Substrate plating device

Information

  • Patent Grant
  • 6365017
  • Patent Number
    6,365,017
  • Date Filed
    Friday, May 5, 2000
    24 years ago
  • Date Issued
    Tuesday, April 2, 2002
    22 years ago
Abstract
The present invention relates to a substrate plating apparatus for plating a substrate in a plating bath containing plating solution. An insoluble anode is disposed in the plating bath opposite the substrate. The substrate plating apparatus comprises a circulating vessel or dummy vessel provided separate from the plating bath, with a soluble anode and a cathode disposed in the circulating vessel or dummy vessel. An anion exchange film or selective cation exchange film is disposed between the anode and cathode and isolates the same, wherein metal ions are generated in the circulating vessel or dummy vessel by flowing current between the soluble anode and the cathode therein, and the generated metal ions are supplied to the plating bath. The substrate plating apparatus can also comprise an ion exchange film or neutral porous diaphragm disposed between the substrate and anode in the plating bath, wherein the ion exchange film or neutral porous diaphragm divides the plating bath into a substrate region and an anode region.
Description




TECHNICAL FIELD




The present invention relates to a substrate plating apparatus for performing a metal plating process on a substrate such as a semiconductor wafer.




BACKGROUND ART





FIG. 1

shows the general structure for this type of a conventional substrate plating apparatus. As shown in

FIG. 1

, a substrate plating vessel


101


accommodates a plating solution Q. Disposed within the substrate plating vessel


101


are a substrate


102


, such as a semiconductor wafer; an anode


103


positioned opposite the substrate


102


; and a shielding plate


104


interposed between the substrate


102


and anode


103


. A power source


106


applies a predetermined voltage between the substrate


102


and anode


103


for forming a plating film on the surface of the substrate


102


. A collecting gutter


105


is provided for collecting plating solution Q that overflows from the top end of the substrate plating vessel


101


.




When suing a soluble electrode (have phosphorous copper) for the anode


103


in the substrate plating apparatus described above, it is necessary not only to regularly replace the anode but also to process black film on the surface of the electrode and take measures for generated particles. Since this type of substrate plating apparatus is normally provided with a plurality of substrate plating vessels


101


, upkeep of the anode


103


can be considerably time-consuming.




One method of attempting to correct these problems is to use an anode formed of an insoluble material in the plate processing vessel. While this material has the advantage of suppressing the existence of particles around the substrate


102


, it gives rise to the necessity for replenishing Cu


2+


ions. Cu


2+


ions can be added by supplying copper oxide powder or CuSO


4


—5H


2


O powder, or by supplying a highly concentrated solution of CuSO


4


—5H


2


O. However, supplying powder is not appropriate for an automated process. Further, adding a solution gradually increases the overall amount of liquid, thus requiring that the plating solution be periodically discharged.




To improve the uniformity of the plating film thickness formed on the surface of the substrate


102


in the plating vessel described above, it is best to ensure that the primary current distribution between the cathode (substrate


102


) and the anode


103


is uniform. One way to ensure a uniform distribution of the current is to increase the distance between the cathode and the anode


103


. However, this requires a larger substrate plating vessel


101


, and consequently, a larger plating apparatus, which is contrary to the object of decreasing the size of the plating apparatus.




When the electrolytic plating conducted is copper plating, for example, the soluble anode often includes phosphorus copper. However, it is difficult to manage the black film formed on the surface of this soluble anode, and the black film produces particle contaminants that can be a large problem. This problem can be overcome by using an insoluble anode. However, insoluble anodes give rise to the problem of how to supply Cu ions to the plating solution, as well as the problem of the additive dissolving and becoming deposited on the semiconductor wafer or other substrate.




DISCLOSURE OF INVENTION




In view of the foregoing, it is an object of the present invention to provide a substrate plating apparatus employing an insoluble anode, and particularly a substrate plating apparatus capable of easily and automatically supplying metal ions.




It is another object of the present invention to provide a substrate plating apparatus capable of supplying a uniform primary current distribution between the cathode and anode and facilitating reduction of the size of the plating apparatus.




It is further another object of the present invention to provide a plating apparatus capable of preventing the substrate from being contaminated by particles produced from black film, even when using a soluble anode.




These objects and others will be attained with a substrate plating apparatus for plating a substrate in accordance with the present invention. The substrate plating apparatus comprises a plating bath containing plating solution. A substrate is disposed in the plating bath and serves as a cathode. A insoluble anode is disposed in the plating bath opposite the substrate. A circulating vessel or dummy vessel is provided separate from the plating bath. A soluble anode is disposed in the circulating vessel or dummy vessel. A cathode is disposed in the circulating vessel or dummy vessel opposite the soluble anode. An anion exchange film or selective cation exchange film is disposed between the anode and cathode and isolates the same. And also provided is an ion replenishing system for creating a current between the anode and cathode to generate and supply metallic ions to the plating bath.




The substrate plating apparatus described above is constructed with a circulating vessel or dummy vessel separate from the plating bath, such that metal ions generated from the soluble anode in the circulating vessel or dummy vessel are supplied to the plating bath. With this construction, it is possible to supply metal ions automatically. Further, this construction eliminates the need to perform cumbersome jobs associated with conventional devices, such as regularly replacing the anode in the plating bath and taking measures to treat black film generated on the surface of the anode.




According to another aspect of the present invention, a substrate plating apparatus for plating a substrate comprises a plating bath containing plating solution. A substrate is disposed in the plating bath. An anode is disposed in the plating bath opposite the substrate. And, an ion exchange film or neutral porous diaphragm is disposed between the substrate and anode in the plating bath, wherein the ion exchange film or neutral porous diaphragm divides the plating bath into a substrate region and an anode region.




The ion exchange film or neutral porous diaphragm provided between the substrate and anode serves to increase the electrical resistance of the plating solution, achieving the same effects as increasing the distance between the substrate and the anode. Accordingly, it is possible to dispose the substrate and anode close together.




Further, the cation exchange film allows the passage of ions dissolved from the anode and blocks impurities dissolved from the anode. Accordingly, the amount of particles in the plating solution in the substrate region can be greatly reduced.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

shows the general construction of a conventional substrate plating apparatus;





FIG. 2

shows a first embodiment of a substrate plating apparatus according to the present invention;





FIG. 3

shows another embodiment of a circulating vessel or dummy vessel used in the substrate plating apparatus;





FIG. 4

shows another embodiment of the substrate plating apparatus according to the present invention;





FIG. 5

shows a second embodiment of the substrate plating apparatus according to the present invention;





FIG. 6

is an explanatory diagram showing the effects of disposing a positive ion exchange film or neutral porous diaphragm between the cathode and anode in the substrate plating apparatus;





FIG. 7

is a cross-sectional view showing a detailed structure of a substrate plating apparatus according to the second embodiment of the present invention;





FIG. 8

is a cross-section view showing another embodiment of the detailed structure of the substrate plating apparatus;





FIG. 9

shows a third embodiment of a substrate plating apparatus according to the present invention;





FIG. 10

is an enlarged view of the area B in

FIG. 9

;





FIG. 11

shows another embodiment of a substrate plating apparatus; and





FIGS. 12A and 12B

are a plan view and a side view respectively showing the overall structure of the substrate plating apparatus employing the plating bath.











BEST MODE FOR CARRYING OUT THE INVENTION




A substrate plating apparatus according to preferred embodiments of the present invention will be described while referring to the accompanying drawings.





FIG. 2

shows an embodiment of a substrate plating apparatus according to a first embodiment of the present invention. The substrate plating apparatus includes a circulating vessel or dummy vessel


10


and a plurality (three in this embodiment) of plating baths


11


. Each plating bath


11


contains a semiconductor wafer


12


that is the object of a copper plating process; an insoluble anode


13


disposed opposite the semiconductor wafer


12


; and a power source


15


connected between the semiconductor wafer


12


and the anode


13


.




The circulating vessel or dummy vessel


10


contains a dummy cathode


16


; a soluble anode


17


formed of copper and disposed opposite the cathode


16


; and an anion exchange film


18


disposed between the cathode


16


and anode


17


for dividing the circulating vessel or dummy vessel


10


into a dummy cathode side and an anode side. A DC power source


19


is connected between the cathode


16


and anode


17


. A conductivity analyzer


21


is provided on the circulating vessel or dummy vessel


10


to measure the conductivity of the liquid contained within the circulating vessel or dummy vessel


10


. Sulfuric acid (H


2


SO


4


) is supplied from a sulfuric acid source


20


to maintain the liquid at a uniform conductivity.




By applying a DC voltage of a predetermined amount from the power source


19


, the anode


17


emits Cu


2+


ions into the liquid on the anode side, while on the cathode side SO


4




2−


negative ions and H


2


gas are generated. The H


2


gas escapes from the top of the vessel. The SO


4




2−


ions pass through the anion exchange film


18


and are supplied to the anode side, while the Cu


2+


ions do not pass through the anion exchange film


18


. A pump


22


pumps out the aqueous solution containing a mixture of Cu


2+


and SO


4




2−


ions. This solution is supplied as the plating solution to each of the plating baths


11


via a plurality of on-off valves


23


.




A collecting gutter


14


is provided on each of the plating baths


11


to collect excess plating solution that overflows from the plating baths


11


. This excess liquid collected by the collecting gutter


14


is returned to the anode side of the circulating vessel or dummy vessel


10


. At this time, the anode


17


replenishes the liquid with Cu


2+


ions and the liquid is subsequently resupplied to each of the plating baths


11


. In other words, the plating solution is supplied with Cu


2+


ions to compensate for the amount consumed in the copper plating process conducted in each of the plating baths


11


.




In the plating apparatus described above, the sum of currents I


1


, I


2


, and I


3


flowing between the semiconductor wafer


12


and anode


13


of each respective plating bath


11


is set equal to a current I flowing between the cathode


16


and anode


17


in the circulating vessel or dummy vessel


10


(I=I


1


+I


2


+I


3


). As a result, it is possible to supply to each of the plating baths


11


an amount of Cu


2+


ions corresponding to the amount consumed in the plating process. In addition, there is no longer a need to replace the anodes in the plating baths


11


regularly or to perform bothersome measures or operations associated with the prior art to prevent contamination generated by black film on the surface of the anodes. Also in

FIG. 2

, a pump


24


is provided for discharging liquid from the circulating vessel or dummy vessel


10


.





FIG. 3

shows another embodiment of a construction of the circulating vessel or dummy vessel


10


employed in the substrate plating apparatus of the present invention. The embodiment in

FIG. 3

differs from that in

FIG. 2

only in that the anion exchange film


18


provided between the cathode


16


and anode


17


is replaced with a selective cation exchange film


25


. The cation exchange film


25


allows the passage of H


+


ions, but prevents the passage of Cu


2+


ions.




With this configuration, the power source


19


applies a direct current of a predetermined value between the cathode


16


and anode


17


and the pump


22


supplies a plating solution containing Cu


2+


ions emitted from the anode


17


to each of the plating baths


11


shown in

FIG. 2

via the plurality of on-off valves


23


. Plating liquid overflowing from each of the plating baths


11


is returned to the anode side of the circulating vessel or dummy vessel


10


, as described for FIG.


2


.





FIG. 4

shows another embodiment of a substrate plating apparatus according to the present invention. In this substrate plating apparatus, one circulating vessel or dummy vessel


10


is provided for each plating bath


11


. Liquid in the anode side of the circulating vessel or dummy vessel


10


as divided by the anion exchange film


18


or cation exchange film


25


is supplied to the plating baths


11


, while plating solution overflowing from the plating baths


11


is returned to the anode side of the circulating vessel or dummy vessel


10


.




The semiconductor wafer


12


, serving as the cathode in the plating baths


11


, is connected to the anode


17


in the circulating vessel or dummy vessel


10


, while the anode


13


is connected to the cathode


16


. Connecting wires


27


and


28


are provided to connect the semiconductor wafer


12


and anode


17


and the insoluble anode


13


and cathode


16


, respectively. A power source


26


is connected in the middle of either the connecting wire


27


or the connecting wire


28


.




With a substrate plating apparatus as described above, the current flowing between the cathode


16


and anode


17


is the same as the current I flowing between the semiconductor wafer


12


and anode


13


. Accordingly, an amount of Cu


2+


ions equivalent to the amount consumed in the plating baths


11


is supplied from the circulating vessel or dummy vessel


10


.




In the substrate plating apparatus shown in

FIGS. 2-4

, the liquid contact area of the selective ion exchange film disposed between the cathode


16


and anode


17


must of course be adjusted based on the type of ions used. As described on page 5 of the


Plating Manual


(Mekki Kyohon) by the Electroplating Society (Nikkan Kogyo Shinbun, Ltd.), the speed of ions in liquid differs as shown below, depending on whether the ions are H


+


, Cu


2+


, or SO


4




2−


.




Moving Speed of Ions in Aqueous Solution at 18° C.






















Cation selective exchange film




H


+






31.5 μm/s








Cu


2+






 2.9 μm/s







Anion selective exchange film




SO


4




2−






5.93 μm/s















The moving speeds indicated above were measured by applying a voltage of 1 V between electrodes spaced 1 centimeter apart.




In the embodiment described above, the soluble anode


17


is formed of copper and generates Cu


2+


ions, and a copper plating process is conducted on the semiconductor wafer


12


. However, the present invention is not limited to conducting copper plating in the plating baths


11


, but can be applied to other types of metal plating. When performing a different type of metal plating, the soluble anode


17


should be a metal anode that emits positive metallic ions corresponding to the type of metal plating to be performed.




Further, the substrate in the present embodiment is not limited to a semiconductor wafer, but can apply to any substrate capable of being plated.




A substrate plating apparatus according to the first embodiment of the present invention has the following remarkable advantages.




By replenishing the plating bath with metallic ions generated from the soluble anode in the circulating vessel or dummy vessel provided separately from the plating supply vessel, not only is it possible to automatically supply metallic ions, but it is no longer necessary to replace the anode in the plating supply vessel regularly or take measures against black film on the surface of the anode.




By making the current flowing between the anode and cathode in the circulating vessel or dummy vessel equal to the total current flowing between substrates and insoluble anodes in the plating baths, maintenance need only be conducted on the soluble anode in one circulating vessel or dummy vessel.




Further, by making the current flowing between the anode and cathode of the circulating vessel or dummy vessel equal to the current flowing between the anode and cathode of the plating bath, it is possible to supply an amount of metallic ions equal to the amount consumed in the plating bath.





FIG. 5

shows a partial view of a substrate plating apparatus according to a second embodiment of the present invention. As shown in the diagram, the substrate plating apparatus includes a positive ion exchange film


108


disposed between the substrate


102


(cathode) and anode


103


.




As described above, a uniform distribution of the primary current should be provided between the substrate


102


and anode


103


to improve uniformity of the plating thickness on the surface of the substrate


102


. In order to attain a uniform primary current distribution, the distance between the substrate


102


and the anode


103


should be large. However, in order to increase the distance between the substrate


102


and anode


103


, the substrate plating vessel


101


must also be large. Here, disposing the positive ion exchange film


108


between the substrate


102


and anode


103


is equivalent to increasing the distance between the substrate


102


and anode


103


. The positive ion exchange film


108


divides the substrate plating vessel


101


into two regions, that is, the region near the substrate


102


and the region near the anode


103


.




With regard to the distance between the substrate


102


and anode


103


in the apparatus shown in

FIG. 5

at L


2


and the distance between the substrate


102


and anode


103


in the apparatus of the prior art, which is not provided with a positive ion exchange film


108


, at L


1


, the following relationship is true even when attaining a uniform distribution of the same primary current.








L




1




>>L




2








In other words, the interval L


2


between the substrate


102


and anode


103


in the present invention can be made smaller than the interval L


1


in the prior art to obtain a uniform primary current distribution.





FIG. 6

shows the effects of disposing a positive ion exchange film


108


between the substrate


102


and anode


103


. As shown in the diagram, a step is incorporated in the surface of the anode


103


. Assuming that the current density at the interval L


1


between the substrate


102


and anode


103


is I


1


, the current density at the interval L


2


is I


2


, the resistance of the plating solution Q is ρ, and the transmission resistance is R, then:











i
2

/

i
1


=


(



1
1


ρ

+
R

)

/

(



1
2


ρ

+
R

)













=



{


1
2

+

Δ





1


)


ρ

+
R


}

/

1
2



ρ

+
R

)






=

1
+


(

Δ





1

ρ

)

/

(



1
2


ρ

+
R

)
















Hence, to achieve a uniform primary current distribution, the current density i


2


/i


1


should approach






1


. Rather than increasing the distance l


2


between the substrate


102


and anode


103


for this fraction to approach 1, the positive ion exchange film


108


is disposed between the substrate


102


and anode


103


to provide electrical resistance in the plating solution. This achieves the same effects. In other words, positioning the ion exchange film


108


between the substrate


102


and anode


103


has the same effects as increasing the distance between the substrate


102


and anode


103


, even when the distance is not great. This in turn enables the construction of a small substrate plating apparatus.




When the substrate plating apparatus shown in

FIG. 5

is a copper plating apparatus for forming a copper plating film on the substrate


102


, the anode


103


is a soluble anode, and the plating solution is copper sulfate, if the cation exchange film


108


only allows the passage of Cu


2+


ions dissolved from the anode


103


, then the ion exchange film


108


can block impurities dissolved from the anode


103


, drastically reducing the number of particles in the liquid near the region of the substrate


102


.




While the invention described above employs an ion exchange film


108


between the substrate


102


and anode


103


, a neutral porous diaphragm employing a fine particle removing function can be used in place of the ion exchange film


108


with the same effects.




The ion exchange film described above can be a commercial product having the capability of selectively filtering ions according to their electrical property. One such example is “Ceremion” produced by the Asahi Glass Company. The neutral porous diaphragm is a porous film formed of synthetic resin and having extremely small holes of uniform diameter. One such example is a product called “YUMICRON” manufactured by Yuasa Ionics, which has an aggregate of polyester and a film material formed of polyvinylidene fluoride and titanium oxide.





FIG. 7

is a cross-sectional view showing the basic construction of a plating bath used in the substrate plating apparatus of the present invention. As shown in the diagram, a plating bath


41


includes a main section


45


and a side plate


46


. A depression


44


is formed in the main section


45


for accommodating plating solution. A hinge mechanism (not shown) is provided on the lower end of the side plate


46


to enable the opening and closing of the opening to the depression


44


. A soluble anode


47


is disposed on the surface of a bottom plate


45




a


of the main section


45


on the side plate


46


side. A substrate


48


, such as a semiconductor wafer, for plating is mounted on the main section


45


side surface of the side plate


46


. A packing


50


contacts the surface of the substrate


48


when the side plate


46


is closed over the opening of the depression


44


. The depression


44


is hermetically sealed.




An ion exchange film or neutral porous diaphragm


49


is disposed between the substrate


48


and anode


47


when the side plate


46


is closed over the depression


44


, thereby dividing the depression


44


into a substrate region


44


-


1


and an anode region


44


-


2


. An upper header


42


and a lower header


43


are provided on the top and bottom of the main section


45


, respectively. An opening


42




a


in the upper header


42


and an opening


43




a


in the lower header


43


are in liquid communication with the substrate region


44


-


1


.




A plating solution inlet


51


and outlet


52


are formed in liquid communication with the top and bottom of the anode region


44


-


2


, respectively. Shutoff valves


55


and


56


are disposed at the ends of the inlet


51


and outlet


52


via filters


53


and


54


. The shutoff valves


55


and


56


are connected to the openings


42




a


and


43




a


via pipes


57


and


58


respectively. Hence, plating solution entering the substrate region


44


-


1


and anode region


44


-


2


in the main section


45


is separated externally from the main section


45


before being introduced therein. After exiting the main section


45


, the plating solution is recombined outside the main section


45


. Further, plating solution entering and exiting the anode region


44


-


2


must pass through the filters


53


and


54


. The apparatus shown in

FIG. 7

also includes reverse stop valves


59


and


60


.




In the plating bath


41


described above, a plating solution Q in the pipe


58


is supplied via the opening


43




a


to the substrate region


44


-


1


and via the shutoff valve


56


and filter


54


to the anode region


44


-


2


. Accordingly, the plating solution Q flows in the direction indicated by the arrows A through the substrate region


44


-


1


and anode region


44


-


2


. The plating solution Q in the substrate region


44


-


1


passes through the opening


42




a


and flows out into the pipe


57


. The plating solution Q in the anode region


44


-


2


flows through the inlet


51


, the filter


53


, and the shutoff valve


55


and merges with the plating solution Q from the substrate region


44


-


1


flowing in the pipe


57


.




In the substrate plating apparatus described above, black film deposited on the surface of the anode


47


produces particles in the plating solution Q in the anode region


44


-


2


. However, these particles are prevented from being combined with the plating solution Q in the substrate region


44


-


1


because the plating solution Q flowing out of the anode region


44


-


2


passes through the filter


53


and shutoff valve


55


before combining outside of the main section


45


with plating solution Q flowing out of the substrate region


44


-


1


.




Before removing the substrate


48


from the plating bath


41


, the plating solution Q is discharged from the substrate region


44


-


1


. The plating solution Q in the anode region


44


-


2


should not be discharged in order to prevent the black film on the surface of the anode


47


from converting into white film. Therefore, when removing the substrate


48


from the plating bath


41


, the shutoff valve


55


and shutoff valve


56


can be closed to prevent the discharge of plating solution Q from the anode region


44


-


2


.




In the embodiment described above, plating solution Q flows in the substrate region


44


-


1


and anode region


44


-


2


from the bottom of the main section


45


to the top. However, it is also possible to configure the main section


45


such that the plating solution Q flows from the top to the bottom or alternates directions from the top to the bottom and the bottom to the top. Furthermore, a predetermined voltage is applied between the substrate


48


and anode


47


.




As described above, the ion exchange film or neutral porous diaphragm


49


is disposed between the substrate


48


and anode


47


to achieve the equivalent effect of increasing electrical resistance in the plating solution Q between the substrate


48


and anode


47


. Hence, even if the distance between the substrate


48


and anode


47


is small it is still possible to achieve a uniform primary current distribution between the substrate


48


and anode


47


, thereby forming a plating film of uniform thickness on the surface of the substrate


48


.




If the anode


47


is a soluble electrode, such as a copper plate, and the plating solution Q is copper sulfate solution, then the cation exchange film or neutral porous diaphragm


49


allows only the passage of copper ions dissolved from the anode


47


. As a result, the cation exchange film or neutral porous diaphragm


49


can block impurities dissolved from the anode


47


and drastically reduce the amount of particles in the plating solution Q on the side of the substrate


48


.





FIG. 8

is a cross-sectional view showing another detailed structure of the plating bath for a substrate plating apparatus of the present invention. The plating bath


41


of

FIG. 8

differs from that in

FIG. 7

on the following points. An insoluble anode


63


is used in place of the soluble anode


47


, while a diaphragm


61


formed of a neutral porous diaphragm or an ion exchange film is disposed between the anode


63


and substrate


48


to divide the plating bath


41


into the substrate region


44


-


1


and the anode region


44


-


2


. Further, a plate


62


is provided in contact with the diaghram


61


and serves as a current shielding plate for generating a uniform primary current distribution between the anode


63


and substrate


48


.




Although not shown in the diagrams, the plating bath


41


is provided with separate circulating pumps for separately circulating plating solution in the substrate region


44


-


1


and in the anode region


44


-


2


.




As described above, a diaphragm


61


formed of a neutral porous diaphragm or ion exchange film is disposed between the anode


63


and substrate


48


. Since the fresh plating solution does not contact the surface of the anode


63


, the additives are not resolved. As a result, the life of the plating solution Q can be lengthened.




By circulating the plating solution in the substrate region


44


-


1


and anode region


44


-


2


using separate circulating pumps, plating solution flowing through the anode region


44


-


2


flows separately from plating solution flowing over the surface of the substrate


48


and flows out of the main section


45


together with O


2


gas produced from the surface of the anode


63


.




Next, the remarkable advantages of the substrate plating apparatus according to the present invention will be described.




Providing an ion exchange film or neutral porous diaphragm between the substrate and the anode has an equivalent effect to increase the electrical resistance in the plating solution between the substrate and the anode. Accordingly, it is possible to achieve a uniform primary current distribution between the substrate and the anode, even if the distance between the two is small, thereby forming a uniform plating film on the surface of the substrate. As a result, manufacturers can attempt to decrease the size of the substrate plating apparatus.




By using a soluble anode and an ion exchange film that only allows the passage of ions dissolved from the soluble anode, the ion exchange film can block impurities dissolved from the anode. Accordingly, the configuration can drastically reduce the amount of particles in the plating solution on the side of the substrate.




Further the substrate plating apparatus described above is provided with shutoff valves at the inlet and outlet to the anode region, such that plating solution in the anode region passes through the shutoff valve before combining with plating solution flowing out of the substrate region. In other words, plating solution in the anode region and substrate region are combined outside the plating bath. Accordingly, particles emitted from black film deposited on the anode are not combined with plating solution in the substrate region.




Further, a filter provided on the outlet to the anode region removes particles generated in the plating solution from black film deposited on the anode.




Further, a diaphragm formed of a neutral porous diaphragm or ion exchange film is disposed between the anode and substrate. Accordingly, fresh plating solution does not contact the surface of the anode. As a result, resolved additives are not introduced into the substrate region, thereby lengthening the life of the plating solution.




By circulating plating solution in the substrate region and the anode region using separate circulating devices, the plating solution flowing in the anode region flows separately from that plating solution flowing in the substrate region and discharges externally along with O


2


gas produced from the surface of the anode.





FIG. 9

shows a third embodiment of the substrate plating apparatus according to the present invention. As shown in the diagram, a plating bath


110


contains a main section


111


. The main section


111


accommodates a plating retainer


112


for supporting a substrate


113


such as a semiconductor wafer. The plating retainer


112


comprises a retaining member


112


-


1


and a shaft member


112


-


2


. The shaft member


112


-


2


is rotatably supported on the inner walls of a cylindrical guide member


114


via bearings


115


. The guide member


114


and plating retainer


112


can be raised and lowered at a predetermined stroke by a cylinder


116


provided at the top of the main section


111


.




A motor


118


is provided at the inner top of the guide member


114


for rotating the plating retainer


112


in the direction indicated by the arrow A via the shaft member


112


-


2


. A space C formed in the plating retainer


112


contains a substrate presser


117


. The presser


117


comprises a pressing member


117


-


1


and a shaft member


117


-


2


. A cylinder


119


is provided at the inner top of the shaft member


112


-


2


for moving the presser


117


up and down at a predetermined stroke.




An opening


112


-


1




a


is provided at the bottom of the retaining member


112


-


1


and is in liquid communication with the space C. A step


112


-


1




b


as shown in

FIG. 10

is formed at the top of the opening


112


-


1




a


for supporting the edge of the substrate


113


. By supporting the edge of the substrate


113


on the step


112


-


1




b


and applying pressure to the top surface of the substrate


113


with the pressing member


117


-


1


, the edge of the substrate


113


is pinched by the pressing member


117


-


1


and the step


112


-


1




b.


The bottom surface (plating surface of the substrate


113


) is exposed in the opening


112


-


1




a.






A plating solution chamber


120


is provided beneath the retaining member


112


-


1


for enabling the flow of plating solution Q beneath the plating surface of the substrate


113


exposed in the opening


112


-


1




a.


A plating solution supply header


121


is disposed on one side of the main section


111


. A plating solution inlet


122


is formed in the plating solution supply header


121


and is in liquid communication with the plating solution chamber


120


. A plating solution outlet


123


is formed in the opposite side of the main section


111


from the plating solution supply header


121


to enable the outflow of the plating solution Q. A collecting gutter


124


is provided around the outside of the main section


111


for collecting plating solution Q flowing out of the outlet


123


(overflowing from the plating solution chamber


120


).




The plating solution Q collected by the collecting gutter


124


is returned to a plating solution tank


125


. A pump


126


is provided to supply plating solution Q in the plating solution tank


125


to the plating solution supply header


121


. The plating solution Q supplied to the plating solution supply header


121


flows into the plating solution chamber


120


from the inlet


122


, flows horizontally along and in contact with the plating surface of the substrate


113


, then flows out into the collecting gutter


124


via the outlet


123


. In other words, the plating solution Q is cycled between the plating solution chamber


120


and plating solution tank


125


.




The level of the plating solution surface L


Q


shown in the diagram is only slightly higher by a small ΔL than the level L


W


at the substrate


113


in order that the entire plating surface of the substrate


113


is contacted by plating solution Q. The inlet


122


and outlet


123


are disposed one on either side of the substrate


113


and outside the periphery of the substrate


113


. The plating solution Q in the plating solution chamber


120


flows horizontally while contacting the plating surface of the substrate


113


. As shown in

FIG. 10

, an electrical contact


130


is provided for electrically connecting the conducting portion of the substrate


113


on the step


112


-


1




b.


The electrical contact


130


is connected via a brush


127


to the cathode of a power source (not shown) outside of the main section


111


. An anode


128


is provided opposite the substrate


113


below the plating solution chamber


120


. The anode


128


is connected to the anode of the power source. A slit


129


is formed at a predetermined position in the wall of the main section


111


to facilitate insertion and removal of the substrate


113


using a substrate transport jig such as a robot arm.




An ion exchange film or neutral porous diaphragm


134


is disposed on the bottom of the plating solution chamber


120


. An anode chamber


131


is disposed beneath the ion exchange film or neutral porous diaphragm


134


. The anode


128


is provided on the bottom of the anode chamber


131


. Plating liquid or conductive liquid Q′ is introduced from the anode chamber


131


into the plating solution chamber


120


via the ion exchange film or neutral porous diaphragm


134


. A liquid tank


133


contains the plating solution or conductive liquid Q′ and a pump


132


supplies the plating solution or conductive liquid Q′ in the liquid tank


133


to the anode chamber


131


. After flowing through the anode chamber


131


the plating solution or conductive liquid Q′ is recycled to the liquid tank


133


. In other words, plating solution or conductive liquid Q′ is cycled between the anode chamber


131


and liquid tank


133


.




Next, the plating operations will be described for a plating apparatus having the construction described above. First, the cylinder


116


is activated, moving the plating retainer


112


and guide member


114


upward a predetermined amount (to a position in which the substrate


113


supported by the retaining member


112


-


1


corresponds to the slit


129


). At the same time, the cylinder


119


is activated to move the presser


117


up a predetermined amount (such that the pressing member


117


-


1


contacts the top of the slit


129


). At this time, a robot arm or other substrate transporting jig inserts a substrate


113


into the space C of the plating retainer


112


. The substrate


113


is placed on the step


112


-


1




b


with its plating surface facing downward. The cylinder


119


is again driven to move the presser


117


until the bottom of the surface of the pressing member


117


-


1


contacts the top surface of the substrate


113


, effectively pinching the edge of the substrate


113


between the pressing member


117


-


1


and the step


112


-


1




b.






At this time, the cylinder


116


is operated to move the plating retainer


112


and guide member


114


downward until the plating surface of the substrate


113


contacts the plating solution flowing through the plating solution chamber


120


(or until the bottom surface of the substrate


113


is just ΔL lower than the lever of the plating solution surface L


Q


). Next, the motor


118


is driven to move the plating retainer


112


and substrate


113


downward while rotating them at a slow speed. As described above, plating solution Q is supplied from the plating solution tank


125


to the plating solution chamber


120


by means of the pump


126


and circulated in this manner. During this time, the power source applies a predetermined voltage between the anode


128


and electrical contact


130


to create a plating current from the anode


128


to the substrate


113


and form a plating film on the plating surface of the substrate


113


.




During the plating process, the motor


118


drives the plating retainer


112


and substrate


113


to rotate at the low speed of 1-10 rpm. By rotating the substrate


113


at this low rotational speed, it is possible to avoid causing adverse effects to the flow of the plating solution Q in the plating solution chamber


120


(level to the plating surface of the substrate


113


), that is, to avoid disturbing the uniform relative speed between the plating surface and plating solution. The rotation also eliminates differences in film thickness generated on the upstream and downstream sides of the flow of plating solution to form a plating film of uniform thickness on the plating surface of the substrate


113


.




When the plating process is completed, the cylinder


116


is driven to move the plating retainer


112


and substrate


113


upward until the bottom surface of the retaining member


112


-


1


is above the plating solution level L


Q


. At this point, the motor


118


spins the plating retainer


112


and substrate


113


at a high speed to shake off plating solution deposited on the plating surface of the substrate and bottom surface of the retaining member


112


-


1


using centrifugal force. After shaking off the plating solution, the substrate


113


is raised until positioned at the slit


129


. Next, the cylinder


119


is operated to raise the pressing member


117


-


1


, releasing the substrate


113


such that the substrate


113


rests on the step


112


-


1




b.


Here, the robot arm or other substrate transport jig is inserted in the space C of the plating retainer


112


, and picks up and removes the substrate


113


from the slit


129


.




As described above, the anode chamber


131


is disposed beneath the inlet


122


and separated from the same by the ion exchange film or neutral porous diaphragm


134


. Plating liquid or conductive liquid Q′ is flowed through the anode chamber


131


. With this configuration, it is possible to prevent resolution of additives from oxidizing on the surface of the anode


128


when using an insoluble anode


128


. Further, oxide gas generated from the surface of the anode


128


is blocked by the ion exchange film or neutral porous diaphragm


134


and prevented from reaching the plating surface of the substrate


113


. Accordingly, this construction can prevent unusual consumption of additives in the plating solution Q, as well as the formation of fine holes and channels in the plating surface of the substrate caused by oxygen gas and the generation of plating defects in the surface.




With the construction described above, the plating solution Q flows through the plating solution chamber


120


level to the plating surface of the substrate


113


. This method enables the plating bath


110


to be produced with a smaller depth than plating baths using the conventional face down method that shoots a plating solution jet directly at the substrate. Accordingly, a plurality of plating baths


110


can be provided next to each other.




As described above, a flattened plating solution chamber is provided below the plating surface of the substrate and a plating solution inlet for allowing plating solution to flow into the plating solution chamber and a plating solution outlet to enable plating solution to flow out of the chamber are provided on either side of the substrate and outside the periphery of the substrate. With this configuration, plating in the plating solution chamber flows level and in contact with the plating surface of the substrate. Accordingly, the relative speed of the plating solution to the plating surface is uniform across the entire surface of the substrate. Additives in the plating solution are uniformly adsorbed, improving implanting properties for fine holes and channels in the substrate to achieve a uniform plating thickness. Further, since the plating solution flows level to the plating surface on the bottom of the substrate, the depth of the plating bath can be made small.




Also, an anode chamber is provided below the plating solution chamber and separated from the plating solution chamber by an ion exchange film or neutral porous diaphragm, through which plating solution or another conductive liquid flows. This configuration prevents the surface of the anode from being oxidized and prevents unusual consumption of additives in the plating solution. Further, oxygen gas generated from the surface of the anode is prevented by the ion exchange film or neutral porous diaphragm from reaching the substrate. Accordingly, this configuration can prevent defects of plating layer from forming plating in fine holes and channels in the surface of the substrate.




By providing a mechanism for rotating the substrate, the substrate can be rotated in the plating solution at a slow speed with the plating surface facing downward to form a plating film of uniform thickness on the substrate. After the plating is completed, the substrate can be raised out of the plating solution and rotated at a fast speed to shake off excess plating solution into the plating bath, thereby reducing the amount of contamination from plating solution on the outside of the plating bath.




Further, the overall surface configuration of the plating apparatus can be made smaller by providing a plurality of plating baths in a stage. Hence, it is possible to reduce the required installation space.





FIG. 11

shows another embodiment of a plating bath according to the present invention. As shown in the diagram, the structure from plating retainer


112


and above is the same as that in FIG.


9


. Therefore, a description of that section will be omitted. A flattened plating solution chamber


120


is provided below the retaining member


112


-


1


, that is, below the plating surface of the substrate


113


exposed from the opening


112


-


1




a.


A flat plating-solution introducing chamber


122


is disposed beneath the plating solution chamber


120


. A porous plate


121


having a plurality of pores


121




a


separates the plating solution chamber


120


from the plating-solution introducing chamber


122


. A collecting gutter


123


provided around the plating solution chamber


120


collects plating solution Q that overflows from the plating solution chamber


120


.




Plating liquid Q collected from the plating solution chamber


120


is returned to the plating solution tank


125


. The pump


126


pumps plating solution Q from the plating solution tank


125


and introduces it horizontally from both sides into the plating-solution introducing chamber


122


. After being introduced into both sides of the plating-solution introducing chamber


122


, the plating solution Q flows into the plating solution chamber


120


via the pores


121




a


formed in the porous plate


121


becoming jets perpendicular to the substrate


113


. The distance between the substrate


113


and the porous plate


121


is 5-15 mm. The jet streams of plating solution Q forced through the pores


121




a


are maintained in a uniform upward direction to contact the plating surface of the substrate


113


. Plating solution Q that overflows from the plating solution chamber


120


is collected by the collecting gutter


123


and returned to the plating solution tank


125


. In other words, plating solution Q is circulated between the plating solution chamber


120


and the plating solution tank


125


.




The plating bath


110


is further provided with the anode chamber


131


below the plating-solution introducing chamber


122


for introducing plating solution or conductive liquid Q′ into the plating-solution introducing chamber


122


via an ion exchange film or neutral porous diaphragm


130


and the anode


128


on the bottom of the anode chamber


131


. The pump


132


introduces plating solution or conductive liquid Q′ from the liquid tank


133


into the anode chamber


131


. After flowing through the anode chamber


131


, the plating solution or conductive liquid Q′ is returned to the liquid tank


133


. In other words, plating solution or conductive liquid Q′ is circulated between the anode chamber


131


and the liquid tank


133


.




As described above, the anode chamber


131


is disposed beneath the plating-solution introducing chamber


122


and separated from the same by the ion exchange film or neutral porous diaphragm


130


. Plating liquid or conductive liquid Q′ is flowed through the anode chamber


131


. With this configuration, it is possible to prevent oxidation on the surface of the anode


128


when using an insoluble anode


128


. Further, oxide gas generated from the surface of the anode


128


is blocked by the ion exchange film or neutral porous diaphragm


130


and prevented from reaching the plating surface of the substrate


113


. Accordingly, this construction can prevent unusual consumption of additives in the plating solution Q, as well as the defects by formation of plating layer at fine holes and channels in the plating surface of the substrate caused by oxygen gas.




As described above, the plating bath is provided with a plating solution chamber formed between the substrate and the porous plate opposite and separated a predetermined distance below the substrate; and a flattened plating-solution introducing chamber formed below the porous plate. The plating solution flows horizontally into the plating-solution introducing chamber and is forced through the plurality of holes in the porous plate to form flows of plating solution perpendicular to the plating surface of the substrate. Accordingly, by appropriately setting the distance between the porous plate and the substrate, it is possible to form a flattened plating bath with a shallow depth, without requiring to increase the distance above the plating solution or to rectify the flow.




An anode chamber is provided below the plating-solution introducing chamber and separated from the introducing chamber by an ion exchange film or neutral porous diaphragm. Plating solution or another conductive liquid is flowed through the anode chamber. This configuration prevents the anode surface from being oxidized and prevents the unusual consumption of additives in the liquid. Further, generated oxygen gas is blocked by the ion exchange film or neutral porous diaphragm and prevented from contacting the substrate, thereby preventing defects being formed in the plating layer at fine holes and channels in the surface of the substrate.




By providing a mechanism for rotating the substrate in the plating solution at a slow speed with the plating surface facing downward, the plating surface of the substrate is uniformly contacted by plating solution to form a plating film of uniform thickness on the substrate. After the plating process is completed, the mechanism lifts the substrate out of the plating solution and rotates the substrate at a fast speed to shake off excess plating solution into the plating bath, thereby reducing the amount of contamination from plating solution on the outside of the plating bath.




By setting the distance between the substrate and porous plate at 5-15 mm, the rotation of the substrate forces liquid toward the periphery of the substrate by the viscosity of the liquid. This effect lowers the pressure toward the center of the substrate and increases the flow of liquid through the center of the porous plate, thereby achieving a uniform vertical component of velocity over the entire surface of the substrate. Accordingly, it is possible to produce a plating bath with a shallow depth, since there is no need to increase the depthwise distance for the ascending liquid current as in the prior art.




The footstep of the overall apparatus can be decreased by providing a plurality of plating baths next to one another in a stage, thereby reducing the amount of space required for installation.





FIGS. 12A and 12B

show the overall structure of a plating apparatus employing the plating baths


110


described above.

FIG. 12A

is a plan view of the apparatus, while

FIG. 12B

is a side view. As shown the diagrams, a plating apparatus


140


comprises a loading section


141


, an unloading section


142


, cleaning and drying vessels


143


, a loading stage


144


, a coarse washing vessel


145


, plating stages


146


, preprocess vessesl


147


, a first robot


148


, and a second robot


149


. Each of the plating stages


146


includes a combination of two plating baths


110


as configured in

FIG. 9

or FIG.


11


. Hence, the entire plating apparatus is provided with four plating baths


110


. This construction is possible because the plating bath


110


has a more shallow depth than the plating bath of the prior art.




With the plating apparatus


140


described above, substrates


113


are contained in a cassette deposited on the loading section


141


. The first robot


148


extracts one substrate


113


at a time and transfers it to the loading stage


144


. Here, the second robot


149


transfers the substrate


113


at the loading stage


144


to one of the preprocess vessels


147


, where the substrate


113


is preprocessed. Next, the second robot


149


transfers the preprocessed substrate


113


to a plating bath


110


in one of the plating stages


146


, where the substrate


113


undergoes a plating process. After the plating process is completed, the second robot


149


transfers the substrate


113


to the coarse washing vessel


145


for washing. Next, the first robot


148


transfers the substrate


113


to the cleaning and drying vessels


143


to be washed and dried, after which the first robot


148


transfers the substrate


113


to the unloading section


142


.




Since the plating bath


110


of the present invention is provided with a plating solution chamber


120


beneath the plating surface of the substrate


113


through which plating solution Q flows horizontally across the plating surface, the depth of the plating bath


110


can be shallow, enabling a plurality (two in this case) of plating baths


110


to be provided together. The installation space of the entire plating apparatus can be decreased since the depth of two plating baths


110


is equivalent to one plating bath using the face down method of the prior art. In other words, when using plating baths of the prior art to construct a plating apparatus with four plating baths, only one plating bath can be provided in each plating stage


146


. Therefore, the installation area required for the plating stages


146


would be twice as large as that shown in FIG.


12


B.




While the invention has been described in detail with reference to specific embodiments thereof, it would be apparent to those skilled in the art that many modifications and variations may be made therein without departing from the scope of the invention, the scope of which is defined by the attached claims. For example, the embodiments described above used electrolytic plating in the plating apparatus of the present invention, but the present invention can also apply to an apparatus conducting electroless plating. In addition to using copper sulfate plating solution for the plating solution Q to conduct copper plating, it is also possible to use other plating solution to conduct a plating process with a different metal.




Industrial Applicability




The present invention is applicable to the semiconductor industry, since the substrate plating can be conducted so as to form a fine wiring layer on a semiconductor wafer.



Claims
  • 1. A substrate plating apparatus for plating a substrate in a plating bath containing a plating solution when an anode is disposed in the plating bath opposite the substrate, the substrate plating apparatus comprising:an ion exchange film or neutral porous diaphragm to be disposed between the substrate and anode in the plating bath for dividing the plating bath into a substrate region and an anode region; and shutoff valves to serve as an inlet and outlet for plating solution in the anode region, wherein plating solution from the anode region is to flow through one of the shutoff valves and merge with plating solution flowing from the substrate region.
  • 2. The substrate plating apparatus according to claim 1, wherein the anode is a soluble anode and the ion exchange film is a cationic exchange film through which only ions dissolved from the soluble anode can pass.
  • 3. The substrate plating apparatus according to claim 1, further comprising a filter in fluid communication with the one of the shutoff valves for filtering plating solution flowing from the anode region.
  • 4. A substrate plating apparatus for plating a substrate in a plating bath containing a plating solution when an insoluble anode is disposed in the plating bath opposite the substrate, the substrate plating apparatus comprising:a diaphragm formed of an ion exchange film or neutral porous diaphragm to be disposed between the substrate and the insoluble anode in the plating bath for dividing the plating bath into a substrate region and an anode region; and a plate that contacts the ion exchange film or neutral porous diaphragm and is to serve as a shielding plate for correcting primary current distribution between the insoluble anode and substrate.
  • 5. The substrate plating apparatus according to claim 4, further comprising circulating devices for separately circulating the plating solution in the substrate region and anode region.
  • 6. A substrate plating apparatus for plating a substrate in a plating bath containing plating solution when an anode is disposed in the plating bath opposite the substrate, the plating apparatus comprising:an ion exchange film or neutral porous diaphragm to be disposed between the substrate and anode in the plating bath, whereby the ion exchange film or neutral porous diaphragm is to divide the plating bath into a substrate region and an anode region; a plating solution chamber to be disposed under a plating surface of the substrate when the substrate is disposed with its plating surface facing downward; a plating solution inlet and plating solution outlet to be disposed in opposition to each other one on either side of the periphery of the substrate, with the plating solution inlet enabling an inflow of plating solution into the plating solution chamber and the plating solution outlet enabling an outflow of plating solution from the plating solution chamber, such that plating solution in the plating solution chamber can flow parallel to and in contact with the plating surface of the substrate; an anode chamber provided under the plating solution chamber via the ion exchange film or neutral porous diaphragm, with plating solution or another conductive liquid to flow in the anode chamber; and an anode disposed at the bottom of the anode chamber to oppose the substrate via the ion exchange film or neutral porous diaphragm.
  • 7. The substrate plating apparatus according to claim 6, further comprising a substrate rotating mechanism for rotating the substrate while the plating surface of the substrate faces downward in the plating bath.
  • 8. The substrate plating apparatus according to claim 7, wherein the substrate is to be rotated by the substrate rotating mechanism in the plating bath at a speed of 1-10 rpm.
  • 9. The substrate plating apparatus according to claim 6, further comprising a plating stage to be provided with a plurality of plating baths.
  • 10. A substrate plating apparatus for plating a substrate in a plating bath containing plating solution when an anode is disposed in the plating bath opposite the substrate and the substrate has its plating surface facing downward, the plating apparatus comprising:an ion exchange film or neutral porous diaphragm to be disposed between the substrate and anode in the plating bath, whereby the ion exchange film or neutral porous diaphragm is to divide the plating bath into a substrate region and an anode region; a plating solution chamber to be formed between the substrate and the ion exchange film or neutral porous diaphragm; a porous plate having a plurality of holes; a plating solution introducing chamber formed below the porous plate, wherein plating solution is to be introduced into the plating solution introducing chamber in a horizontal direction and forced through the holes in the porous plate to form flows orthogonal to the plating surface of the substrate; an anode chamber provided under the plating solution chamber via the ion exchange film or neutral porous diaphragm; and an anode disposed at the bottom of the anode chamber to oppose the substrate via the ion exchange film or neutral porous diaphragm and the porous plate, wherein the plating solution or another conductive liquid is to flow in the anode chamber.
  • 11. The substrate plating apparatus according to claim 10, further comprising a substrate rotating mechanism for rotating the substrate while the plating surface of the substrate faces downward in the plating bath.
  • 12. The substrate plating apparatus according to claim 10, wherein the distance between the substrate and the porous plate is to be 5-15 mm.
  • 13. The substrate plating apparatus according to claim 10, further comprising a plating stage to be provided with a plurality of plating baths.
  • 14. A substrate plating apparatus for plating a substrate, comprising:a plating bath capable of containing a plating solution when an insoluble anode is disposed in the plating bath opposite a plating surface of a substrate when the substrate is disposed with the plating surface facing downward; and a circulating vessel or dummy vessel provided separate from the plating bath, with a soluble anode and a cathode being disposed in the circulating vessel or dummy vessel, and an anion exchange film or selective cation exchange film being disposed between the soluble anode and the cathode for isolating the soluble anode and cathode, wherein metal ions are to be generated in the circulating vessel or dummy vessel by flowing current between the soluble anode and the cathode, and the generated metal ions are to be supplied to the plating bath.
  • 15. The substrate plating apparatus according to claim 14, further comprising a sulfuric acid source to supply sulfuric acid so as to maintain liquid at a uniform conductivity in the circulating vessel or dummy vessel.
  • 16. The substrate plating apparatus according to claim 15, further comprising a substrate rotating mechanism for rotating the substrate while the plating surface of the substrate faces downward in the plating bath.
  • 17. The substrate plating apparatus according to claim 15, further comprising a plating stage provided with a plurality of plating baths.
  • 18. The substrate plating apparatus according to claim 14, further comprises a plurality of plating baths, and an amount of current to be flowed between the substrate and the insoluble anode in each of the plating baths is to be equal to an amount of current flowed between the soluble anode and the cathode in the circulating vessel or dummy vessel.
  • 19. The substrate plating apparatus according to claim 14, wherein the insoluble anode in the plating bath is to be connected to the cathode in the circulating vessel or dummy vessel when the substrate in the plating bath is connected to the soluble anode in the circulating vessel or dummy vessel, and the current to be flowed between the insoluble anode and the substrate in the plating bath is equal to the current to be flowed between the soluble anode and the cathode in the circulating vessel or dummy vessel.
  • 20. A substrate plating apparatus for plating a substrate, comprising:a plating bath to contain a plating solution when an anode is disposed in the plating bath opposite a substrate and the substrate is disposed with its plating surface facing downward; and an ion exchange film or neutral porous diaphragm to be disposed between the substrate and the anode in the plating bath, whereby the ion exchange film or neutral porous diaphragm is to divide the plating bath into a substrate region and an anode region.
  • 21. The substrate plating apparatus according to claim 20, wherein the anode is a soluble anode and the ion exchange film is a cationic exchange film through which only ions dissolved from the soluble anode can pass.
  • 22. The substrate plating apparatus according to claim 20, further comprising shutoff valves to serve as an inlet and outlet for plating solution in the anode region, wherein plating solution from the anode region is to flow through one of the shutoff valves and merge with plating solution flowing from the substrate region.
  • 23. The substrate plating apparatus according to claim 22, further comprising a filter in fluid communication with the one of the shutoff valves.
  • 24. A substrate plating apparatus for plating a substrate, comprising:a plating bath to contain a plating solution when an insoluble anode is disposed in the plating bath opposite a substrate and the substrate is disposed with its plating surface facing downward; and an ion exchange film or neutral porous diaphragm to be disposed between the substrate and the insoluble anode in the plating bath, whereby the ion exchange film or neutral porous diaphragm is to divide the plating bath into a substrate region and an insoluble anode region.
  • 25. The substrate plating apparatus according to claim 24, further comprising a plate that contacts the ion exchange film or neutral porous diaphragm and is to serve as a shielding plate for correcting primary current distribution between the insoluble anode and substrate.
  • 26. The substrate plating apparatus according to claim 24, further comprising circulating devices for separately circulating the plating solution in the substrate region and the insoluble anode region.
  • 27. The substrate plating apparatus according to claim 24, wherein plating bath comprises:a plating solution chamber to be disposed under the plating surface of the substrate; a plating solution inlet and plating solution outlet to be disposed in opposition to each other one on either side of the periphery of the substrate, with the plating solution inlet enabling an inflow of plating solution into the plating solution chamber and the plating solution outlet enabling an outflow of plating solution from the plating solution chamber, such that plating solution in the plating solution chamber can flow parallel to and in contact with the plating surface of the substrate; an anode chamber provided under the plating solution chamber via the ion exchange film or neutral porous diaphragm, wherein plating solution or another conductive liquid is to flow in the anode chamber; and an anode disposed at the bottom of the anode chamber to oppose the substrate via the ion exchange film or neutral porous diaphragm.
  • 28. The substrate plating apparatus according to claim 24, further comprising a substrate rotating mechanism for rotating the substrate while the plating surface of the substrate faces downward in the plating bath.
  • 29. The substrate plating apparatus according to claim 28, wherein the substrate is to be rotated by the substrate rotating mechanism in the plating bath at a speed of 1-10 rpm.
  • 30. The substrate plating apparatus according to claim 24, further comprising a plating stage provided with a plurality of plating baths.
  • 31. The substrate plating apparatus according to claim 24, wherein the plating bath comprises:a plating solution chamber to be formed between the substrate and the ion exchange film or neutral porous diaphragm; a porous plate having a plurality of holes; a plating solution introducing chamber formed below the porous plate, wherein plating solution is to be introduced into the plating solution introducing chamber in a horizontal direction and forced through the holes in the porous plate to form flows orthogonal to the plating surface of the substrate; an anode chamber provided under the plating solution chamber via the ion exchange film or neutral porous diaphragm; and an anode disposed at the bottom of the anode chamber to oppose the substrate via the ion exchange film or neutral porous diaphragm and the porous plate, wherein plating solution or another conductive liquid is to flow in the anode chamber.
  • 32. A substrate plating apparatus for plating a substrate, comprising:a loading section for loading a substrate; a robot for conveying the substrate; a plating bath capable of containing plating solution when an anode is disposed in the plating bath opposite the substrate; a circulating vessel or dummy vessel provided separate from the plating bath, with a soluble anode and a cathode being disposed in the circulating vessel or dummy vessel, and an anion exchange film or selective cation exchange film being disposed between the soluble anode and the cathode for isolating the soluble anode and the cathode, wherein metal ions are to be generated by flowing current between the soluble anode and the cathode, and the generated metal ions are to be supplied to the plating bath; a coarse washing vessel for coarsely washing the substrate after a plating process is completed; and a cleaning and drying vessel for cleaning and drying the substrate after coarse washing of the substrate is completed.
  • 33. A substrate plating apparatus for plating a substrate, comprising:a loading section for loading a substrate; a robot for conveying the substrate; a plating bath capable of containing plating solution when an anode is disposed in the plating bath opposite the substrate; an anion exchange film or selective cation exchange film to be disposed between the anode and the substrate for isolating the anode and the substrate; a coarse washing vessel for coarsely washing the substrate after a plating process is completed; and a cleaning and drying vessel for cleaning and drying the substrate which is plated in the plating bath.
  • 34. A substrate plating apparatus for plating a substrate, comprising:a loading section for loading a substrate; a robot for conveying the substrate; a plating bath capable of containing plating solution when an insoluble anode is disposed in the plating bath opposite the substrate; an anion exchange film or selective cation exchange film to be disposed between the insoluble anode and the substrate for isolating the insoluble anode and the substrate; a coarse washing vessel for coarsely washing the substrate after a plating process is completed; and a cleaning and drying vessel for cleaning and drying the substrate after coarse washing of the substrate is completed.
Priority Claims (4)
Number Date Country Kind
10-254395 Sep 1998 JP
10-254396 Sep 1998 JP
11-064987 Mar 1999 JP
11-064988 Mar 1999 JP
PCT Information
Filing Document Filing Date Country Kind
PCT/JP99/04861 WO 00
Publishing Document Publishing Date Country Kind
WO00/14308 3/16/2000 WO A
US Referenced Citations (4)
Number Name Date Kind
3450625 Ramsey et al. Jun 1969 A
4469564 Okinaka et al. Sep 1984 A
4906340 Brown Mar 1990 A
5009755 Shor Apr 1991 A
Foreign Referenced Citations (4)
Number Date Country
2-70087 Mar 1990 JP
3-10099 Jan 1991 JP
5-302199 Nov 1993 JP
10-121297 May 1998 JP