Plating method and plating apparatus

Abstract

A plating method according to an embodiment of the present disclosure comprises: a plating step for supplying a plating solution to a substrate to form a plating film on the surface of the substrate; an oxidation promoting solution supply step for supplying an oxidation promoting solution to the substrate to oxidize metal residue on the surface of the substrate generated by the plating step; an intermediate drying step for drying the substrate after the oxidation promoting solution supply step to promote oxidation of the metal residue; an alkaline chemical solution supply step for supplying an alkaline chemical solution to the substrate after the intermediate drying step to remove the oxidized metal residue; a rinsing step for supplying a rinsing solution to the substrate after the alkaline chemical solution supply step to remove the alkaline chemical solution from the substrate; and a final drying step for drying the substrate after the rinsing step.

Description

Plating method and plating apparatus

[0001] The present disclosure relates to a plating method and a plating apparatus.

[0002] In the manufacturing process of semiconductor devices, wiring materials are embedded in wiring recesses provided on the surface of substrates such as semiconductor wafers by electroless plating. When electroless plating is performed, metal residues inevitably remain. Patent Document 1 describes that, to remove the metal residues, a post-cleaning process is performed after electroless plating, in which a post-cleaning solution is sprayed onto the substrate in the form of a mist, followed by a pure water rinse and a spin-drying process. Examples of post-cleaning solutions that have been used include an alkaline solution containing TMAH with a pH of approximately 7 to 12, an organic acid containing a surfactant with a pH of 2 to 5, and pure water with a pH of 6 to 8.

[0003] Japanese Patent Application Laid-Open No. 2007-250915

[0004] The present disclosure provides a technique for improving particle removal performance after plating processing.

[0005] A plating method according to one embodiment of the present disclosure includes a plating process step of supplying a plating solution to a substrate to form a plating film on a surface of the substrate; an oxidation-promoting liquid supplying process step of supplying an oxidation-promoting liquid to the substrate to oxidize metal residues on the surface of the substrate that have been formed by the plating process; an intermediate drying process step of drying the substrate after the oxidation-promoting liquid supplying process to promote the oxidation of the metal residues; an alkaline-based chemical solution supplying process step of supplying an alkaline-based chemical solution to the substrate after the intermediate drying process to remove the oxidized metal residues; a rinsing process step of supplying a rinsing liquid to the substrate after the alkaline-based chemical solution supplying process to remove the alkaline-based chemical solution from the substrate; and a final drying process of drying the substrate after the rinsing process.

[0006] According to the above-described embodiment of the present disclosure, particle removal performance after plating processing can be improved.

[0007] 1 is a schematic cross-sectional view of a substrate processing system according to an embodiment of the present invention; FIG. 2 is a schematic vertical cross-sectional view of a configuration example of an electroless plating processing unit; and FIG. 3 is a schematic view illustrating a mechanism for removing metal residues.

[0008] Specific embodiments of the present disclosure will be described with reference to the accompanying drawings. The following embodiments are merely examples of substrate liquid processing methods and substrate liquid processing apparatuses that embody the technical concepts of the present disclosure and do not limit the technical concepts of the present disclosure. Elements shown in each drawing are simplified. The dimensions, shapes, and dimensional ratios of elements in each drawing do not necessarily correspond to corresponding elements in an actual device, and do not necessarily correspond between drawings.

[0009] Fig. 1 is a diagram showing a schematic configuration example of a multilayer wiring forming system 1. In Fig. 1, the X-axis, Y-axis, and Z-axis are perpendicular to each other, the X-axis and Y-axis extend horizontally, and the positive direction of the Z-axis is the vertically upward direction.

[0010] The multilayer wiring forming system (substrate liquid processing system) 1 shown in FIG. 1 includes a loading / unloading station 2, a processing station 3, and a control device 4.

[0011] The loading / unloading station 2 includes a carrier mounting section 11 and a first transfer section 12. A plurality of carriers C are mounted on the carrier mounting section 11, and each carrier C horizontally supports one or a plurality of wafers W. The first transfer section 12 is provided adjacent to the carrier mounting section 11, and includes a first substrate transfer device 13 and a delivery section 14.

[0012] The first substrate transfer device 13 transfers wafers W between each carrier C and the transfer unit 14. The first substrate transfer device 13 in this example is capable of holding a wafer W and moving the wafer W in horizontal and vertical directions, and rotating (pivoting) the wafer W about a vertical axis. The transfer unit 14 temporarily supports a wafer W received from the first substrate transfer device 13, and temporarily supports a wafer W to be transferred to the first substrate transfer device 13. The wafer W transferred from the transfer unit 14 to the first substrate transfer device 13 is returned from the first substrate transfer device 13 to the corresponding carrier C.

[0013] The processing station 3 is provided adjacent to the loading / unloading station 2 (particularly the first transport section 12 ) in the X direction, and includes a second transport section 15 and a plurality of processing units 16 .

[0014] The second transfer unit 15 includes a second substrate transfer device 20 that is movable along the transfer path. The second substrate transfer device 20 is capable of moving the wafer W in horizontal and vertical directions and rotating (pivoting) the wafer W about a vertical axis. The second transfer unit 15 transfers the wafer W received from the transfer unit 14 to a desired processing unit 16, transfers the wafer W between processing units 16, and transfers the wafer W from the processing unit 16 to the transfer unit 14.

[0015] The processing units 16 included in the processing station 3 are arranged on both sides of the transport path (the transport path extending in the X direction in the example shown in FIG. 1 ) of the second substrate transport device 20. The arrangement and number of these processing units 16 are not limited to the example shown in FIG. 1 , and any number of processing units 16 can be arranged in any arrangement.

[0016] Although the processing performed in each processing unit 16 is not limited in principle, at least one processing unit 16 is provided as an electroless plating processing unit (substrate liquid processing apparatus) 17. The electroless plating processing unit 17 performs electroless plating processing on a wafer W, as described below. Furthermore, at least one processing unit 16 may be provided as a reverse sputtering unit 18 used in a first modified example (FIGS. 4A to 4E) described below.

[0017] As an example, the processing units 16 included in the processing station 3 may include a plurality of electroless plating processing units 17, a plurality of CMP processing units, a plurality of heat processing units, and a plurality of cleaning processing units. The CMP (Chemical Mechanical Polishing) processing unit performs CMP processing on the wafer W. The heat processing unit performs a predetermined heat processing on the wafer W. The cleaning processing unit performs cleaning processing on the wafer W and includes, for example, a spin cleaning type cleaning device.

[0018] The control device 4 is, for example, a computer, and includes a control unit 21 and a storage unit 22. The control unit 21 includes a microcomputer having a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), input / output ports, etc., and various circuits. The CPU of the microcomputer reads and executes programs stored in the ROM to control the first transport unit 12, the second transport unit 15, and each processing unit 16 (including the electroless plating processing unit 17).

[0019] The program stored in the storage unit 22 of the control device 4 may be one that has been recorded on a computer-readable storage medium and installed from that storage medium into the storage unit 22. Examples of computer-readable storage media include hard disks (HDs), flexible disks (FDs), compact disks (CDs), magnet optical disks (MOs), and memory cards. The storage unit 22 can be realized by, for example, semiconductor memory elements such as RAM and flash memory, or storage devices such as hard disks and optical disks.

[0020] 2 is a diagram showing an example of the configuration of the electroless plating unit (plating apparatus) 17. In FIG. 2, the configuration inside the housing 30 is shown in perspective.

[0021] The electroless plating processing unit 17 shown in Figure 2 is configured as a single-wafer processing unit 16 that processes wafers W one by one, and includes a housing 30, a substrate rotation and holding mechanism 31, at least a portion of which is provided inside the housing 30, a processing liquid supply mechanism 32, and a cup 33.

[0022] The housing 30 has an openable / closable loading / unloading section (not shown). The wafer W transferred by the second substrate transfer device 20 (see FIG. 1) is transferred into the housing 30 through the open loading / unloading section, and is transferred out of the housing 30 through the open loading / unloading section. Meanwhile, while the wafer W is undergoing various processes (including electroless plating) inside the housing 30, or while no process is being performed inside the housing 30, the loading / unloading section is kept in a closed state, thereby restricting the inflow of outside air into the housing 30.

[0023] The substrate rotating and holding mechanism 31 holds the wafer W and is rotatable together with the wafer W. The substrate rotating and holding mechanism 31 has a hollow cylindrical rotating shaft 31a, a turntable 31b, a wafer chuck 31c, and a first rotation drive unit (not shown). The turntable 31b and the wafer chuck 31c constitute a substrate holding unit. The vertical length of the rotating shaft 31a inside the housing 30 is changed by a second lifting mechanism (not shown) driven under the control of the control device 4 (see FIG. 1). The turntable 31b is attached to the upper end of the rotating shaft 31a. The wafer chuck 31c is provided on the outer periphery of the upper surface of the turntable 31b and supports the wafer W. By changing the vertical length of the rotating shaft 31a, the height positions (vertical positions) of the turntable 31b and the wafer chuck 31c change integrally. The first rotation drive unit transmits rotational power from a drive source such as a motor to the rotation shaft 31a, and rotates the rotation shaft 31a, the turntable 31b, and the wafer chuck 31c integrally.

[0024] The substrate rotation holding mechanism 31 is driven under the control of the control device 4 (see Figure 1), and the rotational power transmitted from the first rotation drive unit rotates the rotation shaft 31a, turntable 31b, and wafer chuck 31c, which in turn rotates the wafer W supported by the wafer chuck 31c.

[0025] The processing liquid supply mechanism 32 is driven under the control of the control device 4 (see FIG. 1 ) and supplies a processing liquid (e.g., an electroless plating solution) to the surface of the wafer W held by the substrate rotating and holding mechanism 31. The processing liquid supply mechanism 32 in this example includes a processing liquid supply unit 32 a, a discharge head 32 b, a discharge nozzle 32 c, an arm 32 d, a support shaft 32 e, and a processing liquid supply path 32 f.

[0026] The processing liquid supply unit 32a supplies the processing liquid to the discharge head 32b via the processing liquid supply path 32f. The processing liquid supplied to the discharge head 32b is discharged from a discharge nozzle 32c attached to the discharge head 32b and applied to, for example, the processing surface (upper surface) of the wafer W. The discharge head 32b and the discharge nozzle 32c are attached to the tip of an arm 32d and move integrally with the arm 32d. The arm 32d is supported by a support shaft 32e so as to be vertically movable, and is provided inside the housing 30 so as to be vertically movable. The arm 32d also rotates (pivots) integrally with the support shaft 32e so as to be horizontally movable. The support shaft 32e is rotated about a central axis extending vertically by a second rotation drive unit (not shown).

[0027] The processing liquid supply mechanism 32 having the above-described configuration can discharge the processing liquid from the discharge nozzle 32c positioned at a desired height toward any desired location on the processing surface (upper surface) of the wafer W.

[0028] Cup 33 has two discharge ports 33a, 33b disposed at different positions in the vertical direction, and receives the processing liquid scattered from wafer W. Cup 33 is provided so as to be movable in the vertical direction by a second lifting mechanism (not shown) driven under the control of control device 4 (see FIG. 1 ), and the height positions of two discharge ports 33a, 33b are variable. Two discharge ports 33a, 33b are connected to liquid discharge mechanisms 34, 35, respectively.

[0029] The liquid discharge mechanisms 34 and 35 discharge the processing liquid collected in the two discharge ports 33 a and 33 b to the outside of the housing 30 .

[0030] The liquid discharge mechanism 34 has a recovery flow path 34b and a waste flow path 34c connected to the discharge port 33a via a flow path switch 34a. The flow path switch 34a switches the flow path into which the processing liquid can flow from the one discharge port 33a, between the recovery flow path 34b and the waste flow path 34c. The recovery flow path 34b is a flow path for reusing the processing liquid recovered from the one discharge port 33a, and is provided with a cooling buffer 34d for cooling the processing liquid. The waste flow path 34c is a flow path for discarding the processing liquid recovered from the one discharge port 33a.

[0031] The liquid discharge mechanism 35 has a waste flow path 35a connected to the other discharge port 33b. The waste flow path 35a is a flow path for disposing of the treatment liquid collected from the other discharge port 33b.

[0032] The processing liquid supply unit 32 a is provided so as to be able to supply the electroless plating solution and other processing liquids (e.g., an alkaline chemical solution, an oxidation promoter solution, a rinse solution, etc., which will be described later) as processing liquids to the discharge head 32 b and the discharge nozzle 32 c. This allows the processing liquid supply mechanism 32 to perform a cleaning process using a cleaning liquid, a rinsing process using a rinse liquid, or other liquid processing on the wafer W before or after applying the electroless plating solution to the wafer W.

[0033] 2 shows a simplified view of the treatment liquid supply mechanism 32, including one treatment liquid supply unit 32 a, one treatment liquid supply path 32 f, one discharge head 32 b, and one discharge nozzle 32 c. However, the number and configuration of the treatment liquid supply unit 32 a, the treatment liquid supply path 32 f, the discharge head 32 b, and the discharge nozzle 32 c are not limited.

[0034] For example, a plurality of processing liquid supply units 32a, processing liquid supply paths 32f, discharge heads 32b, and / or discharge nozzles 32c may be provided. In this case, for example, a dedicated processing liquid supply unit 32a, processing liquid supply path 32f, discharge head 32b, and / or discharge nozzle 32c may be provided for each of the plurality of types of processing liquids supplied from the processing liquid supply mechanism 32 to the wafer W. Alternatively, a dedicated processing liquid supply unit 32a, processing liquid supply path 32f, discharge head 32b, and / or discharge nozzle 32c may be provided only for one or more specific types of processing liquid. In this case, the processing liquid supply unit 32a, processing liquid supply path 32f, discharge head 32b, and / or discharge nozzle 32c are shared with the other types of processing liquid.

[0035] Next, the processing of the wafer W in the electroless plating processing unit will be described. The wafer W having the recesses formed therein is subjected to an appropriate pre-processing as needed. The pre-processing referred to here may be any known process that can be performed before the plating process, such as a silane coupling process or a seed layer formation process, as needed.

[0036] [Plating Process] Thereafter, while the wafer W held by the substrate rotating and holding mechanism 31 is rotated about a vertical axis, a plating solution at, for example, about 80°C is discharged from the discharge nozzle 32c for discharging the plating solution onto the central portion of the wafer W. The plating solution flows while spreading across the surface of the wafer W toward the peripheral edge so as to cover the entire surface of the wafer W. As a result, a plating layer is formed on the surface of the wafer W (e.g., bottom-up from the bottom of the recesses of the pattern) by electroless plating. The location where the plating layer is formed depends on the surface condition of the wafer W after pre-processing.

[0037] [Alkaline Chemical Liquid Supply Process] Next, while continuing to rotate the wafer W, the supply of the plating liquid is stopped, and an alkaline chemical liquid (ALK) is supplied to the center of the wafer W from the discharge nozzle 32c for discharging the alkaline chemical liquid. As the alkaline chemical liquid, for example, one obtained by mixing DIW with TMAH (tetramethylammonium hydroxide) as a pH adjuster to adjust the pH to about 8 to 14 can be used. This removes the plating liquid and reaction products remaining on the surface of the wafer W. At this time, as shown in FIG. 3A, for example, particulate metal residue M adheres to the surface of the wafer W or the surface of the plating layer.

[0038] [Oxidation-Promoting Liquid Supply Process] Next, while continuing to rotate the wafer W, the supply of the alkaline chemical liquid is stopped, and the oxidation-promoting liquid is supplied to the center of the wafer W from the discharge nozzle 32c for discharging the oxidation-promoting liquid. As the oxidation-promoting liquid, DIW (pure water) or hydrogen peroxide mixed with TMAH (tetramethylammonium hydroxide) as a pH adjuster to adjust the pH to about 6 to 7 can be used. The oxidation-promoting liquid oxidizes the surface of the metal residue M remaining on the surface of the wafer W (forming MOx: see FIG. 3B )), and also removes the alkaline chemical liquid remaining on the surface of the wafer W.

[0039] [Intermediate Drying Step] Next, while continuing to rotate the wafer W (preferably by increasing the rotation speed of the wafer W), the supply of the oxidation-promoting liquid is stopped. In other words, the wafer W is spin-dried (shaken off and dried). As a result, the oxidation-promoting liquid remaining on the surface of the wafer W is scattered outward from the wafer W by centrifugal force and removed from the surface, and the surface of the wafer W is exposed to the air surrounding the wafer W, which is an oxidizing atmosphere. This further advances the oxidation of metal residues remaining on the surface of the wafer W (growth of MOx: see FIG. 3(C)).

[0040] [Alkaline Chemical Liquid Supply Process] Next, while continuing to rotate the wafer W (returning the rotation speed of the wafer W to its original value), an alkaline chemical liquid is supplied to the center of the wafer W from the discharge nozzle 32c for discharging the alkaline chemical liquid. The alkaline chemical liquid can be the same as that used in the first alkaline chemical liquid supply process. As a result, the oxidized portion (MOx) of the metal residue, particularly that near the surface, dissolves in the alkaline chemical liquid, and the metal residue is detached from the surface of the wafer W (see FIG. 3(D)). The detached metal residue is washed away from the surface of the wafer W by the alkaline chemical liquid.

[0041] [Rinsing Process] Next, while continuing to rotate the wafer W, the supply of the alkaline chemical liquid is stopped and DIW is supplied as a rinsing liquid to the center of the wafer W from the discharge nozzle 32c for discharging the oxidation-promoting liquid. In other words, the wafer W is subjected to a DIW rinsing process. As a result, the alkaline chemical liquid remaining on the surface of the wafer W is removed.

[0042] [Final Drying Step] Next, while continuing to rotate the wafer W (preferably by increasing the rotation speed of the wafer W), the supply of the rinse liquid is stopped. In other words, the wafer W is spin-dried (shaken off and dried). As a result, the rinse liquid remaining on the surface of the wafer W is scattered outward from the wafer W by centrifugal force and removed from the surface, and the surface of the wafer W is dried. This completes the plating process for one wafer W.

[0043] The above embodiment can be modified as follows.

[0044] In the plating process consisting of the above-described series of steps, the initial alkaline chemical supply step may be omitted, and an oxidation-promoting liquid supply step may be performed after the plating process. This is because the metal residue removal effect of the alkaline chemical becomes high after the surface of the metal residue has been oxidized to a certain extent. However, adjusting the zeta potential in the initial alkaline chemical supply step may prevent particulate matter suspended in the plating solution at the end of the plating process (which continues to be present during the initial alkaline chemical supply step) from adhering to the wafer W. Whether or not to perform the initial alkaline chemical supply step may be determined depending on the expected effect of adjusting the zeta potential.

[0045] After the initial alkaline chemical supplying step (or after the plating treatment step if the initial alkaline chemical supplying step is skipped), a set of steps consisting of the oxidation promoting liquid supplying step, the intermediate drying step, and the alkaline chemical supplying step may be repeated multiple times, followed by a rinsing step and a final drying step. By repeating the oxidation and alkali treatment, even difficult-to-remove metal residues can be removed.

[0046] In one embodiment, all steps other than the plating step are room temperature processes, but are not limited to this.

[0047] An intermediate drying step may be performed while blowing air onto the surface of the rotating wafer W.

[0048] Instead of the shake-off drying, the intermediate drying step may be performed by scanning the surface of the wafer W with a discharge nozzle that discharges air in a band shape, such as an air knife. The final drying step may also be performed in the same manner as the intermediate drying step.

[0049] [Experiment 1] The following describes the results of an experiment to confirm the effects of the embodiment. Four processing conditions were set, and two wafers W were processed under each processing condition. Processing condition 1: Electroless Cu plating step → DIW rinse step → spin drying step Processing condition 2: Electroless Cu plating step → alkaline chemical solution supply step (15 seconds) → DIW rinse step (15 seconds) → spin drying step Processing condition 3: Electroless Cu plating step → alkaline chemical solution supply step (90 seconds) → DIW rinse step (15 seconds) → spin drying step Processing condition 4: Electroless Cu plating step → alkaline chemical solution supply step (15 seconds) → "DIW rinse step (15 seconds) → spin drying step (intermediate drying step) → alkaline chemical solution supply step (15 seconds)" x 6 times → DIW rinse (15 seconds) → spin drying step (final drying step)

[0050] After processing, the number of particles having a size of 60 nm or more remaining on the surface of the wafer W (average of N=2) was as follows: Processing condition 1: 922 Processing condition 2: 622 Processing condition 3: 331 Processing condition 4: 153

[0051] From the above, it can be seen that the number of particles can be significantly reduced by repeating the DIW rinse (15 seconds) → spin drying → alkaline chemical treatment (15 seconds).

[0052] [Experiment 2] Four processing conditions were set for a test piece having a Cu film formed on its surface by PVD processing, and an experiment was conducted to examine the amount of reduction in Cu film thickness after processing under each processing condition. Processing condition 1: DIW rinse step → spin drying step Processing condition 2: Alkaline chemical solution supply step (15 seconds) → DIW rinse step (15 seconds) → spin drying step Processing condition 3: Alkaline chemical solution supply step (90 seconds) → DIW rinse step (15 seconds) → spin drying step Processing condition 4: Alkaline chemical solution supply step (15 seconds) → "DIW rinse step (15 seconds) → spin drying step (intermediate drying step) → Alkaline chemical solution supply step (15 seconds)" x 6 times → DIW rinse step (15 seconds) → spin drying step (final drying step)

[0053] The experimental results were as follows: Processing condition 1: ±0 (reference value) Processing condition 2: −0.31 nm Processing condition 3: −1.04 nm Processing condition 4: −1.86 nm

[0054] From the above, it was found that by oxidizing the surface of the Cu film by DIW rinsing and spin drying, the surface of the Cu film can be significantly removed by treatment with an alkaline chemical solution. In other words, it was found that metal residues derived from Cu plating can be efficiently removed by performing treatment with an alkaline chemical solution after DIW rinsing and spin drying.

[0055] As can be seen from process condition 4 of Experiment 2 above, the thickness of the surface oxide layer formed by performing one rinsing step (DIW rinsing step) and one intermediate drying step is approximately 0.3 nm. The oxidizing properties of the processing fluid to which the surface of the wafer W is exposed in the rinsing step (here, pure water into which oxygen from the air is dissolved after being discharged) and the processing fluid to which the surface of the wafer W is exposed in the intermediate drying step (here, air) are sufficient to form a surface oxide layer of this thickness. This is because using a processing fluid with too high an oxidizing property would cause excessive damage to the plating layer.

[0056] The plating layer formed by the plating process is, for example, a Cu plating layer. However, the material of the plating layer is not limited to Cu, and any metal may be used as long as it is oxidized by a relatively weakly oxidizing fluid such as DIW or air to form an oxide, and the oxide can be easily dissolved in an alkaline chemical solution. Examples of such metals include Co, Ru, Mo, and Ni.

[0057] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0058] The substrate is not limited to a semiconductor wafer, but may be any other type of substrate used in the manufacture of semiconductor devices, such as a glass substrate or a ceramic substrate.

Claims

1. A plating method comprising: a plating process step of supplying a plating solution to a substrate to form a plating film on the surface of the substrate; an oxidation-promoting solution supplying process step of supplying an oxidation-promoting solution to the substrate to oxidize metal residues on the surface of the substrate resulting from the plating process; an intermediate drying process step of drying the substrate after the oxidation-promoting solution supplying process to promote oxidation of the metal residues; an alkaline-based chemical solution supplying process step of supplying an alkaline-based chemical solution to the substrate after the intermediate drying process to remove the oxidized metal residues; a rinsing process step of supplying a rinsing solution to the substrate after the alkaline-based chemical solution supplying process to remove the alkaline-based chemical solution from the substrate; and a final drying process of drying the substrate after the rinsing process.

2. The plating method according to claim 1, wherein the oxidation promoting liquid supplying step, the intermediate drying step, and the alkaline chemical liquid supplying step are each repeated in this order at least twice between the plating step and the rinsing step.

3. The plating method according to claim 1, wherein the oxidation-promoting liquid is pure water.

4. The plating method according to claim 1, wherein the oxidation-promoting liquid is a mixture of hydrogen peroxide and an alkaline pH adjuster.

5. The plating method according to claim 1, wherein the intermediate drying step is performed by spin drying.

6. The plating method according to claim 1, wherein air is blown onto the surface of the substrate during the intermediate drying step.

7. The plating method according to claim 1, further comprising the step of supplying an alkaline chemical solution to the substrate after the plating step and before the oxidation-promoting solution supply step.

8. A plating processing apparatus comprising: a substrate holding unit that holds a substrate; a processing liquid supply mechanism that supplies a processing liquid required for plating to the substrate held by the substrate holding unit; and a control unit that controls the operation of the plating processing apparatus to perform the plating processing method described in any one of claims 1 to 7.

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