TW201700705A - Abrasive, storage liquid for abrasive and grinding method consisting of higher content of carbon-based material and an insulating material - Google Patents

Abstract

The present invention provides an abrasive which is an abrasive for removing at least a part of a carbon-based material by subjecting a matrix containing a carbon-based material and an insulating material to chemical mechanical polishing, wherein the carbon in the carbon-based material is measured by X-ray photoelectric spectroscopy method and reaches 60 atm%~95 atm% content of carbon, and the abrasive contains silica-containing abrasive grains, allylamine-based polymer and water. The content of the allylamine-based polymer with respect to abrasive grains has the mass ratio of 0.002 to 0.400, and the abrasive grains have a positive charge in the abrasive.

Description

Abrasive, polishing solution, and polishing method

The present invention relates to a method for chemically polishing a substrate containing a high carbon content carbon material and an insulating material by chemical mechanical polishing (hereinafter sometimes referred to as "CMP") to remove at least a part of the carbon-based material. An abrasive, a storage solution for an abrasive, and a polishing method.

In recent years, new microfabrication technologies have been developed along with the high integration and high performance of semiconductor integrated circuits (hereinafter referred to as "Large Scale Integration Circuits (LSI)"). CMP is one of such techniques, and is a technique frequently used in an LSI manufacturing process (particularly, planarization of an interlayer insulating material in a multilayer wiring forming step, formation of a metal plug, formation of an embedded wiring, etc.).

In addition, with the increase in the integration of the LSI or the improvement in performance, the pattern rule is required to be miniaturized. Recently, a double patterning process is mentioned as a process of great interest (see, for example, Patent Document 1 below). In the double patterning process, after the first pattern is formed by the first exposure and development, the second pattern is formed on the gap portion or the like of the first pattern by the second exposure and development.

As a method of double patterning, several processes have been proposed (for example, refer to Patent Document 2 below). An example of double patterning is illustrated using FIG. 1(a) to FIG. 1(f). First, a substrate including the substrate 1 and the ruthenium oxide 2 having a predetermined pattern and formed on the substrate 1 is prepared (Fig. 1 (a)). Then, a photoresist 3 is formed on the substrate 1 and the yttrium oxide 2 (Fig. 1(b)). The entire surface layer portion of the photoresist 3 is removed by dry etching in such a manner that the photoresist 3 having a predetermined thickness remains on the ruthenium oxide 2 (Fig. 1 (c)). The predetermined portion on the cerium oxide 2 in the photoresist 3 is removed by the exposure and development steps, and the groove portion 4 is formed in the photoresist 3 (Fig. 1 (d)). The portion of the yttrium oxide 2 exposed in the groove portion 4 is removed by dry etching (Fig. 1(e)). The photoresist 3 is subjected to a lift-off treatment to obtain ruthenium oxide 2 having a predetermined pattern (Fig. 1 (f)). [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei.

[Problems to be solved by the invention]

However, in the conventional method using dry etching, as shown in FIG. 1(c), slight unevenness (for example, unevenness of 10 nm or less) on the surface of the photoresist 3 cannot be eliminated, and sometimes the surface layer portion of the photoresist 3 (in the laminate) The thickness of the upper portion of the surface of the cerium oxide 2 in the direction is not uniform.

Previously, the thickness of the surface layer portion of the photoresist was not tolerable, but with the development of design rules in recent years, the influence could not be ignored. For example, in the recess step performed after the photoresist is applied, the thickness unevenness of the surface layer portion of the photoresist is further increased. As a result, the shape of the element is deteriorated, the depth of focus is reduced, and the yield is lowered.

In this regard, the inventors have conceived a method of using CMP instead of dry etching. Specifically, the inventors of the present invention thought that after forming a high-carbon carbon-based material on a substrate and an insulating material including a substrate and an insulating material (for example, yttrium oxide) having a predetermined pattern and formed on the substrate, The surface layer portion of the carbon-based material is removed by CMP, and the polishing of the carbon-based material is stopped when the insulating material is exposed.

The composition of the abrasive for CMP generally differs depending on the object to be polished (the substance to be removed and the substance remaining without being removed). An abrasive for CMP of a high carbon content carbon-based material is known only (for example, refer to Patent Document 3). For other applications (for example, for glass polishing, shallow trench isolation (STI) formation, or metal material polishing), it is difficult to remove a high carbon content carbon material by polishing.

Most of the conventional CMP abrasives are abrasives for polishing relatively hard materials such as inorganic insulating materials and metal materials, and are ground by mechanical action of abrasive grains contained in the abrasive for CMP. However, a high carbon carbon material contains an organic compound as a main component and is a softer material than an inorganic insulating material and a metal material. Therefore, when a high carbon content carbon material is polished using the conventional CMP abrasive, the mechanical action of the abrasive grains is dispersed. Therefore, grinding is hardly performed, or grinding is performed while facing a high-carbon carbon material. Therefore, it is difficult to planarize the surface after polishing.

Further, in the process of stopping the polishing of the carbon-based material when the insulating material is exposed, the design of the abrasive is difficult. The reason for this is that the carbon-based material must be removed without removing the insulating material. For example, if the mechanical action of the abrasive grains is increased by increasing the particle size of the abrasive grains in order to increase the polishing rate of the carbon-based material, not only the carbon-based material but also the insulating material can be removed.

The present invention has been made to solve the above problems, and an object thereof is to provide a polishing method capable of removing a high carbon content carbon material at a good polishing rate and selectively removing a high carbon amount carbon material with respect to an insulating material. Agent, storage solution for abrasives and grinding method. [Means for solving the problem]

The present inventors conducted intensive studies and found that high-carbon carbon can be obtained at a good polishing rate by using abrasive grains containing cerium oxide and having a positive charge in the abrasive, and an allylamine-based polymer. The material is removed and the high carbon carbon material can be selectively removed relative to the insulating material.

That is, the polishing agent of the present invention is an abrasive for chemically mechanically polishing a substrate containing a carbon-based material and an insulating material to remove at least a part of the carbon-based material by X-ray photoelectron spectroscopy. The measured carbon amount is from 60 atm% to 95 atm%, and the abrasive contains the cerium oxide-containing abrasive particles, the allylamine-based polymer and water, and the mass ratio of the content of the allylamine-based polymer to the content of the abrasive particles. From 0.002 to 0.400, the abrasive particles have a positive charge in the abrasive.

According to the abrasive of the present invention, a high carbon amount carbon material can be removed at a good polishing rate, and a high carbon amount carbon material can be selectively removed with respect to the insulating material.

The allylamine-based polymer preferably contains a structural unit represented by the following formula (I), a structural unit represented by the following formula (II), and a structure represented by the following formula (III). At least one of a unit, a structural unit represented by the following general formula (IV), and a structural unit represented by the following general formula (V). In this case, the allylamine-based polymer reduces the contact frequency of the insulating material with the abrasive grains, thereby further suppressing the polishing rate of the insulating material, so that the carbonaceous material having a high carbon content can be further selectively removed from the insulating material. [Chemical 1] [wherein, R ¹¹ , R ¹² , R ² and R ³ each independently represent a hydrogen atom, an alkyl group or an aralkyl group, and the amine group and the nitrogen-containing ring may each independently form an acid addition salt] [Chemical 2] Wherein R ⁴¹ and R ⁴² each independently represent an alkyl group or an aralkyl group, R ⁵¹ and R ⁵² each independently represent an alkyl group or an aralkyl group, and D ^- represents a monovalent anion]

The cerium oxide is preferably colloidal cerium oxide. In this case, the polishing damage can be reduced while ensuring a high polishing rate of the carbon-based material (refer to damage occurring on the surface to be polished after polishing. The same applies hereinafter).

The abrasive of the present invention may further contain an organic solvent. In this case, the wettability of the polishing agent to the high carbon content carbon material can be increased to further increase the polishing rate of the carbon material.

The pH of the abrasive of the present invention is preferably from 1.0 to 8.0. In this case, the polishing rate of the carbon-based material can be further increased, and the dissolution of the abrasive grains can be suppressed.

The abrasive of the present invention may further contain an acid component. In this case, the liquid stability of the abrasive can be improved and the surface to be polished can be flattened more satisfactorily.

In the polishing agent of the present invention, the polishing rate ratio of the carbon-based material to the insulating material is preferably 50 or more.

The abrasive of the present invention can also be stored in the form of a multi-liquid abrasive comprising a first liquid containing abrasive grains and water, and a second liquid containing an allylamine-based polymer and water. In this case, the liquid stability of the abrasive can be improved.

The polishing solution for an abrasive of the present invention is used for obtaining a polishing liquid for the abrasive, and the polishing agent is obtained by diluting with water. In this case, the cost, space, and the like necessary for transportation, storage, and the like of the abrasive can be reduced.

A first embodiment of the polishing method of the present invention includes: a step of preparing a substrate containing a carbon-based material and an insulating material having a carbon amount of 60 atm% to 95 atm% as measured by X-ray photoelectron spectroscopy; and using the polishing A polishing step in which the substrate is subjected to chemical mechanical polishing to remove at least a portion of the carbon-based material. A second embodiment of the polishing method of the present invention includes a step of preparing a substrate containing a carbon-based material and an insulating material having a carbon amount of 60 atm% to 95 atm% as measured by X-ray photoelectron spectroscopy; a step of obtaining an abrasive by diluting the polishing agent with a stock solution; and a polishing step of chemically mechanically polishing the substrate with the abrasive to remove at least a portion of the carbon-based material. According to these polishing methods, a high carbon content carbon material can be removed at a good polishing rate, and a high carbon content carbon material can be selectively removed with respect to the insulating material.

In the polishing method of the present invention, the polishing may be stopped when the insulating material is exposed in the polishing step. [Effects of the Invention]

According to the present invention, a high-carbon carbon material can be removed at a good polishing rate, and a high-carbon carbon material can be selectively (preferred) removed with respect to the insulating material.

Further, according to the present invention, there is provided an application of an abrasive or a polishing liquid for polishing, wherein the polishing is performed by chemical mechanical polishing of a substrate containing a carbon-based material and an insulating material to remove at least a portion of the carbon-based material. . According to the present invention, it is possible to provide an application of a polishing solution for abrasive or abrasive in double patterning. The polishing agent of the present invention can provide an abrasive or abrasive storage liquid for polishing in which at least a part of a carbon-based material (a high-carbon carbon-based material) of a wiring board is removed.

<Definition> The term "steps" in this manual refers not only to independent steps, but also to steps that cannot be clearly distinguished from other steps but that achieve the intended effect of the steps.

In the present specification, "~" means a range including the numerical values described before and after the minimum value and the maximum value.

In the case where the content of each component in the composition is a plurality of substances corresponding to the respective components in the composition, unless otherwise specified, the total amount of the plurality of substances present in the composition is referred to.

In the present specification, the term "Polishing Rate" means the speed at which the material to be polished is removed per unit time (Removal Rate = Removal Rate).

In the present specification, the phrase "selectively removing the material A with respect to the material B" means that the material A is preferentially removed compared to the material B. More specifically, it means that in the matrix in which the material A and the material B are mixed, the material A is preferentially removed compared to the material B.

In the present specification, the term "diluting the slurry for the polishing agent to X times" means that the amount of the polishing agent is the storage liquid for the polishing agent when the polishing agent is obtained by adding water or the like to the polishing liquid for the polishing agent. X-like dilution of quality. For example, when an abrasive is obtained by adding water of the same quality to the mass of the polishing liquid for the polishing agent, it is defined as diluting the polishing agent storage solution by a factor of two.

Hereinafter, embodiments of the present invention will be described.

<Abrasion Agent> The polishing agent of the present embodiment is a composition that comes into contact with the surface to be polished during polishing, and is, for example, an abrasive for CMP.

The polishing agent of the present embodiment is for performing CMP on a substrate containing a carbon-based material (High Carbon Material) and an insulating material (excluding the carbon-based material) to remove at least a part of the carbon-based material. The abrasive, wherein the amount of carbon of the carbon-based material measured by X-ray photoelectron spectroscopy (XPS) is 60 atm% to 95 atm%. The polishing agent of the present embodiment contains cerium oxide-containing abrasive grains, an allylamine-based polymer, and water. In the present embodiment, the mass ratio of the content of the allylamine-based polymer to the content of the abrasive grains (the content of the allylamine-based polymer/the content of the abrasive grains) is 0.002 to 0.400, and the abrasive grains have a positive charge in the abrasive. (The following is the surface charge unless otherwise specified).

When the carbon content of the carbon-based material is 60 atm% or more, the carbon-based material (for example, a carbon-based material film formed of a carbon-based material) has an appropriate hardness, so that mechanical dispersion of the abrasive grains can be suppressed. Thereby, the fall of the polishing rate of a carbon-type material can be suppressed. When the carbon content of the carbon-based material is 95 atm% or less, the carbon-based material (for example, the carbon-based material film) is suppressed from having an excessively high hardness, so that the mechanical action of the abrasive grains is sufficiently exhibited. Thereby, a sufficient polishing rate of the carbon-based material can be obtained.

From the above viewpoints, in the polishing agent of the present embodiment, the amount of carbon of the carbon-based material is from 60 atm% to 95 atm%, and the carbon-based material can be removed at a high polishing rate. The carbon amount of the carbon-based material is preferably 65 atm% or more, more preferably 70 atm% or more, and further preferably 75 atm% or more from the viewpoint of effectively obtaining the effect of removing the carbon-based material at a high polishing rate. , especially good for 80 atm% or more, extremely good for 85 atm% or more, very good for 87 atm% or more. The carbon amount of the carbon-based material is preferably 95 atm% or less, more preferably 93 atm% or less, and further preferably 91 atm% or less from the viewpoint of effectively obtaining the effect of removing the carbon-based material at a high polishing rate. .

The carbon amount of the carbon-based material is measured by X-ray photoelectron spectroscopy. The analysis of X-ray photoelectron spectroscopy can be carried out, for example, using "PHI-5000-Versa Probe II" manufactured by Ulvac-Phi Co., Ltd. In this case, the X-ray source can use monochromatic Al-Kα rays (1486.6 eV). Regarding the measurement conditions, for example, the detection angle is 45 degrees, the analysis area is 200 μmf, the voltage is 15 kV, and the output is 50 W. The amount of carbon was determined by measuring the spectrum of C1s (280 eV to 300 eV), and the peak top of the obtained C1s was set to 284.3 eV to perform charging correction, and the peak area of C1s was obtained.

The carbon-based material is not particularly limited as long as it satisfies the carbon amount. Examples of the carbon-based material include a phenol resin, an epoxy resin, an acrylic resin, a methacrylic resin, a novolak resin, an unsaturated polyester resin, a polyester resin (excluding an unsaturated polyester resin), and a polyimide resin. A resin material such as a polyamidoximine resin, a polybenzoxazole (PBO), a polyallyl ether resin, a heterocyclic-containing resin (excluding the above-exemplified resin), an anthrone-containing resin, or the like. The method for forming the carbon-based material is not particularly limited, and examples thereof include a vapor deposition method and a spin coating method. The shape of the carbon-based material is not particularly limited, and is, for example, a film (carbon-based material film).

The insulating material is not particularly limited, and a known insulating material can be widely used. Specifically, a lanthanum insulating material or the like can be cited. Examples of the lanthanoid insulating material include cerium oxide, fluorosilicate glass, organic silicate glass, cerium oxynitride, and cerium oxide-based materials such as hydrogenated sesquioxanes; cerium carbide; cerium nitride. The insulating material may also be doped with elements such as phosphorus and boron.

In the case where the carbon-based material is removed by CMP, it is considered that it is easy to increase the polishing rate of the carbon-based material by using abrasive grains having a positive charge in the polishing agent. Further, it is considered that the abrasive grains containing cerium oxide have higher affinity with the carbon-based material than the other types of abrasive grains, and therefore the contact frequency between the abrasive grains and the carbon-based material increases. Therefore, it is considered that the polishing rate of the carbon-based material is improved by using abrasive grains containing cerium oxide and having a positive charge in the abrasive.

On the other hand, the abrasive grains containing cerium oxide have high affinity for the insulating material. Further, since the surface of the insulating material has a negative charge in a wide pH range, the abrasive grains having a positive charge in the abrasive are electrostatically adsorbed to the insulating material. Therefore, when abrasive grains containing cerium oxide and having a positive charge in the polishing agent are used, there is a tendency that not only the carbon-based material but also the polishing rate of the insulating material is increased.

However, the present inventors have found that the polishing agent of the present embodiment contains an allylamine-based polymer, whereby the polishing rate of the insulating material can be greatly reduced, and the polishing rate of the carbon-based material is only slightly lowered or substantially unchanged.

The effect can be considered to be obtained for the following reasons. That is, it is considered that the allylamine-based polymer is preferentially adsorbed on the surface of the insulating material than the carbon-based material. Therefore, the protective film produced by the allylamine-based polymer is preferentially formed on the surface of the insulating material than the carbon-based material. Thereby, it can be considered that the contact frequency of the abrasive grains with the insulating material is reduced, so that the polishing rate of the insulating material is lowered.

According to the above, according to the polishing agent of the present embodiment, the carbon-based material can be removed at a good polishing rate, and the carbon-based material can be selectively removed with respect to the insulating material. In other words, according to the polishing agent of the present embodiment, a high polishing rate of the carbon-based material can be obtained, and a high polishing selection ratio (a polishing rate of the carbon-based material/a polishing rate of the insulating material) of the carbon-based material with respect to the insulating material can be obtained.

Hereinafter, the components and the like contained in the polishing agent of the present embodiment will be described in detail.

(Abrasive Grain) The polishing agent of the present embodiment contains abrasive grains containing cerium oxide. The abrasive particles have a positive charge in the abrasive. It is considered that the abrasive grains have higher affinity for the carbonaceous material of cerium oxide than other types of abrasive grains, and thus the contact frequency between the abrasive grains and the carbon-based material increases.

Whether or not the abrasive particles have a positive charge in the abrasive can be judged by measuring the dynamic potential of the abrasive grains in the abrasive. When the value of the dynamic potential of the abrasive grains in the abrasive is measured and the value exceeds 0 mV, it can be judged that the abrasive grains have a positive charge.

The kinematic potential can be measured, for example, by the trade name: DELSA NANO C manufactured by Beckman Coulter. The kinematic potential (ζ[mV]) can be measured in the following order. First, the scattering intensity of the sample measured in the potentiodynamic measuring device is 1.0 × 10 ⁴ cps to 5.0 × 10 ⁴ cps (here, "cps" means "counts per second", that is, counting every second, and is a particle count. The method of obtaining the sample by diluting the abrasive with pure water. Then, the sample was placed in a potentiodynamic measurement cell to measure the kinematic potential. In order to adjust the scattering intensity to the above range, for example, the abrasive is diluted so that the abrasive grains are 1.7% by mass to 1.8% by mass.

The method of adjusting the abrasive grains to have a positive charge in the polishing agent includes a method of controlling the method of producing the abrasive grains, a method of adjusting the pH of the polishing agent, a method of surface-treating the abrasive grains, and the like. A case where cerium oxide is used as the abrasive grains will be described as an example. Conventional cerium oxide has a negative charge in solution, but has a tendency to have a positive charge by lowering the pH. Further, the cerium oxide may be surface-treated with a coupling agent having a cationic group.

The dynamic potential is preferably 10 mV or more, more preferably 15 mV or more, and more preferably 18 mV or more from the viewpoint of obtaining a more excellent polishing rate and storage stability. The upper limit of the kinematic potential is not particularly limited and is, for example, 100 mV.

Examples of the cerium oxide include colloidal cerium oxide, gas phase cerium oxide, and the like. Among them, from the viewpoints of higher polishing rate of the carbon-based material, less viewpoint of polishing damage, and easy selection of particle diameter, it is preferred. It is a colloidal cerium oxide.

The abrasive particles may contain other than cerium oxide. For example, the abrasive grains may contain particles of alumina, cerium oxide, zirconium oxide, cerium hydroxide, or resin. Further, the abrasive grains may contain composite particles in which particles other than the cerium oxide particles are adhered to the surface of the cerium oxide particles, and may also contain a composite of cerium oxide particles adhered to the surface of particles other than the cerium oxide particles. particle. The abrasive grains may be used alone or in combination of two or more.

In view of the fact that the polishing rate of the carbon-based material is higher, the content of cerium oxide is preferably more than 50% by mass, more preferably 60% by mass or more, and still more preferably 70% based on the total mass of the abrasive particles. The mass% or more is more preferably 80% by mass or more, and particularly preferably 90% by mass or more, and particularly preferably 95% by mass or more.

From the viewpoint of obtaining a sufficient mechanical polishing force and a higher polishing rate of the carbon-based material, the content of cerium oxide is preferably 0.005 parts by mass or more, and more preferably 0.05% by mass based on 100 parts by mass of the polishing agent. The amount is preferably 0.10 parts by mass or more, and more preferably 0.15 parts by mass or more. It is easy to avoid the viewpoint of the increase in the viscosity of the polishing agent, the viewpoint of easily avoiding the aggregation of the abrasive grains, the viewpoint of easily reducing the polishing damage, the viewpoint of easy handling of the polishing agent, and the like, and the content of cerium oxide with respect to 100 parts by mass of the polishing agent. It is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, further preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less.

The content of the abrasive grains is preferably 0.01 with respect to 100 parts by mass of the abrasive, from the viewpoint of easily obtaining a polishing rate of the carbon material which is sufficiently meaningful as compared with the polishing rate of the carbon-based material in the case where the abrasive particles are not contained. The amount by mass or more is more preferably 0.05 parts by mass or more, and further preferably 0.1 parts by mass or more. The content of the abrasive grains is preferably 10 parts by mass or less, more preferably 6 parts by mass or less, based on 100 parts by mass of the polishing agent, from the viewpoint of improving the polishing rate of the carbon-based material and the dispersion stability of the abrasive particles. Further, it is preferably 4 parts by mass or less, and particularly preferably 3 parts by mass or less.

The average particle diameter of the abrasive grains is preferably 10 nm or more, more preferably 30 nm or more, and more preferably 40 nm or more from the viewpoint that it is easy to obtain sufficient mechanical polishing force and the polishing rate of the carbon-based material is higher. . The average particle diameter of the abrasive grains is preferably 200 nm or less, more preferably 120 nm or less, further preferably 100 nm or less, and particularly preferably 90 nm or less from the viewpoint of good dispersion stability of the abrasive grains.

The average particle diameter of the abrasive particles can be measured by a photon correlation method. Specifically, for example, the average name of a device manufactured by Malvern Instruments, Zetasizer 3000HS, and a device name: N5 manufactured by Beckman Coulter Co., Ltd. can be used to measure the average. Particle size. The measurement method using N5 is as follows. Specifically, for example, an aqueous dispersion in which the content of the abrasive grains is adjusted to 0.2% by mass is prepared, and about 4 mL (L means "liter". The same below) is placed in a pool of 1 cm square. , set the pool inside the device. The refractive index of the dispersion medium was set to 1.33, the viscosity was set to 0.887 mPa·s, and the measurement was carried out at 25 ° C, and the value thus obtained was used as the average particle diameter of the abrasive grains.

(Polymer) The polishing agent of the present embodiment contains an allylamine-based polymer. The "allylamine-based polymer" in the present specification is a polymer defined as a structural unit obtained by polymerizing a monomer containing an allylamine-based compound. The "allylamine-based compound" in the present specification is defined as a compound having an allyl group and an amine group. The allylamine-based polymer may contain a structural unit obtained by polymerizing only an allylamine-based compound, or may contain a structural unit obtained by copolymerizing an allylamine-based compound and a compound other than the allylamine-based compound. The allylamine-based compound may be used alone or in combination of two or more.

The weight average molecular weight of the allylamine-based polymer is preferably 500 or more, more preferably 800 or more, and still more preferably 1,000 or more from the viewpoint of easily suppressing the polishing rate of the insulating material. The weight average molecular weight of the allylamine-based polymer is preferably 300,000 or less, more preferably 200,000 or less, and still more preferably 150,000 or less, from the viewpoint of suppressing the viscosity from being too high and obtaining good storage stability.

The weight average molecular weight (Mw) of the allylamine-based polymer can be measured, for example, using Gel Permeation Chromatography (GPC) under the following conditions.

[Condition] Sample: 20 μL Standard polyethylene glycol: Standard polyethylene glycol manufactured by Polymer Laboratories (molecular weight: 106, 194, 440, 600, 1470, 4100, 7100, 10300, 12600) 23000) Detector: manufactured by Showa Denko Co., Ltd., refractive index (Refractive Index, RI) - monitor, trade name "Syodex-RI SE-61" Pump: manufactured by Hitachi, Ltd., trade name "L-6000 Pipe column: manufactured by Showa Denko Co., Ltd., using the product name "GS-220HQ" and "GS-620HQ" in sequence, using a solution: 0.4 mol/L sodium chloride aqueous solution. Temperature: 30 ° C Flow rate: 1.00 mL/min measurement time: 45 min

The content of the allylamine-based polymer is preferably 0.001 part by mass or more, more preferably 0.003 part by mass or more, and still more preferably 0.004 part by mass, based on 100 parts by mass of the polishing agent, in terms of the polishing rate of the insulating material. The above is particularly preferably 0.005 parts by mass or more. The content of the allylamine-based polymer is preferably 0.400 based on 100 parts by mass of the abrasive, from the viewpoint of suppressing a decrease in the polishing rate of the carbon-based material and easily maintaining the polishing rate of the carbon-based material with respect to the insulating material. The amount by mass or less is more preferably 0.300 parts by mass or less, further preferably 0.200 parts by mass or less, and particularly preferably 0.100 parts by mass or less.

The mass ratio of the content of the allylamine-based polymer to the content of the abrasive grains is 0.002 or more from the viewpoint of selectively removing the carbon-based material with respect to the insulating material. The quality is preferably 0.003 or more, and more preferably 0.005 or more from the viewpoint of easily and selectively removing the carbon-based material with respect to the insulating material.

The mass ratio of the content of the allylamine-based polymer to the content of the abrasive grains is 0.400 or less from the viewpoint of removing the carbon-based material at a good polishing rate. From the viewpoint of easily removing the carbon-based material at a good polishing rate, the mass is preferably 0.300 or less, more preferably 0.200 or less.

The allylamine-based polymer preferably contains a structural unit selected from the following general formula (I) in the molecule of the polymer from the viewpoint of further selectively removing the carbon-based material with respect to the insulating material. a structural unit represented by the following formula (II), a structural unit represented by the following formula (III), a structural unit represented by the following formula (IV), and a formula represented by the following formula (V) At least one of the group consisting of structural units. [Chemical 3] Wherein R ¹¹ , R ¹² , R ² and R ³ each independently represent a hydrogen atom, an alkyl group or an aralkyl group, and the alkyl group and the aralkyl group may also have a hydroxyl group, and the amine group and the nitrogen-containing ring may also be respectively independently form acid addition salts, R ¹¹ and R ¹² may be the same or different from each other] [Chemical Formula 4] Wherein R ⁴¹ and R ⁴² each independently represent an alkyl group or an aralkyl group, and the alkyl group and the aralkyl group may have a hydroxyl group, and R ⁵¹ and R ⁵² each independently represent an alkyl group or an aralkyl group, and D ^- Represents a monovalent anion. R ⁴¹ and R ⁴² may be the same or different from each other. R ⁵¹ and R ⁵² may be the same or different from each other]

The allylamine-based polymer may contain one type of the structural unit (I) to the structural unit (V), and may contain two or more types. The total number of the structural units (I) to (V) in the molecule is preferably 5 or more, more preferably 7 or more, and still more preferably 10 or more from the viewpoint of easily suppressing the polishing rate of the insulating material. Here, the total number of the structural units (I) to (V) in the molecule is the average value of the allylamine-based polymer contained in the polishing agent.

The alkyl group of R ¹¹ , R ¹² , R ² and R ³ in the formula (I), the formula (II) and the formula (III) may be any of a linear chain, a branched chain and a cyclic chain. The carbon number of the alkyl group is preferably 1 or more from the viewpoint of easily suppressing the polishing rate of the insulating material. The carbon number of the alkyl group is preferably 10 or less, more preferably 7 or less, still more preferably 5 or less, and particularly preferably 4 or less from the viewpoint of easily suppressing the polishing rate of the insulating material.

The alkyl group of R ¹¹ , R ¹² , R ² and R ³ may also have a hydroxyl group. The alkyl group of R ¹¹ , R ¹² , R ² and R ³ may, for example, be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclohexyl or the like. a hydroxyl group adduct of a group (3-hydroxypropyl group, etc.).

The aralkyl group means a group in which one hydrogen atom of the alkyl group is substituted with an aryl group. Here, in the general formula (I), the general formula (II) and the general formula (III), the alkyl group constituting the aralkyl group of R ¹¹ , R ¹² , R ² and R ³ may be linear or branched. Any of the rings. The aralkyl group preferably has 7 to 10 carbon atoms from the viewpoint of easily suppressing the polishing rate of the insulating material.

The aralkyl group of R ¹¹ , R ¹² , R ² and R ³ may also have a hydroxyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a phenylbutyl group, a phenylhexyl group, a hydroxyl group adduct of these groups, and the like.

The amine group in the formula (I) and the nitrogen-containing ring in the formula (II) and the formula (III) may also form an acid addition salt. The acid addition salt may, for example, be a hydrochloride, a hydrobromide, an acetate, a sulfate, a nitrate, a sulfite, a phosphate, a guanamine sulfate or a methanesulfonate. Among these acid addition salts, from the viewpoint of obtaining a higher polishing rate ratio of the carbon-based material to the insulating material, a hydrochloride, an acetate, and a guanamine sulfate are preferable.

Among these, R ¹¹ , R ¹² , R ² and R ^{3 are} preferably a hydrogen atom, a methyl group and an ethyl group from the viewpoint of good wettability of an insulating material (for example, cerium oxide).

In the allylamine-based polymer containing a structural unit represented by the general formula (I), the general formula (II) or the general formula (III), a viewpoint of obtaining a higher polishing selectivity ratio of the carbon-based material relative to the insulating material can be obtained. In general, an allylamine polymer and a diallylamine polymer are preferred. From the same viewpoint, the structural unit containing an acid addition salt is preferably diallylamine hydrochloride, methyl diallylamine hydrochloride, ethyl diallylamine hydrochloride, methyldiallylamine acetate. And methyldiallylamine amine sulfate.

The alkyl group of R ⁴¹ , R ⁴² , R ⁵¹ and R ⁵² in the formula (IV) and the formula (V) may be any of a linear chain, a branched chain and a cyclic group. The alkyl group of R ⁴¹ and R ⁴² preferably has 1 or more carbon atoms from the viewpoint of easily suppressing the polishing rate of the insulating material. The carbon number of the alkyl group of R ⁴¹ and R ⁴² is preferably 10 or less, more preferably 7 or less, and still more preferably 4 or less from the viewpoint of easily suppressing the polishing rate of the insulating material. The alkyl group of R ⁵¹ and R ⁵² preferably has 1 or more carbon atoms from the viewpoint of easily suppressing the polishing rate of the insulating material. The carbon number of the alkyl group of R ⁵¹ and R ⁵² is preferably 10 or less, more preferably 7 or less, and still more preferably 4 or less from the viewpoint of easily suppressing the polishing rate of the insulating material.

The alkyl group of R ⁴¹ and R ⁴² may also have a hydroxyl group. The alkyl group of R ⁴¹ and R ⁴² may, for example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group or a cyclohexyl group, or a hydroxyl group adduct of the groups. (3-hydroxypropyl group, etc.) and the like.

The alkyl group of R ⁵¹ and R ⁵² may, for example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group or a cyclohexyl group.

The alkyl group constituting the aralkyl group of R ⁴¹ , R ⁴² , R ⁵¹ and R ⁵² in the general formula (IV) and the general formula (V) may be linear, branched or cyclic. The aralkyl group preferably has 7 to 10 carbon atoms from the viewpoint of easily suppressing the polishing rate of the insulating material.

The aralkyl group of R ⁴¹ and R ⁴² may also have a hydroxyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a phenylbutyl group, a hydroxyl group adduct of these groups, and the like.

Aralkyl of R ⁵¹ and R ⁵² include: benzyl, phenethyl, phenylpropyl, phenylbutyl and the like.

Among these, R ⁴¹ , R ⁴² , R ⁵¹ and R ^{52 are} preferably a methyl group, a benzyl group and a phenethyl group from the viewpoint of good wettability of an insulating material (for example, cerium oxide).

Formula (IV) and formula (V) in the D ^{- include: Cl -, Br -, I} - halogen ions; methyl sulfate ion, ethyl sulfate ion, sulfate ion, alkyl dimethyl Base sulfate ions and the like.

The partial structure represented by the following general formula (IVa) in the general formula (IV) and the partial structure represented by the following general formula (Va) in the general formula (V) include an N,N-dialkyl group. An ammonium salt, an N-alkyl-N-benzyl ammonium salt or the like. The N,N-dialkylammonium salt may be exemplified by halogenated-N,N-dimethylammonium, halogenated-N,N-diethylammonium, halogenated-N,N-dipropylammonium, halogenated-N,N. -N,N-dialkylammonium such as dibutylammonium halide; N,N-dioxane such as N,N-dimethylammonium methyl sulfate, N,N-methylethylammonium ethyl sulfate Alkyl ammonium alkyl sulfate and the like. The N-alkyl-N-benzylammonium salt may, for example, be a halogenated-N-methyl-N-benzylammonium halide or a halogenated-N-ethyl-N-benzylammonium halide or the like. Alkyl ammonium and the like. The halide of the partial structure may, for example, be a chloride, a bromide, an iodide or the like. Among the structural units having such partial structures, from the viewpoint of obtaining a higher polishing rate ratio of the carbon-based material to the insulating material, chlorinated-N,N-dimethylammonium and N,N are preferred. -methylethylammonium ethyl sulfate. [Chemical 5]

The allylamine-based polymer may have a structure obtained by copolymerizing an allylamine-based compound with a compound other than the allylamine-based compound. The allylamine-based polymer may have, for example, a group comprising a structural unit represented by the formula (I), a structural unit represented by the formula (II), and a structural unit represented by the formula (III). A structure obtained by copolymerizing a monomer of at least one structural unit with a monomer other than the allylamine-based compound.

The allylamine-based polymer may further contain a structural unit represented by the following formula (VI), a structural unit represented by the following formula (VII), a structural unit represented by the following formula (VIII), and At least one of the groups consisting of the structural units represented by the general formula (IX). For example, the allylamine-based polymer may further contain a structural unit represented by the formula (I), a structural unit represented by the formula (II), a structural unit represented by the formula (III), and a formula (IV). At least one structural unit composed of the structural unit represented by the structural unit represented by the general formula (V) and the structural unit represented by the following general formula (VI), and the following formula (VII) At least one structural unit of the structural unit represented by the structural unit represented by the following formula (VIII) and the structural unit represented by the following general formula (IX).

[Chemical 6] [In the formula (VI), Q represents an alkylene group, R ⁶ represents a hydrogen atom or an alkyl group, and n represents an average addition molar number of 0 to 30]

[Chemistry 7]

[化8] [In the formula (VIII), R ⁸ represents a hydrogen atom or an alkyl group, and Y ⁺ represents a cation]

[Chemistry 9] [In the formula (IX), R ⁹ represents a hydrogen atom or an alkyl group]

When n is 0, a monomer which provides a structural unit represented by the general formula (VI) is exemplified by allyl alcohol. When n is from 1 to 30, a monomer which provides a structural unit represented by the formula (VI): (poly)oxyalkylene monoallyl ether, (poly)oxyalkylene monoallyl monomethyl Ether, etc. In this case, from the viewpoint of easily suppressing the polishing rate of the insulating material, the alkylene group represented by Q is preferably a linear or branched alkyl group having 2 to 3 carbon atoms, more preferably stretched. Ethyl, trimethylene and propyl. The alkylene group may be introduced into a single one or may be introduced in combination of two or more. From the viewpoint of easily suppressing the polishing rate of the insulating material, R ^{6 is} preferably a hydrogen atom or a methyl group.

The allylamine-based polymer containing the structural unit represented by the general formula (VI) is preferably a diallylmethylamine hydrochloride from the viewpoint that the polishing rate ratio of the carbon-based material to the insulating material becomes higher. Salt allyl alcohol copolymer.

Examples of the monomer which provides the structural unit represented by the formula (VII) include sulfur dioxide and the like. From the viewpoint of obtaining a higher polishing rate ratio of the carbon-based material to the insulating material, the allylamine-based polymer containing the structural unit represented by the formula (VII) is preferably a diallylamine hydrochloride sulfur dioxide copolymer.

From the viewpoint of easily suppressing the polishing rate of the insulating material, R ⁸ in the formula (VIII) is preferably a hydrogen atom and a methyl group, and more preferably a hydrogen atom. Examples of Y ⁺ include alkali metal ions such as sodium ions and potassium ions; hydrogen ions; ammonium ions and the like.

Examples of the monomer which provides the structural unit represented by the formula (VIII) include maleic acid, fumaric acid, citraconic acid, itaconic acid, mesaconic acid, 2-allylmalonic acid, and the like. From the viewpoint of easily lowering the polishing rate of the insulating material and the dispersibility of the allylamine-based polymer in the polishing agent, maleic acid is preferred.

From the viewpoint of obtaining a higher polishing rate ratio of the carbon-based material to the insulating material, the allylamine-based polymer containing the structural unit represented by the general formula (VIII) is preferably a diallylamine hydrochloride Malay. Acid copolymer and diallylamine sulfonate sulfate maleic acid copolymer.

From the viewpoint of easily suppressing the polishing rate of the insulating material, R ⁹ in the formula (IX) is preferably a hydrogen atom and a methyl group, and more preferably a hydrogen atom. Examples of the monomer which provides the structural unit represented by the formula (IX) include acrylamide and the like.

From the viewpoint of obtaining a higher polishing rate ratio of the carbon-based material to the insulating material, the allylamine-based polymer containing the structural unit represented by the general formula (IX) is preferably a diallylmethyl chloride. Ammonium acrylamide copolymer and diallyldimethylammonium acrylamide copolymer.

From the viewpoint of obtaining a higher polishing rate ratio of the carbon-based material to the insulating material, the allylamine-based polymer is preferably a methyldienylamine amine sulfate polymer, an allylamine polymer, or a chlorination Allyldimethylammonium acrylamide copolymer and diallylamine hydrochloride sulfur dioxide copolymer.

(Water) The abrasive of the present embodiment contains water. Water can be used as a dispersion medium or solvent for other ingredients. The water is preferably as free of impurities as possible to prevent the action of other components. Specifically, the water is preferably pure water, ultrapure water, and distilled water which are removed by an ion exchange resin to remove foreign matter and then pass through a filter to remove foreign matter.

(Additive) The polishing agent of the present embodiment may further contain abrasive grains, allylamine-based polymers, and water in order to improve the dispersibility of the abrasive grains in the polishing agent, to improve the chemical stability of the polishing agent, and to increase the polishing rate. ingredient. Examples of such a component include additives such as an organic solvent, an acid component, an anticorrosive agent, and an antifoaming agent. The content of the additive in the abrasive can be arbitrarily determined within a range that does not impair the properties of the abrasive.

[Organic solvent] The polishing agent of the present embodiment may contain an organic solvent. By the organic solvent contained in the abrasive, the polishing rate ratio can be adjusted and the wettability of the abrasive can be improved. The organic solvent is not particularly limited, and is preferably a solvent which is liquid at 20 °C. From the viewpoint of making the polishing agent highly concentrated, the solubility of the organic solvent in 100 g of water (20 ° C) is preferably 30 g or more, more preferably 50 g or more, and still more preferably 100 g or more. The organic solvent may be used alone or in combination of two or more.

Examples of the organic solvent include carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate; lactones such as butyrolactone and propiolactone; a glycol such as alcohol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol or tripropylene glycol; 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, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether, tripropylene glycol monoethyl ether, ethylene Alcohol 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, Glycol monoethers such as diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether, triethylene glycol monobutyl ether, tripropylene glycol monobutyl ether; 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, C Alcohol 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 A derivative of a glycol such as a glycol diether such as an ether or tripropylene glycol dibutyl ether. In view of the fact that the surface tension is low, at least one selected from the group consisting of diols and diol derivatives is preferable, and from the viewpoint of lower surface tension, it is more preferably two. Alcohol monoethers.

When the polishing agent of the present embodiment contains an organic solvent, the content of the organic solvent is preferably 0.100 parts by mass or more based on 100 parts by mass of the polishing agent, from the viewpoint of suppressing the decrease in the wettability of the carbon-based material. More preferably, it is 0.500 part by mass or more, and further preferably 1.000 parts by mass or more. The content of the organic solvent is preferably 15.000 parts by mass or less, more preferably 10.000 parts by mass or less, and still more preferably 5.000 parts by mass or less based on 100 parts by mass of the polishing agent.

[Acid Component] The polishing agent of the present embodiment may contain an acid component. When the polishing agent of the present embodiment contains an acid component and the pH is controlled, the liquid stability of the polishing agent can be improved, and the surface to be polished can be flattened more satisfactorily. The acid component is preferably at least one selected from the group consisting of an organic acid and a mineral acid from the viewpoint of further improving the dispersibility, stability, and polishing rate of the aqueous dispersion. The organic acid is not particularly limited, and examples thereof include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, and 2-ethylbutyric acid. 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid , glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, and the like. The inorganic acid is not particularly limited, and examples thereof include hydrochloric acid, sulfuric acid, nitric acid, and chromic acid.

(pH of the polishing agent) The pH of the polishing agent of the present embodiment is preferably 1.0 or more, and more preferably 1.5 or more, from the viewpoint that the mechanical polishing force is easily obtained and the polishing rate of the carbon-based material is further improved. Further preferably, it is 2.0 or more, and particularly preferably 2.3 or more. The pH of the polishing agent is preferably 8.0 or less, more preferably 5.0 or less, further preferably 4.0 or less, particularly preferably 3.5 or less, and extremely preferably 3.0 or less from the viewpoint of obtaining good dispersion stability of the abrasive grains. . The pH of the polishing agent can be adjusted, for example, by the acid component or an alkali component such as ammonia, sodium hydroxide, potassium hydroxide or tetramethylammonium hydride (TMAH). The pH is defined as the pH at a liquid temperature of 25 °C.

The pH of the abrasive can be measured by a pH meter using a usual glass electrode. Specifically, for example, the product name of the company, Model (F-51), can be used. The pH of the abrasive can be obtained by using phthalate pH standard solution (4.01), neutral phosphate pH standard solution (pH 6.86), and borate pH standard solution (pH 9.18). After the pH standard was adjusted to three points by the pH meter, the electrode of the pH meter was placed in the polishing agent, and the value which was stabilized after 2 minutes or more was measured. At this time, the liquid temperature of the standard buffer and the abrasive is, for example, 25 °C.

The method of blending the polishing agent and the method of dilution are not particularly limited. For example, the components may be dispersed or dissolved by stirring by a wing agitator or by ultrasonic dispersion. The order in which the components are mixed in water is not limited.

The polishing agent of the present embodiment can be stored as a one-liquid type abrasive containing at least abrasive grains, an allylamine-based polymer, and water, and can also contain a slurry (first liquid) and an additive liquid (second liquid). Preservation in the form of a multi-liquid abrasive. In the multi-liquid abrasive, the constituent components of the polishing agent are divided into a slurry and an additive liquid in such a manner that the slurry and the additive liquid are mixed to form the polishing agent. The slurry contains, for example, at least abrasive grains and water. The addition liquid contains, for example, at least an allylamine-based polymer and water. Among the slurry and the additive liquid, additives such as an organic solvent, an acid component, an anticorrosive agent, and an antifoaming agent are preferably contained in the additive liquid. Further, the constituent components of the abrasive may be stored in three or more liquids.

For the multi-liquid abrasive, the slurry can be prepared by mixing the slurry and the additive liquid just before or during the grinding. The slurry and the additive liquid in the multi-liquid abrasive may be separately supplied to the polishing pan, and the slurry and the additive liquid may be mixed on the polishing pad, and the surface to be polished may be polished using the obtained polishing agent.

<Storage Liquid for Polishing Agent> The polishing liquid for polishing agent of the present embodiment is a storage liquid for obtaining the polishing agent, and the polishing agent can be obtained by diluting the polishing liquid with a storage liquid in water. The polishing liquid storage solution is stored in an amount smaller than the amount of water used at the time of use, and is used as the polishing agent before being diluted or diluted with water before use or at the time of use. The abrasive stock solution is different from the abrasive in that the content of water is less than the abrasive. The dilution ratio is, for example, 1.5 times or more.

<Polishing Method> Next, the polishing method of the present embodiment will be described.

In the polishing method of the present embodiment, the substrate containing the carbon-based material and the insulating material is subjected to CMP, and the carbon-based material is selectively polished with respect to the insulating material. The substrate includes, for example, an insulating material (for example, an insulating film) having a concave portion and a convex portion on the surface, and a carbon-based material formed on the insulating material along the shape of the insulating material. The polishing of the polishing method of the present embodiment may be polishing that removes at least a part of the carbon-based material of the wiring board.

The polishing method of the present embodiment may include, for example, a polishing step of CMP using a one-liquid abrasive to CMP a substrate, and removing at least a portion of the carbon-based material; and the following step may be included as a polishing step: a CMP step of CMP the substrate by mixing the slurry in the multi-liquid abrasive with the additive liquid to remove at least a portion of the carbon-based material; and the following step may be included as a grinding step: using the abrasive in water A CMP step of performing CMP on the substrate by diluting the obtained polishing agent with a stock solution to remove at least a part of the carbon-based material. In the CMP step, for example, the carbon-based material may be polished and the polishing may be stopped when the insulating material is exposed.

The polishing method of the present embodiment may include a step of preparing a matrix containing a carbon-based material having a carbon amount of 60 atm% to 95 atm% and an insulating material measured by X-ray photoelectron spectroscopy before the CMP step.

In the case of using a multi-liquid abrasive, the polishing method of the present embodiment may include an abrasive preparation step of mixing the slurry in the multi-liquid abrasive with the additive liquid to obtain an abrasive before the CMP step. In the case of using the polishing liquid for storage, the polishing method of the present embodiment may include an abrasive preparation step of obtaining an abrasive by diluting the polishing liquid with water before the CMP step.

In the CMP step, for example, the surface to be polished of the substrate is pressed against the polishing cloth (polishing pad) of the polishing pad, and an abrasive is supplied between the surface to be polished and the polishing cloth on the back surface of the substrate (opposite to the surface to be polished). In a state where a predetermined pressure is applied, the substrate is relatively moved relative to the polishing pad, thereby polishing the surface to be polished.

For the polishing apparatus, for example, a general polishing apparatus having a flat disk to which a variable-speed motor or the like is attached and to which a polishing cloth can be attached, and a holder for holding the substrate can be used. The polishing cloth is not particularly limited, and a general non-woven fabric, a foamed polyurethane, a porous fluororesin or the like can be used. The polishing conditions are not particularly limited, and the rotation speed of the flat disk is preferably a low rotation of 200 rpm (=min ^-1 ) or less in order not to cause the substrate to fly out. For example, during the polishing, the polishing cloth is continuously supplied to the polishing cloth by a pump or the like. The amount of supply is not limited, and it is preferred that the surface of the polishing cloth is always covered with the abrasive, and the product produced by the grinding is continuously discharged.

In order to perform CMP in such a manner that the surface of the polishing cloth is always in the same state, the polishing method of the present embodiment preferably includes a conditioning step of the polishing cloth before the CMP step. For example, a dresser with diamond particles is used to adjust the polishing cloth with a liquid containing at least water. The polishing method of this embodiment preferably includes a substrate cleaning step after the CMP step. It is preferred that the substrate after the completion of the polishing is sufficiently washed in the running water, and then the water droplets adhering to the substrate are slid behind by a spin dryer or the like and dried. Further, it is more preferably dried by washing by a known cleaning method as follows: a commercially available cleaning liquid is flowed on the surface of the substrate, and the brush made of the polyurethane is rotated while being pressurized at a certain pressure. The brush is pressed against the substrate to remove the deposit on the substrate.

According to the polishing agent of the present embodiment, CMP can be performed on a carbon-based material having an amount of carbon of 60 atm% to 95 atm% and an insulating material measured by X-ray photoelectron spectroscopy, and at least a part of the carbon-based material can be used. Remove. Further, the polishing agent of the present embodiment can sufficiently reduce the polishing rate of the insulating material. Therefore, polishing can be performed by performing CMP on a substrate containing a carbon-based material and an insulating material to remove at least a part of the carbon-based material, and polishing is hardly performed after a part of the insulating material is exposed. Such an abrasive can be referred to as an "abrasive capable of removing a carbon-based material and stopping polishing in a stage in which an insulating material is exposed" as a term that can be understood by those skilled in the art.

The polishing agent of the present embodiment can be used for a polishing method requiring a high polishing rate ratio of a carbon-based material to an insulating material by using the above-described advantages. Specifically, a double patterning application can be cited. The polishing method of this embodiment will be described with reference to Figs. 2(a) to 2(h).

First, a substrate including the substrate 11 and the ruthenium oxide 12 having a predetermined pattern and formed on the substrate 11 is prepared (Fig. 2(a)). The carbon-based material 13 is applied onto the substrate 11 and the ruthenium oxide 12 and cured to form (Fig. 2(b)). On the surface of the carbon-based material 13, a pattern similar to the pattern of the yttrium oxide 12 is formed. Such a carbon-based material 13 is sometimes referred to as a sacrificial film.

Then, the surface layer portion of the carbon-based material 13 is subjected to CMP until the yttrium oxide 12 is exposed, and the surface composed of the surface of the yttrium oxide 12 and the surface of the carbon-based material 13 is flattened (FIG. 2(c)). The surface of the substrate which is sufficiently planarized by the CMP process has less unevenness when the photoresist is applied, the depth of focus is not easily lowered, and the yield is not easily lowered. Further, since the yttrium oxide 12 is prevented from being polished after the yttrium oxide 12 is exposed, the surface of the substrate can be uniformly processed. Further, an antireflection film (BARC film) may be formed after the step of FIG. 2(c) and before the application of the photoresist.

Then, the photoresist 14 is uniformly applied to the surface of the cerium oxide 12 and the carbon-based material 13 (Fig. 2 (d)). Then, the mask pattern is transferred onto the photoresist 14 using an exposure device. After heat-treating the substrate after pattern transfer, development processing is performed in order to remove unnecessary portions of the photoresist 14 (Fig. 2(e)).

Then, the portion of the yttrium oxide 12 exposed between the photoresists 14 is removed by dry etching using a plasma gas or the like (Fig. 2(f)). Then, the photoresist 14 is subjected to a release treatment using a solution in which an ethanolamine or an organic solvent is combined (Fig. 2(g)). Further, the carbon-based material 13 is removed by wet etching (Fig. 2(h)). By the above operation, a pattern of a line and a gap of half the pitch of the initial pattern of the yttrium oxide 12 (Fig. 2(a)) is formed.

From the viewpoint of being suitable for double patterning applications, the polishing rate of the carbon-based material and the insulating material is preferably the following polishing rate. The polishing rate of the carbon-based material is preferably 100 nm/min or more, and more preferably 150 nm/min or more, from the viewpoint of shortening the polishing time. The polishing rate of the carbon-based material is preferably 1000 nm/min or less, and more preferably 600 nm, from the viewpoint of suppressing excessive polishing of the concave portion of the carbon-based material and further improving the flatness, and from the viewpoint of easily adjusting the polishing time. Below min, it is preferably less than 500 nm/min. The polishing rate of the insulating material is preferably 4 nm/min or less, and more preferably 3 nm/min or less, from the viewpoint of easily adjusting the polishing time.

The polishing rate of the carbon-based material with respect to the insulating material is preferably 50 or more, and more preferably 70 or more, from the viewpoint of suppressing the polishing of the insulating material and easily processing the surface of the substrate. The polishing rate ratio is, for example, a polishing speed ratio when a blanket wafer containing a carbon-based material formed on a substrate and a blanket wafer containing an insulating material formed on the substrate are polished. . Further, the polishing rate ratio can be evaluated, for example, by using the same polishing cloth, the same number of revolutions, and the same load, for a blanket wafer containing a carbon-based material that is formed flat on a substrate, and for flat-covering The blanket wafers of the insulating material formed on the substrate are separately polished. [Examples]

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited thereto.

<Preparation of Abrasive Agent> (Example 1) 0.500 parts by mass of malic acid (acid component), and 0.005 part by mass of methyldiallylamine sulfonamide sulfate polymer (Nittobo Medical Co., Ltd.) The manufactured PAS-22SA-40 had a weight average molecular weight of 17,000. The structural unit containing the formula (II), hereinafter referred to as "allylamine-based polymer 1"), was placed in a container. Further, X parts by mass of ultrapure water was injected, followed by stirring to dissolve the respective components. Then, 1.000 parts by mass of colloidal ceria 1 having an average particle diameter of 70 nm was added to obtain 100 parts by mass of an abrasive. The surface of the abrasive particles is positively charged in the abrasive. In addition, the amount of the ultrapure water blending amount of X parts by mass is calculated by calculating the amount of the abrasive to be 100 parts by mass. The kinetic potential of cerium oxide in the abrasive of Example 1 was 59.4 mV.

(Example 2) An abrasive was obtained in the same manner as in Example 1 except that 4.000 parts by mass of propylene glycol monopropyl ether was added as an organic solvent. The kinetic potential of cerium oxide in the abrasive of Example 2 was 29.7 mV.

(Example 3) 0.005 parts by mass of an allylamine polymer (PAA-01 manufactured by Nittobo Medical Co., Ltd.) having a weight average molecular weight of 1600 was used. The structural unit containing the formula (I) was used. An abrasive was obtained in the same manner as in Example 1 except that the allylamine-based polymer 2 was replaced with the allylamine-based polymer 1 as the allylamine-based polymer. The kinetic potential of cerium oxide in the abrasive of Example 3 was 18.9 mV.

(Example 4) 0.005 parts by mass of diallyldimethylammonium acrylamide copolymer (PAS-J-81 manufactured by Nittobo Medical Co., Ltd.) having a weight average molecular weight of 200,000 was used. In the same manner as in Example 1, except that the structural unit of the formula (IV) and the formula (IX) is hereinafter referred to as "allylamine-based polymer 3"), the allylamine-based polymer 1 is used as the allylamine-based polymer. An operation is performed to obtain an abrasive. The kinetic potential of cerium oxide in the abrasive of Example 4 was 35.7 mV.

(Example 5) 0.005 parts by mass of diallylamine hydrochloride sulfur dioxide copolymer (PAS-92 manufactured by Nittobo Medical Co., Ltd.) having a weight average molecular weight of 200,000 was used. The formula (II) and formula (II) were contained. An abrasive was obtained in the same manner as in Example 1 except that the structural unit of VII) (hereinafter referred to as "allylamine-based polymer 4") was used as the allylamine-based polymer instead of the allylamine-based polymer 1. The kinetic potential of cerium oxide in the abrasive of Example 5 was 27.7 mV.

(Example 6) An abrasive was obtained in the same manner as in Example 1 except that the content of the abrasive grains was changed from 1.000 parts by mass to 0.200 parts by mass. The kinetic potential of cerium oxide in the abrasive of Example 6 was 54.3 mV.

(Example 7) An abrasive was obtained in the same manner as in Example 1 except that the content of the allylamine-based polymer 1 was changed from 0.005 parts by mass to 0.050 parts by mass. The kinetic potential of cerium oxide in the abrasive of Example 7 was 55.3 mV.

(Example 8) The operation was carried out in the same manner as in Example 1 except that the content of the abrasive grains was changed from 1.000 parts by mass to 2.000 parts by mass, and the content of the allylamine-based polymer 1 was changed from 0.005 parts by mass to 0.450 parts by mass. And get the abrasive. The kinetic potential of cerium oxide in the abrasive of Example 8 was 54.8 mV.

(Comparative Example 1) An abrasive was obtained in the same manner as in Example 1 except that the allylamine-based polymer was not used. The kinetic potential of cerium oxide in the abrasive of Comparative Example 1 was 14.1 mV.

(Comparative Example 2) An abrasive was obtained in the same manner as in Example 1 except that alumina was used instead of cerium oxide as the abrasive particles. The kinetic potential of cerium oxide in the abrasive of Comparative Example 2 was 37.2 mV.

(Comparative Example 3) An abrasive was obtained in the same manner as in Example 1 except that cerium oxide (ceria) was used instead of cerium oxide as the abrasive particles. The kinetic potential of cerium oxide in the abrasive of Comparative Example 3 was 47.8 mV.

(Comparative Example 4) An abrasive was obtained in the same manner as in Example 1 except that 0.005 parts by mass of polyvinylpyrrolidone was used instead of the allylamine-based polymer 1. The kinetic potential of cerium oxide in the abrasive of Comparative Example 4 was 4.6 mV.

(Comparative Example 5) An abrasive was obtained in the same manner as in Example 1 except that 0.005 parts by mass of polyacrylamide was used instead of the allylamine-based polymer 1. The kinetic potential of cerium oxide in the abrasive of Comparative Example 5 was 3.9 mV.

(Comparative Example 6) An abrasive was obtained in the same manner as in Example 1 except that the content of the allylamine-based polymer was changed from 0.005 parts by mass to 0.450 parts by mass. The kinetic potential of cerium oxide in the abrasive of Comparative Example 6 was 50.0 mV.

(Comparative Example 7) An abrasive was obtained in the same manner as in Example 1 except that the content of the allylamine-based polymer was changed from 0.005 parts by mass to 0.001 parts by mass. The kinetic potential of cerium oxide in the abrasive of Comparative Example 7 was 39.6 mV.

(Comparative Example 8) An abrasive was obtained in the same manner as in Example 1 except that 1.000 parts by mass of a sulfonic acid-modified colloidal ceria 2 (average particle diameter: 70 nm) was used instead of the colloidal ceria 1. . The kinetic potential of cerium oxide in the abrasive of Comparative Example 8 was -0.4 mV.

<Measurement of pH of Abrasive Agent> The pH of the abrasive was evaluated under the following conditions. The results are shown in Tables 1 and 2. Measurement temperature: 25 ° C ± 5 ° C Measuring device: Product Name: Model (F-51) Determination method: using phthalate pH standard solution (4.01), neutral phosphate pH standard The liquid (pH 6.86) and the borate pH standard solution (pH 9.18) were used as the pH standard solution, and after the pH meter was calibrated at 3 points, the electrode of the pH meter was placed in the polishing agent, and the measuring device was used. The pH after stabilization for 2 minutes or more was measured.

<Evaluation of polishing characteristics> A spin-on carbon film (carbon-based material film) having a thickness of 89 atm% and having a carbon content of 89 atm% as measured by X-ray photoelectron spectroscopy (XPS) was used. The obtained substrate and a substrate obtained by forming a ruthenium dioxide film (insulating film) having a thickness of 1000 nm on a ruthenium substrate by a CVD method are used as a substrate to be polished. Each of the substrates cut into 2 cm square was fixed to a holder of a polishing device (manufactured by Nanofactor Co., Ltd., FACT-200) to which a substrate mounting adsorption pad was attached. The holder was placed on the flat plate of the polishing cloth to which the foamed polyurethane was attached, with the carbon-based material facing downward. The load was carried in such a manner that the processing load became 200 g/cm ² . The carbon-based material film and the insulating film were polished for 60 seconds while dropping the polishing agent at 10 mL/min on the flat plate while setting the flat disk rotation speed to 80 min ^-1 .

The polishing rate was calculated from the difference in film thickness obtained by measuring the film thickness before and after polishing. In the measurement of the film thickness, a film thickness measuring device RE-3000 (manufactured by Dainippon Screen Manufacturing Co., Ltd.) was used. Further, the polishing rate was calculated by dividing the polishing rate of the carbon-based material film by the polishing rate of the insulating film. The results are shown in Tables 1 and 2.

[Table 1]

[Table 2]

As shown in Table 1, in the examples, the polishing rate of the carbon-based material film was faster and the polishing rate of the insulating film was slower than that of the comparative example, so that the polishing rate of the carbon-based material film with respect to the insulating film was high.

Comparing Example 1 with Example 3, in Example 1, the polishing rate of the carbon-based material film was extremely high as compared with Example 3, and the polishing rate ratio was particularly high. The reason for this is considered to be that the volume of the allylamine-based polymer of Example 1 is larger than that of the allylamine-based polymer of Example 3, and a steric hindrance effect is generated, and the contact frequency between the abrasive grains and the insulating film is easily reduced.

Further, in the allylamine-based polymers of Examples 4 and 5, the allylamine-based compound forms a copolymer with a compound other than the allylamine-based compound. That is, the amount of the structural unit derived from the allylamine-based compound in the allylamine-based polymer is reduced as compared with the allylamine-based polymer of Example 1. From this, it is considered that the polishing rate of the carbon-based material film in Example 1 is faster than that of Example 4 and Example 5 because the amount of the structural unit derived from the allylamine-based compound is larger. Further, in Example 1, the polishing rate of the carbon-based material film which was faster than that of Example 2, Example 6, and Example 7 was obtained.

In the eighth embodiment, the content of the allylamine-based polymer and the content of the abrasive particles are large, and the mass ratio of the content of the allylamine-based polymer to the content of the abrasive grains is in the range of 0.002 to 0.400, and the carbon-based material film is used. The polishing rate was slower than that of Example 1, but the polishing rate of the carbon-based material film with respect to the insulating film was higher than that of the comparative example.

As shown in Table 2, in Comparative Example 1, Comparative Example 4, and Comparative Example 5 in which the polishing agent did not contain the allylamine-based polymer, the polishing rate of the insulating film was slow, and the polishing rate ratio was small. The reason for this is considered to be that, in the comparative examples, the protective film which lowers the polishing rate of the insulating film is relatively difficult to form on the insulating film.

In Comparative Example 2 and Comparative Example 3 in which abrasive grains having different materials from cerium oxide were used, the polishing rate of the carbon-based material film was slow, and the polishing rate ratio was small.

In Comparative Example 6 in which the mass ratio of the content of the allylamine-based polymer to the content of the abrasive grains was large, the polishing rate of the carbon-based material film was slow, and the polishing rate ratio was small. The reason for this is considered to be that the amount of adsorption of the allylamine-based polymer on the carbon-based material film is large.

In Comparative Example 7 in which the content of the allylamine-based polymer was small with respect to the content of the abrasive grains, the polishing rate of the carbon-based material film was fast, but the polishing rate ratio was low. The reason for this is considered to be that the amount of adsorption of the allylamine-based polymer to the insulating film is small.

In Comparative Example 8 in which the kinetic potential of cerium oxide in the polishing agent was extremely small, the polishing rate of the carbon-based material film was slow.

1, 11‧‧‧ substrate
2,12‧‧‧Oxide
3, 14‧‧‧ photoresist
4‧‧‧ slot department
13‧‧‧Carbon materials

1(a) to 1(f) are schematic cross-sectional views showing a conventional double patterning step. 2(a) to 2(h) are schematic cross-sectional views showing a step of forming a fine pattern.

no

Claims (12)

An abrasive for chemically mechanically polishing a substrate containing a carbon-based material and an insulating material to remove at least a portion of the carbon-based material, wherein the carbon-based material is subjected to X-ray photoelectron spectroscopy The amount of carbon measured is from 60 atm% to 95 atm%, and the abrasive contains cerium oxide-containing abrasive particles, an allylamine-based polymer, and water, and the content of the allylamine-based polymer is relative to the polishing. The mass ratio of the particles is from 0.002 to 0.400, and the abrasive particles have a positive charge in the abrasive. The abrasive according to claim 1, wherein the allylamine-based polymer contains a structural unit represented by the following general formula (I), a structural unit represented by the following general formula (II), At least one of a group consisting of a structural unit represented by the following formula (III), a structural unit represented by the following formula (IV), and a structural unit represented by the following formula (V); 1] Wherein R ¹¹ , R ¹² , R ² and R ³ each independently represent a hydrogen atom, an alkyl group or an aralkyl group, and the amine group and the nitrogen-containing ring may each independently form an acid addition salt], [Chemical 2 ] [wherein R ⁴¹ and R ⁴² each independently represent an alkyl group or an aralkyl group, R ⁵¹ and R ⁵² each independently represent an alkyl group or an aralkyl group, and D ^- represents a monovalent anion]. The abrasive according to claim 1 or 2, wherein the cerium oxide is colloidal cerium oxide. The abrasive according to any one of claims 1 to 3, further comprising an organic solvent. The abrasive according to any one of claims 1 to 4, which has a pH of 1.0 to 8.0. The abrasive according to any one of claims 1 to 5, further comprising an acid component. The abrasive according to any one of claims 1 to 6, wherein a polishing rate ratio of the carbon-based material to the insulating material is 50 or more. The abrasive according to any one of claims 1 to 7, which is stored in the form of a multi-liquid abrasive comprising: the abrasive particles and water a first liquid and a second liquid containing the allylamine-based polymer and water. A stock solution for an abrasive for use in obtaining a polishing stock solution for an abrasive according to any one of claims 1 to 8 and obtained by dilution with water Agent. A polishing method comprising: preparing a carbon-based material having a carbon amount of 60 atm% to 95 atm% as determined by X-ray photoelectron spectroscopy, and a substrate of an insulating material; and using the first aspect of the patent application The polishing agent according to any one of the eighth aspect, wherein the substrate is subjected to chemical mechanical polishing to remove at least a part of the carbon-based material. A polishing method comprising: preparing a carbon-based material having a carbon amount of 60 atm% to 95 atm% as determined by X-ray photoelectron spectroscopy, and a substrate of an insulating material; and water as in claim 9 And the step of obtaining the polishing agent by diluting the polishing agent with a storage liquid; and polishing the substrate by chemical mechanical polishing using the polishing agent to remove at least a portion of the carbon-based material. The polishing method according to claim 10, wherein the grinding is stopped in the grinding step when the insulating material is exposed.