JP2004276219A - Electrolytic machining liquid, electrolytic machining device, and wiring machining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolytic machining liquid reducing a polishing speed of copper, which is a wiring layer, up to at least a speed equivalent to that of a barrier layer and capable of planarizing the surface of a copper film flush with the surface of an insulating layer at electrolytic polishing time of a surface of a substrate. <P>SOLUTION: An electrolytic machining liquid of the present invention functions to planarize the surface of a substrate through subjecting at least either of a barrier layer formed on the substrate or a wiring layer mainly composed of copper to electrolytic polishing, and such an electrolytic machining liquid comprises either of alkaline solution or fluorine series solution and inhibitor. The inhibitor is absorbed by the surface of the copper, thereby suppressing the copper from dissolving as ions. Dissolution of copper is selectively accelerated in a part from which the inhibitor absorbed by the surface is removed by polishing, thereby preferentially removing wiring layers from a projection part, and accelerating the planarization in a process of electrolytic polishing. In addition, the electrolytic polishing is further preferably conducted if an oxidizing agent and abrasive grains are included. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrolytic processing liquid used for electrolytic polishing, an electrolytic processing apparatus, and a wiring processing method using the electrolytic processing liquid. More specifically, the present invention relates to an electrolytic processing solution, an electrolytic processing apparatus, and a wiring processing method using the electrolytic processing solution used for electrolytic polishing for removing unnecessary portions of a wiring layer and a barrier layer of a semiconductor integrated circuit or the like and planarizing the surface. .
[0002]
[Prior art]
Aluminum and aluminum alloys have conventionally been used as metal materials for internal wiring of semiconductor integrated circuit devices, but copper having lower electric resistance and electromigration resistance has been used today.
[0003]
In order to form copper wiring, copper as a wiring material or a barrier layer for preventing copper diffusion is buried in the contact holes and wiring grooves provided in the insulating layer formed on the substrate. A damascene method (see Non-Patent Document 1) for removing and flattening the deposited unnecessary portion by CMP (Chemical and Mechanical Polishing) is used.
[0004]
FIGS. 5A to 5D show an example of a process for processing a copper wiring by a damascene method. FIG. 5 (a) shows an example in which a SiO 2 ₂ An insulating layer 2 made of a film, a low-k material or the like is deposited, and a contact hole 3 and a wiring layer groove 4 are formed in the insulating layer by, for example, lithography etching, and a barrier layer made of TaN or the like is formed thereon. 5 shows a state in which a seed layer 6 is formed thereon as a power supply layer for electrolytic plating. As the barrier layer 5 for preventing copper diffusion into the insulating layer 2, a film of a Ta / TaN mixed film, TiN, WN, SiTiN, CoWP, CoWB or the like is used. FIG. 5 shows a case where the conductive layer 1a is an impurity diffusion region formed in the semiconductor substrate 1, but may be a wiring layer formed on the semiconductor substrate 1. In the latter case, the conductive layer 1a is sandwiched between insulating regions, and a planarization process is performed so that the surface is substantially the same height as the insulating region and the surface is substantially flat. Here, an insulating layer 2, a contact hole 3, a wiring groove 4, and a barrier layer 6 are formed on a semiconductor substrate 1 or the like, and a wiring layer 7 is formed in some cases. It is referred to as W, and a semiconductor substrate or the like as a base material on which devices, wirings, and the like are mounted is referred to as an original substrate 1 (or a semiconductor substrate 1 or the like) to be distinguished.
[0005]
Next, as shown in FIG. 5B, for example, a wiring layer 7 made of a copper film is deposited on the surface of the substrate W. Copper is filled in the contact hole 3 and the wiring groove 4 of the semiconductor substrate 1 and a copper film 7 is deposited on the insulating layer 2. Thereafter, as shown in FIG. 5C, the wiring layer 7 and the seed layer 6 are removed by CMP using an abrasive slurry to expose the barrier layer 5 over the entire surface. Subsequently, as shown in FIG. 5D, the barrier layer 5 and the wiring groove are formed so that the surface of the copper film 7 filled in the contact hole 3 and the wiring groove 4 and the surface of the insulating layer 2 are substantially flush with each other. The polishing process is completed by polishing the copper film 7 on 4. Thus, a wiring layer 7 made of copper is formed on the semiconductor substrate 1.
[0006]
By the way, tantalum Ta is insoluble in acids other than hydrofluoric acid, and there is a solution in which hydrofluoric acid alone or nitric acid is mixed. Since tantalum oxide is dissolved in hydrofluoric acid and an alkaline solution, a method of oxidizing tantalum and then dissolving it in an alkaline solution is considered. Examples of the combination of an alkali and an oxidizing agent include a method using 50% potassium hydroxide and copper chloride (see, for example, Patent Document 1) and a method of anodizing tantalum and then dissolving an oxide film with an aqueous alkali solution (for example, Patent Document 2). Reference).
Further, in polishing in a semiconductor manufacturing process, there is a method of processing a metal film by combining electric field polishing and mechanical polishing. For a copper film, a convex portion of the metal film is formed more in comparison with planarization of the metal film by CMP. It is possible to efficiently planarize while selectively removing (for example, see Patent Document 3).
[0007]
[Patent Document 1] Japanese Patent Publication No. 49-1138 (page 69, right column)
[Patent Document 2] JP-A-49-125239 (page 2)
[Patent Document 3] Japanese Patent Application Laid-Open No. 2001-77117 (paragraphs, 0056-0060, 0073, FIGS. 17-18, etc.)
[Non-Patent Document 1] C. Andricacos, C, Uzoh, J. et al. O. Dukovic, J .; Horkaus & H. Deligianni: "Damascene copper electroplating for chip inter-connection", IBM J.C. Res. Developerm. , 42, 567 (1998).
[0008]
[Problems to be solved by the invention]
By the way, this damascene method has the following problems. To ensure that copper is buried in the wiring groove 4 and the like, it is necessary to deposit an excessive copper film 7 on the surface of the insulating layer 2, and at this time, irregularities are necessarily formed on the surface of the copper film 7. You. When the excess copper film 7 is polished while being planarized, the polishing pressure is increased, so that the processing pressure has to be increased by the conventional CMP, and the cross section of the wiring is dish-shaped. There is also a problem that an erosion or the like is excessively polished also in the insulating film, resulting in a decrease in flatness.
[0009]
In recent years, conventional CVD-SiO has been used as an interlayer insulating material. ₂ An organic / inorganic material called a low-k material having a lower dielectric constant than a film has been proposed. These are porous, soft, and have a mechanical strength of SiO 2 to lower the dielectric constant. ₂ Lower than membrane. Therefore, in the CMP process, the low-k material and the substrate are easily separated, and it has been difficult to apply the process.
Further, in the CMP process, the slurry is expensive and consumes a large amount, and the waste liquid is expensive. Therefore, it has been desired to reduce the use of the slurry.
[0010]
By the way, until the excess copper film 7 is removed and the barrier layer is exposed, an electrolytic polishing method using an electrolytic processing solution has been considered in order to exclusively promote the processing of copper. In the electropolishing method, the metal film can be efficiently removed with a lower load as compared with the CMP.
[0011]
However, at the stage where the barrier film 7 is exposed, the polishing rate of the barrier layer 5 exposed on the entire surface layer during polishing is lower than that of copper due to its hardness and chemical stability. In the exposed portion, copper is preferentially removed and dishing is likely to occur. Therefore, in the processing method after the exposure of the barrier layer, realization of an electrolytic processing liquid and an electrolytic processing apparatus that can uniformly process the copper film and the barrier layer at least at the same speed has been desired. Further, in a wiring forming process of a semiconductor integrated circuit or the like, a wiring processing method capable of obtaining a wiring structure having excellent flatness has been desired.
[0012]
In order to solve the above problem, the present invention slows down the processing speed of copper as a wiring layer to at least a speed equivalent to that of a barrier layer during electrolytic polishing of a substrate surface, so that the surface of the copper film and the surface of the insulating layer are substantially separated. To provide an electrolytic processing liquid that can be planarized so as to be on the same plane, and to provide an electrolytic processing apparatus capable of performing electrolytic polishing using such an electrolytic processing liquid, and further, in a wiring forming process of a semiconductor integrated circuit or the like, An object of the present invention is to provide a wiring processing method capable of obtaining a wiring structure having excellent flatness using an electrolytic processing liquid.
[0013]
[Means for Solving the Problems]
In order to solve the above problem, the electrolytic processing liquid according to claim 1 is configured to electrolytically polish at least one of the barrier layer 5 formed on the substrate W or the wiring layer 7 containing copper as a main component, and the surface of the substrate W is electropolished. Is an electrolytic processing liquid 9 for flattening, which contains one of an alkaline solution or a fluorine-based solution and an inhibitor. Here, the phrase “having copper as a main component” means that it is not limited to pure copper, and may contain impurities, additives, and some mixtures, or a compound containing copper as a main component. It is. The wiring layer 7 includes the seed layer 6. This makes it possible to suppress the processing speed of the wiring layer 7 during electrolytic polishing of the surface of the substrate W, and to obtain a surface of the substrate W having excellent flatness.
Here, the electrolytic processing liquid 9 for flattening the surface of the substrate W by electrolytically polishing at least one layer of the barrier layer 5 or the wiring layer 7 containing copper as a main component formed on the substrate W is typically Is an electrolytic processing liquid for flattening the substrate surface by electrolytically polishing a wiring layer mainly composed of copper formed on the substrate, or a barrier layer formed on the substrate and a wiring layer mainly composed of copper. Say. In addition, the phrase “containing either one of the alkaline solution and the fluorine-based solution” means that only one of the alkali solution and the fluorine-based solution is contained and the other is not contained. In addition, an inhibitor typically refers to an inhibitor that adsorbs to the wiring layer and suppresses the dissolution of copper.
[0014]
The electrolytic processing liquid according to claim 2 is the electrolytic processing liquid according to claim 1, wherein the inhibitor is benzotriazole or a derivative thereof (eg, 5-methylbenzotriazole, carboxylbenzotriazole), benzimidazole or a derivative thereof, and phenacetin. Quinaldic acid, polyvinyl alcohol, polyvinylpyrrolidone, acetonitrile, acrylonitrile, phenylacetonitrile, or amines (eg, methylamine, ethylamine, dimethylamine, diethylamine, ethylenediaminetetraacetic acid). Here, benzotriazole and the like are counted as one type. These inhibitors are adsorbed on the copper surface to suppress the dissolution of copper as ions. Then, the dissolution of copper is selectively promoted in the portion where the inhibitor adsorbed on the surface is removed by polishing. As a result, the wiring layer 7 is preferentially removed from the protrusions, and flattening is promoted in the course of electrolytic polishing.
[0015]
The electrolytic processing liquid according to claim 3 is the electrolytic processing liquid according to claim 1 or 2, wherein the alkaline solution is an inorganic alkali such as potassium hydroxide, sodium hydroxide, lithium hydroxide, or aqueous ammonia, or water. Such as tetramethylammonium oxide, tetraethylammonium hydroxide, tetra (n-propyl) ammonium hydroxide, tetra (i-propyl) ammonium hydroxide, tetra (n-butyl) ammonium hydroxide and 2-hydroxyethyltrimethylammonium hydroxide Contains one or more of organic alkalis. Here, potassium hydroxide and the like are counted as one type. The alkali solution is suitable for processing both the barrier layer 5 and the wiring layer 7.
[0016]
Further, the fluorine-based solution includes hydrofluoric acid, ammonium fluoride, fluorosilicic acid, fluoroboric acid, sodium fluoride, potassium fluoride, potassium hydrogen fluoride, silver fluoride, tin fluoride, hexafluorosilicic acid, and hexafluorosilicic acid. Contains one or more of potassium fluorosilicate, ammonium hexafluorosilicate, or tetrafluoroborate. Here, hydrofluoric acid and the like are counted as one type. Copper is not attacked by hydrofluoric acid, a non-oxidizing acid, but tantalum is easily dissolved. Therefore, the fluorine-based solution is suitable for processing the barrier layer 5.
[0017]
The electrolytic processing liquid according to a fourth aspect is the electrolytic processing liquid according to any one of the first to third aspects, further including an oxidizing agent. The oxidizing agent forms an oxide film on the surface of tantalum constituting the barrier layer 5 and dissolves it in an alkaline solution. Further, the wiring layer 7 mainly composed of copper is oxidized to promote dissolution.
[0018]
The electrolytic working fluid according to claim 5 is the electrolytic working fluid according to claim 4, wherein the oxidizing agent is an organic material such as ozone water, hydrogen peroxide, peracetic acid, perbenzoic acid, and tert-butyl hydroperoxide. Permanganate compounds such as peroxides and potassium permanganate; dichromate compounds such as potassium dichromate; halogen acid compounds such as potassium iodate; nitric acid compounds such as nitric acid and iron nitrate; It contains one or more of a halogen acid compound, a transition metal salt such as potassium ferricyanide, a persulfate such as ammonium persulfate, or a heteropolyacid salt. Here, ozone water is counted as one type.
[0019]
The electrolytic processing liquid according to claim 6 is the electrolytic processing liquid according to any one of claims 1 to 5, and further includes abrasive grains. Since mechanical polishing with abrasive grains is added, and electrolytic composite polishing can be performed, the inhibitor adsorbed on the surface of the wiring layer 7 is efficiently removed, and as a result, dissolution of copper constituting the wiring layer 7 is promoted.
[0020]
The electrolytic machining liquid according to claim 7, wherein in the electrolytic machining liquid according to claim 6, the abrasive grains are silicon oxide, aluminum oxide, cerium oxide, manganese dioxide, cerium oxide, zirconia, diamond, silicon carbide, Alternatively, one or more of silicon nitride is included. Here, silicon oxide and the like are counted as one type.
[0021]
The electrolytic processing apparatus according to claim 8, wherein the electrolytic processing apparatus 8a performs electrolytic polishing of at least one layer of the barrier layer 5 formed on the substrate W or the wiring layer 7 containing copper as a main component. , A polishing tool 14 having a polishing surface for performing electropolishing on a surface to be processed of the substrate W, a processing electrode 13 acting as a cathode of the electropolishing, and the processing electrode 13. A power source 18 for applying a DC electric field or a pulse electric field between the substrate W and an electrolytic processing liquid containing one of an alkali solution or a fluorine-based solution and an inhibitor between the processing electrode 13 and the surface to be processed; 9 is provided with an electrolytic processing tank 10 that accommodates the tank 9. Here, the electrolytic processing liquid 9 may contain one or both of an oxidizing agent and abrasive grains. This can provide an electrolytic processing apparatus capable of suppressing the processing speed of the wiring layer 7 and obtaining a surface of the substrate W having excellent flatness.
Here, the electrolytic processing apparatus 8a for performing electrolytic polishing of at least one layer of the barrier layer 5 formed on the substrate W or the wiring layer 7 containing copper as a main component is typically formed by removing copper formed on the substrate. It refers to an electrolytic processing apparatus that performs electrolytic polishing of a wiring layer mainly containing, or a barrier layer formed on a substrate and a wiring layer mainly containing copper. In addition, the phrase “containing either one of the alkaline solution and the fluorine-based solution” means that only one of the alkali solution and the fluorine-based solution is contained and the other is not contained. In addition, an inhibitor typically refers to an inhibitor that adsorbs to the wiring layer and suppresses the dissolution of copper.
[0022]
The electrolytic processing apparatus according to claim 9, which is an electrolytic processing apparatus 8b that performs electrolytic polishing of at least one layer of the barrier layer 5 formed on the substrate W or the wiring layer 7 containing copper as a main component. And a polishing tool 14 having a polishing surface for performing electrolytic polishing on the surface to be processed of the substrate W, so that an electric field is applied to the surface to be processed during the electrolytic polishing. An electrode portion 23 on which a cathode 21 and an anode 22 are arranged; a power supply 18 for applying a DC electric field or a pulsed electric field between the cathode 21 and the anode 22; and a portion between the electrode portion 23 and the surface to be processed. An electrolytic processing tank 10 is provided for holding an electrolytic processing liquid 9 containing either an alkaline solution or a fluorine-based solution and an inhibitor. Here, the electrolytic processing liquid 9 may contain one or both of an oxidizing agent and abrasive grains. As a result, effective processing can be performed even when the wiring layer is removed and becomes an island shape.
Here, the electrolytic processing apparatus 8b that performs electrolytic polishing of at least one layer of the barrier layer 5 formed on the substrate W or the wiring layer 7 containing copper as a main component is typically formed by removing copper formed on the substrate. It refers to an electrolytic processing apparatus that performs electrolytic polishing of a wiring layer mainly containing, or a barrier layer formed on a substrate and a wiring layer mainly containing copper. In addition, the phrase “containing either one of the alkaline solution and the fluorine-based solution” means that only one of the alkali solution and the fluorine-based solution is contained and the other is not contained. In addition, an inhibitor typically refers to an inhibitor that adsorbs to the wiring layer and suppresses the dissolution of copper.
[0023]
11. The wiring processing method according to claim 10, wherein an insulating layer 2 is formed on a substrate W having a conductive layer 1a on the surface, and a contact hole 3 and a wiring groove 4 reaching the conductive layer 1a are formed in the insulating layer 2. Forming, forming a barrier layer 5 on the insulating layer 2 in which the contact holes 3 and the wiring grooves 4 are formed, and forming a wiring layer made of a metal containing copper as a main component on the barrier layer 5. Depositing the contact hole 3 and the wiring groove 4 so as to fill the contact hole 3 and the wiring groove 4, and removing the portion of the wiring layer 7 deposited on the insulating film 2 by using one of an alkaline solution or a fluorine-based solution. Removing the portion of the barrier layer 5 deposited on the insulating film 2 with one of an alkaline solution or a fluorine-based solution by using an electrolytic processing solution 9 containing an inhibitor. And a step of removing the electrolytic polishing using an electroless working solution 9. Here, a semiconductor substrate or the like as a base material on which devices, wirings, and the like are mounted is referred to as an original substrate 1, and a substrate W in the course of a manufacturing process is referred to as a substrate W. The conductive layer 1a may be an impurity diffusion layer formed on the original substrate 1, but a wiring layer may be formed on the surface of the substrate W in a multilayer wiring structure or the like. And Further, the electrolytic processing liquid 9 may contain one or both of an oxidizing agent and abrasive grains. According to the present invention, it is possible to provide a wiring processing method capable of suppressing the processing speed of the wiring layer 7 and obtaining a surface of the substrate W having excellent flatness.
Here, including either one of the alkaline solution and the fluorine-based solution means that only one of the alkali solution and the fluorine-based solution is included and the other is not included. In addition, an inhibitor typically refers to an inhibitor that adsorbs to the wiring layer and suppresses the dissolution of copper.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
[Embodiment of wiring processing method]
FIG. 1 shows an example of forming and processing steps of a wiring mainly composed of copper in a semiconductor integrated circuit in order to explain a wiring processing method according to the present invention. FIG. 5 used for describing the wiring processing method of the conventional example can be used as it is and will be described with reference to FIG.
[0025]
A conductive layer 1a is formed on a semiconductor substrate 1 (original substrate) of a semiconductor integrated circuit (step S01). FIG. 5 shows the case where the conductive layer 1a is an impurity diffusion layer formed in the substrate, but may be a wiring layer formed on the surface of the substrate W, for example, in the case of a multilayer wiring structure. Next, on the semiconductor substrate 1 having the conductive layer 1a, ₂ An insulating layer 2 made of a film, a low-k material, or the like is deposited by, for example, a low-pressure CVD (Chemical Vapor Deposition) method (Step S02). Next, a contact hole 3 and a wiring groove 4 are formed in the insulating layer 2 by, for example, a known lithography etching technique (Step S03), and a barrier layer 5 (for preventing copper diffusion into the insulating layer 2) is formed thereon. In step S04, a seed layer 6 is formed thereon as a power supply layer for electrolytic plating (step S05). The barrier layer 5 is made of, for example, a Ta / TaN mixed film deposited by a sputtering method, a film of TiN, WN, SiTiN, CoWP, CoWB or the like, and the seed layer 6 is made of, for example, a Cu film deposited by a sputtering method. This state is shown in FIG.
[0026]
FIG. 5B shows a state where a copper film as the wiring layer 7 is deposited. The copper film 7 is formed by an electrolytic plating method (Step S06). As a result, copper is filled in the contact hole 3 and the wiring groove 4 and the insulating layer 2 is covered with the copper film 7. In this state, the surface of the copper film 7 has irregularities. Note that the copper film 7 may be a film mainly composed of copper. Also, since the same copper as the wiring layer 7 is used for the seed layer 6, it is integrated with the wiring layer 7 and functions as a wiring after the device is completed. Removal by electrolysis or polishing is also performed integrally with the wiring layer 7. Therefore, the wiring layer in the claims includes a seed layer.
[0027]
The above process is performed in the same manner as the conventional process, but the removal of the copper film 7 and the barrier layer 5 as unnecessary wiring layers on the insulating layer 2 is according to the present invention. As the electrolytic processing liquid, a liquid containing one of an alkaline solution or a fluorine-based solution and an inhibitor is used.
[0028]
In the ordinary electrolytic polishing method, when the substrate W on which the wiring layer 7 is formed is connected to the anode side, the polishing tool is connected to the cathode side, and the electrolytic processing liquid is filled during the connection, the wiring layer 7 is formed by the electrolytic action of the electrolytic processing liquid. Is ionized and dissolved in the electrolytic processing solution. The efficiency of the electrolytic processing depends not only on the electrolytic processing liquid but also on the pulse voltage and the pulse period, the distance between the wiring layer 7 serving as the anode and the cathode plate serving as the cathode, the ratio of the wiring layer exposed on the surface of the substrate W, and the like. Since the wiring layer 7 acts as an anode during electrolytic processing, when the copper film 7 covers the surface of the substrate W, a large amount of current flows due to electrolysis and the electrolytic processing is promoted, but the dissolution of the copper film 7 proceeds. Then, when the copper film exposed on the surface decreases, the current flowing by electrolysis decreases, and the removal is suppressed. However, since the electric field concentrates on the remaining copper film and elution occurs, there is an effect that unnecessary copper film hardly remains. On the other hand, when the required copper film is exposed on the surface, there is a disadvantage that it is easily removed excessively.
[0029]
FIG. 5C shows a state in which excess copper is removed by electrolytic polishing and the surface is flattened. Copper is removed by an electrolytic polishing method (Step S07). In the present invention, an electrolytic processing solution containing either an alkaline solution or a fluorine-based solution and an inhibitor is used. Inhibitors contain oxygen, nitrogen, and sulfur atoms and adsorb lone pairs of these elements to the copper surface at the point of adsorption, thereby preventing and delaying the dissolution of copper as ions.
[0030]
In the present embodiment, a liquid containing an alkaline solution and an inhibitor (corrosion inhibitor) is used as the electrolytic processing liquid. The alkali has solubility in both copper Cu and the barrier layer, for example, tantalum Ta, and can dissolve both metals. Since the barrier layer 5 below the wiring layer 7 to be removed deposited on the insulating layer 2 is also a layer to be removed, there is no problem even if the processing proceeds to the lower barrier layer 5 when the wiring layer 7 is processed.
[0031]
The inhibitor is adsorbed on the copper surface (step S08), thereby suppressing the dissolution of copper as ions.
By the way, in the present embodiment, the polishing of the surface of the substrate W is also performed by lightly pressing the polishing tool on the surface of the substrate W and rotating the substrate W with respect to the substrate W, etc. Done. By this polishing, the inhibitor adsorbed preferentially on the surface is removed from the highest convex portion of the wiring layer 7 (step S09). Dissolution of copper proceeds selectively in the portion where copper is exposed after being removed (step S10). As the time elapses, the inhibitor again adsorbs to the exposed copper surface, and the dissolution of copper is suppressed (return to step S08 again). In the subsequent surface polishing, the inhibitor adsorbed on the surface at the next higher convex portion is removed, and the dissolution of copper proceeds selectively in the portion where copper is newly exposed. As described above, since the elution of the metal film 7 proceeds sequentially from a higher position on the surface of the substrate W, flattening is promoted as a result. Further, since the inhibitor on the copper surface located at a low place is not removed, dishing and erosion can be prevented. The copper film 7 and the seed layer 6 are removed by the electrolytic polishing described above, whereby the barrier layer 5 is exposed over the entire surface (step S11).
[0032]
FIG. 5D shows a state where the barrier layer 5 exposed on the surface is removed by electrolytic polishing and the surface is flattened. The removal of the barrier layer 5 is performed by an electrolytic polishing method (Step S12). In this embodiment, a liquid containing a fluorine-based solution and an inhibitor (corrosion inhibitor) is used as the electrolytic processing liquid. Copper Cu is not attacked by hydrofluoric acid, but tantalum Ta is easily dissolved. Therefore, when the unnecessary barrier layer 5 on the insulating layer 2 is removed, the wiring layer 7 exposed on the contact hole 3 and the wiring groove 4 is not processed, so that dishing and erosion can be prevented, which is preferable.
[0033]
Further, the inhibitor is adsorbed to the wiring layer 7 exposed on the contact hole 3 and the wiring groove 4 (step S13), so that the removal of the wiring layer is also suppressed. The barrier layer 5 is dissolved and removed (step S14), thereby exposing the insulating layer 2 over the entire surface (step S15). Polishing is performed so that the surface of the copper film 7 on the contact hole 3 and the wiring groove 4 and the surface of the insulating layer 2 are substantially flush with each other, and the wiring processing is completed (Step S16). In addition, since the barrier layer 5 is thin and has only a small surface irregularity, it is not necessary to adsorb the inhibitor on the surface of the barrier layer 5 to promote flattening.
[0034]
Returning to step S02, by repeating the steps of forming and processing the wiring, multilayer wiring becomes possible. In this case, the conductive layer 1a becomes a wiring layer formed on the surface of the substrate W. The wiring processing method according to the present invention can also be used in this multilayer wiring process.
[0035]
Further, the electrolytic processing liquid according to the present invention may contain an oxidizing agent. Although tantalum Ta used for the barrier layer 5 is insoluble in acids other than hydrofluoric acid and is a stable metal, its oxide film is dissolved in an alkaline solution. (Processing speed) of the barrier layer 5 can be accelerated. Further, since the oxidizing agent promotes the dissolution of copper, the removal of the wiring layer 7 by electrolytic polishing can also be promoted.
[0036]
Further, the electrolytic processing solution according to the present invention may contain abrasive grains. Since mechanical polishing with abrasive grains is added and electric field composite polishing can be performed, polishing and the resulting dissolution of copper can be promoted. Therefore, by including an appropriate amount of abrasive grains, the efficiency of electrolytic processing can be improved. Further, since polishing is performed preferentially from the convex portion, flattening is promoted by the cooperative action with the inhibitor.
[0037]
[Embodiment of electrolytic machining liquid]
The electrolytic processing liquid according to the present invention is an electrolytic processing liquid for flattening the surface of the substrate W by electrolytic polishing of at least one layer of the barrier layer 5 or the wiring layer 7 mainly composed of copper formed on the substrate W, It contains either an alkaline solution or a fluorine-based solution, and an inhibitor that suppresses the dissolution of copper. Further, one or both of an oxidizing agent and abrasive grains may be included. Here, the composition and concentration of the electrolytic processing solution and the effect of the inhibitor will be described.
Here, the electrolytic processing liquid 9 for flattening the surface of the substrate W by electrolytically polishing at least one layer of the barrier layer 5 or the wiring layer 7 containing copper as a main component formed on the substrate W is typically Is an electrolytic processing liquid for flattening the substrate surface by electrolytically polishing a wiring layer mainly composed of copper formed on the substrate, or a barrier layer formed on the substrate and a wiring layer mainly composed of copper. Say. In addition, the phrase “containing either one of the alkaline solution and the fluorine-based solution” means that only one of the alkali solution and the fluorine-based solution is contained and the other is not contained. In addition, an inhibitor typically refers to an inhibitor that adsorbs to the wiring layer and suppresses the dissolution of copper.
[0038]
Inhibitors used in the electrolytic processing solution of the present invention include, for example, benzotriazole or derivatives thereof (5-methylbenzotriazole, carboxylbenzotriazole, etc.), benzimidazole or derivatives thereof, phenacetin, quinaldic acid, polyvinylpyrrolidone, acetonitrile, acrylonitrile, phenylacetonitrile And amines (methylamine, ethylamine, dimethylamine, diethylamine, ethylenediaminetetraacetic acid) and the like. Two or more types of inhibitors may be included. The concentration of the inhibitor is 0.001 to 1% by mass, preferably 0.05 to 0.2% by mass. These inhibitors contain oxygen, nitrogen, and sulfur atoms and can adsorb lone pairs of these elements to the copper surface at the point of adsorption to prevent or delay copper from dissolving as ions. Therefore, the dissolution of copper is selectively promoted in the portion where the inhibitor adsorbed on the copper surface has been removed by polishing, so that the wiring layer 7 is preferentially removed from the protruding portion and becomes flat during the electrolytic polishing process. Will be promoted.
[0039]
The alkaline solution includes, for example, inorganic alkalis such as potassium hydroxide, sodium hydroxide, lithium hydroxide, and ammonia water, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra (n-propyl) ammonium hydroxide, and tetra (i) hydroxide. -Propyl) ammonium, tetra (n-butyl) ammonium hydroxide, and 2-hydroxyethyltrimethylammonium hydroxide. It may contain two or more kinds of alkalis. The concentration of the alkali is 0.1 to 55% by mass, preferably 10 to 55% by mass. The alkali solution has solubility in copper Cu and also in the barrier layer 5 such as tantalum Ta. Therefore, the alkaline solution can be used for processing both the barrier layer 5 and the wiring layer 7. Since the barrier layer below the wiring layer to be removed deposited on the insulating layer 2 is also a layer to be removed, there is no problem if the processing proceeds to the lower barrier layer 5 when the wiring layer 7 is processed.
[0040]
Examples of the fluorine-based solution include hydrofluoric acid, ammonium fluoride, fluorosilicic acid, fluoroboric acid, sodium fluoride, potassium fluoride, potassium hydrogen fluoride, silver fluoride, tin fluoride, hexafluorosilicic acid, and hexafluorosilicic acid. Potassium, ammonium hexafluorosilicate, tetrafluoroboric acid, or the like. Two or more of these may be included. The concentration of the fluorine-based solution is 0.01 to 40% by mass, preferably 0.1 to 10% by mass. Copper Cu is not attacked by hydrofluoric acid which is a non-oxidizing acid, but tantalum Ta is easily dissolved. Therefore, the fluorine-based solution can be used for processing the barrier layer 5. When the unnecessary barrier layer on the insulating layer 2 is processed, the wiring layer 7 exposed on the contact hole 3 and the wiring groove 4 is not processed, so that dishing and erosion can be prevented, which is preferable.
[0041]
Examples of the oxidizing agent include organic peroxides such as ozone water, hydrogen peroxide, peracetic acid, perbenzoic acid, and tert-butyl hydroperoxide; permanganate compounds such as potassium permanganate; Chromic acid compounds, halogen acid compounds such as potassium iodate, nitric acid compounds such as nitric acid and iron nitrate, perhalic acid compounds such as perchloric acid, transition metal salts such as potassium ferricyanide, and persulfates such as ammonium persulfate. . Two or more of these may be included. The concentration of the oxidizing agent is 0.01 to 30% by mass, preferably 0.1 to 10% by mass. Tantalum is insoluble in acids other than hydrofluoric acid, but tantalum oxide dissolves in hydrofluoric acid and alkali, so it forms an oxide film on the surface of tantalum and then dissolves in an alkaline solution. Therefore, the removal of the barrier layer 5 can be promoted by including these oxidizing agents in the electrolytic processing solution. Further, since the oxidizing agent promotes the dissolution of copper, the removal of the wiring layer 7 can be promoted.
[0042]
The abrasive grains are, for example, silicon oxide (silica), aluminum oxide, cerium oxide, manganese dioxide, cerium oxide, zirconia, diamond, silicon carbide, silicon nitride, and the like. Two or more of these may be included. When polishing the barrier layer, it is preferable to use colloidal silica. The concentration of these abrasive grains is 0.1 to 30% by mass, preferably 1 to 10% by mass. Since mechanical polishing with abrasive grains is added and electrolytic composite polishing can be performed, inhibitors adsorbed on the copper surface can be effectively removed, and as a result, dissolution of copper can be promoted. Therefore, the efficiency of electrolytic processing can be improved by including an appropriate amount of abrasive grains. Further, since polishing is performed preferentially from the convex portion, flattening is promoted by the cooperative action with the inhibitor.
[0043]
[Example of electrolytic processing liquid]
0.1% by weight of nitric acid and 1% by weight of hydrofluoric acid in pure water as an electrolytic processing solution, and 0.1% each of 5-methylbenzotriazole, carboxylbenzotriazole, phenacetin, quinaldic acid or polyvinyl alcohol as an inhibitor. The substrate W on which the wiring layer 7 made of copper and the barrier layer 5 made of a Ta / TaN mixed film were formed was electrolytically processed using the four kinds of liquids in which the mass% was dissolved. Tantalum was dissolved by the electrolytic action of the mixed solution of nitric acid and hydrofluoric acid, and the processing speed of copper became almost the same as the processing speed of tantalum due to the effect of these inhibitors, and a flat substrate W was obtained.
[0044]
[First Embodiment of Electrolytic Processing Apparatus]
An electrolytic processing apparatus used for electrolytic polishing using the aforementioned electrolytic processing liquid will be described. FIG. 2 shows an electrolytic processing apparatus 8a according to the first embodiment of the present invention. The electrolytic processing apparatus 8a is open at the top and has a bottomed cylindrical electrolytic processing tank 10 containing an electrolytic processing liquid 9 therein, and is disposed above the electrolytic processing tank 10 so that the substrate W can be detachably attached downward. And a substrate holding unit 11 (corresponding to a substrate holding unit) for holding.
[0045]
The electrolytic processing tank 10 is directly connected to a main shaft 12 that rotates with the driving of a motor or the like, and has a circular flat plate-shaped cathode plate 13 (corresponding to a processing electrode) immersed in the electrolytic processing liquid 9 and serving as a cathode at the bottom. ) Are arranged horizontally. The cathode plate 13 is formed of, for example, gold, platinum, ruthenium, rhodium, osmium, or the like as an electrode material having resistance to hydrofluoric acid, alkali, and oxidizing agent. The upper surface of the cathode plate 13 is provided with a lattice-shaped long groove 13a extending linearly over the entire length in the vertical and horizontal directions. The electrolytic machining liquid 9 flows through the long groove 13a, and products and bubbles generated by electrolytic polishing are discharged. A region of the cathode plate 13 surrounded by the long groove 13a is close to the substrate W and functions as an electrode. Further, a polishing pad 14 (corresponding to a polishing tool) is disposed on the upper surface of the cathode plate 13. As the polishing pad 14, for example, a foamed polyurethane or the like, which is provided with a number of small holes in portions corresponding to the electrodes and has liquid permeability, is used. When the small holes are filled with the electrolytic processing liquid 9, current is applied between the electrodes and the substrate W. Alternatively, instead of providing the small holes, a member in which the polishing pad 14 itself has liquid permeability may be used.
[0046]
As the main shaft 12 rotates, the electrolytic processing bath 10 rotates integrally with the polishing pad 14. In this example, an example is shown in which the electrolytic processing tank 10 rotates, but a scroll movement (translational rotation movement) or a reciprocating movement may be performed. Further, the shape of the long groove 13a prevents a difference in current density between the central part and the outer peripheral part of the cathode plate 13 and also allows the electrolytic processing liquid 9 and hydrogen gas to flow smoothly along the long groove 13a. Therefore, when the electrolytic processing tank 10 performs a scroll movement, it is preferable that the electrolytic processing tank 10 has a lattice shape, and when the electrolytic processing tank 10 performs a reciprocating movement, the electrolytic processing tank 10 is arranged in parallel along the moving direction. Is preferred.
[0047]
The substrate holding unit 11 is connected to a lower side of a support rod 15 having a rotation mechanism capable of controlling a rotation speed and a vertical movement mechanism capable of adjusting a polishing pressure, and holds the substrate W on its lower surface by, for example, vacuum suction. It is supposed to. It is also possible to perform polishing while the surface of the substrate W is pressed against the polishing pad 14. When the substrate W is sucked and held on the substrate holding portion 11, the outer peripheral portion of the lower surface of the substrate holding portion 11 comes into contact with the copper film 7 at a peripheral portion of the substrate W, a portion outside the device region near the bevel portion, and An electrical contact 16 having the copper film 7 deposited on the surface of W as an anode is provided. The electrical contact 16 is connected to an anode terminal of a rectifier 18 (corresponding to a power supply) as a DC power supply or a pulse power supply arranged outside by a roll sliding connector and a wiring 17a built in the support rod 15, and is connected to a cathode plate. 13 is connected to the cathode terminal of the rectifier 18 via the wiring 17b.
[0048]
Further, an electrolytic machining liquid supply unit 19 for supplying the electrolytic machining liquid 9 is disposed above the electrolytic machining tank 10, and furthermore, a control unit 20 for adjusting and managing each device and overall operation and a safety device. (Not shown) and the like. The electrolytic processing tank 10, the electrolytic processing liquid supply unit 19, and the piping and waste liquid pipe between them are made of Teflon (registered trademark of DuPont) or the like which is acid-resistant, alkali-resistant and chemically stable so as not to react with the electrolytic processing liquid 9. Have been made. The electrolytic processing liquid 9 may include one or both of an oxidizing agent and abrasive grains. In addition, the control unit 20 appropriately adjusts and controls pulse application conditions during electrolytic polishing, rotation and pressing of the substrate W and the polishing tool 14, supply of the electrolytic processing liquid 9 to the electrolytic processing tank 10, and the like.
[0049]
As shown in FIG. 5B, the electrolytic processing apparatus 8a electrolytically polishes the barrier layer 5 and the wiring layer 7 of the substrate W on which the barrier layer 5 and the wiring layer 7 are deposited, and cleans the surface of the substrate W. It is suitable for flattening, and its polishing operation will be described.
[0050]
The electrolytic processing liquid 9 is supplied into the electrolytic processing tank 10, and the electrolytic processing liquid 9 and the polishing pad 14 are integrally rotated at a rotation speed of, for example, about 90 rpm. On the other hand, the substrate W is suction-held by the substrate holding unit 11 downward. In this state, the substrate W is lowered while rotating at a rotation speed of, for example, about 90 rpm in a direction opposite to the electrolytic processing bath 10, and the surface (lower surface) of the substrate W is, for example, 300 g / cm. ² The surface of the polishing pad 14 is brought into contact with the surface of the polishing pad 14 at a constant pressure, and at the same time, a current density of 0.5 to 5 A / dm is applied between the cathode plate 13 and the electrical contact 16 by the rectifier 18. ² , Preferably 1-3 A / dm ² Or a current density of 0.5 to 5 A / dm ² , Preferably 1-3 A / dm ² Then, a pulse current having a DUTY ratio of 10 to 99%, preferably 30 to 90% is passed.
[0051]
At this time, the electrolytic processing liquid 9 is supplied between the substrate W and the polishing pad 14 from the long groove 13a provided on the surface of the cathode plate 13, and the electrolytic processing liquid 9 after processing is caused by particles floating in the electrolytic processing liquid 9 and reaction. It passes through the long groove 13a together with the generated bubbles and the like and smoothly flows out to the waste liquid pipe.
[0052]
Under this condition, the copper film 7 is polished at a high speed while being effectively planarized. That is, when an electrolytic processing solution 9 containing an inhibitor and an alkali solution that suppress the dissolution of copper is used, and electrolytic polishing is performed using copper as an anode, the inhibitor is adsorbed on the exposed surface of the copper film 7 and the electrolytic elution of copper is performed. Suppress. The adsorbed inhibitor can be easily removed by the rotating low pressure polishing pad 14. Even when the electrolytic processing liquid 9 does not contain abrasive grains, it can be easily removed. Therefore, when the polishing is performed with the polishing pad 14, the inhibitor adsorbed on the surface of the copper film 7 is removed, and the copper film 7 is exposed at the removed portion and is dissolved by the electrolytic action. If the copper film 7 has irregularities, the convexities are polished preferentially, so that the flattening is promoted in the process of electrolytic polishing. In addition, the conduction to the portion covered with the inhibitor is suppressed, and the current tends to concentrate on the portion where the metal surface is exposed (that is, the convex portion of the trunk membrane 7). In addition, the dissolution is suppressed while being covered with the inhibitor, so that only the protrusions are selectively removed by grinding, and the flattening is promoted.
[0053]
After the completion of the electropolishing, the substrate W held by the substrate holding unit 11 is lifted, the rotation of the substrate W is stopped, and the substrate W after the completion of the electropolishing is carried out of the electrolytic processing apparatus 8a.
[0054]
3A to 3C show examples of the shape (plan view) of the electrodes of the cathode plate (all of them are only partially shown, and the electrodes are uniformly arranged on the entire surface). In the case of the cathode plate 13 of FIG. 2, as shown in FIG. 3A, the region surrounded by the long groove 13a is closer to the substrate W and functions as a cathode. Modifications are shown in FIGS. 3B and 3C. In FIG. 3B, an electrode (cathode) is buried in the formed long groove. In this case, it is better to form a step between the upper surface of the cathode plate and the upper surface of the electrode embedded in the groove to secure the flow path of the electrolytic processing liquid. In FIG. 3C, the electrodes to be embedded in the grooves are not bar-shaped, but are subdivided like a mosaic, and a plurality of electrodes are scattered. 3B and 3C, if each electrode can be connected to the cathode terminal of the rectifier 18, a part of the cathode plate 13 may be formed of an insulator.
[0055]
[Second embodiment of electrolytic processing apparatus]
FIG. 4 shows a second embodiment of the electrolytic processing apparatus according to the present invention. 4, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. The difference between the electrolytic processing apparatus 8b and the electrolytic processing apparatus 8a is that an electrode plate 23 (electrode section) made of an insulating material in which a large number of cathode rods 21 and anode rods 22 are alternately arranged inside a bottom of the electrolytic processing tank 10 is provided. ) Are arranged horizontally. On the upper surface of the electrode plate 23, there is formed a lattice-shaped long groove 23a extending linearly over the entire length in the vertical and horizontal directions. The electrolytic processing liquid 9 and bubbles are discharged by the long grooves 23a. Above the cathode rod 21, there is a porous filler 24 so that the electrolytic processing liquid 9 and bubbles flow. The filler 24 is a porous material for impregnating the electrolytic processing liquid 9 and is preferably a chemical-resistant material.
[0056]
As the electrolysis conditions, the current density was 0.5-5 A / dm. ² Preferably 1-3 A / dm ² Or a current density of 0.5-5 A / dm ² , Preferably 1-3 A / dm ² Then, a pulse current with a DUTY ratio of 10-99%, preferably 30-90% is passed.
[0057]
All the cathode rods 21 are connected to cathode terminals of a rectifier 18 (corresponding to a power supply) as a DC power supply or a pulsed power supply arranged outside via a wiring 17a. It is connected to the anode terminal of the rectifier 18 via the wiring 17b. In addition, the electric contact 16 as in the electrolytic processing apparatus 8a is not provided in the present apparatus 8b.
[0058]
In particular, the electrolytic processing apparatus 8b performs the dissolution of the excess copper film 7 deposited on the surface of the substrate W, and the substrate W in a state where the barrier layer 5 is exposed on the surface and the copper film 7 has an island shape. This is suitable for electrolytic polishing of the barrier layer 5 and the copper film 7 on the surface. That is, when the copper film 7 has an island shape, it is not possible to uniformly supply current to the copper film 7 from an external terminal such as an electric contact. Even in such a case, according to the electrolytic processing apparatus 8b, the electrolytic polishing of the copper film 7 can be advanced by making the copper surface locally positive by utilizing the bipolar phenomenon.
[0059]
Although the embodiments of the present invention have been described above, it is apparent that the embodiments can be variously modified without departing from the spirit of the present invention. For example, in the embodiment, the case where the wiring is made of copper has been described.However, if the electrolytic processing solution of the present invention is used, even with a metal mainly containing copper, the inhibitor is adsorbed on the metal surface to suppress electrolysis, and Since the inhibitor can be removed by lightly polishing the surface, the same effect as that of copper can be obtained. Further, in the embodiment, the case where the barrier layer is a film containing Ta has been described, but the electrolytic processing solution of the present invention can be applied to a film containing another metal such as TiN.
Further, the electrolytic processing solution of the present invention can be used for electrolytic polishing of only the wiring layer and only the barrier layer. Further, it can be used for a technique other than the damascene method for flattening a substrate surface having a wiring layer and an insulating layer. Further, when the inhibitor does not stop dissolution of copper but delays the dissolution, it may be used only for electrolytic processing without polishing.
[0060]
Further, in the embodiment, the example of the electrolytic processing apparatus in which the substrate is disposed on the upper side and the cathode plate is disposed on the lower side has been described. However, the configuration may be such that the substrate is disposed on the lower side and the cathode plate is disposed on the upper side. Further, the shape of the cathode plate is not limited to a circle but may be a square. Also, the long grooves of the cathode plate are not lattice-shaped, but can be formed, for example, in a shape combining concentric circles and radiation. Further, the DC electric field and the pulse electric field may be superposed, and the voltage and period of the pulse can be changed. Further, in the embodiment, when the electrolytic processing liquid contains the polishing abrasive grains, the example in which the electrolytic processing liquid including the polishing abrasive grains is supplied from the electrolytic processing liquid supply unit has been described. The liquid and the polishing liquid (abrasive slurry or the like) may be supplied from separate supply units.
[0061]
Further, in the embodiment, the wiring processing method in the case where the semiconductor substrate (original substrate) has a conductive layer is described. However, the conductive layer may be a wiring layer formed on the surface of the substrate W. The original substrate is not limited to a semiconductor substrate, but may be an insulator such as sapphire. In this case, the first conductive layer is formed in the epitaxial layer or the like.
[0062]
【The invention's effect】
As described above, according to the electrolytic processing solution of the present invention, the inhibitor suppresses the dissolution of copper, so that the barrier layer and the copper wiring layer can be removed at the same processing speed. In addition, since the dissolution of copper is selectively promoted in the portion where the inhibitor adsorbed on the surface has been removed by polishing, the wiring layer is preferentially removed from the convex portion, and the flatness is improved without causing dishing or erosion. An excellent substrate surface can be obtained.
[0063]
Further, according to the electrolytic processing apparatus of the present invention, electrolytic polishing using the electrolytic processing liquid can be performed. Further, according to the wiring processing method of the present invention, in a wiring forming process of a semiconductor integrated circuit or the like, a wiring structure having excellent flatness can be obtained by using this electrolytic processing solution.
[0064]
In addition, since the electrolytic processing solution of the present invention employs electrolytic polishing, it can be polished with a low load, and is suitable for a wiring structure using a soft metal such as copper or a low-k material as an interlayer insulating material. Also, the consumption of the slurry can be reduced.
[0065]
When an oxidizing agent is contained in the electrolytic processing solution, the dissolution of the barrier layer and the wiring layer is promoted, and the efficiency of the electrolytic processing is increased. Further, when the polishing fluid is contained in the electrolytic processing liquid, the electrolytic compound polishing can be performed in addition to the mechanical polishing by the polishing polishing particles, so that more efficient flattening can be realized.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a process of forming and processing a copper wiring according to the present invention.
FIG. 2 is a diagram illustrating a configuration of an electrolytic processing apparatus according to the first embodiment of the present invention.
FIG. 3 is a diagram illustrating an example of an electrode shape of a cathode plate according to the first embodiment of the present invention.
FIG. 4 is a diagram illustrating a configuration of an electrolytic processing apparatus according to a second embodiment of the present invention.
FIG. 5 is a diagram showing an example of a conventional copper wiring formation and processing process.
[Explanation of symbols]
1 semiconductor substrate
1a conductive layer
2 Insulating layer
3 Contact holes
4 Wiring groove
5 Barrier layer
6 Seed layer
7 Wiring layer
8a, 8b electrolytic processing equipment
9 Electrolytic machining fluid
10 Electrolytic processing tank
11 Substrate holder
12 spindle
13 Cathode plate
13a long groove
14 Polishing pad
15 Support rod
16 electrical contacts
17a, 17b wiring
18 Rectifier
19 Electrolytic machining fluid supply unit
20 control unit
21 Cathode rod
22 Anode rod
23 Electrode plate
23a long groove
24 filler
W substrate

Claims (10)

An electrolytic processing liquid for electrolytically polishing at least one of a barrier layer or a wiring layer containing copper as a main component formed on the substrate to planarize the substrate surface;
Containing either an alkaline solution or a fluorine-based solution and an inhibitor;
Electrolytic machining fluid. The inhibitor may be benzotriazole or a derivative thereof (e.g., 5-methylbenzotriazole, carboxylbenzotriazole), benzimidazole or a derivative thereof, phenacetin, quinaldic acid, polyvinyl alcohol, polyvinylpyrrolidone, acetonitrile, acrylonitrile, phenylacetonitrile, or an amine ( The electrolytic processing solution according to claim 1, which comprises at least one of methylamine, ethylamine, dimethylamine, diethylamine, and ethylenediaminetetraacetic acid. The alkali solution may be an inorganic alkali such as potassium hydroxide, sodium hydroxide, lithium hydroxide, or aqueous ammonia, or tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra (n-propyl) ammonium hydroxide, tetrahydroxide ( at least one of organic alkalis such as i-propyl) ammonium, tetra (n-butyl) ammonium hydroxide and 2-hydroxyethyltrimethylammonium hydroxide, wherein the fluorine-based solution is hydrofluoric acid, fluorinated Of ammonium, fluorosilicic acid, fluoroboric acid, sodium fluoride, potassium fluoride, potassium hydrogen difluoride, silver fluoride, tin fluoride, hexafluorosilicic acid, potassium hexafluorosilicate, ammonium hexafluorosilicate, or tetrafluoroboric acid 3. The method according to claim 1, further comprising at least one of the following. Electrolytic processing solution according. The electrolytic processing liquid according to any one of claims 1 to 3, further comprising an oxidizing agent. The oxidizing agent includes organic peroxides such as ozone water, hydrogen peroxide, peracetic acid, perbenzoic acid, and tert-butyl hydroperoxide; permanganate compounds such as potassium permanganate; and dehydration compounds such as potassium dichromate. Chromic acid compounds, halogen acid compounds such as potassium iodate, nitric acid compounds such as nitric acid and iron nitrate, perhalic acid compounds such as perchloric acid, transition metal salts such as potassium ferricyanide, persulfates such as ammonium persulfate, or heteropoly compounds The electrolytic machining liquid according to claim 4, comprising one or more of acid salts. The electrolytic processing liquid according to claim 1, further comprising abrasive grains. The electrolytic processing liquid according to claim 6, wherein the abrasive grains include at least one of silicon oxide, aluminum oxide, cerium oxide, manganese dioxide, cerium oxide, zirconia, diamond, silicon carbide, and silicon nitride. An electrolytic processing apparatus for performing electrolytic polishing of at least one of a barrier layer formed on a substrate and a wiring layer containing copper as a main component;
Substrate holding means for holding the substrate;
A polishing tool having a polishing surface for performing electrolytic polishing on a surface to be processed of the substrate;
A working electrode that acts as a cathode for the electropolishing;
A power source for applying a DC electric field or a pulse electric field between the processing electrode and the substrate; and electrolytic processing including one of an alkali solution or a fluorine-based solution and an inhibitor between the processing electrode and the surface to be processed. Equipped with an electrolytic processing tank for holding the liquid;
Electrochemical processing equipment. An electrolytic processing apparatus for performing electrolytic polishing of at least one of a barrier layer formed on a substrate and a wiring layer containing copper as a main component;
Substrate holding means for holding the substrate;
A polishing tool having a polishing surface for performing electrolytic polishing on a surface to be processed of the substrate;
An electrode section in which a cathode and an anode are arranged so that an electric field is applied to the surface to be processed during electrolytic polishing;
A power supply for applying a DC electric field or a pulse electric field between the cathode and the anode;
An electrolytic processing tank is provided between the electrode part and the surface to be processed, so as to hold an electrolytic processing solution containing one of an alkaline solution or a fluorine-based solution and an inhibitor;
Electrochemical processing equipment. Forming an insulating layer on a substrate having a conductive layer on the surface; forming a contact hole and a wiring groove reaching the conductive layer in the insulating layer;
Depositing a barrier layer on the insulating layer in which the contact hole and the wiring groove are formed;
Depositing a wiring layer made of a metal containing copper as a main component on the barrier layer so as to fill the contact hole and the wiring groove;
Removing a portion of the wiring layer deposited on the insulating film by electrolytic polishing using an electrolytic processing solution containing one of an alkali solution or a fluorine-based solution and an inhibitor;
Removing a portion of the barrier layer deposited on the insulating film by electrolytic polishing using an electrolytic processing solution containing one of an alkali solution or a fluorine-based solution and an inhibitor;
Wiring processing method.

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