Cleaning liquid for semiconductor substrate, method for cleaning object to be processed, and method for manufacturing semiconductor device

Abstract

Provided is a cleaning liquid which is for a semiconductor substrate, and which, when applied to an object to be processed having a copper surface and a silicon carbonitride surface that have been subjected to chemical mechanical polishing treatment, has excellent cleaning properties on the copper surface and the silicon carbonitride surface and exhibits reduced copper corrosion. A cleaning liquid for a semiconductor substrate according to the present invention comprises: a compound represented by formula (A); and a polymer having a group selected from the group consisting of a carboxy group and a salt thereof a sulfonic acid group and a salt thereof, wherein the cleaning liquid has a pH of 7.5 or more.

Description

Cleaning solution for semiconductor substrates, cleaning method for objects, and manufacturing method for semiconductor devices

[0001] The present invention relates to a cleaning liquid for semiconductor substrates, a method for cleaning an object, and a method for manufacturing a semiconductor device.

[0002] Semiconductor devices are manufactured by forming a resist film on a laminate having a metal film, an etching stop layer, and an interlayer insulating layer on a substrate, and then performing a photolithography process. In the photolithography process, a method of etching or removing foreign matter from the substrate surface using a treatment liquid that dissolves metals and / or organic substances is widely known.

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

[0004] As a treatment liquid used in the cleaning step, for example, Patent Document 1 discloses a "cleaning composition containing one or more quaternary ammonium hydroxides, one or more organic amines, one or more metal inhibitors, and water" as a composition for cleaning contaminants from semiconductor wafers after chemical mechanical polishing.

[0005] Special table 2018-507540 publication

[0006] The present inventors have investigated the cleaning properties (e.g., the ability to remove organic residues) of copper surfaces and silicon carbonitride surfaces on objects after CMP treatment using the post-CMP cleaning composition described in Patent Document 1, and have found that it is difficult to achieve both cleaning properties for copper surfaces and silicon carbonitride surfaces and inhibition of corrosion of the copper surface.

[0007] Therefore, an object of the present invention is to provide a semiconductor substrate cleaning solution that, when applied to an object having a copper surface or a silicon carbonitride surface that has been subjected to chemical mechanical polishing, has excellent cleaning properties for the copper surface and the silicon carbonitride surface and causes little corrosion of the copper. Another object of the present invention is to provide a method for cleaning an object using the semiconductor substrate cleaning solution, and a method for manufacturing a semiconductor device.

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

[0009] [1] A cleaning solution for semiconductor substrates, comprising a compound represented by the formula (A) described below and a polymer having a group selected from the group consisting of a carboxy group and a salt thereof, and a sulfonic acid group and a salt thereof, and having a pH of 7.5 or more. [2] R ５ and R ６ [3] The cleaning solution for semiconductor substrates according to [1], wherein R １ ~R ８ each independently represents an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, or a hydroxy group, or a hydrogen atom; R １ ~R ４ [4] The cleaning solution for semiconductor substrates according to [1] or [2], wherein at least one of R represents an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, a hydroxy group, and an amino group. １ and R ２ is a hydrogen atom, and R ３ and R ４

[0023] The cleaning solution for a semiconductor substrate according to any one of [1] to [3], wherein at least one of the groups represented by the formula (A) and the formula (B) is an alkyl group which may have a substituent other than a carboxy group and a phosphonic acid group. [5] The cleaning solution for a semiconductor substrate according to any one of [1] to [4], wherein the polymer has a weight-average molecular weight of 4,000 or more. [6] The cleaning solution for a semiconductor substrate according to any one of [1] to [5], wherein the pH is 10.0 or more. [7] The cleaning solution for a semiconductor substrate according to any one of [1] to [6], wherein the pH is 11.0 or more. [8] The cleaning solution for a semiconductor substrate according to any one of [1] to [7], further comprising a corrosion inhibitor. [9] The cleaning solution for a semiconductor substrate according to [8], wherein the corrosion inhibitor comprises at least one of a compound represented by formula (C) described below and a compound represented by formula (D) described below.

[10] The cleaning solution for a semiconductor substrate according to any one of [1] to [9], wherein the ClogP value of the compound represented by formula (A) is a negative value.

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

[10] , wherein the compound represented by formula (A) has 5 or less carbon atoms.

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

[11] , comprising water.

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

[12] , which is used for cleaning an object that has been subjected to chemical mechanical polishing.

[14] The cleaning solution for semiconductor substrates according to

[13] , wherein the object has a copper surface and a silicon carbonitride surface that have been subjected to chemical mechanical polishing, and the cleaning solution is used for cleaning the copper surface and the silicon carbonitride surface.

[15] A method for cleaning an object, comprising the step of contacting an object having a copper surface and a silicon carbonitride surface that have been subjected to chemical mechanical polishing with the cleaning solution for semiconductor substrates according to any one of [1] to

[14] .

[16] The method for cleaning an object according to

[15] , wherein the step is any one of cleaning using a polishing pad, buff cleaning, cleaning by immersion, spin cleaning, and scrub cleaning.

[17] A method for manufacturing a semiconductor device, comprising the method for cleaning an object according to

[15] or

[16] .

[0010] According to the present invention, there is provided a semiconductor substrate cleaning solution that, when applied to an object having a copper surface or a silicon carbonitride surface that has been subjected to chemical mechanical polishing, has excellent cleaning properties for the copper surface and the silicon carbonitride surface and causes little corrosion of the copper. Furthermore, there are also provided a method for cleaning an object using the semiconductor substrate cleaning solution and a method for manufacturing a semiconductor device.

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

[0012] The following describes the meaning of each description in this specification.

[0013] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. In this specification, "total solid content" means the total mass of all components contained in the cleaning solution other than water and solvents such as organic solvents. In this specification, when two or more types of a certain component are present, the "content" of that component means the total content of those two or more components. Unless otherwise specified, the compounds described in this specification may contain structural isomers, optical isomers, and isotopes. Furthermore, structural isomers, optical isomers, and isotopes may be contained alone or in combination.

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

[0015] In this specification, the ClogP value refers to a value obtained by calculating the common logarithm logP of the partition coefficient P between 1-octanol and water. Known methods and software can be used to calculate the ClogP value, and known literature values ​​(for example, values ​​reported on websites such as http: / / www.chemspider.com) may be used. Unless otherwise specified, in the present invention, structures are drawn using ChemDraw Professional (version 20.1.1) manufactured by PerkinElmer, and values ​​calculated using the above software are used.

[0016] In this specification, "(meth)acrylic" is a generic term including acrylic and methacrylic, and means "at least one of acrylic and methacrylic." Similarly, "(meth)acrylic acid" means "at least one of acrylic acid and methacrylic acid."

[0017] In this specification, unless otherwise specified, the molecular weight of a compound having a molecular weight distribution is a weight average molecular weight. In this specification, when the polymer used is a commercially available product and catalog values ​​(nominal values ​​from the manufacturer) are available for the weight average molecular weight (Mw), number average molecular weight (Mn), and polydispersity (also called molecular weight distribution) (Mw / Mn) of the polymer, the catalog values ​​are used. When catalog values ​​are not available or when the weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity (Mw / Mn) of a polymer are determined by measurement, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity (Mw / Mn) are measured by Gel Permeation Chromatography (GPC) using a Prominence UFLC (Shimadzu Corporation) (eluent: phosphate buffer (pH = 7) and acetonitrile in a volume ratio of 9:1, flow rate (sample injection amount): 50 μL, column: TSK guard column α + TSK gel α-6000 + TSK gel α-3000 (Tosoh Corporation), column temperature: 40°C, flow rate: 1.0 mL / min, detector: differential refractive index detector (Refractive Index Detector)). The above description of "TSK guard column α + TSK gel α-6000 + TSK gel α-3000" indicates that the above three columns were used in conjunction with each other.

[0018] In this specification, "ppm" means "parts-per-million (10 －６ ) and "ppb" stands for "parts-per-billion (10 －９ In this specification, 1 Å (angstrom) corresponds to 0.1 nm.

[0019] [Cleaning Solution] The cleaning solution of the present invention is a cleaning solution for semiconductor substrates, which contains a compound represented by formula (A) described below and a polymer having a group selected from the group consisting of a carboxy group and its salt, and a sulfonic acid group and its salt (hereinafter also referred to as a "specific polymer"), and has a pH of 7.5 or higher. The mechanism by which the problem of the present invention can be solved by the cleaning solution of the present invention having the above-mentioned configuration is not necessarily clear, but the inventors speculate as follows. Note that the following speculation does not limit the mechanism by which the effect is obtained. In other words, even if the effect is obtained by a mechanism other than the one described below, it is still included in the scope of the present invention.

[0020] After chemical mechanical polishing (CMP), organic residues, such as aggregates formed by complexing components contained in the CMP slurry with copper produced by polishing, remain on the copper surface. The compound represented by formula (A) is capable of dispersing these aggregates, facilitating the transfer of the organic residues to the cleaning solution. Furthermore, since both silicon carbonitride (SiCN) surfaces and organic residues are hydrophobic, the organic residues are difficult to remove. However, the polymer containing carboxyl or sulfonic acid groups as hydrophilic moieties effectively inhibits the reattachment of organic residues to the SiCN surface. Furthermore, although the detailed mechanism is unclear, the inventors have also discovered that the polymer containing carboxyl and sulfonic acid groups reduces copper corrosion. As a result, it is believed that the cleaning solution of the present invention, when applied to objects having copper and silicon carbonitride surfaces that have been subjected to chemical mechanical polishing, exhibits excellent cleaning properties for copper and silicon carbonitride surfaces and reduces copper corrosion.

[0021] Each component contained in the cleaning solution of the present invention will be described in detail below. In this specification, the term "excellent effect of the present invention" refers to the fact that, when the cleaning solution is applied to an object having a copper surface and a silicon carbonitride surface that have been subjected to chemical mechanical polishing, at least one of the effects of excellent cleaning ability for copper surfaces, excellent cleaning ability for silicon carbonitride surfaces, and reduced copper corrosion is obtained.

[0022] [Compound Represented by Formula (A)] The cleaning solution of the present invention contains a compound represented by formula (A) described below. After CMP treatment, a large amount of aggregates of copper and a corrosion inhibitor (e.g., benzotriazoles) derived from the CMP slurry are present on the copper surface as organic residues. However, the compound represented by formula (A) in the cleaning solution displaces the corrosion inhibitor coordinated to copper, thereby eliminating the aggregates and promoting the dissolution of the organic residues into the cleaning solution. In other words, the inclusion of the compound represented by formula (A) provides the cleaning solution with excellent detergency for copper surfaces.

[0023] The number of carbon atoms in the compound represented by formula (A) is preferably 2 to 10, more preferably 2 to 6, and even more preferably 2 to 5. The ClogP value of the compound represented by formula (A) is preferably −5.00 to 1.00, more preferably −2.00 to −0.01, and even more preferably −1.50 to −0.10. In particular, the ClogP value is preferably a negative value. When the ClogP value of the compound represented by formula (A) is a negative value, the compound represented by formula (A) becomes more hydrophilic when coordinated to copper, as described above, and the cleaning ability of the cleaning liquid for copper surfaces is more excellent.

[0024] The structure of formula (A) is as follows:

[0025]

[0026] In formula (A), R １ ~R ８ each independently represents an alkyl group which may have a substituent other than a carboxy group or a phosphonic acid group, or a hydrogen atom. １ ~R ４At least one of represents an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, and an amino group. The number of carbon atoms in the alkyl group is preferably 1 to 30, more preferably 1 to 15, and even more preferably 1 to 6. The number of carbon atoms in the alkyl group does not include the number of carbon atoms in the substituent. Examples of substituents other than a carboxy group and a phosphonic acid group include halogen atoms such as a fluorine atom, a chlorine atom, and a bromine atom; an alkoxy group; an acyl group such as an acetyl group, a propionyl group, and a benzoyl group; a cyano group; and a nitro group. The substituent other than a carboxy group and a phosphonic acid group may be an amino group. Examples of the amino group include -NR Ｎ ２ (R Ｎ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. The number of substituents that the alkyl group may have is preferably 0 to 5, more preferably 0 to 3, and even more preferably 0.

[0027] The substituent that the alkyl group may have is, as described above, a substituent other than a carboxy group and a phosphonic acid group, and is preferably a substituent other than a carboxy group, a phosphonic acid group, and a hydroxy group. １ ~R ８ each independently represents an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, or a hydroxy group, or a hydrogen atom; R １ ~R ４ At least one of the groups preferably represents an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, a hydroxy group, and an amino group.

[0028] R １ ~R ８ Among them, R ５ and R ６ are preferably all hydrogen atoms, and R ５ ~R ８ It is more preferable that all of R are hydrogen atoms. １ ~R ４ At least one of R represents an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, and an amino group.１ ~R ４ It is preferred that one or two of R represent an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, and an amino group. １ and R ２ is preferably a hydrogen atom. ３ and R ４ At least one of R is preferably an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, or an amino group, ３ and R ４ It is more preferable that one of the groups is an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, or an amino group, and the other is a hydrogen atom.

[0029] As mentioned above, R １ ~R ４ When at least one of R represents an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, a hydroxy group, and an amino group, R １ ~R ４ It is preferred that one or two of R represent an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, a hydroxy group, and an amino group. More specifically, R １ and R ２ is preferably a hydrogen atom. ３ and R ４ At least one of R is preferably an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, a hydroxy group, and an amino group, ３ and R ４ It is more preferable that one of the groups is an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, a hydroxy group, or an amino group, and the other is a hydrogen atom.

[0030] Among them, R １ and R ２ is a hydrogen atom, and R ３ and R ４It is preferable that at least one of R is an alkyl group which may have a substituent other than a carboxy group or a phosphonic acid group (more preferably, an alkyl group which has no substituent). １ and R ２ When R is a hydrogen atom, the compound represented by formula (A) is easily coordinated to copper as described above, and the cleaning ability of the cleaning liquid for the copper surface is more excellent. ３ and R ４ When at least one of the groups is an alkyl group which may have a substituent other than a carboxy group and a phosphonic acid group, the effect of the compound represented by formula (A) on corroding a copper surface of a target object which has been subjected to chemical mechanical polishing can be reduced.

[0031] In formula (A), R ３ and R ７ may be bonded to each other via a single bond or a divalent linking group to form a ring, and R １ and R ３ may be linked via a single bond or a divalent linking group to form a ring, but it is preferred that the compound represented by formula (A) does not form a ring.

[0032] Examples of the divalent linking group include divalent hydrocarbon groups (e.g., divalent aliphatic hydrocarbon groups such as alkylene groups (preferably having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms), alkenylene groups (preferably having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms), and alkynylene groups (preferably having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms), and divalent aromatic hydrocarbon ring groups such as arylene groups), divalent heterocyclic groups, -O-, -S-, -SO ２ -, -NH-, -N(Q)-, -CO-, or a group formed by combining these (for example, -O-divalent hydrocarbon group-, -(O-divalent hydrocarbon group) ｍ -O- (where m is an integer of 1 or more), and a divalent hydrocarbon group -O-CO-. Q represents a hydrogen atom or an alkyl group. R ３ and R ７ , and R １ and R ３When the ring is formed, the number of atoms forming the ring is preferably 3 to 20, more preferably 3 to 10, and even more preferably 5 or 6.

[0033] R ３ and R ７ , and R １ and R ３ The ring formed by bonding is preferably a nitrogen-containing alicyclic structure. The number of ring atoms in the ring is preferably 3 to 8, more preferably 5 or 6. Specific examples of the ring include piperidine and its derivatives, and piperazine and its derivatives.

[0034] The molecular weight of the compound represented by formula (A) is preferably 50 to 500, more preferably 50 to 300, even more preferably 50 to 200, and particularly preferably 50 to 100.

[0035] The compound represented by formula (A) may be used alone or in combination of two or more. The content of the compound represented by formula (A) is preferably 0.0001 to 10.0 mass%, more preferably 0.0001 to 1.0 mass%, and even more preferably 0.001 to 1.0 mass%, relative to the total mass of the cleaning solution. The mass ratio of the content of the compound represented by formula (A) relative to the total solid content of the cleaning solution is preferably 0.001 to 10.0, more preferably 0.001 to 1.0, and even more preferably 0.01 to 1.0.

[0036] [Specific Polymer] The cleaning solution of the present invention contains a polymer (specific polymer) having a group selected from the group consisting of a carboxyl group and its salt, and a sulfonic acid group and its salt. The specific polymer preferably has a hydrophilic moiety and a hydrophobic moiety (e.g., a moiety derived from the main chain) derived from a group selected from the group consisting of a carboxyl group and its salt, and a sulfonic acid group and its salt (hereinafter also referred to as an "anionic functional group"). When the specific polymer has a hydrophilic moiety and a hydrophobic moiety, when the cleaning solution of the present invention is applied to an object having a copper (Cu) surface and a silicon carbonitride (SiCN) surface that has been subjected to chemical mechanical polishing, the silicon carbonitride surface is hydrophobic, but by covering the surface with the specific polymer, the surface becomes hydrophilic, which is thought to have the effect of suppressing the re-adhesion of hydrophobic organic residues removed from the silicon carbonitride surface. Furthermore, the specific polymer having anionic functional groups rather than cationic functional groups can reduce copper corrosion.

[0037] The specific polymer is preferably a polymer containing a repeating unit having an anionic functional group (hereinafter also referred to as "repeating unit A"). As will be described in detail later, the specific polymer may have a repeating unit other than the repeating unit A, but is preferably a polymer consisting only of the repeating unit A. The specific polymer may have two or more types of repeating unit A.

[0038] <Repeating Unit A> The repeating unit A is a repeating unit having a group (anionic functional group) selected from the group consisting of a carboxy group and its salt, and a sulfonic acid group and its salt. Examples of salts of the carboxy group and the sulfonic acid group include ammonium salt, potassium salt, sodium salt, and lithium salt. The number of acid groups or salts thereof contained in the repeating unit A is not particularly limited, but is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2.

[0039] In terms of achieving better effects of the present invention, the specific polymer is preferably a polymer consisting only of repeating units A selected from the group consisting of repeating units having a carboxy group or a salt thereof and repeating units having a sulfonic acid group or a salt thereof, and more preferably a polymer consisting only of repeating units A having a carboxy group or a salt thereof or a polymer consisting only of repeating units A having a sulfonic acid group or a salt thereof.

[0040] Examples of the repeating unit A include repeating units derived from a compound having an anionic functional group and an ethylenically unsaturated group. Specific examples of the anionic functional group are as described above. The ethylenically unsaturated group is a functional group having an ethylenically unsaturated bond. Examples of the ethylenically unsaturated group include an aromatic vinyl group, an acryloyloxy group (CH ２ ═CH—COO—), methacryloyloxy group (CH ２ = CCH ３ -COO-), acrylamide group (CH ２ ═CH—CONH—), methacrylamide group (CH ２ = CCH ３ Examples of the ethylenically unsaturated group include an aromatic vinyl group, an acryloyloxy group, a methacryloyloxy group, an acrylamide group, and a vinyl group. Of the aromatic vinyl groups, a styryl group is preferred.

[0041] The repeating unit A is preferably a repeating unit represented by formula (a).

[0042]

[0043] In formula (a), R ａ１ , R ａ２ and R ａ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an anionic functional group. ａrepresents a single bond or a (k+1)-valent linking group. A represents an anionic functional group. k represents an integer of 1 to 4. When a plurality of anionic functional groups are present in formula (a), the plurality of anionic functional groups may be the same or different. ａ When is a single bond, k represents 1.

[0044] R ａ１ , R ａ２ and R ａ３ is preferably a hydrogen atom, a halogen atom (fluorine atom, chlorine atom, bromine atom, or iodine atom), a methyl group, an ethyl group, a carboxy group, or a salt thereof, and more preferably a hydrogen atom, a methyl group, or a carboxy group, or a salt thereof. ａ１ , R ａ２ and R ａ３ It is preferred that one of represents a hydrogen atom, a methyl group, a carboxy group, or a salt thereof, and the remaining two each represent a hydrogen atom.

[0045] L ａ The (k+1)-valent linking group represented by the formula (I) is not particularly limited as long as it is a group having a valence corresponding to the number of A, and examples thereof include optionally substituted di- to pentavalent aliphatic hydrocarbon groups, optionally substituted di- to pentavalent aromatic hydrocarbon groups, optionally substituted di- to pentavalent aromatic heterocyclic groups, -O-, -CO-, -SO ２ -, -NR Ｌ -, -N<, and groups formed by combining these. Ｌ represents a hydrogen atom or a monovalent aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched, or cyclic. k is preferably 1, and in this case, L ａ Examples of the divalent linking group represented by the formula (I) include a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, —O—, —CO—, —SO ２ -, -NR Ｌ Among these, a single bond, —CO—O—, —CO—NH—, an alkylene group having 1 to 5 carbon atoms, a phenylene group, and a group formed by combining these are preferred.

[0046] The anionic functional group represented by A is preferably a carboxy group or a salt thereof. k represents an integer of 1 to 4, preferably 1 or 2.

[0047] Examples of the repeating unit A include repeating units derived from a compound selected from the group consisting of acrylic acid, maleic acid, itaconic acid, vinylacetic acid, allylacetic acid, fumaric acid, p-styrenesulfonic acid, vinylsulfonic acid, and 2-acrylamido-2-methyl-1-propanesulfonic acid.

[0048] The content of the repeating unit A is not particularly limited, but is preferably 50 to 100 mol %, more preferably 75 to 100 mol %, and even more preferably 90 to 100 mol %, based on the total repeating units of the specific polymer.

[0049] <Repeating Unit B> The specific polymer may contain a repeating unit B that is different from the repeating unit A. The repeating unit B is not particularly limited, and examples thereof include a repeating unit derived from a compound selected from the group consisting of an aromatic vinyl compound, a (meth)acrylic acid alkyl ester compound that may have a hydroxyl group, an unsaturated alcohol compound, an aliphatic conjugated diene compound, a vinyl cyan compound, and an amide compound having a polymerizable double bond.

[0050] Examples of the aromatic vinyl compound include styrene, α-methylstyrene, vinyltoluene, and p-methylstyrene.

[0051] The content of repeating unit B is not particularly limited, but is preferably 0.1 to 50 mol %, more preferably 1 to 25 mol %, and even more preferably 1 to 15 mol %, based on the total repeating units of the specific polymer.

[0052] The specific polymer is preferably selected from the group consisting of polyacrylic acid, polystyrene sulfonic acid, polyvinyl sulfonic acid, poly(2-acrylamido-2-methyl-1-propanesulfonic acid), 2-acrylamido-2-methyl-1-propanesulfonic acid-acrylic acid copolymer, and styrenesulfonic acid-acrylic acid-vinylphosphonic acid copolymer.

[0053] The weight average molecular weight of the specific polymer is preferably from 500 to 80,000, more preferably from 1,000 to 30,000, even more preferably from 3,000 to 20,000, and particularly preferably from 4,000 to 10,000.

[0054] The specific polymer may be used alone or in combination of two or more. The content of the specific polymer is preferably 0.0001 to 10.0 mass%, more preferably 0.0001 to 1.0 mass%, and even more preferably 0.001 to 1.0 mass%, relative to the total mass of the cleaning solution. The mass ratio of the content of the specific polymer to the total solid content of the cleaning solution is preferably 0.0001 to 10.0, more preferably 0.001 to 1.0, and even more preferably 0.01 to 1.0.

[0055] [Corrosion inhibitor] The cleaning solution of the present invention preferably contains a corrosion inhibitor, as this enhances the effects of the present invention. The corrosion inhibitor has the effect of inhibiting copper corrosion by coordinating to the copper surface. The corrosion inhibitor is not particularly limited, and known corrosion inhibitors can be used, but an azole compound is preferred. The azole compound is a compound containing at least one nitrogen atom and having an aromatic five-membered heterocyclic ring. The number of nitrogen atoms contained in the five-membered heterocyclic ring of the azole compound is not particularly limited, and is preferably 1 to 4, and more preferably 2 to 4.

[0056] The azole compound may have a substituent on the 5-membered heterocyclic ring. Examples of such substituents include a hydroxy group, a carboxy group, a mercapto group, a halogen atom, a nitro group, an alkoxy group, an amino group, and a substituted or unsubstituted hydrocarbon group. Furthermore, when two adjacent substituents are present on the 5-membered heterocyclic ring, the two substituents may be bonded to each other to form a ring. Examples of hydrocarbon groups that may be present on the 5-membered heterocyclic ring include alkyl groups (preferably having 1 to 12 carbon atoms, and more preferably having 1 to 6 carbon atoms), alkenyl groups (preferably having 2 to 12 carbon atoms, and more preferably having 2 to 6 carbon atoms), alkynyl groups (preferably having 2 to 12 carbon atoms, and more preferably having 2 to 6 carbon atoms), aryl groups (preferably having 6 to 18 carbon atoms, and more preferably having 6 to 10 carbon atoms), and aralkyl groups (preferably having 7 to 23 carbon atoms, and even more preferably having 7 to 11 carbon atoms). Examples of substituents present on the hydrocarbon groups include a hydroxy group, a carboxy group, and —N(Ra)(Rb). Ra and Rb each independently represent a hydrogen atom, an alkyl group (preferably having 1 to 6 carbon atoms, more preferably having 1 to 4 carbon atoms), or a hydroxyalkyl group (preferably having 1 to 6 carbon atoms, more preferably having 1 to 4 carbon atoms).

[0057] The ring formed by bonding two adjacent substituents on the hetero 5-membered ring is not particularly limited, but is preferably an aromatic ring (either monocyclic or polycyclic), more preferably a benzene ring.The ring formed by bonding two of the above-mentioned substituents may have a substituent.The substituent is not particularly limited, but may be, for example, the substituents exemplified as the hydrocarbon group of the hetero 5-membered ring.

[0058] 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.

[0059] 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, benzimidazole compounds having a benzimidazole skeleton formed by condensing an imidazole ring with a benzene ring, and purine compounds having a purine skeleton formed by condensing an imidazole ring with a pyrimidine ring. Examples of benzimidazole compounds include benzimidazole, 2-aminobenzimidazole, and 2-mercaptobenzimidazole.

[0060] Examples of pyrazole compounds include pyrazole, 4-pyrazolecarboxylic acid, 1-methylpyrazole, 3-methylpyrazole, 4-methylpyrazole, 3-amino-5-hydroxypyrazole, 3-aminopyrazole, 3-amino-5-tert-butyl-1H-pyrazole, and 4-aminopyrazole.

[0061] Thiazole compounds include, for example, 2,4-dimethylthiazole, benzothiazole, and 2-mercaptobenzothiazole.

[0062] The triazole compound is preferably a compound having a benzotriazole skeleton in which two adjacent substituents on the triazole ring are bonded to each other to form a benzene ring. Examples of the benzotriazole compound include benzotriazole (BTA), 5-aminotetrazole, 1-hydroxybenzotriazole, 5-phenylthiol-benzotriazole, 5-chlorobenzotriazole, 4-chlorobenzotriazole, 5-bromobenzotriazole, 4-bromobenzotriazole, 5-fluorobenzotriazole, 4-fluorobenzotriazole, naphthotriazole, tolyltriazole, 5-phenyl-benzotriazole, 5-nitrobenzotriazole, 4-nitrobenzotriazole, 3-amino-5-mercapto-1,2,4-triazole, 2-(5-amino-pentyl)-benzotriazole, 1-amino-benzotriazole, 5-methyl-1H-benzotriazole (5MBTA), benzotriazole-5-carboxylic acid, 4-methylbenzotriazole, 4-ethylbenzotriazole, 5-ethylbenzotriazole, and 4-propylbenzotriazole. benzotriazole, 5-propylbenzotriazole, 4-isopropylbenzotriazole, 5-isopropylbenzotriazole, 4-n-butylbenzotriazole, 5-n-butylbenzotriazole, 4-isobutylbenzotriazole, 5-isobutylbenzotriazole, 4-pentylbenzotriazole, 5-pentylbenzotriazole, 4-hexylbenzotriazole, 5-hexylbenzotriazole, 5-methoxybenzotriazole, 5-hydroxybenzotriazole, dihydroxypropylbenzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]-benzotriazole, 5-t-butylbenzotriazole, 5-(1',1'-dimethylpropyl)-benzotriazole, 5-(1',1',3'-trimethylbutyl)benzotriazole, 5-n-octylbenzotriazole, and 5-(1',1',3',3'-tetramethylbutyl)benzotriazole.Examples of triazole compounds other than compounds having a benzotriazole skeleton include 1,2,4-triazole, 3-methyl-1,2,4-triazole, 3-amino-1,2,4-triazole, 1,2,3-triazole, and 1-methyl-1,2,3-triazole.

[0063] Examples of tetrazole compounds include 1H-tetrazole (1,2,3,4-tetrazole), 5-methyl-1,2,3,4-tetrazole, 5-amino-1H-tetrazole, 1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole, and 1-(2-dimethylaminoethyl)-5-mercaptotetrazole.

[0064] In addition, the corrosion inhibitor preferably contains at least one of a compound represented by formula (C) and a compound represented by formula (D), and more preferably contains a compound represented by formula (C), in order to obtain a more excellent effect of the present invention. The compound represented by formula (C) and the compound represented by formula (D) are preferred because they are less likely to remain on the copper surface while suppressing copper corrosion.

[0065]

[0066] In formula (C) and formula (D), R ｘ１ ~R ｘ５ 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 hydroxy group, a halogen atom, a sugar group which may have a substituent, or a polyoxyalkylene group-containing group which may have a substituent.

[0067] In formula (C), R ｘ１ and R ｘ２ 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 hydroxy group, a halogen atom, a sugar group which may have a substituent, or a polyoxyalkylene group-containing group which may have a substituent.

[0068] The alkyl group may be linear, branched, or cyclic, and preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms.

[0069] Examples of the sugar group include groups in which one hydroxyl group has been removed from a sugar selected from the group consisting of monosaccharides, disaccharides, and polysaccharides, with groups in which one hydroxyl group has been removed from a monosaccharide being preferred. Examples of monosaccharides include pentoses such as ribose, deoxyribose, arabinose, and xylose, trioses, tetroses, hexoses, and heptoses. Pentose is preferred, with ribose, deoxyribose, arabinose, or xylose being more preferred, and ribose or deoxyribose being even more preferred. Examples of disaccharides include sucrose, lactose, maltose, trehalose, turanose, and cellobiose. Examples of polysaccharides include glycogen, starch, and cellulose. The sugars may be linear or cyclic, with cyclic being preferred. Examples of the cyclic sugars include furanose rings and pyranose rings.

[0070] The polyoxyalkylene group-containing group which may have a substituent refers to a group containing a polyoxyalkylene group which may have a substituent as a part of the group. Examples of the polyoxyalkylene group constituting the polyoxyalkylene group-containing group include a polyoxyethylene group, a polyoxypropylene group, and a polyoxybutylene group, and a polyoxyethylene group is preferred.

[0071] Examples of the substituents that the alkyl group, the amino group, the sugar group, and the polyoxyalkylene group-containing group may have include hydrocarbon groups such as alkyl groups, aryl groups, and benzyl groups that may have a substituent; halogen atoms such as fluorine atoms, chlorine atoms, and bromine atoms; alkoxy groups; hydroxy 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. Note that examples of the substituents that the alkyl groups that may have a substituent may include the groups exemplified above as the substituents, more specifically, aryl groups and heteroaryl groups.

[0072] R ｘ１ R is preferably a hydrogen atom or an amino group which may have a substituent, and more preferably an amino group which may have a substituent. ｘ１ Another preferred embodiment of R is an alkyl group which may have a substituent, a thiol group, a hydroxy group, a halogen atom, a sugar group which may have a substituent, or a group containing a polyoxyalkylene group which may have a substituent. ｘ２ is preferably a hydrogen atom, an alkyl group which may have a substituent, or a sugar group which may have a substituent, more preferably a hydrogen atom or a sugar group which may have a substituent, and even more preferably a hydrogen atom.

[0073] In formula (D), R ｘ３ ~R ｘ５ 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 hydroxy group, a halogen atom, a sugar group which may have a substituent, or a polyoxyalkylene group-containing group which may have a substituent.

[0074] R ｘ３ ~R ｘ５ Examples of the groups represented by the formula (C) include R ｘ１ and R ｘ２ Examples of the group include a group represented by the following formula: ｘ３R is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably an alkyl group which may have a substituent. ｘ３ Another preferred embodiment of R is an alkyl group which may have a substituent, an amino group which may have a substituent, a thiol group, a hydroxy group, a halogen atom, a sugar group which may have a substituent, or a group containing a polyoxyalkylene group which may have a substituent. ｘ４ R is preferably a hydrogen atom or an alkyl group which may have a substituent, and more preferably an alkyl group which may have a substituent. ｘ５ is preferably a hydrogen atom or an alkyl group which may have a substituent.

[0075] Among these, corrosion inhibitors include purine, adenine, xanthine, theobromine, caffeine, adenosine, 6-benzyladenine, kinetin, dimethyladenine, methyladenine, enprofylline, xanthosine, 7-methylxanthosine, 7-methylxanthine, theophylline, eritadenine, paraxanthine, 3-methylxanthine, 1,7-dimethylxanthine, 1-methylxanthine, pyrazole, imidazole, 3-amino-5-tert-butyl-1H-pyrazoline, Preferably, the compound contains at least one selected from the group consisting of adenine, xanthine, adenosine, 6-benzyladenine, kinetin, dimethyladenine, methyladenine, pyrazole, imidazole, 3-amino-5-tert-butyl-1H-pyrazole, 5-amino-1H-tetrazole, and 4-methylpyrazole, and more preferably contains at least one selected from the group consisting of adenine, xanthine, adenosine, 6-benzyladenine, kinetin, dimethyladenine, methyladenine, pyrazole, imidazole, 3-amino-5-tert-butyl-1H-pyrazole, 5-amino-1H-tetrazole, and 4-methylpyrazole.

[0076] The corrosion inhibitor may be used alone or in combination of two or more. The content of the corrosion inhibitor is preferably 0.00001 to 1.0 mass%, more preferably 0.0001 to 0.1 mass%, and even more preferably 0.0001 to 0.01 mass%, relative to the total mass of the cleaning liquid. The mass ratio of the content of the corrosion inhibitor to the total solid content of the cleaning liquid is preferably 0.0001 to 1.0, more preferably 0.001 to 1.0, and even more preferably 0.001 to 0.1.

[0077] [Water] The cleaning solution of the present invention preferably contains water as a solvent, as this enhances the effects of the present invention. The type of water used in the cleaning solution may be any type that does not adversely affect the semiconductor substrate, and distilled water, deionized water (DI: De-Ionized) water, and pure water (ultrapure water) can be used. Pure water (ultrapure water) is preferred because it contains almost no impurities and has less impact on the semiconductor substrate during the semiconductor substrate manufacturing process. The water content is preferably 1.0 mass% or more, more preferably 30.0 mass% or more, even more preferably 60.0 mass% or more, and particularly preferably 80.0 mass% or more, relative to the total mass of the cleaning solution. The upper limit of the water content is preferably 99.999 mass% or less, more preferably 99.99 mass% or less, and even more preferably 98.0 mass% or less, relative to the total mass of the cleaning solution.

[0078] [Low-Molecular-Weight Organic Acid] The cleaning solution of the present invention may contain a low-molecular-weight organic acid. The low-molecular-weight organic acid is a compound that differs from the specific polymer in that it does not have a repeating unit. The molecular weight of the low-molecular-weight organic acid is preferably 600 or less, more preferably 450 or less, and even more preferably 300 or less. The lower limit of the molecular weight is preferably 50 or more, more preferably 100 or more. The number of carbon atoms in the organic acid is preferably 1 to 15, and more preferably 2 to 15.

[0079] The low-molecular-weight organic acid is preferably a carboxylic acid. The carboxylic acid refers to an organic acid having at least one carboxy group in the molecule. Examples of the carboxylic acid include aminopolycarboxylic acid, amino acid, and aliphatic carboxylic acid, with aliphatic carboxylic acid 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), and trans-1,2-diaminocyclohexane. Examples of suitable acetic acids include ethylenediaminetetraacetic acid, ethylenediaminediacetic acid, ethylenediaminedipropionic acid, 1,6-hexamethylene-diamine-N,N,N',N'-tetraacetic acid, N,N-bis(2-hydroxybenzyl)ethylenediamine-N,N-diacetic acid, diaminopropanetetraacetic acid, 1,4,7,10-tetraazacyclododecane-tetraacetic acid, diaminopropanoltetraacetic acid, (hydroxyethyl)ethylenediaminetriacetic acid, and iminodiacetic acid (IDA).

[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, and the compounds described in paragraphs

[0021] to

[0023] of JP 2016-086094 A, as well as salts thereof. Examples of histidine derivatives include the compounds described in JP 2015-165561 A and JP 2015-165562 A, 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 carboxy group and the aliphatic group. Examples of the aliphatic carboxylic acid organic acid include tartaric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, gluconic acid, adipic acid, pimelic acid, sebacic acid, maleic acid, malic acid, and citric acid.

[0083] <Phosphonic Acid Organic Acid> A phosphonic acid organic acid is an organic acid having at least one phosphonic acid group in the molecule. When an organic acid has a phosphonic acid group and a carboxy group, it is classified as a carboxylic acid organic acid. Examples of phosphonic acid organic acids include aliphatic phosphonic acid organic acids and aminophosphonic acid organic acids. The aliphatic phosphonic acid 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), and 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] As the low-molecular-weight organic acid, a carboxylic acid-based organic acid is preferred, an aliphatic carboxylic acid-based organic acid is more preferred, and tartaric acid, malonic acid, succinic acid, malic acid or citric acid is even more preferred.

[0085] The low-molecular-weight organic acid may be used alone or in combination of two or more. The content of the low-molecular-weight organic acid is preferably 0.00001 to 10% by mass, more preferably 0.0003 to 1% by mass, and even more preferably 0.0005 to 0.1% by mass, relative to the total mass of the cleaning solution. The mass ratio of the content of the low-molecular-weight organic acid to the total solids content of the cleaning solution is preferably 0.01 to 90.0% by mass, more preferably 0.1 to 55.0% by mass, and even more preferably 1.0 to 20.0% by mass.

[0086] The mass ratio of the content of the corrosion inhibitor to the content of the low-molecular-weight organic acid is preferably 0.001 to 10.0, more preferably 0.01 to 5.0, and even more preferably 0.1 to 1.0.

[0087] [pH Adjuster] The cleaning solution of the present invention may contain a pH adjuster to adjust and maintain the pH of the cleaning solution of the present invention. The pH adjuster is a basic compound or an acidic compound that is different from the components contained in the cleaning solution of the present invention described above. However, it is acceptable to adjust the pH of the cleaning solution of the present invention by adjusting the amount of each component that can be contained in the cleaning solution of the present invention.

[0088] A basic compound is a compound that exhibits basicity (a pH greater than 7.0) in an aqueous solution, and includes basic inorganic compounds and basic organic compounds. Examples of basic inorganic compounds include ammonia, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and alkaline earth metal hydroxides. Examples of basic organic compounds include quaternary ammonium compounds other than ammonia, and amine compounds such as trishydroxymethylaminomethane.

[0089] <Quaternary ammonium compounds> Among the basic compounds used as pH adjusters, the above-mentioned quaternary ammonium compounds are preferred. The quaternary ammonium compounds may be quaternary ammonium cations (ammonia) that do not have hydrocarbon groups, but are preferably compounds having quaternary ammonium cations in which four hydrocarbon groups (preferably alkyl groups) are substituted on the nitrogen atom. The quaternary ammonium compounds may also be compounds having quaternary ammonium cations in which the nitrogen atom in the pyridine ring is bonded to a substituent (such as 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.

[0090] Examples of quaternary ammonium compounds include ammonia, ammonium fluoride, tris(2-hydroxyethyl)methylammonium hydroxide (THEMAH), 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, and Tris, choline or ETMAH is preferred.

[0091] The acidic compound as a pH adjuster is a compound that exhibits acidity (pH less than 7.0) in an aqueous solution, and examples of the acidic inorganic compound include: hydrochloric acid, nitric acid, nitrous acid, sulfurous acid, phosphoric acid, boric acid, carbonic acid, hypophosphorous acid, phosphorous acid, and hexafluorophosphoric acid; the acidic compound as a pH adjuster may be a salt of the acidic compound, as long as it becomes an acid or an acid ion (anion) in an aqueous solution.

[0092] The content of the pH adjuster can be selected depending on the types and amounts of other components and the target pH of the cleaning solution. For example, the content of the pH adjuster is preferably 0.0001 to 10 mass %, more preferably 0.001 to 8 mass %, and even more preferably 0.01 to 5 mass %, relative to the total mass of the cleaning solution.

[0093] [Other Components] The cleaning solution of the present invention may contain other components in addition to the components described above. These other components include organic solvents, preservatives (antibacterial agents), reducing agents, and dissolved gases. The other components are described below.

[0094] <Organic Solvent> The cleaning solution of the present invention may contain an organic solvent. Examples of the organic solvent include known organic solvents, such as alcohol-based solvents, glycol-based solvents, glycol ether-based solvents, and ketone-based solvents. The organic solvent is preferably miscible with water at any ratio. Examples of the organic solvent include the compounds exemplified in paragraphs

[0135] to

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

[0095] <Preservatives> The cleaning solution of the present invention may contain a preservative. The preservative is a compound different from the components contained in the cleaning solution of the present invention described above. Examples of preservatives include benzoic acid, sodium benzoate, salicylic acid, propionic acid, isopropyl parahydroxybenzoate, isobutyl parahydroxybenzoate, ethyl parahydroxybenzoate, methyl parahydroxybenzoate, butyl parahydroxybenzoate, propyl parahydroxybenzoate, sodium sulfite, sodium hyposulfite, potassium metabisulfite, sorbic acid, potassium sorbate, sodium dehydroacetate, thujaplicin, Aralia udo extract, Styrax japonica extract, Artemisia capillaris extract, oolong tea extract, milt protein extract, enzymatically hydrolyzed Job's tears extract, tea catechins, apple polyphenols, pectin hydrolysates, chitosan, lysozyme, and ε-polylysine. Among these, benzoic acid, sorbic acid, salicylic acid, and propionic acid are preferred as preservatives.

[0096] The content of the preservative is preferably 0.0001 to 10.0% by mass, more preferably 0.0001 to 1.0% by mass, and even more preferably 0.0001 to 0.1% by mass, based on the total mass of the cleaning solution.

[0097] <Reducing Agent> The cleaning solution of the present invention may contain a reducing agent. The reducing agent has a reducing action and reduces OH groups contained in the cleaning solution. － A reducing agent is a compound that has the function of reducing ions or dissolved oxygen, and is also called an oxygen scavenger. The reducing agent improves the corrosion prevention performance of the cleaning solution. The reducing agent used in the cleaning solution is not particularly limited, but examples thereof include ascorbic acid compounds, catechol compounds, hydroxylamine compounds, hydrazide compounds, and reducing sulfur compounds. Specific examples of ascorbic acid compounds, catechol compounds, hydroxylamine compounds, hydrazide compounds, and reducing sulfur compounds include the compounds described in paragraphs

[0084] to

[0093] of WO 2021 / 131452, the contents of which are incorporated herein by reference.

[0098] <Dissolved Gas> The cleaning solution of the present invention may contain a dissolved gas. By setting the concentration of the dissolved gas in the cleaning solution within an appropriate range, it is possible to improve residue removal (cleaning performance). The concentration of the dissolved gas is preferably 0.01 to 10 mg / L relative to the total volume of the cleaning solution of the present invention. In terms of better residue removal, the concentration of the dissolved gas is preferably 0.05 mg / L or more, and more preferably 0.1 mg / L or more, relative to the total volume of the cleaning solution of the present invention. On the other hand, in terms of better storage stability, the concentration is preferably 7 mg / L or less, more preferably 4 mg / L or less, and even more preferably 1.5 mg / L or less, relative to the total volume of the cleaning solution of the present invention.

[0099] The dissolved gas is not particularly limited, but is preferably clean air. In this specification, "clean air" refers to air of Class 8 or lower (Class 8 or lower) in ISO standard ISO 14644-1:2015. The concentration of dissolved gas in the surface treatment composition is determined by the concentration of oxygen gas (O ２ gas), nitrogen gas (N ２ gas), and carbon dioxide gas (CO ２ The concentrations of oxygen gas, nitrogen gas, and carbon dioxide gas can be measured using the processing method described in paragraph

[0020] of WO 2020 / 194978, the contents of which are incorporated herein by reference.

[0100] The concentration of dissolved gas can be controlled by known methods, for example, the methods described in paragraphs

[0019] ,

[0052] to

[0056] , and

[0060] to

[0062] of International Publication No. 2020 / 194978 can be referred to, the contents of which are incorporated herein by reference.

[0101] <Abrasive Particles> The cleaning solution preferably contains substantially no abrasive particles. Abrasive particles refer to particles contained in the polishing solution used in the polishing process of semiconductor substrates, and have an average primary particle diameter of 5 nm or more. Examples of the abrasive particles include inorganic solids such as silica (including colloidal silica and fumed silica), alumina, zirconia, ceria, titania, germania, manganese oxide, and silicon carbide; and organic solids such as polystyrene, polyacrylic resin, and polyvinyl chloride. "Substantially free of abrasive particles" means that the content of abrasive particles is less than 0.1% by mass, preferably 0.01% by mass or less, and more preferably 0.001% by mass or less, based on the total mass of the cleaning solution. The lower limit is not particularly limited, and is 0% by mass. The content of abrasive particles can be measured using a commercially available measuring device that uses a laser light source and employs a light scattering liquid particle measurement method. The average primary particle diameter of particles such as abrasive particles is determined by measuring the particle diameters (circle-equivalent diameters) of 1,000 primary particles randomly selected from an image acquired using a transmission electron microscope TEM2010 (applied voltage 200 kV) manufactured by JEOL Ltd., and then calculating the arithmetic mean of the particle diameters. The circle-equivalent diameter is the diameter of a perfect circle having the same projected area as the projected area of ​​the particle observed. Examples of methods for removing abrasive particles from the cleaning solution include purification processes such as filtering.

[0102] [Physical Properties of Cleaning Solution] <pH> The pH of the cleaning solution is not particularly limited as long as it is 7.5 or higher, but is preferably 9.0 or higher, more preferably 10.0 or higher, and even more preferably 11.0 or higher. The upper limit of the pH is not particularly limited, but an example is 14.0. When the pH is in the above range, the organic residues (aggregates) described above become more easily dissolved in the cleaning solution. The pH of the cleaning solution can be measured using a known pH meter by a method in accordance with JIS Z8802-1984. The pH measurement temperature is 25°C.

[0103] <Metal Content> The content (measured as ion concentration) of metals (e.g., metal elements Fe, Co, Na, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, Sn, and Ag) contained as impurities in the cleaning solution is preferably 5 mass ppm or less, more preferably 1 mass ppm or less. In particular, the content of sodium atoms in the cleaning solution is preferably 1 mass ppm or less relative to the total mass of the cleaning solution. Since it is expected that even higher purity cleaning solutions will be required in the manufacture of cutting-edge semiconductor elements, the content of the above metals is more preferably lower than 1 mass ppm, that is, more preferably on the order of ppb by mass or less, particularly preferably 100 mass ppb or less, and most preferably less than 10 mass ppb. The lower limit is preferably 0.

[0104] Examples of methods for reducing the metal content include 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 production of the cleaning liquid. Another method for reducing the metal content is to use a container that is less likely to leach out impurities, as described below, as a container for containing the raw materials or the produced cleaning liquid. Another method is to provide a fluororesin lining on the inner wall of a pipe or the like to prevent metal components from leaching out from the pipe during the production of the cleaning liquid.

[0105] <Insoluble Particles> The cleaning solution preferably contains substantially no insoluble particles. The term "insoluble particles" refers to particles of inorganic solids, organic solids, and the like that ultimately remain in the cleaning solution without dissolving. The term "substantially free of insoluble particles" refers to a measurement composition obtained by diluting the cleaning solution 10,000 times with the solvent contained in the cleaning solution, and the number of particles with a particle size of 40 nm or more contained in 1 mL of the measurement composition is 40,000 or less. The number of particles contained in the measurement composition can be measured in the liquid phase using a commercially available particle counter. Commercially available particle counters include those manufactured by Rion Corporation and PMS. A representative example of the former is the KS-19F, and a representative example of the latter is the UltraChem 40. To measure larger coarse particles, devices such as the KS-42 series and the LiQuilaz II S series can be used. Examples of insoluble particles include particles of inorganic solids such as silica (including colloidal silica and fumed silica), alumina, zirconia, ceria, titania, germania, manganese oxide, and silicon carbide; and particles of organic solids such as polystyrene, polyacrylic resin, and polyvinyl chloride. Methods for removing insoluble particles from the cleaning solution include, for example, purification treatments such as filtering.

[0106] <Coarse Particles> The cleaning solution may contain coarse particles, but the content thereof is preferably low. Coarse particles refer to particles having a diameter (particle size) of 1 μm or more when the particle shape is considered as a sphere. 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 exist as particles without dissolving in the cleaning solution.

[0107] The content of coarse particles in the cleaning solution is preferably 100 or less, more preferably 50 or less, particles with a particle size of 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 content of coarse particles present in the cleaning solution can be measured in the liquid phase using a commercially available measuring device that uses a laser as a light source for light scattering liquid particle measurement. Methods for removing coarse particles include, for example, purification processes such as filtering, which will be described later.

[0108] [Method for Producing Cleaning Liquid] The cleaning liquid can be produced by a known method, which will be described in detail below.

[0109] [Liquid Preparation Step] The cleaning liquid can be produced, for example, by mixing the above-mentioned components. A method for preparing the cleaning liquid includes, for example, sequentially adding the compound represented by formula (A), the specific polymer, and, if necessary, any optional components to a container containing purified pure water, followed by stirring to mix, and, if necessary, adding a pH adjuster to adjust the pH of the mixed liquid, thereby preparing the cleaning liquid. When adding each component to a container, they may be added all at once, or may be added in portions over several times.

[0110] 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.

[0111] The mixing of the components in the preparation step of the cleaning solution, the purification treatment described below, and 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.

[0112] <Purification> It is preferable to perform a purification treatment in advance on one or more of the raw materials used to prepare the cleaning solution. Examples of purification treatment include known methods such as distillation, ion exchange, and filtration. The degree of purification is preferably such that the raw material has a purity of 99% by mass or more, and more preferably such that the raw material has a purity of 99.9% by mass or more. The upper limit is preferably 99.9999% by mass or less.

[0113] Examples of purification methods include passing the raw material through an ion exchange resin or a reverse osmosis membrane (RO membrane), reprecipitation, distillation of the raw material, and filtering. A combination of the above purification methods may be used as a purification method. For example, the raw material may be subjected to primary purification by passing it through an RO membrane, and then subjected to secondary purification by passing it through a purification device consisting of a cation exchange resin, an anion exchange resin, or a mixed-bed ion exchange resin. Furthermore, the purification process may be performed multiple times.

[0114] The filter used for filtering is not particularly limited as long as it is one that has been conventionally used for filtering purposes. Examples include filters made of fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), polyamide resins such as nylon, polyallylsulfone (PAS), and polyolefin resins (including high-density or ultra-high molecular weight) such as polyethylene and polypropylene (PP). Among these materials, materials selected from the group consisting of polyethylene, polypropylene (including high-density polypropylene), fluororesins (including PTFE and PFA), and polyamide resins (including nylon) are preferred, with fluororesin filters being more preferred. Filtering raw materials using filters made of these materials can effectively remove highly polar contaminants that are likely to cause defects.

[0115] <Container> The cleaning solution (including 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.

[0116] As a container, a container with a high degree of cleanliness within the container for semiconductor applications and that suppresses the elution of impurities from the inner wall of the container's storage section into each liquid is preferred. 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. In addition, the containers exemplified in paragraphs

[0121] to

[0124] of International Publication No. 2022 / 004217 can also be used, and the contents of these containers are incorporated herein.

[0117] 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 containers such as gallon bottles or coated bottles, and then transported and stored.

[0118] 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. A gas with a low water content is particularly preferred. The cleaning solution may be transported and stored at room temperature, or the temperature may be controlled to a range of -20°C to 20°C to prevent deterioration.

[0119] <Clean Room> It is preferable that all of the manufacturing of the cleaning solution, handling including opening and cleaning of containers, filling of the cleaning solution, 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.

[0120] [Dilution Step] The cleaning liquid may be subjected to a dilution step in which a concentrated solution is diluted with a diluent such as water, and then the diluted cleaning liquid (diluted cleaning liquid) may be used to treat an object. That is, the cleaning liquid may be diluted with a diluent containing water before use. Note that the concentrated solution and the diluted cleaning liquid are also forms of the cleaning liquid of the present invention as long as they satisfy the requirements of the present invention.

[0121] It is preferable to perform a purification treatment beforehand on the diluted solution used in the dilution step. It is also more preferable to perform a purification treatment on the diluted cleaning solution obtained by the dilution step. Examples of the purification treatment include a treatment to reduce ion components using an ion exchange resin or an RO membrane, etc., and a treatment to remove foreign matter using filtering, which are described above as purification treatments for the cleaning solution. It is preferable to perform either of these treatments.

[0122] 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 object to be treated, 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 10 to 1,000 times, and even more preferably 10 to 300 times in terms of mass ratio or volume ratio (volume ratio at 23° C.). In addition, the diluted solution preferably contains water, and more preferably is water, in terms of superior residue removal properties.

[0123] 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 preferred embodiments described above.

[0124] 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.

[0125] [Use of cleaning liquid] The cleaning liquid of the present invention is preferably used for cleaning an object that has been subjected to chemical mechanical polishing (CMP). As described above, when using the cleaning liquid, the cleaning liquid may be diluted.

[0126] <Subject> The subject of the cleaning liquid includes, for example, a subject having a metal, such as a semiconductor substrate having a metal. When the semiconductor substrate has a metal, the metal may be present on the front and back surfaces, the side surfaces, or in the grooves of the semiconductor substrate. When the semiconductor substrate has a metal, the metal may be present not only on the surface of the semiconductor substrate but also on the semiconductor substrate via another layer.

[0127] Examples of metals include at least one metal M selected from the group consisting of copper (Cu), cobalt (Co), ruthenium (Ru), aluminum (Al), tungsten (W), titanium (Ti), tantalum (Ta), chromium (Cr), hafnium (Hf), osmium (Os), platinum (Pt), nickel (Ni), manganese (Mn), iron (Fe), zirconium (Zr), molybdenum (Mo), palladium (Pd), lanthanum (La), and iridium (Ir), with Cu, Co, or Ru being preferred, and Cu or Co being more preferred. In other words, the target object is preferably an object containing at least one metal selected from the group consisting of Cu and Co.

[0128] The metal may be any substance containing a metal (metal atom), and examples thereof include a simple substance of metal M and an alloy containing metal M.

[0129] The object to be cleaned by the cleaning liquid may include, for example, a semiconductor substrate, a metal wiring film, a barrier metal, and an insulating film.

[0130] Examples of wafers constituting semiconductor substrates include wafers made of silicon-based materials such as silicon (Si) wafers, silicon carbide (SiC) wafers, silicon-containing resin wafers (glass epoxy wafers), gallium nitride (GaN), gallium phosphide (GaP) wafers, gallium arsenide (GaAs) wafers, and indium phosphide (InP) wafers. Examples of silicon wafers include n-type silicon wafers doped with pentavalent atoms (e.g., phosphorus (P), arsenic (As), and antimony (Sb)), and p-type silicon wafers doped with trivalent atoms (e.g., boron (B) and gallium (Ga)). Examples of silicon in silicon wafers include amorphous silicon, single crystal silicon, 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.

[0131] The insulating film may be, for example, silicon dioxide (SiO ２ ) film, and SiO ２ Examples of low-k films include silicon dioxide films (e.g., silicon dioxide films) and tetraethyl orthosilicate (Si(OC ２ H ５ ) ４ ) film (TEOS film), silicon nitride film (e.g., silicon nitride (Si ３ N ４ ) and silicon carbonitride (SiCN), carbon-doped silicon oxide (SiOC) films, and silicon carbide (SiC) films.

[0132] The metal wiring film is preferably a copper-containing film, a cobalt-containing film, or a ruthenium-containing film. Examples of the copper-containing film include a wiring film (copper wiring film) made only of metallic copper, and a wiring film (copper alloy wiring film) made of an alloy of metallic copper and other metals. Examples of the copper alloy wiring film include a wiring film made of an alloy of copper and one or more metals selected from Al, Ti, Cr, Mn, Ta, and 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).

[0133] Examples of the cobalt-containing film include a metal film made only of metallic cobalt (cobalt metal film) and a metal film made of an alloy of metallic cobalt and other metals (cobalt alloy metal film). Examples of the cobalt alloy metal film include a metal film made of an alloy of cobalt and one or more metals selected from Ti, Cr, Fe, Ni, Mo, Pd, Ta, and W. More specifically, examples of the metal film include a cobalt-titanium alloy metal film (CoTi alloy metal film), a cobalt-chromium alloy metal film (CoCr alloy metal film), a cobalt-iron alloy metal film (CoFe alloy metal film), a cobalt-nickel alloy metal film (CoNi alloy metal film), a cobalt-molybdenum alloy metal film (CoMo alloy metal film), a cobalt-palladium alloy metal film (CoPd alloy metal film), a cobalt-tantalum alloy metal film (CoTa alloy metal film), and a cobalt-tungsten alloy metal film (CoW alloy metal film).

[0134] Examples of ruthenium-containing films include metal films made only of ruthenium metal (ruthenium metal films) and metal films made of alloys made of ruthenium metal and other metals (ruthenium alloy metal films).

[0135] The method of forming the insulating film, copper-containing film, cobalt-containing film, and ruthenium-containing film on the wafer constituting the semiconductor substrate is not particularly limited as long as it is a method that is usually used in this field.As the method of forming the insulating film, for example, the method of forming a silicon oxide film on the wafer constituting the semiconductor substrate by heat treatment in the presence of oxygen gas, and then injecting silane and ammonia gas to form a silicon nitride film by chemical vapor deposition (CVD: Chemical Vapor Deposition) method.As the method of forming the copper-containing film, cobalt-containing film, and ruthenium-containing film, for example, the method of forming a circuit on the wafer having the insulating film by a known method such as resist, and then forming the copper-containing film, cobalt-containing film, and ruthenium-containing film by plating and CVD method, etc.

[0136] The cleaning solution of the present invention can be particularly suitably used for cleaning the copper surface and silicon carbonitride surface of an object having a copper surface and a silicon carbonitride surface that have been subjected to chemical mechanical polishing treatment.

[0137] <CMP Processing> The object is an object that has been subjected to CMP processing (preferably, an object having a metal that has been subjected to CMP processing). CMP processing is a process for planarizing the surface of a semiconductor substrate having, for example, a metal wiring film, a barrier metal, and an insulating film, by a combined action of chemical action and mechanical polishing using a polishing slurry containing abrasive particles (abrasive grains).

[0138] <Subject Subjected to Pad Cleaning Treatment> The surface of the subject may be subjected to a pad cleaning treatment after CMP treatment. Pad cleaning treatment is a treatment that uses a pad to reduce residues present on the surface of the treated area. Specifically, the surface of the subject that has been subjected to CMP treatment is brought into contact with a pad, and the subject and the pad are slid relative to each other while a pad cleaning composition is supplied to the contact area. As a result, residues on the surface of the subject are removed by the frictional force of the pad and the chemical action of the pad cleaning composition.

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

[0140] As the pad cleaning composition, a known cleaning composition can be used depending on the type of object and the type and amount of residue to be removed. Examples of components contained in the pad cleaning composition include ammonium fluoride (NH ４ F), 1-hydroxyethylidene-1,1'-diphosphonic acid (HEDPO), a water-soluble polymer such as polyvinyl alcohol, a dispersion medium such as water, and an acid such as nitric acid. The pad cleaning composition does not contain abrasive particles.

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

[0085] to

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

[0142] In one embodiment of the pad cleaning treatment, a pad cleaning treatment is preferably performed on an object using the cleaning liquid of the present invention as a pad cleaning composition. The cleaning liquid used in the pad cleaning treatment may be a diluted cleaning liquid.

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

[0144] [Method for cleaning an object] The method for cleaning an object of the present invention is not particularly limited as long as it is a treatment method including a step of contacting the object with the cleaning solution of the present invention (contact step). In the present invention, the object is often an object having a copper surface and a silicon carbonitride surface that have been subjected to chemical mechanical polishing. The treatment method can be used to clean, for example, a semiconductor substrate that has been subjected to CMP treatment. The method for cleaning a semiconductor substrate preferably includes a step of applying the diluted cleaning solution obtained in the dilution step to a semiconductor substrate that has been subjected to CMP treatment to clean it.

[0145] The method for contacting the object with the cleaning solution is not particularly limited, and examples include immersing the object in a cleaning solution contained in a tank, spraying the cleaning solution onto the object, pouring the cleaning solution onto the object, and combinations thereof. The above method may be selected appropriately depending on the purpose. Furthermore, the above method may adopt a method typically used in this field. For example, scrubbing, in which a cleaning member such as a brush is physically brought into contact with the surface of the object while supplying the cleaning solution to remove residue, or a spin (drop) method, in which the cleaning solution is dropped onto the rotating object, may be used. In the immersion method, ultrasonic treatment of the object immersed in the cleaning solution is preferred, as this can further reduce impurities remaining on the surface of the object. In terms of achieving better effects of the present invention, the contacting step is preferably any of the following: cleaning using a polishing pad, buff cleaning, immersion cleaning, spin cleaning, and scrubbing cleaning.

[0146] In the contacting step, the object may be contacted with the cleaning solution only once or may be contacted two or more times. When the object is contacted two or more times, the same method may be repeated or different methods may be combined.

[0147] The contacting step may be performed by either a single wafer method or a batch method. The single wafer method generally involves treating objects one by one, while the batch method generally involves treating multiple objects simultaneously.

[0148] The temperature of the cleaning solution is not particularly limited as long as it is a temperature that is normally used in this field. Generally, the cleaning is performed at room temperature (about 25°C), but the temperature can be selected as desired to improve residue removal 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.

[0149] The contact time between the object and the cleaning solution can be changed as appropriate depending on the type and content of the 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.

[0150] The supply amount (supply rate) of the washing liquid in the contact step is preferably 50 to 5,000 mL / min, more preferably 500 to 2,000 mL / min.

[0151] In the contact step, a mechanical stirring method may be used to further enhance the residue removal ability of the cleaning solution. Examples of the mechanical stirring method include a method of circulating the cleaning solution over the semiconductor substrate, a method of flowing or spraying the cleaning solution over the semiconductor substrate, and a method of stirring the cleaning solution using ultrasonic waves or megasonics.

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

[0153] 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 utilized.

[0154] The method of contacting the rinse solution with the object can be the same as the method of contacting the rinse solution with the object. The contact time between the object and the rinse solution can be changed appropriately depending on the type and content of each component contained in the cleaning solution, and the object and purpose for which the cleaning solution is used. In practice, the contact time is preferably 10 to 120 seconds, more preferably 20 to 90 seconds, and even more preferably 30 to 60 seconds.

[0155] The rinsing step may be followed by a drying step for drying the object, such as a spin drying method, a method of passing a dry gas over the semiconductor substrate, a method of heating the substrate with a heating means such as a hot plate or an infrared lamp, a Marangoni drying method, a Rotagoni drying method, an IPA (isopropyl alcohol) drying method, or any combination thereof.

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

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

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

[0159] In the following examples, the pH of the cleaning solution was measured at 25°C using a pH meter (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, filling, storage and analytical measurements of the cleaning solutions were all carried out in a clean room meeting ISO Class 2 or lower.

[0160] [Raw Materials for Cleaning Solutions] The following compounds were used to produce the cleaning solutions of the Examples and Comparative Examples. Note that all of the components used in the Examples were classified as semiconductor grade or equivalent high purity grade.

[0161] [Compounds represented by formula (A)] EEDA: N-ethylethylenediamine Triethylamine MEDA: N-methylethylenediamine N,N-dimethylethylenediamine N,N'-dimethylethylenediamine 1-(2-dimethylaminoethyl)-4-methylpiperazine 1-methylpiperazine 2-aminomethylpiperidine 1-ethylpiperazine N-butylethylenediamine

[0162] [Polymer] Polyethyleneimine Polyacrylic acid Acrylic acid-sulfonic acid copolymer (product name: Aron A-6012 (manufactured by Toagosei Co., Ltd.)) The weight average molecular weight (Mw) of each of the above polymers is shown in the table below.

[0163] [pH adjuster] ETMAH: ethyltrimethylammonium hydroxide Choline THEMAH: tris(2-hydroxyethyl)methylammonium hydroxide

[0164] [Corrosion inhibitors] Adenine 6-benzyladenine Adenosine Xanthine Benzotriazole 5-methylbenzotriazole Pyrazole Imidazole 3-amino-5-tert-butyl-1H-pyrazole 5-amino-1H-tetrazole 4-methylpyrazole

[0165] [Additives] Citric acid, tartaric acid, malonic acid, succinic acid, malic acid

[0166] [Other ingredients] Ultrapure water (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0167] [Production of Cleaning Solution] Next, a production method for each cleaning solution in the Examples and Comparative Examples will be described using Example 1 as an example. N-ethylethylenediamine, polyacrylic acid, ethyltrimethylammonium hydroxide, and adenine were each added to ultrapure water so that the content of each component was the blending ratio shown in each table, and the resulting mixture was then thoroughly stirred to obtain a pre-dilution cleaning solution of Example 1 (a concentrated solution of the cleaning solution of Example 1). The content of ultrapure water in the pre-dilution cleaning solution is the remainder of the composition, obtained by subtracting the content of each component other than ultrapure water used in preparing the composition. The cleaning solution of Example 1 was prepared by diluting the pre-dilution cleaning solution at the dilution ratio (mass ratio) shown in each table. According to the production method for the cleaning solution of Example 1, each cleaning solution in the Examples and Comparative Examples, having the composition shown in the following table, was prepared.

[0168] [Evaluation] Subsequently, the following evaluations were carried out using each of the cleaning solutions of the Examples and Comparative Examples produced by the above-mentioned methods.

[0169] [Evaluation of Cleaning Ability (Organic Residue Removal Ability)] The organic residue removal ability (cleaning ability) when cleaning a semiconductor substrate subjected to chemical mechanical polishing was evaluated. Using a FREX300S-II (polishing apparatus, manufactured by Ebara Corporation), a wafer (12 inches in diameter) having a Cu (copper) film on its surface and a wafer (12 inches in diameter) having a SiCN (silicon carbonitride) film on its surface were polished using polishing solution 1 as the polishing solution under conditions of an in-plane average polishing pressure of 105 hPa, a polishing solution supply rate of 200 mL / min, and a polishing time of 30 seconds. Next, the wafer subjected to the above polishing treatment was further polished using polishing solution 2 as the polishing solution under conditions of an in-plane average polishing pressure of 70 hPa, a polishing solution supply rate of 200 mL / min, and a polishing time of 60 seconds. The resulting CMP-treated wafer was scrubbed for 1 minute using a cleaning solution adjusted to room temperature (23°C) and then dried.

[0170] The compositions of the polishing solutions 1 and 2 are as follows: Polishing Solution 1 (pH 7.0): Colloidal silica (PL3, manufactured by Fuso Chemical Co., Ltd.) 0.1 mass %; Glycine 1.0 mass %; 3-amino-1,2,4-triazole 0.2 mass %; 5-methyl-benzotriazole 90 mass ppm; Hydrogen peroxide 1.0 mass %; pH adjuster (ammonia and nitric acid); Water; Balance Polishing Solution 2 (pH 10.5): Colloidal silica (PL3, manufactured by Fuso Chemical Co., Ltd.) 6.0 mass %; Citric acid 1.0 mass %; Alkyl alkoxylate surfactant 100 mass ppm; 5-methyl-benzotriazole 0.3 mass %; Hydrogen peroxide 1.0 mass %; pH adjuster (potassium hydroxide and nitric acid); Water; Balance

[0171] Next, using a defect detection device (ComPlus-II, manufactured by AMAT Corporation), the number of detected signal intensities corresponding to defects having a length of more than 0.1 μm on the polished surface of the obtained wafer was counted. Thereafter, each defect was observed with a scanning electron microscope (SEM), and if necessary, the constituent elements were identified using an energy dispersive X-ray spectroscopy (EDX). This determined the number of defects based on organic residues (residues mainly composed of organic matter) on the polished surface of the wafer. The cleanability of wafers having a Cu film and wafers having a SiCN film was evaluated based on the following evaluation criteria. A rating of A is most preferable, and in practical terms, a rating of C or higher is preferable.

[0172] (Evaluation Criteria) A: The number of organic residues per wafer is 20 or less. B: The number of organic residues per wafer is more than 20 but not more than 50. C: The number of organic residues per wafer is more than 50 but not more than 80. D: The number of organic residues per wafer is more than 80.

[0173] [Evaluation of Corrosion Inhibition Performance] A 2 x 2 cm copper coupon wafer was prepared, and the corrosion inhibition performance of the cleaning solution against Cu was evaluated. The wafer was immersed in each cleaning solution at room temperature (25°C) for 30 minutes. The Cu content in each cleaning solution after the immersion treatment was then measured using an Agilent 8800 triple quadrupole ICP-MS (for semiconductor analysis, option #200) to determine the etching rate. The obtained etching rates were evaluated based on the following evaluation criteria. A rating of A is most preferable, and a rating of C or higher is practically preferable.

[0174] (Evaluation Criteria) A: Etching rate is less than 0.4 Å / min. B: Etching rate is 0.4 Å / min or more and less than 0.6 Å / min. C: Etching rate is 0.6 Å / min or more and less than 0.8 Å / min. D: Etching rate is 0.8 Å / min or more.

[0175] [Results] The table shows the composition of each cleaning solution used in the examples and comparative examples, as well as the evaluation results of each cleaning solution. In the table, the values ​​in the "Content (mass %)" column indicate the content (mass %) of each component relative to the total mass of the undiluted cleaning solution. The values ​​in the "Dilution ratio (mass ratio)" column indicate the dilution ratio when preparing the cleaning solution by diluting the undiluted cleaning solution. For example, in Example 1, the undiluted cleaning solution was diluted 100 times with pure water to prepare the cleaning solution. The values ​​in the "Post-dilution pH" column indicate the pH of each cleaning solution prepared in the above "Preparation of cleaning solution." The values ​​in the "Series 1" and "Series 2" columns indicate the series of the amine moiety of the compound represented by formula (A). The values ​​in the "ClogP" column indicate the ClogP value of the compound represented by formula (A). The ClogP values ​​were calculated using the software after drawing the structure using ChemDraw Professional (version 20.1.1) manufactured by PerkinElmer. Table 2 is a continuation of Table 1, and Table 3 is a continuation of Table 2. For example, in Example 1, a pre-dilution cleaning solution containing 0.44 mass % of N-ethylethylenediamine, 0.36 mass % of polyacrylic acid, 1.74 mass % of ethyltrimethylammonium hydroxide, and 0.038 mass % of adenine was prepared, and then the cleaning solution was diluted 100 times and evaluated. The results show that the cleaning performance for Cu, the cleaning performance for SiCN, and the corrosion inhibition performance were all rated A.

[0176]

[0177]

[0178]

[0179] From the results in the table, it was confirmed that the cleaning solution of the present invention, when applied to an object having a copper surface and a silicon carbonitride surface that had been subjected to chemical mechanical polishing, had excellent cleaning properties for the copper surface and the silicon carbonitride surface, and caused little corrosion of the copper surface. １ and R ２ is a hydrogen atom, and R ３ and R ４It was confirmed that when at least one of the groups is an alkyl group which may have a substituent other than a carboxy group and a phosphonic acid group, the cleaning ability for copper surfaces is superior. Comparisons between Examples 1 to 11, 15, and 16, etc., confirmed that when the weight-average molecular weight of the polymer is 3000 or more, corrosion of the copper surface is less, and when the weight-average molecular weight of the polymer is 4000 or more, the cleaning ability for silicon carbonitride surfaces is superior and the corrosion of the copper surface is even less. Comparisons between Examples 1 to 11, 17, and 18, etc., confirmed that when the pH of the semiconductor substrate cleaning liquid is 10.0 or more, the cleaning ability for copper surfaces is superior, and when the pH is 11.0 or more, the cleaning ability for copper surfaces is even superior. Comparisons between Examples 1 to 11 and Example 19, etc., confirmed that when the semiconductor substrate cleaning liquid further contains a corrosion inhibitor, corrosion of the copper surface is less. Comparison of Examples 1 to 11 with Examples 20 and 21, etc., confirmed that when the corrosion inhibitor contains at least one of the compound represented by formula (C) and the compound represented by formula (D), the cleaning ability for copper surfaces is superior and the corrosion of the copper surface is reduced. Comparison of Examples 1 to 11 with Examples 22 to 24, etc., confirmed that when at least one of the ClogP value of the compound represented by formula (A) is a negative value and the number of carbon atoms of the compound represented by formula (A) is 5 or less, the cleaning ability for copper surfaces is superior.

Claims

1. A cleaning solution for semiconductor substrates, comprising a compound represented by formula (A) and a polymer having a group selected from the group consisting of a carboxy group and a salt thereof, and a sulfonic acid group and a salt thereof, and having a pH of 7.5 or more. In formula (A), R １ ~R ８ each independently represents an alkyl group which may have a substituent other than a carboxy group or a phosphonic acid group, or a hydrogen atom. １ ~R ４ At least one of R represents an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, and an amino group. ３ and R ７ may be bonded via a single bond or a divalent linking group to form a ring, R １ and R ３ may be linked via a single bond or a divalent linking group to form a ring.

2. R ５ and R ６ The cleaning liquid for a semiconductor substrate according to claim 1, wherein both are hydrogen atoms.

3. R １ to R ８ each independently represents an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group and a hydroxy group, or a hydrogen atom, and at least one of R １ to R ４ represents an alkyl group which may have a substituent other than a carboxy group, a phosphonic acid group, a hydroxy group and an amino group. The cleaning liquid for a semiconductor substrate according to claim 1.

4. R １ and R ２ are hydrogen atoms, and at least one of R ３ and R ４ is an alkyl group which may have a substituent other than a carboxy group and a phosphonic acid group, the cleaning liquid for a semiconductor substrate according to claim 1.

5. The cleaning liquid for a semiconductor substrate according to claim 1, wherein the weight average molecular weight of the polymer is 4000 or more.

6. The cleaning liquid for a semiconductor substrate according to claim 1, wherein the pH is 10.0 or more.

7. The cleaning liquid for a semiconductor substrate according to claim 1, wherein the pH is 11.0 or more.

8. The cleaning liquid for a semiconductor substrate according to claim 1, further comprising a corrosion inhibitor.

9. The cleaning liquid for a semiconductor substrate according to claim 8, wherein the corrosion inhibitor contains at least one of a compound represented by formula (C) and a compound represented by formula (D). In formula (C) and formula (D), R ｘ１ to R ｘ５ 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 hydroxy group, a halogen atom, a sugar group which may have a substituent, or a polyoxyalkylene group-containing group which may have a substituent.

10. The cleaning liquid for a semiconductor substrate according to claim 1, wherein the ClogP value of the compound represented by the formula (A) is a negative value.

11. The cleaning liquid for a semiconductor substrate according to claim 1, wherein the number of carbon atoms of the compound represented by the formula (A) is 5 or less.

12. The cleaning liquid for a semiconductor substrate according to claim 1, containing water.

13. The cleaning liquid for a semiconductor substrate according to claim 1, which is used for cleaning an object subjected to chemical mechanical polishing treatment.

14. The cleaning liquid for a semiconductor substrate according to claim 13, wherein the object has a copper surface and a silicon carbonitride surface subjected to chemical mechanical polishing treatment, and is used for cleaning the copper surface and the silicon carbonitride surface.

15. A method for cleaning an object, comprising a step of bringing an object having a copper surface and a silicon carbonitride surface subjected to chemical mechanical polishing treatment into contact with the cleaning liquid for a semiconductor substrate according to any one of claims 1 to 14.

16. The method for cleaning an object according to claim 15, wherein the step is any one of cleaning using a polishing pad, buffing cleaning, cleaning by an immersion method, spin cleaning, and scrub cleaning.

17. A method for manufacturing a semiconductor device, having the method for cleaning an object according to claim 15.

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