JP2005199401A - Electrochemical machining device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform electrochemical machining efficiently by improving the dissociative reaction of water effectively, and to eliminate the need for replacing work of ion exchangers. <P>SOLUTION: This electrochemical machining device comprises a machining electrode 44 movable closely to a workpiece W, a feeding electrode 46 feeding power to the workpiece W, a liquid feed part 82 feeding liquid 22 including an ion exchange substance 20 with a size smaller than a distance between the workpiece W and at least one of the machining electrode 44 and the feeding electrode 46 to the distance between them, a power source 50 applying a voltage between the machining electrode 44 and the feeding electrode 46, and driving mechanisms 59, 60 generating relative movement between the workpiece W and at least one of the machining electrode 44 and the feeding electrode 46. The workpiece W is moved closely to the machining electrode 44 until the distance to the machining electrode 44 becomes 10 μm and below in a non-contact condition, and subjected to the electrochemical machining. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrolytic processing apparatus and method, and more particularly to an electrolytic process used to process a conductive material formed on the surface of a substrate such as a semiconductor wafer or to remove impurities attached to the surface of the substrate. The present invention relates to a processing apparatus and method.

  In recent years, as a wiring material for forming a circuit on a substrate such as a semiconductor wafer, the movement of using copper (Cu) having low electrical resistivity and high electromigration resistance instead of aluminum or aluminum alloy 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. Methods for forming this copper wiring include chemical vapor deposition (CVD), sputtering, and plating, but in any case, copper is deposited on almost the entire surface of the substrate, and chemical mechanical polishing is performed. Unnecessary copper is removed by (CMP).

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, an insulating film 2 such as an oxide film made of SiO ₂ or a low-k material film is deposited on a conductive layer 1a on a semiconductor substrate 1 on which a semiconductor element is formed. A contact hole 3 and a wiring groove (trench) 4 are formed by an etching technique. A barrier layer 5 made of TaN or the like is formed thereon, and a seed layer 7 as a power feeding layer for electrolytic plating is formed thereon by sputtering or CVD.

  Then, by plating the surface of the substrate W with copper, the contact hole 3 and the wiring groove 4 of the semiconductor substrate 1 are filled with copper as shown in FIG. A film 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 surface of the insulating film 2 Are almost coplanar. As a result, a wiring made of the copper film 6 is formed as shown in FIG.

  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.

  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.

In the above-described electrolytic processing and electrolytic polishing, the processing proceeds by electrochemical interaction between the workpiece and an electrolytic solution (aqueous solution of NaCl, NaNO ₃ , HF, HCl, HNO ₃ , NaOH, or the like). Therefore, as long as an electrolytic solution containing such an electrolyte is used, it is inevitable that the workpiece is contaminated with the electrolytic solution.
In addition, a process of cutting by 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.

  For this reason, recently, methods for electrolytic processing of metals have been developed that improve the environmental load, contamination of processed products, danger during work, and the like (see Patent Document 1, Patent Document 2, etc.). These electrolytic processing methods are methods of performing electrolytic processing using pure water or ultrapure water. Since pure water or ultrapure water hardly conducts electricity, in this electrolytic processing method, an electrolytic process is performed on the workpiece by placing an ion exchanger between the workpiece and the processing electrode. Since the workpiece, the ion exchanger, and the machining electrode are all placed under pure water or ultrapure water, the problem of environmental burden and the problem of contamination of the workpiece are remarkably improved. Moreover, the metal which is a workpiece is removed as a metal ion by electrolytic reaction, and is hold | maintained at an ion exchanger. Thus, since the removed metal ions are held in the ion exchanger, contamination of the workpiece and the liquid (pure water or ultrapure water) itself can be further reduced, and the above method is an ideal electrolytic machining. It is considered as a method.

  As described above, according to the electrolytic processing method of processing a workpiece while supplying ultrapure water in a state where an ion exchanger is arranged, contamination of the workpiece can be prevented and the environmental load can be significantly reduced. it can. Further, according to the above-described electrolytic processing method, the surface of various metal parts can be given a specular gloss, and further, a slurry containing a cutting oil, an abrasive, and an electrolytic solution required for a conventional metal machining finishing method. Etc. can be made unnecessary.

Further, in electrolytic processing (etching) using an electrolytic solution, the surface of the workpiece after processing is flattened by performing etching while keeping the distance between the workpiece and the counter electrode at 10 μm or less, for example, 1 μm. The distance between the platen electrode and the surface of the wafer (substrate) is 1 mm or less, preferably 2000 mm, and a polishing pad (see FIG. A wafer having a thickness of about 200 mm while being in contact with the wafer surface to polish the wafer surface (see Patent Document 4, etc.) has been proposed.
JP 2000-52235 A JP 2001-64799 A JP 2001-102356 A WO 02/064314 A1

In electrolytic processing using an ion exchanger, the ion exchanger is fixed and disposed at least one between a workpiece and a processing electrode or a feeding electrode, thereby promoting the dissociation reaction of water and the generated OH ^- so that for machining is supplied to the surface of the workpiece ions and H ⁺ ions. However, since the water permeability of the ion exchanger itself varies depending on the form of the ion exchanger, for example, when an ion exchanger having poor water permeability is used, the workpiece and the electrode (working electrode or feeding electrode) The supply of water between is limited. For this reason, the supply of water to the ion exchanger is insufficient, and the decomposition efficiency of water, and hence the supply amount of OH ⁻ ions and H ⁺ ions, which are reactive species, is reduced. In some cases, the removal efficiency of processing products and gas generated in the process decreases, and the shape of the processed surface deteriorates.

In addition, processing products that affect the processing characteristics are gradually accumulated inside the ion exchanger as processing proceeds. To solve this problem, there is a method of electrically removing processed products accumulated in the ion exchanger, but no constant solution has been reached. For this reason, finally, it is necessary to replace the ion exchanger, and the apparatus must be stopped while the ion exchanger is replaced, leading to a decrease in throughput.
For this reason, (1) increase of water supply flow rate to the ion exchanger, (2) high efficiency removal of processing products and gas generated during processing, and (3) simplicity of ion exchanger replacement are required. There is a desire to develop a full electrolytic processing apparatus and method.

  In addition, an unnecessary portion of the conductive film having an uneven surface formed on the surface of a substrate such as a semiconductor wafer, for example, a copper film 6 embedded in a trench or the like shown in FIG. When removing by the conventional electrolytic processing, a typical problem is that it is difficult to flatten the unevenness on the surface of the conductive film. This is because the unevenness of the surface of the conductive film is on the order of submicron, whereas the distance between the workpiece and the electrode is large, and the electric resistivity of the electrolyte is generally small, This is because a desired processing speed difference cannot be obtained between the concave and convex portions.

  The present invention has been made in view of the above circumstances, and can efficiently improve the dissociation reaction of water, efficiently perform electrolytic processing, and eliminate the need for work such as replacement of an ion exchanger. It is an object of the present invention to provide an electrolytic processing apparatus and method capable of performing the above.

  According to a first aspect of the present invention, there is provided a machining electrode that is freely accessible to a workpiece, a feeding electrode that feeds power to the workpiece, and at least one of the workpiece and the machining electrode or the feeding electrode. A liquid supply unit for supplying a liquid containing an ion exchange material having a size smaller than the distance between them, a power source for applying a voltage between the processing electrode and the feeding electrode, and the workpiece A drive mechanism for causing relative movement between at least one of the machining electrode and the feeding electrode, and the workpiece to the machining electrode until contact with the machining electrode is 10 μm or less without contact. An electrolytic processing apparatus that performs electrolytic processing in proximity.

  FIG. 2 shows the processing principle of the present invention. In FIG. 2, the workpiece 10 and the machining electrode 12 are arranged close to each other, and a voltage is applied between the workpiece 10 and the machining electrode 12 via the power supply 14 while the substrate 16 The state where the liquid 22 containing the ion exchange material 20 provided with the ion exchange group 18 on the surface is supplied is shown. In this example, an example in which the ion exchange group 18 is provided on the surface of the base material 16 is shown, but it is needless to say that an ion exchange group may be provided inside the base material.

Thereby, water molecules H ₂ O in the liquid 22 such as ultrapure water are dissociated into hydroxide ions OH ⁻ and hydrogen ions H ⁺ by the ion exchange groups 18 of the ion exchange material 20, for example, generated hydroxides. Ion OH ⁻ is supplied to the surface of the workpiece 10 facing the machining electrode 12 by the electric field between the workpiece 10 and the machining electrode 12 and the flow of the liquid 22 such as ultrapure water. The density of the hydroxide ions OH ^{− in} the vicinity of the workpiece 10 is increased, and the atoms of the workpiece 10 and the hydroxide ions OH ⁻ are reacted. The reaction product generated by the reaction is dissolved in the liquid 22 or taken into the ion exchange group 18 of the ion exchange material 20 and is covered by the flow of the liquid 22 such as ultrapure water along the surface of the workpiece 10. It is removed from the workpiece 10. Thereby, the removal process of the surface layer of the to-be-processed object 10 is performed.

  As described above, this processing method purely removes the workpiece only by electrochemical interaction with the workpiece, and the physical process between the polishing member such as CMP and the workpiece is performed. The processing principle is different from processing by mixing interaction and chemical interaction with chemical species in the polishing liquid. Therefore, removal processing can be performed without impairing the characteristics of the material. For example, even low-k materials having low mechanical strength can be removed without physical interaction. is there. In addition, even when compared with a normal electrolytic processing apparatus, contamination on the surface of the workpiece is greatly reduced by using a liquid of 500 μS / cm or less, preferably pure water, more preferably ultrapure water as the electrolytic solution. In addition, the waste liquid after processing can be easily treated.

According to the present invention, a large amount of water is present around the ion exchange material by supplying a liquid containing the ion exchange material between the workpiece and the machining electrode and / or the feeding electrode and performing the electrolytic machining. Thus, the efficiency of the water dissociation reaction can be increased, and a large amount of liquid can be supplied between the workpiece and the processing electrode and / or the power feeding electrode to efficiently perform the electrolytic processing.
Further, a conductive film formed on the surface of a substrate such as a conductor wafer by performing electrolytic processing by bringing a workpiece close to the processing electrode until the distance to the processing electrode becomes 10 μm or less without contact, for example, By increasing the ratio of the distance between the convex tip of the conductive film surface and the processing electrode to the uneven step (for example, 200 nm) on the surface, the convex tip of the conductive film surface is preferentially processed to further increase the conductive film surface. It can be flattened. The distance between the workpiece and the processing electrode is as narrow as possible without being in contact with each other. For example, it is preferable that the distance between the workpiece and the processing electrode is on the order of several μm to several hundred nm in order to eliminate the step on the surface of the conductive film.

The invention according to claim 2 is the electrolytic processing apparatus according to claim 1, wherein the ion exchange material is contained in the liquid in an amount of 1 to 90% by weight.
The ion exchange material is present in the liquid in the form of particles or gel, and is generally contained in the liquid in a proportion of 1 to 90% by weight, but in the liquid in a proportion of 1 to 50% by weight. It is preferably included. When the amount of the ion exchange material is large, ion separation occurs, the generation rate of OH ⁻ increases, the current density between the processing electrode and the workpiece increases, and the processing speed proportional to the current density increases. However, if the amount of ion exchange material is too large relative to the amount of water, there will be insufficient water to be subjected to ion exchange, and the generation of OH ⁻ will not increase to some extent, and the current density may decrease. is there. Therefore, the ratio of the ion exchange material in the liquid is generally 1 to 90% by weight, and preferably 1 to 50% by weight.

According to a third aspect of the present invention, the ion exchange material is of a size that can smoothly pass through a gap between the workpiece and the processing electrode. It is a processing device.
As a result, the ion-exchange material may not enter between the workpiece and the processing electrode and / or the feeding electrode, and even if it is included, the surface of the workpiece may be damaged by entering it forcibly. Can be prevented. For example, the size (diameter) of the granular ion exchange material is smaller than this when, for example, the distance between the workpiece and the processing electrode is on the order of several μm to several hundred nm, and preferably, the workpiece and the processing electrode 1/10 or less of the distance.

  The invention according to claim 4 is characterized in that the liquid is any one of ultrapure water, pure water, a liquid having an electric conductivity of 500 μS / cm or less, or an electrolytic solution. An electrolytic processing apparatus according to claim 1.

  Ultrapure water is, for example, water having an electric conductivity (1 atm, converted at 25 ° C., the same shall apply hereinafter) of 0.1 μS / cm or less, and pure water is water having an electric conductivity of 10 μS / cm or less. Thus, by performing electrolytic processing using ultrapure water or pure water, it is possible to perform clean processing without leaving impurities on the processed surface, thereby simplifying the cleaning process after electrolytic processing. be able to. Specifically, the cleaning step after the electrolytic processing may be one step or two steps. Moreover, for example, the electrical resistance between the bottom of the recess and the processing electrode at the uneven step on the surface of the conductive film formed on the surface of the substrate such as a semiconductor wafer is larger than the electrical resistance between the tip of the convex and the processing electrode. Thus, the planarization characteristics of the conductive film surface can be improved.

  Further, for example, an additive such as a surfactant is added to pure water or ultrapure water, and the electric conductivity is 500 μS / cm or less, preferably 50 μS / cm, more preferably 0.1 μS / cm (ratio). A liquid having a resistance of 10 MΩ · cm or less) may be used, and for this reason, for example, the gap between the bottom of the recess and the processed electrode in the uneven step on the surface of the conductive film formed on the surface of the substrate such as a conductor wafer may be used. The electric resistance can be made larger than the electric resistance between the tip of the convex portion and the processing electrode, and the planarization characteristics of the surface of the conductive film can be improved.

This additive serves to prevent local concentration of ions (eg hydroxide ions (OH ⁻ ions)). In other words, one of the important factors for creating a flat surface is that the removal processing speed is uniform at each point on the entire processing surface, and a single electrochemical removal reaction occurs. Below, the cause of the difference in local removal processing speed is considered to be the concentration of local reactive species, and the cause of the concentration is mainly the deviation of electric field strength between the processing electrode and the feeding electrode. And the distribution of ions in the vicinity of the workpiece surface can be considered. Therefore, local concentration of ions can be suppressed by adding an additive that serves to prevent local concentration of ions (for example, hydroxide ions) into the liquid.

As the electrolytic solution, for example, a neutral salt such as NaCl or Na ₂ SO ₄ , an acid such as HCl or H ₂ SO ₄ , and an alkali such as ammonia can be used. Can be used.

The invention according to claim 5 further includes a regeneration unit that removes the processed product taken into the ion exchange material during processing from the ion exchange material. It is an electrolytic processing apparatus as described in above.
In this way, in the case of an electrolytic processing apparatus using, for example, an ion exchanger fixed, the processing product taken into the ion exchange material contained in the liquid is removed from the ion exchange material and regenerated. Such an exchange operation of the ion exchanger can be made unnecessary.

The invention according to claim 6 is configured such that the regeneration unit separates the ion exchange material from the liquid and disperses the ion exchange material in the regeneration solution to remove a processed product taken into the ion exchange material. 6. The electrolytic processing apparatus according to claim 5, wherein the electrolytic processing apparatus is provided.
According to a seventh aspect of the present invention, the regeneration unit receives the liquid containing the ion exchange material in a regeneration tank, and applies the electric field to the liquid in the regeneration tank to be taken into the ion exchange material. The electrolytic processing apparatus according to claim 5, wherein the electrolytic processing apparatus is configured to remove a processed product.

  According to an eighth aspect of the present invention, the workpiece to be fed by the feeding electrode and the machining electrode are arranged in a non-contact manner and close to each other until the distance between them is 10 μm or less. A liquid containing an ion exchange material having a size smaller than the distance between the electrode and at least one of the feeding electrodes is supplied, and a voltage is applied between the processing electrode and the feeding electrode. The electrolytic processing method is characterized in that the workpiece and at least one of the processing electrode and the feeding electrode are moved relative to each other.

The invention according to claim 9 is the electrolytic processing method according to claim 8, wherein the ion exchange material is contained in the liquid in an amount of 1 to 90% by weight.
The invention according to claim 10 is the electrolytic processing method according to claim 8 or 9, wherein a processed product taken into the ion exchange material during processing is removed from the ion exchange material.

The invention according to claim 11 is characterized in that the ion exchange material is separated from the liquid and dispersed in a regenerating solution to remove a processed product taken into the ion exchange material. This is an electrolytic processing method.
The invention according to claim 12 is the electrolytic processing according to claim 10, wherein an electric field is applied to the liquid containing the ion exchange material to remove the processed product taken into the ion exchange material. Is the method.

  According to the present invention, a large amount of water is present around the ion exchange material by supplying a liquid containing the ion exchange material between the workpiece and the machining electrode and / or the feeding electrode and performing the electrolytic machining. Thus, the efficiency of the water dissociation reaction is improved, and the liquid is supplied between the workpiece and the processing electrode and / or the electrode so that the flow rate of the liquid does not depend on the water permeability of the ion exchange material itself. The liquid flow rate can be easily increased, and thus the electrolytic processing can be performed efficiently. Furthermore, by providing a mechanism for removing processed products taken into the ion-exchange material during processing from the ion-exchange material, the ion exchange material is always freshly exchanged between the workpiece and the processing electrode and / or the feeding electrode. It is possible to supply a liquid containing a substance and eliminate the need for work such as replacement of an ion exchanger. Furthermore, even when a conductive film formed on the surface of a substrate such as a semiconductor wafer is processed, good planarization characteristics can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, a substrate is used as a workpiece, and an example in which a thin film such as a copper film formed on the surface of the substrate is removed is shown. However, the present invention can be applied to other than the substrate. Of course.

  FIG. 3 is a plan view showing a configuration of a substrate processing apparatus including the electrolytic processing apparatus according to the embodiment of the present invention. As shown in FIG. 3, this substrate processing apparatus carries out, for example, a carry-in / out of a cassette containing a substrate W having a copper film 6 as a conductive film and a barrier layer 5 on its surface, as shown in FIG. The pair of load / unload units 30 as the entrance, the first cleaning device 31a that performs the primary cleaning of the substrate, the second cleaning device 31b that performs the secondary cleaning (finish cleaning) of the substrate, and the substrate W are reversed. A reversing machine 32 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 transfers is arranged in parallel with these devices. In addition, when electrolytic processing is performed by the electrolytic processing apparatus 34, a monitor unit 38 that monitors a voltage applied between the processing electrode 44 and the power supply electrode 46 or a current flowing between them as described below is loaded / unloaded. It is arranged adjacent to the part 30.

  FIG. 4 is a longitudinal sectional view of the electrolytic processing apparatus 34 in the substrate processing apparatus, and FIG. 5 is a plan view of the electrode portion of the electrolytic processing apparatus 34. As shown in FIGS. 4 and 5, the electrolytic processing apparatus 34 is vertically suspended at the free end of the swing arm 40 that can move up and down and swing in the horizontal direction, and holds and holds the substrate W downward (face-down). The substrate holding part 42 and the electrode part 48 which consists of a disk-shaped insulator and fan-shaped processing electrode 44 and the electric power feeding electrode 46 were alternately embedded by exposing the surface inside. The machining electrode 44 is connected to the cathode of the power supply 50, and the power supply electrode 46 is connected to the anode of the power supply 50. In this embodiment, the size of the electrode portion 48 is set to be slightly larger than the outer diameter of the substrate W held by the substrate holding portion 42.

  The swing arm 40 is moved up and down via a ball screw 54 as the vertical motion motor 52 is driven, and is connected to the upper end of a swing shaft 58 that rotates as the swing motor 56 rotates. The substrate holding part 42 is connected to a rotation motor 59 attached to the free end of the swing arm 40, and rotates (autorotates) as the rotation motor 59 is driven.

  A hollow motor 60 is installed below the electrode portion 48, and a driving end 64 is provided on the main shaft 62 of the hollow motor 60 at a position eccentric from the center of the main shaft 62. The electrode portion 48 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 48 and the hollow motor 60.

  FIG. 6A is a plan view showing a rotation prevention mechanism in this 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 48 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 48. Bearings 72 and 74 are mounted at the locations 68 and 70, respectively. One end portions of two shaft bodies 76 and 78 that are 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 48 has a so-called scroll motion (translational rotation) that does not rotate with a radius “e” between the center of the main shaft 62 and the drive end 64 as a radius. Exercise).

  Returning to FIG. 4, the liquid 22 containing the ion exchange material 20 between the electrode portion 48 and the substrate W held by the substrate holding portion 42 is located above the electrode portion 48 (see FIG. 2, the same applies hereinafter). A liquid supply nozzle 82 as a liquid supply unit for supplying the liquid is disposed. A liquid recovery tank 84 that recovers the liquid 22 supplied between the electrode unit 48 and the substrate W held by the substrate holding unit 42 is provided on the outer periphery of the electrode unit 48.

  The above-described ion exchange material 20 (see FIG. 2) is configured by adding an ion exchange group (anion exchange group or cation exchange group) 18 to the surface of the base material 16. The cation exchange group is preferably a strong acid cation exchange group (sulfonic acid group), but may be a weak acid cation exchange group (carboxyl group). The anion exchange group is preferably a strong basic anion exchange group (quaternary ammonium group), but may be a weak basic anion exchange group (tertiary or lower amino group).

  Here, for example, an ion exchange material 20 provided with an ion exchange group 18 composed of a strongly basic anion exchange group introduces a graft chain by a so-called radiation graft polymerization method in which graft polymerization is performed after irradiating the substrate 16 with γ rays. Then, the introduced graft chain is aminated to introduce a quaternary ammonium group. The capacity of the ion exchange group 18 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 the graft polymerization to the weight of the material before the graft polymerization is called the graft ratio, and this graft ratio can be 500% at the maximum, and the ion exchange groups 18 introduced after the graft polymerization are 18%. Can be up to 5 meq / g.

  The ion exchange material 20 provided with the ion exchange group 18 composed of a strongly acidic cation exchange group is subjected to graft polymerization after irradiating the substrate 16 with γ-rays in the same manner as the method for providing the strongly basic anion exchange group. A graft chain is introduced by a so-called radiation graft polymerization method, 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 18 introduced after the graft polymerization can be 5 meq / g at the maximum.

The base material 16 of the ion exchange material 20 may be either an organic material or an inorganic material. Examples of the organic material include hydrocarbon resins such as polystyrene-divinylbenzene copolymer and fluorine resins. As the inorganic substance, for example, inert metal such as platinum or gold, a non-conductive oxide or a conductive oxide such as SiO ₂ and the like. The form of the ion exchange material 20 may be in the form of particles or some gel, and is generally contained in the liquid 22 in an amount of 1 to 90% by weight, preferably 1 to 50% by weight. Here, the liquid 22 containing the ion exchange material 20 needs to have sufficient fluidity so as to easily enter the gap between the lowered substrate W and the electrode portion 48 as described below. . For this reason, when the ion exchange material 20 is in some gel form and its viscosity is small, it may be used as it is.

  Here, when polyethylene or polypropylene is used as the base material 16, the base material 16 is first irradiated with radiation (γ rays and electron beams) (pre-irradiation) to generate radicals on the base material 16, and then Can be grafted by reacting with a monomer. Thereby, a graft chain having high uniformity and few impurities can be formed. On the other hand, when other organic polymer is used as the substrate 16, radical polymerization can be performed by impregnating the monomer and irradiating (simultaneously irradiating) radiation (γ rays, electron beams, ultraviolet rays). In this case, although it lacks uniformity, it can be applied to most substrates.

  In this way, by supplying the liquid 22 containing the ion exchange material 20 provided with the ion exchange group 18 between the substrate W and the electrode portion 48, a large amount of water is present around the ion exchange material 20 and water is added. The efficiency of the dissociation reaction can be increased, whereby 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 44 as the liquid 22 such as pure water or ultrapure water or an electrolytic solution moves, a high current can be obtained even at a low applied voltage. In addition, by supplying a large amount of the liquid 22 between the substrate W and the processing electrode 44 and the power supply electrode 46, the electrolytic processing can be performed efficiently.

  Here, when only the ion exchange material 20 to which one of the anion exchange group or the cation exchange group is added is used, not only the work material that can be electrolytically processed but also the impurities depending on the polarity. It becomes easy to generate. Therefore, an ion exchange material (anion exchange material) 20 using an anion exchange group as the ion exchange group 18 and an ion exchange material (cation exchange material) 20 using a cation exchange group as the ion exchange group 18 are contained in the liquid 22. The ion-exchange substance 20 using both a cation exchange group and an anion exchange group may be used as the ion exchange group 18, thereby expanding the range of the material to be processed and introducing impurities. It can be made difficult to generate.

  In this embodiment, for example, when processing copper, an electrolytic processing action occurs on the cathode side, so that the electrode connected to the cathode of the power supply 50 becomes the processing electrode 44 and the electrode connected to the anode of the power supply 50 feeds power. As the electrode 46, the processing electrode 44 and the feeding electrode 46 are alternately arranged along the circumferential direction. Depending on the processing material, the electrode connected to the cathode of the power supply 50 may be used as a feeding electrode, and the electrode connected to the anode may be used as a processing 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 50 becomes the processing electrode 44, and the electrode connected to the anode is the feeding electrode. 46. 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 50 becomes the processing electrode, and the electrode connected to the cathode becomes the power supply electrode.

  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. 4, the electrode connected to the anode of the power supply 50 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 when the conductive oxide is reduced. Also, the conductive oxide can be removed by using the workpiece as a cathode and facing the anode electrode.

  The above example shows an example in which the copper film 6 as the conductive film formed on the surface of the substrate is subjected to electrolytic processing, but unnecessary ruthenium (Ru) deposited or attached 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.

  In this way, by providing the processing electrodes 44 and the power supply electrodes 46 alternately along the circumferential direction, it is not necessary to provide a power supply unit that supplies power to the conductive film (workpiece) of the substrate W. The entire surface can be processed. Further, as a method for applying voltage and current, in addition to DC input, rectangular wave, pulse, or sine wave input may be used. In the case of rectangular wave input, the voltage and current inputs are rectangular waves of positive and negative and positive and zero, and the duty ratio is arbitrarily set depending on the object to be processed.

  Here, the processing electrode 44 and the power supply electrode 46 generally have a problem of oxidation or elution due to an electrolytic reaction. For this reason, it is preferable to use carbon, a comparatively inactive noble metal, a conductive oxide, or a conductive ceramic rather than the metal and metal compound currently widely used for the electrode as a raw material of an electrode. As an electrode made of this noble metal, for example, titanium is used as the base electrode material, platinum or iridium is attached to the surface by plating or coating, and sintering is performed at a high temperature to maintain stability and strength. Can be mentioned. Ceramic products are generally obtained by heat treatment using inorganic materials as raw materials, and products having various characteristics are made using various nonmetals, metal oxides, carbides and nitrides as raw materials. Some of these are conductive ceramics. When the electrode is oxidized, the electrical resistance value of the electrode increases, leading to an increase in applied voltage. Thus, by protecting the electrode surface with a material that is difficult to oxidize such as platinum or a conductive oxide such as iridium, the electrode is protected. A decrease in conductivity due to oxidation of the material can be prevented.

  As the liquid 22 containing the ion exchange material 20, pure water, preferably ultrapure water is used. Here, the pure water is, for example, water having an electric conductivity of 10 μS / cm or less, and the 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. . Furthermore, since the copper ions and the like dissolved by electrolysis are immediately captured by the ion exchange group 18 of the ion exchange material 20 by the ion exchange reaction, the dissolved copper ions and the like are again deposited on other portions of the substrate W, The surface of the substrate W is not contaminated by being oxidized into fine particles.

Instead of pure water or ultrapure water, a liquid having an electric conductivity of 500 μS / cm or less, or an arbitrary electrolytic solution, 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. As this electrolytic solution, for example, a neutral salt such as NaCl or Na ₂ SO ₄ , an acid such as HCl or H ₂ SO ₄ , or an alkali such as ammonia can be used. Depending on the characteristics, it can be appropriately selected and used.

  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 inhibitory action to prevent ion migration is formed on the surface of the substrate W, whereby ion exchange (metal The concentration of the dissolution 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 the electrical conductivity is too high, the current efficiency is lowered and the processing speed is slowed down. However, 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

  Next, substrate processing (electrolytic processing) using this substrate processing apparatus 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 conductive film (processed part) 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.

  The transfer robot 36 receives the inverted substrate W, transfers it to the electrolytic processing apparatus 34, holds it by suction by the substrate holder 42, and moves the swing arm 40 in this state to hold the substrate W. The holding part 42 is moved to a machining position directly above the electrode part 48. Next, the vertical movement motor 52 is driven to lower the substrate holding portion 42, and the substrate W held by the substrate holding portion 42 is brought close to the surface of the electrode portion 48, that is, the surfaces of the processing electrode 44 and the feeding electrode 46. In this state, the rotation motor 59 is driven to rotate the substrate W, and at the same time, the hollow motor 60 is driven to cause the electrode portion 48 to scroll, whereby the substrate W held by the substrate holding portion 42 and the processing electrode 44 and The feeding electrode 46 is moved relative to each other. At this time, the liquid 22 containing the ion exchange material 20 is supplied from the liquid supply nozzle 82 between the substrate W and the electrode portion 48, and the space between the substrate W and the electrode portion 48 is filled with the liquid 22. The liquid 22 that has flowed is recovered in the liquid recovery tank 84.

  Then, a predetermined voltage is applied between the processing electrode 44 and the power supply electrode 46 by the power source 50, and the processing electrode (cathode) is generated by hydrogen ions or hydroxide ions generated by the ion exchange groups 18 of the ion exchange material 20. In 44, electrolytic processing of the conductive film (copper film 6) on the surface of the substrate W is performed. In this embodiment, the substrate holding portion 42 is rotated and the electrode portion 48 is simultaneously scrolled to move the substrate W, the processing electrode 44 and the feeding electrode 46 relative to each other for processing. The relative motion between the substrate W and the electrode unit 48 is not limited to this, and at least one of the substrate W and the electrode unit 48 may rotate, eccentrically rotate, translate, reciprocate, or scroll.

  Here, as shown in FIG. 7, the substrate W held by the substrate holder 42 is processed as much as possible until the distance D from the processing electrode 44 is 10 μm or less, preferably several μm to several hundreds nm. It is preferable to perform electrolytic processing in a state where the electrode 44 is not in contact with the electrode 44 in order to eliminate a step on the surface of the conductive film such as the copper film 6 (see FIG. 1) on the surface of the substrate W. That is, for example, the surface of the copper film 6 as the conductive film formed on the surface of the substrate W such as a semiconductor wafer shown in FIG. There is T. For this reason, for example, when the distance D between the surface of the copper film 6 and the processing electrode 44 is, for example, about 1 mm (<< T = 200 nm), the ratio of the distance D to the uneven step T becomes extremely small, and the electric resistance is Since it is proportional to the distance, it is difficult to preferentially remove only the convex portions of the copper film 6. However, when the distance D between the surface of the copper film 6 and the processing electrode 44 is, for example, 1 μm, the ratio of the distance D to the uneven step T is high. For this reason, as shown in FIG. By reducing the distance D between the surface and the processing electrode 44, the tip of the convex portion of the copper film 6 is preferentially processed, and the residual step is further reduced as the processing amount increases. The surface can be processed more flatly.

Further, by using pure water having a high electrical resistivity, ultrapure water, or a liquid having an electric conductivity of 500 μS / cm or less as the liquid 22, the bottom of the concave portion and the processing electrode 44 at the concave and convex step T on the surface of the copper film 6. the electrical resistance R ₁ between, larger than compared with the electric resistance R ₂ between the projection end and the working electrode 44 (R _{1> R 2),} between the projection end and the recess bottom of the step height T It is possible to improve the planarization characteristics of the surface of the copper film 6 by causing a difference in processing speed.

  The size (diameter) d of the ion exchange material 20 contained in the liquid 22 is smaller than the distance D (d <D) between the surface of the copper film 6 and the processing electrode 44 (and the feeding electrode 46), and the substrate W and the processing are processed. It is preferable that the size is such that the gap between the electrode 44 and the electrode 44 can pass smoothly. As a result, even if the ion exchange material 20 does not enter between the substrate W (copper film 6) and the processing electrode 44, or even if it enters, the surface of the copper film 6 is damaged by entering it forcibly. This can be prevented. The size (diameter) d of the ion exchange material 20 is smaller than, for example, the distance between the substrate W and the processing electrode 44 when the distance between the substrate W and the processing electrode 44 is on the order of several μm to several hundred nm. 1/10 or less.

  At this time, the voltage applied between the machining electrode 44 and the feeding electrode 46 or the current flowing between them is monitored by the monitor unit 38 to detect the end point (machining end point). That is, if 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. 9A, when the current flowing when electrolytic processing is performed on the surface of the substrate W on which the material B and the material A are sequentially formed is monitored, the material A is electrolytically processed. A constant current flows while the material B is in operation, but the current that flows at the time of transition to processing of a different material B changes. Similarly, even when the voltage is applied between the machining electrode 44 and the feeding electrode 46, as shown in FIG. 9B, a constant voltage is applied during the electrolytic machining of the material A. However, 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. The example shows the case where the voltage is higher than when the material A is electrolytically processed. Thus, the end point can be reliably detected by monitoring the change in the current or voltage.

  In this example, the voltage applied between the machining electrode 44 and the feeding electrode 46 by the monitor unit 38 or the current flowing therebetween is monitored to detect the machining end point. The monitor unit 38 may monitor a change in the state of the substrate being processed 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 corresponding to the processing amount reaches an amount corresponding to a 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.

  After completion of the electrolytic processing, the power supply 50 is disconnected from the processing electrode 44 and the power supply electrode 46, the rotation of the substrate holding portion 42 and the electrode portion 48 is stopped, and then the substrate holding portion 42 is raised to move the swing arm 40. To move the substrate W to the transfer robot 36. The transport robot 36 that has received the substrate W transports it to the reversing machine 32 and reverses it if necessary, transports it to the first cleaning machine 31a, transports the primary cleaning of the substrate to the second cleaning machine 31b, and transfers the substrate The secondary cleaning (finish cleaning) is sequentially performed and dried, and the dried substrate W is returned to the cassette of the load / unload unit 30.

  Here, for example, when the electrolytic processing of copper is performed using an ion exchange material (cation exchange material) 20 provided with a cation exchange group as the ion exchange group 18, copper is converted into the ion exchange group 18 of the ion exchange material 20 after the processing is completed. Therefore, the processing efficiency is reduced when the next processing is performed. Further, when electrolytic processing of copper is performed using an ion exchange material (anion exchange material) 20 provided with an anion exchange group as the ion exchange group 18, fine particles of copper oxide are generated on the surface of the ion exchange material 20. May adhere to the surface of the next processing substrate.

  Therefore, in this example, as shown in FIG. 4, a drain line 90 is connected to the liquid recovery tank 84, and the processed product taken into the ion exchange material 20 during processing is removed from the drain line 90. The regenerator 92 is connected, the liquid 22 regenerated in the regenerator 92 is stored in the storage tank 94, and the regenerated liquid 22 stored in the storage tank 94 is driven along with the driving of the liquid feed pump 96. The liquid is supplied from the liquid supply nozzle 82 between the substrate W held by the substrate holding part 42 and the electrode part 48.

  In other words, the regeneration unit 92 has a pair of regeneration electrodes 100 and 102 at the upper and lower end portions, a partition wall 104 is disposed in the middle portion, the regeneration tank 106 on the one regeneration electrode 100 side, and the other regeneration electrode. It has the reproduction | regeneration container 110 which divided and formed the discharge tank 108 by the side of the electrode 102, respectively. A drain line 90 is connected to the inlet of the regeneration tank 106, and a liquid feed line 112 connected to the storage tank 94 is connected to the outlet. On the other hand, a liquid supply line 114 is connected to the inlet of the discharge tank 108, and a liquid discharge line 116 is connected to the outlet.

  As a result, the processed liquid 22 that has flowed into the liquid recovery tank 84 flows into the regeneration tank 106 once in a batch manner via the on-off valve 118 interposed in the drain line 90. On the other hand, in the discharge tank 108, the liquid (electrolyte) supplied from the liquid supply line 114 flows in one direction while filling the inside of the discharge tank 108 and is discharged from the liquid discharge line 116. It has become so.

  This partition wall 104 does not hinder the movement of impurity ions removed from the ion exchange material 20 contained in the liquid 22 to be regenerated, and flows inside the discharge tank 108 (including ions in the liquid). It is desirable to prevent the permeation of the liquid in the regeneration tank 106 and the permeation of the liquid in the regeneration tank 106 to the discharge tank 108 side. As a specific example, the ion exchanger can selectively permeate one of a cation or an anion, and the permeation of the liquid inside the membrane can be prevented by using a membrane-like ion exchanger. Can meet these requirements.

  The liquid supplied to the inside of the discharge tank 108 is, for example, an electrolytic solution, which generates a poorly soluble or insoluble compound by a reaction with ions having high conductivity and removed from the ion exchange material 20 subjected to regeneration. It is desirable that the liquid does not. In other words, this liquid is for discharging ions that have moved from the ion exchange material 20 subjected to regeneration and passed through the partition wall 104 to the outside of the system by the flow of the liquid, and thus have high conductivity and ion exchange. By supplying a liquid that does not produce an insoluble compound by reaction with ions removed from the substance 20, the electrical resistance of this liquid is lowered to reduce the power consumption of the regenerating unit 92, and in addition, the reaction with impurity ions It is possible to prevent insoluble compounds (secondary products) from being generated and attached to the partition walls 104. This liquid is selected depending on the type of impurity ions to be discharged. For example, sulfuric acid having a concentration of 1 wt% or more can be used as the ion exchange material 20 used for electrolytic polishing of copper. .

  Furthermore, one reproduction electrode 100 is electrically connected to one electrode (for example, a cathode) of the reproduction power source 120, and the other reproduction electrode 102 is electrically connected to the other electrode (for example, an anode) of the reproduction power source 120. Is done.

  Here, as the partition wall 104, in this example, an ion exchanger having the same ion ion exchange group as the ion exchange group imparted to the ion exchange material 20 is used. That is, if a cation exchange material having a cation exchange group is used as the ion exchange material 20, a cation exchanger is used as the partition wall (ion exchanger) 104, and an anion having an anion exchange group is used as the ion exchange material 20. If an exchange material is used, an anion exchanger is used as the partition wall (ion exchanger) 104.

  Further, when a cation exchange material is used as the ion exchange material 20, as shown in FIG. 4, the regeneration electrode 100 on the regeneration tank 106 side serves as an anode, and the regeneration electrode 102 on the discharge tank 108 side serves as a cathode. When an anion exchange material is used as the substance 20, the regeneration electrode 100 on the regeneration tank 106 side is the cathode, and the regeneration electrode 102 on the discharge tank 108 side is the anode.

  In the regeneration unit 92, the liquid 22 used for processing and recovered in the liquid recovery tank 84 is temporarily stored in the regeneration tank 106 by a batch method. In this state, one electrode (for example, cathode) of the regeneration power source 120 is connected to the regeneration electrode 100 on the regeneration tank 106 side, and the other electrode (for example, anode) is connected to the regeneration electrode 102 on the discharge tank 108 side. A voltage is applied between the electrodes 100 and 102 and a liquid is introduced into the discharge tank 108 so that the liquid flows in one direction in the discharge tank 108 and flows out to the outside.

  At this time, as described above, the regeneration electrode 100 on the regeneration tank 106 side is set to have a polarity opposite to that of the ion exchange material 20 (and the partition wall 104). That is, when the ion exchange material 20 (and the partition wall 104) to which a cation exchange group is added is used, the regeneration electrode 100 on the regeneration tank 106 side is the anode and the discharge tank 108 side is used, as shown in FIG. The reproduction electrode 102 is made to be a cathode. When an ion exchange material 20 (and partition wall 104) to which an anion exchange group is added is used, conversely, the regeneration electrode 100 on the regeneration tank 106 side is the cathode and the regeneration electrode 102 on the discharge tank 108 side is the cathode. Try to be the anode.

  As a result, the processed product (ion) taken into the ion exchange group 18 of the ion exchange material 20 contained in the liquid 22 once stored in the regeneration tank 106 is moved toward the discharge tank 108, and the partition wall 104. The ions exchanged are guided to the discharge tank 108, and the ions moved to the discharge tank 108 are discharged out of the system by the flow of the liquid supplied into the discharge tank 108 to regenerate the ion exchange material 20. At this time, when an ion exchange material 20 to which a cation exchange group is added is used, cations taken into the cation exchange group of the ion exchange material 20 pass through the partition wall 104 and move into the discharge tank 108. When an anion exchange group-added group is used, the anion taken into the anion exchange group of the ion exchange material 20 passes through the partition wall 104 and moves into the discharge tank 108, and the ion exchange material 20. Is played.

  Here, as described above, by using an ion exchanger having the same ion exchange group as the ion exchange material 20 to be regenerated as the partition wall 104, the partition wall of impurity ions in the ion exchange material 20 ( The movement of the inside of the ion exchanger (104) is prevented from being hindered by the partition wall (ion exchanger) 104, the power consumption is prevented from increasing, and the liquid and discharge tank on the regeneration tank 106 side across the partition wall 104. It is possible to prevent the 108-side liquid (including ions in the liquid) from penetrating each other, thereby preventing recontamination of the ion exchange material 20 after regeneration. Further, by supplying a liquid that has a conductivity of 50 μS / cm or more and does not generate a hardly soluble or insoluble compound by reaction with ions removed from the ion exchange material 20 into the discharge tank 108, The electric resistance is lowered to reduce the power consumption of the reproducing part, and insoluble compounds (secondary products) generated by reaction with impurity ions adhere to the partition wall 104 and the electric resistance between the reproducing electrodes 100 and 102 is reduced. It can prevent that it changes and control becomes difficult.

  As described above, the regeneration unit 92 regenerates the ion exchange material 20 and supplies the liquid 22 containing the regenerated ion exchange material 20 between the substrate W held by the substrate holding unit 42 and the electrode unit 48. It is indispensable in the electrolytic processing apparatus in which the liquid 22 containing the fresh ion exchange material 20 is always supplied between the substrate W and the processing electrode 44 and the feeding electrode 46, and the conventional ion exchanger is fixedly used. It is possible to eliminate work such as replacement of the existing ion exchanger. In the above description, the batch type is used, but the reproduction may be performed by continuous processing.

  FIG. 10 is a block diagram showing another example of regeneration of an ion exchange material. In this example, first, an ion exchange material that has incorporated a processed product during processing is separated from a liquid, and then the ion exchange material separated from the liquid. Is introduced into the regenerating solution, whereby the processed product incorporated in the ion exchange material is removed from the ion exchange material. Then, the ion exchange material from which the processed product has been removed is added to the solution again for use. As this regeneration solution, an acid solution is used when a cation exchange group is used as an ion exchange group imparted to an ion exchange material, and an alkaline solution is used when an anion exchange group is used.

  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.

It is a figure which shows one manufacture example of a copper wiring board in order of a process. It is a figure attached | subjected to description of the principle when supplying and processing the liquid containing an ion exchange substance between a process electrode and a to-be-processed object. It is a top view which shows the structure of the substrate processing apparatus provided with the electrolytic processing apparatus of embodiment of this invention. It is a longitudinal cross-sectional view of the electrolytic processing apparatus shown in FIG. It is a top view of the electrode part of the electrolytic processing apparatus shown in FIG. 6A is a plan view showing a rotation prevention mechanism in the electrolytic processing apparatus of FIG. 4, and FIG. 6B is a cross-sectional view taken along line AA of FIG. 6A. It is a figure which shows the relationship between the process electrode in a process, and a to-be-processed object (board | substrate). It is a graph which shows the relationship between the residual level | step difference of the surface of an electroconductive film, and the amount of processing at the time of changing distance between a to-be-processed object (board | substrate) and an electrode. FIG. 9 (a) shows the relationship between the current flowing when electrolytic processing is performed on the surface of the substrate on which a different material is deposited, and FIG. 9 (b) shows the relationship between the applied voltage and time, respectively. It is a graph to show. It is a block diagram which shows the other example of the reproducing part.

Explanation of symbols

4 Wiring groove 6 Copper film (conductive film)
7 Seed layer (conductive film)
DESCRIPTION OF SYMBOLS 10 Workpiece 12 Processing electrode 14 Power supply 16 Base material 18 Ion exchange group 20 Ion exchange substance 22 Liquid 30 Load / unload unit 31a, 31b Washing machine 32 Reversing machine 34 Electrolytic processing device 36 Transfer robot 38 Monitor unit 42 Substrate holding unit 44 Processing electrode 46 Power supply electrode 48 Electrode unit 50 Power source 58 Oscillating shaft 59 Autorotation motor 60 Hollow motor 62 Spindle 66 Autorotation prevention mechanism 82 Liquid supply nozzle 84 Liquid recovery tank 90 Drain line 92 Regeneration unit 94 Storage tank 96 Liquid feed pump 100 , 102 Regeneration electrode 104 Partition 106 Regeneration tank 108 Discharge tank 110 Regeneration container 112 Liquid feed line 114 Liquid supply line 116 Liquid discharge line 120 Regeneration power source

Claims (12)

A machining electrode that is freely accessible to the workpiece;
A feeding electrode for feeding power to the workpiece;
A liquid supply unit for supplying a liquid containing an ion exchange material having a size smaller than a distance 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 drive mechanism for causing relative movement between the workpiece and at least one of the processing electrode or the feeding electrode;
An electrolytic processing apparatus that performs electrolytic processing by bringing the workpiece close to the processing electrode until the distance to the processing electrode becomes 10 μm or less without contact.   The electrolytic processing apparatus according to claim 1, wherein the ion exchange material is contained in the liquid in an amount of 1 to 90% by weight.   3. The electrolytic processing apparatus according to claim 1, wherein the ion exchange material has a size capable of smoothly passing through a gap between the workpiece and the processing electrode.   4. The electrolytic processing apparatus according to claim 1, wherein the liquid is one of ultrapure water, pure water, a liquid having an electric conductivity of 500 μS / cm or less, or an electrolytic solution. 5.   5. The electrolytic processing apparatus according to claim 1, further comprising a regeneration unit that removes the processed product taken into the ion exchange material during processing from the ion exchange material. 6.   The regeneration unit is configured to separate the ion exchange material from the liquid and disperse the ion exchange material in the regeneration solution to remove a processed product taken into the ion exchange material. Item 6. The electrolytic processing apparatus according to Item 5.   The regeneration unit is configured to receive the liquid containing the ion exchange material in a regeneration tank, and apply an electric field to the liquid in the regeneration tank to remove a processed product taken into the ion exchange material. The electrolytic processing apparatus according to claim 5, wherein: The workpiece to be fed by the feeding electrode and the machining electrode are arranged in a non-contact manner and close to each other until the distance between them is 10 μm or less,
Supplying a liquid containing an ion exchange material having a size smaller than a distance 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,
An electrolytic machining method, wherein the workpiece and at least one of the machining electrode and the feeding electrode are moved relative to each other.   9. The electrolytic processing method according to claim 8, wherein the ion exchange material is contained in the liquid in an amount of 1 to 90% by weight.   10. The electrolytic processing method according to claim 8, wherein a processed product taken into the ion exchange material during processing is removed from the ion exchange material.   The electrolytic processing method according to claim 10, wherein the ion exchange material is separated from the liquid and dispersed in a regenerating solution to remove a processed product taken into the ion exchange material.   The electrolytic processing method according to claim 10, wherein an electric field is applied to the liquid containing the ion exchange material to remove a processed product taken into the ion exchange material.

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