate W is caught by the cup 42B. In addition, the cup lifting mechanism 425 raises the cups 42A, 42B, and 42C to the upper position. In this state, the processing liquid scattered from the periphery of the substrate W is caught by the cup 42C.

[0154] exist Figure 6 In the example shown in FIG. 5 , the processing liquid received by the socket 42C flows into the recovery pipe 51. The processing liquid received by the socket 42A flows into another recovery pipe (not shown), and the processing liquid received by the socket 42B flows into another recovery pipe (not shown).

[0155] This processing unit 4 can change the cup 42 that receives the processing liquid according to the type of processing liquid. For example, when pure water is supplied to the substrate W, the cup lifting mechanism 425 only places the cup 42A in the upper position. In this case, the pure water is received by the cup 42A. In addition, when an organic solvent is supplied to the substrate W, the cup lifting mechanism 425 changes from placing the cup 42A in the upper position to placing the cup 42C in the upper position. In this case, the organic solvent is received by the cup 42C and flows into the recovery pipe 51. That is, in this example, the cup 42C is a cup for the organic solvent, and the recovery pipe 51 is a recovery pipe for the organic solvent. In this way, the processing unit 4 can switch the cup between the cup 42A and the cup 42C according to the type of processing liquid. Information indicating the position of the cup 42 in each of these processes is also included in the recipe information D1.

[0156] like Figure 6 As shown, the control unit 6 includes a concentration estimating unit 601. The concentration estimating unit 601 reads the recipe information D1 from the storage unit 603. Based on the recipe information D1, the concentration estimating unit 601 calculates the solvent concentration of the mixed liquid discharged from the processing unit 4 (i.e., the mixed liquid flowing into the recovery pipe 51). Table 1 schematically shows a first example of the recipe information D1.

[0157] [Table 1]

[0158] Recipe Information

[0159]

[0160] Table 1 shows some of the steps involved in processing a substrate W. In Table 1, recipe information D1 includes the number of each step, the rotational speed of the substrate W in each step, the time required for each step, the flow rate of the processing liquid in each step, the type of processing liquid in each step, and the retainer cup used in each step. The retainer cup used is information indicating the position of the retainer cup 42.

[0161] Figure 7 This is a diagram schematically showing an example of the state of the processing unit 4 in each step of Table 1. Figure 7 (a) to Figure 7 (f) shows an example of the state of the processing unit 4 in the 30th step to the 35th step in Table 1.

[0162] In the 30th step of Table 1, the spin chuck 41 rotates the substrate W at 100 rpm for 2 seconds, and the rinse liquid nozzle 43b sprays pure water at 2000 mL (milliliter) / min toward the substrate W. In addition, the holder 42A is used in the 30th step. That is, Figure 7 As shown in (a), in the 30th step, pure water scattered from the periphery of the substrate W is caught by the retainer 42A.

[0163] In the 31st step, the spin chuck 41 rotates the substrate W at 10 rpm for 1 second. In the 31st step, no processing liquid is supplied to the substrate W. In the 31st step, the rotation speed of the substrate W is relatively low. Figure 7 As shown in (b), pure water is maintained on the main surface of the substrate W. This process is also called a blanketing process. Although not shown in Table 1, the following process can be performed between steps 30 and 31: the rinse liquid nozzle 43b sprays pure water at 2000 mL / min while the chuck 41 is rotated and the rotation speed is gradually reduced to 10 rpm. The lower the rotation speed of the substrate W after the pure water spraying stops, the thicker the pure water film on the main surface of the substrate W during the blanketing process.

[0164] In the 32nd step, the spin chuck 41 rotates the substrate W at 10 rpm for 1 second, and the cup lifting mechanism 425 switches the cup to be used from the cup 42A to the cup 42C (see FIG. Figure 7 (c)).

[0165] In the 33rd step, the spin chuck 41 rotates the substrate W at 10 rpm for 4 seconds, and the IPA nozzle 43c sprays an organic solvent at 100 mL / min toward the main surface of the substrate W. The organic solvent is, for example, IPA. Figure 7 As shown in (d), in the thirty-third step, the processing liquid (pure water and organic solvent) can flow down from the periphery of the substrate W. In this case, the processing liquid is received by the retainer cup 42C and flows into the upstream end of the recovery pipe 51.

[0166] In the 34th step, the spin chuck 41 rotates the substrate W at 1000 rpm for 3 seconds, and the IPA nozzle 43c sprays the organic solvent toward the main surface of the substrate W at 100 mL / min. Figure 7 As shown in (e), the organic solvent that has landed on the main surface of substrate W flows radially outward and, along with the pure water, scatters outward from the periphery of substrate W. The resulting mixture of organic solvent and pure water is collected by retainer cup 42C and then flows into the upstream end of recovery pipe 51. Through steps 33 and 34, the pure water on the main surface of substrate W is replaced with the organic solvent.

[0167] In the 35th step, the spin chuck 41 rotates the substrate W at 1000 rpm for 2 seconds. In the 35th step, no processing liquid is supplied to the substrate W. Figure 7 As shown in (f), in the 35th step, a portion of the organic solvent on the main surface of the substrate W is scattered from the periphery of the substrate W. In addition, a portion of the remaining organic solvent evaporates. As a result, the main surface of the substrate W is dried.

[0168] As described above, the cup 42C is raised to the upper position in the 31st step (see also Figure 7(c)). Therefore, the cup 42C can receive the process liquid (pure water and organic solvent, i.e., a mixed liquid) during steps 31 through 35. This process liquid flows into the upstream end of the recovery pipe 51. Hereinafter, the period from steps 31 through 35 will also be referred to as the discharge period. The discharge period is the period during which the cup 42C can receive the process liquid.

[0169] The solvent concentration (average value) of the mixed liquid flowing into the recovery pipe 51 during the discharge period can be calculated based on the pure water discharge rate and the solvent discharge rate, which will be described below. The pure water discharge rate is the total amount of pure water flowing into the recovery pipe 51 during the discharge period, that is, the total amount of pure water received by the socket 42C during the discharge period. The solvent discharge rate is the total amount of organic solvent flowing into the recovery pipe 51 during the discharge period, that is, the total amount of organic solvent received by the socket 42C during the discharge period.

[0170] First, the pure water discharge amount is described. In the example of Table 1, pure water is not supplied during the discharge period (steps 31 to 35). Therefore, the pure water discharge amount is the amount of pure water present on the main surface of the substrate W at the start time of step 31 (see also Figure 7 (c)). Hereinafter, this amount of pure water will be referred to as the pure water film amount. The thickness of the pure water film on the main surface of substrate W depends on the rotational speed of substrate W at the start of step 31. Therefore, the pure water film amount depends on this rotational speed. Furthermore, the start of step 31 can also be considered the time when the switch from retainer cup 42A to retainer cup 42C begins.

[0171] Figure 8 Graphs are examples of distances between various positions on the substrate W and the center of the substrate W, and thicknesses of the pure water film at various positions. In other words, each graph represents the profile of the pure water surface. Figure 8 Graphs G1 to G4 are shown for different rotational speeds of the substrate W. Graph G1 corresponds to the lowest rotational speed, 10 rpm. Graph G2 corresponds to the second lowest rotational speed, 50 rpm. Graph G3 corresponds to the third lowest rotational speed, 100 rpm. Graph G4 corresponds to the highest rotational speed, 200 rpm. Graphs G1 to G4 can be obtained through simulation or experimentation.

[0172] The amount of pure water present on the main surface of the substrate W (pure water film amount) can be obtained by integrating the thickness of the liquid film in each graph. Therefore, the correspondence between the rotation speed of the substrate W and the pure water film amount can be obtained in advance. Correspondence information D2 indicating this correspondence is stored in the storage unit 603. (See also Figure 6 ) The rotation speed at the start time of the 31st step is included in the recipe information D1. Therefore, the pure water film amount can be obtained based on the rotation speed and the correspondence relationship information D2.

[0173] Furthermore, this graph may also be based on the pure water flow rate in the 30th step before the coating treatment. Therefore, a graph may be previously calculated for each flow rate through simulation or experimentation, and the pure water film amount may be calculated based on this graph. In this case, the correspondence information D2 includes a correspondence between combinations of rotational speed and pure water flow rate and the pure water film amount.

[0174] Next, the solvent discharge amount is explained. For simplicity, the solvent discharge amount can be considered to be equal to the amount of organic solvent discharged onto the substrate W during the discharge period. The amount of organic solvent discharged during the discharge period can be calculated by taking the time integral of the organic solvent flow rate. In other words, the solvent discharge amount can be calculated by summing the product of the organic solvent flow rate and the required time (discharge time) for each process. In the example of Table 1, the solvent discharge amount is represented by 100×(4+3) / 60. In addition, since the organic solvent evaporates, the time integral value can be reduced by a specified ratio to account for this evaporation.

[0175] Table 2 schematically shows a second example of the recipe information D1.

[0176] [Table 2]

[0177] Recipe Information

[0178]

[0179] Table 2 also shows some steps in the processing of the substrate W. Figure 9 This is a diagram schematically showing an example of the state of the processing unit 4 in each step of Table 2. Figure 9 (a) to Figure 9 (e) shows an example of the state of the processing unit 4 in the 30th step to the 34th step in Table 2.

[0180] In the 30th step of Table 2, the spin chuck 41 rotates the substrate W at 1500 rpm for 4 seconds, and the rinse liquid nozzle 43b sprays pure water at 2000 mL / min toward the substrate W. In addition, the holder 42A is used in the 30th step. That is, Figure 9 As shown in (a), in the 30th step, pure water scattered from the periphery of the substrate W is caught by the retainer 42A.

[0181] In the 31st step, the spin chuck 41 rotates the substrate W at 1500 rpm for 2 seconds, and the rinse liquid nozzle 43b sprays pure water at 2000 mL / min toward the substrate W. In addition, in the 31st step, the cup lifting mechanism 425 switches the cup to be used from the cup 42C to the cup 42A (see FIG. Figure 9(b) As a result, the pure water is received by the socket 42C and flows into the upstream end of the recovery pipe 51 .

[0182] In the 32nd step, the spin chuck 41 rotates the substrate W at 1500 rpm for 0.2 seconds, and the rinse liquid nozzle 43b sprays pure water at 2000 mL / min toward the substrate W, and the IPA nozzle 43c sprays an organic solvent at 250 mL / min toward the substrate W. Figure 9 As shown in (c), in the 32nd step, the processing liquid scattered from the periphery of the substrate W is also received by the retainer 42C.

[0183] In the 33rd step, the spin chuck 41 rotates the substrate W at 1500 rpm for 30 seconds, and the IPA nozzle 43c sprays the organic solvent toward the main surface of the substrate W at 250 mL / min. Figure 9 As shown in (d), in the 33rd step, the processing liquid scattered from the periphery of the substrate W is also caught by the retainer 42C. Through the 32nd and 33rd steps, the pure water on the main surface of the substrate W is replaced with the organic solvent.

[0184] In the 34th step, the spin chuck 41 rotates the substrate W at 1500 rpm for 30 seconds. In the 34th step, no processing liquid is supplied to the substrate W. Figure 9 As shown in (e), in the 34th step, the organic solvent scattered from the periphery of the substrate W is also caught by the retainer 42C. In the 34th step, the substrate W is dried.

[0185] As described above, the retainer cup 42C receives the processing liquid (pure water and organic solvent) that splashes from the periphery of the substrate W during steps 31 through 34. This processing liquid flows into the upstream end of the recovery pipe 51. Hereinafter, the period from steps 31 through 34 in Table 2 is referred to as the discharge period.

[0186] In Table 2, during steps 31 and 32, the rinsing liquid nozzle 43b sprays pure water toward the substrate W. Therefore, the pure water discharge rate is the sum of the amount of pure water present on the main surface of the substrate W at the start of step 31 (i.e., the pure water film amount) and the total amount of pure water sprayed from the rinsing liquid nozzle 43b during the discharge period (hereinafter referred to as the pure water discharge rate). The start of step 31 can also be considered the time when the switch from the retainer cup 42A to the retainer cup 42C is initiated.

[0187] As described above, the amount of the pure water film depends on the rotation speed of the substrate W. Figure 10 Graph 1 is an example of a distance between each position on the substrate W and the center of the substrate W, and a thickness of a liquid film at each position. Figure 10Graph G5 is shown in FIG. The rotation speed of the substrate W corresponding to the graph G5 is 1500 rpm. Information on the amount of pure water film when the rotation speed of the substrate W is 1500 rpm is included in the correspondence information D2.

[0188] Alternatively, this graph can be based on the pure water flow rate in the 30th step before the socket switching step. Therefore, a graph can be pre-calculated for each flow rate and the pure water film amount can be calculated based on this graph. In this case, the correspondence information D2 includes the correspondence between the combination of the rotational speed and the pure water flow rate and the pure water film amount.

[0189] The pure water discharge rate is the total amount of pure water discharged onto the substrate W during the discharge period. The pure water discharge rate can be calculated by integrating the pure water flow rate over time. Specifically, the pure water discharge rate can be calculated by summing the product of the pure water flow rate and the required time (discharge time) for each step. In the example in Table 2, the pure water discharge rate can be expressed as (2000 × f² + 0.2) / 60.

[0190] The solvent discharge amount can be considered equal to the amount of organic solvent ejected onto the substrate W during the discharge period. The amount of organic solvent ejected during the discharge period can be calculated by taking the time-integrated value of the solvent flow rate. In the example in Table 2, the solvent discharge amount can be expressed as 250 × (0.2 + 30) / 60. Alternatively, the solvent discharge amount can be calculated by reducing the time-integrated value by a specified percentage.

[0191] Figure 11 4 is a flowchart showing an example of the operation of the concentration estimating unit 601. First, the concentration estimating unit 601 reads the recipe information D1 from the storage unit 603 (step S11: reading step).

[0192] Next, the concentration estimating unit 601 calculates the amount of pure water film based on the recipe information D1 (step S12: pure water film amount calculation process). Specifically, the concentration estimating unit 601 specifies the process for starting to use the support cup 42C (for example, the 31st process in Table 1 or Table 2) based on the recipe information D1, and specifies the rotation speed of the substrate W at the start time of the process based on the recipe information D1. The concentration estimating unit 601 may also specify the rotation speed of the substrate W in the process as the rotation speed of the substrate W at the start time of the process, or may specify the rotation speed of the substrate W in the process immediately before the process. Next, the concentration estimating unit 601 reads the corresponding relationship information D2 from the storage unit 603. Then, the concentration estimating unit 601 calculates the amount of pure water film based on the specified rotation speed and the corresponding relationship information D2 (refer to Figure 7 (c) or Figure 9 (b)).

[0193] In addition, when the correspondence information D2 includes the correspondence between the combination of the rotational speed of the substrate W and the pure water flow rate and the amount of pure water film, the concentration estimation unit 601 can also specify the pure water flow rate immediately before the start of the process using the support cup 42C based on the recipe information D1, and calculate the pure water film amount based on the specified rotational speed and pure water flow rate and the correspondence information D2.

[0194] Furthermore, the concentration estimating unit 601 calculates the total amount of pure water discharged during the discharge period (the pure water discharge amount) based on the recipe information D1 (step S13: pure water discharge amount calculation step). Specifically, the concentration estimating unit 601 identifies the steps in which pure water is discharged using the socket 42C based on the recipe information D1, and calculates the pure water discharge amount in each step by multiplying the pure water flow rate by the required time. The concentration estimating unit 601 then calculates the total discharge amount in each step as the pure water discharge amount.

[0195] Furthermore, the concentration estimating unit 601 calculates the total amount of organic solvent discharged during the discharge period (solvent discharge amount) based on the recipe information D1 (step S14: solvent discharge amount calculation step). Specifically, the concentration estimating unit 601 identifies the process in which the organic solvent is discharged using the retainer cup 42C based on the recipe information D1, and calculates the discharge amount of the organic solvent in that process by multiplying the solvent flow rate by the required time. The concentration estimating unit 601 then calculates the total discharge amount of the organic solvent in each process as the solvent discharge amount. Alternatively, the concentration estimating unit 601 may calculate the solvent discharge amount by subtracting a specified ratio from this total.

[0196] Next, the concentration estimating unit 601 divides the solvent discharge amount by the sum of the pure water film amount, the pure water ejection amount, and the solvent discharge amount to calculate the solvent concentration (step S15: solvent concentration calculation step).

[0197] As described above, the concentration estimating unit 601 calculates the solvent concentration based on the recipe information D1. Therefore, a concentration sensor for measuring the solvent concentration is not required, and the manufacturing cost of the substrate processing apparatus 100 can be reduced.

[0198] Furthermore, in the example described above, the concentration estimating unit 601 determines the amount of pure water film based on the rotational speed of the substrate W, and calculates the solvent concentration based on the amount of pure water film, the time-integrated value of the pure water flow rate, and the time-integrated value of the organic solvent flow rate. Therefore, the concentration estimating unit 601 can determine the solvent concentration with higher accuracy. When the concentration estimating unit 601 determines the amount of pure water film based on the pure water flow rate and the rotational speed of the substrate W, the solvent concentration can be determined with higher accuracy.

[0199] In addition, the recovery pipe connected to the support cup 42C is sometimes branched into multiple ones according to the type of processing liquid. For example, when the support cup 42C is used for an organic solvent and other first processing liquids, the support cup 42C is connected to the recovery pipe 51 for the organic solvent and the recovery pipe for the first processing liquid. In addition, a switching valve unit is also provided. When the first processing liquid is supplied to the substrate W, the switching valve unit connects the pipe for the first processing liquid with the support cup 42C, and when the organic solvent is supplied to the substrate W, the switching valve unit connects the recovery pipe 51 with the support cup 42C. In this case, multiple discharge ports are set in the support cup 42C. In this case, the discharge port can also be set in the recipe information D1. In addition, the concentration estimation unit 601 can also identify the process in which the discharge port for the organic solvent (i.e., the recovery pipe 51) is set, and calculate the pure water film amount, the pure water spray amount, and the solvent discharge amount in the same manner as described above.

[0200] <3-2-1-2. Measurement of Solvent Concentration Using a Concentration Sensor>

[0201] In the example described above, the control unit 6 calculates the solvent concentration of the mixed liquid discharged from the processing unit 4 based on the recipe information D1. However, this is not necessarily limited to this. The solvent concentration of the mixed liquid discharged from the processing unit 4 may also be measured using a concentration sensor.

[0202] Figure 12 This diagram schematically illustrates a second example of the substrate processing apparatus 100 according to the first embodiment. In this second example, a concentration sensor Sn5 is provided in each common recovery pipe 510. The concentration sensor Sn5 measures the solvent concentration of the mixed liquid flowing through the common recovery pipe 510 and outputs the measurement result to the control unit 6. The concentration sensor Sn5 may be a conductivity-type concentration sensor, an optical concentration sensor, or an ultrasonic concentration sensor.

[0203] The control unit 6 controls the switching unit 50 based on the solvent concentration measured by the concentration sensor Sn5. Specifically, the control unit 6 compares the solvent concentration measured by the concentration sensor Sn5 with a switching reference value. If the solvent concentration is less than the switching reference value, the control unit 6 causes the switching unit 50 to select the second state. If the solvent concentration is greater than the switching reference value, the control unit 6 causes the switching unit 50 to select the first state.

[0204] According to the second example, since the concentration sensor Sn5 measures the solvent concentration, the controller 6 can obtain the solvent concentration of the mixed liquid with higher accuracy. Therefore, the controller 6 can more appropriately control the switching unit 50, thereby more appropriately switching the supply destination of the mixed liquid between the first dehydrator 60 and another portion (e.g., the outside).

[0205] <Second embodiment>

[0206] Figure 131 is a diagram schematically showing an example of a substrate processing apparatus 100 according to a second embodiment. The substrate processing apparatus 100 according to the second embodiment differs from the substrate processing apparatus 100 according to the first embodiment in the configuration of a switching unit 50 .

[0207] In the second embodiment, the switching unit 50 also switches between the first state and the second state. However, in the second embodiment, the first state is a state in which the mixed liquid obtained by merging the mixed liquids from the plurality of treatment units 4 is supplied to the first dehydrator 60, and the second state is a state in which the mixed liquid obtained by merging the mixed liquids from the plurality of treatment units 4 is supplied to another portion (here, an external portion such as a wastewater treatment unit of the factory equipment).

[0208] like Figure 13 As shown, the switching section 50 includes a recovery pipe 51 and a switching valve section 520. The recovery pipe 51 includes a common recovery pipe 517, a first dehydration pipe 518 and other partial pipes 519. The common recovery pipe 517 is connected to each processing unit 4f cup 42 through each cup side recovery pipe 424. In the common recovery pipe 517, the mixed liquids from multiple processing units 4 can merge. The downstream end of the common recovery pipe 517 is connected to the upstream end of the first dehydration pipe 518 and the upstream end of the other partial pipes 519. The downstream end of the first dehydration pipe 518 is connected to the first dehydrator 60. The downstream end of the other partial pipes 519 is connected to other parts (here, the outside).

[0209] exist Figure 13 In the example, the switching valve section 520 includes a switching valve 523 and a switching valve 524. The switching valve section 520 switches the state in which the common recovery pipe 517 is connected to the first dehydrator 60 (i.e., the first state) and the state in which the common recovery pipe 517 is connected to other parts (here, the outside) (i.e., the second state). Figure 13 In the example shown in FIG. 5 , the switching valve 523 is inserted in the first dehydration pipe 518 , and the switching valve 524 is inserted in the other portion of the pipe 519 .

[0210] When the controller 6 closes the switching valve 523 and opens the switching valve 524, the mixed liquid from the processing unit 4 flows sequentially through the common recovery pipe 517 and the other pipe 519 before being supplied to the outside. When the controller 6 opens the switching valve 523 and closes the switching valve 524, the mixed liquid from the processing unit 4 flows sequentially through the common recovery pipe 517 and the first dehydration pipe 518 before being supplied to the first dehydrator 60.

[0211] The control unit 6 controls the switching unit 50 based on the solvent concentration of the mixed liquid flowing through the common recovery pipe 517. Figure 13In the example, a concentration sensor Sn51 is provided in the common recovery pipe 517. The concentration sensor Sn51 measures the solvent concentration of the mixed liquid flowing through the common recovery pipe 517 and outputs the measurement result to the control unit 6. An example of the structure of the concentration sensor Sn51 is the same as that of the concentration sensor Sn5. When the solvent concentration measured by the concentration sensor Sn51 is a second value that is less than the lower concentration limit value of the first separation membrane 62c, the control unit 6 causes the switching unit 50 to select the second state, and when the solvent concentration is a first value that is greater than the lower concentration limit value of the first separation membrane 62c, the control unit 6 causes the switching unit 50 to select the first state. As a more specific example, the control unit 6 may also compare the solvent concentration measured by the concentration sensor Sn51 with the switching reference value. When the solvent concentration is less than the switching reference value, the control unit 6 causes the switching unit 50 to select the second state, and when the solvent concentration is greater than the switching reference value, the control unit 6 causes the switching unit 50 to select the first state.

[0212] As described above, according to the second embodiment, the organic solvent recovery unit 5 switches the supply destination of the mixed liquid based on the solvent concentration of the mixed liquid obtained by merging the mixed liquids from the multiple processing units 4. Specifically, in the second embodiment, a single switching unit 50 is provided corresponding to the multiple processing units 4. Therefore, compared to the first embodiment, in which multiple switching units 50 are provided one-to-one with the multiple processing units 4, the manufacturing cost of the organic solvent recovery unit 5 can be reduced.

[0213] Furthermore, in the example described above, since concentration sensor Sn51 measures the solvent concentration, the control unit 6 can obtain the solvent concentration of the mixed liquid with higher accuracy. Consequently, the control unit 6 can more appropriately control the switching unit 50, thereby more appropriately switching the supply destination of the mixed liquid between the first dehydrator 60 and the outside. Furthermore, according to the second embodiment, a single concentration sensor Sn51 is provided corresponding to a plurality of processing units 4. Therefore, compared to the first embodiment, in which a plurality of concentration sensors Sn5 are provided one-to-one with a plurality of processing units 4, the manufacturing cost of the organic solvent recovery unit 5 can be reduced.

[0214] <Third embodiment>

[0215] Figure 14 Schematic diagram of an example of the organic solvent recovery unit 5 of the third embodiment. The organic solvent recovery unit 5 of the third embodiment differs from the organic solvent recovery unit 5 of the first or second embodiment in the presence or absence of the second dehydrator 70 and the supply source switching unit 80.

[0216] In the third embodiment, the second dehydrator 70 is used as the other component mentioned in the first or second embodiment. That is, the switching unit 50 supplies the mixed liquid to the second dehydrator 70 when the solvent concentration of the mixed liquid flowing through the common recovery pipe 517 (or the common recovery pipe 510) reaches a second value that is lower than the lower limit of the concentration of the first separation membrane 62c.

[0217] The second dehydrator 70 separates water from the mixed liquid, raising the solvent concentration of the mixed liquid to above the reuse reference value. While an example of the detailed configuration of the second dehydrator 70 will be described in detail below, the lower limit of the concentration of the second dehydrator 70 is lower than that of the first separation membrane 62c. For example, the lower limit of the concentration of the second dehydrator 70 is approximately zero. Furthermore, the energy efficiency of the second dehydrator 70 is lower than that of the first dehydrator 60, for example. Energy efficiency here refers to, for example, the ratio of the increase in solvent concentration to power consumption.

[0218] exist Figure 14 In the example shown, the switching valve unit 860 includes a switching valve 861 and a switching valve 862. The supplier switching unit 80 switches the supplier of the recycled liquid to the supply tank Tk3 between the first dehydrator 60 and the second dehydrator 70. The supplier switching unit 80 includes a liquid supply pipe 85 and a switching valve unit 860. The liquid supply pipe 85 includes a first dehydration pipe 851, a second dehydration pipe 852, and a common liquid supply pipe 850. The upstream end of the first dehydration pipe 851 is connected to the first dehydrator 60, the upstream end of the second dehydration pipe 852 is connected to the second dehydrator 70, and the downstream ends of the first dehydration pipe 851 and the second dehydration pipe 852 are connected to the upstream end of the common liquid supply pipe 850. The downstream end of the common liquid supply pipe 850 corresponds to the downstream end of the liquid supply pipe 85 and is connected to the supply tank Tk3.

[0219] The switching valve unit 860 switches between the first and second supply-side states, described below. The first supply-side state connects the first dehydrator 60 to the common liquid supply pipe 850 via the first dehydration pipe 851. The second supply-side state connects the second dehydrator 70 to the common liquid supply pipe 850 via the second dehydration pipe 852. The switching valve 861 is inserted into the first dehydration pipe 851, and the switching valve 862 is inserted into the second dehydration pipe 852.

[0220] The control unit 6 controls the supplier switching unit 80 based on the solvent concentration of the mixed liquid from the processing unit 4. As an example, the control unit 6 controls the switching valve unit 860 to select the first supplier state when the solvent concentration of the mixed liquid is greater than the switching reference value, and controls the switching valve unit 860 to select the second supplier state when the solvent concentration of the mixed liquid is less than the switching reference value.

[0221] As described above, in the third embodiment, when the solvent concentration of the mixed liquid is less than the switching reference value, the switching unit 50 selects the second state, and the supplier switching unit 80 selects the second supplier state. Consequently, the mixed liquid is supplied to the second dehydrator 70, which has a lower concentration lower limit. The second dehydrator 70 raises the solvent concentration of the mixed liquid to produce recycled liquid, which is then supplied to the supply tank Tk3 via the second dehydration pipe 852 and the common liquid supply pipe 850. Therefore, even when the solvent concentration of the mixed liquid is low, the organic solvent recovery unit 5 can produce recycled liquid from the mixed liquid and supply it to the supply tank Tk3. This further reduces the amount of mixed liquid discarded.

[0222] On the other hand, when the solvent concentration of the mixed liquid from the processing unit 4 is greater than the switching reference value, the switching unit 50 selects the first state, and the supply-side switching unit 80 selects the first supply-side state. Consequently, the mixed liquid is supplied to the first dehydrator 60. The highly efficient first dehydrator 60 increases the solvent concentration of the mixed liquid to produce recycled liquid, which is then supplied to the supply tank Tk3 via the first dehydration pipe 851 and the common liquid supply pipe 850. Thus, similar to the first embodiment, the organic solvent recovery unit 5 can efficiently produce recycled liquid and supply it to the supply tank Tk3.

[0223] Figure 15 : is a diagram schematically showing an example of the second dehydrator 70. Figure 15 In the example shown, the second dehydrator 70 includes a distillation column 701 and a cooler 702. The downstream end of the other portion piping 512 (or other portion piping 519) is connected to the distillation column 701. Furthermore, the upstream end of a steam piping 731 is connected to, for example, the upper portion of the distillation column 701. The downstream end of the steam piping 731 is connected to the cooler 702.

[0224] Distillation tower 701 includes a heating section (not shown) for heating the mixed liquid. Distillation tower 701 separates water from the mixed liquid by distillation utilizing the difference in boiling points between the organic solvent and water. Here, as an example, the boiling point of the organic solvent is lower than that of water, and the volatility of the organic solvent is higher than that of water. An example of the organic solvent is IPA. Distillation tower 701 vaporizes the mixed liquid and supplies vapor containing a large amount of organic solvent to the upstream end of steam piping 731. The vapor flowing into the upstream end of steam piping 731 contains not only the organic solvent but may also contain water, but its solvent concentration is higher than that before entering distillation tower 701. This vapor flows through steam piping 731 into cooler 702.

[0225] The upstream end of liquid piping 732 is also connected to cooler 702. Cooler 702 cools the vapor and condenses it. Cooler 702 may also include a heat exchanger, for example. The vapor passes through the interior of the heat exchanger. Cooler 702 may include a heat pump cooling source or a cooling source including a Peltier element to cool the heat exchanger. The vapor loses heat in the heat exchanger and becomes a liquid (i.e., a mixed liquid). This mixed liquid flows into the upstream end of liquid piping 732. The solvent concentration of this mixed liquid is higher than that of the mixed liquid before distillation column 701.

[0226] like Figure 15 As shown in FIG. 1 , the second dehydrator 70 may also include a plurality of distillation towers 701 and a plurality of coolers 702. Figure 15 In the example of , the distillation column 701 and the cooler 702 are connected in series. Figure 15 In this example, distillation tower 701 includes distillation tower 701a and distillation tower 701b, and cooler 702a and cooler 702b are shown as coolers 702. The downstream end of recovery pipe 51 is connected to distillation tower 701a, vapor pipe 731 connects distillation tower 701a and cooler 702a, and liquid pipe 732 connects cooler 702a and distillation tower 701b. Vapor from distillation tower 701a condenses in cooler 702a to form a mixed liquid, and the mixed liquid from cooler 702a is supplied to distillation tower 701b. The upstream end of vapor pipe 733 is connected to, for example, the upper portion of distillation tower 701b, and the downstream end of vapor pipe 733 is connected to cooler 702b. Vapor from the mixed liquid from distillation tower 701b is cooled and condensed in cooler 702b to form a mixed liquid. The upstream end of the cooler 702 b is connected to the liquid feeding pipe 85 (specifically, the second dehydration pipe 852 ), and the mixed liquid from the cooler 702 b is supplied to the supply tank Tk3 through the liquid feeding pipe 85 .

[0227] The second dehydrator 70 may include a pump and a valve (not shown). For example, a liquid delivery valve may be inserted through the second dehydration pipe 852 , or a pump may be inserted through the liquid pipe 732 .

[0228] Figure 16 This is a flowchart illustrating an example of the operation of the organic solvent recovery unit 5 according to the third embodiment. First, similarly to the first or second embodiment, the control unit 6 obtains the solvent concentration of the mixed liquid flowing through the common recovery pipe 510 or the common recovery pipe 517 (step S21). Next, similarly to step S2, the control unit 6 compares the solvent concentration with a switching reference value (step S22).

[0229] If the solvent concentration is above the switching reference value, the first dehydrator 60 separates water from the mixed liquid, producing the reused liquid, similarly to step S3 (step S23). Then, similarly to step S4, the first dehydrator 60 supplies the reused liquid to the supply tank Tk3 (step S24). Specifically, the controller 6 causes the supplier switching unit 80 to select the first supplier state, and then causes the first dehydrator 60 to supply the reused liquid to the supply tank Tk3.

[0230] On the other hand, in step S22, if the solvent concentration is less than the switching reference value, the second dehydrator 70 separates water from the mixed liquid to produce a reused liquid (step S25). Specifically, the controller 6 causes the switching unit 50 to select the second state. As an example, the controller 6 closes the switching valve 521 (or switching valve 523) and opens the switching valve 522 (or switching valve 524). As a result, the mixed liquid from the treatment unit 4 is supplied to the second dehydrator 70. The controller 6 controls the distillation column 701 and the cooler 702 to raise the solvent concentration of the mixed liquid in the second dehydrator 70 to above the reuse reference value. In other words, the second dehydrator 70 produces a reused liquid.

[0231] Next, the second dehydrator 70 supplies the reused liquid to the supply tank Tk3 (step S26). Specifically, the control unit 6 causes the supplier switching unit 80 to select the second supplier state, and then causes the second dehydrator 70 to supply the reused liquid to the supply tank Tk3.

[0232] As described above, in the third embodiment, the second dehydrator 70 operates when the solvent concentration of the mixed liquid from the treatment unit 4 is lower than the lower concentration limit of the first separation membrane 62c. Because the lower concentration limit of the second dehydrator 70 is low, the second dehydrator 70 can separate water from the mixed liquid, thereby increasing the solvent concentration of the mixed liquid. Consequently, the amount of organic solvent discarded can be further reduced.

[0233] In the above example, the second dehydrator 70 uses a distillation tower 701 and a cooler 702 to separate water from the mixed liquid, thereby increasing the solvent concentration of the mixed liquid. The lower limit of the concentration of the distillation tower 701 is very low, for example, approximately zero. Therefore, even if the solvent concentration of the mixed liquid discharged from the treatment unit 4 is very low, the second dehydrator 70 can still appropriately increase the solvent concentration of the mixed liquid.

[0234] In addition, Figure 15In the example, the second dehydrator 70 includes multiple distillation towers 701 and multiple coolers 702. Consequently, the solvent concentration of the mixed liquid increases each time the mixed liquid passes through the combination of distillation towers 701 and coolers 702. Therefore, the second dehydrator 70 can increase the solvent concentration of the mixed liquid by a greater amount than when using a single distillation tower 701 and a single cooler 702. The amount of increase in solvent concentration in the second dehydrator 70 is predetermined so that the solvent concentration after the increase is above the lower limit of the concentration of the first separation membrane 62c. Therefore, the number of distillation towers 701 and coolers 702 is predetermined based on this amount of increase.

[0235] On the other hand, the distillation tower 701 and cooler 702 consume relatively high amounts of power, resulting in low energy efficiency. Energy efficiency, for example, refers to the ratio of the increase in solvent concentration to the amount of power consumed. Furthermore, the distillation tower 701 is larger than the first membrane separator 62. In the third embodiment, when the solvent concentration of the mixed liquid from the treatment unit 4 is high, water is separated from the mixed liquid using the highly efficient first membrane separator 62, rather than the second dehydrator 70. Therefore, the organic solvent recovery unit 5 can more efficiently increase the solvent concentration of the mixed liquid than if the second dehydrator 70 alone were used to increase the solvent concentration of the mixed liquid.

[0236] <Fourth embodiment>

[0237] The substrate processing apparatus 100 according to the fourth embodiment differs from the substrate processing apparatus 100 according to the third embodiment in the configuration of a second dehydrator 70 . Figure 17 : is a diagram schematically showing an example of the second dehydrator 70 of the fourth embodiment. Figure 17 In the example of , the second dehydrator 70 includes an ultrasonic atomizing separator 704. The ultrasonic atomizing separator 704 is connected to the downstream end of the recovery pipe 51, the upstream end of the liquid supply pipe 85 (specifically, the first dehydration pipe 851) and the upstream end of the separation discharge pipe 705.

[0238] The mixed liquid flows through the recovery pipe 51 into the ultrasonic atomizer separator 704. The ultrasonic atomizer separator 704 uses ultrasonic vibrations to convert the mixed liquid into a mist. The mixed liquid mist contains organic solvent mist and water mist. These mists have different mass distributions. For example, the organic solvent mist tends to be lighter than the water mist. The ultrasonic atomizer separator 704 causes the lighter organic solvent mist to move primarily upward and the heavier water mist to move primarily downward, thereby separating the water from the mixed liquid.

[0239] For example, the ultrasonic atomizing separator 704 includes an atomizing tank, an ultrasonic vibrator, a separation container, and a gas supply unit, all of which are not shown. The mixed liquid from the recovery pipe 51 flows into the atomizing tank. The ultrasonic vibrator atomizes the mixed liquid in the tank. The mist from the atomizing tank flows into the separation container. The mist contains a mist of an organic solvent and a water mist. The gas supply unit supplies gas from the lower part of the separation container, causing the lighter mist of the organic solvent to move mainly upward and the heavier water mist to move mainly downward. The upstream end of the separation discharge pipe 705 is connected to the lower part of the separation container. Therefore, the water mist from the separation container mainly flows into the separation discharge pipe 705. The upstream end of the first dehydration pipe 851 is connected to the upper part of the separation container. The mist of the organic solvent is supplied to the supply tank Tk3 through the first dehydration pipe 851 and the common liquid supply pipe 850. In addition, a tank for merging the mist of the organic solvent can also be provided between the separation container and the first dehydration pipe 851.

[0240] The lower limit of the concentration of the ultrasonic atomizing separator 704 is also very low. For example, the lower limit is approximately zero. Therefore, even if the solvent concentration of the mixed liquid discharged from the processing unit 4 is very low, the second dehydrator 70 can appropriately increase the solvent concentration of the mixed liquid.

[0241] On the other hand, the ultrasonic atomizing separator 704 requires power to vibrate the ultrasonic vibrator and power to supply gas. In addition, when a gas other than air (such as nitrogen or a rare gas) is used as the gas, the cost of the gas is also required, thereby increasing the operating cost.

[0242] In the fourth embodiment, the second dehydrator 70 is activated when the solvent concentration of the mixed liquid from the treatment unit 4 is lower than the lower limit of the concentration of the first separation membrane 62c. Therefore, even if the solvent concentration of the mixed liquid discharged from the treatment unit 4 is very low, the second dehydrator 70 can appropriately increase the solvent concentration of the mixed liquid.

[0243] Furthermore, when the solvent concentration of the mixed liquid from the treatment unit 4 is high, water is separated from the mixed liquid by the first dehydrator 60 using the highly efficient first membrane separator 62, rather than the second dehydrator 70. Therefore, the organic solvent recovery unit 5 can increase the solvent concentration of the mixed liquid more efficiently than when the second dehydrator 70 alone is used to increase the solvent concentration of the mixed liquid.

[0244] <Fifth embodiment>

[0245] Figure 18 : is a diagram schematically showing an example of the organic solvent recovery unit 5 according to the fifth embodiment. Figure 18 In the example of , the organic solvent recovery unit 5 includes a concentration tank Tk1 , a first dehydrator 60 , a second dehydrator 70 , and a switching unit 50 .

[0246] The mixed liquid flows into the concentration tank Tk1 from the recovery pipe 51. The concentration tank Tk1 stores the mixed liquid.

[0247] The first dehydrator 60 includes a first circulation section 61, and the second dehydrator 70 includes a second circulation section 71. The first circulation section 61 includes a first membrane separator 62 and a first circulation pipe 63, and the second circulation section 71 includes a second membrane separator 72 and a second circulation pipe 73. Figure 18 In the example of , a portion of the first circulation pipe 63 and a portion of the second circulation pipe 73 are commonly used.

[0248] exist Figure 18 In this example, the first circulation piping 63 includes a downstream common piping 671, a first individual piping 630, and an upstream common piping 672, which is an example of a common circulation piping. The second circulation piping 73 includes the downstream common piping 671, the second individual piping 730, and the upstream common piping 672. In other words, the downstream common piping 671 and the upstream common piping 672 are shared by the first circulation piping 63 and the second circulation piping 73. The upstream end of the upstream common piping 672 is connected to, for example, the bottom of the concentrator tank Tk1, while the downstream end of the downstream common piping 671 is connected to, for example, the top of the concentrator tank Tk1. The upstream ends of the first individual piping 630 and the second individual piping 730 are connected to the downstream end of the upstream common piping 672, while the downstream ends of the first individual piping 630 and the second individual piping 730 are connected to the upstream end of the downstream common piping 671. The concentration tank Tk1 and the first circulation pipe 63 form a first circulation path, and the concentration tank Tk1 and the second circulation pipe 73 form a second circulation path.

[0249] The first membrane separator 62 is installed in the first separate pipe 630, and the second membrane separator 72 is installed in the second separate pipe 730. The first membrane separator 62 separates water from the mixed liquid, thereby increasing the solvent concentration of the mixed liquid. The second membrane separator 72 includes a second mixing path 72a, a second water path 72b, and a second separation membrane 72c. The second mixing path 72a, the second water path 72b, and the second separation membrane 72c are identical to the first mixing path 62a, the first water path 62b, and the first separation membrane 62c, respectively.

[0250] A portion of the mixed liquid flowing into the second mixing path 72a passes through the second separation membrane 72c and flows into the second water path 72b. The separated liquid flowing into the second water path 72b is discharged to the outside (e.g., to a wastewater treatment unit of a factory facility) through the separation discharge pipe 76.

[0251] The solvent concentration of the mixed liquid passing through the second mixing path 72a is higher than the solvent concentration of the mixed liquid immediately before flowing into the second mixing path 72a. The second dehydrator 70 uses the second membrane separator 72 to increase the solvent concentration of the mixed liquid to a reuse reference value or higher.

[0252] The lower limit value of the concentration of the second separation membrane 72c is lower than the lower limit value of the concentration of the first separation membrane 62c, and is lower than the solvent concentration of the mixed liquid from the treatment unit 4. Here, the case where the first separation membrane 62c and the second separation membrane 72c are zeolite membranes is described. The lower limit value of the concentration of the zeolite membrane is caused by the difference in the lattice structure of the zeolite membrane. The difference in the lattice structure of the zeolite membrane can be represented by a type (also called a structure code). For example, as types of zeolite membranes, there are LTA type, CHA type and DDR type. The lower limit value of the concentration of the LTA type zeolite membrane is, for example, about 50wt%, the lower limit value of the concentration of the CHA type zeolite membrane is, for example, about 70wt%, and the lower limit value of the concentration of the DDR type zeolite membrane is, for example, about 90wt%.

[0253] As one example, the second separation membrane 72c is an LTA-type zeolite membrane, and the first separation membrane 62c is a CHA-type or DDR-type zeolite membrane. As another example, the second separation membrane 72c is a CHA-type zeolite membrane, and the first separation membrane 62c is a DDR-type zeolite membrane. More generally, the first separation membrane 62c is a first-type zeolite membrane, and the second separation membrane 72c is a second-type zeolite membrane having a lower lower concentration limit than the first-type zeolite membrane.

[0254] exist Figure 18 In the example of FIG, the pump 74 and the second switching valve 752 are inserted into the upstream common pipe 672. Therefore, the pump 74 and the second switching valve 752 are commonly used by the first circulation unit 61 and the second circulation unit 71.

[0255] Furthermore, the separation constant of the first separation membrane 62c is higher than the separation constant of the second separation membrane 72c. The separation constant here is an indicator of the solvent concentration of a mixed liquid after the mixed liquid is circulated under specified fixed conditions in a circulation path provided with a membrane separator. The conditions mentioned here include, for example, the initial value of the solvent concentration of the mixed liquid, the flow rate and temperature during the circulation of the mixed liquid, and the circulation time. The higher the solvent concentration of the mixed liquid after circulation, the greater the separation constant. Conversely, the higher the separation constant, the greater the increase in the solvent concentration of the organic solvent by the membrane separator.

[0256] exist Figure 18In the example, the switching unit 50 includes a first three-way valve 791 and a second three-way valve 792. The switching unit 50 switches the circulation path between the first circulation path and the second circulation path. Specifically, the switching unit 50 switches between the first circulation state and the second circulation state, which will be described below. The first circulation state is a state in which the downstream common pipe 671 and the upstream common pipe 672 are interconnected via the first individual pipe 630. In the first circulation state, the mixed liquid circulates in the first circulation path including the concentration tank Tk1 and the first circulation pipe 63. Therefore, the mixed liquid is separated by the first membrane separator 62 on the first circulation path. In other words, the first circulation state corresponds to the first state in which the mixed liquid is supplied to the first dehydrator 60. The second circulation state is a state in which the downstream common pipe 671 and the upstream common pipe 672 are interconnected via the second individual pipe 730. In the second circulation state, the mixed liquid circulates in the second circulation path including the concentration tank Tk1 and the second circulation pipe 73. Therefore, the mixed liquid is separated by the second membrane separator 72. That is, the second circulation state corresponds to the second state in which the mixed liquid is supplied to the second dehydrator 70.

[0257] exist Figure 18 In the example, the first three-way valve 791 is connected to the upstream end of the downstream common pipe 671, the downstream end of the first individual pipe 630, and the downstream end of the second individual pipe 730. The first three-way valve 791 switches between a first downstream circulation state in which the downstream common pipe 671 communicates with the first individual pipe 630 and a second downstream circulation state in which the downstream common pipe 671 communicates with the second individual pipe 730. The second three-way valve 792 is connected to the downstream end of the upstream common pipe 672, the upstream end of the first individual pipe 630, and the upstream end of the second individual pipe 730. The second three-way valve 792 switches between a first upstream circulation state in which the upstream common pipe 672 communicates with the first individual pipe 630 and a second upstream circulation state in which the upstream common pipe 672 communicates with the second individual pipe 730.

[0258] If the control unit 6 causes the first three-way valve 791 to select the first downstream circulation state and the second three-way valve 792 to select the first upstream circulation state, the mixed liquid circulates in the first circulation path. In other words, the switching unit 50 selects the first circulation state. If the control unit 6 causes the first three-way valve 791 to select the second downstream circulation state and the second three-way valve 792 to select the second upstream circulation state, the mixed liquid circulates in the second circulation path. In other words, the switching unit 50 selects the second circulation state.

[0259] In the fifth embodiment, the control unit 6 also controls the switching unit 50 based on the solvent concentration of the mixed liquid from the processing unit 4. Figure 18In the example, a concentration sensor Sn51 is provided in the recovery pipe 51. The control unit 6 may also control the switching unit 50 based on the solvent concentration of the mixed liquid measured by the concentration sensor Sn51. Specifically, when the solvent concentration is above the switching reference value, the control unit 6 causes the switching unit 50 to select the first circulation state. As an example, the control unit 6 causes the first three-way valve 791 to select the first downstream circulation state, and causes the second three-way valve 792 to select the first upstream circulation state. Then, the control unit 6 causes the mixed liquid to circulate in the first circulation unit 61. As an example, the control unit 6 opens the second switching valve 752 and the discharge valve 67, and actuates the pump 74. The mixed liquid continues to flow into the first membrane separator 62 of the first circulation path, and therefore, the solvent concentration of the mixed liquid increases over time. The control unit 6 causes the mixed liquid to circulate in the first circulation unit 61 until the solvent concentration of the mixed liquid becomes above the reuse reference value. Thus, the reused liquid is stored in the concentration tank Tk1.

[0260] On the other hand, when the solvent concentration measured by concentration sensor Sn51 is greater than the lower limit of the concentration of the second separation membrane 72c and less than the switching reference value, the controller 6 causes the switching unit 50 to select the second circulation state. For example, the controller 6 causes the first three-way valve 791 to select the second downstream circulation state and the second three-way valve 792 to select the second upstream circulation state. The controller 6 then causes the mixed liquid to circulate in the second circulation unit 71. For example, the controller 6 opens the second switching valve 752 and the discharge valve 77 and activates the pump 74. As the mixed liquid continues to flow into the second membrane separator 72 of the second circulation path, the solvent concentration of the mixed liquid increases over time. The controller 6 causes the mixed liquid to circulate in the second circulation unit 71 until the solvent concentration of the mixed liquid reaches or exceeds the reuse reference value. Thus, the reused liquid is stored in the concentration tank Tk1.

[0261] Here, it is also assumed that the solvent concentration of the mixed liquid from the treatment unit 4 is lower than the lower concentration limit of the second separation membrane 72c. In this case, a third dehydrator (not shown) having a lower concentration limit lower than the lower concentration limit of the second separation membrane 72c can also be provided. The third dehydrator separates water from the mixed liquid from the treatment unit 4, thereby increasing the solvent concentration of the mixed liquid. As an example, the third dehydrator can include a distillation tower 701 and a cooler 702, or can include an ultrasonic atomizing separator 704. The switching unit 50 switches the dehydrator that separates water from the mixed liquid between the first dehydrator 60, the second dehydrator 70, and the third dehydrator based on the solvent concentration of the mixed liquid from the treatment unit 4.

[0262] As described above, in the fifth embodiment, even if the solvent concentration of the mixed liquid from the treatment unit 4 is less than the lower concentration limit of the first separation membrane 62c, when it is greater than the lower concentration limit of the second separation membrane 72c, the second dehydrator 70 uses the highly efficient second membrane separator 72 to separate water from the mixed liquid. Furthermore, when the solvent concentration of the mixed liquid from the treatment unit 4 is greater than the lower concentration limit of the first separation membrane 62c, the first dehydrator 60 uses the first separation membrane 62c, which has a higher separation constant than that of the second separation membrane 72c, to separate water from the mixed liquid. Therefore, the organic solvent recovery unit 5 can more efficiently increase the solvent concentration of the mixed liquid.

[0263] When the third dehydrator is installed, water is separated from the mixed liquid even if the solvent concentration of the mixed liquid from the treatment unit 4 is lower than the lower limit of the concentration of the second separation membrane 72c. Therefore, the amount of organic solvent discarded can be further reduced.

[0264] <Sixth embodiment>

[0265] Figure 19 This diagram schematically illustrates an example of an organic solvent recovery unit 5 according to the sixth embodiment. The organic solvent recovery unit 5 according to the sixth embodiment differs from the organic solvent recovery unit 5 according to the fifth embodiment in the destination of the mixed liquid supplied by the second dehydrator 70. The second dehydrator 70 supplies the separated mixed liquid to the first dehydrator 60 via a liquid supply pipe 78. Specifically, the upstream end of the liquid supply pipe 78 is connected to the second dehydrator 70, and the downstream end of the liquid supply pipe 78 is connected to the first dehydrator 60. Furthermore, the second dehydrator 70 increases the solvent concentration of the mixed liquid to a value above the lower concentration limit of the first separation membrane 62c.

[0266] As the second dehydrator 70 , the distillation tower 701 and the cooler 702 may be applied similarly to the second embodiment, and the ultrasonic atomizing separator 704 may be applied similarly to the third embodiment.

[0267] Figure 20 This is a flowchart illustrating an example of the operation of the organic solvent recovery unit 5 according to the sixth embodiment. First, similarly to step S21, the control unit 6 obtains the solvent concentration of the mixed liquid flowing through the common recovery pipe 510f or the common recovery pipe 517 (step S31: concentration acquisition step). Next, similarly to step S22, the control unit 6 determines whether the solvent concentration is greater than a specified switching reference value (step S32: concentration determination step).

[0268] When the solvent concentration of the mixed liquid is less than the switching reference value, the second dehydrator 70 separates water from the mixed liquid, thereby increasing the solvent concentration of the mixed liquid (Step S33: Second Dehydrator Process). Specifically, first, the control unit 6 causes the switching unit 50 to select the second state. As an example, the control unit 6 closes the switching valve 521 (or switching valve 523) and opens the switching valve 522 (or switching valve 524). As a result, the mixed liquid from the treatment unit 4 is supplied to the second dehydrator 70. In other words, if the solvent concentration of the mixed liquid is less than the switching reference value, the first membrane separator 62 may not be used. Therefore, the organic solvent recovery unit 5 supplies the mixed liquid to the second dehydrator 70.

[0269] When the second dehydrator 70 raises the solvent concentration of the mixed liquid to above a predetermined concentration reference value, the first dehydrator 60 separates water from the mixed liquid, further increasing the solvent concentration of the mixed liquid (step S34: first dehydrator step). The concentration reference value is previously set to a value that is above the concentration lower limit of the first separation membrane 62c and below the reuse reference value. The concentration reference value may also be set to a value that is above the switching reference value. For example, the concentration reference value is set to a value that is closer to the concentration lower limit of the first separation membrane 62c than the reuse reference value.

[0270] Similar to step S24, the first dehydrator 60 increases the solvent concentration of the mixed liquid from the second dehydrator 70 to a level equal to or higher than the reuse reference value (step S34: first dehydrator step). In other words, the first dehydrator 60 generates reused liquid. Next, the first dehydrator 60 supplies the reused liquid to the supply tank Tk3 (step S35: supply step).

[0271] On the other hand, in step S32, when the solvent concentration of the mixed liquid is above the switching reference value, the first dehydrator 60 separates water from the mixed liquid, thereby increasing the solvent concentration of the mixed liquid (step S34). Specifically, the control unit 6 first causes the switching unit 50 to select the first state. As an example, the control unit 6 opens the switching valve 521 (or switching valve 523) and closes the switching valve 522 (or switching valve 524). In other words, if the solvent concentration of the mixed liquid is above the switching reference value, the highly efficient first membrane separator 62 can be used. Therefore, the organic solvent recovery unit 5 supplies the mixed liquid from the treatment unit 4 to the first dehydrator 60, bypassing the second dehydrator 70.

[0272] The first dehydrator 60 increases the solvent concentration of the mixed liquid to a reuse reference value or more (step S34 ), and supplies the reuse liquid to the supply tank Tk3 (step S35 ).

[0273] As described above, when the solvent concentration of the mixed liquid from the treatment unit 4 is high, the second dehydrator 70 does not operate, and the solvent concentration of the mixed liquid is increased by the highly efficient first dehydrator 60. Therefore, power consumption by the second dehydrator 70 can be avoided. On the other hand, when the solvent concentration of the mixed liquid from the treatment unit 4 is low, the second dehydrator 70 first increases the solvent concentration of the mixed liquid to above the lower concentration limit of the first separation membrane 62c. Therefore, the second dehydrator 70 can supply a mixed liquid having a solvent concentration above the lower concentration limit of the first separation membrane 62c to the first dehydrator 60. Then, the highly efficient first dehydrator 60 increases the solvent concentration of the mixed liquid. Therefore, the organic solvent recovery unit 5 can more efficiently increase the solvent concentration of the mixed liquid to above the reuse reference value.

[0274] As with the fifth embodiment, the second dehydrator 70 can be configured to include a second circulation unit 71f including a second membrane separator 72. Figure 18 In this case, in step S33, the controller 6 causes the switching unit 50 to select the second circulation state. The controller 6 then opens the second switching valve 752 and the discharge valve 67 and activates the pump 74. Consequently, the second circulation unit 71 circulates the mixed liquid through the second circulation path including the concentration tank Tk1 and the second circulation pipe 73. In other words, the second membrane separator 72, which has a lower concentration reference value, continuously separates water from the mixed liquid. Consequently, the solvent concentration of the mixed liquid increases over time.

[0275] Then, when the solvent concentration of the mixed liquid exceeds the switching reference value, the controller 6 causes the switching unit 50 to select the first circulation state and open the discharge valve 67 in step S34. This causes the first circulation unit 61 to circulate the mixed liquid through the first circulation path including the concentration tank Tk1 and the first circulation pipe 63. In other words, the first membrane separator 62, which has a high separation constant, continuously separates water from the mixed liquid. Consequently, the solvent concentration of the mixed liquid increases over time.

[0276] As described above, when the solvent concentration of the mixed liquid from the treatment unit 4 is low, the second membrane separator 72, which has a lower lower concentration limit, first raises the solvent concentration of the mixed liquid to above the lower concentration limit of the first separation membrane 62c. Then, when the solvent concentration of the mixed liquid exceeds the lower concentration limit of the first separation membrane 62c, the solvent concentration of the mixed liquid is further increased by the first membrane separator 62, which has a higher separation constant, rather than the second membrane separator 72, which has a lower separation constant. Therefore, the organic solvent recovery unit 5 can increase the solvent concentration of the mixed liquid with greater reliability and efficiency.

[0277] While the organic solvent recovery apparatus (organic solvent recovery unit 5), substrate processing apparatus 100, and organic solvent recovery method have been described in detail above, such descriptions are provided for illustrative purposes only and are not intended to limit the present invention. Furthermore, the various variations described above may be combined and applied as long as they do not conflict with one another. Furthermore, it should be understood that numerous variations not illustrated in these examples may be envisioned without departing from the scope of the present invention.

[0278] For example, the organic solvent recovery unit 5 may include a filter to capture impurities in the reused liquid. For example, the organic solvent recovery unit 5 may include a purification tank, a purification circulation pipe connected to the purification tank, a switching valve inserted into the purification circulation pipe, a pump, and a filter. In this way, the organic solvent recovery unit 5 can supply reused liquid with a low impurity concentration to the supply tank Tk3.

[0279] [Explanation of Symbols]

[0280] 100 substrate processing device

[0281] 4 processing units

[0282] 41 Substrate holding part (rotating chuck)

[0283] 42 Cup

[0284] 430 ejection part

[0285] 50 Switching unit

[0286] 51 Recovery piping

[0287] 510, 517 Recovery piping (common recovery piping)

[0288] 6 Control Unit

[0289] 60 No. 1 dehydrator

[0290] 62 No. 1 membrane separator

[0291] 62c 1st separation membrane

[0292] 63 1st circulation piping

[0293] 630 1st individual piping

[0294] 64, 74 Liquid delivery unit (pump)

[0295] 672 Common circulation piping (upstream common piping)

[0296] 70 Second Dehydrator

[0297] 701 Distillation Tower

[0298] 704 Ultrasonic Atomization Separator

[0299] 72 Second membrane separator

[0300] 72c Second separation membrane

[0301] 73 Second circulation piping

[0302] 730 Second individual piping

[0303] D1 formula information

[0304] D2 correspondence information

[0305] Sn5, Sn51 concentration sensors

[0306] Tk1 Concentrator

[0307] Tk3 supply tank

[0308] W substrate.

Claims

1. An organic solvent recovery device, comprising: A recovery pipe for circulating a mixed liquid of an organic solvent and water discharged from a processing unit for processing a substrate; a first dehydrator comprising a first membrane separator, the first membrane separator comprising a first separation membrane having an applicable range of solvent concentration, and separating water from the mixed liquid to increase the solvent concentration of the mixed liquid; a switching portion for switching between a first state in which the solvent concentration of the mixed liquid discharged from the processing unit is increased by the first dehydrator and a second state in which the mixed liquid discharged from the processing unit is supplied to a portion other than the first dehydrator; and The control unit causes the switching unit to select the first state when the solvent concentration of the mixed liquid is the lower limit value of the applicable range, i.e., the first value above the lower concentration limit value; and causes the switching unit to select the second state when the solvent concentration of the mixed liquid is the second value less than the lower concentration limit value.

2. The organic solvent recovery device according to claim 1, comprising a storage unit, The storage unit stores recipe information indicating the processing contents of the substrate to be processed by the processing unit, and The control unit calculates a solvent concentration of the mixed liquid discharged from the processing unit based on the recipe information.

3. The organic solvent recovery device according to claim 2, wherein The processing unit comprises: a substrate holding portion for holding the substrate and rotating it; a spraying portion that sequentially sprays pure water and an organic solvent toward the main surface of the substrate held by the substrate holding portion; and a cup having a cylindrical shape surrounding the substrate holding portion and catching liquid scattered from the periphery of the substrate; The upstream end of the recovery pipe is connected to the socket. The recipe information sets the flow rate and discharge time of pure water sprayed onto the substrate, the flow rate and discharge time of the organic solvent sprayed onto the substrate, and the rotation speed of the substrate. The storage unit stores correspondence information indicating a correspondence between the rotation speed and a pure water film amount, the pure water film amount being an amount of pure water on the main surface of the substrate. The control unit calculates the pure water film amount based on the rotational speed of the substrate specified according to the recipe information and the corresponding relationship information, and calculates the solvent concentration of the mixed liquid discharged from the processing unit based on the pure water film amount, the time integral value of the pure water flow rate, and the time integral value of the solvent flow rate.

4. The organic solvent recovery device according to claim 2, comprising a concentration sensor for measuring the solvent concentration of the mixed liquid, and The control unit controls the switching unit based on the solvent concentration of the mixed liquid measured by the concentration sensor.

5. The organic solvent recovery device according to any one of claims 1 to 4, wherein The mixed liquid from the plurality of processing units flows through the recovery pipe.

6. The organic solvent recovery device according to any one of claims 1 to 4, wherein The first dehydrator includes a first circulation section having a first circulation pipe in which the first membrane separator is installed, and the mixed liquid is circulated through the first circulation pipe.

7. The organic solvent recovery device according to any one of claims 1 to 4, wherein The other portion includes a pipe for discharging the mixed liquid to the outside.

8. The organic solvent recovery device according to any one of claims 1 to 4, wherein The other part includes a second dehydrator that separates water from the mixed liquid to increase the solvent concentration of the mixed liquid.

9. The organic solvent recovery device according to claim 8, wherein The second dehydrator increases the solvent concentration of the mixed liquid to be equal to or higher than the lower limit of the concentration of the first separation membrane, and supplies the mixed liquid having the solvent concentration equal to or higher than the lower limit to the first dehydrator.

10. The organic solvent recovery device according to claim 8, wherein The second dehydrator includes at least one of a distillation tower and an ultrasonic atomizing separator.

11. The organic solvent recovery device according to claim 8, wherein The second dehydrator includes a second membrane separator having a second separation membrane. The lower limit of the applicable range of the solvent concentration of the second separation membrane is smaller than the lower limit of the concentration of the first separation membrane, and The separation constant of the first separation membrane is higher than the separation constant of the second separation membrane.

12. The organic solvent recovery device according to claim 11, wherein The second dehydrator comprises: a second circulation pipe provided with the second membrane separator; and The liquid delivery portion is provided in the second circulation pipe.

13. The organic solvent recovery device according to claim 12, comprising a concentration tank for storing the mixed liquid from the recovery pipe. The first dehydrator includes a first circulation pipe connected to the concentration tank and provided with the first membrane separator. The first circulation piping includes: A common circulation pipe is provided with the liquid delivery portion; and a first separate pipe provided with the first membrane separator; The second circulation piping includes: The common circulation piping; and The second separate pipe is provided with the second membrane separator; and The switching unit switches between the first state in which the mixed liquid circulates through the concentrating tank and the first circulation pipe and the second state in which the mixed liquid circulates through the concentrating tank and the second circulation pipe.

14. A substrate processing apparatus comprising: The organic solvent recovery device according to any one of claims 1 to 4; and The processing unit.

15. A method for recovering an organic solvent, comprising: a concentration acquisition step of acquiring the solvent concentration of a mixed solution of an organic solvent and water discharged from a processing unit for processing a substrate; and a dehydrator step of separating water from the mixed liquid using a first membrane separator including a first separation membrane when the solvent concentration is at a first value, thereby increasing the solvent concentration of the mixed liquid; and The first value is equal to or greater than the lower limit of the applicable range of the solvent concentration of the first separation membrane.

Images