WO2019151144A1

WO2019151144A1 - Chemical mechanical polishing composition and polishing method

Info

Publication number: WO2019151144A1
Application number: PCT/JP2019/002526
Authority: WO
Inventors: 山田　裕也; 昌宏野田; 達也山中; 昂輝石牧
Original assignee: Jsr株式会社
Priority date: 2018-02-05
Filing date: 2019-01-25
Publication date: 2019-08-08
Also published as: TW201943828A; TWI788517B; TWI795521B; TW201942317A; TW201943829A

Abstract

Provided are: a chemical mechanical polishing composition which can polish a semiconductor substrate (particularly, a ruthenium film-containing substrate) at high speed and reduce polishing scratches on a surface to be polished while suppressing the generation of ruthenium tetraoxide which is highly toxic to the human body; and a polishing method by using said composition. This chemical mechanical polishing composition contains titanium oxide-containing particles (A) and an organic acid (B), wherein the titanium oxide-containing particles (A) have a full width at half maximum of a peak portion, at which the diffraction intensity in a powder X-ray diffraction pattern is maximum, of less than 1°.

Description

Chemical mechanical polishing composition and polishing method

The present invention relates to a chemical mechanical polishing composition and a polishing method using the same.

With the improvement of semiconductor integrated circuit manufacturing technology, high integration and high speed operation of semiconductor elements are required. As a result, the flatness of the semiconductor substrate surface required in the manufacturing process of fine circuits in semiconductor elements has become more severe, and chemical mechanical polishing (CMP) is a technology indispensable for the manufacturing process of semiconductor elements. It has become.

In CMP, while supplying a polishing composition containing abrasive grains and reagents onto a polishing pad, the semiconductor substrate is pressed against the polishing pad affixed on the surface plate, and the semiconductor substrate and the polishing pad are slid against each other. This is a technique for chemically and mechanically polishing a semiconductor substrate. In CMP, unevenness on the surface of a semiconductor substrate can be removed by chemical reaction with a reagent and mechanical polishing with abrasive grains, and the surface can be flattened.

In the semiconductor market where miniaturization is progressing, a semiconductor substrate with a tip node having a circuit line width of 10 nm is becoming mainstream. In order to realize fine wiring with a circuit line width on the order of 10 nm or more, a technique for improving the embedding property of the copper film by applying a ruthenium film having a low resistance and good compatibility with copper to the base of the copper film has been studied. ing.

Under such a background, a ruthenium film polishing composition (slurry) for planarizing a ruthenium film, which is a next-generation semiconductor material, by CMP has been studied (see, for example, Patent Documents 1 and 2). As such a ruthenium film polishing composition, in order to improve the ruthenium film polishing rate, a slurry in which abrasive grains such as alumina and titanium oxide and an oxidizing agent are used in combination has been studied.

Special table 2009-514219 Special table 2010-535424

However, in order to improve the polishing rate of the ruthenium film in CMP, it is necessary to use a ruthenium film polishing composition containing an oxidizing agent with high oxidizing power and / or abrasive grains with high hardness. However, in CMP using a ruthenium film polishing composition containing an oxidizing agent having high oxidizing power, there is a problem that ruthenium tetroxide having strong toxicity to the human body is likely to be generated, which hinders the production process. In addition, CMP using a ruthenium film polishing composition containing high-hardness abrasive grains has a problem that polishing scratches are likely to occur on the polished surface after polishing.

In addition, when titanium oxide particles are used as abrasive grains, the surface is chemically active, so it is easy to react with water, oxygen, nitrogen, etc. There was a problem of being easily damaged.

Therefore, some embodiments according to the present invention can suppress the generation of ruthenium tetroxide, which is highly toxic to the human body, can polish a semiconductor substrate (particularly a ruthenium film-containing substrate) at high speed, and can polish polishing scratches on the surface to be polished. An object of the present invention is to provide a chemical mechanical polishing composition capable of reducing the amount of polishing and a polishing method using the same. Another object of the present invention is to provide a chemical mechanical polishing composition having excellent stability in which generation of foaming is further reduced, in addition to the above object.

The present invention has been made to solve at least a part of the above-described problems, and can be realized as the following aspects or application examples.

[Application Example 1]
One aspect of the chemical mechanical polishing composition according to the present invention is:
(A) titanium oxide-containing particles;
(B) an organic acid;
Containing
The (A) titanium oxide-containing particles have a half width of less than 1 ° at the peak portion where the diffraction intensity in the powder X-ray diffraction pattern is maximum.

[Application Example 2]
In the chemical mechanical polishing composition of the above application example,
The (A) titanium oxide-containing particles further contain aluminum,
Wherein in (A) containing titanium oxide particles, it is possible the number of moles of titanium _{M Ti,} the number of moles of aluminum is taken as _{M _Al,} the value of M Ti _{/ M Al} is 6-70.

[Application Example 3]
In the chemical mechanical polishing composition of the above application example,
The ratio (Rmax / Rmin) between the major axis (Rmax) and the minor axis (Rmin) of the (A) titanium oxide-containing particles may be 1.1 to 4.0.

[Application Example 4]
In the chemical mechanical polishing composition of the above application example,
Furthermore, 0.001 mass% or more and 5 mass% or less of (C) oxidizing agents can be contained with respect to the total mass of the chemical mechanical polishing composition.

[Application Example 5]
In the chemical mechanical polishing composition of the above application example,
The (C) oxidizing agent may be at least one selected from potassium periodate, potassium hypochlorite, and hydrogen peroxide.

[Application Example 6]
In the chemical mechanical polishing composition of the above application example,
The content of the (A) titanium oxide-containing particles can be 0.1% by mass or more and 10% by mass or less with respect to the total mass of the chemical mechanical polishing composition.

[Application Example 7]
In the chemical mechanical polishing composition of the above application example,
The pH can be 7 or more and 13 or less.

[Application Example 8]
The chemical mechanical polishing composition of the above application example is
It can be used to polish a semiconductor substrate containing a ruthenium film.

[Application Example 9]
One aspect of the polishing method according to the present invention is:
A step of polishing a semiconductor substrate using the chemical mechanical polishing composition of the above application example.

[Application Example 10]
In the polishing method of the above application example,
The semiconductor substrate may include a ruthenium film.

According to one aspect of the chemical mechanical polishing composition of the present invention, the generation of ruthenium tetroxide, which is highly toxic to the human body, can be suppressed, and a semiconductor substrate, particularly a ruthenium film-containing substrate can be polished at high speed, and the object to be polished Surface scratches can be reduced. Moreover, according to one aspect of the chemical mechanical polishing composition according to the present invention, in addition to the above effects, it is possible to achieve excellent stability in which generation of foaming is further reduced. Further, according to one aspect of the polishing method of the present invention, by using the chemical mechanical polishing composition, a semiconductor substrate, particularly a ruthenium film-containing substrate can be polished at a high speed, and can be polished flat and with high throughput. .

FIG. 1 is a conceptual diagram schematically showing the major axis (Rmax) and minor axis (Rmin) of (A) titanium oxide-containing particles. FIG. 2 is a cross-sectional view schematically showing an object to be processed suitable for use in the polishing method according to this embodiment. FIG. 3 is a cross-sectional view schematically showing the object to be processed at the end of the first polishing process. FIG. 4 is a cross-sectional view schematically showing the object to be processed at the end of the second polishing process. FIG. 5 is a perspective view schematically showing a chemical mechanical polishing apparatus.

Hereinafter, preferred embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, Various modifications implemented in the range which does not change the summary of this invention are also included.

In this specification, a numerical range described using “to” means that numerical values described before and after “to” are included as a lower limit value and an upper limit value.

1. Chemical mechanical polishing composition The chemical mechanical polishing composition according to this embodiment contains (A) titanium oxide-containing particles and (B) an organic acid, and the (A) titanium oxide-containing particles are powder X. The full width at half maximum of the peak portion where the diffraction intensity in the line diffraction pattern is maximum is less than 1 °. Hereinafter, each component contained in the chemical mechanical polishing composition according to this embodiment will be described in detail.

1.1. (A) Titanium oxide-containing particles The chemical mechanical polishing composition according to this embodiment includes (A) titanium oxide-containing particles. “(A) Titanium oxide-containing particles” in the present invention may be particles formed only from titanium oxide, or may be particles containing other compounds than titanium oxide. (A) As for the titanium oxide contained in the titanium oxide-containing particles, any of rutile type, anatase type, amorphous, and a mixture thereof can be used.

(A) In the titanium oxide-containing particles, the upper limit of the full width at half maximum of the peak portion where the diffraction intensity in the powder X-ray diffraction pattern is maximum is less than 1 °, and preferably less than 0.7 °. The lower limit value of the half width is preferably 0.2 ° or more. When the full width at half maximum of the peak portion where the diffraction intensity is maximum is in the above range, the crystallites of the (A) titanium oxide-containing particles are uniform, and the hardness is optimum for polishing. As a result, the ruthenium film-containing substrate can be polished at high speed, and polishing scratches on the surface to be polished can be reduced.

The powder X-ray diffraction pattern is a diffraction measured at each incident angle in a two-dimensional graph with the incident angle as the horizontal axis and the diffraction intensity as the vertical axis when performing sample measurement by powder X-ray diffraction. Refers to the intensity plot line.

The (A) titanium oxide-containing particles in this embodiment have a ratio (Rmax / Rmin) of the major axis to the minor axis of 1.1 when the major axis of the (A) titanium oxide-containing particle is Rmax and the minor axis is Rmin. Is preferably 4.0 to 4.0, more preferably 1.5 to 3.8, and particularly preferably 2.0 to 3.5. If the ratio of the major axis to the minor axis (Rmax / Rmin) is 1.1 or more, the ruthenium film-containing substrate can be polished at high speed, and if the ratio of the major axis to the minor axis (Rmax / Rmin) is 4.0 or less. (A) Since the catch at the end of the titanium oxide-containing particles can be suppressed, polishing scratches on the polished surface of the ruthenium film-containing substrate can be reduced.

(A) The ratio of the major axis to the minor axis (Rmax / Rmin) of the titanium oxide-containing particles can be adjusted by appropriately controlling the heat treatment conditions, acid addition conditions, pulverization conditions, and the like in production.

(A) The major axis (Rmax) and minor axis (Rmin) of the titanium oxide-containing particles can be measured as follows. For example, when the image of one independent titanium oxide-containing particle 1 photographed by a transmission electron microscope is elliptical as shown in FIG. 1, the major axis a of the elliptical shape is defined as the major axis (Rmax of the titanium oxide-containing particle 1). ) And the short axis b of the elliptical shape is determined as the short diameter (Rmin) of the titanium oxide-containing particle 1. By such a discriminating method, for example, the major axis (Rmax) and minor axis (Rmin) of 50 titanium oxide-containing particles are measured, and after calculating the average value of major axis (Rmax) and minor axis (Rmin), the major axis and The ratio to the minor axis (Rmax / Rmin) can be calculated and obtained.

(A) When the titanium oxide-containing particles contain a compound other than titanium oxide, examples of the compound other than titanium oxide include aluminum hydroxide, aluminum oxide (alumina), aluminum chloride, aluminum nitride, aluminum acetate, and aluminum phosphate. And aluminum compounds such as aluminum sulfate, sodium aluminate, and potassium aluminate. In this specification, the (A) titanium oxide-containing particles containing an aluminum compound are also referred to as “aluminum / titanium oxide-containing particles”.

(A) In the case where the titanium oxide-containing particles are aluminum / titanium oxide-containing particles, when the number of moles of titanium in the aluminum / titanium oxide-containing particles is M _Ti and the number of moles of aluminum is M _Al , M _Ti / M The value of _Al is preferably 6 to 70, more preferably 10 to 65, and particularly preferably 20 to 60. If the value of M _Ti / M _Al is 6 or more, sufficient hardness for polishing can be obtained, so that the ruthenium film-containing substrate can be polished at high speed, and the titanium oxide-containing particles are chemically inert. As a result, the generation of foaming can be suppressed. When the value of M _Ti / M _Al is 70 or less, aggregation of the aluminum / titanium oxide-containing particles can be suppressed, so that polishing scratches on the surface to be polished can be reduced.

The value of M _Ti / M _Al is obtained by dissolving aluminum / titanium oxide-containing particles with dilute hydrofluoric acid and using ICP-MS (inductively coupled plasma mass spectrometer: manufactured by PerkinElmer, model number “ELAN DRC PLUS”). The content of titanium and aluminum in the aluminum / titanium oxide-containing particles can be measured and calculated from the measured values.

The aluminum / titanium oxide-containing particles are easily dispersed in a chemical mechanical polishing composition having a pH of 7 or more and 13 or less, and are excellent in stability. The reason is that, in the chemical mechanical polishing composition having a pH of 7 or more and 13 or less, the zeta potential of the aluminum / titanium oxide-containing particles is increased, and therefore, the dispersibility is considered to be improved by electrostatic repulsion between the particles. .

From such a viewpoint, the absolute value of the zeta potential of the aluminum / titanium oxide-containing particles in the chemical mechanical polishing composition having a pH of 7 or more and 13 or less is preferably 25 mV or more, more preferably 30 mV or more, and particularly preferably. Is 35 mV or more. If the absolute value of the zeta potential of the aluminum / titanium oxide-containing particles in the chemical mechanical polishing composition in the pH range is 25 mV or more, the dispersibility of the aluminum / titanium oxide-containing particles is improved, and the semiconductor substrate High-speed polishing can be performed while reducing polishing scratches (particularly a ruthenium film-containing substrate).

(A) The average particle diameter of the titanium oxide-containing particles is preferably 10 nm or more and 300 nm or less, more preferably 20 nm or more and 200 nm or less, and particularly preferably 25 nm or more and 150 nm or less. If the (A) titanium oxide-containing particles having an average particle size in the above range, a sufficient polishing rate can be obtained, and a chemical mechanical polishing composition excellent in stability without causing sedimentation / separation of particles can be obtained. As a result, good performance can be achieved. The average particle diameter of the (A) titanium oxide-containing particles is determined by measuring the specific surface area by the BET method using, for example, a flow-type specific surface area automatic measuring device (manufactured by Shimadzu Corporation, “micrometricsFlowSorbII2300”). It can be calculated.

(A) The content of the titanium oxide-containing particles is preferably 0.1% by mass or more, and 0.3% by mass or more with respect to the total mass of the chemical mechanical polishing composition from the viewpoint of polishing the semiconductor substrate at high speed. Is more preferable, and 0.5% by mass or more is particularly preferable. (A) The content of the titanium oxide-containing particles is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less from the viewpoint of reducing the occurrence of polishing scratches on the polished surface.

1.2. (B) Organic acid The chemical mechanical polishing composition according to this embodiment contains (B) an organic acid. (B) By containing the organic acid, the ruthenium film-containing substrate can be polished at a higher speed.

(B) As the organic acid, an ion composed of an element of a semiconductor material containing a metal such as ruthenium or an organic acid having a coordination ability with respect to the surface of the semiconductor material or the like is preferable. As such an organic acid, an organic acid having at least one of a hydroxyl group and a carboxyl group is preferable. With such an organic acid, the coordination ability with respect to the surface of a semiconductor material containing a metal such as ruthenium is increased, and the polishing rate can be improved.

Specific examples of (B) organic acids include stearic acid, lauric acid, oleic acid, myristic acid, dodecylbenzenesulfonic acid, alkenyl succinic acid, lactic acid, tartaric acid, fumaric acid, glycolic acid, phthalic acid, maleic acid, formic acid, Acetic acid, oxalic acid, citric acid, malic acid, malonic acid, glutaric acid, succinic acid, benzoic acid, quinolinic acid, quinaldic acid, amidosulfuric acid; glycine, alanine, aspartic acid, glutamic acid, lysine, arginine, tryptophan, aromatic amino acid And amino acids such as heterocyclic amino acids. Among these, in consideration of suppression of the generation of ruthenium tetroxide, etc., at least one selected from stearic acid, lauric acid, oleic acid, myristic acid, dodecylbenzenesulfonic acid, alkenyl succinic acid and maleic acid is preferable. . These (B) organic acids may be used individually by 1 type, and may be used in combination of 2 or more type.

(B) The organic acid may be a salt of the organic acid, or may react with a base separately added in the chemical mechanical polishing composition to form a salt of the organic acid. Examples of such bases include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, organic alkali compounds such as tetramethylammonium hydroxide (TMAH), choline, and ammonia. Is mentioned.

The content of the organic acid (B) is preferably 0.001% by mass or more with respect to the total mass of the chemical mechanical polishing composition from the viewpoint of high-speed polishing of a semiconductor substrate containing a metal such as ruthenium. More preferably, it is more preferably at least 0.005% by mass. (B) From the viewpoint of preventing the generation of ruthenium tetroxide, the content of the organic acid is preferably 15% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less.

1.3. (C) Oxidizing agent The chemical mechanical polishing composition according to this embodiment may contain (C) an oxidizing agent within a range in which the ruthenium film is not oxidized during the CMP process to produce ruthenium tetroxide. (C) By containing an oxidizing agent, it is possible to create a fragile modified layer on the surface to be polished by oxidizing a metal such as ruthenium and promoting a complexing reaction with a polishing liquid component. Has the effect of facilitating.

(C) Examples of the oxidizing agent include ammonium persulfate, potassium persulfate, hydrogen peroxide, ferric nitrate, diammonium cerium nitrate, potassium hypochlorite, ozone, potassium periodate, and peracetic acid. . Among these oxidants, at least one selected from potassium periodate, potassium hypochlorite and hydrogen peroxide is preferable, and hydrogen peroxide is more preferable from the viewpoint of suppressing the generation of ruthenium tetroxide. These (C) oxidizing agents may be used individually by 1 type, and may be used in combination of 2 or more type.

In the case of containing (C) an oxidizing agent, the content of the (C) oxidizing agent is the total mass of the chemical mechanical polishing composition from the viewpoint of preventing the oxidation of a metal such as ruthenium from becoming insufficient and reducing the polishing rate. Is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and particularly preferably 0.01% by mass or more. (C) The content of the oxidizing agent is preferably 5% by mass or less, more preferably 3% by mass or less, and particularly preferably 1% by mass or less from the viewpoint of preventing ruthenium tetroxide from being generated due to excessive oxidation of ruthenium. .

1.4. Other Additives The chemical mechanical polishing composition according to the present embodiment includes, in addition to water, which is a main liquid medium, a nitrogen-containing heterocyclic compound, a surfactant, an inorganic acid and a salt thereof, and water-soluble as necessary. It may contain a polymer or the like.

<Water>
The chemical mechanical polishing composition according to this embodiment contains water as a main liquid medium. The water is not particularly limited, but pure water is preferable. Water should just be mix | blended as the remainder of the constituent material of the composition for chemical mechanical polishing mentioned above, and there is no restriction | limiting in particular about content of water.

<Nitrogen-containing heterocyclic compound>
The chemical mechanical polishing composition according to this embodiment may contain a nitrogen-containing heterocyclic compound. By containing a nitrogen-containing heterocyclic compound, excessive etching of a metal such as ruthenium can be suppressed, and surface roughness after polishing such as corrosion can be prevented.

The nitrogen-containing heterocyclic compound is an organic compound containing at least one heterocyclic ring selected from a hetero five-membered ring and a hetero six-membered ring having at least one nitrogen atom. Examples of the heterocyclic ring include hetero five-membered rings such as a pyrrole structure, an imidazole structure, and a triazole structure; and hetero six-membered rings such as a pyridine structure, a pyrimidine structure, a pyridazine structure, and a pyrazine structure. The heterocyclic ring may form a condensed ring. Specific examples include indole structure, isoindole structure, benzimidazole structure, benzotriazole structure, quinoline structure, isoquinoline structure, quinazoline structure, cinnoline structure, phthalazine structure, quinoxaline structure, acridine structure and the like. Of the heterocyclic compounds having such a structure, heterocyclic compounds having a pyridine structure, a quinoline structure, a benzimidazole structure, or a benzotriazole structure are preferable.

Specific examples of nitrogen-containing heterocyclic compounds include aziridine, pyridine, pyrimidine, pyrrolidine, piperidine, pyrazine, triazine, pyrrole, imidazole, indole, quinoline, isoquinoline, benzoisoquinoline, purine, pteridine, triazole, triazolidine, benzotriazole, carboxy Examples thereof include benzotriazole, and further derivatives having these skeletons. Among these, at least one selected from benzotriazole and triazole is preferable. These nitrogen-containing heterocyclic compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

When the nitrogen-containing heterocyclic compound is contained, the content of the nitrogen-containing heterocyclic compound is preferably 0.05 to 2% by mass, more preferably 0.8%, based on the total mass of the chemical mechanical polishing composition. 1 to 1% by mass.

<Surfactant>
The chemical mechanical polishing composition according to this embodiment may contain a surfactant. The surfactant has the effect of imparting an appropriate viscosity to the chemical mechanical polishing composition, suppresses excessive etching of metals such as ruthenium, and prevents surface roughness after polishing such as corrosion. There are cases where it is possible.

The surfactant is not particularly limited, and examples thereof include anionic surfactants, cationic surfactants, and nonionic surfactants. Examples of the anionic surfactant include fatty acid soaps, carboxylates such as alkyl ether carboxylates; sulfonates such as alkylnaphthalene sulfonates and α-olefin sulfonates; higher alcohol sulfates, alkyl ethers. Examples thereof include sulfates such as sulfates and polyoxyethylene alkylphenyl ether sulfates; and fluorine-containing surfactants such as perfluoroalkyl compounds. Examples of the cationic surfactant include aliphatic amine salts and aliphatic ammonium salts. Examples of the nonionic surfactant include nonionic surfactants having a triple bond such as acetylene glycol, acetylene glycol ethylene oxide adduct, and acetylene alcohol; polyethylene glycol type surfactants. These surfactants may be used individually by 1 type, and may be used in combination of 2 or more type.

When the surfactant is contained, the content of the surfactant is preferably 0.001% by mass or more and 5% by mass or less, more preferably 0.001 based on the total mass of the chemical mechanical polishing composition. It is not less than 3% by mass and particularly preferably not less than 0.01% and not more than 1% by mass.

<Inorganic acids and their salts>
The chemical mechanical polishing composition according to this embodiment may contain an inorganic acid and a salt thereof. By containing an inorganic acid and a salt thereof, the polishing rate for a metal such as ruthenium may be further improved. As the inorganic acid, for example, at least one selected from hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid is preferable. As a salt of an inorganic acid, the salt of the above-mentioned inorganic acid may be sufficient, and the base added separately in the chemical mechanical polishing composition and the above-mentioned inorganic acid may form a salt. Examples of such bases include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide; organic alkali compounds such as tetramethylammonium hydroxide (TMAH) and choline, and ammonia. Is mentioned.

When the inorganic acid and the salt thereof are contained, the content of the inorganic acid and the salt is preferably 3 to 8% by mass, more preferably 3 to 6% by mass with respect to the total mass of the chemical mechanical polishing composition. %.

<Water-soluble polymer>
The chemical mechanical polishing composition according to this embodiment may contain a water-soluble polymer. By containing a water-soluble polymer, it may be adsorbed on the surface of a semiconductor substrate (particularly a ruthenium film-containing substrate) to reduce polishing friction. Examples of such water-soluble polymers include polyacrylic acid, polyacrylamide, polyvinyl alcohol, polyvinyl pyrrolidone, polyethyleneimine, polyvinyl methyl ether, polyallylamine, and hydroxyethyl cellulose.

The weight average molecular weight (Mw) of the water-soluble polymer is preferably 1,000 or more and 1,500,000 or less, more preferably 10,000 or more and 500,000 or less, and particularly preferably 30,000 or more and 100 or less. , 000 or less. If the weight average molecular weight of the water-soluble polymer is within the above range, the water-soluble polymer is easily adsorbed to the semiconductor substrate (particularly the ruthenium film-containing substrate), and the polishing friction is further reduced. As a result, generation of polishing flaws on the surface to be polished can be more effectively reduced. In the present specification, “weight average molecular weight (Mw)” refers to a weight average molecular weight in terms of polyethylene glycol measured by GPC (gel permeation chromatography).

The content of the water-soluble polymer is preferably 0.001% by mass or more based on the total mass of the chemical mechanical polishing composition from the viewpoint of effectively obtaining the effect of reducing the occurrence of polishing scratches on the surface to be polished. 0.003% by mass or more is more preferable, and 0.01% by mass or more is particularly preferable. The content of the water-soluble polymer is preferably 1% by mass or less, more preferably 0.5% by mass or less, from the viewpoint of polishing at a sufficient polishing rate while suppressing generation of polishing scratches on the surface to be polished. .1% by mass or less is particularly preferable.

The content of the water-soluble polymer depends on the weight average molecular weight (Mw) of the water-soluble polymer, but is preferably adjusted so that the viscosity of the chemical mechanical polishing composition is less than 10 mPa · s. . When the viscosity of the chemical mechanical polishing composition is less than 10 mPa · s, it is easy to polish a semiconductor substrate (particularly a ruthenium film-containing substrate) at high speed, and the viscosity is appropriate. A composition can be provided.

1.5. pH
The pH of the chemical mechanical polishing composition according to this embodiment is preferably 7 to 13, and more preferably 8 to 12.5. When the pH is 7 or more, the absolute value of the zeta potential of the (A) titanium oxide-containing particles in the chemical mechanical polishing composition is increased and the dispersibility is improved, so that the semiconductor substrate (particularly the ruthenium film-containing substrate) High-speed polishing can be performed while reducing polishing scratches. In particular, in the case of aluminum / titanium oxide-containing particles, when the pH is 7 or more, the absolute value of the zeta potential is particularly increased and the dispersibility is improved. Moreover, if pH is 13 or less, the handleability at the time of production will improve.

The pH of the chemical mechanical polishing composition according to this embodiment can be adjusted by adding, for example, potassium hydroxide, ethylenediamine, TMAH (tetramethylammonium hydroxide), ammonia, or the like. The above can be used.

In the present invention, pH refers to a hydrogen ion index, and the value can be measured using a commercially available pH meter (for example, a desktop pH meter manufactured by Horiba, Ltd.).

1.6. Applications The chemical mechanical polishing composition according to this embodiment can suppress the generation of ruthenium tetroxide, which is highly toxic to the human body, and can polish a ruthenium film-containing substrate at high speed in CMP of a ruthenium film-containing substrate as described above. In addition, polishing scratches on the surface to be polished can be reduced. Therefore, the chemical mechanical polishing composition according to this embodiment is suitable as a polishing material for chemically mechanically polishing a ruthenium film-containing substrate in a semiconductor substrate in which a ruthenium film, which is a next-generation semiconductor material, is applied to a base of a copper film. It is.

1.7. Method for Preparing Chemical Mechanical Polishing Composition The chemical mechanical polishing composition according to this embodiment can be prepared by dissolving or dispersing the above-described components in a liquid medium such as water. The method for dissolving or dispersing is not particularly limited, and any method may be applied as long as it can be uniformly dissolved or dispersed. Further, the mixing order and mixing method of the components described above are not particularly limited.

Also, the chemical mechanical polishing composition according to this embodiment can be prepared as a concentrated type stock solution and diluted with a liquid medium such as water when used.

2. Polishing method
The polishing method according to this embodiment includes a step of polishing a semiconductor substrate using the chemical mechanical polishing composition described above. The chemical mechanical polishing composition described above suppresses the generation of ruthenium tetroxide, which is highly toxic to the human body, and can polish the ruthenium film at high speed when chemically rubbing the ruthenium film-containing substrate. It is possible to reduce polishing scratches. Therefore, the polishing method according to the present embodiment is suitable for polishing a semiconductor substrate in which a ruthenium film, which is a next-generation semiconductor material, is applied to a base of a copper film. Hereinafter, a specific example of the polishing method according to the present embodiment will be described in detail with reference to the drawings.

2.1. FIG. 2 is a cross-sectional view schematically showing a target object suitable for use in the polishing method according to this embodiment. The target object 100 is formed through the following steps (1) to (4).

(1) First, as shown in FIG. 2, a base 10 is prepared. The substrate 10 may be composed of, for example, a silicon substrate and a silicon oxide film formed thereon. Furthermore, a functional device such as a transistor (not shown) may be formed on the base 10. Next, a silicon oxide film 12 that is an insulating film is formed on the substrate 10 by using a thermal oxidation method.

(2) Next, the silicon oxide film 12 is patterned. Using the obtained pattern as a mask, wiring trenches 14 are formed in the silicon oxide film 12 by photolithography.

(3) Next, a ruthenium film 16 is formed on the surface of the silicon oxide film 12 and the inner wall surface of the wiring groove 14. The ruthenium film 16 can be formed, for example, by chemical vapor deposition (CVD) using a ruthenium precursor, atomic layer deposition (ALD), or physical vapor deposition (PVD) such as sputtering.

(4) Next, a 10,000 to 15,000 mm copper film 18 is deposited by chemical vapor deposition or electroplating. As a material of the copper film 18, not only high-purity copper but also an alloy containing copper can be used. The copper content in the alloy containing copper is preferably 95% by mass or more.

2.2. Polishing method 2.2.1. First Polishing Step FIG. 3 is a cross-sectional view schematically showing the workpiece 100 at the end of the first polishing step. As shown in FIG. 3, the first polishing step is a step of polishing the copper film 18 until the ruthenium film 16 is exposed using the chemical mechanical polishing composition for the copper film.

2.2.2. Second Polishing Step FIG. 4 is a cross-sectional view schematically showing the workpiece 100 at the end of the second polishing step. As shown in FIG. 4, the second polishing step is a step of polishing the ruthenium film 16 and the copper film 18 until the silicon oxide film 12 is exposed using the chemical mechanical polishing composition described above. In the second polishing step, since the chemical mechanical polishing composition described above is used, the generation of ruthenium tetroxide, which is highly toxic to the human body, is suppressed, the ruthenium film can be polished at a high speed, and polishing scratches on the surface to be polished can be removed. Can be reduced.

2.3. Chemical Mechanical Polishing Device For the first polishing step and the second polishing step described above, for example, a polishing device 200 as shown in FIG. 5 can be used. FIG. 5 is a perspective view schematically showing the polishing apparatus 200. In the first polishing step and the second polishing step described above, the slurry (chemical mechanical polishing composition) 44 is supplied from the slurry supply nozzle 42, and the semiconductor substrate is rotated while the turntable 48 to which the polishing cloth 46 is attached is rotated. This is done by bringing the carrier head 52 holding 50 into contact. FIG. 5 also shows the water supply nozzle 54 and the dresser 56.

The polishing load of the carrier head 52 can be selected within a range of 0.7 to 70 psi, and preferably 1.5 to 35 psi. Further, the rotation speeds of the turntable 48 and the carrier head 52 can be appropriately selected within the range of 10 to 400 rpm, and preferably 30 to 150 rpm. The flow rate of the slurry (chemical mechanical polishing composition) 44 supplied from the slurry supply nozzle 42 can be selected within the range of 10 to 1,000 mL / min, and preferably 50 to 400 mL / min.

Examples of commercially available polishing apparatuses include: “EPO-112”, “EPO-222” manufactured by Ebara Manufacturing Co., Ltd .; “LGP-510”, “LGP-552” manufactured by Lappmaster SFT, “Applied Materials” Model “Mirra”, “Reflexion”; G & P manufactured by TECHNOLOGY, model “POLI-400L”; manufactured by AMAT, model “Reflexion LK”, and the like.

3. Examples Hereinafter, the present invention will be described by way of examples. However, the present invention is not limited to these examples. In the examples, “parts” and “%” are based on mass unless otherwise specified.

3.1. Preparation of abrasive grains <Preparation of titanium oxide particles A>
The titanyl sulfate solution was hydrolyzed by a conventional method, and 40 kg of a 48% aqueous sodium hydroxide solution was added to 35 kg of hydrous titanium dioxide cake (titanium dioxide hydrate) (10 kg in terms of TiO ₂ ) that had been filtered and washed. The mixture was heated and stirred at a temperature range of 95 to 105 ° C. for 2 hours. The slurry was then filtered and washed thoroughly to obtain a base-treated titanium dioxide hydrate. Water was added to the hydrate cake to make a slurry, and the hydrated TiO ₂ concentration was adjusted to 110 g / L. While stirring the slurry, 35% hydrochloric acid was added to adjust the pH to 7.0.

Next, the slurry was heated to 50 ° C., and 12.5 kg of 35% hydrochloric acid was added at this temperature over 4 minutes with stirring. The hydrochloric acid concentration in the slurry after addition of hydrochloric acid was 40 g / L in terms of 100% HCl. It was made to become. The hydrochloric acid addition rate was 0.11 kg / min per 1 kg of TiO ₂ . Following the addition of hydrochloric acid, the slurry was heated and aged at 100 ° C. for 2 hours. Ammonia water was added to the slurry after aging to neutralize to pH = 6.5. After sufficiently filtering, washing with water, drying and pulverizing with a fluid energy mill, rutile type titanium oxide particles A were obtained.

<Preparation of aluminum / titanium oxide-containing particles B, C, G to I>
The powder obtained by mixing the titanium oxide particles A and aluminum hydroxide obtained above was baked in the range of 100 to 1000 ° C., and then washed with a 1% aqueous sodium hydroxide solution. Subsequently, it was washed with water, dried and pulverized to obtain aluminum / titanium oxide-containing particles. At this time, the mixing ratio of the titanium oxide particles A and aluminum hydroxide is appropriately adjusted, and the firing temperature is appropriately changed within the range of 100 to 1000 ° C., whereby the aluminum / titanium oxide-containing particles B shown in Tables 1 and 2 are used. , C, G to I were obtained respectively.

<Preparation of titanium oxide particles D>
The titanyl sulfate solution was hydrolyzed by a conventional method, and 40 kg of a 48% aqueous sodium hydroxide solution was added to 35 kg of hydrous titanium dioxide cake (titanium dioxide hydrate) (10 kg in terms of TiO ₂ ) that had been filtered and washed. The mixture was heated and stirred at a temperature range of 95 to 105 ° C. for 2 hours. The slurry was then filtered and washed thoroughly to obtain a base-treated titanium dioxide hydrate. Water was added to the hydrate cake to make a slurry, and the hydrated TiO ₂ concentration was adjusted to 110 g / L. While stirring the slurry, 35% hydrochloric acid was added to adjust the pH to 7.0.

Next, the slurry was heated to 50 ° C., and 9.1 kg of 35% hydrochloric acid was added at this temperature over 4 minutes with stirring. The hydrochloric acid concentration in the slurry after addition of hydrochloric acid was 30 g / L in terms of 100% HCl. It was made to become. The hydrochloric acid addition rate is 0.08 kg / min per 1 kg of TiO ₂ . Following the addition of hydrochloric acid, the slurry was heated and aged at 100 ° C. for 2 hours. Ammonia water was added to the slurry after aging to neutralize to pH = 6.5. After sufficiently filtering and washing with water, drying and pulverizing with a fluid energy mill, anatase-type titanium oxide particles D were obtained.

<Preparation of aluminum / titanium oxide-containing particles E and F>
The titanyl sulfate solution was hydrolyzed by a conventional method, and 40 kg of a 48% aqueous sodium hydroxide solution was added to 35 kg of hydrous titanium dioxide cake (titanium dioxide hydrate) (10 kg in terms of TiO ₂ ) that had been filtered and washed. The mixture was heated and stirred at a temperature range of 95 to 105 ° C. for 2 hours. Next, the slurry was filtered and sufficiently washed to obtain base-treated titanium oxide particles. The obtained powder obtained by mixing titanium oxide particles and aluminum hydroxide was baked in the range of 100 to 1000 ° C. and then washed with a 1% aqueous sodium hydroxide solution. Subsequently, it was washed with water, dried and pulverized to obtain aluminum / titanium oxide-containing particles. At this time, the aluminum / titanium oxide-containing particles E and F shown in Table 3 were respectively adjusted by appropriately adjusting the mixing ratio of the titanium oxide particles and aluminum hydroxide and appropriately changing the firing temperature within the range of 100 to 1000 ° C. Obtained.

<Preparation of titanium oxide particles J>
The titanium oxide particles A obtained above were further baked at 550 ° C. to obtain rutile type titanium oxide particles J.

<Silica particles>
To a mixed solution of 787.9 g of pure water, 786.0 g of 26% ammonia water, and 12924 g of methanol, a mixed solution of 1522.2 g of tetramethoxysilane and 413.0 g of methanol was dropped over 55 minutes while maintaining the liquid temperature at 35 ° C. Thus, a silica sol using water and methanol as liquid media was obtained. This silica sol was heated and concentrated to 5000 mL under normal pressure to obtain silica particles.

<Alumina particles>
As the alumina particles, Advanced Alumina Series AA-04 manufactured by Sumitomo Chemical Co., Ltd. was used.

3.2. Evaluation of physical properties of abrasive grains 3.2.1. Measurement of X-ray diffraction intensity of abrasive grains The full width at half maximum of the peak portion where the diffraction intensity in the powder X-ray diffraction pattern of the abrasive grains obtained above was maximum was measured under the following conditions.
(Measurement condition)
Apparatus: Fully automatic horizontal multipurpose X-ray diffractometer SmartLab (manufactured by Rigaku Corporation)
・ X-ray source: 3 kW (water cooling)
・ Measurement method: Powder method using glass sample plate ・ Slit: PB medium resolution ・ Measurement range: 15 to 120 deg
・ Step: 0.05deg
Scan speed: 0.5 deg / min (continuous)

3.2.2. Analysis of Ti / Al molar ratio of aluminum / titanium oxide-containing particles The above-obtained aluminum / titanium oxide-containing particles are dissolved in dilute hydrofluoric acid to obtain ICP-MS (manufactured by PerkinElmer, model number “ELAN DRC PLUS”) Was used to measure the contents of titanium (Ti) and aluminum (Al), and the molar ratio (M _Ti / M _Al ) was calculated.

3.2.3. Measurement of major axis (Rmax) and minor axis (Rmin) of abrasive grains The abrasive grains obtained above were dried and observed with a transmission electron microscope. The major axis (Rmax) and minor axis (Rmin) of 50 abrasive grains were measured by the above-described determination method, and after calculating the average value of the major axis (Rmax) and minor axis (Rmin), the major axis and minor axis were calculated. The ratio (Rmax / Rmin) was calculated.

3.3. Preparation of Chemical Mechanical Polishing Composition A predetermined amount of the abrasive grains produced as described above is added to a polyethylene bottle having a capacity of 1 L, and then each component is added so that the composition shown in Table 1 or Table 2 is obtained. Each example and each comparison were made by adding ammonia as necessary to adjust to the pH shown in Table 1 or 2 and adjusting with pure water so that the total amount of all components was 100 parts by mass. An example chemical mechanical polishing composition was prepared.

3.4. Evaluation method 3.4.1. Polishing Rate Evaluation Using the chemical mechanical polishing composition obtained above, a wafer with a ruthenium film of 50 nm having a diameter of 8 inches was subjected to a chemical mechanical polishing test for 30 seconds under the following polishing conditions.

<Polishing conditions>
・ Polishing device: G & P TECHNOLOGY, model “POLI-400L”
・ Polishing pad: Fuji Spinning Co., Ltd., “Multi-rigid polyurethane pad; H800-type1 (3-1S) 775”
・ Chemical mechanical polishing composition supply rate: 100 mL / min ・ Surface plate rotation speed: 100 rpm
-Head rotation speed: 90 rpm
-Head pressing pressure: 2 psi
Polishing rate (Å / min) = (film thickness before polishing−film thickness after polishing) / polishing time

The thickness of the ruthenium film is determined by the following formula from the sheet resistance value and the volume resistivity of ruthenium by measuring the resistance by a direct current four-probe method using a resistivity measuring device (manufactured by NPS, model “Σ-5”). Calculated by
Film thickness (Å) = [volume resistivity of ruthenium film (Ω · m) ÷ sheet resistance value (Ω)] × 10 ¹⁰

The evaluation criteria for the polishing rate are as follows. Tables 1 to 3 show the ruthenium film polishing rate and its evaluation results.
(Evaluation criteria)
-When the polishing rate is 300 Å / min or more, the polishing rate is high, so in actual semiconductor polishing, the speed balance with the polishing of the other material film can be easily secured, and it is determined to be good because it is practical. It was written.
When the polishing rate was less than 300 Å / min, the polishing rate was low, so that it was difficult to put into practical use and was judged as defective, and indicated as “B”.

3.4.2. Defect Evaluation A wafer with a ruthenium film having a diameter of 12 inches, which is an object to be polished, was polished for 1 minute under the following conditions.
<Polishing conditions>
・ Polishing device: Model “Reflexion LK” manufactured by AMAT
・ Polishing pad: Fuji Spinning Co., Ltd., “Multi-rigid polyurethane pad; H800-type1 (3-1S) 775”
・ Chemical mechanical polishing composition supply rate: 300 mL / min ・ Surface plate rotation speed: 100 rpm
-Head rotation speed: 90 rpm
-Head pressing pressure: 2 psi

About the wafer with a ruthenium film | membrane polished by the above, the total number of defects of 90 nm or more was counted using the defect inspection apparatus (the model "Surfscan SP1" by KLA-Tencor Corporation). The evaluation criteria are as follows. The total number of defects per wafer and the evaluation results are also shown in Tables 1 to 3.
(Evaluation criteria)
The case where the total number of defects per wafer was less than 500 was judged good, and “A” was indicated in the table.
A case where the total number of defects per wafer was 500 or more was judged as defective, and was described as “B” in the table.

3.4.3. Foaming test of chemical mechanical polishing composition 5 mL of the chemical mechanical polishing composition described in Tables 1 to 3 is placed in a transparent plastic container (manufactured by ASONE, 10 mL polystyrene stick bottle), sealed with a lid, Allowed to stand still. One day later, the number of foams adhering to the container wall surface was counted. The evaluation criteria of the foaming test of the chemical mechanical polishing composition are as follows. Tables 1 to 3 also show the number of foaming and the evaluation results.
(Evaluation criteria)
-When the number of foams was less than 3, since the generation of gas was small, it was determined to be good because it was practical and indicated as "A".
-When the number of foams was 3 or more, gas generation was large, so it was not practical, so it was judged as bad, and indicated as "B".

3.4.4. Corrosion Evaluation The wafer with the ruthenium film 50 nm was cut into 1 cm × 1 cm to obtain a metal wafer test piece. The surface of this test piece was observed in advance with a scanning electron microscope at a magnification of 50,000 times. Next, 50 mL of the chemical mechanical polishing composition of each Example and each Comparative Example was put in a polyethylene container and kept at 25 ° C., a metal wafer specimen (1 cm × 1 cm) was immersed for 60 minutes, and washed with running water for 10 seconds. After drying, the surface corrosion state was observed with a scanning electron microscope at a magnification of 50,000 times, and evaluated according to the following criteria. The evaluation results are also shown in Tables 1 to 3.
(Evaluation criteria)
A: No change in surface shape due to corrosion was observed compared to before immersion.
-B: The location which has corroded compared with the place before immersion, and the location which has not corroded were mixed.
-C: The whole surface was corroded compared with before immersion.

3.5. Evaluation results Tables 1 to 3 show the compositions of the chemical mechanical polishing compositions of the examples and the comparative examples and the evaluation results.

The following products or reagents were used for the respective components in Tables 1 to 3.
<Abrasive grains>
Titanium oxide particles A to J: Titanium oxide particles A to J produced above
・ Silica: Silica particles prepared above ・ Alumina: Sumitomo Chemical Co., Ltd., Advanced Alumina series product name “AA-04”
<Organic acid>
・ Stearic acid: Wako Pure Chemical Industries, Ltd., trade name “Stearic acid”
・ Lauric acid: Wako Pure Chemical Industries, Ltd., trade name “Lauric acid”
-Myristic acid: Wako Pure Chemical Industries, Ltd., trade name "Myristic acid"
・ Ammonium dodecylbenzenesulfonate: manufactured by Tokyo Chemical Industry Co., Ltd., trade name “Sodium Dodecylbenzenesulfonate”
・ Dipotassium alkenyl succinate: product name “Latemul ASK” manufactured by Kao Corporation
<Oxidizing agent>
・ Hydrogen peroxide: Wako Pure Chemical Industries, Ltd., trade name “hydrogen peroxide”
-Potassium periodate: Wako Pure Chemical Industries, Ltd., trade name "potassium periodate"
-Potassium hypochlorite: manufactured by Kanto Chemical Co., Ltd., trade name "potassium hypochlorite solution"
<Other additives>
Benzotriazole: Wako Pure Chemical Industries, Ltd., trade name “1H-benzotriazole”, nitrogen-containing heterocyclic compound, acetylenic diol-based nonionic surfactant: Nissin Chemical Industry Co., Ltd., trade name “Surfinol 485 ”, Surfactant / polyacrylic acid: manufactured by Toa Gosei Co., Ltd., trade name“ Julimer AC-10L ”, weight average molecular weight (Mw) = 50,000
-Polyvinylpyrrolidone (K30): Nippon Shokubai Co., Ltd., trade name "Polyvinylpyrrolidone K-30", water-soluble polymer

In Examples 1 to 19, by using a chemical mechanical polishing composition containing titanium oxide-containing particles and an organic acid having a half-value width of less than 1 ° in the peak portion where the diffraction intensity in the powder X-ray diffraction pattern is maximum, It was found that the ruthenium film can be polished at a high speed and polishing scratches on the surface to be polished can be reduced.

Comparative Example 1 is an example in which a chemical mechanical polishing composition containing titanium oxide particles A having a half-width of less than 1 ° at the peak portion where the diffraction intensity in the powder X-ray diffraction pattern is maximum and containing no organic acid is used. It is. In this case, since the organic acid was not contained, the ruthenium film could not be polished at a high speed, and in the defect evaluation, many defects were recognized on the surface of the surface to be polished.

Comparative Example 2 is an example using a chemical mechanical polishing composition containing silica particles and an organic acid (stearic acid). In this case, the ruthenium film could not be polished at high speed because the mechanical polishing force of the silica particles was too low.

Comparative Example 3 is an example in which a chemical mechanical polishing composition containing alumina particles and an organic acid (stearic acid) having a half-value width of less than 1 ° at the peak portion where the diffraction intensity is maximum in the powder X-ray diffraction pattern is used. is there. In this case, since the mechanical polishing power of the alumina particles is too low, the ruthenium film cannot be polished at a high speed, and in the defect evaluation, a large number of defects were found on the surface of the surface to be polished.

Comparative Example 4 is a chemical mechanical polishing composition containing aluminum / titanium oxide-containing particles E having a half-value width of 2.1 ° at the peak portion where the diffraction intensity is maximum in the powder X-ray diffraction pattern and an organic acid (stearic acid). It is an example using a thing. In this case, since the hardness of the aluminum / titanium oxide-containing particles E was low and the mechanical polishing power was too low, the ruthenium film could not be polished at high speed.

Comparative Example 5 is a chemical mechanical polishing composition containing aluminum / titanium oxide-containing particles F having a half-value width of 1.4 ° at the peak portion where the diffraction intensity is maximum in the powder X-ray diffraction pattern and an organic acid (stearic acid). It is an example using a thing. In this case, since the hardness of the aluminum / titanium oxide-containing particles F was slightly lowered, the ruthenium film could not be polished at high speed, and in the defect evaluation, many defects were recognized on the surface of the surface to be polished. .

Comparative Example 6 and Comparative Example 7 are examples in which the titanium oxide particles A having a half-value width of less than 1 ° at the peak portion where the diffraction intensity is maximum in the powder X-ray diffraction pattern, and nitric acid and sulfuric acid were used in place of the organic acid, respectively. It is. In this case, a number of defects were observed on the surface of the surface to be polished due to the etching action of nitric acid or sulfuric acid.

From the above results, it was found that the chemical mechanical polishing composition according to the present invention can polish a semiconductor substrate (particularly a ruthenium film-containing substrate) at high speed and reduce polishing scratches on the surface to be polished.

The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 1 ... Titanium oxide containing particle, 10 ... Base | substrate, 12 ... Silicon oxide film, 14 ... Groove for wiring, 16 ... Ruthenium film, 18 ... Copper film, 42 ... Slurry supply nozzle, 44 ... Slurry (chemical mechanical polishing composition) 46 ... Polishing cloth, 48 ... Turntable, 50 ... Semiconductor substrate, 52 ... Carrier head, 54 ... Water supply nozzle, 56 ... Dresser, 100 ... Object to be processed, 200 ... Polishing apparatus

Claims

(A) titanium oxide-containing particles;
(B) an organic acid;
Containing
The chemical mechanical polishing composition according to (A), wherein the titanium oxide-containing particles have a peak width at which the diffraction intensity in the powder X-ray diffraction pattern is maximum of less than 1 °.
The (A) titanium oxide-containing particles further contain aluminum,
The value of M Ti / M Al is 6 to 70, when the number of moles of titanium in the (A) titanium oxide-containing particles is M Ti and the number of moles of aluminum is M Al . Chemical mechanical polishing composition.
3. The chemical machine according to claim 1, wherein a ratio (Rmax / Rmin) of a major axis (Rmax) to a minor axis (Rmin) of the (A) titanium oxide-containing particles is 1.1 to 4.0. Polishing composition.
Furthermore, the chemistry of any one of Claims 1 thru | or 3 which contains 0.001 mass% or more and 5 mass% or less of (C) oxidizing agent with respect to the total mass of the composition for chemical mechanical polishing. Mechanical polishing composition.
The chemical mechanical polishing composition according to claim 4, wherein the (C) oxidizing agent is at least one selected from potassium periodate, potassium hypochlorite and hydrogen peroxide.
The content of the (A) titanium oxide-containing particles is 0.1% by mass or more and 10% by mass or less based on the total mass of the chemical mechanical polishing composition. The composition for chemical mechanical polishing described in 1.
The chemical mechanical polishing composition according to any one of claims 1 to 6, wherein the pH is 7 or more and 13 or less.
The chemical mechanical polishing composition according to any one of claims 1 to 7, which is used for polishing a semiconductor substrate containing a ruthenium film.
A polishing method comprising a step of polishing a semiconductor substrate using the chemical mechanical polishing composition according to any one of claims 1 to 7.
The polishing method according to claim 9, wherein the semiconductor substrate includes a ruthenium film.