Wafer processing device

Abstract

To provide a wafer processing device capable of improving a solvent concentration in a shorter time.SOLUTION: A wafer processing device 100 comprises a processing tank Tk0, a wafer holding part 10, a discharge part 4, and an organic solvent collection part 5. The processing tank Tk0 stores a liquid L1 therein. The wafer holding part 10 holds a plurality of wafers W and immerses the plurality of wafers W in the liquid L1 in the processing tank Tk0. The discharge part 4 discharges a second concentration liquid, where the solvent concentration is higher than that of a first concentration liquid, while avoiding at least a portion of the first concentration liquid in the liquid L1 from the processing tank Tk0 in which the liquid L1 containing water and an organic solvent having a lighter specific weight than water is stored in a concentration distribution where the solvent concentration is higher on an upper side than a lower side. The organic solvent collection part 5 includes a dehydrator for generating a third concentration liquid, where the solvent concentration is higher than that of the second concentration liquid, by separating the water from the second concentration liquid that is discharged by the discharge part 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus. [Background technology]

[0002] Patent Document 1 discloses an IPA recovery system that recovers aqueous IPA (isopropyl alcohol) discharged from a processing unit that processes substrates. The IPA recovery system includes a storage tank, a circulation pipe, a pump, a dehydration unit, and a filter. The storage tank is supplied with aqueous IPA from the processing unit. The circulation pipe is connected to the storage tank and returns the aqueous IPA from the storage tank to the storage tank. A pump is provided in the circulation pipe and transports the aqueous IPA from the upstream end to the downstream end of the circulation pipe. A filter is provided in the circulation pipe and removes foreign matter from the aqueous IPA. A dehydration unit is provided in the circulation pipe and removes moisture from the aqueous IPA.

[0003] The recovery system circulates the wet IPA through a circulation path that includes a storage tank and circulation piping. This circulation causes the wet IPA to pass through a filter and a spin-drying unit. This increases the IPA concentration of the circulating wet IPA and reduces the amount of foreign matter in the wet IPA. In other words, this circulation results in clean wet IPA with a high IPA concentration being stored in the storage tank. This wet IPA in the storage tank is then supplied back to the processing unit. This reduces the amount of IPA that is wasted. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-41505 Summary of the Invention [Problem to be solved by the invention]

[0005] When a mixed liquid with a low solvent concentration is collected from the processing unit into the storage tank, there is a problem in that it takes a long time to increase the solvent concentration of the mixed liquid in the storage tank.

[0006] Therefore, an object of the present disclosure is to provide a substrate processing apparatus that can increase the solvent concentration in a shorter time. [Means for solving the problem]

[0007] A first aspect is a substrate processing apparatus comprising: a processing tank for storing a liquid; a substrate holding unit for holding a plurality of substrates and immersing the plurality of substrates in the liquid in the processing tank; a discharge unit for discharging a second concentration liquid having a higher solvent concentration than the first concentration liquid from the processing tank, the second concentration liquid being higher than the first concentration liquid, while avoiding at least a portion of the first concentration liquid; and an organic solvent recovery unit including a dehydrator for separating water from the second concentration liquid discharged by the discharge unit and producing a third concentration liquid having a higher solvent concentration than the second concentration liquid.

[0008] A second aspect is a substrate processing apparatus according to the first aspect, comprising: a pure water supply unit including a supply pipe for supplying pure water toward the processing tank; a solvent vapor supply unit including a discharge pipe for discharging vapor of the organic solvent, which is more volatile than the pure water, into a space above the processing tank; and a control unit; wherein the substrate holding unit raises and lowers the plurality of substrates between an immersion position inside the processing tank and a position above the processing tank; and the control unit controls the pure water supply unit to supply the pure water to the processing tank and the substrate holding unit to lower the plurality of substrates to the immersion position to immerse the plurality of substrates in the pure water, and while the plurality of substrates are immersed in the pure water, controls the solvent vapor supply unit to discharge the vapor from the discharge pipe to form a liquid film of the organic solvent on the liquid surface of the processing tank, and while the liquid film is formed, raises the plurality of substrates from the immersion position, and controls the discharge unit to discharge the second concentration liquid from the processing tank when the plurality of substrates are not immersed in the pure water.

[0009] A third aspect is a substrate processing apparatus according to the second aspect, further comprising a pressure adjustment unit that adjusts the pressure in a processing chamber in which the processing tank is housed, and the control unit dries the plurality of substrates while the pressure adjustment unit reduces the pressure in the processing chamber to a first pressure value, and controls the exhaust unit to exhaust the second concentration liquid from the processing tank while the pressure adjustment unit adjusts the pressure in the processing chamber to a value higher than the first pressure value.

[0010] A fourth aspect is the substrate processing apparatus according to any one of the first to third aspects, wherein the solvent concentration of the second concentration solution is equal to or greater than a lower limit of an applicable range of solvent concentration of the dehydrator.

[0011] A fifth aspect is the substrate processing apparatus according to the fourth aspect, wherein the dehydrator includes a membrane separator having a separation membrane that allows water contained in the second concentration solution to permeate.

[0012] A sixth aspect is a substrate processing apparatus according to any one of the first to fifth aspects, wherein the discharge section includes a discharge pipe having an upstream end immersed in the liquid in the processing tank at a height position corresponding to the second concentration liquid and a downstream end connected to the organic solvent recovery section, and a discharge valve inserted in the discharge pipe.

[0013] A seventh aspect is a substrate processing apparatus according to any one of the first to sixth aspects, wherein the discharge unit includes a first discharge pipe communicating with a bottom of the processing tank, a second discharge pipe communicating with the bottom of the processing tank and connected to the organic solvent recovery unit, a switching valve unit that switches between a first state in which the liquid from the bottom of the processing tank flows through the first discharge pipe and a second state in which the liquid flows through the second discharge pipe, and a control unit that causes the switching valve unit to select the first state to discharge the first concentration liquid from the bottom of the processing tank, and then causes the switching valve unit to select the second state to discharge the second concentration liquid from the bottom of the processing tank.

[0014] An eighth aspect is a substrate processing apparatus according to the seventh aspect, comprising a chamber accommodating the processing tank, wherein the exhaust unit further includes a tank valve for switching the bottom of the processing tank between open and closed states, wherein the upstream end of the first exhaust pipe is connected to the bottom of the chamber, wherein the flow rate of the liquid flowing out from the bottom of the processing tank is greater than the flow rate of the liquid flowing into the upstream end of the first exhaust pipe, and wherein the control unit causes the switching valve unit to select the second state from the first state, via an interrupted state in which the tank valve is closed.

[0015] A ninth aspect is a substrate processing apparatus according to the seventh or eighth aspect, comprising: a pure water supply unit including a supply pipe for flowing pure water toward the processing tank and storing the pure water in the processing tank; and a solvent vapor supply unit including a discharge pipe for discharging vapor of the organic solvent, which is more volatile than the pure water, into a space above the processing tank; the substrate holding unit raises and lowers the plurality of substrates between an immersion position inside the processing tank and a position above the processing tank; and the control unit controls the pure water supply unit to supply the pure water to the processing tank. and supplying the organic solvent to the substrate holding unit, lowering the plurality of substrates to the immersion position to immerse the plurality of substrates in the pure water, and while the plurality of substrates are immersed in the pure water in the processing tank, discharging the vapor of the organic solvent from the discharge pipe to form a liquid film of the organic solvent on the liquid surface in the processing tank, and while the liquid film has been formed, causing the substrate holding unit to raise the plurality of substrates, causing the switching valve unit to select the first state to flow the liquid in the processing tank as the first concentration liquid into the first discharge pipe.

[0016] A tenth aspect is a substrate processing apparatus according to any one of the first to seventh aspects, further comprising a control unit, wherein the processing tank includes a main tank for storing the liquid and an upflow tank for receiving the liquid overflowing from the top of the main tank, the discharge unit is provided at the bottom of the processing tank and includes an upflow pipe for discharging pure water into the processing tank to cause the liquid to overflow from the main tank, and a discharge pipe having an upstream end connected to the upflow tank and a downstream end connected to the organic solvent recovery unit, and the control unit causes the discharge unit to discharge the pure water from the upflow pipe to cause the second concentration liquid of the liquid in the processing tank to flow into the upflow tank, and to supply the second concentration liquid from the upflow tank to the organic solvent recovery unit through the discharge pipe. [Effects of the Invention]

[0017] According to the first aspect, the organic solvent recovery unit generates the third concentration liquid from the second concentration liquid, which has a higher solvent concentration than the first concentration liquid. Therefore, the organic solvent recovery unit can generate the third concentration liquid in a shorter time than when generating the third concentration liquid from the first concentration liquid.

[0018] According to the second aspect, the substrate can be subjected to a pure water treatment by immersing the substrate in pure water. Furthermore, by raising the substrate, the main surface of the substrate passes through a liquid film of the organic solvent. This allows the organic solvent to adhere to the main surface of the substrate. The organic solvent is easily volatile, making it easy to dry the substrate. Meanwhile, since a liquid film of the organic solvent is formed on the liquid surface of the treatment tank, the liquid is stored in the treatment tank with a concentration distribution in which the solvent concentration is higher at the top. Therefore, the second concentration liquid can be discharged from the treatment tank at an earlier timing after the substrate has been treated.

[0019] According to the third aspect, when the pressure inside the processing chamber is relatively high, a relatively high pressure is applied to the liquid surface of the processing tank, which allows the discharge unit to discharge the second concentration liquid more quickly.

[0020] According to the fourth aspect, the dehydrator can appropriately separate water from the second concentrate.

[0021] According to the fifth aspect, water can be separated from the second concentration liquid with low energy. Furthermore, although the lower limit of the applicable range of the separation membrane is relatively high, the discharge unit supplies the second concentration liquid with a high solvent concentration to the organic solvent recovery unit. Therefore, the separation membrane can appropriately separate water from the second concentration liquid. In other words, a separation membrane capable of separating water with low energy can be appropriately utilized.

[0022] According to the sixth aspect, the liquid in the treatment tank above the upstream end of the discharge pipe flows into the discharge pipe. Since the solvent concentration in the upper part of the liquid is high, the second concentration liquid can be supplied to the organic solvent recovery unit through the discharge pipe.

[0023] According to the seventh aspect, the first concentration liquid and the second concentration liquid can be separately discharged from the bottom of the processing tank. In addition, by adjusting the discharge amount of the first concentration liquid, the solvent concentration of the second concentration liquid can be adjusted.

[0024] According to the eighth aspect, the flow rate of the liquid flowing out from the bottom of the processing tank is greater than the flow rate of the liquid flowing into the upstream end of the first discharge pipe, so that the liquid accumulates at the bottom of the chamber while flowing into the upstream end of the first discharge pipe. That is, in the first state, the first concentration liquid accumulates at the bottom of the chamber and is discharged through the first discharge pipe. After the first state, the tank valve is closed, so that the first concentration liquid accumulated at the bottom of the chamber is discharged through the first discharge pipe. Thereafter, the switching valve unit selects the second state. This makes it possible to prevent the second concentration liquid from mixing with the first concentration liquid accumulated at the bottom of the chamber. That is, the discharge unit can supply the second concentration liquid to the organic solvent recovery unit while preventing a decrease in the solvent concentration of the second concentration liquid.

[0025] According to the ninth aspect, the substrate is raised and the first concentration solution is discharged in parallel, thereby improving the throughput of the process.

[0026] According to the tenth aspect, the second concentration liquid is extracted from the liquid in the main tank by overflowing the second concentration liquid from the main tank into the upflow tank, and the discharge unit discharges the second concentration liquid from the upflow tank. Therefore, the solvent concentration of the second concentration liquid can be easily adjusted by adjusting the supply amount of pure water. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a diagram schematically illustrating an example of a substrate processing apparatus according to a first embodiment. [Figure 2] FIG. 10 is a diagram schematically illustrating another example of a second concentration discharge unit. [Figure 3] 5 is a flowchart showing an example of substrate processing by the processing unit according to the first embodiment. [Figure 4] FIG. 10 is a diagram showing an example of a change in the state of a processing unit over time. [Figure 5] FIG. 10 is a diagram showing an example of a change in the state of a processing unit over time. [Figure 6] FIG. 2 is a diagram schematically illustrating an example of an organic solvent recovery section. [Figure 7] FIG. 10 is a diagram schematically illustrating an example of a substrate processing apparatus according to a first example of a second embodiment. [Figure 8] 10 is a flowchart showing an example of the operation of a processing unit according to a first example of the second embodiment. [Figure 9] FIG. 10 is a diagram showing an example of a change in the state of a processing unit over time. [Figure 10] 10A and 10B are diagrams showing an example of a change over time in the state of a processing unit discharging liquid from a processing tank. [Figure 11] FIG. 10 is a diagram schematically illustrating an example of a substrate processing apparatus according to a second example of the second embodiment. [Figure 12] 10 is a flowchart showing an example of the operation of the substrate processing apparatus according to the second example. [Figure 13] FIG. 10 is a diagram showing an example of time-dependent changes in the state of a processing unit according to a second example. [Figure 14]FIG. 10 is a diagram showing an example of time-dependent changes in the state of a processing unit according to a second example. [Figure 15] FIG. 10 is a diagram schematically illustrating a third example of the substrate processing apparatus according to the second embodiment. [Figure 16] 10A and 10B are diagrams showing an example of the change over time in the state of the processing unit after the solvent replacement process. [Figure 17] FIG. 10 is a diagram schematically illustrating an example of a substrate processing apparatus according to a third embodiment. [Figure 18] FIG. 11 is a diagram schematically illustrating an example of a change over time in the state of a processing unit in a second concentration discharge step according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, the embodiments will be described in detail with reference to the drawings. In the drawings, the dimensions and numbers of parts are exaggerated or simplified as necessary for ease of understanding. Parts having similar configurations and functions are designated by the same reference numerals, and duplicate explanations will be omitted below.

[0029] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions of them may be omitted to avoid duplication.

[0030] Furthermore, in the following description, even if ordinal numbers such as "first" or "second" are used, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and are not limited to the order that may result from these ordinal numbers.

[0031] When expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) are used, unless otherwise specified, the expressions not only strictly represent the positional relationship but also represent a state in which there is a relative displacement in terms of angle or distance within a range in which tolerance or equivalent functionality is obtained. When expressions indicating an equal state (e.g., "identical," "equal," "homogeneous," etc.) are used, the expressions not only represent a state in which there is strict quantitative equality but also represent a state in which there is a difference in which tolerance or equivalent functionality is obtained, unless otherwise specified. When expressions indicating a shape (e.g., "rectangular shape" or "cylindrical shape," etc.) are used, the expressions not only represent a geometrically strict shape but also represent a shape with, for example, irregularities or chamfers within a range in which equivalent effects are obtained, unless otherwise specified. When the expressions "comprise," "include," "have," "includes," "includes," or "have" are used to describe one component, the expressions are not exclusive expressions that exclude the presence of other components. When the phrase "at least one of A, B, and C" is used, the phrase includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0032] First Embodiment <Outline of substrate processing equipment> Fig. 1 is a diagram schematically illustrating an example of a substrate processing apparatus 100 according to a first embodiment. In the example of Fig. 1, the substrate processing apparatus 100 is a so-called batch processing apparatus that processes a plurality of substrates W to be processed collectively. The substrates W to be processed in the substrate processing apparatus 100 are, for example, semiconductor substrates. The shape of the substrates W to be processed is, for example, a disk shape.

[0033] As shown in FIG. 1, the substrate processing apparatus 100 includes a processing unit 1, a discharge section 4, an organic solvent recovery section 5, and a control section 6.

[0034] The processing unit 1 processes a plurality of substrates W using pure water and an organic solvent. As shown in FIG. 1, the processing unit 1 includes a processing tank Tk0 and a substrate holder 10. A liquid L1 is stored in the processing tank Tk0. Here, the liquid L1 is a liquid containing water and an organic solvent. The specific gravity of the organic solvent is smaller than that of water. Therefore, the liquid L1 stored in the processing tank Tk0 has a concentration distribution in which the solvent concentration is higher in the upper part than in the lower part. The solvent concentration here refers to the concentration of the organic solvent in the liquid L1.

[0035] In the example of FIG. 1, a high-concentration portion L11 is formed in the upper portion of the liquid L1 stored in the processing tank Tk0. The high-concentration portion L11 is a portion of the liquid L1 where the solvent concentration is relatively high. Hereinafter, the portion of the liquid L1 below the high-concentration portion L11 will also be referred to as the low-concentration portion L12. The low-concentration portion L12 is a portion of the liquid L1 where the solvent concentration is relatively low. Note that the high-concentration portion L11 may have a concentration distribution in which the solvent concentration tends to be higher at the upper side. The low-concentration portion L12 may be almost entirely water. In other words, the solvent concentration of the low-concentration portion L12 may be uniform and almost zero. Alternatively, the low-concentration portion L12 may have a concentration distribution in which the solvent concentration tends to be higher at the upper side.

[0036] As an example, such a concentration distribution can be formed in the liquid L1 in the processing tank Tk0 by a series of processes described below on the substrate W. Alternatively, such a concentration distribution can be formed in the liquid L1 by leaving the liquid L1 in the processing tank Tk0, in which water and the organic solvent are mixed at a more uniform concentration, for a long period of time. This is because the specific gravity of the organic solvent is smaller than that of water, and therefore the organic solvent in the processing tank Tk0 increases in the liquid L1 over time.

[0037] The substrate holder 10 holds a plurality of substrates W in an upright position. The upright position here means that the thickness direction of the substrates W is along the horizontal direction (direction perpendicular to the plane of the paper in FIG. 1). The substrate holder 10 also holds a plurality of substrates W in a state where the substrates W are arranged along their thickness direction (direction perpendicular to the plane of the paper in FIG. 1). The substrate holder 10 can hold a plurality of substrates W in a state where they are immersed in liquid L1 in the processing tank Tk0.

[0038] The discharge unit 4 discharges the liquid L1 from the processing tank Tk0. The discharge unit 4 includes a first concentration discharge unit 41 and a second concentration discharge unit 42. The first concentration discharge unit 41 will be described later.

[0039] The second concentration discharge unit 42 discharges a second concentration liquid having a higher solvent concentration than the first concentration liquid from the processing tank Tk0, avoiding at least a portion of the first concentration liquid in the liquid L1. The at least a portion of the first concentration liquid is a liquid having a lower solvent concentration than the first concentration liquid in the liquid L1, i.e., a lower portion of the liquid L1. In other words, the first concentration liquid is a liquid that mainly belongs to the low concentration portion L12. On the other hand, the second concentration liquid is a liquid that mainly belongs to the high concentration portion L11. The solvent concentration of the second concentration liquid may be, for example, 50 wt% or more, 60 wt% or more, or 70 wt% or more.

[0040] 1, the second concentration discharge unit 42 includes a second discharge pipe 421. In the example of FIG. 1, the upstream end (upstream opening) of the second discharge pipe 421 is provided at a height position corresponding to the second concentration liquid and is immersed in the liquid L1 in the treatment tank Tk0. The height position of the upstream end of the second discharge pipe 421 may be, for example, higher than the vertical center of the treatment tank Tk0. In the example of FIG. 1, the upstream end of the second discharge pipe 421 is located near the boundary between the high concentration portion L11 and the low concentration portion L12.

[0041] Of the liquid L1 in the processing tank Tk0, the portion below the upstream end of the second discharge pipe 421 is less likely to flow into the second discharge pipe 421. Because the solvent concentration in the lower portion is low, liquid L1 with a relatively low solvent concentration is less likely to flow into the second discharge pipe 421. On the other hand, of the liquid L1 in the processing tank Tk0, the portion at the same level as or above the upstream end is more likely to flow into the second discharge pipe 421. Because the solvent concentration in the upper portion is high, liquid L1 with a relatively high solvent concentration flows into the second discharge pipe 421 as the second concentration liquid. In the example of FIG. 1, the upstream end of the second discharge pipe 421 is connected to the side wall of the processing tank Tk0. The downstream end of the second discharge pipe 421 is connected to the organic solvent recovery unit 5.

[0042] 1, a discharge valve 422 is inserted in the second discharge pipe 421. When the control unit 6 opens the discharge valve 422, an upper portion of the liquid L1 (i.e., the second concentrated liquid) is discharged through the second discharge pipe 421, and the second concentrated liquid is supplied to the organic solvent recovery unit 5 through the second discharge pipe 421. As shown in FIG. 1, the second discharge pipe 421 may be provided with a liquid delivery unit 423. The liquid delivery unit 423 is, for example, an ejector, and delivers the second concentrated liquid from the processing tank Tk0 toward the organic solvent recovery unit 5.

[0043] FIG. 2 is a schematic diagram illustrating another example of the second concentration discharge unit 42. In the example of FIG. 2, the upstream end of the second discharge pipe 421 is also located at a height corresponding to the second concentration liquid. However, the second discharge pipe 421 extends upward from the upstream end and penetrates the liquid surface of the liquid L1. The second discharge pipe 421 then bends and extends downward outside the processing tank Tk0. In this second concentration discharge unit 42, the control unit 6 can operate the liquid delivery unit 423 while the discharge valve 422 is open to suck the liquid L1 into the upstream end of the second discharge pipe 421. This suction causes the portion of the liquid L1 above the upstream end of the second discharge pipe 421 to flow primarily into the second discharge pipe 421. As a result, the second concentration liquid, which has a relatively high solvent concentration, flows into the second discharge pipe 421. The second concentration liquid is then supplied to the organic solvent recovery unit 5 through the second discharge pipe 421.

[0044] The organic solvent recovery unit 5 includes a dehydrator 62. The dehydrator 62 separates water from the second concentrated solution discharged by the discharge unit 4 to produce a third concentrated solution having a higher solvent concentration than the second concentrated solution. An example of a specific configuration of the organic solvent recovery unit 5 will be described in detail later.

[0045] The control unit 6 controls various components of the substrate processing apparatus 100. The control unit 6 is configured, for example, by a general-purpose computer having electrical circuits. As an example, the control unit 6 is configured to include a CPU (Central Processor Unit) as a central processing unit that performs various arithmetic processing (data processing), a ROM (Read Only Memory) that stores basic programs and the like, a RAM (Random Access Memory) used as a work area when the CPU performs predetermined processing (data processing), a storage device configured by a non-volatile storage device such as a flash memory or a hard disk drive, and a bus line connecting these components to each other. The storage device or RAM may store a program that defines the processing to be performed by the control unit 6. In this case, for example, the CPU may execute the program to control each unit of the substrate processing apparatus 100 via the control unit 6, and the processing defined by the program may be performed in the substrate processing apparatus 100. In other words, the CPU may execute the program to implement a circuit in the control unit 6 that performs the processing defined by the program. However, part or all of the control performed by the control unit 6 (part or all of the circuitry implemented by the control unit 6) may be executed (implemented) by hardware such as a dedicated logic circuit.

[0046] In the substrate processing apparatus 100, as described above, the discharge unit 4 supplies the second concentration liquid having a relatively high solvent concentration to the organic solvent recovery unit 5. Therefore, the organic solvent recovery unit 5 can generate the third concentration liquid from the second concentration liquid in a shorter time and with less energy than when generating the third concentration liquid from the first concentration liquid.

[0047] Hereinafter, a detailed description will be given of an example of a specific configuration and specific operation of the processing unit 1. After that, a detailed description will be given of an example of a specific configuration and specific operation of the organic solvent recovery section 5.

[0048] <Detailed example of processing unit> In the example of FIG. 1, the substrate holding unit 10 includes a plate 11, multiple holding rods 12, and an elevation drive unit 13. The plate 11 has a plate-like shape and is disposed with its thickness direction aligned with the thickness direction of the substrate W (a direction perpendicular to the plane of the paper in FIG. 1). Each holding rod 12 extends along the thickness direction of the substrate W, with its base end connected to the plate 11. The multiple holding rods 12 are located below the multiple substrates W and are disposed at intervals along the circumferential direction of the substrates W. Each holding rod 12 has multiple holding grooves (not shown) formed at intervals in the thickness direction of the substrate W, and a portion of the substrate W is inserted into each holding groove. By inserting the substrates W into these holding grooves, the substrate holding unit 10 holds the multiple substrates W in an upright position.

[0049] The lifting drive unit 13 raises and lowers the plate unit 11, the plurality of holding rods 12, and the plurality of substrates W as a unit. The lifting drive unit 13 includes a drive source such as a motor, and a power transmission unit that transmits power from the drive source to the plate unit 11. The power transmission unit is, for example, a transmission unit such as a ball screw mechanism or a cam mechanism.

[0050] In the example of FIG. 1, the processing unit 1 includes a chamber 1a that forms a processing chamber H1. The internal space of the chamber 1a corresponds to the processing chamber H1. The chamber 1a includes a lid 1b that can be opened and closed at its ceiling. The chamber 1a is provided with an opening / closing drive unit (e.g., a motor) (not shown) that opens and closes the lid 1b. With the lid 1b open, the substrate holder 10 raises and lowers multiple substrates W between a position inside the processing chamber H1 and a position above the processing chamber H1. In the example of FIG. 1, the substrates W are shown positioned inside the processing chamber H1. As described below, the substrate holder 10 loads multiple unprocessed substrates W into the processing chamber H1 and unloads multiple substrates W that have been processed in the processing chamber H1 from the processing chamber H1.

[0051] The processing chamber H1 accommodates a processing tank Tk0. The substrate holder 10 can raise and lower multiple substrates W inside the processing chamber H1 between a immersion position and a drying position, which will be described below. The immersion position is a position where multiple substrates W are immersed in liquid in the processing tank Tk0. In the example of FIG. 1, the substrates W are shown positioned at the immersion position. The drying position is a position where multiple substrates W are above the processing tank Tk0. As will be described later, the processing unit 1 performs pure water processing on substrates W stopped at the immersion position, and performs drying processing on substrates W stopped at the drying position.

[0052] In the example of FIG. 1, the processing unit 1 further includes a pure water supply unit 21, a solvent vapor supply unit 22, and an inert gas supply unit 23. The pure water supply unit 21 supplies pure water (i.e., deionized water) into the processing tank Tk0, causing the pure water to be stored in the processing tank Tk0. In the example of FIG. 1, the pure water supply unit 21 includes a nozzle 211, a supply pipe 212, and a supply valve 213. The nozzle 211 ejects pure water toward the processing tank Tk0. In the example of FIG. 1, the nozzle 211 is provided above the processing tank Tk0 within the processing chamber H1. The nozzle 211 is connected to the downstream end of the supply pipe 212, and the upstream end of the supply pipe 212 is connected to a pure water supply source 214. The supply pipe 212 is a pipe through which pure water flows toward the processing tank Tk0. The supply valve 213 is inserted into the supply pipe 212.

[0053] The control unit 6 opens the supply valve 213, causing the nozzle 211 to eject the pure water toward the processing tank Tk0. This causes the pure water to be stored in the processing tank Tk0. When a sufficient amount of pure water is stored in the processing tank Tk0, the control unit 6 closes the supply valve 213.

[0054] The solvent vapor supply unit 22 supplies organic solvent vapor to the space above the processing tank Tk0 in the processing chamber H1. As described below, the solvent vapor supply unit 22 supplies organic solvent vapor into the processing chamber H1 while multiple substrates W are immersed in the pure water in the processing tank Tk0. Some of the organic solvent vapor reaches the liquid surface in the processing tank Tk0 and condenses on the liquid surface to form a liquid film of the organic solvent. As a result, the liquid L1 is stored in the processing tank Tk0 with the above-mentioned concentration distribution. In other words, the above-mentioned concentration distribution is formed in the liquid L1 in the processing tank Tk0. The liquid film of the organic solvent mainly corresponds to the high-concentration portion L11, and the pure water below the liquid film of the organic solvent mainly corresponds to the low-concentration portion L12.

[0055] 1, the solvent vapor supply unit 22 includes a discharge pipe 221, a supply pipe 222, a supply valve 223, and a solvent vapor generation unit 224. The discharge pipe 221 is provided in the processing chamber H1, and in the example of FIG. 1, it is provided at a position above the processing tank Tk0. The discharge pipe 221 has a discharge port and discharges organic solvent vapor from the discharge port. In the example of FIG. 1, two discharge pipes 221 are provided. The two discharge pipes 221 are aligned horizontally and are provided on opposite sides of the plurality of substrates W in the horizontal direction. As an example, one of the discharge pipes 221 discharges organic solvent vapor toward the other.

[0056] The supply pipe 222 connects the discharge pipe 221 and the solvent vapor generation unit 224. The supply pipe 222 is a pipe that flows the vapor of the organic solvent toward the processing chamber H1. In the example of FIG. 1, the supply pipe 222 branches into two, and the downstream end of each of the branches is connected to the discharge pipe 221. The upstream end of the supply pipe 222 is connected to the solvent vapor generation unit 224.

[0057] The solvent vapor generation unit 224 generates organic solvent vapor and causes the vapor to flow into the supply pipe 222. As shown in FIG. 1, the solvent vapor generation unit 224 includes a supply tank Tk3. The supply tank Tk3 stores a liquid containing an organic solvent. The solvent vapor generation unit 224 includes a heater (not shown) that heats the organic solvent. The heater of the solvent vapor generation unit 224 heats the organic solvent to generate organic solvent vapor, and causes the vapor to flow into the supply pipe 222. The solvent vapor generation unit 224 may also flow a carrier gas into the supply pipe 222 along with the organic solvent vapor. An inert gas can be used as the carrier gas. The inert gas is, for example, a rare gas or nitrogen gas. The rare gas is, for example, argon gas or neon gas.

[0058] The control unit 6 opens the supply valve 223 and causes the solvent vapor generation unit 224 to generate organic solvent vapor. This causes the organic solvent vapor to be discharged from the discharge pipe 221. A portion of the organic solvent vapor discharged from the discharge pipe 221 into the processing chamber H1 reaches the liquid surface of the pure water stored in the processing tank Tk0. This vapor is cooled by the pure water and condenses, forming a liquid film of the organic solvent on the liquid surface of the pure water.

[0059] 1, the supply tank Tk3 is connected to a new liquid supply source 227 through a new liquid pipe 225. That is, the downstream end of the new liquid pipe 225 is connected to the supply tank Tk3, and the upstream end of the new liquid pipe 225 is connected to the new liquid supply source 227. The new liquid supply source 227 is a supply source of an unused organic solvent (e.g., IPA with a concentration of 99.8 wt % or more) that has never been supplied to a substrate W. A new liquid valve 226 is inserted in the new liquid pipe 225.

[0060] The inert gas supply unit 23 supplies an inert gas into the processing chamber H1. In the example of FIG. 1, the inert gas supply unit 23 includes a discharge pipe 231, a supply pipe 232, a supply valve 2331, and a supply valve 2332. Note that in the example of FIG. 1, the discharge pipe 221 is also used for the inert gas supply unit 23. That is, the discharge pipe 221 can also discharge an inert gas. The discharge pipe 231 is provided in the processing chamber H1, and in the example of FIG. 1, the discharge pipe 231 is provided below the discharge pipe 221 and above the processing tank Tk0. The discharge pipe 231 has a discharge port, and discharges the inert gas from the discharge port into the processing chamber H1. In the example of FIG. 1, two discharge pipes 231 are provided. The two discharge pipes 231 are aligned horizontally and are provided on opposite sides of the plurality of substrates W in the horizontal direction. As an example, one of the discharge pipes 231 discharges the inert gas toward the other. As will be described later, the inert gas can be used to dry the substrates W and adjust the pressure inside the processing chamber H1.

[0061] The supply pipe 232 connects each of the discharge pipe 221 and the discharge pipe 231 to an inert gas supply source 234. The supply pipe 232 is a pipe that flows an inert gas toward the processing chamber H1. The upstream end of the supply pipe 232 is connected to the inert gas supply source 234. The supply pipe 232 branches into two branch pipes 2321 and 2322. The downstream end of the branch pipe 2321 is connected to a portion of the supply pipe 222 between the supply valve 223 and the branch point P1. The branch pipe 2322 further branches into two, and the downstream end of each of the branch pipes is connected to the discharge pipe 231. A supply valve 2331 is inserted in the branch pipe 2321, and a supply valve 2332 is inserted in the branch pipe 2322.

[0062] When the control unit 6 opens the supply valve 2331, the inert gas is discharged from the discharge pipe 221. When the control unit 6 opens the supply valve 2332, the inert gas is discharged from the discharge pipe 231.

[0063] In the example of FIG. 1, the processing unit 1 also includes a gas exhaust section 3. The gas exhaust section 3 sucks gas from within the processing chamber H1. By sucking gas, the gas exhaust section 3 can reduce the pressure within the processing chamber H1. The gas exhaust section 3 includes an exhaust pipe 31 and an aspirator 32. The aspirator 32 is connected to the chamber 1a through the exhaust pipe 31. The aspirator 32 is, for example, a pump (a specific example is a water-sealed vacuum pump). In the example of FIG. 1, the upstream end of the exhaust pipe 31 is connected to the bottom of the chamber 1a.

[0064] The control unit 6 activates the aspirator 32, which causes the gas inside the processing chamber H1 to be discharged through the exhaust pipe 31. This can reduce the pressure inside the processing chamber H1.

[0065] When the gas exhaust unit 3 stops suctioning gas and the inert gas supply unit 23 starts supplying inert gas in a reduced pressure state where the pressure inside the processing chamber H1 has dropped, the pressure inside the processing chamber H1 increases. Therefore, the gas exhaust unit 3 and the inert gas supply unit 23 constitute a pressure adjustment unit 30 that adjusts the pressure inside the processing chamber H1.

[0066] The first concentration discharge unit 41 discharges the first concentration solution in the processing tank Tk0. In the example of FIG. 1, the first concentration discharge unit 41 includes a tank valve 410, a first discharge pipe 411, and a discharge valve 412. The tank valve 410 is provided at the bottom of the processing tank Tk0 and switches the bottom of the processing tank Tk0 between open and closed. The upstream end of the first discharge pipe 411 is connected to the bottom of the chamber 1a. In the example of FIG. 1, the upstream end of the first discharge pipe 411 is connected to the bottom of the chamber 1a at a position vertically opposite the tank valve 410. The discharge valve 412 is inserted in the first discharge pipe 411.

[0067] After the second concentration discharge unit 42 discharges the second concentration liquid, the control unit 6 opens the tank valve 410 and the discharge valve 412. This causes the first concentration liquid to flow out from the bottom of the processing tank Tk0 and into the upstream end of the first discharge pipe 411. The first concentration liquid is discharged to the outside through the first discharge pipe 411.

[0068] Although different from FIG. 1, the upstream portion of the first exhaust pipe 411 and the upstream portion of the exhaust pipe 31 may be the same. For example, an aspirator 32 may be inserted into the first exhaust pipe 411 of FIG. 1 (see also FIG. 15). In this case, the first exhaust pipe 411 also functions as the exhaust pipe 31 that exhausts gas. A gas-liquid separator may be provided in the first exhaust pipe 411 downstream of the aspirator 32. The gas from the processing chamber H1 and the first concentration liquid from the processing tank Tk0 that flow into the first exhaust pipe 411 are sent downstream by the aspirator 32 and flow into the gas-liquid separator. The gas-liquid separator separates the gas and the first concentration liquid, and each is discharged to the outside through separate exhaust pipes.

[0069] <Example of operation of processing unit 1> 3 is a flowchart showing an example of processing of a substrate W by the processing unit 1 according to the first embodiment. This processing is performed by the control unit 6 controlling various components of the substrate processing apparatus 100. FIGS. 4 and 5 are diagrams showing an example of the change over time in the state of the processing unit 1. In FIGS. 4 and 5, open valves are indicated by blackened valves. Initially, the control unit 6 causes the inert gas supply unit 23 to discharge inert gas from the discharge pipe 221.

[0070] First, the processing unit 1 performs pure water processing on multiple substrates W (step S1: pure water process). Specifically, the control unit 6 controls the pure water supply unit 21 to supply pure water to the processing tank Tk0, and controls the substrate holder 10 to lower the multiple substrates W to the immersion position, immersing the multiple substrates W in the pure water. For example, the control unit 6 first opens the supply valve 213 to store pure water in the processing tank Tk0. Next, the control unit 6 opens the lid 1b and controls the substrate holder 10 to lower the multiple substrates W from a position above the processing chamber H1 to the immersion position. As a result, the multiple substrates W are immersed in the pure water in the processing tank Tk0, as shown first from the left in FIG. 4. Then, the control unit 6 closes the lid 1b.

[0071] Here, it is assumed that chemicals or particles have been adhered to the main surface of each substrate W due to pretreatment. When multiple substrates W are immersed in pure water, the chemicals or particles adhering to the multiple substrates W move into the pure water over time. As a result, the chemicals or particles are gradually removed from the substrates W.

[0072] Also, as an example, the control unit 6 causes the gas exhaust unit 3 to exhaust the gas inside the processing chamber H1. Specifically, the control unit 6 activates the aspirator 32. As a result, the gas inside the processing chamber H1 is supplied to the aspirator 32.

[0073] The processing unit 1 immerses the substrate W until the chemical solution or particles are sufficiently removed from the substrate W, that is, until the pure water processing is sufficiently performed. For example, the control unit 6 may determine that the chemical solution or particles are sufficiently removed from the substrate W when the time elapsed since the substrate W reached the immersion position is equal to or longer than a predetermined pure water reference time. The pure water reference time is set to be equal to or longer than the time required to sufficiently remove the chemical solution or particles from the substrate W, for example, about 30 to 60 seconds.

[0074] After the pure water treatment is sufficiently performed, the treatment unit 1 changes the state of the main surface of the substrate W from a state immersed in pure water to a state in which an organic solvent is attached, by a treatment described below (step S2: solvent replacement step). Here, the organic solvent has higher volatility than pure water. The organic solvent may have a lower surface tension than pure water. The organic solvent is, for example, IPA.

[0075] First, while multiple substrates W are immersed in the pure water in the processing tank Tk0, the control unit 6 controls the solvent vapor supply unit 22 to supply organic solvent vapor into the processing chamber H1. Specifically, as shown second from the left in FIG. 4, the control unit 6 opens the supply valve 223 and activates the solvent vapor generator 224. This causes organic solvent vapor to be discharged from the discharge pipe 221 into the processing chamber H1. This vapor moves downward by the suction of the aspirator 32. Some of the organic solvent vapor reaches the liquid surface of the pure water in the processing tank Tk0 and condenses. As a result, a liquid film of the organic solvent is formed on the liquid surface of the pure water in the processing tank Tk0. In other words, a liquid L1 containing water and organic solvent is stored in the processing tank Tk0, and a high-concentration portion L11 and a low-concentration portion L12 are formed in the liquid L1.

[0076] 4, the control unit 6 causes the gas exhaust unit 3 to temporarily stop suctioning the gas from inside the processing chamber H1. That is, the control unit 6 stops the aspirator 32.

[0077] When a liquid film of the organic solvent (e.g., high-concentration portion L11) has been formed with a sufficient thickness, the control unit 6 causes the substrate holding unit 10 to raise the plurality of substrates W to the drying position. Specifically, the control unit 6 may cause the substrate holding unit 10 to raise the plurality of substrates W when the elapsed time from the start of the supply of the organic solvent vapor becomes equal to or longer than a predetermined film reference time. The film reference time is set to be equal to or longer than the time required for a liquid film of the organic solvent to be formed with a sufficient thickness, for example, about 5 to 10 seconds.

[0078] As the substrates W ascend, they pass through the high-concentration region L11. This passage causes the organic solvent to adhere to the main surfaces of the substrates W. Therefore, after the substrates W ascend to the drying position, the organic solvent adheres to most of the main surfaces of each substrate W. However, pure water may remain on the main surfaces of the substrates W immediately after they reach the drying position. In this case, as shown in the fourth figure from the left in FIG. 4, the processing unit 1 may leave the substrates W in the drying position for a predetermined replacement time. In the example shown in FIG. 4, the discharge pipe 221 continues to discharge organic solvent vapor toward the substrates W. Some of the organic solvent vapor in the processing chamber H1 condenses on the main surfaces of the substrates W, replacing the organic solvent with residual pure water, which then flows down from the substrates W. The replacement time is set to be at least the time required for sufficient replacement of the pure water with the organic solvent, for example, approximately 10 to 50 seconds. Because the volatility of the organic solvent is higher than that of water, the substrates W can be dried quickly, as described below.

[0079] When the pure water on the main surfaces of the substrates W has been sufficiently replaced with the organic solvent, the processing unit 1 dries the substrates W (step S3: drying step). Specifically, the control unit 6 controls the solvent vapor supply unit 22 to stop supplying the organic solvent vapor, controls the inert gas supply unit 23 to supply the inert gas, and controls the gas exhaust unit 3 to suck the gas from the processing chamber H1. For example, as shown in the first position from the left in FIG. 5, the control unit 6 closes the supply valve 223 and opens the supply valve 2331. This causes the inert gas to be discharged from the discharge pipe 221 into the processing chamber H1. In the example of FIG. 5, the discharge pipe 221 is horizontally aligned with the substrate W positioned at the stopped position and discharges the inert gas toward the substrate W. The inert gas supply unit 23 may supply a high-temperature inert gas. For example, a heater may be provided in the supply pipe 232 of the inert gas supply unit 23.

[0080] The control unit 6 also activates the aspirator 32. As a result, the gas inside the processing chamber H1 is exhausted through the exhaust pipe 31. The gas exhaust unit 3 adjusts the pressure inside the processing chamber H1 to a first pressure value suitable for drying the substrates W. That is, the processing unit 1 dries multiple substrates W in a state in which the pressure inside the processing chamber H1 is reduced to the first pressure value. This promotes evaporation of the organic solvent. That is, the processing unit 1 can quickly dry the substrates W.

[0081] When the substrate W is sufficiently dried, the processing unit 1 increases the pressure in the processing chamber H1 (step S4: pressure increasing step). For example, the control unit 6 may determine that the substrate W is sufficiently dried when the time elapsed since the start of the supply of the inert gas reaches or exceeds a predetermined drying reference time. The drying reference time is set to be equal to or longer than the time required to dry the substrate W, for example, approximately 40 to 80 seconds.

[0082] The control unit 6 controls the pressure adjustment unit 30 to increase the pressure in the processing chamber H1. Specifically, the control unit 6 controls the gas exhaust unit 3 to stop suction of gas in the processing chamber H1. The control unit 6 may also control the inert gas supply unit 23 to increase the flow rate of the inert gas. For example, as shown second from the left in FIG. 5, the control unit 6 also opens the supply valve 2332. This causes the inert gas to be supplied into the processing chamber H1 from both the discharge pipe 221 and the discharge pipe 231. The control unit 6 controls the inert gas supply unit 23 to supply the inert gas so that the pressure in the processing chamber H1 becomes a second pressure value that is greater than the first pressure value. The second pressure value is a value closer to standard atmospheric pressure than the first pressure value.

[0083] Next, the control unit 6 opens the lid 1b and causes the substrate holder 10 to raise the plurality of substrates W to a position above the processing chamber H1 (step S5: unloading step). As a result, the plurality of processed substrates W are unloaded from the processing chamber H1, as shown third from the left in FIG.

[0084] Next, the second concentration discharge unit 42 discharges the second concentration liquid from the processing tank Tk0 and supplies the second concentration liquid to the organic solvent recovery unit 5 (Step S6: second concentration liquid discharge step). That is, the discharge unit 4 discharges the second concentration liquid while the substrates W are in a non-immersed state, positioned above the processing tank Tk0. Specifically, as shown third from the left in FIG. 5 , the control unit 6 opens the discharge valve 422. If a liquid delivery unit 423 is provided, the control unit 6 operates the liquid delivery unit 423. As a result, the liquid L1 that has flowed into the upstream end of the second discharge pipe 421 in the processing tank Tk0 is supplied to the organic solvent recovery unit 5 through the second discharge pipe 421 as the second concentration liquid. The upstream end of the second discharge pipe 421 is generally the portion of the liquid L1 that is above the upstream end. In other words, the portion of the liquid L1 below the upstream end of the second discharge pipe 421 remains in the treatment tank Tk0 without flowing much into the second discharge pipe 421. That is, the discharge unit 4 (specifically, the second concentration discharge unit 42) supplies the second concentration liquid to the organic solvent recovery unit 5, avoiding at least a portion of the first concentration liquid in the treatment tank Tk0.

[0085] When the second concentration liquid has been sufficiently discharged, the second concentration discharge unit 42 stops discharging the second concentration liquid. For example, the control unit 6 closes the discharge valve 412 when the elapsed time from the time when the discharge valve 422 was opened becomes equal to or exceeds a predetermined second discharge reference time. The second discharge reference time is set in advance to be equal to or longer than the time required to discharge the second concentration liquid. The control unit 6 stops the liquid delivery unit 423 as necessary. By discharging the second concentration liquid, substantially only the first concentration liquid remains in the processing tank Tk0.

[0086] Next, the first concentration discharge unit 41 discharges the first concentration liquid from the processing tank Tk0 (step S7: first concentration liquid discharge step). Specifically, as shown in the fourth position from the left in FIG. 5, the control unit 6 opens the tank valve 410 and the discharge valve 412. As a result, the first concentration liquid flows out into the chamber 1a through the bottom of the processing tank Tk0 (tank valve 410) and into the upstream end of the first discharge pipe 411 connected to the bottom of the chamber 1a. The first concentration liquid is discharged to the outside through the first discharge pipe 411. When the first concentration liquid has been sufficiently discharged, the first concentration discharge unit 41 stops discharging the first concentration liquid. For example, the control unit 6 closes the tank valve 410 and the discharge valve 412 when the elapsed time from the time the tank valve 410 and the discharge valve 412 were opened becomes equal to or exceeds a predetermined first discharge reference time. The first discharge reference time is set in advance to be equal to or longer than the time required to discharge the first concentration liquid.

[0087] As described above, the processing unit 1 can perform deionized water processing on multiple substrates W. Moreover, in the above example, the processing unit 1 condenses the vapor of the organic solvent on the surface of the deionized water in the processing tank Tk0, forming a liquid film of the organic solvent on the surface of the deionized water. Therefore, a concentration distribution in which the solvent concentration is higher at the upper side is formed in the liquid L1 in the processing tank Tk0. That is, while the substrate W is immersed in the deionized water in the processing tank Tk0, high-concentration portions L11 and low-concentration portions L12 are formed in the liquid L1 in the processing tank Tk0. Therefore, after processing the substrate W, almost no waiting time is required for the high-concentration portions L11 and low-concentration portions L12 to form. Therefore, the second-concentration liquid can be discharged from the processing tank Tk0 at an earlier timing after the processing of the substrate W is completed. As a result, the discharge of the first-concentration liquid can also be completed at an earlier timing. Therefore, the processing unit 1 can process the next multiple substrates W at an earlier timing. That is, the throughput of the processing unit 1 can be improved.

[0088] In the above example, the second concentration discharge unit 42 discharges the second concentration liquid from the processing tank Tk0 (step S6) after the pressure adjustment unit 30 increases the pressure in the processing chamber H1 (step S4). That is, the control unit 6 controls the pressure adjustment unit 30 to adjust the pressure in the processing chamber H1 to the second pressure value, and then controls the discharge unit 4 to discharge the second concentration liquid from the processing tank Tk0. This allows the gas in the processing chamber H1 to apply a relatively high pressure to the liquid surface in the processing tank Tk0 when the second concentration liquid is discharged. This allows the second concentration discharge unit 42 to discharge the second concentration liquid more quickly.

[0089] It should be noted that the second concentration discharge unit 42 does not necessarily have to start discharging the second concentration liquid from the processing tank Tk0 after the substrate W is unloaded (step S5). The second concentration discharge unit 42 may start discharging the second concentration liquid from the processing tank Tk0 before the substrate W is unloaded. As an example, the second concentration discharge unit 42 may start discharging the second concentration liquid when the pressure in the processing chamber H1 reaches or exceeds a predetermined pressure reference value. For example, the pressure reference value is set in advance to a value greater than the first pressure value.

[0090] <Organic solvent recovery section 5> Next, an example of the organic solvent recovery section 5 will be described. The organic solvent recovery section 5 can be provided below the floor on which the processing unit 1 is provided. FIG. 6 is a diagram schematically showing an example of the organic solvent recovery section 5. In the example of FIG. 6, the organic solvent recovery section 5 includes a recovery tank Tk1, a dehydration circulation section 60, a purification circulation section 80, and a liquid delivery pipe 85. The second concentrated liquid flows into the recovery tank Tk1 through a second discharge pipe 421. In other words, the second concentrated liquid is recovered in the recovery tank Tk1.

[0091] The dehydration circulation unit 60 includes a dehydration circulation pipe 61 and a dehydrator 62. The dehydration circulation pipe 61 is connected to the recovery tank Tk1. The dehydration circulation pipe 61 is a pipe that returns the second concentration solution from the recovery tank Tk1 to the recovery tank Tk1.

[0092] A dehydration-side liquid pump 63, a first switching valve 641, and a second switching valve 642 are inserted in the dehydration circulation pipe 61. As an example, the dehydration-side liquid pump 63 is provided upstream of a dehydrator 62 (described later), the first switching valve 641 is provided downstream of the dehydrator 62, and the second switching valve 642 is provided upstream of the dehydration-side liquid pump 63.

[0093] The dehydrator 62 is inserted into the dehydrator circulation pipe 61. Therefore, the second concentration liquid flows into the dehydrator 62. The dehydrator 62 separates water from the second concentration liquid and sends the water to the separation and discharge pipe 65. The separated second concentration liquid continues to circulate through the dehydrator circulation pipe 61. Due to this dehydration, the organic solvent concentration (hereinafter referred to as the solvent concentration) of the second concentration liquid immediately after the dehydrator 62 in the dehydrator circulation pipe 61 becomes higher than the solvent concentration of the second concentration liquid immediately before the dehydrator 62. Because the dehydrator circulation unit 60 circulates the second concentration liquid through the dehydrator circulation pipe 61, the second concentration liquid continues to flow into the dehydrator 62. Therefore, the dehydrator 62 continues to separate water from the second concentration liquid. As a result, the solvent concentration of the circulating second concentration liquid increases over time. Hereinafter, the second concentration liquid whose solvent concentration has been increased to a predetermined solvent reference value or higher will be referred to as the third concentration liquid. The dehydration circulation unit 60 generates a third concentrated solution by circulating the second concentrated solution.

[0094] The dehydrator 62 may be, for example, a distiller, an atomization separator, or a membrane separator. In the example of FIG. 5, the dehydrator 62 includes a membrane separator 621. The membrane separator 621 includes a first path 621a, a second path 621b, and a separation membrane 621c. The first path 621a is inserted in the dehydration circulation piping 61 and constitutes a part of the dehydration circulation path of the dehydration circulation unit 60. Therefore, the second concentration liquid passes through the first path 621a. The separation membrane 621c separates the first path 621a and the second path 621b. The separation membrane 621c is a membrane that allows water in the second concentration liquid to pass through and almost completely blocks the organic solvent. A portion of the water in the second concentration liquid that flows into the first path 621a passes through the separation membrane 621c and flows into the second path 621b.

[0095] The separation membrane 621c may be a zeolite membrane, an organic separation membrane, or a CNT (carbon nanotube) separation membrane. The zeolite membrane is, for example, a tetrahedral (SiO4) 4- and (AlO4) 5- The separation membrane 621c has a crystalline structure in which carbon nanotubes are interconnected. The organic separation membrane is, for example, an organic membrane such as polyvinyl alcohol, chitosan, or polyimide. The CNT separation membrane is, for example, a membrane obtained by adding carbon nanotubes to a membrane such as polyamide. Alternatively, a two-dimensional material may be used as the material for the separation membrane 621c. The two-dimensional material is a material composed of one atomic layer, such as molybdenum sulfide (MoS2), or a composite atomic layer compound of an early transition metal (such as titanium or vanadium) and a light element (carbon or nitrogen). Alternatively, a metal organic framework (MOF) material or a carbon material (such as graphene or graphene oxide) may be used as the material for the separation membrane 621c. In this example, a zeolite membrane is used as the separation membrane 621c.

[0096] The second path 621b is connected to the upstream end of a separation discharge pipe 65. The water separated from the second concentrated solution is discharged to the outside (for example, a wastewater treatment section of a factory facility) through the separation discharge pipe 65. A decompression pump for decompressing the second path 621b may be provided in the separation discharge pipe 65. As shown in FIG. 5, a discharge valve 66 is inserted in the separation discharge pipe 65.

[0097] 5, the organic solvent recovery unit 5 is provided with a purification tank Tk2. The purification tank Tk2 is connected to the recovery tank Tk1 through a first liquid feed pipe 71, and receives the third concentration solution from the recovery tank Tk1 through the first liquid feed pipe 71. As an example, the downstream end of the first liquid feed pipe 71 is connected to the purification tank Tk2, and the upstream end of the first liquid feed pipe 71 is connected to the dehydration circulation pipe 61. The upstream end of the first liquid feed pipe 71 is connected to the dehydration circulation pipe 61 at a position between the dehydration-side liquid feed pump 63 and the first switching valve 641. A first liquid feed valve 72 is inserted in the first liquid feed pipe 71.

[0098] The purification circulation unit 80 includes a purification circulation pipe 81 and a filter 82. The purification circulation pipe 81 is a circulation pipe that circulates the third concentrated solution. In the example of FIG. 5, the purification circulation pipe 81 is connected to the purification tank Tk2. The purification circulation pipe 81 is a pipe that returns the third concentrated solution from the purification tank Tk2 to the purification tank Tk2.

[0099] A purification-side liquid pump 83 and a switching valve 84 are inserted in the purification circulation pipe 81. As an example, the purification-side liquid pump 83 is provided at a position upstream of the filter 82, and the switching valve 84 is provided at a position downstream of the filter 82.

[0100] The filter 82 is inserted into the purification circulation pipe 81. Therefore, the third concentration liquid flows into the filter 82. The filter 82 captures impurities in the third concentration liquid. Due to this capture, the impurity content in the third concentration liquid immediately before the filter 82 becomes lower than the impurity content in the third concentration liquid immediately after the filter 82. Since the purification circulation unit 80 circulates the third concentration liquid through the purification circulation pipe 81, the third concentration liquid continues to flow into the filter 82. Therefore, the filter 82 continues to capture impurities from the third concentration liquid. As a result, the impurity content of the circulating third concentration liquid decreases over time. In other words, the cleanliness of the third concentration liquid increases over time.

[0101] The second liquid supply pipe 85 is a pipe that flows the third concentration liquid, the impurity content of which has been reduced by the purification circulation unit 80, toward the supply tank Tk3. As an example, the downstream end of the second liquid supply pipe 85 is connected to the supply tank Tk3, and the upstream end of the second liquid supply pipe 85 is connected to the purification circulation pipe 81.

[0102] As described above, the organic solvent recovery unit 5 increases the solvent concentration of the second concentration liquid discharged from the processing unit 1 to generate a third concentration liquid, and then reduces the impurity content of the third concentration liquid. The third concentration liquid with the reduced impurity content is reused in the processing unit 1. In other words, the substrate processing apparatus 100 reuses the organic solvent in the second concentration liquid discharged from the processing unit 1. This makes it possible to reduce the amount of organic solvent discarded, and to use the organic solvent more effectively. In other words, the organic solvent recovery unit 5 contributes to liquid conservation.

[0103] Moreover, in the above example, the dehydrator 62 includes a membrane separator 621. The membrane separator 621 can separate water from the second concentrate with low energy.

[0104] <Concentration of the second concentrated solution> The dehydrator 62 may have a solvent concentration range. The range is the range within which the solvent concentration of the liquid flowing into the dehydrator 62 can be controlled. For example, if a fluid having a solvent concentration below the lower limit of the range flows into the dehydrator 62, the dehydrator 62 may malfunction. For example, the dehydrator 62 may not be able to sufficiently separate water from the fluid. If the separation membrane 621c is a zeolite membrane, the lower limit may be approximately 50 wt%. For example, if a first concentration liquid with a low solvent concentration flows into the zeolite membrane, the zeolite membrane may be damaged.

[0105] The solvent concentration of the second concentration liquid may be equal to or greater than the lower limit of the applicable range of the separation membrane 621c. In other words, the upstream end of the discharge pipe 421 may be located at a height position where the average solvent concentration of the second concentration liquid flowing into the upstream end is equal to or greater than the lower limit. This allows the recovery tank Tk1 to store the second concentration liquid having a solvent concentration equal to or greater than the lower limit. Therefore, the dehydrator 62 is supplied with the second concentration liquid having a solvent concentration within the applicable range.

[0106] The solvent concentration of the second concentration liquid flowing into the second discharge pipe 421 is not necessarily constant over time. For example, if the upstream end of the second discharge pipe 421 is located at a slightly lower position, a second concentration liquid with a slightly lower solvent concentration will initially flow in, and then a second concentration liquid with a higher solvent concentration will flow in. The solvent concentration of the second concentration liquid supplied to the organic solvent recovery unit 5 can be the solvent concentration when the total amount of liquid L1 flowing into the second discharge pipe 421 is made uniform.

[0107] Although the lower limit of the applicable range of the separation membrane 621c is relatively high as described above, the discharge unit 4 supplies the second concentration liquid with a high solvent concentration to the organic solvent recovery unit 5. Therefore, the separation membrane 621c can appropriately separate water from the second concentration liquid. In other words, the separation membrane 621c, which can separate water with low energy, can be appropriately used.

[0108] <Second embodiment> 7 is a diagram schematically illustrating an example of a substrate processing apparatus 100 according to a first example of the second embodiment. The substrate processing apparatus 100 according to the first example of the second embodiment differs from the first embodiment in the specific configuration of the discharge unit 4.

[0109] The discharge unit 4 includes a first discharge pipe 411, a second discharge pipe 421, and a switching valve unit 43. In the example of FIG. 7, the first discharge pipe 411 includes a common discharge pipe 400 and a first branch pipe 401, and the second discharge pipe 421 includes the common discharge pipe 400 and a second branch pipe 402. In other words, the common discharge pipe 400 serves as both the first discharge pipe 411 and the second discharge pipe 421. Liquid L1 flows from the bottom of the processing tank Tk0 into the upstream end of the common discharge pipe 400 (i.e., the upstream ends of the first discharge pipe 411 and the second discharge pipe 421). It can be said that the first discharge pipe 411 and the second discharge pipe 421 are connected to the bottom of the processing tank Tk0. In the example of FIG. 7, the upstream end of the common discharge pipe 400 is connected to the bottom of the chamber 1a at a position vertically opposite the tank valve 410. The downstream end of the common discharge pipe 400 is connected to the upstream ends of a first branch pipe 401 and a second branch pipe 402. The downstream end of the first branch pipe 401 is connected to, for example, the outside, and the downstream end of the second branch pipe 402 is connected to an organic solvent recovery section 5 (for example, a recovery tank Tk1).

[0110] The switching valve unit 43 switches between a first state in which the liquid L1 from the processing tank Tk0 flows into the first discharge pipe 411, and a second state in which the liquid L1 from the processing tank Tk0 flows into the second discharge pipe 421. In the example of FIG. 7, the switching valve unit 43 includes a discharge valve 412 and a discharge valve 422. The discharge valve 412 is inserted in the first branch pipe 401, and the discharge valve 422 is inserted in the second branch pipe 402.

[0111] With the liquid L1 stored in the processing tank Tk0, the control unit 6 first causes the switching valve unit 43 to select the first state. Specifically, the control unit 6 closes the discharge valve 422 and opens the tank valve 410 and the discharge valve 412. This causes the lower portion of the liquid L1 in the processing tank Tk0 (i.e., the first concentration liquid) to flow out of the tank valve 410 and be discharged to the outside through the first discharge pipe 411. As a result, the volume of the low concentration portion L12 in the processing tank Tk0 decreases over time. On the other hand, although this discharge causes the high concentration portion L11 in the processing tank Tk0 to decrease over time, the volume of the high concentration portion L11 remains almost constant. As a result, the average value of the solvent concentration of the liquid L1 in the processing tank Tk0 increases over time. Therefore, the average value of the solvent concentration of the liquid L1 in the processing tank Tk0 will eventually reach or exceed a predetermined concentration reference value.

[0112] When the solvent concentration (average value) of the liquid L1 in the processing tank Tk0 becomes equal to or greater than the concentration reference value, the control unit 6 causes the switching valve unit 43 to select the second state. Specifically, the control unit 6 closes the discharge valve 412 and opens the discharge valve 422. As a result, the second concentration liquid in the processing tank Tk0 is supplied to the organic solvent recovery unit 5 through the second discharge pipe 421.

[0113] A condition using time, for example, may be applied as a condition for switching from the first state to the second state by the switching valve unit 43. For example, the control unit 6 may cause the switching valve unit 43 to switch from the first state to the second state when the elapsed time from the start of discharge of the liquid L1 in the processing tank Tk0 becomes equal to or longer than a predetermined switching reference time. The switching reference time may be set in advance as the time required for the solvent concentration (average value) of the liquid L1 in the processing tank Tk0 to reach the concentration reference value.

[0114] Alternatively, a condition using the amount of liquid L1 stored in the processing tank Tk0 may be applied as the switching condition. The amount of stored liquid L1 may be detected by a sensor (e.g., a liquid level sensor) not shown. The control unit 6 may cause the switching valve unit 43 to switch from the first state to the second state when the amount of stored liquid detected by the sensor becomes equal to or less than a predetermined storage reference value. The storage reference value may be set in advance to the amount of stored liquid when the solvent concentration (average value) of the liquid L1 in the processing tank Tk0 becomes the concentration reference value.

[0115] <Example of operation of processing unit 1> Fig. 8 is a flowchart showing an example of the operation of the processing unit 1 according to the first example of the second embodiment. Steps S11 to S15 are the same as steps S1 to S5 of the first embodiment, respectively. In the example of Fig. 8, after step S15 (discharging step) is completed, the discharge unit 4 first discharges the first concentration liquid from the processing tank Tk0 (step S16: first concentration liquid discharging step), and then discharges the second concentration liquid from the processing tank Tk0 (step S17: second concentration liquid discharging step). Fig. 9 is a diagram showing an example of the change over time in the state of the processing unit 1 in steps S16 and S17.

[0116] First, the switching valve unit 43 selects the first state. Specifically, as shown first from the left in Fig. 9 , the control unit 6 closes the discharge valve 422 and opens the tank valve 410 and the discharge valve 412. This causes the lower portion of the liquid L1 in the processing tank Tk0 (i.e., the first concentration liquid) to flow out from the tank valve 410 and be discharged to the outside through the first discharge pipe 411.

[0117] Due to this discharge, the solvent concentration (average value) of the liquid L1 in the processing tank Tk0 increases over time. When the solvent concentration (average value) of the liquid L1 in the processing tank Tk0 becomes equal to or greater than the concentration reference value, the control unit 6 causes the switching valve unit 43 to select the second state (step S17). Specifically, as shown second from the left in FIG. 9, the control unit 6 closes the discharge valve 412 and opens the discharge valve 422. As a result, the second concentration liquid in the processing tank Tk0 is supplied to the organic solvent recovery unit 5 through the second discharge pipe 421.

[0118] As described above, the discharge unit 4 can separately discharge the first concentration liquid and the second concentration liquid from the bottom of the processing tank Tk0. Then, the discharge unit 4 supplies the second concentration liquid to the organic solvent recovery unit 5, avoiding the first concentration liquid. Therefore, similar to the first embodiment, the organic solvent recovery unit 5 can produce the third concentration liquid in a short time with low energy.

[0119] In the first example of the second embodiment, the liquid L1 remaining in the processing tank Tk0 after the first concentration liquid is discharged (step S16) is supplied to the organic solvent recovery unit 5 as the second concentration liquid (step S17). In other words, the solvent concentration of the second concentration liquid depends on the amount of liquid L1 (first concentration liquid) discharged through the first discharge pipe 411. The greater the amount of the first concentration liquid discharged, the higher the solvent concentration of the second concentration liquid. Therefore, the solvent concentration of the second concentration liquid can be easily adjusted by adjusting the timing at which the switching valve unit 43 switches from the first state to the second state. For example, the lower limit of the applicable range of the dehydrator 62 may change due to replacement or aging of the dehydrator 62. Even in this case, the discharge unit 4 can easily supply the second concentration liquid having a solvent concentration equal to or higher than the lower limit of the applicable range to the organic solvent recovery unit 5 by adjusting the switching timing of the switching valve unit 43.

[0120] Incidentally, the flow rate of the liquid L1 passing through the tank valve 410 may be greater than the flow rate of the liquid L1 flowing into the upstream end of the common discharge pipe 400. In this case, a portion of the liquid L1 flowing out of the tank valve 410 accumulates at the bottom of the chamber 1a and flows into the upstream end of the common discharge pipe 400. When the switching valve unit 43 switches from the first state to the second state while the first concentration liquid accumulates at the bottom of the chamber 1a, the second concentration liquid from the bottom of the processing tank Tk0 merges with the first concentration liquid at the bottom of the chamber 1a. This merger reduces the solvent concentration of the second concentration liquid.

[0121] Therefore, the switching valve unit 43 may temporarily close the tank valve 410 when switching from the first state to the second state. FIG. 10 is a diagram showing an example of the time change of the processing unit 1 discharging the liquid L1 from the processing tank Tk0. As shown in the first diagram from the left in FIG. 10, the discharge unit 4 first discharges the first concentration liquid from the processing tank Tk0. Specifically, the control unit 6 closes the discharge valve 422 and opens the tank valve 410 and the discharge valve 412. Here, the outflow rate of the liquid L1 from the bottom of the processing tank Tk0 (tank valve 410) is greater than the inflow rate of the liquid L1 to the upstream end of the first discharge pipe 411. For example, the flow path area of ​​the tank valve 410 is greater than the flow path area of ​​the upstream end of the first discharge pipe 411. Therefore, as shown in the first diagram from the left in FIG. 10, the first concentration liquid accumulates at the bottom of the chamber 1a and is discharged through the first discharge pipe 411.

[0122] When the solvent concentration (average value) of the liquid L1 in the processing tank Tk0 becomes equal to or greater than the concentration reference value, the control unit 6 causes the switching valve unit 43 to stop discharging from the processing tank Tk0. Specifically, as shown second from the left in Fig. 10, the control unit 6 closes the tank valve 410. As a result, the second concentration liquid is not discharged from the processing tank Tk0, and the first concentration liquid accumulated at the bottom of the chamber 1a is discharged through the first discharge pipe 411.

[0123] When the first concentration solution in chamber 1a has been completely discharged, control unit 6 causes switching valve unit 43 to select the second state. For example, control unit 6 may determine that the discharge of the first concentration solution in chamber 1a has been completed when the time elapsed since tank valve 410 was closed is equal to or greater than a predetermined discharge reference time. The discharge reference time is set in advance to be equal to or greater than the time required to discharge the first concentration solution in chamber 1a, for example.

[0124] 10 , the control unit 6 closes the discharge valve 412 and opens the tank valve 410 and the discharge valve 422. As a result, the second concentrated solution in the processing tank Tk0 is supplied to the organic solvent recovery unit 5 through the tank valve 410 and the second discharge pipe 421.

[0125] As described above, the switching valve unit 43 switches from the first state to the interrupted state in which the tank valve 410 is closed, and then to the second state. Therefore, the discharge unit 4 can discharge the second concentration liquid from the bottom of the processing tank Tk0 while the first concentration liquid in the chamber 1a is almost completely discharged. Therefore, the discharge unit 4 can supply the second concentration liquid to the organic solvent recovery unit 5 while suppressing a decrease in the solvent concentration of the second concentration liquid.

[0126] 11 is a diagram schematically illustrating an example of a substrate processing apparatus 100 according to a second example of the second embodiment. The substrate processing apparatus 100 according to the second example differs from the substrate processing apparatus 100 according to the first example in the configuration of the processing unit 1. In the second example, the processing unit 1 is not provided with a discharge pipe 231. In addition, in the second example, the downstream end of the supply pipe 232 of the inert gas supply unit 23 is connected to the supply pipe 222 at a position P2 downstream of the supply valve 223 of the solvent vapor supply unit 22. A supply valve 233 is interposed in the supply pipe 232. In addition, as an example, the discharge direction of the discharge pipe 221 differs from that of the first example. As an example, the discharge direction of the discharge pipe 221 is vertically upward.

[0127] Fig. 12 is a flowchart showing an example of the operation of the substrate processing apparatus 100 according to the second example. Fig. 13 and Fig. 14 are diagrams showing an example of the change over time in the state of the processing unit 1 according to the second example. Initially, it is assumed that the control unit 6 causes the inert gas supply unit 23 to supply the inert gas.

[0128] Similar to step S1, the processing unit 1 performs pure water processing on the plurality of substrates W (step S21: pure water process). Specifically, the control unit 6 controls the pure water supply unit 21 to supply pure water to the processing tank Tk0, and controls the substrate holder 10 to lower the plurality of substrates W to the immersion position, thereby immersing the plurality of substrates W in the pure water. As a result, the plurality of substrates W are immersed in the pure water in the processing tank Tk0, as shown first from the left in FIG. 13. Then, the control unit 6 closes the lid 1b.

[0129] Once the pure water treatment has been sufficiently performed, the treatment unit 1 changes the state of the main surface of the substrate W from a state immersed in pure water to a state in which the organic solvent is attached, by a process described below (step S22: solvent replacement process). First, the control unit 6 controls the solvent vapor supply unit 22 to supply organic solvent vapor into the treatment chamber H1. Specifically, as shown second from the left in FIG. 13, the control unit 6 opens the supply valve 223 and activates the solvent vapor generation unit 224. This causes the organic solvent vapor to be discharged from the discharge pipe 221 into the treatment chamber H1. As an example, the discharge pipe 221 discharges the organic solvent vapor vertically upward.

[0130] Here, the control unit 6 activates the aspirator 32. The steam discharged from the discharge pipe 221 is sucked by the aspirator 32, making a U-turn and moving downward within the processing chamber H1. Some of this steam reaches the liquid surface of the pure water in the processing tank Tk0 and condenses. As a result, a liquid film of the organic solvent is formed on the liquid surface of the pure water in the processing tank Tk0. In other words, a high-concentration portion L11 and a low-concentration portion L12 are formed in the liquid L1 in the processing tank Tk0.

[0131] Once a sufficient thickness of liquid film has been formed, the substrate holding unit 10 raises the multiple substrates W. Specifically, as shown third from the left in FIG. 13, the control unit 6 causes the substrate holding unit 10 to raise the substrates W. During this raising, the main surfaces of the substrates W pass through the liquid film of organic solvent. As a result, the organic solvent adheres to the main surfaces of the substrates W. When the multiple substrates W reach the drying position, the substrate holding unit 10 stops the multiple substrates W at the drying position. The solvent vapor supply unit 22 continues to supply organic solvent vapor into the processing chamber H1 even after the multiple substrates W have stopped. This allows the pure water remaining on the main surfaces of the substrates W to be replaced with the organic solvent.

[0132] 13, the discharge unit 4 discharges the liquid L1 from the processing tank Tk0 in parallel with the lifting of the substrate W. Specifically, the switching valve unit 43 selects the first state. That is, the control unit 6 closes the discharge valve 422 and opens the tank valve 410 and the discharge valve 412. As a result, the liquid L1 (here, the first concentration liquid) in the processing tank Tk0 flows down the tank valve 410 and is discharged through the first discharge pipe 411. This discharge causes the high concentration portion L11 to descend. When the lifting of the substrate W and the discharge of the liquid L1 are performed in parallel in this way, the substrate W can be pulled up from the liquid L1 more quickly.

[0133] When the solvent concentration (average value) of the liquid L1 in the processing tank Tk0 becomes equal to or greater than the concentration reference value, the discharge unit 4 stops discharging the first concentration liquid and discharges the second concentration liquid. That is, the switching valve unit 43 switches from the first state to the second state. Specifically, as shown in the fourth position from the left in FIG. 13, the control unit 6 closes the discharge valve 412 and opens the discharge valve 422. As a result, the liquid L1 in the processing tank Tk0 (i.e., the second concentration liquid) is supplied to the organic solvent recovery unit 5 through the second discharge pipe 421.

[0134] When the pure water on the main surfaces of the substrates W has been sufficiently replaced with the organic solvent, the processing unit 1 dries the plurality of substrates W (step S23: drying step). For example, the solvent vapor supply unit 22 stops the supply of organic solvent vapor, the inert gas supply unit 23 supplies inert gas to the processing chamber H1, and the gas exhaust unit 3 exhausts the gas within the processing chamber H1. Specifically, as shown first from the left in FIG. 14, the control unit 6 closes the supply valve 223, opens the supply valve 233, and activates the aspirator 32. The gas exhaust unit 3 adjusts the pressure within the processing chamber H1 to a first pressure value suitable for drying the substrates W. This allows the processing unit 1 to quickly dry the substrates W.

[0135] When the substrate W is sufficiently dried, the processing unit 1 increases the pressure in the processing chamber H1 (step S24: pressure increasing step). Specifically, as shown second from the left in FIG. 14, the control unit 6 stops the operation of the aspirator 32. The inert gas supply unit 23 continues to supply the inert gas into the processing chamber H1, so that the pressure in the processing chamber H1 increases. For example, the inert gas supply unit 23 supplies the inert gas so that the pressure in the processing chamber H1 reaches a second pressure value.

[0136] Next, the processing unit 1 opens the lid 1b, and causes the substrate holder 10 to lift the plurality of substrates W to a position above the processing chamber H1 (step S25; unloading step: also see the third from the left in FIG. 14).

[0137] In the second example of the second embodiment, the first concentration liquid and the second concentration liquid are sequentially discharged from the processing tank Tk0 while the pure water on the main surface of the substrate W is being replaced with the organic solvent (step S22). Therefore, it is not necessary to discharge the first concentration liquid and the second concentration liquid after the drying process of the substrate W. This allows the next plurality of substrates W to be loaded into the processing unit 1 (processing chamber H1) at an earlier timing. In other words, the processing unit 1 can process the substrates W with a higher throughput.

[0138] In the second example, the first concentration liquid and the second concentration liquid are discharged from the processing tank Tk0 while the substrate W is being raised to the drying position. If the pressure in the processing chamber H1 is low, it is desirable to provide a liquid delivery unit (e.g., a pump or an ejector) in the first discharge pipe 411 and the second discharge pipe 421. This allows the liquid delivery unit to quickly deliver the first concentration liquid and the second concentration liquid even when the pressure in the processing chamber H1 is low. However, providing a liquid delivery unit in the common discharge pipe 400 may cause the first concentration liquid remaining in the liquid delivery unit to mix with the second concentration liquid. Providing separate liquid delivery units in the first branch pipe 401 and the second branch pipe 402 can prevent the first concentration liquid and the second concentration liquid from confluent. However, this may increase manufacturing costs. Below, we aim to quickly discharge the second concentration liquid while reducing the number of liquid delivery units.

[0139] 15 is a diagram schematically illustrating a third example of the substrate processing apparatus 100 according to the second embodiment. The substrate processing apparatus 100 according to the third example differs from the substrate processing apparatus 100 according to the second example in that it includes an exhaust unit 4 and a gas exhaust unit 3. In the third example, an aspirator 32 is inserted into a first branch pipe 401. In this configuration, the common exhaust pipe 400 and the first branch pipe 401 function as a first exhaust pipe 411 and an exhaust pipe 31. The aspirator 32 is, for example, a water-sealed vacuum pump, and also has the function of sending the first concentration liquid through the first exhaust pipe 411. A gas-liquid separator (not shown) may be inserted into the first branch pipe 401 at a position downstream of the aspirator 32. The gas-liquid separator separates the first concentration liquid and the gas and sends them to different exhaust pipes (not shown).

[0140] 15, the second discharge pipe 421 does not necessarily have to be provided with a liquid delivery unit. The organic solvent recovery unit 5 is provided below the bottom of the chamber 1a, and the second concentration solution in the processing tank Tk0 flows through the second discharge pipe 421 by its own weight, as will be described later.

[0141] An example of the operation of the processing unit 1 according to the third example is the same as that shown in FIG. 12. However, the timing of discharging the second concentration liquid differs from that of the second example. FIG. 16 is a diagram showing an example of the change over time in the state of the processing unit 1 after step S22 (solvent replacement process). As shown in the first figure from the left in FIG. 16, the substrate holder 10 raises multiple substrates W to the drying position, while the discharge unit 4 discharges the first concentration liquid from the processing tank Tk0. Here, although the pressure inside the processing chamber H1 is sufficiently lower than standard atmospheric pressure, the control unit 6 activates the aspirator 32 (liquid delivery unit), allowing the first concentration liquid to be discharged more quickly.

[0142] Then, the discharge unit 4 stops discharging the liquid L1 from the processing tank Tk0 while the second concentration liquid is stored in the processing tank Tk0. For example, the discharge unit 4 stops discharging the liquid L1 when the solvent concentration (average value) of the liquid L1 in the processing tank Tk0 becomes equal to or greater than the concentration reference value. Specifically, the control unit 6 closes the tank valve 410.

[0143] Then, when the pure water on the main surfaces of the substrates W has been sufficiently replaced with the organic solvent, the processing unit 1 dries the plurality of substrates W (see the second from the left in FIG. 16). That is, the processing unit 1 dries the plurality of substrates W in a state where substantially only the second concentration liquid is stored in the processing tank Tk0. Specifically, the control unit 6 closes the supply valve 223, opens the supply valve 233, and activates the aspirator 32. The gas exhaust unit 3 adjusts the pressure in the processing chamber H1 to a first pressure value.

[0144] Then, when the substrate W is sufficiently dried, the processing unit 1 increases the pressure in the processing chamber H1 (see the third from the left in FIG. 16). That is, in a state where substantially only the second concentration solution is stored in the processing tank Tk0, the processing unit 1 increases the pressure in the processing chamber H1. Specifically, the control unit 6 stops the aspirator 32. As a result, the pressure in the processing chamber H1 increases over time.

[0145] Then, when the pressure inside the processing chamber H1 has increased to or above a predetermined pressure reference value, the discharge unit 4 discharges the second concentration liquid from the processing tank Tk0 and supplies the second concentration liquid to the organic solvent recovery unit 5 (see the fourth from the left in FIG. 16). Specifically, the control unit 6 opens the tank valve 410 and the discharge valve 422. Because the pressure inside the processing chamber H1 is increased, the discharge unit 4 can quickly discharge the second concentration liquid, for example, by its own weight. Furthermore, because the aspirator 32 into which the first concentration liquid flows is not provided in the second discharge pipe 421, mixing of the second concentration liquid and the first concentration liquid can also be avoided.

[0146] <Third embodiment> 17 is a diagram schematically illustrating an example of a substrate processing apparatus 100 according to the third embodiment. The processing unit 1 according to the third embodiment differs from the first embodiment in the structure of the processing tank Tk0 and the configuration of the discharge unit 4.

[0147] In the third embodiment, the processing tank Tk0 includes a main tank Tk11 and an upflow tank Tk12. The main tank Tk11 stores liquid. Multiple substrates W held by a substrate holder 10 are immersed in the liquid in the main tank Tk11. The upflow tank Tk12 receives liquid that overflows from the top of the main tank Tk11. The upflow tank Tk12 includes a bottom and sidewalls. The bottom has an annular shape in a plan view, and its inner peripheral edge is connected to the sidewall of the main tank Tk11 along its entire circumference. The sidewalls extend upward from the outer peripheral edge of the bottom.

[0148] The discharge unit 4 includes an upflow unit 24. The upflow unit 24 supplies deionized water inside the main tank Tk11, causing the liquid in the main tank Tk11 to overflow from the top. The liquid overflowing from the main tank Tk11 flows into the upflow tank Tk12. The upflow unit 24 includes an upflow pipe 241, a supply pipe 242, and a supply valve 243. The upflow pipe 241 is provided at a position where it is immersed in the liquid in the main tank Tk11, and in the example of FIG. 17, it is provided below the multiple substrates W positioned at the immersion position. In the example of FIG. 17, two upflow pipes 241 are provided. The two upflow pipes 241 are aligned horizontally and are provided on opposite sides of the center of the substrates W in the horizontal direction. The upflow pipe 241 has a discharge port from which deionized water is discharged.

[0149] The supply pipe 242 is a pipe that allows pure water to flow toward the upflow pipe 241. The supply pipe 242 branches into two on the downstream side, and the downstream ends of each of the branches are connected to the upflow pipe 241. The upstream end of the supply pipe 242 is connected to the pure water supply source 214. A supply valve 243 is inserted in the supply pipe 242.

[0150] The upflow unit 24 supplies pure water into the liquid L1 while the liquid L1 is stored in the main tank Tk11. Specifically, the control unit 6 opens the supply valve 243 while the liquid L1 is in the storage state. This causes pure water to be discharged from the upflow pipe 241, causing the liquid L1 in the main tank Tk11 to overflow from the top and be received in the upflow tank Tk12. Initially, the upper portion of the liquid L1, i.e., the high-concentration portion L11, overflows, and the liquid L1 with a relatively high solvent concentration (i.e., the second-concentration liquid) flows into the upflow tank Tk12.

[0151] The upstream end of second discharge pipe 421 is connected to upflow tank Tk12. In the example of Fig. 17, the upstream end of second discharge pipe 421 is connected to the bottom of upflow tank Tk12. When control unit 6 opens discharge valve 422, the second concentrated solution in upflow tank Tk12 is supplied to organic solvent recovery unit 5 through second discharge pipe 421.

[0152] <Example of operation of processing unit 1> An example of the operation of the processing unit 1 according to the third embodiment is the same as that shown in Fig. 2 in the first embodiment. However, the specific operation of step S6 differs from that of the first embodiment. Fig. 18 is a diagram schematically showing an example of the change over time in the state of the processing unit 1 in step S6 (second concentration discharge step) according to the third embodiment.

[0153] In step S6, as shown first from the left in FIG. 18, the upflow unit 24 first supplies pure water into the main tank Tk11. Specifically, the control unit 6 opens the supply valve 243. This causes pure water to be discharged from the upflow pipe 241 into the liquid L1, causing the liquid L1 to overflow from the top of the main tank Tk11. The overflowing liquid L1 is received by the upflow tank Tk12. Initially, the high-concentration portion L11 overflows.

[0154] The discharge unit 4 discharges the second concentrated liquid from the upflow tank Tk12 and supplies the second concentrated liquid to the organic solvent recovery unit 5. Specifically, the control unit 6 opens the discharge valve 422. As a result, the second concentrated liquid from the upflow tank Tk12 is supplied to the organic solvent recovery unit 5 through the second discharge pipe 421.

[0155] When most of the high-concentration portion L11 in the main tank Tk11 flows into the upflow tank Tk12, liquid L1 with a low solvent concentration begins to flow into the upflow tank Tk12. As a result, the average solvent concentration of liquid L1 flowing into the upflow tank Tk12 decreases over time. Therefore, the upflow unit 24 stops supplying pure water when the solvent concentration (average concentration) of liquid L1 flowing into the upflow tank Tk12 reaches a predetermined concentration reference value. Specifically, the control unit 6 closes the supply valve 243. In other words, the upflow unit 24 stores the first-concentration liquid, which has a relatively low solvent concentration, in the main tank Tk11 without allowing it to overflow. This allows the discharge unit 4 to supply the second-concentration liquid, whose concentration is equal to or greater than the concentration reference value, to the organic solvent recovery unit 5.

[0156] For example, the control unit 6 may stop the supply of pure water to the upflow unit 24 when the elapsed time from the start of the supply of pure water reaches or exceeds a predetermined supply reference time. The supply reference time is set in advance to the time required to discharge the second concentration solution.

[0157] When the discharge of the second concentration solution is completed, the discharge unit 4 discharges the first concentration solution from the main tank Tk11 (step S7: first concentration solution discharge step). Specifically, as shown second from the left in Fig. 18, the control unit 6 opens the tank valve 410 and the discharge valve 412. As a result, the first concentration solution in the processing tank Tk0 is discharged to the outside through the first discharge pipe 411.

[0158] As described above, in the third embodiment as well, the discharge unit 4 can supply the second concentrated liquid to the organic solvent recovery unit 5, avoiding at least a portion of the first concentrated liquid stored in the processing tank Tk0 (main tank Tk11). Therefore, similar to the first embodiment, the organic solvent recovery unit 5 can produce the third concentrated liquid in a short time and with low energy.

[0159] Furthermore, in the third embodiment, the substrate processing apparatus 100 causes a second concentration liquid having a relatively high concentration to overflow from the main tank Tk11 and supply it to the organic solvent recovery unit 5 through the upflow tank Tk12 and the second discharge pipe 421. That is, the solvent concentration of the second concentration liquid depends on the amount of liquid L1 overflowing from the main tank Tk11. In other words, the solvent concentration of the second concentration liquid depends on the amount of pure water supplied by the discharge unit 4. The greater the amount of pure water supplied, the lower the solvent concentration of the second concentration liquid. Therefore, the solvent concentration of the second concentration liquid can be easily adjusted by adjusting the amount of pure water supplied by the discharge unit 4.

[0160] Although the substrate processing apparatus 100 has been described in detail above, the above description is merely an example in all respects, and this disclosure is not limited thereto. Furthermore, the various modifications described above can be combined and applied as long as they are not mutually inconsistent. It is understood that many modifications not exemplified can be envisioned without departing from the scope of this disclosure. [Explanation of symbols]

[0161] 10 Board holding part 100 Substrate processing apparatus 1a Chamber 21 Pure water supply section 212 Supply piping 22 Solvent vapor supply section 221 Discharge pipe 241 Upflow Pipe 30 Pressure adjustment unit 4 Discharge section 410 Tank Valve 411 1st discharge piping 421 Discharge piping, 2nd discharge piping 422 Exhaust valve 43 Switching valve section 5. Organic solvent recovery section 6 Control Unit 62 Dehydrator 621 Membrane separator 621c separation membrane Tk0 Treatment Tank Tk11 main tank Tk12 Upflow Tank W substrate

Claims

1. a treatment tank for storing a liquid; a substrate holder that holds a plurality of substrates and immerses the plurality of substrates in the liquid in the processing tank; a discharge unit that discharges a second concentration liquid having a solvent concentration higher than that of the first concentration liquid from the treatment tank, the second concentration liquid being higher than that of the first concentration liquid, while avoiding at least a portion of the first concentration liquid; and an organic solvent recovery unit including a dehydrator that separates water from the second concentrated solution discharged by the discharge unit to generate a third concentrated solution having a solvent concentration higher than that of the second concentrated solution; A substrate processing apparatus comprising:

2. The substrate processing apparatus according to claim 1 , a pure water supply unit including a supply pipe for flowing pure water toward the processing tank; a solvent vapor supply unit including a discharge pipe for discharging vapor of the organic solvent, which has higher volatility than the pure water, into a space above the processing tank; Control unit and Equipped with the substrate holder raises and lowers the plurality of substrates between a submerged position inside the processing tank and a position above the processing tank; The control unit causing the pure water supply unit to supply the pure water to the processing tank, and causing the substrate holder to lower the plurality of substrates to the immersion position, thereby immersing the plurality of substrates in the pure water; While the plurality of substrates are immersed in the pure water, the solvent vapor supply unit discharges the vapor from the discharge pipe to form a liquid film of the organic solvent on the liquid surface of the processing tank; With the liquid film formed, the plurality of substrates are raised from the immersion position; The substrate processing apparatus causes the discharge section to discharge the second concentration solution from the processing tank while the plurality of substrates are in a non-immersed state and positioned above the processing tank.

3. 3. The substrate processing apparatus according to claim 2, a pressure adjusting unit that adjusts the pressure in the processing chamber that accommodates the processing tank; The control unit drying the plurality of substrates while the pressure in the processing chamber is reduced to a first pressure value by the pressure adjusting unit; a substrate processing apparatus, wherein the pressure adjusting unit adjusts the pressure in the processing chamber to be higher than the first pressure value, and the exhaust unit discharges the second concentration solution from the processing tank.

4. 4. The substrate processing apparatus according to claim 1, The substrate processing apparatus, wherein the solvent concentration of the second concentration solution is equal to or greater than a lower limit of an applicable range of solvent concentrations of the dehydrator.

5. 5. The substrate processing apparatus according to claim 4, The dehydrator includes a membrane separator having a separation membrane that allows water contained in the second concentrated solution to pass through.

6. 4. The substrate processing apparatus according to claim 1, The discharge section is a discharge pipe having an upstream end immersed in the liquid in the treatment tank at a height position corresponding to the second concentration liquid, and a downstream end connected to the organic solvent recovery unit; a discharge valve inserted in the discharge pipe; A substrate processing apparatus comprising:

7. The substrate processing apparatus according to claim 1 , The discharge section is a first discharge pipe communicating with the bottom of the treatment tank; a second discharge pipe communicating with the bottom of the treatment tank and connected to the organic solvent recovery unit; a switching valve unit that switches between a first state in which the liquid from the bottom of the processing tank flows through the first discharge pipe and a second state in which the liquid flows through the second discharge pipe; a control unit that causes the switching valve unit to select the first state and discharge the first concentration solution from the bottom of the processing tank, and then causes the switching valve unit to select the second state and discharge the second concentration solution from the bottom of the processing tank; A substrate processing apparatus comprising:

8. 8. The substrate processing apparatus according to claim 7, a chamber containing the processing tank; the discharge unit further includes a tank valve that switches between opening and closing the bottom of the processing tank; an upstream end of the first discharge pipe connected to the bottom of the chamber; a flow rate of the liquid flowing out of the bottom of the treatment tank is greater than a flow rate of the liquid flowing into the upstream end of the first discharge pipe; The control unit causes the switching valve unit to select the second state from the first state, via an interrupted state in which the tank valve is closed.

9. 9. The substrate processing apparatus according to claim 7, a pure water supply unit including a supply pipe for flowing pure water toward the treatment tank and storing the pure water in the treatment tank; a solvent vapor supply unit including a discharge pipe for discharging vapor of the organic solvent, which is more volatile than the pure water, into a space above the processing tank; Equipped with the substrate holder raises and lowers the plurality of substrates between a submerged position inside the processing tank and a position above the processing tank; The control unit causing the pure water supply unit to supply the pure water to the processing tank, and causing the substrate holder to lower the plurality of substrates to the immersion position, thereby immersing the plurality of substrates in the pure water; While the plurality of substrates are immersed in the pure water in the processing tank, the vapor of the organic solvent is discharged from the discharge pipe to form a liquid film of the organic solvent on the liquid surface in the processing tank; a substrate processing apparatus, wherein, while the liquid film is formed, the substrate holding section raises the plurality of substrates, the switching valve section selects the first state, and the liquid in the processing tank is discharged into the first discharge pipe as the first concentration liquid.

10. 4. The substrate processing apparatus according to claim 1, A control unit is provided, The processing tank comprises: a main tank for storing the liquid; an upflow tank that receives the liquid overflowing from the top of the main tank; Including, The discharge section is an upflow pipe provided at a lower portion of the processing tank, for discharging pure water into the processing tank and causing the liquid to overflow from the main tank; a discharge pipe including an upstream end connected to the upflow tank and a downstream end connected to the organic solvent recovery unit; Including, The control unit the pure water is discharged from the upflow pipe, the second concentration liquid among the liquids in the processing tank flows into the upflow tank, and the second concentration liquid is supplied from the upflow tank through the discharge piping to the organic solvent recovery section.

Images