JP2014044982A - Polishing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing composition which is suitable for polishing of a material containing noble metal and enables improvement in throughput.SOLUTION: A polishing composition is used for polishing of an object to be polished having a layer containing noble metal, and contains a hypohalous acid ion, a complexing agent and water. Its pH is 5.5 or more.

Description

  The present invention relates to a polishing composition, and particularly to a polishing composition suitable for polishing precious metals.

  In recent years, new microfabrication techniques have been developed along with higher integration and higher performance of LSIs. Chemical mechanical polishing (hereinafter also simply referred to as CMP) is one of them, and is frequently used in LSI manufacturing processes, particularly in the formation of interlayer insulating films, metal plugs, and embedded wiring (damascene wiring) in the multilayer wiring forming process. The technology used. This technique is disclosed in Patent Document 1, for example. Damascene wiring technology can simplify the wiring process and improve yield and reliability, and its application is expected to expand in the future.

  In high-speed logic devices, copper is mainly used as a wiring metal because of its low resistance as damascene wiring. Copper is expected to be used in memory devices such as DRAMs in the future. . A general method of metal CMP is to apply a polishing pad on a circular polishing platen (platen), immerse the surface of the polishing pad with an abrasive and press the surface on which the metal film of the substrate is formed. In this state, the polishing platen is rotated in a state in which the pressure (hereinafter also simply referred to as polishing pressure) is applied, and the metal film on the convex portion is removed by mechanical friction between the abrasive and the convex portion of the metal film.

  On the other hand, tantalum, a tantalum alloy, a tantalum compound, or the like is formed as a barrier layer in a lower layer such as copper or copper alloy of the wiring to prevent copper diffusion into the interlayer insulating film. Therefore, it is necessary to remove the exposed barrier layer by CMP except for the wiring portion in which copper or a copper alloy is embedded. However, since the barrier layer is generally harder than copper or copper alloy, CMP using a combination of polishing materials for copper or copper alloy often does not provide a sufficient CMP rate.

  On the other hand, tantalum, tantalum alloy, or tantalum compound used as a barrier layer is chemically stable and difficult to etch, and has high hardness, so mechanical polishing is not as easy as copper or copper alloy. In recent years, noble metal materials such as ruthenium, ruthenium alloys, and ruthenium compounds have been studied as materials for the barrier layer. Precious metal materials such as ruthenium, ruthenium alloys, and ruthenium compounds have a lower resistivity than tantalum, tantalum alloys, or tantalum compounds, and can be deposited by chemical vapor deposition (CVD) for thinner wiring. It is excellent in that it can be handled. However, noble metal materials such as ruthenium, ruthenium alloys, and ruthenium compounds are difficult to polish because they are chemically stable and high in hardness, like tantalum, tantalum alloys, or tantalum compounds.

The noble metal material is used as an electrode material in a manufacturing process of a DRAM capacitor structure, for example. Then, polishing using a polishing composition is used to remove a part of a portion made of a material containing a noble metal such as ruthenium simple substance or ruthenium oxide (RuO _x ). However, similar to the aforementioned noble metal materials for the barrier layer, removal of the chemically stable noble metal-containing material is generally time consuming, and this type of polishing composition further increases throughput. There is a strong need for improvement.

  Abrasives used in CMP generally include an oxidizer and abrasive grains. It is believed that the basic mechanism of CMP by this CMP abrasive is that the surface of the metal film is first oxidized by an oxidizing agent, and the resulting oxide layer on the surface of the metal film is scraped off by abrasive grains. Since the oxide layer on the surface of the metal film in the concave portion does not touch the polishing pad so much and the effect of scraping off by the abrasive grains is not exerted, the metal film on the convex portion is removed and the substrate surface is flattened with the progress of CMP.

  In CMP, a high polishing rate with respect to a wiring metal, stability of the polishing rate, and a low defect density on the polishing surface are required. However, since a film containing ruthenium is chemically more stable and harder than other damascene wiring metal films such as copper and tungsten, it is difficult to polish. As a polishing liquid for a film containing such a noble metal, particularly a film containing ruthenium, for example, Patent Document 2 proposes a polishing liquid containing abrasive grains, an oxidizing agent, and benzotriazole.

U.S. Pat. No. 4,944,836 JP 2004-172326 A

  However, in the polishing liquid described in Patent Document 2, it takes time to remove the chemically stable noble metal, and therefore further improvement for improving the throughput has been demanded.

  Therefore, an object of the present invention is to provide a polishing composition that is suitable for polishing a material containing a noble metal and can improve throughput.

  In order to solve the above-mentioned problems, the present inventors have intensively studied. As a result, it has been found that the above problem can be solved by using a polishing composition containing hypohalite ions, a complexing agent, and water. And based on the said knowledge, it came to complete this invention.

  That is, the present invention is a polishing composition used for polishing an object to be polished having a layer containing a noble metal, comprising a hypohalite ion, a complexing agent, and water, and having a pH Is a polishing composition having 5.5 or more.

  ADVANTAGE OF THE INVENTION According to this invention, it is suitable for grinding | polishing of the material containing a noble metal, and the polishing composition which can improve a throughput can be provided.

It is a section schematic diagram showing an example of the polish subject concerning the present invention.

  The present invention is a polishing composition for use in polishing a polishing object having a layer containing a noble metal, comprising hypohalite ions, a complexing agent and water, and having a pH of 5 It is polishing composition which is 0.5 or more. With such a configuration, the polishing rate of the material containing the noble metal is improved, and high throughput can be achieved.

  Although the detailed reason why the polishing rate of a material containing a noble metal is improved by using the polishing composition of the present invention is unknown, hypohalite ions act on the noble metal, so to speak, a noble metal halide is used as an intermediate. Form. Thereafter, it is considered that the polishing rate of the noble metal is improved by the complexing agent contained in the polishing composition acting on the noble metal halide to form a complex and dissolving it in water. In addition, the said mechanism is based on estimation and this invention is not limited to the said mechanism at all.

[Polishing object]
First, an example of a polishing object and a semiconductor wiring process according to the present invention will be described with reference to FIG. The semiconductor wiring process usually includes the following steps.

  As shown in FIG. 1A, a barrier layer 13 and a metal wiring layer 14 are sequentially formed on an insulator layer 12 having a trench 11 provided on a substrate (not shown). In the present invention, the barrier layer 13 contains a noble metal. Prior to the formation of the metal wiring layer 14, the barrier layer 13 is formed on the insulator layer 12 so as to cover the surface of the insulator layer 12. The thickness of the barrier layer 13 is smaller than the depth and width of the trench 11. Following the formation of the barrier layer 13, the metal wiring layer 14 is formed on the barrier layer 13 so that at least the trench 11 is filled.

  When removing at least the outer portion of the metal wiring layer 14 and the outer portion of the barrier layer 13 by CMP, first, most of the outer portion of the metal wiring layer 14 is removed as shown in FIG. Next, as shown in FIG. 1C, the remainder of the outer portion of the metal wiring layer 14 is removed to expose the upper surface of the outer portion of the barrier layer 13.

  Thereafter, at least a portion of the metal wiring layer 14 located outside the trench 11 (outside portion of the metal wiring layer 14) and a portion of the barrier layer 13 located outside the trench 11 (outside portion of the barrier layer 13) are obtained by CMP. Remove. As a result, as shown in FIG. 1D, at least a part of the portion of the barrier layer 13 located in the trench 11 (inner portion of the barrier layer 13) and the metal wiring layer 14 located in the trench 11. At least a part of the portion (the inner portion of the metal wiring layer 14) remains on the insulator layer 12. That is, a part of the barrier layer 13 and a part of the metal wiring layer 14 remain inside the trench 11. Thus, the portion of the metal wiring layer 14 remaining inside the trench 11 functions as a wiring.

  The polishing composition of the present invention is used for polishing a polishing object having a layer containing a noble metal as described above.

  The noble metal contained in the noble metal-containing layer such as the barrier layer 13 and the capacitor electrode material in FIG. 1 is not particularly limited, and examples thereof include gold, silver, platinum, palladium, rhodium, ruthenium, iridium, and osmium. These noble metals may be contained in a layer containing the noble metal in the form of an alloy or a noble metal compound. Ruthenium, silver, gold, palladium, platinum, rhodium, iridium and osmium are preferred. These noble metals may be used alone or in combination of two or more.

  Moreover, the metal contained in the metal wiring layer 14 is not particularly limited, and examples thereof include copper, aluminum, hafnium, cobalt, nickel, titanium, and tungsten. These metals may be contained in the metal wiring layer 14 in the form of an alloy or a metal compound. Copper or copper alloy is preferable. These metals may be used alone or in combination of two or more.

  Next, the structure of the polishing composition of the present invention will be described in detail.

[Hypohalite ion]
Examples of the hypohalite ions used in the present invention include hypofluorite ions, hypochlorite ions, hypobromite ions, and hypoiodite ions. These hypohalous acid ions may be used alone or in combination of two or more.

In order to obtain the polishing composition of the present invention containing the above hypohalite ion, a compound that generates hypohalite ion, for example, hypohalous acid or a salt thereof is added to the composition, and the composition The pH may be 5.5 or more. Examples of the hypohalous acid or a salt thereof include hypochlorous acid (HFO), hypochlorous acid (HClO), hypobromous acid (HBrO), hypoiodous acid (HIO) and the like. Halogen acid; lithium hypofluorite (LiFO), sodium hypofluorite (NaFO), potassium hypofluorite (KFO), magnesium hypofluorite (Mg (FO) ₂ ), calcium hypofluorite (Ca (FO) ₂ ), hypofluorite salts such as barium hypofluorite (Ba (FO) ₂ ); lithium hypochlorite (LiClO), sodium hypochlorite (NaClO), potassium hypochlorite (KClO), magnesium hypochlorite (Mg _{(ClO) 2),} calcium hypochlorite (Ca _{(ClO) 2),} barium hypochlorite _{(Ba (ClO) 2),} t- hypochlorite Bed Le (t-BuClO), ammonium hypochlorite _(NH 4 ClO), salts of hypochlorous acid hypochlorous acid triethanolamine _{((CH 2 CH 2 OH)} 3 N · ClO) and the like; hypobromous Lithium oxide (LiBrO), sodium hypobromite (NaBrO), potassium hypobromite (KBrO), magnesium hypobromite (Mg (BrO) ₂ ), calcium hypobromite (Ca (BrO) ₂ ), Hypobromite such as barium hypobromite (Ba (BrO) ₂ ), ammonium hypobromite (NH ₄ BrO), triethanolamine hypobromite ((CH ₂ CH ₂ OH) ₃ N · BrO) salt; lithium hypoiodite (LiIO), sodium hypoiodite (NaIO), potassium hypoiodite (KIO), magnesium hypoiodous acid (Mg _{(IO) 2),} Nitrite iodate calcium (Ca _{(IO) 2),} hypoiodous acid barium (Ba _{(IO) 2),} hypoiodous acid ammonium _(NH 4 IO), hypoiodite triethanolamine _((CH 2 CH 2 OH ) Hypoiodic acid salts such as ₃ N · IO). These hypohalous acids or salts thereof can be used alone or in combination of two or more.

  Among these hypohalous acids or salts thereof, salts of potassium hypochlorite, ammonium hypochlorite, hypochlorous acid and nitrogen-based amines are preferable from the viewpoint of preventing metal contamination.

Moreover, the polishing composition of the present invention is obtained by using together a halogen-containing compound other than hypohalous acid or a salt thereof and an additive such as an oxidizing agent or a reducing agent as the compound for generating the hypohalous acid ion. You can get things. Examples of such halogen-containing compounds include, for example, halogen acids and salts thereof, chlorous acid (HClO ₂ ), bromous acid (HBrO ₂ ), iodic acid (HIO ₂ ), sodium chlorite (NaClO _2). ), Potassium chlorite (KClO ₂ ), sodium bromite (NaBrO ₂ ), potassium bromite (KBrO ₂ ) and the like, or salts thereof; sodium chlorate (NaClO ₃ ), potassium chlorate (KClO) ₃ ) Halogen acids such as silver chlorate (AgClO ₃ ), barium chlorate (Ba (ClO ₃ ) ₂ ), sodium bromate (NaBrO ₃ ), potassium bromate (KBrO ₃ ), sodium iodate (NaIO ₃ ) or a salt thereof; perchlorate (HClO _4), perbromic acid (HBrO _4), periodic acid _(HIO 4), over-iodine Sodium (NaIO _4), potassium periodate _(KIO 4), perhalogen acids or salts such as periodic acid tetrabutylammonium _{((C 4 H 9) 4} NIO 4) can be mentioned. Examples of the additive include potassium chloride, potassium persulfate, potassium chlorite, and potassium sulfite. The halogen-containing compound and the additive can be used alone or in admixture of two or more.

  The lower limit of the content (concentration) of hypohalite ion in the polishing composition of the present invention is not particularly limited because it exhibits an effect even with a small amount, but it is 0.01 mM (mmol / L) or more. Preferably, it is 0.1 mM (mmol / L) or more, and more preferably 1.0 mM (mmol / L) or more. Further, the upper limit of the content (concentration) of hypohalite ion in the polishing composition of the present invention is preferably 1000 mM (mmol / L) or less, and preferably 500 mM (mmol / L) or less. More preferably, it is more preferably 300 mM (mmol / L) or less. If it is this range, the effect of this invention can be acquired more efficiently.

  The polishing composition of the present invention has a pH of 5.5 or higher. This is because the hypohalite ions must be generated and stably present in the polishing composition. The pH is preferably 6.0 or higher, more preferably 7.0 or higher, and still more preferably 9.0 or higher.

  The pH can be adjusted by adding an appropriate amount of a pH adjusting agent. The pH adjuster used as necessary to adjust the pH of the polishing composition to a desired value may be either acid or alkali, and may be either an inorganic compound or an organic compound. Good. Specific examples of the acid include inorganic acids such as sulfuric acid, nitric acid, boric acid, carbonic acid, hypophosphorous acid, phosphorous acid and phosphoric acid; formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid , N-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycol Acids, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid and lactic acid and other carboxylic acids, and methanesulfonic acid, And organic acids such as organic sulfuric acid such as ethanesulfonic acid and isethionic acid. Specific examples of the alkali include ammonia, amines such as ethylenediamine and piperazine, and quaternary ammonium salts such as tetramethylammonium and tetraethylammonium. These pH regulators can be used alone or in combination of two or more.

[Complexing agent]
The complexing agent contained in the polishing composition has an action of chemically etching the surface of the polishing object, and improves the polishing rate of the polishing object by the polishing composition.

  Examples of complexing agents that can be used include inorganic acids or salts thereof, organic acids or salts thereof, nitrile compounds, amino acids, and chelating agents. These complexing agents may be used alone or in admixture of two or more. The complexing agent may be a commercially available product or a synthetic product.

  Specific examples of the inorganic acid include hydrochloric acid, sulfuric acid, nitric acid, carbonic acid, boric acid, tetrafluoroboric acid, hypophosphorous acid, phosphorous acid, phosphoric acid, pyrophosphoric acid and the like.

  Specific examples of the organic acid include, for example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, monovalent carboxylic acids such as n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, lactic acid, glycolic acid, glyceric acid, benzoic acid, salicylic acid; oxalic acid, malonic acid, succinic acid, Examples thereof include carboxylic acids such as glutaric acid, gluconic acid, adipic acid, pimelic acid, maleic acid, phthalic acid, fumaric acid, malic acid, tartaric acid and citric acid. Also, sulfonic acids such as methanesulfonic acid, ethanesulfonic acid and isethionic acid can be used.

  As a complexing agent, the inorganic acid or the salt of the organic acid may be used. In particular, when a salt of a weak acid and a strong base, a salt of a strong acid and a weak base, or a salt of a weak acid and a weak base is used, a pH buffering action can be expected. Examples of such salts include, for example, potassium chloride, sodium sulfate, potassium nitrate, potassium carbonate, potassium tetrafluoroborate, potassium pyrophosphate, potassium oxalate, trisodium citrate, (+)-potassium tartrate, hexafluoro A potassium phosphate etc. are mentioned.

  Specific examples of the nitrile compound include acetonitrile, aminoacetonitrile, propionitrile, butyronitrile, isobutyronitrile, benzonitrile, glutaronitrile, methoxyacetonitrile, and the like.

  Specific examples of amino acids include glycine, α-alanine, β-alanine, N-methylglycine, N, N-dimethylglycine, 2-aminobutyric acid, norvaline, valine, leucine, norleucine, isoleucine, phenylalanine, proline, sarcosine, Ornithine, lysine, taurine, serine, threonine, homoserine, tyrosine, bicine, tricine, 3,5-diiodo-tyrosine, β- (3,4-dihydroxyphenyl) -alanine, thyroxine, 4-hydroxy-proline, cysteine, methionine , Ethionine, lanthionine, cystathionine, cystine, cysteic acid, aspartic acid, glutamic acid, S- (carboxymethyl) -cysteine, 4-aminobutyric acid, asparagine, glutamine, azaserine, arginine, canavanine, cytosine Phosphorus, .delta.-hydroxy - lysine, creatine, histidine, 1-methyl - histidine, 3-methyl - include histidine and tryptophan.

  Specific examples of chelating agents include nitrilotriacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, N, N, N-trimethylenephosphonic acid, ethylenediamine-N, N, N ′, N′-tetramethylenesulfonic acid, transcyclohexane Diamine tetraacetic acid, 1,2-diaminopropanetetraacetic acid, glycol ether diamine tetraacetic acid, ethylenediamine orthohydroxyphenylacetic acid, ethylenediamine disuccinic acid (SS form), N- (2-carboxylateethyl) -L-aspartic acid, β -Alanine diacetate, 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, N, N'-bis (2-hydroxybenzyl) ethylenediamine-N, N'-diacetic acid 1,2-dihydroxybenzene-4,6 Such as disulfonic acid and the like.

  Among these, at least one selected from the group consisting of an inorganic acid or a salt thereof, a carboxylic acid or a salt thereof, and a nitrile compound is preferable. From the viewpoint of stability of a complex structure with a noble metal compound, an inorganic acid or a salt thereof Is more preferable.

  The lower limit of the content (concentration) of the complexing agent in the polishing composition is not particularly limited because it exhibits an effect even in a small amount, but is preferably 0.01 mM (mmol / L) or more, More preferably, it is 0.1 mM (mmol / L), and even more preferably 1.0 mM (mmol / L) or more. Further, the upper limit of the content (concentration) of the complexing agent in the polishing composition of the present invention is preferably 1000 mM (mmol / L) or less, and more preferably 500 mM (mmol / L) or less. More preferably, it is 300 mM (mmol / L) or less. If it is this range, the effect of this invention can be acquired more efficiently.

[water]
The polishing composition of the present invention contains water as a dispersion medium or solvent for dispersing or dissolving each component. From the viewpoint of suppressing the inhibition of the action of other components, water containing as little impurities as possible is preferable. Specifically, after removing impurity ions with an ion exchange resin, pure water from which foreign matters are removed through a filter is used. Water, ultrapure water, or distilled water is preferred.

[Other ingredients]
The polishing composition of the present invention dissolves abrasive grains, metal anticorrosives, antiseptics, antifungal agents, oxidizing agents, reducing agents, water-soluble polymers, surfactants, and poorly soluble organic substances as necessary. It may further contain other components such as an organic solvent. Hereinafter, abrasive grains and metal anticorrosive agents, which are other preferable components, will be described.

[Abrasive]
The abrasive grains contained in the polishing composition have an action of mechanically polishing the object to be polished, and improve the polishing rate of the object to be polished by the polishing composition.

  The abrasive used may be any of inorganic particles, organic particles, and organic-inorganic composite particles. Specific examples of the inorganic particles include particles made of metal oxides such as silica, alumina, ceria, titania, silicon nitride particles, silicon carbide particles, and boron nitride particles. Specific examples of the organic particles include polymethyl methacrylate (PMMA) particles. These abrasive grains may be used alone or in combination of two or more. The abrasive grains may be commercially available products or synthetic products.

  Among these abrasive grains, silica is preferable, and colloidal silica is particularly preferable.

  The abrasive grains may be surface-modified. Since ordinary colloidal silica has a zeta potential value close to zero under acidic conditions, silica particles are not electrically repelled with each other under acidic conditions and are likely to agglomerate. On the other hand, abrasive grains whose surfaces are modified so that the zeta potential has a relatively large negative value even under acidic conditions are strongly repelled from each other and dispersed well even under acidic conditions, resulting in storage of the polishing composition. Stability will be improved. Such surface-modified abrasive grains can be obtained, for example, by mixing a metal such as aluminum, titanium or zirconium or an oxide thereof with the abrasive grains and doping the surface of the abrasive grains. Of these, colloidal silica having an organic acid immobilized thereon is particularly preferable. The organic acid is immobilized on the surface of the colloidal silica contained in the polishing composition, for example, by chemically bonding a functional group of the organic acid to the surface of the colloidal silica. If the colloidal silica and the organic acid are simply allowed to coexist, the organic acid is not fixed to the colloidal silica. If sulfonic acid, which is a kind of organic acid, is immobilized on colloidal silica, for example, a method described in “Sulfonic acid-functionalized silica through quantitative oxidation of thiol groups”, Chem. Commun. 246-247 (2003). It can be carried out. Specifically, a silane coupling agent having a thiol group such as 3-mercaptopropyltrimethoxysilane is coupled to colloidal silica, and then the sulfonic acid is immobilized on the surface by oxidizing the thiol group with hydrogen peroxide. The colloidal silica thus obtained can be obtained. Alternatively, if the carboxylic acid is immobilized on colloidal silica, for example, “Novel Silane Coupling Agents Containing a Photolabile 2-Nitrobenzyl Ester for Introduction of a Carboxy Group on the Surface of Silica Gel”, Chemistry Letters, 3, 228- 229 (2000). Specifically, colloidal silica having a carboxylic acid immobilized on the surface can be obtained by irradiating light after coupling a silane coupling agent containing a photoreactive 2-nitrobenzyl ester to colloidal silica. .

  The lower limit of the average primary particle diameter of the abrasive grains is preferably 5 nm or more, more preferably 7 nm or more, and further preferably 10 nm or more. Further, the upper limit of the average primary particle diameter of the abrasive grains is preferably 500 nm or less, more preferably 100 nm or less, and further preferably 70 nm or less. Within such a range, the polishing rate of the object to be polished by the polishing composition is improved, and the occurrence of dishing on the surface of the object to be polished after polishing with the polishing composition is further suppressed. Can do. In addition, the average primary particle diameter of an abrasive grain is calculated based on the specific surface area of the abrasive grain measured by BET method, for example.

  The lower limit of the content of the abrasive grains in the polishing composition is preferably 0.005% by mass or more, more preferably 0.5% by mass or more, and further preferably 1% by mass or more. Most preferably, it is 3 mass% or more. Further, the upper limit of the content of the abrasive grains in the polishing composition is preferably 50% by mass or less, more preferably 30% by mass, and further preferably 15% by mass or less. Within such a range, the polishing rate of the polishing object can be improved, and the cost of the polishing composition can be reduced, and dishing is performed on the surface of the polishing object after polishing using the polishing composition. Can be further suppressed.

[Metal anticorrosive]
By adding a metal anticorrosive to the polishing composition, it is possible to further suppress the formation of a dent on the side of the wiring in the polishing using the polishing composition. Moreover, it can suppress more that dishing arises on the surface of the grinding | polishing target object after grind | polishing using a polishing composition.

  The metal anticorrosive that can be used is not particularly limited, but is preferably a heterocyclic compound or a surfactant. The number of heterocyclic rings in the heterocyclic compound is not particularly limited. The heterocyclic compound may be a monocyclic compound or a polycyclic compound having a condensed ring. These metal anticorrosives may be used alone or in combination of two or more. In addition, as the metal anticorrosive, a commercially available product or a synthetic product may be used.

  Specific examples of heterocyclic compounds that can be used as metal anticorrosives include, for example, pyrrole compounds, pyrazole compounds, imidazole compounds, triazole compounds, tetrazole compounds, pyridine compounds, pyrazine compounds, pyridazine compounds, pyridine compounds, indolizine compounds, indoles. Compound, isoindole compound, indazole compound, purine compound, quinolidine compound, quinoline compound, isoquinoline compound, naphthyridine compound, phthalazine compound, quinoxaline compound, quinazoline compound, cinnoline compound, buteridine compound, thiazole compound, isothiazole compound, oxazole compound, iso Examples thereof include nitrogen-containing heterocyclic compounds such as oxazole compounds and furazane compounds.

  More specific examples include pyrazole compounds such as 1H-pyrazole, 4-nitro-3-pyrazolecarboxylic acid, 3,5-pyrazolecarboxylic acid, 3-amino-5-phenylpyrazole, 5 -Amino-3-phenylpyrazole, 3,4,5-tribromopyrazole, 3-aminopyrazole, 3,5-dimethylpyrazole, 3,5-dimethyl-1-hydroxymethylpyrazole, 3-methylpyrazole, 1-methyl Pyrazole, 3-amino-5-methylpyrazole, 4-amino-pyrazolo [3,4-d] pyrimidine, allopurinol, 4-chloro-1H-pyrazolo [3,4-D] pyrimidine, 3,4-dihydroxy-6 -Methylpyrazolo (3,4-B) -pyridine, 6-methyl-1H-pyrazolo [3,4-b] pyridine - amine.

  Examples of imidazole compounds include, for example, imidazole, 1-methylimidazole, 2-methylimidazole, 4-methylimidazole, 1,2-dimethylpyrazole, 2-ethyl-4-methylimidazole, 2-isopropylimidazole, benzimidazole, 5,6-dimethylbenzimidazole, 2-aminobenzimidazole, 2-chlorobenzimidazole, 2-methylbenzimidazole, 2- (1-hydroxyethyl) benzimidazole, 2-hydroxybenzimidazole, 2-phenylbenzimidazole, 2 , 5-dimethylbenzimidazole, 5-methylbenzimidazole, 5-nitrobenzimidazole, 1H-purine and the like.

  Examples of triazole compounds include, for example, 1,2,3-triazole, 1,2,4-triazole, 1-methyl-1,2,4-triazole, methyl-1H-1,2,4-triazole-3. -Carboxylate, 1,2,4-triazole-3-carboxylic acid, methyl 1,2,4-triazole-3-carboxylate, 1H-1,2,4-triazole-3-thiol, 3,5-diamino -1H-1,2,4-triazole, 3-amino-1,2,4-triazole-5-thiol, 3-amino-1H-1,2,4-triazole, 3-amino-5-benzyl-4H -1,2,4-triazole, 3-amino-5-methyl-4H-1,2,4-triazole, 3-nitro-1,2,4-triazole, 3-bromo-5-nitro-1, , 4-tri Sol, 4- (1,2,4-triazol-1-yl) phenol, 4-amino-1,2,4-triazole, 4-amino-3,5-dipropyl-4H-1,2,4-triazole 4-amino-3,5-dimethyl-4H-1,2,4-triazole, 4-amino-3,5-dipeptyl-4H-1,2,4-triazole, 5-methyl-1,2,4 -Triazole-3,4-diamine, 1H-benzotriazole, 1-hydroxybenzotriazole, 1-aminobenzotriazole, 1-carboxybenzotriazole, 5-chloro-1H-benzotriazole, 5-nitro-1H-benzotriazole, 5-carboxy-1H-benzotriazole, 5-methyl-1H-benzotriazole, 5,6-dimethyl-1H-benzotriazo 1- (1 ′, 2′-dicarboxyethyl) benzotriazole, 1- [N, N-bis (hydroxyethyl) aminomethyl] benzotriazole, 1- [N, N-bis (hydroxyethyl) aminomethyl ] -5-methylbenzotriazole, 1- [N, N-bis (hydroxyethyl) aminomethyl] -4-methylbenzotriazole, and the like.

  Examples of the tetrazole compound include 1H-tetrazole, 5-methyltetrazole, 5-aminotetrazole, and 5-phenyltetrazole.

  Examples of indazole compounds include, for example, 1H-indazole, 5-amino-1H-indazole, 5-nitro-1H-indazole, 5-hydroxy-1H-indazole, 6-amino-1H-indazole, 6-nitro-1H -Indazole, 6-hydroxy-1H-indazole, 3-carboxy-5-methyl-1H-indazole and the like.

  Examples of indole compounds include 1H-indole, 1-methyl-1H-indole, 2-methyl-1H-indole, 3-methyl-1H-indole, 4-methyl-1H-indole, 5-methyl-1H- Indole, 6-methyl-1H-indole, 7-methyl-1H-indole, 4-amino-1H-indole, 5-amino-1H-indole, 6-amino-1H-indole, 7-amino-1H-indole, 4-hydroxy-1H-indole, 5-hydroxy-1H-indole, 6-hydroxy-1H-indole, 7-hydroxy-1H-indole, 4-methoxy-1H-indole, 5-methoxy-1H-indole, 6- Methoxy-1H-indole, 7-methoxy-1H-indole, 4-chloro-1H- Ndole, 5-chloro-1H-indole, 6-chloro-1H-indole, 7-chloro-1H-indole, 4-carboxy-1H-indole, 5-carboxy-1H-indole, 6-carboxy-1H-indole, 7-carboxy-1H-indole, 4-nitro-1H-indole, 5-nitro-1H-indole, 6-nitro-1H-indole, 7-nitro-1H-indole, 4-nitrile-1H-indole, 5- Nitrile-1H-indole, 6-nitrile-1H-indole, 7-nitrile-1H-indole, 2,5-dimethyl-1H-indole, 1,2-dimethyl-1H-indole, 1,3-dimethyl-1H- Indole, 2,3-dimethyl-1H-indole, 5-amino-2,3-dimethyl-1H- Ndole, 7-ethyl-1H-indole, 5- (aminomethyl) indole, 2-methyl-5-amino-1H-indole, 3-hydroxymethyl-1H-indole, 6-isopropyl-1H-indole, 5-chloro -2-methyl-1H-indole and the like.

  Among these, preferred heterocyclic compounds are triazole compounds, and in particular, 1H-benzotriazole, 5-methyl-1H-benzotriazole, 5,6-dimethyl-1H-benzotriazole, 1- [N, N-bis (hydroxy Ethyl) aminomethyl] -5-methylbenzotriazole, 1- [N, N-bis (hydroxyethyl) aminomethyl] -4-methylbenzotriazole, 1,2,3-triazole, and 1,2,4-triazole Is preferred. Since these heterocyclic compounds have high chemical or physical adsorptive power to the surface of the object to be polished, a stronger protective film can be formed on the surface of the object to be polished. This is advantageous in improving the flatness of the surface of the object to be polished after polishing using the polishing composition of the present invention.

  Further, the surfactant used as the metal anticorrosive may be any of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

  Examples of anionic surfactants include, for example, polyoxyethylene alkyl ether acetic acid, polyoxyethylene alkyl sulfuric acid ester, alkyl sulfuric acid ester, polyoxyethylene alkyl ether sulfuric acid, alkyl ether sulfuric acid, alkylbenzene sulfonic acid, alkyl phosphoric acid ester , Polyoxyethylene alkyl phosphate ester, polyoxyethylene sulfosuccinic acid, alkyl sulfosuccinic acid, alkyl naphthalene sulfonic acid, alkyl diphenyl ether disulfonic acid, and salts thereof.

  Examples of the cationic surfactant include alkyl trimethyl ammonium salt, alkyl dimethyl ammonium salt, alkyl benzyl dimethyl ammonium salt, alkyl amine salt and the like.

  Examples of amphoteric surfactants include alkyl betaines and alkyl amine oxides.

  Examples of nonionic surfactants include, for example, polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, and alkyl alkanolamide. Is mentioned.

  Among these, preferable surfactants are polyoxyethylene alkyl ether acetate, polyoxyethylene alkyl ether sulfate, alkyl ether sulfate, alkylbenzene sulfonate, and polyoxyethylene alkyl ether. Since these surfactants have a high chemical or physical adsorption force to the surface of the object to be polished, a stronger protective film can be formed on the surface of the object to be polished. This is advantageous in improving the flatness of the surface of the object to be polished after polishing using the polishing composition of the present invention.

  The lower limit of the content of the metal anticorrosive in the polishing composition is preferably 0.001 g / L or more, more preferably 0.005 g / L or more, and 0.01 g / L or more. Is more preferable. Further, the upper limit of the content of the metal anticorrosive in the polishing composition is preferably 10 g / L or less, more preferably 5 g / L or less, and further preferably 1 g / L or less. If it is such a range, the flatness of the surface of the grinding | polishing target object after grind | polishing using a polishing composition will improve, and the grinding | polishing speed | rate of the grinding | polishing target object by polishing composition will improve.

[Method for producing polishing composition]
The method for producing the polishing composition of the present invention is not particularly limited, and for example, by stirring and mixing a compound that generates hypohalite ions, a complexing agent, and, if necessary, other components in water. Can be obtained.

  Although the temperature at the time of mixing each component is not specifically limited, 10-40 degreeC is preferable and you may heat in order to raise a dissolution rate. Further, the mixing time is not particularly limited.

[Polishing method and substrate manufacturing method]
As described above, the polishing composition of the present invention is suitably used for polishing a polishing object having a layer containing a noble metal. Therefore, this invention provides the grinding | polishing method which grind | polishes the grinding | polishing target object which has a layer containing a noble metal with the polishing composition of this invention. Moreover, this invention provides the manufacturing method of a board | substrate including the process of grind | polishing the grinding | polishing target object which has a layer containing a noble metal with the said grinding | polishing method.

  As a polishing apparatus, a general holder having a polishing surface plate on which a holder for holding a substrate having a polishing object and a motor capable of changing the number of rotations are attached and a polishing pad (polishing cloth) can be attached. A polishing apparatus can be used.

  As the polishing pad, a general nonwoven fabric, polyurethane, porous fluororesin, or the like can be used without particular limitation. It is preferable that the polishing pad is grooved so that the polishing liquid accumulates.

  The polishing conditions are not particularly limited, and for example, the rotation speed of the polishing platen is preferably 10 to 500 rpm, and the pressure (polishing pressure) applied to the substrate having the object to be polished is preferably 0.5 to 10 psi. The method of supplying the polishing composition to the polishing pad is not particularly limited, and for example, a method of continuously supplying with a pump or the like is employed. Although the supply amount is not limited, it is preferable that the surface of the polishing pad is always covered with the polishing composition of the present invention.

  After polishing, the substrate is washed in running water, and water droplets adhering to the substrate are removed by drying with a spin dryer or the like, and dried to obtain a substrate having a layer containing a noble metal.

  The present invention will be described in further detail using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples.

(Examples 1-14, Comparative Examples 1-57)
As shown in Table 3-1 to Table 3-3, compounds that generate hypohalite ions or other compounds (in the “Compound” column in the table), complexing agents, and abrasives as necessary By stirring and mixing in water (mixing temperature: about 25 ° C., mixing time: about 10 minutes), polishing compositions of Examples 1 to 14 and Comparative Examples 1 to 57 were prepared. The pH of the composition was adjusted by adding potassium hydroxide (KOH) and confirmed with a pH meter.

  The types of abrasive grains and compounds shown in Table 3-1 to Table 3-3 are shown in Table 1 below.

  Using the obtained polishing composition, the polishing rate was measured when the surface of the ruthenium (Ru) wafer was polished for 60 seconds under the polishing conditions shown in Table 2 below. The polishing rate was determined by dividing the difference in Ru wafer thickness before and after polishing measured by using a sheet resistance measuring instrument based on the DC 4 probe method by the polishing time.

  The measurement results of the polishing rate are shown in Tables 3-1 to 3-3 below.

  As shown in Tables 3-1 to 3-3, the polishing composition of the present invention (Examples 1 to 14) has a higher ruthenium film polishing rate than the comparative polishing composition. I understood.

11 Trench,
12 Insulating layer,
13 Barrier layer (layer containing noble metal),
14 Metal wiring layer.

Claims (4)

A polishing composition used for polishing a polishing object having a layer containing a noble metal,
Hypohalite ion,
A complexing agent;
water and,
And a polishing composition having a pH of 5.5 or higher.   The polishing composition according to claim 1, wherein the complexing agent is at least one selected from the group consisting of inorganic acids or salts thereof, carboxylic acids or salts thereof, and nitrile compounds.   The grinding | polishing method which grind | polishes the grinding | polishing target object which has a layer containing a noble metal with the polishing composition of Claim 1 or 2.   The manufacturing method of a board | substrate including the process of grind | polishing the grinding | polishing target object which has a layer containing a noble metal with the grinding | polishing method of Claim 3.

Images