JP2008524434A - Flattening method and flattening apparatus - Google Patents

Abstract

In the planarization method, even if an initial step is formed on the surface of the metal film as the wiring material, the metal film can be polished flatly over the entire surface at a sufficient processing speed. In this flattening method, when a metal film surface having an initial step formed on a workpiece is processed and flattened, only the concave portion forming the initial step on the metal film surface is coated with a solid or paste-like coating material. Then, the metal film surface is processed by electrolytic processing without using an abrasive.

Description

  The present invention relates to a planarization method and a planarization apparatus, and more particularly, a wiring material comprising a metal film such as a copper film formed on a surface of a fine wiring recess provided on the surface of a substrate such as a semiconductor wafer. The present invention relates to a planarization method and a planarization apparatus used for processing and planarizing a surface of a (conductive film).

  In recent years, as a wiring material for forming a circuit on a substrate such as a semiconductor wafer, a movement of using copper having a low electrical resistivity and a high electromigration resistance in place of aluminum or an aluminum alloy has become prominent. The copper wiring is generally formed by embedding copper in a fine wiring recess provided on the surface of the substrate. There are methods such as chemical vapor deposition (CVD), sputtering, and plating as methods for forming this copper wiring, but in any case, copper is formed on almost the entire surface of the substrate, and unnecessary by polishing. Copper is removed.

1A to 1C show a manufacturing example of this type of copper wiring board W in the order of steps. First, as shown in FIG. 1A, an insulating film 2 such as an oxide film made of SiO ₂ or a low-k material film is deposited on a conductive layer 1a on a semiconductor substrate 1 on which a semiconductor element is formed. Inside the film 2, a contact hole 3 and a trench 4 are formed as wiring recesses by lithography / etching technique. A barrier film 5 made of TaN or the like is further formed thereon, and a seed layer 7 as a power feeding layer for electrolytic plating is formed on the barrier film 5 by sputtering or CVD.

  Then, copper plating is performed on the surface of the substrate W, thereby filling the contact holes 3 and the trenches 4 of the substrate W with copper as shown in FIG. 1B and depositing a copper film 6 on the insulating film 2. Thereafter, the surface of the substrate W is polished by chemical mechanical polishing (CMP) or the like, the copper film 6, the seed layer 7 and the barrier film 5 on the insulating film 2 are removed, and the contact hole 3 and the trench 4 are filled. The surface of the copper film 6 and the surface of the insulating film 2 are made substantially flush. Thereby, as shown in FIG. 1C, a wiring made of the copper film 6 is formed inside the insulating film 2.

  In recent years, as the miniaturization and high precision have progressed in the components of all devices, and the manufacturing in the sub-micron region has become common, the influence of the processing method itself on the characteristics of the material has been increasing. Under such circumstances, the machining method in which the tool removes the workpiece while physically destroying it, as in conventional machining, because many defects are generated in the workpiece by machining. As a result, the properties of the workpiece are deteriorated. Therefore, it becomes important how processing can be performed without deteriorating the characteristics of the material.

  Special processing methods developed as means for solving this problem include chemical polishing, electrolytic processing, and electrolytic polishing. In contrast to conventional physical processing, these processing methods perform removal processing and the like by causing a chemical dissolution reaction. Therefore, in these processing methods, defects such as work-affected layers and dislocations due to plastic deformation do not occur, and the problem of performing processing without impairing the above-mentioned material characteristics is achieved.

  For example, chemical mechanical polishing (CMP) generally requires a fairly complicated operation, is complicated to control, and has a considerably long processing time. Furthermore, not only is it necessary to sufficiently perform post-cleaning of the substrate after polishing, but there are also problems such as a large load for draining the slurry and cleaning liquid. Therefore, there is a strong demand for omitting CMP itself or reducing this load.

  As means for solving such problems, an ion exchanger as a processing member is disposed between the electrode and the workpiece, and a liquid having a large electric resistance such as pure water or ultrapure water is used as an electrolytic solution. There has been proposed electrolytic processing that eliminates mechanical stress applied to the workpiece by performing the processing and that is easy for post-cleaning (see, for example, JP-A-2003-145354).

  For example, in the case of a substrate on which a copper film as a wiring material is formed on the surface in order to form a copper wiring, as shown in FIG. 2A, a large number of trenches 4 provided in the insulating film 2 at a predetermined pitch. A pattern portion P in which a copper film (metal film) 6 is deposited on the surface of the insulating film 2 while copper is embedded therein, and a copper film 6 on the surface of the insulating film 2 so as to surround the periphery of the pattern portion P. A deposited field portion F is generally present. Various initial steps are formed in the pattern portion P depending on the density of the wiring to be formed, the wiring width, and the like.

  When the surface of the copper film 6 is processed and flattened by electrolytic processing, the electric field strength between the electrode and the copper film 6 differs due to the initial step on the surface of the copper film 6. In particular, since the electrolytic strength is higher in the pattern portion P where the convex portions are concentrated than in the field portion F, reactive species ions (an ionic substance that promotes dissolution of the conductive film to be polished. For example, when the reactive conductive film is copper, hydroxylation is performed. The supply amount of the product ions is larger than that of the field portion F. Thereby, the processing speed of the copper film 6 in the pattern portion P becomes larger than the processing speed of the copper film 6 in the field portion F. Moreover, it is difficult to obtain a difference in the processing speed of the copper film 6 between the concave portion 6a and the convex portion 6b forming the step, and the concave portion 6a is also processed at substantially the same speed as the convex portion 6b. For this reason, as shown in FIGS. 2B and 2C, the initial step remains after being removed by processing, and it becomes difficult to flatten the surface of the copper film 6 over the entire surface. In addition, if the electrolytic processing is further continued, as shown in FIG. 2D, the copper buried in the trench 4 is processed and removed, the wiring capacity is reduced, and the wiring resistance is increased.

  For this reason, electrolytic processing of a workpiece such as the copper film 6 is performed using an electrolytic solution to which a surface film forming agent such as an oxidizing agent or a complexing agent is added. Thereby, by suppressing the electrolytic elution reaction in the concave portion 6a of the copper film 6, the processing speed of the copper film 6 in the concave portion 6a is made slower than the convex portion 6b, and the convex portion 6b is selectively processed, Flatness can be increased. However, in this case, if the applied voltage is increased in order to increase the processing speed, the effect of suppressing the electrolytic reaction by these films becomes insufficient, and sufficient level difference elimination ability cannot be obtained.

  Further, as described above, as a result of the polishing rate of the copper film 6 in the pattern portion P being higher than the polishing (processing) rate of the copper film 6 in the field portion F, as shown in FIGS. A phenomenon may occur in which the concave portion 9 is formed in the entire copper film 6 positioned. The size of the concave portion 9 is considerably large depending on the shape of the pattern portion P and the like, and it is difficult to flatten the entire copper film 6.

  For this reason, as shown in FIGS. 4A and 4B, the polishing rate of the copper film 6 in the pattern portion P of the copper film 6 is equal to the polishing rate of the copper film 6 in the field portion F. Thus, regardless of the presence of the pattern portion P and the field portion F, it is required to polish the surface of the copper film 6 flatly over the entire surface. Various attempts have been made to meet this demand, but it is generally quite difficult to make the polishing rate of the copper film 6 in the pattern portion P equal to the polishing rate of the copper film 6 in the field portion F.

  The present invention has been made in view of the above circumstances.For example, even if an initial step is formed on the surface of a metal film (conductive film) such as a copper film as a wiring material, the entire surface of the metal film is formed. In addition, it is an object of the present invention to provide a flattening method and a flattening apparatus that can perform flat polishing at a sufficient processing speed.

  In order to achieve the above object, the planarization method of the present invention forms the initial step on the surface of the metal film when the metal film surface having the initial step formed on the workpiece is processed and planarized. Only the recess is covered with a solid or paste-like coating material, and the surface of the metal film is processed by electrolytic processing without using an abrasive.

  According to this planarization method, the metal film surface is selectively processed by electrolytic processing while covering the recesses on the metal film surface with a coating material and suppressing the processing of the recesses, It can be flattened. Moreover, sufficient processing can be achieved by using a solid or paste-like material having high bonding strength with the metal film that does not separate from the metal film even when electrolytic processing is performed with an applied voltage of 10 V or more, for example. You can get speed.

  Although electrolytic processing may be performed using a normal electrolytic solution, it is desirable to perform electrolytic processing using ultrapure water, pure water, or a liquid having an electric conductivity of 500 μS / cm or less. Contamination on the surface of the workpiece can be greatly reduced, and processing of the waste liquid after processing is facilitated.

  In a preferred aspect of the present invention, the planarization method removes the coating material remaining on the surface of the metal film without being processed by electrolytic processing, and further processes the surface of the metal film.

  When the concave portion of the metal film surface is coated with a coating material and the metal film surface is processed by electrolytic processing while suppressing the processing of the metal film in the concave portion, for example, the covering member made of an insulating material is not completely removed on the metal film surface. May remain. In such a case, for example, the coating material is removed at the stage where the convex portion is eliminated and the coating material is exposed, and the metal film surface is further processed to obtain a flattened metal film surface without the coating material. Can do. Processing of the surface of the metal film after removing the coating material may be performed by electrolytic processing using, for example, an electrolytic solution or ultrapure water, or may be performed by an arbitrary method such as normal CMP.

The covering material is made of, for example, an insulating material having a resistivity of 10 ⁶ Ω · cm or more, or a conductive material having a resistivity of 10 ³ Ω · cm or less.

A metal coated with a coating material by using an insulating material having a resistivity of 10 ⁶ Ω · cm or more (conductivity of 1 μS / cm or less) as a coating material so that almost no current flows through the coating material. It is possible to prevent the electrolytic reaction from proceeding in the film recess. Thereby, the convex part of a metal film can be removed preferentially. Examples of the insulating material include a photoresist, a paint, an oil-based ink, and a quick-drying adhesive.

By using a conductive material with a resistivity of 10 ³ Ω · cm or less (conductivity of 10 ³ μS / cm or more) as the coating material, and allowing the current to flow through the coating material, an electrolytic reaction is also performed on the surface of the conductive material. Can be made to progress. Thereby, an electron current flows through the inside of the coating material and also into the metal film in the concave portion, the current density on the entire surface of the metal film can be made more uniform, and the metal film other than the coating portion can be processed uniformly. Examples of the conductive material include conductive paint, conductive ink, conductive adhesive, or conductive paste. These are those in which conductive particles such as metal fine particles and carbon are blended in a resin to provide conductivity, and the conductivity can be controlled by the blending amount of the conductive particles.

  The covering material made of an insulating material or a conductive material is preferably processed somewhat (slower than the metal film) by electrolytic processing.

  In a preferred aspect of the present invention, after the coating material is applied to the entire surface of the metal film, only the coating material located on the convex portion forming the initial step on the surface of the metal film is removed, and the metal is removed. Only the recesses forming the initial step on the film surface are covered with a coating material.

  For example, after applying oil-based ink or oil-based paint on the entire surface of the metal film, the oil-based ink on the surface of the metal film is wiped off with alcohol or thinner, or a resist is applied to the entire surface of the metal film and exposed and then developed. As a result, only the recesses that form the initial step on the surface of the metal film can be covered with the coating material.

In a preferred aspect of the present invention, the coating material is selectively applied to the recesses on the surface of the metal film, and only the recesses that form the initial steps on the surface of the metal film are covered with the coating material.
For example, by selectively applying ink only to the recesses on the surface of the metal film by the ink jet method, only the recesses that form the initial steps on the surface of the metal film can be covered with the coating material.

  In a preferred aspect of the present invention, a voltage is applied between a machining electrode close to the metal film of the workpiece and a power feeding electrode that feeds the metal film, and the workpiece on which the processing member exists and the workpiece A liquid is supplied between at least one of the processing electrode and the power supply electrode, and the workpiece and at least one of the processing electrode or the power supply electrode are relatively moved to process the surface of the metal film by the electrolytic processing. Do.

  A normal electrolytic solution may be used as the liquid, but it is desirable to use ultrapure water, pure water, or a liquid having an electric conductivity of 500 μS / cm or less. It can be greatly reduced, and processing of the waste liquid after processing becomes easy.

The processing member is preferably made of an ion exchanger or a material containing an ion exchanger.
By using an ion exchanger or a material containing an ion exchanger as a processing member, the surface of the metal film is promoted while promoting dissociation of water molecules in a liquid such as ultrapure water into hydroxide ions and hydrogen ions. Can be processed and flattened. A CMP pad, fixed abrasive pad, PVA sponge, or the like may be used as the processing member.

  In a preferred aspect of the present invention, a voltage is applied between a machining electrode close to the metal film of the workpiece and a feeding electrode that feeds the metal film, and the workpiece and the machining electrode or the feeding electrode are applied. A liquid is supplied between at least one of the two, and the workpiece and at least one of the processing electrode or the feeding electrode are relatively moved to process the surface of the metal film by the electrolytic processing.

  In a preferred aspect of the present invention, the metal film surface is processed by the electrolytic processing by bringing a contact member disposed on a side of the processing electrode and / or the feeding electrode into contact with the metal film surface of the workpiece. Do.

  In this way, by processing the surface of the metal film by electrolytic processing while bringing the contact member into contact with the surface of the metal film, it is possible to process (remove) the solid or paste-like coating material while adjusting the processing speed. As the contact member, for example, a CMP pad, a fixed abrasive pad, a PVA sponge, or the like can be used, and an ion exchanger or a material containing an ion exchanger may be used.

The planarizing apparatus of the present invention processes a surface of the metal film by a coating material processing apparatus that coats only a recess that forms an initial level difference on the surface of the metal film with a solid or paste-like coating material, and electrolytic processing without using an abrasive. An electrolytic processing apparatus.
The coating material processing apparatus includes, for example, a resist processing apparatus.

  In another planarization method of the present invention, in polishing and planarizing a metal film (conductive film) surface having a pattern part and a field part formed on a workpiece, the polishing rate of the metal film in the pattern part is increased. The first polishing of the metal film surface is performed in a state higher than the polishing rate of the metal film in the field portion, and the metal film in a state where the polishing rate of the metal film in the field portion is higher than the polishing rate of the metal film in the pattern portion. A second polishing of the surface is performed.

  With this planarization method, the first step mainly eliminates the initial step on the surface of the metal film (conductive film) in the pattern portion, and the second step mainly reduces the step between the pattern portion on the surface of the metal film and the field portion. This eliminates the problem that the metal film surface on the entire surface of the workpiece can be polished flat. Most preferably, the polishing rate of the metal film in the field portion in the first polishing and the polishing rate of the metal film in the pattern portion in the second polishing are both zero.

  The first polishing is continued until the initial level difference on the surface of the metal film in the pattern portion is eliminated. When the polishing rate of the metal film in the pattern portion in the first polishing is low, the thickness of the metal film that can be used to eliminate the step on the surface of the metal film between the pattern portion and the field portion in the second polishing is reduced. Therefore, in the first polishing, the polishing rate of the metal film in the pattern portion is increased at least twice as much as the polishing rate of the metal film in the field portion, and a step is formed between the pattern portion and the field portion in the first polishing. It is desirable to increase the speed that is played.

It is preferable that at least one of the first polishing and the second polishing is performed by electrolytic processing.
Thereby, CMP itself can be omitted or this load can be reduced.

  In a preferred aspect of the present invention, the workpiece is provided with a processing member by applying a voltage between a processing electrode close to the surface of the metal film of the workpiece and a power supply electrode that feeds the metal film. The first polishing and the second polishing are performed by supplying a liquid between the processing electrode and at least one of the power supply electrode and relatively moving the workpiece and at least one of the processing electrode or the power supply electrode. Do each.

  As described above, by polishing the metal film at a pressure lower than that of the conventional CMP by electrochemical interaction, it is possible to prevent the characteristics of the metal film from being damaged. As the liquid, it is preferable to use ultrapure water, pure water, or a liquid or electrolytic solution having an electric conductivity of 500 μS / cm or less, which can significantly reduce contamination of the surface of the workpiece, Cleaning after processing and disposal of waste liquid are also facilitated.

The processing member is preferably made of an ion exchanger or a material containing an ion exchanger.
In a preferred aspect of the present invention, the first polishing is performed by bringing the pattern portion and the processing member into contact with each other, and the second polishing is performed with the pattern portion and the processing member being in a non-contact state.

  In particular, when an ion exchanger or the like is used as the processing member, the processing member (ion exchanger or the like) is brought into contact with the pattern portion to perform the first polishing, and the processing member (ion exchanger or the like) and the pattern portion are By making the non-contact state, the second polishing can be performed in which the polishing rate of the metal film in the pattern portion is slower than the first polishing. During the second polishing, the processing member may be in contact with the field portion of the metal film.

  In order to perform polishing while the processing member is not in contact with the pattern portion, it is necessary to reduce deformation of the processing member due to contact pressure. For this reason, a processing member having a high rigidity, for example, a shape that increases the Young's modulus or increases the thickness of the processing member to increase the second moment of section is used. The The contact pressure between the processing member and the metal film in the field portion may be reduced.

  In a preferred aspect of the present invention, the first polishing is performed by bringing the pattern portion and the processing member into contact with each other, and the resistance formation processing of the pattern portion is performed before or simultaneously with the second polishing.

By performing the resistance forming process for forming a resistance in the pattern portion, the polishing rate of the metal film in the pattern portion can be delayed. Examples of the resistance forming process include the following processes.
(1) The pattern portion is exposed to an oxidizing agent (H ₂ O ₂ , O _3, etc.) or a complexing agent, and the metal film surface in the pattern portion is passivated or complexed so that the reactive species ions are in the metal film in the pattern portion. Processing to suppress reaching the surface.
(2) Insulating additive is introduced into the liquid, and the metal film surface in the pattern part is covered with the additive (insulator) to prevent reactive species ions from reaching the metal film surface in the pattern part. To do.
(3) Treatment that suppresses the reaction between the reactive species ions and the metal film by introducing an anticorrosive agent such as BTA (benzotriazole) into the liquid to suppress the reaction between the reactive species ions and the metal film. .

  Although the resistance forming process is desirably performed only on the pattern portion, it may be performed to the field portion as long as it can be removed or removed from the field portion by the contact pressure of the processing member or the contact member. The resistance forming process may be performed before the second polishing or simultaneously with the second polishing.

In a preferred aspect of the present invention, the second polishing is performed in a non-contact state between the pattern portion and the processing member while performing a resistance forming process for the pattern portion.
By preventing the processing member from coming into contact with the pattern portion during the second polishing, resistance such as a passivated film, a complex, or an insulator formed on the metal film surface of the pattern portion by the resistance forming process. However, it is possible to prevent the contact with the processing member from being removed.

  You may make it perform at least one of the said 1st grinding | polishing and the said 2nd grinding | polishing by making the contact member arrange | positioned in the vicinity of the said process electrode and / or the said power supply electrode contact the said metal film surface of the said to-be-processed object.

  In a preferred aspect of the present invention, a voltage is applied between a machining electrode close to the metal film of the workpiece and a feeding electrode that feeds the metal film, and the workpiece and the machining electrode or the feeding electrode are applied. The first polishing and the second polishing are performed by supplying a liquid between at least one of the workpiece and relatively moving the workpiece and at least one of the processing electrode or the feeding electrode, respectively.

  The resistance forming process may be performed before the second polishing or simultaneously with the second polishing. Further, the second polishing may be performed while the pattern portion and the processing electrode are in a non-contact state while performing the resistance forming process of the pattern portion.

You may perform at least one of said 1st grinding | polishing and the said 2nd grinding | polishing by making the contact member arrange | positioned in the vicinity of the said process electrode and / or the said power supply electrode contact the electrically conductive film surface of the said to-be-processed object.
The distance between the processing electrode and the metal film surface of the workpiece may be 0.05 μm or more and 50 μm or less, and at least one of the first polishing and the second polishing may be performed.

  By using an ionic reaction accelerator in combination with a liquid having an electric conductivity of 500 μS / cm or less, the first polishing is performed so that the distance between the processing electrode and the metal film surface of the workpiece is 0.05 μm or more and 50 μm or less. be able to. The ionic reaction accelerator acts as an insulating additive or preservative used in the resistance forming treatment and can prevent the adsorption of a substance that suppresses the electrolytic treatment to maintain the electrolytic treatment (reaction). As the ionic reaction accelerator, organic sulfur having a sulfone group represented by bis (3-sulfopolypyr) disulfide is preferably used. When the electrical conductivity of the liquid is high, the polishing of the metal film in the pattern portion and the field portion is both isotropic, and there is no difference in the polishing rate of the metal film in the pattern portion and the field portion. By reducing the size, it is possible to bring these polishings closer to anisotropy and to make a difference in the polishing rate of the metal film in the pattern portion and the field portion. Further, at the time of polishing, the ionic reaction accelerator is concentrated on the portion where the electric field strength is strong, that is, on the upper end of the convex portion of the metal film in the pattern portion, whereby the polishing rate of the metal film in the pattern portion can be increased. When electrolytic polishing was performed while changing the distance between the processing electrode and the metal film, it has been experimentally confirmed that the metal film can be suitably polished by setting this distance to 0.05 μm to 50 μm.

The end point of the first polishing can be detected by time management, table current detection, or image recognition.
Time management is processing time management, and the first polishing is terminated when a predetermined processing time determined under the current condition has elapsed.

  As the first polishing progresses, the pattern shape in the pattern portion, that is, the step on the metal film surface is gradually eliminated, and the point at which the step is almost completely eliminated and flattened is defined as the end point of the first polishing. For example, when the metal film surface is polished while the processing member is in contact with the metal film, the contact area between the metal film and the processing member increases when the metal film surface is flattened as the polishing progresses. As a result, the table current increases, and the pattern shape gradually disappears when it is considered as a change in the pattern image. Therefore, the end point of the first polishing can be detected by detecting the table current or recognizing the image.

In the planarization apparatus of the present invention, the polishing rate of the conductive film in the pattern portion is higher than the polishing rate of the conductive film in the field portion on the conductive film surface having the pattern portion and the field portion formed on the workpiece. A first polishing portion that polishes in a high state and a second polishing portion that polishes the conductive film surface in a state where the polishing rate of the conductive film in the field portion is higher than the polishing rate of the conductive film in the pattern portion.
It is preferable that at least one of the first polishing portion and the second polishing portion is polished by electrolytic processing.

  According to the present invention, even if an initial step is formed on the surface of a metal film (conductive film) such as a copper film as a wiring material, the surface of the conductive film is polished flatly over the entire surface, The surface can be flattened more easily.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, a substrate is used as a workpiece, and a copper film 6 (see FIG. 1B) as a wiring material formed on the surface of the substrate is used as a metal film (conductive film) to be processed. In this example, the surface of the film (metal film) 6 is processed and flattened. Needless to say, the present invention can also be applied to planarization of a workpiece other than a substrate and a metal film (conductive film) other than a copper film.

  FIG. 5 is a plan view showing the flattening device according to the embodiment of the present invention. As shown in FIG. 5, the flattening apparatus carries in and out a cassette containing a substrate W having a copper film 6 as a metal film (conductive film) to be processed on the surface, for example, as shown in FIG. 1B. A pair of loading / unloading sections 30 as loading / unloading sections, a reversing machine 32 for inverting the substrate W, and a resist processing apparatus as a coating material processing apparatus that applies a resist as a coating material to the surface of the substrate W and exposes it. 34, an electrolytic processing apparatus 36 that performs electrolytic processing without using an abrasive, and a cleaning unit 38 that cleans and dries the substrate W after electrolytic processing. These devices are arranged in series, and a transfer robot 40 as a transfer device that transfers the substrate W between these devices and transfers it is arranged so as to be able to run in parallel with these devices. In addition, a monitor unit 42 that monitors a voltage applied between a machining electrode and a feeding electrode, which will be described later, or a current flowing between them, is adjacent to the load / unload unit 30 during electrolytic machining by the electrolytic machining apparatus 36. Are arranged.

  FIG. 6 shows a resist processing apparatus (coating material processing apparatus) 34 in the substrate processing apparatus. As shown in FIG. 6, the resist processing apparatus 34 mainly includes a resist coating unit 50 and an exposure unit 52. The resist coating unit 50 has a rotatable substrate stage 54 that detachably holds the substrate W with the surface on which the copper film 6 (see FIG. 1B) is formed facing upward, and can swing freely above the substrate stage 54. A resist dropping unit which is attached to a free end of the swing arm 56 disposed and moves between a substantially central processing position of the substrate W held by the substrate stage 54 and a side retracted position. A nozzle 58 is provided. An exposure unit 52 having a built-in ultraviolet lamp 60 is disposed immediately above the substrate stage 54. Further, although not shown, the resist coating device 34 is provided with a developing unit that supplies a developing solution to the surface of the substrate W and develops the exposed resist, and a cleaning unit that cleans the developed substrate surface. After cleaning the substrate, a heater stage for baking the resist at, for example, 100 to 150 ° C. may be installed on the side of the resist processing apparatus 34 or the like.

In this example, a positive photoresist made of an insulating material having a resistivity of 10 ⁶ Ω · cm or more (conductivity 1 μS / cm or less) is used as a coating material, and this positive photoresist 62 is applied to the surface of the substrate W. I try to apply. Resist includes X-ray resist, electron beam resist, etc. in addition to the photoresist depending on the wavelength of light to be exposed. In the present invention, any resist may be used. Moreover, it can be classified into a positive type and a negative type depending on whether the exposed part is dissolved by development or the non-exposed part is dissolved. In this example, the positive type is used, but the negative type is used. You may do it. Instead of the resist, paint, oil-based ink (oil-based marker), dry adhesive, or the like may be used.

  The operation of the resist processing apparatus 34 will be described with reference to FIGS. First, the substrate W is held on the upper surface of the substrate stage 54 with the surface facing upward. Then, the resist dropping nozzle 58 that has been in the side retracted position of the substrate stage 54 is moved to a processing position substantially at the center of the substrate W held by the substrate stage 54. In this state, the positive photoresist 62 is dropped from the resist dropping nozzle 58 almost at the center of the substrate W, and the substrate W is rotated together with the substrate stage 54 and spin-coated. As a result, as shown in FIG. 7A, the positive photoresist 62 is made to enter the recess 6 a of the copper film (metal film) 6 covering the buried insulating film 2 inside the trench 4 provided in the insulating film 2. It is uniformly applied to the surface of the film 6.

  Next, the resist dripping nozzle 58 is moved from the processing position to the retracted position, and ultraviolet rays are irradiated from the ultraviolet lamp 60 of the exposure unit 52 toward the surface of the substrate W, thereby, as shown in FIG. The other resist 62b is exposed leaving the resist 62a located at the bottom of the recess 6a. Then, a developing solution is supplied to the surface of the substrate W and developed to remove the exposed resist 62b as shown in FIG. 7C. Thus, the recess 6a of the copper film 6 is covered with a covering layer (insulating layer) made of an insulating material resist (covering material) 62 (62b).

  And the surface of the board | substrate W is wash | cleaned (rinsing) with a pure water etc., for example, the baking process of 100-150 degreeC is performed as needed. Thus, by removing the resist 62 by baking the resist 62 and evaporating the solvent in the resist 62, the removal rate of the resist 62 in the following electrolytic processing can be changed. By utilizing this, by adjusting the baking processing temperature and baking processing time, it is possible to control the selection ratio in the electrolytic processing between the copper film (metal film) 6 and the resist 62 and to flatten the copper film 6. Become. Generally, the resist processing speed is lowered by baking at a high temperature for a long time.

  8 is a plan view schematically showing the electrolytic processing apparatus 36 shown in FIG. 5, and FIG. 9 is a longitudinal sectional view of FIG. As shown in FIGS. 8 and 9, the electrolytic processing apparatus 36 includes an arm 240 that can move up and down and reciprocate along a horizontal plane, and a substrate W that is suspended from the free end of the arm 240 downward (face-down). ) And a movable frame 244 to which the arm 240 is attached.

  A vertical movement motor 250 is installed on the upper part of the movable frame 244, and a ball screw 252 extending in the vertical direction is connected to the vertical movement motor 250. The base 240 a of the arm 240 is engaged with the ball screw 252, and the arm 240 moves up and down via the ball screw 252 as the up and down movement motor 250 is driven. The movable frame 244 is attached to a ball screw 254 extending in the horizontal direction, and reciprocates along the horizontal plane with the arm 240 as the reciprocating motor 256 is driven.

  The substrate holding part 242 is connected to a rotation motor 258 installed at the free end of the arm 240 and rotates (autorotates) as the rotation motor 258 is driven. As described above, the arm 240 can move up and down and reciprocate in the horizontal direction, and the substrate holding part 242 can move up and down and reciprocate in the horizontal direction integrally with the arm 240.

  A rectangular electrode portion 246 is disposed below the substrate holding portion 242. The size of the electrode portion 246 is set to be slightly larger than the outer diameter of the substrate W held by the substrate holding portion 242.

  A hollow motor 260 is installed below the electrode portion 246, and a driving end 264 is provided on the main shaft 262 of the hollow motor 260 at a position eccentric from the center of the upper end surface of the main shaft 262. The electrode portion 246 is rotatably connected to the drive end 264 via a bearing (not shown) at the center thereof. Between the electrode part 246 and the hollow motor 260, three or more rotation prevention mechanisms (not shown) are provided in the circumferential direction. As a result, the electrode section 246 performs a scroll motion (translation rotation motion) by driving the hollow motor 260.

  Next, the electrode part 246 will be described in detail. FIG. 10 is a longitudinal sectional view of the electrode portion 246. As shown in FIGS. 8 and 10, the electrode portion 246 includes a plurality of electrode members 282 extending in the X direction (see FIG. 8), and these electrode members 282 are arranged in parallel on a flat plate-like processing table 284. Are arranged at equal pitches.

  As shown in FIG. 10, each electrode member 282 includes an electrode 286 connected to a power source 248 (see FIG. 8), and an ion exchanger 290 as a processing member that integrally covers the surface of the electrode 286. ing. The ion exchanger 290 is attached to the electrode 286 by holding plates 285 disposed on both sides of the electrode 286.

  In this example, an ion exchanger is used as the processing member. However, a material containing the ion exchanger or a foamed polyurethane pad (for example, IC-1000, manufactured by Rohm and Haas Electronic Materials) The processing member may be composed of a polishing pad such as a fixed abrasive pad, a PVA sponge, or the like.

  It is more preferable to use an ion exchanger 290 having excellent water permeability. By flowing pure water or ultrapure water so that it passes through the ion exchanger 290, sufficient water is supplied to the functional group that promotes the dissociation reaction of water (sulfonic acid group in the case of a strongly acidic cation exchange material). The amount of molecular dissociation can be increased, and the processing products (including gas) generated by the reaction with hydroxide ions (or OH radicals) can be removed by the flow of water, thereby increasing the processing efficiency. As such a water-permeable member, for example, a sponge-like member having liquid permeability or a membrane-like member such as Nafion (trademark of DuPont) is provided with water permeability. Can be used.

  The ion exchanger 290 may be composed of a nonwoven fabric provided with an anion exchange group or a cation exchange group. The cation exchanger is preferably one that bears a strongly acidic cation exchange group (sulfonic acid group), but may be one that bears a weak acid cation exchange group (carboxyl group). The anion exchanger is preferably one carrying a strong basic anion exchange group (quaternary ammonium group), but may be one carrying a weak basic anion exchange group (tertiary or lower amino group). Examples of the material of the ion exchanger 290 include polyolefin polymers such as polyethylene and polypropylene, and other organic polymers. Examples of the material form include a woven fabric, a sheet, a porous material, a net, or a short fiber in addition to the non-woven fabric. A strongly acidic cation exchange fiber (nonwoven fabric ion exchanger) may be arranged inside the ion exchanger 290 to increase the ion exchange capacity.

  For example, a nonwoven fabric provided with a strongly basic anion exchange group is grafted by a so-called radiation graft polymerization method in which a polyolefin nonwoven fabric having a fiber diameter of 20 to 50 μm and a porosity of about 90% is subjected to graft polymerization after γ-ray irradiation. It is prepared by introducing a chain and then aminating the introduced graft chain to introduce a quaternary ammonium group. The capacity of the ion exchange group to be introduced is determined by the amount of graft chains to be introduced. In order to carry out graft polymerization, for example, monomers such as acrylic acid, styrene, glycidyl methacrylate, chloromethyl styrene and the like are used, and by controlling the monomer concentration, reaction temperature and reaction time, the amount of grafting to be controlled is controlled. be able to. Therefore, the ratio of the weight increased by the graft polymerization to the weight of the material before the graft polymerization is called the graft ratio. This graft ratio can be 500% at the maximum, and the ion exchange group introduced after the graft polymerization. Can be up to 5 meq / g.

  The nonwoven fabric provided with the strongly acidic cation exchange group was irradiated with γ-rays on a polyolefin nonwoven fabric having a fiber diameter of 20 to 50 μm and a porosity of about 90% in the same manner as the method of providing the strongly basic anion exchange group. The graft chain is introduced by a so-called radiation graft polymerization method in which post-graft polymerization is performed, and then the introduced graft chain is treated with, for example, heated sulfuric acid to introduce a sulfonic acid group. Moreover, a phosphoric acid group can be introduce | transduced if it processes with the heated phosphoric acid. Here, the graft ratio can be 500% at the maximum, and the ion exchange group introduced after the graft polymerization can be 5 meq / g at the maximum.

  Examples of the material of the ion exchanger 290 include polyolefin polymers such as polyethylene and polypropylene, and other organic polymers. Moreover, as a raw material form of the ion exchanger 290, a woven fabric, a sheet | seat, a porous material, a short fiber other than a nonwoven fabric are mentioned. When polyethylene or polypropylene is used as a material, radiation (gamma ray or electron beam) is first irradiated to the material (pre-irradiation) to generate radicals in the material, and then react with the monomer for graft polymerization. be able to. Thereby, a graft polymer having high uniformity and few impurities can be obtained. On the other hand, when an organic polymer other than polyolefin is used as a material, radical polymerization can be performed by impregnating the material with a monomer and irradiating (simultaneously irradiating) radiation (γ rays, electron beams, and ultraviolet rays) there. it can. In this case, the uniformity of the graph and the chain is lacking, but it can be applied to most materials.

  By constituting the ion exchanger 290 with a nonwoven fabric provided with an anion exchange group or a cation exchange group, a liquid such as pure water or ultrapure water can freely move inside the nonwoven fabric, and the water decomposition catalytic action inside the nonwoven fabric can be achieved. It becomes possible to easily reach the active site, and many water molecules are dissociated into hydrogen ions and hydroxide ions. Furthermore, since hydroxide ions generated by dissociation are efficiently carried to the surface of the electrode 286 as the liquid such as pure water or ultrapure water moves, a high current can be obtained even at a low applied voltage.

  When the ion exchanger 290 is composed only of an anion exchange group or a cation exchange group, not only the work material that can be electrolytically processed but also the impurities are likely to be generated depending on the polarity. Therefore, an anion exchanger having an anion exchange group and a cation exchanger having a cation exchange group are overlapped, or both anion exchange groups and cation exchange groups are added to the ion exchanger 290 itself. In this case, the range of the material to be processed can be expanded, and impurities can be hardly generated.

  In this example, the cathode and the anode of the power source 248 are alternately connected to the electrode 286 of the adjacent electrode member 282. For example, the electrode 286a (see FIG. 10) is connected to the cathode of the power source 248, and the electrode 286b (see FIG. 10) is connected to the anode. For example, in the case of processing copper, an electrolytic processing action occurs on the cathode side, so that the electrode 286 connected to the cathode becomes the processing electrode 286a and the electrode 286 connected to the anode becomes the power supply electrode 286b. Thus, in this example, the processing electrodes 286a and the feeding electrodes 286b are alternately arranged in parallel.

  Depending on the processing material, the electrode connected to the cathode of the power source may be used as the feeding electrode, and the electrode connected to the anode may be used as 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. Therefore, the electrode 286a connected to the cathode of the power source becomes the processing electrode, and the electrode 286b connected to the anode serves as the feeding electrode. It becomes. On the other hand, when the material to be processed is, for example, aluminum or silicon, an electrolytic processing action occurs on the anode side, so that the electrode 286b connected to the anode of the power source becomes the processing electrode, and the electrode 286a connected to the cathode becomes the feeding electrode. .

  As described above, the processing electrode 286a and the feeding electrode 286b are alternately provided in the Y direction of the electrode portion 246 (direction perpendicular to the longitudinal direction of the electrode member 282), whereby the copper film (metal film) 6 (see FIG. 1B), it is not necessary to provide a power supply unit for supplying power, and the entire surface of the substrate W can be processed. Further, by changing the polarity of the voltage applied between the electrodes 286 in a pulse shape, the electrolytic product can be dissolved, and the flatness of the processed surface can be improved by the multiplicity of processing repetition.

  Here, oxidation or elution of the electrode 286 of the electrode member 282 generally causes a problem due to an electrolytic reaction. For this reason, it is preferable to use carbon, a comparatively inactive noble metal, a conductive oxide, or a conductive ceramic rather than the metal and metal compound currently widely used for the electrode as a raw material of an electrode. As an electrode made of this noble metal, for example, titanium is used as the base electrode material, platinum or iridium is attached to the surface by plating or coating, and sintering is performed at a high temperature to maintain stability and strength. Can be mentioned. Ceramic products are generally obtained by heat treatment using inorganic materials as raw materials, and products having various characteristics are made using various nonmetals, metal oxides, carbides and nitrides as raw materials. Some of these are conductive ceramics. When the electrode is oxidized, the electrical resistance value of the electrode increases, leading to an increase in applied voltage. However, by protecting the electrode surface with a material that is difficult to oxidize such as platinum or a conductive oxide such as iridium, the electrode material is oxidized. A decrease in conductivity can be prevented.

  As shown in FIG. 10, a flow path 292 for supplying pure water, more preferably ultrapure water to the surface to be processed is formed inside the processing table 284 of the electrode portion 246, and this flow path 292. Is connected to a pure water supply source (not shown) via a pure water supply pipe 294. Support members 296 are erected on both sides of each electrode member 282, and contact members 298 that are in contact with the surface (lower surface) of the substrate W are installed on the upper surface of each support member 296. A communication hole 296 a communicating with the flow path 292 is formed inside the support 296 and the contact member 298, and pure water, preferably ultrapure water is supplied to the substrate W and the electrode member 282 through the communication hole 296 a. To the ion exchanger 290.

  As the contact member 298, a CMP pad, a fixed abrasive pad, a PVA sponge, or the like can be used. An ion exchanger or a material containing an ion exchanger may be used.

  In this electrolytic processing apparatus 36, as shown in FIG. 11, the substrate W is pressed against the ion exchanger 290 with a certain amount of force to bring the substrate W into contact with the upper surface of the contact member 298. Thereby, the contact member 298 receives the pressing force of the substrate W, the contact area between the substrate W and the ion exchanger 290 is not changed, the substrate W is prevented from being tilted, and the contact area is made uniform. Can be realized. The contact member 298 can adjust the removal processing speed of a coating material such as a resist.

  A through-hole 300 that leads from the flow path 292 to the ion exchanger 290 is formed inside the electrode 286 of each electrode member 282. With such a configuration, fluid such as pure water or ultrapure water in the flow path 292 is supplied to the ion exchanger 290 through the through hole 300.

  The present invention is not limited to electrolytic processing using an ion exchanger. For example, when an electrolytic solution is used as the processing liquid, the processing member attached to the surface of the electrode is not limited to the ion exchanger, and may be a soft polishing pad or a nonwoven fabric.

  In the operation of the electrolytic processing apparatus 36 having such a configuration, as shown in FIG. 11, the ion exchanger 290 of the electrode unit 246 is brought into contact with the upper surface of the contact member 298 while the substrate W held by the substrate holding unit 242 is brought into contact therewith. Also contact the surface. In this state, while rotating the substrate W held by the substrate holding portion 242, the hollow motor 260 is driven to cause the electrode portion 246 to scroll, and at the same time, the substrate W, the electrode member 282, In the meantime, pure water or ultrapure water is supplied, and pure water or ultrapure water is included in the ion exchanger 290 through the through holes 300 of the electrode members 282. In this example, pure water or ultrapure water supplied to the ion exchanger 290 is discharged from the longitudinal ends of the electrode members 282. Then, a predetermined voltage is applied between the processing electrode 286a and the feeding electrode 286b by the power source 248, and the electrolytic processing of the copper film (metal film) 6 deposited on the surface of the substrate W is performed.

  Next, electrolytic processing using the planarization apparatus in this embodiment will be described. First, for example, as shown in FIG. 1B, a substrate W in which a copper film 6 is formed as a metal film (processed portion) on the surface of the insulating film 2 while being embedded in the trench 4 formed in the insulating film 2 is accommodated. A cassette is set in the load / unload unit 30, and one substrate W is taken out from the cassette by the transfer robot 40. As shown in FIG. 12A, the copper film 6 is formed with a pattern portion P having a large number of concave portions 6a and convex portions 6b, and a field portion F surrounding the pattern portion P. The transfer robot 40 transfers the taken substrate W to a resist processing apparatus (coating material processing apparatus) 34, and in this example, the resist processing apparatus 34 insulates the recess 6a of the copper film 6 as described above. A covering layer (insulating layer) made of a material resist (covering material) 62 is covered. Then, the resist 62 is baked at a predetermined temperature for a predetermined time to adjust the removal speed of the resist 62 in electrolytic processing.

  The transfer robot 40 receives the substrate W after the baking process from the resist processing apparatus 34, transfers it to the reversing machine 32 as necessary, and reverses the substrate W so that the surface on which the copper film 6 is formed faces downward.

  The transport robot 40 receives the inverted substrate W, transports it to the electrolytic processing apparatus 36, and sucks and holds it on the substrate holder 242. Next, the vertical movement motor 250 is driven to lower the substrate holding portion 242, and the substrate W held by the substrate holding portion 242 is brought into contact with the contact member 298 of the electrode portion 246 and the surface of the ion exchanger 290. In this state, the rotation motor 258 is driven to rotate the substrate W, and at the same time, the hollow motor 260 is driven to scroll the electrode portion 246. At the same time, pure water or ultrapure water is supplied between the substrate W and the ion exchanger 290.

  Then, a predetermined voltage is applied between the processing electrode 286a and the feeding electrode 286b by the power source 248, and electrolytic processing is performed on the processing electrode (cathode) 286a by hydrogen ions or hydroxide ions generated by the ion exchanger 290. Do. In this processing, the concave portion 6a in the pattern portion P of the copper film 6 is made of an insulating material, and thus is covered with a resist (coating material) 62 that suppresses processing by electrolytic processing. Therefore, the copper film 6 The portion not covered with the resist (coating material) 62 is preferentially processed, and the surface of the copper film 6 is gradually flattened.

  That is, as shown in FIG. 12A, a resist (coating material) 62 made of an insulating material is used as the bottom of the recess 6a in the pattern portion P of the copper film 6 formed while being buried in the trench 4 formed inside the insulating film 2. When the electrolytic processing is started in a state of being covered with, first, the convex portion 6b of the copper film 6 in the pattern portion P is mainly processed preferentially, and as a result, as shown in FIG. Is flattened. As the processing further progresses, the processing of the copper film 6 in the pattern portion P is suppressed, and the copper film 6 in the field portion F is processed preferentially. As a result, as shown in FIG. The pattern portion P and the field portion F are flattened in a state where the resist (coating material) 62 made of an insulating material is left slightly in the concave portion 6a in the portion P. When the processing further proceeds, the resist 62 remaining in the recess 6a in the pattern portion P of the copper film 6 is removed, and the surface of the copper film 6 is flattened as shown in FIG. 12D.

  As this resist 62, even when electrolytic processing is performed by applying a voltage of, for example, 10 V or more between the processing electrode 286a and the feeding electrode 286b, the bonding strength with the copper film 6 is not separated from the copper film 6. By using a material that forms a high coating layer (insulating layer), a sufficient processing speed can be obtained while maintaining the effect of suppressing the electrolytic reaction by the resist 62.

  As described above, it is preferable that the covering material such as the resist 62 made of an insulating material is slightly processed at a slower speed than the metal film such as the copper film 6 by electrolytic processing. Moreover, the surface of the copper film 6 can be flattened without leaving the resist 62 on the surface of the copper film 6 by adjusting the selection ratio between the processing speed of the resist 62 and the processing speed of the copper film 6 in electrolytic processing. .

  As described above, the resist (coating material) 62 can also be processed by moving the contact member 298 relatively while contacting the surface of the copper film 6 and scraping the surface of the coating material with the contact member 298. The speed can be adjusted. The same applies to the following examples.

  In this example, the copper film 6 and the resist 62 are continuously processed, and the surface of the copper film 6 is planarized without leaving the resist 62. However, for example, the processing speed of the resist 62 is shown. Therefore, in continuous processing, it may be difficult to remove the resist 62 without leaving it and planarize the surface of the copper film 6. In such a case, for example, as shown in FIG. 12C, when the surface of the copper film 6 in the pattern portion P and the field portion F is flattened and the resist 62 is exposed on the surface of the copper film 6, the resist 62 is exposed. Then, the surface of the copper film 6 may be flattened without leaving the resist 62 as shown in FIG. 12D by further processing the surface of the copper film 6. The processing after removing the resist 62 may be performed by electrolytic processing using, for example, an electrolytic solution or ultrapure water, or may be performed by an arbitrary method such as normal CMP.

  As described above, the contact member 298 is brought into contact with the surface of the copper film 6 and the two are relatively moved, thereby removing, for example, the resist 62 exposed on the surface of the copper film 6 with the contact member 298 shown in FIG. 12C. You may make it do.

  After the electrolytic processing is completed, the processing electrode 286a and the power supply electrode 286b are disconnected from the power source 248, and the rotation of the substrate holding portion 242 and the scroll motion of the electrode portion 246 are stopped. Thereafter, the substrate holding unit 242 is raised, the arm 240 is moved, and the substrate W is delivered to the transport robot 40. The transport robot 40 that has received the substrate W transports the substrate W to the reversing machine 32 as necessary to reverse the substrate W, and then returns the substrate W to the cassette of the load / unload unit 30.

  Here, the pure water supplied between the substrate W and the ion exchanger 290 during the electrolytic processing is water having an electric conductivity of 10 μS / cm or less, and ultrapure water has, for example, an electric conductivity of 0. .1 μS / cm or less of water. By performing electrolytic processing using pure water or ultrapure water that does not contain an electrolyte, it is possible to prevent extra impurities such as electrolyte from adhering to or remaining on the surface of the substrate W. Furthermore, since copper ions and the like dissolved by electrolysis are immediately captured by the ion exchanger 290 by an ion exchange reaction, the dissolved copper ions and the like are re-deposited on other parts of the substrate W or oxidized to form fine particles. The surface of the substrate W is not contaminated.

Instead of pure water or ultrapure water, a liquid having an electric conductivity of 500 μS / cm or less, for example, an electrolytic solution obtained by adding an electrolyte to pure water or ultrapure water may be used. By using the electrolytic solution, electric resistance can be reduced and power consumption can be reduced. As this electrolytic solution, for example, a neutral salt such as NaCl or Na ₂ SO ₄ , an acid such as HCl or H ₂ SO ₄ , or an alkali such as ammonia can be used. Depending on the characteristics, it can be appropriately selected and used.

  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 0.1 μS. A liquid having a specific resistance of 10 MΩ · cm or less may be used. By adding a surfactant to pure water or ultrapure water, a layer having a uniform inhibitory action to prevent ion migration is formed at the interface between the substrate W and the ion exchanger 290, whereby ion exchange (metal Of the surface to be processed can be improved. Here, the surfactant concentration is preferably 100 ppm or less. If the value of the electrical conductivity is too high, the current efficiency is lowered and the processing speed is slowed down. However, the electrical conductivity is 500 μS / cm or less, preferably 50 μS / cm or less, more preferably 0.1 μS / cm or less. A desired processing speed can be obtained by using a liquid having

  FIG. 13 shows another example of a resist processing apparatus as a coating material processing apparatus. As shown in FIG. 13, the resist processing apparatus (coating material processing apparatus) 34a has a resist coating unit 50 and a resist wiping unit 70 having the same configuration as the resist processing apparatus 34 shown in FIG. The resist wiping unit 70 includes a rotating plate 72 that is disposed above and below the substrate stage 54 of the resist coating unit 50 so as to be vertically movable and rotatable, and a wiping pad 74 that is attached downward to the lower surface of the rotating plate 72. Yes.

  In this resist processing apparatus 34 a, a resist 62 is dropped from a resist dropping nozzle 58 almost at the center of the substrate W held on the upper surface of the substrate stage 54, and the substrate W is rotated together with the substrate stage 54 to spin. Coat. As a result, as shown in FIG. 14A, the resist 62 is applied to the copper film 6 while entering the recess 6a of the copper film (metal film) 6 covering the insulating film 2 while being buried in the trench 4 provided in the insulating film 2. Apply evenly to the surface. Next, the rotating plate 72 is lowered while rotating, and the surface (lower surface) of the wiping pad 74 is rubbed against the surface of the resist 62. As a result, as shown in FIG. 14B, the resist 62 located on the upper part of the convex part 6 b of the copper film 6 is removed while leaving the resist 62 located in the concave part 6 a of the copper film 6. Only 6a is coated with a coating layer made of resist (coating material) 62.

  As described above, when the resist 62 is dropped on the surface of the substrate W and then the substrate W is rotated and spin-coated, the concave portion 6a of the copper film 6 is applied thicker than the convex portion 6b. For example, in the case of a pattern in which the wiring portion is 9 μm and the space portion is 1 μm, the film thickness difference between the resist 62 in the wiring portion and the space portion can be 400 nm or more. Therefore, by rubbing the surface (lower surface) of the wiping pad 74 against the surface of the resist 62, it is possible to selectively remove only the resist 62 positioned on the upper portion of the convex portion 6b of the copper film 6.

In this example, any resist other than a positive photoresist can be used as the coating material.
It should be noted that a heater stage may be installed on the side of the resist processing apparatus 34a or the like, and the resist 62 may be baked at, for example, 100 to 150 ° C. to adjust the removal speed in the electrolytic processing of the resist 62. Same as above.

In the above example, the insulating layer (coating layer) is formed using a resist made of an insulating material having a resistivity of 10 ⁶ Ω · cm or more (electric conductivity 1 μS / cm or less) as the coating material. The conductive layer (coating layer) may be formed using a conductive material having a resistivity of 10 ³ Ω · cm or less (conductivity of 10 ³ μS / cm or more). Examples of the conductive material include conductive paint, conductive ink, conductive adhesive, or conductive paste. These conductive materials are obtained by blending conductive particles such as metal fine particles and carbon in a resin to impart conductivity, and the conductivity can be controlled by the blending amount of the conductive particles.

  Even when a conductive material is used as the covering material 64, first, as shown in FIG. 15A, a copper film formed on the surface of the insulating film 2 while being embedded in the trench 4 provided in the insulating film 2 The recess 6 a of the (metal film) 6 is covered with a coating material 64. As this coating method, for example, a conductive ink such as an oil-based marker is applied to the entire surface of the copper film 6, and then the conductive ink on the surface of the copper film 6 is wiped off with alcohol or thinner, For example, the conductive ink may be selectively applied only to the six recesses 6a.

  Then, the surface of the copper film 6 is flattened by electrolytically processing the substrate W in which the concave portion 6a of the copper film 6 is covered with a coating layer (conductive layer) made of the coating material 64. As shown in FIG. 15A, when the convex portion 6b of the copper film (metal film) 6 in the pattern portion P protrudes from the surface of the coating material 64, the convex portion 6b and the copper film 6 of the field portion F are provided. Are preferentially processed, and the pattern portion P and the field portion F are flattened as shown in FIG. 15B. As the processing further proceeds, an electrolytic reaction proceeds on the surface of the coating material 64, and an electron current flows through the coating material 64 to the copper film 6 in the recess 6 a, so that the entire surface of the copper film 6 including the coating material 64 is covered. The current density becomes more uniform, whereby the surface of the copper film 6 is processed more uniformly over the entire surface, as shown in FIG. 15C. When the processing further proceeds, the coating material 64 remaining in the recess 6a in the pattern portion P of the copper film 6 is removed, and the surface of the copper film 6 is flattened.

  Even in this case, it is preferable that the coating material 64 made of a conductive material is somewhat processed at a slower rate than the metal film such as the copper film 6 by electrolytic processing, and the processing speed of the coating material 64 in the electrolytic processing and the copper By adjusting the selection ratio of the processing speed of the film 6, the surface of the copper film 6 can be planarized without leaving the coating material 64 on the surface of the copper film 6.

  As described above, when the coating material 64 is exposed on the surface of the copper film 6, the coating material 64 is removed in a separate process, and then the surface of the copper film 6 is further processed, The contact material 298 may be removed while the contact member 298 is moved with the contact member 298 in contact with the cover material 64 exposed on the surface of the copper film 6.

FIG. 16 shows the main part of the electrode part in another example of the electrolytic processing apparatus. The difference between the electrode portion 246a of this electrolytic processing apparatus and the electrode portion 246 in the above-described electrolytic processing apparatus is as follows.
The electrode portion 246a includes a plurality of electrodes 302 extending in parallel with each other, and these electrodes 302 are not covered with an ion exchanger or the like, and are exposed to the outside in parallel on a flat plate-like processing table. They are arranged at an equal pitch. For example, when processing copper, the electrode 302 connected to the power source cathode becomes the processing electrode 302a, and the electrode 302 connected to the anode 302 is connected to the adjacent electrodes 302 alternately. Becomes the power supply electrode 302b.

  A flow path for supplying a liquid (electrolytic solution) such as pure water to the surface to be processed is formed inside the processing table of the electrode portion 246a, and this flow path is a liquid supply source via a liquid supply pipe. It is connected to the. Support members 310 are erected on both sides of each electrode 302, and contact members 312 that are in contact with the surface (lower surface) of the substrate W are installed on the upper surfaces of the respective support members 310. A through hole 314 communicating with the flow path is formed inside the support 310 and the contact member 312, and a through hole 316 communicating with the flow path is formed inside the electrode 302, and the through holes 314 and 316 are formed. Then, a liquid such as pure water is supplied between the substrate W and the electrode 302.

  As the contact member 312, a CMP pad, a fixed abrasive pad, a PVA sponge, or the like can be used. An ion exchanger or a material containing an ion exchanger may be used.

In this electrode portion 246a, electrolytic processing is performed while the substrate W held by the substrate holding portion 242 (see FIGS. 8 and 9) is brought into contact with the surface of the contact member 312 of the electrode portion 246a. At the time of processing, the distance D between the substrate W and the electrode 302 is set to be 0.05 μm or more and 50 μm or less without the substrate W and the electrode 302 being in contact with each other.
During the electrolytic processing, for example, pure water, ultrapure water, or a liquid having an electric conductivity of 500 μS / cm or less is supplied between the substrate W and the electrode 302.

  According to the present invention, even if an initial step is formed on the surface of a metal film (conductive film) such as a copper film as a wiring material, the surface of the metal film is flattened over the entire surface at a sufficient processing speed. By processing, the surface of the metal film can be planarized more easily and at high speed.

  FIG. 17 is a plan view showing a flattening apparatus according to another embodiment of the present invention. As shown in FIG. 17, the planarization apparatus includes a pair of load / unload units 130, a reversing machine 132 that reverses the substrate W, a first polishing unit 134, and a second polishing unit 136. An electrolytic processing apparatus 138 and a cleaning unit 140 for cleaning and drying the electrolytic processed substrate W are provided. These devices are arranged in series, and a transfer robot 142 as a transfer device that transfers the substrate W between these devices and transfers it is arranged in parallel with these devices. Further, the flattening device includes a load / unload unit 30 that controls the voltage applied between the machining electrode and the feeding electrode, or the current flowing between them, or detects the table current. Is provided adjacent to.

  FIG. 18 is a plan view schematically showing the electrolytic processing apparatus (polishing apparatus) 138 shown in FIG. As shown in FIG. 18, the electrolytic processing apparatus 138 includes an arm 240 that can move up and down and can reciprocate along a horizontal plane, and a free end of the arm 240, similar to the electrolytic processing apparatus 36 shown in FIGS. 8 and 9. , And a movable frame 244 to which the arm 240 is attached. The substrate holding portion 242 holds the substrate W by suction.

  A vertical movement motor 250 is installed above the movable frame 244, and the arm 240 moves up and down as the vertical movement motor 250 is driven. The movable frame 244 itself is also attached to a ball screw 254 extending in the horizontal direction, and the movable frame 244 and the arm 240 reciprocate along the horizontal plane as the reciprocating motor 256 is driven. The substrate holding part 242 is connected to a rotation motor 258 installed at the free end of the arm 240, and rotates (autorotates) as the rotation motor 258 is driven.

  Below the substrate holding part 242, a rectangular first electrode part 246 b that constitutes the first polishing part 134 together with the substrate holding part 242 and a rectangular first electrode part that constitutes the second polishing part 136 together with the substrate holding part 242. A two-electrode portion 246c is disposed. The substrate holding part 242 moves between a position just above the first electrode part 246b and a position just above the second electrode part 246c.

  The first electrode portion 246b and the second electrode portion 246c perform scroll motion (translation rotation motion) by driving the hollow motor, similarly to the electrode portion 246 of the electrolytic processing apparatus 36 shown in FIGS.

  The first electrode portion 246b has the same configuration as that of the electrode portion 246 of the electrolytic processing apparatus 36 shown in FIGS. 8 and 9, and as shown in FIG. 19, ion exchange that covers each electrode 286 with a certain amount of force on the substrate W. The substrate W is pressed against the body 290 to contact the upper surface of the contact member 298. Thereby, the contact member 298 receives the pressing force of the substrate W, the contact area between the substrate W and the ion exchanger 290 is not changed, the substrate W is prevented from being tilted, and the contact area is made uniform. Can be realized.

  Each ion exchanger (processing member) 290 of the first electrode portion 246b presses the substrate W against the ion exchanger 290 with a certain force to bring the substrate W into contact with the upper surface of the contact member 298. Is in contact with the surface of the convex portion 6b of the copper film (metal film) 6 in the pattern portion P shown in FIG. 21A, and continues to contact the surface of the convex portion 6b during processing, as shown in FIG. The protrusion 6b is selectively polished to have elasticity that can flatten the surface of the copper film 6 in the pattern portion P.

  In the first polishing unit 134 having such a configuration, as shown in FIG. 19, the substrate W held by the substrate holding unit 242 is brought into contact with the upper surface of the contact member 298 while the ion exchanger of the first electrode unit 246b. The ion exchanger 290 is also brought into contact with the surface of the convex portion 6b of the copper film (metal film) 6 in the pattern portion P shown in FIG. 21A. The first electrode unit 246b is scrolled while rotating the substrate W held by the substrate holding unit 242, and at the same time, pure water or ultrapure water is supplied between the substrate W and the electrode member 282 from the communication hole 296a of the support 296. In addition, pure water or ultrapure water is included in the ion exchanger 290 through the through holes 300 of the electrodes 286. Then, a predetermined voltage is applied between the processing electrode 286a and the feeding electrode 286b by the power source 248 (see FIG. 18), and the processing electrode (cathode) is generated by hydrogen ions or hydroxide ions generated by the ion exchanger 290. In 286a, the first polishing (electrolytic processing) of the copper film (conductive film) 6 deposited on the surface of the substrate W is performed.

  At this time, particularly in the pattern portion P where the convex portions are concentrated, the electrolytic strength is higher than that in the field portion F, so that the supply amount of the reactive species ions is larger than that in the field portion F, and the polishing rate of the copper film 6 in the pattern portion P is It becomes larger than the polishing rate of the copper film 6 in the part F.

  An electrolytic solution obtained by adding an ionic reaction accelerator to pure water, ultrapure water, or the like may be used. The ionic reaction accelerator is concentrated on the portion where the electric field strength is strong, that is, the upper end of the convex portion 6b of the copper film 6 in the pattern portion P, and the polishing rate of the convex portion 6b of the copper film 6 in the pattern portion P is further increased. Thereby, a sufficient polishing (processing) speed difference of the copper film 6 in the pattern portion P and the field portion F can be obtained.

  In particular, the first polishing by the first polishing unit 134 is continued until the initial level difference on the surface of the copper film 6 in the pattern portion P is eliminated. For this reason, when the polishing rate of the copper film 6 in the first polishing is low, the thickness of the copper film 6 that can be used to eliminate the level difference between the surface of the copper film 6 in the pattern portion P and the field portion F in the second polishing described below. Becomes smaller. Therefore, in the first polishing, the polishing rate of the copper film 6 in the pattern portion P is increased at least twice as much as the polishing rate of the copper film 6 in the field portion F, and the pattern portion P and the field portion F in the first polishing. It is desirable to increase the speed at which a step is formed between the two. This requirement can be met by adding an ionic reaction accelerator to an electrolytic solution (liquid) such as pure water or ultrapure water.

  FIG. 20 shows a main part of the second electrode portion 246 c constituting the second polishing portion 136. The second electrode portion 246c is different from the first electrode portion 246b in that an ion exchanger 290a having high rigidity and less elastic deformation is used as a processing member, and a support member 296 having a contact member 298 attached on the upper surface thereof. When the height is further increased and the substrate W is pressed with a certain amount of force and brought into contact with the upper surface of the contact member 298, the ion exchanger 290a has a copper film (metal film) 6 in the pattern portion P shown in FIG. 21B. It is the point which was made not to touch the surface of. The ion exchanger 290a may be in contact with the surface of the copper film 6 in the field portion F.

  In the operation of the second polishing unit 136, as shown in FIG. 20, the substrate W held by the substrate holding unit 242 is brought into contact with the surface of the contact member 298 of the second electrode unit 246c. The ion exchanger 290a does not contact the surface of the copper film (metal film) 6 in the pattern portion P shown in FIG. 21B. The ion exchanger 290a may be in contact with the surface of the copper film (metal film) 6 in the field portion F shown in FIG. 21B.

  Similar to the first polishing unit 134 described above, the second electrode unit 246c is scrolled while rotating the substrate W held by the substrate holding unit 242. At the same time, pure water or ultrapure water is supplied between the substrate W and the electrode member 282. Further, pure water or ultrapure water is included in the ion exchanger 290a, and between the processing electrode 286a and the power supply electrode 286b. A predetermined voltage is applied to perform electrolytic processing (polishing) of the copper film (conductive film) 6 deposited on the surface of the substrate W at the processing electrode (cathode) 286a.

  During polishing, the ion exchanger 290a is not in contact with the surface of the copper film (metal film) 6 in the pattern portion P shown in FIG. 21B, and therefore the polishing rate of the copper film 6 in the pattern portion P is reduced. Therefore, the copper film 6 in the field portion F is selectively polished. As a result, as shown in FIG. 21C, the step between the pattern portion P and the field portion F remaining on the surface of the copper film 6 is eliminated, and the surface of the copper film 6 is flattened.

  Thus, the first step mainly eliminates the initial step on the surface of the copper film 6 in the pattern portion P, and then the second polishing mainly forms the pattern portion P between the surface of the copper film 6 and the field portion F. By eliminating the step between them, the surface of the copper film 6 on the entire surface of the substrate W can be polished flat.

During the second polishing, a resistance forming process for forming a resistance on the surface of the copper film 6 in the pattern portion P is performed, and the polishing rate of the copper film (conductive film) 6 in the pattern portion P is delayed, whereby the polishing rate of the field portion F It is preferable to have a larger polishing rate difference between In this resistance forming treatment, a treatment solution (electrolytic solution) obtained by adding an oxidizing agent (H ₂ O ₂ , O ₃ or the like) or a complexing agent to pure water or ultrapure water or the like is used. The surface of the copper film 6 is made passivated or complexed to suppress the reaction species ions from reaching the surface of the copper film 6 in the pattern portion P.

  As another treatment, a treatment solution (electrolytic solution) in which an additive having an insulating property is introduced into pure water, ultrapure water or the like is used, and as shown in FIG. There is a process of covering the surface with an additive (insulator) 10 to prevent reactive species ions from reaching the surface of the copper film 6 in the pattern portion P.

  As another treatment, as a treatment solution (electrolytic solution), an additive that suppresses the reaction between the reactive species ions and the copper film 6 in pure water or ultrapure water, for example, an anticorrosive agent such as BTA (benzotriazole). There is a process of using the introduced material and suppressing the reaction between the reactive species ions and the copper film 6 itself.

  These treatments, in particular, passivation or complexation of the surface of the copper film 6 or coating with the additive (insulator) 10 is preferably performed only on the pattern portion P, but temporarily performed on the field portion F. However, the strength may be such that the ion exchanger (processing member) 290a or the contact pressure of the contact member 298 can be removed or removed from the field portion F by the contact pressure. By preventing the ion exchanger 290a from coming into contact with the pattern portion P during the second polishing, the resistance of the passivated film, complexed material, insulator, or the like formed on the surface of the copper film 6 in the pattern portion P can be reduced. It is not removed by contact with the ion exchanger 290a. On the other hand, the contact member 298 is brought into contact with the field portion F during the second polishing, so that the resistance of the passivation film or the like formed on the surface of the copper film 6 in the field portion F is removed by the contact pressure of the contact member 298. be able to.

In the case where the contact member 298 is not provided, the ion exchanger 290a is brought into contact with the field portion F during the second polishing so that a passivation film or the like formed on the surface of the copper film 6 in the field portion F can be obtained. The resistance can be removed by the contact pressure of the ion exchanger 290a.
In this example, the resistance forming process of the pattern portion P is performed simultaneously with the second polishing, but may be performed before the second polishing.

  In the operation of the planarization apparatus in this embodiment, the substrate holding part 242 holding the substrate W is moved to the first polishing position directly above the first electrode part 246b. Next, the substrate holding portion 242 is lowered, and the substrate W held by the substrate holding portion 242 is brought into contact with the contact member 298 of the first electrode portion 246b and the surface of the ion exchanger 290, thereby causing the ion exchanger 290 to move. 21A, the surface of the convex portion 6b of the copper film (conductive film) 6 in the pattern portion P is brought into contact. Thereafter, pure water or ultrapure water to which an ionic reaction accelerator is added as necessary between the substrate W and the ion exchanger 290 while rotating the substrate W and simultaneously scrolling the first electrode portion 246b. Supply.

  A predetermined voltage is applied between the processing electrode 286a and the power supply electrode 286b by the power source 248, and the hydrogen ions or hydroxide ions generated by the ion exchanger 290 cause the processing electrode (cathode) 286a to First polishing (electrolytic processing) is performed in which the polishing rate of the copper film 6 is larger than the polishing rate of the copper film 6 in the field portion F. Then, as shown in FIG. 21B, the first polishing is finished when the convex portion 6b of the copper film 6 in the pattern portion P is selectively polished to eliminate the initial step.

  In this example, a current (table current) supplied to scroll the machining table 284 is detected by the control unit 144 to detect the end point of the first polishing. That is, as the first polishing progresses, when the step on the surface of the copper film 6 is eliminated and flattened, the contact area between the copper film 6 and the ion exchanger (processing member) 290 increases. As a result, the table current increases as shown in FIG. When the table current is detected and becomes larger than a predetermined value, the end point of the first polishing can be set.

  The end point of the first polishing may be detected by image recognition. Assuming that the surface of the copper film 6 is a change in the pattern image, as shown in FIG. 24A, the pattern shape 12 is clearly captured as shown in FIG. Then, the pattern shape 12 is gradually disappeared. Therefore, for example, the image of the copper film 6 being processed is recognized by a camera disposed on the processing table 284 (see FIG. 10), or overhanging from the processing table 284 during processing by the camera disposed on the side of the processing table 284. The end point of the first polishing can be detected by recognizing the image of the copper film 6 of the substrate W. The end point of the first polishing may be detected by time management.

  After the first polishing is completed, the processing electrode 286a of the first electrode portion 246b and the power source 248 of the power supply electrode 286b are disconnected, and the rotation of the substrate holding portion 242 and the scrolling motion of the first electrode portion 246b are stopped. After the substrate holding part 242 is lifted and moved to the second polishing position directly above the second electrode part 246c, the substrate W held by the substrate holding part 242 is lowered and the contact member 298 of the second electrode part 246c is moved. Touch the surface. However, as shown in FIG. 20, the ion exchanger 290a is not in contact with the surface of the copper film (conductive film) 6 in the pattern portion P shown in FIG. 21B. In this state, while supplying pure water or ultrapure water to which an oxidizing agent, a complexing agent or an additive having an insulating property is added as necessary between the substrate W and the ion exchanger 290a, Similarly, the second polishing (electrolytic processing) of the surface of the copper film 6 is performed. The first polishing (electropolishing) and the second polishing (electropolishing) may be performed on the same electrode portion.

  During the second polishing, since the ion exchanger 290a is not in contact with the surface of the copper film (conductive film) 6 in the pattern portion P shown in FIG. 21B, the polishing rate of the copper film 6 in the pattern portion P decreases. It becomes slower than the field portion F, and further, if necessary, a resistance forming process is performed to form a resistance on the surface of the copper film 6 in the pattern portion P, and the polishing rate of the copper film (conductive film) 6 in the pattern portion P is increased. By further delaying, mainly only the copper film 6 in the field portion F is selectively polished. As a result, as shown in FIG. 21C, the step between the pattern portion P and the field portion F remaining on the surface of the copper film 6 is eliminated, and the surface of the copper film 6 is flattened.

  In the second polishing, for example, the processing amount can be determined by detecting a change in frictional force caused by removing the unevenness, and the processing end point can be detected.

  After the second polishing is completed, the processing electrode 286a of the second electrode portion 246c and the power source 248 of the power supply electrode 286b are disconnected, and the rotation of the substrate holding portion 242 and the scroll movement of the second electrode portion 246c are stopped. Thereafter, the substrate holding unit 242 is raised, the arm 240 is moved, and the substrate W is delivered to the transport robot 142. The transport robot 142 transports the substrate W to the reversing machine 132 and reverses it as necessary, and then returns the substrate W to the cassette of the load / unload unit 130.

  In the above example, the common substrate holding unit 242 is used, the substrate holding unit 242 and the first electrode unit 246b use the first polishing unit 134, and the substrate holding unit 242 and the second electrode unit 246c use the second polishing unit. In the example shown in FIG. 136, the first polishing and the second polishing may be performed by separate electrolytic processing apparatuses.

Further, the processing table may be a cartridge type, and the processing table may be arbitrarily replaced during polishing while the substrate holding unit 242 holds the substrate W.
As the first electrode portion 246b and the second electrode portion 246c, the electrode portion 246a shown in FIG. 16 is used, and the substrate W and the electrode 302 are arranged so that the distance D is 0.05 μm or more and 50 μm or less without being in contact with each other. Different liquids (electrolytic solutions) may be supplied between the first polishing and the second polishing.

  That is, when performing the first polishing, for example, pure water, ultrapure water, or a liquid having an electric conductivity of 500 μS / cm or less and an ionic reaction accelerator added are supplied between the substrate W and the electrode 302. . 21A, the first polishing can be performed in which the polishing rate of the copper film (metal film) 6 in the pattern portion P is higher than the polishing rate of the copper film 6 in the field portion F. That is, when the electrical conductivity of the liquid is high, the polishing of the copper film 6 in the pattern portion P and the field portion F is both isotropic, and there is no difference in the polishing rate of the copper film 6 in the pattern portion P and the field portion F. However, by making the electrical conductivity of the liquid small, for example, 500 μS / cm or less, these polishings are brought close to anisotropy so that the polishing rate of the copper film 6 in the pattern portion P and the field portion F is different. Can be. In addition, the ionic reaction accelerator is concentrated on the portion where the electric field strength is strong, that is, the upper end of the convex portion 6b of the copper film 6 in the pattern portion P, thereby increasing the polishing rate of the copper film 6 in the pattern portion P. .

When performing the second polishing, between the substrate W and the electrode 302, for example, pure water, ultrapure water, or a liquid having an electric conductivity of 500 μS / cm or less is optionally added with an oxidizing agent (H ₂ O ₂ , O ₃ etc.) or a complexing agent added, an insulating additive introduced, or an additive introduced to suppress the reaction between reactive species ions and the copper film 6 is supplied, thereby The resistance forming process for the pattern portion P is performed simultaneously with the second polishing. By the resistance forming process, the polishing rate of the copper film (metal film) 6 in the pattern portion P shown in FIG. 21B is delayed to have a larger polishing rate difference from the polishing rate of the copper film 6 in the field portion F. Can do.

  At this time, even if a resistance such as passivation, complexation, or coating with an additive (insulator) is formed on the surface of the copper film 6 in the field portion F, the resistance is in contact with the contact member 312. It is removed from the field part F by pressure.

  Even in this example, while the substrate W held by the substrate holding unit 242 is in contact with the contact member 312 of the electrode unit 246a, the electrode unit 246a is rotated while the substrate W held by the substrate holding unit 242 is rotated. Scroll. At the same time, for example, a liquid (electrolytic solution) having an electric conductivity of 500 μS / cm or less added with an ionic reaction accelerator is supplied between the substrate W and the electrode 302, and between the processing electrode 302a and the power supply electrode 302b. A predetermined voltage is applied to perform first polishing of the copper film (conductive film) 6 deposited on the surface of the substrate W in the processing electrode (cathode) 302a.

  Then, while the substrate W held by the substrate holding unit 242 is in contact with the contact member 312 of the electrode unit 246a, the electrode unit 246a is scrolled while rotating the substrate W held by the substrate holding unit 242. At the same time, a liquid (electrolytic solution) having an electric conductivity of 500 μS / cm or less is added between the substrate W and the electrode 302 as necessary, to which an oxidizing agent, a complexing agent, an insulating additive or the like is added. Second polishing (electrolytic processing) of the copper film (conductive film) 6 deposited on the surface of the substrate W in the processing electrode (cathode) 302a by applying a predetermined voltage between the processing electrode 302a and the feeding electrode 302b. I do.

  Although the embodiments of the present invention have been described so far, it is needless to say that the present invention is not limited to the above-described embodiments, and may be implemented in various forms within the scope of the technical idea.

  The present invention is used to process and planarize the surface of a metal film formed on the surface of the substrate while being embedded in a fine wiring recess provided on the surface of the substrate.

1A to 1C are views showing an example of manufacturing a copper wiring board in the order of steps. 2A to 2D are diagrams schematically showing a state in which a copper film as a wiring material is processed by a conventional electrolytic processing method. 3A to 3C are diagrams schematically illustrating another state in which a copper film as a wiring material is polished by a conventional electrolytic processing method. 4A to 4C are diagrams schematically showing an ideal state in which a copper film as a wiring material is polished by an electrolytic processing method. FIG. 5 is a plan view showing the flattening apparatus in the embodiment of the present invention. FIG. 6 is a schematic diagram of the resist processing apparatus (coating material processing apparatus) of the planarization apparatus shown in FIG. 7A to 7C are views showing a state when the concave portion of the copper film is covered with a coating material using the resist processing apparatus shown in FIG. FIG. 8 is a plan view of the electrolytic processing apparatus of the planarization apparatus shown in FIG. FIG. 9 is a longitudinal sectional view of the electrolytic processing apparatus shown in FIG. 10 is a longitudinal sectional view of an electrode portion of the electrolytic processing apparatus shown in FIG. FIG. 11 is a cross-sectional view showing the main part when processing is performed with the electrode part of the electrolytic processing apparatus shown in FIG. 12A to 12D are diagrams schematically illustrating a state when a copper film as a wiring material is processed by the planarization method according to the embodiment of the present invention. FIG. 13 is a schematic diagram showing another example of a resist processing apparatus. 14A and 14B are views showing a state when the concave portion of the copper film is coated with a coating material using the resist processing apparatus shown in FIG. 15A to 15D are diagrams schematically showing a state when a copper film as a wiring material is processed by the planarization method according to another embodiment of the present invention. FIG. 16 is a cross-sectional view showing a main part of another electrode part of the electrolytic processing apparatus. FIG. 17 is a plan view showing a planarization apparatus according to another embodiment of the present invention. FIG. 18 is a plan view of the electrolytic processing apparatus of the planarization apparatus shown in FIG. FIG. 19 is a cross-sectional view showing a main part when polishing is performed by the first electrode portion (first polishing portion) of the electrolytic processing apparatus shown in FIG. FIG. 20 is a cross-sectional view showing the main part when the second electrode part (second polishing part) of the electrolytic processing apparatus shown in FIG. 18 is being polished. 21A to 21C are diagrams schematically showing a state when a copper film as a wiring material is polished by the planarization method of the present invention. FIG. 22 is a diagram schematically showing a state in which the surface of the copper film in the pattern portion is covered with an additive (insulator). FIG. 23 is a graph showing the relationship between the table current and the polishing time when the first polishing is performed by the planarization method of the present invention. 24A and 24B are graphs showing a state in which the pattern shape is changed by the first polishing.

Claims (28)

In processing and planarizing a metal film surface having an initial step formed on a workpiece,
Only the recesses that form the initial step on the surface of the metal film are coated with a solid or paste-like coating material,
A planarization method comprising processing the surface of the metal film by electrolytic processing without using an abrasive.   The planarization method according to claim 1, wherein the coating material remaining on the surface of the metal film without being processed by electrolytic processing is removed, and the surface of the metal film is further processed. The planarization method according to claim 1, wherein the covering material is made of an insulating material having a resistivity of 10 ⁶ Ω · cm or more, or a conductive material having a resistivity of 10 ³ Ω · cm or less.   After the coating material is applied to the entire surface of the metal film, only the coating material located on the convex portions forming the initial step on the surface of the metal film is removed to form the initial step on the surface of the metal film. The planarization method according to claim 1, wherein only the concave portion to be covered is covered with a coating material.   2. The planarization according to claim 1, wherein the coating material is selectively applied to the recesses on the surface of the metal film, and only the recesses forming the initial step on the surface of the metal film are covered with the coating material. Method. A voltage is applied between the machining electrode close to the metal film of the workpiece and the power feeding electrode that feeds the metal film,
Supplying a liquid between the workpiece on which a processing member exists and at least one of the processing electrode or the feeding electrode;
The planarization method according to claim 1, wherein the metal film surface is processed by the electrolytic processing by relatively moving the workpiece and at least one of the processing electrode or the feeding electrode.   The planarization method according to claim 6, wherein the processing member is made of an ion exchanger or a material containing an ion exchanger.   The metal film surface is processed by the electrolytic processing by bringing a contact member disposed on a side of the processing electrode and / or the feeding electrode into contact with the metal film surface of the workpiece. 6. The flattening method according to 6. A voltage is applied between the machining electrode close to the metal film of the workpiece and the power feeding electrode that feeds the metal film,
Supplying a liquid between the workpiece and at least one of the processing electrode or the feeding electrode;
The planarization method according to claim 1, wherein the metal film surface is processed by the electrolytic processing by relatively moving the workpiece and at least one of the processing electrode or the feeding electrode.   The metal film surface is processed by the electrolytic processing by bringing a contact member disposed on a side of the processing electrode and / or the feeding electrode into contact with the metal film surface of the workpiece. The planarization method according to 9. A coating material processing apparatus for coating only the recesses forming the initial step on the metal film surface with a solid or paste-like coating material;
A planarization apparatus comprising: an electrolytic processing apparatus that processes the surface of the metal film by electrolytic processing without using an abrasive.   The planarization apparatus according to claim 11, wherein the coating material processing apparatus is a resist processing apparatus. In polishing and planarizing the metal film surface having the pattern part and the field part formed on the workpiece,
The first polishing of the metal film surface is performed in a state where the polishing rate of the metal film in the pattern portion is higher than the polishing rate of the metal film in the field portion,
A planarization method comprising performing the second polishing of the metal film surface in a state where the polishing rate of the metal film in the field portion is higher than the polishing rate of the metal film in the pattern portion.   The planarization method according to claim 13, wherein at least one of the first polishing and the second polishing is performed by electrolytic processing. A voltage is applied between the processing electrode brought close to the metal film surface of the workpiece and the power supply electrode that feeds the metal film,
Supplying a liquid between the workpiece and at least one of the processing electrode or the feeding electrode, wherein a processing member exists;
The planarization method according to claim 13, wherein the first polishing and the second polishing are performed by relatively moving the workpiece and at least one of the processing electrode or the feeding electrode.   The planarization method according to claim 15, wherein the processing member is made of an ion exchanger or a material containing an ion exchanger.   16. The first polishing is performed by bringing the pattern portion and the processing member into contact with each other, and the second polishing is performed with the pattern portion and the processing member being in a non-contact state. Flattening method.   16. The pattern portion and the processing member are brought into contact with each other to perform the first polishing, and the resistance forming process of the pattern portion is performed before or simultaneously with the second polishing. Flattening method.   The planarization method according to claim 15, wherein the second polishing is performed in a state where the pattern portion and the processing member are not in contact with each other while performing resistance forming processing on the pattern portion.   The contact member disposed in the vicinity of the processing electrode and / or the feeding electrode is brought into contact with the surface of the metal film of the workpiece to perform at least one of the first polishing and the second polishing. Item 15. The planarization method according to Item 15. A voltage is applied between the processing electrode brought close to the metal film of the workpiece and the feeding electrode that feeds the conductive film,
Supplying a liquid between the workpiece and at least one of the processing electrode or the feeding electrode;
The planarization method according to claim 13, wherein the first polishing and the second polishing are performed by relatively moving the workpiece and at least one of the processing electrode or the feeding electrode.   The planarization method according to claim 21, wherein a resistance forming process is performed on the pattern portion before the second polishing or simultaneously with the second polishing.   The planarization method according to claim 21, wherein the second polishing is performed with the pattern portion and the processing electrode in a non-contact state while performing the resistance forming process of the pattern portion.   The contact member disposed in the vicinity of the processing electrode and / or the feeding electrode is brought into contact with the metal film surface of the workpiece to perform at least one of the first polishing and the second polishing. 22. The planarization method according to 21.   The flat surface according to claim 21, wherein at least one of the first polishing and the second polishing is performed by setting a distance between the processing electrode and the metal film surface of the workpiece to be 0.05 μm or more and 50 μm or less. Method.   The planarization method according to claim 13, wherein the end point of the first polishing is detected by time management, detection of a table current, or image recognition. First polishing for polishing a metal film surface having a pattern portion and a field portion formed on a workpiece in a state where the polishing rate of the metal film in the pattern portion is higher than the polishing rate of the metal film in the field portion. And
A planarization apparatus comprising: a second polishing unit that polishes the surface of the metal film in a state where the polishing rate of the metal film in the field portion is higher than the polishing rate of the metal film in the pattern portion.   28. The planarization apparatus according to claim 27, wherein at least one of the first polishing unit and the second polishing unit is polished by electrolytic processing.

Images