Particle removal method and substrate processing apparatus

Abstract

This invention provides a particle removal method and a substrate processing apparatus for effectively removing particles from a processing liquid. The particle removal method removes particles from a processing liquid used to process a substrate. The method includes the following steps: flowing a processing liquid through a processing liquid flow path; supplying microbubbles to the processing liquid flowing through the processing liquid flow path; causing particles in the processing liquid flowing through the processing liquid flow path to adhere to the microbubbles within the processing liquid flow path; and separating and collecting the microbubbles with attached particles from the processing liquid flowing through the processing liquid flow path. The processing liquid flow path may also include a pipe with a bend. In this case, the collection step can also collect microbubbles guided to the tangential direction of the bend in a branch flow path branching from the pipe.

Description

Technical Field

[0001] The present invention relates to a method for removing particles from a processing liquid used to process a substrate, and a substrate processing apparatus having a structure for removing particles from the processing liquid. Prior Technology

[0002] Patent Document 1 discloses an immersion-type substrate processing apparatus comprising a structure for removing particles from a processing solution. Specifically, a bubbler disposed at the bottom of a processing tank sprays bubbles into the processing solution, and a bubble removal unit disposed in a processing solution circulation system removes the bubbles from the processing solution. Particles in the processing solution are adsorbed onto the bubbles and removed along with the bubbles. This eliminates the need for a filter to remove particles. The bubble removal unit removes bubbles by swirling the processing solution, concentrating them at the center of the swirling motion. [Previous Technical Documents] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2006-100493 Summary of the Invention

[0004] [The problem the invention aims to solve] The bubbler installed in the treatment tank is composed of a multi-hole ejector section with multiple ejected bubbles connected to the end of the pipe through which the gas passes (see paragraph 0034 of Patent Document 1). It is believed that the bubbles ejected from this type of bubbler are ordinary bubbles with a diameter of about a few millimeters, i.e., so-called millimeter bubbles. Millimeter bubbles rise rapidly in the treatment liquid and mostly burst and disappear at the water surface.

[0005] Therefore, the residual time in the treatment solution is shorter, resulting in a shorter time for particle adsorption. Furthermore, since most bubbles break and disappear at the surface of the treatment solution tank, the proportion of bubbles remaining until reaching the bubble removal section is relatively small. Correspondingly, the proportion of particles removed along with the bubbles in the bubble removal section is also relatively small, so the particle removal efficiency may not be high.

[0006] Therefore, one embodiment of the present invention provides a particle removal method and a substrate processing apparatus that can effectively remove particles from a treatment liquid. [Technical means to solve the problem]

[0007] An embodiment of the present invention provides a particle removal method and a substrate processing apparatus having the following illustrative features.

[0008] 1. A particle removal method, comprising the steps of removing particles from a processing liquid used to process a substrate: The treatment fluid flows through the treatment fluid flow path; Microbubbles are supplied to the treatment fluid flowing through the above-mentioned treatment fluid flow path; The particles in the treatment fluid flowing through the above-mentioned treatment fluid flow path adhere to the microbubbles within the treatment fluid flow path; and The microbubbles with the aforementioned particles attached are separated and captured from the treatment liquid flowing through the aforementioned treatment liquid path.

[0009] 2. As in the particle removal method of Project 1, the above-mentioned treatment fluid flow path includes piping with bends; The above-described trapping steps trap the fine air bubbles that are guided to the wiring direction of the bend in the above-described pipe branch flow path.

[0010] 3. The particle removal method of Project 2, wherein the piping includes a supply piping that supplies the processing liquid from a processing liquid tank storing the processing liquid to the substrate; The aforementioned bend includes a supply pipe bend disposed on the aforementioned supply pipe.

[0011] 4. The particle removal method of Project 3, wherein the supply piping is connected to a nozzle that sprays the treatment liquid onto the substrate; The aforementioned supply piping bend includes a nozzle front bend located directly in front of the aforementioned nozzle.

[0012] Typically, no other bends are provided in the supply piping between the bend in front of the nozzle and the nozzle outlet.

[0013] 5. As in the particle removal method of Project 4, wherein the nozzle is disposed in a processing chamber that divides the processing space of the substrate; The aforementioned nozzle front bend is disposed within the aforementioned processing chamber.

[0014] 6. The particle removal method of any one of items 2 to 5, wherein the aforementioned curved portion includes a spiral pipe disposed in the aforementioned piping.

[0015] 7. The particle removal method of any of items 2 to 6, wherein the aforementioned curved portion includes an upwardly protruding curved portion.

[0016] 8. The particle removal method of any one of items 1 to 7, wherein the above-mentioned trapping step involves applying an electric field (typically a DC electric field) to the treatment liquid flowing in the treatment liquid flow path, thereby changing the trajectory of the microbubbles in the treatment liquid, guiding the microbubbles to a branch flow path branching off from the treatment liquid flow path and separating them.

[0017] 9. The particle removal method of any one of items 1 to 8, wherein the above-mentioned trapping step uses a filter disposed in the middle of the above-mentioned processing liquid flow path to filter the processing liquid, thereby capturing the above-mentioned fine bubbles, and guides the above-mentioned fine bubbles captured by the above-mentioned filter to a branch flow path branching off from the above-mentioned processing liquid flow path.

[0018] The filters described above are typically designed to allow particles that are not attached to microbubbles to pass through, unlike filters designed to capture particles that exist independently.

[0019] 10. The particulate removal method of any of items 2 to 9, wherein the aforementioned processing fluid flow path includes a return pipe that returns the processing fluid to a processing fluid tank where the processing fluid is stored; It further includes the following steps: guiding a portion of the above-mentioned treatment liquid along with the above-mentioned microbubbles to the above-mentioned branch flow path, so that the above-mentioned treatment liquid guided to the above-mentioned branch flow path is returned to the above-mentioned treatment liquid tank via the above-mentioned return pipe.

[0020] 11. The particulate removal method of Item 10 further includes the step of discarding the treatment liquid in the treatment liquid tank.

[0021] 12. The particulate removal method of Project 11, wherein the waste liquid step discards a portion of the treatment liquid near the surface of the treatment liquid stored in the treatment liquid tank.

[0022] 13. The particle removal method of any one of items 10 to 12, wherein the above-mentioned collection step includes the following steps: separating and collecting the microbubbles with the above-mentioned particles from the treatment liquid flowing in the above-mentioned return piping, and guiding them to the waste flow path for disposal.

[0023] 14. The particle removal method of any one of items 1 to 13, wherein the above-mentioned trapping step involves separating the microbubbles with the above-mentioned particles from the processing liquid flowing through the processing liquid at a plurality of locations in the processing liquid flow path, and guiding them from the plurality of locations to a plurality of branch flow paths that branch off respectively; A portion of the above-mentioned treatment liquid, along with the microbubbles, is guided to each branch flow path; and The particle removal method further includes the steps of: returning the treated liquid, which has been guided to at least one of the plurality of branch flow paths, to the treated liquid storage tank; and The aforementioned treatment fluid, which will be directed to at least one of the aforementioned branch flow paths, will be discarded and will not be returned to the aforementioned treatment fluid tank.

[0024] 15. The particle removal method of any of items 1 to 14, wherein the aforementioned microbubbles include microbubbles and ultrafine bubbles.

[0025] 16. A substrate processing apparatus, comprising: The nozzle supplies the processing liquid to the substrate; The treatment fluid flow path allows the aforementioned treatment fluid to pass through. A bubble generator supplies microbubbles to the treatment liquid flowing through the aforementioned treatment liquid flow path; and The particle separator separates particles attached to the microbubbles by separating and capturing the microbubbles from the processing liquid flowing through the processing liquid path.

[0026] 17. The substrate processing apparatus of item 16, wherein the particle separator comprises: a bend in the piping that forms the processing fluid flow path; and a branch flow path that branches off from the piping in the wiring direction of the bend.

[0027] 18. The substrate processing apparatus of item 17, wherein the bent portion includes a spiral tube disposed on the piping.

[0028] 19. A substrate processing apparatus as described in any of items 16 to 18, wherein the particle separator comprises: an electrode that imparts an electric field (typically a DC electric field) to the processing liquid flowing in the processing liquid flow path; and a branch flow path that guides microbubbles that change due to the electric field.

[0029] 20. A substrate processing apparatus as described in any one of items 16 to 19, wherein the particle separator comprises: a filter disposed in the middle of the processing flow path to filter the processing liquid and capture the microbubbles; and a branch flow path to guide the microbubbles captured by the filter. [Effects of the Invention]

[0030] According to the present invention, by attaching particles in the treatment liquid to microbubbles, capturing and separating the microbubbles in that state, particles in the treatment liquid flowing in the treatment liquid path can be effectively removed. Simple Explanation of the Diagram

[0031] Figure 1 is a schematic top view illustrating the internal layout of a substrate processing apparatus according to one embodiment of the present invention. Figure 2 is a schematic longitudinal sectional view of the substrate processing apparatus. Figure 3 is a schematic diagram showing an example of the configuration of a processing liquid supply device equipped in a substrate processing apparatus. Figures 4A and 4B are schematic cross-sectional views showing an example of the configuration of a particle separator. Figure 5 is a block diagram illustrating the electrical configuration of the main components of the substrate processing device. Figure 6 is a step diagram illustrating the particle removal method performed in the substrate processing apparatus. Figure 7 is a diagram illustrating the configuration of a substrate processing apparatus in another embodiment of the present invention. Figure 8 is a diagram illustrating the configuration of a substrate processing apparatus in further embodiments of the present invention. Figure 9 is a diagram illustrating the configuration of a substrate processing apparatus in further embodiments of the present invention. Figure 10 is a schematic cross-sectional view showing an example of the configuration of a particle separator. Figure 11 is a diagram illustrating the configuration of a substrate processing apparatus in further embodiments of the present invention. Figure 12 is a diagram illustrating the configuration of a substrate processing apparatus in further embodiments of the present invention. Figure 13 is a diagram illustrating the configuration of a substrate processing apparatus in further embodiments of the present invention. Implementation

[0032] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail.

[0033] Figure 1 is a schematic top view illustrating the internal layout of a substrate processing apparatus 1 according to one embodiment of the present invention. Figure 2 is a schematic longitudinal sectional view of the substrate processing apparatus 1.

[0034] The substrate processing apparatus 1 is a single-wafer device for processing substrates W, such as silicon wafers, one by one. In this embodiment, the substrate W is a circular plate-shaped substrate. The substrate processing apparatus 1 includes a plurality of processing towers 2A to 2D (processing sections) that process the substrate W with a processing liquid such as a chemical solution or a cleaning solution. The plurality of processing towers 2A to 2D are collectively referred to as processing tower 2. The substrate processing apparatus 1 further includes: a processing liquid supply device 3 that supplies processing liquid to the plurality of processing towers 2A to 2D; and fluid units 4A to 4D, which are provided corresponding to each processing tower 2A to 2D and house piping for supplying processing liquid to the processing towers 2A to 2D.

[0035] Each processing tower 2A-2D contains a plurality of (e.g., 3) processing units 20 stacked on top of each other (see Figure 2). The processing unit 20 is a monolithic processing unit that processes each substrate W one by one. The plurality of processing units 20 have, for example, the same configuration.

[0036] The substrate processing apparatus 1 further includes: a loading port LP for holding a carrier C that holds a plurality of substrates W to be processed by the processing unit 20; a transfer robot, namely a transfer robot IR and a central robot CR, which transfer the substrates W between the loading port LP and the processing unit 20; and a control device 7 that controls the substrate processing apparatus 1.

[0037] The substrate processing apparatus 1 further includes a horizontally extending transport path 5. The transport path 5 extends linearly from the transfer robot IR to the central robot CR. The transfer robot IR transports the substrate W between the carrier C and the central robot CR. The central robot CR transports the substrate W between the transfer robot IR and the processing unit 20.

[0038] A plurality of processing towers 2 are symmetrically arranged across the conveyor path 5. Each of the plurality of processing towers 2 on either side of the conveyor path 5 is arranged along the direction of extension of the conveyor path 5 (extension direction X). In this embodiment, two processing towers 2 are arranged on each side of the conveyor path 5.

[0039] Of the plurality of processing towers 2A-2D, the two processing towers 2 closest to the transfer robot IR side are designated as processing tower 2A and processing tower 2B, respectively. Processing tower 2A and processing tower 2B face each other across the transfer path 5. Of the plurality of processing towers 2A-2D, the two processing towers 2 furthest from the transfer robot IR side are designated as processing tower 2C and processing tower 2D, respectively. Processing tower 2C and processing tower 2D face each other across the transfer path 5. Processing tower 2A and processing tower 2C are arranged in the extension direction X. Processing tower 2B and processing tower 2D are arranged in the extension direction X. Corresponding fluid units 4A-4D are adjacent to each processing tower 2A-2D from the extension direction X.

[0040] The processing fluid supply device 3 includes a processing fluid supply source R. The substrate processing device 1 includes a housing 6, which is disposed on the opposite side of the transfer robot IR in the extension direction X, and houses the processing fluid supply source R. The processing fluid supply source R is disposed within the housing 6 at a position closer to the processing tower 2D on the other side of the processing towers 2C and 2D disposed on both sides of the transfer path 5 than the processing tower 2C on one side of the processing towers 2C and 2D disposed on both sides of the transfer path 5.

[0041] Figure 3 is a schematic diagram showing an example of the configuration of the processing liquid supply device 3 equipped in the substrate processing apparatus 1.

[0042] The processing liquid supply device 3 includes: tower supply piping 22A-22D, which distributes and supplies the processing liquid in the processing liquid tank 21 to a plurality of processing towers 2A-2D. The processing liquid supply source R includes: a processing liquid tank 21, which stores the processing liquid; and a common piping 24, which connects the processing liquid tank 21 to the upstream end of the plurality of tower supply piping 22A-22D.

[0043] For the processing solution tank 21, a chemical solution (stock solution) of a specified concentration is supplied from the chemical solution supply source 10 via the chemical solution supply piping 11, and DIW (deionized water) is supplied from the DIW supply source 13 via the DIW supply piping 14. In this way, the chemical solution (stock solution) is diluted with DIW in the processing solution tank 21 to prepare a chemical solution of appropriate concentration suitable for the processing of the substrate W. A chemical solution valve 12 is installed in the chemical solution supply piping 11, which can be used to switch the supply / stop of the chemical solution. A DIW valve 15 is installed in the DIW supply piping 14, which can be used to switch the supply / stop of DIW. The chemical solution supply source 10 typically includes a stock solution tank for storing the stock solution. The DIW supply source 13 typically includes DIW piping from the utility equipment of the factory where the substrate processing apparatus 1 is installed.

[0044] A drain pipe 17 is connected to the bottom of the treatment liquid tank 21. A drain valve 18 is installed on the drain pipe 17 to open and close its flow path. By opening the drain valve 18, the treatment liquid in the treatment liquid tank 21 can be discharged and disposed of through the drain pipe 17.

[0045] Multiple tower supply pipes 22A~22D branch off from the downstream end of the common pipe 24. When referring to the tower supply pipes 22A~22D collectively, they are called tower supply pipe 22.

[0046] A pump 30 and a bubble generator 31 are sequentially installed from the upstream side of the common piping 24. Pump 30 pumps the processed liquid within the common piping 24 downstream. The bubble generator 31 supplies microbubbles to the processed liquid flowing in the common piping 24. Therefore, downstream of the bubble generator 31, the processed liquid contains microbubbles that flow along with the liquid. The processed liquid containing these microbubbles is then supplied to the tower via supply piping 22A-22D.

[0047] The components of the processing liquid supply device 3 associated with each processing tower 2A to 2D have substantially the same configuration in all processing towers 2A to 2D. Therefore, the following description focuses on the components corresponding to the first processing tower 2A in the processing liquid supply device 3. Figure 3 shows the configuration around the first processing tower 2A and the corresponding tower supply piping 22A, omitting the diagrams showing the configurations associated with other processing towers 2B to 2D and other tower supply piping 22B to 22D.

[0048] Each processing unit 20 of the first processing tower 2A is a single-piece processing unit. The processing unit 20 includes: a rotating chuck 40, which holds a substrate W in a horizontal position on one side and rotates the substrate W about a vertical rotation axis A1 passing through the center of the substrate W on the other side; a first nozzle 41 and a second nozzle 42, which supply processing liquid to the substrate W; a cup 43, which surrounds the rotating chuck 40; and a processing chamber 44, which houses the rotating chuck 40, the first nozzle 41, the second nozzle 42 and the cup 43, and divides the processing space for processing the substrate W.

[0049] The processing chamber 44 is provided with an inlet / outlet (not shown) for moving the substrate W into or out of the processing chamber 44. The processing chamber 44 is equipped with a baffle unit (not shown) for opening and closing the inlet / outlet.

[0050] Although the rotating chuck 40 is not shown in the figure, it typically includes a disc-shaped rotating base, a rotating shaft connected to the center of the lower surface of the rotating base, and an electric motor that imparts rotational force to the rotating shaft.

[0051] In this embodiment, the first nozzle 41 and the second nozzle 42 are respectively arranged to spray processing liquid towards the rotation center of the upper surface of the substrate W. These nozzles can be fixed or movable. Processing liquid, such as a chemical solution, stored in the processing liquid tank 21 of the processing liquid supply source R, is supplied to the first nozzle 41 via the tower supply pipe 22A and the unit supply pipe 23 branching from the tower supply pipe 22A to each processing unit 20 within the tower. Cleaning liquid, such as a cleaning liquid, is supplied to the second nozzle 42 via pipe 51 from a cleaning liquid supply system 50 having a different supply source than the processing liquid supply source R. A valve 52 is installed in pipe 51 to switch whether processing liquid is supplied to the second nozzle 42.

[0052] The solution may be, for example, hydrofluoric acid (hydrogen fluoride water: HF). The solution is not limited to hydrofluoric acid; it may also be a liquid containing at least one of the following: sulfuric acid, acetic acid, nitric acid, hydrochloric acid, buffered hydrofluoric acid (BHF), dilute hydrofluoric acid (DHF), ammonia, hydrogen peroxide water, organic acids (e.g., citric acid, oxalic acid), organic bases (e.g., TMAH: tetramethylammonium hydroxide), surfactants, and corrosion inhibitors. Examples of mixtures of these solutions include SPM (sulfuric acid-hydrogen peroxide water mixture), SC1 (ammonia-hydrogen peroxide water mixture), and SC2 (hydrochloric acid-hydrogen peroxide water mixture). The solution typically contains water and is therefore an aqueous solution.

[0053] Cleaning solutions can be, for example, deionized water (DIW). Cleaning solutions are not limited to DIW; they can also be carbonated water, electrolyzed water, ozone water, hydrochloric acid diluted to a concentration of approximately 10-100 ppm, or reduced water (hydrogen water). Cleaning solutions typically contain water.

[0054] Unit supply piping 23 is a branch of tower supply piping 22A, and supplies the treatment liquid to the first nozzle 41 of the corresponding treatment unit 20.

[0055] For each of the plurality of unit supply pipes 23, a supply valve 36, a supply flow regulating valve 37, and a supply flow meter 38 are sequentially installed upstream of the first nozzle 41. Each supply valve 36 switches whether or not processing fluid is supplied to the first nozzle 41. Each supply flow regulating valve 37 adjusts the flow rate of the processing fluid flowing through the unit supply pipe 23 to the first nozzle 41. Each supply flow meter 38 detects the flow rate of the processing fluid flowing through the unit supply pipe 23 to the first nozzle 41. The supply valve 36 is, for example, a switch valve. The supply flow regulating valve 37 is, for example, a motor needle valve.

[0056] The tower supply piping 22A includes: an upstream piping section 60 housed within the casing 6; an upward piping section 61 and a downward piping section 62, both housed within the fluid unit 4A; and a relay piping section 63 connecting the upstream piping section 60 and the upward piping section 61, spanning between the casing 6 and the fluid unit 4A. The upward piping section 61 and the downward piping section 62 are each constructed as substantially straight pipes extending vertically. The processing fluid flows upward within the upward piping section 61 and downward within the downward piping section 62. A plurality of unit supply pipes 23 branch from the downward piping section 62.

[0057] The upward piping section 61 and the downward piping section 62 are connected by a supply piping bend 64 (curved section) consisting of an upwardly convex curved (inverted U-shaped) piping section. Therefore, the treatment fluid flowing upward through the upward piping section 61 bends downward in the supply piping bend 64 and flows downward through the downward piping section 62. A branch pipe 65, forming a branch flow path in the connection direction of its flow path, is connected to the supply piping bend 64. Therefore, a portion of the treatment fluid flowing through the supply piping bend 64 is guided to the branch pipe 65. The branch pipe 65 is connected to the return piping 66. The return piping 66 is a pipe that returns the treatment fluid to the treatment fluid tank 21.

[0058] The unit supply piping 23 has a horizontally extending straight section 23a, a downward section 23b extending downward toward the first nozzle 41, and a nozzle-front bend 23c connecting the horizontal section 23a and the downward section 23b. The nozzle-front bend 23c is disposed within the processing chamber 44. The nozzle-front bend 23c is a bend directly in front of the first nozzle 41, and there is no flow path between the nozzle-front bend 23c and the first nozzle 41. The nozzle-front bend 23c changes the flow direction of the processed liquid by approximately 90 degrees. In the wiring direction of the flow path of the nozzle-front bend 23c (horizontal in this example), a branch pipe 25 is provided, which constitutes a branch flow path branching from the unit supply piping 23. The branch pipe 25 is connected to the return piping 66. A branch flow meter 26 is installed in the branch pipe 25. The branch flow meter 26 measures the flow rate of the processed liquid flowing in the branch pipe 25. The ejection flow rate from the first nozzle 41 can be obtained by the difference between the supply flow rate measured by the supply flow meter 38 and the branch flow rate measured by the branch flow meter 26.

[0059] The processing fluid flowing in the unit supply piping 23 is guided to the first nozzle 41 through the horizontal section 23a, the nozzle pre-bend section 23c, and the downward section 23b, and sprayed out from the nozzle 41 onto the surface of the substrate W. A portion of the processing fluid flowing in the horizontal section 23a is guided from the nozzle pre-bend section 23c to the branch piping 25, and then to the return piping 66.

[0060] The processing liquid tank 21, common piping 24, tower supply piping 22, unit supply piping 23, and return piping 66 form a processing liquid flow path for processing liquid circulation. The common piping 24, tower supply piping 22, and unit supply piping 23 constitute a supply piping for supplying processing liquid from the processing liquid tank 21 to the substrate W.

[0061] The supply pipe bend 64 and the branch pipe 65 branching from there constitute the first particle separator 71. Furthermore, the nozzle inlet bend 23c and the branch pipe 25 branching from there constitute the second particle separator 72. The first particle separator 71 and the second particle separator 72 separate and capture the fine bubbles in the treatment liquid, thereby removing particles attached to the fine bubbles from the treatment liquid.

[0062] The particles to be removed include particles mixed into the liquid supplied from the liquid supply source 10. Also, the particles to be removed include particles mixed into the DIW supplied from the DIW supply source 13. Furthermore, the particles to be removed include particles originating from the flow path components constituting the flow path of the treatment fluid. Flow path components are components that are in contact with the treatment fluid, such as pipes, valves, and flow meters. Typically, at least the portion of the flow path components in contact with the treatment fluid is made of fluoropolymer. Sometimes, resin or additives such as plasticizers in the resin dissolve from the fluoropolymer-made flow path components and are observed as particles. Furthermore, the fluoropolymer-made flow path components capture or release foreign matter from the treatment fluid. Therefore, the flow path components are one source of particle generation.

[0063] Most of the particles observed on the surface of the substrate (especially semiconductor wafers) are organic matter; therefore, it is assumed that most of the particles present in the processing liquid are organic matter. Since organic particles are hydrophobic, they are more likely to adhere to air bubbles than water.

[0064] The bubble generator 31 is a device for generating microbubbles, such as a microbubble generator manufactured by Nihon Sangyo Co., Ltd.

[0065] Microbubbles are defined according to the International Organization for Standardization (ISO) 20480-1 and the Japanese Industrial Standard (JIS) B 8741-1. Microbubbles include ultrafine bubbles and microbubbles, but exclude millimeter and sub-millimeter bubbles. Ultrafine bubbles have a diameter of tens of nm to 1 μm. Microbubbles have a diameter of 1 μm to 100 μm. Millimeter / sub-millimeter bubbles have a diameter exceeding 100 μm.

[0066] The ultrafine bubbles in water are invisible to the naked eye, and water mixed with ultrafine bubbles is colorless and transparent. These ultrafine bubbles can remain in the water for weeks to months, and their viscosity is greater than their buoyancy. They undergo Brownian motion (microscopic motion) in the water while remaining in the water.

[0067] Microbubbles in water are visually perceptible, and water containing microbubbles appears cloudy. These microbubbles remain in the water for several minutes to tens of minutes. They rise very slowly (e.g., a 10 μm diameter bubble rises at approximately 3 mm / min). As they slowly rise, they dissolve into the water as gas dissolves. If the gas is not completely dissolved, the bubbles shrink in size, becoming ultrafine bubbles. Furthermore, multiple microbubbles can combine to form millimeter / submillimeter bubbles.

[0068] Microbubbles (ultrafine and microbubbles) in liquids move in the same manner as the surrounding liquid, exhibiting a different behavior than millimeter / submillimeter bubbles. Millimeter / submillimeter bubbles rise very rapidly in water (bubbles with a diameter of 1 mm rise at a speed of about 5 m / min to 6 m / min), and do not exhibit the same behavior as the surrounding liquid.

[0069] Microbubbles are negatively charged. Furthermore, like ordinary bubbles, they physically adsorb particles. Additionally, the energy released locally when a bubble disappears (luminescence, heat, shock waves, etc.) promotes the removal of adhering substances within the processing fluid flow path. This energy is greater for ultrafine bubbles than for microbubbles.

[0070] From a cleaning perspective, microbubbles clean by adsorbing and lifting dirt. While ultrafine bubbles also adsorb and remove dirt, they do not float in water, thus requiring the assistance of a liquid flow for effective cleaning. Because ultrafine bubbles are tiny bubbles smaller than 1 μm, they reduce the surface tension of the liquid, allowing them to penetrate into the gaps in the dirt and lift it to the surface for removal.

[0071] If both microbubbles and ultrafine bubbles are used, the ultrafine bubbles can remove dirt, while the microbubbles can make the dirt float to the surface.

[0072] In this embodiment, the bubble generator 31 produces microbubbles, including both ultrafine and microbubbles, which are then dispersed in the treatment liquid. The microbubbles can be generated using any method, such as a high-speed swirling flow or a Venturi flow. A gas inlet line 32, through which an inert gas such as nitrogen or air is introduced, is connected to the bubble generator 31. A gas valve 33 is installed on the gas inlet line 32. The gas valve 33 can be an on / off valve or a valve with an adjustable opening.

[0073] Although detailed illustrations are omitted in Figure 3, the cleaning fluid supply system 50 is substantially the same as the above-mentioned structure (medication fluid supply system) used to supply the cleaning fluid, except that no cleaning fluid is used, and has a structure that removes particles from the cleaning fluid, which is a type of treatment fluid.

[0074] Figure 4A is an enlarged schematic cross-sectional view showing the structure of the first particle separator 71, and Figure 4B is an enlarged schematic cross-sectional view showing the structure of the second particle separator 72.

[0075] When particle P is attached to microbubble F, it acts as a unified particle in the treatment liquid. The density of particle P attached to microbubble F is greater than that of water, and therefore, greater than the density of the treatment liquid. Consequently, when this particle passes through a tortuous flow path along with the laminar flow of the treatment liquid, it is unevenly distributed on the outer side of the tortuous flow path (away from the center of curvature) due to the greater centrifugal force (inertial force).

[0076] As shown in Figure 4A, the treatment liquid flowing upward through the upper supply pipe section 61 of the tower supply pipe 22 enters the supply pipe bend section 64 of the first particle separator 71 in a laminar flow state. The supply pipe bend section 64 changes the flow direction by approximately 180 degrees, allowing it to flow into the lower supply pipe section 62. In the supply pipe bend section 64, because the particles P attached to the microbubbles F receive centrifugal force more strongly than the treatment liquid, the distribution density in the outer region of the bend flow path of the supply pipe bend section 64 is greater than the distribution density in the central and inner regions.

[0077] Branch pipe 65 is connected to the outside of the supply pipe bend 64, extending from the tower supply pipe 22 in the direction of the bend in the supply pipe bend 64. In this way, most of the microbubbles F with particles P attached are guided to the branch pipe 65 and separated from the mainstream of the treatment liquid flowing towards the downward pipe section 62 and captured.

[0078] Because the bend in the supply pipe 64 forms an upward-protruding curved flow path, the properties of the microbubbles floating in the treated liquid can be utilized to collect the microbubbles and guide them towards the distribution pipe 65. The ultrafine bubbles with attached particles receive centrifugal force and are also affected by the upward movement of the microbubbles, thereby being guided to the outside (upper side) of the bend in the supply pipe 64. In this way, particles P in the treated liquid can be effectively separated and captured by the distribution pipe 65.

[0079] When the supply valve 36 is opened and the processing liquid is supplied to the substrate W, the processing liquid flows from the downward piping section 62 into the unit supply piping 23. As shown in Figure 4B, the processing liquid flows in a laminar state in the horizontal section 23a of the unit supply piping 23, enters the nozzle pre-bend section 23c, changes its flow direction by about 90 degrees, flows into the downward section 23b, and is sprayed downward from the first nozzle 41. The inertial force (centrifugal force) of the particles P attached to the microbubbles F in the nozzle pre-bend section 23c is greater than the inertial force (centrifugal force) of the same volume of processing liquid. Therefore, most of the microbubbles with attached particles do not enter the nozzle pre-bend section 23c, but flow into the branch pipe 25 extending horizontally in the wiring direction of the nozzle pre-bend section 23c. In this way, most of the microbubbles F with attached particles P are separated from and captured by the mainstream of the processing liquid heading towards the first nozzle 41.

[0080] In this way, the particles P in the treatment liquid adhere to the microbubbles F, and the microbubbles F are separated from the treatment liquid and captured, thereby allowing the treatment liquid with the particles P removed to be supplied to the substrate W from the first nozzle 41.

[0081] Figure 5 is a block diagram illustrating the electrical configuration of the main components of the substrate processing apparatus 1.

[0082] The control device 7 is equipped with a microcomputer and controls the controlled object equipped on the substrate processing device 1 according to a prescribed program. More specifically, the control device 7 includes a processor (CPU, Central Processing Unit) 7A and a memory 7B storing the program, configured to execute various controls for substrate processing by executing the program through the processor 7A.

[0083] Control device 7 controls the actions of the transfer robot IR, the central robot CR, the liquid valve 12, the DIW valve 15, the drain valve 18, the pump 30, the gas valve 33, the supply valve 36, the supply flow adjustment valve 37, the rotating chuck 40, and the valve 52. Furthermore, the control device 7 receives flow measurement signals from the supply flow meter 38 and the branch flow meter 26. Based on the flow values ​​measured by the supply flow meter 38 and the branch flow meter 26 respectively, the control device 7 controls the opening of the supply flow adjustment valve 37, thereby ensuring that the treated liquid is ejected from the first nozzle 41 at the target flow rate.

[0084] The control device 7 can also control the generation of microbubbles in the bubble generator 31. For example, the control device 7 can also control the generation of microbubbles in the bubble generator 31 by controlling the opening and closing or the opening degree of the gas valve 33 installed in the gas inlet line 32 of the bubble generator 31.

[0085] Figure 6 is a step diagram illustrating the particle removal method performed in the substrate processing apparatus 1. The multiple steps shown in Figure 6 are not necessarily performed in the order shown in Figure 6; typically, they are performed simultaneously in parallel. In this embodiment, the substrate processing apparatus 1 removes particles from the processing liquid while simultaneously supplying the processed liquid with the particles removed to the substrate W, thereby performing processing on the substrate W.

[0086] The particulate removal method includes step S1, in which the process liquid flows through the process liquid flow path. Specifically, step S1 is achieved by activating pump 30 using control device 7. Pump 30 draws process liquid from process liquid tank 21 and allows it to flow to common piping 24, tower supply piping 22, and unit supply piping 23. A portion of the process liquid also flows through branch piping 65, 25, and return piping 66.

[0087] The particle removal method further includes step S2 of supplying microbubbles to the processing liquid flowing in the processing liquid flow path. Specifically, microbubbles are supplied to the processing liquid by supplying the processing liquid from the common pipe 24 and the inert gas from the gas inlet line 32 to the bubble generator 31 disposed in the common pipe 24. In this embodiment, as described above, the microbubbles include microbubbles and ultrafine bubbles.

[0088] The particle removal method further includes step S3, which involves attaching particles in the treatment fluid flowing through the treatment fluid path to microbubbles. As mentioned above, most particles are organic matter and are therefore hydrophobic, thus adsorbing onto microbubbles and other air bubbles. This allows particles present in the treatment fluid to attach to other particles also present in the treatment fluid.

[0089] The particle removal method further includes step S4, which separates and captures the fine bubbles with attached particles from the processing liquid flowing through the processing liquid flow path. In this embodiment, this step is achieved by the action of a first particle separator 71 provided in the tower supply pipe 22 constituting the supply pipe, and a second particle separator 72 provided in the unit supply pipe 23, which also constitutes the supply pipe. By separating and capturing particles in the supply pipe, the processing liquid that has completed the particle separation and removal process is ejected from the first nozzle 41. In this way, a clean processing liquid with a smaller number of particles can be supplied to the substrate W.

[0090] The particle removal method further includes step S5, in which the treatment fluid guided to the branch pipes 65 and 25 (branch flow paths) in the first particle separator 71 and the second particle separator 72 is returned to the treatment fluid tank 21 via the return pipe 66. The treatment fluid containing a large number of microbubbles with attached particles is guided to the branch pipes 65 and 25, and this treatment fluid is returned to the treatment fluid tank 21.

[0091] The particulate removal method also includes step S6, which involves discarding the treatment solution in the treatment solution tank 21. When the treatment solution is stored in the treatment solution tank 21, the control device 7 keeps the drain valve 18 closed. Conversely, when discarding the treatment solution in the treatment solution tank 21, the control device 7 opens the drain valve 18. This allows the treatment solution in the treatment solution tank 21 to be discharged and discarded through the drain pipe 17. After the waste liquid is disposed of, the control device 7 closes the drain valve 18 and opens the chemical solution valve 12 and the DIW valve 15 to supply the chemical solution and DIW to the treatment solution tank 21, thus preparing a new treatment solution in the treatment solution tank 21. This process replaces the treatment solution.

[0092] It is preferable to replace the processing solution periodically. Specifically, the control device 7 determines when the processing solution replacement sequence (the lifespan of the processing solution) is due based on the usage time of the processing solution (e.g., the elapsed time since the processing solution was prepared) and the substrate processing volume (e.g., the number of substrates W processed or the batch number). If the processing solution replacement sequence is due, the control device 7 performs the processing solution replacement before the substrate W processing is completed. By performing the processing solution replacement at an appropriate time, excessive accumulation of particles in the processing solution can be avoided.

[0093] Thus, the particle removal method of this embodiment supplies microbubbles to the processing liquid, causing particles in the processing liquid to adhere to the microbubbles. The microbubbles with the attached particles are then separated and captured, thereby removing the particles from the processing liquid. Because the microbubbles persist in the processing liquid for a long time, they can cause more particles in the processing liquid to adhere to the microbubbles than conventional bubbles such as millimeter / submillimeter bubbles, thereby effectively removing particles from the processing liquid. Furthermore, the energy generated when the microbubbles disappear can promote the peeling off of foreign matter attached to the flow path forming components, and the special microbubbles can also penetrate into the gaps of dirt, causing the dirt to float and be removed. Therefore, it can remove foreign matter in the processing liquid flow path more effectively than conventional bubbles such as millimeter / submillimeter bubbles. In this way, a processing liquid with a higher degree of cleanliness can be supplied to the substrate W, thereby improving the substrate processing quality.

[0094] In this embodiment, the microbubbles include both ultrafine bubbles and millimeter bubbles. This allows foreign matter removed by the action of ultrafine bubbles to float to the surface via millimeter bubbles. Therefore, foreign matter (particles) can be effectively separated and removed by the first particle separator 71, which has a supply pipe bend 64 forming a particularly upward-protruding curved flow path.

[0095] Furthermore, since particles in the processing liquid can be removed by the first particle separator 71 and the second particle separator 72, there is no need for a filter to capture particles. This eliminates the need to replace filters, reducing downtime for maintenance of the substrate processing apparatus 1 and improving productivity. In addition, since there is no need for a particle removal circulation path through the particle capture filter within the housing 6, the piping configuration of the processing liquid supply device 3 can be simplified. Correspondingly, stagnant areas in the processing liquid can be reduced, thus reducing the leaching of foreign matter from the flow path components, and the adhesion and release of foreign matter onto the surfaces of the flow path components. Therefore, significant fluctuations in the amount of particles in the processing liquid can be suppressed when the flow state of the processing liquid changes (especially when the processing liquid begins to flow from a stopped state).

[0096] Furthermore, since the movement of microbubbles in the treatment liquid is different from that of ordinary bubbles such as millimeter bubbles / submillimeter bubbles, the swirling flow device described in Patent Document 1 is not suitable for separating microbubbles from the treatment liquid.

[0097] Figure 7 is a diagram illustrating the configuration of a substrate processing apparatus according to other embodiments of the present invention, showing other configuration examples of the processing liquid supply device 3. In Figure 7, the corresponding parts of each part shown in Figure 3 are labeled with the same reference numerals, and repeated descriptions are omitted where possible.

[0098] In this embodiment, the first particle separator 71 of the above embodiment is not provided. Instead, a third particle separator 73 is provided, which includes a spiral tube 80 and at least one (two in this embodiment) branch pipe 81 branching from the spiral tube 80.

[0099] The spiral tube 80 is a piping with a spiral flow path. The spiral tube 80 is installed in the tower supply piping 22, forming part of the supply piping. The spiral tube 80 is an example of a supply piping bend provided in the supply piping.

[0100] The branch pipe 81 is connected to the helical tube 80 in a branching manner from the helical flow path of the helical tube 80 in the wiring direction. In this embodiment, the central axis of the helical shape of the helical tube 80, namely the helical shaft 80a, faces laterally (more specifically, horizontally). Therefore, the helical tube 80 has a plurality of upwardly protruding curved portions 80b with intervals along the helical shaft 80a. One end of the branch pipe 81 is connected to one of these upwardly protruding curved portions 80b in the wiring direction. The other end of the branch pipe 81 is connected to the return pipe 66.

[0101] The other components and actions are the same as those in Figure 3.

[0102] With this configuration, the same function and effect as the embodiment shown in Figure 3 can be achieved, and the particle removal method shown in Figure 6 can be performed. Furthermore, the spiral tube 80 provides multiple bends in the piping, allowing particles to be separated at multiple points as needed. This effectively separates particles from the treatment liquid.

[0103] Figure 8 is a diagram illustrating the configuration of a substrate processing apparatus according to further embodiments of the present invention, showing further configuration examples of the processing liquid supply device 3. In Figure 8, corresponding parts of each part shown in Figure 3 are labeled with the same reference numerals, and repeated descriptions are omitted where possible.

[0104] In this embodiment, the first particle separator 71 and the second particle separator 72 are not provided. Instead, a fourth particle separator 74 and a fifth particle separator 75 are provided to apply an electric field (especially a DC electric field) to the processed liquid flowing in the processed liquid flow path, thereby changing the trajectory of the microbubbles in the processed liquid. In the configuration example of Figure 8, the fourth particle separator 74 is disposed in the tower supply piping 22, and the fifth particle separator 75 is disposed in the supply piping 23 of each unit.

[0105] The fourth particle separator 74 includes a first electrode E1 disposed in a portion of the supply piping, namely the tower supply piping 22, a branch pipe 83 forming a branch flow path from the tower supply piping 22, and a second electrode E2 disposed in the branch pipe 83.

[0106] The first electrode E1 is positioned near the connection point 83a between the branch pipe 83 and the tower supply pipe 22. The first electrode E1 has the same polarity as the charged electrode (negative) of the microbubbles, and in this embodiment, it is the negative electrode. Correspondingly, the second electrode E2 has the opposite polarity to the charged electrode of the microbubbles, and in this embodiment, it is the positive electrode. Therefore, the first electrode E1 exerts a repulsive force (Coulomb force) on the microbubbles, and the second electrode E2 exerts an attractive force (Coulomb force) on the microbubbles. Consequently, the processed liquid flowing in the tower supply pipe 22 is subjected to a Coulomb force towards the branch pipe 83 near the first electrode E1, causing its trajectory to change and guiding it towards the branch pipe 83. The branch pipe 83 is connected to the return pipe 66.

[0107] Similarly, the fifth particle separator 75 includes a first electrode E11 disposed in a portion of the supply piping, namely the unit supply piping 23, a branch pipe 84 forming a branch flow path from the unit supply piping 23, and a second electrode E12 disposed in the branch pipe 84. The first electrode E11 is disposed near the connection position of the branch pipe 84 to the unit supply piping 23, namely the branch position 84a.

[0108] The first electrode E11 is an electrode with the same polarity as the charged electrode (negative) of the microbubble, and in this embodiment, it is the negative electrode. Correspondingly, the second electrode E12 is an electrode with the opposite polarity to the charged electrode of the microbubble, and in this embodiment, it is the positive electrode. Therefore, the first electrode E11 exerts a repulsive force (Coulomb force) on the microbubble, and the second electrode E12 exerts an attractive force (Coulomb force) on the microbubble. As a result, the processing liquid flowing in the unit supply pipe 23 is subjected to a Coulomb force towards the branch pipe 84 near the first electrode E11, causing its trajectory to change and guiding it towards the branch pipe 84. The branch pipe 84 is connected to the return pipe 66. In the example of FIG. 8, the second electrode E12 is disposed at the connection position 84b with the return pipe 66, which can also be said to be disposed on the return pipe 66.

[0109] Thus, in this embodiment, the fourth particle separator 74 separates and collects the processing liquid flowing from the tower supply pipe 22, which is coated with fine air bubbles. Furthermore, in each of the plurality of unit supply pipes 23 branching from the tower supply pipe 22, the processing liquid flowing from the unit supply pipe 23, which is coated with fine air bubbles, is separated and collected directly in front of the first nozzle 41. This allows for the supply of a cleaner processing liquid with fewer particles to the substrate W from the first nozzle 41.

[0110] With the configuration of this embodiment, the particle removal method shown in FIG6 can also be performed. In this embodiment, the trapping step S4 applies an electric field (DC electric field) to the processing liquid flowing in the processing liquid flow path, causing the trajectory of the microbubbles in the processing liquid to change, guiding the microbubbles to the branch pipes 83 and 84 that form the branch flow path from the processing liquid flow path and separating them.

[0111] Alternatively, the second electrodes E2 and E12, which are located near the distribution tubes 83 and 84, can be omitted (or located in other positions), and the repulsive force (Coulomb force) of the first electrodes E1 and E11 can be used to change the trajectory of the microbubbles in the treatment solution and guide them to the distribution tubes 83 and 84.

[0112] Figure 9 is a diagram illustrating the configuration of a substrate processing apparatus according to further embodiments of the present invention, showing further configuration examples of the processing liquid supply device 3. In Figure 9, corresponding parts of each part shown in Figure 3 are labeled with the same reference numerals, and repeated descriptions are omitted where possible.

[0113] In this embodiment, the first particle separator 71 and the second particle separator 72 are not provided. Instead, a sixth particle separator 76 is provided, which includes: a filter 85 that filters the processing liquid flowing in the processing liquid flow path and captures microbubbles in the processing liquid; and a branch pipe 86 that forms a branch flow path to guide the microbubbles captured by the filter 85.

[0114] The sixth particle separator 76 is installed in the supply pipe 23 of each unit and captures microbubbles in the supply pipe near the first nozzle 41.

[0115] As shown in the enlarged schematic cross-sectional view in Figure 10, the filter 85 has a filter membrane 91 through which the treated liquid passes, and a housing 92 that supports the filter membrane 91 inside. The housing 92 has an inlet 93 for introducing the treated liquid from the upstream unit supply pipe 23, and an outlet 94 for discharging the treated liquid from the downstream unit supply pipe 23. The space inside the housing 92 has: an upstream chamber, namely a capture chamber 92A, which is connected to the inlet 93 via the filter membrane 91; and a downstream chamber, namely a through chamber 92B, which guides the treated liquid passing through the filter membrane 91; the through chamber 92B is connected to the outlet 94.

[0116] The filter membrane 91 has multiple pores with a pore size defined to prevent microbubbles F from passing through. Here, microbubbles F in the treated liquid are intercepted by the filter membrane 91 and captured in the capture chamber 92A. The treated liquid passes through the filter membrane 91 to the pass chamber 92B and is guided from the outlet 94 to the downstream unit supply pipe 23. The pore size of the filter membrane 91 is larger than the size of the particle P but smaller than the size of the microbubble F. Therefore, having a pore size larger than that of the captured particle P prevents clogging problems caused by the capture of particle P.

[0117] One end of the distribution pipe 86 is connected to the capture chamber 92A. The other end of the distribution pipe 86 is connected to the return pipe 66. A portion of the processing liquid flows from the capture chamber 92A to the distribution pipe 86. Through the flow of the processing liquid, the microbubbles F captured in the capture chamber 92A are guided to the distribution pipe 86. In this way, the microbubbles F with particles P attached separate from the processing liquid and are captured in the distribution pipe 86. In this way, a cleaner processing liquid with fewer particles P can be supplied to the substrate W from the first nozzle 41.

[0118] With the configuration of this embodiment, the particle removal method shown in FIG6 can also be performed. In this embodiment, the capture step S4 filters the treatment liquid by means of a filter 85 disposed in the middle of the treatment liquid flow path, thereby capturing micro bubbles, and guides the micro bubbles captured by the filter 85 to the branch pipe 86 that forms a branch flow path from the branch of the treatment liquid flow path.

[0119] Alternatively, the filter 85 can be configured to be placed in the tower supply piping 22 to capture microbubbles before branching into multiple unit supply piping 23. In this case, the number of filters 85 can be reduced, simplifying the configuration and reducing costs. However, in order to capture as much foreign matter as possible flowing out of the self-flow path components, and to supply the substrate W with a high degree of cleanliness of the processing liquid, it is preferable to place the filter 85 as close as possible to the spray outlet of the first nozzle 41.

[0120] Figure 11 is a diagram illustrating the configuration of a substrate processing apparatus according to further embodiments of the present invention, showing further configuration examples of the processing liquid supply device 3. In Figure 11, the corresponding parts of each part shown in Figure 7 are labeled with the same reference numerals, and repeated descriptions are omitted where possible.

[0121] In this embodiment, a seventh particle separator 77 is installed in one example of the processing fluid flow path, namely the return pipe 66. In this example, the return pipe 66 has a horizontally extending horizontal portion 66a and a downward portion 66b that flows down into the processing fluid tank 21. An arc-shaped bend 66c is formed in the horizontal portion 66a and the downward portion 66b. A branch pipe 88, forming a branch flow path extending from the bend 66c in the wiring direction of the curved flow path, is connected to the bend 66c. The bend 66c and the branch pipe 88 constitute the seventh particle separator 77.

[0122] The seventh particle separator 77 separates and captures microbubbles from the processing liquid flowing in the return pipe 66, thereby removing particles attached to the microbubbles. The function of separating microbubbles from the processing liquid is the same as that of the first particle separator 71 and the second particle separator 72 described with reference to Figures 4A and 4B, utilizing the centrifugal force (inertial force) acting on the microbubbles with attached particles.

[0123] A small amount of treated fluid, guided along with the microbubbles, to the branch pipe 88 is discarded. For example, the branch pipe 88 is connected to the drain pipe 17 downstream of the drain valve 18, allowing the small amount of treated fluid guided to the branch pipe 88 to be discarded through the drain pipe 17. A flow control valve 89 can also be installed in the branch pipe 88. By appropriately setting the opening of the flow control valve 89, the flow rate of the treated fluid discarded through the branch pipe 88 can be limited, thus preventing the discarding of large amounts of treated fluid. The flow control valve 89 can be a manual valve or a valve whose opening can be controlled by the control device 7 (e.g., a motor needle valve).

[0124] According to the configuration of this embodiment, the same function and effect as the embodiment of FIG7 can be achieved, and the particle removal method shown in FIG6 can be performed. In this case, the capture step S4 includes the following steps: using the 7th particle separator 77, the microbubbles with particles attached are separated and captured from the processing liquid flowing in the return pipe 66, and guided to the branch pipe 88 and the drain pipe 17 that constitute the waste flow path and then discarded.

[0125] Furthermore, when performing the particle removal method according to this embodiment, in the trapping step S4, at multiple locations in the processing liquid flow path, fine bubbles with attached particles are separated from the processing liquid flowing in the processing liquid flow path and guided to branch pipes 25, 81, 88 that constitute multiple branch flow paths branching from the multiple locations. A portion of the processing liquid is guided along with the fine bubbles to each branch pipe 25, 81, 88. In the return step S4, the processing liquid guided to at least one of the multiple branch pipes 25, 81, 88 is returned to the processing liquid tank 21. Furthermore, in the discarding step S6, the processing liquid guided to at least one of the multiple branch pipes 25, 81, 88 is discarded before returning to the processing liquid tank 21.

[0126] Applying the configuration of this embodiment to the embodiment shown in FIG3, a seventh particle separator 77 can also be installed in the return piping 66, for example, at the position indicated by the two-point chain line in FIG3. In the embodiments shown in FIG8 and FIG9, a seventh particle separator 77 can also be installed in the return piping 66, for example, at the position indicated by the two-point chain line in each figure.

[0127] As for the configuration of the 7th particle separator 77, instead of using the bend in the piping shown in FIG11, it can use the same spiral tube configuration as the 3rd particle separator 73, the same electric field configuration as the 4th particle separator 74 (see FIG8), and the same filter configuration as the 6th particle separator 76 (see FIG10).

[0128] Figure 12 is a diagram illustrating the configuration of a substrate processing apparatus according to further embodiments of the present invention, showing further configuration examples of the processing liquid supply device 3. In Figure 12, the corresponding parts of each part shown in Figure 7 are labeled with the same reference numerals, and repeated descriptions are omitted where possible.

[0129] In this embodiment, an overflow drain pipe 97 is connected to the treatment liquid tank 21. A drain valve 98 is installed in the overflow drain pipe 97. Furthermore, an on / off valve 27 is installed in the common pipe 24 downstream of the pump 30. With this configuration, a portion of the treatment liquid stored in the treatment liquid tank 21 near the liquid surface can be guided to the overflow drain pipe 97 for drainage.

[0130] Specifically, control device 7 closes the on / off valve 27, opens the drain valve 98, and then opens the chemical solution valve 12 and the DIW valve 15. This stops the outflow of the treatment fluid from the treatment fluid tank 21, while simultaneously supplying fresh fluid from the chemical solution supply pipe 11 and the DIW supply pipe 14. As a result, the fluid level in the treatment fluid tank 21 rises. If the fluid level reaches the inlet of the overflow drain pipe 97, the portion of the treatment fluid stored near the surface of the treatment fluid in the treatment fluid tank 21 can be drained through the overflow drain pipe 97.

[0131] Because the microbubbles contained within the microbubbles float in the treatment liquid, the ultrafine bubbles also rise along with the upward flow of the microbubbles. Furthermore, there are also cases where multiple microbubbles combine to form millimeter / submillimeter bubbles, which also create an upward flow in the treatment liquid. In this way, the microbubbles with attached particles gather near the surface of the treatment liquid stored in the treatment liquid tank 21 and can be removed from the treatment liquid supply path along with a small amount of treatment liquid through the overflow drain pipe 97.

[0132] When the particle removal method of FIG6 is performed by means of this embodiment, the waste liquid step S6 includes the step of discarding a portion of the treatment liquid stored in the treatment liquid tank 21 near the liquid surface.

[0133] The configuration of this embodiment can also be combined with the configurations of the embodiments shown in Figures 3, 8, 9 and 11.

[0134] Figure 13 is a diagram illustrating the configuration of a substrate processing apparatus according to further embodiments of the present invention, showing further configuration examples of the processing liquid supply device 3. In Figure 11, the corresponding parts of each part shown in Figure 7 are labeled with the same reference numerals, and repeated descriptions are omitted where possible.

[0135] In this embodiment, the return piping 66 is omitted. Furthermore, a small amount of treatment fluid, guided along with the microbubbles to the branch pipes 25 and 81 forming branch flow paths, is discarded. If the pump 30 is operated only when the supply valve 36 is opened, the treatment fluid in the tower supply piping 22 and the unit supply piping 23 does not flow when treatment fluid is not supplied to the substrate W. Therefore, the amount of treatment fluid guided to the branch pipes 25 and 81 and discarded is not large.

[0136] This embodiment also allows for the particle removal method shown in Figure 6. However, the return step S5 is not performed. Furthermore, since the treatment liquid containing microbubbles with attached particles is not returned to the treatment liquid tank 21, it is not necessary to replace / discard the treatment liquid stored in the treatment liquid tank 21. Therefore, the disposal step S6 can also be omitted.

[0137] The configuration of this embodiment can also be applied to the configurations of the embodiments shown in Figures 3, 8, 9 and 11.

[0138] The present invention has been described above in terms of its embodiments, but it may also be implemented in other forms.

[0139] For example, in the above embodiment, a bubble generator 31 is provided in the common piping 24, but a bubble generator can also be provided in other locations. For example, bubble generators can also be provided in the drug supply piping 11 and the DIW supply piping 14 respectively, supplying the drug solution containing microbubbles and the DIW containing microbubbles to the treatment liquid tank 21, diluting the drug solution to an appropriate concentration, and preparing a treatment liquid containing microbubbles in the treatment liquid tank 21.

[0140] Furthermore, the above embodiment shows an example of using a bubble generator 31 that generates both microbubbles and ultrafine bubbles, but two bubble generators that generate microbubbles and ultrafine bubbles respectively can also be used. In this case, it is preferable that the two bubble generators are connected in parallel to the processing liquid flow path, and the processing liquid from the two bubble generators is combined and supplied to the processing tower 2.

[0141] Furthermore, in the above embodiments, examples have been described in which the microbubbles mixed in the treatment liquid include both microbubbles and ultrafine bubbles, but the microbubbles mixed in the treatment liquid may also include only one of them.

[0142] Furthermore, the above embodiment shows an example of processing substrate W with a single-chip processing unit 20, but the present invention can also be applied to a batch substrate processing apparatus that processes multiple substrates at the same time.

[0143] Furthermore, various design changes may be implemented within the scope of the matters described in the patent application.

[0144] 1: Substrate processing device 2: Processing Tower 2A: First processing tower, processing tower 2B: Second processing tower, processing tower 2C: Third processing tower, processing tower 2D: 4th processing tower, processing tower 3: Processing fluid supply device 4A: Fluid Unit 4B: Fluid Unit 4C: Fluid Unit 4D: Fluid Unit 5:Conveyance Road 6: Housing 7: Control device 7A: Processor 7B: Memory 10: Drug supply source 11: Drug supply piping 12: Medicine Dispensing Valve 13: DIW Supply Source 14: DIW supply piping 15: DIW valve 17: Drainage piping 18: Drain valve 20: Processing Unit 21: Processing liquid tank 22: Tower supply piping 22A: Tower supply piping 22B: Tower supply piping 22C: Tower supply piping 22D: Tower supply piping 23: Unit supply piping 23a: Horizontal section 23b: Downlink 23c: Front bend of the nozzle 24: Common piping 25: Sub-distribution management 26: Branch Flow Meter 27: On / off valve 30: Pump 31: Bubble Generator 32: Gas introduction line 33: Gas valve 36: Supply valve 37: Supply flow regulating valve 38: Supply Flow Meter 40: Rotating clamp 41: Nozzle 1 42: Nozzle 2 43: Cup 44: Processing Chamber 50: Cleaning fluid supply system 51:Piping 52: Valve 60: Upstream Piping Department 61: Upstream Piping Section 62: Downstream Piping Section 63: Relay Piping Department 64: Supply piping bend 65: Sub-control 66: Return to piping 66a: Horizontal section 66b: Downlink 66c: Bending part 71: First Particle Separator 72: Second particle separator 73: Third Particle Separator 74: Fourth Particle Separator 75: Fifth Particle Separator 76: 6th Particle Separator 77: 7th Particle Separator 80: Spiral tube 80a: Helical shaft 80b: Curved section 81: Sub-distribution management 83: Sub-distribution management 83a: Branch position 84: Sub-distribution management 84a: Branch position 84b: Connection location 85: Filter 86: Sub-control 88: Sub-control 89: Flow regulating valve 91: Filter membrane 92: Outer shell 92A: Capture Chamber 92B: Through Room 93: Entrance 94: Exports 97: Overflow drainage piping 98: Drain valve A1: Axis of rotation C: Carrier CR: Central Robot E1: First electrode E2: Second electrode E11: Electrode 1 E12: Second electrode F: Microbubbles IR: Transport Robot LP: Loading Port P: Particles R: Processing fluid supply source S1~S6: Steps W: substrate X: Extension direction

Claims

1. A particle removal method, comprising the steps of: circulating a processing liquid in a processing liquid flow path; supplying microbubbles to the processing liquid flowing in the processing liquid flow path; causing particles in the processing liquid flowing in the processing liquid flow path to adhere to the microbubbles within the processing liquid flow path; and separating and collecting the microbubbles with the particles attached from the processing liquid flowing in the processing liquid flow path; wherein the collecting step involves separating the microbubbles with the particles attached from the processing liquid flowing in the processing liquid flow path at a plurality of locations in the processing liquid flow path, and guiding them to a plurality of branch flow paths branching from the plurality of locations respectively. A portion of the aforementioned processing liquid is guided along with the aforementioned microbubbles to each branch flow path; and the particle removal method further includes the following steps: returning the aforementioned processing liquid that has been guided to at least one of the aforementioned plurality of branch flow paths to the processing liquid tank where the aforementioned processing liquid is stored; and discarding the aforementioned processing liquid that has been guided to at least one of the aforementioned plurality of branch flow paths, preventing it from returning to the aforementioned processing liquid tank.

2. The particle removal method of claim 1, wherein the processing fluid flow path includes a pipe having a bend; the trapping step traps the fine bubbles that are guided in the tangential direction of the bend from the branch flow path branching off from the pipe.

3. The particle removal method of claim 2, wherein the piping includes a supply piping that supplies processing liquid from a processing liquid tank storing the processing liquid to the substrate; the bend includes a supply piping bend disposed in the supply piping.

4. The particle removal method of claim 3, wherein the supply pipe is connected to a nozzle that sprays the treatment liquid onto the substrate; the bend in the supply pipe includes a nozzle front bend disposed directly in front of the nozzle.

5. The particle removal method of claim 4, wherein the nozzle is disposed in a processing chamber that divides the processing space for processing the substrate; and the forward curved portion of the nozzle is disposed in the processing chamber.

6. The particle removal method of claim 2, wherein the aforementioned curved portion includes a spiral tube disposed in the aforementioned piping.

7. The particle removal method of claim 2, wherein the curved portion includes an upwardly protruding curved portion.

8. The particle removal method of claim 1, wherein the trapping step involves applying an electric field to the processing liquid flowing in the processing liquid flow path, thereby changing the trajectory of the microbubbles in the processing liquid, guiding the microbubbles to the branch flow path branching off from the processing liquid flow path and separating them.

9. The particle removal method of claim 1, wherein the above-mentioned trapping step is to filter the processing liquid using a filter disposed in the middle of the processing liquid flow path, thereby capturing the fine bubbles, and guiding the fine bubbles captured by the filter to the branch flow path branching off from the processing liquid flow path.

10. The particulate removal method of any one of claims 1 to 9, wherein the processing fluid flow path includes a return pipe that returns the processing fluid to the processing fluid tank; and the return step involves returning the processing fluid that has been directed to at least one of the plurality of branch flow paths to the processing fluid tank via the return pipe.

11. The particle removal method of claim 10, wherein at least one of the plurality of branch flow paths originates from the aforementioned return piping branch; and the aforementioned waste disposal step comprises the following steps: separating and capturing the microbubbles with the aforementioned particles adhering to the processing liquid flowing from the aforementioned return piping, and guiding them to a waste flow path formed by the branch flow path originating from the aforementioned return piping branch for disposal.

12. The particulate removal method of any one of claims 1 to 9 further includes the step of discarding the aforementioned treatment liquid in the aforementioned treatment liquid tank.

13. The particulate removal method of claim 12, wherein the waste liquid step discards a portion of the treatment liquid stored in the treatment liquid tank near the liquid surface.

14. The particle removal method of any one of claims 1 to 9, wherein the aforementioned microbubbles include microbubbles and ultrafine bubbles.

15. A substrate processing apparatus comprising: a nozzle for supplying a processing liquid to a substrate; a processing liquid flow path through which the processing liquid flows; a bubble generator for supplying microbubbles to the processing liquid flowing in the processing liquid flow path; and a plurality of particle separators, which separate particles attached to the microbubbles by separating and capturing the microbubbles from the processing liquid flowing in the processing liquid flow path; wherein the plurality of particle separators are located at a plurality of positions in the processing liquid flow path to separate the microbubbles with the particles attached from the processing liquid flowing in the processing liquid flow path, and guide them to a plurality of branch flow paths branching from the plurality of positions respectively; A portion of the aforementioned processing liquid is guided along with the aforementioned microbubbles to each branch flow path; and the substrate processing apparatus further includes a return pipe that returns the aforementioned processing liquid, which has been guided to at least one of the aforementioned plurality of branch flow paths, to the processing liquid tank where the aforementioned processing liquid is stored; and at least one of the aforementioned plurality of branch flow paths constitutes a waste flow path, which discards the aforementioned processing liquid that has been guided to the branch flow path and prevents it from returning to the aforementioned processing liquid tank.

16. The substrate processing apparatus of claim 15, wherein at least one of the plurality of particle separators includes a bend in the piping constituting the processing fluid flow path; and the branch flow path branches off from the piping in the tangential direction of the bend.

17. The substrate processing apparatus of claim 16, wherein the bending portion includes a spiral tube disposed on the piping.

18. The substrate processing apparatus of claim 15, wherein at least one of the plurality of particle separators includes an electrode that imparts an electric field to the processing liquid flowing in the processing liquid flow path; and microbubbles that are tracked by the change of the electric field are guided to the branch flow path.

19. The substrate processing apparatus of claim 15, wherein at least one of the plurality of particle separators includes a filter disposed in the middle of the processing flow path for filtering the processing liquid and capturing the microbubbles; and the microbubbles captured by the filter are guided to the branch flow path.

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