JP7585124B2 - Treatment liquid flow method and treatment liquid supply device - Google Patents

Description

The present invention relates to a treatment liquid distribution method and a treatment liquid supply device.

The liquid processing device described in Patent Document 1 includes a tank, a circulation line, a pump, a filter, a back pressure valve, and a control unit. The tank stores the processing liquid. The circulation line returns the processing liquid sent from the tank to the tank. The pump forms a circulating flow of the processing liquid in the circulation line. The filter is provided downstream of the pump in the circulation line. The back pressure valve is provided downstream of the filter in the circulation line. The control unit controls the pump and the back pressure valve. When starting to circulate the processing liquid in the circulation line, the control unit controls the pump discharge pressure so that the pump discharge pressure rises to a first pressure and increases to a second pressure greater than the first pressure after a predetermined time has elapsed.

By controlling the pump discharge pressure to be the first pressure and starting circulation of the treatment liquid, the pressure difference between the upstream and downstream sides of the filter can be kept small. As a result, it is possible to prevent foreign matter (particles) from passing through the filter due to the pump discharge pressure immediately after starting circulation of the treatment liquid.

JP 2019-41039 A

The inventors of this application have conducted extensive research into a technology for reducing particles contained in a processing liquid using a method different from that of the liquid processing apparatus described in Patent Document 1.

The object of the present invention is to provide a processing liquid distribution method and processing liquid supply device that can effectively reduce particles contained in the processing liquid.

According to one aspect of the present invention, in a processing liquid distribution method, the processing liquid is distributed to a nozzle that discharges the processing liquid onto a substrate. The processing liquid distribution method includes a monitoring step, a driving step, and a distribution step. In the monitoring step, a first pressure indicating a pressure on a primary side of a filter disposed in a first pipe and capturing particles contained in the processing liquid, and a second pressure indicating a pressure on a secondary side of the filter are monitored. In the driving step, a pump disposed upstream of the filter and sending the processing liquid to the first pipe is driven. In the distribution step, while the pump is driven, the flow path of the first pipe, which is in a closed state, is opened at a position downstream of the filter, thereby distributing the processing liquid through the first pipe. The distribution step includes a differential pressure adjustment step. In the differential pressure adjustment step, based on the monitoring results of the first pressure and the second pressure, the differential pressure between the first pressure and the second pressure after the flow path of the first pipe is opened is made smaller than the differential pressure between the first pressure and the second pressure before the flow path of the first pipe is opened.

In one aspect of the present invention, it is preferable that one end and the other end of the first pipe are connected to a treatment liquid tank that stores the treatment liquid. In the circulation process, it is preferable that the treatment liquid circulates through the first pipe. In the differential pressure adjustment process, it is preferable that the pressure on the secondary side of the filter is adjusted based on the monitoring results of the first pressure and the second pressure, so that the differential pressure after the flow path of the first pipe is opened is made smaller than the differential pressure before the flow path of the first pipe is opened.

In one aspect of the present invention, it is preferable that the treatment liquid circulation method further includes a circulation step of circulating the treatment liquid in the second pipe by opening a flow path of the second pipe extending from the first pipe to the treatment liquid tank after the driving step and before the circulation step.

In one aspect of the present invention, it is preferable that the method further includes a first drainage step of discharging the treated liquid into a first drainage pipe extending from the filter after the circulation step and before the flow step.

In one aspect of the present invention, in the circulation process, it is preferable to set the target output value set for the pump to a value greater than the target output value set for the pump when circulating the treatment liquid in the second pipe.

In one aspect of the present invention, the flow process preferably includes a second drainage process in which the treated liquid is discharged into a second drainage pipe extending from the first pipe.

In one aspect of the present invention, in the differential pressure adjustment process, it is preferable to adjust the differential pressure after the flow path of the first pipe is opened so that the differential pressure falls within a predetermined range.

According to another aspect of the present invention, a processing liquid supplying device supplies the processing liquid to a nozzle that ejects the processing liquid onto a substrate. The processing liquid supplying device includes a first pipe, a filter, a first pressure detection unit, a second pressure detection unit, a pump, a flow rate adjustment mechanism, and a control unit. The processing liquid flows through the first pipe. The filter is disposed in the first pipe and captures particles contained in the processing liquid. The first pressure detection unit detects a first pressure indicating a pressure on the primary side of the filter. The second pressure detection unit detects a second pressure indicating a pressure on the secondary side of the filter. The pump is disposed upstream of the filter and sends the processing liquid to the first pipe. The flow rate adjustment mechanism is disposed in the first pipe downstream of the filter and adjusts the flow rate of the processing liquid flowing through the first pipe. The control unit controls the flow rate adjustment mechanism. The control unit drives the pump in a stopped state. The control unit controls the flow rate adjustment mechanism to open the flow path of the first pipe that is closed when the pump is driven. The control unit controls the flow rate adjustment mechanism based on the monitoring results of the first pressure and the second pressure so that the differential pressure between the first pressure and the second pressure after the flow path of the first piping is opened is smaller than the differential pressure between the first pressure and the second pressure before the flow path of the first piping is opened.

The processing liquid distribution method and processing liquid supply device according to the present invention can effectively reduce particles contained in the processing liquid.

1 is a plan view showing an inside of a substrate processing apparatus according to a first embodiment of the present invention. 2 is a side view showing the inside of the processing unit according to the first embodiment. FIG. 1 is a diagram showing a configuration of a treatment liquid supplying device according to a first embodiment; 3 is a flowchart showing a substrate processing method according to the first embodiment. 5 is a flowchart showing an internal circulation preparation operation of the treatment liquid supplying apparatus according to the first embodiment. 6A to 6C are diagrams illustrating an internal circulation preparation operation of the treatment liquid supplying apparatus according to the first embodiment. 5A to 5C are diagrams illustrating an internal circulation operation of the treatment liquid supplying device according to the first embodiment. 6A to 6C are diagrams illustrating a filter drainage operation of the treatment liquid supplying device according to the first embodiment. 5 is a flowchart showing an external circulation operation of the treatment liquid supplying device according to the first embodiment. 5A to 5C are diagrams illustrating an external circulation operation of the treatment liquid supplying device according to the first embodiment. 5A to 5C are diagrams illustrating a processing liquid supplying operation of the processing liquid supplying device according to the first embodiment. 5 is a graph showing an example of a state of a pump, a first pressure, a second pressure, and a differential pressure according to the first embodiment. 10 is a flowchart showing an external circulation operation of the treatment liquid supplying device according to the second embodiment of the present invention. 13A and 13B are diagrams illustrating an external circulation drainage operation of the treatment liquid supplying device according to the second embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference symbols and the description will not be repeated. For ease of explanation, a three-dimensional orthogonal coordinate system (X, Y, Z) is appropriately depicted in the drawings. In the drawings, the X-axis and Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction.

(Embodiment 1)
First, a substrate processing apparatus 100 will be described with reference to Fig. 1. Fig. 1 is a plan view showing the inside of the substrate processing apparatus 100. The substrate processing apparatus 100 shown in Fig. 1 processes a substrate W with a processing liquid.

The substrate W is, for example, a semiconductor wafer, a substrate for a liquid crystal display device, a substrate for a plasma display, a substrate for a field emission display (FED), a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, a substrate for a photomask, a ceramic substrate, or a substrate for a solar cell.

The processing liquid is, for example, a chemical liquid, such as dilute hydrofluoric acid (DHF), hydrofluoric acid (HF), hydronitric acid (a mixture of hydrofluoric acid and nitric acid (HNO ₃ )), buffered hydrofluoric acid (BHF), ammonium fluoride, HFEG (a mixture of hydrofluoric acid and ethylene glycol), phosphoric acid (H ₃ PO ₄ ), sulfuric acid, acetic acid, nitric acid, hydrochloric acid, ammonia water, hydrogen peroxide water, organic acid (e.g., citric acid, oxalic acid), organic alkali (e.g., TMAH: tetramethylammonium hydroxide), sulfuric acid hydrogen peroxide water mixture (SPM), ammonia hydrogen peroxide water mixture (SC1), hydrochloric acid hydrogen peroxide water mixture (SC2), isopropyl alcohol (IPA), a surfactant, or a corrosion inhibitor.

As shown in FIG. 1, the substrate processing apparatus 100 includes multiple load ports LP, an indexer robot IR, a center robot CR, multiple processing units 1, a control device 2, multiple fluid boxes 3, and a processing liquid cabinet 4.

Each load port LP accommodates multiple stacked substrates W. The indexer robot IR transports substrates W between the load port LP and the center robot CR. The center robot CR transports substrates W between the indexer robot IR and the processing units 1. Each processing unit 1 supplies a processing liquid to the substrate W to process the substrate W. Each fluid box 3 accommodates fluidic equipment. The processing liquid cabinet 4 accommodates a processing liquid.

Specifically, the multiple processing units 1 form multiple towers TW (four towers TW in the example of FIG. 1) arranged to surround the center robot CR in a plan view. Each tower TW includes multiple processing units 1 (three processing units 1 in the example of FIG. 1) stacked vertically. The multiple fluid boxes 3 correspond to the multiple towers TW, respectively. The processing liquid in the processing liquid cabinet 4 is supplied to all processing units 1 included in the tower TW corresponding to the fluid box 3 via one of the fluid boxes 3.

The control device 2 controls the load port LP, the indexer robot IR, the center robot CR, the processing unit 1, the fluid box 3, and the processing liquid cabinet 4. The control device 2 is, for example, a computer.

The control device 2 includes a control unit 21 and a memory unit 22. The control unit 21 includes a processor such as a CPU (Central Processing Unit). The memory unit 22 includes a storage device and stores data and computer programs. Specifically, the memory unit 22 includes a main storage device such as a semiconductor memory, and an auxiliary storage device such as a semiconductor memory, a solid state drive, and/or a hard disk drive. The memory unit 22 may include removable media. The memory unit 22 corresponds to an example of a non-transitory computer-readable storage medium.

Next, the processing unit 1 will be described with reference to Figure 2. Figure 2 is a side view showing the inside of the processing unit 1.

As shown in FIG. 2, the processing unit 1 includes a chamber 11, a spin chuck 12, a spin motor 13, a nozzle 14, a nozzle moving unit 15, multiple guards 16, a waiting pod 17, and a nozzle 18. The substrate processing apparatus 100 further includes a processing liquid supply device 200, a drainage pipe 7, a valve 8, a valve 19, and a pipe 20. The processing liquid supply device 200 includes a valve 5 and a pipe 6. The drainage pipe 7 and the valve 8 can also be considered as components of the processing liquid supply device 200.

The chamber 11 has a generally box-like shape. The chamber 11 houses a spin chuck 12, a spin motor 13, a nozzle 14, a nozzle moving section 15, multiple guards 16, a waiting pod 17, a nozzle 18, a portion of the piping 6, a portion of the drainage piping 7, and a portion of the piping 20. For example, the valves 5, 8, and 19 may also be housed in the chamber 11.

The spin chuck 12 holds the substrate W. Specifically, the spin motor 13 rotates the spin chuck 12 around the rotation axis AX1. Thus, the spin chuck 12 rotates the substrate W around the rotation axis AX1 while holding the substrate W horizontally. Specifically, the spin chuck 12 includes a spin base 121 and multiple chuck members 122. The spin base 121 is substantially disk-shaped and supports the multiple chuck members 122 in a horizontal position. The multiple chuck members 122 hold the substrate W in a horizontal position.

The nozzle 14 ejects the processing liquid onto the substrate W. The nozzle movement unit 15 raises and lowers the nozzle 14 and rotates the nozzle 14 horizontally around the rotation axis AX2. To raise and lower the nozzle 14, the nozzle movement unit 15 includes, for example, a ball screw mechanism and an electric motor that provides driving force to the ball screw mechanism. The nozzle movement unit 15 also includes, for example, an electric motor to rotate the nozzle 14 horizontally.

The processing liquid supplying device 200 supplies the processing liquid to the nozzle 14. Specifically, the piping 6 of the processing liquid supplying device 200 supplies the processing liquid to the nozzle 14. Thus, the processing liquid flows through the piping 6. The valve 5 is disposed in the piping 6. The valve 5 opens and closes the flow path of the piping 6, switching between supplying and stopping the processing liquid to the nozzle 14.

The waiting pod 17 is disposed below the waiting position of the nozzle 14. The waiting position indicates a position outside the spin chuck 12 with respect to the rotation axis AX1. The waiting pod 17 receives the processing liquid discharged by the nozzle 14 positioned at the waiting position. The nozzle moving unit 15 rotates the nozzle 14 horizontally between the waiting position and the processing position. The processing position of the nozzle 14 indicates a position above the substrate W. The nozzle 14 performs a pre-dispense process at the waiting position before discharging the processing liquid onto the substrate W. The pre-dispense process is a process in which the processing liquid is discharged toward the waiting pod 17 before discharging the processing liquid onto the substrate W. Meanwhile, the nozzle 14 discharges the processing liquid toward the substrate W at the processing position.

A drainage pipe 7 is connected to the waiting pod 17. In the pre-dispense process, the processing liquid received by the waiting pod 17 is discharged through the drainage pipe 7. The drainage pipe 7 is connected to, for example, a drainage tank. A valve 8 is disposed on the drainage pipe 7. The valve 8 opens and closes the flow path of the drainage pipe 7, switching between discharging the processing liquid through the drainage pipe 7 and stopping the discharge.

The nozzle 18 supplies the rinsing liquid toward the substrate W. As a result, the processing liquid is washed away from the substrate W. The rinsing liquid is, for example, deionized water, carbonated water, electrolytic ionized water, hydrogen water, ozone water, or hydrochloric acid water with a diluted concentration (for example, about 10 ppm to 100 ppm).

The pipe 20 supplies the rinse liquid to the nozzle 18. Thus, the rinse liquid flows through the pipe 20. The valve 19 is disposed in the pipe 20. The valve 19 opens and closes the flow path of the pipe 20, switching between supplying and stopping the rinse liquid to the nozzle 18.

Each guard 16 has a generally cylindrical shape. Each guard 16 receives the processing liquid or rinsing liquid discharged from the substrate W.

Next, the details of the processing liquid supplying device 200 will be described with reference to FIG. 3. FIG. 3 is a diagram showing the processing liquid supplying device 200. As shown in FIG. 3, the processing liquid supplying device 200 further includes a processing liquid tank 30, heaters 31 and 32, a temperature sensor 33, a pump 34, a pulse damper 35, a first pressure gauge P1, a filter 37, a second pressure gauge P2, temperature sensors 39 and 40, a third pressure gauge 41, a temperature sensor 42, valves 44, 45, 46, 47, 48, and 49, a flow rate adjustment mechanism 50, an external circulation pipe 60, an internal circulation pipe 61, a drainage pipe 62, a pipe 63, a drainage pipe 64, and pipes 65 and 66. The flow rate adjustment mechanism 50 includes a valve 38 and a valve 43. In addition, the processing liquid supplying device 200 includes a plurality of pipes 6 and a plurality of valves 5 corresponding to a plurality of processing units 1.

The control unit 21 controls the treatment liquid supply device 200. Specifically, the heaters 31, 32, the pump 34, the valves 5, 8, 44, 45, 46, 47, 48, 49, and the flow rate adjustment mechanism 50 are controlled by the control unit 21. In addition, the temperature sensors 33, 39, 40, 42 detect the temperature of the treatment liquid and output detection values indicating the detected temperatures to the control unit 21. In addition, the first pressure gauge P1, the second pressure gauge P2, and the third pressure gauge 41 detect the pressure of the treatment liquid and output detection values indicating the detected pressures to the control unit 21.

Furthermore, for example, the processing liquid tank 30, heaters 31, 32, temperature sensor 33, pump 34, pulse damper 35, first pressure gauge P1, filter 37, second pressure gauge P2, valve 38, temperature sensor 39, valves 44, 45, 46, 47, 48, 49, part of the external circulation piping 60, the internal circulation piping 61, part of the drainage piping 62, piping 63, part of the drainage piping 64, piping 65, and part of the piping 66 are housed in the processing liquid cabinet 4 (Figure 1).

On the other hand, for example, a part of the external circulation piping 60, the temperature sensor 40, the third pressure gauge 41, the temperature sensor 42, the valve 43, the valve 5, and a part of the piping 6 are housed in the fluid box 3 (Figure 1).

The processing liquid tank 30 stores the processing liquid. The pipe 66 replenishes new processing liquid to the processing liquid tank 30. The valve 49 is disposed in the pipe 66 and opens and closes the flow path of the pipe 66.

The upstream end 70 and downstream end 71 of the external circulation pipe 60 are connected to the treatment liquid tank 30. The external circulation pipe 60 includes a first circulation pipe 601 and a second circulation pipe 602. One end of the first circulation pipe 601 is connected to the treatment liquid tank 30, and the other end of the first circulation pipe 601 is connected to the filter 37. One end of the first circulation pipe 601 is the upstream end of the external circulation pipe 60. One end of the second circulation pipe 602 is connected to the filter 37, and the other end of the second circulation pipe 602 is connected to the treatment liquid tank 30. The other end of the second circulation pipe 602 is the downstream end of the external circulation pipe 60. Although not shown in the figure for the sake of simplicity, multiple second circulation pipes 602 are provided corresponding to multiple towers TW (FIG. 1). The multiple second circulation pipes 602 branch off on the secondary side of the filter 37.

The external circulation piping 60 corresponds to an example of the "first piping" of the present invention.

The heater 31, heater 32, pump 34, pulse damper 35, first pressure gauge P1, and filter 37 are arranged in this order from upstream to downstream in the external circulation pipe 60 (specifically, the first circulation pipe 601). The filter 37 is also arranged at position 73 in the external circulation pipe 60. Position 73 is downstream of the pump 34 and upstream of the branch position 74 and the flow rate adjustment mechanism 50.

The heaters 31 and 32 heat the processing liquid in the processing liquid tank 30 to adjust the temperature of the processing liquid in the processing liquid tank 30. In the first embodiment, the processing liquid supply device 200 has two heaters 31 and 32 connected in series, but it may have one heater or three or more heaters.

The pump 34 sends the processing liquid in the processing liquid tank 30 to the external circulation pipe 60. Specifically, the pump 34 sends the processing liquid in the processing liquid tank 30 to the first circulation pipe 601. The pump 34 is disposed in the external circulation pipe 60 (specifically, the first circulation pipe 601) upstream of the filter 37 and the branch position 72. The temperature sensor 33 detects the temperature of the processing liquid flowing through the first circulation pipe 601 at a position 80 between the heater 32 and the pump 34. The pulse damper 35 suppresses the pulsation of the processing liquid sent out from the pump 34.

The filter 37 captures particles contained in the processing liquid passing through the filter 37. In other words, the filter 37 removes particles contained in the processing liquid passing through the filter 37. In other words, the filter 37 filters the processing liquid.

For example, the filter 37 has many holes (not shown). The processing liquid passes through the holes of the filter 37. As a result, the processing liquid is filtered by the filter 37. Specifically, when particles contained in the processing liquid pass through the holes of the filter 37, they are adsorbed by the wall surfaces that define the holes and are captured within the holes. As a result, the particles are removed from the processing liquid.

For example, the filter 37 includes a PTFE (polytetrafluoroethylene) hydrophilic membrane as a filtration membrane. The PTFE hydrophilic membrane is a membrane in which the surface of a PTFE substrate is made hydrophilic.

The particle capture ability of filter 37 changes with fluctuations in the pressure applied to filter 37. When pressure is applied to filter 37, it is capable of capturing smaller particles than when no pressure is applied to filter 37. As the pressure applied to filter 37 increases, it is capable of capturing even smaller particles.

The first pressure gauge P1 is disposed on the primary side of the filter 37. The first pressure gauge P1 detects a first pressure that indicates the pressure on the primary side of the filter 37. The first pressure gauge P1 outputs a detection value that indicates the first pressure to the control unit 21. The control unit 21 acquires the detection value that indicates the first pressure and monitors the first pressure in real time. The first pressure gauge P1 is, for example, a pressure sensor.

The first pressure gauge P1 corresponds to an example of the "first pressure detection unit" of the present invention.

The second pressure gauge P2 is disposed on the secondary side of the filter 37. The second pressure gauge P2 detects a second pressure that indicates the pressure on the secondary side of the filter 37. The second pressure gauge P2 outputs a detection value that indicates the second pressure to the control unit 21. The control unit 21 acquires the detection value that indicates the second pressure and monitors the second pressure in real time. The second pressure gauge P2 is, for example, a pressure sensor.

The second pressure gauge P2 corresponds to an example of the "second pressure detection unit" of the present invention.

For ease of explanation, the first pressure may be given the same reference symbol "P1" as the first pressure gauge P1, and the second pressure may be given the same reference symbol as the second pressure gauge P2.

The filter 37 is disposed between the first pressure gauge P1 and the second pressure gauge P2 in the external circulation piping 60. When the pressure difference DF between the first pressure P1 and the second pressure P2 is large, some of the particles captured by the filter 37 may detach from the filter 37 and diffuse into the external circulation piping 60, compared to when the pressure difference DF is small. For example, the pressure difference DF tends to be large when the pump 34 is started up, that is, when the pump 34 is driven from a stopped state.

Specifically, the differential pressure DF is the value obtained by subtracting the second pressure P2 from the first pressure P1 (DF = P1 - P2). In this case, for example, when the differential pressure DF is large, some of the particles captured in the filter 37 may diffuse to the secondary side of the filter 37 compared to when the differential pressure DF is small.

Therefore, in the first embodiment, when the pump 34 is driven in a stopped state, the processing liquid supply device 200 makes the differential pressure DF after the flow path of the external circulation pipe 60 is opened at a position downstream of the filter 37 smaller than the differential pressure DF before the flow path of the external circulation pipe 60 is opened at a position downstream of the filter 37 based on the monitoring results of the first pressure P1 and the second pressure P2. Therefore, it is possible to suppress the particles captured in the filter 37 from diffusing to the secondary side of the filter 37 due to the differential pressure DF. As a result, it is possible to effectively reduce the particles contained in the processing liquid.

The flow rate adjustment mechanism 50 is disposed in the external circulation pipe 60 (specifically, the second circulation pipe 602) downstream of the filter 37. The flow rate adjustment mechanism 50 adjusts the flow rate of the treatment liquid flowing through the external circulation pipe 60. Adjusting the flow rate of the treatment liquid includes not only increasing or decreasing the flow rate, but also setting the flow rate to zero. Thus, the flow rate adjustment mechanism 50 blocks or opens the flow path of the external circulation pipe 60, and increases or decreases the flow rate of the treatment liquid. In other words, the flow rate adjustment mechanism 50 adjusts the pressure of the treatment liquid flowing through the second circulation pipe 602. In further other words, the flow rate adjustment mechanism 50 adjusts the pressure on the secondary side of the filter 37.

Specifically, the valve 38 of the flow rate adjustment mechanism 50 is disposed in the second circulation pipe 602 (external circulation pipe 60) downstream of the filter 37 and the second pressure gauge P2 and upstream of the branch position 74. The valve 38 closes or opens the flow path of the second circulation pipe 602 on the secondary side of the filter 37.

The valve 43 is disposed in the second circulation pipe 602 (external circulation pipe 60) at a position downstream of the filter 37, the second pressure gauge P2, and the branch position 74. The valve 43 adjusts the flow rate of the treatment liquid flowing through the second circulation pipe 602. In other words, the valve 43 adjusts the pressure of the treatment liquid flowing through the second circulation pipe 602. In other words, the valve 43 adjusts the pressure (second pressure P2) on the secondary side of the filter 37. The valve 43 is, for example, a motor needle valve, a back pressure valve, or a relief valve. The control unit 21 can adjust the opening degree of the valve 43 continuously or stepwise. The opening degree indicates the degree to which the valve 43 is open. For example, the smaller the opening degree of the valve 43, the greater the pressure (second pressure P2) on the secondary side of the filter 37. Note that, when the valve 43 can close and open the flow path of the second circulation pipe 602, for example, the flow rate adjustment mechanism 50 does not need to have the valve 38.

The temperature sensor 39 detects the temperature of the treatment liquid flowing through the second circulation pipe 602 (external circulation pipe 60) at a position 81 downstream of the filter 37 and the valve 38. The temperature sensor 40 detects the temperature of the treatment liquid flowing through the second circulation pipe 602 (external circulation pipe 60) at a position 82 downstream of the temperature sensor 39. Position 82 is upstream of the branch position 74.

The third pressure gauge 41 detects the pressure of the treatment liquid flowing through the second circulation pipe 602 (external circulation pipe 60) at position 83 on the primary side of the valve 43. Position 83 is downstream of the branch position 74. The temperature sensor 42 detects the temperature of the treatment liquid flowing through the second circulation pipe 602 (external circulation pipe 60) at position 84 on the primary side of the valve 43. Position 84 is downstream of the branch position 74.

A number of pipes 6 are connected to each of a number of branch positions 74 of the second circulation pipe 602 (external circulation pipe 60). The pipes 6 extend from the branch positions 74 to the nozzle 14. The branch positions 74 are downstream of the filter 37 and upstream of the valve 43.

The internal circulation pipe 61 extends from a branch position 72 of the first circulation pipe 601 (external circulation pipe 60) to the treatment liquid tank 30. The branch position 72 is downstream of the pump 34 and upstream of the filter 37. The valve 44 is disposed in the internal circulation pipe 61. The valve 44 opens and closes the flow path of the internal circulation pipe 61.

The internal circulation piping 61 corresponds to an example of the "second piping" of the present invention.

The drainage pipe 62 extends from the filter 37. The drainage pipe 62 is a pipe for discharging the processing liquid present inside the filter 37 (specifically, the internal primary side). Specifically, one end of the drainage pipe 62 is connected to the internal primary side space of the filter 37, and the other end of the drainage pipe 62 is connected to, for example, a drainage tank. The valve 45 is disposed in the drainage pipe 62. The valve 45 opens and closes the flow path of the drainage pipe 62.

The drainage pipe 62 corresponds to an example of the "first drainage pipe" of the present invention.

The drainage pipe 64 extends from the filter 37. The drainage pipe 64 is a pipe for discharging the processing liquid present inside the filter 37 (specifically, the internal secondary side). Specifically, one end of the drainage pipe 64 is connected to the secondary side space inside the filter 37, and the other end of the drainage pipe 64 is connected to, for example, a drainage tank. The valve 46 is disposed in the drainage pipe 64. The valve 46 opens and closes the flow path of the drainage pipe 64.

The pipe 63 extends from the filter 37 to the processing liquid tank 30. The pipe 63 is a pipe for removing air bubbles inside the filter 37 (specifically, the internal primary side) that cause particle generation. Specifically, one end of the pipe 63 is connected to the internal primary side space of the filter 37, and the other end of the pipe 63 is connected to the processing liquid tank 30. The valve 47 is disposed in the pipe 63. The valve 47 opens and closes the flow path of the pipe 63.

The pipe 65 extends from the filter 37 to the processing liquid tank 30. The pipe 65 is for removing air bubbles inside the filter 37 (specifically, the internal secondary side) that cause particle generation. Specifically, one end of the pipe 65 is connected to the internal secondary side space of the filter 37, and the other end of the pipe 65 is connected to the processing liquid tank 30. The valve 48 is disposed in the pipe 65. The valve 48 opens and closes the flow path of the pipe 65.

Next, the substrate processing method according to the first embodiment will be described with reference to FIGS. 1 to 11. FIG. 4 is a flowchart showing the substrate processing method according to the first embodiment. FIG. 5 is a flowchart showing the internal circulation preparation operation in step S2 of FIG. 4. FIG. 6 is a diagram showing the internal circulation preparation operation of the processing liquid supplying device 200. FIG. 7 is a diagram showing the internal circulation operation of the processing liquid supplying device 200. FIG. 8 is a diagram showing the filter drainage operation of the processing liquid supplying device 200. FIG. 9 is a flowchart showing the external circulation operation of the processing liquid supplying device 200. FIG. 10 is a diagram showing the external circulation operation of the processing liquid supplying device 200. FIG. 11 is a diagram showing the processing liquid supply operation of the processing liquid supplying device 200.

In this specification, in symbols showing valves (e.g., valves 5, 8, 38, 43, 44, 45, 46, 47, 48, 49), white indicates that the valve is closed, and black indicates that the valve is open. In addition, in symbols showing pump 34, a white triangle indicates that pump 34 is stopped, and a black triangle indicates that pump 34 is running. Furthermore, the flow path of the processing liquid is indicated by a thick line.

As shown in FIG. 4, the substrate processing method according to the first embodiment includes steps S1 to S10. The substrate processing method is performed by the substrate processing apparatus 100 under the control of the control unit 21. In particular, steps S1 to S5 constitute a processing liquid circulating method. The processing liquid circulating method is performed by the processing liquid supply apparatus 200 under the control of the control unit 21. In the processing liquid circulating method, the processing liquid supplied to the nozzle 14 that ejects the processing liquid onto the substrate W is circulated. Specifically, in the processing liquid circulating method, the processing liquid supplied to the nozzle 14 that ejects the processing liquid onto the substrate W is circulated.

As shown in Figures 3 and 4, first, in step S1, the control unit 21 starts monitoring the first pressure P1 and the second pressure P2. That is, the control unit 21 starts acquiring a detection value indicating the first pressure P1 from the first pressure gauge P1, and starts acquiring a detection value indicating the second pressure P2 from the second pressure gauge P2. Step S1 corresponds to an example of the "monitoring step" of the present invention.

Next, in step S2, the processing liquid supply device 200 executes an internal circulation preparation operation. The internal circulation preparation operation is executed before the internal circulation operation of step S3, and is an operation for preparing for the internal circulation. The internal circulation refers to circulating the processing liquid in the processing liquid tank 30 through the internal circulation piping 61 while allowing the temperature of the processing liquid to reach a target temperature.

Specifically, as shown in FIG. 5, step S2 (internal circulation preparation operation) includes steps S201 and S202.

5 and 6, in step S201, the control unit 21 drives the pump 34 in a stopped state. In this case, for example, the control unit 21 sets a first target output value TG1 as the target output value of the pump 34. The target output value is a set value set for the pump 34 so that the pump 34 achieves the target discharge pressure. The larger the set target output value, the higher the target discharge pressure. For example, when the pump 34 is a non-positive-displacement pump such as a centrifugal pump or a propeller pump, the target output value is indicated by the rotation speed of a rotor such as an impeller or a propeller. For example, when the pump 34 is a positive-displacement pump such as a reciprocating pump, the target output value is indicated by the stroke length and/or stroke number of a reciprocating element. The reciprocating pump is, for example, a bellows pump. Step S201 corresponds to an example of the "driving step" of the present invention.

Next, as shown in FIG. 5 and FIG. 6, in step S202, the control unit 21 opens valves 38, 44, 47, and 48, and closes valves 5, 8, 43, 45, and 46. Because valve 38 is open, the flow path of the internal circulation pipe 61 is opened. As a result, the treatment liquid flows into the internal circulation pipe 61.

For example, the control unit 21 ends step S202 when the first pressure P1 reaches the target pressure P11. Then, the process returns to the main routine of FIG. 4. The control unit 21 may cause the processing liquid supply device 200 to continue the internal circulation preparation operation of step S2 for a predetermined preparation period. The predetermined preparation period is, for example, determined in advance experimentally and/or empirically.

Next, as shown in FIG. 4 and FIG. 7, in step S3, the processing liquid supplying device 200 circulates the processing liquid internally. Step S3 corresponds to an example of the "circulation step" of the present invention. Step S3 can also be described as an internal circulation step.

Specifically, in step S3, as shown in FIG. 7, the control unit 21 opens valve 44 and closes valves 5, 8, 38, 43, 45, 46, 47, and 48. As a result, the processing liquid stored in the processing liquid tank 30 circulates through the first circulation pipe 601 and the internal circulation pipe 61, and internal circulation is performed. In this case, the control unit 21 controls the heaters 31 and 32 so that the temperature of the processing liquid circulating internally becomes the target temperature while monitoring the temperature of the processing liquid detected by the temperature sensor 33. When the temperature of the processing liquid circulating internally reaches the target temperature, the process proceeds to step S4. Note that the control unit 21 may cause the processing liquid supply device 200 to perform internal circulation of the processing liquid for only a predetermined internal circulation period. The predetermined internal circulation period is, for example, determined in advance experimentally and/or empirically.

That is, in step S3, the control unit 21 circulates the treatment liquid in the internal circulation pipe 61 by opening the flow path of the internal circulation pipe 61 with the valve 44 after step S2 (steps S201 and S202) and before steps S4 and S5. Therefore, in the first embodiment, the temperature of the treatment liquid can reach the target temperature before step S5 (external circulation operation). As a result, the treatment liquid being circulated externally can be quickly supplied to the nozzle 14.

Next, as shown in Figs. 4 and 8, in step S4, the processing liquid supplying device 200 discharges the processing liquid inside the filter 37 to the drainage pipe 62. In the example of Fig. 8, the processing liquid supplying device 200 discharges the processing liquid present in the primary side space inside the filter 37 to the drainage pipe 62. Step S4 corresponds to an example of the "first drainage step" of the present invention.

Specifically, in step S4, as shown in FIG. 8, the control unit 21 opens the valve 45 for only the first drainage period while keeping the valves 5, 8, 38, 43, 44, 46, 47, and 48 closed. Therefore, during the first drainage period, the processing liquid inside the filter 37 is discharged to the drainage pipe 62. As a result, particles in the processing liquid are also discharged from the drainage pipe 62. Note that the first drainage period is, for example, predetermined experimentally and/or empirically.

That is, in step S4, after step S3 and before step S5, the control unit 21 opens the valve 45 to discharge the treatment liquid into the drain pipe 62. Therefore, particles present on the primary side of the filter 37 and particles present inside the filter 37 (internal primary side) can be discharged through the drain pipe 62. As a result, the particles contained in the treatment liquid can be effectively reduced.

For example, in step S4, the control unit 21 may open the valve 46 for a certain period of time at the same time as opening the valve 45, after opening the valve 45, or before opening the valve 45. In this case, particles present inside the filter 37 (internal secondary side) can be discharged through the drain pipe 64. As a result, the particles contained in the treatment liquid can be further effectively reduced.

Next, as shown in FIG. 4 and FIG. 10, in step S5, the treatment liquid supplying device 200 externally circulates the treatment liquid. External circulation refers to circulating the treatment liquid through the external circulation piping 60. Therefore, in step S5, the treatment liquid circulates through the external circulation piping 60. Step S5 corresponds to an example of the "circulation step" of the present invention. Step S5 can be described as an external circulation step.

Specifically, as shown in FIG. 9, step S5 (external circulation operation) includes steps S501 to S503.

First, as shown in FIG. 9 and FIG. 10, in step S501, the control unit 21 changes the target output value of the pump 34 from the first target output value TG1 to the second target output value TG2. The second target output value TG2 is greater than the first target output value TG1. That is, in step S501 (step S5), the control unit 21 sets the target output value to be set for the pump 34 to a value greater than the target output value (first target output value TG1) set for the pump 34 in steps S2 to S4. For example, in step S501 (step S5), the control unit 21 sets the target output value to be set for the pump 34 to a value greater than the target output value (first target output value TG1) set for the pump 34 when circulating the treatment liquid in the internal circulation piping 61.

Next, in step S502, the control unit 21 controls the flow rate adjustment mechanism 50 (valves 38, 43) to open the flow path of the external circulation pipe 60 (specifically, the second circulation pipe 602) in the closed state. Specifically, in a state in which the pump 34 is driven, the control unit 21 controls the flow rate adjustment mechanism 50 to open the flow path of the external circulation pipe 60 in the closed state. Therefore, the flow rate adjustment mechanism 50 circulates the treatment liquid in the external circulation pipe 60 by opening the flow path of the external circulation pipe 60 in the closed state. More specifically, as shown in FIG. 10, the control unit 21 opens the valves 38, 43 and closes the valves 5, 8, 44, 45, 46, 47, 48. As a result, the treatment liquid stored in the treatment liquid tank 30 circulates through the external circulation pipe 60. The external circulation of the treatment liquid continues until the control unit 21 receives an instruction to stop the external circulation.

Next, in step S503, the control unit 21 adjusts the differential pressure DF between the first pressure P1 and the second pressure P2 by using the valve 43 of the flow rate adjustment mechanism 50. Specifically, based on the monitoring results of the first pressure P1 and the second pressure P2 (step S1), the control unit 21 controls the valve 43 of the flow rate adjustment mechanism 50 so that the differential pressure DF between the first pressure P1 and the second pressure P2 after the flow path of the external circulation piping 60 (specifically the second circulation piping 602) is opened is smaller than the differential pressure DF between the first pressure P1 and the second pressure P2 before the flow path of the external circulation piping 60 is opened.

Therefore, the valve 43 adjusts the pressure on the secondary side of the filter 37, i.e., the second pressure P2, based on the monitoring results of the first pressure P1 and the second pressure P2 (step S1), to make the differential pressure DF after the flow path of the external circulation piping 60 is opened smaller than the differential pressure DF before the flow path of the external circulation piping 60 is opened. This makes it possible to suppress the particles captured by the filter 37 from diffusing to the secondary side of the filter 37 due to the differential pressure DF. As a result, the particles contained in the treatment liquid can be effectively reduced. Step S503 corresponds to an example of the "differential pressure adjustment step" of the present invention.

In particular, in embodiment 1, the differential pressure DF is adjusted based on the monitoring results of the first pressure P1 and the second pressure P2 (step S1), so the differential pressure DF can be adjusted more accurately compared to when the first pressure P1 and the second pressure P2 are not monitored (detected).

In addition, in embodiment 1, "after the flow path of the external circulation piping 60 is opened" refers to "after the flow path of the second circulation piping 602 is opened" or "after the flow path of the external circulation piping 60 is opened at a position downstream of the filter 37."

In particular, in the first embodiment, the differential pressure DF when the treatment liquid is circulating externally (i.e., the differential pressure DF when the treatment liquid is circulating through the external circulation piping 60) is made smaller than the differential pressure DF before the flow path of the external circulation piping 60 is opened (the differential pressure DF before the treatment liquid is circulated externally). Therefore, it is possible to prevent particles captured by the filter 37 from diffusing into the external circulation piping 60 due to the differential pressure DF.

More specifically, as an example, the control unit 21 may control the valve 43 of the flow rate adjustment mechanism 50 so that the differential pressure DF after the flow path of the external circulation piping 60 is opened (i.e., the differential pressure DF when the treatment liquid is circulating through the external circulation piping 60) is smaller than the differential pressure DF in step S3 (i.e., the differential pressure DF when the treatment liquid is circulating through the internal circulation piping 61).

For example, in step S503, based on the monitoring results (step S1) of the first pressure P1 and the second pressure P2, the differential pressure DF after the flow path of the external circulation piping 60 is opened (i.e., the differential pressure DF when the treatment liquid is circulating through the external circulation piping 60) may be adjusted so that it falls within a predetermined range RG. Specifically, the control unit 21 may control the valve 43 so that the differential pressure DF after the flow path of the external circulation piping 60 is opened falls within a predetermined range RG.

In this case, the valve 43 adjusts the pressure on the secondary side of the filter 37, i.e., the second pressure P2, to adjust the differential pressure DF after the flow path of the external circulation piping 60 is opened to within a predetermined range RG. The differential pressure DF within the predetermined range RG is smaller than the differential pressure DF before the flow path of the external circulation piping 60 is opened. For example, the differential pressure DF within the predetermined range RG is smaller than the differential pressure DF in step S3. According to the first embodiment, by keeping the differential pressure DF after the flow path of the external circulation piping 60 is opened within the predetermined range RG, it is possible to further suppress the particles captured by the filter 37 from diffusing to the secondary side of the filter 37 due to the differential pressure DF.

The specified range RG preferably includes, for example, zero. Alternatively, the specified range RG is set, for example, as a range of ±K around a reference value, or a range of ±Q% around a reference value. "K" and "Q" are positive real numbers.

Preferably, the control unit 21 causes the valve 43 to adjust the second pressure P2 so that the second pressure P2 on the secondary side of the filter 37 is approximately equal to the first pressure P1 on the primary side of the filter 37. According to this preferred example, the differential pressure DF becomes approximately zero. In other words, the control unit 21 causes the valve 43 to adjust the second pressure P2 so that the differential pressure DF becomes approximately zero. Therefore, it is possible to more effectively prevent particles captured by the filter 37 from diffusing to the secondary side of the filter 37 due to the differential pressure DF. As a result, it is possible to more effectively reduce particles contained in the treatment liquid.

Here, step S503 may be continuously performed during the period when the treatment liquid is performing external circulation, or may be performed for a predetermined adjustment period from the start of step S502 (start of external circulation). The predetermined adjustment period is, for example, determined in advance experimentally and/or empirically. Alternatively, step S503 may be performed, for example, from the start of step S502 (start of external circulation) until the first pressure P1 reaches the target pressure P12 (FIG. 12 described later). Alternatively, for example, step S503 may be performed from the start of step S502 (start of external circulation) until the second pressure P2 reaches the target pressure P20 (FIG. 12 described later). The target pressure P12 and the target pressure P20 are greater than the target pressure P11 (i.e., the first pressure P1 during internal circulation in step S3), which is the target value of the first pressure P1 in step S2 (FIG. 12 described later). In addition, in order to make the differential pressure DF approximately zero, it is preferable that the target pressure P12 and the target pressure P20 are approximately the same.

Next, as shown in FIG. 1, FIG. 2, and FIG. 4, in step S6, the center robot CR loads the substrate W into the processing unit 1. Then, in the processing unit 1, the spin chuck 12 holds the substrate W. Furthermore, the spin motor 13 rotates the spin chuck 12 to rotate the substrate W.

Next, as shown in FIG. 2, FIG. 4, and FIG. 11, in step S7, the processing liquid supplying device 200 supplies the processing liquid from the external circulation pipe 60 to the nozzle 14 via the pipe 6. As a result, the nozzle 14 ejects the processing liquid onto the substrate W. Then, the substrate W is processed by the processing liquid. Note that step S7 may be included in the processing liquid distribution method according to embodiment 1.

Specifically, as shown in FIG. 11, the control unit 21 opens valve 5 for a predetermined processing period while valves 38 and 43 are open and valves 8, 44, 45, 46, 47, and 48 are closed. As a result, during the predetermined processing period, the processing liquid flowing through the external circulation piping 60 is supplied from piping 6 to the nozzle 14. During the predetermined processing period, the nozzle 14 ejects the processing liquid onto the substrate W. When the predetermined processing period has elapsed since the valve 5 was opened, the valve 5 is closed and ejection of the processing liquid from the nozzle 14 is stopped. The predetermined processing period is determined in advance according to the processing purpose of the substrate W.

That is, in step S7, the processing liquid supplying device 200 supplies processing liquid from the external circulation piping 60 to the nozzle 14 while performing external circulation of the processing liquid, that is, while the processing liquid is circulating through the external circulation piping 60. For example, in step S7, the processing liquid supplying device 200 supplies processing liquid from the external circulation piping 60 to the nozzle 14 while continuing to perform the differential pressure adjustment in step S503 or after the differential pressure adjustment in step S503. The processing liquid supplied to the nozzle 14 is then ejected onto the substrate W by the nozzle 14. As a result, the substrate W can be processed with processing liquid with reduced particles.

Next, as shown in FIG. 2 and FIG. 4, in step S8, the nozzle 18 ejects the rinsing liquid onto the substrate W. As a result, the processing liquid on the substrate W is washed away by the rinsing liquid.

Specifically, as shown in FIG. 2, when the valve 19 is opened, the nozzle 18 ejects the rinsing liquid onto the substrate W. When a predetermined rinsing period has elapsed since the valve 19 was opened, the valve 19 is closed and ejection of the rinsing liquid from the nozzle 18 is stopped. Note that the predetermined rinsing period is determined in advance, for example, experimentally and/or empirically.

Next, as shown in Figures 2 and 4, in step S9, the substrate W is dried by rotating the substrate W at high speed.

Specifically, the spin motor 13 accelerates the substrate W in the rotation direction, and rotates the substrate W at a high rotation speed that is higher than the rotation speed of the substrate W in steps S7 and S8. As a result, the liquid is removed from the substrate W, and the substrate W is dried. When a predetermined drying period has elapsed since the high-speed rotation of the substrate W was started, the spin motor 13 stops rotating. Then, the rotation of the substrate W is stopped. Note that the predetermined drying period is determined in advance, for example, experimentally and/or empirically.

Next, as shown in Figures 1, 2, and 4, in step S10, the center robot CR unloads the substrate W from the processing unit 1. In other words, the processed substrate W is unloaded from the chamber 11. Then, the substrate processing method ends.

As described above with reference to Figures 9 and 10, according to the first embodiment, in step S503, the differential pressure DF after the start of external circulation is made smaller than the differential pressure DF before the start of external circulation. As a result, it is possible to effectively suppress the diffusion of particles from the filter 37 due to the differential pressure DF.

In addition, in the second embodiment, in step S501, the target output value set for the pump 34 during external circulation is set to a value greater than the target output value set for the pump 34 during internal circulation. Therefore, a sufficient discharge pressure can be ensured for the nozzle 18 to discharge the processing liquid onto the substrate W in step S7 (FIG. 4).

Next, an example of the state of the pump 34, the first pressure P1, the second pressure P2, and the differential pressure DF will be described with reference to Figures 6 to 8 and Figures 10 to 12. Figure 12 is a graph showing an example of the state of the pump 34, the first pressure P1, the second pressure P2, and the differential pressure DF. Note that Figure 2 is not a strict graph, but is referred to for explaining an outline to facilitate understanding.

As shown in FIG. 12, the horizontal axis of graphs GP1 to GP4 indicates time. The vertical axis of graph GP1 indicates the state of pump 34. The vertical axis of graph GP2 indicates the first pressure P1 on the primary side of filter 37. The vertical axis of graph GP3 indicates the second pressure P2 on the secondary side of filter 37. The vertical axis of graph GP4 indicates the differential pressure DF between the first pressure P1 and the second pressure P2.

As shown in FIG. 6 and graph GP1, at time t1, the pump 34, which is in the off state (stopped state), is driven to start the internal circulation preparation operation (step S2). In this case, the target output value of the pump 34 is set to the first target output value TG1. Also, at time t1, the valve 44 opens the flow path of the internal circulation piping 61. Therefore, as shown in graph GP2, in the period T1 from time t1 to time t2, the first pressure P1 rises. Then, at time t2, the first pressure P1 reaches the target pressure P11. During the period T1, the internal circulation preparation operation (step S2) shown in FIG. 6 is being executed.

On the other hand, as shown in FIG. 6 and graph GP3, in period T1, the valve 43 closes the second circulation pipe 602 of the external circulation pipe 60, so the second pressure P2 is approximately zero. Therefore, as shown in graph GP4, in period T1, the differential pressure DF increases in the same way as the first pressure P1.

Next, as shown in Figures 7 and 12, at time t2, valve 44 leaves the flow path of internal circulation piping 61 open, and valves 38, 47, and 48 are closed, thereby starting the internal circulation operation (step S3). The internal circulation operation is performed during period T2 from time t2 to time t3. Then, as shown in graph GP2, during period T2, the first pressure P1 is generally maintained at the target pressure P11 and is substantially constant.

On the other hand, as shown in FIG. 7 and graph GP3, in period T2, the valve 38 closes the second circulation pipe 602 of the external circulation pipe 60, so the second pressure P2 is approximately zero. Therefore, as shown in graph GP4, in period T2, the differential pressure DF is approximately constant, similar to the first pressure P1.

Next, as shown in Figures 8 and 12, at time t3, the valve 44 closes the flow path of the internal circulation pipe 61, and the valve 45 opens the flow path of the drainage pipe 62, thereby starting the filter drainage operation (step S4). The filter drainage operation is an operation in which the treated liquid is discharged from the filter 37 to the drainage pipe 62. The filter drainage operation is performed during the period T3 from time t3 to time t4. Then, as shown in graph GP3, during the period T3, the first pressure P1 decreases due to the execution of drainage from the filter 37.

On the other hand, as shown in FIG. 8 and graph GP3, in period T3, the valve 38 closes the second circulation pipe 602 of the external circulation pipe 60, so the second pressure P2 is approximately zero. Therefore, as shown in graph GP4, in period T3, the differential pressure DF decreases in conjunction with the decrease in the first pressure P1.

Next, as shown in FIG. 10 and FIG. 12, at time t4, the valve 45 closes the flow path of the drainage pipe 62, and the valves 38 and 43 open the flow path of the second circulation pipe 602 of the external circulation pipe 60, thereby starting the external circulation operation (step S5). The external circulation operation is performed during a period T4 after time t4. In particular, at time t4, the target output value of the pump 34 is set to the second target output value TG2. The second target output value TG2 is greater than the first target output value TG1.

Specifically, the first pressure P1 increases during the period T41 from time t4 to time 5. Then, at time t5, the first pressure P1 reaches the target pressure P12.

On the other hand, as shown in FIG. 10 and graphs GP3 and GP4, in period T41, the valve 43 increases the second pressure P2 to make the differential pressure DF after the start of external circulation smaller than the differential pressure DF before the start of external circulation. In the example of graphs GP3 and GP4, in period T41, the valve 43 increases the second pressure P2 to make the differential pressure DF approximately zero after the start of external circulation. Also, at time t5, the second pressure P2 reaches the target pressure P20. In the example of graphs GP3 and GP4, the target pressure P12 of the first pressure P1 and the target pressure P20 of the second pressure P2 are approximately the same.

Furthermore, as shown in graphs GP3 and GP4, in period T42 from time t5 to time t6, the first pressure P1 is maintained at the target pressure P12, and the second pressure P2 is maintained at the target pressure P20. In period T42, as shown in graph GP4, the differential pressure DF is approximately zero.

Furthermore, as shown in graphs GP3 and GP4, in a period T43 from time t6 to time t7, the control unit 21 changes the opening of the valve 43 to lower the first pressure P1 and the second pressure P2, set the first pressure P1 to the target pressure P13, and set the second pressure P2 to the target pressure P21. For example, at time t6, the opening of the valve 43 is increased to lower the first pressure P1 and the second pressure P2. As shown in graph GP2, the target pressure P13 is smaller than the target pressure P12 and larger than the target pressure P11. As shown in graph GP3, the target pressure P21 is smaller than the target pressure P20. In addition, in the example of graphs GP3 and GP4, the target pressure P13 and the target pressure P21 are approximately the same. In the period T43, as shown in graph GP4, the differential pressure DF is approximately zero.

As shown in FIG. 11 and graphs GP3 and GP4, after time t7, valve 5 is opened and processing liquid is supplied from external circulation pipe 60 to pipe 6. As a result, nozzle 18 ejects processing liquid onto substrate W. In this case, as shown in graph GP4, after time t7, differential pressure DF is approximately zero. Therefore, particles are prevented from diffusing from filter 37 due to differential pressure DF. As a result, particles contained in processing liquid ejected onto substrate W by nozzle 18 can be effectively reduced.

(Embodiment 2)
A substrate processing apparatus 100 according to a second embodiment of the present invention will be described with reference to Figs. 4, 13, and 14. The second embodiment mainly differs from the first embodiment in that the second embodiment performs external circulation drainage. The overall configurations of the substrate processing apparatus 100 and the processing unit 1 according to the second embodiment are the same as those of the substrate processing apparatus 100 and the processing unit 1 according to the first embodiment described with reference to Figs. 1 and 2, respectively. The overall configuration of the processing liquid supplying apparatus 200 according to the second embodiment is the same as that of the processing liquid supplying apparatus 200 according to the first embodiment described with reference to Fig. 3. The overall configuration of the substrate processing method according to the second embodiment is the same as that of the substrate processing method according to the first embodiment described with reference to Fig. 4. Therefore, Fig. 4 will be referred to as appropriate in the description of the second embodiment. Hereinafter, the differences between the second embodiment and the first embodiment will be mainly described.

First, the substrate processing method will be described with reference to FIG. 4. As shown in FIG. 4, the substrate processing method according to the second embodiment includes steps S1 to S10, similar to the first embodiment. Also, similar to the first embodiment, steps S1 to S5 constitute the processing liquid flow method according to the second embodiment.

Steps S1 to S4 according to the second embodiment are similar to steps S1 to S4 according to the first embodiment. Furthermore, steps S6 to S10 according to the second embodiment are similar to steps S6 to S10 according to the first embodiment. Furthermore, step S5 according to the second embodiment is similar to step S5 according to the first embodiment in that the treatment liquid supply device 200 externally circulates the treatment liquid. However, the main difference between the second embodiment and the first embodiment is that the second embodiment performs external circulation drainage.

Next, the external circulation operation of step S5 according to the second embodiment will be described with reference to FIG. 13 and FIG. 14. FIG. 13 is a flow chart showing the external circulation operation performed in step S5 of FIG. 4 in the second embodiment. FIG. 14 is a diagram showing the external circulation drainage operation of the processing liquid supplying device 200 according to the second embodiment. As shown in FIG. 14, the processing liquid supplying device 200 according to the second embodiment further includes a valve 51, a valve 52, and a drainage pipe 53. The drainage pipe 53 branches off from the second circulation pipe 602 downstream of the valve 43. The valve 51 is disposed in the drainage pipe 53 and opens and closes the flow path of the drainage pipe 53. The valve 52 is disposed in the second circulation pipe 602 downstream of the valve 43 and opens and closes the flow path of the second circulation pipe 602. In the second embodiment, the valve 51 is closed in steps S1 to S4 and steps S6 to S10. The valve 52 is closed in steps S1 to S4. In this way, the configuration of the treatment liquid supply device 200 according to the second embodiment differs from that shown in FIG. 3, but in the following description, reference will be made to FIG. 3 as appropriate for ease of understanding.

As shown in FIG. 13, step S5 (external circulation operation) in embodiment 2 includes steps S601 to S604.

First, as shown in Figs. 3 and 13, in step S601, the control unit 21 changes the target output value of the pump 34 from the first target output value TG1 to the second target output value TG2 (TG2>TG1). This is the same as step S501 in Fig. 9. However, in step S601, the valves 51 and 52 in Fig. 15 are closed.

Next, as shown in Figures 13 and 14, in step S602, the processing liquid is started to be discharged from the external circulation pipe 60 (specifically, the second circulation pipe 602) to the drainage pipe 53. That is, in step S602, the processing liquid is discharged to the drainage pipe 53 extending from the external circulation pipe 60 (specifically, the second circulation pipe 602). Step S602 corresponds to an example of the "second drainage step" of the present invention. Also, the drainage pipe 53 corresponds to an example of the "second drainage pipe" of the present invention.

Specifically, as shown in FIG. 14, the control unit 21 opens the valves 38 and 43 of the flow rate adjustment mechanism 50. Furthermore, the control unit 21 opens the valve 51 only for the second drainage period while the valve 52 is closed. Therefore, the processing liquid flowing through the external circulation pipe 60 (second circulation pipe 602) is discharged from the drainage pipe 53 together with particles. As a result, the particles contained in the processing liquid supplied to the substrate W can be effectively reduced. On the other hand, since the valve 52 is closed, the processing liquid does not circulate through the external circulation pipe 60. Note that the second drainage period is, for example, predetermined experimentally and/or empirically. When the second drainage period has elapsed, the process proceeds to step S603.

Next, in step S603, the control unit 21 stops the discharge of the treatment liquid from the external circulation pipe 60 (specifically, the second circulation pipe 602) to the drainage pipe 53 and starts external circulation. Specifically, the control unit 21 closes valve 51 and opens valve 52 while keeping valves 38 and 43 open. Thus, the discharge of the treatment liquid is stopped, and the treatment liquid stored in the treatment liquid tank 30 circulates through the external circulation pipe 60.

Next, in step S604, the control unit 21 adjusts the differential pressure DF between the first pressure P1 and the second pressure P2 by the valve 43 of the flow rate adjustment mechanism 50. Specifically, the control unit 21 controls the valve 43 of the flow rate adjustment mechanism 50 so that the differential pressure DF after the flow path of the external circulation pipe 60 (specifically the second circulation pipe 602) is opened is smaller than the differential pressure DF before the flow path of the external circulation pipe 60 is opened. Step S604 may be performed continuously during the period when the treatment liquid is performing external circulation, or may be performed for a predetermined adjustment period from the start of external circulation in step S603. Otherwise, step S604 is the same as step S503 in FIG. 9. Step S604 corresponds to an example of the "differential pressure adjustment step" of the present invention.

As described above with reference to FIG. 13, in the substrate processing method according to the second embodiment, in step S604, the differential pressure DF after the start of external circulation is made smaller than the differential pressure DF before the start of external circulation. As a result, it is possible to effectively prevent particles from diffusing from the filter 37 due to the differential pressure DF.

The above describes the embodiments of the present invention with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In addition, the components disclosed in the above embodiments can be modified as appropriate. For example, a component among all the components shown in one embodiment may be added to a component of another embodiment, or some of all the components shown in one embodiment may be deleted from the embodiment.

The drawings show each component diagrammatically to facilitate understanding of the invention, and the thickness, length, number, spacing, etc. of each component shown may differ from the actual configuration due to the convenience of creating the drawings. Furthermore, the configuration of each component shown in the above embodiment is merely an example and is not particularly limited, and it goes without saying that various modifications are possible within a range that does not substantially deviate from the effects of the present invention.

(1) In the first and second embodiments, the processing liquid circulation method shown in FIG. 4 may include at least steps S1, S5, and S201 (FIG. 5). This is because particles contained in the processing liquid can be effectively removed. Therefore, the processing liquid circulation method may not include steps S2 (excluding step S201), S3, and S4. However, the processing liquid circulation method may include one or more steps of steps S2 to S4. Also, in FIG. 9, the order of steps S501 to S503 is not particularly limited, as long as step S503 is performed after step S502, for example. Also, in FIG. 9, steps S501 to S503 may be performed approximately simultaneously, for example. Furthermore, in FIG. 13, steps S2 and S3 may be performed after step S4, for example. However, in this case, external circulation is started before the execution of step S4.

(2) In the treatment liquid circulation method shown in FIG. 4, the target output value set for the pump 34 may be set to a value smaller than the target output value set for the pump 34 during internal circulation, and then the external circulation of step S5 may be performed. In this case, before the external circulation of step S5 is performed, the first pressure P1 decreases in response to the decrease in the target output value of the pump 34, and the differential pressure DF between the first pressure P1 and the second pressure P2 also decreases. As a result, the diffusion of particles from the filter 37 due to the differential pressure DF can be more effectively suppressed.

For example, before stopping the internal circulation in step S3, the control unit 21 changes the target output value of the pump 34 from the first target output value TG1 to the third target output value TG3, and stops the internal circulation after changing the target output value. Or, for example, before stopping the drainage from the filter 37 in step S4, the control unit 21 changes the target output value of the pump 34 from the first target output value TG1 to the third target output value TG3, and stops the drainage after changing the target output value. The third target output value TG3 is smaller than the first target output value TG1 (FIG. 12).

(3) In step S602 of FIG. 13, the control unit 21 may open valves 5, 8, 38, 43, and 52 and close valve 51. In this case, a pre-dispense process is performed and the nozzle 14 ejects the processing liquid into the waiting pod 17. Therefore, the processing liquid flowing through the external circulation piping 60 is discharged together with the particles through the nozzle 14 and the waiting pod 17 into the piping 6. Then, in step S603 of FIG. 13, the control unit 21 closes valves 5 and 8. As a result, external circulation of the processing liquid is performed.

(4) In the first and second embodiments, the target output value set for the pump 34 is changed, but in steps S1 to S10 of FIG. 4, the target output value set for the pump 34 may be constant.

(5) In the first and second embodiments, the differential pressure DF is the value obtained by subtracting the second pressure P2 from the first pressure P1 (DF = P1 - P2). However, the differential pressure DF may be the absolute value of the difference between the first pressure P1 and the second pressure P2.

The present invention relates to a treatment liquid distribution method and a treatment liquid supply device, and has industrial applicability.

14 Nozzle 21 Control unit 30 Processing liquid tank 34 Pump 37 Filter 50 Flow rate adjustment mechanism 53 Drainage pipe (second drainage pipe)
60 External circulation piping (first piping)
61 Internal circulation piping (second piping)
62 Drainage pipe (first drainage pipe)
200 Processing liquid supply device P1 First pressure gauge (first pressure detection unit)
P2 Second pressure gauge (second pressure detection unit)
W substrate

Claims (8)

1. A method for distributing a processing liquid to be supplied to a nozzle that ejects the processing liquid onto a substrate, comprising the steps of:
a monitoring step of monitoring a first pressure indicating a pressure on a primary side of a filter disposed in a first pipe and configured to capture particles contained in the treatment liquid, and a second pressure indicating a pressure on a secondary side of the filter;
a driving step of driving a pump disposed upstream of the filter and configured to send the treatment liquid to the first pipe;
a circulating step of circulating the treatment liquid through the first piping by opening the flow path of the first piping, which is in a closed state, at a position downstream of the filter while the pump is driven,
the circulation step includes a differential pressure adjustment step of making the differential pressure between the first pressure and the second pressure after the flow path of the first piping is opened smaller than the differential pressure between the first pressure and the second pressure before the flow path of the first piping is opened, based on monitoring results of the first pressure and the second pressure. one end and the other end of the first pipe are connected to a treatment liquid tank that stores the treatment liquid,
In the circulation step, the treatment liquid is circulated through the first pipe,
2. The treatment liquid circulation method according to claim 1, wherein in the differential pressure adjustment process, the pressure on the secondary side of the filter is adjusted based on the monitoring results of the first pressure and the second pressure, so that the differential pressure after the flow path of the first piping is opened is smaller than the differential pressure before the flow path of the first piping is opened. The treatment liquid circulating method according to claim 2, further comprising a circulation step of circulating the treatment liquid in the second pipe by opening a flow path of the second pipe extending from the first pipe to the treatment liquid tank after the driving step and before the circulation step. The method for circulating a treated liquid according to claim 3, further comprising a first drainage step of discharging the treated liquid into a first drainage pipe extending from the filter after the circulation step and before the circulation step. The treatment liquid circulation method according to claim 3 or 4, wherein in the circulation step, a target output value set for the pump is set to a value greater than a target output value set for the pump when circulating the treatment liquid in the second pipe. The treatment liquid distribution method according to any one of claims 1 to 5, wherein the distribution process includes a second drainage process of discharging the treatment liquid into a second drainage pipe extending from the first pipe. The treatment liquid flow method according to any one of claims 1 to 6, wherein in the differential pressure adjustment step, the differential pressure after the flow path of the first pipe is opened is adjusted so that the differential pressure falls within a predetermined range. A processing liquid supplying apparatus for supplying a processing liquid to a nozzle that ejects the processing liquid onto a substrate, comprising:
a first pipe through which the treatment liquid flows;
a filter disposed in the first pipe and configured to capture particles contained in the treatment liquid;
A first pressure detection unit that detects a first pressure indicating a pressure on a primary side of the filter;
A second pressure detection unit that detects a second pressure indicating a pressure on the secondary side of the filter;
a pump disposed upstream of the filter and configured to pump the treatment liquid into the first pipe;
a flow rate adjusting mechanism that is disposed in the first pipe downstream of the filter and adjusts a flow rate of the treatment liquid flowing through the first pipe;
A control unit that controls the flow rate adjustment mechanism,
The control unit is
Driving the pump that is stopped;
controlling the flow rate adjustment mechanism to open a flow path of the first pipe that is in a closed state while the pump is driven;
a processing liquid supplying apparatus that controls the flow rate adjustment mechanism based on monitoring results of the first pressure and the second pressure so that a differential pressure between the first pressure and the second pressure after the flow path of the first piping is opened is smaller than a differential pressure between the first pressure and the second pressure before the flow path of the first piping is opened.

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