TW201943829A - Chemical mechanical polishing composition and polishing method - Google Patents

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 DEG.

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 the manufacturing technology of semiconductor integrated circuits, high integration and high-speed operation of semiconductor elements are required. Along with this, the flatness of the surface of the semiconductor substrate required in the manufacturing step of the microcircuit of the semiconductor element becomes stricter, and chemical mechanical polishing (CMP) has become an indispensable technique in the manufacturing step of the semiconductor element.

CMP is a method that supplies a polishing composition containing abrasive particles or reagents to a polishing pad while pushing a semiconductor substrate onto a polishing pad adhered to a platen, sliding the semiconductor substrate and the polishing pad to each other, and chemically and chemically polishing the semiconductor substrate. Technology of mechanical grinding. In CMP, the surface of the semiconductor substrate is cut by the chemical reaction of the reagents and the mechanical polishing of the abrasive grains to flatten the surface.

In the miniaturized semiconductor market, semiconductor substrates with a tip node of a circuit line width of 10 nm have become mainstream. In addition, in order to realize fine wiring with a circuit line width of 10 nm or less, a technique for improving the embedding property of a copper film by applying a ruthenium film having low resistance to copper substrates and good compatibility with copper has been studied.

Against this background, a ruthenium film polishing composition (slurry) has been studied to planarize a ruthenium film as a next-generation semiconductor material by CMP (for example, refer to Patent Documents 1 to 2). As a composition for polishing such a ruthenium film, in order to increase the polishing speed of the ruthenium film, a slurry using abrasive grains such as alumina or titanium oxide and an oxidizing agent in combination has been studied.
[Prior Art Literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2009-514219
[Patent Document 2] Japanese Patent Publication No. 2010-535424

[Problems to be Solved by the Invention]

However, in CMP, in order to increase the polishing speed of the ruthenium film, it is necessary to use a ruthenium film polishing composition containing an oxidizing agent with a high oxidizing power and / or abrasive particles with high hardness. However, in a CMP using a ruthenium film polishing composition containing an oxidizing agent having a high oxidizing power, there is a problem that ruthenium tetraoxide, which is highly toxic to the human body, tends to be generated, which hinders the production process. In addition, in CMP using a ruthenium film polishing composition containing abrasive particles having high hardness, there is a problem that polishing damage easily occurs on the surface to be polished after polishing.

Furthermore, when titanium oxide particles are used as the abrasive particles, since the surface is chemically active, it is easy to react with water, oxygen, nitrogen, etc., and there is a possibility that workability during production is easily impaired due to foaming or the like. Topic.

Therefore, it is an object of several aspects of the present invention to provide a method for suppressing the generation of ruthenium tetroxide, which is highly toxic to humans, and capable of high-speed polishing of semiconductor substrates (especially substrates containing a ruthenium film) and reducing polishing of the surface to be polished Damaged chemical mechanical polishing composition and polishing method using the same. In addition to the above-mentioned objects, some aspects of the present invention further provide a chemical mechanical polishing composition having excellent stability with reduced occurrence of blistering.
[Means for solving problems]

The present invention has been made to solve at least a part of the problems described above, and can be implemented in the following forms or application examples.

[Application Example 1]
One form of the chemical mechanical polishing composition of the present invention contains:
(A) titanium oxide-containing particles; and (B) organic acids,
In the (A) titanium oxide-containing particles, the half-value width of the peak portion where the diffraction intensity in the powder X-ray diffraction pattern becomes maximum is less than 1 °.

[Application Example 2]
In the chemical mechanical polishing composition of the application example, it may be:
The (A) titanium oxide-containing particles further contain aluminum,
In the (A) particles containing titanium oxide, the number of moles of titanium to M _Ti, when the number of moles of aluminum to M _Al, M _Ti / M _Al is 6 ~ 70.

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

[Application Example 4]
In the chemical mechanical polishing composition of the application example, it may be:
It further contains (C) an oxidizing agent in an amount of 0.001% by mass or more and 5% by mass or less based on the total mass of the composition for chemical mechanical polishing.

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

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

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

[Application Example 8]
The chemical mechanical polishing composition of the application example may be:
For polishing a semiconductor substrate containing a ruthenium film.

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

[Application Example 10]
In the grinding method of the application example, it may be:
The semiconductor substrate includes a ruthenium film.
[Effect of the invention]

According to an aspect of the composition for chemical mechanical polishing of the present invention, the generation of ruthenium tetroxide, which is highly toxic to the human body, is suppressed, and a semiconductor substrate, particularly a substrate containing a ruthenium film, can be polished at high speed and the polishing of the surface to be polished can be reduced. damage. Furthermore, according to one aspect of the chemical mechanical polishing composition of the present invention, in addition to the effects described above, it is possible to produce a chemical mechanical polishing composition having excellent stability with reduced occurrence of foaming. Furthermore, according to an aspect of the polishing method of the present invention, by using the chemical mechanical polishing composition, a semiconductor substrate, particularly a substrate containing a ruthenium film, can be polished at high speed, and flat and have a high total throughput. Ground.

Hereinafter, suitable embodiments of the present invention will be described in detail. In addition, the present invention is not limited to the embodiments described below, but also includes various modifications implemented within a range that does not change the gist of the present invention.

In this specification, the numerical range described using "~" means the meaning including the numerical value before and after "~" as a lower limit and an upper limit.

1. Composition for chemical mechanical polishing The composition for chemical mechanical polishing of the present embodiment contains (A) titanium oxide-containing particles and (B) organic acid, and among the (A) titanium oxide-containing particles, powder X-rays The half-value width of the peak portion where the diffraction intensity in the radiation pattern becomes the largest is less than 1 °. Hereinafter, each component contained in the chemical-mechanical polishing composition of this embodiment is demonstrated in detail.

1.1. (A) Titanium oxide-containing particles The chemical mechanical polishing composition according to this embodiment contains (A) titanium oxide-containing particles. The "(A) titanium oxide-containing particle" in the present invention may be a particle composed of only titanium oxide, or may be a particle containing a compound other than titanium oxide. (A) As the titanium oxide contained in the titanium oxide-containing particles, any of a rutile type, an anatase type, an amorphous type, and a mixture thereof may be used.

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

In addition, the powder X-ray diffraction pattern refers to each incident angle in a two-dimensional graph in which the incident angle is the horizontal axis and the diffraction intensity is the vertical axis when the sample is measured by powder X-ray diffraction. Plot line of measured diffraction intensity.

In the (A) titanium oxide-containing particles of the present embodiment, when the major axis of the (A) titanium oxide-containing particles is Rmax and the short axis is Rmin, the ratio of the long axis to the short axis (Rmax / Rmin) ) Is 1.1 to 4.0, more preferably 1.5 to 3.8, and even more 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 substrate with a ruthenium film can be polished at a high speed. If the ratio of the major axis to the minor axis (Rmax / Rmin) is 4.0 or less, it can be suppressed to (A) The entanglement of the ends of the titanium oxide-containing particles can reduce the polishing damage on the surface to be polished of the substrate containing a ruthenium film.

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

(A) The major axis (Rmax) and minor axis (Rmin) of titanium oxide-containing particles can be measured as follows. For example, as shown in FIG. 1, when an image of an independent titanium oxide-containing particle 1 taken by a transmission electron microscope is elliptical, the major axis a of the elliptical shape is determined to be titanium oxide-containing. The major axis (Rmax) of the particles 1 is identified as the minor axis (Rmin) of the titanium oxide-containing particles 1 with the minor axis b of the elliptical shape. With this discrimination method, for example, the long diameter (Rmax) and short diameter (Rmin) of 50 titanium oxide-containing particles can be measured, and the average of the long diameter (Rmax) and short diameter (Rmin) can be calculated and calculated. Find the ratio of the major axis to the minor axis (Rmax / Rmin).

In the case where (A) 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, and nitride Aluminum compounds such as aluminum, aluminum acetate, aluminum phosphate, aluminum sulfate, sodium aluminate, and potassium aluminate. In this specification, (A) titanium oxide-containing particles containing an aluminum compound are also referred to as "aluminum / titanium oxide-containing particles".

In the case where (A) the titanium oxide-containing particles are aluminum / titanium oxide-containing particles, when the aluminum / titanium oxide-containing particles are used, the molar number of titanium is M _Ti and the molar number of aluminum is M when _{a l,} M _Ti value / M _Al is preferably from 6 to 70, more preferably 10 to 65, and particularly preferably 20 to 60. When the value of M _Ti / M _Al is 6 or more, sufficient hardness for polishing can be obtained. Therefore, a substrate containing a ruthenium film can be polished at a high speed, and particles containing titanium oxide become chemically inert. As a result, it can be suppressed. Bubbling occurs. When the value of M _Ti / M _Al is 70 or less, the agglomeration of particles containing aluminum / titanium oxide can be suppressed, so that the polishing damage of the surface to be polished can be reduced.

The value of M _Ti / M _Al can be obtained by dissolving aluminum / titanium oxide-containing particles with dilute hydrofluoric acid, and using an inductively coupled plasma mass spectrometer (Inductively Coupled Plasma-Mass Spectrometry, ICP-MS) (Inductively Coupled Plasma Mass Spectrometer: for example, model "ELAN DRC PLUS" manufactured by PerKinElmer) measures the content of titanium and aluminum in aluminum / titanium-containing particles, and based on the measured values And figure it out.

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

From the viewpoint, the absolute value of the kinetic potential of the aluminum / titanium-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, Particularly preferred is above 35 mV. In the chemical mechanical polishing composition in the pH range, if the absolute value of the kinetic potential of the aluminum / titanium oxide-containing particles is 25 mV or more, the dispersibility of the aluminum / titanium oxide-containing particles is improved, and High-speed polishing while reducing polishing damage of semiconductor substrates (especially substrates containing a ruthenium film).

(A) The average particle diameter of the titanium oxide-containing particles is preferably from 10 nm to 300 nm, more preferably from 20 nm to 200 nm, and even more preferably from 25 nm to 150 nm. When it is (A) titanium oxide-containing particles having an average particle diameter within the above range, a sufficient polishing rate can be obtained, and a chemical mechanical polishing composition having excellent stability without particle precipitation and separation can be obtained. , So good performance can be achieved. The average particle diameter of (A) titanium oxide-containing particles can be obtained, for example, by using a flow-type specific surface area automatic measurement device ("micrometrics flow adsorption II2300 (Shimadzu Corporation)" manufactured by Shimadzu Corporation "), Measured by the Brunauer-Emmett-Teller (BET) method, and calculated based on the measured surface area.

From the viewpoint of polishing semiconductor substrates at a high speed, the content of (A) titanium oxide-containing particles is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, relative to the total mass of the composition for chemical mechanical polishing. , Particularly preferably 0.5 mass% or more. From the viewpoint of reducing the occurrence of abrasive damage on the surface to be polished, the content of (A) titanium oxide-containing particles is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.

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

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

Specific examples of (B) organic acids include stearic acid, lauric acid, oleic acid, myristic acid, dodecylbenzenesulfonic acid, alkenylsuccinic acid, lactic acid, tartaric acid, fumaric acid, and 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, 2-quinolinic acid, aminosulfonic acid (Amidosulfuric acid); amino acids such as glycine, alanine, aspartic acid, glutamic acid, lysine, arginine, tryptophan, aromatic amino acid and heterocyclic amino acid. Among these, in consideration of suppressing the production of ruthenium tetraoxide, etc., it is preferably selected from the group consisting of stearic acid, lauric acid, oleic acid, myristic acid, dodecylbenzenesulfonic acid, alkenylsuccinic acid, and malay. At least one of acids. These (B) organic acids may be used alone or in combination of two or more.

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

From the viewpoint of high-speed polishing of a semiconductor substrate containing a metal such as ruthenium, the content of (B) organic acid is preferably 0.001% by mass or more, more preferably 0.003% by mass, relative to the total mass of the composition for chemical mechanical polishing. The above is particularly preferably 0.005% by mass or more. From the viewpoint of preventing the generation of ruthenium tetroxide, the content of the (B) organic acid is preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less.

1.3. (C) Oxidizing agent The chemical mechanical polishing composition according to the present embodiment may contain (C) an oxidizing agent within a range that does not oxidize the ruthenium film to generate ruthenium tetraoxide in the CMP step. The inclusion of an (C) oxidant oxidizes metals such as ruthenium and promotes a complex reaction with the polishing liquid component, thereby making it possible to produce a fragile modified layer on the surface to be polished, thereby having the effect of facilitating polishing.

Examples of the (C) oxidant include ammonium persulfate, potassium persulfate, hydrogen peroxide, iron nitrate, diammonium cerium nitrate, potassium hypochlorite, ozone, potassium periodate, and peracetic acid. Among these oxidizing agents, at least one selected from the group consisting of potassium periodate, potassium hypochlorite, and hydrogen peroxide, and more preferably hydrogen peroxide, from the viewpoint of suppressing the production of ruthenium tetraoxide. These (C) oxidants may be used singly or in combination of two or more kinds.

In the case where the (C) oxidant is contained, the content of the (C) oxidant is preferably relative to the total mass of the chemical mechanical polishing composition from the viewpoint of preventing insufficient oxidation of metals such as ruthenium and lowering the polishing rate. It is 0.001 mass% or more, more preferably 0.005 mass% or more, and even more preferably 0.01 mass% or more. From the viewpoint of preventing ruthenium tetraoxide from being generated due to excessive oxidation of ruthenium, the content of the (C) oxidant is preferably 5 mass% or less, more preferably 3 mass% or less, and even more preferably 1 mass% or less.

1.4. Other Additives The chemical mechanical polishing composition according to this embodiment may contain a nitrogen-containing heterocyclic compound, a surfactant, an inorganic acid and a salt thereof, and a water-soluble polymer, in addition to water as a main liquid medium. .

＜ Water ＞
The composition for chemical mechanical polishing of the present embodiment contains water as a main liquid medium. The water is not particularly limited, but pure water is preferred. Water may be prepared as the remainder of the constituent material of the chemical mechanical polishing composition, and the content of water is not particularly limited.

<Nitrogen-containing heterocyclic compound>
The composition for chemical mechanical polishing of this embodiment may contain a nitrogen-containing heterocyclic compound. By containing a nitrogen-containing heterocyclic compound, it is possible to suppress excessive etching of metals such as ruthenium, and to prevent surface roughness after polishing such as corrosion.

The nitrogen-containing heterocyclic compound is an organic compound having at least one nitrogen atom and containing at least one heterocyclic ring selected from a five-membered heterocyclic ring and a six-membered heterocyclic ring. Examples of the heterocyclic ring include five-membered heterocyclic rings such as a pyrrole structure, an imidazole structure, and a triazole structure; and six-membered heterocyclic rings such as a pyridine structure, a pyrimidine structure, a pyridazine structure, and a pyrazine structure. The heterocyclic ring may also form a fused ring. Specific examples include an indole structure, an isoindole structure, a benzimidazole structure, a benzotriazole structure, a quinoline structure, an isoquinoline structure, a quinazoline structure, a perylene structure, a phthalazine structure, and a quinone. Oxaline structure, acridine structure, etc. Among heterocyclic compounds having such a structure, preferred are heterocyclic compounds having a pyridine structure, a quinoline structure, a benzimidazole structure, and a benzotriazole structure.

Specific examples of the nitrogen-containing heterocyclic compound include aziridine, pyridine, pyrimidine, pyrrolidine, piperidine, pyrazine, triazine, pyrrole, imidazole, indole, quinoline, isoquinoline, and benzoiso Quinoline, purine, pyridine, triazole, triazolidine, benzotriazole, carboxybenzotriazole, and the like, and further include derivatives having these skeletons. Among these, at least one kind selected from benzotriazole and triazole is preferable. These nitrogen-containing heterocyclic compounds may be used singly or in combination of two or more kinds.

When the nitrogen-containing heterocyclic compound is contained, the content of the nitrogen-containing heterocyclic compound is preferably 0.05% to 2% by mass, and more preferably 0.1% to 1% by mass relative to the total mass of the chemical mechanical polishing composition. %.

＜ Surface active agent ＞
The composition for chemical mechanical polishing of the present embodiment may also contain a surfactant. In addition to the effect of imparting moderate viscosity to the composition for chemical mechanical polishing, the surfactant may suppress excessive etching of metals such as ruthenium, and may prevent surface roughness after polishing such as corrosion.

The surfactant is not particularly limited, and examples thereof include an anionic surfactant, a cationic surfactant, and a nonionic surfactant. Examples of the anionic surfactant include carboxylic acid salts such as fatty acid soaps and alkyl ether carboxylic acid salts; sulfonic acid salts such as alkyl naphthalenesulfonic acid salts and α-olefin sulfonic acid salts; higher alcohol sulfate salts and alkanes Sulfates such as alkyl ether sulfates and polyoxyethylene alkylphenyl ether sulfates; fluorine-containing surfactants such as perfluoroalkyl compounds. Examples of the cationic surfactant include an aliphatic amine salt and an aliphatic ammonium salt. 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 surfactants Wait. These surfactants may be used singly or in combination of two or more kinds.

In the case of having a surfactant, the content of the surfactant is preferably 0.001% by mass or more and 5% by mass or less, more preferably 0.001% by mass or more and 3% by mass relative to the total mass of the chemical mechanical polishing composition. Hereinafter, it is particularly preferably from 0.01% by mass to 1% by mass.

＜ Inorganic acids and their salts ＞
The composition for chemical mechanical polishing of the present embodiment may contain an inorganic acid and a salt thereof. By containing an inorganic acid and a salt thereof, the polishing rate for metals such as ruthenium may be further increased. The inorganic acid is preferably at least one selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, for example. The salt of the inorganic acid may be the salt of the inorganic acid, or a salt may be formed from a base added separately to the composition for chemical mechanical polishing and the inorganic acid. Examples of such a base include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide; organic base compounds such as tetramethylammonium hydroxide (TMAH) and choline; and ammonia.

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

＜ Water-soluble polymer ＞
The composition for chemical mechanical polishing of this embodiment may contain a water-soluble polymer. By containing a water-soluble polymer, the surface may be adsorbed on the surface of a semiconductor substrate (especially a substrate containing a ruthenium film), thereby reducing polishing friction. Examples of such water-soluble polymers include polyacrylic acid, polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, polyethyleneimine, polyvinylmethyl ether, polyallylamine, and hydroxyl groups. Ethyl cellulose, etc.

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 even more preferably 30,000 or more and 100,000 or less. When the weight-average molecular weight of the water-soluble polymer is within the above range, the water-soluble polymer will be easily adsorbed on a semiconductor substrate (especially a substrate containing a ruthenium film), thereby further reducing polishing friction. As a result, it is possible to more effectively reduce the occurrence of polishing damage on the surface to be polished. The "weight average molecular weight (Mw)" in this specification refers to a weight average molecular weight in terms of polyethylene glycol measured by gel permeation chromatography (GPC).

From the viewpoint of effectively reducing the occurrence of abrasion damage on the surface to be polished, the content of the water-soluble polymer is preferably 0.001% by mass or more relative to the total mass of the chemical mechanical polishing composition. It is 0.003 mass% or more, and particularly preferably 0.01 mass% or more. From the viewpoint of suppressing the occurrence of polishing damage to the surface to be polished and polishing at a sufficient polishing rate, the content of the water-soluble polymer is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.1. Mass% or less.

The content of the water-soluble polymer also depends on the weight-average molecular weight (Mw) of the water-soluble polymer, but it is preferably adjusted so that the viscosity of the composition for chemical mechanical polishing is less than 10 mPa · s. If the viscosity of the chemical mechanical polishing composition is less than 10 mPa · s, the semiconductor substrate (especially a substrate containing a ruthenium film) can be easily polished at a high speed, and the chemical mechanical polishing can be stably supplied to the polishing cloth due to the reasonable viscosity. Using composition.

1.5.pH
The pH of the chemical mechanical polishing composition of the present 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 kinetic potential of the (A) titanium oxide-containing particles in the chemical mechanical polishing composition becomes larger and the dispersibility is improved. Therefore, it is possible to reduce semiconductor substrates (especially substrates containing ruthenium film) ) Abrasive damage and high-speed grinding. Among them, in the case of aluminum / titanium oxide-containing particles, when the pH is 7 or more, the absolute value of the dynamic potential increases, and dispersibility is improved. When the pH is 13 or less, the workability during production is improved.

In addition, the pH of the chemical mechanical polishing composition of the present embodiment can be adjusted by adding, for example, potassium hydroxide, ethylenediamine, TMAH (tetramethylammonium hydroxide), ammonia, etc., and one or more of these can be used. .

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

1.6. Application The chemical mechanical polishing composition of the present embodiment suppresses the generation of ruthenium tetroxide, which is highly toxic to the human body, in the CMP of a substrate containing a ruthenium film, as described above, and can perform high-speed processing on a substrate containing a ruthenium film. Grinding, and can reduce the abrasive damage of the surface to be polished. Therefore, the composition for chemical mechanical polishing of this embodiment is suitable as a polishing material for chemical mechanical polishing of a substrate containing a ruthenium film in a semiconductor substrate obtained by applying a ruthenium film as a next-generation semiconductor material to the base of a copper film. .

1.7. Preparation method of chemical mechanical polishing composition The chemical mechanical polishing composition according to the present embodiment can be prepared by dissolving or dispersing the respective components in a liquid medium such as water. The method of dissolving or dispersing is not particularly limited, and any method can be applied as long as the dissolving or dispersing can be performed uniformly. Moreover, there is no restriction | limiting in particular also about the mixing order or mixing method of each said component.

In addition, the chemical mechanical polishing composition according to the present embodiment can also be prepared as a concentrated stock solution, and when used, it is diluted with a liquid medium such as water and 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. When the chemical mechanical polishing composition is used to chemically and mechanically polish a substrate containing a ruthenium film, the occurrence of ruthenium tetroxide, which is highly toxic to the human body, is suppressed, and the ruthenium film can be polished at high speed and the polishing damage of the surface to be polished can be reduced . Therefore, the polishing method of this embodiment is suitable for polishing a semiconductor substrate obtained by applying a ruthenium film as a next-generation semiconductor material to the base of a copper film. Hereinafter, a specific example of the polishing method according to this embodiment will be described in detail using drawings.

2.1. Object to be processed FIG. 2 is a cross-sectional view schematically showing an object to be treated suitable for using the polishing method of the present embodiment. The object to be processed 100 is formed through the following steps (1) to (4).

(1) First, as shown in FIG. 2, a substrate 10 is prepared. The base body 10 may include, 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 body 10. Next, a silicon oxide film 12 as an insulating film is formed on the substrate 10 using a thermal oxidation method.

(2) Next, the silicon oxide film 12 is patterned. Using the obtained pattern as a mask, a wiring groove 14 was formed on the silicon oxide film 12 by a photolithography method.

(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 by, for example, a chemical vapor deposition method (CVD) or an atomic layer deposition method (ALD) using a ruthenium precursor, or a physical vapor deposition method (Physical Vapor Deposition) such as sputtering. , PVD) to form.

(4) Next, a copper film 18 of 10,000 Å to 15,000 Å is deposited by a chemical vapor deposition method or a plating method. As the 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 copper-containing gold is preferably 95% by mass or more.

2.2. Grinding method
2.2.1. First polishing step FIG. 3 is a cross-sectional view schematically showing the object 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 using the chemical mechanical polishing composition for a copper film until the ruthenium film 16 is exposed.

2.2.2. Second polishing step FIG. 4 is a cross-sectional view schematically showing the object 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. In the second polishing step, the chemical mechanical polishing composition is used, so that generation of ruthenium tetroxide, which is highly toxic to the human body, is suppressed, the ruthenium film can be polished at high speed, and the polishing damage of the surface to be polished can be reduced.

2.3. Chemical mechanical polishing device In the first polishing step and the second polishing step, 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, a slurry (composition for chemical mechanical polishing) 44 is supplied from a slurry supply nozzle 42, and the turntable 48 with the polishing cloth 46 attached thereto is rotated while being held while rotating The carrier head 52 of the semiconductor substrate 50 comes into contact with each other. FIG. 5 also shows the water supply nozzle 54 and the dresser 56 together.

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

Examples of commercially available polishing devices include models "EPO-112" and "EPO-222" manufactured by Hagiwara Corporation; models "LGP-510" and "LGP-552" manufactured by lapmaster SFT "Models" Mirra "and" Reflexion "manufactured by Applied Material;" POLI-400L "models manufactured by G & P Technology;" Models manufactured by AMAT " Reflexion LK "and so on.

3. Examples Hereinafter, the present invention will be described by examples, but the present invention is not limited to these examples at all. In addition, "part" and "%" in this embodiment are quality standards unless otherwise specified.

3.1. Preparation of abrasive particles <Preparation of titanium oxide particles A>
In a conventional method, the titanyl sulfate solution was hydrolyzed, and in a water-containing titanium dioxide filter cake (titanium dioxide hydrate) 35 kg (10 kg in terms of TiO ₂ conversion) after filtering and washing, 48% sodium hydroxide was added while stirring. The aqueous solution was 40 kg, followed by heating and stirring at a temperature range of 95 ° C to 105 ° C for 2 hours. Then, this slurry was filtered and sufficiently washed to obtain an alkali-treated titanium dioxide hydrate. This hydrate cake was slurried by adding water, and adjusted to a TiO ₂ equivalent concentration of 110 g / L. While stirring the slurry, 35% hydrochloric acid was added to make pH 7.0.

Next, the slurry was heated to 50 ° C, and at this temperature, 12.5 kg of 35% hydrochloric acid was added for 4 minutes while stirring, so that the concentration of hydrochloric acid in the slurry after adding hydrochloric acid was 40 g / 100% HCl conversion L. The addition rate of hydrochloric acid was set to 0.11 kg / minute per kg of TiO ₂ conversion. After adding hydrochloric acid, the slurry was heated, and then aged at 100 ° C for 2 hours. Aqueous ammonia was added to the aged slurry, and neutralization was performed at pH = 6.5. After sufficient filtration, washing with water, and drying, pulverization was performed with a fluid energy mill to obtain rutile titanium oxide particles A.

<Preparation of aluminum / titanium oxide-containing particles B, aluminum / titanium oxide-containing particles C, aluminum / titanium oxide-containing particles G to aluminum / titanium oxide-containing particles I>
The powder obtained by mixing the obtained titanium oxide particles A and aluminum hydroxide in a range of 100 ° C to 1000 ° C is calcined, and then washed with a 1% sodium hydroxide aqueous solution. Then, washing with water, drying, and pulverization were performed to obtain aluminum / titanium oxide-containing particles. At this time, the mixing ratio of titanium oxide particles A and aluminum hydroxide was appropriately adjusted, and the firing temperature was appropriately changed in the range of 100 ° C to 1000 ° C, thereby obtaining aluminum / titanium oxide-containing Particles B, aluminum / titanium oxide-containing particles C, aluminum / titanium oxide-containing particles G to aluminum / titanium oxide-containing particles I.

<Preparation of Titanium Oxide Particle D>
In a conventional method, the titanyl sulfate solution was hydrolyzed, and in a water-containing titanium dioxide filter cake (titanium dioxide hydrate) 35 kg (10 kg in terms of TiO ₂ conversion) after filtering and washing, 48% sodium hydroxide was added while stirring. The aqueous solution was 40 kg, followed by heating and stirring at a temperature range of 95 ° C to 105 ° C for 2 hours. Then, this slurry was filtered and sufficiently washed to obtain an alkali-treated titanium dioxide hydrate. This hydrate cake was slurried by adding water, and adjusted to a TiO ₂ equivalent concentration of 110 g / L. While stirring the slurry, 35% hydrochloric acid was added to make pH 7.0.

Next, the slurry was heated to 50 ° C, and at this temperature, while stirring, 35% hydrochloric acid 9.1 kg was added for 4 minutes, so that the concentration of hydrochloric acid in the slurry after adding hydrochloric acid became 30 g / L. The addition rate of hydrochloric acid was set to 0.08 kg / minute per kg of TiO ₂ conversion. After adding hydrochloric acid, the slurry was heated, and then aged at 100 ° C for 2 hours. Aqueous ammonia was added to the aged slurry, and neutralization was performed at pH = 6.5. After sufficient filtration, washing with water, and drying, pulverization was performed with a fluid energy mill to obtain anatase titanium oxide particles D.

<Preparation of aluminum / titanium oxide-containing particle E and aluminum / titanium oxide-containing particle F>
In a conventional method, the titanyl sulfate solution was hydrolyzed, and in a water-containing titanium dioxide filter cake (titanium dioxide hydrate) 35 kg (10 kg in terms of TiO ₂ conversion) after filtering and washing, 48% sodium hydroxide was added while stirring. The aqueous solution was 40 kg, followed by heating and stirring at a temperature range of 95 ° C to 105 ° C for 2 hours. Then, this slurry was filtered and sufficiently washed to obtain alkali-treated titanium oxide particles. The powder obtained by mixing the obtained titanium oxide particles and aluminum hydroxide in a range of 100 ° C to 1000 ° C is calcined, and then washed with a 1% sodium hydroxide aqueous solution. Then, washing with water, drying, and pulverization were performed to obtain aluminum / titanium oxide-containing particles. At this time, the mixing ratio of titanium oxide particles and aluminum hydroxide is appropriately adjusted, and the firing temperature is appropriately adjusted within a range of 100 ° C to 1000 ° C, thereby obtaining aluminum / titanium oxide-containing particles shown in Table 2 E. Particles F containing aluminum / titanium oxide.

<Preparation of Titanium Oxide Particles J>
Furthermore, the obtained titanium oxide particles A were baked at 550 ° C to obtain rutile titanium oxide particles J.

＜ Silicon dioxide particles ＞
Regarding a mixed liquid of 1522.2 g of tetramethoxysilane and 413.0 g of methanol, the liquid temperature was maintained at 35 ° C. and it was added dropwise to the mixed liquid of 787.9 g of pure water, 786.0 g of 26% ammonia water, and 12,924 g of methanol to obtain Silica sol with water and methanol as liquid medium. This silica sol was heated and concentrated to 5000 mL under normal pressure to obtain silica dioxide particles.

<Alumina particles>
The alumina particles are the Advanced Alumina series AA-04 manufactured by Sumitomo Chemical Co., Ltd.

3.2. Evaluation of physical properties of abrasive particles
3.2.1. Measurement of X-ray Diffraction Intensity of Abrasive Particles The half-value width of the peak portion where the diffraction intensity in the powder X-ray diffraction pattern of the abrasive particles obtained as described above becomes the maximum is measured under the following conditions.
(Measurement conditions)
· Device: Full-automatic horizontal multipurpose X-ray diffraction device SmartLab (manufactured by Rigaku)
X-ray source: 3 kw (water-cooled)
· Measurement method: Powder method using glass sample plate · Slit: Resolution in PB · Measurement range: 15 deg ～ 120 deg
Step: 0.05 deg
Scan speed: 0.5 deg / min (continuous)

3.2.2. Ti / Al molar ratio analysis of aluminum / titanium oxide-containing particles The aluminum / titanium oxide-containing particles obtained above were dissolved in dilute hydrofluoric acid, and were analyzed by ICP-MS (PerkinElmer ( The model "ELAN DRC PLUS" manufactured by Perkinelmer) measures the content of titanium (Ti) and aluminum (Al) to calculate the molar ratio (M _Ti / M _Al ).

3.2.3. Measurement of the long diameter (Rmax) and short diameter (Rmin) of the abrasive grains The abrasive grains obtained above were dried and observed with a transmission electron microscope. According to the determination method shown above, the major diameter (Rmax) and minor diameter (Rmin) of 50 abrasive particles were measured, and the average of the major diameter (Rmax) and minor diameter (Rmin) was calculated. Ratio of long diameter to short diameter (Rmax / Rmin).

3.3. Preparation of chemical mechanical polishing composition A predetermined amount of the abrasive grains produced as described above are added to a polyethylene bottle having a capacity of 1 L, and then each component is added so as to have a composition shown in Table 1 or Table 2. Then, if necessary, ammonia was added to adjust the pH to be as shown in Table 1 or Table 2, and adjusted with pure water so that the total amount of all components became 100 parts by mass, thereby preparing each Example and each Comparative Example A Chemical Mechanical Polishing Composition.

3.4. Evaluation method
3.4.1. Evaluation of polishing rate Using the chemical mechanical polishing composition obtained above, a chemical mechanical polishing test was performed for 30 seconds under the following polishing conditions using a wafer having a diameter of 8 inches and a ruthenium film at 50 nm as the object to be polished.

＜ Polishing conditions ＞
· Grinding device: Model "POLI-400L" manufactured by G & P Technology
· Polishing pads: "Multi-rigid polyurethane pads; H800-typel (3-1S) 775" manufactured by Fuji Textile Co., Ltd.
· Chemical mechanical polishing composition supply speed: 100 mL / min · Platen rotation speed: 100 rpm
Grinding head speed: 90 rpm
Grinding head pressure: 2 psi
· Grinding speed (Å / min) = (thickness of the film before grinding-thickness of the film after grinding) / grinding time

In addition, the thickness of the ruthenium film was measured by a resistivity measuring machine (model "Σ-5" manufactured by NPS Corporation) using a direct current four-probe method, and based on the sheet resistance value and the volume resistivity of ruthenium It is calculated by the following formula.

Film thickness (Å) = [Volume resistivity of ruthenium film (Ω ･ m) ÷ sheet resistance value (Ω)] × 10 ¹⁰

The evaluation criteria of the polishing rate are as follows. The polishing speed of the ruthenium film and the evaluation results thereof are shown in Tables 1 to 3 together.
(Evaluation criteria)
· When the polishing speed is 300 Å / min or more, the polishing speed is large. Therefore, it is easy to ensure the actual semiconductor polishing with the polishing speed balance of other material films. It is usable and judged as good. "A".
· When the polishing speed is less than 300 Å / min, the polishing speed is small, so it is difficult to use, but it is judged as defective, and it is marked "B".

3.4.2. Defect Evaluation A 12-inch-diameter wafer with a ruthenium film, which is the object to be polished, was polished for one minute under the following conditions.
＜ Polishing conditions ＞
· Grinding device: Model "Reflexion LK" manufactured by AMAT
· Polishing pads: "Multi-rigid polyurethane pads; H800-typel (3-1S) 775" manufactured by Fuji Textile Co., Ltd.
· Chemical mechanical polishing composition supply speed: 300 mL / min · Platen rotation speed: 100 rpm
Grinding head speed: 90 rpm
Grinding head pressure: 2 psi

For the wafers with a ruthenium film polished as described above, the total number of defects with a size of 90 nm or more was counted using a defect inspection device (model "Surfscan SP1" manufactured by KLA Tencor) . The evaluation criteria are as follows. The total number of defects per unit wafer and the evaluation results are shown in Tables 1 to 3.
(Evaluation criteria)
• The case where the total number of defects per unit wafer is less than 500 is judged to be good, and it is described as "A" in the table.
• The case where the total number of defects per unit wafer is 500 or more is judged to be defective, and it is described as "B" in the table.

3.4.3. Foaming test of chemical mechanical polishing composition Put 5 mL of the chemical mechanical polishing composition described in Tables 1 to 3 into a transparent plastic container (10 mL of styrene manufactured by ASONE) Stick bottle), sealed with a cap, and left for one day. After one day, the number of bubbles attached to the container wall was counted. The evaluation criteria of the foaming test of the composition for chemical mechanical polishing are as follows. The number of bubbles and the evaluation results are shown in Tables 1 to 3.
(Evaluation criteria)
-When the number of bubbles is less than three, gas generation is small, so it is practical, and it is judged as good from this, and it is marked with "A".
• When the number of bubbles is 3 or more, gas generation is large, and therefore it is not practical. Therefore, it is judged as defective, and it is marked "B".

3.4.4. Corrosion evaluation The 50 nm wafer with a ruthenium film was cut into 1 cm × 1 cm to prepare 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. Then, 50 mL of the chemical mechanical polishing composition of each example and each comparative example were put into a polyethylene container, and kept at 25 ° C, and a metal wafer test piece (1 cm × 1 cm) was immersed for 60 minutes. After washing with running water for 10 seconds and drying it, the state of corrosion on the surface was observed with a scanning electron microscope at a magnification of 50,000 times, and the evaluation was performed based on the following criteria. The evaluation results are shown in Tables 1 to 3 together.
(Evaluation criteria)
A: No change in the shape of the surface due to corrosion was observed compared to before immersion.
· B: Compared with the state before immersion, there are both a corroded part and a non-corroded part.
C: The entire surface is corroded compared to before immersion.

3.5. Evaluation Results Tables 1 to 3 show the composition of the chemical mechanical polishing composition of each example and each comparative example and the evaluation results.

[Table 1]

[Table 2]

[table 3]

For each component in Tables 1 to 3, the following products or reagents were used.
＜ Abrasive grains ＞
Titanium oxide particles A to titanium oxide particles J: The titanium oxide particles A to titanium oxide particles J produced above
· Silicon dioxide: silica particles produced as above · Alumina: Advanced Alumina series manufactured by Sumitomo Chemical Co., Ltd. under the trade name "AA-04"
＜ Organic acid ＞
· Stearic acid: manufactured by Wako Pure Chemical Industries, Ltd., trade name "stearic acid"
· Lauric acid: manufactured by Wako Pure Chemical Industries, Ltd., trade name "lauric acid"
· Myristic acid: manufactured by Wako Pure Chemical Industries, Ltd., trade name "Myristic Acid"
· Ammonium dodecylbenzenesulfonate: manufactured by Tokyo Chemical Industry Co., Ltd. under the trade name "Sodium Dodecylbenzenesulfonate"
· Dipotassium alkenyl succinate: manufactured by Kao Corporation under the trade name "LATEMUL" ASK "
<Oxidant>
· Hydrogen peroxide: manufactured by Wako Pure Chemical Industries, Ltd., trade name "Hydrogen peroxide"
· Potassium periodate: manufactured by Wako Pure Chemical Industries, Ltd., trade name "Potassium Periodate"
Potassium hypochlorite: manufactured by Kanto Chemical Co., Ltd. under the trade name "potassium hypochlorite solution"
＜ Other additives ＞
Benzotriazole: manufactured by Wako Pure Chemical Industries, Ltd., trade name "1H-benzotriazole", nitrogen-containing heterocyclic compound, acetylene glycol-based nonionic surfactant: Nissin Chemical Industry Co., Ltd Manufactured under the trade name "Surfynol 485", surfactant and polyacrylic acid: manufactured by Toa Synthesis Co., Ltd. under the trade name "Jurymer AC-10L", weight average molecular weight (Mw) = 50,000
· Polyvinylpyrrolidone (K30): manufactured by Japan Catalyst Co., Ltd. under the trade name "Polyvinylpyrrolidone K-30", a water-soluble polymer

In Examples 1 to 19, it was found that by using the powder containing X-ray diffraction patterns, the peak intensity at which the diffraction intensity becomes maximum has a half-value width of less than 1 ° and the chemistry of the titanium oxide-containing particles and the organic acid The composition for mechanical polishing can perform high-speed polishing of the ruthenium film and reduce the polishing damage of the surface to be polished.

Comparative Example 1 is an example of using a chemical mechanical polishing composition containing titanium oxide particles A having a half-value width of less than 1 ° at the half-value width of the peak portion where the diffraction intensity in the powder X-ray diffraction pattern is the largest, without containing an organic acid. In this case, since no organic acid is contained, high-speed polishing of the ruthenium film cannot be performed, and many defects were confirmed on the surface of the surface to be polished in the defect evaluation.

Comparative Example 2 is an example using a composition for chemical mechanical polishing containing silicon dioxide particles and an organic acid (stearic acid). In this case, the mechanical polishing force of the silicon dioxide particles is too low, so that the ruthenium film cannot be polished at high speed.

Comparative Example 3 is an example of a composition for chemical mechanical polishing using alumina particles and organic acids (stearic acid) containing an alumina particle having a half-value width of less than 1 ° at the peak portion where the diffraction intensity in the powder X-ray diffraction pattern is the largest. . In this case, since the mechanical polishing force of the alumina particles is too low, high-speed polishing of the ruthenium film cannot be performed, and in the defect evaluation, many defects were confirmed on the surface of the surface to be polished.

Comparative Example 4 is a chemical-mechanical polishing using aluminum / titanium-containing particles E and an organic acid (stearic acid) containing an aluminum / titanium oxide particle having a half-value width of 2.1 ° at the peak portion where the diffraction intensity in the powder X-ray diffraction pattern is maximized. Example of composition. In this case, the hardness of the particles E containing aluminum / titanium oxide is low, and the mechanical polishing force is too low, so that the ruthenium film cannot be polished at high speed.

Comparative Example 5 is a chemical-mechanical polishing using aluminum / titanium-containing particles F and organic acids (stearic acid) containing a particle having a half-value width of 1.4 ° at the peak portion where the diffraction intensity in the powder X-ray diffraction pattern is the largest. Example of composition. In this case, the hardness of the particles F containing aluminum / titanium oxide is slightly lowered, so that the ruthenium film cannot be polished at high speed, and many defects were confirmed on the surface of the surface to be polished in the defect evaluation.

Comparative Example 6 and Comparative Example 7 are examples in which titanium oxide particles A having a diffraction peak intensity in a powder X-ray diffraction pattern having a maximum peak value with a half-value width of less than 1 ° and using nitric acid and sulfuric acid instead of organic acids are used . In this case, many defects were confirmed on the surface of the surface to be polished due to the etching effect of nitric acid or sulfuric acid.

From the above results, it can be seen that the chemical mechanical polishing composition of the present invention can perform high-speed polishing of a semiconductor substrate (especially a substrate containing a ruthenium film), and can reduce the polishing damage of the surface to be polished.

The present invention is not limited to the embodiment described above, and various modifications are possible. For example, the present invention includes a configuration substantially the same as the configuration described in the embodiment (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect). The present invention includes a configuration in which non-essential parts of the configuration described in the embodiment are replaced. The present invention includes a configuration that exhibits the same function and effect as the configuration described in the embodiment or a configuration that achieves the same purpose. The present invention includes a configuration obtained by adding a known technique to the configuration described in the embodiment.

1‧‧‧ particles containing titanium oxide

10‧‧‧ Matrix

12‧‧‧ silicon oxide film

14‧‧‧Wiring slot

16‧‧‧Ruthenium film

18‧‧‧ copper film

42‧‧‧ slurry supply nozzle

44‧‧‧ slurry (composition for chemical mechanical polishing)

46‧‧‧ abrasive cloth

48‧‧‧ Turntable

50‧‧‧ semiconductor substrate

52‧‧‧Carrier head

54‧‧‧Water supply nozzle

56‧‧‧Finisher

100‧‧‧ object

200‧‧‧ grinding device

a‧‧‧long axis

b‧‧‧ short axis

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 treated to which the polishing method of the embodiment is suitable.

FIG. 3 is a cross-sectional view schematically showing an object to be processed at the end of the first polishing step.

FIG. 4 is a cross-sectional view schematically showing an object to be processed at the end of the second polishing step.

FIG. 5 is a perspective view schematically showing a chemical mechanical polishing apparatus.

Claims (10)

A chemical mechanical polishing composition containing: (A) particles containing titanium oxide; and (B) organic acids, In the (A) titanium oxide-containing particles, the half-value width of the peak portion where the diffraction intensity in the powder X-ray diffraction pattern becomes maximum is less than 1 °. The chemical mechanical polishing composition according to item 1 of the scope of patent application, wherein the (A) titanium oxide-containing particles further contain aluminum, and among the (A) titanium oxide-containing particles, ear set the number M _Ti, when the number of moles of aluminum to M _Al, M _Ti / M _Al is 6 ~ 70. The chemical mechanical polishing composition according to item 1 or 2 of the scope of patent application, wherein (A) the ratio of the major axis (Rmax) to the minor axis (Rmin) of the titanium oxide-containing particles (Rmax / Rmin) ) Is 1.1 to 4.0. The chemical mechanical polishing composition according to any one of claims 1 to 3, further comprising 0.001% by mass or more and 5% by mass or less based on the total mass of the chemical mechanical polishing composition. (C) oxidant. The chemical mechanical polishing composition according to item 4 of the scope of patent application, wherein the (C) oxidant is at least one selected from potassium periodate, potassium hypochlorite, and hydrogen peroxide. The chemical mechanical polishing composition according to any one of claims 1 to 5, wherein the content of the (A) titanium oxide-containing particles is relative to the total mass of the chemical mechanical polishing composition. It is 0.1 mass% or more and 10 mass% or less. The chemical mechanical polishing composition according to any one of claims 1 to 6 in the scope of the patent application, 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 of the scope of patent application, which is used for polishing a semiconductor substrate including a ruthenium film. A polishing method including the step of polishing a semiconductor substrate using the chemical mechanical polishing composition according to any one of claims 1 to 7 of the scope of patent application. The polishing method according to item 9 of the scope of patent application, wherein the semiconductor substrate includes a ruthenium film.