CMP polishing liquid, CMP polishing liquid set and polishing method

Abstract

A polishing liquid for CMP, the polishing liquid containing abrasive grains, an additive and water, wherein: the abrasive grains contain cerium particles; and the additive contains (A1) a 4-pyrone compound represented by general formula (1) and (B) a compound having two or more nitrogen atoms, each of which is bonded with a hydroxyalkyl group. A polishing liquid for CMP, the polishing liquid containing abrasive grains, an additive and water, wherein: the abrasive grains contain cerium particles; and the additive contains (A2) picolinic acid and (B) a compound having two or more nitrogen atoms, each of which is bonded with a hydroxyalkyl group. (In the formula, each of X11, X12 and X13 independently represents a hydrogen atom or a monovalent substituent.)

Description

[Technical field]

[0001] The present disclosure relates to a polishing liquid for CMP (chemical mechanical polishing), a polishing liquid set for CMP, a polishing method, and the like. [Background technology]

[0002] In the field of semiconductor manufacturing, as the performance of ultra-LSI devices improves, it is becoming increasingly difficult to achieve both high integration and high speed using miniaturization technology, which is an extension of conventional technology. Therefore, technology is being developed to achieve high integration in the vertical direction (i.e., technology to create multiple layers of wiring) while continuing to miniaturize semiconductor elements.

[0003] One of the most important technologies in the process of manufacturing devices with multi-layered wiring is CMP technology. CMP technology is a technology to flatten the surface of a substrate obtained by forming a thin film on a substrate by chemical vapor deposition (CVD) or other methods. For example, flattening by CMP is essential to ensure the depth of focus in lithography. If the surface of the substrate is uneven, it may cause inconveniences such as making it impossible to focus in the exposure process or not being able to form a fine wiring structure sufficiently. In addition, CMP technology is also applied to the process of forming element isolation (inter-element isolation; STI: shallow trench isolation) regions by polishing plasma oxide films (BPSG, HDP-SiO2, p-TEOS, etc.) in the device manufacturing process; the process of forming ILD films (interlayer insulating films; insulating films that electrically insulate metal members (wiring, etc.) from each other in the same layer); and the process of flattening plugs (e.g. Al / Cu plugs) after embedding a film containing silicon oxide in metal wiring.

[0004] CMP is usually performed using an apparatus capable of supplying a polishing liquid onto a polishing pad. The surface of the substrate is polished by pressing the substrate against the polishing pad while supplying the polishing liquid between the substrate surface and the polishing pad. Thus, the polishing liquid is one of the elemental technologies in the CMP technology, and various polishing liquids have been developed to obtain high-performance polishing liquids (for example, see Patent Document 1 below).

[0005] Among the processes to which the CMP technology as described above is applied, in particular, in the CMP process of an ILD film, it is necessary to polish silicon oxide at a high polishing rate. Therefore, in the CMP process of an ILD film, a silica-based polishing liquid (polishing liquid using abrasive grains containing silica-based particles) having a high polishing rate is mainly used (see, for example, Patent Document 2 below). However, with a silica-based polishing liquid, it tends to be difficult to control polishing scratches, which are the cause of defects. In addition, with the recent miniaturization of wiring, it is desirable to reduce polishing scratches in the CMP process of an ILD film, but unlike the CMP process of an insulating film for an element isolation region, finishing mirror polishing is generally not performed. Therefore, the use of a cerium-based polishing liquid (polishing liquid using abrasive grains containing cerium-based particles), which causes fewer polishing scratches than a silica-based polishing liquid, is being considered (see, for example, Patent Document 3 below). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-288537 A [Patent Document 2] Japanese Patent Application Publication No. 9-316431 [Patent Document 3] Japanese Patent Application Publication No. 10-102038 Summary of the Invention [Problem to be solved by the invention]

[0007] However, with a cerium-based polishing liquid, it may be difficult to achieve a high removal rate of silicon oxide, particularly when polishing a patterned wafer having a fine uneven pattern composed of convex portions (e.g., line portions) and concave portions (e.g., space portions), it may be difficult to achieve a high removal rate of silicon oxide on the convex portions.

[0008] An object of one aspect of the present disclosure is to provide a CMP polishing liquid capable of achieving a high polishing rate of silicon oxide of convex portions in polishing a patterned wafer having a fine concave-convex pattern. Another object of the present disclosure is to provide a CMP polishing liquid set for obtaining the CMP polishing liquid. Still another object of the present disclosure is to provide a polishing method using the CMP polishing liquid or the CMP polishing liquid set. [Means for solving the problem]

[0009] The present disclosure relates in some aspects to the following items [1] to

[17] , etc. [1] A polishing liquid for CMP comprising an abrasive grain, an additive, and water, wherein the abrasive grain contains cerium-based particles, and the additive contains (A1) a 4-pyrone-based compound represented by the following general formula (1), and (B) a compound having two or more nitrogen atoms bonded to a hydroxyalkyl group: [ka] [In the formula, X 11 , X 12 and X 13 are each independently a hydrogen atom or a monovalent substituent. [2] The polishing liquid for CMP according to [1], wherein the component (A1) contains at least one member selected from the group consisting of 3-hydroxy-2-methyl-4-pyrone, 5-hydroxy-2-(hydroxymethyl)-4-pyrone, and 2-ethyl-3-hydroxy-4-pyrone. [3] The polishing slurry for CMP according to [1] or [2], wherein the content of the component (A1) is 0.01 to 5 mass %. [4] The polishing liquid for CMP according to any one of [1] to [3], wherein the component (B) contains ethylenedinitrilotetraethanol. [5] The polishing liquid for CMP according to any one of [1] to [4], wherein the component (B) contains ethylenedinitrilotetrapropanol. [6] The polishing liquid for CMP according to any one of [1] to [5], wherein the content of the component (B) is 0.001 to 5 mass %. [7] The polishing liquid for CMP according to any one of [1] to [6], wherein the additive further contains a saturated monocarboxylic acid. [8] The polishing liquid for CMP according to any one of [1] to [7], which has a pH of 8.0 or less. [9] A polishing liquid for CMP comprising an abrasive grain, an additive, and water, wherein the abrasive grain contains cerium-based particles, and the additive contains (A2) picolinic acid and (B) a compound having two or more nitrogen atoms bonded to hydroxyalkyl groups.

[10] The polishing slurry for CMP according to [9], wherein the content of the component (A2) is 0.001 to 5 mass %.

[11] The polishing liquid for CMP according to [9] or

[10] , wherein the component (B) contains ethylenedinitrilotetraethanol.

[12] The polishing liquid for CMP according to any one of [9] to

[11] , wherein the component (B) contains ethylenedinitrilotetrapropanol.

[13] The polishing liquid for CMP according to any one of [9] to

[12] , wherein the content of the component (B) is 0.001 to 5 mass %.

[14] The polishing liquid for CMP according to any one of [9] to

[13] , which has a pH of 8.0 or less.

[15] A polishing liquid set for CMP, in which the components of the polishing liquid for CMP described in any one of [1] to

[14] are stored separately as a first liquid and a second liquid, the first liquid containing the abrasive grains and water, and the second liquid containing at least one of the additives and water.

[16] A polishing method comprising a step of polishing a surface to be polished using the polishing liquid for CMP according to any one of [1] to

[14] or the polishing liquid for CMP obtained by mixing the first liquid and the second liquid in the polishing liquid set for CMP according to

[15] .

[17] The polishing method according to

[16] , wherein the surface to be polished contains silicon oxide. Effect of the Invention

[0010] According to one aspect of the present disclosure, it is possible to provide a CMP polishing liquid capable of achieving a high polishing rate of silicon oxide of convex portions in polishing a patterned wafer having a fine concave-convex pattern. According to another aspect of the present disclosure, it is possible to provide a CMP polishing liquid set for obtaining the CMP polishing liquid. Furthermore, according to another aspect of the present disclosure, it is possible to provide a polishing method using the CMP polishing liquid or the CMP polishing liquid set. [Brief description of the drawings]

[0011] [Figure 1] 1A to 1C are schematic cross-sectional views showing a process of polishing an ILD film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be described in detail.

[0013] In this specification, a numerical range indicated by using "~" indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. "A or more" of a numerical range means A and a range exceeding A. "A or less" of a numerical range means A and a range less than A. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value of a numerical range at a certain step can be arbitrarily combined with the upper limit value or the lower limit value of a numerical range at another step. In the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. "A or B" means that either one of A and B may be included, or both may be included. The materials exemplified in this specification can be used alone or in combination of two or more thereof unless otherwise specified. The content of each component in the composition means the total amount of the plurality of substances corresponding to each component in the composition when there are a plurality of substances corresponding to each component in the composition unless otherwise specified. The terms "layer" or "film" include, when observed as a plan view, not only a structure formed over the entire surface but also a structure formed partially. The term "step" includes not only an independent step but also the step even when it cannot be clearly distinguished from other steps as long as the intended action of the step is achieved. The "hydroxy group" (hydroxyl group) does not include the OH structure contained in the carboxy group.

[0014] <CMP Polishing Liquid> The CMP polishing liquid according to this embodiment (first and second embodiments, hereinafter the same) is a CMP polishing liquid (hereinafter sometimes simply referred to as "polishing liquid") containing abrasive grains, an additive, and water. The abrasive grains include cerium-based particles (particles containing a cerium-based compound). The additive of the polishing liquid according to the first embodiment includes (A1) a 4-pyrone-based compound represented by the following general formula (1) (component (A1)) and (B) a compound having two or more nitrogen atoms to which a hydroxyalkyl group is bonded (component (B)). The additive of the polishing liquid according to the second embodiment includes (A2) picolinic acid (component (A2)) and (B) a compound having two or more nitrogen atoms to which a hydroxyalkyl group is bonded (component (B)). The additive of the polishing liquid according to this embodiment may include component (A1), component (A2), and component (B).

[0015] [ka] [In the formula, X 11 , X 12 and X 13 are each independently a hydrogen atom or a monovalent substituent.

[0016] The polishing liquid according to this embodiment can achieve a high polishing rate for silicon oxide on the convex portions when polishing a patterned wafer having a fine uneven pattern composed of convex portions (e.g., line portions) and concave portions (e.g., space portions), and can achieve a high polishing rate for silicon oxide on the convex portions when polishing, for example, a region of a line / space (L / S)=30 μm / 570 μm on a patterned wafer. The polishing liquid according to this embodiment can achieve a polishing rate for silicon oxide on the convex portions in a region of L / S=30 μm / 570 μm of, for example, 2100 nm / min or more in the evaluation method described in the examples below.

[0017] The factors that enable a high polishing rate of silicon oxide of the convex parts to be achieved are not necessarily clear, but are presumed to be as follows. However, the factors are not limited to the following. That is, according to the polishing liquid of this embodiment, the interaction between the polishing liquid and the silicon oxide of the convex parts is increased due to the synergistic effect caused by the combined use of the (A1) component and the (B) component, or the synergistic effect caused by the combined use of the (A2) component and the (B) component (for example, the chemical reaction (reaction derived from the Si-O-Ce bond) between the cerium-based particles in the polishing liquid and the silicon oxide of the convex parts is promoted), so that a high polishing rate of silicon oxide of the convex parts can be obtained, and a high polishing rate of silicon oxide of the convex parts can be achieved in polishing the region of L / S=30 μm / 570 μm on a pattern wafer.

[0018] According to one aspect of the polishing liquid of this embodiment, high-speed polishing of silicon oxide on a blanket wafer not having a concave-convex pattern (e.g., a polishing rate of 100 nm / min or more (preferably 250 nm / min or more)) can be achieved, while a high polishing rate of silicon oxide on convex portions can be achieved in polishing an L / S=30 μm / 570 μm region on a patterned wafer.

[0019] The polishing liquid according to the present embodiment can be used in the CMP of semiconductor wafer materials, for example, to polish a silicon oxide film provided on the surface of a semiconductor wafer. The polishing liquid according to the present embodiment can be used in the CMP process of an ILD film.

[0020] (Abrasive grain) The abrasive grains include cerium-based particles. By using cerium-based particles as the abrasive grains, it is easy to obtain a high removal rate of silicon oxide on the convex portions of the patterned wafer while reducing polishing scratches on the surface to be polished.

[0021] Examples of the cerium-based compound of the cerium-based particles include cerium oxide, cerium hydroxide, ammonium cerium nitrate, cerium acetate, cerium sulfate hydrate, cerium bromate, cerium bromide, cerium chloride, cerium oxalate, cerium nitrate, and cerium carbonate. The cerium-based particles may contain cerium oxide from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex parts of the patterned wafer (such as convex parts in the region of L / S=30 μm / 570 μm; the same applies below). By using cerium-based particles (cerium oxide particles) containing cerium oxide, it is easy to achieve a high polishing rate of silicon oxide on the convex parts of the patterned wafer, and it is easy to obtain a polished surface with few polishing scratches and excellent flatness.

[0022] The cerium oxide particles may include polycrystalline cerium oxide having grain boundaries. Such polycrystalline cerium oxide particles have the property of becoming finer during polishing and simultaneously revealing active surfaces one after another, and can maintain a high polishing rate for silicon oxide on the convex portions of the patterned wafer.

[0023] Examples of methods for producing cerium oxide particles include a calcination method and an oxidation method using hydrogen peroxide or the like. When calcination is performed, the temperature during calcination may be 350 to 900° C. When the produced cerium oxide particles are aggregated, the particles may be mechanically pulverized. The pulverization method may be, for example, dry pulverization using a jet mill or the like, or wet pulverization using a planetary bead mill or the like. As the jet mill, for example, one described in "Chemical Engineering Journal," Vol. 6, No. 5, (1980), pp. 527-532, can be used.

[0024] The zeta potential (surface potential) of the abrasive grains in the polishing liquid may be positive (the zeta potential may exceed 0 mV) from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex parts of the patterned wafer. The zeta potential of the abrasive grains can be measured, for example, using a dynamic light scattering zeta potential measuring device (for example, manufactured by Beckman Coulter, Inc., product name: DelsaNano C). The zeta potential of the abrasive grains can be adjusted using an additive. For example, an abrasive grain having a positive zeta potential can be obtained by contacting the abrasive grains with an acid component (for example, acetic acid).

[0025] The average particle size of the abrasive grains may be 50 nm or more, 70 nm or more, 100 nm or more, more than 100 nm, 105 nm or more, 110 nm or more, 115 nm or more, 120 nm or more, 125 nm or more, 130 nm or more, 135 nm or more, or 140 nm or more, from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex parts of the patterned wafer. The average particle size of the abrasive grains may be 500 nm or less, 300 nm or less, 200 nm or less, 180 nm or less, 150 nm or less, or 140 nm or less, from the viewpoint of easily suppressing the occurrence of polishing scratches. From these viewpoints, the average particle size of the abrasive grains may be 50 to 500 nm, 50 to 200 nm, 50 to 150 nm, 70 to 500 nm, 70 to 200 nm, 70 to 150 nm, 100 to 500 nm, 100 to 200 nm, or 100 to 150 nm. By adjusting the average particle size of the abrasive grains, a high polishing rate and low scratch characteristics of silicon oxide corresponding to the average particle size of the abrasive grains can be efficiently obtained.

[0026] The "average particle size of abrasive grains" refers to the median value of the volume distribution measured by a laser diffraction / scattering particle size distribution measuring device for a sample of a slurry in which the abrasive grains are dispersed, and can be measured using a device such as Microtrac MT3300EXII (trade name) manufactured by MicrotracBEL Corp. For example, a sample is prepared by dispersing the abrasive grains in water to adjust the content of the abrasive grains so that the content of the abrasive grains is 0.25% by mass based on the total mass of the sample, and this sample is set in the measuring device to measure the median value of the volume distribution. When measuring the particle size of the abrasive grains in the polishing liquid, a sample is prepared by adjusting the content of the abrasive grains in the polishing liquid so that the content of the abrasive grains is 0.25% by mass based on the total mass of the sample, and this sample can be used for measurement in the same manner.

[0027] The content of the abrasive grains may be within the following ranges based on the total mass of the polishing liquid, from the viewpoint of achieving an excellent balance between the polishing rate of silicon oxide on the convex parts of the patterned wafer and the dispersion stability of the abrasive grains. The content of the abrasive grains may be 0.01 mass% or more, 0.05 mass% or more, 0.1 mass% or more, 0.15 mass% or more, 0.2 mass% or more, 0.25 mass% or more, 0.3 mass% or more, 0.5 mass% or more, 0.8 mass% or more, or 1 mass% or more. The content of the abrasive grains may be 10 mass% or less, 5 mass% or less, 3 mass% or less, 1 mass% or less, 0.8 mass% or less, 0.5 mass% or less, 0.3 mass% or less, or 0.25 mass% or less. From these viewpoints, the content of the abrasive grains may be 0.01 to 10 mass%, 0.01 to 2 mass%, 0.01 to 1 mass%, 0.01 to 0.5 mass%, 0.1 to 10 mass%, 0.1 to 2 mass%, 0.1 to 1 mass%, 0.1 to 0.5 mass%, 0.5 to 10 mass%, 0.5 to 2 mass%, or 0.5 to 1 mass%.

[0028] (Additives) [Component (A1): 4-pyrone compound] The additive for the polishing liquid according to the first embodiment contains a 4-pyrone-based compound represented by general formula (1) (hereinafter, sometimes simply referred to as "4-pyrone-based compound") as component (A1). It is presumed that the use of a 4-pyrone-based compound increases the interaction between the polishing liquid and silicon oxide, which tends to increase the polishing rate. In addition, although a 4-pyrone-based compound is an additive that can increase the interaction between the polishing liquid and silicon oxide, it does not have the effect of weakening repulsive forces such as electrostatic repulsive forces between abrasive grains, and is therefore thought to be able to suppress aggregation of abrasive grains.

[0029] A 4-pyrone compound is a compound represented by the following general formula (1), and has a structure in which a hydroxy group is bonded to the carbon atom adjacent to the carbon atom of a carbonyl group. A "4-pyrone compound" is a heterocyclic compound having a γ-pyrone ring (6-membered ring) that has an oxy group and a carbonyl group, and the carbonyl group is located at the 4-position relative to the oxy group. In a 4-pyrone compound, a hydroxy group is bonded to the carbon atom adjacent to the carboxy group in this γ-pyrone ring, and the other carbon atoms may be substituted with a substituent other than a hydrogen atom.

[0030] [ka]

[0031] In the formula, X 11 , X 12 and X 13 are each independently a hydrogen atom or a monovalent substituent. Examples of the monovalent substituent include an aldehyde group, a hydroxy group, a carboxy group, a carboxylate group, a sulfonic acid group, a phosphate group, a bromine atom, a chlorine atom, an iodine atom, a fluorine atom, a nitro group, a hydrazine group, an alkyl group (e.g., an alkyl group having 1 to 8 carbon atoms), an aryl group (e.g., an aryl group having 6 to 12 carbon atoms), an alkenyl group (e.g., an alkenyl group having 1 to 8 carbon atoms), and the like. The alkyl group, the aryl group, and the alkenyl group may be substituted with OH, COOH, Br, Cl, I, NO2, or the like. X 11 , X 12 and X 13When the aryl group has a monovalent substituent as X, the substituent may be attached to the carbon atom adjacent to the oxy group, i.e., X 11 and X 12 may be a substituent. X 11 , X 12 and X 13 At least two of may be hydrogen atoms.

[0032] The 4-pyrone-based compound may contain at least one selected from the group consisting of 3-hydroxy-2-methyl-4-pyrone (also known as 3-hydroxy-2-methyl-4H-pyran-4-one, maltol), 5-hydroxy-2-(hydroxymethyl)-4-pyrone (also known as 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one, kojic acid), and 2-ethyl-3-hydroxy-4-pyrone (also known as 2-ethyl-3-hydroxy-4H-pyran-4-one), and may contain 3-hydroxy-2-methyl-4-pyrone, from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex parts of the patterned wafer and easily suppressing aggregation of abrasive grains. The 4-pyrone-based compound may be used alone or in combination of two or more.

[0033] The 4-pyrone compound may be water-soluble. By using a compound having high solubility in water, a desired amount of additive can be dissolved well in the polishing liquid, and the effect of improving the polishing rate and suppressing the aggregation of abrasive grains can be achieved at a higher level. The solubility of the 4-pyrone compound in 100 g of water at room temperature (25° C.) may be 0.001 g or more, 0.005 g or more, 0.01 g or more, or 0.05 g or more. There is no particular upper limit to the solubility.

[0034] The content of the 4-pyrone compound may be in the following range based on the total mass of the polishing liquid, from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex parts of the patterned wafer and from the viewpoint of easily achieving high-speed polishing of silicon oxide on the blanket wafer: The content of the 4-pyrone compound may be 0.001 mass% or more, 0.005 mass% or more, 0.01 mass% or more, 0.015 mass% or more, 0.02 mass% or more, 0.025 mass% or more, 0.03 mass% or more, 0.032 mass% or more, 0.034 mass% or more, 0.035 mass% or more, 0.04 mass% or more, 0.05 mass% or more, 0.08 mass% or more, 0.1 mass% or more, 0.13 mass% or more, 0.15 mass% or more, 0.18 mass% or more, or 0.2 mass% or more. The content of 4-pyrone compounds is 5% by mass or less, 3% by mass or less, 1% by mass or less, 0.8% by mass or less, 0.5% by mass or less, 0.3% by mass or less, 0.2% by mass or less, 0.18% by mass or less, 0.15 It may be 0.13% by mass or less, 0.1% by mass or less, 0.08% by mass or less, 0.05% by mass or less, 0.04% by mass or less, 0.035% by mass or less, or 0.034% by mass or less. From these viewpoints, the content of the 4-pyrone compound may be 0.001 to 5 mass%, 0.001 to 1 mass%, 0.001 to 0.3 mass%, 0.001 to 0.1 mass%, 0.001 to 0.05 mass%, 0.01 to 5 mass%, 0.01 to 1 mass%, 0.01 to 0.3 mass%, 0.01 to 0.1 mass%, 0.01 to 0.05 mass%, 0.02 to 5 mass%, 0.02 to 1 mass%, 0.02 to 0.3 mass%, 0.02 to 0.1 mass%, or 0.02 to 0.05 mass%.

[0035] The mass ratio A1 of the content of the 4-pyrone compound to the content of the abrasive grains (4-pyrone compound / abrasive grains) may be in the following range, from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex parts of the patterned wafer. The mass ratio A1 may be 0.01 or more, 0.03 or more, 0.5 or more, 0.08 or more, 0.1 or more, 0.12 or more, 0.13 or more, 0.15 or more, 0.18 or more, or 0.2 or more. The mass ratio A1 may be 1 or less, less than 1, 0.8 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, 0.18 or less, 0.15 or less, 0.13 or less, 0.12 or less, or 0.1 or less. From these viewpoints, the mass ratio A1 may be 0.01 to 1, 0.01 to 0.3, 0.01 to 0.15, 0.1 to 1, 0.1 to 0.3, 0.1 to 0.15, 0.12 to 1, 0.12 to 0.3, or 0.12 to 0.15.

[0036] [Component (A2): Picolinic acid] The additive for the polishing liquid according to the second embodiment contains picolinic acid as the component (A2). It is presumed that the use of the component (A2) enhances the interaction between the polishing liquid and silicon oxide, which tends to increase the removal rate.

[0037] The content of picolinic acid may be in the following range based on the total mass of the polishing liquid, from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex portion of the patterned wafer. The content of picolinic acid may be 0.001 mass% or more, 0.005 mass% or more, 0.01 mass% or more, 0.03 mass% or more, 0.05 mass% or more, 0.08 mass% or more, 0.1 mass% or more, 0.12 mass% or more, 0.15 mass% or more, 0.18 mass% or more, or 0.2 mass% or more. The content of picolinic acid may be 5 mass% or less, 3 mass% or less, 1 mass% or less, 0.8 mass% or less, 0.5 mass% or less, 0.4 mass% or less, 0.3 mass% or less, or 0.2 mass% or less. From these viewpoints, the content of picolinic acid may be 0.001 to 5 mass%, 0.001 to 1 mass%, 0.001 to 0.5 mass%, 0.001 to 0.3 mass%, 0.01 to 5 mass%, 0.01 to 1 mass%, 0.01 to 0.5 mass%, 0.01 to 0.3 mass%, 0.1 to 5 mass%, 0.1 to 1 mass%, 0.1 to 0.5 mass%, or 0.1 to 0.3 mass%.

[0038] The mass ratio A2 of the content of picolinic acid to the content of abrasive grains (picolinic acid / abrasive grains) may be in the following range, from the viewpoint of easily obtaining a high removal rate of silicon oxide on the convex portions of the patterned wafer. The mass ratio A2 may be 0.01 or more, 0.03 or more, 0.05 or more, 0.08 or more, 0.1 or more, 0.12 or more, 0.15 or more, 0.18 or more, or 0.2 or more. The mass ratio A2 may be 1 or less, less than 1, 0.8 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.25 or less, or 0.2 or less. From these viewpoints, the mass ratio A2 may be 0.01 to 1, 0.01 to 0.5, 0.01 to 0.3, 0.01 to 0.2, 0.05 to 1, 0.05 to 0.5, 0.05 to 0.3, 0.05 to 0.2, 0.1 to 1, 0.1 to 0.5, 0.1 to 0.3, or 0.1 to 0.2.

[0039] [Component (B): Nitrogen-containing hydroxyalkyl compound] The polishing liquid additive according to this embodiment contains, as component (B), a compound having two or more nitrogen atoms to which a hydroxyalkyl group is bonded (nitrogen-containing hydroxyalkyl compound). In component (B), a hydroxyalkyl group is directly bonded to a nitrogen atom, and a hydroxy group is directly bonded to the alkyl group directly bonded to the nitrogen atom. In component (B), an alkyl group having no substituent other than a hydroxy group can be used as the hydroxyalkyl group bonded to the nitrogen atom.

[0040] From the viewpoint of easily obtaining a high removal rate of silicon oxide on the convex portions of a patterned wafer, component (B) may contain a compound having a nitrogen atom to which two hydroxyalkyl groups are bonded, or may contain a compound having two or more nitrogen atoms to which two hydroxyalkyl groups are bonded.

[0041] From the viewpoint of easily obtaining a high polishing rate for silicon oxide on convex portions of a patterned wafer, the number of nitrogen atoms in one molecule of component (B) may be 2 to 5, 2 to 4, or 2 to 3. From the viewpoint of easily obtaining a high polishing rate for silicon oxide on convex portions of a patterned wafer, the number of hydroxyl groups in one molecule of component (B) may be 2 to 6, 2 to 5, 2 to 4, 3 to 6, 3 to 5, 3 to 4, 4 to 6, or 4 to 5.

[0042] From the viewpoint of easily obtaining a high removal rate of silicon oxide on convex portions of a patterned wafer, the component (B) may have, as a hydroxyalkyl group bonded to a nitrogen atom, a hydroxyalkyl group having 1 to 4, 2 to 4, 3 to 4, 1 to 3, 2 to 3 or 1 to 2 carbon atoms. From the viewpoint of easily obtaining a high removal rate of silicon oxide on convex portions of a patterned wafer, the component (B) may have, as a hydroxyalkyl group bonded to a nitrogen atom, a hydroxyalkyl group having 1 to 3 or 1 to 2 hydroxy groups.

[0043] From the viewpoint of easily obtaining a high removal rate of silicon oxide on the convex portions of a patterned wafer, the component (B) may have an alkylene group between the two nitrogen atoms to which the hydroxyalkyl groups are bonded, and the alkylene group may have 1 to 4, 2 to 4, 1 to 3, 2 to 3, or 1 to 2 carbon atoms.

[0044] From the viewpoint of easily achieving a high removal rate of silicon oxide on the convex portions of a patterned wafer, the component (B) may contain a compound represented by the following general formula (I).

[0045] [ka] [In the formula, n is an integer of 1 or more, and R 11 , R 12 , R 13 and R 14 each independently represents a hydrogen atom or an organic group; R 11 and R 12 one or both of R 13 and R 14 One or both of the groups are hydroxyalkyl groups.

[0046] n may be in the range described above as the number of carbon atoms in the alkylene group between the two nitrogen atoms to which the hydroxyalkyl groups are bonded. The organic group may be a substituted or unsubstituted alkyl group, a hydroxyalkyl group, or a group having a nitrogen atom to which a hydroxyalkyl group is bonded. Examples of the substituent of the alkyl group include a hydroxy group, a carboxy group, an amino group, a sulfo group, and a nitro group. R 11 , R 12 , R 13 or R 14 When is a hydroxyalkyl group, the number of carbon atoms in the hydroxyalkyl group may be within the range described above for the number of carbon atoms in a hydroxyalkyl group bonded to a nitrogen atom.

[0047] Examples of component (B) include ethylenedinitrilotetraethanol (THEED: 2,2',2'',2'''-ethylenedinitrilotetraethanol (also known as N,N,N',N'-Tetrakis(2-hydroxyethyl)ethylenediamine), etc.), ethylenedinitrilotetrapropanol (EDTP: 1,1',1'',1'''-ethylenedinitrilotetra-2-propanol (also known as N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine), etc.), and N,N,N',N'',N''-Pentakis(2-hydroxypropyl)diethylenetriamine. From the viewpoint of easily achieving a high polishing rate of silicon oxide on the convex portions of a patterned wafer and from the viewpoint of easily achieving high-speed polishing of silicon oxide on a blanket wafer, component (B) may contain at least one selected from the group consisting of ethylene dinitrilotetraethanol and ethylene dinitrilotetrapropanol, may contain ethylene dinitrilotetraethanol, or may contain ethylene dinitrilotetrapropanol. From the viewpoint of easily achieving a high polishing rate of silicon oxide on the convex portions of a patterned wafer, component (B) may contain a compound that does not have a carboxy group.

[0048] From the viewpoint of easily obtaining a high removal rate of silicon oxide on the convex portions of a patterned wafer, the molecular weight of the component (B) may be within the following ranges: The molecular weight of the component (B) may be 50 or more, 60 or more, 70 or more, 80 or more, 85 or more, 90 or more, 100 or more, 110 or more, 120 or more, 123 or more, 125 or more, 130 or more, 140 or more, 148 or more, 150 or more, 160 or more, 170 or more, 180 or more, 200 or more, 210 or more, 230 or more, 250 or more, more than 250, or 280 or more. The molecular weight of the component (B) may be 1000 or less, less than 1000, 900 or less, 800 or less, 700 or less, 600 or less, 500 or less, 400 or less, 350 or less, 300 or less, 280 or less, 250 or less, less than 250, or 240 or less. From these viewpoints, the molecular weight of the (B) component may be 50-1000, 50-500, 50-300, 50-250, 200-1000, 200-500, 200-300, 200-250, 250-1000, 250-500, or 250-300.

[0049] In the polishing liquid according to the first embodiment, the content B1 of the component (B), the content of ethylene dinitrilotetraethanol, or the content of ethylene dinitrilotetrapropanol may be in the following range based on the total mass of the polishing liquid, from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex portions of the patterned wafer: The content B1 may be 0.001 mass% or more, 0.005 mass% or more, 0.01 mass% or more, 0.015 mass% or more, 0.02 mass% or more, 0.025 mass% or more, 0.03 mass% or more, 0.035 mass% or more, 0.04 mass% or more, 0.045 mass% or more, or 0.05 mass% or more. Content B1 is 5% by mass or less, 3% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, 0.15% by mass or less, 0.1% by mass or less, 0.08% by mass or less , 0.06% by mass or less, 0.05% by mass or less, 0.045% by mass or less, 0.04% by mass or less, 0.035% by mass or less, 0.03% by mass or less, 0.025% by mass or less, or 0.02% by mass or less. From these viewpoints, the content B1 may be 0.001 to 5 mass%, 0.001 to 1 mass%, 0.001 to 0.1 mass%, 0.001 to 0.05 mass%, 0.01 to 5 mass%, 0.01 to 1 mass%, 0.01 to 0.1 mass%, 0.01 to 0.05 mass%, 0.02 to 5 mass%, 0.02 to 1 mass%, 0.02 to 0.1 mass%, or 0.02 to 0.05 mass%.

[0050] In the polishing liquid according to the second embodiment, the content B2 of the component (B), the content of ethylenedinitrilotetraethanol, or the content of ethylenedinitrilotetrapropanol may be in the following range based on the total mass of the polishing liquid, from the viewpoint of easily obtaining a high polishing rate for silicon oxide on convex portions of a patterned wafer, and from the viewpoint of easily achieving high-speed polishing of silicon oxide on a blanket wafer. Content B2 is 0.001 mass% or more, 0.005 mass% or more, 0.01 mass% or more, 0.015 mass% or more, 0.02 mass% or more, 0.025 mass% or more, 0.03 mass% or more, 0.035 mass% or more, 0.04 mass% or more, 0. It may be 045% by mass or more, 0.05% by mass or more, 0.06% by mass or more, 0.08% by mass or more, 0.1% by mass or more, 0.12% by mass or more, 0.13% by mass or more, 0.15% by mass or more, 0.2% by mass or more, or 0.22% by mass or more. Content B2 is 5% by mass or less, 3% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, 0.22% by mass or less, 0.2% by mass or less, 0.15% by mass or less, 0.13% by mass or less, 0.12% by mass or less, 0.1% by mass or less, 0.08 quality % or less, 0.06% by mass or less, 0.05% by mass or less, 0.045% by mass or less, 0.04% by mass or less, 0.035% by mass or less, 0.03% by mass or less, 0.025% by mass or less, 0.02% by mass or less, 0.015% by mass or less, or 0.01% by mass or less. From these viewpoints, the content B2 may be 0.001 to 5 mass%, 0.001 to 1 mass%, 0.001 to 0.3 mass%, 0.001 to 0.05 mass%, 0.01 to 5 mass%, 0.01 to 1 mass%, 0.01 to 0.3 mass%, 0.01 to 0.05 mass%, 0.02 to 5 mass%, 0.02 to 1 mass%, 0.02 to 0.3 mass%, or 0.02 to 0.05 mass%.

[0051] In the polishing liquid according to the first embodiment, the mass ratio B11 of the content of the component (B) to the content of the abrasive grains (component (B) / abrasive grains), the mass ratio of the content of the ethylenedinitrilotetraethanol to the content of the abrasive grains (ethylenedinitrilotetraethanol / abrasive grains), or the mass ratio of the content of the ethylenedinitrilotetrapropanol to the content of the abrasive grains (ethylenedinitrilotetrapropanol / abrasive grains) may be in the following ranges from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex portions of the patterned wafer. The mass ratio B11 may be 0.001 or more, 0.005 or more, 0.01 or more, 0.02 or more, 0.03 or more, 0.05 or more, 0.08 or more, 0.1 or more, 0.12 or more, 0.15 or more, 0.18 or more, or 0.2 or more. The mass ratio B11 may be 10 or less, 5 or less, 2 or less, 1 or less, less than 1, 0.5 or less, 0.3 or less, 0.2 or less, 0.18 or less, 0.15 or less, 0.12 or less, 0.1 or less, 0.08 or less, 0.05 or less, 0.03 or less, or 0.02 or less. From these viewpoints, the mass ratio B11 may be 0.001 to 10, 0.001 to 1, 0.001 to 0.3, 0.001 to 0.1, 0.01 to 10, 0.01 to 1, 0.01 to 0.3, 0.01 to 0.1, 0.02 to 10, 0.02 to 1, 0.02 to 0.3, or 0.02 to 0.1.

[0052] In the polishing liquid according to the second embodiment, the mass ratio B21 of the content of the component (B) to the content of the abrasive grains (component (B) / abrasive grains), the mass ratio of the content of the ethylene dinitrilotetraethanol to the content of the abrasive grains (ethylene dinitrilotetraethanol / abrasive grains), or the mass ratio of the content of the ethylene dinitrilotetrapropanol to the content of the abrasive grains (ethylene dinitrilotetrapropanol / abrasive grains) may be in the following ranges from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex portions of the patterned wafer. The mass ratio B21 may be 0.001 or more, 0.005 or more, 0.01 or more, 0.02 or more, 0.03 or more, 0.04 or more, 0.05 or more, 0.06 or more, 0.08 or more, 0.1 or more, 0.13 or more, 0.15 or more, 0.2 or more, or 0.22 or more. The mass ratio B21 may be 10 or less, 5 or less, 2 or less, 1 or less, less than 1, 0.5 or less, 0.3 or less, 0.25 or less, 0.22 or less, 0.2 or less, 0.15 or less, 0.13 or less, 0.1 or less, 0.08 or less, 0.06 or less, 0.05 or less, 0.04 or less, 0.03 or less, 0.02 or less, or 0.01 or less. From these viewpoints, the mass ratio B21 may be 0.001 to 10, 0.001 to 1, 0.001 to 0.3, 0.001 to 0.2, 0.01 to 10, 0.01 to 1, 0.01 to 0.3, 0.01 to 0.2, 0.03 to 10, 0.03 to 1, 0.03 to 0.3, or 0.03 to 0.2.

[0053] In the polishing liquid according to the first embodiment, the mass ratio B12 of the content of the component (B) to the content of the component (A1) (component (B) / component (A1)), the mass ratio of the content of the ethylenedinitrilotetraethanol to the content of the component (A1) (ethylenedinitrilotetraethanol / component (A1)), or the mass ratio of the content of the ethylenedinitrilotetrapropanol to the content of the component (A1) (ethylenedinitrilotetrapropanol / component (A1)) may be in the following ranges from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex portions of the patterned wafer. The mass ratio B12 may be 0.01 or more, 0.05 or more, 0.1 or more, 0.15 or more, 0.2 or more, 0.3 or more, 0.5 or more, 0.6 or more, 0.8 or more, 0.85 or more, 0.9 or more, 1 or more, more than 1, 1.1 or more, 1.2 or more, or 1.4 or more. The mass ratio B12 may be 10 or less, 8 or less, 5 or less, 2 or less, 1.5 or less, 1.4 or less, 1.2 or less, 1.1 or less, 1 or less, less than 1, 0.9 or less, 0.85 or less, 0.8 or less, 0.6 or less, 0.5 or less, 0.3 or less, 0.2 or less, 0.15 or less, or 0.1 or less. From these viewpoints, the mass ratio B12 may be 0.01 to 10, 0.01 to 2, 0.01 to 1, 0.01 to 0.5, 0.05 to 10, 0.05 to 2, 0.05 to 1, 0.05 to 0.5, 0.15 to 10, 0.15 to 2, 0.15 to 1, or 0.15 to 0.5.

[0054] In the polishing liquid according to the second embodiment, the mass ratio B22 of the content of the component (B) to the content of the component (A2) (component (B) / component (A2)), the mass ratio of the content of ethylene dinitrilotetraethanol to the content of the component (A2) (ethylene dinitrilotetraethanol / component (A2)), or the mass ratio of the content of ethylene dinitrilotetrapropanol to the content of the component (A2) (ethylene dinitrilotetrapropanol / component (A2)) may be in the following ranges from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex portions of the patterned wafer. The mass ratio B22 may be 0.01 or more, 0.05 or more, 0.1 or more, 0.15 or more, 0.2 or more, 0.25 or more, 0.3 or more, 0.5 or more, 0.6 or more, 0.65 or more, 0.7 or more, 0.8 or more, 1 or more, more than 1, or 1.1 or more. The mass ratio B22 may be 10 or less, 8 or less, 5 or less, 2 or less, 1.5 or less, 1.2 or less, 1.1 or less, 1 or less, less than 1, 0.8 or less, 0.7 or less, 0.65 or less, 0.6 or less, 0.5 or less, 0.3 or less, 0.25 or less, 0.2 or less, 0.15 or less, 0.1 or less, or 0.05 or less. From these viewpoints, the mass ratio B22 may be 0.01 to 10, 0.01 to 2, 0.01 to 1, 0.01 to 0.8, 0.1 to 10, 0.1 to 2, 0.1 to 1, 0.1 to 0.8, 0.2 to 10, 0.2 to 2, 0.2 to 1, or 0.2 to 0.8.

[0055] [Saturated monocarboxylic acids] The additive of the polishing liquid according to the present embodiment may contain saturated monocarboxylic acid. By using saturated monocarboxylic acid, it is easy to obtain a sufficiently small polishing rate of silicon nitride that can be used as a stopper material, and it is also advantageous in that it not only improves the dispersibility of cerium-based particles, but also improves the in-plane uniformity, which is an index of the variation of the polishing rate within the polished surface, without decreasing the polishing rate of a patterned wafer (e.g., a semiconductor substrate having a concave-convex pattern).

[0056] Examples of the saturated monocarboxylic acid include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, hydroangelic acid, caproic acid, 2-methylpentanoic acid, 4-methylpentanoic acid, 2,3-dimethylbutanoic acid, 2-ethylbutanoic acid, 2,2-dimethylbutanoic acid, and 3,3-dimethylbutanoic acid. The saturated monocarboxylic acid may include an aliphatic carboxylic acid from the viewpoint of easily obtaining the above-mentioned effect of adding the saturated monocarboxylic acid. The saturated monocarboxylic acid may include a saturated monocarboxylic acid having 2 to 6 carbon atoms, and may include at least one selected from the group consisting of acetic acid and propionic acid, from the viewpoint of effectively obtaining the effect of suppressing the polishing rate of silicon nitride and from the viewpoint of more favorably obtaining the effect of improving the in-plane uniformity.

[0057] The content of the saturated monocarboxylic acid (for example, saturated monocarboxylic acid having 2 to 6 carbon atoms) may be within the following range based on the total mass of the polishing liquid, from the viewpoint of effectively obtaining the effect of improving the in-plane uniformity, the effect of improving the polishing rate of the patterned wafer, and the effect of suppressing the polishing rate of silicon nitride. The content of the saturated monocarboxylic acid may be 0.0001 mass% or more, 0.0005 mass% or more, 0.001 mass% or more, 0.002 mass% or more, 0.005 mass% or more, 0.01 mass% or more, 0.02 mass% or more, 0.03 mass% or more, 0.04 mass% or more, or 0.045 mass% or more. The content of the saturated monocarboxylic acid may be 5 mass% or less, 3 mass% or less, 1 mass% or less, 0.5 mass% or less, 0.4 mass% or less, 0.3 mass% or less, 0.2 mass% or less, 0.1 mass% or less, 0.05 mass% or less, or 0.045 mass% or less. From these viewpoints, the content of the saturated monocarboxylic acid may be 0.0001 to 5 mass%, 0.0001 to 1 mass%, 0.0001 to 0.1 mass%, 0.0001 to 0.05 mass%, 0.01 to 5 mass%, 0.01 to 1 mass%, 0.01 to 0.1 mass%, 0.01 to 0.05 mass%, 0.03 to 5 mass%, 0.03 to 1 mass%, 0.03 to 0.1 mass%, or 0.03 to 0.05 mass%. The content of the saturated monocarboxylic acid may be 0.04 mass% or less, 0.03 mass% or less, 0.02 mass% or less, 0.01 mass% or less, 0.005 mass% or less, 0.002 mass% or less, 0.001 mass% or less, 0.0005 mass% or less, or substantially 0 mass%.

[0058] [Other additives] The additive of the polishing liquid according to this embodiment may further contain other components (components other than those mentioned above) according to the desired properties. Such components include nonionic polymers, cationic compounds, pH adjusters described below, polar solvents such as ethanol and acetone, and cyclic monocarboxylic acids.

[0059] The polishing liquid according to this embodiment may contain a compound a having a molecular weight of 100,000 or less and having 4 or more hydroxyl groups, or may not contain compound a. The polishing liquid according to this embodiment may contain a compound b having 4 or more amino groups, or may not contain compound b. The content of compound b may be 0.001 mass% or less, less than 0.001 mass%, 0.0001 mass% or less, 0.00001 mass% or less, or substantially 0 mass% based on the total mass of the polishing liquid. The mass ratio of the content of compound a to the content of compound b (compound a / compound b) may be 0.10 or less, or less than 0.10.

[0060] (water) The water is not particularly limited, but may include at least one selected from the group consisting of deionized water, ion-exchanged water, and ultrapure water.

[0061] (pH) The pH of the polishing liquid according to the present embodiment may be in the following ranges: From the viewpoint of easily suppressing aggregation of abrasive grains, easily obtaining a high polishing rate of silicon oxide on the convex portion of the patterned wafer, easily suppressing the polishing rate of silicon nitride usable as a stopper material, and easily obtaining the effect of adding the additive, the pH may be 12.0 or less, 11.0 or less, 10.5 or less, less than 10.5, 10.0 or less, less than 10.0, 9.5 or less, 9.0 or less, less than 9.0, 8.5 or less, 8.0 or less, less than 8.0, 7.5 or less, 7.3 or less, 7.0 or less, less than 7.0, 6.5 or less, 6.0 or less, less than 6.0, 5.6 or less, 5.5 or less, less than 5.5, 5.1 or less, 5.0 or less, 4.8 or less, 4.7 or less, 4.6 or less, 4.5 or less, 4.4 or less, 4.3 or less, 4.2 or less, 4.1 or less, or 4.0 or less. The pH may be 3.0 or more, 3.5 or more, 3.7 or more, 3.8 or more, 4.0 or more, more than 4.0, 4.1 or more, 4.2 or more, 4.3 or more, 4.4 or more, 4.5 or more, 4.6 or more, 4.7 or more, 4.8 or more, 5.0 or more, 5.1 or more, 5.5 or more, more than 5.5, 5.6 or more, 6.0 or more, more than 6.0, 6.5 or more, 7.0 or more, more than 7.0, or 7.3 or more, from the viewpoint of easily preventing the silicon oxide to be polished from having a zeta potential with a large absolute value on the positive side like the cerium-based particles (e.g., cerium oxide particles) and easily obtaining a high polishing rate for silicon oxide on the convex portions of the patterned wafer. From these viewpoints, the pH may be 3.0 to 12.0, 3.0 or more and less than 9.0, 3.0 to 8.0, 3.0 to 5.5, 3.0 to 5.0, 3.5 to 12.0, 3.5 or more and less than 9.0, 3.5 to 8.0, 3.5 to 5.5, 3.5 to 5.0, 4.0 to 12.0, 4.0 or more and less than 9.0, 4.0 to 8.0, 4.0 to 5.5, or 4.0 to 5.0. The pH can be measured by the method described in the Examples.

[0062] Since the pH may vary depending on the type of compound used as an additive, a pH adjuster may be used to adjust the pH to the above range. There is no particular limitation on the pH adjuster, and examples thereof include acids such as nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, and boric acid; and bases such as sodium hydroxide, ammonia (e.g., aqueous ammonia), potassium hydroxide, and calcium hydroxide. The above-mentioned additives such as saturated monocarboxylic acids may be used to adjust the pH. From the viewpoint of improving productivity, the polishing liquid may be prepared without using a pH adjuster, and this polishing liquid may be directly applied to CMP.

[0063] <How to prepare and use the polishing solution> The polishing liquid according to this embodiment can be classified into (a) a normal type, (b) a concentrated type, and (c) a multiple liquid type (e.g., a two-liquid type, a polishing liquid set for CMP), and the preparation method and method of use differ depending on the type. (a) The normal type is a polishing liquid that can be used as is during polishing without pretreatment such as dilution. (b) The concentrated type is a polishing liquid in which the components are concentrated compared to the normal type (a) in consideration of convenience in storage or transportation. (c) The multiple liquid type is a polishing liquid in which the components are separated into multiple liquids (e.g., a first liquid containing certain components and a second liquid containing other components) during storage or transportation, and these liquids are mixed when used.

[0064] (a) The normal type can be obtained by dissolving or dispersing abrasive grains and additives in water, which is the main dispersion medium. For example, to prepare 1000 g of polishing liquid with 0.5 parts by mass of abrasive grains and 0.1 parts by mass of additives per 100 parts by mass of polishing liquid, the amounts of the abrasive grains and additives are adjusted to 5 g and 1 g, respectively, relative to the total amount of the polishing liquid.

[0065] The preparation of the polishing liquid can be carried out using, for example, a stirrer, a homogenizer, an ultrasonic disperser, a wet ball mill, etc. In addition, a process of micronizing the abrasive grains may be carried out in the process of preparing the polishing liquid so that the average grain size of the abrasive grains falls within a desired range. The micronization process of the abrasive grains can be carried out by a sedimentation classification method or a method using a high-pressure homogenizer. The sedimentation classification method is a method that includes a process of forcibly sedimenting a slurry containing the abrasive grains using a centrifuge and a process of extracting only the supernatant liquid. On the other hand, the method using a high-pressure homogenizer is a method in which the abrasive grains in the dispersion medium are collided with each other at high pressure.

[0066] (b) Concentrated type is diluted with water immediately before use so that the content of the ingredients is the desired content. After dilution, stirring may be performed for any length of time until the liquid characteristics (pH, abrasive grain size, etc.) and polishing characteristics (polishing speed of silicon oxide, polishing selectivity between silicon oxide and silicon nitride, etc.) are similar to those of (a) normal type. With such (b) concentrated type, the volume becomes smaller depending on the degree of concentration, so storage and transportation costs can be reduced.

[0067] The concentration ratio may be 1.5 times or more, 2 times or more, 3 times or more, or 5 times or more. When the concentration ratio is 1.5 times or more, advantages in terms of storage and transportation tend to be obtained more easily than when the concentration ratio is less than 1.5 times. The concentration ratio may be 40 times or less, 20 times or less, or 15 times or less. When the concentration ratio is 40 times or less, aggregation of the abrasive grains tends to be suppressed more easily than when the concentration ratio is more than 40 times.

[0068] The (c) multiple liquid type has an advantage over the (b) concentrated type in that each liquid (first liquid, second liquid, etc.) is appropriately separated to avoid aggregation of abrasive grains. Here, the components contained in each liquid are arbitrary. The (c) multiple liquid type (CMP polishing liquid set) is a polishing liquid set for obtaining a polishing liquid by mixing a first liquid (slurry) and a second liquid (additive liquid). In the (c) multiple liquid type, the components of the CMP polishing liquid are stored separately as a first liquid and a second liquid, the first liquid contains abrasive grains and water, and the second liquid contains at least one type of additive and water. In a first embodiment of the (c) multiple liquid type, the first liquid contains abrasive grains and water, and the second liquid contains at least one type selected from the group consisting of the (A1) component and the (A2) component, the (B) component, and water. (c) In the second embodiment of the multiple liquid type, the first liquid contains abrasive grains, at least one selected from the group consisting of the (A1) component and the (A2) component, and water, and the second liquid contains the (B) component and water. (c) In the third embodiment of the multiple liquid type, the first liquid contains abrasive grains, one of the (A1) component and the (A2) component, the (B) component, and water, and the second liquid contains the other of the (A1) component and the (A2) component, and water. (c) In the fourth embodiment of the multiple liquid type, the first liquid contains abrasive grains, the (B) component, and water, and the second liquid contains at least one selected from the group consisting of the (A1) component and the (A2) component, and water. The first liquid and the second liquid may contain other components that are mixed as necessary. In this case, in order to improve the dispersibility of the abrasive grains in the first liquid, any acid or alkali may be added to the first liquid to adjust the pH.

[0069] (c) A multi-liquid type polishing liquid is useful for a combination of components that, when mixed, tend to have their polishing properties deteriorated in a relatively short time due to agglomeration of abrasive grains, etc. From the viewpoint of reducing storage and transportation costs, at least one of the liquids (first liquid, second liquid, etc.) may be a concentrated type. In this case, when using the polishing liquid, each liquid can be mixed with water. The concentration rate and pH of each liquid are arbitrary, and it is sufficient that the final mixture has the same liquid properties and polishing properties as the (a) normal type polishing liquid.

[0070] <Polishing method> The polishing method according to this embodiment includes a polishing step of polishing a surface to be polished using the polishing liquid according to this embodiment. The polishing liquid used in the polishing step may be a polishing liquid obtained by mixing the first liquid and the second liquid in the above-mentioned polishing liquid set. That is, the polishing method according to this embodiment may include a polishing step of polishing a surface to be polished using a polishing liquid obtained by mixing the first liquid and the second liquid in the above-mentioned polishing liquid set.

[0071] The polishing method according to this embodiment uses a polishing solution in which the content of each component, pH, etc. have been adjusted, and can planarize a substrate having a silicon oxide film on its surface by CMP technology. The polishing method according to this embodiment is suitable for polishing that requires high speed, high flatness, and few polishing scratches, such as polishing of an ILD film, and is suitable for polishing a large number of ILD films in a short period of time.

[0072] The polishing process may be a process of supplying the polishing liquid according to this embodiment between a substrate and a polishing member (a polishing member, such as a polishing pad), and polishing the substrate with the polishing member. The polishing method according to this embodiment is suitable for polishing a substrate having a silicon oxide film on its surface. Therefore, the surface to be polished may contain silicon oxide, and the polishing process may be a process of supplying the polishing liquid according to this embodiment between the silicon oxide film on a substrate having a silicon oxide film on its surface and the polishing member, and polishing the silicon oxide film with the polishing member.

[0073] The polishing method according to this embodiment is suitable for polishing a substrate having a silicon oxide film on its surface in the process of manufacturing a device. Examples of the device include discrete semiconductors such as diodes, transistors, compound semiconductors, thermistors, varistors, and thyristors; memory elements such as DRAM (dynamic random access memory), SRAM (static random access memory), EPROM (erasable programmable read-only memory), mask ROM (mask read-only memory), EEPROM (electrically erasable programmable read-only memory), and flash memory; logic circuit elements such as microprocessors, DSPs, and ASICs; integrated circuit elements such as compound semiconductors represented by MMICs (monolithic microwave integrated circuits); hybrid integrated circuits (hybrid ICs); light-emitting diodes; and photoelectric conversion elements such as charge-coupled devices.

[0074] According to one aspect of the polishing liquid of the present embodiment, a high polishing rate can be achieved without being largely dependent on the uneven shape of the polished surface. Therefore, the polishing method using the polishing liquid can be applied to substrates for which it is difficult to achieve a high polishing rate using conventional polishing liquids.

[0075] The polishing method according to this embodiment is suitable for planarizing a surface to be polished that has steps (unevenness) on the surface. An example of a substrate having such a surface to be polished is a semiconductor device for logic. The polishing method according to this embodiment is also suitable for polishing a surface that includes a portion in which the concave or convex portions are T-shaped or lattice-shaped when viewed from above. For example, the polishing method according to this embodiment can polish a silicon oxide film provided on the surface of a semiconductor device having memory cells (DRAM, flash memory, etc.) at a high speed. These are cases where it was difficult to achieve a high polishing rate using a conventional method using a polishing liquid for CMP, and this shows that one aspect of the polishing liquid according to this embodiment can achieve a high polishing rate without being largely dependent on the uneven shape of the surface to be polished.

[0076] The substrate is not limited to a substrate having only a silicon oxide film on its surface, but may be a substrate having, on its surface, a silicon nitride film, a polycrystalline silicon film, etc., in addition to a silicon oxide film. The substrate may be a substrate having, on a wiring board having predetermined wiring, an inorganic insulating film such as silicon oxide, glass, silicon nitride, etc.; a film mainly containing polysilicon, Al, Cu, Ti, TiN, W, Ta, TaN, etc.

[0077] Hereinafter, as an example of a process including the polishing method according to this embodiment, a process of forming an ILD film (interlayer dielectric film) structure by CMP will be described. Fig. 1 is a schematic cross-sectional view showing the process of polishing an ILD film, and shows the process of forming an ILD film between wirings. Fig. 1(a) is a schematic cross-sectional view showing a substrate before polishing. Fig. 1(b) is a schematic cross-sectional view showing the substrate after polishing.

[0078] 1(a), in a base 100 before polishing, a wiring 20 is formed on a lower substrate (not shown) having a predetermined lower wiring (not shown) via an ILD film 10, and a silicon oxide film 30 is formed so as to cover this wiring 20. Since the silicon oxide film 30 is formed on the ILD film 10 on which the wiring 20 is formed, the portion above the wiring 20 is higher than the other portions, resulting in a step D on the surface of the silicon oxide film 30. The wiring 20 is connected to the lower wiring, etc. by a contact plug 40 formed so as to penetrate the ILD film 10.

[0079] In the process of forming the ILD film structure, in order to eliminate the step D, unnecessary portions that protrude partially on the surface of the silicon oxide film 30 are preferentially removed by CMP. To polish the silicon oxide film 30, the substrate 100 is placed on a polishing member so that the surface of the silicon oxide film 30 and the polishing member come into contact with each other, and the surface of the silicon oxide film 30 is polished by the polishing member. More specifically, the surface to be polished (front surface) of the silicon oxide film 30 is pressed against the polishing member of the polishing table, and the silicon oxide film 30 is polished by moving the surface to be polished and the polishing member relatively while supplying a polishing liquid between them. This eliminates the step D, and finally, as shown in FIG. 1(b), the height of the wiring 20 part on the surface of the silicon oxide film 30 becomes almost the same as the height of the other part, and a substrate 100a having a silicon oxide film 30 (ILD film) with a flat surface is obtained.

[0080] The polishing device used for polishing may be, for example, a device equipped with a holder for holding a substrate, a polishing platen on which a polishing pad is attached, and a means for supplying a polishing liquid onto the polishing pad. Examples of the polishing device include polishing devices manufactured by Ebara Corporation (model numbers: EPO-111, EPO-222, F-REX200, and F-REX300), and polishing devices manufactured by Applied Materials (product names: Mirra3400 and Reflexion). There are no particular limitations on the material constituting the polishing pad, and for example, general nonwoven fabric, polyurethane foam, porous fluororesin, etc. may be used. In addition, the polishing pad may be grooved so that the polishing liquid can be collected.

[0081] There are no particular limitations on the polishing conditions, but the rotation speed of the polishing platen is set to 200 min -1The pressure (processing load) applied to the substrate may be 100 kPa or less from the viewpoint of easily suppressing polishing scratches on the surface to be polished. During polishing, a polishing liquid may be continuously supplied to the polishing pad by a pump or the like. There is no limit to the amount of supply, but the surface of the polishing pad may be constantly covered with the polishing liquid. After polishing is completed, the substrate may be thoroughly washed in running water, and then the substrate may be dried after removing water droplets adhering to the substrate using a spin dryer or the like.

[0082] By polishing in the manner described above, surface irregularities can be eliminated, and a smooth surface can be obtained over the entire surface of the substrate. Furthermore, by repeating the steps of forming a film and polishing this film a predetermined number of times, a structure having a desired number of layers can be manufactured.

[0083] The substrate (structure) thus obtained can be used as various electronic components. Specific examples of electronic components include semiconductor elements, optical glasses such as photomasks, lenses, and prisms, inorganic conductive films such as ITO, optical integrated circuits, optical switching elements, and optical waveguides made of glass and crystalline materials, end faces of optical fibers, optical single crystals such as scintillators, solid-state laser single crystals, sapphire substrates for blue laser LEDs, semiconductor single crystals such as SiC, GaP, and GaAs, glass substrates for magnetic disks, and magnetic heads.

[0084] <Manufacturing method etc.> The component manufacturing method according to the present embodiment includes a component manufacturing step of obtaining a component using a base (a member to be polished) polished by the polishing method according to the present embodiment. The component according to the present embodiment is a component obtained by the component manufacturing method according to the present embodiment. The component according to the present embodiment is not particularly limited, and may be an electronic component (e.g., a semiconductor component such as a semiconductor package), a wafer (e.g., a semiconductor wafer), or a chip (e.g., a semiconductor chip). As one aspect of the component manufacturing method according to the present embodiment, in the electronic component manufacturing method according to the present embodiment, an electronic component is obtained using a base polished by the polishing method according to the present embodiment. As one aspect of the component manufacturing method according to the present embodiment, in the semiconductor component manufacturing method according to the present embodiment, a semiconductor component (e.g., a semiconductor package) is obtained using a base polished by the polishing method according to the present embodiment. The component manufacturing method according to the present embodiment may include a polishing step of polishing a base by the polishing method according to the present embodiment before the component manufacturing step.

[0085] The component manufacturing method according to the present embodiment may include, as one aspect of the component manufacturing process, a singulation process for singulating a base (a polished member) polished by the polishing method according to the present embodiment. The singulation process may be, for example, a process for dicing a wafer (e.g., a semiconductor wafer) polished by the polishing method according to the present embodiment to obtain chips (e.g., semiconductor chips). As one aspect of the component manufacturing method according to the present embodiment, the electronic component manufacturing method according to the present embodiment may include a process for singulating a base polished by the polishing method according to the present embodiment to obtain electronic components (e.g., semiconductor components). As one aspect of the component manufacturing method according to the present embodiment, the semiconductor component manufacturing method according to the present embodiment may include a process for singulating a base polished by the polishing method according to the present embodiment to obtain semiconductor components (e.g., semiconductor packages).

[0086] The manufacturing method of the component according to the present embodiment may include, as one aspect of the component manufacturing process, a connection process for connecting (e.g., electrically connecting) the base (polished member) polished by the polishing method according to the present embodiment to another connected body. The connected body to be connected to the base polished by the polishing method according to the present embodiment is not particularly limited, and may be the base polished by the polishing method according to the present embodiment, or may be a connected body different from the base polished by the polishing method according to the present embodiment. In the connection process, the base and the connected body may be directly connected (connected in a state where the base and the connected body are in contact with each other), or the base and the connected body may be connected via another member (conductive member, etc.). The connection process may be performed before the singulation process, after the singulation process, or before or after the singulation process.

[0087] The connecting step may be a step of connecting the polished surface of the base polished by the polishing method according to the present embodiment to the connected body, or may be a step of connecting the connecting surface of the base polished by the polishing method according to the present embodiment to the connecting surface of the connected body. The connecting surface of the base may be the polished surface polished by the polishing method according to the present embodiment. The connecting step can obtain a connected body including the base and the connected body. In the connecting step, if the connecting surface of the base has a metal part, the connected body may be brought into contact with the metal part. In the connecting step, if the connecting surface of the base has a metal part and the connecting surface of the connected body has a metal part, the metal parts may be brought into contact with each other. The metal part may contain copper.

[0088] The device according to this embodiment (for example, an electronic device such as a semiconductor device) comprises at least one selected from the group consisting of a substrate polished by the polishing method according to this embodiment and a part according to this embodiment. EXAMPLES

[0089] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0090] <Preparation of cerium oxide powder> 40 kg of cerium carbonate hydrate was divided into 10 alumina containers and each was calcined in air at 830 °C for 2 hours to obtain a total of 20 kg of a yellowish-white powder. This powder was identified by X-ray diffraction, and it was confirmed that the powder contained polycrystalline cerium oxide. When the particle size of the powder obtained by calcination was observed by SEM, it was in the range of 20 - 100 μm. Next, 20 kg of cerium oxide powder was dry-ground using a jet mill to obtain cerium oxide powder A (the powder that gives abrasive grain A described later). The specific surface area of the cerium oxide powder A after grinding was 9.4 m 2 / g. The measurement of the specific surface area was carried out by the BET method.

[0091] <Preparation of slurry> 15.0 kg of the cerium oxide powder obtained above and 84.5 kg of deionized water were placed in a container and mixed. Next, 0.5 kg of 1 M (mol / L, approximately 6 mass%) acetic acid was added, and then the mixture was stirred for 10 minutes to obtain a cerium oxide mixed solution. This cerium oxide mixed solution was fed into another container over 30 minutes. During that time, ultrasonic irradiation was performed on the cerium oxide mixed solution at an ultrasonic frequency of 400 kHz in the pipe through which the solution was fed.

[0092] The cerium oxide mixed solution that had been fed after ultrasonic irradiation was placed in 4 polyethylene containers of 1000 mL, 800 g ± 8 g each. Centrifugation was performed on the cerium oxide mixed solution in each container for 20 minutes under the condition that the centrifugal force applied to the outer periphery was 500 G. After centrifugation, the supernatant fraction of the container was collected to obtain a slurry. The slurry contained approximately 10.0 mass% of cerium oxide particles (abrasive grains) based on the total mass.

[0093] A sample for particle size measurement was obtained by diluting the slurry with pure water so that the abrasive grain content was 0.25 mass% based on the total mass. For this sample, the average particle size of the abrasive grains was measured using a laser diffraction / scattering particle size distribution measuring device (manufactured by MicrotracBEL Corp., trade name: Microtrac MT3300EXII), and the average particle size was 140 nm.

[0094] <Preparation of polishing liquid for CMP> The slurry, each additive, and deionized water were mixed according to the following procedure to obtain polishing liquids having the compositions shown in the following tables (balance: deionized water). In the tables, "THEED" means 2,2’,2’’,2’’’-ethylenedinitrilotetraethanol, and "EDTP" means 1,1’,1’’,1’’’-ethylenedinitrilotetra-2-propanol. Each polishing liquid contained acetic acid in an amount corresponding to the respective abrasive grain content as the acetic acid mixed during the preparation of the above slurry.

[0095] Specifically, an additive solution was obtained by dissolving each additive in deionized water. Next, the above slurry and the additive solution were mixed in the same amount, and then stirred for 10 minutes to obtain a storage liquid for a concentrated polishing liquid containing 5.0% by mass of abrasive grains based on the total mass. The storage liquid for the polishing liquid contained 20 times the amount of abrasive grains and additives with respect to the abrasive grain content of 0.25% by mass in the final polishing liquid, and contained 5 times the amount of abrasive grains and additives with respect to the abrasive grain content of 1.00% by mass in the final polishing liquid.

[0096] Then, the storage liquid for the polishing liquid was diluted 20-fold with deionized water to obtain the polishing liquids of Examples A1, A4 and Comparative Example A1. Further, the storage liquid for the polishing liquid was diluted 5-fold with deionized water to obtain the polishing liquids of Examples A2 to A3, B1 to B6 and Comparative Examples A2 to A3, B1. For the polishing liquids of each example, when the abrasive grain content was 0.25% by mass based on the total mass (for the polishing liquid with an abrasive grain content of 1.00% by mass, when adjusted to an abrasive grain content of 0.25% by mass), the average particle size of the abrasive grains was equivalent to the average particle size of the abrasive grains in the above slurry.

[0097] <Zeta potential measurement> An appropriate amount of the polishing liquid was put into the product named "DelsaNano C" manufactured by Beckman Coulter, Inc., and the measurement was performed twice at 25°C. The average value of the displayed zeta potential was obtained as the zeta potential. In each of the examples and comparative examples, the zeta potential of the abrasive grains was positive.

[0098] <pH measurement> (pH of the polishing liquid) The pH of the polishing solution was measured under the following conditions, and the results are shown in the tables. Measurement temperature: 25℃ Measuring device: Horiba Ltd. product name: Model (D-71) Measurement method: A pH meter was calibrated at three points using a phthalate pH standard solution (pH: 4.01), a neutral phosphate pH standard solution (pH: 6.86), and a borate pH standard solution (pH: 9.18) as pH standard solutions, and then the pH meter electrode was placed in the polishing solution and the pH was measured using the measuring device after it had stabilized for 2 minutes or more.

[0099] <Evaluation of polishing characteristics> (Preparation of evaluation wafer) As a blanket wafer (BKW), a wafer with no pattern and a diameter of φ200 mm having a silicon oxide film (SiO2, initial film thickness: 1000 nm) on its surface was prepared.

[0100] A test patterned wafer (manufactured in-house, φ200mm) with a silicon oxide film (initial film thickness: 7200nm) with a concave-convex pattern on the surface was prepared as the patterned wafer (PTW). The convex parts (line parts) have an initial step height 6000nm higher than the concave parts (space parts), and the convex parts are intended for evaluation of high-step / low-density protrusions polished by etch-back. The patterned wafer has multiple 26mm x 26mm die units, and each die unit has multiple (4) 13mm x 13mm unit areas. Evaluation was performed in one of the unit areas, a parallel line pattern area with a line / space (L / S) of 30μm / 570μm (convex density: 5%).

[0101] (Polishing procedure) The above-mentioned evaluation wafer was polished using a polishing device (Applied Materials, product name: Mirra3400). The above-mentioned evaluation wafer was set on a holder having an adsorption pad for mounting a substrate. A polishing pad made of porous urethane resin (K-groove groove, DuPont (Dow), model number: IC-1010) was attached to a polishing platen with a diameter of 500 mm.

[0102] The holder was placed on the polishing pad with the surface of the evaluation wafer facing downward. The inner tube pressure, the retaining ring pressure, and the membrane pressure were set to 14 kPa, 21 kPa, and 14 kPa, respectively.

[0103] Then, the polishing pad attached to the polishing platen was subjected to a 93-minute period while the above-mentioned polishing liquid was dropped onto the polishing pad at a flow rate of 200 mL / min. -1 and 87 min. -1 The polished surface was polished by rotating at 400°C. Blanket wafers were polished for 30 seconds. Patterned wafers were polished for 60 seconds, which was the polishing time required to leave protruding portions after polishing. Next, the polished evaluation wafers were thoroughly washed with pure water using a PVA brush (polyvinyl alcohol brush) and then dried.

[0104] (Evaluation of polishing speed) The change in the thickness of the film being polished before and after polishing was measured using an optical interference film thickness measuring device (Nanometrics Japan, product name: AFT-5100) as shown below, and the polishing rate was obtained. The results are shown in each table.

[0105] For blanket wafers, the change in film thickness was measured at a total of 41 measurement points (20 points on both sides of the center point), including the center point of the wafer and points spaced 5 mm apart from the center in the diametric direction (the next measurement point after the measurement point 95 mm from the center was 97 mm from the center). The change in film thickness over a 30-second polishing time was measured at these 41 points, and the average value was obtained as the polishing rate for the blanket wafer.

[0106] For patterned wafers, the amount of change in film thickness was measured at one location on the central convex part (30 μm wide line) of the L / S = 30 μm / 570 μm pattern of one unit area (13 mm × 13 mm) in the central die unit (26 mm × 26 mm) of the patterned wafer, and the polishing rate of the patterned wafer was obtained.

[0107] [Table 1]

[0108] [Table 2] [Explanation of symbols]

[0109] 10...ILD film, 20...wiring, 30...silicon oxide film, 40...contact plug, 100, 100a...substrate, D...step.

Claims

1. The method includes the steps of: the abrasive grains include cerium-based particles; The additive comprises (A1) a 4-pyrone compound represented by the following general formula (1) and (B) a compound having two or more nitrogen atoms to which a hydroxyalkyl group is bonded: 【Chemistry 1】 [In the formula, X １１ , X １２ and X １３ are each independently a hydrogen atom or a monovalent substituent.

2. 2. The polishing slurry for CMP according to claim 1, wherein the component (A1) comprises at least one member selected from the group consisting of 3-hydroxy-2-methyl-4-pyrone, 5-hydroxy-2-(hydroxymethyl)-4-pyrone, and 2-ethyl-3-hydroxy-4-pyrone.

3. 2. The polishing slurry for CMP according to claim 1, wherein the content of the component (A1) is 0.001 to 5 mass %.

4. 2. The polishing liquid for CMP according to claim 1, wherein the component (B) contains ethylenedinitrilotetraethanol.

5. 2. The polishing liquid for CMP according to claim 1, wherein the component (B) contains ethylenedinitrilotetrapropanol.

6. 2. The polishing slurry for CMP according to claim 1, wherein the content of the component (B) is 0.001 to 5 mass %.

7. The polishing liquid for CMP according to claim 1 , wherein the additive further comprises a saturated monocarboxylic acid.

8. 2. The polishing liquid for CMP according to claim 1, having a pH of 8.0 or less.

9. The method includes the steps of: the abrasive grains include cerium-based particles; The polishing liquid for CMP, wherein the additive comprises (A2) picolinic acid and (B) a compound having two or more nitrogen atoms to which a hydroxyalkyl group is bonded.

10. 10. The polishing slurry for CMP according to claim 9, wherein the content of the component (A2) is 0.001 to 5 mass %.

11. 10. The polishing liquid for CMP according to claim 9, wherein the component (B) contains ethylenedinitrilotetraethanol.

12. 10. The polishing liquid for CMP according to claim 9, wherein the component (B) contains ethylenedinitrilotetrapropanol.

13. 10. The polishing slurry for CMP according to claim 9, wherein the content of the component (B) is 0.001 to 5 mass %.

14. 10. The polishing liquid for CMP according to claim 9, having a pH of 8.0 or less.

15. A polishing liquid set for CMP, comprising: a first liquid and a second liquid, the components of which are stored separately from each other in the polishing liquid for CMP according to any one of claims 1 to 14; the first liquid containing the abrasive grains and water; and the second liquid containing at least one of the additives and water.

16. A polishing method comprising a step of polishing a surface to be polished with the polishing slurry for CMP according to any one of claims 1 to 14.

17. The polishing method according to claim 16 , wherein the surface to be polished comprises silicon oxide.

18. 16. A polishing method comprising the step of polishing a surface to be polished with a polishing liquid for CMP obtained by mixing the first liquid and the second liquid in the polishing liquid set for CMP according to claim 15.

19. The polishing method according to claim 18 , wherein the surface to be polished comprises silicon oxide.

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