PLATING METHOD AND PLATING APPARATUS

Provided is a technique that allows removing gas bubbles attached to a hole of an ionically resistive element. A plating method includes: stirring a plating solution by driving a paddle arranged above the ionically resistive element in a state where an anode and the ionically resistive element are immersed in the plating solution (step S20); immersing a substrate as a cathode in the plating solution in a state where the stirring of the plating solution with the paddle is stopped (step S40); resuming the stirring of the plating solution with the paddle arranged above the ionically resistive element and below the substrate in a state where the substrate is immersed in the plating solution (step S50); and performing a plating process on the substrate by flowing electricity between the substrate and the anode in a state where the stirring of the plating solution with the paddle is resumed (step S60).

TECHNICAL FIELD

The present invention relates to a plating method and a plating apparatus.

BACKGROUND ART

Conventionally, there has been known what is called a cup type plating apparatus as a plating apparatus that allows performing a plating process on a substrate (for example, see PTL 1). Such plating apparatus includes a plating tank that accumulates a plating solution, a substrate holder that holds a substrate as a cathode, a rotation mechanism that rotates the substrate holder, and an elevating mechanism that moves up and down the substrate holder.

Furthermore, conventionally, for example, for ensuring an in-plane uniformity of film thickness of a plating film, there has been known a technique of arranging an ionically resistive element having a plurality of holes inside the plating tank (for example, see PTL 2).

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

In a case where an ionically resistive element is arranged inside the plating tank of the cup type plating apparatus as illustrated in PTL 1 described above, in a hypothetical case where a large amount of gas bubbles included in the plating solution of the plating tank are attached to the holes of the ionically resistive element, these gas bubbles attached to the holes may possibly cause a plating quality of the substrate to deteriorate.

The present invention has been made in view of the above, and one of the objects of the present invention is to provide a technique that allows removing gas bubbles attached to a hole of an ionically resistive element.

Solution to Problem

To achieve the above-described object, a plating method according to one aspect of the present invention includes: supplying a plating solution to a plating tank provided with an anode and an ionically resistive element arranged above the anode and having a plurality of holes, and immersing the anode and the ionically resistive element in the plating solution; stirring the plating solution by driving a paddle arranged above the ionically resistive element in a state where the anode and the ionically resistive element are immersed in the plating solution; immersing a substrate as a cathode in the plating solution in a state where the stirring of the plating solution with the paddle is stopped; resuming the stirring of the plating solution with the paddle arranged above the ionically resistive element and below the substrate in a state where the substrate is immersed in the plating solution; and performing a plating process on the substrate by flowing electricity between the substrate and the anode in a state where the stirring of the plating solution with the paddle is resumed.

With this aspect, for example, even in a case where gas bubbles included in the plating solution are attached to the hole of the ionically resistive element when supplying the plating solution to the plating tank, the stirring of the plating solution with the paddle can accelerate an upward movement of the gas bubbles attached to the hole. Accordingly, the gas bubbles attached to the hole of the ionically resistive element can be removed.

In addition, with this aspect, since the substrate is immersed in the plating solution in a state where the stirring of the plating solution with the paddle is stopped, waves generating on a liquid surface of the plating solution caused by the stirring of the plating solution with the paddle when immersing the substrate in the plating solution can be suppressed. Accordingly, a large amount of the gas bubbles getting attached to the substrate when the substrate is immersed in the plating solution can also be suppressed.

In addition, with this aspect, since the stirring of the plating solution with the paddle is resumed in a state where the substrate is immersed in the plating solution, the plating solution can be effectively supplied to the substrate. Accordingly, for example, a pre-wet process liquid remaining inside a wiring pattern of the substrate can be effectively replaced with the plating solution.

In addition, with this aspect, since the plating process is performed in a state where the stirring of the plating solution with the paddle is resumed, the plating solution can be effectively supplied to the substrate during the plating process. Accordingly, a plating film can be effectively formed on the substrate.

Aspect 1 described above may further include causing the plating solution to overflow from the plating tank in a state where the stirring of the plating solution with the paddle is stopped, in which the immersing of the substrate in the plating solution in a state where the stirring of the plating solution with the paddle is stopped may be performed after causing the plating solution to overflow from the plating tank.

With this aspect, gas bubbles floating above the ionically resistive element can be discharged outside the plating tank together with the plating solution that overflows from the plating tank. Accordingly, when the substrate is immersed in the plating solution, the gas bubbles getting attached to the substrate can be effectively suppressed.

Aspect 1 or 2 described above may further include: pulling the substrate out of the plating solution after a plating process is performed on the substrate; stirring the plating solution by driving the paddle arranged above the ionically resistive element in a state where the substrate is pulled out of the plating solution; immersing a second substrate in the plating solution in a state where the stirring of the plating solution with the paddle is stopped; resuming the stirring of the plating solution with the paddle arranged above the ionically resistive element and below the second substrate in a state where the second substrate is immersed in the plating solution; and performing a plating process on the second substrate by flowing electricity between the second substrate and the anode in a state where the stirring of the plating solution with the paddle is resumed.

In any one of Aspects 1 to 3 described above, the immersing of the substrate in the plating solution in a state where the stirring of the plating solution with the paddle is stopped may include immersing the substrate in the plating solution in a state where the stirring of the plating solution with the paddle is stopped and in a state where a surface to be plated of the substrate is inclined with respect to a horizontal direction.

Aspect 4 described above may further include returning the surface to be plated of the substrate in a state of being immersed in the plating solution to the horizontal direction, in which the resuming of the stirring of the plating solution with the paddle in a state where the substrate is immersed in the plating solution may be performed after returning the surface to be plated of the substrate in a state of being immersed in the plating solution to the horizontal direction.

In a hypothetical case where the stirring of the plating solution with the paddle is resumed in a state where the surface to be plated of the substrate is inclined with respect to the horizontal direction, since an upper end of the surface to be plated of the substrate in an inclined state becomes close to the liquid surface of the plating solution, when waves generate on the liquid surface of the plating solution by resuming the stirring of the plating solution with the paddle, gas bubbles may possibly easily be drawn to the surface to be plated of the substrate. In contrast to this, with this aspect, since the stirring of the plating solution with the paddle is resumed after the surface to be plated of the substrate in a state of being immersed in the plating solution is returned to the horizontal direction, even in a hypothetical case where waves generate on the liquid surface of the plating solution by resuming the stirring of the plating solution with the paddle, gas bubbles being drawn to the surface to be plated of the substrate can be effectively suppressed.

In Aspect 1 described above, a flow rate of the plating solution flowing from a lower surface side of the ionically resistive element, passing through the plurality of holes, and flowing toward an upper surface side of the ionically resistive element when stirring the plating solution by driving the paddle in a state where the anode and the ionically resistive element are immersed in the plating solution may be greater than a flow rate of the plating solution when performing a plating process on the substrate.

With this aspect, gas bubbles attached to the hole of the ionically resistive element can be effectively removed.

In any one of Aspects 1 to 6 described above, the paddle may be driven alternately in a first direction parallel to the upper surface of the ionically resistive element and a second direction opposite to the first direction to stir the plating solution.

In Aspect 7 described above, the paddle may have a honeycomb structure including a plurality of stirring members constituting a plurality of polygonal through-holes extending in an upper/lower direction, and the plurality of stirring members may include a polygonal portion having a quadrangle shape, a first projecting portion projecting in an arc-like shape from a side surface on the first direction of the polygonal portion to the first direction, and a second projecting portion projecting in an arc-like shape from a side surface on the second direction of the polygonal portion to the second direction, in a plan view.

With this aspect, since the paddle has a honeycomb structure, an arrangement density of the plurality of stirring members can be easily increased. Accordingly, since the plating solution can be effectively stirred with the paddle, gas bubbles attached to the hole of the ionically resistive element can be effectively removed.

In addition, with this aspect, since the plurality of stirring members of the paddle include the polygonal portion, the first projecting portion, and the second projecting portion, for example, compared with a case where the plurality of stirring members include the polygonal portion but do not include the first projecting portion or the second projecting portion, an area stirrable with the paddle when the paddle moves a constant distance can be easily expanded. Accordingly, since the plating solution can be effectively stirred with the paddle, the gas bubbles attached to the hole of the ionically resistive element can be effectively removed.

In Aspect 8 described above, a paddle width as a maximum value of a distance between the first projecting portion and the second projecting portion may be smaller than a substrate width as a maximum value of a distance between an outer edge in the first direction and an outer edge in the second direction of the surface to be plated of the substrate on which a plating process is performed.

With this aspect, for example, compared with a case where the paddle width is the same as the substrate width or greater than the substrate width, a moving distance in the first direction and the second direction of the paddle can be increased. Accordingly, since the plating solution can be more effectively stirred with the paddle, gas bubbles attached to the hole of the ionically resistive element can be effectively removed.

To achieve the above-described object, a plating apparatus according to one aspect of the present invention includes: a plating tank provided with an anode and an ionically resistive element arranged above the anode and having a plurality of holes; a substrate holder configured to hold a substrate as a cathode; and a paddle arranged above the ionically resistive element and below the substrate, and configured to be driven alternately in a first direction parallel to an upper surface of the ionically resistive element and a second direction opposite to the first direction to stir a plating solution accumulated in the plating tank. The paddle has a honeycomb structure including a plurality of stirring members constituting a plurality of polygonal through-holes extending in an upper/lower direction. The plurality of stirring members include a polygonal portion having a quadrangle shape, a first projecting portion projecting in an arc-like shape from a side surface on the first direction of the polygonal portion to the first direction, and a second projecting portion projecting in an arc-like shape from a side surface on the second direction of the polygonal portion to the second direction, in a plan view.

With this aspect, even in a case where gas bubbles get attached to the hole of the ionically resistive element, the stirring of the plating solution with the paddle can accelerate an upward movement of the gas bubbles attached to the hole. Accordingly, the gas bubbles attached to the hole of the ionically resistive element can be removed.

In addition, with this aspect, since the plurality of stirring members of the paddle constitute a honeycomb structure, and the plurality of stirring members of the paddle include the polygonal portion, the first projecting portion, and the second projecting portion, as described above, the plating solution can be more effectively stirred with the paddle, and the gas bubbles attached to the hole of the ionically resistive element can be effectively removed.

In Aspect 10 described above, a paddle width as a maximum value of a distance between the first projecting portion and the second projecting portion may be smaller than a substrate width as a maximum value of a distance between an outer edge in the first direction and an outer edge in the second direction of the surface to be plated of the substrate on which a plating process is performed.

DESCRIPTION OF EMBODIMENTS

Embodiments

The following describes an embodiment of the present invention with reference to the drawings. Note that the drawings are schematically illustrated to facilitate understanding of features of constituent elements, and dimensional proportions and the like of each constituent element are not necessarily the same as the actual ones. In some drawings, orthogonal coordinates of X-Y-Z are illustrated for reference. Among the orthogonal coordinates, the Z-direction corresponds to an upper side, and the −Z-direction corresponds to a lower side (the direction in which gravity acts).

FIG.1is a perspective view illustrating the overall configuration of a plating apparatus1000of this embodiment.FIG.2is a plan view (top surface view) illustrating the overall configuration of the plating apparatus1000of this embodiment. As illustrated inFIG.1andFIG.2, the plating apparatus1000includes load ports100, a transfer robot110, aligners120, pre-wet modules200, pre-soak modules300, plating modules400, cleaning modules500, spin rinse dryers600, a transfer device700, and a control module800.

The load port100is a module for loading a substrate housed in a cassette, such as a FOUP. (not illustrated) to the plating apparatus1000and unloading the substrate from the plating apparatus1000to the cassette. While the four load ports100are arranged in the horizontal direction in this embodiment, the number of load ports100and arrangement of the load ports100are arbitrary. The transfer robot110is a robot for transferring the substrate that is configured to grip or release the substrate between the load port100, the aligner120, the pre-wet module200, and the spin rinse dryers600. The transfer robot110and the transfer device700can perform delivery and receipt of the substrate via a temporary placement table (not illustrated) to grip or release the substrate between the transfer robot110and the transfer device700.

The aligner120is 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 aligners120are disposed to be arranged in the horizontal direction in this embodiment, the number of aligners120and arrangement of the aligners120are arbitrary. The pre-wet module200wets 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 module200is configured to perform a pre-wet process to facilitate supplying the plating solution to the inside of the pattern by replacing the process liquid inside the pattern with a plating solution during plating. While the two pre-wet modules200are disposed to be arranged in the upper/lower direction in this embodiment, the number of pre-wet modules200and arrangement of the pre-wet modules200are arbitrary.

For example, the pre-soak module300is 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 modules300are disposed to be arranged in the upper/lower direction in this embodiment, the number of pre-soak modules300and arrangement of the pre-soak modules300are arbitrary. The plating module400performs the plating process on the substrate. There are two sets of the12plating modules400arranged by three in the upper/lower direction and by four in the horizontal direction, and the total 24 plating modules400are disposed in this embodiment, but the number of plating modules400and arrangement of the plating modules400are arbitrary.

The cleaning module500is configured to perform a cleaning process on the substrate to remove the plating solution or the like left on the substrate after the plating process. While the two cleaning modules500are disposed to be arranged in the upper/lower direction in this embodiment, the number of cleaning modules500and arrangement of the cleaning modules500are arbitrary. The spin rinse dryer600is a module for rotating the substrate after the cleaning process at high speed and drying the substrate. While the two spin rinse dryers600are disposed to be arranged in the upper/lower direction in this embodiment, the number of spin rinse dryers600and arrangement of the spin rinse dryers600are arbitrary. The transfer device700is a device for transferring the substrate between the plurality of modules inside the plating apparatus1000. The control module800is configured to control the plurality of modules in the plating apparatus1000and can be configured of, for example, a general computer including input/output interfaces with an operator or a dedicated computer.

An example of a sequence of the plating processes by the plating apparatus1000will be described. First, the substrate housed in the cassette is loaded on the load port100. Subsequently, the transfer robot110grips the substrate from the cassette at the load port100and transfers the substrate to the aligners120. The aligner120adjusts the position of the orientation flat, the notch, or the like of the substrate in the predetermined direction. The transfer robot110grips or releases the substrate whose direction is adjusted with the aligners120to the pre-wet module200.

The pre-wet module200performs the pre-wet process on the substrate. The transfer device700transfers the substrate on which the pre-wet process has been performed to the pre-soak module300. The pre-soak module300performs the pre-soak process on the substrate. The transfer device700transfers the substrate on which the pre-soak process has been performed to the plating module400. The plating module400performs the plating process on the substrate.

The transfer device700transfers the substrate on which the plating process has been performed to the cleaning module500. The cleaning module500performs the cleaning process on the substrate. The transfer device700transfers the substrate on which the cleaning process has been performed to the spin rinse dryer600. The spin rinse dryer600performs the drying process on the substrate. The transfer robot110receives the substrate from the spin rinse dryer600and transfers the substrate, on which the drying process is performed, to the cassette at the load port100. Finally, the cassette housing the substrate is unloaded from the load port100.

Note that the configuration of the plating apparatus1000described inFIG.1andFIG.2is merely an example, and the configuration of the plating apparatus1000is not limited to the configuration inFIG.1orFIG.2.

Subsequently, the plating modules400will be described. Note that, since the plurality of plating modules400included in the plating apparatus1000according to this embodiment have the identical configuration, one of the plating modules400will be described.

FIG.3is a schematic diagram illustrating the configuration of the plating module400in the plating apparatus1000according to this embodiment. Specifically,FIG.3schematically illustrates the plating module400in a state before a substrate Wf is immersed in a plating solution Ps.FIG.4is a schematic diagram illustrating a state where the substrate Wf is immersed in the plating solution Ps. Note that, a part ofFIG.4also illustrates an enlarged view of the part A1 but the enlarged view of the part A1 omits an illustration of a paddle70described later.

The plating apparatus1000according to this embodiment is a cup type plating apparatus. The plating module400of the plating apparatus1000includes a plating tank10, an overflow tank20, a substrate holder30, and the paddle70. Furthermore, as illustrated inFIG.3, the plating module400may include a rotation mechanism40, an inclination mechanism45, and an elevating mechanism50.

The plating tank10according to this embodiment is configured of a container with a bottom having an opening in an upper side. Specifically, the plating tank10has a bottom wall10aand an outer peripheral wall10bextending upward from an outer peripheral edge of the bottom wall10a, and an upper portion of the outer peripheral wall10bis open.

Although the shape of the outer peripheral wall10bof the plating tank10is not particularly limited, the outer peripheral wall10baccording to this embodiment has a cylindrical shape as an example. In the inside of the plating tank10, a plating solution Ps is accumulated. The plating tank10is provided with a supply port13for supplying a plating solution Ps to the plating tank10.

It is only necessary for the plating solution Ps to be a solution including ions of a metallic element for constituting a plating film, and a specific example of the plating solution Ps is not particularly limited. In this embodiment, a copper plating process is used as an example of the plating process, and a copper sulfate solution is used as an example of the plating solution Ps. The plating solution Ps may include a predetermined additive.

In the inside of the plating tank10, an anode11is arranged. A specific type of the anode11is not particularly limited, and it may be an insoluble anode or may be a soluble anode. In this embodiment, an insoluble anode is used as an example of the anode11. A specific type of the insoluble anode is not particularly limited, and platinum, iridium oxide, and the like can be used.

In the inside of the plating tank10, above the anode11, an ionically resistive element12is arranged. Specifically, as illustrated inFIG.4(enlarged view of part A1), the ionically resistive element12is configured of a porous plate member having a plurality of holes12a(pores). The holes12aare disposed so as to communicate with a lower surface and a top surface of the ionically resistive element12. As illustrated inFIG.3, a region in which the plurality of holes12aare formed in the ionically resistive element12is referred to as a “hole-formed area PA.” The hole-formed area PA according to this embodiment has a circular shape in a plan view. The hole-formed area PA according to this embodiment has an area that is the same as an area of a surface to be plated Wfa of the substrate Wf or greater than the area of the surface to be plated Wfa. However, it is not limited to this configuration, and the hole-formed area PA may have an area that is smaller than the area of the surface to be plated Wfa of the substrate Wf.

The ionically resistive element12is disposed to ensure homogenization of an electric field formed between the anode11and the substrate Wf as a cathode (the reference numeral is denoted inFIG.6described below). By the ionically resistive element12being arranged in the plating tank10, as in this embodiment, the uniformization of film thickness of the plating film (plated layer) formed on the substrate Wf can be easily ensured.

The overflow tank20is configured of a container with a bottom arranged outside the plating tank10. The overflow tank20is disposed for temporarily accumulating a plating solution Ps that has exceeded an upper end of the outer periphery wall10bof the plating tank10(that is, the plating solution Ps overflowed from the plating tank10). The plating solution Ps accumulated in the overflow tank20is discharged from a discharge port14, subsequently passes through a flow passage15, and is temporarily accumulated in a reservoir tank80(seeFIG.4). The plating solution Ps accumulated in the reservoir tank80is subsequently pressure fed by a pump81(seeFIG.4), and circulated into the plating tank10again from the supply port13.

The plating module400may include a level sensor60afor detecting a position of a liquid surface of a plating solution Ps in the plating tank10. A detection result of the level sensor60ais transmitted to the control module800.

The plating module400may include a flow rate sensor60bfor detecting a flow rate (L/min) of the plating solution Ps that has overflowed from the plating tank10. A detection result of the flow rate sensor60bis transmitted to the control module800. Although a specific arrangement position of the flow rate sensor60bis not particularly limited, the flow rate sensor60baccording to this embodiment is arranged in the flow passage15communicating with the discharge port14of the overflow tank20and the reservoir tank80as an example.

The substrate holder30holds the substrate Wf as a cathode such that a surface to be plated Wfa of the substrate Wf is opposed to the anode11. In this embodiment, specifically, the surface to be plated Wfa of the substrate Wf is disposed on a surface facing a lower side (lower surface) of the substrate Wf.

As illustrated inFIG.3, the substrate holder30may include a ring31disposed so as to project below an outer peripheral edge of the surface to be plated Wfa of the substrate Wf. Specifically, the ring31according to this embodiment has a ring shape in a lower surface view.

The substrate holder30is connected to the rotation mechanism40. The rotation mechanism40is a mechanism for rotating the substrate holder30. “R1” denoted inFIG.3is an exemplary rotation direction of the substrate holder30. As the rotation mechanism40, a known rotation motor and the like can be used. The inclination mechanism45is a mechanism for inclining the rotation mechanism40and the substrate holder30. The elevating mechanism50is supported by a spindle51extending in an upper/lower direction. The elevating mechanism50is a mechanism for moving up and down the substrate holder30, the rotation mechanism40and the inclination mechanism45. As the elevating mechanism50, a known elevating mechanism, such as a linear motion type actuator, can be used.

Note that, as illustrated inFIG.12, in the inside of the plating tank10, at a position above the anode11and below the ionically resistive element12, a membrane16may be arranged. In this case, the inside of the plating tank10is partitioned by the membrane16into an anode chamber17abelow the membrane16and a cathode chamber17babove the membrane16. The anode11is arranged in the anode chamber17a, and the ionically resistive element12is arranged in the cathode chamber17b. The membrane16is configured to allow ion species including metal ions included in the plating solution Ps to pass through the membrane16, while inhibiting nonionic plating additives included in the plating solution Ps from passing through the membrane16. As the membrane16, an ion exchange membrane can be used as an example.

In a case where the inside of the plating tank10is partitioned by the membrane16into the anode chamber17aand the cathode chamber17b, the supply port13is preferred to be disposed in both the anode chamber17aand the cathode chamber17b. The anode chamber17ais preferred to be provided with a discharge port14afor discharging the plating solution Ps in the anode chamber17a.

FIG.5is a schematic plan view of the paddle70. With reference toFIG.3,FIG.4, andFIG.5, the paddle70is arranged in a position above the ionically resistive element12and below the substrate Wf. The paddle70is driven by a driving device77. By the paddle70being driven, the plating solution Ps in the plating tank10is stirred.

The paddle70according to this embodiment is, as an example, driven alternately in a “first direction (X-direction, as an example, in this embodiment)” parallel to an upper surface of the ionically resistive element12and a “second direction (−X-direction, as an example, in this embodiment)” opposite to the first direction. That is, the paddle70according to this embodiment is, for example, reciprocated in the X-axis direction. The driving operation of the paddle70is controlled by the control module800.

As illustrated inFIG.5, the paddle70according to this embodiment, as an example, includes a plurality of stirring members71aextending in a direction perpendicular to the first direction and the second direction (Y-axis direction) of the paddle70. Between adjacent stirring members71a, a clearance is provided. One ends of the plurality of stirring members71aare coupled to a coupling member72a, and other ends are coupled to a coupling member72b.

The paddle70is preferred to be configured such that a moving region MA of the paddle70(that is, a range in which the paddle70reciprocates) when stirring the plating solution Ps covers an entire hole-formed area PA of the ionically resistive element12in a plan view. With this configuration, the plating solution Ps above the hole-formed area PA of the ionically resistive element12can be effectively stirred with the paddle70.

Note that, it is only necessary that the paddle70is arranged inside the plating tank10at least when stirring the plating solution Ps, and need not be arranged inside the plating tank10constantly. For example, in a case where the driving of the paddle70is stopped and the stirring of the plating solution Ps with the paddle70is not performed, a configuration in which the paddle70is not arranged inside the plating tank10is allowed.

The control module800includes a microcomputer, which includes a CPU (Central Processing Unit)801as a processor, a storage device802as a non-transitory storage medium, and the like. By the CPU801operating as the processor based on commands of a program stored in the storage device802, the control module800controls the operation of the plating module400.

In some cases, gas bubbles Bu generate in the plating solution Ps in the plating tank10. Specifically, for example, when supplying the plating solution Ps to the plating tank10, in a case where air flows into the plating tank10together with the plating solution Ps, the air may possibly become the gas bubbles Bu.

As described above, in a case where the gas bubbles Bu generate in the plating solution Ps in the plating tank10, the gas bubbles Bu get attached to the holes12aof the ionically resistive element12in some cases. In a hypothetical case where the plating process is performed on the substrate Wf in a state where a large amount of the gas bubbles Bu are attached to the holes12a, the gas bubbles Bu may possibly cause the plating quality of the substrate Wf to deteriorate. Therefore, in this embodiment, a technique described below is used to deal with this problem.

FIG.6is an exemplary flowchart for describing a plating method according to this embodiment. The plating method according to this embodiment includes step S10to step S60. Note that, the plating method according to this embodiment may be executed automatically by the control module800. Furthermore, before step S10according to this embodiment is executed, the plating solution Ps is assumed not to be accumulated inside the plating tank10. Alternatively, even in a case where the plating solution Ps is accumulated inside the plating tank10, the liquid surface of the plating solution Ps of the plating tank10is positioned below the ionically resistive element12.

In step S10, by supplying the plating solution Ps to the plating tank10, the anode11and the ionically resistive element12are immersed in the plating solution Ps. Specifically, in this embodiment, by supplying the plating solution Ps from the supply port13to the plating tank10, the anode11and the ionically resistive element12are immersed in the plating solution Ps.

Note that, in step S10, the position of the liquid surface of the plating solution Ps may be obtained based on the detection result of the above-described level sensor60a, and the plating solution Ps may be supplied to the plating tank10until the obtained position of the liquid surface of the plating solution Ps is determined to be a predetermined position above the anode11and the ionically resistive element12.

Alternatively, in step S10, the flow rate of the plating solution Ps overflowed from the plating tank10may be obtained based on the detection result of the above-described flow rate sensor60b, and the plating solution Ps may be supplied to the plating tank10until the obtained flow rate is determined to be greater than zero. Even in this case, the liquid surface of the plating solution Ps in the plating tank10can be positioned above the anode11and the ionically resistive element12, and thereby immerse the anode11and the ionically resistive element12in the plating solution Ps.

After step S10, step S20is performed. Specifically, step S20is performed after the plating solution Ps is started to be supplied to the plating tank10according to step S10and in a case where the liquid surface of the plating solution Ps of the plating tank10is at a position where the plating solution Ps can be stirred with the paddle70(such as in a case where the liquid surface of the plating solution Ps is positioned above the paddle70).

In step S20, by driving the paddle70arranged above the ionically resistive element12and below the substrate Wf, the plating solution Ps is stirred with the paddle70. That is, in step S20, the stirring of the plating solution Ps with the paddle70is started. Specifically, in this embodiment, the plating solution Ps is stirred by driving the paddle70alternately in the first direction and the second direction.

With this embodiment, for example, even in a case where the gas bubbles Bu included in the plating solution Ps get attached to the holes12aof the ionically resistive element12when supplying the plating solution Ps to the plating tank10, by stirring the plating solution Ps with the paddle70according to step S20, an upward movement of the gas bubbles Bu can be accelerated. Accordingly, the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be removed.

Note that, the flow rate (L/min) of the plating solution Ps flowing from a lower surface side of the ionically resistive element12, passing through the plurality of holes12a, and flowing toward an upper surface side of the ionically resistive element12is preferred to be large, in that the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be effectively removed.

Therefore, for example, it is preferred to make the flow rate of the plating solution Ps flowing from the lower surface side of the ionically resistive element12, passing through the plurality of holes12a, and flowing toward the upper surface side of the ionically resistive element12in step S20greater than the flow rate of the plating solution Ps flowing from the lower surface side of the ionically resistive element12, passing through the plurality of holes12a, and flowing toward the upper surface side of the ionically resistive element12in step S60described later. With this configuration, the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be effectively removed.

Note that, for example, by increasing a rotational speed of the pump81(which is a pump for pressure feeding the plating solution Ps in the reservoir tank80toward the plating tank10), a circulating flow rate of the plating solution Ps circulating between the reservoir tank80and the plating tank10can be increased. Accordingly, the flow rate of the plating solution Ps flowing inside the plating tank10can be increased and thus the flow rate of the plating solution Ps flowing from the lower surface side of the ionically resistive element12, passing through the plurality of holes12a, and flowing toward the upper surface side of the ionically resistive element12can be increased.

That is, in this embodiment, the circulating flow rate (L/min) of the plating solution Ps in step S20is preferred to be greater than a circulating flow rate of the plating solution Ps in step S60(referred to as a “reference flow rate (L/min)”). Accordingly, the flow rate of the plating solution Ps flowing from the lower surface side of the ionically resistive element12, passing through the plurality of holes12a, and flowing toward the upper surface side of the ionically resistive element12in step S20becomes greater than the flow rate of the plating solution Ps flowing from the lower surface side of the ionically resistive element12, passing through the plurality of holes12a, and flowing toward the upper surface side of the ionically resistive element12in step S60. As a result, the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be effectively removed.

After step S20, step S30is performed. In step S30, the driving of the paddle70is stopped and the stirring of the plating solution Ps with the paddle70is stopped.

Note that, although a specific example of a time period from when the stirring with the paddle70is started in step S20to when the stirring with the paddle70is stopped in step S30(that is, a stirring time period of the paddle70) is not particularly limited, for example, a predetermined time period selected from two seconds or more to ten seconds or less can be used. Thus, with this embodiment, just by stirring the plating solution Ps with the paddle70for a short period, the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be removed.

After step S30, step S40is performed. In step S40, the substrate Wf is immersed in the plating solution Ps in a state where the stirring of the plating solution Ps with the paddle70is stopped. Specifically, in this embodiment, by the elevating mechanism50moving down the substrate holder30, at least the surface to be plated Wfa of the substrate Wf is immersed in the plating solution Ps.

As in this embodiment, since the substrate Wf is immersed in the plating solution Ps in step S40in a state where the stirring of the plating solution Ps with the paddle70has been stopped in step S30, waves generating on the liquid surface of the plating solution Ps caused by the stirring of the plating solution Ps with the paddle70when the substrate Wf is immersed in the plating solution Ps can be suppressed. Accordingly, a large amount of the gas bubbles Bu getting attached to the surface to be plated Wfa of the substrate Wf when the substrate Wf is immersed in the plating solution Ps can be suppressed.

Note that, in step S40, the surface to be plated Wfa of the substrate Wf may be brought into contact with the plating solution Ps in a state where the substrate holder30is inclined such that the surface to be plated Wfa of the substrate Wf is inclined with respect to the horizontal direction by the inclination mechanism45(that is, such that the surface to be plated Wfa is inclined with respect to the horizontal surface). With this configuration, compared with a case where the surface to be plated Wfa of the substrate Wf is brought into contact with the plating solution Ps in a state where the surface to be plated Wfa is in the horizontal direction, the gas bubbles Bu getting attached to the surface to be plated Wfa can be effectively suppressed.

After step S40, step S50is performed. In step S50, the stirring of the plating solution Ps with the paddle70is resumed in a state where the substrate Wf is immersed in the plating solution Ps. Specifically, in this embodiment, the stirring of the plating solution Ps with the paddle70is resumed by driving the paddle70arranged above the ionically resistive element12and below the substrate Wf alternately in the first direction and the second direction in a state where the substrate Wf is immersed in the plating solution Ps.

Thus, by the stirring of the plating solution Ps with the paddle70being resumed in a state where the plating solution Ps is immersed in the substrate Wf, the plating solution Ps can be effectively supplied onto the surface to be plated Wfa of the substrate Wf. Accordingly, for example, a pre-wet process liquid remaining inside a wiring pattern of the surface to be plated Wfa of the substrate Wf can be effectively replaced with the plating solution Ps.

Furthermore, as described above, in step S40, in a case where the surface to be plated Wfa of the substrate Wf is brought into contact with the plating solution Ps in a state where the surface to be plated Wfa is inclined, the stirring of the plating solution Ps with the paddle70according to step S50is preferred to be resumed after the surface to be plated Wfa of the substrate Wf in a state of being immersed in the plating solution Ps is returned to the horizontal direction. That is, in this case, the surface to be plated Wfa of the substrate Wf is brought into contact with the plating solution Ps in a state where the surface to be plated Wfa is inclined in step S40, then the surface to be plated Wfa of the substrate Wf is returned to the horizontal direction (which is referred to as “step S45”), and then the stirring of the plating solution Ps with the paddle70according to step S50is started.

In a hypothetical case where the stirring of the plating solution Ps with the paddle70is resumed in a state where the surface to be plated Wfa of the substrate Wf is inclined in the horizontal direction, since an upper end of the surface to be plated Wfa (upper end of an outer edge of the surface to be plated Wfa) of the substrate Wf in an inclined state becomes close to the liquid surface of the plating solution Ps, when waves generate on the liquid surface of the plating solution Ps by the stirring of the plating solution Ps with the paddle70being resumed, the gas bubbles Bu may possibly become easier to be drawn to the surface to be plated Wfa of the substrate Wf. In contrast to this, with this configuration, since the stirring of the plating solution Ps with the paddle70is resumed after the surface to be plated Wfa of the substrate Wf in a state of being immersed in the plating solution Ps is returned to the horizontal direction, even in a hypothetical case where waves generate on the liquid surface of the plating solution Ps by the stirring of the plating solution Ps with the paddle70being resumed, the gas bubbles Bu being drawn to the surface to be plated Wfa of the substrate Wf can be effectively suppressed.

After step S50, step S60is performed. In step S60, the plating process is performed on the surface to be plated Wfa of the substrate Wf by flowing electricity between the substrate Wf and the anode11in a state where the stirring of the plating solution Ps with the paddle70is resumed (that is, in a state where the plating solution Ps is being stirred with the paddle70). Accordingly, a plating film made of gold is formed on the surface to be plated Wfa.

As in step S60, by the stirring of the plating solution Ps with the paddle70being performed during the plating process on the substrate Wf, the plating solution Ps can be effectively supplied onto the surface to be plated Wfa of the substrate Wf during the plating process. Accordingly, a plating film can be effectively formed on the substrate Wf.

Note that, the plating process on the substrate Wf according to step S60may be started simultaneously with the resuming of the stirring of the plating solution Ps with the paddle70according to step S50. Alternatively, the plating process on the substrate Wf according to step S60may be started after a predetermined time period passes since the stirring of the plating solution Ps has been resumed according to step S50. Although a specific value of the predetermined time period is not particularly limited, for example, it is preferred that a sufficient time period is spent for allowing the plating solution Ps to reach throughout vias, through-holes, and the like of a wiring pattern formed on the surface to be plated Wfa of the substrate Wf. As an exemplary predetermined time period, for example, a time period selected from 30 seconds or more to 60 seconds or less can be used.

Note that, in step S60, the rotation mechanism40may rotate the substrate holder30. Furthermore, in step S60, the inclination mechanism45may incline the substrate holder30such that the surface to be plated Wfa of the substrate Wf is inclined with respect to the horizontal direction.

Furthermore, a reciprocating movement speed of the paddle70in step S20(first reciprocating movement speed) and a reciprocating movement speed of the paddle70in step S50and step S60(second reciprocating movement speed) may have the same values or different values. In a case where the reciprocating movement speed of the paddle70in step S20and the reciprocating movement speed of the paddle70in step S50and step S60are different, the reciprocating movement speed in step S20may be faster or slower than the reciprocating movement speed in step S50and/or step S60.

However, the faster the reciprocating movement speed of the paddle70is, the higher a removal effect of the gas bubbles Bu tends to become. Furthermore, generally, the amount of gas bubbles Bu attached to the holes12aof the ionically resistive element12is considered to be larger before the start of performing step S20than before the start of performing step S50. Therefore, in terms of effectively removing the gas bubbles Bu attached to the holes12aof the ionically resistive element12, the movement speed of the paddle70in step S20is preferred to be faster than the reciprocating movement speed of the paddle70in step S50and step S60.

Although specific values of the reciprocating movement speed of the paddle70in step S20, step S50, and step S60are not particularly limited, as an example, values selected from a range of 25 (rpm) or more to 400 (rpm) or less can be used, specifically, values selected from a range of 100 (rpm) or more to 300 (rpm) or less can be used, and more specifically, values selected from a range of 150 (rpm) or more to 250 (rpm) or less can be used. Here, “the reciprocating movement speed of the paddle70is N (rpm)” specifically means that the paddle70performs one reciprocation (that is, the paddle70departing from a predetermined position and, for example, moving in the first direction, then the second direction, then moving in the first direction again and returning to the predetermined position) N times per minute.

Note that, the process according toFIG.6may be performed, for example, when supplying a new plating solution Ps (unused plating solution) to the plating tank10during maintenance of the plating apparatus1000. Alternatively, the process according toFIG.6may be performed, for example, when replenishing the plating tank10with the plating solution Ps due to a storage amount of the plating solution Ps in the plating tank10decreasing by some sort of cause and the liquid surface of the plating solution Ps being positioned below the ionically resistive element12during operation of the plating apparatus1000.

With this embodiment as described above, the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be removed. Accordingly, the attached gas bubbles Bu causing the plating quality of the substrate Wf to deteriorate can be suppressed.

FIG.7is an exemplary flowchart for describing a plating method according to Modification 1 of the embodiment. The plating method according to this modification as illustrated inFIG.7is unlike the plating method described inFIG.6in that step S35is further included between step S30and step S40.

In step S35, the plating solution Ps is caused to overflow from the plating tank10in a state where the stirring of the plating solution Ps with the paddle70is stopped.

Specifically, in this modification, the plating solution Ps is caused to overflow from the plating tank10by supplying the plating solution Ps from the supply port13. The plating solution Ps overflowed from the plating tank10flows into the overflow tank20. Note that, it is only necessary for step S35to be performed for a predetermined time period set in advance. Although a specific example of this predetermined time period is not particularly limited, for example, a time period selected from two seconds or more to 120 seconds or less can be used.

According to this modification, since step S35is performed, the gas bubbles Bu floating above the ionically resistive element12can be discharged outside the plating tank10together with the plating solution Ps that overflows from the plating tank10. Accordingly, the gas bubbles Bu getting attached to the substrate Wf when the substrate Wf is immersed in the plating solution Ps in step S40can be effectively suppressed.

Note that, the flow rate of the plating solution Ps supplied to the plating tank10in step S35may be greater than, lower than, or equal to a “reference flow rate (Imin)” that is a flow rate of the plating solution Ps supplied to the plating tank10while performing the plating process according to step S60.

However, a case where the flow rate of the plating solution Ps supplied to the plating tank10in step S35is greater than the reference flow rate is preferred compared with a case where the flow rate of the plating solution Ps supplied to the plating tank10in step S35is not greater than the reference flow rate in that the gas bubbles Bu of the plating solution Ps in the plating tank10can be promptly discharged outside of the plating tank10in step S35.

FIG.8is an exemplary flowchart for describing a plating method according to Modification 2 of the embodiment. The process inFIG.8is performed after performing step S60inFIG.6described above. The plating method according to this modification is unlike the plating method described above inFIG.6in that, after step S60is performed, step S70, step S80, step S90, step S100, step S110and step S120are further performed.

In step S70, after the plating process is performed on the substrate Wf, the substrate Wf is pulled out of the plating solution Ps. Specifically, in this modification, the substrate holder30is moved upward by the elevating mechanism50and the substrate Wf is pulled out of the plating solution Ps.

Next, in step S80, in a state where the substrate Wf is pulled out of the plating solution Ps, the paddle70arranged above the ionically resistive element12is driven to stir the plating solution Ps. Note that, since the driving aspect of the paddle70according to step S80is similar to the driving aspect of the paddle70according to step S20described above, a detailed description of step S80will be omitted.

With this modification, in a state before a second substrate Wf described later is immersed in the plating solution Ps, even in a hypothetical case where the gas bubbles Bu included in the plating solution Ps are attached to the holes12aof the ionically resistive element12, the stirring of the plating solution Ps with the paddle70according to step S80can accelerate the upward movement of the gas bubbles Bu. Accordingly, the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be remove.

Next, instep S90, the stirring of the plating solution Ps with the paddle70is stopped. Next, in step S100, the “second substrate Wf” is immersed in the plating solution Ps in a state where the stirring of the plating solution Ps with the paddle70is stopped. Note that, the second substrate Wf is a substrate on which the plating process is performed after the plating process has been performed on the substrate Wf in step S60. In this modification, a specific configuration of the second substrate Wf is similar to that of the substrate Wf. Furthermore, step S100is similar to step S40described above other than the point of using the second substrate Wf instead of the substrate Wf. Therefore, a detailed description of step S100will be omitted.

According to this modification, since the second substrate Wf is immersed in the plating solution Ps in a state where the stirring of the plating solution Ps with the paddle70is stopped in step S100, waves generating on the liquid surface of the plating solution Ps when the second substrate Wf is immersed in the plating solution Ps can be suppressed. Accordingly, a large amount of the gas bubbles Bu getting attached to a surface to be plated Wfa of the second substrate Wf can be suppressed.

Next, instep S110, the stirring of the plating solution Ps with the paddle70is resumed in a state where the second substrate Wf is immersed in the plating solution Ps. Specifically, the stirring of the plating solution Ps with the paddle70is resumed by driving the paddle70arranged above the ionically resistive element12and below the second substrate Wf alternately in the first direction and the second direction. Note that, the step S110is similar to step S50described above other than the point of using the second substrate Wf instead of the substrate Wf. Therefore, a detailed description of step S110will be omitted.

Next, instep S120, by flowing electricity between the second substrate Wf and the anode11in a state where the stirring of the plating solution Ps with the paddle70has been resumed, the plating process is performed on the surface to be plated Wfa of the second substrate Wf. Accordingly, a plating film made of gold is formed on the surface to be plated Wfa of the second substrate W. Note that, step S120is similar to step S60described above other than the point of using the second substrate Wf instead of the substrate Wf. Therefore, a detailed description of step S120will be omitted. As in step S120, by the stirring of the plating solution Ps with the paddle70being performed during the plating process of the second substrate Wf, the plating solution Ps can be effectively supplied to the surface to be plated Wfa of the second substrate Wf during the plating process. Accordingly, a plating film can be effectively formed on the second substrate Wf.

Note that, in a case where the plating process is performed on a third substrate after the plating process is performed on the second substrate Wf′ it is only necessary to perform a process similar to the process inFIG.8again on the third substrate.

Furthermore, in this modification, step S35inFIG.7described above may be performed between step S90and step S100. In this case, an operational advantage according to Modification 1 described above can be further provided.

FIG.9is a schematic plan view of a paddle70A according to Modification 3 of the embodiment. The paddle70A according to this modification is unlike the paddle70illustrated inFIG.5described above in that, beside the “plurality of stirring members71a(that is, a first stirring member group),” a “plurality of stirring members71b,71c,71d.71e(that is, a second stirring member group)” having shorter lengths in the extending direction compared with the stirring members71aare further included.

Specifically, the paddle70A according to this modification includes the stirring members71b,71c,71d.71eon each the first direction side and the second direction side of the plurality of stirring members71a.

Note that, as illustrated inFIG.9, the more distanced the stirring members71b,71c,71d,71ebecome from the stirring members71a, the shorter the lengths in the extending direction of the stirring members71b,71c,71d,71emay become. Furthermore, one ends of the stirring members71b,71c,71d,71emay be coupled to coupling members72c, and other ends may be coupled to coupling members72d.

According to this modification, since the paddle70A includes the stirring members71b,71c,71d.71e, for example, compared with the paddle70inFIG.5, an area stirrable with the paddle70A when the paddle70A moves a constant distance can be expanded.

Note that, the plating apparatus1000including the paddle70A according to this modification performs the process described inFIG.6described above. In Modification 1 and Modification 2 described above, the paddle70A according to this modification may be used instead of the paddle70.

FIG.10is a schematic plan view of a paddle70B according to Modification 4 of the embodiment. The paddle70B according to this modification is unlike the paddle70illustrated inFIG.5in that a plurality of stirring members71fextending in a predetermined direction and a coupling member72ethat couples both ends of each stirring member71fare included and the coupling member72ehas a ring shape in a plan view.

Furthermore, the paddle70B according to this modification is unlike the paddle70illustrated inFIG.5also in the point of being driven to rotate within a horizontal surface by a driving device77aand a driving device77b. Specifically, the driving device77adrives the coupling member72eof the paddle70B alternately in the Y-direction and the −Y-direction. The driving device77bdrives the coupling member72ealternately in the Y-direction and the −Y-direction. Accordingly, with the center of the ring-shaped coupling member72eas a rotational center, the paddle70B rotates within the horizontal surface alternately in the first rotation direction (such as the clockwise direction in a plan view) and the second rotation direction opposite to the first rotation direction (such as the counterclockwise direction in a plan view).

Even in this modification, since the plating solution Ps can be stirred with the paddle70B, the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be removed.

Note that, the plating apparatus1000including the paddle70B according to this modification performs the process described inFIG.6described above. In Modification 1 and Modification 2 described above, the paddle70B according to this modification may be used instead of the paddle70.

FIG.11is a schematic plan view of a paddle70C according to Modification 5 of the embodiment. The paddle70C according to this modification is unlike the paddle70illustrated inFIG.5in the point of including a plurality of stirring members73constituting a honeycomb structure. Furthermore, as illustrated inFIG.11, the paddle70C according to this modification may further include a covering frame75and outer frames76a,76b.

Each stirring member73constitutes a polygonal through-hole73aextending in an upper/lower direction (vertical direction). A specific shape of the polygon of the through-hole73ais not particularly limited, and various kinds of N polygons (N is a natural number of three or more) such as a triangle, a quadrangle, a pentagon, a hexagon, a heptagon, an octagon, and the like can be used. In this modification, a hexagon is used as an example of the polygon.

The plurality of stirring members73include a polygonal portion74ahaving a quadrangle shape in a plan view. Specifically, the polygonal portion74aaccording to this modification has a rectangular shape extending in the horizontal direction with a perpendicular direction (Y-axis direction) with respect to the first direction and the second direction being the longitudinal direction. However, it is not limited to this configuration, and the polygonal portion74amay have a rectangular shape with the first direction and the second direction being the longitudinal direction, or may have a square shape.

The plurality of stirring members73include a first projecting portion74bprojecting from a side surface on the first direction side of the polygonal portion74atoward the first direction side and a second projecting portion74cprojecting from a side surface on the second direction side of the polygonal portion74atoward the second direction side. That is, an outer edge of the plurality of stirring members73according to this modification has an appearance shape including the polygonal portion74a, the first projecting portion74b, and the second projecting portion74cin a plan view. The first projecting portion74baccording to this modification projects in an arc-like shape (in other words, a bow-like shape) toward the first direction. The second projecting portion74caccording to this modification projects in an arc-like shape (in other words, a bow-like shape) toward the second direction.

The covering frame75is disposed so as to cover the outer edges of the plurality of stirring members73. An outer frame76ais connected to a side surface on one of sides (Y-direction side) of the covering frame75. An outer frame76bis connected to a side surface on another side (−Y-direction side) of the covering frame75. The paddle70C is connected to the driving device77, and is driven alternately in the first direction and the second direction by the driving device77. Specifically, in the paddle70C according to this modification, the outer frame76bof the paddle70C is connected to the driving device77.

Even in this modification, since the plating solution Ps can be stirred with the paddle70C, the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be removed.

Furthermore, according to this modification, since the paddle70C has a honeycomb structure, compared with a case where the paddle70C does not have a honeycomb structure and, for example, is configured of a rod-shaped or a plate-shaped member extending perpendicular to the driving direction of the paddle70C (such as in the case ofFIG.5described above), an arrangement density of the plurality of stirring members73can be increased. Accordingly, the plating solution Ps can be effectively stirred with the paddle70C. As a result, the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be effectively removed.

Furthermore, with this modification, since the plurality of stirring members73of the paddle70C include the polygonal portion74a, the first projecting portion74b, and the second projecting portion74c, for example, compared with a case where the plurality of stirring members73include the polygonal portion74abut does not include the first projecting portion74bor the second projecting portion74c, an area stirrable with the paddle70C when the paddle70C moves a constant distance can be expanded.

Note that, a “paddle width D2” as a maximum value of a distance between the first projecting portion74band the second projecting portion74cmay be larger or smaller than a “substrate width D1(whose reference numeral is denoted inFIG.3)” as a maximum value of a distance between an outer edge in the first direction and an outer edge in the second direction of the surface to be plated Wfa of the substrate Wf. Alternatively, the paddle width D2may have the same value as the substrate width D1.

However, in a case where the paddle width D2is smaller than the substrate width D1, compared with a case where the paddle width D2is the same as the substrate width D1or greater than the substrate width D1, a larger clearance between the paddle70C and the outer peripheral wall10bof the plating tank10can be ensured. As a result, a moving distance in the first direction and the second direction of the paddle70C inside the plating tank10(that is, a stroke of the reciprocation movement of the paddle70C) can be increased. Accordingly, since the plating solution Ps can be effectively stirred with the paddle70C, the gas bubbles Bu attached to the holes12aof the ionically resistive element12can be effectively removed. In these terms, the paddle width D2is preferred to be smaller than the substrate width D1.

Note that, in a case where the surface to be plated Wfa of the substrate Wf has a circular shape, the substrate width D1corresponds to a diameter of the surface to be plated Wfa. In a case where the surface to be plated Wfa of the substrate Wf has a quadrangle shape, the substrate width D1corresponds to a maximum value of a clearance between a side in the first direction of the surface to be plated Wfa and an opposing side (side in the second direction).

The plating apparatus1000including the paddle70C according to this modification performs the process described inFIG.6described above. However, the configuration is not limited to this. As another example, the plating apparatus1000according to this modification may perform the stirring of the plating solution Ps with the paddle70C only either when supplying the plating solution Ps to the plating tank10(step S10, step S20), or when performing the plating process on the substrate Wf (step S50, step S60). Furthermore, in modification 1 (FIG.7) and modification 2 (FIG.8) described above, the paddle70C according to this modification may be used instead of the paddle70.

Although the embodiments and modifications of the present invention have been described in detail above, the present invention is not limited to such specific embodiments or modifications, and further various kinds of variants and modifications are possible within the scope of the present invention described in the claims.

REFERENCE SIGNS LIST