CMP polishing liquid and polishing method

Abstract

This CMP polishing liquid is for polishing a polished member containing a carbon material and contains abrasive grains, iron ions, and an organic acid. This polishing method comprises a step in which a polished member containing a carbon material is polished using the aforementioned CMP polishing liquid. A method for producing a semiconductor device according to the present invention includes obtaining a semiconductor device using a polished member polished by the polishing method.

Description

CMP polishing liquid and polishing method

[0001] The present disclosure relates to a CMP polishing liquid, a polishing method, and the like.

[0002] In recent years, electronic devices have become smaller and more functionally advanced, and as a result, the demand for higher integration and performance of semiconductor integrated circuits (LSIs) has become increasingly stringent. One of the technologies for achieving higher integration and performance of semiconductor integrated circuits (LSIs) is chemical mechanical polishing (CMP). CMP polishes the surface of a substrate by pressing the substrate against a polishing pad while supplying a polishing liquid between the surface of the substrate and the polishing pad, thereby flattening and smoothing the surface of a semiconductor wafer. CMP is a particularly important technology for planarizing layers formed on a wafer.

[0003] In semiconductor integrated circuits (LSIs) aiming for higher integration and higher functionality, carbon materials (e.g., polyimide resins) with excellent properties such as electrical insulation, heat resistance, and mechanical strength are increasingly being used. Carbon materials are used as insulating layers between different metal layers and wiring, and because of their high hardness and chemical resistance, they are required to be efficiently removed by CMP. In response to this demand, Patent Document 1 describes a polishing composition containing at least one abrasive grain having a modified Mohs hardness of 13 or more, as a polishing liquid that can polish polyimide films in a short time, maintain high flatness, and suppress the occurrence of polishing scratches.

[0004] Special Publication No. 2010-135472

[0005] When polishing a carbon material, it is sometimes required to polish not only the carbon material but also a metal material at the same time, and therefore, the CMP polishing liquid used for polishing the carbon material is sometimes required to polish not only the carbon material but also the metal material at a high polishing rate.

[0006] Therefore, an object of one aspect of the present disclosure is to provide a CMP polishing liquid capable of polishing carbon materials and metal materials at an excellent polishing rate.Another object of the present disclosure is to provide a polishing method using such a CMP polishing liquid.

[0007] The present disclosure includes, for example, the following [1] to

[18] . [1] A CMP polishing liquid for polishing a workpiece containing a carbon material, the CMP polishing liquid containing abrasive grains, iron ions, and an organic acid. [2] The CMP polishing liquid according to [1], wherein the abrasive grains contain particles having a Mohs hardness of less than 8. [3] The CMP polishing liquid according to [1] or [2], wherein the abrasive grains contain silica particles. [4] The CMP polishing liquid according to any one of [1] to [3], wherein the iron ion content is 0.001 to 0.2 mass %. [5] The CMP polishing liquid according to any one of [1] to [4], wherein the mass ratio of the abrasive grain content to the iron ion content is 50 to 500. [6] The CMP polishing liquid according to any one of [1] to [5], further containing an oxidizing agent. [7] The CMP polishing liquid according to [6], wherein the oxidizing agent contains a peroxide. [8] The CMP polishing liquid according to any one of [1] to [7], further containing an organic acid component. [9] The CMP polishing liquid according to [8], wherein the organic acid component contains an amino acid component.

[10] The CMP polishing liquid according to [8] or [9], wherein the content of the organic acid component is 0.1 to 5 mass %.

[11] The CMP polishing liquid according to any one of [1] to

[10] , further containing an organic solvent.

[12] The CMP polishing liquid according to

[11] , wherein the organic solvent contains 3-methoxy-3-methyl-1-butanol.

[13] The CMP polishing liquid according to any one of [1] to

[12] , wherein the pH is 1.0 to 7.0.

[14] The CMP polishing liquid according to any one of [1] to

[13] , wherein the carbon material contains a polyimide resin.

[15] The CMP polishing liquid according to any one of [1] to

[14] , wherein the polished member further contains a metal material.

[16] The CMP polishing slurry according to

[15] , wherein the metal material comprises at least one selected from the group consisting of copper, a copper alloy, an oxide of copper, and an oxide of a copper alloy.

[17] A polishing method comprising a step of polishing a workpiece containing a carbon material using the CMP polishing slurry according to any one of [1] to

[16] .

[18] A method for producing a semiconductor device, wherein a semiconductor device is obtained using a workpiece polished by the polishing method according to

[17] .

[0008] According to one aspect of the present disclosure, there is provided a CMP polishing liquid capable of polishing carbon materials and metal materials at an excellent polishing rate. Also, according to another aspect of the present disclosure, there is provided a polishing method using such a CMP polishing liquid.

[0009] Hereinafter, embodiments of the present disclosure will be described.

[0010] In this specification, numerical ranges indicated using "to" indicate a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. A numerical range "A or greater" means a range exceeding A and A. A numerical range "A or less" means a range less than A and A. In numerical ranges described in stages in this specification, the upper or lower limit of a numerical range in a certain stage can be arbitrarily combined with the upper or lower limit of a numerical range in another stage. In numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. "A or B" may include either A or B, or may include both. Unless otherwise specified, the materials exemplified in this specification can be used alone or in combination of two or more. When multiple substances corresponding to each component are present in the composition, the content of each component in the composition refers to the total amount of the multiple substances present in the composition, unless otherwise specified. The term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes, as long as the intended effect of the process is achieved.

[0011] The CMP polishing liquid according to this embodiment (hereinafter simply referred to as the "polishing liquid") is a polishing liquid for polishing carbon materials (polishing liquid for carbon materials) and can be used to polish surfaces containing carbon materials. The carbon material is a carbon-containing material containing carbon atoms. Carbon materials can be materials in which carbon atoms account for at least one-third of the total atoms constituting the carbon material (i.e., a carbon content of at least 33 atomic % based on the total amount of atoms constituting the carbon material). Examples of carbon materials include resin materials such as polyimide resins, epoxy resins, acrylic resins (polymers having structural units derived from monomers containing (meth)acryloyl groups), polybenzoxazole resins, and phenolic resins; and amorphous carbon (diamond-like carbon (DLC)). The carbon material may include at least one selected from the group consisting of polyimide resins, epoxy resins, acrylic resins, polybenzoxazole resins, phenolic resins, and amorphous carbon. The carbon material can have carbon-carbon bonds. The carbon material can be a photosensitive resin or a non-photosensitive resin (a resin that does not have photosensitivity).

[0012] Polyimide resins have excellent electrical insulation properties and can be used as insulating layers between different metal layers or wirings. Examples of methods for forming polyimide resin films include forming a thin film from a polyimide solution by spin coating, dip coating, spray coating, or the like, and then heating and / or irradiating the thin film with light to form a polyimide resin film.

[0013] The polishing liquid according to this embodiment can be used to polish a surface containing a metal material. Examples of the metal material include metals such as copper, nickel, gold, silver, tin, zinc, platinum, bismuth, indium, and antimony, alloys of these metals, oxides of these metals, and oxides of alloys of these metals. The polishing liquid according to this embodiment can be used to polish a surface containing at least one selected from the group consisting of copper, copper alloys, oxides of copper, and oxides of copper alloys.

[0014] The polishing liquid according to this embodiment contains abrasive grains, iron ions, and an organic acid. The polishing liquid according to this embodiment can polish carbon materials and metal materials at an excellent polishing rate. The polishing liquid according to this embodiment can achieve a polishing rate of, for example, 100 nm / min or more for carbon materials, as evaluated in the Examples described below. Furthermore, the polishing liquid according to this embodiment can achieve a polishing rate of, for example, 30 nm / min or more for metal materials, as evaluated in the Examples described below.

[0015] The reason why the effect of being able to polish carbon materials and metal materials at an excellent polishing rate is obtained is not clear, but the following reasons are given as examples. However, the reason for the above effect is not limited to the following. That is, when the iron ions and organic acid modify the carbon material, the molecular chains (carbon-carbon bonds, etc.) of the carbon material are cut, reducing the mechanical strength of the carbon material. It is presumed that this allows the carbon material to be polished at an excellent polishing rate. Furthermore, when the organic acid modifies the metal material, the mechanical strength of the metal material is reduced. It is presumed that the abrasive grains then allow the metal material to be polished at an excellent polishing rate.

[0016] The polishing liquid according to this embodiment can be used, for example, for polishing in a wiring formation process of a semiconductor device. The polishing liquid according to this embodiment can be suitably used for polishing carbon materials used as constituent materials of hard masks, as well as for polishing interlayer insulating films using carbon materials. The polishing liquid according to this embodiment can also be suitably used for polishing metal materials used as constituent materials of metal wiring.

[0017] Examples of abrasive grains include silica particles, cerium oxide (ceria) particles, cerium hydroxide particles, aluminum oxide (alumina) particles, silicon nitride particles, zirconium oxide (zirconia: yttria-doped zirconia particles, etc.) particles, titanium oxide (titania) particles, yttrium oxide (yttria) particles, silicon carbide particles, diamond particles, and polymer particles. From the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate and of reducing the occurrence of defects such as scratches on the polished surface of the object to be polished and improving the flatness of the polished surface, the abrasive grains may include particles having a Mohs hardness of less than 8, particles having a Mohs hardness of 5 or more but less than 8, particles having a Mohs hardness of 5 to 7, particles having a Mohs hardness of 6 to 7, or at least one selected from the group consisting of silica particles and cerium oxide particles. The Mohs hardness refers to a value measured using a Mohs hardness scale on a bulk material having the same composition as the abrasive grains.

[0018] The polishing liquid according to the present embodiment contains abrasive grains. When silica particles are contained as abrasive grains, examples of the silica particles include colloidal silica, amorphous silica, crystalline silica, fused silica, spherical silica, synthetic silica, and hollow silica. When the polishing liquid contains abrasive grains, colloidal silica may be contained as the abrasive grains from the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate, and from the viewpoint of preventing defects such as scratches from occurring on the surface of the object to be polished after polishing, and easily improving the flatness of the surface to be polished.

[0019] The average particle size of the abrasive grains may be 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, 50 nm or more, 55 nm or more, or 60 nm or more, from the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate because a sufficient physical polishing ability per abrasive grain is easily ensured. The average particle size of the abrasive grains may be 1000 nm or less, 800 nm or less, 600 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 190 nm or less, 180 nm or less, 150 nm or less, 120 nm or less, 100 nm or less, 80 nm or less, or 70 nm or less, from the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate because a sufficient number of abrasive grains per unit area in contact with the polished surface is easily ensured. From these viewpoints, the average particle size of the abrasive grains may be 10 to 1000 nm, 10 to 600 nm, 10 to 200 nm, 10 to 100 nm, 10 to 80 nm, 15 to 190 nm, 20 to 180 nm, 30 to 100 nm, 30 to 200 nm, 30 to 80 nm, 50 to 200 nm, 50 to 100 nm, or 50 to 80 nm.

[0020] The "average particle size" refers to the secondary particle size of the abrasive grains and can be obtained by measuring the particle size of the abrasive grains in the polishing liquid or the particle size of the abrasive grains before being added to the polishing liquid. The average particle size can be measured using a light diffraction / scattering particle size distribution analyzer, or by preparing a sample in which the abrasive grains are dispersed in water. For example, using a COULTER N4SD manufactured by COULTER Electronics, the measurement is performed under the following conditions: measurement temperature: 20°C, solvent refractive index: 1.333 (water), particle refractive index: Unknown (setting), solvent viscosity: 1.005 cp (water), run time: 200 seconds, laser incident angle: 90°, intensity (corresponding to scattering intensity, turbidity): 5E+04 to 4E+05. If the intensity is higher than 4E+05, the sample can be diluted with water for measurement. Colloidal particles are usually obtained in a state of being dispersed in water, and therefore can be appropriately diluted and measured so that the scattering intensity falls within the above-mentioned range.

[0021] From the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate, the content of silica particles in the abrasive grains may be 50% by mass or more, more than 50% by mass, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, or 99% by mass or more, based on the total mass of the abrasive grains (all abrasive grains contained in the polishing liquid). The abrasive grains may be composed of silica particles (substantially 100% by mass of the abrasive grains contained in the polishing liquid are silica particles).

[0022] The polishing liquid according to this embodiment may not contain aluminum oxide (alumina) particles, and the abrasive grains may not contain aluminum oxide (alumina). The content of aluminum oxide (alumina) particles may be 0.01% by mass or less, less than 0.01% by mass, 0.001% by mass or less, or 0.0001% by mass or less, based on the total mass of the polishing liquid.

[0023] The polishing liquid according to this embodiment may not contain zirconia particles, and the abrasive grains may not contain zirconia. The content of zirconia particles may be 0.01 mass % or less, less than 0.01 mass %, 0.001 mass % or less, or 0.0001 mass % or less, based on the total mass of the polishing liquid.

[0024] The content of the abrasive grains may be in the following ranges based on the total mass of the polishing liquid. The content of the abrasive grains may be 20% by mass or less, 15% by mass or less, 10% by mass or less, 8% by mass or less, 5% by mass or less, 3% by mass or less, or 1% by mass or less based on the total mass of the polishing liquid, from the viewpoint that the amount of abrasive grains per unit area of ​​the polished surface is reduced, which facilitates preferential contact of iron ions with the polished surface and promotes modification of the carbon material, making it easier to polish the carbon material at a high polishing rate, and from the viewpoint that the occurrence of scratches is easily suppressed. The content of the abrasive grains may be 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 3% by mass or more, or 5% by mass or more, from the viewpoint that it is easier to polish metal materials at a high polishing rate.

[0025] The mass ratio of the abrasive grain content to the iron ion content (abrasive grain content / iron ion content) may be within the following ranges. The mass ratio may be 10,000 or less, 8,000 or less, 6,000 or less, 5,000 or less, 4,000 or less, 3,000 or less, 2,500 or less, 2,000 or less, 1,500 or less, 1,000 or less, 800 or less, 700 or less, 600 or less, or 500 or less, from the viewpoint of easily polishing a carbon material at a high polishing rate by reducing the amount of abrasive grains per unit area of ​​the polished surface, thereby accelerating the modification of the carbon material. The mass ratio may be 1 or more, 5 or more, 10 or more, 30 or more, 40 or more, 50 or more, 60 or more, 70 or more, 80 or more, 90 or more, or 100 or more, from the viewpoint of easily polishing a metal material at a high polishing rate. The mass ratio may be 400 or less, 300 or less, 250 or less, 200 or less, 150 or less, or 100 or less, or 150 or more, 200 or more, 300 or more, or 400 or more. From these viewpoints, the mass ratio may be 1 to 10,000, 1 to 5,000, 1 to 1,000, 1 to 500, 5 to 10,000, 5 to 5,000, 5 to 1,000, 5 to 500, 10 to 10,000, 5 to 5,000, 10 to 1,000, 10 to 500, 50 to 10,000, 50 to 5,000, 50 to 1,000, or 50 to 500.

[0026] The polishing liquid according to this embodiment contains iron ions. The iron ions are Fe, from the viewpoint of easily polishing carbon materials at an excellent polishing rate. ２＋ , and Fe ３＋ It may contain at least one selected from the group consisting of:

[0027] By using an iron ion supplying agent to prepare a polishing liquid, it is possible to obtain a polishing liquid containing iron ions. The polishing liquid according to this embodiment may contain an iron ion supplying agent. The iron ion supplying agent supplies iron ions to the polishing liquid.

[0028] Examples of iron ion supplying agents include iron ion salts and hydrates of such salts. The iron ion salt may include at least one selected from the group consisting of inorganic salts and organic salts. Examples of inorganic salts include iron nitrate, iron sulfate, iron boride, iron chloride, iron bromide, iron iodide, iron phosphate, and iron fluoride. Examples of organic salts include iron triformate, iron diformate, iron acetate, iron propionate, iron oxalate, iron malonate, iron succinate, iron malate, iron glutarate, iron tartrate, iron lactate, and iron citrate. The iron ion salt (inorganic salt, organic salt, etc.) may include a ligand such as ammonium or water.

[0029] In a polishing liquid containing an iron ion supplying agent, the iron ion supplying agent may be present in a dissociated state into iron ions and anions derived from the iron ion supplying agent. The polishing liquid according to this embodiment may contain at least one selected from the group consisting of nitrate ions and acetate ions, from the viewpoint of easily polishing carbon materials at a high polishing rate. The polishing liquid according to this embodiment may contain at least one selected from the group consisting of iron nitrate, iron nitrate hydrate, and iron acetate, from the viewpoint of easily polishing carbon materials at a high polishing rate, relatively little contamination of the polishing apparatus, substrate, etc., and inexpensive and easily available.

[0030] The content of iron ions may be in the following ranges based on the total mass of the polishing liquid: from the viewpoint of easily polishing carbon materials at an excellent polishing rate, the content of iron ions may be 0.0001 mass % or more, 0.0005 mass % or more, 0.001 mass % or more, 0.0012 mass % or more, 0.0014 mass % or more, 0.002 mass % or more, 0.003 mass % or more, 0.004 mass % or more, 0.005 mass % or more, 0.0055 mass % or more, 0.006 mass % or more, 0.007 mass % or more 0.008% by mass or more, 0.009% by mass or more, 0.01% by mass or more, more than 0.01% by mass, 0.011% by mass or more, 0.02% by mass or more, 0.03% by mass or more, 0.04% by mass or more, It may be 0.05% by mass or more, 0.06% by mass or more, 0.07% by mass or more, 0.08% by mass or more, 0.09% by mass or more, 0.1% by mass or more, more than 0.1% by mass, or 0.11% by mass or more. The content of iron ions is 10% by mass or less, 8% by mass or less, 6% by mass or less, 5% by mass or less, 4% by mass or less, 3% by mass or less, 2% by mass or less, 1% by mass or less, less than 1% by mass, 0.9 mass%. % by mass or less, 0.8% by mass or less, 0.7% by mass or less, 0.6% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, 0.15% by mass or less, 0 12% by mass or less, 0.1% by mass or less, less than 0.1% by mass, 0.09% by mass or less, 0.08% by mass or less, 0.07% by mass or less, 0.06% by mass or less, 0.05% by mass or less. 0.04% by mass or less, 0.03% by mass or less, 0.02% by mass or less, 0.015% by mass or less, 0.012% by mass or less, 0.01% by mass or less, or less than 0.01% by mass. From these viewpoints, the iron ion content may be 0.0001 to 10 mass%, 0.0001 to 5 mass%, 0.0001 to 1 mass%, 0.0005 to 0.5 mass%, 0.001 to 0.2 mass%, or 0.0014 to 0.12 mass%. The content of the iron ion supplying agent may be adjusted so that the iron ion content in the polishing liquid falls within the above-mentioned ranges. When converting the iron ion content (unit: mass%) to the content (unit: mM), a specific gravity of 1 may be used for the polishing liquid. When the iron ion content is 0.001 to 10 mass%, the iron ion content can be converted to 0.018 to 179 mM.

[0031] The polishing liquid according to this embodiment contains an organic acid component. Examples of the organic acid component include organic acids and their salts (e.g., alkali metal salts such as sodium salts; alkaline earth metal salts such as calcium salts). The use of the organic acid component modifies carbon materials and metal materials, enabling the carbon materials and metal materials to be polished at an excellent polishing rate. When the organic acid component is used in the absence of iron ions, the effect of improving the polishing rate for carbon materials cannot be obtained. However, when the organic acid component is used in the presence of iron ions, the polishing rate for carbon materials can be improved.

[0032] The polishing liquid according to this embodiment may contain an oxidizing agent such as hydrogen peroxide, as will be described later. In such a polishing liquid, the interaction between iron ions and the oxidizing agent (e.g., hydrogen peroxide) may accelerate decomposition of the oxidizing agent, potentially impairing the storage stability of the polishing liquid. However, the decomposition of the oxidizing agent can be suppressed by using an organic acid component.

[0033] Although the reason why the organic acid component provides the above-mentioned effect is not clear, it is presumed that the organic acid component dissociates in the polishing solution, and the dissociated organic acid component chelates the iron ions, thereby suppressing the decomposition of the oxidizing agent by the iron ions. However, the reason why the above-mentioned effect is provided is not limited to this content. "Dissociation" refers to the dissociation of at least one acid group (e.g., a carboxy group (-COOH)) of the organic acid component in the polishing solution into a cation (e.g., a proton (H ＋ )) is released, and the acid group is converted to an anionic group (e.g., —COO － ) means that it exists in a state of

[0034] The organic acid component may contain an organic acid component that does not have a carbon-carbon unsaturated bond, from the viewpoint of making it easier to keep the oxidizing agent more stable and to stabilize the polishing rate for carbon materials and metal materials. The reason why the stability of the oxidizing agent is improved when the organic acid component does not have a carbon-carbon unsaturated bond is not clear, but it is presumed that one reason is that the reactivity of carbon-carbon unsaturated bonds is relatively high, and therefore, when the organic acid component does not have a carbon-carbon unsaturated bond, deterioration due to reaction between the oxidizing agent and the organic acid component in the polishing liquid is less likely to occur. However, the reason for obtaining the above-mentioned effect is not limited to this content.

[0035] Examples of organic acids include saturated fatty acids such as formic acid, acetic acid, and propionic acid; dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, and adipic acid; hydroxy acids such as malic acid and citric acid; and amino acids described below. The organic acid may or may not contain malic acid.

[0036] The polishing liquid may contain at least one amino acid component selected from the group consisting of amino acids and amino acid derivatives (excluding compounds containing iron ions or compounds that fall under the category of oxidizing agents) in order to facilitate the polishing of carbon materials and metal materials at an excellent polishing rate. Amino acids are compounds having both amino and carboxyl functional groups. Examples of amino acid derivatives include amino acid esters, amino acid salts, and peptides. The amino acid component can be used as a pH adjuster to adjust the pH of the polishing liquid.

[0037] The amino acid components include glycine, α-alanine, β-alanine (also known as 3-aminopropanoic acid), 2-aminobutyric acid, norvaline, valine, leucine, norleucine, isoleucine, alloisoleucine, phenylalanine, proline, sarcosine, ornithine, lysine, serine, threonine, allothreonine, homoserine, tyrosine, 3,5-diiodo-tyrosine, β-(3,4-dihydroxyphenyl)-alanine, thyroxine, 4-hydroxy-proline, cysteine, methionine, ethionine, lanthionine, cystathionine, cystine, and cysteine. Examples of amino acid components include glycine, aspartic acid, glutamic acid, S-(carboxymethyl)-cysteine, 4-aminobutyric acid, asparagine, glutamine, azaserine, arginine, canavanine, citrulline, δ-hydroxy-lysine, creatine, kynurenine, histidine, 1-methyl-histidine, 3-methyl-histidine, ergothioneine, tryptophan, glycylglycine, glycylglycylglycine, vasopressin, oxytocin, cassinin, eledoisin, glucagon, secretin, proopiomelanocortin, enkephalin, prodynorphin, etc. The amino acid component may contain at least one selected from the group consisting of glycine and β-alanine, from the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate.

[0038] From the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate, the content of glycine in the organic acid or amino acid may be 50% by mass or more, more than 50% by mass, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, or 99% by mass or more, based on the total mass of the organic acid (all organic acids contained in the polishing liquid) or the total mass of the amino acid (all amino acids contained in the polishing liquid). The organic acid or amino acid may be composed of glycine (substantially 100% by mass of the organic acid or amino acid contained in the polishing liquid is glycine).

[0039] From the viewpoint of easily stabilizing the removal rate of carbon materials and metal materials, the content of the organic acid component may be within the following ranges based on the total mass of the polishing liquid. The content of the organic acid component may be 0.01 mass% or more, 0.05 mass% or more, 0.1 mass% or more, 0.2 mass% or more, 0.3 mass% or more, 0.5 mass% or more, 1 mass% or more, 1.5 mass% or more, 2 mass% or more, 2.5 mass% or more, or 3 mass% or more. The content of the organic acid component may be 10 mass% or less, 5 mass% or less, 3 mass% or less, 1 mass% or less, 0.8 mass% or less, 0.5 mass% or less, or 0.3 mass% or less. From these viewpoints, the content of the organic acid component may be 0.01 to 10% by mass, 0.01 to 5% by mass, 0.01 to 3% by mass, 0.05 to 10% by mass, 0.05 to 5% by mass, 0.05 to 3% by mass, 0.1 to 10% by mass, 0.1 to 5% by mass, or 0.1 to 3% by mass. The content of the amino acid component may be within the above-mentioned ranges.

[0040] The mass ratio of the content of the organic acid component to the content of the abrasive grains (content of organic acid component / content of abrasive grains) may be within the following ranges, from the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate. The mass ratio may be 0.01 or more, 0.05 or more, 0.1 or more, or 0.3 or more. The mass ratio may be 30 or less, 20 or less, 10 or less, 5 or less, or 3 or less. From these viewpoints, the mass ratio may be 0.01 to 30, 0.05 to 20, 0.1 to 10, or 0.3 to 5. The mass ratio of the content of the amino acid component to the content of the abrasive grains (content of amino acid component / content of abrasive grains) may be within the above-mentioned ranges.

[0041] From the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate, the mass ratio of the content of the organic acid component to the content of iron ions (organic acid content / iron ion content) may be within the following ranges. The mass ratio may be 0.1 or more, 0.5 or more, 1 or more, 2 or more, 10 or more, 50 or more, 100 or more, 150 or more, 200 or more, or 250 or more. The mass ratio may be 3000 or less, 2500 or less, 2200 or less, 2000 or less, 1500 or less, 1000 or less, 800 or less, 600 or less, 500 or less, 400 or less, 350 or less, 250 or less, 200 or less, 150 or less, 100 or less, 50 or less, or 30 or less. From these viewpoints, the mass ratio may be 0.1 to 3000, 0.1 to 2000, 0.1 to 500, 0.1 to 300, 0.1 to 100, 0.1 to 30, 1 to 3000, 1 to 2000, 1 to 500, 1 to 300, 1 to 100, 1 to 30, 2 to 3000, 2 to 2000, 2 to 500, 2 to 300, 2 to 100, or 2 to 30. The mass ratio of the content of amino acid components to the content of iron ions (amino acid content / iron ion content) may be within the above-mentioned range.

[0042] The polishing liquid according to this embodiment may contain an oxidizing agent (an oxidizing agent for carbon materials; excluding compounds corresponding to iron ions or compounds containing iron ions). The use of an oxidizing agent further modifies the carbon materials and metal materials, and the polishing rate for the carbon materials and metal materials is likely to be improved. When an oxidizing agent is used in the absence of iron ions, the effect of improving the polishing rate for the carbon materials cannot be obtained. However, when an oxidizing agent is used in the presence of iron ions, the polishing rate for the carbon materials can be improved.

[0043] Examples of oxidizing agents include hydrogen peroxide, nitric acid, potassium periodate, hypochlorous acid, and ozone water. When the substrate to be polished is a silicon substrate containing integrated circuit elements, the oxidizing agent may contain an oxidizing agent that does not contain non-volatile components, from the viewpoint of avoiding contamination by alkali metals, alkaline earth metals, halides, and the like, and may contain hydrogen peroxide. The oxidizing agent may contain a peroxide, from the viewpoint of facilitating polishing of carbon materials and metal materials at an excellent polishing rate. As the oxidizing agent, a compound having a weaker redox potential than iron ions can be used.

[0044] The content of the oxidizing agent may be in the following ranges based on the total mass of the polishing liquid. From the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate, the content of the oxidizing agent may be 0.1 mass% or more, 0.5 mass% or more, 1 mass% or more, 1.5 mass% or more, 1.7 mass% or more, 2 mass% or more, 2.5 mass% or more, 3 mass% or more, 3.5 mass% or more, or 4 mass% or more. The content of the oxidizing agent may be 20 mass% or less, 15 mass% or less, 10 mass% or less, 8 mass% or less, 6 mass% or less, 5 mass% or less, 4.5 mass% or less, or 4 mass% or less. From these viewpoints, the content of the oxidizing agent may be 0.1 to 20 mass%, 0.1 to 10 mass%, 0.1 to 5 mass%, 1 to 20 mass%, 1 to 10 mass%, 1 to 5 mass%, 2 to 20 mass%, 2 to 10 mass%, 2 to 5 mass%, 3 to 10 mass%, or 3 to 5 mass%.

[0045] The mass ratio of the oxidizing agent content to the abrasive grain content (oxidizing agent content / abrasive grain content) may be within the following ranges from the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate. The mass ratio may be 0.01 or more, 0.05 or more, 0.1 or more, 0.5 or more, or 0.8 or more. The mass ratio may be 30 or less, 20 or less, 10 or less, 5 or less, or 4 or less. From these viewpoints, the mass ratio may be 0.01 to 30, 0.05 to 20, 0.1 to 10, or 0.5 to 5.

[0046] The mass ratio of the oxidizing agent content to the iron ion content (oxidizing agent content / iron ion content) may be within the following ranges. From the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate, the mass ratio may be 10 or more, 50 or more, 100 or more, 150 or more, 200 or more, 250 or more, 300 or more, or 350 or more. From the viewpoint of easily polishing carbon materials at an excellent polishing rate, the mass ratio may be 3000 or less, 2500 or less, 2000 or less, 1500 or less, 1000 or less, 800 or less, 600 or less, 500 or less, 450 or less, 400 or less, or 370 or less. From these viewpoints, the mass ratio may be 10 to 3000, 10 to 2000, 10 to 500, 100 to 3000, 100 to 2000, 100 to 500, 200 to 3000, 200 to 2000, 200 to 500, 300 to 3000, 300 to 2000, or 300 to 500.

[0047] The polishing liquid according to this embodiment may contain an organic solvent (excluding compounds containing iron ions, oxidizing agents, or compounds corresponding to organic acid components). The use of an organic solvent may facilitate an improvement in the polishing rate of hydrophobic carbon materials (e.g., carbon materials with low dielectric constants). Furthermore, the use of an organic solvent may facilitate the suppression of decomposition of oxidizing agents (e.g., hydrogen peroxide), making it easier to polish carbon materials and metal materials at a high polishing rate.

[0048] The organic solvent may be any solvent that can be mixed with water. Examples of the organic solvent include carbonate esters such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate; lactone compounds such as butyrolactone and propiolactone; glycol compounds such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol; and derivatives of glycol compounds such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, and diethylene glycol monomethyl ether. glycol monoethers (e.g., glycol monoalkyl ethers) such as glycol monoethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether, tripropylene glycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monopropyl ether, diethylene glycol monopropyl ether, dipropylene glycol monopropyl ether, triethylene glycol monopropyl ether, tripropylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monobutyl ether, diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether, triethylene glycol monobutyl ether, and tripropylene glycol monobutyl ether;Glycol diethers such as ethylene glycol dimethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, triethylene glycol dimethyl ether, tripropylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol diethyl ether, diethylene glycol diethyl ether, dipropylene glycol diethyl ether, triethylene glycol diethyl ether, tripropylene glycol diethyl ether, ethylene glycol dipropyl ether, propylene glycol dipropyl ether, diethylene glycol dipropyl ether, dipropylene glycol dipropyl ether, triethylene glycol dipropyl ether, tripropylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol dibutyl ether, diethylene glycol dibutyl ether, dipropylene glycol dibutyl ether, triethylene glycol dibutyl ether, and tripropylene glycol dibutyl ether; tetrahydrofuran, di Ether compounds such as hexane, dimethoxyethane, polyethylene oxide, ethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate; alcohols such as methanol, ethanol, propanol, n-butanol, n-pentanol, n-hexanol, and isopropanol; 2-methoxyethanol, 2-ethoxyethanol, 2-(2-methoxy)ethoxyethanol, 2-(2-butoxyethoxy)ethanol, 2-propoxyethanol, and 2-butoxyethanol. alkoxy alcohols such as 2-isopropoxyethanol, 3-methoxy-3-methyl-1-butanol, 2-(methoxymethoxy)ethanol, 2-isopropoxyethanol, 2-butoxyethanol, 2-isopentyloxyethanol, 1-propoxy-2-propanol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, 3-methoxy-3-methylbutanol, 1-methoxy-2-butanol, and glycol monoethers; ketones such as acetone and methyl ethyl ketone; phenol; dimethylformamide; N-methylpyrrolidone;Examples include ethyl acetate, ethyl lactate, sulfolane, etc.

[0049] The organic solvent may contain an alkoxy alcohol or 3-methoxy-3-methyl-1-butanol, from the viewpoint of easily improving the polishing rate for hydrophobic carbon materials.

[0050] The content of the organic solvent may be in the following ranges based on the total mass of the polishing liquid. From the viewpoints of easily obtaining sufficient wettability of the polishing liquid to the substrate and easily improving the polishing rate for the hydrophobic carbon material, the content of the organic solvent may be 0.1 mass % or more, 0.2 mass % or more, 0.5 mass % or more, 1 mass % or more, 2 mass % or more, 2.5 mass % or more, or 3 mass % or more. From the viewpoints of easily improving the polishing rate for the hydrophobic carbon material and easily reducing the possibility of ignition, the content of the organic solvent may be 95 mass % or less, 50 mass % or less, 30 mass % or less, 10 mass % or less, 8 mass % or less, 6 mass % or less, 5 mass % or less, 4 mass % or less, or 3 mass % or less. From these viewpoints, the content of the organic solvent may be 0.1 to 95 mass%, 0.1 to 50 mass%, 0.1 to 5 mass%, 1 to 95 mass%, 1 to 50 mass%, 1 to 5 mass%, 2 to 95 mass%, 2 to 50 mass%, or 2 to 5 mass%.

[0051] The polishing liquid according to this embodiment may contain additives other than the above-mentioned components, such as a pH adjuster and a polymer material.

[0052] The polishing liquid according to this embodiment may contain a base component as a pH adjuster, such as sodium hydroxide, ammonia (e.g., aqueous ammonia), potassium hydroxide, or calcium hydroxide.

[0053] The content of the base component may be in the following ranges based on the total mass of the polishing liquid. The content of the base component may be more than 0 mass%, 0.00001 mass% or more, 0.00005 mass% or more, 0.0001 mass% or more, 0.0005 mass% or more, 0.001 mass% or more, or 0.005 mass% or more. The content of the base component may be 10 mass% or less, 5 mass% or less, 1 mass% or less, 0.5 mass% or less, 0.1 mass% or less, or 0.05 mass% or less.

[0054] The polishing liquid according to this embodiment may contain water. The water content in the polishing liquid may be the remainder obtained by subtracting the contents of other components from the total amount of the polishing liquid. The water content may be 50% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more, based on the total mass of the polishing liquid. The polishing liquid according to this embodiment may be stored as a stock solution for the polishing liquid having a lower water content than that used during polishing. In this case, the polishing liquid can be obtained by diluting the stock solution for the polishing liquid with water during polishing.

[0055] From the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate, the pH of the polishing liquid according to this embodiment may be less than 9.0, 8.5 or less, 8.0 or less, 7.5 or less, 7.0 or less, less than 7.0, 6.5 or less, 6.0 or less, less than 6.0, 5.5 or less, 5.2 or less, 5.0 or less, less than 5.0, 4.8 or less, 4.6 or less, 4.5 or less, 4.4 or less, or 4.3 or less. From the viewpoint of easily polishing carbon materials and metal materials at an excellent polishing rate, the pH of the polishing liquid may be 1.0 or more, 1.2 or more, 1.5 or more, 2.0 or more, more than 2.0, 2.2 or more, 2.4 or more, 2.6 or more, 2.8 or more, 3.0 or more, more than 3.0, 3.2 or more, 3.4 or more, 3.6 or more, 3.8 or more, 4.0 or more, 4.1 or more, or 4.2 or more. From these viewpoints, the pH of the polishing liquid may be 1.0 or more and less than 9.0, 1.0 to 8.0, 1.0 to 7.0, 1.0 to 6.0, 1.0 to 5.0, 1.0 to 4.5, 2.0 or more and less than 9.0, 2.0 to 8.0, 2.0 to 7.0, 2.0 to 6.0, 2.0 to 5.0, 2.0 to 4.5, 3.0 or more and less than 9.0, 3.0 to 8.0, 3.0 to 7.0, 3.0 to 6.0, 3.0 to 5.0, or 3.0 to 4.5. The pH of the polishing liquid is defined as the pH at a liquid temperature of 25°C.

[0056] The pH of the polishing solution according to this embodiment can be measured with a pH meter (for example, Model (F-51), manufactured by Horiba, Ltd.). For example, a phthalate pH standard solution (pH: 4.01), a neutral phosphate pH standard solution (pH: 6.86), and a borate pH standard solution (pH: 9.18) are used as calibration solutions to perform three-point calibration of the pH meter, and then the electrodes of the pH meter are placed in the polishing solution, and the pH value is measured after stabilization for at least two minutes. At this time, the liquid temperatures of the calibration solutions and the polishing solution are set to 25°C.

[0057] The polishing method according to this embodiment includes a polishing step of polishing a carbon material using the polishing liquid according to this embodiment. In the polishing step, a surface to be polished containing a carbon material may be polished using the polishing liquid according to this embodiment, or the surface of a material to be polished containing a carbon material may be polished. In the polishing step, a surface to be polished of a hard mask containing a carbon material may be polished using the polishing liquid according to this embodiment. In the polishing step, a surface to be polished containing a metal material may be polished using the polishing liquid according to this embodiment, or the surface of a material to be polished containing a metal material may be polished. The polishing liquid used in the polishing step may be a polishing liquid obtained by diluting a polishing liquid storage liquid with water. The surface to be polished may have a layer containing at least one material selected from the group consisting of a carbon material and a metal material.

[0058] In the polishing process, for example, the surface to be polished of the substrate is pressed against the polishing cloth of the polishing table, and a predetermined pressure is applied to the substrate from the side of the substrate opposite the surface to be polished (the back surface of the substrate). In this state, the polishing liquid according to this embodiment is supplied between the surface to be polished of the substrate and the polishing cloth, and the substrate is moved relative to the polishing table, thereby polishing the surface to be polished.

[0059] As the polishing apparatus, for example, when polishing with an abrasive cloth, a general polishing apparatus having a holder capable of holding a substrate to be polished and a polishing platen connected to a motor or the like whose rotation speed can be changed and onto which an abrasive cloth can be attached can be used. There are no particular restrictions on the abrasive cloth, and general nonwoven fabrics, polyurethane foams, porous fluororesins, etc. can be used.

[0060] There are no restrictions on the polishing conditions, but the rotation speed of the polishing platen should be set to 200 rpm (rpm = min) so that the substrate does not jump out. －１ ) or less. The pressure with which the substrate (semiconductor substrate, etc.) having the surface to be polished is pressed against the polishing cloth may be 1 to 100 kPa, or 5 to 50 kPa, from the viewpoint of easily achieving uniformity of the polishing rate within the surface to be polished and flatness of the pattern. During polishing, a polishing liquid can be continuously supplied to the polishing cloth by a pump or the like. There is no limit to the amount of supply, but the surface of the polishing cloth may be constantly covered with the polishing liquid.

[0061] In order to maintain the same surface condition of the polishing cloth during polishing (e.g., CMP), a polishing cloth conditioning step may be performed before polishing. For example, a polishing cloth can be conditioned with a liquid containing at least water using a dresser with diamond particles. Subsequently, after performing the polishing method according to this embodiment, a substrate cleaning step may be further performed. After polishing, the substrate may be thoroughly washed in running water, and then dried using a spin dryer or the like to remove water droplets adhering to the substrate. Alternatively, the substrate may be dried after performing a known cleaning method (e.g., a method in which a commercially available cleaning solution is poured over the substrate surface while a rotating polyurethane brush is pressed against the substrate with a constant pressure to remove deposits on the substrate).

[0062] The component manufacturing method according to the present embodiment includes a component fabrication step in which a component is obtained using a polished member (a polished member containing a carbon material and / or a metal material) polished by the polishing method according to the present embodiment. The polished member (a polished member containing a carbon material) polished by the polishing method according to the present embodiment may be used as a hard mask. The component according to the present embodiment is a component obtained by the component manufacturing method according to the present embodiment. The component according to the present embodiment is not particularly limited, and may be an electronic component (e.g., a semiconductor component such as a semiconductor package), a wafer (e.g., a semiconductor wafer), or a chip (e.g., a semiconductor chip). As one aspect of the component manufacturing method according to the present embodiment, an electronic component is obtained using a polished member polished by the polishing method according to the present embodiment. As one aspect of the component manufacturing method according to the present embodiment, a semiconductor component (e.g., a semiconductor package) is obtained using a polished member polished by the polishing method according to the present embodiment. The component manufacturing method according to the present embodiment may include a polishing step in which a polished member is polished by the polishing method according to the present embodiment before the component fabrication step.

[0063] The component manufacturing method according to this embodiment may include, as one aspect of the component manufacturing process, a singulation step of singulating a polished member (a polished member containing a carbon material and / or a metal material) polished by the polishing method according to this embodiment. The singulation step may be, for example, a step of dicing a wafer (e.g., a semiconductor wafer) polished by the polishing method according to this embodiment to obtain chips (e.g., semiconductor chips). As one aspect of the component manufacturing method according to this embodiment, the electronic component manufacturing method according to this embodiment may include a step of singulating a polished member polished by the polishing method according to this embodiment to obtain electronic components (e.g., semiconductor components). As one aspect of the component manufacturing method according to this embodiment, the semiconductor component manufacturing method according to this embodiment may include a step of singulating a polished member polished by the polishing method according to this embodiment to obtain semiconductor components (e.g., semiconductor packages).

[0064] The component manufacturing method according to this embodiment may include, as one aspect of the component manufacturing process, a connecting process for connecting (e.g., electrically connecting) a polished member (a polished member containing a carbon material and / or a metal material) polished by the polishing method according to this embodiment to another connected object. The connected object to be connected to the polished member polished by the polishing method according to this embodiment is not particularly limited and may be the polished member polished by the polishing method according to this embodiment, or may be a connected object different from the polished member polished by the polishing method according to this embodiment. In the connecting process, the polished member and the connected object may be directly connected (connected in a state where the polished member and the connected object are in contact), or the polished member and the connected object may be connected via another member (such as a conductive member). The connecting process may be performed before the singulation process, after the singulation process, or before or after the singulation process.

[0065] The connecting step may be a step of connecting a polished surface of a member to be polished that has been polished by the polishing method according to this embodiment to a connected body, or a step of connecting a connecting surface of a member to be polished that has been polished by the polishing method according to this embodiment to a connecting surface of a connected body. The connecting surface of the member to be polished may be a polished surface polished by the polishing method according to this embodiment. The connecting step can obtain a connected body comprising a member to be polished and a connected body. In the connecting step, if the connecting surface of the member to be polished has a metal portion, the connected body may be brought into contact with the metal portion. In the connecting step, if the connecting surface of the member to be polished has a metal portion and the connecting surface of the connected body has a metal portion, the metal portions may be brought into contact with each other. The metal portion may contain copper.

[0066] The device according to this embodiment (for example, an electronic device such as a semiconductor device) includes a polished member (a polished member containing a carbon material and / or a metal material) polished by the polishing method according to this embodiment, and at least one member selected from the group consisting of the parts according to this embodiment.

[0067] Hereinafter, the present disclosure will be described in more detail with reference to examples, but the present disclosure is not limited to these examples as long as they do not deviate from the technical concept of the present disclosure.

[0068] Preparation of CMP Polishing Liquid Example 1 Iron (III) nitrate nonahydrate and abrasive grains (colloidal silica, product name: PL-10H, average particle size: 179 nm, old Mohs hardness: 6 to 7) were mixed with deionized water. Next, glycine, a 30 mass% aqueous solution of hydrogen peroxide, and MMB were added to obtain a CMP polishing liquid. Based on the total mass of the CMP polishing liquid, the abrasive grain content (solid content of silica) was 1 mass%, the iron (III) nitrate nonahydrate content was 0.08 mass% (iron ion content: 0.011 mass%), the glycine content was 3.00 mass%, the hydrogen peroxide content (content of hydrogen peroxide itself) was 4.00 mass%, and the MMB content was 3.00 mass%.

[0069] Example 2 A CMP polishing liquid was obtained in the same manner as in Example 1, except that the content of abrasive grains was changed to 5 mass %.

[0070] Example 3 A CMP polishing liquid was obtained in the same manner as in Example 1, except that the content of iron (III) nitrate nonahydrate was changed to 0.04 mass % (iron ion content: 0.0055 mass %).

[0071] Example 4 A CMP polishing liquid was obtained in the same manner as in Example 1, except that the content of iron (III) nitrate nonahydrate was changed to 0.12 mass % (iron ion content: 0.017 mass %).

[0072] Example 5 A CMP polishing liquid was obtained in the same manner as in Example 1, except that the glycine content was changed to 0.30 mass %.

[0073] Example 6 A CMP polishing liquid was obtained in the same manner as in Example 1, except that the glycine content was changed to 0.60 mass %.

[0074] Example 7 A CMP polishing liquid was obtained in the same manner as in Example 1, except that the glycine content was changed to 1.50 mass %.

[0075] Example 8 A CMP polishing solution was obtained in the same manner as in Example 1, except that glycine was changed to β-alanine and the β-alanine content was 0.30% by mass.

[0076] Example 9 A CMP polishing liquid was obtained in the same manner as in Example 1, except that glycine was changed to β-alanine and the β-alanine content was 4.00 mass %.

[0077] Comparative Example 1 A CMP polishing solution was obtained in the same manner as in Example 1, except that iron (III) nitrate nonahydrate was changed to a 0.1 mol / L aqueous zinc acetate solution and the zinc acetate content (content of zinc acetate itself) was 0.04 mass % (content of zinc ions: 0.013 mass %).

[0078] Comparative Example 2 A CMP polishing liquid was obtained in the same manner as in Example 1, except that no abrasive grains and no hydrogen peroxide were added.

[0079] <Measurement of Average Particle Size of Abrasive Grains> The average particle size of the abrasive grains in the above-mentioned CMP polishing liquid was measured using a COULTER N4SD manufactured by COULTER Electronics. As a result, in all Examples, there was no change in the average particle size of the abrasive grains before and after preparation of the polishing liquid.

[0080] <pH Measurement> The pH of the above-mentioned CMP polishing solution was measured using a "Model (F-51)" manufactured by Horiba, Ltd. Specifically, a phthalate pH standard solution (pH: 4.01), a neutral phosphate pH standard solution (pH: 6.86), and a borate pH standard solution (pH: 9.18) were used as calibration solutions to perform three-point calibration of the pH meter, and then the pH meter electrode was immersed in the CMP polishing solution, and the value was measured after stabilization for at least two minutes. The liquid temperatures of the calibration solutions and the CMP polishing solution were 25°C. The results are shown in Table 1.

[0081] <Measurement of Polishing Rate> A 12-inch diameter substrate having a 10 μm thick polyimide resin layer (HD7000 series, manufactured by HD Microsystems) on a silicon substrate was prepared as a test wafer for evaluation. A 12-inch diameter substrate having a 1.5 μm thick copper layer on a silicon substrate was also prepared as a test wafer for evaluation. Using the above-described CMP polishing solution, the polyimide resin layer and the copper layer were each polished (CMP) under the following polishing conditions. The difference in thickness of the polyimide resin layer before and after polishing was measured using an optical film thickness meter (F54-UV, manufactured by Filmetrics), and the difference in thickness of the copper layer before and after polishing was measured using a metal film thickness meter (WS-3000, manufactured by Napson). The polishing rates for the polyimide resin and copper were calculated based on the thickness difference between the polyimide resin layer and the copper layer and the polishing time. The results are shown in Tables 1 and 2.

[0082] [Polishing Conditions] Polishing apparatus: Applied Materials, Inc., trade name "Reflexion LK" Polishing pad: IK4250H (DuPont) Polishing pressure: 4 psi Platen rotation speed: 87 rpm Head rotation speed: 93 rpm CMP polishing solution supply rate: 300 mL / min Polishing time: 1 minute

[0083]

Claims

1. A CMP polishing liquid for polishing a workpiece containing a carbon material, the CMP polishing liquid containing abrasive grains, iron ions, and an organic acid.

2. The CMP polishing liquid according to claim 1, wherein the abrasive grains include particles having a Mohs hardness of less than 8.

3. The CMP polishing fluid of claim 1, wherein the abrasive comprises silica particles.

4. The CMP polishing liquid according to claim 1, wherein the content of the iron ions is 0.001 to 0.2 mass %.

5. The CMP polishing liquid according to claim 1, wherein the mass ratio of the content of the abrasive grains to the content of the iron ions is 50 to 500.

6. The CMP polishing liquid according to claim 1, further comprising an oxidizing agent.

7. The CMP polishing fluid of claim 6, wherein the oxidizing agent comprises a peroxide.

8. The CMP polishing liquid according to claim 1, further comprising an organic acid component.

9. The CMP polishing fluid according to claim 8, wherein the organic acid component comprises an amino acid component.

10. The CMP polishing liquid according to claim 8, wherein the content of the organic acid component is 0.1 to 5 mass %.

11. The CMP polishing liquid according to claim 1, further comprising an organic solvent.

12. The CMP polishing fluid of claim 11, wherein the organic solvent comprises 3-methoxy-3-methyl-1-butanol.

13. The CMP polishing liquid according to claim 1, having a pH of 1.0 to 7.

0.

14. The CMP polishing fluid of claim 1, wherein the carbon material comprises a polyimide resin.

15. The CMP polishing liquid according to claim 1, wherein the member to be polished further contains a metallic material.

16. The CMP polishing liquid according to claim 15, wherein the metal material comprises at least one selected from the group consisting of copper, a copper alloy, an oxide of copper, and an oxide of a copper alloy.

17. A polishing method comprising a step of polishing a workpiece containing a carbon material with the CMP polishing liquid according to any one of claims 1 to 16.

18. A method for producing a semiconductor device, comprising the steps of: obtaining a semiconductor device by using a polished member polished by the polishing method according to claim 17.

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