Post chemical mechanical polishing cleaning composition, post chemical mechanical polishing cleaning processing method and method for manufacturing semiconductor substrate

Abstract

To provide means by which residual residue on the surface of polished abrasive objects containing silicon-containing materials can be sufficiently removed.SOLUTION: A post chemical mechanical polishing cleaning composition contains a nitrogen-containing nonionic polymer and an anionic polymer containing sulfonic acid groups, and the nitrogen-containing nonionic polymer content is greater than 0.1% by mass and less than 1.0% by mass of the total post-chemical mechanical polishing cleaning composition, and the pH is less than 7.0.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a post-chemical mechanical abrasive cleaning composition, a post-chemical mechanical abrasive cleaning treatment method, and a method for manufacturing a semiconductor substrate. [Background technology]

[0002] In recent years, with the trend toward multilayer wiring on the surface of semiconductor substrates, a so-called chemical mechanical polishing (CMP) technique is used to physically polish and flatten the semiconductor substrate when manufacturing devices. CMP is a method for flattening the surface of an object to be polished (workpiece to be polished) such as a semiconductor substrate using a polishing composition (slurry) containing abrasive grains such as silica, alumina, ceria, etc., an anticorrosive agent, a surfactant, etc., and the object to be polished (workpiece to be polished) is a silicon-containing material such as silicon, polysilicon, silicon oxide, and silicon nitride, or wiring, plugs, etc. made of metal, etc.

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

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

[0005] As such a cleaning composition, for example, Patent Document 1 discloses a rinsing composition for silicon wafers that contains a water-soluble polymer that satisfies specific conditions, and discloses that this composition can remove foreign matter from polished silicon wafers and reduce defects in the polished silicon wafers. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2020-167237 A Summary of the Invention [Problem to be solved by the invention]

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

[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 a silicon-containing material. [Means for solving the problem]

[0009] In view of the above problems, the present inventors have conducted extensive research and found that the above problems can be solved by a post-chemical mechanical polishing cleaning composition that contains a nitrogen-containing nonionic polymer and an anionic polymer containing a sulfonic acid group, the content of the nitrogen-containing nonionic polymer being more than 0.1 mass % and less than 1.0 mass % based on the total amount of the post-chemical mechanical polishing cleaning composition, and has a pH of less than 7.0, thereby completing the present invention. Effect of the Invention

[0010] According to the present invention, a means is provided that can sufficiently remove residues remaining on the surface of a polished object that contains a silicon-containing material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention relates to a post-chemical mechanical polishing cleaning composition comprising a nitrogen-containing nonionic polymer and an anionic polymer containing a sulfonic acid group, the content of the nitrogen-containing nonionic polymer being more than 0.1 mass % and less than 1.0 mass % relative to the total post-chemical mechanical polishing cleaning composition, and the pH being less than 7.0.

[0012] In this specification, the post-chemical mechanical polishing cleaning composition having the above-mentioned configuration is also referred to as "the post-chemical mechanical polishing cleaning composition of the present invention," "the post-CMP cleaning composition" or "the post-CMP cleaning composition of the present invention."

[0013] The post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) of the present invention can sufficiently remove residues (e.g., abrasive grain residues, particularly silicon compounds, organic residues) remaining on the surface of a polished object, particularly a polished object containing a silicon-containing material such as silicon nitride, silicon oxide, and polysilicon.

[0014] In this specification, the polished object means an object to be polished after being polished with a polishing composition. In the present invention, the polished object to be polished includes a silicon-containing material. The polished object to be polished including silicon nitride means that the polished object to be polished has a film (layer) including silicon nitride, the polished object to be polished including silicon oxide means that the polished object to be polished has a film (layer) including silicon oxide, and the polished object to be polished including polysilicon means that the polished object to be polished has a film (layer) including polysilicon. That is, the polished object to be polished according to the present invention has at least one silicon-containing material, for example, selected from the group consisting of silicon nitride, silicon oxide, and polysilicon. Hereinafter, the "polished object to be polished including a silicon-containing material" may be simply referred to as the "polished object to be polished".

[0015] The present inventors speculate that the mechanism by which the above-mentioned configuration can remove residues from the surface of a polished object is as follows.

[0016] That is, the components contained in the post-CMP cleaning composition act on the surface of the polished object, thereby removing the residue from the surface of the polished object. Specifically, the nitrogen-containing nonionic polymer and the anionic polymer containing sulfonic acid groups are adsorbed on the surface of the polished object, thereby allowing the residue present on the surface of the polished object to be detached. The present inventors have found that, in removing these residues, the content of the nitrogen-containing nonionic polymer is more than 0.1 mass % and less than 1.0 mass % with respect to the entire post-CMP cleaning composition, and the pH is less than 7.0, so that the residue on the surface of the polished object can be removed more efficiently. Although the details of these mechanisms are unclear, the following reasons are presumed. That is, by adopting the above-mentioned configuration, the nitrogen-containing nonionic polymer and the anionic polymer containing sulfonic acid groups are more effectively adsorbed on the polished object, which is considered to allow the residue on the surface of the polished object to be more efficiently detached, while preventing the residue (contaminant) from reattaching to the surface of the polished object.

[0017] Anionic polymers containing sulfonic acid groups are easily adsorbed to films containing silicon nitride, and the post-CMP cleaning composition of the present invention can preferably exert the above-mentioned effects on films containing silicon nitride. In addition, since the sulfonic acid group is a strongly acidic group, it can generate hydrogen ions (H + ) and ionized (R-SO3 - Therefore, when the post-CMP cleaning composition contains an anionic polymer containing a sulfonic acid group, the sulfonic acid group in the anionic polymer containing a sulfonic acid group can be maintained in an ionized state (R-SO3 -), the zeta potentials of both the polished object to be polished and the residue (contaminant) on the surface to which the anionic polymer containing sulfonic acid groups is adsorbed can be controlled to be negative. This generates an electrostatic repulsion between the polished object to be polished and the residue (contaminant), which allows the residue (contaminant) to be efficiently detached from the polished object to be polished and prevents it from reattaching to the polished object to be polished. Nitrogen-containing nonionic polymers are easily adsorbed to films containing silicon oxide and / or films containing polysilicon, and the post-CMP cleaning composition of the present invention can suitably exhibit the above-mentioned effects on films containing silicon oxide and / or films containing polysilicon. In addition, the nitrogen atoms of the nitrogen-containing nonionic polymer can be particularly effectively adsorbed to films containing silicon oxide by forming hydrogen bonds with hydroxyl groups present on the surface of the film containing silicon oxide, thereby further enhancing the above-mentioned effects.

[0018] Furthermore, by adopting the above-mentioned composition, each component (nitrogen-containing nonionic polymer and anionic polymer containing sulfonic acid group) 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 each component adsorbed on the surface of the object to be polished can be hardly or not left as a residue. From the above, it is considered that the post-CMP cleaning composition of the present invention can sufficiently remove the residue.

[0019] It should be noted that the above mechanism is based on speculation, and the present invention is not limited to the above mechanism in any way.

[0020] The embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be modified in various ways within the scope of the claims. The embodiments described in this specification can be combined in any way to form other embodiments. In this specification, unless otherwise specified, operations and measurements of physical properties are performed under conditions of room temperature (20°C to 25°C) and relative humidity of 40% RH to 50% RH.

[0021] <Residue> In this specification, residue refers to foreign matter that adheres to the surface of the polished object.The example of residue is not particularly limited, but can be, for example, organic residue described later, particle residue derived from abrasive grain contained in polishing composition, residue made of components other than particle residue and organic residue, mixture of particle residue and organic residue, and other residues.

[0022] 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.

[0023] Examples of organic residues adhering to the polished object include pad waste 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 post-CMP cleaning composition used in the rinse polishing step.

[0024] Since organic residues and other foreign matter are significantly different in color and shape, whether or not a foreign matter is an organic residue can be determined by visual inspection using an SEM. In addition, whether or not a foreign matter is an organic residue can be determined by elemental analysis using an energy dispersive X-ray analyzer (EDX) as necessary. The number of organic residues can be measured using a wafer defect inspection device and SEM or EDX elemental analysis.

[0025] <Polished object> In this specification, the term "polished object" refers to an object that has been polished in a polishing process, which is a CMP process.

[0026] The polished object (polished object) according to the present invention includes a silicon-containing material, such as silicon nitride (Si3N4), silicon oxide (SiO2) and polysilicon (polycrystalline silicon). In one embodiment, the polished object (polished object) according to the present invention includes at least one selected from the group consisting of silicon nitride (Si3N4), silicon oxide (SiO2) and polysilicon (polycrystalline silicon).

[0027] The material contained in the object to be polished according to the present invention is not particularly limited as long as it contains at least one type of silicon-containing material selected from the group consisting of silicon nitride (Si3N4), silicon oxide (SiO2), 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 metals, alloys, metal nitrides, compound semiconductors such as SiGe, and the like.

[0028] Examples of the film containing silicon oxide include a TEOS (Tetraethyl Orthosilicate) type silicon oxide film (hereinafter also simply referred to as a "TEOS film") produced using tetraethyl orthosilicate as a precursor, a HDP (High Density Plasma) film, a USG (Undoped Silicate Glass) film, a PSG (Phosphorus Silicate Glass) film, a BPSG (Boron-Phospho Silicate Glass) film, an RTO (Rapid Thermal Oxidation) film, etc. The film containing silicon oxide contained in the polished object may be one type alone or two or more types in combination.

[0029] The polished object is a polished semiconductor substrate, 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.

[0030] In addition, the post-CMP cleaning composition according to one embodiment of the present invention can reduce residues on the surface of a polished object that contains both a hydrophilic material and a hydrophobic material. Here, the hydrophilic material refers to a material that has a contact angle with water of less than 50°, and the hydrophobic material refers to a material that has 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.

[0031] Specific examples of hydrophilic materials include silicon oxide, silicon nitride, silicon oxynitride, tungsten, titanium nitride, tantalum nitride, boron-containing silicon, and the like. 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 polysilicon (polycrystalline silicon), single crystal silicon, amorphous silicon, carbon-containing silicon, and the like. 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 polysilicon (polycrystalline silicon).

[0032] That is, according to a preferred embodiment of the present invention, the hydrophilic material is silicon nitride and the hydrophobic material is polysilicon (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 polysilicon (polycrystalline silicon).

[0033] <Post-Chemical Mechanical Polishing Cleaning Composition (Post-CMP Cleaning Composition)> The post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) according to the present invention contains a nitrogen-containing nonionic polymer and an anionic polymer containing a sulfonic acid group. In this specification, the term "polymer" refers to a compound having a weight average molecular weight (Mw) of 1000 or more. In addition, in this specification, the term "nonionic polymer" refers to a polymer that does not have an anionic group such as a carboxylic acid group, a sulfonic acid group, or a phosphoric acid group, and a cationic group such as an amino group or a quaternary ammonium group, in the molecule. The term "anionic polymer" refers to a polymer that has an anionic group such as a carboxylic acid group, a sulfonic acid group, or a phosphoric acid group in the molecule. Each polymer will be described below.

[0034] (Nitrogen-containing nonionic polymer) The nitrogen-containing nonionic polymer contained in the post-CMP cleaning composition according to the present invention refers to a nonionic polymer that contains a nitrogen atom in the molecule.

[0035] 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, even more preferably 10,000 or more, particularly preferably 25,000 or more, and most preferably 35,000 or more. The weight average molecular weight of the nitrogen-containing nonionic polymer is preferably 1,000,000 or less, more preferably 500,000 or less, even more preferably 300,000 or less, even 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-containing 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, even 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-containing nonionic polymer is within the above range, the residue on the surface of the polished object to be polished after treatment with the post-CMP cleaning composition can be more efficiently removed, and the expected effect of the present invention can be more effectively exhibited.

[0036] The nitrogen-containing nonionic polymer may be any nonionic polymer having a nitrogen atom, such as polyamines, polyvinylpyrrolidone, polyacrylamide, poly-N-vinylacetamide, polydimethylacrylamide, polyacryloylmorpholine, poly-N-vinylcaprolactam, poly-N-isopropylacrylamide, and oxazoline group-containing polymers. As the nitrogen-containing nonionic polymer, not only those having the main chain structure as described above, but also graft copolymers having a nonionic polymer structure in the side chain can be suitably used. The nitrogen-containing nonionic polymer may be a polymer having the same (single polymer; homopolymer) or different (copolymer; copolymer) repeating structural units, and when the nitrogen-containing nonionic polymer is a copolymer, the form of the copolymer may be any of block copolymer, random copolymer, graft copolymer, and alternating copolymer.

[0037] The nitrogen-containing nonionic polymer is preferably a polymer having an amide bond, more preferably a polymer having an amide bond in the side chain structure, and even more preferably at least one selected from the group consisting of polyvinylpyrrolidone, poly-N-vinylacetamide, polydimethylacrylamide, polyvinylcaprolactam, N-isopropylacrylamide, and oxazoline group-containing polymers. The nitrogen-containing nonionic polymer may be used alone or in combination of two or more. The nitrogen-containing nonionic polymer may be a commercially available product or a synthetic product.

[0038] The content of the nitrogen-containing nonionic polymer in the post-CMP cleaning composition is more than 0.1% by mass and less than 1.0% by mass, preferably 0.15% by mass or more and 0.8% by mass or less, more preferably 0.15% by mass or more and 0.45% by mass or less, and even more preferably 0.15% by mass or more and 0.4% by mass or less, based on the total mass of the post-CMP cleaning composition. If the content of the nitrogen-containing nonionic polymer is 0.1% by mass or less, based on the total mass of the post-CMP cleaning composition, the residue on the surface of the polished object may not be sufficiently removed, and if it is 1.0% by mass or more, the nitrogen-containing nonionic polymer itself may remain on the polished object as a residue. In addition, from the viewpoint of further reducing the value of the zeta potential on the surface of the polished object, it is particularly preferable that the content is 0.15% by mass or more and 0.20% by mass or less. If two or more kinds of nitrogen-containing nonionic polymers are contained in the post-CMP cleaning composition, the content of the nitrogen-containing nonionic polymer is the total amount of these.

[0039] (Anionic polymer containing sulfonic acid groups) The anionic polymer containing sulfonic acid groups contained in the post-CMP cleaning composition according to the present invention acts as a dispersant in the post-CMP cleaning composition. By containing an anionic polymer containing sulfonic acid groups in the post-CMP cleaning composition, the zeta potentials of the surface of the polished object (e.g., the polished object containing silicon nitride) and defect sources such as abrasive grains and organic residues are both controlled to be negative, and an electrostatic repulsion layer is formed, which results in a reduction in the number of defects in the polished object.

[0040] The weight average molecular weight of the anionic polymer containing sulfonic acid groups is preferably 1,500 or more, more preferably 3,000 or more, even more preferably 4,000 or more, even more preferably 5,000 or more, particularly preferably 6,000 or more, particularly more preferably 7,000 or more, and most preferably 8,000 or more. The weight average molecular weight of the anionic polymer containing sulfonic acid groups is preferably 1,000,000 or less, more preferably 500,000 or less, even more preferably 100,000 or less, even more preferably 50,000 or less, particularly preferably 25,000 or less, particularly more preferably 20,000 or less, and most preferably 15,000 or less. That is, the weight average molecular weight of the anionic polymer containing sulfonic acid groups 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, even 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 containing sulfonic acid groups is within the above range, the residue on the surface of the polished object to be polished after the treatment using the post-CMP cleaning composition can be more efficiently removed, and the expected effect of the present invention can be more effectively exhibited.

[0041] The anionic polymer containing a sulfonic acid group may be any polymer having a sulfonic acid group, and specific examples thereof include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polymethallyl sulfonic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), polyisoprene sulfonic 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 containing a sulfonic acid group may be in the form of a neutralized salt.

[0042] In addition, as the anionic polymer containing sulfonic acid groups, not only those having the above-mentioned main chain structure, but also graft copolymers having an anionic polymer structure containing sulfonic acid groups in the side chain can be suitably used. The above-mentioned anionic polymer containing sulfonic acid groups may be polymers having the same (single polymer; homopolymer) or different (copolymer; copolymer) repeating units, and when the anionic polymer containing sulfonic acid groups is a copolymer, the form of the copolymer may be any of block copolymers, random copolymers, graft copolymers, and alternating copolymers. In addition, the repeating structure of the above-mentioned copolymer may be composed of a repeating structure having a sulfonic acid group and a repeating structure not having a sulfonic acid group, or may be composed only of a repeating structure having two or more kinds of sulfonic acid groups.

[0043] Furthermore, the anionic groups in the sulfonic acid group-containing anionic polymer may be only sulfonic acid groups, or may contain, in addition to the sulfonic acid groups, one or more types of anionic groups other than sulfonic acid groups.

[0044] The anionic polymer containing sulfonic acid groups may be used alone or in combination of two or more. When the post-CMP cleaning composition contains two or more anionic polymers containing sulfonic acid groups, the content of the anionic polymer containing sulfonic acid groups is the total amount of the anionic polymers containing sulfonic acid groups. The anionic polymer containing sulfonic acid groups may be a commercially available product or a synthetic product.

[0045] The content of the anionic polymer containing sulfonic acid groups in the post-CMP cleaning composition is not particularly limited, but is preferably from 0.0002 to 2 mass %, more preferably from 0.001 to 0.2 mass %, even more preferably from 0.002 to 0.1 mass %, particularly preferably from 0.01 to 0.025 mass %, and most preferably from 0.015 to 0.02 mass %, based on the total mass of the post-CMP cleaning composition.

[0046] (Other polymers) The post-CMP cleaning composition according to the present invention may further contain other polymers in addition to the nitrogen-containing nonionic polymer and the anionic polymer containing a sulfonic acid group. As the other polymers, any of cationic polymers, amphoteric polymers, nitrogen-free nonionic polymers, and anionic polymers containing no sulfonic acid groups can be used. In addition, the other polymers are preferably water-soluble polymers. The water-soluble polymers referred to here refer to water-soluble polymers (homopolymers) having the same repeating structural units, or water-soluble polymers (copolymers) having different repeating structural units, and are typically compounds having a weight-average molecular weight (Mw) of 1000 or more.

[0047] Examples of cationic polymers include polyethyleneimine (PEI), polyvinylamine, polyallylamine, polyvinylpyridine, cationic acrylamide polymers, and the like.

[0048] 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 of amphoteric polymers include acrylic acid / dimethylaminoethyl methacrylic acid copolymers and acrylic acid / diethylaminoethyl methacrylic acid copolymers.

[0049] 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 the nitrogen-free nonionic polymer 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, dextrin derivatives, etc.

[0050] In one embodiment, the content of the polymer other than the nitrogen-containing nonionic polymer and the anionic polymer containing a sulfonic acid group is not particularly limited, but is, for example, 0.15 mass % or less, preferably 0.10 mass % or less, more preferably less than 0.10 mass %, and even more preferably 0.05 mass % or less, based on the total amount of the post-CMP cleaning composition. When the post-CMP cleaning composition contains two or more kinds of polymers other than the nitrogen-containing nonionic polymer and the anionic polymer containing a sulfonic acid group, the content of the polymer is the total amount of the polymers. In one embodiment, the post-CMP cleaning composition according to the present invention may not contain any polymer other than the nitrogen-containing nonionic polymer and the anionic polymer containing a sulfonic acid group. In addition, the post-CMP cleaning composition according to the present invention may or may not contain a non-nitrogen-containing nonionic polymer, but from the viewpoint of further exerting the effect of the nitrogen-containing nonionic polymer, it is preferable that the post-CMP cleaning composition according to the present invention does not contain a non-nitrogen-containing nonionic polymer.

[0051] (solvent) The post-CMP cleaning composition according to the present invention preferably contains a solvent. The solvent has a function of dispersing or dissolving each component. The solvent preferably contains water, and more preferably contains only water. The solvent may be a mixed solvent of water and an organic solvent for dispersing or dissolving each component. In this case, examples of the organic solvent used include acetone, acetonitrile, ethanol, methanol, isopropanol, glycerin, ethylene glycol, propylene glycol, and the like, which are organic solvents miscible with water. These organic solvents may be used without being mixed with water, and then each component may be dispersed or dissolved, and then mixed with water. These organic solvents may be used alone or in combination of two or more kinds.

[0052] The water is preferably water that contains as few impurities as possible from the viewpoint of preventing contamination of the polished object and inhibition of the action of other components. For example, water having a total transition metal ion content of 100 mass ppb or less is preferable. Here, 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, distillation, or other operations. Specifically, it is preferable to use, for example, deionized water (ion-exchanged water), pure water, ultrapure water, distilled water, etc. In this specification, the content of transition metal ions can be measured, for example, by ICP emission spectrometry.

[0053] (chelating agent) The post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) according to one embodiment of the present invention preferably contains a chelating agent. By containing a chelating agent in the post-CMP cleaning composition, the adsorption of the nitrogen-containing nonionic polymer to the polished surface of the polished object can be further promoted, and the residue can be further reduced. The chelating agent also has a function of adjusting the pH of the post-CMP cleaning composition. Furthermore, by forming a chelate with impurities such as metal ions, the function of the nitrogen-containing nonionic polymer and the anionic polymer containing a sulfonic acid group can be improved. As the chelating agent, an organic compound having at least one phosphoric acid group (-OP(=O)(OH)2) is preferable, and an organic compound having two or more phosphoric acid groups (-OP(=O)(OH)2) is more preferable. That is, in one embodiment, the post-CMP cleaning composition of the present invention further contains a chelating agent having two or more phosphoric acid 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, edetic acid, 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP, also known as etidronic acid), polyphosphoric acid, metaphosphoric acid, hexametaphosphoric acid, phosphonobutanetricarboxylic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, aminotrimethylenephosphonic acid, and salts thereof.

[0054] When the post-CMP cleaning composition contains a chelating agent, the content of the chelating agent is not particularly limited, but is preferably from 0.003 mass % to 0.2 mass %, more preferably from 0.005 mass % to 0.1 mass %, and even more preferably from 0.006 mass % to 0.06 mass %, based on the total mass of the post-CMP cleaning composition.

[0055] (Surfactant) The post-CMP cleaning composition of the present invention may further include a surfactant. The type of surfactant is not particularly limited, and may be any of nonionic, anionic, cationic, and amphoteric surfactants. In one embodiment, the molecular weight of the surfactant may be less than 1000.

[0056] Examples of nonionic surfactants include compounds other than the above-mentioned nitrogen-containing nonionic polymers, such as 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; alkanol amide types such as oleic acid diethanol amide; and allyl phenyl ether types such as polyoxyalkylene allyl phenyl ether. In addition, propylene glycol, diethylene glycol, monoethanolamine, alcohol ethoxylate, alkylphenol ethoxylate, tertiary acetylene glycol, alkanol amide, etc. can also be used as nonionic surfactants. In addition, since the above-mentioned nitrogen-containing nonionic polymers can function as nonionic surfactants, it is not necessary to add a separate nonionic surfactant.

[0057] Examples of anionic surfactants include compounds other than the above-mentioned anionic polymers containing sulfonic acid groups, 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 containing sulfonic acid groups can function as an anionic surfactant, so that it is not necessary to add a separate anionic surfactant.

[0058] 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.

[0059] Examples of amphoteric surfactants include lecithin, alkylamine oxide, alkylbetaines such as N-alkyl-N,N-dimethylammonium betaine, and sulfobetaines.

[0060] The surfactant may be used alone or in combination of two or more. In addition, the surfactant may be a commercially available product or a synthetic product.

[0061] When the post-CMP cleaning composition contains a surfactant, the lower limit of the surfactant content is preferably 0.01 mass% or more, and more preferably 0.05 mass% or more, based on the total mass of the post-CMP cleaning composition being 100 mass%. The upper limit of the surfactant content in the post-CMP cleaning composition is preferably 5 mass% or less, and more preferably 1 mass% or less, based on the total mass of the post-CMP cleaning composition being 100 mass%. When the post-CMP cleaning composition contains two or more surfactants, the surfactant content refers to the total amount of these.

[0062] <pH of post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition)> The pH of the post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) according to the present invention is less than 7.0. By the post-CMP cleaning composition having a pH of less than 7.0, the potential on the surface of the polished object becomes positive, and the anionic polymer containing a negatively charged sulfonic acid group is easily adsorbed on the surface of the polished object by electrostatic attraction, and the number of defects is reduced from the viewpoint of surface protection and from the viewpoint of making the zeta potential of the surface of the polished object during cleaning a negative value. When the post-CMP cleaning composition has a pH of 7.0 or more, the potential on the surface of the polished object becomes negative, and the anionic polymer containing a sulfonic acid group is electrostatically repulsed from the surface of the polished object, making it difficult to adsorb. As a result, the surface of the polished object becomes less protected, and residues (contaminants) are more likely to reattach to the surface of the polished object, resulting in an increase in the number of defects in the polished object. The pH of the post-CMP cleaning composition is preferably 2 or more and less than 7.0, more preferably 2 or more and less than 6, even more preferably 2.3 or more and less than 5.5, still more preferably 2.4 or more and less than 5, particularly preferably 2.4 or more and less than 4, and most preferably 2.4 or more and less than 3.

[0063] (pH adjuster) The pH of the post-CMP cleaning composition can be adjusted by the above-mentioned anionic polymer containing a sulfonic acid group or a chelating agent, but the post-CMP cleaning composition may further contain a pH adjuster.

[0064] The pH adjuster is not particularly limited, and any known pH adjuster used in the field of post-CMP cleaning compositions can be used, for example, any known acid, base, or salt 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 alcohol, ethyl ... Examples of suitable organic acids include carboxylic acids such as pinic acid, fumaric acid, maleic acid, aconitic acid, amino acids, and anthranilic acid, and 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; hydroxides of alkali metals such as potassium hydroxide (KOH); carbonates of alkali metals such as potassium carbonate (K2CO3) and sodium carbonate (Na2CO3); hydroxides of Group 2 elements; ammonia (ammonium hydroxide); and organic bases such as quaternary ammonium hydroxide compounds.

[0065] 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.

[0066] The content of the pH adjuster in the post-CMP cleaning composition may be appropriately selected so as to give the desired pH value of the post-CMP cleaning composition.

[0067] The pH of the post-CMP cleaning composition is measured by the method described in the Examples.

[0068] <Other additives> The post-CMP cleaning composition according to one embodiment of the present invention may contain other additives in any ratio as necessary within a range that does not impair the effects of the present invention. However, components other than the essential components of the post-CMP cleaning composition according to one embodiment of the present invention may cause foreign matter (residue), so it is desirable not to add them unless necessary, and even if they are added, 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, and the like. The post-CMP cleaning composition according to the present invention is acidic. In addition, the post-CMP cleaning composition according to the present invention contains a polymer. Therefore, among these, the post-CMP cleaning composition according to the present invention preferably contains an antifungal agent (preservative). When the post-CMP cleaning composition according to the present invention contains an antifungal agent, the antifungal agent that can be used is not particularly limited and can be appropriately selected depending on the type of polymer. Specifically, these include isothiazolin-based preservatives such as 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one; methyl parahydroxybenzoate (methyl parahydroxybenzoate), butyl parahydroxybenzoate (butyl parahydroxybenzoate); phenylphenols (2-phenylphenol, 3-phenylphenol, 4-phenylphenol); unsaturated fatty acids such as sorbic acid; 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 phenoxyethanol.

[0069] The above antifungal agents may be used alone or in combination of two or more.

[0070] When the post-CMP cleaning composition contains an antifungal agent, the lower limit of the content (concentration) of the antifungal agent is not particularly limited, but is preferably 0.00006 mass% or more, more preferably 0.0006 mass% or more, even more preferably 0.0008 mass% or more, and particularly preferably 0.001 mass% or more, based on the total mass of the post-CMP cleaning composition. The upper limit of the content (concentration) of the antifungal agent is not particularly limited, but is preferably 3 mass% or less, more preferably 0.6 mass% or less, even more preferably 0.3 mass% or less, and particularly preferably 0.06 mass% or less. That is, the content (concentration) of the antifungal agent in the post-CMP cleaning composition is preferably 0.00006 mass% or more and 3 mass% or less, more preferably 0.0006 mass% or more and 0.6 mass% or less, even more preferably 0.0008 mass% or more and 0.3 mass% or less, and particularly preferably 0.001 mass% or more and 0.06 mass% or less, based on the total mass of the post-CMP cleaning composition. Within such a range, a sufficient effect of inactivating or destroying microorganisms can be obtained. When the post-CMP cleaning composition contains two or more kinds of antifungal agents, the above content means the total amount of these.

[0071] That is, in one embodiment of the present invention, the post-CMP cleaning composition is substantially composed of a nitrogen-containing nonionic polymer, an anionic polymer containing a sulfonic acid group, water, and at least one selected from the group consisting of a chelating agent, an antifungal agent, an organic solvent, a pH adjuster, and a surfactant. In one embodiment of the present invention, the post-CMP cleaning composition is substantially composed of a nitrogen-containing nonionic polymer, an anionic polymer containing a sulfonic acid group, water, and at least one of a chelating agent, an antifungal agent, and an organic solvent. In one embodiment of the present invention, the post-CMP cleaning composition is substantially composed of a nitrogen-containing nonionic polymer, an anionic polymer containing a sulfonic acid group, water, and at least one of a chelating agent, an antifungal agent, and an organic solvent. In one embodiment of the present invention, the post-CMP cleaning composition is substantially composed of a nitrogen-containing nonionic polymer, an anionic polymer containing a sulfonic acid group, water, and at least one of a chelating agent, an antifungal agent, and an organic solvent.

[0072] In this embodiment, "the post-CMP cleaning 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 post-CMP cleaning composition), with the total mass of the post-CMP cleaning composition being 100% by mass. Preferably, the post-CMP cleaning composition is composed of X (the above total content=100% by mass). For example, "the post-CMP cleaning composition is substantially composed of a nitrogen-containing nonionic polymer, an anionic polymer containing sulfonic acid groups, water, and at least one of a chelating agent, an anti-fungal agent, and an organic solvent" means that the total content of the nitrogen-containing nonionic polymer, the anionic polymer containing sulfonic acid groups, water, and at least one of the chelating agent, the anti-fungal agent, and the organic solvent exceeds 99 mass % (upper limit: 100 mass %) (with respect to the post-CMP cleaning composition) assuming the total mass of the post-CMP cleaning composition to be 100 mass %, and it is preferable that the post-CMP cleaning composition is composed of a nitrogen-containing nonionic polymer, an anionic polymer containing sulfonic acid groups, water, and at least one of a chelating agent, an anti-fungal agent, and an organic solvent (the above total content = 100 mass %).

[0073] In order to further improve the foreign matter removal effect, the post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) of the present invention preferably does not substantially contain abrasive grains. Here, "substantially does not contain abrasive grains" refers to a case where the content of abrasive grains in the entire post-CMP cleaning composition is less than 0.1 mass % (preferably less than 0.01 mass %). That is, in one embodiment, the post-CMP cleaning composition of the present invention has a content of abrasive grains of less than 0.1 mass % with the total mass of the post-CMP cleaning composition being 100 mass %.

[0074] In order to further improve the foreign matter removal effect, the post-CMP cleaning composition of the present invention preferably does not substantially contain transition metal ions. Here, "substantially does not contain transition metal ions" refers to a case where the content of transition metal ions in the entire post-CMP cleaning composition is less than 0.1 mass % (preferably less than 0.01 mass %). That is, in one embodiment, the post-CMP cleaning composition of the present invention has a transition metal ion content of less than 0.1 mass % when the total mass of the post-CMP cleaning composition is taken as 100 mass %.

[0075] <Electrical Conductivity of Post-Chemical Mechanical Polishing Cleaning Composition (Post-CMP Cleaning Composition)> The electrical conductivity (EC) of the post-CMP cleaning composition according to the present invention is not particularly limited, but is preferably 0.45 mS / cm or more, and more preferably 0.50 mS / cm or more. The upper limit of the electrical conductivity (EC) of the post-CMP cleaning composition according to the present invention is not particularly limited, but is preferably 0.65 mS / cm or less, and more preferably 0.60 mS / cm or less. That is, the electrical conductivity (EC) of the post-CMP cleaning composition according to the present invention is preferably 0.45 mS / cm or more and 0.65 mS / cm or less, and more preferably 0.50 mS / cm or more and 0.60 mS / cm or less. The electrical conductivity of the post-CMP cleaning composition can be adjusted by the type and amount of the anionic polymer containing a sulfonic acid group, the pH adjuster, and the like. The electrical conductivity (EC) of the post-CMP cleaning composition can be measured by the method described in the Examples.

[0076] <Water contact angle of polished object during post-CMP cleaning treatment with post-CMP cleaning composition> As described above, it is presumed that the use of the post-CMP cleaning composition according to the present invention allows the nitrogen-containing nonionic polymer (and anionic polymer containing sulfonic acid groups) to adsorb to the surface of the polished object, thereby removing the residues present on the surface of the polished object. Here, a small water contact angle on the surface of the polished object indicates high wettability of the surface, which is believed to be due to the nitrogen atom portion of the nitrogen-containing nonionic polymer being adsorbed to the surface of the polished object, improving hydrophilicity. Therefore, the fact that the surface of the polished object shows high wettability is believed to support the action of the nitrogen-containing nonionic polymer according to the above mechanism.

[0077] Therefore, it is preferable that the water contact angle of the polished object during the post-CMP cleaning process is small. As an example, when the polished object is a substrate having a film containing polysilicon (Poly-Si substrate), the water contact angle is acceptable if it is 20° or less, and preferably 15° or less. As an example, when the polished object is a substrate having a film containing silicon oxide (e.g., a substrate having a TEOS film), the water contact angle is acceptable if it is 15° or less, and preferably 10° or less. As an example, when the polished object is a substrate having a film containing silicon nitride (Si3N4 substrate), the water contact angle is acceptable if it is 17° or less, and preferably 13° or less. The water contact angle of the polished object can be measured by the method described in the examples.

[0078] <Zeta potential of polished object during post-CMP cleaning treatment with post-CMP cleaning composition> As described above, the post-CMP cleaning composition according to the present invention contains an anionic polymer containing a sulfonic acid group, so that the zeta potentials of both the surface of the polished object and the surface of the residue (contaminant) can be controlled to be negative. Therefore, it is presumed that the electrostatic repulsion is utilized to efficiently detach the residue (contaminant) from the polished object, and the reattachment to the polished object is suppressed.

[0079] Therefore, the zeta potential of the surface of the polished object to be polished during the post-CMP cleaning process is preferably a negative value. As an example, when the polished object to be polished is a substrate having a film containing polysilicon (Poly-Si substrate), the zeta potential is acceptable if it is -5 mV or less, and is preferably less than -5 mV. As an example, when the polished object to be polished is a substrate having a film containing silicon oxide (e.g., a substrate having a TEOS film), the zeta potential is acceptable if it is -5 mV or less, and is preferably -10 mV or less. As an example, when the polished object to be polished is a substrate having a film containing silicon nitride (Si3N4 substrate), the zeta potential is acceptable if it is -5 mV or less, and is preferably -15 mV or less. The zeta potential of the surface of the polished object to be polished during the post-CMP cleaning process can be estimated by the method described in the examples.

[0080] <Method for Producing Post-Chemical Mechanical Polishing Cleaning Composition (Post-CMP Cleaning Composition)> The method for producing the post-CMP cleaning composition of the present invention can be obtained by, for example, stirring and mixing a nitrogen-containing nonionic polymer, an anionic polymer containing a sulfonic acid group, a solvent, and other components as necessary. The temperature at which each component is 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.

[0081] <Post-chemical mechanical polishing cleaning treatment method (post-CMP cleaning treatment method; surface treatment method)> Another aspect of the present invention is a post-chemical mechanical polishing cleaning treatment method (also referred to as "post-CMP cleaning treatment method" or "surface treatment method" in this specification) which includes subjecting a polished object to a post-chemical mechanical polishing cleaning treatment (also referred to as "post-CMP cleaning treatment" or "surface treatment" in this specification) using the post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition). In this specification, the post-chemical mechanical polishing cleaning treatment method (post-CMP cleaning treatment method) refers to a method for reducing residues on the surface of a polished object, and is a method for performing cleaning in a broad sense.

[0082] According to the post-CMP cleaning treatment method of one embodiment of the present invention, residues remaining on the surface of a polished object can be sufficiently removed. That is, according to another embodiment of the present invention, a method for reducing residues on the surface of a polished object is provided, in which the polished object is subjected to a post-chemical mechanical polishing cleaning treatment (post-CMP cleaning treatment) using the post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition). In addition, according to another embodiment of the present invention, a method for post-chemical mechanical polishing cleaning treatment (post-CMP cleaning treatment method) is also provided, in which the polished object containing a silicon-containing material is subjected to a post-chemical mechanical polishing cleaning treatment (post-CMP cleaning treatment) using the post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) to reduce residues on the surface of the polished object.

[0083] A post-CMP cleaning treatment method according to one embodiment of the present invention is carried out by directly contacting the post-CMP cleaning composition according to the present invention with an object that has already been polished.

[0084] The post-chemical mechanical polishing cleaning treatment method (post-CMP cleaning treatment method) mainly includes (I) a method using a rinse polishing treatment and (II) a method using a cleaning treatment. That is, according to one embodiment of the present invention, the post-chemical mechanical polishing cleaning treatment (post-CMP cleaning treatment) is preferably performed by a rinse polishing treatment or a cleaning treatment. That is, the post-chemical mechanical polishing cleaning treatment method (post-CMP cleaning treatment method) is preferably a rinse polishing treatment method or a cleaning treatment method. The rinse polishing treatment and the cleaning treatment 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 described below.

[0085] (I) Rinse polishing treatment The post-CMP cleaning composition according to the present invention is preferably used in a rinse polishing process. That is, the post-CMP cleaning 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) to which a polishing pad is attached, for the purpose of removing foreign matter on the surface of the polishing object after the final polishing (finish polishing) of the polishing object. At this time, the rinse polishing process is performed by directly contacting the post-CMP cleaning composition according to the present invention with the polished object. As a result, the foreign matter on the surface of the polished object is removed by the frictional force (physical action) of the polishing pad and the chemical action of the post-CMP cleaning composition. Among the foreign matter, particles and organic residues are particularly easily removed by physical action. Therefore, in the rinse polishing process, the particles and organic residues can be effectively removed by utilizing friction with the polishing pad on the polishing table (platen).

[0086] 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, for reducing residues on the surface of an object to be subjected to post-CMP cleaning treatment using a polishing pad.

[0087] Specifically, the rinse polishing process can be carried out by placing the polished surface of the object to be polished after the polishing process on a polishing table (platen) of a polishing apparatus, contacting the polishing pad with the polished semiconductor substrate, and supplying the post-CMP cleaning composition to the contact area while sliding the polished object to be polished and the polishing pad relative to one another.

[0088] As a polishing device, a general polishing device can be used that is equipped with a holder for holding the object to be polished and a motor whose rotation speed can be changed, and has a polishing platen to which a polishing pad (polishing cloth) can be attached.

[0089] The rinse polishing process can be carried out by using either a single-sided polishing machine or a double-sided polishing machine. In addition, the polishing machine is preferably equipped with a nozzle for discharging the post-CMP cleaning composition in addition to a nozzle for discharging the polishing composition. The operating conditions of the polishing machine during the rinse polishing process are not particularly limited, and can be appropriately set by a person skilled in the art.

[0090] The polishing pad may be made of any material, including general nonwoven fabric, polyurethane, and porous fluororesin, without any particular limitations. The polishing pad is preferably provided with grooves for storing the post-CMP cleaning composition.

[0091] There are no particular limitations on the rinse polishing conditions. For example, the rotation speed of the polishing plate 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 polished object (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 post-CMP cleaning composition to the polishing pad is not particularly limited, and for example, a method of continuously supplying the composition using a pump or the like (flowing over) is used. There is no limit to the amount of supply, but it is preferable that the surface of the polishing pad is always covered with the post-CMP cleaning composition, and the supply rate 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.

[0092] After the rinse polishing process using the post-CMP cleaning composition according to one embodiment of the present invention, the polished object (object to be subjected to post-chemical mechanical polishing cleaning process) is preferably pulled up and removed while being sprayed with the post-CMP cleaning composition according to one embodiment of the present invention.

[0093] (II) Cleaning treatment The post-CMP cleaning composition according to the present invention may be used in a cleaning process. That is, the post-CMP cleaning composition according to one embodiment of the present invention can be preferably used as a cleaning composition. The cleaning process is preferably performed for the purpose of removing foreign matter on the surface of a polished object (object to be cleaned) after a final polish (finish polish) is performed on the object to be polished, after the above-mentioned rinse polishing process is performed, or after another rinse polishing process is performed using a rinse polishing composition other than the post-CMP cleaning composition of the present invention. The cleaning process and the above-mentioned rinse polishing process are classified according to the location where these processes are performed, and the cleaning process 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 process, the post-CMP cleaning composition according to the present invention can be directly contacted with the polished object to be polished to remove foreign matter on the surface of the object.

[0094] 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 a polished object while holding the polished object, and the surface of the polished object is rubbed with the cleaning brush while a post-CMP cleaning composition is supplied to the contact portion, and (ii) a method in which the polished object is immersed in the post-CMP cleaning composition and subjected to ultrasonic treatment or stirring (dip type), etc. In such a method, 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 stirring, and the chemical action of the post-CMP cleaning composition.

[0095] In the above method (i), the method of bringing the post-CMP cleaning composition into contact with the polished object to be polished is not particularly limited, but examples include a spin type in which the polished object is rotated at high speed while the post-CMP cleaning composition is flowed from a nozzle onto the polished object, and a spray type in which the post-CMP cleaning composition is sprayed onto the polished object to clean it.

[0096] From the viewpoint of more efficient decontamination in a short period of time, the cleaning treatment is preferably of the spin type and / or spray type, and more preferably of the spin type.

[0097] Apparatuses for carrying out such cleaning treatment include batch-type cleaning apparatuses which simultaneously perform post-CMP cleaning on a plurality of polished objects housed in a cassette, and single-wafer cleaning apparatuses which perform post-CMP cleaning on a single polished object mounted on a holder, etc. From the viewpoint of shortening the cleaning time, etc., a method using a single-wafer cleaning apparatus is preferred.

[0098] Furthermore, as an apparatus for carrying out the cleaning process, there is a polishing apparatus equipped with a cleaning device for scrubbing the polished object with a cleaning brush after removing the polished object from the polishing table (platen). By using such a polishing apparatus, the cleaning process of the polished object can be carried out more efficiently.

[0099] As such a polishing device, a general polishing device having a holder for holding a polished object, a motor capable of changing the rotation speed, a cleaning brush, etc. can be used. As the polishing device, either a single-sided polishing device or a double-sided polishing device 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 device as the polishing device used in the rinse polishing process.

[0100] 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.

[0101] There are no particular limitations on the cleaning conditions, and they can be set appropriately depending on the type of 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 polished object is 10 rpm (0.17 s -1 ) or more 100rpm(1.67s -1 ) or less. 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 post-CMP cleaning composition to the cleaning brush is not particularly limited, and for example, a method of continuously supplying the composition using a pump or the like (flowing) is adopted. There is no limit to the amount of supply, but it is preferable that the cleaning brush and the surface of the polished object are always covered with the post-CMP cleaning composition, and the supply rate is preferably 10 mL / min or more and 5000 mL / min or less. The cleaning time is also not particularly limited, but it is preferably 5 seconds or more and 180 seconds or less for the step using the post-CMP cleaning composition according to one embodiment of the present invention. If the amount of supply is within such a range, foreign matter can be removed more effectively.

[0102] The temperature of the post-CMP cleaning composition during cleaning is not particularly limited and may usually be 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.

[0103] In the above method (ii), the conditions for the cleaning method by immersion are not particularly limited, and any known method can be used.

[0104] A water rinse may be performed before carrying out the post-CMP cleaning treatment by the above method (I) or (II).

[0105] (Post-cleaning process) In addition, as a post-CMP cleaning method, it is preferable to further clean the polished object after the post-CMP cleaning process (I) or (II) using the post-CMP cleaning composition according to one embodiment of the present invention. In this specification, this cleaning process is referred to as a post-cleaning process. The post-cleaning process is not particularly limited, but examples thereof include a method of simply pouring water over the polished object, a method of simply immersing the polished object in water, and the like. In addition, similar to the post-CMP cleaning process by the method (II) described above, a method of rubbing the surface of the polished object with a cleaning brush while holding the polished object and supplying water or an aqueous solution (e.g., an NH3 aqueous solution) to the contact portion or supplying water and an aqueous solution (e.g., an NH3 aqueous solution) in any order (supplying water and then supplying an aqueous solution, or supplying an aqueous solution and then supplying water) (brush cleaning), a method of immersing the polished object in water and performing ultrasonic treatment or stirring (dip type), and the like. Among these, a preferred method is to hold the ground object and bring the cleaning brush into contact with one or both sides of the ground object, and to 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 (supplying water and then the aqueous solution, or supplying the aqueous solution and then the water) while scrubbing the surface of the ground object with the cleaning brush. Note that the apparatus and conditions for the post-cleaning process can be found in the explanation of the process in (II) above. Here, it is particularly preferred to use deionized water as the water used in the post-cleaning process.

[0106] By carrying out a post-CMP cleaning treatment with the post-CMP cleaning composition according to one embodiment of the present invention, the residues are rendered extremely easy to remove, and therefore, by carrying out a post-CMP cleaning treatment with the post-CMP cleaning composition according to one embodiment of the present invention and then carrying out a further cleaning treatment with water, the residues are extremely well removed.

[0107] In addition, the polished object after the post-CMP cleaning process or after the post-cleaning process is preferably dried by removing water droplets adhering to the surface with a spin dryer, etc. The surface of the polished object may also be dried by air blow drying.

[0108] <Method of manufacturing semiconductor substrate> The post-CMP cleaning method according to one embodiment of the present invention is preferably applied when the polished object 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, in which the polished object is a polished semiconductor substrate, and the polished semiconductor substrate is subjected to the post-CMP cleaning method to reduce residues on the surface of the polished semiconductor substrate. Thus, according to the present invention, there is provided a method for producing a semiconductor substrate, in which the polished object is a polished semiconductor substrate, and the method includes 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-containing materials, for example, silicon oxide, polysilicon, and silicon nitride, using a polishing composition containing abrasive grains, and a post-chemical mechanical polishing cleaning treatment step (also referred to as a "post-CMP cleaning treatment step" or a "surface treatment step" in this specification) of reducing residues containing abrasive grains on the surface of the polished semiconductor substrate using the post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition).

[0109] Details of the semiconductor substrate to which this manufacturing method is applied are as described above for the polished object to be post-CMP cleaned with the post-CMP cleaning composition.

[0110] In addition, the method for producing a semiconductor substrate is not particularly limited as long as it includes a post-CMP cleaning process for the surface of a polished semiconductor substrate using a post-CMP cleaning composition according to one embodiment of the present invention. For example, such a production method includes a method having a polishing process and a cleaning process for forming a polished semiconductor substrate. Another example includes a method having a rinse polishing process between the polishing process and the cleaning process in addition to the polishing process and the cleaning process. Each of these processes will be described below.

[0111] [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.

[0112] The polishing step is not particularly limited as long as it is a step of polishing a semiconductor substrate, but is a chemical mechanical polishing (CMP) step. The polishing step may be a polishing step consisting of a single step or a polishing step consisting of multiple steps. Examples of the polishing step consisting of multiple steps include a step of performing a finish polishing step after a preliminary polishing step (rough polishing step), and a step of performing one or more secondary polishing steps after a primary polishing step, and then performing a finish polishing step. The post-CMP cleaning treatment step using the post-CMP cleaning composition according to the present invention is preferably performed after the above-mentioned finish polishing step.

[0113] As the polishing composition, a known polishing composition can be appropriately used according to the characteristics of the semiconductor substrate.The polishing composition is not particularly limited, but for example, a composition containing abrasive grains, a solvent, a water-soluble polymer, and a pH adjuster can be preferably used.Specific examples of such polishing compositions include a polishing composition containing silicon oxide (for example, colloidal silica), polyvinylpyrrolidone, ammonia, and water.

[0114] The abrasive grains may be any of inorganic particles, organic particles, and 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 polymethylmethacrylate (PMMA) particles. The abrasive grains may be commercially available products 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.

[0115] 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. If it is within such a range, it can be used suitably in the rough polishing process because it can maintain a high polishing rate. Moreover, 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. If it is within such a range, it is possible to further suppress the occurrence of defects on the surface of the polished object after polishing. The average primary particle size of the abrasive grains is calculated based on the specific surface area of ​​the abrasive grains measured by the BET method, for example.

[0116] 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 such a 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 such a range, defects on the surface of the polished object 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 a model "FPAR-1000" manufactured by Otsuka Electronics Co., Ltd. or an equivalent product.

[0117] When the polishing composition is used as it is as a polishing liquid, the content of the abrasive grains is preferably 0.1 mass% or more, more preferably 0.4 mass% or more, and even more preferably 1.0 mass% or more, based on the polishing composition. The polishing speed is improved by increasing the content of the abrasive grains. When the polishing composition is used as it is as a polishing liquid, the content of the abrasive grains is usually 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% or less, and even more preferably 2 mass% or less, from the viewpoint of preventing scratches. It is also preferable to reduce the content of the abrasive grains from the viewpoint of economic efficiency. In addition, when two or more kinds of abrasive grains are used in combination, the above content refers to the total content of two or more kinds of abrasive grains.

[0118] The pH adjuster and the solvent are the same as those defined in the above sections (pH adjuster) and (solvent), respectively, and therefore the explanation thereof will be omitted here.

[0119] As the polishing device, a general polishing device can be used that is 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. As the polishing device, either a single-sided polishing device or a double-sided polishing device may be used.

[0120] The polishing pad may be made of any material, including general nonwoven fabric, polyurethane, porous fluororesin, etc. It is preferable that the polishing pad has grooves formed thereon to allow the polishing liquid to accumulate.

[0121] There are no particular limitations on the polishing conditions. For example, the rotation speed of the polishing plate 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 the composition 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 not particularly limited, but it is preferably 5 seconds or more and 180 seconds or less for the process using the polishing composition.

[0122] [Post-chemical mechanical polishing cleaning process (Post-CMP cleaning process)] The post-CMP cleaning process refers to a process of reducing residues on the surface of a polished object using the post-CMP cleaning composition according to the present invention. In the manufacturing method of a semiconductor substrate, a cleaning process may be performed as a post-CMP cleaning process after a rinse polishing process, or only a rinse polishing process or only a cleaning process may be performed.

[0123] (Rinse polishing process) The rinse polishing process may be provided between the polishing process and the cleaning process in the method for manufacturing a semiconductor substrate. The rinse polishing process is a process for reducing foreign matter on the surface of a polished object (polished semiconductor substrate) by a post-CMP cleaning process method (rinse polishing process method) according to one embodiment of the present invention.

[0124] The details of the rinse polishing method used in the rinse polishing step are as described above in the explanation of the rinse polishing treatment.

[0125] (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 for reducing foreign matter on the surface of a polished object (polished semiconductor substrate) by a post-CMP cleaning treatment method (cleaning method) according to one embodiment of the present invention.

[0126] Details of the cleaning method used in the cleaning step are as described above in the description of the cleaning method.

[0127] Although the embodiments of the present invention have been described in detail, it is apparent that the same are illustrative and exemplary, not restrictive, and the scope of the present invention should be interpreted by the appended claims.

[0128] The present invention encompasses the following aspects and configurations. 1. A post-chemical mechanical polishing cleaning composition comprising a nitrogen-containing nonionic polymer and an anionic polymer containing a sulfonic acid group, the content of the nitrogen-containing nonionic polymer being more than 0.1 mass % and less than 1.0 mass % based on the total amount of the post-chemical mechanical polishing cleaning composition, and having a pH of less than 7.0: 2. The post chemical mechanical polishing cleaning composition according to claim 1, wherein the nitrogen-containing nonionic polymer has an amide bond. 3. The post chemical mechanical polishing cleaning composition according to 1. or 2. above, wherein the weight average molecular weight of the nitrogen-containing nonionic polymer is 80,000 or less. 4. The post chemical mechanical polishing cleaning composition according to any one of 1. to 3. above, 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 post-chemical mechanical polishing cleaning composition according to any one of 1. to 4. above, further comprising a chelating agent having two or more phosphate groups: 6. A post-chemical mechanical polishing cleaning composition according to any one of 1. to 5. above, which is substantially free of abrasive grains: 7. A post-chemical mechanical polishing cleaning treatment method, comprising surface-treating a polished object containing at least one selected from the group consisting of silicon oxide, polysilicon and silicon nitride using the post-chemical mechanical polishing cleaning composition according to any one of 1. to 6. above, thereby reducing residues on the surface of the polished object: 8. The post-chemical mechanical polishing cleaning treatment method according to claim 7, which is a rinse polishing treatment method or a cleaning treatment method: 9. A method for producing a semiconductor substrate, comprising: a polishing step in which the polished object to be polished is a polished semiconductor substrate, the polishing step comprising polishing a pre-polished 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; and a post-chemical mechanical polishing cleaning treatment step in which a post-chemical mechanical polishing cleaning composition described in any one of 1. to 6. above is used to reduce residues containing the abrasive grains on the surface of the polished semiconductor substrate. EXAMPLES

[0129] 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 performed under the conditions of room temperature (25°C) / relative humidity of 40% RH or more and 50% RH or less.

[0130] [Polymer preparation] The following nitrogen-containing nonionic polymer and sulfonic acid group-containing anionic polymer were prepared.

[0131] "Nitrogen-containing nonionic polymer" Polyvinylpyrrolidone (Daiichi Kogyo Seiyaku Co., Ltd., product name Pitzcol (registered trademark) K30A); weight average molecular weight 45,000 "Anionic polymers containing sulfonic acid groups" - 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.

[0132] [Measurement of weight average molecular weight (Mw) of polymer] The weight average molecular weight (Mw) of the polymer was measured by gel permeation chromatography (GPC) using the weight average molecular weight (converted into polyethylene glycol). The weight average molecular weight was measured 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% acetic acid solution Flow rate: 1mL / min Detector: ELSD temp. 40℃, Gain 8, N2GAS 350kPa Oven temperature: 40℃ Injection volume: 40μL.

[0133] [Measurement of pH of post-CMP cleaning compositions] The pH of the post-CMP cleaning composition (liquid temperature: 25° C.) was confirmed using a pH meter (manufactured by Horiba, Ltd., product name: LAQUA (registered trademark)).

[0134] [Electrical Conductivity of Post-CMP Cleaning Compositions] The electrical conductivity (EC) of the post-CMP cleaning composition was measured using a benchtop electrical conductivity meter (manufactured by Horiba, Ltd., model number: DS-71 LAQUA (registered trademark)).

[0135] Preparation of Post-CMP Cleaning Composition Example 1 A post-CMP cleaning composition A1 was prepared by mixing and stirring the following for 5 minutes at 25° C.: polyvinylpyrrolidone having a weight average molecular weight of 45,000 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 containing sulfonic acid groups; water (deionized water) as a solvent; 1-hydroxyethane-1,1-diphosphonic acid (hereinafter, “HEDP”) (product name: Dequest (registered trademark) 2010EL (Italmatch Japan Co., Ltd.)) as a chelating agent; ammonia (product name: EL ammonia water (Kanto Chemical Co., Ltd.)) as a pH adjuster; and a mold inhibitor (preservative) (SANAIVAC R-30 (manufactured by SANAI OBURY Co., Ltd.)).

[0136] Here, the content of the nitrogen-containing nonionic polymer in the post-CMP cleaning composition was 0.15 mass %, based on the total mass of the post-CMP cleaning composition A1; the content of the anionic polymer containing sulfonic acid groups was 0.02 mass %, based on the total mass of the post-CMP cleaning composition A1; the content of the chelating agent was 0.024 mass %, based on the total mass of the post-CMP cleaning composition A1; the content of the pH adjuster was an amount such that the pH of the post-CMP cleaning composition A1 was 2.8; and the content of the anti-fungal agent was 0.0012 mass %, based on the total mass of the post-CMP cleaning composition A1.

[0137] (Examples 2 to 11, Comparative Examples 1 to 5) Post-CMP cleaning compositions A2 to A11 and post-CMP cleaning compositions B1 to B5 were prepared in the same manner as in Example 1, except that the contents of the nitrogen-containing nonionic polymer, the anionic polymer containing a sulfonic acid group, and the chelating agent were changed as shown in Table 1 below.

[0138] In Table 1, the nitrogen-containing nonionic polymer is denoted as "N-containing nonionic polymer," and the (acrylic acid / sulfonic acid) copolymer is denoted as "AA / SA copolymer."

[0139] In addition, in Table 1, "PVP" represents polyvinylpyrrolidone, and "PVA" represents polyvinyl alcohol. In addition, in Table 1, the notation "-" (hyphen) indicates that the compound was not added.

[0140] [Table 1]

[0141] [Preparation of polished object] A polished object was prepared after being polished by the following chemical mechanical polishing (CMP) process.

[0142] (CMP process) The objects to be polished were (1) a silicon wafer (also referred to as a Poly-Si substrate or polysilicon substrate in this specification) (300 mm, blanket wafer, manufactured by D&X Co., Ltd.) with a 5000 Å thick polycrystalline silicon film formed on its surface, (2) a silicon wafer (also referred to as a TEOS substrate) (300 mm, blanket wafer, manufactured by Advantec Co., Ltd.) with a 10000 Å thick TEOS film formed on its surface, and (3) a silicon wafer (also referred to as a Si3N4 substrate) (300 mm, blanket wafer, manufactured by Advantec Co., Ltd.) with a 2500 Å thick silicon nitride (Si3N4) film formed on its surface. Note that 1 Å=0.1 nm.

[0143] The Poly-Si substrate, TEOS substrate, and Si3N4 substrate prepared above were polished using a polishing composition (composition: 10 mass% colloidal silica (average primary particle size 35 nm, average secondary particle size 70 nm), polyvinylpyrrolidone (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 0.25 mass% Pitzcol (registered trademark) K-30A, and 0.33 mass% ammonia (ammonium hydroxide) diluted 5 times) under the following conditions. Note that 1 rpm = 0.017 s -1 It is.

[0144] <Polishing equipment and polishing conditions> Polishing equipment: Ebara Corporation FREX300E Polishing pad: Fujibo Holdings Co., Ltd. Polyurethane foam pad H800 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.

[0145] [Post-Chemical Mechanical Polishing Cleaning Process (Post-CMP Cleaning Process)] (Rinse polishing) After the surface of the object to be polished was polished in the above CMP step, the polished object was removed from the polishing table (platen). Next, in the same polishing apparatus, the polished object was mounted on another polishing table (platen), and the polished surface was subjected to a rinse polishing treatment using the post-CMP cleaning compositions A1 to A11 and B1 to B5 prepared in the above Examples 1 to 11 and Comparative Examples 1 to 5 under the following conditions.

[0146] <Rinse polishing device and rinse polishing conditions> Grinding pressure: 1.0psi Plate rotation speed: 80 rpm Head rotation speed: 80 rpm Post-CMP cleaning composition supply: flow-through Post-CMP cleaning composition feed rate: 300 mL / min Polishing time: 60 seconds.

[0147] (Post-wash) After the rinse-polishing process, the substrate surface was brush-cleaned using a 0.3 mass % NH3 aqueous solution for 20 seconds, and then washed with deionized water for 40 seconds to obtain a polished object that had been rinse-polished.

[0148] [Evaluation 1: Residue count measurement] The number of residues on the surface of each of the TEOS substrate, Poly-Si substrate, and Si3N4 substrate, which were polished and polished in the above [Preparation of polished object] section and cleaned by the method described in the above [Post-chemical mechanical polishing cleaning treatment (post-CMP cleaning treatment)] section, was evaluated. Specifically, the number of residues with a diameter of more than 40 nm for the TEOS substrate and Si3N4 substrate, and more than 70 nm for the Poly-Si substrate, was counted using an optical inspection machine Surfscan (registered trademark) SP5 manufactured by KLA-Tencor Corporation, for the remaining parts excluding the part 5 mm wide from the outer edge of one side of the polished TEOS substrate, Poly-Si substrate, and Si3N4 substrate (the part from 0 mm wide to 5 mm wide when the outer edge is 0 mm). After that, the number of abrasive grain residues and the number of organic residues were measured by SEM observation using Review SEM RS6000 manufactured by Hitachi High-Tech Corporation for the polished TEOS substrate, Poly-Si substrate, and Si3N4 substrate. First, 100 residues were sampled from the remaining area, excluding a 5 mm wide area from the outer edge of one side of the polished TEOS substrate, Poly-Si substrate, and Si3N4 substrate, using SEM observation. Next, the type of residue (abrasive grain or organic residue) was determined from the 100 sampled residues using visual SEM observation, and the number of abrasive grain residues (SiO2 residues) and organic residues (pad dust, polymers, etc.) was confirmed. The results are shown in Table 2 below.

[0149] It is preferable that the number of abrasive grain residues (SiO2 residues) is as small as possible. As an example, the number of abrasive grain residues with a diameter of 70 nm or more on a Poly-Si substrate is acceptable if it is 25 or less, preferably 20 or less, more preferably 15 or less, even more preferably 10 or less, and particularly preferably 9 or less. As an example, the number of abrasive grain residues with a diameter of 40 nm or more on a TEOS substrate is acceptable if it is 300 or less, and preferably 250 or less. As an example, the number of abrasive grain residues with a diameter of 40 nm or more on a Si3N4 substrate is acceptable if it is 300 or less, and preferably 250 or less.

[0150] In addition, it is preferable that the number of organic residues (such as pad debris and polymers) is as small as possible. As an example, the number of organic residues (such as pad debris and polymers) with a diameter of 70 nm or more on a Poly-Si substrate is acceptable if it is 150 or less, preferably 100 or less, and more preferably 90 or less. As an example, the number of organic residues (such as pad debris and polymers) with a diameter of 40 nm or more on a TEOS substrate is acceptable if it is 200 or less, preferably 150 or less, and more preferably 130 or less. As an example, the number of organic residues (such as pad debris and polymers) with a diameter of 40 nm or more on a Si3N4 substrate is acceptable if it is 50 or less, and preferably 30 or less.

[0151] [Evaluation 2: Water contact angle measurement (wettability)] The water contact angles of Poly-Si substrates, TEOS substrates, and Si3N4 substrates after rinse polishing treatment using the post-CMP cleaning compositions A1 to A11 and B1 to 4 prepared in the above Examples 1 to 11 and Comparative Examples 1 to 5 were measured.

[0152] Each of the substrates (Poly-Si substrate, TEOS substrate, and Si3N4 substrate) used in the above section [Preparation of polished object to be polished] was cut into 60 mm square to prepare test substrates. Then, polishing was performed in the same manner as in the above section [Preparation of polished object to be polished] to obtain polished objects. After that, the polished object to be polished was mounted on a polishing table (platen) in the following polishing apparatus, and a rinse polishing process was performed using the post-CMP cleaning compositions A1 to A11 and B1 to 5 prepared in the above Examples 1 to 11 and Comparative Examples 1 to 5 under the following conditions.

[0153] <Rinse polishing device and rinse polishing conditions (for wettability evaluation)> Polishing equipment: Engis Japan Co., Ltd. Lapping machine EJ-380IN-C Polishing pad: Fujibo Holdings Co., Ltd. Polyurethane foam pad H800 Conditioner (dresser): Nylon brush (3M) Grinding pressure: 1.0psi Polishing platen rotation speed: 60 rpm Head rotation speed: 60 rpm Post-CMP cleaning composition supply: flow-through Post-CMP cleaning composition feed rate: 100 mL / min Polishing time: 60 seconds.

[0154] After the rinse-polishing process was performed as described above, no post-cleaning process was performed, and the moisture on the surface was removed by air shower to obtain a polished object that had been rinse-polished. The water contact angle was then measured using the θ / 2 method. For the measurement, a contact angle evaluation device DMo-501 manufactured by Kyowa Interface Science Co., Ltd. was used. The results are shown in Table 2 below.

[0155] [Evaluation 3: Zeta potential measurement] The test substrates of the Poly-Si substrate, TEOS substrate, and Si3N4 substrate used in the above [Evaluation 2: Measurement of water contact angle (wettability)] were prepared as measurement objects. The measurement objects were placed in a solid zeta potential measuring device SurPASS3 (zeta potential meter) manufactured by Anton Paar Japan Co., Ltd. Next, the post-CMP cleaning compositions A1 to A11 and B1 to 5 prepared in the above Examples 1 to 11 and Comparative Examples 1 to 5 were passed through the measurement objects, respectively, and the zeta potentials (mV) of these measurement objects were measured. This value was taken as the zeta potential of each wafer during rinse polishing. The results are shown in Table 2 below.

[0156] [Table 2]

[0157] As is clear from Table 2 above, the post-CMP cleaning compositions A1 to A11 of Examples 1 to 11 were found to be able to reduce residues on the surface of a polished object containing a silicon-containing material, compared to the post-CMP cleaning compositions B1 to B5 of Comparative Examples 1 to 5.

[0158] This application is based on Japanese Patent Application No. 2023-167704, filed on September 28, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A nitrogen-containing nonionic polymer and an anionic polymer containing a sulfonic acid group, The content of the nitrogen-containing nonionic polymer is more than 0.1 mass % and less than 1.0 mass % based on the total amount of the post chemical mechanical polishing cleaning composition; A post-chemical mechanical polishing cleaning composition having a pH of less than 7.

0.

2. The post-chemical mechanical polishing cleaning composition of claim 1 , wherein the nitrogen-containing nonionic polymer has an amide bond.

3. 2. The post chemical mechanical polishing cleaning composition of claim 1, wherein the weight average molecular weight of the nitrogen-containing nonionic polymer is 80,000 or less.

4. 2. The post chemical mechanical polishing cleaning composition according to claim 1, 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 post-chemical mechanical polishing cleaning composition of claim 1 further comprising a chelating agent having two or more phosphate groups.

6. The post chemical mechanical polishing cleaning composition of claim 1 which is substantially free of abrasives.

7. A post-chemical mechanical polishing cleaning treatment method, comprising surface-treating a polished object containing at least one selected from the group consisting of silicon oxide, polysilicon, and silicon nitride, using the post-chemical mechanical polishing cleaning composition according to any one of claims 1 to 6, thereby reducing residues on the surface of the polished object.

8. 8. The post chemical mechanical polishing cleaning process of claim 7, which is a rinse polishing process or a cleaning process.

9. the polished object is a polished semiconductor substrate; a polishing step of obtaining a polished semiconductor substrate by polishing an unpolished 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; A post-chemical mechanical polishing cleaning treatment step of reducing the abrasive-containing residue on the polished semiconductor substrate surface using the post-chemical mechanical polishing cleaning composition according to any one of claims 1 to 6; A method for manufacturing a semiconductor substrate comprising the steps of:

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