TW202100708A - Polishing composition - Google Patents

Abstract

An object of the present invention is to provide a new polishing composition that contributes to improving the quality of a device. There is provided a polishing composition containing: an abrasive grain having an organic acid immobilized on a surface thereof; a first water-soluble polymer having a sulfonic acid group or a group having a salt thereof, or a carboxyl group or a group having a salt thereof; a second water-soluble polymer different from the first water-soluble polymer; a nonionic surfactant; and an aqueous carrier, wherein the polishing composition is used for polishing an object to be polished.

Description

Polishing composition

The present invention relates to a polishing composition.

Due to the high integration brought about by the miniaturization of the LSI manufacturing process, the electronic equipment represented by the computer has achieved high performance such as miniaturization, multi-function, and high-speed. Regarding the novel microfabrication technology accompanying the high integration of these LSIs, the chemical mechanical polishing (CMP) method is used. The CMP method is frequently used in LSI manufacturing steps, especially in the planarization of the interlayer insulating film, the formation of metal studs, and the formation of embedded wiring (damascene wiring) in the multilayer wiring formation step.

The formation of metal studs or wiring of semiconductor devices is generally performed by forming a conductive layer made of metal on a silicon oxide film, a silicon nitride film, a polysilicon film, etc., with recesses formed, and then polishing and removing the conductor Part of the layer until the film is exposed. This polishing step is roughly divided into a main (main) polishing step for polishing to remove most of the object to be removed, and a buff polishing step for finishing polishing the object (for example, Patent Document 1) . [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2004-273502 A

[The problem to be solved by the invention]

In recent years, the above-mentioned films have become thinner, and the inventors of the present invention have discovered that the quality of the final device manufactured by only performing the main polishing step and the polishing step using a general polishing composition may be insufficient. Therefore, the problem to be solved by the present invention is to provide a novel polishing composition that helps to improve the device quality of the final product. [Means to solve the problem]

In order to solve the above-mentioned problems, the inventors actively repeated deliberate research. As a result, it has been found that the above-mentioned problems can be solved by providing the following polishing composition, which includes abrasive grains in which an organic acid is immobilized on the surface, includes a group having a sulfonic acid group or its salt, or has The first water-soluble polymer of the carboxyl group or its salt base, the second water-soluble polymer different from the aforementioned first water-soluble polymer, the nonionic surfactant, and the water-based carrier, and are used for polishing objects Grind. [Invention Effect]

The polishing composition according to the present invention helps to improve the device quality of the final product.

The present invention is explained below. In addition, the present invention is not limited to the following embodiments. And, unless otherwise specified, the operation and physical properties are measured under the conditions of room temperature (20-25°C)/relative humidity 40-50%RH.

The present invention is a polishing composition comprising: abrasive grains formed by immobilizing an organic acid on the surface, a first water-soluble polymer containing a group having a sulfonic acid group or a salt thereof, or a group having a carboxyl group or a salt thereof, The second water-soluble polymer, nonionic surfactant, and water-based carrier, which are different from the aforementioned first water-soluble polymer, are used for polishing objects to be polished. Based on these polishing compositions, it is helpful to improve the device quality of the final product.

[Device manufacturing process] In one embodiment of the present invention, the device is a semiconductor device. In one embodiment of the present invention, a film to be polished is formed on a substrate (for example, a silicon wafer). The object to be polished is not particularly limited, and is, for example, a Si-based material, such as an object to be polished including silicon-silicon bonds, nitrogen-silicon bonds, or oxygen-silicon bonds. According to this embodiment, the roughness can be eliminated by the previous grinding, which has the technical effect of reducing the processing time and steps in the subsequent manufacturing process.

In this embodiment, examples of polishing objects having silicon-oxygen bonds include silicon oxide film, BD (black diamond: SiOCH), SiOC, FSG (fluorosilicate glass), HSQ (hydrogenated silsesquioxane) , CYCLOTENE, SiLK, MSQ (methyl silsesquioxane), etc. Examples of polishing objects with silicon-silicon bonds include polycrystalline silicon, amorphous silicon, single crystal silicon, n-type doped single crystal silicon, p-type doped single crystal silicon, phosphorus-doped polycrystalline silicon, boron-doped polycrystalline silicon, and SiGe And other Si-based alloys. Examples of the polishing object having a silicon-nitrogen bond include a silicon nitride film, SiCN (silicon carbonitride), and the like.

According to another embodiment of the present invention, the polishing object is carbon, DFR (Dry film resist), SiC, or the like.

In one embodiment of the present invention, the manufacturing process of the device includes a main body grinding step and a polishing and grinding step. In one embodiment of the present invention, the manufacturing process of the device includes a preliminary grinding step, a main body grinding step, and a polishing and grinding step. Before, after, or before and after the polishing steps, a film forming step of the polishing object to be polished may be included. In this embodiment, prior to the main polishing step for removing most of the object to be polished, the preliminary polishing step is performed to minimize the influence of the surface roughness of the substrate or the object to be polished on the final device. In addition, since the number of device defects can also be intentionally reduced, the reliability of the device as the final product is improved. Moreover, the roughness can be eliminated by pre-grinding, and the processing time and steps in the subsequent manufacturing process can be reduced.

In one embodiment of the present invention, the film thickness of the polishing object is not particularly limited. In one embodiment of the present invention, the method for forming a film of the object to be polished is not particularly limited, and conventional film forming techniques such as ALD, CVD, and PVD can be applied. In order to reduce the film thickness of the polishing object more efficiently, ALD is preferably used, but of course it is not limited to this.

In one embodiment of the present invention, the polishing composition can be used for polishing an object to be polished in any step, but is preferably used for polishing in a preliminary polishing step. With this embodiment, the influence of the surface roughness on the final device can be minimized. In addition, since the number of device defects can also be intentionally reduced, the reliability of the device as the final product is improved. Moreover, the roughness can be eliminated by pre-grinding, and the processing time and steps in the subsequent manufacturing process can be reduced. Therefore, in an embodiment of the present invention, a semiconductor device manufacturing process is provided, which includes a preliminary polishing step, a main body polishing step, and a polishing polishing step, and the polishing composition of the embodiment of the present invention is used as one of the preliminary polishing steps. Grind the composition. With this embodiment, the influence of the surface roughness on the final device can be minimized. In addition, since the number of device defects can also be intentionally reduced, the reliability of the device as the final product is improved. In one embodiment of the present invention, the polishing composition used in the preliminary polishing step, the main polishing step, and the polishing polishing step may be different from each other. That is, the composition of the polishing composition in the preliminary polishing step, the composition of the polishing composition in the main polishing step, and the polishing composition in the polishing step may be completely different.

[Grinding method] In one embodiment of the present invention, there is provided a method of polishing an object to be polished, which includes using a polishing composition to polish the object to be polished. According to this grinding method, the device quality of the final product is improved. In one embodiment of the present invention, for example, using a polishing device, a polishing object is pressed against a polishing pad, and the polishing composition is flowed out while rotating it.

As the polishing device, a general polishing device with a polishing platen to which a polishing pad can be attached, such as a holder for holding objects to be polished and a motor capable of changing the number of rotations, can be used. As the polishing pad, general non-woven fabric, polyurethane, porous fluororesin, etc. can be used without particular limitation.

In one embodiment of the present invention, it is preferable to appropriately set the polishing conditions in the preliminary polishing step, the main body polishing step, and the polishing polishing step.

In an embodiment of the present invention, the upper limit of the pressure of the polishing object and the polishing pad in the preliminary polishing step is preferably less than 3 psi, more preferably less than 2 psi, more preferably less than 1.6 psi, and still more preferably less than 1.5 psi. In this embodiment, the lower limit of the pressure of the polishing object and the polishing pad in the preliminary polishing step is preferably 0.1 psi or more, more preferably 0.3 psi or more, and still more preferably 0.5 psi or more. In this embodiment, the upper limit of the number of rotations of the grinding head (carrier) in the preliminary grinding step is preferably less than 120 rpm, more preferably less than 100 rpm, and still more preferably less than 80 rpm. In this embodiment, the lower limit of the number of rotations of the grinding head in the preliminary grinding step is preferably 50 rpm or more, more preferably 60 rpm or more, and still more preferably 70 rpm or more. In this embodiment, the upper limit of the number of rotations of the platen in the preliminary grinding step is preferably less than 120 rpm, more preferably less than 100 rpm, and still more preferably less than 90 rpm. In this embodiment, the lower limit of the number of rotations of the platen in the preliminary grinding step is preferably 50 rpm or more, more preferably 60 rpm or more, and still more preferably 70 rpm or more. In the preliminary polishing step, the supply amount of the source outflow is not limited, but it is preferable that the surface of the polishing object is covered with the polishing composition, for example, 50 to 300 ml/min. In addition, the grinding time is not particularly limited, but it is preferably 5 to 60 seconds.

In this embodiment, the upper limit of the pressure of the polishing object and the polishing pad in the main polishing step is preferably less than 10 psi, more preferably less than 7 psi, and still more preferably less than 5 psi. In this embodiment, the lower limit of the pressure of the polishing object and the polishing pad in the main polishing step is preferably 1 psi or more, more preferably 1.5 psi or more, still more preferably 1.6 psi or more, more preferably 2 psi or more, and still more preferably 3 psi or more. In this embodiment, the upper limit of the number of rotations of the grinding head in the main grinding step is preferably less than 130 rpm, more preferably less than 120 rpm, and still more preferably less than 110 rpm. In this embodiment, the lower limit of the number of rotations of the polishing head in the main polishing step is preferably 80 rpm or more, more preferably 90 rpm or more, and still more preferably 100 rpm or more. In this embodiment, the upper limit of the number of rotations of the platen in the main grinding step is preferably less than 140 rpm, more preferably less than 130 rpm, and still more preferably less than 120 rpm. In this embodiment, the lower limit of the number of rotations of the platen in the main grinding step is preferably 80 rpm or more, more preferably 90 rpm or more, and still more preferably 100 rpm or more. The amount of supply from the source in the main body polishing step is not limited, but it is preferred that the surface of the object to be polished is covered with the polishing composition, for example, 50 to 300 ml/min. Moreover, the grinding time is not particularly limited, but it is preferably 30 to 120 seconds.

In this embodiment, the upper limit of the pressure of the polishing object and the polishing pad in the polishing step is preferably less than 3 psi, more preferably less than 2 psi, more preferably less than 1.6 psi, and more preferably less than 1.5 psi. In this embodiment, the lower limit of the pressure of the polishing object and the polishing pad in the polishing step is preferably 0.3 psi or more, more preferably 0.6 psi or more, and still more preferably 0.8 psi or more. In this embodiment, the upper limit of the number of rotations of the polishing head in the polishing step is preferably less than 100 rpm, more preferably less than 90 rpm, and still more preferably less than 80 rpm. In this embodiment, the lower limit of the number of rotations of the polishing head in the polishing step is preferably 50 rpm or more, more preferably 60 rpm or more, and still more preferably 70 rpm or more. In this embodiment, the upper limit of the number of rotations of the platen in the polishing step is preferably less than 120 rpm, more preferably less than 100 rpm, and still more preferably less than 90 rpm. In this embodiment, the lower limit of the number of rotations of the platen in the polishing step is preferably 60 rpm or more, more preferably 70 rpm or more, and still more preferably 80 rpm or more. In the polishing step, the amount of supply from source to source is not limited, but it is preferable that the surface of the object to be polished is covered with the polishing composition, for example, 50 to 300 ml/min. In addition, the grinding time is not particularly limited, but it is preferably 5 to 60 seconds.

In one embodiment of the present invention, (the pressure of the polishing object and the polishing pad in the preliminary polishing step)/(the pressure of the polishing object and the polishing pad in the main polishing step) is preferably less than 1.0, more preferably 0.75 or less, and More preferably, it is 0.5 or less. In one embodiment of the present invention, (the pressure of the polishing object and the polishing pad in the preliminary polishing step)/(the pressure of the polishing object and the polishing pad in the main polishing step) is preferably 0.15 or more, more preferably 0.20 or more, and More preferably, it is 0.25 or more.

In one embodiment of the present invention, (the pressure of the polishing object and the polishing pad in the polishing step)/(the pressure of the polishing object and the polishing pad in the main polishing step) is preferably less than 1.0, more preferably 0.75 or less, and More preferably, it is 0.5 or less. In an embodiment of the present invention, (the pressure of the polishing object and the polishing pad in the polishing step)/(the pressure of the polishing object and the polishing pad in the main polishing step) is preferably 0.15 or more, more preferably 0.20 or more, and More preferably, it is 0.2 or more.

In one embodiment of the present invention, (the pressure of the polishing object and the polishing pad in the polishing step)/(the pressure of the polishing object and the polishing pad in the preliminary polishing step) is preferably 3.0 or less, more preferably 2.5 or less, and more Preferably it is 2.0 or less. In one embodiment of the present invention, (pressure of polishing object and polishing pad in polishing step)/(pressure of polishing object and polishing pad in preliminary polishing step) is preferably 0.1 or more, more preferably 0.3 or more, and More preferably, it is 0.5 or more.

In one embodiment of the present invention, before the main body polishing step, a preliminary polishing step is performed, and after the main body polishing step, a polishing and polishing step is performed. In one embodiment of the present invention, after the polishing step, at least one of cleaning and polishing treatment and cleaning treatment can also be provided. Moreover, as a cleaning composition or a cleaning composition, conventionally known ones can be suitably used.

[Polishing composition] In one embodiment of the present invention, the polishing composition includes: abrasive grains in which an organic acid is immobilized on the surface, and a first water-soluble highly water-soluble group having a sulfonic acid group or a salt thereof, or a carboxyl group or a salt thereof. The molecule, a second water-soluble polymer different from the aforementioned first water-soluble polymer, a nonionic surfactant, and an aqueous carrier are used for polishing objects to be polished.

[Abrasive particles made by immobilizing organic acid on the surface] In one embodiment of the present invention, the polishing composition includes abrasive grains (also referred to as "abrasive grains" in this specification) formed by immobilizing an organic acid on the surface. The abrasive grains contained in the polishing composition have the function of mechanically polishing the object to be polished.

In one embodiment of the present invention, specific examples of abrasive grains are particles made of metal oxides such as silicon dioxide, aluminum oxide, zirconium oxide, and titanium oxide. The abrasive grains can be used alone or in combination of two or more kinds. In addition, commercially available products or synthetic products can be used for the abrasive grains. Among the abrasive particles, silica is preferred, fuming silica and colloidal silica are more preferred, and colloidal silica is particularly preferred. As the manufacturing method of colloidal silica, sodium silicate method and sol-gel method are exemplified. Colloidal silica manufactured by any of the manufacturing methods can be preferably used as the abrasive grains of the present invention. However, colloidal silica produced by a sol-gel method that can be produced with high purity is preferred.

In an embodiment of the present invention, the aforementioned abrasive grains are abrasive grains formed by immobilizing an organic acid on the surface. If the abrasive grains obtained by immobilizing an organic acid on the surface are not used, the desired effect of the present invention cannot be exhibited. In particular, when the pH of the polishing composition is adjusted to an acidic region, if the abrasive grains formed by immobilizing an organic acid on the surface are not contained, the surface roughness of the polishing object may deteriorate.

In one embodiment of the present invention, the aforementioned organic acid is not particularly limited, and can be exemplified by sulfonic acid, carboxylic acid, phosphoric acid, etc., preferably sulfonic acid. In addition, the organic acid-immobilized silica on the surface is derived from the acidic groups of the above-mentioned organic acids (such as sulfo groups, carboxyl groups, phosphoric acid groups, etc.) by covalent bonding (through the linking group structure as appropriate) and is fixed on the surface of the silica . Here, the so-called link base structure means any structure between the surface of silicon dioxide and the organic acid. Therefore, the surface of silica with organic acid immobilized can form acidic groups derived from organic acids by direct covalent bonding to the surface of silica, and can also be fixed to the dioxide by covalent bonding through the structure of the linking group. Formed on the surface of silicon. The method of introducing these organic acids to the surface of silicon dioxide is not particularly limited. There are methods of introducing the surface of silicon dioxide in the form of mercapto groups or alkyl groups, and then oxidizing to sulfonic acid or carboxylic acid. In addition, there are methods to bond with protective groups. It is a method of introducing the above-mentioned organic acid group into the surface of silicon dioxide and then removing the protecting group.

As a specific synthesis method for fixing organic acid on the surface of silica, if sulfonic acid, which is a kind of organic acid, is fixed on the surface of silica, for example, "Sulfonic acid-functionalized silica Through quantitative oxidation of thiol groups" Chem. Commun. 246-247 (2003). Specifically, 3-mercaptopropyltrimethoxysilane, such as a sulfhydryl group-containing silane coupling agent, is coupled to silicon dioxide Then, the sulfhydryl group is oxidized with hydrogen peroxide to obtain silica with sulfonic acid immobilized on the surface. The colloidal silica with the surface modified by sulfonic acid in the embodiment of the present invention is also manufactured in the same way.

If carboxylic acid is immobilized on the surface of silica, for example, "Novel Silane Coupling Agents Containing a Photo labile 2-Nitrobenzyl Ester for Introduction of a Carboxy Group on the Surface of Silica Gel", Chemistry Letters, 3, 228-229 (2000). Specifically, it will contain the photoreactive 2-nitro group The silane coupling agent of benzyl ester is coupled to silica and irradiated with light to obtain silica with carboxylic acid immobilized on the surface.

In one embodiment of the present invention, the average primary particle size of the aforementioned abrasive particles is preferably 10 nm or more, more preferably 15 nm or more, still more preferably 20 nm or more, still more preferably 25 nm or more, and still more preferably 30 nm or more. In the polishing composition of the embodiment of the present invention, the average primary particle size of the abrasive grains is preferably 60 nm or less, more preferably 50 nm or less, and still more preferably 40 nm or less. By making the abrasive grains have the above average primary particle size, it has the effect of reducing scratches, reducing defects, and increasing the polishing speed. The average primary particle diameter of the present invention can use the value measured by the method described in the examples.

In one embodiment of the present invention, the average secondary particle size of the aforementioned abrasive grains is preferably 40 nm or more, more preferably 45 nm or more, still more preferably 50 nm or more, still more preferably 55 nm or more, and still more preferably 60 nm or more , And more preferably 65nm or more. In one embodiment of the present invention, the average secondary particle size of the aforementioned abrasive particles is preferably less than 100 nm, more preferably 90 nm or less, more preferably 80 nm or less, and still more preferably 70 nm or less. By making the abrasive grains have the above-mentioned average secondary particle size, there is an effect of increasing the polishing rate. The average secondary particle diameter of the present invention can adopt the value measured by the method described in the examples. In addition, if the average secondary particle size of the abrasive grains is 100 nm or more, the dispersion stability of the abrasive grains may decrease.

In one embodiment of the present invention, in the particle size distribution of the abrasive particles in the polishing composition obtained by the laser diffraction scattering method, the particle diameter D90 when the cumulative particle mass reaches 90% from the side of the fine particles and 10% The lower limit of the ratio of particle diameter D10 (also referred to as "D90/D10" in this specification) at this time is preferably 1.3 or more, more preferably 1.4 or more, still more preferably 1.5 or more, and still more preferably 1.6 or more. By being the lower limit, there is an effect of increasing the polishing speed. In one embodiment of the present invention, the upper limit of D90/D10 is preferably 4.0 or less, more preferably 3.5 or less, still more preferably 3.0 or less, and still more preferably 2.0 or less.

In one embodiment of the present invention, the length-to-width ratio of the abrasive grains is preferably 1.05 or more, more preferably 1.10 or more, and still more preferably 1.15 or more. With this embodiment, there is a technical effect of increasing the polishing speed. In one embodiment of the present invention, the length and width ratio of the abrasive grains is preferably 5 or less, more preferably 2 or less, and still more preferably 1.5 or less. With this embodiment, there are technical effects of improving dispersion stability and reducing the number of defects. In addition, the method for measuring the aspect ratio of abrasive grains is the method described in the examples.

In one embodiment of the present invention, in the aforementioned polishing composition, from the viewpoint of increasing the polishing rate or reducing the surface roughness after polishing, the content of the aforementioned abrasive grains is preferably more than 0.001% by mass, more preferably 0.005% by mass or more, and more Preferably it is 0.01 mass% or more, more preferably 0.05 mass% or more, still more preferably 0.1 mass% or more, still more preferably more than 0.01 mass%, still more preferably 0.3 mass% or more, and may be 0.8 mass% or more, It can be 1.2% by mass or more, 2% by mass or more, 3% by mass or more, or 4% by mass or more. In one embodiment of the present invention, in the aforementioned polishing composition, from the viewpoint of reducing scratches or reducing the number of defects, the content of the aforementioned abrasive grains is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 15 mass% or less, more preferably 10 mass% or less, still more preferably 7 mass% or less, can be 5 mass% or less, can be 4 mass% or less, can be 3 mass% or less, can be 2 mass% or less , Can be 1 mass% or less, can be less than 1 mass%, can be 0.8 mass% or less, can be 0.7 mass% or less, can be 0.6 mass% or less. In addition, in this specification, the content of a certain substance, etc., means the total amount when the substance contains two or more kinds.

(The first water-soluble polymer) In one embodiment of the present invention, the polishing composition includes a first water-soluble polymer. The first water-soluble polymer contains a group having a sulfonic acid group or a salt thereof, or a group having a carboxyl group or a salt thereof.

In one embodiment of the present invention, the first water-soluble polymer has a benzene ring. In this embodiment, the benzene ring may be incorporated into the main chain of the first water-soluble polymer, or it may be incorporated as a side chain group.

In one embodiment of the present invention, the first water-soluble polymer may contain heteroatoms in at least one of its main chain and side chains, but from the viewpoint of effectively exerting the desired effect of the present invention, it is preferable that the first water-soluble polymer does not contain heteroatoms. In addition, examples of the hetero atom include at least one of an oxygen atom, a nitrogen atom, and a sulfur atom.

In one embodiment of the present invention, the aforementioned first water-soluble polymer includes a structural unit represented by the following formula (1):

R ⁹ is a hydrogen atom or a methyl group, R ¹⁰ and R ¹¹ are each independently a hydrogen atom, -COOR ¹² or -G, but R ¹⁰ and R ^{11 are} not a hydrogen atom at the same time, -G is a sulfonic acid group,

However, * indicates the bonding position, R ¹² , R ¹³ and R ¹⁵ are each independently a hydrogen atom, an alkyl group with 1 to 12 carbons, a hydroxyalkyl group with 1 to 12 carbons or a relative cation, and R ¹⁴ is a divalent group . With this embodiment, the desired effect of the present invention can be efficiently exhibited. In addition, in this specification, * indicates the bonding position.

In one embodiment of the present invention, the first water-soluble polymer may include two or more different structural units represented by the above formula (1).

Here, the alkyl group having 1 to 12 carbon atoms may be linear or branched, and examples include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, Nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, hexadecyl, stearyl, eicosyl, behenyl, tetracosyl Ethyl, triacontanyl, isopropyl, isobutyl, tertiary butyl, isopentyl, neopentyl, tertiary pentyl, isoheptyl, 2-ethylhexyl, isodecyl.

In addition, examples of the hydroxyalkyl group having 1 to 12 carbon atoms are those in which at least one hydrogen atom of the alkyl group having 1 to 12 carbon atoms is substituted with a hydroxyl group.

In addition, examples of the divalent group include an alkylene group having 1 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, and the like. The alkylene having 1 to 12 carbon atoms is a divalent substituent in which two hydrogens of the alkylene having 1 to 12 carbon atoms are removed. In addition, the arylene group having 6 to 24 carbon atoms is preferably phenylene or naphthalenediyl.

In addition, examples of the relative cation are ammonium ion or sodium ion.

In an embodiment of the present invention, R ⁹ is a hydrogen atom or a methyl group, at least one of R ¹⁰ and R ¹¹ is -G, and -G is a sulfonic acid group or

R ¹³ is a hydrogen atom, an alkyl group with 1 to 12 carbons, a hydroxyalkyl group with 1 to 12 carbons, or a relative cation.

In one embodiment of the present invention, two or more different constituent units represented by the above formula (1) are included, and one constituent unit has R ⁹ as a hydrogen atom or a methyl group, and at least one of R ¹⁰ and R ¹¹ is COOR ¹² , R ¹² is a hydrogen atom or a relative cation, and one constituent unit is represented by R ⁹ being a hydrogen atom or a methyl group, at least one of R ¹⁰ and R ¹¹ is -G, and -G is a sulfonic acid group or

R ¹³ is a hydrogen atom, an alkyl group with 1 to 12 carbons, a hydroxyalkyl group with 1 to 12 carbons, or a relative cation.

In one embodiment of the present invention, R ⁹ is a hydrogen atom or a methyl group, R ¹⁰ and R ¹¹ are respectively -COOR ¹² and a hydrogen atom, and R ¹² is a hydrogen atom or a relative cation. At this time, it is particularly preferable that the pH is less than 7.0, and more preferably less than 5.0.

In one embodiment of the present invention, the aforementioned first water-soluble polymer includes R ^{9 which} is a hydrogen atom or a methyl group, R ¹⁰ and R ¹¹ are respectively -COOR ¹² and a hydrogen atom, and R ¹² is a hydrogen atom or a relative cation constituent unit ; And, R ⁹ is a hydrogen atom or a methyl group, R ¹⁰ and R ¹¹ are both -COOR ¹² , and R ¹² is a hydrogen atom or a relative cation constituent unit. At this time, it may be in an anhydrous state, but it is preferably not an anhydrous state.

In one embodiment of the present invention, R ⁹ is a hydrogen atom or a methyl group, R ¹⁰ and R ¹¹ are both -COOR ¹² , a hydrogen atom, and R ¹² is a hydrogen atom or a relative cation.

In one embodiment of the present invention, the aforementioned first water-soluble polymer includes R ^{9 which} is a hydrogen atom or a methyl group, R ¹⁰ and R ¹¹ are respectively -COOR ¹² and a hydrogen atom, and R ¹² is a hydrogen atom or a relative cation constituent unit ; And, R ⁹ is a hydrogen atom or a methyl group, at least one of R ¹⁰ and R ¹¹ is -COOR ¹² , and R ¹² is a structural unit of a hydrogen atom and an alkyl group with 1 to 12 carbon atoms.

In an embodiment of the present invention, the aforementioned first water-soluble polymer includes R ⁹ being a hydrogen atom or a methyl group, at least one of R ¹⁰ and R ¹¹ being -COOR ¹² , and R ¹² being a hydrogen atom or a relative cation constituent unit ; And R ⁹ is a hydrogen atom or a methyl group, at least one of R ¹⁰ and R ¹¹ is -G, -G is

R ¹⁴ is a divalent group, and R ¹⁵ is a hydrogen atom, an alkyl group with 1 to 12 carbons, a hydroxyalkyl group with 1 to 12 carbons, or a relative cation constituent unit.

In one embodiment of the present invention, R ⁹ is a hydrogen atom or a methyl group, at least one of R ¹⁰ and R ¹¹ is -G, and -G is

R ¹⁴ is a divalent group, R ¹⁵ is a hydrogen atom, an alkyl group with 1 to 12 carbons, a hydroxyalkyl group with 1 to 12 carbons, or a relative cation.

In one embodiment of the present invention, the aforementioned first water-soluble polymer is a copolymer of sulfonic acid and carboxylic acid (also referred to as "sulfonic acid/carboxylic acid copolymer"). The copolymer of sulfonic acid and carboxylic acid contains a structural unit derived from a monomer having a sulfonic acid group and a structural unit derived from a monomer having a carboxylic acid group.

In one embodiment of the present invention, examples of monomers having sulfonic acid groups are, for example, the polyalkylene glycol monomers (A) described in paragraphs [0019] to [0036] of JP 2015-168770 A ), or the sulfonic acid group-containing monomer (C) described in paragraphs [0041] to [0054] of the same publication.

In one embodiment of the present invention, examples of monomers having carboxylic acid groups are, for example, acrylic acid, methacrylic acid, crotonic acid, α-hydroxyacrylic acid, α-hydroxymethacrylic acid, and their metal salts and ammonium salts. , Organic amine salts and other salts.

In one embodiment of the present invention, the molar ratio of the constituent unit derived from the monomer having a sulfonic acid group to the constituent unit derived from the monomer having the carboxylic acid group in the sulfonic acid/carboxylic acid copolymer is preferably the source The structural unit of the monomer having a sulfonic acid group: the structural unit derived from the monomer having a carboxylic acid group=5:95~95:5, more preferably 10:90~90:10, and more preferably 30: 70~70:30, more preferably 45:55~65:35, best 50:50~60:40.

In one embodiment of the present invention, the weight average molecular weight of the first water-soluble polymer is preferably 1000 or more based on the viewpoint of the adsorption rate to the polishing object (that is, the ease of adsorption to the polishing object). 2000 or above, 3000 or above, 4000 or above, 5000 or above, 6000 or above, 6500 or above, 7000 or above, 8000 or above, 9000 or above, 9500 or above, 10,000 or above, 15,000 or above, or more than 15,000. In one embodiment of the present invention, the weight average molecular weight of the first water-soluble polymer is preferably 100,000 or less based on the viewpoint of the detachment rate from the polishing object (the ease of detachment from the polishing object described later), 30,000 or less, 25,000 or less, 20,000 or less, 15,000 or less, 10,000 or less, 9500 or less, 9,000 or less, 8,000 or less, 7,000 or less, 6,500 or less, or less than 6,500. In this embodiment, based on the viewpoint of reducing the number of defects in polishing objects containing oxygen-silicon bonds, the weight average molecular weight is preferably more than 15,000. Based on the viewpoint of reducing the number of defects in polishing objects containing nitrogen-silicon bonds, the weight average The molecular weight is preferably less than 6,500. From the viewpoint of reducing the number of defects of the polishing object containing silicon-silicon bonds, the weight average molecular weight is preferably 65 to 15,000.

In addition, in this specification, the weight average molecular weight is measured by a gel permeation chromatography (GPC) using polystyrene with a known molecular weight as a reference substance.

In one embodiment of the present invention, the content of the first water-soluble polymer relative to the total mass of the polishing composition is preferably 0.001% by mass or more, 0.005% by mass or more, 0.05% by mass or more, or 0.8% by mass or more, It can be 0.2% by mass or more, 0.4% by mass or more, 0.6% by mass or more, or 0.8% by mass or more. In one embodiment of the present invention, the content of the first water-soluble polymer is preferably 10 mass% or less, 8 mass% or less, 6 mass% or less, 4 mass% or less, 2 mass% or less, 1.9 mass% or less, 1.8% by mass or less, 1.7% by mass or less, 1.6% by mass or less, 1.5% by mass or less, 1.4% by mass or less, 1.3% by mass or less, 1.2% by mass or less, 1.1% by mass or less, 1.0% by mass or less, 0.9% by mass or less, 0.8% by mass or less, 0.7% by mass or less, 0.6% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, or 0.2% by mass or less. According to the embodiment of the present invention, even if the addition amount of the first water-soluble polymer is small, the effect of the present invention can be effectively exerted by the complementary and cooperative action of the second water-soluble polymer and the nonionic surfactant .

In one embodiment of the present invention, the first water-soluble polymer may be a homopolymer or a copolymer. In the case of a copolymer, its form may be any of a block copolymer, a random copolymer, a graft copolymer, and an alternating copolymer.

In one embodiment of the present invention, the aforementioned first water-soluble polymer is selected from polystyrene sulfonic acid, a (co)polymer whose structure part contains constituent units derived from polystyrene sulfonic acid, sulfonic acid and carboxylic acid At least one of the group of copolymers, sulfonated polysulfide and polyaniline. With this embodiment, the desired effect of the present invention can be efficiently exhibited.

(Second water-soluble polymer) In one embodiment of the present invention, the polishing composition includes a second water-soluble polymer that is different from the aforementioned first water-soluble polymer. Here, as an additional explanation, as long as the second water-soluble polymer is different from the aforementioned first water-soluble polymer, it may contain a group having a sulfonic acid group or a salt thereof, or a group having a carboxyl group or a salt thereof.

In one embodiment of the present invention, the aforementioned second water-soluble polymer includes a structural unit represented by the following formula (2):

X series are expressed as follows:

R ¹ to R ⁶ are each independently a hydrogen atom or -J, -J is a hydroxyl group, a sulfonic acid group or a group of its salt,

However, * represents the bonding position, R ⁷ and R ⁸ are each independently a hydrogen atom or -E, and -E is represented by the following formula:

However, * indicates a bonding position, and the aforementioned constituent unit includes at least one of -J and -E. With this embodiment, the desired effect of the present invention can be efficiently exhibited.

In one embodiment of the present invention, X is as follows:

At least one of R ¹ to R ⁴ is -J, and -J is a hydroxyl group, a sulfonic acid group or a salt thereof, or

Department is better.

In one embodiment of the present invention, X is as follows:

At least one of R ¹ ~R ⁴ is -J, -J is

Department is better.

In one embodiment of the present invention, X is as follows:

At least one of R ¹ , R ² , R ⁵ and R ⁶ is a hydrogen atom, R ⁸ is -E, and -E has the following formula:

Said system is better.

In one embodiment of the present invention, the weight average molecular weight of the second water-soluble polymer is preferably 5,000 or more, 10,000 or more, 15,000 or more, 20,000 or more, or 25,000 or more from the viewpoint of reducing the number of scratches or defects. . In one embodiment of the present invention, the weight average molecular weight of the second water-soluble polymer is preferably 60,000 or less, 50,000 or less, 40,000 or less, less than 30,000, 3.5 from the viewpoint of reducing the number of defects after polishing. 10,000 or less, 20,000 or less, 15,000 or less or 12,000 or less. According to the embodiment of the present invention, even if the weight average molecular weight of the second water-soluble polymer is relatively large, the effect of the present invention can be effectively exerted by the synergistic action with the first water-soluble polymer and the nonionic surfactant .

In one embodiment of the present invention, when the second water-soluble polymer is polyvinyl alcohol (PVA) or a (co)polymer whose structure part contains constituent units derived from polyvinyl alcohol (PVA), the weight average molecular weight is preferred The order is below 3000, below 2000, below 15000, and below 12000. In addition, when the weight average molecular weight of the second water-soluble polymer is 15,000 or less, considering reducing the number of SiN defects, it is preferable to use polypropylene glycol as a surfactant.

In one embodiment of the present invention, the content of the second water-soluble polymer relative to the total mass of the polishing composition is preferably 0.001 mass% or more, 0.005 mass% or more, 0.05 mass% or more, 0.08 mass% or more, 0.2% by mass or more, 0.4% by mass or more, 0.6% by mass or more, or 0.8% by mass or more. With this embodiment, the desired effect of the present invention can be effectively exhibited. In one embodiment of the present invention, the content of the second water-soluble polymer is preferably 10 mass% or less, 8 mass% or less, 6 mass% or less, 4 mass% or less, 2 mass% or less, 1.9 mass% or less, 1.8% by mass or less, 1.7% by mass or less, 1.6% by mass or less, 1.5% by mass or less, 1.4% by mass or less, 1.3% by mass or less, 1.2% by mass or less, or 1.1% by mass or less, can be 0.8% by mass or less, 0.6% by mass Or less, 0.4% by mass or less, or 0.3% by mass or less. According to the embodiment of the present invention, even if the addition amount of the second water-soluble polymer is small, the supplementary synergistic effect of the first water-soluble polymer and the nonionic surfactant can be achieved, especially for those containing oxygen-silicon bonds. The polishing object and the polishing object containing nitrogen-silicon bonds can effectively exhibit the effects of the present invention.

In one embodiment of the present invention, the second water-soluble polymer may be a homopolymer or a copolymer. In the case of a copolymer, its form may be any of a block copolymer, a random copolymer, a graft copolymer, and an alternating copolymer.

In one embodiment of the present invention, the aforementioned second water-soluble polymer is selected from polyvinyl alcohol (PVA), (co)polymers containing constituent units derived from polyvinyl alcohol in a part of the structure, and polyN-ethylene At least one of the group of (co)polymers containing a structural unit derived from poly-N-vinylacetamide in a part of the structure. With this embodiment, the desired effect of the present invention can be efficiently exhibited.

In one embodiment of the present invention, the degree of saponification of the aforementioned polyvinyl alcohol (PVA) or a (co)polymer containing constituent units derived from polyvinyl alcohol (PVA) in a part of the structure is preferably 90% or more.

In one embodiment of the present invention, at least one of the first water-soluble polymer and the second water-soluble polymer is a homopolymer. With this embodiment, it has the technical effect of reducing defects in the silicon nitride film.

In one embodiment of the present invention, the second water-soluble polymer includes a group having a sulfonic acid group or a salt thereof. Not only the first water-soluble polymer, but also the second water-soluble polymer contains a group having a sulfonic acid group or a salt thereof, and the first water-soluble polymer and the second water-soluble polymer Adsorbed to the surface of the object to be polished to increase the formation density of the protective film. This protective film serves as an adhesion prevention film that prevents the adhesion of defect-causing substances on the surface of the object to be polished. (In this manual, also referred to as "adhesion prevention film" "), it can reduce the number of defects.

[PH of polishing composition] In one embodiment of the present invention, the pH of the polishing composition is less than 9.0. In one embodiment of the present invention, the pH of the polishing composition is less than 8.0. In one embodiment of the present invention, the pH of the polishing composition is less than 7.0. In one embodiment of the present invention, the pH of the polishing composition is less than 6.0. In one embodiment of the present invention, the pH of the polishing composition is less than 5.0. In one embodiment of the present invention, the pH of the polishing composition does not reach 4.5. In one embodiment of the present invention, the pH of the polishing composition does not reach 4.0. In one embodiment of the present invention, the polishing composition has a pH of 3.9 or less, a pH of 3.7 or less, a pH of 3.5 or less, or a pH of 3.3 or less. In one embodiment of the present invention, the pH of the polishing composition exceeds 1.0. In one embodiment of the present invention, the pH of the polishing composition exceeds 1.5. In one embodiment of the present invention, the pH of the polishing composition exceeds 2.0. In one embodiment of the present invention, the polishing composition has a pH of 2.1 or higher. In one embodiment of the present invention, the pH of the polishing composition is 2.3 or more. In one embodiment of the present invention, the pH of the polishing composition is 2.5 or more. In one embodiment of the present invention, the pH of the polishing composition is 2.7 or higher. In one embodiment of the present invention, the pH of the polishing composition exceeds 2.0 and does not reach 5.0, and further exceeds 2.0 and does not reach 4.0. With this embodiment, the desired effect of the present invention can be effectively exhibited.

In one embodiment of the present invention, the polishing composition contains a pH adjuster. As the pH adjuster, conventional acids, bases, or salts thereof can be used. Specific examples of acids that can be used as pH adjusters include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, boric acid, carbonic acid, hypophosphorous acid, phosphorous acid, and phosphoric acid, or formic acid, acetic acid, propionic acid, butyl Acid, valeric acid, 2-methylbutanoic acid, hexanoic acid, 3,3-dimethylbutanoic acid, 2-ethylbutanoic acid, 4-methylpentanoic acid, heptanoic acid, 2-methylhexanoic acid, caprylic 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, lactic acid, diglycolic acid, 2-furancarboxylic acid, 2,5-furandicarboxylic acid, 3-furancarboxylic acid, 2-tetrahydrofurancarboxylic acid, methoxyacetic acid, methoxy Organic acids such as phenyl acetic acid and phenoxy acetic acid. However, in the present invention, one of the characteristics of the polishing composition is that it contains a first water-soluble polymer having a sulfonic acid group or its salt group or a carboxylic acid or its salt group. Therefore, according to one embodiment of the present invention, the acid used as the pH adjuster is only the first water-soluble polymer. According to this embodiment, the charge interaction can promote the formation of a protective film of the first water-soluble polymer on the surface of the object to be polished. The protective film serves as prevention of easy peeling of the substance that causes defects to adhere to the surface of the object to be polished. The function of the adhesion film can reduce the number of defects.

In addition, when the aforementioned second water-soluble polymer contains a group having a sulfonic acid group or a salt thereof, the acid as a pH adjuster is only the first water-soluble polymer and the second water-soluble polymer. According to this embodiment, the charge interaction can promote the formation of a protective film between the first water-soluble polymer and the second water-soluble polymer on the surface of the object to be polished. The surface of the object is easily peeled off to prevent the function of the adhesion film, so the number of defects can be reduced. In the embodiment of the present invention, these effects can be particularly exerted on Si-based materials (specifically, all materials containing silicon such as silicon oxide, polysilicon, silicon nitride, etc.) as objects to be polished.

Examples of bases that can be used as pH adjusters include amines such as aliphatic amines and aromatic amines, ammonium solutions, organic bases such as quaternary ammonium hydroxide, hydroxides of alkali metals such as potassium hydroxide, and group 2 Elemental hydroxide, histidine amino acid, ammonia, etc. The pH adjuster can be used alone or in combination of two or more kinds. The addition amount of the pH adjuster is not particularly limited, as long as the polishing composition is appropriately adjusted to the desired pH.

(Non-ionic surfactant) In one embodiment of the present invention, the polishing composition contains a nonionic surfactant.

In one embodiment of the present invention, the aforementioned nonionic surfactant is a polymer, and its weight average molecular weight is preferably 50 or more, more preferably 100 or more, and even more preferably 200 or more. With this embodiment, the desired effect of the present invention can be effectively exhibited. In one embodiment of the present invention, the aforementioned nonionic surfactant is a polymer, and its weight average molecular weight is preferably 10,000 or less, more preferably 5,000 or less, and even more preferably 1,000 or less. With this embodiment, the desired effect of the present invention can be effectively exhibited.

In one embodiment of the present invention, the aforementioned nonionic surfactant includes a glycerin structure and an alkyl group having 4 or more carbon atoms. In one embodiment of the present invention, the aforementioned nonionic surfactant includes a glycerin structure and an alkyl group having 4 or more carbon atoms. In one embodiment of the present invention, the carbon number of the alkyl group is preferably 6 or more, more preferably 8 or more, and still more preferably 10 or more. With this embodiment, it can be selectively adsorbed on the surface of the Si-based material, and the desired effect of the present invention can be effectively exhibited. In one embodiment of the present invention, the carbon number of the alkyl group is preferably 18 or less, more preferably 16 or less, and still more preferably 14 or less. With this embodiment, it has the technical effect of being adsorbed on the surface of the Si-based material and then easily detached later (for example, during cleaning or cleaning).

In one embodiment of the present invention, the first-order hydroxyl density of the nonionic surfactant is 50% or more. More clearly, the non-ionic surfactants (for example, polyglycerin surfactants) have 50% or more of the primary hydroxyl groups in all the hydroxyl groups. When the first-order hydroxyl density of the aforementioned nonionic surfactant is less than 50%, it may be difficult to adsorb on the surface of the Si-based material. According to this embodiment, the first-grade hydroxyl density is preferably 60% or more, more preferably 65% or more, still more preferably 70% or more, and still more preferably 75% or more. With this embodiment, it has the technical effect of being easily adsorbed on the surface of the Si-based material. According to this embodiment, the first-grade hydroxyl density is preferably 99% or less, more preferably 95% or less, still more preferably 92% or less, and still more preferably 90% or less.

The method of adjusting the primary hydroxyl density of the nonionic surfactant to the above-mentioned value is not particularly limited, as long as the method disclosed in, for example, Japanese Patent Application Laid-Open No. 2006-346526 is applied. In this publication, although the polyglycerol lauryl ester is disclosed, the knowledge that the density of the primary hydroxyl group is adjusted to the above-mentioned value can also be applied to other polyol-based nonionic surfactants (for example, polyglyceryl lauryl ether). In addition, the ratio of the first-order hydroxyl group to the second-order hydroxyl group can be obtained by spectral analysis in the nuclear magnetic resonance device disclosed in [0018] of the document. Also, refer to Japan Special Publications with appropriate combinations The techniques disclosed in 2013-181169, JP 2014-074175, 2019-026822, and 2011-007588 adjust the first-level hydroxyl density to the above-mentioned value.

In one embodiment of the present invention, the aforementioned nonionic surfactant may not be the polyglyceryl alkyl ether containing a glycerin structure and an alkyl group with a carbon number of 4 or more as described above, but may suitably be polypropylene glycol, polyglycerin, polyglycerin Glycerol alkyl esters, dextrin, dextrin derivatives, etc. are particularly suitable as polypropylene glycol.

In one embodiment of the present invention, the aforementioned nonionic surfactant is a polyglycerol alkyl ether, and its weight average molecular weight is 500 or more. If a polyglycerol alkyl ether having a weight average molecular weight of less than 500 is used, there is a possibility that a film preventing adhesion of the defect-causing substance cannot be formed on the surface of the polishing object. According to this embodiment, the weight average molecular weight is preferably 750 or higher, more preferably 1250 or higher, and still more preferably 1500 or higher. With this embodiment, it has the technical effect of accelerating the adsorption speed of the defect-causing substance during the formation of the adhesion prevention film, and easily detaching during cleaning or cleaning.

According to this embodiment, the weight average molecular weight can be 2500 or less. According to this embodiment, there is a technical effect that it can be adsorbed on the surface of the object to be polished to form an adhesion preventing film of the substance causing defects.

In one embodiment of the present invention, polypropylene glycol may be mono-alcohol type, diol type, triol type, or a mixture of these. Among them, the diol type is preferred. The glycol type is also used in the examples.

In addition, if polyethylene glycol (PEG) is used instead of polypropylene glycol (PPG), the surface roughness may deteriorate.

In one embodiment of the present invention, the weight average molecular weight of the aforementioned polypropylene glycol is preferably 200 or more, more preferably 300 or more, and still more preferably 400 or more. According to this embodiment, the expected effect of the present invention can be effectively exhibited. According to an embodiment of the present invention, the weight average molecular weight of the aforementioned polypropylene glycol is preferably 10,000 or less, more preferably 5,000 or less, and even more preferably 2,000 or less. According to this embodiment, the solubility of polypropylene glycol is improved, and the expected effect of the present invention can be effectively exhibited.

In one embodiment of the present invention, the content of the nonionic surfactant relative to the total mass of the polishing composition is preferably 0.001 mass% or more, 0.005 mass% or more, 0.05 mass% or more, 0.08 mass% or more, 0.2% by mass or more, 0.4% by mass or more, 0.6% by mass or more, or 0.8% by mass or more.

In one embodiment of the present invention, the content of the nonionic surfactant is preferably 10% by mass or less, 8% by mass or less, 6% by mass or less, 4% by mass or less, 2% by mass or less, 1.9% by mass or less, 1.8% by mass or less, 1.7% by mass or less, 1.6% by mass or less, 1.5% by mass or less, 1.4% by mass or less, 1.3% by mass or less, 1.2% by mass or less, or 1.1% by mass or less. In this embodiment, when the aforementioned nonionic surfactant is a polyglycerol alkyl ether, the polyglycerol alkyl ether is 0.6% by mass or more or 0.8% by mass or more. Thereby, the number of defects in polishing objects containing oxygen-silicon bonds or polishing objects containing silicon-silicon bonds can be further reduced. In addition, the above description applies to the upper limit.

In one embodiment of the present invention, the weight average molecular weights of the first water-soluble polymer, the second water-soluble polymer, and the nonionic surfactant are respectively 3000 or more; 5000 or more; 200, 300, 400, or 500 the above. Since any one of the three compounds contained in the polishing composition of the present embodiment is a polymer having a molecular weight of the above-mentioned lower limit, it has an anti-adhesion film that is easy to form a defect-causing substance on the object to be polished. The technical effect of the desired effect of the invention. In this aspect, the above description applies to the upper limit of the weight average molecular weight of the first water-soluble polymer, the second water-soluble polymer, and the nonionic surfactant.

In one embodiment of the present invention, the nonionic surfactant is not an amine nonionic surfactant.

(Aqueous carrier) The polishing composition of an embodiment of the present invention usually contains an aqueous carrier. The aqueous carrier has the function of dispersing or dissolving each component. More preferably, the aqueous carrier is only water. In addition, the aqueous carrier may be a mixed solvent of water and an organic solvent in order to disperse or dissolve each component.

From the viewpoint of hindering the contamination of the object to be polished or the effect of other components, the water is preferably water that contains as little impurities as possible. For example, water in which the total content of transition metal ions is 100 ppb or less is preferable. Here, the purity of water can be improved by operations such as removal of impurity ions using an ion exchange resin, removal of foreign substances using a filter, and distillation. Specifically, as the water, for example, deionized water (ion exchange water), pure water, ultrapure water, distilled water, etc. are preferably used.

(Other additives) The polishing composition of one embodiment of the present invention may contain other additives in any proportion as needed within a range that does not impair the effects of the present invention. Examples of other additives include preservatives, dissolved gases, reducing agents, and oxidizing agents.

In one embodiment of the present invention, the polishing composition does not contain at least one selected from the group consisting of polyethylene glycol, polyoxyethylene nonylphenyl ether, polyglycerol, and polyoxyethylene lauryl sulfate.

In one embodiment of the present invention, the polishing composition does not contain polyvinyl acetal.

In one embodiment of the present invention, the polishing composition does not contain a polymer containing a structural unit derived from hydroxyethyl acrylamide.

In one embodiment of the present invention, the polishing composition does not contain a modified polyvinyl alcohol polymer containing an alkoxylate group.

In one embodiment of the present invention, the polishing composition does not contain a polymer containing a structural unit derived from (meth)acrylamide. [Example]

The present invention will be further described in detail using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following embodiments. In addition, unless otherwise specified, "%" and "parts" mean "mass %" and "parts by mass", respectively. In addition, in the following examples, unless otherwise stated, the operation is performed under the conditions of room temperature (25° C.)/relative humidity of 40 to 50% RH.

[Preparation of polishing composition] As shown in Table 1, the abrasive particles (sulfonic acid fixed colloidal silica; average primary particle size: 35nm, average secondary particle size: 70nm, D90/D10: 1.7, aspect ratio: 1.2) and the first water-soluble The polymer, the second water-soluble polymer, the surfactant, and the liquid carrier (pure water) have the composition and pH shown in Table 1. For some of the examples and comparative examples, ammonia was appropriately added and stirred and mixed to prepare each grinding Use the composition (mixing temperature: about 25°C, mixing time: about 10 minutes). In addition, the polyglyceryl lauryl ether and polyglyceryl lauryl ester used in the examples and comparative examples have first-grade hydroxyl density of 75%-85%. In addition, the saponification degrees of polyvinyl alcohol and sulfonic acid-modified polyvinyl alcohol used in the examples and comparative examples are 100% and 99%, respectively.

[Average primary particle size of abrasive grains] The average primary particle size of the abrasive grains is calculated from the specific surface area of the abrasive grains and the density of the abrasive grains measured by the BET method using "Flow Sorb II2300" manufactured by MicroMetrics.

[Average secondary particle size of abrasive grains] The average secondary particle size of the abrasive grains was calculated by the dynamic light scattering method measured using "UPA-UT151" manufactured by Microtrac.

[Aspect ratio of abrasive grains] As the aspect ratio of the abrasive grains, 300 pieces of abrasive grain images measured by FE-SEM were randomly selected, and the average value of the aspect ratio (long diameter/short diameter) was measured.

[PH of polishing composition] The pH of the polishing composition uses a glass electrode type hydrogen ion concentration indicator (manufactured by Horiba Manufacturing Co., Ltd., model: F-23), and a standard buffer (phthalate pH buffer pH: 4.01 (25 ℃), neutral phosphoric acid pH buffer solution pH: 6.86 (25℃), carbonate pH buffer solution pH: 10.01 (25℃)) After 3-point calibration, the glass electrode is put into the polishing composition, and the measurement process is 2 It is determined by the value after stable for more than minutes. The results are shown in Table 1.

[Polishing test] In each example and comparative example, a silicon oxide film with a thickness of 1000Å, a silicon nitride film with a thickness of 1000Å, and a polysilicon film with a thickness of 1000Å will be formed on the surface of a silicon wafer (300mm, blank wafer) as the polishing Objects (represented as SiO ₂ , SiN, and Poly-Si in the table). The silicon oxide film is derived from TEOS (tetraethyl orthosilicate). Each polishing object was cut into a coupon of a wafer of 60 mm×60 mm as a test piece, and polished under the following conditions.

(Grinding equipment and conditions) Grinding device: Grinding machine EJ-380IN-CH made by Engis, Japan Grinding pressure: 1.5psi(=10.3kPa) Polishing pad: Hard polyurethane polishing pad IC1010 made by Nitta Haas Co., Ltd. Rotation speed of grinding platen: 83rpm Carrier rotation number: 77rpm Supply of polishing composition: outflow from source Supply volume of polishing composition: 200ml/min Grinding time: 20 seconds

(Measurement of grinding speed) The thickness (film thickness) of the test piece before and after polishing was measured with an optical film thickness measuring device (ASET-f5x: manufactured by KLA TENCOR). Calculate the difference between the thickness (film thickness) of the test piece before and after polishing, divide it by the polishing time, and calculate the polishing speed (Å/min) by sorting the unit. The results are shown in the following table. Also, 1Å=0.1 nm.

(Determination of the number of defects) For the polished test piece, the number of defects over 0.13μm is measured. The number of defects was measured using the wafer defect inspection device SP-2 manufactured by KLA TENCOR. The measurement is performed on the part of the polished test piece except for the part with a width of 5 mm from the outer peripheral end of one side (when the outer peripheral end is set to 0 mm, the part from a width of 0 mm to a width of 5 mm) is measured. The smaller the number of defects, the smaller the number of surface scratches, roughness, and residues, and the smaller the surface disorder.

(Determination of surface roughness) For the polished test piece, the surface roughness (Ra) was measured using a scanning probe microscope (SPM). Also, as Ra, NANO-NAV12 manufactured by Hitachi High-Tech Co., Ltd. is used. The cantilever system uses SI-DF40P2. The measurement was performed 3 times at a scanning frequency of 0.86 Hz, X: 512 pt, and Y: 512 pt, and the average value thereof was used as the surface roughness (Ra). In addition, the scanning range of SPM is a square area of "2μm×2μm".

Claims (19)

A polishing composition, which comprises: Abrasive particles made by immobilizing organic acid on the surface, Contains the first water-soluble polymer having a sulfonic acid group or its salt group or a carboxyl group or its salt group, A second water-soluble polymer that is different from the aforementioned first water-soluble polymer, Nonionic surfactants, and Aqueous carrier, And it is used for polishing objects. For example, the polishing composition of claim 1 has a pH of less than 9.0. For example, the polishing composition of claim 2 has a pH of less than 7.0. For example, the polishing composition of claim 3 has a pH of less than 5.0. The polishing composition according to any one of claims 1 to 4, wherein the content of the aforementioned abrasive particles exceeds 0.01% by mass. The polishing composition according to any one of claims 1 to 5, wherein the secondary average particle size of the aforementioned abrasive grains is less than 100 nm. The polishing composition according to any one of claims 1 to 6, wherein at least one of the first water-soluble polymer and the second water-soluble polymer is a homopolymer. The polishing composition according to any one of claims 1 to 7, wherein the first water-soluble polymer includes a structural unit represented by the following formula (1):

R ⁹ is a hydrogen atom or a methyl group, R ¹⁰ and R ¹¹ are each independently a hydrogen atom, -COOR ¹² or -G, but R ¹⁰ and R ^{11 are} not a hydrogen atom at the same time, -G is a sulfonic acid group,

, However, * represents the bonding position, R ¹² , R ¹³ and R ¹⁵ are each independently a hydrogen atom, an alkyl group with 1 to 12 carbons, a hydroxyalkyl group with 1 to 12 carbons, or a relative cation. R ¹⁴ is a divalent base. The polishing composition according to any one of claims 1 to 8, wherein the second water-soluble polymer includes a structural unit represented by the following formula (2):

X series are expressed as follows:

R ¹ to R ⁶ are each independently a hydrogen atom or -J, -J is a hydroxyl group, a sulfonic acid group or a group of its salt,

However, * represents the bonding position, R ⁷ and R ⁸ are each independently a hydrogen atom or -E, and -E is represented by the following formula:

However, * indicates a bonding position, and the aforementioned constituent unit includes at least one of -J and -E. The polishing composition according to any one of claims 1 to 9, wherein the first water-soluble polymer is selected from polystyrene sulfonic acid, and a part of the structure includes a constituent unit derived from polystyrene sulfonic acid At least one of (co)polymers, copolymers of sulfonic acid and carboxylic acid, sulfonated polysulfonate, and polyaniline acid. The polishing composition according to any one of claims 1 to 10, wherein the second water-soluble polymer is selected from polyvinyl alcohol (PVA), and a part of the structure includes a composition derived from polyvinyl alcohol (PVA) At least 1 of a group of (co)polymers of units, poly-N-vinylacetamide, and (co)polymers containing constituent units derived from poly-N-vinylacetamide in a part of the structure Kind. Such as the polishing composition of claim 11, wherein the aforementioned polyvinyl alcohol (PVA) or a (co)polymer containing a constituent unit derived from polyvinyl alcohol (PVA) in a part of the structure has a saponification degree of 90% or more. The polishing composition according to claim 1, wherein the second water-soluble polymer includes a group having a sulfonic acid group or a salt thereof. The polishing composition according to any one of claims 1 to 13, wherein the aforementioned nonionic surfactant is polypropylene glycol. Such as the polishing composition of any one of claims 1 to 14, which is used for preliminary polishing. The polishing composition according to any one of claims 1 to 15, wherein the polishing object includes a silicon-silicon bond, a nitrogen-silicon bond, or an oxygen-silicon bond. The polishing composition according to any one of claims 1 to 16, wherein the weight average molecular weights of the first water-soluble polymer, the second water-soluble polymer and the nonionic surfactant are respectively 3000 or more and 5000 Above and above 200. A method for polishing an object to be polished, which comprises using the polishing composition according to any one of claims 1 to 17 to polish an object to be polished. A manufacturing process of a semiconductor device, which includes a preliminary polishing step, a bulk polishing step, and a polishing polishing step, and using the polishing composition according to any one of claims 1 to 18 as the polishing in the preliminary polishing step Composition.