JP2009064881A - Composition for polishing metal, and chemical mechanical polishing method using the composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for polishing metals which has the high selecting ratio of the polishing speed of a titanium barrier layer to the polishing speed of a conductive metal, and provide a chemical mechanical polishing method using the composition for polishing metals, in the chemical mechanical polishing process for semiconductor devices which suppresses effectively the occurrence of dishing and uses the titanium barrier layer while achieving a high polishing speed. <P>SOLUTION: The composition for polishing metals contains (a) a compound represented by a general formula (A), and (b) one or more kinds of compounds selected from the compounds represented by general formulas (B), (C), and (D), and further, (c) an oxidant. In these formulas, R<SP>1</SP>represents a hydrogen atom, an aliphatic group hydrocarbon radical, and the like, and R<SP>2</SP>represents a hydrogen atom, an aliphatic group hydrocarbon radical, aryl radical, or -C(=O)Z, and further, Z represents a hydrogen atom, an aliphatic group hydrocarbon radical, and the like, and moreover, R<SP>3</SP>-R<SP>10</SP>represent an hydrogen atom, alkyl radical, and the like. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to the manufacture of semiconductor devices, and more particularly to a metal polishing composition in a wiring process of semiconductor devices and a chemical mechanical polishing method using the same.

In the development of semiconductor devices typified by semiconductor integrated circuits (hereinafter sometimes referred to as “LSI”), in order to increase the integration and speed of semiconductor devices, wiring miniaturization and lamination methods are studied. Has been.
For this purpose, various techniques such as chemical mechanical polishing (hereinafter sometimes referred to as “CMP”) are employed. CMP is used to polish an interlayer insulating film (such as SiO ₂ ) or a metal thin film used for wiring to smooth the substrate or remove an excess metal thin film during wiring formation (for example, patents). Reference 1).

A general method of CMP is as follows.
A polishing pad is affixed on a circular polishing platen (platen), and the surface of the polishing pad is immersed in a polishing liquid. The surface of the substrate (wafer) is pressed against the polishing pad, and both the polishing surface plate and the substrate are rotated with a predetermined pressure (polishing pressure) applied from the back surface.
In CMP, the surface of the substrate is flattened by mechanical friction generated by the above operation.

  Conventionally, tungsten and aluminum have been widely used in interconnect structures as wiring metals. However, LSIs using copper, which has lower wiring resistance than these metals, have been developed with the aim of achieving higher performance. As a method for wiring this copper, a damascene method is known (for example, see Patent Document 2). Further, a dual damascene method in which a contact hole and a wiring groove are simultaneously formed in an interlayer insulating film and a metal is embedded in both has been widely used. As a target material for copper wiring, a high-purity copper target of five nines or more is shipped.

  However, in recent years, in order to miniaturize the wiring in accordance with the demand for higher density, improvements in the conductivity and electronic characteristics of the copper wiring are required. On the other hand, the use of a copper alloy obtained by adding a third component to high-purity copper has begun to be studied.

  There is also a need for high-speed metal polishing means that can increase productivity without contaminating these high-definition and high-purity materials. In particular, since copper is a soft metal, when polishing copper or copper alloy, only the center is polished deeper, resulting in a dish-like dent (dishing), or the surface of multiple wiring metal surfaces is a dish. A phenomenon (erosion) that forms a concave-shaped recess and a polishing flaw (scratch) are likely to occur, and an increasingly accurate polishing technique is required.

  In recent years, wafers have become larger in order to improve productivity. Currently, wafers with a diameter of 200 mm or more are widely used, and the manufacture of wafers with a diameter of 300 mm or more has started. As the size of the wafer increases, the difference in polishing rate between the central portion and the peripheral portion of the wafer tends to increase, and there is a strong demand for uniform polishing within the wafer surface.

On the other hand, as a chemical polishing method in which mechanical polishing means is not applied to copper and a copper alloy, a chemical polishing method based only on a dissolving action is disclosed (for example, see Patent Document 3).
However, in the chemical polishing method, since polishing is performed only by a chemical dissolution action, problems such as dishing of recesses, that is, dishing, are likely to occur compared to CMP in which the metal film of the protrusions is selectively chemically and mechanically polished. Flatness has become an issue.

In addition, when copper wiring is used in LSI manufacturing, a diffusion prevention layer called a barrier layer is generally provided between the wiring portion and the insulating layer in order to prevent copper ions from diffusing into the insulating material. The barrier layer is formed of a barrier material such as TaN, TaSiN, Ta, TiN, Ti, Nb, W, WN, Co, Zr, ZrN, Ru, and CuTa alloy, and is provided with one or more layers.
Since these barrier materials have a conductive property, the barrier material on the insulating layer must be completely removed in order to prevent an error such as a leakage current. For this removal processing, a method similar to that for polishing the bulk of the metal wiring material can be applied. This is what is called barrier CMP.

  Further, in the bulk polishing of copper, dishing is likely to occur particularly in a wide metal wiring portion. Therefore, it is desirable that the amount of polishing and removal can be adjusted between the wiring portion and the barrier portion in order to be finally flattened. For this reason, it is desired that the polishing liquid for barrier polishing has an optimal polishing selectivity of copper / barrier metal. Further, since the wiring pitch and the wiring density are different in each level of the wiring layer, it is further desirable that the polishing selectivity can be adjusted as appropriate.

  The metal polishing composition (metal polishing liquid) used for CMP generally contains solid abrasive grains (eg, alumina, silica) and an oxidizing agent (eg, hydrogen peroxide, persulfuric acid). It is considered that the basic mechanism of CMP using such a metal polishing liquid is that polishing is performed by oxidizing the metal surface with an oxidizing agent and removing the oxide film with abrasive grains (for example, non-polishing). (See Patent Document 1).

However, when performing CMP using a metal polishing liquid containing such solid abrasive grains, scratches (scratches), a phenomenon that the entire polishing surface is polished more than necessary (thinning), or the dishing, Erosion may occur.
In addition, in a cleaning process usually performed to remove the polishing liquid remaining on the semiconductor surface after polishing, the cleaning process becomes complicated by using a polishing liquid containing solid abrasive grains. In order to treat (waste liquid), there is a problem in terms of cost, for example, it is necessary to settle and separate solid abrasive grains.

As one means for solving these problems, a metal surface polishing method using a combination of a polishing liquid not containing abrasive grains and dry etching is disclosed (for example, see Non-Patent Document 2), and hydrogen peroxide / apple. A metal polishing liquid comprising acid / benzotriazole / ammonium polyacrylate and water has also been proposed (see, for example, Patent Document 4).
According to these methods, the metal film on the convex portion of the semiconductor substrate is selectively CMPed, and the metal film is left in the concave portion to obtain a desired conductor pattern. Since the friction with the polishing pad is much mechanically softer than that of the slurry containing the conventional solid abrasive grains, and CMP proceeds in this state, the generation of scratches is reduced.
However, there is a drawback that it is difficult to obtain a sufficient polishing rate due to a decrease in physical polishing power.

On the other hand, although the abrasive | polishing agent containing an abrasive grain has the characteristics that a high grinding | polishing rate is obtained, there existed a problem that dishing progressed easily.
For this reason, for the purpose of obtaining a high polishing rate without increasing the content of abrasive grains, a method using a specific organic acid in the polishing liquid (for example, see Patent Document 5), or selection of copper / tantalum. An organic acid structure suitable for a polishing liquid that is excellent in the ratio and can suppress the occurrence of dishing has been proposed (see, for example, Patent Document 6), but these organic acids that provide a high polishing rate and the occurrence of dishing are proposed. Even when a passive film forming agent capable of suppressing the above was used, dishing after the first copper polishing step was still not sufficient. In addition, in the chemical mechanical polishing process of a semiconductor device using a barrier layer made of titanium, there is a problem that the selection ratio of the polishing rate between the barrier layer made of titanium and the conductive metal is low.
US Pat. No. 4,944,836 JP-A-2-278822 JP 49-122432 A JP 2001-127019 A JP 2000-183004 A JP 2006-179845 A Journal of Electrochemical Society, 1991, Vol. 11, No. 11, pages 3460-3464 Journal of Electrochemical Society, 2000, Vol. 147, No. 10, pages 3907-3913

An object of the present invention is to effectively suppress the occurrence of dishing while achieving a high polishing rate, and in a chemical mechanical polishing process of a semiconductor device using a barrier layer made of titanium, An object of the present invention is to provide a metal polishing composition having a high polishing rate selectivity with a conductive metal.
Another object of the present invention is to provide a chemical mechanical polishing method using such a metal polishing composition.

In view of the above circumstances, the present inventors have conducted intensive research and found that the above-described problems can be solved by using two or more types of nitrogen-containing heterocyclic compounds that can suppress dissolution of copper. Completed the invention.
That is, the present invention is achieved by the following means.

<1> A metal polishing composition mainly used for chemical mechanical polishing of conductive metal wiring of a semiconductor device, wherein (a) a compound represented by the following general formula (A), (b) the following general formula A metal polishing composition comprising (B), at least one selected from the following general formula (C), and a compound represented by the following general formula (D), and (c) an oxidizing agent.

In the general formula (A), R ¹ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocycle, an alkoxy group, an amino group, a hydroxy group, a carboxy group, or a carbamoyl group, and R ² represents a hydrogen atom. , An aliphatic hydrocarbon group, an aryl group, or —C (═O) Z, wherein Z is a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, —NZ ¹ Z ² , or — OZ ³ is represented, and Z ¹ , Z ² and Z ³ each independently represent a hydrogen atom, an aliphatic hydrocarbon group or an aryl group.

In general formula (B), general formula (C), and general formula (D), R ³ , R ^5, and R ⁸ are each independently a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amino group, or Represents a hydroxy group, R ⁴ represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxy group, a carboxy group, or a carbamoyl group, and R ⁶ , R ⁷ , R ⁹ , and R ¹⁰ are Each independently represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an amino group, a hydroxy group, a carboxy group, or a carbamoyl group.

<2> The metal polishing composition according to <1>, further comprising (d) abrasive grains.
<3> The metal polishing composition as described in <1> or <2> above, further comprising (e) at least one selected from a surfactant and a water-soluble polymer compound.
<4> At least one selected from (e) a surfactant and a water-soluble polymer compound is a surfactant having at least one sulfo group and a phenyl group, or a water-soluble polymer compound having an amide bond. The metal polishing composition according to <3>, wherein the metal polishing composition is provided.

<5> (a) The compound represented by the general formula (A) is at least one selected from 5-amino-1H-tetrazole and the following compound group: The metal polishing composition according to any one of <4>.

<6> (a) The metal polishing composition according to <5>, wherein the compound represented by the general formula (A) is 5-amino-1H-tetrazole.
<7> The metal polishing composition according to any one of <1> to <6>, wherein R ⁴ in the general formula (B) is a substituent having an alkyl group.
<8> At least one selected from (e) a surfactant and a water-soluble polymer compound is alkyl diphenyl ether monosulfonic acid or a salt thereof, or alkyl diphenyl ether disulfonic acid or a salt thereof. The metal polishing composition according to <4>.

<9> The metal polishing composition according to any one of <1> to <8>, wherein the metal polishing composition is used for polishing conductive metal wiring composed of copper.
<10> In a chemical mechanical polishing step of a semiconductor device having a barrier layer containing titanium and a conductive metal wiring, the selectivity of the polishing rate between the barrier layer containing titanium and the conductive metal is 200 or more. The metal polishing composition according to any one of <1> to <9>, wherein

<11> A chemical mechanical polishing method for a semiconductor device in which a metal polishing composition is supplied to a polishing pad on a polishing surface plate, and the polishing pad is brought into contact with the surface to be polished of the semiconductor device and moved relative to the polishing pad. (A) a compound represented by the following general formula (A), (b) at least selected from compounds represented by the following general formula (B), the following general formula (C) and the following general formula (D) A chemical mechanical polishing method comprising polishing using a metal polishing composition containing one type and (c) an oxidizing agent.

In the general formula (A), R ¹ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocycle, an alkoxy group, an amino group, a hydroxy group, a carboxy group, or a carbamoyl group, and R ² represents a hydrogen atom. , An aliphatic hydrocarbon group, an aryl group, or —C (═O) Z, wherein Z is a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, —NZ ¹ Z ² , or — OZ ³ is represented, and Z ¹ , Z ² and Z ³ each independently represent a hydrogen atom, an aliphatic hydrocarbon group or an aryl group.

In general formula (B), general formula (C), and general formula (D), R ³ , R ^5, and R ⁸ are each independently a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amino group, or Represents a hydroxy group, R ⁴ represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxy group, a carboxy group, or a carbamoyl group, and R ⁶ , R ⁷ , R ⁹ , and R ¹⁰ are Each independently represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an amino group, a hydroxy group, a carboxy group, or a carbamoyl group.

<12> In the state where the surface to be polished of the semiconductor device is pressed against the polishing pad with a pressure of 20 kpa or less, polishing is performed by relatively moving the polishing pad and the surface to be polished of the semiconductor device. <11> The chemical mechanical polishing method according to <11>.
<13> The chemical mechanical polishing method according to <11> or <12>, wherein a supply flow rate of the metal polishing composition to the polishing pad is 190 mL / min or less.
<14> In a chemical mechanical polishing step of a semiconductor device having a barrier layer containing titanium and a conductive metal wiring, the selectivity of the polishing rate between the barrier layer containing titanium and the conductive metal is 200 or more. A chemical mechanical polishing method comprising polishing using the metal polishing composition according to any one of <1> to <10>.

  According to the present invention, while achieving a high polishing rate, effectively suppressing the occurrence of dishing, and in a chemical mechanical polishing process of a semiconductor device using a barrier layer made of titanium, a barrier layer made of titanium and It is possible to provide a metal polishing composition having a high polishing rate selectivity with respect to a conductive metal. Furthermore, according to the present invention, a chemical mechanical polishing method using such a metal polishing composition can be provided.

  Hereinafter, specific embodiments of the present invention will be described.

[Metal polishing composition]
The metal polishing composition of the present invention comprises (a) a compound represented by general formula (A), (b) a compound represented by general formula (B), general formula (C), and general formula (D). It contains at least one selected, and (c) an oxidizing agent.
Moreover, you may contain another compound as needed.
The metal polishing composition of the present invention usually takes the form of a slurry in which (d) abrasive grains are further dispersed in an aqueous solution in which each component is dissolved.
The metal polishing composition of the present invention is useful as a polishing composition used for chemical mechanical polishing of an object to be polished in the production of semiconductor devices.

  Although each component which comprises a metal polishing composition is explained in full detail below, each component may use only 1 type and may use 2 or more types together.

  In the present invention, the metal polishing composition (hereinafter also referred to as “polishing composition”) is not limited to the composition (concentration) used for polishing, but may be used as diluted as necessary during use. In the present invention, unless otherwise specified, it is referred to as a metal polishing composition. When the concentrated liquid is used for polishing, it is diluted with water or an aqueous solution and used for polishing, and the dilution ratio is generally 1 to 20 times by volume.

<(A) Compound represented by formula (A)>
The polishing composition of the present invention contains (a) a compound represented by the general formula (A).

In the general formula (A), R ¹ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocycle, an alkoxy group, an amino group, a hydroxy group, a carboxy group, or a carbamoyl group, and R ² represents a hydrogen atom. , An aliphatic hydrocarbon group, an aryl group, or —C (═O) Z, wherein Z is a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, —NZ ¹ Z ² , or — OZ ³ is represented, and Z ¹ , Z ² and Z ³ each independently represent a hydrogen atom, an aliphatic hydrocarbon group or an aryl group.

In the general formula (A), examples of the aliphatic hydrocarbon group represented by R ¹ include an alkyl group having 1 to 30 carbon atoms and an alkenyl group having 2 to 30 carbon atoms (in the present application, a cycloalkenyl group and a bicycloalkenyl group). Represents an unsaturated aliphatic group having a double bond including), or an alkynyl group.

The alkyl group represented by R ¹ includes a cycloalkyl group and a bicycloalkyl group, and also includes a linear, branched substituted or unsubstituted alkyl group.
The linear, branched substituted or unsubstituted alkyl group is preferably an alkyl group having 1 to 30 carbon atoms. Examples include methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, trifluoromethyl, and 2-ethylhexyl. Can be mentioned.

  The cycloalkyl group includes a substituted or unsubstituted cycloalkyl group. The substituted or unsubstituted cycloalkyl group is preferably a cycloalkyl group having 3 to 30 carbon atoms. Examples include a cyclohexyl group, a cyclopentyl group, and a 4-n-dodecylcyclohexyl group.

  Examples of the bicycloalkyl group include a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms. Examples include a bicyclo [1,2,2] heptan-2-yl group and a bicyclo [2,2,2] octan-3-yl group. Further, it includes a tricyclo structure having many ring structures. “Alkyl” in the substituents described below (for example, “alkyl” of an alkylthio group) also represents “alkyl” of such a concept.

The alkenyl group represented by R ¹ includes a cycloalkenyl group and a bicycloalkenyl group. The alkenyl group represents a linear, branched, or cyclic substituted or unsubstituted alkenyl group. As the alkenyl group, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms is preferable. Examples include vinyl group, allyl group, prenyl group, geranyl group, and oleyl group.

  The cycloalkenyl group is preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms. Examples include a 2-cyclopenten-1-yl group and a 2-cyclohexen-1-yl group.

  The bicycloalkenyl group includes a substituted or unsubstituted bicycloalkenyl group. The bicycloalkenyl group is preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. Examples include bicyclo [2,2,1] hept-2-en-1-yl group and bicyclo [2,2,2] oct-2-en-4-yl group.

The alkynyl group represented by R ¹ is preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, and examples thereof include an ethynyl group and a propargyl group.

The aryl group represented by R ¹ is preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, such as a phenyl group, p-tolyl group, naphthyl group, m-chlorophenyl group, o-hexadecanoylamino. A phenyl group is mentioned.

The heterocyclic group represented by R ¹ is a monovalent group obtained by removing one hydrogen atom from a substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, and these are further condensed. Also good.
These heterocyclic groups are preferably 5- or 6-membered heterocyclic groups, and the hetero atoms of the ring structure are preferably oxygen atoms, sulfur atoms and nitrogen atoms.
More preferably, it is a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms.

  Examples of the ring constituting the heterocyclic group without limiting the substitution position include pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, quinazoline ring, cinnoline ring, phthalazine ring, quinoxaline ring, Pyrrole ring, indole ring, furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrazole ring, oxazole ring, benzoxazole ring, thiazole ring, benzothiazole ring, isothiazole ring, benzisothiazole ring, thiadiazole ring, isoxazole Ring, benzisoxazole ring, pyrrolidine ring, piperidine ring, piperazine ring, imidazolidine ring and thiazoline ring.

In the general formula (A), the aliphatic hydrocarbon group represented by R ² and the aryl group represent the same groups as the aliphatic hydrocarbon group represented by R ¹ and the aryl group.

In addition, when R ² in the general formula (A) represents —C (═O) Z, the aliphatic hydrocarbon group, aryl group, heterocyclic group represented by Z, and Z represents —NZ ^1. In the case of representing Z ² or —OZ ³ , the aliphatic hydrocarbon group represented by Z ¹ , Z ² and Z ³ , and the aryl group also represents the aliphatic hydrocarbon group represented by R ¹ , hetero It represents a group having the same meaning as a cyclic group and an aryl group.

Below, the preferable example represented by general formula (A) is represented.
The group represented by R ¹ in the general formula (A) preferably represents a hydrogen atom. As the R ² in the general formula (A), a hydrogen atom or, preferably represent a -C (= O) Z, and more preferably represents a hydrogen atom. Furthermore, when R ² represents —C (═O) Z, Z preferably represents an aryl group, a heterocyclic group, —NZ ¹ Z ² , or —OZ ^3, and represents —NZ ¹ Z ² . Most preferred.

In the case where R ² in the general formula (A) is a substituent other than a hydrogen atom, these substituents preferably further have a substituent. Preferred substituents include a hydroxyl group, amino Group, ether group, amide group, sulfonamide group, sulfonimide group, carboxy group, sulfo group, quaternary ammonium group, imidazolium group, phospho group and the like. More preferred substituents are hydroxyl group, amino group , An ether group, a carboxy group, a sulfo group, and a quaternary ammonium group, and most preferably a hydroxyl group.

Specific examples of the compound represented by the general formula (A) of the present invention are given below, but the present invention is not limited thereto.
The polishing composition of the present invention contains (a) a compound represented by the following general formula (A). The compound represented by the following general formula (A) is a nitrogen-containing heterocyclic compound, a compound having 4 or more nitrogen atoms in the molecule, and a carbon atom and NH group constituting the ring are directly bonded. ing.

The alkyl group represented by R ¹ may be linear, branched or cyclic, and more preferably linear.
Moreover, C1-C7 is preferable, as for an alkyl group, 1-6 are more preferable, and 1-3 are still more preferable.
Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group, and a methyl group, an ethyl group, a propyl group, and a butyl group. A hexyl group is more preferable, and a methyl group, an ethyl group, a propyl group, and a hexyl group are more preferable.

The aryl group represented by R ¹ may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. As an aryl group, C6-C12 is preferable.
Specific examples include a phenyl group and a naphthyl group, and a phenyl group is more preferable.

The alkoxy group represented by R ^1, preferably 1 to 7 carbon atoms, more preferably 1 to 6, 1 to 3 is more preferable.

When R ¹ is a substituent other than a hydrogen atom, these substituents may further have a substituent. Examples of the substituent that can be introduced include an alkyl group, a phenyl group, a hydroxy group, a carboxy group, a sulfo group, a carbamoyl group, an amide group, an amino group, and an alkoxy group.

The alkyl group represented by R ² may be linear, branched or cyclic, and is preferably linear or branched.
Moreover, C1-C8 is preferable, as for an alkyl group, 1-6 are more preferable, and 1-3 are still more preferable.
Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group, and a methyl group, an ethyl group, a propyl group, and a butyl group. A hexyl group is more preferable, and a methyl group, an ethyl group, a propyl group, and a hexyl group are more preferable.

The aryl group represented by R ² may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. As an aryl group, C6-C12 is preferable.
Specific examples include a phenyl group and a naphthyl group, and a phenyl group is more preferable.

  Specific examples of the compound represented by the general formula (A) include those shown below.

  Of these, 5-amino-H-tetrazole, A-4, A-14, A-15, A-16, and A-18 are preferable, and 5-amino-tetrazole and A-14 are more preferable.

  Only 1 type may be used for the compound represented by the said general formula (A) for polishing composition, and 2 or more types may be used together.

  The addition amount of the compound represented by the general formula (A) is preferably 5 to 500 mg / L, and preferably 10 to 200 mg / L with respect to the total amount of the polishing composition from the viewpoint of polishing rate. Is more preferable, and it is still more preferable that it is 20-150 mg / L.

<(B) Compound represented by general formula (B), general formula (C) or general formula (D)>
The polishing composition of the present invention contains (b) at least one selected from compounds represented by the following general formula (B), general formula (C) and general formula (D). The compounds represented by the following general formula B, general formula C and general formula (D) are nitrogen-containing heterocyclic compounds and are compounds having three or more nitrogen atoms in the molecule.

In general formula (B), general formula (C), and general formula (D), R ³ , R ⁵ , and R ⁸ are each independently a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amino group, Represents a hydroxy group.

The alkyl group represented by R ³ , R ⁵ , and R ⁸ may be linear, branched, or cyclic, and is preferably linear.
Moreover, C1-C8 is preferable, as for an alkyl group, 1-6 are more preferable, and 1-3 are still more preferable.
Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group, and a methyl group, an ethyl group, a propyl group, and a butyl group. A hexyl group is more preferable, and a methyl group, an ethyl group, a propyl group, and a hexyl group are more preferable.

The aryl group represented by R ³ , R ⁵ , and R ⁸ may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. As an aryl group, C6-C12 is preferable.
Specific examples include a phenyl group and a naphthyl group, and a phenyl group is more preferable.

The hetero atom in the heterocyclic group represented by R ³ , R ⁵ and R ⁸ is preferably a nitrogen atom, a sulfur atom or an oxygen atom, more preferably a nitrogen atom or an oxygen atom, still more preferably nitrogen. Is an atom.

  5-10 are preferable, as for the number of members of a heterocyclic ring, 5-8 are more preferable, and 5-6 are still more preferable.

When R ³ , R ⁵ , and R ⁸ are substituents other than a hydrogen atom, these substituents may further have a substituent. Examples of the substituent that can be introduced include an alkyl group, a phenyl group, and the like. A heterocyclic group, a hydroxy group, a carboxy group, a sulfo group, a carbamoyl group, an amide group, an amino group, and an alkoxy group.

In general formula (B), R ⁴ represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxy group, a carboxy group, or a carbamoyl group.

The alkyl group represented by R ⁴ may be linear, branched or cyclic, and is preferably linear.
Moreover, C1-C8 is preferable, as for an alkyl group, 1-6 are more preferable, and 1-3 are still more preferable.
Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group, and a methyl group, an ethyl group, a propyl group, and a butyl group. A hexyl group is more preferable, and a methyl group, an ethyl group, a propyl group, and a hexyl group are more preferable.

The aryl group represented by R ⁴ may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. As an aryl group, C6-C12 is preferable.
Specific examples include a phenyl group and a naphthyl group, and a phenyl group is more preferable.

The hetero atom in the heterocyclic group represented by R ⁴ is preferably a nitrogen atom, a sulfur atom, an oxygen atom, a nitrogen atom, or an oxygen atom, and more preferably a nitrogen atom.

  The number of heterocycles is preferably 5 to 10, more preferably 5 to 8, and still more preferably 5 to 6.

When R ⁴ is a substituent other than a hydrogen atom, these substituents may further have a substituent. Examples of the substituent that can be introduced include an alkyl group, a phenyl group, a heterocyclic group, a hydroxy group, Examples thereof include a carboxy group, a sulfo group, a carbamoyl group, an amide group, an amino group, and an alkoxy group.

In general formula (C) and general formula (D), R ⁶ , R ⁷ , R ⁹ and R ¹⁰ are each independently a hydrogen atom, alkyl group, aryl group, heterocyclic group, alkoxy group, amino group, hydroxy group Represents a group, a carboxy group, or a carbamoyl group.

The alkyl group represented by R ⁶ , R ⁷ , R ⁹ and R ¹⁰ may be linear, branched or cyclic, and is preferably linear or branched.
Moreover, C1-C8 is preferable, as for an alkyl group, 1-6 are more preferable, and 1-3 are still more preferable.
Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group, and a methyl group, an ethyl group, a propyl group, and a butyl group. A hexyl group is more preferable, and a methyl group, an ethyl group, a propyl group, and a hexyl group are more preferable.

The aryl group represented by R ⁶ , R ⁷ , R ⁹ and R ¹⁰ may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. As an aryl group, C6-C12 is preferable.
Specific examples include a phenyl group and a naphthyl group, and a phenyl group is more preferable.

The hetero atom in the heterocyclic group represented by R ⁶ , R ⁷ , R ⁹ and R ¹⁰ is preferably a nitrogen atom, sulfur atom, oxygen atom, nitrogen atom or oxygen atom, more preferably a nitrogen atom. .

  The number of heterocycles is preferably 5 to 10, more preferably 5 to 8, and still more preferably 5 to 6.

The alkoxy group represented by R ⁶ , R ⁷ , R ⁹ and R ¹⁰ has preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 to 3 carbon atoms.

When R ⁶ , R ⁷ , R ⁹ , and R ¹⁰ are substituents other than a hydrogen atom, these substituents may further have a substituent. Examples of the substituent that can be introduced include an alkyl group, Examples thereof include a phenyl group, a heterocyclic group, a hydroxy group, a carboxy group, a sulfo group, a carbamoyl group, an amide group, an amino group, and an alkoxy group.

R ³ and R ^{4 in} the general formula (B), R ⁵ and R ⁶ in the general formula (C), R ⁶ and R ⁷ and R ⁸ and R ⁹ in the general formula (D), R ⁸ and R ¹⁰ , R ⁹ and R ¹⁰ may be bonded to each other to form a ring.

Specific examples of the compound represented by the general formula (B) include those shown below.
5-Methanol-H-tetrazole 5- (1-ethanol) -H-tetrazole 5- (2-ethanol) -H-tetrazole 5- (3-propan-1-ol) -H-tetrazole 5- (1-propane-2) -Ol) -H-tetrazole 5- (2-propan-2-ol) -H-tetrazole 5- (1-butan-1-ol) -H-tetrazole 5- (1-hexane-1-ol) -H-tetrazole 5 -(1-Cyclohexanol) -H-tetrazole 5- (4-methyl-2-pentan-2-ol) -H-tetrazole 5-methoxymethyl-H-tetrazole 5-acetyl-H-tetrazole 5-benzylsulfonyl-H- Tetrazole 5-dihydroxymethyl-H-tetrazole

1-aminoethyl-tetrazole 1-methanol-tetrazole 1-ethanol-tetrazole 1-amino-5-n-propyl-tetrazole 1- (3-aminopropyl) -tetrazole 1-methyl-tetrazole 1-acetic acid-tetrazole 1-amino -Tetrazole 1-amino-5-methyl-tetrazole

1-H-tetrazole 1-H-tetrazol-5-acetic acid 1-H-tetrazole-5-carboxylic acid 1-H-tetrazole-5-propionic acid 1-H-tetrazole-5-sulfonic acid 1-H-tetrazole- 5-ol 1-H-tetrazole-5-carboxamide 1-H-tetrazole-5-carboxamic acid

5-methyl-H-tetrazole 5-ethyl-H-tetrazole 5-n-propyl-H-tetrazole 5-isopropyl-H-tetrazole 5-n-butyl-H-tetrazole 5-t-butyl-H-tetrazole 5- n-pentyl-H-tetrazole 5-n-hexyl-H-tetrazole 5-phenyl-H-tetrazole 5-aminomethyl-H-tetrazole 5-aminoethyl-H-tetrazole 5- (3-aminopropyl) -H- Tetrazole

Of these, 5-methyl-tetrazole, 5-ethyl-tetrazole, 5-phenyl-H-tetrazole, and 1-H-tetrazole are preferable.
These compounds represented by general formula (B) may be used alone or in combination of two or more in the polishing composition.

  Specific examples of the compound represented by the general formula (C) include those shown below.

1,2,3-triazole,
1,2-Triazole-4-carboxylic acid 5-methyl-1,2,3-triazole-4-carboxylic acid 1- (3-aminopropyl) -1,2,3-triazole 1-aminoethyl-1 , 2,3-Triazole
1-hydroxymethyl-1,2,3-triazole
1-hydroxyethyl-1,2,3-triazole
1-carboxymethyl-1,2,3-triazole 1,2,3-triazole-4,5-dicarboxylic acid 1-amino-1,2,3-triazole,
1-amino-5-methyl-1,2,3-triazole,
1-amino-5-n-propyl-1,2,3-triazole,
1- (β-aminoethyl) -1,2,3-triazole,
1-methyl-1,2,3-triazole,
4- (2-hydroxyethylcarbamoyl) -1,2,3-triazole,
4-aminomethyl-1,2,3-triazole,
4-hydroxymethyl-1,2,3-triazole,
4-hexyl, 1,2,3-triazole,
4,5-dimethyl-1,2,3-triazole,

Among them, 1,2,3-triazole, 4-hexyl, 1,2,3-triazole,
Is more preferable, and 1,2,3-triazole is more preferable.

  These compounds represented by the general formula (C) may be used alone or in combination of two or more in the polishing composition.

  Specific examples of the compound represented by the general formula (D) include those shown below.

1,2,4-triazole,
1,2,4-triazole-3-carboxylic acid 1-methyl-1,2,4-triazole
1- (3-aminopropyl) -1,2,4-triazole 1-aminoethyl-1,2,4-triazole
1-hydroxymethyl-1,2,4-triazole
1-hydroxyethyl-1,2,4-triazole 1,2,4-triazole-1-acetic acid 1,2,4-triazole-3,5-dicarboxylic acid 3-amino-1,2,4-triazole 3-hydroxy Methyl-1,2,4-triazole 3-hydroxyethyl-1,2,4-triazole 3,5-dimethyl-1,2,4-triazole,
5-methyl-1,2,4-triazole-3-carboxylic acid

  Of these, 1,2,4-triazole and 3-amino-1,2,4-triazole are more preferable, and 1,2,4-triazole is more preferable.

  These compounds represented by the general formula (D) may be used alone or in combination of two or more in the polishing composition.

  The total addition amount of the compounds represented by the general formula (B), the general formula (C) and the general formula (D) is 1 to 500 mg / L with respect to the total amount of the polishing composition from the viewpoint of polishing rate. Preferably, it is 5 to 200 mg / L, more preferably 10 to 150 mg / L.

  The total addition amount of the compound represented by (b) general formula (B), general formula (C), and general formula (D) in polishing composition is (a) of the compound represented by general formula (A). It is preferable that it is 10-100 mass% with respect to the addition amount, and it is more preferable that it is 20-60 mass%.

In addition, the above-described component (a) [compound represented by general formula (A)] and (b) component [at least one selected from compounds represented by general formulas (B), (C) and (D) ] Is a compound represented by General Formula (A) and a compound represented by General Formula (B) or General Formula (C).
Moreover, when using 2 or more types together about (b) component, the compound represented by general formula (A) and the compound represented by general formula (B) + general formula (C) is a preferable combination. In this case, the ratio of the compound represented by the general formula (B) / the compound represented by the general formula (C) is preferably 10 to 200, and more preferably 20 to 100.

<(C) Oxidizing agent>
The polishing composition of the present invention contains a compound (oxidant) that can oxidize a metal that is a suitable polishing target.
Examples of the oxidizing agent include hydrogen peroxide, peroxide, nitrate, iodate, periodate, hypochlorite, chlorite, chlorate, perchlorate, peroxodisulfate , Dichromate, permanganate, ozone water and silver (II) salt, iron (III) salt.
Examples of iron (III) salts include inorganic iron (III) salts such as iron nitrate (III), iron chloride (III), iron sulfate (III), iron bromide (III), and organic iron (III) salts. Complex salts are preferably used.

  When an organic complex salt of iron (III) is used, examples of the complex-forming compound constituting the iron (III) complex salt include acetic acid, citric acid, oxalic acid, salicylic acid, diethyldithiocarbamic acid, succinic acid, tartaric acid, glycolic acid, glycine , Alanine, aspartic acid, thioglycolic acid, ethylenediamine, trimethylenediamine, diethylene glycol, triethylene glycol, 1,2-ethanedithiol, malonic acid, glutaric acid, 3-hydroxybutyric acid, propionic acid, phthalic acid, isophthalic acid, 3 Aminopolycarboxylic acid and its salt are mentioned other than -hydroxy salicylic acid, 3,5-dihydroxy salicylic acid, gallic acid, benzoic acid, maleic acid, etc. and these salts.

  Examples of aminopolycarboxylic acids and salts thereof include ethylenediamine-N, N, N ′, N′-tetraacetic acid, diethylenetriaminepentaacetic acid, 1,3-diaminopropane-N, N, N ′, N′-tetraacetic acid, , 2-Diaminopropane-N, N, N ′, N′-tetraacetic acid, ethylenediamine-N, N′-disuccinic acid (racemic), ethylenediamine disuccinic acid (SS), N- (2-carboxylate ethyl) ) -L-aspartic acid, N- (carboxymethyl) -L-aspartic acid, β-alanine diacetic acid, methyliminodiacetic acid, nitrilotriacetic acid, cyclohexanediaminetetraacetic acid, iminodiacetic acid, glycol etherdiaminetetraacetic acid, ethylenediamine 1-N, N'-diacetic acid, ethylenediamine orthohydroxyphenylacetic acid, N, N-bis (2-hydroxybenzidine ) Ethylenediamine -N, it includes and salts thereof such as N- diacetic acid. The kind of the counter salt is preferably an alkali metal salt or an ammonium salt, and particularly preferably an ammonium salt.

  Among them, hydrogen peroxide, iodate, hypochlorite, chlorate, persulfate, and organic complex salts of iron (III) are preferable, and preferable complex-forming compounds when using an organic complex salt of iron (III) are Citric acid, tartaric acid, aminopolycarboxylic acid (specifically, ethylenediamine-N, N, N ′, N′-tetraacetic acid, diethylenetriaminepentaacetic acid, 1,3-diaminopropane-N, N, N ′, N '-Tetraacetic acid, ethylenediamine-N, N'-disuccinic acid (racemic), ethylenediaminedisuccinic acid (SS), N- (2-carboxylateethyl) -L-aspartic acid, N- (carboxymethyl)- L-aspartic acid, β-alanine diacetic acid, methyliminodiacetic acid, nitrilotriacetic acid, iminodiacetic acid).

  Among the oxidizing agents, hydrogen peroxide, persulfate, and iron (III) ethylenediamine-N, N, N ′, N′-tetraacetic acid, 1,3-diaminopropane-N, N, N ′, N′— Most preferred is a complex of tetraacetic acid and ethylenediamine disuccinic acid (SS form).

  (C) The addition amount of the oxidizing agent is preferably 0.003 mol to 8 mol, more preferably 0.03 mol to 6 mol, and more preferably 0.1 mol per liter of the polishing composition when used for polishing. It is especially preferable to set it as -4 mol. That is, the addition amount of the oxidizing agent is preferably 0.003 mol or more from the viewpoint of sufficient metal oxidation and ensuring a high CMP rate, and is preferably 8 mol or less from the viewpoint of preventing roughening of the polished surface.

  The polishing composition of the present invention may contain the following components as necessary in addition to the above-described components. Hereinafter, optional components applicable to the polishing composition of the present invention will be described.

<(D) Abrasive grain>
The polishing composition of the present invention preferably contains abrasive grains. Preferable abrasive grains include, for example, silica (precipitated silica, fumed silica, colloidal silica, synthetic silica), ceria, alumina, titania, zirconia, germania, manganese oxide, and colloidal silica is particularly preferable.
As a method for producing colloidal silica particles which can be preferably used as abrasive grains, for example, Si (OC ₂ H ₅ ) ₄ , Si (sec-OC ₄ H ₉ ) ₄ , Si (OCH ₃ ) ₄ , Si (OC ₄ H ₉ ) ₄ The preparation method which hydrolyzes the silicon alkoxide compound like this by the sol-gel method is mentioned. The colloidal particles thus obtained have a very sharp particle size distribution.

  The primary particle size of the abrasive grains is a particle size cumulative curve showing the relationship between the particle size of the abrasive grains and the cumulative frequency obtained by integrating the number of particles having the particle size, and the cumulative frequency of this curve is the point at which the cumulative frequency is 50%. It means the particle diameter. For example, LB-500 manufactured by HORIBA, Ltd. is used as a measuring device for obtaining the particle size distribution.

  When the abrasive grains are spherical, the values measured as they are can be adopted. However, the particle size of the amorphous particles is expressed by the diameter of a sphere that is equal to the particle volume. The particle size can be measured by various known methods such as photon correlation method, laser diffraction method, Coulter counter method, etc. In the present invention, observation with a scanning microscope or transmission electron micrograph with a replica method is possible. Is used to obtain and calculate the shape and size of each particle.

  Specifically, the particle thickness is obtained from the projected area of the particle and the shadow of the replica with reference to a diffraction grating of a known length, and the volume of each particle is calculated from these. In this case, although it depends on the particle size distribution, it is desirable to measure and statistically measure 500 or more particles. This method is described in detail in paragraph No. [0024] of JP-A-2001-75222, and the description can be applied to the present invention.

  The average particle size (primary particle size) of the abrasive grains contained in the polishing composition of the present invention is preferably in the range of 20 to 70 nm, more preferably 20 to 50 nm. Particles of 5 nm or more are preferable for the purpose of achieving a sufficient polishing speed. Further, the particle diameter is preferably 50 nm or less for the purpose of not generating excessive frictional heat during polishing.

  In addition, not only the general inorganic abrasive grains as described above but also organic polymer particles can be used in combination as long as the effects of the present invention are not impaired. In addition, colloidal silica surface-modified with aluminate ions or borate ions, colloidal silica with controlled surface potential, colloidal silica with various surface treatments, composite abrasive grains made of multiple materials, etc. It is also possible to use it accordingly.

  The amount of (d) abrasive grains added in the present invention is appropriately selected according to the purpose, but in general, it can be used in the range of 0.001 to 20% by mass with respect to the total mass of the metal polishing composition. However, in the present invention, due to the effects of the addition of the components (a) and (b), excellent polishing characteristics can be exhibited even when the amount of abrasive grains added is less than 1.0% by mass. From the viewpoint of suppressing scratches and the like, the amount of abrasive grains added is preferably less than 1.0% by mass, and more preferably in the range of 0.01 to 0.6% by mass.

<(E) At least one selected from surfactants and water-soluble polymer compounds>
The polishing composition of the present invention can contain (e) at least one selected from a surfactant and a water-soluble polymer compound.
As the surfactant and / or the water-soluble polymer compound, the acid form is desirable, and when taking a salt structure, ammonium salt, potassium salt, sodium salt and the like can be mentioned, and ammonium salt and potassium salt are particularly preferable.

  Each of the surfactant and / or the water-soluble polymer compound has an action of reducing the contact angle with respect to the surface to be polished, and has an action of promoting uniform polishing. As the surfactant and / or water-soluble polymer compound to be used, those selected from the following group are suitable.

  Examples of the anionic surfactant include carboxylate, sulfonate, sulfate ester salt and phosphate ester salt. As the carboxylate salt, soap, N-acyl amino acid salt, polyoxyethylene or polyoxypropylene alkyl ether carboxyl Acid salt, acylated peptide; as sulfonate, alkyl sulfonate, alkyl benzene and alkyl naphthalene sulfonate, naphthalene sulfonate, (alkyl) naphthalene sulfonic acid formalin condensate, (alkyl) naphthalene sulfonic acid formalin condensate, Sulfosuccinate, α-olefin sulfonate, N-acyl sulfonate; sulfate ester, sulfated oil, alkyl sulfate, alkyl ether sulfate, polyoxyethylene or polyoxypropylene alkyl allyl ether sulfate , Alkylamide sulfates; as phosphoric acid ester salts, alkyl phosphate salts, may be mentioned polyoxyethylene or polyoxypropylene alkyl allyl ether phosphates.

  As cationic surfactant, aliphatic amine salt, aliphatic quaternary ammonium salt, benzalkonium chloride salt, benzethonium chloride, pyridinium salt, imidazolinium salt; as amphoteric surfactant, carboxybetaine type, sulfobetaine type, Mention may be made of aminocarboxylates, imidazolinium betaines, lecithins, alkylamine oxides.

Nonionic surfactants include ether type, ether ester type, ester type and nitrogen-containing type. Ether type includes polyoxyethylene alkyl and alkylphenyl ether, alkylallyl formaldehyde condensed polyoxyethylene ether, polyoxyethylene poly Examples include oxypropylene block polymer, polyoxyethylene polyoxypropylene alkyl ether, ether ester type, glycerin ester polyoxyethylene ether, sorbitan ester polyoxyethylene ether, sorbitol ester polyoxyethylene ether, ester type, Polyethylene glycol fatty acid ester, glycerin ester, polyglycerin ester, sorbitan ester, propylene glycol ester Le, sucrose esters, nitrogen-containing type, fatty acid alkanolamides, polyoxyethylene fatty acid amides, polyoxyethylene alkyl amide, and the like.
In addition, fluorine surfactants, silicone surfactants, and the like can be given.

  Of these, surfactants having at least one sulfo group and phenyl group such as dodecylbenzenesulfonic acid and alkyldiphenyl ether monosulfonic acid are preferable.

  Examples of water-soluble polymer compounds include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol alkyl ether, polyethylene glycol alkenyl ether, alkyl polyethylene glycol, alkyl polyethylene glycol alkyl ether, alkyl polyethylene glycol alkenyl ether, alkenyl polyethylene glycol, alkenyl. Polyethylene glycol alkyl ether, alkenyl polyethylene glycol alkenyl ether, polypropylene glycol alkyl ether, polypropylene glycol alkenyl ether, alkyl polypropylene glycol, alkyl polypropylene glycol alkyl ether, alkyl polypropylene glycol Alkeni Ethers, ethers such as alkenyl polypropylene glycol, alkenyl polypropylene glycol alkyl ether and alkenyl polypropylene glycol alkenyl ether; polysaccharides such as alginic acid, pectic acid, carboxymethylcellulose, curdlan and pullulan; amino acid salts; polyaspartic acid, polyglutamic acid, polylysine, Polymalic acid, polymethacrylic acid, polymethacrylic acid ammonium salt, polymethacrylic acid sodium salt, polymaleic acid, polyitaconic acid, polyfumaric acid, poly (p-styrenecarboxylic acid), polyacrylic acid, polyacrylamide, aminopolyacrylamide, polyacrylic Acid ammonium salt, polyacrylic acid sodium salt, polyamic acid, polyamic acid ammonium salt, polyamic acid sodium salt Polycarboxylic acids and their salts such as ium salt and polyglyoxylic acid; polyvinyl alcohol, vinyl polymers such as polyvinyl pyrrolidone and acrolein and the like.

However, when the substrate to be applied is a silicon substrate for a semiconductor integrated circuit or the like, contamination with alkali metal, alkaline earth metal, halide, etc. is not desirable. In the case of taking a structure, an ammonium salt is desirable. This is not the case when the substrate is a glass substrate or the like.
Among these, water-soluble polymer compounds include polyamic acid, polyamic acid ammonium salt, polyamic acid sodium salt, polyvinyl pyrrolidone, polyacrylamide, polyurea,
A water-soluble polymer compound having an amide bond such as polyurethane is preferred.

The addition amount of the surfactant and / or the water-soluble polymer compound is preferably 0.0001 to 0.1 g in 1 L of the polishing composition when used for polishing as a total amount, 0.0005 to 0.05 g is more preferable, and 0.001 to 0.01 g is particularly preferable. That is, the addition amount of the surfactant and / or the water-soluble polymer compound is preferably 0.001 g or more for obtaining a sufficient effect, and is preferably 10 g or less from the viewpoint of preventing the CMP rate from being lowered.
Moreover, as a weight average molecular weight of these surfactant and / or water-soluble polymer compound, 500-100000 are preferable, and 2000-50000 are especially preferable.

  Only one surfactant may be used, or two or more surfactants may be used in combination. The water-soluble polymer compound may also be used alone or in combination of two or more.

<Organic acid>
The metal polishing composition of the present invention preferably contains an organic acid. The organic acid here is a compound having a structure different from that of an oxidizing agent for oxidizing a metal, and does not include an acid that functions as the above-described oxidizing agent. The acid here has an action of promoting oxidation, adjusting pH, and buffering agent.
An organic acid is an organic compound that generates an acid, and preferably has at least one carboxyl group. The organic acid is desirably water-soluble, and more preferably amino acids.

Examples of the organic acid include those described in JP-A-2007-129167, and specifically, those selected from the following group are more suitable.
That is, amino acids, 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, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalate Examples include acids, malic acid, tartaric acid, citric acid, lactic acid, and ammonium salts and alkali metal salts thereof.

The amino acids (including primary, secondary, tertiary amino acids, and aminopolycarboxylic acids) are preferably water-soluble. Those selected from the following group are more suitable.
Glycine, L-alanine, β-alanine, L-2-aminobutyric acid, L-norvaline, L-valine, L-leucine, L-norleucine, L-isoleucine, L-alloisoleucine, L-phenylalanine, L-proline, Sarcosine, L-ornithine, L-lysine, taurine, L-serine, L-threonine, L-allothreonine, L-homoserine, L-tyrosine, 3,5-diiodo-L-tyrosine, β- (3,4- Dihydroxyphenyl) -L-alanine, L-thyroxine, 4-hydroxy-L-proline, L-cystine, L-methionine, L-ethionine, L-lanthionine, L-cystathionine, L-cystine, L-cystine acid, L Aspartic acid, L-glutamic acid, S- (carboxymethyl) -L-cysteine, 4-aminobutyric acid, L Asparagine, L-glutamine, azaserine, L-arginine, L-canavanine, L-citrulline, δ-hydroxy-L-lysine, creatine, L-quinurenin, L-histidine, 1-methyl-L-histidine, 3-methyl -L-histidine, ergothioneine, L-tryptophan, hydroxyethyliminodiacetic acid, dihydroxyethylglycine, N-hydroxyethylglycine, N-hydroxyethyl-α-alanine, actinomycin C1, apamin, angiotensin I, angiotensin II and antipine Etc.
In particular, malic acid, tartaric acid, citric acid, glycine, glycolic acid, and hydroxyethyliminodiacetic acid are preferable in that the etching rate can be effectively suppressed while maintaining a practical CMP rate.

  The addition amount of the organic acid is preferably 0.0005 to 0.5 mol and preferably 0.005 to 0.3 mol in 1 L of the metal polishing composition (use liquid) when used for polishing. More preferably, 0.01 mol to 0.1 mol is particularly preferable. That is, the amount of acid added is preferably 0.5 mol or less from the viewpoint of suppressing etching, and 0.0005 mol or more is preferable for obtaining a sufficient effect.

<Phosphate or phosphite>
The polishing composition of the present invention preferably contains a phosphate or phosphite when it contains inorganic components other than abrasive grains.

<PH of polishing composition>
In the polishing composition of the present invention, due to the reactivity and adsorptivity to the polishing surface, the solubility of the polishing metal, the electrochemical properties of the surface to be polished, the dissociation state of the compound functional group, the stability as a liquid, etc. It is preferable to appropriately set the kind of component, the amount added, or the pH.
The pH of the polishing composition of the present invention is preferably from 3 to 9, more preferably from 3.8 to 8.0, from the viewpoint of planarization performance. The pH can be easily adjusted by appropriately selecting and adding a buffer, an alkali agent, an inorganic acid, and the like.

[Raw metal materials]
In the present invention, the semiconductor to be polished is preferably an LSI having wiring made of copper metal and / or copper alloy, and particularly preferably a copper alloy. Furthermore, the copper alloy containing silver is preferable among copper alloys. The silver content contained in the copper alloy is preferably 40% by mass or less, particularly 10% by mass or less, more preferably 1% by mass or less, and most preferably in the range of 0.00001 to 0.1% by mass. Exhibits excellent effects.

[Wiring thickness]
In the present invention, the semiconductor to be polished is, for example, a DRAM device system having a half pitch of 0.15 μm or less, particularly 0.10 μm or less, more preferably 0.08 μm or less, while MPU device system is 0.12 μm or less. In particular, an LSI having a wiring of 0.09 μm or less, more preferably 0.07 μm or less is preferable. The polishing liquid of the present invention exhibits particularly excellent effects on these LSIs.

[Barrier metal]
In the present invention, it is preferable to provide a barrier layer for preventing the diffusion of copper between the wiring in which the semiconductor is made of copper metal and / or a copper alloy and the interlayer insulating film. As the barrier layer, a low-resistance metal material is preferable, and TiN, TiW, Ta, TaN, W, WN, and Ru are particularly preferable, and Ta, TaN, Ti, TiN, and TiW are particularly preferable.

[Polishing method]
The polishing composition of the present invention is a concentrated liquid, and when used, it is diluted with water to make a working liquid, or each component is mixed in the form of an aqueous solution described in the next section, and if necessary, In some cases, it is diluted with water to make a working solution, or it may be prepared as a working solution.
The polishing method using the polishing composition of the present invention can be applied to any case, and the polishing composition is supplied to a polishing pad on a polishing surface plate and brought into contact with the surface to be polished to polish the surface to be polished. In this polishing method, polishing is performed by relatively moving the pad.
As an apparatus for polishing, there is a general polishing apparatus having a polishing surface plate with a holder for holding a semiconductor substrate having a surface to be polished and a polishing pad attached (a motor etc. capable of changing the number of rotations is attached). Can be used.
As the polishing pad, a general nonwoven fabric, foamed polyurethane, porous fluororesin, or the like can be used, and there is no particular limitation.
The polishing conditions are not limited, but the rotation speed of the polishing surface plate is preferably a low rotation of 200 rpm or less so that the substrate does not jump out.
The pressure applied to the polishing pad of the semiconductor substrate having the surface to be polished (film to be polished) is preferably 20 kPa or less. In order to satisfy the uniformity of the polishing rate within the wafer surface and the flatness of the pattern, 6 More preferably, it is ˜15 kPa.

During polishing, the polishing composition is continuously supplied to the polishing pad with a pump or the like. Although the supply amount is not limited, it is preferable that the surface of the polishing pad is always covered with the polishing composition.
After the polishing, the semiconductor substrate is thoroughly washed in running water, and then dried after removing water droplets adhering to the semiconductor substrate using a spin dryer or the like. When the polishing composition of the present invention is used, polishing is performed. The subsequent detergency becomes good. This is presumed to be due to electrostatic repulsion between the abrasive grains and the wiring metal.
In the polishing method of the present invention, the aqueous solution to be diluted is the same as the aqueous solution described below.
The aqueous solution is water containing at least one of an oxidizing agent, an acid, an additive, and a surfactant in advance, and a component obtained by adding up the components contained in the aqueous solution and the components of the polishing composition to be diluted is polished. It becomes a component at the time of grind | polishing using the composition for water.
When diluted with an aqueous solution and used, components that are difficult to dissolve can be blended in the form of an aqueous solution, and a more concentrated polishing composition can be prepared.

As a method of diluting the concentrated polishing composition by adding water, the pipe for supplying the concentrated polishing composition and the pipe for supplying the water are mixed together and mixed, mixed and diluted for polishing. There is a method of supplying a composition to a polishing pad.
Mixing is a method in which liquids collide with each other through a narrow passage under pressure, a method in which a filling such as a glass tube is filled in the pipe, and the flow of liquid is repeatedly separated and merged. Conventional methods such as a method of providing blades that rotate in the above can be employed.

  The supply rate of the polishing composition can be appropriately selected within the range of 10 to 1000 ml / min. However, in consideration of the physical properties of the polishing composition of the present invention, it is preferably 190 ml / min or less, and preferably 100 to 190 ml / min. A range of min is more preferable.

As a method of diluting and polishing the concentrated polishing composition with an aqueous solution or the like, a pipe for supplying the polishing composition and a pipe for supplying water or an aqueous solution are independently provided, and a predetermined amount of liquid is supplied from each of them. And polishing while mixing by the relative movement of the polishing pad and the surface to be polished.
Alternatively, there is a method in which a predetermined amount of a concentrated polishing composition and water are mixed in one container and then mixed, and then the mixed polishing composition is supplied to a polishing pad for polishing.

In another polishing method of the present invention, the component to be contained in the polishing composition is divided into at least two components, and when these components are used, they are diluted by adding water and supplied to the polishing pad on the polishing platen. In this method, the surface to be polished and the polishing pad are moved relative to each other and brought into contact with the surface to be polished.
For example, an oxidant is one component (A), an acid, an additive, a surfactant, and water are one component (B), and when they are used, the component (A) and the component are made with water. Dilute (B) for use.
In addition, the low-solubility additive is divided into two components (A) and (B), and the oxidizing agent, additive and surfactant are one component (A), and the acid, additive, surfactant and Water is used as one component (B), and when these components are used, water is added to dilute the component (A) and the component (B).
In this example, three pipes for supplying the component (A), the component (B), and water are required, and dilution mixing is performed by combining the three pipes into one pipe that supplies the polishing pad. There is a method of mixing in the pipe. In this case, it is also possible to combine the two pipes and then connect the other one pipe.

For example, a component containing an additive that hardly dissolves is mixed with another component, a mixing path is lengthened to ensure a dissolution time, and then a water pipe is further coupled.
Other mixing methods are as described above, in which the three pipes are each guided directly to the polishing pad and mixed by the relative movement of the polishing pad and the surface to be polished, and the three components are mixed in one container. The diluted polishing composition is supplied to the polishing pad.

  In the above polishing method, one constituent component containing an oxidizing agent is made 40 ° C. or lower, the other constituent components are heated in the range of room temperature to 100 ° C., and one constituent component and another constituent component or water are added. When diluting and using, it can also be made 40 degrees C or less after mixing. Since solubility becomes high when temperature is high, it is a preferable method for increasing the solubility of raw materials with low solubility of the polishing composition.

A raw material in which other components not containing an oxidant are heated and dissolved in the range of room temperature to 100 ° C. is precipitated in the solution when the temperature is lowered. It is necessary to dissolve what is deposited by heating. For this, a means for feeding a heated component solution and a means for stirring the liquid containing the precipitate, feeding the liquid, and heating and dissolving the pipe can be employed.
When the temperature of one component containing an oxidant is increased to 40 ° C. or higher, the oxidant may be decomposed. Therefore, the heated component and the oxidation for cooling the heated component When mixed with one component containing an agent, the temperature is set to 40 ° C. or lower.

  In the present invention, as described above, the components of the polishing composition may be divided into two or more parts and supplied to the polishing surface. In this case, it is preferable to divide and supply the component containing an oxide and the component containing an acid. Further, the polishing composition may be used as a concentrated liquid and supplied to the polishing surface separately from the dilution water.

〔pad〕
The polishing pad may be a non-foamed structure pad or a foamed structure pad. The former uses a hard synthetic resin bulk material like a plastic plate for a pad.
Further, the latter further includes three types of a closed foam (dry foam system), a continuous foam (wet foam system), and a two-layer composite (laminated system), and a two-layer composite (laminated system) is particularly preferable. Foaming may be uniform or non-uniform.
Further, it may contain abrasive grains (for example, ceria, silica, alumina, resin, etc.) used for polishing. In addition, the hardness may be either soft or hard, and either may be used. In the laminated system, it is preferable to use a different hardness for each layer.
The material is preferably non-woven fabric, artificial leather, polyamide, polyurethane, polyester, polycarbonate or the like.
Further, the surface that contacts the polished surface may be subjected to processing such as lattice grooves / holes / concentric grooves / helical grooves.

[Wafer]
The target wafer to be subjected to CMP with the polishing composition of the present invention preferably has a diameter of 200 mm or more, particularly preferably 300 mm or more. The effect of the present invention is remarkably exhibited when the thickness is 300 mm or more.

  Hereinafter, the present invention will be described by way of examples. The present invention is not limited to these examples.

Example 1
-Polishing composition-
(A) Compound represented by general formula (A) [a-1]: amount described in Table 2 (b) Compound represented by general formula (B) [b-1]: described in Table 3 (D) Abrasive grain [PL-3H, manufactured by Fuso Chemical Co., Ltd.] (primary particle size 35 nm) 0.5 mass%
・ (C) Oxidizing agent (30% hydrogen peroxide) 20ml / L
・ Glycine 8g / L
・ PH (adjusted to pH 7 by adding ammonia water)

(Examples 2 to 10)
The polishing compositions of Examples 2 to 7 and Example 10 were obtained in the same manner as in Example 1 except that the components (a) and (b) used in Example 1 were changed as shown in Table 1 below. It was. Further, as the component (e), the polishing composition of Example 8 was prepared by adding 10 ppm of the anionic surfactant dodecylbenzenesulfonic acid (described as “DBS” in Table 1) to the polishing composition of Example 1. did. Further, as the component (e), polishing of Example 9 in which 200 ppm of polyvinylpyrrolidone (15K) (described as “PVP” in Table 1), which is a water-soluble polymer compound, was added to the polishing composition of Example 1. A composition was prepared.

(Comparative Example 1)
A polishing composition of Comparative Example 1 was obtained in the same manner as in Example 1 except that the component (b) was not added.
(Comparative Example 2)
A polishing composition of Comparative Example 2 was obtained in the same manner as in Example 2, except that the component (b) was not added.
(Comparative Example 3)
A polishing composition of Comparative Example 3 was obtained in the same manner as in Example 3, except that the component (b) was not added.
(Comparative Example 4)
A polishing composition of Comparative Example 4 was obtained in the same manner as in Example 1 except that the component (a) was not added.

  After the polishing compositions (polishing liquids) prepared in Examples 1 to 10 and Comparative Examples 1 to 4 were prepared and stored at room temperature for 6 months, polishing was performed by the following polishing method, and polishing performance (polishing speed, polishing rate, Dishing, copper / titanium selectivity). The evaluation results are shown in Table 1.

<Polishing rate evaluation>
An apparatus “FREX-300” manufactured by Ebara Corporation was used as a polishing apparatus, and the film provided on each wafer was polished while supplying slurry under the following conditions, and the polishing rate at that time was calculated.
Wafer: Silicon wafer with 12 inch copper film
Silicon wafer with 12 inch titanium film Table rotation speed: 104 rpm
Head rotation speed: 105rpm
(Processing linear velocity = 1.0 m / s)
Polishing pressure: 105 hPa
Polishing pad: IC-1400 (K) manufactured by Rohm and Haas
Slurry supply rate: 190 ml / min Measurement of polishing rate: The film thickness was measured using a four-short needle film thickness meter before and after polishing, and determined using the following formula.
Polishing rate (nm / min) = (thickness of copper film before polishing−thickness of copper film after polishing) / polishing time

<Dishing evaluation>
An apparatus “FREX-300” manufactured by Ebara Manufacturing Co., Ltd. was used as the polishing apparatus, and the film provided on each patterned wafer was polished while supplying slurry under the following conditions, and the level difference at that time was measured.
Base: A silicon oxide film is patterned by a photolithography process and a reactive ion etching process to form a wiring groove and a connection hole having a width of 0.09 to 100 μm and a depth of 600 nm. Further, a thickness of 20 nm is formed by a sputtering method. A Ta film is formed, then a copper film having a thickness of 50 nm is formed by a sputtering method, and then a 12 inch wafer in which a copper film having a total thickness of 1000 nm is formed by a plating method is used.
Head rotation speed: 50 rpm
Polishing pressure: 105 hPa
Polishing pad: Rodel Nitta Co., Ltd. Product No. IC-1400 (K)
Slurry supply rate: 200 ml / min Step difference measurement: Using a stylus type step difference meter, the step difference was measured at L / S of 100 μm / 100 μm.

<Copper / titanium selection ratio>
Measurement of selection ratio: Each polishing rate was determined using a silicon wafer with a copper film and a silicon wafer with a titanium film, and calculated using the following formula.
Selection ratio = polishing rate of copper film / polishing rate of titanium film

  The details of the component compound (a) which is the compound represented by the general formula (A) described in Table 1 are represented by the following general formula (B), (C) or (D) in Table 2 below. Details of component compound (b) are shown in Table 3 below.

As apparent from Table 1, (a) component compound which is a compound represented by general formula (A), (b) component compound represented by general formula (B), (C) or (D), Each of the polishing compositions containing Examples 1 to 10 has a high selectivity of the polishing rate between the barrier layer made of titanium and the conductive metal, while dishing is suppressed while maintaining a sufficient polishing rate. I understood that.
In addition, the polishing compositions of Comparative Examples 1 to 3 that do not contain (b) the component compound and Comparative Example 4 that do not contain the (a) component compound are insufficient in suppressing dishing, and are barrier layers made of titanium. The selectivity of the polishing rate between the metal and the conductive metal was low.

Claims (14)

A metal polishing composition mainly used for chemical mechanical polishing of conductive metal wiring of a semiconductor device, wherein (a) a compound represented by the following general formula (A), (b) the following general formula (B) A metal polishing composition comprising: at least one selected from the following general formula (C) and a compound represented by the following general formula (D); and (c) an oxidizing agent.

In the general formula (A), R ¹ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocycle, an alkoxy group, an amino group, a hydroxy group, a carboxy group, or a carbamoyl group, and R ² represents a hydrogen atom. , An aliphatic hydrocarbon group, an aryl group, or —C (═O) Z, wherein Z is a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, —NZ ¹ Z ² , or — OZ ³ is represented, and Z ¹ , Z ² and Z ³ each independently represent a hydrogen atom, an aliphatic hydrocarbon group or an aryl group.

In general formula (B), general formula (C), and general formula (D), R ³ , R ^5, and R ⁸ are each independently a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amino group, or Represents a hydroxy group, R ⁴ represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxy group, a carboxy group, or a carbamoyl group, and R ⁶ , R ⁷ , R ⁹ , and R ¹⁰ are Each independently represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an amino group, a hydroxy group, a carboxy group, or a carbamoyl group.   The metal polishing composition according to claim 1, further comprising (d) abrasive grains.   The metal polishing composition according to claim 1 or 2, further comprising (e) at least one selected from a surfactant and a water-soluble polymer compound.   (E) at least one selected from a surfactant and a water-soluble polymer compound is a surfactant having at least one sulfo group and a phenyl group, or a water-soluble polymer compound having an amide bond. The metal polishing composition according to claim 3. (A) The compound represented by the general formula (A) is one or more selected from 5-amino-1H-tetrazole and the following compound group. The metal polishing composition according to any one of the above.

  (A) The metal polishing composition according to claim 5, wherein the compound represented by the general formula (A) is 5-amino-1H-tetrazole. The metal polishing composition according to claim 1, wherein R ⁴ in the general formula (B) is a substituent having an alkyl group.   5. At least one selected from (e) a surfactant and a water-soluble polymer compound is alkyl diphenyl ether monosulfonic acid or a salt thereof, or alkyl diphenyl ether disulfonic acid or a salt thereof. The metal polishing composition according to 1.   The metal polishing composition according to any one of claims 1 to 8, wherein the metal polishing composition is used for polishing a conductive metal wiring made of copper.   In a chemical mechanical polishing step of a semiconductor device having a barrier layer containing titanium and a conductive metal wiring, a polishing rate selection ratio between the barrier layer containing titanium and the conductive metal is 200 or more. The metal polishing composition according to any one of claims 1 to 9. A chemical mechanical polishing method for a semiconductor device in which a metal polishing composition is supplied to a polishing pad on a polishing surface plate, and the polishing pad is brought into contact with the surface to be polished of the semiconductor device and moved relative to the polishing pad. a) a compound represented by the following general formula (A), (b) at least one selected from compounds represented by the following general formula (B), the following general formula (C) and the following general formula (D), and (C) A chemical mechanical polishing method comprising polishing using a metal polishing composition containing an oxidizing agent.

In the general formula (A), R ¹ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocycle, an alkoxy group, an amino group, a hydroxy group, a carboxy group, or a carbamoyl group, and R ² represents a hydrogen atom. , An aliphatic hydrocarbon group, an aryl group, or —C (═O) Z, wherein Z is a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, —NZ ¹ Z ² , or — OZ ³ is represented, and Z ¹ , Z ² and Z ³ each independently represent a hydrogen atom, an aliphatic hydrocarbon group or an aryl group.

In general formula (B), general formula (C), and general formula (D), R ³ , R ^5, and R ⁸ are each independently a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amino group, or Represents a hydroxy group, R ⁴ represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxy group, a carboxy group, or a carbamoyl group, and R ⁶ , R ⁷ , R ⁹ , and R ¹⁰ are Each independently represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an amino group, a hydroxy group, a carboxy group, or a carbamoyl group.   The polishing is performed by relatively moving the polishing pad and the surface to be polished of the semiconductor device in a state where the surface to be polished of the semiconductor device is pressed against the polishing pad with a pressure of 20 kpa or less. The chemical mechanical polishing method described.   The chemical mechanical polishing method according to claim 11 or 12, wherein a supply flow rate of the metal polishing composition to the polishing pad is 190 mL / min or less.   In a chemical mechanical polishing step of a semiconductor device having a barrier layer containing titanium and a conductive metal wiring, a polishing rate selection ratio between the barrier layer containing titanium and the conductive metal is 200 or more. A chemical mechanical polishing method comprising polishing using the metal polishing composition according to any one of claims 1 to 10.