Substrate processing device and substrate processing method

Abstract

The present invention provides a substrate processing device and a substrate processing method that improve the efficiency of substrate processing and that are capable of achieving a reduction in environmental impact by reducing the amount of organic solvent that is discarded. Provided is a substrate processing device for performing substrate processing on a pattern formation surface of a substrate, said substrate processing device comprising: a separation part that collects discharged liquid which is discharged after the substrate processing and which contains an organic solvent and water, and that at least partially removes the water from the collected discharged liquid; a plurality of separation liquid storage parts that independently store a separation liquid which is produced by removal, via the separation part, of at least part of the water from the discharged liquid, for respective differing concentrations of the organic solvent contained in the separation liquid; and a supply part that supplies, to the pattern formation surface of the substrate, a processing liquid which includes at least one of the separation liquids independently stored in each of the plurality of separation liquid storage parts.

Description

Substrate processing apparatus and substrate processing method

[0001] The present invention relates to a substrate processing apparatus and a substrate processing method that are capable of recovering and reusing a processing liquid used in substrate processing.

[0002] In the manufacturing process of semiconductor devices and liquid crystal display devices, substrates such as semiconductor wafers and glass substrates for liquid crystal display devices are treated with a treatment liquid. Specifically, a chemical liquid is supplied to a main surface of the substrate to perform a chemical treatment on the substrate, and then a rinsing process is performed in which water such as deionized water (DIW) is supplied to the main surface of the substrate to which the chemical liquid has been supplied to wash away the chemical liquid on the substrate. Furthermore, after the rinsing process, a drying process is performed to remove water remaining on the substrate and dry the substrate.

[0003] In recent years, with the miniaturization of patterns formed on substrates such as semiconductor substrates, the aspect ratio (the ratio of height to width of the convex portion of the pattern) of the convex portion of the uneven pattern has been increasing. As a result, during a drying process, the surface tension acting on the interface between water that has entered the concave portion of the pattern and the gas in contact with the water attracts adjacent convex portions in the pattern, causing them to collapse, resulting in a problem known as pattern collapse. To address this problem of pattern collapse, for example, a technique has been proposed in which the water on the substrate is replaced with isopropyl alcohol (IPA) to dry the substrate (see, for example, Patent Document 1).

[0004] Japanese Patent Application Publication No. 9-38595

[0005] However, because the compatibility between water and IPA is low, it takes a certain amount of time to replace the water present on the pattern-formed surface of the substrate with IPA. This results in a problem of a long time required for IPA to be ejected onto the pattern-formed surface of the substrate, resulting in poor productivity. Furthermore, if drying is performed in a state where the water has not been completely replaced with IPA, there is a problem of pattern collapse occurring or increasing.

[0006] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a substrate processing apparatus and a substrate processing method that can improve the efficiency of substrate processing and reduce the environmental load by reducing the amount of organic solvent discarded.

[0007] In order to solve the above-mentioned problems, the substrate processing apparatus of the present invention is a substrate processing apparatus that processes a pattern-formed surface of a substrate, and is characterized by comprising: a separation unit that recovers waste liquid containing an organic solvent and water that is discharged after the substrate processing and removes at least a portion of the water from the recovered waste liquid; a plurality of separation liquid storage units that independently store the separation liquids produced by removing at least a portion of the water from the waste liquid by the separation unit, each for a different concentration of the organic solvent contained in the separation liquid; and a supply unit that supplies a processing liquid containing at least any of the separation liquids independently stored in the plurality of separation liquid storage units to the pattern-formed surface of the substrate.

[0008] In the above configuration, it is preferable that the plurality of separation liquid storage sections are provided with a separation liquid circulation path that draws out the stored separation liquid and returns it to each of the separation liquid storage sections, and that a filter that removes impurities contained in the separation liquid is provided midway along the separation liquid circulation path.

[0009] In addition, in the above configuration, it is preferable that the separation unit comprises an effluent storage unit that stores the recovered effluent, a separation membrane unit that separates and removes at least a portion of the water from the effluent discharged from the effluent storage unit, a circulation path that supplies the effluent stored in the effluent storage unit to the separation membrane unit and returns the separated liquid produced in the separation membrane unit to the effluent storage unit, and a water discharge pipe that is connected to the separation membrane unit and discharges the water separated in the separation membrane unit.

[0010] In the above configuration, it is preferable that the supply unit includes a multiple valve that selectively supplies the processing liquid containing at least any of the separation liquids supplied from the plurality of separation liquid storage units to the pattern formation surface.

[0011] Furthermore, in the above configuration, it is preferable that the supply unit further includes an organic solvent supply unit that supplies unused organic solvent and a water supply unit that supplies unused water, and the multiple valve mixes the organic solvent supplied from the organic solvent supply unit and / or the water supplied from the water supply unit with the separation liquid supplied from at least one of the plurality of separation liquid storage units to produce the treatment liquid.

[0012] In order to solve the above-mentioned problems, the substrate processing method of the present invention is a substrate processing method for processing a pattern-formed surface of a substrate, and is characterized by including: a separation process for recovering waste liquid discharged after the substrate processing and containing an organic solvent and water, and removing at least a portion of the water from the recovered waste liquid; a storage process for independently storing separated liquids produced by removing at least a portion of the water from the waste liquid in the separation process, each separated liquid having a different concentration of the organic solvent contained in the separated liquid; and a supply process for supplying a processing liquid containing at least one of the separated liquids independently stored to the pattern-formed surface of the substrate.

[0013] In the above-described configuration, it is preferable that the storing step extracts the stored separated liquid, removes impurities contained in the extracted separated liquid, and then returns the separated liquid for circulation.

[0014] In the above configuration, it is preferable that the separation process includes a process of storing the recovered effluent, a process of separating and removing at least a portion of the water contained in the effluent while circulating the stored effluent, and a process of discharging the water separated from the effluent.

[0015] Furthermore, in the above-mentioned configuration, it is preferable that the supplying step selectively supplies the processing liquid containing at least one of the separating liquids to be supplied onto the pattern formation surface.

[0016] In the above-described configuration, it is preferable that the supplying step mixes unused organic solvent and / or unused water with at least one of the separated liquids stored in the storing step to produce the treated liquid.

[0017] According to the present invention, wastewater generated during substrate processing, containing an organic solvent and water, is recovered, and at least a portion of the water is removed from the recovered wastewater to produce a separated liquid. Furthermore, this separated liquid is incorporated into a processing liquid, and the processing liquid is then used for processing a new substrate. Here, the separated liquids are stored separately according to the organic solvent concentration, and then incorporated into the processing liquid. Therefore, the processing liquid can be reused for processing a new substrate while adjusting the organic solvent concentration. For example, a processing liquid with a low organic solvent concentration has better compatibility with water than a processing liquid with a higher organic solvent concentration. Therefore, when removing water remaining on a pattern-formed surface of a substrate, first supplying a processing liquid with a low organic solvent concentration, followed by sequentially supplying processing liquids with higher organic solvent concentrations, allows the water to be replaced and removed with the processing liquid containing the organic solvent in a shorter time than when a processing liquid containing the organic solvent is supplied from the beginning. As a result, compared to conventional methods, the efficiency of substrate processing is improved, and by reusing the organic solvent contained in the wastewater, organic solvent waste is reduced, thereby reducing environmental impact.

[0018] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments and is not to be limited to the disclosed exemplary embodiments.

[0019] A first embodiment of the present invention will be described below with reference to the drawings. However, parts that are not necessary for the description will be omitted, and some parts will be illustrated enlarged or reduced in size to facilitate the description.

[0020] In this specification, the term "substrate" refers to various substrates such as semiconductor substrates, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, and substrates for magneto-optical disks. Furthermore, in this specification, the term "pattern-formed surface" refers to a surface of a substrate on which a concave-convex pattern is formed in any region, regardless of whether the surface is flat, curved, or concave-convex. Furthermore, in this specification, the substrate is exemplified as one on which a circuit pattern or the like (hereinafter referred to as "pattern") is formed on only one main surface. Here, the pattern-formed surface (main surface) on which the pattern is formed is referred to as the "surface."

[0021] [Substrate Processing Apparatus] <Overall Configuration of Substrate Processing Apparatus> A substrate processing apparatus according to this embodiment will be described below with reference to Fig. 1. Fig. 1 is a plan view showing a schematic configuration of a substrate processing apparatus 100 according to this embodiment. The substrate processing apparatus 100 of this embodiment is a single-wafer type substrate processing apparatus used for various substrate processing such as a rinse process using a rinse liquid and a replacement process with a processing liquid after the rinse process.

[0022] As shown in FIG. 1, the substrate processing apparatus 100 includes a substrate processing section 110 that performs various processes on substrates W, an indexer section 120, and a control section 130 that controls the substrate processing apparatus 100.

[0023] The indexer unit 120 has the function of supplying substrates W to the substrate processing unit 110 or retrieving substrates W from the substrate processing unit 110. Specifically, the indexer unit 120 has four container holders 121, each of which is provided with one container C. Examples of the container C include a FOUP (Front Opening Unified Pod), a SMIF (Standard Mechanical Interface) pod, and an OC (Open Cassette), which accommodate multiple substrates W in a sealed state. Note that, although the present embodiment will be described taking an example in which there are four container holders 121, the present invention is not limited to this. There may be more than one container holder 121.

[0024] The indexer unit 120 further includes a first transport unit 122 for transporting substrates W. The first transport unit 122 is provided between the container holding unit 121 and the substrate processing unit 110. The first transport unit 122 includes a base unit 122a fixed to the apparatus housing, an articulated arm 122b rotatable about a vertical axis relative to the base unit 122a, and a hand 122c attached to the tip of the articulated arm 122b. The hand 122c is structured so that a substrate W can be placed on and held on its upper surface. The first transport unit 122 can access a container C held by the container holding unit 121 to remove an unprocessed substrate W from the container C or store a processed substrate W in the container C.

[0025] The substrate processing section 110 performs a rinse process on the substrate W using a rinse liquid made of water, and a substitution process for substituting the rinse liquid remaining on the surface Wf of the substrate W with a processing liquid containing an organic solvent. The substrate processing section 110 includes a second transport section 111 disposed approximately in the center in a plan view, four substrate processing units 1 disposed to surround the second transport section 111, and a recovery / reuse unit 2 that recovers and reuses waste liquid discharged from the substrate processing units 1. Details of the substrate processing units 1 and the recovery / reuse unit 2 will be described later.

[0026] For example, a substrate transport robot can be used as the second transport part 111. The second transport part 111 randomly accesses each substrate processing unit 1 to transfer the substrate W. The substrate processing part 110 includes a plurality of substrate processing units 1 and a plurality of recovery / recycling units 2, thereby enabling parallel processing of a plurality of substrates W.

[0027] The control unit 130 is electrically connected to each part of the substrate processing apparatus 100 and controls the operation of each part. The control unit 130 is composed of a computer having an arithmetic processing unit and a memory. The arithmetic processing unit uses a CPU that performs various arithmetic processing. The memory also includes a ROM, which is a read-only memory that stores a substrate processing program, a RAM, which is a read / write memory that stores various information, and a magnetic disk that stores control software, data, etc. The magnetic disk pre-stores substrate processing condition information (processing recipe) corresponding to the substrate W, control condition information for controlling the substrate processing apparatus 100, etc. The CPU reads the substrate processing condition information, control condition information, etc. into the RAM and controls each part of the substrate processing apparatus 100 according to the contents thereof.

[0028] <Substrate Processing Unit> Next, the configuration of the substrate processing unit 1 in the substrate processing section 110 will be described below with reference to Fig. 2. Fig. 2 is an explanatory diagram schematically showing the substrate processing unit 1 and the recovery / recycling unit 2 in the substrate processing apparatus of this embodiment. In Fig. 2, XYZ orthogonal coordinate axes are displayed as appropriate to clarify the directional relationships of the illustrated objects. In Fig. 2, the XY plane represents the horizontal plane, and the +Z direction represents the vertical upward direction.

[0029] The substrate processing unit 1 includes at least a chamber 11 which is a container for accommodating a substrate W, a substrate holding part 12 which holds the substrate W, a supply part 13 which supplies a processing liquid to the substrate W held by the substrate holding part 12, and a splash prevention cup 14 which collects rinsing liquid, processing liquid, etc. which are supplied to the substrate W held by the substrate holding part 12 and discharged outside the peripheral edge of the substrate W.

[0030] The substrate holder 12 includes a rotation driver 12a, a spin base 12b, and chuck pins 12c. The spin base 12b has a planar size slightly larger than the substrate W. A plurality of chuck pins 12c for gripping the peripheral edge of the substrate W are provided upright near the peripheral edge of the spin base 12b. The number of chuck pins 12c is not particularly limited, but it is preferable to provide at least three or more in order to securely hold the circular substrate W. In this embodiment, three chuck pins 12c are arranged at equal intervals along the peripheral edge of the spin base 12b. Each chuck pin 12c includes a substrate support pin that supports the peripheral edge of the substrate W from below, and a substrate holding pin that holds the substrate W by pressing against the outer peripheral edge of the substrate W supported by the substrate support pin.

[0031] The spin base 12b is connected to the rotation drive unit 12a. The rotation drive unit 12a rotates around an axis A along the Z direction in response to an operation command from the control unit 130. The rotation drive unit 12a is composed of a known belt, motor, and rotation shaft. When the rotation drive unit 12a rotates around the axis A, the substrate W held by the chuck pins 12c above the spin base 12b rotates together with the spin base 12b around a rotation axis parallel to the vertical direction of the surface Wf of the substrate W, i.e., around the axis A.

[0032] Next, the supply unit 13 will be described. The supply unit 13 is a unit that supplies a processing liquid for replacing DIW or the like remaining on the pattern-formed surface of the substrate W. Examples of the processing liquid include a liquid composed of an organic solvent such as IPA, and a mixed liquid containing an organic solvent and water such as DIW. When the processing liquid is a mixed liquid, the concentration of the organic solvent contained in the mixed liquid is not particularly limited and can be set appropriately.

[0033] As shown in FIG. 2, the supply unit 13 includes at least a nozzle 13a, a multiple valve 13b, a supply pipe 13c, an organic solvent supply unit 13d, and a water supply unit 13e.

[0034] The nozzle 13a is connected to a supply pipe 13c through which the processing liquid is supplied, and can discharge the processing liquid onto the surface Wf of the substrate W. The nozzle 13a is attached to the tip of a horizontally extending arm (not shown). The arm is rotatable under the control of the control unit 130, and the nozzle 13a moves as the arm rotates. When the processing liquid is not being discharged, the nozzle 13a is positioned at a retracted position outside the peripheral edge of the substrate W and outside the splash prevention cup 14. When the processing liquid is being discharged, the arm is rotated in response to an operation command from the control unit 130, and the nozzle 13a is positioned above the spin base 12b, i.e., above the center of the surface Wf of the substrate W (on or near the axis A).

[0035] The multiple valve 13b can selectively supply a processing liquid containing at least one of the separation liquids supplied from the plurality of separation liquid reservoirs onto the front surface Wf of the substrate W (details of the separation liquid reservoirs and the separation liquid will be described later). The multiple valve 13b includes a connection part 131, a valve 132, a first valve 133, a second valve 134, and a third valve 135.

[0036] The valve 132 is provided midway along the path of the supply pipe 13c, which is connected to the downstream side of the connection part 131. The valve 132 is electrically connected to the control part 130 and is normally closed. The opening and closing of the valve 132 is controlled by an operation command from the control part 130. When the valve 132 is opened by an operation command from the control part 130, the processing liquid is supplied from the nozzle 13a through the supply pipe 13c onto the front surface Wf of the substrate W.

[0037] The first valve 133 is provided midway along the first separated liquid supply pipe 32e, which is connected to the upstream side of the connection part 131. The second valve 134 is provided midway along the second separated liquid supply pipe 33e, which is connected to the upstream side of the connection part 131. The third valve 135 is provided midway along the third separated liquid supply pipe 34e, which is connected to the upstream side of the connection part 131. The first valve 133, the second valve 134, and the third valve 135 are each electrically connected to the control part 130 and are normally closed. The opening and closing of these valves is independently controlled by operation commands from the control part 130. The first separated liquid supply pipe 32e, the second separated liquid supply pipe 33e, and the third separated liquid supply pipe 34e will be described in detail below.

[0038] The organic solvent supply unit 13d can supply unused organic solvent to the multiple valve 13b. The organic solvent supply unit 13d includes a supply pipe 136 and an organic solvent reservoir 138. The organic solvent reservoir 138 is connected to the upstream side of the supply pipe 136, and the connection unit 131 is connected to the downstream side. A pump 144, a flow rate control valve 145, and a valve 137 are sequentially provided along the supply pipe 136 from upstream to downstream. The organic solvent reservoir 138 stores unused organic solvent. The pump 144 is controlled by an operation command from the control unit 130, and can send unused organic solvent stored in the organic solvent reservoir 138 to the connection unit 131. The flow rate control valve 145 can adjust the flow rate of unused organic solvent supplied from the organic solvent reservoir 138 by operating the pump 144. The valve 137 is electrically connected to the control unit 130 and is normally closed. The opening and closing of the valve 137 is controlled by an operational command from the control unit 130. When the valve 137 is opened by the operational command from the control unit 130, an unused organic solvent is supplied to the connection unit 131 through the supply pipe 136. The unused organic solvent is not particularly limited, and examples thereof include IPA.

[0039] The water supply unit 13e can supply unused water to the multiple valve 13b. The water supply unit 13e includes a supply pipe 139 and a water storage unit 141. The water storage unit 141 is connected to the upstream side of the supply pipe 139, and the connection unit 131 is connected to the downstream side. A pump 146, a flow rate control valve 147, and a valve 140 are sequentially provided along the supply pipe 139 from upstream to downstream. The water storage unit 141 stores unused water. The pump 146 is controlled by an operational command from the control unit 130, and can send unused water stored in the water storage unit 141 to the connection unit 131. The flow rate control valve 147 can adjust the flow rate of unused water supplied from the water storage unit 141 by operating the pump 146. The valve 140 is electrically connected to the control unit 130 and is normally closed. The opening and closing of the valve 140 is controlled by an operational command from the control unit 130. When the valve 140 is opened in response to an operation command from the control unit 130, unused organic solvent is supplied to the connection unit 131 through the supply pipe 139. The unused water is not particularly limited, and examples thereof include DIW.

[0040] The splash prevention cup 14 is provided to surround the spin base 12b. The splash prevention cup 14 is connected to a lifting drive mechanism (not shown) and can be raised and lowered in the Z direction shown in Fig. 2. When a rinse liquid or a processing liquid is supplied to the front surface Wf of the substrate W, the splash prevention cup 14 is positioned at a predetermined position as shown in Fig. 2 by the lifting drive mechanism and surrounds the substrate W held by the chuck pins 12c from a lateral position. This makes it possible to collect liquids such as rinse liquid and processing liquid that splash from the substrate W or the spin base 12b.

[0041] <Recovery / Recycling Unit> Next, the configuration of the recovery / recycling unit 2 in the substrate processing section 110 will be described below with reference to FIG.

[0042] The recovery / reuse unit 2 recovers the processing liquid used to remove water remaining on the surface Wf of the substrate W, and separates and removes the water from the recovered processing liquid to make it reusable. Specifically, as shown in FIG. 2 , the recovery / reuse unit 2 includes at least a separation section 20 and a separated liquid storage section 30.

[0043] The separation unit 20 can recover waste liquid consisting of the processing liquid used in substrate processing and remove at least a portion of the water from the recovered waste liquid. The substrate processing here refers to a process of supplying a processing liquid to the front surface Wf of the substrate W and replacing water remaining on the front surface Wf of the substrate W with the processing liquid. The separation unit 20 includes at least a recovery pipe 21, an intermediate waste liquid storage unit 22, a waste liquid discharge pipe 23, a waste liquid storage unit 24, a separation membrane unit 25, a circulation path 26, a separation liquid discharge pipe 27, and a water discharge pipe 28.

[0044] The recovery pipe 21 supplies the waste liquid discharged from the splash prevention cup 14 to the intermediate waste liquid storage section 22. One end of the recovery pipe 21 is connected to the splash prevention cup 14, and the other end is connected to the intermediate waste liquid storage section 22. A valve 21a is provided midway along the recovery pipe 21. The valve 21a is electrically connected to the control section 130 and is normally closed. The opening and closing of the valve 21a is controlled by an operation command from the control section 130. When the valve 21a is opened by an operation command from the control section 130, the waste liquid collected in the splash prevention cup 14 passes through the recovery pipe 21 and is supplied to the intermediate waste liquid storage section 22.

[0045] The intermediate effluent storage section 22 is connected to the effluent storage section 24 via the effluent discharge pipe 23. The intermediate effluent storage section 22 can temporarily store the collected effluent. A pump 23b and a valve 23a are sequentially provided along the effluent discharge pipe 23 from upstream to downstream. The pump 23b is controlled by an operation command from the control section 130, and can send the effluent stored in the intermediate effluent storage section 22 to the effluent storage section 24. The valve 23a is electrically connected to the control section 130 and is normally closed. The opening and closing of the valve 23a is controlled by an operation command from the control section 130.

[0046] The effluent storage section 24 can store the effluent supplied from the intermediate effluent storage section 22 via the effluent discharge pipe 23. A circulation path 26 is connected to the effluent storage section 24. A separation membrane section 25 is provided midway along the path of this circulation path 26. This allows the effluent stored in the effluent storage section 24 to be discharged and supplied to the separation membrane section 25, and then the separated liquid obtained by separating at least a portion of the water contained in the effluent by the separation membrane section 25 can be returned to the effluent storage section 24.

[0047] The effluent storage section 24 is provided with an effluent temperature adjustment section 24a. The effluent temperature adjustment section 24a can adjust the temperature of the effluent stored in the effluent storage section 24. The effluent temperature adjustment section 24a is electrically connected to the control section 130 and adjusts the temperature of the effluent stored in the effluent temperature adjustment section 24a in response to an operational command from the control section 130. This can improve the separation performance of the zeolite membrane, for example, when a zeolite membrane is used as the separation membrane in the separation membrane section 25 described below. In this case, the temperature of the effluent stored in the effluent storage section 24 is preferably within the range of 25°C (RT) to 80°C, more preferably within the range of 50°C to 80°C, and even more preferably within the range of 70°C to 80°C, for example, when separating the IPA and water in the waste liquid without vaporizing them. The effluent temperature adjustment section 24a is not particularly limited, and known temperature adjustment mechanisms such as a Peltier element or piping through which temperature-adjusted water is passed can be used.

[0048] The separation membrane unit 25 can separate and remove at least a portion of the water contained in the effluent stored in the effluent storage unit 24. Examples of separation membranes used in the separation membrane unit 25 include dehydration membranes that allow water to pass through but do not allow organic solvents such as IPA to pass through. The separation membrane may be a polymer membrane made of a polymer material, an inorganic membrane made of an inorganic material, or other membranes. Specific examples of separation membranes include, as described above, zeolite membranes made of zeolite.

[0049] As described above, the circulation path 26 is provided with the separation membrane unit 25, which allows the separated liquid obtained by separating at least a portion of the water contained in the effluent to be returned to the effluent storage unit 24. Furthermore, a pump 26a is provided midway along the circulation path 26, downstream of the effluent storage unit 24 and upstream of the separation membrane unit 25. The pump 26a is controlled by an operation command from the control unit 130, and can circulate the effluent stored in the effluent storage unit 24 through the circulation path 26. Furthermore, a concentration meter 26b is provided downstream of the separation membrane unit 25 for measuring the concentration of an organic solvent such as IPA in the separation liquid. The value of the concentration of the organic solvent in the separation liquid measured by the concentration meter 26b is input to the control unit 130.

[0050] One end of the separated liquid discharge pipe 27 is connected to the discharged liquid reservoir 24, and the other end is connected to the separated liquid reservoir 30. A filter 27a is provided midway along the separated liquid discharge pipe 27. The filter 27a can remove impurities such as solids, such as particles, and metal ions contained in the separated liquid. When removing metal ions, for example, an ion exchange resin can be used as the filter 27a.

[0051] The water discharge pipe 28 is connected to the separation membrane unit 25 and discharges the water separated from the waste liquid (or separated liquid) in the separation membrane unit 25 .

[0052] The separated liquid storage section 30 can store the separated liquid produced in the separation section 20 independently for each concentration of the organic solvent contained in the separated liquid. In this embodiment, the separated liquid storage section 30 includes at least a concentration meter 31, a first separated liquid storage section 32, a second separated liquid storage section 33, and a third separated liquid storage section 34. The first separated liquid storage section 32 stores a separated liquid having the lowest concentration of organic solvent (for example, a concentration of organic solvent of 25% by mass relative to the total mass of the separated liquid; hereinafter referred to as the "first separated liquid"), the third separated liquid storage section 34 stores a separated liquid having the highest concentration of organic solvent (for example, a concentration of organic solvent of 75% by mass relative to the total mass of the separated liquid; hereinafter referred to as the "third separated liquid"), and the second separated liquid storage section 33 stores a separated liquid having an organic solvent concentration greater than that of the first separated liquid but less than that of the third separated liquid (for example, a concentration of organic solvent of 50% by mass relative to the total mass of the separated liquid; hereinafter referred to as the "second separated liquid").

[0053] The concentration meter 31 can measure the concentration of an organic solvent such as IPA in the separation liquid supplied from the waste liquid reservoir 24. The measured value of the concentration of the organic solvent in the separation liquid measured by the concentration meter 31 is input to the control unit 130.

[0054] The first separated liquid reservoir 32 includes at least a first supply pipe 32a, a first valve 32b, a first separated liquid reservoir tank 32c, a first separated liquid circulation path 32d, and a first separated liquid supply pipe 32e.

[0055] The first supply pipe 32a branches off from the separated liquid discharge pipe 27 downstream of the concentration meter 31 and is connected to a first separated liquid storage tank 32c. A first valve 32b is provided midway along the first supply pipe 32a. The first valve 32b is electrically connected to the control unit 130. The opening and closing of the first valve 32b is controlled by an operation command from the control unit 130 based on the measured value of the organic solvent concentration measured by the concentration meter 31.

[0056] A first separated liquid circulation path 32d is connected to the first separated liquid storage tank 32c for circulating the first separated liquid stored in the first separated liquid storage tank 32c. Furthermore, a first pump 32f and a first filter 32g are sequentially provided along the first separated liquid circulation path 32d from upstream to downstream. The first pump 32f is controlled by an operation command from the control unit 130 to circulate the first separated liquid stored in the first separated liquid storage tank 32c through the first separated liquid circulation path 32d. The first filter 32g has the function of removing solids such as particles and impurities such as metal ions contained in the first separated liquid. To remove metal ions, for example, an ion exchange resin can be used as the first filter 32g.

[0057] The first separated liquid supply pipe 32e is connected to the first separated liquid storage tank 32c and the connection part 131 of the multiple valve 13b. This allows the first separated liquid stored in the first separated liquid storage tank 32c to be supplied to the connection part 131 of the multiple valve 13b. A pump 142 and a flow rate adjustment valve 143 are provided along the first separated liquid supply pipe 32e from the upstream side to the downstream side. The pump 142 is controlled by an operation command from the control unit 130, and can send the first separated liquid stored in the first separated liquid storage tank 32c to the connection part 131. The flow rate adjustment valve 143 can adjust the flow rate of the first separated liquid supplied from the first separated liquid storage tank 32c.

[0058] The second separated liquid reservoir 33 includes at least a second supply pipe 33a, a second valve 33b, a second separated liquid reservoir tank 33c, a second separated liquid circulation path 33d, and a second separated liquid supply pipe 33e.

[0059] The second supply pipe 33a branches off downstream of the branch point where the first supply pipe 32a branches off from the separated liquid discharge pipe 27, and is connected to a second separated liquid storage tank 33c. A second valve 33b is provided midway along the second supply pipe 33a. The second valve 33b is electrically connected to the control unit 130. The opening and closing of the second valve 33b is controlled by an operation command from the control unit 130 based on the measured value of the organic solvent concentration measured by the concentration meter 31.

[0060] A second separated liquid circulation path 33d is connected to the second separated liquid storage tank 33c for circulating the second separated liquid stored in the second separated liquid storage tank 33c. Furthermore, a second pump 33f and a second filter 33g are sequentially provided along the second separated liquid circulation path 33d from upstream to downstream. The second pump 33f is controlled by an operation command from the control unit 130 to circulate the second separated liquid stored in the second separated liquid storage tank 33c through the second separated liquid circulation path 33d. The second filter 33g has the function of removing solids such as particles and impurities such as metal ions contained in the second separated liquid. To remove metal ions, for example, an ion exchange resin can be used as the second filter 33g.

[0061] The second separated liquid supply pipe 33e is connected to the second separated liquid storage tank 33c and the connection part 131 of the multiple valve 13b. This allows the second separated liquid stored in the second separated liquid storage tank 33c to be supplied to the connection part 131 of the multiple valve 13b. A pump 142 and a flow rate adjustment valve 143 are provided in the second separated liquid supply pipe 33e from the upstream side to the downstream side. By operating the pump 142, the second separated liquid stored in the second separated liquid storage tank 33c can be supplied to the connection part 131. The flow rate adjustment valve 143 can adjust the flow rate of the second separated liquid supplied from the second separated liquid storage tank 33c.

[0062] The third separated liquid reservoir 34 includes at least a third supply pipe 34a, a third valve 34b, a third separated liquid storage tank 34c, a third separated liquid circulation path 34d, and a third separated liquid supply pipe 34e.

[0063] The third supply pipe 34a is connected downstream of the branch point where the second supply pipe 33a branches off from the separated liquid discharge pipe 27, and is connected to a third separated liquid storage tank 34c. A third valve 34b is provided midway along the third supply pipe 34a. The third valve 34b is electrically connected to the control unit 130. The opening and closing of the third valve 34b is controlled by an operation command from the control unit 130 based on the measured value of the organic solvent concentration measured by the concentration meter 31.

[0064] A third separated liquid circulation path 34d is connected to the third separated liquid storage tank 34c for circulating the third separated liquid stored in the third separated liquid storage tank 34c. Furthermore, a third pump 34f and a third filter 34g are sequentially provided along the third separated liquid circulation path 34d from upstream to downstream. The third pump 34f is controlled by an operation command from the control unit 130 to circulate the third separated liquid stored in the third separated liquid storage tank 34c through the third separated liquid circulation path 34d. The third filter 34g has the function of removing solids such as particles and impurities such as metal ions contained in the third separated liquid. To remove metal ions, for example, an ion exchange resin can be used as the third filter 34g.

[0065] The third separated liquid supply pipe 34e is connected to the third separated liquid storage tank 34c and the connection part 131 of the multiple valve 13b. This allows the third separated liquid stored in the third separated liquid storage tank 34c to be supplied to the connection part 131 of the multiple valve 13b. A pump 142 and a flow rate adjustment valve 143 are provided in the third separated liquid supply pipe 34e from the upstream side to the downstream side. By operating the pump 142, the third separated liquid stored in the third separated liquid storage tank 34c can be supplied to the connection part 131. The flow rate adjustment valve 143 can adjust the flow rate of the third separated liquid supplied from the third separated liquid storage tank 34c.

[0066] [Substrate Processing Method] Next, a substrate processing method using the substrate processing apparatus 100 of this embodiment will be described below. The substrate processing method of this embodiment recovers a processing liquid containing an organic solvent used to remove a rinse liquid composed of water, such as DIW, remaining on the surface Wf of the substrate W, and separates and removes the water from the recovered processing liquid for reuse. This reduces the amount of organic solvent waste and reduces the environmental impact. More specifically, the substrate processing method of this embodiment includes, in the recovery and reuse of processing liquid after substrate processing, a draining process for draining the processing liquid after substrate processing; a separating process for recovering the drained liquid and removing at least a portion of the water from the drained liquid; a storing process for independently storing separation liquids, each containing a different concentration of organic solvent contained in the separation liquid, from the drained liquid from which at least a portion of the water has been removed in the separating process; and a supplying process for supplying processing liquids containing at least one of the separation liquids independently stored in the storing process to the surface Wf of the substrate W.

[0067] The liquid draining step is a step of draining the processing liquid used in substrate processing on the front surface Wf of the substrate W from the substrate processing unit 1. When the valve 21 a is opened in response to an operation command from the control unit 130, the processing liquid collected in the splash prevention cup 14 is discharged as waste liquid through the recovery pipe 21 connected to the splash prevention cup 14. The waste liquid discharged through the recovery pipe 21 is stored in the intermediate waste liquid storage section 22.

[0068] The separation process is a process of producing a separated liquid by separating and removing at least a portion of the water from the effluent collected and stored in the intermediate effluent storage section 22. When the valve 23a is opened in response to an operation command from the control section 130, the pump 23b is operated to supply the effluent stored in the intermediate effluent storage section 22 to the effluent storage section 24 through the effluent discharge pipe 23. When a predetermined amount of effluent has been stored in the effluent storage section 24, the control section 130 issues an operation command to the valve 23a to close the valve 23a.

[0069] The effluent stored in the effluent storage unit 24 is heated to a predetermined temperature by the effluent temperature adjustment unit 24a in response to an operational command from the control unit 130. Furthermore, the effluent stored in the effluent storage unit 24 is discharged by the operation of the pump 26a and circulated through the circulation path 26. The effluent flowing through the circulation path 26 has at least a portion of the water contained in the effluent separated and removed by the separation membrane unit 25 provided midway along the circulation path 26. Because the effluent is heated by the effluent temperature adjustment unit 24a, for example, when a zeolite membrane is used in the separation membrane unit 25, separation performance can be improved. The effluent from which at least a portion of the water has been removed by the separation membrane unit 25 is discharged as a separated liquid. Furthermore, the water separated by the separation membrane unit 25 is discharged through the water discharge pipe 28. The concentration of the organic solvent contained in the separated liquid discharged from the separation membrane unit 25 is measured by the concentration meter 26b. The measured value of the organic solvent concentration is input to the control unit 130, and if it is determined that the measured value has not reached the predetermined value, the circulation of the separated liquid in the circulation path 26 is continued until the measured value of the organic solvent concentration by the concentration meter 26b reaches the predetermined value. As a result, the separated liquid whose organic solvent concentration has reached the predetermined value is stored in the waste liquid storage unit 24. Furthermore, if it is determined that the measured value of the organic solvent concentration in the separated liquid by the concentration meter 26b has reached the predetermined value, the separated liquid is discharged from the separated liquid discharge pipe 27.

[0070] Here, a filter 27a is provided midway along the separated liquid discharge pipe 27 for discharging the separated liquid from the waste liquid reservoir 24. Therefore, in this step, the filter 27a can further separate and remove impurities such as particles and metal ions from the separated liquid whose organic solvent concentration has reached a predetermined value. During the separation step, the first valve 32b of the first separated liquid reservoir 32, the second valve 33b of the second separated liquid reservoir 33, and the third valve 34b of the third separated liquid reservoir 34 are preferably closed by an operation command from the control unit 130.

[0071] The storage step is a step of independently storing the separated liquid produced in the separation step, each with a different organic solvent concentration. This step is performed after the separated liquid, whose organic solvent concentration has reached a predetermined value, is stored in the waste liquid storage unit 24. In this step, the concentration meter 31 first measures the organic solvent concentration of the separated liquid flowing through the separated liquid discharge pipe 27. The measured organic solvent concentration is then input to the control unit 130. Based on the input organic solvent concentration measurement, the control unit 130 issues an operational command to open one of the first valve 32b, the second valve 33b, and the third valve 34b and close the other valves. For example, in the case of a separated liquid with the lowest organic solvent concentration, the control unit 130 issues an operational command to open the first valve 32b and close the second valve 33b and the third valve 34b. As a result, the separated liquid having a low concentration of organic solvent is supplied as the first separated liquid to the first separated liquid storage tank 32c via the first supply pipe 32a and stored in the first separated liquid storage tank 32c. In this manner, in this step, the separated liquids having different organic solvent concentrations can be stored in either the first separated liquid storage tank 32c, the second separated liquid storage tank 33c, or the third separated liquid storage tank 34c.

[0072] Furthermore, in the storage step, the first separated liquid stored in the first separated liquid storage tank 32c is circulated through the first separated liquid circulation path 32d, while impurities in the first separated liquid are separated and removed by the first filter 32g. The circulation of the first separated liquid through the first separated liquid circulation path 32d is performed by operating the first pump 32f. In this step, impurities are also removed from the second separated liquid and the third separated liquid stored in the second separated liquid storage tank 33c and the third separated liquid storage tank 34c, respectively, using the second filter 33g and the third filter 34g in the second separated liquid circulation path 33d and the third separated liquid circulation path 34d, respectively.

[0073] The supplying step is a step of generating a processing liquid containing at least one of the first to third separation liquids, which are stored independently in the storing step, and supplying the processing liquid to the front surface Wf of the substrate W. In this step, the processing liquid is supplied onto the front surface Wf of the substrate W to replace the water used as a rinse liquid and to remove water remaining on the front surface Wf of the substrate W.

[0074] Here, the largest amount of water remains on the surface Wf of the substrate W immediately after substrate processing. Therefore, even if a processing liquid consisting only of an organic solvent is supplied onto the surface Wf of the substrate W to replace and remove the water, it takes a certain amount of time to replace the water with the organic solvent because organic solvents are inherently liquids with low compatibility with water. However, by replacing the water with a processing liquid having a low organic solvent concentration and then supplying processing liquids having higher organic solvent concentrations in stages, the water can be replaced and removed with the organic solvent processing liquid in a shorter time than if the processing liquid was supplied from the beginning. Therefore, in this process, the control unit 130 first opens the first valve 133 and closes the second valve 134 and the third valve 135 in response to an operation command, and then supplies the first separated liquid, which has the lowest organic solvent concentration, from the first separated liquid storage tank 32c to the connection unit 131 via the first separated liquid supply pipe 32e. Furthermore, the valve 132 is opened in response to an operation command from the control unit 130, whereby the treatment liquid made of the first separation liquid is supplied onto the front surface Wf of the substrate W through the supply pipe 13c and the nozzle 31a. This allows the water remaining on the front surface Wf of the substrate W to be replaced with the treatment liquid having the lowest concentration of organic solvent.

[0075] Next, in order to replace the processing liquid consisting of the first separation liquid remaining on the surface Wf of the substrate W with a processing liquid consisting of a second separation liquid having a higher organic solvent concentration than the first separation liquid, the control unit 130 issues an operation command to open the second valve 134 and the valve 132 and close the first valve 133 and the third valve 135. Next, in order to replace the processing liquid consisting of the second separation liquid remaining on the surface Wf of the substrate W with a processing liquid consisting of a third separation liquid having a higher organic solvent concentration than the second separation liquid, the control unit 130 issues an operation command to open the third valve 135 and the valve 132 and close the first valve 133 and the second valve 134. Finally, in order to replace the processing liquid consisting of the third separation liquid remaining on the surface Wf of the substrate W with a processing liquid consisting of only an organic solvent, the control unit 130 issues an operation command to open the valve 137 and close the first valve 133, the second valve 134, and the third valve 135. In this way, the control unit 130 supplies a treatment liquid with a gradually increasing concentration of organic solvent, and finally supplies a treatment liquid consisting only of organic solvent, thereby replacing and removing the water remaining on the surface Wf of the substrate W with the treatment liquid in a shorter time than conventional methods.

[0076] The concentration of the organic solvent contained in the processing liquid supplied to the substrate W may be adjusted by appropriately mixing the first to third separating liquids supplied from the separating liquid reservoir 30, the unused organic solvent supplied from the organic solvent supply unit 13d, and the unused water supplied from the water supply unit 13e. In this case, the control unit 130 issues operational commands to the first valve 133, the second valve 134, and the third valve 135 to independently open and close the valves while adjusting the flow rate with the flow rate adjustment valve 143. The control unit 130 also issues operational commands to the organic solvent supply unit 13d to open and close the valve 137 while adjusting the flow rate with the flow rate adjustment valve 145, and also issues operational commands to the water supply unit 13e to open and close the valve 140 while adjusting the flow rate with the flow rate adjustment valve 147.

[0077] Second Embodiment A second embodiment of the present invention will be described below.

[0078] [Substrate Processing Apparatus] <Overall Configuration of Substrate Processing Apparatus and Substrate Processing Units> The substrate processing apparatus according to the second embodiment has basically the same configuration as the substrate processing apparatus 100 according to the first embodiment (see FIG. 1 ), except for the recovery and reuse unit of the substrate processing section 110. Therefore, detailed descriptions of the indexer section 120, the control section 130, and the substrate processing units 1 of the substrate processing section 110 will be omitted and the same reference numerals will be used.

[0079] <Recovery / Recycling Unit> Next, the configuration of the recovery / recycling unit in the substrate processing section 110 will be described below with reference to Fig. 3. Fig. 3 is an explanatory diagram schematically showing the substrate processing unit 1 and recovery / recycling unit 2' in the substrate processing apparatus of this embodiment. In Fig. 3, XYZ orthogonal coordinate axes are displayed as appropriate to clarify the directional relationships of the illustrated objects. In Fig. 3, the XY plane represents the horizontal plane, and the +Z direction represents the vertical upward direction.

[0080] 3, the recovery and reuse unit 2′ of this embodiment differs from the recovery and reuse unit 2 of the first embodiment mainly in that the intermediate effluent storage section 22 is omitted from the separation section 20′. Another difference is that in the separation section 20′, a separated liquid discharge pipe 27′ for supplying the separated liquid to the separated liquid storage section 30 is branched off from the circulation path 26. More specifically, the separation section 20′ at least includes a recovery pipe 21, a discharged liquid storage section 24, a separation membrane section 25, a circulation path 26, a separated liquid discharge pipe 27′, and a water discharge pipe 28.

[0081] The recovery pipe 21 directly supplies the waste liquid discharged from the splash prevention cup 14 to the waste liquid storage section 24. One end of the recovery pipe 21 is connected to the splash prevention cup 14, and the other end is connected to the waste liquid storage section 24. A concentration meter 21b and a valve 21a are sequentially provided along the recovery pipe 21 from upstream to downstream. The valve 21a is electrically connected to the control section 130 and is normally closed. The opening and closing of the valve 21a is controlled by an operational command from the control section 130. The concentration meter 21b measures the concentration of the organic solvent in the waste liquid discharged from the splash prevention cup 14. The measured value of the concentration of the organic solvent in the waste liquid measured by the concentration meter 21b is input to the control section 130. The control section 130 issues an operational command to the valve 21a to open or close it based on the input measured value of the concentration of the organic solvent in the waste liquid.

[0082] A pump 26a, a separation membrane unit 25, and a concentration meter 26b are sequentially provided in the circulation path 26 from the upstream side to the downstream side. A three-way valve 41 is provided at the branch point where the separated liquid discharge pipe 27' branches off from the circulation path 26. By providing the three-way valve 41 at the branch point, the flow path of the separated liquid flowing through the circulation path 26 can be changed to the separated liquid discharge pipe 27'. The three-way valve 41 is electrically connected to the control unit 130, and the change of flow path by the three-way valve 41 is controlled by an operation command from the control unit 130.

[0083] The separated liquid discharge pipe 27' branches off from the circulation path 26 and is connected to the separated liquid storage section 30. A filter 27a is provided in the separated liquid discharge pipe 27' upstream of the branch point where the separated liquid discharge pipe 27' branches off to the first supply pipe 32a of the first separated liquid storage section 32. The filter 27a can remove impurities such as solids such as particles and metal ions contained in the separated liquid. When removing metal ions, for example, an ion exchange resin can be used as the filter 27a.

[0084] [Substrate Processing Method] Next, a substrate processing method using the substrate processing apparatus 100 of this embodiment will be described below. As in the first embodiment, the substrate processing method of this embodiment includes a draining process of draining the processing liquid after substrate processing, a separation process of recovering the drained liquid and removing at least a portion of the water from the drained liquid, a storing process of independently storing the separated liquids produced in the separation process according to the different concentrations of organic solvent contained in the separated liquid, and a supplying process of supplying a processing liquid containing at least one of the separated liquids independently stored in the storing process to the front surface Wf of the substrate W. Note that in this embodiment, the supplying process is the same as in the first embodiment, and therefore will not be described below.

[0085] In the draining step, when the processing liquid collected in the splash prevention cup 14 is discharged as waste liquid through the recovery pipe 21, the concentration of the organic solvent in the waste liquid is measured by a concentration meter 21b provided midway through the recovery pipe 21. Furthermore, the measured value of the organic solvent concentration is input to the control unit 130, and when the measured value is determined to be a predetermined value, the control unit 130 issues an operational command to the valve 21a to open. As a result, the waste liquid having the predetermined organic solvent concentration is supplied to the waste liquid storage unit 24. When a predetermined amount of waste liquid has been stored in the waste liquid storage unit 24, the control unit 130 issues an operational command to the valve 21a to close it.

[0086] Subsequently, in the separation process, at least a portion of the water contained in the effluent stored in the effluent storage section 24 is removed. That is, the pump 26a is operated to circulate the effluent stored in the effluent storage section 24 through the circulation path 26. The effluent flowing through the circulation path 26 has at least a portion of the water separated and removed in the separation membrane section 25 provided midway through the circulation path 26. The effluent from which at least a portion of the water has been removed is discharged from the separation membrane section 25 as a separated liquid. The water separated by the separation membrane section 25 is discharged from the water discharge pipe 28. Furthermore, the concentration meter 26b measures the concentration of the organic solvent contained in the separated liquid discharged from the separation membrane section 25. The measured value of the organic solvent concentration is input to the control section 130, and if it is determined that the measured value has reached a predetermined value, the control section 130 issues an operational command to the three-way valve 41 to change the flow path to the separated liquid discharge pipe 27'. As a result, the separated liquid is sent to the separated liquid storage unit 30 via the separated liquid discharge pipe 27'. On the other hand, if it is determined that the measured value of the organic solvent concentration has not reached the predetermined value, no operational command to change the flow path is sent to the three-way valve 41, and the separated liquid is returned to the waste liquid storage unit 24 via the circulation path 26. Circulation of the separated liquid through the circulation path 26 continues until the measured value of the organic solvent concentration by the concentration meter 26b reaches the predetermined value. As a result, the separated liquid whose organic solvent concentration has reached the predetermined value is stored in the waste liquid storage unit 24. Note that a filter 27a is provided midway along the separated liquid discharge pipe 27, so that impurities such as particles are removed from the separated liquid flowing through the separated liquid discharge pipe 27. Furthermore, during the separation process, the first valve 32b of the first separated liquid storage unit 32, the second valve 33b of the second separated liquid storage unit 33, and the third valve 34b of the third separated liquid storage unit 34 are preferably closed by operational commands from the control unit 130.

[0087] In the storage step, the control unit 130 issues an operational command to open one of the first valve 32b, the second valve 33b, and the third valve 34b and close the other valves based on the measured value of the organic solvent concentration in the separated liquid measured by the concentration meter 26b of the separation unit 20′. For example, in the case of a separated liquid having the lowest organic solvent concentration, the control unit 130 issues an operational command to open the first valve 32b and close the second valve 33b and the third valve 34b. As a result, the separated liquid having the lowest organic solvent concentration is stored in the first separated liquid storage tank 32c via the first supply pipe 32a. In this way, in this step, the separated liquid having different organic solvent concentrations can be stored in one of the first separated liquid storage tank 32c, the second separated liquid storage tank 33c, or the third separated liquid storage tank 34c. In the storage step, the first to third separated liquids stored independently in either the first separated liquid storage section, the second separated liquid storage section, or the third separated liquid storage section are reused as treatment liquids in the supply step, in the same manner as in the first embodiment.

[0088] Third Embodiment A third embodiment of the present invention will be described below.

[0089] [Substrate Processing Apparatus] <Overall Configuration of Substrate Processing Apparatus and Substrate Processing Units> The substrate processing apparatus according to the third embodiment has basically the same configuration as the substrate processing apparatus 100 according to the first and second embodiments (see FIG. 1 ), except for the recovery and reuse unit of the substrate processing section 110. Therefore, detailed descriptions of the indexer section 120, the control section 130, and the substrate processing units 1 of the substrate processing section 110 will be omitted and the same reference numerals will be used.

[0090] <Recovery / Recycling Unit> Next, the configuration of the recovery / recycling unit in the substrate processing section 110 will be described below with reference to FIG. 4. FIG. 4 is an explanatory diagram schematically showing the substrate processing unit 1 and the recovery / recycling unit 2″ in the substrate processing apparatus of this embodiment. In FIG. 4, XYZ orthogonal coordinate axes are appropriately displayed to clarify the directional relationship of the objects shown. In the figure, the XY plane represents the horizontal plane, and the +Z direction represents the vertical upward direction.

[0091] As shown in FIG. 4 , the recovery and reuse unit 2″ of this embodiment differs from the recovery and reuse unit 2′ of the second embodiment mainly in that a separation section 20″ including two first and second separation membrane sections 25a and 25b is used, enabling the flow path of the waste liquid (or separated liquid) to be changed, thereby enabling the separation performance to be changed. More specifically, the separation section 20″ includes at least a recovery pipe 21, a waste liquid storage section 24, a first separation membrane section 25a and a second separation membrane section 25b, a circulation path 26, a separated liquid discharge pipe 27″, a first water discharge pipe 28a and a second water discharge pipe 28b, and a bypass 29.

[0092] The circulation path 26 is sequentially provided with a pump 26a, a first separation membrane unit 25a, a first concentration meter 42a, a second separation membrane unit 25b, and a second concentration meter 42b from upstream to downstream. The circulation path 26 also includes a bypass 29 for bypassing the second separation membrane unit 25b. This configuration allows the formation of a first path that allows the effluent (or separated liquid) to flow only through the circulation path 26, and a second path that allows the effluent (or separated liquid) to flow through a portion of the circulation path 26 and the bypass 29. The first path uses two separation membrane units, the first separation membrane unit 25a and the second separation membrane unit 25b, to separate and remove a larger amount of water from the effluent (or separated liquid), thereby producing a separated liquid with a high organic solvent concentration. On the other hand, the second path separates and removes water from the effluent (or separated liquid) using only the first separation membrane unit 25a, thereby producing a separated liquid with a relatively low organic solvent concentration.

[0093] The first separation membrane unit 25a can separate and remove at least a portion of the water contained in the effluent stored in the effluent storage unit 24. The second separation membrane unit 25b can separate and remove at least a portion of the water contained in the separated liquid discharged from the first separation membrane unit 25a. The separation membranes used in the first separation membrane unit 25a and the second separation membrane unit 25b can be the same as the separation membrane in the separation membrane unit 25 of the first embodiment. The water separated by the first separation membrane unit 25a is discharged from the first water discharge pipe 28a, and the water separated by the second separation membrane unit 25b is discharged from the second water discharge pipe 28b.

[0094] As described above, the circulation path 26 is provided with the first separation membrane unit 25a and the second separation membrane unit 25b, which allow the separated liquid obtained by separating at least a portion of the water contained in the effluent to be returned to the effluent storage unit 24. A pump 26a is provided along the circulation path 26 downstream of the effluent storage unit 24 and upstream of the first separation membrane unit 25a. A first concentration meter 42a is provided downstream of the first separation membrane unit 25a for measuring the concentration of an organic solvent, such as IPA, in the separated liquid produced by the first separation membrane unit 25a. A second concentration meter 42b is also provided downstream of the second separation membrane unit 25b for measuring the concentration of an organic solvent, such as IPA, in the separated liquid produced by the second separation membrane unit 25b. The measured values ​​of the organic solvent concentration in the separated liquid measured by the first concentration meter 42a and the second concentration meter 42b are input to the control unit 130.

[0095] The detour path 29 is provided so that the separated liquid produced in the first separation membrane section 25a flows bypassing the second separation membrane section 25b. More specifically, the detour path 29 branches off from the circulation path 26 downstream of the first concentration meter 42a and merges with the circulation path 26 downstream of the second concentration meter 42b. A first three-way valve 44 is provided at the branching point where the detour path 29 branches off from the circulation path 26, and a second three-way valve 45 is provided at the junction where the detour path 29 merges with the circulation path 26. By providing the first three-way valve 44 at the branching point, the flow path of the separated liquid flowing through the circulation path 26 can be diverted to the detour path 29. By providing the second three-way valve 45 at the junction, the flow path of the separated liquid flowing through the detour path 29 can be diverted to the circulation path 26. The first three-way valve 44 and the second three-way valve 45 are electrically and independently connected to the control unit 130, and the flow path changes by the first three-way valve 44 and the second three-way valve 45 are controlled by operation commands from the control unit 130.

[0096] Further, a first filter 43a and a second filter 43b are sequentially provided from upstream to downstream along the route of the detour 29. Furthermore, a separated liquid discharge pipe 27" is connected between the first filter 43a and the second filter 43b in the detour 29. The first filter 43a and the second filter 43b can remove impurities such as solids such as particles and metal ions contained in the separated liquid. When removing metal ions, for example, an ion exchange resin can be used as the first filter 43a and the second filter 43b.

[0097] The separated liquid discharge pipe 27" branches off from the bypass 29 and is connected to the separated liquid storage section 30. A three-way valve 43c is provided at the branching point where the separated liquid discharge pipe 27" branches off from the bypass 29. By providing the three-way valve 43c at the branching point, the flow path of the separated liquid flowing through the bypass 29 can be changed to the separated liquid discharge pipe 27". The three-way valve 43c is electrically connected to the control section 130, and the change of flow path by the three-way valve 43c is controlled by an operation command from the control section 130.

[0098] [Substrate Processing Method] Next, a substrate processing method using the substrate processing apparatus 100 of this embodiment will be described below. As in the first and second embodiments, the substrate processing method of this embodiment includes a draining process of draining the processing liquid after substrate processing, a separation process of recovering the drained liquid and removing at least a portion of the water from the drained liquid, a storing process of independently storing the separated liquids produced in the separation process according to the different concentrations of organic solvent contained in the separated liquid, and a supplying process of supplying a processing liquid containing at least one of the separated liquids independently stored in the storing process to the front surface Wf of the substrate W. Note that in this embodiment, the draining process is the same as in the second embodiment, and the supplying process is the same as in the first embodiment, so that their description will be omitted below.

[0099] In the separation process, at least a portion of the water contained in the effluent stored in the effluent storage section 24 is removed. When removing water from the effluent in the first path, the pump 26a is operated to circulate the effluent stored in the effluent storage section 24 through the circulation path 26. The effluent flowing through the circulation path 26 has at least a portion of the water separated and removed in a first separation membrane section 25a provided midway through the circulation path 26. The effluent from which at least a portion of the water has been removed is discharged as a separated liquid from the first separation membrane section 25a. The water separated by the first separation membrane section 25a is discharged from a first water discharge pipe 28a. Furthermore, the concentration of the organic solvent contained in the separated liquid discharged from the first separation membrane section 25a is measured by a first concentration meter 42a. The measured organic solvent concentration is input to the control unit 130. If it is determined that the measured organic solvent concentration does not reach a predetermined value, no operational command is issued to the first three-way valve 44 to change the flow path, and the separated liquid is supplied to the second separation membrane unit 25b. Furthermore, at least a portion of the water contained in the separated liquid is removed in the second separation membrane unit 25b. The water separated by the second separation membrane unit 25b is discharged through the second water discharge pipe 28b. The control unit 130 also issues an operational command to the second three-way valve 45 to prevent communication between the circulation path 26 and the bypass path 29. As a result, the separated liquid from which water has been further removed by the second separation membrane unit 25b flows directly through the circulation path 26 and is returned to the waste liquid storage unit 24. The circulation of the separated liquid in the circulation path 26 continues until the organic solvent concentration measured by the second concentration meter 42b reaches a predetermined value. As a result, more water is removed, resulting in a separated liquid with a higher organic solvent concentration, which is then stored in the waste liquid storage unit 24.

[0100] On the other hand, when water is removed from the effluent in the second path, the effluent stored in the effluent reservoir 24 is circulated through the circulation path 26 by operating the pump 26a and supplied to the first separation membrane unit 25a. After at least a portion of the water in the effluent is removed by the first separation membrane unit 25a, the concentration of the organic solvent contained in the separated liquid obtained is measured by the first concentration meter 42a. The measured organic solvent concentration is input to the control unit 130, and if it is determined that the measured value has reached a predetermined value, the control unit 130 issues an operation command to the first three-way valve 44 to change the flow path from the circulation path 26 to the bypass path 29. As a result, the separated liquid is sent to the bypass path 29. Here, when the separated liquid is to be supplied to the separated liquid storage section 30, the control section 130 also issues an operational command to the three-way valve 43c to change the flow path from the bypass 29 to the separated liquid discharge pipe 27". As a result, the separated liquid flowing through the bypass 29 is sent to the separated liquid storage section 30 via the separated liquid discharge pipe 27". On the other hand, when the separated liquid is to be stored in the effluent storage section 24, the control section 130 does not issue an operation command to the three-way valve 43c to change its flow path from the bypass 29 to the separated liquid discharge pipe 27". The control section 130 also issues an operation command to the second three-way valve 45 to change its flow path from the bypass 29 to the downstream side of the circulation path 26. As a result, the separated liquid flowing through the bypass 29 merges with the circulation path 26 and is then returned to the effluent storage section 24. Note that a first filter 43a and a second filter 43b are provided midway along the bypass 29. Therefore, impurities such as particles are removed from the separated liquid supplied to the effluent storage section 24 and the separated liquid storage section 30. Furthermore, during the separation process, it is preferable that the first valve 32b of the first separated liquid storage section 32, the second valve 33b of the second separated liquid storage section 33, and the third valve 34b of the third separated liquid storage section 34 are closed by an operation command from the control section 130.

[0101] In the storing step, the control unit 130 issues an operational command to open one of the first valve 32b, the second valve 33b, and the third valve 34b and close the other valves based on the measured values ​​of the concentration of the organic solvent in the separated liquid by the first concentration meter 42a and the second concentration meter 42b of the separation unit 20''. For example, when the concentration of the organic solvent in the separated liquid is the lowest, the control unit 130 issues an operational command to open the first valve 32b and close the second valve 33b and the third valve 34b. As a result, the separated liquid with the lowest concentration of the organic solvent is stored in the first valve 32b. The separated liquid is supplied to the first separated liquid storage tank 32c via the supply pipe 32a and stored in the first separated liquid storage tank 32c. In this manner, in this step, the separated liquid can be stored in either the first separated liquid storage tank 32c, the second separated liquid storage tank 33c, or the third separated liquid storage tank 34c for each different organic solvent concentration. In the storage step, the first to third separated liquids stored independently in either the first separated liquid storage unit, the second separated liquid storage unit, or the third separated liquid storage unit are reused as treatment liquid in the supply step, in the same manner as in the first and second embodiments.

[0102] (Other Matters) In the above description, the most preferred embodiment of the present invention has been described, but the present invention is not limited to this embodiment, and various modifications are possible within the scope of the technical idea of ​​the present invention as set forth in the claims.

[0103] For example, in the first to third embodiments, an example has been described in which three separated liquid storage sections are provided: a first separated liquid storage section, a second separated liquid storage section, and a third separated liquid storage section. However, the present invention is not limited to this embodiment, and it is sufficient that at least two separated liquid storage sections are provided. In this case, the configuration of the supply section can also be appropriately changed depending on the number of separated liquid storage sections. More specifically, depending on the number of separated liquid storage sections, the number of separated liquid supply pipes for supplying separated liquid to the multiple valves, and the number of valves, pumps, and flow rate control valves provided along the route of the separated liquid supply pipes can be appropriately changed.

[0104] Furthermore, in the first to third embodiments, the case where the water separated from the wastewater (or separated liquid) by the separation membrane unit is discarded through a water discharge pipe has been described as an example. However, the present invention is not limited to this embodiment, and the separated water may be reused. In this case, for example, the water discharge pipe for discarding the water may be connected to a water reservoir of a water supply unit for supplying unused water. In this way, the water separated by the separation membrane unit can be included in the treatment liquid in place of unused water and reused.

[0105] 1: substrate processing unit, 2, 2', 2": recovery and recycling unit, 13: supply unit, 13a: nozzle, 13b: multiple valve, 13c: supply pipe, 13d: organic solvent supply unit, 13e: water supply unit, 14: anti-scattering cup, 20, 20', 20": separation unit, 21: recovery pipe, 21a: valve, 21b: concentration meter, 22: intermediate waste liquid storage unit, 23: waste liquid discharge pipe, 23a: valve, 23b: pump, 24: waste liquid storage unit, 24a: waste liquid temperature adjustment unit, 25: separation membrane unit, 25a: first separation unit Membrane separation section, 25b: second separation membrane section, 26: circulation path, 26a: pump, 26b: concentration meter, 27, 27', 27": separated liquid discharge pipe, 27a: filter, 28: water discharge pipe, 28a: first water discharge pipe, 28b: second water discharge pipe, 29: bypass path, 30: separated liquid storage section, 31: concentration meter, 31a: nozzle, 32: first separated liquid storage section, 32a: first supply pipe, 32b: first valve, 32c: first separated liquid storage tank, 32d: first separated liquid circulation path, 32e: first separated liquid supply pipe, 3 2f: first pump, 32g: first filter, 33: second separated liquid storage section, 33a: second supply pipe, 33b: second valve, 33c: second separated liquid storage tank, 33d: second separated liquid circulation path, 33e: second separated liquid supply pipe, 33f: second pump, 33g: second filter, 34: third separated liquid storage section, 34a: third supply pipe, 34b: third valve, 34c: third separated liquid storage tank, 34d: third separated liquid circulation path, 34e: third separated liquid supply pipe, 34f: third pump, 34g : third filter, 41: three-way valve, 42a: first concentration meter, 42b: second concentration meter, 43a: first filter, 43b: second filter, 43c: three-way valve, 44: first three-way valve, 45: second three-way valve, 130: control unit, 131: connection unit, 132: valve, 133: first valve, 134: second valve, 135: third valve, 136: supply pipe, 137: valve, 138: organic solvent reservoir, 139: supply pipe, 141: water reservoir, W: substrate, Wf: surface

Claims

1. A substrate processing apparatus for processing a pattern-formed surface of a substrate, comprising: a separation section for recovering waste liquid discharged after the substrate processing and containing an organic solvent and water, and removing at least a portion of the water from the recovered waste liquid; a plurality of separation liquid storage sections for independently storing separated liquids produced by removing at least a portion of the water from the waste liquid by the separation section, the separated liquids corresponding to different concentrations of the organic solvent contained in the separated liquid; and a supply section for supplying a processing liquid containing at least any of the separated liquids independently stored in the plurality of separation liquid storage sections to the pattern-formed surface of the substrate.

2. A substrate processing apparatus as described in claim 1, wherein the plurality of separation liquid storage sections are provided with a separation liquid circulation path for drawing out the stored separation liquid and returning it to each of the separation liquid storage sections, and a filter for removing impurities contained in the separation liquid is provided midway along the separation liquid circulation path.

3. The substrate processing apparatus of claim 1, wherein the separation section comprises: a waste liquid storage section for storing the recovered waste liquid; a separation membrane section for separating and removing at least a portion of the water from the waste liquid led out from the waste liquid storage section; a circulation path for supplying the waste liquid stored in the waste liquid storage section to the separation membrane section and returning the separated liquid produced in the separation membrane section to the waste liquid storage section; and a water discharge pipe connected to the separation membrane section for discharging the water separated in the separation membrane section.

4. The substrate processing apparatus according to claim 1, wherein the supply section is provided with a multiple valve that selectively supplies the processing liquid, which contains at least one of the separating liquids respectively supplied from the plurality of separating liquid storage sections, to the pattern formation surface.

5. The substrate processing apparatus of claim 4, wherein the supply unit further comprises an organic solvent supply unit which supplies unused organic solvent and a water supply unit which supplies unused water, and the multiple valve mixes the organic solvent supplied from the organic solvent supply unit and / or the water supplied from the water supply unit with the separation liquid supplied from at least one of the plurality of separation liquid storage units to generate the processing liquid.

6. A substrate processing method for processing a pattern-formed surface of a substrate, comprising: a separation step of recovering waste liquid containing an organic solvent and water discharged after the substrate processing and removing at least a portion of the water from the recovered waste liquid; a storage step of independently storing separated liquids produced by removing at least a portion of the water from the waste liquid in the separation step, each separated liquid corresponding to a different concentration of the organic solvent contained in the separated liquid; and a supply step of supplying a processing liquid containing at least any of the separated liquids independently stored to the pattern-formed surface of the substrate.

7. The substrate processing method according to claim 6, wherein the storing step comprises draining the stored separated liquid, removing impurities contained in the drained separated liquid, and then returning the separated liquid for circulation.

8. The substrate processing method according to claim 6, wherein the separation step includes the steps of: storing the recovered waste liquid; separating and removing at least a portion of the water contained in the waste liquid while circulating the stored waste liquid; and discharging the water separated from the waste liquid.

9. The substrate processing method according to claim 6, wherein said supplying step selectively supplies said processing liquid containing at least one of said separating liquids to be supplied to said pattern forming surface.

10. The substrate processing method according to claim 9, wherein the supplying step comprises mixing unused organic solvent and / or unused water with at least one of the separation liquids stored in the storing step to generate the processing liquid.

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