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

Abstract

The invention relates to a composition for cleaning after chemical mechanical polishing, a method for cleaning after chemical mechanical polishing, and a method for manufacturing a semiconductor substrate. The present invention provides a scheme capable of sufficiently removing residue remaining on the surface of a polished object including a silicon-containing material. The present invention is a post-chemical-mechanical-polishing cleaning composition containing 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% by mass but less than 1.0% by mass with respect to the entire post-chemical-mechanical-polishing cleaning composition. The pH of the cleaning composition after chemical mechanical polishing is lower than 7.0.

Description

Technical Field

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

[0002] In recent years, with the multi-layer wiring on the surface of semiconductor substrates, the so-called chemical mechanical polishing (CMP) technology is used to flatten the semiconductor substrate by physically polishing it when manufacturing devices. CMP is a method of flattening the surface of a polishing object (object to be polished) such as a semiconductor substrate using a polishing composition (slurry) containing abrasives such as silicon dioxide, aluminum oxide, and cerium oxide, an antiseptic, a surfactant, etc. The polishing object (object to be polished) is a silicon-containing material such as silicon, polysilicon, silicon oxide, and silicon nitride, wiring formed by metal, etc., plugs, etc.

[0003] A large amount of impurities (also called foreign matter or residue) remain on the surface of the semiconductor substrate after the CMP process. The impurities include abrasive grains from the polishing composition used in CMP, metals, organic substances such as preservatives and surfactants, silicon-containing materials as the polishing object, silicon-containing materials and metals generated by polishing metal wiring, plugs, etc., and organic substances such as pad scraps generated by various pads.

[0004] If the surface of the semiconductor substrate is contaminated by these impurities, the electrical properties of the semiconductor may be adversely affected, and the reliability of the device may be reduced. Therefore, it is desirable to introduce a cleaning process after the CMP process to remove these impurities from the surface of the semiconductor substrate.

[0005] As such a cleaning composition, for example, Japanese Patent Publication No. 2020-167237 discloses a rinsing composition for silicon wafers containing a water-soluble polymer that meets specific conditions, and discloses that, thereby, foreign matter on the polished silicon wafer can be removed and defects of the polished silicon wafer can be reduced. Summary of the invention

[0006] However, the technology of Japanese Patent Application Laid-Open No. 2020-167237 has a problem in that foreign matter (residue) cannot be sufficiently removed during cleaning of a polished object including a silicon-containing material.

[0007] Therefore, an object of the present invention is to provide a method for sufficiently removing residues remaining on the surface of a polished object including a silicon-containing material after polishing.

[0008] The present inventors have conducted intensive research in view of the above-mentioned problems. As a result, they have found that the above-mentioned problems can be solved by using a post-chemical mechanical polishing cleaning composition, which contains a nitrogen-containing nonionic polymer and an anionic polymer containing a sulfonic acid group, wherein the content of the nitrogen-containing nonionic polymer is more than 0.1 mass % and less than 1.0 mass % relative to the total post-chemical mechanical polishing cleaning composition, and the pH of the post-chemical mechanical polishing cleaning composition is less than 7.0, thereby completing the present invention. DETAILED DESCRIPTION

[0009] The present invention is a post-chemical mechanical polishing cleaning composition, which contains: a nitrogen-containing non-ionic polymer and an anionic polymer containing a sulfonic acid group, wherein the content of the aforementioned nitrogen-containing non-ionic polymer is greater than 0.1% by mass and less than 1.0% by mass relative to the entire post-chemical mechanical polishing cleaning composition, and the pH of the post-chemical mechanical polishing cleaning composition is less than 7.0.

[0010] In this specification, the post-chemical mechanical polishing cleaning composition having the above-mentioned structure is hereinafter 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".

[0011] By using such a chemical mechanical polishing cleaning composition (post-CMP cleaning composition) of the present invention, it is possible to fully remove residues (such as abrasive residues, especially silicon compounds, organic residues) remaining on the surface of a polished object, especially a polished object containing silicon-containing materials such as silicon nitride, silicon oxide and polycrystalline silicon.

[0012] It should be noted that, in this specification, the polished object refers to the object that has been polished with a polishing composition. In the present invention, the polished object includes a silicon-containing material. The polished object including silicon nitride means that the polished object has a film (layer) including silicon nitride, the polished object including silicon oxide means that the polished object has a film (layer) including silicon oxide, and the polished object including polysilicon means that the polished object has a film (layer) including polysilicon. That is, the polished object of the present invention has at least one selected from the group consisting of silicon-containing materials, such as silicon nitride, silicon oxide and polysilicon. In the following, the "polished object including silicon-containing material" is sometimes referred to as "polished object".

[0013] The present inventors have speculated as follows on the mechanism by which the above-mentioned configuration can remove the residue on the surface of the polished object.

[0014] 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 a sulfonic acid group are adsorbed on the surface of the polished object, thereby making it possible to remove the residue existing on the surface of the polished object. The present inventors have found that in the removal of these residues, by making the content of the nitrogen-containing nonionic polymer exceed 0.1 mass % and less than 1.0 mass % relative to the entire post-CMP cleaning composition, and making the pH of the post-CMP cleaning composition less than 7.0, the residue on the surface of the polished object can be removed more efficiently. The details of these mechanisms are unclear, but the following reasons are speculated. That is, it is believed that by forming the above-mentioned structure, the nitrogen-containing nonionic polymer and the anionic polymer containing sulfonic acid groups become easier to be more effectively adsorbed on the polishing object after grinding, thereby the residue on the surface of the polishing object after grinding is more efficiently detached, and the residue (contaminant) can be prevented from re-attaching to the surface of the polishing object after grinding.

[0015] Anionic polymers containing sulfonic acid groups are easily adsorbed on films containing silicon nitride, and the post-CMP cleaning composition of the present invention can appropriately exert the above-mentioned effect on films containing silicon nitride. In addition, sulfonic acid groups are strongly acidic groups, and therefore, they release hydrogen ions (H 2 ) even in solutions with low pH values ​​(e.g., solutions with pH values ​​of 2 to 4). + ), can maintain the ionized state (R-SO3 - Therefore, when the above-mentioned 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 is in an ionized state (R-SO3 - ), therefore, the Zeta potential of the surface of the polished object and the residue (pollutant) adsorbed with the anionic polymer containing sulfonic acid groups can be controlled to be negative. As a result, an electrostatic repulsion effect is generated between the polished object and the residue (pollutant), and the residue (pollutant) is efficiently detached from the polished object, and further, the reattachment to the polished object can be prevented. Nitrogen-containing nonionic polymers are easily adsorbed on films containing silicon oxide and / or films containing polycrystalline silicon, and the post-CMP cleaning composition of the present invention can appropriately exert the above-mentioned effects in films containing silicon oxide and / or films containing polycrystalline silicon. In addition, the nitrogen atoms of the nitrogen-containing nonionic polymers can be particularly effectively adsorbed on the film containing silicon oxide by forming hydrogen bonds with the hydroxyl groups present on the surface of the film containing silicon oxide, thereby further exerting the above-mentioned effects.

[0016] Furthermore, by forming the above-mentioned structure, the components (nitrogen-containing nonionic polymer and sulfonic acid group-containing anionic polymer) adsorbed on the surface of the polished object can also be easily detached from the surface of the polished object, and the components adsorbed on the surface of the polished object themselves are basically not left as residues or can be left in a state of being eliminated. Based on the above, it is believed that the post-CMP cleaning composition of the present invention can fully remove residues.

[0017] 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.

[0018] The following is a detailed description of the embodiments of the present invention, but the present invention is not limited to the following embodiments, and various changes can be made 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, the operation and measurement of physical properties are carried out under the conditions of room temperature (above 20°C and below 25°C) / relative humidity above 40%RH and below 50%RH.

[0019] <Residue>

[0020] In this specification, residue refers to foreign matter attached to the surface of the polishing object after polishing. Examples of residue are not particularly limited, and examples thereof include organic residues described later, particle residues derived from abrasive grains contained in the polishing composition, residues formed from components other than particle residues and organic residues, and mixtures of particle residues and organic residues.

[0021] In this specification, the organic residue refers to components consisting of organic substances such as organic low molecular weight compounds and high molecular weight compounds, organic salts, etc., among foreign substances adhering to the surface of the polishing object (surface treatment object) after polishing.

[0022] Examples of organic residues attached to the polished object include pad chips generated from a pad used in the polishing step or rinse polishing step described below, and 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.

[0023] It should be noted that the color and shape of organic residues are greatly different from other foreign matter, so whether the foreign matter is organic residue can be determined by visual observation based on SEM observation. In addition, whether the foreign matter is organic residue can also be determined by elemental analysis based on an energy dispersive X-ray analyzer (EDX) as needed. The number of organic residues can be measured using a wafer defect inspection device and SEM or EDX elemental analysis.

[0024] <Polished object>

[0025] In this specification, the polished object refers to the object that has been polished in the polishing process. The polishing process refers to the CMP process.

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

[0027] The material contained in the polishing object of the present invention is not particularly limited as long as it contains a silicon-containing material, for example, at least one selected from the group consisting of silicon nitride (Si3N4), silicon oxide (SiO2) and polycrystalline silicon (polysilicon). It may also contain carbon-containing silicon such as silicon carbonitride (SiCN), amorphous silicon, silicon materials doped with impurities, metal elements, alloys, metal nitrides, compound semiconductors such as SiGe, etc.

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

[0029] The polished object is a polished semiconductor substrate, preferably a semiconductor substrate after a CMP process. The above reason is that the residue may cause damage to the semiconductor device. Therefore, when the polished object is a polished semiconductor substrate, the semiconductor substrate cleaning process must be able to remove the residue as much as possible.

[0030] In addition, even if the polished object contains both a hydrophilic material and a hydrophobic material, the post-CMP cleaning composition of one embodiment of the present invention can reduce the residue on the surface. Here, the hydrophilic material refers to a material having a contact angle with water of less than 50°, and the hydrophobic material refers to a material having a contact angle with water of 50° or more. It should be noted that 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] As specific examples of hydrophilic materials, for example, silicon oxide, silicon nitride, silicon oxynitride, tungsten, titanium nitride, tantalum nitride, boron-containing silicon, etc. can be cited. These hydrophilic materials can be used alone, or in combination of two or more. According to a preferred embodiment of the present invention, the above-mentioned hydrophilic material is silicon nitride. According to a preferred embodiment of the present invention, the above-mentioned hydrophilic material is silicon nitride and silicon oxide. In addition, as specific examples of hydrophobic materials, for example, polysilicon, monocrystalline silicon, amorphous silicon, carbon-containing silicon, etc. can be cited. These hydrophobic materials can be used alone, or in combination of two or more. According to a preferred embodiment of the present invention, the above-mentioned hydrophobic material is polysilicon.

[0032] That is, according to a preferred embodiment of the present invention, the hydrophilic material is silicon nitride, and the hydrophobic material is polysilicon. In addition, according to a preferred embodiment of the present invention, the hydrophilic material is silicon nitride and silicon oxide, and the hydrophobic material is polysilicon.

[0033] <Chemical Mechanical Polishing Post-Cleaning Composition (CMP Post-Cleaning Composition)>

[0034] The post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) of the present invention contains: a nitrogen-containing nonionic polymer and an anionic polymer containing a sulfonic acid group. Here, in this specification, "polymer" refers to a compound with a weight average molecular weight (Mw) of 1000 or more. In addition, in this specification, "nonionic polymer" refers to a polymer that does not have anionic groups such as carboxylic acid groups, sulfonic acid groups, and phosphoric acid groups, and cationic groups such as amino groups and quaternary ammonium groups in the molecule. "Anionic polymer" refers to a polymer that has anionic groups such as carboxylic acid groups, sulfonic acid groups, and phosphoric acid groups in the molecule. Below, each polymer is described.

[0035] (Nitrogen-containing nonionic polymer)

[0036] The nitrogen-containing nonionic polymer contained in the post-CMP cleaning composition of the present invention refers to a polymer containing a nitrogen atom in the molecule among nonionic polymers.

[0037] The weight average molecular weight of the nitrogen-containing nonionic polymer is preferably 1500 or more, more preferably 3000 or more, further preferably 5000 or more, further more preferably 10000 or more, particularly preferably 25000 or more, and most preferably 35000 or more. In addition, the weight average molecular weight of the nitrogen-containing nonionic polymer is preferably 1000000 or less, more preferably 500000 or less, further preferably 300000 or less, further more preferably 100000 or less, particularly preferably 80000 or less, and most preferably 60000 or less. That is, the weight average molecular weight of the nitrogen-containing nonionic polymer is preferably 1500 or more and 1000000 or less, more preferably 3000 or more and 500000 or less, further preferably 5000 or more and 300000 or less, further more preferably 10000 or more and 100000 or less, particularly preferably 25000 or more and 80000 or less, and most preferably 35000 or more and 60000 or less. When the weight average molecular weight of the nitrogen-containing nonionic polymer is within the above range, residues on the surface of the polished object can be more efficiently removed after treatment with the post-CMP cleaning composition, thereby further demonstrating the desired effects of the present invention.

[0038] As the nitrogen-containing nonionic polymer, any nonionic polymer having nitrogen atoms may be used, for example, polyamines, polyvinyl pyrrolidone, polyacrylamide, poly-N-vinylacetamide, polydimethylacrylamide, polyacryloylmorpholine, poly-N-vinylcaprolactam, poly-N-isopropylacrylamide, polymers containing oxazoline groups, etc. can be cited. As the nitrogen-containing nonionic polymer, not only those having the main chain structure as described above can be used, but also graft copolymers having a nonionic polymer structure in the side chain can be appropriately used. As the nitrogen-containing nonionic polymer, it can be a polymer having the same (homopolymer) or different (copolymer) repeating structural units. When the nitrogen-containing nonionic polymer is a copolymer, the copolymer can be in the form of a block copolymer, a random copolymer, a graft copolymer, or an alternating copolymer.

[0039] As the nitrogen-containing nonionic polymer, a polymer having an amide bond is preferred, more preferably a polymer having an amide bond in the structure of the side chain, and further preferably at least one selected from the group consisting of polyvinyl pyrrolidone, poly-N-vinylacetamide, polydimethylacrylamide, polyvinyl caprolactam, N-isopropylacrylamide and an oxazoline-containing polymer. The nitrogen-containing nonionic polymer can be used alone or in combination of two or more. In addition, the nitrogen-containing nonionic polymer can use a commercially available product or a synthetic product.

[0040] Relative to the total mass of the post-CMP cleaning composition, the content of the nitrogen-containing nonionic polymer in the post-CMP cleaning composition exceeds 0.1 mass % and is less than 1.0 mass %, preferably 0.15 mass % or more and 0.8 mass % or less, more preferably 0.15 mass % or more and 0.45 mass % or less, and further preferably 0.15 mass % or more and 0.4 mass % or less. When the content of the nitrogen-containing nonionic polymer is less than 0.1 mass % relative to the total mass of the post-CMP cleaning composition, there is a possibility that the residue on the surface of the polished polishing object cannot be fully removed, and when it is more than 1.0 mass %, there is a possibility that the nitrogen-containing nonionic polymer itself remains as a residue on the polished polishing object. In addition, from the viewpoint of further reducing the value of the Zeta potential on the surface of the polished polishing object, it is particularly preferably 0.15 mass % or more and 0.20 mass % or less. When the post-CMP cleaning composition contains two or more nitrogen-containing nonionic polymers, the content of the nitrogen-containing nonionic polymer is set to their total amount.

[0041] (Anionic polymer containing sulfonic acid group)

[0042] The anionic polymer containing a sulfonic acid group contained in the post-CMP cleaning composition of the present invention functions as a dispersant in the post-CMP cleaning composition. By containing the anionic polymer containing a sulfonic acid group in the post-CMP cleaning composition, the zeta potential 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 simultaneously controlled to negative values ​​to form an electrostatic repulsion layer, thereby, as a result, the number of defects in the polished object can be reduced.

[0043] The weight average molecular weight of the anionic polymer containing a sulfonic acid group is preferably 1500 or more, more preferably 3000 or more, further preferably 4000 or more, further more preferably 5000 or more, particularly preferably 6000 or more, particularly preferably 7000 or more, and most preferably 8000 or more. In addition, the weight average molecular weight of the anionic polymer containing a sulfonic acid group is preferably 1000000 or less, more preferably 500000 or less, further preferably 100000 or less, further more preferably 50000 or less, particularly preferably 25000 or less, particularly more preferably 20000 or less, and most preferably 15000 or less. That is, the weight average molecular weight of the anionic polymer containing a sulfonic acid group is preferably 1500 or more and 1000000 or less, more preferably 3000 or more and 500000 or less, further preferably 4000 or more and 100000 or less, further more preferably 5000 or more and 50000 or less, particularly preferably 6000 or more and 25000 or less, particularly preferably 7000 or more and 20000 or less, and most preferably 8000 or more and 15000 or less. If the weight average molecular weight of the anionic polymer containing a sulfonic acid group is within the above range, the residue on the surface of the polished object can be removed more efficiently after the treatment with the post-CMP cleaning composition, and the desired effect of the present invention can be further exerted.

[0044] As the anionic polymer containing a sulfonic acid group, any polymer having a sulfonic acid group may be used, and specific examples thereof include polyvinylsulfonic acid, polystyrenesulfonic acid, polyallylsulfonic acid, polymethallylsulfonic acid, poly(2-acrylamide-2-methylpropanesulfonic acid), polyisoprenesulfonic acid, (meth)acrylic acid-isoprenesulfonic acid copolymer, (meth)acrylic acid-[2-(meth)acrylamide-2-methylpropanesulfonic acid] copolymer, (meth)acrylic acid-isoprenesulfonic acid-[2-(meth)acrylamide-2-methylpropanesulfonic acid] copolymer, etc. These anionic polymers containing a sulfonic acid group may be in the form of a neutralized salt.

[0045] In addition, as the anionic polymer containing sulfonic acid groups, not only those having the main chain structure as described above can be used, but also graft copolymers having an anionic polymer structure containing sulfonic acid groups in the side chain can be appropriately used. As the above-mentioned anionic polymer containing sulfonic acid groups, it can be a polymer having the same (homopolymer) or different (copolymer) repeating structural units. When the anionic polymer containing sulfonic acid groups is a copolymer, the form of the copolymer can be any of block copolymers, random copolymers, graft copolymers, and alternating copolymers. In addition, the repeating structure of the above-mentioned copolymer can be composed of a repeating structure having sulfonic acid groups and a repeating structure not having sulfonic acid groups, or it can be composed of only two or more repeating structures having sulfonic acid groups.

[0046] Furthermore, the anionic groups in the anionic polymer containing a sulfonic acid group may be only sulfonic acid groups, or may contain one or two or more kinds of anionic groups other than sulfonic acid groups in addition to the sulfonic acid groups.

[0047] 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 polymers containing sulfonic acid groups is the total amount thereof. In addition, the anionic polymer containing sulfonic acid groups may be a commercial product or a synthetic product.

[0048] The content of the anionic polymer containing a sulfonic acid group in the post-CMP cleaning composition is not particularly limited, but is preferably 0.0002 mass % to 2 mass %, more preferably 0.001 mass % to 0.2 mass %, further preferably 0.002 mass % to 0.1 mass %, particularly preferably 0.01 mass % to 0.025 mass %, and most preferably 0.015 mass % to 0.02 mass %, relative to the total mass of the post-CMP cleaning composition.

[0049] (Other polymers)

[0050] The post-CMP cleaning composition of the present invention may further contain other polymers in addition to the above-mentioned nitrogen-containing nonionic polymers and anionic polymers containing sulfonic acid groups. As other polymers, any of cationic polymers, amphoteric polymers, nonionic polymers containing no nitrogen, and anionic polymers containing no sulfonic acid groups can be used. In addition, as other polymers, water-soluble polymers are preferred. The so-called water-soluble polymers here refer to water-soluble polymers (homopolymers) having the same repeating structural units, or water-soluble polymers (copolymers) having different repeating structural units, typically compounds with a weight average molecular weight (Mw) of 1000 or more.

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

[0052] Examples of the amphoteric polymer include copolymers of a vinyl monomer having an anionic group and a vinyl monomer having a cationic group, vinyl-based amphoteric polymers having a carboxybetaine group or a sulfobetaine group, and more specifically, acrylic acid / dimethylaminoethyl methacrylate copolymers and acrylic acid / diethylaminoethyl methacrylate copolymers.

[0053] As the nonionic polymer containing no nitrogen, any nonionic polymer having no nitrogen atom is preferred, and a nonionic polymer having oxygen atoms and having no nitrogen atom is preferred. As the nonionic polymer containing no nitrogen, for example, polyvinyl alcohol, polyvinyl ethers (polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl isobutyl ether, etc.), polyalkylene oxides (polyethylene oxide, polypropylene oxide, polybutylene oxide, etc.), polyglycerol, polyethylene glycol, polypropylene glycol, polybutylene glycol, water-soluble polysaccharides such as hydroxyethyl cellulose, alginic acid polyol esters, dextrin derivatives, etc. can be cited.

[0054] In one embodiment, the content of other polymers other than the above-mentioned nitrogen-containing nonionic polymer and the anionic polymer containing sulfonic acid groups is not particularly limited, and is, for example, 0.15 mass % or less, preferably 0.10 mass % or less, more preferably less than 0.10 mass %, and further preferably 0.05 mass % or less relative to the entire post-CMP cleaning composition. In the case where the post-CMP cleaning composition contains two or more other polymers other than the above-mentioned nitrogen-containing nonionic polymer and the anionic polymer containing sulfonic acid groups, the content thereof is set to their total amount. In one embodiment, the post-CMP cleaning composition of the present invention may not contain other polymers other than the above-mentioned nitrogen-containing nonionic polymer and the anionic polymer containing sulfonic acid groups. In addition, the post-CMP cleaning composition of the present invention may contain a nonionic polymer that does not contain nitrogen, or may not contain a nonionic polymer that does not contain nitrogen, but from the viewpoint of further exerting the effect of the nitrogen-containing nonionic polymer, the post-CMP cleaning composition of the present invention preferably does not contain a nonionic polymer that does not contain nitrogen.

[0055] (Solvent)

[0056] The post-CMP cleaning composition of the present invention preferably contains a solvent. The solvent has the function of dispersing or dissolving each component. The solvent preferably contains water, and more preferably contains only water. In addition, in order to disperse or dissolve each component, the solvent can be a mixed solvent of water and an organic solvent. In this case, as the organic solvent used, for example, acetone, acetonitrile, ethanol, methanol, isopropanol, glycerol, ethylene glycol, propylene glycol, etc., which are organic solvents miscible with water, can be cited. In addition, these organic solvents can also be used without mixing with water, and after dispersing or dissolving each component, they are mixed with water. These organic solvents can be used alone or in combination of two or more.

[0057] From the viewpoint of preventing the contamination of the ground object and preventing the interference of the effects of other components, water is preferably water containing no impurities as much as possible. For example, it is preferred that the total content of transition metal ions is water below 100 mass ppb. Here, for example, the purity of water can be improved by removing impurity ions using ion exchange resins, removing foreign matter based on filters, distillation and other operations. Specifically, for example, deionized water (ion exchange water), pure water, ultrapure water, distilled water, etc. are preferably used. In this specification, the content of transition metal ions can be measured, for example, according to ICP emission spectrometry.

[0058] (Chelating Agent)

[0059] The post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) of one embodiment of the present invention preferably contains a chelating agent. By containing a chelating agent, the post-CMP cleaning composition can further promote the adsorption of nitrogen-containing non-ionic polymers on the surface of the polished object, thereby further reducing the residue. In addition, the chelating agent also has the function of adjusting the pH of the post-CMP cleaning composition. Furthermore, by forming a chelate with impurities such as metal ions, it is possible to improve the effects of nitrogen-containing non-ionic polymers and anionic polymers containing sulfonic acid groups. As a chelating agent, an organic compound having at least one phosphate group (-OP(=O)(OH)2) is preferred, and an organic compound having two or more phosphate groups (-OP(=O)(OH)2) is more preferred. That is, in one embodiment, the post-CMP cleaning composition of the present invention also contains a chelating agent having two or more phosphate groups. Specific examples of the chelating agent include orthophosphoric acid, methyl acid phosphate, ethyl acid phosphate, ethyl glycolic acid phosphate, isopropyl acid phosphate, butyl acid phosphate, 2-ethylhexyl acid phosphate, diethylenetriaminepentaacetic acid (pentetic acid), inositol hexaphosphate, edetic acid, 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP, also called etidronic acid), polyphosphoric acid, metaphosphoric acid, hexametaphosphoric acid, phosphonobutanetricarboxylic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, aminotrimethylenephosphonic acid, or salts thereof.

[0060] When the post-CMP cleaning composition contains a chelating agent, the content of the chelating agent is not particularly limited, but is preferably 0.003 mass % to 0.2 mass %, more preferably 0.005 mass % to 0.1 mass %, and further preferably 0.006 mass % to 0.06 mass %, relative to the total mass of the post-CMP cleaning composition.

[0061] (Surfactant)

[0062] The post-CMP cleaning composition of the present invention may further include a surfactant. The type of the 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 1,000.

[0063] 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; alkanolamide types such as oleic acid diethanolamide; allyl phenyl ether types such as polyoxyalkylene allyl phenyl ether, etc. In addition, propylene glycol, diethylene glycol, monoethanolamine, alcohol ethoxylate, alkylphenol ethoxylate, tertiary acetylene glycol, alkanolamide, etc. can also be used as nonionic surfactants. It should be noted that the above-mentioned nitrogen-containing nonionic polymers can function as nonionic surfactants, so it is not necessary to add a separate nonionic surfactant.

[0064] Examples of anionic surfactants include compounds other than the anionic polymers containing sulfonic acid groups, such as carboxylic acid types such as sodium myristate, sodium palmitate, sodium stearate, sodium laurate, potassium laurate, etc.; sulfate types such as sodium octyl sulfate, etc.; phosphate types such as lauryl phosphoric acid and sodium lauryl phosphate, etc.; sulfonic acid types such as dioctyl sodium sulfosuccinate and sodium dodecylbenzene sulfonate, etc. It should be noted that the anionic polymers containing sulfonic acid groups can function as anionic surfactants, and therefore, it is not necessary to add an additional anionic surfactant.

[0065] Examples of the cationic surfactant include amines such as laurylamine hydrochloride; quaternary ammonium salts such as polyethoxyamine and lauryltrimethylammonium chloride; and pyridinium salts such as laurylpyridinium chloride.

[0066] Examples of the amphoteric surfactant include lecithin, alkylamine oxides, alkyl betaines such as N-alkyl-N,N-dimethylammonium betaine, and sulfobetaine.

[0067] 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.

[0068] When the post-CMP cleaning composition contains a surfactant, the lower limit of the content of the surfactant is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more, with the total mass of the post-CMP cleaning composition being 100% by mass. In addition, the upper limit of the content of the surfactant in the post-CMP cleaning composition is preferably 5% by mass or less, and more preferably 1% by mass or less, with the total mass of the post-CMP cleaning composition being 100% by mass. It should be noted that when the post-CMP cleaning composition contains two or more surfactants, the content of the surfactant refers to their total amount.

[0069] <pH of the post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition)>

[0070] The pH of the post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) of the present invention is lower than 7.0. By making the pH of the post-CMP cleaning composition lower 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 the viewpoint of making the Zeta potential of the surface of the polished object during cleaning negative. When the pH of the post-CMP cleaning composition is 7.0 or more, the potential on the surface of the polished object becomes negative, and the anionic polymer containing a sulfonic acid group causes electrostatic repulsion with the surface of the polished object and becomes difficult to adsorb. As a result, the surface of the polished object becomes difficult to protect, and it becomes easy to cause residue (contaminants) to re-attach to the surface of the polished object, and as a result, the number of defects in the polished object increases. The pH of the post-CMP cleaning composition is preferably 2 to less than 7.0, more preferably 2 to 6, further preferably 2.3 to 5.5, further preferably 2.4 to less than 5, particularly preferably 2.4 to less than 4, and most preferably 2.4 to less than 3.

[0071] (pH adjuster)

[0072] The pH of the post-CMP cleaning composition can also be adjusted using the anionic polymer containing a sulfonic acid group and the chelating agent, but the post-CMP cleaning composition may further contain a pH adjuster.

[0073] The pH adjuster is not particularly limited, and a known pH adjuster used in the field of post-CMP cleaning compositions can be used. For example, a known acid, base, or salt thereof other than the above-mentioned chelating agent can be used. Examples of pH adjusters include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, nonanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, heptadecanoic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, eicosapentaenoic acid, lactic acid, malic acid, citric acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, cinnamic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, aconitic acid, amino acids, anthranilic acid and other carboxylic acids, sulfonic acids, organic acids such as organophosphonic 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); potassium carbonate (K2CO3); 3) , sodium carbonate (Na2CO3) and other alkali metal carbonates; hydroxides of Group 2 elements; ammonia (ammonium hydroxide); organic bases such as quaternary ammonium hydroxide compounds, etc.

[0074] The pH adjuster may be a synthetic product or a commercial product. In addition, these pH adjusters may be used alone or in combination of two or more.

[0075] The content of the pH adjuster in the post-CMP cleaning composition may be appropriately selected to achieve a desired pH value of the post-CMP cleaning composition.

[0076] In addition, the pH of the post-CMP cleaning composition adopts the value measured by the method described in the Examples.

[0077] <Other additives>

[0078] The post-CMP cleaning composition of one embodiment of the present invention may contain other additives in any proportion as needed within the range that does not hinder the effect of the present invention. However, components other than the essential components of the post-CMP cleaning composition of one embodiment of the present invention may become the cause of foreign matter (residue), so it is desired not to add them unless necessary, and even if they are added, the amount added is preferably as small as possible. As other additives, for example, antifungal agents (preservatives), dissolved gases, reducing agents, oxidants, etc. can be cited. The post-CMP cleaning composition of the present invention is acidic. In addition, the post-CMP cleaning composition of the present invention contains a polymer. Therefore, among these, the post-CMP cleaning composition of the present invention preferably contains an antifungal agent (preservative). The antifungal agent that can be used when the post-CMP cleaning composition of the present invention contains an antifungal agent is not particularly limited and can be appropriately selected according to the type of polymer. Specifically, there can be mentioned isothiazolin-based preservatives such as 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one; methyl parahydroxybenzoate and butyl parahydroxybenzoate; phenylphenols (2-phenylphenol, 3-phenylphenol and 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 (ethylhexylglycerol); capric acid, dehydroacetic acid and phenoxyethanol.

[0079] The above-mentioned antifungal agents may be used alone or in combination of two or more.

[0080] When the post-CMP cleaning composition contains a mildew preventer, the lower limit of the content (concentration) of the mildew preventer is not particularly limited, and is preferably 0.00006% by mass or more, more preferably 0.0006% by mass or more, further preferably 0.0008% by mass or more, and particularly preferably 0.001% by mass or more, relative to the total mass of the post-CMP cleaning composition. In addition, the upper limit of the content (concentration) of the mildew preventer is not particularly limited, and is preferably 3% by mass or less, more preferably 0.6% by mass or less, further preferably 0.3% by mass or less, and particularly preferably 0.06% by mass or less. That is, the content (concentration) of the mildew preventer in the post-CMP cleaning composition is preferably 0.00006% by mass or more and 3% by mass or less, more preferably 0.0006% by mass or more and 0.6% by mass or less, further preferably 0.0008% by mass or more and 0.3% by mass or less, and particularly preferably 0.001% by mass or more and 0.06% by mass or less, relative to the total mass of the post-CMP cleaning composition. If it is within this range, an effect sufficient to inactivate or destroy microorganisms is obtained. In addition, when the post-CMP cleaning composition contains two or more kinds of antifungal agents, the above content means the total amount thereof.

[0081] 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, and water, and at least one selected from the group consisting of a chelating agent, a mildew preventer, 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, and water, and at least one selected from the group consisting of a chelating agent, a mildew preventer, 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 a chelating agent, and at least one selected from the group consisting of a mildew preventer 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, a chelating agent, a mildew preventer, and an organic solvent.

[0082] In this embodiment, "the post-CMP cleaning composition substantially consists of X" means that the total content of X exceeds 99% by mass (upper limit: 100% by mass) when the total mass of the post-CMP cleaning composition is 100% by mass (relative to the post-CMP cleaning composition). Preferably, the post-CMP cleaning composition consists 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 a sulfonic acid group and water, and at least one of a chelating agent, a mildew preventer and an organic solvent" means that, with the total mass of the post-CMP cleaning composition being 100 mass % (relative to the post-CMP cleaning composition), the total content of the nitrogen-containing nonionic polymer, the anionic polymer containing a sulfonic acid group and water, and at least one of a chelating agent, a mildew preventer and an organic solvent exceeds 99 mass % (upper limit: 100 mass %), and the post-CMP cleaning composition is preferably composed of a nitrogen-containing nonionic polymer, an anionic polymer containing a sulfonic acid group and water, and at least one of a chelating agent, a mildew preventer and an organic solvent (the above total content = 100 mass %).

[0083] 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 contains substantially no abrasive particles. Here, "substantially no abrasive particles" means that the content of abrasive particles relative to the entire post-CMP cleaning composition is less than 0.1% by mass (preferably less than 0.01% by mass). That is, in one embodiment of the post-CMP cleaning composition of the present invention, the total mass of the post-CMP cleaning composition is set to 100% by mass, and the content of abrasive particles is less than 0.1% by mass.

[0084] In addition, 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" means that the content of transition metal ions relative to the entire post-CMP cleaning composition is less than 0.1 mass% (preferably less than 0.01 mass%). That is, in one embodiment of the post-CMP cleaning composition of the present invention, the total mass of the post-CMP cleaning composition is set to 100 mass%, and the content of transition metal ions is less than 0.1 mass%.

[0085] <Conductivity of Post-Chemical Mechanical Polishing Cleaning Composition (Post-CMP Cleaning Composition)>

[0086] The electrical conductivity (EC) of the post-CMP cleaning composition of the present invention is not particularly limited, and is preferably 0.45 mS / cm or more, and more preferably 0.50 mS / cm or more. In addition, the upper limit of the electrical conductivity (EC) of the post-CMP cleaning composition of the present invention is not particularly limited, and 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 of 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 anionic polymers containing sulfonic acid groups, pH adjusters, etc. It should be noted that the electrical conductivity (EC) of the post-CMP cleaning composition can be measured by the method described in the Examples.

[0087] <Water Contact Angle of Polished Object after Post-CMP Cleaning Treatment Using Post-CMP Cleaning Composition>

[0088] As described above, it is speculated that if the post-CMP cleaning composition of the present invention is used, the nitrogen-containing nonionic polymer (and the anionic polymer containing a sulfonic acid group) is adsorbed on the surface of the polished object, thereby making it possible to remove the residue existing on the surface of the polished object. Here, the small water contact angle of the surface of the polished object means that the wettability of the surface is high, and it is believed that this is because the nitrogen atoms of the nitrogen-containing nonionic polymer are partially adsorbed on the surface of the polished object, thereby improving the hydrophilicity. Therefore, it is believed that the high wettability of the surface of the polished object supports the action of the nitrogen-containing nonionic polymer as described above.

[0089] Therefore, it is preferred that the water contact angle of the polished object after the CMP cleaning process is small. As an example, when the polished object is a substrate with a film containing polysilicon (Poly-Si substrate), the water contact angle is acceptable when it is below 20°, preferably below 15°. As an example, when the polished object is a substrate with a film containing silicon oxide (such as a substrate with a TEOS film), the water contact angle is acceptable when it is below 15°, preferably below 10°. As an example, when the polished object is a substrate with a film containing silicon nitride (Si3N4 substrate), the water contact angle is acceptable when it is below 17°, preferably below 13°. It should be noted that the water contact angle of the polished object can be measured by the method described in the embodiments.

[0090] <Zeta Potential of Polished Object after Post-CMP Cleaning Treatment Using Post-CMP Cleaning Composition>

[0091] As described above, the post-CMP cleaning composition of the present invention contains an anionic polymer containing a sulfonic acid group, and therefore, the Zeta potential of the surface of the polished object and the surface of the residue (contaminant) can be controlled to be negative at the same time. It is inferred that the residue (contaminant) is efficiently separated from the polished object by electrostatic repulsion, thereby suppressing reattachment to the polished object.

[0092] Therefore, the Zeta potential of the surface of the polished object after the CMP cleaning process is preferably a negative value. As an example, when the polished object is a substrate having a film containing polysilicon (Poly-Si substrate), the above-mentioned Zeta potential is acceptable when it is below -5mV, preferably below -5mV. As an example, when the polished object is a substrate having a film containing silicon oxide (such as a substrate having a TEOS film), the above-mentioned Zeta potential is acceptable when it is below -5mV, preferably below -10mV. As an example, when the polished object is a substrate having a film containing silicon nitride (Si3N4 substrate), the above-mentioned Zeta potential is acceptable when it is below -5mV, preferably below -15mV. It should be noted that the Zeta potential of the surface of the polished object after the CMP cleaning process can be estimated according to the method described in the embodiment.

[0093] <Method for producing a post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition)>

[0094] 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 required. The temperature when the components are mixed is not particularly limited, but is preferably 10° C. or higher and 40° C. or lower. In order to increase the dissolution rate, heating may be performed. In addition, the mixing time is not particularly limited.

[0095] <Chemical Mechanical Polishing Post-Cleaning Method (CMP Post-Cleaning Method; Surface Treatment Method)>

[0096] Another embodiment of the present invention is a post-chemical mechanical polishing cleaning method (also referred to as "post-CMP cleaning method" or "surface treatment method" in this specification), which comprises the following steps: using the above-mentioned post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) to perform a post-chemical mechanical polishing cleaning treatment (also referred to as "post-CMP cleaning treatment" or "surface treatment" in this specification) on the polished polishing object. In this specification, the post-chemical mechanical polishing cleaning method (post-CMP cleaning method) refers to a method for reducing residues on the surface of the polished polishing object, which is a method for performing cleaning in a broad sense.

[0097] According to one aspect of the present invention, the post-CMP cleaning method can fully remove the residue remaining on the surface of the polished object. That is, according to another aspect of the present invention, a method for reducing the residue on the surface of the polished object is provided, which uses the above-mentioned post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) to perform a post-chemical mechanical polishing cleaning treatment (post-CMP cleaning treatment) on the polished object. In addition, according to another aspect of the present invention, a post-chemical mechanical polishing cleaning method (post-CMP cleaning method) is also provided, which uses the above-mentioned post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) to perform a post-chemical mechanical polishing cleaning treatment (post-CMP cleaning treatment) on the polished object containing silicon-containing material, thereby reducing the residue on the surface of the polished object.

[0098] The post-CMP cleaning method according to one embodiment of the present invention is performed by bringing the post-CMP cleaning composition of the present invention into direct contact with a polished object.

[0099] As the post-chemical mechanical polishing cleaning treatment method (post-CMP cleaning treatment method), there can be mainly cited (I) a method based on a rinse polishing treatment and (II) a method based on 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, padding, etc.) on the surface of the polished object and obtain a clean surface. The above (I) and (II) are explained below.

[0100] (I) Rinsing and grinding

[0101] The post-CMP cleaning composition of the present invention is suitable for rinsing and polishing treatment. That is, the post-CMP cleaning composition of one embodiment of the present invention can preferably be used as a rinsing and polishing composition. The rinsing and polishing treatment is performed as follows: After the final grinding (finishing grinding) of the polishing object, it is performed on a grinding plate (platen) equipped with a grinding pad for the purpose of removing foreign matter on the surface of the polishing object. At this time, the post-CMP cleaning composition of the present invention is directly contacted with the polished polishing object, thereby performing a rinsing and polishing treatment. As a result, foreign matter on the surface of the polished polishing object is removed by the friction force (physical action) based on the polishing pad and the chemical action based on the post-CMP cleaning composition. Among foreign matter, especially particles and organic residues are easily removed by physical action. Therefore, in the rinsing and polishing treatment, friction with the polishing pad is utilized on the grinding plate (platen), so that particles and organic residues can be effectively removed.

[0102] That is, in this specification, the rinse polishing treatment, the rinse polishing method, and the rinse polishing step refer to treatment, method, and step for reducing residue on the surface of an object to be cleaned after CMP, respectively, using a polishing pad.

[0103] Specifically, the rinse polishing treatment can be performed as follows: the surface of the polished object after the polishing step is placed on a polishing plate of a polishing device, the polishing pad is brought into contact with the polished semiconductor substrate, and a post-CMP cleaning composition is supplied to the contact portion while the polished object and the polishing pad are made to slide relative to each other.

[0104] As the polishing device, a general polishing device that is equipped with a holder for holding the object to be polished, a motor capable of changing the rotation speed, etc., and has a polishing plate to which a polishing pad (polishing cloth) can be attached can be used.

[0105] The rinsing and polishing treatment can be performed using any of a single-sided polishing device and a double-sided polishing device. In addition, the above-mentioned polishing device preferably also has a discharge nozzle for the post-CMP cleaning composition in addition to the discharge nozzle for the polishing composition. The operating conditions during the rinsing and polishing treatment of the polishing device are not particularly limited, and can be appropriately set by those skilled in the art.

[0106] As the polishing pad, general nonwoven fabric, polyurethane, porous fluororesin, etc. can be used without particular limitation. The polishing pad is preferably provided with groove processing for allowing the post-CMP cleaning composition to accumulate.

[0107] There is no particular restriction on the washing and grinding conditions. For example, the rotation speed of the grinding plate and the rotation speed of the grinding head (carrier) are preferably 10 rpm (0.17 s -1 ) and above 100rpm(1.67s -1 ), and the pressure (grinding pressure) applied to the polished polishing object is preferably 0.5psi (3.4kPa) or more and 10psi (68.9kPa) or less. The method of supplying the post-CMP cleaning composition to the polishing pad is also not particularly limited, for example, a method of continuously supplying with a pump or the like (sagging). There is no limit to the supply amount, but it is preferred that the surface of the polishing pad is always covered with the post-CMP cleaning composition, preferably 10mL / minute or more and 5000mL / minute or less. The rinsing and polishing time is also not particularly limited, preferably 5 seconds or more and 180 seconds or less.

[0108] After the rinse polishing treatment using the post-CMP cleaning composition of one embodiment of the present invention, the polished object (post-CMP cleaning object) is preferably pulled out while applying the post-CMP cleaning composition of one embodiment of the present invention.

[0109] (II) Cleaning

[0110] The post-CMP cleaning composition of the present invention can also be used for cleaning treatment. That is, the post-CMP cleaning composition of one embodiment of the present invention can be preferably used as a cleaning composition. The cleaning treatment is preferably: after the final grinding (finishing grinding) of the grinding object, after the above-mentioned rinse grinding treatment, or after other rinse grinding treatments using a rinse grinding composition other than the post-CMP cleaning composition of the present invention, for the purpose of removing foreign matter on the surface of the ground grinding object (cleaning object). It should be noted that the cleaning treatment and the above-mentioned rinse grinding treatment are classified according to the parts where these treatments are performed. The cleaning treatment is a surface treatment performed on a part that is not on the grinding plate (platen), and is preferably a surface treatment performed after the ground grinding object is removed from the grinding plate (platen). In the cleaning treatment, the post-CMP cleaning composition of the present invention can also be directly contacted with the ground grinding object to remove foreign matter on the surface of the object.

[0111] As an example of a method for performing a cleaning treatment, the following methods can be cited: method (i), in which a cleaning brush is brought into contact with one or both surfaces of the polished object while the polished object is held, and the surface of the polished object is wiped with the cleaning brush while supplying a post-CMP cleaning composition to the contact portion; method (ii) (immersion method), in which the polished object is immersed in a post-CMP cleaning composition and subjected to ultrasonic treatment and stirring. In the above methods, foreign matter on the surface of the polished object is removed by the friction force of the cleaning brush or the mechanical force generated by ultrasonic treatment and stirring, and the chemical action of the post-CMP cleaning combination.

[0112] In the above method (i), the method for contacting the polished object with the post-CMP cleaning composition is not particularly limited, and examples include: a rotating method in which the polished object is rotated at high speed while the post-CMP cleaning composition is flowed onto the polished object from a nozzle; a spraying method in which the post-CMP cleaning composition is sprayed onto the polished object and cleaned; etc.

[0113] From the viewpoint of being able to more efficiently remove contamination in a short time, the cleaning treatment is preferably performed by a rotary method and / or a spray method, and more preferably by a rotary method.

[0114] As an apparatus for performing such a cleaning process, there are: a batch cleaning apparatus that simultaneously performs a post-CMP cleaning process on a plurality of polished objects stored in a box; a single-wafer cleaning apparatus that mounts a single polished object on a holder and performs a post-CMP cleaning process, etc. From the viewpoint of shortening the cleaning time, etc., it is preferable to use a single-wafer cleaning apparatus.

[0115] Furthermore, as a device for performing a cleaning process, there can be cited a grinding device having a cleaning device for wiping the ground object with a cleaning brush after removing the ground object from a grinding plate. By using such a grinding device, the cleaning process of the ground object can be performed more efficiently.

[0116] As such a grinding device, a general grinding device having a holder for holding the ground object, a motor capable of changing the rotation speed, a cleaning brush, etc. can be used. As the grinding device, any of a single-sided grinding device or a double-sided grinding device can be used. It should be noted that, after the CMP process, when the rinsing and grinding process is performed, it is more efficient and preferred to perform the cleaning process using the same device as the grinding device used in the rinsing and grinding process.

[0117] The cleaning brush is not particularly limited, but is preferably a brush made of resin. The material of the resin brush is not particularly limited, but is preferably PVA (polyvinyl alcohol). The cleaning brush is more preferably a sponge made of PVA.

[0118] There is no particular restriction on the cleaning conditions, and they can be appropriately set according to the type of the object to be polished and the type and amount of the residue to be removed. For example, the preferred speed of the cleaning brush is 10 rpm (0.17 s -1 ) and above 200rpm(3.33s -1 ) or less, the rotation speed of the polished object after polishing is 10rpm (0.17s -1 ) and above 100rpm(1.67s -1 ) or less. The pressure (polishing pressure) applied to the polished polishing object is preferably 0.5psi (3.4kPa) or more and 10psi (68.9kPa) or less. There is no particular restriction on the method of supplying the post-CMP cleaning composition to the cleaning brush. For example, a method of continuously supplying with a pump or the like (drooping) is adopted. There is no restriction on the supply amount, but it is preferred that the surface of the cleaning brush and the polished polishing object is always covered with the post-CMP cleaning composition, preferably 10mL / minute or more and 5000mL / minute or less. There is no particular restriction on the cleaning time. For the process of using the post-CMP cleaning composition of one embodiment of the present invention, it is preferably 5 seconds or more and 180 seconds or less. If it is within this range, foreign matter can be removed more effectively.

[0119] The temperature of the post-CMP cleaning composition during cleaning is not particularly limited and may be generally room temperature, but may be heated to about 40° C. or higher and 70° C. or lower within a range that does not impair the performance.

[0120] In the above method (ii), the conditions of the cleaning method by immersion are not particularly limited, and a known method can be used.

[0121] Before performing the post-CMP cleaning treatment by the above method (I) or (II), cleaning with water may be performed.

[0122] (Post-cleaning treatment)

[0123] In addition, as a post-CMP cleaning treatment method, it is preferred that after the post-CMP cleaning treatment of (I) or (II) using the post-CMP cleaning composition of one embodiment of the present invention, the polished polishing object is further cleaned. In this specification, the cleaning treatment is referred to as post-cleaning treatment. There is no particular limitation on the post-cleaning treatment, and examples thereof include: a method of simply flowing water on the polished polishing object; a method of simply immersing the polished polishing object in water; etc. In addition, similarly to the post-CMP cleaning treatment based on the method (II) described above, examples include: a method in which a cleaning brush is brought into contact with one or both sides of the polished object while the polished object is held, and the surface of the polished object is wiped with the cleaning brush while water or an aqueous solution (e.g., an NH3 aqueous solution) is supplied to the contact portion, or water and an aqueous solution (e.g., an NH3 aqueous solution) are supplied in any order (supplying water followed by supplying the aqueous solution or supplying the aqueous solution followed by supplying water) (brush cleaning); a method in which the polished object is immersed in water and subjected to ultrasonic treatment and stirring (immersion method); etc. Among these, the following method is preferred: a method in which a cleaning brush is brought into contact with one or both sides of the polished object while the polished object is held, and the surface of the polished object is wiped with the cleaning brush while water or an aqueous solution (e.g., an NH3 aqueous solution) is supplied to the contact portion, or water and an aqueous solution (e.g., an NH3 aqueous solution) are supplied in any order (supplying water followed by supplying the aqueous solution or supplying the aqueous solution followed by supplying water) is supplied to the contact portion. It should be noted that the apparatus and conditions for the post-cleaning treatment can refer to the description of the treatment (II) described above. Here, as the water used in the post-cleaning treatment, deionized water is particularly preferably used.

[0124] By performing post-CMP cleaning treatment using the post-CMP cleaning composition of one embodiment of the present invention, the residue is easily removed. Therefore, after performing post-CMP cleaning treatment using the post-CMP cleaning composition of one embodiment of the present invention, further cleaning treatment with water is performed, thereby removing the residue extremely well.

[0125] In addition, the polished object after the CMP post-cleaning treatment or the post-cleaning is preferably dusted off with water droplets attached to the surface and dried using a rotary dryer etc. In addition, the surface of the polished object after the CMP post-cleaning treatment or the post-cleaning can be dried by air supply drying.

[0126] <Method for Manufacturing Semiconductor Substrate>

[0127] The post-CMP cleaning method of one embodiment of the present invention is preferably used in the case where the polished object is a polished semiconductor substrate. That is, according to another embodiment of the present invention, a method for manufacturing a semiconductor substrate is also provided, wherein the polished object is a polished semiconductor substrate, and the manufacturing method includes the following steps: for the polished semiconductor substrate, the residue on the surface of the polished semiconductor substrate is reduced by the above-mentioned post-CMP cleaning method. Thus, according to the present invention, a method for manufacturing a semiconductor substrate is provided, wherein the polished object is a polished semiconductor substrate, and the manufacturing method includes the following steps: a polishing step, using a polishing composition containing abrasives, polishing a pre-polished semiconductor substrate containing a silicon-containing material such as at least one selected from the group consisting of silicon oxide, polycrystalline silicon and silicon nitride, thereby obtaining a polished semiconductor substrate; and, a post-chemical mechanical polishing cleaning step (also referred to as "post-CMP cleaning step" or "surface treatment step" in this specification), using the above-mentioned post-chemical mechanical polishing cleaning composition (post-CMP cleaning composition) to reduce the residue containing abrasives on the surface of the polished semiconductor substrate.

[0128] The details of the semiconductor substrate to which the above-mentioned manufacturing method is applied are as described in the description of the polished object subjected to the post-CMP cleaning treatment using the above-mentioned post-CMP cleaning composition.

[0129] In addition, the manufacturing method of the semiconductor substrate is not particularly limited as long as it includes a post-CMP cleaning treatment process in which the post-CMP cleaning composition of one embodiment of the present invention is used on the surface of the ground semiconductor substrate. As the above-mentioned manufacturing method, for example, a method having a grinding process and a cleaning process for forming a ground semiconductor substrate can be cited. In addition, as another example, a method having a rinsing grinding process between the grinding process and the cleaning process can be cited in addition to the grinding process and the cleaning process. Below, these various processes are described.

[0130] [Polishing process]

[0131] The polishing step that may be included in the method for manufacturing a semiconductor substrate is a step of polishing the semiconductor substrate to form a polished semiconductor substrate.

[0132] The polishing process is not particularly limited as long as it is a process for polishing a semiconductor substrate, and is a chemical mechanical polishing (CMP) process. In addition, the polishing process may be a polishing process formed by a single process, or may be a polishing process formed by a plurality of processes. As a polishing process formed by a plurality of processes, for example, there can be cited: a process of performing a finishing polishing process after a pre-polishing process (rough polishing process); a process of performing a second polishing process once or twice or more after a first polishing process, and then performing a finishing polishing process, etc. The post-CMP cleaning treatment process using the post-CMP cleaning composition of the present invention is preferably performed after the above-mentioned finishing polishing process.

[0133] As the grinding composition, known grinding compositions can be suitably used according to the characteristics of the semiconductor substrate. As the grinding composition, there is no particular restriction, for example, a grinding composition comprising abrasive grains, a solvent, a water-soluble polymer and a pH adjusting agent etc. can be preferably used. As a specific example of the above-mentioned grinding composition, a grinding composition comprising silicon oxide (e.g., colloidal silicon dioxide), polyvinyl pyrrolidone, ammonia and water etc. can be cited.

[0134] The abrasive grains may be any of inorganic grains, organic grains, and organic-inorganic composite grains. Specific examples of inorganic grains include, for example, grains formed of metal oxides such as silicon oxide, aluminum oxide, cerium oxide, and titanium dioxide, silicon nitride grains, silicon carbide grains, and boron nitride grains. Specific examples of organic grains include, for example, polymethyl methacrylate (PMMA) grains. In addition, the abrasive grains may be commercially available or synthetic. Furthermore, the abrasive grains may be surface-modified. The abrasive grains may be used alone or in combination of two or more.

[0135] The lower limit of the average primary particle size of the abrasive is preferably more than 10nm, more preferably more than 15nm, further preferably more than 20nm, and further preferably more than 30nm. If it is such a range, a high grinding speed can be maintained, and therefore, it can be suitable for a rough grinding process. In addition, the upper limit of the average primary particle size of the abrasive is preferably less than 200nm, more preferably less than 150nm, and further preferably less than 100nm. In some schemes, the average primary particle size can be less than 75nm, less than 60nm, or less than 50nm. If it is such a range, defects on the surface of the grinding object after grinding can be further suppressed. It should be noted that the average primary particle size of the abrasive is calculated, for example, based on the specific surface area of ​​the abrasive measured by the BET method.

[0136] The lower limit of the average secondary particle size of the abrasive is preferably 15 nm or more, more preferably 30 nm or more, further preferably 40 nm or more, further more preferably 50 nm or more, and particularly preferably 60 nm or more. If it is such a range, a high grinding speed can be maintained. In addition, the upper limit of the average secondary particle size of the abrasive is preferably 300 nm or less, more preferably 200 nm or less, further preferably 150 nm or less, further more preferably 100 nm or less, and particularly preferably 80 nm or less. If it is such a range, the surface defects of the grinding object after grinding can be further suppressed. The average secondary particle size of the abrasive can be measured by a dynamic light scattering method. For example, the model "FPAR-1000" made by Otsuka Electronics Co., Ltd. or its equivalent can be used for measurement.

[0137] When the grinding composition is directly used as a polishing liquid, the content of abrasive particles is preferably 0.1% by mass or more, more preferably 0.4% by mass or more, and further preferably 1.0% by mass or more relative to the grinding composition. The grinding speed is improved due to the increase in the content of abrasive particles. In addition, when the grinding composition is directly used as a polishing liquid, from the viewpoint of preventing scratches, the content of abrasive particles is usually appropriate to be 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 2% by mass or less. From the viewpoint of economy, it is also preferred to reduce the content of abrasive particles. It should be noted that when two or more abrasive particles are used in combination, the above content refers to the total content of two or more abrasive particles.

[0138] The pH adjuster and the solvent are the same as those defined in the above-mentioned sections (pH adjuster) and (solvent), respectively, and therefore, description thereof is omitted here.

[0139] As a grinding device, a general grinding device having a grinding plate to which a grinding pad (grinding cloth) can be adhered can be used, which is equipped with a retainer for holding the grinding object and a motor that can change the rotation speed, etc. As a grinding device, any one of a single-sided grinding device or a double-sided grinding device can be used.

[0140] As the polishing pad, general nonwoven fabric, polyurethane, porous fluororesin, etc. can be used without particular limitation. The polishing pad is preferably provided with grooves for storing the polishing liquid.

[0141] There is no particular restriction on the grinding conditions. For example, the rotation speed of the grinding plate and the rotation speed of the grinding head (carrier) are preferably 10 rpm (0.17 s -1 ) and above 100rpm(1.67s -1), the pressure (grinding pressure) applied to the polishing object is preferably 0.5psi (3.4kPa) or more and 10psi (68.9kPa) or less. The method of supplying the polishing composition to the polishing pad is also not particularly limited, for example, a method (sagging) of continuously supplying with a pump or the like is adopted. There is no limit to its supply amount, but it is preferred that the surface of the polishing pad is always covered with the polishing composition, preferably 10mL / minute or more and 5000mL / minute or less. The grinding time is also not particularly limited, and for the process using the polishing composition, it is preferably 5 seconds or more and 180 seconds or less.

[0142] [Post-Chemical Mechanical Polishing Cleaning Process (Post-CMP Cleaning Process)]

[0143] The post-CMP cleaning treatment step is a step of reducing the residue on the surface of the polished object using the post-CMP cleaning composition of the present invention. In the method for manufacturing a semiconductor substrate, a cleaning step as a post-CMP cleaning treatment step may be performed after the rinse polishing step, or only the rinse polishing step or only the cleaning step may be performed.

[0144] (Rinsing and grinding process)

[0145] The rinse polishing step can be provided between the polishing step and the cleaning step in the method for manufacturing a semiconductor substrate. The rinse polishing step is a step for reducing foreign matter on the surface of a polished object (polished semiconductor substrate) by a post-CMP cleaning treatment method (rinsing polishing treatment method) of one embodiment of the present invention.

[0146] The details of the rinsing and polishing method used in the rinsing and polishing step are as described in the description of the above rinsing and polishing process.

[0147] (Cleaning process)

[0148] The cleaning step can be provided after the polishing step or after the rinse polishing step in the method for manufacturing a semiconductor substrate. The cleaning step is a step for reducing foreign matter on the surface of a polished object (polished semiconductor substrate) by using a post-CMP cleaning treatment method (cleaning method) of one embodiment of the present invention.

[0149] The details of the cleaning method used in the cleaning step are as described in the description of the above cleaning method.

[0150] The embodiments of the present invention have been described in detail, but they are illustrative and exemplary rather than limiting, indicating that the protection scope of the present invention should be interpreted by the appended claims.

[0151] The present invention includes the following aspects and methods.

[0152] 1. A post-chemical mechanical polishing cleaning composition, comprising: a nitrogen-containing nonionic polymer and an anionic polymer containing a sulfonic acid group, wherein the content of the nitrogen-containing nonionic polymer is more than 0.1 mass % and less than 1.0 mass % relative to the total post-chemical mechanical polishing cleaning composition, and the pH of the post-chemical mechanical polishing cleaning composition is less than 7.0;

[0153] 2. The post-CMP cleaning composition according to 1. above, wherein the nitrogen-containing nonionic polymer has an amide bond;

[0154] 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;

[0155] 4. The post-CMP 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 polyvinyl pyrrolidone, poly-N-vinylacetamide, polydimethylacrylamide, polyvinyl caprolactam, N-isopropylacrylamide and an oxazoline group-containing polymer;

[0156] 5. The post-CMP cleaning composition according to any one of 1. to 4. above, further comprising a chelating agent having two or more phosphate groups;

[0157] 6. The chemical mechanical polishing cleaning composition according to any one of 1. to 5. above, which does not substantially contain abrasive particles;

[0158] 7. A post-chemical mechanical polishing cleaning method, wherein the post-chemical mechanical polishing cleaning composition according to any one of 1. to 6. is used to perform surface treatment on a polished object comprising at least one selected from the group consisting of silicon oxide, polysilicon and silicon nitride, so as to reduce residues on the surface of the polished object;

[0159] 8. The post-CMP cleaning method according to 7. above, which is a rinse polishing method or a cleaning method;

[0160] 9. A method for manufacturing a semiconductor substrate, wherein the polished object is a polished semiconductor substrate, the method comprising the following steps:

[0161] a polishing step of polishing a pre-polished semiconductor substrate comprising at least one selected from the group consisting of silicon oxide, polycrystalline silicon and silicon nitride using a polishing composition comprising abrasive grains to obtain a polished semiconductor substrate; and

[0162] The post-chemical mechanical polishing cleaning step uses the post-chemical mechanical polishing cleaning composition described in any one of 1. to 6. above to reduce the residues including the abrasive grains on the surface of the polished semiconductor substrate.

[0163] Example

[0164] The present invention is further described in detail with the following examples and comparative examples. However, the technical scope of the present invention should not be limited to the following examples. It should be noted that, unless otherwise specified, "%" and "parts" refer to "mass %" and "mass parts", respectively. In addition, in the following examples, unless otherwise specified, the operation is carried out under the conditions of room temperature (25°C) / relative humidity of 40%RH or more and 50%RH or less.

[0165] [Preparation of polymer]

[0166] The following nitrogen-containing nonionic polymer and sulfonic acid group-containing anionic polymer were prepared.

[0167] "Nitrogen-containing nonionic polymer"

[0168] Polyvinyl pyrrolidone (DKS Co. Ltd., product name PITZCOL (registered trademark) K30A); weight average molecular weight 45000

[0169] "Anionic polymer containing sulfonic acid group"

[0170] Sodium salt of a copolymer of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid (hereinafter, "(acrylic acid / sulfonic acid) copolymer") (product name: ARON A-6012 (TOAGOSEI CO., LTD.)); weight average molecular weight 12,000

[0171] The weight average molecular weight of the above polymer is measured by the following method.

[0172] [Measurement of weight average molecular weight (Mw) of polymer]

[0173] The weight average molecular weight (Mw) of the polymer is a value of the weight average molecular weight (polyethylene glycol equivalent) measured by gel permeation chromatography (GPC).

[0174] GPC device: manufactured by Shimadzu Corporation

[0175] Model: Prominence+ELSD detector (ELSD-LTII)

[0176] Column: VP-ODS (manufactured by Shimadzu Corporation)

[0177] Mobile phase A: MeOH

[0178] B: 1% acetic acid aqueous solution

[0179] Flow rate: 1mL / min

[0180] Detector: ELSD temp.40℃、Gain 8、N2GAS 350kPa

[0181] Column oven temperature: 40°C

[0182] Injection volume: 40μL.

[0183] [Measurement of pH of Post-CMP Cleaning Composition]

[0184] The pH of the post-CMP cleaning composition (liquid temperature: 25° C.) was confirmed using a pH meter (HORIBA, Ltd., product name: LAQUA (registered trademark)).

[0185] [Electrical conductivity of post-CMP cleaning composition]

[0186] The electrical conductivity (EC) of the post-CMP cleaning composition was measured using a table-top conductivity meter (manufactured by HORIBA, Ltd., model: DS-71LAQUA (registered trademark)).

[0187] [Preparation of post-CMP cleaning composition]

[0188] (Example 1)

[0189] At 25° C., polyvinyl pyrrolidone 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 a sulfonic acid group; water (deionized water) as a solvent; 1-hydroxyethane-1,1-diphosphonic acid (hereinafter “HEDP”) (product name: Dequest (registered trademark) 2010EL (Italmatch Japan Ltd.)) as a chelating agent; ammonia (product name: EL ammonia water (KANTO CHEMICAL CO., INC.)) as a pH adjuster; and a mildew preventer (preservative) (San-Ai-Bac R-30 (manufactured by SAN-AIO BBLICO., LTD.)) were stirred and mixed for 5 minutes to prepare a post-CMP cleaning composition A1.

[0190] Here, the content of nitrogen-containing nonionic polymer in the post-CMP cleaning composition is 0.15 mass% relative to the total mass of the post-CMP cleaning composition A1; the content of anionic polymer containing sulfonic acid group is 0.02 mass% relative to the total mass of the post-CMP cleaning composition A1; the content of chelating agent is 0.024 mass% relative to the total mass of the post-CMP cleaning composition A1; the content of pH adjuster is an amount that makes the pH of the post-CMP cleaning composition A1 become 2.8; the content of mildew inhibitor is 0.0012 mass% relative to the total mass of the post-CMP cleaning composition A1.

[0191] (Examples 2 to 11, Comparative Examples 1 to 5)

[0192] 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 described in Table 1 below.

[0193] In Table 1, the nitrogen-containing nonionic polymer is referred to as "N-containing nonionic polymer", and the (acrylic acid / sulfonic acid) copolymer is referred to as "AA / SA copolymer".

[0194] In Table 1, "PVP" means polyvinyl pyrrolidone, and "PVA" means polyvinyl alcohol. In Table 1, "-" (hyphen) means that the compound was not added.

[0195] [Table 1]

[0196]

[0197] [Preparation of the polished object]

[0198] A polished object to be polished is prepared after being polished by the chemical mechanical polishing (CMP) step described below.

[0199] (CMP process)

[0200] As a polishing object, (1) a surface having a thickness of A silicon wafer (also referred to as a Poly-Si substrate or a polycrystalline silicon substrate in this specification) (300 mm, blank wafer, manufactured by D&X CO., LTD.) having a polycrystalline silicon film of thickness 100 mm or more; (2) a silicon wafer having a polycrystalline silicon film of thickness 100 mm or more formed on the surface; A silicon wafer (also referred to as a TEOS substrate) having a TEOS film (300 mm, blank wafer, manufactured by ADVANTECH CO., LTD.); and, (3) a silicon wafer having a thickness of Silicon wafer (also referred to as Si3N4 substrate) with a silicon nitride (Si3N4) film (300 mm, blank wafer, manufactured by ADVANTECH CO., LTD.). It should be noted that

[0201] The Poly-Si substrate, TEOS substrate and Si3N4 substrate prepared above were ground using a grinding composition (composition: a slurry containing 10% by mass of colloidal silica (average primary particle size 35nm, average secondary particle size 70nm), 0.25% by mass of polyvinyl pyrrolidone (manufactured by DKS Co. Ltd., PITZCOL (registered trademark) K-30A and 0.33% by mass of ammonia (ammonium hydroxide) diluted 5 times) and ground under the following conditions. It should be noted that 1rpm = 0.017s -1 .

[0202] <Grinding device and grinding conditions>

[0203] Grinding device: FREX300E manufactured by EBARA CORPORATION

[0204] Polishing pad: FUJIBO HOLDINGS, INC. foamed polyurethane pad H800

[0205] Dresser: Nylon brush (manufactured by 3M Company)

[0206] Grinding pressure: 2.0 psi (1 psi = 6894.76 Pa, the same below)

[0207] Grinding plate speed: 80rpm

[0208] Grinding head speed: 80rpm

[0209] Supply of polishing composition: Sagging

[0210] Polishing composition supply amount: 200 mL / min

[0211] Grinding time: 30 seconds.

[0212] [Post-CMP Cleaning Treatment]

[0213] (Rinsing and grinding)

[0214] After the surface of the object to be polished is polished by the above CMP process, the polished object is removed from the polishing platen. Then, in the same polishing device, the polished object is mounted on another polishing platen, and the polished surface of the object to be polished is rinsed and polished using the post-CMP cleaning compositions A1 to A11 and B1 to B5 prepared in Examples 1 to 11 and Comparative Examples 1 to 5 under the following conditions.

[0215] <Rinsing and grinding apparatus and rinsing and grinding conditions>

[0216] Grinding pressure: 1.0psi

[0217] Plate speed: 80rpm

[0218] Grinding head speed: 80rpm

[0219] Supply of post-CMP cleaning composition: Sagging

[0220] Post-CMP cleaning composition supply amount: 300 mL / min

[0221] Grinding time: 60 seconds.

[0222] (After cleaning)

[0223] After the rinse polishing treatment, the substrate surface was brush-cleaned for 20 seconds using a 0.3 mass % NH 3 aqueous solution, and then cleaned with deionized water for 40 seconds, thereby obtaining a polished object after rinse polishing.

[0224] [Evaluation 1: Determination of the number of residues]

[0225] The number of residues on the surfaces of the TEOS substrate, Poly-Si substrate and Si3N4 substrate, which were subjected to a cleaning treatment based on the method described in the above-mentioned item [Chemical Mechanical Polishing Post-Cleaning Treatment (CMP Post-Cleaning Treatment)] for the polished polished object obtained in the above-mentioned item [Preparation of Polished Polished Object], was evaluated. Specifically, using an optical inspection machine Surfscan (registered trademark) SP5 manufactured by KLA Corporation, the number of residues with a diameter exceeding 40 nm was counted for the TEOS substrate and Si3N4 substrate, and the number of residues with a diameter exceeding 70 nm was counted for the Poly-Si substrate, with respect to the remaining portion excluding a portion with a width of 5 mm from the outer peripheral end (a portion from 0 mm to 5 mm when the outer peripheral end is set to 0 mm). Afterwards, the number of abrasive residues and the number of organic residues on the above-mentioned polished TEOS substrate, Poly-Si substrate and Si3N4 substrate were measured by SEM observation using ReviewSEM RS6000 manufactured by Hitachi High-Technologies Corporation. First, under SEM observation, 100 samples of the residues present in the remaining portion of the polished TEOS substrate, Poly-Si substrate and Si3N4 substrate, excluding the portion with a width of 5 mm from the outer peripheral end, were sampled. Next, from the 100 sampled residues, the type of residue (abrasive or organic residue) was determined under visual SEM observation, and the number of abrasive residues (SiO2 residues) and organic residues (pads, polymers, etc.) was confirmed. The results are shown in Table 2 below.

[0226] The number of abrasive residues (SiO2 residues) is preferably as small as possible. As an example, the number of abrasive residues with a diameter of 70 nm or more on a Poly-Si substrate is acceptable when it is 25 or less, preferably 20 or less, more preferably 15 or less, further preferably 10 or less, and particularly preferably 9 or less. As an example, the number of abrasive residues with a diameter of 40 nm or more on a TEOS substrate is acceptable when it is 300 or less, preferably 250 or less. As an example, the number of abrasive residues with a diameter of 40 nm or more on a Si3N4 substrate is acceptable when it is 300 or less, preferably 250 or less.

[0227] In addition, the number of organic residues (pads, polymers, etc.) is preferably as small as possible. As an example, the number of organic residues (pads, polymers, etc.) with a diameter of 70 nm or more on a Poly-Si substrate is acceptable when it is 150 or less, preferably 100 or less, and more preferably 90 or less. As an example, the number of organic residues (pads, polymers, etc.) with a diameter of 40 nm or more on a TEOS substrate is acceptable when it is 200 or less, preferably 150 or less, and more preferably 130 or less. As an example, the number of organic residues (pads, polymers, etc.) with a diameter of 40 nm or more on a Si3N4 substrate is acceptable when it is 50 or less, and preferably 30 or less.

[0228] [Evaluation 2: Measurement of water contact angle (wettability)]

[0229] The water contact angles of the Poly-Si substrates, TEOS substrates and Si3N4 substrates subjected to rinse polishing treatment using the post-CMP cleaning compositions A1 to A11 and B1 to 4 prepared in Examples 1 to 11 and Comparative Examples 1 to 5 were measured.

[0230] Each substrate (Poly-Si substrate, TEOS substrate and Si3N4 substrate) used in the above item [Preparation of polished polished object] was cut into 60 mm squares to prepare test substrates. Then, polishing was performed in the same manner as described in the above item [Preparation of polished polished object] to obtain polished polished objects. Thereafter, the polished polished object was mounted on a polishing platen in the following polishing apparatus, and rinsed and polished 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.

[0231] <Rinsing and polishing apparatus and rinsing and polishing conditions (for wettability evaluation)>

[0232] Grinding device: Engis Japan Corporation grinder EJ-380IN-C

[0233] Polishing pad: FUJIBO HOLDINGS, INC. foamed polyurethane pad H800

[0234] Dresser: Nylon brush (manufactured by 3M Company)

[0235] Grinding pressure: 1.0psi

[0236] Grinding plate speed: 60rpm

[0237] Grinding head speed: 60rpm

[0238] Supply of post-CMP cleaning composition: Sagging

[0239] Post-CMP cleaning composition supply amount: 100 mL / min

[0240] Grinding time: 60 seconds.

[0241] After the rinsing and polishing treatment as described above, no post-cleaning treatment is performed, and the surface moisture is removed by air spraying to obtain a polished object that has been rinsed and polished. After that, the water contact angle is measured by the θ / 2 method. It should be noted that the contact angle evaluation device DMo-501 manufactured by Kyowa Interface Science Co., Ltd. is used in the measurement. The results are shown in Table 2 below.

[0242] [Evaluation 3: Measurement of Zeta Potential]

[0243] Prepare 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)] as the measurement object. Set the above measurement object in the solid Zeta potential measuring instrument SurPASS3 (Zeta potentiometer) manufactured by Anton Paar Japan K.K. Next, allow 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 to flow through the measurement object, respectively, and measure the Zeta potential (mV) of these measurement objects, respectively. This value is used as the Zeta potential of each wafer during rinsing and polishing. The results are shown in the following Table 2.

[0244] [Table 2]

[0245]

[0246] As is clear from Table 2, the post-CMP cleaning compositions A1 to A11 of Examples 1 to 11 can reduce the residue on the surface of the polished object including the silicon-containing material as compared with the post-CMP cleaning compositions B1 to B5 of Comparative Examples 1 to 5.

[0247] This application is based on Japanese Patent Application No. 2023-167704 filed on September 28, 2023, and Japanese Patent Application No. 2024-113369 filed on July 16, 2024, the entire disclosures of which are incorporated herein by reference.

Claims

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 is more than 0.1 mass % and less than 1.0 mass % based on the total post-CMP cleaning composition. The pH of the post-CMP cleaning composition is 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 claim 1, 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 claim 1, wherein: The nitrogen-containing nonionic polymer is at least one selected from the group consisting of polyvinyl pyrrolidone, poly-N-vinylacetamide, polydimethylacrylamide, polyvinyl caprolactam, N-isopropylacrylamide and oxazoline group-containing polymers. 5 . The post-CMP cleaning composition according to claim 1 , further comprising a chelating agent having two or more phosphate groups. The post-CMP cleaning composition according to claim 1 , which is substantially free of abrasive particles.

7. A post-chemical mechanical polishing cleaning method, wherein the post-chemical mechanical polishing cleaning composition according to claim 1 is used to perform surface treatment on a polished object comprising at least one selected from the group consisting of silicon oxide, polysilicon and silicon nitride, thereby reducing residue on the surface of the polished object. 8 . The post-CMP cleaning method according to claim 7 , which is a rinse polishing method or a cleaning method.

9. A method for manufacturing a semiconductor substrate, wherein: The polished object is a polished semiconductor substrate, and the manufacturing method includes the following steps: a polishing step of polishing a pre-polished semiconductor substrate comprising at least one selected from the group consisting of silicon oxide, polycrystalline silicon, and silicon nitride using a polishing composition comprising abrasive grains to obtain a polished semiconductor substrate; and, The post-chemical mechanical polishing cleaning step uses the post-chemical mechanical polishing cleaning composition of claim 1 to reduce the residues including the abrasive grains on the surface of the polished semiconductor substrate.

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