SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

Abstract

To prevent performance in liquid treatment from deteriorating after cleaning a substrate processing part.SOLUTION: A substrate processing device is provided with: a substrate processing part that makes a treatment liquid supply part supply treatment liquid to a placed substrate to perform a liquid treatment; a liquid ejecting part having a recovery path connected to a storage part storing the treatment liquid, and ejecting the treatment liquid used in the liquid treatment; and a control part that executes a processing recipe for the liquid treatment and a cleaning recipe for cleaning the substrate processing part and the liquid ejecting part. The liquid ejecting part has a mist guard having a first outer peripheral cylinder part and a first expanding part, a cup having a second outer peripheral cylinder part and a second expanding part, and a nozzle positioned on an upper surface of the second expanding part of the cup. The control part executes, as the cleaning recipe, cleaning operation of cleaning a lower surface of the first expanding part of the mist guard by making the nozzle supply cleaning liquid, and then executes return operation of replacing the cleaning liquid adhering to the lower surface of the first expanding part of the mist guard with the treatment liquid, by making the nozzle supply the treatment liquid that is used in the next processing recipe following the cleaning recipe.SELECTED DRAWING: Figure 6C

Description

[Technical field]

[0001] The disclosed embodiments relate to a substrate processing apparatus and a substrate processing method. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a technique for liquid processing substrates such as semiconductor wafers (hereinafter also referred to as wafers) with BHF (buffered hydrofluoric acid) in a single-wafer processing unit (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-41994 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique capable of suppressing deterioration in liquid processing performance after a substrate processing section has been subjected to a cleaning process. [Means for solving the problem]

[0005] A substrate processing apparatus according to an embodiment of the present disclosure includes a substrate processing unit, a drainage unit, and a control unit. The substrate processing unit performs liquid processing by supplying a processing liquid from a processing liquid supply unit to a substrate placed thereon. The drainage unit has a recovery path connected to a storage unit that stores the processing liquid, and drains the processing liquid used in the liquid processing. The control unit executes a processing recipe for the liquid processing and a cleaning recipe for cleaning the substrate processing unit and the drainage unit. The drainage unit has a mist guard, a cup, and a nozzle. The mist guard has a cylindrical first outer peripheral cylinder portion and a first protruding portion extending from an upper end portion of the first outer peripheral cylinder portion toward the inside of the first outer peripheral cylinder portion. The cup has a cylindrical second outer peripheral cylinder portion and a second protruding portion extending from an upper end portion of the second outer peripheral cylinder portion toward the inside of the second outer peripheral cylinder portion, and at least a part of the second protruding portion is located below the first protruding portion of the mist guard. A nozzle is positioned on the upper surface of the second overhanging portion of the cup and supplies liquid toward the underside of the first overhanging portion of the mist guard. The control unit executes a cleaning operation for supplying cleaning liquid from the nozzle to clean the underside of the first overhanging portion of the mist guard as the cleaning recipe, and then executes a return operation for supplying the processing liquid used in the next processing recipe of the cleaning recipe from the nozzle to replace the cleaning liquid adhering to the underside of the first overhanging portion of the mist guard with the processing liquid. Effect of the Invention

[0006] According to the present disclosure, it is possible to suppress deterioration of the liquid processing performance after the substrate processing section has been subjected to a cleaning process. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of a substrate processing system according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram illustrating an example of the configuration of a processing unit according to the embodiment. [Diagram 3] FIG. 3 is a schematic diagram showing a piping configuration of the substrate processing system according to the embodiment. [Figure 4] FIG. 4 is a schematic diagram showing a piping configuration of a storage unit according to the embodiment. [Diagram 5] FIG. 5 is a diagram for explaining a process flow in the substrate processing system according to the embodiment. [Figure 6A] FIG. 6A is a diagram (part 1) showing an operation example of the cleaning operation and the return operation according to the embodiment. [Figure 6B] FIG. 6B is a diagram (part 2) showing an operation example of the cleaning operation and the return operation according to the embodiment. [Figure 6C] FIG. 6C is a diagram (part 3) illustrating an example of the cleaning operation and the return operation according to the embodiment. [Figure 6D] FIG. 6D is a diagram (part 4) showing an operation example of the cleaning operation and the return operation according to the embodiment. [Figure 6E] FIG. 6E is a diagram (part 5) illustrating an example of the cleaning operation and the return operation according to the embodiment. [Figure 6F] FIG. 6F is a diagram (part 6) illustrating an example of the cleaning operation and the return operation according to the embodiment. [Figure 6G] FIG. 6G is a diagram (part 7) illustrating an example of the cleaning operation and the return operation according to the embodiment. [Figure 7] FIG. 7 is a diagram showing the relationship between the time of the return operation according to the embodiment and the amount of change in the etching rate in the subsequent process recipe. [Figure 8] FIG. 8 is a diagram for explaining a process flow in the substrate processing system according to the first modification of the embodiment. [Figure 9] FIG. 9 is a diagram for explaining a process flow in the substrate processing system according to the second modification of the embodiment. [Figure 10] FIG. 10 is a flowchart showing a procedure of substrate processing executed by the substrate processing system according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, with reference to the attached drawings, embodiments of the substrate processing apparatus and substrate processing method disclosed in the present application will be described in detail. Note that the present disclosure is not limited to the embodiments shown below. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from the reality. Furthermore, there may be parts in which the dimensional relationships and ratios of each element differ between the drawings.

[0009] Conventionally, a technique has been known in which substrates such as semiconductor wafers (hereinafter also referred to as wafers) are liquid-treated with BHF (buffered hydrofluoric acid) in a single-wafer processing section. BHF is a mixture of HF (hydrofluoric acid) and NHF (ammonium fluoride).

[0010] In such liquid processing using BHF, the BHF scattered during the liquid processing and attached to the substrate processing part may crystallize, and the crystals may adhere to the wafer as particles. Therefore, the crystallized BHF is periodically cleaned with a cleaning solution such as DIW (deionized water) to prevent particles caused by BHF from adhering to the wafer.

[0011] In addition, since BHF is a relatively expensive chemical, there are cases where BHF that has been used for liquid treatment is recovered from the drainage section to a storage section, and the used BHF is reused for liquid treatment.

[0012] However, since cleaning liquid (DIW) remains in the substrate processing section and the drainage section after the cleaning process, if BHF is collected in the storage section together with the DIW, the concentration of BHF may decrease, which may lead to a deterioration in the performance of the liquid processing using BHF.

[0013] Therefore, there is a need for a technique that overcomes the above-mentioned problems and can prevent the performance of the liquid processing from deteriorating after the substrate processing section has been cleaned.

[0014] <Outline of the substrate processing system> First, a schematic configuration of a substrate processing system 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing a schematic configuration of the substrate processing system 1 according to an embodiment. The substrate processing system 1 is an example of a substrate processing apparatus. In the following, to clarify the positional relationship, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other are defined, and the positive direction of the Z-axis is defined as a vertically upward direction.

[0015] 1, the substrate processing system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are provided adjacent to each other.

[0016] The carry-in / out station 2 includes a carrier placement section 11 and a transport section 12. On the carrier placement section 11, a plurality of carriers C are placed, each of which accommodates a plurality of substrates, in this embodiment, semiconductor wafers W (hereinafter referred to as wafers W), in a horizontal state.

[0017] The transfer section 12 is provided adjacent to the carrier placement section 11, and includes therein a substrate transfer device 13 and a transfer section 14. The substrate transfer device 13 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 13 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the carrier C and the transfer section 14 using the wafer holding mechanism.

[0018] The processing station 3 is provided adjacent to the transport section 12. The processing station 3 includes a transport section 15 and a plurality of processing units 16. The plurality of processing units 16 are provided side by side on both sides of the transport section 15.

[0019] The transfer section 15 includes a substrate transfer device 17 therein. The substrate transfer device 17 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 17 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the delivery section 14 and the processing unit 16 using the wafer holding mechanism.

[0020] The processing unit 16 performs a predetermined substrate processing on the wafer W transferred by the substrate transfer device 17 .

[0021] The substrate processing system 1 also includes a control device 4. The control device 4 is, for example, a computer, and includes a control unit 18 and a storage unit 19. The storage unit 19 stores programs for controlling various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading out and executing the programs stored in the storage unit 19.

[0022] Such a program may be recorded in a computer-readable storage medium and installed from that storage medium into the storage unit 19 of the control device 4. Examples of computer-readable storage media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card.

[0023] In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 in the loading / unloading station 2 takes out the wafer W from the carrier C placed on the carrier placement part 11, and places the taken-out wafer W on the transfer part 14. The wafer W placed on the transfer part 14 is taken out of the transfer part 14 by the substrate transfer device 17 in the processing station 3, and is carried into the processing unit 16.

[0024] The wafer W carried into the processing unit 16 is processed by the processing unit 16, and then carried out of the processing unit 16 by the substrate transfer device 17 and placed on the delivery section 14. Then, the processed wafer W placed on the delivery section 14 is returned to the carrier C of the carrier placement section 11 by the substrate transfer device 13.

[0025] <Processing unit configuration> Next, the configuration of the processing unit 16 will be described with reference to Fig. 2. Fig. 2 is a schematic diagram showing a specific configuration example of the processing unit 16. As shown in Fig. 2, the processing unit 16 includes a chamber 20, a substrate processing section 30, a liquid supply section 40, and a liquid drainage section 50.

[0026] The chamber 20 accommodates the substrate processing unit 30, the liquid supply unit 40, and at least a part of the liquid drainage unit 50. An FFU (Fan Filter Unit) 21 is provided on the ceiling of the chamber 20. The FFU 21 forms a downflow within the chamber 20.

[0027] The FFU 21 is connected to a downflow gas supply source 23 via a valve 22. The FFU 21 discharges a downflow gas (for example, dry air) supplied from the downflow gas supply source 23 into the chamber 20.

[0028] The substrate processing unit 30 includes a rotary holder 31, a support 32, and a drive unit 33, and performs liquid processing on the placed wafer W. The rotary holder 31 is provided approximately in the center of the chamber 20. A holding member 31a that holds the wafer W from the side is provided on the upper surface of the rotary holder 31. The wafer W is held horizontally by the holding member 31a at a slight distance from the upper surface of the rotary holder 31.

[0029] The support column 32 is a member extending in the vertical direction, with its base end rotatably supported by the drive unit 33 and its tip end horizontally supporting the rotation holder 31. The drive unit 33 rotates the support column 32 around a vertical axis.

[0030] The substrate processing unit 30 rotates the support member 32 using the drive unit 33, thereby rotating the rotary holder 31 supported by the support member 32, thereby rotating the wafer W held by the rotary holder 31.

[0031] The liquid supply unit 40 includes a first liquid supply unit 40a and a second liquid supply unit 40b. The first liquid supply unit 40a supplies various processing liquids to the wafer W held in the substrate processing unit 30. The first liquid supply unit 40a includes nozzles 41a to 41c, an arm 42a that horizontally supports the nozzles 41a to 41c, and a rotating and lifting mechanism 43a that rotates and raises and lowers the arm 42a.

[0032] The nozzles 41a to 41c are an example of a processing liquid supply unit. A first BHF having a first hydrofluoric acid concentration is discharged from the nozzle 41a onto the front surface of the wafer W. A second BHF having a second hydrofluoric acid concentration is discharged from the nozzle 41b onto the front surface of the wafer W.

[0033] From the nozzle 41c, a third BHF having a third hydrofluoric acid concentration is discharged onto the front surface of the wafer W. The first to third BHFs are examples of processing liquids. A piping configuration of the substrate processing system 1 including the nozzles 41a to 41c will be described later.

[0034] The second liquid supply unit 40b supplies DIW to the wafer W held in the substrate processing unit 30. The second liquid supply unit 40b includes a nozzle 41d, an arm 42b that horizontally supports the nozzle 41d, and a rotating and lifting mechanism 43b that rotates and raises and lowers the arm 42b.

[0035] From the nozzle 41d, DIW supplied through a DIW supply path (not shown) is discharged onto the front surface of the wafer W. The DIW is an example of a cleaning liquid, and the nozzle 41d is an example of a cleaning liquid supply unit.

[0036] First and second rotating cups 34, 35 that rotate integrally with the rotating holder 31 are provided on the periphery of the rotating holder 31. As shown in FIG. 2, the second rotating cup 35 is disposed on the inside of the first rotating cup 34.

[0037] The first rotating cup 34 and the second rotating cup 35 are formed in a ring shape as a whole. When the first and second rotating cups 34 and 35 are rotated together with the rotation holder 31, they guide the processing liquid scattered from the rotating wafer W to the drainage section 50.

[0038] Drainage unit 50 includes, in order from the inside close to the center of rotation of wafer W held and rotated by rotation holder 31, a first cup 50a, a second cup 50b, a third cup 50c, and a mist guard 50e. Drainage unit 50 further includes a bottom 53, an inner wall 54d, drainage paths 59a to 59c, and recovery paths 64a to 64c (see FIG. 3).

[0039] The inner wall portion 54d is a cylindrical member disposed on the inner periphery side of the first cup 50a and centered on the center of rotation of the wafer W. The first to third cups 50a to 50c, the mist guard 50e and the inner wall portion 54d are provided on the bottom portion 53 of the drainage portion 50.

[0040] The first cup 50a includes a first peripheral wall portion 54a and a first liquid receiving portion 55a. The first peripheral wall portion 54a stands upright from the bottom portion 53 and is formed in a tubular shape (for example, a cylindrical shape). A space is formed between the first peripheral wall portion 54a and the inner wall portion 54d, and this space serves as a first drainage groove 58a for collecting and discharging the processing liquid and the like. The first liquid receiving portion 55a is provided above an upper surface 54a1 of the first peripheral wall portion 54a.

[0041] Moreover, first cup 50a includes a first lifting mechanism 56, and first liquid receiving portion 55a is configured to be able to be raised and lowered by first lifting mechanism 56. In detail, first lifting mechanism 56 includes a first support member 56a and a first lifting drive portion 56b.

[0042] The first support members 56a are multiple (e.g., three; only one is shown in FIG. 2) long members. The first support members 56a are movably inserted into insertion holes formed in the first circumferential wall portion 54a. Note that the first support members 56a may be, for example, cylindrical rods, but are not limited thereto.

[0043] The first support member 56a is positioned such that its upper end is exposed from the upper surface 54a1 of the first circumferential wall portion 54a, and is connected to the lower surface of the first liquid receiving portion 55a to support the first liquid receiving portion 55a from below. Meanwhile, the first lifting drive portion 56b is connected to the lower end of the first support member 56a.

[0044] The first lifting drive unit 56b lifts and lowers the first support member 56a, for example, in the Z-axis direction, whereby the first support member 56a lifts and lowers the first liquid receiving portion 55a relative to the first circumferential wall portion 54a. An air cylinder can be used as the first lifting drive unit 56b. The first lifting drive unit 56b is controlled by the control device 4.

[0045] The first liquid receiving portion 55a, driven by the first lifting drive portion 56b, is moved between a processing position where it receives processing liquid splashed from the rotating wafer W, and a retracted position where it is retracted downward from the processing position.

[0046] Specifically, when the first liquid receiving portion 55a is in the processing position, an opening is formed on the inside of the upper end of the first liquid receiving portion 55a, and a flow path is formed that leads from the opening to the first drainage groove 58a.

[0047] 2, the inner wall portion 54d has an extension portion 54d1 that is extended and inclined toward the peripheral edge portion of the rotation holding portion 31. When the first liquid receiving portion 55a is in the retracted position, the first liquid receiving portion 55a abuts against the extension portion 54d1 of the inner wall portion 54d, and the opening on the inside of the upper end is closed, and the flow path leading to the first drainage groove 58a is blocked.

[0048] The second cup 50b has a similar configuration to the first cup 50a. Specifically, the second cup 50b includes a second peripheral wall portion 54b, a second liquid receiving portion 55b, and a second lifting mechanism 57, and is disposed adjacent to the first peripheral wall portion 54a side of the first cup 50a.

[0049] The second peripheral wall portion 54b is formed in a cylindrical shape and stands on the outer circumferential side of the first peripheral wall portion 54a at the bottom portion 53. The space formed between the second peripheral wall portion 54b and the first peripheral wall portion 54a serves as a second drainage groove 58b for collecting and discharging the treatment liquid and the like.

[0050] The second liquid receiving portion 55b is located on the outer circumferential side of the first liquid receiving portion 55a, and is provided above the upper surface 54b1 of the second peripheral wall portion 54b.

[0051] The second lifting mechanism 57 includes a second support member 57a and a second lifting drive unit 57b. The second support members 57a are multiple (e.g., three; only one is shown in FIG. 2) long members, and are movably inserted into insertion holes formed in the second circumferential wall unit 54b. Note that the second support members 57a may be, for example, cylindrical rods, but are not limited thereto.

[0052] The second support member 57a is positioned so that its upper end is exposed from the upper surface 54b1 of the second peripheral wall portion 54b, and is connected to the lower surface of the second liquid receiving portion 55b to support the second liquid receiving portion 55b from below. The upper surface 54b1 of the second peripheral wall portion 54b is positioned vertically below the upper surface 54a1 of the first peripheral wall portion 54a.

[0053] A second lifting drive unit 57b is connected to the lower end of the second support member 57a. The second lifting drive unit 57b lifts and lowers the second support member 57a, for example, in the Z-axis direction. As a result, the second support member 57a lifts and lowers the second liquid receiving portion 55b relative to the second circumferential wall portion 54b.

[0054] The second lifting drive unit 57b may be an air cylinder. The second lifting drive unit 57b is also controlled by the control device 4.

[0055] Then, the second liquid receiving portion 55b is also moved between the processing position and the retracted position. More specifically, when the second liquid receiving portion 55b is in the processing position and the first liquid receiving portion 55a is in the retracted position, an opening is formed on the inside of the upper end of the second liquid receiving portion 55b, and a flow path is formed that leads from the opening to the second drainage groove 58b.

[0056] 2, when the second liquid receiving portion 55b is in the retracted position, it abuts against the first liquid receiving portion 55a, closing the opening on the inside of the upper end and blocking the flow path leading to the second drainage groove 58b. Note that in the above description, the second liquid receiving portion 55b in the retracted position abuts against the first liquid receiving portion 55a, but this is not limited thereto, and it may abut against the inner wall portion 54d, for example, to close the opening on the inside of the upper end.

[0057] The third cup 50c includes a third peripheral wall portion 54c and a third liquid receiving portion 55c, and is disposed adjacent to the second cup 50b on the opposite side to the first cup 50a. The third peripheral wall portion 54c is erected on the outer circumferential side of the second peripheral wall portion 54b at the bottom portion 53, and is formed in a cylindrical shape. The space between the third peripheral wall portion 54c and the second peripheral wall portion 54b is formed as a third drainage groove 58c for collecting and discharging the treatment liquid and the like.

[0058] The third liquid receiving portion 55c is formed so as to be continuous with the upper end of the third peripheral wall portion 54c. The third liquid receiving portion 55c is formed so as to surround the periphery of the wafer W held by the rotating holder 31 and to extend above the first liquid receiving portion 55a and the second liquid receiving portion 55b.

[0059] As shown in Figure 2, when the first and second liquid receiving portions 55a, 55b are all in the retracted position, an opening is formed on the inside of the upper end of the third liquid receiving portion 55c, and a flow path is formed leading from the opening to the third drainage groove 58c.

[0060] On the other hand, when the second liquid receiving portion 55b is in a raised position, or when both the first liquid receiving portion 55a and the second liquid receiving portion 55b are in raised positions, the third liquid receiving portion 55c abuts the second liquid receiving portion 55b, closing the opening on the inner upper end and blocking the flow path leading to the third drainage groove 58c.

[0061] The bottom 53 corresponding to the first to third cups 50a to 50c, more precisely the bottom 53 corresponding to the first to third drainage grooves 58a to 58c, has drainage ports 51a to 51c formed at intervals along the circumferential direction of the drainage portion 50.

[0062] The drainage port 51a is connected to a drainage path 59a, the drainage port 51b is connected to a drainage path 59b, and the drainage port 51c is connected to a drainage path 59c. The piping configuration of the substrate processing system 1 including the drainage paths 59a to 59c will be described later.

[0063] When performing substrate processing, the substrate processing system 1 raises and lowers the first liquid receiving portion 55a of the first cup 50a and the second liquid receiving portion 55b of the second cup 50b, and switches the drainage ports 51a to 51c, depending on the type of processing liquid used in each step during substrate processing.

[0064] For example, when the first BHF is discharged onto the wafer W to process the wafer W, the controller 4 raises the first cup 50a and the second cup 50b. That is, the controller 4 raises the first and second support members 56a, 57a via the first and second elevation drivers 56b, 57b to raise the first liquid receiving portion 55a to the processing position, thereby forming a flow path leading from the opening on the inner upper end of the first liquid receiving portion 55a to the first drainage groove 58a.

[0065] As a result, the first BHF supplied to the wafer W flows into the first drainage groove 58a.

[0066] Furthermore, for example, when the second BHF is discharged onto the wafer W to process the wafer W, the controller 4 raises only the second cup 50b. That is, the controller 4 raises the second support member 57a via the second lifting drive unit 57b to raise the second liquid receiving unit 55b to the processing position, thereby forming a flow path leading from the opening on the inner upper end of the second liquid receiving unit 55b to the second drainage groove 58b.

[0067] It is assumed here that the first cup 50a is lowered, so that the second BHF supplied to the wafer W flows into the second drain groove 58b.

[0068] Furthermore, for example, when the third BHF is discharged onto the wafer W to process the wafer W, the controller 4 lowers the first and second cups 50a, 50b (see FIG. 2). That is, the controller 4 lowers the first and second support members 56a, 57a via the first and second lifting drives 56b, 57b, and lowers the first and second liquid receiving parts 55a, 55b to their retracted positions.

[0069] In this manner, a flow path is formed that leads from the opening on the inner side of the upper end of the third liquid receiving portion 55c to the third drainage groove 58c. As a result, the third BHF supplied to the wafer W flows into the third drainage groove 58c.

[0070] The mist guard 50e has an outer circumferential cylinder portion 50e1 and a protruding portion 50e2 extending from the upper end of the outer circumferential cylinder portion 50e1 toward the inside (radial direction) of the outer circumferential cylinder portion 54e and protruding above the third cup 50c. The mist guard 50e is configured to be movable up and down by a lifting mechanism (not shown).

[0071] The control unit 18 (see FIG. 1) can prevent the mist of the processing liquid scattered from the rotating wafer W from reaching the side wall of the chamber 20 by disposing the mist guard 50e at a high position.

[0072] Exhaust ports 52a, 52b, and 52c are formed in the bottom 53, the first peripheral wall portion 54a, and the second peripheral wall portion 54b of the drainage portion 50, respectively. The exhaust ports 52a, 52b, and 52c are connected to a single exhaust pipe 60, and a valve 61 is inserted in the exhaust pipe 60. The atmosphere in the chamber 20 is exhausted through the exhaust ports 52a, 52b, and 52c and the exhaust pipe 60.

[0073] <Piping configuration of substrate processing system> Next, a piping configuration of the substrate processing system 1 will be described with reference to Figures 3 and 4. Figure 3 is a schematic diagram showing the piping configuration of the substrate processing system 1 according to the embodiment.

[0074] 3, a drainage path 59a connected to a drain port 51a (see FIG. 2) of the processing unit 16 is connected to a switching valve 63a via a concentration sensor 62a. The concentration sensor 62a can detect the concentration of hydrofluoric acid in the drainage flowing through the drainage path 59a.

[0075] The switching valve 63a is connected to the drain section DR and the recovery path 64a. The switching valve 63a is configured to be able to switch the piping connected to the drainage path 59a to the drain section DR or the recovery path 64a. The control unit 18 (see FIG. 1) can switch the discharge path of the waste liquid flowing through the drainage path 59a to the drain section DR or the recovery path 64a by controlling the switching valve 63a.

[0076] In addition, the recovery path 64a is connected to a reservoir 70a that stores the first BHF. That is, the control unit 18 controls the switching valve 63a to allow flow between the drainage path 59a and the recovery path 64a, thereby allowing the first BHF used in the processing unit 16 to be recovered in the reservoir 70a.

[0077] Supply path 44a is connected to reservoir 70a, and supply path 44a is connected to nozzle 41a via valve 45a and flow rate regulator 46a. This allows controller 18 to discharge the first BHF stored in reservoir 70a from nozzle 41a onto wafer W. Details of reservoir 70a will be described later.

[0078] In addition, a standby unit 65a is provided below the standby position of the nozzle 41a in the chamber 20. During a dummy dispensing process for the purpose of removing air bubbles, foreign matter, and the like from each flow path connected to the nozzle 41a, the standby unit 65a receives the first BHF discharged from the nozzle 41a and drains the received first BHF to the upstream side of the concentration sensor 62a in the drainage path 59a. That is, the drainage path of the standby unit 65a is connected to the drainage path 59a.

[0079] Further, a drainage path 59b connected to a drain port 51b (see FIG. 2) of the processing unit 16 is connected to a switching valve 63b via a concentration sensor 62b. The concentration sensor 62b can detect the concentration of hydrofluoric acid in the drainage flowing through the drainage path 59b.

[0080] The switching valve 63b is connected to the drain section DR and the recovery path 64b. The switching valve 63b is configured to be able to switch the piping connected to the drainage path 59b to the drain section DR or the recovery path 64b. The control unit 18 can control the switching valve 63b to switch the discharge path of the waste liquid flowing through the drainage path 59b to the drain section DR or the recovery path 64b.

[0081] In addition, the recovery path 64b is connected to a reservoir 70b that stores the second BHF. That is, the control unit 18 controls the switching valve 63b to allow flow between the drainage path 59b and the recovery path 64b, thereby allowing the second BHF used in the processing unit 16 to be recovered in the reservoir 70b.

[0082] Supply path 44b is connected to reservoir 70b, and supply path 44b is connected to nozzle 41b via valve 45b and flow rate regulator 46b. This allows control unit 18 to discharge the second BHF stored in reservoir 70b from nozzle 41b onto wafer W.

[0083] In addition, a standby unit 65b is provided below the standby position of the nozzle 41b in the chamber 20. During a dummy dispensing process for the purpose of removing air bubbles, foreign matter, and the like from each flow path connected to the nozzle 41b, the standby unit 65b receives the second BHF discharged from the nozzle 41b and drains the received second BHF to the upstream side of the concentration sensor 62b in the drainage path 59b. That is, the drainage path of the standby unit 65b is connected to the drainage path 59b.

[0084] Furthermore, a drainage path 59c connected to a drain port 51c (see FIG. 2) of the processing unit 16 is connected to a switching valve 63c via a concentration sensor 62c. The concentration sensor 62c can detect the concentration of hydrofluoric acid in the drainage flowing through the drainage path 59c.

[0085] The switching valve 63c is connected to the drain section DR and the recovery path 64c. The switching valve 63c is configured to be able to switch the piping connected to the drainage path 59c to the drain section DR or the recovery path 64c. The control unit 18 can control the switching valve 63c to switch the discharge path of the waste liquid flowing through the drainage path 59c to the drain section DR or the recovery path 64c.

[0086] In addition, the recovery path 64c is connected to a reservoir 70c that stores the third BHF. That is, the control unit 18 controls the switching valve 63c to allow flow between the drainage path 59c and the recovery path 64c, thereby allowing the third BHF used in the processing unit 16 to be recovered in the reservoir 70c.

[0087] Supply path 44c is connected to reservoir 70c, and supply path 44c is connected to nozzle 41c via valve 45c and flow rate regulator 46c. This allows control unit 18 to discharge the third BHF stored in reservoir 70c from nozzle 41c onto wafer W.

[0088] Further, a standby unit 65c is provided below the standby position of the nozzle 41c in the chamber 20. During a dummy dispensing process for the purpose of removing air bubbles, foreign matter, and the like from each flow path connected to the nozzle 41c, the standby unit 65c receives the third BHF discharged from the nozzle 41c and drains the received third BHF to the upstream side of the concentration sensor 62c in the drainage path 59c. That is, the drainage path of the standby unit 65c is connected to the drainage path 59c.

[0089] 4 is a schematic diagram showing the piping configuration of the storage unit 70a according to the embodiment. Note that the piping configurations of the storage units 70b and 70c are similar to the piping configuration of the storage unit 70a described below, and therefore the description of the piping configurations of the storage units 70b and 70c will be omitted.

[0090] The reservoir 70a includes a BHF supply path 71a, a tank 74a, and a circulation path 75a. The BHF supply path 71a supplies unused first BHF to the tank 74a.

[0091] The BHF supply line 71a includes, in order from the upstream side, a BHF supply source 72a and a valve 73a. The BHF supply source 72a is, for example, a tank that stores unused first BHF.

[0092] Tank 74a stores the first BHF supplied from BHF supply path 71a, and also stores the used first BHF recovered via drainage path 59a and recovery path 64a.

[0093] The circulation path 75a is a circulation path that exits from the tank 74a and returns to the tank 74a. In the circulation path 75a, a pump 76a, a filter 77a, a heater 78a, a valve 79a, a switching valve 80a, a concentration sensor 81a, and a switching valve 82a are provided in this order from the upstream side with respect to the tank 74a.

[0094] The pump 76a creates a circulation flow of the first BHF from the tank 74a, through the circulation path 75a, and back to the tank 74a. The filter 77a removes contaminants such as particles contained in the first BHF circulating in the circulation path 75a.

[0095] The heater 78a heats the first BHF circulating through the circulation path 75a. The concentration sensor 81a can detect the concentration of hydrofluoric acid in the first BHF flowing through the circulation path 75a.

[0096] A DIW supply source 83a is connected to the upstream side of the switching valve 80a, and a downstream side of the switching valve 82a is connected to the drain section DR. The control unit 18 (see FIG. 1) controls the switching valves 80a and 82a so that the DIW supply source 83a is connected to the drain section DR via the concentration sensor 81a, thereby cleaning the inside of the concentration sensor 81a with DIW.

[0097] Therefore, according to the embodiment, the concentration sensor 81a can be calibrated by cleaning the inside of the concentration sensor 81a with DIW.

[0098] Furthermore, the tank 74a is connected to the drain section DR via a valve 84a, and the circulation path 75a is connected to the drain section DR via a valve 85a. This allows the control unit 18 to control the valves 84a and 85a when replacing the first BHF in the tank 74a or the circulation path 75a, and to discharge the first BHF in the tank 74a or the circulation path 75a to the drain section DR.

[0099] In addition, a supply path 44a branches off from the circulation path 75a between the heater 78a and the valve 79a. The supply path 44a is interposed between the circulation path 75a and the nozzle 41a (see FIG. 3), and supplies the first BHF that has been subjected to the filtration process and the temperature adjustment process in the circulation path 75a to the processing unit 16.

[0100] <Substrate processing> Next, details of each process in the substrate processing system 1 according to the embodiment will be described with reference to Fig. 5 to Fig. 7. Fig. 5 is a diagram for explaining the flow of processes in the substrate processing system 1 according to the embodiment.

[0101] As shown in FIG. 5, in a substrate processing system 1 according to the embodiment, in a processing unit 16, liquid processing using any one of first to third BHFs is continuously performed on a wafer W according to a processing recipe S1 corresponding to the BHF used.

[0102] The process recipe S1 according to the embodiment includes the processing sequence of the wafer W and the types of processing liquids, and is stored in advance in the storage unit 19 (see FIG. 1). That is, a plurality of process recipes S1 according to the embodiment are prepared according to different types of BHF. This allows the processing unit 16 to perform liquid processing optimized for each of the different types of BHF.

[0103] In addition, in the example of Figure 5, the process recipe S1 for liquid processing performed before the target cleaning recipe S2 is designated as process recipe S1a, and the process recipe S1 for liquid processing performed after the target cleaning recipe S2 is designated as process recipe S1b.

[0104] In the substrate processing system 1, the cleaning recipe S2 is executed between the repeatedly executed processing recipes S1 in the processing unit 16. The cleaning recipe S2 includes a cleaning operation S3 and a return operation S4.

[0105] In the cleaning operation S3, DIW, which is a cleaning liquid, is supplied from a cleaning liquid supply unit (for example, nozzle 41d) to clean the substrate processing unit 30 and the drainage unit 50. This makes it possible to remove crystals resulting from BHF that have adhered to the substrate processing unit 30 and the drainage unit 50 in the process recipe S1a up until the execution of the cleaning operation S3.

[0106] The return operation S4, for example, supplies BHF to be used in the next processing recipe S1b (hereinafter also referred to as "BHF for the next process") from a processing liquid supply unit (for example, nozzles 41a to 41c) and replaces the DIW adhering to the substrate processing unit 30 and the drainage unit 50 with BHF for the next process.

[0107] That is, in the embodiment, in the return operation S4, the DIW remaining in the substrate processing unit 30 and the drainage unit 50 after the cleaning operation S3 is co-washed with the BHF of the next process. This makes it possible to prevent the DIW remaining in the substrate processing unit 30 and the drainage unit 50 after the cleaning operation S3 from being collected in the reservoirs 70a to 70c.

[0108] Therefore, according to the embodiment, even if liquid processing is performed while recovering BHF for the next process in the subsequent processing recipe S1b, a decrease in the concentration of the recovered BHF can be suppressed, thereby suppressing deterioration of the liquid processing performance.

[0109] In the embodiment, the controller 18 may select the cleaning recipe S2 based on the process recipe S1. For example, the controller 18 may select the cleaning recipe S2 based on the type of BHF used in the process recipe S1.

[0110] Next, the cleaning operation S3 and the return operation S4 will be described in detail with reference to Figures 6A to 6G. Figures 6A to 6G are diagrams (parts 1 to 7) showing examples of the cleaning operation and the return operation according to the embodiment.

[0111] 6A, the cleaning operation S3 is, for example, a process for cleaning the rotating holder 31, the holding member 31a, the first rotating cup 34, and the second rotating cup 35. In this case, for example, while the rotating holder 31 is rotating, the nozzle 41d is reciprocated between the center and the outer periphery of the rotating holder 31 while the nozzle 41d is supplied with DIW.

[0112] As a result, crystals adhering to the rotating holder 31, the holding member 31a arranged on the outer periphery of the rotating holder 31, the first rotating cup 34, and the second rotating cup 35 can be removed.

[0113] Similarly, the return operation S4 is, for example, a process of washing the spin holder 31, the holding member 31a, the first spin cup 34, and the second spin cup 35 together with the BHF of the next process. In this case, for example, while the spin holder 31 is rotating, any one of the nozzles 41a to 41c (see FIG. 2) is reciprocated between the center and the outer periphery of the spin holder 31, and the BHF of the next process is supplied from the nozzle.

[0114] This allows the DIW adhering to the rotating holder 31, the holding member 31a arranged on the outer periphery of the rotating holder 31, the first rotating cup 34, and the second rotating cup 35 to be replaced with the BHF in the next process.

[0115] 6B, the cleaning operation S3 is, for example, a process for cleaning the first to third drainage grooves 58a to 58c. In this case, the processing unit 16 includes a cleaning liquid supply part 100 that supplies DIW, which is a cleaning liquid, to the first drainage groove 58a.

[0116] The cleaning liquid supply unit 100 includes a cleaning liquid supply path 100a, a DIW supply source 100b, a valve 100c, and a flow rate regulator 100d. One end of the cleaning liquid supply path 100a is connected to the DIW supply source 100b, and the other end is connected to the drain port 51a of the first cup 50a. The valve 100c and the flow rate regulator 100d are provided in the cleaning liquid supply path 100a and are controlled by the control device 4.

[0117] 6B, the valve 100c is opened for a predetermined time to supply DIW to the first drainage groove 58a. As a result, the DIW is stored in the first drainage groove 58a, and the DIW stored in the first drainage groove 58a flows over the upper surface 54a1 of the first peripheral wall portion 54a and overflows into the second drainage groove 58b, causing the DIW to be stored in the second drainage groove 58b.

[0118] Furthermore, the DIW stored in the second drainage groove 58b flows over the upper surface 54b1 of the second peripheral wall portion 54b and overflows into the third drainage groove 58c, so that the DIW is also stored in the third drainage groove 58c.

[0119] Thereafter, the DIW is discharged from each of the drainage ports 51a to 51c, whereby the crystals adhering to the first to third drainage grooves 58a to 58c can be removed.

[0120] Similarly, the return operation S4 is, for example, a process of co-washing the first to third drainage grooves 58a to 58c with BHF for the next process. In this case, the processing unit 16 includes a processing liquid supply part 101 that supplies BHF for the next process to the first drainage groove 58a.

[0121] The processing liquid supply unit 101 includes a processing liquid supply path 101a, a switching valve 101b, and a flow rate regulator 101c. One end of the processing liquid supply path 101a is connected to each of the storage units 70a to 70c via the switching valve 101b, and the other end is connected to the drain port 51a of the first cup 50a. The switching valve 101b and the flow rate regulator 101c are provided in the processing liquid supply path 101a and are controlled by the control device 4.

[0122] In the return operation S4 shown in FIG. 6B, the switching valve 101b is controlled to connect any one of the storage units 70a to 70c in which the BHF for the next process is stored to the first drainage groove 58a, and the BHF for the next process is supplied to the first drainage groove 58a.

[0123] As a result, the BHF for the next process is stored in the first drainage groove 58a, and the BHF for the next process stored in the first drainage groove 58a passes over the upper surface 54a1 of the first peripheral wall portion 54a and overflows into the second drainage groove 58b, causing the BHF for the next process to be stored in the second drainage groove 58b.

[0124] Furthermore, the BHF for the next process stored in the second drainage groove 58b passes over the upper surface 54b1 of the second peripheral wall portion 54b and overflows into the third drainage groove 58c, so that the BHF for the next process is also stored in the third drainage groove 58c.

[0125] Thereafter, the BHF for the next process is discharged from each of the drainage ports 51a to 51c, whereby the DIW adhering to the first to third drainage grooves 58a to 58c can be replaced with the BHF for the next process.

[0126] As shown in Fig. 6C, an exhaust cup 50d may be disposed inside the chamber 20 between the third cup 50c (see Fig. 2) and the mist guard 50e. The exhaust cup 50d includes an outer circumferential cylinder portion 50d1 and a protruding portion 50d2 that protrudes from the upper end of the outer circumferential cylinder portion 50d1 toward the radial inside of the outer circumferential cylinder portion 50d1. The exhaust cup 50d is stationary.

[0127] In such a case, the cleaning operation S3 is, for example, a process for cleaning the lower surface of the overhanging portion 50e2 of the mist guard 50e and the upper surface of the overhanging portion 50d2 of the exhaust cup 50d. In this case, the processing unit 16 includes, for example, a cleaning liquid supply unit 110 that supplies cleaning liquid to the lower surface of the overhanging portion 50e2 of the mist guard 50e.

[0128] The cleaning liquid supply unit 110 includes a cleaning liquid supply path 110a, a DIW supply source 110b, a valve 110c, and a flow rate regulator 110d. One end of the cleaning liquid supply path 110a is connected to the DIW supply source 110b, and the other end is connected to a nozzle 41e provided on the upper surface of the protruding portion 50d2 of the exhaust cup 50d. The valve 110c and the flow rate regulator 110d are provided in the cleaning liquid supply path 110a and are controlled by the control device 4.

[0129] In the cleaning operation S3 shown in Fig. 6C, DIW is supplied from the nozzle 41e to store DIW in the space between the overhanging portion 50e2 of the mist guard 50e and the overhanging portion 50d2 of the exhaust cup 50d. The DIW is then discharged from a drainage path (not shown). This makes it possible to remove crystals adhering to the lower surface of the overhanging portion 50e2 of the mist guard 50e and the upper surface of the overhanging portion 50d2 of the exhaust cup 50d.

[0130] Similarly, the return operation S4 is, for example, a process of washing the lower surface of the overhanging portion 50e2 of the mist guard 50e and the upper surface of the overhanging portion 50d2 of the exhaust cup 50d together with the BHF of the next process. In this case, the processing unit 16 includes a processing liquid supply part 111 that supplies the BHF of the next process to the nozzle 41e.

[0131] The processing liquid supply unit 111 includes a processing liquid supply path 111a, a switching valve 111b, and a flow rate regulator 111c. One end of the processing liquid supply path 111a is connected to each of the storages 70a to 70c via the switching valve 111b, and the other end is connected to the nozzle 41e. The switching valve 111b and the flow rate regulator 111c are provided in the processing liquid supply path 111a and are controlled by the control device 4.

[0132] In the return operation S4 shown in FIG. 6C, the switching valve 111b is controlled to connect any one of the storage units 70a to 70c in which the BHF for the next process is stored to the nozzle 41e, and the BHF for the next process is supplied to the nozzle 41e.

[0133] This allows the BHF for the next process to be stored in the space between the overhanging portion 50e2 of the mist guard 50e and the overhanging portion 50d2 of the exhaust cup 50d. The BHF for the next process is then discharged from a drainage path (not shown). This allows the DIW attached to the lower surface of the overhanging portion 50e2 of the mist guard 50e and the upper surface of the overhanging portion 50d2 of the exhaust cup 50d to be replaced with the BHF for the next process.

[0134] 6D, the cleaning operation S3 is, for example, a process for cleaning the lower surface of the spin holder 31 of the substrate processing section 30. In this case, the processing unit 16 includes a cleaning liquid supplying section 120 that supplies a cleaning liquid to the lower surface of the spin holder 31.

[0135] The cleaning liquid supply unit 120 includes a nozzle 41f. The nozzle 41f is provided, for example, at an upper end of the inner wall portion 54d. The cleaning liquid supply unit 120 also includes a cleaning liquid supply path 120a, a DIW supply source 120b, a valve 120c, and a flow rate regulator 120d.

[0136] The cleaning liquid supply path 120a has one end connected to the DIW supply source 120b and the other end connected to the nozzle 41f. The valve 120c and the flow rate regulator 120d are provided on the cleaning liquid supply path 120a and are controlled by the controller 4.

[0137] 6D, DIW is supplied from the nozzle 41f to the lower surface of the rotating spin holder 31. This makes it possible to remove crystals adhering to the lower surface of the spin holder 31.

[0138] Similarly, the return operation S4 is, for example, a process of co-washing the lower surface of the spin holder 31 of the substrate processing section 30 with BHF for the next process. In this case, the processing unit 16 includes a processing liquid supply section 121 that supplies BHF for the next process to the nozzle 41f.

[0139] The processing liquid supply unit 121 includes a processing liquid supply path 121a, a switching valve 121b, and a flow rate regulator 121c. One end of the processing liquid supply path 121a is connected to each of the storages 70a to 70c via the switching valve 121b, and the other end is connected to the nozzle 41f. The switching valve 121b and the flow rate regulator 121c are provided in the processing liquid supply path 121a and are controlled by the controller 4.

[0140] 6D, the switching valve 121b is controlled to connect the nozzle 41f to any one of the storage units 70a-70c in which the BHF for the next process is stored, and the BHF for the next process is supplied to the nozzle 41f. Then, by supplying the BHF for the next process from the nozzle 41f to the lower surface of the rotating spin holder 31, the DIW adhering to the lower surface of the spin holder 31 can be replaced with the BHF for the next process.

[0141] 6E, the cleaning operation S3 is, for example, a process for cleaning standby sections 65a to 65c provided in the chamber 20. In this case, the processing unit 16 includes a cleaning liquid supply section 130 that supplies a cleaning liquid to the standby sections 65a to 65c. In the following, for ease of understanding, each operation for the standby section 65a shown in FIG. 6E will be described.

[0142] The cleaning liquid supply unit 130 includes a cleaning liquid supply path 130a, a DIW supply source 130b, a valve 130c, and a flow rate regulator 130d. One end of the cleaning liquid supply path 130a is connected to the DIW supply source 130b, and the other end is connected to the standby unit 65a. The valve 130c and the flow rate regulator 130d are provided in the cleaning liquid supply path 130a and are controlled by the control device 4.

[0143] In the cleaning operation S3 shown in Fig. 6E, after storing the DIW in the standby section 65a for a predetermined time, the DIW is discharged from the standby section 65a to the drainage path 59a (see Fig. 3). This makes it possible to remove crystals adhering to the standby section 65a.

[0144] Similarly, the return operation S4 is, for example, a process of co-washing the standby section 65a provided in the chamber 20 with BHF for the next process. In this case, the processing unit 16 includes a processing liquid supply section 131 that supplies BHF for the next process to the standby section 65a.

[0145] The processing liquid supply unit 131 includes a processing liquid supply path 131a, a valve 131b, and a flow rate regulator 131c. One end of the processing liquid supply path 131a is connected to a corresponding storage unit 70a via the valve 131b, and the other end is connected to the standby unit 65a. The valve 131b and the flow rate regulator 131c are provided in the processing liquid supply path 131a and are controlled by the control device 4.

[0146] In the return operation S4 shown in FIG. 6E, the valve 131b is controlled to connect the storage unit 70a, in which the BHF for the next process is stored, to the standby unit 65a, and the BHF for the next process is supplied to the standby unit 65a.

[0147] Then, after the BHF for the next process is stored in the standby section 65a for a predetermined time, the BHF for the next process is discharged from the standby section 65a to the drainage path 59a. This allows the DIW adhering to the standby section 65a to be replaced with the BHF for the next process.

[0148] 6F, a back surface nozzle 47 that discharges a processing liquid or the like onto the back surface of the wafer W may be disposed inside the chamber 20. The back surface nozzle 47 is an example of a back surface supply unit. The back surface nozzle 47 is disposed to face the back surface of the wafer W held by the holding member 31a, and discharges a processing liquid or the like in an upward direction.

[0149] The back surface nozzle 47 has a processing liquid outlet 47a for outletting the first to third BHFs as processing liquids, and a cleaning liquid outlet 47b for outletting the DIW as a cleaning liquid. By providing the back surface nozzle 47 in the processing unit 16, not only the front surface of the wafer W but also the back surface of the wafer W can be liquid-processed with the BHF.

[0150] 6F(a), for example, in a state where the wafer W is not held by the holding member 31a, DIW is supplied from the nozzle 41d while the nozzle 41d is reciprocated between the center and the outer periphery of the back surface nozzle 47. This makes it possible to remove crystals adhering to the back surface nozzle 47.

[0151] 6F(b) is, for example, a process of washing the rear surface nozzle 47 with BHF for the next process. In this case, for example, in a state where the wafer W is not held by the holding member 31a, one of the nozzles 41a to 41c (nozzle 41a in the figure) is reciprocated between the center and the outer periphery of the rear surface nozzle 47, and BHF for the next process is supplied from the nozzle. This allows the DIW attached to the rear surface nozzle 47 to be replaced with BHF for the next process.

[0152] The cleaning operation S3 and the return operation S4 of the rear surface nozzle 47 are not limited to the example shown in Fig. 6F. For example, as shown in Fig. 6G(a), the cleaning operation S3 of the rear surface nozzle 47 may be performed by discharging DIW, which is a cleaning liquid, from the cleaning liquid discharge port 47b and causing the DIW to overflow on the rear surface nozzle 47. This makes it possible to remove crystals adhering to the rear surface nozzle 47.

[0153] 6G(b), a return operation S4 of the back surface nozzle 47 may be performed by discharging the BHF for the next process from the processing liquid discharge port 47a and causing the BHF for the next process to overflow onto the back surface nozzle 47. This allows the DIW adhering to the back surface nozzle 47 to be replaced with the BHF for the next process.

[0154] 6F and the cleaning operation S3 and the return operation S4 shown in FIG 6G may be combined to execute a cleaning recipe S2. For example, after performing the cleaning operation S3 by supplying DIW from the nozzle 41d, the return operation S4 may be performed by discharging BHF for the next process from the processing liquid discharge port 47a of the back surface nozzle 47.

[0155] Similarly, after performing the cleaning operation S3 by discharging DIW from the cleaning liquid discharge port 47b of the rear surface nozzle 47, the return operation S4 may be performed by supplying BHF for the next process from any of the nozzles 41a to 41c.

[0156] In the cleaning operation S3 and the return operation S4 in each part described above, the control unit 18 may control the switching valves 63a to 63c (see FIG. 3) to discharge the waste liquid flowing in the waste liquid paths 59a to 59c from the drain unit DR to the outside.

[0157] Fig. 7 is a diagram showing the relationship between the time of the return operation S4 according to the embodiment and the amount of change in the etching rate in the process recipe S1b thereafter. Fig. 7 shows the return operation S4 for the waiting sections 65a-65c (see Fig. 6E) and the return operation S4 for the first to third drainage grooves 58a-58c (see Fig. 6B).

[0158] 7, when the time of the return operation S4 is relatively short, the etching rate is significantly reduced in the subsequent process recipe S1. This is because, when the time of the return operation S4 is relatively short, a relatively large amount of DIW used in the cleaning operation S3 remains in the substrate processing unit 30 and the drainage unit 50, so that the DIW gets mixed into the BHF recovered in the subsequent process recipe S1b, and the concentration of the BHF to be reused is reduced.

[0159] On the other hand, as shown in FIG. 7, by taking a long time for the return operation S4, the etching rate in the subsequent process recipe S1 can be maintained within an appropriate range.

[0160] In other words, by discharging the waste liquid flowing in the drainage paths 59a to 59c to the outside through the drain section DR during the cleaning operation S3 and the return operation S4, it is possible to prevent the cleaning liquid DIW and the BHF containing this DIW from being recovered in the storage sections 70a to 70c.

[0161] Furthermore, in the embodiment, by performing the restoration operation S4 for a time according to the BHF of the next process, the etching rate in the subsequent process recipe S1b can be maintained within an appropriate range even if reused BHF is used.

[0162] As described above, according to the embodiment, it is possible to suppress a decrease in the concentration of recovered BHF, and therefore it is possible to suppress deterioration of the liquid treatment performance.

[0163] The above-mentioned "return operation S4 of the time according to the BHF of the next process" may be included in advance in the cleaning recipe S2 corresponding to the type of BHF included in the process recipe S1b of the next process, depending on the type of BHF included in the process recipe S1b of the next process. That is, in the embodiment, the cleaning recipe S2 may be selected based on the process recipe S1b of the next process of the cleaning recipe S2.

[0164] For example, when a first BHF is used in the process recipe S1b of the next process, the control unit 18 may read out a cleaning recipe S2 in which the first BHF is used in the return operation S4 from the storage unit 19. The read out cleaning recipe S2 includes the execution time of the return operation S4 corresponding to the first BHF.

[0165] In this way, by selecting the cleaning recipe S2 based on the process recipe S1b for the next process, the liquid processing for the next process can be started in a state where the substrate processing unit 30 and the like are replaced with BHF used in the process recipe S1b for the next process. Therefore, according to the embodiment, when the BHF used in the process recipe S1b is recovered and reused, it is possible to suppress a change in the concentration of BHF, and therefore the liquid processing for the next process can be stably performed.

[0166] In addition, in the embodiment, in the return operation S4, when BHF for the next process is discharged from any one of the nozzles 41a to 41c for co-washing, the wafer W may be subjected to liquid processing using the discharged BHF for the next process.

[0167] This allows the liquid processing of the wafer W to be performed during the returning operation S4, so that the processing unit 16 can be quickly returned to the liquid processing.

[0168] <Various modified examples> Next, various modified examples of the embodiment will be described with reference to Figures 8 and 9. Figure 8 is a diagram for explaining the flow of processing in the substrate processing system 1 according to Modification 1 of the embodiment.

[0169] 8, the cleaning recipe S2 according to the first modification is different from the embodiment in that a gas purge operation S5 is performed between a cleaning operation S3 and a return operation S4. In the first modification, the processing unit 16 has a gas supply part (not shown) that purges the substrate processing part 30 and the drainage part 50 with a gas.

[0170] In the first modification, after the control unit 18 (see FIG. 1) executes the cleaning operation S3, a gas purge operation S5 is executed in which gas is supplied from the gas supply unit to purge the DIW adhering to the substrate processing unit 30 and the drainage unit 50.

[0171] This makes it possible to reduce the amount of DIW adhering to the substrate processing section 30 and the drainage section 50 before the return operation S4. Therefore, according to the embodiment, the time required for the return operation S4 can be shortened, and the processing unit 16 can be quickly returned to the liquid processing.

[0172] In the gas purge operation S5, the control unit 18 may supply gas to the area where the DIW is retained. In particular, in the movable parts in the processing unit 16 (for example, the first and second liquid receiving parts 55a, 55b, the first and second support members 56a, 57a, etc.), the DIW may get into narrow gaps and may be difficult to replace even when co-washed, so the gas purge operation S5 may be performed near these movable parts.

[0173] This can further reduce the amount of DIW adhering to the substrate processing unit 30 and the drainage unit 50 before the return operation S4.

[0174] 9 is a diagram for explaining a process flow in the substrate processing system 1 according to Modification 2 of the embodiment. In the cleaning recipe S2 according to Modification 2, during a return operation S4, the concentration of hydrofluoric acid in the waste liquid flowing through the waste liquid passages 59a to 59c (see FIG. 3) is detected by the concentration sensors 62a to 62c (see FIG. 3).

[0175] Then, the control unit 18 performs a determination operation S6 for determining whether or not the concentration of hydrofluoric acid in the drainage liquid flowing through the drainage paths 59a to 59c is appropriate.

[0176] Here, if the DIW in the substrate processing unit 30 and the drainage unit 50 is replaced with BHF for the next process by the return operation S4 and the concentration of hydrofluoric acid in the drainage is appropriate, the control unit 18 ends the return operation S4 and starts the next processing recipe S1b.

[0177] At this time, the control unit 18 controls the switching valves 63a to 63c (see FIG. 3) to switch the discharge paths of the waste liquid flowing through the drainage paths 59a to 59c to the recovery paths 64a to 64c (see FIG. 3). This makes it possible to execute the process recipe S1b while recovering the BHF for the next process.

[0178] On the other hand, if the DIW in the substrate processing unit 30 and the drainage unit 50 has not been sufficiently replaced and the concentration of hydrofluoric acid in the drainage is not appropriate, the control unit 18 continues the return operation S4.

[0179] At this time, the control unit 18 controls the switching valves 63a to 63c to maintain the discharge path of the waste liquid flowing through the drainage paths 59a to 59c at the drain unit DR. This makes it possible to further suppress the recovery of BHF mixed with DIW.

[0180] That is, in the second modification shown in FIG. 9, recovery of BHF mixed with DIW can be further suppressed by performing the return operation S4 while detecting the hydrofluoric acid concentration in the drainage liquid flowing through the drainage paths 59a to 59c using the concentration sensors 62a to 62c.

[0181] This modification 2 is preferably applied, for example, when the BHF having a high hydrofluoric acid concentration is the BHF for the next process among BHFs having various hydrofluoric acid concentrations. In the BHF having such a high hydrofluoric acid concentration, even if a small amount of DIW is mixed, the etching rate changes significantly. That is, the BHF having a high hydrofluoric acid concentration has a higher sensitivity to DIW than the BHF having a low hydrofluoric acid concentration.

[0182] In this way, by applying the above-mentioned judgment operation S6 to BHF, which is highly sensitive to DIW, it is possible to prevent DIW from mixing with the BHF recovery liquid, thereby making it possible to stably carry out liquid processing using the recovery liquid.

[0183] Furthermore, when the BHF having a high concentration of hydrofluoric acid is the BHF to be subjected to the next process, it is preferable to apply the gas purge operation S5 of the modification 1 in addition to the determination operation S6 of the modification 2. This makes it possible to reduce the amount of DIW itself that may be mixed into the BHF by the gas purge operation S5, and therefore to perform the liquid processing using the recovery liquid more stably.

[0184] The substrate processing apparatus (substrate processing system 1) according to the embodiment includes a substrate processing section 30, a drainage section 50, and a control section 18. The substrate processing section 30 performs liquid processing by supplying a processing liquid from a processing liquid supply section to a placed substrate (wafer W). The drainage section 50 has recovery paths 64a-64c connected to storage sections 70a-70c for storing the processing liquid, and drains the processing liquid used in the liquid processing. The control section 18 executes a processing recipe S1 for the liquid processing and a cleaning recipe S2 for cleaning the substrate processing section 30 and the drainage section 50. In addition, the control section 18 executes, as the cleaning recipe S2, a cleaning operation S3 for cleaning the substrate processing section 30 and the drainage section 50 by supplying a cleaning liquid from the cleaning liquid supply section, and then executes a return operation S4 for supplying a processing liquid from the processing liquid supply section and replacing the cleaning liquid adhering to the substrate processing section 30 and the drainage section 50 with the processing liquid. This makes it possible to suppress deterioration of the performance of the liquid processing.

[0185] In the substrate processing apparatus (substrate processing system 1) according to the embodiment, the processing recipe S1 includes a processing sequence of the substrates (wafers W) and the types of processing liquids, so that liquid processing optimized for different types of processing liquids can be performed in the processing unit 16.

[0186] In the substrate processing apparatus (substrate processing system 1) according to the embodiment, the cleaning recipe S2 is selected based on the type of processing liquid included in the processing recipe S1, thereby making it possible to stably perform the liquid processing in the next step.

[0187] In the substrate processing apparatus (substrate processing system 1) according to the embodiment, the cleaning recipe S2 is selected based on the process recipe S1b of the next process of the cleaning recipe S2, so that the liquid processing of the next process can be stably performed.

[0188] In the substrate processing apparatus (substrate processing system 1) according to the embodiment, the waste liquid unit 50 includes a drain unit DR that discharges the processing liquid to the outside. The control unit 18 discharges the waste liquid flowing through the drain paths 59a to 59c from the drain unit DR to the outside while the cleaning recipe S2 is being executed. This makes it possible to prevent the BHF mixed with DIW from being collected.

[0189] In the substrate processing apparatus (substrate processing system 1) according to the embodiment, the drainage unit 50 has concentration sensors 62a-62c for detecting the concentration of the processing liquid. The control unit 18 ends the return operation S4 based on the concentration of the processing liquid detected by the concentration sensors 62a-62c. This can further prevent the BHF mixed with DIW from being collected.

[0190] Moreover, the substrate processing apparatus (substrate processing system 1) according to the embodiment includes a gas supply unit that supplies gas to the substrate processing unit 30 and the drainage unit. After performing the cleaning operation S3, the control unit 18 performs a gas purge operation S5 in which a gas is supplied to purge the cleaning liquid adhering to the substrate processing unit 30 and the drainage unit 50. This allows the processing unit 16 to quickly return to liquid processing.

[0191] In the substrate processing apparatus (substrate processing system 1) according to the embodiment, the control unit 18 supplies gas to a portion where the cleaning liquid accumulates as a gas purge operation S5. This can further reduce the amount of cleaning liquid adhering to the substrate processing unit 30 and the drainage unit 50 before the return operation S4.

[0192] Moreover, the substrate processing apparatus (substrate processing system 1) according to the embodiment includes standby units 65a-65c where the processing liquid supply units are on standby, and the drainage paths of the standby units 65a-65c are connected to the drainage paths 59a-59c of the drainage unit 50. The control unit 18 executes the same cleaning recipe S2 as that of the substrate processing unit 30 for the standby units 65a-65c. This makes it possible to prevent BHF mixed with DIW adhering to the standby units 65a-65c from being collected.

[0193] Moreover, the substrate processing apparatus (substrate processing system 1) according to the embodiment includes a back surface supply unit (back surface nozzle 47) that discharges a processing liquid onto the back surface side of the substrate (wafer W). The controller 18 executes the cleaning recipe S2 for the back surface supply unit (back surface nozzle 47). This makes it possible to prevent the BHF mixed with DIW adhering to the back surface nozzle 47 from being collected.

[0194] <Substrate processing procedure> Next, a procedure of the substrate processing according to the embodiment will be described with reference to Fig. 10. Fig. 10 is a flow chart showing the procedure of the substrate processing executed by the substrate processing system 1 according to the embodiment.

[0195] First, the control unit 18 performs a cleaning recipe selection process to select a cleaning recipe S2 based on a process recipe S1b to be executed next (step S101). For example, the control unit 18 selects a cleaning recipe S2 that includes the same type of BHF as the BHF of the next process included in the process recipe S1b to be executed next.

[0196] Here, if the selected cleaning recipe S2 is recipe A (step S102, recipe A), the control unit 18 performs the cleaning process based on the selected recipe A (step S103). The recipe A is, for example, the cleaning recipe S2 when the BHF in the next process is the first BHF.

[0197] Moreover, this step S103 is a process in which DIW, which is a cleaning liquid, is supplied from a cleaning liquid supply unit (for example, nozzle 41d) and the substrate processing unit 30 and the drainage unit 50 are cleaned with this DIW. By this step S103, crystals resulting from BHF adhering to the substrate processing unit 30 and the drainage unit 50 can be removed.

[0198] Next, the control unit 18 performs a return process in which BHF for the next process is supplied from the processing liquid supply unit based on the selected recipe A, and the DIW adhering to the substrate processing unit 30 and the drainage unit 50 is replaced with BHF (step S104). This makes it possible to prevent the DIW remaining in the substrate processing unit 30 and the drainage unit 50 from being collected in the storage units 70a to 70c.

[0199] Then, the process of step S104 is carried out for a period of time that is previously determined in recipe A, and when this process ends, the control unit 18 ends the series of processes.

[0200] On the other hand, when the cleaning recipe S2 selected in step S101 is recipe B (step S102, recipe B), the control unit 18 performs the cleaning process based on the selected recipe B (step S105). Such recipe B is, for example, the cleaning recipe S2 when the BHF in the next process is the second BHF.

[0201] Moreover, this step S105 is a process in which DIW, which is a cleaning liquid, is supplied from a cleaning liquid supply unit (for example, nozzle 41d) and the substrate processing unit 30 and the drainage unit 50 are cleaned with this DIW. By this step S105, crystals resulting from BHF adhering to the substrate processing unit 30 and the drainage unit 50 can be removed.

[0202] Next, the control unit 18 supplies gas from the gas supply unit provided in the processing unit 16 based on the selected recipe B, and performs a gas purge process to purge the DIW adhering to the substrate processing unit 30 and the drainage unit 50 (step S106). This makes it possible to reduce the amount of DIW adhering to the substrate processing unit 30 and the drainage unit 50 before the next restoration process.

[0203] Next, the control unit 18 performs a return process in which BHF for the next process is supplied from the processing liquid supply unit based on the selected recipe B, and the DIW adhering to the substrate processing unit 30 and the drainage unit 50 is replaced with BHF (step S107). This makes it possible to prevent the DIW remaining in the substrate processing unit 30 and the drainage unit 50 from being collected in the storage units 70a to 70c.

[0204] Then, the process of step S107 is carried out for a period of time that is previously determined in recipe B, and when this process ends, the control unit 18 ends the series of processes.

[0205] Furthermore, when the cleaning recipe S2 selected in step S101 is recipe C (step S102, recipe C), the control unit 18 performs the cleaning process based on the selected recipe C (step S108). The recipe C is, for example, the cleaning recipe S2 when the BHF in the next process is the third BHF.

[0206] Moreover, this step S108 is a process in which DIW, which is a cleaning liquid, is supplied from a cleaning liquid supply unit (for example, nozzle 41d) and the substrate processing unit 30 and the drainage unit 50 are cleaned with this DIW. By this step S108, crystals resulting from BHF adhering to the substrate processing unit 30 and the drainage unit 50 can be removed.

[0207] Next, the control unit 18 supplies gas from the gas supply unit provided in the processing unit 16 based on the selected recipe C, and performs a gas purge process to purge the DIW adhering to the substrate processing unit 30 and the drainage unit 50 (step S109). This makes it possible to reduce the amount of DIW adhering to the substrate processing unit 30 and the drainage unit 50 before the next restoration process.

[0208] Next, the control unit 18 performs a return process in which BHF for the next process is supplied from the processing liquid supply unit based on the selected recipe C, and the DIW adhering to the substrate processing unit 30 and the drainage unit 50 is replaced with BHF (step S110). This makes it possible to prevent the DIW remaining in the substrate processing unit 30 and the drainage unit 50 from being collected in the storage units 70a to 70c.

[0209] Next, the control unit 18 determines whether or not the concentration of hydrofluoric acid in the drainage liquid flowing through the drainage paths 59a to 59c is appropriate (step S111).

[0210] If the concentration of hydrofluoric acid in the drainage liquid is appropriate (step S111, Yes), the control unit 18 ends the series of processes. On the other hand, if the concentration of hydrofluoric acid in the drainage liquid is not appropriate (step S111, No), the control unit 18 continues the process of step S110.

[0211] As described above, in the substrate processing method according to the embodiment, by selecting a cleaning recipe S2 (recipes A to C) according to the processing recipe S1b, it is possible to perform an optimal cleaning process according to the type of BHF used in the processing recipe S1b.

[0212] The substrate processing method according to the embodiment includes a liquid processing step and a cleaning step. In the liquid processing step, a processing recipe S1 is executed to supply a processing liquid from a processing liquid supply unit (nozzles 41a to 41c) to a substrate (wafer W) placed on the substrate processing unit 30, and to recover the used processing liquid from the drainage unit 50 to the storage units 70a to 70c. In the cleaning step, a cleaning recipe S2 is executed to clean the processing liquid adhering to the substrate processing unit 30 and the drainage unit 50 during the liquid processing step. The cleaning step includes a cleaning operation S3 to supply a cleaning liquid to clean the substrate processing unit 30 and the drainage unit, and a return operation S4 to supply a processing liquid to replace the cleaning liquid adhering to the substrate processing unit 30 and the drainage unit 50 with the processing liquid. This makes it possible to suppress deterioration of the performance of the liquid processing.

[0213] Although the embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present disclosure. For example, in the above embodiment, the cleaning liquid is DIW, and the processing liquid is BHF, but the cleaning liquid and the processing liquid according to the embodiment are not limited to this example.

[0214] The disclosed embodiments should be considered to be illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0215] W wafer (example of substrate) 1. Substrate processing system (an example of a substrate processing apparatus) 16 Processing Unit 18 Control Unit 30 Substrate processing section 41a to 41c: nozzles (an example of a processing liquid supply unit) 50 Drain 59a~59c Drainage channel 62a~62c Concentration sensor 64a~64c Collection route 65a~65c Standby section 70a~70c Storage section S1, S1a, S1b Processing Recipes S2 Cleaning Recipe S3 Cleaning operation S4 Recovery Action S5 Gas purge operation

Claims

1. a substrate processing section for supplying a processing liquid from a processing liquid supply section to a placed substrate to perform liquid processing; a drainage section having a recovery path connected to a storage section that stores the treatment liquid and that drains the treatment liquid used in the liquid treatment; a control unit that executes a process recipe for the liquid processing and a cleaning recipe for cleaning the substrate processing unit and the liquid discharge unit; Equipped with The drainage section is a mist guard having a cylindrical first outer circumferential cylinder portion and a first protruding portion extending from an upper end portion of the first outer circumferential cylinder portion toward an inside of the first outer circumferential cylinder portion; a cup having a cylindrical second outer peripheral cylinder portion and a second protruding portion extending from an upper end portion of the second outer peripheral cylinder portion toward an inside of the second outer peripheral cylinder portion, with at least a portion of the second protruding portion being located below the first protruding portion of the mist guard; a nozzle located on an upper surface of the second protruding portion of the cup and supplying liquid toward a lower surface of the first protruding portion of the mist guard, The control unit executes, as the cleaning recipe, a cleaning operation of supplying a cleaning liquid from the nozzle to clean the underside of the first overhanging portion of the mist guard, and storing the cleaning liquid in a space between the first overhanging portion and the first outer peripheral cylinder portion and the second overhanging portion, and then executes a discharge operation of discharging the cleaning liquid stored in the space from the space, and then executes a return operation of supplying a processing liquid used in a next processing recipe of the cleaning recipe from the nozzle to replace the cleaning liquid attached to the underside of the first overhanging portion of the mist guard with the processing liquid. Substrate processing equipment.

2. In the returning operation, the control unit stores the treatment liquid in a space between the first protruding portion and the first outer peripheral cylinder portion of the mist guard and the second protruding portion of the cup, and further discharges the treatment liquid stored in the space from the space. The substrate processing apparatus according to claim 1 .

3. a liquid processing step of executing a processing recipe in which a processing liquid is supplied from a processing liquid supply unit to a substrate placed in a substrate processing unit and the used processing liquid is collected from a drainage unit to a storage unit; a cleaning process that executes a cleaning recipe for cleaning the processing liquid adhered to the substrate processing section and the liquid discharge section during the liquid processing process; Including, The drainage section is a mist guard having a cylindrical first outer circumferential cylinder portion and a first protruding portion extending from an upper end portion of the first outer circumferential cylinder portion toward an inside of the first outer circumferential cylinder portion; a cup having a cylindrical second outer peripheral cylinder portion and a second protruding portion extending from an upper end portion of the second outer peripheral cylinder portion toward an inside of the second outer peripheral cylinder portion, with at least a portion of the second protruding portion being located below the first protruding portion of the mist guard; a nozzle located on an upper surface of the second protruding portion of the cup and supplying liquid toward a lower surface of the first protruding portion of the mist guard, The washing step comprises: a cleaning operation for supplying a cleaning liquid from the nozzle to clean the underside of the first overhanging portion of the mist guard and storing the cleaning liquid in a space between the first overhanging portion and the first outer peripheral cylinder portion and the second overhanging portion, a discharge operation for discharging the cleaning liquid stored in the space from the space, and a return operation for supplying a processing liquid used in a next processing recipe of the cleaning recipe from the nozzle to replace the cleaning liquid adhering to the underside of the first overhanging portion of the mist guard with the processing liquid. A method for processing a substrate.

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