Plating device and substrate processing method

Abstract

The present invention enhances the detection accuracy of the degree of cleaning of a substrate holder.　This plating device includes: a plating tank configured to accommodate a plating liquid; a substrate holder 440 having a contact member 494-4 for supplying power to the substrate and an electrode member 494-6 arranged in the vicinity of the contact member 494-4; a cleaning member having a cleaning nozzle 472a configured to discharge the cleaning liquid to an internal region of the substrate holder 440 in which the contact member 494-4 is arranged; a power supply 495 configured to apply a voltage between the contact member 494-4 and the electrode member 494-6; an ammeter 496 configured to measure the current flowing between the contact member 494-4 and the electrode member 494-6; and a control unit 499 for operating a detector 497 configured to detect the degree of cleaning of the internal region of the substrate holder 440 on the basis of the current measured by the ammeter 496 when the internal region of the substrate holder 440 is being cleaned using the cleaning member.

Description

Plating apparatus and substrate processing method

[0001] The present application relates to a plating apparatus and a substrate processing method.

[0002] A cup-type electrolytic plating apparatus is known as an example of a plating apparatus. In a cup-type electrolytic plating apparatus, a substrate (e.g., a semiconductor wafer) held by a substrate holder is immersed in a plating solution with the surface to be plated facing downward, and a voltage is applied between the substrate and an anode to deposit a conductive film on the surface of the substrate.

[0003] For example, Patent Document 1 discloses a plating apparatus configured to clean a substrate holder after a plating process. This plating apparatus includes a cleaning member configured to discharge a cleaning liquid onto the substrate holder after the plating process, and a tray member disposed below the cleaning member. This plating apparatus is configured to receive the cleaning liquid used to clean the substrate holder in the tray member and to detect the cleanliness of the substrate holder by measuring the electrical conductivity of the cleaning liquid flowing through the tray member.

[0004] Patent No. 7114002

[0005] Prior art plating apparatuses have room for improvement in terms of increasing the accuracy of detecting the cleanliness of the substrate holder.

[0006] In other words, since the cleaning liquid flowing through the tray member may contain some of the cleaning liquid used to clean the substrates before cleaning the substrate holder, there is a risk of loss of accuracy when detecting the cleanliness of the substrate holder based on the electrical conductivity of the cleaning liquid flowing through the tray member, as in the conventional technology. In addition, since the cleaning liquid flowing through the tray member is the one that has been flowing for a predetermined time since the substrate holder was cleaned, there is a risk that the conventional technology will not be able to accurately detect the current cleanliness of the substrate holder.

[0007] Therefore, one object of the present invention is to improve the accuracy of detecting the cleanliness of a substrate holder.

[0008] According to one embodiment, a plating apparatus is disclosed that includes: a plating tank configured to contain a plating solution; a substrate holder configured to hold a substrate with its surface to be plated facing downward, the substrate holder having a contact member for supplying power to the substrate and an electrode member arranged near the contact member; a cleaning member having a cleaning nozzle configured to discharge a cleaning solution into an internal region of the substrate holder where the contact member is arranged; a power source configured to apply a voltage between the contact member and the electrode member; an ammeter configured to measure a current flowing between the contact member and the electrode member; and a control unit that operates a detector configured to detect the cleanliness of the internal region of the substrate holder based on the current measured by the ammeter when the internal region of the substrate holder is cleaned using the cleaning member.

[0009] FIG. 1 is a perspective view showing the overall configuration of a plating apparatus according to this embodiment. FIG. 2 is a plan view showing the overall configuration of the plating apparatus according to this embodiment. FIG. 3 is a longitudinal sectional view schematically showing the configuration of a plating module according to this embodiment. FIG. 4A is a longitudinal sectional view schematically showing an enlarged portion of the configuration of a plating module according to this embodiment. FIG. 4B is a longitudinal sectional view schematically showing an enlarged portion of the configuration of a plating module according to this embodiment. FIG. 5 is a diagram showing the current of an electrode member when the internal region of a substrate holder is cleaned. FIG. 6 is a diagram showing the voltage and current of an electrode member when a substrate before plating processing is attached to a substrate holder. FIG. 7 is a diagram showing an outline of the substrate processing flow according to this embodiment. FIG. 8 is a flow chart showing the substrate processing flow according to this embodiment in detail.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings described below, the same or corresponding components are designated by the same reference numerals, and redundant description will be omitted.

[0011] <Overall Configuration of Plating Apparatus> Fig. 1 is a perspective view showing the overall configuration of the plating apparatus of this embodiment. Fig. 2 is a plan view showing the overall configuration of the plating apparatus of this embodiment. As shown in Figs. 1 and 2, the plating apparatus 1000 includes a load port 100, a transfer robot 110, an aligner 120, a presoak module 300, a plating module 400, a spin rinse dryer 600, a transfer device 700, and a control module 800.

[0012] The load port 100 is a module for loading substrates stored in a cassette such as a FOUP (not shown) into the plating apparatus 1000 and unloading substrates from the plating apparatus 1000 to the cassette. In this embodiment, four load ports 100 are arranged horizontally, but the number and arrangement of the load ports 100 are optional. The transfer robot 110 is a robot for transporting substrates and is configured to transfer substrates between the load port 100, the aligner 120, and the spin rinse dryer 600. When transferring substrates between the transfer robot 110 and the transfer apparatus 700, the transfer robot 110 and the transfer apparatus 700 can transfer the substrates via a temporary stage (not shown).

[0013] The aligner 120 is a module for aligning the positions of the orientation flat, notch, etc. of the substrate in a predetermined direction. In this embodiment, two aligners 120 are arranged side by side in the horizontal direction, but the number and arrangement of the aligners 120 are optional.

[0014] The presoak module 300 is configured to perform a presoak process, which involves etching away, for example, an oxide film with high electrical resistance present on the surface of a seed layer formed on the surface of a substrate to be plated before plating, using a treatment solution such as sulfuric acid or hydrochloric acid to clean or activate the surface of the substrate to be plated. In this embodiment, two presoak modules 300 are arranged vertically, but the number and arrangement of the presoak modules 300 are optional. The plating module 400 performs plating on the substrate. In this embodiment, two sets of 12 plating modules 400 are arranged vertically, three vertically and four horizontally, for a total of 24 plating modules 400, but the number and arrangement of the plating modules 400 are optional.

[0015] The spin rinse dryer 600 is a module for drying the substrate after cleaning by rotating it at high speed. In this embodiment, two spin rinse dryers are arranged vertically, but the number and arrangement of the spin rinse dryers are optional. The transport device 700 is a device for transporting substrates between multiple modules within the plating apparatus 1000. The control module 800 is configured to control the multiple modules of the plating apparatus 1000 and can be configured, for example, as a general computer or a dedicated computer equipped with an input / output interface with an operator.

[0016] An example of a series of plating processes performed by the plating apparatus 1000 will be described. First, a substrate stored in a cassette is loaded into the load port 100. Next, the transfer robot 110 removes the substrate from the cassette in the load port 100 and transfers the substrate to the aligner 120. The aligner 120 aligns the positions of the orientation flat, notch, etc. of the substrate to a predetermined direction. The transfer robot 110 delivers the substrate, whose direction has been aligned by the aligner 120, to the transfer apparatus 700.

[0017] The transfer device 700 transfers the substrate received from the transfer robot 110 to the plating module 400. The plating module 400 performs a pre-wet process on the substrate. The transfer device 700 transfers the substrate that has been subjected to the pre-wet process to the pre-soak module 300. The pre-soak module 300 performs a pre-soak process on the substrate. The transfer device 700 transfers the substrate that has been subjected to the pre-soak process to the plating module 400. The plating module 400 performs a plating process on the substrate. Furthermore, the plating module 400 performs a cleaning process on the substrate that has been subjected to the plating process.

[0018] The transfer device 700 transfers the substrate after cleaning to the spin rinse dryer 600. The spin rinse dryer 600 dries the substrate. The transfer robot 110 receives the substrate from the spin rinse dryer 600 and transfers the dried substrate to a cassette on the load port 100. Finally, the cassette containing the substrate is removed from the load port 100.

[0019] <Configuration of Plating Module> Next, the configuration of the plating module 400 will be described. Since the 24 plating modules 400 in this embodiment have the same configuration, only one plating module 400 will be described. FIG. 3 is a longitudinal cross-sectional view schematically showing the configuration of the plating module 400 in this embodiment. As shown in FIG. 3, the plating module 400 includes a plating tank 410 for containing a plating solution. The plating tank 410 is a container having a cylindrical side wall and a circular bottom wall, and a circular opening is formed at the top. The plating module 400 also includes an overflow tank 405 located outside the top opening of the plating tank 410. The overflow tank 405 is a container for receiving plating solution that overflows from the top opening of the plating tank 410.

[0020] The plating module 400 includes a membrane 420 that vertically separates the interior of a plating tank 410. The interior of the plating tank 410 is divided by the membrane 420 into a cathode region 422 and an anode region 424. The cathode region 422 and the anode region 424 are each filled with plating solution. An anode 430 is provided on the bottom surface of the plating tank 410 in the anode region 424. A resistor 450 is disposed in the cathode region 422 facing the membrane 420. The resistor 450 is a member for achieving uniform plating on the plating surface Wf-a of the disk-shaped substrate Wf, and is composed of a plate-like member with a large number of holes formed therein.

[0021] The plating module 400 also includes a substrate holder 440 for holding the substrate Wf with the plating surface Wf-a facing downward. The plating module 400 also includes a lifting mechanism 442 for raising and lowering the substrate holder 440. The lifting mechanism 442 can be realized by a known mechanism such as a motor. The plating module 400 also includes a rotation mechanism 446 for rotating the substrate holder 440 so that the substrate Wf rotates around a virtual rotation axis extending vertically through the center of the plating surface Wf-a. The rotation mechanism 446 can be realized by a known mechanism such as a motor.

[0022] The plating module 400 is configured to perform plating processing on the plating surface Wf-a of the substrate Wf by immersing the substrate Wf in the plating solution in the cathode region 422 using the lifting mechanism 442 and rotating the substrate Wf using the rotation mechanism 446 while applying a voltage between the anode 430 and the substrate Wf.

[0023] The plating module 400 also includes a tilting mechanism 447 configured to tilt the substrate holder 440. The tilting mechanism 447 can be realized by a known mechanism such as a tilting mechanism.

[0024] The plating module 400 includes a cleaning device 470 for cleaning the substrate Wf held by the substrate holder 440 and the substrate holder 440. The cleaning device 470 will be described below.

[0025] 3, the cleaning device 470 includes a cleaning member 472 for cleaning the plating surface Wf-a of the substrate Wf held by the substrate holder 440 and the internal region of the substrate holder 440. The cleaning member 472 includes a plurality of (two in this embodiment) cleaning nozzles 472a. A cleaning liquid (e.g., pure water) is supplied to the cleaning member 472 from a liquid source (not shown), and the cleaning liquid is discharged from the cleaning nozzles 472a.

[0026] The cleaning device 470 includes a drive mechanism 476 configured to rotate an arm 474. The drive mechanism 476 can be realized by a known mechanism such as a motor. The arm 474 is a plate-shaped member extending horizontally from the drive mechanism 476. The cleaning member 472 is held on the arm 474. The drive mechanism 476 is configured to rotate the arm 474 to move the cleaning member 472 between a cleaning position between the plating tank 410 and the substrate holder 440 and a retracted position where the cleaning member 472 is retracted from between the plating tank 410 and the substrate holder 440.

[0027] 3, the cleaning device 470 includes a tray member 478 disposed below the cleaning member 472. The tray member 478 is a container configured to receive the cleaning liquid that is discharged from the cleaning member 472 and drops after cleaning the plating surface Wf-a of the substrate Wf and the internal region of the substrate holder 440. In this embodiment, the cleaning member 472 and the arm 474 are entirely housed in the tray member 478. The drive mechanism 476 is configured to rotate the cleaning member 472, the arm 474, and the tray member 478 together between a cleaning position and a retracted position.

[0028] 4A and 4B are enlarged longitudinal cross-sectional views schematically illustrating a portion of the plating module of this embodiment. As shown in Fig. 4A and 4B, the substrate holder 440 includes a support mechanism 494 for supporting the outer periphery of the surface to be plated of the substrate, and a back plate assembly 492 for clamping the substrate together with the support mechanism 494.

[0029] The support mechanism 494 includes an annular support member 494-1 for supporting the outer periphery of the surface to be plated of the substrate. The support member 494-1 has a flange 494-1a that protrudes from the outer periphery of the lower surface of the back plate assembly 492. An annular seal member 494-2 is disposed on top of the flange 494-1a. The seal member 494-2 is an elastic member. The support member 494-1 supports the outer periphery of the surface to be plated of the substrate via the seal member 494-2. By sandwiching the substrate between the seal member 494-2 and the back plate assembly 492, a seal is formed between the support member 494-1 (substrate holder 440) and the substrate.

[0030] The support mechanism 494 includes an annular pedestal 494-3 attached to the inner circumferential surface of the support member 494-1. The pedestal 494-3 is a conductive member such as stainless steel. The support mechanism 494 includes a contact member 494-4 for supplying power to the substrate. The contact member 494-4 is attached in an annular shape to the inner circumferential surface of the pedestal 494-3 with screws or the like. The support member 494-1 holds the contact member 494-4 via the pedestal 494-3. The contact member 494-4 is a conductive member for supplying power to the substrate held by the substrate holder 440.

[0031] The substrate holder 440 includes an electrode member 494-6 disposed near the contact member 494-4. The electrode member 494-6 is an annular member that is conductive. The substrate holder 440 also includes an annular spacer 494-5 disposed between the contact member 494-4 and the electrode member 494-6. The spacer 494-5 is an insulator. By disposing the spacer 494-5, the contact member 494-4 and the electrode member 494-6 are insulated from each other.

[0032] The cleaning nozzle 472a is configured to eject the cleaning liquid toward the internal region of the substrate holder 440 in which the contact member 494-4 is disposed. As shown in Figures 4A and 4B, for example, the cleaning nozzle 472a may be configured to eject the cleaning liquid toward the internal region at the lower end of the substrate holder 440 that is rotated by the rotation mechanism 446 and tilted by the tilt mechanism 447. Furthermore, for example, the cleaning nozzle 472a may be configured to eject the cleaning liquid toward the lower surface of the backplate assembly 492 and to direct the cleaning liquid that hits the lower surface of the backplate assembly 492 and rebounds toward the internal region of the substrate holder 440.

[0033] The plating module 400 includes a power supply 495 configured to apply a voltage between the contact member 494-4 and the electrode member 494-6, and an ammeter 496 configured to measure a current flowing between the contact member 494-4 and the electrode member 494-6. The plating module 400 also includes a control unit 499 that operates a detector 497 configured to detect the cleanliness of the internal region of the substrate holder 440 based on the current measured by the ammeter 496 when the internal region (contact member 494-4 and seal member 494-2) of the substrate holder 440 is cleaned using the cleaning member 472. The control unit 499 can be configured, for example, as a general computer or a dedicated computer equipped with an input / output interface with an operator. Detection of the cleanliness of the internal region of the substrate holder 440 by the detector 497 and the control unit 499 will be described below.

[0034] 5 is a diagram showing the current of the electrode member when the internal region of the substrate holder is cleaned. In FIG. 5, the horizontal axis represents the passage of time, and the vertical axis represents the current measured by the ammeter 496. FIG. 5 also shows the current when the internal region of the substrate holder 440 is cleaned four times.

[0035] When a plating process is performed while the substrate Wf is held on the substrate holder 440, plating solution may leak into the internal region of the substrate holder 440 through gaps in the seal member 494-2. In this case, due to the influence of the plating solution, the current value measured by the ammeter 496 increases, as shown in the current value during the first cleaning in Figure 5, and the current value measured by the ammeter 496 decreases as the cleaning progresses. By operating the detector 497, the control unit 499 can detect, based on the current measured by the ammeter 496, how much plating solution is contained in the cleaning solution in the internal region of the substrate holder 440, i.e., how far the cleaning process has progressed.

[0036] When the current measured by the ammeter 496 becomes smaller than a predetermined threshold, the control unit 499 determines that the internal region of the substrate holder 440 has been sufficiently cleaned and can terminate the cleaning process. On the other hand, if the current measured by the ammeter 496 does not become smaller than the predetermined threshold after performing the cleaning process a predetermined number of times, the control unit 499 can issue an alarm since it is considered that some kind of malfunction has occurred. According to this embodiment, the cleanliness of the inside of the substrate holder 440 can be monitored during cleaning, thereby reducing the accumulation of contamination due to residual cleaning and its impact on plating quality.

[0037] According to this embodiment, it is possible to improve the accuracy of detecting the cleanliness of the substrate holder 440. That is, in the conventional technology, the cleanliness of the substrate holder is detected by measuring the electrical conductivity of the cleaning liquid flowing through the tray member 478. However, the cleaning liquid flowing through the tray member 478 may contain some of the cleaning liquid used to clean the substrates before cleaning the substrate holder, which may impair the accuracy of detecting the cleanliness of the substrate holder. In addition, because the cleaning liquid flowing through the tray member 478 is the liquid that has been flowing for a predetermined time since the substrate holder was cleaned, the conventional technology may not be able to accurately detect the current cleanliness of the substrate holder.

[0038] In contrast, according to this embodiment, the cleanliness of the substrate holder 440 is detected using the electrode member 494-6 arranged in the internal region of the substrate holder 440, so there is no contamination with the cleaning liquid used when cleaning the substrate, and as a result, it is possible to improve the accuracy of detecting the cleanliness of the substrate holder 440. Furthermore, according to this embodiment, the cleanliness of the substrate holder 440 is detected using the electrode member 494-6 arranged in the internal region of the substrate holder 440, so it is possible to detect the cleanliness of the substrate holder 440 without a time lag, and as a result, it is possible to improve the accuracy of detecting the cleanliness of the substrate holder 440.

[0039] As shown in Figures 4A and 4B, the plating module 400 includes a relay member 498 configured to reverse the polarity of the voltage supplied from the power supply 495 to the contact member 494-4 and the electrode member 494-6. The relay member 498 can reverse the polarity of the voltage between the contact member 494-4 and the electrode member 494-6 by switching the connection between the line connected to the contact member 494-4 and the line connected to the electrode member 494-6 to the positive and negative poles of the power supply 495. Figure 4A shows a state in which a positive voltage is applied to the electrode member 494-6 and a negative voltage is applied to the contact member 494-4. Figure 4B shows a state in which a negative voltage is applied to the electrode member 494-6 and a positive voltage is applied to the contact member 494-4.

[0040] By using the relay member 498 to reverse the polarity of the voltage supplied from the power supply 495, the plating film formed on the contact member 494-4 can be removed, thereby preventing the plating film from oxidizing over time and resulting in poor contact. That is, if the inside of the substrate holder 440 is contaminated due to leakage from the seal member 494-2 or the like during the plating process, there is a concern that plating may deposit on the contact member 494-4. In this regard, by using the relay member 498 to reverse the polarity of the power supply when cleaning the internal region of the substrate holder 440, as in this embodiment, the plating on the surface of the contact member 494-4 can be removed. Furthermore, by alternately switching the polarity of the voltage supplied to the contact member 494-4 and the electrode member 494-6 between positive and negative while performing the cleaning process, the contact member 494-4 and the electrode member 494-6 can be cleaned.

[0041] In the above description, the control unit 499 detects the cleanliness of the internal region of the substrate holder 440 based on the current measured by the ammeter 496 by operating the detector 497, but the present invention is not limited to this. The control unit 499 may also be configured to detect the presence or absence of foreign matter in the internal region of the substrate holder 440 based on the current measured by the ammeter 496 when a substrate before plating processing is attached to the substrate holder 440 by operating the detector 497. This point will be described below.

[0042] 6A and 6B are diagrams showing the voltage and current of the electrode member when the substrate before plating is attached to the substrate holder. In Fig. 6A, the horizontal axis represents the passage of time, and the vertical axis represents the voltage and current of the electrode member. Fig. 6B is an enlarged view of the area surrounded by the dashed line in Fig. 6A.

[0043] 6( a) and 6(b), if foreign matter (e.g., plating solution) is present in the internal region of the substrate holder 440, the current measured by the ammeter 496 will rise sharply when the substrate is attached to the substrate holder 440. The control unit 499 can operate the detector 497 to issue an alarm when the current measured by the ammeter 496 exceeds a predetermined threshold, indicating that foreign matter has been present in the internal region of the substrate holder 440. The control unit 499 can also operate the detector 497 to lower the voltage applied to the electrode member 494-6 in order to prevent plating from adhering to the contact member 494-4 when the current measured by the ammeter 496 exceeds a predetermined threshold.

[0044] Next, the substrate processing method of this embodiment will be described. Figure 7 is a diagram showing an outline of the substrate processing flow of this embodiment. As shown in Figure 7, the substrate processing method includes attaching the substrate Wf to the substrate holder 440 (Figure 7(a)), then plating the substrate (Figure 7(b)), and then cleaning the plated surface of the substrate Wf after plating (Figure 7(c)). Next, the substrate processing method includes removing the substrate Wf from the substrate holder 440 (Figure 7(d)), and cleaning the substrate holder 440 (Figure 7(e)).

[0045] 8 is a flow chart showing in detail the flow of substrate processing according to this embodiment. As shown in FIG. 8, the substrate processing method applies a voltage between the electrode member 494-6 and the contact member 494-4 (application step S101). Subsequently, the substrate processing method measures the current flowing between the contact member 494-4 and the electrode member 494-6 due to the application step S101 (measurement step S102). Subsequently, the substrate processing method attaches the substrate Wf to the substrate holder 440 (S103).

[0046] Next, the substrate processing method operates the detector 497 to detect whether or not a foreign object has entered the internal region of the substrate holder 440 based on the current measured in the measuring step S102 while performing step S103 (foreign object detection step S104). The foreign object detection step S104 can be performed using the control unit 499. If the current measured in the measuring step S102 is greater than a predetermined threshold, the substrate processing method can issue an alarm, indicating that a foreign object has entered the internal region of the substrate holder 440.

[0047] Next, in the substrate processing method, the substrate holder 440 is lowered to immerse the substrate Wf in a plating solution, and a plating process is performed on the substrate Wf (plating step S105). After the plating process is completed, the substrate holder 440 is raised, and the surface to be plated of the substrate Wf is cleaned using the cleaning member 472 (substrate cleaning step S106).

[0048] Next, in the substrate processing method, the substrate Wf is removed from the substrate holder 440 (step S107). Next, in the substrate processing method, the substrate holder 440 is tilted using the tilting mechanism 447 (tilting step S108). Next, in the substrate processing method, the substrate holder 440 is rotated using the rotation mechanism 446 (rotation step S109). Note that the tilting step S108 and the rotation step S109 may be performed when the substrate cleaning step S106 is performed.

[0049] Next, in the substrate processing method, a voltage is applied between the electrode member 494-6 and the contact member 494-4 (application step S110), and the current flowing between the contact member 494-4 and the electrode member 494-6 due to the application step S110 is measured (measurement step S111).

[0050] Next, in the substrate processing method, the substrate holder 440 is rotated in the rotation step S109 and tilted in the tilt step S108, and the cleaning liquid is discharged to the inner region of the lower end of the substrate holder 440 (cleaning step S112).

[0051] Next, the substrate processing method operates the detector 497 to detect the cleanliness of the internal region of the substrate holder 440 based on the current measured in the measuring step S111 while the cleaning step S112 is being performed (cleanliness detection step S113). The cleanliness detection step S113 can be performed using the control unit 499. According to the substrate processing method of this embodiment, the cleanliness of the substrate holder 440 is detected using the electrode member 494-6 arranged in the internal region of the substrate holder 440, thereby improving the accuracy of detecting the cleanliness of the substrate holder 440. In the substrate processing method, if the current measured in the measuring step S111 after performing cleaning processes a predetermined number of times is not smaller than a predetermined threshold, it is assumed that some kind of malfunction has occurred, and therefore an alarm can be issued.

[0052] Next, in the substrate processing method, while performing the cleaning step S112, the voltage supplied to the contact member 494-4 and the electrode member 494-6 is reversed in polarity in the application step S110 (switching step S114). As in this embodiment, by reversing the polarity of the power supply using the relay member 498 during cleaning, it is possible to strip the plating from the surface of the contact member 494-4. Furthermore, by alternately switching the polarity of the voltage supplied to the contact member 494-4 and the electrode member 494-6 between positive and negative while performing the cleaning process, it is possible to clean the contact member 494-4 and the electrode member 494-6.

[0053] The cleaning nozzle 472a may be configured to supply multiple types of cleaning liquids. For example, it may be possible to supply a liquid (such as pure water) that removes contaminants from the substrate holder 440 and reduces its electrical conductivity, as well as a chemical liquid (stripping liquid) that promotes the removal of the plating film from the surface of the contact member 494-4. If pure water is supplied into the substrate holder 440 during the switching step S114, the electrical conductivity of the liquid (internal liquid) accumulated inside the substrate holder 440 may become too low, resulting in insufficient current flow between the contact member 494-4 and the electrode member 494-6 and a decrease in the solubility of metal ions. This may prevent sufficient removal of the plating film if a large amount of plating has deposited on the surface of the contact member 494-4. Supplying a stripping liquid that increases the electrical conductivity and solubility of metal ions in the internal liquid during the switching step S114 allows the plating film on the surface of the contact member 494-4 to be efficiently stripped. The stripping solution used in this process can be a dilute solution of an acid or complexing agent capable of dissolving the oxide of the plating metal. The type of acid or complexing agent used is preferably selected from the main components of the plating solution to reduce the risk of contamination due to mixing of the cleaning solution with the plating solution. For example, in the case of a copper sulfate plating solution, it is preferable to use dilute sulfuric acid as the stripping solution. After the plating film has been sufficiently stripped, the switching step S114 is stopped, the cleaning solution is switched to pure water, and the series of steps from the application step S110 to the detection step S113 are repeated to expel the stripping solution supplied to the substrate holder 440.

[0054] Although several embodiments of the present invention have been described above, the above-described embodiments of the present invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention naturally includes equivalents thereof. Furthermore, any combination or omission of the components described in the claims and specification is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects.

[0055] In one embodiment, the present application discloses a plating apparatus including: a plating tank configured to contain a plating solution; a substrate holder configured to hold a substrate with its surface to be plated facing downward, the substrate holder having a contact member for supplying power to the substrate and an electrode member arranged near the contact member; a cleaning member having a cleaning nozzle configured to discharge a cleaning solution into an internal region of the substrate holder in which the contact member is arranged; a power source configured to apply a voltage between the contact member and the electrode member; an ammeter configured to measure a current flowing between the contact member and the electrode member; and a control unit that operates a detector configured to detect the cleanliness of the internal region of the substrate holder based on the current measured by the ammeter when the internal region of the substrate holder is cleaned using the cleaning member.

[0056] Furthermore, the present application discloses, as one embodiment, a plating apparatus further including a relay member configured to reverse the polarity of the voltage supplied from the power source to the contact member and the electrode member.

[0057] In addition, as one embodiment, the present application discloses a plating apparatus in which the control unit further operates the detector to detect whether or not foreign matter has entered the internal region of the substrate holder based on the current measured by the ammeter when a substrate before plating processing is attached to the substrate holder.

[0058] In addition, as one embodiment, the present application discloses a plating apparatus further including a tilting mechanism configured to tilt the substrate holder and a rotation mechanism configured to rotate the substrate holder, wherein the cleaning member is configured to be rotated by the rotation mechanism and to eject a cleaning liquid into an internal region of the lower end of the substrate holder tilted by the tilting mechanism.

[0059] Furthermore, the present application discloses, as one embodiment, a substrate processing method including the steps of: attaching a substrate to a substrate holder having contact members; plating a substrate attached to the substrate holder; removing the substrate from the substrate holder after the plating; a cleaning step of discharging a cleaning solution into an internal region of the substrate holder in which the contact members are arranged; an application step of applying a voltage between the contact members and an electrode member arranged near the contact members; a measurement step of measuring a current flowing between the contact members and the electrode member by the application step; and a cleanliness detection step of operating a detector configured to detect the cleanliness of the internal region of the substrate holder based on the current measured by the measurement step while the cleaning step is being performed.

[0060] Furthermore, the present application discloses, as one embodiment, a substrate processing method further including a switching step of reversing the positive and negative of the voltage supplied to the contact member and the electrode member by the applying step while the cleaning step is being performed.

[0061] In addition, as one embodiment, the present application discloses a substrate processing method in which the application step and the measurement step are also performed during a step of attaching a substrate to the substrate holder, and the method further includes a foreign matter detection step of operating the detector to detect whether or not foreign matter has entered an internal region of the substrate holder based on a current measured by the measurement step while the step of attaching a substrate to the substrate holder is being performed.

[0062] In addition, as one embodiment, the present application discloses a substrate processing method further including a tilting step of tilting the substrate holder and a rotation step of rotating the substrate holder, and the cleaning step is configured to eject a cleaning liquid onto an internal region of the lower end of the substrate holder that is rotated by the rotation step and tilted by the tilting step.

[0063] 400 Plating module 410 Plating tank 430 Anode 440 Substrate holder 446 Rotation mechanism 447 Tilting mechanism 450 Resistor 470 Cleaning device 472 Cleaning member 472a Cleaning nozzle 494-4 Contact member 494-5 Spacer 494-6 Electrode member 495 Power supply 496 Ammeter 497 Detector 498 Relay member 499 Control unit 1000 Plating device Wf Substrate Wf-a Surface to be plated

Claims

1. A plating apparatus comprising: a plating tank configured to contain a plating solution; a substrate holder configured to hold a substrate with its surface to be plated facing downward, the substrate holder having a contact member for supplying power to the substrate and an electrode member arranged in the vicinity of the contact member; a cleaning member having a cleaning nozzle configured to discharge a cleaning solution into an internal region of the substrate holder in which the contact member is arranged; a power source configured to apply a voltage between the contact member and the electrode member; an ammeter configured to measure a current flowing between the contact member and the electrode member; and a control unit that operates a detector configured to detect the cleanliness of the internal region of the substrate holder based on the current measured by the ammeter when the internal region of the substrate holder is being cleaned using the cleaning member.

2. The plating apparatus according to claim 1, further comprising a relay member configured to reverse the polarity of the voltage supplied from said power source to said contact member and said electrode member.

3. The plating apparatus of claim 2, wherein the control unit further operates the detector to detect whether or not foreign matter has entered the internal region of the substrate holder based on the current measured by the ammeter when the substrate before plating processing is attached to the substrate holder.

4. The plating apparatus according to claim 3, further comprising: a tilting mechanism configured to tilt the substrate holder; and a rotation mechanism configured to rotate the substrate holder, wherein the cleaning member is configured to be rotated by the rotation mechanism and to eject a cleaning liquid into an internal region at the lower end of the substrate holder tilted by the tilting mechanism.

5. A substrate processing method comprising: a step of attaching a substrate to a substrate holder having contact members; a plating step of performing a plating process on the substrate attached to the substrate holder; a step of removing the substrate from the substrate holder after the plating step; a cleaning step of discharging a cleaning solution into an internal region of the substrate holder in which the contact members are arranged; an application step of applying a voltage between the contact members and an electrode member arranged in the vicinity of the contact members; a measurement step of measuring a current flowing between the contact members and the electrode member by the application step; and a cleanliness detection step of operating a detector configured to detect the cleanliness of the internal region of the substrate holder based on the current measured by the measurement step while the cleaning step is being performed.

6. The substrate processing method according to claim 5, further comprising a switching step of reversing the positive and negative polarities of the voltages supplied to the contact members and the electrode members by the applying step while the cleaning step is being performed.

7. The substrate processing method according to claim 6, wherein the applying step and the measuring step are also performed during a step of attaching a substrate to the substrate holder, and the method further comprises a foreign matter detecting step of operating the detector to detect whether or not a foreign matter has entered an internal region of the substrate holder based on a current measured by the measuring step during the step of attaching a substrate to the substrate holder.

8. The substrate processing method according to claim 7, further comprising: a tilting step of tilting the substrate holder; and a rotating step of rotating the substrate holder, wherein the cleaning step is configured to eject a cleaning liquid onto an internal region of a lower end of the substrate holder that has been rotated by the rotating step and tilted by the tilting step.

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