Cleaning composition, method for cleaning semiconductor substrates, method for manufacturing semiconductor devices
A cleaning composition with polycarboxylic acid, chelating agent, and sulfonic acid improves storage stability, ensuring consistent cleaning and corrosion prevention for semiconductor substrates.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-06-10
- Publication Date
- 2026-04-13
AI Technical Summary
Existing cleaning compositions for semiconductor substrates after chemical mechanical polishing (CMP) exhibit poor storage stability, leading to deteriorated cleaning and corrosion prevention performance over time.
A cleaning composition comprising polycarboxylic acid, a chelating agent, a sulfonic acid with an alkyl group of 9 to 18 carbon atoms, and water, with specific mass ratios and pH levels to enhance storage stability.
The composition provides excellent storage stability, maintaining effective cleaning and corrosion prevention performance over time.
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Abstract
Description
[Technical Field]
[0001] This invention relates to a cleaning composition, a method for cleaning a semiconductor substrate, and a method for manufacturing a semiconductor device. [Background technology]
[0002] Cleaning compositions are used in various fields for purposes such as removing foreign matter. For example, in the semiconductor field, they are used in the following applications: Semiconductor devices such as CCDs (Charge-Coupled Devices) and memory are manufactured by forming fine electronic circuit patterns on a substrate using photolithography technology. Specifically, a resist film is formed on a laminate on a substrate that has a metal film that serves as the wiring material, an etching stop layer, and an interlayer insulating layer, and then the semiconductor device is manufactured by performing a photolithography process and a dry etching process (e.g., plasma etching).
[0003] In the manufacturing of semiconductor devices, chemical mechanical polishing (CMP) is sometimes performed to planarize the surface of a semiconductor substrate having metal wiring films, barrier metals, and insulating films using a polishing slurry containing abrasive particles (e.g., silica and alumina). In CMP, metal components derived from the abrasive particles used in the CMP process, the polished wiring metal films, and / or barrier metals tend to remain on the surface of the semiconductor substrate after polishing. Since these residues can short-circuit the wiring and affect the electrical properties of the semiconductor, a cleaning process to remove these residues from the surface of the semiconductor substrate is generally performed.
[0004] As an example of a cleaning composition used in the cleaning process, Patent Document 1 discloses "a cleaning composition for use after chemical mechanical polishing, characterized by containing organic polymer particles (A) having a cross-linked structure and a surfactant (B)." [Prior art documents] [Patent Documents]
[0005] [Patent Document 1] Japanese Patent Publication No. 2005-255983 [Overview of the project] [Problems that the invention aims to solve]
[0006] The present inventors investigated the cleaning compositions described in Patent Document 1, etc., and found that they have poor storage stability. For example, the present inventors stored the cleaning composition described in Patent Document 1 for a certain period of time, and then used the obtained cleaning composition to investigate its cleaning performance and corrosion prevention performance on a semiconductor substrate containing a metal film that had undergone CMP treatment. As a result, they found that the longer the storage time, the worse at least one of the cleaning performance and corrosion prevention performance of the cleaning composition became. In the following, "excellent storage stability" means that the cleaning composition exhibits excellent cleaning and corrosion-preventive properties after being stored for a certain period of time.
[0007] The object of this invention is to provide a cleaning composition with excellent storage stability. Furthermore, the present invention also aims to provide a method for cleaning semiconductor substrates and a method for manufacturing semiconductor devices. [Means for solving the problem]
[0008] The inventors have found that the above problems can be solved by the following configuration.
[0009] [1] It contains a polycarboxylic acid, a chelating agent, a sulfonic acid having an alkyl group with 9 to 18 carbon atoms, and water. The mass ratio of the polycarboxylic acid to the chelating agent is 10 to 200. The mass ratio of the polycarboxylic acid to the sulfonic acid is 70 to 1000. The pH is between 0.10 and 4.00. A cleaning composition having an electrical conductivity of 0.08 to 11.00 mS / cm. [2] The cleaning composition according to [1], wherein the polycarboxylic acid contains a polycarboxylic acid having 2 to 3 carboxy groups. [3] The cleaning composition according to [1] or [2], wherein the polycarboxylic acid further contains a polycarboxylic acid having a hydroxy group. [4] The cleaning composition according to any one of [1] to [3], wherein the polycarboxylic acid contains citric acid. [5] The cleaning composition according to any one of [1] to [4], wherein the content of the polycarboxylic acid is 0.1 to 35% by mass based on the total mass of the cleaning composition. [6] The cleaning composition according to any one of [1] to [5], wherein the sulfonic acid is an alkylbenzene sulfonic acid. [7] The cleaning composition according to any one of [1] to [6], wherein the sulfonic acid has an alkyl group having 10 to 13 carbon atoms. [8] The cleaning composition according to any one of [1] to [7], wherein the sulfonic acid contains alkylbenzene sulfonic acid A having an alkyl group having 10 carbon atoms, alkylbenzene sulfonic acid B having an alkyl group having 11 carbon atoms, alkylbenzene sulfonic acid C having an alkyl group having 12 carbon atoms, and alkylbenzene sulfonic acid D having an alkyl group having 13 carbon atoms. [9] The cleaning composition according to [8], wherein the content of the alkylbenzene sulfonic acid B is 20 to 50% by mass based on the total mass of the alkylbenzene sulfonic acids A to D.
[10] The cleaning composition according to any one of [1] to [9], wherein the chelating agent has a phosphonic acid group.
[11] The cleaning composition according to any one of [1] to
[10] , wherein the mass ratio of the polycarboxylic acid to the chelating agent is 30 to 100.
[12] The cleaning composition according to any one of [1] to
[11] , wherein the mass ratio of the polycarboxylic acid to the sulfonic acid is 70 to 600.
[13] Furthermore, it contains phosphate ions, The cleaning composition according to any one of [1] to
[12] , wherein the content of the above-mentioned phosphate ions is 0.001 to 1.0% by mass with respect to the total mass of the cleaning composition.
[14] A method for cleaning a semiconductor substrate, comprising cleaning the semiconductor substrate using a cleaning composition described in any one of [1] to
[13] .
[15] A method for manufacturing a semiconductor device, comprising the method for cleaning a semiconductor substrate described in
[14] . [Effects of the Invention]
[0010] According to the present invention, a cleaning composition with excellent storage stability can be provided. Furthermore, according to the present invention, a method for cleaning a semiconductor substrate and a method for manufacturing a semiconductor device can also be provided. [Modes for carrying out the invention]
[0011] An example of an embodiment for carrying out the present invention is described below. The meanings of each term used in this specification are as follows. A numerical range represented using "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively.
[0012] "ppm" stands for "parts-per-million (10 -6 ) means "ppb" stands for "parts-per-billion (10 -9 It means ")". "psi" stands for pound-force per square inch, and 1 psi = 6894.76 Pa.
[0013] When two or more components are present, the "content" of those components refers to the total content of those two or more components. Unless otherwise specified, the compounds described herein may include structural isomers, optical isomers, and isotopes. Furthermore, structural isomers, optical isomers, and isotopes may be present individually or in combination of two or more. Unless otherwise specified, the bonding direction of the divalent group (e.g., -COO-) is not restricted. For example, in a compound represented by the formula "XYZ", if Y is -COO-, the compound may be "XO-CO-Z" or "X-CO-OZ".
[0014] "Weight-average molecular weight" refers to the weight-average molecular weight in terms of polyethylene glycol, measured by GPC (gel permeation chromatography).
[0015] "On the semiconductor substrate" includes, for example, the front and back surfaces, sides, and inside grooves of the semiconductor substrate. Furthermore, "metal-containing material on the semiconductor substrate" includes not only cases where the metal-containing material is directly on the surface of the semiconductor substrate, but also cases where the metal-containing material is present on the semiconductor substrate via other layers.
[0016] [Cleaning composition] The cleaning composition of the present invention comprises a polycarboxylic acid, a chelating agent, a sulfonic acid having an alkyl group with 9 to 18 carbon atoms, and water. The mass ratio of polycarboxylic acid to chelating agent is 10 to 200. The mass ratio of polycarboxylic acid to sulfonic acid is 70 to 1000. The pH is between 0.10 and 4.00. The electrical conductivity is 0.08 to 11.00 mS / cm.
[0017] The mechanism by which the above configuration solves the problems of the present invention is not entirely clear, but the inventors speculate as follows. It is presumed that if the cleaning composition of the present invention satisfies the specified requirements, the compounds will interact with each other, resulting in excellent storage stability. Hereinafter, the superior storage stability will also be referred to as "the superior effects of the present invention." The components contained in the cleaning composition will be described below.
[0018] 〔Polycarboxylic acid〕 The cleaning composition contains a polycarboxylic acid. A polycarboxylic acid is a compound having two or more carboxy groups in the molecule. It is a compound different from the chelating agent described later. The polycarboxylic acid preferably does not have an amino group as a functional group. The polycarboxylic acid may have other functional groups other than the carboxy group. As the other functional group, a hydroxy group is preferable. The number of carboxy groups possessed by the polycarboxylic acid is preferably 2 to 10, more preferably 2 to 3. The number of hydroxy groups possessed by the polycarboxylic acid is preferably 1 to 3, more preferably 1. The polycarboxylic acid preferably contains a polycarboxylic acid having 2 to 3 carboxy groups. It is also preferable to contain a polycarboxylic acid having a hydroxy group in addition to the carboxy group, and it is more preferable to contain a polycarboxylic acid having 2 to 3 carboxy groups and a hydroxy group. The polycarboxylic acid may be in the form of a salt.
[0019] As the polycarboxylic acid, a compound represented by formula (D1) is preferable.
[0020]
Chemical formula
[0021] In formula (D1), L d represents -CR d1 R d2 - or an alkenyl group which may have a substituent. R d1 and R d2 each independently represent a hydrogen atom, a hydroxy group or a carboxy group. n represents an integer of 0 to 5.
[0022] L d represents -CR d1 Rd2 - Represents an alkenyl group which may have a substituent. d1 and R d2 Each of these independently represents a hydrogen atom, a hydroxyl group, or a carboxyl group. The number of carbon atoms in the above alkenyl group is preferably 2 to 10, and more preferably 2 to 5. The above alkenyl group may be linear, branched, or cyclic, with linear being preferred. Examples of substituents on the above-mentioned alkenyl group include halogen atoms such as fluorine, chlorine, and bromine atoms, hydroxyl groups, and carboxyl groups. Unsubstituted alkenyl groups are also preferred. A vinylene group is preferred as the above-mentioned alkenyl group. R d1 and R d2 The total number of hydroxyl groups represented is preferably 0 to 4, more preferably 1 to 2, and even more preferably 1. R d1 and R d2 The total number of carboxyl groups represented is preferably 0 to 4, more preferably 1 to 2, and even more preferably 1. R d1 and R d2 The hydroxyl group and R represented by d1 and R d2 The total number of carboxyl groups represented is preferably 0 to 8, more preferably 2 to 4, and even more preferably 2. Multiple Rs exist d1 Multiple Rs exist. d2 L that are the same as each other and multiple Ls that exist d The same or different items may be.
[0023] n represents an integer between 0 and 5. n is preferably an integer between 0 and 4, more preferably an integer between 0 and 3, and even more preferably an integer between 1 and 3.
[0024] Examples of polycarboxylic acids include aliphatic polycarboxylic acids. Examples of aliphatic polycarboxylic acids include citric acid, oxalic acid, tartaric acid, malic acid, maleic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, and sebacic acid. At least one selected from the group consisting of citric acid, oxalic acid, tartaric acid, malic acid, and maleic acid is preferred, with citric acid being more preferred. Furthermore, it is preferable that the polycarboxylic acid consists solely of citric acid.
[0025] The molecular weight of the polycarboxylic acid is preferably 70 to 400, more preferably 80 to 300, and even more preferably 120 to 200.
[0026] Polycarboxylic acids may be used individually or in combination of two or more types. The polycarboxylic acid content is often 0.001 to 35% by mass, preferably 0.1 to 35% by mass, more preferably 1.0 to 35% by mass, even more preferably 3.0 to 35% by mass, even more preferably 10.0 to 35% by mass, and particularly preferably 20.0 to 35% by mass, based on the total mass of the cleaning composition. In particular, in the preferred embodiment of the polycarboxylic acid content described above, the polycarboxylic acid preferably contains at least one selected from the group consisting of citric acid and malic acid, and more preferably consists of only at least one selected from the group consisting of citric acid and malic acid. In another preferred embodiment, when the polycarboxylic acid contains tartaric acid (preferably consisting solely of tartaric acid), the polycarboxylic acid content is preferably 0.01 to 30% by mass, more preferably 0.5 to 30% by mass, even more preferably 1.0 to 10% by mass, and particularly preferably 3.0 to 10% by mass. In another preferred embodiment, when the polycarboxylic acid contains oxalic acid (preferably consisting solely of oxalic acid), the polycarboxylic acid content is preferably 0.01 to 20% by mass, and more preferably 0.1 to 10% by mass. In another preferred embodiment, the polycarboxylic acid contains at least one selected from the group consisting of maleic acid (preferably consisting only of maleic acid), in which case the polycarboxylic acid content is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.5 to 10% by mass.
[0027] [Chelating agent] The cleaning composition contains a chelating agent. The chelating agent is a compound different from the polycarboxylic acid described above. Furthermore, it is preferable that it is a compound different from the specific sulfonic acid, surfactant, and other components described later. Examples of chelating agents include organic acids, such as carboxylic acid-based organic acids and phosphonic acid-based organic acids, with phosphonic acid-based organic acids being preferred. The chelating agent may also be in the form of a salt.
[0028] Examples of acidic groups found in organic acids (chelating agents) include carboxyl groups, phosphonic acid groups, sulfo groups, and phenolic hydroxyl groups. The organic acid (chelating agent) preferably has at least one selected from the group consisting of a carboxyl group and a phosphonic acid group, and more preferably has a phosphonic acid group. The number of acid groups in the organic acid (chelating agent) is preferably 1 to 5, and more preferably 2 to 4.
[0029] <Carboxylic acid-based organic acids> Carboxylic acid-based organic acids are organic acids that have at least one carboxyl group in their molecule. Preferred carboxylic acid-based organic acids are compounds that have only one carboxyl group in their molecule, or compounds that have both a carboxyl group and an amino group in their molecule. Examples of carboxylic acid-based organic acids include aminopolycarboxylic acid-based organic acids and amino acid-based organic acids.
[0030] Examples of aminopolycarboxylic acid-based organic acids include butylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid (DTPA), ethylenediaminetetrapropionic acid, triethylenetetraminehexaacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid, propylenediaminetetraacetic acid, ethylenediaminetetraacetic acid (EDTA), trans-1,2-diaminocyclohexanetetraacetic 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), with ethylenediaminetetraacetic acid (EDTA) being preferred.
[0031] Examples of amino acid-based organic acids include glycine, serine, α-alanine and its salts, β-alanine and its salts, lysine, leucine, isoleucine, cystine, cysteine, ethionine, threonine, tryptophan, tyrosine, valine, histidine and histidine derivatives, asparagine, aspartic acid and its salts, glutamine, glutamic acid and its salts, arginine, proline, methionine, phenylalanine, and the compounds and their salts described in paragraphs
[0021] to
[0023] of Japanese Patent Application Publication No. 2016-086094. Examples of histidine derivatives include the compounds described in Japanese Patent Publication No. 2015-165561 and Japanese Patent Publication No. 2015-165562, the details 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 acetate salts.
[0032] <Phosphonic acid-based organic acids> Phosphonic acid-based organic acids are organic acids that have at least one phosphonic acid group in their molecule. Furthermore, if the chelating agent has both a phosphonic acid group and a carboxyl group, it is classified as a carboxylic acid-based organic acid. Examples of phosphonic acid-based organic acids include aliphatic phosphonic acid-based organic acids and aminophosphonic acid-based organic acids. Aliphatic phosphonic acid organic acids may also have a hydroxyl group in addition to the phosphonic acid group and the aliphatic group.
[0033] The number of phosphonic acid groups in a phosphonic acid-based organic acid is preferably 2 to 5, more preferably 2 to 4, and even more preferably 2 to 3. The number of carbon atoms in the phosphonic acid-based organic acid is preferably 1 to 12, more preferably 1 to 10, and even more preferably 1 to 3.
[0034] Examples of phosphonic acid-based organic acids include 1-hydroxyethylidene-1,1'-diphosphonic acid (HEDPO), ethylidene diphosphonic acid, 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), ethylenediaminetetramethylenephosphonic acid (EDTMP), 1,3-propylenediaminebis(methylenephosphonic acid), and ethylenediaminetetra(methylenephosphonic acid). Examples include HEDPO (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), triethylenetetraminehexa(ethylenephosphonic acid) and their salts, with HEDPO or EDTMP being preferred, and HEDPO being more preferred. Examples of salts include alkali metal salts such as sodium salts and potassium salts, ammonium salts, carbonates, and acetate salts.
[0035] Examples of phosphonic acid-based organic acids are found in paragraph
[0026] of International Publication No. 2018 / 020878.
[0036] Examples include the compounds described in [reference] and the compounds ((co)polymers) described in paragraphs
[0031] to
[0046] of International Publication No. 2018 / 030006, the contents of which are incorporated herein by reference.
[0036] Some commercially available phosphonic acid-based organic acids contain both the phosphonic acid-based organic acid and water such as distilled water, deionized water, and ultrapure water. Commercially available phosphonic acid-based organic acids containing the above-mentioned water may also be used.
[0037] The molecular weight of the chelating agent is preferably 600 or less, more preferably 450 or less, and even more preferably 300 or less. The lower limit is often 80 or more, and preferably 100 or more.
[0038] Chelating agents may be used individually or in combination of two or more types. The chelating agent content is often 0.001% by mass or more, preferably 0.20% by mass or more, more preferably 0.25% by mass or more, even more preferably 0.35% by mass or more, particularly preferably 0.45% by mass or more, and most preferably 0.50% by mass or more, relative to the total mass of the cleaning composition, in order to achieve a well-balanced and excellent performance of the cleaning composition. The upper limit is often 5.00% by mass or less, preferably 1.40% by mass or less, more preferably 1.10% by mass or less, even more preferably 0.90% by mass or less, particularly preferably 0.70% by mass or less, and most preferably 0.60% by mass or less, relative to the total mass of the cleaning composition.
[0039] [Specific sulfonic acids] The cleaning composition contains a specific sulfonic acid. A specific sulfonic acid is a sulfonic acid having an alkyl group with 9 to 18 carbon atoms. The specific sulfonic acid may also be in the form of a salt. The specific sulfonic acid is a compound different from the compounds mentioned above.
[0040] The number of sulfonic acid groups in a particular sulfonic acid is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. The alkyl group of the specific sulfonic acid may be linear, branched, or cyclic, with linear or branched being preferred, and branched being more preferred. The number of carbon atoms in the alkyl group described above is 9 to 18, preferably 10 to 15, and more preferably 10 to 13. The specific sulfonic acid may also have other alkyl groups (for example, alkyl groups with 1 to 8 carbon atoms) as long as it has an alkyl group with 9 to 18 carbon atoms.
[0041] The specified sulfonic acid may have other groups besides the sulfonic acid group and the alkyl group mentioned above. Among the other groups mentioned above, aromatic ring groups are preferred. Aromatic ring groups may be monocyclic or polycyclic. The number of aromatic ring groups in the specific sulfonic acid is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. The number of carbon atoms in the aromatic ring group is preferably 6 to 20, and more preferably 6 to 15. Examples of rings constituting the aromatic ring group include aromatic hydrocarbon rings such as benzene rings and naphthalene rings, with benzene rings or naphthalene rings being preferred, and benzene rings being more preferred.
[0042] The specific sulfonic acid preferably has one of the C10 to C13 alkyl groups. Note that having one of the C10 to C13 alkyl groups means having one of the C10 alkyl group, C11 alkyl group, C12 alkyl group, and C13 alkyl group; for example, it does not include embodiments having both a C10 alkyl group and a C11 alkyl group. Furthermore, the specific sulfonic acid preferably includes alkylbenzenesulfonic acid A having a C10 alkyl group, alkylbenzenesulfonic acid B having an C11 alkyl group, alkylbenzenesulfonic acid C having a C12 alkyl group, and alkylbenzenesulfonic acid D having a C13 alkyl group. In other words, the specific sulfonic acid preferably contains four or more alkylbenzenesulfonic acids.
[0043] As the specific sulfonic acid, the compound represented by formula (A1) is preferred.
[0044] R a -Ar a -SO3H (A1)
[0045] In formula (A1), R a Ar represents an alkyl group with 9 to 18 carbon atoms. a This represents an arylene group.
[0046] R a This represents an alkyl group with 9 to 18 carbon atoms. The alkyl group mentioned above is synonymous with the alkyl group having 9 to 18 carbon atoms that the specified sulfonic acid possesses, and the preferred embodiment is the same.
[0047] Ar a This represents an arylene group. The above-mentioned arylene group may be monocyclic or polycyclic. The number of carbon atoms in the arylene group is preferably 6 to 20, and more preferably 6 to 15. As the arylene group, a phenylene group or a naphthylene group is preferred.
[0048] Examples of specific sulfonic acids include alkylbenzenesulfonic acids such as 4-(1-methyloctyl)benzenesulfonic acid, 4-(1-methylnonyl)benzenesulfonic acid, 4-(1-methyldecyl)benzenesulfonic acid, 4-(1-methylundecyl)benzenesulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, tridecylbenzenesulfonic acid, and tetradecylbenzenesulfonic acid, as well as their salts; decylsulfonic acid, etc. Examples include alkyl sulfonic acids such as dodecyl sulfonic acid, dodecyl sulfonic acid, tridecyl sulfonic acid, and tetradecyl sulfonic acid, and their salts; and alkyl naphthalene sulfonic acids such as 5-undecyl-2-naphthalene sulfonic acid, 5-dodecyl-2-naphthalene sulfonic acid, decyl naphthalene sulfonic acid, undecyl naphthalene sulfonic acid, dodecyl naphthalene sulfonic acid, tridecyl naphthalene sulfonic acid, and tetradecyl naphthalene sulfonic acid, and their salts. Alkylbenzenesulfonic acid is preferred as the specific sulfonic acid. Examples of the salts mentioned above include alkali metal salts such as sodium salts and potassium salts, as well as ammonium salts.
[0049] The molecular weight of the specific sulfonic acid is preferably 100 to 1000, and more preferably 200 to 500.
[0050] Specific sulfonic acids may be used individually or in combination of two or more. The content of specific sulfonic acid is often 0.0001% by mass or more, preferably 0.03% by mass or more, more preferably 0.04% by mass or more, even more preferably 0.05% by mass or more, particularly preferably 0.06% by mass or more, and most preferably 0.07% by mass or more, based on the total mass of the cleaning composition. The upper limit is often 1.00% by mass or less, preferably 0.40% by mass or less, more preferably 0.10% by mass or less, and even more preferably 0.08% by mass or less, based on the total mass of the cleaning composition. The content of alkylbenzenesulfonic acid A is preferably 0 to 100% by mass, more preferably 1 to 30% by mass, even more preferably 3 to 20% by mass, and particularly preferably 7 to 15% by mass, relative to the total mass of alkylbenzenesulfonic acids A to D. The content of alkylbenzenesulfonic acid B is preferably 0 to 100% by mass, more preferably 20 to 50% by mass, and even more preferably 30 to 40% by mass, relative to the total mass of alkylbenzenesulfonic acids A to D. The content of alkylbenzenesulfonic acid C is preferably 0 to 100% by mass, more preferably 10 to 60% by mass, even more preferably 20 to 40% by mass, and particularly preferably 25 to 35% by mass, relative to the total mass of alkylbenzenesulfonic acids A to D. The content of alkylbenzenesulfonic acid D is preferably 0 to 100% by mass, more preferably 10 to 50% by mass, even more preferably 15 to 40% by mass, and particularly preferably 20 to 30% by mass, relative to the total mass of alkylbenzenesulfonic acids A to D.
[0051] 〔water〕 The cleaning composition contains water. The water mentioned above is not particularly limited. Examples include distilled water, deionized water, and pure water (ultrapure water). 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 not particularly limited, as long as it is the remainder of the components that may be included in the cleaning composition. The water content is preferably 1.0% by mass or more, more preferably 30.0% by mass or more, even more preferably 50.0% by mass or more, and particularly preferably 60.0% by mass or more, based on the total mass of the cleaning composition. The upper limit is preferably 99.99% by mass or less, more preferably 99.9% by mass or less, even more preferably 99.0% by mass or less, and particularly preferably 97.0% by mass or less, based on the total mass of the cleaning composition.
[0052] [Mass ratio of components] The mass ratio of polycarboxylic acid to chelating agent (mass of polycarboxylic acid / mass of chelating agent) is 10 to 200, preferably 30 to 100, more preferably 40 to 80, and even more preferably 50 to 60, from the viewpoint of achieving superior effects of the present invention. The mass ratio of polycarboxylic acid to specific sulfonic acid (mass of polycarboxylic acid / mass of specific sulfonic acid) is 70 to 1000, preferably 70 to 800, more preferably 70 to 600, and particularly preferably 410 to 440. The mass ratio of the chelating agent content to the specific sulfonic acid content (chelating agent content / specific sulfonic acid content) is preferably 1 to 20.
[0053] [Physical properties of the cleaning composition] <ph> The pH of the cleaning composition is 0.10 to 4.00, preferably 0.10 to 3.00, and more preferably 0.10 to 1.50. The pH of the cleaning composition can be measured using a known pH meter in accordance with the method specified in JIS Z8802-1984. The pH measurement temperature should be 25°C. Methods for adjusting pH include, for example, adjusting the types and amounts of each component that may be included in the cleaning composition, and adding a pH adjusting agent, as described later.
[0054] <Electrical conductivity> The electrical conductivity of the cleaning composition is 0.08 to 11.00 mS / cm, preferably 1.00 to 11.00 mS / cm, more preferably 5.00 to 11.00 mS / cm, and even more preferably 8.00 to 10.00 mS / cm. One method for measuring electrical conductivity is to use an electrical conductivity meter (electrical conductivity meter: portable type D-70 / ES-70 series, manufactured by Horiba, Ltd.). The measurement temperature for electrical conductivity is set at 25°C. One method for adjusting the electrical conductivity mentioned above is to adjust the types and amounts of each component that may be contained in the cleaning solution.
[0055] <Content of metallic impurities> The content (measured as ion concentration) of metal impurities (metal elements Fe, Co, Na, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, Sn, and Ag) is preferably 5 ppm by mass or less, and more preferably 1 ppm by mass or less, relative to the total mass of the cleaning composition. From the standpoint of application to the manufacture of state-of-the-art semiconductor devices, the content of the above metal impurities is particularly preferably 100 ppb by mass or less, and most preferably less than 10 ppb by mass, relative to the total mass of the cleaning composition. The lower limit is preferably 0 ppb by mass or more, relative to the total mass of the cleaning composition. In particular, the Cu ion content is preferably 10 ppb by mass or less, more preferably 0.5 ppb by mass or less, and even more preferably 0.2 ppb by mass or less, relative to the total mass of the cleaning composition. The lower limit is preferably 0 ppb by mass or more, relative to the total mass of the cleaning composition. The content of the above-mentioned metal impurities can be measured, for example, using ICP-MS (inductively coupled plasma mass spectrometry).
[0056] Methods for reducing the metal content include, for example, performing purification treatments such as distillation and filtration using ion exchange resins or filters at the stage of raw materials used in the manufacture of the cleaning composition or at a stage after the manufacture of the cleaning composition. Other methods for reducing metal content include using containers that minimize the elution of impurities, as described later, for storing raw materials or manufactured cleaning compositions. Additionally, fluororesin lining can be applied to the inner walls of pipes to prevent metal components from leaching out during the manufacturing of the cleaning composition.
[0057] <Inorganic particles and organic particles> The cleaning composition may contain at least one of inorganic particles and organic particles. The total content of inorganic and organic particles is preferably 1.0% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.01% by mass or less, based on the total mass of the cleaning composition. The lower limit is preferably 0% by mass or more, based on the total mass of the cleaning composition. The inorganic and organic particles contained in the cleaning composition include organic and inorganic solid particles contained as impurities in the raw materials, as well as organic and inorganic solid particles introduced as contaminants during the preparation of the cleaning composition, which ultimately remain as particles in the cleaning composition without dissolving. The content of inorganic and organic particles present in the cleaning composition can be measured in the liquid phase using a commercially available measuring device that employs a light scattering type liquid particle measurement method with a laser as the light source. Methods for removing inorganic and organic particles include, for example, purification processes such as filtering, which will be described later.
[0058] [Amine compounds] The cleaning composition may contain an amine compound. Amine compounds are compounds containing an amino group. The amino group contained in the above amine compound is at least one amino group selected from the group consisting of a primary amino group (-NH2), a secondary amino group (>NH), and a tertiary amino group (>N-). If an amine compound contains amino groups of multiple grades, it is classified as an amine compound containing the most advanced amino group. Specifically, an amine compound containing both a primary and a secondary amine group is classified as an amine compound containing a secondary amine group. Examples of amine compounds include aliphatic amines and amino alcohols (aliphatic amines having a hydroxyl group). The above amine compounds may be linear (linear or branched) or cyclic. Amine compounds are different compounds from those mentioned above (for example, chelating agents, etc.).
[0059] Amine compounds may be used individually or in combination of two or more. The amine compound content is preferably 0.01 to 90.0% by mass, more preferably 0.5 to 65.0% by mass, and even more preferably 1.0 to 25.0% by mass, based on the total mass of the cleaning composition.
[0060] [Corrosion inhibitor] The cleaning composition may contain a corrosion inhibitor. Examples of corrosion inhibitors include compounds having heteroatoms, with compounds having heterocyclic rings (heterocyclic compounds) being preferred, and compounds having polycyclic heterocyclic rings being more preferred. Preferred corrosion inhibitors are purine compounds, azole compounds, or reducing sulfur compounds. The corrosion inhibitor is preferably a compound different from the above-mentioned compounds that may be included in the cleaning composition.
[0061] The corrosion inhibitor may be used individually or in combination of two or more types. The content of the corrosion inhibitor is preferably 0.01 to 10.0% by mass, more preferably 1.0 to 10.0% by mass, and even more preferably 5.0 to 8.0% by mass, based on the total mass of the cleaning composition.
[0062] [Surfactants] The cleaning composition may contain a surfactant. The surfactant is a compound different from the compounds mentioned above (for example, sulfonic acid having an alkyl group with 9 to 18 carbon atoms). Surfactants are compounds that have both a hydrophilic group and a hydrophobic group (lipophilic group) in one molecule, and examples include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. When the cleaning composition contains a surfactant, the corrosion protection performance of the metal film and the removal of abrasive particles are improved.
[0063] Examples of surfactants include the compounds described in paragraphs
[0092] to
[0096] of Japanese Patent Publication No. 2015-158662, paragraphs
[0045] to
[0046] of Japanese Patent Publication No. 2012-151273, and paragraphs
[0014] to
[0020] of Japanese Patent Publication No. 2009-147389, the contents of which are incorporated herein by reference.
[0064] Surfactants may be used individually or in combination of two or more types. The surfactant content is preferably 0.001 to 8.0% by mass, more preferably 0.005 to 5.0% by mass, and even more preferably 0.01 to 3.0% by mass, relative to the total mass of the cleaning composition, in order to achieve a well-balanced and excellent performance of the cleaning composition.
[0065] [pH adjuster] Examples of pH adjusting agents include quaternary ammonium compounds, basic compounds, and acidic compounds, with quaternary ammonium compounds, sulfuric acid, or potassium hydroxide being preferred. The pH of the cleaning composition may be adjusted by adjusting the amount of each of the above-mentioned components added. Examples of pH adjusters include paragraphs
[0053] and
[0054] of International Publication No. 2019-151141, and paragraph
[0021] of International Publication No. 2019-151001, the contents of which are incorporated herein by reference.
[0066] pH adjusters may be used individually or in combination of two or more types. The pH adjusting agent content is preferably 0.01 to 10.0% by mass, more preferably 0.05 to 5.0% by mass, and even more preferably 0.05 to 3.0% by mass, based on the total mass of the washing solution.
[0067] [Phosphate ions] The cleaning composition preferably contains phosphate ions. Phosphate ions may be present as impurities in each of the above components. The phosphate ion content is preferably 0.001 to 1.0% by mass, more preferably 0.001 to 0.1% by mass, and even more preferably 0.001 to 0.01% by mass, based on the total mass of the cleaning composition. One example of a method for measuring the phosphate ion content is the method for measuring the content of each component in the cleaning composition described later. Methods for adjusting the phosphate ion content include, for example, purifying the components contained in the cleaning composition and the adjusted cleaning composition using distillation and ion exchange resins.
[0068] [Other ingredients] The cleaning composition may contain other ingredients. Other components include, for example, polymers, oxidizing agents, polyhydroxy compounds with a molecular weight of 500 or more, fluorine compounds, and organic solvents. Other ingredients may be used individually or in combination of two or more.
[0069] The content of each of the above components in the washing composition can be measured by known methods such as gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), and ion-exchange chromatography (IC).
[0070] [Manufacturing of cleaning compositions] The cleaning composition can be manufactured by known methods. The method for producing the cleaning composition preferably includes a liquid preparation step.
[0071] [Liquid preparation process] The preparation step for the cleaning composition is, for example, the step of preparing the cleaning composition by mixing the components that may be included in the cleaning composition described above. The order and timing of mixing the above components are not particularly limited. For example, a preparation step involves sequentially adding polycarboxylic acid, a chelating agent, a specific sulfonic acid, and, if necessary, an optional component such as an amine compound, to a container containing purified water, stirring, and then adding a pH adjuster as needed to prepare the solution. The method of adding the purified water and the above components to the container may be either a single addition or a divided addition.
[0072] Methods for stirring the cleaning composition during the preparation process include, for example, using a known stirrer or a known disperser. Examples of the above-mentioned agitators include industrial mixers, portable agitators, mechanical stirrers, and magnetic stirrers. Examples of the above-mentioned dispersers include industrial dispersers, homogenizers, ultrasonic dispersers, and bead mills.
[0073] The mixing of the above components in the liquid preparation process of the cleaning composition, the purification process described later, and the storage temperature of the manufactured cleaning composition are preferably 40°C or lower, more preferably 30°C or lower. The lower limit is preferably 5°C or higher, more preferably 10°C or higher. When the temperature is within the above range, the storage stability of the cleaning composition is excellent.
[0074] <Purification process> Preferably, at least one of the raw materials of the cleaning composition is subjected to a purification process before the liquid preparation step. The purity of the raw material after purification is preferably 99% by mass or higher, and more preferably 99.9% by mass or higher. The upper limit is preferably 99.9999% by mass or lower.
[0075] Examples of purification processes include distillation, as well as known methods such as ion exchange resins, RO membranes (Reverse Osmosis Membranes), and filtering processes described later. The purification process may be carried out by combining multiple of the above purification methods. For example, after performing a primary purification process in which the raw material is passed through an RO membrane, a secondary purification process may be carried out in which the obtained raw material is passed through a purification apparatus consisting of a cation exchange resin, anion exchange resin, or mixed-bed ion exchange resin. Furthermore, the purification process may be carried out multiple times.
[0076] Examples of filters used for filtering include well-known filtration filters. Suitable filter materials include, for example, fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), polyamide resins such as nylon, and polyolefin resins (including high-density or ultra-high molecular weight) such as polyethylene and polypropylene (PP), which are effective in removing highly polar foreign substances that are prone to causing defects. Among these, polyethylene, polypropylene (including high-density polypropylene), fluororesins (including PTFE and PFA), and polyamide resins (including nylon) are preferred, with fluororesins being more preferred.
[0077] The critical surface tension of the filter is preferably 70 to 95 mN / m, and more preferably 75 to 85 mN / m. When the critical surface tension is within the above range, highly polar foreign matter that is likely to cause defects can be removed. The critical surface tension of the filter is the manufacturer's nominal value.
[0078] The pore size of the filter is preferably 2 to 20 nm, and more preferably 2 to 15 nm. When the filter pore size is within the above range, clogging of the filter can be suppressed, and fine foreign matter such as impurities and aggregates can be removed. The filter pore size is the nominal value of the manufacturer.
[0079] Filtering may be performed once or more times. When filtering is performed two or more times, the filters used for filtering may be the same or different.
[0080] The filtering temperature is preferably below room temperature (25°C), more preferably below 23°C, and even more preferably below 20°C. The lower limit is preferably above 0°C, more preferably above 5°C, and even more preferably above 10°C. When filtering is performed within the above range, foreign matter and impurities dissolved in the raw material can be removed.
[0081] <Container> The cleaning composition (including the form of the diluted cleaning composition described later) can be filled into any container and stored, transported, and used, as long as it does not corrode the container.
[0082] As for the container, a container with a high degree of cleanliness inside, suitable for semiconductor applications, and in which the elution of impurities from the inner wall of the container's containment area into the cleaning composition is suppressed is preferred. Examples of the above-mentioned containers include commercially available containers for semiconductor cleaning compositions. Specifically, these include the Clean Bottle series (manufactured by Aicello Chemical Co., Ltd.) and the Pure Bottle (manufactured by Kodama Resin Industry Co., Ltd.). Furthermore, as a container, it is preferable that the parts of the container that come into contact with the cleaning composition, such as the inner wall of the container's storage section, are made of fluororesin (perfluororesin) or metal that has been treated with rust prevention and metal leaching prevention. The inner wall of the container is preferably formed from at least one resin selected from the group consisting of polyethylene resin, polypropylene resin, and polyethylene-polypropylene resin, or a resin different from the above resins, or from a metal that has been treated with rust prevention and metal leaching prevention treatment, such as stainless steel, Hastelloy, Inconel, and Monel.
[0083] As the different resins mentioned above, fluororesins (perfluororesins) are preferred. Containers with an inner wall made of fluororesin can suppress the elution of ethylene and propylene oligomers compared to containers with an inner wall made of polyethylene resin, polypropylene resin, or polyethylene-polypropylene resin. Examples of containers with fluororesin inner walls include the FluoroPurePFA composite drum (manufactured by Entegris), the containers described on page 4 of Japanese Patent Publication No. 3-502677, page 3 of International Publication No. 2004 / 016526, and pages 9 and 16 of the International Publication No. 99 / 46309.
[0084] In addition to the fluororesin mentioned above, quartz and electropolished metal materials (electropolished metal materials) are also preferred for the inner wall of the container. The metal material used in the manufacture of the electropolished metal material described above preferably contains at least one selected from the group consisting of chromium and nickel, and the total content of chromium and nickel is more than 25% by mass of the total mass of the metal material. Examples include stainless steel and nickel-chromium alloys. The total chromium and nickel content in the metallic material is more preferably 30% by mass or more, relative to the total mass of the metallic material. The upper limit is preferably 90% by mass or less.
[0085] Examples of methods for electropolishing metal materials include known methods. For example, the methods described in paragraphs
[0011] to
[0014] of Japanese Patent Publication No. 2015-227501 and paragraphs
[0036] to
[0042] of Japanese Patent Publication No. 2008-264929 are examples.
[0086] It is preferable that the inside of the container be cleaned before filling it with the cleaning composition. Examples of cleaning methods include known methods. It is preferable that the liquid used for cleaning has a reduced amount of metal impurities. The cleaning composition may be bottled in containers such as gallon bottles and coated bottles after manufacturing for transportation and storage.
[0087] During storage, it is preferable to replace the container with an inert gas (e.g., nitrogen and argon, etc.) with a purity of 99.99995% by volume or higher to prevent changes in the components of the cleaning composition, and an inert gas with a low water content is even more preferable. The temperature during transport and storage may be controlled to ambient temperature, or to -20°C to 20°C to prevent deterioration.
[0088] [Dilution process] The cleaning composition may be used for cleaning after undergoing a dilution step in which it is diluted with a diluent such as water, and then as a diluted cleaning composition (diluted cleaning composition). A diluted cleaning composition is a form of the cleaning composition of the present invention, insofar as it satisfies the requirements of the present invention.
[0089] The dilution ratio of the cleaning composition in the dilution step can be appropriately adjusted depending on the type and content of each component that may be included in the cleaning composition, as well as the semiconductor substrate or the like to be cleaned. The dilution ratio of the diluted cleaning composition to the undiluted cleaning composition is preferably 10 to 10,000 times by mass ratio or volume ratio (volume ratio at 23°C), more preferably 20 to 3,000 times, and even more preferably 50 to 1,000 times. Because it offers superior defect suppression performance, the cleaning composition is preferably diluted with water. In other words, the cleaning composition (diluted cleaning composition) may also contain each component (excluding water) in an amount obtained by dividing the preferred content of each component that can be contained in the cleaning composition by the dilution ratio within the above range (for example, 100). To put it another way, the preferred content of each component (excluding water) relative to the total mass of the diluted cleaning composition is, for example, the amount described as the preferred content of each component relative to the total mass of the cleaning composition (cleaning composition before dilution) divided by the dilution ratio within the above range (for example, 100).
[0090] The change in pH before and after dilution (the difference between the pH of the cleaning composition before dilution and the pH of the diluted cleaning composition) is preferably 2.5 or less, more preferably 1.8 or less, and even more preferably 1.5 or less. The lower limit is preferably 0.1 or more. The pH of the cleaning composition before dilution and the pH of the diluted cleaning composition are preferably as described above.
[0091] The dilution step may be carried out in accordance with the liquid preparation step of the cleaning composition described above. Examples of stirring devices and stirring methods used in the dilution step include the known stirring devices and stirring methods used in the liquid preparation step described above.
[0092] It is preferable that the water used in the dilution process be purified before use. It is also preferable to perform a purification process on the diluted washing composition obtained in the dilution process. Purification treatments include ion component reduction treatment using ion exchange resin or RO membrane, and foreign matter removal using filtering, and it is preferable to carry out one of these treatments.
[0093] [Cleanroom] It is preferable that the manufacturing of the cleaning composition, the opening and cleaning of the container, the handling of the cleaning composition including filling, the treatment analysis, and the measurements all be carried out in a cleanroom. The cleanroom preferably meets the 14644-1 cleanroom standard. It is preferable that it meets one of the ISO (International Organization for Standardization) Class 1, ISO Class 2, ISO Class 3, and ISO Class 4 standards, more preferably ISO Class 1 or ISO Class 2, and even more preferably ISO Class 1.
[0094] [Uses of cleaning compositions] The cleaning composition is preferably used in a cleaning process for cleaning semiconductor substrates, and more preferably in a cleaning process for cleaning semiconductor substrates that have undergone CMP treatment. Furthermore, the cleaning composition can also be used for cleaning semiconductor substrates in the semiconductor substrate manufacturing process. As described above, a diluted cleaning composition obtained by diluting a cleaning composition may be used for cleaning semiconductor substrates.
[0095] In addition to the above-mentioned uses, the cleaning composition of the present invention is also suitably used for, for example, metal cleaning after grinding, cleaning in LED manufacturing, cleaning bumps in TSVs, cleaning high-density package substrates, and cleaning wafer hoops (FOUP: Front Opening Unify Pod).
[0096] [Objects to be cleaned] Examples of objects to be cleaned by the cleaning composition include semiconductor substrates (for example, semiconductor substrates containing metals). Examples of semiconductor substrates containing Cu include semiconductor substrates having Cu-containing metal wiring and / or Cu-containing plug materials.
[0097] Examples of metals included in the metal-containing material include at least one metal M selected from the group consisting of Cu (copper), Al (aluminum), Ru (ruthenium), Co (cobalt), W (tungsten), Ti (titanium), Ta (tantalum), Cr (chromium), Hf (hafnium), Os (osmium), Pt (platinum), Ni (nickel), Mn (manganese), Zr (zirconium), palladium (Pd), Mo (molybdenum), La (lanthanum), and Ir (iridium).
[0098] A metal-containing substance can be any substance that contains a metal (metal atom), for example, elemental metal M, alloys containing metal M, oxides of metal M, nitrides of metal M, and oxynitrides of metal M. The metal-containing material may be a mixture containing two or more of these compounds. The above oxide, above nitride, and above oxynitride may be any of a composite oxide containing a metal, a composite nitride containing a metal, or a composite oxynitride containing a metal. The metal atom content of the metal-containing material is preferably 10% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more, relative to the total mass of the metal-containing material. The upper limit is preferably 100% by mass or less.
[0099] The semiconductor substrate preferably has a metal M-containing material containing metal M, more preferably has a metal-containing material containing at least one metal selected from the group consisting of Cu, Al, W, Co, Ti, Ta, Ru, and Mo, even more preferably has a metal-containing material containing at least one metal selected from the group consisting of Cu, Al, W, Co, Ru, and Mo, and particularly preferably has a metal-containing material containing Cu metal.
[0100] Examples of semiconductor substrates that are the target of cleaning with the cleaning composition include substrates having a metal wiring film, a barrier metal, and an insulating film on the surface of the wafer that constitutes the semiconductor substrate.
[0101] Examples of wafers that constitute a semiconductor substrate include wafers made of silicon-based materials such as silicon (Si) wafers, silicon carbide (SiC) wafers, and silicon-containing resin wafers (glass epoxy wafers), as well as gallium phosphide (GaP) wafers, gallium arsenide (GaAs) wafers, and indium phosphide (InP) wafers. Examples of silicon wafers include n-type silicon wafers doped with pentavalent atoms (e.g., phosphorus (P), arsenic (As), and antimony (Sb)), and p-type silicon wafers doped with trivalent atoms (e.g., boron (B) and gallium (Ga)). Examples of silicon used 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.
[0102] The semiconductor substrate may have an insulating film on the wafer. Examples of insulating films include silicon oxide films (e.g., silicon dioxide (SiO2) films and tetraethyl orthosilicate (Si(OC2H5)4) films (TEOS films), etc.), silicon nitride films (e.g., silicon nitride (Si3N4) and silicon carbide nitride (SiNC), etc.), and low-dielectric constant (Low-k) films (e.g., carbon-doped silicon oxide (SiOC) films and silicon carbide (SiC) films, etc.), with low-dielectric constant (Low-k) films being preferred.
[0103] The metal-containing material may also preferably be a metal film containing metal. The metal film on the semiconductor substrate is preferably a metal film containing metal M, more preferably a metal film containing at least one metal selected from the group consisting of Cu, Al, W, Co, Ti, Ta, Ru, and Mo, even more preferably a metal film containing at least one metal selected from the group consisting of Cu, Al, W, Co, Ru, and Mo, and particularly preferably a metal film containing Cu metal. Examples of metal films containing at least one metal selected from the group consisting of Cu, Al, W, Co, Ru, and Mo include films mainly composed of copper (Cu-containing films), films mainly composed of aluminum (Al-containing films), films mainly composed of tungsten (W-containing films), films mainly composed of cobalt (Co-containing films), films mainly composed of ruthenium (Ru-containing films), and films mainly composed of molybdenum (Mo-containing films). The main component refers to the component that is present in the largest quantity among the components of the metal film.
[0104] Examples of Cu-containing films include wiring films made solely of metallic Cu (Cu wiring films) and wiring films made of alloys consisting of metallic Cu and other metals (Cu alloy wiring films). Examples of Cu alloy wiring films include wiring films made of an alloy of Cu and at least one metal selected from the group consisting of Al, Ti, Cr, Mn, Ta, and W. Specifically, examples include Cu-Al alloy wiring films, Cu-Ti alloy wiring films, Cu-Cr alloy wiring films, Cu-Mn alloy wiring films, Cu-Ta alloy wiring films, and Cu-W alloy wiring films.
[0105] Examples of Al-containing films (metal films with Al as the main component) include metal films made solely of metallic Al (Al metal films) and metal films made of alloys of Al and other metals (Al alloy metal films).
[0106] Examples of W-containing films (metal films with W as the main component) include metal films made solely of metal W (W metal films) and metal films made of alloys of W and other metals (W alloy metal films). W-containing films are used, for example, at connections between barrier metals or vias and wiring.
[0107] Examples of Co-containing films (metal films with Co as the main component) include metal films made solely of metallic Co (Co metal films) and metal films made of alloys consisting of metallic Co and other metals (Co alloy metal films). Examples of Co alloy metal films include metal films made of an alloy consisting of at least one metal selected from the group consisting of Ti, Cr, Fe, Ni, Mo, Pd, Ta, and W, and cobalt. Specifically, these include Co-Ti alloy metal films, Co-Cr alloy metal films, Co-Fe alloy metal films, Co-Ni alloy metal films, Co-Mo alloy metal films, Co-Pd alloy metal films, Co-Ta alloy metal films, and Co-W alloy metal films.
[0108] Examples of Ru-containing films include metal films made solely of metallic Ru (Ru metal films) and metal films made of alloys of metallic Ru and other metals (Ru alloy metal films). Ru-containing films are often used as barrier metals.
[0109] Examples of Mo-containing films include metal films made solely of metallic Mo (Mo metal films) and metal films made of alloys consisting of metallic Mo and other metals (Mo alloy metal films).
[0110] Further, it is preferable to use the cleaning composition for cleaning a substrate having a metal film (cobalt barrier metal) composed only of metal Co, which is a barrier metal for a copper-containing wiring film, and at least a copper-containing wiring film on the upper part of a wafer constituting a semiconductor substrate, wherein the copper-containing wiring film and the cobalt barrier metal are in contact with each other on the substrate surface.
[0111] As a method for forming the insulating film, the Ru-containing film, the W-containing film, the Cu-containing film, and the Co-containing film on the wafer constituting the semiconductor substrate, known methods can be mentioned. As a method for forming the insulating film, for example, a silicon oxide film is formed by heat-treating a wafer constituting a semiconductor substrate in the presence of oxygen gas, and then a silicon nitride film is formed by the chemical vapor deposition (CVD) method by flowing gases of silane and ammonia. As a method for forming the Ru-containing film, the W-containing film, the Cu-containing film, and the Co-containing film, for example, a circuit is formed on the wafer having the insulating film by a known method such as a resist, and then the Ru-containing film, the W-containing film, the Cu-containing film, and the Co-containing film are formed by methods such as plating and the CVD method.
[0112] <CMP process> The CMP process is a process for planarizing the surface of a substrate having a metal wiring film, a barrier metal, and an insulating film by a combined action of chemical action using a polishing slurry containing polishing fine particles (abrasive grains) and mechanical polishing. On the surface of the semiconductor substrate subjected to the CMP process, impurities such as abrasive grains (for example, silica and alumina, etc.) used in the CMP process, metal impurities (metal residues, particularly copper-containing metal residues) derived from the polished metal wiring film and the barrier metal may remain. Also, organic impurities derived from the CMP process liquid used during the CMP process may remain. Since these impurities may, for example, cause a short circuit between wirings and deteriorate the electrical characteristics of the semiconductor substrate, the semiconductor substrate subjected to the CMP process is subjected to a cleaning process for removing these impurities from the surface. Examples of semiconductor substrates that have undergone CMP treatment include the CMP-treated substrates described in the Journal of the Japan Society for Precision Engineering, Vol. 84, No. 3, 2018.
[0113] <Buff polishing process> The surface of the semiconductor substrate, which is the object to be cleaned by the cleaning composition, may be subjected to CMP treatment followed by buff polishing. Buff polishing is a process that uses a polishing pad to reduce impurities on the surface of a semiconductor substrate. Specifically, the surface of a semiconductor substrate that has undergone CMP (Chemical Polishing) treatment is brought into contact with a polishing pad, and a buff polishing composition is supplied to the contact area while the semiconductor substrate and the polishing pad are slid relative to each other. As a result, impurities on the surface of the semiconductor substrate are removed by the frictional force of the polishing pad and the chemical action of the buff polishing composition.
[0114] As for the buffing composition, known buffing compositions can be used as appropriate depending on the type of semiconductor substrate and the type and amount of impurities to be removed. Examples of components included in the buffing composition include water-soluble polymers such as polyvinyl alcohol, and water and acids such as nitric acid as dispersion media. Furthermore, as a buffing treatment, it is preferable to apply the above-mentioned cleaning composition as a buffing composition to the semiconductor substrate. The polishing apparatus and polishing conditions used in the buffing process can be appropriately selected from known apparatus and conditions depending on the type of semiconductor substrate and the material to be removed. Examples of buffing processes include those described in paragraphs
[0085] to
[0088] of International Publication No. 2017 / 169539, and these contents are incorporated herein by reference.
[0115] [Washing method] A preferred cleaning method using a cleaning composition is one that cleans a semiconductor substrate. The method for cleaning a semiconductor substrate is not particularly limited, as long as it includes a cleaning step of cleaning the semiconductor substrate using the above-mentioned cleaning composition. As the semiconductor substrate mentioned above, a semiconductor substrate that has undergone CMP treatment is preferred. The method for cleaning a semiconductor substrate may also preferably include a step of applying the diluted cleaning composition obtained in the above dilution step to a semiconductor substrate that has undergone CMP treatment and cleaning it.
[0116] A known cleaning process for cleaning a semiconductor substrate using a cleaning composition includes, for example, a known method performed on a semiconductor substrate that has undergone CMP treatment. Specifically, in scrub cleaning, which involves supplying a cleaning composition to the semiconductor substrate while physically contacting a cleaning member such as a brush with the surface of the semiconductor substrate to remove residues, immersion cleaning, spin (dropping) cleaning, which involves rotating the semiconductor substrate while dropping the cleaning composition, and spray cleaning, it is preferable to apply ultrasonic treatment to the cleaning composition in which the semiconductor substrate is immersed, as this can further reduce impurities remaining on the surface of the semiconductor substrate. The above cleaning process may be performed once or more times. If cleaning is performed more than once, the same method may be repeated, or different methods may be combined.
[0117] The semiconductor substrate cleaning method may be either a single-wafer method or a batch method. The single-wafer processing method processes semiconductor substrates one at a time, while the batch processing method processes multiple semiconductor substrates simultaneously.
[0118] The temperature of the cleaning composition used for cleaning semiconductor substrates is not particularly limited. For example, room temperature (25°C) is acceptable. However, from the viewpoint of improving cleanability and suppressing damage to the components, 10 to 60°C is preferred, and 15 to 50°C is more preferred.
[0119] The pH of the cleaning composition and the pH of the diluted cleaning composition are preferably the above-described preferred pH values.
[0120] The cleaning time for cleaning semiconductor substrates can be appropriately changed depending on the type and content of components contained in the cleaning composition. The cleaning time is preferably 10 to 120 seconds, more preferably 20 to 90 seconds, and even more preferably 30 to 60 seconds.
[0121] The supply rate (feed rate) of the cleaning composition in the semiconductor substrate cleaning process is preferably 50 to 5000 mL / min, and more preferably 500 to 2000 mL / min.
[0122] In cleaning semiconductor substrates, a mechanical stirring method may be used to further enhance the cleaning ability of the cleaning composition. Examples of mechanical stirring methods include circulating the cleaning composition on a semiconductor substrate, flowing or spraying the cleaning composition on a semiconductor substrate, and stirring the cleaning composition with ultrasound or megasonic waves.
[0123] After cleaning the semiconductor substrate as described above, a rinsing step may be performed in which the semiconductor substrate is rinsed with a solvent to clean it. The rinsing step is performed immediately after the semiconductor substrate cleaning step, and preferably involves rinsing with a rinsing solvent (rinsing solution) for 5 to 300 seconds. The rinsing step may also be carried out using the mechanical stirring method described above.
[0124] Examples of rinsing solvents include water (preferably deionized water), methanol, ethanol, isopropyl alcohol, N-methylpyrrolidinone, γ-butyrolactone, dimethyl sulfoxide, ethyl lactate, and propylene glycol monomethyl ether acetate. Alternatively, an aqueous rinsing solution with a pH greater than 8.0 (such as diluted aqueous ammonium hydroxide) may be used. One method for bringing the rinsing solvent into contact with the semiconductor substrate is to bring the above-mentioned cleaning composition into contact with the semiconductor substrate.
[0125] After the rinsing process described above, a drying process may be performed to dry the semiconductor substrate. Examples of drying methods include spin drying, passing a drying gas over a semiconductor substrate, heating the substrate using heating means such as a hot plate and an infrared lamp, Marangoni drying, Rotagoni drying, IPA (isopropyl alcohol) drying, and combinations thereof.
[0126] The following describes in detail the various uses of the above-mentioned cleaning composition, specifically: a cleaning solution for semiconductor substrates (preferably semiconductor substrates that have undergone CMP treatment), a cleaning solution for brushes used to clean semiconductor substrates, a cleaning solution for polishing pads used to process semiconductor substrates, and a cleaning solution for buffing CMP-treated semiconductor substrates. The semiconductor substrate used for the above-mentioned applications is not particularly limited as long as it is one of the semiconductor substrates described above, but a semiconductor substrate containing tungsten is preferred, and a semiconductor substrate having a W-containing film is more preferred.
[0127] [Primary Use: Cleaning of semiconductor substrates that have undergone CMP treatment] This composition can be used as a cleaning solution for semiconductor substrates in a semiconductor substrate cleaning method that includes a step of cleaning a semiconductor substrate that has been subjected to CMP treatment (hereinafter also referred to as "First Use"). That is, this composition can be used as a cleaning solution used for cleaning a semiconductor substrate that has been subjected to CMP treatment in a semiconductor device manufacturing method that includes a step of applying CMP treatment to a semiconductor substrate and a step of cleaning a semiconductor substrate that has been subjected to CMP treatment. This composition can be applied to known methods performed on CMP-treated semiconductor substrates. The composition used for the first application may be the diluent obtained in the above dilution step, and it is also preferable to have a step of applying the diluent to a semiconductor substrate that has undergone CMP treatment and cleaning it.
[0128] The cleaning process for cleaning a semiconductor substrate that has undergone CMP treatment includes the cleaning method described above.
[0129] [Second use: Cleaning cleaning brushes] This composition can be used as a cleaning solution for cleaning brushes in a cleaning method for cleaning semiconductor substrates, which includes a step of cleaning the cleaning brushes (hereinafter also referred to as "second use"). Examples of cleaning brushes for the second application include known brushes used for scrubbing, which removes residues and other debris by physically contacting the surface of a semiconductor substrate. Preferably, the cleaning brush is one used for cleaning semiconductor substrates that have undergone CMP (Chemical Polishing).
[0130] The shape of the cleaning brush is not particularly limited; for example, cylindrical roll-type brushes and pencil-type brushes are examples, with roll-type brushes being preferred. Cleaning brushes often have numerous cylindrical protrusions projecting radially from their surface. Examples of materials that make up the cleaning brush include polymer resins having hydroxyl groups, such as polyvinyl alcohol (PVA) resin, polyurethane resin, and polyolefin resin. A cleaning brush made of a sponge-like substance of the above polymer resin is preferred, and a cleaning brush made of a sponge-like substance of PVA resin is more preferred. Examples of commercially available cleaning brushes include those manufactured by Entegris (e.g., model number "PVP1ARXR1") and those manufactured by AION (Bell Eater® A series).
[0131] As a cleaning method for the cleaning brush using the composition, known methods used in the field of semiconductor device manufacturing, such as immersion and spraying methods described as cleaning steps for semiconductor substrates in the first application above, may be appropriately adopted. Furthermore, the cleaning conditions, including the temperature of the cleaning solution and the cleaning time, can be appropriately selected based on the constituent materials of the cleaning brush, etc., by referring to the cleaning conditions in the semiconductor substrate cleaning process described above and known cleaning methods.
[0132] The preferred embodiments of the composition used for the second application are as follows: The pH of the composition is preferably within the preferred range of the pH of the composition described above. The composition used for the second use may be the diluted solution obtained in the above dilution step. When using a diluted solution, the dilution ratio is preferably 10 to 100 times, more preferably 30 to 100 times, in terms of mass ratio. The pH of the diluted solution is preferably within the preferable range of the pH of the above diluted solution.
[0133] [Third Use: Cleaning of Polishing Pad] This composition can be used as a cleaning solution for a polishing pad in a method for cleaning a polishing pad having a step of cleaning a polishing pad used for processing a semiconductor substrate (hereinafter, also referred to as "third use"). The polishing pad to be cleaned for the third use is not particularly limited as long as it is a known polishing pad used for processing a semiconductor substrate, and examples include the polishing pads described in the above <CMP Process>. Among them, a polishing pad containing a polyurethane resin is preferable. Also, as the polishing pad, a polishing pad used for CMP processing is preferable.
[0134] As the method for cleaning the polishing pad, known methods such as the immersion type and spray type described as the cleaning step of the semiconductor substrate in the first use in the field of semiconductor device manufacturing are appropriately adopted. Also, regarding the cleaning conditions including the temperature and cleaning time of the cleaning solution, they can be appropriately selected based on the constituent materials of the polishing pad, etc., by referring to the cleaning conditions and known cleaning methods in the cleaning step of the semiconductor substrate.
[0135] The preferred embodiments of the composition used for the third use are as follows. The pH of the composition is preferably within the preferable range of the pH of the above composition. The composition used for the third use may be the diluted solution obtained in the above dilution step. When using a diluted solution, the dilution ratio is preferably 10 to 100 times, more preferably 30 to 100 times, still more preferably 50 to 100 times, in terms of mass ratio. The pH of the diluted solution is preferably within the preferable range of the pH of the above diluted solution.
[0136] [Fourth Use: Buff Cleaning] This composition can be used as a cleaning liquid for buff cleaning in a method for cleaning a semiconductor substrate having a buff cleaning step of contacting a polishing pad with the surface of a semiconductor substrate subjected to CMP processing to clean the surface of the semiconductor substrate (hereinafter, also referred to as "Fourth Use"). The specific method of buff cleaning for the Fourth Use is as already described in the above <Buff Cleaning>. Also, the polishing pad used for the buff cleaning of the Fourth Use is as already described in the above <CMP Processing>.
[0137] Preferred embodiments of the composition used for the Fourth Use are as follows. The pH of the composition is preferably within the preferred range of the pH of the above composition. The composition used for the Fourth Use may be the dilution liquid obtained in the above dilution step. When using a dilution liquid, the dilution ratio is preferably 10 to 100 times, more preferably 30 to 100 times, and still more preferably 50 to 100 times in terms of mass ratio. The pH of the dilution liquid is preferably within the preferred range of the pH of the above dilution liquid. The composition preferably does not substantially contain abrasive grains and coarse particles.
[0138] [Other Uses] This composition can also be used for uses different from any of the cleaning of a semiconductor substrate subjected to CMP processing, the cleaning of a cleaning brush used for cleaning a semiconductor substrate, the cleaning of a polishing pad used for processing a semiconductor substrate, and the buff cleaning of a semiconductor substrate subjected to CMP processing.
[0139] <Cleaning of a Semiconductor Substrate Subjected to Back Grinding> For the purpose of miniaturization and thinning of semiconductor devices, a technique (back grinding) for reducing the thickness of a wafer by grinding the surface on the opposite side of the circuit formation surface of a semiconductor substrate is known. This composition can be used as a cleaning solution in a cleaning process for cleaning semiconductor substrates that have undergone back grinding. By using this composition, residues generated by back grinding and etching processes associated with back grinding can be removed.
[0140] <Cleaning of etched semiconductor substrates> In the semiconductor device manufacturing process, when the metal layer and / or insulating layer of a semiconductor substrate are etched by plasma etching using a resist pattern as a mask, residues originating from the photoresist, metal layer, and insulating layer are generated on the semiconductor substrate. Furthermore, when the unwanted resist pattern is removed by plasma ashing, residues originating from the ashed photoresist are also generated on the semiconductor substrate. This composition can be used as a cleaning solution in a cleaning process for cleaning an etched semiconductor substrate. By using this composition, etching residues and / or ashing residues generated on the etched semiconductor substrate can be removed.
[0141] <Cleaning of flux residue on semiconductor substrates> When mounting electronic components onto a semiconductor substrate by soldering, flux (an accelerator) is used to remove oxides that hinder the connection between metals such as electrodes or wiring and the solder metal, thereby promoting connection. In substrates where electronic components have been soldered using flux, and / or substrates where solder bumps for soldering electronic components have been formed using flux, residues derived from the flux may remain. This composition can be used as a cleaning solution for semiconductor substrates on which electronic components have been soldered using flux, or for semiconductor substrates on which solder bumps have been formed using flux. By using this composition, residual flux-derived material remaining on the semiconductor substrate can be removed.
[0142] <Cleaning of bonded semiconductor substrates> In the semiconductor device manufacturing process, semiconductor chips manufactured by cutting (dicing) a wafer to a predetermined size are picked up one by one by a dicing film and sent to the next bonding process. During this dicing process, foreign matter such as wafer cutting debris and dicing film cutting debris adheres to the surface of the semiconductor chip. In particular, in bonding processes such as flip-chip bonding, which connects the semiconductor chip to a substrate via terminals placed on the surface of the semiconductor chip, or direct bonding, which directly bonds one semiconductor chip onto another, it is known that the bonding quality deteriorates due to minute foreign matter of a few micrometers or less. Therefore, a cleaning process is performed to remove foreign matter from the semiconductor chips that will be subjected to the bonding process. This composition can be used as a cleaning solution in a cleaning process to clean semiconductor chips before they are subjected to the bonding process. By using this composition, foreign matter such as cutting debris generated in the dicing process before the bonding process can be removed from the semiconductor chip.
[0143] <Cleaning of plastic products> This composition can be used for cleaning resin products, particularly resin containers used for housing and transporting semiconductor substrates in the manufacturing process of semiconductor devices. When semiconductor substrates are stored and transported, containers are used to prevent particle intrusion and chemical contamination. Examples of such containers include FOSBs (Front Opening Shipping Boxes) used when delivering wafers to semiconductor device manufacturers, and FOUPs (Front Opening Unified Pods) and SMIFs (Standard Mechanical Interfaces) used to store wafers for transport between wafer processing steps. However, when semiconductor substrates are repeatedly stored in and removed from these containers, metal impurities may be generated due to contact between the semiconductor substrate and the inside of the container. In addition, residues generated during the semiconductor device manufacturing process and remaining on the semiconductor substrate may contaminate the inside of the container. To prevent these metal impurities and residues from adhering to the semiconductor substrate, the inside of the container is cleaned. By using this composition to clean the above-mentioned container, the etching residue and / or ashing residue generated on the etched semiconductor substrate can be removed.
[0144] <Cleaning of glass substrates> This composition can be used as a cleaning solution for glass substrates, particularly flat panel displays such as liquid crystal displays, plasma displays, organic EL displays, and touch panels, as well as glass substrates suitable for hard disks. By using this composition, residual substances such as metal impurities remaining on the glass substrate can be removed.
[0145] <Etching process> This composition can be used in etching processes to remove metal films on semiconductor substrates. Examples of etching processes include methods that involve contacting the semiconductor substrate with the composition to dissolve and remove metal-containing materials on the substrate. The method of contacting the semiconductor substrate with the composition is not particularly limited, and the methods described in the first application can be applied. For specific embodiments of the etching process, refer to paragraphs
[0049] to
[0069] of International Publication No. 2019 / 138814, which are incorporated herein by reference.
[0146] [Manufacturing method for semiconductor element] The method for manufacturing semiconductor devices is not particularly limited as long as it uses the cleaning method described above, and known methods for manufacturing semiconductor devices can be used. [Examples]
[0147] The present invention will be described in more detail below based on examples. The materials, amounts, and proportions shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the examples shown below.
[0148] In the following examples, the pH of the cleaning composition was measured at 25°C using a pH meter (Horiba, Ltd., F-74) in accordance with JIS Z8802-1984. The electrical conductivity was measured at 25°C using an electrical conductivity meter (electrical conductivity meter: portable type D-70 / ES-70 series, Horiba, Ltd.). Furthermore, in the preparation of the cleaning compositions in the examples and comparative examples, the handling of containers, preparation of the cleaning compositions, filling, storage, and analytical measurements were all carried out in a cleanroom meeting ISO Class 2 or lower standards.
[0149] [Ingredients for cleaning compositions] The following components were used to manufacture the cleaning composition. All components used in the examples were classified as semiconductor grade or equivalent high-purity grade.
[0150] [Polycarboxylic acid] • Citric acid Oxalic acid ·Tartaric acid • Malic acid • Maleic acid
[0151] [Chelating agent] HEDPO: 1-hydroxyethane-1,1-diphosphonic acid • EDTMP: Ethylenediaminetetramethylenephosphonic acid • EDTA: Ethylenediaminetetraacetic acid
[0152] [Specific sulfonic acids]
[0153] [ka]
[0154] 〔water〕 • Water: Ultrapure water (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
[0155] [Manufacturing of cleaning compositions] The cleaning composition of Example 1 was obtained by adding citric acid, HEDPO, and sulfonic acids A to D to ultrapure water in amounts such that the final cleaning composition would have the formulations shown in the table below, and then stirring thoroughly. The cleaning compositions other than those in Example 1 were each manufactured according to the manufacturing method of Example 1. Furthermore, the resulting cleaning composition did not contain any inorganic or organic particles.
[0156] [evaluation] [Cu ions] The Cu ions were prepared by pre-purifying each component. In the above purification method, the substance to be purified was passed through an ion exchange resin membrane (IonClean SL DFA1SRPESW44, manufactured by Nippon Pall Co., Ltd.) until the desired content was reached. The Cu ion content was measured using an Agilent 8800 triple quadrupole ICP-MS (for semiconductor analysis, option #200) under the following measurement conditions. (Measurement conditions) A quartz torch, a coaxial PFA nebulizer (for self-priming), and a platinum interface cone were used as the sample introduction system. The measurement parameters for the cool plasma conditions are as follows: • RF (Radio Frequency) output (W): 600 Carrier gas flow rate (L / min): 0.7 Makeup gas flow rate (L / min): 1 • Sampling depth (mm): 18
[0157] [Phosphate ions] The phosphate ions were prepared either by using pre-purified components in each washing composition, or by adding phosphoric acid to each washing composition. In the above purification method, the substance to be purified was passed through an ion exchange resin membrane (IonClean SL DFA1SRPESW44, manufactured by Nippon Pall Co., Ltd.) until the desired content was reached. The phosphate ion content was measured using ion exchange chromatography (IC).
[0158] [Storage stability] <Changes in cleaning performance over time> Each of the cleaning compositions prepared above was placed in a glass container, sealed, and the resulting glass containers were stored at a temperature of 25°C for 30 days. Next, a wafer (8 inches in diameter) with a copper metal film on its surface was polished using a FREX300S-II polishing machine (manufactured by Ebara Corporation). For the wafer with the copper metal film on its surface, polishing was performed using CSL9044C (neutral (pH 6-8), silica slurry) and BSL8176C (alkaline, silica slurry) (product names, both manufactured by Fujifilm Planar Solutions Co., Ltd.) as polishing solutions. This reduced variability in the cleaning performance evaluation due to the polishing solutions. In each of the above CMP treatments, the polishing pressure was 2.0 psi, and the polishing solution supply rate was 0.28 mL / (min·cm). 2 The polishing time was 60 seconds. However, defects were observed after the CMP treatment described above. Subsequently, the polished wafers were washed for 30 seconds using each cleaning composition that had been stored for 30 days at 25°C, and then dried. Using a defect detection device (AMAT, ComPlus-II), the number of detected signal intensities corresponding to defects with a length of 0.1 μm or more on the polished surface of the obtained wafer was measured, and the defect count of 30d was calculated. For the above defect count of 30d, the defect count of 180d was calculated using the same procedure as for defect count of 30d, except that each cleaning composition was stored for 180 days. Then, based on the following formula, the rate of change in the number of defects over time was calculated to evaluate the change in cleaning performance over time. "Percentage change in the number of defects over time (%)" = ["Number of defects 180d" / "Number of defects 30d"] × 100 Furthermore, the closer the "rate of change in the number of defects over time" is to 100%, the better the results. 8. The "rate of change in the number of defects over time" is between 100% and 106%. 7: The "rate of change in the number of defects over time" is between 106% and 108%. 6. The "rate of change in the number of defects over time" is between 108% and 110%. 5: The "rate of change in the number of defects over time" is between 110% and 112%. 4: The "rate of change in the number of defects over time" is between 112% and 114%. 3: The "rate of change in the number of defects over time" is between 114% and 116%. 2: The "rate of change in the number of defects over time" is between 116% and 120%. 1: The "rate of change in the number of defects over time" is 120% or more.
[0159] <Changes in corrosion resistance (Cu) over time> Similar to the above [Changes in cleaning performance over time], each cleaning composition was prepared after being stored for 30 days or 180 days. A wafer (12 inches in diameter) with a copper metal film on its surface was cut to prepare a 2 cm square wafer coupon. The thickness of the copper film was 200 nm. The wafer coupon was immersed in samples of each cleaning composition (temperature: 23°C) prepared by the above method, and the immersion treatment was performed for 3 minutes at a stirring speed of 250 rpm. The copper content in each cleaning composition was measured before and after the immersion treatment. From the obtained measurement results, the corrosion rate (corrosion rate 30d, unit: Å / min) after storing each cleaning composition for 30 days and the corrosion rate (corrosion rate 180d, unit: Å / min) after storing each cleaning composition for 180 days were determined. Then, based on the following formula, the rate of change over time of the corrosion protection performance (Cu) was calculated, and the change over time of the corrosion protection performance (Cu) was evaluated. "Percentage change in corrosion rate over time (%)" = ["Corrosion rate 180d" / "Corrosion rate 30d"] × 100 The closer this value is to 100%, the better. 8. The "rate of change in corrosion rate over time" is between 100% and less than 106%. 7: The "rate of change in corrosion rate over time" is between 106% and 108%. 6: The "rate of change in corrosion rate over time" is between 108% and less than 110%. 5: The "rate of change in corrosion rate over time" is between 110% and 112%. 4: The "rate of change in corrosion rate over time" is between 112% and less than 114%. 3: The "rate of change in corrosion rate over time" is between 114% and 116%. 2: The "rate of change in corrosion rate over time" is between 116% and less than 120%. 1: "Corrosion rate over time" is 120% or more
[0160] [result] In the table, the "Content (mass %)" column shows the content (mass %) of each component relative to the total mass of the cleaning composition. In the "Type" column of "Specific Sulfonic Acids," entries such as "Sulfonic Acid A / Sulfonic Acid B / Sulfonic Acid C / Sulfonic Acid D (10 / 35 / 30 / 25)" indicate the content (mass %) of each specific sulfonic acid relative to the total content of all specific sulfonic acids. Specifically, in the case of "Sulfonic Acid A / Sulfonic Acid B / Sulfonic Acid C / Sulfonic Acid D (10 / 35 / 30 / 25)," it indicates that the total content of all specific sulfonic acids contains 10% by mass of sulfonic acid A, 35% by mass of sulfonic acid B, 30% by mass of sulfonic acid C, and 25% by mass of sulfonic acid D. The "A / B" column shows the mass ratio of the polycarboxylic acid content to the chelating agent content (polycarboxylic acid content / chelating agent content). The "A / C" column shows the mass ratio of the polycarboxylic acid content to the specific sulfonic acid content (polycarboxylic acid content / specific sulfonic acid content). The "B / C" column shows the mass ratio of the chelating agent content to the specific sulfonic acid content (chelating agent content / specific sulfonic acid content). The numerical value in the "pH" column indicates the pH at 25°C of the cleaning composition measured by the above pH meter. The "balance" of "water" means the remaining components (balance) that are not components explicitly shown as components of the cleaning composition in the table.
[0161]
Table 1
[0162]
Table 2
[0163]
Table 3
[0164]
Table 4
[0165] <000089x>
Table 5
[0166]
Table 6
[0167]
Table 7
[0168]
Table 8
[0169]
Table 9
[0170] It should be noted that there seems to be an error in the original text where <000089x> and <00009x> are used. They should probably be and respectively to be consistent with the consecutive numbering pattern. The translation has been done as accurately as possible based on the provided text.The cleaning composition of the present invention has been confirmed to have excellent storage stability. It was confirmed that the effects of the present invention are superior when the specific sulfonic acid includes alkylbenzenesulfonic acid A having a C10 alkyl group, alkylbenzenesulfonic acid B having a C11 alkyl group, alkylbenzenesulfonic acid C having a C12 alkyl group, and alkylbenzenesulfonic acid D having a C13 alkyl group (comparison of Examples 105 and 128-132, etc.). It was confirmed that the effects of the present invention are superior when the mass ratio of polycarboxylic acid to chelating agent is 30 to 100 (comparison of Examples 101 to 109, etc.). It was confirmed that the effects of the present invention are superior when the mass ratio of polycarboxylic acid to a specific sulfonic acid is 200 to 600 (70 to 600) (comparison of Examples 110 to 116, etc.).
[0171] [Examples 201-206] The storage stability of each cleaning composition described below was evaluated using a tungsten metal film instead of a copper metal film. The CMP treatment used to evaluate storage stability with the tungsten metal film was performed under conditions (e.g., polishing pressure, polishing fluid supply rate, and polishing time) that resulted in the detection of a similar number of defects after CMP treatment as with the copper metal film. W-2000 (manufactured by Cabot) was used as the polishing fluid. Furthermore, Example 201 was evaluated using the cleaning composition of Example 105, Example 202 using the cleaning composition of Example 117, Example 203 using the cleaning composition of Example 118, Example 204 using the cleaning composition of Example 119, Example 205 using the cleaning composition of Example 120, and Example 206 using the cleaning composition of Example 121.
[0172] [Examples 301-306] The storage stability of each cleaning composition described below was evaluated using an aluminum metal film instead of a copper metal film. The CMP treatment used to evaluate storage stability with the aluminum metal film was performed under conditions (e.g., polishing pressure, polishing fluid supply rate, and polishing time) that resulted in the detection of a similar number of defects after CMP treatment as with the copper metal film. HS-A (manufactured by Showa Denko Corporation) was used as the polishing fluid. In addition, Example 301 was evaluated using the cleaning composition of Example 105, Example 302 using the cleaning composition of Example 117, Example 303 using the cleaning composition of Example 118, Example 304 using the cleaning composition of Example 119, Example 305 using the cleaning composition of Example 120, and Example 306 using the cleaning composition of Example 121.
[0173] [Examples 401-406] The storage stability of each cleaning composition described below was evaluated using a cobalt metal film instead of a copper metal film. The CMP treatment used to evaluate storage stability with the cobalt metal film was performed under conditions (e.g., polishing pressure, polishing fluid supply rate, and polishing time) that resulted in the same number of defects after CMP treatment as with the copper metal film. MSL5100C (manufactured by Fujifilm Planar Solutions Co., Ltd.) was used as the polishing fluid. In addition, Example 401 was evaluated using the cleaning composition of Example 105, Example 402 using the cleaning composition of Example 117, Example 403 using the cleaning composition of Example 118, Example 404 using the cleaning composition of Example 119, Example 405 using the cleaning composition of Example 120, and Example 406 using the cleaning composition of Example 121.
[0174] [Examples 501-506] The storage stability of each cleaning composition described below was evaluated using a molybdenum metal film instead of a copper metal film. The CMP treatment used to evaluate storage stability with the molybdenum metal film was performed under conditions (e.g., polishing pressure, polishing fluid supply rate, and polishing time) that resulted in the detection of a similar number of defects after CMP treatment as with the copper metal film. W-2000 (manufactured by Cabot) was used as the polishing fluid. Note that Example 501 was evaluated using the cleaning composition of Example 105, Example 502 was evaluated using the cleaning composition of Example 117, Example 503 was evaluated using the cleaning composition of Example 118, Example 504 was evaluated using the cleaning composition of Example 119, Example 505 was evaluated using the cleaning composition of Example 120, and Example 506 was evaluated using the cleaning composition of Example 121.
[0175] [Examples 601 - 606] The storage stability of each of the cleaning compositions shown below was evaluated using a metal film made of ruthenium instead of a metal film made of copper. Note that the CMP process in the evaluation of the storage stability using a metal film made of ruthenium was carried out under conditions (e.g., polishing pressure, supply rate of the polishing liquid, polishing time, etc.) where the number of defects after the CMP process was equivalent to that of a metal film made of copper. W - 2000 (manufactured by Cabot Corporation) was used as the polishing liquid. Note that Example 601 was evaluated using the cleaning composition of Example 105, Example 602 was evaluated using the cleaning composition of Example 117, Example 603 was evaluated using the cleaning composition of Example 118, Example 604 was evaluated using the cleaning composition of Example 119, Example 605 was evaluated using the cleaning composition of Example 120, and Example 606 was evaluated using the cleaning composition of Example 121.
[0176] [Table 10]
[0177] [Table 11]
[0178] [Table 12]
[0179] [Table 13]
[0180] <000488>[Table 14]
[0181] It has been confirmed that the cleaning composition of the present invention can achieve the effects of the present invention even when cleaning objects other than copper.
[0182] When each of the cleaning compositions of the examples was used for the above-mentioned applications (cleaning of cleaning brushes, cleaning of polishing pads, cleaning of buffs, cleaning of semiconductor substrates that have undergone back grinding, cleaning of semiconductor substrates that have undergone etching, cleaning of flux residue on semiconductor substrates, cleaning of semiconductor substrates that have undergone bonding, cleaning of resin products, cleaning of glass substrates, and etching), it was confirmed that in all cases the cleaning composition performed better than the cleaning composition of the comparative example.< / ph>
Claims
1. It contains a polycarboxylic acid, a chelating agent, a sulfonic acid having an alkyl group with 9 to 18 carbon atoms, and water. The mass ratio of the polycarboxylic acid to the chelating agent is 10 to 200. The mass ratio of the polycarboxylic acid to the sulfonic acid is 70 to 1000. The pH is between 0.10 and 4.
00. A cleaning composition having an electrical conductivity of 0.08 to 11.00 mS / cm.
2. The cleaning composition according to claim 1, wherein the polycarboxylic acid comprises a polycarboxylic acid having two to three carboxyl groups.
3. The cleaning composition according to claim 1, wherein the polycarboxylic acid further comprises a polycarboxylic acid having a hydroxyl group.
4. The cleaning composition according to claim 1, wherein the polycarboxylic acid comprises citric acid.
5. The cleaning composition according to claim 1, wherein the content of the polycarboxylic acid is 0.1 to 35% by mass of the total mass of the cleaning composition.
6. The cleaning composition according to claim 1, wherein the sulfonic acid is alkylbenzenesulfonic acid.
7. The cleaning composition according to claim 1, wherein the sulfonic acid has any of the alkyl groups having 10 to 13 carbon atoms.
8. The cleaning composition according to claim 1, wherein the sulfonic acid comprises alkylbenzenesulfonic acid A having a C10 alkyl group, alkylbenzenesulfonic acid B having a C11 alkyl group, alkylbenzenesulfonic acid C having a C12 alkyl group, and alkylbenzenesulfonic acid D having a C13 alkyl group.
9. The cleaning composition according to claim 8, wherein the content of alkylbenzenesulfonic acid B is 20 to 50% by mass relative to the total mass of alkylbenzenesulfonic acids A to D.
10. The cleaning composition according to claim 1, wherein the chelating agent has a phosphonic acid group.
11. The cleaning composition according to claim 1, wherein the mass ratio of the polycarboxylic acid to the chelating agent is 30 to 100.
12. The cleaning composition according to claim 1, wherein the mass ratio of the polycarboxylic acid to the sulfonic acid is 70 to 600.
13. Furthermore, it contains phosphate ions, The cleaning composition according to claim 1, wherein the content of the phosphate ions is 0.001 to 1.0% by mass of the total mass of the cleaning composition.
14. The cleaning composition according to claim 1, wherein the pH is 0.10 to 1.
50.
15. A method for cleaning a semiconductor substrate, comprising cleaning the semiconductor substrate using the cleaning composition described in any one of claims 1 to 14.
16. A method for manufacturing a semiconductor device, comprising the method for cleaning a semiconductor substrate as described in claim 15.
Citation Information
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