Substrate Processing Apparatus and Substrate Processing Method

Abstract

The present invention relates to a substrate processing apparatus and a substrate processing method. The substrate processing apparatus of the present invention includes: a nozzle having a discharge port and discharging SPM from the discharge port toward a substrate; a mixing unit communicating with the discharge port; a sulfuric acid-containing liquid supply device that recovers a liquid supplied to the substrate held by the substrate holding unit and discharged from the substrate, manufactures a sulfuric acid-containing liquid based on the recovered liquid, and supplies the manufactured sulfuric acid-containing liquid to the mixing unit; and a control device. Moreover, the control device executes: a sulfuric acid-containing liquid manufacturing step of recovering SPM supplied to the substrate and discharged from the substrate to manufacture a sulfuric acid-containing liquid; and an SPM discharging step of generating SPM by supplying the manufactured sulfuric acid-containing liquid and hydrogen peroxide water to the mixing unit and mixing the sulfuric acid-containing liquid and hydrogen peroxide water in the mixing unit, and discharging the generated SPM from the discharge port.

Description

Technical Field

[0001] The present invention relates to a substrate processing apparatus and a substrate processing method. Examples of substrates to be processed include semiconductor wafers, substrates for liquid crystal display devices, substrates for FPDs (Flat Panel Displays) such as organic EL (electroluminescence) display devices, substrates for optical discs, substrates for magnetic discs, substrates for magneto-optical discs, substrates for photomasks, ceramic substrates, substrates for solar cells, and the like. Background Art

[0002] In the manufacturing steps of semiconductor devices or liquid crystal display devices, etc., a substrate processing apparatus for processing substrates such as semiconductor wafers or glass substrates for liquid crystal display devices is used.

[0003] In Patent Document 1 below, a single-wafer substrate processing apparatus for processing substrates one by one is disclosed. This substrate processing apparatus includes: a rotary chuck that rotates while holding the substrate horizontally; and a nozzle that sprays SPM (a mixed solution of sulfuric acid and hydrogen peroxide water) toward the substrate held by the rotary chuck. In Patent Document 1, a configuration is disclosed in which the SPM used for processing the substrate is recovered and the recovered SPM is reused for subsequent processing.

[0004] Background Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-024793 Summary of the Invention

[0007] [Problems to be Solved by the Invention]

[0008] In Patent Document 1, the SPM recovered from the processing chamber housing the rotary chuck is recovered into a recovery tank through a recovery pipeline. The SPM stored in this recovery tank is supplied to a circulation tank after removing foreign substances contained in the SPM through a filter. An SPM supply pipe extending toward the SPM nozzle is connected to the circulation tank. A pump is interposed in the middle part of this SPM supply pipe. In addition, in the middle part of the SPM supply pipe, a filter, a heater, and a spray valve are interposed on the downstream side of the pump. In the SPM supply pipe, an SPM circuit pipe is branched and connected between the heater and the spray valve. The front end of the SPM circuit pipe extends toward the circulation tank.

[0009] During the operation of the substrate processing apparatus, the pump and the temperature regulator are always driven. During the period when the ejection valve is closed, by opening the circuit valve, the SPM drawn from the circulation tank flows along the SPM supply pipe to the branch point of the SPM circuit pipe, and returns from this branch point to the circulation tank through the SPM circuit pipe. That is, during the period when SPM is not ejected from the SPM nozzle, SPM circulates along the circulation tank, the SPM supply pipe, and the SPM circuit pipe. By circulating SPM, the SPM whose temperature is adjusted to a fixed temperature is stored in the circulation tank. Moreover, when it is time to eject SPM from the SPM nozzle, the SPM whose temperature is adjusted to a fixed temperature is drawn from the circulation tank and supplied to the SPM nozzle through the SPM supply pipe. Then, the SPM ejected from the SPM nozzle is supplied to the substrate.

[0010] However, in Patent Document 1, when the recovery and reuse of SPM are repeated, the concentrations of sulfuric acid and hydrogen peroxide water contained in SPM each decrease to values unsuitable for reuse.

[0011] In particular, the concentration of hydrogen peroxide decreases significantly. That is, as the temperature of SPM becomes higher, the removal ability of SPM (the ability of SPM to remove the resist) improves. Therefore, it is desirable to use SPM at a high temperature. However, hydrogen peroxide is easily decomposed into water and oxygen at a high temperature state. Therefore, when the recovery and reuse of SPM are repeated, there is a concern that the concentration of hydrogen peroxide decreases to a value unsuitable for reuse relatively early.

[0012] In short, in the method described in Patent Document 1, due to the decrease in the concentrations of sulfuric acid and hydrogen peroxide water contained in SPM, the resist cannot be efficiently removed from the substrate.

[0013] Therefore, one object of the present invention is to provide a substrate processing apparatus and a substrate processing method capable of efficiently removing a resist from a substrate using SPM made from the recovered sulfuric acid-containing liquid.

[0014] [Means for Solving the Problem]

[0015] The present invention provides a substrate processing apparatus that removes a resist from a substrate using SPM which is a mixed liquid of sulfuric acid and hydrogen peroxide water, and includes: a substrate holding unit that holds a substrate; a nozzle having a discharge port and discharging SPM from the discharge port toward the substrate held by the substrate holding unit; a mixing unit that communicates with the discharge port; a sulfuric acid-containing liquid supply device that recovers a liquid supplied to the substrate held by the substrate holding unit and discharged from the substrate, produces a sulfuric acid-containing liquid based on the recovered liquid, and supplies the produced sulfuric acid-containing liquid to the mixing unit; a hydrogen peroxide water supply unit that supplies hydrogen peroxide water to the mixing unit; and a control device that controls the sulfuric acid-containing liquid supply device and the hydrogen peroxide water supply unit; the control device performs: a sulfuric acid-containing liquid production step of recovering the SPM supplied to the substrate and discharged from the substrate to produce a sulfuric acid-containing liquid; and an SPM discharge step of generating SPM by supplying the produced sulfuric acid-containing liquid and hydrogen peroxide water to the mixing unit and mixing the sulfuric acid-containing liquid and hydrogen peroxide water in the mixing unit, and discharging the generated SPM from the discharge port.

[0016] In the present specification, the sulfuric acid-containing liquid is a liquid containing sulfuric acid, and may contain components other than sulfuric acid, and is a liquid containing sulfuric acid at a ratio of half or more in terms of weight% concentration.

[0017] According to this configuration, based on the SPM discharged from and recovered from the substrate, a sulfuric acid-containing liquid is produced instead of the SPM itself. The produced sulfuric acid-containing liquid is reused as SPM by mixing with hydrogen peroxide water.

[0018] From the viewpoint of improving the removal ability of SPM, it is required that the sulfuric acid concentration of the produced sulfuric acid-containing liquid be within a specified concentration range. Moreover, from the same viewpoint, it is required that the temperature of the produced sulfuric acid-containing liquid be within a specified temperature range.

[0019] Focusing on the sulfuric acid contained in the recovered SPM, the sulfuric acid concentration and temperature of the sulfuric acid-containing liquid are adjusted in a form separated from hydrogen peroxide. Therefore, a sulfuric acid-containing liquid that satisfies both the required concentration range and temperature range can be produced well. Moreover, by mixing the produced sulfuric acid-containing liquid with hydrogen peroxide water, the resist can be efficiently removed from the substrate using the SPM produced based on the recovered sulfuric acid-containing liquid.

[0020] In one embodiment of the present invention, the sulfuric acid-containing liquid supply device includes a first liquid storage unit and a second liquid storage unit. The first liquid storage unit includes a first tank for storing the recovered liquid and a sulfuric acid replenishment unit for replenishing sulfuric acid to the first tank. The second liquid storage unit includes: a second tank for storing the liquid transported from the first tank; a first pipe having both ends connected to the second tank for circulating the liquid stored in the second tank; and a first heater for heating the liquid circulating along the second tank and the first pipe. The control device performs, in the step of forming the sulfuric acid-containing liquid: a first storage step of recovering the SPM discharged from the substrate and storing it as a sulfuric acid-containing liquid in the first tank; a sulfuric acid replenishment step of replenishing sulfuric acid to the first tank through the sulfuric acid replenishment unit; a second storage step of storing the sulfuric acid-containing liquid transported from the first tank in the second tank; and a first heating step of heating the sulfuric acid-containing liquid circulating along the second tank and the first pipe through the first heater. Further, the control device performs, in the SPM ejection step, a step of supplying the sulfuric acid-containing liquid circulating along the second tank and the first pipe to the mixing unit.

[0021] According to this configuration, in the first liquid storage unit, the SPM discharged and recovered from the substrate is stored as a sulfuric acid-containing liquid in the first tank. In addition, sulfuric acid from the sulfuric acid replenishment unit is replenished to the first tank. Thus, the sulfuric acid concentration of the sulfuric acid-containing liquid stored in the first tank can be adjusted to the required concentration range with good accuracy.

[0022] In addition, in the second liquid storage unit, the sulfuric acid-containing liquid transported from the first liquid storage unit circulates along the second tank and the first pipe. The sulfuric acid-containing liquid circulating along the second tank and the first pipe is heated by the first heater. Thus, the temperature of the sulfuric acid-containing liquid circulating along the second tank and the first pipe can be adjusted to the required temperature range with good accuracy.

[0023] The second liquid storage unit that specifically adjusts the temperature of the sulfuric acid-containing liquid is provided separately from the first liquid storage unit that can replenish sulfuric acid to the sulfuric acid-containing liquid (can adjust the sulfuric acid concentration of the sulfuric acid-containing liquid). Since the temperature of the replenished sulfuric acid is room temperature, if the sulfuric acid-containing liquid is adjusted in temperature while sulfuric acid is replenished in the liquid storage unit for adjusting the temperature of the sulfuric acid-containing liquid, the temperature of the sulfuric acid-containing liquid in the liquid storage unit is unstable. Since the second liquid storage unit that specifically adjusts the temperature of the sulfuric acid-containing liquid and the first liquid storage unit that can replenish sulfuric acid to the sulfuric acid-containing liquid are provided separately, the temperature of the sulfuric acid-containing liquid in the second liquid storage unit is stable. Thus, the sulfuric acid-containing liquid transported to the mixing unit can be adjusted to the desired temperature range.

[0024] In an embodiment of the present invention, the second liquid storage unit further includes a sulfuric acid concentration meter that measures the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second tank and the first pipe. Moreover, when the measured value obtained by the sulfuric acid concentration meter is less than a specified determination value, the control device executes the sulfuric acid replenishment step.

[0025] According to this configuration, since the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second tank and the first pipe is measured by the concentration meter, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second tank and the first pipe can be accurately obtained. Thereby, the sulfuric acid concentration of the sulfuric acid-containing liquid transported to the mixing unit can be adjusted to a desired concentration range with good accuracy.

[0026] In an embodiment of the present invention, the first liquid storage unit further includes: a second pipe whose both ends are connected to the first tank and through which the sulfuric acid-containing liquid stored in the first tank circulates; and a second heater that heats the sulfuric acid-containing liquid circulating along the first tank and the second pipe. In the sulfuric acid-containing liquid preparation step, the control device also executes a second heating step of heating the sulfuric acid-containing liquid circulating along the first tank and the second pipe by the second heater.

[0027] According to this configuration, in the first liquid storage unit, the sulfuric acid-containing liquid circulates along the first tank and the second pipe. The sulfuric acid-containing liquid circulating along the first tank and the second pipe is heated by the second heater. The sulfuric acid-containing liquid is heated by the second and first heaters in the first and second liquid storage units, respectively. Therefore, more heat can be imparted to the sulfuric acid-containing liquid. Thus, the sulfuric acid-containing liquid can be heated to a higher temperature in the second liquid storage unit.

[0028] In addition, since both the first and second heaters are used to heat the sulfuric acid-containing liquid, the burden imposed on one heater (i.e., the first heater) can be reduced.

[0029] In an embodiment of the present invention, the first liquid storage unit further includes a second pipe whose both ends are connected to the first tank and through which the sulfuric acid-containing liquid stored in the first tank circulates. Moreover, no unit for heating the sulfuric acid-containing liquid circulating along the first tank and the second pipe is provided in the first liquid storage unit.

[0030] According to this configuration, no unit for heating the sulfuric acid-containing liquid circulating along the first tank and the second pipe is provided in the first liquid storage unit. That is, the sulfuric acid-containing liquid is not heated in the first liquid storage unit. Therefore, the sulfuric acid-containing liquid circulating along the first tank and the second pipe has a relatively low temperature.

[0031] In an embodiment of the present invention, the first liquid storage unit further includes a filter interposed in the second pipe that captures foreign substances contained in the sulfuric acid-containing liquid flowing through the second pipe.

[0032] According to this configuration, the sulfuric acid-containing liquid flowing through the second pipe is captured by the filter. The temperature of the sulfuric acid-containing liquid passing through the filter is relatively low.

[0033] Assuming that a high-temperature sulfuric acid-containing liquid flows through the first tank and the second pipe, there is a concern that as the high-temperature sulfuric acid-containing liquid continues to flow through the filter, the filter expands, and thus the diameter of each hole of the filter increases. If the diameter of each hole of the filter increases, the diameter of the foreign matter that the filter can capture becomes larger. Therefore, there is a concern that the filtering performance of the filter deteriorates and the foreign matter contained in the sulfuric acid-containing liquid cannot be captured well in the first liquid storage section.

[0034] In this configuration, since the temperature of the sulfuric acid-containing liquid passing through the filter is relatively low, it is possible to suppress a decrease in the filtering performance of the filter. Therefore, the foreign matter contained in the sulfuric acid-containing liquid can be captured well in the first liquid storage section. As a result, a clean sulfuric acid-containing liquid can be supplied to the mixing section.

[0035] In one embodiment of the present invention, the sulfuric acid-containing liquid supply device further includes a third liquid storage section. The third liquid storage section includes: a third tank that stores the liquid transported from the first tank; a third pipe that is connected at both ends to the third tank and circulates the liquid stored in the third tank; and a second heater that heats the liquid circulating through the third tank and the third pipe. The control device further executes, in the sulfuric acid-containing liquid production step: a third storage step of storing the sulfuric acid-containing liquid transported from the first tank in the third tank; and a second heating step of heating the sulfuric acid-containing liquid circulating through the third tank and the third pipe by the second heater. Moreover, the control device further executes a step of transporting the sulfuric acid-containing liquid circulating through the third tank and the third pipe to the second tank in the SPM ejection step.

[0036] According to this configuration, the sulfuric acid-containing liquid transported from the first liquid storage section circulates through the third tank and the third pipe. The sulfuric acid-containing liquid circulating through the third tank and the third pipe is heated by the second heater. The sulfuric acid-containing liquid is heated by the second and first heaters in the third and second liquid storage sections, respectively. More heat can be imparted to the sulfuric acid-containing liquid. Therefore, the sulfuric acid-containing liquid can be heated to a higher temperature in the second liquid storage section.

[0037] In addition, since both the first and second heaters are used to heat the sulfuric acid-containing liquid, the burden imposed on the first heater can be reduced.

[0038] In one embodiment of the present invention, the first liquid storage unit further includes a cooler for cooling the sulfuric acid-containing liquid circulating along the first tank and the second pipe. In the sulfuric acid-containing liquid preparation step, the control device further executes a cooling step of cooling the sulfuric acid-containing liquid circulating along the first tank and the second pipe by means of the cooler.

[0039] According to this configuration, the sulfuric acid-containing liquid circulating along the first tank and the second pipe can be cooled by the cooler. Therefore, the temperature of the sulfuric acid-containing liquid circulating along the first tank and the second pipe can be reduced to room temperature or below room temperature.

[0040] In this case, it is preferable that the first liquid storage unit further includes the filter.

[0041] According to this configuration, since the temperature of the sulfuric acid-containing liquid passing through the filter can be reduced to room temperature or below room temperature, the reduction of the filtration performance can be more effectively suppressed. Therefore, foreign matters contained in the sulfuric acid-containing liquid can be better captured in the first liquid storage unit. Thereby, a cleaner sulfuric acid-containing liquid can be supplied to the mixing unit.

[0042] In one embodiment of the present invention, the sulfuric acid-containing liquid circulating along the first tank and the second pipe is cooled only by natural cooling.

[0043] According to this configuration, the cost is not increased and the sulfuric acid-containing liquid can be cooled.

[0044] In one embodiment of the present invention, the heating temperature of the first heater, i.e., the first heating temperature, is higher than the heating temperature of the second heater, i.e., the second heating temperature.

[0045] According to this configuration, the sulfuric acid-containing liquid after being heated to the second heating temperature in the first liquid storage unit (the third liquid storage unit) is supplied to the second liquid storage unit. Moreover, in the second liquid storage unit, the sulfuric acid-containing liquid is heated and raised to the first heating temperature. That is to say, the sulfuric acid-containing liquid is heated step by step. Therefore, the sulfuric acid-containing liquid can be raised to a higher temperature in the second liquid storage unit. Thereby, even when the temperature (the first heating temperature) of the sulfuric acid-containing liquid to be transported to the mixing unit is set to an extremely high temperature, such a high-temperature sulfuric acid-containing liquid can be prepared well.

[0046] In one embodiment of the present invention, the substrate processing apparatus further includes: a sulfuric acid-containing liquid supply pipe connecting the second tank or the first pipe to the mixing unit; and a third heater for heating the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid supply pipe. In the sulfuric acid-containing liquid preparation step, the control device further executes a third heating step of heating the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid supply pipe by means of the third heater.

[0047] According to this configuration, the sulfuric acid-containing liquid circulating along the second tank and the first pipe is guided to the sulfuric acid-containing liquid supply pipe. Moreover, the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid supply pipe is heated by the third heater. By heating with the third heater, the sulfuric acid-containing liquid can be further heated compared to when it circulates along the second tank and the first pipe.

[0048] In one embodiment of the present invention, the substrate processing apparatus further includes: a mixing ratio changing unit that changes the ratio of the sulfuric acid-containing liquid to hydrogen peroxide water in the mixing unit; a recovery pipe that recovers and transports the liquid supplied to and discharged from the substrate held by the substrate holding unit to the sulfuric acid-containing liquid supply device; a drain pipe into which the liquid supplied to and discharged from the substrate held by the substrate holding unit flows; and a switching unit that switches the pipe into which the liquid discharged from the substrate held by the substrate holding unit flows between the drain pipe and the recovery pipe. Moreover, the control device also executes: a first SPM supply step of mixing the sulfuric acid-containing liquid and hydrogen peroxide water at a first mixing ratio representing the ratio of the sulfuric acid-containing liquid to hydrogen peroxide water by controlling the mixing ratio changing unit to prepare a first SPM, and supplying the prepared first SPM to the substrate held by the substrate holding unit; a second SPM supply step of mixing the sulfuric acid-containing liquid and hydrogen peroxide water at a second mixing ratio representing the ratio of the sulfuric acid-containing liquid to hydrogen peroxide water and greater than the first mixing ratio by controlling the mixing ratio changing unit to prepare a second SPM, and supplying the prepared second SPM to the substrate held by the substrate holding unit after stopping the supply of the first SPM in the first SPM supply step; a draining step of causing the first SPM supplied to and discharged from the substrate in the first SPM supply step to flow into the drain pipe by controlling the switching unit; and a recovery step of causing the second SPM supplied to and discharged from the substrate in the second SPM supply step to flow into the recovery pipe by controlling the switching unit.

[0049] According to this configuration, when preparing the first SPM, the sulfuric acid-containing liquid and hydrogen peroxide water are mixed at the first mixing ratio. When preparing the second SPM, the sulfuric acid-containing liquid and hydrogen peroxide water are mixed at the second mixing ratio. Both the first mixing ratio and the second mixing ratio represent the ratio of the volume of the sulfuric acid-containing liquid before mixing to the volume of hydrogen peroxide water before mixing. The first mixing ratio is less than the second mixing ratio. Therefore, the hydrogen peroxide concentration contained in the first SPM is higher than the hydrogen peroxide concentration contained in the second SPM.

[0050] Since the hydrogen peroxide concentration is relatively high, the first SPM has a higher removal ability than the second SPM. Therefore, the resist can be efficiently removed from the substrate. Moreover, after supplying the first SPM to the substrate, the second SPM is supplied to the substrate. Although the second SPM has a lower removal ability than the first SPM, since almost all the resist is removed from the substrate by supplying the first SPM, only the relatively easily removable resist remains on the substrate. Therefore, the second SPM with a lower removal ability can also surely remove the resist from the substrate.

[0051] The first SPM supplied to and discharged from the substrate flows into the drain pipe instead of the recovery pipe. The hydrogen peroxide concentration in the first SPM discharged from the substrate is relatively high, and the sulfuric acid concentration is relatively low. Moreover, the first SPM discharged from the substrate contains a large amount of contaminants (carbides of the resist, etc.) generated by the reaction of the first SPM with the resist. Therefore, the first SPM discharged from the substrate is not suitable for recovery.

[0052] On the other hand, the sulfuric acid concentration in the second SPM discharged from the substrate is relatively high. Furthermore, the amount of contaminants contained in the second SPM discharged from the substrate is less than the amount of contaminants contained in the first SPM discharged from the substrate. Therefore, the second SPM with a relatively high sulfuric acid concentration and a small amount of contaminants is guided to the recovery pipe to form a sulfuric acid-containing liquid. The formed sulfuric acid-containing liquid is mixed with hydrogen peroxide water. Thus, the sulfuric acid contained in the sulfuric acid-containing liquid reacts with hydrogen peroxide to form a new SPM. Therefore, the amount of SPM discarded can be reduced.

[0053] In this way, when the sulfuric acid concentration, that is, the ratio of the volume of sulfuric acid before mixing to the volumes of sulfuric acid and hydrogen peroxide water before mixing is large, since the SPM is recovered, an SPM with a relatively high sulfuric acid concentration can be recovered. Furthermore, instead of maintaining a large sulfuric acid concentration state, an SPM with a high hydrogen peroxide concentration and sufficient removal ability is supplied to the substrate before starting to recover the SPM. Therefore, the resist can be efficiently removed from the substrate. Therefore, the resist can be efficiently removed from the substrate, and an SPM with a relatively high sulfuric acid concentration can be recovered.

[0054] In an embodiment of the present invention, the substrate processing apparatus further includes: a first shield connected to the drain pipe and surrounding the substrate held by the substrate holding unit; and a second shield connected to the recovery pipe and surrounding the substrate held by the substrate holding unit. The switching unit includes a shield switching unit that switches the states of the first shield and the second shield between a first state in which the first shield receives the liquid discharged from the substrate and a second state in which the second shield receives the liquid discharged from the substrate. Moreover, the control device also executes: a first SPM capture step of causing the first shield to receive the first SPM discharged from the substrate in the first SPM supply step by controlling the shield switching unit; and a second SPM capture step of causing the second shield to receive the second SPM discharged from the substrate in the second SPM supply step by controlling the shield switching unit.

[0055] According to this configuration, the first SPM discharged from the substrate is received by the first shield surrounding the substrate. The second SPM discharged from the substrate is received by the second shield surrounding the substrate. The first SPM received by the first shield flows into the drain pipe connected to the first shield. The second SPM received by the second shield flows into the recovery pipe connected to the second shield.

[0056] The first SPM discharged from the substrate contains a large amount of contaminants. Therefore, there is a case where contaminants remain on the inner wall of the first shield after the first shield receives the first SPM. When the second SPM discharged from the substrate is received and recovered by the first shield, there is a case where the contaminants attached to the first shield are mixed into the second SPM. Therefore, by causing the second shield different from the first shield to receive the second SPM, the amount of contaminants contained in the recovered SPM can be reduced.

[0057] The present invention provides a substrate processing method performed in a substrate processing apparatus including a nozzle and a mixing unit. The nozzle sprays an SPM, which is a mixed solution of sulfuric acid and hydrogen peroxide water, from a spray outlet toward the substrate held by the substrate holding unit. The mixing unit communicates with the spray outlet. The substrate processing method includes: a sulfuric acid-containing solution preparation step of recovering the SPM supplied to the substrate held by the substrate holding unit and at least partially covered with a resist and discharged from the substrate to prepare a sulfuric acid-containing solution; and an SPM spraying step of supplying the prepared sulfuric acid-containing solution and hydrogen peroxide water to the mixing unit, thereby mixing the sulfuric acid-containing solution and hydrogen peroxide water in the mixing unit to generate an SPM and spraying the generated SPM from the spray outlet.

[0058] According to this method, a sulfuric acid-containing solution is prepared based on the SPM discharged from and recovered from the substrate instead of the SPM itself. The prepared sulfuric acid-containing solution is reused as an SPM by mixing with hydrogen peroxide water.

[0059] From the viewpoint of improving the removal ability of SPM, it is required that the sulfuric acid concentration of the produced sulfuric acid-containing liquid be within a specified concentration range. Also, from the same viewpoint, it is required that the temperature of the produced sulfuric acid-containing liquid be within a specified temperature range.

[0060] Focusing on the sulfuric acid contained in the recovered SPM, the sulfuric acid concentration and temperature of the sulfuric acid-containing liquid are adjusted in a form separated from hydrogen peroxide. Therefore, a sulfuric acid-containing liquid that satisfies both the required concentration range and temperature range can be well produced. Moreover, by mixing the produced sulfuric acid-containing liquid with hydrogen peroxide water, the resist can be efficiently removed from the substrate using the SPM made from the recovered sulfuric acid-containing liquid.

[0061] In one embodiment of the present invention, the step of producing the sulfuric acid-containing liquid includes the following steps: recovering the SPM discharged from the substrate and storing it as a sulfuric acid-containing liquid in a first tank of a first liquid storage unit; a sulfuric acid supplement step of supplementing sulfuric acid to the first tank; storing the sulfuric acid-containing liquid conveyed from the first tank in a second tank of a second liquid storage unit different from the first tank; and a heating step of heating the sulfuric acid-containing liquid circulated along the second tank and a first pipe connected to both ends of the second tank by a first heater of the second liquid storage unit. Moreover, the step of ejecting SPM includes a step of supplying the sulfuric acid-containing liquid circulated along the second tank and the first pipe to the mixing unit.

[0062] According to this method, in the first liquid storage unit, the SPM discharged from the substrate and recovered is stored as a sulfuric acid-containing liquid in the first tank. In addition, sulfuric acid from a sulfuric acid supply unit is supplemented to the first tank. Thereby, the sulfuric acid concentration of the sulfuric acid-containing liquid stored in the first tank can be accurately adjusted to the required concentration range.

[0063] In addition, in the second liquid storage unit, the sulfuric acid-containing liquid conveyed from the first liquid storage unit circulates along the second tank and the first pipe. The sulfuric acid-containing liquid circulated along the second tank and the first pipe is heated by the first heater. Thereby, the temperature of the sulfuric acid-containing liquid circulated along the second tank and the first pipe can be accurately adjusted to the required temperature range.

[0064] The second liquid storage section that specifically adjusts the temperature of the sulfuric acid-containing liquid can be separately provided from the first liquid storage section that can supplement sulfuric acid to the sulfuric acid-containing liquid (can adjust the sulfuric acid concentration of the sulfuric acid-containing liquid). Since the temperature of the supplemented sulfuric acid is room temperature, if the sulfuric acid-containing liquid is temperature-adjusted while supplementing sulfuric acid in the liquid storage section used for temperature-adjusting the sulfuric acid-containing liquid, the temperature of the sulfuric acid-containing liquid in the liquid storage section is unstable. Since the second liquid storage section that specifically adjusts the temperature of the sulfuric acid-containing liquid and the first liquid storage section that can supplement sulfuric acid to the sulfuric acid-containing liquid are separately provided, the temperature of the sulfuric acid-containing liquid in the second liquid storage section is stable. Thus, the sulfuric acid-containing liquid delivered to the mixing section can be adjusted to a desired temperature range.

[0065] In an embodiment of the present invention, the substrate processing method further includes: a first SPM supply step of mixing the sulfuric acid-containing liquid and hydrogen peroxide water at a first mixing ratio representing the ratio of the sulfuric acid-containing liquid to hydrogen peroxide water by changing the ratio of the sulfuric acid-containing liquid to hydrogen peroxide water in the mixing section to prepare a first SPM, and supplying the prepared first SPM to the substrate held by the substrate holding unit; a second SPM supply step of mixing the sulfuric acid-containing liquid and hydrogen peroxide water at a second mixing ratio representing the ratio of the sulfuric acid-containing liquid to hydrogen peroxide water and greater than the first mixing ratio by changing the ratio of the sulfuric acid-containing liquid to hydrogen peroxide water in the mixing section to prepare a second SPM, and supplying the prepared second SPM to the substrate held by the substrate holding unit after stopping the supply of the first SPM in the first SPM supply step; a drainage step of flowing the first SPM supplied to the substrate and discharged from the substrate in the first SPM supply step into a drainage pipe different from the recovery pipe, the recovery pipe being used to recover and transport the liquid supplied to the substrate held by the substrate holding unit and discharged from the substrate to the sulfuric acid-containing liquid supply device; and a recovery step of flowing the second SPM supplied to the substrate and discharged from the substrate in the second SPM supply step into the recovery pipe.

[0066] According to this method, when preparing the first SPM, the sulfuric acid-containing liquid and hydrogen peroxide water are mixed at the first mixing ratio. When preparing the second SPM, the sulfuric acid-containing liquid and hydrogen peroxide water are mixed at the second mixing ratio. Both the first mixing ratio and the second mixing ratio represent the ratio of the volume of the sulfuric acid-containing liquid before mixing to the volume of hydrogen peroxide water before mixing. The first mixing ratio is less than the second mixing ratio. Therefore, the hydrogen peroxide concentration contained in the first SPM is higher than the hydrogen peroxide concentration contained in the second SPM.

[0067] Since the hydrogen peroxide concentration is relatively high, the first SPM has a higher removal ability than the second SPM. Therefore, the resist can be efficiently removed from the substrate. Moreover, after the first SPM is supplied to the substrate, the second SPM is supplied to the substrate. Although the removal ability of the second SPM is worse than that of the first SPM, since almost all of the resist is removed from the substrate by supplying the first SPM, only the relatively easily removable resist remains on the substrate. Therefore, the second SPM with a relatively poor removal ability can also surely remove the resist from the substrate.

[0068] The first SPM supplied to and discharged from the substrate flows into the drain pipe rather than the recovery pipe. The hydrogen peroxide concentration in the first SPM discharged from the substrate is relatively high, and the sulfuric acid concentration is relatively low. Moreover, the first SPM discharged from the substrate contains a large amount of contaminants (carbides of the resist, etc.) generated by the reaction of the first SPM with the resist. Therefore, the first SPM discharged from the substrate is not suitable for recovery.

[0069] On the other hand, the sulfuric acid concentration in the second SPM discharged from the substrate is relatively high. Furthermore, the amount of contaminants contained in the second SPM discharged from the substrate is less than the amount of contaminants contained in the first SPM discharged from the substrate. Therefore, the second SPM with a relatively high sulfuric acid concentration and a small amount of contaminants is guided to the recovery pipe to form a sulfuric acid-containing liquid. The formed sulfuric acid-containing liquid is mixed with hydrogen peroxide water. Thus, the sulfuric acid contained in the sulfuric acid-containing liquid reacts with hydrogen peroxide to form a new SPM. Therefore, the amount of SPM discarded can be reduced.

[0070] In this way, when the sulfuric acid concentration, that is, the ratio of the volume of sulfuric acid before mixing to the volumes of sulfuric acid and hydrogen peroxide water before mixing, is large, since the SPM is recovered, an SPM with a relatively high sulfuric acid concentration can be recovered. Furthermore, instead of maintaining a large sulfuric acid concentration state, an SPM with a high hydrogen peroxide concentration and sufficient removal ability is supplied to the substrate before starting to recover the SPM. Therefore, the resist can be efficiently removed from the substrate. Thus, the resist can be efficiently removed from the substrate, and an SPM with a relatively high sulfuric acid concentration can be recovered.

[0071] In an embodiment of the present invention, the substrate processing method further includes: a first SPM capturing step of causing a first shield surrounding the substrate and connected to the drain pipe to receive the first SPM discharged from the substrate in the first SPM supply step; and a second SPM capturing step of causing a second shield surrounding the substrate and connected to the recovery pipe to receive the second SPM discharged from the substrate in the second SPM supply step.

[0072] According to this method, the first SPM discharged from the substrate is received by the first shield surrounding the substrate. The second SPM discharged from the substrate is received by the second shield surrounding the substrate. The first SPM received by the first shield flows into the drain pipe connected to the first shield. The second SPM received by the second shield flows into the recovery pipe connected to the second shield.

[0073] The first SPM discharged from the substrate contains a large amount of contaminants. Therefore, there is a case where contaminants remain on the inner wall of the first shield after the first shield receives the first SPM. When the second SPM discharged from the substrate is received and recovered by the first shield, there is a case where the contaminants attached to the first shield are mixed into the second SPM. Therefore, by using a second shield different from the first shield to receive the second SPM, the amount of contaminants contained in the recovered SPM can be reduced.

[0074] The above-described and other objects, features, and effects of the present invention will become apparent from the description of the embodiments described below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 is a schematic view obtained by observing the substrate processing apparatus according to the first embodiment of the present invention from above.

[0076] Figure 2 is a view obtained by observing horizontally Figure 1 the first sulfuric acid-containing liquid supply device and the device main body shown in the figure.

[0077] Figure 3 is a view obtained by magnifying the configuration of the third capture filter shown in Figure 2 and showing a cross-sectional view.

[0078] Figure 4 is a view obtained by observing horizontally Figure 1 the second sulfuric acid-containing liquid supply device and the device main body shown in the figure.

[0079] Figure 5 is used to illustrate Figure 1 the configuration example of the processing unit shown in the figure and showing a schematic cross-sectional view.

[0080] Figure 6 is a block diagram for explaining the electrical configuration of the substrate processing apparatus.

[0081] Figure 7 is a flowchart for explaining an example of the substrate processing performed by the substrate processing apparatus.

[0082] Figure 8 is a view showing the SPM step ( Figure 7Timing chart of the transition of the mixing ratio of the sulfuric acid-containing liquid and hydrogen peroxide water in S3) and the operations of the first shield and the second shield, etc.

[0083] Figure 9 It is a flowchart showing the process of mixing a sulfuric acid-containing liquid and hydrogen peroxide water to prepare SPM and supplying the recovered SPM from the substrate to another substrate.

[0084] Figure 10 It is a graph showing the transition of the sulfuric acid concentration of the recovered sulfuric acid-containing liquid.

[0085] Figure 11 It is a view obtained by observing the first sulfuric acid-containing liquid supply device of the second embodiment of the present invention in the horizontal direction.

[0086] Figure 12 It is a view obtained by observing the first sulfuric acid-containing liquid supply device of the third embodiment of the present invention in the horizontal direction.

[0087] Figure 13 It is a view for explaining the change caused by thermal influence in the filtration performance of the capture filter. Detailed implementation mode

[0088] Figure 1 It is a schematic view obtained by observing the substrate processing apparatus 1 of the first embodiment of the present invention from above.

[0089] The substrate processing apparatus 1 is a single-wafer type apparatus that processes circular plate-shaped substrates W such as semiconductor wafers one by one. The substrate processing apparatus 1 includes an apparatus main body 2 disposed in a clean room, a transfer unit 3 coupled to the apparatus main body 2, a processing liquid supply device, and a control device 4 that controls the substrate processing apparatus 1.

[0090] The transfer unit 3 includes a plurality of loading ports LP that respectively hold and accommodate a plurality of carriers C for the substrate W and a transfer robot IR for transferring the substrate W with respect to each carrier C.

[0091] The apparatus main body 2 includes a transfer chamber 5 and a plurality of processing units 6 that process the substrate W transferred from the plurality of loading ports LP using a processing fluid such as a processing liquid or a processing gas. The plurality of processing units 6 form six towers respectively disposed at six horizontally separated positions. Each tower includes a plurality of (for example, three) processing units 6 stacked vertically. Three towers are disposed on each side of the transfer chamber 5. The processing units 6 are disposed in the outer wall 7 of the apparatus main body 2, that is, surrounded by the outer wall 7.

[0092] In addition to the transfer robot IR, the substrate processing apparatus 1 includes a first substrate transfer robot CR1 and a second substrate transfer robot CR2 as transfer robots. The first substrate transfer robot CR1 and the second substrate transfer robot CR2 are arranged in the transfer chamber 5. The transfer robot IR transfers the substrate W between the load port LP and the first substrate transfer robot CR1. The transfer robot IR includes a hand for supporting the substrate W. The first substrate transfer robot CR1 transfers the substrate W between the transfer robot IR and the processing units 6 included in the two towers on the load port LP side, and also transfers the substrate W between the transfer robot IR and the second substrate transfer robot CR2. The second substrate transfer robot CR2 transfers the substrate W between the transfer robot IR and the processing units 6 included in the four towers on the side opposite to the load port LP side. The first substrate transfer robot CR1 and the second substrate transfer robot CR2 include hands for supporting the substrate W.

[0093] The processing liquid supply device supplies a processing liquid (sulfuric acid-containing liquid (etching liquid or cleaning liquid)) to the processing unit 6. The processing liquid supply device includes a sulfuric acid-containing liquid supply device 8 that supplies a sulfuric acid-containing liquid containing sulfuric acid to the processing unit 6. The sulfuric acid-containing liquid supply device 8 recovers the sulfuric acid-containing liquid discharged from the processing unit 6 and adjusts it as a sulfuric acid-containing liquid, and supplies the adjusted sulfuric acid-containing liquid to the processing unit 6. The sulfuric acid-containing liquid supply device 8 includes a first sulfuric acid-containing liquid supply device 9 arranged outside the clean room and a second sulfuric acid-containing liquid supply device 10 arranged outside the outer wall 7 in the clean room.

[0094] In this embodiment, the substrate processing apparatus 1 is provided with two first sulfuric acid-containing liquid supply devices 9. The two first sulfuric acid-containing liquid supply devices 9 are arranged in the space downstairs of the clean room called the Sub-Fab. Each first sulfuric acid-containing liquid supply device 9 corresponds to three towers arranged on one side of the transfer chamber 5. The SPM discharged from the processing units 6 included in the corresponding three towers is supplied to each first sulfuric acid-containing liquid supply device 9. The first sulfuric acid-containing liquid supply device 9 includes a first liquid storage part 11 that recovers the SPM discharged from the processing unit 6, stores it as a sulfuric acid-containing liquid, and adjusts it to a specified state.

[0095] In the first sulfuric acid-containing liquid supply device 9, the second sulfuric acid-containing liquid supply devices 10 are provided in one-to-one correspondence. That is, the substrate processing apparatus 1 is provided with two second sulfuric acid-containing liquid supply devices 10.

[0096] To the second sulfuric acid-containing liquid supply device 10, a sulfuric acid-containing liquid is transported from the corresponding first sulfuric acid-containing liquid supply device 9. The second sulfuric acid-containing liquid supply device 10 includes a second liquid storage unit 12 that stores the sulfuric acid-containing liquid transported from the first liquid storage unit 11 and adjusts it to a specified sulfuric acid concentration and temperature. The sulfuric acid-containing liquid adjusted by the second liquid storage unit 12 is supplied to the SPM nozzle (nozzle) 13 of the processing unit 6 (refer to Figure 2 and Figure 4 ). Hydrogen peroxide water is supplied to the SPM nozzle 13 from the hydrogen peroxide water supply unit 122 (refer to Figure 4 ). The sulfuric acid-containing liquid and the hydrogen peroxide water supplied to the SPM nozzle 13 are mixed inside the SPM nozzle 13 (mixing section), thereby generating SPM. Moreover, the SPM is ejected from the ejection port 13a formed at the lower part of the SPM nozzle 13 (refer to Figure 5 ). The ejection port 13a communicates with the inside of the SPM nozzle 13. Also, in the processing unit 6, the SPM ejected from the ejection port 13a is supplied to the substrate W. Thereby, the resist is removed from the substrate W.

[0097] In the sulfuric acid-containing liquid supply device 8, based on the SPM discharged and recovered from the substrate W, a sulfuric acid-containing liquid is produced instead of the SPM itself (sulfuric acid-containing liquid production step). The produced sulfuric acid-containing liquid is reused as SPM by mixing it with hydrogen peroxide water.

[0098] From the viewpoint of improving the removal ability of the SPM, it is required that the sulfuric acid concentration of the produced sulfuric acid-containing liquid be within a specified concentration range. Also, from the same viewpoint, it is required that the temperature of the produced sulfuric acid-containing liquid be within a specified temperature range.

[0099] In the sulfuric acid-containing liquid supply device 8, focusing on the sulfuric acid contained in the recovered SPM, the sulfuric acid concentration and temperature of the sulfuric acid-containing liquid are adjusted in a form separated from hydrogen peroxide. Therefore, a sulfuric acid-containing liquid that satisfies both the required concentration range and temperature range can be produced well.

[0100] Then, the produced sulfuric acid-containing liquid is mixed with hydrogen peroxide water in the SPM nozzle 13 to generate SPM, and the generated SPM is ejected from the SPM nozzle 13 and supplied to the substrate W (SPM ejection step). Thereby, the resist can be efficiently removed from the substrate W using the SPM produced from the recovered sulfuric acid-containing liquid.

[0101] Figure 2 is a view obtained by observing the first sulfuric acid-containing liquid supply device 9 and the device main body 2 shown in Figure 1 from the horizontal direction. Figure 3 is a cross-sectional view showing an enlarged configuration of the third capture filter 37 shown in Figure 2 .

[0102] As shown Figure 2 in FIG. Figure 2 , the first liquid storage section 11 included in the first sulfuric acid-containing liquid supply device 9 includes a reclaim tank 21, a first circulation tank (first tank) 22, a first circulation pipe (second pipe) 23, a first circulation heater (second heater) 24, and a sulfuric acid replenishing unit 25.

[0103] As shown Figure 2 in FIG. Figure 2 , the reclaim tank 21 stores the SPM recovered from a total of nine processing units 6 included in the corresponding three towers as a sulfuric acid-containing liquid. Specifically, the downstream end of a reclaim lead-out pipe 26 connected to the following reclaim pipe 156 is connected to the reclaim tank 21. The SPM recovered into the processing cups 111 of the respective processing units 6 is guided to the reclaim tank 21 through the reclaim pipe 156 and the reclaim lead-out pipe 26, and is stored in the reclaim tank 21 as a sulfuric acid-containing liquid. A first capture filter 27 is interposed in the middle of the reclaim lead-out pipe 26, and the first capture filter 27 captures and removes foreign matters in the SPM flowing through the reclaim lead-out pipe 26. The first capture filter 27 is a filter for capturing relatively large foreign matters included in the SPM. The configuration of the first capture filter 27 is the same as that of the third capture filter 37 described below. The diameter of the following holes 71 (refer to Figure 3 ) is larger than that of the first capture filter 27 compared with the second capture filter 30 or the third capture filter (filter) 37 described below. The reclaim lead-out pipe 26 extends vertically, and the SPM is pressed against the first capture filter 27 by the self-weight of the SPM flowing through the reclaim lead-out pipe 26. Thereby, relatively large foreign matters are captured by the first capture filter 27. Then, the SPM from which the relatively large foreign matters have been removed is stored in the reclaim tank 21 as a sulfuric acid-containing liquid.

[0104] The downstream ends of three reclaim lead-out pipes 26 corresponding to the three towers are respectively connected to the reclaim tank 21. In Figure 2 FIG. Figure 2 , only one tower is shown in detail, and for the other two towers, only "other towers" are described, and the detailed description is omitted.

[0105] As shown Figure 2 in FIG. Figure 2 , the upstream end of a transfer pipe 28 whose downstream end is connected to the first circulation tank 22 is connected to the reclaim tank 21. In the transfer pipe 28, a first liquid feeding device 29 such as a pump for sucking the sulfuric acid-containing liquid in the reclaim tank 21, and a second capture filter 30 for capturing and removing relatively small foreign matters included in the sulfuric acid-containing liquid flowing through the transfer pipe 28 are interposed. The configuration of the second capture filter 30 is the same as that of the third capture filter 37 described below. The second capture filter 30 has the same diameter of the holes 71 (refer to Figure 3 ) as the third capture filter 37. As shown Figure 2As shown, the first liquid feeding device 29 and the second capture filter 30 are arranged in sequence from the side of the recovery tank 21. Therefore, by the suction force of the first liquid feeding device 29, the sulfuric acid-containing liquid flowing along the transfer pipe 28 is pressed against the second capture filter 30. Thereby, foreign matters can be captured by the second capture filter 30. The sulfuric acid-containing liquid is transported from the recovery tank 21 to the first circulation tank 22 via the transfer pipe 28, and the sulfuric acid-containing liquid is stored in the first circulation tank 22 (the first storage step).

[0106] As Figure 2 shown, a first liquid guiding pipe 31 extending toward the second sulfuric acid-containing liquid supply device 10 (the second liquid storage part 12) is connected to the first circulation tank 22. In the middle part of the first liquid guiding pipe 31, a second liquid feeding device 32 such as a pump for sucking the sulfuric acid-containing liquid in the first circulation tank 22 is interposed. In the middle part of the first liquid guiding pipe 31, a third capture filter 37 and an on-off valve 38 are interposed on the downstream side of the second liquid feeding device 32. The third capture filter 37 is a filter for capturing and removing relatively small foreign matters contained in the sulfuric acid-containing liquid flowing along the first liquid guiding pipe 31. The third capture filter 37 removes foreign matters not completely removed by the second capture filter 30.

[0107] As Figure 3 shown, the third capture filter 37 is, for example, in a cylindrical shape with a closed downstream end side, and is, for example, a standard closed-type filter. A plurality of holes 71 are formed in the entire area of the third capture filter 37, and the plurality of holes 71 penetrate the third capture filter 37 in the thickness direction of the third capture filter 37. The holes 71 of the third capture filter 37 are, for example, square when viewed from the thickness direction of the third capture filter 37, but when viewed from this direction, they may also be polygons other than regular polygons, circles, or ellipses.

[0108] As Figure 3 shown, the third capture filter 37 is detachably mounted in a housing 72 that holds the third capture filter 37 inside. The housing 72 includes: an inflow part 73 connected to the downstream end of a pipe (the first liquid guiding pipe 31) on the upstream side of the third capture filter 37; and an outflow part 74 connected to the upstream end of a pipe (the first liquid guiding pipe 31) on the downstream side of the third capture filter 37.

[0109] As Figure 3As shown, the interior of the housing 72 is divided by the third capture filter 37 into an upstream-side space B1 of the third capture filter 37 through which the sulfuric acid-containing liquid to be filtered flows, and a downstream-side space B2 of the third capture filter 37 through which the filtered sulfuric acid-containing liquid flows. By the suction force of the second liquid-feeding device 32, the sulfuric acid-containing liquid flowing along the first liquid-guiding pipe 31 is pressed against the third capture filter 37, and the sulfuric acid-containing liquid flows from the upstream-side space B1 to the downstream-side space B2 and passes through the holes 71 of the third capture filter 37. Thus, the sulfuric acid-containing liquid is filtered by the third capture filter 37. Foreign matters contained in the sulfuric acid-containing liquid present in the upstream-side space B1 are captured in the holes 71 by being adsorbed to the wall surface of the third capture filter 37 that divides the holes 71. Thus, the foreign matters are removed by the third capture filter 37.

[0110] As Figure 2 shown, the on-off valve 38 is a valve for controlling the flow and stop of the sulfuric acid-containing liquid in the first liquid-guiding pipe 31.

[0111] As Figure 2 shown, in the first liquid-guiding pipe 31, a reflux pipe 40 is branched and connected between the on-off valve 38 and the third capture filter 37. The downstream end of the reflux pipe 40 extends toward the first circulation tank 22. A reflux valve 41 is interposed in the middle part of the reflux pipe 40. The upstream-side part of the branch position 42 of the reflux pipe 40 in the first liquid-guiding pipe 31 and the reflux pipe 40 constitute the first circulation pipe 23.

[0112] As Figure 2 shown, the sulfuric acid replenishing unit 25 is a unit for supplying new sulfuric acid (sulfuric acid not yet used for the treatment of the substrate W) to the first circulation tank 22. The sulfuric acid replenishing unit 25 includes a sulfuric acid replenishing pipe 44 for replenishing sulfuric acid to the first circulation tank 22, and a sulfuric acid replenishing valve 45 for opening and closing the sulfuric acid replenishing pipe 44. The replenished sulfuric acid is unused sulfuric acid (e.g., concentrated sulfuric acid), and its sulfuric acid concentration is higher than the sulfuric acid concentration in the sulfuric acid-containing liquid in the first circulation tank 22. The replenished sulfuric acid is at room temperature (about 23°C to about 25°C).

[0113] During the operation of the substrate processing apparatus 1 (including the period when the processing of the substrate W is stopped), the second liquid supply device 32 and the first circulation heater 24 are always driven. Therefore, by closing the on-off valve 38 and opening the reflux valve 41, the sulfuric acid-containing liquid drawn from the first circulation tank 22 flows along the first liquid guide pipe 31 to the branch position 42, and returns from the branch position 42 to the first circulation tank 22 through the reflux pipe 40. That is, during the period when the sulfuric acid-containing liquid is not supplied to the second liquid storage unit 12, the sulfuric acid-containing liquid circulates along the first circulation tank 22 and the first circulation pipe 23. Then, when it is time to supply the sulfuric acid-containing liquid to the second liquid storage unit 12, by opening the on-off valve 38 and closing the reflux valve 41, the sulfuric acid-containing liquid drawn from the first circulation tank 22 is supplied to the second liquid storage unit through the first liquid guide pipe 31.

[0114] As Figure 2 shown, the first circulation heater 24 is interposed on the upstream side of the second liquid supply device 32 in the middle part of the first liquid guide pipe 31. The first circulation heater 24 heats the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 (second heating step). The heating temperature of the first circulation heater 24 is set to a specified first temperature (second heating temperature, for example, about 120 °C to about 130 °C). By circulating the sulfuric acid-containing liquid along the first circulation tank 22 and the first circulation pipe 23, the sulfuric acid-containing liquid is adjusted to the first temperature. During the period when the sulfuric acid-containing liquid is not supplied to the second liquid storage unit 12, by previously circulating the sulfuric acid-containing liquid, the sulfuric acid-containing liquid adjusted to the first temperature can be previously stored in the first circulation tank 22. In addition, after the on-off valve 38 can be opened, the sulfuric acid-containing liquid adjusted to the first temperature can be supplied to the second liquid storage unit 12.

[0115] As Figure 2 shown, the first liquid storage unit 11 further includes a drain tank 50. A drain pipe 46 extending toward the drain tank 50 is connected to the first circulation tank 22. A drain valve 47 for opening and closing the drain pipe 46 is interposed in the middle part of the drain pipe 46. When the sulfuric acid-containing liquid stored in the first circulation tank 22 is not further used for the processing of the substrate W, the drain valve 47 is opened, and the sulfuric acid-containing liquid stored in the first circulation tank 22 is discharged from the first circulation tank 22 and guided to the drain tank 50, and stored in the drain tank 50.

[0116] As Figure 2As shown, the discharge pipe 48 extends from the liquid discharge tank 50, and the downstream end of the discharge pipe 48 is connected to a cooling unit (not shown). A third liquid feeding device 49 such as a pump is installed in the discharge pipe 48. When the third liquid feeding device 49 is driven, the sulfuric acid-containing liquid stored in the liquid discharge tank 50 is drawn into the discharge pipe 48 and supplied to the cooling unit. Then, the sulfuric acid-containing liquid cooled by the cooling unit is guided to a waste liquid device (not shown) provided outside the machine, where it is processed.

[0117] The first liquid storage section 11 has been described above. In the first liquid storage section 11, the SPM recovered from the processing unit 6 is stored as a sulfuric acid-containing liquid in the first circulation tank 22. The sulfuric acid-containing liquid stored in the first circulation tank 22 circulates along the first circulation pipe 23. In addition, sulfuric acid from the sulfuric acid supply unit 25 is replenished into the first circulation tank 22. Since the sulfuric acid supply unit 25 is provided, the first liquid storage section 11 can be understood as a liquid storage section for adjusting the sulfuric acid concentration.

[0118] Figure 4 is a view obtained by observing the second sulfuric acid-containing liquid supply device 10 and the device main body 2 shown respectively Figure 1 from a horizontal direction.

[0119] The second liquid storage section 12 included in the second sulfuric acid-containing liquid supply device 10 includes a second circulation tank (second tank) 51, a second circulation heater (first heater) 52, a second circulation pipe 53, and a heater (third heater) 54.

[0120] The downstream end of the first liquid guiding pipe 31 is connected to the second circulation tank 51. The sulfuric acid-containing liquid whose temperature is adjusted to the first temperature (for example, about 120°C to about 130°C) in the first liquid storage section 11 is guided to the second circulation tank 51. Moreover, the guided sulfuric acid-containing liquid is stored in the second circulation tank 51 (second storage step).

[0121] In the second circulation tank 51, liquid level gauges 65 each having a sensor section are installed at a plurality of positions with different heights, and the liquid level height of the sulfuric acid-containing liquid stored in the second circulation tank 51 is detected by these liquid level gauges 65.

[0122] A common pipe 51A is connected to the second circulation tank 51. A second circulation heater 52 is installed in the middle of the common pipe 51A.

[0123] Three sulfuric acid-containing liquid flow pipes 51B are connected to the second circulation tank 51 and the common pipe 51A. Specifically, the upstream ends of the three sulfuric acid-containing liquid flow pipes 51B for supplying sulfuric acid-containing liquid to the corresponding towers are connected to the downstream end of the common pipe 51A. The downstream ends of the three sulfuric acid-containing liquid flow pipes 51B are connected to the second circulation tank 51. The second circulation pipe 53 is constituted by the common pipe 51A and the sulfuric acid-containing liquid flow pipes 51B. A fourth liquid feeding device 56 such as a pump for sucking the sulfuric acid-containing liquid in the common pipe 51A is interposed in the middle of the sulfuric acid-containing liquid flow pipe 51B. The sulfuric acid-containing liquid sucked into the second circulation pipe 53 by the fourth liquid feeding device 56 flows from the upstream end to the downstream end along the sulfuric acid-containing liquid flow pipe 51B and returns to the second circulation tank 51. Thus, the sulfuric acid-containing liquid circulates along the second circulation tank 51 and the second circulation pipe 53 (the common pipe 51A and the sulfuric acid-containing liquid flow pipes 51B).

[0124] In Figure 4 it, only one tower is illustrated in detail, and for the other two towers, only "other towers" is recorded, and the detailed description is omitted.

[0125] The second circulation heater 52 heats the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation pipe 53 (the common pipe 51A and the sulfuric acid-containing liquid flow pipes 51B) (the first heating step). The heating temperature of the second circulation heater 52 is set to a specified second temperature (> the first temperature, the first heating temperature, for example, about 160 °C). By circulating the sulfuric acid-containing liquid along the second circulation tank 51 and the second circulation pipe 53 (the common pipe 51A and the sulfuric acid-containing liquid flow pipes 51B), the sulfuric acid-containing liquid is adjusted from the so far first temperature to the second temperature.

[0126] The second liquid storage part 12 includes sulfuric acid-containing liquid supply pipes 57 having the same number as the number of treatment units 6 included in the tower. The sulfuric acid-containing liquid supply pipes 57 branch from the second circulation pipe 53 and are used to supply sulfuric acid-containing liquid to a plurality of (three) treatment units 6 included in the corresponding tower.

[0127] A heater (third heater) 54 is interposed in the middle of each sulfuric acid-containing liquid supply pipe 57. In addition, in the middle of each sulfuric acid-containing liquid supply pipe 57, on the downstream side of the heater 54, a flowmeter 58, a sulfuric acid-containing liquid flow rate adjustment valve (mixing ratio change unit) 59 and a sulfuric acid-containing liquid valve 60 are interposed in sequence from the heater 54 side.

[0128] The flowmeter 58 is a flowmeter for detecting the flow rate of the sulfuric acid-containing liquid flowing in each sulfuric acid-containing liquid supply pipe 57.

[0129] The sulfuric acid-containing liquid flow rate adjustment valve 59 is a valve that adjusts the opening degree of the sulfuric acid-containing liquid supply pipe 57 to adjust the flow rate of the sulfuric acid-containing liquid supplied to the SPM nozzle 13. The sulfuric acid-containing liquid flow rate adjustment valve 59 may also be configured to include a valve body with a valve seat provided inside, a valve body that opens and closes the valve seat, and an actuator that moves the valve body between an open position and a closed position.

[0130] The sulfuric acid-containing liquid valve 60 is a valve that controls the supply and stop of the sulfuric acid-containing liquid to the SPM nozzle 13.

[0131] In the sulfuric acid-containing liquid supply pipe 57, a reflux pipe 61 is branched and connected between the sulfuric acid-containing liquid valve 60 and the sulfuric acid-containing liquid flow rate adjustment valve 59. The downstream end of the reflux pipe 61 is connected to the sulfuric acid-containing liquid flow-through pipe 51B. The pressure loss of the upstream side portion of the branch position 63 in the sulfuric acid-containing liquid supply pipe 57 is greater than the pressure loss in the reflux pipe 61.

[0132] When supplying the sulfuric acid-containing liquid to the SPM nozzle 13, the control device 4 opens the sulfuric acid-containing liquid valve 60. As a result, the pressure loss in the reflux pipe 61 is greater than the pressure loss of the downstream side portion of the branch position 63 in the sulfuric acid-containing liquid supply pipe 57. Therefore, the sulfuric acid-containing liquid in the upstream side portion of the branch position 63 in the sulfuric acid-containing liquid supply pipe 57 is supplied to the downstream side portion of the branch position 63 in the sulfuric acid-containing liquid supply pipe 57, and is supplied to the SPM nozzle 13 from the downstream side portion.

[0133] When stopping the supply of the sulfuric acid-containing liquid to the SPM nozzle 13, the control device 4 closes the sulfuric acid-containing liquid valve 60. As a result, the pressure loss in the reflux pipe 61 is less than the pressure loss of the downstream side portion of the branch position 63 in the sulfuric acid-containing liquid supply pipe 57. Therefore, the sulfuric acid-containing liquid that has reached the branch position 63 does not flow back along the upstream side portion of the branch position 63 in the sulfuric acid-containing liquid supply pipe 57, but is guided to the reflux pipe 61. The sulfuric acid-containing liquid guided to the reflux pipe 61 returns to the sulfuric acid-containing liquid flow-through pipe 51B, and circulates again along the second circulation tank 51 and the second circulation pipe 53 (the common pipe 51A and the sulfuric acid-containing liquid flow-through pipe 51B).

[0134] The heater 54 heats the sulfuric acid-containing liquid flowing along the sulfuric acid-containing liquid supply pipe 57. The heating temperature of the heater 54 is set to a specified third temperature (> second temperature, for example, about 165 °C). As the sulfuric acid-containing liquid flows along the sulfuric acid-containing liquid supply pipe 57, the sulfuric acid-containing liquid whose temperature has been adjusted to the second temperature so far is heated from the second temperature so far to the third temperature.

[0135] During the operation of the substrate processing apparatus 1 (including the period when the processing of the substrate W is stopped), the fourth liquid supply device 56 and the second circulation heater 52 are always driven. Therefore, during the operation of the substrate processing apparatus 1, the sulfuric acid-containing liquid adjusted to the second temperature circulates along the second circulation tank 51 and the second circulation pipe 53 (the common pipe 51A and the sulfuric acid-containing liquid circulation pipe 51B).

[0136] In a state where the sulfuric acid-containing liquid valve 60 is closed, the sulfuric acid-containing liquid flowing through the second circulation pipe 53 flows from the second circulation pipe 53 to the sulfuric acid-containing liquid supply pipe 57, flows through the branch position 63 to the reflux pipe 61, and returns to the sulfuric acid-containing liquid circulation pipe 51B. Thereby, it circulates along the second circulation tank 51 and the second circulation pipe 53.

[0137] On the other hand, in a state where the sulfuric acid-containing liquid valve 60 is open, the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid circulation pipe 51B flows from the second circulation pipe 53 to the sulfuric acid-containing liquid supply pipe 57 and is supplied to the SPM nozzle 13. That is, the sulfuric acid-containing liquid adjusted to the third temperature is supplied to the SPM nozzle 13.

[0138] By referring to the output of the liquid volume gauge 65, the liquid volume of the sulfuric acid-containing liquid accumulated in the second circulation tank 51 is always monitored by the control device 4. Moreover, when the liquid volume of the sulfuric acid-containing liquid accumulated in the second circulation tank 51 is less than the lower limit liquid volume, the on-off valve 38 is opened, and the sulfuric acid-containing liquid is supplied from the first liquid storage unit 11 through the first liquid guide pipe 31.

[0139] In one of the three sulfuric acid-containing liquid circulation pipes 51B, a sulfuric acid concentration meter 64 is installed on the downstream side of the fourth liquid supply device 56. The sulfuric acid concentration meter 64 measures the sulfuric acid concentration of the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid circulation pipe 51B (that is, the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation pipe 53). It is considered that the sulfuric acid concentrations of the sulfuric acid-containing liquids flowing through the three second circulation pipes 53 are the same. Therefore, the sulfuric acid concentration meter 64 only needs to be installed in one of the three second circulation pipes 53.

[0140] By referring to the output of the sulfuric acid concentration meter 64, that is, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating in the second circulation tank 51 and the second circulation pipe 53 (the sulfuric acid concentration of the sulfuric acid-containing liquid accumulated in the second circulation tank 51) is always monitored by the control device 4. Moreover, when the sulfuric acid concentration of the sulfuric acid-containing liquid circulating in the second circulation tank 51 and the second circulation pipe 53 is lower than the lower limit concentration, the sulfuric acid supply valve 45 that opens and closes the sulfuric acid supply pipe 44 is opened, and sulfuric acid is supplied to the first circulation tank 22 (sulfuric acid supply step). As a result, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating in the first circulation tank 22 and the first circulation pipe 23 becomes higher. Subsequently, after a short period, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating in the second circulation tank 51 and the second circulation pipe 53 becomes higher.

[0141] The above describes the second liquid storage unit 12. In the second liquid storage unit 12, the sulfuric acid-containing liquid transported from the first liquid storage unit 11 is stored in the second circulation tank 51. The sulfuric acid-containing liquid stored in the second circulation tank 51 is heated. As a result, the temperature of the sulfuric acid-containing liquid in the second liquid storage unit 12 can be raised to a temperature suitable for processing. Therefore, the second liquid storage unit 12 can be understood as a liquid storage unit for adjusting the temperature of the sulfuric acid-containing liquid.

[0142] Figure 5 It is a schematic cross-sectional view for explaining a configuration example of the processing unit 6.

[0143] The processing unit 6 includes: a box-shaped chamber 107 having an internal space; a rotary chuck (substrate holding unit) 108 that holds one substrate W in a horizontal posture in the chamber 107 and rotates the substrate W around a vertical rotation axis A1 passing through the center of the substrate W; an SPM nozzle 13; a rinse liquid supply unit 110 for supplying a rinse liquid to the upper surface of the substrate W held by the rotary chuck 108; and a cylindrical processing susceptor 111 that surrounds the rotary chuck 108.

[0144] The chamber 107 includes: a box-shaped partition wall 112; an FFU (Fan Filter Unit) 114 as a ventilation unit that transports clean air from the upper part of the partition wall 112 into the partition wall 112 (equivalent to the inside of the chamber 107); and an exhaust device (not shown) that discharges the gas in the chamber 107 from the lower part of the partition wall 112. The FFU 114 is disposed above the partition wall 112 and is mounted on the top plate of the partition wall 112. The FFU 114 transports clean air from the top plate of the partition wall 112 into the chamber 107. The exhaust device (not shown) is connected to the bottom of the processing susceptor 111 via an exhaust pipe 113 connected to the processing susceptor 111, and sucks the gas in the processing susceptor 111 from the bottom of the processing susceptor 111. A downflow (descending flow) is formed in the chamber 107 by the FFU 114 and the exhaust device (not shown).

[0145] As the rotary chuck 108, a clamping chuck that clamps the substrate W in the horizontal direction and holds the substrate W horizontally is adopted. Specifically, the rotary chuck 108 includes: a rotary motor (rotary unit) M; a rotary shaft 115 integrated with the drive shaft of the rotary motor M; and a disk-shaped rotary base 116 mounted substantially horizontally on the upper end of the rotary shaft 115.

[0146] The rotary base 116 includes a horizontal circular upper surface 116a having an outer diameter larger than the outer diameter of the substrate W. A plurality (three or more, for example, six) of clamping members 117 are arranged at the peripheral portion of the upper surface 116a. The plurality of clamping members 117 are arranged at appropriate intervals on the circumferential periphery of the upper surface of the rotary base 116 on a circumference corresponding to the outer peripheral shape of the substrate W.

[0147] The SPM nozzle 13 is, for example, a linear nozzle that ejects SPM in a continuous flow state. The SPM nozzle 13 is mounted at the front end of the nozzle arm 119. The SPM nozzle 13 is mounted on the nozzle arm 119 in a vertical posture, for example, in a direction perpendicular to the upper surface of the substrate W to eject the processing liquid (SPM). The nozzle arm 119 extends in the horizontal direction. In addition, a nozzle moving unit 120 that moves the SPM nozzle 13 by moving the nozzle arm 119 is coupled to the nozzle arm 119. The nozzle moving unit 120 is configured to include an electric motor.

[0148] The nozzle moving unit 120 horizontally moves the SPM nozzle 13 by swinging the nozzle arm 119 around a vertical swing axis set around the processing cup 111. The nozzle moving unit 120 horizontally moves the SPM nozzle 13 between a processing position where the SPM ejected from the SPM nozzle 13 lands on the upper surface of the substrate W and a retracted position where the SPM nozzle 13 is located around the rotary chuck 108 in a plan view. In the present embodiment, the processing position is, for example, a central position where the SPM ejected from the SPM nozzle 13 lands on the central portion of the upper surface of the substrate W.

[0149] The processing liquid supply device includes a hydrogen peroxide water supply unit 122 that supplies hydrogen peroxide water (H2O2) to the SPM nozzle 13. The hydrogen peroxide water supply unit 122 includes: a hydrogen peroxide water pipe 135 connected to the SPM nozzle 13; a hydrogen peroxide water valve 136 for opening and closing the hydrogen peroxide water pipe 135; and a hydrogen peroxide water flow rate adjustment valve (mixing ratio change unit) 137 that adjusts the opening degree of the hydrogen peroxide water valve 136 to adjust the flow rate of the hydrogen peroxide water flowing through the hydrogen peroxide water valve 136. The hydrogen peroxide water flow rate adjustment valve 137 may also be configured to include a valve body with a valve seat provided inside, a valve body for opening and closing the valve seat, and an actuator for moving the valve body between an open position and a closed position. Hydrogen peroxide water at about room temperature (20 - 40°C) with unadjusted temperature is supplied from a hydrogen peroxide water supply source (not shown) to the hydrogen peroxide water pipe 135.

[0150] When the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide water valve 136 are opened, the high-temperature (165°C) sulfuric acid-containing liquid from the sulfuric acid-containing liquid supply pipe 57 and the hydrogen peroxide water from the hydrogen peroxide water pipe 135 are supplied into the housing (not shown) of the SPM nozzle 13 and are sufficiently mixed (stirred) inside the housing. Through this mixing, the sulfuric acid-containing liquid and the hydrogen peroxide water are evenly mixed together, and a mixed liquid (SPM) of sulfuric acid and hydrogen peroxide water is generated by the reaction between the sulfuric acid contained in the sulfuric acid-containing liquid and the hydrogen peroxide water. The SPM contains peroxomonosulfuric acid (H2SO5) with strong oxidizing power and is heated to a temperature higher than the temperatures of the sulfuric acid-containing liquid (e.g., about 165°C) and the hydrogen peroxide water before mixing (e.g., about 190°C - about 220°C). The generated high-temperature SPM is ejected from the ejection port that opens at the front end (e.g., the lower end) of the housing of the SPM nozzle 13.

[0151] The flow rate of the sulfuric acid-containing liquid supplied to the SPM nozzle 13 is changed by the sulfuric acid-containing liquid flow rate adjustment valve 59. The flow rate of the hydrogen peroxide water supplied to the SPM nozzle 13 is changed by the hydrogen peroxide water flow rate adjustment valve 137. Therefore, the mixing ratio of the sulfuric acid-containing liquid and the hydrogen peroxide water is changed by the sulfuric acid-containing liquid flow rate adjustment valve 59 and the hydrogen peroxide water flow rate adjustment valve 137. The mixing ratio of the sulfuric acid-containing liquid and the hydrogen peroxide water (the flow rate ratio of the sulfuric acid-containing liquid and the hydrogen peroxide water) is adjusted, for example, within the range of 30:1 (sulfuric acid-containing liquid:hydrogen peroxide water) - 2:1 (sulfuric acid-containing liquid:hydrogen peroxide water).

[0152] The rinse liquid supply unit 110 includes a rinse liquid nozzle 147 that ejects rinse liquid toward the upper surface of the substrate W. The rinse liquid nozzle 147 is, for example, a linear nozzle that ejects liquid in a continuous flow state. The rinse liquid nozzle 147 is a fixed nozzle fixed to the partition wall 112 between the chambers 107. The ejection port of the rinse liquid nozzle 147 faces the central portion of the upper surface of the substrate W. The rinse liquid nozzle 147 may also be a scanning nozzle that can move within the chamber 107. That is, the rinse liquid supply unit 110 may also include a nozzle moving unit that moves the rinse liquid nozzle 147 to move the landing position of the rinse liquid on the upper surface of the substrate W within the upper surface of the substrate W.

[0153] The rinse liquid nozzle 147 is connected to a rinse liquid pipe 148 that guides the rinse liquid from the rinse liquid supply source. In the middle of the rinse liquid pipe 148, a rinse liquid valve 149 for switching the supply / supply stop of the rinse liquid from the rinse liquid nozzle 147 is interposed. When the rinse liquid valve 149 is opened, the rinse liquid is supplied from the rinse liquid pipe 148 to the rinse liquid nozzle 147 and ejected from the ejection port provided at the lower end of the rinse liquid nozzle 147.

[0154] When the rinse liquid valve 149 is closed, the supply of the rinse liquid from the rinse liquid pipe 148 to the rinse liquid nozzle 147 is stopped. The rinse liquid is, for example, deionized water (DIW (Deionized Water)), but is not limited to DIW, and may be any one of carbonated water, electrolyzed ion water, hydrogen water, ozone water, ammonia water, and hydrochloric acid water with a dilution concentration (for example, about 10 ppm to 100 ppm). The rinse liquid can be at room temperature (20 to 40 °C) or can be heated before being supplied to the substrate W.

[0155] The processing susceptor 111 is disposed outside the substrate W held by the rotary chuck 108 (in the direction away from the rotation axis A1). The processing susceptor 111 surrounds the side of the rotary base 116. When the processing liquid is supplied to the substrate W while the substrate W is rotating on the rotary chuck 108, the processing liquid supplied to the substrate W is thrown off to the periphery of the substrate W. When the processing liquid is supplied to the substrate W, the upper end portion 111a of the upwardly open processing susceptor 111 is disposed above the rotary base 116. Therefore, the processing liquid such as the chemical solution or water discharged to the periphery of the substrate W is received by the processing susceptor 111. Moreover, the processing liquid received by the processing susceptor 111 is transported to the recovery tank 21 of the first liquid storage unit 11 or transported to a waste liquid device (not shown) via a cooling unit (not shown).

[0156] The processing cup 111 includes: a plurality of cylindrical shields (the first shield 143, the second shield 144, and the third shield 145) for receiving the processing liquid (chemical liquid or rinse liquid) scattered around the substrate W; a plurality of annular cups (the first cup 141 and the second cup 142) for receiving the processing liquid guided by the plurality of shields; and a cylindrical member 140 surrounding the plurality of shields and the plurality of cups.

[0157] The processing cup 111 further includes a shield lifting unit 146 for independently lifting and lowering each shield (the first shield 143, the second shield 144, and the third shield 145). The shield lifting unit 146 includes, for example, an electric motor that generates power, and a ball screw mechanism that transmits the power of the electric motor to any one of the shields. If the shield lifting unit 146 lifts or lowers at least one of the three shields, the state of the processing cup 111 is switched.

[0158] As described below, the state of the processing cup 111 can be switched to a retracted state where the upper ends of all the shields are disposed below the substrate W ( Figure 5 the state shown), a first facing state where the first shield 143 faces the peripheral end face of the substrate W, a second facing state where the second shield 144 faces the peripheral end face of the substrate W, or a third facing state where the third shield 145 faces the peripheral end face of the substrate W.

[0159] The first cup 141 surrounds the rotary chuck 108 inside the cylindrical member 140. The first cup 141 defines a ring-shaped first groove 150 into which the processing liquid for processing the substrate W flows. A drain port 151 is opened at the lowest part of the bottom of the first groove 150, and a first drain pipe 152 is connected to the drain port 151. The processing liquid introduced into the first drain pipe 152 is transported to the drain device and processed in the device.

[0160] The second cup 142 surrounds the first cup 141 inside the cylindrical member 140. The second cup 142 defines a ring-shaped second groove 153 into which the processing liquid for processing the substrate W flows. A drain / recovery port 154 is opened at the lowest part of the bottom of the second groove 153, and a common pipe 155 is connected to the drain / recovery port 154. A recovery pipe 156 and a second drain pipe 157 branch from the common pipe 155. The upstream end of the recovery pipe 156 is connected to the common pipe 155, and the downstream end of the recovery pipe 156 is connected to the recovery tank 21 of the first liquid storage unit 11.

[0161] A recovery valve 158 is installed in the recovery pipe 156, and a drain valve 159 is installed in the second drain pipe 157. When the drain valve 159 is closed and the recovery valve 158 is opened, the liquid flowing in the common pipe 155 is guided to the recovery pipe 156. In addition, when the drain valve 159 is opened and the recovery valve 158 is closed, the liquid flowing in the common pipe 155 is guided to the second drain pipe 157. The recovery valve 158 and the drain valve 159 are included in a recovery / drain switching unit that switches the pipe for the liquid discharged from the substrate W to flow into between the recovery pipe 156 and the second drain pipe 157.

[0162] The innermost first shield 143 surrounds the rotating chuck 108 inside the cylindrical member 140. The first shield 143 includes: a cylindrical lower end portion 163 that surrounds the periphery of the rotating chuck 108; a cylindrical portion 164 that extends outward (in a direction away from the rotation axis A1 of the substrate W) from the upper end of the lower end portion 163; a cylindrical middle portion 165 that extends vertically upward from the upper end of the cylindrical portion 164; and an annular upper end portion 166 that extends obliquely upward from the upper end of the middle portion 165 toward the inside (in a direction approaching the rotation axis A1 of the substrate W).

[0163] The lower end portion 163 of the first shield 143 is located on the first groove 150 of the first cup 141. The inner peripheral end of the upper end portion 166 of the first shield 143 is circular in plan view and has a diameter larger than that of the substrate W held by the rotating chuck 108. As Figure 5 shown, the cross-sectional shape of the upper end portion 166 of the first shield 143 is linear. The cross-sectional shape of the upper end portion 166 may also be a shape other than linear, such as an arc.

[0164] The second shield 144, which is the second from the inside, surrounds the first shield 143 inside the cylindrical member 140. The second shield 144 has a cylindrical portion 167 that surrounds the first shield 143 and an annular upper end portion 168 that extends obliquely upward from the upper end of the cylindrical portion 167 toward the center side (in a direction approaching the rotation axis A1 of the substrate W). The cylindrical portion 167 of the second shield 144 is located on the second groove 153 of the second cup 142.

[0165] The inner peripheral end of the upper end portion 168 of the second shield 144 is circular in plan view and has a diameter larger than that of the substrate W held by the rotating chuck 108. The cross-sectional shape of the upper end portion 168 of the second shield 144 is linear. The cross-sectional shape of the upper end portion 168 may also be a shape other than linear, such as an arc. The upper end portion 168 of the second shield 144 overlaps the upper end portion 166 of the first shield 143 in the vertical direction. The upper end portion 168 of the second shield 144 is formed so as to approach the upper end portion 166 of the first shield 143 while maintaining a slight gap in the state where the first shield 143 and the second shield 144 are closest to each other.

[0166] The third shield 145, which is the third one from the inside, surrounds the second shield 144 inside the cylindrical member 140. The third shield 145 has a cylindrical portion 170 surrounding the second shield 144 and an annular upper end portion 171 extending obliquely upward from the upper end of the cylindrical portion 170 toward the center side (the direction approaching the rotation axis A1 of the substrate W). The inner peripheral end of the upper end portion 171 is circular in a plan view and has a diameter larger than that of the substrate W held by the rotary chuck 108. The cross-sectional shape of the upper end portion 171 is linear. The cross-sectional shape of the upper end portion 171 may also be a shape other than linear, such as an arc.

[0167] The first groove 150 of the first susceptor 141, the inner wall 143a of the first shield 143, and the outer periphery of the housing of the rotary chuck 108 define a first flow space (in other words, a drainage space) SP1 for guiding the liquid medicine for processing the substrate W. The second groove 153 of the second susceptor 142, the outer wall 143b of the first shield 143, and the inner wall 144a of the second shield 144 define a second flow space (in other words, a recovery space) SP2 for guiding the liquid medicine for processing the substrate W. The first flow space SP1 and the second flow space SP2 are separated from each other by the first shield 143.

[0168] The shield lifting unit 146 raises and lowers each shield (the first shield 143, the second shield 144, and the third shield 145) between an upper position where the upper end portion of the shield is above the substrate W and a lower position where the upper end portion of the shield is below the substrate W. The shield lifting unit 146 can hold each shield at any position between the upper position and the lower position. The supply of the processing liquid to the substrate W is performed in a state where any one of the shields faces the peripheral end surface of the substrate W.

[0169] In the first facing state of the processing susceptor 111 where the innermost first shield 143 faces the peripheral end surface of the substrate W, all of the first shield 143, the second shield 144, and the third shield 145 are arranged at the upper position (processing height position). In the second facing state of the processing susceptor 111 where the second shield 144, which is the second one from the inside, faces the peripheral end surface of the substrate W, the second and third shields 144 and 145 are arranged at the upper position, and the first shield 143 is arranged at the lower position. In the third facing state of the processing susceptor 111 where the outermost third shield 145 faces the peripheral end surface of the substrate W, the third shield 145 is arranged at the upper position, and the first shield 143 and the second shield 144 are arranged at the lower position. In the retracted state where all the shields are retracted from the peripheral end surface of the substrate W (refer to Figure 5 ), all of the first shield 143, the second shield 144, and the third shield 145 are arranged at the lower position.

[0170] As described below, when the processing susceptor 111 is switched from the first facing state to the second facing state, the first shield 143 is disposed at a cleaning height position between the upper position and the lower position in a state where the second shield 144 and the third shield 145 are disposed at the upper position. This state is a transition state in which the processing susceptor 111 is switched from the first facing state to the second facing state. The processing susceptor 111 is switched to any one of a plurality of states including the first to third facing states, the retracted state, and the transition state. The transition state is a state in which the first shield 143 faces the peripheral end face of the substrate W.

[0171] Figure 6 It is a block diagram for explaining the electrical configuration of the substrate processing apparatus 1.

[0172] The control device 4 is, for example, a computer. The control device 4 includes an arithmetic unit such as a CPU (Central Processing Unit), a fixed memory device, a storage unit such as a hard disk drive, and an input / output unit for inputting and outputting information. The storage unit includes a computer-readable recording medium on which a computer program executed by the arithmetic unit is recorded. In the recording medium, a group of steps is incorporated so that the control device 4 executes the following resist removal process.

[0173] The control device 4 controls the operations of the rotation motor M, the nozzle moving unit 120, the shield lifting unit 146, the first liquid supply device 29, the second liquid supply device 32, the third liquid supply device 49, the fourth liquid supply device 56, the first circulation heater 24, the second circulation heater 52, the heater 54, etc. according to a pre-specified program. In addition, the control device 4 controls the opening and closing operations of the on-off valve 38, the reflux valve 41, the sulfuric acid supply valve 45, the drain valve 47, the sulfuric acid-containing liquid valve 60, the hydrogen peroxide water valve 136, the rinse liquid valve 149, the recovery valve 158, the drain valve 159, etc. according to a pre-specified program. In addition, the control device 4 adjusts the opening degrees of the sulfuric acid-containing liquid flow rate adjustment valve 59 and the hydrogen peroxide water flow rate adjustment valve 137 according to a pre-specified program. The measured values of the sulfuric acid concentration meter 64 and the liquid volume meter 65 are respectively input to the control device 4.

[0174] Figure 7 It is a flowchart for explaining an example of the processing of the substrate W by the substrate processing apparatus 1.

[0175] Hereinafter, with reference to Figures 1 to 7 , an example of the processing of the substrate W will be described. An example of the processing of the substrate W is a resist removal process for removing a resist from the upper surface (main surface) of the substrate W. The resist is, for example, a photoresist formed of a carbon-containing compound.

[0176] When the substrate W is processed by the substrate processing apparatus 1, the control device 4 causes the substrate transfer robot (the first substrate transfer robot CR1, the second substrate transfer robot CR2 (refer to Figure 1 )) of the substrate W, with at least a part of the front surface (device formation surface) of the substrate W covered with resist, to enter the interior of the chamber 107 in a state where all the nozzles are retracted from above the rotary chuck 108 and all the shields 143 to 145 are in the lower position. Thus, the substrate W is transferred to the rotary chuck 108 with its front surface facing upward and held by the rotary chuck 108.

[0177] After the substrate W is held by the rotary chuck 108, the control device 4 causes the rotary motor M to start rotating. Thus, the substrate W starts to rotate ( Figure 7 S2). The rotational speed of the substrate W rises to a predetermined liquid processing speed (within the range of 300 to 1500 rpm, for example, 500 rpm) and is maintained at this liquid processing speed. Then, when the rotational speed of the substrate W reaches the liquid processing speed, the control device 4 executes the SPM step S3.

[0178] Specifically, the control device 4 controls the nozzle moving unit 120 to move the SPM nozzle 13 from the retracted position to the processing position. In addition, the control device 4 simultaneously opens the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide water valve 136. Thus, the sulfuric acid-containing liquid is supplied to the SPM nozzle 13 through the sulfuric acid-containing liquid supply pipe 57, and the hydrogen peroxide water is supplied to the SPM nozzle 13 through the hydrogen peroxide water pipe 135. Inside the SPM nozzle 13, the sulfuric acid-containing liquid and the hydrogen peroxide water are mixed to generate high-temperature (for example, 190 to 220 °C) SPM. This SPM is ejected from the ejection port of the SPM nozzle 13 and lands on the central portion of the upper surface of the substrate W.

[0179] After the SPM ejected from the SPM nozzle 13 lands on the upper surface of the substrate W, it flows outward along the upper surface of the substrate W by centrifugal force. Therefore, the SPM is supplied to the entire area of the upper surface of the substrate W, and a liquid film of SPM covering the entire area of the upper surface of the substrate W is formed on the substrate W. Thus, a chemical reaction occurs between the resist and the SPM, and the resist on the substrate W is removed from the substrate W by the SPM. The SPM that has moved to the peripheral portion of the substrate W scatters from the peripheral portion of the substrate W toward the side of the substrate W.

[0180] In addition, in the SPM step S3, the control device 4 can also control the nozzle moving unit 120 to move the SPM nozzle 13 between a peripheral position facing the peripheral portion of the upper surface of the substrate W and a central position facing the central portion of the upper surface of the substrate W. In this case, the liquid application position of the SPM on the upper surface of the substrate W passes through the entire area of the upper surface of the substrate W. Therefore, the entire area of the upper surface of the substrate W is scanned by the liquid application position of the SPM. Thereby, the entire area of the upper surface of the substrate W can be uniformly processed.

[0181] When a predetermined period has elapsed since the start of spraying the SPM, the control device 4 closes the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide water valve 136 to stop spraying the SPM from the SPM nozzle 13. Thereby, the SPM step S3 ends. Then, the control device 4 controls the nozzle moving unit 120 (refer to Figure 6 ) to return the SPM nozzle 13 to the retracted position.

[0182] Next, a rinsing step of supplying a rinsing liquid to the substrate W ( Figure 7 S4) is performed. Specifically, the control device 4 opens the rinsing liquid valve 149 to cause the rinsing liquid nozzle 147 to spray the rinsing liquid toward the central portion of the upper surface of the substrate W. The rinsing liquid sprayed from the rinsing liquid nozzle 147 lands on the central portion of the upper surface of the substrate W covered with the SPM. The rinsing liquid landing on the central portion of the upper surface of the substrate W receives the centrifugal force generated by the rotation of the substrate W and flows toward the peripheral portion of the substrate W on the upper surface of the substrate W. Thereby, the SPM on the substrate W is washed away outward by the rinsing liquid and discharged to the periphery of the substrate W. As a result, the SPM and the resist (resist residue) are rinsed from the entire area of the upper surface of the substrate W. When a predetermined period has elapsed since the start of the rinsing step S4, the control device 4 closes the rinsing liquid valve 149 to stop the rinsing liquid nozzle 147 from spraying the rinsing liquid.

[0183] Next, a drying step of drying the substrate W ( Figure 7 S5) is performed. Specifically, the control device 4 controls the rotation motor M to accelerate the substrate W to a drying rotation speed (for example, several thousand rpm) that is higher than the rotation speed until the SPM step S3 and the rinsing step S4, and rotates the substrate W at the drying rotation speed. Thereby, a large centrifugal force is applied to the liquid on the substrate W, and the liquid attached to the substrate W is thrown to the periphery of the substrate W. In this way, the liquid is removed from the substrate W, and the substrate W is dried. Then, when a specified time has elapsed after the high-speed rotation of the substrate W starts, the control device 4 stops the rotation motor M to stop the rotation of the substrate W based on the rotary chuck 108 ( Figure 7 S6).

[0184] Next, the substrate W is carried out of the chamber 107 ( Figure 7of S7). Specifically, in a state where all the shields 143 to 145 are in the lower position, the control device 4 causes the hand of the substrate transfer robot (the first substrate transfer robot CR1, the second substrate transfer robot CR2 (refer to Figure 1 )) to enter the interior of the chamber 107. Then, the control device 4 causes the substrate W on the rotary chuck 108 to be held by the hand of the substrate transfer robot. Then, the control device 4 causes the hand of the substrate transfer robot to retract from the interior of the chamber 107. Thereby, the substrate W after removing the resist from the front surface (device formation surface) is carried out of the chamber 107.

[0185] Next, the transition of the mixing ratio of the sulfuric acid-containing liquid and the hydrogen peroxide water and the operations of the first shield 143 and the second shield 144 in the SPM step ( Figure 7 of S3) will be described.

[0186] Figure 8 is a timing chart showing the transition of the mixing ratio of the sulfuric acid-containing liquid and the hydrogen peroxide water and the operations of the first shield 143 and the second shield 144 in the SPM step ( Figure 7 of S3). In Figure 8 , the recovered ON (operation) indicates that the SPM discharged from the substrate W flows into the recovery pipe 156 via the second shield 144, and the recovered OFF (abort) indicates that the inflow of the SPM into the recovery pipe 156 stops. In Figure 8 , the drainage operation indicates that the SPM discharged from the substrate W flows into the first drainage pipe 152 via the first shield 143, and the drainage abort indicates that the inflow of the SPM into the first drainage pipe 152 stops. Hereinafter, refer to Figure 5 and Figure 8 . The following operations and the like are executed by the control device 4 controlling the substrate processing apparatus 1. In other words, the control device 4 is programmed to execute the following operations and the like.

[0187] When the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide water valve 136 are opened at the time T1 shown in Figure 8 , the sulfuric acid-containing liquid is supplied to the SPM nozzle 13 at the first sulfuric acid-containing liquid flow rate, and the hydrogen peroxide water is supplied to the SPM nozzle 13 at the first H2O2 flow rate. Therefore, the sulfuric acid-containing liquid and the hydrogen peroxide water are mixed in the SPM nozzle 13 at the first mixing ratio (first sulfuric acid-containing liquid flow rate / first H2O2 flow rate). Thereby, the first SPM is prepared in the SPM nozzle 13 and is ejected from the SPM nozzle 13 toward the upper surface of the substrate W (first SPM supply step). As a result, a liquid film of the first SPM covering the entire area of the upper surface of the substrate W is formed.

[0188] When a specified time has elapsed after the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide water valve 136 are opened, at Figure 8At the shown time T2, the opening degree of at least one of the sulfuric acid-containing liquid flow rate adjustment valve 59 and the hydrogen peroxide water flow rate adjustment valve 137 is changed, and the sulfuric acid-containing liquid and the hydrogen peroxide water are mixed in the SPM nozzle 13 at a second mixing ratio (second sulfuric acid-containing liquid flow rate / second H2O2 flow rate) greater than the first mixing ratio. Figure 8 An example showing the change in the opening degrees of both the sulfuric acid-containing liquid flow rate adjustment valve 59 and the hydrogen peroxide water flow rate adjustment valve 137 is shown. Thus, the second SPM is prepared in the SPM nozzle 13 and ejected from the SPM nozzle 13 toward the upper surface of the substrate W (second SPM supply step). As a result, the liquid film of the first SPM covering the entire area of the upper surface of the substrate W is replaced with the liquid film of the second SPM covering the entire area of the upper surface of the substrate W.

[0189] At Figure 8 In the shown example, the sulfuric acid-containing liquid is supplied to the SPM nozzle 13 at a second sulfuric acid-containing liquid flow rate greater than the first sulfuric acid-containing liquid flow rate, and the hydrogen peroxide water is supplied to the SPM nozzle 13 at a second H2O2 flow rate less than the first H2O2 flow rate. The second sulfuric acid-containing liquid flow rate and the second H2O2 flow rate can be set in such a way that even if the mixing ratio (ratio of the sulfuric acid-containing liquid to the hydrogen peroxide water) is changed, the flow rate of the SPM ejected from the SPM nozzle 13 can be kept constant, or can be set in such a way that the flow rate of the SPM ejected from the SPM nozzle 13 increases or decreases. The mixing ratio is continuously changed from the first mixing ratio to the second mixing ratio. Therefore, the SPM supplied to the upper surface of the substrate W continuously changes from a state with a higher hydrogen peroxide concentration to a state with a higher concentration of the sulfuric acid-containing liquid.

[0190] When a specified time has elapsed after the mixing ratio of the SPM is changed to the second mixing ratio, at Figure 8 the shown time T5, the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide water valve 136 are closed, and the ejection of the SPM from the SPM nozzle 13 is stopped.

[0191] As Figure 8 shown, the processing susceptor 111 is set to a first facing state in which the innermost first shield 143 among the three shields 143 to 145 faces the peripheral edge surface of the substrate W before the SPM nozzle 13 starts ejecting the first SPM (before the time T1 shown in Figure 8 ). Therefore, the first SPM discharged from the substrate W is received by the inner wall 143a of the first shield 143 and guided to the first susceptor 141 (first SPM capture step). Then, the first SPM in the first susceptor 141 is discharged along the first drain pipe 152 ( Figure 8 the shown drainage is performed, drainage step).

[0192] As Figure 8 shown, at the time point when the mixing ratio of the SPM is changed to the second mixing ratio ( Figure 8At the shown time T2, the first shield 143 is in the upper position. Therefore, the second SPM discharged from the substrate W is received by the inner wall 143a of the first shield 143 and guided to the first susceptor 141. After the mixing ratio of the SPM is changed to the second mixing ratio, the shield lifting unit 146 moves the first shield 143 down to the cleaning height position between the upper position and the lower position at the Figure 8 shown time T3. As a result, the position where the second SPM directly contacts the inner wall 143a of the first shield 143 moves upward relative to the first shield 143.

[0193] For example, after the first shield 143 is stationary at the cleaning height position for a specified time, the shield lifting unit 146 moves the first shield 143 down to the lower position at the Figure 8 shown time T4. Therefore, the processing susceptor 111 is switched to the second facing state in which the second shield 144 faces the peripheral edge of the substrate W in a state where the second SPM is ejected from the SPM nozzle 13 and the entire upper surface area of the substrate W is covered with the liquid film of the second SPM. The second SPM discharged from the substrate W is received by the inner wall 144a of the second shield 144 and guided to the second susceptor 142 (second SPM capturing step). Then, the second SPM in the second susceptor 142 is transported to the recovery tank 21 of the first liquid storage unit 11 via the common pipe 155 and the recovery pipe 156. Thus, the second SPM supplied to the substrate W is recovered (recovery step, Figure 8 the shown recovery is performed).

[0194] When the ejection of the SPM from the SPM nozzle 13 stops at the Figure 8 shown time T5, the shield lifting unit 146 moves the first shield 143 from the lower position up to the upper position at the Figure 8 shown time T6. As a result, the processing susceptor 111 is switched to the first facing state in which the first shield 143 faces the peripheral edge of the substrate W in a state where the ejection of the SPM from the SPM nozzle 13 stops and the entire upper surface area of the substrate W is covered with the liquid film of the SPM. In this state, the rinsing step of supplying the rinsing liquid to the substrate W ( Figure 7 S4) is performed. The drying step of drying the substrate W ( Figure 7 S5) is performed in a state where the processing susceptor 111 is set to the third facing state in which the third shield 145 faces the peripheral edge of the substrate W.

[0195] Figure 9 is a flowchart showing the process when the sulfuric acid-containing liquid and the hydrogen peroxide water are mixed to prepare the SPM and the recovered SPM from the substrate W is supplied to another substrate W. Hereinafter, refer to Figure 5 and Figure 9The following operations and the like are performed by controlling the substrate processing apparatus 1 with the control device 4. In other words, the control device 4 is programmed to perform the following operations and the like.

[0196] As described above, when starting the SPM step ( Figure 7 S3), as Figure 9 shown, the sulfuric acid-containing liquid and hydrogen peroxide water are mixed at a first mixing ratio to prepare a first SPM ( Figure 9 S11). The first SPM is ejected from the SPM nozzle 13 and supplied to the substrate W ( Figure 9 S12). Then, the first SPM discharged from the substrate W is guided to the first drain pipe 152 via the first shield 143 and the first susceptor 141.

[0197] When a specified time has elapsed after starting the ejection of the first SPM, the mixing ratio of the sulfuric acid-containing liquid and hydrogen peroxide water (the ratio of the flow rate of the sulfuric acid-containing liquid before mixing to the flow rate of hydrogen peroxide water before mixing) is increased from the first mixing ratio to the second mixing ratio ( Figure 9 S13). Thereby, the sulfuric acid-containing liquid and hydrogen peroxide water are mixed at the second mixing ratio to prepare a second SPM. Then, the second SPM is supplied to the substrate W ( Figure 9 S14), and is discharged from the substrate W. The second SPM discharged from the substrate W is recovered as a sulfuric acid-containing liquid into the recovery tank 21 of the first liquid storage unit 11 via the second shield 144, the second susceptor 142, the common pipe 155, and the recovery pipe 156 ( Figure 9 S15).

[0198] The sulfuric acid-containing liquid recovered into the recovery tank 21 is transported to the second circulation tank 51 of the second liquid storage unit 12 through the first circulation tank 22 of the first liquid storage unit 11. Since hydrogen peroxide is easily decomposed into water and oxygen at a high temperature, the second SPM (sulfuric acid-containing liquid) recovered into the recovery tank 21 contains water. However, more than half of the components of the second SPM (sulfuric acid-containing liquid) are sulfuric acid. The second SPM (sulfuric acid-containing liquid) recovered into the recovery tank 21 is mixed with the sulfuric acid-containing liquid in the first circulation tank 22 and the sulfuric acid-containing liquid in the second circulation tank 51, and circulates along the second circulation tank 51 and the second circulation pipe 53 (the common pipe 51A and the sulfuric acid-containing liquid circulation pipe 51B). The sulfuric acid concentration of the sulfuric acid-containing liquid circulating in this way is measured by the sulfuric acid concentration meter 64 ( Figure 9 S16). The control device 4 monitors the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation pipe 53 based on the measurement value of the sulfuric acid concentration meter 64 ( Figure 9 S17).

[0199] If the sulfuric acid concentration of the sulfuric acid-containing liquid measured by the sulfuric acid concentration meter 64 is above the lower limit ( Figure 9If it is YES in S17, the control device 4 opens the sulfuric acid-containing liquid valve 60. As a result, the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid distribution pipe 51B flows along the sulfuric acid-containing liquid supply pipe 57 and is supplied to the SPM nozzle 13. As a result, the sulfuric acid-containing liquid made from the second SPM discharged from the substrate W is mixed with hydrogen peroxide water to make a new SPM. Then, this new SPM is supplied to the subsequent substrate W. As a result, the SPM discharged from the substrate W is reused, and thus, the amount of SPM discarded can be reduced.

[0200] On the other hand, when the sulfuric acid concentration of the sulfuric acid-containing liquid measured by the sulfuric acid concentration meter 64 is lower than the lower limit value ( Figure 9 If it is NO in S17), the control device 4 opens the sulfuric acid supply valve 45 installed in the sulfuric acid supply pipe 44 to supply sulfuric acid into the first circulation tank 22 ( Figure 9 S18). By supplementing unused sulfuric acid into the first circulation tank 22, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 increases. Then, the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 is transported to the second circulation tank 51 through the first liquid guide pipe 31. As a result, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation pipe 53 (common pipe 51A and sulfuric acid-containing liquid distribution pipe 51B) increases. Thus, a state where the sulfuric acid concentration of the sulfuric acid-containing liquid circulating in this way is maintained at a high level is maintained.

[0201] In the substrate processing example described using Figures 7 to 9 sulfuric acid-containing liquid and hydrogen peroxide water are mixed to make the first SPM, and the made first SPM is supplied to the substrate W. Moreover, after the supply of the first SPM stops, sulfuric acid-containing liquid and hydrogen peroxide water are mixed to make the second SPM, and the made second SPM is supplied to the substrate W. As a result, the first SPM and the second SPM are supplied to the substrate W to remove the resist from the substrate W.

[0202] When making the first SPM, the sulfuric acid-containing liquid and hydrogen peroxide water are mixed at a first mixing ratio. When making the second SPM, the sulfuric acid-containing liquid and hydrogen peroxide water are mixed at a second mixing ratio. Both the first mixing ratio and the second mixing ratio represent the ratio of the volume of the sulfuric acid-containing liquid before mixing to the volume of the hydrogen peroxide water before mixing. The first mixing ratio is less than the second mixing ratio. Therefore, the hydrogen peroxide concentration contained in the first SPM is higher than the hydrogen peroxide concentration contained in the second SPM.

[0203] Since the hydrogen peroxide concentration is relatively high, the first SPM has a higher removal ability than the second SPM. Therefore, the resist can be efficiently removed from the substrate W. Moreover, after the first SPM is supplied to the substrate W, the second SPM is supplied to the substrate W. Although the removal ability of the second SPM is worse than that of the first SPM, since almost all of the resist is removed from the substrate W by supplying the first SPM, only the relatively easily removable resist remains on the substrate W. In addition, since the temperature of the SPM (the second SPM) supplied to the substrate W is adjusted to a very high temperature (about 190°C to about 220°C), it has a removal ability that is still relatively high although it is worse than that of the first SPM. Through these, the second SPM with a relatively poor removal ability can also surely remove the resist from the substrate W.

[0204] The first SPM discharged from the substrate W flows into the first drain pipe 152 instead of the recovery pipe 156. The hydrogen peroxide concentration in the first SPM discharged from the substrate W is relatively high, and the sulfuric acid concentration is relatively low. Moreover, the first SPM discharged from the substrate W contains a large amount of contaminants (carbides of the resist, etc.) generated by the reaction of the first SPM with the resist. Therefore, the first SPM discharged from the substrate W is not suitable for recovery.

[0205] On the other hand, the sulfuric acid concentration in the second SPM discharged from the substrate W is relatively high. Furthermore, the amount of contaminants contained in the second SPM discharged from the substrate W is less than the amount of contaminants contained in the first SPM discharged from the substrate W. Therefore, the second SPM with a relatively high sulfuric acid concentration and a small amount of contaminants is guided to the recovery pipe 156 and remixed with the hydrogen peroxide water. As a result, the sulfuric acid contained in the second SPM reacts with the hydrogen peroxide water to produce a new SPM. Therefore, the amount of SPM discarded can be reduced.

[0206] In this way, when the sulfuric acid concentration, that is, the ratio of the volume of sulfuric acid before mixing to the volume of sulfuric acid and hydrogen peroxide water before mixing, is large, since the SPM is recovered, an SPM with a relatively high sulfuric acid concentration can be recovered. Furthermore, instead of maintaining a large sulfuric acid concentration state, before starting to recover the SPM, an SPM with a relatively high hydrogen peroxide concentration and sufficient removal ability is supplied to the substrate W. Therefore, the resist can be efficiently removed from the substrate W. Therefore, the resist can be efficiently removed from the substrate W, and the SPM with a relatively high sulfuric acid concentration can be recovered.

[0207] In this substrate processing example, the first SPM discharged from the substrate W is received by the first shield 143 surrounding the substrate W. The second SPM discharged from the substrate W is received by the second shield 144 surrounding the substrate W. The first SPM received by the first shield 143 flows into the first drain pipe 152 connected to the first shield 143. The second SPM received by the second shield 144 flows into the recovery pipe 156 connected to the second shield 144.

[0208] The first SPM discharged from the substrate W contains a large amount of contaminants. Therefore, there are cases where contaminants remain on the inner peripheral surface of the first shield 143 after the first shield 143 receives the first SPM. There are cases where when the second SPM discharged from the substrate W is received and recovered by the first shield 143, the contaminants attached to the first shield 143 are mixed into the second SPM. Therefore, by having the second shield 144 different from the first shield 143 receive the second SPM, the amount of contaminants contained in the recovered SPM can be reduced.

[0209] In this substrate processing example, the first SPM discharged from the substrate W when the supply of the first SPM stops is received by the first shield 143. Then, the states of the first shield 143 and the second shield 144 are switched from the first facing state to the second facing state, and the second SPM discharged from the substrate W is received by the second shield 144. That is, after the discharge of the first SPM with a relatively high content of contaminants ends, the first shield 143 is switched from the state directly facing the substrate W to the state where the second shield 144 directly faces the substrate W. Thereby, it is possible to prevent the second shield 144 from being contaminated by the first SPM with a relatively high content of contaminants.

[0210] Figure 10 It is a graph showing the change in the sulfuric acid concentration of the recovered sulfuric acid-containing liquid. Figure 10 The vertical axis in [it] represents the sulfuric acid concentration of the recovered sulfuric acid-containing liquid. Figure 10 The horizontal axis in [it] represents the number of substrates W processed by the substrate processing apparatus 1. Figure 10 The ratios X, Y, and Z in [it] all represent the ratios of the flow rates of the sulfuric acid-containing liquid when the flow rate of hydrogen peroxide water is set to 1. Ratio X is greater than ratio Y, and ratio Y is greater than ratio Z (ratio X > ratio Y > ratio Z).

[0211] Observe Figure 10It can be seen that when the ratio of the sulfuric acid-containing liquid is any one of ratio X, ratio Y, and ratio Z, the sulfuric acid concentration of the sulfuric acid-containing liquid decreases as the number of processed substrates W increases. The rate of decrease in sulfuric acid concentration is greater when the ratio of the sulfuric acid-containing liquid is smaller. That is to say, when the ratio of the sulfuric acid-containing liquid is ratio Z, the rate of decrease in the sulfuric acid concentration in the sulfuric acid-containing liquid is the largest, and when the ratio of the sulfuric acid-containing liquid is ratio Y, the rate of decrease in the sulfuric acid concentration in the sulfuric acid-containing liquid is the second largest. In other words, if the ratio of the sulfuric acid-containing liquid is relatively high, then the sulfuric acid concentration in the sulfuric acid-containing liquid is not easily reduced. When the ratio of the sulfuric acid-containing liquid is ratio X, it is confirmed that even when recovering the SPM supplied to the substrate W and processing more than 100 substrates W, the sulfuric acid concentration of the sulfuric acid-containing liquid only decreases to about 90%.

[0212] As described above, in the present embodiment, the SPM with a relatively high sulfuric acid concentration in the sulfuric acid-containing liquid is recovered into the sulfuric acid-containing liquid supply device 8, and the recovered SPM is reused as the sulfuric acid-containing liquid. Observation Figure 10 It can be seen that the smaller the ratio of the sulfuric acid-containing liquid, the greater the rate of decrease in sulfuric acid concentration. Therefore, if the ratio of the sulfuric acid-containing liquid recovered into the sulfuric acid-containing liquid supply device 8 is relatively large, then even when processing multiple substrates W, the sulfuric acid concentration in the sulfuric acid-containing liquid is not easily reduced. Therefore, the sulfuric acid concentration of the sulfuric acid-containing liquid recovered into the sulfuric acid-containing liquid supply device 8 can be maintained at a value suitable for reuse. Thereby, the frequency of replacing the sulfuric acid-containing liquid in the first circulation tank 22 and the second circulation tank 51 with new sulfuric acid, or the frequency of replenishing new sulfuric acid into the first circulation tank 22, can be reduced. Therefore, the consumption amount of sulfuric acid (i.e., the waste amount of sulfuric acid) can be reduced.

[0213] Through the above, according to the present embodiment, in the sulfuric acid-containing liquid supply device 8, a liquid storage part (first liquid storage part 11) for sulfuric acid concentration adjustment and a liquid storage part (second liquid storage part 12) for temperature adjustment are separately provided. Since the temperature of the replenished sulfuric acid is room temperature, if the sulfuric acid-containing liquid is temperature-adjusted while replenishing sulfuric acid in the second liquid storage part 12 for temperature adjustment, the temperature of the sulfuric acid-containing liquid in the liquid storage part is unstable. In the present embodiment, since the first liquid storage part 11 for sulfuric acid concentration adjustment and the second liquid storage part 12 for temperature adjustment are separately provided, the temperature of the sulfuric acid-containing liquid in the second liquid storage part 12 is stable. Thereby, the sulfuric acid-containing liquid supplied to the SPM nozzle 13 can be adjusted to a desired high temperature.

[0214] In the present embodiment, the sulfuric acid-containing liquid is heated by the second and first circulation heaters 52 and 24 in the first liquid storage unit 11 and the second liquid storage unit 12, respectively. Therefore, more heat can be imparted to the sulfuric acid-containing liquid. In addition, the sulfuric acid-containing liquid adjusted to the first temperature (about 120°C to about 130°C) in the first liquid storage unit 11 is supplied to the second liquid storage unit 12. Moreover, in the second liquid storage unit 12, the sulfuric acid-containing liquid is heated and raised to the second temperature (about 160°C). That is, the sulfuric acid-containing liquid is heated step by step. Therefore, the sulfuric acid-containing liquid can be raised to a higher temperature in the second liquid storage unit 12.

[0215] In addition, the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation pipe 53 is guided to the sulfuric acid-containing liquid supply pipe 57. Then, the sulfuric acid-containing liquid flowing along the sulfuric acid-containing liquid supply pipe 57 is heated by the heater 54. By the heating by the heater 54, the sulfuric acid-containing liquid can be raised to a third temperature (about 165°C) higher than when circulating along the second circulation tank 51 and the second circulation pipe 53.

[0216] The removal ability of the second SPM with the second mixing ratio of SPM is poorer than that of the first SPM. However, the removal ability of SPM depends not only on the hydrogen peroxide concentration but also on the temperature of the SPM. That is, the removal ability of SPM increases as the temperature of the SPM becomes higher. Moreover, as the temperature of the sulfuric acid-containing liquid becomes higher, the temperature of the mixed SPM becomes higher. Therefore, by increasing the temperature of the sulfuric acid-containing liquid before mixing, even if the mixing ratio is the second mixing ratio, the removal ability of SPM can be maintained at a high level. Thus, even if the mixing ratio is the second mixing ratio, the resist can be removed from the substrate W with good efficiency.

[0217] In the present embodiment, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation pipe 53 is measured by the sulfuric acid concentration meter 64. Therefore, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation pipe 53 can be accurately obtained. Moreover, when the sulfuric acid concentration measured by the sulfuric acid concentration meter 64 is lower than the lower limit value, sulfuric acid is supplied to the first circulation tank 22 by the sulfuric acid supply unit 25. Thereby, the sulfuric acid concentration of the sulfuric acid-containing liquid supplied to the SPM nozzle 13 can be adjusted to a desired high concentration.

[0218] In the present embodiment, since both the first circulation heater 24 and the second circulation heater 52 are used to heat the sulfuric acid-containing liquid, the burden imposed on the second circulation heater 52 can be reduced as compared with the case where only the second circulation heater 52 is used to heat the sulfuric acid-containing liquid.

[0219] Figure 11 FIG. is a view obtained by observing the first sulfuric acid-containing liquid supply device 209 according to the second embodiment of the present invention in the horizontal direction. InFigure 11 Among them, components equivalent to those shown are labeled with the same reference numerals and their descriptions are omitted. Figures 1 to 10 and Figure 1 so on.

[0220] The difference between the first sulfuric acid-containing liquid supply device 209 of the second embodiment and the first sulfuric acid-containing liquid supply device 9 of the first embodiment is that, in addition to the first liquid storage part, a third liquid storage part 213 is provided. The sulfuric acid-containing liquid is transported from the first liquid storage part to the third liquid storage part 213, and the sulfuric acid-containing liquid stored in the third liquid storage part 213 is transported to the second liquid storage part 12.

[0221] In addition, the difference between the first liquid storage part 211 and the first liquid storage part 11 of the first embodiment is that the first circulation heater 24 is abolished. In addition, the first liquid storage part 211 does not have a drain tank 50. That is to say, in the first liquid storage part 211, a unit for heating the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 is not provided.

[0222] The SPM recovered into the recovery tank 21 is stored as a sulfuric acid-containing liquid in the recovery tank 21. The SPM discharged from the substrate W is cooled while flowing along the processing chuck 111, the recovery pipe 156, and the recovery lead-out pipe 26, and then recovered into the recovery tank 21. Therefore, the temperature of the SPM recovered into the recovery tank 21 is much lower than the temperature of the SPM supplied to the substrate W (about 190°C to about 220°C). Nevertheless, it still has a relatively high liquid temperature of about 80°C to about 90°C.

[0223] The sulfuric acid-containing liquid stored in the recovery tank 21 is transported to the first circulation tank 22 via the transfer pipe 28 by driving the first liquid feeding device 29. Then, the sulfuric acid-containing liquid circulates along the first circulation tank 22 and the first circulation pipe 23. During the flow of the sulfuric acid-containing liquid along the transfer pipe 28 and the first circulation pipe 23, heat is taken away by the pipe walls of the transfer pipe 28 and the first circulation pipe 23, so the temperature of the sulfuric acid-containing liquid drops. The sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 can be maintained at a temperature higher than room temperature (about 23°C to about 25°C) but lower than the fourth temperature (about 40°C to about 60°C) of the sulfuric acid-containing liquid stored in the recovery tank 21 through the heat balance with the pipe wall of the first circulation pipe 23.

[0224] The third liquid storage part 213 included in the first sulfuric acid-containing liquid supply device 209 includes a third circulation tank (the third tank) 222, a third circulation pipe (the third pipe) 223, and a third circulation heater (the second heater) 224.

[0225] The downstream end of the first liquid guiding pipe 31 is connected to the third circulation tank 222. Sulfuric acid-containing liquid at a fourth temperature (for example, about 40°C to about 60°C) in the first liquid storage part 211 is guided to the third circulation tank 222. Moreover, the guided sulfuric acid-containing liquid is stored in the third circulation tank 222 (third storage step).

[0226] The third circulation tank 222 is connected to a second liquid guiding pipe 231 extending toward the second sulfuric acid-containing liquid supply device 10 (second liquid storage part 12). The downstream end of the second liquid guiding pipe 231 is connected to the second circulation tank 51 of the second liquid storage part 12. In the middle part of the second liquid guiding pipe 231, a fifth liquid feeding device 232 such as a pump for sucking the sulfuric acid-containing liquid in the third circulation tank 222 is interposed. In the middle part of the second liquid guiding pipe 231, a fourth capture filter 237 and an on-off valve 238 are interposed on the downstream side of the fifth liquid feeding device 232. The fourth capture filter 237 is a filter for capturing and removing relatively small foreign matters contained in the sulfuric acid-containing liquid flowing through the second liquid guiding pipe 231. The fourth capture filter 237 removes the foreign matters not completely removed by the third capture filter 37.

[0227] The on-off valve 238 is a valve for controlling the flow and stop of the sulfuric acid-containing liquid in the second liquid guiding pipe 231.

[0228] In the second liquid guiding pipe 231, a reflux pipe 240 is branched and connected between the on-off valve 238 and the fourth capture filter 237. The downstream end of the reflux pipe 240 extends toward the third circulation tank 222. A reflux valve 241 is interposed in the middle part of the reflux pipe 240. The upstream side part of the branch position 242 of the reflux pipe 240 in the second liquid guiding pipe 231 and the reflux pipe 240 form a third circulation pipe 223.

[0229] During the operation of the substrate processing device (including the period when the processing of the substrate W is stopped), the fifth liquid feeding device 232 and the third circulation heater 224 are always driven. Therefore, by closing the on-off valve 238 and opening the reflux valve 241, the sulfuric acid-containing liquid sucked from the third circulation tank 222 flows along the second liquid guiding pipe 231 to the branch position 242, and returns from the branch position 242 to the third circulation tank 222 through the reflux pipe 240. That is, during the period when the sulfuric acid-containing liquid is not transported to the second liquid storage part 12, the sulfuric acid-containing liquid circulates along the third circulation tank 222 and the third circulation pipe 223. Moreover, when it is time to transport the sulfuric acid-containing liquid to the second liquid storage part 12, by opening the on-off valve 238 and closing the reflux valve 241, the sulfuric acid-containing liquid sucked from the third circulation tank 222 is supplied to the second liquid storage part 12 through the second liquid guiding pipe 231.

[0230] The third circulation heater 224 is installed on the upstream side of the fifth liquid feeding device 232 in the middle part of the second liquid guiding pipe 231. The third circulation heater 224 heats the sulfuric acid-containing liquid circulating along the third circulation tank 222 and the third circulation pipe 223 (the third heating step). The heating temperature of the third circulation heater 224 is set to a specified first temperature (the second heating temperature, for example, about 120°C to about 130°C). By circulating the sulfuric acid-containing liquid along the third circulation tank 222 and the third circulation pipe 223, the sulfuric acid-containing liquid is adjusted to the first temperature. During the period when the sulfuric acid-containing liquid is not fed to the second liquid storage part 12, by previously circulating the sulfuric acid-containing liquid, the sulfuric acid-containing liquid adjusted to the first temperature can be stored in the third circulation tank 222 in advance. In addition, after the opening and closing valve 238 can be opened, the sulfuric acid-containing liquid adjusted to the first temperature can be fed to the second liquid storage part 12.

[0231] The third liquid storage part 213 includes a drain pipe 246, a drain valve 247, a lead-out pipe 248, a sixth liquid feeding device 249, and a drain tank 250. The drain pipe 246, the drain valve 247, the lead-out pipe 248, the sixth liquid feeding device 249, and the drain tank 250 respectively have the same constitution and function as the drain pipe 46, the drain valve 47, the lead-out pipe 48, the third liquid feeding device 49, and the drain tank 50.

[0232] In this second embodiment, in addition to the above-described first embodiment, the following effects are also exhibited.

[0233] That is to say, in the first liquid storage part 211, no unit is provided for heating the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23. That is to say, the heating of the sulfuric acid-containing liquid is not performed in the first liquid storage part 211. Therefore, the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 has a relatively low temperature (about 40°C to about 60°C). Therefore, the temperature of the sulfuric acid-containing liquid passing through the third capture filter 37 is relatively low.

[0234] As in the first embodiment, when the high-temperature (about 120°C to about 130°C) sulfuric acid-containing liquid flows along the first circulation tank 22 and the first circulation pipe 23, there is a concern that as the high-temperature (about 120°C to about 130°C) sulfuric acid-containing liquid continues to flow through the third capture filter 37, the filter will expand, and thus the diameter of each hole 71 (see Figure 3 ) will increase. If the diameter of each hole 71 (see Figure 3 ) increases, the diameter of the foreign matter that the third capture filter 37 can capture becomes larger. Therefore, there is a concern that the filtering performance of the third capture filter 37 will deteriorate and the foreign matter contained in the sulfuric acid-containing liquid cannot be captured well in the first liquid storage part.

[0235] In the second embodiment, the temperature of the sulfuric acid-containing liquid passing through the third capture filter 37 is relatively low (about 40 to about 60°C). Therefore, a decrease in the filtration performance of the third capture filter 37 can be suppressed. As a result, foreign matter contained in the sulfuric acid-containing liquid can be satisfactorily captured in the first liquid storage section 211. Thereby, a clean sulfuric acid-containing liquid can be supplied to the SPM nozzle 13.

[0236] In the second embodiment, in the third liquid storage section 213, the sulfuric acid-containing liquid transported from the first liquid storage section 211 circulates along the third circulation tank 222 and the third circulation pipe 223. The sulfuric acid-containing liquid circulating along the third circulation tank 222 and the third circulation pipe 223 is heated by the third circulation heater 224. The sulfuric acid-containing liquid is heated by the third circulation heater 224 and the second circulation heater 52 in the third liquid storage section 213 and the second liquid storage section 12, respectively. Since more heat can be imparted to the sulfuric acid-containing liquid, the temperature of the sulfuric acid-containing liquid can be raised to a higher temperature in the second liquid storage section 12.

[0237] In addition, since the sulfuric acid-containing liquid is heated using both the third circulation heater 224 and the second circulation heater 52, the burden imposed on one heater (i.e., the second circulation heater 52) can be reduced.

[0238] Figure 12 FIG. is a view obtained by observing the first sulfuric acid-containing liquid supply device 309 according to the third embodiment of the present invention in the horizontal direction. In Figure 12 , components equivalent to those shown in Figures 1 to 10 are denoted by the same reference numerals as Figure 1 and so on, and their description is omitted.

[0239] The difference between the first liquid storage section 311 of the first sulfuric acid-containing liquid supply device 309 according to the third embodiment and the first liquid storage section 11 of the first sulfuric acid-containing liquid supply device 9 according to the first embodiment is that the first circulation heater 24 is abolished. In other respects, the configuration of the first liquid storage section 311 is equivalent to that of the first liquid storage section 11.

[0240] As described above, the SPM recovered into the recovery tank 21 is much lower in temperature (about 190°C to about 220°C) than the SPM supplied to the substrate W. Nevertheless, it has a relatively high liquid temperature of about 80°C to about 90°C. As described above, the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 can be maintained at a temperature higher than room temperature (about 23°C to about 25°C) but lower than the temperature of the sulfuric acid-containing liquid stored in the recovery tank 21 (about 40°C to about 60°C) by thermal equilibrium with the pipe wall of the first circulation pipe 23. Moreover, the fourth sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 is transported to the second liquid storage section 12 of the second sulfuric acid-containing liquid supply device 10.

[0241] Moreover, in the second liquid storage unit 12, the sulfuric acid-containing liquid circulated along the second circulation tank 51 and the second circulation pipe 53 is heated by the second circulation heater 52, whereby the temperature of the circulated sulfuric acid-containing liquid is raised to the second temperature.

[0242] In the third embodiment, since the temperature of the sulfuric acid-containing liquid passing through the third capture filter 37 is relatively low (about 40 to about 60 °C), it is possible to suppress a decrease in the filtration performance of the third capture filter 37. Therefore, foreign matters contained in the sulfuric acid-containing liquid can be satisfactorily captured in the first liquid storage unit 311. Thereby, a clean sulfuric acid-containing liquid can be supplied to the SPM nozzle 13.

[0243] As described above, three embodiments of the present invention have been described, but the present invention can also be implemented in other ways.

[0244] For example, in the second and third embodiments, as Figure 11 and Figure 12 shown by the dashed line, the first liquid storage units 211 and 311 may also include a cooler 401 that cools the sulfuric acid-containing liquid circulated along the first circulation tank 22 and the first circulation pipe 23. The cooler 401 is interposed, for example, in the middle of the first liquid guiding pipe 31 on the upstream side of the second liquid feeding device 32. In this case, the sulfuric acid-containing liquid is cooled by the circulation of the sulfuric acid-containing liquid in the first circulation tank 22 and the first circulation pipe 23. Depending on the setting of the cooling temperature based on the cooler 401, the sulfuric acid-containing liquid circulated along the first circulation tank 22 and the first circulation pipe 23 can also be reduced to room temperature (about 23 °C to about 25 °C) or a low temperature lower than room temperature.

[0245] Figure 13 is a diagram for explaining the change in the filtration performance of the capture filter (the third capture filter 37) caused by heat influence. As Figure 13As shown, as the temperature of the sulfuric acid-containing liquid (circulation temperature) passing through the capture filter (the third capture filter 37) becomes lower, the filtering performance of the capture filter improves (that is, relatively small foreign substances (fine particles) can be captured well). If the number of fine particles passing through when the temperature of the sulfuric acid-containing liquid passing through the capture filter is set lower than the temperature of the sulfuric acid-containing liquid stored in the recovery tank (temperature A) is taken as the reference (100%), then when the temperature of the sulfuric acid-containing liquid passing through the capture filter is reduced to room temperature (temperature B), the number of fine particles passing through becomes 40%, and the filtering performance becomes better. On the other hand, although not shown, when the temperature of the sulfuric acid-containing liquid is 80°C or higher, the number of fine particles passing through increases significantly compared to the reference (100%), and the filtering performance deteriorates. Therefore, by providing the cooler 401, relatively small foreign substances contained in the sulfuric acid-containing liquid can be captured better in the first liquid storage parts 211 and 311. Thus, a cleaner sulfuric acid-containing liquid can be supplied to the SPM nozzle 13.

[0246] In addition, as Figure 4 shown by the dashed line in the figure, the second liquid storage part 12 may also include a sulfuric acid supply unit 402 that supplies new sulfuric acid (sulfuric acid not yet used for the treatment of the substrate W) to the second circulation tank 51. The sulfuric acid supply unit 402 includes a sulfuric acid supply pipe 403 that replenishes sulfuric acid to the second circulation tank 51, and a sulfuric acid replenishment valve 404 that opens and closes the sulfuric acid supply pipe 403. The sulfuric acid supplied to the sulfuric acid supply pipe 403 is unused sulfuric acid (for example, concentrated sulfuric acid).

[0247] The supply of sulfuric acid from the sulfuric acid supply unit 402 is not used for the replenishment of sulfuric acid, and the replenishment of sulfuric acid is used to increase the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation pipe 53. It is specifically used to accumulate the sulfuric acid-containing liquid in the second circulation tank 51 when the substrate processing apparatus 1 starts up, etc.

[0248] In addition, the case where the nozzle internal mixing method in which the sulfuric acid-containing liquid and hydrogen peroxide water are mixed inside the SPM nozzle 13 has been described, but a pipe internal mixing method in which the sulfuric acid-containing liquid and hydrogen peroxide water are mixed in the processing liquid pipe connected to the nozzle or in the mixing pipe connected to the processing liquid pipe may also be adopted.

[0249] In addition, it has been described that in the first liquid storage parts 11, 211, and 311, the SPM recovered from the recovery lead-out pipe 26 is temporarily recovered in the recovery tank 21 and then stored in the first circulation tank 22, but it may also be directly stored in the first circulation tank 22 without passing through the recovery tank 21. In this case, the recovery tank 21 may also be abolished.

[0250] In addition, instead of disposing the sulfuric acid concentration meters 64 in only one of the sulfuric acid-containing liquid flow pipes 51B corresponding to the respective towers, they may be disposed in all of them. Alternatively, instead of disposing the sulfuric acid concentration meters 64 in the sulfuric acid-containing liquid flow pipes 51B, they may be disposed in the second circulation tank 51 and / or the common pipe 51A. Regarding the sulfuric acid concentration of the sulfuric acid-containing liquid produced by the sulfuric acid-containing liquid supply device 8, instead of or in combination with measuring the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation pipe 53, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 may be measured.

[0251] In addition, one sulfuric acid-containing liquid supply device composed of one first sulfuric acid-containing liquid supply device 9 and one second sulfuric acid-containing liquid supply device 10 may supply the sulfuric acid-containing liquid not to the treatment units 6 included in a plurality of (three) towers but only to the treatment units 6 included in one tower. That is to say, the pairs of the first circulation tank 22 and the second circulation tank 51 may also be provided in one-to-one correspondence with the towers of the treatment units 6. In this case, the configuration of the common pipe 51A may be omitted, and both ends of the sulfuric acid-containing liquid flow pipe 51B are connected to the second circulation tank 51. That is to say, the second circulation pipe 53 may be composed only of the sulfuric acid-containing liquid flow pipe 51B.

[0252] In the present embodiment, the first liquid storage units 11, 211, 311 and / or the third liquid storage unit 213 may be commonly disposed in the clean room (that is, on the same floor as the second liquid storage unit 12) instead of being disposed on a floor different from the second liquid storage unit 12. In this case, the first liquid storage units 11, 211, 311 and / or the third liquid storage unit 213 and the second liquid storage unit 12 may be housed and disposed in a common frame instead of being respectively housed and disposed in different frames.

[0253] In addition, in each of the above embodiments, the case where the substrate processing device 1 is a device for processing a substrate W including a semiconductor wafer has been described. However, the substrate processing device may also be a device for processing substrates such as substrates for liquid crystal display devices, substrates for flat panel display (FPD) devices such as organic EL (electroluminescence) display devices, substrates for optical discs, substrates for magnetic discs, substrates for magneto-optical discs, substrates for photomasks, ceramic substrates, and substrates for solar cells.

[0254] In addition, various design changes may be implemented within the scope of the matters described in the claims.

[0255] This application corresponds to Japanese Patent Application No. 2018-176394 filed with the Japan Patent Office on September 20, 2018, and all disclosures of this application are incorporated herein by reference.

[0256] [Description of Symbols]

[0257] 1 Substrate processing device

[0258] 4 Control device

[0259] 6 Processing unit

[0260] 8 Sulfuric acid-containing liquid supply device

[0261] 11 First liquid storage section

[0262] 12 Second liquid storage section

[0263] 13 SPM nozzle (nozzle)

[0264] 13a Inside of SPM nozzle (mixing section)

[0265] 22 First circulation tank (first tank)

[0266] 23 First circulation pipe (second pipe)

[0267] 24 First circulation heater (second heater)

[0268] 25 Sulfuric acid replenishing unit

[0269] 37 Third capture filter (filter)

[0270] 51 Second circulation tank (second tank)

[0271] 52 Second circulation heater (first heater)

[0272] 53 Second circulation pipe (first pipe)

[0273] 54 Heater (third heater)

[0274] 59 Sulfuric acid-containing liquid flow rate adjustment valve (mixing ratio change unit)

[0275] 64 Sulfuric acid concentration meter

[0276] 108 Rotating chuck (substrate holding unit)

[0277] 122 Hydrogen peroxide water supply unit

[0278] 137 Hydrogen peroxide water flow rate adjustment valve (mixing ratio change unit)

[0279] 143 First shield

[0280] 144 Second shield

[0281] 146 Shield lifting unit (shield switching unit)

[0282] 156 Recovery pipe

[0283] 157 Second drain pipe (drain pipe)

[0284] 209 First sulfuric acid-containing liquid supply device

[0285] 211 First liquid storage part

[0286] 213 Third liquid storage part

[0287] 222 Third circulation tank (third tank)

[0288] 223 Third circulation pipe (third pipe)

[0289] 224 Third circulation heater (third heater)

[0290] 248 Discharge pipe

[0291] 309 First sulfuric acid-containing liquid supply device

[0292] 311 First liquid storage part

[0293] 401 Cooler

[0294] W substrate.

Claims

1. A substrate processing apparatus that removes a resist from a substrate using SPM which is a mixed solution of sulfuric acid and hydrogen peroxide water, and includes: a substrate holding unit that holds a substrate; a nozzle having a discharge port and discharging SPM from the discharge port toward the substrate held by the substrate holding unit; a mixing unit that communicates with the discharge port; a sulfuric acid-containing liquid supply device that recovers the liquid supplied to and discharged from the substrate held by the substrate holding unit, manufactures a sulfuric acid-containing liquid based on the recovered liquid, and supplies the manufactured sulfuric acid-containing liquid to the mixing unit; a hydrogen peroxide water supply unit that supplies hydrogen peroxide water to the mixing unit; and a control device that controls the sulfuric acid-containing liquid supply device and the hydrogen peroxide water supply unit; the sulfuric acid-containing liquid supply device includes a first liquid storage unit and a second liquid storage unit, the first liquid storage unit includes: a first tank that stores the recovered liquid; and a sulfuric acid replenishing unit that replenishes sulfuric acid to the first tank; the second liquid storage unit includes: a second tank that stores the liquid transferred from the first tank; a first pipe having both ends connected to the second tank for circulating the liquid stored in the second tank; and a first heater that heats the liquid circulating along the second tank and the first pipe; the first liquid storage unit further includes: a second pipe having both ends connected to the first tank for circulating the sulfuric acid-containing liquid stored in the first tank; and a second heater that heats the sulfuric acid-containing liquid circulating along the first tank and the second pipe; the control device executes: a sulfuric acid-containing liquid manufacturing step of recovering the SPM supplied to and discharged from the substrate to manufacture a sulfuric acid-containing liquid; and an SPM discharging step of generating SPM by supplying the manufactured sulfuric acid-containing liquid and hydrogen peroxide water to the mixing unit and mixing the sulfuric acid-containing liquid and hydrogen peroxide water in the mixing unit, and discharging the generated SPM from the discharge port, the control device executes in the sulfuric acid-containing liquid manufacturing step: a first storage step of recovering the SPM discharged from the substrate and storing it as a sulfuric acid-containing liquid in the first tank; a sulfuric acid replenishing step of replenishing sulfuric acid to the first tank through the sulfuric acid replenishing unit; a second storage step of storing the sulfuric acid-containing liquid transferred from the first tank in the second tank; a first heating step of heating the sulfuric acid-containing liquid circulating along the second tank and the first pipe by the first heater; and a second heating step of heating the sulfuric acid-containing liquid circulating along the first tank and the second pipe by the second heater; and the control device executes a step of supplying the sulfuric acid-containing liquid circulating along the second tank and the first pipe to the mixing unit in the SPM discharging step.

2. The substrate processing apparatus according to claim 1, wherein the second liquid storage unit further includes a sulfuric acid concentration meter, the sulfuric acid concentration meter measures the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second tank and the first pipe, and the control device executes the sulfuric acid replenishing step when the measured value obtained by using the sulfuric acid concentration meter is less than a specified determination value.

3. The substrate processing apparatus according to claim 1, wherein the heating temperature of the first heater, i.e., the first heating temperature, is higher than the heating temperature of the second heater, i.e., the second heating temperature.

4. The substrate processing apparatus according to claim 1, further comprising: a sulfuric acid-containing liquid supply pipe connecting the second tank or the first pipe to the mixing section; and a third heater for heating the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid supply pipe; and the control device further performs a third heating step in the sulfuric acid-containing liquid preparation step, the third heating step heating the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid supply pipe by the third heater.

5. A substrate processing method performed in a substrate processing apparatus including a nozzle, a mixing section, a first liquid storage section, and a second liquid storage section, the nozzle spraying SPM, which is a mixed liquid of sulfuric acid and hydrogen peroxide water, from a spray outlet toward a substrate held by a substrate holding unit, the mixing section communicating with the spray outlet, the first liquid storage section having a first tank, the second liquid storage section having a second tank different from the first tank, and the substrate processing method including: a sulfuric acid-containing liquid preparation step of recovering SPM supplied to a substrate held by the substrate holding unit and at least partially covered with a resist and discharged from the substrate to prepare a sulfuric acid-containing liquid; and an SPM spraying step of supplying the prepared sulfuric acid-containing liquid and hydrogen peroxide water to the mixing section, thereby mixing the sulfuric acid-containing liquid and hydrogen peroxide water in the mixing section to generate SPM and spraying the generated SPM from the spray outlet, the sulfuric acid-containing liquid preparation step including the following steps: recovering the SPM discharged from the substrate and storing it as a sulfuric acid-containing liquid in the first tank of the first liquid storage section; a sulfuric acid replenishment step of replenishing sulfuric acid to the first tank; storing the sulfuric acid-containing liquid transported from the first tank in the second tank of the second liquid storage section; and a heating step of heating the sulfuric acid-containing liquid circulating along the second tank and a first pipe connected to both ends of the second tank by a first heater of the second liquid storage section; and the SPM spraying step includes a step of supplying the sulfuric acid-containing liquid circulating along the second tank and the first pipe to the mixing section, the first liquid storage section further includes: a second pipe connected to both ends of the first tank for circulating the sulfuric acid-containing liquid stored in the first tank; and a second heater for heating the sulfuric acid-containing liquid circulating along the first tank and the second pipe; and the sulfuric acid-containing liquid preparation step further includes a second heating step of heating the sulfuric acid-containing liquid circulating along the first tank and the second pipe by the second heater.

6. The substrate processing method according to claim 5, wherein the second liquid storage section includes a sulfuric acid concentration meter for measuring the sulfuric acid concentration of the sulfuric acid-containing liquid circulating along the second tank and the first pipe, and the sulfuric acid replenishment step is performed when the measured value obtained by the sulfuric acid concentration meter is less than a specified determination value.

7. The substrate processing method according to claim 5, wherein the heating temperature of the first heater, i.e., the first heating temperature, is higher than the heating temperature of the second heater, i.e., the second heating temperature.

8. The substrate processing method according to claim 5, wherein the substrate processing apparatus further comprises: a sulfuric acid-containing liquid supply pipe connecting the second tank or the first pipe to the mixing section; and a third heater for heating the sulfuric acid-containing liquid flowing along the sulfuric acid-containing liquid supply pipe; and the sulfuric acid-containing liquid preparation step further comprises a third heating step of heating the sulfuric acid-containing liquid flowing along the sulfuric acid-containing liquid supply pipe by the third heater.

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