Surface treatment composition, surface treatment method, and method for manufacturing semiconductor substrate

Abstract

To provide means which can sufficiently remove residual residue on the surface of polished abrasive objects.SOLUTION: This buffer is a surface treatment composition containing the following (A)-(C) components and having a pH greater than 7.0, (A) component: a quaternary nitrogen-containing onium salt compound having at least one of a linear or branched-chain alkyl group with a carbon number of 7 or more and a linear or branched-chain alkenyl group with a carbon number of 7 or more, (B) component: nonionic polymer, (C) component: formula: A-COO-NH4+.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a surface treatment composition, a surface treatment method, and a method for producing a semiconductor substrate. [Background technology]

[0002] In recent years, with the trend toward multilayer wiring on semiconductor substrate surfaces, so-called chemical mechanical polishing (CMP) technology, which physically polishes and flattens semiconductor substrates, has come to be used in device manufacturing. CMP is a method of flattening the surface of an object to be polished (workpiece) such as a semiconductor substrate using a polishing composition (slurry) containing abrasive grains such as silica, alumina, or ceria, an anticorrosive agent, a surfactant, etc. The object to be polished (workpiece) is a wiring or plug made of silicon, polysilicon, silicon oxide, silicon nitride, metal, etc.

[0003] After the CMP process, a large amount of impurities (also called foreign matter or residue) remain on the surface of a semiconductor substrate. The impurities include organic matter such as abrasive grains, metals, anticorrosives, and surfactants derived from the polishing composition used in CMP, silicon-containing materials to be polished, silicon-containing materials and metals generated by polishing metal wiring and plugs, and organic matter such as pad debris generated from various pads.

[0004] Contamination of the semiconductor substrate surface by these impurities can adversely affect the electrical characteristics of the semiconductor and reduce device reliability. Therefore, it is desirable to introduce a cleaning process after the CMP process to remove these impurities from the semiconductor substrate surface.

[0005] As such a cleaning composition, for example, Patent Document 1 discloses a rinse composition containing at least one compound selected from the group consisting of quaternary polyammonium salts, quaternary ammonium salts having 6 or more carbon atoms, and polymers having a specific structure, and a water-soluble polymer. Patent Document 1 further discloses that the rinse composition can remove abrasives and the like remaining on a polishing pad and reduce haze on the substrate surface in both preliminary polishing and finish polishing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2020-203980 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the technique of Patent Document 1 has a problem in that foreign matter (residue) cannot be sufficiently removed when cleaning a polished object.

[0008] Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a means capable of sufficiently removing residue remaining on the surface of a polished object. [Means for solving the problem]

[0009] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result have found that the above-mentioned problems can be solved by an alkaline surface treatment composition containing a quaternary nitrogen-containing onium salt compound having a structural unit with a specific structure, a nonionic polymer, and an ammonium monocarboxylate that acts as a buffer, thereby completing the present invention.

[0010] That is, the above object is achieved by a surface treatment composition containing the following components (A) to (C) and having a pH of more than 7.0: Component (A): A quaternary nitrogen-containing onium salt compound having at least one of a linear or branched alkyl group having 7 or more carbon atoms and a linear or branched alkenyl group having 7 or more carbon atoms. (B) Component: Nonionic polymer (C) Component: Formula: A-COO - NH4 + (A is an alkyl group or a phenyl group having 1 to 10 carbon atoms). [Effects of the Invention]

[0011] According to the present invention, a means for sufficiently removing residues remaining on the surface of a polished object can be provided, and the etching rate for a polished object containing polycrystalline silicon can be kept low. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention provides a surface treatment composition comprising the following components (A) to (C), and having a pH of greater than 7.0: Component (A): A quaternary nitrogen-containing onium salt compound having at least one of a linear or branched alkyl group having 7 or more carbon atoms and a linear or branched alkenyl group having 7 or more carbon atoms. (B) Component: Nonionic polymer (C) Component: Formula: A-COO - NH4 + (A is an alkyl group or a phenyl group having 1 to 10 carbon atoms).

[0013] The surface treatment composition of the present invention can sufficiently remove residues (e.g., abrasive grain residues, organic residues) remaining on the surface of a polished object (especially a polished silicon nitride substrate), and can also reduce the etching rate for polished objects containing polycrystalline silicon.

[0014] The inventors speculate that the mechanism by which such a configuration can remove residues on the surface of a polished object and further reduce the etching rate for a polished object containing polycrystalline silicon is as follows.

[0015] The surface treatment composition of the present invention contains specific components (A) to (C). Of these, component (A) exhibits no pKa in water and is positively charged. Therefore, regardless of pH, the zeta potential of the polished object (e.g., polished silicon nitride substrate), abrasive grain residue, organic residue (e.g., pad debris, polymers), etc. is controlled to a positive value, suppressing or preventing the adsorption of residue to the polished object due to electrostatic repulsion. Furthermore, component (B) improves the wettability of the polished surface of the object, facilitating the formation of a water molecule film on the surface. Therefore, not only is adhesion of hydrophobic organic residue to the surface of the polished object suppressed, but re-adhesion of organic residue is also prevented. Therefore, the surface treatment composition of the present invention can efficiently remove residue.

[0016] In addition, before the cleaning process (surface treatment, rinse polishing), the surface of a semiconductor substrate is typically polished with an alkaline slurry (polishing slurry) in the CMP process. When such a polished semiconductor substrate (polished object) is cleaned (rinse polished) with a surface treatment composition, the pH of the surface treatment composition increases due to the alkaline polishing slurry. As a result, the zeta potential of the residue changes, inducing adhesion of the residue (especially abrasive residue) and increasing the etching rate for the polished object, including polycrystalline silicon. However, the presence of component (C) suppresses the increase in pH of the surface treatment composition during cleaning (rinse polishing). This keeps the zeta potential of the polished object (especially a polished silicon nitride substrate), abrasive residue, organic residue (e.g., pad debris, polymers), etc. at an optimal (positive) state, suppressing or preventing the adsorption of the residue to the polished object due to electrostatic repulsion. Therefore, the surface treatment composition of the present invention can efficiently remove residue. In addition, under alkaline conditions, the etching rate for polished objects containing polycrystalline silicon changes significantly. However, due to the presence of component (C), the pH of the surface treatment composition changes little during cleaning (rinse polishing) (it is less susceptible to the effects of alkaline polishing slurries). Therefore, the etching rate for polished objects containing polycrystalline silicon can be kept low.

[0017] The above mechanism is based on speculation, and the present invention is not limited to the above mechanism in any way.

[0018] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to only the following embodiments. In this specification, unless otherwise specified, operations and measurements of physical properties are performed under conditions of room temperature (20°C or higher and 25°C or lower) and relative humidity of 40% RH or higher and 50% RH or lower. Furthermore, "X and / or Y" means that X, Y are included individually and in combination.

[0019] [Residue] In this specification, the term "residue" refers to foreign matter adhering to the surface of the polished object. Examples of the residue are not particularly limited, but include, for example, residue derived from the object to be polished, organic residue described below, particle residue derived from the abrasive grains contained in the polishing composition (abrasive grain residue), residue composed of components other than particle residue and organic residue, mixture of particle residue and organic residue, and other residues.

[0020] The total number of residues refers to the total number of all residues, regardless of type. The total number of residues can be measured using a wafer defect inspection device. The total number of residues refers to the total number of specific residues. Details of the method for measuring the number of residues will be described in the Examples below.

[0021] In this specification, organic residue refers to components of foreign matter adhering to the surface of a polished object (object to be surface-treated) that are composed of organic substances such as organic low molecular weight compounds and high molecular weight compounds, organic salts, etc.

[0022] Examples of organic residues adhering to the polished object include pad dust generated from the pad used in the polishing step or rinse polishing step described below, or components derived from additives contained in the polishing composition used in the polishing step or the surface treatment composition used in the rinse polishing step.

[0023] Since organic residues and other foreign matter differ significantly in color and shape, whether a foreign matter is organic residue can be determined visually by SEM observation. Furthermore, whether a foreign matter is organic residue can also be determined, if necessary, by elemental analysis using an energy dispersive X-ray analyzer (EDX). The number of organic residues can be measured using a wafer defect inspection system and SEM or EDX elemental analysis.

[0024] [Polished object] In this specification, the term "polished object" refers to an object that has been polished in a polishing step. The polishing step is not particularly limited, but is preferably a CMP step.

[0025] The material contained in the object to be polished according to the present invention is not particularly limited, and examples thereof include carbon-containing silicon such as silicon oxide, silicon nitride (SiN), and silicon carbonitride (SiCN), polycrystalline silicon (polysilicon), non-crystalline silicon (amorphous silicon), silicon materials doped with impurities, elemental metals, alloys, metal nitrides, and compound semiconductors such as SiGe. Of these, it is preferable that at least one of silicon nitride, silicon oxide, and polysilicon is contained.

[0026] Examples of films containing silicon oxide include TEOS (Tetraethyl Orthosilicate) type silicon oxide films (hereinafter simply referred to as "TEOS films") produced using tetraethyl orthosilicate as a precursor, HDP (High Density Plasma) films, USG (Undoped Silicate Glass) films, PSG (Phosphorus Silicate Glass) films, BPSG (Boron-Phospho Silicate Glass) films, RTO (Rapid Thermal Oxidation) films, etc. The material contained in the object to be polished may be one type alone or a combination of two or more types.

[0027] The polished object is preferably a polished semiconductor substrate, more preferably a semiconductor substrate after a CMP process, because residues can cause damage to semiconductor devices, and therefore, when the polished object is a polished semiconductor substrate, the cleaning process for the semiconductor substrate must be capable of removing as many residues as possible.

[0028] Furthermore, the surface treatment composition according to one embodiment of the present invention can reduce residues on the surface of a polished object containing both a hydrophilic material and a hydrophobic material. Here, the hydrophilic material refers to a material having a contact angle with water of less than 50°, and the hydrophobic material refers to a material having a contact angle with water of 50° or more. The contact angle with water is a value measured using a contact angle meter, DropMaster (DMo-501), manufactured by Kyowa Interface Science Co., Ltd.

[0029] Specific examples of hydrophilic materials include silicon oxide, silicon nitride, silicon oxynitride, tungsten, titanium nitride, tantalum nitride, and boron-containing silicon. These hydrophilic materials may be used alone or in combination of two or more. According to a preferred embodiment of the present invention, the hydrophilic material is silicon oxide. According to a preferred embodiment of the present invention, the hydrophilic material is silicon nitride. Specific examples of hydrophobic materials include polycrystalline silicon, single-crystalline silicon, amorphous silicon, and carbon-containing silicon. These hydrophobic materials may be used alone or in combination of two or more. According to a preferred embodiment of the present invention, the hydrophobic material is polycrystalline silicon.

[0030] That is, according to a preferred embodiment of the present invention, the hydrophilic material is silicon oxide and the hydrophobic material is polycrystalline silicon. Also, according to a preferred embodiment of the present invention, the hydrophilic material is silicon nitride and the hydrophobic material is polycrystalline silicon.

[0031] [Surface treatment composition] The surface treatment composition according to the present invention comprises the following components (A) to (C) and has a pH of greater than 7.0: Component (A): A quaternary nitrogen-containing onium salt compound having at least one of a linear or branched alkyl group having 7 or more carbon atoms and a linear or branched alkenyl group having 7 or more carbon atoms. (B) Component: Nonionic polymer (C) Component: Formula: A-COO - NH4 +(A is an alkyl group or a phenyl group having 1 to 10 carbon atoms).

[0032] The surface treatment composition according to the present invention is used to reduce residues on the surface of a polished object, and to suppress the etching rate of a polished object containing polycrystalline silicon.

[0033] In this specification, the quaternary nitrogen-containing onium salt compound as component (A) is also referred to simply as the "quaternary nitrogen-containing onium salt compound according to the present invention" or "quaternary nitrogen-containing onium salt compound." The nonionic polymer as component (B) is also referred to simply as the "nonionic polymer according to the present invention" or "nonionic polymer." The compound of the formula: A-COO as component (C) is also referred to simply as the "quaternary nitrogen-containing onium salt compound according to the present invention." - NH4 + (A is an alkyl group or a phenyl group having from 1 to 10 carbon atoms) is also referred to simply as "the buffer according to the present invention" or "the ammonium monocarboxylate according to the present invention" or "ammonium monocarboxylate."

[0034] <Component (A)> The surface treatment composition of the present invention contains, as component (A), a quaternary nitrogen-containing onium salt compound having at least one of a linear or branched alkyl group having 7 or more carbon atoms and a linear or branched alkenyl group having 7 or more carbon atoms.

[0035] The quaternary nitrogen-containing onium salt compound is composed of a quaternary nitrogen-containing onium cation having the above-mentioned specific substituent and an anion (counter anion).

[0036] The quaternary nitrogen-containing onium cation contains at least one of a linear or branched alkyl group having 7 or more carbon atoms (hereinafter sometimes simply referred to as an "alkyl group") and a linear or branched alkenyl group having 7 or more carbon atoms (hereinafter sometimes simply referred to as an "alkenyl group"). The quaternary nitrogen-containing onium cation may contain two or more such alkyl groups and / or alkenyl groups, and when it contains two or more of these substituents, these substituents may be the same or different.

[0037] A preferred form of the quaternary nitrogen-containing onium cation is a quaternary ammonium cation in which at least one of the alkyl or alkenyl groups described above is bonded to a nitrogen atom. More specifically, the quaternary ammonium cation is preferably represented by the following formula (I):

[0038] [ka]

[0039] In the above formula (I), R is a linear or branched alkyl group having 7 or more carbon atoms or a linear or branched alkenyl group having 7 or more carbon atoms, R' is an organic group, and n is an integer of 1 to 4. However, when n is 2 or more, multiple R's may be the same or different. Also, when n is 2 or less, multiple R's may be the same or different.

[0040] In the above formula (I), specific examples of the linear or branched alkyl group having 7 or more carbon atoms as R include linear alkyl groups such as n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, lauryl group (n-dodecyl group), n-tridecyl group, myristyl group (n-tetradecyl group), n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, stearyl group (n-octadecyl group), n-nonadecyl group, and n-icosyl group; branched alkyl groups such as a 1-methylhexyl group, a 2-ethylhexyl group, a 4-methylhexyl group, a 5-methylhexyl group, a 1-ethylpentyl group, a 1-propylbutyl group, a 1-ethyl-1,2-dimethylpropyl group, a 1-methylheptyl group, a 1-ethylhexyl group, a 1-propylpentyl group, a 2-propylpentyl group, a 1-methyloctyl group, a 2,2-dimethylheptyl group, a 1-ethylheptyl group, a 3-ethylheptyl group, a 1-propylhexyl group, a 1-butylpentyl group, a 1-methylnonyl group, a 1-ethyloctyl group, a 1-propylheptyl group, and a 1-butylhexyl group;

[0041] Specific examples of the straight-chain or branched-chain alkenyl group having 7 or more carbon atoms represented by R include a 1-heptenyl group, a 2-heptenyl group, a 5-heptenyl group, a 1-octenyl group, a 3-octenyl group, a 5-octenyl group, a 1-nonenyl group, a 1-decenyl group, a 1-undecenyl group, a 1-dodecenyl group, a 1-tridecenyl group, a 1-tetradecenyl group, a 1-pentadecenyl group, a 1-hexadecenyl group, a 1-heptadecenyl group, an o- Examples of such straight-chain alkenyl groups include a octadecenyl group (for example, an oleyl group ((Z)-octadec-9-en-1-yl group)), a linoleoyl group ((9Z,12Z)-octadeca-9,12-dienoyl group), an α-linolenoyl group ((9Z,12Z,15Z)-octadeca-9,12,15-trienoyl group), and a γ-linolenoyl group ((6Z,9Z,12Z)-octadeca-6,9,12-trienoyl group).

[0042] In particular, it is preferable that the alkyl group and the alkenyl group are both straight-chain.

[0043] The upper limit of the carbon number of the alkyl group and the alkenyl group is not particularly limited, but from the viewpoint of reducing organic residues, it is preferably 30 or less, more preferably 20 or less, even more preferably 15 or less, and particularly preferably 14 or less. On the other hand, the lower limit of the carbon number is 7, but it is preferably 8 or more, more preferably 9 or more, and particularly preferably 10 or more. Therefore, as an example, the number of carbon atoms in the alkyl group or alkenyl group contained in the quaternary ammonium cation is preferably 7 to 30, more preferably 8 to 20, even more preferably 9 to 15, and particularly preferably 10 to 14. Furthermore, the carbon number is most preferably 12.

[0044] The alkyl group and the alkenyl group may be substituted or unsubstituted. Unless otherwise specified, the term "substituted" used herein refers to substitution with an alkyl group, a cycloalkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an alkoxy group, a cycloalkoxy group, an alkenyl group, an alkynyl group, an amino group, an aryl group, an aryloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group, an alkoxycarbonyl group, an aryloxycarbonyl group, a hydroxy group (-OH), a carboxy group (-COOH), a thiol group (-SH), a cyano group (-CN), or the like. When a group is substituted, the form of substitution that would be included in the definition before the substituted structure is further substituted is excluded. For example, when the substituent is an alkyl group, the alkyl group as the substituent is not further substituted with an alkyl group. However, from the viewpoint of minimizing the inclusion of impurities, the alkyl group and the alkenyl group contained in the quaternary ammonium cation are preferably unsubstituted.

[0045] In particular, in the above formula (I), R is preferably a linear or branched alkyl group having from 8 to 20 carbon atoms or a linear or branched alkenyl group having from 8 to 20 carbon atoms, more preferably a linear or branched alkyl group having from 9 to 15 carbon atoms or a linear or branched alkenyl group having from 9 to 15 carbon atoms, even more preferably a linear or branched alkyl group having from 9 to 15 carbon atoms, particularly preferably a linear or branched alkyl group having from 10 to 14 carbon atoms, and most preferably a linear or branched alkyl group having 12 carbon atoms.

[0046] In the above formula (I), the organic group represented by R' is not particularly limited, but is preferably a linear or branched alkyl group having from 1 to 6 carbon atoms, a linear or branched alkenyl group having from 2 to 6 carbon atoms, a cyclic alkyl group having from 3 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or a hydroxyalkyl group having from 1 to 6 carbon atoms.

[0047] Specific examples of the linear or branched alkyl group having from 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a tert-pentyl group, a neopentyl group, a 1,2-dimethylpropyl group, an n-hexyl group, an isohexyl group, a 1,3-dimethylbutyl group, a 1-isopropylpropyl group, and a 1,2-dimethylbutyl group.

[0048] Specific examples of the linear or branched alkenyl group having from 2 to 6 carbon atoms include a vinyl group, an allyl group, a 1-propenyl group, an isopropenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-pentenyl group, a 2-pentenyl group, a 3-pentenyl group, a 1-hexenyl group, a 2-hexenyl group, and a 3-hexenyl group.

[0049] Specific examples of the cyclic alkyl group having 3 to 20 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

[0050] Specific examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a naphthyl group, a biphenyl group, a fluorenyl group, an anthryl group, and a pyrenyl group.

[0051] An aralkyl group refers to an alkyl group in which one hydrogen atom on the alkyl group is substituted with an aryl group, and specific examples of aralkyl groups having 7 to 20 carbon atoms include a benzyl group (phenylmethyl group) and a phenethyl group (phenylethyl group).

[0052] A hydroxyalkyl group having 1 to 6 carbon atoms refers to an alkyl group having 1 to 6 carbon atoms in which at least one hydrogen atom is substituted with a hydroxy group, and specific examples thereof include a carbinol group (-CHOH) and a methylcarbinol group (hydroxyethyl group: -CHCHOH).

[0053] Among these, R' is preferably a linear or branched alkyl group having 1 to 6 carbon atoms, a benzyl group, or a phenethyl group, and more preferably a linear or branched alkyl group having 1 to 6 carbon atoms or a benzyl group.

[0054] In the above formula (I), n represents the number of R bonded to the nitrogen atom. n is preferably an integer of 1 or more and 3 or less, more preferably 1 or 2, and particularly preferably 1.

[0055] Other preferred forms of the quaternary nitrogen-containing onium cation include the following forms:

[0056] Another preferred embodiment of the quaternary nitrogen-containing onium cation has a heterocycle containing a nitrogen atom, and has at least one of a linear or branched alkyl group having 7 or more carbon atoms and a linear or branched alkenyl group having 7 or more carbon atoms on the heterocycle.

[0057] Examples of quaternary nitrogen-containing onium cations containing such a ring (heterocyclic) structure include imidazolinium ions, pyrrolidinium ions, and piperidinium ions.

[0058] Among these, the quaternary nitrogen-containing onium cation containing a ring (heterocyclic) structure is preferably an imidazolinium ion, and in this case, the quaternary imidazolinium cation is preferably represented by the following formula (II):

[0059] [ka]

[0060] In the above formula (II), R" is a linear or branched alkyl group having 7 or more carbon atoms, or a linear or branched alkenyl group having 7 or more carbon atoms. In the above formula (II), examples of the alkyl group and alkenyl group represented by R" include the same alkyl groups and alkenyl groups as those described for R in the above formula (I). Furthermore, preferred embodiments are also the same as those described above, and it is particularly preferred that R" is a linear or branched alkyl group having 8 to 20 carbon atoms, or a linear or branched alkenyl group having 8 to 20 carbon atoms.

[0061] The anion (counter anion) constituting the quaternary nitrogen-containing onium salt compound is not particularly limited as long as it can form a salt with the quaternary nitrogen-containing onium cation. Examples of such anion include fluoride ion (F - ), chloride ions (Cl - ), bromide ion (Br - ) and iodide ion (I - ) and other halide ions; hydrogen sulfate ion (HSO4 - ); sulfite ion (HSO3 - ); Alkyl sulfate ion ((Alkyl)SO4 -Alkyl is an alkyl group having 1 to 8 carbon atoms (e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, preferably ethyl); sulfate ion (SO 2- ); Nitrate ion (NO3 - ); dihydrogen phosphate ion (H2PO4 - ), hydrogen phosphate ion (HPO4 2- ), phosphate ions (PO4 3- ); perchlorate ion (ClO4 - ); hydroxide ion (OH - carboxylic acid anions such as citrate ion, acetate ion, malate ion, fumarate ion, lactate ion, glutarate ion, and maleate ion. Of these, the anion (counter anion) is preferably a halide ion, alkyl sulfate ion, or nitrate ion, more preferably a halide ion or alkyl sulfate ion, and more preferably a chloride ion or ethyl sulfate ion (C2H5SO4 - ) is more preferred, and chloride ion is particularly preferred.

[0062] The quaternary nitrogen-containing onium salt compound according to the present invention preferably contains a quaternary nitrogen-containing onium cation represented by the above formula (I) or formula (II), and more preferably contains a quaternary ammonium cation represented by the above formula (I).

[0063] Furthermore, the quaternary ammonium salt compound containing a quaternary ammonium cation is preferably a compound represented by the following formula (a):

[0064] [ka]

[0065] In the above formula (a), R 11 is a linear or branched alkyl group having 9 to 15 carbon atoms, and R 12 , R 13 and R 14are each independently a linear or branched alkyl group having from 1 to 6 carbon atoms or a benzyl group; X is an anion.

[0066] In the above formula (a), specific examples of the linear or branched alkyl group having 9 to 15 carbon atoms include the same as the specific examples of the linear or branched alkyl group having 9 to 15 carbon atoms given for R in the above formula (I). Specific examples of the linear or branched alkyl group having 1 to 6 carbon atoms include the same as the specific examples given for R' in the above formula (I). Furthermore, X can be a group represented by the formula: N + R 11 R 12 R 13 R 14 Specific examples thereof include those listed above.

[0067] Among them, R 11 is a linear or branched alkyl group having 10 to 14 carbon atoms, and R 12 , R 13 and R 14 are each independently a linear or branched alkyl group having 1 to 3 carbon atoms or a benzyl group, and X is preferably a halide ion or an alkyl sulfate ion. 11 is a linear or branched alkyl group having 10 to 14 carbon atoms, and R 12 , R 13 and R 14 are each independently a linear or branched alkyl group having 1 to 3 carbon atoms or a benzyl group, and X is a chloride ion or an ethyl sulfate ion. 12 , R 13 and R 14It is particularly preferred that one of the groups R is a benzyl group. When the quaternary ammonium salt compound contains a benzyl group, it is easy to form a hydrophilic film (water molecule film) on the surface of the polished object, abrasive grain residue, organic residue, etc., due to π-π interaction, so that the residue can be removed efficiently. Furthermore, R 11 is a linear alkyl group having 10 to 14 carbon atoms, and R 12 is a benzyl group, and R 13 and R 14 are each independently a linear alkyl group having 1 to 3 carbon atoms, and X is particularly preferably a chloride ion.

[0068] The molecular weight of the quaternary nitrogen-containing onium salt compound is not particularly limited, but is preferably less than 1,000, more preferably 800 or less, even more preferably 600 or less, and particularly preferably 400 or less. On the other hand, the lower limit of the molecular weight is not particularly limited, but is preferably 150 or more, more preferably 200 or more, and particularly preferably 300 or more. For example, the molecular weight of the quaternary nitrogen-containing onium salt compound is preferably 150 or more and less than 1,000, more preferably 200 or more and 800 or less, even more preferably 200 or more and 600 or less, and particularly preferably 300 or more and 400 or less.

[0069] The molecular weight of a quaternary nitrogen-containing onium salt compound (low molecular weight compound) can be measured by a known method such as gas chromatography-mass spectrometry (GC-MS). Alternatively, the molecular weight can be determined by identifying the structure of the compound using a method such as NMR and then performing calculations based on the structure.

[0070] The quaternary nitrogen-containing onium salt compound that can be used as component (A) may be synthesized or commercially available, such as Catiogen (registered trademark) BC-50, Catiogen (registered trademark) ES-L, and Catiogen (registered trademark) TMS (all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), NissanCation (registered trademark) 2-OLR, and NissanCation (registered trademark) AR-4 (all manufactured by NOF Corporation).

[0071] The quaternary nitrogen-containing onium salt compounds as component (A) can be used either individually or in combination of two or more.

[0072] The content of component (A) in the surface treatment composition is appropriately set depending on the type of component (A) used and the desired effect. The content of component (A) is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and even more preferably more than 0.005% by mass (relative to the total mass of the surface treatment composition, taken as 100% by mass). The upper limit of the content of component (A) in the surface treatment composition is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, even more preferably 0.1% by mass or less, and particularly preferably less than 0.1% by mass (relative to the total mass of the surface treatment composition, taken as 100% by mass). By setting the upper limit at this level, component (A) is prevented from forming micelles and becoming a residue, thereby enabling efficient removal of the residue.

[0073] In one embodiment of the present invention, the content of component (A) is 0.001% by mass or more and 0.5% by mass or less (relative to the surface treatment composition), with the total mass of the surface treatment composition being 100% by mass. In one embodiment of the present invention, the content of component (A) is 0.005% by mass or more and 0.3% by mass or less (relative to the surface treatment composition), with the total mass of the surface treatment composition being 100% by mass. In one embodiment of the present invention, the content of component (A) is more than 0.005% by mass or less and 0.1% by mass or less (relative to the surface treatment composition), with the total mass of the surface treatment composition being 100% by mass. In one embodiment of the present invention, the content of component (A) is more than 0.005% by mass or less and 0.1% by mass, with the total mass of the surface treatment composition being 100% by mass. Note that when the surface treatment composition contains two or more types of component (A), the content of component (A) refers to the total amount of these.

[0074] <(B) component> The surface treatment composition according to the present invention contains a nonionic polymer as component (B). The term "nonionic polymer" used herein refers to a polymer that does not contain anionic groups such as carboxylic acid groups, sulfonic acid groups, or phosphate groups, or cationic groups such as amino groups or quaternary ammonium groups within the molecule.

[0075] When the surface treatment composition contains an anionic polymer instead of component (B), the component (A) and the anionic polymer aggregate, making it difficult to prepare a uniform surface treatment composition. Furthermore, when the surface treatment composition contains a cationic polymer such as polyethyleneimine instead of component (B), the cationic polymer repels the positive charge of component (A) on the surface of the polished object, preventing simultaneous adsorption of component (A) to the surface of the polished object. Therefore, the effect of improving the wettability of the polished surface of the polished object is insufficient, and a water molecule film cannot be efficiently formed on the surface, making it prone to the adhesion of organic residues.

[0076] In contrast to these polymers, nonionic polymers can promote the removal of residues on the surface of the polished object by improving the wettability of the surface of the polished object, without interfering with the control of the zeta potential (positive charging) of the polished object, abrasive residues, organic residues, etc. by the above-mentioned component (A).

[0077] The nonionic polymer may be a polymer having the same (homopolymer) or different (copolymer) repeating units, and may typically be a compound having a weight-average molecular weight (Mw) of 1,000 or more. When the nonionic polymer is a copolymer, the copolymer may be in the form of a block copolymer, random copolymer, graft copolymer, or alternating copolymer.

[0078] Examples of nonionic water-soluble polymers include polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, poly(N-vinylacetamide), polyamines, polyvinyl ethers (such as polyvinyl methyl ether, polyvinyl ethyl ether, and polyvinyl isobutyl ether), water-soluble polysaccharides such as polyglycerin, polyethylene glycol, polypropylene glycol, and hydroxyethyl cellulose, alginic acid polyhydric alcohol esters, water-soluble urea resins, dextrin derivatives, and casein. In addition to those having such main chain structures, graft copolymers having a nonionic polymer structure in the side chain can also be suitably used. Furthermore, copolymers such as ethylene-vinyl alcohol copolymer and butenediol-vinyl alcohol copolymer can also be used.

[0079] Among these, preferred nonionic water-soluble polymers are polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, poly(N-vinylacetamide), polyethylene glycol, hydroxyethyl cellulose, and butenediol-vinyl alcohol copolymer. Therefore, the nonionic polymer (B) preferably contains at least one selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, poly(N-vinylacetamide), polyethylene glycol, hydroxyethyl cellulose, and butenediol-vinyl alcohol copolymer. Furthermore, more preferred nonionic polymers are polyvinyl alcohol and polyvinylpyrrolidone. Furthermore, polyvinyl alcohol is particularly preferred from the viewpoints of its ability to retain water molecules through hydrogen bonds and its high effectiveness in reducing the etching rate for polished objects containing polycrystalline silicon.

[0080] The lower limit of the weight-average molecular weight (Mw) of the nonionic polymer is preferably 1,000 or more, more preferably 3,000 or more, even more preferably more than 5,000, and particularly preferably 10,000 or more. The upper limit of the weight-average molecular weight (Mw) of the nonionic polymer is preferably 1,000,000 or less, more preferably 100,000 or less, even more preferably 50,000 or less, and particularly preferably 30,000 or less. For example, the weight average molecular weight (Mw) of the nonionic polymer is preferably 1,000 or more and 1,000,000 or less, more preferably 3,000 or more and 100,000 or less, even more preferably more than 5,000 and 100,000 or less, even more preferably more than 5,000 and 50,000 or less, particularly preferably more than 5,000 and 30,000 or less, and most preferably 10,000 or more and 30,000 or less.

[0081] The weight average molecular weight (Mw) of the nonionic polymer can be measured as a polyethylene glycol equivalent value using gel permeation chromatography (GPC), and details of the measurement method will be described in the Examples below.

[0082] The nonionic polymer that can be used as component (B) may be synthetically produced or commercially available, such as JMR (registered trademark)-10HH and JMR (registered trademark)-3HH (both from Nippon Vinyl Acetate & Poval Co., Ltd.), Pitzcol (registered trademark) K30A and K30L (both from Daiichi Kogyo Seiyaku Co., Ltd.), and CMC Daicel (registered trademark) 1150 and 1170 (both from Daicel Miraize Co., Ltd.).

[0083] The nonionic polymer as component (B) can be used either alone or in combination of two or more.

[0084] The content of component (B) in the surface treatment composition is appropriately determined depending on the type of component (B) used and the desired effect. The content of component (B) is preferably 0.00001% by mass or more, more preferably more than 0.0001% by mass, and even more preferably 0.01% by mass or more (relative to the total mass of the surface treatment composition, taken as 100% by mass). The upper limit of the content of component (B) in the surface treatment composition is preferably 2% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less (relative to the total mass of the surface treatment composition, taken as 100% by mass). In one embodiment of the present invention, the content of component (B) is 0.00001% by mass or more and 2% by mass or less (relative to the total mass of the surface treatment composition, taken as 100% by mass). In one embodiment of the present invention, the content of component (B) is more than 0.0001% by mass and 1.5% by mass or less (relative to the total mass of the surface treatment composition, taken as 100% by mass). In one embodiment of the present invention, the content of component (B) is 0.01% by mass or more and 1.0% by mass or less (relative to the surface treatment composition), with the total mass of the surface treatment composition being 100% by mass. When the surface treatment composition contains two or more types of component (B), the content of component (B) refers to the total amount of these.

[0085] Alternatively or additionally, the mixing ratio of component (A) to component (B) in the surface treatment composition is appropriately set depending on the type of component (A) and component (B) used and the desired effect. The mixing ratio of component (A) to component (B) (component (A) / component (B) content ratio) (mass ratio) is preferably 0.01 or more, more preferably 0.03 or more, and even more preferably more than 0.05. The mixing ratio of component (A) to component (B) (component (A) / component (B) content ratio) (mass ratio) is preferably 200 or less, more preferably 10 or less, even more preferably less than 1.0, and particularly preferably less than 0.50. In one embodiment of the present invention, the mixing ratio of component (A) to component (B) (component (A) / component (B) content ratio) (mass ratio) is 0.01 or more and 200 or less. In one embodiment of the present invention, the mixing ratio of the component (A) to the component (B) (component (A) / component (B) content ratio) (mass ratio) is 0.03 or more and 10 or less. In one embodiment of the present invention, the mixing ratio of the component (A) to the component (B) (component (A) / component (B) content ratio) (mass ratio) is more than 0.05 and less than 1.0. In one embodiment of the present invention, the mixing ratio of the component (A) to the component (B) (component (A) / component (B) content ratio) (mass ratio) is more than 0.05 and less than 0.50.

[0086] <(C) component> The surface treatment composition according to the present invention contains, in addition to the above-mentioned components (A) and (B), a component (C). Component (C) is a compound represented by the formula: A-COO - NH4 + In this specification, the term "buffer" refers to a substance that imparts a buffering effect to the surface treatment composition (solution) in order to maintain a constant pH.

[0087] Component (C) is a compound represented by the formula: A-COO - NH4 + Although component (C) may contain components other than the buffer represented by the formula: A-COO (for example, known buffers), from the viewpoint of further improving the effects of the present invention, component (C) is preferably a buffer represented by the formula: A-COO - NH4 +(Component (C) is composed of a buffer represented by the above formula: A-COO - NH4 + The presence of component (C) makes it possible to efficiently remove residues remaining on the surface of a polished object. It also makes it possible to keep the etching rate for a polished object containing polycrystalline silicon low. That is, in a preferred embodiment of the present invention, component (C) is a buffer represented by the above formula: A-COO - NH4 + (Component (C) is composed of a buffer represented by the above formula: A-COO - NH4 + (It is a buffer agent indicated by

[0088] The above formula: A-COO - NH4 + In the formula (I), A is an alkyl group having 1 to 10 carbon atoms or a phenyl group. Here, examples of the alkyl group include the same alkyl groups as those given as specific examples for R' in the above formula (I). Of these, from the viewpoint of further improving the effects of the present invention, A is preferably a linear or branched alkyl group having 1 to 8 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, further preferably a methyl group (ammonium acetate) or an ethyl group (ammonium propionate), and particularly preferably a methyl group (ammonium acetate). That is, in a preferred embodiment of the present invention, the buffer is a group represented by the above formula: A-COO, in which A is a linear or branched alkyl group having 1 to 8 carbon atoms. - NH4 + In a more preferred embodiment of the present invention, the buffering agent is represented by the above formula: A-COO, where A is a linear or branched alkyl group having from 1 to 3 carbon atoms. - NH4 + In a further preferred embodiment of the invention, the buffering agent has the above formula: A-COO where R is a methyl or ethyl group. - NH4 + (wherein the buffer is ammonium acetate or ammonium propionate). In a particularly preferred form of the invention, the buffer is ammonium acetate.

[0089] The content of component (C) in the surface treatment composition is appropriately determined depending on the type of component (C) used and the desired effect. The content of component (C) is preferably 0.05% by mass or more, more preferably more than 0.1% by mass, and even more preferably 0.2% by mass or more (relative to the total mass of the surface treatment composition, taken as 100% by mass). The upper limit of the content of component (C) in the surface treatment composition is preferably 2% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less (relative to the total mass of the surface treatment composition, taken as 100% by mass). In one embodiment of the present invention, the content of component (C) is 0.05% by mass or more and 2% by mass or less (relative to the total mass of the surface treatment composition, taken as 100% by mass). In one embodiment of the present invention, the content of component (C) is more than 0.1% by mass and 1.5% by mass or less (relative to the total mass of the surface treatment composition, taken as 100% by mass). In one embodiment of the present invention, the content of component (C) is 0.2% by mass or more and 1.0% by mass or less (relative to the surface treatment composition), with the total mass of the surface treatment composition being 100% by mass. When the surface treatment composition contains two or more types of component (C), the content of component (C) refers to the total amount of these.

[0090] Instead of or in addition to the above, the mixing ratio of component (A) and component (C) in the surface treatment composition is appropriately set according to the types of component (A) and component (C) used and the desired effects. The mixing ratio of component (A) to component (C) ((A) component / (C) component content ratio) (mass ratio) is preferably 0.01 or more, more preferably 0.02 or more, and even more preferably more than 0.03. The mixing ratio of component (A) to component (C) ((A) component / (C) component content ratio) (mass ratio) is preferably 1.0 or less, more preferably 0.5 or less, even more preferably less than 0.5, and particularly preferably less than 0.1. In one embodiment of the present invention, the mixing ratio of component (A) to component (C) ((A) component / (C) component content ratio) (mass ratio) is 0.01 or more and 1.0 or less. In one embodiment of the present invention, the mixing ratio of component (A) to component (C) ((A) component / (C) component content ratio) (mass ratio) is 0.02 or more and 0.5 or less. In one embodiment of the present invention, the mixing ratio of component (A) to component (C) ((A) component / (C) component content ratio) (mass ratio) is more than 0.03 and less than 0.5. In one embodiment of the present invention, the mixing ratio of component (A) to component (C) ((A) component / (C) component content ratio) (mass ratio) is more than 0.03 and less than 0.1.

[0091] <pH adjuster ((D) component)> The surface treatment composition according to the present invention essentially contains the above components (A) to (C), but in addition to these, it is preferably further contains a pH adjuster. That is, in a preferred form of the present invention, the surface treatment composition further contains component (D): (D) component: pH adjuster.

[0092] The pH adjuster is not particularly limited, and can be a known pH adjuster used in the field of surface treatment compositions, and can be a known acid, base, or their salts. Examples of pH adjusters include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, eicosapentaenoic acid, lactic acid, malic acid, citric acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, cinnamic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, aconitic acid, amino acids, Examples of suitable pH adjusters include organic acids such as carboxylic acids (e.g., anthranilic acid), sulfonic acids, and organic phosphonic acids; inorganic acids (e.g., nitric acid, carbonic acid, hydrochloric acid, phosphoric acid, hypophosphorous acid, phosphorous acid, phosphonic acid, boric acid, hydrofluoric acid, orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, metaphosphoric acid, and hexametaphosphoric acid); alkali metal hydroxides (e.g., potassium hydroxide (KOH) and sodium hydroxide (NaOH)); alkali metal carbonates (e.g., potassium carbonate (KCO) and sodium carbonate (NaCO)); hydroxides of Group 2 elements; ammonia (ammonium hydroxide); and organic bases (e.g., quaternary ammonium hydroxide compounds). The pH adjuster may be a synthetic product or a commercially available product. These pH adjusters may be used alone or in combination. Among these, potassium hydroxide, sodium hydroxide, sodium carbonate, and ammonia are preferred, with potassium hydroxide, sodium hydroxide, and ammonia being particularly preferred. That is, in a preferred embodiment of the present invention, the pH adjuster is at least one selected from the group consisting of potassium hydroxide, sodium hydroxide, sodium carbonate, and ammonia. In a more preferred embodiment of the present invention, the pH adjuster is at least one selected from the group consisting of potassium hydroxide, sodium hydroxide, and ammonia. In a particularly preferred embodiment of the present invention, the pH adjuster is ammonia.

[0093] The content of the pH adjuster in the surface treatment composition may be appropriately selected so that the surface treatment composition has the desired pH value, which will be described in detail below.

[0094] <pH of surface treatment composition> The pH of the surface treatment composition according to the present invention is greater than 7.0. If the pH of the surface treatment composition is 7.0 or less, residue remaining on the surface of the polished object cannot be sufficiently removed. From the viewpoint of further improving the effects of the present invention, the pH of the surface treatment composition is preferably 7.5 or greater, more preferably greater than 7.5, and particularly preferably greater than 8.5. The pH of the surface treatment composition is preferably less than 11.0, more preferably less than 10.5, and particularly preferably less than 10.0. That is, in one embodiment of the present invention, the pH of the surface treatment composition is 7.5 or greater and less than 11.0. In one embodiment of the present invention, the pH of the surface treatment composition is greater than 7.5 and less than 10.5. In one embodiment of the present invention, the pH of the surface treatment composition is greater than 8.5 and less than 10.0. The pH of the surface treatment composition is measured by the method described in the examples.

[0095] <Solvent> The surface treatment composition according to the present invention preferably contains a solvent. The solvent has the function of dispersing or dissolving each component. The solvent preferably contains water, and more preferably consists of water alone. Alternatively, the solvent may be a mixed solvent of water and an organic solvent to disperse or dissolve each component. In this case, examples of the organic solvent used include water-miscible organic solvents such as acetone, acetonitrile, ethanol, methanol, isopropanol, glycerin, ethylene glycol, propylene glycol, and triethanolamine. Alternatively, these organic solvents may be used without mixing with water, and the components may be dispersed or dissolved therein, followed by mixing with water. These organic solvents may be used alone or in combination of two or more.

[0096] The water preferably contains as little residue as possible to prevent contamination of the polished object or inhibition of the action of other components. For example, water with a total transition metal ion content of 100 ppb or less is preferred. The purity of the water can be increased by, for example, removing residual ions using an ion exchange resin, removing foreign matter using a filter, or by distillation. Specifically, it is preferred to use, for example, deionized water (ion-exchanged water), pure water, ultrapure water, distilled water, etc.

[0097] <Surfactant> The surface treatment composition according to the present invention may further contain a surfactant. The type of surfactant is not particularly limited, and may be any of nonionic, anionic, cationic, and amphoteric surfactants.

[0098] Examples of nonionic surfactants include compounds other than the above-mentioned component (B), such as alkyl ether surfactants (e.g., polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, etc.); alkyl phenyl ether surfactants (e.g., polyoxyethylene octylphenyl ether, etc.); alkyl ester surfactants (e.g., polyoxyethylene laurate, etc.); alkyl amine surfactants (e.g., polyoxyethylene lauryl amino ether, etc.); alkyl amide surfactants (e.g., polyoxyethylene lauric acid amide, etc.); polypropylene glycol ether surfactants (e.g., polyoxyethylene polyoxypropylene ether, etc.); alkanolamide surfactants (e.g., oleic acid diethanolamide, etc.); and allyl phenyl ether surfactants (e.g., polyoxyalkylene allyl phenyl ether, etc.). Other examples of nonionic surfactants that can be used include propylene glycol, diethylene glycol, monoethanolamine, alcohol ethoxylates, alkylphenol ethoxylates, tertiary acetylene glycols, and alkanolamides. Since the above-mentioned component (B) can function as a nonionic surfactant, the addition of a separate nonionic surfactant is not necessary.

[0099] Examples of anionic surfactants include carboxylic acid types such as sodium myristate, sodium palmitate, sodium stearate, sodium laurate, and potassium laurate; sulfate ester types such as sodium octyl sulfate; phosphate ester types such as lauryl phosphate and sodium lauryl phosphate; and sulfonic acid types such as sodium dioctyl sulfosuccinate and sodium dodecylbenzenesulfonate.

[0100] Examples of cationic surfactants include compounds other than the above-mentioned component (A), such as amines such as laurylamine hydrochloride. Note that, since the above-mentioned component (A) can function as a cationic surfactant, it is not necessary to add a separate cationic surfactant.

[0101] Examples of amphoteric surfactants include lecithin, alkylamine oxide, alkylbetaines such as N-alkyl-N,N-dimethylammonium betaine, and sulfobetaines.

[0102] The surfactants may be used singly or in combination of two or more. In addition, the surfactants may be commercially available products or synthetic products.

[0103] When the surface treatment composition contains a surfactant, the lower limit of the surfactant content is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on 100% by mass of the total mass of the surface treatment composition. The upper limit of the surfactant content in the surface treatment composition is preferably 5% by mass or less, more preferably 1% by mass or less, based on 100% by mass of the total mass of the surface treatment composition. When the surface treatment composition contains two or more surfactants, the surfactant content refers to the total amount of these surfactants.

[0104] <Chelating agent> The surface treatment composition according to the present invention may further contain a chelating agent. Examples of the chelating agent include aminocarboxylic acid chelating agents and organic phosphonic acid chelating agents. Examples of the aminocarboxylic acid chelating agent include ethylenediaminetetraacetic acid, sodium ethylenediaminetetraacetate, nitrilotriacetic acid, sodium nitrilotriacetate, ammonium nitrilotriacetate, hydroxyethylethylenediaminetriacetic acid, sodium hydroxyethylethylenediaminetriacetate, diethylenetriaminepentaacetic acid, sodium diethylenetriaminepentaacetate, triethylenetetraminehexaacetic acid, and sodium triethylenetetraminehexaacetate. Examples of organic phosphonic acid chelating agents include 2-aminoethylphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, aminotri(methylenephosphonic acid), ethylenediaminetetrakis(methylenephosphonic acid) (EDTPO), diethylenetriaminepenta(methylenephosphonic acid), ethane-1,1-diphosphonic acid, ethane-1,1,2-triphosphonic acid, ethane-1-hydroxy-1,1-diphosphonic acid, ethane-1-hydroxy-1,1,2-triphosphonic acid, ethane-1,2-dicarboxy-1,2-diphosphonic acid, methanehydroxyphosphonic acid, 2-phosphonobutane-1,2-dicarboxylic acid, 1-phosphonobutane-2,3,4-tricarboxylic acid, and α-methylphosphonosuccinic acid. Of these, organic phosphonic acid chelating agents are more preferred. Among these, ethylenediaminetetrakis(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), and diethylenetriaminepentaacetic acid are preferred. Particularly preferred chelating agents include ethylenediaminetetrakis(methylenephosphonic acid) and diethylenetriaminepenta(methylenephosphonic acid).

[0105] The chelating agent may be used singly or in combination of two or more kinds. In addition, the chelating agent may be a commercially available product or a synthetic product.

[0106] When the surface treatment composition contains a chelating agent, the lower limit of the content of the chelating agent is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, and even more preferably 0.002% by mass or more, based on the total mass of the surface treatment composition being 100% by mass. The upper limit of the content of the chelating agent is preferably 1% by mass or less, more preferably 0.5% by mass or less, even more preferably 0.3% by mass or less, and particularly preferably 0.15% by mass or less. Note that when the surface treatment composition contains two or more chelating agents, the content of the chelating agents refers to the total amount of these.

[0107] <Other additives> The surface treatment composition according to one embodiment of the present invention may contain other additives in any proportion as needed, as long as the effects of the present invention are not impaired. However, components other than the essential components of the surface treatment composition according to one embodiment of the present invention may cause foreign matter (residue), so it is desirable to add as few additives as possible. Therefore, it is preferable to add as few other additives as possible. Examples of other additives include antifungal agents (preservatives), dissolved gases, reducing agents, oxidizing agents, etc. The surface treatment composition according to the present invention contains a nonionic polymer and is alkaline. Therefore, among these, the surface treatment composition according to the present invention preferably contains an antifungal agent (preservative). When the surface treatment composition according to the present invention contains an antifungal agent (preservative), the antifungal agent (preservative) that can be used is not particularly limited and can be appropriately selected depending on the type of nonionic polymer (component (B)). Specific examples include isothiazolin-based preservatives such as 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, and 1,2-benzisothiazol-3(2H)-one (BIT), as well as phenoxyethanol.

[0108] Alternatively, the antifungal agent (antiseptic) may be a compound represented by the following Chemical Formula 1:

[0109] [ka]

[0110] In the above chemical formula 1, R 1 ~R 5 are each independently a hydrogen atom or a substituent composed of at least two atoms selected from the group consisting of carbon atoms, hydrogen atoms, and oxygen atoms.

[0111] Examples of the substituent composed of at least two types of atoms selected from the group consisting of carbon atoms, hydrogen atoms, and oxygen atoms include, for example, a hydroxy group, a carboxy group, an alkyl group having from 1 to 20 carbon atoms, a hydroxyalkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, a hydroxyalkoxy group having from 1 to 20 carbon atoms, an alkoxycarbonyl group having from 2 to 21 carbon atoms, an aryl group having from 6 to 30 carbon atoms, an aralkyl group (arylalkyl group) having from 7 to 31 carbon atoms, an aryloxy group having from 6 to 30 carbon atoms, an aryloxycarbonyl group having from 6 to 30 carbon atoms, an aralkyloxycarbonyl group having from 8 to 32 carbon atoms, an acyl group having from 2 to 20 carbon atoms, and an acyloxy group having from 2 to 20 carbon atoms.

[0112] More specifically, examples of alkyl groups having 1 to 20 carbon atoms include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl groups; branched alkyl groups such as isopropyl, isobutyl, s-butyl, t-butyl, t-amyl, neopentyl, 3-methylpentyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-methyl-1-propylbutyl, 1,1-dipropylbutyl, 1,1-dimethyl-2-methylpropyl, and 1-methyl-1-isopropyl-2-methylpropyl groups; and cyclic alkyl groups such as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and norbornenyl groups.

[0113] Examples of hydroxyalkyl groups having 1 to 20 carbon atoms include a hydroxymethyl group, a 2-hydroxyethyl group, a 2-hydroxy-n-propyl group, a 3-hydroxy-n-propyl group, a 2-hydroxy-n-butyl group, a 3-hydroxy-n-butyl group, a 4-hydroxy-n-butyl group, a 2-hydroxy-n-pentyl group, a 3-hydroxy-n-pentyl group, a 4-hydroxy-n-pentyl group, a 5-hydroxy-n-pentyl group, a 2-hydroxy-n-hexyl group, a 3-hydroxy-n-hexyl group, a 4-hydroxy-n-hexyl group, a 5-hydroxy-n-hexyl group, and a 6-hydroxy-n-hexyl group.

[0114] Examples of the alkoxy group having from 1 to 20 carbon atoms include linear alkoxy groups such as a methoxy group, an ethoxy group, an n-propyloxy group, an n-butyloxy group, an n-pentyloxy group, an n-hexyloxy group, an n-heptyloxy group, an n-octyloxy group, an n-nonyloxy group, and an n-decyloxy group; an isopropyloxy group, an isobutyloxy group, an s-butyloxy group, a t-butyloxy group, a t-amyloxy group, a neopentyloxy group, a 3-methylpentyloxy group, and a 1,1-diethyloxy group. branched alkoxy groups such as a 1,1-dimethylbutyloxy group, a 1-methyl-1-propylbutyloxy group, a 1,1-dipropylbutyloxy group, a 1,1-dimethyl-2-methylpropyloxy group, and a 1-methyl-1-isopropyl-2-methylpropyloxy group; and cyclic alkoxy groups such as a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, a cycloheptyloxy group, a cyclooctyloxy group, and a norbornenyloxy group.

[0115] Examples of hydroxyalkoxy groups having from 1 to 20 carbon atoms include a hydroxymethoxy group, a 2-hydroxyethoxy group, a 2-hydroxy-n-propyloxy group, a 3-hydroxy-n-propyloxy group, a 2-hydroxy-n-butyloxy group, a 3-hydroxy-n-butyloxy group, a 4-hydroxy-n-butyloxy group, a 2-hydroxy-n-pentyloxy group, a 3-hydroxy-n-pentyloxy group, a 4-hydroxy-n-pentyloxy group, a 5-hydroxy-n-pentyloxy group, a 2-hydroxy-n-hexyloxy group, a 3-hydroxy-n-hexyloxy group, a 4-hydroxy-n-hexyloxy group, a 5-hydroxy-n-hexyloxy group, and a 6-hydroxy-n-hexyloxy group.

[0116] Examples of alkoxycarbonyl groups having 2 to 21 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, a butoxycarbonyl group, a pentyloxycarbonyl group, a hexyloxycarbonyl group, an octyloxycarbonyl group, and a decyloxycarbonyl group.

[0117] Examples of the aryl group having 6 to 30 carbon atoms include a phenyl group, a naphthyl group, an anthranyl group, and a pyrenyl group.

[0118] Examples of aralkyl groups (arylalkyl groups) having from 7 to 31 carbon atoms include benzyl groups and phenethyl groups (phenylethyl groups), and examples of aryloxy groups having from 6 to 30 carbon atoms include phenyloxy groups (phenoxy groups), naphthyloxy groups, anthranyloxy groups, and pyrenyloxy groups.

[0119] Examples of the aryloxycarbonyl group having from 7 to 31 carbon atoms include a phenyloxycarbonyl group, a naphthyloxycarbonyl group, an anthranyloxycarbonyl group, and a pyrenyloxycarbonyl group.

[0120] Examples of the aralkyloxycarbonyl group having from 8 to 32 carbon atoms include a benzyloxycarbonyl group and a phenethyloxycarbonyl group.

[0121] Examples of the acyl group having 1 to 20 carbon atoms include a methanoyl group (formyl group), an ethanoyl group (acetyl group), a propanoyl group, a butanoyl group, a pentanoyl group, a hexanoyl group, an octanoyl group, a decanoyl group, and a benzoyl group.

[0122] Examples of the acyloxy group having from 1 to 20 carbon atoms include a formyloxy group, an acetyloxy group, a propanoyloxy group, a butanoyloxy group, a pentanoyloxy group, a hexanoyloxy group, an octanoyloxy group, a decanoyloxy group, and a benzoyloxy group.

[0123] Furthermore, the antifungal agent represented by the above chemical formula 1 is preferably at least one selected from the group consisting of compounds represented by the following chemical formulas 1-a to 1-c.

[0124] [ka]

[0125] In the above chemical formula 1, R 1 ~R 3 are each independently a substituent composed of at least two atoms selected from the group consisting of carbon atoms, hydrogen atoms, and oxygen atoms.

[0126] Examples of the substituent composed of at least two types of atoms selected from the group consisting of carbon atoms, hydrogen atoms, and oxygen atoms are the same as those described above, and therefore, description thereof will be omitted here.

[0127] More specific examples of the compound represented by Chemical Formula 1 above include parahydroxybenzoic acid esters such as methyl parahydroxybenzoate, ethyl parahydroxybenzoate, butyl parahydroxybenzoate, and benzyl parahydroxybenzoate; salicylic acid, methyl salicylate, phenol, catechol, resorcinol, hydroquinone, isopropylphenol, cresol, thymol, phenoxyethanol, phenylphenols (2-phenylphenol, 3-phenylphenol, 4-phenylphenol), and 2-phenylethyl alcohol (phenethyl alcohol).

[0128] Among these, from the viewpoint of more effectively achieving the intended effects of the present invention, the compound represented by the above chemical formula 1 is preferably at least one selected from the group consisting of ethyl parahydroxybenzoate, butyl parahydroxybenzoate, and phenylphenol, and more preferably butyl parahydroxybenzoate.

[0129] Alternatively, the antifungal agent (preservative) may be an unsaturated fatty acid. Examples of unsaturated fatty acids include monounsaturated fatty acids such as crotonic acid, myristoleic acid, palmitoleic acid, oleic acid, and ricinoleic acid; diunsaturated fatty acids such as sorbic acid, linoleic acid, and eicosadienoic acid; triunsaturated fatty acids such as linolenic acid, pinolenic acid, and eleostearic acid; tetraunsaturated fatty acids such as stearidonic acid and arachidonic acid; pentaunsaturated fatty acids such as bosseopentaenoic acid and eicosapentaenoic acid; and hexaunsaturated fatty acids such as docosahexaenoic acid and herring acid.

[0130] Among these, sorbic acid is preferred as the unsaturated fatty acid from the viewpoint of more effectively achieving the desired effects of the present invention.

[0131] In addition to the above, 1,2-alkanediols such as 1,2-pentanediol, 1,2-hexanediol, and 1,2-octanediol; alkyl glyceryl ethers such as 2-ethylhexylglyceryl ether (ethylhexylglycerin); capric acid, dehydroacetic acid, and other compounds may also be used as antifungal agents (preservatives).

[0132] The above antifungal agents (antiseptics) may be used alone or in combination of two or more kinds.

[0133] When the surface treatment composition contains an antifungal agent (preservative), the lower limit of the content (concentration) of the antifungal agent (preservative) is not particularly limited, but is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, even more preferably 0.005% by mass or more, and particularly preferably 0.01% by mass or more. The upper limit of the content (concentration) of the antifungal agent (preservative) is not particularly limited, but is preferably 5% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and particularly preferably 0.1% by mass or less. That is, the content (concentration) of the antifungal agent (preservative) in the surface treatment composition is preferably 0.0001% by mass or more and 5% by mass or less, more preferably 0.001% by mass or more and 1% by mass or less, even more preferably 0.005% by mass or more and 0.5% by mass or less, and particularly preferably 0.01% by mass or more and 0.1% by mass or less. Within this range, a sufficient effect of inactivating or destroying microorganisms can be obtained. When the surface treatment composition contains two or more types of antifungal agents (preservatives), the above content refers to the total amount of these.

[0134] In one embodiment of the present invention, the surface treatment composition consists essentially of a quaternary nitrogen-containing onium salt compound (component (A)), a nonionic polymer (component (B)), a buffer (component (C)), a pH adjuster (component (D)), water, and at least one selected from the group consisting of a mildewcide, an organic solvent, a surfactant, and a chelating agent. In one embodiment of the present invention, the surface treatment composition consists essentially of a quaternary nitrogen-containing onium salt compound (component (A)), a nonionic polymer (component (B)), a buffer (component (C)), a pH adjuster (component (D)), water, and at least one selected from the group consisting of a mildewcide and an organic solvent. In one embodiment of the present invention, the surface treatment composition consists essentially of a quaternary nitrogen-containing onium salt compound (component (A)), a nonionic polymer (component (B)), a buffer (component (C)), a pH adjuster (component (D)), and water. In the above embodiment, "the surface treatment composition is substantially composed of X" means that the total content of X exceeds 99% by mass (upper limit: 100% by mass) (relative to the surface treatment composition), with the total mass of the surface treatment composition being 100% by mass. Preferably, the surface treatment composition is composed of X (the total content = 100% by mass). For example, the phrase "the surface treatment composition is substantially composed of a quaternary nitrogen-containing onium salt compound (component (A)), a nonionic polymer (component (B)), a buffer (component (C)), a pH adjuster (component (D)), water, and at least one of an anti-mold agent and an organic solvent" means that the total content of the quaternary nitrogen-containing onium salt compound (component (A)), a nonionic polymer (component (B)), a buffer (component (C)), a pH adjuster (component (D)), water, and at least one of an anti-mold agent and an organic solvent is more than 99% by mass (upper limit: 100% by mass) of the total mass of the surface treatment composition (relative to the surface treatment composition), and it is preferable that the surface treatment composition is composed of a quaternary nitrogen-containing onium salt compound (component (A)), a nonionic polymer (component (B)), a buffer (component (C)), a pH adjuster (component (D)), water, and at least one of an anti-mold agent and an organic solvent (the above total content = 100% by mass).

[0135] To further improve the residue (foreign matter) removal effect, the surface treatment composition of the present invention preferably contains substantially no abrasive grains. Here, "substantially no abrasive grains" refers to a case where the content of abrasive grains relative to the entire surface treatment composition is less than 0.01% by mass. That is, in one embodiment of the present invention, the content of abrasive grains is less than 0.01% by mass (lower limit: 0% by mass) (relative to the surface treatment composition), with the total mass of the surface treatment composition being 100% by mass.

[0136] <Method of manufacturing the surface treatment composition> The method for producing the surface treatment composition of the present invention is not particularly limited, and can be, for example, obtained by stirring and mixing component (A) (a quaternary nitrogen-containing onium salt compound), component (B) (a nonionic polymer), component (C) (a buffering agent), and, if necessary, at least one selected from the group consisting of component (D) (a pH adjuster), a surfactant, a chelating agent, water, an organic solvent, a fungicide (preservative), and other additives. In one embodiment of the present invention, the surface treatment composition of the present invention is produced by stirring and mixing component (A) (a quaternary nitrogen-containing onium salt compound), component (B) (a nonionic polymer), component (C) (a buffering agent), component (D) (a pH adjuster), water, and at least one selected from the group consisting of a fungicide, an organic solvent, a surfactant, and a chelating agent. In one embodiment of the present invention, the surface treatment composition of the present invention is produced by stirring and mixing component (A) (a quaternary nitrogen-containing onium salt compound), component (B) (a nonionic polymer), component (C) (a buffer), component (D) (a pH adjuster), water, and at least one of a mildewcide and an organic solvent. In one embodiment of the present invention, the surface treatment composition of the present invention is produced by stirring and mixing component (A) (a quaternary nitrogen-containing onium salt compound), component (B) (a nonionic polymer), component (C) (a buffer), component (D) (a pH adjuster), and water. The temperature at which the components are mixed is not particularly limited, but is preferably 10°C to 40°C. Heating may be used to increase the dissolution rate. The mixing time is also not particularly limited.

[0137] [Surface treatment method] The surface treatment composition of the present invention can sufficiently remove residues remaining on the surface of a polished object. Furthermore, the etching rate for a polished object containing polycrystalline silicon can be reduced. Therefore, the present invention provides a surface treatment method comprising surface-treating a polished object using the surface treatment composition of the present invention. Here, the polished object may contain at least one selected from the group consisting of silicon nitride, silicon oxide, and polysilicon. That is, the present invention provides a surface treatment method comprising surface-treating a polished object containing at least one selected from the group consisting of silicon nitride, silicon oxide, and polysilicon using the surface treatment composition of the present invention to reduce residues on the surface of the polished object. In this specification, the term "surface treatment method" refers to a method for reducing residues on the surface of a polished object, and is a cleaning method in a broad sense.

[0138] The surface treatment method of the present invention can sufficiently remove residues remaining on the surface of a polished object. That is, the present invention also provides a method for reducing residues on the surface of a polished object, which comprises surface-treating the polished object with the surface treatment composition of the present invention. The present invention also provides a method for reducing residues on the surface of a polished object, which comprises surface-treating the polished object containing at least one selected from the group consisting of silicon nitride, silicon oxide, and polysilicon with the surface treatment composition of the present invention.

[0139] The surface treatment method according to the present invention is carried out by directly contacting the surface treatment composition according to the present invention with the polished object.

[0140] Surface treatment methods mainly include (I) a method using a rinse polishing process and (II) a method using a cleaning process. That is, in one embodiment of the present invention, the surface treatment method is a rinse polishing process or a cleaning process (the surface treatment is performed by a rinse polishing process or a cleaning process). The rinse polishing process and the cleaning process are performed to remove foreign matter (abrasive grain (particle) residues, organic residues such as polymers and pad debris, metal contaminants, etc.) from the surface of the polished object to obtain a clean surface. The above (I) and (II) will be explained below.

[0141] (I) Rinse polishing treatment The surface treatment composition of the present invention is suitable for use in a rinse polishing process. That is, the surface treatment composition of the present invention can be preferably used as a rinse polishing composition. The rinse polishing process is performed on a polishing table (platen) equipped with a polishing pad after a polished object is polished by performing a final polishing (finish polishing) on ​​the object to be polished to obtain a polished object. The rinse polishing process is performed by directly contacting the polished object with the surface treatment composition of the present invention. As a result, the foreign matter on the surface of the polished object to be polished is removed by the frictional force (physical action) of the polishing pad and the chemical action of the surface treatment composition. Among the foreign matter, abrasive grain (particle) residues and organic residues are particularly easily removed by physical action. Therefore, in the rinse polishing process, friction between the polishing pad and the polishing table (platen) can be used to effectively remove abrasive grain (particle) residues and organic residues.

[0142] That is, in this specification, the terms "rinse polishing treatment," "rinse polishing method," and "rinse polishing step" refer to a treatment, a method, and a step, respectively, that use a polishing pad to reduce residues on the surface of an object to be surface-treated.

[0143] Specifically, the rinse polishing treatment can be carried out by placing the polished surface of the object to be polished after the polishing step on the polishing table (platen) of a polishing apparatus, bringing the polishing pad and the polished semiconductor substrate into contact with each other, and supplying a surface treatment composition to the contact area while sliding the polished object to be polished and the polishing pad relative to each other.

[0144] As the polishing device, a general polishing device can be used, which is equipped with a holder for holding the object to be polished, a motor whose rotation speed can be changed, and a polishing platen to which a polishing pad (polishing cloth) can be attached.

[0145] The rinse polishing treatment can be carried out using either a single-side polishing machine or a double-side polishing machine. The polishing machine preferably has a nozzle for discharging the polishing composition as well as a nozzle for discharging the surface treatment composition. The operating conditions of the polishing machine during the rinse polishing treatment are not particularly limited, and can be appropriately set by a person skilled in the art.

[0146] The polishing pad may be made of any material, including ordinary nonwoven fabric, polyurethane, porous fluororesin, etc. The polishing pad is preferably provided with grooves that allow the surface treatment composition to accumulate.

[0147] There are no particular restrictions on the rinse polishing conditions. For example, the rotation speed of the polishing table and the head (carrier) are 10 rpm (0.17 s -1 ) or more 100rpm(1.67s -1 ) or less, and the pressure (polishing pressure) applied to the polished object is preferably 0.5 psi (3.4 kPa) or more and 10 psi (68.9 kPa) or less. The method of supplying the surface treatment composition to the polishing pad is not particularly limited, and for example, a method of continuously supplying it using a pump or the like (flowing it over) is used. There is no limit to the amount of supply, but it is preferable that the surface of the polishing pad is always covered with the surface treatment composition, and it is preferably 10 mL / min or more and 5000 mL / min or less. The rinse polishing time is also not particularly limited, but it is preferably 5 seconds or more and 180 seconds or less.

[0148] After the rinse polishing treatment with the surface treatment composition of the present invention, the polished object to be polished (object to be surface-treated) is preferably pulled up and removed while the surface treatment composition of the present invention is applied thereto.

[0149] (II) Cleaning treatment The surface treatment composition of the present invention may be used in a cleaning treatment. That is, the surface treatment composition of the present invention can be preferably used as a cleaning composition. The cleaning treatment is preferably carried out for the purpose of removing foreign matter from the surface of a polished object (object to be cleaned) after final polishing (finish polishing) of the object to be polished, after the rinse polishing treatment described above, or after another rinse polishing treatment using a rinse polishing composition other than the surface treatment composition of the present invention to obtain a polished object (object to be cleaned). Note that cleaning treatments and the rinse polishing treatment described above are classified according to the location where these treatments are performed. Cleaning treatments are surface treatments performed at a location other than a polishing table (platen), and are preferably surface treatments performed after the polished object to be polished is removed from the polishing table (platen). In cleaning treatments, the surface treatment composition of the present invention can be directly contacted with the polished object to be polished to remove foreign matter from the surface of the object.

[0150] Examples of methods for performing the cleaning treatment include (i) a method in which a cleaning brush is brought into contact with one or both sides of the polished object while holding the polished object, and the surface of the object is scrubbed with the cleaning brush while supplying a surface treatment composition to the contact area, and (ii) a method in which the polished object is immersed in the surface treatment composition and subjected to ultrasonic treatment and agitation (dip method), etc. In such methods, foreign matter on the surface of the polished object is removed by the frictional force of the cleaning brush or the mechanical force generated by the ultrasonic treatment or agitation, and the chemical action of the surface treatment composition.

[0151] In the above method (i), the method of contacting the surface treatment composition with the polished object to be polished is not particularly limited, but examples include a spin method in which the polished object to be polished is rotated at high speed while the surface treatment composition is flowed onto the polished object from a nozzle, and a spray method in which the surface treatment composition is sprayed onto the polished object to be polished and cleaned.

[0152] In terms of more efficient decontamination in a short time, it is preferable to use a spin or spray type cleaning method, and the spin type is more preferable.

[0153] Apparatuses for carrying out such cleaning treatment include batch-type cleaning apparatuses that simultaneously surface-treat multiple polished objects housed in a cassette, and single-wafer cleaning apparatuses that surface-treat a single polished object mounted on a holder, etc. From the viewpoint of shortening cleaning time, the method using a single-wafer cleaning apparatus is preferred.

[0154] Furthermore, examples of devices for performing cleaning include polishing machines equipped with cleaning equipment that scrubs the polished object with a cleaning brush after removing it from the polishing table (platen). By using such a polishing machine, the polished object can be cleaned more efficiently.

[0155] As such a polishing apparatus, a general polishing apparatus having a holder for holding the polished object, a motor with an adjustable rotation speed, a cleaning brush, etc. can be used. As the polishing apparatus, either a single-side polishing apparatus or a double-side polishing apparatus can be used. When a rinse polishing process is performed after the CMP process, it is more efficient and preferable to perform the cleaning process using the same polishing apparatus as used in the rinse polishing process.

[0156] The cleaning brush is not particularly limited, but is preferably a resin brush. The material of the resin brush is not particularly limited, but is preferably PVA (polyvinyl alcohol). The cleaning brush is more preferably a PVA sponge.

[0157] There are no particular restrictions on the cleaning conditions, and they can be set appropriately depending on the type of surface treatment object (polished object) and the type and amount of residue to be removed. For example, the rotation speed of the cleaning brush is 10 rpm (0.17 s -1 ) or more 200rpm(3.33s -1 ) or less, and the rotation speed of the object to be cleaned is 10 rpm (0.17 s -1 ) or more 100rpm(1.67s -1 ) or less. The method for supplying the surface treatment composition to the cleaning brush is not particularly limited, and for example, a method of continuously supplying the composition using a pump or the like (flowing over) is used. There is no limit to the amount of supply, but it is preferable that the cleaning brush and the surface of the object to be cleaned are always covered with the surface treatment composition, and a supply rate of 10 mL / min to 5000 mL / min is preferred. The cleaning time is also not particularly limited, but in the step using the surface treatment composition according to one embodiment of the present invention, it is preferably 5 seconds to 180 seconds. Within such a range, foreign matter can be removed more effectively.

[0158] The temperature of the surface treatment composition during cleaning is not particularly limited, and is usually room temperature, but may be heated to about 40° C. or higher and 70° C. or lower within a range that does not impair performance.

[0159] In the above method (ii), the conditions for the immersion cleaning method are not particularly limited, and known methods can be used.

[0160] Before carrying out the surface treatment by the above method (I) or (II), washing with water may be carried out.

[0161] (Post-cleaning treatment) Furthermore, as a surface treatment method, it is preferable to further wash the polished object after the surface treatment (I) or (II) using the surface treatment composition of the present invention. In this specification, this washing treatment is referred to as a post-cleaning treatment. The post-cleaning treatment is not particularly limited, but examples include a method in which water is simply poured over the object to be surface-treated, or a method in which the object to be surface-treated is simply immersed in water. Similar to the surface treatment by method (II) described above, examples include a method in which the object to be surface-treated is held in a state where a cleaning brush is brought into contact with one or both sides of the object to be surface-treated, and the surface of the object to be surface-treated is scrubbed with the cleaning brush while supplying water or an aqueous solution (e.g., an NH3 aqueous solution) to the contact area, or while supplying water and an aqueous solution (e.g., an NH3 aqueous solution) in any order (water is supplied followed by the aqueous solution, or the aqueous solution is supplied followed by water), or a method in which the object to be surface-treated is immersed in water and subjected to ultrasonic treatment or agitation (dip method). Among these, a preferred method is to hold the object and bring it into contact with one or both sides of the object, and then scrub the surface of the object with the cleaning brush while supplying water or an aqueous solution (e.g., an NH3 aqueous solution) to the contact area, or while supplying water and an aqueous solution (e.g., an NH3 aqueous solution) in any order (water is supplied, followed by the aqueous solution, or NH3 aqueous solution is supplied, followed by water). The apparatus and conditions for the post-cleaning treatment can be found in the description of the surface treatment in (II) above. Here, it is particularly preferred to use deionized water as the water used in the post-cleaning treatment.

[0162] By performing a surface treatment with the surface treatment composition according to one embodiment of the present invention, the residue becomes extremely easy to remove, and therefore, by performing a further cleaning treatment with water after performing a surface treatment with the surface treatment composition according to one embodiment of the present invention, the residue can be removed extremely well.

[0163] [Method of manufacturing semiconductor substrate] The surface treatment method according to the present invention is suitably applied when the polished object is a polished semiconductor substrate. That is, the present invention also provides a method for producing a semiconductor substrate, in which the polished object is a polished semiconductor substrate and the method comprises reducing residues on the surface of the polished semiconductor substrate by the above-described surface treatment method.

[0164] In this case, the polished object to be polished contains at least one of silicon nitride, silicon oxide, and polysilicon. That is, the present invention also provides a method for producing a semiconductor substrate, the method comprising: a polishing step in which the polished object to be polished is a polished semiconductor substrate, the polishing step comprising polishing an unpolished semiconductor substrate containing at least one selected from the group consisting of silicon nitride, silicon oxide, and polysilicon with a polishing composition containing abrasive grains to obtain a polished semiconductor substrate; and a surface treatment step in which residues containing the abrasive grains on the surface of the polished semiconductor substrate are reduced with the surface treatment composition of the present invention.

[0165] Details of the semiconductor substrate to which this manufacturing method is applied are as described above in the description of the polished object to be surface-treated with the surface treatment composition.

[0166] Furthermore, the method for producing a semiconductor substrate is not particularly limited as long as it includes a step of surface treating the surface of a polished semiconductor substrate using the surface treatment composition of the present invention (surface treatment step). Examples of such a production method include a method having a polishing step and a cleaning step to form a polished semiconductor substrate. Another example is a method having a rinse-polishing step between the polishing step and the cleaning step in addition to the polishing step and the cleaning step. Each of these steps will be described below.

[0167] <Polishing process> A polishing step that can be included in the method for manufacturing a semiconductor substrate is a step of polishing a semiconductor substrate to form a polished semiconductor substrate.

[0168] The polishing step is not particularly limited as long as it is a step for polishing a semiconductor substrate, but is preferably a chemical mechanical polishing (CMP) step. The polishing step may be a single step or a multiple step polishing step. Examples of multiple step polishing steps include a step in which a preliminary polishing step (rough polishing step) is followed by a finish polishing step, and a step in which a primary polishing step is followed by one or more secondary polishing steps, followed by a finish polishing step. The surface treatment step using the surface treatment composition according to the present invention is preferably carried out after the finish polishing step.

[0169] As the polishing composition, a known polishing composition can be appropriately used depending on the characteristics of the semiconductor substrate. The polishing composition is not particularly limited, but examples thereof include a polishing composition containing abrasive grains, a water-soluble polymer, a pH adjuster, and a solvent.

[0170] The abrasive grains may be inorganic particles, organic particles, or organic-inorganic composite particles. Specific examples of inorganic particles include particles made of metal oxides such as silica, alumina, ceria, and titania, silicon nitride particles, silicon carbide particles, and boron nitride particles. Specific examples of organic particles include polymethyl methacrylate (PMMA) particles. Furthermore, the abrasive grains used may be commercially available products or synthetic products. Unless otherwise specified, the abrasive grains referred to herein are those that are not surface-modified. The abrasive grains may be used alone or in combination of two or more types. Among these abrasive grains, silica is preferred, and colloidal silica is more preferred.

[0171] The lower limit of the average primary particle size of the abrasive grains is preferably 10 nm or more, more preferably 15 nm or more, even more preferably 20 nm or more, and particularly preferably 30 nm or more. Within this range, a high polishing rate can be maintained, making it suitable for use in rough polishing processes. The upper limit of the average primary particle size of the abrasive grains is preferably 200 nm or less, more preferably 150 nm or less, and even more preferably 100 nm or less. In some embodiments, the average primary particle size may be 75 nm or less, 60 nm or less, or even 50 nm or less. Within this range, the occurrence of defects on the surface of the object to be polished after polishing can be further suppressed. The average primary particle size of the abrasive grains is calculated, for example, based on the specific surface area of ​​the abrasive grains measured by the BET method.

[0172] The lower limit of the average secondary particle diameter of the abrasive grains is preferably 15 nm or more, more preferably 30 nm or more, even more preferably 40 nm or more, even more preferably 50 nm or more, and particularly preferably 60 nm or more. Within this range, a high polishing rate can be maintained. Furthermore, the upper limit of the average secondary particle diameter of the abrasive grains is preferably 300 nm or less, more preferably 200 nm or less, even more preferably 150 nm or less, even more preferably 100 nm or less, and particularly preferably 80 nm or less. Within this range, the occurrence of defects on the surface of the object to be polished after polishing can be further suppressed. The average secondary particle diameter of the abrasive grains can be measured by dynamic light scattering. For example, it can be measured using an "FPAR-1000" model manufactured by Otsuka Electronics Co., Ltd. or an equivalent.

[0173] When the polishing composition is used as a polishing liquid as it is, the content of abrasive grains is preferably 0.1% by mass or more, more preferably 0.4% by mass or more, and even more preferably 1.0% by mass or more, relative to the polishing composition. The polishing rate improves with an increase in the content of abrasive grains. Furthermore, when the polishing composition is used as a polishing liquid as it is, from the viewpoint of preventing scratches, the content of abrasive grains is usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less. Reducing the content of abrasive grains is also preferable from the viewpoint of economy. When two or more types of abrasive grains are used in combination, the above content refers to the total content of the two or more types of abrasive grains.

[0174] Examples of water-soluble polymers include cellulose derivatives, starch derivatives, polymers containing oxyalkylene units, polymers containing nitrogen atoms, and vinyl alcohol-based polymers. Specific examples include hydroxyethyl cellulose, pullulan, random copolymers or block copolymers of ethylene oxide and propylene oxide, polyvinyl alcohol, acetalized polyvinyl alcohol, copolymers of vinyl alcohol and alkylene oxide, polyisoprene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyisoamylene sulfonic acid, polystyrene sulfonate, polyacrylate, polyvinyl acetate, polyethylene glycol, polyvinylimidazole, polyvinylcarbazole, polyvinylpyrrolidone, polyvinylcaprolactam, polyvinylpiperidine, polyacryloylmorpholine, and polyhydroxyacrylamide. The water-soluble polymers can be used alone or in combination of two or more. The polishing composition disclosed herein can also be preferably implemented in an embodiment that is substantially free of water-soluble polymers, that is, an embodiment that does not intentionally contain water-soluble polymers.

[0175] When the composition for polishing is used as a polishing liquid as it is, the content of the water-soluble polymer is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more with respect to the composition for polishing. Further, when the composition for polishing is used as a polishing liquid as it is, 3% by mass or less is preferable, 2% by mass or less is more preferable, and 1% by mass or less is even more preferable. In addition, when two or more water-soluble polymers are used in combination, the above content refers to the total content of two or more water-soluble polymers.

[0176] Since the pH adjuster and the solvent are the same as those defined in the above <pH adjuster ((D) component)> and <solvent> sections respectively, the description thereof is omitted here. Among these, the pH adjuster is preferably potassium hydroxide, sodium hydroxide, or ammonia, and more preferably ammonia. Further, the solvent preferably contains water, and more preferably is only water.

[0177] When the composition for polishing is used as a polishing liquid as it is, the pH of the composition for polishing is preferably higher than (exceeding 8.0) the pH of the surface treatment composition according to the present invention, more preferably 8.5 or more, even more preferably 9.5 or more, and particularly preferably 10.0 or more. When the pH of the composition for polishing increases, the polishing rate increases. On the other hand, when the composition for polishing is used as a polishing liquid as it is, the pH of the composition for polishing is preferably 12.0 or less, and more preferably 11.5 or less. If the pH of the composition for polishing is 12.0 or less, dissolution of the abrasive grains can be suppressed, and a decrease in the mechanical polishing action by the abrasive grains can be prevented. The pH of the composition for polishing is the value measured by the method described in the examples.

[0178] As the polishing apparatus, a general polishing apparatus having a polishing platen to which a holder for holding the polishing object and a motor or the like capable of changing the rotation speed are attached and to which a polishing pad (polishing cloth) can be attached can be used. As the polishing apparatus, either a single-sided polishing apparatus or a double-sided polishing apparatus may be used. [[ID=!4]]

[0179] The polishing pad can be made of any material, including ordinary nonwoven fabric, polyurethane, porous fluororesin, etc. The polishing pad is preferably provided with grooves to allow the polishing liquid to accumulate.

[0180] There are no particular restrictions on the polishing conditions. For example, the rotation speed of the polishing table and the head (carrier) are 10 rpm (0.17 s -1 ) or more 100rpm(1.67s -1 ) or less, and the pressure applied to the object to be polished (polishing pressure) is preferably 0.5 psi (3.4 kPa) or more and 10 psi (68.9 kPa) or less. The method of supplying the polishing composition to the polishing pad is not particularly limited, and for example, a method of continuously supplying it using a pump or the like (flowing) is used. There is no limit to the amount of supply, but it is preferable that the surface of the polishing pad is always covered with the polishing composition, and it is preferably 10 mL / min or more and 5000 mL / min or less. The polishing time is also not particularly limited, but it is preferably 5 seconds or more and 180 seconds or less for the step using the polishing composition.

[0181] <Surface treatment process> The surface treatment step refers to a step of reducing residues on the surface of a polished object using the surface treatment composition of the present invention. In the method for producing a semiconductor substrate, a cleaning step may be performed as a surface treatment step after the rinse-polishing step, or only the rinse-polishing step or only the cleaning step may be performed.

[0182] (Rinse polishing process) The rinse-polishing step may be performed between the polishing step and the cleaning step in the method for manufacturing a semiconductor substrate. The rinse-polishing step is a step for reducing foreign matter on the surface of a polished object (polished semiconductor substrate) by a surface treatment method (rinse-polishing method) according to one embodiment of the present invention.

[0183] Details of the rinse polishing method used in the rinse polishing step are as described above in the explanation of the rinse polishing treatment.

[0184] (Cleaning process) In the method for manufacturing a semiconductor substrate, the cleaning step may be performed after the polishing step or after the rinse-polishing step. The cleaning step is a step of reducing foreign matter on the surface of a polished object (polished semiconductor substrate) by a surface treatment method (cleaning method) according to one embodiment of the present invention.

[0185] The details of the cleaning method used in the cleaning step are the same as those described above (post-cleaning treatment). [Example]

[0186] The present invention will be described in more detail using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. Unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass," respectively. In the following examples, unless otherwise specified, the operations were carried out under the conditions of room temperature (25°C) and a relative humidity of 40% RH or more and 50% RH or less.

[0187] [Preparation of components (A) to (D)] The following components (A) to (D) were prepared.

[0188] <Component (A): Quaternary nitrogen-containing onium salt compound> Lauryl dimethyl benzyl ammonium chloride, molecular weight 340: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Catiogen (registered trademark) BC-50 Dodecylethyldimethylammonium ethyl sulfate, molecular weight 368: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Catiogen (registered trademark) ES-L Methyltri-n-octylammonium chloride, molecular weight 404: Fujifilm Wako Pure Chemical Industries, Ltd. Trimethylstearylammonium chloride, molecular weight 348: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Catiogen (registered trademark) TMS Dioleyldimethylammonium chloride, molecular weight 582: NOF Corporation, product name: NissanCation (registered trademark) 2-OLR 1-Methyl-1-hydroxyethyl-2-tallow alkyl-imidazonium chloride: manufactured by NOF Corporation, product name: NissanCation (registered trademark) AR-4.

[0189] <Component (A'): Other salt compounds> Tetradecylamine acetate, molecular weight 273: manufactured by NOF Corporation, product name: NissanCation (registered trademark) MA.

[0190] <Component (B): Nonionic polymer> Polyvinyl alcohol (PVA), Mw=10,000: manufactured by Nippon Vinyl Acetate & Poval Co., Ltd., product name: JMR (registered trademark)-10HH Polyvinyl alcohol (PVA), Mw=5,000: manufactured by Nippon Vinyl Acetate & Poval Co., Ltd., product name: JMR (registered trademark)-3HH Polyvinylpyrrolidone (PVP), Mw=45,000: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Pitzcol (registered trademark) K30A.

[0191] <Component (B'): Other polymers> Ammonium polyacrylate (PAA), Mw=6,000: Toagosei Co., Ltd., product name: A-30SL Polyethyleneimine, Mw=10,000: manufactured by Nippon Shokubai Co., Ltd., product name: EPOMIN (registered trademark) SP-200.

[0192] <Component (C): pH buffer> Ammonium acetate, molecular weight 77: manufactured by Kanto Chemical Co., Ltd.

[0193] <Component (C'): Other pH buffers> Diammonium hydrogen phosphate, molecular weight 132: Fujifilm Wako Pure Chemical Industries, Ltd. Ammonium bicarbonate, molecular weight 79: Fujifilm Wako Pure Chemical Industries, Ltd.

[0194] <Component (D): pH adjuster> Ammonia, molecular weight 17: Kanto Chemical Co., Ltd., product name: EL aqueous ammonia.

[0195] The weight average molecular weight (Mw) of the above components (B) and (B') was measured by the following method.

[0196] [Measurement of weight average molecular weight (Mw)] The weight average molecular weight (Mw) of the components (B) and (B') was measured by gel permeation chromatography (GPC) using the following apparatus and conditions: GPC equipment: Shimadzu Corporation Model: Prominence + ELSD detector (ELSD-LTII) Column: VP-ODS (Shimadzu Corporation) Mobile phase A:MeOH B: 1% aqueous solution of acetic acid Flow rate: 1mL / min Detector: ELSD temp. 40℃, Gain 8, N2GAS 350kPa Oven temperature: 40°C Injection volume: 40μL.

[0197] [Measurement of pH of surface treatment composition] The pH of the surface treatment composition (liquid temperature: 25°C) was confirmed using a pH meter (product name: LAQUA (registered trademark), manufactured by Horiba, Ltd.) The pH of the polishing composition described below was also measured using the same method.

[0198] [Preparation of surface treatment composition] Example 1 Surface treatment composition 1 was prepared by mixing and stirring lauryl dimethyl benzyl ammonium chloride as component (A), polyvinyl alcohol (Mw=10,000) as component (B), ammonium acetate as component (C), ammonia as component (D), and distilled water as a solvent at 25°C for 5 minutes.

[0199] Here, the content of each component was as follows: relative to the total amount of surface treatment composition 1, the content of component (A) was 0.01 mass% (0.1 g / L), the content of component (B) was 0.10 mass% (1 g / L), the content of component (C) was 0.25 mass% (2.5 g / L), and the content of component (D) (pH adjuster) was an amount such that the pH of surface treatment composition 1 was 9.0.

[0200] Examples 2 and 3 Surface treatment compositions 2 and 3 were each prepared in the same manner as in Example 1, except that the content (addition amount) of component (D) was changed so that the pH of each surface treatment composition would be the value shown in Table 1 below.

[0201] Example 4 Surface treatment composition 4 was prepared in the same manner as in Example 1, except that the content of component (A) was changed as shown in Table 1 below.

[0202] Example 5 Surface treatment composition 5 was prepared in the same manner as in Example 1, except that the content of component (B) was changed as shown in Table 1 below.

[0203] Example 6 Surface treatment composition 6 was prepared in the same manner as in Example 1, except that polyvinyl alcohol (Mw=10,000) as component (B) was changed to polyvinyl alcohol (Mw=5,000).

[0204] Example 7 Surface treatment composition 7 was prepared in the same manner as in Example 1, except that polyvinyl alcohol (Mw=10,000) as component (B) was changed to polyvinylpyrrolidone (Mw=45,000).

[0205] Example 8 Surface treatment composition 8 was prepared in the same manner as in Example 1, except that lauryldimethylbenzylammonium chloride as component (A) was changed to dodecylethyldimethylammonium ethyl sulfate.

[0206] Example 9 Surface treatment composition 9 was prepared in the same manner as in Example 4, except that lauryldimethylbenzylammonium chloride as component (A) was changed to dodecylethyldimethylammonium ethyl sulfate.

[0207] Example 10 A surface treatment composition 10 was prepared in the same manner as in Example 7, except that lauryldimethylbenzylammonium chloride as component (A) was changed to dodecylethyldimethylammonium ethyl sulfate.

[0208] (Examples 11, 13, 15 and 17) Surface treatment compositions 11, 13, 15 and 17 were prepared in the same manner as in Example 1, except that lauryldimethylbenzylammonium chloride as component (A) was changed as shown in Table 1.

[0209] (Examples 12, 14, 16 and 18) Surface treatment compositions 12, 14, 16 and 18 were prepared in the same manner as in Example 7, except that lauryldimethylbenzylammonium chloride as component (A) was changed as shown in Table 1.

[0210] (Comparative Example 1) Surface treatment composition 19 was prepared by mixing lauryl dimethyl benzyl ammonium chloride as component (A), ammonia as component (D), and distilled water as a solvent at 25° C. with stirring for 5 minutes.

[0211] Here, the content of each component was as follows: the content of component (A) was 0.01 mass% (0.1 g / L) relative to the total amount of surface treatment composition 19, and the content of component (D) was an amount such that the pH of surface treatment composition 19 was 9.0.

[0212] (Comparative Example 2) Surface treatment composition 20 was prepared by mixing polyvinyl alcohol (Mw=10,000) as component (B), ammonia as component (D), and distilled water as a solvent at 25° C. with stirring for 5 minutes.

[0213] Here, the content of each component was as follows: the content of component (B) was 0.10 mass% (1 g / L) relative to the total amount of surface treatment composition 20, and the content of component (D) was an amount such that the pH of surface treatment composition 20 was 9.0.

[0214] (Comparative Examples 3 to 5) Surface treatment compositions 21 to 23 were prepared in the same manner as in Example 1, except that component (B), component (A) and component (C) were not added.

[0215] (Comparative Examples 6 and 7) Surface treatment compositions 24 and 25 were prepared in the same manner as in Example 1, except that the ammonium acetate used as component (C) was changed as shown in Table 1 and the amount added was changed as shown in Table 1.

[0216] (Comparative Example 8) Surface treatment composition 26 was prepared in the same manner as in Example 1, except that lauryldimethylbenzylammonium chloride as component (A) was changed to tetradecylamine acetate.

[0217] Comparative Example 9 Surface treatment composition 27 was prepared in the same manner as in Example 7, except that lauryldimethylbenzylammonium chloride as component (A) was changed to tetradecylamine acetate.

[0218] (Comparative Examples 10 and 11) Surface treatment compositions 28 and 29 were prepared in the same manner as in Example 1, except that the polyvinyl alcohol (Mw=10,000) used as component (B) was changed as shown in Table 1. Note that the components contained in surface treatment composition 28 aggregated, making it impossible to carry out the evaluation described below.

[0219] The surface treatment compositions 1 to 29 prepared above do not contain abrasive grains (abrasive grain content=0 mass %).

[0220] [Table 1-1]

[0221] [Table 1-2]

[0222] [Preparation of polished object] Polished objects (polished SiN substrates, polished Poly-Si substrates) were prepared after being polished by the following chemical mechanical polishing (CMP) process.

[0223] (CMP process) The objects to be polished were a silicon wafer (SiN substrate) (300 mm blanket wafer, manufactured by Advantec Co., Ltd.) with a 2500 Å thick SiN film formed on its surface by CVD, and a silicon wafer (Poly-Si substrate) (300 mm wafer, manufactured by Advanced Materials Technology Co., Ltd.) with a 5000 Å thick polycrystalline silicon film formed on its surface by CVD.

[0224] The SiN substrates and Poly-Si substrates prepared above were polished using the polishing compositions having the following compositions under the following conditions to obtain polished objects (polished SiN substrates and polished Poly-Si substrates).

[0225] <Polishing composition> A silica slurry (composition: 10 mass% colloidal silica (average primary particle size: 35 nm, average secondary particle size: 70 nm), 0.25 mass% polyvinylpyrrolidone (Pitzcol (registered trademark) K30A, Dai-ichi Kogyo Seiyaku Co., Ltd., Mw=45,000), 0.33 mass% EL aqueous ammonia (concentration: 28.0% to 30.0% (as NH3) (Kanto Chemical Co., Inc.) as NH3, solvent: distilled water) was prepared. The silica slurry was diluted 5 times with distilled water to prepare a polishing composition. The pH of the resulting polishing composition was 10.0.

[0226] <Polishing equipment and polishing conditions> Polishing equipment: Ebara Corporation FREX300E Polishing pad: Polyurethane foam pad manufactured by Fujibo Holdings Co., Ltd. H800-Type1 Conditioner (dresser): Nylon brush (3M) Polishing pressure: 2.0 psi (1 psi = 6894.76 Pa, same below) Polishing platen rotation speed: 80 rpm Head rotation speed: 80 rpm Supply of polishing composition: free-flowing Polishing composition supply amount: 200mL / min Polishing time: 30 seconds.

[0227] [Rinse polishing] After the surfaces of the objects to be polished (SiN substrate, Poly-Si substrate) were polished in the CMP process, the polished objects (polished SiN substrate, polished Poly-Si substrate) were removed from the polishing table (platen). Subsequently, in the same polishing apparatus, the polished objects were mounted on another polishing table (platen), and the polished surfaces were subjected to a rinse polishing treatment using each of the surface treatment compositions 1 to 29 prepared in the above Examples and Comparative Examples under the following conditions.

[0228] <Rinse polishing equipment and rinse polishing conditions> Polishing equipment: Ebara Corporation FREX300E Polishing pad: Polyurethane foam pad manufactured by Fujibo Holdings Co., Ltd. H800-Type1 Conditioner (dresser): Nylon brush (3M) Grinding pressure: 1.0 psi Plate rotation speed: 80 rpm Head rotation speed: 80 rpm Supply of polishing composition: free-flowing Surface treatment composition supply rate: 300 mL / min Polishing time: 60 seconds.

[0229] [Post-cleaning process] After the rinse-polishing treatment, the substrate surface was brush-cleaned using a 0.3% NH3 aqueous solution for 20 seconds, and then rinsed with deionized water for 40 seconds to obtain rinse-polished polished objects (rinse-polished SiN substrates 1 to 29 using the surface treatment compositions 1 to 29 of the Examples and Comparative Examples, and rinse-polished Poly-Si substrates 1 to 29 using the surface treatment compositions 1 to 29 of the Examples and Comparative Examples).

[0230] [evaluation] (Residue evaluation) Under alkaline conditions, many hydroxyl groups are present on the surface of a Poly-Si substrate, forming a water film on the surface. As a result, defects (e.g., abrasive grain residue, pad debris, and organic residues such as polymers) are less likely to adhere to the surface of a Poly-Si substrate, or do not adhere at all. On the other hand, defects (e.g., abrasive grain residue, pad debris, and organic residues such as polymers) are more likely to adhere to SiN substrates. For this reason, in this evaluation, the number of abrasive grain residues and organic residues (pad debris, polymers, etc.) on rinse-polished SiN substrates (SiN substrates after rinse-polishing) were measured according to the following method. The results are shown in Table 2 below ("Number of defects on SiN" in the table).

[0231] The number of residues on the surface of rinse-polished SiN substrates (polished SiN substrates after rinse-polishing) was evaluated using a Surfscan® SP5 optical inspection system manufactured by KLA-Tencor Corporation. Specifically, the number of residues exceeding 50 nm in diameter was counted on the remaining area of ​​one side of the rinse-polished SiN substrate, excluding a 5 mm wide area from the outer edge (the area from 0 mm to 5 mm, assuming the outer edge is 0 mm). The number of abrasive grain residues and organic residues on the rinse-polished SiN substrates was then measured by SEM observation using a Review SEM RS6000 manufactured by Hitachi High-Tech Corporation. First, 100 residues present on the remaining area, excluding a 5 mm wide area from the outer edge of one side of the rinse-polished SiN substrate, were sampled for SEM observation. Next, the type of residue (abrasive grain or organic residue) was determined from the 100 sampled residues by visual observation using an SEM, and the number of abrasive grain residues (SiO2 residues) and organic residues (pad debris, polymers, etc.) was measured. The number of abrasive grain residues (SiO2 residues) is preferably as low as possible, but 30 or less is acceptable, preferably 25 or less, and more preferably less than 20. The number of organic residues (pad debris, polymers, etc.) is also preferably as low as possible, but less than 15 is acceptable, preferably 10 or less, and more preferably 5 or less.

[0232] (Evaluation of zeta potential of abrasive grains) The zeta potential of the abrasive grains (colloidal silica, SiO2) in each surface treatment composition was measured according to the following method, and the results are shown in Table 2 below ("Zeta potential abrasive grains [mV]" in the table).

[0233] The zeta potential of the abrasive grains was measured using a Zetasizer Nano ZSP manufactured by Spectris Co., Ltd. (Malvern Division). The zeta potential of the abrasive grains during rinse polishing using the surface treatment composition was measured in the following model experiment.

[0234] A silica (SiO2) particle dispersion (colloidal silica, average primary particle diameter: 35 nm, average secondary particle diameter: 70 nm, 19.5 mass% aqueous dispersion) was added to each surface treatment composition so that the silica particle concentration was 0.02 mass%, to prepare a measurement solution with a silica particle concentration of 0.02 mass% (the content (concentration) of silica particles in the measurement solution was 0.02 mass% relative to the total mass of the measurement solution). The resulting measurement solution was filled into the measurement cell of the above-mentioned device (Zetasizer Nano ZSP), and the zeta potential (mV) of the abrasive grains was measured. A zeta potential (mV) of 30 mV or higher of the abrasive grains is acceptable.

[0235] (Evaluation of zeta potential of SiN substrate and pad debris) The zeta potential of silicon nitride (SiN substrate) and pad scraps (polyurethane) in each surface treatment composition was measured. The results are shown in Table 2 below ("Zeta potential SiN [mV]" and "Zeta potential pad scraps [mV]" in the table). It is presumed that the zeta potential of silicon nitride has a greater impact on the residue removal effect than the zeta potential of polycrystalline silicon. For this reason, in this evaluation, the zeta potential of the SiN substrate in the surface treatment composition was measured.

[0236] The zeta potential of the polished SiN substrate and the zeta potential of the pad waste are values ​​measured using a solid-state zeta potential measuring instrument SurPASS3 (zeta potential meter) manufactured by Anton Paar Japan Co., Ltd. The zeta potential of the polished SiN substrate surface during rinse polishing using the surface treatment composition and the zeta potential of the pad waste during rinse polishing using the surface treatment composition are values ​​measured in the following model experiment.

[0237] To measure the zeta potential of the polished SiN substrate surface, a silicon wafer (SiN substrate) (300 mm blanket wafer, manufactured by Advantec Co., Ltd.) with a 2500 Å thick SiN film formed on its surface by CVD was cut into 60 mm square pieces and used as the measurement object.

[0238] To measure the zeta potential of the pad waste, a polyurethane pad (Fujibo Holdings Co., Ltd., foam polyurethane pad, H800-Type1) was cut into a 60 mm square and used as the measurement object.

[0239] Each of these measurement objects was placed in a zeta potential meter, and the surface treatment composition prepared above was then passed through the measurement objects to measure the zeta potential (mV) of each of these measurement objects.

[0240] (Etching rate evaluation) The etching rates of polished SiN substrates during rinse-polishing using each surface treatment composition, and the etching rates of polished Poly-Si substrates during rinse-polishing using each surface treatment composition, were measured in the following model experiments. These values ​​are shown in Table 2 below ("SiN [Å / min]" and "Poly-Si [Å / min]" in the table).

[0241] To measure the etching rate of the polished SiN substrate, a silicon wafer (SiN substrate) (300 mm blanket wafer, manufactured by Advantec Co., Ltd.) with a 2500 Å thick SiN film formed on its surface by CVD was cut into 60 mm square pieces and used as the measurement object.

[0242] To measure the etching rate of the polished Poly-Si substrate, a silicon wafer (Poly-Si substrate) (300 mm, manufactured by Advanced Materials Technology Co., Ltd.) with a 5000 Å thick polycrystalline silicon film formed on its surface by CVD was cut into 60 mm square pieces and used as the measurement object.

[0243] The thickness of each of these measurement objects was measured using an optical film thickness meter (Lambda Ace VM-2030, manufactured by Dainippon Screen Mfg. Co., Ltd.) (thickness before immersion (Å)). Next, each of these measurement objects was immersed in the surface treatment composition prepared above for 30 minutes. After the predetermined time of immersion, the thickness of each measurement object was measured using an optical film thickness meter (Lambda Ace VM-2030, manufactured by Dainippon Screen Mfg. Co., Ltd.) (thickness after immersion (Å)). The etching rate [= (thickness before immersion (Å) - thickness after immersion (Å)) / immersion time (min)] was calculated by dividing the difference in thickness before and after immersion by the immersion time (min). Note that the etching rate of the polished SiN substrate is preferably as low as possible, but an etching rate of less than 15 Å / min is acceptable, preferably less than 10 Å / min, and more preferably less than 8 Å / min.

[0244] (ΔpH evaluation) The difference in pH (ΔpH) between the surface treatment composition before and after the rinse-polishing of a SiN substrate as the polishing object was measured [= (pH of the surface treatment composition after rinse-polishing) - (pH of the surface treatment composition before rinse-polishing)]. The pH of the surface treatment composition before rinse-polishing is the pH of the surface treatment composition listed in Table 1 above. These values ​​are shown in Table 2 below ("ΔpH[-]" in the table). The ΔpH (pH change before and after rinse-polishing) is preferably as small as possible, but a value of less than 1.0 is acceptable, preferably less than 0.8, and more preferably less than 0.3.

[0245] [Table 2-1]

[0246] [Table 2-2]

[0247] As is clear from Table 2 above, the surface treatment compositions of the Examples can sufficiently remove residues from SiN substrates compared to the surface treatment compositions of the Comparative Examples. Furthermore, the surface treatment compositions of the Examples can reduce the etching rate for Poly-Si substrates. While the above results are based on evaluations performed immediately after the surface treatment compositions were produced, it is preferable to include a mildewcide (preservative) when storing or preserving the compositions for long periods of time. Since mildewcide (preservative) has little or no effect on the results, it is believed that a surface treatment composition containing a mildewcide (preservative) would also produce similar results.

[0248] Furthermore, Table 2 above shows the difference in pH (ΔpH) between the surface treatment compositions before and after rinse-polishing of a SiN substrate as the object to be polished. The difference in pH between the surface treatment compositions before and after rinse-polishing of a Poly-Si substrate or a TEOS film as the object to be polished was equivalent to the difference in pH between the surface treatment compositions before and after rinse-polishing of a SiN substrate as the object to be polished.

Claims

1. A surface treatment composition comprising the following components (A) to (C), having a pH of greater than 7.0, and used for at least one of a rinse polishing treatment and a cleaning treatment, the surface treatment composition satisfying at least one of the following (i) to (iii): Component (A): A quaternary nitrogen-containing onium salt compound having at least one of a linear or branched alkyl group having 7 or more carbon atoms and a linear or branched alkenyl group having 7 or more carbon atoms. Component (B): nonionic polymer (C) Component: Formula: A-COO － NH ４ ＋ (A is an alkyl group having 1 to 10 carbon atoms or a phenyl group); (i) the mass ratio of the component (A) to the component (C) is 0.01 or more and 1.0 or less; (ii) the mass ratio of the component (A) to the component (B) is 0.01 or more and 200 or less; (iii) The weight-average molecular weight of the nonionic polymer is 10,000 or more.

2. 2. The surface treatment composition according to claim 1, wherein the quaternary nitrogen-containing onium salt compound is a quaternary ammonium salt compound represented by the following formula (a): 【Chemical 1】 In the above formula (a), R １１ is a linear or branched alkyl group having 9 to 15 carbon atoms, R １２ , R １３ and R １４ are each independently a linear or branched alkyl group having from 1 to 6 carbon atoms or a benzyl group; X is an anion.

3. 3. The surface treatment composition according to claim 1, wherein the nonionic polymer comprises at least one selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, poly-N-vinylacetamide, polyethylene glycol, hydroxyethyl cellulose, and butenediol-vinyl alcohol copolymer.

4. The surface treatment composition according to any one of claims 1 to 3, wherein the buffer is ammonium acetate.

5. The surface treatment composition according to any one of claims 1 to 4, which is substantially free of abrasive grains.

6. The surface treatment composition according to any one of claims 1 to 5, further comprising the following component (D): component (D): a pH adjuster.

7. The surface treatment composition according to claim 6, wherein the pH adjuster is ammonia.

8. A surface treatment method comprising: treating a polished object containing at least one selected from the group consisting of silicon nitride, silicon oxide, and polysilicon with the surface treatment composition according to any one of claims 1 to 7, thereby reducing residues on the surface of the polished object.

9. The surface treatment method according to claim 8, which is a rinse polishing treatment method or a cleaning treatment method.

10. the polished object is a polished semiconductor substrate, a polishing step of polishing an unpolished semiconductor substrate containing at least one selected from the group consisting of silicon nitride, silicon oxide, and polysilicon with a polishing composition containing abrasive grains to obtain a polished semiconductor substrate; a surface treatment step of reducing residues containing the abrasive grains on the surface of the polished semiconductor substrate using the surface treatment composition according to any one of claims 1 to 7; A method for manufacturing a semiconductor substrate, comprising:

11. The method for producing a semiconductor substrate according to claim 10, wherein the polishing composition has a pH of 8.5 or higher.

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