CMP polishing slurry, CMP polishing slurry kit and polishing method

Abstract

A CMP polishing slurry contains abrasive particles, an additive, and water. The abrasive particles comprise cerium-based particles. The additive comprises: (A) a 4-pyranone compound represented by the following general formula (1); and a cyclic compound having (B1) a compound with a pH of 3.7 or higher in a 1 mM aqueous solution, or (B2) at least one functional group selected from the group consisting of carboxyl, carboxyl, amino, and hydroxyl groups. The CMP polishing slurry contains abrasive particles, an additive, and water. The abrasive particles comprise cerium-based particles. The additive comprises a compound having two or more nitrogen atoms bonded to a hydroxyl alkyl group. [In the formula, X11, X12, and X13 independently represent a hydrogen atom or a monovalent substituent.]

Description

[Technical Field]

[0001] This disclosure relates to a CMP (chemical mechanical polishing) polishing slurry, a CMP polishing slurry kit, a polishing method, etc. [Previous Technology]

[0002] In the semiconductor manufacturing field, with the increasing performance of Very Large Scale Integration (VLSI) devices, there are limitations in balancing high integration and high speed using miniaturization techniques, which are extensions of previous technologies. Therefore, while promoting the miniaturization of semiconductor devices, technologies that also achieve high integration in the vertical direction (i.e., multilayer wiring technology) are being developed.

[0003] In the manufacturing process of devices with multilayered wiring, CMP technology is one of the most important technologies. CMP technology is a technique for planarizing the surface of a substrate obtained by forming a thin film on a substrate through chemical vapor deposition (CVD) or similar methods. For example, CMP-based planarization is indispensable to ensure the depth of focus in lithography. If the surface of the substrate is uneven, it will cause inconveniences such as inability to focus during the exposure step and inability to fully form the micro-wiring structure. Furthermore, in the device manufacturing process, CMP technology is also applicable to steps such as forming component separation (inter-component separation, STI: shallow trench isolation) areas 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.) in the same layer from each other); and planarizing steps such as embedding a silicon oxide film into the metal wiring and then plugging it (e.g., Al·Cu plugging).

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

[0005] In the CMP process described above, especially in the CMP process of ILD films, it is necessary to grind silicon oxide at a high grinding speed. Therefore, in the CMP process of ILD films, silicon dioxide-based polishing slurries with high polishing speeds (polishing slurries using abrasive grains containing silicon dioxide particles) are mainly used (for example, see Patent Document 2 below). However, in silicon dioxide-based polishing slurries, it is difficult to control polishing scratches, which are a cause of defects. Furthermore, although it is desirable to reduce polishing scratches in the CMP process of ILD films with the miniaturization of wiring in recent years, unlike the CMP process of insulating films for component separation areas, mirror polishing is generally not performed. Therefore, a cerium-based polishing slurry (polishing slurry using abrasive grains containing cerium particles) that produces fewer polishing scratches than silicon dioxide-based polishing slurries has been investigated (for example, see Patent Document 3 below).

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2008-288537 [Patent Document 2] Japanese Patent Application Publication No. Hei 9-316431 [Patent Document 3] Japanese Patent Application Publication No. Hei 10-102038

[0007] However, it is sometimes difficult to achieve high grinding speeds for silicon oxide in cerium-based polishing slurries. In particular, it is sometimes difficult to achieve high grinding speeds for silicon oxide with convex parts in the polishing process of patterned wafers having fine convex and concave patterns composed of protrusions (e.g., line portions) and concave parts (e.g., space portions). [Summary of the Invention]

[0008] One aspect of this disclosure is to provide a CMP polishing slurry that achieves a high polishing speed for the silicon oxide on the raised portions during the polishing process of a patterned wafer with fine raised and recessed patterns. Another aspect of this disclosure is to provide a CMP polishing slurry kit for obtaining the aforementioned CMP polishing slurry. Furthermore, another aspect of this disclosure is to provide the aforementioned CMP polishing slurry or a polishing method using the aforementioned CMP polishing slurry kit.

[0009] Several aspects disclosed herein relate to the following [1] to

[25] etc. [1] A CMP polishing slurry containing abrasive particles, additives and water, wherein the abrasive particles comprise cerium-based particles, and the additives comprise (A) a 4-pyranone compound represented by the following general formula (1) and (B1) a compound having a pH of 3.7 or higher in a 1 mM aqueous solution. [Chemical 1] [wherein, X11, X12 and X13 each independently represent a hydrogen atom or a monovalent substituent.] [2] The CMP polishing slurry as described in [1], wherein the aforementioned component (B1) comprises at least one selected from the group consisting of basic amino acids, aromatic amino acids, aminoacetic acids, hydroxypyridine, methylpyridine, acetylopyridine, pyridineethanol, aminopyridine, imidazole, pyrazole, triazole, ethylenediaminetetraethanol, ethylenediaminetetrapropanol and triethanolamine. [3] The CMP polishing slurry as described in [1], wherein the aforementioned component (B1) comprises hydroxypyridine. [4] The CMP polishing slurry as described in [1], wherein the aforementioned component (B1) comprises ethylenediaminetetraethanol. [5] The CMP polishing slurry as described in [4], wherein the pH of the CMP polishing slurry is below 8.0. [6] The CMP polishing slurry as described in [1], wherein the aforementioned component (B1) comprises triethanolamine. [7] The CMP polishing slurry as described in any one of [1] to [6], wherein the content of the aforementioned component (B1) is 0.001 to 5% by mass. [8] A CMP polishing slurry comprising abrasive particles, an additive and water, wherein the abrasive particles comprise cerium-based particles, and the additive comprises (A) a 4-pyranone 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 carboxyl group, an amino group and a hydroxyl group. [Chem. 2] [In the formula, X 11, X 12 and X 13 each independently represent a hydrogen atom or a monovalent substituent.] [9] The CMP polishing slurry as described in [8], wherein the average particle size of the aforementioned polishing particles exceeds 100 nm.

[10] The CMP polishing slurry as described in [8] or [9], wherein the aforementioned component (B2) comprises at least one selected from the group consisting of aromatic aminocarboxylic acids, quinolinecarboxylic acids, pyridinecarboxylic acids and their salts.

[11] The CMP polishing slurry as described in any one of [8] to

[10] , wherein the aforementioned component (B2) comprises at least one selected from the group consisting of quinacrine and its salts.

[12] The CMP polishing slurry as described in any one of [8] to

[11] , wherein the aforementioned component (B2) comprises at least one selected from the group consisting of anthraquinone and its salts.

[13] The CMP polishing slurry as described in any one of [8] to

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

[14] The CMP polishing slurry as described in any one of [8] to

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

[15] A CMP polishing slurry comprising abrasive particles, an additive, and water, wherein the abrasive particles comprise cerium-based particles, and the additive comprises a compound having two or more nitrogen atoms bonded to a hydroxyl alkyl group.

[16] The CMP polishing slurry of

[15] wherein the compound having two or more nitrogen atoms bonded to the aforementioned hydroxyl alkyl group comprises ethylenediaminetetraethanol.

[17] The CMP polishing slurry of

[15] or

[16] wherein the pH of the CMP polishing slurry is 8.0 or below.

[18] The CMP polishing slurry of any one of [1] to

[17] wherein the aforementioned cerium-based particles comprise cerium oxide.

[19] The CMP polishing slurry of any one of [1] to

[18] wherein the content of the aforementioned abrasive particles is 0.01 to 10% by mass.

[20] A polishing slurry for CMP as described in any one of [1] to

[19] , wherein the aforementioned component (A) comprises at least one selected from the group consisting of 3-hydroxy-2-methyl-4-pyranone, 5-hydroxy-2-(hydroxymethyl)-4-pyranone and 2-ethyl-3-hydroxy-4-pyranone.

[21] A polishing slurry for CMP as described in any one of [1] to

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

[22] A polishing slurry for CMP as described in any one of [1] to

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

[23] A polishing slurry for CMP as described in

[22] , wherein the content of the aforementioned saturated monocarboxylic acid is 0.0001 to 5% by mass.

[24] A CMP polishing slurry kit, wherein the components of the CMP polishing slurry described in any one of [1] to

[23] are stored in a first liquid and a second liquid, wherein the first liquid contains the aforementioned abrasive particles and water, and the second liquid contains at least one of the aforementioned additives and water.

[25] A polishing method comprising the step of polishing a surface to be polished using a CMP polishing slurry obtained by mixing the aforementioned first liquid and the aforementioned second liquid in the CMP polishing slurry kit described in any one of [1] to

[23] or the CMP polishing slurry kit described in

[24] .

[26] The polishing method described in

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

[0010] According to one aspect of this disclosure, a CMP polishing slurry can be provided, which can achieve a high polishing speed of silicon oxide on the raised portions in the polishing of patterned wafers with fine bump patterns. Furthermore, according to another aspect of this disclosure, a CMP polishing slurry kit for obtaining the aforementioned CMP polishing slurry can be provided. Additionally, according to another aspect of this disclosure, a polishing method using the aforementioned CMP polishing slurry or the aforementioned CMP polishing slurry kit can be provided.

Implementation Method

[0012] The following describes the implementation of this disclosure in detail.

[0013] In this specification, the numerical range represented by "~" indicates the range encompassed by the values ​​recorded before and after "~" as the minimum and maximum values, respectively. "Above A" in the numerical range refers to A and the range exceeding A. "Below A" in the numerical range refers to A and the range less than A. In the numerical ranges described in stages in this specification, the upper or lower limit of a certain stage's numerical range can be arbitrarily combined with the upper or lower limit of another stage's numerical range. In the numerical ranges described in this specification, the upper or lower limit can be replaced with the values ​​shown in the embodiments. "A or B" may include either A or B, or both. Unless otherwise specified, the materials exemplified in this specification can be used individually or in combination of two or more. In the case where a plurality of substances equivalent to each component exist in the composition, unless otherwise specified, the content of each component in the composition represents the total amount of the plurality of substances present in the composition. When viewed from above, the term "layer" or "film" includes structures formed on a portion of a surface, in addition to structures that form a shape on the entire surface. The term "step" is included not only as an independent step, but also as long as its intended function is achieved, even if it cannot be clearly distinguished from other steps. "(meth)acrylate" refers to at least one of acrylates and their corresponding methacrylates. The same applies to other similar expressions such as "(meth)acrylic acid".

[0014] <CMP Polishing Fluid> The CMP polishing fluid of this embodiment (first embodiment, second embodiment and third embodiment, hereinafter the same) is a CMP polishing fluid containing abrasive particles, additives and water (hereinafter, as appropriate, simply referred to as "polishing fluid"). The abrasive particles contain cerium-based particles (particles containing cerium-based compounds). The additive of the polishing fluid of the first embodiment contains (A) a 4-pyranone compound represented by the following general formula (1) (component (A)) and (B1) a compound with a pH of 3.7 or higher in an aqueous solution of 1 mM (millimole concentration) (component (B1)). The additive of the polishing fluid of the second embodiment contains (A) a 4-pyranone compound represented by the following general formula (1) (component (A)) and (B2) a cyclic compound having at least one functional group selected from the group consisting of carboxyl, carboxylate, amino and hydroxyl groups (hydroxyl) (component (B2)). The grinding fluid additive of the third embodiment includes a compound having two or more nitrogen atoms bonded to a hydroxyalkyl group (hereinafter, as appropriate, referred to as a "nitrogen-containing hydroxyalkyl compound"; ethylenediaminetetraethanol, ethylenediaminetetrapropanol, etc.). The nitrogen-containing hydroxyalkyl compound can be any of the compounds equivalent to component (B1) and compounds not equivalent to component (B1), and ethylenediaminetetraethanol and ethylenediaminetetrapropanol are compounds equivalent to component (B1). The grinding fluid additive of this embodiment may include component (A), component (B1), and component (B2).

[0015] [Chemical 3] [In the formula, X 11, X 12 and X 13 independently represent a hydrogen atom or a monovalent substituent.]

[0016] According to the polishing slurry of this embodiment, when polishing a patterned wafer having a fine pattern of raised and recessed parts (e.g., line parts) and recessed parts (e.g., space parts), a high polishing speed of silicon oxide on the raised parts can be achieved. For example, when polishing the Line / Space (L / S) = 20μm / 80μm ​​region in the patterned wafer, a high polishing speed of silicon oxide on the raised parts can be achieved. (According to the polishing slurry of this embodiment, in the evaluation method described in the following embodiments, the polishing speed of silicon oxide on the raised parts in the L / S = 20μm / 80μm ​​region can be, for example, 300nm / min or more.)

[0017] Although the main reason for this effect is not yet clear, it is speculated to be as follows. The main reason is not limited to the following. That is, the interaction between the polishing slurry and silicon oxide is increased by using component (A), and the interaction between the polishing slurry and silicon oxide is also increased by using component (B1) or component (B2). However, when using component (A) without using components (B1) and (B2), and when using component (B1) or component (B2) other than nitrogen-containing hydroxyalkyl compounds (ethylenediaminetetraethanol, ethylenediaminetetrapropanol, etc.) without using component (A), it was confirmed that even if high-speed grinding of silicon oxide in control wafers without raised or recessed patterns is achieved by using cerium-based particles with a lower hardness than silicon dioxide-based particles, high grinding speed of silicon oxide in the raised parts of patterned wafers cannot be achieved. In particular, when grinding the L / S=20μm / 80μm ​​region in patterned wafers, a special phenomenon is that high grinding speed of silicon oxide in the raised parts cannot be achieved. On the other hand, according to the polishing slurries of the first and second embodiments, the interaction between the polishing slurry and the silicon oxide of the protrusion is increased due to the synergistic effect caused by the use of components (A) and (B1) or (B2) (for example, the chemical reaction between cerium particles in the polishing slurry and the silicon oxide of the protrusion (reaction from Si-O-Ce bonds) is promoted), thereby achieving a high polishing speed for the silicon oxide of the protrusion. This high polishing speed can be achieved in the L / S = 20μm / 80μm ​​region of the patterned wafer. Furthermore, according to the polishing slurry of the third embodiment, even without using component (A), the same effect can be obtained by using nitrogen-containing hydroxyalkyl compounds (ethylenediaminetetraethanol, ethylenediaminetetrapropanol, etc.).

[0018] According to the polishing slurry of this embodiment, high-speed polishing of silicon oxide in a control wafer without a raised or recessed pattern can be achieved (e.g., polishing speed of 100 nm / min or more (preferably 250 nm / min or more)), and high polishing speed of silicon oxide in the raised portion of the patterned wafer when polishing the L / S=20 μm / 80 μm region can be achieved.

[0019] Based on the polishing slurry of this embodiment, a high polishing speed of silicon oxide on the protrusions in the L / S=30μm / 70μm region of the polishing pattern wafer can also be achieved.

[0020] According to one aspect of the polishing slurry of this embodiment, even when using small-diameter polishing particles or when the content of polishing particles is low, it is possible to obtain a high polishing speed of silicon oxide on the protrusions when polishing patterned wafers.

[0021] In the step of forming the device separation region, it is required to suppress the polishing speed of the silicon nitride film, which serves as the termination layer of the substrate for the silicon oxide film. Sometimes, high polishing selectivity of silicon oxide relative to silicon nitride (polishing speed of silicon oxide / polishing speed of silicon nitride) is required. According to a sample of the polishing slurry of this embodiment, a sufficiently low polishing speed of silicon nitride can be obtained, and high polishing selectivity of silicon oxide relative to silicon nitride can be obtained. In this case, polishing is suitable for forming the device separation region. According to a sample of the polishing slurry of this embodiment, in the evaluation method described in the following embodiments, the polishing speed of silicon nitride in the control wafer can, for example, reach less than 2.0 nm / min (preferably less than 1.0 nm / min, etc.).

[0022] According to one aspect of the polishing slurry of this embodiment, when polishing a patterned wafer having square convex patterns (convex density: 100%) and square concave patterns (convex density: 0%), the polishing speed of the concave patterns (convex density: 0%) can be suppressed as an indicator of concavity characteristics. In this case, for example, when polishing the convex silicon oxide film in a patterned wafer with a silicon oxide film on the surface (in the case of STI formation, it also includes a patterned wafer with a silicon nitride film as a termination layer for the substrate, etc.), when polishing the silicon oxide film of the initial step thickness, it also causes the polishing of the concave silicon oxide film, or the polishing of the concave silicon oxide film in a pattern with a sufficiently wide width, to be faster than the polishing of the convex silicon oxide film, thereby easily suppressing the phenomenon of concavity (depression) like a plate. Based on the polishing slurry of this embodiment, in the evaluation method described in the following embodiments, as the polishing speed of 0% of the protrusion, for example, it is possible to obtain 500 nm / min or less (preferably 300 nm / min or less, 200 nm / min or less, etc.).

[0023] According to one sample of the polishing slurry of this embodiment, when polishing patterned wafers having square convex patterns (convex density: 100%) and square concave patterns (convex density: 0%), a high polishing speed ratio of 100% convex to 0% can be obtained as an indicator of planarization efficiency. According to one sample of the polishing slurry of this embodiment, in the evaluation method described in the embodiments described later, a polishing speed ratio exceeding 1.0 can be obtained as the convex 100% / convex 0% polishing speed ratio.

[0024] The polishing slurry of this embodiment can be used in CMP of semiconductor wafer materials, for example, it can be used to polish silicon oxide films disposed on the surface of semiconductor wafers. The polishing slurry of this embodiment can be used in the CMP step of ILD films. According to one aspect of the polishing slurry of this embodiment, high polishing speed can be obtained, and the agglomeration of abrasive particles and the generation of polishing scratches can be suppressed, and high flatness can be obtained.

[0025] (Abrasive grains) The abrasive grains contain cerium-based particles. By using cerium-based particles as abrasive grains, it is easy to reduce abrasion marks on the surface being abraded and to obtain a high abrasion rate for silicon oxide in the bumps of the patterned wafer.

[0026] Examples of cerium-based compounds that are 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. From the viewpoint of easily obtaining high polishing speeds of silicon oxide in the convex regions (convex regions with L / S=20μm / 80μm, convex regions with L / S=30μm / 70μm, etc.; the same applies below) of patterned wafers, cerium-based particles can include cerium oxide. By using cerium-based particles (cerium oxide particles) that include cerium oxide, it is easy to achieve high polishing speeds of silicon oxide in the convex regions of patterned wafers, and it is easy to obtain polished surfaces with fewer polishing scratches and excellent flatness.

[0027] The cerium oxide particles may contain polycrystalline cerium oxide with grain boundaries. Such polycrystalline cerium oxide particles have the property of becoming finer during grinding while active surfaces are revealed layer by layer, which can maintain a high grinding speed of silicon oxide in the bumps of the patterned wafer.

[0028] Examples of methods for manufacturing cerium oxide particles include calcination and oxidation methods based on hydrogen peroxide. During calcination, the temperature can be between 350 and 900°C. If the manufactured cerium oxide particles agglomerate, the particles can be mechanically pulverized. Pulverization methods can be, for example, dry pulverization using a jet mill or wet pulverization using a ball mill. For example, the jet mill described in "Proceedings of the Chemical Industry," Vol. 6, No. 5, (1980), pp. 527-532.

[0029] From the viewpoint of easily obtaining high polishing speeds for silicon oxide in the bumps of patterned wafers, and from the viewpoint of easily achieving high-speed polishing of silicon oxide in control-coated wafers without bump patterns, the zeta potential (surface potential) of the abrasive grains in the polishing slurry can be positive (the zeta potential can exceed 0 mV). The zeta potential of the abrasive grains can be measured, for example, using a dynamic light scattering zeta potential measuring device (e.g., manufactured by Beckman Coulter, Inc., product name: DelsaNano C). The zeta potential of the abrasive grains can be adjusted using additives. For example, by contacting the abrasive grains with an acidic component (e.g., acetic acid), abrasive grains with a positive zeta potential can be obtained.

[0030] From the viewpoint of easily achieving high polishing speeds for silicon oxide in the convex portions of patterned wafers and from the viewpoint of easily achieving high-speed polishing of silicon oxide in control-coated wafers without convex or concave patterns, the average particle size of the abrasive grains can be 50 nm or more, 70 nm or more, 100 nm or more, more than 100 nm, 105 nm or more, 110 nm or more, 115 nm or more, 120 nm or more, 125 nm or more, 130 nm or more, 135 nm or more, or 140 nm or more. Regarding the average particle size of the abrasive grains, from the viewpoint of easily suppressing the generation of polishing scratches and effectively achieving the effect of improving flatness such as suppressing dents in patterned wafers, it can 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 this perspective, the average particle size of the abrasive grains can 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, high-speed grinding and low-scratch characteristics of silicon oxide corresponding to the average particle size can be effectively obtained.

[0031] "Average particle size of the abrasive particles" refers to the central value of the volume distribution of a sample of a slurry containing abrasive particles, measured using a laser diffraction-scattering particle size distribution measuring device. This can be measured using a product manufactured by MicrotracBEL Corp., such as the Microtrac MT3300EXII. For example, a sample is prepared by dispersing abrasive particles in water and adjusting the abrasive particle content to 0.25% by mass (based on the total mass of the sample). This sample is then mounted on the measuring device to measure the central value of the volume distribution. When measuring the particle size of abrasive particles in a grinding slurry, a sample is prepared by adjusting the abrasive particle content in the slurry to 0.25% by mass (based on the total mass of the sample). This sample can be used and measured using the same method.

[0032] Regarding the content of abrasive particles, from the viewpoint of achieving an excellent balance between the grinding speed of silicon oxide in the protrusions of the patterned wafer and the dispersion stability of the abrasive particles, the content can be within the following ranges based on the total mass of the polishing slurry. The content of abrasive particles can 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 content of abrasive particles can 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 this perspective, the content of abrasive particles can 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] (Additive) [(A) Component: 4-Pyranone Compound] The additive in the polishing slurry of the first and second embodiments includes, as component (A), a 4-pyranone compound represented by general formula (1) (hereinafter, as appropriate, simply referred to as "4-pyranone compound"). It is speculated that by using a 4-pyranone compound, the interaction between the polishing slurry and silicon oxide is increased, thereby making it easier to increase the polishing speed. Furthermore, it is believed that although the 4-pyranone compound is an additive that can increase the interaction between the polishing slurry and silicon oxide, it does not have the effect of weakening the electrostatic repulsion or other repulsive forces between the polishing particles, thus suppressing the aggregation of polishing particles.

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

[0035] [Chemical 4]

[0036] In the formula, X11, X12, and X13 independently represent a hydrogen atom or a monovalent substituent. Examples of monovalent substituents include aldehyde, hydroxyl, carboxyl, carboxylate, sulfonic acid, phosphate, bromine, chlorine, iodine, fluorine, nitro, hydrazine, alkyl (e.g., alkyl with 1 to 8 carbon atoms), aryl (e.g., aryl with 6 to 12 carbon atoms), and alkenyl (e.g., alkenyl with 1 to 8 carbon atoms). Alkyl, aryl, and alkenyl groups can be substituted with OH, COOH, Br, Cl, I, NO2, etc. When X11, X12, and X13 are monovalent substituents, the substituent can be bonded to the carbon atom adjacent to the oxygen group; that is, X11 and X12 can be substituents. At least two of X11, X12, and X13 can be hydrogen atoms.

[0037] From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers and easily suppressing the aggregation of abrasive particles, 4-pyranone compounds may include at least one selected from the group consisting of 3-hydroxy-2-methyl-4-pyranone (also known as 3-hydroxy-2-methyl-4H-pyran-4-one, maltol), 5-hydroxy-2-(hydroxymethyl)-4-pyranone (also known as 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one, kojic acid), and 2-ethyl-3-hydroxy-4-pyranone (also known as 2-ethyl-3-hydroxy-4H-pyran-4-one), and may also include 3-hydroxy-2-methyl-4-pyranone. 4-pyranone compounds can be used alone or in combination of two or more. If two or more 4-pyranone compounds are used in combination, it is likely that the grinding speed of the flat surface being ground can be increased, and the in-surface uniformity can be improved.

[0038] 4-Pyranone compounds can be water-soluble. By using compounds with high solubility relative to water, the desired amount of additive can be well dissolved in the grinding fluid, and the grinding speed and the inhibition of agglomeration can be further improved to a higher level. The solubility of 4-pyranone compounds relative to 100g of water at room temperature (25°C) can be 0.001g or more, 0.005g or more, 0.01g or more, or 0.05g or more. There is no particular upper limit to the solubility.

[0039] From the viewpoint of further effectively improving the polishing speed of the bumps in the patterned wafer, the content of the 4-pyranone compound, based on the total mass of the polishing slurry, can be within the following range. The content of the 4-pyranone compound can 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, 0.032% 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-pyranone compounds can be less than 5% by mass, less than 3% by mass, less than 1% by mass, less than 0.8% by mass, less than 0.5% by mass, less than 0.3% by mass, less than 0.2% by mass, less than 0.18% by mass, less than 0.15% by mass, less than 0.13% by mass, less than 0.1% by mass, less than 0.08% by mass, less than 0.05% by mass, less than 0.04% by mass, less than 0.035% by mass, or less than 0.034% by mass. From this perspective, the content of 4-pyranone compounds can 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] From the viewpoint of further effectively improving the grinding speed of bumps in patterned wafers, the mass ratio A (4-pyranone compound / abrasive grain) of the content of 4-pyranone compound to the content of abrasive grains can be within the following ranges. The mass ratio A can 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 can 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 can 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 with a pH of 3.7 or higher in a 1 mM aqueous solution] The additive of the polishing slurry in the first embodiment includes component (B1) (excluding the compound equivalent to component (A)). The additive of the polishing slurry in the third embodiment is a compound equivalent to component (B1) (a nitrogen-containing hydroxyalkyl compound), for example, it may include ethylenediaminetetraethanol or ethylenediaminetetrapropanol. As component (B1), a compound equivalent to component (B2) can be used. By using component (B1), a high polishing speed of the protruding silicon oxide can be obtained by increasing the interaction between the polishing slurry and the protruding silicon oxide in the embossed pattern. Since compounds capable of acid dissociation in multiple stages have multiple pKas, it is complicated to select an effective compound based on pKa. However, according to the polishing slurry of the first embodiment, this complexity can be avoided by selecting the compound based on the pH given in the 1 mM aqueous solution. According to the first embodiment, a method for selecting additives in a polishing slurry based on a pH set in a 1 mM aqueous solution is provided, and a method for selecting additives in a polishing slurry based on a pH set in a 1 mM aqueous solution is also provided for selecting additives in a polishing slurry that can achieve a high polishing speed of silicon oxide with fine bump patterns when polishing patterned wafers.

[0042] From the viewpoint of obtaining a high grinding speed of silicon oxide in the bumps of a patterned wafer, the pH (25°C) of a 1 mM aqueous solution of component (B1) is 3.7 or higher. From the viewpoint of easily obtaining a high grinding speed of silicon oxide in the bumps of a patterned wafer, the pH of a 1 mM aqueous solution of component (B1) can be within the following range. The pH of a 1 mM aqueous solution of component (B1) can be 3.8 or higher, 4.0 or higher, 4.5 or higher, 5.0 or higher, more 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) can be below 14.0, 13.0, 12.0, 11.0, 10.5, 10.2, 10.0, 9.8, 9.5, 9.4, 9.2, 9.0, 8.6, 8.5, 8.0, 7.5, 7.2, 7.0, 6.7, 6.5, 6.2, 6.0, 5.9, 5.8, 5.6, 5.5, or 5.4. From this perspective, the pH of a 1 mM aqueous solution of component (B1) can 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 of component (B1) and water.

[0043] As component (B1), examples 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, and ethylenediaminetetraethanol (THEED: 2,2',2'',2'''-ethylenediaminetetraethanol (alias: N,N,N',N'-Tetrakis(2-hydroxyethyl)ethy Lenediamine (N,N,N',N'-tetra(2-hydroxyethyl)ethylenediamine) etc.), ethylenediaminetetrapropanol (EDTP: 1,1',1'',1'''-ethylenediaminetetra-2-propanol (also known as: N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine) etc.), triethanolamine (2,2',2''-nitrotriethanol, etc.), etc.

[0044] Examples of amino acids include histidine (L-histidine, etc.), lysine, arginine, glutamic acid (L-glutamic acid, etc.), glutamic acid (L-glutamic acid, etc.), proline (L-proline, etc.), hydroxyethylglycine (Bicine), cysteine ​​(L-cysteine, etc.), alanine (L-alanine, etc.), serine (L-serine, etc.), aminoacetic acid (glycine), tyrosine (L-tyrosine, etc.), and phenylalanine. Amino acids can be basic amino acids or aromatic amino acids. Examples of pyridine compounds include pyridine, hydroxypyridine (3-hydroxypyridine, 4-hydroxypyridine, etc.), pyridine carboxylic acids (nicotinic acid, pyridinecarboxylic acid, etc.), methylpyridine (2-methylpyridine, etc.), acetylopyridine (2-acetylopyridine, etc.), pyridineethanol (2-pyridineethanol, etc.), and aminopyridine (3-aminopyridine, etc.). Examples of imidazole compounds include imidazole, methylimidazolium (2-methylimidazolium, etc.), and dimethylimidazolium (1,2-dimethylimidazolium, etc.). Examples of pyrazole compounds include pyrazole and methylpyrazole. Examples of triazole compounds include triazoles (1,2,4-triazoles, etc.) and aminotriazoles (3-amine-1,2,4-triazoles, etc.). Examples of compounds containing an amino group and a benzene ring include aminobenzene (aniline) and o-aminobenzoic acid.

[0045] From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, the (B1) component may include at least one selected from the group consisting of amino acids, pyridine compounds, imidazole compounds, pyrazole compounds, triazole compounds, compounds containing amino groups and benzene rings, ethylenediaminetetraethanol, ethylenediaminetetrapropanol, and triethanolamine. It may also include at least one selected from the group consisting of amino acids, pyridine compounds, imidazole compounds, pyrazole compounds, triazole compounds, and ethylenediaminetetraethanol. Furthermore, it may include at least one selected from the group consisting of basic amino acids, aromatic amino acids, aminoacetic acid, hydroxypyridine, methylpyridine, acetylopyridine, pyridineethanol, and aminopyridine. The ingredient may contain at least one of the following groups: pyridine, imidazole, pyrazole, triazole, ethylenediaminetetraethanol, ethylenediaminetetrapropanol, and triethanolamine. It may also contain at least one of the following groups: basic amino acids, aromatic amino acids, aminoacetic acid, hydroxypyridine, methylpyridine, acetylglycine, pyridineethanol, aminopyridine, imidazole, pyrazole, triazole, ethylenediaminetetraethanol, and triethanolamine. It may also contain at least one of the following groups: histidine, glutamic acid, glutamic acid, proline, hydroxyethylglycine, cysteine, alanine, serine, aminoacetic acid, tyrosine, hydroxypyridine, pyridineethanol, imidazole, methylimidazole, ethylenediaminetetraethanol, ethylenediaminetetrapropanol, and triethanolamine. In particular, ingredient (B1) may be in the form containing hydroxypyridine, ethylenediaminetetraethanol, ethylenediaminetetrapropanol, or triethanolamine. From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, (B1) composition may contain compounds that are not equivalent to aromatic polyoxyethylene compounds (compounds having aromatic rings and polyoxyethylene chains), or compounds that do not have aromatic rings, or compounds that do not have polyoxyethylene chains.

[0046] From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, the molecular weight of component (B1) can be within the following range. The molecular weight of component (B1) can 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, or more than 250 or more. (B1) The molecular weight of the component can be less than 1000, less than 1000, less than 900, less than 800, less than 700, less than 600, less than 500, less than 400, less than 350, less than 300, less than 280, less than 250, less than 250, less than 240, less than 230, less than 210, less than 200, less than 180, less than 170, less than 160, less than 150, less than 148, less than 140, less than 130, less than 125, less than 123, less than 120, less than 110, less than 100, less than 90, less than 85, less than 80, or less than 70. From these perspectives, the molecular weight of component (B1) can 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 (the total amount of compounds equivalent to component (B1) and compounds not equivalent to component (B1); the same applies below), the content of ethylenediaminetetraethanol or ethylenediaminetetrapropanol, from the viewpoint of improving the grinding speed of silicon oxide in the bumps of the patterned wafer, improving the grinding speed of silicon oxide in the control wafer, and effectively improving the planarization efficiency, the content of B1, based on the total mass of the polishing slurry, can be within the following range. The content of B1 can 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, 0.11% by mass or more, 0.12% by mass or more, 0.13% by mass or more, 0.14% 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, or 0.4% by mass or more. The content of B1 can be less than 5% by mass, less than 3% by mass, less than 1% by mass, less than 0.5% by mass, less than 0.4% by mass, less than 0.3% by mass, less than 0.25% by mass, less than 0.2% by mass, less than 0.15% by mass, less than 0.14% by mass, less than 0.13% by mass, less than 0.12% by mass, less than 0.11% by mass, less than 0.1% by mass, less than 0.08% by mass, less than 0.06% by mass, less than 0.05% by mass, less than 0.04% by mass, less than 0.035% by mass, less than 0.03% by mass, less than 0.025% by mass, less than 0.02% by mass, less than 0.015% by mass, or less than 0.01% by mass. From this perspective, the content of component B1 can be 0.001–5% by mass, 0.001–1% by mass, 0.001–0.3% by mass, 0.001–0.2% 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, 0.01–0.2% by mass, 0.01–0.1% by mass, 0.01–0.05% by mass, 0.03–1% by mass, 0.03–0.3% by mass, 0.03–0.2% by mass, 0.03–0.1% by mass, or 0.03–0.05% by mass. The content of component (B1) also includes the content of compounds equivalent to components (B1) and (B2) (the same applies below).

[0048] The mass ratio of the content of component (B1) to the content of abrasive grains ((B1) component / abrasive grains), the mass ratio of the content of nitrogen-containing hydroxyalkyl compound to the content of abrasive grains (nitrogen-containing hydroxyalkyl compound / abrasive grains), the mass ratio of the content of ethylenediaminetetraethanol to the content of abrasive grains (ethylenediaminetetraethanol / abrasive grains), or the mass ratio of the content of ethylenediaminetetrapropanol to the content of abrasive grains (ethylenediaminetetrapropanol / abrasive grains) can be within the following range from the viewpoint of effectively improving the grinding speed of silicon oxide in the bumps of the patterned wafer, improving the grinding speed of silicon oxide in the control wafer, and improving the planarization efficiency. The mass ratio B11 can be above 0.001, above 0.005, above 0.01, above 0.05, above 0.08, above 0.1, above 0.11, above 0.12, above 0.13, above 0.14, above 0.15, above 0.16, above 0.2, above 0.25, above 0.3, above 0.4, above 0.5, above 1, or above 1. The mass ratio B11 can also be below 10, below 5, below 2, below 1, below 1, below 0.5, below 0.4, below 0.3, below 0.25, below 0.2, below 0.16, below 0.15, below 0.14, below 0.13, below 0.12, below 0.11, below 0.1, below 0.08, below 0.05, or below 0.01. From these perspectives, the mass ratio B11 can 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 of the content of component (B1) to the content of 4-pyranone compounds ((B1) component / 4-pyranone compounds), the mass ratio of the content of nitrogen-containing hydroxyalkyl compounds to the content of 4-pyranone compounds (nitrogen-containing hydroxyalkyl compounds / 4-pyranone compounds), the mass ratio of the content of ethylenediaminetetraethanol to the content of 4-pyranone compounds (ethylenediaminetetraethanol / 4-pyranone compounds), or the mass ratio of the content of ethylenediaminetetrapropanol to the content of 4-pyranone compounds (ethylenediaminetetraethanol / 4-pyranone compounds) can be within the following range from the viewpoint of effectively improving the grinding speed of silicon oxide in the bumps of the patterned wafer, improving the grinding speed of silicon oxide in the control wafer, and improving the planarization efficiency. The mass ratio B12 can be 0.01 or higher, 0.05 or higher, 0.1 or higher, 0.3 or higher, 0.5 or higher, 0.6 or higher, 0.8 or higher, 0.85 or higher, 0.9 or higher, 1 or higher, exceeding 1, 1.1 or higher, 1.2 or higher, 1.4 or higher, 1.5 or higher, 2 or higher, 5 or higher, or 8 or higher. The mass ratio B12 can be less than 10, less than 8, less than 5, less than 2, less than 1.5, less than 1.4, less than 1.2, less than 1.1, less than 1, less than 1, less than 1, 0.9 or less, less than 0.85, less than 0.8, less than 0.6, less than 0.5, less than 0.3 or less, or less than 0.1. From this perspective, the mass ratio B12 can 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 carboxyl, carboxylate, amino, and hydroxyl groups] The additive of the polishing slurry in the second embodiment includes a (B2) component (excluding compounds equivalent to component (A)). By using component (B2), a high polishing speed of the silicon oxide on the raised portion of the pattern can be obtained by increasing the interaction between the polishing slurry and the silicon oxide on the raised portion of the pattern. From the viewpoint of easily obtaining a high polishing speed of silicon oxide on the raised portion of the patterned wafer, component (B2) may have at least one component selected from the group consisting of carboxyl and carboxylate groups. As component (B2), a compound that is also equivalent to component (B1) can be used. In cases where it is necessary to identify whether such a compound should belong to component (B1) or component (B2), the compound is set to belong to component (B2). Examples of salts that are carboxylate groups include alkali metal salts such as sodium salts and potassium salts.

[0051] (B2) The component may have at least one selected from the group consisting of aromatic rings, heterocyclic rings (other than aromatic rings), and alicyclic rings. The aromatic ring may be a heteroaromatic ring. Examples of aromatic rings include benzene rings, naphthalene rings, anthracene rings, pyridine rings, quinoline rings, etc. (B2) The component may have an aromatic ring different from the benzene ring.

[0052] From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, component (B2) may contain an aromatic compound (a compound having an aromatic ring), or may contain at least one selected from the group consisting of aromatic carboxylic acids (aromatic compounds having a carboxyl group) and aromatic carboxylate salts (aromatic compounds having a carboxylate group). Component (B2) may contain at least one selected from the group consisting of aromatic aminocarboxylic acids (aminobenzoic acid, aminobenzenesulfonic acid, etc.), aromatic hydroxycarboxylic acids (aromatic hydroxycarboxylic acids, excluding aromatic aminocarboxylic acids), aromatic carboxylic acids without amino and hydroxyl groups (quinoline carboxylic acids, pyridine carboxylic acids, etc.), and their salts, or may contain at least one selected from the group consisting of aromatic aminocarboxylic acids, quinoline carboxylic acids, pyridine carboxylic acids, and their salts.

[0053] From the viewpoint of easily obtaining high grinding speed of silicon oxide in the convex part of the patterned wafer and effectively obtaining the effect of improving planarization efficiency, (B2) component may include 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, such salts and salicylaldehyde oxime.

[0054] From the viewpoint of easily obtaining a high grinding speed of silicon oxide in the bumps of a patterned wafer, the benzoic acid derivative may include at least one selected from the group consisting of hydroxybenzoic acid and aminobenzoic acid. Examples of hydroxybenzoic acid include salicylic acid (2-hydroxybenzoic acid) and 4-hydroxybenzoic acid. Examples of aminobenzoic acid include o-aminobenzoic acid. Examples of hydroxyphenylacetic acid include mandelic acid. Examples of alkyl salicylic acid include methyl salicylic acid (e.g., 3-methylsalicylic acid). From the viewpoint of easily obtaining a high grinding speed of silicon oxide in the bumps of a patterned wafer, the phthalic acid derivative may include at least one selected from the group consisting of alkyl phthalic acid, amino phthalic acid, and sulfophthalic acid. Examples of alkyl phthalic acid include methyl phthalic acid (e.g., 4-methylphthalic acid). Examples of amino phthalic acid include 4-aminophthalic acid. Examples of sulfophthalic acids include 4-sulfophthalic acid. From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, quinoline derivatives may include quinoline carboxylic acids. Examples of quinoline carboxylic acids include quinaldinic acid. From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, pyridine derivatives may include pyridine carboxylic acids. Examples of pyridine carboxylic acids include pyridinecarboxylic acid and nicotinic acid. Examples of aminobenzenesulfonic acids include o-aminobenzenesulfonic acid. In particular, component (B2) may be in the form of at least one selected from the group consisting of quinaldinic acid and its salts, or in the form of at least one selected from the group consisting of o-aminobenzoic acid and its salts, or in the form of at least one selected from the group consisting of pyridinecarboxylic acid and its salts.

[0055] From the viewpoint of easily achieving high-speed polishing (e.g., polishing speed of 250 nm / min or higher) of silicon oxide in a control-coated wafer without a raised or recessed pattern, component (B2) may also include at least one selected from the group consisting of benzoic acid, 4-hydroxybenzoic acid, aminobenzoic acid, hydroxyphenylacetic acid, quinoline derivatives and pyridine derivatives.

[0056] From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, the molecular weight of component (B2) can be within the following ranges. The molecular weight of component (B2) can 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) can be less than 1000, less than 1000, less than 900, less than 800, less than 700, less than 600, less than 500, less than 400, less than 300, less than 250, less than 200, less than 180, less than 170, less than 160, less than 150, less than 140, less than 138, less than 135, less than 130, or less than 125. From these perspectives, the molecular weight of component (B2) can 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] From the viewpoint of effectively improving the polishing speed of silicon oxide in the convex portion of a patterned wafer and from the viewpoint of easily achieving high-speed polishing of silicon oxide in a control-coated wafer without a raised or recessed pattern, the content of component (B2), based on the total mass of the polishing slurry, can be within the following range: The content of component (B2) can 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. (B2) The content of component can be less than 5% by mass, less than 3% by mass, less than 1% by mass, less than 0.5% by mass, less than 0.3% by mass, less than 0.2% by mass, less than 0.15% by mass, less than 0.1% by mass, less than 0.08% by mass, less than 0.06% by mass, less than 0.05% by mass, less than 0.04% by mass, less than 0.035% by mass, less than 0.03% by mass, less than 0.025% by mass, less than 0.02% by mass, less than 0.015% by mass, or less than 0.01% by mass. From this perspective, the content of component (B2) can 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, 0.03–5% by mass, 0.03–1% by mass, 0.03–0.3% by mass, 0.03–0.1% by mass, or 0.03–0.05% by mass. The content of component (B2) also includes the content of compounds equivalent to components (B1) and (B2) (the same applies below).

[0058] From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the convex portion of patterned wafers and easily achieving high-speed grinding of silicon oxide in control-coated wafers without convex or concave patterns, the mass ratio B21 ((B2) component / abrasive grains) of the content of component (B2) relative to the content of abrasive grains can be within the following range. The mass ratio B21 can 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 can be less than 1, less than 1, less than 0.8, less than 0.6, less than 0.5, less than 0.4, less than 0.3, less than 0.25, less than 0.2, less than 0.16, less than 0.15, less than 0.12, less than 0.1, less than 0.08, less than 0.05, or less than 0.04. From this perspective, the mass ratio B21 can be 0.01–1, 0.01–0.5, 0.01–0.2, 0.01–0.1, 0.05–1, 0.05–0.5, 0.05–0.2, 0.05–0.1, 0.1–1, 0.1–0.5, or 0.1–0.2.

[0059] From the viewpoint of easily obtaining high polishing speeds of silicon oxide in the convex portions of patterned wafers and easily achieving high-speed polishing of silicon oxide in control-coated wafers without convex or concave patterns, the mass ratio B22 ((B2) component / 4-pyranone compound) of the content of (B2) component to the content of 4-pyranone compound can be within the following ranges. The mass ratio B22 can 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 can 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 can 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 compound] The grinding fluid additive of the third embodiment includes a compound having two or more nitrogen atoms bonded to a hydroxyalkyl group (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. As the hydroxyalkyl group bonded to the nitrogen atom, the nitrogen-containing hydroxyalkyl compound can use an alkyl group without any substituents other than the hydroxyl group.

[0061] From the viewpoint of easily obtaining high grinding speed of silicon oxide in the bumps of patterned wafers, nitrogen-containing hydroxyalkyl compounds may include compounds having nitrogen atoms bonded with two hydroxyalkyl groups, or compounds having two or more nitrogen atoms bonded with two hydroxyalkyl groups.

[0062] From the viewpoint of easily obtaining a high grinding speed of silicon oxide in the bumps of a patterned wafer, the number of nitrogen atoms in one molecule of a nitrogen-containing hydroxyalkyl compound can be 2 to 5, 2 to 4, or 2 to 3. From the viewpoint of easily obtaining a high grinding speed of silicon oxide in the bumps of a patterned wafer, the number of hydroxyl groups in one molecule of a nitrogen-containing hydroxyalkyl compound can be 2 to 6, 2 to 5, 2 to 4, 3 to 6, 3 to 5, 3 to 4, 4 to 6, or 4 to 5.

[0063] Regarding nitrogen-containing hydroxyalkyl compounds, from the viewpoint of easily obtaining high grinding speeds of silicon oxide in the convex portions of patterned wafers, the hydroxyalkyl group bonded to the nitrogen atom can be a hydroxyalkyl group having 1 to 4, 2 to 4, 3 to 4, 1 to 3, 2 to 3, or 1 to 2 carbon atoms. Regarding nitrogen-containing hydroxyalkyl compounds, from the viewpoint of easily obtaining high grinding speeds of silicon oxide in the convex portions of patterned wafers, the hydroxyalkyl group bonded to the nitrogen atom can be a hydroxyalkyl group having 1 to 3 or 1 to 2 hydroxyl groups.

[0064] Regarding nitrogen-containing hydroxyalkyl compounds, from the viewpoint of easily obtaining high grinding speed of silicon oxide in the convex part of the patterned wafer, an alkyl group can be present between the two nitrogen atoms of the hydroxyalkyl group, and the carbon number of the alkyl group can be 1 to 4, 2 to 4, 1 to 3, 2 to 3 or 1 to 2.

[0065] From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, nitrogen-containing hydroxyalkyl compounds may include compounds represented by the following general formula (I).

[0066] [Chemical 5][In the formula, n is an integer greater than or equal to 1, R11, R12, R13 and R14 independently represent hydrogen atoms or organic groups, one or both of R11 and R12 are hydroxyalkyl, and one or both of R13 and R14 are hydroxyalkyl.]

[0067] n, as the number of carbon atoms in the alkyl group bonded to the two nitrogen atoms of the hydroxyalkyl group, can be within the range described above. The organic group can be a substituted or unsubstituted alkyl group, or a hydroxyalkyl group, or a group having a nitrogen atom bonded to the hydroxyalkyl group. Examples of substituents for the alkyl group include hydroxyl, carboxyl, amino, sulfonic acid, and nitro groups. When R11, R12, R13, or R14 is a hydroxyalkyl group, the number of carbon atoms in the hydroxyalkyl group bonded to the nitrogen atom can be within the range described above.

[0068] Examples of nitrogen-containing hydroxyalkyl compounds include ethylenediaminetetraethanol (THEED: 2,2',2'',2'''-ethylenediaminetetraethanol (alias: N,N,N',N'-Tetrakis(2-hydroxyethyl)ethylenediamine (N,N,N',N'-tetra(2-hydroxyethyl)ethylenediamine)), ethylenediaminetetrapropanol (EDTP: 1,1',1'',1'''-ethylenediaminetetra-2-propanol (alias: N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine (N,N,N',N'-tetra(2-hydroxypropyl)ethylenediamine)), and N,N,N',N'',N''-penta(2-hydroxypropyl)diethyleneethyltriamine, etc. From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, nitrogen-containing hydroxyalkyl compounds may include at least one selected from the group consisting of ethylenediaminetetraethanol and ethylenediaminetetrapropanol, or may include either ethylenediaminetetraethanol or ethylenediaminetetrapropanol. From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, nitrogen-containing hydroxyalkyl compounds may include compounds without carboxyl groups.

[0069] From the viewpoint of easily obtaining high grinding speeds of silicon oxide in the bumps of patterned wafers, the molecular weight of nitrogen-containing hydroxyalkyl compounds can be within the following ranges. The molecular weight of nitrogen-containing hydroxyalkyl compounds can 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, exceeding 250 or 280 or more. The molecular weight of nitrogen-containing hydroxyalkyl compounds can be less than 1000, less than 1000, less than 900, less than 800, less than 700, less than 600, less than 500, less than 400, less than 350, less than 300, less than 280, less than 250, less than 250, less than 250 or 240 or less. From these perspectives, the molecular weight of nitrogen-containing hydroxyalkyl compounds can 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 can be within the range described above.

[0071] [Saturated Monocarboxylic Acid] The additive in the polishing slurry of this embodiment may include saturated monocarboxylic acid. By using saturated monocarboxylic acid, the following advantages can be obtained: it is easy to obtain a sufficiently low polishing speed of silicon nitride that can be used as a stopper material, and not only can the dispersion of cerium-based particles be improved, but also the in-plane uniformity of the polished surface deviation index is improved without reducing the polishing speed of the patterned wafer (e.g., a semiconductor substrate with a raised and recessed pattern).

[0072] Examples of saturated monocarboxylic acids include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, neovaleric acid, hydroangelic acid, hexanoic acid, 2-methylpentanoic acid, 4-methylpentanoic acid, 2,3-dimethylbutyric acid, 2-ethylbutyric acid, 2,2-dimethylbutyric acid, and 3,3-dimethylbutyric acid. From the viewpoint of easily obtaining the aforementioned additive effects of saturated monocarboxylic acids, saturated monocarboxylic acids may include aliphatic carboxylic acids. Regarding saturated monocarboxylic acids, from the viewpoint of effectively obtaining the effect of suppressing the grinding speed of silicon nitride and further improving the effect of improving in-plane uniformity, saturated monocarboxylic acids with 2 to 6 carbon atoms may be included, and at least one may be selected from the group consisting of acetic acid and propionic acid.

[0073] Regarding the content of saturated monocarboxylic acids (e.g., saturated monocarboxylic acids with 2 to 6 carbon atoms), from the viewpoint of improving in-plane uniformity, improving the grinding speed of patterned wafers, and effectively suppressing the grinding speed of silicon nitride, the content can be within the following range based on the total mass of the polishing slurry. The content of saturated monocarboxylic acids can 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 content of saturated monocarboxylic acids can be less than 5% by mass, less than 3% by mass, less than 1% by mass, less than 0.5% by mass, less than 0.4% by mass, less than 0.3% by mass, less than 0.2% by mass, less than 0.1% by mass, less than 0.05% by mass, or less than 0.045% by mass. From this perspective, the content of saturated monocarboxylic acids can be 0.0001–5% by mass, 0.0001–1% by mass, 0.0001–0.1% by mass, 0.0001–0.05% by mass, 0.01–5% by mass, 0.01–1% by mass, 0.01–0.1% by mass, 0.01–0.05% by mass, 0.03–5% by mass, 0.03–1% by mass, 0.03–0.1% by mass, or 0.03–0.05% by mass. The content of saturated monocarboxylic acids can be less than 0.04% by mass, less than 0.03% by mass, less than 0.02% by mass, less than 0.01% by mass, less than 0.005% by mass, less than 0.002% by mass, less than 0.001% by mass, less than 0.0005% by mass, or substantially 0% by mass.

[0074] [Nonionic polymers and cationic compounds] The additive in the polishing slurry of 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 polished surface, protecting concave surfaces until convex surfaces are scraped off while maintaining the high-speed polishing performance of the patterned wafer, thereby achieving high flatness. It is believed that since this effect can be obtained with a smaller amount when using at least one of the nonionic polymers and cationic additives, and since the surface potential of cerium-based particles (e.g., cerium oxide particles) is dispersed on the positive side without the agglomeration effect of anionic surfactants, the formation of concavities is reduced while the formation of polishing scratches is reduced, resulting in high flatness. The reason for the effect is not limited to this. When using at least one of the nonionic polymers and cationic additives, the effect of improving the in-plane uniformity of polishing speed can also be obtained.

[0075] As nonionic polymers, examples include ether-type surfactants such as polyglycerol, polyglycerol fatty acid esters, polyoxyethylene styrene phenyl ether, polyoxyethylene dehydrated sorbitol monolaurate, polyoxyethylene lauryl ether, polyoxypropylene polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene polyoxypropylene ether derivatives, polyoxypropylene glycerol ether, polyethylene glycol, methoxy polyethylene glycol, and ethynylene diols; ester-type surfactants such as dehydrated sorbitol 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; alkanolamine-type surfactants such as fatty acid alkanolamines and polyoxyethylene fatty acid alkanolamines; polyvinylpyrrolidone; nonionic polyacrylamide; and nonionic polydimethylacrylamide. From the viewpoint that the above-mentioned additive effects of nonionic polymers can be easily obtained, nonionic polymers may contain ether-type surfactants.

[0076] Regarding the content of the nonionic polymer, from the viewpoint of effectively obtaining the effect of improving the in-plane uniformity of the grinding speed and the effect of improving the flatness such as the suppression of depressions in the patterned wafer, based on the total mass of the grinding slurry, it can be within the following ranges: The content of the nonionic polymer can 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 the nonionic polymer can 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 the nonionic polymer can be 0.05 to 5% by mass.

[0077] The cationic compound may be selected from at least one of the group consisting of cationic monomers and cationic polymers. Examples of cationic compounds include ethyleneimine, allylamine, dimethyl (meth)acrylamide, chitosan, diallylamine, methyldiallylamine, (meth)acrylic acid, diallyl dimethylammonium chloride, (meth)acrylamide, dimethylamine, epichlorohydrin, ammonia, dimethylaminoethyl (meth)acrylate, dicyandiamine, diethylenetriamine, vinylpyrrolidone·dimethylaminoethyl (meth)acrylate diethyl sulfate, diallyl dimethylammonium chloride·(meth)acrylamide, diallyl methyl ethylammonium ethyl sulfate, and other cationic monomers; cationic polymers of these cationic monomers (cationic homopolymers and cationic copolymers (dimethylamine / ammonia (NH3) / epoxychlorohydrin copolymer, dimethylamine / epoxychlorohydrin copolymer, etc.)); derivatives of the aforementioned cationic monomers and other polymeric compounds; and surfactants such as coconutamine acetate and stearamine acetate. From the viewpoint that the aforementioned additive effects of cationic compounds are readily apparent, cationic compounds may comprise reactants containing dimethylamine and epichlorohydrin. Reactants containing dimethylamine and epichlorohydrin may be reactants containing at least dimethylamine, ammonia, and epichlorohydrin.

[0078] From the viewpoint of effectively obtaining flatness such as depression suppression in patterned wafers, the content of the cationic compound, based on the total mass of the polishing slurry, can be within the following ranges: The content of the cationic compound can 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 the cationic compound can 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 the cationic compound can be from 0.0005 to 0.5% by mass.

[0079] [Other Additives] The grinding fluid of this embodiment may further contain other components (not corresponding to the components mentioned above) depending on the desired properties. Examples of such components include pH adjusters (described later); polar solvents such as ethanol and acetone; and cyclic monocarboxylic acids.

[0080] Regarding the polishing slurry of this embodiment, it may contain compound a with a molecular weight of 100,000 or less and having four or more hydroxyl groups, or it may not contain compound a. The content of compound a, based on the total mass of the polishing slurry, may be less than 0.01% by mass, less than 0.01% by mass, less than 0.001% by mass, less than 0.0001% by mass, or substantially 0% by mass. The polishing slurry of this embodiment may contain compound b having four or more amino groups, or it may not contain compound b. The content of compound b, based on the total mass of the polishing slurry, may be less than 0.001% by mass, less than 0.001% by mass, less than 0.0001% by mass, less than 0.00001% by mass, or substantially 0% by mass. The mass ratio of the content of compound a to the content of compound b (compound a / compound b) may be less than 0.10 or less than 0.10.

[0081] (Water) Water is not particularly limited and may include at least one selected from the group consisting of deionized water, ion-exchanged water and ultrapure water.

[0082] (pH) The pH (25°C) of the polishing slurry in this embodiment can be within the following range. From the viewpoints of easily suppressing the aggregation of abrasive particles, easily obtaining high polishing speeds of silicon oxide (e.g., silicon oxide in the bumps of a patterned wafer), easily suppressing the polishing speed of silicon nitride that can be used as a termination layer material, and easily obtaining the effects of the aforementioned additives, the pH can be 12.0 or less, 11.0 or less, 10.5 or less, less than 10.5, 10.0 or less, less than 10.0, 9.5 or less, 9.0 or less, less than 9.0. Below 8.5, below 8.0, below 8.0, below 7.5, below 7.0, below 7.0, below 6.5, below 6.0, below 6.0, below 5.6, below 5.5, below 5.5, below 5.3, below 5.1, below 5.0, below 4.8, below 4.7, below 4.6, below 4.5, below 4.4, below 4.3, below 4.2, below 4.1, below 4.0, below 4.0, below 3.8 or below 3.7. From the viewpoint that it is easy to suppress the silicon oxide of the grinding object to have a large absolute value of zeta potential on the same positive side as the cerium-based particles (e.g., cerium oxide particles), and to easily obtain a high grinding speed of silicon oxide in the bumps of the patterned wafer, the pH can be 3.0 or higher, 3.5 or higher, 3.7 or higher, 3.8 or higher, 4.0 or higher, more 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, more than 5.5, 5.6 or higher, 6.0 or higher, more than 6.0, 6.5 or higher, 7.0 or higher, or more than 7.0. From these perspectives, the pH can be 3.0–12.0, 3.0 or higher but less than 9.0, 3.0–8.0, 3.0–5.5, 3.0–5.0, 3.5–12.0, 3.5 or higher but less than 9.0, 3.5–8.0, 3.5–5.5, 3.5–5.0, 4.0–12.0, 4.0 or higher but less than 9.0, 4.0–8.0, 4.0–5.5, or 4.0–5.0. When the pH is 4.0–5.0, a high polishing speed in the bumps of the patterned wafer is particularly easy to obtain by using component (A) and component (B1) or component (B2). The polishing slurry of the first embodiment may be such that component (B1) contains ethylenediaminetetraethanol, and the pH of the polishing slurry is 8.0 or lower. The pH can be measured by the method described in the examples.

[0083] It is believed that by using a pH of 3.0 to 5.5, in addition to the above, the following two effects can also be obtained. (1) Protons, hydroxyl anions, etc., act on the compound formulated as an additive to change the chemical form of the compound, and by increasing the wettability or affinity of silicon oxide relative to the substrate surface, a high grinding speed can be easily obtained. (2) When the abrasive grains contain cerium-based compounds (e.g., cerium oxide), the contact efficiency between the abrasive grains and silicon oxide is improved, and a high grinding speed can be easily achieved. This is because cerium-based compounds have a positive zeta potential, while silicon oxide has a negative zeta potential, and electrostatic attraction plays a role between the two.

[0084] Regarding pH, since it can vary depending on the type of compound used as an additive, a pH adjuster can be used to adjust the pH to the aforementioned range. There are no particular limitations on the pH adjuster; for example, acids such as nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, and boric acid can be used; bases such as sodium hydroxide, ammonia (e.g., ammonia water), potassium hydroxide, and calcium hydroxide can also be used for pH adjustment. Furthermore, from the viewpoint of improving productivity, the polishing slurry can be prepared without using a pH adjuster and directly applied to CMP.

[0085] <Preparation and Usage of Polishing Fluid> The polishing fluid of this embodiment can be classified into (a) ordinary type, (b) concentrated type, and (c) multi-liquid type (e.g., two-liquid type, CMP polishing fluid kit), and the preparation and usage methods differ according to the type. (a) Ordinary type is a polishing fluid that can be used directly without dilution or other pretreatment during polishing. (b) Concentrated type is a polishing fluid containing concentrated components compared to (a) ordinary type, taking into account the convenience of storage or transportation. (c) Multi-liquid type is a polishing fluid in which the components are divided into multiple liquid states (e.g., a first liquid containing certain components and a second liquid containing other components) during storage or transportation, and these liquids are mixed for use.

[0086] (a) The common type can be obtained by dissolving or dispersing the grinding particles and additives in water, which is the main dispersion medium. For example, when preparing 1000g of grinding liquid containing 0.5 parts by mass of grinding particles and 0.1 parts by mass of additives relative to 100 parts by mass of grinding liquid, the mixing amount can be adjusted to 5g of grinding particles and 1g of additives relative to the total amount of grinding liquid.

[0087] When preparing the grinding slurry, for example, a mixer, homogenizer, ultrasonic disperser, wet ball mill, etc., can be used. Furthermore, during the preparation of the grinding slurry, a process to micronize the grinding particles can be performed to ensure that the average particle size of the grinding particles is within a desired range. The micronization process can be carried out using a sedimentation classification method or a high-pressure homogenizer. The sedimentation classification method includes a step of forcibly settling the slurry containing the grinding particles using a centrifuge and a step of removing only the supernatant. On the other hand, the method using a high-pressure homogenizer involves using high pressure to cause the grinding particles in the dispersion medium to collide with each other.

[0088] (b) The concentrated type is immediately diluted with water before use to achieve the desired concentration of the ingredients. After dilution, it can be stirred for any period of time until the same liquid properties (pH, particle size, etc.) and grinding properties (grinding speed of silicon oxide, grinding selectivity ratio of silicon oxide to silicon nitride, etc.) as the ordinary type (a) are obtained. In this (b) concentrated type, since the volume is smaller depending on the degree of concentration, the costs of storage and transportation can be reduced.

[0089] The concentration ratio can be 1.5 times or more, 2 times or more, 3 times or more, or 5 times or more. If the concentration ratio is 1.5 times or more, it tends to be more favorable for preservation and transportation compared to cases where it is less than 1.5 times. The concentration ratio can be 40 times or less, 20 times or less, or 15 times or less. If the concentration ratio is 40 times or less, it tends to be more favorable for suppressing the agglomeration of grinding particles compared to cases where it is more than 40 times.

[0090] (c) The multi-liquid type, by appropriately dividing into individual liquids (liquid 1, liquid 2, etc.), has the advantage of avoiding agglomeration of grinding particles compared to the concentrated type (b). The components contained in each liquid can be arbitrary. (c) The multi-liquid type (CMP grinding slurry kit) is a grinding slurry kit used to obtain grinding slurry by mixing a first liquid (slurry) and a second liquid (additive liquid). In (c) the multi-liquid type, the components of the CMP grinding slurry are stored as a first liquid and a second liquid. The first liquid contains grinding particles and water, and the second liquid contains at least one of the additives and water. In the first state sample of (c) the multi-liquid type, the first liquid contains grinding particles and water, and the second liquid contains at least one selected from the group consisting of component (A), component (B1), and component (B2) and water. In the second state of the multi-liquid type (c), the first liquid contains abrasive particles, component (A), and water, and the second liquid contains at least one selected from the group consisting of components (B1) and (B2) and water. In the third state of the multi-liquid type (c), the first liquid contains abrasive particles, component (A), component (B1), and water, and the second liquid contains component (B2) and water. In the fourth state of the multi-liquid type (c), the first liquid contains at least one selected from the group consisting of abrasive particles, component (B1), and component (B2), and water, and the second liquid contains component (A) and water. In the fifth state of the multi-liquid type (c), the first liquid contains abrasive particles and water, and the second liquid contains a nitrogen-containing hydroxyalkyl compound (ethylenediaminetetraethanol, ethylenediaminetetrapropanol, etc.) and water. The first and second liquids may contain other components formulated as needed. In this case, in order to improve the dispersibility of the grinding particles in the first solution, any acid or base can be used to prepare the first solution, or the pH can be adjusted.

[0091] (c) Multi-liquid type grinding slurries are useful when combined with components that tend to reduce grinding properties in a shorter time by means of agglomeration of abrasive particles during mixing. Furthermore, from the viewpoint of reducing storage and transportation costs, at least one of the liquids (first liquid, second liquid, etc.) can be made concentrated. In this case, when using the grinding slurry, it is only necessary to mix each liquid with water. The concentration ratio and pH of each liquid are arbitrary; from the viewpoint of liquid properties and grinding properties, it is sufficient as long as the final mixture is to the same degree as (a) ordinary type grinding slurry.

[0092] <Grinding Method> The grinding method of this embodiment includes a grinding step of grinding a surface to be ground using the grinding fluid of this embodiment. The grinding fluid used in the grinding step may be a grinding fluid obtained by mixing the first fluid and the second fluid in the above-mentioned grinding fluid kit. That is, the grinding method of this embodiment may include a grinding step of grinding a surface to be ground using a grinding fluid obtained by mixing the first fluid and the second fluid in the above-mentioned grinding fluid kit.

[0093] The polishing method of this embodiment can use polishing slurry with adjusted component content and pH, and planarize a substrate with a silicon oxide film on its surface using CMP technology. Like the polishing of ILD films, the polishing method of this embodiment is suitable for polishing applications requiring high speed, high flatness, and low polishing scratches, and is suitable for polishing multiple ILD films in a short time. According to one aspect of the polishing method of this embodiment, it is possible to effectively increase the polishing speed of silicon oxide in control-coated wafers and improve in-plane uniformity. According to one aspect of the polishing method of this embodiment, since the polishing slurry of this embodiment is used, it is possible to suppress the aggregation of abrasive particles and reduce the generation of polishing scratches while achieving a sufficiently high polishing speed.

[0094] The polishing step can be a step in which the polishing slurry of this embodiment is supplied between the substrate and the polishing member (polishing member, polishing pad, etc.), and the substrate is polished by the polishing member. The polishing method of this embodiment is applicable to the polishing of a substrate having a silicon oxide film on its surface. Therefore, the surface to be polished can contain silicon oxide, and the polishing step can be a step in which the polishing slurry of this embodiment is supplied between the silicon oxide film in the substrate having a silicon oxide film on its surface and the polishing member, and the silicon oxide film is polished by the polishing member.

[0095] The polishing method of this embodiment can be as follows: the surface to be polished has a raised / recessed pattern composed of raised portions (line portions) and recessed portions (space portions), and the raised portions contain silicon oxide. The width of the raised portions in the raised / recessed pattern can be 30 μm or less or 20 μm or less. The width of the raised portions in the raised / recessed pattern can be 10 μm or more or 20 μm or more. The total width of the raised portions and the width of the recessed portions in the raised / recessed pattern can be 200 μm or less or 100 μm or less. The total width of the raised portions and the width of the recessed portions in the raised / recessed pattern can be 80 μm or more or 100 μm or more.

[0096] The polishing method of this embodiment is applicable to polishing a substrate with a silicon oxide film on its surface during the manufacturing process of the device. Examples of such devices include: individual semiconductors such as diodes, transistors, compound semiconductors, thermal resistors, varistors, and thyristors; memory elements such as DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), EPROM (Erasable Programmable Read-Only Memory), Masked ROM (Mask Read-Only Memory), EEPROM (Electrically Erasable 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 (Megamicrowave Integrated Circuits); hybrid integrated circuits (hybrid ICs); light-emitting diodes; and photoelectric conversion elements such as charge-bonded elements.

[0097] According to the polishing slurry of this embodiment, a high polishing speed can be achieved with minimal dependence on the unevenness of the surface being polished. Therefore, the polishing method using this polishing slurry can also be applied to substrates for which it is difficult to achieve a high polishing speed using methods with previous polishing slurries.

[0098] The polishing method of this embodiment is suitable for planarizing a surface with steps (undulations) on its surface. For example, a logic semiconductor device can be cited as a substrate having such a surface. Furthermore, the polishing method of this embodiment is suitable for polishing surfaces containing portions that, when viewed from above, have concave or convex parts that form a T-shape or grid shape. For example, the polishing method of this embodiment can also polish silicon oxide films disposed on the surface of semiconductor devices (DRAM, flash memory, etc.) containing memory cells at high speeds. This indicates that high polishing speeds are difficult to achieve with previous methods using CMP polishing slurries, and the polishing slurry of this embodiment is largely independent of the unevenness of the surface being polished, enabling high polishing speeds.

[0099] The substrate is not limited to a substrate with only a silicon oxide film on its surface. In addition to a silicon oxide film, it can be a substrate with a silicon nitride film, polycrystalline silicon film, etc., further present on its surface. The substrate can be a substrate that mainly contains inorganic insulating films such as silicon oxide, glass, and silicon nitride on a wiring board with predetermined wiring; or films such as polycrystalline silicon, Al, Cu, Ti, TiN, W, Ta, and TaN.

[0100] Hereinafter, as an example of the process of the polishing method including this embodiment, the process of forming an ILD film (interlayer insulating film) structure by CMP will be described. FIG1 is a schematic cross-sectional view showing the process of polishing the ILD film, and shows the process of forming an ILD film between wirings. FIG1(a) is a schematic cross-sectional view showing the substrate before polishing. FIG1(b) is a schematic cross-sectional view showing the substrate after polishing.

[0101] As shown in FIG1(a), in the substrate 100 before polishing, a wiring 20 is formed on a lower substrate (not shown) having a predetermined lower wiring (not shown) via an ILD film 10, and a silicon oxide film 30 is formed to cover the 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 becomes higher than the other portion, thereby creating a step D on the surface of the silicon oxide film 30. The wiring 20 is connected to the lower wiring, etc., by forming a contact plug 40 that penetrates the ILD film 10.

[0102] In the process of forming the ILD film structure, in order to eliminate the step difference D, unnecessary parts that protrude locally on the surface of the silicon oxide film 30 are preferentially removed by CMP. When polishing the silicon oxide film 30, a substrate 100 is placed on a polishing member so that the surface of the silicon oxide film 30 abuts against the polishing member, and the surface of the silicon oxide film 30 is polished by the polishing member. More specifically, the polished surface side of the silicon oxide film 30 is pressed against the polishing member of the polishing platform, and polishing fluid is supplied between the polished surface and the polishing member while the two are moved relative to each other to polish the silicon oxide film 30. In this way, the step difference D is eliminated, and finally, as shown in FIG1(b), the height of the wiring 20 portion on the surface of the silicon oxide film 30 is approximately the same as the height of other portions, and a substrate 100a with a silicon oxide film 30 (ILD film) having a flat surface can be obtained.

[0103] As a grinding apparatus used for grinding, for example, a device can be used that has a support for holding the substrate, a grinding platform on which the grinding pad is attached, and a mechanism for supplying grinding fluid to the grinding pad. Examples of grinding apparatuses include grinding apparatuses manufactured by EBARA CORPORATION (models: EPO-111, EPO-222, F-REX200, and F-REX300) and grinding apparatuses manufactured by Applied Materials, Inc. (product names: Mirra3400 and Reflexion). There are no particular limitations on the constituent materials of the grinding pad; for example, general non-woven fabric, foamed polyurethane, porous fluoropolymer, etc., can be used. Furthermore, the grinding pad can be grooved to retain the grinding fluid.

[0104] There are no particular limitations on the grinding conditions. From the viewpoint of preventing substrate splashing, the rotation speed of the grinding platform can be 200 min⁻¹ or less. From the viewpoint of easily suppressing grinding scratches on the ground surface, the pressure (processing load) applied to the substrate can be 100 kPa or less. During grinding, grinding fluid can be continuously supplied to the grinding pad by means of a pump or the like. There is no limit to the amount supplied, and the surface of the grinding pad can always be covered with grinding fluid. After grinding is completed, the substrate can be thoroughly washed with running water, and then dried using a spin dryer or the like to remove water droplets adhering to the substrate.

[0105] By grinding in the manner described above, surface irregularities can be eliminated, and a smooth surface can be obtained throughout the entire substrate. Furthermore, a structure with the desired number of layers can be manufactured by repeating the steps of forming the film and grinding the film a predetermined number of times.

[0106] The substrate (structure) 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 made of glass and crystalline materials; end faces of optical fibers; optical single crystals such as scintillators; solid-state laser single crystals; sapphire substrates for blue laser LEDs; semiconductor single crystals such as SiC, GaP, and GaAs; glass substrates for magnetic disks; and magnetic heads.

[0107] <Manufacturing Method, etc.> The manufacturing method of the part according to this embodiment includes a part fabrication step of obtaining the part by polishing a substrate (a component to be polished) using the polishing method of this embodiment. The part of this embodiment is a part obtained by the manufacturing method of the part according to this embodiment. The part of this embodiment is not particularly limited and may be an electronic part (e.g., a semiconductor component such as a semiconductor package), a wafer (e.g., a semiconductor wafer), or a chip (e.g., a semiconductor chip). As one aspect of the manufacturing method of the part according to this embodiment, in the manufacturing method of the electronic part according to this embodiment, the electronic part is obtained by polishing a substrate using the polishing method of this embodiment. As one aspect of the manufacturing method of the part according to this embodiment, in the manufacturing method of the semiconductor part according to this embodiment, the semiconductor part (e.g., a semiconductor package) is obtained by polishing a substrate using the polishing method of this embodiment. The manufacturing method of the part according to this embodiment may include a polishing step of polishing the substrate using the polishing method of this embodiment before the part fabrication step.

[0108] As one aspect of the part manufacturing method of this embodiment, the method may include a wafering step of wafering the substrate (the component being polished) polished by the polishing method of this embodiment. The wafering step may, for example, be a step of cutting the wafer (e.g., a semiconductor wafer) polished by the polishing method of this embodiment to obtain a wafer (e.g., a semiconductor wafer). As one aspect of the part manufacturing method of this embodiment, the method of manufacturing an electronic part of this embodiment may include a step of wafering the substrate polished by the polishing method of this embodiment to obtain an electronic part (e.g., a semiconductor part). As one aspect of the part manufacturing method of this embodiment, the method of manufacturing a semiconductor part of this embodiment may include a step of wafering the substrate polished by the polishing method of this embodiment to obtain a semiconductor part (e.g., a semiconductor package).

[0109] The manufacturing method of the part according to this embodiment, as one aspect of the part manufacturing process, may include a connection step in which a substrate (the component being ground) ground by the grinding method of this embodiment is connected to other connected bodies (e.g., electrically connected). The connected body to the substrate ground by the grinding method of this embodiment is not particularly limited; it may be the substrate ground by the grinding method of this embodiment, or it may be a different connected body from the substrate ground by the grinding method of this embodiment. In the connection step, the substrate and the connected body may be directly connected (connected in a state of contact), or the substrate and the connected body may be connected via other components (conductive components, etc.). The connection step can be performed before, after, or both before and after the monolithization step.

[0110] The connection step can be a step of connecting the polished surface of the substrate and the connected body polished by the polishing method of this embodiment, or it can be a step of connecting the connecting surface of the substrate and the connecting surface of the connected body polished by the polishing method of this embodiment. The connecting surface of the substrate can be the polished surface polished by the polishing method of this embodiment. The connecting step can provide a connected body having a substrate and a connected body. In the connection step, if the connecting surface of the substrate has a metal portion, the metal portion can be brought into contact with the connected body. In the connection step, if both the connecting surface of the substrate and the connecting surface of the connected body have metal portions, the metal portions can be brought into contact with each other. The metal portion can include copper.

[0111] The apparatus of this embodiment (e.g., an electronic device such as a semiconductor device) includes a substrate polished by the polishing method of this embodiment and at least one selected from the group consisting of parts of this embodiment. [Example]

[0112] Hereinafter, the present disclosure will be described in further detail with reference to the embodiments, but the present disclosure is not limited to these embodiments.

[0113] <Preparation of Cerium Oxide Powder> 40 kg of cerium carbonate hydrate was divided into 10 aluminum containers and calcined at 830°C in air for 2 hours, yielding 20 kg of yellowish-white powder. X-ray diffraction analysis confirmed the presence of polycrystalline cerium oxide in the powder. SEM observation of the particle size of the calcined powder showed a 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 milled cerium oxide powder was 9.4 m² / g. The 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. Then, 0.5 kg of 1M (mol / L, approximately 6% by mass) acetic acid was added, and the mixture was stirred for 10 minutes to obtain a cerium oxide mixture. The cerium oxide mixture was transferred to another container over 30 minutes. During this period, the cerium oxide mixture was ultrasonically irradiated at an ultrasonic frequency of 400 kHz in the transfer piping.

[0115] 500g ± 5g of the above-mentioned cerium oxide mixture, which had been ultrasonically irradiated and then dispensed, were placed into four 500mL polyethylene containers. The cerium oxide mixture in each container was centrifuged for 2 minutes under a centrifugal force of 500G at the periphery. After centrifugation, the supernatant fractions from the containers were collected to obtain a slurry. The slurry contained approximately 6.0% by mass of cerium oxide particles (abrasive particles A) based on the total mass.

[0116] 500g ± 5g of the above-mentioned cerium oxide mixture, which had been ultrasonically irradiated and then dispensed, were placed into four 500mL polyethylene containers. The cerium oxide mixture in each container was centrifuged for 5 minutes at a peripheral centrifugal force of 1200G. After centrifugation, the supernatant fractions were collected to obtain a slurry. The slurry contained approximately 2.0% by mass of cerium oxide particles (abrasive particles B) based on the total mass.

[0117] A sample for particle size measurement was obtained by diluting the slurry with pure water to make the content of abrasive particles 0.25% by mass based on the total mass. Regarding this sample, the average particle size of the abrasive particles was measured using a laser diffraction-scattering particle size distribution measuring device (manufactured by MicrotracBEL Corp., product name: Microtrac MT3300EXII). The average particle size of abrasive particle A was 140 nm, and the average particle size of abrasive particle B was 120 nm.

[0118] <Preparation of CMP Polishing Fluid> Polishing fluids having the compositions (remainder: deionized water) shown in the following tables were obtained by mixing the above slurry, each additive, and deionized water according to the following steps. In the tables, "THEED" refers to 2,2',2'',2'''-ethylenediaminetetraethanol, and "EDTP" refers to 1,1',1'',1'''-ethylenediaminetetra-2-propanol. In the examples other than Examples 3 and 8, and in the comparative examples, abrasive particle A was used, while abrasive particle B was used in Examples 3 and 8. Each polishing fluid, as acetic acid mixed during the preparation of the above slurry, contains an amount of acetic acid corresponding to the content of each abrasive particle. In addition, the pH of the 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, after mixing the above slurry and additive solution in equal amounts, a concentrated grinding slurry stock solution containing 5.0% by mass of abrasive particles was obtained by stirring for 10 minutes. The grinding slurry stock solution contains 20 times the amount of abrasive particles and additives relative to the final grinding slurry's abrasive particle content of 0.25% by mass, and 5 times the amount of abrasive particles and additives relative to the final grinding slurry's abrasive particle content of 1.00% by mass.

[0120] <Zeta Potential Measurement> An appropriate amount of polishing slurry was added to "DelsaNano C" manufactured by Beckman Coulter, Inc., and the zeta potential was measured twice at 25°C. The average value of the expressed zeta potential was taken as the zeta potential. In all embodiments and comparative examples, the zeta potential of the polishing particles was positive.

[0121] Furthermore, by diluting the grinding slurry with the stock solution to 20 times using deionized water, grinding slurries of the embodiments other than Examples 6, 9, 10, 31-35, and 38, and grinding slurries of the comparative examples were obtained. Also, by diluting the grinding slurry with the stock solution to 5 times using deionized water, grinding slurries of Examples 6, 9, 10, 31-35, and 38 were obtained. In the grinding slurries of each embodiment, the average particle size of the abrasive particles when the abrasive particle content is 0.25% by mass (adjusted to 0.25% by mass for a grinding slurry with an abrasive particle content of 1.00% by mass) is the same as the average particle size of the abrasive particles in the above-mentioned slurry.

[0122] <pH Measurement> (pH of the grinding slurry) The pH of the grinding slurry was measured under the following conditions. The results are shown in the tables. Measurement temperature: 25℃ Measurement device: Product name of HORIBA, Ltd.: Model (D-71) Measurement method: Phthalate pH standard solution (pH: 4.01), neutral phosphate pH standard solution (pH: 6.86), and borate pH standard solution (pH: 9.18) were used as pH standard solutions. After the pH meter was calibrated at 3 points, the electrode of the pH meter was placed in the grinding slurry, and the pH was measured after more than 2 minutes and stabilized using the aforementioned measuring device.

[0123] (pH of a 1 mM solution of additive B1) A 1 mM (millimole concentration) solution was prepared by dissolving additive B1 from the table in deionized water. The pH of the solution was measured using the same procedure as for the pH of the grinding solution. The results are shown in the respective tables.

[0124] <Evaluation of grinding characteristics> (Preparation of evaluation wafers) As a control wafer (BKW), a patternless wafer with a diameter of 200 mm and a diameter of 200 mm with a silicon oxide film (SiO2, initial film thickness: 1000 nm) and a patternless wafer with a diameter of 200 mm and a silicon nitride film (SiN, initial film thickness: 200 nm) were prepared.

[0125] As a patterned wafer (PTW), a test patterned wafer (model: Sematech 864, manufactured by ADVANTEC CO.,LTD., φ200mm) with a silicon oxide film (initial film thickness: 600nm) having a raised pattern on its surface is prepared. The raised portion (line portion) has an initial step height of 500nm higher than the recessed portion (space portion). Considering the evaluation for shallow trench isolation, the raised portion has a silicon nitride film (initial film thickness: 140nm) as the termination layer of the silicon oxide film substrate. The patterned wafer has a plurality of 20mm×20mm module units, and each module unit has a plurality of 4mm×4mm unit regions. The patterned wafer, as a 4mm × 4mm unit region, has a region of parallel line patterns with a spacing of 100μm and a line / space (L / S) increment of 10μm, ranging from 10μm / 90μm (protrusion density: 10%) to 90μm / 10μm (protrusion density: 90%). The patterned wafer, as a 4mm × 4mm unit region, also has 4mm × 4mm square protrusion patterns (protrusion density: 100%) and 4mm × 4mm square concave patterns (protrusion density: 0%).

[0126] (Grinding Steps) The above-mentioned evaluation wafer was ground using a grinding apparatus (manufactured by Applied Materials, Inc., product name: Mirra3400). The above-mentioned evaluation wafer was mounted on a holder with a substrate mounting pad. A porous urethane resin grinding pad (K-groove, manufactured by DuPont (Dow), model: IC-1010) was adhered to a grinding platform with a diameter of 500 mm.

[0127] Place the above-mentioned evaluation wafer with the polished surface facing down and place the above-mentioned support on the polishing pad. The inner tube pressure, the retaining ring pressure, and the membrane pressure are set to 14 kPa, 21 kPa, and 14 kPa, respectively.

[0128] Furthermore, while adding the polishing slurry dropwise at a flow rate of 200 mL / min to the polishing pad adhered to the polishing platform, the polishing platform and the evaluation wafer were rotated for 93 min⁻¹ and 87 min⁻¹, respectively, to polish the surface to be polished. In the control wafer, polishing was performed for 30 seconds. In the patterned wafer, based on the polishing speed used for evaluation with the control wafer, the polishing time was set to the time during which the silicon nitride film on the substrate of the silicon oxide film in the protrusion of the L / S=20 μm / 80 μm region was not exposed within the range of 20 to 60 seconds, and polishing was performed at this time. Next, the polished evaluation wafer was thoroughly cleaned with pure water using a PVA brush (polyvinyl alcohol brush) and then dried.

[0129] (Evaluation of Grinding Speed) The grinding speed was obtained by measuring the change in film thickness before and after grinding using an optical interferometric film thickness measuring device (manufactured by Nanometrics, Inc., product name: AFT-5100), as shown below. The results are presented in the tables.

[0130] In the control-coated wafer, the film thickness change is measured at a total of 41 points (20 points on each side of the center point) at the center point and at points 5 mm radially from the center point (the next measurement point after the center point at a distance of 95 mm from the center is set at a distance of 97 mm from the center). The film thickness change is measured at these 41 points over a 30-second grinding time, and the average value is used as the grinding speed of the control-coated wafer.

[0131] In a patterned wafer, the film thickness variation in the convex regions of L / S=20μm / 80μm, the convex regions of L / S=30μm / 70μm, the square convex pattern (convex density: 100%), and the square concave pattern (convex density: 0%) was measured to obtain the grinding speed of the patterned wafer. In the central module unit (20mm×20mm) of the patterned wafer, the film thickness variation at the central part 1 of one unit region (4mm×4mm) of the target pattern was measured.

[0132] [Table 1] Example 1 2 3 4 5 6 abrasive particles Content [mass%] 0.25 0.25 0.25 0.25 0.25 1.00 Additive A type maltol maltol maltol maltol maltol maltol Content [mass%] 0.034 0.034 0.034 0.034 0.034 0.136 Additive B1 type THEED THEED THEED THEED THEED THEED pH of 1mM solution 10.2 10.2 10.2 10.2 10.2 10.2 Content [mass%] 0.03 0.03 0.03 0.03 0.03 0.11 Additive B2 type o-aminobenzoic acid Quinalidone Quinalidone niacin Mandelic acid o-aminobenzoic acid Content [mass%] 0.04 0.04 0.04 0.04 0.04 0.08 propionic acid Content [mass%] 0.045 0.045 0.045 0.045 0.045 0.18 Average particle size [nm] 140 140 120 140 140 140 pH 4.55 4.45 4.60 4.50 4.10 4.55 Grinding speed [nm / min] BKW SiO2 479 490 196 540 400 406 SiN 0.3 0.2 0.2 0.5 0.2 1.6 PTW L / S=20 / 80 1282 1050 735 900 880 1376 L / S=30 / 70 1087 980 588 670 820 1313 convex part 100% 492 450 180 410 310 493 convex part 0% 431 400 160 400 300 439 Grinding speed ratio Protrusion 100% / Protrusion 0% 1.14 1.13 1.13 1.03 1.03 1.12

[0133] [Table 2] Example 7 8 9 10 11 12 13 abrasive particles Content [mass%] 0.25 0.25 1.00 1.00 0.25 0.25 0.25 Additive A type maltol maltol maltol maltol maltol maltol Kojic acid Content [mass%] 0.034 0.034 0.100 0.200 0.034 0.034 0.050 Additive B1 type THEED THEED THEED THEED EDTP L-histidine L-histidine pH of 1mM solution 10.2 10.2 10.2 10.2 9.8 7.5 7.5 Content [mass%] 0.03 0.03 0.02 0.02 0.05 0.04 0.04 Additive B2 type - - - - - - - propionic acid Content [mass%] 0.045 0.045 - - 0.045 0.045 0.045 Average particle size [nm] 140 120 140 140 140 140 140 pH 4.60 4.60 7.30 5.60 4.60 4.68 4.28 Grinding speed [nm / min] BKW SiO2 460 184 687 275 493 484 490 SiN 0.3 0.5 105 103 0.1 0.3 0.3 PTW L / S=20 / 80 996 697 1200 694 893 916 920 L / S=30 / 70 890 534 1120 620 702 834 840 convex part 100% 411 164 510 128 417 511 490 convex part 0% 343 137 490 188 288 352 340 Grinding speed ratio Protrusion 100% / Protrusion 0% 1.20 1.20 1.04 0.68 1.45 1.45 1.44

[0134] [Table 3] Implementation Examples 14 15 16 17 18 19 abrasive particles Content [mass%] 0.25 0.25 0.25 0.25 0.25 0.25 Additive A type maltol maltol maltol maltol maltol maltol Content [mass%] 0.034 0.034 0.034 0.034 0.034 0.034 Additive B1 type imidazole imidazole L-glutamic acid L-glutamic acid 3-Hydroxypyridine 4-Hydroxypyridine pH of 1mM solution 8.6 8.6 3.8 5.5 6.7 6.2 Content [mass%] 0.02 0.04 0.04 0.08 0.04 0.05 Additive B2 type - - - - - - propionic acid Content [mass%] 0.045 0.045 0.045 0.045 0.045 0.045 Average particle size [nm] 140 140 140 140 140 140 pH 4.82 5.99 3.52 3.75 4.76 4.17 Grinding speed [nm / min] BKW SiO2 409 422 299 378 458 448 SiN 0.3 45 0.5 0.3 0.6 0.3 PTW L / S=20 / 80 844 793 565 904 949 915 L / S=30 / 70 714 632 421 714 866 742 convex part 100% 323 354 278 303 337 468 convex part 0% 290 291 271 322 308 359 Grinding speed ratio Protrusion 100% / Protrusion 0% 1.11 1.22 1.03 0.94 1.09 1.30

[0135] [Table 4] Example 20 twenty one twenty two twenty three twenty four 25 abrasive particles Content [mass%] 0.25 0.25 0.25 0.25 0.25 0.25 Additive A type maltol maltol maltol maltol maltol maltol Content [mass%] 0.034 0.034 0.034 0.034 0.034 0.034 Additive B1 type L-proline aminoacetic acid Hydroxyethylglycine 2-Methylimidazole 2-Pyridineethanol L-tyrosine pH of 1mM solution 5.8 5.9 5.5 9.2 7.2 5.5 Content [mass%] 0.04 0.31 0.05 0.02 0.04 0.04 Additive B2 type - - - - - - propionic acid Content [mass%] 0.045 0.045 0.045 0.045 0.045 0.045 Average particle size [nm] 140 140 140 140 140 140 pH 3.74 4.50 3.73 4.68 4.75 3.71 Grinding speed [nm / min] BKW SiO2 433 504 444 366 407 451 SiN 0.5 0.2 0.3 0.2 0.2 0.1 PTW L / S=20 / 80 935 901 843 813 811 810 L / S=30 / 70 757 757 714 698 677 803 convex part 100% 449 441 362 297 330 391 convex part 0% 378 434 322 232 263 385 Grinding speed ratio Protrusion 100% / Protrusion 0% 1.19 1.02 1.12 1.28 1.25 1.02

[0136] [Table 5] Implementation Examples Comparative example 26 27 28 29 1 2 abrasive particles Content [mass %] 0.25 0.25 0.25 0.25 0.25 0.25 Additive A Kind maltol maltol maltol maltol - maltol Content [mass%] 0.034 0.034 0.034 0.034 0.034 Additives such as B1 type L-cysteine L-alanine L-Serine Triethanolamine L-glutamic acid L-Aspartic acid pH of 1mM solution 5.6 5.6 5.4 9.4 5.5 3.6 Content [mass%] 0.04 0.04 0.08 0.04 0.08 0.04 Additive B2 type - - - - - - Content [mass%] propionic acid Content [mass%] 0.045 0.045 0.045 0.045 0.045 0.045 Average particle size [nm] 140 140 140 140 140 140 pH 3.74 3.73 3.75 4.79 3.72 3.34 Grinding speed [nm / min] BKW SiO2 468 509 455 406 182 214 SiN 0.5 0.2 0.1 0.4 0.2 0.3 PTW L / S=20 / 80 933 885 797 1032 135 256 L / S=30 / 70 737 838 732 938 94 196 convex part 100% 366 489 405 270 60 209 convex part 0% 411 492 412 245 76 185 Grinding speed ratio Protrusion 100% / Protrusion 0% 0.89 0.99 0.98 1.10 0.79 1.13

[0137] [Table 6] Implementation Examples 30 31 32 33 34 35 abrasive particles Content [mass%] 0.25 1.00 1.00 1.00 1.00 1.00 Additive A type - - - - - - Additive B1 type THEED THEED THEED THEED EDTP EDTP pH of 1mM solution 10.2 10.2 10.2 10.2 9.8 9.8 Content [mass%] 0.03 0.05 0.13 0.22 0.02 0.03 Additive B2 type - Pyridinecarboxylic acid Pyridinecarboxylic acid Pyridinecarboxylic acid Pyridinecarboxylic acid Pyridinecarboxylic acid Content [mass%] 0.20 0.20 0.20 0.20 0.20 propionic acid Content [mass%] 0.425 - - - - - Average particle size [nm] 140 140 140 140 140 140 pH 3.65 4.60 5.10 5.60 4.10 4.30 Grinding speed [nm / min] BKW SiO2 231 516 500 494 543 455 SiN 0.4 13 14 19 9.2 11 PTW L / S=20 / 80 369 1231 1091 1144 1080 876 L / S=30 / 70 184 1123 856 1083 1156 938 convex part 100% 100 418 317 337 301 180 convex part 0% 97 446 317 420 273 183 Grinding speed ratio Protrusion 100% / Protrusion 0% 1.03 0.94 1.00 0.80 1.10 0.99

[0138] [Table 7] Example 36 37 38 39 40 abrasive particles Content [mass%] 0.25 0.25 1.00 0.25 0.25 Additive A type maltol maltol maltol maltol maltol Content [mass%] 0.034 0.034 0.136 0.034 0.034 Additive B1 type - - - - - Additive B2 type o-aminobenzoic acid o-aminobenzoic acid o-aminobenzoic acid Quinalidone benzoic acid Content [mass%] 0.04 0.04 0.08 0.04 0.01 propionic acid Content [mass%] - 0.045 0.18 0.045 0.045 Average particle size [nm] 140 140 140 140 140 pH 4.70 3.70 3.57 3.54 3.50 Grinding speed [nm / min] BKW SiO2 490 474 430 480 441 SiN 1.5 0.2 1.1 0.5 0.2 PTW L / S=20 / 80 1250 1205 1300 960 794 L / S=30 / 70 1050 1001 1061 901 749 convex part 100% 375 402 577 361 458 convex part 0% 335 385 554 350 427 Grinding speed ratio Protrusion 100% / Protrusion 0% 1.12 1.04 1.04 1.03 1.07

[0139] [Table 8] Example 41 42 43 44 45 abrasive particles Content [mass%] 0.25 0.25 0.25 0.25 0.25 Additive A type maltol maltol maltol maltol maltol Content [mass%] 0.034 0.034 0.034 0.034 0.034 Additive B1 type - - - - - Additive B2 type 4-Hydroxybenzoic acid Pyridinecarboxylic acid Pyridinecarboxylic acid Phthalic acid salicylic acid Content [mass%] 0.02 0.04 0.08 0.02 0.02 propionic acid Content [mass%] 0.045 0.045 0.045 0.045 0.045 Average particle size [nm] 140 140 140 140 140 pH 3.60 3.65 3.60 3.24 3.10 Grinding speed [nm / min] BKW SiO2 472 458 463 244 141 SiN 0.2 0.3 0.3 0.4 0.5 PTW L / S=20 / 80 854 838 912 742 650 L / S=30 / 70 711 824 791 730 620 convex part 100% 413 404 563 260 120 convex part 0% 404 402 402 250 130 Grinding speed ratio Protrusion 100% / Protrusion 0% 1.02 1.00 1.40 1.04 0.92

[0140] The relationship between the grinding speed of silicon oxide in the protrusion (Line portion) in the L / S=20μm / 80μm ​​region and the relationship between the grinding speed of silicon oxide in the control wafer are different. However, in all embodiments, it has been confirmed that while achieving a high grinding speed of silicon oxide in the control wafer, a high grinding speed (e.g., ≥300nm / min) of silicon oxide in the protrusion in the L / S=20μm / 80μm ​​region is also obtained.

[0141] In some embodiments, sufficiently low polishing speeds (e.g., <2.0 nm / min) are obtained for silicon nitride in the control wafer, and sometimes particularly low polishing speeds (e.g., <1.0 nm / min) are obtained for silicon nitride. In all embodiments, high polishing speeds are obtained for the convex portions (Line portions) in the L / S = 30 μm / 70 μm region. The polishing speed of 0% of the convex portion is an indicator of the recess characteristics, and in some embodiments, sufficiently low polishing speeds (e.g., ≤300 nm / min) can be obtained. The polishing speed ratio of 100% of the convex portion to 0% of the convex portion is an indicator of planarization efficiency, and in some embodiments, a better polishing speed ratio (e.g., >1.0) is obtained.

[0142] The present inventors have described the best mode of implementing this disclosure in the specification. Those skilled in the art, upon reading the above description, may also recognize similar variations. The present inventors are also fully aware of different implementations of this disclosure, as well as similar implementations to which the principles of this disclosure apply. Furthermore, in this disclosure, as its principle, all variations of the contents listed in the specification and any combination of the aforementioned elements can be utilized. No particular limitation is placed on any possible combination thereof in this specification, or unless explicitly denied by context, it is included in this disclosure. [Simplified Explanation of the Diagram]

[0011] Figure 1 is a schematic cross-sectional view showing the process of grinding the ILD membrane.

Claims

1. A CMP polishing slurry comprising abrasive particles, an additive, and water, wherein the abrasive particles comprise cerium-based particles, the additive comprises a compound having two or more nitrogen atoms bonded to a hydroxyl alkyl group, and the pH of the CMP polishing slurry is less than 9.

0.

2. The CMP polishing slurry as claimed in claim 1, wherein the compound having two or more nitrogen atoms bonded to the aforementioned hydroxyalkyl group comprises ethylenediaminetetraethanol.

3. The CMP polishing slurry as described in claim 1 or 2, wherein the pH of the CMP polishing slurry is below 8.

0.

4. The CMP polishing slurry as described in claim 1 or 2, wherein the aforementioned cerium-based particles comprise cerium oxide.

5. The CMP polishing slurry as described in claim 1 or 2, wherein the content of the aforementioned polishing particles is 0.01 to 10% by mass.

6. The CMP slurry as described in claim 1 or 2, wherein the aforementioned additive further comprises a saturated monocarboxylic acid.

7. The CMP polishing slurry as described in claim 6, wherein the content of the aforementioned saturated monocarboxylic acid is 0.0001 to 5% by mass.

8. A CMP polishing slurry kit, wherein the components of the CMP polishing slurry described in any one of claims 1 to 7 are stored in a first liquid and a second liquid, wherein the first liquid contains the aforementioned abrasive particles and water, and the aforementioned second liquid contains at least one of the aforementioned additives and water.

9. A polishing method comprising the step of polishing a surface to be polished using a CMP polishing slurry as described in any one of claims 1 to 7.

10. The polishing method as described in claim 9, wherein the polished surface comprises silicon oxide.

11. A polishing method comprising the step of polishing a surface to be polished using a CMP polishing slurry obtained by mixing the aforementioned first liquid and the aforementioned second liquid in the CMP polishing slurry kit of claim 8.

12. The polishing method as described in claim 11, wherein the polished surface comprises silicon oxide.

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