Substrate processing apparatus and substrate processing method

Abstract

The invention relates to a substrate processing apparatus and a substrate processing method. The substrate processing apparatus includes: a nozzle having a discharge port and discharging SPM toward a substrate from the discharge port; the mixing part is communicated with the ejection opening; a sulfuric acid-containing liquid supply device for recovering the liquid supplied to the substrate held by the substrate holding unit and discharged from the substrate, preparing a sulfuric acid-containing liquid on the basis of the recovered liquid, and supplying the prepared sulfuric acid-containing liquid to the mixing unit; and a control device. Furthermore, the control device executes: a sulfuric acid-containing liquid preparation step of recovering the SPM supplied to the substrate and discharged from the substrate to prepare a sulfuric acid-containing liquid; and an SPM discharge step of generating SPM by supplying the prepared 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

[0001] Information about divisional applications

[0002] This application is a divisional application. The parent application is an invention patent application filed on July 18, 2019, with application number 201980061522.3 and title “Substrate Processing Apparatus and Substrate Processing Method.” Technical Field

[0003] 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 displays (LCDs), substrates for FPDs (flat panel displays) such as organic EL (electroluminescence) displays, substrates for optical disks, magnetic disks, magneto-optical disks, photomask substrates, ceramic substrates, and solar cell substrates. Background Art

[0004] In the manufacturing process of semiconductor devices, liquid crystal display devices, and the like, a substrate processing apparatus is used to process a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display device.

[0005] Patent Document 1 below discloses a single-wafer substrate processing apparatus that processes substrates one by one. This substrate processing apparatus comprises a spin chuck that rotates while holding a substrate horizontally, and a nozzle that sprays SPM (a mixture of sulfuric acid and hydrogen peroxide) toward the substrate held by the spin chuck. Patent Document 1 discloses a configuration in which the SPM used in substrate processing is recovered and reused for subsequent processing.

[0006] Background Art Literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-024793 Summary of the Invention

[0009] [Problems to be solved by the invention]

[0010] In Patent Document 1, SPM recovered from a processing chamber housing a rotary chuck is recovered to a recovery tank through a recovery pipeline. The SPM stored in the recovery tank is supplied to a circulation tank after foreign matter contained in the SPM is removed by a filter. The circulation tank is connected to an SPM supply pipe extending toward the SPM nozzle. A pump is installed in the middle of the SPM supply pipe. In addition, a filter, a heater, and an ejection valve are installed in the middle of the SPM supply pipe on the downstream side of the pump. The SPM supply pipe is branched and connected to the SPM loop pipe between the heater and the ejection valve. The front end of the SPM loop pipe extends toward the circulation tank.

[0011] During the operation of the substrate processing device, the pump and the temperature regulator are always driven. When the discharge valve is closed, the SPM drawn from the circulation tank flows along the SPM supply piping to the branch point of the SPM circuit piping by opening the loop valve, and returns to the circulation tank from the branch point through the SPM circuit piping. In other words, when SPM is not ejected from the SPM nozzle, SPM circulates along the circulation tank, the SPM supply piping, and the SPM circuit piping. By circulating the 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 piping. Then, the SPM ejected from the SPM nozzle is supplied to the substrate.

[0012] However, in Patent Document 1, when the recovery and reuse of SPM are repeated, the concentrations of sulfuric acid and hydrogen peroxide solution contained in the SPM decrease to values ​​that are not suitable for reuse.

[0013] In particular, the hydrogen peroxide concentration decreases significantly. That is, as the temperature of the SPM increases, the SPM removal capability (the SPM's ability to remove resist) improves. Therefore, it is ideal to use the SPM at high temperatures. However, hydrogen peroxide readily decomposes into water and oxygen at high temperatures. Therefore, when SPM is repeatedly recovered and reused, there is a concern that the hydrogen peroxide concentration will drop to a level unsuitable for reuse relatively early on.

[0014] In short, in the method described in Patent Document 1, the resist cannot be efficiently removed from the substrate due to the decrease in the concentrations of sulfuric acid and hydrogen peroxide solution contained in the SPM.

[0015] 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 produced based on a recovered sulfuric acid-containing liquid.

[0016] [Technical means to solve the problem]

[0017] The present invention provides a substrate processing apparatus for removing resist from a substrate using SPM, which is a mixed liquid of sulfuric acid and hydrogen peroxide. The apparatus comprises: a substrate holding unit for holding a substrate; a nozzle having a nozzle and spraying SPM from the nozzle toward the substrate held by the substrate holding unit; a mixing section connected to the nozzle; a sulfuric acid-containing liquid supply device for recovering liquid supplied to and discharged from the substrate, producing a sulfuric acid-containing liquid based on the recovered liquid, and supplying the produced sulfuric acid-containing liquid to the mixing section; a hydrogen peroxide water supply unit for supplying hydrogen peroxide water to the mixing section; and a control device for controlling the sulfuric acid-containing liquid supply device and the hydrogen peroxide water supply unit; the control device executing: a sulfuric acid-containing liquid producing step for recovering SPM supplied to and discharged from the substrate to produce a sulfuric acid-containing liquid; and an SPM spraying step for supplying the produced sulfuric acid-containing liquid and hydrogen peroxide water to the mixing section, mixing the sulfuric acid-containing liquid and hydrogen peroxide water in the mixing section to produce SPM, and spraying the produced SPM from the nozzle.

[0018] In this specification, the sulfuric acid-containing liquid is a liquid containing sulfuric acid, which 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.

[0019] According to this configuration, a sulfuric acid-containing liquid is produced based on the SPM discharged and recovered from the substrate, rather than the SPM itself. The produced sulfuric acid-containing liquid is mixed with hydrogen peroxide water and reused as SPM.

[0020] From the perspective of improving the SPM removal capability, the sulfuric acid concentration of the prepared sulfuric acid-containing liquid is required to be within a predetermined concentration range. Furthermore, from the same perspective, the temperature of the prepared sulfuric acid-containing liquid is required to be within a predetermined temperature range.

[0021] By focusing on the sulfuric acid contained in the recovered SPM and adjusting the sulfuric acid concentration and temperature of the sulfuric acid-containing liquid so that it is separated from hydrogen peroxide, a sulfuric acid-containing liquid can be produced that satisfies both the desired concentration and temperature ranges. Furthermore, by mixing the produced sulfuric acid-containing liquid with aqueous hydrogen peroxide, the SPM produced from the recovered sulfuric acid-containing liquid can be used to efficiently remove resist from a substrate.

[0022] 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 recovered liquid and a sulfuric acid replenishing unit for replenishing sulfuric acid in the first tank. The second liquid storage unit includes a second tank for storing liquid transferred from the first tank; a first pipe connected at both ends to the second tank for circulating the liquid stored in the second tank; and a first heater for heating the liquid circulating through the second tank and the first pipe. During the sulfuric acid-containing liquid preparation step, the control device performs: a first storage step for recovering SPM discharged from the substrate and storing it in the first tank as sulfuric acid-containing liquid; a sulfuric acid replenishing step for replenishing sulfuric acid in the first tank using the sulfuric acid replenishing unit; a second storage step for storing the sulfuric acid-containing liquid transferred from the first tank in the second tank; and a first heating step for heating the sulfuric acid-containing liquid circulating through the second tank and the first pipe using the first heater. Furthermore, the control device performs a step of supplying the sulfuric acid-containing liquid circulating along the second tank and the first pipe to the mixing section in the SPM ejecting step.

[0023] According to this configuration, the SPM discharged and recovered from the substrate is stored in the first tank as a sulfuric acid-containing liquid in the first liquid storage unit. Furthermore, sulfuric acid from the sulfuric acid replenishing unit is replenished in the first tank. This allows the sulfuric acid concentration of the sulfuric acid-containing liquid stored in the first tank to be accurately adjusted to a desired concentration range.

[0024] Furthermore, in the second liquid storage section, the sulfuric acid-containing liquid transported from the first liquid storage section 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 accurately adjusted to a desired temperature range.

[0025] The second liquid storage section, which is specifically configured to adjust the temperature of the sulfuric acid-containing liquid, is separately provided from the first liquid storage section, which is configured to supplement the sulfuric acid-containing liquid with sulfuric acid (and to 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 adjusted while the sulfuric acid-containing liquid is supplemented in the liquid storage section, the temperature of the sulfuric acid-containing liquid in the liquid storage section becomes unstable. Since the second liquid storage section, which is specifically configured to adjust the temperature of the sulfuric acid-containing liquid, is separately provided from the first liquid storage section, which is configured to supplement the sulfuric acid-containing liquid with sulfuric acid, the temperature of the sulfuric acid-containing liquid in the second liquid storage section becomes stable. Thus, the sulfuric acid-containing liquid transported to the mixing section can be adjusted to a desired temperature range.

[0026] In one 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 through the second tank and the first pipe. Furthermore, the control device executes the sulfuric acid replenishing step when the measured value obtained by the sulfuric acid concentration meter is less than a predetermined judgment value.

[0027] According to this configuration, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through the second tank and the first pipe is measured by the concentration meter, and thus the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through the second tank and the first pipe can be accurately determined. As a result, the sulfuric acid concentration of the sulfuric acid-containing liquid fed to the mixing section can be accurately adjusted to a desired concentration range.

[0028] In one embodiment of the present invention, the first liquid storage unit further includes: a second pipe connected at both ends to 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 through the first tank and the second pipe. The control device further executes a second heating step during the sulfuric acid-containing liquid producing step, wherein the second heater heats the sulfuric acid-containing liquid circulating through the first tank and the second pipe.

[0029] According to this configuration, in the first liquid storage section, 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 sections, respectively. Therefore, a greater amount of heat can be applied to the sulfuric acid-containing liquid. Consequently, the sulfuric acid-containing liquid can be heated to a higher temperature in the second liquid storage section.

[0030] Furthermore, since the sulfuric acid-containing liquid is heated using both the first and second heaters, the burden on one heater (ie, the first heater) can be reduced.

[0031] In one embodiment of the present invention, the first liquid storage section further includes a second pipe connected to the first tank at both ends and circulated through which the sulfuric acid-containing liquid stored in the first tank circulates. Furthermore, the first liquid storage section is not provided with a unit for heating the sulfuric acid-containing liquid circulating through the first tank and the second pipe.

[0032] According to this configuration, the first liquid storage section is not provided with a means for heating the sulfuric acid-containing liquid circulating through the first tank and the second pipe. In other words, the sulfuric acid-containing liquid is not heated in the first liquid storage section. Therefore, the sulfuric acid-containing liquid circulating through the first tank and the second pipe has a relatively low temperature.

[0033] In one embodiment of the present invention, the first liquid storage unit further includes a filter that is interposed in the second pipe and captures foreign matter contained in the sulfuric acid-containing liquid flowing through the second pipe.

[0034] According to this configuration, the sulfuric acid-containing liquid flowing along the second pipe is captured by the filter. The temperature of the sulfuric acid-containing liquid passing through the filter is relatively low.

[0035] If the high-temperature sulfuric acid-containing liquid is circulated through the first tank and the second pipe, there is a concern that as the high-temperature sulfuric acid-containing liquid continues to circulate through the filter, the filter may expand, thereby increasing the diameter of each pore in the filter. If the diameter of each pore in the filter increases, the diameter of the foreign matter that the filter can capture increases. Therefore, there is a concern that the filtration performance of the filter may be reduced, and the foreign matter contained in the sulfuric acid-containing liquid may not be effectively captured in the first liquid storage portion.

[0036] 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 filter performance of the filter. Therefore, foreign matter contained in the sulfuric acid-containing liquid can be well captured in the first liquid storage section. Thus, clean sulfuric acid-containing liquid can be supplied to the mixing section.

[0037] In one embodiment of the present invention, the sulfuric acid-containing liquid supply device further includes a third liquid storage unit. The third liquid storage unit includes: a third tank for storing the liquid transferred from the first tank; a third pipe connected to the third tank at both ends for circulating the liquid stored in the third tank; and a second heater for heating the liquid circulating through the third tank and the third pipe. During the sulfuric acid-containing liquid preparation step, the control device further performs: a third storage step for storing the sulfuric acid-containing liquid transferred from the first tank in the third tank; and a second heating step for heating the sulfuric acid-containing liquid circulating through the third tank and the third pipe using the second heater. Furthermore, during the SPM ejection step, the control device further performs a step for transferring the sulfuric acid-containing liquid circulating through the third tank and the third pipe to the second tank.

[0038] According to this configuration, the sulfuric acid-containing liquid transported from the first liquid storage section circulates along the third tank and the third pipe. The sulfuric acid-containing liquid circulating along 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. This allows for a greater amount of heat to be applied to the sulfuric acid-containing liquid. Consequently, the sulfuric acid-containing liquid can be heated to a higher temperature in the second liquid storage section.

[0039] Furthermore, since the sulfuric acid-containing liquid is heated using both the first and second heaters, the burden on the first heater can be reduced.

[0040] In one embodiment of the present invention, the first liquid storage unit further includes a cooler for cooling the sulfuric acid-containing liquid circulating through the first tank and the second pipe. The control device further executes a cooling step during the sulfuric acid-containing liquid producing step of cooling the sulfuric acid-containing liquid circulating through the first tank and the second pipe using the cooler.

[0041] 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 lowered to room temperature or below.

[0042] In this case, it is preferred that the first liquid storage section further include the filter.

[0043] According to this configuration, since the temperature of the sulfuric acid-containing liquid passing through the filter can be lowered to room temperature or below, a decrease in filtration performance can be more effectively suppressed. Therefore, foreign matter contained in the sulfuric acid-containing liquid can be better captured in the first liquid storage section. Thus, a cleaner sulfuric acid-containing liquid can be supplied to the mixing section.

[0044] 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.

[0045] According to this configuration, the sulfuric acid-containing liquid can be cooled without causing an increase in cost.

[0046] In one embodiment of the present invention, a first heating temperature, which is a heating temperature of the first heater, is higher than a second heating temperature, which is a heating temperature of the second heater.

[0047] According to this configuration, the sulfuric acid-containing liquid, which has been heated to the second heating temperature in the first liquid storage section (the third liquid storage section), is supplied to the second liquid storage section. Furthermore, the sulfuric acid-containing liquid is heated in the second liquid storage section and heated to the first heating temperature. In other words, the sulfuric acid-containing liquid is heated in stages. Therefore, the sulfuric acid-containing liquid can be heated to a higher temperature in the second liquid storage section. Thus, even when the temperature of the sulfuric acid-containing liquid to be transported to the mixing section (the first heating temperature) is set to an extremely high temperature, such a high-temperature sulfuric acid-containing liquid can be well produced.

[0048] 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. The control device further performs a third heating step during the sulfuric acid-containing liquid preparation step, wherein the third heater heats the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid supply pipe.

[0049] According to this configuration, the sulfuric acid-containing liquid circulating through the second tank and the first pipe is guided to the sulfuric acid-containing liquid supply pipe. Furthermore, the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid supply pipe is heated by the third heater. Heating by the third heater allows the sulfuric acid-containing liquid to be further heated than when it circulates through the second tank and the first pipe.

[0050] In one embodiment of the present invention, the substrate processing device further includes: a mixing ratio changing unit for changing the ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution in the mixing section; a recovery pipe for recovering the liquid supplied to the substrate held by the substrate holding unit and discharged from the substrate and transporting it to the sulfuric acid-containing liquid supply device; a liquid discharge pipe for supplying the liquid supplied to the substrate held by the substrate holding unit and discharged from the substrate; and a switching unit for switching the pipe for supplying the liquid discharged from the substrate held by the substrate holding unit between the liquid discharge pipe and the recovery pipe. Moreover, the control device further executes: a first SPM supplying step of mixing the sulfuric acid-containing liquid and the hydrogen peroxide solution at a first mixing ratio representing the ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution by controlling the mixing ratio changing unit to produce the first SPM, and supplying the produced first SPM to the substrate held by the substrate holding unit; a second SPM supplying step of mixing the sulfuric acid-containing liquid and the hydrogen peroxide solution at a second mixing ratio representing the ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution and being greater than the first mixing ratio by controlling the mixing ratio changing unit to produce the second SPM, and supplying the produced second SPM to the substrate held by the substrate holding unit after stopping the supply of the first SPM in the first SPM supplying step; a liquid discharge step of controlling the switching unit to allow the first SPM supplied to and discharged from the substrate in the first SPM supplying step to flow into the liquid discharge piping; and a recovery step of controlling the switching unit to allow the second SPM supplied to and discharged from the substrate in the second SPM supplying step to flow into the recovery piping.

[0051] According to this configuration, when forming the first SPM, the sulfuric acid-containing liquid and the hydrogen peroxide solution are mixed at a first mixing ratio. When forming the second SPM, the sulfuric acid-containing liquid and the hydrogen peroxide solution are mixed at a second mixing ratio. The first mixing ratio and the second mixing ratio both represent the ratio of the volume of the sulfuric acid-containing liquid before mixing to the volume of the hydrogen peroxide solution before mixing. The first mixing ratio is smaller than the second mixing ratio. Therefore, the concentration of hydrogen peroxide contained in the first SPM is higher than the concentration of hydrogen peroxide contained in the second SPM.

[0052] Because the hydrogen peroxide concentration is relatively high, the first SPM has a higher removal capacity than the second SPM. Therefore, resist can be efficiently removed from the substrate. Furthermore, after the first SPM is supplied to the substrate, the second SPM is supplied to the substrate. Although the second SPM has a lower removal capacity than the first SPM, since the first SPM removes almost all of the resist from the substrate, only the relatively easy-to-remove resist remains on the substrate. Therefore, even the second SPM, with its lower removal capacity, can reliably remove resist from the substrate.

[0053] The first SPM supplied to and discharged from the substrate flows into the drain pipe rather than the recovery pipe. The first SPM discharged from the substrate has a relatively high concentration of hydrogen peroxide and a relatively low concentration of sulfuric acid. Furthermore, the first SPM discharged from the substrate contains a large amount of contaminants (such as resist carbides) generated by the reaction between the first SPM and the resist. Therefore, the first SPM discharged from the substrate is not suitable for recovery.

[0054] On the other hand, the sulfuric acid concentration in the second SPM discharged from the substrate is relatively high. Consequently, 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, which has a relatively high sulfuric acid concentration and a low contaminant content, is directed to the recovery pipe to produce a sulfuric acid-containing liquid. This produced sulfuric acid-containing liquid is mixed with hydrogen peroxide solution. The sulfuric acid contained in this sulfuric acid-containing liquid reacts with hydrogen peroxide to produce new SPM. This reduces the amount of SPM discarded.

[0055] As described above, 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 solution before mixing, is high, SPM with a high sulfuric acid concentration can be recovered due to the recovery of SPM. Furthermore, rather than maintaining a high sulfuric acid concentration, SPM with a high hydrogen peroxide concentration and sufficient removal capacity is supplied to the substrate before SPM recovery begins. This allows for efficient removal of resist from the substrate. Consequently, resist can be efficiently removed from the substrate while SPM with a high sulfuric acid concentration can be recovered.

[0056] In one embodiment of the present invention, the substrate processing apparatus further includes: a first shield connected to the liquid discharge 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 and second shields between a first state in which the first shield receives liquid discharged from the substrate and a second state in which the second shield receives liquid discharged from the substrate. Furthermore, the control device further executes: a first SPM capture step in which the shield switching unit is controlled to cause the first shield to receive the first SPM discharged from the substrate in the first SPM supply step; and a second SPM capture step in which the shield switching unit is controlled to cause the second shield to receive the second SPM discharged from the substrate in the second SPM supply step.

[0057] 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 drainage pipe connected to the first shield. The second SPM received by the second shield flows into the recovery pipe connected to the second shield.

[0058] The first SPM discharged from the substrate contains a large amount of contaminants. Consequently, contaminants may remain on the inner wall of the first shield after the first SPM is received. When the first shield receives and recovers the second SPM discharged from the substrate, contaminants adhering to the first shield may mix with 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.

[0059] The present invention provides a substrate processing method, which is performed in a substrate processing device including a nozzle and a mixing section, wherein the nozzle sprays SPM, which is a mixed liquid of sulfuric acid and hydrogen peroxide solution, from a spray port toward a substrate held by a substrate holding unit, the mixing section being connected to the spray port, and the substrate processing method includes: a sulfuric acid-containing liquid preparation step, in which SPM supplied to a substrate held by the substrate holding unit and at least partially covered with a resist and discharged from the substrate is recovered to prepare the sulfuric acid-containing liquid; and an SPM spraying step, in which the prepared sulfuric acid-containing liquid and hydrogen peroxide solution are supplied to the mixing section, thereby mixing the sulfuric acid-containing liquid and hydrogen peroxide solution in the mixing section to generate SPM, and the generated SPM is sprayed from the spray port.

[0060] According to this method, a sulfuric acid-containing liquid is produced based on the SPM discharged and recovered from the substrate, rather than the SPM itself. The produced sulfuric acid-containing liquid is mixed with hydrogen peroxide water and reused as SPM.

[0061] From the perspective of improving the SPM removal capability, the sulfuric acid concentration of the prepared sulfuric acid-containing liquid is required to be within a predetermined concentration range. Furthermore, from the same perspective, the temperature of the prepared sulfuric acid-containing liquid is required to be within a predetermined temperature range.

[0062] By focusing on the sulfuric acid contained in the recovered SPM and adjusting the sulfuric acid concentration and temperature of the sulfuric acid-containing liquid so that it is separated from hydrogen peroxide, a sulfuric acid-containing liquid can be produced that satisfies both the desired concentration and temperature ranges. Furthermore, by mixing the produced sulfuric acid-containing liquid with aqueous hydrogen peroxide, the SPM produced from the recovered sulfuric acid-containing liquid can be used to efficiently remove resist from a substrate.

[0063] In one embodiment of the present invention, the sulfuric acid-containing liquid preparation step includes the following steps: recovering SPM discharged from the substrate and storing it as sulfuric acid-containing liquid in a first tank of a first liquid storage unit; a sulfuric acid replenishment step of replenishing sulfuric acid in the first tank; storing the sulfuric acid-containing liquid transferred from the first tank in a second tank of a second liquid storage unit separate from the first tank; and a heating step of heating the sulfuric acid-containing liquid circulating through the second tank and a first pipe connected to the second tank at both ends via a first heater of the second liquid storage unit. Furthermore, the SPM discharge step includes the step of supplying the sulfuric acid-containing liquid circulating through the second tank and the first pipe to the mixing unit.

[0064] According to this method, SPM discharged and recovered from the substrate is stored in the first tank as a sulfuric acid-containing liquid in the first liquid storage unit. Furthermore, sulfuric acid from the sulfuric acid replenishing unit is replenished to the first tank. This allows the sulfuric acid concentration of the sulfuric acid-containing liquid stored in the first tank to be accurately adjusted to a desired concentration range.

[0065] Furthermore, in the second liquid storage section, the sulfuric acid-containing liquid transported from the first liquid storage section 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 accurately adjusted to a desired temperature range.

[0066] The second liquid storage section, which is specifically configured to adjust the temperature of the sulfuric acid-containing liquid, can be provided separately from the first liquid storage section, which is configured to replenish sulfuric acid (and adjust the sulfuric acid concentration of the sulfuric acid-containing liquid) to the sulfuric acid-containing liquid. Since the temperature of the replenished sulfuric acid is room temperature, if the sulfuric acid-containing liquid is adjusted while the sulfuric acid-containing liquid is replenished in the liquid storage section, the temperature of the sulfuric acid-containing liquid in the liquid storage section will be unstable. Since the second liquid storage section, which is specifically configured to adjust the temperature of the sulfuric acid-containing liquid, is provided separately from the first liquid storage section, which is configured to replenish sulfuric acid to the sulfuric acid-containing liquid, the temperature of the sulfuric acid-containing liquid in the second liquid storage section is stable. Thus, the sulfuric acid-containing liquid transported to the mixing section can be adjusted to a desired temperature range.

[0067] In one embodiment of the present invention, the substrate processing method further includes: a first SPM supplying step of mixing the sulfuric acid-containing liquid and the hydrogen peroxide solution in the mixing section at a first mixing ratio representing the ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution to produce the first SPM, and supplying the produced first SPM to the substrate held by the substrate holding unit; a second SPM supplying step of mixing the sulfuric acid-containing liquid and the hydrogen peroxide solution in the mixing section at a second mixing ratio representing the ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution and greater than the first mixing ratio to produce the second SPM, and supplying the produced second SPM to the substrate held by the substrate holding unit after stopping the supply of the first SPM in the first SPM supplying step; and a liquid draining step of discharging the first SPM supplied to and discharged from the substrate in the first SPM supplying step. SPM flows into a pipe different from the recovery pipe, namely the discharge pipe, and the recovery pipe is used to recover the liquid supplied to the substrate held by the substrate holding unit and discharged from the substrate and transport it to the sulfuric acid-containing liquid supply device; and a recovery step, so that the second SPM supplied to the substrate and discharged from the substrate in the second SPM supply step flows into the recovery pipe.

[0068] According to this method, when forming the first SPM, the sulfuric acid-containing liquid and the hydrogen peroxide solution are mixed at a first mixing ratio. When forming the second SPM, the sulfuric acid-containing liquid and the hydrogen peroxide solution are mixed at a second mixing ratio. The first mixing ratio and the second mixing ratio both represent the ratio of the volume of the sulfuric acid-containing liquid before mixing to the volume of the hydrogen peroxide solution before mixing. The first mixing ratio is smaller than the second mixing ratio. Therefore, the concentration of hydrogen peroxide contained in the first SPM is higher than the concentration of hydrogen peroxide contained in the second SPM.

[0069] Because the hydrogen peroxide concentration is relatively high, the first SPM has a higher removal capacity than the second SPM. Therefore, resist can be efficiently removed from the substrate. Furthermore, after the first SPM is supplied to the substrate, the second SPM is supplied to the substrate. Although the second SPM has a lower removal capacity than the first SPM, since the first SPM removes almost all of the resist from the substrate, only the relatively easy-to-remove resist remains on the substrate. Therefore, even the second SPM, with its lower removal capacity, can reliably remove resist from the substrate.

[0070] The first SPM supplied to and discharged from the substrate flows into the drain pipe rather than the recovery pipe. The first SPM discharged from the substrate has a relatively high concentration of hydrogen peroxide and a relatively low concentration of sulfuric acid. Furthermore, the first SPM discharged from the substrate contains a large amount of contaminants (such as resist carbides) generated by the reaction between the first SPM and the resist. Therefore, the first SPM discharged from the substrate is not suitable for recovery.

[0071] On the other hand, the sulfuric acid concentration in the second SPM discharged from the substrate is relatively high. Consequently, 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, which has a relatively high sulfuric acid concentration and a low contaminant content, is directed to the recovery pipe to produce a sulfuric acid-containing liquid. This produced sulfuric acid-containing liquid is mixed with hydrogen peroxide solution. The sulfuric acid contained in this sulfuric acid-containing liquid reacts with hydrogen peroxide to produce new SPM. This reduces the amount of SPM discarded.

[0072] As described above, 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 solution before mixing, is high, SPM with a high sulfuric acid concentration can be recovered due to the recovery of SPM. Furthermore, rather than maintaining a high sulfuric acid concentration, SPM with a high hydrogen peroxide concentration and sufficient removal capacity is supplied to the substrate before SPM recovery begins. This allows for efficient removal of resist from the substrate. Consequently, resist can be efficiently removed from the substrate while SPM with a high sulfuric acid concentration can be recovered.

[0073] In one embodiment of the present invention, the substrate processing method further includes: a first SPM capturing step, in which a first shield surrounding the substrate and connected to the drain pipe receives the first SPM discharged from the substrate in the first SPM supply step; and a second SPM capturing step, in which a second shield surrounding the substrate and connected to the recovery pipe receives the second SPM discharged from the substrate in the second SPM supply step.

[0074] 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 a drainage pipe connected to the first shield. The second SPM received by the second shield flows into a recovery pipe connected to the second shield.

[0075] The first SPM discharged from the substrate contains a large amount of contaminants. Consequently, contaminants may remain on the inner wall of the first shield after the first SPM is received. When the first shield receives and recovers the second SPM discharged from the substrate, contaminants adhering to the first shield may mix with 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.

[0076] The above and other objects, features, and effects of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 This is a schematic diagram showing the substrate processing apparatus according to the first embodiment of the present invention as viewed from above.

[0078] Figure 2 Observed from the horizontal direction Figure 1 The diagram shows the first sulfuric acid-containing liquid supply device and the device main body.

[0079] Figure 3 It will Figure 2 The structure of the third capture filter shown is enlarged and shown in a cross-sectional view.

[0080] Figure 4 Observed from the horizontal direction Figure 1 The diagram shows the second sulfuric acid-containing liquid supply device and the device main body.

[0081] Figure 5 It is used to illustrate Figure 1 A schematic cross-sectional view of a configuration example of a processing unit shown.

[0082] Figure 6 This is a block diagram for explaining the electrical structure of the substrate processing apparatus.

[0083] Figure 7 This is a flowchart for explaining an example of substrate processing performed by the substrate processing apparatus.

[0084] Figure 8 Is the SPM step ( Figure 7A timing diagram showing the change in the mixing ratio of the sulfuric acid-containing liquid and the hydrogen peroxide solution in S3) and the operation of the first and second shields.

[0085] Figure 9 This is a flowchart showing a flow when a sulfuric acid-containing liquid and hydrogen peroxide water are mixed to produce SPM and SPM recovered from a substrate is supplied to another substrate.

[0086] Figure 10 It is a graph showing the transition of the sulfuric acid concentration of the recovered sulfuric acid-containing liquid.

[0087] Figure 11 This is a view of the first sulfuric acid-containing liquid supply device according to the second embodiment of the present invention as viewed from the horizontal direction.

[0088] Figure 12 This is a view of the first sulfuric acid-containing liquid supply device according to the third embodiment of the present invention as viewed from the horizontal direction.

[0089] Figure 13 This is a diagram for explaining changes in the filtration performance of a capture filter due to thermal effects. DETAILED DESCRIPTION

[0090] Figure 1 This is a schematic diagram showing the substrate processing apparatus 1 according to the first embodiment of the present invention as viewed from above.

[0091] A substrate processing apparatus 1 is a single-wafer apparatus that processes circular substrates W, such as semiconductor wafers, one by one. The apparatus 1 includes an apparatus body 2 located within a clean room, a transfer unit 3 coupled to the apparatus body 2, a processing liquid supply device, and a control device 4 for controlling the apparatus 1.

[0092] The transfer unit 3 includes a plurality of load ports LP for respectively holding a plurality of carriers C accommodating substrates W, and a transfer robot IR for transferring the substrates W to the respective carriers C.

[0093] The apparatus main body 2 includes a transfer chamber 5 and a plurality of processing units 6 that process substrates W transferred from a plurality of load ports LP using a process fluid such as a process liquid or process gas. The plurality of processing units 6 form six towers arranged at six horizontally separated positions. Each tower includes a plurality (e.g., three) of processing units 6 stacked one above the other. The six towers are arranged three on each side of the transfer chamber 5. The processing units 6 are arranged within, that is, surrounded by, the outer wall 7 of the apparatus main body 2.

[0094] In addition to the transfer robot IR, the substrate processing apparatus 1 also 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 a transfer chamber 5. The transfer robot IR transfers substrates W between the load port LP and the first substrate transfer robot CR1. The transfer robot IR includes a hand that supports the substrate W. The first substrate transfer robot CR1 transfers substrates 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 substrates W between the transfer robot IR and the second substrate transfer robot CR2. The second substrate transfer robot CR2 transfers substrates 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 that support the substrate W.

[0095] The processing liquid supply device supplies 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 for supplying the 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, adjusts it as 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 of the clean room.

[0096] In this embodiment, the substrate processing apparatus 1 includes two first sulfuric acid-containing liquid supply devices 9. The two first sulfuric acid-containing liquid supply devices 9 are arranged in a downstairs space of a clean room called a sub-clean area (Sub-Fab). Each first sulfuric acid-containing liquid supply device 9 corresponds to three towers arranged on one side of the transfer chamber 5. Each first sulfuric acid-containing liquid supply device 9 is supplied with SPM discharged from the processing units 6 contained in the corresponding three towers. The first sulfuric acid-containing liquid supply device 9 includes a first liquid storage unit 11, which recovers the SPM discharged from the processing units 6 and stores it as sulfuric acid-containing liquid, and adjusts it to a specified state.

[0097] The second sulfuric acid-containing liquid supply device 10 is provided in a one-to-one correspondence with the first sulfuric acid-containing liquid supply device 9. That is, the substrate processing apparatus 1 includes two second sulfuric acid-containing liquid supply devices 10.

[0098] The second sulfuric acid-containing liquid supply device 10 is supplied with sulfuric acid-containing liquid 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, which stores the sulfuric acid-containing liquid supplied 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 (see Figure 2 and Figure 4 ). The SPM nozzle 13 is supplied with hydrogen peroxide solution from the hydrogen peroxide water supply unit 122 (see Figure 4 ) is supplied with hydrogen peroxide solution. The sulfuric acid-containing liquid and hydrogen peroxide solution supplied to the SPM nozzle 13 are mixed in the interior (mixing portion) of the SPM nozzle 13, thereby generating SPM. Furthermore, the SPM is discharged from the ejection port 13a (see FIG. 1 ) formed at the lower portion of the SPM nozzle 13. Figure 5 The ejection port 13a is connected to the interior of the SPM nozzle 13. In the processing unit 6, the SPM ejected from the ejection port 13a is supplied to the substrate W. As a result, the resist is removed from the substrate W.

[0099] In the sulfuric acid-containing liquid supply device 8 , sulfuric acid-containing liquid is produced (sulfuric acid-containing liquid producing step) based on SPM discharged and recovered from the substrate W. The produced sulfuric acid-containing liquid is mixed with hydrogen peroxide water and reused as SPM.

[0100] From the perspective of improving the SPM removal capability, the sulfuric acid concentration of the prepared sulfuric acid-containing liquid is required to be within a predetermined concentration range. Furthermore, from the same perspective, the temperature of the prepared sulfuric acid-containing liquid is required to be within a predetermined temperature range.

[0101] The sulfuric acid-containing liquid supply device 8 focuses on the sulfuric acid contained in the recovered SPM and adjusts the sulfuric acid concentration and temperature of the sulfuric acid-containing liquid so as to separate it from hydrogen peroxide. Therefore, the sulfuric acid-containing liquid can be prepared to satisfactorily satisfy both the required concentration range and temperature range.

[0102] Then, the prepared sulfuric acid-containing liquid is mixed with hydrogen peroxide water in the SPM nozzle 13 to generate SPM, which is then ejected from the SPM nozzle 13 and supplied to the substrate W (SPM ejection step). Thus, the resist can be efficiently removed from the substrate W using the SPM produced based on the recovered sulfuric acid-containing liquid.

[0103] Figure 2 They are shown in the horizontal direction. Figure 1 FIG. 1 is a diagram showing the first sulfuric acid-containing liquid supply device 9 and the device main body 2. Figure 3 It will Figure 2 The structure of the third capture filter 37 is shown in an enlarged cross-sectional view.

[0104] like Figure 2 As shown, the first liquid storage section 11 included in the first sulfuric acid-containing liquid supply device 9 includes a recovery tank (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.

[0105] like Figure 2 As shown, the recovery tank 21 stores the SPM recovered from a total of 9 treatment units 6 contained in the corresponding 3 towers as a sulfuric acid-containing liquid. Specifically, the recovery tank 21 is connected to the downstream end of the recovery outlet pipe 26 connected to the recovery pipe 156 described below. The SPM recovered to the treatment cup 111 of each treatment unit 6 is guided to the recovery tank 21 through the recovery pipe 156 and the recovery outlet pipe 26, and is stored in the recovery tank 21 as a sulfuric acid-containing liquid. A first capture filter 27 is installed in the middle of the recovery outlet pipe 26, and the first capture filter 27 captures and removes foreign matter in the SPM flowing along the recovery outlet pipe 26. The first capture filter 27 is a filter for capturing relatively large foreign matter contained in the SPM. The structure of the first capture filter 27 is equivalent to that of the third capture filter 37 described below. Compared with the second capture filter 30 or the third capture filter (filter) 37 described below, the first capture filter 27 has the following hole 71 (refer to Figure 3 ) has a larger diameter. Recovery and outlet piping 26 extends vertically, and the SPM flowing through recovery and outlet piping 26 is pressed against first capture filter 27 by its own weight. Thus, relatively large foreign matter is captured by first capture filter 27. The SPM, from which the relatively large foreign matter has been removed, is then stored in recovery tank 21 as a sulfuric acid-containing liquid.

[0106] The recovery tank 21 is connected to the downstream ends of three recovery outlet pipes 26 corresponding to the three towers. Figure 2 In the figure, only one tower is shown in detail, and the other two towers are simply described as "other towers" and detailed description is omitted.

[0107] like Figure 2 As shown, the upstream end of the transfer pipe 28 is connected to the downstream end of the recovery tank 21 and is connected to the first circulation tank 22. The transfer pipe 28 is provided with a first liquid delivery device 29 such as a pump for drawing the sulfuric acid-containing liquid in the recovery tank 21, and a second capture filter 30. The second capture filter 30 is used to capture and remove relatively small foreign matter contained in the sulfuric acid-containing liquid flowing along the transfer pipe 28. The structure 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 hole 71 as the third capture filter 37 (see Figure 3 ) diameter. Figure 2As shown, the first liquid-feeding device 29 and the second capture filter 30 are arranged in sequence from the recovery tank 21 side. Therefore, the suction force of the first liquid-feeding device 29 forces the sulfuric acid-containing liquid flowing through the transfer pipe 28 against the second capture filter 30. This allows foreign matter to be captured by the second capture filter 30. The sulfuric acid-containing liquid is fed from the recovery tank 21 to the first circulation tank 22 via the transfer pipe 28 and stored in the first circulation tank 22 (a first storage step).

[0108] like Figure 2 As shown, the first liquid guide pipe 31 extending toward the second sulfuric acid-containing liquid supply device 10 (second liquid storage portion 12) is connected to the first circulation tank 22. A second liquid supply device 32 such as a pump for drawing the sulfuric acid-containing liquid in the first circulation tank 22 is installed in the middle of the first liquid guide pipe 31. A third capture filter 37 and an on-off valve 38 are installed in the middle of the first liquid guide pipe 31, on the downstream side of the second liquid supply device 32. The third capture filter 37 is a filter for capturing and removing relatively small foreign matter contained in the sulfuric acid-containing liquid flowing along the first liquid guide pipe 31. The third capture filter 37 removes foreign matter that has not been completely removed by the second capture filter 30.

[0109] like Figure 3 As shown, the third capture filter 37 is, for example, cylindrical with its downstream end closed, and is, for example, a standard closed-type filter. A plurality of holes 71 are formed throughout the third capture filter 37, penetrating the third capture filter 37 in the thickness direction. 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. However, the holes 71 may also be polygonal, circular, or elliptical when viewed from this direction.

[0110] like Figure 3 As shown, the third capture filter 37 is detachably mounted in a housing 72 that holds the third capture filter 37. The housing 72 includes an inlet 73 connected to the downstream end of the pipe (first liquid conduit 31) located upstream of the third capture filter 37, and an outlet 74 connected to the upstream end of the pipe (first liquid conduit 31) located downstream of the third capture filter 37.

[0111] like Figure 3As shown, the interior of the housing 72 is divided by the third capture filter 37 into an upstream space B1 of the third capture filter 37, through which the filtered sulfuric acid-containing liquid flows, and a downstream space B2 of the third capture filter 37, through which the filtered sulfuric acid-containing liquid flows. The suction force of the second liquid supply device 32 forces the sulfuric acid-containing liquid flowing along the first liquid conduit 31 against the third capture filter 37, causing the sulfuric acid-containing liquid to flow from the upstream space B1 toward the downstream space B2 and pass through the pores 71 of the third capture filter 37. Thus, the sulfuric acid-containing liquid is filtered by the third capture filter 37. Foreign matter contained in the sulfuric acid-containing liquid in the upstream space B1 is adsorbed by the wall surface of the third capture filter 37 that defines the pores 71 and captured within the pores 71. Thus, the foreign matter is removed by the third capture filter 37.

[0112] like Figure 2 As 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-conducting pipe 31 .

[0113] like Figure 2 As shown, a return pipe 40 is branched and connected to the first liquid-conducting pipe 31 between the on-off valve 38 and the third capture filter 37. The downstream end of the return pipe 40 extends toward the first circulation tank 22. A return valve 41 is installed midway along the return pipe 40. The upstream portion of the branch point 42 of the return pipe 40 in the first liquid-conducting pipe 31 and the return pipe 40 constitute the first circulation pipe 23.

[0114] like Figure 2 As shown, the sulfuric acid replenishment unit 25 supplies new sulfuric acid (sulfuric acid that has not yet been used to process substrates W) to the first circulation tank 22. The sulfuric acid replenishment unit 25 includes a sulfuric acid replenishment pipe 44 for replenishing sulfuric acid to the first circulation tank 22, and a sulfuric acid replenishment valve 45 for opening and closing the sulfuric acid replenishment pipe 44. The replenished sulfuric acid is unused sulfuric acid (e.g., concentrated sulfuric acid) having a higher sulfuric acid concentration than the sulfuric acid-containing liquid in the first circulation tank 22. The replenished sulfuric acid is at room temperature (approximately 23°C to 25°C).

[0115] During the operation of the substrate processing apparatus 1 (including periods when processing of substrates W is stopped), the second liquid supply device 32 and the first circulation heater 24 are constantly driven. Therefore, by closing the on-off valve 38 and opening the return 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 point 42, and from this branch point 42 returns to the first circulation tank 22 through the return pipe 40. In other words, while the sulfuric acid-containing liquid is not being supplied to the second liquid storage section 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 section 12, the on-off valve 38 is opened and the return valve 41 is closed, and the sulfuric acid-containing liquid drawn from the first circulation tank 22 is supplied to the second liquid storage section through the first liquid guide pipe 31.

[0116] like Figure 2 As shown, the first circulation heater 24 is installed upstream of the second liquid feeding device 32 in the middle 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). The sulfuric acid-containing liquid is circulated along the first circulation tank 22 and the first circulation pipe 23 to adjust the sulfuric acid-containing liquid to the first temperature. During the period when the sulfuric acid-containing liquid is not supplied to the second liquid storage section 12, by pre-circulating the sulfuric acid-containing liquid, the sulfuric acid-containing liquid adjusted to the first temperature can be 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 section 12.

[0117] like Figure 2 As 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 is installed midway along the drain pipe 46 to open and close the drain pipe 46. When the sulfuric acid-containing liquid stored in the first circulation tank 22 is not further used to process substrates W, the drain valve 47 is opened to drain the sulfuric acid-containing liquid stored in the first circulation tank 22 from the first circulation tank 22 and guide it to the drain tank 50, where it is stored.

[0118] like Figure 2As shown, a lead pipe 48 extends from a drain tank 50, the downstream end of which is connected to a cooling unit (not shown). A third liquid-feeding device 49, such as a pump, is installed in the lead pipe 48. When the third liquid-feeding device 49 is activated, the sulfuric acid-containing liquid stored in the drain tank 50 is drawn into the lead pipe 48 and supplied to the cooling unit. The sulfuric acid-containing liquid cooled by the cooling unit is then directed to a waste liquid device (not shown) located outside the machine for treatment.

[0119] The first liquid storage section 11 has been described above. In the first liquid storage section 11, SPM recovered from the treatment 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 piping 23. Furthermore, sulfuric acid is replenished from the sulfuric acid replenishment unit 25 to the first circulation tank 22. Since the sulfuric acid replenishment unit 25 is provided, the first liquid storage section 11 can be understood as a liquid storage section for adjusting the sulfuric acid concentration.

[0120] Figure 4 They are shown in the horizontal direction. Figure 1 FIG. 1 is a diagram showing the second sulfuric acid-containing liquid supply device 10 and the device main body 2.

[0121] 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 .

[0122] The downstream end of the first liquid guide pipe 31 is connected to the second circulation tank 51. The sulfuric acid-containing liquid adjusted to a first temperature (e.g., approximately 120°C to 130°C) in the first liquid storage section 11 is guided to the second circulation tank 51. The guided sulfuric acid-containing liquid is then stored in the second circulation tank 51 (second storage step).

[0123] Liquid meters 65 having sensor portions are installed at a plurality of positions at different heights in the second circulation tank 51 . The liquid levels of the sulfuric acid-containing liquid stored in the second circulation tank 51 are detected by these liquid meters 65 .

[0124] A common pipe 51A is connected to the second circulation tank 51. A second circulation heater 52 is interposed in the middle of the common pipe 51A.

[0125] 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, which are used to supply 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 common pipe 51A and the sulfuric acid-containing liquid flow pipe 51B constitute the second circulation pipe 53. A fourth liquid supply device 56, such as a pump, is installed midway in the sulfuric acid-containing liquid flow pipe 51B for pumping the sulfuric acid-containing liquid from the common pipe 51A. The sulfuric acid-containing liquid pumped into the second circulation pipe 53 by the fourth liquid supply 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 pipe 51B).

[0126] exist Figure 4 In the figure, only one tower is shown in detail, and the other two towers are simply described as "other towers" and detailed description is omitted.

[0127] The second circulation heater 52 heats the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation piping 53 (common piping 51A and sulfuric acid-containing liquid circulation piping 51B) (first heating step). The heating temperature of the second circulation heater 52 is set to a specified second temperature (>first temperature, first heating temperature, for example, approximately 160°C). As the sulfuric acid-containing liquid circulates along the second circulation tank 51 and the second circulation piping 53 (common piping 51A and sulfuric acid-containing liquid circulation piping 51B), the sulfuric acid-containing liquid is adjusted from the previous first temperature to the second temperature.

[0128] The second liquid storage section 12 includes sulfuric acid-containing liquid supply pipes 57, the number of which is the same as the number of treatment units 6 included in the tower. The sulfuric acid-containing liquid supply pipes 57 are branched from the second circulation pipe 53 and are used to supply sulfuric acid-containing liquid to multiple (3) treatment units 6 included in the corresponding tower.

[0129] A heater (third heater) 54 is installed midway along each sulfuric acid-containing liquid supply pipe 57. Furthermore, a flow meter 58, a sulfuric acid-containing liquid flow rate adjustment valve (mixing ratio changing unit) 59, and a sulfuric acid-containing liquid valve 60 are installed midway along each sulfuric acid-containing liquid supply pipe 57, downstream of the heater 54, in this order from the heater 54 side.

[0130] The flow meter 58 is a flow meter that detects the flow rate of the sulfuric acid-containing liquid flowing through each sulfuric acid-containing liquid supply pipe 57 .

[0131] The sulfuric acid-containing liquid flow rate regulating valve 59 is a valve for adjusting the opening 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 regulating valve 59 may be configured to include a valve body having a valve seat disposed therein, a valve element for opening and closing the valve seat, and an actuator for moving the valve element between an open position and a closed position.

[0132] The sulfuric acid-containing liquid valve 60 is a valve for controlling the supply and stop of the sulfuric acid-containing liquid to the SPM nozzle 13 .

[0133] A return pipe 61 is connected to the sulfuric acid-containing liquid supply pipe 57, branching between the sulfuric acid-containing liquid valve 60 and the sulfuric acid-containing liquid flow rate regulating valve 59. The downstream end of the return pipe 61 is connected to the sulfuric acid-containing liquid flow pipe 51B. The pressure loss in the upstream portion of the branch point 63 in the sulfuric acid-containing liquid supply pipe 57 is greater than the pressure loss in the return pipe 61.

[0134] When the sulfuric acid-containing liquid is supplied to the SPM nozzle 13, the controller 4 opens the sulfuric acid-containing liquid valve 60. This causes the pressure loss in the return pipe 61 to be greater than the pressure loss in the downstream portion of the branch point 63 of the sulfuric acid-containing liquid supply pipe 57. Consequently, the sulfuric acid-containing liquid in the upstream portion of the branch point 63 of the sulfuric acid-containing liquid supply pipe 57 is supplied to the downstream portion of the branch point 63 of the sulfuric acid-containing liquid supply pipe 57, and is then supplied to the SPM nozzle 13 from this downstream portion.

[0135] When the supply of the sulfuric acid-containing liquid to the SPM nozzle 13 is stopped, the control device 4 closes the sulfuric acid-containing liquid valve 60. This reduces the pressure loss in the return pipe 61 to a value less than the pressure loss in the downstream portion of the branch point 63 in the sulfuric acid-containing liquid supply pipe 57. Consequently, the sulfuric acid-containing liquid that has reached the branch point 63 does not flow back along the upstream portion of the branch point 63 in the sulfuric acid-containing liquid supply pipe 57, but is instead directed to the return pipe 61. The sulfuric acid-containing liquid directed to the return pipe 61 returns to the sulfuric acid-containing liquid flow 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 pipe 51B).

[0136] The heater 54 heats the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid supply pipe 57. The heating temperature of the heater 54 is set to a predetermined third temperature (> the second temperature, for example, approximately 165°C). As the sulfuric acid-containing liquid flows through the sulfuric acid-containing liquid supply pipe 57, the sulfuric acid-containing liquid, which has been previously adjusted to the second temperature, is heated from the second temperature to the third temperature.

[0137] The fourth liquid delivery device 56 and the second circulation heater 52 are constantly driven during the operation of the substrate processing apparatus 1 (including the period when processing of the substrate W is stopped). 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 flow pipe 51B).

[0138] When sulfuric acid-containing liquid valve 60 is closed, the sulfuric acid-containing liquid flowing through second circulation pipe 53 flows from second circulation pipe 53 to sulfuric acid-containing liquid supply pipe 57, flows through branch point 63 to return pipe 61, and returns to sulfuric acid-containing liquid flow pipe 51B. Thus, the sulfuric acid-containing liquid circulates along second circulation tank 51 and second circulation pipe 53.

[0139] On the other hand, when the sulfuric acid-containing liquid valve 60 is open, the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid flow 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. In other words, the sulfuric acid-containing liquid adjusted to the third temperature is supplied to the SPM nozzle 13.

[0140] The amount of the sulfuric acid-containing liquid accumulated in the second circulation tank 51 is constantly monitored by the controller 4 by referring to the output of the liquid meter 65. Furthermore, when the amount of the sulfuric acid-containing liquid accumulated in the second circulation tank 51 falls below the lower limit, the on-off valve 38 is opened, and the sulfuric acid-containing liquid is supplied from the first liquid storage section 11 through the first liquid guide pipe 31.

[0141] A sulfuric acid concentration meter 64 is installed in one of the three sulfuric acid-containing liquid flow pipes 51B, downstream of the fourth liquid delivery device 56. This sulfuric acid concentration meter 64 measures the sulfuric acid concentration of the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid flow pipe 51B (that is, the sulfuric acid-containing liquid circulating through the second circulation tank 51 and the second circulation pipe 53). Since the sulfuric acid concentration of the sulfuric acid-containing liquid flowing through the three second circulation pipes 53 is assumed to be the same, the sulfuric acid concentration meter 64 only needs to be installed in one of the three second circulation pipes 53.

[0142] The controller 4 constantly monitors the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through 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) by referring to the output of the sulfuric acid concentration meter 64. Furthermore, when the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through the second circulation tank 51 and the second circulation pipe 53 falls below the lower limit concentration, the sulfuric acid replenishment valve 45, which opens and closes the sulfuric acid replenishment pipe 44, is opened to supply sulfuric acid to the first circulation tank 22 (sulfuric acid replenishment step). As a result, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through the first circulation tank 22 and the first circulation pipe 23 increases, and subsequently, after a short period of time, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through the second circulation tank 51 and the second circulation pipe 53 also increases.

[0143] The second liquid storage section 12 has been described above. In the second liquid storage section 12, the sulfuric acid-containing liquid transferred from the first liquid storage section 11 is stored in the second circulation tank 51. The sulfuric acid-containing liquid stored in the second circulation tank 51 is heated. This allows the temperature of the sulfuric acid-containing liquid in the second liquid storage section 12 to be raised to a temperature suitable for processing. Therefore, the second liquid storage section 12 can be understood as a liquid storage section for adjusting the temperature of the sulfuric acid-containing liquid.

[0144] Figure 5 It is a schematic cross-sectional view for explaining a configuration example of the processing unit 6 .

[0145] The processing unit 6 includes: a box-shaped chamber 107 having an internal space; a rotating chuck (substrate holding unit) 108, which holds a substrate W in a horizontal position 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 rinsing liquid supply unit 110, which is used to supply rinsing liquid to the upper surface of the substrate W held by the rotating chuck 108; and a cylindrical processing cup 111, which surrounds the rotating chuck 108.

[0146] Chamber 107 includes a box-shaped partition wall 112; an FFU (fan filter unit) 114, which serves as an air supply unit and delivers clean air from the top of partition wall 112 into partition wall 112 (corresponding to the interior of chamber 107); and an exhaust device (not shown) that exhausts the gas within chamber 107 from the bottom of partition wall 112. FFU 114 is positioned above partition wall 112 and attached to the ceiling of partition wall 112. FFU 114 delivers clean air from the ceiling of partition wall 112 into chamber 107. The exhaust device (not shown) is connected to the bottom of process cup 111 via an exhaust pipe 113 connected to process cup 111, and draws gas from the bottom of process cup 111. FFU 114 and the exhaust device (not shown) create a downflow within chamber 107.

[0147] The spin chuck 108 is a clamping chuck that horizontally clamps and holds the substrate W. Specifically, the spin chuck 108 includes a rotation motor (rotation unit) M; a rotation shaft 115 integrated with the drive shaft of the rotation motor M; and a disk-shaped spin base 116 mounted substantially horizontally on the upper end of the rotation shaft 115.

[0148] The spin base 116 includes a horizontal circular upper surface 116a having an outer diameter larger than that of the substrate W. A plurality (three or more, for example, six) of clamping members 117 are arranged on the periphery of the upper surface 116a. The plurality of clamping members 117 are arranged on the periphery of the upper surface of the spin base 116 at appropriate intervals on a circle corresponding to the outer shape of the substrate W.

[0149] The SPM nozzle 13 is, for example, a linear nozzle that ejects SPM in a continuous stream. The SPM nozzle 13 is mounted on the front end of the nozzle arm 119. The SPM nozzle 13 is mounted on the nozzle arm 119 in a vertical position, for example, ejecting the processing liquid (SPM) in a direction perpendicular to the upper surface of the substrate W. The nozzle arm 119 extends horizontally. Furthermore, a nozzle moving unit 120 is coupled to the nozzle arm 119 to move the SPM nozzle 13 by moving the nozzle arm 119. The nozzle moving unit 120 includes an electric motor.

[0150] The nozzle moving unit 120 horizontally moves the SPM nozzle 13 by horizontally moving the nozzle arm 119 about a vertical swing axis defined around the process cup 111. The nozzle moving unit 120 horizontally moves the SPM nozzle 13 between a processing position where the SPM liquid ejected from the SPM nozzle 13 impinges on the upper surface of the substrate W and a retracted position where the SPM nozzle 13 is positioned around the spin chuck 108 when viewed from above. In this embodiment, the processing position is, for example, a position where the SPM liquid ejected from the SPM nozzle 13 impinges on the center portion of the upper surface of the substrate W.

[0151] The treatment liquid supply device includes a hydrogen peroxide solution supply unit 122 that supplies hydrogen peroxide solution (H2O2) to the SPM nozzle 13. The hydrogen peroxide solution supply unit 122 includes a hydrogen peroxide solution pipe 135 connected to the SPM nozzle 13; a hydrogen peroxide solution valve 136 for opening and closing the hydrogen peroxide solution pipe 135; and a hydrogen peroxide solution flow control valve (mixing ratio changing unit) 137 that adjusts the opening of the hydrogen peroxide solution valve 136 to adjust the flow rate of the hydrogen peroxide solution flowing through the hydrogen peroxide solution valve 136. The hydrogen peroxide solution flow control valve 137 may also include a valve body with a valve seat disposed therein, 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. Unregulated hydrogen peroxide solution at approximately room temperature (20-40°C) is supplied to the hydrogen peroxide solution pipe 135 from a hydrogen peroxide solution supply source (not shown).

[0152] When the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide solution valve 136 are opened, high-temperature (165°C) sulfuric acid-containing liquid from the sulfuric acid-containing liquid supply pipe 57 and hydrogen peroxide solution from the hydrogen peroxide solution pipe 135 are supplied into the housing (not shown) of the SPM nozzle 13 and thoroughly mixed (stirred) within the housing. This mixing uniformly blends the sulfuric acid-containing liquid and hydrogen peroxide solution, and the sulfuric acid contained in the sulfuric acid-containing liquid reacts with the hydrogen peroxide solution to produce a mixed liquid of sulfuric acid and hydrogen peroxide solution (SPM). The SPM contains peroxomonosulfuric acid (H2SO5), which has a strong oxidizing power, and is heated to a temperature higher than that of the sulfuric acid-containing liquid (e.g., approximately 165°C) and hydrogen peroxide solution before mixing (e.g., approximately 190°C to approximately 220°C). The resulting high-temperature SPM is discharged from a discharge port opened at the front end (e.g., the lower end) of the housing of the SPM nozzle 13.

[0153] 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 solution supplied to the SPM nozzle 13 is changed by the hydrogen peroxide solution flow rate adjustment valve 137. Therefore, the mixing ratio of the sulfuric acid-containing liquid and the hydrogen peroxide solution is changed by the sulfuric acid-containing liquid flow rate adjustment valve 59 and the hydrogen peroxide solution flow rate adjustment valve 137. The mixing ratio of the sulfuric acid-containing liquid and the hydrogen peroxide solution (the flow rate ratio of the sulfuric acid-containing liquid and the hydrogen peroxide solution) is adjusted, for example, within a range of 30:1 (sulfuric acid-containing liquid:hydrogen peroxide solution) to 2:1 (sulfuric acid-containing liquid:hydrogen peroxide solution).

[0154] The rinsing liquid supply unit 110 includes a rinsing liquid nozzle 147 that discharges rinsing liquid toward the upper surface of the substrate W. The rinsing liquid nozzle 147 is, for example, a linear nozzle that discharges liquid in a continuous stream. The rinsing liquid nozzle 147 is a fixed nozzle fixed relative to the partition wall 112 of the chamber 107. The discharge port of the rinsing liquid nozzle 147 is directed toward the center of the upper surface of the substrate W. The rinsing liquid nozzle 147 may also be a scanning nozzle that is movable within the chamber 107. In other words, the rinsing liquid supply unit 110 may also include a nozzle moving unit that moves the rinsing liquid nozzle 147 to move the landing position of the rinsing liquid relative to the upper surface of the substrate W within the upper surface of the substrate W.

[0155] Rinse liquid nozzle 147 is connected to a rinse liquid pipe 148 that guides rinse liquid from a rinse liquid supply source. A rinse liquid valve 149 is installed midway along rinse liquid pipe 148 to switch the supply of rinse liquid from rinse liquid nozzle 147 on and off. When rinse liquid valve 149 is opened, rinse liquid is supplied from rinse liquid pipe 148 to rinse liquid nozzle 147 and ejected from an outlet at the lower end of rinse liquid nozzle 147.

[0156] When the rinse liquid valve 149 is closed, the supply of 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), but is not limited to DIW. It can be any of carbonated water, electrolytic ionized water, hydrogen water, ozone water, ammonia water, and diluted hydrochloric acid water (e.g., approximately 10 ppm to 100 ppm). The rinse liquid can be at room temperature (20 to 40°C) or heated before being supplied to the substrate W.

[0157] The processing cup 111 is arranged on the outside of the substrate W held by the rotating chuck 108 (in the direction away from the rotation axis A1). The processing cup 111 surrounds the side of the rotating base 116. When the processing liquid is supplied to the substrate W while the rotating chuck 108 rotates the substrate W, the processing liquid supplied to the substrate W is thrown around the substrate W. When the processing liquid is supplied to the substrate W, the upper end portion 111a of the processing cup 111 that is open upward is arranged above the rotating base 116. Therefore, the processing liquid such as chemical solution or water discharged around the substrate W is received by the processing cup 111. Moreover, the processing liquid received by the processing cup 111 is transported to the recovery tank 21 of the first liquid storage part 11 or is transported to the waste liquid device (not shown) via the cooling unit (not shown).

[0158] The processing cup 111 includes: multiple cylindrical shields (a first shield 143, a second shield 144, and a third shield 145) for receiving the processing liquid (chemical solution or rinse liquid) scattered around the substrate W; multiple annular cups (a first cup 141 and a second cup 142) for receiving the processing liquid guided by the multiple shields; and a cylindrical component 140 that surrounds the multiple shields and the multiple cups.

[0159] The processing cup 111 also includes a shield lifting unit 146 that independently raises and lowers each shield (first shield 143, second shield 144, and 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 motor's power to each shield. When the shield lifting unit 146 raises or lowers at least one of the three shields, the processing cup 111 switches state.

[0160] As described below, the state of the process cup 111 can be switched to a retracted state ( Figure 5 The present invention can be applied to any one of the following situations: the first opposing state in which the first shield 143 faces the peripheral end surface of the substrate W, the second opposing state in which the second shield 144 faces the peripheral end surface of the substrate W, and the third opposing state in which the third shield 145 faces the peripheral end surface of the substrate W.

[0161] A first retainer cup 141 surrounds the spin chuck 108 inside the cylindrical member 140. The first retainer cup 141 defines an annular first groove 150 into which a processing liquid used to process the substrate W flows. A drain port 151 is formed at the lowest point of the bottom of the first groove 150. 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 a drain device for processing.

[0162] The second cup 142 surrounds the first cup 141 inside the cylindrical member 140. The second cup 142 defines an annular second groove 153 into which the processing liquid used to process the substrate W flows. A drain / recovery port 154 is opened at the lowest point of the bottom of the second groove 153. 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.

[0163] 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. Conversely, 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 and drain switching unit that switches the pipe into which the liquid discharged from the substrate W flows, between the recovery pipe 156 and the second drain pipe 157.

[0164] The innermost first shield 143 surrounds the spin chuck 108 inside the cylindrical member 140. The first shield 143 includes a cylindrical lower end portion 163 surrounding the spin chuck 108; a cylindrical portion 164 extending outward (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 extending vertically upward from the upper end of the cylindrical portion 164; and an annular upper end portion 166 extending obliquely upward from the upper end of the middle portion 165 toward the inside (toward the rotation axis A1 of the substrate W).

[0165] 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 with a diameter larger than that of the substrate W held by the spin chuck 108. Figure 5 As shown, the cross-sectional shape of the upper end portion 166 of the first shield 143 is a straight line. The cross-sectional shape of the upper end portion 166 may be a shape other than a straight line, such as an arc.

[0166] The second shield 144, the second shield from the inside, surrounds the first shield 143 inside the cylindrical member 140. The second shield 144 includes a cylindrical portion 167 surrounding the first shield 143 and an annular upper end portion 168 extending obliquely upward from the upper end of the cylindrical portion 167 toward the center (toward the rotation axis A1 of the substrate W). The cylindrical portion 167 of the second shield 144 is positioned in the second groove 153 of the second cup 142.

[0167] The inner circumferential end of the upper end portion 168 of the second shield 144, when viewed from above, is circular, having a diameter larger than that of the substrate W held by the spin 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 a linear shape, such as a circular arc. The upper end portion 168 of the second shield 144 vertically overlaps with the upper end portion 166 of the first shield 143. When the first and second shields 143 and 144 are in closest proximity, the upper end portion 168 of the second shield 144 is formed so as to be close to the upper end portion 166 of the first shield 143, with a slight gap therebetween.

[0168] The third shield 145, the third shield from the inside, surrounds the second shield 144 inside the cylindrical member 140. The third shield 145 includes 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 (toward the rotation axis A1 of the substrate W). The inner circumference of the upper end portion 171, when viewed from above, is circular, with a diameter larger than that of the substrate W held by the spin 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 a linear shape, such as an arc.

[0169] The first groove 150 of the first cup 141, the inner wall 143 a of the first shield 143, and the outer periphery of the outer shell of the spin chuck 108 define a first flow space (in other words, a drainage space) SP1 for guiding a chemical solution used for processing the substrate W. The second groove 153 of the second cup 142, the outer wall 143 b of the first shield 143, and the inner wall 144 a of the second shield 144 define a second flow space (in other words, a recovery space) SP2 for guiding a chemical solution used 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.

[0170] The shield elevating unit 146 elevates each shield (the first shield 143, the second shield 144, and the third shield 145) between an upper position in which the upper end of the shield is above the substrate W and a lower position in which the upper end of the shield is below the substrate W. The shield elevating unit 146 can hold each shield at any position between the upper and lower positions. The processing liquid is supplied to the substrate W with any shield facing the peripheral end surface of the substrate W.

[0171] In the first facing state of the processing cup 111 in which the innermost first shield 143 is facing the peripheral end surface of the substrate W, the first shield 143, the second shield 144 and the third shield 145 are all arranged in the upper position (processing height position). In the second facing state of the processing cup 111 in which the second second shield 144 from the inside is facing the peripheral end surface of the substrate W, the second and third shields 144 and 145 are arranged in the upper position, and the first shield 143 is arranged in the lower position. In the third facing state of the processing cup 111 in which the outermost third shield 145 is facing the peripheral end surface of the substrate W, the third shield 145 is arranged in the upper position, and the first shield 143 and the second shield 144 are arranged in the lower position. In the retreat state in which all shields are retreated from the peripheral end surface of the substrate W (refer to Figure 5 ) below, the first shield 143, the second shield 144 and the third shield 145 are all arranged in the lower position.

[0172] As described below, when the process cup 111 is switched from the first facing state to the second facing state, the first shield 143 is positioned at a cleaning height position between the upper and lower positions while the second shield 144 and third shield 145 are in the upper positions. This state represents the transition state from the first facing state to the second facing state of the process cup 111. The process cup 111 transitions to any of a plurality of states, including the first through third facing states, a retracted state, and a transition state. The transition state is when the first shield 143 faces the peripheral end surface of the substrate W.

[0173] Figure 6 This is a block diagram for explaining the electrical configuration of the substrate processing apparatus 1 .

[0174] The control device 4 is, for example, a computer. It includes a computing unit such as a CPU (Central Processing Unit), a storage unit such as a fixed memory device or a hard disk drive, and an input / output unit for inputting and outputting information. The storage unit includes a computer-readable recording medium that stores a computer program executed by the computing unit. The recording medium includes a group of steps that causes the control device 4 to perform the resist removal process described below.

[0175] The control device 4 controls the operation of the rotary 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, and the like according to a predetermined program. Furthermore, the control device 4 controls the opening and closing of the on-off valve 38, the return valve 41, the sulfuric acid replenishment valve 45, the drain valve 47, the sulfuric acid-containing liquid valve 60, the hydrogen peroxide solution valve 136, the rinse solution valve 149, the recovery valve 158, the drain valve 159, and the like according to a predetermined program. Furthermore, the control device 4 adjusts the openings of the sulfuric acid-containing liquid flow control valve 59 and the hydrogen peroxide solution flow control valve 137 according to a predetermined program. The measured values ​​of the sulfuric acid concentration meter 64 and the liquid meter 65 are input to the control device 4.

[0176] Figure 7 This is a flowchart for explaining an example of processing of a substrate W by the substrate processing apparatus 1 .

[0177] Below, refer to Figures 1 to 7 An example of processing of the substrate W will be described. This example of processing of the substrate W is a resist removal process for removing the resist from the upper surface (main surface) of the substrate W. The resist is, for example, a photoresist formed of a carbon-containing compound.

[0178] When the substrate W is processed by the substrate processing apparatus 1, the control device 4 controls the substrate transport robots (the first substrate transport robot CR1 and the second substrate transport robot CR2 (see FIG. 1 )) holding the substrate W, at least a portion of the front surface (device formation surface) of the substrate W being covered with the resist, in a state where all nozzles are retracted from above the spin chuck 108 and all shields 143 to 145 are in the lower position. Figure 1 ))'s hand enters the interior of the chamber 107. As a result, the substrate W is delivered to the spin chuck 108 with its front side facing upward and is held on the spin chuck 108.

[0179] After the substrate W is held on the spin chuck 108, the control device 4 starts rotating the spin motor M. As a result, the substrate W starts rotating ( Figure 7 The rotation speed of the substrate W is increased to a predetermined liquid processing speed (within the range of 300 to 1500 rpm, for example, 500 rpm) and maintained at this liquid processing speed. When the rotation speed of the substrate W reaches the liquid processing speed, the controller 4 executes the SPM step S3.

[0180] Specifically, the control device 4 controls the nozzle moving unit 120 to move the SPM nozzle 13 from the retreat position to the processing position. Furthermore, the control device 4 simultaneously opens the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide solution valve 136. Consequently, the sulfuric acid-containing liquid is supplied to the SPM nozzle 13 via the sulfuric acid-containing liquid supply pipe 57, and the hydrogen peroxide solution is supplied to the SPM nozzle 13 via the hydrogen peroxide solution pipe 135. The sulfuric acid-containing liquid and the hydrogen peroxide solution mix within the SPM nozzle 13, generating high-temperature SPM (e.g., 190-220°C). This SPM is ejected from the ejection port of the SPM nozzle 13 and lands on the center portion of the upper surface of the substrate W.

[0181] 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 due to centrifugal force. Consequently, the SPM is supplied to the entire upper surface of the substrate W, forming an SPM liquid film covering the entire upper surface of the substrate W. This chemical reaction between the resist and the SPM occurs, and the SPM removes the resist from the substrate W. SPM that has moved to the periphery of the substrate W scatters from the periphery toward the sides of the substrate W.

[0182] Alternatively, the control device 4 may control the nozzle moving unit 120 in the SPM step S3 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 SPM landing position on the upper surface of the substrate W passes through the entire upper surface of the substrate W. Therefore, the entire upper surface of the substrate W is scanned by the SPM landing position. This allows the entire upper surface of the substrate W to be uniformly processed.

[0183] When a predetermined period has passed since the start of SPM spraying, the control device 4 closes the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide water valve 136, and stops spraying SPM from the SPM nozzle 13. Thus, the SPM step S3 ends. Then, the control device 4 controls the nozzle moving unit 120 (see Figure 6 ), so that the SPM nozzle 13 returns to the retracted position.

[0184] Next, a rinsing step ( Figure 7 S4). Specifically, the control device 4 opens the rinsing liquid valve 149 and causes the rinsing liquid nozzle 147 to spray the rinsing liquid toward the center of the upper surface of the substrate W. The rinsing liquid sprayed from the rinsing liquid nozzle 147 lands on the center of the upper surface of the substrate W covered by the SPM. The rinsing liquid landed on the center 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. As a result, the SPM on the substrate W is washed 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 passed since the start of the rinsing step S4, the control device 4 closes the rinsing liquid valve 149 and causes the rinsing liquid nozzle 147 to stop spraying the rinsing liquid.

[0185] Next, a drying step ( Figure 7 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 up to the SPM step S3 and the rinsing step S4, and rotates the substrate W at the drying rotation speed. As a result, a large centrifugal force is applied to the liquid on the substrate W, and the liquid adhering to the substrate W is thrown off to the surrounding 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 passed after the start of the high-speed rotation of the substrate W, the control device 4 stops the rotation motor M, and the rotation of the substrate W based on the spin chuck 108 is stopped ( Figure 7 S6).

[0186] Next, the substrate W is taken out of the chamber 107 ( Figure 7Specifically, the control device 4 controls the substrate transport robot (the first substrate transport robot CR1, the second substrate transport robot CR2 (see S7)) in a state where all the shields 143 to 145 are in the lower position. Figure 1 )) enters the chamber 107. The control device 4 then holds the substrate W on the spin chuck 108 in the hand of the substrate transport robot. The control device 4 then retracts the hand of the substrate transport robot from the chamber 107. Thus, the substrate W, after the resist has been removed from the front surface (device formation surface), is unloaded from the chamber 107.

[0187] Next, the SPM step ( Figure 7 The change in the mixing ratio of the sulfuric acid-containing liquid and the hydrogen peroxide solution in S3) and the operation of the first shield 143 and the second shield 144 will be described.

[0188] Figure 8 Is the SPM step ( Figure 7 The timing diagram of the change of the mixing ratio of the sulfuric acid-containing liquid and the hydrogen peroxide solution in S3) and the operation of the first shield 143 and the second shield 144. Figure 8 In FIG, the recovery ON (continuation) indicates that the SPM discharged from the substrate W flows into the recovery pipe 156 via the second shield 144, and the recovery OFF (stop) indicates that the flow of the SPM into the recovery pipe 156 is stopped. Figure 8 In the embodiment, the progress of draining means that the SPM discharged from the substrate W flows into the first drain pipe 152 via the first shield 143, and the suspension of draining means that the flow of the SPM into the first drain pipe 152 stops. 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 so as to execute the following operations and the like.

[0189] When Figure 8 At time T1 shown, when the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide solution valve 136 are opened, the sulfuric acid-containing liquid is supplied to the SPM nozzle 13 at a first sulfuric acid-containing liquid flow rate, and the hydrogen peroxide solution is supplied to the SPM nozzle 13 at a first H₂O₂ flow rate. Thus, the sulfuric acid-containing liquid and the hydrogen peroxide solution are mixed within the SPM nozzle 13 at a first mixing ratio (first sulfuric acid-containing liquid flow rate / first H₂O₂ flow rate). Thus, the first SPM is formed within the SPM nozzle 13 and ejected from the SPM nozzle 13 toward the upper surface of the substrate W (first SPM supply step). As a result, a first SPM liquid film is formed that covers the entire upper surface of the substrate W.

[0190] When a specified time has passed since the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide water valve 136 were opened, Figure 8At the time T2 shown, the opening of at least one of the sulfuric acid-containing liquid flow regulating valve 59 and the hydrogen peroxide solution flow regulating valve 137 is changed, so that the sulfuric acid-containing liquid and the hydrogen peroxide solution 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 This example shows how the openings of both the sulfuric acid-containing liquid flow control valve 59 and the hydrogen peroxide solution flow control valve 137 are changed. Consequently, a second SPM is formed within the SPM nozzle 13 and ejected from the SPM nozzle 13 toward the upper surface of the substrate W (a second SPM supply step). As a result, the first SPM liquid film covering the entire upper surface of the substrate W is replaced with the second SPM liquid film covering the entire upper surface of the substrate W.

[0191] exist Figure 8 In the example shown, 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 solution 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 so that the flow rate of the SPM ejected from the SPM nozzle 13 remains constant even when the mixing ratio (the ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution) is changed, or they can be set so that the flow rate of the SPM ejected from the SPM nozzle 13 increases or decreases. The mixing ratio continuously changes 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 high hydrogen peroxide concentration to a state with a high sulfuric acid-containing liquid concentration.

[0192] When the specified time has passed since the SPM mixing ratio was changed to the second mixing ratio, Figure 8 At the time T5 shown, the sulfuric acid-containing liquid valve 60 and the hydrogen peroxide solution valve 136 are closed, and the ejection of SPM from the SPM nozzle 13 is stopped.

[0193] like Figure 8 As shown, the processing cup 111 is before the SPM nozzle 13 starts to eject the first SPM (in Figure 8 Before the time T1 shown in the figure, the first shield 143, the innermost shield among the three shields 143 to 145, is set to the first facing state in which the peripheral end surface of the substrate W faces each other. 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 cup 141 (first SPM capturing step). Then, the first SPM in the first cup 141 is discharged along the first drain pipe 152 ( Figure 8 The drainage is performed as shown, drainage step).

[0194] like Figure 8 As shown, at the time point when the mixing ratio of SPM is changed to the second mixing ratio ( Figure 8 At time T2 shown in FIG. 1 , 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 cup 141. After the mixing ratio of the SPM is changed to the second mixing ratio, the shield lifting unit 146 is moved to the upper position. Figure 8 At time T3 shown, the first shield 143 is lowered to a cleaning height position between the upper position and the lower position.

[0195] The shield lifting unit 146, for example, makes the first shield 143 stand still at the cleaning height position for a predetermined time, and then Figure 8 At the time T4 shown, the first shield 143 is lowered to the lower position. Therefore, the processing cup 111 is switched to the second facing state in which the second shield 144 and the peripheral end surface of the substrate W are facing each other in a state in which the second SPM is ejected from the SPM nozzle 13 and the entire upper surface area of ​​the substrate W is covered by 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 cup 142 (second SPM capturing step). Then, the second SPM in the second cup 142 is transported to the recovery tank 21 of the first liquid storage part 11 via the common piping 155 and the recovery piping 156. Thus, the second SPM supplied to the substrate W is recovered (recovery step, Figure 8 The recycling is performed as shown).

[0196] When Figure 8 When the SPM nozzle 13 stops ejecting SPM at the time T5 shown, the shield lifting unit 146 is in the Figure 8 At time T6 shown, the first shield 143 is raised from the lower position to the upper position. As a result, the processing cup 111 is switched to the first facing state in which the first shield 143 and the peripheral end surface of the substrate W face each other, while the SPM nozzle 13 stops ejecting SPM and the entire upper surface of the substrate W is covered with the SPM liquid film. In this state, the rinsing step ( Figure 7 S4). Drying step for drying the substrate W ( Figure 7 S5) is performed with the processing cup 111 set to the third facing state in which the third shield 145 and the peripheral end surface of the substrate W face each other.

[0197] Figure 9 This is a flow chart showing a process for mixing a sulfuric acid-containing liquid and a hydrogen peroxide solution to produce SPM and supplying the SPM recovered from a substrate W to another substrate W. Figure 5 and Figure 9The 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 so as to execute the following operations and the like.

[0198] As described above, start the SPM step ( Figure 7 When S3) is Figure 9 As shown, the sulfuric acid-containing liquid and hydrogen peroxide water are mixed at a first mixing ratio to prepare a first SPM ( Figure 9 The first SPM is ejected from the SPM nozzle 13 and supplied to the substrate W ( Figure 9 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 retainer cup 141.

[0199] When a predetermined time has passed since the start of the first SPM spraying, the mixing ratio of the sulfuric acid-containing liquid and the hydrogen peroxide solution (the ratio of the flow rate of the sulfuric acid-containing liquid before mixing to the flow rate of the hydrogen peroxide solution before mixing) is increased from the first mixing ratio to the second mixing ratio ( Figure 9 Thus, the sulfuric acid-containing liquid and the hydrogen peroxide solution are mixed at the second mixing ratio to form a second SPM. Then, the second SPM is supplied to the substrate W ( Figure 9 The second SPM discharged from the substrate W is recovered as a sulfuric acid-containing liquid to the recovery tank 21 ( S14 of the first liquid storage unit 11 ) via the second shield 144 , the second holder 142 , the common pipe 155 and the recovery pipe 156 . Figure 9 S15).

[0200] The sulfuric acid-containing liquid recovered in the recovery tank 21 is transported to the second circulation tank 51 of the second liquid storage part 12 through the first circulation tank 22 of the first liquid storage part 11. Hydrogen peroxide easily decomposes into water and oxygen under high temperature conditions, and therefore, the second SPM (sulfuric acid-containing liquid) recovered in 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 in 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 piping 53 (common piping 51A and sulfuric acid-containing liquid flow piping 51B). The sulfuric acid concentration of the sulfuric acid-containing liquid circulated in this way is measured by the sulfuric acid concentration meter 64 ( Figure 9 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).

[0201] 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 the answer in S17 is YES, the controller 4 opens the sulfuric acid-containing liquid valve 60. Consequently, the sulfuric acid-containing liquid flowing through the sulfuric acid-containing liquid flow pipe 51B flows along the sulfuric acid-containing liquid supply pipe 57 and is supplied to the SPM nozzle 13. Thus, the sulfuric acid-containing liquid produced based on the second SPM discharged from the substrate W is mixed with hydrogen peroxide solution to produce new SPM. This new SPM is then supplied to the subsequent substrate W. This allows the SPM discharged from the substrate W to be reused, thereby reducing the amount of SPM waste.

[0202] 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 the answer in S17 is NO), the control device 4 opens the sulfuric acid replenishing valve 45 installed in the sulfuric acid replenishing pipe 44 to replenish sulfuric acid into the first circulation tank 22 ( Figure 9 By replenishing 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. The sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 is then transported to the second circulation tank 51 via the first liquid-conducting 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 (the common pipe 51A and the sulfuric acid-containing liquid flow pipe 51B) increases. Thus, the sulfuric acid concentration of the circulating sulfuric acid-containing liquid is maintained at a high level.

[0203] In use Figures 7 to 9 In the substrate processing example described above, a sulfuric acid-containing liquid and hydrogen peroxide solution are mixed to form a first SPM, and the resulting first SPM is supplied to the substrate W. After the supply of the first SPM is stopped, a sulfuric acid-containing liquid and hydrogen peroxide solution are mixed to form a second SPM, and the resulting second SPM is supplied to the substrate W. Thus, the first SPM and the second SPM are supplied to the substrate W, and the resist is removed from the substrate W.

[0204] When forming the first SPM, the sulfuric acid-containing liquid and the hydrogen peroxide solution are mixed at a first mixing ratio. When forming the second SPM, the sulfuric acid-containing liquid and the hydrogen peroxide solution are mixed at a second mixing ratio. The first and second mixing ratios both represent the ratio of the volume of the sulfuric acid-containing liquid before mixing to the volume of the hydrogen peroxide solution before mixing. The first mixing ratio is smaller than the second mixing ratio. Therefore, the concentration of hydrogen peroxide in the first SPM is higher than that in the second SPM.

[0205] Because the hydrogen peroxide concentration is relatively high, the first SPM has a higher removal capability than the second SPM. Therefore, resist can be efficiently removed from the substrate W. Furthermore, after the first SPM is supplied to the substrate W, the second SPM is supplied to the substrate W. Although the second SPM has a lower removal capability than the first SPM, since the first SPM removes almost all the resist from the substrate W, only the relatively easy-to-remove resist remains on the substrate W. Furthermore, since the temperature of the SPM (the second SPM) supplied to the substrate W is adjusted to a very high temperature (approximately 190°C to 220°C), its removal capability, while lower than that of the first SPM, is still high. This allows the second SPM, which has a lower removal capability, to reliably remove resist from the substrate W.

[0206] The first SPM discharged from the substrate W flows into the first drain pipe 152 rather than the recovery pipe 156. The first SPM discharged from the substrate W has a relatively high concentration of hydrogen peroxide and a relatively low concentration of sulfuric acid. Furthermore, the first SPM discharged from the substrate W contains a large amount of contaminants (such as resist carbides) generated by the reaction between the first SPM and the resist. Therefore, the first SPM discharged from the substrate W is not suitable for recovery.

[0207] On the other hand, the sulfuric acid concentration in the second SPM discharged from the substrate W is relatively high. Consequently, 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, which has a relatively high sulfuric acid concentration and a low contaminant content, is guided to the recovery pipe 156 and remixed with the hydrogen peroxide solution. The sulfuric acid contained in the second SPM reacts with the hydrogen peroxide solution to produce new SPM. This reduces the amount of SPM discarded.

[0208] As described above, 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 solution before mixing, is high, SPM with a high sulfuric acid concentration can be recovered due to the recovery of SPM. Furthermore, rather than maintaining a high sulfuric acid concentration, SPM with a high hydrogen peroxide concentration and sufficient removal capacity is supplied to the substrate W before the start of SPM recovery. This allows for efficient removal of resist from the substrate W. Consequently, resist can be efficiently removed from the substrate W while SPM with a high sulfuric acid concentration can be recovered.

[0209] 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.

[0210] The first SPM discharged from the substrate W contains a large amount of contaminants. Therefore, after the first shield 143 receives the first SPM, contaminants may remain on the inner circumferential surface of the first shield 143. When the first shield 143 receives and recovers the second SPM discharged from the substrate W, contaminants adhering to the first shield 143 may mix with the second SPM. Therefore, by having the second shield 144, which is different from the first shield 143, receive the second SPM, the amount of contaminants contained in the recovered SPM can be reduced.

[0211] In this substrate processing example, when the supply of the first SPM is stopped, the first SPM discharged from the substrate W is received by the first shield 143. Then, the first shield 143 and the second shield 144 switch from the first facing position to the second facing position, and the second SPM discharged from the substrate W is received by the second shield 144. In other words, after the discharge of the first SPM containing a high content of contaminants is completed, the first shield 143 switches from directly facing the substrate W to the second shield 144. This prevents the second shield 144 from being contaminated by the first SPM containing a high content of contaminants.

[0212] Figure 10 It is a graph showing the transition of the sulfuric acid concentration of the recovered sulfuric acid-containing liquid. Figure 10 The vertical axis in the graph represents the sulfuric acid concentration of the recovered sulfuric acid-containing liquid. Figure 10 The horizontal axis in represents the number of substrates W processed by the substrate processing apparatus 1 . Figure 10 The ratio X, ratio Y, and ratio Z in ⁻¹ all represent the ratio of the flow rate of the sulfuric acid-containing liquid when the flow rate of the hydrogen peroxide solution is set to 1. The ratio X is greater than the ratio Y, and the ratio Y is greater than the ratio Z (ratio X>ratio Y>ratio Z).

[0213] observe Figure 10It can be seen that, regardless of the sulfuric acid-containing liquid ratio at X, Y, or Z, the sulfuric acid concentration in the sulfuric acid-containing liquid decreases as the number of substrates W processed increases. The rate of sulfuric acid concentration reduction increases as the sulfuric acid-containing liquid ratio decreases. Specifically, when the sulfuric acid-containing liquid ratio is Z, the rate of sulfuric acid concentration reduction in the sulfuric acid-containing liquid is the highest, while when the sulfuric acid-containing liquid ratio is Y, the rate of sulfuric acid concentration reduction in the sulfuric acid-containing liquid is the second highest. In other words, if the sulfuric acid-containing liquid ratio is high, the sulfuric acid concentration in the sulfuric acid-containing liquid is difficult to reduce. When the sulfuric acid-containing liquid ratio is X, it was confirmed that even when processing more than 100 substrates W while recovering the SPM supplied to the substrates W, the sulfuric acid concentration in the sulfuric acid-containing liquid only decreased to approximately 90%.

[0214] As described above, in this embodiment, the SPM having a high sulfuric acid concentration in the sulfuric acid-containing liquid is recovered to the sulfuric acid-containing liquid supply device 8, and the recovered SPM is reused as the sulfuric acid-containing liquid. Figure 10 As can be seen, the smaller the ratio of the sulfuric acid-containing liquid, the greater the rate of reduction in the sulfuric acid concentration. Therefore, if the ratio of the sulfuric acid-containing liquid recovered to the sulfuric acid-containing liquid supply device 8 is large, the sulfuric acid concentration in the sulfuric acid-containing liquid is unlikely to decrease even when processing multiple substrates W. Therefore, the sulfuric acid concentration of the sulfuric acid-containing liquid recovered to the sulfuric acid-containing liquid supply device 8 can be maintained at a value suitable for reuse. This reduces 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 in the first circulation tank 22. Consequently, the consumption of sulfuric acid (i.e., the amount of sulfuric acid discarded) can be reduced.

[0215] As described above, according to this embodiment, the sulfuric acid-containing liquid supply device 8 is provided with a liquid storage section for adjusting sulfuric acid concentration (first liquid storage section 11) and a liquid storage section for adjusting temperature (second liquid storage section 12). Since the temperature of the replenished sulfuric acid is room temperature, if the temperature of the sulfuric acid-containing liquid is adjusted while replenishing sulfuric acid in the second liquid storage section 12 for temperature adjustment, the temperature of the sulfuric acid-containing liquid in the liquid storage section becomes unstable. In this embodiment, since the first liquid storage section 11 for adjusting sulfuric acid concentration and the second liquid storage section 12 for temperature adjustment are provided separately, the temperature of the sulfuric acid-containing liquid in the second liquid storage section 12 is stabilized. As a result, the sulfuric acid-containing liquid supplied to the SPM nozzle 13 can be adjusted to a desired high temperature.

[0216] 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 section 11 and the second liquid storage section 12, respectively. Therefore, more heat can be given to the sulfuric acid-containing liquid. In addition, the sulfuric acid-containing liquid whose temperature is adjusted to the first temperature (about 120°C to about 130°C) in the first liquid storage section 11 is supplied to the second liquid storage section 12. Moreover, the sulfuric acid-containing liquid is heated in the second liquid storage section 12 and is heated to the second temperature (about 160°C). In other words, the sulfuric acid-containing liquid is heated in stages. Therefore, the sulfuric acid-containing liquid can be heated to a higher temperature in the second liquid storage section 12.

[0217] Furthermore, 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. The sulfuric acid-containing liquid flowing along the sulfuric acid-containing liquid supply pipe 57 is then heated by the heater 54. The heating by the heater 54 can raise the temperature of the sulfuric acid-containing liquid to a third temperature (approximately 165° C.), which is higher than when the sulfuric acid-containing liquid circulates along the second circulation tank 51 and the second circulation pipe 53.

[0218] The second SPM removal capability, when the SPM mixing ratio is the second, is inferior to the first SPM removal capability. However, the SPM removal capability depends not only on the hydrogen peroxide concentration but also on the SPM temperature. In other words, the SPM removal capability increases as the SPM temperature increases. Furthermore, as the temperature of the sulfuric acid-containing liquid increases, the temperature of the SPM after mixing also increases. Therefore, by increasing the temperature of the sulfuric acid-containing liquid before mixing, the SPM removal capability can be maintained at a high level even at the second mixing ratio. Thus, even at the second mixing ratio, the resist can be efficiently removed from the substrate W.

[0219] In this embodiment, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through the second circulation tank 51 and the second circulation pipe 53 is measured by a sulfuric acid concentration meter 64. Therefore, the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through the second circulation tank 51 and the second circulation pipe 53 can be accurately determined. Furthermore, when the sulfuric acid concentration measured by the sulfuric acid concentration meter 64 falls below a lower limit, sulfuric acid is supplied to the first circulation tank 22 via the sulfuric acid replenishing unit 25. Thus, the sulfuric acid concentration of the sulfuric acid-containing liquid supplied to the SPM nozzle 13 can be adjusted to a desired high concentration.

[0220] In this embodiment, since the sulfuric acid-containing liquid is heated using both the first circulation heater 24 and the second circulation heater 52 , the burden on the second circulation heater 52 can be reduced compared to the case where only the second circulation heater 52 is used to heat the sulfuric acid-containing liquid.

[0221] Figure 11 This is a diagram showing the first sulfuric acid-containing liquid supply device 209 according to the second embodiment of the present invention as viewed from the horizontal direction. Figure 11 In relation to the Figures 1 to 10 The same components as shown are marked with Figure 1 The same reference symbols are used and their descriptions are omitted.

[0222] The first sulfuric acid-containing liquid supply device 209 of the second embodiment differs from the first sulfuric acid-containing liquid supply device 9 of the first embodiment in that a third liquid storage section 213 is provided in addition to the first liquid storage section. The sulfuric acid-containing liquid is supplied from the first liquid storage section to the third liquid storage section 213, and the sulfuric acid-containing liquid stored in the third liquid storage section 213 is supplied to the second liquid storage section 12.

[0223] The first liquid storage section 211 differs from the first liquid storage section 11 of the first embodiment in that the first circulation heater 24 is omitted. Furthermore, the first liquid storage section 211 does not include the drain tank 50. In other words, the first liquid storage section 211 is not provided with a means for heating the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23.

[0224] The SPM recovered in the recovery tank 21 is stored in the recovery tank 21 as a sulfuric acid-containing liquid. The SPM discharged from the substrate W is cooled as it flows along the processing cup 111, the recovery pipe 156, and the recovery outlet pipe 26 before being recovered in the recovery tank 21. Therefore, the SPM recovered in the recovery tank 21 has a much lower temperature than the SPM supplied to the substrate W (approximately 190°C to 220°C), but still has a relatively high liquid temperature of approximately 80°C to 90°C.

[0225] 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 the first liquid feeding device 29. The sulfuric acid-containing liquid then circulates along the first circulation tank 22 and the first circulation pipe 23. As the sulfuric acid-containing liquid flows along the transfer pipe 28 and the first circulation pipe 23, heat is removed from the pipe walls of the transfer pipe 28 and the first circulation pipe 23, causing the temperature of the sulfuric acid-containing liquid to drop. The sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation pipe 23 is maintained above room temperature (approximately 23°C to 25°C) but below the fourth temperature (approximately 40°C to 60°C) of the sulfuric acid-containing liquid stored in the recovery tank 21 through heat balance with the pipe walls of the first circulation pipe 23.

[0226] The third liquid storage section 213 included in the first sulfuric acid-containing liquid supply device 209 includes a third circulation tank (third tank) 222 , a third circulation pipe (third pipe) 223 , and a third circulation heater (second heater) 224 .

[0227] The downstream end of the first liquid-conducting pipe 31 is connected to the third circulation tank 222. The sulfuric acid-containing liquid at the fourth temperature (e.g., approximately 40°C to approximately 60°C) in the first liquid storage section 211 is guided to the third circulation tank 222. The guided sulfuric acid-containing liquid is then stored in the third circulation tank 222 (third storage step).

[0228] The third circulation tank 222 is connected to a second liquid-conducting pipe 231 extending toward the second sulfuric acid-containing liquid supply device 10 (second liquid storage section 12). The downstream end of the second liquid-conducting pipe 231 is connected to the second circulation tank 51 of the second liquid storage section 12. A fifth liquid-feeding device 232, such as a pump for drawing sulfuric acid-containing liquid from the third circulation tank 222, is installed in the middle of the second liquid-conducting pipe 231. A fourth capture filter 237 and an on-off valve 238 are installed in the middle of the second liquid-conducting pipe 231, 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 matter contained in the sulfuric acid-containing liquid flowing along the second liquid-conducting pipe 231. The fourth capture filter 237 removes foreign matter that has not been completely removed by the third capture filter 37.

[0229] The on-off valve 238 is a valve for controlling the flow and stop of the sulfuric acid-containing liquid in the second liquid-conducting pipe 231 .

[0230] A return pipe 240 branches off from the second liquid-conducting pipe 231 between the on-off valve 238 and the fourth capture filter 237. The downstream end of the return pipe 240 extends toward the third circulation tank 222. A return valve 241 is installed midway along the return pipe 240. The upstream portion of the branch point 242 of the return pipe 240 in the second liquid-conducting pipe 231 and the return pipe 240 form the third circulation pipe 223.

[0231] During operation of the substrate processing apparatus (including periods when processing of substrates W is suspended), the fifth liquid delivery device 232 and the third circulation heater 224 are constantly driven. Therefore, by closing the on-off valve 238 and opening the return valve 241, the sulfuric acid-containing liquid drawn from the third circulation tank 222 flows along the second liquid conduit 231 to the branch point 242, and from there returns to the third circulation tank 222 via the return conduit 240. In other words, when the sulfuric acid-containing liquid is not being delivered to the second liquid storage section 12, the sulfuric acid-containing liquid circulates along the third circulation tank 222 and the third circulation conduit 223. Furthermore, when it is time to deliver the sulfuric acid-containing liquid to the second liquid storage section 12, the on-off valve 238 is opened and the return valve 241 is closed, and the sulfuric acid-containing liquid drawn from the third circulation tank 222 is supplied to the second liquid storage section 12 via the second liquid conduit 231.

[0232] The third circulation heater 224 is installed upstream of the fifth liquid supply device 232 midway along the second liquid-conducting 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 (third heating step). The heating temperature of the third circulation heater 224 is set to a predetermined first temperature (a second heating temperature, for example, approximately 120°C to 130°C). The sulfuric acid-containing liquid is circulated along the third circulation tank 222 and the third circulation pipe 223 to adjust the sulfuric acid-containing liquid to the first temperature. By pre-circulating the sulfuric acid-containing liquid while it is not being supplied to the second liquid storage section 12, the sulfuric acid-containing liquid adjusted to the first temperature can be stored in the third circulation tank 222. Furthermore, after the on-off valve 238 is opened, the sulfuric acid-containing liquid adjusted to the first temperature can be supplied to the second liquid storage section 12.

[0233] The third liquid storage section 213 includes a drain pipe 246, a drain valve 247, a lead pipe 248, a sixth liquid supply device 249, and a drain tank 250. The drain pipe 246, the drain valve 247, the lead pipe 248, the sixth liquid supply device 249, and the drain tank 250 have the same configuration and function as the drain pipe 46, the drain valve 47, the lead pipe 48, the third liquid supply device 49, and the drain tank 50, respectively.

[0234] In the second embodiment, in addition to the first embodiment described above, the following effects are achieved.

[0235] In other words, the first liquid storage section 211 is not provided with a unit for heating the sulfuric acid-containing liquid circulating through the first circulation tank 22 and the first circulation pipe 23. In other words, the sulfuric acid-containing liquid is not heated in the first liquid storage section 211. Therefore, the sulfuric acid-containing liquid circulating through the first circulation tank 22 and the first circulation pipe 23 has a relatively low temperature (approximately 40°C to approximately 60°C). Consequently, the temperature of the sulfuric acid-containing liquid passing through the third capture filter 37 is relatively low.

[0236] 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 along the third capture filter 37, the filter may expand, thereby causing each hole 71 (see Figure 3 ) is enlarged. If each hole 71 (refer to Figure 3 ) is enlarged, the diameter of the foreign matter that can be captured by the third capture filter 37 becomes larger. Therefore, there is a concern that the filtering performance of the third capture filter 37 is reduced and the foreign matter contained in the sulfuric acid-containing liquid cannot be well captured in the first liquid storage part.

[0237] In the second embodiment, the temperature of the sulfuric acid-containing liquid passing through the third capture filter 37 is relatively low (approximately 40 to 60°C), thereby suppressing degradation of the filtration performance of the third capture filter 37. Consequently, foreign matter contained in the sulfuric acid-containing liquid can be effectively captured in the first liquid reservoir 211. Consequently, clean sulfuric acid-containing liquid can be supplied to the SPM nozzle 13.

[0238] In the second embodiment, in the third liquid storage section 213, the sulfuric acid-containing liquid transferred 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 in the third liquid storage section 213 and the second liquid storage section 12 by the third circulation heater 224 and the second circulation heater 52, respectively. Since more heat can be applied to the sulfuric acid-containing liquid, the sulfuric acid-containing liquid can be heated to a higher temperature in the second liquid storage section 12.

[0239] Furthermore, since the sulfuric acid-containing liquid is heated using both the third circulation heater 224 and the second circulation heater 52 , the burden on one heater (ie, the second circulation heater 52 ) can be reduced.

[0240] Figure 12 This is a diagram showing the first sulfuric acid-containing liquid supply device 309 according to the third embodiment of the present invention as viewed from the horizontal direction. Figure 12 In relation to the Figures 1 to 10 The same components as shown are marked with Figure 1 The same reference symbols are used and their descriptions are omitted.

[0241] The first liquid storage section 311 of the first sulfuric acid-containing liquid supply device 309 of the third embodiment differs from the first liquid storage section 11 of the first sulfuric acid-containing liquid supply device 9 of the first embodiment in that the first circulation heater 24 is eliminated. In other respects, the configuration of the first liquid storage section 311 is identical to that of the first liquid storage section 11.

[0242] As described above, the SPM recovered in the recovery tank 21 has a temperature significantly lower than that of the SPM supplied to the substrate W (approximately 190°C to 220°C). Despite this, it still has a relatively high liquid temperature of approximately 80°C to 90°C. As described above, the sulfuric acid-containing liquid circulating through the first circulation tank 22 and the first circulation pipe 23 is maintained above room temperature (approximately 23°C to 25°C) but below the temperature of the sulfuric acid-containing liquid stored in the recovery tank 21 (approximately 40°C to 60°C) by thermal equilibrium with the pipe wall of the first circulation pipe 23. Furthermore, the fourth sulfuric acid-containing liquid circulating through the first circulation tank 22 and the first circulation pipe 23 is delivered to the second liquid storage portion 12 of the second sulfuric acid-containing liquid supply device 10.

[0243] Furthermore, in the second liquid storage section 12 , the sulfuric acid-containing liquid circulating along the second circulation tank 51 and the second circulation pipe 53 is heated by the second circulation heater 52 , thereby raising the temperature of the circulating sulfuric acid-containing liquid to the second temperature.

[0244] In the third embodiment, the temperature of the sulfuric acid-containing liquid passing through the third capture filter 37 is relatively low (approximately 40 to 60°C), thereby suppressing degradation of the filtration performance of the third capture filter 37. Consequently, foreign matter contained in the sulfuric acid-containing liquid can be effectively captured in the first liquid reservoir 311. Consequently, clean sulfuric acid-containing liquid can be supplied to the SPM nozzle 13.

[0245] As mentioned above, although three embodiments of the present invention have been described, the present invention can also be implemented in other forms.

[0246] For example, in the second and third embodiments, Figure 11 and Figure 12 As shown by the middle dashed line, the first liquid storage sections 211 and 311 may further include a cooler 401 for cooling the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation piping 23. The cooler 401 is, for example, installed midway along the first liquid-conducting piping 31, upstream 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 piping 23. Depending on the cooling temperature setting of the cooler 401, the sulfuric acid-containing liquid circulating along the first circulation tank 22 and the first circulation piping 23 can be cooled to room temperature (approximately 23°C to 25°C) or a temperature lower than room temperature.

[0247] Figure 13 This is a diagram for explaining changes in the filtering performance of the capture filter (third capture filter 37) due to thermal effects. Figure 13As shown, as the temperature (circulation temperature) of the sulfuric acid-containing liquid passing through the capture filter (third capture filter 37) decreases, the filtration performance of the capture filter improves (that is, it can better capture relatively small foreign matter (microparticles)). If the number of microparticles passing when the temperature of the sulfuric acid-containing liquid passing through the capture filter is set to be lower than the temperature of the sulfuric acid-containing liquid stored in the recovery tank (temperature A) is set as the benchmark (100%), then when the temperature of the sulfuric acid-containing liquid passing through the capture filter is lowered to room temperature (temperature B), the number of microparticles passing becomes 40%, and the filtration performance becomes better. On the other hand, although not shown, when the temperature of the sulfuric acid-containing liquid is above 80°C, the number of microparticles passing increases significantly compared to the benchmark (100%), and the filtration performance deteriorates. Therefore, by providing a cooler 401, relatively small foreign matter contained in the sulfuric acid-containing liquid can be better captured in the first liquid storage section 211, 311. As a result, a cleaner sulfuric acid-containing liquid can be supplied to the SPM nozzle 13.

[0248] In addition, if Figure 4 As shown by the middle dashed line, the second liquid storage unit 12 may also include a sulfuric acid supply unit 402 for supplying new sulfuric acid (sulfuric acid that has not yet been used to process the substrate W) to the second circulation tank 51. The sulfuric acid supply unit 402 includes a sulfuric acid supply pipe 403 for replenishing sulfuric acid to the second circulation tank 51, and a sulfuric acid replenishment valve 404 for opening and closing the sulfuric acid supply pipe 403. The sulfuric acid supplied to the sulfuric acid supply pipe 403 is unused sulfuric acid (e.g., concentrated sulfuric acid).

[0249] The supply of sulfuric acid from the sulfuric acid supply unit 402 is not used for replenishing sulfuric acid, which is used to increase the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through the second circulation tank 51 and the second circulation pipe 53. It is used exclusively to store the sulfuric acid-containing liquid in the second circulation tank 51 when the substrate processing apparatus 1 is started up.

[0250] In addition, the case of adopting an in-nozzle mixing method in which the sulfuric acid-containing liquid and the hydrogen peroxide solution are mixed inside the SPM nozzle 13 has been described, but an in-pipe mixing method in which the sulfuric acid-containing liquid and the hydrogen peroxide solution are mixed in a treatment liquid piping connected to the nozzle or in a mixing piping connected to the treatment liquid piping may also be adopted.

[0251] In addition, although the description assumes that the SPM recovered from the recovery and outlet pipe 26 is temporarily recovered in the recovery tank 21 in the first liquid storage section 11, 211, 311 and then stored in the first circulation tank 22, the SPM may be directly stored in the first circulation tank 22 without passing through the recovery tank 21. In this case, the recovery tank 21 may be eliminated.

[0252] Furthermore, the sulfuric acid concentration meter 64 may be provided in all of the sulfuric acid-containing liquid flow pipes 51B corresponding to the respective towers, rather than in just one. Furthermore, the sulfuric acid concentration meter 64 may be provided in the second circulation tank 51 and / or the common pipe 51A, rather than in the sulfuric acid-containing liquid flow pipe 51B. The sulfuric acid concentration of the sulfuric acid-containing liquid produced in the sulfuric acid-containing liquid supply device 8 may be measured by measuring the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through the second circulation tank 51 and the second circulation pipe 53, instead of, or in combination with, measuring the sulfuric acid concentration of the sulfuric acid-containing liquid circulating through the first circulation tank 22 and the first circulation pipe 23.

[0253] Alternatively, a single sulfuric acid-containing liquid supply device, consisting of a first sulfuric acid-containing liquid supply device 9 and a second sulfuric acid-containing liquid supply device 10, may not supply sulfuric acid-containing liquid to the treatment units 6 included in multiple (three) towers, but may supply sulfuric acid-containing liquid to only the treatment units 6 included in a single tower. In other words, a pair of first circulation tanks 22 and second circulation tanks 51 may be provided in a one-to-one correspondence with the towers of the treatment units 6. In this case, the common piping 51A may be omitted, and both ends of the sulfuric acid-containing liquid flow piping 51B may be connected to the second circulation tank 51. In other words, the second circulation piping 53 may consist solely of the sulfuric acid-containing liquid flow piping 51B.

[0254] In this embodiment, the first liquid storage section 11, 211, 311 and / or the third liquid storage section 213 may be disposed in common within the clean room (that is, on the same floor as the second liquid storage section 12) rather than being disposed on a different floor from the second liquid storage section 12. In this case, the first liquid storage section 11, 211, 311 and / or the third liquid storage section 213 may be housed and disposed in a common frame with the second liquid storage section 12 rather than being housed and disposed in separate frames.

[0255] In addition, in each of the embodiments, the substrate processing device 1 is described as a device for processing a substrate W including a semiconductor wafer, but the substrate processing device can also be a device for processing substrates such as substrates for liquid crystal display devices, substrates for FPD (Flat Panel Display) such as organic EL (electroluminescence) display devices, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, substrates for solar cells, etc.

[0256] Furthermore, various design changes can be made within the scope of the matters described in the claims.

[0257] 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.

[0258] [Explanation of Symbols]

[0259] 1 Substrate processing device

[0260] 4 Control device

[0261] 6 processing units

[0262] 8 Sulfuric acid containing liquid supply device

[0263] 11 1st liquid storage part

[0264] 12 2nd liquid storage part

[0265] 13 SPM nozzle (nozzle)

[0266] 13a The inside of the SPM nozzle (mixing section)

[0267] 22 1st circulation tank (1st tank)

[0268] 23 1st circulation piping (2nd piping)

[0269] 24 1st circulation heater (2nd heater)

[0270] 25 Sulfuric Acid Replenishment Unit

[0271] 37 3rd capture filter (filter)

[0272] 51 2nd circulation tank (2nd tank)

[0273] 52 2nd circulation heater (1st heater)

[0274] 53 Second circulation piping (first piping)

[0275] 54 Heater (3rd heater)

[0276] 59 Sulfuric acid containing liquid flow control valve (mixing ratio changing unit)

[0277] 64 Sulfuric acid concentration meter

[0278] 108 Rotary chuck (substrate holding unit)

[0279] 122 Hydrogen peroxide water supply unit

[0280] 137 Hydrogen peroxide water flow control valve (mixing ratio changing unit)

[0281] 143 First Shield

[0282] 144 Second Shield

[0283] 146 Shield lifting unit (shield switching unit)

[0284] 156 Recovery piping

[0285] 157 2nd drain piping (drain piping)

[0286] 209 The first sulfuric acid-containing liquid supply device

[0287] 211 1st liquid storage part

[0288] 213 3rd liquid storage part

[0289] 222 3rd circulation tank (3rd tank)

[0290] 223 3rd circulation piping (3rd piping)

[0291] 224 3rd circulation heater (3rd heater)

[0292] 248 Export piping

[0293] 309 The first sulfuric acid-containing liquid supply device

[0294] 311 No. 1 Liquid Storage Department

[0295] 401 Cooler

[0296] W substrate.

Claims

1. A substrate processing apparatus for removing a resist from a substrate using SPM, which is a mixture of sulfuric acid and hydrogen peroxide solution, comprising: a substrate holding unit for holding a substrate; a nozzle having a spray port and spraying the SPM from the spray port toward the substrate held by the substrate holding unit; a mixing portion, communicating with the ejection port; a sulfuric acid-containing liquid supply device for recovering liquid supplied to and discharged from the substrate held by the substrate holding unit, producing a sulfuric acid-containing liquid based on the recovered liquid, and supplying the produced sulfuric acid-containing liquid to the mixing unit; a hydrogen peroxide solution supplying unit, configured to supply hydrogen peroxide solution to the mixing portion; a mixing ratio changing unit for changing the ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution in the mixing section; a recovery pipe for recovering the liquid supplied to the substrate held by the substrate holding unit and discharged from the substrate and transporting the recovered liquid to the sulfuric acid-containing liquid supply device; a liquid discharge pipe into which a liquid supplied to and discharged from a substrate held by the substrate holding unit flows; a switching unit for switching a pipe into which liquid discharged from a substrate held by the substrate holding unit flows between the liquid discharge pipe and the recovery pipe; and a control device for controlling the sulfuric acid-containing liquid supply device, the hydrogen peroxide solution supply unit, the mixing ratio changing unit, and the switching unit; The control device performs: a sulfuric acid-containing liquid preparing step of recovering the SPM supplied to and discharged from the substrate to prepare the sulfuric acid-containing liquid; An SPM ejecting step of supplying the prepared sulfuric acid-containing liquid and hydrogen peroxide solution to the mixing section, mixing the sulfuric acid-containing liquid and hydrogen peroxide solution in the mixing section to generate SPM, and ejecting the generated SPM from the ejection port; a first SPM supplying step of mixing the sulfuric acid-containing liquid and the hydrogen peroxide solution at a first mixing ratio indicating a ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution by controlling the mixing ratio changing unit to produce a first SPM, and supplying the produced first SPM to the substrate held by the substrate holding unit; a second SPM supplying step of mixing the sulfuric acid-containing liquid and the hydrogen peroxide solution at a second mixing ratio representing a ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution and being greater than the first mixing ratio to produce a second SPM, and supplying the produced second SPM to the substrate held by the substrate holding unit after stopping the supply of the first SPM in the first SPM supplying step; a draining step of controlling the switching unit so that the first SPM supplied to the substrate and discharged from the substrate in the first SPM supplying step flows into the draining pipe; and The recovery step controls the switching unit to allow the second SPM supplied to and discharged from the substrate in the second SPM supply step to flow into the recovery pipe.

2. The substrate processing apparatus according to claim 1, wherein the substrate processing apparatus further comprises: a first shield connected to the liquid 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, and The control device also performs: a first SPM capturing step of controlling the shield switching unit so that the first shield receives the first SPM discharged from the substrate in the first SPM supplying step; and The second SPM capturing step controls the shield switching unit so that the second shield receives the second SPM discharged from the substrate in the second SPM supplying step.

3. The substrate processing apparatus according to claim 1, wherein the sulfuric acid-containing liquid supply device comprises a first liquid storage portion and a second liquid storage portion, The first liquid storage part comprises: Tank 1, for storing recovered liquid; and a sulfuric acid replenishing unit, used to replenish sulfuric acid to the first tank; The second liquid storage part includes: A second tank for storing the liquid transferred from the first tank; a first pipe connected at both ends 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 the following steps in the sulfuric acid-containing liquid preparation step: a first storage step of recovering the SPM discharged from the substrate and storing the recovered SPM in the first tank as a sulfuric acid-containing liquid; 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; and 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 The control device performs 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 ejecting step.

4. The substrate processing apparatus according to claim 3, wherein the second liquid storage unit further comprises 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 the sulfuric acid concentration meter is less than a specified judgment value.

5. The substrate processing apparatus according to claim 3, wherein the first liquid storage portion further comprises a second pipe. The second pipe is connected to the first tank at both ends and circulates the sulfuric acid-containing liquid stored in the first tank. The first liquid storage section is not provided with a means for heating the sulfuric acid-containing liquid circulating along the first tank and the second pipe.

6. The substrate processing apparatus according to claim 5, wherein the sulfuric acid-containing liquid supply device further comprises a third liquid storage unit, The third liquid storage part comprises: A third tank for storing the liquid transferred from the first tank; a third pipe, both ends of which are connected to the third tank, for circulating the liquid stored in the third tank; and a second heater for heating the liquid circulating along the third tank and the third pipe; The control device further performs the following steps during the sulfuric acid-containing liquid preparation step: a third storage step of storing the sulfuric acid-containing liquid transferred from the first tank in the third tank; and a second heating step of heating the sulfuric acid-containing liquid circulating along the third tank and the third pipe by the second heater; and The control device further executes a step of sending the sulfuric acid-containing liquid circulating along the third tank and the third pipe to the second tank during the SPM ejection step.

7. The substrate processing apparatus according to claim 5 or 6, wherein the first liquid storage unit further comprises a cooler, The cooler is used to cool the sulfuric acid-containing liquid circulating along the first tank and the second pipe, and the control device also performs a cooling step in the sulfuric acid-containing liquid preparation step, and the cooling step cools the sulfuric acid-containing liquid circulating along the first tank and the second pipe through the cooler. 8 . The substrate processing apparatus according to claim 5 , wherein the sulfuric acid-containing liquid circulating along the first tank and the second pipe is cooled only by natural cooling. 9 . The substrate processing apparatus according to claim 6 , wherein a first heating temperature, which is a heating temperature by the first heater, is higher than a second heating temperature, which is a heating temperature by the second heater.

10. The substrate processing apparatus according to claim 3, 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 along the sulfuric acid-containing liquid supply pipe; and The control device further executes a third heating step in the sulfuric acid-containing liquid producing step, wherein the third heating step heats the sulfuric acid-containing liquid flowing along the sulfuric acid-containing liquid supply pipe using the third heater.

11. A substrate processing method, performed in a substrate processing apparatus comprising a nozzle and a mixing unit, wherein the nozzle ejects SPM, which is a mixed liquid of sulfuric acid and hydrogen peroxide solution, from a nozzle outlet toward a substrate held by a substrate holding unit, the mixing unit being in communication with the nozzle outlet, the substrate processing method comprising: a sulfuric acid-containing liquid preparing step of recovering SPM supplied to and discharged from a substrate held by the substrate holding unit and at least partially covered with a resist, to prepare a sulfuric acid-containing liquid; An SPM ejecting step of supplying the prepared sulfuric acid-containing liquid and hydrogen peroxide solution to the mixing section, thereby mixing the sulfuric acid-containing liquid and hydrogen peroxide solution in the mixing section to generate SPM, and ejecting the generated SPM from the ejection port; a first SPM supplying step of changing the ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution in the mixing section, mixing the sulfuric acid-containing liquid and the hydrogen peroxide solution at a first mixing ratio representing the ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution to produce a first SPM, and supplying the produced first SPM to the substrate held by the substrate holding unit; a second SPM supplying step of mixing the sulfuric acid-containing liquid and the hydrogen peroxide solution in the mixing section to produce a second SPM by changing the ratio of the sulfuric acid-containing liquid to the hydrogen peroxide solution to a second mixing ratio greater than the first mixing ratio, and supplying the produced second SPM to the substrate held by the substrate holding unit after stopping the supply of the first SPM in the first SPM supplying step; a draining step of causing the first SPM supplied to and discharged from the substrate in the first SPM supplying step to flow into a draining pipe that is different from a recovery pipe for recovering liquid supplied to and discharged from the substrate held by the substrate holding unit; and The recovery step causes the second SPM supplied to the substrate and discharged from the substrate in the second SPM supply step to flow into the recovery pipe.

12. The substrate processing method according to claim 11, further comprising: a first SPM capturing step of causing a first shield surrounding the substrate and connected to the liquid discharge pipe to receive the first SPM discharged from the substrate in the first SPM supplying step; and In the second SPM capturing step, a second shield surrounding the substrate and connected to the recovery pipe receives the second SPM exhausted from the substrate in the second SPM supplying step.

13. The substrate processing method according to claim 11, wherein the step of preparing the sulfuric acid-containing liquid comprises the following steps: recovering the SPM discharged from the substrate and storing it in the first tank of the first liquid storage unit as a sulfuric acid-containing liquid; a sulfuric acid replenishing step of replenishing sulfuric acid to the first tank; storing the sulfuric acid-containing liquid transported from the first tank in a second tank of a second liquid storage portion different from the first tank; and a heating step of heating the sulfuric acid-containing liquid circulating along the second tank and the first pipe connected to the second tank at both ends by the first heater of the second liquid storage part; and The SPM ejecting step includes supplying the sulfuric acid-containing liquid circulating along the second tank and the first pipe to the mixing unit.

14. The substrate processing method according to claim 13, wherein the second liquid storage unit 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 replenishing step is performed when a measured value obtained by the sulfuric acid concentration meter is smaller than a specified determination value.

15. The substrate processing method according to claim 13, wherein the first liquid storage portion includes a second pipe connected to the first tank at both ends and circulated with the sulfuric acid-containing liquid stored in the first tank, and The first liquid storage section is not provided with a means for heating the sulfuric acid-containing liquid circulating along the first tank and the second pipe.

16. The substrate processing method according to claim 15, wherein the substrate processing apparatus further comprises: a third tank for storing the liquid transferred from the first tank; a third pipe connected at both ends to the third tank for circulating the liquid stored in the third tank; and a second heater for heating the liquid circulating along the third tank and the third pipe; The sulfuric acid-containing liquid preparation step further comprises: a third storage step of storing the sulfuric acid-containing liquid transferred from the first tank in the third tank; and a second heating step of heating the sulfuric acid-containing liquid circulating along the third tank and the third pipe by the second heater; and The SPM ejecting step further includes the step of sending the sulfuric acid-containing liquid circulating along the third tank and the third pipe to the second tank.

17. The substrate processing method according to claim 15 or 16, wherein the first liquid storage unit further comprises a cooler for cooling the sulfuric acid-containing liquid circulating along the first tank and the second pipe, and The sulfuric acid-containing liquid producing step further includes a cooling step of cooling the sulfuric acid-containing liquid circulating along the first tank and the second pipe by the cooler.

18. The substrate processing method according to claim 15 or 16, wherein the sulfuric acid-containing liquid circulating along the first tank and the second pipe is cooled only by natural cooling. 19 . The substrate processing method according to claim 16 , wherein a first heating temperature, which is a heating temperature by the first heater, is higher than a second heating temperature, which is a heating temperature by the second heater.

20. The substrate processing method according to claim 13, 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 unit; and a third heater for heating the sulfuric acid-containing liquid flowing along the sulfuric acid-containing liquid supply pipe; The sulfuric acid-containing liquid preparing step further includes 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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