TWI512096B - Composition for metal polishing and chemical mechanical polishing method using the same - Google Patents

Description

Metal polishing composition and chemical mechanical polishing method using same

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

In the development of a semiconductor device including a semiconductor integrated circuit (hereinafter referred to as "LSI"), in order to make the semiconductor device highly integrated. The method of increasing the speed and miniaturizing or layering the wiring is a review.

Such a technique employs various techniques such as chemical mechanical polishing (hereinafter referred to as "CMP"). The CMP is used to polish an interlayer insulating film (SiO ₂ or the like) or a metal thin film for wiring to smooth the substrate or to remove the metal thin film remaining when the wiring is formed (for example, refer to the specification of US Pat. No. 4944836).

The general method of CMP is as follows.

The polishing pad is attached to a circular grinding turntable (pressing plate), and the surface of the polishing pad is impregnated with a polishing liquid. The surface of the substrate (wafer) is pressed against the polishing pad, and both the polishing disk and the substrate are rotated in a state where a specified pressure (grinding pressure) is applied from the inside.

The so-called CMP planarizes the surface of the substrate by the mechanical friction generated by the above operation.

As a metal for wiring, tungsten and aluminum have been widely used in interconnect structures in the past. However, attention has been focused on further high performance, and LSIs using copper having a wiring resistance lower than those of metals have been developed. As wiring the copper As a method, a damascene structure method is known (for example, see JP-A-2-278822). Further, the contact hole and the wiring trench are simultaneously formed in the interlayer insulating film, and the double damascene structure system in which the metal is buried in both is widely used. As the target material for the copper wiring, high-purity copper targets of 5N (99.999%) or more have been shipped on the market.

However, in recent years, when the wiring is made finer in accordance with the demand for further higher density, the conductivity or electronic characteristics of the copper wiring are required to be improved. On the other hand, the copper alloy in which the third component was added to high-purity copper was also examined in advance.

Further, high-speed metal polishing means which does not contaminate such high-precision and high-purity materials and can improve productivity can be required. In particular, since copper is a soft metal, in the case of grinding copper and copper alloy, there is a phenomenon in which only the center is ground deep and dish-shaped recessed (concave twist; dishing), or a plurality of wiring metal surface A phenomenon in which a dish-shaped recess is formed (wearing; abrasion) or a scratch (scratch) is likely to occur, and a progressively high-precision grinding technique is required.

In addition, in recent years, wafers have been enlarged due to increased productivity, and wafers having a diameter of 200 mm or more have been widely used, and wafers of 300 mm or more have also been manufactured. With such an increase in the size of the wafer, the difference in the polishing rate between the center portion and the peripheral portion of the wafer tends to be large, and therefore it is strongly required to perform uniform polishing in the plane of the wafer.

On the other hand, a chemical polishing method which is not suitable for a mechanical polishing method for copper and a copper alloy, and a chemical polishing method by a dissolution only has been disclosed (for example, see JP-A-49-122432).

However, since the chemical polishing method is performed by chemical dissolution, the metal film of the convex portion is more likely to be cut into the concave portion, that is, concave, than the CMP which is selectively subjected to chemical mechanical polishing. Problems such as dishing have made the improvement of flatness a problem.

Further, when copper wiring is used for LSI manufacturing, in order to prevent copper ions from diffusing into the insulating material, a diffusion preventing layer called a barrier layer is generally provided between the wiring portion and the insulating layer. 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 may be provided in one layer or two layers.

These barrier materials are inherently electrically conductive, so in order to prevent errors such as leakage, the barrier material on the insulating layer must be completely removed. In the removal processing, the same method as in the case of polishing the entire metal wiring material is also applied. There is also a so-called barrier CMP.

In addition, the overall polishing of copper is likely to cause concave distortion in a particularly wide metal wiring portion, and in order to finally flatten, it is preferable to adjust the amount of polishing and removal of the wiring portion and the barrier portion. For the polishing liquid for barrier polishing, it is preferable to have the most suitable polishing selectivity of copper/barrier metal. Moreover, since the wiring pitch or the wiring density differs in the wiring layers of the respective grades, it is preferable to further appropriately adjust the above-described polishing selectivity.

The polishing composition for metal (the polishing liquid for metal) for CMP generally contains solid abrasive particles (for example, alumina or cerium oxide) and an oxidizing agent (for example, hydrogen peroxide or persulfuric acid). The basic mechanism of CMP using the metal slurry is to oxidize the metal surface by an oxidizing agent, and Grinding is performed by removing the oxide film from the abrasive particles (for example, refer to Journal of Electrochemical Society, 1991, Vol. 138, No. 11, pp. 3460-3464).

However, when CMP is performed using a polishing liquid for a metal containing such solid abrasive particles, there is a phenomenon that the polishing is scratched (scratched), the entire polishing surface is polished more than necessary (thinning), or the concave distortion occurs. Wear and so on.

Further, after the polishing, in order to remove the polishing liquid remaining in the semiconductor surface, the cleaning step is complicated by the use of the polishing liquid containing the solid abrasive particles, and after the cleaning is performed, The liquid (waste liquid) is present on the cost side where it is necessary to settle and separate solid abrasive particles.

One of the means for solving such a method is to disclose a metal surface grinding method which combines a polishing liquid containing no abrasive particles with dry etching (for example, the Journal of Electrochemical Society, 2000, Vol. 147, 10, pages 3907~3913). Further, a polishing liquid for a metal composed of hydrogen peroxide/malic acid/benzotriazole/polyammonium acrylate and water has been proposed (for example, see JP-A-2001-127019).

According to these methods, the metal film of the semiconductor base convex portion can selectively perform CMP, and the metal film remains in the concave portion to obtain a desired conductor pattern. The friction with the polishing pad is mechanically farther than the slurry containing the conventional solid abrasive particles, and since CMP is performed in this state, the occurrence of scratches is reduced.

However, since the physical polishing force is lowered, there is a drawback that it is difficult to obtain a sufficient polishing speed.

On the other hand, although the polishing agent containing the abrasive particles can obtain a high polishing rate, there is a problem that the concave twist polishing is easy to proceed.

For this reason, a method of using a specific organic acid in a polishing liquid has been proposed for the purpose of not increasing the content of the abrasive particles and obtaining a high polishing rate (for example, refer to JP-A-2000-183004), or with copper/ The organic acid structure of the polishing liquid which is excellent in the amount of the polishing liquid which is suitable for suppressing the occurrence of the concave distortion (for example, see JP-A-2006-179845), but the organic acid and the use energy can be obtained even at a higher polishing rate. In the case of a non-dynamic film-forming agent that suppresses the occurrence of concave distortion, the concave distortion after the first polishing step of copper is still insufficient. Further, in the chemical mechanical polishing step of a semiconductor device using a barrier layer made of titanium, there is a problem that the selection of the polishing rate of the barrier layer made of titanium and the conductive metal is relatively low.

SUMMARY OF THE INVENTION An object of the present invention is to provide a titanium alloy composed of a chemical mechanical polishing step of a semiconductor device using a barrier layer made of titanium while achieving a high polishing rate and effectively suppressing the occurrence of concave distortion. A metal polishing composition having a high selectivity to the polishing rate of the barrier layer and the conductive metal.

Further, it is an object of the present invention to provide a chemical mechanical polishing method using such a metal polishing composition.

In view of the above-mentioned facts, the present inventors have found that the above problems can be solved by using two or more kinds of nitrogen-containing heterocyclic compounds which inhibit copper dissolution in combination, and the present invention has been completed.

That is, the present invention has been achieved in accordance with the means described below.

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

In the formula (A), R ¹ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic ring, an alkoxy group, an amine group, a hydroxyl group, a carboxyl group or an amine carbenyl group, and R ² represents a hydrogen atom, an aliphatic hydrocarbon group, or an aromatic group. Or -C(=O)Z, Z represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, -NZ ¹ Z ² or -OZ ³ , and the Z ¹ , Z ² and Z ³ systems each independently represent hydrogen. An atom, an aliphatic hydrocarbon group or an aryl group,

In the general formulae (B), (C) and (D), R ³ , R ⁵ and R ⁸ each independently represent a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amine group or a hydroxyl group, and R ⁴ represents hydrogen. An atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, a carboxyl group or an amine carbenyl group, and R ⁶ , R ⁷ , R ⁹ and R ¹⁰ each independently represent a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. , alkoxy, amine, hydroxy, carboxy or aminemethanyl.

<2> The metal polishing composition according to <1>, which further contains abrasive particles.

<3> The metal polishing composition according to <1>, which further comprises at least one selected from the group consisting of a surfactant and a water-soluble polymer compound.

<4> The metal polishing composition according to <3>, wherein the surfactant has at least one of a sulfonic acid group and a phenyl group, and the water-soluble polymer compound has a guanamine bond.

(5) The metal polishing composition according to the above-mentioned item (1), wherein the compound represented by the above formula (A) is selected from the group consisting of 5-amino-1H-tetrazole and one or more of the following compound groups.

<6> The metal polishing composition according to <5>, wherein the compound represented by the above formula (A) is 5-amino-1H-tetrazole.

<7> The metal polishing composition according to the above-mentioned item (1), wherein the compound represented by the above formula (A) is one or more selected from the group consisting of the following compounds.

<8> The metal polishing composition according to <1>, wherein the R ⁴ of the above formula (B) has a substituent of an alkyl group.

<9> The metal polishing composition according to <4>, wherein at least one selected from the group consisting of the above surfactant and a water-soluble polymer compound is an alkyl diphenyl ether monosulfonic acid or a salt thereof, or an alkyl group Phenyl ether disulfonic acid or a salt thereof.

<10> The metal polishing composition according to <1>, which is used for polishing a conductive metal wiring made of copper.

The metal polishing composition according to any one of <1> to <10> wherein the semiconductor device has a barrier layer containing titanium and a conductive metal wiring, and the above-described chemical mechanical polishing step includes The selection ratio of the barrier layer of titanium to the polishing rate of the above-mentioned conductive metal is 200 or more.

<12> A chemical mechanical polishing method which will contain the following general formula (A) a compound selected from the group consisting of at least one of the compounds represented by the following general formulae (B), (C) and (D) and a metal polishing composition for an oxidizing agent, which is supplied to a polishing pad on a polishing disk, and A chemical mechanical polishing method of a semiconductor device in which a polishing pad is in contact with a surface to be polished of a semiconductor device and is relatively moved to perform polishing.

In the formula (A), R ¹ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic ring, an alkoxy group, an amine group, a hydroxyl group, a carboxyl group or an amine carbenyl group, and R ² represents a hydrogen atom, an aliphatic hydrocarbon group, or an aromatic group. Or -C(=O)Z, Z represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, -NZ ¹ Z ² or -OZ ³ , and the Z ¹ , Z ² and Z ³ systems each independently represent hydrogen. An atom, an aliphatic hydrocarbon group or an aryl group,

In the general formulae (B), (C) and (D), R ³ , R ⁵ and R ⁸ each independently represent a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amine group or a hydroxyl group, and R ⁴ represents hydrogen. An atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, a carboxyl group or an amine carbenyl group, and R ⁶ , R ⁷ , R ⁹ and R ¹⁰ each independently represent a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. , alkoxy, amine, hydroxy, carboxy or aminemethanyl.

(13) The chemical mechanical polishing method according to the above aspect, wherein the polishing surface of the semiconductor device is ground while the polishing pad is pressed at a pressure of 20 kPa or less, and the polishing pad and the semiconductor device are polished. The faces are in relative motion for grinding.

<14> The chemical mechanical polishing method according to <13>, wherein the metal polishing composition has a supply flow rate to the polishing pad of 190 mL/min or less.

<15> A chemical mechanical polishing method using a metal polishing composition according to any one of <1> to <11>, and a chemical device having a semiconductor device including a barrier layer containing titanium and a conductive metal wiring In the polishing step, the selection ratio of the polishing rate of the titanium-containing barrier layer to the conductive metal is 200 or more.

According to the present invention, it is possible to provide a resistance formed by titanium in a chemical mechanical polishing step of a semiconductor device which achieves a high polishing rate and which can effectively suppress the occurrence of concave distortion and which is a barrier layer made of titanium. A metal polishing composition having a high ratio of the polishing rate of the barrier layer to the conductive metal. Further, according to the present invention, it is possible to provide a chemical mechanical polishing method using such a metal polishing composition.

Best form for implementing the invention

Hereinafter, specific aspects of the invention will be described.

[Metal Grinding Composition]

The metal polishing composition of the present invention has at least one of (a) a compound represented by the formula (A) and at least one selected from the group consisting of the compounds represented by the formula (B), (C) and (D). And (c) oxidants are special.

Further, other compounds may be contained as needed.

The metal polishing composition of the present invention is generally in the form of a slurry obtained by dispersing (d) polishing particles in an aqueous solution obtained by dissolving each component.

The metal polishing composition of the present invention can be used as a polishing composition used for chemical mechanical polishing of a workpiece to be polished in the production of a semiconductor device.

In the following, each component constituting the metal polishing composition will be described in detail, and each component may be used alone or in combination of two or more.

Further, in the present invention, the metal polishing composition (hereinafter also referred to as "grinding composition") is not only used in the composition (concentration) used for polishing, but may be diluted as needed during use. In the aspect, the present invention is not particularly limited and is referred to as a composition for metal polishing. Since the concentrate can be used for polishing when it is diluted with water or an aqueous solution for polishing, the dilution ratio is generally 1 to 20 times by volume.

<(a) a compound represented by the formula (A)>

The polishing composition of the present invention contains (a) a compound represented by the formula (A). The compound represented by the following formula (A) is a nitrogen-containing heterocyclic compound containing four or more nitrogen atoms in the molecule and directly bonding the carbon atom of the ring to the NH group.

In the formula (A), R ¹ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic ring, an alkoxy group, an amine group, a hydroxyl group, a carboxyl group, or an amine carbenyl group, and R ² represents a hydrogen atom or an aliphatic hydrocarbon group. An aryl group, or -C(=O)Z, Z represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, -NZ ¹ Z ² , or -OZ ³ , and the Z ¹ , Z ² and Z ³ systems are each independently The ground represents a hydrogen atom, an aliphatic hydrocarbon group, or an aryl group.

In the above formula (A), the aliphatic hydrocarbon group represented by R ¹ may, for example, be an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms (in the present case, it means having a cycloalkenyl group or a bicyclic ring). An unsaturated aliphatic group of a double bond of an alkenyl group, an alkynyl group or the like.

The alkyl group represented by R ¹ may, for example, be a cycloalkyl group or a bicycloalkyl group, or a substituted or unsubstituted alkyl group having a linear or branched structure.

The linear, branched substituted or unsubstituted alkyl group is preferably an alkyl group having 1 to 30 carbon atoms. Examples thereof include methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, and trifluoro. Methyl, and 2-ethylhexyl.

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

The bicycloalkyl group may, for example, be a substituted or unsubstituted double having a carbon number of 5 to 30. A cycloalkyl group, that is, a valent group of one hydrogen atom is removed from a bicycloalkane having 5 to 30 carbon atoms. Examples thereof include bicyclo[1,2,2]hept-2-yl and bicyclo[2,2,2]octane-3-yl. Furthermore, a three-ring structure or the like having a large number of ring structures is also included. Hereinafter, the "alkyl group" in the substituent (for example, "alkyl group" of an alkylthio group) also means "alkyl group" as described above.

The alkenyl group represented by R ¹ contains a cycloalkenyl group or a bicycloalkenyl group. The alkenyl group means a linear, branched or cyclic substituted or unsubstituted alkenyl group. The alkenyl group is preferably a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms. Examples thereof include a vinyl group, an allyl group, an isoprenyl group, a geranyl group, and an oleyl group.

The cycloalkenyl group is preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, one valent group of one hydrogen atom is removed from a cyclic olefin having 3 to 30 carbon atoms. Examples thereof include 2-cyclopenten-1-yl and 2-cyclohexen-1-yl.

The bicycloalkenyl group contains a substituted or unsubstituted bicycloalkenyl group. The bicycloalkenyl group is preferably a substituted or unsubstituted dicycloalkenyl group having 5 to 30 carbon atoms, that is, a valent group having one hydrogen atom removed from a bicyclic olefin having one double bond. Examples thereof include bicyclo [2.2.1] hept-2-en-1-yl and bicyclo [2.2.2] oct-2-en-4-yl.

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, and examples thereof include a phenyl group, a p-tolyl group, a naphthyl group, an m-chlorophenyl group, and an o-tenth. Hexadecylaminophenyl.

The heterocyclic group represented by R ^{1 is} one which has one valent group of a hydrogen atom removed from a substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, and may be further condensed.

These heterocyclic groups are preferably a heterocyclic group of 5 or 6 members, and the hetero atom of the ring is preferably an oxygen atom, a sulfur atom or a nitrogen atom.

More preferably, it is a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms.

When the ring constituting the heterocyclic group is exemplified without limiting the substitution position, for example, a pyridine ring or a pyridyl group is mentioned. Ring, 嗒 Ring, pyrimidine ring, three Ring, quinoline ring, isoquinoline ring, quinazoline ring, porphyrin ring, porphyrin ring, quinoxaline ring, pyrrole ring, anthracene 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, benzoisoxazole ring , pyrrolidine ring, piperidine ring, piperazine Ring, imidazoline ring, thiazoline ring.

In the above formula (A), the aliphatic hydrocarbon group and the aryl group represented by R ^{2 are the same} as those of the aliphatic hydrocarbon group and the aryl group represented by the above R ¹ .

Further, when R ² in the above formula (A) represents -C(=O)Z, the aliphatic hydrocarbon group, the aryl group, the heterocyclic group represented by Z, and Z are -NZ ¹ Z ² or represent - The aliphatic hydrocarbon group and the aryl group represented by Z ¹ , Z ² and Z ³ in the case of OZ ^{3 are} also synonymous with the aliphatic hydrocarbon group, the heterocyclic group and the aryl group represented by the above R ¹ .

The group represented by R ¹ in the above formula (A) preferably represents a hydrogen atom. Further, R ² in the above formula (A) represents a hydrogen atom or -C(=O)Z, and represents a hydrogen atom. Further, the Z system in the case where R ² represents -C(=O)Z represents an aryl group, a heterocyclic group, -NZ ¹ Z ² or -OZ ^{3 , and} preferably -NZ ¹ Z ² is the most preferable.

Further, in the case where R ² in the above formula (A) is a substituent other than a hydrogen atom, these substituents are more preferably a substituent, and preferred substituents are, for example, a hydroxyl group, an amine group or an ether. a base, a mercaptoamine group, a sulfonylamino group, a sulfonium imino group, a carboxyl group, a sulfonic acid group, a quaternary ammonium group, an imidazolium group, a phosphonium group, etc., and a more preferred substituent is a hydroxyl group or an amine group. The ether group, the carboxyl group, the sulfonic acid group, and the 4-stage ammonium group are most preferably a hydroxyl group.

The specific compound represented by the formula (A) is preferably, for example, the ones described below.

Among the above compounds, 5-amino-H-tetrazole, A-4, A-14, A-15, A-16, A-18 are preferred, 5-amino-tetrazole, A-14 It is better.

The compound represented by the above formula (A) may be used alone or in combination of two or more kinds.

The amount of the compound represented by the formula (A) is preferably from 5 to 500 mg/L, more preferably from 10 to 200 mg/L, and from 20 to 150 mg/min, based on the total amount of the polishing composition. L is better.

<(b) a compound represented by the formula (B), the formula (C) or the formula (D)>

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

In the general formulae (B), (C) and (D), R ³ , R ⁵ and R ⁸ each independently represent a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amine group or a hydroxyl group.

The alkyl group represented by R ³ , R ⁵ and R ⁸ may be linear, branched or cyclic, and is preferably a linear chain. The alkyl group has a carbon number of 1 to 8, preferably 1 to 6 is preferred, and 1 to 3 is more preferred.

Specifically, the alkyl group may, for example, be a methyl group, an ethyl group, a propyl group or a butyl group. The pentyl group, the hexyl group, the heptyl group and the octyl group are preferably a methyl group, an ethyl group, a propyl group, a butyl group or a hexyl group, more preferably a methyl group, an ethyl group, a propyl group or a hexyl group.

The aryl group represented by R ³ , R ⁵ and R ⁸ may be an aromatic hydrocarbon ring or an aromatic hetero ring. The aryl group is preferably a carbon number of 6 to 12.

Specific examples thereof include a phenyl group and a naphthyl group, and a phenyl group is preferred.

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, preferably a nitrogen atom or an oxygen atom, more preferably a nitrogen atom.

The number of heterocyclic rings is preferably 5 to 10, 5 to 8 is preferred, and 5 to 6 is more preferred.

In the case where R ³ , R ⁵ and R ⁸ are a substituent other than a hydrogen atom, these substituents may further contain a substituent, and examples of the substituent which may be introduced include an alkyl group, a phenyl group, and a heterocyclic group. And a hydroxyl group, a carboxyl group, a sulfonic acid group, an amine mercapto group, a decylamino group, an amine group, an alkoxy group, etc.

In the formula (B), R ⁴ represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, a carboxyl group or an amine formazan group.

The alkyl group represented by R ⁴ may be any of a linear chain, a branched chain, and a cyclic chain, and is preferably a linear chain. The alkyl group is preferably a carbon number of 1 to 8, preferably 1 to 6, more preferably 1 to 3.

Specifically, the alkyl group may, for example, be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group or an octyl group, and a methyl group, an ethyl group, a propyl group, a butyl group or a hexyl group is preferred. More preferably, it is a methyl group, an ethyl group, a propyl group or a hexyl group.

The aryl group represented by R ⁴ may be an aromatic hydrocarbon ring or an aromatic hetero ring. The aryl group is preferably a carbon number of 6 to 12.

Specific examples thereof include a phenyl group and a naphthyl group, and a phenyl group is preferred.

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 heterocyclic rings is preferably 5 to 10, 5 to 8 is preferred, and 5 to 6 is more preferred.

In the case where R ⁴ is a substituent other than a hydrogen atom, these substituents may further contain a substituent, and examples of the substituent which may be introduced include an alkyl group, a phenyl group, a heterocyclic group, a hydroxyl group, a carboxyl group, and a sulfonic acid group. , aminomethyl sulfhydryl, amidino, an amine, an alkoxy group, and the like.

In the general formula (C) and the general formula (D), R ⁶ , R ⁷ , R ⁹ and R ¹⁰ each independently represent a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group or an amine group. Hydroxyl, carboxy or aminemethanyl.

The alkyl group represented by R ⁶ , R ⁷ , R ⁹ and R ¹⁰ may be linear, branched or cyclic, and is preferably a linear or branched chain.

The alkyl group is preferably a carbon number of 1 to 8, preferably 1 to 6, more preferably 1 to 3.

Specifically, the alkyl group may, for example, be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group or an octyl group, and a methyl group, an ethyl group, a propyl group, a butyl group or a hexyl group is preferred. More preferably, it is a methyl group, an ethyl group, a propyl group or a hexyl group.

The aryl group represented by R ⁶ , R ⁷ , R ⁹ and R ¹⁰ may be an aromatic hydroxy ring or an aromatic hetero ring. The aryl group is preferably a carbon number of 6 to 12.

Specific examples thereof include a phenyl group and a naphthyl group, and a phenyl group is preferred.

The hetero atom in the heterocyclic group represented by R ⁶ , R ⁷ , R ⁹ and R ¹⁰ 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 heterocyclic rings is preferably 5 to 10, 5 to 8 is preferred, and 5 to 6 is more preferred.

The alkoxy groups represented by R ⁶ , R ⁷ , R ⁹ and R ^{10 are} preferably 1 to 8 carbon atoms, preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.

R ⁶ , R ⁷ , R ⁹ and R ¹⁰ are in the case of a substituent other than a hydrogen atom. These substituents may further contain a substituent, and examples of the substituent which may be introduced include an alkyl group, a phenyl group, a heterocyclic group, a hydroxyl group, a carboxyl group, a sulfonic acid group, an amine formazan group, a decylamino group, an amine group, and the like. Alkoxy group and the like.

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

The specific compound represented by the formula (B) is preferably, for example, 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-propan-2-ol)-H-tetrazole 5-(2-propan-2-ol)-H-tetrazole 5-(1-butan-1-ol)-H-tetrazole 5-(1 -hex-1-ol)-H-tetrazole 5-(1-cyclohexanol)-H-tetrazole 5-(4-methyl-2-pentan-2-ol)-H-tetrazole 5-- Oxymethyl-H-tetrazole 5-ethenyl-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-tetra Iridazole 1-amino-5-methyl-tetrazole 1-H-tetrazole 1-H-tetrazole-5-acetic acid 1-H-tetrazole-5-carboxylic acid 1-H-tetrazole-5-prop 1-H-tetrazole-5-sulfonic acid 1-H-tetrazole-5-ol 1-H-tetrazole-5-aminocarboxamidine 1-H-tetrazole-5-aminocarbamic acid 5-A 5-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- Tetrazolium 5-aminomethyl-H-tetrazole 5-aminoethyl-H-tetrazole 5-(3-aminopropyl)-H-tetrazole

Among the above compounds, 5-methyl-tetrazole, 5-ethyl-tetrazole, 5-phenyl-H-tetrazole and 1-H-tetrazole are preferred.

The compound represented by the above formula (B) may be used alone or in combination of two or more kinds in the polishing composition.

The specific compound represented by the formula (C) is preferably, for example, those shown below.

1,2,3-triazole, 1,2,3-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-hydroxyethylaminecarbamyl)-1,2,3-triazole, 4-amine Methyl-1,2,3-triazole, 4-hydroxymethyl-1,2,3-triazole, 4-hexyl-1,2,3-triazole, 4,5-dimethyl-1 , 2,3-triazole, among the above compounds, 1,2,3-triazole, 4-hexyl-1,2,3-triazole is preferred, and 1,2,3-triazole is more good.

The compound of the above formula (C) may be used alone or in combination of two or more kinds.

The specific compound represented by the formula (D) is preferably, for example, 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-hydroxymethyl-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

Among the above compounds, 1,2,4-triazole and 3-amino-1,2,4-triazole are preferred, and 1,2,4-triazole is more preferred.

The compound represented by the above formula (D) may be used alone or in combination of two or more kinds in the polishing composition.

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

The total amount of the component (b) (the compound represented by the formula (B), (C) or (D)) in the polishing composition of the present invention is relative to the component (a) [formula (A) The amount of the compound shown is preferably from 10 to 100% by mass, preferably from 20 to 60% by mass.

Further, a preferred combination of the above component (a) and component (b) is a combination of a compound represented by the formula (A) and a compound represented by the formula (B) or the formula (C).

Further, in the case where two or more kinds of the components (b) are used in combination, a combination of the compound represented by the formula (A), the compound represented by the formula (B) and the compound represented by the formula (C) is preferred. The ratio of the compound represented by the formula (B)/the compound represented by the formula (C) in this case is preferably from 10 to 200 and preferably from 20 to 100.

<(c) oxidant>

The polishing composition of the present invention contains a compound (oxidizing agent) capable of oxidizing a suitable metal to be polished.

Examples of the oxidizing agent include hydrogen peroxide, peroxide, nitrate, iodate, periodate, hypochlorite, chlorite, chlorate, perchlorate, and peroxodisulfate. Dichromate, permanganate, ozone water and silver (II) salt, iron (III) salt.

The iron (III) salt is iron (III) in addition to inorganic iron (III) salts such as iron (III) nitrate, iron (III) chloride, iron (III) sulfate, and iron (III) bromide. Organic wrong salt is preferred.

In the case of using an organic salt of iron (III), the compound forming the iron (III) salt is, for example, acetic acid, citric acid, oxalic acid, salicylic acid, diethyldithiocarbamic acid, succinic acid. , tartaric acid, glycolic acid, glycine, alanine, aspartic acid, thioglycolic acid, ethylenediamine, 1,3-propanediamine, diethylene glycol, triethylene glycol, 1,2-ethane Mercaptan, malonic acid, glutaric acid, 3-hydroxybutyric acid, propionic acid, phthalic acid, isophthalic acid, 3-hydroxysalicylic acid, 3,5-dihydroxysalicylic acid, gallic acid, benzoin Examples of the acid, maleic acid, and the like, and the like, are, for example, an amine-based polycarboxylic acid and a salt thereof.

The amine-based polycarboxylic acid and salts thereof may, for example, be ethylenediamine-N,N,N',N'-tetraacetic acid, diethylenetriaminepentaacetic acid, 1,3-diaminopropane-N,N,N ',N'-tetraacetic acid, 1,2-diaminopropane-N,N,N',N'-tetraacetic acid, ethylenediamine-N,N'-disuccinic acid (racemate), B Diamine disuccinic acid (SS body), N-(2-carboxyethylate)-L-aspartate, N-(carboxymethyl)-L-aspartic acid, β-alanine diacetic acid , methylimidodiacetic acid, nitrilotriacetic acid, cyclohexanediaminetetraacetic acid, iminodiacetic acid, glycol ether diamine tetraacetic acid, B Diamine 1-N,N'-diacetic acid, ethylenediamine pro-hydroxyphenylacetic acid, N,N-indole (2-hydroxybenzyl)ethylenediamine-N,N-diacetic acid and the like and salts thereof. The type of the salt is preferably an alkali metal salt or an ammonium salt, and particularly preferably an ammonium salt.

Among them, an organic salt of hydrogen peroxide, iodate, hypochlorite, chlorate, persulfate or iron (III) is preferred, and an organic salt of iron (III) is preferred. The compound forming compound may, for example, be citric acid, tartaric acid or an amine polycarboxylic 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 (racemate), ethylenediamine disuccinic acid (SS body), N- (2-carboxylated ethyl)-L-aspartic acid, N-(carboxymethyl)-L-aspartic acid, β-alanine diacetic acid, methylimidodiacetic acid, nitrile Triacetic 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 The wrong body of ', N'-tetraacetic acid and ethylenediamine disuccinic acid (SS body) is optimal.

The amount of the oxidizing agent to be added is preferably from 0.003 mol to 8 mol, preferably from 0.03 mol to 6 mol, particularly preferably from 0.1 mol to 4 mol, per 1 L of the polishing composition used for polishing. In other words, the amount of the oxidizing agent to be added is preferably 0.003 mol or more from the point of ensuring sufficient oxidation of the metal and high CMP rate, and is preferably 8 mol or less from the point of preventing cracking of the polishing surface.

The polishing composition of the present invention may contain the following components as needed in addition to the above components. Hereinafter, an arbitrary component which can be applied to the polishing composition of the present invention will be described.

<(d) abrasive particles>

The polishing composition of the present invention preferably contains abrasive particles. Preferred abrasive particles are, for example, cerium oxide (precipitated cerium oxide, fumed cerium oxide, colloidal cerium oxide, synthetic cerium oxide), cerium oxide, aluminum oxide, titanium oxide, zirconium oxide, Cerium oxide, manganese oxide, etc., especially colloidal cerium oxide is preferred.

Preferably, the method for producing the colloidal cerium oxide particles used as the abrasive particles is, for example, Si (OC ₂ H ₅ ) ₄ , Si (sec-OC ₄ H ₉ ) ₄ , Si (OCH ₃ ) ₄ , Si. The octanol compound of (OC ₄ H ₉ ) ₄ is hydrolyzed by a sol-gel method. The colloidal particle size distribution thus obtained is very steep.

The primary particle diameter of the abrasive particles means that the particle size cumulative curve indicating the relationship between the particle diameter of the abrasive particles and the cumulative number of particles having the particle diameter is obtained, and the cumulative degree of the curve is 50% ( Point) particle size. For example, an apparatus for determining the particle size distribution is LB-500 manufactured by Horiba, Ltd., and the like.

The case where the particles of the abrasive particles are spherical may be directly measured, but the particle size of the amorphous particles is considered to be represented by the diameter of the sphere equal to the volume of the particles. The particle size can be measured by a variety of well-known methods such as photon correlation, laser diffraction, Coulter counting, etc., but the present invention uses observation or photography by a scanning microscope. A method of calculating the shape and size of each particle by a transmission electron micrograph of a replica method.

Specifically, the length is calculated from the projected area of the particles and the shadow of the replicated sample based on the known diffraction grating, and the volume of each particle is calculated. At this time, although depending on the particle size distribution However, it is preferable to measure 500 or more particles for statistical processing. This method is described in detail in paragraph number [0024] of JP-A-2001-75222, and the description thereof is also applicable to the present invention.

The average particle diameter (primary particle diameter) of the abrasive particles contained in the polishing composition of the present invention is preferably in the range of 20 to 70 nm, preferably 20 to 50 nm. In order to achieve a sufficient polishing rate, particles of 5 nm or more are preferred. Further, in order to prevent excessive frictional heat during polishing, the particle diameter is preferably 50 nm or less.

Further, in the range which does not impair the effects of the present invention, not only general inorganic abrasive particles as described above but also organic polymer particles may be used in combination. Further, depending on the purpose, colloidal cerium oxide which is surface-modified by using aluminate ions or boric acid ions, colloidal cerium oxide which controls surface potential, etc., colloidal cerium oxide which is subjected to various surface treatments, or a plurality of materials may be used. Composite abrasive particles and the like.

The amount of the abrasive particles to be added in the present invention is appropriately selected depending on the purpose, and is generally used in the range of 0.001 to 20% by mass based on the total mass of the metal polishing composition. In the present invention, the effect of the addition of the component (a) and the component (b) is such that even when the amount of the abrasive particles added is less than 1.0% by mass, excellent polishing properties can be exhibited, and the abrasive particles can be suppressed. From the viewpoint of scratches and the like, the amount of the abrasive particles added is preferably less than 1.0% by mass, preferably from 0.01 to 0.6% by mass.

<(e) is at least one selected from the group consisting of a surfactant and a water-soluble polymer compound>

The polishing composition of the present invention may contain (e) at least one selected from the group consisting of a surfactant and a water-soluble polymer compound.

The surfactant and/or the water-soluble polymer compound are preferably acid-type. In the case of forming a salt structure, for example, an ammonium salt, a potassium salt, a sodium salt or the like may be mentioned, and in particular, an ammonium salt or a potassium salt is preferred.

Each of the surfactant and/or the water-soluble polymer compound has an effect of lowering the contact angle with respect to the surface to be polished, and has an effect of promoting uniform polishing. The surfactant and/or water-soluble polymer compound to be used is preferably selected from the group consisting of the following.

The anionic surfactant may, for example, be a carboxylate, a sulfonate, a sulfate or a phosphate, and the carboxylate may, for example, be soap, N-decylamino acid salt, polyethylene oxide or poly ring. Oxypropane alkyl ether carboxylate, thiolated peptide; sulfonate may, for example, be an alkyl sulfonate, alkyl benzene and alkyl naphthalene sulfonate, naphthalene sulfonate, (alkyl) naphthalene sulfonic acid a formalin condensate, a (alkyl) naphthalenesulfonic acid formalin condensate, a sulfosuccinate, an α-olefin sulfonate, an N-mercaptosulfonate; the sulfate salt may, for example, be a sulfurized oil or an alkane a base sulfate, an alkyl ether sulfate, a polyethylene oxide or a polypropylene oxide alkyl allyl ether sulfate, an alkyl sulfhydryl sulfate; a phosphate salt may, for example, an alkyl phosphate or a poly Ethylene oxide or polypropylene oxide alkyl allyl ether phosphate.

The cationic surfactant may, for example, be an aliphatic amine salt, an aliphatic quaternary ammonium salt, a benzalkonium chloride salt, a phenylethylamine chloride, a pyridinium salt or an imidazolium salt; and the amphoteric surfactant may, for example, a carboxyl group. Betaine type, sulfobetaine type, aminocarboxylate, imidazolium betaine, lecithin, alkylamine oxide.

Examples of the nonionic surfactant include an ether type, an ether ester type, an ester type, and a nitrogen-containing type, and examples of the ether type include a polyethylene oxide alkyl group and an alkylphenyl ether. Alkyl allyl formaldehyde condensed polyethylene oxide ether, polyethylene oxide polypropylene oxide block polymer, polyethylene oxide polypropylene oxide alkyl ether, ether ester type can be exemplified by glycerides Polyethylene oxide ether, polyethylene oxide ether of sorbitan ester, polyethylene oxide ether of sorbitol ester, ester type can be exemplified by polyethylene glycol fatty acid ester, glyceride, Polyglycerol ester, sorbitan ester, propylene glycol ester, sucrose ester, nitrogen-containing type may be exemplified by fatty acid alkanolamine, polyoxirane fatty acid guanamine, polyethylene oxide alkyl decylamine Base.

Other examples include a fluorine-based surfactant and a polyfluorene-based surfactant.

Among them, the surfactant is preferably a surfactant having at least one sulfonic acid group and a phenyl group such as dodecylbenzenesulfonic acid or alkyldiphenylether monosulfonic acid.

Examples of the water-soluble polymer compound include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol alkyl ether, polyethylene glycol alkenyl ether, alkyl polyethylene glycol, and alkyl polyethylene glycol. Alcohol 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 Ethers such as alkenyl ether, alkyl polypropylene glycol, alkyl polypropylene glycol alkyl ether, alkyl polypropylene glycol alkenyl ether, alkenyl polypropylene glycol, alkenyl polypropylene glycol alkyl ether, and alkenyl polypropylene glycol alkenyl ether; Polysaccharides such as acid, pectic acid, carboxymethyl cellulose, curdlan and amylopectin; amino acid salts; polyaspartic acid, polyglutamine, polylysine, polymalic acid, Polymethacrylic acid, polymethylammonium methacrylate, polymethyl methacrylate, polymaleic acid, polyitaconic acid, poly-fumaric acid, poly(p-styrene carboxylic acid), polyacrylic acid Polyacrylamide, amine group polymerization Polycarboxylic acid and salts thereof such as acrylamide, polyacrylic acid ammonium salt, polyacrylic acid sodium salt, polylysine acid, polyamidomate ammonium salt, polyamidomate sodium salt and polyglyoxylic acid; polyvinyl alcohol, A vinyl polymer such as polyvinylpyrrolidone or polyacrylaldehyde.

However, in the case where the applicable substrate is a tantalum substrate for a semiconductor integrated circuit or the like, it is preferable that there is no contamination due to an alkali metal, an alkaline earth metal, a halogen or the like, so that the water-soluble polymer compound is preferably an acid type. In the case of forming a salt structure, an ammonium salt is preferred. The case where the substrate is a glass substrate or the like is not limited.

Among the above water-soluble polymer compounds, polylysine, polyammonium ammonium salt, polyamidate sodium salt, polyvinyl pyrrolidone, polypropylene decylamine, polyurea, polyamic acid A water-soluble polymer compound having a guanamine bond such as an ester is preferred.

The amount of the surfactant and/or the water-soluble polymer compound to be added is preferably 1 in the range of 0.0001 to 0.1 g, preferably 0.0005 to 0.05 g, and preferably 0.001 to 0.01 in the polishing composition for polishing. g is especially good. In other words, the amount of the surfactant and/or the water-soluble polymer compound to be added is preferably 0.001 g or more, and preferably 10 g or less from the viewpoint of preventing a decrease in the CMP rate.

Further, the weight average molecular weight of these surfactants and/or water-soluble polymer compounds is preferably from 500 to 100,000, particularly preferably from 2,000 to 50,000.

The surfactant may be used alone or in combination of two or more. The water-soluble polymer compound may 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 used herein and the oxidizing agent for the metal oxide are compounds having different structures, and it is not necessary to include the above-mentioned acid as an oxidizing agent. The acid here has an effect of promoting oxidation, adjusting pH adjustment, and acting as a buffer.

The organic acid is an organic compound capable of generating an acid, and preferably has at least one carboxyl group. The organic acid is preferably water-soluble, more preferably an amino acid.

The organic acid system is, for example, described in the specification of JP-A-2007-129167, and specifically, it is more preferably selected from the group below.

That is, for example, an amino acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanecarboxylic acid, 3,3-dimethylbutyric acid, 2-ethyl Butyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexane acid, n-octanoic acid, 2-ethylhexane acid, benzoic acid, glycolic acid, 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, lactic acid, and their ammonium or alkali metal salts Wait.

The above-mentioned amino acids (including amino acids of the first, second, and third stages, and amine polycarboxylic acids) are preferably water-soluble. It is more suitable to be selected from the group below.

For example, glycine, L-alanine, β-alanine, L-2-aminobutyric acid, L-nuronic acid, L-proline, L-leucine, L-white amine Acid, L-isoleucine, L-isoisoleucine, L-phenylalanine, L-proline, creatinine, L-uric acid, L-lysine, taurine, L-serine, L-threonine, L-besulamide, L-homoserine, L-tyramine, 3,5-diiodo-L-case Amine acid, β-(3,4-dihydroxyphenyl)-L-alanine, L-thyroxine, 4-hydroxy-L-proline, L-cysteine, L-methionine, L-Ethionine, L-lanine thiol, L-cystathion, L-cystine, L-cysteine, L-aspartate, L-glutamic acid, S-( Carboxymethyl)-L-cysteine, 4-aminobutyric acid, L-aspartate, L-glutamine, azase, L-arginine, L-cutosin , L-citrulline, δ-hydroxy-L-lysine, creatine, L-kynurenine, L-histidine, 1-methyl-L-histidine, 3-methyl-L - histidine, ergothione, L-tryptophan, hydroxyethyliminodiacetic acid, dihydroxyethylglycine, N-hydroxyethylglycine, N-hydroxyethyl-α- Alanine, actinomycin C1, bee venom peptide, hypertension protein I, hypertension protein II and anti-papaya enzyme.

In particular, malic acid, tartaric acid, citric acid, glycine acid, glycolic acid, and hydroxyethyliminodiacetic acid are preferred from the viewpoint of maintaining a practical CMP rate and effectively suppressing the etching rate.

The amount of the organic acid to be added is preferably 0.0005 to 0.5 mol, preferably 0.005 mol to 0.3 mol, and preferably 0.01 mol to 0.1 mol, in 1 L of the metal polishing composition (use liquid) used for polishing. good. In other words, the amount of the acid to be added is preferably 0.5 mol or less from the viewpoint of suppressing etching, and more preferably 0.0005 mol or more in order to obtain a sufficient effect.

<phosphate or phosphite>

In the case where the polishing composition of the present invention contains an inorganic component other than the abrasive particles, it is preferred to contain a phosphate or a phosphite.

<pH of the polishing composition>

In the polishing composition of the present invention, it is preferred to The type, amount of addition, or pH of the above components is set in terms of reactivity, adsorbability, solubility of the polishing metal, electrochemical properties of the surface to be polished, dissociation state of the compound functional group, stability as a liquid, and the like.

The pH of the polishing composition of the present invention is preferably from 3 to 9 and preferably from pH 3.8 to 8.0 from the viewpoint of planarization performance. The pH system can be easily adjusted by appropriately selecting a buffer, an alkali agent, a mineral acid or the like.

[wiring metal raw materials]

In the present invention, the target semiconductor to be polished is preferably an LSI having a wiring made of a copper metal and/or a copper alloy, and is particularly preferably a copper alloy. Further, among copper alloys, copper alloy containing silver is particularly preferred. The content of silver contained in the copper alloy is preferably 40% by mass or less, particularly preferably 10% by mass or less, and preferably 1% by mass or less, and the copper alloy in the range of 0.00001 to 0.1% by mass can exhibit the most excellent effect.

[roughness of wiring]

In the present invention, the semiconductor device to be polished, for example, a DRAM device system, has a half pitch of 0.15 μm or less, particularly 0.10 μm or less, and further preferably 0.08 μm or less. On the other hand, in the MPU device system, an LSI having a wiring of 0.12 μm or less, particularly 0.09 μm or less, and further 0.07 μm or less is preferable. With respect to these LSIs, the polishing liquid system of the present invention can exhibit particularly excellent effects.

[barrier metal]

In the present invention, a semiconductor is provided with a barrier layer for preventing copper diffusion between a wiring made of a copper metal and/or a copper alloy and an interlayer insulating film. It is better. The barrier layer is preferably a low-resistance metal material, particularly TiN, TiW, Ta, TaN, W, WN, and Ru, and particularly preferably Ta, TaN, Ti, TiN, and TiW.

[grinding method]

The polishing composition of the present invention is a case where the concentrate is diluted with water to form a use liquid, or each component is mixed in the form of an aqueous solution as described in the following, and diluted with water to form a use liquid as needed. Or modulation into the use of liquid.

The polishing method using the polishing composition of the present invention can be applied in any case, and the polishing composition is supplied to the polishing pad on the polishing disk, and is brought into contact with the surface to be polished so that the surface to be polished and the polishing pad move relative to each other. A grinding method for grinding.

As a device for polishing, a general polishing device that holds a semiconductor substrate having a surface to be polished or the like and a polishing disk having a polishing pad to which a motor having a variable number of rotations can be attached can be used.

The polishing pad can be particularly limited by using a general nonwoven fabric, a foamed polyurethane, a porous fluororesin or the like.

The polishing conditions are not particularly limited, but the rotation speed of the polishing turntable is preferably a low rotation of 200 rpm or less in which the substrate does not fly out.

The pressure of the semiconductor substrate having the surface to be polished (the film to be polished) to press the polishing pad is preferably 20 kPa or less, and is preferably 6 to 15 kPa in order to satisfy the in-plane uniformity of the polishing rate and the flatness of the pattern.

The polishing composition is continuously supplied to the polishing pad by a pump or the like between the polishing. The supply amount is not particularly limited to the surface of the polishing pad It is always possible to cover the polishing composition.

After the semiconductor substrate after the polishing is carefully washed in the running water, the water droplets adhering to the semiconductor substrate are shaken off using a spin dryer or the like, and then dried, and when the polishing composition of the present invention is used, the polishing after polishing is performed. The netness becomes good. It is presumed to be caused by the electrostatic repulsion of the abrasive particles and the wiring metal.

In the polishing method of the present invention, the diluted aqueous solution is the same as the aqueous solution described below.

The aqueous solution contains at least one of a pre-oxidizing agent, an acid, an additive, and a surfactant, and the total component of the component contained in the aqueous solution and the component of the diluted polishing composition is used as a polishing composition. The ingredients at the time of grinding.

In the case of being diluted with an aqueous solution, a component which is difficult to dissolve can be blended into a more concentrated polishing composition in accordance with the type of the aqueous solution.

A method of adding water to a concentrated polishing composition and diluting it by mixing and mixing the piping for supplying the concentrated polishing composition with the water supply pipe, and mixing and diluting the polishing composition A method of supplying to a polishing pad.

The mixing system is a method in which liquids are collided and mixed by a narrow passage in a state where pressure is applied, a glass tube is filled in a pipe, and the like, and a flow of the separation and separation liquid is repeated to join the flow, and the power is set in the pipe. A generally implemented method such as a method of rotating a blade.

The supply rate of the polishing composition can be suitably selected in the range of 10 to 1000 ml/min, but the physical properties of the polishing composition of the present invention are considered. Preferably, it is preferably 190 ml/min or less, and preferably 100 to 190 ml/min.

A method of diluting and polishing a concentrated polishing composition by an aqueous solution or the like, and separately providing a pipe for supplying a polishing composition and a pipe for supplying water or an aqueous solution, and supplying a predetermined amount of liquid to the polishing pad, A method in which the polishing pad is mixed with the surface to be polished and subjected to grinding.

Alternatively, a method in which a predetermined amount of the concentrated polishing composition is mixed with water in one container, and the mixed polishing composition is supplied to a polishing pad to be polished.

In the other polishing method of the present invention, the components to be contained in the polishing composition are divided into at least two kinds of components, and the polishing pad which is diluted with water and supplied to the polishing disk is used in contact with the surface to be polished. A method of grinding the surface to be polished and the polishing pad to move relative to each other.

For example, when the oxidizing agent is used as one of the constituents (A), and the acid, the additive, the surfactant, and water are regarded as one of the constituents (B), the constituents may be diluted with water while using them. (A) is used together with the component (B).

Further, the additive having low solubility is divided into two kinds of constituent components (A) and (B), and an oxidizing agent, an additive, and a surfactant are regarded as one of the constituent components (A), an acid, an additive, a surfactant, and water. The component (B), which is one of them, can be used by adding the component (A) and the component (B) by adding water while using them.

In the case of this example, it is necessary to separately supply the constituent component (A) and constitute The three components of the component (B) and the water are mixed and mixed, and three pipes are combined with one pipe supplied to the polishing pad to be mixed in the pipe. In this case, after the two pipes are combined, Combined with another pipe.

For example, there is a method in which a constituent component containing an additive which is difficult to dissolve is mixed with another constituent component, and a mixing path is increased to secure a dissolution time, and then combined with a water pipe.

Other mixing methods include direct mixing of three pipes to the polishing pad as described above, mixing by the relative movement of the polishing pad and the surface to be polished, and mixing three kinds of constituent components in one container and The method of supplying the diluted polishing composition to the polishing pad.

In the above polishing method, one of the constituent components containing the oxidizing agent is heated from room temperature to 100 ° C at 40 ° C or lower, and one of the constituent components is added to the other constituent components or When it is diluted with water, it may be 40 ° C or less after mixing. Since the solubility is high when the temperature is high, it is a suitable method for improving the solubility of a raw material having a low solubility in the polishing composition.

When the other component containing no oxidizing agent is heated and dissolved in the range of room temperature to 100 ° C, it will precipitate in the solution when the temperature is lowered. Therefore, when the temperature is lowered and the component is used, it must be preheated. In order to dissolve the precipitater. Here, a means for applying a liquid to dissolve the constituent liquid can be used, and a means for stirring the liquid containing the precipitate in advance, and supplying the liquid and heating the tube to dissolve it can be used.

When the temperature of the warmed component is one of the constituents containing the oxidizing agent is raised to 40 ° C or more, since the oxidizing agent is likely to decompose, it is The mixing is carried out at a temperature of 40 ° C or lower in a case where one of the constituent components of the oxidizing agent containing the warmed constituent component and the warmed constituent component is mixed.

Moreover, in the present invention, the components of the polishing composition as described above may be classified into two or more types and supplied to the polishing surface. In this case, it is preferably classified into a component containing an oxide and a component containing an acid and supplied. Further, the polishing composition is a concentrated liquid, and the dilution water may be separately supplied to the polishing surface.

[gasket]

The gasket for polishing may be a non-foamed structural gasket or a foamed structural gasket. The former is used for a gasket made of a synthetic resin block material such as a plastic plate.

In addition, the latter is composed of three types of independent foam (dry foaming), continuous foam (wet foaming), and two-layer composite (layered), and in particular, two-layer composite (layered) It is better. The foaming system can be uniform or non-uniform.

Further, abrasive particles (for example, cerium oxide, cerium oxide, aluminum oxide, resin, or the like) used for polishing may be contained. Further, the hardness may be either a soft one or a hard one, and any one may be used. It is preferable to use a hardness different from each layer in the laminated system.

The material is preferably non-woven fabric, artificial leather, polyamide, polyurethane, polyester, polycarbonate, and the like.

Further, in the surface in contact with the polishing surface, processing such as a lattice groove, a hole, a concentric groove, or a spiral groove may be performed.

[wafer]

The target wafer to be subjected to CMP by the polishing composition of the present invention preferably has a diameter of 200 mm or more, particularly preferably 300 mm or more. At 300mm The effect of the present invention can be remarkably exerted when it is applied.

Example

Hereinafter, the present invention will be described based on examples. The present invention is not limited by the embodiments.

(Example 1)

- Grinding composition -

(Examples 2 to 10)

The polishing of Examples 2 to 7 and Example 10 was obtained in the same manner as in Example 1 except that the components (a) and (b) used in Example 1 were replaced with those described in Table 1 below. Composition.

In the polishing composition of Example 1, 10 ppm of anionic surfactant dodecylbenzenesulfonic acid (described as "DBS" in Table 1) was added as a component (e). Use the composition.

In the polishing composition of Example 1, 200 ppm of a water-soluble polymer compound (e) which is a component (e), that is, polyvinylpyrrolidone (15K) was added (indicated as "PVP" in Table 1 ") A polishing composition.

(Comparative Example 1)

The polishing composition of Comparative Example 1 was obtained in the same manner as in Example 1 except that the component (b) was not added in Example 1.

(Comparative Example 2)

The polishing composition of Comparative Example 2 was obtained in the same manner as in Example 2 except that the component (b) was not added in Example 2.

(Comparative Example 3)

The polishing composition of Comparative Example 3 was obtained in the same manner as in Example 3 except that the component (b) was not added in Example 3.

(Comparative Example 4)

The polishing composition of Comparative Example 4 was obtained in the same manner as in Example 1 except that the component (a) was not added in Example 1.

The polishing compositions prepared in Examples 1 to 10 and Comparative Examples 1 to 4 were diluted with water to adjust the slurry S-1 to S-14, and stored at room temperature for 6 months. Then, grinding was performed in accordance with the grinding method shown below to evaluate the polishing performance (grinding speed, concave distortion, copper/titanium selection ratio). The evaluation results are shown in Table 1.

<Grinding speed evaluation>

The apparatus "FREX-300" manufactured by EBARA Co., Ltd. was used as a polishing apparatus, and the film provided on each wafer was polished while supplying the slurry under the following conditions, and the polishing rate at this time was calculated.

Turntable rotation number: 104rpm rotor rotation number: 105rpm (Processing line speed = 1.0 m/s) Grinding pressure: 105 hPa Grinding pad: Rohm & Haas company IC-1400 (K) Slurry supply speed: 190 ml/min. Measurement of grinding speed: Four short needle thicknesses were used before and after grinding. The film thickness was measured and found using the following formula.

Grinding speed (nm/min) = (film thickness before grinding - film thickness after grinding) / grinding time

<Concave distortion evaluation>

The apparatus "FREX-300" manufactured by EBARA Co., Ltd. was used as a polishing apparatus, and the film provided on each wafer of the pattern was polished while supplying the slurry under the following conditions, and the step at this time was measured.

Substrate: The germanium oxide film is patterned by a lithography step and a reactive ion etching step to form a wiring trench and a connection hole having a width of 0.09 to 100 μm and a depth of 600 nm, and a thickness of 20 nm is formed by sputtering. After the Ta film was formed into a copper film having a thickness of 50 nm by sputtering, a 12-inch wafer having a total thickness of 1000 nm of a copper film was formed by electroplating.

Number of rotations of the turntable: 50 rpm Rotary rotation number: 50 rpm Grinding pressure: 105 hPa Grinding pad: Rodel Nitta Co., Ltd. Part number IC-1400 (K) Slurry supply speed: 200 ml/min Step difference measurement: using a stylus type A step difference meter was used to measure the step difference of L/S at 100 μm/100 μm.

<copper/titanium selection ratio>

Measurement of selection ratio: According to the above conditions, the polishing rate of each of the tantalum wafer with the copper film and the tantalum wafer with the titanium film was determined and calculated by the following formula.

Selection ratio = polishing rate of copper film (nm / min) / polishing rate of titanium film (nm / min)

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

As is apparent from Table 1, examples containing the compound of the formula (A), that is, the compound of the component (a) and the compound of the component (b) represented by the formula (B), (C) or (D) Each of the polishing compositions of 1 to 10 can suppress the concave distortion while maintaining a sufficient polishing rate, and has a selection ratio of a polishing rate of the barrier layer made of titanium and the conductive metal.

Further, in Comparative Examples 1 to 3 which did not contain the component (b), and the polishing composition of Comparative Example 4 which did not contain the component (a), the suppression of the concave twist was insufficient, and it was composed of titanium. The selection of the polishing rate of the barrier layer and the conductive metal is relatively low.

Claims (15)

A metal polishing composition which is a metal polishing composition for chemical mechanical polishing of a conductive metal wiring mainly for a semiconductor device, which comprises the following compound (A), at least one selected from the following formula ( And a compound represented by C) and (D), wherein the compound (A) is selected from the group consisting of 5-amino-1H-tetrazole and one or more of the following compound groups; In the general formulae (C) and (D), R ⁵ and R ⁸ each independently represent a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amine group or a hydroxyl group, and R ⁶ , R ⁷ , R ⁹ and R Each of ¹⁰ groups independently represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an amine group, a hydroxyl group, a carboxyl group or an aminecarbamyl group, and any of R ⁵ to R ¹⁰ represents a substituent other than a hydrogen atom. In the case, the substituents may further contain a group selected from the group consisting of an alkyl group, a phenyl group, a heterocyclic group, a hydroxyl group, a carboxyl group, a sulfonic acid group, an amine methyl sulfonyl group, a decylamino group, an amine group, and an alkoxy group. Substituents for the group. The metal polishing composition according to claim 1, wherein the abrasive particles are further contained. The metal polishing composition according to the first aspect of the invention, further comprising at least one selected from the group consisting of a surfactant and a water-soluble polymer compound. The metal polishing composition according to claim 3, wherein the surfactant has at least one of a sulfonic acid group and a phenyl group, and the water-soluble polymer compound has a guanamine bond. The metal polishing composition according to the first aspect of the invention, wherein the compound (A) is 5-amino-1H-tetrazole. The metal polishing composition according to the first aspect of the invention, wherein the compound (A) is a compound represented by the following formula, The metal polishing composition according to claim 1, wherein the compound (A) is selected from the group consisting of 5-amino-1H-tetrazole, A-4, A-14 and A-18. The compound represented by the formula (C) is 1,2,3-triazole, and the compound represented by the formula (D) is 1,2,4-triazole. The metal polishing composition according to claim 4, wherein at least one selected from the group consisting of the above surfactant and the water-soluble polymer compound is an alkyl diphenyl ether monosulfonic acid or a salt thereof, or an alkyl diphenyl group. Ethyl ether disulfonic acid or a salt thereof. The metal polishing composition according to the first aspect of the invention is for polishing a conductive metal wiring made of copper. The metal polishing composition according to any one of claims 1 to 9, wherein the semiconductor device has a barrier layer containing titanium and a conductive metal wiring, and the titanium-containing layer is used in the chemical mechanical polishing step. The selection ratio of the barrier layer to the polishing rate of the conductive metal is 200 or more. A chemical mechanical polishing method for supplying a metal polishing composition containing at least one compound selected from the group consisting of the following compounds (A) and (D) and an oxidizing agent to a grinding wheel; A chemical mechanical polishing method for a semiconductor device in which a polishing pad is brought into contact with a polished surface of a semiconductor device and moved relative to each other to perform polishing, wherein the compound (A) is selected from 5-amino-1H-tetrazole And one or more of the following compound groups, In the general formulae (C) and (D), R ⁵ and R ⁸ each independently represent a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amine group or a hydroxyl group, and R ⁶ , R ⁷ , R ⁹ and R ^{10 .} Each independently represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an amine group, a hydroxyl group, a carboxyl group or an aminecarbamyl group, and any of R ⁵ to R ¹⁰ represents a substituent other than a hydrogen atom. In some cases, the substituents may further comprise a group selected from the group consisting of an alkyl group, a phenyl group, a heterocyclic group, a hydroxyl group, a carboxyl group, a sulfonic acid group, an amine methyl sulfonyl group, a decylamino group, an amine group, and an alkoxy group. Substituent. The chemical mechanical polishing method according to claim 11, wherein the polishing surface of the semiconductor device is such that the polishing pad and the polished surface of the semiconductor device are pressed while the polishing pad is pressed at a pressure of 20 kPa or less. For relative motion for grinding. For example, the chemical mechanical polishing method of claim 11 or 12, wherein The supply flow rate of the metal polishing composition to the polishing pad is 190 mL/min or less. The chemical mechanical polishing method according to claim 11, wherein the compound (A) is selected from the group consisting of 5-amino-1H-tetrazole, A-4, A-14 and A-18. The compound represented by the formula (C) is 1,2,3-triazole, and the compound represented by the formula (D) is 1,2,4-triazole. A chemical mechanical polishing method using a metal polishing composition according to any one of claims 1 to 10, and a chemical mechanical polishing step of a semiconductor device having a barrier layer containing titanium and a conductive metal wiring The selection ratio of the polishing rate of the titanium-containing barrier layer to the conductive metal is 200 or more.