Substrate processing apparatus and substrate processing method

Abstract

A device for treating a substrate which comprises: a treatment part in which an aqueous solution containing hydrofluoric acid, nitric acid, and phosphoric acid is fed to the substrate; a collecting part which collects the aqueous solution from the treatment part; a regulation part in which the concentrations of the components in the aqueous solution collected by the collection part are regulated; a feeding part which feeds, to the treatment part, the aqueous solution having undergone the regulation in the regulation part; and a control unit which controls the regulation part. The regulation part has both a concentration meter for determining the concentration of hydrofluoric acid in the aqueous solution and a replenishment part in which the aqueous solution is replenished by supplying hydrofluoric acid, nitric acid, and phosphoric acid thereto. The control unit controls the replenishment so that hydrofluoric acid, nitric acid, and phosphoric acid are supplied to the aqueous solution in a desired proportion on the basis of the hydrofluoric acid concentration.

Description

[Technical Field]

[0001] This disclosure relates to a substrate processing apparatus and a substrate processing method. [Background technology]

[0002] The substrate processing method described in Patent Document 1 comprises the steps of grinding the substrate surface and removing the damaged layer formed on the substrate surface by grinding. The step of removing the damaged layer includes the step of supplying a processing liquid to the substrate surface. The processing liquid is, for example, an aqueous solution containing hydrofluoric acid and nitric acid. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-147908 [Overview of the project] [Problems that the invention aims to solve]

[0004] One aspect of this disclosure provides a technology that maintains the processing quality of substrates while suppressing the wasteful disposal of chemical solutions. [Means for solving the problem]

[0005] A substrate processing apparatus according to one aspect of the present disclosure comprises: a processing unit that supplies an aqueous solution containing hydrofluoric acid, nitric acid, and phosphoric acid to a substrate; a recovery unit that recovers the aqueous solution from the processing unit; an adjustment unit that adjusts the component concentrations of the aqueous solution recovered by the recovery unit; a supply unit that supplies the aqueous solution adjusted by the adjustment unit to the processing unit; and a control unit that controls the adjustment unit. The adjustment unit includes a concentration meter that detects the hydrofluoric acid concentration of the aqueous solution and a supply unit that replenishes hydrofluoric acid, nitric acid, and phosphoric acid to the aqueous solution. The control unit controls the replenishment of hydrofluoric acid, nitric acid, and phosphoric acid to the aqueous solution in a desired ratio based on the hydrofluoric acid concentration. The substrate processing apparatus comprises a grinding unit for grinding the substrate and a transport unit for transporting the substrate from the grinding unit to the processing unit. The processing unit supplies the aqueous solution to the substrate that has been ground by the grinding unit. [Effects of the Invention]

[0006] According to one aspect of this disclosure, it is possible to maintain the processing quality of the substrate and suppress the wasteful disposal of chemical solutions. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a plan view showing a substrate processing apparatus according to one embodiment. [Figure 2] Figure 2 is a flowchart showing a substrate processing method according to one embodiment. [Figure 3] Figure 3 is a cross-sectional view showing an example of an etching apparatus. [Figure 4] Figure 4 shows an example of an etching solution circuit. [Figure 5] Figure 5 shows an example of the change in component concentration over time when the supply unit does not replenish the drug solution. [Figure 6] Figure 6 shows an example of the change in hydrofluoric acid concentration over time when the supply unit replenishes the chemical solution. [Figure 7] Figure 7 is a flowchart showing an example of adjusting the concentration of components. [Modes for carrying out the invention]

[0008] Embodiments of this disclosure will be described below with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their descriptions may be omitted. In this specification, the X-axis, Y-axis, and Z-axis directions are perpendicular to each other. The X-axis and Y-axis directions are horizontal, and the Z-axis direction is vertical.

[0009] Referring to FIG. 1, a substrate processing apparatus 1 according to an embodiment will be described. The substrate processing apparatus 1 processes a substrate W. The substrate W includes, for example, a semiconductor wafer such as a silicon wafer. The substrate W may include a plurality of devices formed on the semiconductor wafer. The devices include, for example, electronic circuits. The substrate W may be a stacked substrate in which a plurality of semiconductor wafers are stacked. The stacked substrate is obtained by bonding a plurality of semiconductor wafers.

[0010] The substrate processing apparatus 1 includes a loading / unloading station 10, a processing station 20, and a control device 90. The loading / unloading station 10 and the processing station 20 are arranged in this order from the negative X-axis side to the positive X-axis side.

[0011] The loading / unloading station 10 includes a mounting table 11. Cassettes C1 to C2 are mounted on the mounting table 11. The cassette C1 houses the substrate W before processing. The cassette C2 houses the substrate W after processing. The number of cassettes C1 and C2 is not particularly limited. A cassette (not shown) may house the substrate W that has malfunctioned during processing.

[0012] The loading / unloading station 10 includes a first transfer area 12 and a first transfer device 13. The first transfer area 12 is adjacent to the mounting table 11 and a transition device 21 described later. The first transfer device 13 transfers the substrate W between a plurality of devices adjacent to the first transfer area 12. The first transfer device 13 has a transfer arm that holds the substrate W and a drive unit that moves or rotates the transfer arm. The transfer arm can move in the horizontal direction (both the X-axis direction and the Y-axis direction) and the vertical direction, and rotate about the vertical axis. A plurality of transfer arms may be provided.

[0013] The processing station 20 includes a transition device 21, a second transfer area 22, a second transfer device 23, a grinding device 24, a cleaning device 25, and an etching device 26. Note that the arrangement and number of the devices constituting the processing station 20 are not limited to the arrangement and number shown in FIG. 1.

[0014] The transition device 21 temporarily stores the substrate W. The transition device 21 is provided between the first transfer region 12 and the second transfer region 22, and relays the substrate W between the first transfer device 13 and the second transfer device 23.

[0015] The second transfer region 22 is adjacent to the transition device 21, the grinding device 24, the cleaning device 25, and the etching device 26. The second transfer device 23 transfers the substrate W between a plurality of devices adjacent to the second transfer region 22. The second transfer device 23 includes a transfer arm that holds the substrate W and a drive unit that moves or rotates the transfer arm. The transfer arm is capable of moving in both the horizontal directions (both the X-axis direction and the Y-axis direction) and the vertical direction, and rotating about the vertical axis. A plurality of transfer arms may be provided.

[0016] The grinding device 24 grinds the substrate W. The substrate W can be thinned. The grinding device 24 may grind one side of the substrate W or both sides of the substrate W. When grinding both sides of the substrate W, the opposite side of one side of the substrate W may be ground by a separate grinding device 24. The grinding device 24 grinds the substrate W by pressing a grinding wheel against the substrate W while rotating the grinding wheel and the substrate W, for example.

[0017] The cleaning device 25 cleans the substrate W. Grinding debris adhering to the substrate W can be removed. When the grinding device 24 grinds both sides of the substrate W, the cleaning device 25 cleans both sides of the substrate W. The opposite side of one side of the substrate W may be cleaned by a separate cleaning device 25. The cleaning device 25 scrub-cleans the substrate W with, for example, a brush or a sponge.

[0018] The etching device 26 etches the substrate W by supplying a processing liquid to the substrate W. A damaged layer generated by grinding the substrate W can be removed, and cracking of the substrate W can be suppressed. When the grinding device 24 grinds both sides of the substrate W, the etching device 26 etches both sides of the substrate W. The opposite side of one side of the substrate W may be etched by a separate etching device 26. Details of the etching device 26 will be described later.

[0019] The control device 90 is, for example, a computer and comprises an arithmetic unit 91 such as a CPU (Central Processing Unit) and a storage unit 92 such as memory. The storage unit 92 stores programs that control various processes executed in the substrate processing device 1. The control device 90 controls the operation of the substrate processing device 1 by causing the arithmetic unit 91 to execute the programs stored in the storage unit 92. A unit control unit is provided to control the operation of each unit that constitutes the substrate processing device 1, and a system control unit may be provided to comprehensively control multiple unit control units. The control device 90 may be composed of a unit control unit and a system control unit. The control device 90 is an example of a control unit.

[0020] Next, a substrate processing method according to one embodiment will be described with reference to Figure 2. The substrate processing method includes, for example, steps S101 to S103. Steps S101 to S103 are carried out under the control of the control device 90.

[0021] First, the first transport device 13 removes the substrate W from the cassette C1 and transports it to the transition device 21. Next, the second transport device 23 removes the substrate W from the transition device 21 and transports it to the grinding device 24.

[0022] Next, the grinding device 24 grinds the substrate W (step S101). This thins the substrate W. After that, the second transport device 23 removes the substrate W from the grinding device 24 and transports it to the washing device 25.

[0023] Next, the cleaning device 25 cleans the substrate W (step S102). This removes any grinding debris adhering to the substrate W. After that, the second transport device 23 removes the substrate W from the cleaning device 25 and transports it to the etching device 26.

[0024] Next, the etching apparatus 26 etches the substrate W (step S103). This removes the damaged layer caused by grinding the substrate W and suppresses cracking of the substrate W. After that, the second transport apparatus 23 removes the substrate W from the etching apparatus 26 and transports it to the transition apparatus 21.

[0025] Finally, the first transport device 13 removes the substrate W from the transition device 21 and stores it in the cassette C2.

[0026] The substrate processing method only needs to include step S103. For example, instead of grinding the substrate W (step S101), the substrate processing method may include forming a modified layer inside the substrate W with a laser beam and dividing the substrate W starting from the modified layer. In any case, the substrate W can be thinned.

[0027] Next, an example of an etching apparatus 26 will be described with reference to Figure 3. The etching apparatus 26 is an example of a processing unit. The processing unit supplies processing solution L to the substrate W. In this embodiment, the processing unit is a single-wafer type that processes substrates W one at a time, but it may also be a batch type that processes multiple substrates W simultaneously. The single-wafer type processing unit will be described below.

[0028] The etching apparatus 26 includes, for example, a processing container 31, a substrate holding unit 34, a substrate rotating unit 35, a nozzle 36, a nozzle moving unit 37, a cup 38, a drain pipe 39, and an exhaust pipe 40.

[0029] The processing container 31 houses the substrate holder 34 and the like. The side wall of the processing container 31 is provided with a gate 32 and a gate valve 33 for opening and closing the gate 32. The substrate W is transported into the processing container 31 through the gate 32 by the second transport device 23 (see Figure 1). Next, the substrate W is processed with the processing liquid L inside the processing container 31. After that, the substrate W is transported out of the processing container 31 through the gate 32 by the second transport device 23.

[0030] The substrate holding portion 34 is provided inside the processing container 31 and holds the substrate W horizontally. The substrate holding portion 34 has, for example, claw portions 34a that hold the outer periphery of the substrate W. Multiple claw portions 34a are provided at equal intervals in the circumferential direction of the substrate W. Although not shown, the substrate holding portion 34 may also use vacuum suction to hold the lower surface of the substrate W.

[0031] The substrate rotating unit 35 rotates the substrate holding unit 34, thereby rotating the substrate W together with the substrate holding unit 34. The substrate rotating unit 35 includes a motor and the like.

[0032] The nozzle 36 supplies the processing solution L to the substrate W. The nozzle 36 supplies the processing solution L to, for example, a rotating substrate W. The processing solution L includes, for example, an etching solution and a rinsing solution. The etching solution is an aqueous solution containing hydrofluoric acid (HF), nitric acid (HNO3), and phosphoric acid (H3PO4). The rinsing solution is pure water such as DIW (deionized water). The nozzle 36 supplies the etching solution and the rinsing solution to the substrate W in this order. The etching solution and the rinsing solution may be supplied by separate nozzles 36. The nozzle 36 is connected to a supply unit 70, which will be described later.

[0033] The nozzle moving unit 37 moves the nozzle 36 in the horizontal direction. The nozzle moving unit 37 also moves the nozzle 36 in the radial direction of the substrate W. The nozzle moving unit 37 includes, for example, an arm 37a that holds the nozzle 36 and a drive unit 37b that rotates the arm 37a.

[0034] The cup 38 surrounds the outer periphery of the substrate W held by the substrate holding section 34 and collects the processing liquid L that splashes from the outer periphery of the substrate W.

[0035] The drain pipe 39 and exhaust pipe 40 are located at the bottom of the cup 38. The drain pipe 39 discharges the processed liquid L accumulated inside the cup 38. The drain pipe 39 is connected to the recovery unit 50, which will be described later. The exhaust pipe 40 discharges the gas accumulated inside the cup 38.

[0036] Next, with reference to Figure 4, an example of the etching solution L1's circuit will be described. Etching solution L1 is an aqueous solution containing HF, HNO3, and H3PO4. HNO3 oxidizes the substrate W, producing an oxide, and HF etches the oxide. If the substrate W is a silicon wafer, the etching of the silicon wafer is expected to proceed according to the following chemical reaction equations (1) and (2). (1) Si + HNO3 + H2O → SiO2 + HNO2 + H2 (2) SiO2 + 6HF → H2SiF6 + 2H2O H3PO4 is a component that adjusts the viscosity of the etching solution L1.

[0037] As shown in Figure 4, the substrate processing apparatus 1 comprises a recovery unit 50, an adjustment unit 60, and a supply unit 70. The recovery unit 50 recovers the etching solution L1 from the etching apparatus 26. The adjustment unit 60 adjusts the component concentration of the etching solution L1 recovered by the recovery unit 50. The supply unit 70 supplies the etching solution L1, whose component concentration has been adjusted by the adjustment unit 60, to the etching apparatus 26. The substrate processing apparatus 1 reuses the etching solution L1. This reduces the amount of etching solution L1 that is wasted.

[0038] The recovery unit 50 has a recovery line 51. The recovery line 51 connects the etching apparatus 26 and the adjustment unit 60. For example, the recovery line 51 connects the drain pipe 39 (see Figure 3) of the etching apparatus 26 and the storage tank 61 of the adjustment unit 60. A filter 52 may be provided in the middle of the recovery line 51. The filter 52 collects foreign matter in the etching solution L1.

[0039] The adjustment unit 60 includes, for example, a storage tank 61, a circulation line 62, a pump 63, a filter 64, a flow meter 65, a concentration meter 66, and a replenishment unit 67. The storage tank 61 stores the etching solution L1. The circulation line 62 takes the etching solution L1 from the storage tank 61 and returns it to the storage tank 61. By circulating the etching solution L1, the component concentration can be made uniform.

[0040] Pump 63, filter 64, flow meter 65, and concentration meter 66 are installed in the middle of the circulation line 62. Pump 63 delivers the etching solution L1. Filter 64 collects foreign matter in the etching solution L1. Flow meter 65 detects the flow rate of the etching solution L1. Control device 90 controls pump 63 so that the value detected by flow meter 65 becomes a set value. Concentration meter 66 detects the hydrofluoric acid concentration of the etching solution L1.

[0041] A thermometer and a heater (not shown) may be provided along the circulation line 62. The thermometer detects the temperature of the etching solution L1. The heater heats the etching solution L1. The control device 90 controls the heater so that the value detected by the thermometer becomes a set value.

[0042] The replenishment unit 67 supplies HF, HNO3, and H3PO4 to the etching solution L1. For example, the replenishment unit 67 supplies HF, HNO3, and H3PO4 to the storage tank 61 or the circulation line 62 (storage tank 61 in Figure 4). The replenishment unit 67 may supply HF, HNO3, or H3PO4 in the form of an aqueous solution. The replenishment unit 67 may supply HF, HNO3, and H3PO4 sequentially or simultaneously.

[0043] The supply unit 67 may have separate lines for each type of chemical solution. For example, an HF supply amount adjustment unit 67b-1 may be provided in the middle of the HF individual line 67a-1. The HF supply amount adjustment unit 67b-1 may have, for example, an on-off valve, a metering tank, and another on-off valve in that order from upstream to downstream. The metering tank measures the supply amount for one application. The HF supply amount adjustment unit 67b-1 may also have a tank, a flow meter, a flow controller, and an on-off valve. In this case, the control device 90 may control the supply amount using a meter in the tank, or it may control the supply amount using a flow meter (time integral value of the flow rate). Alternatively, the HF supply amount adjustment unit 67b-1 may have a flow meter, a flow controller, and an on-off valve without a tank. In this case, the control device 90 may control the supply amount using a flow meter (time integral value of the flow rate). The order of the flow meter, flow controller, and on-off valve is not particularly limited.

[0044] A supply adjustment unit 67b-2 for HNO3 is provided in the middle of the individual line 67a-2 for HNO3. The supply adjustment unit 67b-2 for HNO3 is configured in the same way as the supply adjustment unit 67b-1 for HF. In addition, a supply adjustment unit 67b-3 for H3PO4 is provided in the middle of the individual line 67a-3 for H3PO4. The supply adjustment unit 67b-3 for H3PO4 is configured in the same way as the supply adjustment unit 67b-1 for HF.

[0045] The waste disposal unit 68 disposes of the etching solution L1 stored in the storage tank 61. The etching solution L1 is disposed of periodically, for example, as appropriate depending on the elapsed time since the etching solution L1 was replaced or the number of substrates W processed. The waste disposal unit 68 has a discharge line 68a connected to the storage tank 61 and an on / off valve 68b that opens and closes the flow path of the discharge line 68a.

[0046] The supply unit 70 includes, for example, a supply line 71, a flow meter 72, a flow controller 73, and an on / off valve 74. The supply line 71 connects the adjustment unit 60 and the etching apparatus 26. For example, the supply line 71 connects the circulation line 62 of the adjustment unit 60 to the nozzle 36 (see Figure 3) of the etching apparatus 26.

[0047] The flow meter 72, flow controller 73, and on / off valve 74 are installed in the middle of the supply line 71. The flow meter 72 detects the flow rate of the etching solution L1. The flow controller 73 controls the flow rate of the etching solution L1. The control device 90 controls the flow controller 73 so that the value detected by the flow meter 72 becomes a set value. On / off valve 74 This opens and closes the flow path of the supply line 71.

[0048] As described above, the etching solution L1 is reused. Therefore, if the supply unit 67 does not replenish the various chemicals, the concentrations of each component will change over time, as shown in Figure 5. Specifically, the concentrations of HF, HNO3, and H3PO4 will decrease, while the concentrations of H2O and H2SiF6 will increase. This is clear from the chemical reaction equations (1) and (2) above. The decrease in H3PO4 concentration is due to the generation of H2O by etching the substrate W. The generation of H2O relatively decreases the concentration of H3PO4.

[0049] The supply unit 67 replenishes the chemical solution, thereby suppressing changes in component concentrations and preventing a decrease in the processing quality of the substrate W. To maintain the processing quality of the substrate W, it is important to suppress changes in the concentrations of HF, HNO3, and H3PO4, among other components.

[0050] However, controlling the concentrations of all three components takes time. For example, if HF is replenished to bring the HF concentration to a set value, and then HNO3 is replenished to bring the HNO3 concentration to a set value, the HF concentration will deviate from the set value. To converge all three component concentrations to the set values, it is necessary to repeat the process of replenishing HF based on the detected HF concentration, HNO3 based on the detected HNO3 concentration, and H3PO4 based on the detected H3PO4 concentration multiple times. As a result, if the liquid level of the etching solution L1 in the storage tank 61 exceeds the upper limit, the etching solution L1 stored in the storage tank 61 will have to be discarded.

[0051] To reduce the wasteful disposal of chemical solutions, it is conceivable to replenish predetermined amounts of HF, HNO3, and H3PO4 based on the number of substrates W being processed. However, in this case, since the concentrations of HF, HNO3, and H3PO4 are not monitored, abnormal concentration levels due to disturbances or other factors cannot be detected. Therefore, there is a risk that the processing quality of substrates W may deteriorate.

[0052] Therefore, in this embodiment, only the HF concentration, which is the most important of the three component concentrations for silicon etching, is controlled. The etching rate of the substrate W mainly depends on the HF concentration. In this embodiment, HF, HNO3, and H3PO4 are supplied in a desired ratio based on the HF concentration. The supply of HF, HNO3, and H3PO4 in a desired ratio is performed based on the HF concentration. The ratio of the amount of HF supplied, the amount of HNO3 supplied, and the amount of H3PO4 supplied is predetermined, for example, based on the above chemical reaction equations (1) and (2) and the target values ​​of each component concentration, and is stored in advance in the storage unit 92 of the control device 90. The ratio may be a volume ratio, a mass ratio, or a molar ratio. The ratio may be fixed.

[0053] The control device 90 controls the supply of HF, HNO3, and H3PO4 to the etching solution L1 in the desired ratio based on the HF concentration detected by the concentration meter 66. This maintains the HF concentration at the set value and preserves the processing quality of the substrate W. Furthermore, by leaving the HNO3 and H3PO4 concentrations uncontrolled, that is, by not supplying HNO3 based on the HNO3 concentration and H3PO4 based on the H3PO4 concentration, the adjustment of component concentrations can be completed in a short time, and the wasteful disposal of chemical solutions can be suppressed. The above ratios are determined so that the HNO3 and H3PO4 concentrations are maintained as close as possible to their respective target values.

[0054] The control device 90, for example as shown in Figure 6, when the hydrofluoric acid concentration N is a threshold N Th If the levels fall below a certain threshold, a first control is performed to replenish the etching solution L1 with predetermined amounts of HF, HNO3, and H3PO4. The amounts of HF, HNO3, and H3PO4 to be replenished are predetermined to be in the desired ratio, and are also determined taking into consideration the volume of the storage tank 61. The amounts of HF, HNO3, and H3PO4 to be replenished may be fixed. The amount of HNO3 to be replenished is determined according to the amount of HF to be replenished, not the HNO3 concentration. The amount of H3PO4 to be replenished is determined according to the amount of HF to be replenished, not the H3PO4 concentration.

[0055] After performing the first control, the control device 90 checks if the hydrofluoric acid concentration N reaches the threshold N. Th If the level remains below the threshold N, the first control procedure is repeated. Typically, one first control procedure is sufficient to set the hydrofluoric acid concentration N to the threshold N. Th While recovery is possible above, if recovery is not possible due to disturbances, the first control is performed again to set the hydrofluoric acid concentration N to the threshold N. Th It can recover to this extent.

[0056] Furthermore, the control device 90 sets the threshold N to when the hydrofluoric acid concentration N is reached. Th A second control may be performed, in which HF, HNO3, and H3PO4 are continuously supplied to the etching solution L1 at a desired flow rate ratio while the hydrofluoric acid concentration N is below the threshold N. Th Once the system recovers to the above level, the second control will be stopped.

[0057] Next, referring to FIG. 7, an example of adjusting the component concentration (first control) will be described. The processes after step S201 shown in FIG. 7 are carried out under the control of the control device 90. The processes after step S201 are carried out periodically.

[0058] First, the concentration meter 66 detects the hydrofluoric acid concentration N of the etching solution L1 (step S201). Next, the control device 90 determines whether the hydrofluoric acid concentration N is lower than the threshold value N Th (step S202). If the hydrofluoric acid concentration N is greater than or equal to the threshold value N Th (step S202, NO), there is no need to adjust the component concentration, so the control device 90 ends the current process.

[0059] On the other hand, if the hydrofluoric acid concentration N is lower than the threshold value N Th (step S202, YES), since the etching rate of the substrate W is low, the replenishment unit 67 replenishes the etching solution L1 with a predetermined amount of HF, HNO3, and H3PO4 respectively (step S203). After that, after a predetermined time has elapsed, the processes after step S201 are carried out again.

[0060] Even if step S203 is carried out a set number of times and the hydrofluoric acid concentration N remains lower than the threshold value N Th the control device 90 may interrupt the processing of the substrate W and perform control to give an alarm. The alarm is given using an alarm device. The alarm device is, for example, a display device, a warning light, or a buzzer, etc.

[0061] As described above, embodiments of the substrate processing apparatus and the substrate processing method according to the present disclosure have been described, but the present disclosure is not limited to the above embodiments. Within the scope described in the claims, various changes, modifications, substitutions, additions, deletions, and combinations are possible. Naturally, they also belong to the technical scope of the present disclosure.

[0062] This application claims priority based on Japanese Patent Application No. 2022-101701, filed with the Japan Patent Office on June 24, 2022, and the entire contents of Japanese Patent Application No. 2022-101701 are incorporated herein by reference. [Explanation of symbols]

[0063] 1. Substrate processing apparatus 26 Etching apparatus (processing unit) 50 Recovery Section 60 Adjustment part 66 Densitometer 67 Supply Department 70 Supply section 90 Control device (control unit) W board

Claims

1. A processing unit that supplies an aqueous solution containing hydrofluoric acid, nitric acid, and phosphoric acid to a substrate, A recovery unit for recovering the aqueous solution from the processing unit, An adjustment unit for adjusting the component concentration of the aqueous solution recovered in the recovery unit, A supply unit that supplies the aqueous solution adjusted by the adjustment unit to the processing unit, A control unit that controls the adjustment unit, Equipped with, The adjustment unit includes a concentration meter for detecting the hydrofluoric acid concentration of the aqueous solution, and a supply unit for supplying hydrofluoric acid, nitric acid, and phosphoric acid to the aqueous solution. The control unit performs a control to supply hydrofluoric acid, nitric acid, and phosphoric acid to the aqueous solution in a desired ratio based on the hydrofluoric acid concentration. The system comprises a grinding unit for grinding the substrate and a transport unit for transporting the substrate from the grinding unit to the processing unit, The processing unit is a substrate processing apparatus that supplies the aqueous solution to the substrate that has been ground in the grinding unit.

2. The substrate processing apparatus according to claim 1, wherein the control unit performs a first control, which involves supplying predetermined amounts of hydrofluoric acid, nitric acid, and phosphoric acid to the aqueous solution when the hydrofluoric acid concentration falls below a threshold.

3. The substrate processing apparatus according to claim 2, wherein the control unit performs the first control again if the hydrofluoric acid concentration remains below the threshold after the first control has been performed.

4. The substrate processing apparatus according to claim 1, wherein the control unit performs a second control, which continues to supply hydrofluoric acid, nitric acid, and phosphoric acid to the aqueous solution in a desired flow rate ratio while the hydrofluoric acid concentration is below a threshold.

5. The adjustment unit includes a storage tank for storing the aqueous solution recovered in the recovery unit, and a circulation line for taking the aqueous solution out of the storage tank and returning it to the storage tank. The substrate processing apparatus according to any one of claims 1 to 4, wherein the supply unit supplies hydrofluoric acid, nitric acid, and phosphoric acid to the storage tank or the circulation line in a desired ratio.

6. In the processing unit, an aqueous solution containing hydrofluoric acid, nitric acid, and phosphoric acid is supplied to the substrate, To recover the aqueous solution from the aforementioned processing unit, Adjusting the component concentration of the aqueous solution recovered from the aforementioned processing unit, The aqueous solution with the component concentration adjusted is supplied to the processing unit, It has, Adjusting the concentration of the aforementioned components includes detecting the hydrofluoric acid concentration in the aqueous solution and supplying hydrofluoric acid, nitric acid, and phosphoric acid to the aqueous solution in a desired ratio based on the hydrofluoric acid concentration. A substrate processing method comprising grinding the substrate and supplying the aqueous solution to the ground substrate.

7. The substrate processing method according to claim 6, wherein adjusting the component concentrations includes supplying predetermined amounts of hydrofluoric acid, nitric acid, and phosphoric acid to the aqueous solution when the hydrofluoric acid concentration falls below a threshold.

8. The substrate processing method according to claim 7, wherein adjusting the component concentrations includes, if the hydrofluoric acid concentration remains below the threshold after supplying the aqueous solution with hydrofluoric acid, nitric acid, and phosphoric acid in predetermined amounts, supplying the aqueous solution with hydrofluoric acid, nitric acid, and phosphoric acid again in predetermined amounts.

9. The substrate processing method according to claim 6, wherein adjusting the component concentrations includes continuously supplying hydrofluoric acid, nitric acid, and phosphoric acid to the aqueous solution in a desired flow rate ratio while the hydrofluoric acid concentration is below a threshold.

10. The substrate processing method according to any one of claims 6 to 9, wherein adjusting the concentration of the components includes accumulating the aqueous solution recovered from the processing unit in a storage tank, taking the aqueous solution from the storage tank into a circulation line and returning it from the circulation line to the storage tank, and supplying the storage tank or the circulation line with hydrofluoric acid, nitric acid, and phosphoric acid in a desired ratio.

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