TW200301717A - Electrolytic processing apparatus and method - Google Patents

Abstract

There is provided an electrolytic processing apparatus and method that can effect processing of a substrate with high processing precision and can produce an intended form of processed substrate with high accuracy of form. The electrolytic processing apparatus includes: a holder for holding a substrate; a processing electrode that can come close to the substrate; a feeding electrode for feeding electricity to the substrate; an ion exchanger disposed in the space between the substrate and the processing electrode, or the substrate and the feeding electrode; a fluid supply section for supplying a fluid into the space; a power source for applying a voltage between the processing electrode and the feeding electrode; a drive sections for allowing the substrate and the processing electrode, facing each other, to make a relative movement; and a numerical controller for effecting a numerical control of the drive sections.

Description

200301717 V: Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to an electrolytic processing device and method, and particularly to a conductive material used for processing the surface of a substrate (such as a semiconductor wafer) or for removing adhesion to the substrate Electrolytic processing device and method for surface impurities. [Prior art] In recent years, it has been a clear tendency to use copper (Cu) with low resistivity and electron migration resistance (Cu) instead of Shao or Ming alloy as a substrate for forming a substrate (such as a semiconductor wafer). The material of the circuit (inner conne ti on circuit) ° copper interconnect is usually formed by filling copper into the fine grooves formed in the surface of the substrate. There are many known methods for forming The copper interconnect technology includes chemical vapor deposition (CVD), sputtering, and electroplating. According to any of these technologies, a copper film is formed on substantially the entire surface of the substrate, followed by chemical mechanical polishing ( chemical mechanical polishing (CMP) to remove excess copper. 8A to 8C illustrate an example of forming the substrate W with copper interconnections in the order of process steps. As shown in FIG. 8A, an insulating film 2 such as an oxide film or a low-dielectric-constant material film is deposited on a conductive layer 1a (a semiconductor device is formed therein), where the conductive layer 丨 a is In the semiconductor substrate 1, the contact holes 3 and the trenches 4 for interconnect lines are formed in the insulating film 2 by a lithography / etching technique. After that, the nitride button barrier layer 5 is formed on the entire surface, and a seed layer 7 is formed on the barrier layer 5 as a power supply for plating. ~~ Then, as shown in FIG. 8B, a steel electrode is performed on the surface of the substrate W,

200301717 V. Description of the invention (2) The contact hole 3 and the trench 4 are filled with copper, and a copper film 6 is deposited on the insulating film 2 at the same time. Next, the copper film 6 and the barrier layer 5 on the insulating film 2 are removed by chemical mechanical polishing, so that the surface of the copper film for interconnection lines filled in the contact holes 3 and the trenches 4 and the surface of the insulating film 2 are substantially They are located on the same plane, thereby forming an interconnection structure composed of a copper film 6 as shown in FIG. 8C. Components in different types of devices have recently become finer and require higher accuracy. Since sub-micron manufacturing techniques have been widely used, material properties are mainly affected by processing methods. In the case of using such a conventional machining method, a desired portion of a workpiece is physically destroyed and removed from the surface of the workpiece by a tool, so many defects may be generated to degrade the properties of the workpiece. Therefore, it becomes important to process without degrading the properties of the material. Several processing methods such as chemical grinding, electrolytic machining, and electrolytic grinding have been developed to solve this problem. In contrast to conventional physical processing, these methods use chemical decomposition reactions for removal processing or similar processing. Therefore, these methods are not affected by defects (such as altered layers and dislocations) caused by plastic deformation, so that processing can be performed without degrading the material properties. A processing method using a catalytic reaction of an ion exchanger and processing in ultrapure water has been developed as an electrolytic processing method. Fig. 9 illustrates the principle of this electrolytic processing method. FIG. 9 shows the ion state when the ion exchanger 12a mounted on the processing electrode 14 and the ion exchanger 12b mounted on the feeding electrode 16 are in contact with or close to the surface of the workpiece 10. The voltage is Powered by 17

«I1 314314.ptd Page 11 200301717 Five 'Description of Invention (3) Application > Between the processing electrode 14 and the feed electrode 16 and the liquid 18 (such as ultrapure water) is provided by the liquid supply unit 1 9 It is supplied between the processing electrode 14, the feeding electrode 16 and the workpiece 10. In the state of this electrolytic processing, 'water molecules 2 in a liquid such as ultrapure water 1 8 are efficiently dissociated into hydroxide ions 2 2 and hydrogen ions 2 4 using ion exchangers 1 2 a, 1 2 b. . The generated hydroxide ions 22 are transmitted to the surface of the workpiece 10 facing the processing electrode 14 by the electric field between the workpiece 10 and the processing electrode 14 and the flow of the liquid 18, thereby improving the workpiece. 1 0 The density of surrounding hydroxide ions 2 2, and the hydroxide ions 2 2 react with the atom 10 0 a of the workpiece 10, and the reaction product 2 6 generated by the reaction is decomposed in the liquid, and The flow of the liquid 18 removes the workpiece 10 along the surface of the workpiece 10, thereby completing the removal process of the surface of the workpiece 10. In the process of electrolytically processing conductive materials by ion exchangers using the pre-exposure method, the numerical control mechanism commonly used in conventional machining cannot be directly applied to this electrolytic processing. In this regard, the electrolytic machining method utilizes chemical interactions between hydroxide ions and workpiece atoms. Therefore, even when the workpiece and the tool (electrode) are not in contact with each other, the machining phenomenon still occurs. Therefore, electrolytic machining is different from the machining principle of machining by physically destroying the workpiece. More specifically, in general machining, a workpiece and a tool that are in contact with each other can be moved relative to each other so that the workpiece can be physically destroyed to complete the processing. When the processing volume reaches the desired processing volume, the workpiece can be separated from the tool without contact to terminate the progress and progress of the processing. Even when the tool crosses the surface of the workpiece, processing will not be performed. On the other hand, according to the electrolytic processing method that utilizes the chemical interaction between the reactive material and the workpiece, as mentioned earlier, even when the tool (electrode) is not in contact with the workpiece,

314314.ptd Page 12 200301717 V. Description of the invention (4) When the amount of the reactant reaches a certain level, processing will still occur. Therefore, when the tool (electrode) passes over the surface of the part of the workpiece that has been processed in a predetermined amount, the machining phenomenon inevitably occurs. Therefore, in order to process the conductive material with high processing accuracy to form the desired shape of the processed workpiece by electrolytic processing using the chemical interaction between the reactive material and the workpiece, a control system is needed, not only in mechanical The state of processing controls the state of contact between the workpiece and the tool (the position of the tool), and also controls the chemical interaction between reactive materials such as hydroxide ions and the atoms of the workpiece. SUMMARY OF THE INVENTION The present invention has been completed in view of the circumstances of the background art disclosed previously. Therefore, an object of the present invention is to provide an electrolytic machining device and method that can complete the machining of a workpiece having a conductive material (as a material to be processed) on its surface with high machining accuracy, and can form the shape of a machining workpiece with a high-precision appearance. In order to achieve the purpose of the previous disclosure, the present invention provides an electrolytic processing device. The device includes: a fixing base for detachably holding a workpiece; a processing electrode, which can approach or contact the workpiece held by the fixing base; For supplying electric power to a workpiece held by a fixed base; an ion exchanger arranged in at least one of a space between the workpiece and the processing electrode and a space between the workpiece and the feeding electrode; a fluid supply unit for transferring fluid It is supplied between a workpiece having an ion exchanger therein and at least one of the processing electrode and the feeding electrode; a power source for applying a voltage between the processing electrode and the feeding electrode; and a driving part for facing each other Right and fixed

314314.ptd Page 13 200301717 V. Description of the invention (5) Relative movement of the fixed workpiece and the processing electrode; and a numerical controller for performing numerical control of the driving part. The electrolytic processing device can compare the shape of the workpiece before or during processing with the desired shape of the workpiece after processing, and determine the processing amount (equivalent to the coordinate difference between the two shapes. ) Input the numerical controller and complete the numerical control of the driving part according to the input data. The driving part is used to make the workpiece and the processing electrode held by the fixed seat facing each other to perform relative movement. Under the numerical control The electrolytic processing device for advanced operations can be manufactured into the desired shape of the work piece. The power supply can supply a current or voltage controlled at a fixed value between the processing electrode and the feeding electrode. During electrolytic processing, When the current flowing between the processing electrode and the feeding electrode is controlled at a fixed value, the processing rate is fixed. In this situation, the processing amount depends on the product of the current value and the processing time. Therefore, between the processing electrode and the feeding electrode The current flowing between the electrodes is controlled at a fixed value, and the machining time is controlled by only numerical values (that is, the workpiece and the machining electrode (During the correct period), so that the electrolytic machining phenomenon (dwell time) occurs, and the desired machining workpiece shape with a high-precision shape can be obtained. # The numerical controller can drive the workpiece and processing such as the workpiece held by the holder by the drive unit. The relative motion speed between the electrodes is numerically controlled. When the relative speed between the workpiece and the processing electrode facing each other and held by the fixed seat is changed to perform the electrolytic processing, the variable relative motion speed can be changed. Numerical control, which enables electrolytic processing

314314.ptd Page 14 200301717 V. Description of the invention (6) An optimized processing time (residence time) is processed at a specific point on the processing surface of the workpiece. Alternatively, the numerical controller may numerically control the stop time of the relative step motion between the workpiece held by the fixed seat and the processing electrode by the driving section. When the electrolytic machining is performed in a relative stepping motion between the workpiece and the processing electrode held by the fixed seat facing each other, the stopping time in the movement is numerically controlled, which enables electrolytic machining to be performed on the workpiece. Optimized machining time (dwell time) at a specific point on the machined surface. The “\ relative step motion” as used herein means that one or both of the workpiece and the processing electrode move to cause the processing electrode to repeatedly move and stop the relative motion on the workpiece over a specific distance. The invention provides an electrolytic processing method, which includes: providing a processing electrode, a feeding electrode, and an ion exchanger, the ion exchanger being disposed in a space between a workpiece and a processing electrode held by a fixed seat, and between the workpiece and the feeding electrode In at least one of the spaces; when power is supplied to the workpiece from the feeding electrode, the processing electrode can approach or contact the workpiece held by the fixed seat; supply fluid to the workpiece and the processing electrode in which the ion exchanger is present, and The space between at least one of the feeding electrodes; applying a voltage between the processing electrode and the feeding electrode; and in the case of numerically controlled movement by a numerical controller, facing each other and held by the fixed seat The workpiece and the processing electrode can be moved relative to each other. The electrolytic processing method may include: measuring the shape of the workpiece before and / or during the processing;

314314.ptd Page 15 20031717 Description of the 5 'invention (7) The coordinate data is input into the numerical controller; and between the workpiece and the processing electrode held by the fixed base according to the coordinate difference between the measured shape and the desired shape The relative motion speed is numerically controlled. The electrolytic processing method may include: measuring a workpiece shape before and / or during processing; inputting coordinate data of the measured shape and a desired shape of the workpiece after processing into a numerical controller; and according to the measured shape and the desired shape The coordinate difference between the shapes is used to numerically control the stop time in the relative step motion between the workpiece and the processing electrode held by the fixed seat. ^ The previous disclosure and other objects, features, and advantages of the present invention will be coordinated with examples. The figure will become clear from the following description, which illustrates a preferred embodiment of the present invention. [Embodiment]-A preferred embodiment of the present invention will now be described with reference to the drawings. Although the embodiment described below is applied to an electrolytic processing apparatus (electrolytic polishing apparatus) using a substrate as a workpiece to be processed and removing (polishing) copper formed on the substrate surface, the present invention is undoubtedly applicable to other workpieces and other electrolytic processes. Processing ° Figure 1 shows an electrolytic processing apparatus according to a first embodiment of the present invention. The electrolytic processing device includes a substrate holder 30 for attracting and holding the substrate W facing up_the so-called 'face-up method' and an electrode tip 3 having a dish-like electrode portion 36 (made of an insulating material). 8. The electrode part 36 is embedded in the sector-shaped processing electrode 3 2 and the feeding electrode 3 4 which are staggered and exposed on the surface (lower surface), and the electrode head 38 is positioned above the substrate holder 30. The ion exchanger 40, consisting of one layer (laminate), is mounted below the electrode section 36.

314314.ptd Page 16 ------ V. Description of the invention (8) Surface, so as to cover the processing electrode 3 2 and the feeding substrate fixing base 30 are directly connected to the surface support shaft 42 of the hair pole 34 Upper end. The motor "does °, and supports and rotates freely between the substrate W and the processing electrode 32. The sub-distribution is held by the substrate fixing base 30, and is next to the support shaft 42. The same as & step leather, the first drive of movement Between the (first drive section) 44 and: 6 meshes with the support shaft 42 and the horse: actuated to rotate the substrate fixing seat 30 and 44 W (the first drive section) of the board. Q 疋 座 3 The substrate electrode head 3 held by 0 is connected upward to the end, and the base of the rotating arm 48 is connected to the free hollow rotating shaft 54 of the special-purpose rotating arm 48 by vertical movement: = of the rotating shaft 54 At the upper end, the bead screw 52 performs vertical movement. Actuation of the motor 5 ^ 50 and the gate 吝 of the substrate W and the processing electrode 32 held by the roller are used to move the substrate holder 30, and the motor 56 is positioned to rotate The second drive, which is relatively moving next to the shaft 54, moves vertically. The timing belt 58 rotates between the shaft 54 and the synchronizing portion 56 so that the motor (Π wheel 54 and the motor (the second drive rotating shaft 54 and the rotation) The arm 48 rotates together) 56), and the electrode head 38 is directly connected to *: The hollow horse pole of the substrate fixing base rotates with the third drive that generates relative movement between and the actuation of Jiugongdian (third drive unit) 60. In this embodiment, the two-core motor is an ion exchanger. 40 is composed of a pair of strongly acidic fibers 62a, 62b and a fiber 62a, which is inserted into the fiber 62a, and the "2 oxygen" is calculated. The strong acidic cations between bZa and 62b are replaced by a membrane 62c. Three-layer structure (laminated). Ion exchanger

3 ⑷] 4._

200301717 5; Description of the invention (9) (laminate) 40 has good water permeability and high hardness. In addition, the ion exchanger 40 has good flatness to the exposed surface (lower surface) of the substrate W. The structure of the ion exchanger 40 may be configured such that an ion exchanger film is used for the exposed surface, and a laminate of ion exchanger fibers is disposed above the exposed ion exchanger film. Preferably, each of the stacked layers 6 2 a, 6 2 b, and 6 2 c of the ion exchanger 40 has a strongly acidic cation exchange group (sulfonic acid group); however, a weakly acidic cation exchange can also be used. Base (carboxy) ion exchanger, ion exchanger with strong basic 1 anion exchange group (quaternary ammonium group), or ion exchanger with weak basic anion exchange group (three or lower grade amine group) . The non-woven fabric with a strong basic anion exchange group can be prepared, for example, by subjecting a polyolefin non-woven fabric having a fiber diameter of 20 to 50 micrometers and a porosity of about 90% to a so-called ray graft polymerization (radiati ο ngraftp ο 1 ymerizati ο n), the ray graft polymerization treatment includes irradiating 7 " rays on the non-woven fabric and subsequent graft polymerization treatment to introduce the graft chain; and then the introduced graft chain is aminated and introduced into the quarter Ammonium is based on it. The capacity of the ion-exchange groups introduced can be determined by the number of graft chains introduced. Graft polymerization can be performed using monomers such as acrylic acid, styrene, fluorenyl acrylate, sodium p-styrene sulfonate or chlorofluorenyl styrene (lolomethylstyrene), and the monomer concentration, reaction temperature, and reaction Control the number of grafting chains in time. Therefore, the grafting degree (that is, the ratio of the weight of the non-woven fabric after the graft polymerization treatment to the weight of the non-woven fabric before the graft polymerization treatment) can be at most 500%. In short, the ion exchange groups introduced after graft polymerization

3] 4314.ptd Page 18 200301717 V. Description of the invention (10) The maximum capacity can be 5 meq / g. The non-woven fabric with a strongly acidic cation exchange group can be prepared by the following method: a polyolefin non-woven fabric having a fiber diameter of 20 to 50 micrometers and a porosity of about 90%, as in the case of a non-woven fabric with a strong basic anion exchange group. The so-called ray-graft polymerization process includes irradiating 7-rays on the non-woven fabric and subsequent graft-polymerization process, thereby generating graft chains; and then processing the introduced graft chains with hot sulfuric acid to A sulfonic acid group is introduced therein. If the graft chain is treated with hot phosphoric acid, phosphate groups can be introduced. The grafting degree can be up to 500%, and the capacity of the ion-exchange groups introduced after the graft polymerization treatment can be up to 5 meq / g ° each of the stacks of the ion exchanger 4 0 6 2 a, 6 2 b, The substrate of 6 2 c may be a polyolefin such as polyethylene or polypropylene or any other organic polymer. In addition to the non-woven fabric, the ion exchanger may be in the form of a knitted fabric, a tape, a porous material, a mesh or a short fiber. When polyethylene or polypropylene is used as the substrate, the graft polymerization can be performed by firstly irradiating radiation (T-ray or electron beam) on the substrate (pre-irradiation) to generate a base, and then making the base Reacts with the monomers, so that graft chains with even impurities can be obtained. On the other hand, when an organic polymer other than polyolefin is used as the substrate, the substrate can be impregnated with a monomer and irradiated with radiation (r-ray, electron beam, or ultraviolet light) on the substrate (while Irradiation), and the radical polymerization process is completed. Although this method does not provide a uniform graft chain, it can be applied to a variety of substrates.

314314.ptd Page 19, 20031717 V. Description of the invention (11) _ By using ion exchangers 40 each made of a non-woven cloth (a liquid can flow therethrough and having an anion exchange group or a cation exchange group) 6 2a, 6 2b, 6 2c, it is possible to perform an ion exchange reaction between the ions of the liquid and the ion exchange groups of the ion exchanger. When each of the stacks 62 a, 62 b, and 6 2 c of the ion exchanger 40 has only one of an anion-exchange group and a cation-exchange group, materials that can be electrolyzed are limited, and may be formed due to polarity. Impurities. To solve this problem, the anion exchanger and the cation exchanger may be overlapped, or each of the stacks 62a, 62b, and 6 2 c of the ion exchanger 40 may have both an anion exchanger and a cation exchanger. This can expand the range of materials to be processed, and can suppress the formation of impurities. Furthermore, a multilayer structure (such as a non-woven fabric, a knitted fabric, and a porous film) composed of a stack of ion exchange materials is used to make the ion exchanger 40, so as to increase the total ion exchange capacity of the ion exchanger 40, by This suppresses the formation of oxides during processing such as copper removal (milling) to avoid negatively affecting the processing rate. In this regard, during the removal process, when the total ion exchange capacity of the ion exchanger 40 is less than the number of copper ions accepted by the ion exchanger 40, oxides are inevitably formed in the ion exchanger 40. On the surface or inside, this will negatively affect the processing rate •. Therefore, the formation of oxides is affected by the ion exchange capacity of the ion exchanger, and copper ions exceeding the capacity will form oxides. Therefore, a multi-layer ion exchanger composed of a stack of ion-exchange materials (ion-exchange materials having an increased total ion-exchange capacity) can be used as an ion exchanger, and the formation of oxides can be effectively suppressed.

314314.ptd Page 20 200301717 V. Description of the Invention (12) The preferred method is that the ion exchanger 40 has water permeability and water absorption, and hopes that at least the material of the workpiece has high hardness and good surface flatness. For example, as a CMP polishing pad, a commercially available foamed polyurethane `` IC 1 0 0 0〃 '' (manufactured by Rode 1) is generally used. 1 C 1 0 0 0 is quite hard and has excellent abrasion resistance. By providing a plurality of through holes, the product can be used as the material of each of the laminates of the ion exchanger 40, so that holes can be provided in the resin plate, so that the plate has the water permeability required for the ion exchanger 40, And hope that the material properties have `` water absorption '' is taken for granted. According to this embodiment, a plurality of fan-shaped electrode plates 64 are arranged in the electrode portion 36 in the peripheral direction, and the cathode and anode of the power source 68 are alternately connected to the electrode plate 64 through the slip ring 66. The electrode plate 6 4 connected to the cathode of the power source 6 8 becomes the processing electrode 32, and the electrode plate 6 4 connected to the anode of the power source 6 8 becomes the feed electrode 34. This is applied to processing such as copper because electrolytic processing of copper is performed on the cathode side. Depending on the material to be processed, the cathode side can be the feed electrode and the anode side can be the processing electrode. More specifically, when the material to be processed is copper, molybdenum, iron, or the like, the electrolytic processing is performed on the cathode side. Therefore, the electrode plate 64 connected to the cathode of the power source 6 8 should be the processed electrode 3 2 and connected to The anode electrode plate 6 4 should be the feeding electrode 34. On the other hand, in the case of aluminum, silicon, or the like, electrolytic processing is performed on the anode side. Therefore, the electrode plate connected to the anode of the power supply should be a processing electrode, and the electrode plate connected to the cathode should be a feed electrode. Therefore, by arranging the processing electrodes 32 and the feeding electrodes 34 separately and staggered in the peripheral direction of the electrode portion 36, there is no need to fix the feeding portion to supply power to the substrate conductive film (part to be processed) , And available in the entire substrate

314314.ptd Page 21 200301717 V. Description of the invention (13) Finished on the surface. In addition, by changing the positive electrode and the negative electrode in a pulsed or staggered manner, the electrolytic product can be decomposed, and the flatness of the processed surface can be improved by repeating the process several times. Regarding the processing electrode 32 and the feeding electrode 34, the oxidation or decomposition of the processing electrode 32 and the feeding electrode due to the electrolytic reaction is usually a problem. In view of this, the preferred method is to use carbon, which is relatively inactive. Noble metal, conductive oxide or conductive ceramic is used as the substrate of the feeding electrode 34, instead of using a metal or metal compound widely used as an electrode. The noble metal-based electrode may be obtained, for example, by plating or coating platinum or iridium on a titanium electrode, and then sintering the coated electrode at a high temperature to stabilize and strengthen the electrode. Ceramic products are usually obtained by heat-treating inorganic raw materials. Ceramic products with various properties are made from various raw materials including metal oxides, carbides, nitrides and non-metals. These raw materials include conductive materials. Ceramics. When the electrode is oxidized, the value of the resistivity 4 usually increases, resulting in an increase in the applied voltage. However, by protecting the electrode surface with a non-oxidizing material such as a tumbler or a conductive oxide such as an oxidized surface, it is possible to avoid a decrease in conductivity due to oxidation of the electrode substrate. The pure water nozzle 7 0 is a pure water supply unit for supplying pure water or ultrapure water to a space between the substrate W held by the substrate holding base 30 and the lowered electrode tip 38. The pure water nozzle 7 0 is disposed above the substrate holder 30, so that pure water or ultrapure water can be supplied to the ion exchanger 40. Here, pure water means water having a conductivity of not more than 10 // S / crn, while ultrapure water means water having a conductivity of not more than 0.1 " S / cm. The conductivity of the present invention means 25 ° C, 1 atmosphere

II Which painting? Ϊ́314314.ptd Page 22 200301717 V. Description of the invention (14) (a t m) Conductivity. In addition to pure water or ultrapure water, liquids or any electrolytic solution with a conductivity of not more than 500 // S / cm can also be used. By supplying the liquid during processing, processing instability factors such as processed products and dissolved gases can be removed, and processing can be performed uniformly with good reproducibility. The electrolytic processing device is provided with a numerical controller 7 2 for performing numerical control of the driving part, that is, a motor (first driving part) 4 4, a motor (second driving part) 5 6, and a motor (third driving part) 6 0, so that the substrate W and the processing electrode 32, which face each other and are held by the substrate fixing base 30, can be relatively moved. The motors (drive parts) 44, 56, 6 0 are therefore servo motors that can be numerically controlled, and the rotation angles and rotation speeds of these motors (drive parts) 4, 4, 6, 6, 0 are derived from the numerical controller 7 2 The output signal is controlled numerically. According to this embodiment, when the current flowing between the processing electrode 32 and the feeding electrode 34 is a constant value and the electrolytic processing is performed, the numerical controller 7 2 performs numerical control: by the motor (first driving section) 4 4 The control is the rotation speed of the substrate W held by the substrate holding base 30; the horizontal movement speed of the electrode head 38 controlled by the motor (second driving part) 56 rotating the rotating arm 48; and by The motor (third driving part) 60 controls the rotation speed of the electrode head 38. An example of numerical control will now be described with reference to FIGS. 2 and 3. First, as shown in Fig. 2, the outer shape of the substrate (workpiece) before processing is measured. Specifically, each coordinate point of the external shape before processing is measured in an XYZ coordinate system (where the Z axis system is orthogonal to the XY plane as a reference plane), and the measured shape data before processing is input into numerical control.器 7 2。 7 in the device. In addition, regarding the coordinate points (X, y, z 〇) of the external shape before processing,

314314.ptd Page 23 200301717 V. Description of the invention (15) The phase is the coordinate point (X, y, ζ) is also input to the numerical controller 7 2 as the desired shape information. In addition, such as the shape and processing rate of the unit The processing profile data (transmission speed of each motor control signal pulse) is input to the numerical controller 7 2 in advance or at any time. When the current flow between the processing electrode 3 2 and the feeding electrode 34 is controlled to a fixed value, In electrolytic processing, the processing rate is fixed so that the processing amount is determined by the product of the current value and the processing time. Therefore, the current flowing between the processing electrode 32 and the feed electrode 34 is controlled to a constant value. Only by controlling the processing time (that is, the period φ when the substrate W and the processing electrode 32 face each other) by a numerical value, in order to cause the electrolytic processing phenomenon (dwell time), the desired processing with a high-precision appearance can be obtained. The shape of the substrate. Therefore, according to the present embodiment, the processing of each coordinate point in the Z direction depends on the data input in the numerical controller 72. According to the processing amount Z2, each block is determined. Point: the rotation speed of the substrate W held by the substrate holder 30 is controlled by the motor (first driving section) 44; the rotating arm 4 8 is rotated by the motor (second driving section) 5 6 Control the horizontal movement speed of the electrode head 38; and the rotation speed of the electrode head 38 controlled by the motor (third driving section) 60, and input a signal to the motor (driving section) 4 4, 5 6, 6 0 In order to perform numerical control on the motor (driving unit) 4 4, 5 6, 6 0. Next, the electrolytic addition process performed by the electrolytic processing apparatus will be explained. First, the substrate fixing base 30 is attracted and Hold the substrate W 'and move the electrode head 3 8 to the substrate W held by the substrate holder 30 by rotating 1 arm 4 8

314314.ptd Page 24 200301717 Five invention descriptions (16) — square machining position, where ^ is read as a conductor film (to be added :: W is the life position by actuation of the motor 50 as shown in Figure 8B) Substrate w of the copper film 6. The potion is mounted on the electrode part of the electrode head 38. Shuo 3 8 descends for vertical movement. ^ The base held by the fixed seat 30. The ion exchanger on the lower surface 4 times. = ^ The surface is in contact with or close to it, and it is the substrate, and at the same time, the processing electrode 32: two: force: the working electrode 32 and the feeding electrode 34 are set to a fixed value, and the substrate is fixed between the cladding electrode 34 The electric current flowing to the person will rotate the rotating arm 48, and the seat 30 and the electrode head 38 will rotate. At this time, the electrode tip 38 is horizontally moved by being fixed on the substrate. The pure water is supplied to the substrate W and the pure water nozzle 70 above the electrode, and the pure water or ultra-filled is processed between the processing electrode 3 2 and the feed belt 38, thereby forming pure water or ultra-pure water on the substrate. The space between the conducting W pole 34 on W and the substrate w. The electrolytic processing of the hydrogen ion stub ′ (copper film 6) in the son-in- father converter 40 is performed by ionization, more specifically, by ions. When the pure water or ultrapure hydrolysis is replaced, the codon of the catalytic reaction in 40 transfers milk ions and hydrogen ions near the processing electrode 32. Hydrogen ion reacts with the copper film β of the substrate W, and becomes dioxy group, and the hydroxyl group will be processed. In order to remove (grind) the copper film 6 at the feeding electrode 34; the gas-permeable ionic film is strongly acidic: the male barrier is outside, and the hydrogen barrier can be used outside, and the ion-exchange membrane 62 can be used. Produced by the rotation of) and = the flow of ultrapure water (from the electrode part 36 to 40: foot: pure water or ultrapure water can flow into the ion exchange, and the water in the foot is supplied to the functional group (with strong acidity) Yang

200301717 V. Description of the invention (17) The ion exchanger of ion exchange group is a continuous acid group in order to increase the number of dissociated water molecules, and the conductor film (copper film 6) and hydroxide ion The processing product (including gas) formed by the reaction between (or hydroxyl groups) can be removed by water flow, thereby improving processing efficiency. Therefore, the flow of pure water or ultrapure water is necessary, and the water flow is expected to be stable and uniform. The stability and uniformity of the water flow will lead to the stability, qualitative and uniformity of ion supply and removal of processed products, and then will lead to the stability and uniformity of processing. By making an ion exchanger 40, which is composed of a laminated structure of a multilayer structure, the total ion exchange capacity of the ion exchanger (laminate) 40 can be increased, thereby avoiding the reaction products (oxides of the electrolytic reaction) And ions) accumulated in the ion exchanger 40 exceeds the accumulated capacity of the lamination. In this regard, if the reaction products accumulated in the laminate exceed the cumulative capacity, the accumulated products may change their form, and the converted products may negatively affect the processing rate and its distribution. Furthermore, the flatness of the substrate processing surface can be improved by using an ion exchanger 40 having high hardness, good surface flatness, or both. Pre-processed profile data, desired profile data, and unit-processed profile data are input into the numerical controller 7 2 in advance for electrolytic processing and numerical control at the same time: the substrate holder 3 controlled by the motor (first drive section) 4 4 The rotation speed of the called substrate W; the horizontal movement speed of the electrode head 38 controlled by the motor (second driving part) 5 6 to rotate the rotating arm 4 8; and by the "motor (third driving part) 6 0 while controlling the rotation speed of the electrode tip 38. During the electrolytic processing, when the relative movement between the substrate W and the processing electrode 32 is numerically controlled, it will be between the processing electrode 32 and the feeding electrode 34.

314314.ptd Page 26 200301717 V. Description of the invention (18) The flowing current is controlled at a fixed value, thereby fixing the processing rate. The electrolytic processing can form the desired shape of the processing substrate W (workpiece) with a high-precision shape. After the electrolytic processing is completed, the power supply 68 is turned off, the rotation of the substrate holder 30 and the electrode head 38 is stopped, and the rotation of the rotation arm 48 is stopped. Then, the electrode tip 3 8 ′ is raised and the processed substrate W held by the substrate holder 30 is sent to the next process. This embodiment discloses the state of supplying pure water (preferably ultrapure water) to the space between the electrode portion 36 and the substrate W. In the electrolytic processing, the use of pure water or ultra-pure water containing no electrolyte can prevent additional impurities such as electrolytes from sticking to and remaining on the surface of the substrate W. Furthermore, the copper ions or the like dissolved during the electrolytic processing are immediately captured by the ion exchanger 40 through an ion exchange reaction, which can prevent the dissolved copper ions or the like from re-precipitating out of the substrate W. In other parts, or to prevent the dissolved copper ions or the like from oxidizing to become particles that contaminate the surface of the substrate W. Ultrapure water has high resistivity, so it is difficult for current to flow through ultrapure water. By reducing the distance between the electrode and the workpiece, or by placing the ion exchanger between the electrode and the workpiece, the resistivity is reduced. Furthermore, when one electrolytic solution is used with multiple electrolytic solutions, the resistivity can be further reduced and power consumption can be reduced. When an electrolytic solution is used for electrolytic processing, the area of the workpiece to be processed is slightly wider than the area of the processed electrode. On the other hand, in the case where ultrapure water is used in combination with the ion exchanger, since almost no current flows through the ultrapure water, the electric machining is performed only in the area of the workpiece equal to the area of the processing electrode and the ion exchanger.

314314.ptd Page 27 20031717 V. Description of the invention (19) _ An electrolytic solution obtained by adding an electrolyte to pure water or ultrapure water can be used instead of pure water or ultrapure water. The use of this electrolytic solution can further reduce Resistivity and reduced power consumption. Neutral salt solutions such as vaporized sodium or sodium sulfate, acid solutions such as hydrogen chloride or sulfuric acid, or test solutions such as ammonia can be used as electrolytic solutions, and these solutions can be selectively used depending on the properties of the workpiece. When the electrolytic solution is used, it is preferable to provide a slight distance between the substrate W and the ion exchanger 40 so that the substrate W and the ion exchanger 1 40 do not contact each other. 1 Furthermore, a liquid obtained by adding a surfactant or the like to pure water # ultra-pure water may be used instead of pure water or ultra-pure water, wherein the liquid has a content of not more than 500 // S / cm The conductivity is preferably not more than 50 // S / cm, and not more than 0 · 1 // S / cm (resistivity not less than 10 megaΩ · cm) is more preferable. Because the surfactant is present in pure water or ultrapure water, the liquid can form a thin layer on the interface between the substrate W and the ion exchanger 40, and the thin layer is used to uniformly suppress ion migration, thereby Adjust the ion exchange (metal dissolution) concentration to improve the flatness of the processed surface. The concentration of surfactant is expected not to exceed 100 ppm. When the value of the conductivity is too high, the current efficiency will decrease and the processing rate will decrease. The desired processing rate can be obtained by using a liquid with a conductivity of not more than 5 0 0 // S / c. The conductivity of the liquid is preferably not more than 50 // S / cm, and not more than 0.1 // S / cm. Better. -According to this embodiment, by placing the ion exchanger 40 between the substrate W, the processing electrode 32, and the feed electrode 34, a considerable processing rate can be increased. In this regard, electrochemical processing using ultrapure water

314314.ptd page 28 200301717 V. Description of the invention (20) The chemical interaction between the hydroxide ion and the processing material is completed. However, under normal temperature and normal pressure conditions, the number of hydroxide ions as reactants in ultrapure water is as small as 10 -7mo 1 / L, so that the removal processing efficiency can be affected by reactions other than the removal processing reaction ( Such as oxide film formation reactions). Therefore, it is necessary to add hydroxide ions for efficient removal processing. The method for increasing hydroxide ions is to increase the dissociation reaction of ultrapure water by using a catalytic material, and an ion exchanger can effectively act as the catalytic material. More specifically, the activation energy required for the dissociation reaction of water molecules is reduced by the interaction between the functional group in the ion exchanger and the water molecules, thereby promoting hydrolysis to occur to thereby increase the processing rate. Furthermore, according to this embodiment, during the electrolytic processing, the ion exchanger 40 is brought into contact with or approached the substrate W. When the ion exchanger 40 is positioned close to the substrate W, the resistivity becomes large to some extent (depending on the distance therebetween), so a slightly larger voltage is required to provide the necessary current density. However, on the other hand, due to the non-contact property, it is easy to form a pure water flow or an ultrapure water flow along the surface of the substrate W, so that the reaction products formed on the surface of the substrate can be efficiently removed. In a state where the ion exchanger 40 is in contact with the substrate W, the resistivity becomes very small, so that only a small voltage needs to be applied, thereby reducing power consumption. If the voltage is increased to increase the current density in order to increase the processing rate, a discharge may occur when the resistivity between the electrode and the substrate (workpiece) is large. The occurrence of electric discharge will cause # pits (e t c h p i t) on the surface of the workpiece, so it is impossible to form a uniform and flat machining surface. In contrast, since the resistivity is small when the ion exchanger 40 is in contact with the substrate W, it is possible to

314314.ptd Page 29 200301717 V. Description of the invention (21) Avoid discharge. Fig. 4 shows an arrangement according to a second embodiment of the present invention. The substrate fixing base 3 and the contact fixing plate 80 of the electrolytic processing apparatus. As a plurality of directions of the feeding electrode: = = Attached to the contact fixing plate 80 at a specific pitch. Again = = ㈣ 'instead of the electrode used in the embodiment of Fig. I = electrode 84 is connected to the cathode of the power source 68 via the slip ring 86, and the contact (feeding electrode) 8 2 The connection to the thunder tone R s ^ is the same as the device shown in Fig. 丨 and is connected to the & Other structures y: According to this embodiment, 'when the substrate w is fixed by the substrate a (a, 30, electric electrodes) 82 are deposited on the surface of the substrate w as shown in FIG. 8B. (As a material to be processed) Contact, electrolytic processing can be performed in the same manner as the first two methods. Therefore, the electrode tip 38 is lowered, and a value of current is applied from the power source 68 to the processing electrode 84 and the contact (feeding electrode), and the substrate holder 30 and the electrode tip 38 are rotated at the same time. 1'Asia rotates the rotating arm 4 8 to move the electrode head 3 8 horizontally. On the same day, the pure water nozzle 70 supplied pure water or ultrapure water between the substrate f and the processing electrode 8 4 ', thus completing the electrolysis of the conductive film (copper film 6) of the substrate ... (the second is as previously disclosed) Processing example, generally, before electrolytic processing, input the data of Jiaqi Seven Foreign Affairs Office, Hope Shape Materials Department and unit processing shape data into the numerical controller 7 2 for numerical control: by the motor (the first driving part) 4 4 It is only the rotation speed of the substrate W held by the substrate holder 30; the electrode head controlled by rotating the rotating arm 4 8 by a horse driving unit 5 6

314314.ptd Page 30 200301717 V. Explanation of the invention (22) ^ ^ ---- 3 8 horizontal movement speed; and the rotation speed of the electrode head 38 controlled by the motor (the second driving part) 60 . In the batch of Ding Shui, # 〆 从 & II, Meng Gu Gu 1, the electrolytic processing performed in the 3 L system can form the desired shape of the processed substrate w with the same shape. Fig. 5 shows an electrolytic processing device according to a third embodiment of the present invention. The electrolytic processing device includes a substrate holder 100 for attracting and holding a substrate, and Naiyang + human et gate-L and configuration. A barrel-shaped or column-shaped force sigma electrode 109 above the substrate holder 100. , Υ ^ processing electrode 1 0 2 is coupled to a horizontally extending screw that can rotate and can move vertically, the free end of π & shaft 104, and the ion exchanger 1 〇6 is tightly mounted on the processing electrode 1 〇 ^ 1 υ ZZ On the outer peripheral surface, the substrate holder 100 and the processing electrode 102 are arranged in a processing tank (not shown) filled with a fluid such as ultra-pure water or pure water, which is: $ #, Riding the substrate holder 100 and processing electrode 1 〇2 submerged in the fluid. The substrate holder 100 〇_ 马 人 你 祖 ^ P ^ ^, Ί ΠδΑ,,. Ό 欢 对 者 Z The upper surface of the rotating limb 108 which rotates in the direction of axis 0, the rotating body 108 is mounted on the XY platform 118. It contains: x base ιι2, driven by a motor ιο: brother.) And move in the X direction Θ on the θ + phase 1 plate w and the processing electrode 102 relative movement in the x direction, and the activation of the γ base 116 second drive unit) in h Α μ The substrate w held by the fixed base 100 and the processing t are relative movements of the substrate 100. The electrode 102 is fed in the Y direction by the pen source 1 2 0 Skudai electrode extending to 102, and the line extending from the anode: associated with the machining electrode connected to the feeding line electrode 122 is electrically connected to the electrical Ϊ "electrode 122, wherein ♦ (i.e., as the shape shown in Figure 8B

200301717 V. Description of the invention (23) The copper film 6) is formed in the substrate W and supplies electric power to the electric conductor. The processing tank is provided with a fluid nozzle as a fluid supply section for supplying a fluid such as pure water or ultrapure water to the processing tank. The electrolytic processing device is provided with a numerical controller 1 2 4 for performing numerical control of a driving part, that is, a motor 1 1 0 (a first driving part) and a motor 1 1 4 (a second driving part). These motors 1 1 0, 1 1 4 make the substrates facing each other the substrate, and the substrate W held by the fixed seat 100 and the processing electrode 102 can move relative to each other. The motor (drive unit) 1 1 0, 1 1 4 is a servo motor that can perform numerical control, and the rotation angle and speed of these motors 1 1 0, 1 1 4 are derived from the number φ controller 1 2 4 output signal for numerical control. An example of numerical control will now be described with reference to FIG. 6. First, as shown in Figure 2, by measuring each coordinate point of the shape before processing in the XY Z coordinate system (where the Z axis system is orthogonal to the Y plane as a reference plane), Substrate (workpiece) shape. Enter the measured profile data Λ before processing into the numerical controller 1 2 4. In addition, regarding the coordinate points (X, y, ζ 〇) of the external shape before processing, the corresponding coordinate points (X, y, ζ 〇) of the shape after processing are also input to the numerical controller 1 2 4. In addition, such as The unit processing profile data (transmission speed of each motor control signal pulse) regarding the profile and processing rate are input to the numerical controller Zhao 4 in advance or at an arbitrary time. According to this embodiment, the processing amount of each coordinate point in the Z direction Z ## is determined by inputting data from the numerical controller 1 24. According to the processing amount Z2, it is determined that the motor (first driving section) 1 1 0 and the motor (second driving section) 1 1 4 will be While the substrate W held by the substrate holder 100 is stopped, the signal

314314.ptd Page 32 200301717 V. Description of the invention (24) Enter the motor (drive part) 1 1 0, 11 4 in order to perform numerical control on the motor 1 1 0, 11 4. According to this embodiment, a substrate W having a copper film 6 (as a conductive film (part to be processed)) on the surface as shown in FIG. 8B is attracted and held by the substrate holder 100, and is mounted on the processing electrode The ion exchanger 1 0 6 on the surface of 102 is close to or in contact with the surface W of the substrate (upper surface). Then, a fixed value of current is supplied from the power source 120 to the processing electrode 102 and the feeding electrode 12 and the processing electrode 102 is rotated at the same time to perform electrolytic processing. During electrolytic processing, step motion is performed by the XY stage 1 1 8, that is, the substrate W is repeatedly moved and stopped in the X or Y direction. For this operation, as described earlier, the pre-processing profile data, the desired profile data, and the unit processing profile data are entered in advance by the numerical controller 1 2 4 by the motor (first drive section) 1 1 0 and the motor (section 2 driving parts) 1 1 4 and numerically control the stop time of the substrate W held by the substrate fixing seat 100, and the electrolytic processing by the controlled relative step motion can form a high-precision shape. I want to process the shape of the substrate. The `` relative stepping motion '' referred to herein means that one or both of the substrate W and the processing electrode 102 are moved to cause the processing electrode 102 to repeatedly move on the substrate W at a specific distance and Stopped relative motion. Fig. 7 shows an electrolytic processing apparatus according to a fourth embodiment of the present invention. This embodiment differs from the third embodiment shown in Fig. 5 in that a spherical or elliptical processing electrode 1 0 2 a is used. When the processing electrode 1 0 2 a is lowered, the ion exchanger 1 0 6 a mounted on the surface of the processing electrode 1 0 2 a and the substrate

314314.ptd Page 33 200301717 V. Description of the invention (25) W contact. When the ion exchanger contacts the substrate W in this manner, the processing electrode 102a is rotated. The other structures are the same as those of the third embodiment. According to this embodiment, the area of the processing portion (point) is small, so that ultrapure water or pure water can be easily supplied around the processing portion, and stable processing can be performed. According to the previously disclosed embodiment, the driving part can make the v substrate and the processing electrode held by the substrate holder relative to each other, and perform the value under the condition that the current flowing between the processing electrode and the feed-electrode is controlled at a fixed value. control. 'However, it is also possible to control the voltage φ applied between the processing electrode and the feeding electrode to a fixed value, and the relationship between voltage and current determines the current flowing between the processing electrode and the feeding electrode, and according to this The driving current is digitally controlled by the determined current. The measurement of the shape of the substrate (workpiece) can be performed not only before processing, but also at any time during the processing. In this section, there may be a case where the processing time is different from the predetermined processing time, and this difference may reduce the accuracy of the shape of the finished processed substrate. By making as many substrate measurements as possible during processing, the reduction in accuracy can be eliminated or reduced. Therefore, increasing the number of measurements during machining usually improves machining accuracy. As mentioned above, the present invention is able to compare the external shape of the workpiece before or during processing with the desired shape of the workpiece after processing and determine the processing amount (equivalent to the coordinate difference between the two shapes): Processing amount), input numerical controller, and complete the numerical control of the driving part according to the inputted data, wherein the driving part is used for relative movement of the workpiece and the processing electrode facing each other and held by the fixed seat, in Under the numerical control

314314.ptd Page 34 200301717 V. Description of the Invention (26) Electrolytic machining can be performed to form the shape of the workpiece with high precision. Although specific preferred embodiments of the invention have been disclosed and described in detail, it should be understood that various changes and modifications can be made to the invention without departing from the scope of the appended patent applications. Industrial Applicability The present invention relates to an electrolytic processing apparatus and method for processing a conductive material on a surface of a substrate (such as a semiconductor wafer) or for removing impurities adhering to the surface of a substrate.

314314.ptd Page 35 200301717 Figure-Simplified Description [Simplified Illustration] Figure 1 is a front view of a longitudinal section of an electrolytic processing device according to a first embodiment of the present invention; Figure 2 is a diagram illustrating the force of a workpiece Schematic diagram of the relationship between the front shape and the shape after the machining; Figure 3 is a block diagram illustrating an example of numerical control performed by the electrolytic processing device of Figure 1. Figure 4 is an electrolysis according to the second embodiment of the present invention. Front view of a 'longitudinal section' of the processing apparatus; Figure 5 is a schematic perspective view of an electrolytic processing apparatus according to a third embodiment of the present invention, and Figure 6 illustrates an example of numerical control using the electrolytic processing apparatus of Figure 5 Block diagram; FIG. 7 is a schematic perspective view of an electrolytic processing apparatus according to a fourth embodiment of the present invention, and FIGS. 8A to 8C are diagrams illustrating the intent of an example of forming a copper interconnection line in order of process steps, and Figure 9 illustrates Schematic diagram of the principle of electrolytic processing using ion converters 〇 W lc a conductive layer 1 semiconductor substrate • 2 insulating film 3 contact hole 4 trench 5 barrier layer • 6 copper film 7 seed layer

314314.ptd Page 36 200301717

Brief description of the drawing 10 Workpiece 10a Atom 12a, 12b, 40,.] _ Oe i, 106a Ion exchanger 14 Orifice electrode 16, 34, 122 Feed electrode 17, 68, 120 Power supply 18 Liquid 19 Liquid supply part 20 Water molecule 22 Hydroxide ion 24 Hydrogen ion 26 Reaction product 30 Substrate holder 32 Orifice electrode 36 Electrode section 38 Electrode head 42 Support shaft 44, 50 > 56 ^ 1 1 (114 motor 46, 58 timing belt 48 rotation Arm 52 Ball screw 54 Hollow rotating shaft 60 Hollow motor 6 2a, 62b Strongly acidic cation exchange fiber 62c Strongly acidic cation exchange film 64 Sector electrode plate 6 6 '86 Collector ring 70 Pure water nozzle 72 Numerical controller 80 Contact fixing plate 82 contacts 84 processed electrodes 100 substrate holder 314314.ptd page 37 200301717

314314.ptd Page 38

Claims (1)

200301717 VI. Application for patent scope 1. An electrolytic processing device, comprising: a fixing base for detachably holding a workpiece; a processing electrode that can approach or contact the workpiece held by the fixing base; a feeding electrode for Supplying power to the workpiece held by the fixed base; an ion exchanger arranged in at least one space between a space between the workpiece and the processing electrode and a space between the workpiece and the feeding electrode; a fluid supply unit, For supplying a fluid between the workpiece in which the ion exchanger is present and at least one of the processing electrode and the feeding electrode; a power source for applying a voltage between the processing electrode and the feeding electrode A driving section for making the workpiece and the processing electrode facing each other and held by the fixed base to perform relative movement; and a numerical controller for performing numerical control of the driving section. 2. The electrolytic processing device according to item 1 of the patent application scope, wherein the power supply supplies a current or voltage controlled at a fixed value between the processing electrode and the feeding electrode. 3. For the electrolytic processing device according to item 2 of the patent application scope, wherein the numerical controller uses the driving unit to numerically control the relative movement speed between the workpiece and the processing electrode held by the fixed base. 4. For the electrolytic processing device in the scope of patent application, the numerical control 314314.ptd Page 39 200301717 VI. Patent application scope The controller uses the driving unit to numerically control the stop time of the relative step motion between the workpiece and the processing electrode held by the fixed seat. 5. An electrolytic processing method, comprising: providing a processing electrode, a feeding electrode, and an ion exchanger, the ion exchanger being arranged in a space between a workpiece held by a fixed base and the processing electrode, and the workpiece and the feeding electrode In at least one of the interspaces; when power is supplied to the workpiece by the feeding electrode, the processing electric φ pole can approach or contact the workpiece held by the fixed base; supply fluid to where the workpiece exists A space between the workpiece of the ion exchanger and at least one of the processing electrode and the feeding electrode; applying a voltage between the processing electrode and the feeding electrode; and controlling the movement numerically with a numerical controller In the case, the workpiece and the processing electrode facing each other and held by the fixing base can be relatively moved. 6. The electrolytic processing method according to item 5 of the patent application scope, wherein a current or voltage controlled at a fixed value is supplied between the processing electrode and the feeding electrode. 7. The electrolytic processing method according to item 6 of the patent application scope includes: measuring the shape of the workpiece before and / or during processing; entering the coordinate data of the measured outer shape and the desired shape of the workpiece after processing into the In a numerical controller; and 314314.ptd Page 40 200301717 VI. Application for Patent Range According to the coordinate difference between the measured shape and the desired shape, numerical control of the relative movement speed between the workpiece and the processing electrode held by the fixed base . 8. The electrolytic processing method according to item 6 of the scope of patent application, comprising: measuring the shape of the workpiece before and / or during processing; entering the coordinate data of the measured outer shape and the desired shape of the workpiece after processing into the A numerical controller; and numerically controlling a stop time in a relative step motion between the workpiece and the processing electrode held by the fixed base according to a coordinate difference between the measured shape and the desired shape . 314314.ptd Page 41