Substrate processing apparatus and substrate processing method

Abstract

This substrate processing device comprises: a substrate holding unit that holds a substrate horizontally; a first processing liquid supply unit that supplies a first processing liquid to the surface of the substrate held by the substrate holding unit; a second processing liquid supply unit that supplies a second processing liquid replacing the first processing liquid on the surface of the substrate held by the substrate holding unit; and a potentiometer that measures the electric potential at the outer periphery of the surface of the substrate held by the substrate holding unit.

Description

[Technical Field]

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

[0002] The substrate processing apparatus described in Patent Document 1 supplies DIW (deionized water) and IPA (isopropyl alcohol) in this order to the upper surface of a substrate. When replacing the DIW supplied to the upper surface of the substrate with IPA, the substrate processing apparatus supplies IPA to the center of the upper surface of the substrate and replenishes DIW to the outer periphery of the upper surface of the substrate. After stopping the supply of DIW, the substrate processing apparatus supplies IPA to the center of the upper surface of the substrate for a predetermined period of time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent No. 6118758 Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present disclosure provides a technique for reducing the consumption of a second processing liquid that replaces a first processing liquid. [Means for solving the problem]

[0005] A substrate processing apparatus according to one aspect of the present disclosure includes a substrate holding unit that holds a substrate horizontally, a first processing liquid supply unit that supplies a first processing liquid to a surface of the substrate held by the substrate holding unit, a second processing liquid supply unit that supplies a second processing liquid that replaces the first processing liquid to the surface of the substrate held by the substrate holding unit, and an electrometer that measures a potential of an outer periphery of the surface of the substrate held by the substrate holding unit. and a control unit that controls the first processing liquid supply unit, the second processing liquid supply unit, and the electrometer. The control unit controls the electrometer to measure measurement data related to changes in the potential depending on the supply time of the second processing liquid, and controls the measurement data to be stored in a memory unit. The control unit determines the time to end the supply of the second processing liquid based on the time at which a difference between two potentials measured at a unit time interval in the measurement data stored in the memory unit reaches a threshold value or less. [Effects of the Invention]

[0006] According to one aspect of the present disclosure, it is possible to reduce the consumption amount of the second treatment liquid that replaces the first treatment liquid. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view showing a substrate processing apparatus according to an embodiment. [Figure 2] FIG. 2 is a plan view showing an example of the first nozzle moving section and the second nozzle moving section. [Figure 3] FIG. 3 is a flowchart showing a substrate processing method according to an embodiment. [Figure 4] Figure 4(A) is a diagram showing an example of step S101, Figure 4(B) is a diagram showing an example of the first stage of step S102, Figure 4(C) is a diagram showing an example of the second stage of step S102, and Figure 4(D) is a diagram showing an example of the third stage of step S102. [Figure 5] Figure 5(A) is a diagram showing an example of the first stage of step S103, Figure 5(B) is a diagram showing an example of the second stage of step S103, Figure 5(C) is a diagram showing an example of step S104, Figure 5(D) is a diagram showing an example of step S105, and Figure 5(E) is a diagram showing an example of step S106. [Figure 6] FIG. 6 is a diagram showing an example of experimental data regarding IPA supply time. [Figure 7] FIG. 7 is a diagram showing an example of experimental data regarding IPA supply time and potential distribution. [Figure 8] Figure 8(A) is a diagram showing an example of the potential distribution when DIW is being supplied, Figure 8(B) is a diagram showing an example of the potential distribution during the replacement of DIW with IPA, Figure 8(C) is a diagram showing an example of the potential distribution at the end of the supply of IPA, and Figure 8(D) is a diagram showing an example of the potential distribution after drying. [Figure 9] FIG. 9 is a diagram showing an example of the change in potential at the outer periphery of the upper surface of the substrate depending on the supply time of IPA in step S104. DETAILED DESCRIPTION OF THE INVENTION

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

[0009] A substrate processing apparatus 1 according to one embodiment will be described with reference to FIGS. 1 and 2. The substrate processing apparatus 1 processes the substrate W by supplying a processing liquid to the substrate W. The substrate processing apparatus 1 supplies, for example, a chemical liquid, a rinse liquid, and a drying liquid to the substrate W in this order as the processing liquid. The chemical liquid is not particularly limited, but may be, for example, DHF (dilute hydrofluoric acid). The rinse liquid is not particularly limited, but may be, for example, DIW (deionized water). The drying liquid is not particularly limited, but may be, for example, IPA (isopropyl alcohol). The drying liquid may have a lower surface tension than the rinse liquid. It is sufficient that the drying liquid can prevent pattern collapse on the substrate W due to surface tension. The substrate processing apparatus 1 may supply a drying gas to the substrate W. The drying gas is, for example, nitrogen gas. Note that the drying gas is not limited to nitrogen gas. The drying gas may be, for example, dry air.

[0010] The substrate processing apparatus 1 includes, for example, a processing vessel 10, a substrate holding unit 20, a substrate rotating unit 25, a chemical liquid supply unit 31, a first rinsing liquid supply unit 32, a drying liquid supply unit 33, a second rinsing liquid supply unit 34, a first drying gas supply unit 35, a second drying gas supply unit 36, a chemical liquid / rinsing liquid nozzle 41, a drying liquid nozzle 42, a rinsing liquid nozzle 43, a first drying gas nozzle 44, a second drying gas nozzle 45, a first nozzle moving unit 51, a second nozzle moving unit 52, a recovery unit 60, and a control unit 90.

[0011] The processing vessel 10 accommodates a substrate holder 20 and the like. A gate 12 and a gate valve 13 for opening and closing the gate 12 are provided on a sidewall of the processing vessel 10. A substrate W is loaded into the processing vessel 10 through the gate 12 by a transfer device (not shown). Next, the substrate W is processed with a processing solution inside the processing vessel 10. Thereafter, the substrate W is unloaded from the processing vessel 10 through the gate 12 by the transfer device.

[0012] The substrate holding unit 20 is provided inside the processing vessel 10 and holds the substrate W horizontally. The substrate holding unit 20 has, for example, claws 21 that hold the outer periphery of the substrate W. A plurality of claws 21 are provided at equal intervals in the circumferential direction of the substrate W. Although not shown, the substrate holding unit 20 may vacuum-suck the underside of the substrate W. The substrate rotation unit 25 rotates the substrate holding unit 20, thereby rotating the substrate W together with the substrate holding unit 20.

[0013] The chemical liquid supply unit 31 supplies a chemical liquid to the substrate W through the chemical liquid / rinse liquid nozzle 41. The first rinse liquid supply unit 32 supplies a rinse liquid to the substrate W through the chemical liquid / rinse liquid nozzle 41. The drying liquid supply unit 33 supplies a drying liquid to the substrate W through the drying liquid nozzle 42. The chemical liquid / rinse liquid nozzle 41 and the drying liquid nozzle 42 are disposed above the substrate W, and supply the processing liquid to the substrate upper surface Wa. Note that instead of the chemical liquid / rinse liquid nozzle 41, a chemical liquid nozzle and a rinse liquid nozzle may be provided separately.

[0014] The second rinsing liquid supply unit 34 supplies a rinsing liquid to the substrate W via a rinsing liquid nozzle 43. The first drying gas supply unit 35 supplies a drying gas to the substrate W via a first drying gas nozzle 44. The second drying gas supply unit 36 ​​supplies a drying gas to the substrate W via a second drying gas nozzle 45. The rinsing liquid nozzle 43, the first drying gas nozzle 44, and the second drying gas nozzle 45 are disposed above the substrate W, and supply a processing liquid or a drying gas to the upper surface Wa of the substrate.

[0015] The chemical liquid supply unit 31, the first rinse liquid supply unit 32, the drying liquid supply unit 33, the second rinse liquid supply unit 34, the first drying gas supply unit 35, and the second drying gas supply unit 36 ​​each include, for example, an on-off valve, a flow meter, and a flow controller (not shown). The on-off valve opens and closes the flow path of the processing liquid or the drying gas. The flow meter measures the flow rate of the processing liquid or the drying gas. The flow controller controls the flow rate of the processing liquid or the drying gas so that the measured value of the flow meter becomes a set value.

[0016] The first nozzle moving unit 51 moves the rinse liquid nozzle 43, the first drying gas nozzle 44, and the second drying gas nozzle 45. The first nozzle moving unit 51 includes, for example, a first arm 51a and a first turning mechanism 51b, as shown in FIG. 2. The first turning mechanism 51b turns the first arm 51a to move the rinse liquid nozzle 43, the first drying gas nozzle 44, and the second drying gas nozzle 45 in the horizontal direction. The first turning mechanism 51b also moves the rinse liquid nozzle 43, the first drying gas nozzle 44, and the second drying gas nozzle 45 in the vertical direction by raising and lowering the first arm 51a.

[0017] The first nozzle moving unit 51 may include a guide rail and a linear motion mechanism instead of the first arm 51 a and the first pivot mechanism 51 b. The linear motion mechanism moves the rinse liquid nozzle 43, the first drying gas nozzle 44, and the second drying gas nozzle 45 in the horizontal and vertical directions along the guide rail.

[0018] The second nozzle moving unit 52 moves the chemical / rinse liquid nozzle 41 and the drying liquid nozzle 42 independently of the rinse liquid nozzle 43 and the like. The second nozzle moving unit 52 has, for example, a second arm 52a and a second turning mechanism 52b, as shown in FIG. 2 . The second turning mechanism 52b turns the second arm 52a to move the chemical / rinse liquid nozzle 41 and the drying liquid nozzle 42 in the horizontal direction. The second turning mechanism 52b also moves the chemical / rinse liquid nozzle 41 and the drying liquid nozzle 42 in the vertical direction by raising and lowering the second arm 52a.

[0019] Second nozzle moving unit 52 may have a guide rail and a linear motion mechanism instead of second arm 52 a and second pivot mechanism 52 b. The linear motion mechanism moves chemical / rinse liquid nozzle 41 and drying liquid nozzle 42 horizontally and vertically along the guide rail.

[0020] In this embodiment, the rinse liquid corresponds to the first processing liquid, the second rinse liquid supply unit 34 corresponds to the first processing liquid supply unit, and the rinse liquid nozzle 43 corresponds to the first nozzle. In addition, in this embodiment, the drying liquid corresponds to the second processing liquid, the drying liquid supply unit 33 corresponds to the second processing liquid supply unit, and the drying liquid nozzle 42 corresponds to the second nozzle.

[0021] The combination of the first and second processing liquids is not particularly limited as long as the second processing liquid replaces the first processing liquid. For example, the first processing liquid may be a chemical liquid and the second processing liquid may be a rinse liquid. The first processing liquid and the second processing liquid may be ejected in sequence from the same nozzle. The nozzle may be disposed below the substrate W and may supply the processing liquid or drying gas to the lower surface Wb of the substrate.

[0022] The recovery unit 60 recovers the processing liquid supplied to the substrate W. The recovery unit 60 has, for example, a cup 61. The cup 61 surrounds the outer periphery of the substrate W held by the substrate holding unit 20 and receives the processing liquid splashed from the outer periphery of the substrate W. In this embodiment, the cup 61 does not rotate together with the substrate holding unit 20, but it may rotate together with the substrate holding unit 20. A drain pipe 62 and an exhaust pipe 63 are provided at the bottom of the cup 61. The drain pipe 62 discharges liquid accumulated inside the cup 61. The exhaust pipe 63 discharges gas accumulated inside the cup 61.

[0023] The control unit 90 is, for example, a computer, and includes a CPU (Central Processing Unit) 91 and a storage unit 92 such as a memory. The storage unit 92 stores programs that control various processes executed in the substrate processing apparatus 1. The control unit 90 controls the operation of the substrate processing apparatus 1 by causing the CPU 91 to execute the programs stored in the storage unit 92.

[0024] A substrate processing method according to one embodiment will be described with reference to Figures 3 to 5. The substrate processing method includes, for example, steps S101 to S106 as shown in Figure 3. Steps S101 to S106 are performed under the control of the control unit 90. The processing from step S101 onwards starts when a transfer device (not shown) loads a substrate W into the processing vessel 10 and the substrate holder 20 holds the substrate W horizontally. Note that the substrate processing method does not necessarily have to include steps S103 and S105.

[0025] As shown in FIG. 4(A), step S101 includes the chemical liquid supply unit 31 (see FIG. 1) supplying the chemical liquid L1 to the substrate W via the chemical liquid / rinse liquid nozzle 41. The chemical liquid / rinse liquid nozzle 41 supplies the chemical liquid L1 to the center of the substrate upper surface Wa. The substrate W is being rotated, and the chemical liquid L1 flows radially outward from the substrate upper surface Wa due to centrifugal force, forming a liquid film over the entire substrate upper surface Wa.

[0026] As shown in FIG. 4(B), step S102 includes the first rinse liquid supply unit 32 (see FIG. 1) supplying rinse liquid L2 to the substrate W via the chemical / rinse liquid nozzle 41. The chemical / rinse liquid nozzle 41 supplies rinse liquid L2 to the center of the substrate upper surface Wa. The substrate W is being rotated, and the rinse liquid L2 flows radially outward from the substrate upper surface Wa due to centrifugal force, forming a liquid film over the entire substrate upper surface Wa. The chemical liquid L1 is replaced with the rinse liquid L2.

[0027] Step S102 may include preparation for performing step S103, as shown in Figures 4(C) and 4(D). Note that, as described above, step S103 does not have to be performed. If step S103 is not performed, step S102 does not include preparation for step S103. If step S104 is performed subsequent to step S102 without performing step S103, the chemical liquid / rinse liquid nozzle 41 may supply drying liquid L3 to the center of the substrate upper surface Wa in step S104.

[0028] When step S103 is performed, step S102 includes, for example, as shown in FIG. 4C, the chemical / rinse liquid nozzle 41 and the rinse liquid nozzle 43 simultaneously ejecting the rinse liquid L2. In this state, the second nozzle movement unit 52 moves the chemical / rinse liquid nozzle 41 radially outward from the substrate upper surface Wa, and the first nozzle movement unit 51 moves the rinse liquid nozzle 43 radially inward from the substrate upper surface Wa. This allows the nozzle positioned directly above the center of the substrate upper surface Wa to be replaced without interrupting the supply of the rinse liquid L2. As shown in FIG. 4D, when the rinse liquid nozzle 43 reaches directly above the center of the substrate upper surface Wa, the chemical / rinse liquid nozzle 41 stops ejecting the rinse liquid L2. Meanwhile, the rinse liquid nozzle 43 stops moving directly above the center of the substrate upper surface Wa and continues ejecting the rinse liquid L2 onto the center of the substrate upper surface Wa.

[0029] 5(A) and 5(B), step S103 includes the second rinsing liquid supply unit 34 (see FIG. 1) supplying rinsing liquid L2 to the substrate upper surface Wa via the rinsing liquid nozzle 43, and the drying liquid supply unit 33 (see FIG. 1) supplying drying liquid L3 to the substrate upper surface Wa via the drying liquid nozzle 42. The supply of rinsing liquid L2 and the supply of drying liquid L3 are performed simultaneously. In this state, the first nozzle movement unit 51 moves the rinsing liquid nozzle 43 radially outward from the substrate upper surface Wa, and the second nozzle movement unit 52 moves the drying liquid nozzle 42 radially inward from the substrate upper surface Wa. This makes it possible to replace the nozzle located directly above the center of the substrate upper surface Wa while suppressing drying of the substrate upper surface Wa.

[0030] As shown in FIG. 5A, the drying liquid nozzle 42 stops moving directly above the center of the substrate upper surface Wa and continues to discharge the drying liquid L3 onto the center of the substrate upper surface Wa. In this state, as shown in FIG. 5B, the rinsing liquid nozzle 43 continues to move radially outward from the substrate upper surface Wa and continues to discharge the rinsing liquid L2. As the drying liquid L3 spreads radially outward, the rinsing liquid L2 is replenished in front of the drying liquid L3. This prevents the liquid film from being interrupted. The rinsing liquid nozzle 43 stops discharging the rinsing liquid after reaching directly above the outer periphery of the substrate upper surface Wa.

[0031] As shown in FIG. 5(C), step S104 includes the drying liquid supply unit 33 (see FIG. 1) supplying the drying liquid L3 onto the upper surface Wa of the substrate via the drying liquid nozzle 42. The drying liquid nozzle 42 supplies the drying liquid L3 to the center of the upper surface Wa of the substrate. The substrate W is being rotated, and the drying liquid L3 flows radially outward from the upper surface Wa of the substrate due to centrifugal force, forming a liquid film over the entire upper surface Wa of the substrate. The rinsing liquid L2 is replaced with the drying liquid L3.

[0032] 5(D), step S105 includes the second nozzle moving unit 52 moving the drying liquid nozzle 42 radially outward from the substrate upper surface Wa. The drying liquid nozzle 42 moves from directly above the center of the substrate upper surface Wa to directly above the outer periphery of the substrate upper surface Wa while discharging the drying liquid L3. This allows the boundary between the exposed portion and the covered portion of the substrate upper surface Wa to gradually expand concentrically radially outward from the substrate upper surface Wa. The exposed portion is the portion exposed from the drying liquid L3, and the covered portion is the portion covered with the drying liquid L3.

[0033] 5(D), step S105 may include constricting the boundary between the exposed portion and the covered portion of the substrate upper surface Wa by discharging dry gas from the second drying gas nozzle 45 to the boundary. The discharge direction of the second drying gas nozzle 45 is inclined radially outward as it extends vertically downward. The second drying gas nozzle 45 moves radially outward of the substrate upper surface Wa while discharging dry gas.

[0034] Note that step S105 may include using the first drying gas nozzle 44, instead of the second drying gas nozzle 45, to discharge dry gas onto the boundary between the exposed portion and the covered portion of the substrate upper surface Wa, thereby suppressing the boundary. The discharge direction of the first drying gas nozzle 44 is directly downward. As described above, step S105 does not have to be performed. By not performing step S105, the consumption of drying liquid L3 can be reduced.

[0035] 5(E), step S106 includes drying the substrate W by rotating the substrate W with the substrate rotation unit 25 (see FIG. 1). By rotating the substrate W while the supply of the processing liquid to the substrate W is stopped, the processing liquid adhering to the substrate W can be shaken off, and the substrate W can be dried. Thereafter, the substrate W is transported to the outside of the processing container 10 by a transport device (not shown).

[0036] As shown in FIG. 6, the inventors investigated shortening the IPA supply time in order to reduce the consumption of IPA, which is the drying liquid L3. Specifically, the inventors investigated the relationship between the IPA supply time in step S104 and the quality of the substrate upper surface Wa after drying. The quality of the substrate upper surface Wa was evaluated based on three items: (A) the number of particles attached, (B) the collapse rate of the uneven pattern, and (C) the electric potential of the outer periphery. Charging of the substrate W can cause electrostatic breakdown or particle attachment in subsequent processes.

[0037] The evaluation in Fig. 6 is an evaluation when steps S101 to S104 and S106 in Fig. 3 are performed, excluding step S105. An evaluation of "OK" means that a quality equivalent to the standard quality is obtained. Also, in Fig. 6, an evaluation of "NG" means that a quality lower than the standard quality is obtained. The standard quality is the quality when all of steps S101 to S106 are performed without shortening the IPA supply time in step S104.

[0038] As is clear from Figure 6, of the three items (A) number of attached particles, (B) collapse rate of the uneven pattern, and (C) potential of the outer periphery, it was found that (C) potential of the outer periphery is most likely to fluctuate with the IPA supply time. Figure 7 shows the radial distribution of the potential on the upper surface Wa of the substrate. As is clear from Figure 7, there was a tendency for the shorter the IPA supply time, the higher the potential of the outer periphery. It has been confirmed that when the potential distribution is the standard distribution (standard quality) shown by the solid line in Figure 7, no problems will occur in the next process, etc.

[0039] An example of the radial distribution of the potential on the substrate upper surface Wa will be described with reference to FIG. 8. In FIG. 8, the dashed-dotted line L indicates the rotation center line of the substrate W. As shown in FIG. 8(A), when DIW is supplied, the substrate upper surface Wa becomes negatively charged except for the outer periphery of the substrate upper surface Wa. This is thought to be because negatively charged OH groups adhere to the substrate upper surface Wa. Meanwhile, at the outer periphery of the substrate upper surface Wa, negative ions are scattered by the DIW scattering, and positive ions remain on the substrate upper surface Wa.

[0040] As shown in Figure 8(B), the replacement of DIW with IPA proceeds from the center of the upper surface Wa of the substrate toward the periphery of the upper surface Wa of the substrate. As shown in Figure 8(C), if the replacement of DIW with IPA is insufficient at the periphery of the upper surface Wa of the substrate, positive ions remain. As a result, as shown in Figure 8(D), the periphery of the upper surface Wa of the substrate after drying is thought to be positively charged.

[0041] An example of the change in the potential of the outer periphery of the substrate upper surface Wa depending on the supply time of IPA in step S104 will be described with reference to Fig. 9. As shown in Fig. 9, the longer the supply time of IPA in step S104, the lower the potential of the outer periphery of the substrate upper surface Wa. This is thought to be because the replacement of DIW with IPA progresses in the outer periphery of the substrate upper surface Wa, and + ions are removed.

[0042] Based on the above findings, the inventors of the present application have discovered that monitoring the potential of the outer periphery of the upper surface Wa of the substrate can reduce the amount of IPA consumed while maintaining the quality of the substrate W. As shown in Fig. 9, the longer the IPA supply time in step S104, the more gradual the change in potential becomes. If the supply of IPA is terminated when the difference (≧0) between the two potentials measured at a unit time interval reaches a threshold value or less, the amount of IPA consumed can be reduced while maintaining the quality of the substrate W.

[0043] 5(C), the substrate processing apparatus 1 is equipped with electrometers 71 and 72. The electrometers 71 and 72 measure the potential of the outer periphery of the upper surface Wa of the substrate held by the substrate holder 20. The upper surface Wa of the substrate includes a horizontal surface and a beveled surface. The outer periphery of the upper surface Wa of the substrate refers to a portion within 30 mm from the outer periphery of the upper surface Wa of the substrate.

[0044] The substrate processing apparatus 1 may include only one of the electrometers 71 and 72. When the nozzle supplies the processing liquid to the substrate lower surface Wb, the electrometers 71 and 72 may measure the potential of the outer periphery of the substrate lower surface Wb. The substrate lower surface Wb includes a horizontal surface and a beveled surface.

[0045] The control unit 90 controls the electrometers 71 and 72 to measure measurement data (for example, the measurement data shown in FIG. 9) relating to the change in potential depending on the supply time of the drying liquid L3, and controls the storage of the measurement data in the memory unit 92. When the potential of the outer periphery of the substrate upper surface Wa is measured at multiple locations in the circumferential direction of the substrate W, the average value of the measurement values ​​may be stored in the memory unit 92. The control unit 90 determines the time to stop the supply of the drying liquid L3 based on the measurement data stored in the memory unit 92.

[0046] For example, the control unit 90 determines the time to stop supplying the drying liquid L3 based on the time when the difference (≧0) between two potentials measured at an interval of a unit time reaches a threshold value or less. The difference (≧0) between the two potentials measured at an interval of a unit time represents the rate of change in potential. The threshold value is set in advance by experiment or the like, taking into consideration the quality of the substrate W and the consumption amount of the drying liquid L3.

[0047] By determining the time to end the supply of the drying liquid L3 based on the time when the difference (≧0) between two potentials measured at an interval of a unit time reaches a threshold value or less, it is possible to reduce the consumption of the drying liquid L3 while maintaining the quality of the substrate W. The control unit 90 may end the supply of the drying liquid L3 when the difference reaches a threshold value or less, or may end the supply of the drying liquid L3 when a desired delay time has elapsed since the difference reached a threshold value or less.

[0048] The control unit 90 may determine the time to end the supply of the drying liquid L3 based on the potential itself instead of the rate of change of the potential. For example, the control unit 90 may determine the time to end the supply of the drying liquid L3 based on the time when the potential reaches a threshold value or less.

[0049] The control unit 90 determines the time to end the supply of the drying liquid L3, thereby determining, for example, the supply time of the drying liquid L3 in step S104. Thereafter, the control unit 90 may perform step S104 for the determined supply time of the drying liquid L3. Therefore, it is not necessary to acquire the measurement data as shown in FIG. 9 every time a substrate W is processed.

[0050] 5(C), the control unit 90 may perform control such that the electrometers 71 and 72 measure the potential every unit time while the drying liquid L3 is being supplied to the substrate W. During processing of the substrate W, measurement data relating to the change in potential depending on the supply time of the drying liquid L3 can be obtained. Therefore, measurement data can be created using the same single substrate W.

[0051] Although not shown, the control unit 90 may perform control to repeatedly measure the potential with the electrometers 71 and 72 after drying the substrate W while changing the supply time of the drying liquid L3. In this case, the potential can be measured after the rotation of the substrate W has stopped. Therefore, the electrometers 71 and 72 can be contact-type and wired.

[0052] The electrometer 71 may be a surface electrometer that measures the potential at a distance from the substrate upper surface Wa. The surface electrometer is a non-contact type. The electrometer 71 does not rotate with the substrate W, so it can measure the potential of the outer periphery of the substrate upper surface Wa over the entire circumferential direction of the substrate W. Furthermore, since the electrometer 71 does not rotate with the substrate W, it can transmit the measurement data to the control unit 90 via a wired connection. However, the electrometer 71 can also transmit the measurement data to the control unit 90 wirelessly.

[0053] The electrometer 71 may be moved together with the rinse liquid nozzle 43 by the first nozzle moving unit 51. This can prevent interference between the substrate W and the electrometer 71 when the substrate W is loaded or unloaded. Furthermore, the electrometer 71 can be moved using existing equipment. However, if cost is not an issue, a moving unit for moving the electrometer 71 may be newly installed.

[0054] 5(C), the electrometer 72 may be in contact with the claws 21 of the substrate holder 20 and electrically connected to the outer periphery of the substrate W via the claws 21. The electrometer 72 is of a contact type. There may be multiple electrometers 72, and the multiple electrometers 72 may be in contact with different claws 21. The potential of the outer periphery of the substrate W can be measured at multiple points in the circumferential direction of the substrate W.

[0055] The electrometer 72 may be fixed to the claw portion 21, or may rotate together with the substrate W. When the electrometer 72 rotates together with the substrate W, it transmits measurement data to the control unit 90 wirelessly.

[0056] The electrometer 72 may be brought into contact with or separated from the claws 21 so as not to rotate together with the substrate W. For example, while the substrate W is rotating, the electrometer 72 is separated from the claws 21. When the drying of the substrate W is completed and the rotation of the substrate W stops, the electrometer 72 is brought into contact with the claws 21. After the substrate W is dried, the electrometer 72 measures the potential of the outer periphery of the upper surface Wa of the substrate. When the electrometer 72 does not rotate together with the substrate W, it can transmit the measurement data to the control unit 90 via a wire.

[0057] The electrometer 72 may be provided between the claw portion 21 and the substrate W and may be in contact with the outer periphery of the substrate W. In this case, the electrometer 72 is rotated together with the substrate W. Therefore, in this case, the electrometer 72 transmits measurement data to the control unit 90 wirelessly.

[0058] Although the embodiments of the substrate processing apparatus and substrate processing method according to the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These changes also naturally fall within the technical scope of the present disclosure.

[0059] This application claims priority based on Patent Application No. 2022-086351, filed with the Japan Patent Office on May 26, 2022, and the entire contents of Patent Application No. 2022-086351 are incorporated herein by reference. [Explanation of symbols]

[0060] 1. Substrate processing equipment 20 Board holding part 33 Drying liquid supply unit (second processing liquid supply unit) 34 Second rinse liquid supply unit (first processing liquid supply unit) L2 Rinse liquid (first processing liquid) L3 Drying liquid (second processing liquid)

Claims

1. a substrate holder that holds the substrate horizontally; a first processing liquid supply unit that supplies a first processing liquid to a surface of the substrate held by the substrate holder; a second processing liquid supply unit that supplies a second processing liquid to the surface of the substrate held by the substrate holder, the second processing liquid replacing the first processing liquid; an electrometer for measuring the potential of the outer periphery of the surface of the substrate held by the substrate holder; a control unit that controls the first processing liquid supply unit, the second processing liquid supply unit, and the electrometer; Equipped with the control unit controls the electrometer to measure measurement data relating to a change in the potential depending on a supply time of the second treatment liquid, and controls the storage unit to store the measurement data; The control unit determines the time to stop supplying the second processing liquid based on the time at which the difference between the two potentials measured at a unit time interval in the measurement data stored in the memory unit reaches a threshold value or less.

2. The substrate processing apparatus according to claim 1 , wherein the control unit performs control to measure the potential with the electrometer every unit time while the second processing liquid is being supplied to the surface of the substrate.

3. 3. The substrate processing apparatus according to claim 1, wherein the electrometer is a surface electrometer that measures the potential at a distance from the surface of the substrate.

4. a first nozzle that ejects the first processing liquid onto the substrate; a first nozzle movement unit that moves the first nozzle; a second nozzle that ejects the second processing liquid onto the substrate; and a second nozzle movement unit that moves the second nozzle independently of the first nozzle; The substrate processing apparatus according to claim 3 , wherein the electrometer is moved together with the first nozzle by the first nozzle moving unit.

5. the substrate holding portion includes a claw portion that holds an outer periphery of the substrate, 3. The substrate processing apparatus according to claim 1, wherein the electrometer is in contact with the claw portion and electrically connected to the outer periphery of the substrate via the claw portion, or is provided between the claw portion and the substrate and in contact with the outer periphery of the substrate.

6. holding the substrate horizontally with a substrate holder; supplying a first processing liquid to a surface of the substrate held by the substrate holder; supplying a second processing liquid to the surface of the substrate held by the substrate holder to replace the first processing liquid; measuring the potential of the outer periphery of the surface of the substrate held by the substrate holder with an electrometer; measuring measurement data relating to a change in the potential depending on a supply time of the second treatment liquid with the electrometer; storing the measurement data in a storage unit; determining a time to terminate the supply of the second treatment liquid based on a time at which a difference between two potentials measured at an interval of a unit time in the measurement data stored in the storage unit reaches a threshold value or less; A substrate processing method comprising:

7. 7. The substrate processing method according to claim 6, further comprising measuring the potential with the electrometer every unit time while the second processing liquid is being supplied to the substrate.

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