Substrate processing method and substrate processing apparatus

Abstract

A substrate processing method and a substrate processing apparatus are provided. A substrate processing method of one embodiment of the present application includes a first cleaning step and a second cleaning step. The first cleaning step cleans a substrate with a first cleaning liquid. The second cleaning step, which is performed after the first cleaning step, cleans the substrate with a second cleaning liquid that is less clean than the first cleaning liquid. The present application can sufficiently remove particles from a substrate even when a less clean cleaning liquid is used.

Description

Technical Field

[0001] This invention relates to a substrate processing method and a substrate processing apparatus. Background Technology

[0002] It has been known for a long time that a cleaning solution is used to clean the substrate of a semiconductor wafer (hereinafter also referred to as a wafer) (see Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2007-258462 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] This invention provides a technique that can effectively remove particles from a substrate even when using a cleaning solution with low cleanliness.

[0008] Technical solutions for solving technical problems

[0009] One aspect of the substrate processing method of the present invention includes a first cleaning step and a second cleaning step. The first cleaning step involves cleaning the substrate with a first cleaning solution. The second cleaning step, following the first cleaning step, involves cleaning the substrate with a second cleaning solution that has a lower cleanliness level compared to the first cleaning solution.

[0010] Invention Effects

[0011] According to the present invention, even when using a cleaning solution with low cleanliness, particles can be thoroughly removed from the substrate. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating the general configuration of a substrate processing system according to an implementation method.

[0013] Figure 2 This is a schematic diagram illustrating an example of the configuration of a processing unit in an implementation method.

[0014] Figure 3 This is a schematic diagram showing the piping configuration of the substrate processing system in an embodiment.

[0015] Figure 4 This is a diagram illustrating the substrate processing steps of an implementation method.

[0016] Figure 5 This is a graph showing the difference caused by the timing of the supply of recycled liquid and fresh liquid in the substrate processing of the embodiment.

[0017] Figure 6This is a diagram illustrating the difference between DIW and functional water in the rinsing process of the embodiment.

[0018] Figure 7 This is a graph showing the temperature difference of the recovered liquid during the filtration process in the embodiment.

[0019] Figure 8 This is a diagram illustrating the substrate processing steps of a variation of the embodiment 1.

[0020] Figure 9 This is a diagram illustrating the substrate processing steps of Modified Example 2 of the implementation method.

[0021] Figure 10 This is a diagram illustrating the substrate processing steps of Modified Example 3 of the implementation method.

[0022] Figure 11 This is a schematic diagram showing the piping configuration of the substrate processing system in Modified Example 4 of the implementation method.

[0023] Figure 12 This is a diagram illustrating the substrate processing steps of Modified Example 4 of the implementation method.

[0024] Figure 13 This is a schematic diagram showing the piping configuration of the substrate processing system in Modified Example 5 of the implementation method.

[0025] Figure 14 This is a diagram illustrating the substrate processing steps of Modified Example 5 of the implementation method.

[0026] Figure 15 This is a schematic diagram showing the piping configuration of the substrate processing system in Modified Example 6 of the implementation method.

[0027] Figure 16 This is a diagram illustrating the substrate processing steps of Modified Example 6 of the embodiment.

[0028] Figure 17 This is a flowchart illustrating the steps of substrate processing performed by the substrate processing system in the implementation method.

[0029] Explanation of reference numerals in the attached figures

[0030] W-shaped wafer (an example of a substrate)

[0031] 1. Substrate processing system (an example of a substrate processing device)

[0032] 5 First Cleaning Fluid Supply Department

[0033] 6. Cleaning fluid recovery unit

[0034] 7 Second Cleaning Fluid Supply Department

[0035] 16. Processing Unit (An Example of a Substrate Processing Section)

[0036] 18 Control Department

[0037] 125 filter. Detailed Implementation

[0038] The substrate processing method and substrate processing apparatus disclosed in this invention will now be described in detail with reference to the accompanying drawings. Furthermore, this invention is not limited to the embodiments shown below. Additionally, the drawings are schematic, and it should be noted that the dimensional relationships and proportions of the elements may differ from reality. Furthermore, the drawings may sometimes include portions with different dimensional relationships or proportions.

[0039] Techniques for cleaning substrates such as semiconductor wafers (hereinafter referred to as wafers) using cleaning solutions are known. In this cleaning process, from the viewpoint of cost, etc., the used cleaning solution is sometimes recycled and reused for cleaning.

[0040] On the other hand, the recovered cleaning solution is less clean than the new cleaning solution, making it difficult to fully remove particles from the substrate during the cleaning process.

[0041] Therefore, people desire a technology that can effectively remove particles from the substrate using a cleaning solution with low cleanliness.

[0042] <Overview of Substrate Processing System>

[0043] First, refer to Figure 1 The general configuration of the substrate processing system 1 in the embodiment will be described. Figure 1 This is a diagram showing a schematic configuration of the substrate processing system 1 according to the embodiment. Furthermore, the substrate processing system 1 is an example of a substrate processing apparatus. Hereinafter, to clarify the positional relationships, the X-axis, Y-axis, and Z-axis, which are orthogonal to each other, are defined, with the positive direction of the Z-axis set as the vertically upward direction.

[0044] like Figure 1 As shown, the substrate processing system 1 includes an infeed / outfeed station 2 and a processing station 3. The infeed / outfeed station 2 and the processing station 3 are arranged adjacent to each other.

[0045] The infeed / outfeed station 2 includes a carrier placement section 11 and a transport section 12. Multiple carriers C are placed in the carrier placement section 11, and these multiple carriers C hold multiple substrates (in this embodiment, semiconductor wafers W (hereinafter referred to as wafers W)) in a horizontal position.

[0046] The transport section 12 is disposed adjacent to the carrier placement section 11, and has a substrate transport device 13 and a junction section 14 inside. The substrate transport device 13 has a wafer holding mechanism for holding the wafer W. In addition, the substrate transport device 13 can move in the horizontal and vertical directions and rotate about the vertical axis, and uses the wafer holding mechanism to transport the wafer W between the carrier C and the junction section 14.

[0047] Processing station 3 is disposed adjacent to conveying unit 12. Processing station 3 includes conveying unit 15 and multiple processing units 16. Processing unit 16 is an example of substrate processing unit. Multiple processing units 16 are arranged side by side on both sides of conveying unit 15.

[0048] The transport unit 15 has a substrate transport device 17 inside. The substrate transport device 17 has a wafer holding mechanism for holding the wafer W. In addition, the substrate transport device 17 can move in the horizontal and vertical directions and rotate about the vertical axis, and uses the wafer holding mechanism to transport the wafer W between the transfer unit 14 and the processing unit 16.

[0049] The processing unit 16 performs prescribed substrate processing on the wafer W transported by the substrate transport device 17. Details of the processing unit 16 will be described later.

[0050] Additionally, the substrate processing system 1 includes a control device 4. The control device 4 is, for example, a computer, including a control unit 18 and a storage unit 19. The storage unit 19 stores programs that control various processes performed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the storage unit 19.

[0051] Furthermore, the aforementioned program can also be stored on a computer-readable storage medium from which the program is installed into the storage unit 19 of the control device 4. Examples of computer-readable storage media include hard disks (HD), floppy disks (FD), optical disks (CD), magneto-optical disks (MO), and memory cards.

[0052] Additionally, the substrate processing system 1 includes a first cleaning fluid supply unit 5, a cleaning fluid recovery unit 6, and a second cleaning fluid supply unit 7. The first cleaning fluid supply unit 5 supplies the first cleaning fluid to the processing unit 16 during the cleaning process of the wafer W.

[0053] The cleaning solution recovery unit 6 recovers the cleaning solution used in the cleaning process of wafer W. The second cleaning solution supply unit 7 supplies a second cleaning solution to the processing unit 16 during the cleaning process of wafer W. This second cleaning solution has a lower cleanliness level than the first cleaning solution. Details of the first cleaning solution supply unit 5, the cleaning solution recovery unit 6, and the second cleaning solution supply unit 7 will be described later.

[0054] In the substrate processing system 1 configured as described above, firstly, the substrate transport device 13 of the delivery station 2 takes out the wafer W from the carrier C placed in the carrier placement section 11 and places the taken-out wafer W into the transfer section 14. The wafer W placed in the transfer section 14 is taken out from the transfer section 14 by the substrate transport device 17 of the processing station 3 and sent into the processing unit 16.

[0055] After being processed by the processing unit 16, the wafer W fed into the processing unit 16 is sent out of the processing unit 16 by the substrate transport device 17 and placed in the transfer section 14. Then, the processed wafer W placed in the transfer section 14 is sent back to the carrier C of the carrier placement section 11 by the substrate transport device 13.

[0056] <Structure of the Processing Unit>

[0057] Below, refer to Figure 2 The configuration of the processing unit 16 will be explained. Figure 2 This is a schematic diagram illustrating a specific configuration example of the processing unit 16. For example... Figure 2 As shown, the processing unit 16 includes a chamber 20, a liquid processing section 30, an upper surface supply section 40, a recovery cup 50, and a lower surface supply section 60.

[0058] The chamber 20 contains at least a portion of the liquid treatment section 30, the upper surface supply section 40, the recovery cup 50, and the lower surface supply section 60. An FFU (Fan Filter Unit) 21 is provided at the top of the chamber 20. The FFU 21 forms a downward flow within the chamber 20.

[0059] The liquid treatment unit 30 includes a holding part 31, a support part 32, and a driving part 33, and performs liquid treatment on the placed wafer W. The holding part 31 holds the wafer W horizontally. The support part 32 is a component extending in the vertical direction, with its root end rotatably supported by the driving part 33, and its front end supporting the holding part 31 horizontally. The driving part 33 rotates the support part 32 about the vertical axis.

[0060] The liquid treatment unit 30 uses the drive unit 33 to rotate the support unit 32, thereby rotating the holding unit 31 supported on the support unit 32, and thus rotating the wafer W held by the holding unit 31.

[0061] On the upper surface of the holding portion 31 of the liquid processing unit 30, a holding member 31a is provided to hold the wafer W from the side. The wafer W is held horizontally by the holding member 31a at a slight distance from the upper surface of the holding portion 31. Furthermore, the wafer W is held by the holding portion 31 with the surface to be processed facing upward.

[0062] The upper surface supply unit 40 supplies processing fluid to the upper surface (hereinafter also referred to as the front side) of the wafer W. The upper surface supply unit 40 includes nozzles 41a and 41b disposed on the front side of the wafer W, an arm 42 that horizontally supports the nozzles 41a and 41b, and a rotary lifting mechanism 43 that rotates and lifts the arm 42.

[0063] Nozzle 41a is connected to cleaning fluid supply path 112. Cleaning fluid supplied via cleaning fluid supply path 112 is released from nozzle 41a onto the front side of wafer W. The piping configuration of the substrate processing system 1, including the cleaning fluid supply path 112, will be described later.

[0064] Nozzle 41b is connected to functional water supply path 44. Functional water supplied via functional water supply path 44 is released from nozzle 41b onto the front side of wafer W. This functional water is an alkaline rinsing solution, such as ammonia, electrolyzed ionized water, hydrogen water, or ozone water.

[0065] The functional water supply path 44 includes, from the upstream side, a functional water supply source 44a, a valve 44b, a pressure regulating valve 44c, a flow meter 44d, and a valve 44e. The functional water supply source 44a is, for example, a tank for storing functional water.

[0066] The pressure regulating valve 44c adjusts the flow rate of the functional water supplied to the functional water supply path 44 based on the flow rate of the functional water measured by the flow meter 44d. That is, the pressure regulating valve 44c implements feedback control based on the flow rate of the functional water measured by the flow meter 44d.

[0067] Additionally, the functional water supply path 44 branches between the flow meter 44d and the valve 44e, and this branch path connects to the nozzle 61b of the lower surface supply section 60 via the valve 44f (see reference). Figure 4 )connect.

[0068] The recovery cup 50 is configured to surround the holding portion 31, collecting the processing liquid that splashes off the wafer W due to the rotation of the holding portion 31. A drain port 51 is formed at the bottom of the recovery cup 50, through which the processing liquid collected by the recovery cup 50 is discharged to the outside of the processing unit 16. Additionally, an exhaust port 52 is formed at the bottom of the recovery cup 50, through which gas supplied from the FFU 21 is discharged to the outside of the processing unit 16.

[0069] The lower surface supply section 60 passes through the hollow portion 32a of the holding section 31 and the support section 32 to supply processing fluid to the lower surface (hereinafter also referred to as the back side) of the wafer W. The lower surface supply section 60 includes nozzles 61a and 61b disposed on the back side of the wafer W (see reference 1). Figure 4 ); the arm 62 that horizontally supports the nozzles 61a and 61b (refer to Figure 4 ); and the moving mechanism 63 that moves the arm 62.

[0070] Nozzle 61a is connected to branch flow path 153. A second cleaning fluid supplied via branch flow path 153 is released from nozzle 61a onto the back side of wafer W. Details of branch flow path 153 are described later.

[0071] Nozzle 61b is connected to functional water supply path 44. Functional water supplied through functional water supply path 44 is released from nozzle 61b to the back side of chip W.

[0072] <Piping configuration of the substrate processing system>

[0073] Next, refer to Figure 3 The piping configuration of substrate processing system 1 will be described. Figure 3 This is a schematic diagram showing the piping configuration of the substrate processing system 1 according to the embodiment.

[0074] like Figure 3 As shown, the substrate processing system 1 of the embodiment includes a first cleaning fluid supply unit 5, a processing unit 16, a cleaning fluid recovery unit 6, and a second cleaning fluid supply unit 7.

[0075] The first cleaning fluid supply unit 5 supplies the first cleaning fluid to the processing unit 16. In this embodiment, the first cleaning fluid is a new, unused cleaning fluid. Therefore, in the following description, the first cleaning fluid will also be referred to as "new fluid".

[0076] Furthermore, the cleaning solution used in the cleaning process of the embodiment is an acidic cleaning solution such as DSP (a mixture of pure water, sulfuric acid, hydrofluoric acid, and hydrogen peroxide aqueous solution), BHF (buffered hydrofluoric acid), or DHF (dilute hydrofluoric acid). Moreover, the cleaning process of the embodiment is performed, for example, to remove residues, i.e., particles, from the surface of the dried-etched wafer W.

[0077] The first cleaning fluid supply unit 5 has a first cleaning fluid supply flow path 100, a tank 101, and a circulation flow path 102. The first cleaning fluid supply flow path 100 supplies the first cleaning fluid to the tank 101.

[0078] The first cleaning fluid supply path 100 has a first cleaning fluid supply source 100a and a valve 100b sequentially from the upstream side. The first cleaning fluid supply source 100a is, for example, a tank for storing the first cleaning fluid (new fluid).

[0079] Tank 101 stores the first cleaning fluid supplied from the first cleaning fluid supply path 100. Circulation path 102 is a circulation path that starts from tank 101 and returns to tank 101.

[0080] In the circulation path 102, with tank 101 as the reference, pump 103, filter 104, heater 105, flow meter 106, valve 107, valve 108 and pressure regulating valve 109 are arranged sequentially from the upstream side.

[0081] Pump 103 creates a circulating flow of the first cleaning fluid that originates from tank 101, passes through circulation path 102, and returns to tank 101. Filter 104 removes contaminants such as particles contained in the first cleaning fluid circulating within circulation path 102.

[0082] Heater 105 heats the first cleaning fluid circulating in circulation path 102. Flow meter 106 measures the flow rate of the first cleaning fluid circulating in circulation path 102. Pressure regulating valve 109 controls the flow rate of the first cleaning fluid circulating in circulation path 102.

[0083] Additionally, tank 101 is connected to drain section DR via valve 110, and circulation path 102 is connected to drain section DR via valve 111. Therefore, control unit 18 (see reference) Figure 1 When changing the first cleaning fluid in tank 101 and circulation path 102, control valves 110 and 111 can discharge the first cleaning fluid in tank 101 and circulation path 102 to the drain section DR.

[0084] Additionally, a cleaning fluid supply path 112 branches off from between valves 107 and 108 in the circulation path 102. This cleaning fluid supply path 112 is located between the first cleaning fluid supply unit 5 and the processing unit 16, and supplies the first cleaning fluid, which has undergone filtration and temperature regulation by the first cleaning fluid supply unit 5, to the processing unit 16.

[0085] The cleaning fluid supply path 112 is provided with a confluence section 113, a flow meter 114, a pressure regulating valve 115, and a valve 116 in sequence from the upstream side. The confluence section 113 is connected to the second cleaning fluid supply path 152, and supplies second cleaning fluid from the second cleaning fluid supply section 7, which will be described in detail later.

[0086] That is, the cleaning fluid supply path 112 can supply the first cleaning fluid from the first cleaning fluid supply unit 5 to the processing unit 16, and can supply the second cleaning fluid from the second cleaning fluid supply unit 7 to the processing unit 16.

[0087] Flow meter 114 measures the flow rate of the first or second cleaning fluid flowing through the cleaning fluid supply path 112. Pressure regulating valve 115 controls the flow rate of the first or second cleaning fluid flowing within the cleaning fluid supply path 112.

[0088] In addition, the cleaning fluid supply path 112 is connected to the drain section DR via valve 117. Thus, the control unit 18 can control valve 117 to drain the cleaning fluid in the cleaning fluid supply path 112 to the drain section DR when the cleaning fluid in the cleaning fluid supply path 112 is replaced.

[0089] The drain port 51 of the processing unit 16 (refer to) Figure 2 It is connected to the cleaning fluid recovery unit 6 via the discharge flow path 120. Thus, the cleaning fluid used in the cleaning process of the wafer W in the processing unit 16 can be discharged to the cleaning fluid recovery unit 6.

[0090] The cleaning fluid recovery unit 6 recovers the cleaning fluid used in the cleaning process of the wafer W within the processing unit 16. The cleaning fluid recovery unit 6 includes a tank 121 connected to the discharge flow path 120 and a circulation flow path 122.

[0091] Tank 121 stores the cleaning fluid that has been used in the processing unit 16. Circulation path 122 is a circulation path that starts from tank 121 and returns to tank 121.

[0092] In the circulation path 122, with tank 121 as the reference, the upper pump 123, refrigeration unit 124, filter 125, flow meter 126, valve 127, valve 128 and pressure regulating valve 129 are arranged sequentially from the upstream side.

[0093] Pump 123 creates a circulating flow of used cleaning fluid from tank 121, through circulation path 122, and back to tank 121. Cooling unit 124 cools the used cleaning fluid circulating within circulation path 122.

[0094] The filter 125 removes contaminants such as particles from the used cleaning fluid cooled by the cooling unit 124. In this embodiment, the used cleaning fluid cooled by the cooling unit 124 is filtered by the filter 125, thereby enabling the used cleaning fluid to be reused for cleaning the wafer W.

[0095] Flow meter 126 measures the flow rate of the used cleaning fluid circulating in circulation path 122. Pressure regulating valve 129 controls the flow rate of the used cleaning fluid circulating in circulation path 122.

[0096] Furthermore, tank 121 is connected to drain section DR via valve 130, and circulation path 122 is connected to drain section DR via valve 131. Thus, control unit 18 can control valves 130 and 131 to discharge the used cleaning fluid in tank 121 and circulation path 122 to drain section DR when changing the used cleaning fluid in tank 121 and circulation path 122.

[0097] Additionally, a branch flow path 132 branches off from the filter 125 and the flow meter 126 in the circulation flow path 122. This branch flow path 132 is located between the cleaning fluid recovery unit 6 and the second cleaning fluid supply unit 7, and supplies the used cleaning fluid that has been filtered by the cleaning fluid recovery unit 6 to the second cleaning fluid supply unit 7.

[0098] A valve 133, a filter 134, and a valve 135 are sequentially installed from the upstream side of the branch flow path 132. The filter 134 removes contaminants such as particles contained in the used cleaning fluid flowing in the branch flow path 132.

[0099] The second cleaning fluid supply unit 7 supplies the used cleaning fluid, which has been filtered by the cleaning fluid recovery unit 6, to the processing unit 16 as the second cleaning fluid. This second cleaning fluid has been filtered by the cleaning fluid recovery unit 6; however, since it has already been used by the processing unit 16, its cleanliness is lower than that of the unused first cleaning fluid. Furthermore, in the following description, the second cleaning fluid will be referred to as "recovered fluid".

[0100] The second cleaning fluid supply unit 7 includes a tank 141 connected to a branch flow path 132 and a circulation flow path 142. The tank 141 stores the second cleaning fluid that has been filtered by the cleaning fluid recovery unit 6. The circulation flow path 142 is a circulation path that starts from the tank 141 and returns to the tank 141.

[0101] In the circulation path 142, with tank 141 as the reference, pump 143, filter 144, heater 145, flow meter 146, valve 147, valve 148 and pressure regulating valve 149 are arranged sequentially from the upstream side.

[0102] Pump 143 creates a circulating flow of the second cleaning fluid that originates from tank 141, passes through circulation path 142, and returns to tank 141. Filter 144 removes contaminants such as particles contained in the second cleaning fluid circulating within circulation path 142.

[0103] Heater 145 heats the second cleaning fluid circulating in circulation path 142. Flow meter 146 measures the flow rate of the second cleaning fluid circulating in circulation path 142. Pressure regulating valve 149 controls the flow rate of the second cleaning fluid circulating in circulation path 142.

[0104] Furthermore, tank 141 is connected to drain section DR via valve 150, and circulation path 142 is connected to drain section DR via valve 151. Thus, control unit 18 can control valves 150 and 151 to discharge the second cleaning fluid in tank 141 and circulation path 142 to drain section DR when changing the second cleaning fluid in tank 141 and circulation path 142.

[0105] Additionally, a second cleaning fluid supply flow path 152 branches off from between valves 147 and 148 in the circulation flow path 142. This second cleaning fluid supply flow path 152 is located between the confluence section 113 of the second cleaning fluid supply section 7 and the cleaning fluid supply flow path 112, and supplies the second cleaning fluid, which has undergone temperature regulation by the second cleaning fluid supply section 7, to the cleaning fluid supply flow path 112.

[0106] Additionally, a branch flow path 153 branches off from the second cleaning fluid supply flow path 152. This branch flow path 153 connects to the lower surface supply section 60 of the processing unit 16 (see reference). Figure 2 The second cleaning fluid, which has been temperature-regulated by the second cleaning fluid supply unit 7, is supplied to the lower surface supply unit 60 via a connection.

[0107] In branch flow path 153, a flow meter 154, a pressure regulating valve 155, and a valve 156 are sequentially installed from the upstream side. The flow meter 154 measures the flow rate of the second cleaning fluid circulating in branch flow path 153. The pressure regulating valve 155 controls the flow rate of the second cleaning fluid circulating in branch flow path 153.

[0108] <Substrate Processing>

[0109] Below, refer to Figures 4-7 The details of the substrate processing in the implementation method will be explained. Figure 4 This is a diagram illustrating the substrate processing steps of an implementation method.

[0110] For the dry-etched wafer W, substrate processing system 1 (refer to...) Figure 2 )like Figure 4 As shown in (a), the nozzle 41a is controlled to perform a first cleaning process by cleaning the front side of the wafer W with a first cleaning solution (fresh solution). Through this first cleaning process, the substrate processing system 1 is able to remove particles attached to the front side of the wafer W.

[0111] Furthermore, during this first cleaning process, the substrate processing system 1 controls the nozzle 61a to clean the back side of the wafer W with a second cleaning solution (recovery solution). Thus, the substrate processing system 1 is able to remove particles adhering to the back side of the wafer W.

[0112] Next, the substrate processing system 1, as... Figure 4 As shown in (b), nozzle 41a is controlled to perform a second cleaning process on the front side of wafer W using a second cleaning solution (recovery solution). Through this second cleaning process, substrate processing system 1 is able to remove particles on the front side that were not removed in the first cleaning process.

[0113] In addition, during the second cleaning process, the substrate processing system 1 continuously cleans the back side of the wafer W with the second cleaning solution (recycled solution).

[0114] Next, the substrate processing system 1, as... Figure 4 As shown in (c), the nozzle 41b is controlled to perform a rinsing process by rinsing the front side of the wafer W with functional water. Through this rinsing process, the substrate processing system 1 is able to remove the cleaning solution remaining on the front side of the wafer W.

[0115] Furthermore, during this rinsing process, the substrate processing system 1 controls the nozzle 61b to rinse the back side of the wafer W with functional water. Thus, the substrate processing system 1 is able to remove cleaning fluid residue remaining on the front side of the wafer W.

[0116] Finally, the substrate processing system 1 controls the liquid treatment unit 30 (see reference). Figure 2 To perform the drying process (e.g., rotary drying) on ​​wafer W (illustration omitted).

[0117] As described above, in the embodiment, when removing particles adhering to the front side of the wafer W, the front side of the wafer W is first cleaned with a fresh liquid with high cleanliness, and then cleaned with a recycled liquid with low cleanliness.

[0118] Here, the relationship between the timing of supplying the two cleaning solutions and the particles remaining on the wafer W is given when the new and recycled solutions are used separately in the cleaning process of wafer W. Figure 5 This is a graph showing the difference caused by the timing of the supply of recycled liquid and fresh liquid in the substrate processing of the embodiment.

[0119] also, Figure 5 An example is the result of setting the flow rate of the cleaning fluid released to the front side of the wafer W to 1500 (mL / min), the flow rate of the cleaning fluid released to the back side of the wafer W to 1000 (mL / min), and the processing time for the cleaning fluid treatment to 30 seconds.

[0120] like Figure 5 As shown, when the recovery solution was used throughout the entire cleaning process (30 seconds), the cleanliness of the recovery solution was low, so the number of particles remaining on the wafer W after cleaning increased.

[0121] Furthermore, when the recycled solution was used at the very beginning of the cleaning process (23 seconds) and a fresh solution was used in the next period (7 seconds), the number of particles remaining on the wafer W after cleaning was almost unchanged compared to the case where the recycled solution was used in all periods.

[0122] It is speculated that this is because when a low-cleanliness recovery solution is used in the initial period, the particles adhere firmly to the wafer W during that initial period, making it difficult to remove the firmly adhered particles even when a new solution is used in the next period.

[0123] On the other hand, as shown in the above embodiment, when new liquid is used in the initial period (5 seconds), recycled liquid is used in the next period (23 seconds), and new liquid is used in the final period (2 seconds), the number of particles remaining on the wafer W is greatly reduced regardless of whether the duration of using new liquid itself is changed.

[0124] It is speculated that this is because by using a fresh liquid with high cleanliness in the initial period, it is possible to inhibit the particles from adhering firmly to the wafer W, thus effectively removing the particles.

[0125] As described above, in this embodiment, by using a fresh liquid with high cleanliness at the very beginning of the cleaning process and a recycled liquid with low cleanliness in the next period, particles can be sufficiently removed from the front side of the wafer W compared to the case where a recycled liquid with low cleanliness is used.

[0126] Furthermore, in this embodiment, the recycled liquid can be used in the cleaning process, thus reducing the amount of fresh liquid required for the cleaning process. Therefore, according to this embodiment, the cost of the cleaning process can be reduced.

[0127] In addition, such as Figure 4 As shown, in the cleaning process of the embodiment, the amount of particles attached to the back side of the wafer W is less than that of the front side. Therefore, even if the back side is cleaned with a low-cleanliness recovery solution, there is no problem in practical application.

[0128] Furthermore, by using recycled liquid to clean the back side of wafer W throughout all periods, the amount of fresh liquid required for the cleaning process can be further reduced, thus further reducing the cost of the cleaning process.

[0129] Additionally, in the implementation method, functional water can be used in the rinsing process. Figure 6 This is a diagram illustrating the difference between DIW and functional water in the rinsing process of the embodiment.

[0130] also, Figure 6 The example is, besides with Figure 5 In addition to the same conditions, the results showed that, as functional water, a diluted ammonia solution with a concentration of 3 (ppmw) and a temperature of 25°C was used, and the flow rate of the DIW released to the front and back of the wafer W and the functional water was set to 1500 (mL / min).

[0131] like Figure 6 As shown, compared with the use of DIW in the rinsing process, the number of particles remaining on wafer W can be reduced by using functional water in the rinsing process.

[0132] The reasoning behind this result is speculated to be as follows: From the perspective of electromotive force, using alkaline functional water for rinsing treatment can cause the surface of particles remaining on the wafer W to become negatively charged.

[0133] Furthermore, the surface of the silicon wafer W is negatively charged, and in the embodiment, the adhesion of negatively charged particles can be suppressed by functional water.

[0134] Furthermore, in the embodiments, a case in which rinsing treatment was performed using functional water is given; however, rinsing treatment can also be performed using an alkaline treatment solution (e.g., SC1 (a mixture of ammonia and hydrogen peroxide aqueous solution)).

[0135] Therefore, in addition to imparting a negative charge to the particles, micro-etching the surface oxide film of wafer W removes the particles adhering to it. Thus, rinsing with an alkaline etching solution further reduces the number of particles remaining on wafer W.

[0136] In addition, in the embodiments, the filtration process of the cleaning fluid (e.g., the recovery fluid) can be carried out at a temperature lower than room temperature (25°C). Figure 7 This is a graph showing the temperature difference of the recovered liquid during the filtration process in the embodiment.

[0137] also, Figure 7 The example is the result of setting the flow rate of the cleaning fluid released to the front side of the wafer W to 1500 (mL / min), the flow rate of the cleaning fluid released to the back side of the wafer W to 1000 (mL / min), and the processing time of the cleaning fluid to 250 seconds.

[0138] like Figure 7 As shown, compared with the case of performing filtration at room temperature (25°C), the number of particles remaining on the wafer W can be reduced by performing filtration at temperatures lower than room temperature (20°C, 18°C).

[0139] This result is presumably based on the following reasoning. In filtration processes at temperatures lower than room temperature (hereinafter referred to as "low temperature"), compared to filtration processes at room temperature, filter 125 (reference) Figure 3 The membrane inside the membrane contracts.

[0140] As a result, the pore size of the membrane becomes narrower, thus enabling it to collect smaller particles compared to filter 125. Therefore, according to the embodiment, the filtration capacity of filter 125 can be improved.

[0141] Furthermore, in low-temperature filtration, the amount of particles dissolved from the membrane of filter 125 can be reduced compared to room-temperature filtration. This also improves the filtration capacity of filter 125.

[0142] <Various variations>

[0143] Below, refer to Figures 8 to 16 Various variations of the implementation method will be described. Figure 8 This is a diagram illustrating the substrate processing steps of Modified Example 1 of the implementation method. Furthermore, in the following examples, for... Figure 4 The same processing is used in the implementation methods shown, so the description is omitted.

[0144] For the dry-etched wafer W, substrate processing system 1 (refer to...) Figure 2 )like Figure 8 As shown in (a), nozzle 41a is controlled to clean the front side of wafer W with a first cleaning solution (fresh solution). Next, the substrate processing system 1... Figure 8 As shown in (b), nozzle 41a is controlled to clean the front side of wafer W with a second cleaning solution (recovery solution).

[0145] Next, the substrate processing system 1, as... Figure 8 As shown in (c), nozzle 41a is controlled to clean the front side of wafer W with a first cleaning solution (fresh solution). Then, substrate processing system 1... Figure 8 As shown in (d), nozzle 41b is controlled to rinse the front side of wafer W with functional water. Finally, substrate processing system 1 performs a drying process on wafer W (illustration omitted).

[0146] That is, in Modification 1, a cleaning process using a first cleaning solution is added between the second cleaning process and the rinsing process in the embodiment. This allows for the removal of front-side particles that were not removed in the second cleaning process.

[0147] Therefore, according to Modified Example 1, when using a recovery liquid with low cleanliness, particles can be further and more thoroughly removed from the front side of the wafer W.

[0148] Figure 9 This is a diagram illustrating the substrate processing steps of Modified Example 2 of the embodiment. For a wafer W that has undergone dry etching, the substrate processing system 1 (refer to...) Figure 2 )like Figure 9 As shown in (a), the nozzle 41a is controlled to clean the front side of the wafer W with the first cleaning fluid (new fluid).

[0149] Next, substrate processing system 1 Figure 9 As shown in (b), nozzle 41b is controlled to rinse the front side of wafer W with functional water. Then, substrate processing system 1... Figure 9 As shown in (c), the nozzle 41a is controlled to clean the front side of the wafer W with the first cleaning fluid (new fluid).

[0150] Next, the substrate processing system 1, as... Figure 8As shown in (d), nozzle 41b is controlled to rinse the front side of wafer W with functional water. Finally, substrate processing system 1 performs a drying process on wafer W (illustration omitted).

[0151] That is, in Modification 2, a rinsing process is added between the two cleaning processes performed with the first cleaning solution. This removes particles from the front side that were not removed in the initial cleaning process with the first cleaning solution. Therefore, according to Modification 2, particles can be sufficiently removed from the front side of the wafer W.

[0152] Figure 10 This is a diagram illustrating the substrate processing steps of Modified Example 3 of the embodiment. For a wafer W that has undergone dry etching, the substrate processing system 1 (refer to...) Figure 2 )like Figure 10 As shown in (a), the nozzle 41a is controlled to clean the front side of the wafer W with the first cleaning fluid (new fluid).

[0153] Next, the substrate processing system 1, as... Figure 10 As shown in (b), nozzle 41b is controlled to rinse the front side of wafer W with functional water. Then, substrate processing system 1... Figure 10 As shown in (c), the nozzle 41a is controlled to clean the front side of the wafer W with the second cleaning fluid (recovery fluid).

[0154] Next, the substrate processing system 1, as... Figure 10 As shown in (d), nozzle 41b is controlled to rinse the front side of wafer W with functional water. Finally, substrate processing system 1 performs a drying process on wafer W (illustration omitted).

[0155] That is, in Modification 3, a rinsing process is added between the first and second cleaning processes of the embodiment. This allows for the removal of front-side particles that were not removed in the first cleaning process.

[0156] Therefore, according to Modified Example 3, when using a recovery liquid with low cleanliness, particles can be sufficiently removed from the front side of the wafer W.

[0157] Figure 11 This is a schematic diagram showing the piping configuration of the substrate processing system 1 in Modified Example 4 of the embodiment. Figure 11 As shown, the substrate processing system 1 in Modified Example 4 differs from the embodiment described above in that it is provided with a second cleaning fluid supply path 136 for supplying a second cleaning fluid to the processing unit 16 from the cleaning fluid recovery unit 6. Therefore, in the following examples, for... Figure 3 The same reference numerals are used for the same parts in the embodiments shown, and the descriptions are omitted.

[0158] The second cleaning fluid supply path 136 branches off from the filter 134 and valve 135 in the branch path 132. In addition, the second cleaning fluid supply path 152 is provided with a merging section 157, which is connected to the second cleaning fluid supply path 136.

[0159] Thus, the substrate processing system 1 of Modified Example 4 can supply the recovered liquid, which has been filtered at low temperature in the cleaning liquid recovery unit 6, to the processing unit 16 at a low temperature.

[0160] Figure 12 This is a diagram illustrating the substrate processing steps of Modified Example 4 of the embodiment. For a wafer W that has undergone dry etching, the substrate processing system 1 (refer to...) Figure 11 )like Figure 12 As shown in (a), the nozzle 41a is controlled to clean the front side of the wafer W with a high-temperature first cleaning fluid (fresh fluid). This high-temperature fresh fluid can pass through the heater 105 of the first cleaning fluid supply unit 5 (see reference). Figure 11 It is generated by heating the new liquid.

[0161] As described above, by cleaning the front side of the wafer W with a fresh liquid at high temperature, and in cases where the DSP is used as the cleaning liquid, the etching rate can be increased when the surface of the wafer W is etched with the cleaning liquid.

[0162] Next, the substrate processing system 1, as... Figure 12 As shown in (b), the nozzle 41a is controlled to clean the front side of the wafer W with a low-temperature second cleaning fluid (recovery fluid). This low-temperature recovery fluid is supplied from the cleaning fluid recovery unit 6 via the second cleaning fluid supply path 136.

[0163] As described above, cleaning the front side of wafer W with a low-temperature recycled solution reduces the etching rate when etching the surface of wafer W with the cleaning solution. Therefore, by combining cleaning with a high-temperature fresh solution with cleaning with a low-temperature recycled solution, the total etching amount can be made consistent with a given value.

[0164] Next, the substrate processing system 1, as... Figure 12 As shown in (c), nozzle 41b is controlled to rinse the front side of wafer W with functional water. Finally, substrate processing system 1 performs a drying process on wafer W (illustration omitted).

[0165] Figure 13 This is a schematic diagram showing the piping configuration of the substrate processing system 1 in Modified Example 5 of the embodiment. (As shown) Figure 13 As shown, the substrate processing system 1 of Modified Example 5 differs from the embodiment in that a cooler 118 is provided in the circulation path 102 of the first cleaning fluid supply unit 5 instead of a heater 105.

[0166] The cooler 118 is located between the pump 103 and the filter 104 in the circulation path 102 to cool the first cleaning fluid (new fluid) circulating in the circulation path 102.

[0167] In Modification 5, by using the cooler 118, the filtration process of the first cleaning solution can be performed at a temperature lower than room temperature. Therefore, according to Modification 5, the cleanliness of the first cleaning solution can be further improved, thus further reducing the number of particles remaining on the wafer W.

[0168] In addition, in Modification 5, the new liquid that has been filtered at low temperature in the first cleaning liquid supply unit 5 can be supplied to the processing unit 16 at a low temperature.

[0169] Figure 14 This is a diagram illustrating the substrate processing steps of Modified Example 5 of the embodiment. For a wafer W that has undergone dry etching, the substrate processing system 1 (refer to...) Figure 13 ) Figure 14 As shown in (a), the nozzle 41a is controlled to clean the front side of the wafer W with a low-temperature first cleaning fluid (fresh fluid). This low-temperature fresh fluid is supplied from the first cleaning fluid supply unit 5.

[0170] As described above, by cleaning the front side of the wafer W with a fresh liquid at low temperature, and in cases where the DSP is used as the cleaning liquid, and when the surface of the wafer W is etched with the cleaning liquid, it is possible to achieve a state in which particles are difficult to adhere to the wafer W.

[0171] Next, the substrate processing system 1, as... Figure 14 As shown in (b), the nozzle 41a is controlled to clean the front side of the wafer W with a high-temperature second cleaning fluid (recovery fluid). This high-temperature recovery fluid can be generated by heating the recovery fluid using the heater 145 of the second cleaning fluid supply unit 7.

[0172] As described above, by cleaning the front side of wafer W with a high-temperature recycled solution, the etching rate can be increased when etching the surface of wafer W with the cleaning solution. Therefore, by combining the low-temperature cleaning process with the high-temperature cleaning process with the recycled solution, the total etching amount can be made consistent with a given value.

[0173] Next, the substrate processing system 1, as... Figure 14 As shown in (c), nozzle 41b is controlled to rinse the front side of wafer W with functional water. Finally, substrate processing system 1 performs a drying process on wafer W (illustration omitted).

[0174] In the embodiments and various modifications described so far, cases have been given in which unused cleaning fluid (i.e., new fluid) was used as the first cleaning fluid, but the first cleaning fluid in the embodiments is not limited to unused cleaning fluid.

[0175] Figure 15 This is a schematic diagram showing the piping configuration of the substrate processing system 1 in Modified Example 6 of the embodiment. (As shown) Figure 15 As shown, the substrate processing system 1 of Modified Example 6 differs from that of Modified Example 4 in that the branch flow path 132 is only connected to the confluence section 157, and the branch flow path 137 branches out from the discharge flow path 120 and is connected to the second cleaning fluid supply section 7.

[0176] A branch flow path 137 is provided between the processing unit 16 and the tank 141 of the second cleaning fluid supply unit 7 via a discharge flow path 120. By providing this branch flow path 137, the cleaning fluid already used in the processing unit 16 can be directly supplied to the second cleaning fluid supply unit 7.

[0177] Therefore, according to Modification 6, the cleaning fluid already used in the processing unit 16 can be filtered in the second cleaning fluid supply unit 7 at room temperature or a temperature higher than room temperature (hereinafter referred to as "high temperature").

[0178] In addition, in Modification 6, the branch flow path 132 is connected to the confluence section 157, thereby enabling the recovery liquid that has been filtered at low temperature in the cleaning liquid recovery section 6 to be directly supplied to the processing unit 16.

[0179] Figure 16 This is a diagram illustrating the substrate processing steps of Modification 6 of the embodiment. For a dry-etched wafer W, substrate processing system 1 (refer to...) Figure 15 )like Figure 16 As shown in (a), nozzle 41a is controlled to clean the front side of wafer W with a low-temperature filtered recovery solution.

[0180] Next, the substrate processing system 1, as... Figure 16 As shown in (b), nozzle 41a is controlled to clean the front side of wafer W with a recycled solution that has been filtered at room temperature. Then, substrate processing system 1 proceeds as follows: Figure 16 As shown in (c), nozzle 41b is controlled to rinse the front side of wafer W with functional water. Finally, substrate processing system 1 performs a drying process on wafer W (illustration omitted).

[0181] Here, in Modification 6, the recovered liquid filtered at low temperature has a higher cleanliness level compared to the recovered liquid filtered at room temperature. That is, in Modification 6, the recovered liquid filtered at low temperature becomes the first cleaning liquid, and the recovered liquid filtered at room temperature becomes the second cleaning liquid.

[0182] In this modified example 6, the cleaning process is initially performed using a first cleaning solution with high cleanliness, followed by a second cleaning solution with low cleanliness. Therefore, even when using a low-cleanliness recovery solution that has been filtered at room temperature, particles can be sufficiently removed from the front side of the wafer W.

[0183] Furthermore, in Modification 6, the recycled liquid can be used throughout the entire cleaning process, thus further reducing the amount of fresh liquid required for the cleaning process. Therefore, according to Modification 6, the cost of the cleaning process can be further reduced.

[0184] As described above, in this invention, a cleaning solution with a higher cleanliness level than the second cleaning solution can be used as the first cleaning solution. For example, a fresh solution that has been filtered at low temperature can be used as the first cleaning solution, and a fresh solution that has been filtered at room temperature or high temperature can be used as the second cleaning solution.

[0185] Alternatively, the fresh liquid that has been filtered at low temperature can be used as the first cleaning liquid, and the recovered liquid that has been filtered at low temperature, room temperature, or high temperature can be used as the second cleaning liquid.

[0186] Alternatively, the fresh liquid filtered at room temperature or high temperature can be used as the first cleaning liquid, and the recovered liquid filtered at low temperature, room temperature, or high temperature can be used as the second cleaning liquid.

[0187] The substrate processing apparatus (substrate processing system 1) of this embodiment includes a substrate processing unit (processing unit 16), a first cleaning fluid supply unit 5, a cleaning fluid recovery unit 6, and a second cleaning fluid supply unit 7. The substrate processing unit (processing unit 16) processes a substrate (wafer W). The first cleaning fluid supply unit 5 supplies unused cleaning fluid to the substrate processing unit (processing unit 16). The cleaning fluid recovery unit 6 recovers the cleaning fluid used in the substrate processing unit (processing unit 16). The second cleaning fluid supply unit 7 supplies the used cleaning fluid recovered by the cleaning fluid recovery unit 6 to the substrate processing unit (processing unit 16). Therefore, even when using a low-cleanliness recovery fluid, particles can be sufficiently removed from the wafer W.

[0188] Furthermore, the substrate processing apparatus (substrate processing system 1) of the embodiment also includes a control unit 18 that controls the substrate processing unit (processing unit 16), the first cleaning fluid supply unit 5, the cleaning fluid recovery unit 6, and the second cleaning fluid supply unit 7. The control unit 18 supplies unused cleaning fluid from the first cleaning fluid supply unit 5 and then supplies used cleaning fluid from the second cleaning fluid supply unit 7. Therefore, even when using a low-cleanliness recovery fluid, particles can be sufficiently removed from the wafer W.

[0189] Furthermore, in the substrate processing apparatus (substrate processing system 1) of the embodiment, the cleaning fluid recovery unit 6 has a filter 125 for filtering the recovered cleaning fluid. The filter 125 filters the recovered cleaning fluid at a temperature lower than room temperature. As a result, the number of particles remaining on the wafer W can be reduced.

[0190] <Steps for substrate processing>

[0191] Next, refer to Figure 17 The steps for substrate processing in the implementation method will be explained. Figure 17 This is a flowchart illustrating the steps of substrate processing performed by the substrate processing system 1 in the embodiment.

[0192] First, the control unit 18 controls the first cleaning solution supply unit 5 and the processing unit 16 to perform a first cleaning process of cleaning the wafer W with the first cleaning solution (step S101). Next, the control unit 18 controls the second cleaning solution supply unit 7 and the processing unit 16 to perform a second cleaning process of cleaning the wafer W with a second cleaning solution that has a lower cleanliness level than the first cleaning solution (step S103).

[0193] Next, the control unit 18 controls the functional water supply path 44 and the processing unit 16 to perform a rinsing process of the wafer W using functional water (step S103). Then, the control unit 18 controls the liquid treatment unit 30 to perform a drying process of the wafer W (step S104). At the end of step S104, a series of processes are completed.

[0194] The substrate processing method of this embodiment includes a first cleaning step (step S101) and a second cleaning step (step S102). In the first cleaning step (step S101), the substrate (wafer W) is cleaned with a first cleaning solution. In the second cleaning step (step S102), after the first cleaning step (step S101), the substrate (wafer W) is cleaned with a second cleaning solution that has a lower cleanliness level than the first cleaning solution. Therefore, even when using a recovery solution with lower cleanliness, particles can be sufficiently removed from the wafer W.

[0195] Furthermore, in the substrate processing method of this embodiment, the first cleaning solution is an unused cleaning solution, and the second cleaning solution is a used cleaning solution. This reduces the amount of fresh solution required for the cleaning process, thereby lowering the cost of the cleaning process.

[0196] Furthermore, in the substrate processing method of this embodiment, the second cleaning solution is a cleaning solution that has been filtered at a temperature lower than room temperature after use. This improves the cleanliness of the second cleaning solution, thereby reducing the number of particles remaining on the wafer W.

[0197] Furthermore, in the substrate processing method of this embodiment, the first cleaning solution is a cleaning solution that has been filtered at a temperature lower than room temperature in an unused state. This further improves the cleanliness of the first cleaning solution and reduces the number of particles remaining on the wafer W.

[0198] Furthermore, in the substrate processing method of this embodiment, the first cleaning solution is a cleaning solution that has been filtered at a temperature lower than room temperature after use, and the second cleaning solution is a cleaning solution that has been filtered at a temperature higher than room temperature after use. Therefore, the recycled solution can be used throughout the cleaning process, thus further reducing the amount of fresh solution required for the cleaning process.

[0199] Furthermore, the substrate processing method of the embodiment also includes a rinsing step (step S103) after the second cleaning step (step S102) of rinsing the substrate (wafer W) with functional water. This reduces the number of particles remaining on the wafer W.

[0200] Furthermore, in the substrate processing method of the embodiment, the first cleaning step (step S101) cleans the substrate (wafer W) with a first cleaning solution at a temperature above room temperature, and the second cleaning step (step S102) cleans the substrate (wafer W) with a second cleaning solution at a temperature lower than room temperature. This allows the total etching amount to be consistent with a given value.

[0201] Furthermore, in the substrate processing method of the embodiment, the first cleaning step (step S101) cleans the substrate (wafer W) with a first cleaning solution at a temperature lower than room temperature, and the second cleaning step (step S102) cleans the substrate (wafer W) with a second cleaning solution at a temperature higher than room temperature. This allows the total etching amount to be consistent with a given value.

[0202] The embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from its spirit. For example, in the embodiments described above, an acidic cleaning solution such as a DSP is used as the cleaning solution, but the cleaning solution in the embodiments is not limited to an acidic cleaning solution.

[0203] Furthermore, in the above embodiments, the case where the first cleaning fluid and the second cleaning fluid are the same type of cleaning fluid with different cleanliness is given, but the first cleaning fluid and the second cleaning fluid may also be cleaning fluids with different cleanliness and different types.

[0204] The embodiments disclosed herein are illustrative in all respects and should not be construed as limiting. In fact, the above-described embodiments can be implemented in a variety of ways. Furthermore, the above-described embodiments can be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

Claims

1. A method of processing a substrate, characterized by, include: The first cleaning step involves cleaning the front side of the substrate with the first cleaning solution; After the first cleaning step, a second cleaning step is performed to clean the front side of the substrate with a second cleaning solution that has a lower cleanliness level than the first cleaning solution. and Following the second cleaning step, the front side of the substrate is rinsed with functional water.

2. The substrate processing method as described in claim 1, characterized in that: The first cleaning solution is an unused cleaning solution. The second cleaning solution is the cleaning solution that has already been used.

3. The substrate processing method as described in claim 2, characterized in that: The second cleaning solution is a cleaning solution that has been filtered at a temperature lower than room temperature after use.

4. The substrate processing method as described in claim 2, characterized in that: The first cleaning solution is a cleaning solution that has been filtered at a temperature lower than room temperature in an unused state.

5. The substrate processing method as described in claim 1, characterized in that: The first cleaning solution is a cleaning solution that has been filtered at a temperature lower than room temperature after use. The second cleaning solution is a cleaning solution that has been filtered at a temperature above room temperature after use.

6. The substrate processing method according to any one of claims 1 to 5, characterized in that: In the first cleaning step, the front side of the substrate is cleaned with the first cleaning solution at a temperature above room temperature. In the second cleaning step, the front side of the substrate is cleaned with the second cleaning solution at a temperature lower than room temperature.

7. The substrate processing method according to any one of claims 1 to 5, characterized in that: In the first cleaning step, the front side of the substrate is cleaned with the first cleaning solution at a temperature lower than room temperature. In the second cleaning step, the front side of the substrate is cleaned with the second cleaning solution at a temperature above room temperature.

8. A substrate processing apparatus, characterized by, include: Substrate processing unit that processes substrates; A first cleaning solution supply unit that supplies the first cleaning solution to the substrate processing unit; A cleaning solution recovery unit that recovers the first cleaning solution used by the substrate processing unit; A second cleaning fluid, which is less clean than the first cleaning fluid and is recovered by the cleaning fluid recovery unit, is supplied to the second cleaning fluid supply unit of the substrate processing unit. Functional water supply source that supplies functional water to the substrate processing unit; and The control unit controls the substrate processing unit, the first cleaning fluid supply unit, the cleaning fluid recovery unit, and the second cleaning fluid supply unit. After the control unit supplies the first cleaning fluid from the first cleaning fluid supply unit to clean the front side of the substrate in the substrate processing unit, it supplies the second cleaning fluid from the second cleaning fluid supply unit to clean the front side of the substrate in the substrate processing unit. Then, it supplies the functional water from the functional water supply source to rinse the front side of the substrate in the substrate processing unit with the functional water.

9. The substrate processing apparatus as described in claim 8, characterized in that: The first cleaning solution is an unused cleaning solution. The second cleaning solution is the cleaning solution that has already been used.

10. The substrate processing apparatus as described in claim 8 or 9, characterized in that: The cleaning liquid recovery section has a filter that filters the recovered first cleaning liquid, The filter filters the recovered first cleaning liquid at a temperature lower than room temperature.

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