JP4908380B2 - Electroplating anode and electroplating equipment - Google Patents

Description

  The present invention relates to an electroplating apparatus for performing electroplating on the surface (surface to be plated) of a substrate, in particular, a conductor (wiring material) embedded in a fine wiring pattern provided on the surface of a substrate such as a semiconductor wafer, and a package The present invention relates to an anode used in an electroplating apparatus for forming bumps and the like that are electrically connected to the electrodes and the like, and an electroplating apparatus having the anode.

  Conventionally, the thickness of a plating film formed by electroplating on the surface (surface to be plated) of a substrate tends to be gradually thicker toward the outer peripheral portion of the substrate, with the central portion of the substrate being thin. This is because (1) the potential line coming out from the anode goes around the outer periphery of the substrate serving as the cathode, and (2) the cathode using the current-carrying layer as the cathode in contact with the current-carrying layer such as the seed layer on the substrate surface. This is because the contact is generally disposed on the outer peripheral portion of the substrate, and therefore, at the center of the substrate, the current value is lowered due to the sheet resistance of the conductive layer immediately after the start of plating.

  In order to correct variations in the thickness of the plating film formed on the substrate surface, it is widely performed to insert a shielding plate between the anode and the cathode (substrate) to deform the electric field. However, even if a shielding plate is used, the phenomenon that the potential line wraps around the outer periphery of the substrate has not been completely eliminated, and for example, the material (metal) of the plating film formed by electroplating is made of lead. In order to shift to lead-free, it is necessary to further improve the in-plane uniformity of the plating film thickness.

  In order to improve the in-plane uniformity of the thickness of the plating film formed on the surface of the substrate, the applicant configures the anode from a plurality of divided anodes, and individually connects each of these divided anodes to a plating power source. What was made was proposed (refer patent document 1). In addition, as an electroplating apparatus using an anode with a special configuration, a plurality of soluble anodes having different metal compositions and capable of flowing currents are immersed in the plating solution so that the alloy components are uniformly distributed on the substrate surface. Proposed a method capable of forming an appropriate plating film (see Patent Document 2). Furthermore, an anode is proposed in which a plate-like soluble anode and an insoluble anode are superposed so that a normal electric field can always be formed even when the soluble anode is dissolved (see Patent Document 3). ).

JP 2002-129383 A Japanese Patent Laid-Open No. 11-209900 JP-A-11-209898

However, as in the invention described in Patent Document 1, when the anode is composed of a plurality of divided anodes and a plating power source is individually connected to each divided anode, the apparatus becomes complicated, leading to an increase in the size of the apparatus, This will increase costs. Incidentally, patented invention described in Documents 2 and 3 do not have to improve in-plane uniformity of a plated film formed on the surface of the base plate (surface to be plated).

  The present invention has been made in view of the above circumstances, and has a relatively simple configuration, and controls the current flowing through the inside without increasing the number of plating power sources. An object of the present invention is to provide an anode for electroplating capable of forming a plating film with improved in-plane uniformity of film thickness on the surface (surface to be plated), and an electroplating apparatus having the anode.

According to the first aspect of the present invention, the peripheral portion of the surface to be plated is brought into contact with the cathode contact so as to be immersed in the plating solution and opposed to the substrate disposed vertically, and is immersed vertically in the plating solution. An anode for electroplating, in which a voltage is applied between the cathode contact and the surface to be plated to perform electroplating, the first insoluble anode made of a first insoluble material, and the first The second insoluble anode is concentrically surrounded by the second insoluble anode while the second insoluble anode composed of the second insoluble material having a higher oxygen generation overvoltage than the insoluble material is electrically connected to each other. An anode for electroplating characterized in that it is surrounded and arranged in a plane.

  An insoluble anode composed of an insoluble material having a low oxygen generation overvoltage has a lower resistance than an insoluble anode composed of an insoluble material having a high oxygen generation overvoltage. For this reason, by combining insoluble anodes made of insoluble materials having different oxygen generation overvoltages to form one anode, different values of current can flow through the anode connected to one plating power source.

The pre-Symbol first insoluble anode and the second insoluble anodes, the more that the first of the surrounding insoluble anodes second insoluble anode is arranged concentrically surrounding, concentric current flowing in the anode Can be controlled. The concentric shape may be circular or rectangular.

The first insoluble material constituting the front Symbol first insoluble anode, compared by oxygen overvoltage than the second insoluble material forming the second insoluble anode is low, the anode consists of a single material Thus, it is possible to increase the value of the current flowing through the central portion of the substrate disposed facing the anode.

The invention according to claim 2 is characterized in that the first insoluble anode is made of iridium oxide or ruthenium oxide, and the second insoluble anode is made of platinum. It is.
According to a third aspect of the present invention, there is provided an anode for electroplating disposed in a plating solution facing a surface to be plated of a substrate, comprising a first insoluble anode composed of iridium oxide or ruthenium oxide, and platinum. The second insoluble anode is electrically connected to each other, and the periphery of the first insoluble anode is concentrically surrounded by the second insoluble anode and arranged in a plane. The anode.
The invention according to claim 4 is the anode for electroplating according to any one of claims 1 to 3, wherein the anode is formed in a shape similar to the shape of the surface to be plated of the substrate.
Thereby, the anode shape can be optimized in accordance with the shape (pattern) of the surface to be plated.

The invention according to claim 5 is a plating bath for holding a plating solution, a substrate holder for holding a substrate and bringing a surface to be plated into contact with the plating solution in the plating bath, and a plating solution in the plating bath. A plating power source for applying a voltage between the anode according to any one of claims 1 to 4 and the substrate and the anode, which is disposed opposite to a surface to be plated of the substrate held by the substrate holder. And an electroplating apparatus.

  According to the electroplating anode of the present invention, the surface of the substrate (covered) is arranged with a relatively simple configuration and controls the current flowing inside without increasing the number of plating power sources. A plating film with improved in-plane uniformity of film thickness can be formed on the plating surface.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention are described with reference to the drawings. In the following examples, the same or corresponding members are denoted by the same reference numerals, and redundant description is omitted.
FIG. 1 shows an electroplating apparatus according to an embodiment of the present invention. This electroplating apparatus is a so-called cup-type electroplating apparatus, and is disposed below the substrate holder 10 and a substrate holder 10 that can be moved up and down to detachably hold the substrate W with its surface (surface to be plated) facing downward. The plating tank 12 is provided.

  The substrate holder 10 is connected to the lower end of the rotating shaft 16 that rotates as the motor 14 rotates, and a seal ring 18 that presses against the lower peripheral edge of the substrate W to seal the lower peripheral surface, and the seal ring. The cathode contact 20 is located outside the contact 18 and contacts a current-carrying layer such as a seed layer formed on the surface of the substrate W to feed power to the current-carrying layer.

  The plating tank 12 is held inside while circulating the plating solution Q, and plating is performed by bringing the surface (lower surface) of the substrate W held by the substrate holder 10 into contact with the plating solution Q. One end of the circulation pipe 24 is connected to the bottom of the overflow tank 22, and the other end of the circulation pipe 24 is connected to the side of the plating tank 12. In the circulation pipe 24, a circulation pump 26, a temperature controller 28, and a filter 30 are sequentially arranged from the overflow tank 22 side. As a result, the plating solution Q in the plating tank 12 sequentially passes through the temperature controller 28 and the filter 30 and returns to the plating tank 12 and circulates as the circulation pump 26 is driven.

  At a position immersed in the plating solution Q inside the plating tank 12, a disc-shaped anode 32 along the shape of the substrate W is held by the anode holder 34 and arranged horizontally. As shown in detail in FIG. 2, the anode 32 in this example is a circular first insoluble anode 36 composed of a first insoluble material having a lower oxygen generation overvoltage (than the second insoluble material); It has a second insoluble anode 38 in the form of a flat ring made of a second insoluble material having a higher oxygen generation overpotential (than that of the first insoluble material). The first insoluble anode 36 and the second insoluble anode 38 are arranged concentrically around the first insoluble anode 36 and surrounded by the second insoluble anode 38, and the outer peripheral end face of the first insoluble anode 36. And the outer peripheral end face of the second insoluble anode 38 come into contact with each other and are arranged in a planar shape so as to be conductive, and are housed in the anode holder 34.

Examples of the first insoluble material whose oxygen generation overvoltage is lower (than the second insoluble material) include iridium oxide and ruthenium oxide. An example of the second insoluble material having a higher oxygen generation overvoltage (than the first insoluble material) is platinum.
In this example, the anode holder 34 is provided. However, the anode holder 34 is provided by fitting the first insoluble anode 36 into the second insoluble anode 38 by shrink fitting. Instead, the first insoluble anode 36 and the second insoluble anode 38 may be electrically connected. The same applies to the following.

  During plating, the cathode contact 20 is connected to the cathode of a rectifier 40 as a plating power source, and the anode 32 is connected to the anode of a rectifier (plating power source) 40. Then, the lower surface of the peripheral portion is sealed with a seal ring 18, the cathode contact 20 is brought into contact with a current-carrying layer such as a seed layer on the surface, the substrate holder 10 holding the substrate W is lowered, and the cathode contact 20 is rectified (plating power source). ) The anode 32 is connected to the anode of the rectifier (plating power source) 40 while the anode 32 is connected to the anode of the rectifier (plating power source) 40, and the contact layer is brought into contact with the cathode contact by bringing the conductive layer on the surface of the substrate W into contact with the plating solution Q in the plating tank 12 Then, a plating film is formed on the surface of the current-carrying layer that becomes the cathode.

  In the plating apparatus, the total potential of the anode potential, the cathode potential, and the plating solution potential is equal in any path. The cathode potential is related to the resistance (sheet resistance) of the current-carrying layer that is in contact with the cathode contact such as the seed layer, the anode potential is related to the anode resistance, and the plating solution potential is related to the plating solution resistance.

  As in this example, when a cathode contact is brought into contact with the current-carrying layer at the peripheral edge of the substrate to make the current-carrying layer a cathode, the resistance (sheet resistance) of the current-carrying layer gradually increases from the outer periphery to the center of the substrate. The current value flowing through the current-carrying layer gradually decreases. From these relationships, the current value is low in the central portion of the energization layer (cathode), and the current value is high in the peripheral portion. As a result, the thickness of the plating film formed on the surface of the energization layer (cathode) is It is thin at the center of the substrate and gradually increases toward the outer periphery.

  An insoluble anode made of an insoluble material having a low oxygen generation overvoltage has a lower resistance than an insoluble anode made of an insoluble material having a high oxygen generation overvoltage, and an insoluble anode made of an insoluble material having a high oxygen generation overvoltage is an insoluble material having a low oxygen generation overvoltage. It has a higher resistance than an insoluble anode made of Therefore, as in this example, the first insoluble anode 36 made of the first insoluble material having a lower oxygen generation overvoltage (than the second insoluble material) and the oxygen generation overvoltage (in comparison with the first insoluble material). When the anode 32 is configured by concentrically arranging the second insoluble anode 38 made of a high second insoluble material and surrounding the first insoluble anode 36 by the second insoluble anode 38, the anode 32 The anode potential at the central portion corresponding to the first insoluble anode 36 is low, and the anode potential at the peripheral portion corresponding to the second insoluble anode 38 is high. Accordingly, since the anode potential in the anode 32 is different, a potential difference occurs in the cathode potential even in the opposite conductive film (cathode), the cathode potential is low in the periphery of the conductive film (cathode), and the cathode potential is in the center. Get higher.

  As described above, when an anode made of a single material is used, the current distribution in the cathode tends to be higher in the peripheral part and lower in the central part. By forming a single anode 34 by combining the insoluble anodes 36 and 38, a plating film with reduced in-plane uniformity is formed on the surface of the cathode (current-carrying film) while suppressing variations in current distribution in the cathode. It becomes possible to do.

  In the above example, the anode of one rectifier (plating power source) 40 is connected to the anode 32 in which the first insoluble anode 36 and the second insoluble anode 38 are electrically connected to each other. As shown, the anodes of the separate rectifiers (plating power supplies) 40a and 40b may be connected to the first insoluble anode 36 and the second insoluble anode 38. Thereby, by performing fine adjustment of the value of the current flowing through the anode 32, the difference in anode potential can be obtained more than the difference in oxygen generation potential.

  In addition, as shown in FIG. 4, the variable resistor 42a is provided in the lead connecting the rectifier (plating power source) 40 and the first insoluble anode 36, and the variable resistor 42a is provided in the lead connecting the rectifier (plating power source) 40 and the second insoluble anode 38. Further, the variable resistors 42b may be interposed, and the current values of the first insoluble anode 36 and the second insoluble anode 38 may be controlled by one rectifier (plating power source) 401. Thereby, the difference in anode potential can be obtained more than the difference in oxygen generation potential.

  Further, as shown in FIGS. 5 and 6, when the anode 32 and the substrate W are disposed opposite to each other on the first soluble anode 36 located in the center, the bulge protrudes conically toward the substrate W. A protruding portion 36a may be provided. As a result, the number of potential lines at the center of the first soluble anode 36 close to the surface of the substrate W is maximized, and the potential lines to the energization film such as the seed layer serving as the cathode on the surface of the substrate W are also connected to the cathode ( It becomes the maximum at the center of the conductive film. During normal plating, potential lines concentrate on the outer periphery of the cathode, and the thickness of the plating film formed on the outer periphery tends to be thicker than other parts. By making the potential line maximum at the center of the film, the thickness of the plating film formed at the center of the anode can be increased and the in-plane uniformity of the film thickness can be improved.

  As shown in FIG. 7, when the anode 32 and the substrate W are disposed opposite to each other on the first soluble anode 36 located in the center, a bulging portion 36b that protrudes in a columnar shape toward the substrate W is provided. May be provided.

In each of the above examples, one anode is configured by combining insoluble anodes made of insoluble materials having different oxygen generation overpotentials. However, one anode may be configured by combining a soluble anode and an insoluble anode. . This is because the dissolution potential of the metal in the soluble anode is smaller than the oxygen generation overvoltage in the insoluble anode, and the soluble anode has a lower anode potential than the insoluble anode. For example, when tin (Sn) is used for the soluble anode, the dissolution potential of tin is Sn → Sn ²⁺ : −0.14 V, and when platinum (Pt) is used for the insoluble anode, the oxygen generation overvoltage of platinum is + 0.6V.

  For this reason, for example, in the cathode 32 shown in FIGS. 1 to 6, a soluble anode may be used instead of the first insoluble anode 36, and any insoluble anode may be used instead of the second insoluble anode 38. This also makes it possible to form a plating film with improved in-plane uniformity on the surface of the cathode (current-carrying film) while suppressing variations in the current distribution in the cathode, as described above.

  FIG. 8 shows another anode 32a. In this example, the anode 32a is planar and concentric with the first insoluble anode 44a, the second insoluble anode 44b and the third insoluble anode 44c made of insoluble materials having different oxygen generation overvoltages being connected to each other. It is arranged and arranged. The first insoluble anode 44a located at the center is an insoluble material having the lowest oxygen generation overvoltage, and the third insoluble anode 44c located at the outer periphery is an insoluble material having the highest oxygen generation overvoltage and is located at the center. The second insoluble anode 44b is made of an insoluble material having an intermediate oxygen generation overvoltage.

  According to this example, the anode potential at the center corresponding to the first insoluble anode 44a of the anode 32a is the lowest, the anode potential at the outer periphery corresponding to the third insoluble anode 44c is the highest, and the second The anode potential at the intermediate portion corresponding to the insoluble anode 44b becomes an intermediate value. As a result, it is possible to form a plating film that further improves in-plane uniformity on the surface of the cathode (current-carrying film) while suppressing variations in the current distribution in the cathode disposed opposite to the anode 32a. Become.

  FIG. 9 shows still another anode 32b. In the anode 32b of this example, a second insoluble anode 46b made of an insoluble material having a high oxygen generation overvoltage is arranged around a circular first insoluble anode 46a made of an insoluble material having a low oxygen generation overvoltage. Furthermore, a large number of first insoluble anodes 46a having a small diameter made of an insoluble material having a low oxygen generation overvoltage are arranged at equal intervals along the circumferential direction at the peripheral edge of the second insoluble anode 46b. ing. The first insoluble anode 46a and the third insoluble anode 46c may be made of the same material or different materials.

  According to this example, the plating film formed on the peripheral edge of the substrate facing the third insoluble anode 46c can be made thicker than other parts. Thus, for example, it is possible to cope with a case where it is desired to increase the thickness of the plating film formed on the peripheral edge of the substrate in addition to the same pattern due to the pattern arrangement in the substrate.

  FIG. 10 shows still another anode 32c. The anode 32a is made of an insoluble material having a low oxygen overvoltage in a region facing the dense region 48a of the anode 32a when the pattern of the surface to be plated on the surface of the substrate W includes the dense region 48a and the rough region 48b. One insoluble anode 50a and a second insoluble anode 50b made of an insoluble material having a high oxygen generation overvoltage are arranged in a region facing the rough region 48b of the anode 32a.

According to this example, for example, when the pattern of the surface to be plated is dense and dense, by changing the configuration of the anode according to the density of the pattern, the surface of the film thickness is not affected by the density of the pattern of the surface to be plated. A plating film with improved internal uniformity can be formed on the surface of the surface to be plated.
Even in this example, a soluble anode may be used instead of the first insoluble anode 50a, and any insoluble anode may be used instead of the second insoluble anode 50b.

  In each of the above examples, a plating film is formed on the surface of a circular substrate (surface to be plated) such as a semiconductor wafer. Therefore, a circular one is used as the anode. For example, when plating is performed on a rectangular substrate surface such as a glass substrate, a rectangular anode may be used as shown in FIG.

  That is, the anode 52 shown in FIG. 11A has a rectangular shape and is made of an insoluble material having a high oxygen generation overvoltage around the first insoluble anode 54a made of an insoluble material having a low oxygen generation overvoltage located in the center. A rectangular frame-shaped second insoluble anode 54b is arranged. The anode 52a shown in FIG. 11 (b) has a rectangular shape and is made of an insoluble material having an intermediate oxygen generation overvoltage around the first insoluble anode 56a made of an insoluble material having the lowest oxygen generation overvoltage located in the center. A rectangular frame-shaped second insoluble anode 56b is arranged, and a rectangular frame-shaped third insoluble anode 56c made of an insoluble material having the highest oxygen generation overvoltage is arranged around the second insoluble anode 56b. It is configured. The anode 52b shown in FIG. 11 (c) has a rectangular shape and a rectangular frame made of an insoluble material having a high oxygen generation overvoltage around the first insoluble anode 58a made of an insoluble material having a low oxygen generation overvoltage located in the center. A second insoluble anode 58b having a rectangular shape is disposed, and a plurality of rectangular third insoluble anodes 58c made of an insoluble material having a low oxygen generation overvoltage are disposed at the periphery of the second insoluble anode 58b. ing.

  FIG. 12 shows an electroplating apparatus according to another embodiment of the present invention. This plating apparatus is a so-called dip type electroplating apparatus, and includes a substrate holder 70 that can be moved up and down to detachably hold a substrate W, and a plating tank 72 that is disposed below the substrate holder 70. The substrate holder 70 is configured to move up and down with the substrate W standing in the vertical direction so that the substrate W is immersed in the plating solution Q in the plating tank 72. And a cathode contact for contacting the current-carrying layer such as a seed layer on the substrate surface outside the seal ring and supplying power to the current-carrying layer.

  The plating tank 72 has an overflow tank 74 on the outer peripheral portion. One end of the circulation pipe 76 is connected to the bottom of the overflow tank 74, and the other end of the circulation pipe 76 is connected to the bottom of the plating tank 74. In the circulation pipe 74, a circulation pump 78, a temperature controller 80, and a filter 82 are sequentially arranged from the overflow tank 74 side. As a result, the plating solution Q in the plating tank 72 passes through the temperature controller 80 and the filter 82 in order as the circulation pump 78 is driven, and returns to the plating tank 72 and circulates.

  When the substrate holder 70 is lowered in the plating tank 72 and the substrate W held by the substrate holder 70 is immersed in the plating solution Q in the plating tank 72, the substrate is immersed in the plating solution Q facing the surface of the substrate W. The anode 86 is disposed at the position where it is held by the anode holder 84. Then, as shown in FIG. 14, a shielding plate 88 having an opening 88a for adjusting the electric field, which is located between the substrate W and the anode 86 and has an outer diameter substantially along the outer shape of the substrate W, A paddle 90 that moves in parallel and stirs the plating solution Q is disposed.

  As shown in FIG. 13, the anode holder 84 has a ring-shaped anode band 96 connected to the conduction portion 94 at the end of the support bar 92 exposed to the outside of the plating tank 72. As shown in FIG. 13, the anode 86 includes a circular first insoluble anode 98 made of a first insoluble material having a lower oxygen generation overvoltage (than the second insoluble material), and an oxygen generation overvoltage (first It has a second insoluble anode 100 in the form of a flat ring made of a second insoluble material that is higher (than one insoluble material). The first insoluble anode 98 and the second insoluble anode 100 are arranged concentrically around the first insoluble anode 98 so as to surround the second insoluble anode 100, and the outer peripheral end face of the first insoluble anode 98. And the outer peripheral end surface of the second insoluble anode 100 are in contact with each other and are arranged on a flat surface so as to be conductive, and are held by an anode band 96.

  At the time of plating, as shown in FIG. 12, the cathode contact of the substrate holder 70 is connected to the cathode of the rectifier 102 as a plating power source, and the anode 86 is connected to the rectifier (plating power source) 102 through the conduction portion 94 and the anode band 96. Connected to the anode. Then, the peripheral edge is sealed with a seal ring, the cathode contact is brought into contact with a current-carrying layer such as a seed layer on the surface and the substrate holder 70 holding the substrate W is lowered in a vertical state, and the cathode contact of the substrate holder 70 is rectified. While the anode 86 is connected to the cathode of the (plating power source) 102 and the anode 86 of the rectifier (plating power source) 102, the surface of the substrate W is opposed to the anode 86, and the plating solution is passed through the paddle 90 as necessary. By stirring Q, a plating film is formed on the surface of the conductive layer that comes into contact with the cathode contact and becomes the cathode.

  Even in this example, similarly to the above, by forming one anode 86 by combining insoluble anodes 98 and 100 made of insoluble materials having different oxygen generation overvoltages, variation in current distribution in the cathode is suppressed, It is possible to form a plating film with improved in-plane uniformity on the surface of the cathode (conducting film).

  As shown in FIG. 15, a predetermined region in the peripheral portion of the second insoluble anode 100 may be covered with a flat ring-shaped anode mask 104 to arbitrarily determine the opening diameter of the anode 86.

  In the above example, a plating film is formed on the surface of a circular substrate (surface to be plated) such as a semiconductor wafer. For this reason, a circular one is used as the anode 86. For example, when plating is performed on a rectangular substrate surface such as a glass substrate, a rectangular anode 86a may be used as shown in FIG. That is, the anode 86a has a rectangular shape and a rectangular frame-shaped second made of an insoluble material having a high oxygen generation overvoltage around the first insoluble anode 106a made of an insoluble material having a low oxygen generation overvoltage located in the center. The insoluble anode 106b is arranged.

  In such a rectangular anode 86a, for example, as shown in FIG. 17, the anode 86a is sandwiched from the left and right by the side frame 108 of an anode holder having a pair of side frames 108 arranged on both sides of the anode 86a. 86a is held, and through this side frame 108, conduction with the anode 86a is established.

It is a vertical front view which shows the outline | summary of the electroplating apparatus of embodiment of this invention. It is a top view of the anode of the electroplating apparatus shown in FIG. It is a top view which shows the other conduction example in the anode of the plating apparatus shown in FIG. It is a top view which shows the further another example of conduction in the anode of the plating apparatus shown in FIG. It is a perspective view shown with the modification of the anode of the plating apparatus shown in FIG. It is a figure which shows the electric potential line generate | occur | produced between an anode and a board | substrate when performing electroplating using the anode shown in FIG. It is a perspective view shown with the other modification of the anode of the plating apparatus shown in FIG. It is a top view which shows the other example of an anode. It is a top view which shows the other example of an anode. It is a schematic perspective view which shows the other example of an anode. It is a top view which shows the other example of an anode. It is a vertical front view of the outline of the electroplating apparatus of other embodiment of this invention. It is a front view which shows the substrate holder of the electroplating apparatus shown in FIG. It is a front view which shows the shielding board of the electroplating apparatus shown in FIG. It is a front view which shows the other example of the substrate holder of the electroplating apparatus shown in FIG. It is a front view which shows the other example of an anode. FIG. 17 is a front view showing a state where the anode shown in FIG. 16 is held by the side frame of the substrate holder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate holder 12 Plating tank 18 Seal ring 20 Cathode contact 22 Overflow tank 24 Circulation piping 32, 32a, 32b, 32c Anode 34 Anode holder 36 First insoluble anode 38 Second insoluble anode 40, 40a, 40b Rectifier )
42a, 42b Variable resistors 44a, 44b, 44c, 46a, 46b, 46c, 50a, 50b Insoluble anode 52, 52a, 52b Anode 54a, 54b, 56a, 56b, 56c, 58a, 58b, 58c Insoluble anode 70 Substrate holder 72 Plating tank 74 Overflow tank 76 Circulating piping 84 Anode holder 86, 86a Anode 88 Shield plate 96 Anode band 98 First insoluble anode 100 Second insoluble anode 102 Rectifier (plating power source)
106a, 106b Insoluble anode 108 Side frame (substrate holder)

Claims (5)

The peripheral edge of the surface to be plated is brought into contact with the cathode contact and immersed in the plating solution to be opposed to the substrate placed vertically. An electroplating anode that applies electroplating to the surface of the substrate to be plated,
A first insoluble anode composed of a first insoluble material and a second insoluble anode composed of a second insoluble material having a higher oxygen generation overpotential than the first insoluble material , An anode for electroplating , wherein the periphery of the first insoluble anode is concentrically surrounded by the second insoluble anode and arranged in a plane. 2. The anode for electroplating according to claim 1, wherein the first insoluble anode is made of iridium oxide or ruthenium oxide, and the second insoluble anode is made of platinum . In the anode for electroplating disposed in the plating solution facing the surface to be plated of the substrate,
The first insoluble anode composed of iridium oxide or ruthenium oxide and the second insoluble anode composed of platinum are connected to each other, and the periphery of the first insoluble anode is surrounded by the second insoluble anode. An anode for electroplating, which is concentrically surrounded and arranged in a plane.   4. The anode for electroplating according to claim 1, wherein the anode for electroplating is formed in a shape similar to the shape of the surface to be plated of the substrate. A plating tank for holding a plating solution;
A substrate holder for holding the substrate and bringing the surface to be plated into contact with the plating solution in the plating tank;
The anode according to any one of claims 1 to 4 , which is disposed to face a surface to be plated of a substrate held by the substrate holder in a plating solution in the plating tank,
An electroplating apparatus comprising: a plating power source for applying a voltage between the substrate and the anode.

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