JP5448396B2 - Polishing liquid for metal - Google Patents

Description

  The present invention relates to a polishing liquid used in a manufacturing process of a semiconductor device, and more particularly to a polishing liquid suitably used for polishing a barrier layer mainly made of a barrier metal material in planarization in a wiring process of a semiconductor device.

  In the development of semiconductor devices typified by semiconductor integrated circuits (hereinafter sometimes referred to as “LSI”), in recent years, miniaturization and stacking of wiring has led to higher density and higher integration for miniaturization and higher speed. Is required. Various techniques such as chemical mechanical polishing (hereinafter, also referred to as “CMP”) have been used as techniques for this purpose. This CMP is an indispensable technique for surface flattening of processed films such as interlayer insulation films, plug formation, formation of embedded metal wiring, etc., and smoothing of the substrate and removal of excess metal thin film during wiring formation In addition, an excess barrier layer on the insulating film is removed.

A general method of CMP is to apply a polishing pad on a circular polishing platen (platen), immerse the surface of the polishing pad with a polishing liquid, press the surface of the substrate (wafer) against the pad, In a state where pressure (polishing pressure) is applied, both the polishing platen and the substrate are rotated, and the surface of the substrate is flattened by the generated mechanical friction.
When manufacturing semiconductor devices such as LSI, fine wiring is formed in multiple layers, and when forming metal wiring such as Cu in each layer, diffusion of wiring material to the interlayer insulating film In order to prevent this and to improve the adhesion of the wiring material, a barrier metal such as Ta, TaN, Ti, or TiN is formed in advance.

  In order to form each wiring layer, first, a one-stage or multi-stage CMP of a metal film (hereinafter sometimes referred to as “metal film CMP”) for removing excess wiring material deposited by plating or the like is performed. Next, CMP is generally performed to remove the barrier metal material (barrier metal) exposed on the surface by this (hereinafter also referred to as “barrier metal CMP”). However, there is a problem that the metal film CMP causes so-called dishing in which the wiring portion is excessively polished and further causes erosion.

  To reduce this dishing, the barrier metal CMP performed after the metal film CMP adjusts the polishing speed of the metal wiring portion and the polishing speed of the barrier metal portion, and finally the wiring having few steps such as dishing and erosion. There is a need to form a layer. That is, in the barrier metal CMP, when the polishing rate of the barrier metal or the interlayer insulating film is relatively small compared to the metal wiring material, the polishing process takes time, so the metal film in the wiring portion is harder than the hard barrier metal. As a result, dishing and erosion as a result are likely to occur, such as being polished quickly. For this reason, it is desirable that the polishing rate of the barrier metal or the insulating film layer is appropriately high.

The metal polishing solution used for CMP generally contains abrasive grains (for example, alumina and silica) and an oxidizing agent (for example, hydrogen peroxide and persulfuric acid). It is considered that the basic mechanism is polishing by oxidizing the metal surface with an oxidizing agent and removing the oxide film with abrasive grains.
However, when CMP is performed using a polishing liquid containing such solid abrasive grains, scratches (scratches), a phenomenon in which the entire polished surface is polished more than necessary (thinning), and only the center of the polished metal surface is deeper. The phenomenon that a dish-shaped dent is caused by polishing (dishing), the insulator between metal wirings is polished more than necessary, and the surface of multiple wiring metal surfaces forms dish-shaped recesses (erosion). There are things to do.

  As means for solving these problems, for example, Patent Documents 1 and 2 describe that it is effective to incorporate 1,2,3-benzotriazole or 2-aminothiazole in the polishing liquid. 3 and 4 describe that benzotriazole derivatives are effective.

However, even with the above-described polishing liquid, the present situation is that a technique capable of realizing a high polishing rate and suppressing scratches when polishing the barrier layer has not yet been obtained.
JP-A-8-64594 JP-A-8-83780 WO2008-004579A1 WO2007-126672A1

  An object of the present invention is a polishing liquid used for barrier CMP for polishing a barrier layer mainly made of a barrier metal material, which provides an excellent polishing rate for the barrier layer and can achieve scratch suppression. To provide liquid.

As a result of intensive studies, the present inventor has found that the above problem can be solved by using the following polishing liquid, and has achieved the object.
In particular, the metal polishing liquid of the present invention provides an excellent polishing rate for the barrier layer and is effective in suppressing scratches caused by corrosion inhibitors such as benzotriazole.
Specific means for solving the above problems are as follows.

<1> Used for chemical mechanical polishing in a semiconductor device manufacturing process, (a) a compound represented by the following general formula (1), (b) an oxidizing agent, (c) an organic acid, and (d) 2 At least selected from the group consisting of ethanolamine, 2,3-dihydroxypropylamine, 2-amino-1,3-propanediol, 3-amino-1,2-propanediol, morpholine, and bishydroxyethylethylenediamine A metal polishing liquid containing an amine containing an oxygen atom in one kind of molecule.

In general formula (1), X and Y each independently represent a nitrogen atom or CR ⁵ . R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom, halogen atom, aliphatic hydrocarbon group, aryl group, heterocyclic group, carboxy group, alkyloxy group, aryloxycarbonyl group, carbamoyl Represents a group, an acylamino group, an amino group, or a cyano group. Q ¹ and Q ² each independently represent a hydrogen atom or an aliphatic hydrocarbon group. Z represents —OR ⁶ or —NR ⁷ R ⁸ . R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. R ¹ , R ² , R ³ and R ⁴ may combine with each other to form a ring. Q ¹ , Q ² and Z may be bonded to each other to form a ring. When X and Y represent CR ⁵ , each CR ⁵ may be bonded to form a ring.

<2 >
Before following general formula (1) is a compound represented by a compound represented by the following general formula (1-2) wherein <1> metal polishing slurry according to.

In the general formula (1-2), X represents a nitrogen atom or CR ^5. R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom, halogen atom, aliphatic hydrocarbon group, aryl group, heterocyclic group, carboxy group, alkyloxy group, aryloxycarbonyl group, carbamoyl A group, an acylamino group, an amino group, or a cyano group, at least one of which represents a substituent other than a hydrogen atom. R ⁶ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. R ⁵ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. R ¹ , R ² , R ³ and R ⁴ may combine with each other to form a ring.

< 3 > The metal polishing slurry according to <1 >, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (1-3).

In the general formula (1-3), Y represents a nitrogen atom or CR ^5. Q ¹ and Q ² each independently represent a hydrogen atom or an aliphatic hydrocarbon group. R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom, halogen atom, aliphatic hydrocarbon group, aryl group, heterocyclic group, carboxy group, alkyloxy group, aryloxycarbonyl group, carbamoyl A group, an acylamino group, an amino group, or a cyano group, at least one of which represents a linear alkyl group, a branched alkyl group, a cyclic alkyl group, or a carbamoyl group. R ⁵ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. R ¹ , R ² , R ³ and R ⁴ may combine with each other to form a ring. Q ¹ and Q ² may be bonded to each other to form a ring.

< 4 > R ¹ and R ² in the general formula (1), general formula (1-2), and general formula (1-3) are each independently a hydrogen atom, a linear alkyl group, a branched alkyl group, or The metal polishing slurry according to any one of <1> to < 3 >, which is a cyclic alkyl group, an aryl group, or a heterocyclic group.
< 5 > The metal polishing slurry according to any one of <1> to < 4 >, further comprising a compound represented by the following general formula (2).

In general formula (2), X and Y each independently represent a nitrogen atom or CR ⁵ , and R ²¹ , R ²² , R ²³ , and R ²⁴ each independently represent a hydrogen atom, a halogen atom, aliphatic carbonization A hydrogen group, an aryl group, a heterocyclic group, an alkyloxy group, a carboxy group, a carbamoyl group, an acylamino group, an amino group, or a cyano group is represented. R ⁵ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. R ²¹ , R ²² , R ²³ and R ²⁴ may combine with each other to form a ring. When X and Y represent CR ⁵ , each CR ⁵ may be bonded to form a ring.

< 6 > The metal polishing slurry according to < 5 >, wherein the compound represented by the general formula (2) is benzotriazole.
< 7 > The content ratio in the metal polishing liquid of the compound represented by the general formula (1) and the compound represented by the general formula (2) is in the range of 1: 9 to 9: 1. The metal polishing slurry according to < 5 > or < 6 >.

< 8 > The metal polishing slurry according to any one of <1> to < 7 >, further containing a quaternary ammonium salt.
< 9 > The metal polishing slurry according to any one of <1> to < 8 >, further containing an anionic surfactant.

< 10 > The metal polishing slurry according to any one of <1> to < 9 >, wherein the pH is 2.5 to 5.0.
< 11 > The metal polishing slurry according to any one of <1> to < 10 >, further containing abrasive grains.
<12> The polishing liquid for metal according to any one of <1> to <11> is supplied to a polishing pad on a polishing surface plate, and the polishing pad is rotated by rotating the polishing surface plate. A polishing method in which polishing is performed by making a relative movement while being in contact with a surface to be polished of a body to be polished.

ADVANTAGE OF THE INVENTION According to this invention, the grinding | polishing liquid and the grinding | polishing method which can obtain the outstanding grinding | polishing speed | rate with respect to a barrier layer, and can achieve suppression of a scratch can be provided.

Hereinafter, the metal polishing liquid and the polishing method using the same of the present invention will be described in detail.

[Polishing liquid]
The polishing liquid of the present invention is used for chemical mechanical polishing in a semiconductor device manufacturing process, and (a) a compound represented by the following general formula (1), (b) an oxidizing agent, (c) an organic acid, and (D) From the group consisting of 2-ethanolamine, 2,3-dihydroxypropylamine, 2-amino-1,3-propanediol, 3-amino-1,2-propanediol, morpholine, and bishydroxyethylethylenediamine A metal-polishing liquid containing an amine containing at least one selected oxygen atom (hereinafter, appropriately referred to as a specific amine).

In general formula (1), X and Y each independently represent a nitrogen atom or CR ⁵ . R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom, halogen atom, aliphatic hydrocarbon group, aryl group, heterocyclic group, carboxy group, alkyloxy group, aryloxycarbonyl group, carbamoyl Represents a group, an acylamino group, an amino group, or a cyano group. Q ¹ and Q ² each independently represent a hydrogen atom or an aliphatic hydrocarbon group. Z represents —OR ⁶ or —NR ⁷ R ⁸ . R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. R ¹ , R ² , R ³ and R ⁴ may combine with each other to form a ring. Q ¹ , Q ² and Z may be bonded to each other to form a ring. When X and Y represent CR ⁵ , each CR ⁵ may be bonded to form a ring.

  In the present invention, the “polishing liquid” means not only a polishing liquid used for polishing (that is, a polishing liquid diluted as necessary) but also a concentrated liquid of the polishing liquid. The concentrated liquid or the concentrated polishing liquid means a polishing liquid adjusted to have a higher solute concentration than the polishing liquid used for polishing, and is diluted with water or an aqueous solution when used for polishing. And used for polishing. The dilution factor is generally 1 to 20 volume times. In this specification, “concentration” and “concentrated liquid” are used in accordance with conventional expressions meaning “thick” and “thick liquid” rather than the state of use, and generally involve physical concentration operations such as evaporation. The term is used in a different way from the meaning of common terms.

  Hereinafter, each component contained in the metal polishing slurry of the present invention will be described in detail.

[(A) Compound represented by Formula (1)]
The metal polishing slurry of the present invention contains (a) a compound represented by the following general formula (1).

In general formula (1), X and Y each independently represent a nitrogen atom or CR ⁵ . R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom, halogen atom, aliphatic hydrocarbon group, aryl group, heterocyclic group, carboxy group, alkyloxy group, aryloxycarbonyl group, carbamoyl Represents a group, an acylamino group, an amino group, or a cyano group. Q ¹ and Q ² each independently represent a hydrogen atom or an aliphatic hydrocarbon group. Z represents —OR ⁶ or —NR ⁷ R ⁸ . R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group, and R ¹ , R ² , R ³ and R ⁴ may combine with each other to form a ring. Q ¹ , Q ² and Z may be bonded to each other to form a ring. When X and Y represent CR ⁵ , each CR ⁵ may be bonded to form a ring.
The compound represented by general formula (1) is demonstrated below.

Examples of the halogen atom represented by R ¹ , R ² , R ³ and R ⁴ include a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, more preferably a chlorine atom or a bromine atom, Preferably it is a chlorine atom.

Examples of the aliphatic hydrocarbon group represented by R ¹ , R ² , R ³ , and R ⁴ include an alkyl group having 1 to 30 carbon atoms and an alkenyl group having 2 to 30 carbon atoms (here, “alkenyl group”). Preferably means an unsaturated aliphatic group having a double bond including a cycloalkenyl group, a bicycloalkenyl group and the like, or an alkynyl group having 2 to 30 carbon atoms.

The alkyl group when R ¹ , R ² , R ³ , and R ⁴ represent an alkyl group includes a cycloalkyl group, a bicycloalkyl group, a linear alkyl group, and a branched alkyl group.

  Here, as a linear alkyl group or a branched alkyl group, a C1-C30 alkyl group is preferable, More preferably, it is a C1-C10 alkyl group, More preferably, it is C1-C4. It is an alkyl group. More specifically, for example, methyl group, ethyl group, n-propyl group, isopropyl group, tert-butyl group, n-octyl group, eicosyl group, 2-chloroethyl group, 2-cyanoethyl group, trifluoromethyl group, A 2-methoxyethyl group, a 2-hydroxyethyl group, a 3-dimethylaminopropyl group, or a 2-ethylhexyl group can be exemplified.

  As a cycloalkyl group, a C3-C30 cycloalkyl group is preferable, More preferably, it is a C3-C16 cycloalkyl group, More preferably, it is a C5-C8 cycloalkyl group. Specific examples include a cyclohexyl group, a cyclopentyl group, and a 4-n-dodecylcyclohexyl group.

  Examples of the bicycloalkyl group include a 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. A bicycloalkyl group having 5 to 20 carbon atoms is more preferable, and a bicycloalkyl group having 6 to 15 carbon atoms is still more preferable. Examples include a bicyclo [1,2,2] heptan-2-yl group and a bicyclo [2,2,2] octan-3-yl group. The bicycloalkyl group in the present invention includes a tricyclo structure having more ring structures.

  In the substituents described below, when “alkyl group” is described, in the present invention, in addition to a linear alkyl group and a branched alkyl group, monocyclic and polycyclic cycloalkyl groups and bicycloalkyl groups are included.

The alkenyl group when R ¹ , R ² , R ³ , and R ⁴ represent an alkenyl group includes a cycloalkenyl group, a bicycloalkenyl group, a linear alkenyl group, and a branched alkenyl group.

  The straight-chain alkenyl group or branched alkenyl group is preferably an alkenyl group having 2 to 30 carbon atoms, more preferably an alkenyl group having 2 to 15 carbon atoms, and still more preferably an alkenyl group having 2 to 10 carbon atoms. . For example, a vinyl group, an allyl group, a prenyl group, a geranyl group, and an oleyl group can be mentioned.

  The cycloalkenyl group is preferably a C3-C30 cycloalkenyl group, that is, a monovalent group obtained by removing one hydrogen atom of a C3-C30 cycloalkene. More preferably, it is a C3-C16 cycloalkenyl group, More preferably, it is a C5-C10 cycloalkenyl group. Examples include a 2-cyclopenten-1-yl group and a 2-cyclohexen-1-yl group.

  The bicycloalkenyl group is preferably a bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a bicycloalkene having one double bond. A bicycloalkenyl group having 5 to 20 carbon atoms is more preferable, and a bicycloalkenyl group having 6 to 12 carbon atoms is still more preferable. 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 , R ² , R ³ and R ⁴ is preferably an alkynyl group having 2 to 30 carbon atoms, more preferably an alkynyl group having 2 to 20 carbon atoms, still more preferably carbon. It is an alkynyl group having a number of 2 to 10. Examples include ethynyl group and propargyl group.

The aryl group represented by R ¹ , R ² , R ³ and R ⁴ is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 20 carbon atoms, still more preferably carbon. It is an aryl group of several 6-15. Examples include a phenyl group, a p-tolyl group, a naphthyl group, an m-chlorophenyl group, and an o-hexadecanoylaminophenyl group.

Examples of the hetero atom in the heterocyclic group represented by R ¹ , R ² , R ³ , and R ⁴ include oxygen, sulfur, and nitrogen. Oxygen and nitrogen are preferable, and nitrogen is more preferable.
The number of heterocyclic rings is preferably 1 or 2, and the number of members is preferably 5 or 6. They may be further condensed. Further, it may be an aromatic heterocycle or a non-aromatic heterocycle. Specific examples include pyridine, imidazole, furan, thiophene, pyrimidine, quinoline, indole and the like.

As the alkyloxy group represented by R ¹ , R ² , R ³ and R ⁴ , an alkyloxy group having 1 to 20 carbon atoms is preferable, more preferably an alkyloxy group having 1 to 10 carbon atoms, More preferably, it is a C1-C4 alkyloxy group. Specific examples include a methoxy group, an ethoxy group, an n-butoxy group, and a 2-ethylhexyloxy group.

The aryloxycarbonyl group represented by R ¹ , R ² , R ³ , and R ⁴ is preferably an aryloxycarbonyl group having 6 to 20 carbon atoms, more preferably an aryloxycarbonyl group having 6 to 15 carbon atoms. And more preferably an aryloxycarbonyl group having 6 to 10 carbon atoms. Specific examples include a phenyloxycarbonyl group and a 4-nitrophenyloxycarbonyl group.

The acylamino group represented by R ¹ , R ² , R ³ , and R ⁴ is preferably an acylamino group having 1 to 20 carbon atoms, more preferably an acylamino group having 2 to 10 carbon atoms, and still more preferably An acylamino group having 2 to 6 carbon atoms. Specific examples include an acetylamino group, a propionylamino group, and a benzoylamino group.

In the general formula (1), the substituent represented by R ¹ , R ² , R ³ and R ⁴ is preferably an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, or It is a carbamoyl group.

In the general formula (1), the aliphatic hydrocarbon group represented by Q ¹ and Q ² is an aliphatic group represented by R ¹ , R ² , R ³ , and R ⁴ in the general formula (1). It is synonymous with a hydrocarbon group, and its preferable range is also the same.
In general formula (1), the aliphatic hydrocarbon group in Q ¹ and Q ² is preferably an alkyl group having 1 to 5 carbon atoms, and the alkyl group is preferably a methyl, ethyl group or n-propyl group.
Q ¹ and Q ² are particularly preferably hydrogen atoms.

In General Formula (1), X and Y each independently represent a nitrogen atom or CR ⁵ , and Z represents —OR ⁶ or —NR ⁷ R ⁸ .
Here, the aliphatic hydrocarbon group, aryl group and heterocyclic group represented by R ⁵ , R ⁶ , R ⁷ and R ⁸ in general formula (1) are the same as R ¹ in general formula (1), R ^{2, R 3,} and an aliphatic hydrocarbon group represented by R ^4, have the same meaning as the aryl group and heterocyclic group, and preferred ranges are also the same.

X and Y in the general formula (1) are preferably a nitrogen atom or —CH, and more preferably a nitrogen atom.
Z is preferably —OH, —OCH 3, —N (CH 2 CH 2 OH) 2, and more preferably —OH.

In general formula (1), R ¹ , R ² , R ³ and R ⁴ may be bonded to each other to form a ring. Q ¹ , Q ² and Z may be bonded to each other to form a ring. When X and Y represent CR ⁵ , each CR ⁵ may be bonded to form a ring.

  Each substituent in the general formula (1) may further have a substituent. Examples of the substituent that can be introduced include a halogen atom (a fluorine atom, a chloro atom, a bromine atom, or an iodine atom), an alkyl group ( Linear, branched and cyclic alkyl groups, including bicycloalkyl groups), alkenyl groups, alkynyl groups, aryl groups, heterocyclic groups (regardless of where they are substituted), acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups , Heterocyclic oxycarbonyl group, carbamoyl group, N-hydroxycarbamoyl group, N-acylcarbamoyl group, N-sulfonylcarbamoyl group, N-carbamoylcarbamoyl group, thiocarbamoyl group, N-sulfamoylcarbamoyl group, carbazoyl group, carboxy Group or a salt thereof, oxalyl group, oxamoyl group, cyano , Carbonimidoyl group (Carbonimidoyl group), formyl group, hydroxy group, alkoxy group (including groups containing ethyleneoxy group or propyleneoxy group unit), aryloxy group, heterocyclic oxy group, acyloxy group, (alkoxy or Aryloxy) carbonyloxy group, carbamoyloxy group, sulfonyloxy group, amino group, (alkyl, aryl, or heterocyclic) amino group, acylamino group, sulfonamide group, ureido group, thioureido group, N-hydroxyureido group, imide Group, (alkoxy or aryloxy) carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, hydrazino group, ammonio group, oxamoylamino group, N- (alkyl or aryl) sulfo Luureido group, N-acylureido group, N-acylsulfamoylamino group, hydroxyamino group, nitro group, heterocyclic group containing a quaternized nitrogen atom (for example, pyridinio group, imidazolio group, quinolinio group, isoquinolinio group) , Isocyano group, imino group, mercapto group, (alkyl, aryl, or heterocyclic) thio group, (alkyl, aryl, or heterocyclic) dithio group, (alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, A sulfo group or a salt thereof, a sulfamoyl group, an N-acylsulfamoyl group, an N-sulfonylsulfamoyl group or a salt thereof, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, a silyl group, etc. Can be mentioned.

  In a more preferred embodiment, the compound represented by the general formula (1) is a compound represented by the following general formula (1-2).

In the general formula (1-2), X represents a nitrogen atom or CR ^5. R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom, halogen atom, aliphatic hydrocarbon group, aryl group, heterocyclic group, carboxy group, alkyloxy group, aryloxycarbonyl group, carbamoyl A group, an acylamino group, an amino group, or a cyano group, at least one of which represents a substituent other than a hydrogen atom. R ⁶ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. R ⁵ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. R ¹ , R ² , R ³ and R ⁴ may combine with each other to form a ring.

  Moreover, it is a more preferable aspect that the compound represented by General formula (1) is a compound represented by the following general formula (1-3).

In the general formula (1-3), Y represents a nitrogen atom or CR ^5. Q ¹ and Q ² each independently represent a hydrogen atom or an aliphatic hydrocarbon group. R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom, halogen atom, aliphatic hydrocarbon group, aryl group, heterocyclic group, carboxy group, alkyloxy group, aryloxycarbonyl group, carbamoyl A group, an acylamino group, an amino group, or a cyano group, at least one of which represents a linear alkyl group, a branched alkyl group, a cyclic alkyl group, or a carbamoyl group. R ⁵ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. R ¹ , R ² , R ³ and R ⁴ may combine with each other to form a ring. Q ¹ and Q ² may be bonded to each other to form a ring.
In addition, the preferable range of each substituent of R < ¹ >, R < ² >, R < ³ >, R < ⁴ >, X, Y, Q < ¹ > and Q < ² > in general formula (1-2) and general formula (1-3) is general formula ( This is the same as the preferred range of each substituent in 1).

As one embodiment of a more preferable combination of substituents in the general formula (1), at least one of R ¹ , R ² , R ³ and R ⁴ is a linear alkyl group, a branched alkyl group, a cyclic alkyl group or a carbamoyl group An embodiment in which X is a nitrogen atom, Y is a nitrogen atom, Z is —OH, Q ¹ is a hydrogen atom, and Q ² is a hydrogen atom.

In another embodiment of the more preferable combination of the substituents in the general formula (1), R ¹ is a hydrogen atom, a linear alkyl group, a branched alkyl group, a cyclic alkyl group, an aryl group or a heterocyclic group, and R 1 ² is a hydrogen atom, a linear alkyl group, a branched alkyl group, a cyclic alkyl group, an aryl group or a heterocyclic group, R ³ is a hydrogen atom, R ⁴ is a hydrogen atom, and X is a nitrogen atom And Y is a nitrogen atom, Z is —OH, Q ¹ is a hydrogen atom, and Q ² is a hydrogen atom.

  Hereinafter, although the preferable example of a compound represented by General formula (1) in this invention is shown, this invention is not limited to these.

  Among the above exemplary compounds, (I-1), (I-2), (I-7), (I-9), (I-18) and the like are preferable from the viewpoint of scratching after polishing.

The addition amount of the compounds represented by the general formulas (1) to (1-3) is preferably 0.01% by mass or more and 0.2% by mass or less with respect to the total mass of the polishing liquid when used for polishing. 0.05 mass% or more and 0.2 mass% or less is still more preferable. That is, the addition amount of such a corrosion inhibitor is preferably 0.01% by mass or more from the viewpoint of not expanding dishing, and is preferably 0.2% by mass or less from the viewpoint of storage stability.
The compounds represented by the general formulas (1) to (1-3) described above may be used alone or in combination of two or more.

[(D) Specific amine]
The metal polishing slurry of the present invention comprises (d) 2-ethanolamine, 2,3-dihydroxypropylamine, 2-amino-1,3-propanediol, 3 and the compound represented by the general formula (1). -An amine containing an oxygen atom in the molecule selected from the group consisting of amino-1,2-propanediol, morpholine, and bishydroxyethylethylenediamine (hereinafter referred to as a specific amine as appropriate). .
Certain amines usable in the present invention Propelled by one oxygen atom in its molecule, ether oxygen atoms, or has a hydroxy group include those selected from the following group of compounds.
That is, 2-ethanolamine, 2, 3-dihydroxypropyl amine, 2-amino-1,3-propanediol, 3-amino-1,2-propanediol, morpholine, contact and, from the group consisting of bis-hydroxyethyl ethylenediamine Ru amines der selected.

  Among the specific amines, 2-ethanolamine, 2,3-dihydroxypropylamine, 2-amino-1,3-propanediol, or morpholine is more preferable, and 2-amino-1, more preferably 3-propanediol or morpholine.

(D) The addition amount of the specific amine is 0.0001% by mass or more and 10% by mass or less, and more preferably 0.001% by mass or more and 5% by mass with respect to the total mass of the polishing liquid used for polishing. It is below, More preferably, they are 0.01 mass% or more and 1 mass% or less. By setting it as the said range, performance, such as flatness and a scratch, can be improved, maintaining the polishing rate of TEOS and Ta to a desired value.
(D) A specific amine may be used individually by 1 type, and may use 2 or more types together.

[(B) Oxidizing agent]
The metal polishing liquid of the present invention contains a compound (oxidant) that can oxidize a metal to be polished.
Examples of the oxidizing agent include hydrogen peroxide, peroxide, nitrate, iodate, periodate, hypochlorite, chlorite, chlorate, perchlorate, persulfate, Examples thereof include dichromate, permanganate, ozone water, silver (II) salt, and iron (III) salt. Among them, hydrogen peroxide is preferably used.
Examples of the iron (III) salt include iron (III) in addition to inorganic iron (III) salts such as iron nitrate (III), iron chloride (III), iron sulfate (III) and iron bromide (III). Organic complex salts are preferably used.

(B) An oxidizing agent may be used individually by 1 type, and may use 2 or more types together.
The addition amount of the oxidizing agent can be adjusted by the dishing amount at the initial stage of the barrier CMP. When the amount of dishing at the beginning of barrier CMP is large, that is, when it is not desired to polish the wiring material very much in barrier CMP, it is desirable to add a small amount of oxidizer, the dishing amount is sufficiently small, and the wiring material can be removed at high speed. When polishing is desired, it is desirable to increase the addition amount of the oxidizing agent. Thus, since it is desirable to change the addition amount of the oxidizing agent depending on the dishing situation at the initial stage of the barrier CMP, it is preferable that the amount is 0.01 mol to 1 mol in 1 L of the polishing liquid used for polishing. It is especially preferable to set it as 05 mol-0.6 mol.

[(C) Organic acid]
The metal polishing slurry of the present invention contains an organic acid. The organic acid that can be used in the polishing liquid of the present invention is not particularly limited as long as it is an organic compound having at least one carboxyl group in the molecule.
As the compound having a carboxyl group that is an organic acid, a water-soluble compound is desirable, and examples thereof include those exemplified below.
For example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexane 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, phthalic acid, malic acid , Tartaric acid, citric acid, lactic acid, hydroxyethyliminodiacetic acid, iminodiacetic acid, acedamidoiminodiacetic acid, nitrilotripropanoic acid, nitrilotrimethylphosphonic acid and the like.

The organic acid is more preferably a compound represented by the following general formula (2) from the viewpoint of achieving a high polishing rate.
In addition, it is preferable that the number of the carboxyl groups which exist in a molecule | numerator is 1-4, and it is more preferable that it is 1-2 from a viewpoint which can be used cheaply.

In the general formula (2), R ³ and R ⁴ each independently represent a hydrocarbon group, preferably represents a hydrocarbon group having 1 to 10 carbon atoms.
R ³ is a monovalent hydrocarbon group, for example, an alkyl group having 1 to 10 carbon atoms (for example, a methyl group, a cycloalkyl group, etc.), an aryl group (for example, a phenyl group), an alkoxy group, an aryloxy group Groups and the like are preferred.
R ⁴ is a divalent hydrocarbon group, for example, an alkylene group having 1 to 10 carbon atoms (for example, a methylene group, a cycloalkylene group, etc.), an arylene group (for example, a phenylene group), an alkyleneoxy group, or the like. preferable.
The hydrocarbon group represented by R ³ and R ⁴ may further have a substituent. Examples of the substituent that can be introduced include an alkyl group having 1 to 3 carbon atoms, an aryl group, an alkoxy group, and a carboxyl group. Group, etc., and when it has a carboxyl group as a substituent, this compound has a plurality of carboxyl groups.
R ³ and R ⁴ may be bonded to each other to form a cyclic structure.

  Examples of the compound represented by the general formula (2) include 2-furancarboxylic acid, 2,5-furandicarboxylic acid, 3-furancarboxylic acid, 2-tetrahydrofurancarboxylic acid, diglycolic acid, methoxyacetic acid, methoxy Phenylacetic acid, phenoxyacetic acid and the like can be mentioned. Among them, 2,5-furandicarboxylic acid, 2-tetrahydrofurancarboxylic acid, diglycolic acid and methoxyacetic acid are preferable from the viewpoint of polishing the surface to be polished at high speed.

  In the polishing liquid of the present invention, the addition amount of the organic acid is preferably 0.1% by mass or more and 5% by mass or less, and preferably 0.5% by mass or more and 2% by mass with respect to the total mass of the polishing liquid used for polishing. % Or less is more preferable. That is, the content of such an organic acid is preferably 0.1% by mass or more from the viewpoint of achieving a sufficient polishing rate, and is preferably 5% by mass or less from the point of not causing excessive dishing.

  In this invention, it is preferable to use together the compound represented by the following general formula (2) with the compound represented by the said general formula (1).

In general formula (2), X and Y each independently represent a nitrogen atom or CR ⁵ , and R ²¹ , R ²² , R ²³ , and R ²⁴ each independently represent a hydrogen atom, a halogen atom, aliphatic carbonization A hydrogen group, an aryl group, a heterocyclic group, an alkyloxy group, a carboxy group, a carbamoyl group, an acylamino group, an amino group, or a cyano group is represented. R ⁵ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. R ²¹ , R ²² , R ²³ , and R ²⁴ may be bonded to each other to form a ring. When X and Y represent CR ⁵ , each CR ⁵ may be bonded to form a ring. )

Each substituent represented by R ²¹ , R ²² , R ²³ , R ²⁴ , X and Y in the general formula (2) is synonymous with each substituent represented by the general formula (1), and a preferred range Is the same.

  Examples of the compound represented by the general formula (2) include benzotriazole, benzimidazole, and tolyltriazole, and benzotriazole is preferable from the viewpoint of low erosion and dishing.

  In the polishing liquid of the present invention, the amount of the compound represented by the general formula (2) is 0.0001% by mass or more and 10% by mass or less based on the total mass of the polishing liquid when used for polishing. More preferably, it is 0.001 mass% or more and 5 mass% or less, More preferably, it is 0.01 mass% or more and 1 mass% or less. By setting it as the said range, performances, such as flatness and a scratch, can be improved, maintaining the polishing rate of Cu to a desired value.

  The content ratio of the compound represented by the general formula (1) and the compound represented by the general formula (2) in the metal polishing slurry of the present invention is 1: 9 to 9: 1. It is preferably 4: 1 to 1: 4, more preferably 2: 1 to 1: 2. By setting it as the said range, performance, such as flatness and a scratch, can be improved, maintaining the grinding | polishing speed | rate of Cu, TEOS, Ta to a desired value.

[Quaternary ammonium salt]
The metal polishing slurry of the present invention preferably contains a quaternary ammonium salt.
The quaternary ammonium salt in the present invention is not particularly limited as long as it has a structure containing one or two quaternary nitrogens in the molecular structure. Among these, from the viewpoint of achieving sufficient improvement in the polishing rate, a salt represented by the following general formula (A) or general formula (B) is preferable.

In general formula (A) and general formula (B), R ^{1 to} R ⁶ each independently represents an alkyl group having 1 to 20 carbon atoms, an alkenyl group, a cycloalkyl group, an aryl group, or an aralkyl group, Two of R ^{1 to} R ⁶ may be bonded to each other to form a cyclic structure. X represents an alkylene group having 1 to 10 carbon atoms, an alkenylene group, a cycloalkylene group, an arylene group, or a group obtained by combining two or more thereof.

Specific examples of the alkyl group having 1 to 20 carbon atoms as R ^{1 to} R ⁶ 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. Among them, a methyl group, an ethyl group, a propyl group, and a butyl group are preferable.
Moreover, as an alkenyl group as said R < ¹ > -R < ⁶ >, a C2-C10 thing is preferable, and specifically, an ethynyl group, a propyl group, etc. are mentioned.

Specific examples of the cycloalkyl group as R ^{1 to} R ⁶ include a cyclohexyl group and a cyclopentyl group, and among them, a cyclohexyl group is preferable.
Specific examples of the aryl group as R ^{1 to} R ⁶ include a butynyl group, a pentynyl group, a hexynyl group, a phenyl group, and a naphthyl group, and among them, a phenyl group is preferable.
Specific examples of the aralkyl group as R ^{1 to} R ⁶ include a benzyl group, and among them, a benzyl group is preferable.

Each group represented by R ^{1 to} R ⁶ may further have a substituent, and examples of the substituent that can be introduced include a hydroxyl group, an amino group, a carboxyl group, a heterocyclic group, a pyridinium group, and an aminoalkyl. Group, phosphoric acid group, imino group, thiol group, sulfo group, nitro group and the like.

X in the general formula (B) represents an alkylene group having 1 to 10 carbon atoms, an alkenylene group, a cycloalkylene group, an arylene group, or a group obtained by combining two or more of these groups.
In addition to the above organic linking group, the linking group represented by X includes —S—, —S (═O) ₂ —, —O—, —C (═O) — in the chain. May be included.

Specific examples of the alkylene group having 1 to 10 carbon atoms include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, and an octylene group. Among them, an ethylene group, A pentylene group is preferred.
Specific examples of the alkenylene group include an ethynylene group and a propynylene group, and among them, a propynylene group is preferable.
Specific examples of the cycloalkylene group include a cyclohexylene group and a cyclopentylene group. Among them, a cyclohexylene group is preferable.
Specific examples of the arylene group include a phenylene group and a naphthylene group, and among them, a phenylene group is preferable.

  Each of the above linking groups may further have a substituent, and examples of the substituent that can be introduced include a hydroxyl group, an amino group, a sulfonyl group, a carboxyl group, a heterocyclic group, a pyridinium group, an aminoalkyl group, and a phosphate group. , Imino group, thiol group, sulfo group, nitro group and the like.

X ⁻ and 2X ⁻ represent a counter anion (counter anion), and typical anions include nitrate ion, sulfate ion, halide ion (for example, bromide ion, chloride ion, fluoride ion and iodide ion), Citrate ion, phosphate ion, oxalate ion, phthalate ion, maleate ion, gluconate ion, fumarate ion, tartaric acid ion, malate ion, glycolate ion, hydroxide ion, acetate ion, trifluoroacetic acid Ion, borate ion, lactate ion, thiocyanate ion, cyanate ion, sulfate ion, silicate ion, perhalide ion (for example, perbromate ion, perchlorate ion and periodate ion), chromate ion, etc. , P-toluenesulfonate ion, benzenesulfonate ion, Sulfonic acid ions, trifluoromethanesulfonic acid ions, ethanesulfonic acid ions, diglycolic acid ions, 2,5-furancarboxylic acid ions, 2-tetrahydrofurancarboxylic acid ions, tetrafluoroboric acid ions, hexafluorophosphoric acid ions. .

  Among these, from the viewpoint of suppressing corrosion after polishing, the counter anion of the diquaternary ammonium cation is nitrate ion, citrate ion, phosphate ion, oxalate ion, phthalate ion, maleate ion, Fumarate, tartrate, malate, glycolate, hydroxide, acetate, trifluoroacetate, lactate, sulfate, silicate, p-toluenesulfonate, benzenesulfonate, Methanesulfonic acid ion, trifluoromethanesulfonic acid ion, ethanesulfonic acid ion, diglycolic acid ion, 2,5-furancarboxylic acid ion, 2-tetrahydrofurancarboxylic acid ion, boric acid ion, tetrafluoroboric acid ion, hexafluorophosphorus Acid ion is preferred, nitric acid Ions and p-toluenesulfonic acid ions are more preferable.

  Hereinafter, although the specific example [Exemplary compound (A-1)-(A-32)] of the quaternary ammonium salt in this invention is shown, this invention is not limited to these.

  Among the quaternary ammonium salts as described above, A8, A10, A11, and A12 are preferable from the viewpoint of dispersion stability in the polishing liquid.

The quaternary ammonium salt in the present invention can be synthesized, for example, by a substitution reaction in which ammonia, various amines and the like serve as a nucleophile.
Moreover, the purchase as a general sale reagent is also possible.

  The addition amount of the quaternary ammonium salt in the present invention is the polishing liquid used for polishing (that is, the diluted polishing liquid when diluted with water or an aqueous solution. Also referred to as “polishing liquid used for polishing” hereinafter) Is 0.0001% by mass or more and 1% by mass or less, and more preferably 0.001% by mass or more and 0.3% by mass or less. That is, the addition amount of the specific cation is preferably 0.0001% by mass or more from the viewpoint of sufficiently improving the polishing rate, and is preferably 0.3% by mass or less from the viewpoint of sufficient slurry stability.

[Surfactant]
The metal polishing slurry of the present invention preferably further contains an anionic surfactant.
In the polishing liquid of the present invention, by adjusting the type and amount of the surfactant, the polishing rate of the insulating layer can be controlled, dishing and erosion after polishing, and defects can be reduced.

  Examples of the anionic surfactant include carboxylate, sulfonate, sulfate ester, and phosphate ester salt. Examples of carboxylate include soap, N-acyl amino acid salt, polyoxyethylene, or polyoxypropylene alkyl ether. Carboxylate, acylated peptide; as sulfonate, alkylsulfonate, alkylbenzene and alkylnaphthalenesulfonate, naphthalenesulfonate, (alkyl) naphthalenesulfonic acid formalin condensate, (alkyl) naphthalenesulfonic acid formalin condensate , Sulfosuccinate, α-olefin sulfonate, N-acyl sulfonate, alkyl diphenyl ether monosulfonate, alkyl diphenyl ether disulfonate; sulfate ester salts such as sulfated oil, alkyl sulfate, alkyl Ether sulfate, polyoxyethylene or polyoxypropylene alkyl allyl ether sulfate, alkyl amide sulfate; as phosphate ester salt, mention may be made of alkyl phosphate, polyoxyethylene or polyoxypropylene alkyl allyl ether phosphate it can.

  Especially, the compound represented by following General formula (4) is preferable.

R ⁴¹ in the general formula (4) represents a hydrocarbon group, preferably a hydrocarbon group having 6 to 20 carbon atoms.
Specifically, for example, an alkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms (for example, a phenyl group, a naphthyl group, etc.) and the like are preferable. You may have the substituent of.

M ⁺ in the general formula (4) represents a counter cation of sulfonic acid, and is preferably a proton, sodium ion, potassium ion, or ammonium ion.

  Specific examples of the compound represented by the general formula (4) include, for example, decylbenzenesulfonic acid, dodecylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, hexadecylbenzenesulfonic acid, dodecylnaphthalenesulfonic acid, tetradecylnaphthalenesulfonic acid. And the like.

  The total amount of the surfactant added is preferably 0.001 to 10 g, more preferably 0.01 to 5 g in 1 liter of polishing liquid when used for polishing. It is particularly preferable that That is, the addition amount of the surfactant is preferably 0.01 g or more for obtaining a sufficient effect, and preferably 1 g or less from the viewpoint of preventing the CMP rate from being lowered.

[Abrasive]
The metal polishing slurry of the present invention can contain abrasive grains.
Examples of preferable abrasive grains that can be used in the present invention include silicon oxide particles (silica: precipitated silica, fumed silica, colloidal silica, synthetic silica), ceria, alumina, titania, zirconia, germania, manganese oxide, and the like. Among these, silicon oxide particles are preferable, and colloidal silica (particularly, colloidal silica of 20 nm to less than 50 nm) is particularly preferable.
Further, the colloidal silica preferably has an association degree of 3 or less, particularly preferably 3. Here, the degree of association means a value obtained by dividing the diameter of secondary particles formed by aggregation of primary particles by the diameter of primary particles (secondary particle diameter / primary particle diameter). A degree of association of 1 means only monodispersed primary particles. The secondary particle diameter can be measured with an electron microscope or the like.

As a method for producing colloidal silica that can be preferably used as an abrasive, 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 are used. A preparation method in which such a silicon alkoxide compound is hydrolyzed by a sol-gel method is exemplified. The colloid obtained in this way has a very steep 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 is taken. Then, a method of obtaining and calculating the shape and size of each particle is used.

  The average particle size (primary particle size) of the abrasive grains contained in the metal polishing slurry of the present invention is preferably in the range of 20 nm to less than 150 nm, more preferably 20 nm to 50 nm. Particles of 20 nm or more are preferred 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.

  The average particle size (secondary particle size) of the abrasive grains contained in the metal polishing slurry of the present invention is preferably in the range of 30 nm to less than 100 nm, more preferably 40 nm to 80 nm.

  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 metal polishing slurry 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 abrasives made of multiple materials, etc. It is also possible to use it accordingly.

  The addition amount of the abrasive grains in the metal polishing liquid of the present invention is appropriately selected according to the purpose, but generally it is used in the range of 0.001 to 20% by mass with respect to the total mass of the metal polishing liquid. it can.

(PH adjuster)
The polishing liquid of the present invention preferably has a pH of 2.5 to 5.0, more preferably a pH of 3.0 to 4.5. By controlling the pH of the polishing liquid within this range, the polishing rate of the interlayer insulating film can be adjusted more significantly.

In order to adjust the pH to the above preferred range, an alkali / acid or a buffer is used. The polishing liquid of the present invention exhibits an excellent effect when the pH is within this range.
Examples of alkali / acid or buffering agents include non-metallic alkaline agents such as organic ammonium hydroxides such as ammonia, ammonium hydroxide and tetramethylammonium hydroxide, alkanolamines such as diethanolamine, triethanolamine and triisopropanolamine. Alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, inorganic acids such as nitric acid, sulfuric acid and phosphoric acid, carbonates such as sodium carbonate, phosphates such as trisodium phosphate, boric acid Preferable examples include salts, tetraborate and hydroxybenzoate. Particularly preferred alkali agents are ammonium hydroxide, potassium hydroxide, lithium hydroxide and tetramethylammonium hydroxide.

  The addition amount of the alkali / acid or the buffer may be an amount that maintains the pH within a preferable range, and is preferably 0.0001 mol to 1.0 mol in 1 L of the polishing liquid when used for polishing. More preferably, it is 0.003 mol to 0.5 mol.

(Chelating agent)
The metal polishing liquid of the present invention preferably contains a chelating agent (that is, a hard water softening agent) as necessary in order to reduce adverse effects such as mixed polyvalent metal ions.
Chelating agents include general water softeners and related compounds that are calcium and magnesium precipitation inhibitors, such as nitrilotriacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, N, N, N-trimethylenephosphonic acid. , Ethylenediamine-N, N, N ′, N′-tetramethylenesulfonic acid, transcyclohexanediaminetetraacetic acid, 1,2-diaminopropanetetraacetic acid, glycol etherdiaminetetraacetic acid, ethylenediamine orthohydroxyphenylacetic acid, ethylenediamine disuccinic acid ( SS form), N- (2-carboxylateethyl) -L-aspartic acid, β-alanine diacetic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, N , N′-bis (2-hydroxyben Le) ethylenediamine -N, N'-diacetic acid, 1,2-dihydroxy-4,6-disulfonic acid.

Two or more chelating agents may be used in combination as necessary.
The addition amount of the chelating agent may be an amount sufficient to sequester metal ions such as mixed polyvalent metal ions. For example, 0.0003 mol to 0.07 mol in 1 L of a polishing liquid used for polishing. Add to be.

  The metal-polishing liquid of the present invention is generally suitable for polishing a barrier layer made of a barrier metal material for preventing diffusion of copper, which exists between a wiring made of copper metal and / or a copper alloy and an interlayer insulating film. .

[Barrier metal material]
The material constituting the barrier layer to be polished by the metal polishing liquid of the present invention is generally a low-resistance metal material, and TiN, TiW, Ta, TaN, W, and WN are particularly preferable. Is particularly preferred.

[Interlayer insulation film]
As an interlayer insulating film (insulating layer) to be polished by the metal polishing liquid of the present invention, in addition to a commonly used interlayer insulating film such as TEOS, for example, a low dielectric having a relative dielectric constant of about 3.5 to 2.0 An interlayer insulating film including a material having a high rate (for example, an organic polymer system, a SiOC system, a SiOF system, etc., and is generally abbreviated as a low-k film) is used.
Specifically, as a material used for forming a low dielectric constant interlayer insulating film, there are HSG-R7 (Hitachi Chemical Industries), BLACKDIAMOND (Applied Materials, Inc.) and the like in the SiOC system.
The metal polishing slurry of the present invention can also improve the polishing rate of the interlayer insulating film (insulating layer) by the combined use of diquaternary ammonium cations and colloidal silica.

[Raw metal materials]
In the present invention, it is preferable that the object to be polished has a wiring made of copper metal and / or copper alloy as applied to a semiconductor device such as LSI. In particular, a copper alloy is preferable as a raw material for the wiring. Furthermore, the copper alloy containing silver is preferable among copper alloys.
In addition, the silver content contained in the copper alloy is preferably 40% by mass or less, more preferably 10% by mass or less, still more preferably 1% by mass or less, and the silver content is 0.00001 to 0.1% by mass. The most excellent effect is exhibited in the range of copper alloys.

[Wiring thickness]
In the present invention, when the object to be polished is applied to, for example, a DRAM device system, it preferably has a wiring with a half pitch of 0.15 μm or less, more preferably 0.10 μm or less, and further Preferably it is 0.08 micrometer or less.
On the other hand, when the object to be polished is applied to, for example, an MPU device system, it is preferable to have a wiring of 0.12 μm or less, more preferably 0.09 μm or less, and still more preferably 0.07 μm or less.
For the object to be polished having such wiring, the above-described metal polishing liquid in the present invention exhibits particularly excellent effects.

[Polishing method]
The polishing liquid of the present invention is 1. 1. A concentrated liquid which is diluted by adding water or an aqueous solution when used. 2. When each component is prepared in the form of an aqueous solution described in the next section, these are mixed, and if necessary diluted with water to make a working solution. It may be prepared as a working solution.
The polishing liquid in any case can be applied to the polishing method using the polishing liquid of the present invention.
This polishing method is a method in which a polishing liquid is supplied to a polishing pad on a polishing surface plate and brought into contact with a surface to be polished of an object to be polished so that the surface to be polished and the polishing pad move relative to each other.

  As an apparatus used for polishing, a holder for holding an object to be polished (for example, a wafer on which a conductive material film is formed) having a surface to be polished and a polishing pad are attached (a motor capable of changing the number of rotations). Etc.) and a general polishing apparatus having a polishing surface plate. 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 object to be polished does not pop out. The pressing pressure of the object having the surface to be polished (film to be polished) against the polishing pad is preferably 0.68 to 34.5 KPa, the in-plane uniformity of the object to be polished at the polishing rate and the flatness of the pattern In order to satisfy the properties, it is more preferably 3.40 to 20.7 KPa.

During polishing, the polishing liquid is continuously supplied to the polishing pad with a pump or the like.
After the polishing is finished, the object to be polished is thoroughly washed in running water, and then dried after removing water droplets adhering to the object to be polished using a spin dryer or the like.

In the present invention, the 1. When diluting the concentrated solution as in the above method, the following aqueous solutions can be used. The aqueous solution is water containing at least one of an oxidizing agent, an organic acid, an additive, and a surfactant in advance, and the components contained in the aqueous solution and the concentrated solution to be diluted are contained. A component obtained by summing up the component and the component is used as a component of a polishing liquid (use liquid) used for polishing.
Thus, when the concentrate is diluted with an aqueous solution and used, components that are difficult to dissolve can be added later in the form of an aqueous solution, so that a more concentrated concentrate can be prepared.

  In addition, as a method of diluting by adding water or an aqueous solution to the concentrated liquid, the pipe for supplying the concentrated polishing liquid and the pipe for supplying the water or the aqueous solution are joined together and mixed, and mixed and diluted. There is a method of supplying the used liquid to the polishing pad. Mixing of concentrated liquid with water or aqueous solution is a method in which liquids collide with each other through a narrow passage under pressure, filling the pipe with a filler such as a glass tube, and separating and separating the liquid flow. Ordinary methods such as a method of repeatedly performing and a method of providing a blade rotating with power in the pipe can be employed.

  The supply rate of the polishing liquid is preferably 10 to 1000 ml / min, and more preferably 170 to 800 ml / min in order to satisfy the in-surface uniformity of the polishing rate and the flatness of the pattern.

  Further, as a method of polishing while diluting the concentrated liquid with water or an aqueous solution, a pipe for supplying the polishing liquid and a pipe for supplying the water or the aqueous solution are provided independently, and a predetermined amount of liquid is respectively applied to the polishing pad. There is a method of supplying and polishing while mixing by the relative motion of the polishing pad and the surface to be polished. It is also possible to use a method in which a predetermined amount of concentrated liquid and water or an aqueous solution are mixed in one container and then the mixed polishing liquid is supplied to the polishing pad for polishing.

In addition, as another polishing method, the component to be contained in the polishing liquid is divided into at least two components, and when these are used, water or an aqueous solution is added and diluted and supplied to the polishing pad on the polishing platen Then, there is a method in which 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 polishing.
For example, an oxidant is used as the constituent component (a), an organic acid, an additive, a surfactant, and water as the constituent component (b). Component (b) can be used diluted.
Further, an additive having low solubility is divided into two constituent components (a) and (b). For example, an oxidizing agent, an additive, and a surfactant are used as the constituent component (a), and an organic acid, an additive, and a surfactant are used. An agent and water are used as the component (b), and when they are used, water or an aqueous solution is added to dilute the component (a) and the component (b).

In the case of the above example, three pipes for supplying the component (a), the component (b), and water or an aqueous solution are required, and dilution mixing supplies the three pipes to the polishing pad. There is a method of connecting to one pipe and mixing in the pipe. In this case, it is possible to connect two pipes and then connect another pipe. Specifically, this is a method in which a constituent component containing an additive that is difficult to dissolve is mixed with another constituent component, a mixing path is lengthened to ensure a dissolution time, and then a water or aqueous solution pipe is further coupled. .
As described above, the other mixing methods are as follows. The three pipes are directly guided to the polishing pad and mixed by the relative movement of the polishing pad and the surface to be polished, or the three components are mixed in one container. There is a method of supplying diluted polishing liquid to the polishing pad from there.

  In the above polishing method, when one constituent component containing an oxidizing agent is made 40 ° C. or lower and the other constituent components are heated in the range of room temperature to 100 ° C., one constituent component and another constituent component are mixed. Alternatively, when diluting by adding water or an aqueous solution, the liquid temperature can be set to 40 ° C. or lower. This method is a preferable method for increasing the solubility of the raw material having a low solubility of the polishing liquid by utilizing the phenomenon that the solubility becomes high when the temperature is high.

  The raw materials in which the above other components are dissolved by heating in the range of room temperature to 100 ° C. are precipitated in the solution when the temperature is lowered. It is necessary to dissolve the raw material deposited by heating. For this purpose, there are provided means for heating and feeding the other constituents in which the raw material is dissolved, and means for stirring and feeding the liquid containing the precipitate, and heating and dissolving the piping. Can be adopted. When the temperature of one constituent component containing an oxidizing agent is increased to 40 ° C. or higher, the other constituent components that have been heated may be decomposed. When two components are mixed, it is preferable that the temperature be 40 ° C. or lower.

Thus, in the present invention, the components of the polishing liquid may be divided into two or more parts and supplied to the surface to be polished. In this case, it is preferable to divide and supply the component containing an oxidizing agent and the component containing an organic acid. Alternatively, the polishing liquid may be a concentrated liquid and supplied to the surface to be polished separately from the dilution water.
In the present invention, by dividing the components of research Migakueki into two or more divisions, when applying the method of supplying to the surface to be polished, the supply amount is representative of the total amount of supplied from each pipe.

〔pad〕
The polishing pad for polishing applicable to the polishing method of the present invention 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 be one containing abrasive grains generally used for polishing (for example, ceria, silica, alumina, resin, etc.). 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. As the material, non-woven fabric, artificial leather, polyamide, polyurethane, polyester, polycarbonate and the like are preferable. Further, the surface contacting the surface to be polished may be subjected to processing such as lattice grooves / holes / concentric grooves / helical grooves.

[Wafer]
In the present invention, a wafer as an object to be subjected to CMP with the polishing liquid 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.

[Polishing equipment]
An apparatus capable of performing polishing using the polishing liquid of the present invention is not particularly limited, but is mira mesa CMP, reflexion CMP (Applied Materials), FREX200, FREX300 (Ebara Seisakusho), NPS3301, NPS2301 (Nikon), A-FP -310A, A-FP-210A (Tokyo Seimitsu), 2300 TERES (Ram Research), Momentum (Speedfam IPEC), etc. can be mentioned.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1
A polishing liquid having the composition (1) shown below was prepared and a polishing experiment was conducted.
<Composition (1)>
(A) Compound of general formula (1): Exemplified compound (I-2) 0.7 g / L
(D) Specific amine: 2-amino-1,3-propanediol 0.4 g / L
(Manufactured by Tokyo Chemical Industry Co., Ltd.)
・ (C) Organic acid: Diglycolic acid 1g / L
(Wako Pure Chemical Industries, Ltd.)
(B) Oxidizing agent: hydrogen peroxide 10 mL
・ Colloidal silica (C-1) 200g / L
(Secondary particle size: 65 nm, PL3 slurry, manufactured by Fuso Chemical Industries)
-Nitrate of the quaternary ammonium cation (A6) (compound A): 0.2 g / L
・ Pure water is added and the total volume is 1000mL
pH (adjusted with ammonia water and nitric acid) 3.5

(Evaluation method)
The apparatus “LGP-612” manufactured by Lapmaster Co. was used as a polishing apparatus, and each wafer film shown below was polished while supplying slurry under the following conditions.
・ Table rotation speed: 90rpm
-Head rotation speed: 85rpm
Polishing pressure: 13.79 kPa
Polishing pad: Rotex Nitta Co., Ltd. Polotepad
Polishing liquid supply rate: 200 ml / min

<Polishing speed>
As an object to be polished, an 8-inch wafer in which a Ta film and a TEOS film were formed on a Si substrate was used.
The polishing rate was determined by measuring the film thicknesses of the Ta film (barrier layer) and TEOS film (insulating film) before and after CMP and converting from the following equation. The obtained results are shown in Table 1.
Polishing rate (Å / min) = (film thickness before polishing−film thickness after polishing) / polishing time

<Dishing, erosion, scratches and organic residue>
(Polishing object)
As a polishing object, a TEOS (tetraethoxysilane) substrate is patterned by a photolithography process and a reactive ion etching process to form wiring grooves and connection holes having a width of 0.09 to 100 μm and a depth of 600 nm. An 8-inch wafer was used in which a Ta film having a thickness of 20 nm was formed by a tulling method, a copper film having a thickness of 50 nm was subsequently formed by a sputtering method, and then a copper film having a total thickness of 1000 nm was formed by a plating method.

-About dishing and erosion-
Dishing was measured from the step of the line and space part (line 100 μm, space 100 μm) after polishing on the object to be polished. Further, erosion was measured from the step between the field portion and the space portion (line 9 μm, space 1 μm).

-About scratch-
The polishing object was polished to TEOS with the wafer (TEOS film was polished to 50 nm), and then the polished surface was washed with pure water and dried. The dried polished surface was observed with an optical microscope, and scratches were evaluated based on the following evaluation criteria. In addition, evaluation was judged in five steps of the following criteria (AE). The obtained results are shown in Table 1.
"Evaluation criteria"
A: No scratches in question are observed B: 1-2 scratches in question in the wafer surface C: 3-10 scratches in the wafer surface are observed D: Problems in the wafer surface Observe 11 to 50 scratches E: Observe more than 50 scratches in the wafer surface

-About organic residue-
The organic residue was evaluated by observing with an optical microscope by the same method as the scratch evaluation.
"Evaluation criteria"
A: No organic residue in question is observed B: 1-2 organic matter residues in question are observed in the wafer surface C: 3-10 organic residue residues in the wafer surface are observed D: In wafer surface Observe 11 to 50 organic residues in question E: Observe more than 50 organic residues in the wafer surface

(Examples 2 to 4 , 6 to 20, Reference Example 5, and Comparative Examples 1 to 3)
Table 1 shows the compound represented by the general formula (1), the specific amine, the organic acid, the compound represented by the general formula (2), colloidal silica, a quaternary ammonium salt and an anionic surfactant in Example 1. except for changing the compounds and amounts given in the same manner as in example 1, it was adjusted polishing liquid of example 2 4,6 20, reference example 5, and Comparative examples 1 to 3. Further, the polishing rate, dishing, erosion, scratch and organic residue were evaluated in the same manner as in Example 1. The evaluation results are shown in Tables 1 to 3.

  The shape and primary average particle diameter of (C) colloidal silica described in Tables 1 to 3 are shown in Table 4 below. All colloidal silicas listed in Table 4 below are manufactured by Fuso Chemical Industries.

  From the results of Tables 1 to 3, it can be seen that each of the polishing liquids of the examples suppresses dishing, erosion, scratches, and organic residue while maintaining a high polishing rate as compared with the polishing liquids of the comparative examples. .

Claims (12)

(A) a compound represented by the following general formula (1), (b) an oxidizing agent, (c) an organic acid, and (d) 2-ethanolamine. At least one selected from the group consisting of 2,3-dihydroxypropylamine, 2-amino-1,3-propanediol, 3-amino-1,2-propanediol, morpholine, and bishydroxyethylethylenediamine Polishing liquid for metals containing an amine containing an oxygen atom in the molecule.


(In the general formula (1), X and Y each independently represent a nitrogen atom or CR ^5. R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom or an aliphatic group. Represents a hydrocarbon group, an aryl group, a heterocyclic group, a carboxy group, an alkyloxy group, an aryloxycarbonyl group, a carbamoyl group, an acylamino group, an amino group, or a cyano group, Q ¹ and Q ² each independently represent a hydrogen atom Or Z represents —OR ⁶ or —NR ⁷ R ⁸ , and R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represent a hydrogen atom, an aliphatic hydrocarbon group, or an aliphatic hydrocarbon group. Represents a hydrogen group, an aryl group, a heterocyclic group, or a carboxy group, and R ¹ , R ² , R ³ and R ⁴ may be bonded to each other to form a ring, and Q ¹ , Q ² and Z are , Connect with each other If you may form a ring .X and Y represents CR ⁵ and may form a ring by bonding each CR ^5.) The metal polishing slurry according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (1-2).


(In general formula (1-2), X represents a nitrogen atom or CR ^5. R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group, R ⁶ represents an aryl group, a heterocyclic group, a carboxy group, an alkyloxy group, an aryloxycarbonyl group, a carbamoyl group, an acylamino group, an amino group, or a cyano group, at least one of which represents a substituent other than a hydrogen atom. R ⁵ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group, and R ⁵ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, or a carboxy group. ¹ , R ² , R ³ and R ⁴ may combine with each other to form a ring. The metal polishing slurry according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (1-3).


(In general formula (1-3), Y represents a nitrogen atom or CR ^5. Q ¹ and Q ² each independently represents a hydrogen atom or an aliphatic hydrocarbon group. R ¹ , R ² , R ³ , And each R ⁴ independently represents a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, a carboxy group, an alkyloxy group, an aryloxycarbonyl group, a carbamoyl group, an acylamino group, an amino group, or A cyano group, at least one of which represents a linear alkyl group, a branched alkyl group, a cyclic alkyl group, or a carbamoyl group, wherein R ⁵ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic ring; R ¹ , R ² , R ³ and R ⁴ may be bonded to each other to form a ring, and Q ¹ and Q ² are bonded to each other. To form a ring.) In the general formula (1), general formula (1-2) and general formula (1-3), R ¹ and R ² are each independently a hydrogen atom, a linear alkyl group, a branched alkyl group or a cyclic alkyl. The metal polishing slurry according to any one of claims 1 to 3 , which is a group, an aryl group, or a heterocyclic group. Furthermore, the metal polishing liquid of any one of Claims 1-4 containing the compound represented by following General formula (2).


(In General Formula (2), X and Y each independently represent a nitrogen atom or CR ⁵ , and R ²¹ , R ²² , R ²³ , and R ²⁴ each independently represent a hydrogen atom, a halogen atom, or an aliphatic group. Represents a hydrocarbon group, an aryl group, a heterocyclic group, an alkyloxy group, a carboxy group, a carbamoyl group, an acylamino group, an amino group, or a cyano group, and R ⁵ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a hetero group. R ²¹ , R ²² , R ²³ and R ²⁴ may be bonded to each other to form a ring, and when X and Y represent CR ⁵ , CR ⁵ may be bonded to form a ring.) The metal polishing slurry according to claim 5 , wherein the compound represented by the general formula (2) is benzotriazole. A compound represented by the general formula (1), a compound represented by the general formula (2), the content ratio of the metal-polishing liquid, 1: 9 to 9: 5. 1 by weight Or the metal polishing liquid of Claim 6 . The metal polishing slurry according to any one of claims 1 to 7 , further comprising a quaternary ammonium salt. The metal polishing slurry according to any one of claims 1 to 8 , further comprising an anionic surfactant. The metal polishing slurry according to any one of claims 1 to 9 , wherein the pH is 2.5 to 5.0. Furthermore, the metal-polishing liquid of any one of Claims 1-10 containing an abrasive grain.   The metal polishing liquid according to any one of claims 1 to 11 is supplied to a polishing pad on a polishing surface plate, and the polishing surface plate is rotated by rotating the polishing surface plate. A polishing method in which polishing is performed by relative movement while being in contact with a surface to be polished.