JP4833432B2 - Plating solution holding member for electroplating equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plating solution holding member for an electrolytic plating apparatus.
[0002]
[Prior art]
Attention has been attracted to electrolytic copper plating using an electrolytic plating apparatus as a technique for forming wiring on a semiconductor wafer, particularly as a technique for forming copper wiring on a semiconductor wafer in recent years.
[0003]
In a conventional general electroplating apparatus, a semiconductor wafer is immersed in a plating solution in a state where the plating solution is filled in the plating tank, and a film is formed by connecting a cathode to the semiconductor wafer and flowing electricity. It is like that.
[0004]
However, in order to form fine and uniform copper wiring using such a conventional apparatus, for example, it is necessary to flow a plating solution or to secure a certain distance between the cathode and the anode. For this reason, there was a tendency for the apparatus to become huge. Further, in the case of this conventional apparatus, a large amount of plating solution is required for one film formation, which is disadvantageous in achieving a reduction in the cost of the semiconductor.
[0005]
Therefore, recently, a next-generation electrolytic plating apparatus that can solve the above-mentioned problems has been proposed. This new electrolytic plating apparatus includes a plating solution supply unit, a cathode, an anode, a plating solution holding member, and the like. An anode is provided at the lower end of the plating supply unit. A slit for allowing the plating solution to pass therethrough is formed on the anode. A plating solution holding member made of porous alumina is provided on the lower surface side of the anode. On the other hand, the semiconductor wafer is supported in contact with the cathode. The upper surface of the semiconductor wafer and the lower surface of the plating solution holding member face each other with a slight gap therebetween.
[0006]
Therefore, the plating solution supplied to the plating solution supply unit passes through the slit of the anode and reaches the plating solution holding member, and then is supplied to the semiconductor wafer side through the pores of the plating solution holding member. By energizing the electrodes in this state, electrolytic plating is performed on the semiconductor wafer, and fine copper wiring is formed even in a static bath.
[0007]
[Problems to be solved by the invention]
However, in the case of the conventional apparatus, there is a case where the degree of deposition of copper plating varies between the outer peripheral portion and the central portion in one semiconductor wafer. For this reason, an apparatus capable of reliably obtaining a copper wiring having a uniform film thickness has been desired.
[0008]
This invention is made | formed in view of said subject, The objective is to provide the plating solution holding member for electrolytic plating apparatuses which can form the plating layer of a uniform film thickness reliably.
[0009]
[Means for Solving the Problems]
As a result of extensive research conducted by the inventors of the present invention in order to solve the above problems, the outer peripheral portion of the semiconductor wafer tends to have a higher plating rate than the central portion, and the plating layer formed on the outer peripheral portion. I found out that there is a tendency to become thicker. In addition, even if the plating solution holding member is made of a single substance, the inventor of the present application brings about a difference in the plating rate that the outer peripheral portion can flow more easily than the inner portion. It was also found that it was the cause. Therefore, the present inventor finally came up with the following invention based on these findings.
[0010]
That is, in the invention according to claim 1, Ri Do from relatively small porous ceramic plate as compared with the conductive inner portion also conductivity than that of the outer peripheral portion, the volume resistivity of the outer peripheral portion ¹⁰⁵ Ωm~10 ¹⁰ Ωm, and the gist of the electroplating apparatus, wherein the volume resistivity of the inner portion is 10 ¹ Ωm~10 ⁵ Ωm.
[0011]
According to a second aspect of the present invention, in the first aspect, the porous ceramic plate is a porous silicon carbide plate .
[0012]
The “action” of the present invention will be described below.
According to the first aspect of the invention, the difference in plating rate is eliminated by making the conductivity of the outer peripheral portion of the plating solution holding member relatively smaller than the conductivity of the inner portion. Therefore, the degree of plating deposition is easily uniformed between the outer peripheral portion and the central portion in one semiconductor wafer, and a copper wiring with a uniform film thickness can be obtained with certainty. Moreover, by setting the value of the volume resistivity of both portions within the above preferable range, it is possible to reliably form a plating layer having a uniform film thickness without increasing the cost.
If the volume resistivity of the outer peripheral portion is less than 10 ⁵ Ωm, the difference from the conductivity of the inner portion becomes insufficient, and the difference in plating rate cannot be reliably eliminated. On the other hand, if it exceeds 10 ¹⁰ Ωm, the conductivity becomes too small and it becomes difficult for electricity to flow, resulting in an excessively low plating rate. For this reason, the film thickness may vary. If it is intended to achieve a volume resistivity of the inner part of less than 10 ¹ Ωm, it may be difficult to select materials and set firing conditions, which may increase the manufacturing cost, and the porosity may be impaired. There is also. On the other hand, if it exceeds 10 ⁵ Ωm, the electrical conductivity becomes too low, and the plating solution holding member may not substantially function as an anode.
[0013]
According to the invention described in claim 2, since the plating solution holding member uses a porous silicon carbide plate having excellent corrosion resistance, the member is less likely to be corroded by the plating solution, and impurities are eluted into the plating solution. Is prevented. This avoids deterioration of the composition of the plating solution and stabilizes the deposition behavior of the plating. Moreover, since it is a plating solution holding member using porous silicon carbide superior in electrical conductivity as compared with porous alumina, the member substantially serves as an anode. Therefore, the member that is a pseudo anode becomes closer to the object to be plated, and a strong and stable electric field can be applied to the plating solution near the object to be plated.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an electrolytic copper plating apparatus 1 according to an embodiment of the present invention will be described in detail with reference to FIGS.
[0018]
The cathode 2 constituting the electrolytic copper plating apparatus 1 is an annular member whose diameter increases toward the upper end side, and a flange 3 is formed on the lower end side thereof. The cathode 2 is formed using, for example, a conductive metal material. The diameter of the lower end side opening 4 of the cathode 2 is set to be slightly smaller than the diameter of a semiconductor wafer (for example, a silicon wafer) 5 that is an object to be plated. The semiconductor wafer 5 is pressed against the flange 3 from below by a stage (not shown). As a result, the outer peripheral portion of the upper surface side of the semiconductor wafer 5 is in close contact with the lower surface side of the flange 3, and the semiconductor wafer 5 is held in this state. At this time, since the cathode 2 has a so-called bottomed shape, the electrolytic copper plating solution 15 is accumulated in a region formed on the upper surface side of the semiconductor wafer 5.
[0019]
On the other hand, the holder 12 which comprises this electrolytic copper plating apparatus 1 is arrange | positioned in the state which adjoined above the cathode 2 at the time of use. An opening 13 is provided on the lower end side of the holder 12, and a plate-like anode 14 is attached in the vicinity of the opening 13. The anode 14 is formed in a circular shape using, for example, a conductive metal material. Slits 16 are provided at a plurality of locations of the anode 14 as a structure for allowing the copper plating solution 15 to pass from the upper surface side to the lower surface side. On the upper surface of the holder 12, a plating solution supply pipe 17 and a plating solution recovery pipe 18 are provided. The plating solution supply pipe 17 communicates between a space 19 defined by the holder 12 and the anode 14 and a plating solution tank (not shown). When the copper plating solution 15 is insufficient, the copper plating solution 15 is replenished into the space 19 through the plating solution supply pipe 17. The plating solution recovery pipe 18 plays a role of recovering the surplus when the amount of the copper plating solution 15 in the space 19 exceeds a certain amount. The recovered copper plating solution 15 is returned to the plating solution tank and reused.
[0020]
A plating solution holding plate 21 as a plating solution holding member is provided in the opening 13 of the holder 12 so as to be in contact with the lower surface side of the anode 14. The plating solution holding plate 21 has substantially the same size and the same shape (that is, a disc shape) as the anode 14. The plating solution holding plate 21 includes a flange portion 21a that protrudes laterally from the outer peripheral portion. The flange portion 21 a is supported by a support portion 13 a provided in the opening 13 of the holder 12. A rubber annular packing 22 as a seal member is interposed between the lower surface of the flange portion 21a and the upper surface of the support portion 13a.
[0021]
The plating solution holding plate 21 also serves to prevent the copper plating solution 15 from flowing out from the lower surface side when the holder 12 is transferred by holding the copper plating solution 15 in its pores. Note that the lower surface of the plating solution holding plate 21 is opposed to the upper surface of the semiconductor wafer 5 with a slight gap therebetween. Specifically, in the present embodiment, the size of the gap is set to about 1 mm.
[0022]
Next, the material of the plating solution holding plate 21 used in this embodiment will be described in detail.
The plating solution holding plate 21 of the present embodiment is a porous ceramic plate, and specifically, a porous silicon carbide plate (porous SiC plate) P1 is used. The reason why porous silicon carbide is selected is that porous silicon carbide is superior in corrosion resistance and electrical conductivity as compared with porous alumina, and is extremely convenient as a material for the plating solution holding plate 21.
[0023]
The porosity of the plating solution holding plate 21 is preferably 20% to 50%, and more preferably 30% to 45%. The average pore diameter is preferably 10 μm to 60 μm, and more preferably 20 μm to 50 μm.
[0024]
If the porosity is less than 20%, the copper plating solution 15 becomes difficult to flow smoothly due to an increase in pressure loss, and the ease of the copper plating solution 15 leaching varies from place to place. That is, the amount of the copper plating solution 15 supplied from the lower surface side of the plating solution holding plate 21 becomes non-uniform, and as a result, the film thickness of the copper plating layer may become non-uniform. Conversely, if the porosity exceeds 50%, an increase in pressure loss can be avoided, but the property of holding the copper plating solution 15 is impaired. Therefore, even in this case, the thickness of the plating layer may be nonuniform.
[0025]
If the average pore diameter is less than 10 μm, the copper plating solution 15 becomes difficult to flow smoothly due to an increase in pressure loss, so that the ease with which the copper plating solution 15 exudes varies depending on the location. That is, the amount of the plating solution 15 supplied from the lower surface side of the plating solution holding plate 21 becomes non-uniform, and as a result, the film thickness of the copper plating layer may become non-uniform. Conversely, when the average pore diameter exceeds 60 μm, an increase in pressure loss can be avoided, but the property of holding the copper plating solution 15 is impaired. Therefore, even in this case, the film thickness of the copper plating layer may be non-uniform.
[0026]
In the porous silicon carbide plate P1 of the present embodiment, the conductivity of the outer peripheral portion needs to be relatively smaller than the conductivity of the inner portion. The reason is to eliminate the difference in plating rate between the outer peripheral portion and the inner portion by intentionally lowering the plating rate at the outer peripheral portion.
[0027]
For this reason, in the present embodiment, a layer made of a non-conductive substance is more specifically disposed on the outer peripheral portion of the porous silicon carbide plate P1 including the flange portion 21a. Are indicated by fine diagonal lines). As a result, the pores in the outer peripheral portion are filled.
[0028]
Examples of the thermosetting resin used for impregnation include fluorine resins such as Teflon, epoxy resins, and polyimide resins. In this case, it is preferable to use a thermosetting resin having a metal impurity concentration as low as possible.
[0029]
The volume resistivity of the outer peripheral portion is preferably 10 ⁵ Ωm to ^{10 10} Ωm, and more preferably 10 ⁶ Ωm to 10 ⁹ Ωm. If the volume resistivity of the outer peripheral portion is less than 10 ⁵ Ωm, the difference from the conductivity of the inner portion becomes insufficient, and the difference in plating rate cannot be reliably eliminated. On the other hand, if it exceeds 10 ¹⁰ Ωm, the conductivity becomes too small and it becomes difficult for electricity to flow, resulting in an excessively low plating rate. For this reason, the film thickness may vary.
[0030]
The volume resistivity of the inner part is preferably 10 ¹ Ωm to 10 ⁵ Ωm, more preferably 10 ² Ωm to 10 ⁴ Ωm. If it is intended to realize a material having a volume resistivity of less than 10 ¹ Ωm, it becomes difficult to select materials and set firing conditions, and the manufacturing cost of the plating solution holding plate 21 may increase. In addition, the porosity of the plating solution holding plate 21 may be impaired, and the basic performance of plating solution holding property may be impaired. On the other hand, if it exceeds 10 ⁵ Ωm, the electrical conductivity becomes too low, and the plating solution holding plate 21 may not substantially function as the anode 14. Therefore, there is a possibility that a strong and stable electric field cannot be applied to the copper plating solution 15 near the upper surface of the semiconductor wafer 5.
[0031]
The density of the plating solution holding plate 21 is 1.6 g / cm ^{3 to} 2.5 g / cm ³ , the bending strength is 30 MPa to 150 MPa, the Young's modulus is 50 GPa to 200 GPa, and the thermal conductivity is 50 W / m · K to 150 W / It may be m · K. Further, as the porous silicon carbide constituting the plating solution holding plate 21, high purity porous silicon carbide is preferably used. Specifically, porous silicon carbide having a concentration of heavy metal as an impurity of 0.5% or less is preferably used.
[0032]
Here, a method for manufacturing the plating solution holding plate 21 of the present embodiment will be described. First, one or more silicon carbide powders as raw materials are prepared. And after mix | blending a solvent, a binder, etc. with silicon carbide powder, this is mixed well. The mixture is then dried and then the dried mixture is granulated. And it shape | molds using the granule obtained by the said granulation process as a material, and produces a disk-shaped molded object. In this case, it is preferable to set the conditions so that the density distribution at the time of molding falls within the range of ± 0.05 g / cm ³ . In the present embodiment, a hydrostatic press is adopted as a pressing method for realizing this. Next, the molded body obtained by the molding process is fired at normal pressure at a temperature of about 2000 ° C. to 2300 ° C. in an inert atmosphere to sinter the molded body (ie, porous silicon carbide). A plate P1) is obtained. In this case, it is preferable to set conditions so that the in-plane temperature distribution of the molded body during firing is within ± 1 ° C. Next, the resin-impregnated layer 23 is formed by impregnating the outer peripheral portion of the porous silicon carbide plate P1 with the resin and then heat-curing the resin.
[0033]
Next, a method of using the electrolytic copper plating apparatus 1 using the plating solution holding plate 21 configured as described above will be described.
In the case of the electrolytic copper plating apparatus 1, a certain amount of the copper plating solution 15 supplied through the plating solution supply pipe 17 is accumulated in the space 19. The copper plating solution 15 supplied to the space 19 passes through the slit 16 of the anode 14 and reaches the plating solution holding plate 21. The copper plating solution 15 is further supplied to the upper surface side of the semiconductor wafer 5 through the pores of the plating solution holding plate 21. Therefore, by conducting current between the anode 14 and the cathode 2 in this state, electrolytic copper plating is performed while still bathing. Then, a copper plating layer is deposited so as to fill a wiring groove dug in advance on the upper surface side of the semiconductor wafer 5, and as a result, a copper wiring having a desired pattern shape is formed.
[0034]
【Example】
[Example 1]
In the production of Example 1, GC # 240 (manufactured by Shinano Denki Co., Ltd., average particle size 57 μm) and GMF-15H2 (manufactured by Taiheiyo Random Co., Ltd., average particle size 0.5 μm) were used as the raw material silicon carbide powder in a weight ratio. Was 7: 3. Then, these two types of silicon carbide powders were further mixed with water and an acrylic resin as a binder, which were mixed well using a pot mill. The uniform mixture obtained by the mixing step was dried for a predetermined time to remove water to some extent, and then an appropriate amount of the dried mixture was collected and granulated with a spray dryer.
[0035]
And the granule obtained by the said granulation process was used as a material, and the hydrostatic pressure press was performed by the pressure of about 100 MPa-130 MPa, and the disk-shaped molded object was produced. Next, the molded body obtained by the molding step was fired at normal pressure at a temperature of 2100 ° C. to 2200 ° C. in an argon atmosphere. The resin-impregnated layer 23 was formed by impregnating the resin into the outer peripheral portion of the porous silicon carbide plate P1 obtained by firing and then curing the resin by heating. Here, a fluororesin (manufactured by DuPont, trade name Teflon) was used as the thermosetting resin, and the heating temperature was set to 400 ° C. and the heating time was set to 5 minutes. As a result, a disk-shaped plating solution holding plate 21 made of porous silicon carbide was obtained.
[0036]
The unimpregnated region in the plating solution holding plate 21 of Example 1 has a porosity of about 25%, an average pore diameter of about 15 μm, a volume resistivity of 10 ³ Ωm, a density of 2.4 g / cm ³ , and a bending strength of It was 130 MPa, the thermal conductivity was 140 W / m · K, and the heavy metal concentration was 0.5% or less. On the other hand, the impregnation region was dense with a porosity of about 0% and an average pore diameter of 0 μm. The volume resistivity was 10 ¹⁰ Ωm.
[0037]
In such a plating solution holding plate 21, when the plating rate was measured at a plurality of positions by a conventionally known method, the plating rate curve became flat as shown in the graph of FIG. That is, the formation of the resin-impregnated layer 23 reduces the conductivity of the outer peripheral portion of the plating solution holding plate 21 and eliminates the difference in plating rate. Moreover, when electrolytic copper plating was performed, it was possible to form a copper wiring with a uniform film thickness on one semiconductor wafer 5 without the plating solution supply amount varying depending on the location.
[Example 2]
In the production of Example 2, GC # 240 (manufactured by Shinano Denki Co., Ltd., average particle size 57 μm) and GMF-15H2 (manufactured by Taiheiyo Random Co., Ltd., average particle size 0.5 μm) are used as raw material silicon carbide powder in a weight ratio. Was 9: 1. And these two types of silicon carbide powders were further mixed with water and an acrylic resin as a binder, and granulated at the same time while thoroughly mixing them using a universal mixer.
[0038]
And the granule obtained by the said mixing and granulation process was used as a material, and the hydrostatic pressure press was performed by the pressure of about 50 MPa, and the disk-shaped molded object was produced. Next, the molded body obtained by the molding step was fired at normal pressure at a temperature of 2250 ° C. in an argon atmosphere. The resin-impregnated layer 23 was formed by impregnating the resin into the outer peripheral portion of the porous silicon carbide plate P1 obtained by firing and then curing the resin by heating. Here, an epoxy resin (trade name EP-160, manufactured by Cemedine Co., Ltd.) was used as the thermosetting resin, and the heating temperature was set to 150 ° C. and the heating time was set to 60 minutes. As a result, a disk-shaped plating solution holding plate 21 made of porous silicon carbide was obtained.
[0039]
The unimpregnated region in the plating solution holding plate 21 of Example 2 has a porosity of about 40%, an average pore diameter of about 30 μm, a volume resistivity of 10 ³ Ωm, a density of 1.9 g / cm ³ , and a bending strength of The pressure was 50 MPa, the thermal conductivity was 80 W / m · K, and the heavy metal concentration was 0.5% or less. On the other hand, the impregnation region was dense with a porosity of about 0% and an average pore diameter of 0 μm. The volume resistivity was 10 ¹⁰ Ωm.
[0040]
Also in such a plating solution holding plate 21, the plating rate curve was flat as shown in the graph of FIG. 3, and the difference in plating rate depending on the position was eliminated. Moreover, when electrolytic copper plating was performed, it was possible to form a copper wiring with a uniform film thickness on one semiconductor wafer 5 without the plating solution supply amount varying depending on the location.
[Comparative example]
Except that the resin-impregnated layer 23 is not formed, a disk-shaped plating solution holding plate 21 made of porous silicon carbide was basically produced according to the same procedure as in Example 1.
[0041]
When the plating rate was measured in the plating solution holding plate 21 of such a comparative example, the graph shown in FIG. That is, the plating rate at the outer peripheral portion was clearly larger than the plating rate at the inner portion. Therefore, when electrolytic copper plating was performed, the amount of plating solution supplied varied depending on the location, and it was difficult to form a copper wiring with a uniform film thickness on one semiconductor wafer 5.
[0042]
Therefore, according to the present embodiment, the following effects can be obtained.
(1) In this embodiment, the conductivity of the outer peripheral portion of the plating solution holding plate 21 is relatively smaller than the conductivity of the inner portion. For this reason, the difference of the plating rate by a position is eliminated, and a plating rate curve becomes flat. Accordingly, the degree of deposition of plating is easily uniformed between the outer peripheral portion and the central portion in one semiconductor wafer 5, and a copper plating layer (that is, copper wiring) having a uniform film thickness can be obtained with certainty.
[0043]
(2) In the plating solution holding plate 21 of this embodiment, the porous silicon carbide plate P1 excellent in corrosion resistance is used. For this reason, the member is less likely to be corroded by the copper plating solution 15, and the elution of impurities into the copper plating solution 15 is prevented. Thereby, composition deterioration of the copper plating solution 15 is avoided, and the deposition behavior of the copper plating is stabilized.
[0044]
In addition, since the plating solution holding plate 21 is made of porous silicon carbide that is superior in electrical conductivity compared to porous alumina, the member substantially serves as the anode 14. Therefore, the member as the pseudo anode 14 is brought closer to the semiconductor wafer 5, and a strong and stable electric field can be applied to the copper plating solution 15 in the vicinity of the semiconductor wafer 5.
[0045]
(3) In this embodiment, the values of the volume resistivity of the outer peripheral portion and the inner portion are set within the above preferred range. For this reason, it is possible to reliably form a copper plating layer having a uniform film thickness without increasing the cost.
[0046]
(4) In this plating solution holding plate 21, a resin (thermosetting resin) that is a relatively simple and relatively inexpensive material is selected as a material for forming a layer made of a non-conductive substance. Yes. Therefore, manufacturing difficulty and cost increase can be avoided. Further, a layer made of a thermosetting resin is resistant to heat, and has an advantage that even if plating is performed under heating, peeling or the like hardly occurs. Therefore, the plating solution holding plate 21 is excellent in heat resistance and reliability.
[0047]
(5) In this plating solution holding plate 21, the resin-impregnated layer 23 is formed by impregnating pores in the outer peripheral portion with a thermosetting resin. Therefore, the pores can be filled easily and surely. Moreover, as a result of the pores providing a suitable anchor effect, the resin-impregnated layer 23 is hardly peeled off from the outer peripheral portion. Therefore, the plating solution holding plate 21 is excellent in durability and reliability.
[0048]
In addition, you may change embodiment of this invention as follows.
-Instead of layer formation by resin impregnation as in the embodiment, for example, layer formation by simple coating of resin (that is, layer formation by a method having a low degree of entering the inside of pores) may be performed. Moreover, the resin used for layer formation does not necessarily have thermosetting properties, and may be, for example, photocurable properties.
[0049]
The layer made of a non-conductive substance is not limited to only an organic material such as a resin. For example, the layer may be formed by CVD using a non-conductive ceramic.
-Since the flange part 21a is not essential, you may abbreviate | omit.
[0050]
The electrolytic plating apparatus 1 of the embodiment can be used not only when performing electrolytic copper plating but also when performing electrolytic nickel plating or electrolytic gold plating, for example.
[0051]
The object to be plated is not limited to the semiconductor wafer 5 made of silicon, gallium arsenide, or the like, and may be, for example, a ceramic, metal, or plastic substrate.
[0052]
The electroplating apparatus 1 of the embodiment can be used not only for the formation of wiring, but also for the formation of external connection terminals in semiconductors such as bumps, for example. Furthermore, the electroplating apparatus 1 is not only used for forming a metal layer for the purpose of flowing electricity as in the case of the wiring, but is used for forming a metal layer that is not specifically intended for flowing electricity. It does not matter.
[0053]
The upper surface of the plating solution holding plate 21 may be disposed in a non-contact state with respect to the lower surface of the anode 14.
Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the embodiment described above are listed below.
[0054]
(1) In Claim 1 or 2 , the porosity of the plating solution holding member is 20% to 50%, and the average pore diameter is 10 μm to 60 μm. Therefore, according to the invention described in the technical idea 1, the plating solution can be uniformly exuded from one side of the member, and as a result, a plating layer having a uniform film thickness can be reliably formed.
[0055]
(2) In any one of claims 1 and 2 and technical idea 1, pores in the outer peripheral portion are impregnated with a thermosetting resin.
[0056]
【The invention's effect】
As described above in detail, according to the invention described in claim 1 or 2 , it is possible to provide a plating solution holding member for an electrolytic plating apparatus capable of reliably forming a plating layer having a uniform film thickness.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an electrolytic copper plating apparatus according to an embodiment of the present invention.
FIG. 2 is a graph showing a difference in plating rate depending on position in a comparative example.
FIG. 3 is a graph showing the difference in plating rate depending on the position in Examples 1 and 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electrolytic copper plating apparatus as an electroplating apparatus, 2 ... Cathode, 5 ... Semiconductor wafer as to-be-plated object, 13 ... Opening part, 14 ... Anode, 15 ... Plating solution, 21 ... Plating solution as a plating solution holding member Holding plate, P1... A porous silicon carbide plate as a porous ceramic plate.

Claims (2)

Ri conductive outer peripheral portion Do from relatively small porous ceramic plate as compared with the conductive inner portion than the volume resistivity of the outer peripheral portion ^{10 5} Ωm~10 10 Ωm, the volume of the inner part plating liquid holding member for electrolytic plating apparatus characterized by resistivity is 10 ¹ Ωm~10 ⁵ Ωm. The plating solution holding member for an electroplating apparatus according to claim 1, wherein the porous ceramic plate is a porous silicon carbide plate .

Images