KR20180135029A - Abrasive liquid, and chemical mechanical polishing method - Google Patents

Abstract

An object of the present invention is to provide a polishing liquid which is hard to aggregate abrasive grains contained in a polishing liquid and which is less likely to cause defects on a surface to be polished even when applied to CMP. It is another object of the present invention to provide a chemical mechanical polishing method. The polishing solution of the present invention is a polishing solution for chemical mechanical polishing comprising abrasive grains, an organic acid and an alcohol A, wherein the alcohol A is at least one member selected from the group consisting of methanol, ethanol, 1-propanol, and isopropanol, The content of alcohol A is 1.0 to 800 mass ppm in the total mass of the polishing liquid.

Description

Abrasive liquid, and chemical mechanical polishing method

The present invention relates to a polishing liquid, and a chemical mechanical polishing method.

BACKGROUND ART 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, .

As a polishing liquid to be used for CMP, for example, Patent Document 1 discloses a polishing liquid which comprises an alcohol, abrasive grains and water having a solubility in water of 0.5 to 8 wt% at a liquid temperature of 25 DEG C Polishing liquid. &Quot;

Japanese Patent Application Laid-Open No. 2004-074175

The inventor of the present invention has studied the polishing liquid described in Patent Document 1 and found that there is a problem that the abrasive contained in the polishing liquid tends to aggregate when the polishing liquid is stored. It has also been found that when the above polishing liquid is applied to CMP, there is a problem that defects are likely to occur on the polished surface of the object to be polished.

Therefore, it is an object of the present invention to provide a polishing liquid which is hard to cause defects (that is, " scratches ") on the polished surface to be polished even when CMP is applied thereto (in other words, And the like.

It is another object of the present invention to provide a chemical mechanical polishing method.

Means for Solving the Problem As a result of intensive studies to attain the above object, the present inventors have found that a polishing solution for chemical mechanical polishing comprising an abrasive grain, an organic acid, and a predetermined alcohol A and a polishing solution having an alcohol A content within a predetermined range, And the present invention has been accomplished.

That is, it has been found that the above problems can be achieved by the following constitution.

[1] A polishing solution for chemical mechanical polishing comprising abrasive grains, an organic acid and an alcohol A, wherein the alcohol A is at least one selected from the group consisting of methanol, ethanol, 1-propanol, and isopropanol, Is 1.0 to 800 mass ppm of the total mass of the polishing liquid.

[2] The polishing liquid according to [1], wherein the mass ratio of the alcohol A to the organic acid is 0.001 to 0.05.

[3] The polishing liquid according to [1] or [2], further comprising a charge control agent and containing at least one member selected from the group consisting of a charge control agent, an inorganic acid, an ammonium salt of an organic acid, and an ammonium salt of an inorganic acid.

[4] The polishing liquid according to [3], wherein the content of the charge control agent is 10 to 1000 mass ppm relative to the total mass of the polishing liquid.

[5] The polishing liquid according to [3] or [4], wherein the mass ratio of the alcohol A to the charge control agent is 0.1 to 50.

[6] The polishing liquid according to any one of [1] to [5], wherein the organic acid is an amino acid.

[7] The use of a compound according to [7], wherein the amino acid is selected from the group consisting of glycine, alanine, arginine, isoleucine, leucine, valine, phenylalanine, asparagine, glutamine, lysine, histidine, proline, tryptophan, , And N-methylglycine. [7] The polishing liquid according to [6], wherein the polishing liquid is at least one selected from the group consisting of N-methylglycine.

[8] The polishing liquid according to [6] or [7], which contains two or more kinds of amino acids.

[9] The polishing liquid according to any one of [1] to [8], wherein the pH of the polishing liquid is 5.0 to 8.0.

[10] The polishing liquid according to any one of [1] to [9], further containing an oxidizing agent.

[11] The polishing liquid according to [10], which contains two or more kinds of oxidizing agents.

[12] The polishing liquid according to any one of [1] to [11], which further contains two or more kinds of azole compounds.

[13] The polishing liquid according to [12], wherein the two or more azole compounds contain a benzotriazole compound and an azole compound different from the benzotriazole compound.

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

[15] The polishing liquid according to any one of [1] to [14], wherein the content of the organic acid is 1.0 to 20 mass% with respect to the total mass of the polishing liquid.

[16] The polishing liquid according to any one of [1] to [15], wherein the abrasive is colloidal silica.

[17] While supplying the polishing solution described in any one of [1] to [16] to the polishing pad mounted on the polishing table, the surface to be polished of the object to be polished is brought into contact with the polishing pad, And polishing the surface to be polished by relatively moving to obtain an object to be polished.

[18] The chemical mechanical polishing method according to [17], wherein the object to be polished contains at least one layer selected from the group consisting of copper, copper alloy, tungsten, tungsten alloy, silicon nitride, and polysilicon.

According to the present invention, it is possible to provide a polishing liquid which has an excellent long-term stability and which is less likely to cause defects on the surface to be polished (hereinafter also referred to as "the effect of the present invention") even when applied to CMP.

According to the present invention, a chemical mechanical polishing method can also be provided.

Hereinafter, the present invention will be described in detail based on embodiments.

Further, the description of the constituent elements described below is based on the embodiment of the present invention, and the present invention is not limited to such embodiment.

In the present specification, the numerical value range indicated by "~" means a range including numerical values written before and after "~" as a lower limit value and an upper limit value.

[Abrasive solution]

A polishing liquid according to an embodiment of the present invention is a polishing liquid for chemical mechanical polishing comprising an abrasive grain, an organic acid and an alcohol A, wherein the alcohol A is selected from the group consisting of methanol, ethanol, 1-propanol, and isopropanol And the content of alcohol A is 1.0 to 800 mass ppm in the total mass of the polishing liquid. Also, in this specification, ppm means parts per million.

[Alcohol A (Alc)]

One of the characteristic points of the abrasive liquid is that the content of the alcohol A is 1.0 to 800 mass ppm in the total mass of the abrasive liquid.

When the content of the alcohol A exceeds the upper limit, a full value of the zeta potential of the abrasive surface (particularly the surface of the colloidal silica) is lowered, and the abrasive grains tend to aggregate in the polishing liquid during storage.

On the other hand, if the content of the alcohol A is less than the lower limit, if the polishing liquid is applied to the CMP, defects are likely to be generated on the polished surface of the object to be polished.

The content of the alcohol A is 1.0 to 800 mass ppm, preferably 1.0 to 750 mass ppm, more preferably 10 to 500 mass ppm, based on the total mass of the polishing liquid.

The alcohol A is at least one selected from the group consisting of methanol, ethanol, 1-propanol, and isopropanol.

As the alcohol A, one type may be used alone, or two or more types may be used in combination. When two or more alcohols A are used in combination, the total content of two or more alcohols A is 1.0 to 800 mass ppm, and the preferable ranges thereof are as described above.

In the present specification, the content of alcohol A in the polishing liquid is intended to be a content measured by the following method.

Measurement of the alcohol A content in the polishing liquid is carried out by gas chromatography. The measurement conditions of the gas chromatography are as follows. Further, when the blending ratio of each component of the polishing liquid is clear, the alcohol A content can be obtained from the alcohol A blending ratio to the total mass of the polishing liquid to replace the above measurement.

Gas Chromatography: 7890 series manufactured by Agilent Technologies

Temperature rising condition: Initial temperature: 40 占 폚, temperature rising rate: 10 占 폚 /

- Capillary column: Agilent J & B GC column DB-WAX, 60 m x 0.25 mm (inner diameter), film thickness: 0.25 m

Carrier gas flow rate: Helium 1.0 mL / min

· Inlet temperature: 250 ° C

Hydrogen flame Ion detector Temperature: 300 ° C

(pH)

The pH of the polishing liquid is not particularly limited, but is preferably 1.0 to 14.0. Among them, 5.0 to 8.0 is more preferable.

When the pH is 5.0 or more, a polishing solution having better stability over time is obtained, and even when the polishing solution is applied to CMP, defects are less likely to occur on the surface to be polished. For example, the isoelectric point of the zeta potential on the surface of the colloidal silica is in the vicinity of pH 4.0. Therefore, by adjusting the pH of the polishing liquid to the above-mentioned range larger than the isoelectric point, It is difficult to coagulate the particles.

On the other hand, when the pH is 8.0 or less, dishing is less likely to occur on the surface to be polished of the object to be polished when the polishing liquid is applied to CMP.

[Grain (A)]

The polishing liquid contains abrasive grains. The abrasive is not particularly limited, and known abrasive grains can be used.

Examples of the abrasive grains include inorganic abrasives such as silica, alumina, zirconia, ceria, titania, germania and silicon carbide; Polystyrene, polystyrene, polyacrylic, and polyvinyl chloride. Among them, silica particles are preferable as the abrasive grains because of excellent dispersion stability in the abrasive liquid and small number of occurrence of polishing scratches (scratches) caused by CMP.

The silica particles are not particularly limited and include, for example, precipitated silica, fumed silica, and colloidal silica. Among them, colloidal silica is more preferable.

The average primary particle diameter of the abrasive grains is not particularly limited, but is preferably 1 to 100 nm in that the abrasive liquid has better dispersion stability. The average primary particle size can be confirmed by a catalog of the manufacturer.

Examples of commercially available abrasive grains include PL-1, PL-2, PL-3, PL-7 and PL-10H (all trade names, manufactured by FUSO KAGAKU KOGYO CO., LTD.) As colloidal silica.

The content of abrasive grains is not particularly limited and is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, more preferably 10% by mass or less, and most preferably 5% by mass or less based on the total mass of the polishing liquid. Within this range, a better polishing rate can be obtained when the polishing liquid is applied to CMP.

The abrasive grains may be used alone or in combination of two or more. When two or more kinds of abrasive grains are used together, the total content is preferably within the above range.

It is preferable that the content of abrasive grains satisfies the following relationship with the content of the above-mentioned alcohol A. That is, the mass ratio (content of alcohol A / content of abrasive grain: also referred to as "Alc / A" ratio) of the content of the alcohol A to the content of the abrasive grains is preferably 0.0001 to 1.5, more preferably 0.01 to 0.08, 0.1 to 0.7 is more preferable.

The Alc / A ratio is 0.1 to 0.7, and when the polishing liquid is applied to the CMP, a better polishing rate is obtained.

[Organic acid (B)]

The polishing liquid contains an organic acid. The organic acid is a compound different from the oxidizing agent and the charge control agent to be described later and has the function of promoting oxidation of the metal, adjusting the pH of the polishing liquid, and acting as a buffer.

As the organic acid, a water-soluble organic acid is preferable.

The organic acid is not particularly limited and a known organic acid can be used.

Examples of the organic acid include 1-hydroxyethylidene-1,1-diphosphonic acid (hereinafter also referred to as "HEDP"), diethylene triamine o acetic acid (hereinafter also referred to as "DTPA" But are not limited to, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, But are not limited to, hexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimetic acid, , Tartaric acid, citric acid, lactic acid, hydroxyethyliminoacetic acid, and iminoacetic acid.

As the organic acid, an amino acid is more preferable because it has better water solubility.

The amino acid is not particularly limited, and a known amino acid can be used.

Examples of amino acids include glycine, alanine (? -Alanine and / or? -Alanine), arginine, isoleucine, leucine, valine, phenylalanine, asparagine, glutamine, lysine, histidine, proline, tryptophan, , Glutamic acid, serine, threonine, tyrosine, cysteine, methionine, and N-methylglycine.

Of these, glycine,? -Alanine,? -Alanine, L-asparaginic acid or methylglycine (N-methylglycine) is preferable as the amino acid in view of the effect of the present invention, , And / or methylglycine are more preferable.

The amino acids may be used singly or in combination of two or more kinds. When two or more kinds of amino acids are used in combination, the total content is preferably within the above range.

Above all, it is preferable that the polishing liquid contains two or more kinds of amino acids in that a polishing liquid having a better effect of the present invention can be obtained.

Two or more kinds of amino acids are not particularly limited, and the above amino acids can be used in combination. Of these, glycine, alanine, alanine and N (N) are preferable as the two or more kinds of amino acids because a more excellent polishing rate can be obtained when the polishing liquid is applied to CMP and dishing is more difficult to occur on the polished surface of the object to be polished. -Methylglycine, a combination of glycine and N-methylglycine is preferable.

The content of the organic acid is not particularly limited and is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and most preferably 50% by mass or less based on the total mass of the polishing liquid , More preferably 25 mass% or less, further preferably 20 mass% or less, and particularly preferably 10 mass% or less.

When the content of the organic acid is 0.1 mass% or more, a better polishing rate can be obtained when the polishing liquid is applied to CMP. When the content of the organic acid is 50 mass% or less, dishing is less likely to occur on the surface to be polished when the polishing liquid is applied to CMP.

When the content of the organic acid is 1.0 to 20 mass% with respect to the total mass of the polishing liquid, a polishing liquid having a better effect of the present invention is obtained.

The organic acids may be used alone or in combination of two or more. When two or more kinds of organic acids are used in combination, the total content is preferably within the above range.

It is preferable that the content of the organic acid satisfies the following relationship with the content of the alcohol A described above. That is, the mass ratio (the alcohol A content / the organic acid content; also referred to as the "Alc / B" ratio) of the content of the alcohol A to the content of the organic acid is preferably from 0.0001 to 0.2, more preferably from 0.0006 to 0.1, More preferably 0.001 to 0.05.

When the Alc / B ratio is 0.001 to 0.05, a better polishing rate can be obtained when the polishing liquid is applied to CMP.

[Optional Components]

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

<Anti-Corrective Agent (C)>

The abrasive liquid may contain an anticorrosive agent.

It is preferable that the anticorrosive has an action of adsorbing on the polished surface of the object to be polished to form a film and controlling the corrosion of the metal. The anticorrosive agent is not particularly limited and a known anticorrosive agent can be used. Among them, an azole compound is preferable.

(Azole compound)

In the present specification, the azole compound is intended to mean a compound containing a heteroaromatic ring containing at least one nitrogen atom, and preferably 1 to 4 nitrogen atoms. The azole compound may contain an atom other than a nitrogen atom as a hetero atom.

In addition, the derivative is intended to include a compound having a substituent group that the heterocyclic ring may contain.

Examples of the azole compound include a pyrrole skeleton, an imidazole skeleton, a pyrazole skeleton, an isothiazol skeleton, an isoxazol skeleton, an isoxazole skeleton, a triazol skeleton, a tetrazole skeleton, an imidazole skeleton, a thiazole skeleton, Compounds having an isooxazole skeleton, a thiadiazole skeleton, an oxadiazole skeleton, and a tetrazole skeleton.

The azole compound may be an azole compound further containing a polycyclic structure containing a condensed ring in the above skeleton. Examples of the azole compound containing the polycyclic structure include an indole skeleton, a purine skeleton, an indazole skeleton, a benzimidazole skeleton, a carbazole skeleton, a benzoxazole skeleton, a benzothiazole skeleton, a benzothiadiazole skeleton, And compounds containing a naphtoimidazole skeleton.

The substituent which the azole compound may contain is not particularly limited and includes, for example, a halogen atom (fluorine atom, chlorine atom, bromine atom, or iodine atom), an alkyl group (straight chain, branched or cyclic alkyl group, An alkenyl group, an alkynyl group, an aryl group, a heterocyclic group (regardless of the substitution position), an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group , A heterocyclic oxycarbonyl group, a carbamoyl group (examples of the carbamoyl group having a substituent include an N-hydroxycarbamoyl group, an N-acylcarbamoyl group, a N-sulfonylcarbamoyl group, A carbamoyl group, a carboxyl group or a salt thereof, a oxalyl group, an oxoamino group, a cyano group, a carbonimidoyl group, a carbamoyl group, a carbamoyl group, A formyl group, a hydroxyl group, an alkoxy group ( An aryloxy group, a heterocyclic oxy group, an acyloxy group, a carbonyloxy group, a carbamoyloxy group, a sulfonyloxy group, an amino group, an acylamino group, a sulfonamido group , A cyano group, a cyano group, a cyano group, a hydrazino group, an ammonio group, an oxamoyl amino group, an N, N, - (alkyl or aryl) sulfonylureido group, an N-acylureido group, an N-acylsulfamoylamino group, a hydroxyamino group, a nitro group, a heterocyclic group containing a quaternized nitrogen atom (for example, pyridinium (Imidazolyl group, quinolinyl group, and isoquinolinio group), an isocyanato group, an imino group, a mercapto group, an (alkyl, aryl, or heterocyclic) (Alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, sulfo group or salt thereof, sulfamoyl group (examples of the sulfamoyl group having a substituent include N- An acylsulfamoyl group, and a N-sulfonylsulfamoyl group) or a salt thereof, a phosphino group, a phosphine group, a phosphineoxy group, a phosphinylamino group, and a silyl group.

Among them, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group (a straight chain, a branched or cyclic alkyl group, a polycyclic alkyl group such as a bicycloalkyl group, An alkenyl group, an alkynyl group, an alkynyl group, an aryl group, or a heterocyclic group (regardless of the substitution position).

Here, " active meta popular " means a meta popular replaced with two electronic precincts. The term "electron-attracting group" includes, 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, Group, or a carbonimidyl group. The two electron-attracting groups may be bonded to each other to have a cyclic structure. The term " salt " means a cation such as an alkali metal, an alkaline earth metal, and a heavy metal; Ammonium ions, and phosphonium ions.

Specific examples of the azole compound include 5-methylbenzotriazole, 5-aminobenzotriazole, benzotriazole, 5,6-dimethylbenzotriazole, 3-amino-1,2,4-triazole, 1 , 2,4-triazole, 3,5-dimethylpyrazole, pyrazole, and imidazole.

The content of the azole compound is preferably 0.001 to 1.6 mass% with respect to the total mass of the polishing liquid.

The azole compounds may be used alone or in combination of two or more. When two or more azole compounds are used in combination, the total content is preferably within the above range.

Among them, it is preferable to use two or more azole compounds in combination in order to obtain a polishing liquid having a better effect of the present invention. The mode of each of the two or more azole compounds is the same as that of the azole compound.

As the azole compounds of two or more kinds, a benzotriazole compound (a compound containing a benzotriazole skeleton) and a compound other than a benzotriazole compound (benzotriazole A skeleton-free compound).

The compound containing no benzotriazole skeleton is not particularly limited, but from the viewpoint of obtaining a polishing liquid having a more excellent effect of the present invention, a 1,2,4-triazole compound, a pyrazole compound, and an imidazole compound And at least one member selected from the group consisting of

The content of the anticorrosive (C) is preferably 0.001 to 1.6% by mass based on the total mass of the polishing liquid.

The anticorrosive agent (C) may be used alone or in combination of two or more. When two or more anticorrosive agents (C) are used in combination, the total content is preferably within the above range.

The content of the anticorrosive (C) preferably satisfies the following relationship with the content of the alcohol (A). That is, the mass ratio (content of alcohol A / amount of anticorrosive agent: also referred to as "Alc / C" ratio) of the content of the alcohol A to the content of the anticorrosive is preferably 0.004 or more, more preferably 0.0045 or more, More preferably 0.01 or more, particularly preferably 0.03 or more, most preferably 0.04 or more, more preferably 30 or less, still more preferably 25 or less, still more preferably 5 or less.

When the Alc / C ratio is 0.01 or more, a better polishing rate can be obtained when the polishing liquid is applied to CMP. When the Alc / C ratio is 0.04 or more, dishing is more unlikely to occur on the surface to be polished of the object to be polished when the polishing liquid is applied to CMP.

On the other hand, when the Alc / C ratio is 5 or less, dishing is more unlikely to occur on the surface to be polished of the object to be polished when the polishing liquid is supplied to the CMP.

&Lt; Oxidizing agent (D) >

The polishing liquid may contain an oxidizing agent. The oxidizing agent is not particularly limited, and a known oxidizing agent can be used.

Examples of the oxidizing agent include hydrogen peroxide, peroxide, nitric acid, nitrate, ionodate, perodinate, hypochlorite, chlorite, chlorate, perchlorate, persulfate, heavy chromate, (II) salts, and iron (III) salts, and hydrogen peroxide is more preferable. The oxidizing agent may be used alone, or two or more kinds of oxidizing agents may be used in combination.

Among them, in the case of applying to a CMP of a substrate (an object to be polished) containing at least one kind of layer selected from the group consisting of tungsten and tungsten alloy, an oxidizing agent having a better effect of the present invention is obtained It is preferable to use two or more of them in combination.

When two or more kinds of oxidizing agents are used in combination, it is preferable to use a combination of a first oxidizing agent having a higher redox potential and a second oxidizing agent (G) having a lower redox potential.

As the first oxidizing agent, for example, at least one kind selected from the group consisting of hydrogen peroxide and peroxide is preferable among the above oxidizing agents, and hydrogen peroxide is more preferable.

As the second oxidizing agent, for example, an iron (III) salt is preferable among the above oxidizing agents, and it is more preferable to use at least one selected from the group consisting of iron nitrate, iron phosphate, iron sulfate and potassium ferricyanide, iron (Fe (nO _{3) 3)} is more preferable.

The content of the oxidizing agent is not particularly limited, but it is preferably 0.1 to 9.0% by mass based on the total mass of the polishing liquid.

When the content of the oxidizing agent is 0.1 mass% or more, a better polishing rate can be obtained when the polishing liquid is applied to CMP.

When the content of the oxidizing agent is 9.0 mass% or less, dishing is less likely to occur on the surface to be polished when the polishing liquid is applied to CMP.

When two or more kinds of oxidizing agents are used in combination, the total content is preferably within the above range.

It is preferable that the content of the oxidizing agent satisfies the following relation between the content of the alcohol A and the content of the alcohol A. That is, the mass ratio of the content of the alcohol A to the content of the oxidizing agent (the content of the alcohol A / the content of the oxidizing agent; also referred to as "Alc / D" ratio) is preferably 0.000.5 or more, more preferably 0.005 or more , More preferably 0.04 or more, and is preferably 0.09 or less, more preferably 0.07 or less.

When the Alc / D ratio is 0.005 or more, a better polishing rate can be obtained when the polishing liquid is applied to CMP. When the Alc / D ratio is 0.04 or more, dishing is less likely to occur on the polished surface of the object to be polished when the polishing liquid is applied to CMP. When the Alc / D ratio is 0.07 or less, a better polishing rate can be obtained when the polishing liquid is applied to CMP.

When the first oxidizing agent and the second oxidizing agent are used together, the content of the second oxidizing agent preferably satisfies the following relationship with the content of the alcohol A: That is, the mass ratio of the content of the alcohol A to the content of the second oxidizing agent (the content of the alcohol A / the content of the second oxidizing agent; also referred to as "Alc / G" ratio) is preferably from 0.1 to 20.

&Lt; Charge control agent (E) >

The polishing liquid may contain a charge control agent. The charge control agent is not particularly limited, and known charge control agents can be used. The charge control agent has an action of adjusting the pH of the polishing liquid to the above range and / or adjusting the ionic strength of the polishing liquid to a desired range.

Examples of the charge control agent include an acid, an alkali, and a salt compound. Among them, it is preferable that the charge control agent contains at least one kind selected from the group consisting of an inorganic acid, an ammonium salt of an organic acid, and an ammonium salt of an inorganic acid from the viewpoint of obtaining a polishing liquid having a better effect of the present invention.

Examples of the inorganic acid include sulfuric acid, hydrochloric acid, and nitric acid.

Examples of the ammonium salt of the organic acid include ammonium benzoate and ammonium citrate.

Examples of the ammonium salt of an inorganic acid include ammonium sulfate, ammonium chloride, ammonium nitrate, and the like.

The content of the charge control agent is not particularly limited and is preferably 0.5 mass ppm or more, more preferably 1 mass ppm or more, more preferably 10 mass ppm or more, and 2 mass% or less, based on the total mass of the polishing liquid And more preferably not more than 1200 mass ppm.

When the content of the charge control agent is 10 ppm by mass or more, even when the polishing liquid is applied to CMP, defects are less likely to occur on the surface to be polished.

When the content of the charge control agent is 1000 ppm or less, the polishing liquid has more excellent stability over time, and when the polishing liquid is applied to CMP, a better polishing rate can be obtained. Further, It is difficult to occur.

The charge control agent may be used singly or in combination of two or more kinds. When two or more kinds of charge control agents are used in combination, the total content is preferably within the above range.

It is preferable that the content of the charge control agent satisfies the following relationship with the content of the alcohol A described above. That is, the mass ratio of the content of the alcohol A to the content of the charge control agent (the ratio of the content of the alcohol A to the content of the charge control agent; also referred to as the "Alc / E" ratio) is preferably 0.005 or more, Preferably 500 or less, more preferably 50 or less, and even more preferably 5 or less.

When the Alc / E ratio is 0.1 or more, a polishing liquid having a better aging stability can be obtained. Further, when the polishing liquid is applied to CMP, a better polishing rate can be obtained and dishing is more likely to occur on the polished surface of the object to be polished It is difficult to do.

Further, when the Alc / E ratio is 50 or less, even when the polishing liquid is applied to CMP, defects are less likely to occur on the polished surface.

When the Alc / E ratio is less than 5, the effect of the present invention is more excellent.

&Lt; Surfactant (F) >

The polishing liquid may contain a surfactant. The surfactant has a function of lowering the contact angle of the polishing liquid with respect to the surface to be polished, and the polishing liquid is easily wetted and diffused on the surface to be polished.

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

Examples of the anionic surfactant include sulfonates such as carboxylic acid salts and alkylbenzenesulfonic acids, sulfuric acid ester salts, and phosphoric acid ester salts.

Examples of the cationic surfactant include an aliphatic amine salt, an aliphatic quaternary ammonium salt, a benzalkonium chloride salt, a benzethonium chloride, a pyridinium salt, and an imidazolinium salt.

Examples of the amphoteric surfactant include carboxybetaine type, aminocarboxylic acid salt, imidazolinium betaine, lecithin, alkylamine oxide, and the like.

Examples of the nonionic surfactant include ether surfactants, ether ester surfactants, ester surfactants, liposomal surfactants, glycol surfactants, fluorochemical surfactants, and silicone surfactants.

The content of the surfactant is not particularly limited, but is preferably 0.00001 to 2.0 mass%, more preferably 0.0001 to 1.0 mass%, and even more preferably 0.001 to 0.1 mass% with respect to the total mass of the polishing liquid.

When the content of the surfactant is within the range of 0.0001 to 1.0% by mass, a polishing liquid having a better effect of the present invention can be obtained.

The surfactants may be used alone or in combination of two or more. When two or more surfactants are used in combination, the total content is preferably within the above range.

It is preferable that the content of the surfactant satisfies the following relationship between the content of the surfactant and the content of the alcohol A. That is, the mass ratio (content of alcohol A / content of surfactant: also referred to as "Alc / F" ratio) of the content of the alcohol A to the content of the surfactant is preferably 0.001 to 100, more preferably 0.002 to 80 More preferably from 0.005 to 50 parts by weight.

When the Alc / F ratio is within the above range, a polishing liquid having a better defect performance can be obtained.

<Hydrophilic polymer>

The abrasive liquid may contain a hydrophilic polymer (hereinafter also referred to as " water-soluble polymer ").

Examples of the hydrophilic polymer include polyglycols such as polyethylene glycol, alkyl ethers of polyglycols, polysaccharides such as polyvinyl alcohol A, polyvinyl pyrrolidone and alginic acid, And carboxylic acid-containing polymers such as polyacrylic acid, polyacrylamide, polymethacrylamide, and polyethyleneimine. Specific examples of such a hydrophilic polymer include water-soluble polymers described in Japanese Laid-Open Patent Publication Nos. 2009-088243, 0042- 0044, and Japanese Laid-Open Patent Publication No. 2007-194261.

The hydrophilic polymer is preferably a water-soluble polymer selected from polyacrylamide, polymethacrylamide, polyethyleneimine, and polyvinylpyrrolidone. Examples of the polyacrylamide or polymethacrylamide include those having a hydroxyalkyl group on the nitrogen atom (for example, N- (2-hydroxyethyl) acrylamide polymer or the like), or those having a substituent having a polyalkyleneoxy chain And the weight average molecular weight is more preferably from 2,000 to 50,000. As the polyethyleneimine, those having a polyalkyleneoxy chain on the nitrogen atom are preferable, and those having a repeating unit represented by the following general formula are more preferable.

[Chemical Formula 1]

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

The polyethyleneimine preferably has a HLB (Hydrophile-Lipophile Balance) value of 16 to 19.

The content of the hydrophilic polymer is not particularly limited, but is preferably 0.00001 to 2.0% by mass, more preferably 0.0001 to 1.0% by mass, more preferably 0.0001 to 1.0% by mass, more preferably 0.001 to 0.1% by mass based on the total mass of the polishing liquid % Is particularly preferable.

The hydrophilic polymer may be used alone or in combination of two or more. Further, a surfactant and a hydrophilic polymer may be used in combination. When two or more kinds of hydrophilic polymers are used in combination, the total content is preferably within the above range.

<Organic solvents>

The polishing liquid may contain an organic solvent. The organic solvent is not particularly limited, and a known organic solvent can be used. Among them, a water-soluble organic solvent is preferable.

Further, the organic solvent is a component different from the alcohol A described above.

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

More specifically, examples thereof include acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and acetonitrile.

Among them, methyl ethyl ketone, tetrahydrofuran, dioxane, N-methylpyrrolidone and the like are more preferable.

The content of the organic solvent is not particularly limited, but is preferably 0.001 to 5.0 mass%, more preferably 0.01 to 2.0 mass%, based on the total mass of the polishing liquid.

The organic solvent may be used alone or in combination of two or more. When two or more kinds of organic solvents are used in combination, the total content is preferably within the above range.

<Water>

It is preferable that the polishing liquid contains water. The water contained in the polishing liquid is not particularly limited, but ion-exchanged water or pure water can be used.

The content of water is not particularly limited, but is preferably 90 to 99% by mass, based on the total mass of the polishing liquid.

<Chelating agent>

The polishing liquid may contain a chelating agent (that is, a water softening agent) if necessary in order to reduce the adverse effects of mixed polyvalent metal ions and the like.

As the chelating agent, for example, a general-purpose water softening agent and / or a softening compound thereof, which are precipitation inhibitors of calcium and / or magnesium, may be used, and two or more kinds of these may be used in combination if necessary.

The content of the chelating agent may be an amount sufficient to block metal ions such as polyvalent metal ions to be incorporated, and is preferably 0.001 to 2.0 mass%, for example, in the total mass of the polishing liquid.

[Method of producing polishing solution]

The method for producing the polishing liquid is not particularly limited, and a known manufacturing method can be used. Examples of the method for producing the polishing liquid include a method of mixing the abrasive grains with the organic acid and the alcohol A. [ At this time, other components such as an azole compound, an oxidizing agent, a charge control agent, a surfactant, an organic solvent, water, and a chelating agent may be mixed.

When mixing the above components, the order of blending each component is not particularly limited. For example, a mixture prepared by preliminarily mixing the abrasive grains and the alcohol A may be prepared, and other components may be added to the mixture. A mixture prepared by preliminarily mixing the abrasive grains and water is prepared, and the mixture of alcohol A May be added.

There is no particular limitation on the method of making the alcohol A a predetermined amount with respect to the total mass of the polishing liquid. As the above-mentioned method, for example, a predetermined amount may be added to the total mass of the polishing liquid. When the raw material containing the respective components is also contained in advance in the alcohol A, if the mixing amount of the raw materials is adjusted so that the total amount of the alcohol A contained in the raw material becomes a predetermined amount with respect to the total mass of the polishing liquid, A polishing liquid can be produced.

Another embodiment of the method for producing a polishing liquid includes a method of preparing a polishing liquid by adding an oxidizing agent (for example, hydrogen peroxide) to a polishing liquid solution prepared by previously mixing components other than the oxidizing agent, before the preparation of the polishing liquid . According to this manufacturing method, since the polishing liquid is obtained by mixing the oxidizing agent with the polishing liquid stock solution containing a predetermined component, the content of the oxidizing agent with respect to the total mass of the polishing liquid can be easily controlled to a desired range. This is because the oxidizing agent decomposes with time and changes its content in the polishing liquid.

As another embodiment of the method for producing a polishing liquid, a concentrated liquid of a polishing liquid containing a predetermined component is prepared, and at least one selected from the group consisting of an oxidizing agent and water is added to the polishing liquid to prepare a polishing liquid having a predetermined characteristic And the like.

[Chemical mechanical polishing method]

A chemical mechanical polishing method according to an embodiment of the present invention is a method of polishing a surface of an object to be polished with a polishing pad by bringing the object to be polished into contact with the polishing pad while supplying the polishing liquid to a polishing pad attached to the polishing table, (Hereinafter also referred to as " CMP method ") which includes a step of relatively moving a workpiece to be polished to obtain an object to be polished (hereinafter also referred to as a "polishing step").

[Operation]

Examples of the object to be polished by the CMP method include at least one layer selected from the group consisting of copper, a copper alloy, tungsten, a tungsten alloy, silicon nitride, and polysilicon.

Examples of the above-mentioned object to be polished include a barrier metal film (barrier metal layer) formed on a surface of an interlayer insulating film (interlayer insulating layer) having concave portions and a copper or copper alloy formed to fill a concave portion on the surface of the barrier metal film And is a substrate having a conductor film (conductor layer). Such a substrate is typically a semiconductor substrate, preferably an LSI having a wiring made of a copper metal and / or a copper alloy, and it is particularly preferable that the wiring is a copper alloy.

Examples of the object to be polished include a wafer in which a conductive material film is formed on a substrate, a laminate in which a conductive material film is formed on an interlayer insulating film provided on a wiring formed on the substrate, and the like, .

Further, among the copper alloys, copper alloys containing silver are preferable. The amount of silver contained in the copper alloy is preferably 40 mass% or less, more preferably 10 mass% or less, further preferably 1 mass% or less, and preferably 0.00001 to 0.1 mass% The best effect is achieved.

<Substrate>

Examples of the substrate include those used in a wafer manufacturing process for an 8-inch or 12-inch semiconductor or a micromachine manufacturing process. As the type thereof, a sapphire substrate of a compound semiconductor used for a silicon wafer for semiconductor, an SOI (Silicon-On-Insulator) wafer, a semiconductor laser or the like is also included. Otherwise, after the wiring pattern is formed on the polymer film substrate, the pattern forming surface is also used for planarization.

The target wafer to be CMP-treated with the polishing liquid preferably has a diameter of 200 mm or more, particularly preferably 300 mm or more.

&Lt; Interlayer insulating film &

The interlayer insulating film preferably has a dielectric constant of 2.6 or less, and examples thereof include silicon nitride and polysilicon. Further, the thickness of the interlayer insulating film can be appropriately adjusted depending on the upper and lower portions of the wiring in the multilayer wiring, or between generations (nodes).

<Barrier metal film>

The barrier metal film is a film (layer) disposed between a conductor film (wiring) made of copper or a copper alloy provided on a semiconductor substrate and an interlayer insulating film to prevent diffusion of copper.

The material of the barrier metal film is preferably a low resistance metal material and specifically includes at least one selected from tantalum, tantalum compounds, titanium, titanium compounds, tungsten, tungsten compounds, and ruthenium And more preferably TiN, TiW, Ta, TaN, W, WN, or Ru. The thickness of the barrier metal film is preferably about 20 to 30 nm.

An object to be used in the CMP method according to the above embodiment can be produced, for example, by the following method.

First, an interlayer insulating film such as silicon nitride or polysilicon is laminated on a silicon substrate. Subsequently, recesses (substrate exposed portions) of a predetermined pattern are formed on the surface of the interlayer insulating film by a known means such as resist layer formation and etching to form an interlayer insulating film composed of convex portions and concave portions. On the interlayer insulating film, tungsten or a tungsten compound is deposited as a barrier layer covering the interlayer insulating film along the surface irregularities by vapor deposition or CVD (chemical vapor deposition). Further, a copper and / or a copper alloy is formed as a conductive material layer (hereinafter, referred to as a conductor layer) covering the barrier layer so as to fill the concave portion by vapor deposition, plating, CVD or the like to obtain an object having a laminated structure. The thicknesses of the interlayer insulating film, the barrier layer and the copper body layer are preferably 0.01 to 2.0 μm, 1 to 100 nm, and 0.01 to 2.5 μm, respectively.

[Polishing apparatus]

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

Examples of the CMP apparatus include a holder for holding an object to be polished (for example, a semiconductor substrate or the like) having a surface to be polished, and an abrasive platen to which a polishing pad is attached A general CMP apparatus may be used. As a commercially available product, for example, Reflexion (manufactured by Applied Materials) can be used.

<Polishing pressure>

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

&Lt; Number of revolutions of abrasive plate &

In the CMP method according to the above embodiment, the polishing is preferably carried out at a polishing rate of 50 to 200 rpm, more preferably at 60 to 150 rpm.

Further, in order to move the polishing body and the polishing pad relative to each other, the holder may be further rotated and / or rocked, the polishing platen may be rotated oily, or the belt-shaped polishing pad may be linearly moved in one direction of the longitudinal direction . Further, the holder may be in any state during fixation, rotation, or oscillation. These polishing methods can be appropriately selected depending on the surface to be polished and / or the polishing apparatus, provided that the polishing body and the polishing pad are relatively moved.

<Method of supplying polishing solution>

In the CMP method according to the above embodiment, while polishing the surface to be polished, the polishing liquid is continuously supplied to the polishing pad on the polishing platen by a pump or the like. The supply amount is not limited, but it is preferable that the surface of the polishing pad is always covered with the polishing liquid. The manner of the polishing liquid is the same as described above.

Example

Hereinafter, the present invention will be described in more detail based on examples. The materials, the amounts used, the ratios, the processing contents, the processing procedures, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed to be limited by the following embodiments. Also, "% " is intended to mean " mass% " unless specifically stated otherwise.

[Example 1]

The following components were mixed to prepare a chemical mechanical polishing solution.

0.1% by mass colloidal silica (average primary particle diameter: 35 nm, product name " PL3 ", manufactured by FUSO KAGAKU KOGYO CO., LTD.

Glycine (corresponding to organic acid and amino acid) 1.5% by mass

· 5-methylbenzotriazole (corresponds to an azole compound containing a benzotriazole skeleton) 0.001% by mass

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

Hydrogen peroxide (Corresponding to oxidizing agent) 1.0% by mass

Ammonium nitrate (corresponding to charge control agent) 1000 mass ppm

· Methanol (corresponding to alcohol A) 500 ppm

· Water (pure water) balance

[Examples 2 to 54, Comparative Examples 1 to 5]

The components shown in Tables 1, 2, 3 and 4 were mixed by the same method as in Example 1 to obtain respective polishing solutions. The symbols in Table 1 denote the following compounds and the like. The " content " in Table 1 indicates a value on a mass basis. The pH of each treatment solution was adjusted to the target pH by adding KOH / H ₂ SO ₄ .

PL3 (colloidal silica, product name " PL3 ", manufactured by FUSO KAGAKU KOGYO CO., LTD., Average primary particle diameter: 35 nm, corresponding to abrasive grain)

· Gly (Glycine, organic acid also corresponds to amino acid)

· Ala (alanine, organic acid also corresponds to amino acid)

· Asp (asparaginic acid, organic acid also corresponds to amino acids)

· NMG (N-methylglycine, organic acid also corresponds to amino acid)

· MaloA (malonic acid, corresponds to organic acid)

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

· BTA (benzotriazole, corresponds to an azole compound containing a benzotriazole skeleton)

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

· 5-ABTA (5-aminobenzotriazole, corresponds to an azole compound containing a benzotriazole skeleton)

3-AT (corresponding to 3-amino-1,2,4-triazole, azole compounds not containing a benzotriazole skeleton, and also azole compounds containing a 1,2,4-triazole skeleton)

Triaz (1,2,4-triazole, an azole compound not containing a benzotriazole skeleton, also an azole compound containing a 1,2,4-triazole skeleton)

3,5-DP (3,5-dimethylpyrazole, corresponds to an azole compound not containing a benzotriazole skeleton)

Pyraz (corresponding to an azole compound not containing a pyrazole, a benzotriazole skeleton, or a pyrazole compound containing a pyrazole skeleton)

Imidaz (corresponding to an imidazole, an azole compound not containing a benzotriazole skeleton, and an azole compound containing an imidazole skeleton)

· 5-ATZ (5-aminotetrazole, corresponds to an azole compound not containing a benzotriazole skeleton)

Am-Ni (corresponding to ammonium nitrate, charge control agent)

Am-Bz (ammonium benzoate, corresponding to charge control agent)

Am-Ci (triammonium citrate, corresponding to charge control agent)

RE-610 (product name: Rhodafac RE-610, manufactured by Rhodia, corresponding to a surfactant)

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

A43-NQ (trade name: Takesurf-A43-NQ, manufactured by Takemoto Yushi, anionic surfactant)

· S-465 (product name "Surfynol465", manufactured by Airproducts, nonionic surfactant)

· DBSH (corresponding to dodecylbenzenesulfonic acid, surfactant)

· MeOH (methanol, corresponds to alcohol A)

HEDP (1-hydroxyethylidene-1,1-diphosphonic acid, corresponding to organic acids)

· DTPA (corresponding to diethylene triamine o acetic acid, organic acid)

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

PEIEO: Polyethyleneimine having an ethyleneoxy chain having repeating units shown below, HLB value 18, n number: 20 (corresponding to a hydrophilic polymer)

(2)

[Evaluation of stability of polishing solution with time]

The change in the coagulated state of each of the prepared polishing solutions was measured using a Turbiscan (Teresa Scan MA2000, manufactured by Seishin Gijutsu Co., Ltd.). That is, the transmitted light intensity of the polishing liquid immediately after preparation and the transmitted light intensity of the polishing liquid after storage for 2 weeks in a thermostat at 40 占 폚 were measured, and the results were evaluated according to the following criteria. The results are shown in Tables 1 to 4. Further, C or more is preferable in practical use.

A: The change in transmitted light intensity before and after storage is 1% or less.

B: The change in transmitted light intensity before and after storage is more than 1% and less than 3%.

C: The change in transmitted light intensity before and after storage is more than 3% and not more than 5%.

D: The change in transmitted light intensity before and after storage is more than 5%.

[Evaluation of defect (scratch) performance]

The Cu wafer of BLANKET was polished by using each polishing liquid, the polished Cu wafer was cleaned, and then dried. The dried Cu wafer was observed using an optical microscope, and the state of the polished surface of the Cu wafer was evaluated based on the following evaluation criteria. The results are shown in Tables 1 to 4. Further, C or more is preferable in practical use.

A: The total number of defects (number of defects / Cu wafer) is 3 or less

B: Total number of defects is 4 or more, 5 or less

C: total number of defects is 6 or more, 10 or less

D: total number of defects is more than 11, less than 20

E: total number of defects is more than 21

[Measurement of zeta potential]

The surface potential (zeta potential) of each abrasive in each of the prepared polishing solutions was measured using a zeta potential meter (ELSZ-2000ZS, made by Otsuka Denki). The results are shown in Tables 1 to 4.

[Evaluation of polishing rate and dishing]

Polishing was carried out while supplying the polishing liquid to the polishing pad under the following conditions to evaluate the polishing rate and the dishing.

· Polishing apparatus: Reflexion (manufactured by Applied Materials)

· Wafer (Wafer):

(1) for calculating the polishing rate;

Copper: A blanket wafer having a diameter of 300 mm in which a Cu film having a thickness of 1.5 mu m was formed on a silicon substrate

Tungsten: A blanket wafer having a diameter of 300 mm, on which a W film having a thickness of 0.2 m was formed on a silicon substrate

Silicon nitride: A blanket wafer having a diameter of 300 mm, in which a silicon nitride film having a thickness of 1.5 mu m was formed on a silicon substrate

Polysilicon: A blanket wafer having a diameter of 300 mm in which a polysilicon film of 1.5 탆 in thickness was formed on a silicon substrate

(2) for evaluation of dishing;

Copper: copper wiring wafer (pattern wafer) having a diameter of 300 mm (mask pattern 754CMP (ATDF))

Tungsten: Tungsten wiring wafer (pattern wafer) having a diameter of 300 mm (mask pattern 754CMP (ATDF))

Silicon nitride: silicon nitride wiring wafers (pattern wafers) having a diameter of 300 mm (mask pattern 754CMP (ATDF))

Polysilicon: Polysilicon wiring wafers (pattern wafers) having a diameter of 300 mm (mask pattern 754CMP (ATDF))

Polishing pad: IC1010 (manufactured by Rodel)

Polishing conditions;

Polishing pressure (contact pressure between the polished surface and the polishing pad): 1.5 psi (Also, herein, psi is intended to mean pound-force per square inch per square pound and 1 psi = 6894.76 Pa)

Feed rate of polishing solution: 200 ml / min

Polishing Platen Speed: 110 rpm

Number of revolutions of polishing head: 100 rpm

(Assessment Methods)

Calculation of polishing rate: The blanket wafer of (1) was polished for 60 seconds, and the metal film thickness before and after polishing was calculated from the electrical resistance value for 49 places at equal intervals on the wafer surface. The average value of the obtained values was taken as the polishing rate and evaluated according to the following criteria. The results are shown in Tables 1-4. The polishing rate is preferably C or higher for practical use.

Copper (Cu) polishing rate:

A: The polishing rate is 400 nm / min or more.

B: The polishing rate is 300 nm / min or more and less than 400 nm / min.

C: The polishing rate is 200 nm / min or more and less than 300 nm / min.

D: The polishing rate is less than 200 nm / min.

· Tungsten (W) polishing rate:

A: The polishing rate is 250 nm / min or more.

B: The polishing rate is 150 nm / min or more and less than 250 nm / min.

C: The polishing rate is 50 nm / min or more and less than 150 nm / min.

D: The polishing rate is less than 50 nm / min.

Silicon nitride (SiN) Polishing rate:

A: The polishing rate is 30 nm / min or more.

B: The polishing rate is 20 nm / min or more and less than 30 nm / min.

C: The polishing rate is 10 nm / min or more and less than 20 nm / min.

D: The polishing rate is less than 10 nm / min.

Polysilicon (Poly-Si) Polishing rate:

A: The polishing rate is 100 nm / min or more.

B: The polishing rate is 70 nm / min or more and less than 100 nm / min.

C: The polishing rate is 40 nm / min or more and less than 70 nm / min.

D: The polishing rate is less than 40 nm / min.

Evaluation of dishing: The patterned wafer of (2) was further polished by an additional 25% of the time until the copper of the non-overlapping portion was completely polished, and the line and space portion (line 10 m , Space: 10 mu m) was measured with a contact type step scale Dektak V320Si (manufactured by Veeco) and evaluated according to the following criteria. The results are shown in Tables 1-4. Further, in practice, the evaluation G or more is preferable.

A: Dishing is 15nm or less.

B: Dishing is more than 15 nm and less than 20 nm.

C: Dishing is more than 20 nm and less than 25 nm.

D: Dishing is more than 25 nm and less than 30 nm.

E: Dishing is more than 30 nm and less than 35 nm.

F: Dishing is more than 35 nm and less than 40 nm.

G: Dishing is more than 40 nm and less than 45 nm.

H: Dishing is greater than 45 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]

In Table 1, the composition and the like of the polishing liquids according to Examples and Comparative Examples are listed for each row in Table 1 (1) [1] to [3]. For example, the polishing liquid of Example 1 contains 0.1 mass% of PL3 as the abrasive (the same with respect to the total mass of the abrasive liquid, hereinafter the same), 1.5 mass% of Gly as the organic acid, and 5-MBTA And 3-AT in an amount of 0.001 mass% and 0.2 mass%, respectively, containing 1.0 mass% of H ₂ O ₂ as an oxidizing agent, 1000 mass ppm of Am-Ni as a charge process material, and 500 mass of MeOH as an alcohol A ppm, and the remainder is water. the pH was 7, and the content ratio of the content of the alcohol A to each component was 0.50, 0.033 for the organic acid, 0.25 for the anticorrosive agent (total), 0.050 for the oxidizing agent and 0.50 for the charge control agent, B "for evaluating, 17 nm for evaluation," B "for evaluation, and" A "for evaluation, the zeta potential was -45 mV, the aging stability was" A "and the Cu polishing rate was 375 nm / min.

The above is also the same for Table 2 and Tables 2 to 4 (Table 1).

[Example 55]

A polishing solution according to Example 55 was prepared in the same manner as in Example 1 except that ethanol was used in place of methanol, and the same evaluation as that described above was performed.

[Example 56]

The polishing solution of Example 56 was prepared in the same manner as in Example 1 except that 1-propanol was used in place of methanol, and the same evaluation as that described above was performed.

[Example 57]

A polishing solution according to Example 57 was prepared in the same manner as in Example 1 except that isopropanol was used in place of methanol, and the same evaluation as that described above was performed.

[Example 58]

A polishing liquid according to Example 58 was obtained in the same manner as in Example 1, except that the abrasive grains were changed from PL3 to PL2 (colloidal silica, product name "PL2" manufactured by FUSO KAGAKU KOGYO CO., LTD., Average primary particle diameter: 25 nm) And the same evaluation as described above was carried out. As a result, the same evaluation results as those of Example 1 were obtained.

From the results shown in Table 1, it can be seen that the polishing liquid for chemical mechanical polishing comprising abrasive grains, an organic acid and an alcohol A is at least one selected from the group consisting of methanol, ethanol, 1-propanol, and isopropanol, The polishing liquids of Examples 1 to 41 having a content of alcohol A of 1.0 to 800 mass ppm in the total mass of the polishing liquid had a desired effect.

On the other hand, the polishing liquids of Comparative Examples 1 to 4 did not have a desired effect.

The polishing liquids of Examples 1, 3 and 4, in which the content ratio of alcohol A to organic acid was in the range of 0.001 to 0.05, had better stability with time as compared with the polishing liquid of Example 2, , The occurrence of defects was further suppressed. Further, it had a better polishing rate and a better dishing performance.

The polishing liquid had a better polishing rate and a better dishing performance than the polishing liquid of Example 5.

In addition, the polishing liquids of Examples 1, 39 and 40, in which the content of the charge control agent was 10 to 1000 mass ppm, were more inhibited from occurrence of defects when applied to CMP as compared with the polishing liquid of Example 38 . On the other hand, the abrasive liquid had a better aging stability as compared with the abrasive liquid of Example 37, and the generation of defects was further suppressed when applied to CMP.

The polishing liquids of Examples 3, 4, 1, 5, 40, and 39, in which the content of alcohol A in the charge control agent is in the range of 0.1 to 50, , And when it was applied to CMP, the generation of defects was further suppressed. In addition, it had a better polishing rate. On the other hand, the abrasive liquid had a better aging stability as compared with the abrasive liquid of Example 38, and the generation of defects was further suppressed when the abrasive liquid was applied to CMP.

The polishing liquids of Examples 11, 1, and 12 having a pH of 5.0 to 8.0, as compared with the polishing liquid of Example 10, had better stability over time and had a defect generation . On the other hand, the polishing liquid had a better dishing performance than the polishing liquid of Example 13.

In addition, the polishing liquids of Examples 1 and 15, in which the content of the organic acid was 1.0 to 20 mass%, had a better polishing rate as compared with the polishing liquid of Example 14. On the other hand, the polishing liquid had a superior dishing performance as compared with the polishing liquid of Example 16.

Claims (18)

An abrasive for chemical mechanical polishing comprising abrasive grains, an organic acid, and an alcohol (A)
Wherein the alcohol A is at least one member selected from the group consisting of methanol, ethanol, 1-propanol, and isopropanol,
Wherein the content of the alcohol A is 1.0 to 800 mass ppm in the total mass of the polishing liquid. The method according to claim 1,
Wherein the mass ratio of the alcohol A to the organic acid is 0.001 to 0.05. The method according to claim 1 or 2,
And further contains a charge control agent, and the charge control agent contains at least one selected from the group consisting of an inorganic acid, an ammonium salt of an organic acid, and an ammonium salt of an inorganic acid. The method of claim 3,
Wherein the content of the charge control agent is 10 to 1000 mass ppm relative to the total mass of the polishing liquid. The method according to claim 3 or 4,
Wherein the mass ratio of the alcohol A to the charge control agent is 0.1 to 50, The method according to any one of claims 1 to 5,
Wherein the organic acid is an amino acid. The method of claim 6,
Wherein the amino acid is selected from the group consisting of glycine, alanine, arginine, isoleucine, leucine, valine, phenylalanine, asparagine, glutamine, lysine, histidine, proline, tryptophan, asparaginic acid, glutamic acid, serine, threonine, tyrosine, cysteine, Methylglycine, and N-methylglycine. The method according to claim 6 or 7,
A polishing liquid containing at least two kinds of amino acids. The method according to any one of claims 1 to 8,
Wherein the polishing liquid has a pH of 5.0 to 8.0. The method according to any one of claims 1 to 9,
Further comprising an oxidizing agent. The method of claim 10,
A polishing liquid containing two or more kinds of the above oxidizing agents. The method according to any one of claims 1 to 11,
And further contains at least two azole compounds. The method of claim 12,
As the two or more azole compounds, a benzotriazole compound and an azole compound different from the benzotriazole compound are contained. 14. The method of claim 13,
Wherein the azole compound different from the benzotriazole compound is at least one selected from the group consisting of a 1,2,4-triazole compound, a pyrazole compound, and an imidazole compound. The method according to any one of claims 1 to 14,
Wherein the content of the organic acid is 1.0 to 20% by mass with respect to the total mass of the polishing liquid. The method according to any one of claims 1 to 15,
Wherein the abrasive grains are colloidal silica. A polishing pad according to any one of claims 1 to 16, wherein the polishing surface of the object to be polished is brought into contact with the polishing pad, and the object to be polished and the polishing pad are relatively And polishing the surface to be polished to obtain an object to be polished. 18. The method of claim 17,
Wherein the object to be polished contains at least one layer selected from the group consisting of copper, copper alloy, tungsten, tungsten alloy, silicon nitride, and polysilicon.