Substrate processing apparatus

Abstract

The invention provides a substrate processing apparatus capable of separating a chemical solution from a mixed solution of the chemical solution and an organic solvent with low energy. The substrate processing apparatus includes a processing unit, a recovery pipe (60a), and a recovery unit (6). The processing unit causes a mixed solution of the chemical solution and the organic solvent to act on the main surface of the substrate. The recovery pipe (60a) has an upstream end connected to the processing unit. The mixed liquid from the processing unit flows into a recovery pipe (60a). The recovery unit (6) includes a separation membrane (72c) that separates the chemical solution from the liquid mixture supplied through the recovery pipe (60a) and increases the concentration of the organic solvent in the liquid mixture.

Description

Technical Field

[0001] This invention relates to a substrate processing apparatus. Background Technology

[0002] Previously disclosed are monolithic substrate processing apparatuses for processing substrates (e.g., Patent Document 1). In Patent Document 1, the substrate processing apparatus supplies an etching solution containing an oxidant, a catalyst, and a moisture regulator to the substrate to etch a molybdenum film on the substrate.

[0003] [Existing Technical Documents]

[0004] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2021-114569 Summary of the Invention

[0006] [The problem the invention aims to solve]

[0007] The etching solution is discarded after being used to etch the substrate. When the moisture conditioner is an organic solvent, disposing of the etching solution containing a large amount of organic solvent requires a significant amount of energy. Therefore, it is considered to reduce the organic solvent content in the etching solution by separating it from the etching solution, for example, through distillation. However, distillation also requires considerable energy, resulting in high operating costs.

[0008] Therefore, the object of the present invention is to provide a substrate processing apparatus that can separate a drug solution from a mixture of a drug solution and an organic solvent with low energy.

[0009] [Problem-solving methods]

[0010] The first embodiment is a substrate processing apparatus comprising: a processing unit for applying a mixture of a pharmaceutical solution and an organic solvent to the main surface of a substrate; a recovery pipe having an upstream end connected to the processing unit for supplying the mixture from the processing unit; and a recovery unit comprising a separation membrane that separates the pharmaceutical solution from the mixture supplied through the recovery pipe, thereby increasing the concentration of the organic solvent in the mixture.

[0011] The second embodiment is a substrate processing apparatus according to the first embodiment, wherein the liquid is a liquid for etching an etched object on the main surface of the substrate, the etched object comprising metal, and the recovery unit further comprises a first metal filter for capturing the metal in the mixture.

[0012] The third embodiment is a substrate processing apparatus according to the second embodiment, wherein the recovery unit comprises: a storage tank into which the mixture flows through the recovery piping; and a circulation piping having an upstream end and a downstream end connected to the storage tank and interposed of the separation membrane and the first metal filter; the first metal filter being disposed upstream of the separation membrane.

[0013] The fourth embodiment is a substrate processing apparatus according to the second or third embodiment, comprising: a recycling tube for allowing the mixture, in which the concentration of the organic solvent has increased, to flow from the recovery unit to the processing unit; and a second metal filter, inserted in the recycling tube, for capturing metals in the mixture.

[0014] [Invention Effects]

[0015] According to the first configuration, the separation membrane separates the drug solution from the mixture. Therefore, for example, it is possible to separate the drug solution from the mixture with less energy than distillation.

[0016] According to the second form, the mixture can be purified.

[0017] According to the third form, the amount of metal flowing into the separation membrane can be reduced, thus reducing the degradation of the separation membrane.

[0018] According to the fourth configuration, a cleaner mixture can be supplied to the processing unit. Attached Figure Description

[0019] Figure 1 This is a top view that schematically illustrates an example of the configuration of a substrate processing apparatus.

[0020] Figure 2 This is a block diagram that roughly represents an example of the internal structure of the control unit.

[0021] Figure 3 This is a diagram that roughly represents an example of the structure of a processing unit.

[0022] Figure 4 This is a diagram that roughly represents an example of the structure of a recycling unit.

[0023] Figure 5 This is a figure that schematically illustrates the configuration of a first other example of a substrate processing apparatus.

[0024] Figure 6 This is a second example of a schematic representation of the configuration of a substrate processing apparatus. Detailed Implementation

[0025] The embodiments will now be described in detail with reference to the accompanying drawings. Furthermore, in the drawings, for ease of understanding, the dimensions or quantities of each part are exaggerated or simplified as needed. Additionally, parts with the same structure and function are labeled with the same symbols, and repeated descriptions are omitted in the following explanation.

[0026] Furthermore, in the following descriptions, the same symbols are used to illustrate the same components, and their names and functions are also the same. Therefore, detailed descriptions of them are sometimes omitted to avoid repetition.

[0027] Furthermore, in the description below, even when ordinal numbers such as "first" or "second" are sometimes used, these terms are used only for convenience to facilitate understanding of the implementation method and are not limited to the order that may be generated by these ordinal numbers.

[0028] When using expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along a direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.), unless otherwise specified, the expression not only strictly indicates the positional relationship but also the state after relative displacement in angle or distance within tolerance or the range to which the same degree of functionality can be obtained. When using expressions indicating equal states (e.g., "same," "equal," "homogeneous," etc.), unless otherwise specified, the expression not only indicates a state of strict quantitative equality but also indicates a state with differences in tolerance or the range to which the same degree of functionality can be obtained. When using expressions indicating shape (e.g., "quadrilateral shape" or "cylindrical shape," etc.), unless otherwise specified, the expression not only strictly indicates the shape geometrically but also indicates a shape with features such as concavity, convexity, or chamfering within the range to which the same degree of effect can be obtained. When using expressions such as "including," "having," "possessing," "comprises," or "has" a constituent element, the expression is not an exclusive expression excluding the existence of other constituent elements. When using the expression "at least one of A, B and C", the expression includes only A, only B, only C, any two of A, B and C, and all of A, B and C.

[0029] <Overall Structure of the Substrate Processing Device>

[0030] Figure 1 This is a top view schematically illustrating an example of the configuration of the substrate processing apparatus 100. The substrate processing apparatus 100 is a monolithic processing apparatus that processes substrates W one by one. The substrate W is, for example, a semiconductor wafer such as silicon semiconductor. The substrate W has, for example, a circular plate shape. The diameter of the substrate W is, for example, about 300 mm, and the thickness of the substrate W is, for example, about 0.5 mm or more and about 3 mm or less. In addition, the substrate W may also be a substrate other than a semiconductor wafer.

[0031] Figure 1 In the example, the substrate processing apparatus 100 includes a transfer block 110, a processing block 120, a recovery unit (recovery device) 6, and a control unit 90. The processing block 120 is the part that mainly processes the substrate W, and the transfer block 110 is the part that transports the substrate W between the outside of the substrate processing apparatus 100 and the processing block 120. The recovery unit 6 is the part that receives the processing liquid after processing the substrate W from the processing block 120.

[0032] The transfer block 110 includes a load port 111 and a first transfer section 112. A substrate receiving container (hereinafter referred to as a carrier) C, which is transferred in from the outside, is placed on the load port 111. A plurality of substrates W are housed in the carrier C in a state in which they are arranged, for example, spaced apart from each other in the vertical direction. Figure 1 In the example, multiple load ports 111 are arranged.

[0033] The first transfer unit 112 is a transfer robot, also known as a transfer robot. The first transfer unit 112 transfers the unprocessed substrate W from the carrier C to the processing block 120. The processing block 120 is capable of processing the substrate W. The first transfer unit 112 transfers the processed substrate W from the processing block 120 to the carrier C of the load port 111.

[0034] Figure 1 In the example, processing block 120 includes multiple processing units 1 and a second conveying unit 122. The second conveying unit 122 is a conveying robot that conveys substrate W between the first conveying unit 112 and the multiple processing units 1. Figure 1 In the example, processing block 120 also includes a mounting section 123. The mounting section 123 is, for example, a frame capable of mounting multiple substrates W in a vertically arranged state. A first transport section 112 transports untreated substrates W from the mounting section 123 to processing unit 1. Processing unit 1 supplies processing liquid to the substrates W, thereby processing the substrates W. The configuration of processing unit 1 will be described below. A second transport section 122 transports processed substrates W from processing unit 1 to the mounting section 123. The first transport section 112 transports processed substrates W from the mounting section 123 to the carrier C of load port 111.

[0035] Figure 1 In the example, multiple (e.g., four) processing units 1 are arranged to surround the second conveying unit 122 in a top view. The second conveying unit 122 can also be referred to as a central robot. Multiple processing units 1 can also be stacked in the vertical direction at various locations in a top view. That is, multiple (four in the figure) towers TW composed of multiple processing units 1 stacked in the vertical direction can also be arranged to surround the second conveying unit 122.

[0036] The recovery unit 6 is connected to the processing unit 1 via piping 60. The processing solution used for processing the substrate W in the processing unit 1 is supplied to the recovery unit 6 via piping 60. An example of the specific configuration of the recovery unit 6 will be described in detail below.

[0037] The control unit 90 provides unified control of the substrate processing apparatus 100. Specifically, the control unit 90 controls the first conveying unit 112, the second conveying unit 122, the processing unit 1, and the recycling unit 6. Figure 2 This is a block diagram that schematically illustrates an example of the internal structure of the control unit 90. The control unit 90 is an electronic circuit, and for example includes a data processing unit 91 and a storage unit 92. Figure 2 In a specific example, the data processing unit 91 and the storage unit 92 are interconnected via a bus 93. The data processing unit 91 may be, for example, a CPU (Central Processing Unit) or other arithmetic processing device. The storage unit 92 may have a non-transitory storage unit (e.g., ROM (Read Only Memory)) 921 and a transient storage unit (e.g., RAM (Random Access Memory)) 922. The control unit 90 may also be connected to a non-transitory storage unit (memory or hard disk) not shown. The non-transitory storage unit 921 may, for example, store a program specifying the processing to be performed by the control unit 90. By executing this program through the data processing unit 91, the control unit 90 can perform the processing specified by the program. Alternatively, some or all of the processing performed by the control unit 90 may be executed by dedicated logic circuits or other hardware.

[0038] <Summary of Processing Unit>

[0039] Figure 3 This diagram is a schematic representation of one example of the configuration of the processing unit 1. Furthermore, it is not necessary for all processing units 1 belonging to the substrate processing apparatus 100 to have this configuration. Figure 3 The illustrated configuration. As long as at least one processing unit 1 of the substrate processing apparatus 100 has Figure 3 The example shown is sufficient.

[0040] As described in detail below, processing unit 1 supplies processing liquid to the main surface (e.g., the upper surface) of substrate W to process the main surface of substrate W. The processing liquid includes, for example, an etching solution. In this case, processing unit 1 etches the etchable object on the main surface of substrate W. The etchable object includes, for example, a metal. The etchable object can also be a metal compound such as a metal nitride film or a metal oxide film. The metal compound is, for example, TiN, TaN, TaAlN, or TiC. A nanosheet FET (Field Effect Transistor) fabrication structure can be formed on the main surface of substrate W. A nanosheet FET is also called a Ribbon FET. In this structure, for example, multiple fin structures are arranged at intervals in a direction perpendicular to the main surface of substrate W. The fin structure includes a sheet-like semiconductor layer and an insulating film surrounding the semiconductor layer. A sacrificial film is disposed around the fin structure. Here, the sacrificial film is the etchable object.

[0041] The processing unit 1 includes a substrate holding section 2 and an ejection section 3. Figure 3 In the example, the processing unit 1 also includes a chamber 10. The chamber 10 has a box-shaped shape, and its internal space corresponds to the processing space for processing the substrate W. A transfer inlet (not shown) that can be opened and closed is provided in the chamber 10. The second transfer unit 122 transfers the unprocessed substrate W into the chamber 10 through the transfer inlet, and transfers the processed substrate W out of the chamber 10 through the transfer inlet.

[0042] A substrate holding part 2 is disposed within the chamber 10, holding the substrate W in a horizontal position while simultaneously rotating the substrate W about the rotation axis Q1. Here, "horizontal position" refers to the position where the thickness direction of the substrate W is along the vertical direction. The rotation axis Q1 is an axis passing through the center of the substrate W and along the vertical direction. This substrate holding part 2 can also be referred to as a rotating chuck. Here, the main surface of the substrate W with a pattern (e.g., a fin structure) corresponds to the upper surface of the substrate W.

[0043] The substrate holding part 2 can hold the substrate W using a chuck, such as a mechanical chuck, a vacuum chuck, an electrostatic chuck, or a Bernoulli chuck. Figure 3 In the example, the substrate holding part 2 is a mechanical chuck type, including a rotating base 21, chuck pins 22, and a rotation drive part 23. The rotating base 21 has a plate-like shape (e.g., a circular plate shape) and is arranged with its thickness direction along the vertical direction. A plurality of chuck pins 22 are equally spaced along the circumference about the rotation axis Q1 on the rotating base 21. The plurality of chuck pins 22 are configured to be displaceable between the holding position and the release position described below. The holding position is the position where the chuck pins 22 abut against the periphery of the substrate W. The substrate W is held by the plurality of chuck pins 22 stopping at their respective holding positions (see reference). Figure 3The release position refers to the position where each suction pin 22 separates from the substrate W. By stopping the multiple suction pins 22 at their respective release positions, the holding of the multiple suction pins 22 on the substrate W is released. The substrate holding part 2 also includes a pin drive part (not shown) that displaces the suction pins 22. The pin drive part includes, for example, a drive source such as a motor or cylinder, and is controlled by the control part 90.

[0044] The rotary drive unit 23 includes a shaft 231 and a motor 232. The upper end of the shaft 231 is connected to the lower surface of the rotating base 21, and the shaft 231 extends from the lower surface of the rotating base 21 along the rotation axis Q1. The motor 232 is controlled by the control unit 90 to rotate the shaft 231 about the rotation axis Q1. As a result, the rotating base 21, the suction pin 22, and the substrate W rotate integrally about the rotation axis Q1.

[0045] The ejector section 3 ejects various processing liquids toward the main surface (upper surface) of the substrate W held by the substrate holding section 2. The processing liquid adhering to the main surface of the substrate W flows radially outward as the substrate W rotates, and splashes outward from the main surface of the substrate W. Thus, the processing liquid acts on the main surface of the substrate W.

[0046] One of the processing solutions is a mixture of chemical solution and organic solvent. The chemical solution is the liquid used to etch the object. Specifically, the chemical solution can be dilute hydrofluoric acid, a mixture of hydrochloric acid, hydrogen peroxide solution, and water (SC2), a mixture of ammonia solution, hydrogen peroxide solution, and water (SC1), or diluted hydrogen peroxide solution. Other etching solutions can also be used. The concentration (vol%) of dilute hydrofluoric acid, for example, in the form of hydrogen fluoride:pure water, can be approximately 1:5 to 1:2000. The concentration (vol%) of SC1, for example, in the form of sulfuric acid:hydrogen peroxide solution:pure water, can be approximately 1:1:5 to 1:1:100. The concentration (vol%) of SC2, for example, in the form of ammonia solution:hydrogen peroxide solution:pure water, can be approximately 1:1:5 to 1:1:100.

[0047] The organic solvent can be isopropanol or methanol. Adding this organic solvent to the solution increases the conductivity of the mixture. The concentration of the organic solvent in the mixture (hereinafter referred to as solvent concentration) can be, for example, 5 vol% or more and 80 vol% or less, or 30 vol% or more and 70 vol% or less. If this mixture is applied to the substrate W to be etched, the electron supply increases, thus activating the etching reaction. Therefore, the etching rate can be increased.

[0048] The surface tension of organic solvents can be higher than that of the chemical solution. In this case, the mixture can easily penetrate between patterns on the substrate W (e.g., between fin structures), thereby enabling more rapid etching of the target object.

[0049] The molecular diameter of organic solvent molecules is larger than that of drug molecules (maximum value). Therefore, as detailed below, recovery unit 6 can utilize the difference in molecular diameter to separate the drug from the mixture after the substrate W has been treated.

[0050] Figure 3 In the example, the ejection section 3 includes a nozzle 4. The nozzle 4 is, for example, a straight nozzle that ejects a column of processing liquid. The nozzle 4 is disposed above the substrate W held by the substrate holding section 2 within the chamber 10. The nozzle 4 ejects the processing liquid toward the main surface of the substrate W.

[0051] Figure 3 In the example, multiple nozzles 4 are provided, one of which is a mixing nozzle 4a. The downstream end of the mixing pipe 41a is connected to the nozzle 4a, and the upstream end of the mixing pipe 41a is connected to the mixing section 45a. The downstream ends of the drug supply pipe 43a and the solvent supply pipe 44a are also connected to the mixing section 45a. Figure 3 In this example, the drug supply pipe 43a includes multiple independent supply pipes 431 corresponding to the various liquids constituting the drug solution. Here, as an example, the drug solution is SC2. Therefore, independent supply pipes 431 are provided for hydrochloric acid, hydrogen peroxide, and pure water. Organic solvents flow through solvent supply pipe 44a.

[0052] The mixing unit 45a mixes the liquid medicine flowing in from the liquid medicine supply pipe 43a with the organic solvent flowing in from the solvent supply pipe 44a. The mixing unit 45a can be a multi-way valve. For example, the mixing unit 45a includes a liquid medicine mixing valve 451a and a solvent mixing valve 452a. Figure 3 In the example, the drug solution mixing valve 451a includes multiple independent mixing valves 451 corresponding to the various liquids constituting the drug solution. For example, it includes an independent mixing valve 451 for hydrochloric acid, an independent mixing valve 451 for hydrogen peroxide water, and an independent mixing valve 451 for pure water. Each independent mixing valve 451 allows its respective liquid to pass through the mixing pipe 41a at a flow rate corresponding to its own opening. The solvent mixing valve 452a allows organic solvents to pass through the mixing pipe 41a at a flow rate corresponding to its own opening. The drug solution mixing valve 451a and the solvent mixing valve 452a are controlled by the control unit 90. Furthermore, the mixing unit 45a is not necessarily limited to a multi-way valve; it may also consist of connections between pipes and flow control valves connected to each pipe.

[0053] A supply valve 42a is inserted into the mixing pipe 41a, thereby switching the opening and closing of the mixing pipe 41a. The supply valve 42a is controlled by the control unit 90.

[0054] Figure 3In the example, the nozzle 4a is configured to be movable by the motion drive unit 46a. The motion drive unit 46a moves the nozzle 4a between a processing position and a standby position, as described below. The processing position is the position where the nozzle 4a ejects the mixture, for example, a position facing the center of the substrate W in the vertical direction (see reference). Figure 3 The standby position is the position where the nozzle 4a does not eject the mixture, for example, a position further radially outward than the substrate W. The movement drive unit 46a includes, for example, a drive source such as a motor, and a power transmission unit that connects the drive source and the nozzle. The power transmission unit includes, for example, an arm rotation mechanism or a ball screw mechanism.

[0055] Figure 3 In the example, a rinsing fluid nozzle 4b is also shown as nozzle 4. Nozzle 4b is connected to the downstream end of supply pipe 41b, and the upstream end of supply pipe 41b is connected to a rinsing fluid supply source. The rinsing fluid is, for example, pure water. A supply valve 42b and a flow regulating valve 43b are inserted into supply pipe 41b. Supply valve 42b switches the opening and closing of supply pipe 41b, and flow regulating valve 43b regulates the flow rate of rinsing fluid flowing through supply pipe 41b. Supply valve 42b and flow regulating valve 43b are controlled by control unit 90. Nozzle 4b is configured to be movable by movement drive unit 46b. Movement drive unit 46b moves nozzle 4b between a processing position and a standby position. Movement drive unit 46b has, for example, the same configuration as movement drive unit 46a and is controlled by control unit 90.

[0056] After the processing unit 1 supplies the mixture to the substrate W, it supplies the rinsing liquid to the substrate W. Thus, the mixture on the main surface of the substrate W can be rinsed away with the rinsing liquid.

[0057] Figure 4 In the example, nozzle 4c for organic solvents is also shown as nozzle 4. Nozzle 4c is connected to the downstream end of supply pipe 41c, and the upstream end of supply pipe 41c is connected to an organic solvent supply source. Supply pipe 41c is interposed with supply valve 42c and flow regulating valve 43c. Supply valve 42c switches the opening and closing of supply pipe 41c, and flow regulating valve 43c regulates the flow rate of organic solvent flowing through supply pipe 41c. Supply valve 42c and flow regulating valve 43c are controlled by control unit 90. Nozzle 4c is configured to be movable by movement drive unit 46c. Movement drive unit 46c moves nozzle 4c between processing position and standby position. Movement drive unit 46c has, for example, the same configuration as movement drive unit 46a and is controlled by control unit 90.

[0058] After supplying the rinsing solution to the substrate W, the processing unit 1 supplies an organic solvent to the substrate W. This allows the rinsing solution on the main surface of the substrate W to be rinsed away using the organic solvent. Here, the organic solvent is more volatile than the rinsing solution.

[0059] Processing unit 1 dries substrate W after supplying organic solvent. For example, substrate W is dried by increasing the rotational speed of substrate W through substrate holding part 2 (so-called rotary drying).

[0060] Figure 3 In the example, processing unit 1 is provided with multiple baffles 5. Each baffle 5 has a cylindrical shape with the rotation axis Q1 as its central axis and surrounds the substrate holding part 2. The multiple baffles 5 are arranged concentrically. Each baffle 5 is configured to be raised and lowered by a lifting drive unit 52. The lifting drive unit 52 raises and lowers each baffle 5 between an upper position and a lower position. The upper position is when the upper end of the baffle 5 is located above the substrate W held by the substrate holding part 2. In this state, the baffle 5 can catch the processing liquid splashed from the periphery of the substrate W. For example, the lifting drive unit 52 includes a drive source such as a motor and a power transmission part such as a cam mechanism. The lifting drive unit 52 is controlled by a control unit 90.

[0061] Each baffle 5 is used separately depending on the type of processing liquid. For example, the outer baffle 5 is used for the mixing liquid. Specifically, when the lifting drive unit 52 only positions the outer baffle 5 in the upper position, the nozzle 4a sprays the mixing liquid toward the main surface of the substrate W. As a result, the mixing liquid splashed from the periphery of the substrate W is caught by the outer baffle 5 and flows down along the inner peripheral surface of the baffle 5.

[0062] Figure 3 In the example, a receiving cup 53 is provided corresponding to each baffle 5. The receiving cup 53 has an annular (e.g., circular) recess (groove) surrounding the rotation axis Q1. Each receiving cup 53 receives the processing liquid flowing down the inner circumferential surface of the corresponding baffle 5. The upstream end of the piping 60 is connected to, for example, the bottom of each receiving cup 53. The processing liquid received by each receiving cup 53 is discharged to the outside of the processing unit 1 through the piping 60.

[0063] The mixture caught by the outer baffle 5 is collected by the corresponding cup 53 and flows into the corresponding pipe 60. Hereinafter, the pipe 60 into which the mixture flows will also be referred to as the recovery pipe 60a.

[0064] <Recycling Unit 6>

[0065] Figure 4 This is a diagram that schematically illustrates an example of the configuration of the recovery unit 6. The recovery unit 6 is connected to the processing unit 1 via a mixture recovery pipe 60a. Figure 4 In the example, a recovery valve 61 is inserted into the recovery piping 60a. The recovery valve 61 switches the opening and closing of the recovery piping 60a. The recovery valve 61 is controlled by the control unit 90.

[0066] The mixture after treatment of substrate W in processing unit 1 (hereinafter also referred to as the treated mixture) is supplied to recovery unit 6 through recovery piping 60a. Recovery unit 6 includes a membrane separator 72. The membrane separator 72 separates the drug solution from the treated mixture, thereby increasing the solvent concentration of the mixture. Hereinafter, an example of the configuration of recovery unit 6 will be specifically described.

[0067] Figure 4 In the example, the recovery unit 6 includes a storage tank Tk1 and a circulation section 7. The downstream end of the recovery pipe 60a is connected to the storage tank Tk1. Therefore, the processed mixture from the processing unit 1 flows into the storage tank Tk1 through the recovery pipe 60a. The storage tank Tk1 stores the mixture.

[0068] Furthermore, a buffer tank (not shown) may also be inserted into the recovery piping 60a. In this case, a pump or other liquid delivery unit and a supply valve may be inserted into the recovery piping 60a between the buffer tank and the storage tank Tk1. In this case, the processed mixture from the processing unit 1 is temporarily stored in the buffer tank and then supplied from the buffer tank to the storage tank Tk1.

[0069] The circulation unit 7 includes a circulation piping 71, a membrane separator 72, a liquid delivery unit 73, and a circulation valve 74. The circulation piping 71 forms a circulation path for the mixture stored in the storage tank Tk1 to circulate in a manner that allows it to flow out of the storage tank Tk1 and return to the storage tank Tk1. The upstream end of the circulation piping 71 is connected to, for example, the bottom of the storage tank Tk1, and the downstream end of the circulation piping 71 is connected to, for example, the upper part of the storage tank Tk1.

[0070] A membrane separator 72 is inserted into a circulation pipe 71. The membrane separator 72 includes a housing containing a first path 72a, a second path 72b, and a separating membrane 72c. The first path 72a is inserted into the circulation pipe 71, forming part of the circulation path of the circulation section 7. Therefore, the mixture passes through the first path 72a. The separating membrane 72c separates the first path 72a and the second path 72b. The separating membrane 72c is a membrane that allows the drug solution in the mixture to pass through while almost blocking the organic solvent. A portion of the drug solution in the mixture flowing into the first path 72a passes through the separating membrane 72c and flows into the second path 72b.

[0071] Separation membrane 72c is a microporous membrane that separates the drug solution from the organic solvent based on the difference in molecular diameter between the drug solution and the organic solvent. The molecular diameter of the drug solution is smaller than that of the organic solvent. The size of the pores in separation membrane 72c is set such that it substantially blocks the molecules of the organic solvent while allowing the molecules of the drug solution to pass through. Therefore, the molecules of the drug solution can pass through the pores of separation membrane 72c, while the molecules of the organic solvent can hardly pass through them. The difference in molecular diameter between the organic solvent and the drug solution can be, for example, [missing information]. The above can also be used for That's all. For example, the molecular diameter of isopropanol is approximately... The largest molecular diameter of the compounds that make up the drug solution (e.g., SC1, SC2, or ammonia) is approximately the following.

[0072] The separation membrane 72c can be a zeolite membrane, an organic separation membrane, or a CNT (carbon nanotube) separation membrane. Zeolite membranes, for example, are (SiO4) membranes with a tetrahedral structure. 4- (AlO4) 5- Interconnected crystal structures. Organic separation membranes are, for example, organic membranes made of polyvinyl alcohol, chitosan, and polyimide. CNT separation membranes are, for example, membranes obtained by adding carbon nanotubes to membranes such as polyamides. Alternatively, two-dimensional materials can be used as the material for the separation membrane 72c. Two-dimensional materials are materials composed of a single atomic layer, such as molybdenum sulfide (MoS2), or composite atomic layer compounds of early transition metals (such as titanium or vanadium) and light elements (carbon or nitrogen). Alternatively, MOF (Metal Organic Frameworks) materials or carbon materials (such as graphene or graphene oxide) can also be used as the material for the separation membrane 72c. Here, a zeolite membrane is used as the separation membrane 72c.

[0073] The upstream end of the discharge pipe 78 is connected to the second path 72b. The liquid (mainly the pharmaceutical solution) that has passed through the separation membrane 72c in the mixture is discharged to the outside (e.g., the drainage treatment unit of a plant equipment) through the discharge pipe 78. A pressure-reducing pump for pressurizing the second path 72b can also be installed in the discharge pipe 78. Figure 4 As shown, a discharge valve 79 may also be inserted into the discharge pipe 78. The discharge valve 79 switches the opening and closing of the discharge pipe 78. The discharge valve 79 is controlled by the control unit 90.

[0074] The liquid delivery unit 73 is inserted into the circulation piping 71. Figure 4 In this example, the liquid delivery unit 73 is located upstream of the membrane separator 72. The liquid delivery unit 73 is, for example, a pump, which delivers the mixture from the upstream end of the circulation piping 71 toward the downstream end. The circulation valve 74 is inserted into the circulation piping 71. Figure 4 In this example, the circulation valve 74 is located upstream of the liquid delivery unit 73. The circulation valve 74 switches the opening and closing of the circulation piping 71. The liquid delivery unit 73 and the circulation valve 74 are controlled by the control unit 90.

[0075] Figure 4In the example, the recovery unit 6 also includes a temperature control unit 75. The temperature control unit 75 is controlled by the control unit 90 to adjust the temperature of the mixture. For example, the temperature control unit 75 can be a heater for heating the mixture. As a specific example, the temperature control unit 75 can be a resistance heater or a radiation heater. Figure 4 In the example, the temperature control unit 75 is installed in the storage tank Tk1 to heat the mixture in the storage tank Tk1. Figure 4 In this example, the temperature control unit 75 is located at the bottom and side of the storage tank Tk1. The temperature control unit 75 adjusts the temperature of the mixture to a suitable temperature for separation by the membrane separator 72. As a specific example, the temperature control unit 75 adjusts the temperature of the mixture to 70 degrees Celsius or higher. Alternatively, the temperature control unit 75 may also be located in the circulation piping 71.

[0076] Figure 4 In the example, a flow meter Sn2 is installed in the circulation piping 71. The flow meter Sn2 outputs a signal corresponding to the flow rate through the circulation piping 71 to the control unit 90. Based on the signal received from the flow meter Sn2, the control unit 90 controls the liquid delivery unit 73 so that the flow rate of the mixture is within a range suitable for the separation of the membrane separator 72.

[0077] When the control unit 90 opens the circulation valve 74 and the discharge valve 79 while operating the liquid delivery unit 73, the mixture circulates along the circulation path including the storage tank Tk1 and the circulation pipe 71. As a result, the mixture flows into the membrane separator 72. The membrane separator 72 separates the drug solution from the incoming mixture and directs it to the discharge pipe 78. The separated mixture continues to circulate in the circulation pipe 71. Through this separation, the concentration of organic solvent (hereinafter referred to as solvent concentration) in the mixture immediately after passing through the membrane separator 72 in the circulation pipe 71 is higher than the solvent concentration in the mixture before entering the membrane separator 72. Since the circulation unit 7 circulates the mixture through the circulation pipe 71, the mixture continuously flows into the membrane separator 72. Therefore, the membrane separator 72 continuously separates the drug solution from the mixture. As a result, the drug solution continuously flows out from the discharge pipe 78. Because the solvent concentration in the drug solution flowing through the discharge pipe 78 is low, the disposal of the drug solution can be simplified.

[0078] On the other hand, the solvent concentration of the mixture increases over time during the circulation process. Therefore, the solvent concentration of the mixture in storage tank Tk1 increases. This mixture with increased solvent concentration can be reused as an organic solvent. For example, the circulation unit 7 circulates the mixture until the solvent concentration of the mixture in storage tank Tk1 reaches at least a reuse reference value. The reuse reference value is, for example, set in advance. The reuse reference value can be, for example, 80 vol% or more, 85 vol% or more, or 90 vol% or more. Hereinafter, a mixture with a solvent concentration exceeding the reuse reference value will also be referred to as a concentrate.

[0079] Figure 4 In the example, the recovery unit 6 includes a concentration sensor Sn1. The concentration sensor Sn1 measures the solvent concentration of the mixture and outputs an electrical signal representing the measurement result to the control unit 90. Figure 4 In the example, the concentration sensor Sn1 is installed in the circulation piping 71. As a specific example, the concentration sensor Sn1 is installed downstream of the membrane separator 72. Alternatively, the concentration sensor Sn1 can also be installed in the storage tank Tk1. The control unit 90 operates the circulation unit 7 until the solvent concentration measured by the concentration sensor Sn1 reaches at least the reuse reference value.

[0080] Figure 4 In the example, the storage tank Tk1 of the recycling unit 6 is connected to the processing unit 1 via the reuse pipe 65. Figure 4 In this example, the upstream end of the reuse pipe 65 is connected to, for example, the bottom of the storage tank Tk1. The downstream end of the reuse pipe 65 can be connected to the mixing section 45a. In this case, the reuse pipe 65 functions as a solvent supply pipe 44a. A supply valve 66 and a liquid delivery section 67 may also be inserted into the reuse pipe 65. The supply valve 66 switches the opening and closing of the reuse pipe 65. The liquid delivery section 67 delivers concentrated liquid from the storage tank Tk1 toward the mixing section 45a. The supply valve 66 and the liquid delivery section 67 are controlled by the control unit 90.

[0081] With the concentrate stored in the storage tank Tk1, the control unit 90 opens the supply valve 66 and operates the liquid delivery unit 67. This supplies the concentrate in the storage tank Tk1 to the processing unit 1 via the reuse pipe 65. Thus, the organic solvents in the mixture already processed in the processing unit 1 are reused by the processing unit 1 while still contained in the concentrate, thereby reducing the amount of organic solvent used.

[0082] Furthermore, the mixture used for processing substrate W in processing unit 1 may contain components of the object to be etched. If the object to be etched contains a metal, the mixture contains metal (ions). That is, because the mixture dissolves the object to be etched (e.g., the sacrificial film) of substrate W, the metal contained in the object to be etched dissolves in the mixture. This metal may include, for example, at least one of titanium, tantalum, and aluminum. There is a concern that directly reusing the concentrated solution for processing substrate W while it contains a significant amount of this metal could lead to a decrease in etching performance.

[0083] therefore, Figure 4 In the example, recycling unit 6 also includes a first metal filter 76. Figure 4 In the example, the first metal filter 76 is inserted into the circulation piping 71. Figure 3 In the example, the first metal filter 76 is located upstream of the membrane separator 72.

[0084] The first metal filter 76 captures metal (ions) in the mixture. The first metal filter 76 includes, for example, an ion exchange resin and a filter housing containing the ion exchange resin. The ion exchange resin is a synthetic resin having ion exchange groups. When the drug solution flows into the first metal filter 76, the ion exchange groups exchange with the metal ions in the drug solution. Thus, the metal ions are captured by the ion exchange resin. The ion exchange resin may also contain functional groups in the ion exchange groups that can form complexes with the metal ions. Therefore, the first metal filter 76 can capture metal ions with higher selectivity.

[0085] Alternatively, the first metal filter 76 may also include an adsorbent and a filter housing containing the adsorbent. The adsorbent adsorbs metal ions from the pharmaceutical solution. The adsorbent material may include, for example, at least one of activated carbon, zeolite, and silica gel.

[0086] Figure 4 In the example, the first metal filter 76 is located upstream of the membrane separator 72. Therefore, the mixture flows into the membrane separator 72 after passing through the first metal filter 76. That is, the concentration of metals in the mixture (hereinafter referred to as metal concentration) is reduced by the first metal filter 76 before the mixture flows into the membrane separator 72. Therefore, the possibility of metal ions adhering to the separation membrane 72c of the membrane separator 72 can be reduced. Therefore, the degradation of the separation membrane 72c can be reduced.

[0087] Figure 4 In the example, during the circulation of the mixture, the mixture continuously flows into the first metal filter 76. Therefore, the first metal filter 76 continuously captures metals from the mixture. Consequently, the metal concentration of the mixture decreases over time during circulation. By utilizing the circulation through the first metal filter 76, the metal concentration can be further reduced.

[0088] Next, an example of the operation of the recovery unit 6 will be described. The processed mixture from the processing unit 1 flows into the storage tank Tk1. First, the control unit 90 controls the temperature control unit 75 to adjust the temperature of the mixture to a suitable temperature for separation by the membrane separator 72. Then, the control unit 90 opens the circulation valve 74 and the discharge valve 79, and simultaneously activates the liquid delivery unit 73. As a result, the mixture circulates along a circulation path including the storage tank Tk1 and the circulation piping 71. If a pressure reducing pump is installed on the discharge piping 78, the control unit 90 also activates the pressure reducing pump. The solution separated from the mixture by the membrane separator 72 is discharged to the outside through the discharge piping 78, and the solvent concentration in the mixture increases over time during the circulation process.

[0089] With the first metal filter 76 in place, the metal concentration in the mixture during the circulation process decreases over time.

[0090] The control unit 90 circulates the mixture in the circulation unit 7 until the solvent concentration of the mixture in the storage tank Tk1 reaches or exceeds the reuse reference value. Thus, a concentrated solution with a solvent concentration exceeding the reuse reference value is stored in the storage tank Tk1. Alternatively, the control unit 90 can circulate the mixture in the circulation unit 7 until the metal concentration of the mixture in the storage tank Tk1 falls below the metal reference value.

[0091] The recovery unit 6 supplies the concentrated liquid in the storage tank Tk1 to the processing unit 1 through the reuse pipe 65. Specifically, the control unit 90 opens the supply valve 66 and activates the liquid delivery unit 67. As a result, the concentrated liquid in the storage tank Tk1 is supplied to the processing unit 1. Furthermore, the concentrated liquid can be supplied to the processing unit 1 after the operation of the circulation unit 7 has stopped, or it can be supplied to the processing unit 1 in parallel with the operation of the circulation unit 7.

[0092] As described above, in the substrate processing apparatus 100, the separation membrane 72c separates the drug solution from the mixture of drug solution and organic solvent recovered from the self-processing unit 1. Thus, the substrate processing apparatus 100 can separate the drug solution from the mixture with, for example, less energy than distillation.

[0093] The separated liquid is discharged through drain pipe 78. Because the solvent concentration of the liquid is low, the disposal of the liquid can be carried out more easily.

[0094] On the other hand, the solvent concentration of the mixture becomes higher. Figure 4 In the example, the recovery unit 6 supplies the concentrate as an organic solvent to the processing unit 1 via the reuse pipe 65. That is, the organic solvent is reused. Therefore, the amount of organic solvent used can be reduced. In other words, the substrate processing apparatus 100 helps to save organic solvent.

[0095] Furthermore, in the above example, the recovery unit 6 includes a first metal filter 76. The first metal filter 76 captures the metal of the etched object contained in the mixture. Therefore, even if the etching process of the substrate W causes the metal concentration of the processed mixture to increase, the metal concentration of the mixture can be reduced by the first metal filter 76. Therefore, the recovery unit 6 can supply a cleaner concentrate to the processing unit 1. Therefore, the processing unit 1 can supply a mixture containing a cleaner concentrate to the substrate W, thereby enabling the etching of the substrate W while maintaining a high etching rate.

[0096] Figure 5 This is a figure that schematically illustrates the configuration of a first other example of a substrate processing apparatus 100. Figure 5In the example, a supply reservoir Tk2 is provided in the substrate processing apparatus 100. The supply reservoir Tk2 stores an organic solvent (concentrate). The downstream end of the reuse pipe 65 is connected to, for example, the upper part of the supply reservoir Tk2, and the upstream end of the solvent supply pipe 44a is connected to, for example, the bottom of the supply reservoir Tk2. The supply reservoir Tk2 can function as a buffer reservoir. A liquid delivery section (not shown) may also be inserted into the solvent supply pipe 44a.

[0097] Figure 6 This is a diagram schematically illustrating a second alternative embodiment of the configuration of the substrate processing apparatus 100. In this second alternative embodiment, the substrate processing apparatus 100 further includes a second metal filter 77. The second metal filter 77 is inserted into the recycling tube 65. The second metal filter 77 captures metals (ions) in the concentrate. An example of the second metal filter 77 may be the same as the first metal filter 76.

[0098] According to the second example, the metal concentration in the concentrate can be further reduced by using the second metal filter 77. Therefore, the recovery unit 6 can supply a cleaner concentrate to the processing unit 1.

[0099] As described above, the substrate processing apparatus 100 and the substrate processing method have been described in detail, but the above description is illustrative in all respects and the present invention is not limited thereto. Furthermore, the various variations described above can be combined as long as they do not contradict each other. Moreover, it should be understood that multiple variations not illustrated can be assumed without departing from the scope of the present invention.

[0100] [Explanation of Symbols]

[0101] 1: Processing Unit

[0102] 100: Substrate processing apparatus

[0103] 6: Recycling Unit

[0104] 60a: Recycled Piping

[0105] 65: Reuse Pipe

[0106] 71: Circulation piping

[0107] 72c: Separation membrane

[0108] 76: First metal filter

[0109] 77: Second metal filter

[0110] Tk1: Storage tank

[0111] W: Substrate.

Claims

1. A substrate processing apparatus comprising: The processing unit allows the mixture of drug solution and organic solvent to act on the main surface of the substrate; A recovery piping system has a connection at the upstream end of the processing unit for the inflow of the mixture from the processing unit; and The recovery unit includes a separation membrane that separates the drug solution from the mixture supplied through the recovery piping, thereby increasing the concentration of the organic solvent in the mixture.

2. The substrate processing apparatus according to claim 1, wherein The etching solution is a liquid used to etch the main surface of the substrate. The etched object contains metal. The recovery unit also includes a first metal filter that captures metals in the mixture.

3. The substrate processing apparatus according to claim 2, wherein The recycling unit includes: Storage tank, through which the mixture flows in via the recovery piping; and The circulation piping has an upstream end and a downstream end connected to the storage tank, and is interposed with the separation membrane and the first metal filter; The first metal filter is located upstream of the separation membrane.

4. The substrate processing apparatus according to claim 2 or 3, comprising: The reuse tube allows the mixture, whose organic solvent concentration has increased, to flow from the recovery unit to the processing unit; and A second metal filter, inserted in the reuse tube, captures metals in the mixture.

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