JP2004017177A - Fixing methods, fixing structure for ion exchanger and electrochemical machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing method, a fixing structure, and an electrochemical machining device for an ion exchanger easily fixed with the ion exchanger in a closely contacted state with the surface of an electrode. <P>SOLUTION: When the ion exchanger 56 used for electrochemical machining is fixed in close contact with electrodes 50, 52, the ion exchanger 56 is located between an electrode support part 48c at which electrodes 50, 52 are exposed and a fixture 90 which can be freely fitted to the periphery of the electrode support part 48c, and the electrode support part 48c is fit to the fixture 90. Thereby, the ion exchanger 56 is fixed with its outer peripheral part clamped between the fixture 90 and the electrode support part 48c. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ion exchanger fixing method, a fixing structure, and an electrolytic processing apparatus, and more particularly, to an electrolytic processing for processing a conductive material on a substrate surface such as a semiconductor wafer or removing impurities attached to the substrate surface. The present invention relates to a method for fixing an ion exchanger, a fixing structure, and an electrolytic processing apparatus.
[0002]
[Prior art]
In recent years, a trend of using copper (Cu) having low electric resistivity and high electromigration resistance instead of aluminum or aluminum alloy as a wiring material for forming a circuit on a substrate such as a semiconductor wafer has become remarkable. . This type of copper wiring is generally formed by embedding copper in a fine recess provided on the surface of a substrate. As a method of forming the copper wiring, there are methods such as CVD, sputtering and plating. In any case, copper is formed on almost the entire surface of the substrate, and unnecessary copper is formed by chemical mechanical polishing (CMP). Is to be removed.
[0003]
FIG. 12 shows a manufacturing example of this type of copper wiring board W in the order of steps. First, as shown in FIG. 12 (a), on the conductive layer 1a on the semiconductor substrate 1 on which the semiconductor element is formed. SiO ₂ An insulating film 2 such as an oxide film or a Low-K material film is deposited, a contact hole 3 and a trench 4 for wiring are formed by lithography and etching technology, and a barrier film 5 made of TaN or the like is further formed thereon. A seed layer 7 is formed thereon as a power supply layer for electrolytic plating.
[0004]
Then, as shown in FIG. 12B, copper is applied to the surface of the substrate W to fill the contact holes 3 and the grooves 4 of the semiconductor substrate 1 with copper, and a copper film is formed on the insulating film 2. 6 is deposited. Thereafter, the copper film 6 and the barrier film 5 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 trench 4 for wiring and the insulating film 2 are removed. Is made almost flush with the surface. 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 the precision of all the components of equipment have been advanced, and the fabrication in the submicron region has become general, the influence of the processing method itself on the characteristics of the material has been increasing more and more. Under such circumstances, in a machining method in which a tool removes a workpiece while physically destroying it, as in conventional machining, the processing creates many defects in the workpiece. As a result, the characteristics of the workpiece deteriorate. Therefore, a problem is how to perform processing without deteriorating the properties of the material.
[0006]
Special polishing methods developed as means for solving this problem include chemical polishing, electrolytic processing, and electrolytic polishing. In these processing methods, in contrast to conventional physical processing, removal processing is performed by causing a chemical dissolution reaction. Therefore, defects such as a work-affected layer and dislocations due to plastic deformation do not occur, and the above-described problem of working without impairing the properties of the material is achieved.
[0007]
As an electrolytic process, a process using an ion exchanger has been developed. This means that the ion exchanger attached to the processing electrode and the ion exchanger attached to the power supply electrode are brought into contact with or close to the surface of the workpiece, and a voltage is applied between the processing electrode and the power supply electrode via a power supply. A liquid, such as ultrapure water, is supplied from the liquid supply section between the processing electrode and the power supply electrode and the workpiece while applying the voltage to remove the surface layer of the workpiece.
[0008]
Conventionally, the ion exchanger used for this type of electrolytic processing is generally attached to the exposed surface of the working electrode or power supply electrode by screwing its outer periphery or attaching it using an adhesive tape or the like. By doing so, it has been fixed to the outer peripheral portion of the electrode or the support having the electrode.
[0009]
[Problems to be solved by the invention]
Here, as described above, the ion exchanger used in this type of electrolytic processing is desirably fixed in a state of being in close contact with the exposed surfaces of the processing electrode and the power supply electrode in order to achieve uniform processing accuracy. However, it was difficult to make the ion exchanger adhere to the electrode.
[0010]
For this reason, if electrolytic processing is continued with the ion exchanger fixed with screws or adhesive tape, etc., the fixation of the ion exchanger will be incomplete, and the ion exchanger will easily move and uniformity of processing accuracy will be maintained. Is impaired.
[0011]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a method, a fixing structure, and an electrolytic processing apparatus for an ion exchanger in which an ion exchanger can be easily and quickly fixed in a state of being in close contact with the surface of an electrode. The purpose is to provide.
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, when the ion exchanger used for electrolytic processing is closely attached to the electrode and fixed, the fixing jig which can be fitted around the electrode supporting portion with the electrode exposed and the outer periphery of the electrode supporting portion. By positioning the ion exchanger between them and fitting the fixing jig to the electrode support, the outer periphery of the ion exchanger is sandwiched between the fixing jig and the electrode support. And fixing the ion exchanger.
[0013]
Thus, by simply pushing the fixing jig into the electrode support, the frictional force generated between the fixing jig, the ion exchanger and the electrode support at this time uniformly pulls the ion exchanger outward. Then, the ion exchanger is uniformly extended (with a certain tension applied) by this tensile force, whereby the ion exchanger can be automatically brought into close contact with the surface of the electrode support and fixed.
[0014]
In the invention according to claim 2, the fixing jig is composed of a pair of split jigs, and an outer peripheral portion of the ion exchanger is sandwiched between the split jigs, and the split jig is fixed to the electrode support portion. The method for fixing an ion exchanger according to claim 1, wherein the ion exchanger is pressed.
As described above, the outer peripheral portion of the ion exchanger is sandwiched by the dividing jig, the ion exchanger is temporarily fixed in advance by the dividing jig (fixing jig), and is pushed into the electrode supporting portion. In addition, it is possible to prevent the slipping from occurring between the ion exchanger and the fixing jig, and to fix the ion exchanger so that a constant tension is always applied to the ion exchanger.
[0015]
According to a third aspect of the present invention, in fixing an ion exchanger used for electrolytic processing in close contact with an electrode, an ion exchanger fixing jig is disposed outside the electrode, and the ion exchanger is fixed by the ion exchanger fixing jig. A method for fixing an ion exchanger, comprising holding an exchanger and supporting the ion exchanger with tension while giving tension to the ion exchanger.
[0016]
According to a fourth aspect of the present invention, there is provided an ion exchanger fixing structure for fixing an ion exchanger used for electrolytic processing in close contact with an electrode, the electrode supporting portion exposing the electrode and the outer periphery of the electrode supporting portion. A fixing jig that can be fitted to the electrode supporting portion, the outer peripheral portion of the ion exchanger is sandwiched between the electrode support portion and the fixing jig, and the ion exchanger is extended and fixed on the electrode surface. A fixing structure of an ion exchanger characterized by the following.
[0017]
In the invention according to claim 5, the fixing jig comprises a pair of split jigs, and an outer peripheral portion of a portion of the ion exchanger covering the electrode support is sandwiched between the split jigs. The fixing structure for an ion exchanger according to claim 4, wherein:
[0018]
According to a sixth aspect of the present invention, there is provided an electrode supporting portion that exposes an electrode, a fixing jig that can be fitted around the outer periphery of the electrode supporting member, and a jig disposed between the electrode supporting portion and the fixing jig. An ion exchanger, and an ion exchanger fixing device configured to sandwich and fix an outer peripheral portion of the ion exchanger between the electrode support portion and the fixing jig. It is an electrolytic processing apparatus.
[0019]
The invention according to claim 7 is such that the electrode support portion and the fixing jig are relatively moved to sandwich and fix the outer peripheral portion of the ion exchanger between the electrode support portion and the fixing jig. The electrolytic processing apparatus according to claim 6, wherein:
[0020]
Thus, when the ion exchanger becomes dirty, first, at least one of the fixing jig and the electrode support is moved in a direction in which the two are relatively separated from each other to release the fixation of the ion exchanger. After traveling, at least one of the fixing jig and the electrode support is moved in a direction in which both are relatively approached to fix the ion exchanger, so that the ion exchanger can be continuously exchanged and used. it can.
[0021]
The invention according to claim 8 is characterized in that the ion exchanger disposed between the electrode support portion and the fixing jig is a freely movable ion exchanger. It is an electrolytic processing apparatus.
[0022]
According to a ninth aspect of the present invention, the ion exchanger is configured to be endless and capable of traveling in one direction, and a regenerating unit for regenerating the ion exchanger is provided at a position along a traveling path of the ion exchanger. The electrolytic processing apparatus according to claim 8, wherein: Thus, while the ion exchanger is fixed and part of the ion exchanger is used for processing, the other part of the ion exchanger not used for processing is regenerated by the regenerating unit, and the ion exchanger is removed. After running in one direction, the operation of fixing the same is sequentially repeated, so that the endless ion exchanger can be circulated and used while traveling in one direction.
[0023]
The invention according to claim 10 is characterized in that the ion exchanger is configured to be capable of traveling in both directions, and is located on both sides of the electrode support along the traveling direction of the ion exchanger. 9. The electrolytic processing apparatus according to claim 8, further comprising: a reproducing unit for reproducing.
Thus, while the ion exchanger is fixed and a part of the ion exchanger is used for processing, another part of the ion exchanger not used for processing is regenerated by the regenerating unit, and the ion exchanger is regenerated. By alternately replacing the regenerated part with a part of the ion exchanger used for the processing, the elongated ion exchanger can be used repeatedly.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following example, an example is shown in which a substrate is used as a workpiece and the present invention is applied to an electrolytic processing apparatus (electrolytic polishing apparatus) configured to remove (polish) copper deposited on the surface of the substrate. It is needless to say that the present invention can be applied to a substrate other than a substrate and further applicable to other electrolytic processing.
[0025]
FIG. 1 and FIG. 2 show an electrolytic processing apparatus 36a having an ion exchanger fixing structure according to an embodiment of the present invention. The electrolytic processing apparatus 36a is provided at a free end of a swing arm 44 that is swingable in a horizontal direction and holds a substrate W downward (face down) by suction. And a vertically arranged electrode section 48 in which the fan-shaped processing electrode 50 and the power supply electrode 52 are exposed such that the surfaces (upper surfaces) of the processing electrode 50 and the power supply electrode 52 are flush with each other. I have. On the upper surface of the electrode portion 48, a membrane-like ion exchanger 56 is attached so as to integrally cover the surfaces of the processing electrode 50 and the power supply electrode 52.
[0026]
Here, in this example, as the electrode portion 48 having the processing electrode 50 and the power supply electrode 52, an electrode portion having a diameter slightly larger than the diameter of the substrate W held by the substrate holding portion 46 is used, and the electrode portion 48 is moved relatively. (In this case, scroll movement), so that the entire surface of the substrate W is simultaneously electrolytically machined.
[0027]
The ion exchanger 56 is made of, for example, a nonwoven fabric provided with an anion exchange ability or a cation exchange ability. The cation exchanger preferably carries a strongly acidic cation exchange group (sulfonic acid group), but may also carry a weakly acidic cation exchange group (carboxyl group). The anion exchanger preferably has a strongly basic anion exchange group (quaternary ammonium group), but may have a weakly basic anion exchange group (tertiary or lower amino group).
[0028]
Here, for example, a nonwoven fabric having a strong base anion exchange ability is obtained by so-called radiation graft polymerization in which a nonwoven fabric made of polyolefin having a fiber diameter of 20 to 50 μm and a porosity of about 90% is irradiated with γ-rays and then subjected to graft polymerization. , A 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 the graft chain to be introduced. In order to perform the graft polymerization, for example, acrylic acid, styrene, glycidyl methacrylate, further using a monomer such as sodium styrenesulfonate, chloromethylstyrene, by controlling the concentration of these monomers, reaction temperature and reaction time, The amount of graft to be polymerized can be controlled. Therefore, the ratio of the weight after the graft polymerization to the weight of the raw material before the graft polymerization is referred to as a graft ratio, and the graft ratio can be up to 500%. , At most 5 meq / g.
[0029]
The nonwoven fabric provided with the strongly acidic cation exchange ability was irradiated with γ-rays on the polyolefin nonwoven fabric having a fiber diameter of 20 to 50 μm and a porosity of about 90% in the same manner as in the method of providing the strong basic anion exchange ability. It is produced by introducing a graft chain by a so-called radiation graft polymerization method in which post-graft polymerization is performed, and then treating the introduced graft chain with, for example, heated sulfuric acid to introduce a sulfonic acid group. Further, by treating with heated phosphoric acid, a phosphate group can be introduced. Here, the graft ratio can be up to 500%, and the ion exchange group introduced after graft polymerization can be up to 5 meq / g.
[0030]
The material of the material of the ion exchanger 56 may be a polyolefin-based polymer such as polyethylene or polypropylene, or other organic polymers. Examples of the material form include, in addition to the nonwoven fabric, a woven fabric, a sheet, a porous material, a short fiber, a net, and the like.
[0031]
Here, polyethylene and polypropylene can be irradiated with radiation (γ-rays and electron beams) to the material first (pre-irradiation) to generate radicals in the material and then react with the monomer to undergo graft polymerization. . As a result, a graft chain having high uniformity and low impurities is obtained. On the other hand, other organic polymers can be radically polymerized by impregnating a monomer and irradiating (simultaneously irradiating) radiation (γ-ray, electron beam, ultraviolet ray) thereto. In this case, although it lacks uniformity, it can be applied to most materials.
[0032]
As described above, since the ion exchanger 56 is formed of a nonwoven fabric having an anion exchange ability or a cation exchange ability, the liquid such as pure water or ultrapure water or an electrolytic solution flows through the inside of the nonwoven fabric due to water permeability. By freely moving, an ion exchange reaction can be easily performed between the ions in the liquid phase and the ion exchange groups of the ion exchanger.
[0033]
Here, if the ion exchanger 56 is configured to have one of the anion exchange ability and the cation exchange ability, not only the material to be processed which can be electrolytically processed is restricted, but also impurities are easily generated due to the polarity. In view of this, the ion exchanger 56 may be integrally formed by arranging an anion exchanger having an anion exchange ability and a cation exchanger having a cation exchange ability concentrically. Further, an anion exchanger having an anion exchange ability and a cation exchanger having a cation exchange ability may be overlapped or formed in a fan shape and arranged alternately. Further, both the anion exchange ability and the cation exchange ability may be provided to the ion exchanger 56 itself. Examples of such an ion exchanger include an amphoteric ion exchanger in which anion exchange groups and cation exchange groups are arbitrarily distributed, and a bipolar ion in which cation exchange groups and anion exchange groups are present in layers. Examples of the exchanger include a mosaic ion exchanger in which a portion having a cation exchange group and a portion having an anion exchange group are arranged in parallel in the thickness direction. It is needless to say that the ion exchanger 56 having one of the anion exchange ability and the cation exchange ability may be properly used according to the material to be processed.
[0034]
The swing arm 44 that swings the substrate holding unit 46 moves up and down via a ball screw 62 in accordance with the driving of the vertical motor 60, and the upper end of a swing shaft 66 that rotates in accordance with the driving of the swing motor 64. It is connected to. The substrate holding section 46 is connected to a rotation motor 68 attached to the free end of the swing arm 44, and rotates (rotates) with the rotation of the rotation motor 68.
[0035]
The electrode portion 48 is directly connected to the hollow motor 70, and performs a scroll operation (translational rotational movement) with the driving of the hollow motor 70. At the center of the electrode section 48, a through hole 48a is provided as a pure water supply section for supplying pure water, more preferably ultrapure water. The through-hole 48a is provided with a pure water supply extending through the hollow portion of the hollow motor 70 through a through-hole 73a provided in the crankshaft 73 directly connected to the drive shaft of the hollow motor 70 for performing the scroll operation. Connected to tube 72. Pure water or ultrapure water is supplied through the through-hole 48a, and then supplied to the entire processing surface through the water-absorbing ion exchanger 56.
[0036]
Here, pure water is, for example, water having an electric conductivity (1 atm, 25 ° C. converted value, the same applies hereinafter) of 10 μS / cm or less, and ultrapure water is, for example, water having an electric conductivity of 0.1 μS / cm or less. It is. Note that a liquid having an electric conductivity of 500 μS / cm or less or an arbitrary electrolyte may be used instead of pure water. By supplying a liquid during processing, processing instability due to processing products, gas dissolution, and the like can be removed, and uniform processing with good reproducibility can be obtained.
[0037]
In this example, a plurality of fan-shaped electrode plates 76 are embedded on the upper surface of the electrode portion 48 so as to be flush with each other in the circumferential direction, and the cathode and anode of the power supply 80 are alternately connected to the electrode plate 76. By doing so, the electrode plate 76 connected to the cathode of the power supply 80 becomes the processing electrode 50, and the electrode plate 76 connected to the anode becomes the power supply electrode 52. This is because, for example, in the case of copper, the electrolytic processing action occurs on the cathode side. Depending on the material to be processed, the cathode side may be the power supply electrode and the anode side may be the 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, so that the electrode plate 76 connected to the cathode of the power supply 80 becomes the processing electrode 50 and the electrode plate connected to the anode. 76 is to be the power supply electrode 52. On the other hand, in the case of, for example, aluminum or silicon, since an electrolytic processing action occurs on the anode side, the electrode connected to the anode of the electrode can be used as a processing electrode and the cathode side can be used as a power supply electrode.
[0038]
As described above, the processing electrode 50 and the power supply electrode 52 are divided and provided alternately along the circumferential direction of the electrode portion 48, so that a fixed power supply portion to the conductive film (workpiece) of the substrate is unnecessary. As a result, the entire surface of the substrate can be processed. Further, by changing the positive or negative in a pulsed or periodic manner (alternating current), the electrolytic product is dissolved, and the flatness can be improved by the multiplicity of processing repetition.
[0039]
Here, in the processing electrode 50 and the power supply electrode 52, oxidation or elution of the electrode generally causes a problem due to an electrolytic reaction. Therefore, it is preferable to use carbon, a relatively inert noble metal, a conductive oxide, or a conductive ceramic as a material of the power supply electrode 52, rather than a metal or a metal compound widely used for the electrode. As an electrode made of this noble metal, for example, titanium or titanium is used as an underlying electrode material, and platinum or iridium is adhered to the surface by plating or coating, and sintering is performed at a high temperature to maintain stability and strength. One. 2. Description of the Related Art Ceramic products are generally obtained by heat treatment using inorganic materials as raw materials, and products having various characteristics are produced from various non-metals, metal oxides, carbides, nitrides, and the like. Some of these ceramics have conductivity. When the electrode is oxidized, the electric resistance of the electrode increases, causing an increase in applied voltage.In this way, by protecting the electrode surface with a material that is difficult to oxidize such as platinum and a conductive oxide such as iridium oxide, An increase in electrode resistance due to oxidation of the electrode material can be prevented.
[0040]
The ion exchanger 56 is fixed to the electrode portion 48 in a state in which it is in close contact with the upper surfaces of the processing electrode 50 and the power supply electrode 52 embedded inside the electrode portion 48 made of an insulator. That is, the electrode portion 48 has a large-diameter base portion 48b and a small-diameter cylindrical electrode support portion 48c integrally connected to an upper portion of the base portion 48b. The electrode support 48c is integrally covered with the ion exchanger 56, and the outer periphery of the ion exchanger 56 is fixed to the electrode support 48c and the electrode support 48c. By fixing the fixing jig 90 to the electrode support portion 48c by pressing the fixing jig 90 toward the electrode support portion 48c and fixing the fixing jig 90 to the electrode support portion 48c, the ion exchanger 56 is The outer peripheral portion is sandwiched between the outer peripheral surface of the fixing jig 90 and the inner peripheral surface of the electrode support portion 48c, and is fixed to the electrode support portion 48c. As a result, the ion exchanger 56 is tightly fixed to the exposed surfaces of the processing electrode 50 and the power supply electrode 52 while being uniformly extended (with a constant tension).
[0041]
That is, as shown in FIG. 2, by pressing the fixing jig 90 into the columnar electrode support portion 48c, the friction generated between the fixing jig 90, the ion exchanger 56, and the electrode support portion 48c at this time. The ion exchanger 56 is uniformly pulled outward by force, and the ion exchanger 56 is uniformly stretched (with a constant tension) by this pulling force, whereby the ion exchanger 56 is placed on the surface of the electrode support 48c. It can be automatically brought into close contact with and fixed.
[0042]
The fixing jig 90 is pushed down to a position where it comes into contact with the base portion 48b. Further, the outer peripheral portion of the fixing jig 90 is pressed by a holding jig 92 having a hook-like cross section. By fixing the portion 92a to the electrode portion 48 with a bolt 94, the fixing jig 90 is prevented from coming off. The holding jig 92 may be fixed to the electrode section 48 by another fixing means such as a pin or a crank.
[0043]
Here, by changing the protruding height of the electrode support portion 48c, the tension applied to the ion exchanger 56 can be adjusted. As shown in FIG. 3, the base portion 48b of the electrode portion 48 and the fixing jig are fixed. The tension applied to the ion exchanger 56 may be adjusted by interposing a ring-shaped spacer 96 between the spacer 90 and the spacer 90 and adjusting the thickness a of the spacer 96.
[0044]
Further, as shown in FIG. 4A, the fixing jig 90 is composed of a pair of divided jigs 90a and 90b. The divided jigs 90a and 90b sandwich the periphery of the ion exchanger 56 and use bolts or the like. In a temporarily fixed state, as shown in FIG. 4B, the fixing jig 90 including the pair of split jigs 90a and 90b may be pushed into the electrode support portion 48c of the electrode portion 48. This prevents slippage between the ion exchanger 56 and the fixing jig 90 when the fixing jig 90 is pushed in, so that a constant tension is always applied to the ion exchanger 56. Thus, the ion exchanger 56 can be fixed. In addition, the tension applied to the ion exchanger 56 can be adjusted by adjusting the thickness b of one of the divided jigs 90a positioned at this time.
[0045]
Next, the electrolytic processing (electrolytic polishing) by this electrolytic processing apparatus will be described.
First, the substrate W is sucked and held by the substrate holding section 46 of the electrolytic processing apparatus 36a, and the swing arm 44 is swung to move the substrate holding section 46 to a processing position just above the electrode section 48. Next, the vertical movement motor 60 is driven to lower the substrate holding unit 46, and the substrate W held by the substrate holding unit 46 is brought into contact with the surface of the ion exchanger 56 attached to the upper surface of the electrode unit 48, or Bring them closer.
[0046]
In this state, a predetermined voltage is applied from the power supply 80 between the processing electrode 50 and the power supply electrode 52, and the substrate holding unit 46 is rotated (rotated) to cause the electrode unit 48 to scroll. That is, the relative movement is performed by bringing the ion exchanger 56 into contact with or close to the electrode section 48. Further, the electrode portion 48 may not be a scroll, but may be a rotating electrode, and only one of the substrate W and the electrode portion 48 may be moved. At the same time, pure water or ultrapure water is supplied to the upper surface of the electrode section 48 from below the electrode section 48 through the through hole 48a, and pure water or ultrapure water is supplied between the processing electrode 50 and the power supply electrode 52 and the substrate W. Fill with water, liquid or electrolyte below 500 μS / cm. As a result, the electrode reaction and the movement of ions in the ion exchanger occur, and the electrolytic processing of, for example, the copper film 6 shown in FIG. Here, by allowing pure water or ultrapure water to flow inside the ion exchanger 56, efficient electrolytic processing can be performed.
[0047]
After the completion of the electrolytic processing, the electrical connection between the power source 80 and the processing electrode 50 and the power supply electrode 52 is cut off, and the rotation of the substrate holding unit 46 and the scroll movement of the electrode unit 48 are stopped. Thereafter, the substrate holding unit 46 is raised, and the swing arm 44 is swung to transfer the substrate W to the next step.
[0048]
This example shows an example in which pure water, preferably ultrapure water, is supplied between the electrode unit 48 and the substrate W. By performing electrolytic processing using pure water or ultrapure water containing no electrolyte in this way, extra impurities such as an electrolyte can be prevented from adhering or remaining on the surface of the substrate W. . Further, since the copper ions and the like dissolved by the electrolysis are immediately captured by the ion exchanger 56 in the ion exchange reaction, the dissolved copper ions and the like are deposited again on other portions of the substrate W or oxidized to fine particles. There is no contamination of the surface of the substrate W.
[0049]
Ultrapure water has a large specific resistance, making it difficult for current to flow.Therefore, the electrical resistance is reduced by shortening the distance between the electrode and the workpiece or by interposing an ion exchanger between the electrode and the workpiece. However, by further combining a small amount of the electrolytic solution, the electric resistance can be further reduced and the power consumption can be reduced. In the case of processing with an electrolytic solution, the portion to be processed of the workpiece covers a slightly wider range than the processing electrode. However, in the case of a combination of ultrapure water and an ion exchanger, almost no current flows in the ultrapure water. Only the area where the processing electrode of the workpiece and the ion exchanger are projected is processed.
[0050]
Instead of pure water or ultrapure water, an electrolytic solution obtained by adding an electrolyte to pure water or ultrapure water may be used. For example, by using an electrolytic solution of 500 μS / cm or less, electric resistance can be further reduced and power consumption can be reduced. As the electrolytic solution, for example, NaCl or Na ₂ SO ₄ Neutral salts such as HCl and H ₂ SO ₄ And the like, and furthermore, a solution of an alkali such as ammonia can be used, and may be appropriately selected and used depending on the characteristics of the workpiece. When an electrolytic solution is used, it is preferable that a slight gap be provided between the substrate W and the ion exchanger 56 so as not to make contact.
[0051]
Further, 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 μS / cm or less. A liquid having a resistivity of 1 μS / cm or less (specific resistance of 10 MΩ · cm or more) may be used. As described above, by adding a surfactant to pure water or ultrapure water, a layer having a uniform inhibitory action for preventing movement of ions at the interface between the substrate W and the ion exchanger 56 is formed. The concentration of ion exchange (dissolution of metal) can be reduced, and the flatness of the processed surface can be improved. Here, the surfactant concentration is desirably 100 ppm or less. If the value of the electric conductivity is too high, the current efficiency decreases and the processing speed decreases, but the electric conductivity is 500 μS / cm or less, preferably 50 μS / cm or less, and more preferably 0.1 μS / cm or less. By using a liquid having the following, a desired processing speed can be obtained.
[0052]
In addition, when the current density is increased by increasing the voltage to increase the processing speed, discharge may occur when the resistance between the electrode and the substrate (workpiece) is large. When electric discharge occurs, pitching occurs on the surface of the workpiece, making uniformity and flattening of the machined surface difficult. On the other hand, when the ion exchanger 56 is brought into contact with the substrate W, such electric discharge can be prevented from occurring because the electric resistance is extremely small.
[0053]
5 and 6 show an electrolytic processing apparatus 36b according to another embodiment of the present invention. The same or corresponding members as those of the electrolytic processing apparatus shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. This is the same in the following.
[0054]
This electrolytic processing device 36b is configured to take up a long ion exchanger 56a, which is bridged between a winding shaft 102 and a winding shaft 104 provided at both ends of a gantry 100, via a winding motor via a winding motor. The ion exchanger 104 is configured to be sequentially wound by being rotated and provided with an ion exchanger fixing device 106 for fixing the ion exchanger 56a.
[0055]
The ion exchanger fixing device 106 has an electrode unit lifting mechanism 108 for moving the electrode unit 48 up and down, and a fixing jig vertical moving mechanism 110 for moving a fixing jig 90 disposed above the electrode unit 48 up and down. are doing. Then, the ion exchanger 56a travels between the electrode portion 48 and the fixing jig 90, and while the ion exchanger 56a is stopped, the electrode portion 48 is raised and the fixing jig 90 is lowered. Thus, the fixing jig 90 is fitted into and fixed to the electrode support portion 48c of the electrode portion 48 with the ion exchanger 56a sandwiched therebetween, thereby supporting the electrode in a state where the ion exchanger 56a is uniformly extended. It is configured to be fixed to the portion 48c.
[0056]
In this example, the electrode unit 48 is installed on the gantry 100 that rotates with the driving of the hollow motor 70, and the electrode unit 48 is configured to perform a rotary motion, not a scroll motion. A cathode and an anode of a power supply 80 are alternately connected to the plate 76 via a slip ring 78.
[0057]
According to this example, when the used portion of the ion exchanger 56a fixed and used by the ion exchanger fixing device 106 is soiled, the electrode section 48 is first lowered, and the fixing jig 90 is raised. After the ion exchanger 56a is unlocked and the ion exchanger 56a is run for one time, the electrode section 48 is raised and the fixing jig 90 is lowered to fix the ion exchanger 56a, thereby performing ion exchange. The body 56a can be continuously replaced, and the ion exchanger 56a can be used in close contact with the surfaces of the processing electrode 50 and the power supply electrode 52.
[0058]
FIG. 7 shows a main part of an electrolytic processing apparatus according to still another embodiment of the present invention. In this example, one drive shaft 120 and three driven shafts 122 are arranged in parallel at the four corners of a trapezoid, and the endless ion exchanger 56b is wrapped around the outer periphery of these shafts 120 and 122. The ion exchanger 56b is configured to run and circulate in one direction, and a part of the ion exchanger 56b running above is fixed by the ion exchanger fixing device 106 and used for processing. A part of the ion exchanger 56b traveling below is reproduced by the reproducing unit 124 disposed along the traveling path.
[0059]
According to this example, while the ion exchanger 56b is fixed and a part of the ion exchanger 56b is used for processing, another part of the ion exchanger 56b not used for processing is reproduced by the reproducing unit 124. After running the ion exchanger 56b in one direction, the operation of fixing the same is repeated, so that the endless ion exchanger 56b can be circulated and used while traveling in one direction.
[0060]
Here, the regeneration of the ion exchanger means that the ions captured by the ion exchanger are exchanged with, for example, hydrogen ions in the case of a cation exchanger and hydroxide ions in the case of an anion exchanger. For example, when electrolytic processing of copper is performed using a cation exchanger provided with a cation exchange group (cation exchange group) as an ion exchanger, copper is captured by the cation exchange group. As the consumption of the cation exchange group by copper progresses, continuous processing becomes impossible. Further, when electrolytic processing of copper is performed using an anion exchanger provided with an anion exchange group (anion exchange group) as an ion exchanger, fine particles of copper oxide are formed on the surface of the ion exchanger (anion exchanger). Is generated and adhered, and may contaminate the surface of the next processing substrate. Then, in such a case, these adverse effects can be eliminated by regenerating the ion exchanger.
[0061]
FIG. 8 shows an example of the reproducing unit 124. The reproducing section 124 holds a fixed-side reproducing electrode section 132 in which one electrode 130 for reproduction is exposed on the surface and is buried, and holds the other electrode 134 for reproduction and fixes the surface of the electrode 134 to an ion exchanger for reproduction. A movable reproduction electrode portion 138 that can move up and down covered by 136, a liquid supply nozzle 140 that supplies a liquid for reproduction between the two electrode portions 132 and 138, and reproduction between a pair of electrodes 130 and 134 for reproduction. And a reproduction power supply 142 for applying a voltage for use.
[0062]
The regeneration ion exchanger 136 has the same ion exchange group as the ion exchanger 56b to be subjected to regeneration. In other words, if a cation exchanger having a cation exchange group is used as the ion exchanger 56b, a cation exchanger is also used as the regeneration ion exchanger 136, and the ion exchanger (to-be-processed ion exchanger) 56b is If an anion exchanger having an anion exchange group is used, an anion exchanger is used as the regeneration ion exchanger 136.
[0063]
Then, the surface of the electrode 130 of the fixed-side regeneration electrode section 132 is covered with the ion exchanger 56b for regeneration, and in this state, the moving-side regeneration electrode section 138 is regenerated by the regeneration ion exchanger 136 for regeneration. It is lowered so as to contact or approach the surface (upper surface) of 56b. In this state, a regeneration voltage is applied between the electrodes 130 and 134 such that the polarity of the electrode on the regeneration ion exchanger 136 side, that is, the electrode 134 is opposite to the polarity of the ion exchanger 56b. That is, when a cation exchanger having a cation exchange group is used as the ion exchanger 56b, the electrode 134 serves as a cathode and the electrode 130 serves as an anode, and the ion exchanger 56b uses an anion exchanger as the ion exchanger 56b. When used, the electrode 134 is an anode and the electrode 130 is a cathode. At the same time, pure water or ultrapure water is supplied from the liquid supply nozzle 140 between the two electrode portions 132 and 138, and the space between the two is filled with pure water or ultrapure water. The ion exchanger 136 is immersed in pure water or ultrapure water.
[0064]
Thus, the ions of the ion exchanger 56b are moved to the inside of the ion exchanger for regeneration 136 by an ion exchange reaction using the ion exchanger 56b as a solid electrolyte, and the ion exchanger 56b is regenerated. At this time, when a cation exchanger is used as the ion exchanger 56b, the cations taken into the ion exchanger 56b move into the regeneration ion exchanger 136, and when the anion exchanger is used. Then, the anions taken into the ion exchanger 56b move into the regeneration ion exchanger 136, and the ion exchanger 56b is regenerated.
[0065]
It is to be noted that a liquid or an electrolyte having an electric conductivity of 500 μS / cm or less may be used in place of the pure water or the ultrapure water as described above.
[0066]
FIG. 9 shows another example of the reproducing section 124, which has a circular concave section 138a that opens downward as the moving-side reproducing electrode section 138, and a lower opening end of the concave section 138a is used as a reproducing ion. By closing with the exchanger 136, a discharge section 150 partitioned by the ion exchanger for regeneration 136 was formed therein, and a disc-shaped electrode 134 was attached to the bottom of the recess 138a. Things. A liquid inlet 152 and a liquid outlet 154 communicating with the outer periphery of the discharge unit 150 are provided at both ends of the moving-side reproduction electrode unit 138 along the diameter direction, respectively. The liquid inlet 152 and the liquid outlet 154 The inlet pipe 156 and the liquid outlet pipe 158 are connected to each other. Other configurations are almost the same as the example shown in FIG.
[0067]
According to this example, by supplying the liquid from the liquid inlet tube 156 into the discharge unit 150 during the regeneration of the ion exchanger 56b, the liquid flowing in the discharge unit 150 in one direction and discharged from the liquid outlet tube 158 is discharged. The electrode 134 is immersed in this liquid. Thereby, the ions of the ion exchanger 56b are moved toward the electrode 134, passed through the regeneration ion exchanger 136, guided to the discharge unit 150, and the ions moved to the discharge unit 150 are supplied into the discharge unit 150. The discharged liquid flows out of the system and the ion exchanger 56b can be more efficiently regenerated.
[0068]
The liquid to be supplied into the discharge unit 150 is, for example, an electrolytic solution, preferably a liquid having a high conductivity and not generating a hardly soluble or insoluble compound by reaction with ions removed from the ion exchanger. As the liquid, for example, sulfuric acid having a concentration of 1 wt% or more can be used as a liquid used when regenerating an ion exchanger used for electrolytic polishing of copper.
[0069]
FIG. 10 shows a main part of an electrolytic processing apparatus according to still another embodiment of the present invention. In this example, a pair of winding and winding shafts 160 is provided on both sides of the ion exchanger fixing device 106. And a pair of intermediate shafts 162 are arranged in a gate shape, so that the ion exchanger 56c is configured to be able to travel in both directions (in the opposite direction to the normal direction). The reproducing units 124 are arranged between the two. Other configurations are the same as those in the example shown in FIG.
[0070]
According to this example, while the ion exchanger 56c is fixed by the ion exchanger fixing device 106 and a part of the ion exchanger 56c is not used for processing, another part of the ion exchanger 56c not used for processing is used. Is regenerated by the regenerating unit 124, and the part regenerated by the regenerating unit 124 of the ion exchanger 56c is alternately used with a part of the ion exchanger 56c used for processing, that is, for example, In FIG. 10, when the ion exchanger 56c is driven rightward, the portion reproduced by the regenerating unit 124 located on the right side downstream of the traveling direction is used for processing, and the ion exchanger 56c is driven leftward. In this case, by using the portion regenerated by the regenerating unit 124 located on the left side on the downstream side in the traveling direction for processing, the ion exchanger 56c can be used repeatedly until it is mechanically deteriorated, for example. That.
[0071]
In each of the above-described examples, a ring-shaped jig that covers the entire periphery of the electrode portion 48 is used as the fixing jig 90, and a more uniform tension is applied to the entire surface of the ion exchangers 56a to 56c. However, as shown in FIG. 11, a pair of fixing jigs 90a extending in a bar shape are disposed before and after in the traveling direction of the ion exchangers 56a to 56c, and the fixing jig 90a is lowered to thereby lower the ion exchanger 56a. To 56c may be fixed. The point is that the ion exchangers 56a to 56c need only be located on the outer periphery of the region used for processing, and can be held while applying tension to the ion exchangers 56a to 56c. The shape is not limited to the ring shape, but can be various shapes, and is mainly adjusted to the shape of the electrode.
[0072]
【The invention's effect】
As described above, according to the present invention, by simply pushing the fixing jig into the electrode support, the ion exchanger is pulled outward uniformly, and the ion exchanger is uniformly stretched by this pulling force ( While applying a certain tension), the ion exchanger can be automatically brought into close contact with the surface of the electrode support portion and fixed, thereby fixing the ion exchanger in the state of being in close contact with the surface of the electrode. It can be done easily and quickly.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an electrolytic processing apparatus having an ion exchanger fixing structure according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a state before an ion exchanger is fixed to an electrode support.
FIG. 3 is a cross-sectional view showing a main part of another example of the fixing structure of the ion exchanger.
FIG. 4 is a sectional view showing a main part of still another example of the fixing structure of the ion exchanger.
FIG. 5 is a sectional view showing an electrolytic processing apparatus according to another embodiment of the present invention.
6 is a cross-sectional view showing a main part of the ion exchanger fixing device provided in the electrolytic processing apparatus shown in FIG. 5 in a state where the ion exchanger is not fixed.
FIG. 7 is a sectional view showing a main part of an electrolytic processing apparatus according to still another embodiment of the present invention.
FIG. 8 is a cross-sectional view illustrating an example of a reproducing unit.
FIG. 9 is a cross-sectional view showing another example of the reproducing unit.
FIG. 10 is a sectional view showing a main part of an electrolytic processing apparatus according to still another embodiment of the present invention.
FIG. 11 is a plan view showing an outline of a modification of the ion exchanger fixing device.
FIG. 12 is a diagram illustrating an example of forming a copper wiring in order of process.
[Explanation of symbols]
36a, 36b electrolytic processing equipment
46 PCB holder
48 electrodes
48b Base part
48c electrode support
50 Processing electrode
52 Feeding electrode
56,56a, 56b, 56c ion exchanger
70 Hollow motor
72 Pure water supply pipe
76 electrode plate
78 Slip ring
80 power supply
90 Fixing jig
90a, 90b Split jig
92 Holding jig
96 spacer
102 Winding shaft
104 winding shaft
106 ion exchanger fixing device
108 Electrode lifting mechanism
110 Fixing jig vertical movement mechanism
124 playback unit
130,134 electrodes
132,138 Reproduction electrode part
136 Ion exchanger for regeneration
142 playback power
150 discharge section

Claims (10)

In fixing the ion exchanger used for electrolytic processing in close contact with the electrode,
Positioning the ion exchanger between the electrode support exposing the electrode and a fixing jig that can be fitted around the outer periphery of the electrode support,
An ion exchanger characterized in that the fixing jig is fitted to the electrode supporting portion to fix the ion exchanger with its outer peripheral portion sandwiched between the fixing jig and the electrode supporting portion. How to fix. The fixing jig comprises a pair of split jigs, and presses the split jig into the electrode support by holding an outer peripheral portion of the ion exchanger between the split jigs. 2. The method for immobilizing the ion exchanger according to 1. In fixing the ion exchanger used for electrolytic processing in close contact with the electrode,
Place the ion exchanger fixture on the outside of the electrode,
A method for fixing an ion exchanger, wherein the ion exchanger is held by the ion exchanger fixing jig, and the ion exchanger is supported by an electrode while giving tension to the ion exchanger. An ion exchanger fixing structure for fixing an ion exchanger used for electrolytic processing in close contact with an electrode,
Having an electrode supporting portion that exposes the electrode and a fixing jig that can be fitted around the outer periphery of the electrode supporting portion,
An ion exchanger fixing structure, wherein an outer peripheral portion of the ion exchanger is sandwiched between the electrode support portion and the fixing jig, and the ion exchanger is extended and fixed on the electrode surface. The fixing jig includes a pair of split jigs, and an outer peripheral portion of a portion of the ion exchanger covering the electrode support is sandwiched between the split jigs. Item 5. A fixing structure for an ion exchanger according to Item 4. An electrode support that exposes the electrode, a fixing jig that can be fitted around the outer periphery of the electrode support, and an ion exchanger that is disposed between the electrode support and the fixing jig.
An electrolytic processing apparatus comprising: an ion exchanger fixing device configured to sandwich and fix an outer peripheral portion of the ion exchanger between the electrode support portion and the fixing jig. The said electrode support part and the said fixing jig are moved relatively, and the outer peripheral part of the ion exchanger was pinched and fixed between this electrode support part and the fixing jig, The claim characterized by the above-mentioned. 7. The electrolytic processing apparatus according to 6. 8. The electrolytic processing apparatus according to claim 6, wherein the ion exchanger disposed between the electrode support and the fixing jig is a movable ion exchanger. The ion exchanger is configured to be endless and freely run in one direction, and a regenerating unit for regenerating the ion exchanger is provided at a position along a traveling path of the ion exchanger. 8. The electrolytic processing apparatus according to 8. The ion exchanger is configured to be capable of traveling in both directions, and a regenerating unit that regenerates the ion exchanger is provided on each side of the ion exchanger along the traveling direction across the electrode support unit. The electrolytic processing apparatus according to claim 8, wherein:

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