Polishing solution for CMP, polishing solution set for CMP, and polishing method

Abstract

To provide a polishing liquid for CMP that can achieve a high removal rate of silicon oxide on the protruding portions when polishing a patterned wafer having a fine uneven pattern.SOLUTION: A polishing liquid for CMP includes an abrasive grain, an additive, and water, the abrasive grain contains cerium-based particles, the average particle size of the abrasive grain exceeds 100 nm, the additive contains (A) a 4-pyrone-based compound represented by the following general formula (1), and (B2) a cyclic compound having at least one functional group selected from the group consisting of a carboxy group, a carboxylate group, an amino group, and a hydroxy group, the mass ratio of the content of the component (B2) to the content of the component (A) is 0.1 to 10. [X11, X12, and X13 are each independently a hydrogen atom or a monovalent substituent.]SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to polishing fluids for CMP (chemical mechanical polishing), polishing fluid sets for CMP, polishing methods, etc. [Background technology]

[0002] In the field of semiconductor manufacturing, as ultra-large-scale integrated circuits (ULSIs) become more high-performance, it is becoming increasingly difficult to achieve both high integration and high speed through miniaturization techniques that are merely extensions of conventional technologies. Therefore, technologies are being developed that allow for both miniaturization of semiconductor elements and high integration in the vertical direction (i.e., technologies for multi-layer wiring).

[0003] CMP (Chemical Plasma Coating) is one of the most important technologies in the manufacturing process of devices with multilayer wiring. CMP is a technique for planarizing the surface of a substrate obtained by forming a thin film on a substrate using chemical vapor deposition (CVD) or the like. For example, planarization by CMP is essential to ensure sufficient depth of focus in lithography. If there are irregularities on the surface of the substrate, problems such as the inability to focus during the exposure process or the inability to adequately form fine wiring structures will occur. CMP is also applied to processes in device manufacturing such as forming element isolation (inter-element isolation; STI: shallow trench isolation) regions by polishing plasma oxide films (BPSG, HDP-SiO2, p-TEOS, etc.); forming ILD films (interlayer insulating films; insulating films that electrically insulate metal components (wiring, etc.) from each other in the same layer); and planarizing plugs (e.g., Al·Cu plugs) after embedding silicon oxide films in metal wiring.

[0004] CMP is typically performed using a device that can supply polishing fluid onto a polishing pad. The surface of the substrate is polished by pressing the substrate against the polishing pad while supplying the polishing fluid between the substrate surface and the polishing pad. Thus, in CMP technology, the polishing fluid is one of the key technologies, and various polishing fluids have been developed to obtain high-performance polishing fluids (see, for example, Patent Document 1 below).

[0005] Among the processes to which the above-mentioned CMP technology is applied, the CMP process for ILD films, in particular, requires polishing silicon dioxide at a high polishing rate. For this reason, silica-based polishing solutions (polishing solutions using abrasive grains containing silica-based particles) with high polishing rates are mainly used in the CMP process for ILD films (see, for example, Patent Document 2 below). However, with silica-based polishing solutions, it is difficult to control polishing scratches, which are the cause of defects. Furthermore, with the miniaturization of wiring in recent years, it is desirable to reduce polishing scratches in the CMP process for ILD films, but unlike the CMP process for insulating films for device isolation regions, finish mirror polishing is generally not performed. For this reason, the use of cerium-based polishing solutions (polishing solutions using abrasive grains containing cerium-based particles), which produce fewer polishing scratches compared to silica-based polishing solutions, is being considered (see, for example, Patent Document 3 below). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2008-288537 [Patent Document 2] Japanese Patent Application Publication No. 9-316431 [Patent Document 3] Japanese Patent Application Publication No. 10-102038 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, in the case of cerium-based polishing liquids, it may be difficult to achieve a high polishing rate of silicon oxide, and particularly, in the polishing of a patterned wafer having a fine concavo-convex pattern composed of convex portions (e.g., Line portions) and concave portions (e.g., Space portions), it may be difficult to achieve a high polishing rate of silicon oxide in the convex portions.

[0008] One aspect of the present disclosure aims to provide a polishing liquid for CMP that can achieve a high polishing rate of silicon oxide in the convex portions in the polishing of a patterned wafer having a fine concavo-convex pattern. Another aspect of the present disclosure aims to provide a polishing liquid set for CMP for obtaining the polishing liquid for CMP. Still another aspect of the present disclosure aims to provide a polishing method using the polishing liquid for CMP or the polishing liquid set for CMP.

Means for Solving the Problems

[0009] The present disclosure relates to the following [1] to

[25] and the like in some aspects. [1] A polishing liquid for CMP containing abrasive grains, an additive, and water, wherein the abrasive grains include cerium-based particles, and the additive includes (A) a 4-pyrone compound represented by the following general formula (1) and (B1) a compound having a pH of 3.7 or more in a 1 mM aqueous solution.

Chemical formula

[10] The polishing liquid for CMP according to [8] or [9], wherein the component (B2) contains at least one selected from the group consisting of aromatic aminocarboxylic acids, quinolinecarboxylic acids, pyridinecarboxylic acids, and salts thereof.

[11] The polishing liquid for CMP according to any one of [8] to

[10] , wherein the component (B2) contains at least one selected from the group consisting of quinaldic acid and its salts.

[12] The polishing liquid for CMP according to any one of [8] to

[11] , wherein the component (B2) contains at least one selected from the group consisting of anthranilic acid and its salts.

[13] The polishing solution for CMP according to any one of [8] to

[12] , wherein the (B2) component comprises at least one selected from the group consisting of picolinic acid and salts thereof.

[14] A CMP polishing solution according to any one of [8] to

[13] , wherein the content of component (B2) is 0.001 to 5% by mass.

[15] A polishing solution for CMP comprising abrasive grains, an additive, and water, wherein the abrasive grains include cerium-based particles, and the additive includes a compound having two or more nitrogen atoms to which a hydroxyalkyl group is bonded.

[16] The polishing solution for CMP according to

[15] , wherein the compound having two or more nitrogen atoms to which the hydroxyalkyl group is bonded comprises ethylene dinitrilotetraethanol.

[17] The CMP polishing solution according to

[15] or

[16] , wherein the pH of the CMP polishing solution is 8.0 or less.

[18] The polishing solution for CMP according to any one of [1] to

[17] , wherein the cerium-based particles contain cerium oxide.

[19] A CMP polishing solution according to any one of [1] to

[18] , wherein the abrasive content is 0.01 to 10% by mass.

[20] The CMP polishing solution according to any one of [1] to

[19] , wherein component (A) comprises at least one 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.

[21] A CMP polishing solution according to any one of [1] to

[20] , wherein the content of component (A) is 0.001 to 5% by mass.

[22] The polishing solution for CMP according to any one of [1] to

[21] , wherein the additive further comprises a saturated monocarboxylic acid.

[23] The polishing solution for CMP according to

[22] , wherein the content of the saturated monocarboxylic acid is 0.0001 to 5% by mass. A set of polishing fluids for CMP, wherein the components of the polishing fluid for CMP described in any one of

[24] [1] to

[23] are stored separately as a first liquid and a second liquid, the first liquid comprising the abrasive grains and water, and the second liquid comprising at least one of the additives and water. A polishing method comprising the step of polishing a surface to be polished using a CMP polishing liquid described in any one of

[25] [1] to

[23] , or a CMP polishing liquid obtained by mixing the first liquid and the second liquid in the CMP polishing liquid set described in

[24] .

[26] The polishing method according to

[25] , wherein the surface to be polished contains silicon dioxide. [Effects of the Invention]

[0010] According to one aspect of this disclosure, a CMP polishing solution capable of achieving a high polishing rate of silicon oxide on the protrusions in pattern wafers having a fine uneven pattern can be provided. According to another aspect of this disclosure, a CMP polishing solution set for obtaining the CMP polishing solution can be provided. Furthermore, according to yet another aspect of this disclosure, a polishing method using the CMP polishing solution or the CMP polishing solution set can be provided. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic cross-sectional view showing the process of polishing the ILD film. [Modes for carrying out the invention]

[0012] The embodiments of this disclosure will be described in detail below.

[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" in a numerical range means A and a range exceeding A. "A or less" in 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 either A or B, or both. The materials exemplified in this specification can be used alone or in combination of two or more, 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, unless otherwise specified, when there are a plurality of substances corresponding to each component in the composition. The terms "layer" or "film" include, when observed as a plan view, not only the structure formed over the entire surface but also the structure formed partially. The term "step" includes not only an independent step but also the step in question even if it cannot be clearly distinguished from other steps, as long as the intended action of the step is achieved. "(Meth)acrylate" means at least one of acrylate and the corresponding methacrylate. The same applies to other similar expressions such as "(meth)acrylic acid".

[0014] <Polishing liquid for CMP> The polishing liquid for CMP according to this embodiment (the first embodiment, the second embodiment, and the third embodiment; the same applies hereinafter) is a polishing liquid for CMP (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 (A) a 4-pyrone compound represented by the following general formula (1) ((A) component) and (B1) a compound having a pH of 3.7 or more in an aqueous solution of 1 mM (millimolar concentration) ((B1) component). The additive of the polishing liquid according to the second embodiment includes (A) a 4-pyrone compound represented by the following general formula (1) ((A) component) and (B2) a cyclic compound having at least one functional group selected from the group consisting of a carboxy group, a carboxylate group, an amino group, and a hydroxy group (hydroxyl group) ((B2) component). The additive of the polishing liquid according to the third embodiment includes a compound having two or more nitrogen atoms to which a hydroxyalkyl group is bonded (hereinafter, sometimes referred to as "nitrogen-containing hydroxyalkyl compound"; ethylenedinitrilotetraethanol, ethylenedinitrilotetrapropanol, etc.). The nitrogen-containing hydroxyalkyl compound may be either a compound corresponding to the (B1) component or a compound not corresponding to the (B1) component. Ethylenedinitrilotetraethanol and ethylenedinitrilotetrapropanol are compounds corresponding to the (B1) component. The additive of the polishing liquid according to this embodiment may include the (A) component, the (B1) component, and the (B2) component.

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

[0016] The polishing solution according to this embodiment makes it possible to achieve a high polishing rate of silicon oxide in the convex portions when polishing a pattern wafer having a fine uneven pattern composed of convex portions (e.g., line portions) and concave portions (e.g., space portions). For example, a high polishing rate of silicon oxide in the convex portions can be achieved when polishing a region of Line / Space (L / S) = 20 μm / 80 μm on a pattern wafer (according to the polishing solution according to this embodiment, a polishing rate of 300 nm / min or more for silicon oxide in the convex portions in the L / S = 20 μm / 80 μm region can be obtained in the evaluation method described in the examples below).

[0017] The factors contributing to these effects are not entirely clear, but are presumed to be as follows. However, the factors are not limited to those listed below. Specifically, using component (A) increases the interaction between the polishing solution and silicon dioxide, and using component (B1) or (B2) also increases the interaction between the polishing solution and silicon dioxide. However, when component (A) is used without using components (B1) and (B2), and when component (B1) or (B2) is used without using component (A), excluding nitrogen-containing hydroxyalkyl compounds (ethylenedinitrilotetraethanol, ethylenedinitrilotetrapropanol, etc.), although high-speed polishing of silicon dioxide on blanket wafers without uneven patterns is possible by using cerium-based particles, which have lower hardness compared to silica-based particles, a high polishing rate of silicon dioxide on the convex parts of patterned wafers cannot be achieved. In particular, a specific phenomenon has been observed where a high polishing rate of silicon dioxide on the convex parts cannot be achieved in the polishing region of patterned wafers where L / S = 20 μm / 80 μm. On the other hand, according to the polishing solutions of the first and second embodiments, the interaction between the polishing solution and the silicon oxide on the protrusions is increased due to the synergistic effect resulting from the use of component (A) and component (B1) or (B2) (for example, the chemical reaction between the cerium-based particles in the polishing solution and the silicon oxide on the protrusions (a reaction derived from the Si-O-Ce bond) is promoted), making it possible to obtain a high polishing rate for the silicon oxide on the protrusions, and a high polishing rate for the silicon oxide on the protrusions can be achieved when polishing the L / S = 20 μm / 80 μm region on a pattern wafer. Furthermore, according to the polishing solution of the third embodiment, even if component (A) is not used, a similar effect can be obtained by using a nitrogen-containing hydroxyalkyl compound (ethylene dinitrilotetraethanol, ethylene dinitrilotetrapropanol, etc.).

[0018] According to one embodiment of the polishing solution of this embodiment, it is possible to achieve high-speed polishing of silicon dioxide on a blanket wafer without an uneven pattern (for example, a polishing speed of 100 nm / min or more (preferably 250 nm / min or more)) while also achieving a high polishing speed of silicon dioxide on the raised areas in the L / S = 20 μm / 80 μm region of a patterned wafer.

[0019] According to one embodiment of the polishing solution of this embodiment, a high polishing rate of silicon dioxide on the convex portions can be achieved when polishing the L / S = 30 μm / 70 μm region on a patterned wafer.

[0020] According to one embodiment of the polishing solution of this embodiment, even when using small-particle abrasive grains or when the abrasive grain content is low, a high polishing rate of silicon dioxide on the protrusions can be obtained when polishing a pattern wafer.

[0021] In the process of forming an element isolation region, it is required to suppress the polishing rate of the silicon nitride film used as a stopper for the silicon oxide film substrate, and high polishing selectivity of silicon oxide over silicon nitride (polishing rate of silicon oxide / polishing rate of silicon nitride) is sometimes required. According to one embodiment of the polishing solution of this embodiment, it is possible to obtain a sufficiently low polishing rate of silicon nitride and to obtain high polishing selectivity of silicon oxide over silicon nitride. In this case, it is suitable for polishing when forming an element isolation region. According to one embodiment of the polishing solution of this embodiment, in the evaluation method described in the examples below, a polishing rate of silicon nitride on the blanket wafer of, for example, less than 2.0 nm / min (preferably less than 1.0 nm / min, etc.) can be obtained.

[0022] According to one embodiment of the polishing solution of this embodiment, in polishing a pattern wafer having a square-shaped convex pattern (density of convex parts: 100%) and a square-shaped concave pattern (density of convex parts: 0%), the polishing speed of the concave pattern (density of convex parts: 0%) can be suppressed as an indicator of dishing characteristics. In this case, for example, in polishing the silicon oxide film on a pattern wafer having a silicon oxide film on its surface (including pattern wafers having a silicon nitride film as a stopper base in the case of STI formation), when the silicon oxide film for the thickness of the initial step is polished, the polishing of the silicon oxide film in the concave parts also progresses, or in patterns with a sufficiently wide width, the silicon oxide film in the concave parts is polished faster than the silicon oxide film on the convex parts, making it easier to suppress the phenomenon of the concave parts becoming concave like a dish (dishing). According to one embodiment of the polishing solution of this embodiment, in the evaluation method described in the examples below, a polishing speed of 500 nm / min or less (preferably 300 nm / min or less, 200 nm / min or less, etc.) can be obtained as the polishing speed of 0% convex parts.

[0023] According to one embodiment of the polishing solution of this embodiment, when polishing a pattern wafer having a square-shaped convex pattern (density of convex parts: 100%) and a square-shaped concave pattern (density of convex parts: 0%), a high polishing speed ratio of 100% convex / 0% convex can be obtained as an indicator of planarization efficiency. According to one embodiment of the polishing solution of this embodiment, in the evaluation method described in the examples below, a polishing speed ratio of 100% convex / 0% convex can be obtained as a polishing speed ratio of 1.0 or more.

[0024] The polishing solution according to this embodiment can be used in CMP of semiconductor wafer materials, and for example, it can be used to polish a silicon oxide film provided on the surface of a semiconductor wafer. The polishing solution according to this embodiment can be used in the CMP process of an ILD film. According to one embodiment of the polishing solution according to this embodiment, it is possible to obtain a high polishing speed while suppressing the aggregation of abrasive grains and the generation of polishing scratches, and obtaining high flatness.

[0025] (Abrasive grains) The abrasive grains include cerium-based particles. By using cerium-based particles as abrasive grains, it is easier to obtain a high polishing rate for silicon oxide on the raised areas of the pattern wafer while reducing polishing scratches on the polished surface.

[0026] Examples of cerium compounds used in cerium-based particles include cerium oxide, cerium hydroxide, cerium ammonium nitrate, cerium acetate, cerium sulfate hydrate, cerium bromate, cerium bromide, cerium chloride, cerium oxalate, cerium nitrate, and cerium carbonate. Cerium-based particles may contain cerium oxide from the viewpoint of easily achieving a high polishing rate of silicon oxide in the raised areas of the patterned wafer (raised areas in the L / S = 20 μm / 80 μm region, raised areas in the L / S = 30 μm / 70 μm region, etc.; the same applies hereinafter). By using cerium-based particles containing cerium oxide (cerium oxide particles), it is easier to achieve a high polishing rate of silicon oxide in the raised areas of the patterned wafer, and it is easier to obtain a polished surface with fewer polishing scratches and excellent flatness.

[0027] 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 while active surfaces appear one after another, and can maintain a high polishing rate of silicon oxide in the convex parts of the patterned wafer.

[0028] Methods for producing cerium oxide particles include calcination and oxidation using hydrogen peroxide. When calcining, the calcination temperature may be between 350 and 900°C. If 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 wet pulverization using a planetary bead mill. A jet mill described in, for example, "Journal of Chemical Engineering," Vol. 6, No. 5, (1980), pp. 527-532 can be used.

[0029] The zeta potential (surface potential) of abrasive grains in the polishing solution 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 patterned wafers and easily achieving high-speed polishing of silicon oxide on blanket wafers without uneven patterns. The zeta potential of abrasive grains can be measured, for example, using a dynamic light scattering zeta potential measuring device (e.g., DelsaNano C, manufactured by Beckman Coulter, Inc.). The zeta potential of abrasive grains can be adjusted using additives. For example, abrasive grains with a positive zeta potential can be obtained by contacting them with an acidic component (e.g., acetic acid).

[0030] The average particle size of the abrasive grains may be 50 nm or more, 70 nm or more, 100 nm or more, greater 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 speed of silicon oxide on the convex parts of the pattern wafer and easily achieving high-speed polishing of silicon oxide on blanket wafers without uneven patterns. 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, 140 nm or less, 135 nm or less, 130 nm or less, 125 nm or less, or 120 nm or less, from the viewpoint of easily suppressing the occurrence of polishing scratches and efficiently obtaining the effect of improving flatness such as suppressing dishing of the pattern wafer. From these perspectives, the average particle size of the abrasive grains may be 50-500 nm, 50-200 nm, 50-150 nm, 70-500 nm, 70-200 nm, 70-150 nm, 100-500 nm, 100-200 nm, or 100-150 nm. By adjusting the average particle size of the abrasive grains, a high polishing speed and low scratch characteristics of silicon oxide corresponding to the average particle size of the abrasive grains can be efficiently obtained.

[0031] "Average particle size of abrasive grains" refers to the median of the volume distribution measured using a laser diffraction / scattering particle size distribution analyzer on a sample of slurry containing dispersed abrasive grains. This can be measured using a device such as the Microtrac MT3300EXII manufactured by MicrotracBEL Corp. For example, a sample can be prepared by dispersing abrasive grains in water so that the abrasive grain content is 0.25% by mass based on the total mass of the sample. This sample is then placed in the measuring device and the median of the volume distribution is measured. When measuring the particle size of abrasive grains in a polishing solution, a sample can be prepared by adjusting the abrasive grain content in the polishing solution so that the abrasive grain content is 0.25% by mass based on the total mass of the sample. This sample can then be measured using the same method.

[0032] The abrasive content may be within the following ranges based on the total mass of the polishing solution, from the viewpoint of achieving an excellent balance between the polishing rate of silicon dioxide on the raised parts of the pattern wafer and the dispersion stability of the abrasive grains. The abrasive content may be 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.15% by mass or more, 0.2% by mass or more, 0.25% by mass or more, 0.3% by mass or more, 0.5% by mass or more, 0.8% by mass or more, or 1% by mass or more. The abrasive content may be 10% by mass or less, 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, or 0.25% by mass or less. From these perspectives, the abrasive content may be 0.01-10% by mass, 0.01-1% by mass, 0.01-0.5% by mass, 0.01-0.25% by mass, 0.05-10% by mass, 0.05-1% by mass, 0.05-0.5% by mass, 0.05-0.25% by mass, 0.1-10% by mass, 0.1-1% by mass, 0.1-0.5% by mass, or 0.1-0.25% by mass.

[0033] (Additives) [(A) Component: 4-pyrone compound] The additives in the polishing fluid according to the first and second embodiments include a 4-pyrone compound represented by general formula (1) (hereinafter, sometimes simply referred to as "4-pyrone compound") as component (A). It is presumed that using a 4-pyrone compound increases the interaction between the polishing fluid and silicon dioxide, thereby increasing the polishing speed. Furthermore, although the 4-pyrone compound is an additive that can increase the interaction between the polishing fluid and silicon dioxide, it does not have the effect of weakening repulsive forces such as electrostatic repulsion between abrasive grains, and is therefore thought to be able to suppress the aggregation of abrasive grains.

[0034] 4-pyrone compounds are compounds represented by the following general formula (1), and have a structure in which a hydroxyl group is bonded to a carbon atom adjacent to the carbon atom of the carbonyl group. A "4-pyrone compound" is a heterocyclic compound having an oxy group and a carbonyl group, and a γ-pyrone ring (6-membered ring) in which the carbonyl group is located at the 4th position relative to the oxy group. In 4-pyrone compounds, a hydroxyl group is bonded to a carbon atom adjacent to the carboxyl group in this γ-pyrone ring, and the other carbon atoms may be substituted with substituents other than hydrogen atoms.

[0035] [ka]

[0036] In the formula, X 11 , X 12 and X 13 Each of these is independently a hydrogen atom or a monovalent substituent. Examples of monovalent substituents include aldehyde groups, hydroxyl groups, carboxyl groups, carboxylic acid bases, sulfonic acid groups, phosphate groups, bromine atoms, chlorine atoms, iodine atoms, fluorine atoms, nitro groups, hydrazine groups, alkyl groups (e.g., alkyl groups having 1 to 8 carbon atoms), aryl groups (e.g., aryl groups having 6 to 12 carbon atoms), and alkenyl groups (e.g., alkenyl groups having 1 to 8 carbon atoms). Alkyl groups, aryl groups, and alkenyl groups may be substituted with OH, COOH, Br, Cl, I, NO2, etc. 11 , X 12 and X13 If it has a monovalent substituent, the substituent may be bonded to a carbon atom adjacent to the oxy group, i.e., X 11 and X 12 X may be a substituent. 11 , X 12 and X 13 At least two of them may be hydrogen atoms.

[0037] The 4-pyrone 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 speed of silicon dioxide on the convex parts of the pattern wafer and easily suppressing the aggregation of abrasive grains. The 4-pyrone compound can be used alone or in combination of two or more. When two or more 4-pyrone compounds are used in combination, it tends to be possible to improve the polishing speed of flat surfaces to be polished, as well as improve in-plane uniformity.

[0038] 4-pyrone compounds may be water-soluble. By using compounds with high solubility in water, the desired amount of additive can be well dissolved in the polishing solution, thereby achieving an even higher level of improvement in polishing speed and suppression of abrasive particle aggregation. The solubility of 4-pyrone compounds in 100g of water at room temperature (25°C) may be 0.001g or more, 0.005g or more, 0.01g or more, or 0.05g or more. There is no particular upper limit on solubility.

[0039] The content of the 4-pyrone compound may be within the following ranges based on the total mass of the polishing solution, from the viewpoint of more efficiently obtaining the effect of improving the polishing speed of the protrusions on the patterned wafer: The content of the 4-pyrone compound may be 0.001% by mass or more, 0.005% by mass or more, 0.01% by mass or more, 0.015% by mass or more, 0.02% by mass or more, 0.025% by mass or more, 0.03% by mass or more, 0.03% by mass or more, 0.032% by mass or more, 0.034% by mass or more, 0.035% by mass or more, 0.04% by mass or more, 0.05% by mass or more, 0.08% by mass or more, 0.1% by mass or more, 0.13% by mass or more, 0.15% by mass or more, 0.18% by mass or more, or 0.2% by 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 perspectives, the content of the 4-pyrone compound may be 0.001-5% by mass, 0.001-1% by mass, 0.001-0.3% by mass, 0.001-0.1% by mass, 0.001-0.05% by mass, 0.01-5% by mass, 0.01-1% by mass, 0.01-0.3% by mass, 0.01-0.1% by mass, 0.01-0.05% by mass, 0.02-5% by mass, 0.02-1% by mass, 0.02-0.3% by mass, 0.02-0.1% by mass, or 0.02-0.05% by mass.

[0040] The mass ratio A (4-pyrone compound / abrasive grain) of the 4-pyrone compound content to the abrasive grain content may be within the following ranges from the viewpoint of more efficiently obtaining the effect of improving the polishing speed of the protrusions on the pattern wafer. The mass ratio A 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 A 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 perspectives, the mass ratio A may be 0.01-1, 0.01-0.3, 0.01-0.15, 0.1-1, 0.1-0.3, 0.1-0.15, 0.12-1, 0.12-0.3, or 0.12-0.15.

[0041] [(B1) Component: A compound whose pH in a 1 mM aqueous solution is 3.7 or higher] The additive in the polishing solution according to the first embodiment includes component (B1) (excluding compounds corresponding to component (A)), and the additive in the polishing solution according to the third embodiment may include, for example, ethylenedinitrilotetraethanol or ethylenedinitrilotetrapropanol as the compound corresponding to component (B1) (nitrogen-containing hydroxyalkyl compound). Compounds corresponding to component (B2) can also be used as component (B1). By using component (B1), a high polishing rate of silicon oxide on the convex parts of the uneven pattern can be obtained by increasing the interaction between the polishing solution and silicon oxide on the convex parts of the uneven pattern. Compounds that can be acid-dissociated in multiple stages have multiple pKas, so selecting an effective compound based on pKa is complicated, but with the polishing solution according to the first embodiment, this complexity can be avoided by selecting the compound based on the pH that the compound provides in a 1 mM aqueous solution. According to the first embodiment, it is possible to provide an additive selection method for a polishing solution based on the pH given in a 1 mM aqueous solution, and an additive selection method for a polishing solution based on the pH given in a 1 mM aqueous solution is available that can achieve a high polishing rate of silicon dioxide on the convex parts when polishing a pattern wafer having a fine uneven pattern.

[0042] The pH (at 25°C) of a 1 mM aqueous solution of component (B1) is 3.7 or higher, from the viewpoint of obtaining a high polishing rate of silicon dioxide on the raised parts of the pattern wafer. The pH of a 1 mM aqueous solution of component (B1) may be within the following range, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the raised parts of the pattern wafer. The pH of a 1 mM aqueous solution of component (B1) may be 3.8 or higher, 4.0 or higher, 4.5 or higher, 5.0 or higher, greater than 5.0, 5.4 or higher, 5.5 or higher, 5.6 or higher, 5.8 or higher, 5.9 or higher, 6.0 or higher, 6.2 or higher, 6.5 or higher, 6.7 or higher, 7.0 or higher, 7.2 or higher, 7.5 or higher, 8.0 or higher, 8.5 or higher, 8.6 or higher, 9.0 or higher, 9.2 or higher, 9.4 or higher, 9.5 or higher, 9.8 or higher, 10.0 or higher, or 10.2 or higher. The pH of a 1 mM aqueous solution of component (B1) may be 14.0 or less, 13.0 or less, 12.0 or less, 11.0 or less, 10.5 or less, 10.2 or less, 10.0 or less, 9.8 or less, 9.5 or less, 9.4 or less, 9.2 or less, 9.0 or less, 8.6 or less, 8.5 or less, 8.0 or less, 7.5 or less, 7.2 or less, 7.0 or less, 6.7 or less, 6.5 or less, 6.2 or less, 6.0 or less, 5.9 or less, 5.8 or less, 5.6 or less, 5.5 or less, or 5.4 or less. From these perspectives, the pH of a 1 mM aqueous solution of component (B1) may be 3.7-14.0, 3.7-12.0, 3.7-11.0, 5.0-14.0, 5.0-12.0, 5.0-11.0, 8.0-14.0, 8.0-12.0, 8.0-11.0, 10.0-14.0, 10.0-12.0, or 10.0-11.0. A 1 mM aqueous solution of component (B1) is a mixture consisting of component (B1) and water.

[0043] (B1) Examples of components include amino acids, pyridine compounds (compounds having a pyridine ring), imidazole compounds (compounds having an imidazole ring), pyrazole compounds (compounds having a pyrazole ring), triazole compounds (compounds having a triazole ring), compounds containing an amino group and a benzene ring, 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.), triethanolamine (2,2',2''-nitrilotriethanol, etc.).

[0044] Examples of amino acids include histidine (L-histidine, etc.), lysine, arginine, glutamine (L-glutamine, etc.), glutamic acid (L-glutamic acid, etc.), proline (L-proline, etc.), bicine, cysteine ​​(L-cysteine, etc.), alanine (L-alanine, etc.), serine (L-serine, etc.), aminoacetic acid (glycine), tyrosine (L-tyrosine, etc.), and phenylalanine. The amino acids may be basic amino acids or aromatic amino acids. Examples of pyridine compounds include pyridine, hydroxypyridine (3-hydroxypyridine, 4-hydroxypyridine, etc.), pyridinecarboxylic acid (nicotinic acid, picolinic acid, etc.), methylpyridine (2-methylpyridine, etc.), acetylpyridine (2-acetylpyridine, etc.), pyridineethanol (2-pyridineethanol, etc.), and aminopyridine (3-aminopyridine, etc.). Examples of imidazole compounds include imidazole, methylimidazole (2-methylimidazole, etc.), and dimethylimidazole (1,2-dimethylimidazole, etc.). Examples of pyrazole compounds include pyrazole and methylpyrazole. Examples of triazole compounds include triazole (1,2,4-triazole, etc.) and aminotriazole (3-amino-1,2,4-triazole, etc.). Examples of compounds containing an amino group and a benzene ring include aminobenzene (aniline) and anthranilic acid.

[0045] Component (B1) may contain at least one selected from the group consisting of amino acids, pyridine compounds, imidazole compounds, pyrazole compounds, triazole compounds, compounds containing an amino group and a benzene ring, ethylenedinitrilotetraethanol, ethylenedinitrilotetrapropanol, and triethanolamine, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the convex parts of the pattern wafer, and may contain at least one selected from the group consisting of amino acids, pyridine compounds, imidazole compounds, pyrazole compounds, triazole compounds, and ethylenedinitrilotetraethanol, and may contain basic amino acids, aromatic amino acids, aminoacetic acid, hydroxypyridine, methylpyridine, acetylpyridine, pyridineethanol, aminopyridine, imidazole, pyrazole, triazole, ethylenedinitrilotetraethanol It may contain at least one selected from the group consisting of tanol, ethylenedinitrilotetrapropanol, and triethanolamine, and may contain at least one selected from the group consisting of basic amino acids, aromatic amino acids, aminoacetic acid, hydroxypyridine, methylpyridine, acetylpyridine, pyridineethanol, aminopyridine, imidazole, pyrazole, triazole, ethylenedinitrilotetraethanol, and triethanolamine, and may contain at least one selected from the group consisting of histidine, glutamine, glutamic acid, proline, bicine, cysteine, alanine, serine, aminoacetic acid, tyrosine, hydroxypyridine, pyridineethanol, imidazole, methylimidazole, ethylenedinitrilotetraethanol, ethylenedinitrilotetrapropanol, and triethanolamine. In particular, component (B1) may be an embodiment containing hydroxypyridine, an embodiment containing ethylenedinitrilotetraethanol, an embodiment containing ethylenedinitrilotetrapropanol, or an embodiment containing triethanolamine. Component (B1) may include compounds that do not fall under the category of aromatic polyoxyalkylene compounds (compounds having an aromatic ring and a polyoxyalkylene chain), compounds that do not have an aromatic ring, and compounds that do not have a polyoxyalkylene chain, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the convex parts of the pattern wafer.

[0046] The molecular weight of component (B1) may be within the following range, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide in the convex parts of the pattern wafer. The molecular weight of component (B1) 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, greater than 250, or 280 or more. The molecular weight of component (B1) 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, 240 or less, 230 or less, 210 or less, 200 or less, 180 or less, 170 or less, 160 or less, 150 or less, 148 or less, 140 or less, 130 or less, 125 or less, 123 or less, 120 or less, 110 or less, 100 or less, 90 or less, 85 or less, 80 or less, or 70 or less. From these perspectives, the molecular weight of component (B1) may be 50-1000, 50-500, 50-300, 50-200, 100-1000, 100-500, 100-300, 100-200, 150-1000, 150-500, 150-300, or 150-200.

[0047] The content of component (B1), the content of nitrogen-containing hydroxyalkyl compounds (total amount of compounds corresponding to component (B1) and compounds not corresponding to component (B1); the same applies hereinafter), the content of ethylenedinitrilotetraethanol, or the content of ethylenedinitrilotetrapropanol, is within the following ranges based on the total mass of the polishing solution, from the viewpoint of efficiently obtaining the effect of improving the polishing speed of silicon dioxide on the convex parts of the pattern wafer, the effect of improving the polishing speed of silicon dioxide on the blanket wafer, and the effect of improving the planarization efficiency. Content B1 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, 0.05 mass% or more, 0.06 mass% % or more, 0.08 mass% or more, 0.1 mass% or more, 0.11 mass% or more, 0.12 mass% or more, 0.13 mass% or more, 0.14 mass% or more, 0.15 mass% or more, 0.2 mass% or more, 0.25 mass% or more, 0.3 mass% or more, or 0.4 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, 0.25% by mass or less, 0.2% by mass or less, 0.15% by mass or less, 0.14% by mass or less, 0.13% by mass or less, 0.12% by mass or less, 0.11% by mass or less. Below, it may be 0.1% by mass or less, 0.08% by mass or less, 0.06% by mass or less, 0.05% by mass or less, 0.04% 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 perspectives, the content of B1 may be 0.001 to 5% by mass, 0.001 to 1% by mass, 0.001 to 0.3% by mass, 0.001 to 0.2% by mass, 0.001 to 0.1% by mass, 0.001 to 0.05% by mass, 0.01 to 5% by mass, 0.01 to 1% by mass, 0.01 to 0.3% by mass, 0.01 to 0.2% by mass, 0.01 to 0.1% by mass, 0.01 to 0.05% by mass, 0.03 to 1% by mass, 0.03 to 0.3% by mass, 0.03 to 0.2% by mass, 0.03 to 0.1% by mass, or 0.03 to 0.05% by mass.The content of component (B1) includes the content of compounds corresponding to component (B1) and component (B2) (the same applies hereinafter).

[0048] The mass ratio B11 may be within the following range, from the viewpoint of efficiently obtaining the effect of improving the polishing speed of silicon dioxide on the convex parts of the pattern wafer, the effect of improving the polishing speed of silicon dioxide on the blanket wafer, and the effect of improving the planarization efficiency. This can be expressed as the mass ratio of the content of component (B1) to the content of abrasive grains (component (B1) / abrasive grains), the mass ratio of the content of nitrogen-containing hydroxyalkyl compounds to the content of abrasive grains (nitrogen-containing hydroxyalkyl compounds / abrasive grains), the mass ratio of the content of ethylenedinitrilotetraethanol to the content of abrasive grains (ethylenedinitrilotetraethanol / abrasive grains), or the mass ratio of the content of ethylenedinitrilotetrapropanol to the content of abrasive grains (ethylenedinitrilotetrapropanol / abrasive grains). The mass ratio B11 may be 0.001 or greater, 0.005 or greater, 0.01 or greater, 0.05 or greater, 0.08 or greater, 0.1 or greater, 0.11 or greater, 0.12 or greater, 0.13 or greater, 0.14 or greater, 0.15 or greater, 0.16 or greater, 0.2 or greater, 0.25 or greater, 0.3 or greater, 0.4 or greater, 0.5 or greater, 1 or greater, or greater than 1. 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, 0.4 or less, 0.3 or less, 0.25 or less, 0.2 or less, 0.16 or less, 0.15 or less, 0.14 or less, 0.13 or less, 0.12 or less, 0.11 or less, 0.1 or less, 0.08 or less, 0.05 or less, or 0.01 or less. From these perspectives, the mass ratio B11 may be 0.001-10, 0.001-1, 0.001-0.3, 0.001-0.2, 0.001-0.1, 0.01-10, 0.01-1, 0.01-0.3, 0.01-0.2, 0.01-0.1, 0.1-10, 0.1-1, 0.1-0.3, or 0.1-0.2.

[0049] The mass ratio B12 may be within the following range, from the viewpoint of efficiently obtaining the effect of improving the polishing speed of silicon dioxide on the convex parts of the pattern wafer, the effect of improving the polishing speed of silicon dioxide on the blanket wafer, and the effect of improving the planarization efficiency. This can be expressed as the mass ratio of the content of component (B1) to the content of the 4-pyrone compound (component (B1) / 4-pyrone compound), the mass ratio of the content of nitrogen-containing hydroxyalkyl compound to the content of the 4-pyrone compound (nitrogen-containing hydroxyalkyl compound / 4-pyrone compound), the mass ratio of the content of ethylenedinitrilotetraethanol to the content of the 4-pyrone compound (ethylenedinitrilotetraethanol / 4-pyrone compound), or the mass ratio of the content of ethylenedinitrilotetrapropanol to the content of the 4-pyrone compound (ethylenedinitrilotetraethanol / 4-pyrone compound). The mass ratio B12 may be 0.01 or greater, 0.05 or greater, 0.1 or greater, 0.3 or greater, 0.5 or greater, 0.6 or greater, 0.8 or greater, 0.85 or greater, 0.9 or greater, 1 or greater, greater than 1, 1.1 or greater, 1.2 or greater, 1.4 or greater, 1.5 or greater, 2 or greater, 5 or greater, or 8 or greater. 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, or 0.1 or less. From these perspectives, the mass ratio B12 may be 0.01-10, 0.01-2, 0.01-1, 0.1-10, 0.1-2, 0.1-1, 0.8-10, 0.8-2, or 0.8-1.

[0050] [(B2) Component: A cyclic compound having at least one functional group selected from the group consisting of a carboxyl group, a carboxylic acid base, an amino group, and a hydroxyl group] The additive to the polishing solution according to the second embodiment includes component (B2) (excluding compounds corresponding to component (A)). By using component (B2), the interaction between the polishing solution and the silicon oxide in the raised parts of the uneven pattern is increased, thereby enabling a high polishing rate of the silicon oxide in the raised parts. Component (B2) may have at least one selected from the group consisting of a carboxyl group and a carboxylic acid base, from the viewpoint of easily obtaining a high polishing rate of silicon oxide in the raised parts of the pattern wafer. Compounds corresponding to component (B1) can also be used as component (B2). If it is necessary to distinguish whether such a compound belongs to component (B1) or component (B2), the compound shall be assigned to component (B2). Examples of carboxylic acid base salts include alkali metal salts such as sodium salts and potassium salts.

[0051] Component (B2) may have at least one selected from the group consisting of aromatic rings, heterocycles (excluding aromatic rings), and alicycles. The aromatic ring may be a heteroaromatic ring. Examples of aromatic rings include benzene rings, naphthalene rings, anthracene rings, pyridine rings, and quinoline rings. Component (B2) may have an aromatic ring different from a benzene ring.

[0052] Component (B2) may contain aromatic compounds (compounds having aromatic rings) from the viewpoint of easily obtaining a high polishing rate of silicon oxide on the convex parts of the pattern wafer, and may contain at least one selected from the group consisting of aromatic carboxylic acids (aromatic compounds having a carboxyl group) and aromatic carboxylic acid salts (aromatic compounds having a carboxylic acid base). Component (B2) may contain at least one selected from the group consisting of aromatic aminocarboxylic acids (aminobenzoic acid, aminobenzenesulfonic acid, etc.), aromatic oxycarboxylic acids (aromatic hydroxycarboxylic acids, excluding aromatic aminocarboxylic acids), aromatic carboxylic acids without amino and hydroxyl groups (quinoline carboxylic acid, pyridine carboxylic acid, etc.), and salts thereof, and may contain at least one selected from the group consisting of aromatic aminocarboxylic acids, quinoline carboxylic acid, pyridine carboxylic acid, and salts thereof.

[0053] Component (B2) may contain at least one selected from the group consisting of benzoic acid, benzoic acid derivatives, hydroxyphenylacetic acid, alkyl salicylic acid, phthalic acid, phthalic acid derivatives, quinoline derivatives, pyridine derivatives, aminobenzenesulfonic acid, salts thereof, and salicylaldoxime, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide in the convex portions of the pattern wafer and efficiently obtaining an effect of improving planarization efficiency.

[0054] The benzoic acid derivative may include at least one selected from the group consisting of hydroxybenzoic acid and aminobenzoic acid, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the raised parts of the pattern wafer. Examples of hydroxybenzoic acid include salicylic acid (2-hydroxybenzoic acid) and 4-hydroxybenzoic acid. Examples of aminobenzoic acid include anthranilic acid. Examples of hydroxyphenylacetic acid include mandelic acid. Examples of alkylsalicylic acid include methylsalicylic acid (e.g., 3-methylsalicylic acid). The phthalic acid derivative may include at least one selected from the group consisting of alkylphthalic acid, aminophthalic acid, and sulfophthalic acid, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the raised parts of the pattern wafer. Examples of alkylphthalic acid include methylphthalic acid (e.g., 4-methylphthalic acid). Examples of aminophthalic acid include 4-aminophthalic acid. Examples of sulfophthalic acid include 4-sulfophthalic acid. The quinoline derivative may contain quinoline carboxylic acid, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the raised parts of the patterned wafer. Examples of quinoline carboxylic acid include quinaldic acid. The pyridine derivative may contain pyridine carboxylic acid, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the raised parts of the patterned wafer. Examples of pyridine carboxylic acid include picolinic acid and nicotinic acid. Examples of aminobenzenesulfonic acid include ortanylic acid. In particular, component (B2) may be an embodiment containing at least one selected from the group consisting of quinaldic acid and its salts, an embodiment containing at least one selected from the group consisting of anthranilic acid and its salts, or an embodiment containing at least one selected from the group consisting of picolinic acid and its salts.

[0055] Component (B2) may include at least one selected from the group consisting of benzoic acid, 4-hydroxybenzoic acid, aminobenzoic acid, hydroxyphenylacetic acid, quinoline derivatives, and pyridine derivatives, from the viewpoint of easily achieving high-speed polishing of silicon dioxide on blanket wafers without uneven patterns (e.g., polishing speed of 250 nm / min or more).

[0056] The molecular weight of component (B2) may be within the following ranges, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the convex parts of the pattern wafer. The molecular weight of component (B2) may be 80 or more, 90 or more, 100 or more, 110 or more, 120 or more, 125 or more, 130 or more, 135 or more, 138 or more, 140 or more, 150 or more, 160 or more, or 170 or more. The molecular weight of component (B2) 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, 300 or less, 250 or less, 200 or less, 180 or less, 170 or less, 160 or less, 150 or less, 140 or less, 138 or less, 135 or less, 130 or less, or 125 or less. From these perspectives, the molecular weight of component (B2) may be 80-1000, 80-200, 80-150, 100-1000, 100-200, 100-150, 120-1000, 120-200, 120-150, 130-1000, 130-200, or 130-150.

[0057] The content of component (B2) may be within the following ranges based on the total mass of the polishing solution, from the viewpoint of efficiently obtaining the effect of improving the polishing speed of silicon dioxide on the raised parts of the pattern wafer, and from the viewpoint of easily achieving high-speed polishing of silicon dioxide on blanket wafers that do not have a raised or recessed pattern. The content of component (B2) may be 0.001% by mass or more, 0.005% by mass or more, 0.01% by mass or more, 0.015% by mass or more, 0.02% by mass or more, 0.025% by mass or more, 0.03% by mass or more, 0.035% by mass or more, 0.04% 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, 0.15% by mass or more, or 0.2% by mass or more. The content of component (B2) is 5% by mass or less, 3% by mass or less, 1% by mass or less, 0.5% 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 mass% or less, 0.04 mass% or less, 0.035 mass% or less, 0.03 mass% or less, 0.025 mass% or less, 0.02 mass% or less, 0.015 mass% or less, or 0.01 mass% or less. From these perspectives, the content of component (B2) may be 0.001 to 5% by mass, 0.001 to 1% by mass, 0.001 to 0.3% by mass, 0.001 to 0.1% by mass, 0.001 to 0.05% by mass, 0.01 to 5% by mass, 0.01 to 1% by mass, 0.01 to 0.3% by mass, 0.01 to 0.1% by mass, 0.01 to 0.05% by mass, 0.03 to 5% by mass, 0.03 to 1% by mass, 0.03 to 0.3% by mass, 0.03 to 0.1% by mass, or 0.03 to 0.05% by mass. The content of component (B2) also includes the content of compounds corresponding to component (B1) and component (B2) (the same applies hereinafter).

[0058] The mass ratio B21 ((B2) component / abrasive grains) of the content of component (B2) to the content of abrasive grains may be within the following range, from the viewpoint of easily obtaining a high polishing speed of silicon oxide on the convex parts of the pattern wafer and from the viewpoint of easily achieving high-speed polishing of silicon oxide on blanket wafers that do not have a relief pattern. The mass ratio B21 may be 0.01 or more, 0.03 or more, 0.04 or more, 0.05 or more, 0.08 or more, 0.1 or more, 0.12 or more, 0.15 or more, 0.16 or more, 0.2 or more, 0.25 or more, or 0.3 or more. The mass ratio B21 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, 0.2 or less, 0.16 or less, 0.15 or less, 0.12 or less, 0.1 or less, 0.08 or less, 0.05 or less, or 0.04 or less. From these viewpoints, the mass ratio B21 may be 0.01 to 1, 0.01 to 0.5, 0.01 to 0.2, 0.01 to 0.1, 0.05 to 1, 0.05 to 0.5, 0.05 to 0.2, 0.05 to 0.1, 0.1 to 1, 0.1 to 0.5, or 0.1 to 0.2.

[0059] The mass ratio B22 (component (B2) / 4-pyrone compound) of the content of component (B2) to the content of 4-pyrone compounds may be within the following ranges, from the viewpoint of easily obtaining a high polishing speed of silicon dioxide on the convex parts of the pattern wafer and from the viewpoint of easily achieving high-speed polishing of silicon dioxide on blanket wafers without uneven patterns. The mass ratio B22 may be 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.8 or more, 1 or more, 1.2 or more, 1.5 or more, or 2 or more. The mass ratio B22 may be 10 or less, 5 or less, 3 or less, 2 or less, 1.5 or less, 1.2 or less, 1 or less, 0.8 or less, 0.6 or less, 0.5 or less, 0.4 or less, or 0.3 or less. From these perspectives, the mass ratio B22 may be 0.1-10, 0.1-3, 0.1-2, 0.1-1, 0.3-10, 0.3-3, 0.3-2, 0.3-1, 1-10, 1-3, or 1-2.

[0060] [Nitrogen-containing hydroxyalkyl compounds] The additive to the polishing solution according to the third embodiment includes a compound having two or more nitrogen atoms to which a hydroxyalkyl group is bonded (nitrogen-containing hydroxyalkyl compound). In the nitrogen-containing hydroxyalkyl compound, the hydroxyalkyl group is directly bonded to the nitrogen atom, and the hydroxyl group is directly bonded to the alkyl group directly bonded to the nitrogen atom. In the nitrogen-containing hydroxyalkyl compound, an alkyl group that does not have substituents other than the hydroxyl group can be used as the hydroxyalkyl group bonded to the nitrogen atom.

[0061] From the viewpoint of easily obtaining a high polishing rate of silicon dioxide in the convex portions of the pattern wafer, the nitrogen-containing hydroxyalkyl compound may include a compound having a nitrogen atom bonded to two hydroxyalkyl groups, or may include a compound having two or more nitrogen atoms bonded to two hydroxyalkyl groups.

[0062] The number of nitrogen atoms in one molecule of the nitrogen-containing hydroxyalkyl compound may be 2-5, 2-4, or 2-3, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the raised parts of the patterned wafer. The number of hydroxyl groups in one molecule of the nitrogen-containing hydroxyalkyl compound may be 2-6, 2-5, 2-4, 3-6, 3-5, 3-4, 4-6, or 4-5, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the raised parts of the patterned wafer.

[0063] From the viewpoint of easily obtaining a high polishing rate of silicon dioxide in the raised areas of the patterned wafer, the nitrogen-containing hydroxyalkyl compound may have a hydroxyalkyl group with 1 to 4, 2 to 4, 3 to 4, 1 to 3, 2 to 3, or 1 to 2 carbon atoms as the hydroxyalkyl group bonded to the nitrogen atom. From the viewpoint of easily obtaining a high polishing rate of silicon dioxide in the raised areas of the patterned wafer, the nitrogen-containing hydroxyalkyl compound may have a hydroxyalkyl group with 1 to 3 or 1 to 2 hydroxyl groups as the hydroxyalkyl group bonded to the nitrogen atom.

[0064] From the viewpoint of easily obtaining a high polishing rate of silicon dioxide in the convex parts of the patterned wafer, the nitrogen-containing hydroxyalkyl compound may have an alkylene group between the two nitrogen atoms to which the hydroxyalkyl group is bonded, and the number of carbon atoms in the alkylene group may be 1-4, 2-4, 1-3, 2-3, or 1-2.

[0065] Nitrogen-containing hydroxyalkyl compounds may include compounds represented by the following general formula (I) from the viewpoint of easily obtaining a high polishing rate of silicon dioxide in the convex portions of the patterned wafer.

[0066] [ka] [In the formula, n is an integer greater than or equal to 1, R 11 , R 12 , R 13 and R 14 Each of these independently represents a hydrogen atom or an organic group, and R 11 and R 12 One or both of them are hydroxyalkyl groups, R 13 and R 14 One or both of them are hydroxyalkyl groups.

[0067] n may be within the range described above as the number of carbon atoms in the alkylene group between the two nitrogen atoms to which the hydroxyalkyl group is 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 substituents on the alkyl group include hydroxyl groups, carboxyl groups, amino groups, sulfo groups, nitro groups, etc. 11 , R 12 , R 13 or R 14 If the molecule is a hydroxyalkyl group, the number of carbon atoms in the hydroxyalkyl group may be within the range described above as the number of carbon atoms in the hydroxyalkyl group bonded to the nitrogen atom.

[0068] Examples of nitrogen-containing hydroxyalkyl compounds 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 obtaining a high polishing rate of silicon dioxide on the convex parts of the pattern wafer, the nitrogen-containing hydroxyalkyl compound may contain at least one selected from the group consisting of ethylenedinitrilotetraethanol and ethylenedinitrilotetrapropanol, and may contain ethylenedinitrilotetraethanol or ethylenedinitrilotetrapropanol. Nitrogen-containing hydroxyalkyl compounds may include compounds without a carboxyl group, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the raised parts of the patterned wafer.

[0069] The molecular weight of the nitrogen-containing hydroxyalkyl compound may be within the following ranges, from the viewpoint of easily obtaining a high polishing rate of silicon dioxide on the convex parts of the pattern wafer. The molecular weight of the nitrogen-containing hydroxyalkyl compound 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, greater than 250, or 280 or more. The molecular weight of the nitrogen-containing hydroxyalkyl compound 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 perspectives, the molecular weight of the nitrogen-containing hydroxyalkyl compound 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.

[0070] The content of nitrogen-containing hydroxyalkyl compounds may be within the range described above.

[0071] [Saturated monocarboxylic acid] The additives in the polishing solution according to this embodiment may include saturated monocarboxylic acid. By using saturated monocarboxylic acid, it is possible to obtain a sufficiently low polishing speed for silicon nitride that can be used as a stopper material, and not only improve the dispersibility of cerium-based particles, but also improve in-plane uniformity, which is an indicator of the variation in polishing speed within the polished surface, without reducing the polishing speed of the patterned wafer (for example, a semiconductor substrate having an uneven pattern).

[0072] Examples of saturated monocarboxylic acids 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. From the viewpoint of easily obtaining the above-mentioned additive effects of saturated monocarboxylic acids, aliphatic carboxylic acids may be included. From the viewpoint of effectively suppressing the polishing rate of silicon nitride and further improving the in-plane uniformity, saturated monocarboxylic acids having 2 to 6 carbon atoms may be included, and at least one selected from the group consisting of acetic acid and propionic acid may be included.

[0073] The content of saturated monocarboxylic acid (for example, saturated monocarboxylic acid having 2 to 6 carbon atoms) may be within the following ranges based on the total mass of the polishing solution, from the viewpoint of effectively obtaining the effect of improving in-plane uniformity, improving the polishing speed of the pattern wafer, and suppressing the polishing speed of silicon nitride. The content of saturated monocarboxylic acid may be 0.0001% by mass or more, 0.0005% by mass or more, 0.001% by mass or more, 0.002% by mass or more, 0.005% by mass or more, 0.01% by mass or more, 0.02% by mass or more, 0.03% by mass or more, 0.04% by mass or more, 0.045% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.2% by mass or more, 0.3% by mass or more, or 0.4% by mass or more. The saturated monocarboxylic acid content may be 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, 0.1% by mass or less, 0.05% by mass or less, or 0.045% by mass or less. From these viewpoints, the saturated monocarboxylic acid content may be 0.0001 to 5% by mass, 0.0001 to 1% by mass, 0.0001 to 0.1% by mass, 0.0001 to 0.05% by mass, 0.01 to 5% by mass, 0.01 to 1% by mass, 0.01 to 0.1% by mass, 0.01 to 0.05% by mass, 0.03 to 5% by mass, 0.03 to 1% by mass, 0.03 to 0.1% by mass, or 0.03 to 0.05% by mass. The content of saturated monocarboxylic acid may be 0.04% by mass or less, 0.03% by mass or less, 0.02% by mass or less, 0.01% by mass or less, 0.005% by mass or less, 0.002% by mass or less, 0.001% by mass or less, 0.0005% by mass or less, or substantially 0% by mass.

[0074] [Nonionic polymers and cationic compounds] The additive in the polishing solution according to this embodiment may include at least one selected from the group consisting of nonionic polymers and cationic compounds. In this case, a protective film is formed on the surface to be polished, and high flatness can be achieved by protecting the concave surface until the convex surface is worn away, while maintaining the high-speed polishing performance of the pattern wafer. When at least one of the nonionic polymer and cationic additive is used, such an effect can be obtained with a relatively small amount, and since there is no aggregation effect like that of anionic surfactants on a state where the surface potential of cerium-based particles (e.g., cerium oxide particles) is dispersed on the positive side, it is thought that high flatness can be obtained while reducing the occurrence of polishing scratches and also reducing the occurrence of dishing. However, the reason for the manifestation of the effect is not limited to the above. When at least one of the nonionic polymer and cationic additive is used, an effect of improving the in-plane uniformity of the polishing speed can also be obtained.

[0075] Examples of nonionic polymers include ether-type surfactants such as polyglycerin, polyglycerin fatty acid esters, polyoxyethylene distyrenated phenyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene lauryl ether, polyoxypropylene polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene polyoxypropylene ether derivatives, polyoxypropylene glyceryl ether, polyethylene glycol, methoxypolyethylene glycol, and oxyethylene adducts of acetylene diols; ester-type surfactants such as sorbitan fatty acid esters and glycerol borate fatty acid esters; amino ether-type surfactants such as polyoxyethylene alkylamines; ether ester-type surfactants such as polyoxyethylene glycerol borate fatty acid esters and polyoxyethylene alkyl esters; alkanolamide-type surfactants such as fatty acid alkanolamides and polyoxyethylene fatty acid alkanolamides; polyvinylpyrrolidone; nonionic polyacrylamide; and nonionic polydimethylacrylamide. Nonionic polymers may contain ether-type surfactants from the viewpoint of easily obtaining the above-mentioned additive effects of nonionic polymers.

[0076] From the viewpoint of efficiently obtaining the effect of improving the uniformity of the polishing speed in the plane and the effect of improving flatness such as suppressing dishing of pattern wafers, the content of nonionic polymer may be in the following ranges based on the total mass of the polishing solution. The content of nonionic polymer may be 0.05% by mass or more, 0.1% by mass or more, 0.15% by mass or more, or 0.2% by mass or more. The content of nonionic polymer may be 5% by mass or less, 3% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.3% by mass or less, or 0.2% by mass or less. From these viewpoints, the content of nonionic polymer may be 0.05 to 5% by mass.

[0077] The cationic compound may be at least one selected from the group consisting of cationic monomers and cationic polymers. Examples of cationic compounds include cationic monomers such as ethyleneimine, allylamine, dimethyl(meth)acrylamide, chitosan, diallylamine, methyldiallylamine, (meth)acrylic acid, diallyldimethylammonium chloride, (meth)acrylamide, dimethylamine, epichlorohydrin, ammonia, dimethylaminoethyl (meth)acrylate, dicyandiamide, diethylenetriamine, vinylpyrrolidone-dimethylaminoethyl (meth)acrylate diethyl sulfate, diallyldimethylammonium chloride-(meth)acrylamide, and diallylmethylethylammonium ethyl sulfate; cationic polymers of the cationic monomer (cationic homopolymers and cationic copolymers (dimethylamine / ammonia (NH3) / epichlorohydrin copolymer, dimethylamine / epichlorohydrin copolymer, etc.)); polymer compounds such as derivatives of the cationic monomer; and surfactants such as coconutamine acetate and stearylamine acetate. The cationic compound may include a reaction product of a starting material containing dimethylamine and epichlorohydrin, from the viewpoint of easily obtaining the above-mentioned additive effects related to the cationic compound. The reaction product of a starting material containing dimethylamine and epichlorohydrin may be a reaction product of a starting material containing at least dimethylamine, ammonia, and epichlorohydrin.

[0078] From the viewpoint of efficiently obtaining flatness such as suppressing dishing of pattern wafers, the content of cationic compounds may be within the following ranges based on the total mass of the polishing solution: The content of cationic compounds may be 0.0005% by mass or more, 0.0008% by mass or more, 0.001% by mass or more, 0.0012% by mass or more, 0.005% by mass or more, 0.01% by mass or more, 0.03% by mass or more, or 0.05% by mass or more. The content of cationic compounds may be 0.5% by mass or less, 0.3% by mass or less, 0.1% by mass or less, 0.08% by mass or less, or 0.05% by mass or less. From these viewpoints, the content of cationic compounds may be between 0.0005% and 0.5% by mass.

[0079] [Other additives] The additives in the polishing solution according to this embodiment may further contain other components (components not included in the above-mentioned components) to achieve desired properties. Examples of such components include pH adjusters (described later), polar solvents such as ethanol and acetone, and cyclic monocarboxylic acids.

[0080] The polishing solution according to this embodiment may contain compound a having a molecular weight of 100,000 or less and four or more hydroxyl groups, or it may not contain compound a. The content of compound a may be 0.01% by mass or less, less than 0.01% by mass, 0.001% by mass or less, 0.0001% by mass or less, or substantially 0% by mass, based on the total mass of the polishing solution. The polishing solution according to this embodiment may contain compound b having four or more amino groups, or it may not contain compound b. The content of compound b may be 0.001% by mass or less, less than 0.001% by mass, 0.0001% by mass or less, 0.00001% by mass or less, or substantially 0% by mass, based on the total mass of the polishing solution. 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.

[0081] (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.

[0082] (pH) The pH (at 25°C) of the polishing solution according to this embodiment may be within the following ranges. The pH is set from the viewpoint of easily suppressing the aggregation of abrasive grains, easily obtaining a high polishing rate for silicon oxide (for example, silicon oxide in the raised parts of a pattern wafer), easily suppressing the polishing rate of silicon nitride which can be used as a stopper material, and easily obtaining the effect of adding the above additives, and is set to 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, or 9.0 or less. The following are acceptable: less than 9.0, 8.5 or less, 8.0 or less, less than 8.0, 7.5 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, 5.3 or less, 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, 4.0 or less, less than 4.0, 3.8 or less, or 3.7 or less. The pH may be 3.0 or higher, 3.5 or higher, 3.7 or higher, 3.8 or higher, 4.0 or higher, greater than 4.0, 4.1 or higher, 4.2 or higher, 4.3 or higher, 4.4 or higher, 4.5 or higher, 4.6 or higher, 4.7 or higher, 4.8 or higher, 5.0 or higher, 5.1 or higher, 5.3 or higher, 5.5 or higher, greater than 5.5, 5.6 or higher, 6.0 or higher, greater than 6.0, 6.5 or higher, 7.0 or higher, or greater than 7.0, from the viewpoint of easily suppressing the silicon dioxide to be polished from having a large zeta potential on the positive side, similar to cerium-based particles (e.g., cerium oxide particles), and easily obtaining a high polishing rate for silicon dioxide on the convex parts of the pattern wafer. From these perspectives, 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. When the pH is 4.0 to 5.0, by using component (A) in combination with component (B1) or component (B2), it is particularly easy to obtain a high polishing speed on the convex parts of the pattern wafer. The polishing solution according to the first embodiment may be configured such that component (B1) contains ethylenedinitrilotetraethanol and the pH of the polishing solution is 8.0 or less. The pH can be measured by the method described in the examples.

[0083] By having a pH of 3.0 to 5.5, in addition to the above, the following two effects can also be expected. (1) Protons, hydroxy anions, etc., act on the compound added as an additive, changing the chemical form of the compound, which improves the wettability or affinity of the substrate surface to silicon dioxide, making it easier to obtain a high polishing rate. (2) When the abrasive grains contain a cerium-based compound (e.g., cerium oxide), the contact efficiency between the abrasive grains and silicon oxide is improved, making it easier to achieve a high polishing speed. This is because cerium-based compounds have a positive zeta potential, while silicon oxide has a negative zeta potential, and an electrostatic attraction acts between the two.

[0084] Since the pH can change 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 are no particular restrictions on the pH adjuster, but examples 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 and aminoacetic acid may also be used for pH adjustment. Furthermore, from the viewpoint of improving productivity, the polishing solution may be prepared without using a pH adjuster and this polishing solution may be applied directly to CMP.

[0085] <Method for preparing and using polishing solution> The polishing solutions according to this embodiment can be classified into (a) normal type, (b) concentrated type, and (c) multi-liquid type (e.g., two-liquid type; polishing solution set for CMP), and the preparation method and usage method differ depending on the type. (a) The normal type is a polishing solution that can be used as is without any pretreatment such as dilution during polishing. (b) The concentrated type is a polishing solution in which the contained components are concentrated compared to the normal type, taking into consideration the convenience of storage or transportation. (c) The multi-liquid type is a polishing solution in which the contained components are separated into multiple liquids during storage or transportation (for example, separated into a first liquid containing a certain component and a second liquid containing other components), and these liquids are mixed before use.

[0086] (a) The standard type can be obtained by dissolving or dispersing abrasive grains and additives in water, which is the main dispersion medium. For example, to prepare 1000g of polishing solution containing 0.5 parts by mass of abrasive grains and 0.1 parts by mass of additives per 100 parts by mass of polishing solution, the proportions of abrasive grains and additives should be adjusted so that the total amount of polishing solution is 5g and 1g.

[0087] Polishing solutions can be prepared using, for example, a stirrer, homogenizer, ultrasonic disperser, or wet ball mill. Furthermore, during the preparation of the polishing solution, a process to micronize the abrasive particles may be performed so that the average particle size of the abrasive particles falls within a desired range. This micronization process can be carried out by sedimentation classification or by using a high-pressure homogenizer. The sedimentation classification method involves forcibly settling a slurry containing abrasive particles using a centrifuge and then removing only the supernatant liquid. On the other hand, the high-pressure homogenizer method involves colliding abrasive particles in a dispersion medium under high pressure.

[0088] (b) The concentrated type is diluted with water immediately before use so that the components are in the desired amounts. After dilution, stirring may be carried out for any amount of time until liquid properties (pH, abrasive particle size, etc.) and polishing properties (polishing rate of silicon dioxide, polishing selectivity ratio of silicon dioxide to silicon nitride, etc.) similar to those of the (a) normal type are obtained. With such a (b) concentrated type, the volume decreases depending on the degree of concentration, so storage and transportation costs can be reduced.

[0089] 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, there is a tendency to obtain advantages in terms of storage and transportation compared to when it 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, there is a tendency to suppress the aggregation of abrasive grains compared to when it exceeds 40 times.

[0090] (c) The multi-liquid type has the advantage of avoiding aggregation of abrasive grains compared to (b) the concentrated type by appropriately separating each liquid (first liquid, second liquid, etc.). Here, the components to be contained in each liquid are arbitrary. (c) The multi-liquid type (CMP polishing liquid set) is a polishing liquid set for obtaining a polishing liquid by mixing the first liquid (slice) and the second liquid (additive liquid). (c) In the multi-liquid type, the components of the CMP polishing liquid are stored separately in the first liquid and the second liquid, the first liquid contains abrasive grains and water, and the second liquid contains at least one additive and water. (c) In the first embodiment of the multi-liquid type, the first liquid contains abrasive grains and water, and the second liquid contains component (A), at least one selected from the group consisting of component (B1) and component (B2), and water. (c) In a second multi-liquid type, the first liquid comprises abrasive grains, component (A), and water, and the second liquid comprises at least one selected from the group consisting of component (B1) and component (B2), and water. (c) In a third multi-liquid type, the first liquid comprises abrasive grains, component (A), component (B1), and water, and the second liquid comprises component (B2) and water. (c) In a fourth multi-liquid type, the first liquid comprises abrasive grains, at least one selected from the group consisting of component (B1) and component (B2), and water, and the second liquid comprises component (A) and water. (c) In a fifth embodiment of the multi-liquid type, the first liquid contains abrasive grains and water, and the second liquid contains a nitrogen-containing hydroxyalkyl compound (ethylenedinitrilotetraethanol, ethylenedinitrilotetrapropanol, etc.) and water. The first and second liquids may contain other components as needed. In this case, any acid or alkali may be added to the first liquid to adjust the pH in order to improve the dispersibility of the abrasive grains in the first liquid.

[0091] (c) Multi-liquid polishing solutions are useful when the combination of components tends to degrade relatively quickly due to abrasive aggregation, etc., when mixed. From the viewpoint of reducing storage and transportation costs, at least one of the liquids (first liquid, second liquid, etc.) may be concentrated. In this case, when using the polishing solution, each liquid should be mixed with water. The concentration ratio and pH of each liquid are arbitrary, and it is sufficient that the final mixture has liquid properties and polishing properties similar to (a) a normal type polishing solution.

[0092] <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 polishing liquid set described above. 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 polishing liquid set described above.

[0093] The polishing method according to this embodiment uses a polishing solution in which the content of each component, pH, etc., has been adjusted, and can planarize a substrate having a silicon oxide film on its surface using CMP technology. The polishing method according to this embodiment is suitable for polishing that requires high speed, high flatness, and low polishing scratches, such as polishing ILD films, and is suitable for applications that polish many ILD films in a short time. According to one aspect of the polishing method according to this embodiment, it is possible to efficiently obtain the effect of improving the polishing speed and in-plane uniformity of silicon oxide on a blanket wafer. According to one aspect of the polishing method according to this embodiment, because the polishing solution according to this embodiment is used, it is possible to suppress the aggregation of abrasive grains while achieving a sufficiently high polishing speed and reducing the occurrence of polishing scratches.

[0094] The polishing step may be a step of supplying the polishing liquid according to this embodiment between the substrate and the polishing member (a member for polishing, such as a polishing pad), and polishing the substrate with the polishing member. The polishing method according to this embodiment is suitable for polishing substrates having a silicon oxide film on their surface. Therefore, the surface to be polished may contain silicon oxide, and the polishing step may be a step of supplying the polishing liquid according to this embodiment between the silicon oxide film on the substrate having a silicon oxide film on its surface and the polishing member, and polishing the silicon oxide film with the polishing member.

[0095] The polishing method according to this embodiment may be such that the surface to be polished has an uneven pattern composed of convex portions (Line portions) and concave portions (Space portions), and the convex portions may contain silicon dioxide. The width of the convex portions in the uneven pattern may be 30 μm or less, or 20 μm or less. The width of the convex portions in the uneven pattern may be 10 μm or more, or 20 μm or more. The sum of the widths of the convex portions and concave portions in the uneven pattern may be 200 μm or less, or 100 μm or less. The sum of the widths of the convex portions and concave portions in the uneven pattern may be 80 μm or more, or 100 μm or more.

[0096] The polishing method according to this embodiment is suitable for polishing a substrate having a silicon oxide film on its surface during the manufacturing process of a device. Examples of devices 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 eraseable programmable read-only memory), and flash memory; theoretical 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 elements.

[0097] According to one embodiment of the polishing solution in this embodiment, a high polishing speed can be achieved without being heavily dependent on the uneven shape of the surface to be polished. Therefore, the polishing method using this polishing solution can be applied even to substrates for which it was difficult to achieve a high polishing speed using conventional polishing solutions.

[0098] The polishing method according to this embodiment is suitable for flattening surfaces that have steps (irregularities) on their surface. Examples of substrates having such surfaces include semiconductor devices for logic. Furthermore, the polishing method according to this embodiment is suitable for polishing surfaces that include portions where recesses or protrusions form a T-shape or grid shape when viewed from above. For example, the polishing method according to this embodiment can also polish silicon oxide films provided on the surface of semiconductor devices with memory cells (DRAM, flash memory, etc.) at a high speed. These are areas where it was difficult to achieve high polishing speeds using conventional CMP polishing solutions, demonstrating that one aspect of the polishing solution according to this embodiment can achieve high polishing speeds without being heavily dependent on the irregularity shape of the surface to be polished.

[0099] The substrate is not limited to a substrate having only a silicon oxide film on its surface, but may also have a silicon nitride film, a polycrystalline silicon film, or the like on its surface in addition to the silicon oxide film. The substrate may also have an inorganic insulating film such as silicon oxide, glass, or silicon nitride on a wiring board having predetermined wiring; or a film mainly containing polysilicon, Al, Cu, Ti, TiN, W, Ta, TaN, etc.

[0100] Below, as an example of a process including the polishing method according to this embodiment, a process for forming an ILD film (interlayer insulating film) structure by CMP will be described. Figure 1 is a schematic cross-sectional view showing the process of polishing the ILD film, illustrating the process of forming the ILD film between wirings. Figure 1(a) is a schematic cross-sectional view showing the substrate before polishing. Figure 1(b) is a schematic cross-sectional view showing the substrate after polishing.

[0101] As shown in Figure 1(a), in the substrate 100 before polishing, wiring 20 is formed on a lower substrate (not shown) having predetermined lower wiring (not shown) via an ILD film 10, and a silicon oxide film 30 is formed 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 on 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 to penetrate the ILD film 10.

[0102] In the process of forming the ILD film structure, in order to eliminate the step difference D, partially protruding unnecessary parts 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 the polishing member so that the surface of the silicon oxide film 30 and the polishing member come into contact, and the surface of the silicon oxide film 30 is polished with this polishing member. More specifically, the side of the silicon oxide film 30 to be polished (surface) is pressed against the polishing member of the polishing platen, and the silicon oxide film 30 is polished by moving the two relative to each other while supplying polishing fluid between the surface to be polished and the polishing member. As a result, the step difference D is eliminated, and finally, as shown in Figure 1(b), the height of the wiring 20 portion on the surface of the silicon oxide film 30 and the height of the other portions become approximately the same, and a substrate 100a having a silicon oxide film 30 (ILD film) with a flat surface is obtained.

[0103] As a polishing apparatus used for polishing, for example, an apparatus comprising a holder for holding a substrate, a polishing platen to which a polishing pad is attached, and means for supplying polishing fluid onto the polishing pad can be used. Examples of polishing apparatuses include those manufactured by Ebara Corporation (model numbers: EPO-111, EPO-222, F-REX200 and F-REX300) and those manufactured by Applied Material (product names: Mirra3400 and Reflexion). There are no particular restrictions on the materials used to construct the polishing pad; for example, general nonwoven fabrics, foamed polyurethanes, porous fluororesins, etc., can be used. The polishing pad may also be grooved to allow polishing fluid to accumulate.

[0104] There are no particular restrictions on the polishing conditions, but to prevent the substrate from flying off, the rotation speed of the polishing platen should be 200 min⁻¹. -1 The following may apply: The pressure (processing load) applied to the substrate may be 100 kPa or less, from the viewpoint of easily suppressing polishing scratches on the polished surface. During polishing, polishing fluid may be continuously supplied to the polishing pad by a pump or the like. There is no limit to the amount supplied, but the surface of the polishing pad may always be covered with polishing fluid. After polishing is completed, the substrate may be thoroughly washed in running water, and then dried after removing any water droplets adhering to the substrate using a spin dryer or the like.

[0105] By polishing as described above, surface irregularities can be eliminated, and a smooth surface can be obtained over the entire substrate. Furthermore, by repeating the process of forming the film and polishing this film a predetermined number of times, a structure having a desired number of layers can be manufactured.

[0106] The substrates (structures) obtained in this way can be used as various electronic components. Specific examples of electronic components include semiconductor elements; optical glass such as photomasks, lenses, and prisms; inorganic conductive films such as ITO; optical integrated circuits, optical switching elements, and optical waveguides composed 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.

[0107] <Manufacturing method etc.> The method for manufacturing a component according to this embodiment includes a component manufacturing step of obtaining a component using a substrate (a member to be polished) polished by the polishing method according to this embodiment. The component according to this embodiment is a component obtained by the method for manufacturing a component according to this embodiment. The component according to this embodiment is not particularly limited, but may be an electronic component (for example, a semiconductor component such as a semiconductor package), a wafer (for example, a semiconductor wafer), or a chip (for example, a semiconductor chip). As one embodiment of the method for manufacturing a component according to this embodiment, the method for manufacturing an electronic component according to this embodiment obtains an electronic component using a substrate polished by the polishing method according to this embodiment. As one embodiment of the method for manufacturing a component according to this embodiment, the method for manufacturing a semiconductor component according to this embodiment obtains a semiconductor component (for example, a semiconductor package) using a substrate polished by the polishing method according to this embodiment. The method for manufacturing a component according to this embodiment may include a polishing step of polishing the substrate by the polishing method according to this embodiment before the component manufacturing step.

[0108] The method for manufacturing a component according to this embodiment may include, as one aspect of the component manufacturing process, a piece-forming step of dividing the substrate (member to be polished) polished by the polishing method according to this embodiment into individual pieces. The piece-forming step may be, for example, a step of dicing a wafer (e.g., a semiconductor wafer) polished by the polishing method according to this embodiment to obtain a chip (e.g., a semiconductor chip). As one aspect of the method for manufacturing a component according to this embodiment, the method for manufacturing an electronic component according to this embodiment may include a step of obtaining an electronic component (e.g., a semiconductor component) by dividing the substrate polished by the polishing method according to this embodiment into individual pieces. As one aspect of the method for manufacturing a component according to this embodiment, the method for manufacturing a semiconductor component according to this embodiment may include a step of obtaining a semiconductor component (e.g., a semiconductor package) by dividing the substrate polished by the polishing method according to this embodiment into individual pieces.

[0109] The method for manufacturing a part according to this embodiment may include, as one aspect of the part manufacturing process, a connection step of connecting (for example, electrically connecting) a substrate (a member to be polished) polished by the polishing method according to this embodiment to another connected body. The connected body connected to the substrate polished by the polishing method according to this embodiment is not particularly limited and may be the substrate polished by the polishing method according to this embodiment, or it may be a connected body different from the substrate polished by the polishing method according to this embodiment. In the connection step, the substrate and the connected body may be directly connected (connected in a state where the substrate and the connected body are in contact), or they may be connected via another member (such as a conductive member). The connection step can be performed before the individualization step, after the individualization step, or before and after the individualization step.

[0110] The connection step may be a step of connecting the polished surface of a substrate polished by the polishing method according to this embodiment with the connected body, or a step of connecting the connecting surface of a substrate polished by the polishing method according to this embodiment with the connecting surface of the connected body. The connecting surface of the substrate may be the polished surface polished by the polishing method according to this embodiment. A connected body comprising a substrate and a connected body can be obtained by the connection step. In the connection step, if the connecting surface of the substrate has a metal part, the connected body may be brought into contact with the metal part. In the connection step, if both the connecting surface of the substrate and the connecting surface of the connected body have metal parts, the metal parts may be brought into contact with each other. The metal part may contain copper.

[0111] The device according to this embodiment (for example, an electronic device such as a semiconductor device) comprises a substrate polished by the polishing method according to this embodiment, and at least one selected from the group consisting of components according to this embodiment. [Examples]

[0112] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0113] <Preparation of cerium oxide powder> 40 kg of cerium carbonate hydrate was divided into 10 alumina containers and calcined in air at 830°C for 2 hours to obtain a total of 20 kg of yellowish-white powder. Phase identification of this powder was performed by X-ray diffraction, confirming that it contained polycrystalline cerium oxide. SEM observation of the powder obtained by calcination revealed a particle size range of 20–100 μm. Next, 20 kg of the cerium oxide powder was dry-milled using a jet mill to obtain cerium oxide powder. The specific surface area of ​​the cerium oxide powder after milling was 9.4 m². 2 The value was / g. Specific surface area was measured using the BET method.

[0114] <Preparation of slurry> 15.0 kg of cerium oxide powder and 84.5 kg of deionized water obtained above were placed in a container and mixed. Next, 0.5 kg of 1 M (mol / L, approximately 6 mass%) acetic acid was added, and the mixture was stirred for 10 minutes to obtain a cerium oxide mixture. This cerium oxide mixture was transferred to another container over 30 minutes. During this time, the cerium oxide mixture was irradiated with ultrasound at an ultrasonic frequency of 400 kHz in the piping through which it was being transferred.

[0115] The aforementioned cerium oxide mixture, delivered after ultrasonic irradiation, was placed into four 500 mL polyethylene containers, each containing 500 g ± 5 g of the mixture. The cerium oxide mixture in each container was centrifuged for 2 minutes under conditions where the centrifugal force acting on the outer circumference was 500 G. After centrifugation, the supernatant fraction was collected from the containers to obtain a slurry. The slurry contained approximately 6.0% by mass of cerium oxide particles (abrasive grain A) based on total mass.

[0116] The cerium oxide mixture described above, which had been delivered after ultrasonic irradiation, was placed into four 500 mL polyethylene containers, each containing 500 g ± 5 g of the mixture. The cerium oxide mixture in each container was centrifuged for 5 minutes under conditions where the centrifugal force acting on the outer circumference was 1200 G. After centrifugation, the supernatant fraction was collected from the containers to obtain a slurry. The slurry contained approximately 2.0% by mass of cerium oxide particles (abrasive grain B) based on the total mass.

[0117] The slurry was diluted with pure water so that the abrasive grain content became 0.25% by mass on a total mass basis to obtain a sample for particle size measurement. 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). As a result, the average particle size of abrasive grain A was 140 nm, and the average particle size of abrasive grain B was 120 nm.

[0118] <Preparation of CMP Polishing Liquid> By mixing the above slurry, each additive, and deionized water according to the following procedure, polishing liquids having the compositions shown in the following tables (balance: deionized water) were obtained. In the tables, "THEED" means 2,2’,2’’,2’’’-ethylenedinitrilotetraethanol, and "EDTP" means 1,1’,1’’,1’’’-ethylenedinitrilotetra-2-propanol. Abrasive grain A was used in the examples except for Examples 3 and 8, and abrasive grain B was used in Examples 3 and 8. Each polishing liquid contains acetic acid in a content corresponding to the respective abrasive grain content as the acetic acid mixed during the preparation of the above slurry. Note that the pH of a 1 mM aqueous solution of acetic acid is less than 5.0.

[0119] 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 on a total mass basis. The storage liquid for the polishing liquid contains 20 times the amount of abrasive grains and additives with respect to the final abrasive grain content of 0.25% by mass of the polishing liquid, and contains 5 times the amount of abrasive grains and additives with respect to the final abrasive grain content of 1.00% by mass of the polishing liquid.

[0120] <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.

[0121] Then, by diluting the storage liquid for the polishing liquid 20-fold with deionized water, polishing liquids of the examples except for Examples 6, 9, 10, 31 to 35, and 38, and polishing liquids of the comparative examples were obtained. Further, by diluting the storage liquid for the polishing liquid 5-fold with deionized water, polishing liquids of Examples 6, 9, 10, 31 to 35, and 38 were obtained. For the polishing liquids of each example, when the abrasive grain content was 0.25% by mass on a total mass basis (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 diameter of the abrasive grains was equivalent to the average particle diameter of the abrasive grains in the above-described slurry.

[0122] <pH Measurement> (pH of the polishing liquid) The pH of the polishing liquid was measured under the following conditions. The results are shown in each table. Measurement temperature: 25°C Measurement device: Trade name: Model (D-71) of Horiba, Ltd. Measurement method: After performing three-point calibration of the pH meter using phthalate pH standard solution (pH: 4.01), neutral phosphate pH standard solution (pH: 6.86), and borate pH standard solution (pH: 9.18) as pH standard solutions, the electrode of the pH meter was placed in the polishing liquid, and after 2 minutes or more had elapsed and it had stabilized, the pH was measured using the above-described measurement device.

[0123] (pH of the 1 mM solution of Additive B1) A 1 mM (millimolar concentration) solution was prepared by dissolving Additive B1 in the table in deionized water. The pH of the solution was measured in the same procedure as the pH of the polishing liquid. The results are shown in each table.

[0124] <Evaluation of Polishing Characteristics> (Preparation of wafers for evaluation) As blank wafers (BKW), a φ200 mm unpatterned wafer having a silicon oxide film (SiO2, initial film thickness: 1000 nm) on the surface and a φ200 mm unpatterned wafer having a silicon nitride film (SiN, initial film thickness: 200 nm) on the surface were prepared.

[0125] As a pattern wafer (PTW), a wafer with a test pattern (model number: Sematech864, manufactured by Advantech Co., Ltd., φ200mm) with a silicon oxide film (initial film thickness: 600nm) having a surface uneven pattern was prepared. The raised areas (Line areas) have an initial step height 500nm higher than the recessed areas (Space areas), and the raised areas are equipped with a silicon nitride film (initial film thickness: 140nm) as a stopper under the silicon oxide film, anticipating evaluation for shallow trench isolation. The pattern wafer has multiple 20mm × 20mm die units, and within each die unit there are multiple 4mm × 4mm unit areas. The pattern wafer has regions in the 4mm × 4mm unit areas that have a pitch width of 100μm and a Line / Space (L / S) of 10μm increments of 10μm / 90μm (density of raised areas: 10%) to 90μm / 10μm (density of raised areas: 90%) with parallel line patterns. The pattern wafer has a 4mm x 4mm area, which consists of a 4mm x 4mm square pattern of raised areas (density of raised areas: 100%) and a 4mm x 4mm square pattern of recessed areas (density of raised areas: 0%).

[0126] (Polishing procedure) The evaluation wafers described above were polished using a polishing device (Applied Material, product name: Mirra3400). The evaluation wafers were set in a holder equipped with a suction pad for substrate attachment. A porous urethane resin polishing pad (K-groove groove, DuPont (Dow), model number: IC-1010) was attached to a 500 mm diameter polishing platen.

[0127] The aforementioned evaluation wafer was placed with the polishing surface facing downwards, and the aforementioned holder was placed on the polishing pad. The inner tube pressure, retainer ring pressure, and membrane pressure were set to 14kPa, 21kPa, and 14kPa, respectively.

[0128] Then, while dripping the aforementioned polishing solution onto the polishing pad attached to the aforementioned polishing platen at a flow rate of 200 mL / min, the polishing platen and the evaluation wafer were each polished for 93 minutes. -1 and 87min-1 The surface to be polished was polished by rotating it. For blanket wafers, polishing was performed for 30 seconds. For pattern wafers, the polishing time was set to a range of 20 to 60 seconds, depending on the polishing speed evaluated for blanket wafers, and the time during which the silicon nitride film underlying the silicon oxide film was not exposed in the convex areas of the L / S = 20 μm / 80 μm region was set, and polishing was performed for that polishing time. Subsequently, the evaluation wafers after polishing were thoroughly washed with pure water using a PVA brush (polyvinyl alcohol brush) and then dried.

[0129] (Evaluation of polishing speed) The change in film thickness of the film to be polished before and after polishing was measured using an optical interferometry film thickness analyzer (manufactured by Nanometrics Japan Co., Ltd., product name: AFT-5100) as described below, and the polishing speed was obtained. The results are shown in the respective tables.

[0130] For the blanket wafer, the change in film thickness was measured at a total of 41 measurement points: the center point of the wafer and points at 5 mm intervals in the diametrical direction from the center point (20 points on each side of the center point). (For example, the next measurement point after the one 95 mm from the center was set at 97 mm from the center.) The change in film thickness was measured at these 41 points during a 30-second polishing time, and the average value was obtained as the polishing speed of the blanket wafer.

[0131] On the patterned wafer, the change in film thickness was measured in the convex areas of the L / S = 20 μm / 80 μm region, the convex areas of the L / S = 30 μm / 70 μm region, the square-shaped convex pattern (convex density: 100%), and the square-shaped concave pattern (convex density: 0%) to obtain the polishing speed of the patterned wafer. In the central die unit (20 mm × 20 mm) of the patterned wafer, the change in film thickness was measured at one point in the center of one unit area (4 mm × 4 mm) of the target pattern.

[0132] [Table 1]

[0133] [Table 2]

[0134] [Table 3]

[0135] [Table 4]

[0136] [Table 5]

[0137] [Table 6]

[0138] [Table 7]

[0139] [Table 8]

[0140] Although the relationship between the polishing rates of silicon dioxide in the convex portions (line portions) in the L / S = 20 μm / 80 μm region differs from the relationship between the polishing rates of silicon dioxide in the blanket wafer, it was confirmed that in all examples, a high polishing rate of silicon dioxide in the convex portions (e.g., ≥300 nm / min) was obtained in the L / S = 20 μm / 80 μm region while simultaneously achieving a high polishing rate of silicon dioxide in the convex portions in the L / S = 20 μm / 80 μm region.

[0141] In some of the examples, a sufficiently low polishing rate of silicon nitride on the blanket wafer (e.g., <2.0 nm / min) has been achieved, and in some cases, a particularly low polishing rate of silicon nitride (e.g., <1.0 nm / min) has been achieved. In all of the examples, a high polishing speed was obtained for the convex portion (line portion) in the L / S = 30 μm / 70 μm region. The polishing speed at which the protrusions are 0% is an indicator of the dishing characteristics, and in some of the examples, a sufficiently small polishing speed (e.g., ≤300 nm / min) has been obtained. The polishing speed ratio of 100% convex / 0% convex is an indicator of planarization efficiency, and in some examples, a favorable polishing speed ratio (e.g., >1.0) has been obtained.

[0142] The inventors describe in the specification the best mode for carrying out this disclosure. If a peer were to read the above description, similar variations might become apparent. The inventors are fully aware of the different forms of carrying out this disclosure, as well as similar forms that apply the core principles of this disclosure. Furthermore, in principle, all variations of the contents listed in the specification, and any various combinations of the above elements, are available in this disclosure. All possible combinations are included in this disclosure unless specifically limited herein or explicitly rejected by the context. [Explanation of symbols]

[0143] 10...ILD film, 20...wiring, 30...silicon oxide film, 40...contact plug, 100,100a...substrate, D...step.

Claims

1. It contains abrasive particles, additives, and water. The abrasive grains include cerium-based particles, The average particle size of the abrasive grains exceeds 100 nm. The additive comprises (A) a 4-pyrone compound represented by the following general formula (1), and (B2) a cyclic compound having at least one functional group selected from the group consisting of a carboxyl group, a carboxylic acid base, an amino group, and a hydroxyl group. The mass ratio of the content of component (B2) to the content of component (A) is 0.1 to 10. A polishing solution for CMP with a pH of 4.8 or lower. 【Chemistry 1】 [In the formula, X １１ , X １２ and X １３ Each of these is independently either a hydrogen atom or a monovalent substituent.

2. A product comprising abrasive grains, an additive, and water, The abrasive grains include cerium-based particles, The average particle size of the abrasive grains exceeds 100 nm. The additive comprises (A) a 4-pyrone compound represented by the following general formula (1), and (B2) a cyclic compound having at least one functional group selected from the group consisting of a carboxyl group, a carboxylic acid base, an amino group, and a hydroxyl group. The aforementioned component (B2) comprises at least one selected from the group consisting of anthranilic acid and its salts, A polishing solution for CMP, wherein the mass ratio of the content of component (B2) to the content of component (A) is 0.1 to 10. 【Chemistry 2】 [In the formula, X11, X12, and X13 are each independently a hydrogen atom or a monovalent substituent.]

3. A product comprising abrasive grains, an additive, and water, The abrasive grains include cerium-based particles, The average particle size of the abrasive grains exceeds 100 nm. The additive comprises (A) a 4-pyrone compound represented by the following general formula (1), (B2) a cyclic compound having at least one functional group selected from the group consisting of a carboxyl group, a carboxylic acid base, an amino group, and a hydroxyl group, and a saturated monocarboxylic acid. The mass ratio of the content of component (B2) to the content of component (A) is 0.1 to 10. A polishing solution for CMP, wherein the content of the saturated monocarboxylic acid is 0.0001 to 5% by mass. 【Transformation 3】 [In the formula, X11, X12, and X13 are each independently a hydrogen atom or a monovalent substituent.]

4. The polishing solution for CMP according to claim 1 or 3, wherein the (B2) component comprises at least one selected from the group consisting of aromatic aminocarboxylic acids, quinoline carboxylic acids, pyridinecarboxylic acids, and salts thereof.

5. The polishing solution for CMP according to any one of claims 1 to 3, wherein the (B2) component comprises at least one selected from the group consisting of quinaldic acid and salts thereof.

6. The CMP polishing solution according to claim 1 or 3, wherein the (B2) component comprises at least one selected from the group consisting of anthranilic acid and its salts.

7. The polishing solution for CMP according to any one of claims 1 to 3, wherein the (B2) component comprises at least one selected from the group consisting of picolinic acid and salts thereof.

8. The polishing solution for CMP according to any one of claims 1 to 3, wherein the content of component (B2) is 0.001 to 5% by mass.

9. The polishing solution for CMP according to any one of claims 1 to 3, wherein the cerium-based particles contain cerium oxide.

10. The polishing liquid for CMP according to any one of claims 1 to 3, wherein the content of the abrasive grains is 0.01 to 10% by mass.

11. The CMP polishing solution according to any one of claims 1 to 3, wherein the component (A) comprises at least one 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.

12. The polishing solution for CMP according to any one of claims 1 to 3, wherein the content of component (A) is 0.001 to 5% by mass.

13. The polishing solution for CMP according to claim 1 or 2, further comprising a saturated monocarboxylic acid as the additive.

14. The polishing solution for CMP according to claim 13, wherein the content of the saturated monocarboxylic acid is 0.0001 to 5% by mass.

15. A CMP polishing liquid set in which the components of the CMP polishing liquid according to any one of claims 1 to 3 are stored separately in a first liquid and a second liquid, the first liquid comprising the abrasive grains and water, and the second liquid comprising at least one of the additives and water.

16. A polishing method comprising the step of polishing a surface to be polished using a polishing liquid for CMP described in any one of claims 1 to 3.

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

18. A polishing method comprising the step of polishing a surface to be polished using a CMP polishing solution obtained by mixing the first liquid and the second liquid in the CMP polishing solution set described in claim 15.

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

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