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

Abstract

To provide means capable of sufficiently removing residue remaining on the surface of a polished object containing silicon nitride and at least one member selected from the group consisting of silicon oxide and polysilicon.SOLUTION: A surface treatment composition includes a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, and an anionic polymer, and the weight average molecular weight of the nitrogen-free nonionic polymer is less than 100,000, the ratio of the weight average molecular weight of the nitrogen-containing nonionic polymer to the weight average molecular weight of the nitrogen-free nonionic polymer (nitrogen-containing nonionic polymer / nitrogen-free nonionic polymer) is 0.1 or more and 10 or less, and pH is less than 7.0.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 increasing number of multilayer wirings 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 for silicon wafers that contains a water-soluble polymer that satisfies specific conditions, and discloses that this composition can remove foreign matter from silicon wafers after polishing and reduce defects in the silicon wafers after polishing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-167237 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the technology of Patent Document 1 had a problem in that it was unable to sufficiently remove foreign matter (residue) when cleaning a polished object containing silicon nitride and at least one selected from the group consisting of silicon oxide and polysilicon.

[0008] Therefore, an object of the present invention is to provide a means capable of sufficiently removing residues remaining on the surface of a polished object containing silicon nitride and at least one selected from the group consisting of silicon oxide and polysilicon. [Means for solving the problem]

[0009] In view of the above-mentioned problems, the present inventors have conducted extensive research and found that the above-mentioned problems can be solved by a surface treatment composition comprising a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, and an anionic polymer, wherein the weight-average molecular weight of the nitrogen-free nonionic polymer is less than 100,000, the ratio of the weight-average molecular weight of the nitrogen-containing nonionic polymer to the weight-average molecular weight of the nitrogen-free nonionic polymer (nitrogen-containing nonionic polymer / nitrogen-free nonionic polymer) is 0.1 or more and 10 or less, and the pH is less than 7.0, thereby completing the present invention. [Effects of the Invention]

[0010] According to the present invention, there is provided a means capable of sufficiently removing residue remaining on the surface of a polished object containing silicon nitride and at least one selected from the group consisting of silicon oxide and polysilicon. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention provides a surface treatment composition comprising a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, and an anionic polymer, wherein the weight-average molecular weight of the nitrogen-free nonionic polymer is less than 100,000, the ratio of the weight-average molecular weight of the nitrogen-containing nonionic polymer to the weight-average molecular weight of the nitrogen-free nonionic polymer (nitrogen-containing nonionic polymer / nitrogen-free nonionic polymer) is 0.1 or more and 10 or less, and the pH is less than 7.0. The surface treatment composition of the present invention can sufficiently remove residue remaining on the surface of a polished object containing silicon nitride and at least one selected from the group consisting of silicon oxide and polysilicon. In this specification, the polished object refers to the object after being polished with the polishing composition. In the present invention, the polished object contains silicon nitride and at least one selected from the group consisting of silicon oxide and polysilicon. A polished object containing silicon nitride means that the polished object has a film (layer) containing silicon nitride, a polished object containing silicon oxide means that the polished object has a film (layer) containing silicon oxide, and a polished object containing polysilicon means that the polished object has a film (layer) containing polysilicon. That is, the polished object according to the present invention has a film (layer) containing silicon nitride and a film (layer) containing at least one material selected from the group consisting of silicon oxide and polysilicon. Hereinafter, a "polished object containing silicon nitride and at least one material selected from the group consisting of silicon oxide and polysilicon" may be simply referred to as a "polished object."

[0012] The present inventors speculate that the mechanism by which the above-described configuration can remove residues from the surface of a polished object is as follows.

[0013] That is, the components contained in the surface treatment composition act on the surface of the polished object, thereby removing residue from the surface of the polished object. Specifically, the nitrogen-containing nonionic polymer, the nitrogen-free nonionic polymer, and the anionic polymer are adsorbed onto the surface of the polished object, thereby removing residue that was present on the surface of the polished object. The inventors have found that, in removing these residues, residues on the surface of the polished object can be more efficiently removed by using a pH of less than 7.0, a weight-average molecular weight of the nitrogen-free nonionic polymer of less than 100,000, and a ratio of the weight-average molecular weight of the nitrogen-containing nonionic polymer to the weight-average molecular weight of the nitrogen-free nonionic polymer (nitrogen-containing nonionic polymer / nitrogen-free nonionic polymer) of 0.1 or more and 10 or less. Although the details of these mechanisms are unknown, it is believed that the above configuration makes it easier for the nitrogen-free nonionic polymer, the nitrogen-containing nonionic polymer, and the anionic polymer to be more effectively adsorbed onto the polished object, thereby more efficiently removing residues from the surface of the polished object and preventing the residues (contaminants) from re-adhering to the surface of the polished object.

[0014] Anionic polymers are easily adsorbed onto silicon nitride-containing films, and the surface treatment composition of the present invention can effectively exhibit the above-mentioned effects on silicon nitride-containing films. Nitrogen-containing nonionic polymers are easily adsorbed onto silicon oxide-containing films and / or polysilicon-containing films, and the surface treatment composition of the present invention can effectively exhibit the above-mentioned effects on silicon oxide-containing films and / or polysilicon-containing films. Furthermore, nitrogen-containing nonionic polymers easily interact with nitrogen-free nonionic polymers. For example, hydrogen bonds can be formed between nitrogen atoms of the nitrogen-containing nonionic polymer and oxygen atoms of the nitrogen-free nonionic polymer, forming a hydrophilic film on the silicon oxide-containing film and / or polysilicon-containing film, thereby further enhancing the above-mentioned effects. Furthermore, nitrogen atoms of the nitrogen-containing nonionic polymer can form hydrogen bonds with hydroxyl groups present on the surface of the silicon oxide-containing film, thereby allowing for particularly effective adsorption onto the silicon oxide-containing film, thereby further enhancing the above-mentioned effects.

[0015] Furthermore, by adopting the above-mentioned composition, the components (nitrogen-containing nonionic polymer, nitrogen-containing nonionic polymer, and nitrogen-free nonionic polymer) adsorbed on the polished surface of the object to be polished can be easily desorbed from the surface of the object to be polished, and the components adsorbed on the surface of the object to be polished can be hardly or not left as residues. From the above, it is considered that the surface treatment composition of the present invention can sufficiently remove residues.

[0016] The above mechanism is based on speculation, and the present invention is not limited to the above mechanism in any way.

[0017] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to only the following embodiments. Unless otherwise specified, in this specification, 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.

[0018] <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, organic residues described below, particle residues derived from abrasive grains contained in the polishing composition, residues consisting of components other than particle residues and organic residues, and other residues such as a mixture of particle residues and organic residues.

[0019] 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 system (optical inspection machine Surfscan® SP5; manufactured by KLA-Tencor Corporation). Details of the method for measuring the number of residues will be described in the Examples below.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] <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.

[0024] The polished object (object to be polished) according to the present invention comprises silicon nitride (SiN) and at least one selected from the group consisting of silicon oxide (SiO2) and polysilicon (polycrystalline silicon). In a preferred embodiment of the present invention, the polished object (object to be polished) comprises silicon nitride (SiN), silicon oxide (SiO2), and polysilicon (polycrystalline silicon).

[0025] The material contained in the object to be polished according to the present invention is not particularly limited as long as it contains silicon nitride (SiN) and at least one selected from the group consisting of silicon oxide (SiO) and polysilicon (polycrystalline silicon), and may further contain, for example, carbon-containing silicon such as silicon carbonitride (SiCN), non-crystalline silicon, silicon material doped with impurities, elemental metal, alloy, metal nitride, compound semiconductor such as SiGe, etc.

[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 silicon oxide-containing films contained in the polished object 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 nitride. According to a preferred embodiment of the present invention, the hydrophilic material is silicon nitride and silicon oxide. 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 nitride and the hydrophobic material is polycrystalline silicon. Also, according to a preferred embodiment of the present invention, the hydrophilic material is silicon nitride and silicon oxide and the hydrophobic material is polycrystalline silicon.

[0031] <Surface treatment composition> The surface treatment composition according to the present invention comprises a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, and an anionic polymer. In this specification, the term "polymer" refers to a compound having a weight-average molecular weight (Mw) of 1,000 or more. In this specification, the term "nonionic polymer" 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. The term "anionic polymer" refers to a polymer that contains anionic groups such as carboxylic acid groups, sulfonic acid groups, or phosphate groups within the molecule. Each of these polymers will be described below.

[0032] (Nitrogen-free nonionic polymer) The nitrogen-free nonionic polymer contained in the surface treatment composition of the present invention has a weight-average molecular weight of less than 100,000. If the weight-average molecular weight of the nitrogen-free nonionic polymer is 100,000 or more, the nitrogen-free nonionic polymer will remain on the surface of the polished object even after final cleaning, and will itself become a defect. As will be described later, the nitrogen-containing nonionic polymer is also characterized by a ratio of the weight-average molecular weight of the nitrogen-containing nonionic polymer falling within a specific range. By having the weight-average molecular weight of the nitrogen-free nonionic polymer fall within the above range, the nitrogen-free nonionic polymer is more easily adsorbed onto the polished object, allowing for efficient removal of residue.

[0033] The weight-average molecular weight of the nitrogen-free nonionic polymer is preferably 1,500 or more, more preferably 2,000 or more, even more preferably 3,000 or more, still more preferably 4,500 or more, particularly preferably 5,500 or more, and most preferably 7,500 or more.The weight-average molecular weight of the nitrogen-free nonionic polymer is preferably 95,000 or less, more preferably 90,000 or less, even more preferably 80,000 or less, still more preferably 50,000 or less, particularly preferably 30,000 or less, particularly preferably 25,000 or less, and most preferably 20,000 or less. That is, the weight-average molecular weight of the nitrogen-free nonionic polymer is preferably 1,500 to 95,000, more preferably 2,000 to 90,000, even more preferably 3,000 to 80,000, even more preferably 4,500 to 50,000, particularly preferably 5,500 to 30,000, particularly preferably 7,500 to 25,000, and most preferably 7,500 to 20,000. When the weight-average molecular weight of the nitrogen-free nonionic polymer is within the above range, residues on the surface of the polished object after treatment with the surface treatment composition can be more efficiently removed, and the desired effects of the present invention can be more effectively achieved. In this specification, the weight-average molecular weight (Mw) of polymers such as nitrogen-free nonionic polymers, nitrogen-containing nonionic polymers, and anionic polymers can be measured as a polyethylene glycol equivalent value using gel permeation chromatography (GPC).

[0034] When the weight-average molecular weight of the nitrogen-free nonionic polymer is within the above range, the nitrogen-free nonionic polymer is more easily adsorbed onto the polished object (e.g., a film containing polysilicon), and residues on the surface of the polished object can be more efficiently removed after treatment with the surface treatment composition, thereby better achieving the desired effects of the present invention.

[0035] The nitrogen-free nonionic polymer may be a nonionic polymer that does not have a nitrogen atom, but is preferably a nonionic polymer that does not have a nitrogen atom and has an oxygen atom. Examples of nitrogen-free nonionic polymers include polyvinyl alcohol, polyvinyl ethers (polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl isobutyl ether, etc.), polyalkylene oxides (polyethylene oxide, polypropylene oxide, polybutylene oxide, etc.), polyglycerin, polyethylene glycol, polypropylene glycol, polybutylene glycol, water-soluble polysaccharides such as hydroxyethyl cellulose, alginic acid polyhydric alcohol esters, water-soluble urea resins, dextrin derivatives, casein, etc. In addition to those having the above-mentioned main chain structure, graft copolymers having a nonionic polymer structure in the side chain can also be suitably used as nitrogen-free nonionic polymers. The non-nitrogen-containing nonionic polymer may be a polymer having the same (homopolymer) or different (copolymer) repeating structural units, and when the non-nitrogen-containing nonionic polymer is a copolymer, the copolymer may be in the form of a block copolymer, a random copolymer, a graft copolymer, or an alternating copolymer.

[0036] The non-nitrogen-containing nonionic polymer is preferably polyvinyl alcohol, polyethylene glycol, polypropylene glycol, or hydroxyethyl cellulose, more preferably polyvinyl alcohol. Two or more types of non-nitrogen-containing nonionic polymers may be used in combination.

[0037] The content of the nitrogen-free nonionic polymer in the surface treatment composition is preferably 0.001% by mass to 10% by mass, more preferably 0.005% by mass to 5% by mass, even more preferably 0.07% by mass to 3% by mass, particularly preferably 0.01% by mass to 1% by mass, and most preferably 0.01% by mass to 0.5% by mass. When the surface treatment composition contains two or more types of nitrogen-free nonionic polymers, the content of the nitrogen-free nonionic polymers is the total amount of these.

[0038] (Nitrogen-containing nonionic polymer) The weight-average molecular weight of the nitrogen-containing nonionic polymer contained in the surface treatment composition according to the present invention is 0.1 to 10 relative to the weight-average molecular weight of the nitrogen-free nonionic polymer. That is, the ratio of the weight-average molecular weight of the nitrogen-containing nonionic polymer to the weight-average molecular weight of the nitrogen-free nonionic polymer ("weight-average molecular weight of nitrogen-containing nonionic polymer / weight-average molecular weight of nitrogen-free nonionic polymer") is 0.1 to 10. When the ratio of the weight-average molecular weight of the nitrogen-containing nonionic polymer to the weight-average molecular weight of the nitrogen-free nonionic polymer is within the above range, the nitrogen-free nonionic polymer and the nitrogen-containing nonionic polymer are easily adsorbed onto the polished object, thereby enabling efficient removal of residue. Hereinafter, the ratio of the weight-average molecular weight of the nitrogen-containing nonionic polymer to the weight-average molecular weight of the nitrogen-free nonionic polymer may be simply referred to as the "nitrogen-containing / nitrogen-free molecular weight ratio." If the nitrogen-containing / nitrogen-free molecular weight ratio is less than 0.1, the nitrogen-free nonionic polymer has a large molecular weight, which may result in the formation of organic residues. On the other hand, if the nitrogen-containing / nitrogen-free molecular weight ratio is more than 10, the nitrogen-containing nonionic polymer has a large molecular weight, which may result in the formation of organic residues.

[0039] The nitrogen-containing / nitrogen-free molecular weight ratio is preferably 0.1 or more and 8 or less, more preferably 0.2 or more and 6.5 or less, even more preferably 0.3 or more and 6 or less, particularly preferably 0.5 or more and 5.5 or less, particularly preferably 2 or more and less than 5.5, and most preferably 2.5 or more and 5.3 or less. When the nitrogen-containing / nitrogen-free molecular weight ratio is within the above range, the nitrogen-free nonionic polymer and the nitrogen-containing nonionic polymer are easily adsorbed to the polished object (e.g., a film containing silicon oxide, a film containing polysilicon), and residues on the surface of the polished object can be more efficiently removed after treatment with the surface treatment composition, thereby better demonstrating the desired effects of the present invention.

[0040] The weight-average molecular weight of the nitrogen-containing nonionic polymer is preferably 1,500 or more, more preferably 3,000 or more, even more preferably 5,000 or more, still more preferably 10,000 or more, particularly preferably 2,5000 or more, and most preferably 35,000 or more. The weight-average molecular weight of the nitrogen-free nonionic polymer is preferably 1,000,000 or less, more preferably 500,000 or less, even more preferably 300,000 or less, still more preferably 100,000 or less, particularly preferably 80,000 or less, and most preferably 60,000 or less. That is, the weight-average molecular weight of the nitrogen-free nonionic polymer is preferably 1,500 or more and 1,000,000 or less, more preferably 3,000 or more and 500,000 or less, even more preferably 5,000 or more and 300,000 or less, still more preferably 10,000 or more and 100,000 or less, particularly preferably 25,000 or more and 80,000 or less, and most preferably 35,000 or more and 60,000 or less.When the weight-average molecular weight of the nitrogen-free nonionic polymer is within the above range, residues on the surface of the polished object after treatment with the surface treatment composition can be more efficiently removed, and the expected effects of the present invention can be more effectively exhibited.

[0041] The nitrogen-containing nonionic polymer may be any nonionic polymer containing nitrogen atoms, such as polyamines, polyvinylpyrrolidone, polyacrylamide, poly-N-vinylacetamide, polydimethylacrylamide, polyacryloylmorpholine, poly-N-vinylcaprolactam, poly-N-isopropylacrylamide, and oxazoline group-containing polymers. In addition to those having the above-described main chain structures, graft copolymers having nonionic polymer structures in their side chains can also be suitably used. The nitrogen-containing nonionic polymer may be a polymer having the same (homopolymer) or different (copolymer) repeating units. When the nitrogen-containing nonionic polymer is a copolymer, the copolymer may be in the form of a block copolymer, random copolymer, graft copolymer, or alternating copolymer.

[0042] The nitrogen-containing nonionic polymer is preferably a polymer having an amide bond, more preferably one or more selected from the group consisting of polyvinylpyrrolidone, poly-N-vinylacetamide, polydimethylacrylamide, polyvinylcaprolactam, N-isopropylacrylamide, and oxazoline group-containing polymers. Two or more types of nitrogen-containing nonionic polymers may be used in combination.

[0043] The content of the nitrogen-free nonionic polymer in the surface treatment composition is preferably 0.001% by mass to 10% by mass, more preferably 0.005% by mass to 5% by mass, even more preferably 0.07% by mass to 3% by mass, particularly preferably 0.01% by mass to 1% by mass, and most preferably 0.01% by mass to 0.5% by mass, relative to the total mass of the surface treatment composition. When the surface treatment composition contains two or more nitrogen-containing nonionic polymers, the content of the nitrogen-free nonionic polymers is the total amount of these.

[0044] (anionic polymer) The anionic polymer contained in the surface treatment composition of the present invention acts as a dispersant in the surface treatment composition. By containing the anionic polymer in the surface treatment composition, the zeta potentials of the surface of the polished object (e.g., a polished object containing silicon nitride) and of defects such as abrasive grains and organic residues are both controlled to negative values, forming an electrostatic repulsion layer, which results in a reduction in the number of defects in the polished object.

[0045] The weight-average molecular weight of the anionic polymer is preferably 1,500 or more, more preferably 3,000 or more, even more preferably 4,000 or more, still more preferably 5,000 or more, particularly preferably 6,000 or more, especially more preferably 7,000 or more, and most preferably 8,000 or more. The weight-average molecular weight of the anionic polymer is preferably 1,000,000 or less, more preferably 500,000 or less, even more preferably 100,000 or less, still more preferably 50,000 or less, especially preferably 25,000 or less, especially more preferably 20,000 or less, and most preferably 15,000 or less. That is, the weight-average molecular weight of the anionic polymer is preferably 1,500 or more and 1,000,000 or less, more preferably 3,000 or more and 500,000 or less, even more preferably 4,000 or more and 100,000 or less, still more preferably 5,000 or more and 50,000 or less, particularly preferably 6,000 or more and 25,000 or less, particularly preferably 7,000 or more and 20,000 or less, and most preferably 8,000 or more and 15,000 or less.When the weight-average molecular weight of the anionic polymer is within the above range, residues on the surface of the polished object to be polished after treatment with the surface treatment composition can be more efficiently removed, and the expected effects of the present invention can be more effectively exhibited.

[0046] The anionic polymer may be any polymer having an anionic group, and specific examples include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polymethallyl sulfonic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), polyisoprene sulfonic acid, polyacrylic acid, polymethacrylic acid, (meth)acrylic acid-isoprene sulfonic acid copolymer, (meth)acrylic acid-[2-(meth)acrylamido-2-methylpropanesulfonic acid] copolymer, (meth)acrylic acid-isoprene sulfonic acid-[2-(meth)acrylamido-2-methylpropanesulfonic acid] copolymer, etc. These anionic polymers may be in the form of neutralized salts.

[0047] In addition, as the anionic polymer, not only those having the above-mentioned main chain structure but also graft copolymers having anionic polymer structures in their side chains can be suitably used. The anionic polymer may be a polymer having the same (homopolymer) or different (copolymer) repeating units, and when the anionic polymer is a copolymer, the copolymer may be in the form of a block copolymer, random copolymer, graft copolymer, or alternating copolymer.

[0048] Two or more kinds of anionic polymers may be used in combination. When two or more kinds of anionic polymers are contained in the surface treatment composition, the content of the anionic polymers is the total amount of these.

[0049] The content of the anionic polymer in the surface treatment composition is preferably 0.001 mass % or more and 10 mass % or less, more preferably 0.005 mass % or more and 1 mass % or less, even more preferably 0.07 mass % or more and 0.5 mass % or less, particularly preferably 0.008 mass % or more and 0.3 mass % or less, and most preferably 0.009 mass % or more and 0.1 mass % or less, relative to the total mass of the surface treatment composition.

[0050] (Other polymers) The surface treatment composition according to the present invention may further contain a polymer other than the above-mentioned nitrogen-free nonionic polymer, nitrogen-free nonionic polymer, and anionic polymer. The other polymer may be either a cationic polymer or an amphoteric polymer. Furthermore, the other polymer is preferably a water-soluble polymer. The water-soluble polymer referred to here refers to a water-soluble polymer (homopolymer) having the same repeating structural unit, or a water-soluble polymer (copolymer) having different repeating structural units, and is typically a compound with a weight-average molecular weight (Mw) of 1,000 or more.

[0051] Examples of cationic polymers include polyethyleneimine (PEI), polyvinylamine, polyallylamine, polyvinylpyridine, and cationic acrylamide polymers.

[0052] Examples of amphoteric polymers include copolymers of a vinyl monomer having an anionic group and a vinyl monomer having a cationic group, and vinyl-based amphoteric polymers having a carboxybetaine group or a sulfobetaine group. Specific examples include acrylic acid / dimethylaminoethyl methacrylic acid copolymers and acrylic acid / diethylaminoethyl methacrylic acid copolymers.

[0053] (solvent) The surface treatment composition according to the present invention 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 mixture 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, and propylene glycol. 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.

[0054] The water preferably contains as few impurities 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 impurity 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.

[0055] (chelating agent) The surface treatment composition according to one embodiment of the present invention preferably contains a chelating agent. By including a chelating agent in the surface treatment composition, abrasive grain residue can be further reduced. The chelating agent also has the function of adjusting the pH of the surface treatment composition. As the chelating agent, an organic compound having at least one phosphate group (-OP(=O)(OH)2) is preferred, and an organic compound having two or more phosphate groups (-OP(=O)(OH)2) is more preferred. That is, in one embodiment, the surface treatment composition of the present invention further contains a chelating agent having two or more phosphate groups. Specific examples of the chelating agent include orthophosphoric acid, methyl acid phosphate, ethyl acid phosphate, ethyl glycol acid phosphate, isopropyl acid phosphate, butyl acid phosphate, 2-ethylhexyl acid phosphate, pentetic acid, phytic acid, etidronic acid, edetic acid, 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), polyphosphoric acid, metaphosphoric acid, hexametaphosphoric acid, phosphonobutanetricarboxylic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, aminotrimethylenephosphonic acid, and salts thereof.

[0056] (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.

[0057] Examples of nonionic surfactants include compounds other than the above-mentioned nitrogen-free nonionic polymers and nitrogen-containing nonionic polymers. For example, alkyl ether types such as polyoxyethylene lauryl ether and polyoxyethylene oleyl ether; alkyl phenyl ether types such as polyoxyethylene octylphenyl ether; alkyl ester types such as polyoxyethylene laurate; alkyl amine types such as polyoxyethylene lauryl amino ether; alkyl amide types such as polyoxyethylene lauric acid amide; polypropylene glycol ether types such as polyoxyethylene polyoxypropylene ether; alkanolamide types such as oleic acid diethanolamide; and allyl phenyl ether types such as polyoxyalkylene allyl phenyl ether. Other examples of nonionic surfactants that can be used include propylene glycol, diethylene glycol, monoethanolamine, alcohol ethoxylates, alkylphenol ethoxylates, tertiary acetylene glycols, and alkanolamides. The above-mentioned nitrogen-free nonionic polymers and nitrogen-containing nonionic polymers can function as nonionic surfactants, so there is no need to add a separate nonionic surfactant.

[0058] Examples of anionic surfactants include compounds other than the above-mentioned anionic polymers, such as 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 phosphoric acid and sodium lauryl phosphate; and sulfonic acid types such as dioctyl sodium sulfosuccinate and sodium dodecylbenzenesulfonate. Note that the above-mentioned anionic polymers can function as anionic surfactants, so there is no need to add a separate anionic surfactant.

[0059] Examples of cationic surfactants include amines such as laurylamine hydrochloride; quaternary ammonium salts such as polyethoxyamine and lauryltrimethylammonium chloride; and pyridinium salts such as laurylpyridinium chloride.

[0060] Examples of amphoteric surfactants include lecithin, alkylamine oxide, alkylbetaines such as N-alkyl-N,N-dimethylammonium betaine, and sulfobetaines.

[0061] 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.

[0062] 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.

[0063] <pH of surface treatment composition> The pH of the surface treatment composition of the present invention is less than 7.0. When the pH of the surface treatment composition is less than 7.0, the zeta potential on the surface of the silicon nitride film becomes positive, and negatively charged anionic polymers are adsorbed onto the surface of the silicon nitride film by electrostatic attraction, reducing the number of defects from the perspective of surface protection. When the pH of the surface treatment composition is 7.0 or higher, the zeta potential on the surface of the silicon nitride film becomes negative, and the anionic polymers are electrostatically repelled by the silicon nitride film and do not adsorb, resulting in underprotection of the silicon nitride film and an increase in the number of defects in the silicon nitride film. The pH of the surface treatment composition is preferably 2 or higher but less than 7.0, more preferably 2 or higher but less than 6, even more preferably 2.3 or higher but less than 5.5, even more preferably 2.4 or higher but less than 5, particularly preferably 2.4 or higher but less than 4, and most preferably 2.4 or higher but less than 3.

[0064] (pH adjuster) The pH of the surface treatment composition can be adjusted with the above-mentioned chelating agent, but it may also contain a pH adjuster.

[0065] The pH adjuster is not particularly limited, and known pH adjusters used in the field of surface treatment compositions can be used, and known acids, bases, or salts thereof other than the above-mentioned chelating agents can be used. 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, azidopropyl ether, benzoic acid ... Examples of suitable organic acids include carboxylic acids such as pinic acid, fumaric acid, maleic acid, aconitic acid, amino acids, and anthranilic acid, as well as organic acids such as sulfonic acids and organic phosphonic acids; inorganic acids such as nitric acid, carbonic acid, hydrochloric acid, hypophosphorous acid, phosphorous acid, phosphonic acid, boric acid, and hydrofluoric acid; alkali metal hydroxides such as potassium hydroxide (KOH); alkali metal carbonates such as potassium carbonate (KCO) and sodium carbonate (NaCO); hydroxides of Group 2 elements; ammonia (ammonium hydroxide); and organic bases such as quaternary ammonium hydroxide compounds.

[0066] The pH adjuster may be a synthetic product or a commercially available product, and these pH adjusters may be used alone or in combination of two or more kinds.

[0067] The content of the pH adjuster in the surface treatment composition may be appropriately selected so as to give the desired pH value of the surface treatment composition.

[0068] The pH of the surface treatment composition is measured by the method described in the examples.

[0069] <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 avoid adding them as much as possible, and therefore, it is preferable to add them in as small an amount 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 is acidic. Furthermore, the surface treatment composition according to the present invention contains a polymer. 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 polymer. Specific examples include isothiazolin-based preservatives such as 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one, and phenoxyethanol.

[0070] Alternatively, the antifungal agent (antiseptic) may be a compound represented by the following Chemical Formula 1:

[0071] [ka]

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] Examples of the aralkyloxycarbonyl group having from 8 to 32 carbon atoms include a benzyloxycarbonyl group and a phenethyloxycarbonyl group.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] [ka]

[0087] 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.

[0088] 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.

[0089] 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).

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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).

[0094] The above antifungal agents (antiseptics) may be used alone or in combination of two or more kinds.

[0095] 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.

[0096] That is, in one embodiment of the present invention, the surface treatment composition is substantially composed of at least one selected from the group consisting of a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, an anionic polymer, a chelating agent, water, an antifungal agent, an organic solvent, a surfactant, and a pH adjuster. In one embodiment of the present invention, the surface treatment composition is substantially composed of at least one of a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, an anionic polymer, a chelating agent, water, and an antifungal agent and an organic solvent. In one embodiment of the present invention, the surface treatment composition is substantially composed of a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, an anionic polymer, a chelating agent, and water. In this 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 surface treatment composition is substantially composed of at least one of a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, an anionic polymer, a chelating agent, and water, and an anti-fungal agent and an organic solvent" means that the total content of the nitrogen-free nonionic polymer, the nitrogen-containing nonionic polymer, the anionic polymer, the chelating agent, and water, and an anti-fungal agent and an organic solvent 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. It is preferable that the surface treatment composition is composed of at least one of a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, an anionic polymer, a chelating agent, and water, and an anti-fungal agent and an organic solvent (the above total content = 100% by mass).

[0097] To further improve the foreign matter removal effect, it is preferable that the surface treatment composition of the present invention is substantially free of abrasive grains. Here, "substantially free of abrasive grains" means that the content of abrasive grains relative to the entire surface treatment composition is less than 0.1 mass % (preferably less than 0.01 mass %). That is, in one embodiment, the surface treatment composition of the present invention has a content of abrasive grains relative to the surface treatment composition is less than 0.1 mass %.

[0098] <Method of manufacturing the surface treatment composition> The surface treatment composition of the present invention can be produced, for example, by stirring and mixing a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, an anionic polymer, a solvent, and, if necessary, other components. The temperature at which the components are mixed is not particularly limited, but is preferably 10°C or higher and 40°C or lower, and heating may be performed to increase the dissolution rate. The mixing time is also not particularly limited.

[0099] <Surface treatment method> Another aspect of the present invention is a surface treatment method, which comprises treating the surface of a polished object with the above-mentioned surface treatment composition. In this specification, the 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.

[0100] According to one aspect of the present invention, the surface treatment method can sufficiently remove residues remaining on the surface of a polished object. That is, according to another aspect of the present invention, there is provided a method for reducing residues on the surface of a polished object, in which the polished object is surface-treated with the above-mentioned surface treatment composition. Furthermore, according to another aspect of the present invention, there is also provided a surface treatment method for treating a polished object containing at least one selected from the group consisting of silicon oxide, polysilicon, and silicon nitride with the above-mentioned surface treatment composition, thereby reducing residues on the surface of the polished object.

[0101] A surface treatment method according to one embodiment of the present invention is carried out by directly contacting the surface treatment composition according to the present invention with the polished object.

[0102] Surface treatment methods mainly include (I) a method using a rinse polishing process and (II) a method using a cleaning process. That is, according to one embodiment of the present invention, the surface treatment is preferably performed by a rinse polishing process or a cleaning process. That is, the surface treatment method is preferably a rinse polishing process or a cleaning process. The rinse polishing process and the cleaning process are performed to remove foreign matter (particles, metal contamination, organic residues, pad debris, etc.) on the surface of the polished object to obtain a clean surface. The above (I) and (II) will be explained below.

[0103] (I) Rinse polishing treatment The surface treatment composition according to the present invention is preferably used in a rinse polishing process. That is, the surface treatment composition according to one embodiment 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 the final polishing (finish polishing) of the object to be polished, with the aim of removing foreign matter from the surface of the object to be polished. The rinse polishing process is performed by directly contacting the surface treatment composition according to the present invention with the polished object to be polished. As a result, 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 foreign matter, particles and organic residues are particularly easily removed by physical action. Therefore, in the rinse polishing process, friction with the polishing pad on the polishing table (platen) can be used to effectively remove particles and organic residues.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] After the rinse polishing treatment using the surface treatment composition according to one embodiment of the present invention, the polished object to be polished (object to be surface-treated) is preferably pulled up and removed while being subjected to the surface treatment composition according to one embodiment of the present invention.

[0111] (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 one embodiment 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 the polished object to be polished (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. The cleaning treatment and the rinse polishing treatment described above are classified according to the location where these treatments are performed. The cleaning treatment is a surface treatment performed at a location other than the polishing table (platen), and is preferably a surface treatment performed after the polished object to be polished is removed from the polishing table (platen). In the cleaning treatment, the surface treatment composition of the present invention can be directly brought into contact with the polished object to be polished to remove foreign matter from the surface of the object.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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 pressure (polishing pressure) applied to the surface treatment object (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 cleaning brush 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 surfaces of the cleaning brush and the object to be cleaned are always covered with the surface treatment composition, and a rate of 10 mL / min or more and 5000 mL / min or less is preferred. The cleaning time is also not particularly limited, but for the process using the surface treatment composition according to one embodiment of the present invention, it is preferably 5 seconds or more and 180 seconds or less. Within such a range, foreign matter can be more effectively removed.

[0120] 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.

[0121] In the above method (ii), the conditions for the immersion cleaning method are not particularly limited, and known methods can be used.

[0122] Before carrying out the surface treatment by the above method (I) or (II), washing with water may be carried out.

[0123] (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 according to one embodiment 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 the 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 the cleaning brush into contact with one or both sides of the object, and then supply water or an aqueous solution (e.g., an NH3 aqueous solution) or water and an aqueous solution (e.g., an NH3 aqueous solution) to the contact area in any order (water is supplied, then the aqueous solution, or the aqueous solution is supplied, then water is supplied), while scrubbing the surface of the object with the cleaning brush. Regarding the apparatus and conditions for the post-cleaning treatment, the explanation of the surface treatment in (II) above can be referred to. Here, it is particularly preferred to use deionized water as the water used in the post-cleaning treatment.

[0124] 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.

[0125] Furthermore, after the surface treatment or post-cleaning, the polished object (surface-treated object) is preferably dried by removing water droplets adhering to the surface using a spin dryer or the like. Alternatively, the surface of the surface-treated object may be dried by air blow drying.

[0126] <Method of manufacturing semiconductor substrate> The surface treatment method according to one embodiment of the present invention is suitably applied when the polished object to be polished is a polished semiconductor substrate. That is, according to another embodiment of the present invention, there is also provided a method for producing a semiconductor substrate, wherein the polished object to be polished is a polished semiconductor substrate, and the method comprises reducing residues on the surface of the polished semiconductor substrate by the above-mentioned surface treatment method. Thus, according to the present invention, there is provided a method for producing a semiconductor substrate, wherein the polished object to be polished is a polished semiconductor substrate, the method comprising: a polishing step of obtaining a polished semiconductor substrate by polishing a pre-polishing semiconductor substrate containing at least one selected from the group consisting of silicon oxide, polysilicon, and silicon nitride with a polishing composition containing abrasive grains, and a surface treatment step of reducing residues containing abrasive grains on the surface of the polished semiconductor substrate with the above-mentioned surface treatment composition.

[0127] 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.

[0128] 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 a surface treatment composition according to one embodiment 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 that includes 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.

[0129] [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.

[0130] 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.

[0131] 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 for example, a composition containing abrasive grains, a solvent, a pH adjuster, and an electrical conductivity adjuster can be preferably used. Specific examples of such polishing compositions include a polishing composition containing silicon oxide (e.g., anion-modified colloidal silica), maleic acid, ammonium sulfate, and water. Furthermore, the pH of the polishing composition is preferably 2 or more and 6 or less.

[0132] 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 silicon oxide, alumina, ceria, and titania, silicon nitride particles, silicon carbide particles, and boron nitride particles. Specific examples of organic particles include polymethyl methacrylate (PMMA) particles. The abrasive grains may be commercially available or synthetic products. Furthermore, the abrasive grains may be surface-modified. The abrasive grains may be used alone or in combination of two or more types.

[0133] 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 even more 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 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.

[0134] 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.

[0135] 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.

[0136] The pH adjuster and solvent are the same as those defined above in the sections (pH adjuster) and (solvent), and therefore a description thereof will be omitted here.

[0137] The electrical conductivity adjuster adjusts the electrical conductivity of the polishing composition to an appropriate range, thereby synergistically enhancing the polishing-accelerating effect and improving the dispersion stability of the polishing composition. The electrical conductivity adjuster is not particularly limited as long as it is a compound having an electrical conductivity adjusting function, and examples thereof include salt compounds such as nitrates such as potassium nitrate and ammonium nitrate, phosphates such as diammonium hydrogen phosphate and ammonium dihydrogen phosphate, and sulfates such as ammonium sulfate. The amount (concentration) of the electrical conductivity adjuster to be added may be appropriately selected so as to achieve the desired electrical conductivity of the polishing composition.

[0138] The polishing device may be a general polishing device equipped with a holder for holding the object to be polished, a motor capable of changing the rotation speed, etc., and a polishing platen to which a polishing pad (polishing cloth) can be attached. Either a single-sided polishing device or a double-sided polishing device may be used.

[0139] 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 to allow the polishing liquid to accumulate.

[0140] 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.

[0141] [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.

[0142] (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.

[0143] Details of the rinse polishing method used in the rinse polishing step are as described above in the explanation of the rinse polishing treatment.

[0144] (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.

[0145] Details of the cleaning method used in the cleaning step are as described above in the description of the cleaning method. [Example]

[0146] 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 relative humidity of 40% RH or more and 50% RH or less.

[0147] [Polymer preparation] The following nitrogen-free nonionic polymer, nitrogen-containing nonionic polymer, and anionic polymer were prepared.

[0148] "Nitrogen-free nonionic polymer" Polyvinyl alcohol (x1) JMR-3HH (Japan Vinyl Acetate & Poval Co., Ltd.); weight average molecular weight 5,000 (x2) JMR-10HH (Japan Vinyl Acetate & Poval Co., Ltd.); weight average molecular weight 10,000 (x3) Denka Poval K-05 (Denka Co., Ltd.); weight average molecular weight 22,000.

[0149] "Nitrogen-containing nonionic polymer" Polyvinylpyrrolidone (a1) Pitzcol K17L (Dai-ichi Kogyo Seiyaku Co., Ltd.); weight-average molecular weight: 9,000 (a2) Pitzcol K30A (Dai-ichi Kogyo Seiyaku Co., Ltd.); weight-average molecular weight: 45,000 (a3) Pitzcol K50 (Dai-ichi Kogyo Seiyaku Co., Ltd.); weight-average molecular weight: 250,000 Polydimethylacrylamide (b) Poly(N,N-dimethylacrylamide) (Sigma-Aldrich Japan); weight-average molecular weight: 10,000 Poly-N-vinylacetamide (c1) PNVA GE191-107 (Showa Denko K.K.); weight average molecular weight 50,000 (c2) PNVA GE191-104 (Showa Denko K.K.); weight average molecular weight: 300,000 (c3) PNVA GE191-103 (Showa Denko K.K.); weight average molecular weight 9,000,000 Poly N-isopropylacrylamide (d) Poly(N-isopropylacrylamide) (Sigma-Aldrich Japan); weight-average molecular weight: 40,000 Oxazoline group-containing polymer (e) Epocross WS-700 (Nippon Shokubai Co., Ltd.); weight average molecular weight: 40,000 Poly N-vinylcaprolactam (f) Luviscol Plus (BASF); weight average molecular weight 70,000.

[0150] "Anionic polymers" Sodium salt of copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid (hereinafter referred to as "(acrylic acid / sulfonic acid) copolymer") (product name: Aron A-6012 (Toagosei Co., Ltd.)); weight-average molecular weight: 12,000 The weight average molecular weight of the above polymer was measured by the following method.

[0151] [Measurement of weight-average molecular weight (Mw) of polymers] The weight-average molecular weight (Mw) of the polymer 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.

[0152] [Measurement of pH of surface treatment composition] The pH of the surface treatment composition (liquid temperature: 25° C.) was confirmed using a pH meter (manufactured by Horiba, Ltd., product name: LAQUA (registered trademark)).

[0153] [Preparation of surface treatment composition] Example 1 Surface treatment composition A1 was prepared by mixing and stirring polyvinyl alcohol having a weight-average molecular weight of 22,000 as a nitrogen-free nonionic polymer; poly-N-vinylacetamide having a weight-average molecular weight of 9,000 as a nitrogen-containing nonionic polymer; an acrylic acid / sulfonic acid copolymer having a weight-average molecular weight of 12,000 as an anionic polymer; water (deionized water) as a solvent; and 1-hydroxyethane-1,1-diphosphonic acid (hereinafter referred to as "HEDP") (product name: Dequest 2010EL (Italmatch Japan Co., Ltd.)) as a chelating agent at 25°C for 5 minutes.

[0154] Here, the content of the non-nitrogen-containing nonionic polymer was 0.1 mass% relative to the total mass of the surface treatment composition A1; the content of the nitrogen-containing nonionic polymer was 0.1 mass% relative to the total mass of the surface treatment composition A1; the content of the anionic water-soluble polymer was 0.01 mass% relative to the total mass of the surface treatment composition A1; and the content of the chelating agent was an amount such that the pH of the surface treatment composition A1 was 2.5 (0.02 mass% relative to the total mass of the surface treatment composition A1).

[0155] (Examples 2 to 24, Comparative Examples 1 to 35) Surface treatment compositions A2 to A24 and surface treatment compositions B1 to B35 were prepared in the same manner as in Example 1, except that the type and / or content of the nitrogen-free nonionic polymer, nitrogen-containing nonionic polymer, and anionic polymer were changed as shown in Tables 1A to 1D below. Surface treatment compositions A10 and A12 of Examples 10 and 12 and surface treatment compositions B28 to B31 of Comparative Examples 28 to 31 contained the chelating agent in the amount shown in Tables 1A and 1C, and the pH was adjusted to the values ​​shown in Tables 1A and 1C using ammonia. In Comparative Examples 10 to 13, polyethylene glycol (PEG) or polypropylene glycol (PPG) was used as the nonionic polymer instead of the anionic polymer.

[0156] In Tables 1A to 1D and Tables 2A to 2D described below, nitrogen-containing (nitrogen-free) nonionic polymers are referred to as "N-containing (N-free) nonionic polymers," (acrylic acid / sulfonic acid) copolymers are referred to as "AA / SA copolymers," and polyvinyl alcohol is referred to as "PVA." Also, in Tables 1A to 1D and Tables 2A to 2D described below, "N-containing / N-free molecular weight ratio" refers to the "weight-average molecular weight ratio of the N-containing nonionic polymer / weight-average molecular weight of the N-free nonionic polymer."

[0157] [Table 1A]

[0158] [Table 1B]

[0159] [Table 1C]

[0160] [Table 1D]

[0161] [Preparation of polished object] A polished object was prepared after being polished by the following chemical mechanical polishing (CMP) process.

[0162] (CMP process) The objects to be polished were (1) a silicon wafer (TEOS substrate) (300 mm, blanket wafer, manufactured by Advantec Co., Ltd.) with a 10,000 Å-thick TEOS film formed on its surface, (2) a polycrystalline silicon wafer (300 mm, manufactured by Advanced Materials Technology Co., Ltd.), and (3) a silicon wafer (SiN substrate) (300 mm, blanket wafer, manufactured by Advantec Co., Ltd.) with a 2,500 Å-thick SiN film formed on its surface.

[0163] The TEOS substrate and polycrystalline silicon wafer prepared above were polished using a polishing composition (composition: 2 mass% sulfonic acid-modified colloidal silica (average primary particle size 35 nm, average secondary particle size 70 nm), 0.0006 mass% maleic acid, 0.25 mass% ammonium sulfate, solvent: water, pH: 3.0) under the following conditions.

[0164] The sulfonic acid-modified colloidal silica was prepared using colloidal silica with an average primary particle size of 35 nm, an average secondary particle size of 70 nm, and an average degree of association of 2, according to the method described in “Sulfonic acid-functionalized silica through quantitative oxidation of thiol groups”, Chem. Commun. 246-247 (2003).

[0165] <Polishing equipment and polishing conditions> Polishing equipment: Ebara Corporation FREX300E Polishing pad: Fujibo Holdings Co., Ltd., polyurethane foam pad 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.

[0166] (rinse polishing) After the surface of the object to be polished was polished in the CMP process, the polished object was removed from the polishing table (platen). Subsequently, in the same polishing apparatus, the polished object was mounted on another polishing table (platen), and the surface of the polished object was subjected to a rinse polishing treatment using the surface treatment compositions A1 to A24 and B1 to B35 prepared in Examples 1 to 24 and Comparative Examples 1 to 35 under the following conditions.

[0167] <Rinse polishing equipment and rinse polishing conditions> Grinding pressure: 1.0 psi Plate rotation speed: 60 rpm Head rotation speed: 80 rpm Supply of surface treatment composition: free-flowing Surface treatment composition supply rate: 300 mL / min Polishing time: 60 seconds.

[0168] After the rinse-polishing process, the surfaces of the TEOS and SiN substrates were brush-cleaned with a 0.3% NH3 aqueous solution for 20 seconds, followed by rinsing with deionized water for 40 seconds to obtain polished, rinse-polished objects.The surfaces of the Poly-Si substrates were brush-cleaned with deionized water for 60 seconds to obtain polished, rinse-polished objects.

[0169] [evaluation] (residue count measurement) Using a Surfscan® SP5 optical inspection system manufactured by KLA-Tencor Corporation, the number of residues on the surfaces of polished TEOS, Poly-Si, and SiN substrates after rinse polishing was evaluated. Specifically, the number of residues exceeding 50 nm in diameter for TEOS substrates and SiN groups, and those exceeding 70 nm in diameter for Poly-Si substrates, was counted on the remaining areas of each surface, excluding a 5 mm-wide area from the outer edge of the polished TEOS, Poly-Si, and SiN substrates (the area from 0 mm to 5 mm wide, with the outer edge being defined as 0 mm). The number of abrasive grain residues and organic residues on the polished TEOS, Poly-Si, and SiN substrates was then measured by SEM observation using a Review SEM RS6000 manufactured by Hitachi High-Tech Corporation. First, 100 residue samples were taken from the remaining areas of each surface, excluding a 5 mm-wide area from the outer edge of the polished TEOS, Poly-Si, and SiN substrates. 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 dust, polymers, etc.) was confirmed.

[0170] The evaluation results are shown in Tables 2A to 2D below. In Tables 2A to 2D, "PVP" represents polyvinylpyrrolidone, "PNVA" represents poly-N-vinylacetamide, "PDMA" represents polydimethylacrylamide, "PNVCL" represents poly-N-vinylcaprolactam, and "PNIPAM" represents poly-N-isopropylacrylamide.

[0171] [Table 2A]

[0172] [Table 2B]

[0173] [Table 2C]

[0174] [Table 2D]

[0175] As is clear from Tables 2A to 2D above, it was found that the surface treatment compositions A1 to A24 of Examples 1 to 24 were able to reduce residues on the surface of a polished object containing a silicon-containing material compared to the surface treatment compositions B1 to B35 of Comparative Examples 1 to 35.

[0176] The above results are those evaluated immediately after the production of the surface treatment composition, but when the surface treatment composition is to be stored for a long period of time, it is preferable to include a mildew inhibitor (preservative). Note that the mildew inhibitor (preservative) has little or no effect on the above results, so it is considered that a surface treatment composition containing a mildew inhibitor (preservative) will also produce the same results as those described above.

Claims

1. The composition includes a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, and an anionic polymer, The weight average molecular weight of the nitrogen-free nonionic polymer is less than 100,000, a ratio of a weight average molecular weight of the nitrogen-containing nonionic polymer to a weight average molecular weight of the nitrogen-free nonionic polymer (nitrogen-containing nonionic polymer / nitrogen-free nonionic polymer) is 0.1 or more and 10 or less; A rinse polishing composition or cleaning composition having a pH of less than 7.

0.

2. The polishing rinse composition or cleaning composition according to claim 1 , wherein the nitrogen-containing nonionic polymer has an amide bond.

3. 3. The polishing composition for rinsing or the cleaning composition according to claim 1, wherein the weight average molecular weight of the nitrogen-containing nonionic polymer is 80,000 or less.

4. The rinse-polishing composition or cleaning composition according to any one of claims 1 to 3, wherein the nitrogen-containing nonionic polymer is at least one selected from the group consisting of polyvinylpyrrolidone, poly-N-vinylacetamide, polydimethylacrylamide, polyvinylcaprolactam, N-isopropylacrylamide, and oxazoline group-containing polymers.

5. The ratio of the molecular weight of the nitrogen-containing nonionic polymer to the molecular weight of the nitrogen-free nonionic polymer (nitrogen-containing nonionic polymer / nitrogen-free nonionic polymer) is 0.1 or more and 8 or less according to any one of claims 1 to 4.

6. The polishing rinse composition or cleaning composition according to any one of claims 1 to 5, wherein the non-nitrogen-containing nonionic polymer is polyvinyl alcohol.

7. The polishing rinse composition or cleaning composition according to any one of claims 1 to 6, further comprising a chelating agent having two or more phosphate groups.

8. The rinse polishing composition or cleaning composition of claim 7, which is substantially free of abrasive grains.

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

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

11. the polished object is a polished semiconductor substrate, a polishing step of polishing an unpolished semiconductor substrate containing at least one material selected from the group consisting of silicon oxide, polysilicon, and silicon nitride 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 rinse polishing composition or cleaning composition according to any one of claims 1 to 8; A method for manufacturing a semiconductor substrate, comprising:

12. The method for producing a semiconductor substrate according to claim 11, wherein the polishing composition has a pH of 2 or more and 6 or less.

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