JP4233331B2 - Electrolytic machining method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrolytic processing method and apparatus, and more particularly to an electrolytic process used for processing a conductive material formed on the surface of a substrate such as a semiconductor wafer or removing impurities attached to the surface of the substrate. The present invention relates to a processing method and apparatus.
[0002]
[Prior art]
In recent years, as a wiring material for forming a circuit on a substrate such as a semiconductor wafer, instead of aluminum or an aluminum alloy, a movement using copper (Cu) having low electrical resistivity and high electromigration resistance has become prominent. . This type of copper wiring is generally formed by embedding copper in a fine recess provided on the surface of the substrate. As a method of forming this copper wiring, there is a method such as chemical vapor deposition (CVD), sputtering and plating, but in any case, copper is formed on almost the entire surface of the substrate, Unnecessary copper is removed by chemical mechanical polishing (CMP).
[0003]
FIG. 1A to FIG. 1C show a manufacturing example of this type of copper wiring board W in the order of steps. As shown in FIG. 1A, SiO is formed on a conductive layer 1a on a semiconductor substrate 1 on which a semiconductor element is formed. ₂ An insulating film 2 such as an oxide film or a low-k material film is deposited, and a contact hole 3 and a wiring groove 4 are formed by a lithography / etching technique. A barrier film 5 made of TaN or the like is formed thereon, and a seed layer 7 is formed thereon as a power feeding layer for electrolytic plating by sputtering, CVD, or the like.
[0004]
Then, by copper plating on the surface of the substrate W, as shown in FIG. 1B, the contact holes 3 and the grooves 4 of the semiconductor substrate 1 are filled with copper, and a copper film is formed on the insulating film 2. 6 is deposited. Thereafter, the copper film 6 and the seed layer 7 on the insulating film 2 are removed by chemical mechanical polishing (CMP), and the surface of the copper film 6 filled in the contact hole 3 and the wiring groove 4 and the insulating film 2 are removed. The surface of the surface is made substantially flush. As a result, a wiring made of the copper film 6 is formed as shown in FIG.
[0005]
In recent years, as the miniaturization and high precision have progressed in the components of all devices, and the manufacturing in the submicron region has become common, the influence of the processing method itself on the characteristics of the material has been increasing. Under such circumstances, the machining method in which the tool removes the workpiece while physically destroying it, as in conventional machining, because many defects are generated in the workpiece by machining. As a result, the properties of the workpiece are deteriorated. Therefore, it becomes a problem how the processing can be performed without impairing the characteristics of the material.
[0006]
Special processing methods developed as means for solving this problem include chemical polishing, electrolytic processing, and electrolytic polishing. In contrast to conventional physical processing, these processing methods perform removal processing and the like by causing a chemical dissolution reaction. Therefore, defects such as work-affected layers and dislocations due to plastic deformation do not occur, and the problem of performing processing without impairing the properties of the above-described materials is achieved.
[0007]
In recent years, white metal or its oxide has been proposed as an electrode material for forming a capacitor using a ferroelectric on a semiconductor substrate. Among these, ruthenium has a good film forming property, and thus is being studied as a highly feasible material.
[0008]
Here, ruthenium deposited or adhered to the peripheral edge and the back surface of the substrate other than the circuit forming portion is not only unnecessary, but also causes cross-contamination in the subsequent substrate transport, storage, and various processing steps. Degradation of the dielectric performance can also occur. Therefore, it is necessary to completely remove these after the ruthenium film forming process and the ruthenium film are subjected to some treatment. Furthermore, for example, when ruthenium is used as the electrode material of the capacitor, a step of removing a part of the ruthenium film formed on the circuit forming portion is necessary.
[0009]
[Problems to be solved by the invention]
For example, the CMP process generally requires a considerably complicated operation, is complicated in control, and has a considerably long processing time. Furthermore, not only is it necessary to sufficiently perform post-cleaning of the substrate after polishing, but there are also problems such as a large load for waste liquid treatment of slurry and cleaning liquid. Therefore, there is a strong demand for omitting CMP itself or reducing this load. In the future, it is expected that the insulating film will also be changed to a low-k material having a low dielectric constant. This low-k material is weak in strength and cannot withstand the stress caused by CMP. Therefore, there is a demand for a process that enables planarization without applying excessive stress to the substrate such as CMP.
[0010]
In addition, a process of cutting with CMP while plating, such as chemical mechanical electropolishing, has been announced, but by adding machining to the plating growth surface, it will also promote abnormal growth of plating. , Causing problems with film quality.
[0011]
The present invention has been made in view of such problems of the prior art. For example, the conductive material provided on the substrate surface is flattened while omitting the CMP process itself or reducing the load of the CMP process as much as possible. It is another object of the present invention to provide an electrolytic processing method and apparatus capable of processing (or cleaning) deposits adhered to the surface of a workpiece such as a substrate.
[0012]
[Means for Solving the Problems]
In order to solve such problems in the prior art, the first aspect of the present invention is: Almost disk-shaped A machining electrode; Disc shaped Arranged between a feeding electrode that feeds power to the workpiece, a holding portion that holds the workpiece and contacts or approaches the machining electrode, and at least one of the workpiece and the machining electrode or the feeding electrode An ion exchanger, a power source that applies a voltage between the processing electrode and the power supply electrode, and a workpiece on which the ion exchanger is disposed and at least one of the processing electrode or the power supply electrode Ultrapure water, pure water, or a liquid with an electric conductivity of 500 μS / cm or less And a drive unit that relatively moves the workpiece held by the holding unit and the machining electrode in a state where the center of motion of the machining electrode is located inside the outer diameter of the workpiece. And be prepared The diameter of the machining electrode is larger than the sum of the relative movement distance between the workpiece and the machining electrode and the diameter of the workpiece, and smaller than twice the diameter of the workpiece. This is an electrolytic processing apparatus.
[0013]
The second aspect of the present invention is: It is substantially disc-shaped and has a diameter that is larger than the sum of the relative movement distance between the workpiece and the machining electrode described below and the workpiece diameter, and smaller than twice the workpiece diameter. With machining electrode Disc shaped A power supply electrode for supplying power to the work piece, an ion exchanger disposed between the work piece and at least one of the processing electrode or the power supply electrode, and the work electrode and the power supply electrode between A voltage is applied to bring the workpiece into contact with or close to the machining electrode, and between the workpiece on which the ion exchanger is disposed and at least one of the machining electrode or the feeding electrode. Ultrapure water, pure water, or a liquid with an electric conductivity of 500 μS / cm or less In a state where the center of motion of the machining electrode is always located inside the outer diameter of the workpiece, the workpiece and the machining electrode are moved relative to each other to machine the surface of the workpiece. This is an electrolytic processing method.
[0014]
2 and 3 show the processing principle of the present invention. In FIG. 2, an ion exchanger 12 a attached to the machining electrode 14 and an ion exchanger 12 b attached to the feeding electrode 16 are brought into contact with or close to the surface of the workpiece 10, and the machining electrode 14 and the feeding electrode 16 are brought into contact with each other. A state in which a fluid 18 such as ultrapure water is supplied from the fluid supply unit 19 between the machining electrode 14 and the power supply electrode 16 and the workpiece 10 while a voltage is applied therebetween via the power supply 17 is shown. FIG. 3 shows that the ion exchanger 12a attached to the machining electrode 14 is brought into contact with or close to the surface of the workpiece 10, and the feeding electrode 16 is brought into direct contact with the workpiece 10, so that the machining electrode 14 and the feeding electrode 16 A state in which a fluid 18 such as ultrapure water is supplied from the fluid supply unit 19 between the machining electrode 14 and the workpiece 10 while a voltage is applied via the power source 17 during the period is shown.
[0015]
When using a liquid having a high resistance value, such as ultrapure water, it is preferable to “contact” the ion exchanger 12a with the surface of the workpiece 10, and thus the ion exchanger 12a is covered with the ion exchanger 12a. By bringing the workpiece 10 into contact with the surface, the electrical resistance can be reduced, the applied voltage can be reduced, and the power consumption can be reduced. Therefore, the “contact” in the processing according to the present invention is not “pressing” in order to give physical energy (stress) to the workpiece as in CMP, for example.
[0016]
Thereby, the water molecules 20 in the fluid 18 such as ultrapure water are dissociated into hydroxide ions 22 and hydrogen ions 24 by the ion exchangers 12a and 12b. For example, the generated hydroxide ions 22 are converted into workpieces. 10 is supplied to the surface of the workpiece 10 facing the machining electrode 14 by the electric field between the machining electrode 14 and the flow of a fluid 18 such as ultrapure water, and hydroxylated in the vicinity of the workpiece 10 here. The density of the object ions 22 is increased, and the atoms 10a of the workpiece 10 and the hydroxide ions 22 are reacted. The reactant 26 produced by the reaction is dissolved in the ultrapure water 18 and removed from the workpiece 10 by the flow of the fluid 18 such as ultrapure water along the surface of the workpiece 10. Thereby, the removal process of the surface layer of the to-be-processed object 10 is performed.
[0017]
As described above, this processing method purely performs the removal processing of the work piece only by the electrochemical interaction with the work piece, and the physical interaction between the polishing member such as CMP and the work piece. The processing principle is different from processing by mixing action and chemical interaction with chemical species in the polishing liquid. In this method, since the portion of the workpiece 10 that faces the machining electrode 14 is machined, the surface of the workpiece 10 can be machined into a desired surface shape by moving the machining electrode 14.
[0018]
In addition, since the electrolytic processing apparatus according to the present invention performs removal processing of a workpiece only by a dissolution reaction by electrochemical interaction, physical interaction and polishing between a polishing member such as CMP and the workpiece. The processing principle is different from processing by mixing chemical interaction with chemical species in the liquid. Therefore, it is possible to perform removal processing without damaging the properties of the material. For example, even a material with low mechanical strength, such as the Low-k material described above, can be removed without causing physical interaction. Processing is possible. Further, even when compared with an electrolytic processing apparatus using a normal electrolytic solution, a fluid of 500 μS / cm or less, preferably pure water, and more preferably ultrapure water is used as the processing solution, so that contamination on the surface of the workpiece is also caused. It can be greatly reduced, and processing of waste liquid after processing becomes easy.
[0019]
In electrolytic machining, the amount of machining is determined by the frequency of machining electrodes on the workpiece and the applied voltage. Therefore, when trying to process the entire surface of the workpiece uniformly and flatly, it is necessary to make the presence frequency of the processing electrode uniform over the entire surface of the workpiece. For example, if the work piece is disk-shaped and the machining electrode is circular and its diameter is smaller than the diameter of the work piece, such as a semiconductor substrate, the work piece and the work electrode are moved relative to each other. Thus, the entire surface of the workpiece can be processed uniformly and uniformly by making the processing electrode exist on the entire surface of the workpiece. However, even in such a method, depending on the position on the surface of the workpiece, the presence frequency of the processing electrode becomes non-uniform, which leads to non-uniformity in the processing amount. If the diameter of the processed electrode is larger than the diameter of the workpiece, the uniformity of the existence frequency of the processed electrode is increased, but the portion to be processed is enlarged, and the weight due to the electrode being a metal is a problem. Become. In addition, due to the contact state between the ion exchanger and the workpiece, the processing amount tends to vary at the contact end.
[0020]
According to the electrolytic processing apparatus according to the present invention, since the processing electrode has a larger diameter than the workpiece, a high processing speed can be obtained, and at the same time, the center of motion of the processing electrode can be obtained during the electrolytic processing. Is located on the inner side of the outer diameter of the workpiece, the frequency of the processing electrodes on the surface of the workpiece can be made as uniform as possible. In addition, since the size of the portion to be processed can be minimized, the entire apparatus can be greatly reduced in size and weight. Here, when the machining electrode performs a scrolling motion, the center of the scrolling motion, and when the machining electrode rotates, the rotational center becomes the motion center of the machining electrode.
[0023]
First of the present invention 3 The aspect of Almost disk-shaped A machining electrode; Disc shaped At least one of a plurality of power feeding electrodes arranged on the outer periphery of the machining electrode, a holding part for holding the workpiece to contact or approach the machining electrode, and the workpiece and the machining electrode or the feeding electrode At least one of an ion exchanger disposed between the power supply for applying a voltage between the processing electrode and the power supply electrode, a workpiece on which the ion exchanger is disposed, and a processing electrode or a power supply electrode. Between Ultrapure water, pure water, or a liquid with an electric conductivity of 500 μS / cm or less And a drive unit that relatively moves the workpiece held by the holding unit and the machining electrode so that at least one feeding electrode always feeds power to the workpiece. The diameter of the machining electrode is larger than the sum of the relative movement distance between the workpiece and the machining electrode and the diameter of the workpiece, and smaller than twice the diameter of the workpiece. This is an electrolytic processing apparatus.
[0024]
First of the present invention 4 The aspect of It is substantially disc-shaped and is larger than the sum of the relative movement distance between the workpiece and the machining electrode described below and the workpiece diameter, and smaller than twice the workpiece diameter. A plurality of feeding electrodes are arranged on the outer periphery of the machining electrode having a diameter, Disc shaped An ion exchanger is disposed between the workpiece and at least one of the processing electrode or the feeding electrode,
A voltage is applied between the machining electrode and the feeding electrode, the workpiece is brought into contact with or close to the machining electrode, and at least one of the workpiece, the machining electrode, or the feeding electrode on which the ion exchanger is arranged Between Ultrapure water, pure water, or a liquid with an electric conductivity of 500 μS / cm or less And processing the surface of the workpiece by relatively moving the workpiece and the machining electrode so that at least one feeding electrode always feeds power to the workpiece. It is a processing method.
[0025]
Since the workpiece cannot be processed in the region where the power supply electrode exists, the processing speed of the region where the power supply electrode is arranged is lower than the other regions. Therefore, in order to reduce the influence of the power supply electrode on the processing speed, it is preferable to reduce the area (region) occupied by the power supply electrode. From this point of view, in the electrolytic processing apparatus according to the present invention, a plurality of power supply electrodes having a small area are arranged on the outer periphery of the processing electrode, and at least one of them is in contact with or close to the work piece during relative motion to supply power. Like to do. In this way, for example, the region that is not processed can be reduced as compared with the case where the ring-shaped feeding electrode is disposed on the outer peripheral portion of the processing electrode, and the outer peripheral portion of the workpiece remains unprocessed. Can be prevented.
[0026]
In a preferred aspect of the present invention, the processing electrode includes an outer processing electrode positioned on an outer peripheral portion where the feeding electrode is disposed, and an inner processing electrode positioned inside the outer processing electrode. Yes. Preferably, the power source controls a voltage or a current applied to the outer machining electrode and the inner machining electrode, respectively. As described above, the processing electrode is divided into a portion where the power supply electrode affects the processing speed and a portion where the power supply electrode does not affect, and the processing speed in these processing electrodes is independently controlled, so that in the region where the power supply electrode exists. A reduction in processing speed can be prevented. That is, by making the machining speed at the outer machining electrode relatively higher than the machining speed at the inner machining electrode, it is possible to suppress the influence of the presence of the feeding electrode and realize a uniform machining speed on the entire surface of the machining electrode. It becomes possible.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention Embodiment of Electrolytic processing apparatus and substrate processing apparatus incorporating the same In place This will be described in detail with reference to the drawings. In the following description, an example is shown in which a substrate is used as a workpiece and the substrate is processed by an electrolytic processing apparatus, but it goes without saying that the present invention can be applied to other than the substrate.
[0030]
Figure 4 , Group It is a top view which shows the structure of a plate processing apparatus. As shown in FIG. 4, this substrate processing apparatus carries out a cassette containing a substrate W having a copper film 6 as a conductor film (workpiece) on the surface, for example, as shown in FIG. A pair of loading / unloading sections 30 serving as loading / unloading sections, a reversing machine 32 for reversing the substrate W, and an electrolytic processing apparatus 34 are provided. These devices are arranged in series, and a transfer robot 36 as a transfer device that transfers the substrate W between these devices and delivers it is arranged in parallel with these devices. In addition, a monitor unit 38 for monitoring a voltage applied between a machining electrode and a power supply electrode, which will be described later, or a current flowing between them, is adjacent to the load / unload unit 30 during electrolytic machining by the electrolytic machining apparatus 34. Are arranged.
[0031]
FIG. 5 is a longitudinal sectional view schematically showing the electrolytic processing apparatus 34 in the substrate processing apparatus. As shown in FIG. 5, the electrolytic processing apparatus 34 has an arm 40 that can move up and down and can swing in the horizontal direction, and is suspended from a free end of the arm 40 to hold the substrate W downward (face-down). A substrate holding unit 42, a disk-shaped electrode unit 44 disposed below the substrate holding unit 42, and a power source 46 connected to the electrode unit 44 are provided.
[0032]
The arm 40 is attached to the upper end of the swing shaft 50 connected to the swing motor 48, and swings in the horizontal direction as the swing motor 48 is driven. The swing shaft 50 is connected to a ball screw 52 extending in the vertical direction, and moves up and down together with the arm 40 as the vertical movement motor 54 connected to the ball screw 52 is driven.
[0033]
The substrate holding unit 42 is connected to a rotation motor 56 as a first driving unit that relatively moves the substrate W held by the substrate holding unit 42 and the electrode unit 44. It is designed to rotate (spin). Further, as described above, the arm 40 can move up and down and swing in the horizontal direction, and the substrate holder 42 can move up and down and swing in the horizontal direction integrally with the arm 40.
[0034]
A hollow motor 60 as a second drive unit that moves the substrate W and the electrode unit 44 relative to each other is installed below the electrode unit 44, and the main shaft 62 of the hollow motor 60 extends from the center of the main shaft 62. A drive end 64 is provided at an eccentric position. The electrode portion 44 is rotatably connected to the drive end 64 via a bearing (not shown) at the center thereof. Further, three or more rotation prevention mechanisms are provided in the circumferential direction between the electrode portion 44 and the hollow motor 60.
[0035]
FIG. 6A is a plan view showing a rotation prevention mechanism in the present embodiment, and FIG. 6B is a cross-sectional view taken along line AA of FIG. As shown in FIGS. 6A and 6B, there are three or more rotation prevention mechanisms (four in FIG. 6A) in the circumferential direction between the electrode portion 44 and the hollow motor 60. 66 is provided. As shown in FIG. 6B, a plurality of recesses 68 and 70 are formed at equal intervals in the circumferential direction at corresponding positions on the upper surface of the hollow motor 60 and the lower surface of the electrode portion 44. Bearings 72 and 74 are mounted at the locations 68 and 70, respectively. One end portions of two shaft bodies 76 and 78 shifted by a distance e are inserted into the bearings 72 and 74, respectively, and the other end portions of the shaft bodies 76 and 78 are connected to each other by a connecting member 80. Here, the amount of eccentricity of the drive end 64 with respect to the center of the main shaft 62 of the hollow motor 60 is also the same as the distance e described above. Therefore, as the hollow motor 60 is driven, the electrode portion 44 has a revolving motion that does not rotate with a distance e between the center of the main shaft 62 and the drive end 64 as a radius, so-called scroll motion (translational rotation motion). Is supposed to do.
[0036]
FIG. 7 is a longitudinal sectional view schematically showing the substrate holding part 42 and the electrode part 44, and FIG. 8 is a plan view showing the relationship between the substrate W and the electrode part 44. In FIG. 8, the substrate W is indicated by a dotted line. As shown in FIGS. 7 and 8, the electrode portion 44 includes a substantially disc-shaped processing electrode 84 having a diameter larger than the diameter of the substrate W, and a plurality of feeding electrodes arranged on the outer peripheral portion of the processing electrode 84. 86, and an insulator 88 that separates the processing electrode 84 and the power supply electrode 86. As shown in FIG. 7, the upper surface of the processing electrode 84 is covered with an ion exchanger 90, and the upper surface of the power supply electrode 86 is covered with an ion exchanger 92. These ion exchangers 90 and 92 may be integrally formed. These ion exchangers 90 and 92 are not shown in FIG.
[0037]
In the present embodiment, fluid cannot be supplied from above the electrode portion 44 to the upper surface of the electrode portion 44 during electrolytic processing due to the size of the electrode portion 44 and the substrate holding portion 42. Therefore, in this embodiment, as shown in FIGS. 7 and 8, a plurality of fluid supply ports 84a as fluid supply portions for supplying pure water, more preferably ultrapure water, are formed in the processing electrode 84. . In the present embodiment, a plurality of fluid supply ports 84 a are arranged radially with respect to the center of the processing electrode 84. These fluid supply ports 84a are connected to a pure water supply pipe 82 (see FIG. 5) extending inside the hollow portion of the hollow motor 60, and pure water or ultrapure water is connected to the upper surface of the electrode portion 44 from the fluid supply port 84a. Water is supplied.
[0038]
In this embodiment, the machining electrode 84 is connected to the cathode of the power supply 46 and the power supply electrode 86 is connected to the anode of the power supply 46. However, depending on the processing material, the electrode connected to the cathode of the power supply 46 is used as the power supply electrode. The electrode connected to the anode may be a processed electrode. That is, when the material to be processed is, for example, copper, molybdenum, or iron, an electrolytic processing action occurs on the cathode side. Therefore, the electrode connected to the cathode of the power supply 46 becomes the processing electrode, and the electrode connected to the anode serves as the feeding electrode. Become. On the other hand, when the material to be processed is, for example, aluminum or silicon, an electrolytic processing action occurs on the anode side. Therefore, the electrode connected to the anode of the power supply 46 becomes the processing electrode, and the electrode connected to the cathode becomes the power supply electrode.
[0039]
When the workpiece is a conductive oxide such as tin oxide or indium tin oxide (ITO), electrolytic processing is performed after reducing the workpiece. That is, in FIG. 5, the electrode connected to the anode of the power source 46 serves as a reduction electrode, and the electrode connected to the cathode serves as a feeding electrode to reduce the conductive oxide. Subsequently, the reduced conductive oxide is processed using the electrode that was previously the power supply electrode as the processing electrode. Alternatively, the reduction electrode may be a processed electrode by reversing the polarity during reduction of the conductive oxide. Also, the conductive oxide can be removed by using the workpiece as a cathode and facing the anode electrode.
[0040]
In the above example, the copper film 6 as the conductor film formed on the surface of the substrate is subjected to electrolytic processing. However, unnecessary ruthenium (Ru) deposited or adhered to the surface of the substrate. Similarly, the film can be electrolytically processed (etched away) using the ruthenium film as the anode and the electrode connected to the cathode as the processing electrode.
[0041]
During the electrolytic processing, the rotation motor (first driving unit) 56 is driven to rotate the substrate W, and at the same time, the hollow motor 60 (second driving unit) is driven to move the electrode unit 44 to the scroll center O (FIG. 8). Scroll around the center. In this way, the entire surface of the substrate W (copper film 6) is processed by relatively moving the substrate W held by the substrate holding portion 42 and the processing electrode 84 within the scroll region S. The electrolytic processing apparatus 34 of the present embodiment is configured such that the center of motion of the processing electrode 84 (the center of scroll motion O in the present embodiment) is always located inside the outer diameter of the substrate W during this relative motion. ing. In this way, the diameter of the processing electrode 84 is made larger than the diameter of the substrate W, and the center of motion of the processing electrode 84 is always positioned inside the outer diameter of the substrate W, so Can be made as uniform as possible. Moreover, since the size of the electrode portion 44 can be minimized by configuring in this way, the entire apparatus can be greatly reduced in size and weight. The diameter of the processing electrode 84 is preferably larger than the total of the relative movement distance (the scroll radius e in the present embodiment) between the substrate W and the processing electrode 84 and the diameter of the substrate W. It is preferably smaller than twice the diameter.
[0042]
In addition, since the substrate W cannot be processed in the region where the power supply electrode 86 exists, the processing speed of the outer peripheral portion where the power supply electrode 86 is disposed is lower than the other regions. Therefore, in order to reduce the influence of the power supply electrode 86 on the processing speed, it is preferable to reduce the area (region) occupied by the power supply electrode 86. From this point of view, in this embodiment, a plurality of power supply electrodes 86 having a small area are arranged on the outer peripheral portion of the machining electrode 84, and at least one of them is in contact with or close to the substrate W during relative motion. ing. In this way, for example, the region that is not processed can be reduced as compared with the case where the ring-shaped power supply electrode is disposed on the outer peripheral portion of the processing electrode 84, and the outer peripheral portion of the substrate W remains unprocessed. Can be prevented.
[0043]
Next, substrate processing (electrolytic processing) using the substrate processing apparatus in the present embodiment will be described. First, for example, as shown in FIG. 1B, a cassette containing a substrate W on which a copper film 6 is formed as a conductor film (processed portion) on the surface is set in a load / unload unit 30. A single substrate W is taken out by the transfer robot 36. The transfer robot 36 transfers the taken out substrate W to the reversing machine 32 as necessary, and reverses the substrate W so that the surface on which the conductive film (copper film 6) is formed faces downward.
[0044]
The transport robot 36 receives the inverted substrate W, transports it to the electrolytic processing apparatus 34, and holds it by suction on the substrate holder 42. Then, the arm 40 is swung to move the substrate holding portion 42 holding the substrate W to a processing position immediately above the electrode portion 44. Next, the vertical movement motor 54 is driven to lower the substrate holding portion 42, and the substrate W held by the substrate holding portion 42 is brought into contact with or close to the surfaces of the ion exchangers 90 and 92 of the electrode portion 44. In this state, the rotation motor (first driving unit) 56 is driven to rotate the substrate W, and at the same time, the hollow motor 60 (second driving unit) is driven to scroll the electrode unit 44 around the scroll center O. Let At this time, pure water or ultrapure water is supplied between the substrate W and the ion exchangers 90 and 92 from the fluid supply port 84 a of the processing electrode 84.
[0045]
Then, a predetermined voltage is applied between the processing electrode 84 and the feeding electrode 86 by the power source 46, and the substrate W is formed on the processing electrode (cathode) by hydrogen ions or hydroxide ions generated by the ion exchangers 90 and 92. Electrolytic processing of the conductor film (copper film 6) on the surface is performed. At this time, processing proceeds at the portion facing the processing electrode 84, but as described above, the entire surface of the substrate W is processed by moving the substrate W and the processing electrode 84 relative to each other. As described above, the machining electrode 84 has a larger diameter than the substrate W, and the movement center O of the machining electrode 84 is always located inside the outer diameter of the substrate W during the relative movement. Therefore, the existence frequency of the processing electrode 84 on the surface of the substrate W can be made as uniform as possible. Further, with such a configuration, the size of the electrode portion 44 can be minimized, and the entire apparatus can be greatly reduced in size and weight.
[0046]
During the electrolytic machining, the voltage applied between the machining electrode and the feeding electrode or the current flowing therebetween is monitored by the monitor unit 38 to detect the end point (machining end point). That is, when electrolytic processing is performed in the state where the same voltage (current) is applied, a difference occurs in the current (applied voltage) flowing depending on the material. For example, as shown in FIG. 9 (a), when the current flowing when the surface of the substrate W on which the material B and the material A are sequentially formed is subjected to electrolytic processing is monitored, the material A is electrolytically processed. While a constant current flows during the process, the current that flows at the time of transition to processing of a different material B changes. Similarly, even if the voltage is applied between the machining electrode and the feeding electrode, as shown in FIG. 9B, a constant voltage is applied while the material A is electrolytically processed. The voltage applied at the time of shifting to processing of a different material B changes. 9A shows a case where the current is less likely to flow when the material B is electrolytically processed than when the material A is electrolytically processed. FIG. 9B shows the case where the material B is electrolytically processed. Shows an example where the voltage is higher than when the material A is electrolytically processed. Thereby, the end point can be reliably detected by monitoring the change in the current or voltage.
[0047]
In addition, although the monitor part 38 demonstrated the example which monitors the voltage applied between a process electrode and a power supply electrode, or the electric current which flows through this, and detected the process end point, this monitor part 38 is under processing. A change in the state of the substrate may be monitored to detect an arbitrarily set processing end point. In this case, the processing end point indicates a point in time when a desired processing amount is reached or a parameter having a correlation with the processing amount reaches an amount corresponding to the desired processing amount for a specified portion of the processing surface. As described above, even during the machining, the machining end point can be arbitrarily set and detected so that the electrolytic machining can be performed in a multistage process.
[0048]
For example, by detecting the change in friction force caused by the difference in friction coefficient that occurs when the substrate reaches a different material, or by detecting the change in friction force caused by removing the unevenness when flattening the unevenness on the surface of the substrate. It is good also as judging the amount of processing and detecting the processing end point. In addition, heat generated due to electrical resistance of the work surface and heat generated by collision of ions and water molecules moving in the liquid (pure water) between the work surface and the work surface occurred, for example, deposited on the surface of the substrate. When electrolytic polishing of a copper film is performed with constant voltage control, as the electrolytic process proceeds and the barrier layer and the insulating film are exposed, the electrical resistance increases, the current value decreases, and the amount of heat generation decreases sequentially. Therefore, the processing amount may be determined by detecting the change in the heat generation amount, and the processing end point may be detected. Alternatively, it is also possible to detect a change in the intensity of reflected light due to a difference in reflectance that occurs when a different material is reached, detect the film thickness of the film to be processed on the substrate, and thereby detect the processing end point. In addition, an eddy current is generated inside a conductive film such as a copper film, and the eddy current flowing inside the substrate is monitored. For example, a change in frequency is detected to detect the film thickness of the film to be processed on the substrate. Thus, the processing end point may be detected. Further, in the electrolytic machining, the machining rate is determined by the current value flowing between the machining electrode and the feeding electrode, and the machining amount is proportional to the amount of electricity obtained by the product of the current value and the machining time. Therefore, the machining end point may be detected by integrating the amount of electricity obtained by the product of the current value and the machining time, determining that the accumulated value has reached a predetermined value, and determining the machining end point.
[0049]
After completion of the electrolytic processing, the power supply 46 is disconnected, the rotation of the substrate holding part 42 and the scroll movement of the electrode part 44 are stopped, and then the substrate holding part 42 is raised and the arm 40 is moved to transport the substrate W. Transfer to the robot 36. The transport robot 36 that has received the substrate W transports the substrate W to the reversing machine 32 and reverses it as necessary, and then returns the substrate W to the cassette of the load / unload unit 30.
[0050]
Here, the pure water supplied between the substrate W and the ion exchangers 90 and 92 during electrolytic processing is, for example, water having an electric conductivity (1 atm, 25 ° C. converted value, the same shall apply hereinafter) of 10 μS / cm or less. Ultrapure water is, for example, water having an electric conductivity of 0.1 μS / cm or less. In this way, by performing electrolytic processing using pure water or ultrapure water that does not contain an electrolyte, it is possible to prevent the impurities such as the electrolyte from adhering to or remaining on the surface of the substrate W. . Further, since copper ions and the like dissolved by electrolysis are immediately captured by the ion exchangers 90 and 92 by an ion exchange reaction, the dissolved copper ions and the like are again deposited on other parts of the substrate W or oxidized. It becomes fine particles and does not contaminate the surface of the substrate W.
[0051]
Instead of pure water or ultrapure water, a liquid having an electric conductivity of 500 μS / cm or less, for example, an electrolytic solution obtained by adding an electrolyte to pure water or ultrapure water may be used. By using the electrolytic solution, electric resistance can be reduced and power consumption can be reduced. Examples of the electrolytic solution include NaCl and Na ₂ SO ₄ Neutral salt such as HCl and H ₂ SO ₄ A solution such as an acid such as ammonia or an alkali such as ammonia can be used, and can be selected and used as appropriate depending on the properties of the workpiece.
[0052]
Furthermore, instead of pure water or ultrapure water, a surfactant or the like is added to pure water or ultrapure water, and the electric conductivity is 500 μS / cm or less, preferably 50 μS / cm or less, more preferably 0. A liquid having a specific resistance of 10 MΩ · cm or less may be used. In this way, by adding a surfactant to pure water or ultrapure water, a layer having a uniform suppressing action for preventing the movement of ions is formed at the interface between the substrate W and the ion exchangers 90 and 92. Therefore, the concentration of ion exchange (dissolution of metal) can be relaxed and the flatness of the work surface can be improved. Here, the surfactant concentration is preferably 100 ppm or less. If the value of electrical conductivity is too high, the current efficiency is lowered and the processing speed is slowed down, but the electrical conductivity is 500 μS / cm or less, preferably 50 μS / cm or less, more preferably 0.1 μS / cm or less. A desired processing speed can be obtained by using a liquid having
[0053]
Moreover, the ion exchangers 90 and 92 of the electrode part 44 can be comprised with the nonwoven fabric which provided the anion exchange ability or the cation exchange ability, for example. The cation exchanger is preferably one that bears a strongly acidic cation exchange group (sulfonic acid group), but may be one that bears a weak acid cation exchange group (carboxyl group). The anion exchanger is preferably one carrying a strong basic anion exchange group (quaternary ammonium group), but may be one carrying a weak basic anion exchange group (tertiary or lower amino group).
[0054]
Here, for example, a nonwoven fabric imparted with a strong base anion exchange ability is a so-called radiation graft polymerization method in which a polyolefin nonwoven fabric having a fiber diameter of 20 to 50 μm and a porosity of about 90% is irradiated with γ rays and then graft polymerization is performed. The graft chain is introduced, and then the introduced graft chain is aminated to introduce a quaternary ammonium group. The capacity of the ion exchange group to be introduced is determined by the amount of graft chains to be introduced. In order to perform the graft polymerization, for example, using monomers such as acrylic acid, styrene, glycidyl methacrylate, sodium styrenesulfonate, chloromethylstyrene, and the like, by controlling the monomer concentration, reaction temperature, and reaction time, The amount of grafting to be polymerized can be controlled. Therefore, the ratio of the weight after graft polymerization to the weight of the material before graft polymerization is called the graft ratio. This graft ratio can be up to 500%, and the ion exchange groups introduced after the graft polymerization are A maximum of 5 meq / g is possible.
[0055]
The non-woven fabric imparted with strong acid cation exchange ability was irradiated with γ rays on a non-woven fabric made of polyolefin having a fiber diameter of 20 to 50 μm and a porosity of about 90%, in the same manner as the method for imparting strong basic anion exchange ability. A graft chain is introduced by a so-called radiation graft polymerization method in which post-graft polymerization is performed, and then the introduced graft chain is treated with, for example, heated sulfuric acid to introduce a sulfonic acid group. Moreover, a phosphoric acid group can be introduce | transduced if it processes with the heated phosphoric acid. Here, the graft ratio can be 500% at the maximum, and the ion exchange group introduced after the graft polymerization can be 5 meq / g at the maximum.
[0056]
Examples of the material of the ion exchangers 90 and 92 include polyolefin polymers such as polyethylene and polypropylene, and other organic polymers. Moreover, as a raw material form, a woven fabric, a sheet | seat, a porous material, a short fiber, etc. other than a nonwoven fabric are mentioned. Here, polyethylene and polypropylene can be subjected to graft polymerization by generating radicals in the material by first irradiating the material with radiation (γ rays and electron beams) (pre-irradiation) and then reacting with the monomer. . Thereby, a graft chain having high uniformity and few impurities can be formed. On the other hand, other organic polymers can be radically polymerized by impregnating the monomer and irradiating (simultaneously irradiating) radiation (γ rays, electron beams, ultraviolet rays). In this case, it is not uniform, but can be applied to most materials.
[0057]
In this way, by configuring the ion exchangers 90 and 92 with a nonwoven fabric provided with anion exchange capacity or cation exchange capacity, liquid such as pure water, ultrapure water, or electrolytic solution can freely move inside the nonwoven fabric. Thus, it becomes possible to easily reach an active site having a water decomposition catalytic action inside the nonwoven fabric, and many water molecules are dissociated into hydrogen ions and hydroxide ions. Furthermore, since the hydroxide ions generated by the dissociation are efficiently transported to the surface of the processing electrode 84 as the liquid such as pure water, ultrapure water, or electrolytic solution moves, a high current can be obtained even at a low applied voltage.
[0058]
Here, if the ion exchangers 90 and 92 are configured only with an anion exchange ability or a cation exchange ability, not only the work material that can be electrolytically processed is limited, but also impurities are likely to be generated depending on the polarity. . Therefore, an anion exchanger having an anion exchange ability and a cation exchange ability having a cation exchange ability are overlapped, or both anion exchange ability and cation exchange ability are given to the ion exchangers 90 and 92 themselves. As a result, the range of the material to be processed can be expanded, and impurities can be hardly generated.
[0059]
In addition, oxidation or elution of the electrode generally causes a problem due to an electrolytic reaction. For this reason, it is preferable to use carbon, a relatively inert noble metal, a conductive oxide, or a conductive ceramic as the electrode material. When the electrode is oxidized, the electrical resistance value of the electrode increases and the applied voltage increases. However, if the electrode surface is protected with a material that is difficult to oxidize such as platinum or a conductive oxide such as iridium, the conductivity due to the oxidation of the electrode material The fall of property can be prevented.
[0060]
FIG. , Other electric It is sectional drawing (FIG. 7 equivalent view) which shows typically the board | substrate holding | maintenance part 42 and the electrode part 44a in a solution processing apparatus. This example Similarly to the above-described example, the electrode portion 44a includes a substantially disc-shaped processing electrode 84 having a diameter larger than the diameter of the substrate W, and a plurality of power supply electrodes 86 arranged on the outer peripheral portion of the processing electrode 84. And an insulator 88 that separates the processing electrode 84 and the power supply electrode 86. But, This example Then, the ion exchanger is not provided on the upper surface of the electrode. Further, a plurality of fluid supply ports 84 a as fluid supply parts for supplying the processing electrode 84 with pure water, more preferably, processing liquid such as ultrapure water or electrolytic solution, are arranged radially with respect to the center of the processing electrode 84. Other configurations are the same as those in the above example.
[0061]
In addition, This example Although the case where the ion exchanger is not placed on the electrode surface is shown, a member other than the ion exchanger may be interposed between the electrode and the workpiece. In that case, ions are moved through the liquid between the electrode and the workpiece by using a liquid-permeable member such as a sponge.
[0062]
When no member is interposed between the electrode and the workpiece, the resistance between the workpiece and each electrode is between the machining electrode 84 and the feeding electrode 86 adjacent to each other with the insulator 88 interposed therebetween. It is necessary to set the distance between the workpiece and each electrode and the distance between the processing electrode 84 and the power supply electrode 86 with the insulator 88 interposed therebetween so as to be smaller than the resistance. Thereby, the movement of ions is performed between the electrode and the workpiece rather than between the adjacent electrodes, and the current flows preferentially from the feeding electrode → the workpiece → the machining electrode.
[0063]
This example When the unnecessary ruthenium film Ru deposited or attached to the surface of the substrate W is removed by etching using the electrolytic processing apparatus, the processing electrode 84 and the power supply electrode 86 and the ruthenium film Ru that is the processed portion of the substrate W are interposed between them. For example, an electrolytic solution containing a halide is supplied. Then, the anode of the power source is connected to the feeding electrode 86 and the cathode is connected to the processing electrode 84, whereby the ruthenium film Ru on the surface of the substrate W is made the anode and the processing electrode 84 is made the cathode, and the substrate W and the processing are processed. The electrolyte solution is supplied between the electrode 84 and the power supply electrode 86 to remove the portion facing the processing electrode 84 by etching.
[0064]
As the solvent for dissolving the halide, for example, water or an organic solvent such as alcohols, acetonitrile, dimethylformamide, dimethyl sulfoxide can be used. What is necessary is just to select suitably by the use of the ruthenium film | membrane to process, the washing | cleaning required after a process, a surface state, etc. In order to avoid contamination of impurities as much as possible, it is preferable to use pure water, and it is more preferable to use ultrapure water for a substrate used for semiconductor manufacturing.
[0065]
In addition, when the halide is used as an electrolytic solution, the etching process of the ruthenium film proceeds by electrochemical interaction, and the compound generated during electrolysis reacts with ruthenium, and the reaction product is contained in the electrolytic solution. Any one may be used as long as it dissolves in water or is volatilized and removed. For example, hydrohalic acid such as an aqueous solution of HCl, HBr, HI, HClO ₃ , HBrO ₃ , HIO ₃ , Aqueous solutions of halogen oxo acids such as HClO, HBrO, HIO, NaClO ₃ , KClO ₃ An aqueous solution of a halogen oxoacid salt such as NaClO or KClO or an aqueous solution of a neutral salt such as NaCl or KCl can be used as the electrolyte. What is necessary is just to select suitably by the use application of the ruthenium after a process, the influence of a residual substance, the film thickness of ruthenium, the characteristic of a ruthenium base film, etc.
[0066]
In this electrolytic processing apparatus, similarly to the above-described example, the electrode portion 44a is scrolled while rotating the substrate W in proximity to or in contact with the processing electrode 84 and the feeding electrode 86 via the substrate holder. As a result, the ruthenium film is etched away by an electrochemical reaction, and the halide generated by electrolysis and the ruthenium react chemically, and the ruthenium film is removed by etching. The processed surface is washed with ultrapure water supplied from an ultrapure water supply nozzle (not shown).
[0067]
The concentration of the halide is 1 mg / l to 10 g / l, preferably about 100 mg / l to 1 g / l. The type of halide, processing time, processing area, distance between the ruthenium film as the anode and the processing electrode as the cathode, the electrolytic voltage, etc. may be appropriately determined according to the surface condition of the substrate after electrolytic processing, the ability of waste liquid treatment, etc. . For example, the amount of chemical solution used can be reduced by increasing the electrolysis voltage using a dilute electrolyte, and the processing speed can be increased by increasing the concentration of the electrolyte.
[0068]
In the above-described embodiment, the electrode unit 4 4 and And although the example using what was provided with the processing electrode 84 comprised by one member was demonstrated, it is not restricted to this. For example, as shown in FIG. 11, the electrode portion 44b may be provided with a processing electrode 184 divided into a plurality of grids. Moreover, as shown in FIG. 12, you may use the thing provided with the process electrode 284 divided | segmented into the ring shape as the electrode part 44c. In these cases, the divided processing electrodes may be configured to be electrically integrated or may be configured to be electrically separated via an insulator. When the machining electrodes are electrically separated, it is not easy to equalize the machining speed of each machining electrode. Therefore, when considering the variation in machining speed between the electrodes, one machining electrode is used. It is preferable to comprise by a member.
[0069]
As described above, the electrode unit 4 including the machining electrode 84 configured by one member. 4 In this case, since the substrate W cannot be processed in the region where the power supply electrode 86 exists, the processing speed of the outer peripheral portion where the power supply electrode 86 is disposed is lower than the other regions. Therefore, the processing speed of the outer peripheral portion of the substrate W can be controlled by adjusting the notch width w and the notch length L (see FIG. 8) of the outer peripheral portion of the processing electrode 84. Here, as shown in FIG. 13, the machining electrode is connected to the portion where the feeding electrode 86 influences the machining speed via the insulator 89, that is, the outer machining electrode 384 a located at the outer peripheral portion where the feeding electrode 86 is disposed. If the electrode portion 44d divided into a portion that does not affect the processing speed, that is, the inner processing electrode 384b located inside the outer processing electrode 384a is used, a uniform processing speed can be realized on the entire surface of the processing electrode. it can. That is, in consideration of the influence due to the presence of the power supply electrode 86, the voltage applied to each machining electrode 384a, 384b by the power source 46 is adjusted, and the machining speed at the outer machining electrode 384a is set to the machining speed at the inner machining electrode 384b. Therefore, a uniform processing speed can be realized on the entire surface of the processing electrode.
[0070]
Further, in the above-described embodiment, the example in which the electrode portion 44 is scrolled and the substrate W is rotated has been described. However, as long as the processing electrode 84 and the substrate W can be moved relative to each other, what is the case? Also good. For example, both the electrode unit 44 and the substrate W may be rotated. In this case, the center of motion of the machining electrode is the center of rotation. In the above-described embodiment, the example in which the substrate holding unit 42 sucks and holds the substrate W downward (face-down) has been described. However, the present invention is not limited to this. For example, the substrate W is held upward (face-up). May be.
[0071]
Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.
[0072]
【The invention's effect】
As described above, according to the present invention, an electrochemical process, for example, in place of CMP, is performed by electrochemical action while preventing physical damage to a workpiece such as a substrate and damaging the properties of the workpiece. As a result, the CMP process itself can be omitted, the load of the CMP process can be reduced, and the deposits attached to the surface of the workpiece such as the substrate can be removed (cleaned). it can. Moreover, the substrate can be processed even using pure water or ultrapure water alone, thereby preventing extra impurities such as electrolyte from adhering to or remaining on the surface of the substrate. Not only can the cleaning process after removal processing be simplified, but also the waste liquid treatment load can be extremely reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of manufacturing a copper wiring board in the order of processes.
FIG. 2 shows that a processing electrode and a feeding electrode are brought close to a substrate (workpiece), and pure water or a liquid having an electric conductivity of 500 μS / cm or less is placed between the processing electrode and the feeding electrode and the substrate (workpiece). It is a figure attached | subjected to description of the principle of the electrolytic processing by this invention when it was made to supply.
FIG. 3 is a diagram for explaining the principle of electrolytic processing according to the present invention when an ion exchanger is attached only to a processing electrode and liquid is supplied between the processing electrode and a substrate (workpiece). It is.
[Fig. 4] Base It is a top view which shows the structure of a plate processing apparatus.
5 is a longitudinal sectional view schematically showing an electrolytic processing apparatus of the substrate processing apparatus shown in FIG.
6 (a) is a plan view showing a rotation prevention mechanism in the electrolytic processing apparatus of FIG. 5, and FIG. 6 (b) is a cross-sectional view taken along line AA of FIG. 6 (a).
7 is a longitudinal sectional view schematically showing a substrate holding part and an electrode part in the electrolytic processing apparatus of FIG. 5. FIG.
8 is a plan view showing a relationship between an electrode portion and a substrate in FIG. 7;
FIG. 9 (a) shows the relationship between the current flowing when electrolytic processing is performed on the surface of a substrate on which a different material is formed, and FIG. 9 (b) shows the same applied voltage and time. It is a graph which shows each relationship.
FIG. 10 other It is a figure which shows typically the board | substrate holding part and electrode in an electrolytic processing apparatus.
FIG. 11 is a plan view showing an electrode portion according to another embodiment of the present invention.
FIG. 12 is a perspective view showing an electrode portion according to another embodiment of the present invention.
FIG. 13 is a plan view showing an electrode portion together with a substrate in another embodiment of the present invention.
[Explanation of symbols]
6 Copper film (conductor film)
7 Seed layer
10 Workpiece
12a, 12b ion exchanger
14 Processing electrode
16 Feeding electrode
17 Power supply
18 Ultrapure water
19 Fluid supply unit
20 water molecules
22 Hydroxide ion
24 Hydrogen ion
26 Reactant
30 Load / Unload Club
32 reversing machine
34 Electrolytic processing equipment
36 Transfer robot
38 Monitor section
40 arms
42 Substrate holder
44, 44a, 44b, 44c, 44d Electrode part
46 Power supply
48 Swing motor
50 Oscillating shaft
52 Ball screw
54 Motor for vertical movement
56 Motor for rotation
60 Hollow motor
62 Spindle
64 Drive end
66 Anti-rotation mechanism
68,70 recess
72,74 bearings
76,78 shaft
80 connecting members
82 Pure water supply pipe
84,184,284,384a, 384b Processing electrode
86 Feeding electrode
88,89 insulator
90,92 ion exchanger

Claims (8)

A substantially disc-shaped processing electrode;
A feeding electrode for feeding a disk-shaped workpiece;
A holding unit that holds the workpiece and contacts or approaches the processing electrode;
An ion exchanger disposed between the workpiece and at least one of the processing electrode or the feeding electrode;
A power source for applying a voltage between the machining electrode and the power supply electrode;
A fluid supply unit that supplies ultrapure water, pure water, or a liquid having an electric conductivity of 500 μS / cm or less between a workpiece on which the ion exchanger is disposed and at least one of a processing electrode or a feeding electrode;
Wherein in a state where the center of movement is located inside the outer diameter of the workpiece machining electrode, Bei example a drive unit for relatively moving the machining electrode and the workpiece held by the holding portion,
The diameter of the machining electrode is larger than the sum of the relative movement distance between the workpiece and the machining electrode and the diameter of the workpiece, and smaller than twice the diameter of the workpiece. Electrolytic processing equipment. A substantially disc-shaped processing electrode;
A plurality of feeding electrodes arranged on the outer periphery of the disk-shaped processing electrode;
A holding unit that holds the workpiece and contacts or approaches the processing electrode;
An ion exchanger disposed between the workpiece and at least one of the processing electrode or the feeding electrode;
A power source for applying a voltage between the machining electrode and the power supply electrode;
A fluid supply unit that supplies ultrapure water, pure water, or a liquid having an electric conductivity of 500 μS / cm or less between a workpiece on which the ion exchanger is disposed and at least one of a processing electrode or a feeding electrode;
As at least one feeding electrode always supplies power to the workpiece, Bei example and a driving unit for relatively moving the said machining electrode and the workpiece held by the holding portion,
The diameter of the machining electrode is larger than the sum of the relative movement distance between the workpiece and the machining electrode and the diameter of the workpiece, and smaller than twice the diameter of the workpiece. Electrolytic processing equipment. The processing electrode is electrolyte according to claim 2, wherein the feeding electrode is provided with an outer working electrode positioned on the outer peripheral portion arranged, and an inner working electrode located inside of the outer working electrode Processing equipment. The electrolytic processing apparatus according to claim 3 , wherein the power source controls a voltage or a current applied to the outer processing electrode and the inner processing electrode, respectively. The electrolytic processing apparatus according to claim 1, wherein the driving unit causes the machining electrode to scroll or rotate. A machining electrode having a substantially disc shape and having a diameter that is greater than the sum of the relative movement distance between the workpiece and the machining electrode described below and the workpiece diameter, and less than twice the diameter of the workpiece; A power supply electrode for supplying power to a disk-shaped workpiece;
An ion exchanger is disposed between the workpiece and at least one of the processing electrode or the feeding electrode,
A voltage is applied between the machining electrode and the feeding electrode,
Bringing the workpiece into contact with or close to the machining electrode;
Supplying ultrapure water, pure water, or a liquid having an electric conductivity of 500 μS / cm or less between a workpiece on which the ion exchanger is disposed and at least one of a processing electrode or a feeding electrode;
The surface of the workpiece is machined by relatively moving the workpiece and the machining electrode in a state where the center of motion of the machining electrode is always located inside the outer diameter of the workpiece. Electrolytic processing method. A machining electrode having a substantially disk shape and having a diameter larger than the sum of the relative movement distance between the workpiece and the machining electrode described below and the workpiece diameter and less than twice the diameter of the workpiece. A plurality of feeding electrodes are arranged on the outer periphery,
An ion exchanger is disposed between the disk-shaped workpiece and at least one of the processing electrode or the feeding electrode,
A voltage is applied between the machining electrode and the feeding electrode,
Bringing the workpiece into contact with or close to the machining electrode;
Supplying ultrapure water, pure water, or a liquid having an electric conductivity of 500 μS / cm or less between a workpiece on which the ion exchanger is disposed and at least one of a processing electrode or a feeding electrode;
An electrolytic machining method characterized by machining the surface of the workpiece by relatively moving the workpiece and the machining electrode so that at least one feeding electrode always feeds power to the workpiece. 8. The electrolytic machining method according to claim 6, wherein the workpiece and the machining electrode are moved relative to each other by scrolling or rotating the machining electrode.

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