Abrasive liquid, abrasive liquid set, polishing method, and defect suppression method

Abstract

A polishing liquid contains abrasive grains including at least one selected from the group consisting of cerium oxide and silicon oxide, a nitrogen-containing compound, and water. The nitrogen-containing compound contains at least one selected from the group consisting of the following compounds: (I) a compound having an aromatic ring with one nitrogen atom in the ring and a hydroxyl group; (II) a compound having an aromatic ring with one nitrogen atom in the ring and a functional group containing a nitrogen atom; (III) a compound having a 6-membered ring with two nitrogen atoms in the ring; (IV) a compound having a benzene ring and a ring with a nitrogen atom in the ring; and (V) a benzene ring having a functional group bonded with two or more nitrogen atoms.

Description

Technical Field

[0001] The present invention relates to a polishing liquid, a polishing liquid set, and a polishing method and a defect suppression method using the polishing liquid or the polishing liquid set. More specifically, the present invention relates to a polishing liquid, a polishing liquid set used in a substrate surface flattening process (particularly a flattening process of an interlayer insulating film, a BPSG film (boron and phosphorus doped silicon dioxide film), etc., a shallow trench isolation (STI) forming process, etc.) as a manufacturing technology for semiconductor elements, and a polishing method and a defect suppression method using the polishing liquid or the polishing liquid set. Background Art

[0002] In the current manufacturing process of ULSI semiconductor elements, research and development of processing technologies for high density and miniaturization of semiconductor elements are being conducted. As one of the processing technologies, the planarization technology based on CMP (Chemical mechanical polishing) is becoming a necessary technology for planarization of interlayer insulating films, STI formation process, plug formation process, buried metal wiring formation process (embedding process), etc. in the manufacturing process of semiconductor elements. The CMP process (planarization process using CMP technology) is generally performed by supplying CMP polishing liquid between the polishing pad (polishing cloth) and the polishing material of the substrate while polishing the polishing material.

[0003] In the CMP process, there is a case where an insulating material is selectively ground using a stopper (a grinding stopper layer including a stopper material). In this case, when the insulating material to be ground is ground and the stopper is exposed, it is necessary to stop the material without grinding the stopper. Polycrystalline silicon, amorphous silicon, single crystal silicon, etc. are being studied as stopper materials. In this case, for the CMP polishing liquid, it is necessary to suppress the grinding speed of the stopper material as much as possible, and the grinding speed ratio of the insulating material relative to the stopper material (grinding selectivity: grinding speed of the insulating material / grinding speed of the stopper material) is higher (for example, refer to the following patent document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 4872919 Summary of the invention

[0007] Problems to be solved by the invention

[0008] The stopper material is sometimes used as a conductive material for semiconductor devices (gates of transistors, etc.). In this case, after the CMP process, when defects (such as recessed defects such as holes) are generated on the stopper due to chemical reactions, the reliability of the semiconductor device is greatly affected, so it is necessary to suppress the generation of defects on the stopper as much as possible. However, with the further high density and miniaturization of semiconductor elements, it is not easy to suppress the generation of defects on the stopper in the previous technology, especially it is not easy to suppress the generation of defects on the stopper of silicon materials (except silicon oxide) such as polycrystalline silicon, amorphous silicon, and single crystal silicon.

[0009] The present invention aims to solve the above-mentioned problems and aims to provide a polishing liquid and a polishing liquid set which can suppress the generation of defects in the polishing of a polished surface containing a silicon material (excluding silicon oxide). In addition, the present invention aims to provide a polishing method and a defect suppression method using the polishing liquid or the polishing liquid set.

[0010] Means for solving problems

[0011] The present inventors have conducted intensive research on the components of the polishing liquid in order to solve the above problems. As a result, the present inventors have found that the generation of defects can be suppressed during the polishing of the polished surface containing silicon material (excluding silicon oxide) by using a specific additive.

[0012] The polishing liquid of the present invention comprises: abrasive grains containing at least one selected from the group consisting of cerium oxide and silicon oxide, a nitrogen-containing compound and water, wherein the nitrogen-containing compound comprises at least one selected from the group consisting of the following compounds: (I) a compound having an aromatic ring containing one nitrogen atom in the ring and a hydroxyl group, (II) a compound having an aromatic ring containing one nitrogen atom in the ring and a functional group containing a nitrogen atom, (III) a compound having a six-membered ring containing two nitrogen atoms in the ring, (IV) a compound having a benzene ring and a ring containing a nitrogen atom in the ring, and (V) a compound having a benzene ring to which two or more functional groups containing nitrogen atoms are bonded.

[0013] According to the polishing liquid of the present invention, the generation of defects, particularly the generation of defects due to chemical reactions, can be suppressed during the polishing of a surface to be polished containing a silicon material (excluding silicon oxide).

[0014] The nitrogen-containing compound preferably comprises the compound (II). The nitrogen-containing compound preferably comprises the compound (III). The nitrogen-containing compound preferably comprises nicotinamide. The nitrogen-containing compound preferably comprises aminopyridine. The nitrogen-containing compound preferably comprises pyrazinamide.

[0015] The polishing liquid according to the present invention may further contain a polymer compound (A) having at least one selected from the group consisting of a carboxyl group and a carboxylate group. The content of the polymer compound (A) is preferably 0.001 to 2% by mass.

[0016] The polishing liquid according to the present invention may further contain a nonionic polymer compound (B).

[0017] The polishing liquid according to the present invention may further contain a basic compound. The content of the basic compound is preferably 0.04 mol / kg or less.

[0018] The abrasive grains preferably contain cerium oxide. The abrasive grains may contain silicon oxide. The content of the abrasive grains is preferably 0.01 to 20% by mass.

[0019] The pH of the polishing liquid according to the present invention is preferably 4.0 to 7.5. The pH of the polishing liquid according to the present invention preferably exceeds 4.0.

[0020] In the polishing liquid kit according to the present invention, the components of the polishing liquid according to the present invention are stored separately as a first liquid and a second liquid. The first liquid contains the abrasive grains and water, and the second liquid contains the nitrogen-containing compound and water.

[0021] The polishing method according to the present invention includes a step of polishing a surface to be polished using the polishing liquid according to the present invention or a polishing liquid obtained by mixing the first liquid and the second liquid in the polishing liquid kit according to the present invention. The surface to be polished may contain at least one selected from the group consisting of polysilicon, amorphous silicon, and single crystal silicon. The surface to be polished may contain amorphous silicon.

[0022] The defect suppression method according to the present invention is a defect suppression method for suppressing defects generated during polishing of a surface to be polished including a stop portion material, and includes a step of polishing the surface to be polished using the polishing liquid according to the present invention or a polishing liquid obtained by mixing the first liquid and the second liquid in the polishing liquid kit according to the present invention. The stop portion material may contain at least one selected from the group consisting of polysilicon, amorphous silicon, and single crystal silicon. The stop portion material may contain amorphous silicon.

[0023] Effects of the Invention

[0024] According to the present invention, generation of defects can be suppressed during polishing of a surface to be polished containing a silicon material (excluding silicon oxide), and in particular, generation of defects based on chemical action can be suppressed. According to the present invention, an application of the polishing liquid in a defect suppression method for suppressing generation of defects during polishing of a surface to be polished containing a silicon material (excluding silicon oxide) can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 ​is a diagram showing an example of a defect.

[0026] Figure 2 is a schematic cross-sectional view showing a polishing method according to an embodiment of the present invention.

[0027] Symbol Explanation

[0028] 1... wafer, 2... stop portion, 3... insulating member, 4... depth, 5... thickness, 6... dishing defect amount, 100, 200... substrate. Detailed Embodiment

[0029] Hereinafter, embodiments of the present invention will be described in detail.

[0030] <Definition>

[0031] In this specification, the term "process" not only refers to an independent process, but also includes this term even when it cannot be clearly distinguished from other processes as long as the intended function of the process can be achieved. A numerical range represented by "~" means a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value of a certain step's numerical range can be arbitrarily combined with the upper limit value or the lower limit value of other step's numerical ranges. In the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range can be replaced with the values shown in the examples. The materials shown in this specification can be used alone or in combination of two or more without special mention. When there are multiple substances corresponding to each component in the composition, unless otherwise specified, the amount of each component in the composition refers to the total amount of the multiple substances present in the composition. "Polishing Rate" means the speed of removing the material per unit time (Removal Rate = Removal Rate). "A or B" means that either A or B can be included, or both can be included. "A or more" of a numerical range means A and a range exceeding A. "A or less" of a numerical range means A and a range less than A.

[0032] <Polishing Liquid>

[0033] The polishing liquid (polishing composition) according to this embodiment contains: abrasive grains containing at least one selected from the group consisting of cerium oxide and silicon oxide, a nitrogen-containing compound, and water. The polishing liquid according to this embodiment contains at least a nitrogen-containing compound as an additive other than the abrasive grains and water. The polishing liquid according to this embodiment can be used as a CMP polishing liquid.

[0034] According to the polishing liquid according to this embodiment, generation of defects can be suppressed in the polishing of a polished surface containing a silicon material (a material containing silicon. Excluding silicon oxide. The same applies hereinafter), and particularly generation of concave defects can be suppressed. For example, as​Figure 1 As shown, the concave defect is a depression such as a cavity formed on the ground surface after grinding, and is generated by chemical action. Examples of the silicon material include polycrystalline silicon, amorphous silicon, and single crystal silicon.

[0035] The grinding liquid according to the present embodiment can be used for grinding a silicon material used as a stopper material. The grinding liquid according to the present embodiment can be used to suppress grinding of at least one selected from the group consisting of polycrystalline silicon, amorphous silicon, and single crystal silicon.

[0036] The ground surface may contain other ground materials (e.g., insulating materials) in addition to the silicon material. The grinding liquid according to the present embodiment can be used for grinding an insulating material, and can also be used for grinding, for example, to expose the stopper portion by removing at least a part of the insulating material by CMP. Examples of the insulating material include insulating materials used for interlayer insulating films, BPSG films, STI films, etc.

[0037] (Abrasive grains)

[0038] The grinding liquid according to the present embodiment contains abrasive grains (grinding particles). The abrasive grains contain at least one selected from the group consisting of ceria and silica. That is, the abrasive grains may contain ceria or may contain silica. As the abrasive grains, ceria particles (particles containing ceria) can be used, or silica particles (particles containing silica) can be used. From the viewpoints of easily obtaining a good grinding rate of the insulating material and stable grinding rate of the insulating material, the abrasive grains preferably contain ceria.

[0039] As the ceria particles, colloidal ceria can also be used. The ceria particles can be particles in which the surface of the ceria particles is modified with an alkyl group, composite particles in which other particles are attached to the surface of the ceria particles, composite particles in which ceria particles are attached to the surface of other particles, etc.

[0040] The ceria particles are preferably obtained by oxidizing a cerium salt such as carbonate, nitrate, sulfate, or oxalate. As the oxidation method, there are a firing method in which the cerium salt is fired at about 600 to 900 °C, a chemical oxidation method in which the cerium salt is oxidized with an oxidant such as hydrogen peroxide, etc. As a method for manufacturing the ceria particles, from the viewpoint of easily obtaining a high grinding rate of the insulating material, the firing method is preferred, and from the viewpoint of hardly generating grinding scratches on the ground surface after grinding, the chemical oxidation method is preferred.

[0041] When using cerium oxide particles, the larger the microcrystalline diameter (diameter of microcrystals) of the cerium oxide particles and the less the crystal deformation, the higher the polishing speed can be, but there is a tendency for polishing scratches to be easily formed on the material to be polished. Based on the above viewpoints, as preferred cerium oxide particles, particles composed of two or more microcrystals and having grain boundaries can be cited. In addition, as other preferred cerium oxide particles, for example, colloidal cerium oxide particles with a microcrystalline diameter of 5 to 300 nm (for example, colloidal cerium oxide manufactured by Rhodia) can be cited.

[0042] From the viewpoint of easily obtaining a good polishing speed of the insulating material, the silicon oxide particles preferably contain at least one selected from the group consisting of colloidal silica and fumed silica, and more preferably contain colloidal silica. The silicon oxide particles can be particles in which the surface of the silicon oxide particles is modified with an alkyl group, composite particles in which other particles are attached to the surface of the silicon oxide particles, and the like.

[0043] When the abrasive grains contain cerium oxide, from the viewpoint of easily obtaining a good polishing speed of the insulating material, based on all the abrasive grains (all the abrasive grains contained in the polishing liquid. The same applies hereinafter), the content of cerium oxide in the abrasive grains is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 90% by mass or more, particularly preferably 95% by mass or more, extremely preferably 97% by mass or more, and very preferably 99% by mass or more. The abrasive grains containing cerium oxide can be in a form substantially composed of cerium oxide (a form in which 100% by mass of the abrasive grains is substantially cerium oxide).

[0044] When the abrasive grains contain silicon oxide, from the viewpoint of easily obtaining a good polishing speed of the insulating material, based on all the abrasive grains, the content of silicon oxide in the abrasive grains is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 90% by mass or more, particularly preferably 95% by mass or more, extremely preferably 97% by mass or more, and very preferably 99% by mass or more. The abrasive grains containing silicon oxide can be in a form substantially composed of silicon oxide (a form in which 100% by mass of the abrasive grains is substantially silicon oxide).

[0045] One type of abrasive grains can be used alone, or two or more types can be used in combination. The abrasive grains can contain components other than cerium oxide and silicon oxide. As components of the abrasive grains other than cerium oxide and silicon oxide, for example, at least one selected from the group consisting of cerium compounds (excluding cerium oxide), alumina (aluminum oxide), zirconia, titanium dioxide, germanium oxide, manganese oxide, magnesium oxide, resin, diamond, silicon carbide, cubic boron nitride, and their modified products can be cited.

[0046] Examples of cerium compounds include cerium hydroxide, cerium ammonium nitrate, cerium acetate, cerium sulfate hydrate, cerium bromate, cerium bromide, cerium chloride, cerium oxalate, cerium nitrate, cerium carbonate, etc. As the particles containing alumina, colloidal alumina can be used. The particles containing components other than cerium oxide and silicon oxide can be particles with their surfaces modified with an alkyl group; composite particles with other particles attached to their surfaces, etc.

[0047] The abrasive grains can be obtained by any manufacturing method. For example, as a manufacturing method of oxides, a solid-phase method such as using firing can be adopted; a liquid-phase method such as a precipitation method, a sol-gel method, a hydrothermal synthesis method, etc.; a gas-phase method such as a sputtering method, a laser method, a thermal plasma method, etc.

[0048] When the abrasive grains agglomerate, the agglomerated abrasive grains can be mechanically pulverized. As the pulverization method, a dry pulverization method based on, for example, a jet mill and a wet pulverization method based on a planetary bead mill are preferably used. The jet mill can be applied, for example, to the method described in "Journal of Chemical Engineering of Japan", Vol. 6, No. 5, (1980), pages 527 to 532.

[0049] An abrasive liquid can be obtained by dispersing the abrasive grains in water as a dispersion medium. As the dispersion method, in addition to the usual dispersion treatment based on a stirrer, methods such as using a homogenizer, an ultrasonic disperser, a wet ball mill, etc. can be cited. Regarding the dispersion method and the particle size control method, for example, the methods described in Chapter 3, "Latest Development Trends and Selection Criteria of Various Dispersers" of "Encyclopedia of Dispersion Technology" [Information and Media Co., Ltd., July 2005] can be used. In addition, by reducing the conductivity of the dispersion liquid containing the abrasive grains (for example, 500 mS / m or less), the dispersibility of the abrasive grains can also be improved. As a method for reducing the conductivity of the dispersion liquid, the following methods can be cited: a method of performing solid-liquid separation by centrifugation or the like to separate the abrasive grains from the dispersion medium, discarding the supernatant (dispersion medium), and then adding a dispersion medium with low conductivity to redisperse; a method of using ultrafiltration, an ion exchange resin, etc.

[0050] The abrasive grains dispersed by the above method can be further micronized. As the micronization method, for example, a sedimentation classification method (a method of centrifuging the abrasive grains with a centrifuge and then forcing them to settle, and only taking out the supernatant) can be cited. In addition, a high-pressure homogenizer that causes the abrasive grains in the dispersion medium to collide with each other under high pressure can also be used.

[0051] Based on the view that it is easy to obtain a good polishing rate of the insulating material, the average particle size of the abrasive grains is preferably 10 nm or more, more preferably 20 nm or more, further preferably 50 nm or more, particularly preferably 90 nm or more, extremely preferably more than 90 nm, very preferably 100 nm or more, and further preferably 130 nm or more, and still further preferably 150 nm or more. Based on the view that it is difficult to damage the material to be polished, the average particle size of the abrasive grains is preferably 500 nm or less, more preferably 400 nm or less, further preferably 300 nm or less, and particularly preferably 200 nm or less. Based on these views, the average particle size of the abrasive grains is preferably 10 - 500 nm, more preferably 20 - 400 nm, further preferably 50 - 300 nm, particularly preferably 90 - 300 nm, extremely preferably more than 90 nm and 300 nm or less, very preferably 100 - 300 nm, still further preferably 130 - 300 nm, and further preferably 150 - 200 nm.

[0052] The average particle size of the abrasive grains refers to, for example, the value of D50 (average secondary particle size, median diameter of volume distribution, cumulative median) of the measurement sample measured using a laser diffraction particle size distribution analyzer (manufactured by Horiba, Ltd., trade name: LA - 920, refractive index: 1.93, light source: He - Ne laser, absorption 0). In the measurement of the average particle size, a measurement sample with an appropriate content (for example, a content that makes the transmittance (H) 60 - 70% when measuring with a He - Ne laser) can be used. In addition, when the polishing liquid containing abrasive grains is stored as a slurry in which the abrasive grains are dispersed in water and an additive solution containing additives, the slurry can be diluted to an appropriate content for measurement.

[0053] Based on the total mass of the polishing liquid, the content of the abrasive grains is preferably in the following range. Based on the view that it is easy to ensure a sufficient polishing rate of the insulating material, the content of the abrasive grains is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, further preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, extremely preferably 0.4% by mass or more, and very preferably 0.5% by mass or more. Based on the view that it is easy to suppress the aggregation of the abrasive grains, the content of the abrasive grains is preferably 20% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, particularly preferably 3% by mass or less, and extremely preferably 1% by mass or less. Based on these views, the content of the abrasive grains is preferably 0.01 - 20% by mass, more preferably 0.05 - 10% by mass, further preferably 0.1 - 5% by mass, particularly preferably 0.2 - 3% by mass, extremely preferably 0.2 - 1% by mass, very preferably 0.4 - 1% by mass, and still further preferably 0.5 - 1% by mass.

[0054] (Additive)

[0055] [Nitrogen - containing compound]

[0056] The polishing liquid according to this embodiment contains a nitrogen-containing compound. The nitrogen-containing compound can act as a defect inhibitor. The nitrogen-containing compound contains at least one selected from the group consisting of (I) a compound having an aromatic ring containing one nitrogen atom in the ring and a hydroxyl group (hereinafter referred to as "compound (I)"), (II) a compound having an aromatic ring containing one nitrogen atom in the ring and a functional group containing a nitrogen atom (excluding the compounds equivalent to compound (I), hereinafter referred to as "compound (II)"), (III) a compound having a 6-membered ring containing two nitrogen atoms in the ring (excluding the compounds equivalent to compound (I) or compound (II), hereinafter referred to as "compound (III)"), (IV) a compound having a benzene ring and a ring containing a nitrogen atom in the ring (excluding the compounds equivalent to compound (I), compound (II) or compound (III), hereinafter referred to as "compound (IV)"), and (V) a compound having a benzene ring to which two or more functional groups containing a nitrogen atom are bonded (excluding the compounds equivalent to compound (I), compound (II), compound (III) or compound (IV), hereinafter referred to as "compound (V)"). The nitrogen-containing compound can be used alone or in combination of two or more.

[0057] According to the polishing liquid of this embodiment, by using the nitrogen-containing compound, generation of defects can be inhibited in polishing of a polished surface containing a silicon material, and in particular, generation of defects based on chemical action can be inhibited. The detailed reason for achieving such an effect is not necessarily clear, but the present inventors presume an example of the reason as follows. That is, it is presumed that hydroxyl groups exist on the surface of a silicon material such as polysilicon, amorphous silicon, and single crystal silicon. At this time, by using a compound capable of forming a hydrogen bond or a coordination bond with at least two or more hydroxyl groups of the silicon material, or a compound capable of strengthening the hydrogen bond or the coordination bond with the hydroxyl group of the silicon material, the surface of the silicon material is appropriately protected, and thus generation of defects is inhibited.

[0058] From the viewpoint of further inhibiting generation of defects, the number of nitrogen atoms in one molecule of the nitrogen-containing compound is preferably 1 to 4, more preferably 1 to 3. The number of the nitrogen atoms can be two or more.

[0059] Compound (I) is a compound having an aromatic ring containing one nitrogen atom in the ring and a hydroxyl group. It is presumed that the empty orbital of the nitrogen atom in the ring of compound (I) and the non-bonding electron pair of the oxygen atom of the hydroxyl group on the silicon material are coordinately bonded, and in addition, the hydroxyl group of compound (I) and the hydroxyl group of the silicon material are hydrogen-bonded, whereby the surface of the silicon material is appropriately protected. In addition, the hydroxyl group of compound (I) does not contain OH of a carboxyl group (COOH group). It is presumed that the hydrogen-bonding property of OH of the carboxyl group is lower than that of the hydroxyl group.

[0060] Examples of the aromatic ring include a 3-membered ring, a 4-membered ring, a 5-membered ring, a 6-membered ring, etc. From the viewpoint of further suppressing the generation of defects, a 6-membered ring is preferred. The aromatic ring is, for example, a heteroaromatic ring. Examples of the aromatic ring containing one nitrogen atom in the ring include an azole ring, a pyridine ring, an oxazole ring, a thiazole ring, a thiazine ring, etc. From the viewpoint of further suppressing the generation of defects, a pyridine ring is preferred.

[0061] The hydroxyl group of the compound (I) may be a hydroxyl group directly bonded to the aromatic ring or a hydroxyl group not directly bonded to the aromatic ring. From the viewpoint of further suppressing the generation of defects, the compound (I) preferably has a hydroxyl group directly bonded to the aromatic ring. From the viewpoint of further suppressing the generation of defects, the number of hydroxyl groups is preferably 1 to 3, more preferably 1 to 2, and still more preferably 1. From the viewpoint of further suppressing the generation of defects, the hydroxyl group preferably binds to a carbon atom adjacent to the nitrogen atom contained in the aromatic ring.

[0062] As the compound (I), from the viewpoint of further suppressing the generation of defects, hydroxypyridine is preferred. Examples of hydroxypyridine include 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, etc.

[0063] The compound (II) is a compound having an aromatic ring containing one nitrogen atom in the ring and a nitrogen atom-containing functional group. It is presumed that the empty orbital of the nitrogen atom in the ring of the compound (II) coordinates with the non-bonding electron pair of the oxygen atom of the hydroxyl group on the silicon material. In addition, the nitrogen atom-containing functional group of the compound (II) forms a hydrogen bond with the hydroxyl group of the silicon material, whereby the surface of the silicon material is appropriately protected.

[0064] Examples of the aromatic ring include a 3-membered ring, a 4-membered ring, a 5-membered ring, a 6-membered ring, etc. From the viewpoint of further suppressing the generation of defects, a 6-membered ring is preferred. The aromatic ring is, for example, a heteroaromatic ring. Examples of the aromatic ring containing one nitrogen atom in the ring include an azole ring, a pyridine ring, an oxazole ring, a thiazole ring, a thiazine ring, etc. From the viewpoint of further suppressing the generation of defects, a pyridine ring is preferred.

[0065] Examples of the nitrogen atom-containing functional group include an amino group, an amide group, a sulfonamide group, etc. From the viewpoint of further suppressing the generation of defects, at least one selected from the group consisting of an amino group and an amide group is preferred. The nitrogen atom-containing functional group may be a functional group directly bonded to the aromatic ring or a functional group not directly bonded to the aromatic ring. In the compound (II), from the viewpoint of further suppressing the generation of defects, as the nitrogen atom-containing functional group, a functional group directly bonded to the aromatic ring is preferred. From the viewpoint of further suppressing the generation of defects, the number of nitrogen atom-containing functional groups is preferably 1 to 3, more preferably 1 to 2, and still more preferably 1. From the viewpoint of further suppressing the generation of defects, the nitrogen atom-containing functional group preferably binds to a carbon atom at the 2-position or 3-position relative to the nitrogen atom at the 1-position contained in the aromatic ring.

[0066] As the compound (II), from the viewpoint of further suppressing defect generation, at least one selected from the group consisting of aminopyridine, pyridinecarboxamide, and nicotinamide is preferred. As the aminopyridine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, etc. can be mentioned.

[0067] Compound (III) is a compound having a 6-membered ring containing 2 nitrogen atoms in the ring. It is speculated that: the empty orbital of the nitrogen atom in the ring of compound (III) and the non-bonding electron pair of the oxygen atom of the hydroxyl group on the silicon material are coordinately bonded at 2 positions, whereby the surface of the silicon material is appropriately protected. It is speculated that: in a compound having a 5-membered ring (such as pyrazole), nitrogen atoms having empty orbitals and nitrogen atoms having non-bonding electron pairs are mixed and close to each other, so the coordination bonding property and hydrogen bonding property are weak. It is speculated that: even when the 6-membered ring contains 3 or more nitrogen atoms in the ring, nitrogen atoms having empty orbitals and nitrogen atoms having non-bonding electron pairs are mixed and close to each other, so the coordination bonding property and hydrogen bonding property are weak.

[0068] As the 6-membered ring, an aromatic ring, a non-aromatic ring, etc. can be mentioned. From the viewpoint of further suppressing defect generation, an aromatic ring is preferred. The aromatic ring is, for example, a heteroaromatic ring. As the 6-membered ring containing 2 nitrogen atoms in the ring, a pyrazine ring is preferred.

[0069] In compound (III), from the viewpoint of further suppressing defect generation, the number of functional groups containing a nitrogen atom is preferably 1 or less. As the functional group containing a nitrogen atom, an amino group, an amide group, a sulfonamide group, etc. can be mentioned. The 6-membered ring containing 2 nitrogen atoms in the ring is not included in the functional group containing a nitrogen atom.

[0070] As compound (III), pyrazine, pyrazinecarboxamide, 2,5-dimethylpyrazine, 2,3-dimethylpyrazine, 2,3-diethylpyrazine, 2,3,5,6-tetramethylpyrazine, etc. can be mentioned. From the viewpoint of further suppressing defect generation, at least one selected from the group consisting of pyrazine, pyrazinecarboxamide, 2,5-dimethylpyrazine, 2,3-dimethylpyrazine, and 2,3,5,6-tetramethylpyrazine is preferred.

[0071] Compound (IV) is a compound having a benzene ring and a ring containing a nitrogen atom in the ring. It is speculated that due to the electron-withdrawing property of the benzene ring in compound (IV), the coordination bonding property between the empty orbital of the nitrogen atom in the ring on compound (IV) and the non-bonding electron pair of the oxygen atom of the hydroxyl group on the silicon material is enhanced, whereby the surface of the silicon material is appropriately protected.

[0072] As a ring containing a nitrogen atom in the ring, a 3-membered ring, a 4-membered ring, a 5-membered ring, a 6-membered ring, etc. can be cited. From the viewpoint of further suppressing defect generation, a 5-membered ring is preferred. The ring containing a nitrogen atom in the ring can be an aromatic ring or a non-aromatic ring. As the ring containing a nitrogen atom in the ring, a pyridine ring, an azole ring, a triazole ring, an imidazole ring, a pyrazole ring, an oxazole ring, a thiazole ring, a pyrazine ring, a thiazine ring, an azepine ring, a pyrrolidine ring, a piperidine ring, an imidazoline ring, a morpholine ring, a pyrazoline ring, a pyrazolone ring, etc. can be cited. From the viewpoint of further suppressing defect generation, at least one selected from the group consisting of a triazole ring and a pyrazolone ring is preferred. From the viewpoint of further suppressing defect generation, the number of nitrogen atoms in the ring containing a nitrogen atom in the ring is preferably 2 or more. From the viewpoint of further suppressing defect generation, the number of nitrogen atoms in the ring containing a nitrogen atom in the ring is preferably 4 or less, more preferably 3 or less. The benzene ring and the ring containing a nitrogen atom in the ring may share carbon atoms constituting the ring or may not share carbon atoms. (Azepine) ring, a pyrrolidine ring, a piperidine ring, an imidazoline ring, a morpholine ring, a pyrazoline ring, a pyrazolone ring, etc. From the viewpoint of further suppressing defect generation, at least one selected from the group consisting of a triazole ring and a pyrazolone ring is preferred. From the viewpoint of further suppressing defect generation, the number of nitrogen atoms in the ring containing a nitrogen atom in the ring is preferably 2 or more. From the viewpoint of further suppressing defect generation, the number of nitrogen atoms in the ring containing a nitrogen atom in the ring is preferably 4 or less, more preferably 3 or less. The benzene ring and the ring containing a nitrogen atom in the ring may share carbon atoms constituting the ring or may not share carbon atoms.

[0073] From the viewpoint of further suppressing defect generation, compound (IV) is preferably at least one selected from the group consisting of benzotriazole and 1-phenyl-3-pyrazolidinone.

[0074] Compound (V) is a compound having a benzene ring to which two or more functional groups containing nitrogen atoms are bonded. It is speculated that the functional group containing a nitrogen atom of compound (V) forms a hydrogen bond with the hydroxyl group of the silicon material, and at the same time, the hydrogen bond is enhanced due to the electron-withdrawing property of the benzene ring on compound (V), whereby the surface of the silicon material is appropriately protected. It is speculated that when the functional group containing a nitrogen atom is one, the hydrogen bond is not sufficiently enhanced due to the electron-withdrawing property of the benzene ring.

[0075] Two or more functional groups containing nitrogen atoms are directly bonded to the benzene ring as substituents. As the functional group containing a nitrogen atom, from the viewpoint of further suppressing defect generation, at least one selected from the group consisting of an amino group, an amide group, and a sulfonamide group is preferred. The number of functional groups containing nitrogen atoms, from the viewpoint of further suppressing defect generation, is preferably 2 to 4, more preferably 2 to 3, and still more preferably 2. Regarding the arrangement of the functional groups containing nitrogen atoms, from the viewpoint of further suppressing defect generation, it is preferred that, relative to one functional group, the other functional groups are located at the para position of the benzene ring.

[0076] As compound (V), from the viewpoint of further suppressing defect generation, at least one selected from the group consisting of sulfanilamide and p-aminobenzamide is preferred. Compound (V) may include a compound not having a sulfonamide group. Compound (V) may not include a compound having a sulfonamide group.

[0077] Based on the view of further suppressing the generation of defects, the nitrogen-containing compound preferably contains at least one selected from the group consisting of compound (II), compound (III), and compound (IV), more preferably contains at least one selected from the group consisting of compound (II) and compound (III), and further preferably contains at least one selected from the group consisting of nicotinamide, aminopyridine, and pyrazinamide. Based on the view of further suppressing the generation of defects, the nitrogen-containing compound preferably contains compound (II), contains compound (III), or contains compound (IV), more preferably contains compound (II) or contains compound (III), and further preferably contains nicotinamide, contains aminopyridine, or contains pyrazinamide.

[0078] Based on the total mass of the polishing liquid, the content of the nitrogen-containing compound is preferably in the following range. Based on the view of easily obtaining a sufficient defect suppression effect, the content of the nitrogen-containing compound is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, further preferably 0.01% by mass or more, particularly preferably 0.03% by mass or more, extremely preferably 0.05% by mass or more, very preferably 0.07% by mass or more, and still more preferably 0.1% by mass or more. Based on the view of easily ensuring a sufficient polishing rate of the insulating material, the content of the nitrogen-containing compound is preferably 10% by mass or less, more preferably 5% by mass or less, further preferably 3% by mass or less, particularly preferably 1% by mass or less, extremely preferably 0.5% by mass or less, and very preferably 0.3% by mass or less. Based on these views, the content of the nitrogen-containing compound is preferably 0.001 to 10% by mass, more preferably 0.005 to 10% by mass, further preferably 0.01 to 10% by mass, particularly preferably 0.03 to 5% by mass, extremely preferably 0.05 to 3% by mass, very preferably 0.07 to 1% by mass, still more preferably 0.07 to 0.5% by mass, and further preferably 0.1 to 0.3% by mass. Based on the view of easily obtaining a particularly sufficient defect suppression effect, the content of the nitrogen-containing compound may be 0.5% by mass or more and may be 1% by mass or more. Based on the view of easily ensuring a particularly sufficient polishing rate of the insulating material, the content of the nitrogen-containing compound may be 0.2% by mass or less, may be 0.1% by mass or less, may be less than 0.1% by mass, may be 0.05% by mass or less, or may be 0.01% by mass or less.

[0079] [Polymer compound (A)]

[0080] The polishing liquid according to this embodiment may contain at least one polymer compound (A) (excluding the compound equivalent to the nitrogen-containing compound) selected from the group consisting of a carboxyl group and a carboxylate group. By using the polymer compound (A), dishing can be suppressed.

[0081] The high molecular compound (A) can be used alone or in combination of two or more. The high molecular compound (A) preferably contains a polymer or its salt obtained by polymerizing a monomer containing at least one selected from the group consisting of acrylic acid and methacrylic acid (hereinafter, these are collectively referred to as “(meth)acrylic polymers”). The monomer may contain other monomers copolymerizable with acrylic acid or methacrylic acid (excluding acrylic acid and methacrylic acid).

[0082] As the high molecular compound (A), at least one selected from the group consisting of homopolymers of acrylic acid (polyacrylic acid), homopolymers of methacrylic acid (polymethacrylic acid), copolymers of acrylic acid and methacrylic acid, copolymers of acrylic acid or methacrylic acid and other monomers, copolymers of acrylic acid and methacrylic acid and other monomers, and their salts can be used. Among them, as the (meth)acrylic polymer, from the viewpoint of good adsorption to the stopper material, at least one selected from the group consisting of homopolymers of acrylic acid (polyacrylic acid) and its salts is preferred. As the salt of the polymer (polymer having a carboxylate group), ammonium salts etc. can be mentioned. As the ammonium salt, ammonium polyacrylate etc. can be mentioned. The (meth)acrylic polymer can be used alone or in combination of two or more.

[0083] As other monomers (other monomers copolymerizable with acrylic acid or methacrylic acid), for example, unsaturated carboxylic acids such as crotonic acid, pentenoic acid, hexenoic acid, heptenoic acid, octenoic acid, nonenoic acid, decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, heptadecenoic acid, etc.; vinyl compounds such as ethylene, propylene, styrene, etc. can be mentioned.

[0084] The weight-average molecular weight of the high molecular compound (A) is preferably in the following range. From the viewpoint of having a tendency to easily obtain a good polishing rate when polishing an insulating material (such as silica), the weight-average molecular weight of the high molecular compound (A) is preferably 100 or more, more preferably 1000 or more, further preferably 2000 or more, particularly preferably 2500 or more. From the viewpoint of having a tendency that the storage stability of the polishing liquid is difficult to decrease, the weight-average molecular weight of the high molecular compound (A) is preferably 150000 or less, more preferably 80000 or less, further preferably 10000 or less, particularly preferably 7000 or less, and extremely preferably 5000 or less. From these viewpoints, the weight-average molecular weight of the high molecular compound (A) is preferably 100 to 150000, more preferably 1000 to 80000, further preferably 1000 to 10000, particularly preferably 2000 to 7000, and extremely preferably 2500 to 5000.

[0085] The weight-average molecular weight can be measured by reading the value obtained as “Mw” by the following method.

[0086] Measurement Method

[0087] Machine (detector) used: Refractive index detector "L-3300" for liquid chromatography, manufactured by Hitachi, Ltd.

[0088] Pump: "L-7100" for liquid chromatograph, manufactured by Hitachi, Ltd.

[0089] Degassing device: None

[0090] Data processing: GPC integrator "D-2520", manufactured by Hitachi, Ltd.

[0091] Column: "Shodex Asahipak GF-710HQ", manufactured by Showa Denko K.K., inner diameter 7.6 mm × 300 mm

[0092] Eluent: 50 mM-Na 2 HPO 4 Aqueous solution / acetonitrile = 90 / 10 (v / v)

[0093] Measurement temperature: 25 °C

[0094] Flow rate: 0.6 mL / min (L represents liter, the same hereinafter)

[0095] Measurement time: 30 minutes

[0096] Sample: A sample prepared by adjusting the concentration with a solution having the same composition as the eluent so that the resin component concentration becomes 2% by mass and filtering with a 0.45 μm polytetrafluoroethylene filter

[0097] Injection volume: 0.4 μL

[0098] Standard substance: Narrow molecular weight sodium polyacrylate, manufactured by Polymer Laboratories

[0099] Based on the total mass of the abrasive slurry, the content of the high molecular compound (A) is preferably in the following range. From the viewpoint of easily reducing the amount of dish-shaped defects and easily ensuring sufficient surface flatness, the content of the high molecular compound (A) is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and further preferably 0.1% by mass or more. The content of the high molecular compound (A), from the viewpoint of easily suppressing the reduction in the storage stability of the abrasive grains and easily causing agglomeration of the abrasive grains, is preferably 2% by mass or less, more preferably 1% by mass or less, further preferably 0.5% by mass or less, and particularly preferably 0.3% by mass or less. Based on these viewpoints, the content of the high molecular compound (A) is preferably 0.001 to 2% by mass, more preferably 0.01 to 1% by mass, further preferably 0.1 to 0.5% by mass, and particularly preferably 0.1 to 0.3% by mass.

[0100] [Polymer compound (B): Nonionic polymer compound]

[0101] The polishing liquid according to this embodiment may contain a nonionic polymer compound (B) (excluding compounds equivalent to the nitrogen-containing compound or polymer compound (A)). The polymer compound (B) can act as a polishing inhibitor for the stop portion material that inhibits the polishing of the stop portion material. By using the polymer compound (B), an excellent polishing rate ratio of the insulating material to the stop portion material can be obtained.

[0102] Examples of the polymer compound (B) include polyalkylene glycol; polyoxyalkylene derivative; polyglycerol; vinyl alcohol polymer (excluding compounds equivalent to compounds having a polyoxyalkylene chain); acrylamide, methacrylamide or their α-substituted N-monosubstituted or N,N-disubstituted products); polyvinylpyrrolidone, and copolymers having a structural unit derived from vinylpyrrolidone; other water-soluble nonionic compounds, etc. The polymer compound (B) can be used alone or in combination of two or more.

[0103] Examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, etc.

[0104] Examples of the polyoxyalkylene derivative include compounds obtained by introducing a functional group and / or a substituent into polyalkylene glycol, compounds obtained by adding polyalkylene oxide to an organic compound, etc. Examples of the functional group and the substituent include alkyl ether, alkylphenyl ether, phenyl ether, styrylated phenyl ether, alkylamine, fatty acid ester, ethylene glycol ester, polyglycerol ether, diglycerol ether, sugar ether, sugar ester, etc.

[0105] Examples of polyalkylene oxide derivatives include polyoxyethylene styrenated phenyl ethers (e.g., NOIGEN (registered trademark) EA series manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.); polyoxyethylene alkyl ethers (e.g., EMULGEN (registered trademark) series manufactured by Kao Corporation); polyoxyethylene alkyl phenyl ethers (e.g., EMARUJITTO (registered trademark) series manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.); polyoxyethylene sorbitan fatty acid esters (e.g., SORGEN (registered trademark) TW series manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.); polyoxyethylene fatty acid esters (e.g., EMANON (registered trademark) series manufactured by Kao Corporation); polyoxyethylene alkylamines (e.g., AMIRADJIN (registered trademark) D manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.); polyoxypropylene sorbitol (e.g., UNIOR (registered trademark) HS-1600D manufactured by NOF Corporation); polyoxyethylene diglycerol ethers (e.g., SC-E series manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), polyoxypropylene diglycerol ethers (e.g., SY-DP series manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) and other polyalkylene oxide diglycerol ethers; polyoxyethylene polyglycerol ethers, polyoxypropylene polyglycerol ethers, polyoxyethylene polyoxypropylene ethylene glycol ethers (e.g., EPAN manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) and other polyalkylene oxide polyglycerol ethers; compounds to which polyalkenyl oxide is added (e.g., SURFYNOL (registered trademark) 465 manufactured by Air Products Japan, Ltd.; TMP series manufactured by Nippon Emulsion Co., Ltd.).

[0106] The vinyl alcohol has a tendency not to exist as a stable compound in the monomer. Therefore, a vinyl alcohol polymer is obtained by saponifying (hydrolyzing) a polycarboxylic acid vinyl ester obtained by polymerizing a carboxylic acid vinyl ester monomer such as vinyl acetate monomer. Thus, for example, a vinyl alcohol polymer obtained by using vinyl acetate monomer as a raw material has -OCOCH as a functional group in the molecule 3 and hydrolyzed -OH, and the ratio of -OH formed is defined as the degree of saponification. That is, a vinyl alcohol polymer with a saponification degree not of 100% substantially has a structure similar to that of a copolymer of vinyl acetate and vinyl alcohol. In addition, a vinyl alcohol polymer may be a polymer obtained by copolymerizing a carboxylic acid vinyl ester monomer such as vinyl acetate monomer and other vinyl-containing monomers (e.g., ethylene, propylene, styrene, vinyl chloride) and then saponifying all or part of the portion derived from the carboxylic acid vinyl ester monomer. Specific examples of such vinyl alcohol polymers include PVA-403 manufactured by Kuraray Co., Ltd. and JC-25 manufactured by Nippon VAM & Poval Co., Ltd. In this specification, they are collectively defined as "vinyl alcohol polymers".

[0107] The vinyl alcohol polymer can be a derivative of a homopolymer of vinyl alcohol (i.e., a polymer with a saponification degree of 100%), a copolymer of vinyl alcohol monomer and other vinyl-containing monomers (such as ethylene, propylene, styrene, vinyl chloride, vinyl acetate), etc. As such derivatives, compounds in which at least a part of the hydroxyl groups are substituted by amino groups, carboxyl groups, ester groups, etc., compounds in which at least a part of the hydroxyl groups are modified, etc. can be cited. Specifically, reactive polyvinyl alcohol (e.g., GOSEFIMER (registered trademark) Z manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), cationized polyvinyl alcohol (e.g., GOSEFIMER (registered trademark) K manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), anionic polyvinyl alcohol (e.g., GOHSERAN (registered trademark) L, GOHSERAN (registered trademark) T manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), polyvinyl alcohol modified with hydrophilic groups (e.g., ECOMATY (registered trademark) manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), etc. can be cited.

[0108] Examples of the N-monosubstituted product include N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-isopropylacrylamide, N-butylacrylamide, N-isobutylacrylamide, N-tert-butylacrylamide, N-heptylacrylamide, N-octylacrylamide, N-tert-octylacrylamide, N-dodecylacrylamide, N-octadecylacrylamide, N-hydroxymethylacrylamide, N-acetylacrylamide, N-diacetoneacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, N-isopropylmethacrylamide, N-butylmethacrylamide, N-isobutylmethacrylamide, N-tert-butylmethacrylamide, N-heptylmethacrylamide, N-octylmethacrylamide, N-tert-octylmethacrylamide, N-dodecylmethacrylamide, N-octadecylmethacrylamide, N-hydroxymethylmethacrylamide, N-acetylmethacrylamide, etc.

[0109] Examples of the N,N-disubstituted compound include N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-dipropylacrylamide, N,N-diisopropylacrylamide, N,N-dibutylacrylamide, N,N-diisobutylacrylamide, N,N-di-tert-butylacrylamide, N,N-diheptylacrylamide, N,N-dioctylacrylamide, N,N-di-tert-octylacrylamide, N,N-didodecylacrylamide, N,N-distearylacrylamide, N,N-dihydroxymethylacrylamide, N,N-diacetylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylmethacrylamide, N,N-dipropylmethacrylamide, N,N-diisopropylmethacrylamide, N,N-dibutylmethacrylamide, N,N-diisobutylmethacrylamide, N,N-di-tert-butylmethacrylamide, N,N-diheptylmethacrylamide, N,N-dioctylmethacrylamide, N,N-di-tert-octylmethacrylamide, N,N-didodecylmethacrylamide, N,N-distearylmethacrylamide, N,N-dihydroxymethylmethacrylamide, N,N-diacetylmethacrylamide, acryloylpiperidine, acryloylmorpholine, acryloylthiomorpholine, acryloylpyrrolidine, and the like.

[0110] Examples of other water-soluble nonionic compounds include polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol distearate, polyethylene glycol monooleate, polyoxyethylene alkylamine, polyoxyethylene hydrogenated castor oil, alkyl alkanolamide, and the like.

[0111] The weight average molecular weight of the high molecular compound (B) is preferably in the following range. From the viewpoint of the tendency to easily obtain good flatness when polishing an insulating material (such as silica), the weight average molecular weight of the high molecular compound (B) is preferably 100 or more, more preferably 300 or more, and still more preferably 500 or more. From the viewpoint of the tendency to easily obtain good polishing rate when polishing an insulating material (such as silica), the weight average molecular weight of the high molecular compound (B) is preferably 10,000 or less, more preferably 7,000 or less, and still more preferably 5,000 or less. From these viewpoints, the weight average molecular weight of the high molecular compound (B) is preferably from 100 to 10,000, more preferably from 300 to 7,000, and still more preferably from 500 to 5,000. The weight average molecular weight of the high molecular compound (B) can be measured in the same manner as the weight average molecular weight of the high molecular compound (A).

[0112] The content of the high molecular compound (B) is preferably in the following range based on the total mass of the polishing liquid. From the viewpoint of easily ensuring sufficiently the inhibitory effect on the polishing of the stopper material, the content of the high molecular compound (B) is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, still more preferably 0.015% by mass or more, particularly preferably 0.02% by mass or more, extremely preferably 0.03% by mass or more, and very preferably 0.04% by mass or more. From the viewpoint of easily ensuring a sufficient polishing rate of the insulating material, the content of the high molecular compound (B) is preferably 2% by mass or less, more preferably 1.5% by mass or less, still more preferably 1% by mass or less, particularly preferably 0.5% by mass or less, extremely preferably 0.1% by mass or less, and very preferably 0.05% by mass or less. From these viewpoints, the content of the high molecular compound (B) is preferably 0.005 to 2% by mass, more preferably 0.01 to 1.5% by mass, still more preferably 0.015 to 1% by mass, particularly preferably 0.02 to 0.5% by mass, extremely preferably 0.03 to 0.1% by mass, and very preferably 0.04 to 0.05% by mass.

[0113] [pH adjuster]

[0114] The polishing liquid according to the present embodiment may contain a pH adjuster (excluding compounds equivalent to the nitrogen-containing compound, the high molecular compound (A), or the high molecular compound (B)). The pH can be adjusted to a desired value by the pH adjuster. The pH adjuster is not particularly limited, and examples thereof include basic compounds such as ammonia, sodium hydroxide, potassium hydroxide, and calcium hydroxide; acid components such as organic acid components and inorganic acid components. Examples of the inorganic acid component include nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, and boric acid. The pH adjuster may be used alone or in combination of two or more. When the polishing liquid is used for semiconductor polishing, ammonia or an acid component is preferably used.

[0115] As the pH adjuster, from the viewpoint of easily obtaining a good polishing rate of the insulating material, a basic compound is preferred, and ammonia is more preferred. Since the basic compound may cause recessed defects, the content of the basic compound is preferably as small as possible. From the viewpoint of further suppressing the generation of defects, the content of the basic compound is preferably 0.04 mol / kg or less, more preferably 0.035 mol / kg or less, still more preferably 0.03 mol / kg or less, based on the total amount of the polishing liquid. The content of the basic compound based on the total amount of the polishing liquid may be 0.01 mol / kg or more, or may be 0.015 mol / kg or more.

[0116] [Other additives]

[0117] The abrasive liquid according to this embodiment may contain additives different from the nitrogen-containing compound, polymer compound (A), polymer compound (B), pH adjuster, and dispersant. Examples of such additives include water-soluble polymer compounds. When the abrasive liquid is stored separately as a slurry and an additive liquid, these other additives are preferably included in the additive liquid. Examples of the water-soluble polymer compound include polysaccharides such as alginic acid, pectic acid, carboxymethyl cellulose, agar, curdlan, and pullulan. These additives may be used alone or in combination of two or more. The content is preferably 0.01 to 5% by mass based on the total mass of the abrasive liquid.

[0118] (Water)

[0119] There is no particular limitation on the water, and deionized water, ion-exchanged water, ultrapure water, etc. are preferred. The content of water may be the balance of the contents of the respective components, and there is no particular limitation as long as it is included in the abrasive liquid. In addition, the abrasive liquid may further contain a solvent other than water, such as a polar solvent such as ethanol or acetone, as needed.

[0120] (pH)

[0121] From the viewpoints of easily obtaining an excellent polishing rate of the insulating material and easily obtaining sufficient storage stability of the abrasive grains and easily suppressing the occurrence of aggregation of the abrasive grains, etc., the pH of the abrasive liquid according to this embodiment is preferably 3.0 or more, more preferably 3.5 or more, further preferably more than 3.5, particularly preferably 4.0 or more, extremely preferably more than 4.0, very preferably 4.5 or more, further preferably 5.0 or more, further preferably 5.5 or more, particularly preferably 6.0 or more, extremely preferably more than 6.0. From the viewpoints of easily suppressing the occurrence of defects (such as dimple defects) and easily ensuring the surface flatness after polishing (easily suppressing dish-shaped defects, etc.), the pH of the abrasive liquid according to this embodiment is preferably 8.0 or less, more preferably less than 8.0, further preferably 7.5 or less, particularly preferably 7.0 or less, extremely preferably 6.5 or less. From these viewpoints, 3.0 to 8.0 is preferred, more preferably 3.5 or more and less than 8.0, further preferably more than 3.5 and 7.5 or less, particularly preferably 4.0 to 7.5, extremely preferably more than 4.0 and 7.5 or less, very preferably 4.5 to 7.0, still more preferably 5.0 to 6.5, further preferably 5.5 to 6.5, particularly preferably 6.0 to 6.5, extremely preferably more than 6.0 and 6.5 or less. From the viewpoint of particularly easily suppressing the occurrence of defects (such as dimple defects), the pH of the abrasive liquid according to this embodiment may be 6.0 or less. From the viewpoint of easily obtaining a particularly excellent polishing rate of the insulating material, the pH of the abrasive liquid according to this embodiment may be 6.5 or more, may be 7.0 or more, may exceed 7.0, may be 7.5 or more. The pH of the abrasive liquid is the pH of the abrasive liquid at 25°C.

[0122] The pH of the polishing liquid can be measured using a pH meter (for example, trade name: Model PH81, manufactured by Yokogawa Electric Corporation). For example, after performing two-point calibration using standard buffer solutions (phthalate pH buffer solution, pH: 4.01 (25°C), and neutral phosphate pH buffer solution, pH: 6.86 (25°C)), the electrode is placed in the polishing liquid, and after more than 2 minutes at 25°C, the value after stabilization is measured.

[0123] <Manufacturing method of polishing liquid>

[0124] The manufacturing method of the polishing liquid according to the present embodiment at least includes a polishing liquid manufacturing step of obtaining a polishing liquid by mixing abrasive grains, the nitrogen-containing compound, and water. In the polishing liquid manufacturing step, the respective components may be mixed simultaneously, or the respective components may be mixed in sequence. The manufacturing method of the polishing liquid according to the present embodiment may include a step of obtaining abrasive grains (for example, cerium-containing abrasive grains) and a step of obtaining additives (for example, polymer compound (A) and / or polymer compound (B)) before the polishing liquid manufacturing step.

[0125] The manufacturing method of the polishing liquid according to the present embodiment preferably includes a dispersion step of dispersing abrasive grains in water. The dispersion step is, for example, a step of mixing abrasive grains and a dispersant. At this time, the dispersant is preferably added in the step of obtaining a slurry. That is, the slurry preferably contains a dispersant. In the dispersion step, for example, abrasive grains, a dispersant, and water are mixed to disperse the abrasive grains in water to obtain a slurry.

[0126] <Polishing liquid kit>

[0127] The polishing liquid according to the present embodiment can be stored by dividing the constituent components of the polishing liquid into a slurry (first liquid) and an additive liquid (second liquid) so that when the slurry (first liquid) and the additive liquid (second liquid) are mixed, the polishing liquid is formed. The slurry contains, for example, at least abrasive grains and water. The additive liquid contains, for example, at least an additive (for example, the nitrogen-containing compound) and water. As long as the pH adjuster does not change the polarity of the potential of the abrasive grains contained in the slurry, it may be contained in the slurry. The constituent components of the polishing liquid can be stored by dividing them into two liquids, namely, a slurry and an additive liquid, or can be stored in three or more liquids.

[0128] In the polishing liquid kit, the slurry and the additive liquid are mixed immediately before or during polishing to prepare the polishing liquid. The multi-liquid type polishing liquid kit can be stored as a storage liquid for the slurry for reducing the water content and a storage liquid for the additive liquid, and diluted with water immediately before or during polishing.

[0129] <Polishing method>

[0130] The polishing method according to this embodiment includes a polishing step of polishing a surface to be polished using the polishing liquid according to this embodiment or a polishing liquid obtained by mixing the slurry and the additive liquid in the polishing liquid kit according to this embodiment. The surface to be polished may contain, for example, a silicon material. The surface to be polished may contain at least one selected from the group consisting of polysilicon, amorphous silicon, and single crystal silicon, or may contain amorphous silicon.

[0131] The polishing method according to this embodiment is, for example, a polishing method for a substrate having a surface to be polished containing a silicon material. The polishing step may be a step of selectively (preferably) polishing an insulating material with respect to the silicon material (stop portion material). The polishing step may also be a step of selectively (preferably) polishing silicon oxide with respect to the silicon material (polysilicon, amorphous silicon, etc.). The polishing step may also be a step of using the silicon material (polysilicon, amorphous silicon, etc.) as a stop portion material and polishing silicon oxide. Examples of the stop portion material include single crystal silicon, polysilicon, and amorphous silicon.

[0132] The polishing method according to this embodiment may be a polishing method for a substrate having a first component containing a silicon material and a second component containing an insulating material and disposed on the first component. The polishing step may include a step of using the polishing liquid according to this embodiment or a polishing liquid obtained by mixing the slurry and the additive liquid in the polishing liquid kit according to this embodiment to polish the second component until the first component is exposed. The polishing step may include the following steps: after the first component is exposed, using the polishing liquid according to this embodiment or a polishing liquid obtained by mixing the slurry and the additive liquid in the polishing liquid kit according to this embodiment to polish the first component and the second component.

[0133] Examples of the insulating material include inorganic insulating materials and organic insulating materials. Examples of the inorganic insulating material include silicon-based insulating materials. Examples of the silicon-based insulating material include silicon dioxide-based materials such as silicon oxide, silicon nitride, fluorosilicate glass, organosilicate glass, and hydrogenated silsesquioxane; silicon carbide, silicon nitride; carbon-containing silicon oxide, etc. Examples of the organic insulating material include, for example, fully aromatic low dielectric constant insulating materials. Elements such as phosphorus and boron may be doped in the insulating material (such as silicon oxide).

[0134] The polishing process may be a process of exposing the stop portion by removing at least a part of an insulating member (a member containing an insulating material) using the polishing liquid according to the present embodiment. For example, the polishing method according to the present embodiment may be a polishing method for polishing a substrate having an insulating member on its surface. The polishing method according to the present embodiment includes, for example, a substrate preparation process, a substrate arrangement process, and a polishing process. In the substrate preparation process, a substrate having, for example, a stop portion and an insulating member disposed on the stop portion is prepared. In the substrate arrangement process, the substrate is arranged, for example, such that the insulating member faces the polishing pad. In the polishing process, at least a part of the insulating member is removed. In the polishing process, for example, in a state where the insulating member of the substrate having the insulating member is pressed against the polishing pad of the polishing table, the polishing liquid is supplied between the polishing pad and the insulating member, the substrate and the polishing table are relatively moved, and at least a part of the insulating member is polished and removed. The shape of the insulating member is not particularly limited, and is, for example, a film shape (insulating film). The shape of the stop portion is not particularly limited, and is, for example, a film shape (stop portion film: for example, a polysilicon film or an amorphous silicon film).

[0135] As the substrate, for example, a substrate having an insulating member formed thereon in a semiconductor element manufacturing process (a semiconductor substrate in a stage of forming circuit elements and wiring patterns, a semiconductor substrate in a stage of forming circuit elements, etc.) can be cited.

[0136] By polishing the insulating material formed on the semiconductor substrate using the polishing liquid according to the present embodiment, unevenness on the surface of the insulating material can be eliminated, and a smooth surface can be obtained on the entire surface of the substrate. The polishing method according to the present embodiment can be used, for example, for planarization processes such as interlayer insulating films and BPSG films, STI formation processes, and the like.

[0137] Figure 2 It is a schematic cross-sectional view showing an example of the polishing method. First, as Figure 2 (A) shows, a substrate 100 is prepared, which includes a wafer 1 having unevenness formed on its surface, the unevenness being composed of concave portions (groove portions) and convex portions (active portions), a stop portion (for example, a polysilicon film or an amorphous silicon film) 2 formed on the convex portions of the wafer 1, and an insulating member (for example, a silicon oxide film) 3 formed on the wafer 1 and the stop portion 2 so as to fill the unevenness on the surface of the wafer 1. The insulating member 3 can be formed, for example, by deposition such as the plasma TEOS method.

[0138] Then, using the polishing liquid according to the present embodiment, the insulating member 3 is polished and removed until the stop portion 2 on the convex portions of the wafer 1 is exposed. Thus, as Figure 2 (B) shows, a substrate 200 is obtained. In the substrate 200 after polishing, preferably, the value obtained by subtracting the thickness 5 of the insulating member 3 in the groove portion from the depth 4 of the groove portion, that is, the dishing defect amount 6 is small. In addition, it is preferable that the number of recessed defects of the stop portion 2 in the substrate 200 is small.

[0139] As a polishing device, for example, a polishing device manufactured by APPLIED MATERIALS (trade name: Mirra-3400, Reflexion LK) and a polishing device manufactured by Ebara Corporation (trade name: F-REX300) can be cited.

[0140] As a polishing pad, generally, non-woven fabric, foam, non-foam, etc. can be used. As the material of the polishing pad, resins such as polyurethane, acrylic resin, polyester, acrylic-ester copolymer, polytetrafluoroethylene, polypropylene, polyethylene, poly-4-methylpentene, cellulose, cellulose ester, polyamide (such as nylon (trade name) and aromatic polyamide), polyimide, polyimide amide, polysiloxane copolymer, ethylene oxide compound, phenolic resin, polystyrene, polycarbonate, epoxy resin, etc. can be used. In particular, from the viewpoint of obtaining more excellent polishing speed and flatness, foamed polyurethane and non-foamed polyurethane are preferred as the material of the polishing pad. Groove processing for retaining the polishing liquid can be performed on the polishing pad.

[0141] The polishing conditions are not limited, but the rotation speed of the polishing table is preferably 200 min -1 (rpm) or less so that the substrate does not fly out. From the viewpoint of sufficiently suppressing the generation of polishing scratches, the polishing pressure (processing load) applied to the substrate is preferably 100 kPa or less. During polishing, the polishing liquid is preferably continuously supplied to the polishing pad by a pump or the like. The supply amount is not limited, but it is preferred that the surface of the polishing pad is always covered with the polishing liquid.

[0142] After polishing, the substrate is preferably carefully washed in running water to remove the particles attached to the substrate. Dilute hydrofluoric acid or ammonia water can be used in addition to pure water for washing, and a brush can be used to improve the washing efficiency. In addition, it is preferred to remove the water droplets attached to the substrate after washing with a spin dryer or the like and then dry the substrate.

[0143] In the polishing method according to this embodiment, as the substrate to be polished, for example, a substrate having the following structure can be applied: discrete semiconductors such as diodes, transistors, compound semiconductors, thermistors, varistors, thyristors, etc.; memory elements such as DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), EPROM (Erasable Programmable Read-Only Memory), MASK ROM (Mask Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory, etc.; theoretical circuit elements such as microprocessors, DSPs, ASICs, etc.; integrated circuit elements such as compound semiconductors represented by MMIC (Monolithic Microwave Integrated Circuit); optoelectronic conversion devices such as hybrid integrated circuits (Hybrid IC), light-emitting diodes, charge-coupled devices, etc.

[0144] The polishing liquid according to this embodiment is not limited to the polishing of insulating components formed on a semiconductor substrate as described in the above embodiment, and can be applied to the polishing of inorganic insulating materials such as silicon oxide, glass, and silicon nitride formed on a wiring board having specified wirings; and the polishing of materials mainly containing Al, Cu, Ti, TiN, W, Ta, TaN, etc.

[0145] As the electronic components serving as the substrate to be polished in the polishing method according to this embodiment, many types can be cited. As the electronic components, not only semiconductor elements, optical stripping of photomasks, lenses, prisms, etc.; inorganic conductive films such as ITO; optical integrated circuits composed of glass and crystalline materials; optical switch devices; optical waveguides; fiber end faces; optical single crystals such as scintillators; solid laser single crystals; sapphire substrates for blue laser LEDs; semiconductor single crystals such as SiC, GaP, and GaAs; glass substrates for magnetic disks; magnetic heads, etc. can be cited. Among these electronic components, by polishing each layer with the polishing liquid according to this embodiment, high integration can be achieved, and at the same time, excellent characteristics can be exhibited.

[0146] <Defect suppression method>

[0147] The defect suppression method according to this embodiment is a defect suppression method for suppressing the generation of defects in the polishing of a polished surface including a stopper material. The defect suppression method according to this embodiment includes a polishing step of polishing the polished surface using the polishing liquid according to this embodiment or a polishing liquid obtained by mixing the slurry and the additive liquid in the polishing liquid set according to this embodiment. In the defect suppression method according to this embodiment, by using the nitrogen-containing compound that acts as a defect inhibitor, the generation of defects in the polishing of the polished surface including the stopper material can be suppressed, and in particular, the generation of defects based on chemical action can be suppressed. The defect suppression method according to this embodiment, for example, after the polishing step, further includes an observation step of observing the defects generated on the polished surface. The stopper material may contain at least one selected from the group consisting of polysilicon, amorphous silicon, and single crystal silicon, and may contain amorphous silicon.

[0148] Examples

[0149] Hereinafter, the present invention will be described by way of examples, but the present invention is not limited by these examples.

[0150] <Preparation of constituent components of CMP polishing liquid>

[0151] (Abrasive grains)

[0152] [Cerium oxide particles]

[0153] 40 kg of commercially available cerium carbonate hydrate was charged into an alumina container and calcined in air at 830 °C for 2 hours, whereby 20 kg of a yellowish-white powder was obtained. When the phase identification of this powder was carried out by X-ray diffraction method, it was confirmed to be cerium oxide. 20 kg of the obtained cerium oxide powder was dry pulverized with a jet mill to obtain a cerium oxide powder containing cerium oxide particles.

[0154] For the measurement of the average particle size (D50) of the abrasive grains, an abrasive grain and water were mixed so that the transmittance (H) at the time of measurement with He-Ne laser was 60 to 70%, and a measurement sample was obtained. When the D50 of the measurement sample was measured with a laser diffraction type particle size distribution meter (manufactured by Horiba, Ltd., trade name: LA-920, refractive index: 1.93, light source: He-Ne laser, absorption 0), the value of D50 was 150 nm.

[0155] [Silica particles]

[0156] As the silica particles, colloidal silica having an average particle size of 60 nm was used.

[0157] (Additive)

[0158] The following compounds were prepared as additives.

[0159] [Nitrogen-containing compound]

[0160] Compound (I): 3-Hydroxypyridine

[0161] Compound (II): 2-Aminopyridine, 3-Aminopyridine, 4-Aminopyridine, Picolinamide, Nicotinamide

[0162] Compound (III): Pyrazine, Pyrazinecarboxamide, 2,5-Dimethylpyrazine, 2,3-Diethylpyrazine, 2,3,5,6-Tetramethylpyrazine

[0163] Compound (IV): Benzotriazole, 1-Phenyl-3-pyrazolidinone

[0164] Compound (V): Sulfanilamide, p-Aminobenzamide

[0165] [Polymer compound (A)]

[0166] Polyacrylic acid having a weight average molecular weight of 2500 (in terms of sodium polyacrylate)

[0167] [Polymer compound (B)]

[0168] Polyoxyethylene polyoxypropylene glycol ether having a weight average molecular weight of 1200

[0169] [pH adjuster]

[0170] 25 mass% ammonia water

[0171] [Other additives]

[0172] As other additives, quinolinic acid, 1H-tetrazole, melamine, aminotetrazole, p-toluenesulfonamide, and pyrazole were prepared.

[0173] <Fabrication of CMP Slurry>

[0174] The components prepared as described above were dispersed or dissolved in water at the contents shown in Tables 1 to 4 to obtain a CMP slurry. In the tables, the content of the silica particles is the content of the solid components. The content of the pH regulator represents the content of ammonia without water. The pH of the CMP slurry was measured using a product named Model PH81 manufactured by Yokogawa Electric Corporation.

[0175] <Defect Evaluation>

[0176] As a test wafer for CMP evaluation of the number of defects, a wafer having an amorphous silicon film on a silicon substrate was prepared.

[0177] The test wafer for CMP evaluation was polished using a polishing apparatus (Mirra manufactured by APPLIED MATERIALS). The test wafer for CMP evaluation was set on the bracket of the adsorption plate for attaching the substrate. A polishing pad made of porous urethane resin (model IC1000 manufactured by Rohm and Haas Japan Co., Ltd.) was attached to the polishing table of the polishing apparatus. The surface with the amorphous silicon film was set downward, the bracket was placed on the polishing table, and the processing load was set to 3.6 psi (about 25 kPa).

[0178] While dropping the CMP slurry on the polishing table at a rate of 200 mL / min, the polishing table and the test wafer for CMP evaluation were rotated at 93 min -1 、87 min -1 respectively, and polished for 60 seconds. The polished wafer was carefully washed with pure water and dried.

[0179] The central part of the amorphous silicon film was observed at five positions under an optical microscope (DSX-510, product name, manufactured by Olympus Corporation) with an objective lens magnification of 20 times and a magnification ratio of 1.5 times, and the number of pit defects (pit defect number) was counted. The area of one field of view was 0.5 mm 2 . The average value of the five positions was taken as the number of defects and evaluated as follows: 0 to 9 defects is "A", 10 to 19 defects is "B", 20 to 99 defects is "C", and 100 or more defects is "D". Tables 1 to 4 show the results. It can be seen from Tables 1 to 4 that the generation of defects can be suppressed in the examples (evaluation A, B, or C).

[0180] <Polishing Rate Evaluation>

[0181] As a test wafer for CMP evaluation of the polishing rate, a wafer having a silicon oxide film formed by plasma CVD method on a silicon substrate was prepared. The CMP evaluation test wafer was polished using a polishing apparatus (manufactured by APPLIED MATERIALS, trade name: Mirra). Specifically, first, the CMP evaluation test wafer was set on a bracket for mounting the substrate on an adsorption plate. Then, on the polishing table of the polishing apparatus, a polishing cloth made of porous urethane resin (manufactured by Rohm and Haas Japan Co., Ltd., model: IC1000) was attached. With the surface of the silicon oxide film facing down, the bracket was placed on the polishing table, and the processing load was set to 3.6 psi (about 25 kPa). Then, while dropping the CMP polishing liquid on the polishing table at a rate of 200 mL / min, the polishing table and the evaluation test wafer were rotated at 93 min -1 , 87 min -1 respectively, and the CMP evaluation test wafer was polished for 60 seconds. After the polished wafer was carefully cleaned with pure water, it was dried.

[0182] Using an optical interference film thickness measuring apparatus (manufactured by SCREEN Holdings Co., Ltd., trade name: RE-3000), the film thickness of the silicon oxide film before and after polishing was measured. Then, by dividing the average value of the film thickness change amount by the polishing time, the polishing rate of the silicon oxide film (unit: nm / min) was calculated. The results are shown in Tables 1 to 4.

[0183]

Table 1

[0184]

[0185]

Table 2

[0186]

[0187]

Table 3

[0188]

[0189]

Table 4

[0190]

Claims

1. A polishing liquid, comprising: abrasive grains containing at least one selected from the group consisting of cerium oxide and silicon oxide, a nitrogen-containing compound, and water, wherein the nitrogen-containing compound contains at least one selected from sulfanilamide, p-aminobenzamide, 2,5-dimethylpyrazine, 2,3-dimethylpyrazine, 2,3-diethylpyrazine, 2,3,5,6-tetramethylpyrazine, and 1-phenyl-3-pyrazolidone, the content of the nitrogen-containing compound is 0.005 to 10% by mass; the pH is 5.0 or more.

2. The polishing liquid according to claim 1, wherein the nitrogen-containing compound contains at least one selected from the group consisting of 2,5-dimethylpyrazine, 2,3-dimethylpyrazine, 2,3-diethylpyrazine, and 2,3,5,6-tetramethylpyrazine.

3. The polishing liquid according to claim 1, wherein the nitrogen-containing compound contains 1-phenyl-3-pyrazolidone.

4. The polishing liquid according to claim 1, wherein the nitrogen-containing compound contains sulfanilamide.

5. The polishing liquid according to claim 1, wherein the nitrogen-containing compound contains p-aminobenzamide.

6. The polishing liquid according to any one of claims 1 to 5, wherein the content of the nitrogen-containing compound is 0.03 to 5% by mass.

7. The polishing liquid according to any one of claims 1 to 5, wherein the content of the nitrogen-containing compound is 0.07 to 0.5% by mass.

8. The polishing liquid according to any one of claims 1 to 5, further comprising a polymer compound A having at least one selected from the group consisting of a carboxyl group and a carboxylate group.

9. The polishing liquid according to claim 8, wherein the polymer compound A contains a polymer obtained by polymerizing a monomer containing at least one selected from the group consisting of acrylic acid and methacrylic acid or a salt thereof.

10. The polishing liquid according to claim 8, wherein the content of the polymer compound A is 0.001 to 2% by mass.

11. The polishing liquid according to any one of claims 1 to 5, further comprising a nonionic polymer compound B.

12. The polishing liquid according to claim 11, wherein the nonionic polymer compound B contains polyoxyalkylene polyglycerol ether.

13. The polishing liquid according to claim 11, wherein the content of the nonionic polymer compound B is 0.005 to 2% by mass.

14. The polishing liquid according to any one of claims 1 to 5, further comprising a basic compound.

15. The polishing liquid according to claim 14, wherein the basic compound contains ammonia.

16. The polishing liquid according to claim 14, wherein the content of the basic compound is 0.04 mol / kg or less.

17. The polishing liquid according to any one of claims 1 to 5, wherein the abrasive grains contain cerium oxide.

18. The polishing liquid according to any one of claims 1 to 5, wherein the abrasive grains contain silicon oxide.

19. The polishing liquid according to any one of claims 1 to 5, wherein the average particle size of the abrasive grains is 10 to 500 nm.

20. The polishing liquid according to any one of claims 1 to 5, wherein the content of the abrasive grains is 0.01 to 20% by mass.

21. The abrasive liquid according to any one of claims 1 to 5, wherein the content of the abrasive grains is 0.2 to 3% by mass.

22. The abrasive liquid according to any one of claims 1 to 5, having a pH of 5.0 to 8.

0.

23. The abrasive liquid according to any one of claims 1 to 5, having a pH of 5.0 to 7.

5.

24. The abrasive liquid according to any one of claims 1 to 5, having a pH of 5.0 to 6.

5.

25. An abrasive liquid kit, wherein the constituent components of the abrasive liquid according to any one of claims 1 to 24 are stored as a first liquid and a second liquid, the first liquid contains the abrasive grains and water, the second liquid contains the nitrogen-containing compound and water.

26. A polishing method, comprising the following steps: polishing a surface to be polished using the abrasive liquid according to any one of claims 1 to 24 or an abrasive liquid obtained by mixing the first liquid and the second liquid in the abrasive liquid kit according to claim 25.

27. The polishing method according to claim 26, wherein the surface to be polished contains at least one selected from the group consisting of polysilicon, amorphous silicon, and single crystal silicon.

28. A polishing method, comprising a step of polishing a surface to be polished using an abrasive liquid, wherein the material of the stop portion of the surface to be polished contains amorphous silicon; the abrasive liquid, comprises: abrasive grains containing at least one selected from the group consisting of cerium oxide and silicon oxide, a nitrogen-containing compound, and water, the nitrogen-containing compound contains at least one selected from nicotinamide, 2,3,5,6-tetramethylpyrazine, 2,3-diethylpyrazine, aminopyridine, 2,3-dimethylpyrazine, 2,5-dimethylpyrazine, benzotriazole, sulfanilamide, picolinamide, 1-phenyl-3-pyrazolidinone, pyrazine, pyrazinamide, hydroxypyridine, and p-aminobenzamide; the content of the nitrogen-containing compound is 0.005 to 10% by mass; the pH of the abrasive liquid is 5.0 or more.

29. The polishing method according to claim 28, wherein the nitrogen-containing compound contains 3-hydroxypyridine.

30. The polishing method according to claim 28, wherein the nitrogen-containing compound contains at least one selected from the group consisting of aminopyridine, picolinamide, and nicotinamide.

31. The polishing method according to claim 28, wherein the nitrogen-containing compound contains nicotinamide.

32. The polishing method according to claim 28, wherein the nitrogen-containing compound contains aminopyridine.

33. The polishing method according to claim 28, wherein the nitrogen-containing compound contains at least one selected from the group consisting of pyrazine, pyrazinamide, 2,5-dimethylpyrazine, 2,3-dimethylpyrazine, 2,3-diethylpyrazine, and 2,3,5,6-tetramethylpyrazine.

34. The polishing method according to claim 28, wherein the nitrogen-containing compound contains pyrazinamide.

35. The polishing method according to claim 28, wherein the nitrogen-containing compound contains at least one selected from the group consisting of benzotriazole and 1-phenyl-3-pyrazolidinone.

36. The grinding method according to claim 28, wherein the nitrogen-containing compound contains at least one selected from the group consisting of sulfanilamide and p-aminobenzamide.

37. The grinding method according to any one of claims 28 to 36, wherein the content of the nitrogen-containing compound is 0.03 to 5% by mass.

38. The grinding method according to any one of claims 28 to 36, wherein the content of the nitrogen-containing compound is 0.07 to 0.5% by mass.

39. The grinding method according to any one of claims 28 to 36, further comprising a polymer compound A having at least one selected from the group consisting of a carboxyl group and a carboxylate group.

40. The grinding method according to claim 39, wherein the polymer compound A contains a polymer obtained by polymerizing a monomer containing at least one selected from the group consisting of acrylic acid and methacrylic acid or a salt thereof.

41. The grinding method according to claim 39, wherein the content of the polymer compound A is 0.001 to 2% by mass.

42. The grinding method according to any one of claims 28 to 36, further comprising a nonionic polymer compound B.

43. The grinding method according to claim 42, wherein the nonionic polymer compound B contains a polyoxyalkylene derivative.

44. The grinding method according to claim 42, wherein the content of the nonionic polymer compound B is 0.005 to 2% by mass.

45. The grinding method according to any one of claims 28 to 36, further comprising a basic compound.

46. The grinding method according to claim 45, wherein the basic compound contains ammonia.

47. The grinding method according to claim 45, wherein the content of the basic compound is 0.04 mol / kg or less.

48. The grinding method according to any one of claims 28 to 36, wherein the abrasive grains contain cerium oxide.

49. The grinding method according to any one of claims 28 to 36, wherein the abrasive grains contain silicon oxide.

50. The grinding method according to any one of claims 28 to 36, wherein the average particle size of the abrasive grains is 10 to 500 nm.

51. The grinding method according to any one of claims 28 to 36, wherein the content of the abrasive grains is 0.01 to 20% by mass.

52. The grinding method according to any one of claims 28 to 36, wherein the content of the abrasive grains is 0.2 to 3% by mass.

53. The grinding method according to any one of claims 28 to 36, wherein the pH is 5.0 to 8.

0.

54. The grinding method according to any one of claims 28 to 36, wherein the pH is 5.0 to 7.

5.

55. The grinding method according to any one of claims 28 to 36, wherein the pH is 5.0 to 6.

5.

56. The grinding method according to any one of claims 28 to 36, wherein the grinding liquid is a grinding liquid obtained by mixing a first liquid and a second liquid in a grinding liquid kit; The grinding liquid kit stores the components of the grinding liquid by dividing them into a first liquid and a second liquid, The first liquid contains the abrasive grains and water, The second liquid contains the nitrogen-containing compound and water.

57. A defect suppression method is a defect suppression method for suppressing defects generated during polishing of a polished surface including a stop portion material, the stop portion material containing amorphous silicon, comprising the following step: polishing the polished surface using the polishing liquid according to any one of claims 1 to 24 or the polishing liquid obtained by mixing the first liquid and the second liquid in the polishing liquid concentrate according to claim 25.

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