JP2013194305A - Plating apparatus and plating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plating apparatus capable of suppressing deterioration in in-plane uniformity, and to provide a method of the plating apparatus.SOLUTION: A plating apparatus includes: a plating tank; an anode; an adjusting member; and a reversing mechanism. The plating tank is fed with a plating liquid. The anode is arranged at the inside of the plating tank. The adjusting member is arranged at the inside of the plating tank and adjusts an electric field between the anode and a cathode to form into the substrate to be plated. The reversing mechanism reverses the flow of a plating liquid in the plating tank.

Description

  Embodiments described herein relate generally to a plating apparatus and a plating method.

  In recent years, new microfabrication techniques have been developed along with higher integration and higher performance of semiconductor integrated circuits (LSIs). In particular, recently, in order to achieve high speed LSI, the wiring material is changed from a conventional aluminum (Al) alloy to a low resistance copper (Cu) or Cu alloy (that is, a copper-containing material, hereinafter collectively referred to as Cu). ) Is moving forward. Since Cu is difficult to be finely processed by dry etching methods such as RIE (reactive ion etching) frequently used in the formation of Al alloy wiring, a Cu film is deposited on the insulating film subjected to the groove processing. The so-called damascene method, in which the Cu film other than the portion embedded in the groove is removed by a chemical mechanical polishing (CMP) method to form a buried wiring, is mainly used. Has been. In general, a Cu film is formed by forming a thin Cu seed layer by sputtering or the like, and then forming a laminated film having a thickness of about several hundreds of nanometers by electrolytic plating using the Cu seed layer as a cathode.

  In such an electroplating method, a negative voltage is applied to the outer periphery of the Cu seed layer using the Cu seed layer formed on the substrate surface as a cathode, so the center of the Cu seed layer is related to the electrical resistance of the Cu seed layer. There is a difference between the voltage between the part and the anode and the voltage between the peripheral part of the Cu seed layer and the anode. Therefore, if the plating process is performed while the voltage difference is generated in the Cu seed layer in this way, the thickness of the plated Cu film varies between the central portion and the peripheral portion, and in-plane uniformity cannot be maintained. End up. On the other hand, in the conventional plating apparatus, an adjustment plate (high resistance plate) having a plurality of holes for adjusting the electric field between the cathode and the anode is arranged, and the electric field between the central portion of the Cu seed layer and the anode is The electric field between the periphery of the Cu seed layer and the anode is adjusted to be uniform.

  However, in such a plating apparatus, in order to process a large number of substrates, if the plating process and the process standby until the next substrate are continuously repeated, bubbles generated during circulation of the plating solution maintain in-plane uniformity. For this reason, it accumulates at the bottom of the adjustment plate (high resistance plate) that has been installed. Then, the bubbles hinder the film formation current during the plating process of the substrate, thereby deteriorating the uniformity of the film formation surface, and there is a problem that it contributes to product defects. When removing such bubbles, the operation of the apparatus is stopped and maintenance is required, but this also causes a decrease in the apparatus operating rate. Avoidance is currently difficult, and immediate countermeasures are desired.

JP 2004-515918 A

  An object of the present invention is to provide a plating apparatus and method that can suppress deterioration of in-plane uniformity of the plating film thickness.

  The plating apparatus according to the embodiment includes a plating rod, an anode, an adjustment member, and a reverse rotation mechanism. A plating solution is supplied to the plating tank. The anode is disposed in the plating basket. The adjusting member is disposed in the plating tub and adjusts the electric field between the anode and the cathode to be plated. The reversing mechanism reverses the flow of the plating solution in the plating trough.

In the plating method of the embodiment, a plating solution is disposed from the anode side to the cathode side so as to pass through an adjusting member that adjusts an electric field between the anode and the cathode, which is disposed between the anode and the cathode to be plated. A plating process for forming a plating film on the substrate to be plated while supplying the plating solution, and after the plating process is finished, the plating solution passing through the adjusting member flows from the cathode side to the anode side. A step of reversing the flow of the plating solution,
It has.

It is process sectional drawing which shows the manufacturing method of the semiconductor device in 1st Embodiment. It is a flowchart figure which shows the principal part process of the plating method in 1st Embodiment. It is a conceptual diagram which shows an example of a structure of the plating apparatus and plating method in 1st Embodiment. It is a conceptual diagram which shows the plating solution reverse circulation processing method in 1st Embodiment. It is a figure which shows the result of having compared the in-plane uniformity by the implementation presence or absence of the foam removal process by 1st Embodiment. It is a flowchart figure which shows the principal part process of the plating method in 2nd Embodiment. It is a figure which shows an example of a structure of the adjustment board of the electric field between the anode and cathode in 2nd Embodiment. It is a conceptual diagram which shows an example of the foam removal process in 2nd Embodiment.

(First embodiment)
Hereinafter, it demonstrates using drawing.
FIG. 1 is a process cross-sectional view of the semiconductor device manufacturing method according to the first embodiment. FIG. 1 shows a process cross-sectional view including a process of forming a plating film by an electrolytic plating method when forming a wiring, for example. In FIG. 1A, an insulating film 220 is formed on a substrate 200 as an example of a base. As the insulating film 220, for example, a low-k film using a porous low dielectric constant insulating material is formed with a thickness of, for example, 200 nm. By forming the low-k film, an interlayer insulating film having a relative dielectric constant k of 3.0 or less can be obtained. For example, a silicon wafer having a diameter of 300 mm is used as the substrate 200. Here, the description of the formation of a device or the like located below the insulating film 220 is omitted.
Subsequently, in FIG. 1B, an opening 150 which is a wiring groove structure for forming a damascene wiring is formed in the insulating film 220 by a lithography process and a dry etching process. By removing the exposed insulating film 220 by anisotropic etching from the substrate 200 on which the resist film is formed on the insulating film 220 through a lithography process such as a resist coating process and an exposure process (not shown), the substrate The opening 150 can be formed substantially perpendicular to the surface of 200. For example, as an example, the opening 150 may be formed by a reactive ion etching method.
Next, after forming a barrier metal film (not shown) on the insulating film 220 including the inner wall of the opening 150, in FIG. 1C, as a seed film formation process, A seed film 250 is formed. Specifically, a Cu thin film as the seed film 250 is deposited (formed) on the insulating film 220 including the inner wall of the opening 150 where a barrier metal film (not shown) is formed by a physical vapor deposition (PVD) method such as sputtering. Let In FIG. 1D, as a plating process, a Cu film 260 (an example of a copper-containing film) is deposited on the entire surface including the inside of the opening 150 by an electrochemical growth method using electrolytic plating with the seed film 250 as a cathode electrode. . Here, for example, a Cu film 260 having a thickness of 800 nm is deposited, and after the deposition, annealing is performed at a temperature of, for example, 250 ° C. for 30 minutes.
Next, the Cu film 260 including the seed film 250 and the barrier metal film (not shown) to be a wiring layer deposited other than in the opening 150 on the substrate 200 is polished and removed by CMP, as shown in FIG. To flatten. As described above, damascene wiring can be formed. Hereinafter, the plating method in the plating step shown in FIG. 1 (d) will be described in detail.

  FIG. 2 is a flowchart showing main steps of the plating method according to the first embodiment. In FIG. 2, the plating method according to the first embodiment repeatedly performs a series of steps of a plating treatment step (S102) and a plating solution reverse circulation treatment step (S106).

  FIG. 3 is a conceptual diagram showing an example of the configuration of the plating apparatus and the plating method in the first embodiment. The plating apparatus 100 has, for example, a substantially cylindrical plating tank 102 in which a plating solution 101 is contained, and a holder 106 that is disposed above the plating tank 102 and detachably holds a substrate 300 with the plating surface facing downward. It has. As the plating solution 101, a solution containing copper sulfate as a main component and an additive may be used. An anode electrode (anode) 104 whose upper surface is exposed to the plating solution 101 is disposed at the bottom of the plating tank 102. As the anode electrode 104, for example, a soluble anode such as phosphorous copper may be used.

  Further, in the electroplating method, a negative voltage is applied to the outer peripheral portion of the Cu seed film 250 using the Cu seed film 250 formed on the substrate surface as a cathode electrode. Therefore, there is a difference between the voltage between the central portion of the Cu seed film and the anode electrode 104 and the voltage between the peripheral portion of the Cu seed film 250 and the anode electrode 104. In that case, the thickness of the plated Cu film 260 varies between the central portion and the peripheral portion, and the in-plane uniformity cannot be maintained. In order to solve this problem, in the plating apparatus 100, an adjustment plate (high resistance plate: an example of an adjustment member) 20 having a plurality of holes is parallel to the plating surface (or the surface of the anode electrode 104) of the substrate 300. And so as to be immersed in the plating solution 101. The adjustment plate 20 adjusts the electric field between the central portion of the Cu seed film 250 and the anode electrode 104 and the electric field between the peripheral portion of the Cu seed film 250 and the anode electrode 104 to be uniform. The size, number, arrangement position, and the like of the plurality of holes formed in the adjustment plate 20 may be adjusted as appropriate so that the electric field is uniform. Further, the plating solution 101 passes from the tank 114 in which the plating solution 101 is stored, through the flow path 120 (first flow path) by the pump 140, and from the adjustment plate 20 to the anode electrode 104 side (lower side of the adjustment plate 20). To the plating trough 102. A three-way valve 130 (switching valve) is arranged in the middle of the flow path 120, and connects the flow path 120a and the flow path 120b. A flow path 122 (second flow path) is connected to another connection port of the three-way valve 130.

  Then, the plating solution 101 supplied from the flow path 120 passes through the hole of the adjustment plate 20 and flows to the upper part of the plating rod 102. Then, the plating solution 101 overflowing from the inside of the plating tank 102 is discharged to the drain pot 110 disposed around the plating vessel 102, and returned from the drain pot 110 to the tank 114 through the flow path 112. In this way, the plating solution 101 circulates. The plating solution 101 returned to the tank 114 is returned to the tank 114 after component adjustment again by a plating solution management device (not shown). Further, the temperature of the plating solution 101 is controlled to, for example, 25 ° C. by the plating solution management apparatus in a circulated state.

  As the plating process (S102), the flow path 120b and the flow path 120a are opened by the three-way valve 130, and the connection to the flow path 122 is cut off. Then, the plating process is performed on the substrate 300 in a state where the plating solution 101 is circulated in the order of the drain pot 110, the flow path 112, and the tank 114. FIG. 3 shows a state in which the holder 106 holds the substrate 300 at a position where the substrate 300 is immersed in the liquid surface of the plating solution 101. In the holder 106, a cathode-side contact is connected to the outer peripheral portion of the seed film 250 on the surface of the substrate 300 in a region where the plating solution 101 is not touched. On the other hand, a contact on the anode side is connected to the anode electrode 104. When the surface of the substrate 300 is placed in the plating bath 102 containing the plating solution 101, it is preferable that the holder 300 is rotated to enter the bath while rotating the substrate 300. Then, the surface of the substrate 300 is immersed in the plating solution 101 while being rotated, and a current having a predetermined current density is passed using the anode electrode 104 as an anode (anode) and the seed film 250 of the substrate 200 serving as a plating surface as a cathode (cathode). Electrolytic plating is performed. Further, when entering the bath, it is more preferable to enter the bath in a state where the substrate 300 is inclined by a predetermined angle so that no air remains between the substrate 300 and the plating solution 101.

  And after completion | finish of plating, the board | substrate 300 is moved to a position higher than the liquid level of the plating solution 101 by moving the holder 106 to the upper part. Then, after the plating process is completed, the substrate 300 is removed from the holder 106, cleaned, etc., and then proceeds to the next step. Here, as shown in FIG. 3, when the plating solution 101 is circulated from the flow path 120 located below the adjustment plate 20 so as to be supplied into the plating rod 102 in order to perform the plating process, for example, a pump 140 is used. Bubbles 10 are generated due to cavitation or the like at this point, and the bubbles 10 enter the plating trough 102 from the flow path 120 and accumulate in the lower part of the adjustment plate 20. If the plating process is repeated for a large number of substrates 300 in this state, the bubbles 10 gradually increase. Finally, the in-plane uniformity of the plated substrate 300 is inhibited by inhibiting the film formation current during the plating process. It will deteriorate unacceptably.

  Therefore, in the first embodiment, the plating solution reverse circulation process step (S106), which is an example of the bubble removal process of the bubbles 10 accumulated in the lower part of the adjustment plate 20, is periodically performed between the plating processes on a large number of substrates 300. To implement. It is not necessary to specify the number of substrates 300 to be subjected to the plating process before the bubble removal process is performed, and the plating apparatus 100 can be used before there is a risk of malfunction due to the bubbles 10 accumulated in the lower part of the adjustment plate 20. However, the plating solution reverse circulation treatment step (S106) may be performed by selecting a time when the overly dense plating treatment is not required.

  FIG. 4 is a conceptual diagram showing a plating solution reverse circulation processing method in the first embodiment. After the completion of plating, the reversing mechanism reverses the flow of the plating solution 101 in the plating trough 102 with the holder 106 moved upward. As the reverse rotation mechanism, for example, a three-way valve 130, a flow path 122, and a pump 142 are provided. One of the flow paths 122 is connected to the three-way valve 130, and the other is a position opposite to the anode electrode 104 side with respect to the adjustment plate 20 of the plating rod 102, in other words, at the upper portion of the adjustment plate 20. 102. The pump 142 is disposed in the middle of the flow path 122. Specifically, the plating solution reverse circulation process operates as follows. The pump 140 is stopped (OFF), and the three-way valve 130 is switched from the flow path 120b connected to the pump 140 side to the flow path 122 connected to the pump 142 side. The pump 142 is driven to circulate the plating solution 101 in the order below the adjustment plate 20 of the plating rod 102, the flow path 120a, the three-way valve 130, the flow path 122, and the upper portion of the plating plate 102 above the adjustment plate 20. . Thus, the pump 142 passes through the flow path 120a, the three-way valve 130, and the flow path 122 so that the flow of the plating liquid 101 in the plating tank 102 is reversed from that during plating. Reverse cycle. In other words, the flow of the plating solution 101 is reversed so that the plating solution 101 passing through the adjusting plate 20 flows from the cathode side to the anode side. Due to such reverse circulation, the bubbles 10 accumulated at the lower part of the adjustment plate 20 are discharged from the flow path 120a together with the plating solution 101, and the position opposite to the anode electrode 104 side with respect to the adjustment plate 20 by the flow path 122. The plating solution 101 is supplied from the (above the adjusting plate 20) to the plating rod 102. Since the bubble 10 flows into the plating trough 102 on the liquid surface side from the adjustment plate 20, it can rise to the liquid surface without being shielded. Therefore, the bubble 10 can be extracted from the surface of the plating solution 101.

  In the example of FIG. 4, the flow path 122 is connected to the plating rod 102 at a position above the adjustment plate 20 and below the liquid surface of the plating solution 101, but is not limited thereto. The flow path 122 may be configured so that the plating solution 101 is supplied to the plating trough 102 from above the plating solution 101. However, as shown in FIG. 4, it is more preferable to supply the plating trough 102 at a position below the liquid surface of the plating solution 101 because it is difficult to mix new bubbles. Furthermore, since the position is lower than the surface of the plating solution 101, the flow path 122 is filled with the plating solution 101, which is more preferable in that priming water can be dispensed with when the pump 142 is driven.

  In the first embodiment, an air vent valve 146 is further arranged in the middle of the flow path 120 a between the plating rod 102 and the three-way valve 130. The bubbles 10 discharged from the flow path 120a together with the plating solution 101 are separated into air and water by the air vent valve 146 and discharged. Even when the air vent valve 146 is not disposed, the bubbles 10 accumulated in the lower portion of the adjustment plate 20 can be circulated to the liquid surface side of the plating solution 101 with respect to the adjustment plate 20 and extracted from the liquid surface of the plating solution 101. Although it is possible, by arranging the air vent valve 146, the foam removal can be further promoted. Further, by disposing the air vent valve 146 between the plating rod 102 and the three-way valve 130, even when the foam 10 is present in a large amount in the lower part of the adjustment plate 20 at the time of foam removal, the foam is placed in front of the pump 142. I can pull it out. Therefore, it is possible to avoid the risk that the bubble 10 is caught in the pump 142 and the circulation capacity is lowered. Further, the fine bubbles 10 can be eliminated by the air vent valve 146. As a result, by continuing to circulate the minute bubbles 10 in the liquid, it is possible to avoid the risk of finally causing bubbles formation at the lower part of the adjusting plate 20 again.

In FIG. 5, the result of having compared in-plane uniformity by the implementation presence or absence of the foam removal process by 1st Embodiment is shown. A continuous processing test of the substrate was performed when the bubble removal process according to the first embodiment was performed and when the bubble removal process according to the first embodiment was not performed. In-plane film thickness uniformity was confirmed at the initial stage, the 500th sheet, the 1000th sheet, and the 1500th sheet. In addition, the foam removal process by 1st Embodiment was implemented for every plating process of the board | substrate for 1 lot (25 sheets) here.
When the bubble removal process according to the first embodiment is not performed, the in-plane film thickness uniformity was within the allowable range (◯) at the initial stage and the 500th sheet, but the in-plane film thickness uniformity was at the 1000th sheet. The difference between the maximum film thickness and the minimum film thickness exceeded the allowable range (x). Therefore, the continuous processing test was interrupted, the adjustment plate was removed, the foam removal operation was performed, and the in-plane film thickness uniformity was kept within an allowable range, and then the continuous processing test was resumed. However, in the 1500th sheet, the in-plane film thickness uniformity deteriorated compared to the initial and 500th sheet, although it was within the allowable range (Δ). This is because bubbles generated during circulation of the plating solution stay on the adjusting plate, and the remaining bubbles combine to form large bubbles, thereby locally hindering the plating current between the anode and the substrate. It is thought that the thickness uniformity deteriorated. On the other hand, when the bubble removal process according to the first embodiment is performed, the in-plane film thickness uniformity is within an allowable range in all of the initial, 500th sheet, 1000th sheet, and 1500th sheet (◯). Thus, it was possible to stably maintain good in-plane uniformity.

  As described above, according to the first embodiment, even when a plating process is performed on a plurality of substrates, deterioration of in-plane uniformity due to generation of bubbles can be suppressed. In addition, maintenance work such as stopping the operation of the device, removing the adjustment plate, and removing bubbles is unnecessary, and continuously forms a plating film with good in-plane uniformity without significantly reducing the device operation rate. be able to.

(Second Embodiment)
In the first embodiment, the case where the bubbles accumulated in the lower part of the adjusting plate 20 are discharged from the lower side of the adjusting plate 20 by reversing the flow of the plating solution 101 has been described. In the second embodiment, the bubbles are further reduced. A configuration for improving the punching effect will be described. In the second embodiment, the configuration of the plating apparatus 100 is the same as that shown in FIGS. 3 and 4 except that a plurality of adjustment plates 20 (for example, two adjustment plates) are stacked. Further, points not particularly described are the same as those in the first embodiment.

  FIG. 6 is a flowchart showing the main steps of the plating method according to the second embodiment. In FIG. 6, in the plating method in the second embodiment, an opening area adjustment step (S100) is added before the plating treatment step (S102), and the plating treatment step (S102) and the plating solution reverse circulation treatment step (S106). 2 is the same as FIG. 2 except that an opening area expansion step (S104) is added.

  In the opening area adjustment step (S100), the overlapping positions of the two adjustment plates having a plurality of holes are relatively shifted to reduce the opening area of the opening that is opened by both of the adjustment plates. The position and size of the hole of each adjustment plate are controlled to a position where adjustment is possible.

  FIG. 7 is a diagram illustrating an example of the configuration of the adjustment plate for the electric field between the anode and the cathode in the second embodiment. FIG. 7A shows an example of a state in which the two adjustment plates 20 and 22 are overlapped. A plurality of holes 24 (openings) are formed in the adjustment plate 20, and similarly, a plurality of holes 26 (openings) are formed in the adjustment plate 22. The overlapping degree of the holes 24 and 26 can be adjusted by relatively rotating the two adjusting plates 20 and 22. FIG. 7A shows a case where the overlapping positions of the holes 24 and 26 are controlled at positions where the electric field can be adjusted during plating. The positions and sizes of the holes 24 and 26 of the adjustment plates 20 and 22 may be different as long as the opening area of the opening can be adjusted, but it is easier to control if they are formed in the same position and size. Minutes are preferred.

  A plating process (S102) is performed in the overlapping positional relationship between the adjusting plates 20 and 22. The content of the plating process (S102) may be the same as in the first embodiment.

  Next, as opening area expansion processing (S104), after the end of plating, the two adjustment plates 20 and 22 are relatively rotated as shown in FIG. This enlarges the opening area of the holes 24 and 26.

  FIG. 8 is a conceptual diagram illustrating an example of a bubble removal process according to the second embodiment. As shown in FIG. 8, in the state where the opening areas of the adjusting plates 20 and 22 are enlarged, the circulation of the plating solution 101 similar to that in the plating process (S102) is continued. As a result, although depending on the size of the bubbles 10a accumulated in the lower portions of the adjustment plates 20 and 22, the bubbles 10a that can pass through the widened openings are discharged from the openings above the adjustment plates 20 and 22. The The bubbles 10 b discharged above the adjustment plates 20 and 22 reach the liquid surface of the plating solution 101 and can be removed from the plating solution 101.

  Next, a plating solution reverse circulation process (S106) similar to that of the first embodiment is performed. In the plating solution reverse circulation treatment step (S106), the opening area of the adjusting plates 20 and 22 may be enlarged, or the opening area of the adjusting plates 20 and 22 may be reduced. It is preferable that the adjustment plates 20 and 22 be opened in an enlarged state because the load applied to the pump 142 can be reduced.

  As described above, in the second embodiment, the area of the opening formed by the adjustment plates 20 and 22 is variable. According to this 2nd Embodiment, while being able to exhibit the effect of 1st Embodiment, bubble removal can be further promoted.

  The embodiment has been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the sizes and positions of the holes 24 and 26 of the adjustment plates 20 and 22 may be adjusted as appropriate. Moreover, although the example mentioned above demonstrated the case where Cu film | membrane was formed into a film by the plating method, it does not restrict to this. Other plating films may be used. For example, it is suitable even when a nickel (Ni) film is formed by a plating method. Moreover, although the case where the upper surface of the plating cage | basket 102 was open | released was shown in the example mentioned above, it is not restricted to this, The case where a board | substrate is plated within the sealed plating cage | basket may be sufficient.

  In addition, the film thickness of the interlayer insulating film and the size, shape, number, and the like of the opening can be appropriately selected from those required for the semiconductor integrated circuit and various semiconductor elements.

  In addition, all plating apparatuses and plating methods that include the elements of the present invention and that can be appropriately modified by those skilled in the art are included in the scope of the present invention.

  Further, for the sake of simplicity of explanation, techniques usually used in the semiconductor industry, such as a photolithography process, cleaning before and after processing, are omitted, but it goes without saying that these techniques may be included.

10 foam, 20, 22 adjusting plate, 100 plating apparatus, 101 plating solution, 102 plating tank, 104 anode electrode, 120, 122 flow path, 130 three-way valve, 140, 142 pump, 146 air vent valve, 200, 300 substrate

Claims (5)

A plating tank to which a plating solution is supplied;
An anode disposed in the plating vessel;
An adjusting member that is disposed in the plating trough and adjusts the electric field between the anode and the cathode to be plated;
A first flow path for supplying a plating solution into the plating vessel from a position on the anode side with respect to the adjustment member;
A reversing mechanism for reversing the flow of the plating solution in the plating trough,
With
The reverse mechanism is
A switching valve disposed in the middle of the first flow path;
A second flow path connected to the switching valve and supplying a plating solution from the position opposite to the anode side to the adjustment member to the plating rod;
Arranged in the middle of the second flow path, through the first flow path, the switching valve, and the second flow path, so as to reverse the flow of the plating solution in the plating trough at the time of plating. A pump for circulating the plating solution in the plating tank;
Have
In the middle of the first flow path, further comprising an air vent valve disposed at a position between the switching valve and the plating trough,
A plating apparatus, wherein a plurality of openings are formed in the adjustment member, and an area of the plurality of openings is variable. A plating tank to which a plating solution is supplied;
An anode disposed in the plating vessel;
An adjusting member that is disposed in the plating trough and adjusts the electric field between the anode and the cathode to be plated;
A reversing mechanism for reversing the flow of the plating solution in the plating trough,
A plating apparatus characterized by comprising: A first flow path for supplying a plating solution into the plating vessel from a position on the anode side with respect to the adjustment member;
The reverse mechanism is
A switching valve disposed in the middle of the first flow path;
A second flow path connected to the switching valve and supplying a plating solution from the position opposite to the anode side to the adjustment member to the plating rod;
Arranged in the middle of the second flow path, through the first flow path, the switching valve, and the second flow path, so as to reverse the flow of the plating solution in the plating trough at the time of plating. A pump for circulating the plating solution in the plating tank;
The plating apparatus according to claim 2, comprising:   The plating apparatus according to claim 3, further comprising an air vent valve disposed in the middle of the first flow path and between the switching valve and the plating trough. The plating solution is supplied from the anode side to the cathode side so as to pass through an adjustment member that adjusts the electric field between the anode and the cathode, which is disposed between the anode and the cathode to be plated. A plating process for forming a plating film on the plating substrate;
A step of reversing the flow of the plating solution so that the plating solution passing through the adjusting member flows from the cathode side to the anode side after the plating process is completed;
A plating method characterized by comprising:

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