JP2017092373A - Polishing composition and polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing composition which enables the achievement of both of the reduction in defects and a polishing speed in a polishing step.SOLUTION: A polishing composition comprises abrasive grains. The abrasive grains are subjected to surface modification by two or more kinds of organic compounds. The two or more kinds of organic compounds each have a functional group (A) which reacts with the abrasive grains to form a chemical bond, and another functional group (B). The functional groups (B) bind reversibly to each other or make a hydrogen bond to interact with each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polishing composition and a polishing method.

  With the improvement of semiconductor integrated circuit manufacturing technology, higher integration and higher speed operation of semiconductor elements have been demanded, and the flatness of the semiconductor substrate surface required in the manufacturing process of fine circuits in semiconductor elements has become more severe. Yes. For this reason, chemical mechanical polishing (CMP) has become an indispensable technique in the manufacturing process of semiconductor elements.

  In CMP, a semiconductor substrate is held, and the held semiconductor substrate is pressed onto a polishing pad attached on a surface plate. Further, the semiconductor substrate and the polishing pad are relatively moved while supplying a polishing composition containing abrasive grains and a reagent onto the polishing pad. At this time, due to the chemical reaction by the reagent and the mechanical polishing effect by the abrasive grains, the unevenness of the substrate surface can be shaved and the surface can be flattened (see, for example, Patent Document 1).

  In recent years, with the progress of miniaturization of semiconductor elements, fine defects caused by polishing processing such as smaller size Light Point Defects (LPD), which has not been a problem in the past, have affected the characteristics and yield of semiconductor elements. The demand for reducing defects in the polishing process has become increasingly severe. In response to such demands, methods for reducing defects in polishing processing include reducing the size of the abrasive grains and adding an additive made of a water-soluble polymer having the effect of protecting the surface of the object to be polished. However, these have the effect of reducing the polishing rate, and are not desirable from the viewpoint of the cost of the polishing process.

JP2015-168818A

  As described above, as a method for reducing defects in polishing processing, the abrasive grain size is reduced, or an additive made of a water-soluble polymer having an effect of protecting the surface of the object to be polished is added. These have the effect of reducing the polishing rate, and are not desirable from the viewpoint of the cost of the polishing process. As described above, there is a problem that improvement of the polishing rate and suppression of generation of defects are generally in a trade-off relationship, and it is difficult to achieve both reduction of defects and polishing rate in the polishing process.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a polishing composition capable of achieving both a reduction in defects in a polishing process and a high polishing rate.

  In order to achieve the above object, the present invention provides a polishing composition comprising abrasive grains, wherein the abrasive grains have a surface modified with two or more types of organic compounds, and the two or more types of organic compounds. Each has a functional group (A) that reacts with the abrasive grains to form a chemical bond and a functional group (B) other than that, and the two or more organic compounds are the functional group (B). Are different from each other, and the functional group (B) forms a reversible bond with each other or interacts by a hydrogen bond. For example, a carboxyl group and an amino group form an amide bond, which can be converted back to the original carboxyl group and amino group by hydrolysis. Under an aqueous solution, the carboxyl group and amino group form a bond by a reversible reaction. Is in a state of being.

  Thus, by making the abrasive grains modified with the two or more organic compounds, two or more different functional groups (B) may be present on the surface of the modified abrasive grains. it can. If it is an abrasive grain which has such a structure, the secondary aggregate with a large particle size by the interaction between abrasive grains through several types of functional group (B) which exists in the surface of the abrasive grain in polishing liquid Form. The secondary aggregate is formed by reversible chemical bonds or hydrogen bonds, and the secondary aggregate is crushed or plastically deformed by the pressure applied between the substrate to be polished and the polishing pad. It is possible to reduce defects while maintaining the above.

  At this time, the abrasive grains may be abrasive grains used for polishing materials such as metals, metal oxides, and metal nitrides, and examples thereof include oxides or hydroxides of silicon, titanium, zirconium, or aluminum. The Further, in the present invention, it is particularly preferable that one or more kinds of metal oxides or hydroxides selected from the group consisting of titanium, zirconium and aluminum are included.

  Moreover, it is preferable that the primary particle diameter of the abrasive grains is 5 nm or more and less than 40 nm.

  If the primary particle diameter of the abrasive grains is 5 nm or more, a sufficient polishing rate can be secured, and if the primary particle diameter of the abrasive grains is less than 40 nm, polishing defects such as scratches can be further reduced.

  The functional group (B) preferably contains any one selected from an amino group, a carboxyl group, a ureido group, a sulfo group, and a mercapto group.

  The secondary agglomeration state of the abrasive grains can be controlled by changing the type and ratio of the plural types of functional groups (B) for any group selected from these, thereby improving the polishing rate and the defect suppression effect. It becomes possible to control according to the purpose.

Moreover, it is preferable that the said organic compound is a silane compound which has a structure of Formula (1).
[Formula (1)] X—Si— (R ₁ ) (R ₂ ) (R ₃ )
_{(Wherein, R 1, R 2, R} 3: an alkoxy group, an alkyl group, a hydroxyl group, or H,
X: The functional group (B) according to claim 1, the alkyl group having the functional group (B) according to claim 1, or the aryl group having the functional group (B) according to claim 1. )

  A silane coupling agent is illustrated as an organic compound which modifies said abrasive grain.

  Moreover, in order to achieve the said objective, this invention provides the grinding | polishing method characterized by grind | polishing a semiconductor substrate using said polishing composition.

  If polishing using the polishing composition of the present invention, a high polishing rate can be maintained, and defects in the semiconductor substrate after polishing can be reduced.

  At this time, the semiconductor substrate to be polished can be a single crystal silicon substrate.

  The polishing method of the present invention can be suitably used particularly for polishing a single crystal silicon substrate.

  The polishing composition of the present invention controls the secondary aggregation state by the interaction between the functional groups present on the surface of the abrasive grains, and the secondary aggregate is crushed or plastically deformed during the polishing process. By achieving both improvement in polishing efficiency and suppression of defect generation, the polishing composition of the present invention can reduce defects while maintaining the polishing rate.

It is the schematic which showed an example of the single-side polish apparatus which can be used in the grinding | polishing method of this invention.

  Hereinafter, although an embodiment is described about the present invention, the present invention is not limited to this.

  As described above, as the miniaturization of semiconductor elements progresses, there is an increasing demand for reducing fine defects such as LPD in polishing such as CMP. However, it is necessary to secure a high polishing rate simultaneously with the reduction of defects, but there is a problem that there is a trade-off between the reduction of defects and the maintenance of the polishing rate, and it is difficult to achieve both.

  Accordingly, the present inventors have conducted intensive studies to solve such problems, and completed the polishing composition of the present invention described below.

  The polishing composition of the present invention contains abrasive grains. And this abrasive grain has the surface modified with two or more kinds of organic compounds. Further, the two or more kinds of organic compounds each have a functional group (A) that reacts with the abrasive grains and a functional group (B) other than the functional group, and the functional group (B) has a reversible bond with each other. They are formed or interact with each other through hydrogen bonds, and two or more kinds of organic compounds each have different functional groups (B).

  Thus, the surface of the abrasive grains contained in the polishing composition of the present invention has an organic compound having a functional group (B) other than the functional group (A) in addition to the functional group (A) that reacts with the abrasive grains. There are two or more types. By making the abrasive grains modified with the two or more organic compounds, two or more different functional groups (B) can be present on the surface of the modified abrasive grains. If it is an abrasive grain which has such a structure, a particle size is large by controlling the interaction between abrasive grains via a plurality of types of functional groups (B) present on the surface of the abrasive grain in the polishing liquid. A secondary aggregate is formed. Unlike ordinary agglomerates in which particles are strongly bonded to each other and cannot be crushed, these secondary agglomerates are formed by reversible chemical bonds or hydrogen bonds, and the secondary agglomerates are caused by the pressure applied between the substrate to be polished and the polishing pad. Aggregates can be crushed or plastically deformed. For this reason, although it is small, it can behave as a secondary aggregate having a large particle size, and the polishing efficiency can be improved. Further, when the secondary aggregate is crushed or plastically deformed by applying pressure, it behaves as primary particles having a small original particle size, so that generation of defects can be suppressed. Such an effect makes it possible to reduce defects while maintaining the polishing rate. In addition, the structure of the functional group (A) may be changed by a reaction with the abrasive grains accompanying the modification. For example, when a silane coupling agent having a methoxy group is used as an organic compound, the methoxy group of the silane coupling agent is hydrolyzed, and then dehydrated and condensed with an OH group or the like on the surface of the abrasive grains, so that atoms ( For example, a bond such as a metal atom) and Si—O— (metal atom) may be formed. However, the present invention is not limited to this, and the abrasive grains may be modified with an organic compound by other reactions.

  Moreover, although the method of modifying the surface of an abrasive grain with an organic compound can be selected freely, for example, the following method can be used. For example, the surface of the abrasive grains can be modified with the organic compound by dropping and mixing the organic compound directly on the powdery abrasive grains. In addition, for example, if abrasive grains are dispersed in a solvent such as alcohol or water, an organic compound is added thereto, and then the abrasive grains are collected to obtain abrasive grains whose surface is modified with an organic compound. it can. In addition, the coverage in particular of the 2 or more types of organic compound which modifies the surface of an abrasive grain is not restrict | limited, It can adjust suitably according to a grinding | polishing target object. Further, the functional group may be changed by dispersing the abrasive grains in a solvent and chemically changing the organic compound in a state where the organic compound is added thereto.

  The organic compound for modifying the abrasive grain surface can be appropriately selected according to the purpose. As this silane compound, those having the structure of the formula (1) are preferably used. As the silane compound, for example, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 1- [3- (trimethoxysilyl) propyl] urea can be used.

  In the present invention, the functional group (B) of the organic compound is selected from a functional group capable of forming a reversible bond with each other or a functional group that interacts by a hydrogen bond. The functional group (B) preferably contains any one selected from an amino group, a carboxyl group, a ureido group, a sulfo group, and a mercapto group.

  As described above, in the present invention, two or more organic compounds have different functional groups (B) from each other, and the functional groups (B) form a bond by a reversible reaction. Alternatively, the functional groups (B) interact with each other by forming a hydrogen bond, and in particular, each functional group (B) is any one of an amino group, a carboxyl group, a ureido group, a sulfo group, and a mercapto group. In the case of having a group, a secondary aggregate is formed by the interaction between the abrasive grains, and the secondary aggregate is crushed or plastically deformed during the polishing process, so that the effect of the present invention is further exhibited. The

  In addition, the combination of the functional groups (B) different from each other in two or more organic substances and the ratio thereof are not particularly limited, and can be appropriately adjusted according to the object to be polished.

  Moreover, regarding the functional group (A), two or more types of organic compounds may have different functional groups (A), or may have the same functional group (A). The functional group (A) is not limited as long as it is a functional group capable of reacting with the surface of the abrasive grains and forming a chemical bond. As a functional group (A), an alkoxy group, a silanol group, etc. can be used, for example.

  In the polishing composition of the present invention, abrasive grains containing at least one metal oxide or hydroxide selected from the group consisting of titanium, zirconium, or aluminum can be suitably used.

  Moreover, it is preferable that the primary particle diameter of the abrasive grains in the polishing composition of the present invention is 5 nm or more and less than 40 nm. If the primary particle diameter of the abrasive grains is 5 nm or more, a high polishing rate can be maintained, and if the primary particle diameter is relatively small abrasive grains having a primary particle diameter of less than 40 nm, the generation of scratches can be suppressed.

  The primary particle diameter of the abrasive grains is measured by measuring a particle image obtained by a transmission electron microscope (TEM) or a scanning electron microscope (SEM), and has a maximum diameter in a fixed direction of 100 or more particles, that is, a Feret diameter. It can be obtained by calculating an average value (average primary particle size).

  The shape of the primary particles of the abrasive grains is not particularly limited, and may be a spherical shape or a square shape. Further, the crystal structure is not particularly limited, and may be amorphous, single crystal, or polycrystalline. The shape and crystal structure of the primary particles of the abrasive grains can be appropriately selected according to the purpose.

  In the polishing composition of the present invention, the content of abrasive grains is preferably 0.1% by mass or more and 10% by mass or less, and particularly preferably 0.4% by mass or more and 5% by mass or less. If the abrasive content is 0.1% by mass or more, a high polishing rate can be obtained, and if it is 10% by mass or less, defects such as scratches are hardly generated.

  The pH of the polishing composition of the present invention is not particularly limited and can be appropriately selected according to the polishing object. The kind of pH adjuster for adjusting the pH of the polishing composition is not particularly limited, and the base is an aqueous potassium hydroxide solution, a tetramethylammonium hydroxide solution, and aqueous ammonia, and the acid is nitric acid, acetic acid, sulfuric acid, and Oxalic acid can be used.

  The polishing composition of the present invention may contain a water-soluble polymer, and it is preferable to use a nonionic surfactant or an anionic surfactant as the water-soluble polymer. More specifically, for example, polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylamide, polyethylene glycol, polyoxyalkylene alkyl ether, and polyether are preferably used as the nonionic surfactant. On the other hand, as the anionic surfactant, for example, polyacrylic acid or a salt thereof, polysulfonic acid or a salt thereof, polycarboxylic acid or a salt thereof is preferably used.

  Next, a polishing method using the polishing composition of the present invention will be described. In the following, a case where a semiconductor substrate is polished on one side will be described as an example. However, the present invention is not limited to this, and the polishing composition of the present invention can also be used for double-side polishing.

  For example, as shown in FIG. 1, the single-side polishing apparatus is a single-side polishing apparatus 10 including a surface plate 3 to which a polishing pad 4 is attached, a polishing composition supply mechanism 5, a polishing head 2, and the like. Can do.

  In such a polishing apparatus 10, the semiconductor substrate W is held by the polishing head 2, the polishing composition 1 of the present invention is supplied onto the polishing pad 4 from the polishing composition supply mechanism 5, and the surface plate 3 and the polishing head 2. Each is rotated to bring the surface of the semiconductor substrate W into sliding contact with the polishing pad 4 to perform polishing.

  At this time, the semiconductor substrate W to be polished can be a single crystal silicon substrate. The polishing method of the present invention is suitably used for polishing a single crystal silicon substrate, can perform polishing at a high polishing rate, and can obtain a single crystal silicon substrate with few defects after polishing.

  As described above, with the polishing method using the polishing composition of the present invention, a high polishing rate can be obtained, and generation of defects due to polishing on the surface of the semiconductor substrate can be suppressed.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples of the present invention, but the present invention is not limited to these examples.

Example 1
Zirconium oxide having a primary particle size of 6 nm is dispersed in alcohol to form a 10% by mass dispersion, and 3% by mass of 3-aminopropyltriethoxysilane and β-carboxyethyltriethoxysilane are added with stirring for 2 hours. Then, the surface of zirconium oxide was modified with these two kinds of organic compounds by collecting abrasive grains by centrifugation. At this time, the functional groups (A) of the two kinds of organic compounds are both ethoxy groups, and the functional groups (B) are amino groups and carboxyl groups, respectively.

  Subsequently, the zirconium oxide was dispersed in pure water so as to have a content of 1.0% by mass, and a potassium hydroxide solution was added so that the pH of the solution was 11.5 to prepare a polishing composition.

(Example 2)
Zirconium oxide with a primary particle size of 6 nm is dispersed in water to make a 10% by mass dispersion, 3% by mass of 3-mercaptopropyltrimethoxysilane is added, and a small amount of hydrogen peroxide is added while heating and stirring at 50 ° C., A mercapto group contained in 3-mercaptopropyltrimethoxysilane was reacted to form a sulfo group. 3% by mass of 3-aminopropyltriethoxysilane is added to the solution after the reaction, and the reaction is continued with stirring for 2 hours, and then the surface of the zirconium oxide is recovered from the two kinds of organic compounds by collecting the abrasive grains by centrifugation. Qualified with The functional groups (A) of these two kinds of organic compounds are a methoxy group and an ethoxy group, respectively, and the functional groups (B) are a sulfo group and an amino group, respectively.

  Subsequently, the zirconium oxide was dispersed in pure water so as to have a content of 1.0% by mass, and a potassium hydroxide solution was added so that the pH of the solution was 11.5 to prepare a polishing composition.

(Example 3)
Zirconium oxide with a primary particle size of 6 nm is dispersed in water to make a 10% by mass dispersion, 3% by mass of 3-mercaptopropyltrimethoxysilane is added, and a small amount of hydrogen peroxide is added while heating and stirring at 50 ° C., A mercapto group contained in 3-mercaptopropyltrimethoxysilane was reacted to form a sulfo group. After adding 3% by mass of β-carboxyethyltriethoxysilane to the solution after the reaction, stirring and reacting for 2 hours, the abrasive grains are collected by centrifugation, so that the surface of zirconium oxide is made of two kinds of organic compounds. Qualified with The functional groups (A) of these two kinds of organic compounds are a methoxy group and an ethoxy group, respectively, and the functional groups (B) are a mercapto group and a carboxyl group, respectively.

  This zirconium oxide was dispersed in pure water so that the content was 1.0% by mass, and a potassium hydroxide solution was added so that the pH of the solution was 11.5 to prepare a polishing composition.

Example 4
Titanium oxide with a primary particle size of 15 nm is dispersed in alcohol to make a 10% by mass dispersion, and 3% by mass of 3-aminopropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane are added with stirring for 2 hours. Then, the surface of zirconium oxide was modified with these two kinds of organic compounds by collecting abrasive grains by centrifugation. At this time, the functional groups (A) of the two kinds of organic compounds are an ethoxy group and a methoxy group, respectively, and the functional groups (B) are an amino group and a mercapto group, respectively.

  This titanium oxide was dispersed in pure water so that the content was 1.0% by mass, and a potassium hydroxide solution was added so that the pH of the solution was 11.5 to prepare a polishing composition.

(Example 5)
A titanium oxide having a primary particle diameter of 15 nm and a zirconium hydroxide having a primary particle diameter of 10 nm are dispersed in water at a ratio of 1: 1 to form a 10% by mass dispersion, and 3% by mass of 3-mercaptopropyltrimethoxysilane is added. While heating and stirring at 50 ° C., a small amount of hydrogen peroxide was added to react with the mercapto group to form a sulfo group. After adding 3% by mass of 3-aminopropyltriethoxysilane to the solution after the reaction, stirring and reacting for 2 hours, the abrasive grains are collected by centrifugation, so that two types of titanium oxide and zirconium hydroxide surfaces are obtained. The organic compound was modified. At this time, the functional groups (A) of the two kinds of organic compounds are a methoxy group and an ethoxy group, respectively, and the functional groups (B) are an amino group and a sulfo group.

  This zirconium hydroxide was dispersed in pure water so as to have a content of 1.0% by mass, and a potassium hydroxide solution was added so that the pH of the solution was 11.5 to prepare a polishing composition.

(Example 6)
Aluminum oxide having a primary particle size of 37 nm and zirconium hydroxide having a primary particle size of 10 nm are dispersed in alcohol at a ratio of 1: 1 to form a 10% by mass dispersion, and 3 aminopropyltriethoxysilane and 1- [ 3- (trimethoxysilyl) propyl] urea was added in an amount of 3% each, and after stirring for 2 hours, the reaction was continued, and then the abrasive grains were collected by centrifugation, so that the surface of the aluminum oxide and zirconium hydroxide was changed to two organic compounds. Qualified with At this time, the functional groups (A) of the two kinds of organic compounds are an ethoxy group and a methoxy group, respectively, and the functional groups (B) are an amino group and a ureido group, respectively.

  Disperse this mixture of aluminum oxide and zirconium oxide in pure water so that the content is 1.0% by mass, and then add a potassium hydroxide solution so that the pH of the solution is 11.5 to prepare a polishing composition. did.

(Example 7)
Aluminum oxide having a primary particle size of 48 nm is dispersed in alcohol to form a 10% by mass dispersion, and 3% by mass of 3-aminopropyltriethoxysilane and 1- [3- (trimethoxysilyl) propyl] urea with stirring. After adding and reacting with stirring for 2 hours, the surface of the aluminum oxide was modified with two kinds of organic compounds by collecting abrasive grains by centrifugation. The functional groups (A) in the two kinds of organic compounds are an ethoxy group and a methoxy group, respectively, and the functional groups (B) are an amino group and a ureido group, respectively.

  The aluminum oxide content was dispersed in pure water so as to be 1.0% by weight, and a potassium hydroxide solution was added so that the pH of the solution was 11.5 to prepare a polishing liquid.

(Example 8)
Zirconium oxide having a primary particle size of 3 nm is dispersed in alcohol to form a 10% by mass dispersion, and 3% by mass of 3-aminopropyltriethoxysilane and β-carboxyethyltriethoxysilane are added with stirring for 2 hours. Then, the surface of zirconium oxide was modified with these two kinds of organic compounds by collecting abrasive grains by centrifugation. At this time, the functional groups (A) of the two kinds of organic compounds are both ethoxy groups, and the functional groups (B) are amino groups and carboxyl groups, respectively.

  This zirconium oxide was dispersed in pure water so that the content was 1.0% by mass, and a potassium hydroxide solution was added so that the pH of the solution was 11.5 to prepare a polishing composition.

(Comparative Example 1)
A zirconium oxide having a primary particle size of 6 nm is dispersed in pure water so that the content is 1.0% by mass, and a potassium hydroxide solution is added so that the pH of the solution is 11.5 to prepare a polishing composition. did.

(Comparative Example 2)
Titanium oxide with a primary particle size of 15 nm is dispersed in alcohol to make a 10% by mass dispersion, 3% by mass of 3-aminopropyltriethoxysilane is added with stirring, and stirring is continued for 2 hours, followed by centrifugation. The titanium oxide surface was modified with one kind of organic compound by collecting the abrasive grains. This titanium oxide was dispersed in pure water so that the content was 1.0% by mass, and a potassium hydroxide solution was added so that the pH of the solution was 11.5 to prepare a polishing composition.

Using the polishing compositions of Examples 1 to 7 and Comparative Examples 1 and 2 above, single-side polishing of a single crystal silicon substrate having a diameter of 12 inches (300 mm) was performed under the following polishing conditions. As a polishing apparatus, Poli-762 (G & P Technology, Inc.) was used, and SUBA400 (manufactured by Nitta Haas Co., Ltd.) was used as a polishing pad. The load applied to the single crystal silicon substrate as the substrate to be polished was 193 g / cm ² , the platen rotation speed was 70 rpm, the head rotation speed was 70 rpm, and the supply amount of the polishing composition was 400 mL / min.

  SC-1 (29% ammonia water, 30% hydrogen peroxide water, pure water mixed solution, volume ratio: ammonia water: hydrogen peroxide water: pure water = 1: 1: a semiconductor substrate after polishing is a known technique. 10, 75 ° C., 5 minutes immersion) and SC-2 (30% hydrochloric acid, 30% hydrogen peroxide solution, pure water mixed solution, volume ratio: hydrochloric acid: hydrogen peroxide solution: pure water = 1: 1: 10, RCA cleaning was performed by immersion at 75 ° C. for 5 minutes. Thereafter, as a defect evaluation in the polishing process, an LPD defect (0.100 μm or more) on the substrate surface was evaluated by visual inspection with a condenser lamp in a dark room and a surface inspection apparatus (SP-1 manufactured by KLA-Tencor). In the visual inspection, those in which defects were observed were judged as rejected, and those in which no defects were observed were judged as acceptable.

  Table 1 summarizes the polishing rate of polishing using the polishing compositions of Examples 1 to 7 and Comparative Examples 1 and 2, results of visual inspection, and the number of LPD defects.

  As can be seen from Table 1, Examples 1 to 8 have a higher polishing rate than Comparative Examples 1 and 2, no relatively large defects observed by visual inspection, and fine defects such as LPD. The number of is also small. That is, it was confirmed that the polishing composition of the present invention can secure a high polishing rate and suppress the occurrence of defects due to polishing.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

1 ... polishing composition, 2 ... polishing head, 3 ... surface plate,
4 ... polishing pad, 5 ... polishing composition supply mechanism,
10: Single-side polishing device,
W: Semiconductor substrate.

Claims (7)

A polishing composition comprising abrasive grains,
The abrasive grains are those whose surfaces are modified with two or more organic compounds,
The two or more kinds of organic compounds each have a functional group (A) that reacts with the abrasive grains to form a chemical bond and another functional group (B),
The two or more kinds of organic compounds are different from each other in the functional group (B),
The polishing composition, wherein the functional groups (B) form reversible bonds with each other or interact with each other by hydrogen bonds.   The polishing composition according to claim 1, wherein the functional group (B) contains any one selected from an amino group, a carboxyl group, a ureido group, a sulfo group, and a mercapto group. The polishing composition according to claim 1, wherein the organic compound is a silane compound having a structure of the formula (1).
[Formula (1)] X—Si— (R ₁ ) (R ₂ ) (R ₃ )
_{(Wherein, R 1, R 2, R} 3: an alkoxy group, an alkyl group, a hydroxyl group, or H,
X: The functional group (B) according to claim 1, the alkyl group having the functional group (B) according to claim 1, or the aryl group having the functional group (B) according to claim 1. )   The polishing composition according to any one of claims 1 to 3, wherein the abrasive grains contain one or more oxides or hydroxides selected from the group consisting of titanium, zirconium, and aluminum. object.   The polishing composition according to any one of claims 1 to 4, wherein a primary particle diameter of the abrasive grains is 5 nm or more and less than 40 nm.   A polishing method comprising polishing a semiconductor substrate using the polishing composition according to any one of claims 1 to 5.   The polishing method according to claim 6, wherein the semiconductor substrate to be polished is a single crystal silicon substrate.

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