Substrate processing apparatus and substrate processing method

Abstract

To provide a substrate processing apparatus and a substrate processing method that can reduce the frequency of filter replacement.SOLUTION: A substrate processing apparatus 1 includes a substrate processing portion 2, a processing liquid supply path 10 that supplies a processing liquid to the substrate processing portion, a branch path 12 that branches from a branch point 11 on the processing liquid supply path, a DC electric field cabinet 20 provided on the branch path, a return path 16 that supplies the processing liquid from the DC electric field cabinet to a junction 15 on the processing liquid supply path, a filter 31 provided on the processing liquid supply path, a contamination measurement portion 14 that measures the contamination level of the processing liquid upstream of the branch point, a flow path switching portion 13 that directs the processing liquid to either the processing liquid supply path downstream of the branch point or the branch path, and a controller 50 that controls the flow path switching portion on the basis of the contamination level measured by the contamination measurement portion. The DC electric field cabinet stores the processing liquid and applies a DC electric field to the stored processing liquid to precipitate and remove contaminants in the processing liquid.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus and method for processing substrates, including, for example, semiconductor wafers, substrates for FPDs (Flat Panel Displays) such as liquid crystal displays and organic EL (electroluminescence) displays, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells. [Background technology]

[0002] If foreign matter (particles) is mixed in the processing liquid supplied to the substrate, the substrate processing will be defective. Therefore, a filter that captures foreign matter is installed in the processing liquid supply path that supplies the processing liquid to the substrate (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-36639 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-128777 [Non-patent literature]

[0004] [Non-Patent Document 1] Junichiro Tsubaki and Takamasa Mori, "Development of Chemical-Free Coagulation Technology for Liquid-Submerged Particles Using Electric Fields," Nagoya Institute of Scientific and Industrial Research, Research Department, Annual Research Report (2013 edition) Summary of the Invention [Problem to be solved by the invention]

[0005] When the filter reaches its service life due to the accumulation of trapped particles, it must be replaced. Specifically, maintenance work to replace the filter is performed when the filter's service life reaches a threshold value or when the number of particles observed on processed substrates reaches a threshold value. Of course, the less frequently such maintenance work is performed, the better, as it can shorten the period of interruption of substrate processing and contribute to improving productivity.

[0006] However, the more contaminated the processing liquid, the more frequently the filter needs to be replaced. In particular, when processing liquids used in substrate processing are recovered and reused to reduce the consumption of processing liquids (especially chemical liquids), the recovered processing liquids are highly contaminated. Therefore, while the consumption of processing liquids can be reduced, the frequency of maintenance for filter replacement increases.

[0007] Therefore, one embodiment of the present invention provides a substrate processing apparatus and a substrate processing method that can reduce the frequency of filter replacement. [Means for solving the problem]

[0008] An embodiment of the present invention provides a substrate processing apparatus and a substrate processing method having the following exemplary features.

[0009] 1. A substrate processing unit that supplies a processing liquid to a substrate to process the substrate; a processing liquid supply path for supplying the processing liquid to the substrate processing unit; a branch path branching from a branch point on the processing liquid supply path; a DC electric field cabinet provided in the branch path, which stores the treatment liquid and applies a DC electric field to the stored treatment liquid to precipitate and remove contaminants in the treatment liquid; a return path that joins the processing solution supply path at a joining point on the processing solution supply path and supplies the processing solution from the DC electric field cabinet to the joining point; a filter provided in the treatment liquid supply path downstream of the branch point and the confluence point to remove foreign matter from the treatment liquid; a contamination measuring unit that is provided in the processing liquid supply path upstream of the branch point and that measures a contamination level of the processing liquid passing through the processing liquid supply path; a flow path switching unit that guides the treatment liquid flowing from upstream of the branch point toward the branch point to either the treatment liquid supply path downstream of the branch point or the branch path; a controller that controls the flow path switching unit based on the degree of contamination measured by the contamination measuring unit.

[0010] 2. The substrate processing apparatus according to item 1, wherein the confluence is disposed on the processing liquid supply path upstream of the contamination measurement unit.

[0011] 3. The substrate processing apparatus according to item 1, wherein the junction is disposed on the processing liquid supply path between the branch point and the filter.

[0012] 4. A substrate processing apparatus according to any one of items 1 to 3, further comprising a recovery path connected to the processing liquid supply path upstream of the contamination measurement section, for recovering the processing liquid used for processing the substrate from the substrate processing section and guiding it to the processing liquid supply path.

[0013] 5. The substrate processing apparatus according to any one of items 1 to 4, further comprising a processing liquid cabinet provided in the processing liquid supply path downstream of the branch point and the confluence point and upstream of the filter, for storing the processing liquid.

[0014] 6. A processing liquid valve interposed in the processing liquid supply path between the filter and the substrate processing section; Item 6. The substrate processing apparatus according to item 5, further comprising a circulation path that branches off from a circulation branch point located on the processing liquid supply path between the processing liquid valve and the filter, and returns the processing liquid to the processing liquid cabinet for circulation.

[0015] 7. A plurality of the DC electric field cabinets are included; 7. The substrate processing apparatus according to any one of items 1 to 6, further comprising an input cabinet selector that introduces the processing liquid introduced into the branch path at the branch point into one of the plurality of DC electric field cabinets.

[0016] 8. The substrate processing apparatus according to item 7, further comprising a return cabinet selector that directs the processing liquid that has been processed in one of the plurality of DC electric field cabinets to the return path.

[0017] 9. The substrate processing apparatus described in item 8, wherein the controller controls the input cabinet selector and the return cabinet selector so that another DC electric field cabinet is selected by the input cabinet selector and the return cabinet selector, respectively.

[0018] 10. The DC electric field cabinets have electrodes with different areas in contact with the treatment liquid, 10. The substrate processing apparatus according to any one of items 7 to 9, wherein the controller controls the loading cabinet selector based on the degree of contamination measured by the contamination measuring unit.

[0019] 11. The DC electric field cabinets have different DC electric field intensities applied to the treatment liquid; Item 11. The substrate processing apparatus according to any one of items 7 to 10, wherein the controller controls the loading cabinet selector based on the degree of contamination measured by the contamination measuring unit.

[0020] 12. The multiple DC electric field cabinets are connected in series so that the treatment liquid treated by one DC electric field cabinet is input into another DC electric field cabinet; 12. The substrate processing apparatus according to any one of items 7 to 11, wherein the controller controls the loading cabinet selector based on the degree of contamination measured by the contamination measuring unit.

[0021] 13. A substrate processing apparatus described in any one of items 1 to 12, wherein the controller controls the strength of the DC electric field applied to the processing liquid by the DC electric field cabinet based on information on the type of the processing liquid, information on the type of foreign matter in the processing liquid, or the degree of contamination measured by the contamination measurement unit.

[0022] 14. The DC electric field cabinet includes a plurality of electrodes for applying a DC electric field in the treatment liquid, and a DC power supply for applying a DC voltage to the plurality of electrodes; Item 14. The substrate processing apparatus according to any one of items 1 to 13, wherein the controller controls the DC voltage applied to the plurality of electrodes from the DC power source based on information on the type of the processing liquid, information on the type of foreign matter in the processing liquid, or the degree of contamination measured by the contamination measurement unit.

[0023] 15. The DC electric field cabinet includes a plurality of electrodes for applying a DC electric field to the treatment liquid, and an electrode arrangement changing unit for changing the arrangement of the plurality of electrodes; 15. The substrate processing apparatus according to any one of items 1 to 14, wherein the controller controls the electrode arrangement changing unit based on information on the type of the processing liquid, information on the type of foreign matter in the processing liquid, or the degree of contamination measured by the contamination measuring unit.

[0024] 16. The substrate processing apparatus according to item 15, wherein the electrode arrangement change unit changes the spacing between the plurality of electrodes.

[0025] 17. The substrate processing apparatus according to item 15 or 16, wherein the electrode arrangement changing unit changes the arrangement of the plurality of electrodes so that the area of ​​the immersed portion of the plurality of electrodes immersed in the processing liquid changes.

[0026] 18. The substrate processing apparatus according to any one of items 1 to 17, wherein the DC electric field cabinet includes an electrode whose surface is coated with a resin.

[0027] 19. A measuring step of measuring the contamination level of the processing liquid passing through a processing liquid supply path that supplies the processing liquid to a substrate processing section; a flow path switching step of guiding the processing liquid to either a branch path branching from a branch point on the processing liquid supply path or the processing liquid supply path downstream of the branch point, depending on the measured contamination level; a purification step of introducing the treatment liquid introduced into the branch path into a DC electric field cabinet, and applying a DC electric field to the treatment liquid in the DC electric field cabinet to precipitate and remove contaminants in the treatment liquid, thereby purifying the treatment liquid; a processing liquid returning step of returning the processing liquid purified in the DC electric field cabinet to the processing liquid supply path at a junction on the processing liquid supply path; a filtering step of removing foreign matter from the processing liquid by a filter provided in the processing liquid supply path downstream of the branch point and the junction point.

[0028] 20. A substrate processing method according to item 19, wherein the confluence is disposed upstream of a measurement point on the processing liquid supply path where the contamination level is measured.

[0029] 21. A substrate processing method according to item 19, wherein the confluence point is disposed on the processing liquid supply path between the branch point and the filter.

[0030] 22. A substrate processing method described in any one of items 19 to 21, further comprising a processing liquid recovery step of recovering the used processing liquid used for processing the substrate in the substrate processing unit and guiding it to the processing liquid supply path upstream of a measurement point on the processing liquid supply path where the contamination level is measured.

[0031] 23. A plurality of said DC electric field cabinets are provided; 23. The substrate processing method according to any one of items 19 to 22, further comprising an input cabinet selection step of guiding and inputting the processing liquid introduced into the branch path at the branch point into one of the plurality of DC electric field cabinets.

[0032] 24. The substrate processing method according to item 23, further comprising a return cabinet selection step of guiding the processing liquid processed in any of the plurality of DC electric field cabinets to the processing liquid supply path.

[0033] 25. A substrate processing method according to item 24, wherein another DC electric field cabinet is selected by the input cabinet selection step and the return cabinet selection step, respectively.

[0034] 26. The DC electric field cabinets have electrodes with different areas in contact with the treatment liquid; 26. The substrate processing method according to any one of items 23 to 25, wherein the input cabinet selection step selects one of the DC electric field cabinets based on the contamination level measured in the measurement step.

[0035] 27. The DC electric field cabinets have different DC electric field intensities applied to the treatment liquid; 27. The substrate processing method according to any one of items 23 to 26, wherein the input cabinet selection step selects one of the DC electric field cabinets based on the contamination level measured in the measurement step.

[0036] 28. The multiple DC electric field cabinets are connected in series so that the treatment liquid treated by one DC electric field cabinet is input into another DC electric field cabinet; 28. The substrate processing method according to any one of items 23 to 27, wherein the input cabinet selection step selects one of the DC electric field cabinets based on the contamination level measured in the measurement step.

[0037] 29. A substrate processing method described in any one of items 19 to 28, further comprising a step of controlling the strength of the DC electric field applied to the processing liquid by the DC electric field cabinet based on the type of the processing liquid, the type of foreign matter in the processing liquid, or the degree of contamination measured by the measurement step.

[0038] 30. The DC electric field cabinet includes a plurality of electrodes for applying a DC electric field in the treatment liquid, and a DC power supply for applying a DC voltage to the plurality of electrodes; 30. The substrate processing method according to any one of items 19 to 29, further comprising a step of controlling a DC voltage applied to the plurality of electrodes from the DC power source based on the type of the processing liquid, the type of foreign matter in the processing liquid, or the contamination level measured by the measuring step.

[0039] 31. The DC electric field cabinet includes a plurality of electrodes for applying a DC electric field to the treatment liquid; 31. The substrate processing method according to any one of items 19 to 30, further comprising an electrode arrangement changing step of changing the arrangement of the electrodes based on the type of the processing liquid, the type of foreign matter in the processing liquid, or the contamination level measured by the measuring step.

[0040] 32. A substrate processing method according to item 31, wherein the electrode arrangement changing step changes the spacing between the plurality of electrodes.

[0041] 33. A substrate processing method according to item 31 or 32, wherein the electrode position changing step changes the positions of the plurality of electrodes so that the area of ​​the immersed portion of the plurality of electrodes immersed in the processing liquid changes. [Brief explanation of the drawings]

[0042] [Figure 1] FIG. 1 is a system diagram for explaining the configuration of a substrate processing apparatus according to a first embodiment of the present invention. [Figure 2A] FIG. 2A shows an example of the configuration of a DC electric field cabinet. [Figure 2B] FIG. 2B shows another example of a DC field cabinet configuration. [Figure 2C] FIG. 2C shows yet another example of a DC electric field cabinet configuration. [Figure 3] FIG. 3 is a block diagram for explaining an example of an electrical configuration related to control of the substrate processing apparatus. [Figure 4]FIG. 4 shows an example of a sequence for cleaning a processing liquid using a DC electric field cabinet. [Figure 5] FIG. 5 is a flowchart illustrating an example of control over the DC electric field cabinet. [Figure 6] FIG. 6 is a system diagram for explaining an example of the configuration of a substrate processing apparatus according to a second embodiment of the present invention. [Figure 7] FIG. 7 shows an example of operation when the degree of contamination of the processing liquid is low. [Figure 8A] FIG. 8A shows an example of operation when the first DC electric field cabinet and the second DC electric field cabinet are used in a switchable manner for cleaning the processing liquid. [Figure 8B] FIG. 8B shows an example of operation when the first DC electric field cabinet and the second DC electric field cabinet are used in a switchable manner for cleaning the processing liquid. [Figure 9] FIG. 9 is a flowchart for explaining an example of the operation of the second embodiment. [Figure 10] FIG. 10 is a flowchart illustrating another example of operation. [Figure 11] FIG. 11 is a system diagram for explaining the configuration of a substrate processing apparatus according to a third embodiment of the present invention. [Figure 12] FIG. 12 is a system diagram for explaining the configuration of a substrate processing apparatus according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0043] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0044] FIG. 1 is a system diagram for explaining the configuration of a substrate processing apparatus according to a first embodiment of the present invention.

[0045] The substrate processing apparatus 1 includes a substrate processing unit 2 that supplies a processing liquid to a substrate W to process the substrate W, and a processing liquid supply path 10 that supplies the processing liquid to the substrate processing unit 2. A branch path 12 branches off from a branch point 11 set on the processing liquid supply path 10. More specifically, a flow path switching unit 13 is disposed at the branch point 11 and directs the processing liquid flowing from upstream of the branch point 11 toward either the processing liquid supply path 10 downstream of the branch point 11 or the branch path 12. The flow path switching unit 13 may be configured, for example, by a three-way valve, and the branch path 12 is connected to one port of this three-way valve. The branch path 12 is provided with a DC electric field cabinet 20 that stores the processing liquid and applies a DC electric field to the stored processing liquid to precipitate and remove contaminants in the processing liquid.

[0046] A contamination measurement unit 14 (first contamination measurement unit) that measures the contamination level of the processing liquid passing through the processing liquid supply path 10 is provided at a measurement point located upstream of the branch point 11 in the processing liquid supply path 10. The contamination measurement unit 14 may be, for example, a liquid particle counter (LPC) that measures the number of particles in the processing liquid flowing through the processing liquid supply path 10.

[0047] Meanwhile, a return path 16 that supplies the treatment liquid from the DC electric field cabinet 20 to the junction 15, which is set at a position different from the branch point 11 on the treatment liquid supply path 10, is connected to the return path 16 and joins the treatment liquid supply path 10. In this example, the junction 15 is located upstream of the branch point 11 and further upstream of the contamination measurement unit 14. A return pump 17 is installed in the return path 16, which sends the treatment liquid that has been treated in the DC electric field cabinet 20 toward the junction 15, and a return valve 18 (open / close valve) is installed downstream of the return pump 17.

[0048] A cleaning liquid path 23 is introduced into the DC electric field cabinet 20 to supply a cleaning liquid (for example, deionized water (DIW)) for cleaning the interior. A cleaning liquid valve 24 (open / close valve) is provided in the cleaning liquid path 23. A drainage path 21 is connected to the bottom to drain the liquid inside the DC electric field cabinet 20. A drainage valve 22 (open / close valve) is provided in the drainage path 21.

[0049] A filter 31 for removing foreign matter (particles) from the processing liquid is disposed in the processing liquid supply path 10 downstream of the branch point 11 and the confluence point 15.

[0050] In this embodiment, the processing liquid supply path 10 includes a processing liquid cabinet 30 (processing liquid tank) for storing the processing liquid. The processing liquid cabinet 30 is provided in the processing liquid supply path 10 downstream of the branch point 11 and the junction 15 and upstream of the filter 31. A processing liquid valve 32 (opening / closing valve) is provided in the processing liquid supply path 10 between the filter 31 and the substrate processing unit 2.

[0051] A circulation branch point 33 is disposed on the processing liquid supply path 10 between the processing liquid valve 32 and the filter 31, and a circulation path 34 branches off from this circulation branch point 33. The circulation path 34 is a path that returns the processing liquid to the processing liquid cabinet 30 and circulates it.

[0052] In addition to the filter 31, a pump 35 and a heater 36 are installed on the processing liquid supply path 10 between the processing liquid cabinet 30 and the circulation branch point 33. The pump 35 sends the processing liquid from the processing liquid cabinet 30 toward the substrate processing unit 2. The heater 36 heats the processing liquid. The processing liquid is typically a chemical liquid, and by heating it to a temperature higher than room temperature by the heater 36, the substrate W can be efficiently processed.

[0053] When the processing liquid valve 32 is closed, the processing liquid delivered by the pump 35 is heated by the heater 36 and circulated through the circulation path 34 while being subjected to a foreign matter removal process by the filter 31. When the processing liquid valve 32 is opened, the processing liquid delivered by the pump 35 is supplied to the substrate processing unit 2. At this time, a portion of the processing liquid may flow into the circulation path 34 and be returned to the processing liquid cabinet 30.

[0054] The substrate processing unit 2 includes, for example, a spin chuck 3 that holds and rotates the substrate W in a horizontal position, a processing liquid nozzle 4 that supplies a processing liquid to the substrate W held on the spin chuck 3, a cup 5 that receives the processing liquid discharged from the substrate W by centrifugal force, and a chamber 6 that accommodates these components. A processing liquid supply path 10 is connected to the processing liquid nozzle 4.

[0055] The cup 5 is connected to an inlet of a recovery path 40 that recovers the processing liquid used to process the substrate W. The outlet of the recovery path 40 is connected to the processing liquid supply path 10 upstream of the contamination measurement unit 14. A recovery valve 41 (open / close valve) is provided midway along the recovery path 40.

[0056] A new liquid supply path 45 that supplies unused processing liquid is also connected to the processing liquid supply path 10. The new liquid supply path 45 is connected to the processing liquid supply path 10 via a new liquid valve 46. In this embodiment, the new liquid supply path 45 is connected to the processing liquid supply path 10 upstream of the contamination measurement unit 14, and is configured so that the contamination level of unused processing liquid is also measured. However, if the cleanliness of the unused processing liquid can be guaranteed, the new liquid supply path 45 may be arranged to supply the processing liquid directly to the processing liquid cabinet 30.

[0057] The substrate processing apparatus 1 further includes a controller 50 for controlling each part of the apparatus.

[0058] 2A, 2B, and 2C show an example of the configuration of the DC electric field cabinet 20. The DC electric field cabinet 20 includes a tank 25 that stores a treatment liquid, a plurality of electrodes 26 for applying a DC electric field to the treatment liquid stored in the tank 25, and a DC power supply 27 that applies a DC voltage to the plurality of electrodes 26.

[0059] 2A and 2B, a pair of plate-like electrodes 26 oriented along the vertical direction are arranged in parallel and facing each other horizontally. The pair of electrodes 26 is connected to a DC power source 27 and is given different potentials. This forms a DC electric field between the pair of electrodes 26, and this DC electric field is applied to the processing liquid in tank 25. In the configuration shown in FIG. 2B, the area of ​​each electrode 26 is larger than that of the configuration shown in FIG. 2A.

[0060] 2C, three or more (four in the illustrated example) plate-like electrodes 26 are arranged in parallel and oriented vertically, with adjacent electrodes 26 facing each other horizontally. A DC voltage is applied between each pair of opposing electrodes 26 from a DC power supply 27. Therefore, a DC electric field is formed between each pair of electrodes 26, and this DC electric field is applied to the processing liquid in tank 25.

[0061] In order to prevent corrosion of the electrode 26 (particularly corrosion caused by chemicals), the surface of the electrode 26 is preferably coated with a resin.

[0062] The strength of the DC electric field is proportional to the DC voltage applied to the pair of opposing electrodes 26 and inversely proportional to the distance (spacing) between the pair of opposing electrodes 26. Therefore, the strength of the DC electric field applied to the treatment liquid increases as the DC voltage increases and decreases as the distance between the electrodes decreases. For example, in the configurations of Figures 2A and 2B, if the distance between the pair of electrodes 26 is equal and the DC voltage applied from the DC power supply 27 is equal, the strength of the DC electric field applied to the treatment liquid is equal. The configuration of Figure 2B has a larger surface area of ​​the electrodes 26, allowing a DC electric field to be applied to a wider area of ​​the treatment liquid. In Figure 2C, the distance between the pair of opposing electrodes 26 is shorter, making it easier to increase the strength of the DC electric field applied to the treatment liquid. Furthermore, since the total surface area of ​​the electrodes 26 can be increased, a DC electric field can be applied to a wider area of ​​the treatment liquid.

[0063] The DC electric field cabinet 20 may have an electrode positioning changer 28 that changes the position of the multiple electrodes 26. The electrode positioning changer 28 may be configured to change the spacing (inter-electrode distance) between the opposing electrodes 26. Changing the spacing between the electrodes 26 makes it possible to change the strength of the DC electric field applied to the treatment liquid. Furthermore, the electrode positioning changer 28 may be configured to change the position of the multiple electrodes 26 so as to change the area of ​​the immersed portions of the multiple electrodes 26 that are immersed in the treatment liquid.

[0064] More specifically, the electrode positioning changer 28 may be configured to change the area of ​​the immersed portion of one or more electrodes 26 by moving one or more electrodes 26 up and down. For example, in the configuration of FIG. 2C , the two outer electrodes 26 may be fixed electrodes, and the two inner electrodes 26 may be movable electrodes that can move up and down. In this case, the electrode positioning changer 28 can set multiple electrode positionings, such as an electrode positioning in which both of the inner electrodes 26 are positioned at an upper position removed from the processing solution, an electrode positioning in which one of the inner electrodes 26 is positioned at an upper position removed from the processing solution and the other is positioned at a lower position immersed in the processing solution, an electrode positioning in which both of the inner electrodes 26 are positioned at a lower position immersed in the processing solution, or an electrode positioning in which one or two of the inner electrodes 26 are partially immersed in the processing solution. This makes it possible to change the distance between the opposing electrodes 26 and change the electrode area that applies a DC electric field to the processing solution.

[0065] Applying a DC electric field to a liquid containing fine particles can cause the particles to aggregate and settle, thereby separating and removing them from the liquid. This is described, for example, in Patent Document 2 and Non-Patent Document 1. Applying a DC electric field to a liquid causes distortion in the electric double layer of solid particles in the liquid, which generates an attractive force between the solid particles, causing them to aggregate. The aggregated fine particles settle in the liquid, resulting in a high solid particle density at deeper positions in the liquid and a low solid density at shallower positions in the liquid. By utilizing this principle, foreign matter (particles) in the processing liquid can be aggregated and separated and removed from the processing liquid.

[0066] That is, the DC electric field cabinet 20 can apply a DC electric field to the treatment liquid between the electrodes 26, thereby flocculating foreign matter (particles) in the treatment liquid and causing them to settle and separate at the bottom of the tank 25. The precipitates can be removed by discharging them from the drainage path 21.

[0067] Non-Patent Document 1 reports that particles can be chemically aggregated by applying a DC electric field of 5 V to 20 V, that the stronger the DC electric field (the greater the electric field strength), the more effective it is for particle aggregation, that stirring the liquid hinders aggregation, that the further the pH (hydrogen ion concentration) of the slurry is from the isoelectric point of the particle surface, the more particle aggregation is hindered (i.e., the closer it is to the isoelectric point, the easier it is to aggregate), and that the longer the electric field is applied, the faster the particle settling speed increases.

[0068] Among the processing solutions used in processing semiconductor substrates, the pH of water-soluble processing solutions affects their tendency to agglomerate. Furthermore, the tendency to agglomerate also varies depending on the type of foreign matter (particles). For example, alumina, cerium oxide, and carbon black are prone to agglomeration, while silicon oxide and titanium oxide have weak agglomeration strength. Therefore, foreign matter (particles) in a processing solution can be efficiently removed by applying a DC electric field of appropriate (just the right) strength to the processing solution and setting an appropriate (just the right) processing time depending on the type of processing solution (especially pH) and the type of foreign matter (particle) contained in the processing solution.

[0069] FIG. 3 is a block diagram illustrating an example of an electrical configuration related to control of the substrate processing apparatus 1. As shown in FIG.

[0070] The substrate processing apparatus 1 includes a controller 50 for controlling a plurality of control objects. The controller 50 has the basic configuration of a computer, and includes a processor 50p (CPU) and a storage device 50m (memory, storage, etc.). The storage device 50m stores a program executed by the processor 50p, and also stores a recipe that defines the contents of the substrate processing (processing conditions, processing procedures, etc.). The processor 50p operates in accordance with the program and the recipe, and the controller 50 controls the control objects to realize various functions.

[0071] The objects controlled by the controller 50 include the spin chuck 3, the flow path switching unit 13, the return pump 17, the return valve 18, the cleaning liquid valve, the drain valve 22, the processing liquid valve 32, the pump 35, the heater 36, the recovery valve 41, the new liquid valve 46, the DC power supply 27, and the electrode arrangement changing unit 28. Figure 3 also shows the objects controlled by the controller 50 in other embodiments, which will be described later.

[0072] The controller 50 receives an input of the contamination level detected by the contamination measurement unit 14. The controller 50 may also be connected to a display device 51 and an input device 52 that provide a machine interface. An operator of the substrate processing apparatus 1 can input various information and commands to the substrate processing apparatus 1 by operating the input device 52. For example, information regarding the type of processing liquid and information regarding the type of foreign matter (particles) contained in the processing liquid may be input from the input device 52. The controller 50 may then perform control related to the DC electric field cabinet 20, such as control to adjust the strength of the DC electric field and control to set the time for applying the DC electric field, based on the input information and / or the contamination level measured by the contamination measurement unit 14. FIG. 4 shows an example of a sequence for cleaning a processing liquid using the DC electric field cabinet 20.

[0073] The processing liquid introduced into the processing liquid supply path 10 is guided to the contamination measurement unit 14, where its contamination level is measured (step S1: measurement step). Specifically, the number of particles contained in the processing liquid is measured. The measurement result by the contamination measurement unit 14 is input to the controller 50. When the measured contamination level is low, more specifically, when the contamination level is equal to or lower than a predetermined threshold (step S2: NO), the controller 50 controls the flow path switching unit 13 to supply the processing liquid to the processing liquid cabinet 30 (step S3: flow path switching step). The processing liquid supplied to the processing liquid cabinet 30 is filtered by the filter 31 (filter step) and then used for substrate processing in the substrate processing unit 2 (step S4). On the other hand, when the measured contamination level is high, more specifically, when the contamination level exceeds the threshold (step S2: YES), the controller 50 controls the flow path switching unit 13 to supply the processing liquid to the DC electric field cabinet 20 (step S5: flow path switching step).

[0074] For example, the threshold for contamination level may be 100 particles / mL for a particle density of 0.5 μm or larger in diameter. For a processing liquid (e.g., IPA (isopropyl alcohol)) supplied in the final stage of substrate processing, the threshold for contamination level may be 100 particles / mL for a particle density of 0.2 μm or larger in diameter.

[0075] In the DC electric field cabinet 20, a DC electric field is applied to the processing liquid, causing particles in the processing liquid to settle and accumulate at the bottom of the tank 25. This reduces the particle density in the supernatant portion of the processing liquid in the tank 25. Therefore, the controller 50 opens the return valve 18 and operates the return pump 17 to suck up the supernatant portion, while opening the drain valve 22 to drain the precipitate portion (step S6: purification step, processing liquid return step). As a result, the purified processing liquid is supplied to the processing liquid supply path 10 at the junction 15 upstream of the contamination measurement unit 14. This processing liquid is again measured by the contamination measurement unit 14. Depending on the measurement results, the same sequence is repeated.

[0076] By this sequence, the processing liquid cabinet 30 stores clean processing liquid with a contamination level below the threshold. Accordingly, fewer foreign objects (particles) are captured by the filter 31, reducing the frequency of filter replacement. This reduces the frequency of maintenance work for filter replacement, thereby shortening the interruption period of substrate processing, contributing to improved productivity. Furthermore, in this embodiment, the used processing liquid recovered from the substrate processing unit 2 via the recovery path 40 (processing liquid recovery step) is reused, thereby reducing the consumption of processing liquid and reducing the frequency of maintenance for filter replacement.

[0077] FIG. 5 is a flowchart for explaining an example of control over the DC electric field cabinet 20.

[0078] The controller 50 may acquire one or more of information regarding the type of processing liquid, information regarding the type of foreign matter in the processing liquid, and the degree of contamination measured by the contamination measurement unit 14 (steps S11, S12, S13), and based on one or more of these, control the strength of the DC electric field applied by the DC electric field cabinet 20 to the processing liquid (step S14: step of controlling the strength of the DC electric field).

[0079] Information regarding the type of processing liquid and the type of foreign matter may be acquired by the controller 50, for example, by an operator inputting the information through the input device 52 as described above. Alternatively, information regarding the type of processing liquid and the type of foreign matter may be provided to the controller 50 from a host computer (not shown) that can communicate with the controller 50. If the type of foreign matter (particle) contained in the processing liquid can be identified based on the type of processing liquid, the controller 50 can use the information regarding the type of processing liquid as information for identifying the type of foreign matter. Information regarding the type of processing liquid may be provided to the controller 50 from the input device 52 or the host computer described above, or may be included in the substrate processing recipe.

[0080] Depending on the type of treatment liquid, the controller 50 may strengthen the DC electric field as the pH of the treatment liquid deviates from the isoelectric point. Furthermore, the controller 50 may weaken the DC electric field for foreign matter species that are prone to agglomeration, and strengthen the DC electric field for foreign matter species that are difficult to agglomerate. Meanwhile, the control of the strength of the DC electric field based on the degree of contamination measured by the contamination measurement unit 14 may be such that the DC electric field is strengthened as the degree of contamination increases.

[0081] The strength of the DC electric field can be changed by controlling (increasing or decreasing) the DC voltage applied from the DC power supply 27 to the electrodes 26 (step S141: step of controlling DC voltage). The strength of the DC electric field can also be changed by changing the distance between the opposing electrodes 26. Therefore, the controller 50 may control the strength of the DC electric field by controlling one or both of the DC power supply 27 and the electrode placement changing unit 28 (step S142: electrode placement changing step). In this case, the electrode placement changing unit 28 changes the distance between the electrodes 26, thereby changing the strength of the DC electric field applied to the treatment liquid.

[0082] On the other hand, the control of the electrode repositioning unit 28 based on the contamination level may include control to change the area of ​​the electrode portion immersed in the treatment liquid by changing the electrode repositioning by the electrode repositioning unit 28 (step S15: electrode repositioning step). The larger the area of ​​the immersed portion, the higher the treatment efficiency of the DC electric field cabinet 20, and the more particles can be settled in a short period of time. Therefore, by controlling the electrode repositioning so that the area of ​​the immersed portion changes according to the contamination level measured by the contamination measurement unit 14, it is possible to achieve just the right amount of contamination removal performance appropriate for the contamination level.

[0083] 6 is a system diagram for explaining an example of the configuration of a substrate processing apparatus 1 according to a second embodiment of the present invention. In FIG. 6, parts corresponding to those shown in FIG. 1 are denoted by the same reference numerals.

[0084] In this embodiment, multiple DC electric field cabinets 20 are provided. Specifically, a first DC electric field cabinet 20A and a second DC electric field cabinet 20B are provided. With regard to the first DC electric field cabinet 20A, parts corresponding to those of the DC electric field cabinet 20 in FIG. 1 are indicated by symbols with the same symbols as in FIG. 1 but with the addition of "A." Similarly, with regard to the second DC electric field cabinet 20B, parts corresponding to those of the DC electric field cabinet 20 in FIG. 1 are indicated by symbols with the same symbols as in FIG. 1 but with the addition of "B."

[0085] The branch path 12 further branches into a first input path 12A that guides the treatment liquid to the first DC electric field cabinet 20A and a second input path 12B that guides the treatment liquid to the second DC electric field cabinet 20B. The branch path 12 is provided with an input cabinet selector 61 (first input cabinet selector) that guides the treatment liquid guided to the branch path 12 at the branch point 11 to either the first DC electric field cabinet 20A or the second DC electric field cabinet 20B. The input cabinet selector 61 can be, for example, a three-way valve connected to the branch path 12, the first input path 12A, and the second input path 12B. The input cabinet selector 61 is controlled by the controller 50 to guide the treatment liquid guided to the branch path 12 to either the first input path 12A or the second input path 12B.

[0086] In addition, the flow path switching unit 13 and the input cabinet selector 61 may be composed of a multi-valve including a manifold connected to the processing liquid supply path 10, the first input path 12A and the second input path 12B, and an opening / closing valve interposed in each of the processing liquid supply path 10, the first input path 12A and the second input path 12B.

[0087] On the other hand, the return path 16 has a first return branch path 16A that guides the processing liquid from the first DC electric field cabinet 20A, a second return branch path 16B that guides the processing liquid from the second DC electric field cabinet 20B, and a collective return path 16C where these paths join together. The outlet of the collective return path 16C joins the processing liquid supply path 10 at a junction 15. The return path 16 is provided with a return cabinet selector 62 that guides the processing liquid that has been purified in one of the multiple DC electric field cabinets 20, i.e., the first DC electric field cabinet 20A or the second DC electric field cabinet 20B, to the return path 16 (collective return path 16C). The return cabinet selector 62 is controlled by the controller 50. In the illustrated example, the return cabinet selector 62 includes two return valves 18A and 18B that are respectively provided in the first return branch path 16A and the second return branch path 16B. Instead of the two return valves 18A, 18B, a three-way valve connected to the first return branch path 16A, the second return branch path 16B and the collective return path 16C may be used as the return cabinet selector 62.

[0088] With this configuration, the cleaning sequence (see FIG. 4) described in the first embodiment can be executed. In addition, the first DC electric field cabinet 20A and the second DC electric field cabinet 20B can be switched between for use.

[0089] 7, 8A and 8B show an example of operation when first DC electric field cabinet 20A and second DC electric field cabinet 20B are used in a switchable manner.

[0090] First, when the contamination level of the processing liquid introduced into the processing liquid supply path 10 and introduced into the contamination measurement unit 14 is low (when the contamination level is equal to or lower than a threshold value), as shown in FIG. 7 , the controller 50 controls the flow path switching unit 13 to guide the processing liquid introduced into the processing liquid supply path 10 and subjected to contamination measurement by the contamination measurement unit 14 to the processing liquid supply path 10 downstream of the branch point 11. Thus, the processing liquid is supplied to the processing liquid cabinet 30. During substrate processing, the processing liquid valve 32 is opened, and the processing liquid pumped out of the processing liquid cabinet 30 is supplied to the substrate processing unit 2. When the processing liquid valve 32 is closed, the processing liquid pumped out of the processing liquid cabinet 30 is returned to the processing liquid cabinet 30 through the circulation path 34, where it is circulated while being temperature-adjusted by the heater 36 and filtered by the filter 31.

[0091] When the contamination level of the processing liquid introduced into the processing liquid supply path 10 and introduced into the contamination measurement unit 14 is high (when the contamination level exceeds a threshold value), as shown in Figures 8A and 8B, the controller 50 controls the flow path switching unit 13 to guide the processing liquid introduced into the processing liquid supply path 10 and subjected to contamination measurement by the contamination measurement unit 14 from the branch point 11 to the branch path 12. The controller 50 controls the input cabinet selector 61 and the return cabinet selector 62 so that another DC electric field cabinet 20 is selected by the input cabinet selector 61 and the return cabinet selector 62, respectively.

[0092] 8A shows a state in which the input cabinet selector 61 (three-way valve) selects the first DC electric field cabinet 20A, and the return cabinet selector 62 (three-way valve) selects the second DC electric field cabinet 20B. At this time, the processing liquid introduced into the processing liquid supply path 10 is guided to the branch path 12 at the branch point 11, and further guided to the first input path 12A by the input cabinet selector 61 and introduced into the first DC electric field cabinet 20A. Meanwhile, the supernatant portion of the processing liquid stored in the second DC electric field cabinet 20B is pumped into the second return branch path 16B by the return pump 17B, passes through the return cabinet selector 62 (return valves 18A, 18B), and is supplied to the processing liquid supply path 10 from the collected return path 16C.

[0093] 8B shows a state in which the input cabinet selector 61 (three-way valve) selects the second DC electric field cabinet 20B, and the return cabinet selector 62 (three-way valve) selects the first DC electric field cabinet 20A. At this time, the processing liquid introduced into the processing liquid supply path 10 is guided to the branch path 12 at the branch point 11, and further guided to the second input path 12B by the input cabinet selector 61 and introduced into the second DC electric field cabinet 20B. Meanwhile, the supernatant portion of the processing liquid stored in the first DC electric field cabinet 20A is pumped into the first return branch path 16A by the return pump 17A, passes through the return cabinet selector 62 (return valves 18A, 18B), and is supplied to the processing liquid supply path 10 from the collected return path 16C.

[0094] FIG. 9 is a flowchart illustrating an example of the operation.

[0095] 8A, assume a state in which the processing liquid is introduced into the first DC electric field cabinet 20A, and the purified processing liquid is returned from the second DC electric field cabinet 20B to the processing liquid supply path 10 (step S21). In this state, the processing liquid is stored in the first DC electric field cabinet 20A until the liquid level reaches a predetermined full level.

[0096] When the liquid level of the processing liquid stored in the first DC electric field cabinet 20A reaches the full level (step S22: YES), the controller 50 switches the input cabinet selector 61 and the return cabinet selector 62 to the state shown in Fig. 8B (step S23: input cabinet selection step, return cabinet selection step). Then, in the state shown in Fig. 8B, the processing liquid is stored in the second DC electric field cabinet 20B until the liquid level reaches a predetermined full level.

[0097] When the liquid level of the processing liquid stored in the second DC electric field cabinet 20B reaches the full level (step S24: YES), the controller 50 switches the input cabinet selector 61 and the return cabinet selector 62 to the state shown in FIG. 8A (step S21: input cabinet selection step, return cabinet selection step).

[0098] This operation is repeated, and the roles of the two DC electric field cabinets 20A and 20B are alternately switched to remove foreign matter (particles) from the highly contaminated processing liquid.

[0099] When the treatment liquid is introduced into the DC electric field cabinet 20, the treatment liquid is agitated, which inhibits aggregation and sedimentation of fine particles. Therefore, by introducing the treatment liquid into one DC electric field cabinet 20 and pumping out the supernatant of the treatment liquid from another DC electric field cabinet 20, the fine particles in the treatment liquid can be efficiently separated and the treatment liquid can be efficiently purified.

[0100] The same applies when three or more DC cabinets are used; for example, one DC electric field cabinet 20 may be selected in a sequential and cyclical manner to input the treatment liquid led to the branch path 12, while another DC electric field cabinet 20 may be selected in a sequential and cyclical manner to pump out the supernatant portion of the treatment liquid.

[0101] As shown in Figures 8A and 8B, as in the case of Figure 7, the supply of processing liquid from the processing liquid cabinet 30 to the substrate processing unit 2 and the circulation of the processing liquid via the circulation path 34 can continue even during the cleaning process using the DC electric field cabinet 20.

[0102] FIG. 10 is a flowchart illustrating another example of operation.

[0103] In this operation example, the controller 50 controls the flow path switching unit 13 and also controls the input cabinet selector 61 based on the degree of contamination of the processing liquid measured by the contamination measuring unit 14 .

[0104] The controller 50 acquires the contamination level measured by the contamination measurement unit 14 (step S31), and if the contamination level is equal to or lower than a predetermined first threshold value (step S32: NO), controls the flow path switching unit 13 to guide the processing liquid to the processing liquid supply path 10 downstream of the branch point 11. Therefore, the processing liquid is supplied to the processing liquid cabinet 30 (step S33). On the other hand, if the contamination level exceeds the first threshold value (step S32: YES), the controller 50 controls the flow path switching unit 13 to guide the processing liquid to the branch path 12.

[0105] Furthermore, the controller 50 compares the contamination level measured by the contamination measurement unit 14 with a predetermined second threshold value that is greater than the first threshold value (step S34). If the contamination level is equal to or less than the second threshold value (step S34: NO), the controller 50 controls the input cabinet selector 61 to select the second DC electric field cabinet 20B (input cabinet selection step). Therefore, the processing liquid with a relatively low contamination level is input into the second DC electric field cabinet 20B (step S36). If the contamination level exceeds the second threshold value (step S34: YES), the controller 50 controls the input cabinet selector 61 to select the first DC electric field cabinet 20A (input cabinet selection step). Therefore, the processing liquid with a relatively high contamination level is input into the first DC electric field cabinet 20A (step S35).

[0106] The first DC electric field cabinet 20A and the second DC electric field cabinet 20B may have different electrode 26 areas that come into contact with the treatment liquid. More specifically, the contact area of ​​the electrode 26 of the first DC electric field cabinet 20A with the treatment liquid is preferably larger than the contact area of ​​the electrode 26 of the second DC electric field cabinet 20B with the treatment liquid. This allows the first DC electric field cabinet 20A to have a higher cleaning performance than the second DC electric field cabinet 20B. Therefore, by introducing a relatively less contaminated treatment liquid into the second DC electric field cabinet 20B and a relatively more contaminated treatment liquid into the first DC electric field cabinet 20A, appropriate cleaning treatment can be performed depending on the level of contamination. For example, the first DC electric field cabinet 20A may have the configuration shown in FIG. 2B or 2C, and the second DC electric field cabinet 20B may have the configuration shown in FIG. 2A.

[0107] The strength of the DC electric field applied to the treatment liquid may be different between the first DC electric field cabinet 20A and the second DC electric field cabinet 20B. More specifically, the strength of the DC electric field applied to the treatment liquid in the first DC electric field cabinet 20A is preferably stronger than the strength of the DC electric field applied to the treatment liquid in the second DC electric field cabinet 20B. This allows the first DC electric field cabinet 20A to have a higher cleaning performance than the second DC electric field cabinet 20B. Therefore, by introducing a treatment liquid with a relatively low level of contamination into the second DC electric field cabinet 20B and introducing a treatment liquid with a relatively high level of contamination into the first DC electric field cabinet 20A, an appropriate cleaning process can be performed depending on the level of contamination. As described above, the strength of the DC electric field can be adjusted by the DC voltage applied to the electrodes 26 provided in the first DC electric field cabinet 20A and the second DC electric field cabinet 20B and / or the spacing between the electrodes 26.

[0108] It is also possible to provide three or more DC electric field cabinets 20 with different electrode 26 areas or DC electric field intensities, and use them according to the degree of contamination of the processing liquid.

[0109] Furthermore, when using multiple DC electric field cabinets 20 with different DC electric field strengths, in addition to or instead of the judgment based on the contamination level (step S34), an appropriate DC electric field cabinet may be selected depending on the type of processing liquid and the type of foreign matter (particle type).

[0110] 11 is a system diagram for explaining the configuration of a substrate processing apparatus 1 according to a third embodiment of the present invention. In FIG. 11, parts corresponding to those shown in FIG. 6 are given the same reference numerals.

[0111] In this embodiment, the multiple DC electric field cabinets 20 are connected in series so that the processing liquid processed by one DC electric field cabinet 20 is input to the other DC electric field cabinets 20. Specifically, the processing liquid (supernatant portion of the stored processing liquid) purified by the first DC electric field cabinet 20A is transferred to the second DC electric field cabinet 20B through a transfer path 65. A transfer pump 66 installed in the transfer path 65 sends the processing liquid purified by the first DC electric field cabinet 20A to the second DC electric field cabinet 20B through the transfer path 65. Then, the processing liquid (supernatant portion of the stored processing liquid) purified by the second DC electric field cabinet 20B is returned to the processing liquid supply path 10 at the junction 15 through a return path 16. No return path is provided for returning the processing liquid directly from the first DC electric field cabinet 20A to the junction 15.

[0112] The controller 50 controls the input cabinet selector 61 based on the contamination level measured by the contamination measurement unit 14. The control operation in this case is the same as that in FIG. 10 . That is, if the contamination level exceeds the first threshold value (step S32: YES), the processing liquid is guided to the branch path 12. If the contamination level is equal to or lower than the second threshold value (step S34: NO), the controller 50 controls the input cabinet selector 61 to select the second DC electric field cabinet 20B (input cabinet selection step). Therefore, the processing liquid with a relatively low contamination level is input to the second DC electric field cabinet 20B (step S36). If the contamination level exceeds the second threshold value (step S34: YES), the controller 50 controls the input cabinet selector 61 to select the first DC electric field cabinet 20A (input cabinet selection step). Therefore, the processing liquid with a relatively high contamination level is input to the first DC electric field cabinet 20A (step S35).

[0113] As a result, for processing liquids with a relatively high level of contamination, a two-stage purification process is performed using the first DC electric field cabinet 20A and the second DC electric field cabinet 20B. On the other hand, for processing liquids with a relatively low level of contamination, a single-stage purification process is performed using only the second DC electric field cabinet 20B. This allows for efficient purification processes appropriate to the level of contamination.

[0114] 12 is a system diagram for explaining the configuration of a substrate processing apparatus 1 according to a fourth embodiment of the present invention. In FIG. 12, parts corresponding to those shown in FIG. 11 are given the same reference numerals.

[0115] In this embodiment, a second contamination measurement unit 70 (e.g., a liquid-borne particle counter) and a second input cabinet selector 71 (a three-way valve in this embodiment) are interposed in the transfer path 65. The second contamination measurement unit 70 measures the contamination level of the processing liquid that has been purified in the first DC electric field cabinet 20A and led to the transfer path 65 by the transfer pump 66, and inputs the measurement result to the controller 50. The second input cabinet selector 71 switches the flow path so that the processing liquid whose contamination level has been measured is led to either the first DC electric field cabinet 20A or the second DC electric field cabinet 20B.

[0116] The controller 50 compares the contamination level measured by the second contamination measurement unit 70 with a third threshold value (e.g., a value equal to or smaller than the second threshold value) and controls the second input cabinet selector 71 based on the comparison result. Specifically, if the contamination level is equal to or smaller than the third threshold value, the controller 50 controls the second input cabinet selector 71 to select the second DC electric field cabinet 20B as the processing liquid input destination. On the other hand, if the contamination level exceeds the third threshold value, the controller 50 controls the second input cabinet selector 71 to select the first DC electric field cabinet 20A as the processing liquid input destination.

[0117] As a result, the first stage of cleaning treatment in the first DC electric field cabinet 20A is repeated until the treatment liquid is purified to a degree suitable for the cleaning treatment in the second DC electric field cabinet 20B, and the treatment liquid that has been properly purified in the first stage of cleaning treatment can be subjected to the second cleaning treatment in the second DC electric field cabinet 20B. In this way, the treatment liquid can be reliably purified.

[0118] Although the embodiment of the present invention has been described above, the present invention can also be embodied in other forms.

[0119] For example, as shown by the two-dot chain line in Fig. 1, the junction 15 at which the return path 16, which guides the processing liquid that has been purified in the DC electric field cabinet 20, joins the processing liquid supply path 10 may be located on the processing liquid supply path 10 downstream of the branch point 11 and upstream of the filter 31. In the illustrated example, the processing liquid cabinet 30 serves as the junction 15. The same applies to the configurations in Figs. 6, 11, and 12, where the return path 16 may join the processing liquid supply path 10 at a junction downstream of the branch point 11 (for example, the processing liquid cabinet 30).

[0120] 1 , a buffer tank 29 may be provided midway along the branch path 12. For example, when the processing liquid is stored in the DC electric field cabinet 20 up to a predetermined full level, the controller 50 blocks the flow of the processing liquid from the buffer tank 29 to the DC electric field cabinet 20. For example, the controller 50 closes an on-off valve (not shown) disposed on the branch path 12 between the buffer tank 29 and the DC electric field cabinet 20. This allows the DC electric field to be applied to the processing liquid in the DC electric field cabinet 20 without stirring due to the inflow of the processing liquid, thereby flocculating and settling the particles. This results in a supernatant portion of the processing liquid with a low density of foreign particles, enabling efficient purification, and the highly purified processing liquid can be sent to the return path 16.

[0121] Furthermore, in the above embodiment, the substrate processing section 2 is a single-wafer type that processes substrates W one by one, but of course, a batch-type substrate processing section that processes a plurality of substrates at once may also be used.

[0122] The substrate processing unit 2 may also perform physical processing on the surface of the substrate W while supplying a processing liquid to the surface of the substrate W. For example, the substrate processing unit 2 may perform chemical mechanical polishing (CMP) to polish the surface of the substrate W while supplying a slurry as the processing liquid. In this case, particles may be collected from the sediment separated by settling in the DC electric field cabinet 20, and the collected particles may be mixed with deionized water and reused to prepare slurry.

[0123] Additionally, the features described with respect to each embodiment may be combined in any combination.

[0124] In addition, various design modifications can be made within the scope of the claims. [Explanation of symbols]

[0125] 1: Substrate processing equipment 2: Substrate processing section 10: Processing liquid supply path 11: Branching point 12: Branching Route 12A: First input route 12B: Second input path 13: Flow path switching section 14: Contamination measurement section 15: Confluence 16: Return route 16A: First return branch path 16B: Second return branch path 16C: Collective return route 17: Return pump 17A: Return pump 17B: Return pump 18: Return valve 18A: Return valve 18B: Return valve 20: DC electric field cabinet 20A: First DC electric field cabinet 20B: Second DC electric field cabinet 21: Drainage route 22: Drain valve 26: Electrode 27:DC power supply 28: Electrode placement change unit 30: Processing liquid cabinet 31: Filter 40: Recovery route 41: Recovery valve 50: Controller 52: Input device 61: Input cabinet selector 62: Return cabinet selector 65:Transportation route 66: Transfer pump 70: Contamination measurement section 71: Input cabinet selector W: Substrate

Claims

1. a substrate processing unit that supplies a processing liquid to a substrate to process the substrate; a processing liquid supply path for supplying the processing liquid to the substrate processing unit; a branch path branching from a branch point on the processing liquid supply path; a DC electric field cabinet provided in the branch path, which stores the treatment liquid and applies a DC electric field to the stored treatment liquid to precipitate and remove contaminants in the treatment liquid; a return path that joins the processing solution supply path at a joining point on the processing solution supply path and supplies the processing solution from the DC electric field cabinet to the joining point; a filter provided in the treatment liquid supply path downstream of the branch point and the confluence point to remove foreign matter from the treatment liquid; a contamination measuring unit that is provided in the processing liquid supply path upstream of the branch point and that measures a contamination level of the processing liquid passing through the processing liquid supply path; a flow path switching unit that guides the treatment liquid flowing from upstream of the branch point toward the branch point to either the treatment liquid supply path downstream of the branch point or the branch path; a controller that controls the flow path switching unit based on the degree of contamination measured by the contamination measuring unit.

2. The substrate processing apparatus according to claim 1 , wherein the confluence is located on the processing liquid supply path upstream of the contamination measurement unit.

3. The substrate processing apparatus according to claim 1 , wherein the junction is disposed on the processing liquid supply path between the branch point and the filter.

4. 4. The substrate processing apparatus according to claim 1, further comprising a recovery path connected to the processing liquid supply path upstream of the contamination measurement unit, for recovering the used processing liquid used for processing the substrate from the substrate processing unit and guiding it to the processing liquid supply path.

5. 4. The substrate processing apparatus according to claim 1, further comprising a processing liquid cabinet provided in the processing liquid supply path downstream of the branching point and the confluence point and upstream of the filter, the processing liquid being stored therein.

6. a processing liquid valve interposed in the processing liquid supply path between the filter and the substrate processing unit; 6. The substrate processing apparatus according to claim 5, further comprising a circulation path that branches off from a circulation branch point located on the processing liquid supply path between the processing liquid valve and the filter, and returns the processing liquid to the processing liquid cabinet for circulation.

7. a plurality of said DC electric field cabinets; 4. The substrate processing apparatus according to claim 1, further comprising an input cabinet selector that guides the processing liquid guided to the branch path at the branch point to one of the plurality of DC electric field cabinets and inputs the processing liquid.

8. The substrate processing apparatus according to claim 7 , further comprising a return cabinet selector that guides the processing liquid that has been processed in any of the plurality of DC electric field cabinets to the return path.

9. The substrate processing apparatus of claim 8 , wherein the controller controls the input cabinet selector and the return cabinet selector so that another of the DC electric field cabinets is selected by the input cabinet selector and the return cabinet selector, respectively.

10. The DC electric field cabinets have electrodes with different areas in contact with the treatment liquid, The substrate processing apparatus according to claim 7 , wherein the controller controls the input cabinet selector based on the degree of contamination measured by the contamination measuring unit.

11. The DC electric field cabinets have different DC electric field intensities applied to the treatment liquid, The substrate processing apparatus according to claim 7 , wherein the controller controls the input cabinet selector based on the degree of contamination measured by the contamination measuring unit.

12. the plurality of DC electric field cabinets are connected in series so that the treatment liquid treated in one DC electric field cabinet is input into another DC electric field cabinet; The substrate processing apparatus according to claim 7 , wherein the controller controls the input cabinet selector based on the degree of contamination measured by the contamination measuring unit.

13. The substrate processing apparatus according to any one of claims 1 to 3, wherein the controller controls the strength of the DC electric field applied to the processing liquid by the DC electric field cabinet based on information on the type of the processing liquid, information on the type of foreign matter in the processing liquid, or the degree of contamination measured by the contamination measurement unit.

14. the DC electric field cabinet includes a plurality of electrodes for applying a DC electric field to the treatment liquid, and a DC power supply for applying a DC voltage to the plurality of electrodes; 4. The substrate processing apparatus according to claim 1, wherein the controller controls the DC voltage applied to the plurality of electrodes from the DC power supply based on information on the type of the processing liquid, information on the type of foreign matter in the processing liquid, or the degree of contamination measured by the contamination measurement unit.

15. the DC electric field cabinet includes a plurality of electrodes for applying a DC electric field to the treatment liquid, and an electrode arrangement changing unit for changing the arrangement of the plurality of electrodes; 4. The substrate processing apparatus according to claim 1, wherein the controller controls the electrode arrangement change unit based on information on the type of the processing liquid, information on the type of foreign matter in the processing liquid, or the degree of contamination measured by the contamination measurement unit.

16. The substrate processing apparatus according to claim 15 , wherein the electrode arrangement changing unit changes the spacing between the plurality of electrodes.

17. The substrate processing apparatus according to claim 15 , wherein the electrode arrangement changing unit changes the arrangement of the plurality of electrodes so that an area of ​​a portion of the plurality of electrodes immersed in the processing liquid changes.

18. 4. The substrate processing apparatus according to claim 1, wherein the DC electric field cabinet includes an electrode having a surface coated with a resin.

19. a measuring step of measuring a contamination level of the processing liquid passing through a processing liquid supply path that supplies the processing liquid to a substrate processing unit; a flow path switching step of guiding the processing liquid to either a branch path branching from a branch point on the processing liquid supply path or the processing liquid supply path downstream of the branch point, depending on the measured contamination level; a purification step of introducing the treatment liquid introduced into the branch path into a DC electric field cabinet, and applying a DC electric field to the treatment liquid in the DC electric field cabinet to precipitate and remove contaminants in the treatment liquid, thereby purifying the treatment liquid; a processing liquid returning step of returning the processing liquid purified in the DC electric field cabinet to the processing liquid supply path at a junction on the processing liquid supply path; a filtering step of removing foreign matter from the processing liquid by a filter provided in the processing liquid supply path downstream of the branch point and the junction point.

20. 20. The substrate processing method according to claim 19, wherein the confluence is located upstream of a measurement point on the processing liquid supply path where the contamination level is measured.

21. 20. The substrate processing method according to claim 19, wherein the junction is disposed on the processing liquid supply path between the branch point and the filter.

22. 22. The substrate processing method according to claim 19, further comprising a processing liquid recovery step of recovering the processing liquid used for processing the substrate in the substrate processing unit and guiding the used processing liquid to the processing liquid supply path upstream of a measurement point on the processing liquid supply path where the contamination level is measured.

23. a plurality of said DC electric field cabinets are provided; The substrate processing method according to any one of claims 19 to 21, further comprising an input cabinet selection step of guiding and inputting the processing liquid led to the branch path at the branch point into one of the plurality of DC electric field cabinets.

24. 24. The substrate processing method according to claim 23, further comprising a return cabinet selecting step of guiding the processing liquid that has been processed in any of the plurality of DC electric field cabinets to the processing liquid supply path.

25. The substrate processing method of claim 24, wherein another DC electric field cabinet is selected by the input cabinet selecting step and the return cabinet selecting step, respectively.

26. The DC electric field cabinets have electrodes with different areas in contact with the treatment liquid, 24. The substrate processing method according to claim 23, wherein the input cabinet selecting step selects one of the DC electric field cabinets based on the contamination level measured in the measuring step.

27. The DC electric field cabinets have different DC electric field intensities applied to the treatment liquid, 24. The substrate processing method according to claim 23, wherein the input cabinet selecting step selects one of the DC electric field cabinets based on the contamination level measured in the measuring step.

28. the plurality of DC electric field cabinets are connected in series so that the treatment liquid treated in one DC electric field cabinet is input into another DC electric field cabinet; 24. The substrate processing method according to claim 23, wherein the input cabinet selecting step selects one of the DC electric field cabinets based on the contamination level measured in the measuring step.

29. The substrate processing method according to any one of claims 19 to 21, further comprising a step of controlling the strength of the DC electric field applied to the processing liquid by the DC electric field cabinet based on the type of the processing liquid, the type of foreign matter in the processing liquid, or the degree of contamination measured in the measuring step.

30. the DC electric field cabinet includes a plurality of electrodes for applying a DC electric field to the treatment liquid, and a DC power supply for applying a DC voltage to the plurality of electrodes; 22. The substrate processing method according to claim 19, further comprising the step of controlling a DC voltage applied to the plurality of electrodes from the DC power supply based on the type of the processing liquid, the type of foreign matter in the processing liquid, or the degree of contamination measured in the measuring step.

31. the DC electric field cabinet includes a plurality of electrodes for applying a DC electric field to the processing solution; 22. The substrate processing method according to claim 19, further comprising an electrode arrangement changing step of changing an arrangement of the electrodes based on the type of the processing liquid, the type of foreign matter in the processing liquid, or the degree of contamination measured in the measuring step.

32. 32. The substrate processing method according to claim 31, wherein the electrode arrangement changing step changes the spacing between the plurality of electrodes.

33. 32. The substrate processing method according to claim 31, wherein the electrode position changing step changes the positions of the plurality of electrodes so that an area of ​​a portion of the plurality of electrodes immersed in the processing liquid changes.

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