Plating apparatus

Abstract

Provided is a feature with which it is possible to inhibit scattering of a plating solution to the outside of a plating tank when the plating solution is stirred.　A scattering suppression member of a plating apparatus has a first member 61 and a second member 62. The first member is disposed in a region that is above a paddle and that is below the upper end of the outer peripheral wall of a plating tank, is disposed in a region between the outer peripheral wall of the plating tank and a substrate holder, extends in the vertical direction, and extends in a curved surface shape in the circumferential direction of the outer peripheral wall of the plating tank. The second member extends in the horizontal direction, is disposed above the upper end of the outer peripheral wall of the plating tank, is disposed above the first member with a first space present between the second member and the first member, and is disposed outside the substrate holder with a second space present between the second member and the substrate holder. At least a portion of the inner peripheral surface of the first member below the upper end of the first member by a prescribed distance is an inclined surface inclined such that the distance from the center of the plating tank increases toward the upper side.

Description

Plating Apparatus

[0001] The present invention relates to a plating apparatus.

[0002] Conventionally, plating apparatuses capable of performing a plating process on a substrate are known (see, for example, Patent Document 1). Such a plating apparatus generally includes: a plating tank that stores a plating solution and has an anode disposed therein; a substrate holder that holds a substrate serving as a cathode so as to face the anode; and a paddle that is disposed in a region inside the plating tank above the anode and below the substrate holder and configured to agitate the plating solution.

[0003] Japanese Patent No. 7079388

[0004] In the conventional plating apparatus as described above, when the plating solution is agitated, there is a risk that the plating solution splashes up and scatters to the outside of the plating tank. In this respect, conventional plating apparatuses leave room for improvement.

[0005] The present invention has been made in view of the foregoing, and one object of the present invention is to provide a technique capable of suppressing scattering of the plating solution to the outside of the plating tank when the plating solution is agitated.

[0006] (Aspect 1) To achieve the above objective, a plating apparatus according to one aspect of the present invention comprises: a plating tank configured to store a plating solution and having an anode arranged therein; a substrate holder for holding a substrate as a cathode so as to face the anode; a paddle positioned in the interior of the plating tank above the anode and below the substrate holder, configured to agitate the plating solution; and a splash suppression member configured to prevent the plating solution from splashing up and scattering outside the plating tank when the plating solution is agitated by the paddle, wherein the splash suppression member comprises a first member and a second member, the first member being positioned above the paddle and below The second member is positioned in a region below the upper end of the outer peripheral wall of the plating tank and in the region between the outer peripheral wall of the plating tank and the substrate holder, and extends vertically and curved in the circumferential direction of the outer peripheral wall. The second member extends horizontally and is positioned above the upper end of the outer peripheral wall of the plating tank, and is positioned above the first member with a first space between it and the first member, and is positioned outside the substrate holder with a second space between it and the substrate holder. At least a portion of the inner circumferential surface of the first member that is a predetermined distance below the upper end of the first member is an inclined surface that is sloped such that the distance from the center of the plating tank increases as it goes upward.

[0007] According to this embodiment, when the plating solution is stirred by the paddle, it is possible to suppress the scattering of the plating solution outside the plating tank. In particular, according to this embodiment, since the inclined surface is provided on the inner circumferential surface of the first member, the plating solution that flows upward along the inner circumferential surface of the first member can be scattered outward along the inclined surface (away from the center of the plating tank). This effectively suppresses the scattering of the plating solution that flows upward along the inner circumferential surface of the first member from the second space between the second member and the substrate holder to the outside.

[0008] (Aspect 2) In the above-described aspect 1, the predetermined distance may be 20% or more of the total height, which is the distance from the upper end to the lower end of the first member.

[0009] (Aspect 3) In aspect 1 or 2 described above, the inclined surface has an inclination angle with respect to the horizontal plane that is greater than 90°, and the inclined surface has a lower inclined surface and an upper inclined surface located above the lower inclined surface, and the inclination angle of the upper inclined surface may be greater than the inclination angle of the lower inclined surface.

[0010] (Aspect 4) In aspect 3 described above, the inclined surface further has a middle inclined surface located between the lower inclined surface and the upper inclined surface, and the inclination angle of the middle inclined surface may be greater than the inclination angle of the lower inclined surface and less than the inclination angle of the upper inclined surface.

[0011] (Aspect 5) In any one of the above aspects 1 to 4, the inclined surface has an inclination angle with respect to the horizontal plane that is greater than 90°, and the inclination angle of the inclined surface of the first member may have different values ​​depending on the position of the first member in the circumferential direction.

[0012] (Aspect 6) In any one of the above aspects 1 to 5, the inclined surface of the first member may be configured such that a virtual surface obtained by extending the inclined surface of the first member upward abuts against the lower surface of the second member.

[0013] (Aspect 7) Any one of the above aspects 1 to 6 includes an overflow tank located outside the outer peripheral wall of the plating tank, and the second member may be connected to the upper end of the outer peripheral wall of the overflow tank.

[0014] (Aspect 8) Any one of the above aspects 1 to 6 includes an overflow tank located outside the outer peripheral wall of the plating tank, and a support plate is provided on the inner peripheral wall surface of the outer peripheral wall of the overflow tank, extending horizontally in a direction toward the substrate holder from the inner peripheral wall surface, and the second member may be connected to the upper surface of the support plate.

[0015] Figure 7A and Figure 7B are schematic perspective views showing the overall configuration of the plating apparatus according to the embodiment. Figure 7B is a schematic diagram showing the overall configuration of the plating apparatus according to the embodiment. Figure 7B is a schematic diagram showing the state in which the substrate according to the embodiment is immersed in the plating solution. Figure 7B is a schematic diagram for explaining the paddle according to the embodiment. Figure 7B is a schematic diagram for explaining a series of operations from the supply of the plating solution to the start of the plating process according to the embodiment. Figures 7A and 7B are schematic perspective views of the splash suppression member according to the embodiment. Figure 7B is a schematic enlarged cross-sectional view showing how the splash suppression member according to the embodiment is arranged in the plating tank. Figure 7B is a schematic enlarged cross-sectional view showing the flow of the plating solution around the splash suppression member according to the embodiment. Figure 7B is a schematic perspective view of the overflow tank according to the embodiment. Figure 7B is a schematic diagram for explaining in detail the configuration of the first member according to the embodiment. Figure 7B is a schematic diagram for explaining an example in which the inclination angle of the inclined surface of the first member according to the embodiment differs depending on the circumferential position of the first member. Figure 7B is a schematic plan view showing another example of how the first member according to the embodiment is connected to the plating tank. Figure 7B is a schematic diagram for explaining the case in which the first member according to the embodiment has only an upper inclined surface as an inclined surface. This is a schematic diagram illustrating the case in which the first member according to the embodiment has only an upper inclined surface and a lower inclined surface as inclined surfaces. This is a schematic enlarged cross-sectional view illustrating another example of the connection configuration of the scattering suppression member according to the embodiment.

[0016] Embodiments of the present invention will be described below with reference to the drawings. Note that the drawings are schematic in order to facilitate understanding of the characteristics of the components, and the dimensional ratios of each component may not be the same as those of the actual components. Also, some drawings show the X-Y-Z Cartesian coordinate system for reference. In this Cartesian coordinate system, the Z direction corresponds to upward, and the -Z direction corresponds to downward (the direction in which gravity acts).

[0017] Figure 1 is a perspective view showing the overall configuration of the plating apparatus 1000 of this embodiment. Figure 2 is a plan view (top view) showing the overall configuration of the plating apparatus 1000 of this embodiment. As shown in Figures 1 and 2, the plating apparatus 1000 includes a load port 100, a transport robot 110, an aligner 120, a pre-wet module 200, a pre-soak module 300, a plating module 400, a cleaning module 500, a spin rinse dryer 600, a transport device 700, and a control module 800.

[0018] The load port 100 is a module for loading substrates contained in cassettes such as FOUPs (not shown) into the plating apparatus 1000, and for unloading substrates from the plating apparatus 1000 into cassettes. In this embodiment, four load ports 100 are arranged horizontally, but the number and arrangement of load ports 100 are arbitrary. The transport robot 110 is a robot for transporting substrates and is configured to transfer substrates between the load port 100, the aligner 120, the pre-wet module 200, and the spin rinse dryer 600. When transferring substrates between the transport robot 110 and the transport device 700, the substrates can be transferred via a temporary stand (not shown).

[0019] The aligner 120 is a module for aligning the positions of orientation flats, notches, etc., on the substrate in a predetermined direction. In this embodiment, two aligners 120 are arranged side by side horizontally, but the number and arrangement of the aligners 120 are arbitrary. The pre-wet module 200 replaces the air inside the patterns formed on the substrate surface with a treatment solution by wetting the surface of the substrate to be plated with a treatment solution such as pure water or degassed water before the plating process. The pre-wet module 200 is configured to perform a pre-wetting process that makes it easier to supply the plating solution inside the patterns by replacing the treatment solution inside the patterns with the plating solution during plating. In this embodiment, two pre-wet modules 200 are arranged side by side vertically, but the number and arrangement of the pre-wet modules 200 are arbitrary.

[0020] The pre-soak module 300 is configured to perform a pre-soak treatment, which involves etching away an oxide film with high electrical resistance present on the surface of a seed layer formed on the surface of a substrate to be plated before plating, using a treatment solution such as sulfuric acid or hydrochloric acid, thereby cleaning or activating the surface of the substrate. In this embodiment, two pre-soak modules 300 are arranged side by side in the vertical direction, but the number and arrangement of the pre-soak modules 300 are arbitrary. The plating module 400 performs the plating treatment on the substrate. In this embodiment, there are two sets of 12 plating modules 400, arranged in a vertical direction of three modules and horizontal direction of four modules, for a total of 24 plating modules 400, but the number and arrangement of the plating modules 400 are arbitrary.

[0021] The cleaning module 500 is configured to clean the substrate to remove any remaining plating solution after the plating process. In this embodiment, two cleaning modules 500 are arranged side by side in the vertical direction, but the number and arrangement of the cleaning modules 500 are arbitrary. The spin rinse dryer 600 is a module for drying the substrate after the cleaning process by rotating it at high speed. In this embodiment, two spin rinse dryers 600 are arranged side by side in the vertical direction, but the number and arrangement of the spin rinse dryers 600 are arbitrary. The transport device 700 is a device for transporting substrates between multiple modules in the plating apparatus 1000. The control module 800 is configured to control multiple modules of the plating apparatus 1000 and can consist of, for example, a general-purpose computer or a dedicated computer with an input / output interface with an operator.

[0022] An example of a series of plating processes performed by the plating apparatus 1000 will be described. First, substrates contained in cassettes are loaded into the load port 100. Next, the transport robot 110 removes the substrates from the cassettes in the load port 100 and transports them to the aligner 120. The aligner 120 aligns the orientation flats, notches, and other positions of the substrates to a predetermined direction. The transport robot 110 then transfers the substrates, whose orientation has been aligned by the aligner 120, to the pre-wet module 200.

[0023] The pre-wetting module 200 performs a pre-wetting treatment on the substrate. The transport device 700 transports the pre-wetting substrate to the pre-soak module 300. The pre-soak module 300 performs a pre-soak treatment on the substrate. The transport device 700 transports the pre-soaked substrate to the plating module 400. The plating module 400 performs a plating treatment on the substrate.

[0024] The transport device 700 transports the plated substrate to the cleaning module 500. The cleaning module 500 cleans the substrate. The transport device 700 then transports the cleaned substrate to the spin rinse dryer 600. The spin rinse dryer 600 dries the substrate. The transport robot 110 receives the substrate from the spin rinse dryer 600 and transports the dried substrate to the cassette in the load port 100. Finally, the cassette containing the substrate is discharged from the load port 100.

[0025] The configuration of the plating apparatus 1000 described in Figures 1 and 2 is merely an example, and the configuration of the plating apparatus 1000 is not limited to the configurations shown in Figures 1 and 2.

[0026] Next, the plating module 400 will be described. Since the multiple plating modules 400 in the plating apparatus 1000 according to this embodiment have similar configurations, only one plating module 400 will be described.

[0027] Figure 3 is a schematic diagram showing the configuration of the plating module 400 in the plating apparatus 1000 according to this embodiment. Specifically, Figure 3 schematically illustrates the plating module 400 before the substrate Wf is immersed in the plating solution Ps. Figure 4 is a schematic diagram showing the state after the substrate Wf has been immersed in the plating solution Ps. Note that in Figures 3 and 4, only some of the scattering suppression members 60a and 60b, which will be described later, are shown as examples.

[0028] The plating apparatus 1000 illustrated in Figures 3 and 4 is, as an example, a type of plating apparatus (a so-called cup-type plating apparatus) in which the substrate Wf is immersed in the plating solution Ps with its surface direction oriented horizontally.

[0029] The plating module 400 of the plating apparatus 1000 illustrated in Figures 3 and 4 comprises a plating tank 10, an overflow tank 20, a substrate holder 30, and a paddle 70. The plating module 400 may also include a rotating mechanism 40, a tilting mechanism 45, and a lifting mechanism 50, as illustrated in Figure 3.

[0030] The plating tank 10 according to this embodiment is composed of a bottomed container with an opening at the top. Specifically, the plating tank 10 has a bottom wall 10a and an outer peripheral wall 10b that extends upward from the outer peripheral edge of the bottom wall 10a, with the upper part of the outer peripheral wall 10b being open. The shape of the outer peripheral wall 10b of the plating tank 10 is not particularly limited, but the outer peripheral wall 10b according to this embodiment has a cylindrical shape as an example. A plating solution Ps is stored inside the plating tank 10.

[0031] The plating solution Ps can be any solution containing ions of the metal elements that constitute the plating film, and its specific examples are not particularly limited. In this embodiment, copper plating is used as an example of a plating process, and copper sulfate solution is used as an example of the plating solution Ps. The plating solution Ps may also contain predetermined additives.

[0032] An anode 11 is placed inside the plating tank 10. The specific type of anode 11 is not particularly limited and may be an insoluble anode or a soluble anode. In this embodiment, an insoluble anode is used as an example of anode 11. The specific type of this insoluble anode is not particularly limited and can be platinum, iridium oxide, or the like.

[0033] As illustrated in Figures 3 and 4, an ion resistor 12 may be positioned above the anode 11 inside the plating tank 10. Specifically, as illustrated in the partially enlarged view of Figure 4, the ion resistor 12 is made up of a porous plate member having a plurality of holes 12a (pores). The holes 12a are provided so as to connect the lower surface and the upper surface of the ion resistor 12.

[0034] This ion resistor 12 is provided to homogenize the electric field formed between the anode 11 and the substrate Wf, which acts as the cathode. As in this embodiment, by arranging the ion resistor 12 in the plating tank 10, it is possible to easily homogenize the thickness of the plating film (plating layer) formed on the substrate Wf.

[0035] As illustrated in Figures 3 and 4, a film 16 may be placed inside the plating tank 10 above the anode 11 and below the ion resistor 12. In this case, the inside of the plating tank 10 is divided by the film 16 into an anode chamber 17a below the film 16 and a cathode chamber 17b above the film 16. The anode 11 is placed in the anode chamber 17a, and the ion resistor 12 and substrate Wf are placed in the cathode chamber 17b. The film 16 is configured to allow ionic species containing metal ions contained in the plating solution Ps to pass through the film 16, while suppressing the passage of nonionic plating additives contained in the plating solution Ps. For example, an ion exchange film can be used as such a film 16.

[0036] The plating tank 10 is provided with a supply port for supplying the plating solution Ps to the plating tank 10. Specifically, the outer peripheral wall 10b of the plating tank 10 according to this embodiment is provided with a first supply port 13a for supplying the plating solution Ps to the anode chamber 17a and a second supply port 13b for supplying the plating solution Ps to the cathode chamber 17b.

[0037] Furthermore, the plating tank 10 is provided with a first outlet 14a for discharging the plating solution Ps from the anode chamber 17a to the outside of the plating tank 10. The plating solution Ps discharged from the first outlet 14a is pumped (not shown) and supplied again to the anode chamber 17a from the first supply port 13a.

[0038] The overflow tank 20 is a bottomed container located outside the plating tank 10. The overflow tank 20 is provided to temporarily store the plating solution Ps that exceeds the upper end of the outer peripheral wall 10b of the plating tank 10 (i.e., the plating solution Ps that overflows from the plating tank 10). The plating solution Ps stored in the overflow tank 20 is discharged from the second outlet 14b, then pumped (not shown) under pressure and supplied again to the cathode chamber 17b from the second supply port 13b.

[0039] The substrate holder 30 holds the substrate Wf, which serves as the cathode, such that the plated surface Wfa of the substrate Wf faces the anode 11. In this embodiment, the plated surface Wfa of the substrate Wf is specifically located on the surface (bottom surface) facing downwards.

[0040] The substrate holder 30 is connected to the rotating mechanism 40. The rotating mechanism 40 is a mechanism for rotating the substrate holder 30. "R1" shown in Figure 3 is an example of the rotation direction of the substrate holder 30. A known rotary motor or the like can be used as the rotating mechanism 40. The tilting mechanism 45 is a mechanism for tilting the rotating mechanism 40 and the substrate holder 30. The lifting mechanism 50 is supported by a support shaft 51 that extends in the vertical direction. The lifting mechanism 50 is a mechanism for raising and lowering the substrate holder 30, the rotating mechanism 40 and the tilting mechanism 45 in the vertical direction. A known lifting mechanism such as a linear actuator can be used as the lifting mechanism 50.

[0041] The control module 800 is equipped with a microcomputer, which includes a processor 801 and a storage device 802 as a non-temporary storage medium. The control module 800 controls the operation of the plating module 400 by having the processor 801 operate based on program instructions stored in the storage device 802.

[0042] Fig. 5 is a schematic diagram for explaining the paddle 70. Referring to Figs. 4 and 5, the paddle 70 is arranged in a region inside the plating tank 10 above the anode 11 and below the substrate holder 30. Specifically, the paddle 70 according to the present embodiment is arranged between the ion resistor 12 arranged above the anode 11 and the substrate holder 30.

[0043] Referring to Fig. 5, the paddle 70 is a "stirring member" configured to be driven by a driving device 90 to stir the plating solution Ps. As an example, the driving device 90 according to the present embodiment receives instructions from a control module 800, and drives the paddle 70 alternately in a "first direction (1st)" parallel to the anode 11 (or the substrate Wf) and in a "second direction (2nd)" opposite to the first direction. That is, the paddle 70 according to the present embodiment reciprocates in the first direction and the second direction.

[0044] It should be noted that known techniques can be applied to the mechanical mechanism itself of such a driving device 90. Specifically, the driving device 90 according to the present embodiment includes an electric motor 91, and a power conversion mechanism 92 that is connected to the paddle 70 and configured to convert the rotational motion of the electric motor 91 into linear reciprocating motion and transmit the motion to the paddle 70.

[0045] It should be noted that the first direction and the second direction are not limited to the above-described directions. In addition, a direction perpendicular to the reciprocating movement direction of the paddle 70 is referred to as a "third direction (3rd)". Fig. 5 also illustrates, as central axes of the paddle 70, a first central axis line XL1 extending in the third direction and a second central axis line XL2 extending in the reciprocating movement direction of the paddle 70.

[0046] It should be noted that the paddle 70 only needs to be arranged inside the plating tank 10 when stirring at least the plating solution Ps, and does not need to be always arranged inside the plating tank 10. For example, when the driving of the paddle 70 is stopped and the stirring of the plating solution Ps by the paddle 70 is not performed, the paddle 70 may be configured to be arranged outside the plating tank 10.

[0047] There is no particular limitation on the specific configuration of the paddle 70, as long as it can agitate the plating solution Ps. As an example, the paddle 70 illustrated in FIG. 5 includes a honeycomb structure portion 71 having a honeycomb structure, and a pair of outer frames (a first outer frame 72a and a second outer frame 72b) connected to ends of the honeycomb structure portion 71 in the third direction. The specific structures of the first outer frame 72a and the second outer frame 72b are not particularly limited, and in the present embodiment, the first outer frame 72a and the second outer frame 72b are configured by flat plate-shaped members as an example. At least one of the first outer frame 72a and the second outer frame 72b is connected to a drive device 90.

[0048] The honeycomb structure portion 71 has a plurality of polygonal holes 74 defined by beam members 73. The holes 74 according to the present embodiment penetrate vertically to allow communication between the upper surface and the lower surface of the honeycomb structure portion 71. The honeycomb structure portion 71 further includes a first outer peripheral wall 75 facing the first direction and a second outer peripheral wall 76 facing the second direction. The first outer peripheral wall 75 and the second outer peripheral wall 76 are formed by the beam members 73.

[0049] Furthermore, the paddle 70 illustrated in FIG. 5 has a configuration in which "paddle width D1 (length of the paddle 70 in the reciprocating direction)" of the honeycomb structure portion 71 changes along the third direction in plan view. Specifically, the paddle 70 has a shape where the paddle width D1 at the central portion in the third direction is wider than the paddle width D1 at the end portions in the third direction. In other words, the paddle 70 has a shape in which a portion closer to the center than the end portions in the third direction protrudes further in the first direction and the second direction than the end portions. In addition, as an example, the paddle 70 according to the present embodiment has a line-symmetrical (bilaterally symmetrical) shape across the second central axis XL2.

[0050] It should be noted that the configuration of the paddle 70 is not limited to the above-described configuration as long as it can agitate the plating solution Ps, and may be any other known configuration. As another example, instead of the honeycomb structure portion 71, the paddle 70 may include a plurality of beam members extending linearly in the third direction.

[0051] Figure 6 is a flowchart illustrating a series of operations from the supply of the plating solution to the start of the plating process according to this embodiment. First, the plating solution Ps is supplied to the plating tank 10 (step S10). Specifically, the plating solution Ps is supplied to the plating tank 10 so that the anode 11 and the ion resistor 12 are immersed in the plating solution Ps. More specifically, in this embodiment, the plating solution Ps is supplied to the plating tank 10 from the first supply port 13a and the second supply port 13b.

[0052] Next, the substrate Wf is immersed in the plating solution Ps (step S20). Specifically, in this embodiment, the lifting mechanism 50 lowers the substrate holder 30, thereby immersing at least the surface Wfa of the substrate Wf to be plated in the plating solution Ps.

[0053] Next, the drive unit 90 starts driving the paddle 70, thereby starting the stirring of the plating solution Ps by the paddle 70 (step S30).

[0054] Next, an electric current is passed between the anode 11 and the substrate Wf by an energizing device (not shown) to start the plating process on the substrate Wf (step S40). This starts the formation of a plating film on the plated surface Wfa of the substrate Wf. Specifically, in this embodiment, even while the plating process on the substrate Wf in step S40 is being performed, the plating solution Ps is stirred by the paddle 70 in step S30 (that is, the plating solution Ps is stirred while a plating film is formed on the plated surface Wfa). It is preferable that the control module 800 rotates the substrate holder 30 at least during the plating process in step S40.

[0055] Referring to Figures 3 and 4, the plating module 400 of the plating apparatus 1000 according to this embodiment further comprises a scattering suppression member 60a (i.e., a first scattering suppression member) and a scattering suppression member 60b (i.e., a second scattering suppression member).

[0056] Figure 7A is a schematic perspective view of the splash suppression member 60a. Figure 7B is a schematic perspective view of the splash suppression member 60b. Figure 8 is a schematic enlarged cross-sectional view showing the splash suppression member 60a positioned in the plating tank 10 (this Figure 8 corresponds to an enlarged cross-sectional view of portion A1 in Figure 4). Figure 9 is a schematic enlarged cross-sectional view showing the flow of the plating solution Ps around the splash suppression member 60a.

[0057] Referring to Figures 7 to 9, the splash suppression members 60a and 60b are configured to suppress the splashing of the plating solution Ps outside the plating tank 10 when the plating solution Ps is stirred by the paddle 70. Specifically, the splash suppression members 60a and 60b are placed in the plating tank 10 and used at least when the plating solution Ps is stirred by the paddle 70 (i.e., at least when the paddle 70 is driven). The splash suppression members 60a and 60b can be referred to as "splash suppression cover members".

[0058] The specific way in which the scattering suppression members 60a and 60b are connected to the plating apparatus 1000 is not particularly limited, but in this embodiment, as an example, the scattering suppression members 60a and 60b are connected to the outer peripheral wall 21 of the overflow tank 20 (i.e., the outer tank). Specifically, the scattering suppression members 60a and 60b may have a second member 62, which will be described later, connected to the upper end 21a of the outer peripheral wall 21 of the overflow tank 20 (see Figures 8 and 9).

[0059] Specifically, as illustrated in Figure 10, the outer peripheral wall 21 of the overflow tank 20 according to this embodiment has a rectangular shape in plan view, for example. The upper end 21a of the outer peripheral wall 21 of the overflow tank 20 is located above the upper end of the outer peripheral wall 10b of the plating tank 10. Referring to Figures 7A, 7B, and 10, the scattering suppression member 60a is placed on the upper end 21a of the outer peripheral wall 21 of the overflow tank 20 such that a predetermined location C1a of the scattering suppression member 60a corresponds to a predetermined location C1b of the outer peripheral wall 21 of the overflow tank 20, and a predetermined location C2a of the scattering suppression member 60a corresponds to a predetermined location C2b of the outer peripheral wall 21. Similarly, the scattering suppression member 60b is placed on the upper end 21a of the outer wall 21 of the overflow tank 20 such that a predetermined location C3a of the scattering suppression member 60b corresponds to a predetermined location C3b of the outer wall 21 of the overflow tank 20, and a predetermined location C4a of the scattering suppression member 60b corresponds to a predetermined location C4b of the outer wall 21.

[0060] The splash suppression members 60a and 60b connected to the outer peripheral wall 21 of the overflow tank 20 may be fixed to the outer peripheral wall 21 by, for example, detachable fastening members such as bolts or pins.

[0061] However, the above example is merely one example of how the scattering suppression members 60a and 60b can be connected to the overflow tank 20. For example, the scattering suppression members 60a and 60b may be connected as follows. Figure 17 is a schematic enlarged cross-sectional view illustrating another example of how the scattering suppression members 60a and 60b can be connected. As illustrated in Figure 17, a support plate 22 may be provided on the inner circumferential wall surface 21b of the outer circumferential wall 21 of the overflow tank 20, extending horizontally from this inner circumferential wall surface 21b toward the substrate holder 30. Specifically, the support plate 22 illustrated in Figure 17 is located above the upper end 10ba of the outer circumferential wall 10b of the plating tank 10. In this case, the scattering suppression members 60a and 60b may have a second member 62, described later, connected to the upper surface 22a of the support plate 22.

[0062] Referring to Figures 7 to 9, the scattering suppression members 60a and 60b each comprise a first member 61 and a second member 62, respectively. Since the configuration of the scattering suppression member 60b is the same as that of the scattering suppression member 60a, the scattering suppression member 60a will be described in detail from this point forward.

[0063] Referring to Figures 8 and 9, the first member 61 is positioned above the paddle 70 and below the upper end 10ba of the outer peripheral wall 10b of the plating tank 10. Specifically, the first member 61 illustrated in Figures 8 and 9 is positioned, as an example, above the paddle 70 and below the liquid level Ls of the plating solution Ps. As illustrated in Figures 8 and 9, the entire first member 61 may be positioned inside the plating solution Ps, but the configuration is not limited to this. For example, it is sufficient if at least a part of the first member 61 is positioned inside the plating solution Ps.

[0064] Furthermore, the first member 61 is positioned in the region between the outer peripheral wall 10b of the plating tank 10 and the substrate holder 30. In this embodiment, the first member 61 is, for example, made of a plate member (a plate-shaped member). The first member 61 has an inner peripheral surface 61a on the side facing the substrate holder 30 and an outer peripheral surface 61b on the side facing the outer peripheral wall 10b. The first member 61 is positioned inside the plating tank 10 such that its inner peripheral surface 61a does not come into contact with the substrate holder 30 and its outer peripheral surface 61b does not come into contact with the outer peripheral wall 10b of the plating tank 10.

[0065] Furthermore, the first member 61 extends in the vertical direction and also extends in a curved shape in the circumferential direction of the outer peripheral wall 10b of the plating tank 10 (or the circumferential direction of the substrate holder 30). Specifically, in this embodiment, the first member 61 extends in a curved shape in the circumferential direction of the outer peripheral wall 10b so as to conform to the shape of the inner circumferential surface of the outer peripheral wall 10b of the plating tank 10 (in this embodiment, a shape that extends in a curved shape in the circumferential direction of the outer peripheral wall 10b).

[0066] As illustrated in Figure 7A, in this embodiment, both circumferential ends of the first member 61 are connected to the second member 62 via connecting members 65.

[0067] However, the configuration is not limited to this. Figures 13 and 14 are schematic diagrams showing another example of how the first member 61 is connected to the plating tank 10. For example, the first member 61 is not connected to the second member 62, but instead may be directly connected to the plating tank 10 via at least one connecting member 68, as illustrated in Figures 13 and 14.

[0068] Specifically, in the configuration illustrated in Figures 13 and 14, the first member 61 is connected, for example, to the inner surface of the outer circumferential wall 10b of the plating tank 10 via two connecting members 68. Specifically, in this case, the two connecting members 68 may connect the lower end 61d of the first member 61 to the outer circumferential wall 10b of the plating tank 10. Alternatively, the two connecting members 68 may be positioned at one end and the other end of the first member 61 in the circumferential direction.

[0069] Figure 11 is a schematic diagram illustrating in detail the configuration of the first member 61. Specifically, Figure 11 shows a schematic cross-sectional view of the first member 61 and a part of the second member 62 in an enlarged view. Referring to Figure 11, at least the portion of the inner circumferential surface 61a of the first member 61 located at a predetermined distance (d2) below the upper end 61c of the first member 61 is an inclined surface 67 such that the distance (r1) from the center of the plating tank 10 increases as it goes upwards.

[0070] The specific value of this predetermined distance (d2) is not particularly limited, but for example, a value of 20% or more of the "total height (La)", which is the distance from the upper end 61c to the lower end 61d of the first member 61, can be used, more specifically a value of 40% or more, and even more specifically a value of 50% or more.

[0071] In the embodiment illustrated in Figure 11, the value of 100% of the total height (La) of the first member 61 is used as an example of the predetermined distance (d2). That is, the inclined surface 67 of the first member 61 illustrated in Figure 11 is provided from the upper end 61c to the lower end 61d of the first member 61. In other words, the inner circumferential surface 61a of the first member 61 illustrated in Figure 11 is an inclined surface 67 overall.

[0072] Furthermore, the inclined surface 67 of the first member 61 illustrated in Figure 11 has, in order from the top, an upper inclined surface 67a, a middle inclined surface 67b, and a lower inclined surface 67c.

[0073] Here, the inclined surface 67 according to this embodiment has an "angle of inclination with respect to the horizontal plane hp that is greater than 90°". Specifically, this angle of inclination refers to the angle between the upper surface of a hypothetical horizontal plane hp that intersects the inclined surface 67 and the surface of the inclined surface 67 (which is greater than 90°).

[0074] More specifically, in Figure 11, the upper inclined surface 67a has an inclination angle α1, the middle inclined surface 67b has an inclination angle α2, and the lower inclined surface 67c has an inclination angle α3.

[0075] Furthermore, as illustrated in Figure 11, in this embodiment, the inclination angle α1 of the upper inclined surface 67a is greater than the inclination angle α2 of the middle inclined surface 67b, and the inclination angle α2 of the middle inclined surface 67b is greater than the inclination angle α3 of the lower inclined surface 67c. In other words, the inclination angle α2 of the middle inclined surface 67b is greater than the inclination angle α3 of the lower inclined surface 67c, and smaller than the inclination angle α1 of the upper inclined surface 67a. To put it another way, the distance (r1) from the center of the plating tank 10 decreases in the order of the upper inclined surface 67a, the middle inclined surface 67b, and the lower inclined surface 67c.

[0076] The specific values ​​of the inclination angles α1, α2, and α3 are not particularly limited as long as they are greater than 90°, but for example, values ​​selected from the range of 95° to 130° may be used.

[0077] Furthermore, as illustrated in Figure 11, the inclined surface 67 may be configured such that a virtual surface L1, which is an extension of the inclined surface 67 upward, abuts against the lower surface 62a of the second member 62. Specifically, in Figure 11, as an example, a virtual surface L1, which is an extension of the upper inclined surface 67a upward, abuts against the lower surface 62a of the second member 62. Although not shown in the figure, the virtual surfaces of the middle inclined surface 67b and the lower inclined surface 67c also abut against the lower surface 62a of the second member 62.

[0078] Note that the configuration illustrated in Figure 11 is merely one example of the first member 61, and the configuration of the first member 61 is not limited to this. To give another example, as illustrated in Figure 15, the first member 61 may have only an upper inclined surface 67a as the inclined surface 67. In this case, the portion of the inner circumferential surface 61a of the first member 61 other than the upper inclined surface 67a may be a vertical wall surface.

[0079] Alternatively, as illustrated in Figure 16, the first member 61 may have an upper inclined surface 67a and a lower inclined surface 67c as its inclined surface 67, but may not have a middle inclined surface 67b. In this case, the inclination angle α1 of the upper inclined surface 67a is greater than the inclination angle α3 of the lower inclined surface 67c. Alternatively, the inclined surface 67 of the first member 61 may be composed of inclined surfaces having four or more different inclination angles.

[0080] Furthermore, the inclination angle of the inclined surface 67 of the first member 61 may be the same value over the circumferential direction of the first member 61. In other words, the inclination angle of the inclined surface 67 of the first member 61 may be uniform over the circumferential direction of the first member 61.

[0081] Alternatively, the inclination angle of the inclined surface 67 of the first member 61 may have different values ​​depending on the circumferential position of the first member 61. Figure 12 is a schematic diagram illustrating an example where the inclination angle of the inclined surface 67 of the first member 61 differs depending on the circumferential position of the first member 61. Specifically, the right side of Figure 12 shows a schematic plan view (top view) of the first member 61, and the left side of Figure 12 shows schematic partial cross-sectional views of the first member 61 at different circumferential positions.

[0082] Referring to Figures 12 and 11, a specific example of a case where the inclination angle of the inclined surface 67 differs depending on the circumferential position of the first member 61 is as follows: For example, in the circumferential direction of the first member 61, the central part E1a may have a smaller inclination angle of the inclined surface 67 with respect to the horizontal plane compared to the parts of the first member 61 other than the central part E1a (i.e., the inclination angle of the central part E1a may be the shallowest). In this case, "central part E1a" refers to a predetermined range of region centered on the circumferential center of the first member 61. The specific value of this range of central part E1a is not particularly limited, but for example, a range of 10% to 30% of the circumferential length (Lb) of the first member 61 may be used.

[0083] In this case, the inclination angle of the inclined surface 67 of the first member 61 may be configured such that, as illustrated in Figure 12, the inclination angle of the inclined surface 67 is smallest at the central part E1a and increases as it approaches both ends E1b. That is, in this case, the inclination angle of the central part E1a is smallest, and the inclination angles of both ends E1b are largest.

[0084] In the above case, for example, the inclination angles of all three inclined surfaces 67, the upper inclined surface 67a, the middle inclined surface 67b, and the lower inclined surface 67c, may have different values ​​depending on their circumferential position on the first member 61. Alternatively, only the inclination angle of the upper inclined surface 67a may have different values ​​depending on its circumferential position on the first member 61, while the inclination angles of the middle inclined surface 67b and the lower inclined surface 67c may be the same value across the circumferential direction of the first member 61.

[0085] However, the above example is merely one example of a case where the inclination angle of the inclined surface 67 differs depending on the circumferential position of the first member 61, and the manner in which the inclination angle of the inclined surface 67 changes is not limited to the above example.

[0086] Next, the details of the second member 62 will be described. Referring again to Figure 8, the second member 62 is positioned above the upper end 10ba of the outer peripheral wall 10b of the plating tank 10. The second member 62 is also positioned above the first member 61, with a space SP1 (i.e., the "first space") between it and the first member 61. A space SP3 (i.e., the "third space") may be provided between the second member 62 and the upper end 10ba of the outer peripheral wall 10b. This allows the plating solution Ps that overflows from the outer peripheral wall 10b of the plating tank 10 to pass through this space SP3 and flow into the overflow tank 20. Furthermore, in this embodiment, the second member 62 is positioned above the liquid level Ls of the plating solution Ps.

[0087] Referring to Figure 8, the second member 62 is positioned so as not to come into contact with the substrate holder 30. Specifically, the second member 62 is positioned outside the substrate holder 30, with a space SP2 (i.e., the "second space") between it and the substrate holder 30.

[0088] Furthermore, the second member 62 in this embodiment extends horizontally. Specifically, the second member 62 in this embodiment is composed of a plate member having a horizontally extending lower surface 62a. Referring to Figure 9, the lower surface 62a of this second member 62 is configured to bring the plating solution Ps that splashes upward along the first member 61 into contact with this lower surface 62a. Specifically, the lower surface 62a of the second member in this embodiment is located directly above the first member 61, and extends a predetermined distance towards the center of the plating tank 10, starting from the point directly above the first member 61, and also extends a predetermined distance towards the outer periphery of the plating tank 10.

[0089] The aforementioned space SP1 (the space provided between the first member 61 and the second member 62) is primarily provided to allow the plating solution Ps that comes into contact with the lower surface 62a of the second member 62 to escape horizontally.

[0090] If a space SP1 is not provided between the first member 61 and the second member 62, the flow of the plating solution Ps in the plating tank 10 may concentrate between the substrate holder 30 and the splash suppression member 60a, particularly between the first member 61. In this case, the plating solution Ps in the plating tank 10 may forcefully spray upward from between the substrate holder 30 and the splash suppression member 60a and splash to the outside through space SP2. In contrast, according to this embodiment, a space SP1 is provided between the first member 61 and the second member 62, so such a problem can be effectively suppressed.

[0091] Referring to Figure 11, the specific value of the distance d1 between the first member 61 and the second member 62 is not particularly limited, but for example, a value selected from the range of 1 mm to 7 mm can be used, and more specifically, a value selected from the range of 3 mm to 5 mm can be used.

[0092] As described above, in this embodiment, since the splash suppression members 60a and 60b are equipped with the first member 61, when the plating solution Ps is stirred by the paddle 70 (or when the substrate holder 30 is further rotated), the first member 61 can reduce the momentum of the plating solution Ps flowing from the outer peripheral wall 10b side of the plating tank 10 toward the center side of the plating tank 10, or from the center side of the plating tank 10 toward the outer peripheral wall 10b side. This prevents the plating solution Ps from forcefully impacting the substrate holder 30 or the outer peripheral wall 10b. As a result, it is possible to prevent the plating solution Ps from splashing outside the plating tank 10.

[0093] Furthermore, according to this embodiment, since the splash suppression members 60a and 60b are equipped with a second member 62, when the plating solution Ps that has been stirred and flowed by the paddle 70 splashes upward along the first member 61, the lower surface 62a of the second member 62 can catch this splashed plating solution Ps (see Figure 9). The plating solution Ps caught by this lower surface 62a can then be released horizontally in the space SP1. This effectively prevents the plating solution Ps from splashing outside the plating tank 10.

[0094] Furthermore, according to this embodiment, since the inclined surface 67 described above is provided on the inner circumferential surface 61a of the first member 61, the plating solution Ps that flows upward along the inner circumferential surface 61a of the first member 61 can be scattered outward along the inclined surface 67 (away from the center of the plating tank 10) (see Figure 9). This effectively prevents the plating solution Ps that flows upward along the inner circumferential surface 61a of the first member 61 from scattering to the outside from the space SP2 between the second member 62 and the substrate holder 30.

[0095] Although embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various further modifications and changes are possible within the scope of the gist of the present invention.

[0096] 10 Plating tank 10b Outer wall of the plating tank 10ba Upper end of the outer wall of the plating tank 11 Anode 20 Overflow tank 21 Outer wall of the overflow tank 21a Upper end of the outer wall of the overflow tank 21b Inner wall surface of the outer wall of the overflow tank 22 Support plate 22a Upper surface of the support plate 30 Substrate holder 60a, 60b Splash suppression member 61 First member 61a Inner surface of the first member 61c Upper end of the first member 61d Lower end of the first member 62 Second member 62a Lower surface of the second member 67 Inclined surface 67a Upper inclined surface 67b Middle inclined surface 67c Lower inclined surface 70 Paddle 1000 Plating apparatus L1 Virtual surface Ps Plating solution SP1 Space (first space) SP2 Space (second space) Wf Substrate d2 Predetermined distance α1, α2, α3 Inclination angle

Claims

1. A plating tank configured to store a plating solution and having an anode positioned thereon; a substrate holder for holding a substrate as a cathode so as to face the anode; a paddle positioned in a region above the anode and below the substrate holder inside the plating tank and configured to agitate the plating solution; and a splash suppression member configured to prevent the plating solution from splashing up and scattering outside the plating tank when the plating solution is agitated by the paddle, wherein the splash suppression member comprises a first member and a second member, the first member positioned in a region above the paddle and below the upper end of the outer peripheral wall of the plating tank and in the region between the outer peripheral wall of the plating tank and the substrate holder, and extending in the vertical direction and extending in a curved shape in the circumferential direction of the outer peripheral wall, The plating apparatus wherein the second member extends horizontally and is positioned above the upper end of the outer peripheral wall of the plating tank, is positioned above the first member with a first space between it and the first member, and is positioned outside the substrate holder with a second space between it and the substrate holder, and at least a portion of the inner circumferential surface of the first member that is a predetermined distance below the upper end of the first member is an inclined surface that is inclined such that the distance from the center of the plating tank increases as it goes upward.

2. The plating apparatus according to claim 1, wherein the predetermined distance is 20% or more of the total height, which is the distance from the upper end to the lower end of the first member.

3. The plating apparatus according to claim 1, wherein the inclined surface has an inclination angle greater than 90° with respect to a horizontal plane, the inclined surface comprises a lower inclined surface and an upper inclined surface located above the lower inclined surface, and the inclination angle of the upper inclined surface is greater than the inclination angle of the lower inclined surface.

4. The plating apparatus according to claim 3, wherein the inclined surface further comprises a middle inclined surface located between the lower inclined surface and the upper inclined surface, and the inclination angle of the middle inclined surface is greater than the inclination angle of the lower inclined surface and smaller than the inclination angle of the upper inclined surface.

5. The plating apparatus according to claim 1, wherein the inclined surface has an inclination angle greater than 90° with respect to a horizontal plane, and the inclination angle of the inclined surface of the first member has different values ​​depending on the circumferential position of the first member.

6. The plating apparatus according to claim 1, wherein the inclined surface of the first member is configured such that a virtual surface, which is an upward extension of the inclined surface of the first member, abuts against the lower surface of the second member.

7. The plating apparatus according to claim 1, further comprising an overflow tank located outside the outer peripheral wall of the plating tank, wherein the second member is connected to the upper end of the outer peripheral wall of the overflow tank.

8. The plating apparatus according to claim 1, further comprising an overflow tank located outside the outer peripheral wall of the plating tank, wherein a support plate is provided on the inner peripheral wall surface of the outer peripheral wall of the overflow tank, extending horizontally in a direction toward the substrate holder from the inner peripheral wall surface, and the second member is connected to the upper surface of the support plate.

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