Cleaning agent for semiconductor substrate, method for manufacturing cleaned semiconductor substrate, and method for manufacturing electronic device

Abstract

The present invention provides: a cleaning agent for a semiconductor substrate, said cleaning agent having excellent corrosion resistance to copper and excellent ability to remove a ruthenium-containing substance; a method for manufacturing a cleaned semiconductor substrate; and a method for manufacturing an electronic device. A cleaning agent for a semiconductor substrate according to the present invention contains a purine compound selected from purine and purine derivatives, and a specific polymer having a hydroxyl group-containing repeating unit and / or a cationic group, and exhibits alkalinity.

Description

Cleaning agent for semiconductor substrates, method for manufacturing cleaned semiconductor substrates, and method for manufacturing electronic devices

[0001] The present invention relates to a cleaning agent for semiconductor substrates, a method for producing a cleaned semiconductor substrate, and a method for producing an electronic device.

[0002] In the semiconductor field, with the remarkable progress in integration and performance, even trace amounts of impurities (contamination) and / or deposits (particles) have come to have a significant impact on device performance and ultimately product yield. Various types of contamination and particles (hereinafter also referred to as residues) can be generated during each manufacturing process of semiconductor devices. During semiconductor manufacturing, substrate processing processes are appropriately performed to remove such residues.

[0003] For example, in the manufacture of semiconductor devices, a chemical mechanical polishing (CMP) process may be performed to planarize a semiconductor substrate surface having a metal wiring film, a barrier metal, an insulating film, etc., using a polishing slurry containing abrasive particles (e.g., silica, alumina, etc.). In the CMP process, metal components derived from the abrasive particles used in the CMP process, the polished wiring metal film and / or the barrier metal, etc., tend to remain on the polished semiconductor substrate surface and on the members used for polishing (e.g., a polishing pad). For this reason, a process of removing these residues using a semiconductor substrate cleaner is generally performed after the CMP process.

[0004] As described above, in the semiconductor manufacturing process, cleaning agents for semiconductor substrates are used for treatments such as removing unnecessary metal-containing substances, resists, and residues from various components used in the manufacturing of semiconductors. Patent Document 1, for example, discloses a cleaning agent for semiconductor substrates capable of efficiently removing particles from the surface of a semiconductor substrate after chemical mechanical polishing (CMP), which is a "cleaning agent composition for use after a CMP step in a semiconductor manufacturing process, comprising: (1A) at least one compound selected from the group consisting of a nonionic surfactant containing an alkylene oxide adduct of an alcohol having 6 or more carbon atoms and an N-vinyl lactam polymer; (1B) aliphatic amines; and (1C) at least one corrosion inhibitor selected from the group consisting of a nitrogen-containing heterocyclic compound and a carboxylate compound." Furthermore, Patent Document 2 discloses "a cleaning agent for electronic materials, which contains a nonionic surfactant (A) having a cloud point of 35 to 95°C in a 2 wt% aqueous solution, a polymeric anionic surfactant (B) having an aromatic ring and a sulfonic acid group in the molecule and a weight-average molecular weight of 1,000 to 100,000, and water, wherein the cloud point of a 2 wt% aqueous solution of the cleaning agent for electronic materials is 50 to 95°C." Patent Document 3 discloses "a surface treatment composition comprising a nitrogen-free nonionic polymer, a nitrogen-containing nonionic polymer, and an anionic polymer, wherein the weight-average molecular weight of the nitrogen-free nonionic polymer is less than 100,000, the ratio of the weight-average molecular weight of the nitrogen-containing nonionic polymer to the weight-average molecular weight of the nitrogen-free nonionic polymer (nitrogen-containing nonionic polymer / nitrogen-free nonionic polymer) is 0.1 or more and 10 or less, and the pH is less than 7.0."

[0005] International Publication No. 2023 / 282287 Japanese Patent Application Laid-Open No. 2013-151677 Japanese Patent Application Laid-Open No. 2023-148443

[0006] On the other hand, when semiconductor substrates containing copper and ruthenium-containing substances after CMP treatment were cleaned using the cleaning agents specifically disclosed in Patent Documents 1 to 3, it was difficult to achieve both corrosion protection against copper and removability of the ruthenium-containing substances.

[0007] Therefore, an object of the present invention is to provide a cleaning agent for semiconductor substrates that has excellent corrosion prevention properties for copper and excellent removal properties of ruthenium-containing substances. Another object of the present invention is to provide a method for producing a cleaned semiconductor substrate and a method for producing an electronic device.

[0008] As a result of extensive research into solving the above problems, the present inventors have found that the problems can be solved by the following configuration.

[0009] [1] A semiconductor substrate cleaning agent exhibiting alkaline properties, comprising a purine compound selected from purine and purine derivatives, and a specific polymer having a repeating unit having a hydroxyl group and / or a cationic group. [2] The semiconductor substrate cleaning agent according to [1], wherein the purine compound is a compound represented by any one of formulas (A) to (D) described below. [3] The semiconductor substrate cleaning agent according to [1] or [2], wherein the purine compound is a compound selected from adenine, adenosine, guanine, xanthine, uric acid, and derivatives thereof. [4] The semiconductor substrate cleaning agent according to any one of [1] to [3], wherein the specific polymer is a nonionic polymer. [5] The semiconductor substrate cleaning agent according to any one of [1] to [4], wherein the repeating unit having a hydroxyl group is a repeating unit represented by formula (1) described below. [6] The semiconductor substrate cleaning agent according to any one of [1] to [5], wherein the repeating unit having a hydroxyl group is a repeating unit having a hydroxyl group and a cyclic structure. [7] The cleaning agent for semiconductor substrates according to [6], wherein the repeating unit having a hydroxyl group is a repeating unit represented by formula (2) described below. [8] The cleaning agent for semiconductor substrates according to any one of [1] to [7], wherein the mass ratio of the content of the specific polymer to the content of the purine compound is 0.01 to 100.0. [9] The cleaning agent for semiconductor substrates according to any one of [1] to [8], further comprising a specific amine compound selected from a quaternary ammonium compound and a tertiary amine compound.

[10] The cleaning agent for semiconductor substrates according to any one of [1] to [9], further comprising a polymer having an anionic group.

[11] The cleaning agent for semiconductor substrates according to any one of [1] to

[10] , having a pH of 10.0 or higher.

[12] The cleaning agent for semiconductor substrates according to any one of [1] to

[11] , which is used after dilution with a solvent.

[13] The cleaning agent for semiconductor substrates according to any one of [1] to

[12] , which is used for cleaning a semiconductor substrate that has been subjected to a chemical mechanical polishing treatment.

[14] The cleaning agent for semiconductor substrates according to

[13] , wherein the semiconductor substrate contains a copper- and ruthenium-containing material.

[15] A method for producing a cleaned semiconductor substrate, comprising a step of contacting a semiconductor substrate that has been subjected to chemical mechanical polishing treatment with the cleaning agent for semiconductor substrates according to any one of [1] to

[14] .

[16] A method for producing an electronic device, comprising the method for producing a cleaned semiconductor substrate according to

[15] .

[0010] The present invention provides a cleaning agent for semiconductor substrates that has excellent corrosion prevention properties for copper and excellent removal properties for ruthenium-containing substances. The present invention also provides a method for producing a cleaned semiconductor substrate and a method for producing an electronic device.

[0011] The present invention will be described in detail below. The following description of the components may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0012] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. Furthermore, in this specification, when two or more types of a certain component are present, the "content" of that component means the total content of those two or more components. In this specification, in a numerical range described in stages, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in a numerical range described in this specification, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the Examples. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment.

[0013] In this specification, the "total mass of components in a cleaning agent excluding the solvent" means the total mass of all components contained in the cleaning agent other than solvents such as water and organic solvents. Unless otherwise specified, the compounds described in this specification may contain structural isomers, optical isomers, and isotopes. Furthermore, the structural isomers, optical isomers, and isotopes may be contained alone or in combination of two or more types.

[0014] In this specification, when there are multiple substituents and linking groups, etc. (hereinafter referred to as substituents, etc.) represented by a specific symbol, or when multiple substituents, etc. are specified simultaneously, this means that the respective substituents, etc. may be the same or different from each other. The same applies to the specification of the number of substituents, etc. The bonding direction of a divalent group represented in this specification is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "X-Y-Z", Y may be -CO-O- or -O-CO-. Furthermore, the above compound may be either "X-CO-O-Z" or "X-O-CO-Z".

[0015] In this specification, "ppm" means "parts-per-million (10 －６ ) and "ppb" stands for "parts-per-billion (10 －９ In this specification, "(meth)acrylic acid" is a concept that includes both acrylic acid and methacrylic acid, and "(meth)acrylamide" is a concept that includes both acrylamide and methacrylamide.

[0016] In this specification, the term "weight average molecular weight" refers to the weight average molecular weight in terms of polyethylene glycol measured by GPC (gel permeation chromatography).

[0017] [Cleaning Agent for Semiconductor Substrates] The cleaning agent for semiconductor substrates of the present invention (hereinafter also referred to simply as "the cleaning agent") contains a purine compound selected from purines and purine derivatives, and a specific polymer having a repeating unit having a hydroxyl group and / or a cationic group, and is alkaline.

[0018] Although the reason why the present cleaning agent having the above-described configuration can solve the problems of the present invention is not entirely clear, the inventors speculate as follows. Note that the following speculation does not limit the mechanism by which the effects are obtained. In other words, even if the effects are obtained by a mechanism other than the one described below, it is still within the scope of the present invention.

[0019] Residues derived from the CMP polishing solution and the substrate are likely to remain on substrates after CMP processing. Copper is widely used as a wiring material for substrates, and ruthenium is increasingly being used in conjunction with copper in cutting-edge applications. Therefore, post-CMP cleaning agents are required to effectively remove these residues and simultaneously suppress copper corrosion on the substrate. The purine compounds contained in this cleaning agent enhance the corrosion resistance of copper by adsorbing to copper, and the specific polymers also easily adsorb to ruthenium. This is thought to have lifted ruthenium-derived residues from the substrate and effectively removed them. Hereinafter, the achievement of at least one of the effects of superior copper corrosion resistance and superior removal of ruthenium-containing substances when cleaning workpieces using this cleaning agent is also referred to as "excellent effects of the present invention." The components contained in this cleaning agent and its physical properties are described in detail below.

[0020] [Purine Compound] The present cleansing agent contains a purine compound selected from purine and purine derivatives. A purine compound is a compound having a purine skeleton. Specific examples of purine compounds include purine, adenine or a derivative thereof, guanine or a derivative thereof, hypoxanthine or a derivative thereof, xanthine or a derivative thereof, uric acid or a derivative thereof, xanthosine or a derivative thereof, and theobromine or a derivative thereof. Details of each of the above derivatives are provided below. One preferred embodiment of the purine compound is a compound represented by any of the following formulas (A) to (D):

[0021]

[0022] In formula (A), R １ and R ２ each independently represents a hydrogen atom or a specific substituent selected from an alkyl group which may have a substituent, an amino group which may have a substituent, a thiol group, a hydroxyl group, a halogen atom, a sugar group which may have a substituent, and a polyoxyalkylene group-containing group which may have a substituent.

[0023] The alkyl group may be linear, branched, or cyclic, and preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms.

[0024] The amino group may be primary, secondary, or tertiary, but is preferably primary. When the amino group is secondary or tertiary, the amino group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 or 2 carbon atoms.

[0025] Examples of the sugar group include groups in which one hydroxyl group has been removed from a saccharide selected from the group consisting of monosaccharides, disaccharides, and polysaccharides, with groups in which one hydroxyl group has been removed from a monosaccharide being preferred. Examples of monosaccharides include pentoses such as ribose, deoxyribose, arabinose, and xylose, trioses, tetroses, hexoses, and heptoses, with pentoses being preferred, ribose, deoxyribose, arabinose, or xylose being more preferred, and ribose or deoxyribose being even more preferred. Examples of disaccharides include sucrose, lactose, maltose, trehalose, turanose, and cellobiose. Examples of polysaccharides include glycogen, starch, and cellulose. The sugars may be linear or cyclic, with cyclic being preferred. Examples of the cyclic sugars include furanose rings and pyranose rings.

[0026] The polyoxyalkylene group-containing group which may have a substituent refers to a group containing a polyoxyalkylene group which may have a substituent as a part of the group. Examples of the polyoxyalkylene group constituting the polyoxyalkylene group-containing group include a polyoxyethylene group, a polyoxypropylene group, and a polyoxybutylene group, and a polyoxyethylene group is preferred.

[0027] Examples of substituents that the alkyl group, the amino group, the sugar group, and the polyoxyalkylene group-containing group may have include hydrocarbon groups such as alkyl groups, aryl groups, and benzyl groups; halogen atoms such as fluorine atoms, chlorine atoms, and bromine atoms; alkoxy groups; hydroxyl groups; alkoxycarbonyl groups such as methoxycarbonyl groups and ethoxycarbonyl groups; acyl groups such as acetyl groups, propionyl groups, and benzoyl groups; cyano groups; and nitro groups.

[0028] The effect of the present invention is more excellent. １ and R ２ It is preferable that at least one of R represents the specific substituent. １ Among these, a hydrogen atom or an amino group which may have a substituent is preferable as R, and an amino group which may have a substituent is more preferable. １ Another preferred embodiment of R is an alkyl group which may have a substituent, a thiol group, a hydroxyl group, a halogen atom, a sugar group which may have a substituent, or a group containing a polyoxyalkylene group which may have a substituent. ２ Among these, a hydrogen atom, an alkyl group which may have a substituent, or a sugar group which may have a substituent is preferred, a hydrogen atom or a sugar group which may have a substituent is more preferred, and a hydrogen atom is even more preferred.

[0029] In the above formula (B), R ３ ~R ５ R each independently represents a hydrogen atom or the specific substituent. ３ ~R ５ Examples of the groups represented by the formula (A) include R １ or R ２ In terms of the effects of the present invention being more excellent, in the case of the group represented by R ３ ~R ５ Preferably, at least two of R represent hydrogen atoms, and at least R ３ and R ５ It is more preferable that R is a hydrogen atom. ３ and R ５Each of R is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably a hydrogen atom. ４ As the alkyl group, a hydrogen atom, an alkyl group which may have a substituent, or an amino group which may have a substituent is preferred, and a hydrogen atom or an amino group which may have a substituent is more preferred.

[0030] In the above formula (C), R ６ ~R ８ R each independently represents a hydrogen atom or the specific substituent. ６ ~R ８ Examples of the groups represented by the formula (A) include R １ or R ２ Examples of the groups represented by the following formulas are given.

[0031] In terms of the effects of the present invention being more excellent, in formula (C), R ６ ~R ８ It is preferable that at least two of R represent hydrogen atoms. ６ Among these, R is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably a hydrogen atom. ６ Another preferred embodiment of R is an alkyl group which may have a substituent, an amino group which may have a substituent, a thiol group, a hydroxyl group, a halogen atom, a sugar group which may have a substituent, or a group containing a polyoxyalkylene group which may have a substituent. ７ R is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably a hydrogen atom. ８ As the alkyl group, a hydrogen atom or an alkyl group which may have a substituent is preferred, and a hydrogen atom is more preferred.

[0032] In the above formula (D), R ９ ~R １２ R each independently represents a hydrogen atom or the specific substituent. ９ ~R １２ Examples of the groups represented by the formula (A) include R １ or R ２ In terms of the effects of the present invention being more excellent, in the case of the group represented by R ９ ~R １２Preferably, at least two of R represent hydrogen atoms, ９ ~R １２ It is more preferable that three or more of R represent hydrogen atoms. ９ ~R １２ As the alkyl group, a hydrogen atom or an alkyl group which may have a substituent is preferred, and a hydrogen atom is more preferred.

[0033] As the purine compound, a compound selected from adenine, adenosine, guanine, hypoxanthine, xanthine, uric acid, and derivatives thereof is preferred, a compound selected from adenine, adenosine, guanine, xanthine, uric acid, and derivatives thereof is more preferred, and a compound selected from adenine, adenosine, guanine, xanthine, uric acid, and derivatives thereof is even more preferred.

[0034] Examples of adenine or a derivative thereof include adenine, 1-methyladenine, 1-ethyladenine, 1-benzyladenine, 2-methyladenine, 2-chloroadenine, 2-fluoroadenine, 2-hydroxyadenine, 3-methyladenine, 8-aminoadenine, 9-methyladenine, 9-(2-hydroxyethyl)adenine, N-(2-hydroxyethyl)adenine, N-methyladenine, N,N-dimethyladenine, 2-azaadenine, 5-azaadenine, 8-azaadenine, and N ６ Examples of adenosine or derivatives thereof include adenosine, 2'-deoxyadenosine, and 2',3'-isopropylidene adenosine. Examples of guanine or derivatives thereof include guanine, N-methylguanine, N-acetylguanine, O-cyclohexylmethylguanine, 7-(2-hydroxyethyl)guanine, N-(3-chlorophenyl)guanine, N-(3-ethylphenyl)guanine, 8-azaguanine, guanine oxime, 2'-deoxyguanosine, guanosine 5'-monophosphate disodium, and N ２-isobutyryl-2'-deoxyguanosine. Hypoxanthine or a derivative thereof includes, for example, hypoxanthine and 8-azahypoxanthine. Examples of xanthine or derivatives thereof include caffeine, theophylline, theophylline-7-acetic acid, 7-(2,3-dihydroxypropyl)theophylline, 7-(2-chloroethyl)theophylline, 8-chlorotheophylline, xanthine, 1-methylxanthine, 1-butyl-3,7-dimethylxanthine, 1-methyl-3,7-dipropylxanthine, 1,3-dipropyl-7-methylxanthine, 1,3-dipropyl-7-methyl-8-dicyclopropylmethylxanthine, 1,3-dibutyl-7-(2-oxopropyl)xanthine, 1,7-dimethylxanthine, 1,7-dipropyl-3-methylxanthine, 3-methylxanthine, 3,7-dimethyl-1-propylxanthine, 7-methylxanthine, 8-bromo-3-methylxanthine, 8-azaxanthine, 2-thioxanthine, and paraxanthine. Examples of uric acid or its derivatives include uric acid, 3-N-methyluric acid, 3-N-lauryluric acid, 7-N-butyluric acid, 1-N-ethyluric acid, 9-N-lauryluric acid, and 3,7-N-dimethyluric acid. Examples of xanthosine or its derivatives include xanthosine and 7-methylxanthosine. Examples of theobromine or its derivatives include theobromine and 1-(3-chloropropyl)theobromine.

[0035] Examples of purine compounds other than those mentioned above include purine, 6-mercaptopurine, 2-aminopurine, 2-amino-6-methoxypurine, 2-amino-6-iodopurine, 2-amino-6-chloropurine, 2,6-diaminopurine, 2,6-dichloropurine, 3,7-dihydro-7-methyl-1H-purine-2,6-dione, 6-aminopurine, 6-methoxypurine, 6-(dimethylamino)purine, 6-benzylaminopurine, 6-chloro-9-(tetrahydropyran-2-yl)purine, 6-amino-8 -phenyl-9H-purine, 6-ethylaminopurine, and 8-azapurine, isoguanine, enprofylline, eritadenine, nelarabine, vidarabine, acyclovir, trans-zeatin, entecavir, valacyclovir, abacavir, inosinate disodium, ganciclovir, β-nicotinamide adenine dinucleotide phosphate, clofarabine, kinetin, proxyphylline, 2',3'-dideoxyinosine, penciclovir, adefovir dipivoxil, and inosine.

[0036] The purine compounds may be used alone or in combination of two or more. The content of the purine compounds is preferably 0.00001 to 0.1 mass%, more preferably 0.0001 to 0.05 mass%, and even more preferably 0.0001 to 0.01 mass%, based on the total mass of the present cleaning agent. The content of the purine compounds is preferably 0.01 to 50.0 mass%, more preferably 0.01 to 25.0 mass%, and even more preferably 0.1 to 20.0 mass%, based on the total mass of the components in the cleaning agent excluding the solvent. In order to achieve superior effects of the present invention, the mass ratio of the content of the specific polymer described below to the content of the purine compounds is preferably 0.001 to 150.0 mass%, more preferably 0.01 to 100.0 mass%, and even more preferably 0.01 to 5.0 mass.

[0037] [Specific Polymer] The present cleaning agent contains a specific polymer. As described above, the specific polymer is a polymer having at least one of a repeating unit having a hydroxyl group and a cationic group. That is, examples of the specific polymer include a polymer having a repeating unit having a hydroxyl group and a polymer having a cationic group, and a polymer having a repeating unit having a hydroxyl group is preferred. The specific polymer is preferably a nonionic polymer. A nonionic polymer refers to a polymer that does not have an ionic group such as a cationic group or an anionic group. Therefore, the specific polymer is preferably a polymer that has a repeating unit having a hydroxyl group and does not have an ionic group such as a cationic group or an anionic group. In a polymer having a cationic group, the cationic group may be located at the terminal or on a side chain. The polymer having a cationic group is preferably a polymer that has a repeating unit having a cationic group.

[0038] The number of hydroxyl groups in the repeating unit having a hydroxyl group is not particularly limited, but is preferably 1 to 6, more preferably 1 to 5, and even more preferably 1 to 3. The repeating unit having a hydroxyl group is also preferably a repeating unit having a hydroxyl group and a cyclic structure. The number of ring atoms in the cyclic structure is preferably 4 to 20, more preferably 4 to 10, and even more preferably 4 to 6. The cyclic structure may be either an alicyclic structure or an aromatic ring structure, but an alicyclic structure is preferred. In addition, the cyclic structure preferably has an oxygen atom as a ring atom.

[0039] As the repeating unit having a hydroxyl group, for example, a repeating unit represented by the following formula (1) is preferred.

[0040]

[0041] In formula (1), L １ represents a single bond or a divalent linking group. １ is preferably a single bond. １Examples of the divalent linking group represented by the formula (I) include a divalent aliphatic hydrocarbon group, a divalent aromatic group, and a group formed by combining two or more of these groups. The divalent aliphatic hydrocarbon group has, between carbon atoms, -O- (ethereal oxygen atom), -S- (thioethereal sulfur atom), -CO- (carbonyl group), or -NR Ｃ - (R Ｃ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0042] The divalent aliphatic hydrocarbon group may be linear, branched, or cyclic, but is preferably linear or branched. Examples of the divalent aliphatic hydrocarbon group include an alkylene group, an alkenylene group, and an alkynylene group, with an alkylene group being preferred. The divalent aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms.

[0043] The divalent aromatic group may be either a divalent aromatic hydrocarbon group or a divalent aromatic heterocyclic group, with an aromatic hydrocarbon group being preferred. The aromatic ring constituting the divalent aromatic group may be either a monocyclic or polycyclic ring. Examples of polycyclic rings include fused rings formed by condensing two or more monocyclic rings, and linked rings formed by connecting two or more rings selected from monocyclic rings and fused rings with a single bond. Specific examples of aromatic rings constituting the divalent aromatic group include a benzene ring, a naphthalene ring, a thiophene ring, an indole ring, a carbazole ring, a benzothiophene ring, and aromatic rings formed by connecting two or more of these with a single bond. The number of carbon atoms in the divalent aromatic group is preferably 4 to 25, more preferably 6 to 20, and even more preferably 6 to 10.

[0044] The divalent aliphatic hydrocarbon group and the divalent aromatic group may have a substituent. Examples of the substituent that the divalent aliphatic hydrocarbon group may have include a halogen atom. Examples of the substituent that the divalent aromatic group may have include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a halogen atom.

[0045] In the above formula (1), L ２ is a single bond, a methylene group, or —CH ２Represents O-. ２ is a single bond or -CH ２ O- is preferred.

[0046] Examples of the specific polymer having a repeating unit represented by formula (1) include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, vinyl acetate-vinyl alcohol copolymer, polyglycerin, and polyglycerin derivatives. Of these, polyvinyl alcohol or polyglycerin is preferred as the specific polymer having a repeating unit represented by formula (1).

[0047] Furthermore, examples of the repeating unit having a hydroxyl group and a cyclic structure include a repeating unit represented by formula (2).

[0048]

[0049] In formula (2), R each independently represents a hydrogen atom or an alkyl group which may have a hydroxyl group. However, at least one of the multiple R's represents a hydrogen atom or an alkyl group which has a hydroxyl group. The alkyl group which may have a hydroxyl group may be linear, branched, or cyclic, but linear or branched is preferred. The number of carbon atoms in the alkyl group which may have a hydroxyl group is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 3. Among these, the alkyl group which may have a hydroxyl group is preferably an alkyl group in which one hydrogen atom in a linear or branched alkyl group having 1 to 6 carbon atoms may be substituted with a hydroxyl group.

[0050] Examples of the specific polymer having a repeating unit represented by formula (2) include cellulose derivatives, such as cellulose ethers, cellulose esters, and cellulose ether esters.

[0051] Examples of cellulose ethers include alkyl cellulose ethers such as methyl cellulose, ethyl cellulose, ethyl methyl cellulose, ethyl propyl cellulose, isopropyl cellulose, and butyl cellulose; hydroxyalkyl cellulose ethers such as hydroxymethyl cellulose, hydroxyethyl cellulose, methyl-2-hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and hydroxypropyl ethyl cellulose; carboxyalkyl cellulose ethers such as carboxymethyl cellulose and carboxymethyl ethyl cellulose; aralkyl cellulose ethers such as benzyl cellulose; and cyanoalkyl cellulose ethers such as cyanoethyl cellulose.

[0052] Examples of cellulose esters include cellulose acetate butyrate, cellulose acetate (cellulose acetate), cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose phthalate, and cellulose acetate phthalate.

[0053] Examples of cellulose ether esters include hydroxymethyl cellulose acetate succinate, hydroxypropyl methyl cellulose acetate succinate, hydroxypropyl cellulose phthalate, and hydroxypropyl methyl cellulose phthalate.

[0054] Specific examples of the specific polymer include those mentioned above, as well as gum arabic (acacia gum), sodium alginate, chitosan, xanthan gum, tragacanth, guar gum, carrageenan, pullulan, tamarind gum, and locust bean gum.

[0055] Furthermore, examples of the polymer having a cationic group (hereinafter simply referred to as a "cationic polymer") as the specific polymer include polymers containing a group (cationic group) that exhibits cationicity at pH 3 to 8 (particularly preferably at pH 3 to 4). Examples of the cationic group include -NR Ａ RＢ or -N ＋ R Ａ R Ｂ R Ｃ ・X － and a monovalent group represented by -NR Ａ -or-N ＋ R Ａ R Ｂ -X － A divalent group represented by (R Ａ , R Ｂ and R Ｃ Each independently represents a hydrogen atom or an organic group (e.g., an alkyl group). － represents a counter anion. ) is preferred. For preferred embodiments of the cationic polymer, please refer to the contents of paragraphs

[0067] to

[0074] of Japanese Patent No. 7175965, the contents of which are incorporated herein by reference. Among these, polyethyleneimine is preferred as the cationic polymer.

[0056] The weight average molecular weight of the specific polymer is preferably from 500 to 1,000,000, more preferably from 1,000 to 500,000, and even more preferably from 1,500 to 100,000.

[0057] The specific polymer may be used alone or in combination of two or more. The content of the specific polymer is preferably 0.00001 to 0.1 mass%, more preferably 0.0001 to 0.05 mass%, and even more preferably 0.0001 to 0.01 mass%, based on the total mass of the cleaning agent. The content of the specific polymer is preferably 0.001 to 40.0 mass%, more preferably 0.01 to 40.0 mass%, and even more preferably 0.1 to 37.0 mass%, based on the total mass of the components in the cleaning agent excluding the solvent.

[0058] [Amine Compound] The present cleaning agent preferably contains an amine compound. However, the above-mentioned purine compounds are not included in the amine compounds. The amine compound is a compound having at least one group selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and a quaternary ammonium cation group in the molecule, or a salt thereof. When an amine has amino groups of different series, the amine is classified as the amine having the highest group among them. Examples of salts of amine compounds include salts with inorganic acids formed by bonding at least one nonmetal selected from the group consisting of Cl, S, N, and P with hydrogen, and hydrochlorides, sulfates, or nitrates are preferred.

[0059] The amine compound is different from the polymer having a cationic group in that it does not have a repeating unit. The molecular weight of the amine compound is preferably 50 to 1,000, more preferably 100 to 800, and even more preferably 100 to 500.

[0060] The amine compound preferably exhibits alkaline properties in aqueous solution (a pH of greater than 7.0 at 25°C). Among these, amines that have a pH of 9.0 to 14.0 at 25°C when dissolved at a concentration of 0.1 mol / L are more preferred, and amines with a pH of 10.0 to 13.0 are even more preferred. The amine compound may be either chain (linear or branched) or cyclic. Examples of amine compounds include quaternary ammonium compounds, amino alcohols (alkanolamines), amino alcohols, aliphatic amines, and alicyclic amines. It is particularly preferred that the present cleaning agent further contains a specific amine compound selected from quaternary ammonium compounds and tertiary amine compounds.

[0061] <Quaternary ammonium compound> The quaternary ammonium compound is not particularly limited as long as it is a compound having at least one quaternary ammonium cation group formed by substituting four hydrocarbon groups (preferably alkyl groups) on a nitrogen atom, or a salt thereof. Examples of the quaternary ammonium compound include quaternary ammonium hydroxide, quaternary ammonium fluoride, quaternary ammonium bromide, quaternary ammonium iodide, quaternary ammonium acetate, and quaternary ammonium carbonate. Among these, quaternary ammonium hydroxide is preferred, and a compound represented by the following formula (a1) is more preferred.

[0062]

[0063] In the above formula (a1), R ａ１ ~R ａ４ R each independently represents an alkyl group having 1 to 16 carbon atoms, an aryl group having 6 to 16 carbon atoms, an aralkyl group having 7 to 16 carbon atoms, or a hydroxyalkyl group having 1 to 16 carbon atoms. ａ１ ~R ａ４ At least two of the groups may be bonded to each other to form a ring structure.

[0064] As the compound represented by the above formula (a1), from the viewpoint of availability, a compound selected from the group consisting of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide, tetrabutylammonium hydroxide (TBAH), methyltripropylammonium hydroxide, methyltributylammonium hydroxide, ethyltrimethylammonium hydroxide, methyltriethylammonium hydroxide (MTEAH), dimethyldiethylammonium hydroxide, benzyltrimethylammonium hydroxide (BzTMAH), hexadecyltrimethylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide, and spiro-(1,1')-bipyrrolidinium hydroxide is preferred, and ethyltrimethylammonium hydroxide is more preferred.

[0065] <Amino alcohol> An amino alcohol is an amine compound that further has at least one hydroxyalkyl group in the molecule. The amino alcohol may have any of primary to tertiary amino groups, but preferably has a tertiary amino group. The number of amino groups that the amino alcohol has is, for example, 1 to 5, and preferably 1 to 3. The number of hydroxyl groups that the amino alcohol has is, for example, 1 to 5, and more preferably 1 to 3.

[0066] Examples of amino alcohols include monoethanolamine (MEA), 3-amino-1-propanol, 1-amino-2-propanol, trishydroxymethylaminomethane (Tris), 2-amino-2-methyl-1-propanol (AMP), 2-dimethylamino-2-methyl-1-propanol (DMAMP), 2-amino-2-methyl-1,3-propanediol (AMPDO), 2-amino-2-ethyl-1,3-propanediol (AEPDO), 2-amino-1,3-propanediol (2-APDO), 3-amino-1,2-propanediol (3-APDO), 3-methylamino-1,2-propanediol (MAPDO), 2-(methylamino)-2-methyl-1-propanediol (N 2-(2-aminoethoxy)ethanol (AEE), 2-(2-aminoethylamino)ethanol (AAE), diethanolamine (DEA), triethanolamine (TEA), N-methylethanolamine, N-butylethanolamine, N-cyclohexylethanolamine, 2-(ethylamino)ethanol, propylaminoethanol, diethylene glycolamine (DEGA), N,N'-bis(2-hydroxyethyl)ethylenediamine, 1,2-bis(2-aminoethoxy)ethane, N-methyldiethanolamine, N-tert-butyldiethanolamine, N-butyldiethanolamine, 1-piperidineethanol, and 1-(2-hydroxyethyl)piperazine. Of these, DMAP or N-methyldiethanolamine is preferred.

[0067] <Aliphatic Amines> Examples of aliphatic amines other than amino alcohols include primary aliphatic amines (aliphatic amines having a primary amino group), secondary aliphatic amines (aliphatic amines having a secondary amino group), and tertiary aliphatic amines (aliphatic amines having a tertiary amino group), with tertiary aliphatic amines being preferred.

[0068] Examples of primary aliphatic amines include methylamine, ethylamine, propylamine, dimethylamine, diethylamine, n-butylamine, 3-methoxypropylamine, tert-butylamine, n-hexylamine, n-octylamine, and 2-ethylhexylamine. Examples of secondary aliphatic amines include alkylenediamines such as ethylenediamine (EDA), 1,3-propanediamine (PDA), 1,2-propanediamine, 1,3-butanediamine, and 1,4-butanediamine; and polyalkylpolyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), bis(aminopropyl)ethylenediamine (BAPEDA), and tetraethylenepentamine. Examples of tertiary aliphatic amines include tertiary alkylamines such as trimethylamine and triethylamine; alkylenediamines such as 1,3-bis(dimethylamino)butane; and polyalkylpolyamines such as N,N,N',N'',N''-pentamethyldiethylenetriamine.

[0069] <Alicyclic amines> Examples of alicyclic amines include cyclic amidine compounds and piperazine compounds. Compounds included in amino alcohols are not included in alicyclic amines.

[0070] The cyclic amidine compound is a compound having a heterocycle containing an amidine structure (>N—C═N—) in the ring. The number of ring members in the heterocycle of the cyclic amidine compound is preferably 5 to 6, and more preferably 6. Examples of cyclic amidine compounds include diazabicycloundecene (1,8-diazabicyclo[5.4.0]undec-7-ene: DBU), diazabicyclononene (1,5-diazabicyclo[4.3.0]non-5-ene: DBN), 3,4,6,7,8,9,10,11-octahydro-2H-pyrimido[1.2-a]azocine, 3,4,6,7,8,9-hexahydro-2H-pyrido[1.2-a]pyrimidine, 2,5,6,7-tetrahydro-3H-pyrrolo[1.2-a]imidazole, 3-ethyl-2,3,4,6,7,8,9,10-octahydropyrimido[1.2-a]azepine, and creatinine.

[0071] The piperazine compound is a compound having a 6-membered heterocyclic ring (piperazine ring) in which opposing >CH- groups of a cyclohexane ring are replaced with tertiary amino groups (>N-). Examples of the piperazine compound include piperazine, 1-methylpiperazine, 2-methylpiperazine, 1-ethylpiperazine, 1-propylpiperazine, 1-butylpiperazine, 1,4-dimethylpiperazine, 2,5-dimethylpiperazine, 2,6-dimethylpiperazine, 1-phenylpiperazine, N-(2-aminoethyl)piperazine (AEP), 1,4-bis(2-aminoethyl)piperazine (BAEP), 1,4-bis(3-aminopropyl)piperazine (BAPP), and 1,4-diazabicyclo[2.2.2]octane (DABCO).

[0072] Examples of alicyclic amines other than piperazine compounds and cyclic amidine compounds include compounds having a nitrogen-containing 5-membered ring or a nitrogen-containing 7-membered ring, such as 1,3-dimethyl-2-imidazolidinone.

[0073] <Basic Amino Acid> The amine compound may be a basic amino acid. Examples of basic amino acids include arginine, histidine, lysine, ornithine, 2,4-diaminobutyric acid, tryptophan, asparagine, and glutamine. The basic amino acid may be in any of the D-, L-, and DL-forms.

[0074] The amine compounds may be used alone or in combination of two or more. The content of the amine compounds is preferably 0.001 to 1.0 mass%, more preferably 0.001 to 0.1 mass%, and even more preferably 0.01 to 0.1 mass%, based on the total mass of the cleaning agent. The content of the amine compounds is preferably 1.0 to 96.0 mass%, more preferably 50.0 to 93.0 mass%, and even more preferably 60.0 to 93.0 mass%, based on the total mass of the components in the cleaning agent excluding the solvent.

[0075] [Polymer Having Anionic Groups] The present cleaning agent may further contain a polymer having anionic groups (hereinafter simply referred to as "anionic polymer"). The anionic group is not particularly limited as long as it is a group that exhibits anionic properties in aqueous solution, but a carboxy group or a sulfonic acid group is preferred. The anionic polymer preferably has a hydrophilic moiety derived from the anionic group and a hydrophobic moiety (e.g., a moiety derived from the main chain).

[0076] The anionic polymer is preferably a polymer containing a repeating unit having an anionic group (hereinafter also referred to as "repeating unit A"). The anionic polymer may have a repeating unit other than the repeating unit A, but is preferably a polymer consisting only of the repeating unit A. The anionic polymer may have two or more types of repeating unit A. In terms of achieving better effects of the present invention, the anionic polymer is preferably a polymer consisting only of a repeating unit A selected from the group consisting of a repeating unit having a carboxy group and a repeating unit having a sulfonic acid group.

[0077] <Repeating Unit A> The repeating unit A is a repeating unit having an anionic group. The number of acid groups contained in the repeating unit A is not particularly limited, but is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2.

[0078] Examples of the repeating unit A include repeating units derived from a compound having an anionic group and an ethylenically unsaturated group. The ethylenically unsaturated group is a functional group having an ethylenically unsaturated bond. Examples of the ethylenically unsaturated group include an aromatic vinyl group and an acryloyloxy group (CH ２ ═CH—COO—), methacryloyloxy group (CH ２ = CCH ３ -COO-), acrylamide group (CH ２ ═CH—CONH—), methacrylamide group (CH ２ = CCH ３ Examples of the ethylenically unsaturated group include an aromatic vinyl group, an acryloyloxy group, a methacryloyloxy group, an acrylamide group, and a vinyl group. Of the aromatic vinyl groups, a styryl group is preferred.

[0079] The repeating unit A is preferably a repeating unit represented by formula (a).

[0080]

[0081] In formula (a), R ａ１ , R ａ２ and R ａ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an anionic group. ａ represents a single bond or a (k+1)-valent linking group. A represents an anionic group. k represents an integer of 1 to 4. When a plurality of anionic groups are present in formula (a), the plurality of anionic groups may be the same or different. ａ When is a single bond, k represents 1.

[0082] R ａ１ , R ａ２ and R ａ３is preferably a hydrogen atom, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), a methyl group, an ethyl group, or a carboxy group, and more preferably a hydrogen atom, a methyl group, or a carboxy group. ａ１ , R ａ２ and R ａ３ It is preferred that one of represents a hydrogen atom, a methyl group or a carboxy group, and the remaining two each represent a hydrogen atom.

[0083] L ａ The (k+1)-valent linking group represented by the formula (I) is not particularly limited as long as it is a group having a valence corresponding to the number of A, and examples thereof include optionally substituted di- to pentavalent aliphatic hydrocarbon groups, optionally substituted di- to pentavalent aromatic hydrocarbon groups, optionally substituted di- to pentavalent aromatic heterocyclic groups, -O-, -CO-, -SO ２ -, -NR Ｌ -, -N<, and groups formed by combining these. Ｌ represents a hydrogen atom or a monovalent aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched, or cyclic. k is preferably 1, and in this case, L ａ Examples of the divalent linking group represented by the formula (I) include a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, —O—, —CO—, —SO ２ -, -NR Ｌ Among these, a single bond, —CO—O—, —CO—NH—, an alkylene group having 1 to 5 carbon atoms, a phenylene group, and a group formed by combining these are preferred.

[0084] The anionic group represented by A is preferably a carboxy group. k represents an integer of 1 to 4, preferably 1 or 2.

[0085] Examples of the repeating unit A include repeating units derived from a compound selected from the group consisting of acrylic acid, maleic acid, itaconic acid, vinyl acetic acid, allyl acetic acid, fumaric acid, p-styrenesulfonic acid, vinylphosphonic acid, vinyl phosphoric acid, vinylsulfonic acid, and 2-acrylamido-2-methyl-1-propanesulfonic acid.

[0086] The content of the repeating unit A is not particularly limited, but is preferably 50 to 100 mol %, more preferably 75 to 100 mol %, and even more preferably 90 to 100 mol %, based on the total repeating units of the anionic polymer.

[0087] Specific examples of the anionic polymer include poly(meth)acrylic acid, polyitaconic acid, polymaleic acid, polyfumaric acid, polyaspartic acid, polyglutamic acid, polystyrenesulfonic acid, polyvinylsulfonic acid, polyallylsulfonic acid, poly(2-acrylamido-2-methyl-1-propanesulfonic acid), 2-acrylamido-2-methyl-1-propanesulfonic acid-acrylic acid copolymer, polyphosphoric acid, polyvinylphosphonic acid, polyvinylphosphonic acid, and styrenesulfonic acid-acrylic acid-vinylphosphonic acid copolymer, with poly(meth)acrylic acid being preferred.

[0088] The weight average molecular weight of the anionic polymer is preferably from 500 to 80,000, more preferably from 1,000 to 30,000, still more preferably from 3,000 to 20,000, and particularly preferably from 4,000 to 10,000.

[0089] The anionic polymer may be used alone or in combination of two or more. The content of the anionic polymer is preferably 0.00001 to 0.01 mass%, more preferably 0.0001 to 0.05 mass%, and even more preferably 0.001 to 0.05 mass%, based on the total mass of the cleaning agent. The content of the anionic polymer is preferably 0.001 to 10.0 mass%, more preferably 0.01 to 5.0 mass%, and even more preferably 0.1 to 5.0 mass%, based on the total mass of the components in the cleaning agent excluding the solvent.

[0090] [Water] The present cleaning agent preferably contains water. The type of water may be any type that does not adversely affect semiconductor substrates, and distilled water, deionized (DI) water, and pure water (ultrapure water) can be used. Pure water (ultrapure water) is preferred because it contains almost no impurities and has less of an effect on semiconductor substrates during the semiconductor substrate manufacturing process. The water content may be the balance of the components that can be contained in the present cleaning agent. The water content is preferably 60.0 mass% or more, more preferably 80.0 mass% or more, even more preferably 90.0 mass% or more, and particularly preferably 97.0 mass% or more, based on the total mass of the present cleaning agent. The upper limit is preferably 99.99 mass% or less, and more preferably 99.9 mass% or less, in order to achieve better effects of the present invention.

[0091] [Other Components] The present cleaning agent may contain other components in addition to those described above, such as organic acids, organic solvents, anticorrosives other than purine compounds, oxidizing agents, reducing agents, and fluorides.

[0092] <Organic Acid> Examples of organic acids include carboxylic acids such as aliphatic carboxylic acids and aromatic carboxylic acids, and phosphonic acids. The anionic polymers are not included in the organic acids. The organic acids may be in the form of a salt. Examples of the salt include inorganic salts.

[0093] Examples of aliphatic carboxylic acids include succinic acid, tartaric acid, maleic acid, oxalic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, formic acid, citric acid, malic acid, glycolic acid, gluconic acid, heptonic acid, and lactic acid. Examples of aromatic carboxylic acids include phenyllactic acid, hydroxyphenyllactic acid, phenylsuccinic acid, phthalic acid, isophthalic acid, terephthalic acid, gallic acid, trimellitic acid, mellitic acid, and cinnamic acid.

[0094] As the phosphonic acid, for example, the compounds described in paragraphs

[0026] to

[0036] of WO 2018 / 020878 and the compounds ((co)polymers) described in paragraphs

[0031] to

[0046] of WO 2018 / 030006 can be used, the contents of which are incorporated herein by reference.

[0095] The organic acids may be used alone or in combination of two or more. The content of the organic acid is preferably 0.00001 to 0.01 mass%, more preferably 0.0001 to 0.05 mass%, and even more preferably 0.001 to 0.05 mass%, based on the total mass of the cleaning agent. The content of the organic acid is preferably 0.001 to 10.0 mass%, more preferably 0.01 to 5.0 mass%, and even more preferably 0.1 to 5.0 mass%, based on the total mass of the components in the cleaning agent excluding the solvent.

[0096] <Organic Solvent> Examples of the organic solvent include known organic solvents, such as alcohol-based solvents, glycol-based solvents, glycol ether-based solvents, and ketone-based solvents. The organic solvent is preferably miscible with water at any ratio. Examples of the organic solvent include the compounds exemplified in paragraphs

[0135] to

[0140] of WO 2022 / 044893, the contents of which are incorporated herein by reference.

[0097] <Anticorrosive Agents Other Than Purine Compounds> Anticorrosive agents other than purine compounds include, for example, heterocyclic compounds other than the above-mentioned purine compounds. As heterocyclic compounds, nitrogen-containing heterocyclic compounds in which at least one of the heteroatoms constituting the heterocycle is a nitrogen atom are preferred. Examples of nitrogen-containing heterocyclic compounds include azole compounds, pyrrole compounds, pyridine compounds, pyrazine compounds, pyrimidine compounds, indole compounds, indolizine compounds, indazole compounds, quinoline compounds, and oxazole compounds, with purine compounds or azole compounds being preferred. Specific examples of anticorrosive agents include the compounds described in paragraphs

[0046] to

[0050] of WO 2021 / 166571, the contents of which are incorporated herein by reference.

[0098] <Oxidizing Agent> Examples of the oxidizing agent include peroxides (hydrogen peroxide, etc.), persulfides (e.g., monopersulfides and dipersulfides), percarbonates, acids thereof, and salts thereof. Examples of the oxidizing agent include oxide halides (periodic acids such as iodic acid, metaperiodic acid, and orthoperiodic acid, and salts thereof), perboric acid, perborates, cerium compounds, and ferricyanides (potassium ferricyanide, etc.).

[0099] <Reducing Agent> Examples of reducing agents include catechol or derivatives thereof (e.g., methylcatechol, gallic acid, pyrogallol, ellagic acid, catechol-4-acetic acid, catechin, and isoflavone), ascorbic acid or derivatives thereof (e.g., isoascorbic acid, ascorbic acid sulfate, and ascorbic acid phosphate), and mercapto compounds (e.g., mercaptosuccinic acid, 1-thioglycerol, 2-mercaptoethanol, 3-mercapto-1-propanol, and thioglycolic acid). Compounds described in paragraphs

[0054] to

[0065] of WO 2019 / 187868 can also be used as reducing agents, and the contents of these compounds are incorporated herein by reference.

[0100] Fluorides are compounds that serve as a source of fluorine-containing ions, and examples thereof include compounds containing fluorine-containing ions and cations. Examples of the fluorine-containing ions include fluoride ions (F － ), bifluoride ion (HF ２ － ), and fluoride-containing ions (e.g., MF ６ ｎ－ , M: any atom, n: 1 to 3). Examples of M include B, Al, Si, P, Ti, Zr, Nb, Sb, and Ta. Specific examples of fluorides include HF, NH ４ F, H ２ SiF ６ , H ２ TiF ６ , H ２ ZrF ６ , HPF ６ , and HBF ４ Examples include:

[0101] [Physical Properties of the Present Cleaning Agent] <pH> As described above, the present cleaning agent is alkaline, and the pH is preferably 8.0 or higher, more preferably 9.0 or higher, and even more preferably 10.0 or higher. There is no particular upper limit, but an example is 14.0 or lower. The pH of the present cleaning agent can be measured using a known pH meter according to the method in accordance with JIS Z8802-1984. The pH is measured at 25°C.

[0102] <Metal Content> The content (measured as ion concentration) of metals (e.g., metal elements Fe, Co, Na, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, Sn, and Ag) contained as impurities in the present cleaning agent is preferably 5 ppm by mass or less, more preferably 1 ppm by mass or less. Since it is expected that even higher purity cleaning agents will be required in the production of cutting-edge semiconductor devices, the content of the above metals is more preferably lower than 1 ppm by mass, i.e., on the order of ppb by mass or less, particularly preferably 100 ppb by mass or less, and most preferably less than 10 ppb by mass. The lower limit is preferably 0.

[0103] Methods for reducing the metal content include, for example, purification treatments such as distillation and filtration using ion exchange resins or filters at the stage of raw materials used in producing the present cleaning agent or at the stage after production of the present cleaning agent. Another method for reducing the metal content is to use a container that minimizes the elution of impurities, as described below, for storing raw materials or the produced present cleaning agent. Another method is to line the inner walls of piping with fluororesin to prevent metal components from eluting from the piping during production of the present cleaning agent.

[0104] <Coarse Particles> The present cleaning agent may contain coarse particles, but the content of coarse particles is preferably low. Coarse particles refer to particles with a diameter (particle size) of 0.03 μm or more when considered as a sphere. The coarse particles contained in the present cleaning agent include particles such as dust, dirt, organic solids, and inorganic solids contained as impurities in the raw materials, as well as particles such as dust, dirt, organic solids, and inorganic solids brought in as contaminants when preparing the cleaning agent, and which ultimately remain as particles in the present cleaning agent without dissolving.

[0105] The content of coarse particles in the present cleaning agent is preferably 10,000 or less, more preferably 5,000 or less, of particles with a particle size of 0.1 μm or more per mL of the cleaning agent. The lower limit is preferably 0 or more, more preferably 0.01 or more, per mL of the cleaning agent. The content of coarse particles in the present cleaning agent can be measured in the liquid phase using a commercially available measuring device that uses a laser as a light source for light scattering liquid particle measurement. Methods for removing coarse particles include, for example, purification processes such as filtering, which will be described later.

[0106] <Abrasive Particles> Preferably, the present cleaning agent is substantially free of abrasive particles. "Substantially free of abrasive particles" specifically means that the content of abrasive particles is 1,000 ppm by mass or less, preferably 500 ppm by mass or less, and more preferably 100 ppm by mass or less, relative to the total mass of the present cleaning agent. The lower limit is preferably 0% by mass or more, relative to the total mass of the present composition. Examples of abrasive particles include abrasive particles such as silicon oxide contained in chemical mechanical polishing slurries and those described in paragraphs

[0194] to

[0197] of WO 2021 / 131451. Examples of methods for measuring the content of abrasive particles include a method of measuring in the liquid phase using a commercially available measuring device that uses a laser as a light source for light scattering liquid particle measurement. Examples of methods for adjusting the content of abrasive particles include known methods such as filtering.

[0107] [Method for producing the present detergent] The present detergent can be produced by a known method, which will be described in detail below.

[0108] [Solution Preparation Step] The present cleaning agent can be produced, for example, by mixing the above-mentioned components. A method for preparing the present cleaning agent includes, for example, sequentially adding the purine compound, the specific polymer, and, if necessary, any optional components to a container containing purified water, followed by stirring to mix the components, and, if necessary, adding a pH adjuster to adjust the pH of the mixture to prepare the cleaning agent. When adding the components to the container, they may be added all at once or in multiple installments.

[0109] The stirring device and stirring method used to prepare the present cleaning agent may be a known device such as a stirrer or disperser. Examples of stirrers include industrial mixers, portable stirrers, mechanical stirrers, and magnetic stirrers. Examples of dispersers include industrial dispersers, homogenizers, ultrasonic dispersers, and bead mills.

[0110] The mixing of the components in the preparation process of the present cleaning agent, the purification treatment described below, and the storage of the produced cleaning agent are preferably carried out at 40° C. or lower, more preferably at 30° C. or lower. The lower limit is preferably 5° C. or higher, more preferably 10° C. or higher. By preparing, treating, and / or storing the present cleaning agent within the above temperature range, the performance can be maintained stably for a long period of time.

[0111] <Purification> It is preferable to perform a purification treatment in advance on one or more of the raw materials used to prepare the present cleaning agent. Examples of purification treatment include known methods such as distillation, ion exchange, and filtration. The degree of purification is preferably such that the raw materials have a purity of 99% by mass or more, and more preferably such that the purity of the undiluted solution has a purity of 99.9% by mass or more. The upper limit is preferably 99.9999% by mass or less.

[0112] Examples of purification methods include passing the raw material through an ion exchange resin or a reverse osmosis membrane (RO membrane), reprecipitation, distillation of the raw material, and filtering. A combination of the above purification methods may be used as the purification method. For example, the raw material may be subjected to primary purification by passing it through an RO membrane, and then subjected to secondary purification by passing it through a purification device consisting of a cation exchange resin, an anion exchange resin, or a mixed-bed ion exchange resin. Furthermore, the purification process may be performed multiple times.

[0113] The filter used for filtering is not particularly limited as long as it is one that has been conventionally used for filtering purposes. Examples include filters made of fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), polyamide resins such as nylon, polyallylsulfone (PAS), and polyolefin resins (including high-density or ultra-high molecular weight) such as polyethylene and polypropylene (PP). Among these materials, materials selected from the group consisting of polyethylene, polypropylene (including high-density polypropylene), fluororesins (including PTFE and PFA), and polyamide resins (including nylon) are preferred, and fluororesin filters are more preferred. Filtering raw materials using filters made of these materials can effectively remove highly polar foreign matter that is likely to cause defects.

[0114] <Container> The present cleaning agent (including the diluted cleaning agent and the undiluted cleaning agent described below) can be filled into any container for storage, transportation, and use, as long as corrosiveness and other issues do not pose a problem.

[0115] As a container, a container with a high degree of cleanliness within the container for semiconductor applications and suppressing the elution of impurities from the inner wall of the container's storage portion into each liquid is preferred. Examples of such containers include various containers commercially available as containers for semiconductor compositions, such as the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd., but are not limited to these. In addition, the containers exemplified in paragraphs

[0121] to

[0124] of WO 2022 / 004217 can also be used as containers, and the contents of these containers are incorporated herein.

[0116] The interior of these containers is preferably cleaned before filling with the cleaning agent. The liquid used for cleaning is preferably one that has a reduced amount of metal impurities. After production, the cleaning agent may be bottled in containers such as gallon bottles or coated bottles, and then transported and stored.

[0117] To prevent changes in the components of this cleaning agent during storage, the container may be filled with an inert gas (such as nitrogen or argon) with a purity of 99.99995% by volume or higher. Gases with low water content are particularly preferred. During transportation and storage, the cleaning agent may be stored at room temperature, or the temperature may be controlled within the range of -20°C to 20°C to prevent deterioration.

[0118] <Clean Room> The manufacturing of the cleaning agent, handling including opening and cleaning of the container, filling of the cleaning agent, processing analysis, and measurement are preferably all carried out in a clean room. The clean room preferably meets the 14644-1 clean room standard. It is preferable that the clean room meets any of ISO (International Organization for Standardization) Class 1, ISO Class 2, ISO Class 3, and ISO Class 4, more preferably ISO Class 1 or ISO Class 2, and even more preferably ISO Class 1.

[0119] [Dilution Step] The cleaning agent may be subjected to a dilution step in which it is diluted with a diluent such as a solvent, and then used for treating semiconductor substrates as the diluted cleaning agent (diluted cleaning agent). Note that both the undiluted cleaning agent (stock solution) and the diluted cleaning agent are forms of the cleaning agent of the present invention as long as they satisfy the requirements of the present invention.

[0120] In the dilution step, the diluent is preferably water (preferably ultrapure water). It is also preferable to subject the diluent to a purification treatment in advance. It is more preferable to subject the diluted cleaning agent obtained in the dilution step to a purification treatment. Examples of the purification treatment include a treatment to reduce ion components using an ion exchange resin or an RO membrane, or the like, and a treatment to remove foreign matter using filtering, as described above as a purification treatment for the cleaning agent. It is preferable to perform either of these treatments.

[0121] The dilution ratio in the dilution step may be adjusted appropriately depending on the type and content of each component, the concentration of each component in the cleaning agent before dilution, and the semiconductor substrate. The dilution ratio is preferably 10 to 10,000 times, more preferably 10 to 3,000 times, even more preferably 10 to 1,000 times, and particularly preferably 10 to 150 times, in terms of mass ratio or volume ratio (volume ratio at 23°C).

[0122] The change in pH before and after dilution (the difference between the pH of the undiluted cleaning agent and the pH of the diluted cleaning agent) is preferably 2.5 or less, more preferably 2.0 or less, and even more preferably 1.3 or less. The pH of the undiluted cleaning agent and the pH of the diluted cleaning agent are preferably in the preferred embodiments described above. The pH of the diluted cleaning agent may be adjusted using the pH adjuster described above.

[0123] The specific method for the dilution step of diluting the present cleaning agent may be similar to that for the above-mentioned solution preparation step of the present cleaning agent. The stirring device and stirring method used in the dilution step may also be similar to those used in the above-mentioned solution preparation step of the present cleaning agent.

[0124] [Uses] The present cleaning agent is used for cleaning semiconductor substrates in the semiconductor manufacturing process, and is particularly preferably used for cleaning semiconductor substrates that have been subjected to chemical mechanical polishing (CMP). The semiconductor substrate is often a semiconductor substrate containing metal, and a semiconductor substrate containing at least one of copper and ruthenium-containing substances is preferred. In other words, the present cleaning agent is preferably used for treating semiconductor substrates that have been subjected to CMP and contain at least one of copper and ruthenium-containing substances. As mentioned above, the present cleaning agent may be used as a diluted cleaning agent obtained by diluting the present cleaning agent.

[0125] [Metal-Containing Semiconductor Substrate] In a metal-containing semiconductor substrate, the metal may be located on any of the front and back surfaces, side surfaces, and grooves of the wafer. Furthermore, the metal-containing semiconductor substrate includes not only a case where the metal is directly located on the surface of the wafer, but also a case where the metal is located on the wafer via another layer.

[0126] Examples of the metal include at least one metal M selected from the group consisting of tungsten (W), molybdenum (Mo), copper (Cu), cobalt (Co), ruthenium (Ru), aluminum (Al), titanium (Ti), tantalum (Ta), chromium (Cr), hafnium (Hf), osmium (Os), platinum (Pt), nickel (Ni), manganese (Mn), iron (Fe), zirconium (Zr), palladium (Pd), lanthanum (La), niobium (Nb), and iridium (Ir). At least one metal selected from the group consisting of W, Mo, Cu, Co, and Ru is preferred, and at least one metal selected from Cu and Ru is more preferred.

[0127] The metal is preferably present as a metal layer containing the metal. Examples of the form of the metal contained in the metal layer include a simple substance of metal M and an alloy containing metal M. In particular, the semiconductor substrate preferably has a metal layer containing metal M, more preferably has a metal layer containing W, Mo, Cu, Co, or Ru, and further preferably has a metal layer containing Cu or Ru.

[0128] The Ru-containing material is not particularly limited as long as it contains Ru (Ru atoms), and examples thereof include simple Ru, Ru alloys, Ru oxides, Ru nitrides, and Ru oxynitrides. The Ru oxides, Ru nitrides, and Ru oxynitrides may also be Ru-containing composite oxides, composite nitrides, and composite oxynitrides. The content of Ru atoms in the Ru-containing material is preferably 10% by mass or more, more preferably 30% by mass or more, even more preferably 50% by mass or more, and particularly preferably 90% by mass or more, based on the total mass of the Ru-containing material. There is no particular upper limit, and the content is preferably 100% by mass or less, based on the total mass of the Ru-containing material.

[0129] The Ru-containing material may contain other transition metals, such as Rh (rhodium), Ti (titanium), Ta (tantalum), Co (cobalt), Cr (chromium), Hf (hafnium), Os (osmium), Pt (platinum), Ni (nickel), Mn (manganese), Cu (copper), Zr (zirconium), Mo (molybdenum), La (lanthanum), and Ir (iridium).

[0130] The semiconductor substrate may include, in addition to the metal layer described above, for example, a wafer, an insulating film, a metal wiring film, and a barrier metal.

[0131] Examples of wafers constituting semiconductor substrates include wafers made of silicon-based materials such as silicon (Si) wafers, silicon carbide (SiC) wafers, and silicon-containing resin wafers (glass epoxy wafers), as well as gallium phosphide (GaP) wafers, gallium arsenide (GaAs) wafers, and indium phosphide (InP) wafers. Examples of silicon wafers include n-type silicon wafers doped with pentavalent atoms (e.g., phosphorus (P), arsenic (As), and antimony (Sb)), and p-type silicon wafers doped with trivalent atoms (e.g., boron (B) and gallium (Ga)). Examples of silicon in silicon wafers include amorphous silicon, single crystal silicon, and polycrystalline silicon (polysilicon). Among these, wafers made of silicon-based materials such as silicon wafers, silicon carbide wafers, and silicon-containing resin wafers (glass epoxy wafers) are preferred.

[0132] The insulating film may be, for example, a silicon oxide film (e.g., silicon dioxide (SiO ２ ) film and tetraethyl orthosilicate (Si(OC ２ H ５ ) ４ ) film (TEOS film), silicon nitride film (e.g., silicon nitride (Si ３ N ４ ) and silicon carbide nitride (SiNC), etc.), and low dielectric constant (Low-k) films (for example, carbon-doped silicon oxide (SiOC) films, BD (black diamond) films, silicon carbide (SiC) films, etc.), with low dielectric constant (Low-k) films being preferred.

[0133] Examples of wiring metals include copper (Cu), copper-aluminum alloy (CuAl), copper-titanium alloy (CuTi), copper-chromium alloy (CuCr), copper-manganese alloy (CuMn), copper-tantalum alloy (CuTa), copper-niobium alloy (CuNb), copper-tungsten alloy (CuW), silver (Ag), and gold (Au).

[0134] Examples of barrier metals include tantalum (Ta), tantalum nitride (TaN), titanium nitride (TiN), cobalt (Co), cobalt alloys, ruthenium (Ru), and ruthenium alloys.

[0135] The method for forming the insulating film and the metal-containing film on the wafer constituting the semiconductor substrate is not particularly limited as long as it is a method commonly used in this field. For example, the insulating film may be formed by heat treating the wafer constituting the semiconductor substrate in the presence of oxygen gas to form a silicon oxide film, and then injecting silane and ammonia gas to form a silicon nitride film by chemical vapor deposition (CVD). For example, the metal-containing film may be formed by forming a circuit on the wafer having the insulating film by a known method such as resist, and then forming a metal layer by plating, physical vapor deposition (PVD), CVD, or the like.

[0136] <CMP Treatment> As mentioned above, the present cleaning agent is often used to clean semiconductor substrates that have undergone CMP treatment. CMP treatment is a process in which the surface of a substrate having a layer selected from, for example, a metal wiring film, a barrier metal, and an insulating film is planarized by a combined action of chemical and mechanical polishing using a polishing slurry containing abrasive particles (abrasive grains). Specifically, for example, the surface of the semiconductor substrate is brought into contact with a polishing pad, and the semiconductor substrate and the polishing pad are slid relative to each other while the polishing slurry is supplied to the contact area. As a result, components on the surface of the semiconductor substrate are removed and planarized by the frictional forces between the polishing pad, the polishing slurry, and the surface of the semiconductor substrate, and the chemical action of the polishing slurry. The polishing pad is not particularly limited, and pads commonly used in CMP treatments, such as nonwoven fabrics, polyurethane foams, and porous fluororesins, can be used. Residues such as metal impurities derived from the abrasive grains (e.g., silica and alumina) used in the CMP treatment, the polished metal wiring film, and / or the barrier metal may remain on the surface of a semiconductor substrate that has undergone CMP treatment. In addition, organic substances derived from the CMP composition used in the CMP treatment may remain as residues. These residues may, for example, cause short circuits between wirings and deteriorate the electrical properties of the semiconductor substrate. Therefore, the semiconductor substrate that has been subjected to the CMP treatment is subjected to a cleaning treatment to remove these residues from the surface.

[0137] This cleaning agent is preferably used for cleaning treatment after the above-mentioned CMP treatment. In particular, when the metal in the semiconductor substrate contains copper and ruthenium-containing substances, this cleaning agent can efficiently remove residues. Specific examples of semiconductor substrates that have been subjected to CMP treatment include, but are not limited to, substrates that have been subjected to CMP treatment described in Journal of the Japan Society for Precision Engineering, Vol. 84, No. 3, 2018.

[0138] <Pad Cleaning Treatment (Buff Cleaning Treatment)> After the CMP treatment, the surface of the semiconductor substrate may be subjected to a pad cleaning treatment (buff cleaning treatment). The pad cleaning treatment (buff cleaning treatment) is a treatment for reducing residues present on the surface of the semiconductor substrate using a pad. Specifically, the surface of the semiconductor substrate that has been subjected to the CMP treatment is brought into contact with a pad, and the semiconductor substrate and the pad are slid relative to each other while a pad composition is supplied to the contact portion. As a result, residues on the surface of the semiconductor substrate are removed by the frictional force of the pad and the chemical action of the pad composition. The pad composition refers to a composition (composition for pad cleaning treatment) used in the pad cleaning treatment (buff cleaning treatment).

[0139] The pad is not particularly limited and can be appropriately selected depending on the type of semiconductor substrate, the type of residue to be removed, and the equipment used. The pad may be a polishing pad used in CMP processing, or a buff pad such as a foam polyurethane buff pad, a nonwoven fabric, a suede buff pad, or a sponge. Pad cleaning processing using a pad includes processes called rinse polishing, buff cleaning, or buff polishing.

[0140] Known compositions can be used as the pad composition depending on the type of semiconductor substrate and the type and amount of residue to be removed. Examples of components contained in the pad composition include a water-soluble polymer such as polyvinyl alcohol, a dispersion medium such as water, an acid such as nitric acid, a basic compound such as an amine, a surfactant, an antibacterial agent, and a phosphonic acid compound. The pad composition does not contain abrasive particles. The pad composition preferably contains a surfactant, as this provides excellent residue removal. Examples of surfactants include those that may be contained in the above-mentioned compositions. Nonionic surfactants are preferred, ester-type nonionic surfactants are more preferred, and polyoxyethylene sorbitan fatty acid esters or sorbitan fatty acid esters are even more preferred. The content of the surfactant in the pad composition is preferably 0.01 to 20% by mass. The pad composition may be acidic, basic, or neutral, and is preferably acidic (more preferably pH 6 or less) or basic (more preferably pH 8 or more).

[0141] The apparatus and conditions used in the pad cleaning process can be appropriately selected from known apparatuses and conditions depending on the type of semiconductor substrate and the type and amount of residue to be removed. For example, the processing method described in paragraphs

[0085] to

[0088] of WO 2017 / 169539 can be used, the contents of which are incorporated herein by reference.

[0142] In one embodiment of the pad cleaning treatment, the present cleaning agent is preferably used as a pad composition to perform pad cleaning treatment on a semiconductor substrate. The composition used in the pad cleaning treatment may be a diluted composition.

[0143] The pad cleaning process may be performed only once or may be performed two or more times. For example, after the CMP process, the semiconductor substrate may be subjected to a pad cleaning process using a polishing pad and a pad cleaning process using a buff pad.

[0144] [Pad] The pad is not particularly limited as long as it is used in the processing of semiconductor substrates, but is preferably a pad (polishing pad) used in CMP processing. After CMP processing, the polishing pad used in CMP processing may have residues attached thereto, such as abrasive grains used in CMP processing, metal impurities derived from the polished metal wiring film and barrier metal, and organic matter derived from the CMP composition. If the next CMP processing of a semiconductor substrate is performed with these residues attached to the polishing pad, defects such as polishing scratches and residue adhesion may occur on the semiconductor substrate surface. Therefore, it is preferable that the polishing pad be cleaned after or before CMP processing. The composition is also preferably used as a cleaning solution for cleaning the polishing pad used in the CMP processing. The composition used in the pad cleaning processing may be a diluted composition.

[0145] [Method for Manufacturing Cleaned Semiconductor Substrates] As described above, the present cleaning agent is a cleaning agent for semiconductor substrates. Examples of methods for using the present cleaning agent include a method for manufacturing cleaned semiconductor substrates, which includes a step of contacting a semiconductor substrate that has been subjected to chemical mechanical polishing with the present cleaning agent. Hereinafter, the step of contacting a semiconductor substrate with the present cleaning agent is also referred to as a "contact step." The semiconductor substrate is as described above and may be, for example, a semiconductor substrate containing a metal. The method for contacting a semiconductor substrate with the present cleaning agent is not particularly limited, and examples include a method of immersing a semiconductor substrate in the present cleaning agent placed in a tank, a method of spraying the present cleaning agent onto a semiconductor substrate, a method of pouring the present cleaning agent onto a semiconductor substrate, and combinations thereof. The above method may be appropriately selected depending on the purpose. The contact of a semiconductor substrate with the present cleaning agent in the contact step may be performed only once or may be performed two or more times. When performing the contact two or more times, the same method may be repeated, or different methods may be combined.

[0146] The pH of the present cleaning agent and the pH of the diluted cleaning agent are preferably the preferred pH values ​​described above. The temperature of the present cleaning agent is not particularly limited, but is preferably 10 to 60°C, more preferably 15 to 50°C, from the viewpoints of superior cleaning performance and suppression of damage to components. The contact time between the semiconductor substrate and the present cleaning agent can be appropriately changed depending on the type and content of each component contained in the present cleaning agent and the intended use and purpose of the present cleaning agent, but is preferably 10 to 120 seconds, more preferably 20 to 90 seconds, and even more preferably 30 to 60 seconds. The supply amount (supply rate) of the present cleaning agent is preferably 50 to 5,000 mL / min, more preferably 500 to 2,000 mL / min.

[0147] The semiconductor substrate may be treated using any method commonly used in this field. For example, scrubbing may be performed to remove residues by physically contacting a cleaning member such as a brush with the surface of the semiconductor substrate while supplying the cleaning agent, or a spin (drop) method may be used to drop the cleaning agent onto the rotating semiconductor substrate. In the immersion method, ultrasonic treatment is preferably performed on the semiconductor substrate immersed in the cleaning agent, as this method can further reduce impurities remaining on the surface of the semiconductor substrate.

[0148] The semiconductor substrate processing method may be either a single wafer processing method or a batch processing method. The single wafer processing method is a method in which semiconductor substrates are processed one by one, while the batch processing method is a method in which multiple semiconductor substrates are processed simultaneously.

[0149] For the treatment of the pad, a method generally used in this field may be appropriately adopted, for example, a method in which the pad is brought into contact with and slid over an object that is not polished by the pad while supplying the cleaning agent.

[0150] In the contacting step, mechanical stirring may be used to enhance the cleaning ability of the cleaning agent, such as circulating the cleaning agent over the semiconductor substrate, flowing or spraying the cleaning agent over the semiconductor substrate, or stirring the cleaning agent with ultrasonic waves or megasonics.

[0151] The treatment step is preferably a cleaning step in which residues on the surface of a semiconductor substrate are removed by contacting the semiconductor substrate with the cleaning agent.

[0152] Furthermore, after the contacting step, a step of contacting the semiconductor substrate with a rinse liquid (hereinafter also referred to as a "rinsing step") may be carried out. By carrying out the rinsing step, the semiconductor substrate obtained in the contacting step can be washed with the rinse liquid, and residues can be efficiently removed. The rinsing step is preferably carried out consecutively after the semiconductor substrate cleaning step, and is a step of rinsing the semiconductor substrate with the rinse liquid. The rinsing step may be carried out using the mechanical stirring method described above.

[0153] Examples of rinse solutions include water (preferably DI water), methanol, ethanol, isopropyl alcohol (IPA), N-methylpyrrolidinone, γ-butyrolactone, dimethyl sulfoxide, ethyl lactate, and propylene glycol monomethyl ether acetate. Aqueous rinse solutions having a pH greater than 8.0 (such as diluted aqueous ammonium hydroxide) may also be used.

[0154] The method of contacting the rinse solution with the semiconductor substrate can be the same as the method of contacting the present cleaning agent with the semiconductor substrate. The contact time between the semiconductor substrate and the rinse solution can be appropriately changed depending on the type and content of each component contained in the present cleaning agent, and the target and purpose of use of the present cleaning agent. Practically, the contact time is preferably 10 to 120 seconds, more preferably 20 to 90 seconds, and even more preferably 30 to 60 seconds.

[0155] After the contacting step and / or the rinsing step, a drying step may be performed to dry the semiconductor substrate. Examples of the drying method include spin drying, a method of passing a dry gas over the semiconductor substrate, a method of heating the substrate with a heating means such as a hot plate or an infrared lamp, Marangoni drying, Rotagoni drying, IPA drying, and any combination thereof.

[0156] [Method for Manufacturing Electronic Devices] The method for manufacturing the cleaned semiconductor substrate described above can be suitably applied to the manufacturing process of electronic devices. The manufacturing method described above may be performed before or after other processes performed on the substrate. Other processes may be incorporated into the manufacturing method described above, or the processing method described above may be incorporated into other processes. Examples of other processes include processes for forming structures such as metal wiring, gate structures, source structures, drain structures, insulating films, ferromagnetic layers, and non-magnetic layers (e.g., layer formation, etching, chemical mechanical polishing, and modification), resist formation processes, exposure processes, removal processes, heat treatment processes, cleaning processes, and inspection processes.

[0157] The above manufacturing method may be performed at any stage of a back end process (BEOL: Back end of the line), a middle process (MOL: Middle of the line), or a front end process (FEOL: Front end of the line), and is preferably performed in a front end process or a middle process.

[0158] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, treatment details, and treatment procedures shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

[0159] In the following examples, the pH of the cleaning agents was measured at 25°C using a pH meter (Horiba, Ltd., Model "F-74") in accordance with JIS Z8802-1984. In producing the cleaning agents in the examples and comparative examples, handling of containers, preparation, filling, storage and analytical measurements of the cleaning agents were all carried out in a clean room, and the containers used for preparation, filling, storage etc. of the cleaning agents were washed with the solvent used in the preparation or the prepared cleaning agent before use.

[0160] [Cleaning Agent Raw Materials] The following compounds were used to produce the cleaning agents. All components used in the Examples and Comparative Examples were semiconductor-grade or equivalent high-purity grade. Each component was dissolved in pure water to prepare a stock solution outside the clean room, and each stock solution was used to prepare the cleaning agents.

[0161] [Purine compounds] Adenine, Xanthine, Uric acid, Adenosine, Guanine, Hypoxanthine, Caffeine, Theobromine, Theophylline

[0162] [Specific polymers] Polyglycerin (PGLXPW (Mw=3000), manufactured by Daicel Corporation) Polyvinyl alcohol (22225 (Mw=6000), manufactured by Polyscience) Hydroxyethyl cellulose (434965, manufactured by Merck) Methyl cellulose (Metolose SM-4, manufactured by Shin-Etsu Chemical Co., Ltd.) Hydroxypropyl cellulose (Metolose SH60-03, manufactured by Shin-Etsu Chemical Co., Ltd.) Polyethyleneimine (164-17821 (Mw=10000), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0163] [Comparative polymer] Polyethylene glycol (165-09105 (Mw=2000), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0164] [Anionic polymer] Polyacrylic acid (Aron A-10SL (Mw=6000), manufactured by Toagosei Co., Ltd.) Acrylic acid-sulfonic acid monomer copolymer (Aqualic GL-366 (Mw=6000), manufactured by Nippon Shokubai Co., Ltd.)

[0165] [Specific amine compounds] Ethyltrimethylammonium hydroxide 2-(dimethylamino)-2-methyl-1-propanol N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDETA) N-methyldiethanolamine

[0166] [Other additives] Tartaric acid

[0167] [Production of Cleaning Agent] Each cleaning agent in the Examples and Comparative Examples was prepared according to the following procedure. First, a stock solution was obtained by adding each of the above components in an amount corresponding to the content (mass %) shown in the table below relative to the total mass of the stock solution and thoroughly stirring. The remainder, other than the components shown in Table 1 and the pH adjuster described below used in producing the stock solution, was water. A pH adjuster (hydrochloric acid or sodium hydroxide) was added to the obtained stock solution appropriately so that the pH after dilution with water would be the value shown in the table, and then the solution was diluted 100 times with water to obtain the cleaning agent of each Example and Comparative Example. The content of the pH adjuster was 1 mass % or less relative to the total mass of the stock solution. In the cleaning agents, the remainder (other than the components clearly shown in the table as components of the cleaning agent) was pure water.

[0168] [Evaluation] The cleaning agents produced by the above methods were evaluated for their corrosion prevention properties against copper and their ability to remove ruthenium-containing substances according to the following procedures.

[0169] [Corrosion Prevention (Corrosion Inhibition)] The cleaning agent produced by the above method was used to evaluate its corrosion prevention (corrosion inhibition) against copper (Cu) according to the following procedure. A silicon wafer having a 1000 nm thick Cu layer on one surface was cut into 2 cm squares to prepare 2 × 2 cm Cu wafers. The wafers were placed in a container filled with the cleaning agent of each Example or Comparative Example and immersed at room temperature (25°C) for 20 minutes. The Cu content in the immersed cleaning agent was then measured using an Agilent 8800 triple quadrupole ICP-MS (for semiconductor analysis, option #200) to determine the etching rate (Å / min). The corrosion prevention was evaluated from the etching rate according to the following evaluation criteria. The lower the etching rate, the more metal corrosion was suppressed and the better the corrosion prevention. The corrosion prevention is preferably rated C or higher.

[0170] A: Less than 0.5 Å / min B: 0.5 Å / min or more and less than 0.75 Å / min C: 0.75 Å / min or more and less than 1.0 Å / min D: 1.0 Å / min or more

[0171] [Removability (cleaning ability)] Using the cleaning agent produced by the above method, the removability (cleaning ability) of ruthenium-containing substances was evaluated according to the following procedure. Cu wafers prepared in the same manner as in the evaluation of [Corrosion prevention (corrosion suppression)] above were placed in a container filled with a potassium hydroxide aqueous solution (0.1 mass%) containing 0.1 mass% ruthenium oxide nanoparticles (NRE-3050, Nano Research Elements), and immersed for 30 minutes at room temperature (25°C). Thereafter, each wafer after immersion was rinsed with ultrapure water and further dried by spraying nitrogen gas, thereby preparing Ru-treated wafers.

[0172] Each of the Ru-treated wafers was placed in a container filled with the cleaning agent of each Example or Comparative Example and immersed in the container for 30 seconds at room temperature (25°C) for cleaning. Subsequently, each of the cleaned wafers was rinsed with ultrapure water and dried by spraying nitrogen gas. The amount of Ru-containing material remaining on each wafer was measured using secondary ion mass spectrometry (SIMS 5, ION-TOF, Inc.), and this amount was recorded as the "Ru remaining amount after cleaning." The amount of Ru-containing material remaining on each of the Ru-treated wafers that had not been cleaned was also measured using the same procedure as above, and this amount was recorded as the "Ru remaining amount before cleaning." The Ru reduction rate (%) was calculated from the "Ru remaining amount after cleaning" and the "Ru remaining amount before cleaning" measured using the procedure above, according to the following formula: Ru reduction rate (%) = 100 × (Ru remaining amount before cleaning - Ru remaining amount after cleaning) / Ru remaining amount before cleaning. From the obtained Ru reduction rate, removability was evaluated according to the following evaluation criteria. The larger the Ru reduction rate, the more Ru-containing substances are removed by the cleaning agent, and the better the removability. The removability is preferably rated C or higher.

[0173] A: 80% or more B: 50% or more, less than 80% C: 20% or more, less than 50% D: Less than 20%

[0174] [Results] Table 1 shows the composition of each cleaning agent in the Examples and Comparative Examples, and the evaluation results. In the table, the "Content (mass %)" column for each component indicates the content (mass %) of each component relative to the total mass of the stock solution. In the table, the "Specific polymer / purine compound" column indicates the mass ratio of the content of the specific polymer to the content of the purine compound. In the table, the value in the "pH after dilution" column indicates the pH of the cleaning agent at 25°C, measured using the pH meter described above. The value in the "pH after dilution" column is the value measured for a cleaning agent prepared by diluting the stock solution.

[0175]

[0176]

[0177] The results in the above table confirm that the cleaning agents of the present invention (cleaning agents of the Examples) are excellent in corrosion prevention against copper and in removal of ruthenium-containing substances. On the other hand, the results of the Comparative Examples confirm that the cleaning agents that do not satisfy the requirements of the present invention do not satisfy the desired levels in at least one of excellent corrosion prevention against copper and removal of ruthenium-containing substances.

[0178] Comparisons of Examples 1 to 3 and the like confirmed that when the mass ratio of the content of the specific polymer to the content of the purine compound was 100.0 or less, the corrosion resistance against copper was superior. Comparisons of Examples 4 to 6 and the like confirmed that when the mass ratio of the content of the specific polymer to the content of the purine compound was 0.01 or more, the removal ability of ruthenium-containing substances was superior. Comparisons of Examples 10 to 14 and the like confirmed that when the specific polymer was a nonionic polymer, the removal ability of ruthenium-containing substances was superior. Comparisons of Examples 1, 4, and 17 to 23 and the like confirmed that when the purine compound was a compound selected from adenine, adenosine, guanine, xanthine, uric acid, and derivatives thereof, the corrosion resistance against copper was superior, and when the purine compound was a compound selected from adenine, adenosine, guanine, xanthine, and derivatives thereof, the corrosion resistance against copper was even superior. Comparison between Examples 20 and 24 etc. confirmed that when the pH of the cleaning solution was 10.0 or higher, the removal of ruthenium-containing substances was superior.

Claims

1. A cleaning agent for semiconductor substrates, which is alkaline and contains a purine compound selected from purines and purine derivatives, and a specific polymer having a repeating unit having a hydroxyl group and / or a cationic group.

2. The cleaning agent for semiconductor substrates according to claim 1, wherein the purine compound is a compound represented by any one of formulas (A) to (D). In formula (A), R １ and R ２ each independently represents a hydrogen atom or a specific substituent selected from an alkyl group which may have a substituent, an amino group which may have a substituent, a thiol group, a hydroxyl group, a halogen atom, a sugar group which may have a substituent, and a polyoxyalkylene group-containing group which may have a substituent. １ and R ２ In formula (B), at least one of R represents the specific substituent. ３ ~R ５ each independently represents a hydrogen atom or the specific substituent. ３ ~R ５ In formula (C), at least two of R represent a hydrogen atom. ６ ~R ８ each independently represents a hydrogen atom or the specific substituent. ６ ~R ８ In formula (D), at least two of R represent a hydrogen atom. ９ ~R １２ each independently represents a hydrogen atom or the specific substituent. ９ ~R １２ At least two of the groups represent hydrogen atoms.

3. The cleaning agent for semiconductor substrates according to claim 1, wherein the purine compound is a compound selected from the group consisting of adenine, adenosine, guanine, xanthine, uric acid, and derivatives thereof.

4. The cleaning agent for semiconductor substrates according to claim 1, wherein the specific polymer is a nonionic polymer.

5. The cleaning agent for semiconductor substrates according to claim 1, wherein the repeating unit having a hydroxyl group is a repeating unit represented by formula (1). In formula (1), L １ represents a single bond or a divalent linking group. ２ is a single bond, a methylene group, or —CH ２ Represents O-.

6. The cleaning agent for semiconductor substrates according to claim 1, wherein the repeating unit having a hydroxyl group is a repeating unit having a hydroxyl group and a cyclic structure.

7. The cleaning agent for semiconductor substrates according to claim 1, wherein the repeating unit having a hydroxyl group is a repeating unit represented by formula (2). In formula (2), each R independently represents a hydrogen atom or an alkyl group which may have a hydroxyl group, provided that at least one of the multiple Rs represents a hydrogen atom or an alkyl group which has a hydroxyl group.

8. The cleaning agent for semiconductor substrates according to claim 1, wherein the mass ratio of the content of the specific polymer to the content of the purine compound is 0.01 to 100.

0.

9. The cleaning agent for semiconductor substrates according to claim 1, further comprising a specific amine compound selected from quaternary ammonium compounds and tertiary amine compounds.

10. The cleaning agent for semiconductor substrates according to claim 1, further comprising a polymer having an anionic group.

11. The cleaning agent for semiconductor substrates according to claim 1, having a pH of 10.0 or higher.

12. The cleaning agent for semiconductor substrates according to claim 1, which is used after being diluted with a solvent.

13. The cleaning agent for semiconductor substrates according to claim 1, which is used for cleaning semiconductor substrates that have been subjected to chemical mechanical polishing.

14. The cleaning agent for semiconductor substrates according to claim 13, wherein the semiconductor substrate comprises copper and ruthenium-containing materials.

15. A method for producing a cleaned semiconductor substrate, comprising a step of contacting a semiconductor substrate that has been subjected to chemical mechanical polishing treatment with the cleaning agent for semiconductor substrates according to any one of claims 1 to 14.

16. A method for manufacturing an electronic device, comprising the method for manufacturing a cleaned semiconductor substrate according to claim 15.

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