KR102405560B1 - Polishing solution, method for producing polishing solution, polishing solution stock solution, polishing solution stock solution containing body, and chemical mechanical polishing method - Google Patents

Abstract

An object of the present invention is to provide a polishing liquid that is less prone to dishing and defects on the surface to be polished when applied to CMP of an object to be polished including a cobalt-containing layer. Another object of the present invention is to provide a method for producing a polishing liquid, a polishing liquid stock solution, a polishing liquid stock solution container, and a chemical mechanical polishing method.
The polishing liquid of the present invention is a polishing liquid for chemical mechanical polishing containing colloidal silica having association degrees 1 to 3, an organic acid, an azole compound, and hydrogen peroxide, and the polishing liquid and the cobalt substrate are in contact for 24 hours. When made, a reaction layer with a thickness of 0.5 to 20 nm containing cobalt atoms is formed on the cobalt substrate.

Description

Polishing liquid, polishing liquid manufacturing method, polishing liquid undiluted solution, polishing liquid undiluted solution receiver, chemical mechanical polishing method

The present invention relates to a polishing liquid, a method for producing a polishing liquid, a polishing liquid stock solution, a polishing liquid stock solution container, and a chemical mechanical polishing method.

In the manufacture of a large-scale integrated circuit (LSI), a chemical mechanical polishing (CMP) method is used for planarization of a bare wafer, planarization of an interlayer insulating film, formation of a metal plug, and formation of buried wiring. is becoming

As a polishing liquid used for CMP, for example, Patent Document 1 describes "a polishing liquid characterized in that a reaction layer having a thickness of 100 nm or more is formed on a surface to be polished in contact with the polishing liquid for 24 hours".

Patent Document 1: Japanese Patent Laid-Open No. 2004-123931

By the way, in recent years, with the request|requirement of miniaturization of a wiring, cobalt attracts attention as a wiring metal element replacing copper.

The present inventors prepared a polishing liquid containing colloidal silica as abrasive grains with reference to Patent Document 1 and studied the properties thereof. As a result, in CMP using a cobalt-containing layer made of cobalt or an alloy thereof as an object to be polished When this polishing liquid was applied, it was discovered that dishing is easy to generate|occur|produce on the to-be-polished surface of a to-be-polished object. In addition, it was found that many defects due to surface roughness such as scratches and partial corrosion occur on the polished surface of the object to be polished.

Accordingly, an object of the present invention is to provide a polishing liquid that is less prone to dishing and defects on the surface to be polished when applied to CMP of an object to be polished including a cobalt-containing layer.

Another object of the present invention is to provide a method for producing a polishing liquid, a polishing liquid undiluted solution, a polishing liquid undiluted solution container, and a chemical mechanical polishing method.

MEANS TO SOLVE THE PROBLEM The present inventors found that the said subject could be solved by the polishing liquid which contains a predetermined component and can form a reaction layer of predetermined thickness when made to contact with a cobalt substrate, as a result of earnestly examining in order to achieve the said subject. Thus, the present invention was completed.

That is, it discovered that the said subject could be achieved with the following structures.

[1] Colloidal silica of the association diagrams 1-3;

organic acids,

an azole-based compound;

A polishing liquid containing hydrogen peroxide and used for chemical mechanical polishing of a cobalt-containing layer, comprising:

A polishing liquid, wherein when the polishing liquid and the cobalt substrate are brought into contact for 24 hours, a reaction layer having a thickness of 0.5 to 20 nm containing cobalt atoms is formed on the cobalt substrate.

[2] The content of colloidal silica in the association degrees 1 to 3 is 0.01 to 1 mass % with respect to the total mass of the polishing liquid,

As said organic acid, it contains an amino acid,

As the azole-based compound, it contains a benzotriazole-based compound and an azole-based compound different from the benzotriazole-based compound,

a pH of 6.5 to 8.0;

When the polishing liquid is in contact with a barrier substrate made of any one metal selected from the group consisting of Ta, TaN, Ti, TiN, Ru, and Mn for 24 hours, the barrier substrate contains atoms of the metal The polishing liquid according to [1], wherein a reaction layer having a thickness of 0.01 to 5 nm is formed.

[3] The polishing liquid according to [2], wherein the polishing rate ratio R1 calculated from the following formula (3) is 250 to 2500.

Equation (3):

R1 = polishing rate of the cobalt substrate by the polishing liquid / polishing rate of the barrier substrate by the polishing liquid

[4] The content of colloidal silica in the association degrees 1 to 3 is 0.5 to 5 mass % with respect to the total mass of the polishing liquid,

As the azole-based compound, it contains a benzotriazole-based compound and an azole-based compound different from the benzotriazole-based compound,

The pH is 8.0 to 10.5,

When the polishing liquid is in contact with a barrier substrate made of any one metal selected from the group consisting of Ta, TaN, Ti, TiN, Ru, and Mn for 24 hours, the barrier substrate contains atoms of the metal A reaction layer with a thickness of 0.01 to 5 nm is formed,

When the polishing liquid and the insulating film substrate made of any one inorganic component selected from the group consisting of SiOx and SiOC are in contact for 24 hours, a reaction layer with a thickness of 0.01 to 10 nm containing silicon atoms is formed on the insulating film substrate , the polishing liquid according to [1].

[5] The organic acid is maleic acid, fumaric acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, phthalic acid, isophthalic acid, terephthalic acid, hemimellitic acid, trimellitic acid, trimesic acid, melo at least one selected from the group consisting of panic acid, prenitic acid, pyromellitic acid, mellitic acid, diphenic acid, citric acid, succinic acid, malic acid, malonic acid, and anthranilic acid,

The polishing liquid according to [4], wherein the content of the organic acid is 0.01 to 0.3 mass % with respect to the total mass of the polishing liquid.

[6] The polishing liquid according to [4] or [5], wherein the polishing rate ratio R2 calculated from the following formula (4) is 0.01 to 2.0, and the polishing rate ratio R3 calculated from the following formula (5) is 0.05 to 2.0, .

Equation (4):

R2 = polishing rate of the cobalt substrate by the polishing liquid / polishing rate of the barrier substrate by the polishing liquid

Equation (5):

R3 = polishing rate of the cobalt substrate by the polishing liquid / polishing rate of the insulating film substrate by the polishing liquid

[7] The polishing liquid according to any one of [1] to [6], wherein the hydrogen peroxide content is 0.001 to 5% by mass.

[8] further containing a metal impurity containing a metal atom;

The metal impurity contains at least one specific metal atom selected from the group consisting of an Fe atom, a Cu atom, an Ag atom, and a Zn atom,

When the specific metal atom is one selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms, the content of the specific metal atoms is 0.01 to 100 mass ppb with respect to the total mass of the polishing liquid,

When the specific metal atoms are at least two types selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms, the content of each specific metal atom is 0.01 to 100 mass ppb with respect to the total mass of the polishing liquid, The polishing liquid according to any one of [1] to [7].

[9] The metal impurity contains metal particles containing at least one specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms;

When the specific metal atom contained in the metal particle is one selected from the group consisting of an Fe atom, a Cu atom, an Ag atom, and a Zn atom, the content of the specific metal atom contained in the metal particle is the total mass of the polishing liquid 0.01 to 50 mass ppb with respect to

When the specific metal atoms contained in the metal particles are two or more selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms, the content of each specific metal atom contained in the metal particles is determined by polishing The polishing liquid according to [8], wherein the amount is 0.01 to 50 mass ppb based on the total mass of the liquid.

[10] The polishing liquid according to [8] or [9], wherein the content ratio T1 calculated from the following formula (1) is 30000 to 500000.

Formula (1): T1 = content of hydrogen peroxide / total content of specific metal atoms selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms contained in the metal impurities

[11] [1] to [10] further containing a compound represented by the general formula (1) described later, wherein the compound represented by the general formula (1) is 0.00001 to 1000 mass ppb with respect to the total mass of the polishing liquid The polishing liquid as described in any one of.

[12] The polishing liquid according to any one of [1] to [11], further comprising an organic solvent, wherein the content of the organic solvent is 0.01 to 20 mass% with respect to the total mass of the polishing liquid.

[13] N-cocoyl sarcosinate, N-lauroyl sarcosinate, N-stearoyl sarcosinate, N-oleoyl sarcosinate, N-myristoyl sarcosinate, N-lauroyl glycine, N -Myristoylglycine, N-palmitoylglycine, N-lauroylglutamic acid, N-cocoylglutamic acid, N-cocoylglutamic acid potassium, N-lauroyl sarcosinate potassium, N-lauroylalaninate, N - Myristoyl alanate and at least one compound selected from the group consisting of N-cocoyl alaninate potassium is further contained, and the total content of the compound is 0.001 to 5 mass % with respect to the total mass of the polishing liquid. , The polishing liquid according to any one of [1] to [12].

[14] The azole-based compound, containing at least one selected from the group consisting of a benzotriazole-based compound, a 1,2,4-triazole-based compound, a pyrazole-based compound, and an imidazole-based compound; The polishing liquid according to any one of [2] to [13].

[15] Any one of [1] to [14], wherein the ratio T2 of the average particle diameter before and after chemical mechanical polishing calculated from the following formula (2) of the colloidal silica of the association degrees 1 to 3 is 1 to 5 The polishing liquid described in .

Equation (2):

T2 = average particle diameter after chemical mechanical polishing/average particle diameter before chemical mechanical polishing

[16] Polishing according to any one of [1] to [15] by mixing water with a polishing liquid stock solution containing colloidal silica of association degrees 1 to 3, an organic acid, an azole compound, and hydrogen peroxide A method for producing a polishing liquid, comprising a dilution step of obtaining a liquid.

[17] containing colloidal silica of association degrees 1 to 3, an organic acid, an azole compound, and hydrogen peroxide;

A undiluted polishing liquid used after diluting 2 to 50 times to prepare the polishing liquid according to any one of [1] to [15].

[18] The stock solution of [17], wherein the pH change before and after dilution is 0.01 to less than 1 when diluted 2 to 50 times with water.

[19] A polishing liquid undiluted solution container comprising: the polishing liquid stock solution according to [17] or [18]; and a container made of an iron-free metal material for containing the polishing liquid stock solution.

[20] While supplying the polishing liquid according to any one of [1] to [15] to a polishing pad mounted on a polishing platen, the polished surface of the object to be polished is brought into contact with the polishing pad, A chemical mechanical polishing method comprising: a polishing body; and a step of polishing the polished surface by relatively moving the polishing pad to obtain a polished target object.

[21] The chemical mechanical polishing method according to [20], wherein the object to be polished contains a cobalt-containing layer comprising at least one selected from the group consisting of cobalt and a cobalt alloy.

ADVANTAGE OF THE INVENTION According to this invention, when applied to the CMP of a to-be-polished object containing a cobalt-containing layer, it is possible to provide the polishing liquid which dishing and a defect do not easily generate|occur|produce on the to-be-polished surface.

Further, according to the present invention, it is possible to provide a method for producing a polishing liquid, a polishing liquid undiluted solution, a polishing liquid undiluted solution container, and a chemical mechanical polishing method.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of a to-be-polished object.
Fig. 2 is a cross-sectional view of the object to be polished after the first polishing is performed.
Fig. 3 is a cross-sectional view of the object to be polished after further second polishing is performed.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail based on embodiment.

In addition, description of the structural element described below is made based on embodiment of this invention, and this invention is not limited to such embodiment.

In addition, in this specification, the numerical range shown using "-" means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

[Abrasive Fluid]

The polishing liquid of the present invention contains colloidal silica having association degrees 1 to 3, an organic acid, an azole compound, and hydrogen peroxide, and is a polishing liquid used for chemical mechanical polishing of a cobalt-containing layer, the polishing liquid and It is a polishing liquid in which a 0.5-20 nm-thick reaction layer containing cobalt atoms (hereinafter also referred to as "reaction layer 1") is formed on the cobalt substrate when the cobalt substrate is brought into contact for 24 hours.

As one of the characteristics of the polishing liquid, when the polishing liquid and the cobalt substrate are brought into contact for 24 hours, a reaction layer having a thickness of 0.5 to 20 nm containing cobalt atoms is formed on the cobalt substrate.

The thickness of the reaction layer is 0.5 nm or more, preferably 2 nm or more. Moreover, the thickness of the said reaction layer is 20 nm or less, 15 nm or less is preferable, and 10 nm or less is more preferable. When the thickness of the reaction layer is less than 0.5 nm, it is difficult to obtain a sufficient polishing rate.

On the other hand, when the thickness of the reaction layer is more than 20 nm, dishing tends to occur on the surface to be polished. The polishing liquid contains colloidal silica in order to improve the polishing rate. Since colloidal silica comes into contact with the reaction layer during CMP and grinds the reaction layer, in the case of a polishing liquid that generates a reaction layer exceeding 20 nm under predetermined conditions, the surface to be polished is abrasive than intended, and dishing is difficult. is presumed to occur.

Moreover, when the association|aggregation degree of colloidal silica exceeds 3, it will become easy to generate|occur|produce a defect in the to-be-polished surface, and it will become easy to generate|occur|produce also dishing. In colloidal silica having an association degree of more than 3, since the particle shape is deformed compared to colloidal silica having association degrees 1 to 3, the contact area of the particles to the surface to be polished is small, and it is close to point contact. For this reason, it is estimated that the surface roughness of the to-be-polished surface becomes coarse and a defect generate|occur|produces. Moreover, even when the thickness of the reaction layer is thin, it has been confirmed that dishing is likely to occur on the surface to be polished when abrasive with colloidal silica having a degree of association exceeding 3 is used.

In addition, the organic acid and the azole compound contained in the polishing liquid contribute to the formation of the above-mentioned reaction layer, and, in addition to contributing to the formation of the above-mentioned reaction layer, ionized metals (various metal ions including cobalt ions) and the colloidal that have been scraped off in the process of CMP. It is estimated that it also contributes to suppressing bonding with silica. When the ionized material of the metal and the colloidal silica are combined, the particle size of the colloidal silica increases, dishing is more likely to occur on the surface to be polished, and defects are also likely to occur.

The reaction layer in the present specification refers to a cobalt substrate (substrate made of cobalt) having a surface to be polished of 10 mm × 10 mm, immersed in 10 mL of a polishing liquid, and the cobalt substrate and the polishing liquid are brought into contact at 25° C. for 24 hours. In this case, a reaction layer formed on the to-be-polished surface of a cobalt substrate is intended. In addition, when immersing a cobalt substrate in a polishing liquid, the form which immersed the laminated body which laminated|stacked the cobalt substrate and another board|substrate (for example, a silicon substrate) in a polishing liquid may be sufficient.

The reaction layer contains cobalt atoms. The reaction layer may further contain an oxygen atom or the like, and it is preferable that the surface of the reaction layer contains a complex of a component in the polishing liquid.

Here, the thickness of the reaction layer is determined by the method described in Examples using a scanning electron microscope (SEM) of the cross-section of the cobalt substrate after contacting the polishing liquid and the cobalt substrate for 24 hours. The thickness obtained by observation is intended.

[pH]

The pH of the polishing liquid is not particularly limited, but is usually preferably 1.0 to 14.0.

As will be described later, the polishing liquid is suitably used for CMP performed for planarization of buried wirings (cobalt wirings) or the like in the manufacture of semiconductor integrated circuit devices.

For example, the polishing liquid is suitably used for CMP of an object to be polished having an insulating film layer, a barrier layer, and a cobalt-containing layer. The object to be polished is usually an insulating film layer having convex portions and concave portions, a barrier layer covering the insulating film layer along the unevenness of the surface of the insulating film layer, and cobalt and an alloy thereof covering the barrier layer so as to fill the recesses of the insulating film layer It has a cobalt-containing layer which consists of at least 1 sort(s) selected from the group which consists of. An example of the said to-be-polished object is shown in FIG. The object to be polished 10 includes a substrate 12, an insulating film layer 14 having a concave portion arranged on the substrate 12, a barrier layer 16 arranged to follow the surface of the insulating film layer 14, It has a cobalt-containing layer 18 disposed so as to fill the recesses of the insulating film layer 14 and cover the barrier layer 16 .

The object to be polished is usually polished in two steps. Specifically, as shown in FIG. 2 , the first polishing of the cobalt-containing layer 18 is polished until the barrier layer 16 is exposed, and as shown in FIG. 3 , when the insulating film layer 14 is exposed The second polishing of polishing the cobalt-containing layer 18 and the barrier layer 16 is performed until the The polishing liquid can be suitably applied to any of the first polishing and the second polishing.

When the polishing liquid is applied to the first polishing, the pH of the polishing liquid is more preferably 6.5 to 8.0. When the pH is in the range of 6.5 to 8.0, when the polishing liquid is applied to CMP, it is easy to adjust the thickness of the reaction layer under predetermined conditions to a desired range, so that dishing is more difficult to occur. From the point where generation|occurrence|production of dishing is suppressed more, it is preferable that pH exists in the range of 6.8-7.8, and it is more preferable especially that it exists in the range of 6.8-7.2. Moreover, the polishing wound, which is one of the defects, is strongly influenced by the state of the surface to be polished and the type of organic acid contained in the polishing liquid. When the polishing liquid is applied to the first polishing, the polishing liquid preferably contains an amino acid as an organic acid as described later, and the polishing liquid containing the amino acid significantly suppresses polishing scratches when the pH is 6.5 or higher. It can be done, and it is confirmed that generation|occurrence|production of a defect is suppressed more.

When the polishing liquid is applied to the second polishing, the pH of the polishing liquid is more preferably 8.0 to 10.5. When the pH is in the range of 8.0 to 10.5, when the polishing liquid is applied to CMP, it is easy to adjust the thickness of the reaction layer under predetermined conditions to a desired range, so that the occurrence of dishing is more suppressed. Moreover, the polishing wound, which is one of the defects, is strongly influenced by the state of the surface to be polished and the type of organic acid contained in the polishing liquid. When the polishing liquid is applied to the second polishing, the polishing liquid is, as will be described later, maleic acid, fumaric acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, phthalic acid, isophthalic acid, selected from the group consisting of terephthalic acid, hemimellitic acid, trimellitic acid, trimesic acid, mellophanic acid, prenitic acid, pyromellitic acid, mellitic acid, diphenic acid, citric acid, succinic acid, malic acid, malonic acid, and anthranilic acid It is preferable to contain at least one of suppression is confirmed. It is preferable to exist in the range of 8.2-9.5, and, as for pH, it is more preferable to exist in the range of 8.7-9.5 from the point which generation|occurrence|production of dishing and the defect in the to-be-polished surface are suppressed further.

[Colloidal Silica]

The polishing liquid contains colloidal silica having association degrees 1-3.

Colloidal silica has an action of grinding the reaction layer formed in the object to be polished. It is assumed that the polishing liquid contains colloidal silica and that the thickness of the reaction layer formed under predetermined conditions is 0.5 to 20 nm as one of the reasons for exhibiting the effect of the present invention.

In this specification, the degree of association is calculated|required by association degree = average secondary particle diameter/average primary particle diameter.

The average primary particle diameter is measured by measuring the particle diameter (equivalent circle diameter) of 1000 primary particles arbitrarily selected from images taken using a transmission electron microscope TEM2010 (pressed voltage 200 kV) manufactured by Nippon Electronics Co., Ltd., and arithmetic average of them. save In addition, the equivalent circle diameter is the diameter of the said circle at the time of assuming the perfect circle which has the same projected area as the projected area of the particle|grains at the time of observation.

The average secondary particle diameter corresponds to the average particle diameter (equivalent circle diameter) of the secondary particles in the aggregated state, and can be obtained by the same method as the average primary particle diameter described above.

The association degree of colloidal silica is 1-3, and 1.5-2.5 are preferable at the point which a polishing rate is more excellent. When the association degree exceeds 3, the mechanical grinding force becomes excessive, and dishing tends to occur. Moreover, when the to-be-polished surface becomes coarse, it also becomes easy to generate|occur|produce a defect. On the other hand, when the degree of association is less than 1, it is difficult to obtain a desired polishing rate. In addition, although the average primary particle diameter in particular of colloidal silica is not restrict|limited, From the point which a polishing liquid has more excellent dispersion stability, 1-100 nm is preferable.

As a commercial item of colloidal silica of association degrees 1-3, PL2, PL3, PL3H, PL3L, etc. (all are brand names, the Fuso Chemical Co., Ltd. make) are mentioned, for example.

The content of the colloidal silica having the degree of association 1 to 3 is not particularly limited, and is preferably 0.01 mass % or more, more preferably 0.05 mass % or more, preferably 10 mass % or less, and 5 mass % with respect to the total mass of the polishing liquid. % or less is more preferable, 3 mass % or less is still more preferable, and 1 mass % or less is especially preferable.

When a polishing liquid is applied to the said 1st grinding|polishing, as content of colloidal silica of association degree 1-3, 0.01-1 mass % with respect to the total mass of a polishing liquid is more preferable. When the content of the colloidal silica having the association degrees 1 to 3 is within the above range, dishing on the surface to be polished is less likely to occur, and a more excellent polishing rate is obtained. Especially, when content of colloidal silica of association degree 1-3 exists in the range of 0.01-0.15 mass % with respect to the total mass of polishing liquid, generation|occurrence|production of dishing is further suppressed.

On the other hand, when the polishing liquid is applied to the second polishing, the content of colloidal silica having the association degrees 1-3 is more preferably 0.5 to 5 mass % with respect to the total mass of the polishing liquid.

When the content of the colloidal silica having the association degrees 1 to 3 is within the above range, dishing on the surface to be polished is less likely to occur, and a more excellent polishing rate is obtained. In particular, when the content of colloidal silica having an association degree of 1 to 3 is in the range of 0.5 to 3 mass % with respect to the total mass of the polishing liquid, the occurrence of dishing is further suppressed.

In addition, the colloidal silica of association degree 1-3 may be used individually by 1 type, and may use 2 or more types together. When using together the colloidal silica of 2 or more types of association|association degree 1-3, it is preferable that total content exists in the said range.

Among the polishing liquids, it is preferable that the ratio T2 of the average particle diameter before and after chemical mechanical polishing (CMP) calculated from the following formula (2) of colloidal silica having an association degree of 1 to 3 is 5 or less. When T2 is 5 or less, defects are more difficult to occur in the surface to be polished. It is preferable that the lower limit of the said T2 is 1 or more. 2.5 or less are more preferable, and, as for said T2, 2 or less are still more preferable.

Equation (2):

T2 = average particle diameter after chemical mechanical polishing/average particle diameter before chemical mechanical polishing

It is estimated that the colloidal silica having the association degrees 1 to 3 binds to the metal ionized material (various metal ions including cobalt ions) scraped out in the process of CMP to increase the average particle diameter.

[Hydrogen Peroxide]

The polishing liquid contains hydrogen peroxide as an oxidizing agent. The oxidizing agent has a function of oxidizing a metal to be polished existing on a polished surface of an object to be polished.

Although it does not restrict|limit especially as content of hydrogen peroxide, 0.001-5 mass % is preferable with respect to the total mass of a polishing liquid.

When the polishing liquid is applied to the first polishing, the content of hydrogen peroxide in the polishing liquid is more preferably 0.001 to 2.5 mass % with respect to the total mass of the polishing liquid, since dishing on the surface to be polished is more difficult to occur. and 0.06-2 mass % is more preferable.

On the other hand, when the polishing liquid is applied to the second polishing, the content of hydrogen peroxide in the polishing liquid is 0.001 to 3% by mass relative to the total mass of the polishing liquid, since dishing on the surface to be polished is more difficult to occur. It is more preferable, 0.1-1.2 mass % is more preferable, and 0.6-1 mass % is especially preferable.

[organic acid]

The polishing liquid contains an organic acid. The organic acid promotes metal oxidation, adjusts the pH of the polishing liquid, and functions as a buffer.

In this specification, an organic acid is a compound which has one or more acidic groups in 1 molecule, A carboxy group, a sulfonic acid group, a phosphoric acid group, etc. are mentioned with an acidic group.

It does not restrict|limit especially as an organic acid, A well-known organic acid can be used.

Examples of the organic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid , 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, phthalic acid, isophthalic acid, terephthalic acid, hemimellitic acid, trimellitic acid, trimesic acid, mellophanic acid, prenitric acid, pyromellitic acid, salts such as mellitic acid, diphenic acid, citric acid, succinic acid, malic acid, malonic acid, anthranilic acid, tartaric acid, lactic acid, hydroxyethyliminodiacetic acid, and iminodiacetic acid, and ammonium salts and alkali metal salts thereof; Glycine, α-alanine, β-alanine, N-methylglycine, L-2-aminobutyric acid, L-novaline, L-valine, L-leucine or derivatives thereof, L-proline, L-onithine, L- Lysine, taurine, L-serine, L-threonine, L-allotreonine, L-homoserine, L-tyrosine, L-thyroxine, 4-hydroxy-L-proline, L-cysteine, L-methionine, L- Ethionine, L-cystine or its derivatives, L-cysteic acid, L-aspartic acid, L-glutamic acid, 4-aminobutyric acid, L-asparagine, L-glutamine, azaserine, L-arginine, L - Amino acids, such as carnabanin, L-citrulline, δ-hydroxy-L-lysine, creatine, L-kynurenine, L-histidine or a derivative thereof, and L-tryptophan, are mentioned.

Although it does not restrict|limit especially as content of an organic acid, 0.01-30 mass % is preferable with respect to the total mass of a polishing liquid.

In addition, an organic acid may be used individually by 1 type, and may use 2 or more types together. When using together 2 or more types of organic acids, it is preferable that total content exists in the said range.

When the polishing liquid is applied to the first polishing, dishing on the surface to be polished is less likely to occur and/or defects are more unlikely to occur, so that the polishing liquid preferably contains an amino acid as an organic acid, Among them, glycine, α-alanine, β-alanine, L-aspartic acid, or N-methylglycine is more preferable, glycine or N-methylglycine is still more preferable, and glycine is particularly preferable.

When the polishing liquid is applied to the first polishing, the content of the organic acid in the polishing liquid is not particularly limited, and is preferably 0.1 mass% or more, more preferably 0.8 mass% or more, and more preferably 30 mass%, based on the total mass of the polishing liquid. % or less is preferable, 15 mass % or less is more preferable, 8 mass % or less is still more preferable, 4 mass % or less is especially preferable.

When the content of the organic acid is 0.8 to 4 mass% with respect to the total mass of the polishing liquid, dishing and defects on the surface to be polished are less likely to occur.

An organic acid may be used individually by 1 type, and may use 2 or more types together.

Moreover, since dishing on the surface to be polished is less likely to occur and/or defects are less likely to occur, it is also preferable to use an amino acid in combination with another organic acid (not including an amino acid). Examples of the organic acid include maleic acid, fumaric acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, phthalic acid, isophthalic acid, terephthalic acid, hemimellitic acid, trimellitic acid, trimesic acid, melo Panic acid, prenitric acid, pyromellitic acid, mellitic acid, diphenic acid, citric acid, succinic acid, malic acid, malonic acid, or anthranilic acid are preferred. Moreover, when using an amino acid in combination with another organic acid (amino acid is not included), 30 mass % or less is preferable with respect to the total amount of organic acids, and, as for content of another organic acid, 10 mass % is more preferable. Moreover, it is preferable that the minimum is 1 mass % or more.

When using together 2 or more types of organic acids, it is preferable that total content exists in the said range.

On the other hand, when the polishing liquid is applied to the second polishing, the polishing liquid is an organic acid, such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethyl Butyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, Glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, phthalic acid, isophthalic acid, terephthalic acid, hemimellitic acid, trimellitic acid, tri Mesic acid, mellophanic acid, prenitric acid, pyromellitic acid, mellitic acid, diphenic acid, citric acid, succinic acid, malic acid, malonic acid, anthranilic acid, tartaric acid, lactic acid, hydroxyethyliminodiacetic acid, and imino It is preferable to contain any 1 type(s) or 2 or more types selected from the group which consists of diacetic acid and salts, such as these ammonium salts and alkali metal salts. Especially, since dishing on the surface to be polished is less likely to occur and/or defects are more unlikely to occur, maleic acid, fumaric acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, Phthalic acid, isophthalic acid, terephthalic acid, hemimellitic acid, trimellitic acid, trimesic acid, mellophanic acid, prenitic acid, pyromellitic acid, mellitic acid, diphenic acid, citric acid, succinic acid, malic acid, malonic acid, or anthranyl acid is preferred, maleic acid, 2-hydroxybenzoic acid, 4-hydroxybenzoic acid, phthalic acid, trimellitic acid, citric acid, succinic acid, malic acid, malonic acid, or anthranilic acid is more preferred, maleic acid, or citric acid further preferred, and maleic acid is particularly preferred.

Moreover, when two or more types of organic acids are used in combination, dishing on the surface to be polished is less likely to occur and/or defects are less likely to occur, and among them, maleic acid, citric acid, succinic acid, and malic acid , malonic acid, phthalic acid, 4-hydroxybenzoic acid, 2-hydroxybenzoic acid, anthranilic acid, and a combination with at least one selected from the group consisting of trimellitic acid, maleic acid, citric acid, malonic acid, 4 - A combination with at least one selected from the group consisting of -hydroxybenzoic acid, 2-hydroxybenzoic acid, anthranilic acid, and trimellitic acid is more preferable, maleic acid and citric acid, 4-hydroxybenzoic acid, 2-hydroxy A combination with at least one selected from the group consisting of benzoic acid, anthranilic acid, and trimellitic acid is more preferred.

When the polishing liquid is applied to the second polishing, the content of the organic acid in the polishing liquid is not particularly limited, and is preferably 0.01 to 30 mass%, more preferably 0.01 to 12 mass%, based on the total mass of the polishing liquid, 0.01-5 mass % is more preferable, and 0.01-0.3 mass % is especially preferable. Moreover, when using 2 or more types of organic acids, it is preferable that total content exists in the said range.

[Azole-based compound]

The polishing liquid contains an azole compound. The azole-based compound has an effect of forming a reaction layer on the metal surface of the surface to be polished. Moreover, it has the function of improving the oxidation action by hydrogen peroxide mentioned later.

In the present specification, the azole compound is intended to be a compound containing a hetero five-membered ring containing one or more nitrogen atoms, and the number of nitrogen atoms is preferably 1-4. Moreover, the azole compound may contain atoms other than a nitrogen atom as a hetero atom. Moreover, the azole compound may have a substituent on the said hetero five-membered ring.

Examples of the azole-based compound include a pyrrole skeleton, an imidazole skeleton, a pyrazole skeleton, an isothiazole skeleton, an isoxazole skeleton, a triazole skeleton, a tetrazole skeleton, a thiazole skeleton, an oxazole skeleton, and a thiazole skeleton. The compound etc. which have frame|skeleton or oxadiazole skeleton are mentioned.

The azole-based compound may be an azole-based compound further having a polycyclic structure in which an aromatic hydrocarbon ring or an aromatic heterocycle is condensed on the skeleton. Examples of the azole compound containing the polycyclic structure include indole skeleton, purine skeleton, indazole skeleton, benzimidazole skeleton, carbazole skeleton, benzoxazole skeleton, benzothiazole skeleton, benzothiazole skeleton, Or the compound containing a naphthoimidazole skeleton, etc. are mentioned.

The substituent that the azole compound may contain is not particularly limited, but for example, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group (a straight-chain, branched-chain or cyclic alkyl group, It may be a polycyclic alkyl group such as a bicycloalkyl group or may include an active metaphosphorus 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 Nyl group, heterocyclic oxycarbonyl group, carbamoyl group (as carbamoyl group having a substituent, for example, N-hydroxycarbamoyl group, N-acylcarbamoyl group, N-sulfonylcarbamoyl group, N-carbamoyl group carbamoyl group, thiocarbamoyl group, and N-sulfamoylcarbamoyl group), carbazoyl group, carboxyl group or a salt thereof, oxalyl group, oxamoyl group, cyano group, carbonimidoyl group, A formyl group, a hydroxyl group, an alkoxy group (including a group containing an ethyleneoxy group or a propyleneoxy group as a repeating unit), an aryloxy group, a heterocyclic oxy group, an acyloxy group, a carbonyloxy group, a carbamoyloxy group, a sulfonyloxy group Group, amino group, acylamino group, sulfonamide group, ureido group, thioureido group, N-hydroxyureido group, imide group, carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, hydrazi No group, ammony group, oxamoylamino group, N- (alkyl or aryl) sulfonylureido group, N-acylureido group, N-acylsulfamoylamino group, hydroxyamino group, nitro group, containing a quaternized nitrogen atom Heterocyclic group (for example, pyridini group, imidazoli group, quinolini group, and isoquinolini group are mentioned), isocyano group, imino group, mercapto group, (alkyl, aryl, or hetero Ring) 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 (sulfamoyl group having a substituent) Examples thereof include N-acylsulfamoyl group and N-sulfonylsulfamoyl group) or salts thereof, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, and silyl and the like.

Among them, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group is preferable.

In addition, here, "active metaphosphorus group" means metaphosphorus group substituted with two electron withdrawing groups. The "electron withdrawing group" means, for example, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfamoyl group, a trifluoromethyl group, a cyano group, and a nitro group. , or a carboxylamide group. Moreover, two electron withdrawing groups may mutually couple|bond and take a cyclic structure. In addition, "salt" refers to cations such as alkali metals, alkaline earth metals, and heavy metals; Organic cations, such as an ammonium ion and a phosphonium ion, are intended.

As the azole-based compound, a compound having a triazole skeleton (triazole-based compound), a pyrazole-based compound, or an imidazole skeleton because dishing on the surface to be polished is less likely to occur and/or defects are less likely to occur. A compound having (imidazole-based compound) is preferable, and a compound having a triazole skeleton is more preferable.

Further, among the compounds having a triazole skeleton, from the viewpoint that dishing on the surface to be polished is less likely to occur and/or defects are more unlikely to occur, a compound having a benzotriazole skeleton (benzotriazole-based compound), or A compound having a 1,2,4-triazole skeleton (1,2,4-triazole-based compound) is preferable, and a compound having a benzotriazole skeleton is more preferable.

Examples of the compound having a benzotriazole skeleton include 5-methylbenzotriazole, 5-aminobenzotriazole, benzotriazole, and 5,6-dimethylbenzotriazole.

Moreover, as a compound which has 1,2,4-triazole skeleton, 3-amino-1,2,4-triazole, 1,2,4-triazole, etc. are mentioned, for example.

Although the azole-type compound may be used individually by 1 type, or may use 2 or more types together, since dishing on the to-be-polished surface is more difficult to generate|occur|produce and/or a defect is more difficult to generate|occur|produce, benzotriazole skeleton It is preferable to use a compound having , and a compound different from the benzotriazole-based compound (a compound not containing a benzotriazole skeleton) in combination. A compound containing a benzotriazole skeleton is easily coordinated with cobalt oxidized by hydrogen peroxide as an oxidizing agent to form a reaction layer. On the other hand, even if it is an azole compound, a compound which does not contain a benzotriazole skeleton coordinates relatively weakly with oxidized cobalt, and it is easy to form a reaction layer. The reaction layer formed when a polishing liquid containing a benzotriazole-based compound and a compound other than benzotriazole is applied to CMP is a layer formed of the benzotriazole-based compound and a compound different from benzotriazole It is assumed that it contains a layer formed by

The layer formed of the benzotriazole type compound which coordinates more strongly with oxidized cobalt is dense, and it is estimated that it has the effect|action which suppresses generation|occurrence|production of dishing more. On the other hand, since a layer formed of a compound different from the benzotriazole-based compound that more weakly coordinates with the oxidized cobalt is more easily removed, it is estimated that an excellent polishing rate is easily obtained as a result.

As a result, the above action is increased, so that when a polishing liquid containing a compound having a benzotriazole skeleton and a compound different from the benzotriazole-based compound (a compound not containing a benzotriazole skeleton) is applied to CMP, better results are obtained. A polishing rate can be obtained, and dishing is more difficult to generate|occur|produce on a grinding|polishing surface.

Although there is no restriction|limiting in particular as a compound which does not contain the said benzotriazole skeleton, A 1,2,4-triazole skeleton from the point which dishing on the to-be-polished surface is more difficult to generate|occur|produce and/or a defect is more difficult to generate|occur|produce. It is preferable that it is at least 1 sort(s) selected from the group which consists of a compound which has a compound, a pyrazole type compound, and a compound which has an imidazole skeleton.

The content of the azole-based compound is not particularly limited, and is preferably 0.001 to 10 mass% with respect to the total mass of the polishing liquid. Moreover, when using 2 or more types of azole compounds, it is preferable that total content exists in the said range.

When the polishing liquid is applied to the first polishing, the content of the azole compound is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and preferably 2% by mass or less, based on the total mass of the polishing liquid, , 1.3 mass % or less is more preferable, and 0.4 mass % or less is still more preferable.

When the content of the azole compound is 0.01% by mass or more, dishing is less likely to occur on the surface to be polished.

When the content of the azole-based compound is 1.3% by mass or less, dishing is less likely to occur on the surface to be polished, and stability over time is more excellent.

When the polishing liquid is applied to the first polishing, the polishing liquid may contain two or more azole compounds (preferably, a compound having a benzotriazole skeleton, and a compound different from the benzotriazole compound ), the respective content is not particularly limited, and the mass ratio of the content of other azole compounds to the azole compound having the smallest content in the polishing liquid is preferably 5 or more, and more preferably 100 or more. , 1800 or less are preferable, 1300 or less are more preferable, and 400 or less are still more preferable. Moreover, it is preferable that content of the compound which has benzotriazole skeleton is less than content of the compound other than a benzotriazole type compound.

When the polishing liquid is applied to the second polishing, the content of the azole compound is preferably 0.1 mass % or more, more preferably 0.12 mass % or more, and preferably 6 mass % or less, with respect to the total mass of the polishing liquid, , 3.5 mass % or less is more preferable, 0.8 mass % or less is still more preferable, and 0.5 mass % or less is especially preferable.

When the content of the azole-based compound is 0.12% by mass or more, dishing is less likely to occur on the surface to be polished.

When the content of the azole-based compound is 5% by mass or less, dishing is less likely to occur on the surface to be polished, and stability over time is more excellent.

On the other hand, when the polishing liquid is applied to the second polishing, the polishing liquid may contain two or more azole compounds (preferably, a compound having a benzotriazole skeleton, and a compound different from the benzotriazole compound When contained), the respective content is not particularly limited, and the mass ratio of the content of the azole-based compound to the azole-based compound having the lowest content in the polishing liquid is preferably 0.05 or more, and more than 0.5 or more. It is preferable, 50 or less are preferable, and 10 or less are more preferable. Moreover, it is preferable that there is more content of the compound which has benzotriazole skeleton than content of the compound other than a benzotriazole type compound.

If it is in the said range, dishing in the to-be-polished surface is more difficult to generate|occur|produce, and/or a defect is more difficult to generate|occur|produce.

In addition, in the polishing liquid, the azole-based compound having the lowest content is intended to have the smallest content among two or more azole-based compounds, and a plurality of azole-based compounds among two or more azole-based compounds may correspond to this.

In addition, an azole type compound may use 3 or more types together. When using together 3 or more types of azole-type compounds, it is preferable that content of each azole-type compound exists in the said range, respectively.

[Optional Ingredients]

The polishing liquid may contain components other than the above as optional components. Hereinafter, optional components will be described.

<Abrasive grain>

The polishing liquid may further contain abrasive grains other than colloidal silica.

It does not restrict|limit especially as said abrasive grain, Abrasive grains other than well-known colloidal silica can be used.

Examples of the abrasive grains include inorganic abrasive grains such as silica (precipitated silica other than colloidal silica, or fumed silica), alumina, zirconia, ceria, titania, germania, and silicon carbide; and organic material abrasive grains, such as polystyrene, polyacryl, and polyvinyl chloride.

<Organic solvent>

It is preferable that the said polishing liquid contains an organic solvent. It does not restrict|limit especially as an organic solvent, A well-known organic solvent can be used. Especially, a water-soluble organic solvent is preferable.

Examples of the organic solvent include ketone solvents, ether solvents, alcohol solvents, glycol solvents, glycol ether solvents, and amide solvents.

More specifically, for example, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, acetonitrile, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, ethylene glycol, propylene glycol, and ethoxyethanol are mentioned.

Especially, methyl ethyl ketone, tetrahydrofuran, dioxane, N-methylpyrrolidone, methanol, ethanol, propylene glycol, or ethylene glycol is preferable, and methanol, ethanol, propylene glycol, or ethylene Glycol is more preferable, and methanol, propylene glycol, or ethylene glycol is more preferable.

Although it does not restrict|limit especially as content of organic solvent, 0.01-20 mass % is preferable, 0.01-10 mass % is more preferable with respect to the total mass of a polishing liquid from the point which the effect of this invention is more excellent, 0.01-8 mass % is more preferable.

When content of the organic solvent is in the range of 0.01-20 mass %, it becomes more difficult to generate|occur|produce the defect in to-be-polished surface.

Moreover, an organic solvent may be used individually by 1 type, and may use 2 or more types together. When using together 2 or more types of organic solvents, it is preferable that total content exists in the said range.

<Surfactant and/or hydrophilic polymer>

The polishing liquid may contain a surfactant and/or a hydrophilic polymer. Surfactants and hydrophilic polymers (hereinafter also referred to as "hydrophilic polymers") have an action of lowering the contact angle of the polishing liquid with respect to the surface to be polished, and the polishing liquid tends to wet and diffuse on the surface to be polished.

The surfactant is not particularly limited, and known surfactants selected from the group consisting of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants can be used.

Examples of the anionic surfactant include carboxylate, sulfonic acid salts such as alkylbenzenesulfonic acid, sulfuric acid ester salts, and phosphoric acid ester salts.

Examples of the cationic surfactant include aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium chlorides, benzethonium chlorides, pyridinium salts, and imidazolinium salts.

Examples of the amphoteric surfactant include carboxybetaine type, aminocarboxylate, imidazolinium betaine, lecithin, and alkylamine oxide.

Examples of the nonionic surfactant include an ether type, an etherester type, an ester type, a nitrogen-containing type, a glycol type, and a fluorine type surfactant.

Examples of the hydrophilic polymer include polyglycols such as polyethylene glycol, alkyl ethers of polyglycols, polysaccharides such as polyvinyl alcohol, polyvinylpyrrolidone and alginic acid, polymethacrylic acid, and poly Carboxylic acid-containing polymers, such as acrylic acid, polyacrylamide, polymethacrylamide, polyethyleneimine, etc. are mentioned. As a specific example of such a hydrophilic polymer, the water-soluble polymer described in Unexamined-Japanese-Patent No. 2009-088243 Paragraph 0042 - Paragraph 0044 and Unexamined-Japanese-Patent No. 2007-194261 Paragraph 0026 is mentioned.

In the above embodiment, the water-soluble polymer is preferably a water-soluble polymer selected from polyacrylamide, polymethacrylamide, polyethyleneimine, and polyvinylpyrrolidone. As polyacrylamide or polymethacrylamide, those having a hydroxyalkyl group on the nitrogen atom (eg, N-(2-hydroxyethyl)acrylamide polymer, etc.) or those having a substituent having a polyalkyleneoxy chain It is preferable, and, as for a weight average molecular weight, it is more preferable that it is 2000-50000. As polyethyleneimine, it is preferable to have a polyalkyleneoxy chain on a nitrogen atom, and what has a repeating unit represented by the following general formula is more preferable.

[Formula 1]

In the above formula, n represents a number of 2 to 200 (in the case of a mixture, the average number).

Moreover, it is preferable to use the thing of HLB (Hydrophile-Lipophile Balance) value 16-19 as for polyethyleneimine.

Although it does not restrict|limit especially as content of surfactant or hydrophilic polymer, 0.00001-2 mass % is preferable with respect to the total mass of polishing liquid, 0.0001-1 mass % is more preferable, 0.0001-0.5 mass % is still more preferable. If the content of the surfactant or hydrophilic polymer is 0.0001 to 0.5 mass %, when the polishing liquid is applied to CMP, the average particle diameter of colloidal silica having an association degree of 1 to 3 after chemical mechanical polishing is difficult to fluctuate, so the effect of the present invention is better than

Moreover, surfactant or hydrophilic polymer may be used individually by 1 type, and may use 2 or more types together. Moreover, you may use together surfactant and a hydrophilic polymer. When using together 2 or more types of surfactant, or 2 or more types of hydrophilic polymers, or surfactant and a hydrophilic polymer, it is preferable that total content exists in the said range.

<pH adjuster and/or pH buffer>

The said polishing liquid may further contain a pH adjuster and/or a pH buffering agent in order to set it as predetermined pH. As a pH adjuster and/or a pH buffering agent, a powder and/or an alkali agent are mentioned. In addition, a pH adjuster and a pH buffer are compounds different from the said organic acid.

Although it does not restrict|limit especially as a powder, An inorganic acid is preferable. Examples of the inorganic acid include sulfuric acid, nitric acid, boric acid, and phosphoric acid. Among these, nitric acid is more preferable.

Although it does not restrict|limit especially as an alkali agent, Ammonium hydroxide and organic ammonium hydroxide; alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; carbonates such as sodium carbonate; phosphates such as trisodium phosphate; borate, and tetraborate; and the like.

The content of the pH adjuster and/or the pH buffer is not particularly limited as long as it is an amount necessary for maintaining the pH in a desired range, and is usually preferably 0.0001 to 0.1% by mass based on the total mass of the polishing liquid.

<Cobalt Anticorrosive>

The polishing liquid is a cobalt anticorrosive agent, N-cocoyl sarcosinate, N-lauroyl sarcosinate, N-stearoyl sarcosinate, N-oleoyl sarcosinate, N-myristoyl sarcosinate, N-lauroylglycine, N-myristoylglycine, N-palmitoylglycine, N-lauroylglutamic acid, N-cocoylglutamic acid, N-cocoylglutamic acid potassium, N-lauroyl sarcosinate potassium, N It is preferable to contain at least one compound selected from the group consisting of -lauroylalaninate, N-myristoylalaninate, and N-cocoylalaninate potassium. The cobalt anticorrosive agent has a function of suppressing excessive corrosion of cobalt by coordinating with cobalt in the surface of the object to be polished to form a complex (composite compound).

Although it does not restrict|limit especially as content of the said cobalt anticorrosive agent, 0.001-5 mass % is preferable with respect to the total mass of abrasive liquid, 0.001-1 mass % is more preferable, 0.001-0.5 mass % is still more preferable. When the content of the cobalt anticorrosive agent is 0.001 to 5% by mass, dishing is less likely to occur on the surface to be polished, and defects are less likely to occur on the surface to be polished.

Moreover, the said cobalt anticorrosive agent may be used individually by 1 type, and may use 2 or more types together. When using together 2 or more types of said cobalt anticorrosive agent, it is preferable that total content exists in the said range.

<water>

It is preferable that the said polishing liquid contains water. Although it does not restrict|limit especially as water contained in the said polishing liquid, Ion-exchange water, pure water, etc. can be used.

Although it does not restrict|limit especially as content of water, Usually, 90-99 mass % is preferable with respect to the total mass of a polishing liquid.

<Metal impurities>

The said polishing liquid may contain the metal impurity containing a metal atom.

In addition, in this specification, "metal impurity containing a metal atom" means a metal ion and a solid (a metal simple substance, a particulate metal-containing compound, etc. Hereinafter, these are collectively referred to as a "metal particle") Metal impurities contained in the polishing liquid are intended. For example, when the metal atom is an Fe atom, a solid containing Fe ions and Fe atoms corresponds to the case.

In addition, in this specification, content of the metal atom which the metal impurity contains in a polishing liquid intends content of the metal atom measured by ICP-MS(inductively coupled plasma mass spectrometry). In addition, the measuring method of content of a metal atom using ICP-MS is as described in the Example mentioned later.

In addition, content of the metal atom which the metal particle contains in polishing liquid intends content of the metal atom measured by SNP-ICP-MS (single nanoparticle inductively coupled plasma mass spectrometry). In addition, the measuring method of the content of metal atoms using SNP-ICP-MS is as described in the Example mentioned later.

The type of metal atom contained in the metal impurity is not particularly limited, and examples thereof include an Fe atom, a Cu atom, an Ag atom, and a Zn atom.

Moreover, content of at least 1 sort(s) of specific metal atom selected from the group which consists of an Fe atom, Cu atom, Ag atom, and Zn atom among the said metal atoms is as follows.

When the polishing liquid contains one specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms, the content of the one specific metal atom is based on the total mass of the polishing liquid. It is preferable to set it as 0.001-200 mass ppb with respect to, 0.01-200 mass ppb is more preferable, 0.01-100 mass ppb is still more preferable, 0.01-50 mass ppb is especially preferable, 0.01-20 mass ppb is the most preferable do.

When the content of the specific metal atom is within the above range with respect to the total mass of the polishing liquid, dishing and defects on the surface to be polished are less likely to occur, and the stability with time is more excellent.

In the case of containing two or more specific metal atoms selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms, the content of each specific metal atom is 0.001 to 200 mass with respect to the total mass of the polishing liquid. ppb is preferable, 0.01-200 mass ppb is more preferable, 0.01-100 mass ppb is still more preferable, 0.01-50 mass ppb is especially preferable, and 0.01-20 mass ppb is the most preferable.

That is, for example, when two types of specific metal atoms, Fe atoms and Cu atoms, are contained in the polishing liquid, it is preferable that both content of Fe atoms and content of Cu atoms exist in the range of 0.001-200 mass ppb.

In addition, from the viewpoint of further reducing defects on the surface to be polished, the content of metal particles containing at least one specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms in the polishing liquid It is desirable to control in a predetermined range. In other words, it is preferable that the amount of solid metal impurities is appropriately adjusted in the polishing liquid.

When the polishing liquid contains the metal particles, when the specific metal atom contained in the metal particles is one type, the content of the one type is preferably 0.01 to 50 mass ppb with respect to the total mass of the polishing liquid, 0.01 ~8 mass ppb is more preferable.

When the said polishing liquid contains the said metal particle, when the specific metal atom contained in the said metal particle is 2 or more types, each content is 0.01-50 mass ppb with respect to the total mass of a polishing liquid, 0.01-50 mass ppb is preferable, 0.01- 8 mass ppb is more preferable. That is, for example, when metal particles containing Fe atoms and metal particles containing Cu atoms are contained in the polishing liquid, it is preferable that both the Fe atom content and the Cu atom content are in the range of 0.01 to 50 mass ppb. do.

The metal impurity containing the metal atom may be added to the polishing liquid, or may be unavoidably mixed in the chemical solution in the manufacturing process of the polishing liquid. Examples of the case where they are unavoidably mixed in the manufacturing process of the polishing liquid include, for example, when the metal impurity containing the metal atom is contained in the raw material (eg, organic solvent) used for the production of the polishing liquid, and polishing In the case of mixing in the manufacturing process of the liquid (for example, contamination), etc. are mentioned, but it is not limited to the above.

Further, the polishing liquid has a content ratio T1 of hydrogen peroxide calculated from the following formula (1) and a specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms contained in the metal impurities. It is preferable that this is 30000-50000.

Formula (1): T1 = content of hydrogen peroxide/total content of specific metal atoms selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms contained in metallic impurities

Hydrogen peroxide decomposes metal atoms such as Fe as a catalyst to generate hydroperoxo species with strong oxidizing power. On the other hand, the cobalt atom has a low oxidation potential compared with a copper atom, which is a wiring metal element, and tends to be relatively easily oxidized. Therefore, when the object to be polished is a cobalt-containing layer, the surface to be polished is likely to be scraped by the generated hydroperoxo species, and excessive corrosion occurs. As a result, it is estimated that dishing is likely to occur. In the polishing liquid, when T1 is 30000 or more, the generation of the hydroperoxo species can be further suppressed, so that dishing is less likely to occur on the surface to be polished, and defects on the surface to be polished are also less likely to occur.

In addition, in the polishing liquid, when T1 is 500000 or less, the difference between the content of hydrogen peroxide and the content of metal ions is sufficiently large (that is, the oxidizing power of the metal itself is difficult to reach), so that dishing is more difficult to occur on the surface to be polished, Moreover, the defect of the to-be-polished surface is also more difficult to generate|occur|produce.

When the polishing liquid is applied to the first polishing, dishing and defects on the surface to be polished are less likely to occur, so that the T1 is more preferably 110000 or less, and still more preferably 80000 or less.

When the polishing liquid is applied to the second polishing, dishing and defects on the surface to be polished are less likely to occur, so that T1 is more preferably 100000 or more, and still more preferably 250000 or more.

<The compound represented by the general formula (1)>

The said polishing liquid may contain the compound represented by following General formula (1).

General formula (1):

N(R ¹ )(R ² )(R ³ )

In General Formula (1), R ¹ to R ³ each independently represent a hydrogen atom or an alkyl group.

As a compound represented by the said General formula (1), For example, ammonia; Alkanolamines, such as ethanolamine, a diethanolamine, a triethanolamine, and a triisopropanolamine, are mentioned.

The content of the compound represented by the general formula (1) in the polishing liquid is preferably 1500 mass ppb or less, more preferably 1000 mass ppb or less, and still more preferably 250 mass ppb or less, with respect to the total mass of the polishing liquid. and 8 mass ppb or less is especially preferable.

When the content of the compound represented by the general formula (1) in the polishing liquid is 1500 mass ppb or less, the coordination of the compound to cobalt on the surface to be polished is suppressed, and on the other hand, the complex with the cobalt by the azole compound is It becomes easy to form a layer. As a result, dishing is less likely to occur on the surface to be polished, and defects on the surface to be polished are also less likely to occur.

Although the minimum of content of the compound represented by the said General formula (1) in a polishing liquid is not specifically limited, For example, it is 0.00001 mass ppb or more.

In addition, content of the compound represented by General formula (1) in the said polishing liquid can be measured using GCMS (gas chromatography mass spectrometry). In addition, measurement conditions etc. are as having described in an Example.

As described above, the polishing liquid is suitably used for CMP performed for planarization of buried wirings (cobalt wirings) or the like at the time of manufacturing a semiconductor integrated circuit device. When the polishing liquid is applied to the first polishing, the polishing liquid is preferably the polishing liquid of Embodiment 1 below, and when the polishing liquid is applied to the second polishing, the polishing liquid is the polishing liquid of Embodiment 2 below it is preferable

<Polishing liquid of Embodiment 1>

The polishing liquid of Embodiment 1,

A polishing liquid for chemical mechanical polishing containing colloidal silica of association degrees 1 to 3, an organic acid, an azole compound, and hydrogen peroxide,

The content of colloidal silica in the association degrees 1 to 3 is 0.01 to 1 mass % with respect to the total mass of the polishing liquid,

As said organic acid, it contains an amino acid,

As the azole-based compound, containing at least two or more triazole-based compounds, the pH is 6.5 to 8.0,

When the polishing liquid and the cobalt substrate are brought into contact for 24 hours, a reaction layer (reaction layer 1) having a thickness of 0.5 to 20 nm containing cobalt atoms is formed on the cobalt substrate, and the polishing liquid and Ta, TaN, Ti , TiN, Ru, and when a barrier substrate made of any one metal selected from the group consisting of Mn is in contact with the barrier substrate for 24 hours, a reaction layer with a thickness of 0.01 to 5 nm containing the metal atoms on the barrier substrate ( It is preferable that it is a polishing liquid in which the "reaction layer 2") is formed hereafter.

The thickness of the reaction layer 2 is 0.01 nm or more, preferably 0.1 nm or more. Moreover, the thickness of the said reaction layer 2 is 5 nm or less, and 3.0 nm or less is preferable.

When the thickness of the reaction layer 2 is 0.01 nm or more and 5 nm or less, the effect of the present invention is more excellent.

The reaction layer 2 in the present specification refers to a barrier made of any one metal (barrier metal) selected from the group consisting of Ta, TaN, Ti, TiN, Ru, and Mn having a surface to be polished of 10 mm×10 mm. When a substrate (a metal substrate made of a barrier metal) is immersed in 10 mL of a polishing liquid, and the barrier substrate and the polishing liquid are brought into contact with the polishing liquid at 25° C. for 24 hours, a reaction layer formed on the polished surface of the barrier substrate is intended do.

Moreover, when immersing the said barrier substrate in a polishing liquid, the aspect which immersed the said barrier substrate and the laminated body which laminated|stacked the other board|substrate (for example, a silicon substrate) in a polishing liquid may be sufficient.

The reaction layer 2 contains atoms (barrier metal atoms) of any one metal selected from the group consisting of Ta, TaN, Ti, TiN, Ru, and Mn. The reaction layer 2 may further contain an oxygen atom or the like, and it is preferable that the surface of the reaction layer contains a complex of a component in the polishing liquid.

Here, the thickness of the reaction layer 2 is observed by the method described in Examples using a scanning electron microscope (SEM) to observe the cross section of the barrier substrate after contacting the polishing liquid and the barrier substrate for 24 hours. The thickness obtained by doing this is intended.

The polishing liquid may form a reactive layer 2 on a barrier substrate made of any one metal selected from the group consisting of Ta, TaN, Ti, TiN, Ru, and Mn under the predetermined conditions. , it is preferable that the reactive layer 2 can be formed on each of the substrates made of Ta, TaN, Ti, TiN, Ru, and Mn.

The polishing liquid is preferably adjusted so that the polishing rate ratio R1 calculated from the following formula (3) is 250 to 2500 from the viewpoint of further suppressing the occurrence of dishing on the surface to be polished.

Equation (3):

R1 = polishing rate of the cobalt substrate by the polishing liquid / polishing rate of the barrier substrate by the polishing liquid

In the polishing of the barrier layer, in general, mechanical polishing has a greater contribution than chemical polishing. In other words, even when the reaction layer 2 is formed, the polishing rate does not increase significantly. For this reason, when making the polishing rate ratio R1 into the said predetermined numerical range, it is preferable to adjust so that the polishing rate of the cobalt-containing layer by a polishing liquid may rise. In addition, it is the same also about the grinding|polishing rate ratio R2 mentioned later.

Colloidal silica, an organic acid, and an azole compound of the association degrees 1-3 which the polishing liquid of Embodiment 1 contains, and an arbitrary component are each as above-mentioned, and a preferable aspect is also the same. Moreover, it is as above-mentioned also about the said reaction layer 1, and a preferable aspect is also the same.

<Polishing liquid of Embodiment 2>

The polishing liquid of Embodiment 2,

A polishing liquid for chemical mechanical polishing containing colloidal silica of association degrees 1 to 3, an organic acid, an azole compound, and hydrogen peroxide,

The content of colloidal silica in the association degrees 1 to 3 is 0.5 to 5 mass % with respect to the total mass of the polishing liquid,

As the azole-based compound, it contains a triazole-based compound,

The pH is 8.0 to 10.5,

When the polishing liquid and the cobalt substrate are brought into contact for 24 hours, a reaction layer with a thickness of 0.5 to 20 nm containing cobalt atoms (corresponding to the “reaction layer 1”) is formed on the cobalt substrate, and

When the polishing liquid is in contact with a barrier substrate made of any one metal selected from the group consisting of Ta, TaN, Ti, TiN, Ru, and Mn for 24 hours, the metal atom is contained on the barrier substrate A reaction layer with a thickness of 0.01 to 5 nm (corresponding to the "reaction layer 2" above) is formed,

When the polishing liquid and the insulating film substrate made of any one inorganic component selected from the group consisting of SiOx and SiOC are in contact for 24 hours, a reaction layer with a thickness of 0.01 to 10 nm containing the inorganic component on the insulating film substrate (hereinafter referred to as the following) It is preferable that it is a polishing liquid in which the "reaction layer 3") is formed.

The thickness of the reaction layer 3 is 0.01 nm or more, preferably 0.1 nm or more. Moreover, the thickness of the said reaction layer 3 is 10 nm or less, and 5 nm or less is preferable.

When the thickness of the reaction layer 3 is 0.01 nm or more and 10 nm or less, the effect of the present invention is more excellent.

Reaction layer 3 in the present specification refers to an insulating film substrate made of any one inorganic component selected from the group consisting of SiOx and SiOC having a surface to be polished of 10 mm × 10 mm, immersed in 10 mL of a polishing solution, A reaction layer formed on the surface to be polished of the insulating film substrate when the insulating film substrate and the polishing liquid are brought into contact at 25° C. for 24 hours is intended.

In addition, when the said insulating film substrate is immersed in a polishing liquid, the aspect which immerses the said insulating film substrate and the laminated body which laminated|stacked the other board|substrate (for example, a silicon substrate) in a polishing liquid may be sufficient.

The said reaction layer 3 contains the said inorganic component. The reaction layer 3 may further contain an oxygen atom or the like, and it is preferable that the surface of the reaction layer contains a complex of a component in the polishing liquid.

Here, the thickness of the reaction layer 3 is observed by the method described in Examples using a scanning electron microscope (SEM) after the polishing liquid and the insulating film substrate are brought into contact for 24 hours, and then the cross section of the insulating film substrate after contact is observed. The thickness obtained by doing this is intended.

The polishing liquid may form a reaction layer 3 on an insulating film substrate made of any one inorganic component selected from the group consisting of SiOx and SiOC under the predetermined conditions. It is preferable that the reactive layer 3 can be formed on each of all the substrates of the formed substrate.

The polishing liquid is preferably adjusted so that the polishing rate ratio R2 calculated from the following formula (4) is 0.01 to 2.0 from the viewpoint of further suppressing the occurrence of dishing on the surface to be polished. Moreover, it is preferable to adjust so that polishing rate ratio R3 computed from following formula (5) may be set to 0.05-2.0.

Equation (4):

R2 = polishing rate of the cobalt substrate by the polishing liquid / polishing rate of the barrier substrate by the polishing liquid

Equation (5):

R3 = polishing rate of the cobalt substrate by the polishing liquid / polishing rate of the insulating film substrate by the polishing liquid

The colloidal silica, organic acid, and azole compound of the association degrees 1-3 which the polishing liquid of Embodiment 2 contains, and an arbitrary component are each as above-mentioned, respectively. In addition, the reaction layer 1 and the reaction layer 2 are the same as described above.

[Method for preparing polishing liquid]

The said polishing liquid can be manufactured by a well-known method. For example, it can manufacture by mixing each said component. The order and/or timing of mixing each component is not particularly limited, and colloidal silica having an association degree of 1 to 3 may be dispersed in advance in water with pH adjusted, and predetermined components may be mixed sequentially. In addition, hydrogen peroxide, water, or hydrogen peroxide and water may be separately stored until immediately before use of the abrasive, and may be mixed immediately before use. Moreover, it is preferable to manufacture the said grinding|polishing liquid by the following method which has a dilution process of diluting with water immediately before use.

[Method for producing abrasive solution]

In the method for producing a polishing liquid according to the first embodiment of the present invention, water is mixed with a polishing liquid stock solution containing colloidal silica of association degrees 1 to 3, an organic acid, an azole compound, and hydrogen peroxide, , a process for obtaining the polishing liquid (hereinafter also referred to as a “dilution step”), a method for producing a polishing liquid.

[dilution process]

The dilution step is a step of obtaining a polishing liquid by mixing water with the polishing liquid stock solution containing a predetermined component.

The aspect of the polishing liquid is as described above. Moreover, it does not restrict|limit especially as a method of mixing water, A well-known method can be used.

<Abrasive undiluted solution>

The polishing liquid stock solution used in the dilution step is a polishing solution stock solution containing colloidal silica having an association degree of 1 to 3, an organic acid, an azole compound, and hydrogen peroxide, and further mixed with water to obtain a polishing solution It is an undiluted polishing liquid used for manufacturing.

As the polishing liquid stock solution, the polishing liquid can be obtained by mixing a solvent such as water, and in addition to the above components, an organic solvent, a surfactant, a hydrophilic polymer, a pH adjuster, a pH buffer, and a cobalt anticorrosive agent are contained according to the purpose. You can do it.

The undiluted polishing liquid is preferably a liquid obtained by concentrating the polishing liquid 2 to 50 times when actually used for CMP. That is, the polishing liquid stock solution is diluted 2 to 50 times before use. In the case of dilution, it is preferable to use water.

The method for preparing the polishing liquid stock solution is not particularly limited, and it can be prepared by a known method. For example, it can manufacture by mixing each said component. The order of mixing each of the above components is not particularly limited, and the colloidal silica may be dispersed in advance in water and/or an organic solvent having pH adjusted, and predetermined components may be mixed sequentially.

In addition, when the polishing liquid stock solution is diluted 2 to 50 times with water, it is preferable that the pH change before and after dilution is 0.01 to less than 1.

The present inventors inspected the performance state before and after dilution of the polishing stock solution. When the pH change before and after dilution was 0.01 to less than 1, it was confirmed that the performance change due to dilution was suppressed. Specifically, it was confirmed that, when the pH change before and after the dilution of the polishing liquid stock solution was 0.01 or more, the performance change due to the dilution did not substantially occur. On the other hand, when the pH change before and after dilution of the polishing liquid stock solution was less than 1, it was confirmed that the performance change due to dilution was small and the performance was not significantly impaired.

Further, as another aspect of the method for producing a polishing liquid, a concentrated liquid of a polishing liquid containing a predetermined component is prepared, and hydrogen peroxide or hydrogen peroxide and water are added thereto to produce a polishing liquid having predetermined characteristics. how to do it

[Abrasive solution undiluted receptor]

The polishing liquid undiluted solution container of the present invention is configured to include the above-mentioned polishing liquid stock solution and a container made of an iron-free metal material for accommodating the polishing liquid stock solution.

Here, "iron-free metallic material" means a metallic material substantially free of iron, for example, the content of iron atoms is 30% or less, preferably 20% or less, based on the total atomic weight. Metal materials are intended.

The above-mentioned polishing liquid stock solution is a metal material that does not contain iron (hereinafter also referred to as "non-ferrous metal material") in that the impurity content does not easily increase even when the polishing liquid stock solution is stored for a predetermined period and the decomposition of hydrogen peroxide is suppressed. ) is preferably accommodated in a container formed of. As for the said container, the inner wall which contacts the grinding|polishing liquid stock solution should just be formed of the nonferrous metal material, and it is not specifically limited about another structure.

As the container in which the inner wall is formed of a non-ferrous material, a container in which the inner wall is coated with at least one material selected from the group consisting of a non-metallic material and an electrolytically polished non-metal material, or a container in which the inner wall is formed of a material is preferable.

In addition, in this specification, "coating" intends that the said inner wall is covered with the said material. As an aspect in which the said inner wall is covered with the said material, it is preferable that 70% or more of the total surface area of an inner wall is covered with the said material.

Examples of the non-metallic material include polyethylene resin, polypropylene resin, polyethylene-polypropylene resin, ethylene tetrafluoride resin, ethylene tetrafluoride-perfluoroalkylvinyl ether copolymer, tetrafluoride ethylene-hexafluoride propylene copolymer resin, yarn resin materials such as a fluorinated ethylene-ethylene copolymer resin, a chlorinated ethylene trifluoride-ethylene copolymer resin, a vinylidene fluoride resin, an ethylene trifluoride-chlorinated copolymer resin, and a vinyl fluoride resin; Metal materials, such as chromium and nickel, are mentioned.

As said metal material, a nickel-chromium alloy is especially preferable.

It does not restrict|limit especially as a nickel-chromium alloy, A well-known nickel-chromium alloy can be used. Especially, the nickel-chromium alloy whose nickel content is 40-75 mass % and chromium content is 1-30 mass % is preferable.

Examples of the nickel-chromium alloy include Hastelloy (trade name, hereinafter the same), Monel (trade name, hereinafter the same), and Inconel (trade name, hereinafter the same). More specifically, Hastelloy C-276 (Ni content 63 mass %, Cr content 16 mass %), Hastelloy C (Ni content 60 mass %, Cr content 17 mass %), Hastelloy C-22 (Ni content 61 mass %, Cr content 22 mass %) etc. are mentioned.

Moreover, the nickel-chromium alloy may further contain boron, a silicon, tungsten, molybdenum, copper, cobalt, etc. other than an above-described alloy as needed.

The method for electrolytic polishing the metal material is not particularly limited, and a known method can be used. For example, the method described in paragraphs [0011]-[0014] of Japanese Patent Application Laid-Open No. 2015-227501 and paragraphs [0036]-[0042] of Japanese Patent Application Laid-Open No. 2008-264929 can be used.

In addition, the said metal material may be buff-polished. The method of buffing is not particularly limited, and a known method can be used. Although the size in particular of the abrasive grain used for finishing of buffing is not restrict|limited, From the point which the unevenness|corrugation of the surface of the said metal material tends to become smaller, #400 or less is preferable.

In addition, it is preferable that buff grinding|polishing is performed before electropolishing.

[Chemical mechanical polishing method]

In the chemical mechanical polishing method according to the first embodiment of the present invention, while supplying the polishing liquid to a polishing pad mounted on a polishing platen, a polishing target surface of an object to be polished is brought into contact with the polishing pad, the polishing body and the polishing pad It is a chemical mechanical polishing method (hereinafter also referred to as a "CMP method") comprising a step (hereinafter, also referred to as a "polishing step") of obtaining a polished object by polishing the surface to be polished by relatively moving the .

[Subject to be polished]

The object to be polished to which the CMP method according to the above embodiment can be applied is not particularly limited, but an object to be polished (substrate with a metal layer) containing at least one cobalt-containing layer selected from the group consisting of cobalt and cobalt alloy is preferable. .

Although it does not restrict|limit especially as said cobalt alloy, The cobalt alloy containing nickel is preferable.

When the cobalt alloy contains nickel, the content of nickel is preferably 10 mass % or less, more preferably 1 mass % or less, more preferably 0.1 mass % or less, and 0.00001 mass % or more in the total mass of the cobalt alloy. This is preferable. The shape of the electrode may be a through-silicon electrode.

As a to-be-polished object used in the CMP method which concerns on the said embodiment, it can manufacture by the following method.

First, an interlayer insulating film such as silicon dioxide is laminated on a silicon substrate. Then, by known means such as resist layer formation and etching, recesses (exposed portions) of a predetermined pattern are formed on the surface of the interlayer insulating film to form an interlayer insulating film comprising convex portions and concave portions. As a barrier layer covering the interlayer insulating film along the surface unevenness on the interlayer insulating film, a metal or a metal nitride (for example, any one selected from the group consisting of Ta, TaN, Ti, TiN, Ru, and Mn) of metal or metal nitride), etc., is formed by vapor deposition or CVD (chemical vapor deposition). In addition, a cobalt-containing layer (hereinafter also referred to as a metal layer) consisting of at least one selected from the group consisting of cobalt and cobalt alloys, which covers the barrier layer to fill the recesses, is formed by vapor deposition, plating, CVD, etc. to form a laminate structure Obtain an object to be polished with As for the thickness of an interlayer insulating film, a barrier layer, and a metal layer, 0.01-2.0 micrometers, 1-100 nm, and about 0.01-2.5 micrometers are preferable, respectively.

It does not restrict|limit especially as a material which comprises the said barrier layer, A well-known low-resistance metal material can be used. As a low-resistance metal material, Ta, TaN, Ti, TiN, Ru, and Mn are more preferable.

(surface to be polished)

In the object to be polished used in the CMP method according to the above embodiment, the surface to be polished is not particularly limited.

In the manufacturing process of a metal wiring using the above-mentioned object to be polished, the metal atoms contained in the barrier layer and the metal atoms contained in the cobalt-containing layer have different chemical and physical properties, so CMP is usually performed in two steps. . That is, as described above, CMP is performed on the cobalt-containing layer in the first step, and CMP is performed on the barrier layer in the second step. In addition, in this first-stage CMP process, dishing in which the metal wiring is excessively polished is likely to occur, and in the second-stage CMP process, in the second-stage CMP process, the dishing and according to the dishing, the fine metal wiring is densely arranged. An erosion in which the insulating film (the insulating film is disposed between the respective metal wirings) is excessively polished is likely to occur.

[polishing device]

A polishing apparatus capable of performing the CMP method is not particularly limited, and a known chemical mechanical polishing apparatus (hereinafter also referred to as "CMP apparatus") can be used.

The CMP apparatus includes, for example, a holder for holding an object to be polished (eg, a semiconductor substrate, etc.) having a surface to be polished, and a polishing platen to which a polishing pad is attached (a motor having a variable rotational speed is mounted). A general CMP apparatus that does this can be used. As a commercial item, Reflexion (made by Applied Materials) can be used, for example.

<polishing pressure>

In the CMP method according to the embodiment, the polishing is preferably performed at a pressure of 3000 to 25000 Pa, that is, the pressure generated on the contact surface between the surface to be polished and the polishing pad, and more preferably at 6500 to 14000 Pa.

<The number of rotations of the polishing plate>

In the CMP method according to the embodiment, it is preferable that the rotation speed of the polishing platen is 50 to 200 rpm, and it is more preferable to polish it at 60 to 150 rpm.

In order to relatively move the polishing body and the polishing pad, the holder may be further rotated and/or oscillated, the polishing surface may be planetary rotated, or the belt-shaped polishing pad may be moved linearly in one direction in the long direction. Note that the holder may be in any state of being fixed, rotating, or oscillating. These polishing methods can be appropriately selected depending on the surface to be polished and/or the polishing apparatus as long as the polishing body and the polishing pad are relatively moved.

<Supply method of polishing liquid>

In the CMP method according to the embodiment, a polishing liquid is continuously supplied by a pump or the like to the polishing pad on the polishing platen while the surface to be polished is polished. Although there is no limitation on this supply amount, it is preferable that the surface of a polishing pad is always covered with a polishing liquid. In addition, it is as above about the aspect of a polishing liquid.

The CMP method according to the embodiment may further include the following steps before the polishing step.

As said process, the process of mixing water with respect to the grinding|polishing liquid stock solution containing colloidal silica of association degree 1-3, an organic acid, an azole compound, and hydrogen peroxide, for example is mentioned, for example. In addition, the aspects of the polishing liquid, the polishing liquid stock solution, and the concentrated liquid are the same as described above.

Example

The present invention will be described in more detail below based on examples. Materials, usage amounts, ratios, treatment details, treatment procedures, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the Examples shown below. In addition, "%" means "mass %" and "ppb" means "mass ppb" unless otherwise specified.

[Refining of raw materials, etc.]

Each raw material and each catalyst used in each Example shown below uses a high-purity grade of 99 mass % or more, Furthermore, it refine|purifies in advance by distillation, ion exchange, filtration, etc.

The ultrapure water used for preparation of each polishing liquid was refine|purified by the method described in Unexamined-Japanese-Patent No. 2007-254168. Then, it was used after confirming that the content of each element of Na, Ca, and Fe was less than 10 mass ppt with respect to the total mass of each chemical|medical solution by the measurement by the SNP-ICP-MS method mentioned later.

Preparation, filling, storage, and analysis of the polishing liquids of Examples and Comparative Examples were all performed in a clean room at a level satisfying ISO class 2 or lower. In addition, the container used in each Example and a comparative example was used after washing|cleaning with the polishing liquid of each Example or a comparative example. In order to improve the measurement precision, the measurement of the metal content and the water content are measured by concentrating to 1/100 of the volume in terms of volume, and the concentration of the polishing liquid before concentration is measured for those that are below the detection limit in normal measurement. In conversion to , the content was calculated.

[Example 1A]

Each component shown below was mixed, and the chemical mechanical polishing liquid was prepared.

・Colloidal silica (degree of association: 2, average primary particle diameter: 35 nm, product name “PL3”, manufactured by Fuso Chemical Industries, Ltd.) 0.1% by mass

・Glycine (corresponding to amino acid) 1.5% by mass

0.001 mass % of 5-methylbenzotriazole (corresponding to an azole compound containing a benzotriazole skeleton)

0.2 mass % of 3-amino-1,2,4-triazole (corresponding to a compound not containing a benzotriazole skeleton and also a compound containing a 1,2,4-triazole skeleton)

· Hydrogen peroxide (corresponding to an oxidizing agent) 1.0% by mass

・Ethylene glycol (corresponding to an organic solvent, partly used as a solvent for dissolving 5-methylbenzotriazole) 0.05% by mass

・Water (pure water) balance

In addition, the pH of the polishing liquid in Table 1 was adjusted so that it might become a predetermined value using sulfuric acid and/or potassium hydroxide as needed.

In addition, in this Example, "Table 1" refers to Table 1A1, Table 1A2, Table 1B1, Table 1B2, Table 1C1, Table 1C2, Table 1D1, Table 1D2.

[Examples 2A to 83A, Comparative Examples 1A to 5A]

Each component shown in Table 1 was mixed by the method similar to Example 1A, and each polishing liquid was obtained. In addition, each symbol in Table 1 shows the following compounds, etc.

・PL3 (colloidal silica, product name "PL3", manufactured by Fuso Chemical Industries, Ltd., degree of association: 2, average primary particle diameter: 35 nm)

・PL2 (colloidal silica, product name "PL2", manufactured by Fuso Chemical Industries, Ltd., degree of association: 2, average primary particle diameter: 25 nm)

・PL3L (colloidal silica, product name "PL3L", manufactured by Fuso Chemical Industries, Ltd., degree of association: 1, average primary particle diameter: 35 nm)

・PL3H (colloidal silica, product name “PL3H”, manufactured by Fuso Chemical Industries, Ltd., degree of association: 3, average primary particle diameter: 35 nm)

・ST-PS-MO (colloidal silica, product name "ST-PS-MO", manufactured by Nissan Chemical Industry Co., Ltd., degree of association: more than 3, average primary particle diameter: 20 nm)

Gly (Glycine, corresponding to amino acids)

Ala (corresponds to alanine, amino acid)

Asp (corresponding to aspartic acid, amino acid)

·NMG (N-methylglycine, corresponding to amino acid)

·5-MBTA (5-methylbenzotriazole, corresponding to an azole compound containing a benzotriazole skeleton)

BTA (corresponding to benzotriazole, azole-based compound containing benzotriazole skeleton)

5,6-DMBTA (corresponding to 5,6-dimethylbenzotriazole, an azole compound containing a benzotriazole skeleton)

·5-ABTA (corresponding to 5-aminobenzotriazole, azole-based compound containing a benzotriazole skeleton)

·3-AT (corresponds to azole compounds not containing 3-amino-1,2,4-triazole and benzotriazole skeletons, and also azole compounds containing 1,2,4-triazole skeletons)

1,2,4-Tri (corresponds to azole compounds not containing 1,2,4-triazole and benzotriazole skeletons, and azole compounds containing 1,2,4-triazole skeletons)

·3,5-DP (corresponding to azole compounds not containing 3,5-dimethylpyrazole and benzotriazole skeletons, and azole compounds containing pyrazole skeletons (pyrazole compounds))

Pyraz (corresponds to azole compounds that do not contain pyrazole or benzotriazole skeletons, and also azole compounds that contain pyrazole skeletons)

・Imidaz (corresponds to azole compounds not containing imidazole or benzotriazole skeletons, and azole compounds containing imidazole skeletons (imidazole compounds))

·5-ATZ (corresponds to azole compounds that do not contain a 5-aminotetrazole or benzotriazole skeleton)

ETG (Ethylene Glycol, corresponding to organic solvents)

EtOH (corresponding to ethanol and organic solvents)

PG (Propylene glycol, corresponding to organic solvents)

·4-HA (4-hydroxybenzoic acid, corresponding to organic acid)

·2-HA (2-hydroxybenzoic acid, corresponding to organic acid)

PA (corresponding to phthalic acid and organic acid)

·SA (corresponding to salicylic acid, organic acid)

·Ant (corresponding to anthranilic acid, organic acid)

·TMT (corresponding to trimellitic acid, organic acid)

·N-cocoyl sarcosinate (corresponding to N-cocoyl sarcosinate, cobalt anticorrosive)

N-lauroyl sarcosinate (N-lauroyl sarcosinate, corresponding to cobalt anticorrosive)

·N-oleoyl sarcosinate (N-oleoyl sarcosinate, corresponding to cobalt anticorrosive)

N-myristoyl sarcosinate (corresponding to myristoyl sarcosinate, cobalt anticorrosive agent)

·N-myristoyl glycine (N-myristoyl glycine, corresponding to cobalt anticorrosive)

·N-stearoyl sarcosinate (corresponding to N-stearoyl sarcosinate, cobalt anticorrosive agent)

·N-lauroyl glycine (corresponding to N-lauroyl glycine, cobalt anticorrosive)

·N-palmitoyl glycine (N-palmitoyl glycine, corresponding to cobalt anticorrosive)

N-lauroyl glutamate (N-lauroyl glutamate, corresponding to cobalt anticorrosive)

·N-cocoyl glutamate (corresponding to N-cocoyl glutamic acid, cobalt anticorrosive)

Potassium N-cocoyl glutamate (corresponding to potassium N-cocoyl glutamate, cobalt anticorrosive)

Potassium N-lauroyl sarcosinate (corresponding to potassium N-lauroyl sarcosinate, cobalt anticorrosive)

·N-lauroyl alaninate (corresponding to N-lauroyl alaninate, cobalt anticorrosive)

N-myristoyl alaninate (corresponding to N-myristoyl alaninate, cobalt anticorrosive)

Potassium N-cocoyl alaninate (corresponding to potassium N-cocoyl alaninate, cobalt anticorrosive)

RE-610 (Product name "Rhodafac RE-610", manufactured by Rhodia, corresponds to surfactant)

・MD-20 (product name "Surfynol MD-20", manufactured by Air Products, corresponds to a surfactant)

DBSH (dodecylbenzenesulfonic acid, corresponding to surfactant)

PHEAA (N-(2-hydroxyethyl) acrylamide polymer, weight average molecular weight 20000, corresponds to hydrophilic polymer)

·PAA (corresponding to polyacrylic acid, hydrophilic polymer)

PEIEO (polyethylenimine having an ethyleneoxy chain having a repeating unit represented by the following formula, HLB value 18)

[Formula 2]

[Example 1B]

Each component shown below was mixed, and the chemical mechanical polishing liquid was prepared.

· Colloidal silica (degree of association: 2, average primary particle diameter: 35 nm, product name "PL3", manufactured by Fuso Chemical Industries, Ltd.) 3.0% by mass

・CA (corresponding to citric acid and organic acid) 0.003% by mass

·Male (corresponding to maleic acid and organic acid) 0.05% by mass

・benzotriazole (corresponding to an azole compound containing a benzotriazole skeleton) 0.1% by mass

0.05 mass % of 3-amino-1,2,4-triazole (corresponding to a compound not containing a benzotriazole skeleton and also a compound containing a 1,2,4-triazole skeleton)

· Hydrogen peroxide (corresponding to an oxidizing agent) 1.0% by mass

・Ethylene glycol (corresponding to an organic solvent, partly used as a solvent for dissolving 5-methylbenzotriazole) 0.05% by mass

・Water (pure water) balance

In addition, the pH of the polishing liquid in Table 2 was adjusted so that it might become a predetermined value using sulfuric acid and/or potassium hydroxide as needed.

In addition, in this Example, "Table 2" refers to Table 2A1, Table 2A2, Table 2A3, Table 2B1, Table 2B2, Table 2B3, Table 2C1, Table 2C2, Table 2C3, Table 2D1, Table 2D2, Table 2D3 .

[Examples 2B to 82B, Comparative Examples 1B to 3B]

Each component shown in Table 2 was mixed by the method similar to Example 1B, and each polishing liquid was obtained. Each abbreviation in Table 2 shows the following compounds, etc. In addition, in each abbreviation in Table 2, it is as above-mentioned about the thing similar to the abbreviation in Table 1.

CA (corresponding to citric acid and organic acid)

·Succinic acid (corresponding to organic acid)

Malic acid (corresponding to organic acid)

・Malonic acid (corresponding to organic acid)

Male (corresponding to maleic acid and organic acid)

[Measurement of average particle size (T2) of colloidal silica before and after CMP]

The average particle diameter of the colloidal silica before and after CMP was measured by the following method, and the average particle diameter (T2) of the colloidal silica before and behind CMP was calculated|required by following formula (2). A result is shown in Table 1 and Table 2.

≪Measurement conditions≫

The particle size distribution of the abrasive grains in the polishing liquid before CMP was measured using the particle size distribution meter SALD-2300 (made by Shimadzu Corporation), and the average particle diameter was calculated|required. Moreover, the polishing liquid after CMP was recovered, and the average particle diameter was calculated|required by the same method also about the abrasive grain in the polishing liquid after the said collection|recovery. Using the obtained numerical value, T2 obtained from the following formula was computed.

Equation (2):

T2 = average particle diameter after chemical mechanical polishing / average particle diameter before chemical mechanical polishing

[Measurement of thickness of reaction layer]

<Measurement of the thickness of the reaction layer when the model film of cobalt is used as the surface to be polished>

A silicon substrate on which cobalt having a thickness of 1500 nm was deposited was cut to about 10 mm square, and placed in a polyethylene cup having an internal volume of about 100 mL in which 10 mL of the above-mentioned polishing liquid was placed, and left still at room temperature (about 25° C.) for 24 hours and immersed. After immersion, the sample taken out from the grinding|polishing liquid was washed with water, and also it air-dried using nitrogen, and obtained the sample in which the reaction layer was formed in the cobalt surface.

This sample was subjected to cross-section forming by a focused ion beam processing apparatus (FIB) and cross-sectional observation by a scanning electron microscope (SEM) under the measurement conditions shown below to measure the thickness of the reaction layer. The results are shown in Tables 1 and 2.

(FIB processing conditions)

Apparatus: FB-2000A model manufactured by Hitachi Seisakusho Co., Ltd.

Acceleration voltage: 30kV

Pretreatment: Platinum sputter coating → Carbon deposition → Tungsten deposition

(SEM measurement conditions)

Apparatus: S-900 type manufactured by Hitachi Seisakusho Co., Ltd.

Acceleration voltage: 3kV

Pretreatment: Platinum Sputter Coating

<Measurement of thickness of reaction layer when any one model film selected from the group consisting of Ta, TaN, Ti, TiN, Ru, and Mn is used as the surface to be polished>

A silicon substrate having a 1500 nm-thick Ta deposited thereon was cut to about 10 mm square, and placed in a polyethylene cup having an internal volume of about 100 mL in which 10 mL of the above-mentioned polishing liquid was placed, and left still at room temperature (about 25° C.) for 24 hours and immersed. After immersion, the sample taken out from the polishing liquid was washed with water and further air-dried using nitrogen to obtain a sample in which a reaction layer was formed on the Ta surface.

This sample was subjected to cross-section forming by a focused ion beam processing apparatus (FIB) and cross-sectional observation by a scanning electron microscope (SEM) under the measurement conditions shown below to measure the thickness of the reaction layer. The results are shown in Tables 1 and 2.

Also, for each metal of TaN, Ti, TiN, Ru, and Mn, a model film was produced in the same manner as above, and the thickness of each reaction layer was measured (the results are shown in Tables 1 and 2).

<Measurement of thickness of reaction layer when any one model film selected from the group consisting of SiOx and SiOC is used as the surface to be polished>

A silicon substrate on which SiOx having a thickness of 1500 nm was deposited was cut to about 10 mm square, and placed in a polyethylene cup having an internal volume of about 100 mL in which 10 mL of the above-described polishing liquid was placed, and left still at room temperature (about 25° C.) for 24 hours and immersed. After immersion, the sample taken out from the polishing liquid was washed with water and further air-dried using nitrogen to obtain a sample in which a reaction layer was formed on the SiOx surface.

This sample was subjected to cross-section forming by a focused ion beam processing apparatus (FIB) and cross-sectional observation by a scanning electron microscope (SEM) under the measurement conditions shown below to measure the thickness of the reaction layer. The results are shown in Table 2.

Also, for SiOC, a model film was produced in the same manner as above, and the thickness of the reaction layer was measured (results are shown in Table 2).

[Various quantities]

<Content of compound represented by general formula (1)>

The content of the compound represented by the general formula (1) contained in the polishing liquids produced in each Example and Comparative Example was measured using a gas chromatograph mass spectrometer (product name "GCMS-2020", manufactured by Shimadzu Corporation). did. Measurement conditions are shown below.

In addition, the quantitative measurement by a gas chromatograph mass spectrometer was performed using the sample which added hydrogen fluoride to a polishing liquid, melt|dissolved abrasive grain completely, and adjusted the pH to 10 or more after that.

≪Measurement conditions≫

Capillary column: InertCap 5MS/NP 0.25mmI.D. ×30m df=0.25μm

Sample introduction method: Split 75 kPa pressure constant

Vaporization chamber temperature: 230℃

Column oven temperature: 80°C (2min)-500°C (13min) Temperature increase rate 15°C/min

Carrier Gas: Helium

Septum purge flow: 5 mL/min

Split Ratio: 25:1

Interface temperature: 250℃

Ion source temperature: 200℃

Measurement mode: Scan m/z=85~500

Sample introduction amount: 1 μL

<Content of specific metal atoms>

(Content of specific metal atoms contained in metal impurities)

The content of specific metal atoms contained in the metal impurities in the polishing liquids prepared in Examples and Comparative Examples was measured using an Agilent 8800 triple quadrupole ICP-MS (for semiconductor analysis, option #200).

≪Measurement conditions≫

The sample introduction system used a quartz torch, a coaxial PFA (perfluoroalkoxyalkane) nebulizer (for self-priming), and a platinum interface cone. The measurement parameters of the cool plasma conditions are as follows.

RF (Radio Frequency) output (W): 600

・Carrier gas flow rate (L/min): 0.7

・Makeup gas flow rate (L/min): 1

·Sampling depth (mm): 18

(Content of specific metal atoms contained in metal particles)

Measurement by SNP-ICP-MS (Single Nano Particle-Inductively Coupled Plasma-Mass Spectrometry)

About the content rate of the specific metal atom contained in a metal particle, it measured using "Nexion350S" manufactured by Perkinelmer.

In addition, quantification by SNP-ICP-MS was performed using the sample which added hydrogen fluoride to the grinding|polishing liquid, melt|dissolved abrasive grain completely, and adjusted the pH to 10 or more after that.

1) Preparation of standard materials

As a standard substance, ultrapure water is metered into a clean glass container, and after adding the metal particles to be measured with a median diameter of 50 nm to a concentration of 10000/ml, the dispersion treated with an ultrasonic cleaner for 30 minutes is used as a standard substance for transport efficiency measurement was used as

2) Measurement conditions

Using a coaxial nebulizer made from PFA, a cyclone spray chamber made from quartz, and a torch injector made from quartz with an inner diameter of 1 mm, the measurement target solution was aspirated at about 0.2 mL/min. The amount of oxygen added was 0.1 L/min, plasma output of 1600 W, and cell purging was performed with ammonia gas. Time resolution was analyzed with 50 us.

3) Content of the specific metal atom contained in a metal particle was measured using the following analysis software attached to a manufacturer.

・Content of specific metal atoms contained in metal particles: Syngistix nano application module dedicated to nanoparticle analysis "SNP-ICP-MS"

[Grinding speed, dishing evaluation, and erosion evaluation]

Polishing was performed while supplying the polishing liquid to the polishing pad under the following conditions, and the polishing rate and dishing were evaluated for Examples 1A to 83A and Comparative Examples 1A to 5A, and for Examples 1B to 82B, the polishing rate, dishing and The previous evaluation was performed.

・Abrasive device: Reflexion (manufactured by Applied Materials)

・Object to be polished (wafer):

(1) for calculating the polishing rate; A blanket wafer having a diameter of 300 mm in which each of the above model films (Co film, Ta film, SiOx film, TaN film, Ti film, TiN film, Mn film, Ru film, or SiOC film) having a thickness of 1.5 µm is formed on a silicon substrate.

(2) for dishing evaluation;

Examples 1A to 83A, Comparative Examples 1A to 5A:

After stacking an insulating layer made of SiOx with a thickness of 5000 Å on a substrate with a pattern of cobalt wiring (manufactured by International SEMATECH, a silicon substrate), pattern processing is performed with a “SEMATECH 854” mask (L/S = 10 μm/10 μm), and the thickness is applied thereon A test substrate in which a barrier metal layer of 100 Å (barrier metal: Ta) and a cobalt layer of 7500 Å in thickness are sequentially stacked.

· Examples 1B-82B:

After stacking an insulating layer made of SiOx with a thickness of 5000 Å on a substrate with a pattern of cobalt wiring (manufactured by International SEMATECH, a silicon substrate), pattern processing is performed with a “SEMATECH 854” mask (L/S = 10 μm/10 μm), and the thickness is applied thereon A test substrate in which a barrier metal layer of 100 Å (barrier metal: Ta) and a cobalt layer of 7500 Å in thickness are sequentially stacked.

(3) for erosion evaluation;

An insulating layer made of SiOx is laminated with a thickness of 5000 Å on a substrate with a cobalt wiring pattern (manufactured by International SEMATECH, a silicon substrate), and then patterned with a “SEMATECH 854” mask (L/S=9 μm/1 μm), and the thickness is applied thereon A test substrate in which a barrier metal layer of 100 Å (barrier metal: Ta) and a cobalt layer of 7500 Å in thickness are sequentially stacked.

・Abrasive pad: IC1010 (manufactured by Rhodel)

· grinding conditions;

Polishing pressure (contact pressure between the surface to be polished and the polishing pad): 1.5 psi (In addition, in this specification, psi means pound-force per square inch; means square inch per pound of weight, and 1 psi=6894.76 Pa is intended. )

Abrasive fluid supply rate: 200ml/min

Grinding plate rotation speed: 110rpm

Grinding head rotation speed: 100rpm

(Assessment Methods)

Examples 1A to 83A, Comparative Examples 1A to 5A:

Calculation of polishing rate: The blanket wafer of (1) is polished for 60 seconds, and the metal film thickness before and after polishing is obtained by converting the electrical resistance value at 49 equally spaced locations on the wafer surface, and dividing them by the polishing time The average value of the calculated|required values was made into the polishing rate (unit: nm/min).

Evaluation of dishing: With respect to the pattern wafer of (2), in addition to the time until the cobalt of the non-wiring portion is completely polished, additional polishing is performed only for 20% of the time, and the line and space portion (line 10 µm) , space 10 µm) was measured with a contact-type step meter DektakV320Si (manufactured by Veeco), and evaluated according to the following standards. In addition, evaluation "G" or more is a practical use range.

A: The dishing is 5 nm or less.

B: The dishing is more than 5 nm and 8 nm or less.

C: The dishing is more than 8 nm and 12 nm or less.

D: The dishing is more than 12 nm and 15 nm or less.

E: The dishing is more than 15 nm and 18 nm or less.

F: The dishing is more than 18 nm and 21 nm or less.

G: The dishing is more than 21 nm and 25 nm or less.

H: The dishing is more than 25 nm.

- Examples 1B to 82B, Comparative Examples 1B to 3B:

Calculation of polishing rate: The blanket wafer of (1) is polished for 60 seconds, and the metal film thickness before and after polishing is obtained by converting the electrical resistance value at 49 equally spaced locations on the wafer surface, and dividing them by the polishing time The average value of the calculated|required values was made into the polishing rate (unit: nm/min).

Evaluation of dishing: With respect to the pattern wafer of (2), in addition to the time until the cobalt of the non-wiring portion is completely polished, additional polishing is performed only for 20% of the time, and the line and space portion (line 10 µm) , space 10 µm) was measured with a contact-type step meter DektakV320Si (manufactured by Veeco), and evaluated according to the following standards. In addition, evaluation "G" or more is a practical use range.

A: The dishing is 5 nm or less.

B: The dishing is more than 5 nm and 8 nm or less.

C: The dishing is more than 8 nm and 12 nm or less.

D: The dishing is more than 12 nm and 15 nm or less.

E: The dishing is more than 15 nm and 18 nm or less.

F: The dishing is more than 18 nm and 21 nm or less.

G: The dishing is more than 21 nm and 25 nm or less.

H: The dishing is more than 25 nm.

Evaluation of Erosion: With respect to the pattern wafer of (3), in addition to the time until the cobalt of the non-wiring portion is completely polished, polishing is performed additionally for an additional 1 minute, and the line-and-space portion (line 9 µm, space 1 µm) is The step was measured with a contact-type step meter DektakV320Si (manufactured by Veeco), and evaluated according to the following standards. In addition, evaluation "G" or more is a practical use range.

A: The erosion transition is 3 nm or less.

B: The erosion transition is more than 3 nm and 5 nm or less.

C: Erosion is more than 5 nm and 10 nm or less.

D: The erosion transition is more than 10 nm and 15 nm or less.

E: The erosion transition is more than 15 nm and 20 nm or less.

F: Erosion is more than 20 nm and 25 nm or less.

G: Erosion is more than 25 nm and 30 nm or less.

H: The erosion is more than 30 nm.

[Defect Evaluation]

The evaluation (60 nm or more) of the defect of the polishing liquid was performed by ComPlus (a defect inspection apparatus manufactured by AMAT) for the pattern wafer which was performed until the finish grinding|polishing.

A: The number of defects after polishing is 20 pieces/Wf or less

B: The number of defects after polishing is greater than 20/Wf and less than or equal to 30/Wf

C: The number of defects after polishing is greater than 30/Wf and less than or equal to 50/Wf

D: The number of defects after polishing, more than 50 pieces/Wf, and less than 60 pieces/Wf

E: The number of defects after polishing, more than 60 pieces/Wf, 80 pieces/Wf or less

F: The number of defects after polishing, more than 80/Wf and less than 100/Wf

G: The number of defects after polishing is greater than 100/Wf and less than or equal to 120/Wf

H: The number of defects after polishing exceeds 120/Wf

[Evaluation of stability over time]

Each polishing liquid was stored at 40°C for 1 month. Using a particle size distribution meter SALD-2300 (manufactured by Shimadzu Corporation), each particle size distribution (average particle diameter) of the abrasive particles immediately after preparation (initial) and after storage was measured to obtain each average particle diameter from the following formula According to the calculated ratio, the temporal stability of the polishing liquid was evaluated.

Formula (6): T3 = average particle diameter of abrasive particles after storage / average particle diameter of initial abrasive particles

A: T3 is 1.1 or less

B: T3 greater than 1.1 and less than or equal to 1.3

C: T3 greater than 1.3, less than or equal to 1.5

D: T3 >1.5

A result is shown in Table 1 and Table 2.

In addition, in a table|surface, "%" and "ppb" are both based on mass.

In addition, "polishing speed ratio R1", "polishing speed ratio R2", and "polishing speed ratio R3" are values calculated from the following formulas (3) to (5), respectively.

Equation (3):

R1 = polishing rate of the cobalt substrate by the polishing liquid / polishing rate of the barrier substrate by the polishing liquid

Equation (4):

R2 = polishing rate of the cobalt substrate by the polishing liquid / polishing rate of the barrier substrate by the polishing liquid

Equation (5):

R3 = polishing rate of cobalt substrate by polishing liquid/ polishing rate of insulating film substrate by polishing liquid

In addition, the "metal impurity amount" intends the content of a specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms with respect to the total mass of the polishing liquid.

In addition, the "metal particle amount" refers to the content of a specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms contained in the solid metal impurities among the metal impurities relative to the total mass of the polishing liquid. is intended to

_In addition, "H2O2/metal impurity amount (T1)" is a value computed from following formula ( ₁ ).

Formula (1): T1 = content of hydrogen peroxide/total content of specific metal atoms selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms contained in metallic impurities

In addition, "amine amount (ppb)" intends content with respect to the total mass of a polishing liquid of the compound represented by General formula (1) mentioned above.

In addition, the polishing liquid was adjusted with water (balance) so that the total mass might be 100 mass %.

In addition, in Table 1 below, Table 1A2, Table 1B2, Table 1C2, and Table 1D2 are each of Examples 1A to 83A and Comparative Examples 1A to 5A shown in Table 1A1, Table 1B1, Table 1C1, and Table 1D1, respectively. Various evaluation results for the polishing liquid are shown.

That is, for example, in the case of Example 1A, various evaluations using the polishing liquid of Table 1A1 are shown in Table 1A2. The thickness of the Co reaction layer in the polishing liquid of Example 1A is 4 nm, dishing evaluation is 4 nm (corresponding to A), defect evaluation is A, and aging stability is A. Further, for example, when the barrier metal is TaN, the thickness of the TaN reaction layer is 0.08 nm.

In addition, in Table 2 below, Table 2A2 and Table 2A3, Table 2B2 and Table 2B3, Table 2C2 and Table 2C3, Table 2D2, and Table 2D3 are Examples 1B to Table 2A1, Table 2B1, Table 2C1, respectively. The various evaluation results about each polishing liquid of 82B and Comparative Examples 1B - 3B are shown.

That is, for example, in the case of Example 1B, in Table 2A2 and Table 2A3, various evaluation using the polishing liquid of Table 2A1 appears. The thickness of the Co reaction layer in the polishing liquid of Example 1B is 1 nm, dishing evaluation is 3.5 nm (corresponding to A), erosion evaluation is 8.75 nm (corresponding to C), defect evaluation is A, stability with time is A to be. Further, for example, when the barrier metal is TaN, the thickness of the TaN reaction layer is 0.212 nm.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

[Table 10]

[Table 11]

[Table 12]

[Table 13]

[Table 14]

[Table 15]

[Table 16]

[Table 17]

[Table 18]

[Table 19]

[Table 20]

From the results of Tables 1 and 2, it was confirmed that, in all of the polishing liquids of Examples, dishing, erosion, and generation of defects on the surface to be polished were suppressed. Moreover, it was confirmed that it was also excellent in temporal stability.

On the other hand, in the polishing liquids of Comparative Examples 1 to 5, dishing and generation of defects on the surface to be polished were confirmed.

・Results of Examples 1A to 83A (Table 1)

From the comparison between Examples 1A and 8A to 11A, when the content of hydrogen peroxide is 0.001 to 2.5 mass % (preferably 0.06 to 2 mass %) with respect to the total mass of the polishing liquid, dishing occurs more on the surface to be polished It turned out to be difficult to do.

Further, from the comparison between Examples 1A and 12A to 15A, when the content of the azole compound is 0.01 to 1.3 mass% (preferably 0.01 to 0.4 mass%) with respect to the total mass of the polishing liquid, the surface to be polished It was confirmed that dishing was more difficult to occur, and stability with time was more excellent.

From the comparison of Examples 1A and 19A to 21A, when the ratio T2 of the average particle diameter before and after chemical mechanical polishing of the colloidal silica of the association degrees 1 to 3 is 2.5 or less (preferably 2 or less), the surface to be polished It was confirmed that the defect is more difficult to occur.

Further, from the comparison of Examples 1A and 22A to 25A, when the pH of the polishing liquid is 6.5 to 8.0 (preferably 6.8 to 7.8, more preferably 6.8 to 7.2), dishing and defects on the surface to be polished are It was more difficult to generate|occur|produce and it was confirmed that it was more excellent in temporal stability. Moreover, from the comparison between Examples 1A and 26A to 29A, the content of the compound represented by the general formula (1) is 1000 mass ppb or less (preferably 250 mass ppb or less, more preferably 250 mass ppb or less with respect to the total mass of the polishing liquid) 8 mass ppb or less), it was confirmed that dishing and defects on the surface to be polished were less likely to occur, and stability with time was more excellent.

Further, from the comparison between Examples 1A and 30A to 32A, the content of one specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms contained in the metal impurities is determined by the total mass of the polishing liquid. In the case of 0.01 to 100 mass ppb (preferably 0.01 to 50 mass ppb, more preferably 0.01 to 20 mass ppb), dishing and defects on the surface to be polished are less likely to occur, and stability over time is better it was confirmed Moreover, when it is a specific metal atom contained in a metal particle, and the content is 0.01-50 mass ppb (preferably 0.01-8 mass ppb) with respect to the total mass of a polishing liquid, dishing and defects on the to-be-polished surface It was more difficult to generate|occur|produce and it was confirmed that it was more excellent in temporal stability.

Moreover, from the comparison with Examples 1A, 33A to 35A, 54A, and 55A, when the amino acid content is 0.8 to 4 mass % with respect to the total mass of the polishing liquid, dishing and defects on the surface to be polished are less likely to occur. , it was confirmed that the stability over time was more excellent.

Moreover, from the comparison between Examples 1A and 36A to 38A, when glycine or N-methylglycine (preferably glycine) was contained as an amino acid, it was confirmed that dishing on the surface to be polished was more difficult to occur.

Further, from the comparison between Examples 1A, 57A, and 58A, when the content of colloidal silica of the association degrees 1 to 3 is 0.01 to 0.15 mass % with respect to the total mass of the polishing liquid, dishing on the surface to be polished is more likely to occur. It turned out to be difficult.

Further, from the comparison between Examples 1A and 39A to 53A, when a polishing liquid containing a compound having a benzotriazole skeleton and a compound different from the benzotriazole compound is applied to CMP, dishing occurs more on the polished surface It turned out to be difficult to do.

Further, from the comparison of Examples 1A, 8A to 11A, and 30A to 32A, the polishing liquid contains a specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms contained in hydrogen peroxide and metal impurities; When the content ratio T1 of is 30000 to 500000 (preferably 30000 to 110000, more preferably 30000 to 80000), it was confirmed that dishing on the surface to be polished is more difficult to occur.

From the comparison with Examples 1A and 39A to 41A, when 5-methylbenzotriazole was contained as a compound having a benzotriazole skeleton, it was confirmed that dishing on the surface to be polished was more difficult to occur.

・Results of Examples 1B to 82B (Table 2)

From the comparison of Examples 1B and 8B to 10B, when the content of hydrogen peroxide is 0.1 to 1.2 mass % (preferably 0.6 to 1 mass %) with respect to the total mass of the polishing liquid, the surface to be polished is subjected to dishing and erosion more difficult to occur than metastasis.

Moreover, from the comparison between Examples 1B and 11B to 14B, the content of the azole compound is 0.12 to 3.5 mass% (preferably 0.12 to 0.8 mass%, more preferably 0.12 to 0.5 mass%) with respect to the total mass of the polishing liquid. %), dishing and erosion on the surface to be polished are less likely to occur, and stability over time is more excellent.

From the comparison of Examples 1B and 18B to 20B, when the ratio T2 of the average particle diameter before and after chemical mechanical polishing of the colloidal silica of the association degrees 1 to 3 is 2.5 or less (preferably 2 or less), the surface to be polished It was confirmed that the defect is more difficult to occur.

Further, from the comparison of Examples 1B and 21B to 23B, when the pH of the polishing liquid is 8.2 to 9.5 (preferably 8.7 to 9.5), dishing and erosion and defects on the surface to be polished are more difficult to occur. Confirmed.

Moreover, from the comparison of Examples 1B and 24B to 27B, the content of the compound represented by the general formula (1) is 1000 mass ppb or less (preferably 250 mass ppb or less, more preferably 250 mass ppb or less with respect to the total mass of the polishing liquid) 8 mass ppb or less), it was confirmed that dishing and erosion and defects on the surface to be polished were less likely to occur, and stability with time was more excellent.

Further, from the comparison between Examples 1B and 28B to 30B, the content of one specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms contained in the metal impurities is determined by the total mass of the polishing liquid. In the case of 0.01 to 100 mass ppb (preferably 0.01 to 20 mass ppb), it was confirmed that dishing and erosion and defects on the surface to be polished were more difficult to occur, and stability with time was more excellent. Moreover, when it is a specific metal atom contained in a metal particle, and the content is 0.01-50 mass ppb (preferably 0.01-8 mass ppb) with respect to the total mass of a polishing liquid, dishing and erosion on the to-be-polished surface and It was confirmed that a defect was more difficult to generate|occur|produce and it was more excellent in stability with time.

Moreover, from the comparison between Examples 1B and 31B to 36B, when the content of the organic acid is 0.01 to 0.3 mass % with respect to the total mass of the polishing liquid, dishing and erosion and defects on the surface to be polished are more difficult to occur, and over time It was confirmed that the stability was more excellent.

Further, from the comparison of Examples 1B and 37B to 39B, when a combination of maleic acid and citric acid or malonic acid is used as an organic acid (preferably, a combination of maleic acid and citric acid is used), dishing on the surface to be polished and It was confirmed that it was more difficult to generate|occur|produce than metastasis and was more excellent in stability with time.

From the comparison of Examples 1B and 40B to 42B, when benzotriazole, 5-aminobenzotriazole, or 5,6-dimethylbenzotriazole is contained as a compound having a benzotriazole skeleton, It was confirmed that dishing and erosion are more difficult to occur.

Further, from the comparison of Examples 1B, 40B to 48B, 52B, and 53B, when a polishing liquid containing a compound having a benzotriazole skeleton as an azole compound and a compound different from the benzotriazole compound is applied to CMP , it was confirmed that dishing and erosion are less likely to occur on the surface to be polished.

Further, from the comparison of Examples 1B, 55B, and 56B, when the content of colloidal silica having an association degree of 1 to 3 is 0.5 to 3 mass% with respect to the total mass of the polishing liquid, dishing and erosion occur more on the surface to be polished It turned out to be difficult to do.

Further, from the comparison of Examples 1B, 8B to 10B, and 28B to 30B, the polishing liquid contains a specific metal atom selected from the group consisting of an Fe atom, Cu atom, Ag atom, and Zn atom contained in hydrogen peroxide and metallic impurities; When the content ratio T1 of is 30000 to 500000 (preferably 100000 to 500000, more preferably 250000 to 500000), it was confirmed that dishing and erosion are more difficult to occur on the surface to be polished.

[Example 84A]

Example 84A was prepared by the method similar to Example 1A except having carried out each component as shown in Table 3. In addition, Example 84A corresponds to a grinding|polishing liquid undiluted|stock solution.

Moreover, the polishing liquid of Example 84A was diluted 10-fold using water as a diluent.

The pH change before and after dilution was 0.01, and it was confirmed that there was no difference in the performance of the polishing liquid before and after dilution.

[Example 85A]

Example 85A was prepared by the method similar to Example 1A except having carried out each component as shown in Table 3. In addition, Example 85A corresponds to a grinding|polishing liquid undiluted|stock solution.

Further, the polishing liquid of Example 85A was diluted 50 times using water as a diluent.

The pH change before and after dilution was 0.1, and it was confirmed that there was no difference in the performance of the polishing liquid before and after dilution.

[Table 21]

[Example 1B(A) to Example 1B(E)]

The same evaluation as in Example 1B was performed using the polishing liquid of Example 1B, except that the substrate for dishing evaluation and the test substrate for erosion evaluation were replaced with the following ones. The result is shown in Tables 4-8 as Example 1B(A) - Example 1B(E), respectively.

(1) for dishing evaluation;

After stacking an insulating layer made of SiOx with a thickness of 5000 Å on a substrate with a pattern of cobalt wiring (manufactured by International SEMATECH, a silicon substrate), pattern processing is performed with a “SEMATECH 854” mask (L/S = 10 μm/10 μm), and the thickness is applied thereon A test substrate in which a 100 Å barrier metal layer (barrier metal: TaN, Ti, TiN, Ru, or Mn) and a 7500 Å thick cobalt layer are sequentially stacked.

(2) for erosion evaluation;

An insulating layer made of SiOx is laminated with a thickness of 5000 Å on a substrate with a cobalt wiring pattern (manufactured by International SEMATECH, a silicon substrate), and then patterned with a “SEMATECH 854” mask (L/S=9 μm/1 μm), and the thickness is applied thereon A test substrate in which a 100 Å barrier metal layer (barrier metal: TaN, Ti, TiN, Ru, or Mn) and a 7500 Å thick cobalt layer are sequentially stacked.

As shown in Tables 4 to 8, it was confirmed that the polishing liquid of Example 1B suppressed the occurrence of dishing and erosion with respect to the substrate having any barrier metal layer of Ta, TaN, Ti, TiN, Ru, and Mn. .

[Table 22]

[Table 23]

[Table 24]

[Table 25]

[Table 26]

[Example 83B]

Example 83B was prepared by the method similar to Example 1B except having carried out each component as shown in Table 9. In addition, Example 83B corresponds to the grinding|polishing liquid undiluted|stock solution.

In addition, the polishing liquid of Example 83B was diluted twice by using water as a diluent.

The pH change before and after dilution was 0.1, and it was confirmed that there was no difference in the performance of the polishing liquid before and after dilution.

[Table 27]

Claims (15)

Colloidal silica of association degrees 1-3,
organic acids,
an azole-based compound;
hydrogen peroxide and
a metal impurity containing a metal atom, and
A polishing liquid containing a compound represented by the following general formula (1), used for chemical mechanical polishing of a cobalt-containing layer, and having a pH of 6.5 to 8.0,
As the azole-based compound, a benzotriazole-based compound and an azole-based compound different from the benzotriazole-based compound are contained, and the benzotriazole-based compound is benzotriazole, 5-methylbenzotriazole, 5,6 - selected from the group consisting of dimethylbenzotriazole and 5-aminobenzotriazole,
As said organic acid, it contains an amino acid,
It is a polishing liquid, wherein when the polishing liquid and the cobalt substrate are brought into contact for 24 hours, a reaction layer with a thickness of 0.5 to 20 nm containing cobalt atoms is formed on the cobalt substrate,
The content of the organic acid is 0.8 to 4 mass % with respect to the total mass of the polishing liquid,
The content of colloidal silica in the association degrees 1 to 3 is 0.01 to 1 mass % with respect to the total mass of the polishing liquid,
The content of the hydrogen peroxide is 0.001 to 2.5 mass% with respect to the total mass of the polishing liquid,
The content of the azole compound is 0.01 to 1.3 mass % with respect to the total mass of the polishing liquid,
The compound represented by the general formula (1) is 0.00001 to 1000 mass ppb with respect to the total mass of the polishing liquid,
The metal impurity contains at least one specific metal atom selected from the group consisting of an Fe atom, a Cu atom, an Ag atom, and a Zn atom,
When the specific metal atom is one selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms, the content of the specific metal atoms is 0.01 to 100 mass ppb with respect to the total mass of the polishing liquid,
When the specific metal atom is at least two types selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms, the content of each specific metal atom is 0.01 to 100 mass ppb with respect to the total mass of the polishing liquid,
The ratio T1 of the content of the hydrogen peroxide calculated from the following formula (1) and the total content of a specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms contained in the metal impurities, 30000 to 500000,
When the polishing liquid is in contact with a barrier substrate made of any one metal selected from the group consisting of Ta, TaN, Ti, TiN, Ru, and Mn for 24 hours, the barrier substrate contains atoms of the metal A reaction layer with a thickness of 0.01 to 5 nm is formed,
Before and after providing the polishing liquid as a chemical mechanical polishing liquid, the ratio T2 of the average particle diameter before and after chemical mechanical polishing calculated from the following formula (2) of the colloidal silica of the association degrees 1 to 3 is 1 to 2.5 Phosphorus, abrasive.
General formula (1):
N(R ¹ )(R ² )(R ³ )
In General Formula (1), R ¹ to R ³ each independently represent a hydrogen atom or an alkyl group.
Formula (1): T1 = content of hydrogen peroxide / total content of specific metal atoms selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms contained in the metal impurities
Equation (2):
T2 = average particle diameter after chemical mechanical polishing/average particle diameter before chemical mechanical polishing The method according to claim 1,
The polishing liquid whose polishing rate ratio R1 computed from following formula (3) is 250-2500.
Equation (3):
R1 = polishing rate of the cobalt substrate by the polishing liquid / polishing rate of the barrier substrate by the polishing liquid The method according to claim 1 or 2,
The metal impurity contains metal particles containing at least one specific metal atom selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms;
When the specific metal atom contained in the metal particle is one selected from the group consisting of an Fe atom, a Cu atom, an Ag atom, and a Zn atom, the content of the specific metal atom contained in the metal particle is the total mass of the polishing liquid 0.01 to 50 mass ppb with respect to
When the specific metal atoms contained in the metal particles are at least two types selected from the group consisting of Fe atoms, Cu atoms, Ag atoms, and Zn atoms, the content of each specific metal atom contained in the metal particles is determined by polishing Polishing liquid which is 0.01-50 mass ppb with respect to the liquid total mass. The method according to claim 1,
The polishing liquid further comprising an organic solvent, wherein the content of the organic solvent is 0.01 to 20 mass% with respect to the total mass of the polishing liquid. The method according to claim 1,
N-cocoyl sarcosinate, N-lauroyl sarcosinate, N-stearoyl sarcosinate, N-oleoyl sarcosinate, N-myristoyl sarcosinate, N-lauroyl glycine, N-myristo Ilglycine, N-palmitoylglycine, N-lauroylglutamic acid, N-cocoylglutamic acid, N-cocoylglutamic acid potassium, N-lauroyl sarcosinate potassium, N-lauroylalaninate, N-myristo A polishing liquid further comprising at least one compound selected from the group consisting of ylalaninate and N-cocoylalaninate potassium, wherein the total content of the compound is 0.001 to 5 mass % with respect to the total mass of the polishing liquid. . A polishing liquid comprising a dilution step of obtaining the polishing liquid according to claim 1 by mixing water with the polishing liquid stock solution containing colloidal silica of association degrees 1 to 3, an organic acid, an azole compound, and hydrogen peroxide manufacturing method. It contains colloidal silica of association degrees 1 to 3, an organic acid, an azole compound, and hydrogen peroxide,
In order to prepare the polishing liquid according to claim 1, the polishing liquid stock solution used after diluting 2 to 50 times. 8. The method of claim 7,
When diluted 2 to 50 times with water, the pH change before and after dilution is 0.01 to less than 1, the polishing liquid stock solution. A polishing liquid undiluted solution container, comprising: the polishing liquid stock solution according to claim 7; and a container made of an iron-free metal material for accommodating the polishing liquid stock solution. While supplying the polishing liquid according to claim 1 to the polishing pad mounted on the polishing platen, the surface to be polished is brought into contact with the polishing pad, and the object to be polished and the polishing pad are relatively moved to remove the surface to be polished. A chemical mechanical polishing method comprising a step of polishing to obtain a polished object to be polished. 11. The method of claim 10,
A chemical mechanical polishing method, wherein the object to be polished contains a cobalt-containing layer made of at least one selected from the group consisting of cobalt and cobalt alloys. delete delete delete delete

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