Cleaning solution for semiconductor substrates

Abstract

The present invention addresses the problem of providing a semiconductor substrate cleaning solution that has excellent cleaning performance and excellent ruthenium oxide dissolution performance when used as a cleaning solution after CMP treatment of a semiconductor substrate containing a metal film. The semiconductor substrate cleaning solution of the present invention is used for cleaning a semiconductor substrate and contains a compound represented by formula (A) and at least one purine compound selected from the group consisting of purine and purine derivatives.

Description

[Technical Field]

[0001] The present invention relates to a cleaning solution for semiconductor substrates. [Background technology]

[0002] Semiconductor elements such as CCDs (Charge-Coupled Devices) and memories are manufactured by forming fine electronic circuit patterns on a substrate using photolithography technology. Specifically, a resist film is formed on a laminate having a metal film, which serves as the wiring material, an etching stop layer, and an interlayer insulating layer on a substrate, and then photolithography and dry etching processes (e.g., plasma etching) are performed to manufacture the semiconductor elements.

[0003] In the manufacture of semiconductor devices, chemical mechanical polishing (CMP) is often performed to planarize the surface of a semiconductor substrate 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 CMP, metal components derived from the abrasive particles used in CMP, the polished wiring metal film, and / or the barrier metal, etc., tend to remain on the surface of the semiconductor substrate after polishing. These residues can cause short circuits between wirings and affect the electrical properties of semiconductors, so a cleaning process is generally carried out to remove these residues from the surface of the semiconductor substrate.

[0004] As a cleaning solution used in the cleaning step, for example, Patent Document 1 discloses a cleaning composition comprising "at least one solvent, at least one corrosion inhibitor, at least one amine, and at least one quaternary base, wherein the corrosion inhibitor comprises one selected from the group consisting of ribosyl purine and its methylated or deoxy derivative, adenosine and decomposition products of adenosine derivatives, purine-sugar complexes, methylated or deoxy purine derivatives and their reaction products or decomposition products, and combinations thereof." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2016-074906 Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors have studied the semiconductor substrate cleaning solution described in Patent Document 1 and have found that there is room for improvement in both cleaning performance and ruthenium oxide dissolving ability of a semiconductor substrate cleaning solution used for semiconductor substrates that have been subjected to CMP and that contain a metal film (particularly ruthenium metal). The cleaning performance is a performance that indicates the degree to which, when a semiconductor substrate containing a metal film (particularly ruthenium metal) is subjected to CMP processing using a polishing liquid and then subjected to a cleaning process using a semiconductor substrate cleaning liquid, organic residues and the like derived from the polishing liquid used in the CMP processing and the semiconductor substrate (e.g., an insulating film) are unlikely to remain on the semiconductor substrate even after the cleaning process. In other words, excellent cleaning performance means that organic residues and the like are unlikely to remain on the semiconductor substrate. Furthermore, when a semiconductor substrate containing a metal film (particularly ruthenium metal) is subjected to CMP processing using a polishing liquid, the metal (particularly ruthenium metal) constituting the metal film may be oxidized to produce a metal oxide (particularly ruthenium oxide). Ruthenium oxide dissolving ability is a performance that indicates the degree to which the metal oxide (particularly ruthenium metal) is unlikely to remain on the semiconductor substrate even after the cleaning process (ease of dissolving). In other words, excellent ruthenium oxide dissolving ability means that ruthenium oxide on the semiconductor substrate is easily dissolved, and therefore ruthenium oxide is unlikely to remain on the semiconductor substrate.

[0007] An object of the present invention is to provide a cleaning liquid for semiconductor substrates that, when used as a cleaning liquid after CMP processing of semiconductor substrates containing a metal film (particularly ruthenium metal), has excellent cleaning performance and also excellent ruthenium oxide dissolving ability. [Means for solving the problem]

[0008] The present inventors have found that the above problems can be solved by the following configuration.

[0009] [1] A semiconductor substrate cleaning solution used for cleaning a semiconductor substrate, A cleaning solution for semiconductor substrates, comprising at least one purine compound selected from the group consisting of purine and purine derivatives, and a compound represented by formula (A) described below. [2] The cleaning solution for semiconductor substrates according to [1], wherein the purine compound comprises at least one selected from the group consisting of compounds represented by formulas (B5) to (B6) described below. [3] The cleaning solution for semiconductor substrates according to [1], wherein the purine compound comprises at least one selected from the group consisting of xanthine, adenine, guanine, hypoxanthine, uric acid, purine, caffeine, isoguanine, theobromine, theophylline, and paraxanthine. [4] The cleaning solution for semiconductor substrates according to any one of [1] to [3], wherein the purine compound comprises at least one selected from the group consisting of xanthine and hypoxanthine. [5] The cleaning solution for semiconductor substrates according to any one of [1] to [4], wherein the compound represented by formula (A) includes a compound represented by formula (A1) described below. [6] The cleaning solution for semiconductor substrates according to any one of [1] to [5], wherein the compound represented by the formula (A) includes N-methyldiethanolamine. [7] The cleaning solution for semiconductor substrates according to any one of [1] to [6], wherein the content of the purine compound is 0.5 to 30.0 mass % relative to the total mass of the components of the cleaning solution for semiconductor substrates excluding the solvent. [8] The cleaning solution for semiconductor substrates according to any one of [1] to [7], wherein the content of the compound represented by the formula (A) is 3.0 to 40.0 mass % relative to the total mass of the components excluding the solvent from the cleaning solution for semiconductor substrates. [9] The cleaning solution for semiconductor substrates according to any one of [1] to [8], wherein the mass ratio of the content of the purine compound to the content of the compound represented by formula (A) is 0.02 to 20.0.

[10] The cleaning solution for semiconductor substrates according to any one of [1] to [9], which has a pH of 9.5 to 13.0.

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

[10] , further comprising an organic acid.

[12] The cleaning solution for semiconductor substrates according to

[11] , wherein the organic acid contains a compound represented by formula (D) described below.

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

[12] , further comprising a quaternary ammonium compound.

[14] The cleaning solution for semiconductor substrates according to

[13] , wherein the quaternary ammonium compound includes a compound represented by formula (C) described below.

[15] The cleaning solution for semiconductor substrates according to

[13] or

[14] , wherein the quaternary ammonium compound contains tris(2-hydroxyethyl)methylammonium hydroxide.

[16] The cleaning solution for semiconductor substrates according to any one of [1] to

[15] , further comprising an aliphatic tertiary amine compound which is a compound different from the compound represented by formula (A).

[17] The cleaning solution for semiconductor substrates according to

[16] , wherein the aliphatic tertiary amine compound has two or more nitrogen atoms. [Effects of the Invention]

[0010] According to the present invention, a cleaning liquid for semiconductor substrates can be provided that, when used as a cleaning liquid after CMP of semiconductor substrates containing metal films (particularly ruthenium metal), has excellent cleaning performance and also excellent ability to dissolve ruthenium oxide. DETAILED DESCRIPTION OF THE INVENTION

[0011] An example of an embodiment of the present invention will be described below. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0012] In this specification, when two or more types of a component are present, the "content" of that component means the total content of those two or more components. In this specification, "ppm" means "parts-per-million (10 -6 ) and "ppb" means "parts-per-billion (10 -9 )" Unless otherwise specified, the compounds described herein may include isomers (compounds with the same number of atoms but different structures), optical isomers, and isotopes. Furthermore, only one type of isomer or isotope may be included, or multiple types may be included. In this specification, the bonding direction of a divalent group (e.g., -COO-) is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "XYZ," the compound may be "XO-CO-Z" or "X-CO-OZ."

[0013] As used herein, "psi" means pound-force per square inch, with 1 psi = 6894.76 Pa. 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).

[0014] In this specification, the "total mass of components in the cleaning solution excluding the solvent" means the total content of all components contained in the cleaning solution other than the solvent, such as water and organic solvent.

[0015] [Cleaning solution for semiconductor substrates (cleaning solution)] The cleaning solution for semiconductor substrates of the present invention (hereinafter also simply referred to as "cleaning solution") is a cleaning solution for semiconductor substrates used for cleaning semiconductor substrates, and contains at least one purine compound selected from the group consisting of purines and purine derivatives (hereinafter also simply referred to as "purine compound"), and a compound represented by formula (A) (hereinafter also referred to as "compound A").

[0016] The mechanism by which the above-mentioned configuration solves the problems of the present invention is not entirely clear, but it is thought that the coexistence of a purine compound and compound A causes the components to act cooperatively, resulting in excellent cleaning performance and excellent ability to dissolve ruthenium oxide. For example, it is presumed that the purine compound and compound A interact with the residues on the semiconductor substrate surface after CMP processing and with the substrate surface, thereby contributing to improved cleaning performance and improved ruthenium oxide dissolving ability. Hereinafter, when at least one of the cleaning performance and the ability to dissolve ruthenium oxide is superior, it is also referred to as when the effect of the present invention is superior. Each component contained in the cleaning solution will be described below.

[0017] [Compound A] The cleaning solution contains compound A (a compound represented by formula (A)).

[0018] [ka]

[0019] In formula (A), R a1 represents an alkyl group which may have a hydroxyl group. a2 represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent.a3 represents an alkylene group which may have an oxygen atom.

[0020] R a1 represents an alkyl group which may have a hydroxyl group. The alkyl group may be linear, branched, or cyclic. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, further preferably 1 to 3 carbon atoms, and particularly preferably 2 carbon atoms. The number of hydroxyl groups in the alkyl group is preferably 1 to 5, more preferably 1 to 3, still more preferably 1 or 2, and particularly preferably 1.

[0021] R a2 represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent. Examples of the substituent on the alkyl group include halogen atoms such as fluorine atom, chlorine atom, and bromine atom; alkoxy groups; hydroxyl groups; carboxy groups; alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group; acyl groups such as acetyl group, propionyl group, and benzoyl group; cyano groups; nitro groups; and amino groups. Of these, hydroxyl groups, carboxy groups, and amino groups are preferred, and hydroxyl groups are more preferred. Among them, R a2 is preferably a hydrogen atom, an alkyl group which may have a hydroxyl group, or an aryl group which may have a substituent, more preferably a hydrogen atom, an unsubstituted alkyl group having 1 to 3 carbon atoms, or an aryl group which may have a substituent, further preferably a hydrogen atom, a methyl group, an ethyl group, a tert-butyl group, or a phenyl group, and particularly preferably a methyl group.

[0022] The alkyl group may be linear, branched, or cyclic. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, further preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. When the alkyl group has a hydroxyl group, the number of hydroxyl groups that the alkyl group has is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1.

[0023] The aryl group may be either monocyclic or polycyclic. The aryl group preferably has 6 to 20 carbon atoms, more preferably 6 to 10 carbon atoms, and even more preferably 6 to 8 carbon atoms. Examples of the substituent on the aryl group include a halogen atom such as a chlorine atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a nitro group, a thiol group, a hydroxyl group, a carboxy group, an amino group, and a dioxiranyl group. Of these, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a carboxy group, and an amino group are preferred, an alkyl group having 1 to 10 carbon atoms is more preferred, and an alkyl group having 1 to 3 carbon atoms is even more preferred. The number of substituents on the aryl group is preferably 1 to 5, more preferably 1 to 3, and still more preferably 1. Examples of the aryl group include a benzyl group, a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenabutenyl group, a fluorenyl group, and a pyrenyl group. A benzyl group or a phenyl group is preferred, and a phenyl group is more preferred.

[0024] R a3 represents an alkylene group which may have an oxygen atom. The alkylene group may be either linear or branched. The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. The alkylene group preferably has 1 to 5 oxygen atoms, more preferably 1 to 3 oxygen atoms, and even more preferably 1 or 2 oxygen atoms. Examples of the alkylene group include an alkylene group, an oxyalkylene group, and an alkylene group having a hydroxyl group. An alkylene group or oxyalkylene group having 1 to 10 carbon atoms is preferred, an alkylene group having 1 to 10 carbon atoms is more preferred, and an alkylene group having 1 to 3 carbon atoms is even more preferred.

[0025] Compound A is preferably a compound represented by formula (A1).

[0026] [ka]

[0027] In formula (A1), R a4 represents an alkylene group which may have an oxygen atom. a6 represents an alkylene group. a5 represents an alkyl group having 1 to 5 carbon atoms which may have a substituent, a phenyl group, or a hydrogen atom.

[0028] R a4 is R in the above formula (A). a3 The same definition and preferred embodiments are also the same. R a6 The alkylene group represented by the formula (I) may be linear, branched or cyclic. The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, further preferably 1 to 3 carbon atoms, and particularly preferably 2 carbon atoms. R a5 As the group, an alkyl group having 1 to 3 carbon atoms, a tert-butyl group or a phenyl group is preferred, and a methyl group is more preferred. The alkyl group may be linear, branched, or cyclic. The substituents include R in formula (A). a2 Examples of the substituents include those possessed by the following groups:

[0029] Examples of compound A include N-methylethanolamine (N-MEA), N-methyldiethanolamine (MDEA), 2-(dimethylamino)ethanol (DMAE), 2-(ethylamino)ethanol, 2-[(hydroxymethyl)amino]ethanol, 2-(propylamino)ethanol, N,N-dimethylaminoethoxyethanol, diethanolamine, 2-diethylaminoethanol, N-butylethanolamine, N-ethyldiethanolamine (EDEA), 2-[2-(dimethylamino)ethoxy]ethanol, N-cyclohexylethanolamine, triethanolamine, N-butyldiethanolamine (BDEA), 2-[2-(diethylamino) [ethoxy]ethanol, 2-(dimethylamino)-2-methyl-1-propanol (DMAMP), (2-methyl-2(methylamino)propan-1-ol (MAMP), N-tert-butyldiethanolamine (t-BDEA), 1-[bis(2-hydroxyethyl)amino]-2-propanol (Bis-HEAP), 2-(N-ethylanilino)ethanol, 2-(dibutylamino)ethanol, N-phenyldiethanolamine (Ph-DEA), N-benzyldiethanolamine, p-tolyldiethanolamine, m-tolyldiethanolamine, N,N-bis(2-hydroxyethyl)-3-chloroaniline, and stearyldiethanolamine. Among these, compound A preferably contains at least one selected from the group consisting of DMAMP, MAMP, MDEA, t-BDEA, Bis-HEAP, Ph-DEA, EDEA, BDEA, N-MEA, and DMAE, and from the viewpoint of more excellent ruthenium oxide dissolving ability, it is more preferable that compound A contains at least one selected from the group consisting of MDEA, t-BDEA, Ph-DEA, EDEA, and N-MEA, and it is even more preferable that compound A contains MDEA.

[0030] The compound A may be used alone or in combination of two or more. The content of compound A is preferably from 0.05 to 20.0% by mass, more preferably from 0.2 to 10.0% by mass, and even more preferably from 0.3 to 4.0% by mass, based on the total mass of the cleaning liquid. The content of compound A is preferably 1.0 to 80.0 mass %, more preferably 2.0 to 60.0 mass %, and even more preferably 3.0 to 40.0 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0031] When the cleaning solution does not contain a quaternary ammonium compound described below, it is preferable that the cleaning solution contain compound A as a main component, since this provides superior effects of the present invention. In this case, compound A can also achieve the effects of the present invention provided by the quaternary ammonium compound. In other words, compound A contained as a main component also has the functions of a quaternary ammonium compound, and can provide effects similar to those obtained when a quaternary ammonium compound is contained. The term "main component" refers to a component that accounts for 50% by mass or more, preferably 60% by mass or more, of the total mass of the components in the cleaning solution excluding the solvent. The upper limit is often less than 100% by mass. The compound A contained as the main component is preferably 2-(dimethylamino)-2-methyl-1-propanol.

[0032] [Purine compounds] The washing solution contains at least one purine compound selected from the group consisting of purines and purine derivatives. The purine compound preferably includes at least one selected from the group consisting of compounds represented by formulas (B1) to (B4), more preferably includes at least one selected from the group consisting of compounds represented by formula (B1) and compounds represented by formulas (B4) to (B7), and even more preferably includes at least one selected from the group consisting of compounds represented by formulas (B5) to (B6).

[0033] [ka]

[0034] In formula (B1), R 1 ~R 3each independently represents a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent.

[0035] The alkyl group may be linear, branched, or cyclic. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms.

[0036] Examples of the sugar group include groups in which one hydrogen atom has been removed from a sugar selected from the group consisting of monosaccharides, disaccharides, and polysaccharides, and groups in which one hydrogen atom has been removed from a monosaccharide are 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. Disaccharides include, for example, sucrose, lactose, maltose, trehalose, turanose, and cellobiose. Polysaccharides include, for example, glycogen, starch and cellulose. The saccharide may be either linear or cyclic, and is preferably cyclic. Examples of the cyclic saccharides include a furanose ring and a pyranose ring.

[0037] The polyoxyalkylene group-containing group which may have a substituent means a group which has 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, with a polyoxyethylene group being preferred. Furthermore, the polyoxyalkylene group is preferably a group represented by the formula (E1) described below.

[0038] Examples of the substituents possessed by the alkyl group, the amino group, the sugar group, and the polyoxyalkylene group-containing group include hydrocarbon groups such as alkyl 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.

[0039] R 1 is preferably a hydrogen atom or an amino group which may have a substituent, and more preferably a hydrogen atom. R 1 Another preferred embodiment of is a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent. R 2 is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably a hydrogen atom. R 3 is preferably a hydrogen atom, an optionally substituted alkyl group or an optionally substituted sugar group, more preferably a hydrogen atom or an optionally substituted alkyl group, and even more preferably a hydrogen atom.

[0040] In formula (B2), L 1 -CR 6 =N- or -C(=O)-NR 7 - represents L 2 is -N=CH- or -NR 8 -C(=O)-. R 4 ~R 8 each independently represents a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent.

[0041] R 4 ~R 8 Examples of the R 1 ~R 3 Examples of the group include a group represented by the following formula: R 4 ~R 5 is preferably a hydrogen atom or an alkyl group which may have a substituent, more preferably a hydrogen atom. R 6 is preferably a hydrogen atom, an optionally substituted alkyl group or an optionally substituted amino group, more preferably a hydrogen atom or an optionally substituted amino group, and even more preferably a hydrogen atom. R 7 is preferably a hydrogen atom or an alkyl group which may have a substituent, more preferably a hydrogen atom. L 2 As the group, -N=CH- is preferred. R 8 is preferably a hydrogen atom or an alkyl group which may have a substituent, more preferably a hydrogen atom.

[0042] In formula (B3), R 9 ~R 11 each independently represents a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent.

[0043] R 9 ~R 11 Examples of the R 1 ~R 3 Examples of the group include a group represented by the following formula: R 9 is preferably a hydrogen atom or an alkyl group which may have a substituent, more preferably a hydrogen atom. R 10As the alkyl group, a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted amino group is preferred, a hydrogen atom or an optionally substituted amino group is more preferred, and an optionally substituted amino group is even more preferred. R 11 is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably a hydrogen atom.

[0044] In formula (B4), R 12 ~R 14 each independently represents a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent.

[0045] R 12 ~R 14 Examples of the R 1 ~R 3 Examples of the group include a group represented by the following formula: R 12 As the alkyl group, a hydrogen atom or an alkyl group which may have a substituent is preferred, and an alkyl group which may have a substituent is more preferred. R 12 Another preferred embodiment of 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 polyoxyalkylene group-containing group which may have a substituent. R 13 As the alkyl group, a hydrogen atom or an alkyl group which may have a substituent is preferred, and an alkyl group which may have a substituent is more preferred. R 14 is preferably a hydrogen atom or an alkyl group which may have a substituent.

[0046] [ka]

[0047] In formula (B5), R 15 ~R 17 each independently represents a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent.

[0048] R 15 ~R 17 Examples of the R 1 ~R 3 Examples of the group include a group represented by the following formula: R 15 is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably a hydrogen atom. R 16 is preferably a hydrogen atom, an optionally substituted alkyl group or an optionally substituted amino group, more preferably a hydrogen atom or an optionally substituted amino group, and even more preferably a hydrogen atom. R 16 Another preferred embodiment of is a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent. R 17 is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably a hydrogen atom.

[0049] In formula (B6), R 18 ~R 20 each independently represents a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent.

[0050] R 18 ~R 20 Examples of the R 1 ~R 3 Examples of the group include a group represented by the following formula: R18 ~R 20 is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably a hydrogen atom.

[0051] In formula (B7), R 21 ~R 24 each independently represents a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent.

[0052] R 21 ~R 24 For example, R in the above formula (B1) 1 ~R 3 Examples of the group include a group represented by the following formula: R 21 ~R 24 is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably a hydrogen atom.

[0053] Examples of purine compounds include purine, adenine, guanine, hypoxanthine, xanthine, theobromine, caffeine, uric acid, isoguanine, adenosine, enprofylline, theophylline, xanthosine, 7-methylxanthosine, 7-methylxanthine, theophylline, eritadenine, 3-methyladenine, 3-methylxanthine, 1,7-dimethylxanthine, 1-methylxanthine, 1,3-dipropyl-7-methylxanthine, 3,7-dihydro-7-methyl-1H-purine-2,6-dione, and 1,7-dipropyl-3-methyl Xanthine, 1-methyl-3,7-dipropylxanthine, 1,3-dipropyl-7-methyl-8-dicyclopropylmethylxanthine, 1,3-dibutyl-7-(2-oxopropyl)xanthine, 1-butyl-3,7-dimethylxanthine, 3,7-dimethyl-1-propylxanthine, mercaptopurine, 2-aminopurine, 6-aminopurine, 6-benzylaminopurine, nelarabine, vidarabine, 2,6-dichloropurine, acyclovir, N6-benzoyl adenosine, trans-zeatin, 6-benzylaminopurine, Entecavir benzodiazepine, valaciclovir, abacavir, 2'-deoxyguanosine, disodium inosinate, ganciclovir, disodium guanosine 5'-monophosphate, O-cyclohexylmethylguanine, N2-isobutyryl-2'-deoxyguanosine, β-nicotinamide adenine dinucleotide phosphate, 6-chloro-9-(tetrahydropyran-2-yl)purine, clofarabine, kinetin, 7-(2,3-dihydroxypropyl)theophylline, 6-mercaptopurine, proxyphylline, 2,6-diaminopurine, 2',3'-dideoxyinosin Examples of compounds that may be used include 2-chloroadenine, 2-chlorotheophylline-7-acetic acid, 2-chloroadenine, 2-amino-6-chloropurine, 8-bromo-3-methylxanthine, 2-fluoroadenine, penciclovir, 9-(2-hydroxyethyl)adenine, 7-(2-chloroethyl)theophylline, 2-amino-6-iodopurine, 2-thioxanthine, 2-amino-6-methoxypurine, N-acetylguanine, adefovir dipivoxil, 8-chlorotheophylline, 6-methoxypurine, 1-(3-chloropropyl)theobromine, 6-(dimethylamino)purine, and inosine. Among these, the purine compound preferably contains at least one selected from the group consisting of purine, adenine, guanine, hypoxanthine, xanthine, theobromine, caffeine, uric acid, isoguanine, adenosine, enprofylline, xanthosine, 7-methylxanthosine, 7-methylxanthine, theophylline, eritadenine, paraxanthine, 3-methyladenine, 3-methylxanthine, 1,7-dimethylxanthine, and 1-methylxanthine, more preferably contains at least one selected from the group consisting of xanthine, adenine, guanine, hypoxanthine, uric acid, purine, caffeine, isoguanine, theobromine, theophylline, and paraxanthine, even more preferably contains at least one selected from the group consisting of xanthine, hypoxanthine, uric acid, purine, caffeine, and theophylline, and particularly preferably contains at least one selected from the group consisting of xanthine and hypoxanthine.

[0054] The purine compounds may be used singly or in combination of two or more. The content of the purine compound is preferably 0.01 to 5.0% by mass, more preferably 0.03 to 4.0% by mass, and even more preferably 0.05 to 3.0% by mass, relative to the total mass of the cleaning liquid. The content of the purine compound is preferably 0.1 to 50.0 mass %, more preferably 0.3 to 40.0 mass %, and even more preferably 0.5 to 30.0 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0055] The mass ratio of the content of the purine compound to the content of compound A (content of the purine compound / content of compound A) is preferably 0.002 to 30.0, more preferably 0.02 to 20.0, and even more preferably 0.05 to 10.0, in terms of better effects of the present invention.

[0056] [Quaternary ammonium compounds] The cleaning solution may contain a quaternary ammonium compound. The quaternary ammonium compound is a different compound from the compounds described above that may be included in the cleaning solution. The quaternary ammonium compound is preferably a compound having a quaternary ammonium cation in which four hydrocarbon groups (preferably alkyl groups) are substituted on the nitrogen atom. Alternatively, the quaternary ammonium compound may be a compound having a quaternary ammonium cation in which the nitrogen atom on the pyridine ring is bonded to a substituent (a hydrocarbon group such as an alkyl group or an aryl group), such as alkylpyridinium. Examples of quaternary ammonium compounds include quaternary ammonium hydroxides, quaternary ammonium fluorides, quaternary ammonium bromides, quaternary ammonium iodides, quaternary ammonium acetates, and quaternary ammonium carbonates.

[0057] The quaternary ammonium compound is preferably a compound represented by formula (C).

[0058] [ka]

[0059] In formula (C), R c1 ~R c4 each independently represents a hydrocarbon group which may have a substituent, provided that all R c1 ~R c4 Except when X represents the same group. - represents an anion.

[0060] R c1 ~R c4 each independently represents a hydrocarbon group which may have a substituent. The hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms. Examples of the hydrocarbon group include an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, an aryl group which may have a substituent, and a group combining these, and an alkyl group which may have a substituent is preferred. Examples of the substituent on the hydrocarbon group include halogen atoms such as fluorine, chlorine, and bromine atoms; alkoxy groups; hydroxyl groups; alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl groups; acyl groups such as acetyl, propionyl, and benzoyl groups; cyano groups; and nitro groups, with a hydroxyl group being preferred. The number of substituents on the hydrocarbon group is preferably 1 to 3, and more preferably 1.

[0061] The alkyl group, the alkenyl group, and the alkynyl group may be linear, branched, or cyclic. The alkyl group, alkenyl group, and alkynyl group preferably have 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, still more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. Examples of the substituents that the alkyl group, alkenyl group, and alkynyl group have include the substituents that the hydrocarbon group has. The alkyl group is preferably an unsubstituted alkyl group or a hydroxyalkyl group, more preferably a methyl group, an ethyl group, a propyl group, a butyl group or a 2-hydroxyethyl group, and even more preferably a methyl group, an ethyl group or a 2-hydroxyethyl group.

[0062] The aryl group may be either monocyclic or polycyclic. The aryl group preferably has 6 to 20 carbon atoms, more preferably 6 to 10 carbon atoms, and even more preferably 6 to 8 carbon atoms. Examples of the substituent on the aryl group include a halogen atom such as a chlorine atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a nitro group, a thiol group, and a dioxiranyl group. A halogen atom or an alkyl group having 1 to 10 carbon atoms is preferred, an alkyl group having 1 to 10 carbon atoms is more preferred, and an alkyl group having 1 to 3 carbon atoms is even more preferred. The number of substituents on the aryl group is preferably 1 to 5, more preferably 1 to 3, and still more preferably 1. Examples of the aryl group include a benzyl group, a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenabutenyl group, a fluorenyl group, and a pyrenyl group. A benzyl group or a phenyl group is preferred, and a benzyl group is more preferred.

[0063] R c1 ~R c4 It is preferable that two or three of R represent the same group. c1 ~R c4 It is more preferred that three of R represent the same group. c1 ~R c3 represents a 2-hydroxyethyl group, and R c4 Preferably, represents a methyl group.

[0064] However, all R c1 ~R c4 represents the same group. For example, all R c1 ~R c4 is a methyl group. In other words, the compounds represented by formula (C) do not include tetramethylammonium salts.

[0065] X - represents an anion. Examples of the anion include acid anions such as carboxylate ion, phosphate ion, sulfate ion, phosphonate ion, and nitrate ion, hydroxide ion, and halide ions such as chloride ion, fluoride ion, and bromide ion, with hydroxide ion being preferred.

[0066] Examples of quaternary ammonium compounds include tris(2-hydroxyethyl)methylammonium hydroxide (Tris), dimethylbis(2-hydroxyethyl)ammonium hydroxide, tetramethylammonium hydroxide (TMAH), ethyltrimethylammonium hydroxide (ETMAH), trimethylethylammonium hydroxide (TMEAH), dimethyldiethylammonium hydroxide (DMDEAH), methyltriethylammonium hydroxide (MTEAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), 2-hydroxyethyltrimethylammonium hydroxide (choline), bis(2-hydroxyethyl)dimethylammonium hydroxide, tri(2-hydroxyethyl)methylammonium hydroxide, tetra(2-hydroxyethyl)ammonium hydroxide, benzyltrimethylammonium hydroxide (BTMAH), and cetyltrimethylammonium hydroxide, with Tris, choline, or ETMAH being preferred.

[0067] In addition, from the viewpoint of excellent damage resistance, it is also preferable that the quaternary ammonium compound has an asymmetric structure. When the quaternary ammonium compound has an "asymmetric structure," it means that none of the four hydrocarbon groups substituted on the nitrogen atoms are the same. Examples of quaternary ammonium compounds having an asymmetric structure include TMEAH, DEDMAH, TEMAH, choline, and bis(2-hydroxyethyl)dimethylammonium hydroxide.

[0068] The quaternary ammonium compounds may be used alone or in combination of two or more. The content of the quaternary ammonium compound is preferably 0.01 to 20.0 mass %, more preferably 0.05 to 15.0 mass %, and even more preferably 0.1 to 10.0 mass %, relative to the total mass of the cleaning liquid. The content of the quaternary ammonium compound is preferably 0.1 to 95.0 mass %, more preferably 3.0 to 93.0 mass %, and even more preferably 5.0 to 90.0 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0069] [Organic acid] The cleaning solution may contain an organic acid. The organic acid is a compound different from the above-mentioned compounds that may be contained in the cleaning liquid, and is preferably a compound different from the surfactants and / or reducing sulfur compounds described below. Examples of the organic acid include carboxylic acid organic acids and phosphonic acid organic acids, with carboxylic acid organic acids being preferred.

[0070] Examples of the acid group contained in the organic acid include a carboxy group, a phosphonic acid group, a sulfo group, and a phenolic hydroxyl group. The organic acid preferably has at least one selected from the group consisting of a carboxy group and a phosphonic acid group, and more preferably has a carboxy group.

[0071] The organic acid preferably has a low molecular weight. Specifically, the molecular weight of the organic acid is preferably 600 or less, more preferably 450 or less, and even more preferably 300 or less. The lower limit is preferably 50 or more, and more preferably 100 or more. The organic acid preferably has 1 to 15 carbon atoms, more preferably 2 to 15 carbon atoms.

[0072] <Carboxylic acid organic acid> The carboxylic acid organic acid means an organic acid having at least one carboxy group in the molecule. As the carboxylic acid-based organic acid, a compound represented by formula (D) is preferred, and a compound represented by formula (D1) is more preferred.

[0073] [ka]

[0074] In formula (D), L d represents a single bond or a divalent linking group. Examples of the divalent linking group include an ether group, a carbonyl group, an ester group, a thioether group, -SO2-, -NT-, a divalent hydrocarbon group (e.g., an alkylene group, an alkenylene group, an alkynylene group, and an arylene group), and a group formed by combining these. T represents a substituent. The divalent linking group may further have a substituent. Examples of the substituent include an alkyl group, an aryl group, a hydroxyl group, a carboxyl group, an amino group, and a halogen atom, with a hydroxyl group or a carboxyl group being preferred. Among them, L d is preferably a single bond or a divalent hydrocarbon group, more preferably an alkylene group which may have a substituent. The divalent linking group preferably has 1 to 5 substituents, and more preferably 1 to 3 substituents. The divalent linking group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms.

[0075] [ka]

[0076] In formula (D1), R d1 and R d2 each independently represents a hydrogen atom, a hydroxyl group or a carboxyl group, and n represents an integer of 1 to 5.

[0077] R d1 and R d2 The total number of hydroxyl groups contained in is preferably 0 to 4, and more preferably 0 to 2. R d1 and R d2 The total number of carboxy groups contained in is preferably 0 to 4, more preferably 0 to 2, and even more preferably 1. R d1 and R d2 The total number of hydroxyl groups and carboxyl groups contained in the alkyl group is preferably 0 to 8, more preferably 0 to 4, and even more preferably 0 to 2. Multiple Rsd1 Comrades and R d2 The two may be the same or different.

[0078] n represents an integer of 1 to 5. n is preferably 1 to 4, and more preferably 1 to 3.

[0079] Examples of carboxylic acid organic acids include aminopolycarboxylic acid organic acids, amino acid organic acids, and aliphatic carboxylic acid organic acids, with aliphatic carboxylic acid organic acids being preferred.

[0080] Examples of aminopolycarboxylic acid organic acids include 1,4-butanediaminetetraacetic acid (BDTA), diethylenetriaminepentaacetic acid (DTPA), ethylenediaminetetrapropionic acid, triethylenetetraminehexaacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid, 1,3-propanediamine-N,N,N',N'-tetraacetic acid, ethylenediaminetetraacetic acid (EDTA), trans-1,2-diaminocyclohexanetetraacetic acid, and ethylenediaminetetraacetic acid. amine diacetic acid, ethylenediamine dipropionic acid, 1,6-hexamethylene-diamine-N,N,N',N'-tetraacetic acid, N,N-bis(2-hydroxybenzyl)ethylenediamine-N,N-diacetic acid, diaminopropane tetraacetic acid, 1,4,7,10-tetraazacyclododecane-tetraacetic acid, diaminopropanol tetraacetic acid, (hydroxyethyl)ethylenediamine triacetic acid and iminodiacetic acid (IDA), with diethylenetriaminepentaacetic acid (DTPA) being preferred.

[0081] Examples of amino acid organic acids include glycine, serine, α-alanine (2-aminopropionic acid), β-alanine (3-aminopropionic acid), lysine, leucine, isoleucine, cystine, cysteine, ethionine, threonine, tryptophan, tyrosine, valine, histidine, histidine derivatives, asparagine, aspartic acid, glutamine, glutamic acid, arginine, proline, methionine, phenylalanine, the compounds described in paragraphs

[0021] to

[0023] of JP2016-086094A, and salts thereof. Examples of histidine derivatives include compounds described in JP-A-2015-165561 and JP-A-2015-165562, the contents of which are incorporated herein by reference. Examples of salts include alkali metal salts such as sodium salts and potassium salts, ammonium salts, carbonates, and acetates.

[0082] The aliphatic carboxylic acid organic acid may have a hydroxyl group in addition to the carboxylic acid group and the aliphatic group. Examples of the aliphatic carboxylic acid organic acid include tartaric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, maleic acid, malic acid, and citric acid. Among these, the aliphatic carboxylic acid organic acid preferably contains at least one selected from the group consisting of tartaric acid, citric acid, malonic acid and succinic acid, and more preferably contains tartaric acid.

[0083] <Phosphonic organic acids> The phosphonic organic acid is an organic acid having at least one phosphonic acid group in the molecule. When the organic acid has a phosphonic acid group and a carboxy group, it is classified as a carboxylic acid organic acid. Examples of the phosphonic acid-based organic acid include aliphatic phosphonic acid-based organic acids and aminophosphonic acid-based organic acids. The aliphatic phosphonic acid-based organic acid may further have a hydroxyl group in addition to the phosphonic acid group and the aliphatic group. Examples of phosphonic organic acids include ethylidene diphosphonic acid, 1-hydroxyethylidene-1,1'-diphosphonic acid (HEDPO), 1-hydroxypropylidene-1,1'-diphosphonic acid, 1-hydroxybutylidene-1,1'-diphosphonic acid, ethylaminobis(methylenephosphonic acid), dodecylaminobis(methylenephosphonic acid), nitrilotris(methylenephosphonic acid) (NTPO), ethylenediaminebis(methylenephosphonic acid) (EDDPO), 1,3-propylenediaminebis(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid) ) (EDTPO), ethylenediaminetetra(ethylenephosphonic acid), 1,3-propylenediaminetetra(methylenephosphonic acid) (PDTMP), 1,2-diaminopropanetetra(methylenephosphonic acid), 1,6-hexamethylenediaminetetra(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid) (DEPPO), diethylenetriaminepenta(ethylenephosphonic acid), triethylenetetraminehexa(methylenephosphonic acid), and triethylenetetraminehexa(ethylenephosphonic acid), with HEDPO or EDTPO being preferred.

[0084] The number of phosphonic acid groups contained in the phosphonic acid-based organic acid is preferably 2 to 5, more preferably 2 to 4, and even more preferably 2 to 3. The phosphonic acid-based organic acid preferably has 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 8 carbon atoms.

[0085] Examples of phosphonic organic acids include 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, the contents of which are incorporated herein by reference.

[0086] Some commercially available phosphonic acid organic acids contain water such as distilled water, deionized water, and ultrapure water in addition to the phosphonic acid organic acid, and such water-containing phosphonic acid organic acids may also be used.

[0087] When the cleaning solution contains a phosphonic acid-based organic acid, it is also preferable that it further contains another acid (preferably the above-mentioned carboxylic acid-based organic acid). In this case, the mass ratio of the content of the carboxylic acid-based organic acid to the content of the phosphonic acid-based organic acid (content of carboxylic acid-based organic acid / content of phosphonic acid-based organic acid) is preferably 0.1 to 10, more preferably 0.2 to 5, and even more preferably 0.6 to 1.3.

[0088] The organic acid preferably includes at least one selected from the group consisting of aliphatic carboxylic acids and aliphatic phosphonic acids. The organic acid is preferably one or more selected from the group consisting of DTPA, EDTA, trans-1,2-diaminocyclohexanetetraacetic acid, IDA, arginine, glycine, β-alanine, aliphatic carboxylic acid organic acids, HEDPO, NTPO, EDTPO, DEPPO, and gluconic acid, and preferably includes at least one selected from the group consisting of tartaric acid, citric acid, malonic acid, and succinic acid, more preferably includes tartaric acid.

[0089] The organic acids may be used alone or in combination of two or more. The content of the organic acid is preferably 0.01 to 10.0 mass %, more preferably 0.05 to 5.0 mass %, and even more preferably 0.1 to 5.0 mass %, relative to the total mass of the cleaning liquid, in order to achieve well-balanced and excellent performance of the cleaning liquid. The content of the organic acid is preferably 0.01 to 90.0 mass %, more preferably 0.1 to 55.0 mass %, and even more preferably 0.5 to 45.0 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0090] [Amino alcohol] The cleaning solution may contain an amino alcohol. An amino alcohol is a primary amine compound that further has at least one hydroxyl group (preferably a hydroxyl alkyl group) in the molecule. Amino alcohols are compounds different from the compounds described above that may be included in the cleaning solution. The amino alcohol preferably has 1 to 5 hydroxyalkyl groups. The amino alcohol may have secondary and / or tertiary amino groups as long as it is an amino alcohol (primary amino alcohol) having at least one (e.g., 1 to 5) primary amino group in the molecule. The total number of primary to tertiary amino groups in the amino alcohol is preferably 1 to 5. Among these, the amino alcohol is more preferably an amino alcohol having only a primary amino group as the amino group.

[0091] Examples of amino alcohols include monoethanolamine (MEA), 2-amino-2-methyl-1-propanol (AMP), 2-(2-aminoethylamino)ethanol (AAE), 3-amino-1-propanol, 1-amino-2-propanol, 2-[[2-(dimethylamino)ethyl]methylamino]ethanol, N,N'-bis(2-hydroxyethyl)ethylenediamine, 1,1-((3-(dimethylamino)propylimino)-bis-2-propanol, N,N,N'-trimethylaminoethylethanolamine, trishydroxymethylaminomethane, and 2-(aminoethoxy)ethanol (AEE).

[0092] The amino alcohols may be used alone or in combination of two or more. The content of the amino alcohol is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, and even more preferably 0.1 to 4 mass %, relative to the total mass of the cleaning liquid, in order to achieve well-balanced and excellent performance of the cleaning liquid. The content of the amino alcohol is preferably 0.01 to 70 mass %, more preferably 0.1 to 50 mass %, and even more preferably 1.0 to 40 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0093] 〔water〕 The cleaning liquid may contain water as a solvent. The type of water used in the cleaning solution may be distilled water, deionized water, or pure water (ultrapure water), as long as it does not adversely affect the semiconductor substrate. Pure water (ultrapure water) is preferred because it contains almost no impurities and has less of an effect on the semiconductor substrate during the semiconductor substrate manufacturing process. The content of water may be the balance of the components that can be contained in the cleaning liquid. The water content is preferably 1.0% by mass or more, more preferably 30.0% by mass or more, even more preferably 60.0% by mass or more, and particularly preferably 80.0% by mass or more, based on the total mass of the cleaning solution. The upper limit is preferably 99.99% by mass or less, more preferably 99.9% by mass or less, even more preferably 99.0% by mass or less, and particularly preferably 97.0% by mass or less, based on the total mass of the cleaning solution.

[0094] [Surfactant] The cleaning liquid may contain a surfactant. Surfactants are compounds different from the compounds mentioned above that may be included in cleaning solutions. The surfactant is a compound having a hydrophilic group and a hydrophobic group (lipophilic group) in one molecule, and examples thereof include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants, with nonionic surfactants being preferred. It is preferable that the cleaning liquid contains a surfactant, since this provides better corrosion prevention performance for the metal film and better removal of abrasive particles.

[0095] Surfactants often have at least one hydrophobic group selected from the group consisting of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and combinations thereof. When the hydrophobic group contains an aromatic hydrocarbon group, the number of carbon atoms in the hydrophobic group contained in the surfactant is preferably 6 or more, and more preferably 10 or more. When the hydrophobic group does not contain an aromatic hydrocarbon group and is composed only of an aliphatic hydrocarbon group, the number of carbon atoms in the hydrophobic group contained in the surfactant is preferably 9 or more, more preferably 13 or more, and even more preferably 16 or more. The upper limit is preferably 20 or less, and more preferably 18 or less. The surfactant preferably has 16 to 100 carbon atoms in total.

[0096] <Nonionic surfactants> Examples of nonionic surfactants include ester-type nonionic surfactants, ether-type nonionic surfactants, ester-ether-type nonionic surfactants, and alkanolamine-type nonionic surfactants, with ether-type nonionic surfactants being preferred.

[0097] The nonionic surfactant preferably contains a group represented by formula (E1). Equation (E1) *-(LO) n -* In formula (E1), L represents an alkylene group, n represents an integer of 3 to 60, and * represents a bonding position.

[0098] The alkylene group may be either linear or branched. The alkylene group preferably has 1 to 10 carbon atoms, more preferably 2 to 3 carbon atoms, and even more preferably 2 carbon atoms. n is preferably 3 to 30, more preferably 6 to 20, and even more preferably 7 to 15. In other words, examples of the group represented by formula (E1) include polyoxyalkylene groups having a repeating number n (for example, polyoxyethylene groups, polyoxypropylene groups, and polyoxyethylenepolyoxypropylene groups). Of these, as the group represented by formula (E1), a polyoxyethylene group in which n is 3 to 30 is preferred, a polyoxyethylene group in which n is 6 to 20 is more preferred, and a polyoxyethylene group in which n is 7 to 15 is even more preferred.

[0099] The group bonded to the terminal on the O side of the group represented by formula (E1) (i.e., the group bonded to the right side of the group represented by formula (E1)) is preferably other than "*1-LO-*2". L in "*1-LO-*2" is the same as L in formula (E1), *1 is the bonding position to O present at the terminal of the group represented by formula (E1), and *2 is the bonding position on the opposite side to *1. The group bonded to the terminal on the O side of the group represented by formula (E1) (i.e., the group bonded to the left side of the group represented by formula (E1)) is preferably a hydrogen atom, an alkyl group, or an aromatic ring group which may have a substituent, and more preferably a hydrogen atom. The alkyl group may be either linear or branched. The alkyl group preferably has 1 to 30 carbon atoms. The aromatic ring group preferably has 1 to 30 carbon atoms. Examples of the substituent on the aromatic ring group include hydrocarbon groups such as alkyl groups, and hydrocarbon groups having 1 to 30 carbon atoms are preferred.

[0100] The group bonded to the terminal on the L side of the group represented by formula (E1) is preferably other than "*3-OLO-*3." L in "*3-OLO-*3" is the same as L in formula (E1), and *3 is the bonding position. The group bonded to the terminal on the L side of the group represented by formula (E1) is preferably a hydroxyl group, an alkoxy group, or a group represented by an aromatic ring -O- which may have a substituent, more preferably a group represented by an aromatic ring -O- which may have a substituent. The alkoxy group may be either linear or branched. The alkoxy group preferably has 1 to 30 carbon atoms, and more preferably 1 to 20 carbon atoms. The aromatic ring group preferably has 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 3 to 6 carbon atoms. Furthermore, examples of the substituent that the aromatic ring group may have include hydrocarbon groups such as alkyl groups, and hydrocarbon groups having 1 to 30 carbon atoms are preferred.

[0101] The nonionic surfactant more preferably contains a group represented by formula (E2). Formula (E2) -Ph-O-(LO) n - In formula (E2), “(LO) n " has the same meaning as the group represented by formula (E1), and the preferred embodiments are also the same. In formula (E2), Ph represents a phenylene group. The group bonded to the terminal on the Ph side in the group represented by formula (E2) is preferably a hydrogen atom or an alkyl group, more preferably an alkyl group. The alkyl group may be either straight-chain or branched-chain. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and even more preferably 5 to 10 carbon atoms.

[0102] Examples of nonionic surfactants include compounds represented by formula (E). Formula (E) R NA -L NA1 -(LO) n -L NA2 -H In formula (E), "(LO) n " has the same meaning as the group represented by formula (E1), and the preferred embodiments are also the same. In formula (E), R NA represents an alkyl group which may have a substituent, an aryl group which may have a substituent, or a group which is a combination of these (for example, an alkylaryl group (an aryl group substituted with an alkyl group)). Examples of the substituent include a halogen atom such as a fluorine atom and a hydroxyl group. The alkyl group may be either linear or branched. The alkyl group preferably has 1 to 30 carbon atoms, and more preferably has 7 to 15 carbon atoms. The aryl group preferably has a carbon number of 6 to 12. One or more ethylene groups in the alkyl group may be substituted with a vinylene group.

[0103] In formula (E), L NA1 and L NA2 each independently represents a single bond or a divalent linking group. Examples of the divalent linking group include -O-, -CO-, and -NR 11 -, -S-, -SO2-, -PO(OR 12 )-, an alkylene group (preferably having 1 to 6 carbon atoms) which may have a substituent, an arylene group which may have a substituent, or a group combining these groups is preferred. 11represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group. 12 represents an alkyl group, an aryl group, or an aralkyl group. Among them, L NA1 is preferably -O-. NA2 is preferably a single bond.

[0104] Examples of nonionic surfactants include polyoxyalkylene alkyl ethers (e.g., polyoxyethylene stearyl ether, etc.), polyoxyalkylene alkenyl ethers (e.g., polyoxyethylene oleyl ether, etc.), polyoxyethylene alkylphenyl ethers (e.g., polyoxyethylene nonylphenyl ether, etc.), polyoxyalkylene glycols (e.g., polyoxypropylene polyoxyethylene glycol, etc.), polyoxyalkylene monoalkylates (monoalkyl fatty acid ester polyoxyalkylenes) (e.g., polyoxyethylene monostearate and polyoxyethylene monooleate, etc.), and polyoxyalkylene monoacrylates (monoalkyl fatty acid ester polyoxyalkylenes). ethylene monoalkylate), polyoxyalkylene dialkylates (dialkyl fatty acid ester polyoxyalkylene) (for example, polyoxyethylene dialkylates such as polyoxyethylene distearate and polyoxyethylene diolate), bispolyoxyalkylene alkylamides (for example, bispolyoxyethylenestearylamide), sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylamines, glycerin fatty acid esters, oxyethylene oxypropylene block copolymers, acetylene glycol-based surfactants, and acetylene-based polyoxyethylene oxides. Of these, polyoxyethylene alkylphenyl ether is preferred as the nonionic surfactant.

[0105] <Anionic surfactants> Examples of anionic surfactants include phosphate ester surfactants having a phosphate ester group as the hydrophilic group (acid group), phosphonic acid surfactants having a phosphonic acid group, sulfonic acid surfactants having a sulfo group, carboxylic acid surfactants having a carboxy group, and sulfate ester surfactants having a sulfate ester group.

[0106] (phosphate ester surfactant) Examples of the phosphate surfactant include alkyl phosphate esters and polyoxyalkylene alkyl ether phosphate esters, as well as salts thereof. The phosphate ester and polyoxyalkylene alkyl ether phosphate ester generally include both monoesters and diesters, but either the monoester or the diester can be used alone. Examples of salts of phosphate ester surfactants include sodium salts, potassium salts, ammonium salts, and organic amine salts. The monovalent alkyl group contained in the alkyl phosphate ester and polyoxyalkylene alkyl ether phosphate ester is preferably an alkyl group having 2 to 24 carbon atoms, more preferably an alkyl group having 6 to 18 carbon atoms, and even more preferably an alkyl group having 12 to 18 carbon atoms. The divalent alkylene group contained in the polyoxyalkylene alkyl ether phosphate is preferably an alkylene group having 2 to 6 carbon atoms, more preferably an ethylene group or a 1,2-propanediyl group. The number of repeating oxyalkylene groups in the polyoxyalkylene ether phosphate is preferably 1 to 12, more preferably 1 to 6.

[0107] The phosphate ester surfactant is preferably octyl phosphate, lauryl phosphate, tridecyl phosphate, myristyl phosphate, cetyl phosphate, stearyl phosphate, polyoxyethylene octyl ether phosphate, polyoxyethylene lauryl ether phosphate, polyoxyethylene tridecyl ether phosphate, or polyoxyethylene myristyl ether phosphate, more preferably lauryl phosphate, tridecyl phosphate, myristyl phosphate, cetyl phosphate, stearyl phosphate, or polyoxyethylene myristyl ether phosphate, and even more preferably lauryl phosphate, cetyl phosphate, stearyl phosphate, or polyoxyethylene myristyl ether phosphate.

[0108] Examples of the phosphate ester surfactant include the compounds described in paragraphs

[0012] to

[0019] of JP-A-2011-040502, the contents of which are incorporated herein by reference.

[0109] (phosphonic acid surfactants) Examples of phosphonic acid surfactants include alkylphosphonic acid, polyvinylphosphonic acid, and aminomethylphosphonic acid described in JP-A-2012-057108.

[0110] (sulfonic acid surfactants) Examples of sulfonic acid surfactants include alkyl sulfonic acids, alkyl benzene sulfonic acids, alkyl naphthalene sulfonic acids, alkyl diphenyl ether disulfonic acids, alkyl methyl taurines, sulfosuccinic acid diesters, polyoxyalkylene alkyl ether sulfonic acids, and salts thereof.

[0111] The alkyl group contained in the sulfonic acid surfactant is preferably an alkyl group having 2 to 24 carbon atoms, more preferably an alkyl group having 6 to 18 carbon atoms. The alkylene group in the polyoxyalkylene alkyl ether sulfonic acid is preferably an ethylene group or a 1,2-propanediyl group. The number of repeating oxyalkylene groups in the polyoxyalkylene alkyl ether sulfonic acid is preferably 1 to 12, and more preferably 1 to 6.

[0112] Examples of sulfonic acid surfactants include hexanesulfonic acid, octane sulfonic acid, decane sulfonic acid, dodecane sulfonic acid, toluene sulfonic acid, cumene sulfonic acid, octylbenzene sulfonic acid, dodecylbenzene sulfonic acid (DBSA), dinitrobenzene sulfonic acid (DNBSA), and lauryl dodecyl phenyl ether disulfonic acid (LDPEDSA). Dodecane sulfonic acid, DBSA, DNBSA, or LDPEDSA is preferred, and DBSA, DNBSA, or LDPEDSA is more preferred.

[0113] (carboxylic acid surfactants) Examples of carboxylic acid surfactants include alkyl carboxylic acids, alkyl benzene carboxylic acids, polyoxyalkylene alkyl ether carboxylic acids, and salts thereof. The alkyl group contained in the carboxylic acid surfactant is preferably an alkyl group having 7 to 25 carbon atoms, more preferably an alkyl group having 11 to 17 carbon atoms. The alkylene group in the polyoxyalkylene alkyl ether carboxylic acid is preferably an ethylene group or a 1,2-propanediyl group. The number of repeating oxyalkylene groups in the polyoxyalkylene alkyl ether carboxylic acid is preferably 1 to 12, and more preferably 1 to 6.

[0114] Examples of carboxylic acid surfactants include lauric acid, myristic acid, palmitic acid, stearic acid, polyoxyethylene lauryl ether acetic acid, and polyoxyethylene tridecyl ether acetic acid.

[0115] (sulfate ester surfactants) Examples of sulfate surfactants include alkyl sulfates and polyoxyalkylene alkyl ether sulfates, as well as salts thereof. The alkyl group contained in the alkyl sulfate and polyoxyalkylene alkyl ether sulfate is preferably an alkyl group having 2 to 24 carbon atoms, more preferably an alkyl group having 6 to 18 carbon atoms. The alkylene group contained in the polyoxyalkylene alkyl ether sulfate is preferably an ethylene group or a 1,2-propanediyl group. The number of repeating oxyalkylene groups in the polyoxyalkylene alkyl ether sulfate is preferably 1 to 12, and more preferably 1 to 6. Examples of sulfate surfactants include lauryl sulfate, myristyl sulfate, and polyoxyethylene lauryl ether sulfate.

[0116] Examples of surfactants include the compounds described in paragraphs

[0092] to

[0096] of JP 2015-158662 A, paragraphs

[0045] to

[0046] of JP 2012-151273 A, and paragraphs

[0014] to

[0020] of JP 2009-147389 A, the contents of which are incorporated herein by reference.

[0117] The surfactants may be used alone or in combination of two or more. The content of the surfactant is preferably 0.001 to 8.0 mass %, more preferably 0.005 to 5.0 mass %, and even more preferably 0.01 to 3.0 mass %, relative to the total mass of the cleaning liquid, in order to achieve well-balanced and excellent performance of the cleaning liquid. The content of the surfactant is preferably 0.01 to 50.0 mass%, more preferably 0.1 to 45.0 mass%, even more preferably 0.7 to 40.0 mass%, and particularly preferably 0.7 to 10.0 mass%, relative to the total mass of the components in the cleaning liquid excluding the solvent, in order to achieve well-balanced and excellent performance of the cleaning liquid.

[0118] [Azole compounds] The cleaning solution may contain an azole compound. The azole compound is a compound different from the compounds described above that may be contained in the cleaning solution. An azole compound is a compound having at least one nitrogen atom and a five-membered heterocyclic ring having aromaticity. The azole compounds may improve the corrosion inhibition of the cleaning solution, i.e., they may act as corrosion inhibitors. The number of nitrogen atoms contained in the five-membered hetero ring of the azole compound is preferably 1 to 4, and more preferably 1 to 3. The azole compound may have a substituent on the five-membered hetero ring. Examples of the substituent include a hydroxyl group, a carboxy group, a mercapto group, an amino group, an alkyl group having 1 to 4 carbon atoms which may have an amino group, and a 2-imidazolyl group.

[0119] Examples of azole compounds include imidazole compounds in which one of the atoms constituting the azole ring is a nitrogen atom, pyrazole compounds in which two of the atoms constituting the azole ring are nitrogen atoms, thiazole compounds in which one of the atoms constituting the azole ring is a nitrogen atom and the other is a sulfur atom, triazole compounds in which three of the atoms constituting the azole ring are nitrogen atoms, and tetrazole compounds in which four of the atoms constituting the azole ring are nitrogen atoms.

[0120] Examples of imidazole compounds include imidazole, 1-methylimidazole, 2-methylimidazole, 5-methylimidazole, 1,2-dimethylimidazole, 2-mercaptoimidazole, 4,5-dimethyl-2-mercaptoimidazole, 4-hydroxyimidazole, 2,2'-biimidazole, 4-imidazolecarboxylic acid, histamine, and benzimidazole.

[0121] Examples of pyrazole compounds include pyrazole, 4-pyrazolecarboxylic acid, 1-methylpyrazole, 3-methylpyrazole, 3-amino-5-methylpyrazole, 3-amino-5-hydroxypyrazole, 3-aminopyrazole, and 4-aminopyrazole.

[0122] Examples of thiazole compounds include 2,4-dimethylthiazole, benzothiazole, and 2-mercaptobenzothiazole.

[0123] Examples of triazole compounds include 1,2,4-triazole, 3-methyl-1,2,4-triazole, 3-amino-1,2,4-triazole, 1,2,3-triazole, 1-methyl-1,2,3-triazole, benzotriazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole, 4-carboxybenzotriazole, 5-methylbenzotriazole, and 2,2'-{[(5-methyl-1H-benzotriazol-1-yl)methyl]imino}diethanol.

[0124] Examples of tetrazole compounds include 1H-tetrazole (1,2,3,4-tetrazole), 5-methyl-1,2,3,4-tetrazole, 5-amino-1,2,3,4-tetrazole, 1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole, and 1-(2-dimethylaminoethyl)-5-mercaptotetrazole.

[0125] The azole compound is preferably a triazole compound, an imidazole compound, or a pyrazole compound, and more preferably a triazole compound, a pyrazole, or 3-amino-5-methylpyrazole.

[0126] The azole compounds may be used alone or in combination of two or more. The content of the azole compound is preferably from 0.01 to 10% by mass, more preferably from 0.05 to 5% by mass, and even more preferably from 0.1 to 4% by mass, based on the total mass of the cleaning liquid. The content of the azole compound is preferably 0.01 to 95 mass %, more preferably 0.1 to 85 mass %, and even more preferably 1.0 to 80 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0127] [Polyhydroxy compounds with a molecular weight of 500 or more] The cleaning solution may contain a polyhydroxy compound having a molecular weight of 500 or more. The polyhydroxy compound is a compound different from the compounds that may be contained in the cleaning solution. The polyhydroxy compound is an organic compound having two or more (for example, 2 to 200) alcoholic hydroxyl groups in one molecule. The molecular weight of the polyhydroxy compound (weight average molecular weight when it has a molecular weight distribution) is 500 or more, preferably 500 to 100,000, and more preferably 500 to 3,000.

[0128] Examples of the polyhydroxy compound include polyoxyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene glycol; oligosaccharides such as mannitol, cellotriose, gentianose, raffinose, melezitose, cerotetrose, and stachyose; and polysaccharides such as starch, glycogen, cellulose, chitin, and chitosan, and hydrolysates thereof.

[0129] Cyclodextrin is also a preferred example of the polyhydroxy compound. Cyclodextrin refers to a type of cyclic oligosaccharide in which multiple D-glucose units are linked by glucoside bonds to form a ring structure. Compounds in which five or more (e.g., six to eight) glucose units are linked are known. Examples of cyclodextrin include α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, with γ-cyclodextrin being preferred.

[0130] The polyhydroxy compounds may be used alone or in combination of two or more. The content of the polyhydroxy compound is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and even more preferably 0.1 to 3% by mass, based on the total mass of the cleaning liquid. The content of the polyhydroxy compound is preferably 0.01 to 30 mass %, more preferably 0.05 to 25 mass %, and even more preferably 0.5 to 20 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0131] [Reduced sulfur compounds] The cleaning solution may contain reducing sulfur compounds. The reducing sulfur compounds are compounds different from the compounds described above that may be contained in the cleaning solution. The reducing sulfur compound is a compound that has reducing properties and contains a sulfur atom. The reducing sulfur compounds may improve the corrosion protection of the cleaning solution, i.e., they may act as corrosion inhibitors.

[0132] Examples of reducing sulfur compounds include 3-mercapto-1,2,4-triazole, mercaptosuccinic acid, dithiodiglycerol, bis(2,3-dihydroxypropylthio)ethylene, sodium 3-(2,3-dihydroxypropylthio)-2-methyl-propylsulfonate, 1-thioglycerol, sodium 3-mercapto-1-propanesulfonate, 2-mercaptoethanol, thioglycolic acid, and 3-mercapto-1-propanol. Among these, compounds having an SH group (mercapto compounds) are preferred, and 1-thioglycerol, sodium 3-mercapto-1-propanesulfonate, 2-mercaptoethanol, 3-mercapto-1-propanol, or thioglycolic acid are more preferred.

[0133] The above reducing sulfur compounds may be used alone or in combination of two or more. The content of the reducing sulfur compound is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, and even more preferably 0.1 to 3 mass %, based on the total mass of the cleaning liquid. The content of the reducing sulfur compound is preferably 0.01 to 30.0 mass %, more preferably 0.05 to 25.0 mass %, and even more preferably 0.5 to 20.0 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0134] [Polymer] The cleaning solution may include a polymer. The polymer is a compound different from the compounds that may be contained in the cleaning solution.

[0135] It is also preferred that the polymer is a water-soluble polymer. The term "water-soluble polymer" refers to a compound in which two or more structural units are linked together in a linear or network pattern via covalent bonds, and which dissolves in 100 g of water at 20°C in a mass of 0.1 g or more.

[0136] Examples of water-soluble polymers include polyacrylic acid, polymethacrylic acid, polymaleic acid, polyvinyl sulfonic acid, polyallylsulfonic acid, polystyrene sulfonic acid, and salts thereof; copolymers of monomers such as styrene, α-methylstyrene, and / or 4-methylstyrene with acid monomers such as (meth)acrylic acid and / or maleic acid, and salts thereof; polymers having structural units with aromatic hydrocarbon groups, obtained by condensing benzenesulfonic acid and / or naphthalenesulfonic acid with formalin, and salts thereof; polyglycerin; vinyl-based synthetic polymers such as polyvinyl alcohol, polyoxyethylene, polyvinylpyrrolidone, polyvinylpyridine, polyacrylamide, polyvinylformamide, polyethyleneimine, polyvinyloxazoline, polyvinylimidazole, and polyallylamine; and modified natural polysaccharides such as hydroxyethyl cellulose, carboxymethyl cellulose, and processed starch.

[0137] The water-soluble polymer may be a homopolymer or a copolymer obtained by copolymerizing two or more types of monomers. Examples of such a monomer include a monomer selected from the group consisting of a monomer having a carboxylic acid group, a monomer having a sulfonic acid group, a monomer having a hydroxyl group, a monomer having a polyethylene oxide chain, a monomer having an amino group, and a monomer having a heterocycle. The water-soluble polymer is also preferably a polymer consisting essentially of structural units derived from monomers selected from the above group. For example, the content of structural units derived from monomers selected from the above group, relative to the total mass of the polymer, is preferably 95 to 100 mass%, more preferably 99 to 100 mass%.

[0138] Examples of the polymer include the water-soluble polymers described in paragraphs

[0043] to

[0047] of JP 2016-171294 A, the contents of which are incorporated herein by reference.

[0139] The molecular weight of the polymer (weight average molecular weight when the polymer has a molecular weight distribution) is preferably 300 or more, more preferably more than 600, further preferably 1000 or more, particularly preferably more than 1000, and most preferably 2000 or more. The upper limit is preferably 1,500,000 or less, more preferably 1,000,000 or less. In particular, when the polymer is a water-soluble polymer described below, the weight-average molecular weight of the water-soluble polymer is preferably 300 or more, more preferably 1000 or more, even more preferably 1500 or more, and particularly preferably 2000 or more. The upper limit is preferably 1,500,000 or less, more preferably 1,200,000 or less, and even more preferably 1,000,000 or less. The polymer preferably has a structural unit having a carboxy group (such as a structural unit derived from (meth)acrylic acid). The content of the structural unit having a carboxy group is preferably 30 to 100% by mass, more preferably 70 to 100% by mass, and even more preferably 85 to 100% by mass, based on the total mass of the polymer.

[0140] The polymers may be used alone or in combination of two or more. The content of the polymer is preferably from 0.01 to 10% by mass, more preferably from 0.05 to 5% by mass, and even more preferably from 0.1 to 3% by mass, based on the total mass of the cleaning liquid. The content of the polymer is preferably 1 to 50 mass %, more preferably 2 to 35 mass %, and even more preferably 5 to 25 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent. When the polymer content is within the above range, the polymer is appropriately adsorbed onto the surface of the substrate, which contributes to improving the corrosion prevention performance of the cleaning liquid, and the viscosity and / or cleaning performance of the cleaning liquid are well balanced.

[0141] [Oxidizing Agent] The cleaning solution may contain an oxidizing agent. The oxidizing agent is a compound different from the compounds described above that may be included in the cleaning solution. Oxidizing agents include, for example, peroxides, persulfides (eg, monopersulfides and dipersulfides), and percarbonates, acids thereof, and salts thereof. Examples of oxidizing agents 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.). The content of the oxidizing agent is preferably 0.01 to 10.0 mass %, more preferably 0.05 to 5.0 mass %, and even more preferably 0.1 to 3.0 mass %, relative to the total mass of the cleaning liquid. The content of the oxidizing agent is preferably 5.0 to 60.0 mass %, more preferably 10.0 to 50.0 mass %, and even more preferably 10.0 to 40.0 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0142] [Other amine compounds] The cleaning liquid may also contain other amine compounds. The other amine compound is a compound different from the above-mentioned compounds that may be contained in the cleaning liquid. Specifically, as an example, an aliphatic tertiary amine compound is a compound different from compound A. The other amine compounds are preferably alicyclic amine compounds, aliphatic amine compounds, or hydrazine compounds, more preferably aliphatic tertiary amine compounds, and also include, for example, hydrazide compounds.

[0143] The alicyclic amine compound is not particularly limited as long as it is a compound having a non-aromatic heterocycle in which at least one atom constituting the ring is a nitrogen atom. Examples of the alicyclic amine compound include piperazine compounds and cyclic amidine compounds.

[0144] Piperazine compounds are compounds having a six-membered heterocyclic ring (piperazine ring) in which opposing —CH— groups of a cyclohexane ring are replaced with nitrogen atoms. The piperazine compound may have a substituent on the piperazine ring. Examples of the substituent include a hydroxyl group, an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group, and an aryl group having 6 to 10 carbon atoms. The substituents may be bonded to each other.

[0145] Examples of the piperazine compound include piperazine, 1-methylpiperazine, 1-ethylpiperazine, 1-propylpiperazine, 1-butylpiperazine, 2-methylpiperazine, 1,4-dimethylpiperazine, 2,5-dimethylpiperazine, 2,6-dimethylpiperazine, 1-phenylpiperazine, 2-hydroxypiperazine, 2-hydroxymethylpiperazine, 1-(2-hydroxyethyl)piperazine (HEP), N-(2-aminoethyl)piperazine, and the like. Examples of suitable bis(2-hydroxyethyl)piperazines include N-methyl-N'-(2-dimethylaminoethyl)piperazine (AEP), 1,4-bis(2-hydroxyethyl)piperazine (BHEP), 1,4-bis(2-aminoethyl)piperazine (BAEP), 1,4-bis(3-aminopropyl)piperazine (BAPP), N-methyl-N'-(2-dimethylaminoethyl)piperazine, N,N',N''-tris(3-dimethylaminopropyl)-hexahydro-s-triazine, and 1,4-diazabicyclo[2.2.2]octane (DABCO).

[0146] Cyclic amidine compounds are compounds that have a heterocycle containing an amidine structure (>NC=N-) within the ring. The number of ring members in the heterocycle of the cyclic amidine compound is preferably 5 or 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.

[0147] In addition to the above, examples of the alicyclic amine compounds include compounds having a non-aromatic 5-membered hetero ring, such as 1,3-dimethyl-2-imidazolidinone and imidazolidinethione, compounds having a 6-membered ring containing an oxygen atom, such as morpholine (for example, N-(2-hydroxyethylmorpholine and 4-(2-cyanoethyl)morpholine), and compounds having a 7-membered ring containing a nitrogen atom.

[0148] Examples of the aliphatic amine compound include aliphatic primary amine compounds (aliphatic amine compounds having a primary amino group), aliphatic secondary amine compounds (aliphatic amine compounds having a secondary amino group), and aliphatic tertiary amine compounds (aliphatic amine compounds having a tertiary amino group), and from the viewpoint of achieving better effects of the present invention, aliphatic tertiary amine compounds are preferred. The aliphatic amine compound may have amino groups of different series. In this specification, when an aliphatic amine compound has multiple amino groups, it is classified into aliphatic primary to tertiary amine compounds based on the highest amino group it has. Specifically, diethylenetriamine is a compound having a primary amino group and a secondary amino group, and since the highest amino group is a secondary amino group, it is classified as an aliphatic secondary amine compound.

[0149] Examples of the aliphatic primary amine compound include methylamine, ethylamine, propylamine, dimethylamine, diethylamine, n-butylamine, 3-methoxypropylamine, tert-butylamine, n-hexylamine, n-octylamine, and 2-ethylhexylamine.

[0150] Examples of the aliphatic secondary amine compound 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.

[0151] Examples of the aliphatic tertiary amine compound include aliphatic tertiary amine compounds having a tertiary amino group in the molecule but not having an aromatic ring group. In addition, some of the methylene groups (-CH2-) in the aliphatic tertiary amine compound may be replaced with heteroatoms (for example, oxygen atoms, sulfur atoms, etc.). The aliphatic tertiary amine compound preferably has two or more nitrogen atoms, and more preferably has two or more tertiary amino groups. Examples of aliphatic tertiary amine compounds include tertiary alkylamine compounds such as trimethylamine and triethylamine; alkylenediamine compounds such as 3-(dimethylamino)propylamine and 1,3-bis(dimethylamino)butane; and polyalkylpolyamine compounds such as bis(2-dimethylaminoethyl)ether, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylhexamethylenediamine, N,N,N',N'',N''',N'''-hexamethyltriethylenetetramine, and N,N,N',N'',N''-pentamethyldiethylenetriamine, with N,N,N',N'',N''-pentamethyldiethylenetriamine being preferred.

[0152] The hydrazine compound includes hydrazine and its salts, with hydrazine being preferred. Salts of hydrazine include, for example, hydrochloride, hydrobromide, and carbonate. Examples of the hydrazide compounds and salts thereof include adipic acid dihydrazide, sebacic acid dihydrazide, dodecanediohydrazide, isophthalic acid dihydrazide, salicylic acid hydrazide, and salts thereof.

[0153] As other amine compounds, amine compounds having a pKa of 8 or more are also preferred. The pKa is preferably 8.5 or higher, more preferably 10 or higher, and even more preferably 11 or higher. The upper limit is preferably 20 or lower, and more preferably 15 or lower. Examples of the amine compounds having a pKa of 8 or more include compounds having an imino group (>C=NR and -C-NH-, where R represents a hydrogen atom or a substituent), and specific examples include guanidine and guanidine derivatives (e.g., 1,1,3,3-tetramethylguanidine, etc.); cyclic amidine compounds such as 1,4-diazabicyclo[2.2.2]octane, diazabicycloundecene, and diazabicyclononene; and compounds having a 6-membered ring containing an oxygen atom, such as morpholine. The amine compound having a pKa of 8 or more preferably contains at least one compound selected from the group consisting of guanidine, guanidine derivatives, and cyclic amidine compounds, and more preferably contains at least one compound selected from the group consisting of 1,1,3,3-tetramethylguanidine and diazabicycloundecene. The pKa can be measured by known methods such as neutralization titration, absorptiometry, and capillary electrophoresis.

[0154] When the cleaning solution contains the amine compound having a pKa of 8 or more, it may further contain a quaternary ammonium compound, or it may not contain a quaternary ammonium compound. In other words, the amine compound having a pKa of 8 or more can be used as a substitute for a quaternary ammonium compound.

[0155] Other amine compounds include, for example, organic amine compounds described in paragraphs

[0019] to

[0027] of JP2014-037585A, which are different from the above-mentioned components, the contents of which are incorporated herein by reference.

[0156] The other amine compounds may be used alone or in combination of two or more. The content of the other amine compounds is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and even more preferably 0.1 to 4% by mass, based on the total mass of the cleaning liquid. The content of the other amine compounds is preferably 0.01 to 70 mass %, more preferably 0.1 to 50 mass %, and even more preferably 1.0 to 40 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0157] [pH adjuster] The cleaning solution may contain a pH adjuster to adjust and maintain the pH of the cleaning solution. The pH adjuster is a basic compound or an acidic compound that is different from the compounds that may be contained in the cleaning solution, although it is permissible to adjust the pH of the cleaning solution by adjusting the amount of each of the above components added.

[0158] The basic compound includes a basic organic compound and a basic inorganic compound. Examples of basic organic compounds include amine oxides, nitro, nitroso, oximes, ketoximes, aldoximes, lactams, isocyanides, and ureas. Examples of basic inorganic compounds include alkali metal hydroxides, alkaline earth metal hydroxides, and ammonia. Examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, potassium hydroxide, and cesium hydroxide. Examples of alkaline earth metal hydroxides include calcium hydroxide, strontium hydroxide, and barium hydroxide.

[0159] Examples of acidic compounds include inorganic acids. Examples of inorganic acids include hydrochloric acid, sulfuric acid, sulfurous acid, nitric acid, nitrous acid, phosphoric acid, boric acid, and hexafluorophosphate. In addition, salts of inorganic acids may be used, such as ammonium salts of inorganic acids, more specifically ammonium chloride, ammonium sulfate, ammonium sulfite, ammonium nitrate, ammonium nitrite, ammonium phosphate, ammonium borate, and ammonium hexafluorophosphate.

[0160] As the acidic compound, a salt of an acidic compound may be used as long as it becomes an acid or an acid ion (anion) in an aqueous solution.

[0161] The pH adjusters may be used alone or in combination of two or more. The content of the pH adjuster can be selected depending on the types and amounts of other components and the desired pH of the cleaning solution. For example, the content of the pH adjuster is preferably 0.01 to 10% by mass, more preferably 0.1 to 8% by mass, based on the total mass of the cleaning solution. The content of the pH adjuster is preferably 0.01 to 80 mass %, more preferably 0.1 to 60 mass %, based on the total mass of the components in the cleaning liquid excluding the solvent.

[0162] The cleaning liquid may contain a fluorine compound and / or an organic solvent in addition to the above compounds. Examples of fluorine compounds include compounds described in paragraphs

[0013] to

[0015] of JP-A No. 2005-150236, the contents of which are incorporated herein by reference. As the organic solvent, any known organic solvent can be used, and hydrophilic organic solvents such as alcohols and ketones are preferred. The organic solvents may be used alone or in combination of two or more kinds. The amounts of the fluorine compound and the organic solvent used may be appropriately determined within a range that does not impair the effects of the present invention.

[0163] The content of each of the above components in the cleaning solution can be measured by known methods such as gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), and ion-exchange chromatography (IC).

[0164] [Physical properties of cleaning solution] <ph> The cleaning solution may be either alkaline or acidic. In order to ensure well-balanced performance of the cleaning solution, the pH of the cleaning solution is preferably 8.0 to 14.0, more preferably 9.0 to 13.5, even more preferably 9.5 to 13.0, and particularly preferably 10.0 to 13.0. The pH of the cleaning solution refers to the pH of the undiluted cleaning solution. When the cleaning liquid is diluted before use, the pH of the diluted cleaning liquid is preferably 7.5 to 14.0, more preferably 8.0 to 13.5, even more preferably 9.0 to 13.0, and particularly preferably 9.5 to 13.0. The pH of the cleaning solution can be measured using a known pH meter according to the method in accordance with JIS Z8802-1984. The pH measurement temperature is 25°C.

[0165] <Metal content> The cleaning solution preferably contains 5 mass ppm or less (measured as an ion concentration) of metal impurities (metal elements Fe, Co, Na, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, Sn, and Ag), and more preferably 1 mass ppm or less. Since it is expected that even higher purity cleaning solutions will be required in the manufacture of cutting-edge semiconductor devices, the metal content is more preferably lower than 1 mass ppm, i.e., on the order of ppb or less, particularly preferably 100 mass ppb or less, and most preferably less than 10 mass ppb. The lower limit is preferably 0.

[0166] Methods for reducing the metal content include, for example, performing purification treatments such as distillation and filtration using an ion exchange resin or a filter at the stage of raw materials used in producing the cleaning liquid or at the stage after the cleaning liquid is produced. Other methods for reducing the metal content include using a container that allows less elution of impurities, as described below, as a container for storing raw materials or the produced cleaning solution, and applying a fluororesin lining to the inner wall of a pipe or the like during production of the cleaning solution to prevent elution of metal components from the pipe.

[0167] <Coarse particles> The cleaning liquid may contain coarse particles, but it is preferable that the content of coarse particles is low. Coarse particles refer to particles whose diameter (particle size) is 0.03 μm or more when the particle shape is considered to be a sphere. The content of coarse particles in the cleaning solution 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 cleaning solution. The lower limit is preferably 0 or more, more preferably 0.01 or more, per mL of cleaning solution. The coarse particles contained in the cleaning solution 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 during the preparation of the cleaning solution, which ultimately remain as particles without dissolving in the cleaning solution. The content of coarse particles present in the cleaning liquid can be measured in the liquid phase using a commercially available measuring device that uses a laser as a light source and is a liquid-borne particle measuring method based on light scattering. Examples of methods for removing coarse particles include purification treatments such as filtering, which will be described later.

[0168] <Electrical conductivity> The electrical conductivity of the cleaning liquid is preferably from 0.06 to 500 mS / cm, more preferably from 0.07 to 300 mS / cm, and even more preferably from 0.08 to 100 mS / cm. The electrical conductivity is the electrical conductivity (mS / cm) measured using an electrical conductivity meter (electrical conductivity meter: portable type D-70 / ES-70 series, manufactured by Horiba, Ltd.). The electrical conductivity can be adjusted, for example, by adjusting the type and content of the compounds that can be contained in the cleaning solution.

[0169] [Production of cleaning solution] The cleaning solution can be produced by a known method, which will be described in detail below.

[0170] <Liquid preparation process> The cleaning solution can be prepared, for example, by mixing the above components. The order and / or timing of mixing the above-mentioned components can be, for example, a method in which a purine compound, compound A, a quaternary ammonium compound, and / or an organic acid are sequentially added to a container containing purified water, followed by stirring to mix and adding a pH adjuster to adjust the pH of the mixture. When water and the components are added to a container, they may be added all at once or in multiple divided portions.

[0171] The stirring device and stirring method used to prepare the cleaning solution may be a known device such as a stirrer or disperser. Examples of the stirrer include an industrial mixer, a portable stirrer, a mechanical stirrer, and a magnetic stirrer. Examples of the disperser include an industrial disperser, a homogenizer, an ultrasonic disperser, and a bead mill.

[0172] The mixing of the components in the cleaning solution preparation step, the purification treatment described below, and the storage of the produced cleaning solution 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 cleaning solution within the above temperature range, the performance can be maintained stably for a long period of time.

[0173] (Refining process) It is preferable to perform a purification treatment in advance on one or more of the raw materials for preparing the cleaning liquid, for example, by known methods such as distillation, ion exchange, and filtration. The degree of purification is preferably such that the purity of the raw material is 99% by mass or more, and more preferably such that the purity of the undiluted solution is 99.9% by mass or more.

[0174] Examples of purification methods include passing the raw material through an ion exchange resin or a reverse osmosis membrane (RO membrane), distilling the raw material, and filtering, which will be described later. The purification process may be a combination of the above purification methods. For example, the raw material may be subjected to a primary purification step in which it is passed through an RO membrane, followed by a secondary purification step in which it is passed through a purification device made of a cation exchange resin, an anion exchange resin, or a mixed-bed ion exchange resin. The purification process may be carried out multiple times.

[0175] (filtering) 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-based resins such as nylon, 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-based resins (including nylon) are preferred, with fluororesin filters being more preferred. Filtering raw materials using filters made of these materials can effectively remove highly polar foreign matter that is likely to cause defects.

[0176] The critical surface tension of the filter is preferably 70 to 95 mN / m, and more preferably 75 to 85 mN / m. The critical surface tension value of the filter is the nominal value provided by the manufacturer. By using a filter with a critical surface tension within the above range, highly polar foreign matter that is likely to cause defects can be effectively removed.

[0177] The pore size of the filter is preferably 2 to 20 nm, more preferably 2 to 15 nm. By setting the pore size within this range, it is possible to reliably remove impurities and fine foreign matter such as aggregates contained in the raw material while suppressing filtration clogging. The nominal value of the filter manufacturer can be used as the pore size here.

[0178] Filtering may be performed only once, or may be performed two or more times. When filtering is performed two or more times, the filters used may be the same or different.

[0179] Filtering is preferably carried out at room temperature (25° C.) or below, more preferably 23° C. or below, and even more preferably 20° C. or below. Filtering is preferably carried out at a temperature above 0° C., more preferably above 5° C., and even more preferably above 10° C. By filtering within the above temperature range, the amount of particulate foreign matter and impurities dissolved in the raw material can be reduced, and foreign matter and impurities can be efficiently removed.

[0180] (container) The cleaning solution (including the kit or the diluted cleaning solution described below) can be filled into any container for storage, transport, and use, as long as corrosiveness and other factors do not pose a problem.

[0181] The container is preferably one for semiconductor applications that has a high degree of cleanliness within the container and that inhibits the elution of impurities from the inner wall of the container's storage section into each liquid. Examples of such containers include various containers commercially available as containers for semiconductor cleaning liquids, 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. Furthermore, as a container for storing cleaning liquids, it is preferable that the parts that come into contact with each liquid, such as the inner walls of the storage section, are made of fluororesin (perfluororesin) or metal that has been treated to prevent rust and metal elution. The inner wall of the container is preferably formed from one or more resins selected from the group consisting of polyethylene resin, polypropylene resin, and polyethylene-polypropylene resin, or a different resin, or a metal that has been treated to prevent rust and metal elution, such as stainless steel, Hastelloy, Inconel, or Monel.

[0182] The different resin is preferably a fluororesin (perfluororesin). By using a container whose inner wall is made of a fluororesin, the occurrence of the problem of elution of ethylene or propylene oligomers can be suppressed compared to a container whose inner wall is made of a polyethylene resin, a polypropylene resin, or a polyethylene-polypropylene resin. An example of such a container whose inner wall is a fluororesin is the FluoroPure PFA composite drum manufactured by Entegris, Inc. In addition, containers described on page 4 of JP-A-3-502677, page 3 of WO 2004 / 016526, and pages 9 and 16 of WO 99 / 46309 can also be used.

[0183] In addition to the above-mentioned fluororesin, quartz and electrolytically polished metal materials (that is, metal materials that have been electrolytically polished) are also preferably used for the inner wall of the container. The metal material used to produce the electropolished metal material preferably contains at least one element selected from the group consisting of chromium and nickel, and the total content of chromium and nickel is more than 25 mass% relative to the total mass of the metal material, and examples thereof include stainless steel and nickel-chromium alloys. The total content of chromium and nickel in the metal material is more preferably 30 mass % or more based on the total mass of the metal material. In general, the upper limit of the total content of chromium and nickel in the metal material is preferably 90 mass % or less.

[0184] Known methods can be used to electropolish metal materials, such as those described in paragraphs

[0011] to

[0014] of JP 2015-227501 A and paragraphs

[0036] to

[0042] of JP 2008-264929 A.

[0185] The interior of these containers is preferably cleaned before filling with the cleaning liquid. The liquid used for cleaning is preferably one that has a reduced amount of metal impurities. After production, the cleaning liquid may be bottled in a container such as a gallon bottle or a coated bottle, and then transported and stored.

[0186] To prevent changes in the components of the cleaning solution 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. The solution may be stored at room temperature during transportation and storage, or the temperature may be controlled to a range of -20°C to 20°C to prevent deterioration.

[0187] (clean room) It is preferable that all of the processes, including manufacturing the cleaning solution, opening and cleaning the container, filling the cleaning solution, handling, processing, analysis, and measurement, be 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.

[0188] <Dilution process> The cleaning liquid may be subjected to a dilution step in which it is diluted with a diluent such as water, and then used as a diluted cleaning liquid (diluted cleaning liquid) for cleaning semiconductor substrates. In addition, a diluted cleaning solution is also one form of the cleaning solution of the present invention as long as it satisfies the requirements of the present invention.

[0189] The dilution rate of the cleaning solution in the dilution step may be adjusted as appropriate depending on the type and content of each component and the semiconductor substrate to be cleaned, etc., but the ratio of the diluted cleaning solution to the cleaning solution before dilution (dilution factor) is preferably 10 to 10,000 times, more preferably 20 to 3,000 times, and even more preferably 50 to 1,000 times in mass ratio or volume ratio (volume ratio at 23°C). In addition, the cleaning liquid is preferably diluted with water in order to obtain better defect suppression performance. In other words, a cleaning solution (diluted cleaning solution) containing each component in an amount obtained by dividing the preferred content of each component (excluding water) that can be contained in the above cleaning solution by a dilution ratio within the above range (for example, 100) can also be suitably used. In other words, the preferred content of each component (excluding water) relative to the total mass of the diluted cleaning solution is, for example, the amount described as the preferred content of each component relative to the total mass of the cleaning solution (cleaning solution before dilution) divided by the dilution ratio (e.g., 100) in the above range.

[0190] The change in pH before and after dilution (the difference between the pH of the cleaning solution before dilution and the pH of the diluted cleaning solution) is preferably 2.0 or less, more preferably 1.8 or less, and even more preferably 1.5 or less. The pH of the cleaning solution before dilution and the pH of the diluted cleaning solution are preferably in the above-mentioned preferred embodiments.

[0191] The specific method of the dilution step of diluting the cleaning liquid may be performed in accordance with the above-mentioned cleaning liquid preparation step. The stirring device and stirring method used in the dilution step may also be the same as those used in the above-mentioned cleaning liquid preparation step.

[0192] It is preferable to subject the water used in the dilution step to a purification treatment in advance, and it is also preferable to subject the diluted cleaning liquid obtained in the dilution step to a purification treatment. Examples of the purification treatment include the ion component reduction treatment using an ion exchange resin or an RO membrane, etc., and the removal of foreign matter using filtering, which are described above as purification treatments for the cleaning liquid, and it is preferable to perform either of these treatments.

[0193] [Uses of cleaning solution] The cleaning liquid is preferably used in a cleaning step for cleaning semiconductor substrates that have been subjected to chemical mechanical polishing (CMP) processing. The cleaning liquid can also be used for cleaning semiconductor substrates in the manufacturing process of semiconductor substrates. As described above, a diluted cleaning solution obtained by diluting the cleaning solution may be used to clean the semiconductor substrate.

[0194] [Item to be cleaned] An example of an object to be cleaned with the cleaning liquid is a semiconductor substrate containing metal. Note that "on a semiconductor substrate" includes, for example, the front and back surfaces, side surfaces, and inside grooves of the semiconductor substrate. Furthermore, metal inclusions on a semiconductor substrate include not only cases where metal inclusions are present directly on the surface of the semiconductor substrate, but also cases where metal inclusions are present on the semiconductor substrate via another layer. The object to be cleaned is preferably a semiconductor substrate containing at least one selected from the group consisting of a Ru-containing material and a RuO2-containing material. Examples of the semiconductor substrate include a semiconductor substrate having a Ru-containing material, a semiconductor substrate having a RuO2-containing material, and a laminate of a Ru-containing material and a RuO2-containing layer formed on the surface of the Ru-containing material.

[0195] Examples of the metal contained in the metal inclusion include at least one metal M selected from the group consisting of Ru (ruthenium), Cu (copper), Co (cobalt), W (tungsten), Ti (titanium), Ta (tantalum), Cr (chromium), Hf (hafnium), Os (osmium), Pt (platinum), Ni (nickel), Mn (manganese), Cu (copper), Zr (zirconium), Mo (molybdenum), La (lanthanum), and Ir (iridium).

[0196] The metal-containing substance may be any substance containing a metal (metal atom), and examples thereof include a simple substance of metal M, an alloy containing metal M, an oxide of metal M, a nitride of metal M, and an oxynitride of metal M. The metal-containing material may be a mixture containing two or more of these compounds. The oxides, nitrides and oxynitrides may be any of complex oxides, complex nitrides and complex oxynitrides containing a metal. The content of metal atoms in the metal-containing material is preferably 10 mass % or more, more preferably 30 mass % or more, and even more preferably 50 mass % or more, based on the total mass of the metal-containing material. Since the metal-containing material may be the metal itself, the upper limit is preferably 100 mass % or less.

[0197] The semiconductor substrate preferably has a metal M-containing material containing a metal M, more preferably has a metal-containing material containing at least one metal selected from the group consisting of Cu, W, Co, Ti, Ta, Ru, and Mo, further preferably has a metal-containing material containing at least one metal selected from the group consisting of W, Co, Cu, Ti, Ta, and Ru (a tungsten-containing material, a cobalt-containing material, a copper-containing material, a titanium-containing material, a tantalum-containing material, and a ruthenium-containing material), and particularly preferably has a metal-containing material containing at least one metal selected from the group consisting of Co, Cu, and Ru.

[0198] The semiconductor substrate, which is the object to be cleaned with the cleaning liquid, is, for example, a wafer constituting the semiconductor substrate, and has a metal wiring film, a barrier metal, and an insulating film on the surface thereof.

[0199] Examples of wafers that constitute semiconductor substrates include wafers made of silicon-based materials such as silicon (Si) wafers, silicon carbide (SiC) wafers, and resin-based wafers containing silicon (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), antimony (Sb), etc.), and p-type silicon wafers doped with trivalent atoms (e.g., boron (B), gallium (Ga), etc.). Examples of silicon in silicon wafers include amorphous silicon, single crystal silicon, polycrystalline silicon, and 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.

[0200] The semiconductor substrate may have an insulating film on the wafer. Examples of insulating films include silicon oxide films (e.g., silicon dioxide (SiO2) film and tetraethyl orthosilicate (Si(OC2H5)4) film (TEOS film)), silicon nitride films (e.g., silicon nitride (Si3N4) and silicon carbide nitride (SiNC)), and low dielectric constant (Low-k) films (e.g., carbon-doped silicon oxide (SiOC) film and silicon carbide (SiC) film), with low dielectric constant (Low-k) films being preferred.

[0201] The metal-containing material is also preferably a metal film containing a metal. The metal film of the semiconductor substrate is preferably a metal film containing metal M, more preferably a metal film containing at least one metal selected from the group consisting of Cu, W, Co, Ti, Ta, Ru, and Mo, even more preferably a metal film containing at least one metal selected from the group consisting of W, Co, Cu, Ti, Ta, and Ru, particularly preferably a metal film containing at least one metal selected from the group consisting of W, Co, Cu, and Ru, and most preferably a metal film containing Ru metal. Examples of metal films containing at least one metal selected from the group consisting of W, Co, Cu, and Ru include films containing tungsten as a main component (W-containing film), films containing cobalt as a main component (Co-containing film), films containing copper as a main component (Cu-containing film), and films containing ruthenium as a main component (Ru-containing film). The semiconductor substrate preferably has at least one of a metal film containing tungsten and a metal film containing cobalt.

[0202] Examples of ruthenium-containing films include metal films made of ruthenium metal only (ruthenium metal films) and metal films made of alloys of ruthenium metal and other metals (ruthenium alloy metal films). Ruthenium-containing films are often used as barrier metals.

[0203] Examples of tungsten-containing films (metal films containing tungsten as a main component) include metal films made of tungsten alone (tungsten metal films) and metal films made of alloys containing tungsten and other metals (tungsten alloy metal films). Examples of tungsten alloy metal films include tungsten-titanium alloy metal films (WTi alloy metal films) and tungsten-cobalt alloy metal films (WCo alloy metal films). The tungsten-containing film is used, for example, as a barrier metal or in the connection between a via and a wiring.

[0204] Examples of cobalt-containing films (metal films containing cobalt as a main component) include metal films consisting only of metallic cobalt (cobalt metal films) and metal films made of alloys consisting of metallic cobalt and other metals (cobalt alloy metal films). Examples of cobalt alloy metal films include metal films made of an alloy of cobalt and one or more metals selected from titanium (Ti), chromium (Cr), iron (Fe), nickel (Ni), molybdenum (Mo), palladium (Pd), tantalum (Ta), and tungsten (W). More specifically, examples include cobalt-titanium alloy metal films (CoTi alloy metal films), cobalt-chromium alloy metal films (CoCr alloy metal films), cobalt-iron alloy metal films (CoFe alloy metal films), cobalt-nickel alloy metal films (CoNi alloy metal films), cobalt-molybdenum alloy metal films (CoMo alloy metal films), cobalt-palladium alloy metal films (CoPd alloy metal films), cobalt-tantalum alloy metal films (CoTa alloy metal films), and cobalt-tungsten alloy metal films (CoW alloy metal films). The cleaning solution is useful for substrates having a cobalt-containing film, among which cobalt metal films are often used as wiring films and cobalt alloy metal films are often used as barrier metals.

[0205] The semiconductor substrate also preferably has a copper-containing film (a metal film containing copper as a main component). Examples of copper-containing films include wiring films made only of metallic copper (copper wiring films) and wiring films made of alloys of metallic copper and other metals (copper alloy wiring films). Examples of the copper alloy wiring film include a wiring film made of an alloy composed of copper and one or more metals selected from aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), tantalum (Ta), and tungsten (W). More specifically, examples include a copper-aluminum alloy wiring film (CuAl alloy wiring film), a copper-titanium alloy wiring film (CuTi alloy wiring film), a copper-chromium alloy wiring film (CuCr alloy wiring film), a copper-manganese alloy wiring film (CuMn alloy wiring film), a copper-tantalum alloy wiring film (CuTa alloy wiring film), and a copper-tungsten alloy wiring film (CuW alloy wiring film).

[0206] In addition, there may be a case where it is preferable to use the cleaning liquid for cleaning a substrate having at least a copper-containing wiring film and a metal film (cobalt barrier metal) composed only of metal cobalt and serving as a barrier metal for the copper-containing wiring film on the upper part of the wafer constituting the semiconductor substrate, with the copper-containing wiring film and the cobalt barrier metal being in contact with each other on the substrate surface.

[0207] As a method for forming the above-described insulating film, ruthenium-containing film, tungsten-containing film, copper-containing film, and cobalt-containing film on the wafer constituting the semiconductor substrate, there is no particular limitation as long as it is a method commonly used in this field. As a method for forming the insulating film, for example, a silicon oxide film is formed by performing heat treatment on the wafer constituting the semiconductor substrate in the presence of oxygen gas, and then a silicon nitride film is formed by flowing gases of silane and ammonia and using a chemical vapor deposition (CVD) method. As a method for forming the ruthenium-containing film, tungsten-containing film, copper-containing film, and cobalt-containing film, for example, a circuit is formed on the wafer having the above-described insulating film by a known method such as resist, and then the ruthenium-containing film, tungsten-containing film, copper-containing film, and cobalt-containing film are formed by methods such as plating and CVD method.

[0208] <CMP process> CMP processing is a process for planarizing the surface of a substrate having, for example, a metal wiring film, a barrier metal, and an insulating film by a combined action of chemical polishing using a polishing slurry containing polishing particles (abrasive grains) and mechanical polishing. On the surface of a semiconductor substrate that has undergone CMP processing, impurities such as metal impurities (metal residues) derived from the abrasive grains (e.g., silica and alumina) used in the CMP processing, the polished metal wiring film, and the barrier metal may remain. Organic residues derived from the CMP processing solution used during the CMP processing may also remain. These impurities may, for example, cause short circuits between wirings and degrade the electrical characteristics of the semiconductor substrate. Therefore, the semiconductor substrate that has undergone CMP processing is subjected to a cleaning process to remove these impurities from the surface. Examples of semiconductor substrates that have been subjected to CMP include, but are not limited to, substrates that have been subjected to CMP as described in Journal of the Japan Society for Precision Engineering, Vol. 84, No. 3, 2018.

[0209] <Buffing process> The surface of the semiconductor substrate, which is the object to be cleaned with the cleaning liquid, may be subjected to a buffing process after being subjected to a CMP process. Buffing is a process for reducing impurities on the surface of a semiconductor substrate using a polishing pad. Specifically, the surface of a semiconductor substrate that has been subjected to CMP processing is brought into contact with a polishing pad, and the semiconductor substrate and the polishing pad are slid relative to each other while a buffing composition is supplied to the contact area. As a result, impurities on the surface of the semiconductor substrate are removed by the frictional force of the polishing pad and the chemical action of the buffing composition.

[0210] As the buffing composition, a known buffing composition can be appropriately used depending on the type of semiconductor substrate and the type and amount of impurities to be removed. The components contained in the buffing composition include, for example, a water-soluble polymer such as polyvinyl alcohol, water as a dispersion medium, and an acid such as nitric acid. In one embodiment of the buffing treatment, it is preferable to perform the buffing treatment on the semiconductor substrate using the above-mentioned cleaning liquid as the buffing composition. The polishing device and polishing conditions used in the buffing process can be appropriately selected from known devices and conditions depending on the type of semiconductor substrate, the object to be removed, etc. Examples of the buffing process include the processes described in paragraphs

[0085] to

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

[0211] [Method for cleaning semiconductor substrates] The method for cleaning a semiconductor substrate is not particularly limited as long as it includes a cleaning step of cleaning a semiconductor substrate that has been subjected to CMP treatment using the above cleaning solution. The method for cleaning a semiconductor substrate preferably includes a step of applying the diluted cleaning solution obtained in the above dilution step to a semiconductor substrate that has been subjected to CMP treatment to clean the substrate.

[0212] The cleaning step of cleaning a semiconductor substrate using a cleaning liquid may be any known method performed on a CMP-treated semiconductor substrate, such as scrubbing, in which a cleaning member such as a brush is brought into physical contact with the surface of the semiconductor substrate while the cleaning liquid is supplied to the semiconductor substrate to remove residues, an immersion method in which the semiconductor substrate is immersed in the cleaning liquid, a spin (drop) method in which the cleaning liquid is dropped onto the rotating semiconductor substrate, or a spray (spray) method in which the cleaning liquid is sprayed. In immersion cleaning, it is preferable to ultrasonically treat the cleaning liquid in which the semiconductor substrate is immersed, as this can further reduce impurities remaining on the surface of the semiconductor substrate. The washing step may be carried out once or twice or more times. When washing twice or more times, the same method may be repeated or different methods may be combined.

[0213] The semiconductor substrate may be cleaned by either a single wafer method or a batch method. The single wafer method generally refers to a method in which semiconductor substrates are processed one by one, while the batch method generally refers to a method in which multiple semiconductor substrates are processed simultaneously.

[0214] The temperature of the cleaning solution used to clean semiconductor substrates is not particularly limited as long as it is a temperature commonly used in this field. Cleaning is generally performed at room temperature (about 25°C), but the temperature can be selected arbitrarily to improve cleaning properties and minimize damage to components. For example, the temperature of the cleaning solution is preferably 10 to 60°C, and more preferably 15 to 50°C.

[0215] The pH of the cleaning solution is preferably in the preferred pH range described above, and the pH of the diluted cleaning solution is also preferably in the preferred pH range described above.

[0216] The cleaning time for cleaning a semiconductor substrate can be appropriately changed depending on the type and content of components contained in the cleaning solution, etc. In practice, it is preferably 10 seconds to 2 minutes, more preferably 20 seconds to 1 minute 30 seconds, and even more preferably 30 seconds to 1 minute.

[0217] The supply amount (supply rate) of the cleaning liquid in the step of cleaning the semiconductor substrate is preferably 50 to 5000 mL / min, more preferably 500 to 2000 mL / min.

[0218] In cleaning semiconductor substrates, mechanical agitation may be used to further enhance the cleaning ability of the cleaning solution. Examples of mechanical stirring methods include a method of circulating the cleaning liquid over the semiconductor substrate, a method of passing or spraying the cleaning liquid over the semiconductor substrate, and a method of stirring the cleaning liquid by ultrasonic waves or megasonics.

[0219] After the above-described cleaning of the semiconductor substrate, a step of rinsing and cleaning the semiconductor substrate with a solvent (hereinafter also referred to as a "rinsing step") may be carried out. The rinsing step is preferably carried out continuously after the cleaning step of the semiconductor substrate, and is a step of rinsing with a rinsing solvent (rinsing liquid) for 5 seconds to 5 minutes. The rinsing step may be carried out using the mechanical stirring method described above.

[0220] Rinse solvents include, for example, water (preferably deionized (DI) water), methanol, ethanol, isopropyl alcohol, 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 dilute aqueous ammonium hydroxide) may also be used. As a method for contacting the rinsing solvent with the semiconductor substrate, the above-mentioned method for contacting the cleaning liquid with the semiconductor substrate can be similarly applied.

[0221] After the rinsing step, a drying step of drying the semiconductor substrate may be carried out. Examples of drying methods include spin drying, flowing a dry gas over the semiconductor substrate, heating the substrate with a heating means such as a hot plate or an infrared lamp, Marangoni drying, Rotagoni drying, IPA (isopropyl alcohol) drying, and any combination of these methods. [Example]

[0222] The present invention will be described in more detail below with reference to examples. The materials, amounts used, and ratios 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 examples shown below.

[0223] In the following examples, the pH of the cleaning solution was measured at 25° C. using a pH meter (manufactured by Horiba Ltd., model "F-74") in accordance with JIS Z8802-1984. In addition, in producing the cleaning solutions of the Examples and Comparative Examples, handling of containers, preparation of the cleaning solutions, filling, storage, and analytical measurements were all carried out in a clean room meeting ISO class 2 or lower.

[0224] [Cleaning solution ingredients] The following compounds were used to prepare the cleaning solution. Note that all of the components used in the examples were classified as semiconductor grade or equivalent high purity grade.

[0225] [Purine compounds] Xanthine Adenosine Adenine Guanine Hypoxanthine ·uric acid Pudding Caffeine Isoguanine Theobromine Theophylline

[0226] [Compound A] MDEA: N-methyldiethanolamine t-BDEA: N-tert-butyldiethanolamine Bis-HEAP: 1-[bis(2-hydroxyethyl)amino]-2-propanol Ph-DEA: N-phenyldiethanolamine EDEA: N-ethyldiethanolamine BDEA: N-butyldiethanolamine N-MEA: N-methylethanolamine DMAE: 2-(dimethylamino)ethanol DMAMP: 2-(dimethylamino)-2-methyl-1-propanol MAMP: (2-methyl-2(methylamino)propan-1-ol

[0227] [Quaternary ammonium compounds] Tris: Tris(2-hydroxyethyl)methylammonium hydroxide Choline: 2-hydroxyethyltrimethylammonium hydroxide ETMAH: Ethyltrimethylammonium hydroxide

[0228] [Organic acid] ·Tartaric acid Citric acid Malonic acid Succinic acid EDTPO: Ethylenediaminetetra(methylenephosphonic acid) HEDPO: 1-hydroxyethylidene-1,1'-diphosphonic acid

[0229] [Other additives] MEA: Monoethanolamine Polyacrylic acid (Mw=700,000): Toagosei Co., Ltd., product name "Jurimer AC-10H" Polyacrylic acid (Mw=55,000): Toagosei Co., Ltd., product name "Jurimer AC-10L" Polyacrylic acid (Mw=6,000): Aron A-10SL, manufactured by Toagosei Co., Ltd. Polymaleic acid (Mw=2,000): NOF Corporation, product name "Non-Pol PWA-50W" Styrene-maleic acid copolymer: Daiichi Kogyo Seiyaku Co., Ltd., product name "DKS Discoat N-10" Styrene-maleic acid half ester copolymer: Daiichi Kogyo Seiyaku Co., Ltd., product name "DKS Discoat N-14" Naphthalenesulfonic acid formalin condensate sodium salt: Daiichi Kogyo Seiyaku Co., Ltd., product name "Labelin FD-40" 1,2,4-triazole 1,2,3-triazole Nonionic X: The compounds shown below

[0230] [ka]

[0231] Cysteine Thioglycerol 3-Mercapto-1,2,4-triazole Polyethylene glycol Iodic acid Periodic acid Morpholine (pKa 8.006) Tetramethylguanidine: 1,1,3,3-tetramethylguanidine (pKa 13.6) DABCO: 1,4-diazabicyclo[2.2.2]octane (pKa 8.7) DBU: Diazabicycloundecene (pKa 13.28) DBN: Diazabicyclononene (pKa 13.42) PMDTA: N,N,N',N'',N''-pentamethyldiethylenetriamine 2-(2-aminoethylamino)ethanol Hydrazine AMP: 2-amino-2-methyl-1-propanol TMED: Tetramethylethylenediamine

[0232] [pH adjuster, ultrapure water] In addition, in the manufacturing process of the cleaning solution in this example, the pH was adjusted to the pH shown in the table using either potassium hydroxide (KOH) or sulfuric acid (H2SO4) as a pH adjuster, and commercially available ultrapure water (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). The content of the pH adjuster (potassium hydroxide or sulfuric acid) in the cleaning liquid of any of the Examples and Comparative Examples was 2 mass % or less relative to the total mass of the cleaning liquid. In the cleaning solution, the remaining components (remainder) that are not the components specified as cleaning solution components in the table and are not the pH adjusters are ultrapure water.

[0233] [Cleaning solution manufacturing] Next, a method for producing a cleaning liquid will be described using Example 1 as an example. Xanthine, MEDA, Tris, and tartaric acid were added to ultrapure water in amounts that would result in the final cleaning solution having the composition shown in the table below, and then a pH adjuster was added so that the pH of the cleaning solution prepared was 12.5. The resulting mixture was thoroughly stirred to obtain the cleaning solution of Example 1.

[0234] According to the manufacturing method of Example 1, cleaning solutions of each Example or Comparative Example having the compositions shown in the table below were manufactured.

[0235] [Evaluation of cleaning performance (organic residue)] The cleaning solution produced by the above method was used to evaluate the cleaning performance (organic residues) when cleaning a metal film that had been subjected to chemical mechanical polishing. In the tests of each Example and Comparative Example, 1 mL of the cleaning solution of each Example and Comparative Example was taken and diluted 100 times in volume with ultrapure water to prepare a sample of diluted cleaning solution. The polishing was performed using a FREX300S-II (polishing machine, manufactured by Ebara Corporation) and BSL8872 (trade name, manufactured by Fujifilm Electronic Materials Co., Ltd.) as the polishing solution. The polishing pressure was 2.0 psi and the polishing solution supply rate was 0.28 mL / (min cm 2 A wafer (12 inches in diameter) having a BD1 film (Low-K film) on its surface was polished under the conditions of 1000 kJ / cm 2 , 1000 kJ / cm 3 , and 60 seconds of polishing time. The wafers were then scrubbed for 60 minutes using samples of each diluted cleaning solution adjusted to room temperature (23°C) and then dried. Using a defect detection system (AMAT, ComPlus-II), the number of defects detected on the polished surface of the wafers with a length of more than 0.1 μm was counted, and each defect was observed with a scanning electron microscope (SEM). If necessary, the constituent elements were identified using an energy dispersive X-ray analyzer (EDX). This allowed the number of defects due to organic residues (residues containing organic substances as the main component) on the polished surface of the wafer to be determined. A: The number of target defects is 20 or less B: The number of target defects is more than 20 and less than 30 C: The number of target defects is more than 30 and less than 40 D: The number of target defects is more than 40 and less than 50 E: The number of target defects is more than 50

[0236] The pH of the diluted cleaning liquids of Examples 1 to 40 and 45 to 90 after dilution to 100 times their volume was 11.0. Furthermore, in the state of diluted cleaning solutions after diluting the cleaning solutions of Examples 41 to 44 by 100 times their volume, the pH of the cleaning solution of Example 41 was 8.2, the pH of the cleaning solution of Example 42 was 9.8, the pH of the cleaning solution of Example 43 was 10.5, and the pH of the cleaning solution of Example 44 was 11.4. The pH of the diluted cleaning solutions of Examples 95 to 104, 113, 114, 116, and 117 after dilution to 100 times their volume was 11.0. Furthermore, the pH of the diluted cleaning solutions of Examples 105 to 112, 115, and 118 after dilution to 100 times their volume was 10.8.

[0237] [Evaluation of ruthenium oxide dissolving ability] A 2x2 cm ruthenium oxide coupon wafer was prepared. The wafers were placed in a container filled with the cleaning solution of each Example or Comparative Example and immersed for 30 minutes at room temperature (25° C.). Thereafter, the film thickness of the resulting wafer was measured, and the etching rate (Å / min) was calculated from the difference in film thickness before and after the immersion treatment and evaluated according to the following evaluation criteria. A: 5Å / min or more B: 3Å / min or more and less than 5Å / min C: 2Å / min or more and less than 3Å / min D: 1Å / min or more and less than 2Å / min E: Less than 1Å / min

[0238] [result] In the table, the column "Content (mass %)" indicates the content (mass %) of each component relative to the total mass of the cleaning liquid. The column "Solid content concentration (mass %)" indicates the content (mass %) of each component relative to the total mass of the components in the cleaning liquid excluding the solvent. The column "(B) / (A)" indicates the mass ratio of the content of purine compound (B) to the content of compound A (A) (content of purine compound (B) / content of compound A (A)). The values ​​in the "Pre-dilution pH" column indicate the pH of the undiluted cleaning solution (before 100-fold dilution) at 25°C, as measured using the pH meter described above. In other words, they indicate the pH of the undiluted cleaning solution.

[0239] [Table 1]

[0240] [Table 2]

[0241] [Table 3]

[0242] [Table 4]

[0243] [Table 5]

[0244] From the above table, it was confirmed that the cleaning solution of the present invention has excellent cleaning performance and also has excellent ability to dissolve ruthenium oxide. It was confirmed that cleaning performance was better when the purine compound contained at least one selected from the group consisting of xanthine, hypoxanthine, uric acid, purine, caffeine, and theophylline, and that cleaning performance was even better when the purine compound contained at least one selected from the group consisting of xanthine and hypoxanthine (comparison of Examples 1 to 10 and 99 to 102).Furthermore, from a similar comparison, it was confirmed that cleaning performance was even better when the purine compound contained at least one selected from the group consisting of compounds represented by formulas (B5) to (B6). It was confirmed that the cleaning performance was better when the content of purine compounds was 0.5 to 30.0 mass% relative to the total mass of the components excluding the solvent in the cleaning solution (comparison of Examples 1 and 11 to 14 with Example 15, comparison of Examples 5 and 16 with Example 17, comparison of Examples 10 and 18 with Example 19, comparison of Examples 7 and 20 with Example 21). It was confirmed that when compound A contains at least one selected from the group consisting of MDEA, t-BDEA, Ph-DEA, EDEA, and N-MEA, the ability to dissolve ruthenium oxide is superior, and when the purine compound contains MDEA, the ability to dissolve ruthenium oxide is even superior (comparison between Examples 1 and 22 to 28). It was confirmed that the effects of the present invention are better when the content of the compound represented by formula (A) is 3.0 to 40.0 mass % relative to the total mass of the components excluding the solvent from the cleaning liquid for semiconductor substrates (comparison of Examples 1, 29 to 33 and 52). It was confirmed that the effects of the present invention were more excellent when the pH of the cleaning solution (before dilution) was 9.5 to 13.0 (comparison between Examples 1 and 41 to 44). It was confirmed that the effects of the present invention were superior when the mass ratio of the purine compound content to the compound A content was 0.02 to 20.0, and that the ruthenium oxide dissolving ability was even superior when the mass ratio of the purine compound content to the compound A content was 0.05 to 10.0 (comparison of Examples 1, 11 to 14, 30 to 33, 47 and 48). It was confirmed that the effects of the present invention are better when the cleaning solution contains an amine compound with a pKa of 8.5 or higher, and that the ability to dissolve ruthenium oxide is even better when the cleaning solution contains at least one compound selected from the group consisting of guanidine, guanidine derivatives, and cyclic amidine compounds (comparison of Examples 73 to 80). It was confirmed that when the cleaning liquid contained an aliphatic tertiary amine compound, the cleaning performance was superior (comparison of Examples 83 to 88, 89 and 90). Furthermore, similar comparisons confirmed that when the cleaning solution contained N,N,N',N'',N''-pentamethyldiethylenetriamine, the cleaning performance was even better (comparison of Examples 99, 100, 103 and 104). It was confirmed that the effects of the present invention were more excellent when the cleaning liquid contained 2-(dimethylamino)-2-methyl-1-propanol as the main component (comparison of Examples 95 to 112).< / ph>

Claims

1. A semiconductor substrate cleaning solution used for cleaning a semiconductor substrate, at least one purine compound selected from the group consisting of purines and purine derivatives; and a compound represented by formula (A), the content of the purine compound is 0.5 to 30.0 mass% based on the total mass of the components excluding the solvent of the semiconductor substrate cleaning solution, The cleaning solution for semiconductor substrates further comprises an aliphatic tertiary amine compound which is a compound different from the compound represented by formula (A). 【Chemical 1】 In formula (A), R ａ１ represents an alkyl group which may have a hydroxyl group. ａ２ represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent. ａ３ represents an alkylene group which may have an oxygen atom.

2. 2. The cleaning solution for semiconductor substrates according to claim 1, wherein the purine compound comprises at least one selected from the group consisting of compounds represented by formulas (B5) to (B6): 【Chemistry 2】 In formula (B5), R １５ and R １７ R each independently represents a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent. １６ represents a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent. In formula (B6), R １８ ~R ２０ each independently represents a hydrogen atom, 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 polyoxyalkylene group-containing group which may have a substituent.

3. 2. The cleaning solution for a semiconductor substrate according to claim 1, wherein the purine compound comprises at least one selected from the group consisting of xanthine, adenine, guanine, hypoxanthine, uric acid, purine, caffeine, isoguanine, theobromine, theophylline, and paraxanthine.

4. 4. The cleaning solution for a semiconductor substrate according to claim 1, wherein the purine compound comprises at least one selected from the group consisting of xanthine and hypoxanthine.

5. 5. The cleaning solution for a semiconductor substrate according to claim 1, wherein the compound represented by formula (A) includes a compound represented by formula (A1): 【Chemistry 3】 In formula (A1), R ａ４ represents an alkylene group which may have an oxygen atom. ａ６ represents an alkylene group. ａ５ represents an alkyl group having 1 to 5 carbon atoms which may have a substituent, a phenyl group, or a hydrogen atom.

6. 6. The cleaning solution for semiconductor substrates according to claim 1, wherein the compound represented by formula (A) comprises N-methyldiethanolamine.

7. 7. The cleaning solution for a semiconductor substrate according to claim 1, wherein the content of the compound represented by formula (A) is 3.0 to 40.0 mass % based on the total mass of the components excluding the solvent from the cleaning solution for a semiconductor substrate.

8. 8. The cleaning solution for semiconductor substrates according to claim 1, wherein a mass ratio of the content of the purine compound to the content of the compound represented by formula (A) is 0.02 to 20.

0.

9. 9. The cleaning solution for semiconductor substrates according to claim 1, wherein the pH is 9.5 to 13.

0.

10. The cleaning solution for semiconductor substrates according to any one of claims 1 to 9, further comprising an organic acid.

11. The cleaning solution for a semiconductor substrate according to claim 10 , wherein the organic acid comprises a compound represented by formula (D): 【Chemistry 4】 In formula (D), L ｄ represents a single bond or a divalent linking group.

12. The cleaning solution for semiconductor substrates according to any one of claims 1 to 11, further comprising a quaternary ammonium compound.

13. The cleaning solution for a semiconductor substrate according to claim 12 , wherein the quaternary ammonium compound comprises a compound represented by formula (C): 【Chemistry 5】 In formula (C), R ｃ１ ~R ｃ４ each independently represents a hydrocarbon group which may have a substituent, provided that all R ｃ１ ~R ｃ４ and X represent the same group. － represents an anion.

14. 14. The cleaning solution for semiconductor substrates according to claim 12, wherein the quaternary ammonium compound comprises tris(2-hydroxyethyl)methylammonium hydroxide.

15. 15. The cleaning solution for semiconductor substrates according to claim 1, wherein the aliphatic tertiary amine compound has two or more nitrogen atoms.

16. The cleaning solution for semiconductor substrates according to claim 5, wherein R a5 represents an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a hydrogen atom.

17. The cleaning solution for semiconductor substrates according to claim 12 or 13, wherein the quaternary ammonium compound comprises 2-hydroxyethyltrimethylammonium hydroxide.

Images