Cleaning liquid, substrate cleaning method, and method for forming metal-containing film

Abstract

The present application relates to a cleaning liquid, a substrate cleaning method, and a method for forming a metal-containing film. The present application aims to provide a cleaning liquid, a substrate cleaning method using the aforementioned cleaning liquid, and a method for forming a metal-containing film using the aforementioned cleaning method, the cleaning liquid being excellent in cleaning properties such as removal of a metal-containing film on a peripheral portion of a substrate when a metal-containing film forming composition is applied to the substrate, and in stability of liquid discharge. The solution to the problem is a cleaning liquid, which is a cleaning liquid for a metal-containing film forming composition, and is characterized by containing: (A) an organic acid, (B) a compound having two or more β-diketone structures in a molecule, and (C) a solvent.

Description

Technical Field

[0001] This invention relates to a cleaning solution for forming a metal-containing film, a substrate cleaning method, and a method for forming a metal-containing film that can be used in microfabrication steps such as semiconductor devices. Background Technology

[0002] With the increasing integration and speed of LSI (Lithium-ion Sensor), the miniaturization of pattern sizes has progressed rapidly. Photolithography, in turn, has achieved the formation of fine patterns through the shortening of light source wavelengths and the appropriate selection of resist compositions. At its core is a single-layer positive photoresist composition. This single-layer positive photoresist composition has a framework in the resist resin that is etch-resistant to dry etching by chlorine-based or fluorine-based gas plasmas, and it possesses a switching mechanism that allows the exposed area to dissolve, thereby forming a pattern. The remaining resist pattern then serves as an etching mask for dry etching of the substrate.

[0003] However, when the thickness of the photoresist film is directly reduced, that is, the pattern width is further reduced, the resolution of the photoresist film decreases. Furthermore, if the photoresist film is to be developed using a developer, the aspect ratio will become too large, resulting in pattern degradation. Therefore, with the miniaturization of patterns, photoresist films have also become thinner.

[0004] On the other hand, the processing of substrates typically involves using a patterned photoresist film as an etching mask and then dry etching the substrate. However, in reality, there is no dry etching method that can achieve complete etch selectivity between the photoresist film and the substrate. Therefore, during substrate processing, the photoresist film may be damaged and break down, preventing the resist pattern from being correctly transferred to the substrate. To address this, as patterns become more refined, higher dry etching resistance is required for the resist composition. However, to improve resolution, the resin used in the photoresist composition must have low light absorption at the exposure wavelength. Therefore, as the exposure light wavelength has shortened to i-rays, KrF, and ArF, the resin has also changed to phenolic varnish resins, polyhydroxystyrene, and resins with aliphatic polycyclic skeletons. However, in reality, the etching rate under dry etching conditions during substrate processing increases, and the most recent photoresist compositions with high resolution tend to have weaker etching resistance.

[0005] Therefore, it is necessary to dry etch the substrate with a thinner photoresist film that has weaker etching resistance. Ensuring the quality of materials and processes for this step has become a top priority.

[0006] One method to solve this problem is the multilayer resist method. This method involves placing an intermediate resist film, whose etching selectivity differs from that of the photoresist film (i.e., the upper resist film), between the upper resist film and the substrate to be processed. After a pattern is obtained on the upper resist film, the pattern on the upper resist film is used as a dry etching mask, and the pattern is transferred to the intermediate resist film by dry etching. Then, the intermediate resist film is used as a dry etching mask, and the pattern is transferred to the substrate to be processed by dry etching.

[0007] One type of multilayer photoresist method is the three-layer photoresist method, which uses common photoresist compositions used in single-layer photoresist methods. In this three-layer photoresist method, for example, an organic film composed of phenolic resin or similar material is formed on the substrate as the lower photoresist layer, a silicon-containing photoresist intermediate film is formed on top of it as the middle photoresist layer, and a common organic photoresist film is formed on top of it as the upper photoresist layer. During dry etching using fluorine-based gas plasma, the organic photoresist upper layer achieves good etch selectivity for the silicon-containing photoresist intermediate film, thus the pattern of the upper photoresist layer can be transferred to the silicon-containing photoresist intermediate film by dry etching using fluorine-based gas plasma. This method allows for the transfer of patterns onto a silicon-containing resist intermediate film (resist intermediate film) even when using resist compositions that are difficult to form with a film thickness sufficient for direct processing of the substrate, or resist compositions that lack sufficient dry etching resistance for substrate processing. Subsequently, by performing dry etching using oxygen- or hydrogen-based gas plasma, a pattern of an organic film (resist underlayer film) made of phenolic varnish resin or similar materials with sufficient dry etching resistance for substrate processing can be obtained. Several types of resist underlayer films, such as those described in Patent Document 1, are already known.

[0008] On the other hand, in recent years, the miniaturization of DRAM memory has accelerated, increasing the need for resist underlayers with improved dry etching resistance, as well as excellent filling and planarization properties. Regarding coating-type organic underlayer materials with excellent filling and planarization properties, such as those described in Patent Document 2, there are concerns about their dry etching resistance when targeting next-generation applications, and they are approaching the application limits of known coating-type organic underlayer materials.

[0009] To address the aforementioned issues, researchers have explored the development of materials containing metal elements for use in resist underlayer films. Through baking, the metal ligands in the metal-containing film-forming composition undergo thermal decomposition, hydrolysis, and condensation to form metal oxides, resulting in resist underlayer films with excellent dry etching resistance. Patent document 3 reports that materials using Ti compounds exhibit excellent dry etching resistance to CHF3 / CF4 and CO2 / N2 gases.

[0010] When a metal-containing film-forming composition is used as the lower layer of the resist, metal compounds may bond to the surface of the substrate, such as a silicon wafer, during the coating of the metal-containing film-forming composition onto the substrate, potentially causing residue. To remove this residue, a cleaning solution containing an organic solvent and a carboxylic acid has been proposed (Patent Document 4). Furthermore, Patent Document 5 proposes a cleaning solution containing additives that function as solvents, organic acids, and chelating agents.

[0011] On the other hand, considering practicality, when the above-mentioned multilayer corrosion inhibitor method is carried out in one device, the effluent from multiple steps is usually discharged through the same piping, and the cleaning fluid is required to have effluent stability to suppress unexpected events such as metal precipitation in the piping caused by interference with other effluents.

[0012] Existing technical documents

[0013] Patent documents

[0014] [Patent Document 1] Japanese Patent Application Publication No. 2004-205685

[0015] [Patent Document 2] Japanese Patent Application Publication No. 2017-119671

[0016] [Patent Document 3] Japanese Patent Application Publication No. 2016-532739

[0017] [Patent Document 4] Japanese Patent Application Publication No. 2019-532489

[0018] [Patent Document 5] Japanese Patent Application Publication No. 2020-173361 Summary of the Invention

[0019] [The problem that the invention aims to solve]

[0020] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a cleaning solution, a cleaning method for a substrate using the cleaning solution, and a method for forming a metal-containing film using the cleaning method. The cleaning solution has excellent cleaning properties, such as removal of the metal-containing film on the periphery of the substrate, and excellent drainage stability when a metal-containing film forming composition is coated on the substrate.

[0021] [Methods for solving the problem]

[0022] To achieve the above objectives, the present invention provides a cleaning solution, which is a cleaning solution containing a metal-containing film-forming composition, characterized in that it contains:

[0023] (A) Organic acids,

[0024] (B) Compounds with two or more β-diketone structures within their molecules, and

[0025] (C) Solvent.

[0026] If it is this kind of cleaning solution, since compound (B) has more than two β-diketone structures in the molecule, in microscopic cases, it can exert a 2-coordinate chelating effect by having β-diketone structures as part of the structure, and in macroscopic cases, it can exert a stronger chelating effect of 4-coordinate or more by having multiple β-diketone structures, thus improving the metal removal performance of the cleaning solution.

[0027] Furthermore, it is preferable that the aforementioned compound (B) has a structure represented by the following general formula (B-1).

[0028] [Chemistry 1]

[0029]

[0030] (In the formula, R1 and R2 are hydrogen atoms, monovalent organic groups with 1 to 30 carbon atoms, thiols, hydroxyl groups, amino groups, carboxyl groups, or halogen atoms, X is an n-valent organic group with 1 to 60 carbon atoms, and n is an integer from 2 to 6.)

[0031] If the cleaning solution contains this (B) compound, the metal removal and drainage stability can be further improved.

[0032] Furthermore, it is preferable that the aforementioned compound (B) has a structure represented by the following general formula (B-0a).

[0033] [Chemistry 2]

[0034]

[0035] (In the formula, R1 and R2 are hydrogen atoms, monovalent organic groups with 1 to 30 carbon atoms, thiols, hydroxyl groups, amino groups, carboxyl groups, or halogen atoms, and Xa is preferably represented by the following general formula (B-1a).)

[0036] [Chemistry 3]

[0037]

[0038] (In the above formula, W is a divalent organic group) 1For the bonding portion with the oxygen atom, 2 (This is the bonding portion with the carbonyl carbon atom of the β-diketone.)

[0039] If the cleaning solution contains this (B) compound, the metal removal and drainage stability can be further improved.

[0040] Furthermore, it is preferable that Xa in the above general formula (B-0a) has the structure represented by the following general formula (B-2a).

[0041] [Chemistry 4]

[0042]

[0043] (In the formula, m1 represents the average number of repeating units, and represents 1 to 10.) (This indicates the bonding portion.)

[0044] If the cleaning solution contains this (B) compound, the metal removal and drainage stability can be further improved.

[0045] Furthermore, the solvent in (C) above preferably includes at least one solvent selected from the group consisting of ketone solvents and ester solvents.

[0046] Using this solvent can improve the long-term stability of the cleaning solution.

[0047] Furthermore, the organic acid (A) mentioned above should preferably be a carboxylic acid.

[0048] By including carboxylic acids as organic acids in the cleaning solution, the removal of metals can be further improved.

[0049] Furthermore, the content of the aforementioned compound (B) relative to the total mass of the aforementioned cleaning solution should preferably be 0.1 to 10% by mass.

[0050] By ensuring that the content of compound (B) in the cleaning solution is within the above-mentioned range, the metal removal properties, the long-term stability of the cleaning solution, and the drainage stability can be further improved.

[0051] Furthermore, the content of the aforementioned organic acid (A) relative to the total mass of the aforementioned cleaning solution should preferably be 0.5 to 80% by mass.

[0052] By ensuring that the content of organic acids in the cleaning solution is within the above-mentioned range, the metal removal properties, the long-term stability of the cleaning solution, and the stability of the drain solution can be further improved.

[0053] Furthermore, the present invention provides a method for cleaning a substrate, comprising the following steps: directly or indirectly coating the substrate with a metal-containing film-forming composition; and cleaning the substrate with the cleaning solution of the present invention.

[0054] If this is the cleaning method for the substrate, it can reduce the metal residue generated on the substrate when coating metal-containing film-forming components.

[0055] Furthermore, the present invention provides a method for forming a metal-containing film, comprising the following steps: using a composition containing a (M) metal compound and a (D) solvent as a composition for forming a metal-containing film; directly or indirectly coating a substrate with the composition for forming a metal-containing film; and cleaning the periphery of the substrate with the cleaning solution of the present invention.

[0056] If this is the method for forming a metal-containing film, then the metal residue generated on the substrate during the coating of the metal-containing film forming composition can be reduced, so it can be ideally used in the step of forming a metal-containing film using the metal-containing film forming composition.

[0057] [The effects of the invention]

[0058] As explained above, the cleaning solution of the present invention contains (A) an organic acid, (B) a compound having two or more β-diketone structures within its molecule, and (C) a solvent. Therefore, it provides a cleaning solution with excellent cleaning properties and drainage stability, such as the removal of metal-containing films on the periphery of the substrate when a metal-containing film-forming composition is coated onto the substrate. Furthermore, in cleaning methods for substrates using this cleaning solution and in methods for forming metal-containing films, a cleaning solution with excellent cleaning properties and drainage stability can be used, thus suppressing malfunctions such as device contamination and efficiently forming the desired resist underlayer film without reducing productivity. These are ideally suited for the manufacture of semiconductor devices, which are expected to undergo further miniaturization in the future. Attached Figure Description

[0059] Figure 1 A flowchart illustrating an example of removing the film at the outer peripheral end using the cleaning solution of the present invention to form a metal-containing film on a substrate.

[0060] Figure 2 A flowchart illustrating an example of peeling off a metal-containing film on a substrate using the cleaning solution of the present invention.

[0061] Figure 3 This is a flowchart illustrating an example of the method for forming a metal-containing film according to the present invention. Detailed Implementation

[0062] In the manufacturing process of semiconductor devices, one of the processes performed in the step of forming a metal-containing film pattern is edge bead removal (EBR), which involves supplying a solvent to a substrate on which a metal-containing film is formed, and removing unwanted film from the periphery of the coating film in a ring shape. This EBR process is performed by locally spraying cleaning fluid from a solvent nozzle onto the periphery of a rotating substrate.

[0063] In the EBR process of metal-containing films, a cleaning solution, a cleaning method for a semiconductor substrate using the cleaning solution, and a method for forming a metal-containing film using the cleaning method are required. The cleaning solution should have excellent metal cleaning properties, such as removing the metal-containing film on the periphery of the substrate when a metal-containing film forming composition is coated on the substrate, and excellent stability when mixed with other draining solutions.

[0064] In current technology, the removal of metal-containing membranes is achieved using cleaning solutions containing organic solvents and carboxylic acids, but there is room for improvement in metal removal performance.

[0065] Through repeated and in-depth investigations into the above-mentioned issues, the inventors discovered that a cleaning solution containing a compound having two or more β-diketone structures within the molecule of (B) can solve the above-mentioned issues, thus completing the present invention.

[0066] That is, the present invention is a cleaning solution, a cleaning solution containing a metal-containing film-forming composition, characterized in that it contains:

[0067] (A) Organic acids,

[0068] (B) Compounds with two or more β-diketone structures within their molecules, and

[0069] (C) Solvent.

[0070] The present invention will now be described in detail, but the present invention is not limited thereto.

[0071] Cleaning solution

[0072] The cleaning solution of the present invention is a cleaning solution for a metal-containing film-forming composition, and contains: (A) an organic acid, (B) a compound having two or more β-diketone structures within its molecule, and (C) a solvent. The cleaning solution of the present invention is used to clean a substrate coated with a metal-containing film-forming composition.

[0073] [(A) Organic acids]

[0074] The cleaning solution of the present invention contains (A) an organic acid. By adding an organic acid to the cleaning solution, the removeability of metal-containing films formed on a substrate is improved.

[0075] Examples of organic acids mentioned above include: carboxylic acids, sulfonic acids, sulfinic acids, organic isophosphoric acid, organic isophosphoric acid, phenols, enols, thiols, imides, oximes, sulfonamides, etc.

[0076] The aforementioned organic acids are preferably sulfonic acids or carboxylic acids, with carboxylic acids being more preferred. Specific examples of sulfonic acids include: methanesulfonic acid, ethanesulfonic acid, N-(2-acetamido)-2-aminoethanesulfonic acid, morpholine ethanesulfonic acid, methanemidylthiopropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, 2-hydroxy-3-morpholinepropanesulfonic acid, camphor sulfonic acid, 3-(cyclohexylamino)-2-hydroxypropane-1-sulfonic acid, 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid, benzenesulfonic acid, pyridine sulfonic acid, aminobenzenesulfonic acid, hydroxybenzenesulfonic acid, hydroxypyridine sulfonic acid, xylenesulfonic acid, pyridine ethanesulfonic acid, toluidine sulfonic acid, diaminobenzenesulfonic acid, hydrazine benzenesulfonic acid, aminophenol sulfonic acid, chlorobenzenesulfonic acid, aminodimethylbenzenesulfonic acid, and aminomethoxybenzenesulfonic acid. Acids, chloroaniline sulfonic acid, naphthalene sulfonic acid, sulfonyl isoquinoline, 3-cyclohexylaminopropanesulfonic acid, aminochlorotoluene sulfonic acid, aminonaphthalene sulfonic acid, aminochlorophenol sulfonic acid, diaminotrimethylbenzene sulfonic acid, aminonaphthol sulfonic acid, dichloroaniline sulfonic acid, hydrogen quinoline sulfonic acid, dimethylaminosulfonic acid, ethoxyquinoline sulfonic acid, trichlorobenzene sulfonic acid, iodobenzene sulfonic acid, phenylaminonaphthalene sulfonic acid, nonafluoro-1-butane sulfonic acid, hydroxymethoxybenzophenone sulfonic acid, fluorescent gallium reagent (Lumogallion), hydroxyiodoquinoline sulfonic acid, calcium magnesium indicator (Calmagite), naphthalene disulfonic acid, dimethylazosulfonate III, vinyl sulfonic acid, aminomethanesulfonic acid, hydroxyamine-O-sulfonic acid, aminoethanesulfonic acid, aminopropanesulfonic acid, chlorosulfonic acid, trifluoromethanesulfonic acid, etc.

[0077] The specific examples of the aforementioned carboxylic acids include: formic acid, acetic acid, propionic acid, butyric acid (butyric acid), isobutyric acid (isobutyric acid), valeric acid, hexanoic acid, 2-ethylhexanoic acid, cyclohexanecarboxylic acid, cyclohexylacetic acid, 1-adamantanecarboxylic acid, benzoic acid, phenylacetic acid, and other carboxylic acids composed of aliphatic saturated hydrocarbon groups and / or aromatic hydrocarbon groups and carboxyl groups; difluoroacetic acid, trifluoroacetic acid, pentafluoropropane acid, heptafluorobutyric acid, fluorophenylacetic acid, difluorobenzoic acid, and other monocarboxylic acids containing fluorine atoms; 10-hydroxydecanoic acid, 5-oxohexanoic acid, 3-methoxycyclohexanecarboxylic acid, camphor carboxylic acid, dinitrobenzoic acid, nitrophenylacetic acid, lactic acid, glycolic acid, glyceric acid, salicylic acid, anisic acid, gallic acid, furan carboxylic acid, and other monocarboxylic acids containing heteroatoms other than fluorine atoms in the part other than the carboxyl group; acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, 3-butenoic acid, angelic acid, and chamomile. Unsaturated monocarboxylic acids such as floric acid, 4-pentenoic acid, cinnamic acid, sorbic acid, propynic acid, and 2-butynic acid; oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, dodecanedicarboxylic acid, propanetricarboxylic acid, butanetetracarboxylic acid, cyclohexanehexacarboxylic acid, 1,4-naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, and 1,2,3,4-cyclobutanetetracarboxylic acid are composed of single bonds and aliphatic compounds. Polycarboxylic acids composed of saturated hydrocarbon groups and / or aromatic hydrocarbon groups and multiple carboxyl groups; partial esterifications of the above polycarboxylic acids; polycarboxylic acids containing fluorine atoms such as difluoromalonic acid, tetrafluorophthalic acid, and hexafluoroglutaric acid; polycarboxylic acids containing heteroatoms other than fluorine atoms in the part other than carboxyl groups such as tartaric acid, citric acid, malic acid, malonic acid, diethanolic acid, and iminodiacetic acid; and unsaturated polycarboxylic acids such as maleic acid, fumaric acid, and arbutinic acid.

[0078] From the viewpoint of cleanability and drainage stability, the aforementioned organic acid is preferably selected from at least one of the group consisting of formic acid, acetic acid, citric acid, oxalic acid, 2-ethylhexanoic acid, dodecanoic acid, ascorbic acid, tartaric acid, glucuronic acid, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, 3-butenoic acid, and methanesulfonic acid.

[0079] The lower limit of the proportion of organic acid in the total components of the cleaning solution is preferably 0.5% by mass, more preferably 1% by mass, even more preferably 2% by mass, and most preferably 3% by mass. The upper limit of the above proportion is preferably 80% by mass, more preferably 70% by mass, even more preferably 65% ​​by mass, and most preferably 60% by mass. By setting the proportion of organic acid within the above range, the cleaning performance and drainage stability can be further improved.

[0080] [(B) compound]

[0081] The cleaning solution of the present invention contains a compound (B) having two or more β-diketone structures within its molecule. Since the compound (B) has two or more β-diketone structures within its molecule, in microscopic cases, the β-diketone structures, which are part of the molecule, can exert a 2-coordinate chelating effect; in macroscopic cases, the presence of multiple β-diketone structures can exert a stronger chelating effect with 4 or more coordinates. Therefore, the metal removal performance and drainage stability of the cleaning solution can be improved.

[0082] The aforementioned compound (B) preferably has a structure represented by the following general formula (B-1).

[0083] [Chemistry 5]

[0084]

[0085] (In the formula, R1 and R2 are hydrogen atoms, monovalent organic groups with 1 to 30 carbon atoms, thiols, hydroxyl groups, amino groups, carboxyl groups, or halogen atoms, X is an n-valent organic group with 1 to 60 carbon atoms, and n is an integer from 2 to 6.)

[0086] Since this (B) compound functions as a chelating agent, it can improve the cleaning properties, such as the removal of metal-containing films on the periphery of the substrate when the metal-containing film-forming composition is coated onto the substrate.

[0087] In the above general formula (B-1), R1 is preferably a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted branched or cyclic alkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aliphatic unsaturated organic group having 2 to 30 carbon atoms containing one or more double or triple bonds, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 30 carbon atoms, an substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a thiol group, a hydroxyl group, an amino group, a carboxyl group, or a halogen atom. From the viewpoints of raw material availability, metal removal, and wastewater stability, it is preferably methyl or a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, and even more preferably methyl or a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms. Specifically, the following structures can be exemplified as alkoxy groups having 1 to 30 carbon atoms.

[0088] [Chemistry 6]

[0089]

[0090] [Chemistry 7]

[0091]

[0092] In the above general formula (B-1), R2 is preferably a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted branched or cyclic alkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aliphatic unsaturated organic group having 2 to 30 carbon atoms containing one or more double or triple bonds, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 30 carbon atoms, an substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a thiol group, a hydroxyl group, an amino group, a carboxyl group, or a halogen atom. Specifically, the following structures can be exemplified, but from the viewpoint of raw material availability, metal removal and waste liquid stability, hydrogen atoms, substituted or unsubstituted saturated alkyl groups having 1 to 10 carbon atoms, and substituted or unsubstituted heteroalkyl groups having 1 to 10 carbon atoms are preferred.

[0093] [Chemistry 8]

[0094]

[0095] [Chemistry 9]

[0096]

[0097] In the above general formula (B-1), X is an n-valent organic group having 1 to 60 carbon atoms, including: a linear alkyl group having 1 to 30 carbon atoms (substituted or unsubstituted); a branched or cyclic alkyl group having 3 to 30 carbon atoms (substituted or unsubstituted); an aliphatic unsaturated organic group having 2 to 30 carbon atoms (substituted or unsubstituted) containing one or more double or triple bonds; a ketone group having 1 to 30 carbon atoms (substituted or unsubstituted); an ether group having 1 to 30 carbon atoms (substituted or unsubstituted); and so on. The preferred groups are substituted or unsubstituted ester groups with 1 to 30 carbon atoms, substituted or unsubstituted amide groups with 1 to 30 carbon atoms, substituted or unsubstituted imino groups with 1 to 30 carbon atoms, substituted or unsubstituted aryl groups with 6 to 30 carbon atoms, substituted or unsubstituted arylalkyl groups with 6 to 30 carbon atoms, or substituted or unsubstituted triazine rings, or substituted or unsubstituted saturated or unsaturated hydrocarbon groups with 2 to 30 carbon atoms forming a cyclic structure together with 2×n-valent aromatic rings. n is an integer from 2 to 6; considering the availability of raw materials and metal removal, 2 to 4 is preferred; considering the stability of the drain solution, 2 is more desirable.

[0098] Specific examples of the above general formula (B-1) can be listed below, but are not limited to these.

[0099] [Chemistry 10]

[0100]

[0101] (In the above formula, Z is any one of the following: a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; a substituted or unsubstituted branched or cyclic alkyl group having 3 to 30 carbon atoms; or a substituted or unsubstituted aliphatic unsaturated organic group having 2 to 30 carbon atoms containing one or more double or triple bonds. In the above formula, R1 and R2 are the same as described above.)

[0102] [Chemistry 11]

[0103]

[0104] (In the above formula, Z is any one of the following: a substituted or unsubstituted alkyl group with 1 to 30 carbon atoms; a substituted or unsubstituted branched or cyclic alkyl group with 3 to 30 carbon atoms; or a substituted or unsubstituted aliphatic unsaturated organic group with 2 to 30 carbon atoms containing one or more double or triple bonds; R) a (It can be any one of the following formulas.)

[0105] [Chemistry 12]

[0106]

[0107] (In the above formula, the dashed lines represent atomic bonds with the S atom. R1 and R2 are the same as above.)

[0108] [Chemistry 13]

[0109]

[0110] A preferred structure of the above general formula (B-1) can be represented by the structure shown in the following formula (B-0a).

[0111] [Chemistry 14]

[0112]

[0113] (In the formula, R1 and R2 are hydrogen atoms, monovalent organic groups with 1 to 30 carbon atoms, thiols, hydroxyl groups, amino groups, carboxyl groups, or halogen atoms, and Xa is the structure represented by the following general formula (B-1a).)

[0114] [Chemistry 15]

[0115]

[0116] (In the formula, W is a divalent organic group) 1 For the bonding portion with the oxygen atom, 2 (This refers to the bonding portion with the carbonyl carbon atom in a β-diketone structure.)

[0117] If the cleaning solution contains this compound, it can provide a cleaning solution with excellent metal cleaning properties, such as removing the metal-containing film on the periphery of the substrate when the metal-containing film-forming composition is coated on the substrate, and excellent stability when mixed with other draining solutions.

[0118] In the above general formula (B-1a), W is preferably any one of the following: a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; a substituted or unsubstituted branched or cyclic alkyl group having 3 to 30 carbon atoms; a substituted or unsubstituted aliphatic unsaturated organic group having 2 to 30 carbon atoms containing one or more double or triple bonds; a substituted or unsubstituted heteroalkyl group having 1 to 30 carbon atoms; or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. From the viewpoint of obtaining raw materials, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms or a substituted or unsubstituted heteroalkyl group having 1 to 30 carbon atoms is preferred.

[0119] Furthermore, considering the metal removal properties and drainage stability, it is preferable that Xa in the above general formula (B-0a) is represented by the structure shown in the following general formula (B-2a).

[0120] [Chemistry 16]

[0121]

[0122] (In the formula, m1 represents the average number of repeating units and is 1~10.) (This indicates the bonding portion.)

[0123] If the compound has this structure, the metal cleaning properties, such as the removal of metal-containing membranes, and the stability when mixed with other drains are further improved.

[0124] The content of the aforementioned compound (B) relative to the total mass of the aforementioned cleaning solution should preferably be 0.1 to 10% by mass.

[0125] [(C) Solvent]

[0126] The solvent (C) contained in the cleaning solution of the present invention is not particularly limited, but water, organic solvents, etc. can be listed.

[0127] The above-mentioned organic solvents include: propylene glycol methyl ether (PGME), propylene glycol ethyl ether (PGEE), propylene glycol propyl ether (PGPE), propylene glycol butyl ether (PGBE), propylene glycol methyl ethyl acetate (PGMEA), ethylene glycol methyl ether, and other glycol ethers and their esters; alcohols such as ethanol, propanol, isopropanol, isobutanol, hexanol, ethylene glycol, and propylene glycol; cyclic esters such as γ-butyrolactone; esters such as n-butyl acetate and ethyl acetate; ketones such as 2-heptanone, cyclopentanone, and cyclohexanone; liquid cyclic carbonates such as propylene carbonate and butylene carbonate; and cyclic sulfones such as sulfolane.

[0128] The solvent is preferably a glycol ether or an ester or ketone of glycol ethers, and preferably propylene glycol methyl ether (PGME), propylene glycol ethyl ether (PGEE), propylene glycol monopropyl ether (PGPE), propylene glycol methyl ethyl acetate (PGMEA), 2-heptanone, cyclopentanone, or cyclohexanone. Organic solvents without hydroxyl groups are even more preferred, and more preferably include at least one solvent selected from the group consisting of ketone solvents and ester solvents. Specifically, esters of glycol ethers or straight-chain ketones are preferred, and preferably propylene glycol methyl ethyl acetate (PGMEA) or 2-heptanone.

[0129] By using organic solvents that do not contain hydroxyl groups, the esterification reaction of organic acids contained in the cleaning solution during storage can be inhibited.

[0130] In this embodiment, the solvent can be used alone or in the form of a mixture of two or more solvents. In the cleaning solution of this embodiment, the lower limit of the solvent content relative to the total mass of the cleaning solution is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more. The upper limit of the solvent content relative to the total mass of the cleaning solution is preferably 99% by mass or less, more preferably 98% by mass or less, and even more preferably 95% by mass or less.

[0131] [Other ingredients]

[0132] The cleaning solution of this embodiment may contain other components in addition to those mentioned above, in accordance with the purpose of this invention. Other components may include: inorganic hydrofluoric acid, tetraalkylammonium compounds, surfactants, etc. Examples of inorganic hydrofluoric acid include: hexafluorosilicic acid, hexafluorophosphate, fluoroboric acid, etc. Examples of tetraalkylammonium compounds include: tetramethylammonium fluoride, tetrabutylammonium fluoride, tetrabutylammonium fluorosilicate, etc. Surfactants may, for example, be those described in paragraphs

[0142] to

[0147] of Japanese Patent Application Publication No. 2009-269953. Each additive may be used individually or in combination of two or more. In the cleaning solution of this embodiment, the content of additives (other components) relative to the total mass of the cleaning solution is preferably 0 to 10% by mass.

[0133] <Preparation method of cleaning solution>

[0134] The cleaning solution of the present invention can be prepared by mixing (A) an organic acid, (B) a compound having two or more β-diketone structures within its molecule, (C) a solvent, and any other organic acid or component as needed, in a predetermined proportion, and then filtering the resulting mixture through a filter with a pore size of 0.5 μm or less. Considering the removal of foreign matter and the presence of metallic impurities in the raw materials of the cleaning solution, a small pore size of the filter is preferable. The pore size of the filter is preferably 0.1 μm or less, and more preferably 0.05 μm or less. The filter substrate used in this case, i.e., the material constituting the filter, should preferably be a material that does not leach metals. Examples of such materials include nylon, polyethylene, polypropylene, polystyrene, and fluoropolymers. These substrates can be used individually, combined, or formed into a so-called polymer alloy structure by homogenizing the substrates together.

[0135] <Substrate Cleaning Method>

[0136] The cleaning solution of the present invention can be used for removing metal-containing film-forming components from the periphery of a substrate when coating a metal-containing film-forming composition onto the substrate.

[0137] The substrate cleaning method of the present invention includes the following steps: directly or indirectly coating the substrate with a metal-containing film forming composition; and cleaning the substrate with the cleaning solution described above.

[0138] When the metal-containing film forming composition is a material for a photoresist underlayer film, the following steps are also preferred: after the above cleaning step, directly or indirectly forming a photoresist film (photoresist pattern forming step) on the metal-containing film formed by the above coating step; exposing the aforementioned photoresist film; forming a photoresist pattern by development; and directly or indirectly transferring the photoresist pattern to the metal-containing film by etching with the aforementioned photoresist pattern as a mask.

[0139] When the metal-containing film forming component is a material for photoresist film, the following steps are preferable: exposing the aforementioned photoresist film; forming a photoresist pattern by development; and directly or indirectly transferring the photoresist pattern to the substrate by etching with the aforementioned photoresist pattern as a mask.

[0140] The peripheral portion of the aforementioned substrate refers to, for example, the outer peripheral portion of the substrate within 3.0 cm of its center from the outer peripheral end. This length from the outer peripheral end of the substrate to its center can be 2.0 cm, 1.0 cm, 0.5 cm, or 0.2 cm.

[0141] When the metal-containing film forming component is a material used for a photoresist underlayer film, the semiconductor substrate manufacturing method may, as needed, include the following step before the photoresist pattern forming step: directly or indirectly forming an organic photoresist underlayer film on a substrate having the metal-containing film formed by the above coating step (organic photoresist underlayer film forming step).

[0142] When the metal-containing film forming component is a material used for the lower layer of the resist film, the semiconductor substrate manufacturing method may, as needed, include the following step before the resist patterning step: directly or indirectly forming a silicon-containing film on the substrate having the metal-containing film formed by the above coating step (silicon-containing film forming step).

[0143] The following describes each step of the metal-containing film formation composition and cleaning solution used in the above-described semiconductor substrate manufacturing method, as well as the organic lower layer film formation step and the silicon-containing film formation step, which include any step.

[0144] <Metal-containing film-forming components>

[0145] The metal-containing film-forming composition of the cleaning solution applicable to the present invention is not particularly limited as long as it contains (M) a metal compound and (D) a solvent. The aforementioned metal-containing film-forming composition may contain any other arbitrary components depending on the purpose. The aforementioned metal-containing film-forming composition is preferably made from materials that can be used as photoresist films or photoresist underlayers.

[0146] The aforementioned (M) metal compound is preferably a compound containing metal atoms and oxygen atoms. Examples of metal atoms constituting the aforementioned (M) metal compound include, for example, metal atoms from Groups 3 to 16 of the periodic table (excluding silicon atoms). The aforementioned (M) metal compound may have one or more types of metal atoms.

[0147] Examples of metal atoms constituting the above (M) metal compounds include:

[0148] Group 3 metal atoms include scandium, yttrium, lanthanum, and cerium.

[0149] The metal atoms in Group 4 include titanium, zirconium, and hafnium.

[0150] Group 5 metal atoms include vanadium, niobium, tantalum, etc.

[0151] The metal atoms in Group 6 include chromium, molybdenum, and tungsten.

[0152] The metal atoms in Group 7 include manganese, rhenium, etc.

[0153] The metal atoms in Group 8 include iron, ruthenium, and osmium.

[0154] Group 9 metal atoms include cobalt, rhodium, and iridium.

[0155] Group 10 metals include nickel, palladium, and platinum.

[0156] Group 11 metal atoms include copper, silver, and gold.

[0157] Group 12 metal atoms include zinc, cadmium, and mercury.

[0158] The metal atoms in Group 13 include aluminum, gallium, and indium.

[0159] Group 14 metal atoms include germanium, tin, lead, etc.

[0160] Group 15 metal atoms include antimony, bismuth, etc.

[0161] The metal atoms in Group 16 are, for example, tellurium.

[0162] The metal atoms constituting the above-mentioned compound (M) are preferably metal atoms from Groups 3 to 16, more preferably metal atoms from Groups 4 to 14, even more preferably metal atoms from Groups 4, 5, and 14, and especially preferably metal atoms from Group 4. Specifically, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, molybdenum, indium, tin, hafnium, tantalum, tungsten, and bismuth, or combinations thereof, are preferred.

[0163] The components other than the metal atoms constituting the aforementioned (M) metal compound (hereinafter also referred to as "[X] compound") preferably contain one or more hydrolyzable groups, or are derived from ligands of compounds including organic acids (hereinafter also referred to as "(a) organic acids"), hydroxy acid esters, β-diketones, β-diketone esters, amines, amides, alkenes, hydrocarbons containing π bonds, and diphosphine. Here, "organic acid" refers to an acidic organic compound, and "organic compound" refers to a compound having at least one carbon atom. The contained form of (a) organic acid also includes organic acid anions formed by removing hydrogen ions from (a) organic acid.

[0164] Examples of hydrolyzable groups include halogen atoms, alkoxy groups, and acyloxy groups.

[0165] Examples of halogen atoms mentioned above include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0166] The alkoxy group mentioned above is preferably an alkoxy group with 1 to 10 carbon atoms, such as methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, octoxy, etc.

[0167] Examples of the aforementioned acyloxy groups include: acetoxy, ethyleneoxy, propionyloxy, butyryloxy, tert-butyryloxy, tert-valeryloxy, n-hexanecarbonyloxy, n-octanecarbonyloxy, etc.

[0168] The hydrolyzable groups mentioned above are preferably alkoxy and acyloxy groups, with propoxy, isopropoxy, butoxy, and octoxy groups being more preferred.

[0169] (a) Examples of organic acids include: carboxylic acids, sulfonic acids, sulfinic acids, organic isophosphoric acid, organic isophosphoric acid, phenols, enols, thiols, imides, oximes, sulfonamides, etc.

[0170] Examples of the aforementioned carboxylic acids include: formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, 2-ethylhexanoic acid, oleic acid, acrylic acid, methacrylic acid, trans-2,3-dimethylacrylic acid, stearic acid, linolenic acid, hypolinolenic acid, arachidonic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, gallic acid, shikimic acid, etc.; monocarboxylic acids include: oxalic acid, malonic acid, maleic acid, methylmalonic acid, fumaric acid, adipic acid, sebacic acid, phthalic acid, tartaric acid, etc.; and carboxylic acids with three or more carboxyl groups, such as citric acid, etc.

[0171] Examples of sulfonic acids mentioned above include benzenesulfonic acid and p-toluenesulfonic acid.

[0172] Examples of sulfinic acids mentioned above include benzenesulfinic acid and p-toluenesulfinic acid.

[0173] Examples of organic isophosphoric acids mentioned above include: diethyl isophosphoric acid, methylphenyl isophosphoric acid, diphenyl isophosphoric acid, etc.

[0174] Examples of organic isophosphorous compounds include: methyl isophosphorous acid, ethyl isophosphorous acid, tert-butyl isophosphorous acid, cyclohexyl isophosphorous acid, phenyl isophosphorous acid, etc.

[0175] Examples of phenols mentioned above include: monovalent phenols such as phenol, cresol, 2,6-xylenol, and naphthol; divalent phenols such as catechol, resorcinol, hydroquinone, and 1,2-naphthodiol; and trivalent or higher phenols such as pyrogallol and 2,3,6-naphthotriol.

[0176] Examples of enols mentioned above include 2-hydroxy-3-methyl-2-butene and 3-hydroxy-4-methyl-3-hexene.

[0177] Examples of thiols mentioned above include mercaptoethanol and mercaptopropanol.

[0178] Examples of the aforementioned imides include carboxylic acid imides such as maleimide and succinimide, as well as sulfonamides such as bis(trifluoromethanesulfonic acid)imide and bis(pentafluoroethanesulfonic acid)imide.

[0179] Examples of the aforementioned oximes include: benzaldehyde oxime, salicylaldehyde oxime, and other aldol oximes; and examples of ketone oximes include: diethyl ketone oxime, methyl ethyl ketone oxime, cyclohexanone oxime, and other ketone oximes.

[0180] Examples of sulfonamides mentioned above include: methylsulfonamide, ethylsulfonamide, benzenesulfonamide, toluenesulfonamide, etc.

[0181] The organic acid mentioned above (a) should preferably be a carboxylic acid with 1 to 10 carbon atoms.

[0182] Examples of hydroxy acid esters include glycolates, lactates, 2-hydroxycyclohexane-1-carboxylic acid esters, and salicylates.

[0183] Examples of the aforementioned β-diketones include: 2,4-pentanedione, 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, etc.

[0184] Examples of the aforementioned β-keto esters include: acetoacetate, α-alkyl-substituted acetoacetate, β-ketovalerate, benzoylacetate, 1,3-propanone dicarboxylate, etc.

[0185] Examples of amine compounds mentioned above include: pyridine, trimethylamine, piperidine, diethanolamine, triethanolamine, etc.

[0186] Examples of compounds containing the aforementioned amides include, for example, unsubstituted amides (NH2), methylamides (NHMe), dimethylamides (NMe2), diethylamides (NEt2), dipropylamides (NPr2), etc.

[0187] Compounds containing alkenes include, for example, chain alkenes such as ethylene and propylene, and cyclic alkenes such as cyclopentene, cyclohexene, and norcamphene.

[0188] Hydrocarbons with the aforementioned π bonds can be listed as follows: chain dienes such as butadiene and isoprene, cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene, norcampadiene and other cyclic dienes, benzene, toluene, xylene, hexamethylbenzene, naphthalene, indene and other aromatic hydrocarbons, etc.

[0189] Examples of the aforementioned diphosphines include: 1,1-bis(diphenylphosphyl)methane, 1,2-bis(diphenylphosphyl)ethane, 1,3-bis(diphenylphosphyl)propane, 2,2'-bis(diphenylphosphyl)-1,1'-binaphthyl, 1,1'-bis(diphenylphosphyl)ferrocene, etc.

[0190] Examples of the aforementioned (M) metal compounds include compounds represented by the formula (M-1). By using such a metal compound (M-1), a stable (M) metal compound can be formed, which can improve dry etching resistance.

[0191] [Chemistry 17]

[0192]

[0193] (In the formula, M is any one of titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, molybdenum, indium, tin, hafnium, tantalum, tungsten, and bismuth. L is a monodentate or polydentate ligand with 1 to 30 carbon atoms, and X is selected from halogen atoms, alkoxy groups, carboxyl groups, acyl groups, and -NR groups.) a R b The hydrolyzable group in it. R a and R b Each is an independent hydrogen atom or a monovalent organic group with 1 to 20 carbon atoms. (a + c = 1 to 6, where a is an integer from 0 to 4, b is an integer from 0 to 2, and c is an integer from 0 to 6.)

[0194] The hydrolytic group X in formula (M-1) can be listed as, for example, a halogen atom, an alkoxy group, a carboxyl group, an acyloxy group, and -NR. a R b R a and R b It is preferable that each of the following is an independent hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0195] Examples of halogen atoms mentioned above include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0196] Examples of alkoxy groups mentioned above include: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy, etc.

[0197] Examples of the aforementioned carboxylic acid groups include: ligands derived from monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, 2-ethylhexanoic acid, oleic acid, acrylic acid, methacrylic acid, trans-2,3-dimethylacrylic acid, stearic acid, linolenic acid, alpha-linolenic acid, arachidonic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, gallic acid, and shikimic acid; ligands derived from dicarboxylic acids such as oxalic acid, malonic acid, maleic acid, methylmalonic acid, fumaric acid, adipic acid, sebacic acid, phthalic acid, and tartaric acid; and ligands derived from carboxylic acids such as citric acid that have three or more carboxyl groups.

[0198] Examples of the aforementioned acyloxy groups include: acetoxy, ethyleneoxy, propionyloxy, butyryloxy, tert-butyryloxy, tert-valeryloxy, n-hexanecarbonyloxy, n-octanecarbonyloxy, etc.

[0199] The above-NR a R b Examples include unsubstituted amino groups, methylamino groups, dimethylamino groups, diethylamino groups, dipropylamino groups, etc.

[0200] The hydrolyzable group X mentioned above is preferably an alkoxy group, with isopropoxy, n-butoxy, or tert-butoxy being more preferred.

[0201] (Monodentate ligand)

[0202] Examples of monodentate ligands mentioned above include hydroxyl ligands, amide ligands, amine ligands, and olefin ligands.

[0203] Examples of the aforementioned amide ligands include: unsubstituted amide ligands (NH2), methylamide ligands (NHMe), dimethylamide ligands (NMe2), diethylamide ligands (NEt2), dipropylamide ligands (NPr2), etc.

[0204] Examples of amine ligands mentioned above include pyridine, trimethylamine ligand, and piperidine ligand.

[0205] Examples of olefin ligands mentioned above include: chain olefins such as ethylene and propylene, and cyclic olefins such as cyclopentene, cyclohexene, and norcamphene.

[0206] (Multidentate ligand)

[0207] Examples of polydentate ligands mentioned above include: ligands derived from hydroxy acid esters, ligands derived from β-diketones, ligands derived from β-keto esters, hydrocarbons with π bonds, diphosphine, etc.

[0208] Examples of hydroxy acid esters include glycolates, lactates, 2-hydroxycyclohexane-1-carboxylic acid esters, and salicylates.

[0209] Examples of the aforementioned β-diketones include: acetoacetate, α-alkyl-substituted acetoacetate, β-ketovalerate, benzoylacetate, 1,3-propanone dicarboxylate, etc.

[0210] Examples of the aforementioned β-diketone esters include: malonate diesters, α-alkyl-substituted malonate diesters, α-cycloalkyl-substituted malonate diesters, α-aryl-substituted malonate diesters, etc.

[0211] Hydrocarbons with the aforementioned π bonds can be listed as follows: chain dienes such as butadiene and isoprene, cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene, norcampadiene and other cyclic dienes, benzene, toluene, xylene, hexamethylbenzene, naphthalene, indene and other aromatic hydrocarbons, etc.

[0212] Examples of the aforementioned diphosphines include: 1,1-bis(diphenylphosphyl)methane, 1,2-bis(diphenylphosphyl)ethane, 1,3-bis(diphenylphosphyl)propane, 2,2'-bis(diphenylphosphyl)-1,1'-binaphthyl, 1,1'-bis(diphenylphosphyl)ferrocene, etc.

[0213] The aforementioned monodentate and polydentate ligands may also contain crosslinking groups. The crosslinking groups preferably include any one of vinyl, allyl, allyloxy, ethynyl, propargyl, propargyl, epoxy, or oxetane. By using metal compounds containing such ligands, metal-containing films with excellent thermosetting properties can be formed.

[0214] Furthermore, the aforementioned (M) metal compound may, for example, be anion containing an oxyacid (phosphate ion, sulfate ion, chromate ion, tungstate ion (WO4)). 2- ), molybdate ions (MoO4) 2- Compounds of inorganic anions or mixtures thereof, such as polyacid anions formed by the condensation of multiple oxyacids, etc.

[0215] The aforementioned polyacids can be isopolyacid anions (Mm'On'). c- It can also be a heteropolyacid anion (X l 'Mm'On') c- In the above ionic formula, M represents a polyatomic atom, X represents a heteroatom, m' represents the composition ratio of the polyatomic atom, n' represents the composition ratio of the oxygen atom, and l' represents the composition ratio of the heteroatom. c is the valence of the ion. Examples of polyatomic M include Mo, W, Ti, and Nb. Examples of heteroatom X include Si, P, As, S, Fe, and Co. Furthermore, some may also contain Na. + H + Equal pairs of cations.

[0216] From the perspective of excellent heat resistance, it is preferable to contain anions of at least one of the inorganic acids, namely tungsten (W) and molybdenum (Mo).

[0217] Examples of polybasic acids containing at least one of tungsten (W) and molybdenum (Mo) include, for example, tungstate ions [W] which are polybasic acids. 10 O 32 ] 4- Molybdate ions [Mo6O] 19 ] 2- , is a phosphotungstic acid ion [PW 12 O 40 ] 3- [P2W] 18 O 62 ] 6- silicotungstic acid ions [SiW] 12 O 40 ] 4- phosphomolybdate ions [PMo] 12 O 40 ] 3- SiMo ions 12 O 40 ] 4- phosphotungstic molybdenum ion [PW]12- x Mo x O 40 ] 3- (x is an integer from 1 to 11), [P2W] 18-y Mo y O 62 ] 6- (y is an integer from 1 to 17), silicotungstic molybdenum ion [SiW] 12- x Mo x O 40 ] 4- (x is an integer from 1 to 11), etc. As for polybasic acids containing at least one of the above-mentioned tungsten (W) and molybdenum (Mo), from the viewpoint of heat resistance and the ease of obtaining raw materials, the above-mentioned ones are preferably heteropoly acids, and more preferably heteropoly acids that also contain phosphorus (P).

[0218] Furthermore, considering heat resistance, phosphotungstic molybdenum ion [PW] is even more preferable. 10 Mo2O 40 ] 3- [PW] 11 Mo1O 40 ] 3- phosphotungsten ion [PW] 12 O 40 ] 3- Any one of them.

[0219] The aforementioned (M) metal compound may be a hydrolysate of a metal compound containing a hydrolyzable group, a hydrolysis condensate of a metal compound containing a hydrolyzable group, or a combination thereof. Here, "hydrolysis condensation reaction" refers to a reaction in which the hydrolyzable group of the metal compound is hydrolyzed to form a hydroxyl group (-OH), and the two resulting hydroxyl groups (-OH) undergo dehydration condensation to form an ether bond (-O-).

[0220] Alternatively, compounds that enable the reaction to become monodentate or polydentate ligands in these compounds via ligand exchange reactions may be used, as well as compounds that enable the reaction to become monodentate or polydentate ligands in the hydrolysis-condensation reaction products of metal-containing compounds with hydrolyzable groups or hydrolysis-condensation reaction products of metal-containing compounds with hydrolyzable groups.

[0221] Specific examples of the above (M) metal compounds may be illustrated below, but are not limited to these.

[0222] Compounds containing titanium include: diisopropoxybis(2,4-pentanedione)titanium (IV), tetra-n-butoxytitanium (IV), tetra-n-propoxytitanium (IV), tetraisopropoxytitanium (IV), tri-n-butoxytitanium monostearate (IV), tetra(2-ethylhexyl) titanate, dihydroxybis(lactic acid)titanium (IV), butanol titanium (IV) oligomer, aminopropyltrimethoxytitanium (IV), triethoxymono(2,4-pentanedione)titanium (IV), tri-n-propoxymono(2,4-pentanedione)titanium (IV), triisopropoxymono(2,4-pentanedione)titanium, di-n-butoxybis(2,4-pentanedione)titanium (IV), etc.

[0223] Compounds containing chromium include: tri(2-ethylhexanoic acid)chromium(III), tri(2,4-pentanedione)chromium(III), bis(2,2,6,6-tetramethyl-3,5-heptanedione)chromium(II), tri(trifluoro-2,4-pentanedione)chromium(III), chromium pyridine-2-carboxylate(III), chromium chloride(III), chromium chloride(II), chromium cyclohexanecarboxylate(II), etc.

[0224] Compounds containing nickel include: nickel acetate (II), nickel chloride, nickel 2-ethylhexanoate (II), bis(2,4-pentanedione) nickel (II) hydrate, bis(hexafluoroacetylacetone) nickel (II), nickel 2-amino-5-methylbenzenesulfonate (II), nickel trifluoromethanesulfonate (II), bis(2,2,6,6-tetramethyl-3,5-heptadecanedione) nickel (II), nickel propionate (II), etc.

[0225] Compounds containing manganese include tris(2,2,6,6-tetramethyl-3,5-heptadecyl)manganese(III), etc.

[0226] Compounds containing iron include: tris(2,2,6,6-tetramethyl-3,5-heptanedione)ferric(III), ferric oxocyclohexanecarboxylate(II), ferric chloride, etc.

[0227] Compounds containing cobalt include: cobalt dichloro[bis(diphenylphosphine)ethane], cobalt(II) bromide, cobalt(II) acetate, tris(1,3-diphenyl-1,3-propanedione)cobalt(III), cyclopentylacetatecobalt(II), etc.

[0228] Compounds containing copper include: copper acetate (II), monobutyl copper phthalate (II), copper acetylacetonate (II), copper heptanoate (I), copper 2-ethylhexanoate (II), etc.

[0229] Compounds containing zinc include: zinc diisopropoxide, zinc acetate (II), zinc chloride (II), zinc 4-vinylbenzoate (II), etc.

[0230] Compounds containing zirconium include: dibutoxybis(ethyl acetoacetate)zirconium (IV), di-n-butoxybis(2,4-pentanedione)zirconium (IV), tetra-n-butoxyzirconium (IV), tetra-n-propoxyzirconium (IV), tetraisopropoxyzirconium (IV), aminopropyltriethoxyzirconium (IV), 2-(3,4-epoxycyclohexyl)ethyltrimethoxyzirconium (IV), γ-epoxypropoxypropyltrimethoxyzirconium (IV), 3-isocyanopropyltrimethoxyzirconium (IV), and triethoxymono(2,4-pentanedione)zirconium (IV). Zirconium tri-n-propoxy mono(2,4-pentanedione) (IV), Zirconium triisopropoxy mono(2,4-pentanedione) (IV), Zirconium tri(3-methacryloxypropyl)methoxyzirconium (IV), Zirconium acetate (IV), Zirconium acetate oxide (IV), Zirconium bis(2-ethylhexanoate) (II), Zirconium tetra(2-ethylhexanoate) (IV), Zirconium bis(2-ethylhexanoate) oxide (IV), Zirconium nitrate, Zirconium chloride (IV), Zirconium carboxyethyl acrylate (IV), etc.

[0231] Compounds containing molybdenum include: pentaethoxymolybdenum (V), hexaethoxymolybdenum (VI), isopropoxymolybdenum (V), molybdenum acetate (II) dimer, bis(acetylacetone)molybdenum oxide (IV), bis(2,2,6,6-tetramethyl-3,5-heptadecyl)molybdenum oxide (VI), 2-ethylhexanoate molybdenum, molybdenum chloride (V), molybdenum chloride (III), etc.

[0232] Compounds containing indium include: tris(1,3-diphenyl-1,3-propanedione)indium(III), indium ethylbutyrate(III), indium acetate(III), triisopropoxyindium(III), etc.

[0233] Compounds containing tin include: tin acetate (II), tin acetate (IV), tin acetylacetone (II), tin tert-butoxide (IV), tin tetra-n-butoxide, tin tetraisopropoxide, tin 4-fluorophenylacetate (II), tin 2-ethylhexanoate (II), etc.

[0234] Compounds containing hafnium include: diisopropoxybis(2,4-pentanedione)hafnium(IV), tetrabutoxyhafnium(IV), tetraisopropoxyhafnium(IV), tetraethoxyhafnium(IV), dichlorobis(cyclopentadienyl)hafnium(IV), hafnium chloride(IV), tetra(dimethylamido)hafnium(IV), tetra(ethylmethylamido)hafnium(IV), hafnium carboxyethyl acrylate, bis(cyclopentadienyl)hafnium(IV) dichloride, hafnium trifluoromethanesulfonate(IV) hydrate, hafnium carboxyethyl acrylate(IV), etc.

[0235] Compounds containing tantalum include: methoxytantalum (V), ethoxytantalum (V), tetrabutoxytantalum (IV), pentabutoxytantalum (V), pentaethoxytantalum (V), tantalum chloride (V), penta(dimethylamino)tantalum (V), tris(diethylamide)(tert-butylimide)-tantalum (V), bis(2-ethylhexanoic acid)tantalum (II), etc.

[0236] Compounds containing tungsten include: ethoxytungsten (VI), tetrabutoxytungsten (IV), pentabutoxytungsten (V), pentamethoxytungsten (V), hexabutoxytungsten (VI), hexaethoxytungsten (VI), dichlorobis(cyclopentadienyl)tungsten (IV), etc.

[0237] Compounds containing bismuth include: bismuth(III) n-butoxybismuth, tris(tert-pentoxy)bismuth (III), triethoxybismuth (III), tris(β-diketoacid)bismuth (III), bismuth neodecanoate (III), tris(2-naphthol)bismuth (III), bismuth fluoride (III), bismuth bromide (III), bismuth iodide (III), bismuth oxychloride (III), bismuth acetate (III), bismuth subsalicylate (III), bismuth 2-ethylhexanoate (III), bismuth trifluoromethanesulfonate (III), etc.

[0238] [(D)solvent]

[0239] There are no particular limitations on the (D) solvent that can be used in the metal-containing film-forming composition used in this invention, as long as it is a metal compound (M) mentioned above and other additives contained therein that can dissolve it.

[0240] Specific examples of the solvent mentioned above (D) may include organic solvents described in paragraphs

[0091] to

[0092] of Japanese Patent Application Publication No. 2007-199653. More specifically, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, 2-heptanone, or a mixture containing one or more of these are preferred.

[0241] Examples of other solvents that can be used include: butanediol monomethyl ether, ethylene glycol monomethyl ether, butanediol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, butanediol monopropyl ether, propylene glycol monopropyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, 1-butanol, 2-butanol, 2-methyl-1-propanol, 4-methyl-2-pentanol, etc. Ketones, tetrahydrofuran, toluene, hexane, ethyl acetate, cyclopentanone, cyclohexanone, γ-butyrolactone methylpentyl ketone, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipentyl ether, isopentyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol monotert-butyl ether acetate, methyl isobutyl ketone, cyclopentyl methyl ether, etc.

[0242] The amount of the above-mentioned (D) solvent, relative to 100 parts by mass of the (M) metal compound, is preferably in the range of 200 to 10,000 parts, and more preferably 250 to 5,000 parts.

[0243] <Other Additives>

[0244] Depending on the intended use of the aforementioned metal-containing film-forming composition, it may also contain at least one of (E) a crosslinking agent, (F) an acid generator, and (G) a surfactant.

[0245] The following describes the components that can be contained in metal-containing film-forming compositions other than the (M) metal compound and (D) solvent mentioned above.

[0246] [(E) Crosslinking agent]

[0247] When a metal-containing film-forming composition is used as the lower layer of a photoresist film, a crosslinking agent (E) may be added to improve curability and further suppress miscibility with the upper layer of the photoresist film. The crosslinking agent is not particularly limited, and various known crosslinking agents can be widely used. Examples include: melamine-based crosslinking agents, glycourea-based crosslinking agents, benzoguanidine-based crosslinking agents, urea-based crosslinking agents, β-hydroxyalkylamide-based crosslinking agents, isocyanurate-based crosslinking agents, aziridine-based crosslinking agents, oxazoline-based crosslinking agents, epoxy-based crosslinking agents, and phenol-based crosslinking agents. One type of the above-mentioned crosslinking agent (E) may be used alone, or two or more may be used in combination. The amount of the above-mentioned crosslinking agent (E) added relative to 100 parts of the above-mentioned metal compound (M) is preferably 5 to 50 parts, more preferably 10 to 40 parts. An amount of 5 parts or more will exhibit sufficient curability and suppress miscibility with the upper layer of the photoresist film. On the other hand, if the amount added is less than 50 parts, there is no concern that the ratio of (M) metal compounds in the composition will decrease, leading to a deterioration in dry etching resistance.

[0248] Specifically, examples of the aforementioned melamine-based crosslinking agents include: hexamethoxymethylated melamine, hexabutoxymethylated melamine, their alkoxy and / or hydroxyl-substituted derivatives, and their partially self-condensing polymers.

[0249] Specifically, examples of the aforementioned glycourea-based crosslinking agents include: tetramethoxymethylated glycourea, tetrabutoxymethylated glycourea, their alkoxy and / or hydroxyl-substituted derivatives, and their partially self-condensing polymers.

[0250] Specifically, examples of the aforementioned benzoguanidine crosslinking agents include: tetramethoxymethylated benzoguanidine, tetrabutoxymethylated benzoguanidine, their alkoxy and / or hydroxy substituted derivatives, and their partially self-condensing polymers.

[0251] Specifically, examples of the aforementioned urea-based crosslinking agents include: dimethoxymethylated dimethoxyethylene urea, its alkoxy and / or hydroxy substituted derivatives, and their partially self-condensing polymers.

[0252] Specifically, N,N,N',N'-tetra(2-hydroxyethyl)hexanoic acid amide can be exemplified by the aforementioned β-hydroxyalkylamide crosslinking agent.

[0253] The aforementioned isocyanurate-based crosslinking agents can be specifically exemplified by: tricyclooxypropyl isocyanurate and triallyl isocyanurate.

[0254] Specifically, examples of the aforementioned aziridine-based crosslinking agents include: 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane and 2,2-dihydroxymethylbutanol-tris[3-(1-aziridine)propionate].

[0255] Specifically, examples of the above-mentioned oxazoline crosslinking agents include: 2,2'-isopropylidene bis(4-benzyl-2-oxazoline), 2,2'-isopropylidene bis(4-phenyl-2-oxazoline), 2,2'-methylene bis(4,5-diphenyl-2-oxazoline), 2,2'-methylene bis(4-phenyl-2-oxazoline), 2,2'-methylene bis(4-tert-butyl-2-oxazoline), 2,2'-bis(2-oxazoline), 1,3-phenylidene bis(2-oxazoline), 1,4-phenylidene bis(2-oxazoline), and 2-isopropylidene oxazoline copolymers.

[0256] Specifically, examples of the aforementioned epoxy crosslinking agents include: diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,4-cyclohexanediethanol diglycidyl ether, poly(glycidyl methacrylate), trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, and neopentyl terephthalol tetraglycidyl ether.

[0257] Specifically, the phenolic crosslinking agents mentioned above can be exemplified by compounds represented by the following general formula (10).

[0258] [Chemistry 18]

[0259]

[0260] (In the formula, Q is a single bond, or q with 1 to 20 carbon atoms) 1 Valence hydrocarbon group. R 16 It consists of hydrogen atoms or alkyl groups having 1 to 20 carbon atoms. q 1 (Integers from 1 to 5.)

[0261] In the above general formula (10), Q is a single bond, or a q bond with 1 to 20 carbon atoms. 1 Valence hydrocarbon group. q 1 It is an integer from 1 to 5, with 2 or 3 being preferred. Specific examples of Q can be groups composed of methane, ethane, propane, butane, isobutane, pentane, cyclopentane, hexane, cyclohexane, methylpentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, benzene, toluene, xylene, ethylbenzene, ethylisopropylbenzene, diisopropylbenzene, methylnaphthalene, ethylnaphthalene, and eicosane. R 16 It is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Specific examples of alkyl groups having 1 to 20 carbon atoms include: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, octyl, ethylhexyl, decyl, eicosyl, preferably with a hydrogen atom or a methyl group.

[0262] Considering the need to improve curability and film thickness uniformity, the compounds represented by the above general formula (10) are preferably triphenol methane, triphenol ethane, 1,1,1-tris(4-hydroxyphenyl)ethane, or hexamethoxymethylated derivatives of tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene.

[0263] [(F) Acid generating agent]

[0264] The metal-containing film-forming composition of the present invention may include (F) an acid generating agent, such as a compound that generates acid in response to active light or radiation (photoacid generating agent). The aforementioned photoacid generating agent is any compound that generates acid by irradiation with high-energy rays. Ideal photoacid generating agents include sulfonium salts, sulfonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generating agents, etc. Furthermore, it may also contain a thermal acid generating agent that generates acid by heat. Specific examples of acid generating agents include, for example, those described in Japanese Patent Application Publication No. 2008-111103, paragraphs

[0122] to

[0142] , Japanese Patent Application Publication No. 2009-080474, and Japanese Patent Application Publication No. 2015-026064.

[0265] The acid generating agent described above (F) can be used alone or in combination of two or more. The amount of acid generating agent added relative to 100 parts by mass of the metal compound described above (M) is preferably 0.05 to 50 parts by mass, and more preferably 0.1 to 10 parts by mass.

[0266] [(G) surfactant]

[0267] In the composition for forming a metal-containing film, a surfactant (G) may be added to improve the coatability during spin coating. The surfactant may be, for example, the one described in paragraphs

[0142] to

[0147] of Japanese Patent Application Publication No. 2009-269953. The amount of surfactant (G) added is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, relative to 100 parts by weight of the aforementioned metal compound (M).

[0268] [Coating Steps]

[0269] In the coating step, the metal-containing film-forming composition is coated directly or indirectly onto the substrate. The coating method for the metal-containing film-forming composition is not particularly limited; for example, appropriate methods such as spin coating, casting coating, or roll coating can be used. A coating film is thus formed, and the metal-containing film is formed by the evaporation of solvent (D).

[0270] The substrate for coating the metal-containing film formation composition is not particularly limited, and substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, and Al can be used, as well as substrates on which a processing layer is formed. The processing layer can be various Low-k films and barrier films such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, and can typically be formed with a thickness of 50 to 10,000 nm, especially 100 to 5,000 nm. Furthermore, the substrate and the processing layer can be made of different materials when forming the processing layer.

[0271] The lower limit of the average thickness of the formed metal-containing film is preferably 3 nm, more preferably 5 nm, and even more preferably 10 nm. The upper limit of the above average thickness is preferably 500 nm, more preferably 200 nm, and even more preferably 60 nm. Furthermore, the method for measuring the average thickness is as described in the examples.

[0272] The method for manufacturing the substrate described above preferably includes a step of heating the coating film formed by the coating step described above (hereinafter also referred to as the "heating step"). Heating the coating film promotes the formation of a metal-containing film. More specifically, heating the coating film promotes the volatilization of solvent (D), etc.

[0273] The heating of the coating film described above is typically performed under atmospheric conditions, but can also be performed under a nitrogen atmosphere. The lower limit of the heating temperature is preferably 150°C, more preferably 200°C. The upper limit of the above temperature is preferably 600°C, more preferably 500°C. The lower limit of the heating time is preferably 15 seconds, more preferably 30 seconds. The upper limit of the above time is preferably 1,200 seconds, more preferably 600 seconds.

[0274] [Cleaning Steps]

[0275] In this step, the periphery of the substrate is cleaned with a cleaning solution. The cleaning solution described above can be used as the cleaning solution.

[0276] The cleaning method is not particularly limited, and well-known cleaning methods in semiconductor manufacturing processes, such as edge bead removal and back-side rinsing, can be used. In this invention, the step of cleaning the substrate on which the metal-containing film is formed preferably includes applying the cleaning solution of this invention along the periphery of the substrate to remove edge beads (hereinafter sometimes referred to as "edge rinsing") on the substrate.

[0277] Typically, first, a substrate with a metal-containing film formed is rotated at a predetermined speed. Next, while spraying cleaning fluid from a cleaning fluid spray nozzle, the nozzle moves at a predetermined speed from the outer periphery of the rotating substrate towards its center. The nozzle stops moving after traveling a predetermined distance, and then sprays cleaning fluid for a predetermined time. Afterward, the spraying of cleaning fluid from the nozzle stops, and the substrate is allowed to dry as needed, thereby completing the cleaning process. The substrate rotation speed, the amount of cleaning fluid sprayed per unit time, the moving speed and distance of the cleaning fluid spray nozzle, and the cleaning fluid spraying time after the nozzle stops moving can be appropriately set according to the substrate size, the number, type, and thickness of the film formed, and the cleaning area.

[0278] There is no particular limit to the number of edge rinses; they can be performed 1 to 20 times. Furthermore, two or more cleaning solutions can be used in edge rinsing.

[0279] During edge rinsing, the cleaning solution can be added dropwise in a volume of 0.05~50ml, more preferably 0.075~40ml, and even more preferably 0.1~30ml.

[0280] After the metal-containing film-forming composition is coated onto the substrate, the cleaning step can be performed with or without the aforementioned heating step. If the cleaning step is performed after the coating step without the aforementioned heating step, it is preferable to perform the aforementioned heating step after the cleaning step.

[0281] The metal-containing film formed by the above steps is preferably either a photoresist film or a photoresist underlayer film.

[0282] Furthermore, the cleaning solution of the present invention can also be used to rework metal-containing films on a substrate, thereby reusing the substrate. The cleaning solution nozzle is moved towards the center of the substrate, and the cleaning solution is sprayed onto the rotating substrate for a predetermined time. Afterward, the spraying of cleaning solution from the nozzle is stopped, and the substrate is allowed to dry as needed, thus completing the cleaning process. The substrate rotation speed, the amount of cleaning solution sprayed per unit time, and the spraying position of the cleaning solution can be appropriately set according to the substrate size, the number, type, and thickness of the film formed, and the cleaning area.

[0283] To evaluate the metal removal performance of edge washing, residual metal on the substrate can be examined. Commercially available methods for evaluating trace metals generally include inductively coupled plasma mass spectrometry (ICP-MS). For evaluating the substrate surface, vapor phase decomposition-inductively coupled plasma mass spectrometry (VPD-ICP-MS) can be used. Using this technique, the residual metal per unit area along the wafer surface at the edge can be determined.

[0284] In the substrate cleaning method of the present invention, when the metal-containing film is a Zr substrate, the amount of residual Zr is preferably 100 × 10⁻⁶. 10 atoms / cm 2 The following is preferred: 50×10 10 atoms / cm 2 The following is even better, 10×10 10 atoms / cm 2 The following is the optimal value: 5×10 10 atoms / cm 2 the following.

[0285] [Methods for forming metal-containing films]

[0286] The method for forming a metal-containing film of the present invention includes the following steps: using a composition containing a (M) metal compound and a (D) solvent as a composition for forming a metal-containing film, directly or indirectly coating the aforementioned composition for forming a metal-containing film onto a substrate; and cleaning the periphery of the aforementioned substrate using the cleaning solution described above.

[0287] Next, use Figures 1-3 The embodiments of the present invention are described below. However, the cleaning method of the present invention is not limited to these examples, and can also be implemented using methods other than these cleaning methods.

[0288] Firstly, regarding the first aspect of the present invention, while referring to... Figure 1 The method for removing the membrane at the outer peripheral end using the cleaning solution of the present invention is described below.

[0289] The first solution of the present invention ( Figure 1In step (A), a substrate (1) having a metal-containing film (2) formed thereon is placed in a coating machine. Next, (B) the coating machine is rotated at a predetermined speed, and the cleaning liquid (4) of the present invention is sprayed from a cleaning liquid spray nozzle (3) located near the outer peripheral end, while the film at the outer peripheral end is removed. Thereafter, it is dried as needed, thereby obtaining the metal-containing film (2A) shown in (C) with the film at the outer peripheral end removed.

[0290] Furthermore, regarding the second aspect of the present invention, while referring to... Figure 2 The method for peeling off a metal-containing film using the cleaning solution of the present invention is described below.

[0291] The second aspect of the present invention ( Figure 2 In step (D), the substrate (1) on which the metal-containing film (2) is formed is placed in a coating machine. Next, (E) the coating machine is rotated at a predetermined speed, the cleaning liquid spray nozzle (3) is moved toward the center of the substrate (1), and the cleaning liquid (4) is sprayed onto the rotating substrate (1) for a predetermined time. After that, the spraying of the cleaning liquid (4) from the cleaning liquid spray nozzle (3) is stopped, and the substrate is dried as needed, thereby obtaining the substrate (1a) shown in (F) with the metal-containing film peeled off.

[0292] Furthermore, regarding the third aspect of the present invention, while referring to... Figure 3 The method for forming a metal-containing film pattern according to the present invention will be described below.

[0293] The third aspect of the present invention ( Figure 3 In the process, (A) a substrate (1) having a metal-containing film (2) formed thereon is placed in a coating machine. Next, (B) the coating machine is rotated at a predetermined speed, and the cleaning solution (4) of the present invention is sprayed from a cleaning solution spray nozzle (3) located near the outer peripheral end, while the film at the outer peripheral end is removed. Thereafter, it is dried as needed, thereby (C) obtaining a metal-containing film (2A) with the film at the outer peripheral end removed. Next, (D) an organic photoresist lower layer film (7) is formed on the substrate, a silicon-containing photoresist intermediate film (6) is formed thereon as a photoresist intermediate film, and an organic photoresist film is formed thereon as a photoresist upper layer film (5). Thereafter, (E) exposure and development are performed to remove unwanted photoresist upper layer film (5b), and (F) a patterned photoresist upper layer film (5a) is obtained. Subsequently, (G) a patterned silicon-containing photoresist intermediate film (6a) is obtained by dry etching using fluorine-based gas plasma, and (H) a patterned organic photoresist lower film (7a) is obtained by dry etching using oxygen-based or hydrogen-based gas plasma, followed by (I) a patterned metal-containing film (2a).

[0294] Example

[0295] The present invention is illustrated below with synthetic examples, embodiments and comparative examples, but the present invention is not limited to these.

[0296] <(B) Compound>

[0297] [(B) compounds (b-1)~(b-4)]

[0298] The chelating agent (compound) used in the preparation of the cleaning solution is represented by the following formulas (b-1) to (b-4).

[0299] [Chemistry 19]

[0300]

[0301] [Synthetic Example 1] Synthesis of compound (b-1)

[0302] Under nitrogen atmosphere, 60.0 g of tert-butyl acetoacetate, 11.8 g of ethylene glycol, and 50 g of o-xylene were added. The tert-butanol generated via transesterification was removed from the system at an internal temperature of 140 °C. After reacting for 2 hours, the tert-butanol and o-xylene were removed from the system at an internal temperature of 160 °C while simultaneously increasing the temperature and reacting for 6 hours at 160 °C. 300 g of propylene glycol monomethyl ether acetate (PGMEA) was added to the residue and homogenized. Water and low-boiling-point solvents were distilled off, and the concentration was further adjusted to recover the compound (b-1) as a 50% PGMEA solution.

[0303] [Synthetic Example 2] Synthesis of compound (b-2)

[0304] The tert-butyl acetoacetate in Synthesis Example 1 was replaced with 71.5 g of tert-butyl ethyl malonate. Otherwise, it was recovered in the form of a 50% PGMEA solution of compound (b-2) using the same method as in Synthesis Example 1.

[0305] [Synthetic Example 3] Synthesis of compound (b-3)

[0306] In Synthesis Example 1, tert-butyl acetoacetate was replaced with 60.0 g of tert-butyl 2-butylacetoacetate, and ethylene glycol was replaced with 12.6 g of 1,4-butanediol. Otherwise, the compound was recovered in the form of a 50% PGMEA solution using the same method as in Synthesis Example 1.

[0307] [Synthetic Example 4] Synthesis of compound (b-4)

[0308] Under nitrogen atmosphere, 20.0 g of neopentyl ethoxylate tetrathioethanol, 27.0 g of allyl acetoacetate, and 200 g of THF (tetrahydrofuran) were added to prepare a homogeneous solution at an internal temperature of 50 °C. Subsequently, 1.1 g of 2,2'-azobis(isobutyric acid)dimethyl was added to prepare a homogeneous solution, and the reaction was carried out at an internal temperature of 60 °C for 24 hours. After the reaction was completed, the solution was cooled to room temperature, and 500 ml of hexane was added to the reaction solution to allow the reaction product to settle as a viscous liquid. After standing at room temperature for a short time, the separated supernatant layer was removed by decantation. 300 g of PGMEA (propylene glycol monomethyl ether acetate) was added to the residue and homogenized. Water and low-boiling-point solvents were distilled off, and the concentration was further adjusted to recover compound (b-4) as a 50% PGMEA solution.

[0309] The comparative examples used chelating agents (R-1) to (R-2) were the following compounds.

[0310] (R-1): Acetylacetone

[0311] (R-2): Dimethyl malonate

[0312] <Preparation of Cleaning Solution> (Examples 1-1~1-6, Comparative Examples 1-1~1-3)

[0313] Mix the components according to the proportions shown in Table 1 to prepare the cleaning solutions.

[0314] The solvent used is propylene glycol methyl ethyl acetate (PGMEA).

[0315] [Table 1]

[0316]

[0317] <Preparation of metal-containing film-forming compositions>

[0318] [Examples of metal compound synthesis]

[0319] In the following synthesis examples, the metal sources M: (M1)~(M3) and compound groups H: (H1)~(H3) are used.

[0320] (M1): Ti(OBu)4: Tetrabutyl titanate (Tokyo Chemical Industry Co., Ltd., B0742)

[0321] (M2): Hf(OBu)4: n-Butoxyhafnium(IV) (Sigma-Aldrich Corp, 667943)

[0322] (M3): Zr(OBu)4: Tetrabutoxyzirconium (IV) (80% by mass 1-butanol solution) (Tokyo Chemical Industry Co., Ltd., Z0016)

[0323] [Chemistry 20]

[0324]

[0325] [Synthetic Example 5] Synthesis of a metal compound (m-1) for metal-containing film formation

[0326] Under nitrogen atmosphere, while stirring, a solution of 28.4 g tetrabutyl titanate (M1) in 40.5 g of n-butanol was added dropwise to a solution of 1.6 g deionized water in 54.5 g of n-butanol over 2 hours at room temperature. 9.9 g of compound group (H1) was added to the resulting solution, and the mixture was stirred at room temperature for 30 minutes. This solution was concentrated under reduced pressure at 30°C, then further heated to 60°C and continued under reduced pressure until no more distillate was observed. When no distillate was visible, 69.0 g of a PGMEA / PGME (70 / 30 by weight) solution was added, and the mixture was heated at 40°C under reduced pressure until no more n-butanol was distilled off, yielding a PGMEA / PGME solution containing a metal compound (m-1) for film formation. The concentration of components other than the solvent in the aforementioned solution was 17% by mass.

[0327] [Synthesis of compounds (m-2) and (m-3)]

[0328] Using the above-mentioned metal source M and compound group H at the feed amounts shown in Table 2, compounds (m-2) and (m-3) shown in Table 2 were obtained under the same reaction conditions as in Synthesis Example 1.

[0329] [Table 2]

[0330]

[0331] Preparation of [Compound (m-4)]

[0332] The metal compound (m-4) is made using tin(II) 2-ethylhexanoate (Tokyo Chemical Industry Co., Ltd., T3149).

[0333] [Preparation of metal-containing film-forming composition (MUL-1)]

[0334] The metal-containing membrane-forming compound (m-1) was dissolved in a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) in the proportions shown in Table 3, and filtered through a 0.02 μm membrane filter to prepare the metal-containing membrane-forming composition (MUL-1).

[0335] [Preparation of metal-containing film-forming compositions (MUL-2~4)]

[0336] The types and contents of each component are shown in Table 3. Otherwise, the same procedures as for MUL-1 are followed to prepare each drug solution.

[0337] [Table 3]

[0338]

[0339] <Evaluation of Metal Cleanability>

[0340] On a 300 mm thick silicon substrate, the metal-containing film-forming compositions (MUL-1~4) prepared above were spin-coated to obtain a coated film. The average film thickness was measured using an Atlax-XP ellipsometry, and the result was 180 nm. 20 ml of cleaning solution (MER-1~6, Comparative Examples MER-1~3) was added to the obtained coated film, and the mixture was left to stand for 30 seconds. Then, it was spin-dried and baked at 100°C for 60 seconds to evaporate the cleaning solution. The obtained silicon substrate was cut into 2.0 cm × 3.5 cm pieces to obtain evaluation substrate A. Evaluation substrate A was immersed in a 38% hydrofluoric acid aqueous solution for 1 minute to obtain evaluation solution A, from which the metal components were extracted. Evaluation solution A was analyzed using a dual-focusing high-resolution ICP-MS ELEMENT2 manufactured by Thermo Fisher Scientific Inc.

[0341] Regarding the cleaning solution, OK73 Thinner was used to replace the cleaning solutions (MER-1~6, Comparative Examples MER1~3). Otherwise, the procedure for obtaining evaluation solution A was performed in the same manner to obtain evaluation solution B. OK73 Thinner is a mixed solvent of propylene glycol monomethyl ether and propylene glycol methyl ether acetate.

[0342] Metal cleaning performance was rated as "A" when the amount of metal constituting the metal compound used to form the metal-containing film, as detected by evaluation solution A, was less than 30% relative to evaluation solution B; "B" when it was 30% or more but less than 50%; and "C" when it was more than 50%. The results are shown in Table 4.

[0343] [Table 4]

[0344]

[0345] As shown in Table 4, in Examples 1-1 to 1-6 using the cleaning solution of the present invention, the amount of residual metal was low, which is a good result. It can be seen that since compounds having two or more β-diketone structures in their molecules are used as chelating agents, the metal cleaning performance is excellent. On the other hand, in Comparative Examples 1-1 to 1-3, the amount of residual metal was high, and the metal cleaning performance was poor.

[0346] <Drainage Stability> (Examples 2-1~2-6)

[0347] A mixed solution was prepared by mixing equal volumes of the cleaning solution (MER-1~6), the metal-containing film-forming composition (MUL-1~4), the photoresist underlayer film-forming composition (SOC-1), the silicon-containing film-forming composition (SOG-1), and the photoresist composition (PR-1). After standing at 23°C for one week, the presence of precipitates and turbidity was visually confirmed. The stability of the solution was rated as "good" if no precipitates or turbidity were observed after standing at 23°C for one week.

[0348] The following materials are used in the composition for forming the lower layer of photoresist (SOC-1), the composition for forming silicon-containing film (SOG-1), and the composition for photoresist (PR-1).

[0349] Regarding the composition for forming the underlayer resist (SOC-1), the polymer represented by the organic underlayer polymer (SOP1) was dissolved in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M) at the proportions shown in Table 5, and filtered through a fluoropolymer filter with a pore size of 0.2 μm, thereby preparing the composition for forming the underlayer resist (SOC-1).

[0350] [Table 5]

[0351]

[0352] The structural formula of the organic lower membrane polymer (SOP1) used in this evaluation is shown in Table 6.

[0353] [Table 6]

[0354]

[0355] Regarding the silicon-containing membrane forming composition (SOG-1), a polymer represented by a silicon-containing intermediate membrane polymer (SiP1) and a crosslinking catalyst (CAT1) were dissolved in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M) in the proportions shown in Table 7, and the mixture was filtered through a fluoropolymer filter with a pore size of 0.1 μm to prepare the silicon-containing membrane forming composition (SOG-1).

[0356] [Table 7]

[0357]

[0358] The structural formulas of the silicon-containing intermediate membrane polymer (SiP1) and crosslinking catalyst (CAT1) used in this evaluation are shown below.

[0359] [Chemistry 21]

[0360]

[0361] Regarding the photoresist composition (PR-1), the polymer, quencher, and sensitizer shown below were dissolved in an organic solvent containing 0.25% by mass of FC-4430 (manufactured by Sumitomo 3M) in the proportions shown in Table 8, and the solution was filtered through a fluoropolymer filter with a pore size of 0.1 μm to prepare the photoresist composition (PR-1).

[0362] [Chemistry 22]

[0363]

[0364] [Chemistry 23]

[0365]

[0366] Surfactant: 3M FC-4430

[0367] [Table 8]

[0368]

[0369] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0370] CyHO (Cyclohexanone)

[0371] PGME (Propylene Glycol Monomethyl Ether)

[0372] [Table 9]

[0373]

[0374] As shown in Table 9, the drainage stability is excellent in the examples (2-1 to 2-6) using the cleaning solution of the present invention.

[0375] As described above, the cleaning solution of the present invention, by containing compounds having two or more β-diketone structures within their molecules, provides a cleaning solution with excellent cleaning properties and drainage stability, such as removing metal-containing films from the periphery of a substrate when a metal-containing film-forming composition is coated onto the substrate. Furthermore, in cleaning methods for substrates using this cleaning solution and in methods for forming a resist underlayer, the use of a cleaning solution with excellent cleaning properties and drainage stability allows for the efficient formation of the desired resist underlayer. These are ideally suited for the manufacture of semiconductor devices, which are envisioned to be further miniaturized in the future.

[0376] This manual contains the following solutions.

[0377] [1]: A cleaning solution, which is a cleaning solution containing a metal-containing film-forming composition, and is characterized in that it contains:

[0378] (A) Organic acids,

[0379] (B) Compounds with two or more β-diketone structures within their molecules, and

[0380] (C) Solvent.

[0381] [2]: The cleaning solution as described in [1] above, wherein the aforementioned compound (B) has the structure represented by the following general formula (B-1).

[0382] [Chemistry 24]

[0383]

[0384] (In the formula, R1 and R2 are hydrogen atoms, monovalent organic groups with 1 to 30 carbon atoms, thiols, hydroxyl groups, amino groups, carboxyl groups, or halogen atoms, X is an n-valent organic group with 1 to 60 carbon atoms, and n is an integer from 2 to 6.)

[0385] [3]: The cleaning solution as described in [2] above, wherein the aforementioned compound (B) has the structure represented by the following general formula (B-0a).

[0386] [Chemistry 25]

[0387]

[0388] (In the formula, R1 and R2 are hydrogen atoms, monovalent organic groups with 1 to 30 carbon atoms, thiols, hydroxyl groups, amino groups, carboxyl groups, or halogen atoms, and Xa is the structure represented by the following general formula (B-1a).)

[0389] [Chemistry 26]

[0390]

[0391] (In the formula, W is a divalent organic group) 1 For the bonding portion with the oxygen atom, 2 (This refers to the bonding portion with the carbonyl carbon atom in the β-diketone structure.)

[0392] [4]: The cleaning solution as described in [3] above, wherein Xa in the aforementioned general formula (B-0a) is a structure represented by the following general formula (B-2a).

[0393] [Chemistry 27]

[0394]

[0395] (In the formula, m1 represents the average number of repeating units, and represents 1~10.) (This indicates the bonding portion.)

[0396] [5]: The cleaning solution of any one of [1] to [4] above, wherein the solvent of the above (C) comprises at least one solvent selected from the group consisting of ketone solvents and ester solvents.

[0397] [6]: The cleaning solution of any one of [1] to [5] above, wherein the organic acid of (A) above is a carboxylic acid.

[0398] [7]: The cleaning solution of any one of [1] to [6] above, wherein the content of the aforementioned (B) compound is 0.1 to 10 by mass relative to the total mass of the aforementioned cleaning solution.

[0399] [8]: The cleaning solution of any one of [1] to [7] above, wherein the content of the organic acid in (A) above is 0.5 to 80% by mass relative to the total mass of the cleaning solution above.

[0400] [9]: A method for cleaning a substrate, characterized by comprising the following steps: directly or indirectly coating a metal-containing film-forming composition onto the substrate; and cleaning the substrate with a cleaning solution as described in any one of [1] to [8] above.

[0401]

[10] : A method for forming a metal-containing film, characterized by comprising the following steps: using a composition containing a (M) metal compound and a (D) solvent as a composition for forming a metal-containing film, directly or indirectly coating the aforementioned composition for forming a metal-containing film onto a substrate; and cleaning the periphery of the aforementioned substrate using a cleaning solution of any one of [1] to [8] above.

[0402] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative examples, and those having a structure that is substantially the same as the technical concept described in the claims of the present invention and performing the same effect are all intended to be included within the technical scope of the present invention.

[0403] Explanation of reference numerals in the attached figures

[0404] 1: The substrate being processed

[0405] 1a: The substrate to be processed after the metal-containing film has been peeled off.

[0406] 2: Metal-containing membranes

[0407] 2A: Metal-containing membrane with the outer peripheral ends removed

[0408] 2a: Forming a patterned metallic film

[0409] 3: Nozzle for spraying cleaning fluid

[0410] 4: Cleaning solution

[0411] 5: Top layer of resist film

[0412] 5a: Formation of a patterned resist top film

[0413] 5b: The top layer of resist removed after exposure and development.

[0414] 6: Silicon-containing intermediate film

[0415] 6a: Forming a patterned silicon-containing intermediate film

[0416] 7: Organic resist underlayer film

[0417] 7a: Formation of a patterned organic resist underlayer film

Claims

1. A cleaning solution, comprising a metal-containing film-forming composition, characterized in that it contains: (A) Organic acids, (B) Compounds with two or more β-diketone structures within their molecules, and (C) Solvent.

2. The cleaning solution according to claim 1, wherein, The compound (B) has the structure represented by the following general formula (B-1); In the formula, R1 and R2 are hydrogen atoms, monovalent organic groups with 1 to 30 carbon atoms, thiols, hydroxyl groups, amino groups, carboxyl groups, or halogen atoms, X is an n-valent organic group with 1 to 60 carbon atoms, and n is an integer from 2 to 6.

3. The cleaning solution according to claim 2, wherein, The compound (B) has the structure represented by the following general formula (B-0a); In the formula, R1 and R2 are hydrogen atoms, monovalent organic groups with 1 to 30 carbon atoms, thiols, hydroxyl groups, amino groups, carboxyl groups, or halogen atoms, and Xa is the structure represented by the following general formula (B-1a). In the formula, W is a divalent organic group. 1 For the bonding portion with the oxygen atom, 2 This is the bonding portion with the carbonyl carbon atom of the β-diketone structure.

4. The cleaning solution according to claim 3, wherein, In this general formula (B-0a), Xa is the structure represented by the following general formula (B-2a); In the formula, m1 represents the average number of repeating units, and is 1 to 10; Indicates the bonding section.

5. The cleaning solution according to claim 1, wherein, The solvent (C) comprises at least one solvent selected from the group consisting of ketone solvents and ester solvents.

6. The cleaning solution according to claim 1, wherein, The organic acid (A) is a carboxylic acid.

7. The cleaning solution according to claim 1, wherein, The content of compound (B) is 0.1 to 10% of the total mass of the cleaning solution.

8. The cleaning solution according to claim 1, wherein, The content of the organic acid (A) relative to the total mass of the cleaning solution is 0.5 to 80% by mass.

9. A method for cleaning a substrate, characterized by comprising the following steps: directly or indirectly coating the substrate with a metal-containing film-forming composition; and cleaning the substrate with a cleaning solution according to any one of claims 1 to 8.

10. A method for forming a metal-containing film, characterized by comprising the following steps: using a composition containing a (M) metal compound and a (D) solvent as a composition for forming a metal-containing film, directly or indirectly coating the composition for forming a metal-containing film onto a substrate; and cleaning the periphery of the substrate using a cleaning solution according to any one of claims 1 to 8.

Images