JP2007242969A - Polishing liquid for metal, and polishing method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polishing method being, capable of continuously polishing the residual film of a conductor film and a barrier metallic film by the same polishing liquid for a metal in a substrate with an insulating film, the barrier metal film and the conductor film, improving the flatness of a wiring section and the projecting section of the insulating film and capable of reducing a scratch and the polishing liquid for the metal used for the polishing method. <P>SOLUTION: The polishing liquid for the metal is used for the chemical-mechanical polishing of the conductor film consisting of copper or a copper alloy and the barrier metal film in the manufacture of a semiconductor device. The polishing liquid for the metal contains a component (1): a colloidal silica grain component, having a primary grain size of 10 to 35 nm and the degree of association of 5 or less and the component (2): the colloidal silica grain component, having the primary grain size of 50 to 100 nm and the degree of association of 5 or smaller. The polishing liquid for the metal further contains the component (3): an oxidant component and the component (4): an aminocarboxylic acid, having two or more of carboxyl groups. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a metal polishing liquid and a polishing method using the same, and more particularly to a metal polishing liquid used in a wiring process in manufacturing a semiconductor device and a polishing method using the same. In particular, in a chemical mechanical technique applied to copper flattening, it is used for a polishing method capable of polishing at a high speed and continuously polishing a conductor film and a barrier metal film with the same metal polishing liquid. The present invention relates to a metal polishing slurry.

  In recent years, in the development of semiconductor devices typified by semiconductor integrated circuits (hereinafter referred to as “LSI” where appropriate), high-density and high-integration by miniaturization and stacking of wirings for miniaturization and high speed. Is required. For this purpose, various techniques such as chemical mechanical polishing (hereinafter, referred to as “CMP” as appropriate) have been used.

  A general method of CMP is to apply a polishing pad on a circular polishing platen (platen), immerse the polishing pad surface with a metal polishing liquid, press the surface of the substrate (wafer) against the pad, In a state where a predetermined 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.

  A metal polishing solution used in CMP generally contains abrasive grains (eg, alumina, silica) and an oxidizing agent (eg, hydrogen peroxide, persulfuric acid), and oxidizes the metal surface with the oxidizing agent. It is considered that the oxide film is polished by removing with an abrasive.

  However, when CMP is performed using a metal polishing liquid containing such solid abrasive grains, scratches (scratches), a phenomenon in which the entire polished surface is polished more than necessary (thinning), and the polished metal surface is flat In addition, a phenomenon in which only the center is polished deeper to form a dish-like depression (dishing), an insulator between metal wirings is polished more than necessary, and a plurality of wiring metal surface surfaces form dish-shaped recesses. A phenomenon (erosion) may occur.

  In order to solve such problems in the conventional solid abrasive grains, as a metal polishing liquid not containing abrasive grains, for example, for metals consisting of hydrogen peroxide / malic acid / benzotriazole / ammonium polyacrylate and water A polishing liquid and a polishing method are disclosed (for example, refer to Patent Document 1). According to the polishing method described in this document, the metal film on the convex portion of the semiconductor substrate is selectively CMPed, and the metal film is left in the concave portion to obtain a desired conductor pattern, but the conventional solid abrasive grains are included. Since CMP proceeds by friction with a much softer polishing pad than mechanically, there is a problem that it is difficult to obtain a sufficient polishing rate.

  Further, an aqueous dispersion for chemical mechanical polishing containing an organic compound that suppresses deterioration of the polishing pad is disclosed (for example, see Patent Document 2). However, even with this polishing aqueous dispersion, there is concern about the dishing phenomenon in which the wiring portion metal is excessively polished and recessed on the dish.

  In recent years, in order to improve productivity, the diameter of a wafer at the time of manufacturing an LSI has been increased. Currently, a diameter of 200 mm or more is widely used, and manufacturing with a size of 300 mm or more has started. As the size of the wafer increases, a difference in polishing rate between the central portion of the wafer and the peripheral portion tends to occur, and it is important to achieve polishing uniformity.

  On the other hand, as a chemical polishing method having no mechanical polishing means for copper and copper alloys, a method using a chemical dissolution action is known (for example, see Patent Document 3). However, the chemical polishing method using only the chemical dissolution action has a problem with the flatness of the substrate due to the recess shaving, that is, dishing, as compared with CMP in which the metal film of the convex portion is selectively chemically mechanically polished. Will occur.

  Further, when copper wiring is used, a diffusion preventing layer called a barrier layer is generally provided between the wiring portion and the insulating layer in order to prevent copper ions from diffusing into the insulating material. This barrier layer includes one or more layers including one selected from alloys such as TaN, TaSiN, Ta, TiN, Ti, Ru, Nb, Ru, W, WN, Co, Zr, ZrN, and CuTa. It is comprised by the metal film (barrier metal film) which consists of. However, since these barrier layer materials themselves have conductive properties, the barrier layer material on the insulating layer must be completely removed to prevent the occurrence of errors such as leakage current. This is achieved by a method similar to the bulk polishing of the wiring material (this method is sometimes referred to as “barrier CMP”).

  At present, in order to increase the production efficiency of semiconductor device production lines, a metal polishing liquid is used whose conductor film polishing rate is higher than the barrier metal film polishing rate, and the conductor film is formed using the barrier metal film as a stop layer. A two-step process of polishing and subsequently polishing the conductor film and the barrier metal film using a different metal polishing liquid is used. In accordance with this, the optimum process consumable member for each metal polishing liquid is different, and therefore polishing is performed using a plurality of pads.

  However, when the plurality of pads are used, there are many problems such as that process consumable members corresponding to each of the pads are necessary and costly, and that the manufacturing process is complicated and the total processing time is delayed. . Therefore, in order to solve these problems, it is conceivable to perform polishing with one pad. However, polishing a wafer using a plurality of metal polishing liquids with a single pad requires a lot of time and effort depending on the time required for the replacement and preparation of the metal polishing liquid and the cleaning of the pads. The problem is mentioned.

  Therefore, a process (hereinafter referred to as “one-step process”) in which a substrate having an insulating film (interlayer insulating film), a barrier metal film, and a conductor film is continuously polished with the same metal polishing liquid. .)

  If a one-step process is realized, it is possible to speed up the polishing time associated with the reduction in the frequency of replacement of the metal polishing liquid, increase the production efficiency of the semiconductor device manufacturing line, and further require a plurality of polishing apparatuses. In addition to this, many practical merits such as downsizing of the apparatus can be expected. Further, in the current polishing method, since the waste liquid after polishing is in a state where two types of slurry are mixed, it is difficult to process, whereas in one step process, there is one type of metal polishing liquid. Waste liquid treatment becomes simple and can contribute to reduction of environmental burden.

In order to realize the one-step process, it is necessary to match the polishing rate ratio (hereinafter referred to as “selection ratio”) in the conductor film, the barrier metal film, and the insulating film as much as possible.
Further, the obstacle to the realization of the one-step metal polishing liquid is that when the conductor film and the barrier film are polished continuously, there is no so-called stop layer. As a result, scratches occur on the polished surface, causing problems such as deterioration in flatness between the wiring portion and the insulating film convex portion.
Thus, regarding the realization of the one-step process in CMP, no effective technique has been provided yet.
JP 2001-127019 A JP 2001-279231 A JP 49-122432 A

  An object of the present invention made in consideration of the above problems is that a substrate having a conductor film and a barrier metal film can be continuously polished with the same metal polishing liquid, and the polished surface after polishing It is another object of the present invention to provide a polishing method capable of reducing the generation of scratches and a metal-polishing liquid used therefor.

As a result of earnestly examining the problems in the metal polishing liquid used in the one-step process, the present inventor has obtained a conductor film and a barrier metal film by using a metal polishing liquid containing specific polishing particles and an oxidizing agent. It has been found that it is possible to polish continuously with the same metal polishing liquid and that the insulating film can function as a stop layer (stopper layer), thereby completing the present invention.
That is, the means for solving the problems are as follows.

<1> A metal-polishing liquid used for chemical mechanical polishing of a conductor film made of copper or a copper alloy and a barrier metal film in the manufacture of a semiconductor device, the following component (1), component (2), component (3 And a component (4).
Component (1): Colloidal silica particle component having a primary particle diameter of 10 to 35 nm and an association degree of 5 or less Component (2): having a primary particle diameter of 50 to 100 nm and an association degree of 5 or less Colloidal silica particle component (3): Oxidizing agent component (4): Aminocarboxylic acid having two or more carboxyl groups <2> The colloidal silica particles of component (1) and the colloidal silica particles of component (2) are: The metal polishing slurry according to <1>, comprising the same material.
<3> The total amount of the colloidal silica particles of the component (1) and the colloidal silica particles of the component (2) is contained in 0.001 to 0.15% by mass in the metal polishing liquid. The metal polishing slurry according to any one of <1> to <2>.
<4> The mass ratio of the colloidal silica particles of the component (1) is 0.005 to 0.4 relative to the total mass of the colloidal silica particles of the component (1) and the colloidal silica particles of the component (2). The metal polishing slurry according to any one of <1> to <3>, characterized in that:
<5> The oxidizing agent is at least one selected from hydrogen peroxide, nitric acid, potassium iodate, periodic acid, potassium periodate, hypochlorous acid, and ozone water <1 > To <4> The metal polishing slurry according to any one of the above.
<6> A substrate having a barrier metal film formed on the entire surface of an interlayer insulating film having a recess, and a conductor film made of copper or a copper alloy formed so that the recess is buried in the surface of the barrier metal film The conductive film and the barrier metal film are polished using the metal polishing liquid according to any one of <1> to <5> as a surface to be polished. A polishing method characterized by using and polishing continuously.
<7> While supplying the metal polishing liquid to the polishing pad attached on the polishing surface plate, the polishing pad and the substrate are relatively moved while the polishing surface of the substrate is pressed against the polishing pad. The polishing method according to <6>, wherein the surface to be polished is polished.
<8> The polishing method according to <6> or <7>, wherein the pressure when the surface to be polished of the substrate is pressed against a polishing pad is 3.5 kPa to 20 kPa.
<9> The polishing method according to any one of <6> to <8>, wherein the interlayer insulating film is a silicon film or an organic film.
<10> Any one of <6> to <9>, wherein the barrier metal film includes at least one selected from tantalum or a tantalum compound, titanium or a titanium compound, tungsten or a tungsten compound, and ruthenium. Polishing method as described in one.

  According to the present invention, a substrate having a conductor film and a barrier metal film can be continuously polished with the same metal polishing liquid, the flatness of the polished surface after polishing is good, and It is possible to provide a polishing method capable of reducing the generation of scratches and a metal polishing liquid used therefor.

Hereinafter, the present invention will be described in detail.
[Metal polishing liquid]
The metal polishing liquid of the present invention is a metal polishing liquid used for chemical mechanical polishing of a conductor film made of copper or a copper alloy and a barrier metal film in the manufacture of semiconductor devices, and comprises the following component (1), component ( 2), comprising component (3) and component (4).
Component (1): Colloidal silica particle component having a primary particle diameter of 10 to 35 nm and an association degree of 5 or less Component (2): having a primary particle diameter of 50 to 100 nm and an association degree of 5 or less Colloidal silica particle component (3): oxidizing agent component (4): aminocarboxylic acid having two or more carboxyl groups

The metal polishing liquid of the present invention will be described below, but is not limited thereto.
The metal polishing slurry of the present invention contains the component (1), component (2), component (3) and component (4) as essential components, and usually comprises water. The metal polishing slurry of the present invention may further contain other components as desired. Other preferable components include additives such as compounds added as so-called passive film forming agents (heterocyclic compounds, etc.), surfactants and / or hydrophilic polymers, acids, alkalis, buffers, and the like. it can. The respective components (essential components and optional components) contained in the metal polishing liquid may be used alone or in combination of two or more.

In the present invention, the “metal polishing liquid” includes not only a polishing liquid used for polishing (that is, a polishing liquid diluted as necessary) but also a concentrated liquid of the metal polishing liquid. is there.
Further, the metal polishing liquid concentrate means a metal polishing liquid prepared with a higher solute concentration than the metal polishing liquid used for polishing, and when used for polishing, It is diluted with an aqueous solution 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 physical concentration operations such as evaporation are performed. It is used in a different way from the meaning of the general terms involved.

Hereinafter, each component will be described.
<Component (1) and Component (2)>
The metal polishing slurry of the present invention contains component (1) (hereinafter referred to as “first colloidal silica particles” as appropriate) and component (2) (hereinafter referred to as “second colloidal silica particles” as appropriate). These function as abrasive particles (abrasive grains). Component (1) is composed of colloidal silica particles having a primary particle diameter in the range of 10 to 35 nm and an association degree of 5 or less. Component (2) is composed of colloidal silica particles having a primary particle diameter of 50 to 100 nm and an association degree of 5 or less.

-Component (1)-
The primary particle size is a particle size cumulative curve showing the relationship between the particle size of colloidal silica particles and the cumulative frequency obtained by integrating the number of particles having the particle size, and the particle at the point where the cumulative frequency of this curve is 50%. It means the diameter.
The particle size of the colloidal silica particles is determined from the direction in which the particle size can be confirmed after grasping the shape of the whole particle using a photograph taken with an electron microscope (scanning electron microscope S4800 manufactured by Hitachi High-Technologies Corporation). The particle size was determined by measuring the particle size of 100 or more arbitrarily selected particles.

  The metal polishing liquid containing component (1) has a mechanical polishing action on a metal containing copper or a metal containing a barrier metal film as a surface to be polished, and polishing for the same metal while suppressing the occurrence of dishing. The residual film of the conductor film and the barrier metal film can be polished continuously with a liquid. On the other hand, the metal polishing liquid containing the component (2) has a mechanical polishing action on the metal containing copper, which is the surface to be polished, and can polish the surface to be polished roughly.

  Therefore, as described above, by mixing the component (1) and the component (2) and using them as abrasive grains in a metal polishing liquid, a substrate having an insulating film, a barrier metal film and a conductor film can be polished for the same metal. The conductor film and the barrier metal film can be continuously polished with the liquid.

The component (1) of the present invention preferably has an association degree of 5 or less. When the degree of association exceeds 5, it is considered that erosion and scratches occur during polishing with a metal polishing liquid containing colloidal silica particles having this degree of association as abrasive particles.
In the present invention, “colloidal silica particles” means “particles in a colloidal state in a state where silica is dispersed”.

The primary particle diameter of component (1) is preferably in the range of 10 to 35 nm, more preferably in the range of 15 to 35 nm.
When the primary particle diameter of the first colloidal silica particles is less than 10 nm, the polishing rate of the barrier metal film shows a low value. Even when the thickness exceeds 35 nm, the polishing rate of the barrier metal film tends to decrease.
The secondary particle size of component (1) is preferably 20 to 70 nm.
The content of the component (1) is preferably 0.000005 to 0.06% by mass with respect to the total mass of the metal polishing slurry when used, from the viewpoint of reducing the number of defects on the surface to be polished. More preferred is 000007 to 0.04 mass%.

-Component (2)-
The component (2) of the present invention preferably has an association degree of 5 or less. When the degree of association exceeds 5, it is considered that erosion and scratches occur during polishing with a metal polishing liquid containing colloidal silica particles having this degree of association as abrasive particles.
The primary particle size of component (2) is preferably in the range of 50 to 100 nm.
When the primary particle diameter of the component (2) is less than 50 nm, the polishing rate of Cu is remarkably reduced. When the thickness exceeds 100 nm, the polishing rate of Cu shows a high value, but many scratches are generated on the surface of the silicon wafer with the Cu film after polishing.
From the viewpoint of reducing the number of defects on the surface to be polished, the content of component (2) is preferably in the range of 0.000995 to 0.09% by mass with respect to the total mass of the metal polishing slurry when used. The range of 0.001-0.07 mass% is more preferable.

  The primary particle diameter or the secondary particle diameter of each particle is determined by a dynamic light scattering method. Specifically, it can measure using the particle size distribution measuring apparatus (Horiba Ltd. make, LB-500) which employ | adopted the dynamic light-scattering method.

  In addition, the said primary particle diameter or secondary particle diameter in this invention can be measured by said method about the particle | grains of the 1st colloidal silica particle of a component (1), and the 2nd colloidal silica particle of a component (2), respectively. However, even when both are mixed in a metal polishing liquid, the particle size distribution using a photograph taken with an electron microscope (scanning electron microscope S4800 manufactured by Hitachi High-Technologies Corporation) or employing a dynamic light scattering method Each primary particle diameter or secondary particle diameter can be confirmed by a measuring device (manufactured by Horiba, Ltd., LB-500).

  The degree of association means a value obtained by dividing the diameter of secondary particles in which primary particles are aggregated by the diameter of primary particles (secondary particle diameter / primary particle diameter). Here, the degree of association of 1 means only monodispersed primary particles.

  As the colloidal silica particles of component (1) and component (2) in the present invention, precipitated silica, fumed silica, colloidal silica, and synthetic silica are preferable, and colloidal silica or fumed silica from the viewpoint of high polishing rate for copper-containing metals. Is more preferable, and colloidal silica is particularly preferable.

  These particles can be obtained by well-known production methods. As a wet manufacturing method of metal oxide particles, for example, colloidal silica particles are obtained by a method of hydrolyzing metal alkoxide as a starting material. Colloidal silica particles can be produced by dropping methyl silicate at a certain rate to cause hydrolysis, and through a period of grain growth and a period of stopping grain growth by quenching. In addition, colloidal particles are made using alkoxides such as aluminum and titanium. In this case, the rate of hydrolysis is generally faster than when silicon alkoxide is used, which is convenient when producing ultrafine particles.

  Further, as a dry manufacturing method of metal oxide, fumed particles can be obtained by a reaction in which a metal chloride is introduced into an oxyhydrogen flame and the dechlorinated metal is oxidized. Furthermore, the metal or alloy to be contained in the target substance is pulverized into powder, and this is put into an oxygen flame containing a combustion-supporting gas, causing a continuous reaction by the oxidation heat of the metal, and fine A method for obtaining oxide particles has been put into practical use. Particles produced by these combustion methods are amorphized because they experience high heat during the manufacturing process, and generally have a high solid density because there are fewer impurities such as hydroxyl groups inside compared to wet particles. The surface hydroxyl group density is also low.

  The aforementioned nitride can be obtained, for example, by raising the temperature of the oxide together with a reducing agent such as carbon in a nitrogen atmosphere. In this case, it is very important how the temperature distribution in the reactor is made uniform so as not to cause welding between particles while causing the reduction reaction. If the particles contain welded particles, give these powders velocity energy and disperse them by colliding them with the shielding plate. In the case of strong aggregates, disperse them in a solvent to form a slurry. In general, a method is used in which physical energy is applied and dispersed using an apparatus such as a high-pressure homogenizer.

The total content of the first colloidal silica particles of the component (1) and the second colloidal silica particles of the component (2) is preferably in the range of 0.001 to 0.15% by mass, and 0.05 to 0. A range of 1% by mass is more preferable. In order to obtain a sufficient effect for improving the polishing rate and reducing variations in the polishing rate in the wafer surface, 0.001% by mass or more is preferable, and since the polishing rate by CMP is saturated, 0.15% by mass or less is preferable. .
The mass ratio of the first colloidal silica particles in the metal polishing liquid is preferably in the range of 0.005 to 0.4 with respect to the total mass of the first colloidal silica particles and the second colloidal silica particles. The range of 0.05 to 0.1 is more preferable.

<Component (3): Oxidizing agent>
The metal polishing slurry of the present invention contains an oxidizing agent (a compound capable of oxidizing a metal to be polished).
Examples of the oxidizing agent include hydrogen peroxide, peroxide, nitric acid, nitrate, iodate, periodic acid, periodate, hypochlorous acid, hypochlorite, chlorite, and chloric acid. Examples thereof include salts, perchlorates, persulfates, dichromates, permanganates, ozone water, silver (II) salts, and iron (III) salts.

  Examples of the iron (III) salt include, in addition to inorganic iron (III) salts such as iron nitrate (III), iron chloride (III), iron sulfate (III), iron bromide (III), and iron (III) Organic complex salts are preferably used.

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

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

  Among them, hydrogen peroxide, nitric acid, iodate, hypochlorous acid, hypochlorite, chlorate, periodic acid, periodate, persulfate, ozone water, organic complex salt of iron (III) In the case of using an organic complex salt of iron (III), preferred complex-forming compounds are citric acid, tartaric acid, aminopolycarboxylic acid (specifically, ethylenediamine-N, N, N ′, N′-tetraacetic acid, Diethylenetriaminepentaacetic acid, 1,3-diaminopropane-N, N, N ′, N′-tetraacetic acid, ethylenediamine-N, N′-disuccinic acid (racemic), ethylenediaminedisuccinic acid (SS), N- ( 2-carboxylateethyl) -L-aspartic acid, N- (carboxymethyl) -L-aspartic acid, β-alanine diacetic acid, methyliminodiacetic acid, nitrilotriacetic acid, iminodiacetic acid) Can.

  Among the oxidizing agents, hydrogen peroxide, nitric acid, potassium iodate, periodic acid, potassium periodate, hypochlorous acid, ozone water, persulfate, and iron (III) ethylenediamine-N, N, N Most preferred are complexes of ', N'-tetraacetic acid, 1,3-diaminopropane-N, N, N', N'-tetraacetic acid and ethylenediamine disuccinic acid (SS form).

  The addition amount of the oxidizing agent is preferably in the range of 0.003 mol to 8 mol, more preferably in the range of 0.03 mol to 6 mol, per liter of the metal polishing liquid used for polishing. A range of 1 mol to 4 mol is particularly preferable. That is, the addition amount of the oxidizing agent is preferably 0.003 mol or more from the viewpoint of sufficient metal oxidation and ensuring a high CMP rate, and is preferably 8 mol or less from the viewpoint of preventing roughening of the polished surface.

  The oxidizing agent is preferably used by mixing with a composition containing other components other than the oxidizing agent when polishing using the metal polishing liquid. The timing of mixing the oxidizing agent is preferably within 1 hour immediately before using the metal polishing liquid, more preferably within 5 minutes, and particularly preferably immediately before supplying the metal polishing liquid with the polishing apparatus. And mixing within 5 seconds immediately before feeding to the surface to be polished.

<Component (4): Aminocarboxylic acid having two or more carboxyl groups>
The metal-polishing liquid of the present invention contains an aminocarboxylic acid having two or more carboxyl groups that exhibit the action of acceleration of oxidation, pH adjustment, and buffering agent. It is a compound having a structure different from that of an oxidizing agent for oxidizing a metal, and does not include an acid that functions as the aforementioned oxidizing agent.
Examples of the aminocarboxylic acid having two or more carboxyl groups include aminodicarboxylic acid and aminotricarboxylic acid.
The structure of aminodicarboxylic acid can be represented by the following general formula (I).

In the general formula (I), R ¹ represents a single bond, an alkylene group, or a phenylene group. R ² and R ³ each independently represents a hydrogen atom, a halogen atom, a carboxyl group, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, or an aryl group. R ⁴ represents a hydrogen atom, a halogen atom, a carboxyl group, an alkyl group or an acyl group. R ⁵ represents an alkylene group. However, R ⁵ is -CH ₂ - when, R ¹ is an alkylene group or a phenyl group, and / or, R ⁴ is one of a halogen atom, a carboxyl group and an alkyl group.

The alkylene group as R ¹ and R ⁵ in the general formula (I) may be any one of linear, branched and cyclic, and is preferably an alkylene group having 1 to 8 carbon atoms. , Methylene group and ethylene group.
Examples of the substituent that the alkylene group as R ¹ and R ⁵ and the phenylene group as R ¹ may have in general formula (I) include a hydroxyl group and a halogen atom.

The alkyl group as R ² and R ³ in the general formula (I) is preferably an alkyl group having 1 to 8 carbon atoms, and examples thereof include a methyl group and a propyl group.
The cycloalkyl group as R ² and R ³ in the general formula (I) is preferably a cycloalkyl group having 5 to 15 carbon atoms, and examples thereof include a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.
The alkenyl group as R ² and R ³ in the general formula (I) is preferably an alkenyl group having 2 to 9 carbon atoms, and examples thereof include a vinyl group, a propenyl group, and an allyl group.
The alkynyl group as R ² and R ³ in the general formula (I) is preferably an alkynyl group having 2 to 9 carbon atoms, and examples thereof include an ethynyl group, a propynyl group, and a butynyl group.
The aryl group as R ² and R ³ in the general formula (I) is preferably an aryl group having 6 to 15 carbon atoms, and examples thereof include a phenyl group.
The alkylene chain in these groups may have a hetero atom such as an oxygen atom or a sulfur atom.
Examples of the substituent that each group represented by R ² and R ³ in the general formula (I) may have include a hydroxyl group, a halogen atom, and an aromatic ring (preferably an aromatic ring having 3 to 15 carbon atoms). it can.

The alkyl group as R ⁴ in the general formula (I) is preferably an alkyl group having 1 to 8 carbon atoms, and examples thereof include a methyl group and an ethyl group.
The acyl group as R ⁴ in the general formula (I) is preferably an acyl group having 2 to 9 carbon atoms, and examples thereof include a methylcarbonyl group.
The alkylene chain in these groups may have a hetero atom such as an oxygen atom or a sulfur atom.
Examples of the substituent that each group represented by R ⁴ in the general formula (I) may have include a hydroxyl group, an amino group, a halogen atom, and a carboxyl group.

In the general formula (I), R ⁴ is preferably not a hydrogen atom.

  Specific examples of the compound represented by the general formula (I) are shown in Table 1 below by clarifying the functional group in the following general formula (I), but are not limited thereto.

  Next, the structure of aminotricarboxylic acid can be represented by the following general formula (II).

In general formula (II), R ¹ represents a single bond, an alkylene group, or a phenylene group. R ² and R ³ each independently represents a hydrogen atom, a halogen atom, a carboxyl group, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, or an aryl group. R ⁵ represents an alkylene group. R ⁶ represents a single bond, an alkylene group, an alkyleneoxy group or a phenylene group. However, R ⁵ is -CH ₂ - when, R ¹ is an alkylene group or a phenylene group, and / or, R ⁶ is any one of an alkylene group, an alkylene group or a phenylene group.

The alkylene group as R ¹ and R ⁵ in the general formula (II) may be any one of linear, branched and cyclic, preferably an alkylene group having 1 to 8 carbon atoms, , Methylene group and ethylene group.
Examples of the substituent that the alkylene group as R ¹ and R ⁵ and the phenylene group as R ¹ may have in the general formula (II) include a hydroxyl group and a halogen atom.

The alkyl group as R ² and R ³ in the general formula (II) is preferably an alkyl group having 1 to 8 carbon atoms, and examples thereof include a methyl group and a propyl group.
The cycloalkyl group as R ² and R ³ in the general formula (II) is preferably a cycloalkyl group having 5 to 15 carbon atoms, and examples thereof include a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.
The alkenyl group as R ² and R ³ in the general formula (II) is preferably an alkenyl group having 2 to 9 carbon atoms, and examples thereof include a vinyl group, a propenyl group, and an allyl group.
The alkynyl group as R ² and R ³ in the general formula (II) is preferably an alkynyl group having 2 to 9 carbon atoms, and examples thereof include an ethynyl group, a propynyl group, and a butynyl group.
The aryl group as R ² and R ³ in the general formula (II) is preferably an aryl group having 6 to 15 carbon atoms, and examples thereof include a phenyl group.
The alkylene chain in these groups may have a hetero atom such as an oxygen atom or a sulfur atom.
Examples of the substituent that each group represented by R ² and R ³ in formula (II) may have include a hydroxyl group, a halogen atom, and an aromatic ring (preferably an aromatic ring having 3 to 15 carbon atoms). it can.

The alkylene group as R ⁶ in the general formula (II) is preferably an alkylene group having 1 to 8 carbon atoms, and examples thereof include a methylene group and an ethylene group.
The alkyleneoxy group as R ⁶ in the general formula (II) is preferably an alkyleneoxy group having 1 to 8 carbon atoms, and examples thereof include a methyleneoxy group and an ethyleneoxy group.

  Specific examples of the compound represented by the general formula (II) are shown in Table 2 below by clarifying the functional group in the following general formula (II), but are not limited thereto.

  The amount of aminodicarboxylic acid or aminotricarboxylic acid added is preferably 0.0005 to 0.5 mol, preferably 0.005 mol to 0.3 mol, in 1 liter of the metal polishing liquid used for polishing. Is more preferable, and 0.01 mol to 0.1 mol is particularly preferable. That is, 0.5 mol or less is preferable from the viewpoint of suppressing etching, and 0.0005 mol or more is preferable for obtaining a sufficient effect.

<PH of metal polishing liquid>
The pH of the metal polishing slurry of the present invention is 2 or more, preferably in the range of pH 2 to 10, more preferably in the range of pH 3 to 9. In this range, the metal polishing liquid of the present invention exhibits particularly excellent effects. In the polishing, the metal-polishing liquid of the present invention may be in a form containing no water, or may be diluted with water or an aqueous solution. When diluted with water or an aqueous solution, the pH in the present invention represents a value after dilution with water or an aqueous solution.
The pH of the metal polishing liquid in the present invention is determined by the adsorptivity and reactivity to the polishing surface, the solubility of the polishing metal, the electrochemical properties of the surface to be polished, the dissociation state of the compound functional group, the stability as the liquid It can be set in consideration.

  The pH can be adjusted, for example, by adding an acid or an alkali agent described later, and further adding an inorganic acid such as sulfuric acid.

<Other ingredients>
-Heterocyclic compounds-
The metal polishing liquid of the present invention preferably contains at least one heterocyclic compound as a compound that forms a passive film on the metal surface to be polished.

  Here, the “heterocyclic compound” is a compound having a heterocyclic ring containing one or more heteroatoms. A heteroatom means an atom other than a carbon atom and a hydrogen atom. A heterocycle means a cyclic compound having at least one heteroatom. A heteroatom means only those atoms that form part of a heterocyclic ring system, either external to the ring system, separated from the ring system by at least one non-conjugated single bond, Atoms that are part of a further substituent of are not meant.

  A hetero atom is preferably a nitrogen atom, a sulfur atom, an oxygen atom, a selenium atom, a tellurium atom, a phosphorus atom, a silicon atom, and a boron atom, and more preferably a nitrogen atom, a sulfur atom, an oxygen atom, and a selenium atom. And particularly preferably a nitrogen atom, a sulfur atom and an oxygen atom, and most preferably a nitrogen atom and a sulfur atom.

First, the heterocyclic ring that is the mother nucleus is described.
The number of members of the heterocyclic ring of the heterocyclic compound that can be used in the present invention is not particularly limited, and may be a monocyclic compound or a polycyclic compound having a condensed ring. The number of members in the case of a single ring is preferably 3 to 8, more preferably 5 to 7, and particularly preferably 5 and 6. The number of rings in the case of having a condensed ring is preferably 2 to 4, more preferably 2 or 3.

Specific examples of these heterocycles include the following. However, it is not limited to these.
For example, pyrrole ring, thiophene ring, furan ring, pyran ring, thiopyran ring, imidazole ring, pyrazole ring, thiazole ring, isothiazole ring, oxazole ring, isoxazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, pyrrolidine Ring, pyrazolidine ring, imidazolidine ring, isoxazolidine ring, isothiazolidine ring, piperidine ring, piperazine ring, morpholine ring, thiomorpholine ring, chroman ring, thiochroman ring, isochroman ring, isothiochroman ring, indoline ring, isoindoline ring , Pyridine ring, indolizine ring, indole ring, indazole ring, purine ring, quinolidine ring, isoquinoline ring, quinoline ring, naphthyridine ring, phthalazine ring, quinoxaline ring, quinazoline ring, cinnoline ring, pteridine ring, Lysine ring, perimidine ring, phenanthroline ring, carbazole ring, carboline ring, phenazine ring, anti-lysine ring, thiadiazole ring, oxadiazole ring, triazine ring, triazole ring, tetrazole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring Benzothiadiazole ring, benzofuroxan ring, naphthimidazole ring, benzotriazole ring, tetraazaindene ring and the like, more preferably triazole ring and tetrazole ring.

Next, substituents that the heterocyclic ring may have will be described.
In the present invention, when a specific moiety is referred to as a “group”, the moiety may be unsubstituted or substituted with one or more (up to the maximum possible) substituents. Means good. For example, “alkyl group” means a substituted or unsubstituted alkyl group.

Examples of the substituent that the heterocyclic compound may have include the following. However, it is not limited to these.
For example, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group (a linear, branched or cyclic alkyl group, and even a polycyclic alkyl group such as a bicycloalkyl group is active. A methine group), an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group (regardless of the position of substitution), an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a heterocyclic oxycarbonyl group, a carbamoyl group ( Examples of the carbamoyl group having a substituent include an N-hydroxycarbamoyl group, an N-acylcarbamoyl group, an N-sulfonylcarbamoyl group, an N-carbamoylcarbamoyl group, a thiocarbamoyl group, and an N-sulfamoylcarbamoyl group), a carbazoyl group. Carboxy group or a salt thereof, oxalyl group, oxa Yl group, cyano 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 group) Or aryloxy) carbonyloxy group, carbamoyloxy group, sulfonyloxy group, amino group, (alkyl, aryl, or heterocyclic) amino group, acylamino group, sulfonamido group, ureido group, thioureido group, N-hydroxyureido group, Imido 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 (eg, 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 (the sulfamoyl group having a substituent is, for example, an N-acylsulfamoyl group or an N-sulfonylsulfamoyl group) or a salt thereof, a phosphino group, a phosphinyl group, a phosphinyloxy Group, phosphinylamino group, silyl group, etc. The

  Here, “active methine group” means a methine group substituted with two electron-attracting groups. “Electron withdrawing group” means, for example, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkylsulfonyl group, arylsulfonyl group, sulfamoyl group, trifluoromethyl group, cyano group, nitro group, carvone An imidoyl group is meant. Two electron-withdrawing groups may be bonded to each other to form a cyclic structure. The “salt” means a cation such as alkali metal, alkaline earth metal or heavy metal, or an organic cation such as ammonium ion or phosphonium ion.

  Among these, preferred substituents in the heterocyclic compound include, for example, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group (a linear, branched or cyclic alkyl group, and a bicycloalkyl group). Or an active methine group), an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group (regardless of the position of substitution), an acyl group, an alkoxycarbonyl group, an aryl Oxycarbonyl group, heterocyclic oxycarbonyl group, carbamoyl group, N-hydroxycarbamoyl group, N-acylcarbamoyl group, N-sulfonylcarbamoyl group, N-carbamoylcarbamoyl group, thiocarbamoyl group, N-sulfamoylcarbamoyl group, carbazoyl Group, oxalyl group, oxamoyl group, shear Group, carbonimidoyl group, formyl group, hydroxy group, alkoxy group (including groups containing repeating ethyleneoxy group or propyleneoxy group units), aryloxy group, heterocyclic oxy group, acyloxy group, (alkoxy or aryloxy) Carbonyloxy group, carbamoyloxy group, sulfonyloxy group, (alkyl, aryl, or heterocyclic) amino group, acylamino group, sulfonamide group, ureido group, thioureido group, N-hydroxyureido group, imide group, (alkoxy or aryl) Oxy) carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, hydrazino group, ammonio group, oxamoylamino group, N- (alkyl or aryl) sulfonylureido group, N-acy Ureido group, N-acylsulfamoylamino group, hydroxyamino group, nitro group, quaternized heterocyclic group containing 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, sulfo group or a salt thereof Sulfamoyl group, N-acylsulfamoyl group, N-sulfonylsulfamoyl group or a salt thereof, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, silyl group and the like. Here, the active methine group means a methine group substituted with two electron-withdrawing groups, and the electron-withdrawing group here means an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an alkyl group. Examples include a sulfonyl group, an arylsulfonyl group, a sulfamoyl group, a trifluoromethyl group, a cyano group, a nitro group, and a carbonimidoyl group.

  More preferably, for example, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group (a linear, branched or cyclic alkyl group, and a polycyclic alkyl group such as a bicycloalkyl group) And may contain an active methine group), an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group (regarding the position of substitution).

  In addition, two of the above-described substituents can be combined to form a ring (aromatic or non-aromatic hydrocarbon ring or heterocyclic ring. These can be further combined to form a polycyclic fused ring. , Benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring, pyrazine ring, pyrimidine Ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole ring, phenanthridine Ring, acridine ring, phenant Phosphorus ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothiazine ring, phenazine ring, also form mentioned are) is.

Specific examples of the heterocyclic compound that can be particularly preferably used in the present invention include, but are not limited to, the following compounds.
That is, 1,2,3,4-tetrazole, 5-amino-1,2,3,4-tetrazole, 5-methyl-1,2,3,4-tetrazole, 1,2,3-triazole, 4- Amino-1,2,3-triazole, 4,5-diamino-1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, 3,5-diamino- 1,2,4-triazole, benzotriazole, and the like.

  Representative examples of 1,2,3,4-tetrazole, 1,2,3-triazole and 1,2,4-triazole, which are mentioned as heterocyclic compounds that can be particularly preferably used in the present invention, are shown below. Shown in

The (a) 1,2,3,4-tetrazole derivative in the present invention is characterized by having no substituent on the nitrogen atom forming the ring and having a specific substituent at the 5-position.
The (b) 1,2,3-triazole derivative in the present invention is characterized by having no substituent on the nitrogen atom forming the ring and having a specific substituent at the 4-position and / or 5-position. is there.
The (c) 1,2,4-triazole derivative in the present invention is characterized by having no substituent on the nitrogen atom forming the ring and having a specific substituent at the 2-position and / or 5-position. is there.

  The substituent that may be present at the 5-position of tetrazole includes a substituent selected from the group consisting of a sulfo group, an amino group, a carbamoyl group, a carbonamido group, a sulfamoyl group, and a sulfonamido group, or a hydroxy group, a carboxy group, And an alkyl group substituted with at least one substituent selected from the group consisting of a group, a sulfo group, an amino group, a carbamoyl group, a carbonamido group, a sulfamoyl group, and a sulfonamido group. More preferably, it is an alkyl group substituted with at least one substituent selected from the group consisting of a hydroxy group, a carboxy group, a sulfo group, an amino group, and a carbamoyl group. This alkyl group may have other substituents as long as it has at least one of the aforementioned substituents.

  The (a) 1,2,3,4-tetrazole derivative having a substituent at the 5-position of the present invention preferably contains an alkyl group substituted with at least one of a hydroxy group or a carboxy group as a substituent. It is a tetrazole derivative characterized by the following. More preferably, it is a tetrazole derivative characterized by containing an alkyl group substituted with at least one carboxy group as a substituent. For example, 1H-tetrazole-5-acetic acid and 1H-tetrazole-5-succinic acid can be mentioned.

  Examples of the substituent that may be present at the 4-position and / or 5-position of 1,2,3-triazole include a hydroxy group, a carboxy group, a sulfo group, an amino group, a carbamoyl group, a carbonamido group, a sulfamoyl group, and a sulfone group. A substituent selected from the group consisting of an amide group, or at least one substitution selected from the group consisting of a hydroxy group, a carboxy group, a sulfo group, an amino group, a carbamoyl group, a carbonamido group, a sulfamoyl group, and a sulfonamide group An alkyl group or an aryl group substituted with a group can be mentioned.

  More preferably, a substituent selected from the group consisting of a hydroxy group, a carboxy group, a sulfo group and an amino group, or at least one substituent selected from the group consisting of a hydroxy group, a carboxy group, a sulfo group and an amino group A substituted alkyl group. The alkyl group and aryl group may have other substituents as long as they have at least one of the above-described substituents. Moreover, what substituted by either one of 4-position and 5-position of 1,2,3-triazole is more preferable.

  In the (b) 1,2,3-triazole derivative having a substituent at the 4-position and / or 5-position of the present invention, more preferably a substituent selected from the group consisting of a hydroxy group and a carboxy group, or a substitution thereof (B) A 1,2,3-triazole derivative characterized by containing an alkyl group substituted with at least one of the groups as a substituent. More preferred is a (b) 1,2,3-triazole derivative characterized in that it contains at least one carboxy group or an alkyl group substituted with at least one carboxy group as a substituent. For example, 4-carboxy-1H-1,2,3-triazole, 4,5-dicarboxy-1H-1,2,3-triazole, 1H-1,2,3-triazole-4-acetic acid, 4-carboxy- 5-Carboxymethyl-1H-1,2,3-triazole.

  The substituent that may be present at the 3-position and / or 5-position of 1,2,4-triazole was selected from the group consisting of a sulfo group, a carbamoyl group, a carbonamido group, a sulfamoyl group, and a sulfonamido group. An alkyl group or aryl substituted with a substituent, or at least one substituent selected from the group consisting of a hydroxy group, a carboxy group, a sulfo group, an amino group, a carbamoyl group, a carbonamido group, a sulfamoyl group, and a sulfonamido group The group can be mentioned.

  More preferably, it is an alkyl group substituted with at least one substituent selected from the group consisting of a hydroxy group, a carboxy group, a sulfo group and an amino group. The alkyl group and aryl group may have other substituents as long as they have at least one of the above-described substituents. Moreover, what substituted by any one of 3rd-position and 5th-position of 1,2,4-triazole is more preferable.

  In the (c) 1,2,4-triazole derivative having a substituent at the 3-position and / or 5-position of the present invention, more preferably, an alkyl group substituted with at least one of a hydroxy group and a carboxy group is used as a substituent. (C) 1,2,4-triazole derivative characterized by containing. More preferably, (c) 1,2,4-triazole derivative is characterized in that it contains at least one alkyl group substituted with at least one carboxy group as a substituent. For example, 3-carboxy-1,2,4-triazole, 3,5-dicarboxy-1,2,4-triazole, 1,2,4-triazole-3-acetic acid.

(Specific compound examples)
Specific examples of (a) 1,2,3,4-tetrazole derivatives, (b) 1,2,3-triazole derivatives and (c) 1,2,4-triazole derivatives that can be suitably used in the present invention are shown below. Examples are given in (a-1 to a-26, b-1 to b-26, c-1 to c-19), respectively, but the present invention is not limited thereto.

  The heterocyclic compounds used in the present invention may be used alone or in combination of two or more. Moreover, the heterocyclic compound used by this invention can be synthesize | combined according to a conventional method, and may use a commercial item.

  The total amount of the heterocyclic compound used in the present invention is 0.0001 in 1 L of a metal polishing liquid used for polishing (that is, a metal polishing liquid after dilution when diluted with water or an aqueous solution). The range of -1.0 mol is preferable, More preferably, it is the range of 0.0005-0.5 mol, More preferably, it is the range of 0.0005-0.05 mol.

-Surfactant and / or hydrophilic polymer-
The polishing composition of the present invention preferably contains a surfactant and / or a hydrophilic polymer.
As the surfactant and / or the hydrophilic polymer, an acid form is desirable, and in the case of taking a salt structure, ammonium salt, potassium salt, sodium salt and the like can be mentioned, and ammonium salt and potassium salt are particularly preferable.

  Both the surfactant and the hydrophilic polymer have the action of reducing the contact angle to the surface to be polished and the action of promoting uniform polishing. As the surfactant and / or hydrophilic polymer to be used, those selected from the following group are suitable.

  Examples of the anionic surfactant include carboxylate, sulfonate, sulfate ester salt and phosphate ester salt. As the carboxylate salt, soap, N-acyl amino acid salt, polyoxyethylene or polyoxypropylene alkyl ether carboxyl Acid salt, acylated peptide; as sulfonate, alkyl sulfonate, alkyl benzene and alkyl naphthalene sulfonate, naphthalene sulfonate, sulfosuccinate, α-olefin sulfonate, N-acyl sulfonate; sulfate ester Salts include sulfated oil, alkyl sulfates, alkyl ether sulfates, polyoxyethylene or polyoxypropylene alkyl allyl ether sulfates, alkyl amide sulfates; phosphate ester salts such as alkyl phosphates, polyoxyethylene or polyoxy B pyrene alkyl allyl ether phosphate can be exemplified.

As cationic surfactant, aliphatic amine salt, aliphatic quaternary ammonium salt, benzalkonium chloride salt, benzethonium chloride, pyridinium salt, imidazolinium salt; as amphoteric surfactant, carboxybetaine type, sulfobetaine type, Mention may be made of aminocarboxylates, imidazolinium betaines, lecithins, alkylamine oxides.
Nonionic surfactants include ether type, ether ester type, ester type and nitrogen-containing type. Ether type includes polyoxyethylene alkyl and alkylphenyl ether, alkylallyl formaldehyde condensed polyoxyethylene ether, polyoxyethylene poly Examples include oxypropylene block polymer, polyoxyethylene polyoxypropylene alkyl ether, ether ester type, glycerin ester polyoxyethylene ether, sorbitan ester polyoxyethylene ether, sorbitol ester polyoxyethylene ether, ester type, Polyethylene glycol fatty acid ester, glycerin ester, polyglycerin ester, sorbitan ester, propylene glycol ester Le, sucrose esters, nitrogen-containing type, fatty acid alkanolamides, polyoxyethylene fatty acid amides, polyoxyethylene alkyl amide, and the like.
In addition, fluorine surfactants, silicone surfactants, and the like can be given.

  Polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol alkyl ether, polyethylene glycol alkenyl ether, alkyl polyethylene glycol, alkyl polyethylene glycol alkyl ether, alkyl polyethylene glycol alkenyl ether, alkenyl polyethylene glycol, alkenyl polyethylene glycol alkyl ether, alkenyl polyethylene glycol Alkenyl ether, polypropylene glycol alkyl ether, polypropylene glycol alkenyl ether, alkyl polypropylene glycol, alkyl polypropylene glycol alkyl ether, alkyl polypropylene glycol alkenyl ether, alkenyl poly Ethers such as pyrene glycol, alkenyl polypropylene glycol alkyl ether and alkenyl polypropylene glycol alkenyl ether; polysaccharides such as alginic acid, pectic acid, carboxymethylcellulose, curdlan and pullulan; amino acid salts such as glycine ammonium salt and glycine sodium salt; polyaspartic acid , Polyglutamic acid, polylysine, polymalic acid, polymethacrylic acid, polymethacrylic acid ammonium salt, polymethacrylic acid sodium salt, polymaleic acid, polyitaconic acid, polyfumaric acid, poly (p-styrenecarboxylic acid), polyacrylic acid, polyacrylamide, Amino polyacrylamide, polyacrylic acid ammonium salt, polyacrylic acid sodium salt, polyamic acid, polyamic acid ammonia Salts, polycarboxylic acids and salts thereof, such as polyamic acid sodium salt and polyglyoxylic acid; polyvinyl alcohol, vinyl polymers such as polyvinyl pyrrolidone and acrolein and the like.

  However, when the substrate to be applied is a silicon substrate for a semiconductor integrated circuit or the like, contamination by alkali metal, alkaline earth metal, halide, etc. is not desirable, so an acid type is desirable. desirable. This is not the case when the substrate is a glass substrate or the like. Among the above exemplified compounds, polyacrylic acid ammonium salt, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, and polyoxyethylene polyoxypropylene block polymer are more preferable.

The total amount of the surfactant and / or hydrophilic polymer added is preferably 0.001 to 10 g, and preferably 0.01 to 5 g in 1 L of the polishing composition when used for polishing. More preferably, it is 0.02 to 3 g. That is, the addition amount of the surfactant and / or the hydrophilic polymer is preferably 0.001 g or more for obtaining a sufficient effect, and is preferably 10 g or less from the viewpoint of preventing the CMP rate from being lowered. Moreover, as a weight average molecular weight of these surfactant and / or hydrophilic polymer, 500-100000 are preferable, and 2000-50000 are especially preferable.
Only one type of surfactant may be used, two or more types may be used, and different types of surfactants may be used in combination.

-Chelating agents, alkalis, buffering agents-
In the present invention, it is preferable to further add a chelating agent, an alkali, and a buffer. Below, the chelating agent, alkali, and buffering agent which can be used for this invention are demonstrated.

-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 in 1 L of a metal polishing liquid used for polishing. 0.07 mol is added.

-Alkaline agent, buffer agent-
Moreover, the metal polishing liquid of the present invention can contain an alkali agent for pH adjustment and further a buffering agent from the viewpoint of suppressing pH fluctuations, if necessary.

  Alkaline agents and buffering agents include organic ammonium hydroxides such as ammonium hydroxide and tetramethylammonium hydroxide, nonmetallic alkali agents such as alkanolamines such as diethanolamine, triethanolamine, triisopropanolamine, and the like. Alkali metal hydroxides such as sodium, potassium hydroxide and lithium hydroxide, carbonate, phosphate, borate, tetraborate, hydroxybenzoate, glycyl salt, N, N-dimethylglycine salt, leucine Salt, norleucine salt, guanine salt, 3,4-dihydroxyphenylalanine salt, alanine salt, aminobutyrate, 2-amino-2-methyl-1,3-propanediol salt, valine salt, proline salt, trishydroxyaminomethane salt Lysine salt etc. can be used .

Specific examples of the alkali agent and buffer include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, trisodium phosphate, tripotassium phosphate, diphosphate phosphate. Sodium, dipotassium phosphate, sodium borate, potassium borate, sodium tetraborate (borax), potassium tetraborate, sodium o-hydroxybenzoate (sodium salicylate), potassium o-hydroxybenzoate, 5-sulfo Examples include sodium 2-hydroxybenzoate (sodium 5-sulfosalicylate), potassium 5-sulfo-2-hydroxybenzoate (potassium 5-sulfosalicylate), ammonium hydroxide, and the like.
Particularly preferred alkali agents are ammonium hydroxide, potassium hydroxide, lithium hydroxide and tetramethylammonium hydroxide.

  The addition amount of the alkaline agent and the buffering agent may be an amount that can maintain the pH within a preferable range, and is in the range of 0.0001 mol to 1.0 mol in 1 L of the metal polishing liquid used for polishing. It is preferable that the range be 0.003 mol to 0.5 mol.

  In the present invention, the specific gravity of the metal polishing liquid is preferably in the range of 0.8 to 1.5 from the viewpoint of fluidity of the liquid and stability of the polishing performance, and preferably 0.95 to 1.35. The range is particularly preferable.

[Polishing method]
The polishing method of the present invention includes a barrier metal film formed on the entire surface of an interlayer insulating film having a recess, and a conductor film made of copper or a copper alloy formed so that the recess is buried in the surface of the barrier metal film. The conductive film and the barrier metal film are continuously polished using the metal polishing liquid of the present invention. It is characterized by.

  That is, in the polishing method of the present invention, the conductive film formed on the surface other than the concave portion of the insulating film with a single type of metal polishing liquid is chemically and mechanically polished, and then applied to the same metal. A chemical mechanical polishing method using a metal polishing liquid capable of continuously polishing a residual film of a conductor film and a barrier metal film with a polishing liquid, and as the metal polishing liquid, A polishing liquid is used.

  The metal polishing liquid used in the polishing method of the present invention is a concentrated liquid, and when used, it is diluted by adding water to make a working liquid, or each component is mixed in the form of an aqueous solution described later. However, if necessary, it may be diluted by adding water to obtain a working solution, or it may be prepared as a working solution. Although it does not restrict | limit especially as a metal polishing liquid in this invention, Any said aspect is applicable in this invention.

  In the polishing method of the present invention, a metal-polishing liquid is supplied to a polishing pad on a polishing surface plate, and this is brought into contact with the surface to be polished to cause the surface to be polished and the polishing pad to move relative to each other (relatively move). A polishing method for polishing.

  As a polishing apparatus, a general polishing apparatus having a polishing surface plate (with a motor or the like capable of changing the number of rotations) attached with a holder for holding a semiconductor substrate having a surface to be polished and a polishing pad. Can be used.

  As the polishing pad, a general nonwoven fabric, foamed polyurethane, porous fluororesin, or the like can be used, and there is no particular limitation. The polishing pad may be a non-foamed structure pad or a foamed structure pad. The former uses a hard synthetic resin bulk material like a plastic plate for a pad. The latter is further divided into three types: an independent foam (dry foam system), a continuous foam (wet foam system), and a two-layer composite (laminate system), and a two-layer composite (laminate system) is particularly preferable. Foaming may be uniform or non-uniform.

Furthermore, the polishing pad may contain abrasive grains (for example, ceria, silica, alumina, resin, etc.) used for polishing.
In addition, each of the polishing pads may be soft or hard, and either may be used. In the laminated system, it is preferable to use a different hardness for each layer. The material is preferably non-woven fabric, artificial leather, polyamide, polyurethane, polyester, polycarbonate or the like. In addition, the surface contacting the polishing surface may be subjected to processing such as lattice grooves / holes / concentric grooves / helical grooves.

The polishing conditions are not limited, but the linear velocity of the polishing platen is preferably 1 m / s or more.
The pressure (pressing pressure) when a semiconductor substrate having a surface to be polished (film to be polished) is pressed against the polishing pad is preferably 20 kPa or less, and further by a low pressure condition of 13 kPa or less, a high polishing rate. This is more preferable because it is possible to improve the uniformity of the polishing rate within the wafer surface and the flatness of the pattern while maintaining the above.
In addition, when pressing pressure exceeds 20 kPa, flatness may deteriorate.
Further, the lower limit of the pressing pressure is not particularly limited, but is preferably 2.0 kPa or more, and more preferably 3.5 kPa or more.

  During polishing, a polishing liquid for metal is continuously supplied to the polishing pad with a pump or the like. Although the supply amount is not limited, it is preferable that the surface of the polishing pad is always covered with a metal polishing liquid. The semiconductor substrate after polishing is thoroughly washed in running water, and then dried after removing water droplets adhering to the semiconductor substrate using a spin dryer or the like.

  In the polishing method of the present invention, the aqueous solution for diluting the metal polishing liquid is the same as the aqueous solution described below. The aqueous solution is a water containing at least one of an oxidizing agent, an acid, an additive, and a surfactant in advance, and a component obtained by totaling the components contained in the aqueous solution and the components of the metal polishing liquid to be diluted, It becomes the component at the time of grinding | polishing using the metal polishing liquid. When the metal polishing liquid is diluted with an aqueous solution, components that are difficult to dissolve can be blended in the form of an aqueous solution, and a more concentrated metal polishing liquid can be prepared.

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

  The supply rate of the metal polishing liquid is preferably in the range of 10 to 1000 ml / min. In order to satisfy the uniformity of the polishing rate within the wafer surface and the flatness of the pattern, the supply rate is preferably in the range of 170 to 800 ml / min. More preferred.

  As a method of diluting and polishing the concentrated metal polishing liquid with water or an aqueous solution, a pipe for supplying the metal polishing liquid and a pipe for supplying water or an aqueous solution are provided independently, and a predetermined amount of liquid is supplied from each. A method of polishing while supplying to the polishing pad and mixing by the relative motion of the polishing pad and the surface to be polished can be mentioned. Alternatively, it is also possible to apply a method in which a predetermined amount of concentrated metal polishing liquid and water or an aqueous solution are mixed in one container, and then the mixed metal polishing liquid is supplied to the polishing pad to perform polishing. is there.

  In the present invention, the component to be contained in the metal polishing liquid is divided into at least two components, and when they are used, water or an aqueous solution is added and diluted to be supplied to the polishing pad on the polishing platen, 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 can also be used.

For example, an oxidant is one component (A), an acid, an additive, a surfactant, and water are one component (B). The component (B) is diluted before use.
In addition, the low-solubility additive is divided into two components (C) and (D), and the oxidizing agent, additive, and surfactant are one component (C), and the acid, additive, and surfactant And water as one component (D), and when using them, water or an aqueous solution is added to dilute the component (C) and the component (D).

In the case of this example, three pipes for supplying the component (C), the component (D), and water or an aqueous solution are required, and dilution mixing is performed on one pipe that supplies the three pads to the polishing pad. There is a method of combining and mixing in the pipe. In this case, it is also possible to combine two pipes and then connect another pipe.
For example, a constituent component containing an additive that is difficult to dissolve is mixed with another constituent component, a mixing path is lengthened to secure a dissolution time, and then a pipe for water or an aqueous solution is further combined.

  Other mixing methods are as described above, in which the three pipes are each guided directly to the polishing pad and mixed by the relative movement of the polishing pad and the surface to be polished, and the three components are mixed in one container. And a method of supplying the diluted metal polishing liquid to the polishing pad. In the above polishing method, one constituent component containing an oxidizing agent is made 40 ° C. or lower, the other constituent components are heated in the range of room temperature to 100 ° C., and one constituent component and another constituent component or water or an aqueous solution When the mixture is diluted and used, it can be adjusted to 40 ° C. or lower after mixing. Since the solubility increases when the temperature is high, this is a preferable method for increasing the solubility of the raw material having a low solubility in the metal polishing slurry.

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

  In the present invention, as described above, the component of the metal polishing liquid may be divided into two or more parts and supplied to the polishing surface. In this case, it is preferable to divide and supply the component containing an oxidizing agent and the component containing an acid. Alternatively, the metal polishing liquid may be a concentrated liquid, and the diluted water may be separately supplied to the polishing surface.

  As a method for supplying the metal polishing liquid, as described above, when the metal polishing liquid component is divided into two or more parts and supplied to the polishing surface, the metal polishing liquid is used as a concentrate, and dilution water is used. Another distinction is made when supplying to the polishing surface. However, in any of the methods for supplying a metal polishing liquid, in the polishing method of the present invention, after chemical mechanical polishing of a conductor film formed on a convex portion of an insulating film with one type of metal polishing liquid, Subsequently, the remaining film of the conductor film and the barrier metal film can be continuously polished with the same metal polishing liquid.

  The object to be polished by the polishing method of the present invention is a barrier metal film formed on the entire surface of an interlayer insulating film having a recess, and copper or copper formed so that the recess is buried in the surface of the barrier metal film. And a conductor film made of an alloy. This substrate is a semiconductor substrate, and is preferably an LSI having wiring made of copper metal and / or copper alloy, and the wiring is particularly preferably a copper alloy.

  Furthermore, the copper alloy containing silver is preferable among copper alloys. The silver content contained in the copper alloy is preferably 40% by mass or less, more preferably 10% by mass or less, still more preferably 1% by mass or less, and a copper alloy in the range of 0.00001 to 0.1% by mass. The most excellent effect is exhibited.

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

(substrate)
Examples of the substrate used in the present invention include those used in 8-inch and 12-inch semiconductor wafer manufacturing processes or micromachine manufacturing processes. The types include compound semiconductor sapphire substrates used for semiconductor silicon wafers, SOI wafers, semiconductor lasers, and the like. In addition, it is used for the purpose of flattening by forming a wiring pattern on a polymer film substrate.
The target wafer to be subjected to CMP with the metal polishing liquid of the present invention preferably has a diameter of 200 mm or more, particularly preferably 300 mm or more. The effect of the present invention is remarkably exhibited when the thickness is 300 mm or more.

(Interlayer insulation film)
The interlayer insulating film in the present invention preferably has a dielectric constant of 2.6 or less, and examples thereof include a silicon-based film and an organic interlayer insulating film, and particularly doped with carbon. It is preferable to use a silicon-based film.
The thickness of the interlayer insulating film in the present invention can be appropriately adjusted depending on the upper and lower portions of the wiring in the multilayer wiring or between generations (nodes).
As a workpiece to be polished, a conductive material film is formed on a wafer in which a conductive material film is formed on a support substrate, and an interlayer insulating film provided on a wiring formed on the support substrate. Examples of the material of all the stages that require planarization in the semiconductor device manufacturing process, such as a laminated body.

(Barrier metal film)
The barrier metal film is a film (layer) for preventing diffusion of copper between a conductor film (wiring) made of copper or a copper alloy provided on a semiconductor substrate and an interlayer insulating film.
The material of the barrier layer film is preferably a low-resistance metal material, and specifically includes at least one selected from tantalum or a tantalum compound, titanium or a titanium compound, tungsten or a tungsten compound, and ruthenium. It is more preferable that TiN, TiW, Ta, TaN, W, WN, and Ru are included, and Ta and TaN are particularly preferable.
The thickness of the barrier metal film is preferably about 20 to 30 nm.

  Hereinafter, the present invention will be described specifically by way of examples. The present invention is not limited to these examples. The polishing conditions are as follows.

<Preparation of abrasive grains>
Colloidal silica particles were prepared using a general synthesis method of colloidal silica particles obtained from hydrolysis of alkoxysilane. That is, a mixture of normal methyl silicate and an organic solvent was dropped into a solution in which methanol, ammonia, pure water and a dispersant were mixed with stirring at a constant temperature of 50 ° C. or higher to prepare abrasive grains.
In addition, particle size control of the 1st colloidal silica particle of a component (1) and the 2nd colloidal silica particle of a component (2) was controlled by adjusting the stirring speed of particle | grains. Thereafter, the first colloidal silica particles of component (1) and the second colloidal silica particles of component (2) are quenched by adding a large amount of methanol after reaction generation, and replaced with an aqueous solvent by an evaporator as necessary. Preparation of the 1st colloidal silica particle of a component (1) and the 2nd colloidal silica particle of a component (2) was completed.

  As abrasive grains prepared as described above, the first colloidal silica particles are colloidal silica manufactured by Fuso Chemical Co., Ltd., trade names: PL-07 (volume average particle diameter: 7 nm), PL-1 (volume average particle diameter: 15 nm), PL-2 (volume average particle size: 25 nm), PL-3 (volume average particle size: 35 nm), and PL-5 (volume average particle size: 55 nm) were used. Further, as the second colloidal silica particles, colloidal silica manufactured by Fuso Chemical Co., Ltd., trade names: PL-7 (volume average particle size: 70 nm), PL-10 (volume average particle size: 100 nm), PL-20 (volume average particle) (Diameter: 180 nm) was used.

<Polishing conditions>
As a polishing apparatus, an apparatus “LGP-612” manufactured by Lapmaster Co. was used, and polishing was performed under the following conditions. Specifically, while supplying a slurry of a metal polishing liquid to be described later onto a polishing pad of a polishing surface plate of a polishing apparatus, the polishing surface plate and the substrate are relatively moved while being pressed against the polishing pad. To polish the metal film.
Table rotation speed: 64 rpm
-Head rotation speed: 65rpm
・ Polishing pressure: 13 kPa
・ Polishing pad: Product number IC-1400 manufactured by Rodel Nitta Co., Ltd.
・ Slurry supply rate: 200 ml / min

  As a substrate, a silicon oxide film (insulating film) is patterned by a photolithography process and a reactive ion etching process to form wiring grooves and connection holes (recesses) having a width of 0.09 to 100 μm and a depth of 600 nm, Further, a Ta film (barrier metal film) having a thickness of 20 nm is formed by sputtering, and then a copper film having a thickness of 50 nm is formed by sputtering, and then a copper film (conductor film) having a total thickness of 1000 nm is formed by plating. The formed 8-inch wafer was used.

[Evaluation item]
(Polishing speed)
-Copper and Ta films-
The film thickness difference before and after CMP of the copper film and the Ta film as the conductor film and the barrier metal film was calculated from the electric resistance value. The film thickness difference measurement was performed using VR-200 manufactured by Kokusai Denki Alpha Co., Ltd. Specifically, it was measured by polishing rate (nm / min) = [(thickness of copper and Ta film before polishing) − (thickness of copper and Ta film after polishing)] / polishing time.

(Selection ratio)
As a result of the polishing test, the polishing rate of various films and the selection ratio calculated from the polishing rate were calculated. Here, the selection ratio indicates the ratio of the polishing rate of the material in each. A smaller ratio indicates that different films are polished uniformly.

-Insulating film-
The difference in film thickness before and after CMP of the silicon oxide film, which is an insulating film, was calculated from the electric resistance value. The film thickness difference was measured using F20 manufactured by Filmetrics Co., Ltd. Specifically, it was measured by polishing rate (nm / min) = [(thickness of insulating film before polishing) − (thickness of insulating film after polishing)] / polishing time.

(Scratch of copper film and Ta film)
The appearance of each substrate after polishing was visually observed. The evaluation criteria were as follows: ◯: no scratch, Δ: several scratches observed, x: a clearly problematic number of scratches observed.

<Example 1>
-Metal polishing composition-
Heterocyclic compound: 0.01% by mass of benzotriazole
Ingredient (1): PL-1 0.02 mass%
Ingredient (2): PL-10 0.05 mass%
Ingredient (3): Hydrogen peroxide 1% by mass
Component (4): A-1 below 0.8% by mass
pH (adjusted with aqueous ammonia and sulfuric acid) 6.5

  An aqueous solution was prepared so that each component had the above concentration, and the mixture was stirred and dispersed uniformly with a high-speed homogenizer to obtain a metal polishing liquid of Example 1.

  An aqueous solution was prepared so that each component had the above concentration, and stirred with a high-speed homogenizer to uniformly disperse to obtain a metal polishing liquid. In addition, about the 1st colloidal silica particle and the 2nd colloidal silica particle, the particle size of the value shown in Table 3 was selected from the commercially available colloidal silica.

  Using the metal polishing liquid obtained as described above, polishing was performed under the above conditions, and the above items were evaluated. The results are shown in Table 3.

<Examples 2 to 12 and Comparative Examples 1 to 9>
In the same manner as in Example 1, abrasives having particle sizes shown in Table 3 were used to prepare metal polishing liquids, and these were used to perform similar polishing, and the same evaluation was performed. The results are summarized in Table 3. In Comparative Examples 5, 8, and 9, since abrasive grains that are out of the range of component (1) or component (2) are used, the numerical values are shown in parentheses.

As shown in Table 3, when the metal polishing liquid of the example is used, it is possible to obtain a polished surface with good flatness and no generation of scratches while ensuring a constant polishing rate. I understood.
Specifically, it was found that when a polishing liquid containing aminocarboxylic acid is used, the Cu film can be polished at a high polishing rate. On the other hand, it was found that in Comparative Examples 1 to 4 using an organic acid other than aminocarboxylic acid, the polishing rate of the Cu film was lowered.

It was found that the Cu film can be polished at a high polishing rate when the particle size of the component (2) is in the range of 55 to 70 nm. Further, as apparent from Comparative Example 5 and Comparative Example 6, it was confirmed that the polishing rate of the Cu film was extremely reduced when the particle size outside the above range or the second colloidal silica particles were not included. It was.
Further, it was found that the Ta film is efficiently polished when the particle size of the first colloidal silica particles is in the range of 15 to 30 nm. Further, as is clear from Comparative Example 5, Comparative Example 7 and Comparative Example 8, it is found that the Ta film polishing rate decreases when the particle size outside the above range or the first colloidal silica particles are not included. It was.
Furthermore, it was confirmed that the polishing rate of the insulating film can be selectively controlled by changing the particle size of the first colloidal silica particles.
As is clear from Comparative Example 9, when the first colloidal silica particles having a particle size larger than 35 nm were used, the Ta polishing rate showed a relatively high value. When the wafer surface was observed with an optical microscope, it was confirmed that many scratches were generated on the surface.

<Example 13>
A silicon oxide film is patterned on the silicon wafer surface by a photolithography process and a reactive ion etching process to form wiring grooves and connection holes (recesses) having a width of 0.09 to 100 μm and a depth of 600 nm. A Ta film having a thickness of 20 nm is formed by the sputtering method, a copper film having a thickness of 50 nm is subsequently formed by the sputtering method, and then a patterned wafer having a copper film (conductor film) having a total thickness of 1000 nm is formed by the plating method. The surface of the patterned wafer was polished for 120 seconds with the metal polishing liquid of Example 7 using the cut piece.

As a result, the Cu film on the upper surface of the Ta film was removed, and the exposed Ta film was then polished with the same metal polishing liquid.
When the surface of the silicon wafer after polishing was observed with an optical microscope, it was confirmed that the silicon oxide film other than the wiring groove and the Cu film in the wiring groove were exposed, and the Ta film was completely removed. all right.

Claims (10)

A metal-polishing liquid used for chemical mechanical polishing of a conductor film made of copper or a copper alloy and a barrier metal film in the manufacture of semiconductor devices, comprising the following component (1), component (2), component (3) and component (4) The metal polishing liquid characterized by including.
Component (1): Colloidal silica particle component having a primary particle diameter of 10 to 35 nm and an association degree of 5 or less Component (2): having a primary particle diameter of 50 to 100 nm and an association degree of 5 or less Colloidal silica particle component (3): oxidizing agent component (4): aminocarboxylic acid having two or more carboxyl groups   The metal polishing slurry according to claim 1, wherein the colloidal silica particles of the component (1) and the colloidal silica particles of the component (2) are made of the same material.   The total amount of the colloidal silica particles of the component (1) and the colloidal silica particles of the component (2) is contained in 0.001 to 0.15% by mass in the metal polishing liquid. The metal polishing slurry according to any one of claims 2 to 3.   The mass ratio of the colloidal silica particles of the component (1) is 0.005 to 0.4 based on the total mass of the colloidal silica particles of the component (1) and the colloidal silica particles of the component (2). The metal polishing slurry according to any one of claims 1 to 3, wherein   The oxidizing agent is at least one selected from hydrogen peroxide, nitric acid, potassium iodate, periodic acid, potassium periodate, hypochlorous acid, and ozone water. Item 5. The metal polishing slurry according to any one of items 4 to 4.   A substrate having a barrier metal film formed over the entire surface of the interlayer insulating film having a recess, and a conductor film made of copper or a copper alloy formed so that the recess is buried in the surface of the barrier metal film, A method for polishing a surface on a conductor film side as a surface to be polished, wherein the conductor film and the barrier metal film are continuously formed using the metal polishing liquid according to any one of claims 1 to 5. Polishing method characterized by performing polishing.   While supplying the metal polishing liquid to the polishing pad affixed on the polishing surface plate, the polishing pad and the substrate are relatively moved while the polishing surface of the substrate is pressed against the polishing pad. The polishing method according to claim 6, wherein the polishing surface is polished.   The polishing method according to claim 6 or 7, wherein a pressure when the surface to be polished of the substrate is pressed against a polishing pad is 3.5 kPa to 20 kPa.   The polishing method according to any one of claims 6 to 8, wherein the interlayer insulating film is a silicon-based film or an organic-based film.   The said barrier metal film contains at least 1 sort (s) chosen from a tantalum or a tantalum compound, titanium or a titanium compound, tungsten or a tungsten compound, and ruthenium, The any one of Claim 6 thru | or 9 characterized by the above-mentioned. Polishing method.