APPARATUS FOR PLATING AND METHOD OF PLATING

Abstract

An object is to improve the uniformity of a plating film thickness in a variety of different types of apparatuses for plating that perform pulse plating. There is provided an apparatus for plating, comprising: a first plating tank configured to plate a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path connected with the first flow path and with the first plating tank and configured to supply the plating liquid to the first plating tank; a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the first plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path; and a control module configured to control the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the second flow path and the third flow path and to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path.

Claims

1. An apparatus for plating, comprising: a first plating tank configured to plate a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path connected with the first flow path and with the first plating tank and configured to supply the plating liquid to the first plating tank; a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the first plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path; and a control module configured to control the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the second flow path and the third flow path and to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path.

2. The apparatus for plating according to claim 1, wherein the first valve comprises a flow path changeover valve connected with the first flow path, the second flow path and the third flow path and configured to change over a flow passage between the second flow path and the third flow path.

3. The apparatus for plating according to claim 2, wherein the flow path changeover valve is a three-way valve.

4. The apparatus for plating according to claim 1, wherein the first valve is provided in the second flow path.

5. The apparatus for plating according to claim 1, wherein the first valve is provided in the third flow path.

6. The apparatus for plating according to claim 1, further comprising: a second valve, wherein the first valve is provided in the second flow path, the second valve is provided in the third flow path, and the first valve and the second valve are controlled by the control module to be operated at an identical timing.

7. The apparatus for plating according to claim 4, wherein the first valve comprises at least one of a flow control valve and an on-off valve.

8. The apparatus for plating according to claim 1, further comprising: a second plating tank; and a fourth flow path branched off from the second flow path toward the second plating tank, wherein the control module controls the first valve according to the timing of the reverse current pulse during plating of the substrate, so as to decrease supplies of the plating liquid to the first plating tank and to the second plating tank to be less than supplies of the plating liquid in the interval of the forward direction current or to stop the supplies of the plating liquid to the first plating tank and to the second plating tank.

9. The apparatus for plating according to claim 1, further comprising: a second plating tank; a fourth flow path branched off from the first flow path toward the second plating tank on an upstream side of a location where the third flow path is connected with the first flow path; a fifth flow path connected with the fourth flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the second plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; and a third valve configured to regulate a flow of the plating liquid between the fourth flow path and the fifth flow path, wherein the control module further controls the third valve according to the timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the fourth flow path and the fifth flow path and to decrease a supply of the plating liquid to the fourth flow path to be less than a supply of the plating liquid in the interval of the forward direction current or to stop the supply of the plating liquid to the fourth flow path.

10. The apparatus for plating according to claim 1, further comprising: a flowmeter configured to detect a flow rate of the plating liquid in the second flow path, wherein when it is determined that a timing of decreasing the flow rate of the plating liquid in the second flow path is deviated from a desired timing according to the timing of the reverse current pulse, based on the flow rate detected by the flowmeter, the control module performs feedback control of a timing of controlling the first valve, such as to reduce the deviation of the timing.

11. An apparatus for plating, comprising: a plating tank configured to plate a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path and a third flow path fluidically connected with the first flow path and with the plating tank and provided parallel to each other, wherein the second flow path has a larger inner diameter than an inner diameter of the third flow path; a first valve provided in the second flow path; a second valve provided in the third flow path; and a control module configured to control the first valve and the second valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate a flow of the plating liquid between the second flow path and the third flow path and to decrease a total flow rate of the plating liquid through the second flow path and through the third flow path to be less than a total flow rate of the plating liquid in an interval of the forward direction current.

12. The apparatus for plating according to claim 11, further comprising: one or a plurality of flowmeters configured to detect the total flow rate of the plating liquid through the second flow path and through the third flow path, wherein when it is determined that a timing of decreasing the total flow rate of the plating liquid through the second flow path and through the third flow path is deviated from a desired timing according to the timing of the reverse current pulse, based on the total flow rate detected by the one or the plurality of flowmeters, the control module performs feedback control of a timing of controlling the first valve and the second valve, such as to reduce the deviation of the timing.

13. An apparatus for plating, comprising: a plating tank; an anode placed in the plating tank; a substrate holder configured to hold a substrate such as to be opposed to the anode; a resistor placed between the substrate holder and the anode and provided with a plurality of through holes that form a flow path of a plating liquid; a lift device configured to lift up and down the substrate holder; a power source configured to apply a forward direction current and a reverse current pulse between the substrate and the anode; and a control module, wherein the plating tank is configured to supply the plating liquid to the substrate via the resistor and to supply the plating liquid along a surface of the substrate in such a manner as to shear the plating liquid supplied to the substrate via the resistor, and the control module is configured to control the lift device according to a timing of the reverse current pulse during plating of the substrate, such as to lift up the substrate holder, to expand a flow passage area of the plating liquid between the substrate and the resistor, and to weaken a flow of the plating liquid on the surface of the substrate, compared with a flow of the plating liquid in an interval of the forward direction current.

14. The apparatus for plating according to claim 13, wherein the control module obtains a height of the substrate holder, and when it is determined that a timing of increasing the height of the substrate holder is deviated from a desired timing according to the timing of the reverse current pulse, based on the obtained height of the substrate holder, the control module performs feedback control of a timing of controlling the lift device, such as to reduce the deviation of the timing.

15. A method of plating a substrate in a plating tank by application of a forward direction current and a reverse current pulse between the substrate and an anode, the method comprising: providing an apparatus for plating, which comprises: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path connected with the first flow path and with the plating tank and configured to supply the plating liquid to the plating tank; a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; and a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path; and controlling the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path.

16. A method of plating a substrate in a plating tank by application of a forward direction current and a reverse current pulse between the substrate and an anode, the method comprising: providing an apparatus for plating, which comprises: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path and a third flow path fluidically connected with the first flow path and with the plating tank and provided parallel to each other, wherein the second flow path has a larger inner diameter than an inner diameter of the third flow path; a first valve provided in the second flow path; and a second valve provided in the third flow path; and controlling the first valve and the second valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate a flow of the plating liquid between the second flow path and the third flow path and to decrease a total flow rate of the plating liquid through the second flow path and through the third flow path to be less than a total flow rate of the plating liquid in an interval of the forward direction current.

17. A method of plating a substrate in a plating tank by application of a forward direction current and a reverse current pulse between the substrate and an anode, the method comprising: providing an apparatus for plating, which comprises: a plating tank; an anode placed in the plating tank; a substrate holder configured to hold a substrate such as to be opposed to the anode; a resistor placed between the substrate holder and the anode and configured to form a flow path of a plating liquid between the resistor and the substrate; and a lift device configured to lift up and down the substrate holder, wherein the plating tank is configured to supply the plating liquid to the substrate via the resistor and to supply the plating liquid along a surface of the substrate in such a manner as to shear the plating liquid supplied to the substrate via the resistor; and controlling the lift device according to a timing of the reverse current pulse during plating of the substrate, such as to lift up the substrate holder, to expand a flow passage area of the plating liquid between the substrate and the resistor, and to weaken a flow of the plating liquid on the surface of the substrate, compared with a flow of the plating liquid in an interval of the forward direction current.

18. A storage medium configured to store therein a program that causes a computer to perform a control method of plating a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode in an apparatus for plating, the apparatus for plating comprising: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path connected with the first flow path and with the plating tank and configured to supply the plating liquid to the plating tank; a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; and a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path, wherein the program causes the computer to perform: controlling the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the second flow path and the third flow path and to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path.

19. A storage medium configured to store therein a program that causes a computer to perform a control method of plating a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode in an apparatus for plating, the apparatus for plating comprising: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path and a third flow path fluidically connected with the first flow path and with the plating tank and provided parallel to each other, wherein the second flow path has a larger inner diameter than an inner diameter of the third flow path; a first valve provided in the second flow path; and a second valve provided in the third flow path, wherein the program causes the computer to perform: controlling the first valve and the second valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate a flow of the plating liquid between the second flow path and the third flow path and to decrease a total flow rate of the plating liquid through the second flow path and through the third flow path to be less than a total flow rate of the plating liquid in an interval of the forward direction current.

20. A storage medium configured to store therein a program that causes a computer to perform a control method of plating a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode in an apparatus for plating, the apparatus for plating comprising: a plating tank; an anode placed in the plating tank; a substrate holder configured to hold a substrate such as to be opposed to the anode; a resistor placed between the substrate holder and the anode and provided with a plurality of through holes that form a flow path of a plating liquid; and a lift device configured to lift up and down the substrate holder, wherein the plating tank is configured to supply the plating liquid to the substrate via the resistor and to supply the plating liquid along a surface of the substrate in such a manner as to shear the plating liquid supplied to the substrate via the resistor, wherein the program causes the computer to perform: controlling the lift device according to a timing of the reverse current pulse during plating of the substrate, such as to lift up the substrate holder, to expand a flow passage area of the plating liquid between the substrate and the resistor, and to weaken a flow of the plating liquid on the surface of the substrate, compared with a flow of the plating liquid in an interval of the forward direction current.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0011] FIG. 1 is a perspective view illustrating the overall configuration of a plating apparatus according to one embodiment;

[0012] FIG. 2 is a plan view illustrating the overall configuration of the plating apparatus according to one embodiment;

[0013] FIG. 3 is a diagram schematically illustrating the peripheral configuration of one plating tank of a plating module according to one embodiment;

[0014] FIG. 4 is a schematic diagram illustrating a bump formed on a substrate;

[0015] FIG. 5 is a graph showing a time waveform of plating current that flows between an anode and a substrate;

[0016] FIG. 6 is a graph showing a time waveform of plating current that flows between the anode and the substrate;

[0017] FIG. 7 is a conceptual view illustrating a principle of improving the uniformity in height of a plurality of bumps;

[0018] FIG. 8 is a schematic diagram illustrating a fluid circuit for supplying a plating liquid according to one embodiment;

[0019] FIG. 9 is a time chart of control to decrease or stop the supply of the plating liquid in response to a reverse current pulse;

[0020] FIG. 10 is a time chart of control to decrease or stop the supply of the plating liquid in response to the reverse current pulse;

[0021] FIG. 11 is a schematic diagram illustrating a fluid circuit for supplying the plating liquid according to another embodiment;

[0022] FIG. 12 is a schematic diagram illustrating a fluid circuit for supplying the plating liquid according to another embodiment;

[0023] FIG. 13 is a schematic diagram illustrating a fluid circuit for supplying the plating liquid according to another embodiment;

[0024] FIG. 14 is a schematic diagram illustrating a fluid circuit for supplying the plating liquid according to another embodiment;

[0025] FIG. 15 is a schematic diagram illustrating a fluid circuit for supplying the plating liquid according to another embodiment;

[0026] FIG. 16 is a schematic diagram illustrating a fluid circuit for supplying the plating liquid according to another embodiment;

[0027] FIG. 17 is a schematic diagram illustrating a fluid circuit for supplying the plating liquid according to another embodiment;

[0028] FIG. 18 is a diagram schematically illustrating the peripheral configuration of the plating tank according to another embodiment; and

[0029] FIG. 19 is a diagram schematically illustrating the peripheral configuration of the plating tank according to another embodiment.

DESCRIPTION OF EMBODIMENTS

[0030] The following describes embodiments of the present disclosure with reference to drawings. The drawings are schematically illustrated, in order to facilitate understanding the features. The ratio of dimensions of respective components and the like in the drawings may not be equal to those in the actual state. Cartesian coordinates X-Y-Z are illustrated in some of the drawings for the purpose of reference. In the Cartesian coordinates, a Z direction corresponds to an upward direction, and a Z direction corresponds to a downward direction (direction where the gravity acts).

[0031] FIG. 1 is a perspective view illustrating the overall configuration of a plating apparatus 1000 of this embodiment. FIG. 2 is a plan view illustrating the overall configuration of the plating apparatus 1000 of this embodiment. As illustrated in FIGS. 1 and 2, a plating apparatus 1000 includes load ports 100, a transfer robot 110, aligners 120, pre-wet modules 200, pre-soak modules 300, plating modules 400, cleaning modules 500, spin rinse dryers 600, a transfer device 700, and a control module 800.

[0032] The load port 100 is a module for loading a substrate housed in a cassette, such as a FOUP, (not illustrated) to the plating apparatus 1000 and unloading the substrate from the plating apparatus 1000 to the cassette. While the four load ports 100 are arranged in the horizontal direction in this embodiment, the number of load ports 100 and arrangement of the load ports 100 are arbitrary. The transfer robot 110 is a robot for transferring the substrate that is configured to grip or release (transfer) the substrate between the load port 100, the aligner 120, the pre-wet module 200, and the spin rinse dryers 600. The transfer robot 110 and the transfer device 700 can perform delivery and receipt of the substrate via a temporary placement table (not illustrated) to grip or release (transfer) the substrate between the transfer robot 110 and the transfer device 700.

[0033] The aligner 120 is a module for adjusting a position of an orientation flat, a notch, and the like of the substrate in a predetermined direction. While the two aligners 120 are disposed to be arranged in the horizontal direction in this embodiment, the number of aligners 120 and arrangement of the aligners 120 are arbitrary. The pre-wet module 200 wets a surface to be plated of the substrate before a plating process with a process liquid, such as pure water or deaerated water, to replace air inside a pattern formed on the surface of the substrate with the process liquid. The pre-wet module 200 is configured to perform a pre-wet process to facilitate supplying the plating liquid to the inside of the pattern by replacing the process liquid inside the pattern with a plating liquid during plating. While the two pre-wet modules 200 are disposed to be arranged in the vertical direction in this embodiment, the number of pre-wet modules 200 and arrangement of the pre-wet modules 200 are arbitrary.

[0034] For example, the pre-soak module 300 is configured to remove an oxidized film having a large electrical resistance present on, a surface of a seed layer formed on the surface to be plated of the substrate before the plating process by etching with a process liquid, such as sulfuric acid and hydrochloric acid, and perform a pre-soak process that cleans or activates a surface of a plating base layer. While the two pre-soak modules 300 are disposed to be arranged in the vertical direction in this embodiment, the number of pre-soak modules 300 and arrangement of the pre-soak modules 300 are arbitrary. The plating module 400 performs the plating process on the substrate. There are two sets of the 12 plating modules 400 arranged by three in the vertical direction and by four in the horizontal direction, and the total 24 plating modules 400 are disposed in this embodiment, but the number of plating modules 400 and arrangement of the plating modules 400 are arbitrary.

[0035] The cleaning module 500 is configured to perform a cleaning process on the substrate to remove the plating liquid or the like left on the substrate after the plating process. While the two cleaning modules 500 are disposed to be arranged in the vertical direction in this embodiment, the number of cleaning modules 500 and arrangement of the cleaning modules 500 are arbitrary. The spin rinse dryer 600 is a module for rotating the substrate after the cleaning process at high speed and drying the substrate. While the two spin rinse dryers are disposed to be arranged in the vertical direction in this embodiment, the number of spin rinse dryers and arrangement of the spin rinse dryers are arbitrary. The transfer device 700 is a device for transfer the substrate between the plurality of modules inside the plating apparatus 1000. The control module 800 is configured to control the plurality of modules in the plating apparatus 1000 and can be configured of, for example, a general computer including input/output interfaces with an operator or a dedicated computer.

[0036] An example of a sequence of the plating processes by the plating apparatus 1000 will be described. First, the substrate housed in the cassette is loaded on the load port 100. Subsequently, the transfer robot 110 grips the substrate from the cassette at the load port 100 and transfers the substrate to the aligners 120. The aligner 120 adjusts the position of the orientation flat, the notch, or the like of the substrate in the predetermined direction. The transfer robot 110 grips or releases the substrate whose direction is adjusted with the aligners 120 to the pre-wet module 200.

[0037] The pre-wet module 200 performs the pre-wet process on the substrate. The transfer device 700 transfers the substrate on which the pre-wet process has been performed to the pre-soak module 300. The pre-soak module 300 performs the pre-soak process on the substrate. The transfer device 700 transfers the substrate on which the pre-soak process has been performed to the plating module 400. The plating module 400 performs the plating process on the substrate.

[0038] The transfer device 700 transfers the substrate on which the plating process has been performed to the cleaning module 500. The cleaning module 500 performs the cleaning process on the substrate. The transfer device 700 transfers the substrate on which the cleaning process has been performed to the spin rinse dryer 600. The spin rinse dryer 600 performs the drying process on the substrate. The transfer robot 110 receives the substrate from the spin rinse dryer 600 and transfers the substrate, on which the drying process is performed, to the cassette at the load port 100. Finally, the cassette housing the substrate is unloaded from the load port 100.

[0039] The configuration of the plating apparatus 1000 illustrated in FIG. 1 and FIG. 2 is only one example, and the configuration of the plating apparatus 1000 is not limited to the configuration of FIG. 1 and FIG. 2.

(Plating Module)

[0040] The following describes the plating module 400. The plurality of plating modules 400 included in the plating apparatus 1000 of the embodiment have similar configurations. Accordingly the description regards one plating module 400.

[0041] FIG. 3 is a diagram schematically illustrating the peripheral configuration of one plating tank 10 of the plating module 400 in the plating apparatus 1000 of the embodiment. The plating module 400 according to the embodiment is a cup-type/horizontal-type plating device configured to hold a substrate in an attitude in a horizontal direction and plating the substrate. The plating module 400 in the plating apparatus 1000 according to the embodiment includes a plating tank 10, a substrate holder 20 configured to hold a substrate Wf, a rotating mechanism 22 and a lift mechanism 24. The control module 800 described above includes a processor 801 and a non-transitory storage device 802. The storage device 802 stores therein programs, data and the like. In the control module 800, the processor 801 controls the operations of the plating apparatus 1000, in response to commands of the programs stored in the storage device 802.

[0042] According to this embodiment, one plating module 400 includes one plating tank 10 and one substrate holder 20. According to a modification, two plating modules 400 (plating tanks and substrate holders) may be connected with a common circulation pipe arrangement and a common reservoir tank (for example, shown in FIG. 15).

[0043] As illustrated in FIG. 3, the plating tank 10 is configured by a bottomed container having an opening on an upper side thereof. More specifically, the plating tank 10 has a bottom wall and an outer peripheral wall extended upward from an outer edge of this bottom wall and is open at an upper portion of this outer peripheral wall. The shape of the outer peripheral wall of the plating tank 10 is not specifically limited. The outer peripheral wall of this embodiment has a cylindrical shape as one example. A plating liquid is stored inside of the plating tank 10. A non-illustrated overflow tank is placed on an outer side of the outer peripheral wall of the plating tank 10, in order to store therein the plating liquid flowing over an upper end of the outer peripheral wall. The plating liquid stored in the overflow tank is returned from a discharge port (not shown) of the overflow tank to a reservoir tank 410 (shown in, for example, FIG. 8).

[0044] The plating liquid may be any liquid including an ion of a metal element to form a plating film, and its concrete examples are not specifically limited. According to the embodiment, a copper plating process is employed as one example of a plating process, and a copper sulfate solution is used as one example of the plating liquid.

[0045] According to the embodiment, the plating liquid includes a predetermined additive. This predetermined additive includes, for example, an accelerator and an inhibitor. For example, a non-ionic additive may be used as the accelerator. SPS (bis(3-sulfopropyl (disulfide)) or the like may be used as an example of this non-ionic additive.

[0046] An anode 13 is placed in an anode chamber 11 (described later) provided inside of the plating tank 10. The anode 13 is placed to be extended in the horizontal direction. A concrete type of the anode 13 is not specifically limited but may be an insoluble anode or a soluble anode. According to the embodiment, an insoluble anode is used as one example of the anode 13. A concrete type of this insoluble anode is not specifically limited but may be, for example, platinum, iridium oxide or the like.

[0047] An ion resistor (distributor) 14 is placed in a cathode chamber 12 (described later) provided inside of the plating tank 10. More specifically, the ion resistor 14 is provided at a location above a barrier membrane 40 described later in the cathode chamber 12 and below the substrate Wf. The ion resistor 14 denotes a member that is likely to serve as a resistance of ion transfer in the cathode chamber, 12 and is provided with a view to generating a uniform electric field between the anode 13 and the substrate Wf. The ion resistor 14 provided in the plating module 400 serves to achieve a uniform film thickness of a plating film (plating layer) formed on the substrate Wf.

[0048] The ion resistor 14 according to the embodiment is configured by a plate member having a plurality of through holes formed to pass through between a lower face and an upper face of the ion resistor 14. The plurality of through holes are provided in a hole formation area of the ion resistor 14 (as one example, a circular area in top view according to the embodiment). A concrete material of the ion resistor 14 is not specifically limited, but a resin, such as polyether ether ketone, is used as one example according to the embodiment.

[0049] A barrier membrane (membrane) 40 is placed inside of the plating tank 10. Inside of the plating tank 10 is partied by the barrier membrane 40 into an anode chamber 11 below the barrier membrane 40 and a cathode chamber 12 above the barrier membrane 40. The anode 13 described above is placed in the anode chamber 11, and the ion resistor 14 is placed in the cathode chamber 12. A substrate is placed in the cathode chamber 12 during a plating process of the substrate.

[0050] In the description hereof, the plating liquid supplied to the anode chamber 11 may be referred to as anode liquid, and the plating liquid supplied to the cathode chamber 12 may be referred to as cathode liquid. In some configuration of the plating tank, however, an anode chamber and a cathode chamber are not separated from each other (or are not clearly differentiated from each other), and the anode liquid and the cathode liquid may be collectively referred to as the plating liquid without any distinction.

[0051] The barrier membrane 40 denotes a membrane configured to allow an ion species (including a metal ion) included in the plating liquid to pass through the barrier membrane 40 but to suppress the additive included in the plating liquid from passing through the barrier membrane 40. For example, an ion exchange membrane may be used as this barrier membrane 40.

[0052] The barrier membrane 40 provided in the plating module 400 like the configuration of this embodiment suppresses the additive included in the cathode liquid in the cathode chamber 12 from being transferred to the anode chamber 11. This reduces the amount of consumption of the additive in the cathode chamber 12.

[0053] The barrier membrane 40 may have a cone shape (a V shape in the sectional view of FIG. 3), a disk shape extended as a whole in the horizontal direction without any slope, or any other arbitrary shape.

[0054] The substrate holder 20 is configured to hold the substrate Wf serving as a cathode in such a manner that a plating surface (lower surface) to be plated of the substrate Wf is opposed to the anode 13. The substrate holder 20 is connected with the rotating mechanism 22. The rotating mechanism 22 denotes a mechanism configured to rotate the substrate holder 20. The rotating mechanism 22 is connected with the lift mechanism 24. The lift mechanism 24 is supported by a support column 26 extended in a vertical direction. The lift mechanism 24 denotes a mechanism configured to lift up and down the substrate holder 20 and the rotating mechanism 22. The rotating mechanism 22 and the lift mechanism 24 may be configured by a known actuator, such as a motor. The operations of the rotating mechanism 22 and the lift mechanism 24 are controlled by the control module 800. The substrate Wf and the anode 13 are electrically connected with a rectifier (power source) 50. The power source 50 is a device configured to supply electricity between the substrate Wf and the anode 13 at the time of execution of a plating process. The operations of the power source 50 are controlled by the control module 800.

[0055] The plating tank 10 is provided with an anode chamber supply port (not shown) configured to supply the anode liquid (plating liquid) to the anode chamber 11 and an anode chamber discharge port (not shown) configured to discharge the anode liquid from the anode chamber 11. As one example, the anode chamber supply port may be placed in the bottom wall of the plating tank 10, and the anode chamber discharge port may be placed in the outer peripheral wall of the plating tank 10. In one example, the anode chamber discharge port may be provided at a plurality of positions of the plating tank 10.

[0056] The plating tank 10 is also provided with a cathode liquid supply port 17A, a cathode liquid supply port 17B and a cathode liquid drain port 17C. The cathode liquid supply port 17A is provided below the ion resistor 14 at one position or at a plurality of positions of the outer peripheral wall of the plating tank 10. The cathode liquid (plating liquid) supplied from the reservoir tank 410 (shown in, for example, FIG. 8) through the cathode liquid supply port 17A flows upward to pass through the plurality of through holes of the ion resistor 14 and is supplied to the surface of the substrate Wf.

[0057] The cathode liquid supply port 17B is provided in a bottom face of the outer peripheral wall of the plating tank 10 and is configured to flow through a passage inside of the outer peripheral wall and to supply the cathode liquid (plating liquid) to a flow path formed between the substrate Wf and the ion resistor 14. The cathode liquid (plating liquid) supplied from the reservoir tank 410 (shown in, for example, FIG. 8) through the cathode liquid supply port 17B to the flow path between the substrate Wf and the ion resistor 14 shears the cathode liquid (plating liquid) flowing upward through the ion resistor 14 to form a flow of the cathode liquid in the horizontal direction on the surface of the substrate Wf, and is discharged from the cathode liquid drain port 17C. A non-illustrated spacer with slot (spacer for forming the flow of the plating liquid) configured to surround the circumference of a substrate in planar view and to be opened on a cathode liquid drain port 17C-side is provided between the substrate Wf and the ion resistor 14. This spacer with slot causes the cathode liquid supplied from the cathode liquid supply port 17A to form the flow of the cathode liquid toward the cathode liquid drain port 17C over the entire surface of the substrate.

[0058] The cathode liquid drain port 17C is configured to discharge the cathode liquid from the cathode chamber 12. The cathode liquid discharged from the cathode liquid drain port 17C is returned via the overflow tank and the discharge port thereof (not shown) to the reservoir tank 410.

(Bump)

[0059] FIG. 4 is a schematic diagram illustrating a bump formed on a substrate by using the plating module 400 to plate the surface of the substrate. A thin metal seed layer 301 is formed in advance over the entire surface of the substrate, and electricity is supplied to the surface of the substrate via this seed layer 301 in a plating process. A photoresist layer 302 is formed on the seed layer 301. The photoresist layer 302 has an opening 302a at a location where a bump is to be formed. The substrate Wf with the photoresist layer 302 formed thereon is held by the substrate holder 20 and is soaked in the plating liquid kept in the plating tank 10 to be subjected to plating. In the plating process, a portion of the surface of the substrate Wf other than the opening 302a of the photoresist layer 302 is blocked off from the plating liquid by the photoresist layer 302. This configuration causes a plating film to be grown only on a bottom face of the opening 302a of the photoresist layer 302, so as to form a bump 303 on the substrate Wf. The photoresist layer 302 is removed after the plating process (as shown in a right drawing of FIG. 4).

[0060] A large number of bumps 303 are formed on the substrate Wf by using the photoresist layer 302 having a predetermined opening pattern. There may, however, be a variation in height (film thickness) BH of the bumps 303 formed in the respective openings on one identical substrate, depending on the sizes and the dimensions (opening diameters) of the openings and the density of the openings (i.e., the number of openings per unit area). There is accordingly a demand for forming a plurality of bumps 303 at a uniform height on the substrate.

(Current Waveform of Pulse Plating)

[0061] FIG. 5 is a graph showing a time waveform of plating current that is output from the power source 50 and flows between the anode 13 and the substrate Wf in the plating module 400. As shown in FIG. 5, the power source 50 outputs a forward direction current in a first time period T1. The forward direction herein represents a direction of the electric current flowing from the anode 13 toward the substrate Wf in the plating liquid. Accordingly, in the first time period T1, a metal ion included in the plating liquid is reduced on the plating surface to be plated of the substrate Wf, so that the metal deposits on the plating surface (i.e., a plating film is formed). The length of the first time period T1 may be set to a time length occupying a major part of a total time when the plating process is performed, in order to achieve a substantial growth of the plating film. In other words, a total length of a second time period T2 and a third time period T3 described later may be a negligible level, compared with the length of the first time period T1. The magnitude of the forward direction current is, for example, a fixed current value I1 over the entire first time period T1. The current value I1 of the forward direction current may, however, be controlled to vary with time.

[0062] In a second time period T2 provided in the middle of the first time period T1, the power source 50 outputs a reverse direction current, i.e., an electric current in an opposite direction to the forward direction current described above. This electric current continuously maintains a current value I2 having a different sign from that of the current value I1 during the second time period T2. The length of the second time period T2 is a time length that is significantly shorter than the time length of the first time period T1. Accordingly, the electric current in the second time period T2 is pulsed. In the description hereinafter, this electric current is referred to as reverse current pulse. For example, the length of the second time period T2, i.e., the pulse width of the reverse current pulse, may be about 0.1 second to several seconds. In the second time period T2, contrary to the reduction reaction of the metal ion in the first time period T1, part of the metal in the plating film formed on the plating surface in the first time period T1 is redissolved in the plating liquid, and the accelerator (one of the additives included in the plating liquid) adsorbed to an outermost surface of the plating film during the reduction reaction is desorbed from the surface of the plating film. The details will be described later.

[0063] The current value I2 of the reverse current pulse is preferably set to a value that enables the accelerator to be sufficiently desorbed. In the case where the current value I2 is set equal to the current value I1, the power source 50 configured to output the electric current in both the positive polarity and the negative polarity as described above may be replaced by a combination of a power source configured to output the electric current in a single polarity and a polarity inversion switch configured to invert the polarity of the output of the power source.

[0064] Furthermore, in a third time period T3 subsequent to the second time period T2, the power source 50 stops the output of electric current. More specifically, in the third time period T3, no electric current flows either in the forward direction or in the reverse direction in the plating liquid. Like the second time period T2, the length of the third time period T3 is a time length that is significantly shorter than the time length of the first time period T1 and may be, for example, about 0.1 second to several seconds. In the third time period T3, diffusion of the accelerator desorbed from the surface of the plating film proceeds in the plating liquid as described in detail later.

[0065] After the third time period T3, the power source 50 outputs the forward direction current (having the current value I1) again. The output of the forward direction current continues until termination of a predetermined plating process time, for example, until the film thickness of the plating film formed reaches a predetermined target film thickness.

[0066] As described above, in the embodiment shown in FIG. 5, the power source 50 supplies one reverse current pulse in the middle of the first time period T1 outputting the forward direction current, and stops the output of electric current for a short time period immediately after the supply of this reverse current pulse. The temporal position of the reverse current pulse (and the subsequent stop of electric current) in the entire first time period T1 is not specifically limited. It is, however, preferable to start the reverse current pulse in a former half of the entire time period when the plating process is performed, in terms of the uniformity in height of the plurality of bumps 303 formed on the substrate. It is also preferable to select the temporal position of the reverse current pulse, such as to compensate for a variation, by location, in the initial plating film thickness shown in FIG. 7 and to successfully achieve uniformization of the plating film thickness.

[0067] The supply of the revere current pulse and the stop of electric current may be repeated a multiple number of times as shown in FIG. 6.

(Principle of Improving Uniformity in Hight of Bumps)

[0068] FIG. 7 is a conceptual view illustrating a principle of improving the uniformity in height of the plurality of bumps 303 by using the plating current shown in FIG. 5 or FIG. 6. On the plating surface of the substrate, a location where the openings 302a of the photoresist layer 302 have large diameters and a location where the arrangement density of the openings 302a is low have higher formation rates of the plating film, compared with those in the other locations. This is because that the smaller diameter of the opening 302a or the higher arrangement density of the openings 302a has a more difficulty in sufficiently supplying the metal ion into the opening 302a and thereby provides a lower formation rate of the plating film. Accordingly, in a portion of the first time period T1 when the forward direction current is supplied, which is prior to the second time period T2 when the reverse current pulse is supplied, the film thickness of the plating film at a location having a large opening diameter and/or a low opening density is greater than the film thickness of the plating film at a location having a small opening diameter and/or a high opening density (as shown in stage (A) of FIG. 7).

[0069] As described above, the accelerator serving to accelerate generation of the plating film is included as one of the additives in the plating liquid. Molecules of such an accelerator are adsorbed to the surface of the plating film in a concentrated manner at a constant density, irrespective of the location, and accelerate the reduction reaction of the metal ion. In the second time period T2 when the reverse current pulse is supplied, the molecules of the accelerator are desorbed from the surface of the plating film and are diffused to inside of the openings 302a and peripheries thereof. The molecules of the accelerator are originally adsorbed on the surface of the plating film in a concentrated manner at a constant density, so that the molecules of the accelerator desorbed from the surface of the plating film have a constant local concentration inside of the individual openings 302a (as shown in stage (B) of FIG. 7).

[0070] In a location having a high opening density, however, the desorbed molecules of the accelerator are similarly present in nearby openings 302a, so that there is a small concentration gradient of the molecules of the accelerator in the neighborhood of the plurality of openings 302a. Accordingly, only a relatively small number of molecules of the accelerator are diffused far away from the openings 302, while a large number of molecules of the accelerator remain near the openings 302a. In a location having a low opening density, on the other hand, there is a little effect from the nearby openings 302a, so that there is a large concentration gradient of the molecules of the accelerator in the neighborhood of the plurality of openings 302a. Accordingly, a major portion of the molecules of the accelerator desorbed from the plating film are diffused far away, while only a small portion of the molecules of the accelerator remain near the openings 302a. As a result, in the third time period T3 when no electric current flows in the plating liquid, the neighborhood of the openings 302a in the location having the high opening density has a higher average concentration of the molecules of the accelerator than the neighborhood of the openings 302a in the location having the low opening density. This means that a difference in opening density provides a difference in average concentration of the molecules of the accelerator. A difference in dimension of the openings 302a also provides a similar difference in concentration of the molecules of the accelerator (more specifically, a large opening diameter is more likely to cause the molecules of the accelerator to be diffused to outside of the opening 302a, so that there is a low concentration of the molecules of the accelerator in the neighborhood of the opening 302a having a large diameter.)

[0071] As described above, the concentration of the molecules of the accelerator in the neighborhood of the opening 302a is varied according to the configuration of the opening 302a (i.e., the dimension and the arrangement density) where the plating film is formed. This results in varying, by location, the amount of the molecules of the accelerator that are re-adsorbed to the surface of the plating film in the opening 302a when the forward direction current is supplied again after the third time period T3. More specifically, the re-adsorbed amount of the molecules of the accelerator is relatively small in the location having the large opening diameter and/or the low opening density and is relatively large in the location having the small opening diameter and/or the high opening density (as shown in stage (C) of FIG. 7).

[0072] The desorption of the accelerator occurs homogeneously (as shown in stage (B) as described above. When the process from desorption to re-adsorption is viewed as a whole, the density (or the amount) of the molecules of the accelerator that are re-adsorbed to be present on the surface of the plating film becomes relatively low (or small) in the opening 302a placed in the location having the large opening diameter and/or the low opening density, while becoming relatively high (or large) in the opening 302a placed in the location having the small opening diameter and/or the high opening density (as shown in stage (D) of FIG. 7). Accordingly, the accelerator has the more significant effect to increase the plating rate on the surface of the plating film at the location having the small opening diameter and/or the high opening density, compared with that on the surface of the plating film at the location having the large opening diameter and/or the low opening density. This compensates for a difference in film thickness by the original location of the plating film (as shown in stage (A)). As a result, this uniformizes the film thickness of the plating film formed in the openings 302a (i.e., the bumps 303), regardless of the variation in configuration of the openings 302a (as shown in stage (E) of FIG. 7).

[0073] As clearly understood from the above description, with a view to uniformizing the height of the bumps 303, it is important to cause the molecules of the accelerator re-adsorbed after desorption to have a difference in density by location. This density difference is attributed to a difference in the degree of diffusion of the desorbed molecules of the accelerator diffused far away from the plating film in the second time period T2 and in the third time period T3, by location (more specifically, by the dimension and the arrangement density of the openings 302a) as described above. Accordingly, when the plating liquid on the surface of the substrate has a strong flow in the second time period and in the third time period, this strong flow of the plating liquid homogenizes the diffusion of the molecules of the accelerator and reduces a difference in density by the location of the molecules of the accelerator that are re-adsorbed. With a view to improving the uniformity in height of the bumps 303, it is thus preferable to weaken the flow of the plating liquid on the surface of the substrate in the third time period T3 or in both the second time period T2 and the third time period T3.

(Configuration for Improving Uniformity in Hight of Bumps)

[0074] FIG. 8 is a schematic diagram illustrating a fluid circuit for supplying the cathode liquid (plating liquid) according to one embodiment. A fluid circuit for supplying the anode liquid (plating liquid) is not specifically described herein, but a conventional configuration may be employed. The fluid circuit for supplying the anode liquid may be provided separately from the fluid circuit for supplying the cathode liquid. In another example, part of the configuration or the entire configuration may be shared by the fluid circuit for supplying the anode liquid and the fluid circuit for supplying the cathode liquid.

[0075] The fluid circuit shown in FIG. 8 includes a reservoir tank 410 configured to store therein the cathode liquid (plating liquid); a flow path 411 connected with the reservoir tank 410 and configured to discharge the cathode liquid from the reservoir tank 410; a flow path 412 connected with the flow path 411 and with a plating tank 10 and configured to supply the cathode liquid to the plating tank 10; a flow path 413 connected with the flow path 411 and configured as a bypass flow path to cause the cathode liquid discharged from the reservoir tank 410 to go around the plating tank 10 and to be returned to the reservoir tank 410; and a flow path regulating mechanism 430 configured to regulate the flow of the cathode liquid between the flow path 412 and the flow path 413. The flow path 413 may be referred to as the bypass flow path 413. The flow path 411 is provided with a pump 420 serving as a circulation pump to pressure-feed the cathode liquid stored in the reservoir tank 410. The flow path 412 is provided with a flowmeter 440 configured to detect a flow rate (i.e., a volume of the liquid passing through a flow path section per unit time) or a flow velocity (i.e., a flow rate per unit area) of the cathode liquid supplied to the plating tank 10. According to a modification, the flowmeter 440 may be provided in the flow path 413 to indirectly detect the flow rate of the cathode liquid in the flow path 412. According to a modification, the flowmeter 440 may be provided in both the flow path 412 and the flow path 413. The flow path 412 is connected with the cathode liquid supply ports 17A and 17B of the plating tank 10 to supply the cathode liquid (plating liquid) to the plating tank 10. The flow path 414 is connected with the cathode liquid drain port 17C of the plating tank 10 to discharge the cathode liquid from the plating tank 10 and return the discharged cathode liquid to the reservoir tank 410.

[0076] In the description hereof, the connection of the flow path includes direct connection between the flow paths (or between the flow path and the tank) and connection between the flow paths (or between the flow path and the tank) via another configuration (another flow path, a component or the like). Each of the flow paths may include one or a plurality of pipe arrangements.

[0077] In the illustrated example of FIG. 8, the flow path regulating mechanism 430 is a flow path changeover valve connected with the flow path 411, the flow path 412, and the flow path 413 and configured to change over the flow passage of the cathode liquid, which flows through the flow path 411 to a downstream side, between the flow path 412 and the flow path 413. The flow path changeover valve of the flow path regulating mechanism 430 may be, for example, a three-way changeover valve. The flow path changeover valve (three-way changeover valve) may be a valve configured to fully block one of the flow paths and to change over the flow to the other flow path or may be a valve configured to regulate (decrease) the flow of the liquid in one of the flow paths and to regulate (increase) the flow of the liquid in the other flow path.

[0078] The control module 800 is configured to control the flow path regulating mechanism 430 according to the timing of the reverse current pulse in the course of plating of the substrate Wf, to change over the flow of the cathode liquid (plating liquid) from the flow path 412 to the flow path 413, and to stop the supply of the cathode liquid to the flow path 412 (and to the plating tank 10) in a time period according to the timing of the reverse current pulse (according to the embodiment, in the third time period T3 or in both the second time period T2 and the third time period T3) (as shown in FIG. 9). The operation of controlling the flow path regulating mechanism according to the timing of the reverse current pulse means controlling the flow path regulating mechanism in relation to the timing of the reverse current pulse and includes the case of starting the control at a timing ahead of a start time of the reverse current pulse or at a timing behind the start time of the reverse current pulse. The same applies to the other embodiments.

[0079] The control module 800 is configured to detect the second time period T2 and the third time period T3 (including prediction of a start of these time periods), based on a current command value that is output to the power source 50. In one example, as shown in FIG. 9, the flow rate of the cathode liquid (plating liquid) supplied through the flow path 412 to the plating tank 10 is reduced to zero in the third time period T3 when the electric current is stopped, which is after the second time period T2 when the reverse current pulse is supplied. In another example, the flow rate of the cathode liquid (plating liquid) supplied to the plating tank 10 may be reduced to zero in both the second time period T2 and the third time period T3.

[0080] This configuration weakens the flow of the plating liquid on the surface of the substrate Wf in the time period according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3) and thereby suppresses the molecules of the accelerator desorbed from the surface of the plating film on the substrate Wf from being homogeneously diffused into the plating liquid. As a result, this configuration facilitates re-adsorption of the molecules of the accelerator, such as to compensate for a difference in film thickness of the plating film by location on the substrate Wf and uniformizes the film thickness of the plating film formed in the openings 302a (i.e., the height of the bumps 303), irrespective of a variation in configuration of the openings 302a.

[0081] One modification may decrease the flow rate of the cathode liquid supplied to the plating tank 10 in the time period according to the timing of the reverse current pulse (in the third time period T3 or both in the second time period T2 and in the third time period T3) to be lower than a flow rate f1 of the cathode liquid supplied to the plating tank 10 in the first time period T1. Decreasing the flow rate of the plating liquid (cathode liquid) herein includes decreasing the flow rate of the plating liquid (cathode liquid) to a value that is greater than zero or to zero. In the case where duplication of zero causes no problem, this process may be expressed as decreasing the flow rate of the plating liquid (cathode liquid) or reducing the flow rate to zero.

[0082] At the end of the time period according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3), the flow path regulating mechanism 430 is returned to the state in the first time period T1, so as to return the flow rate of the cathode liquid (plating liquid) that is supplied to the plating tank 10, to the flow rate in the first time period T1.

[0083] As shown in FIG. 10, when the timing of decreasing the flow rate of the cathode liquid supplied to the plating tank 10 is behind a desired timing (a start time of the third time period T3 or a start time of the second time period T2) as a result of the detection of the flow rate of the cathode liquid supplied to the plating tank 10 by the flowmeter 440, feedback control of the flow path regulating mechanism 430 may be performed to advance the timing of controlling the flow path regulating mechanism 430, in order to reduce or eliminate a delay of the timing when the flow rate of the cathode liquid supplied to the plating tank 10 is decreased or reduced to zero, in a time period according to a next timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3). This feedback control may be performed, for example, by the control module 800 to compare a flow rate target value of the cathode liquid with a detected value of the flow rate in the desired timing (the start time of the third time period T3 or the start time of the second time period T2) and to regulate the timing of controlling the flow path regulating mechanism 430.

[0084] In one example, in the initial state, the flow rate control by the flow path regulating mechanism 430 is performed at a start time of the time period according to the timing of the reverse current pulse (the start time of the third time period T3 or the start time of both the second time period T2 and the third time period T3). In the case where an actual variation in flow rate is delayed, the timing of the flow rate control by the flow path regulating mechanism 430 (i.e., the timing of control to decrease the flow rate of the cathode liquid supplied to the plating tank 10) may be advanced to reduce or eliminate the delay.

[0085] In the case where the timing when the flow rate of the cathode liquid supplied to the plating tank 10 starts decreasing is ahead of the desired timing (the start time of the third time period T3 or the start time of the second time period T2), on the other hand, feedback control of the flow path regulating mechanism 430 may be performed to delay the timing of controlling the flow path regulating mechanism 430, in order to reduce or eliminate a deviation of the timing when the flow rate of the cathode liquid supplied to the plating tank 10 is decreased or reduced to zero, in the time period according to the next timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3).

[0086] Another possible method of weakening or stopping the flow of the plating liquid on the surface of the substrate in the time period according to the timing of the reverse current pulse may stop the circulation pump (the pump 420). The ON-OFF operation of the circulation pump, however, has a poor response to change the flow rate of the cathode liquid. The operation of the circulation pump is thus likely to have a difficulty in weakening or stopping the flow of the plating liquid on the surface of the substrate for a predetermined time period (0.1 second to several seconds) in synchronism with the timing of the reverse current pulse I2. The configuration of the embodiment accordingly provides the bypass flow path 413 that goes around the plating tank 10 to regulate the flow rate of the plating liquid supplied to the plating tank 10, in synchronism with the timing of the reverse current pulse I2, as described above.

Another Embodiment 1

[0087] FIG. 11 is a schematic diagram illustrating a fluid circuit for supplying the cathode liquid (plating liquid) according to another embodiment. The configuration of the above embodiment (shown in FIG. 8) causes the cathode liquid flowing into the flow path 413 to be returned to the reservoir tank 410. As shown in FIG. 11, however, the configuration of this another embodiment may connect a downstream side of the flow path 413 with a discharge port of the plating module 400 (not shown, hereinafter may also be referred to as plating module discharge port), so as not to return the cathode liquid flowing into the flow path 413, to the reservoir tank 410 but to discharge this cathode liquid from the discharge port of the plating module 400. The configuration of this another embodiment is otherwise similar to the configuration of the above embodiment shown in FIG. 8 and is thus not described in detail here. This modified configuration has similar functions and advantageous effects to those of the embodiment described above. In subsequent embodiments described below, the bypass flow path 413 may be connected with the plating module discharge port.

Another Embodiment 2

[0088] FIG. 12 is a schematic diagram illustrating a fluid circuit for supplying the cathode liquid (plating liquid) according to another embodiment. As shown in FIG. 12, the configuration of this another embodiment may provide the flow path regulating mechanism 430 on the flow path 412 to perform the regulation such as to decrease the flow rate of the cathode liquid supplied to the plating tank 10 or to reduce the flow rate to zero, in the time period according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3). In the configuration of this another embodiment, the flow path regulating mechanism 430 may be configured by a flow control valve or an on-off valve. The flow control valve is a valve configured to regulate the flow rate to zero or to a value other than zero. The cathode liquid flows through the bypass flow path 413 by an amount corresponding to a decrease in flow rate of the cathode liquid flowing through the flow path 412 by the flow path regulating mechanism 430. This configuration enables the flow rate of the cathode liquid flowing through the flow path 412 (to the plating tank 10) to be regulated promptly and accurately. The configuration of this embodiment is otherwise similar to the configuration of the above embodiment shown in FIG. 8 and is thus not described in detail here.

Another Embodiment 3

[0089] FIG. 13 is a schematic diagram illustrating a fluid circuit for supplying the cathode liquid (plating liquid) according to another embodiment. As shown in FIG. 13, the configuration of this another embodiment may provide the flow path regulating mechanism 430 on the bypass flow path 413 to perform the regulation such as to increase the flow rate of the cathode liquid flowing through the bypass flow path 413 and to thereby indirectly decrease the flow rate of the cathode liquid supplied to the plating tank 10 via the flow path 412 or reduce the flow rate to zero, in the time period according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3). In the configuration of this another embodiment, the flow path regulating mechanism 430 may be configured by a flow control valve or an on-off valve. An amount corresponding to an increase in flow rate of the cathode liquid flowing through the flow path 413 by the flow path regulating mechanism 430 may be decreased from the flow rate of the cathode liquid flowing through the flow path 412. This configuration enables the flow rate of the cathode liquid flowing through the flow path 412 (to the plating tank 10) to be regulated promptly and accurately. The configuration of this embodiment is otherwise similar to the configuration of the above embodiment shown in FIG. 8 and is thus not described in detail here.

Another Embodiment 4

[0090] FIG. 14 is a schematic diagram illustrating a fluid circuit for supplying the cathode liquid (plating liquid) according to another embodiment. As shown in FIG. 14, the flow path regulating mechanism 430 may be configured to include a flow path regulation mechanism 431 provided in the flow path 412 and a flow path regulation mechanism 432 provided in the bypass flow path 413. More specifically, the simultaneous operations of the respective flow path regulation mechanisms 431 and 432 may change over the flow passage (reduce the flow rate of the cathode liquid flowing through the flow path 412 to zero) or may decrease the flow rate of the cathode liquid flowing through the flow path 412 (including the case of reducing the flow rate to zero).

[0091] The flow path regulation mechanism 431 may be configured by a flow control valve or an on-off valve. The flow path regulation mechanism 432 may be configured by a flow control valve or an on-off valve. The flow path regulation mechanism 431 and the flow path regulation mechanism 432 may be configured by different types of valves. In the illustrated example of FIG. 14, both the flow path regulation mechanism 431 and the flow path regulation mechanism 432 are on-off valves. The configuration of this embodiment is otherwise similar to the configuration of the above embodiment shown in FIG. 8 and is thus not described in detail here.

[0092] The cathode liquid flows through the bypass flow path 413 by an amount corresponding to a decrease in flow rate of the cathode liquid flowing through the flow path 412 by the flow path regulation mechanism 431. This configuration enables the flow rate of the cathode liquid flowing through the flow path 412 to be regulated promptly and accurately.

Another Embodiment 5

[0093] FIG. 15 is a schematic diagram illustrating a fluid circuit for supplying the cathode liquid according to another embodiment. In the configuration of this another embodiment, the cathode liquid is supplied to two plating tanks 10-1 and 10-2 via a flow path 412. As shown in FIG. 15, the flow path 412 is branched on a downstream side into a flow path 412-1 and a flow path 412-2. The flow path 412-1 is connected with the plating tank 10-1, and the flow path 412-2 is connected with the plating tank 10-2. The flow path regulating mechanism 430 may employ any of the configurations described above, although not being illustrated in FIG. 15. More specifically, the flow path regulating mechanism 430 having any of the configurations described above is provided to regulate the flow path (the flow rate) between the flow path 412 (prior to branching) and the flow path 413.

[0094] The flow path regulating mechanism 430 is controlled by the control module 800 as described above, to increase the flow rate of the cathode liquid flowing through the bypass flow path 413, such as to decrease the flow rate of the cathode liquid flowing through the flow path 412 or to reduce the flow rate to zero, in the time period according to the timing of the reverse current pulse I2 (the third time period T3 or both the second time period T2 and the third time period T3). This configuration enables the flow rates of the cathode liquid supplied to the two plating tanks 10-1 and 10-2 via the flow path 412 to be decreased or to be reduced to zero in the time period according to the timing of the reverse current pulse. In the configuration of this embodiment, the bypass flow path 413 is connected with the flow path 411 (and the flow path 412) prior to branching of the flow path 412 toward the respective plating tanks 10-1 and 10-2. This configuration thus enables the flow rates of the cathode liquid supplied to the plating tanks 10-1 and 10-2 to be simultaneously controlled by one common bypass flow path 413. This configuration is suitable for the case of pulse plating that varies the electric current at the same timing in the two plating tanks 10-1 and 10-2.

[0095] The flowmeter 440 may be provided in each of the flow path 412-1 and the flow path 412-2 as shown in FIG. 15. In another example, the flowmeter 440 may be provided in the flow path 412 prior to the branching, and each half of the flow rate detected by the flowmeter 440 may be specified as a flow rate to be supplied to each of the plating tanks 10.

[0096] The configuration of FIG. 15 may be applied to three or more plating tanks.

Another Embodiment 6

[0097] FIG. 16 is a schematic diagram illustrating a fluid circuit for supplying the cathode liquid according to another embodiment. In the configuration of this another embodiment, the flow path 411 is branched into a flow path 411-1 and a flow path 411-2. The flow path 411-1 is branched into a flow path 412-1 and a flow path (bypass flow path) 413-1. The flow path 412-1 is connected with a plating tank 10-1, and the flow path 413-1 is configured to return the cathode liquid to the reservoir tank 410 or to discharge the cathode liquid to a discharge port of the plating module 400. Similarly, the flow path 411-2 is branched into a flow path 412-2 and a flow path (bypass flow path) 413-2. The flow path 412-2 is connected with a plating tank 10-2, and the flow path 413-2 is configured to return the cathode liquid to the reservoir tank 410 or to discharge the cathode liquid to the discharge port of the plating module 400.

[0098] The flow path regulating mechanism 430 having any of the configurations described above may be used to perform flow path regulation between the bypass flow path 413-1 and the flow path 412-1 connected with the plating tank 10-1 and to perform flow path regulation between the bypass flow path 413-2 and the flow path 412-2 connected with the plating tank 10-2. In this case, the flow path regulating mechanism 430 may be placed in the flow path 411-1, the flow path 412-1 and/or the flow path 413-1, on the assumption that the flow path 412-1 and the bypass flow path 413-1 are respectively equivalent to the flow path 412 and the bypass flow path 413 in the embodiment described above. Similarly, the flow path regulating mechanism 430 may be placed in the flow path 411-2, the flow path 412-2 and/or the flow path 413-2, on the assumption that the flow path 412-2 and the bypass flow path 413-2 are respectively equivalent to the flow path 412 and the bypass flow path 413 in the embodiment described above.

[0099] In the configuration of this another embodiment, the flow path regulating mechanism 430 having any of the configurations described above may be used to be controlled by the control module 800 as described above, to increase the flow rate of the cathode liquid flowing through the bypass flow path 413-1, such as to decrease the flow rate of the cathode liquid flowing through the flow path 412-1 (i.e., the flow rate of the cathode liquid supplied to the plating tank 10-1) or to reduce the flow rate to zero, in the time period according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3). Similarly, the flow path regulating mechanism 430 having any of the configurations described above may be used to be controlled by the control module 800 as described above, to increase the flow rate of the cathode liquid flowing through the bypass flow path 413-2, such as to decrease the flow rate of the cathode liquid flowing through the flow path 412-2 (i.e., the flow rate of the cathode liquid supplied to the plating tank 10-2) or to reduce the flow rate to zero, in the time period according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3).

[0100] In the configuration of this another embodiment, the bypass flow paths 413-1 and 413-2 are connected after the branching of the flow path 411 toward the respective plating tanks 10-1 and 10-2. Even in the case where there is a difference in timing of the reverse current pulse between the respective plating tanks 10-1 and 10-2, this configuration enables the flow rates of the cathode liquid supplied to the respective plating tanks 10-1 and 10-2 to be individually controlled according to the timings of the reverse current pulses in the respective plating tanks 10-1 and 10-2. The flow rates of the cathode liquid supplied to the respective plating tanks 10-1 and 10-2 are detected by a flowmeter 440-1 and by a flowmeter 440-2. The flowmeter 440-1 may be provided in the flow path 412-1 and/or in the flow path 413-1. The flowmeter 440-2 may be provided in the flow path 412-2 and/or in the flow path 413-1.

[0101] The configuration of FIG. 17 may be applied to three or more plating tanks. In this case, the downstream configuration of the flow path 411 may be provided with regard to each of the plating tanks: for example, (411-1, 412-1, 413-1), (411-2, 412-2, 413-2), and so on.

Another Embodiment 7

[0102] FIG. 17 is a schematic diagram illustrating a fluid circuit for supplying the cathode liquid (plating liquid) according to another embodiment. In the configuration of this another embodiment, a flow path 411 is branched into a flow path 412a and a flow path 412b. The flow path 412a and the flow path 412b are connected with a flow path 412 on a downstream side. The flow path 412a and a flow path 412b have different flow passage areas (flow path diameters, piping diameters). A flow path regulating mechanism 430a and a flow path regulating mechanism 430b are respectively placed in the flow path 412a and in the flow path 412b. The flow path regulating mechanism 430a may be configured by a flow control valve or an on-off valve. The flow path regulating mechanism 430b may be configured by a flow control valve or an on-off valve. The flow path regulating mechanism 430a and the flow path regulating mechanism 430b may be configured by different types of valves.

[0103] In one example, both the flow path regulating mechanism 430a and the flow path regulating mechanism 430b may be on-off valves. The flow path 412a and the flow path 412b have different flow passage areas (different piping diameters). Controlling the on-off valves (the flow path regulating mechanism 430a and the flow path regulating mechanism 430b) provided on the flow path 412a and on the flow path 412b regulates which of the flow path 412a and the flow path 412b respectively having the different flow passage diameters, the cathode liquid flows through, and thereby varies the flow rate of the cathode liquid supplied to the plating tank 10. For example, in the case where a flow passage areas Sa of the flow path 412a is greater than a flow passage area Sb of the flow path 412b (Sa>Sb), the control is performed such as to supply the cathode liquid to the plating tank 10 via the flow path 412a at the time of supply of the forward direction current and to supply the cathode liquid to the plating tank 10 via the flow path 412b according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3). This configuration enables the flow rate of the cathode liquid supplied to the plating tank 10 to be decreased according to the timing of the reverse current pulse.

[0104] A modification may control the flow path regulating mechanism 430a and the flow path regulating mechanism 430b to change the ratio of the cathode liquid flowing through the flow path 412a and the cathode liquid flowing through the flow path 412b, so as to vary (decrease) the flow rate of the cathode liquid supplied to the plating tank 10. For example, in the case where the flow passage areas Sa of the flow path 412a is greater than the flow passage area Sb of the flow path 412b (Sa>Sb), the control is performed to decrease the ratio of the cathode liquid flowing through the flow path 412a and to increase the ratio of the cathode liquid flowing through the flow path 412b according to the timing of the reverse current pulse, compared with the respective ratios of the cathode liquid at the time of supply of the forward direction current (the first time period T1). This configuration enables the total flow rate of the cathode liquid (plating liquid) flowing through the flow path 412a and the flow path 412b toward the plating tank 10 to be decreased according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3), compared with the total flow rate of the cathode liquid flowing through the flow path 412a and the flow path 412b toward the plating tank 10 at the time of supply of the forward direction current (the first time period T1).

[0105] A flowmeter 440 may be provided in the flow path 412 after joining of the flow path 412a and the flow path 412b, to monitor a change in flow rate of the cathode liquid supplied to the plating tank 10 (as shown in FIG. 9 or FIG. 10). Feedback control may then be performed to regulate the timing of controlling the flow path regulating mechanism 430a and the flow path regulating mechanism 430b (i.e., the timing of control to decrease the flow rate of the cathode liquid supplied to the plating tank 10), in order to change the flow rate of the cathode liquid at a desired timing in response to the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3) (as shown in FIG. 9). The flowmeter 440 may be provided in the flow path 412a, in the flow path 412b, and/or in the flow path 412. For example, the flowmeters 440 may be provided respectively in the flow path 412a and in the flow path 412b to obtain the flow rate of the cathode liquid supplied to the plating tank 10 as a sum of detection values of the respective flowmeters.

[0106] The flow path 412 may have any configuration that allows the flow path 412a and the flow path 412b to be joined with each other. The flow path 412a and the flow path 412b may be directly connected with the cathode liquid supply ports 17A. The same applies to the cathode liquid supply port 17B.

[0107] The bypass flow path 413 described above may be provided on an upstream side of the flow paths 412a and 412b in the configuration of FIG. 17.

[0108] The configuration of FIG. 17 is also applicable to the configuration including two or more plating tanks as illustrated in FIG. 15 or FIG. 16. For example, in the configuration of FIG. 15 or in the configuration of FIG. 16, the flow path 412-1 may be branched into two flow paths like the flow path 412a and the flow path 412b of FIG. 17, and a flow path regulating mechanism may be provided in each of the branch flow paths. Similarly, the flow path 412-2 may be branched into two flow paths like the flow path 412a and the flow path 412b of FIG. 17, and a flow path regulating mechanism may be provided in each of the branch flow paths. In this case, in the configuration of FIG. 15 or in the configuration of FIG. 16, the bypass flow path 413 or the bypass flow paths 413-1 and 413-2 may be used with omission of the flow path regulating mechanism of regulating the flow rate (shown in any of FIG. 8 and FIGS. 11 to 14). In another example, in the configuration of FIG. 15 or in the configuration of FIG. 16, the bypass flow path 413 or the bypass flow paths 413-1 and 413-2 may be omitted.

Another Embodiment 8

[0109] The configuration of the fluid circuit of the embodiment (including the configurations of other embodiments 1 to 7) described above is not limited to a certain type (cup-type/horizontal type) of plating module shown in FIG. 3 but may be applied to any type of plating module including a dip-type/vertical type of plating module. FIG. 18 is a diagram schematically illustrating the peripheral configuration of the plating tank 10 of the plating module 400 according to another embodiment.

[0110] The plating tank 10 (the plating module 400) of this embodiment is a dip-type/vertical type of plating tank (plating module) configured to soak a substrate Wf held by a substrate holder 20 in an upright attitude into the plating liquid. In the plating tank 10, an anode 13 held by an anode holder 30 is placed in an upright attitude to be opposed to the substrate Wf, and a distributor 80 is placed between the substrate Wf and the anode 13. The distributor 80 includes one or a plurality of through holes pierced from an anode 13-side toward a substrate Wf-side and configured to supply the plating liquid to the substrate Wf; and one or a plurality of spray holes configured to spray the plating liquid, which is supplied from outside via a plating liquid supply port 17D, toward the substrate Wf-side. The distributor 80 is configured to receive a supply of the plating liquid via the plating liquid supply port 17D and to spray the plating liquid from one or the plurality of spray holes toward the substrate Wf-side. The distributor 80 is also configured, such that spraying the plating liquid from the spray holes of the distributor 80 toward the substrate Wf forms the flow of the plating liquid on the surface of the substrate Wf and causes the metal ion to be homogeneously supplied to the surface of the substrate. The configuration of spraying the plating liquid to the substrate Wf is, however, not limited to the configuration of FIG. 18, but any other configuration may be employed. Like the plating tank described above (shown in FIG. 3), the plating tank 10 of this embodiment is configured to supply the forward direction current I1 and the reverse current pulse I2 (shown in FIG. 9 or FIG. 10) from the power source 50 to between the substrate Wf and the anode 13, so as to perform pulse plating of the substrate Wf.

[0111] In the plating tank 10 shown in FIG. 18, the plating film thickness (the height of the bumps) may be further uniformized, irrespective of the location on the substrate Wf, by employing the above configuration of decreasing the flow rate of the plating liquid supplied to the plating tank 10 (to the distributor 80) or reducing the flow rate to zero, in the time period according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3).

Another Embodiment 9

[0112] FIG. 19 is a diagram schematically illustrating the peripheral configuration of the plating tank 10 according to another embodiment. The configuration of the embodiment described above weakens the flow of the plating liquid on the surface of the substrate by decreasing the flow rate of the plating liquid supplied to the plating tank 10 or reducing the flow rate to zero according to the timing of the reverse current pulse. The configuration of this embodiment, on the other hand, lifts up the substrate holder 20 to expand the flow passage area between the substrate Wf and the ion resistor 14, so as to weaken the flow of the plating liquid on the surface of the substrate.

[0113] More specifically, the control module 800 controls the lift mechanism 24 to lift up the substrate holder 20 in response to the reverse current pulse, such as to cause the height of the substrate holder 20 in the third time period T3 or in both the second time period T2 and the third time period T3 to be higher than the height of the substrate holder 20 at the time of supply of the forward direction current. This expands the flow passage area between the substrate Wf and the ion resistor 14 to be greater than the flow passage area at the time of supply of the forward direction current and thereby weakens the flow of the plating liquid on the surface of the substrate. This configuration accordingly performs control to make the height of the substrate holder 20 equal to a target value (i.e., a height greater than the height of the substrate holder 20 at the time of supply of the forward direction current) in the time period according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3). The height of the substrate holder 20 may be detected by, for example, sensing a drive amount of an actuator (for example, a known motor) provided to drive the lift mechanism 24. In another example, a sensor (for example, an optical sensor) of detecting the height may be provided separately to detect the height of the substrate holder 20.

[0114] In the case where the timing of changing (increasing) the detected height of the substrate holder 20 is behind a desired timing (a start time of the third time period T3 or a start time of the second time period T2), feedback control of the lift mechanism 24 may be performed to advance the timing of controlling the lift mechanism 24, in order to reduce or eliminate a delay of the timing when the height of the substrate holder 20 is changed, in a time period according to a next timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3). This feedback control may be performed, for example, by the control module 800 to compare a target height value with the detected height value of the substrate holder 20 at the desired timing (the start time of the third time period T3 or the start time of the second time period T2), and to regulate the timing of controlling the lift mechanism 24.

[0115] In the initial state, one exemplified configuration may cause the lift mechanism 24 to change the height of the substrate holder 24 in synchronism with the start time of the time period according to the timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3). When there is a delay in change of the height of the substrate holder 20, the timing of changing the height of the substrate holder 20 by the lift mechanism 24 may be advanced to reduce or eliminate the delay.

[0116] In the case where the timing of changing (increasing) the height of the substrate holder 20 is ahead of the desired timing (the start time of the third time period T3 or the start time of the second time period T2), on the other hand, feedback control of the lift mechanism 24 may be performed to delay the timing of controlling the lift mechanism 24 (i.e., the timing of control to increase the height of the substrate holder 20), in order to reduce or eliminate a deviation of the timing when the height of the substrate holder 20 is changed, in the time period according to the next timing of the reverse current pulse (the third time period T3 or both the second time period T2 and the third time period T3).

[0117] A modification may weaken the flow of the plating liquid on the surface of the substrate by combination of the configuration of decreasing the flow rate of the plating liquid supplied to the plating tank or reducing the flow rate to zero according to the timing of the reverse current pulse (including the configurations of other embodiments 1 to 8) described above with the control of lifting up the substrate holder to expand the flow passage area between the substrate and the ion resistor according to the timing of the reverse current pulse (the configuration of another embodiment 9).

Another Embodiment 10

[0118] The configuration of the embodiment (including the configurations of other embodiments 1 to 9) described above is applicable to a plating apparatus configured to plate a circular substrate, such as a wafer, a polygonal substrate, such as a rectangular substrate, or a substrate in any other arbitrary shape.

[0119] The present disclosure may be implemented by aspects described below: [0120] [1] According to one aspect, there is provided a plating apparatus, comprising: a first plating tank configured to plate a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path connected with the first flow path and with the first plating tank and configured to supply the plating liquid to the first plating tank; a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the first plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path; and a control module configured to control the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the second flow path and the third flow path and to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path.

[0121] The first valve may be provided on the first flow path or on the second flow path or may be connected with the first flow path, the second flow path, and the third flow path.

[0122] To control the first valve according to a timing of the reverse current pulse means controlling the first valve in relation to the start timing of the reverse current pulse and includes the case of starting the control at a timing ahead of the start timing of the reverse current pulse or at a timing behind the start timing of the reverse current pulse.

[0123] The apparatus for plating of this aspect regulates the flow rates of the plating liquid flowing through the second flow path and flowing through the third flow path according to the timing of the reverse current pulse, so as to decrease the flow rate of the plating liquid supplied to the plating tank (to the first plating tank) to be lower than the flow rate in the interval of the forward direction current or to reduce the flow rate to zero. This configuration promptly decreases the flow rate of the plating liquid supplied to the plating tank or reducing the flow rate to zero, in a time period according to the timing of the reverse current pulse (i.e., in a current stop time period subsequent to a reverse current pulse supply time period or in both the reverse current pulse supply time period and the current stop time period), so as to weaken the flow of the plating liquid on the surface of the substrate. This configuration accordingly suppresses molecules of an accelerator desorbed from the surface of a plating film from being diffused into the plating liquid, in the reverse current pulse supply time period and/or the current stop time period. This configuration thus enables a large number of the molecules of the accelerator to remain on the surface of the plating film and enables a larger number of the molecules of the accelerator to be re-adsorbed at the time of supply of the forward direction current, in a location having a smaller opening diameter and/or having a higher opening density of a photoresist layer and openings, compared with in a location having a larger opening diameter and/or having a lower opening density. This configuration accordingly compensates for a plating rate due to a difference in the opening dimension and/or in the opening density of the photoresist layer and the openings and uniformizes the height of bumps formed on the photoresist layer and formed in the openings, irrespective of the locations of the bumps on the substrate.

[0124] Furthermore, the configuration of this aspect regulates the flow rate between the two flow paths (between the second flow path and the third flow path) and thereby enables the flow rate of the plating liquid supplied to the plating tank (the amount of supply per unit time) to be decreased promptly. [0125] [2] According to one aspect, in the apparatus for plating, the first valve may comprise a flow path changeover valve connected with the first flow path, the second flow path and the third flow path and configured to change over a flow passage between the second flow path and the third flow path.

[0126] In the apparatus for plating of this aspect, the flow path changeover valve enables the flow rates of the plating liquid flowing through the second flow path and flowing through the third flow path to be regulated promptly. [0127] [3] According to one aspect, in the apparatus for plating, the flow path changeover valve may be a three-way valve.

[0128] The apparatus for plating of this aspect enables the flow rates of the plating liquid flowing through the second flow path and flowing through the third flow path to be regulated promptly by the simple configuration. [0129] [4] According to one aspect, in the apparatus for plating, the first valve may be provided in the second flow path.

[0130] The apparatus for plating of this aspect directly regulates the flow rate of the plating liquid flowing through the second flow path and thereby enables the flow rates of the plating liquid flowing through the second flow path and flowing through the third flow path to be regulated promptly by the simple configuration. [0131] [5] According to one aspect, in the apparatus for plating, the first valve may be provided in the third flow path.

[0132] The apparatus for plating of this aspect regulates the flow rate of the plating liquid flowing through the third flow path and thereby indirectly regulates the flow rate of the plating liquid flowing through the second flow path. This enables the flow rates of the plating liquid flowing through the second flow path and flowing through the third flow path to be regulated promptly by the simple configuration. [0133] [6] According to one aspect, the apparatus for plating may further comprise a second valve, wherein the first valve may be provided in the second flow path, the second valve may be provided in the third flow path, and the first valve and the second valve may be controlled by the control module to be operated at an identical timing.

[0134] In the apparatus for plating of this aspect, the first valve and the second valve respectively serving as the first flow path regulating mechanism and the second flow path regulating mechanisms provided in the second flow path and in the third flow path enable the flow rates of the plating liquid flowing through the second flow path and flowing through the third flow path to be more accurately regulated, even when the second flow path and the third flow path have different flow passage resistances (different piping resistances). [0135] [7] According to one aspect, in the apparatus for plating, the first valve may comprise at least one of a flow control valve and an on-off valve.

[0136] The apparatus for plating of this aspect enables the flow rates of the plating liquid flowing through the second flow path and flowing through the third flow path to be regulated promptly by the simple configuration by using either the flow control valve or the on-off valve. [0137] [8] According to one aspect, the apparatus for plating may further comprise a second plating tank; and a fourth flow path branched off from the second flow path toward the second plating tank, wherein the control module may control the first valve according to the timing of the reverse current pulse during plating of the substrate, so as to decrease supplies of the plating liquid to the first plating tank and to the second plating tank to be less than supplies of the plating liquid in the interval of the forward direction current or to stop the supplies of the plating liquid to the first plating tank and to the second plating tank.

[0138] The apparatus for plating of this aspect enables the flow rates of the plating liquid to the first plating tank and to the second plating tank to be controlled by using the common (one) third flow path serving as a bypass flow path. [0139] [9] According to one aspect, the apparatus for plating may further comprise a second plating tank; a fourth flow path branched off from the first flow path toward the second plating tank on an upstream side of a location where the third flow path is connected with the first flow path; a fifth flow path connected with the fourth flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the second plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; and a third valve configured to regulate a flow of the plating liquid between the fourth flow path and the fifth flow path, wherein the control module may further control the third valve according to the timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the fourth flow path and the fifth flow path and to decrease a supply of the plating liquid to the fourth flow path to be less than a supply of the plating liquid in the interval of the forward direction current or to stop the supply of the plating liquid to the fourth flow path.

[0140] Even in the case where there is a difference in timing of the reverse current pulse between in the first plating tank and in the second plating tank, the apparatus for plating of this aspect enables the flow rates of the plating liquid to the first plating tank and to the second plating tank to be individually controlled.

[0141] According to one aspect, the apparatus for plating may further comprise a flowmeter configured to detect a flow rate of the plating liquid in the second flow path, wherein when it is determined that a timing of decreasing the flow rate of the plating liquid in the second flow path is deviated from a desired timing according to the timing of the reverse current pulse, based on the flow rate detected by the flowmeter, the control module may perform feedback control of a timing of controlling the first valve, such as to reduce the deviation of the timing.

[0142] The apparatus for plating of this aspect enables the flow rate of the plating liquid to be changed at a more accurate timing and thereby weakens the flow of the plating liquid on the surface of the substrate. [0143] [11] According to one aspect, there is provided an apparatus for plating, comprising: a plating tank configured to plate a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path and a third flow path fluidically connected with the first flow path and with the plating tank and provided parallel to each other, wherein the second flow path has a larger inner diameter than an inner diameter of the third flow path; a first valve provided in the second flow path; a second valve provided in the third flow path; and a control module configured to control the first valve and the second valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate a flow of the plating liquid between the second flow path and the third flow path and to decrease a total flow rate of the plating liquid through the second flow path and through the third flow path to be less than a total flow rate of the plating liquid in an interval of the forward direction current.

[0144] To decrease a total flow rate of the plating liquid through the second flow path and through the third flow path to be less than a total flow rate of the plating liquid in an interval of the forward direction current includes the case of reducing the flow of the plating liquid flowing through the second flow path to zero and causing the plating liquid to flow via the third flow path.

[0145] The apparatus for plating of this aspect enables the flow of the plating liquid to be controlled between the second flow path and the third flow path having different flow passage areas according to the timing of the reverse current pulse and thereby enables the flow rate of the plating liquid to the first plating tank to be controlled promptly. [0146] [12] According to one aspect, the apparatus for plating may further comprise one or a plurality of flowmeters configured to detect the total flow rate of the plating liquid through the second flow path and through the third flow path, wherein when it is determined that a timing of decreasing the total flow rate of the plating liquid through the second flow path and through the third flow path is deviated from a desired timing according to the timing of the reverse current pulse, based on the total flow rate detected by the one or the plurality of flowmeters, the control module may perform feedback control of a timing of controlling the first valve and the second valve, such as to reduce the deviation of the timing.

[0147] The apparatus for plating of this aspect enables the flow rate of the plating liquid to be changed at a more accurate timing and thereby weakens the flow of the plating liquid on the surface of the substrate. [0148] [13] According to one aspect, there is provided an apparatus for plating, comprising: a plating tank; an anode placed in the plating tank; a substrate holder configured to hold a substrate such as to be opposed to the anode; a resistor placed between the substrate holder and the anode and provided with a plurality of through holes that form a flow path of a plating liquid; a lift device configured to lift up and down the substrate holder; a power source configured to apply a forward direction current and a reverse current pulse between the substrate and the anode; and a control module, wherein the plating tank is configured to supply the plating liquid to the substrate via the resistor and to supply the plating liquid along a surface of the substrate in such a manner as to shear the plating liquid supplied to the substrate via the resistor, and the control module is configured to control the lift device according to a timing of the reverse current pulse during plating of the substrate, such as to lift up the substrate holder, to expand a flow passage area of the plating liquid between the substrate and the resistor, and to weaken a flow of the plating liquid on the surface of the substrate, compared with a flow of the plating liquid in an interval of the forward direction current.

[0149] The apparatus for plating of this aspect enables the flow of the plating liquid on the surface of the substrate to be weakened by lifting up the substrate holder according to the timing of the reverse current pulse. [0150] [14] According to one aspect, in the apparatus for plating, the control module may obtain a height of the substrate holder, and when it is determined that a timing of increasing the height of the substrate holder is deviated from a desired timing according to the timing of the reverse current pulse, based on the obtained height of the substrate holder, the control module may perform feedback control of a timing of controlling the lift device, such as to reduce the deviation of the timing.

[0151] The apparatus for plating of this aspect enables the flow of the plating liquid on the surface of the substrate to be weakened at a more accurate timing. [0152] [15] According to one aspect, there is provided a method of plating a substrate in a plating tank by application of a forward direction current and a reverse current pulse between the substrate and an anode. The method comprises: providing an apparatus for plating, which comprises: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path connected with the first flow path and with the plating tank and configured to supply the plating liquid to the plating tank; a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; and a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path; and controlling the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path. [0153] [16] According to one aspect, there is provided a method of plating a substrate in a plating tank by application of a forward direction current and a reverse current pulse between the substrate and an anode. The method comprises: providing an apparatus for plating, which comprises: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path and a third flow path fluidically connected with the first flow path and with the plating tank and provided parallel to each other, wherein the second flow path has a larger inner diameter than an inner diameter of the third flow path; a first valve provided in the second flow path; and a second valve provided in the third flow path; and controlling the first valve and the second valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate a flow of the plating liquid between the second flow path and the third flow path and to decrease a total flow rate of the plating liquid through the second flow path and through the third flow path to be less than a total flow rate of the plating liquid in an interval of the forward direction current. [0154] [17] According to one aspect, there is provided a method of plating a substrate in a plating tank by application of a forward direction current and a reverse current pulse between the substrate and an anode. The method comprises: providing an apparatus for plating, which comprises: a plating tank; an anode placed in the plating tank; a substrate holder configured to hold a substrate such as to be opposed to the anode; a resistor placed between the substrate holder and the anode and configured to form a flow path of a plating liquid between the resistor and the substrate; and a lift device configured to lift up and down the substrate holder, wherein the plating tank is configured to supply the plating liquid to the substrate via the resistor and to supply the plating liquid along a surface of the substrate in such a manner as to shear the plating liquid supplied to the substrate via the resistor; and controlling the lift device according to a timing of the reverse current pulse during plating of the substrate, such as to lift up the substrate holder, to expand a flow passage area of the plating liquid between the substrate and the resistor, and to weaken a flow of the plating liquid on the surface of the substrate, compared with a flow of the plating liquid in an interval of the forward direction current. [0155] [18] According to one aspect, there is provided a storage medium configured to store therein a program that causes a computer to perform a control method of plating a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode in an apparatus for plating, the apparatus for plating comprising: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path connected with the first flow path and with the plating tank and configured to supply the plating liquid to the plating tank; a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; and a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path, wherein the program causes the computer to perform: controlling the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the second flow path and the third flow path and to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path. [0156] [19] According to one aspect, there is provided a storage medium configured to store therein a program that causes a computer to perform a control method of plating a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode in an apparatus for plating, the apparatus for plating comprising: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path and a third flow path fluidically connected with the first flow path and with the plating tank and provided parallel to each other, wherein the second flow path has a larger inner diameter than an inner diameter of the third flow path; a first valve provided in the second flow path; and a second valve provided in the third flow path, wherein the program causes the computer to perform: controlling the first valve and the second valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate a flow of the plating liquid between the second flow path and the third flow path and to decrease a total flow rate of the plating liquid through the second flow path and through the third flow path to be less than a total flow rate of the plating liquid in an interval of the forward direction current. [0157] [20] According to one aspect, there is provided a storage medium configured to store therein a program that causes a computer to perform a control method of plating a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode in an apparatus for plating, the apparatus for plating comprising: a plating tank; an anode placed in the plating tank; a substrate holder configured to hold a substrate such as to be opposed to the anode; a resistor placed between the substrate holder and the anode and provided with a plurality of through holes that form a flow path of a plating liquid; and a lift device configured to lift up and down the substrate holder, wherein the plating tank is configured to supply the plating liquid to the substrate via the resistor and to supply the plating liquid along a surface of the substrate in such a manner as to shear the plating liquid supplied to the substrate via the resistor, wherein the program causes the computer to perform: controlling the lift device according to a timing of the reverse current pulse during plating of the substrate, such as to lift up the substrate holder, to expand a flow passage area of the plating liquid between the substrate and the resistor, and to weaken a flow of the plating liquid on the surface of the substrate, compared with a flow of the plating liquid in an interval of the forward direction current.

[0158] Although the embodiments of the present invention have been described based on some examples, the embodiments of the invention described above are presented to facilitate understanding of the present invention, and do not limit the present invention. The present invention can be altered and improved without departing from the subject matter of the present invention, and it is needless to say that the present invention includes equivalents thereof. In addition, it is possible to arbitrarily combine or omit the embodiments and the modifications described above and it is also possible to arbitrarily combine or omit respective constituent elements described in the claims and the specification in a range where at least a part of the above-mentioned problem can be solved or a range where at least a part of the effect is exhibited.

[0159] The present application claims priority based on Japanese Patent Application No. 2024-112455 filed on Jul. 12, 2024. The entire disclosure of Japanese Patent Application No. 2024-112455 filed on Jul. 12, 2024, including the specification, claims, drawings and abstract, are incorporated herein by reference in its entirety.

[0160] The entire disclosures of Japanese Patent No. 7357824 (PTL 1), U.S. Pat. No. 8,795,480 (PTL 2), and US Patent Application Publication No. 2023/0075605 (PTL 3) including the specifications, claims, drawings and abstracts are incorporated herein by reference in its entirety.

REFERENCE SIGNS LIST

[0161] 10 plating tank [0162] 11 anode chamber [0163] 12 cathode chamber [0164] 13 anode [0165] 14 ion resistor [0166] 17A, 17B cathode liquid supply ports [0167] 17C cathode liquid drain port [0168] 17D plating liquid supply port [0169] 20 substrate holder [0170] 22 rotating mechanism [0171] 24 lift mechanism [0172] 26 support column [0173] 30 anode holder [0174] 40 barrier membrane [0175] 50 rectifier (power source) [0176] 80 distributor [0177] 400 plating module [0178] 411 flow path [0179] 412 flow path [0180] 413 bypass flow path [0181] 414 flow path [0182] 420 pump [0183] 430 flow path regulating mechanism [0184] 440 flowmeter [0185] 800 control module [0186] 801 processor [0187] 802 storage device [0188] 1000 plating apparatus [0189] Wf substrate