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

Abstract

The invention relates to a cleaning solution, a method for cleaning a substrate, and a method for forming a metal-containing film. The present invention addresses the problem of providing a cleaning solution having excellent cleaning properties such as removal of a metal-containing film at the peripheral edge of a substrate after a metal-containing film-forming composition has been applied to the substrate, excellent bump suppression properties, and excellent liquid discharge stability. A method for cleaning a semiconductor substrate using the same; and a method for forming a metal-containing film using the cleaning method. The solution of the present invention is a cleaning solution for a metal-containing film-forming composition, the cleaning solution being characterized by containing (A) a solvent and (B) an organic acid, the solvent (A) contains at least one first solvent (A-1) having a standard boiling point of less than 160 DEG C and at least one second solvent (A-2) having a standard boiling point of 160 DEG C or more and less than 500 DEG C.

Description

Technical Field

[0001] The present invention relates to a cleaning liquid, a method for cleaning a substrate, and a method for forming a metal-containing film, and more particularly to a cleaning liquid containing a metal-containing film-forming composition that can be used in the micro-processing steps of semiconductor devices, a method for cleaning a semiconductor substrate, and a method for forming an anti-etching agent underlayer film. Background Art

[0002] With the increasing integration and speed of LSIs, pattern sizes are rapidly miniaturizing. Photolithography, along with this miniaturization, has achieved the formation of fine patterns through the shortening of light sources and the appropriate selection of resist compositions to match them. A central component of this process is single-layer positive photoresist compositions. These single-layer positive photoresist compositions feature a resist resin with a backbone that is resistant to dry etching using chlorine- or fluorine-based gas plasmas. Furthermore, they incorporate a switching mechanism that dissolves the exposed areas, forming a pattern. The remaining resist pattern then serves as an etching mask for dry etching of the substrate being processed.

[0003] However, when miniaturization is performed while maintaining the thickness of the photoresist film being used, that is, when the pattern width is reduced, the resolution of the photoresist film decreases. Furthermore, when the photoresist film is developed using a developer, the so-called aspect ratio becomes too large, resulting in pattern collapse. Therefore, as the pattern becomes miniaturized, the photoresist film thickness has been reduced.

[0004] Meanwhile, substrate processing typically involves dry etching using a patterned photoresist film as an etching mask. However, there is no dry etching method that achieves perfect etch selectivity between the photoresist film and the substrate being processed. Consequently, during substrate processing, the photoresist film can be damaged and broken, preventing the resist pattern from being properly transferred to the substrate. Consequently, with increasing pattern miniaturization, resist compositions are required to exhibit higher dry etching resistance. However, to improve resolution, the resins used in photoresist compositions must exhibit low light absorption at the exposure wavelength. Consequently, as exposure light wavelengths shorten to i-rays, KrF, and ArF, resins have evolved to include novolac resins, polyhydroxystyrene, and resins with aliphatic polycyclic backbones. However, the etching rate increases under dry etching conditions during substrate processing, and recent photoresist compositions with high resolution tend to exhibit reduced etching resistance.

[0005] Therefore, it has become necessary to use a thinner photoresist film with weaker etching resistance to dry-etch the substrate being processed, and ensuring the materials and processes in this processing step has become a top priority.

[0006] One solution to this problem is the multilayer resist method. This method involves placing a resist interlayer film with a different etching selectivity from the photoresist film (i.e., the resist upper layer) between the resist upper layer and the substrate being processed. After the resist upper layer acquires a pattern, the resist upper layer pattern is used as a dry etching mask to transfer the pattern to the resist interlayer film by dry etching. The pattern is then transferred to the substrate being processed by dry etching, using the resist interlayer film as a dry etching mask.

[0007] One type of multilayer resist method is the three-layer resist method, which can be performed using the same resist composition commonly used in single-layer resist methods. In this three-layer resist method, for example, an organic film made of a novolac resin or the like is formed on a substrate as a resist lower layer. A silicon-containing resist interlayer is formed thereon as a resist middle layer, and a conventional organic photoresist film is formed thereon as a resist upper layer. During dry etching using fluorine-based gas plasma, the organic resist upper layer exhibits good etching selectivity relative to the silicon-containing resist middle layer. Therefore, the resist upper layer pattern can be transferred to the silicon-containing resist middle layer by dry etching using fluorine-based gas plasma. This method allows, even when using a resist composition that is difficult to form a pattern having a sufficient film thickness for direct processing of a substrate to be processed, or a resist composition that lacks sufficient dry etching resistance for substrate processing, to transfer a pattern onto a silicon-containing resist interlayer film (resist interlayer film). Subsequently, by performing dry etching using oxygen- or hydrogen-based gas plasma to transfer the pattern, a pattern of an organic film (resist underlayer film) made of a novolac resin or the like having sufficient dry etching resistance for substrate processing can be obtained. Many resist underlayer films such as the one described in Patent Document 1 are already known.

[0008] Meanwhile, the recent acceleration of DRAM memory device miniaturization has led to a growing need for resist underlayer films with improved dry etching resistance, as well as excellent filling and planarization properties. While coating-type organic underlayer film materials with excellent filling and planarization properties have been reported, for example, as described in Patent Document 2, their dry etching resistance is questionable when targeting advanced-generation applications, approaching the limits of applicability of known coating-type organic underlayer film materials.

[0009] To address these challenges, research has been conducted on the development of materials containing metal elements for use in resist underlayer films. During a baking process, the metal ligands coordinated to the metal in the metal-containing film-forming composition undergo thermal decomposition, hydrolysis, and condensation to form metal oxides, enabling the formation of a resist underlayer film with excellent dry etching resistance. Patent Document 3 reports that materials using Ti compounds exhibit excellent dry etching resistance against CHF3 / CF4-based gases and CO2 / N2-based gases.

[0010] When a metal-containing film-forming composition is used in a resist underlayer film, there is a risk that the metal compound will bond to the surface of the substrate, such as a silicon wafer, when the metal-containing film-forming composition is applied to the substrate, resulting in 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 a solvent, an organic acid, and a chelating agent.

[0011] One of the processes performed during the step of forming a coating film pattern on a substrate, such as a semiconductor wafer, is edge bead removal (EBR), which involves applying a coating film-forming composition to the substrate surface by spin coating and then removing the unwanted film from the coating film's periphery in a circular pattern. In this EBR process, a solvent nozzle locally dispenses the coating film's solvent onto the periphery of the spin-coated wafer. During the EBR process, in order to ensure a circuit pattern formation area and improve semiconductor device yield, it is necessary to suppress the occurrence of humps near the boundaries of the film removal area, i.e., at the ends of the coating film (Patent Document 6). Similarly, when forming a metal-containing film using a metal-containing film-forming composition, in addition to ensuring cleanability during the removal of the metal-containing film from the substrate's periphery, suppressing humps is also a must.

[0012] On the other hand, considering practicality, since discharge liquids from multiple steps are often discharged through the same piping when a multi-layer resist process is performed with a single device, discharge liquid stability is required to suppress unexpected events such as metal precipitation in the piping due to interference between the cleaning liquid and other discharge liquids.

[0013] Prior art literature

[0014] Patent Literature

[0015] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-205685

[0016] [Patent Document 2] Japanese Patent No. 6714493

[0017] [Patent Document 3] Japanese Patent No. 6342998

[0018] [Patent Document 4] Japanese Patent No. 7065076

[0019] [Patent Document 5] Japanese Patent No. 7274920

[0020] [Patent Document 6] Japanese Patent No. 6879021 Summary of the Invention

[0021] [Problems to be Solved by the Invention]

[0022] The present invention is made in view of the above situation, and its purpose is to provide a cleaning liquid with excellent cleaning properties, ridge suppression properties and discharge liquid stability for removing the metal-containing film on the peripheral portion of the substrate after a metal-containing film-forming composition is coated on the substrate; a substrate cleaning method using the same; and a metal-containing film forming method using the cleaning method.

[0023] [Methods for solving the problem]

[0024] In order to solve the above-mentioned problems, the present invention provides a cleaning liquid, which is a cleaning liquid containing a metal film-forming composition.

[0025] A cleaning solution comprising (A) a solvent and (B) an organic acid,

[0026] The solvent (A) comprises at least one first solvent (A-1) having a normal boiling point of less than 160°C and at least one second solvent (A-2) having a normal boiling point of 160°C or higher and less than 500°C.

[0027] According to such a cleaning liquid, it is possible to provide a cleaning liquid having excellent cleaning properties, such as removal of a metal-containing film on the peripheral edge of a substrate, ridge suppression properties, and discharge liquid stability.

[0028] Furthermore, the second solvent (A-2) is preferably a chain ester, a chain ether, or a combination thereof.

[0029] By using such a solvent, cleaning properties such as removal of the metal-containing film on the peripheral edge of the substrate and swelling suppression properties can be improved.

[0030] In this case, the esters are preferably carboxylic acid esters.

[0031] By using such a solvent, cleaning properties such as removal of the metal-containing film on the peripheral edge of the substrate and swelling suppression properties can be improved.

[0032] Alternatively, here, the ethers are preferably (poly)alkylene glycol dibenzyl ethers or (poly)phenylene ethers.

[0033] By using such a solvent, cleaning properties such as removal of the metal-containing film on the peripheral edge of the substrate and swelling suppression properties can be improved.

[0034] Furthermore, the surface tension of the second solvent (A-2) is preferably 29.0 mN / m or more.

[0035] By using such a solvent, the swelling suppression property can be further improved.

[0036] In the solvent (A), the content of the first solvent (A-1) is preferably 30% by mass or more and 98% by mass or less, and the content of the second solvent (A-2) is preferably 2% by mass or more and 70% by mass or less.

[0037] By using such a solvent, the metal removal property and the swelling suppression property can be further improved.

[0038] Furthermore, the organic acid (B) is preferably a carboxylic acid.

[0039] By including carboxylic acid as the organic acid in the cleaning solution, the metal removal performance can be further improved.

[0040] Furthermore, the content of the organic acid (B) is preferably 1 to 70% by mass based on the total mass of the cleaning liquid.

[0041] By setting the content of the organic acid in the cleaning liquid within the above range, the metal removal performance, the temporal stability of the cleaning liquid, and the stability of the discharge liquid can be further improved.

[0042] Furthermore, the cleaning solution further contains a compound having β-diketone as (C) a chelating agent.

[0043] By further comprising the aforementioned (C) chelating agent, the cleaning solution can further enhance the metal removal performance.

[0044] The content of the chelating agent (C) is preferably 0.1 to 10% by mass based on the total mass of the cleaning liquid.

[0045] By setting the content of the chelating agent (C) in the cleaning liquid within the above range, the metal removal performance, the temporal stability of the cleaning liquid, and the stability of the discharge liquid can be further improved.

[0046] The present invention also provides a substrate cleaning method comprising the following steps: on a substrate directly or indirectly coated with a metal-containing film-forming composition, cleaning the metal-containing film-forming composition at the peripheral edge of the substrate using the above-mentioned cleaning liquid.

[0047] According to such a substrate cleaning method, it is possible to reduce metal residue on the substrate generated when applying the metal-containing film-forming composition.

[0048] The present invention also provides a method for forming a metal-containing film, comprising the following steps: directly or indirectly coating a metal-containing film-forming composition on a substrate, cleaning the metal film-forming composition on the peripheral portion of the substrate by the above-mentioned cleaning liquid; and setting the metal-containing film-forming composition to contain a metal compound and a solvent.

[0049] Such a method for forming a metal-containing film can reduce metal residue on the substrate generated when applying the metal-containing film-forming composition, and can be ideally used in the step of forming a photoresist film or a resist underlayer film using the metal-containing film-forming composition.

[0050] [Effects of the Invention]

[0051] As described above, the cleaning liquid of the present invention is a cleaning liquid comprising (A) a solvent and (B) an organic acid, characterized in that: the aforementioned (A) solvent comprises at least one first solvent (A-1) having a normal boiling point of less than 160°C, and at least one second solvent (A-2) having a normal boiling point of 160°C or more and less than 500°C. Therefore, when removing the metal-containing film-forming composition to be formed on the peripheral portion of the substrate, the drying of the cleaning liquid is slow, which can improve the metal removal efficiency of the organic acid. In addition, because the surface tension of the cleaning liquid is large, the occurrence of ridges can be suppressed. If a substrate cleaning method and a metal-containing film forming method using the same are used, the desired metal-containing film can be efficiently formed because a cleaning liquid with excellent metal cleaning properties, ridge suppression properties, and discharge liquid stability is used. These can be ideally used in the manufacture of semiconductor devices that are expected to be further miniaturized in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] [ Figure 1 ] Figure 1 (A) to (C) are flow charts of an example of forming a metal-containing film on a substrate and removing the film at the outer edge with the cleaning solution of the present invention in the present invention.

[0053] [ Figure 2 ] Figure 2 (D) to (F) are flow charts of an example of forming a metal-containing film on a substrate and peeling the metal-containing film with the cleaning solution of the present invention in the present invention.

[0054] [ Figure 3 ] Figure 3 (A) to (I) are flowcharts of an example of forming a metal-containing resist underlayer film-forming pattern in the present invention.

[0055] [ Figure 4 ] Figure 4(A) to (D) are explanatory diagrams of the method for evaluating the protrusion height in Examples. DETAILED DESCRIPTION

[0056] One of the processes performed during the formation of metal-containing film patterns in the manufacturing of semiconductor devices and other devices is edge bead removal (EBR), which involves supplying a solvent to a substrate with a metal-containing film formed on its surface to remove the unwanted film in a circular pattern around the edges of the coating. In this EBR process, a cleaning liquid is locally sprayed from a solvent nozzle onto the edge of a rotating substrate.

[0057] In the EBR treatment of metal-containing films, a cleaning liquid is required that has excellent metal cleaning properties, such as removal of the metal-containing film from the peripheral portion of the substrate when a metal-containing film-forming composition is applied to the substrate, and stability when mixed with other discharge liquids; a method for cleaning a semiconductor substrate using the cleaning liquid; and a method for forming an anti-etching lower layer film using the cleaning method.

[0058] Conventionally, cleaning solutions containing organic solvents and carboxylic acids have been used, but there is room for improvement in metal removal performance, swelling suppression performance, and discharge stability.

[0059] The inventors of the present application have discovered that a cleaning liquid containing a metal-containing film-forming composition, comprising (A) a solvent and (B) an organic acid, wherein the solvent (A) comprises at least one first solvent (A-1) having a normal boiling point of less than 160°C and at least one second solvent (A-2) having a normal boiling point of 160°C or higher and less than 500°C, can improve the above-mentioned problems, thereby completing the present invention.

[0060] That is, the present invention is a cleaning liquid, which is a cleaning liquid for a metal-containing film-forming composition, and is a cleaning liquid comprising (A) a solvent and (B) an organic acid, wherein the (A) solvent comprises at least one first solvent (A-1) having a normal boiling point of less than 160°C, and at least one second solvent (A-2) having a normal boiling point of 160°C or higher and less than 500°C.

[0061] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0062] <Cleaning fluid>

[0063] The cleaning liquid of the present invention comprises (A) a solvent and (B) an organic acid, wherein the solvent (A) comprises at least one first solvent (A-1) having a normal boiling point of less than 160°C and at least one second solvent (A-2) having a normal boiling point of 160°C or higher and less than 500°C. The cleaning liquid of the present invention is used for cleaning a substrate coated with a metal-containing film-forming composition.

[0064] ((A) Solvent)

[0065] The solvent (A) includes a first solvent (A-1) component and a second solvent (A-2) component. The solvent (A) may also include other solvent components in addition to the first solvent (A-1) component and the second solvent (A-2) component. Each of the above solvent components can be used alone or in combination of two or more.

[0066] The cleaning liquid contains (A) a solvent in addition to the organic acid (B) described later, wherein the solvent (A) includes a first solvent (A-1) having a normal boiling point of less than 160°C and a second solvent (A-2) having a normal boiling point of 160°C or higher and less than 500°C. Thus, the cleaning liquid has excellent metal cleaning properties, such as removal of a metal-containing film from the peripheral portion of a substrate when a metal-containing film-forming composition is applied to the substrate, ridge suppression properties, and stability when mixed with other discharge liquids.

[0067] The reason why the cleaning liquid exhibits the above-mentioned effects due to the above-mentioned configuration is not necessarily clear, but can be presumed as follows, for example.

[0068] In the present invention, when removing the metal-containing film, the substrate coated with the metal-containing film is rotated, and a cleaning liquid is locally sprayed from a solvent nozzle toward the peripheral end of the coating film, thereby removing the coating film at the peripheral portion. That is, it is believed that by mixing a first solvent (A-1) component with a low boiling point and a second solvent (A-2) component with a high boiling point as the (A) solvent, the drying of the cleaning liquid is alleviated, so that the organic acid effectively acts on the metal-containing film at the peripheral end, and the removability of the metal is improved. In addition, if EBR treatment is performed, in the area supplied with the cleaning liquid, the coating film is softened and dissolved by the cleaning liquid, forming a mixed layer of the coating film and the cleaning liquid. When the surface tension of the cleaning liquid is small, the cleaning liquid easily expands on the substrate, and therefore easily penetrates from the mixed layer to the coating film side. Therefore, it is believed that near the boundary with the coating film end, the mixed layer is pushed up, resulting in a tumor-like protrusion. It is considered that the cleaning liquid of the present invention contains the second solvent (A-2), which increases the surface tension of the cleaning liquid and makes it difficult to penetrate the edge side of the coating film, thereby suppressing the occurrence of ridges.

[0069] Hereinafter, each solvent component will be described in detail.

[0070] [First solvent (A-1)]

[0071] The first solvent (A-1) component is a solvent having a normal boiling point of less than 160°C.

[0072] The upper limit of the normal boiling point of the first solvent (A-1) component is preferably 158°C, more preferably 156°C. The lower limit of the normal boiling point is preferably 100°C, more preferably 120°C. By setting the normal boiling point of the first solvent (A-1) component within the above range, the temporal stability of the cleaning liquid and the stability of the discharge liquid can be improved.

[0073] Examples of the first solvent (A-1) component include alcohols, esters, ethers, and ketones.

[0074] As for the above-mentioned alcohols, for example, monohydric alcohols include methanol (boiling point: 65°C), ethanol (boiling point: 78°C), n-propanol (boiling point: 97°C), isopropanol (boiling point: 82°C), n-butanol (boiling point: 117°C), isobutanol (boiling point: 108°C), sec-butanol (boiling point: 99°C), tert-butanol (boiling point: 82°C), n-pentanol (boiling point: 138°C), isopentanol (boiling point: 132°C), 2-methylbutanol (boiling point: 136°C), sec-pentanol (boiling point: 118°C), tert-butanol (boiling point: 82°C), Examples of the alkyl glycol monoalkyl ethers include pentanol (boiling point: 102°C), 2-methylpentanol (boiling point: 148°C), 2-ethylbutanol (boiling point: 146°C), 3-methoxybutanol (boiling point: 157°C), and n-hexanol (boiling point: 157°C). Examples of the alkyl glycol monoalkyl ethers include ethylene glycol monomethyl ether (boiling point: 125°C), ethylene glycol monoethyl ether (boiling point: 135°C), propylene glycol monomethyl ether (boiling point: 121°C), propylene glycol monoethyl ether (boiling point: 133°C), and propylene glycol monopropyl ether (boiling point: 149.8°C).

[0075] Examples of the esters include carboxylic acid esters, etc. Examples of the carboxylic acid esters include butyl acetate (boiling point: 151°C), propionate esters include isoamyl propionate (boiling point: 156°C), and lactate esters include ethyl lactate (boiling point: 151°C).

[0076] Examples of the ethers include ethylene glycol monomethyl ether acetate (boiling point: 145° C.) and propylene glycol monomethyl ether acetate (boiling point: 146° C.).

[0077] Examples of the ketones include 2-heptanone (boiling point: 151° C.).

[0078] As for the first solvent (A-1) component, among these, esters and / or ethers are more preferred from the viewpoint of compatibility with the organic acid (B), chain esters and / or chain ethers are more preferred, carboxylates, alkanediol monoalkyl ethers and / or alkanediol monoalkyl ether acetates are more preferred, lactates, alkanediol monoalkyl ethers and / or alkanediol monoalkyl ether acetates are even more preferred, and propylene glycol monomethyl ether acetate (PGMEA) is particularly preferred.

[0079] The lower limit of the content of the first solvent (A-1) component in the (A) solvent is preferably 30% by mass, more preferably 35% by mass, and even more preferably 50% by mass. The upper limit of the above content is preferably 98% by mass, more preferably 97% by mass, and even more preferably 96% by mass. By ensuring that the content of the first solvent (A-1) falls within the above range, the temporal stability of the cleaning solution and the stability of the discharge liquid can be improved.

[0080] [Second solvent (A-2)]

[0081] The second solvent (A-2) component is a solvent having a normal boiling point of 160°C or higher and lower than 500°C.

[0082] The lower limit of the normal boiling point of the second solvent (A-2) component is preferably 170°C, more preferably 180°C, and even more preferably 190°C. The upper limit of the normal boiling point is less than 500°C, more preferably 450°C, even more preferably 400°C, and particularly preferably 350°C. By setting the normal boiling point of the second solvent (A-2) component within the above range, the metal removal performance, swelling suppression performance, temporal stability, and discharge stability of the cleaning liquid can be improved.

[0083] Examples of the second solvent (A-2) component include esters, alcohols, ethers, carbonates, ketones, and amides.

[0084] As for the esters, for example, carboxylic acid esters include acetates such as 2-ethylbutyl acetate (boiling point: 160°C), 2-ethylhexyl acetate (boiling point: 199°C), benzyl acetate (boiling point: 212°C), cyclohexyl acetate (boiling point: 172°C), methyl cyclohexyl acetate (boiling point: 201°C), n-nonyl acetate (boiling point: 208°C), and 1,6-diacetoxyhexane (boiling point: 260°C); acetoacetates such as methyl acetoacetate (boiling point: 169°C), ethyl acetoacetate (boiling point: 181°C); and propionic acid esters. Propionic esters such as isoamyl ester (boiling point: 161°C), oxalic acid esters such as diethyl oxalate (boiling point: 185°C) and di-n-butyl oxalate (boiling point: 239°C), lactic acid esters such as n-butyl lactate (boiling point: 185°C), malonates such as diethyl malonate (boiling point: 199°C), phthalic acid esters such as dimethyl phthalate (boiling point: 283°C), lactones such as β-propiolactone (boiling point: 162°C), γ-butyrolactone (boiling point: 204°C), γ-valerolactone (boiling point: 207°C), and γ-undecanolactone (boiling point: 286°C), etc.

[0085] As for the above-mentioned alcohols, for example, as monohydric alcohols, there are n-octanol (boiling point: 194°C), sec-octanol (boiling point: 174°C), n-nonanol (boiling point: 215°C), n-decanol (boiling point: 228°C), phenol (boiling point: 182°C), cyclohexanol (boiling point: 161°C), benzyl alcohol (boiling point: 205°C), etc., and as polyhydric alcohols, there are ethylene glycol (boiling point: 197°C), 1,2-propylene glycol (boiling point: 188°C), 1,3-butanediol (boiling point: 208°C), 2,4-diol (boiling point: 2 1-pentanediol (boiling point: 201°C), 2-methyl-2,4-pentanediol (boiling point: 196°C), 2,5-hexanediol (boiling point: 216°C), triethylene glycol (boiling point: 165°C), dipropylene glycol (boiling point: 230°C), and the like. Examples of polyol partial ethers include ethylene glycol monobutyl ether (boiling point: 171°C), ethylene glycol monophenyl ether (boiling point: 244°C), diethylene glycol monomethyl ether (boiling point: 194°C), diethylene glycol monoethyl ether (boiling point: 202°C), triethylene glycol monomethyl ether (boiling point: 2 point: 249°C), diethylene glycol monoisopropyl ether (boiling point: 207°C), diethylene glycol monobutyl ether (boiling point: 231°C), triethylene glycol monobutyl ether (boiling point: 271°C), ethylene glycol monoisobutyl ether (boiling point: 161°C), diethylene glycol monoisobutyl ether (boiling point: 220°C), ethylene glycol monohexyl ether (boiling point: 208°C), diethylene glycol monohexyl ether (boiling point: 259°C), ethylene glycol mono-2-ethylhexyl ether (boiling point: 229°C), diethylene glycol mono-2-ethylhexyl ether (boiling point: 272°C), Ethylene glycol monoallyl ether (boiling point: 161°C), diethylene glycol monophenyl ether (boiling point: 283°C), ethylene glycol monobenzyl ether (boiling point: 256°C), diethylene glycol monobenzyl ether (boiling point: 302°C), dipropylene glycol monomethyl ether (boiling point: 187°C), tripropylene glycol monomethyl ether (boiling point: 242°C), dipropylene glycol monopropyl ether (boiling point: 212°C), propylene glycol monobutyl ether (boiling point: 170°C), dipropylene glycol monobutyl ether (boiling point: 231°C), propylene glycol monophenyl ether (boiling point: 243°C), etc.

[0086] As for the above-mentioned ethers, for example, dialkylene glycol monoalkyl ether acetates include dipropylene glycol monomethyl ether acetate (normal boiling point: 213°C), diethylene glycol monoethyl ether acetate (boiling point: 217°C), and diethylene glycol monobutyl ether acetate (normal boiling point: 247°C). As for alkylene glycol monoalkyl ether acetates, butylene glycol monomethyl ether acetate (boiling point: 172°C) and ethylene glycol monobutyl ether acetate (boiling point: 188°C) are examples. As for dialkylene glycol dialkyl ethers, diethylene glycol dimethyl ether (boiling point: 162°C), diethylene glycol methyl ethyl ether (boiling point: 176°C), and diethylene glycol diethyl ether are examples. (boiling point: 189°C), diethylene glycol dibutyl ether (boiling point: 255°C), dipropylene glycol dimethyl ether (boiling point: 171°C), etc., as trialkylene glycol dialkyl ethers, for example, triethylene glycol dimethyl ether (boiling point: 216°C), etc., as tetraalkylene glycol dialkyl ethers, for example, tetraethylene glycol dimethyl ether (boiling point: 275°C), etc., and as others, for example, 1,8-eudes ether (boiling point: 176°C), diisoamyl ether (boiling point: 171°C), ethyl benzyl ether (boiling point: 189°C), diphenyl ether (boiling point: 259°C), dibenzyl ether (boiling point: 297°C), hexyl ether (boiling point: 226°C), etc.

[0087] Examples of the carbonates include ethylene carbonate (boiling point: 244° C.) and propylene carbonate (boiling point: 242° C.).

[0088] Examples of the ketones include ethyl amyl ketone (boiling point: 167° C.), dibutyl ketone (boiling point: 186° C.), and diamyl ketone (boiling point: 228° C.).

[0089] Examples of the amides include N-methylpyrrolidone (boiling point: 204°C), N,N-dimethylacetamide (boiling point: 165°C), formamide (boiling point: 210°C), N-ethylacetamide (boiling point: 206°C), and N-methylacetamide (boiling point: 206°C).

[0090] As for other second solvent (A-2) components, furfural (boiling point: 162°C), dimethyl sulfoxide (boiling point: 189°C), sulfolane (boiling point: 287°C), glycerol (boiling point: 290°C), succinonitrile (boiling point: 265°C), nitrobenzene (boiling point: 211°C), etc. can be listed.

[0091] The second solvent (A-2) component is preferably an ester, an alcohol, an ether, and / or a carbonate, and more preferably a chain ester, a chain ether, or a combination thereof.

[0092] Furthermore, the esters are preferably carboxylic acid esters, and the ethers are preferably (poly)alkylene glycol dibenzyl ethers and (poly)phenylene ethers.

[0093] A more ideal structure can be exemplified as follows.

[0094] (i) (Poly) glycol dibenzoate

[0095] (ii) (Poly)ethylene glycol dibenzyl ether

[0096] (iii) (Poly)propylene glycol dibenzyl ether

[0097] (iv) (Poly)butylene glycol dibenzyl ether

[0098] (v) Linear aliphatic dicarboxylic acid esters

[0099] (vi) (Poly)phenylene ether

[0100] [Chemistry 1]

[0101]

[0102] In the formula, n is a repeating unit, for example, n=1-100.

[0103] The surface tension of the second solvent (A-2) is preferably 29.0 mN / m or greater, more preferably 30.0 mN / m or greater, and even more preferably 31.0 mN / m or greater. The upper limit of the surface tension of the second solvent (A-2) is not particularly limited, and may be, for example, 50.0 mN / m or less. Using a solvent having such a surface tension as the second solvent can further enhance the anti-swelling properties of the cleaning solution.

[0104] Examples of the second solvent (A-2) component having a normal boiling point of 160° C. or higher and lower than 500° C. and a surface tension within the above-mentioned range include the following.

[0105] Propyl benzoate (boiling point 230°C, surface tension 34.8 mN / m), butyl benzoate (boiling point 250°C, surface tension 34.2 mN / m), benzyl benzoate (boiling point 324°C, surface tension 43.4 mN / m), diethylene glycol dibenzoate (boiling point 236°C, surface tension 45.5 mN / m), bis(2-ethylhexyl) sebacate (boiling point 377°C, surface tension 31.9 mN / m), 1,6-diacetoxyhexane (boiling point 260°C, surface tension 34.8 mN / m), γ-butyrolactone (boiling point 204°C, surface tension 44.8 mN / m), diethylene glycol monobenzyl ether (boiling point 302°C, surface tension 42.9 mN / m), and tripropylene glycol monomethyl ether (boiling point 242°C, surface tension 30.5 mN / m). The surface tension is the result of measuring the surface tension of the solvent using a Du Nouy type surface tension tester D (manufactured by Ito Seisakusho).

[0106] The lower limit of the content of the second solvent (A-2) component in the (A) solvent is 2% by mass, more preferably 3% by mass, more preferably 4% by mass, particularly preferably 4% by mass, and even more particularly preferably 8% by mass. The upper limit of the above content is 70% by mass, more preferably 65% ​​by mass, more preferably 50% by mass, particularly preferably 30% by mass, and even more particularly preferably 20% by mass. By making the content of the second solvent (A-2) fall within the above range, the metal removal property, ridge suppression property, temporal stability, and discharge stability of the cleaning liquid can be greatly improved.

[0107] In the cleaning liquid of the present invention, it is particularly preferred that the content of the first solvent (A-1) in the solvent (A) is 30% by mass to 98% by mass, and the content of the second solvent (A-2) is 2% by mass to 70% by mass.

[0108] ((B) Organic acid)

[0109] The cleaning solution of the present invention preferably contains (B) an organic acid. By adding (B) an organic acid to the cleaning solution, the removability of the metal-containing film formed on the substrate can be improved.

[0110] Examples of the organic acid (B) include carboxylic acid, sulfonic acid, sulfinic acid, organic phosphinic acid, organic phosphonic acid, phenols, enols, thiols, imides, oximes, and sulfonamides.

[0111] As for the organic acid (B), carboxylic acid is more preferable. More specifically, formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, Carboxylic acids composed of an aliphatic saturated hydrocarbon group and / or an aromatic hydrocarbon group and a carboxyl group, such as pentanoic acid, hexanoic acid, 2-ethylhexanoic acid, cyclohexanecarboxylic acid, cyclohexaneacetic acid, 1-adamantanecarboxylic acid, benzoic acid, and phenylacetic acid; monocarboxylic acids containing a fluorine atom, such as difluoroacetic acid, trifluoroacetic acid, pentafluoropropane acid, heptafluorobutyric acid, fluorophenylacetic acid, and difluorobenzoic acid; monocarboxylic acids containing a heteroatom other than a fluorine atom in a moiety other than the carboxyl group, such as 10-hydroxydecanoic acid, 5-oxohexanoic acid, 3-methoxycyclohexanecarboxylic acid, camphenic acid, dinitrobenzoic acid, nitrophenylacetic acid, lactic acid, glycolic acid, glyceric acid, salicylic acid, aniseic acid, gallic acid, and furancarboxylic acid; acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, 3-butenoic acid, angelic acid, chamomile acid, 4-pentenoic acid, cinnamic acid, and sorbic acid , propiolic acid, 2-butynoic acid and other unsaturated monocarboxylic acids, 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, 1,2,3,4-cyclobutanetetracarboxylic acid and other polycarboxylic acids composed of a single bond, an aliphatic saturated hydrocarbon group and / or an aromatic hydrocarbon group and a plurality of carboxyl groups, partial esters of the above polycarboxylic acids, difluoromalonic acid, tetrafluorophthalic acid, hexafluoroglutaric acid and other fluorine-containing polycarboxylic acids, tartaric acid, citric acid, malic acid, tartronic acid, diglycolic acid, iminodiacetic acid and other polycarboxylic acids containing heteroatoms other than fluorine atoms in the part other than the carboxyl group, unsaturated polycarboxylic acids such as maleic acid, fumaric acid and aconitic acid, etc.

[0112] (B) The organic acid is preferably at least one selected from the group consisting of formic acid, acetic acid, citric acid, oxalic acid, 2-ethylhexanoic acid, dodecanoic acid, ascorbic acid, tartaric acid, glucuronic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, and 3-butenoic acid, from the viewpoint of cleaning properties and discharge liquid stability.

[0113] The lower limit of the content of the organic acid (B) in the total components of the cleaning solution is preferably 1% by mass, more preferably 1.5% by mass, even more preferably 2% by mass, and particularly preferably 3% by mass. The upper limit of the above content is preferably 70% by mass, more preferably 60% by mass, even more preferably 55% by mass, and particularly preferably 50% by mass. By ensuring that the content of the organic acid falls within the above range, cleaning properties and discharge liquid stability can be further improved.

[0114] In the cleaning liquid of the present invention, the content of the organic acid (B) is preferably 1 to 70% by mass based on the total mass of the cleaning liquid.

[0115] ((C) Chelating agent)

[0116] The cleaning solution of the present invention may also contain (C) a chelating agent to further enhance metal removal performance. As for chelating agents, compounds having a β-diketone structure are ideal from the perspective of cleaning performance. Specifically, examples include 2,4-pentanedione (acetylacetone), 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, acetoacetate, allyl acetoacetate, α-alkyl-substituted acetoacetate, β-ketovalerate, benzoyl acetate, and 1,3-acetone dicarboxylate.

[0117] In the cleaning solution of the present invention, the content of the chelating agent (C) is preferably 0.1 to 10% by mass based on the total mass of the cleaning solution.

[0118] (Other ingredients)

[0119] The cleaning solution of the present invention may contain other components in addition to the above components. Examples of other components include inorganic hydrofluoric acid, tetraalkylammonium compounds, and surfactants.

[0120] Examples of the inorganic hydrofluoric acid include hexafluorosilicic acid, hexafluorophosphoric acid, and fluoroboric acid.

[0121] Examples of the tetraalkylammonium compound include tetramethylammonium fluoride, tetrabutylammonium fluoride, and tetrabutylammonium fluorosilicate.

[0122] As the surfactant, for example, those described in paragraphs

[0142] to

[0147] of JP-A-2009-269953 can be used.

[0123] Each additive may be used alone or in combination of two or more. In the cleaning solution of the present invention, the content of the additive is preferably 0 to 10% by mass relative to the total mass of the cleaning solution.

[0124] <Preparation Method of Cleaning Solution>

[0125] The cleaning solution of the present invention can be prepared by mixing (A) a solvent, (B) an organic acid, and, if necessary, (C) a chelating agent and optional components in a predetermined ratio, and filtering the resulting mixture preferably through a membrane filter having a pore size of 0.5 μm or less.

[0126] <Substrate Cleaning Method and Metal-Containing Film Formation Method>

[0127] The cleaning liquid of the present invention is used for removing a metal-containing film from the peripheral portion of a substrate when a metal-containing film-forming composition is applied to the substrate.

[0128] Therefore, the present invention provides a substrate cleaning method comprising the following steps: for a substrate directly or indirectly coated with a metal-containing film-forming composition, the metal-containing film-forming composition is cleaned from the peripheral portion of the substrate using the cleaning solution of the present invention.

[0129] In addition, the present invention provides a method for forming a metal-containing film, comprising the following steps: a step of directly or indirectly coating a metal-containing film-forming composition on a substrate (coating step); and a step of cleaning the metal-containing film-forming composition on the peripheral portion of the substrate using the cleaning liquid of the present invention (cleaning step), so that the metal-containing film-forming composition contains a metal compound and a solvent.

[0130] When the metal-containing film-forming composition is a material for a resist underlayer film, the following steps are preferably performed as a resist pattern forming step after the cleaning step: a step of directly or indirectly forming a photoresist film on the metal-containing film formed in the coating step; a step of exposing the photoresist film; a step of forming a photoresist pattern by development; and a step of directly or indirectly transferring the resist pattern to the metal-containing film by etching using the resist pattern as a mask. Hereinafter, a method including these steps will also be referred to as a "semiconductor substrate manufacturing method."

[0131] In the case where the metal-containing film-forming composition is a material for a photoresist film, it is ideal to include the following steps after the above-mentioned cleaning step: a step of exposing the above-mentioned photoresist film; a step of forming a photoresist pattern by development; and a step of directly or indirectly transferring the resist pattern to a substrate by etching using the above-mentioned resist pattern as a mask.

[0132] The peripheral edge of the substrate refers to, for example, the peripheral portion of the substrate within a length of 3.0 cm from the outer edge of the substrate to the center of the substrate. The length from the outer edge of the substrate to the center of the substrate can be set to 2.0 cm, 1.0 cm, 0.5 cm, or 0.2 cm.

[0133] In the case where the metal-containing film-forming composition is a material for the resist underlayer film, the method for manufacturing the semiconductor substrate may also, as needed, include a step of directly or indirectly forming an organic resist intermediate film on the substrate having the metal-containing film formed by the above-mentioned coating step before the above-mentioned resist pattern forming step. (Organic resist intermediate film forming step).

[0134] In the case where the metal-containing film-forming composition is a material for the resist underlayer film, the method for manufacturing the semiconductor substrate may also, as needed, include a step of directly or indirectly forming a silicon-containing film on the substrate having the metal-containing film formed by the above-mentioned coating step before the above-mentioned resist pattern forming step. (Silicon-containing film forming step).

[0135] Hereinafter, each step of the method for manufacturing a semiconductor substrate including the metal-containing film-forming composition and the cleaning liquid, and the organic resist intermediate film forming step and the silicon-containing film forming step as optional steps will be described.

[0136] <Metal-Containing Film-Forming Composition>

[0137] The metal-containing film-forming composition to which the cleaning solution of the present invention can be applied is not particularly limited as long as it contains (M) a metal compound and (B) a solvent. The composition may also contain any other optional components. The metal-containing film-forming composition is preferably a material that can be used as a photoresist film or a resist underlayer film.

[0138] The (M) metal compound is preferably a compound containing a metal atom and an oxygen atom. Examples of the metal atom constituting the (M) metal compound include metal atoms from Groups 3 to 16 of the periodic table (excluding silicon atoms). The (M) metal compound may contain one or more metal atoms.

[0139] Examples of the metal atom of Group 3 include scandium, yttrium, lanthanum, and cerium.

[0140] Examples of the metal atom of Group 4 include titanium, zirconium, and hafnium.

[0141] Examples of the metal atom of Group 5 include vanadium, niobium, and tantalum.

[0142] Examples of the metal atom of Group 6 include chromium, molybdenum, and tungsten.

[0143] Examples of the metal atom of Group 7 include manganese and rhenium.

[0144] Examples of the metal atom of Group 8 include iron, ruthenium, and osmium.

[0145] Examples of the metal atom of Group 9 include cobalt, rhodium, and iridium.

[0146] Examples of the metal atom of Group 10 include nickel, palladium, platinum and the like.

[0147] Examples of the metal atom of Group 11 include copper, silver, and gold.

[0148] Examples of the metal atom of Group 12 include zinc, cadmium, and mercury.

[0149] Examples of the metal atom of Group 13 include aluminum, gallium, and indium.

[0150] Examples of the metal atom of Group 14 include germanium, tin, and lead.

[0151] Examples of the metal atom of Group 15 include antimony and bismuth.

[0152] Examples of the metal atom of Group 16 include tellurium and the like.

[0153] The metal atom constituting the metal compound (M) is preferably a metal atom from Groups 3 to 16, more preferably a metal atom from Groups 4 to 14, even more preferably a metal atom from Groups 4, 5, and 14, and particularly preferably a metal atom from Group 4. Specifically, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, molybdenum, indium, tin, hafnium, tantalum, tungsten, and bismuth, or a combination thereof, are preferred.

[0154] Components other than the metal atom that constitute the metal compound (M) are preferably ligands containing one or more hydrolyzable groups or derived from organic acids (hereinafter also referred to as "(a) organic acids"), hydroxy acid esters, β-diketones, β-ketoesters, α,α-dicarboxylates, amines, amides, olefins, hydrocarbons having π bonds, and compounds containing diphosphines. Here, "organic acid" refers to an organic compound that exhibits acidity, and "organic compound" refers to a compound having at least one carbon atom. The presence of the (a) organic acid also includes an organic acid anion obtained by removing a hydrogen ion from the (a) organic acid.

[0155] Examples of the hydrolyzable group include a halogen atom, an alkoxy group, and an acyloxy group.

[0156] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0157] The alkoxy group is preferably an alkoxy group having 1 to 10 carbon atoms, and examples thereof include methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, and octyl groups.

[0158] Examples of the acyloxy group include acetyloxy, acetyloxy, propionyloxy, butyryloxy, tert-butyryloxy, tert-valeryloxy, n-hexanecarbonyloxy, and n-octanecarbonyloxy groups.

[0159] The hydrolyzable group is preferably an alkoxy group or an acyloxy group, and more preferably an n-propoxy group, an isopropoxy group, a butoxy group, or an octyl group.

[0160] Examples of the (a) organic acid include carboxylic acid, sulfonic acid, sulfinic acid, organic phosphinic acid, organic phosphonic acid, phenols, enols, thiols, acid imides, oximes, and sulfonamides.

[0161] Examples of the carboxylic acids include 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, linoleic acid, 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. Examples of the carboxylic acids include dicarboxylic acids such as oxalic acid, malonic acid, maleic acid, methylmalonic acid, fumaric acid, adipic acid, sebacic acid, phthalic acid, and tartaric acid. Examples of the carboxylic acids include carboxylic acids having three or more carboxyl groups such as citric acid.

[0162] Examples of the sulfonic acid include benzenesulfonic acid and p-toluenesulfonic acid.

[0163] Examples of the sulfinic acid include benzenesulfinic acid and p-toluenesulfinic acid.

[0164] Examples of the organic phosphinic acid include diethylphosphinic acid, methylphenylphosphinic acid, and diphenylphosphinic acid.

[0165] Examples of the organic phosphonic acid include methylphosphonic acid, ethylphosphonic acid, tert-butylphosphonic acid, cyclohexylphosphonic acid, and phenylphosphonic acid.

[0166] Examples of the phenols include monovalent phenols such as phenol, cresol, 2,6-xylenol, and naphthol; divalent phenols such as catechol, resorcinol, hydroquinone, and 1,2-naphthalenediol; and trivalent or higher phenols such as gallol and 2,3,6-naphthalenetriol.

[0167] Examples of the enol include 2-hydroxy-3-methyl-2-butene and 3-hydroxy-4-methyl-3-hexene.

[0168] Examples of the mercaptan include mercaptoethanol and mercaptopropanol.

[0169] Examples of the acid imide include carboxylic acid imides such as maleimide and succinimide, and sulfonic acid imides such as bis(trifluoromethanesulfonic acid)imide and bis(pentafluoroethanesulfonic acid)imide.

[0170] Examples of the oxime include aldoximes such as benzaldehyde oxime and salicylaldehyde oxime, and ketoximes such as diethylketoxime, methylethylketoxime and cyclohexanone oxime.

[0171] Examples of the sulfonamide include methylsulfonamide, ethylsulfonamide, benzenesulfonamide, and toluenesulfonamide.

[0172] As the organic acid (a), a carboxylic acid having 1 to 10 carbon atoms is preferred.

[0173] Examples of the hydroxy acid ester include glycolic acid ester, lactic acid ester, 2-hydroxycyclohexane-1-carboxylic acid ester, and salicylic acid ester.

[0174] Examples of the β-diketone include 2,4-pentanedione, 3-methyl-2,4-pentanedione, and 3-ethyl-2,4-pentanedione.

[0175] Examples of the β-ketoester include acetoacetate, α-alkyl-substituted acetoacetate, β-ketovalerate, benzoyl acetate, and 1,3-acetonedicarboxylate.

[0176] Examples of the α,α-dicarboxylic acid esters include malonate diesters, α-alkyl-substituted malonate diesters, α-cycloalkyl-substituted malonate diesters, and α-aryl-substituted malonate diesters.

[0177] Examples of the amine-containing compound include pyridine, trimethylamine, piperidine, diethanolamine, and triethanolamine.

[0178] Examples of the compound containing amide include compounds containing unsubstituted amide (NH2), methylamide (NHMe), dimethylamide (NMe2), diethylamide (NEt2), dipropylamide (NPr2), and the like.

[0179] Examples of the compound containing olefins include chain olefins such as ethylene and propylene, and cyclic olefins such as cyclopentene, cyclohexene, and norbornene.

[0180] Examples of hydrocarbons having π bonds include chain dienes such as butadiene and isoprene, cyclic dienes such as cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene, and norbornadiene, and aromatic hydrocarbons such as benzene, toluene, xylene, hexamethylbenzene, naphthalene, and indene.

[0181] Examples of the diphosphine-containing compound include 1,1-bis(diphenylphosphino)methane, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl, and 1,1′-bis(diphenylphosphino)ferrocene.

[0182] Examples of the metal compound (M) include compounds represented by the following formula (M-1). By using such a metal compound (M-1), a stable metal compound (M) can be formed, thereby improving dry etching resistance.

[0183] [Chemistry 2]

[0184] L a M(=O) b X c (M-1)

[0185] Wherein, 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 ligand or a multidentate ligand having 1 to 30 carbon atoms, and X is selected from halogen atoms, alkoxy groups, carboxylate groups, acyloxy groups, -NR a R b Hydrolyzable group. a and R b Each independently represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. a+c=1 to 6, where a is an integer of 0 to 4, b is an integer of 0 to 2, and c is an integer of 0 to 6.

[0186] Examples of the hydrolyzable group X in the formula (M-1) include a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, and -NR a R b . R a and R b Each independently represents preferably a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0187] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0188] Examples of the alkoxy group include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, and tert-butoxy.

[0189] Examples of the carboxylic acid ester group include 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, linoleic acid, 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; examples of dicarboxylic acids include oxalic acid, malonic acid, maleic acid, methylmalonic acid, fumaric acid, adipic acid, sebacic acid, phthalic acid, and tartaric acid; and examples of ligands derived from carboxylic acids having three or more carboxyl groups, such as citric acid.

[0190] Examples of the acyloxy group include acetyloxy, acetyloxy, propionyloxy, butyryloxy, tert-butyryloxy, tert-valeryloxy, n-hexanecarbonyloxy, and n-octanecarbonyloxy groups.

[0191] Regarding the above-NRa R b For example, unsubstituted amino, methylamino, dimethylamino, diethylamino, dipropylamino and the like can be mentioned.

[0192] The hydrolyzable group X is preferably an alkoxy group, more preferably an isopropoxy group, an n-butoxy group, or a tert-butoxy group.

[0193] (monodentate ligand)

[0194] Examples of the monodentate ligand L include hydroxy ligands, carboxyl ligands, amide ligands, amine ligands, and olefin ligands.

[0195] Examples of the carboxyl ligands include 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, linoleic acid, 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. Examples of the carboxyl ligands include dicarboxylic acids such as oxalic acid, malonic acid, maleic acid, methylmalonic acid, fumaric acid, adipic acid, sebacic acid, phthalic acid, and tartaric acid. In addition, examples include ligands derived from carboxylic acids having three or more carboxyl groups, such as citric acid.

[0196] Examples of the amide ligand include unsubstituted amide ligand (NH2), methylamide ligand (NHMe), dimethylamide ligand (NMe2), diethylamide ligand (NEt2), and dipropylamide ligand (NPr2).

[0197] Examples of the amine ligand include pyridine, trimethylamine ligand, and piperidine ligand.

[0198] Examples of the olefin ligand include chain olefins such as ethylene and propylene, and cyclic olefins such as cyclopentene, cyclohexene, and norbornene.

[0199] (Multidentate Ligand)

[0200] Examples of the polydentate ligand L include ligands derived from hydroxy acid esters, ligands derived from β-diketones, ligands derived from β-ketoesters, ligands derived from α,α-dicarboxylates, hydrocarbons having a π bond, and diphosphines.

[0201] Examples of the hydroxy acid ester include glycolic acid ester, lactic acid ester, 2-hydroxycyclohexane-1-carboxylic acid ester, and salicylic acid ester.

[0202] Examples of the β-diketone include acetoacetate, α-alkyl-substituted acetoacetate, β-ketovalerate, benzoyl acetate, and 1,3-acetonedicarboxylate.

[0203] Examples of the β-ketoester include acetoacetate, α-alkyl-substituted acetoacetate, β-ketovalerate, benzoyl acetate, and 1,3-acetonedicarboxylate.

[0204] Examples of the α,α-dicarboxylic acid esters include malonate diesters, α-alkyl-substituted malonate diesters, α-cycloalkyl-substituted malonate diesters, and α-aryl-substituted malonate diesters.

[0205] Examples of the hydrocarbons having a π bond include chain dienes such as butadiene and isoprene, cyclic dienes such as cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene, and norbornadiene, and aromatic hydrocarbons such as benzene, toluene, xylene, hexamethylbenzene, naphthalene, and indene.

[0206] Examples of the diphosphine include 1,1-bis(diphenylphosphino)methane, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl, and 1,1′-bis(diphenylphosphino)ferrocene.

[0207] The monodentate and polydentate ligands may also contain crosslinkable groups. Crosslinkable groups preferably include any of vinyl, allyl, allyloxy, ethynyl, propargyl, propargyloxy, epoxy, and oxetane. Using metal compounds containing such ligands allows the formation of metal-containing films with excellent thermosetting properties.

[0208] Furthermore, the metal compound (M) may contain anions of oxygen-containing acids (phosphate ions, sulfate ions, chromate ions, tungstate ions (WO4 2- ), molybdate ion (MoO4 2- ) etc.), inorganic anions such as polyacid anions formed by condensation of multiple oxygen-containing acids, or compounds of their mixtures.

[0209] For the above-mentioned polyacid, it can be the same polyacid anion (Mm'On') c- It can also be a heteropolyacid anion (X l 'Mm'On') c- In the above ionic formula, M represents a polyatom, X represents a heteroatom, m' represents the composition ratio of the polyatom, n' represents the composition ratio of oxygen, and l' represents the composition ratio of the heteroatom. c is a valence number. Examples of the polyatom M include Mo, W, Ti, and Nb. In addition, examples of the heteroatom X include Si, P, As, S, Fe, and Co. In addition, a portion of the polyatom may also contain Na + 、H + Equivalent cations.

[0210] Among them, from the viewpoint of excellent heat resistance, anions of inorganic acids containing at least one of tungsten (W) and molybdenum (Mo) are preferred.

[0211] Examples of the polybasic acid containing at least one of tungsten (W) and molybdenum (Mo) include tungstate ions [W 10 O 32 ] 4- 、Molybdate ion [Mo6O 19 ] 2- ; is the phosphotungstate ion of heteropolyacid [PW 12 O 40 ] 3- 、[P2W 18 O 62 ] 6- , silicotungstate ion [SiW 12 O 40 ] 4- 、Phosphombohedral ion [PMo 12 O 40 ] 3- 、SiMo 2 12 O 40 ] 4- 、phosphotungstomolybdate 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 of 1 to 17), silicotungstenmolybdate ion [SiW 12- x Mo x O 40 ] 4- (x is an integer of 1 to 11), etc. With respect to the polyacid containing at least one of tungsten (W) and molybdenum (Mo), from the perspective of heat resistance and ease of obtaining raw materials, heteropolyacids are particularly preferred, and heteropolyacids containing phosphorus (P) are even more preferred.

[0212] Furthermore, phosphotungstomolybdate ions [PW 10 Mo2O 40 ] 3- 、[PW 11 Mo1O 40 ] 3- , phosphotungstate ion [PW 12 O 40 ] 3- , either one is more ideal considering the heat resistance.

[0213] The metal compound (M) may be a hydrolyzate of a metal compound containing a hydrolyzable group, a hydrolysis-condensation product of a metal compound containing a hydrolyzable group, or a combination thereof. The "hydrolysis-condensation reaction" herein refers to a reaction in which a hydrolyzable group in a metal compound is hydrolyzed to convert to -OH, and the resulting two -OH groups undergo dehydration condensation to form -O-.

[0214] Alternatively, a compound formed by reacting a substance capable of becoming a monodentate ligand or a polydentate ligand in these compounds by a ligand exchange reaction may be used; or a compound formed by reacting a substance capable of becoming a monodentate ligand or a polydentate ligand in a hydrolysis reaction product of a metal-containing compound having a hydrolyzable group or a hydrolysis-condensation reaction product of a metal-containing compound having a hydrolyzable group may be used.

[0215] Specific examples of the (M) metal compound are shown below, but are not limited to these.

[0216] Examples of titanium-containing compounds include diisopropoxybis(acetylacetonate)titanium(IV), tetra-n-butoxytitanium(IV), tetra-n-propoxytitanium(IV), tetraisopropoxytitanium(IV), tri-n-butoxymonostearatetitanium(IV), tetra(2-ethylhexyl)orthotitanate, dihydroxybis(hydrogenated lactide)titanium(IV), butoxide titanium(IV) oligomer, aminopropyltrimethoxytitanium(IV), triethoxymono(acetylacetonate)titanium(IV), tri-n-propoxymono(acetylacetonate)titanium(IV), triisopropoxymono(acetylacetonate)titanium, and di-n-butoxybis(acetylacetonate)titanium(IV).

[0217] Examples of compounds containing chromium include tris(2-ethylhexanoate)chromium(III), tris(2,4-pentanedione)chromium(III), bis(2,2,6,6-tetramethyl-3,5-heptanedione)chromium(II), tris(trifluoro-2,4-pentanedione)chromium(III), chromium(III) pyridine-2-carboxylate, chromium(III) chloride, chromium(II) chloride, and chromium(II) cyclohexanecarboxylate.

[0218] Examples of nickel-containing compounds include nickel (II) acetate, nickel chloride, nickel (II) 2-ethylhexanoate, nickel (II) bis(2,4-pentanedione)ate hydrate, nickel (II) bis(hexafluoroacetylacetonate), nickel (II) 2-amino-5-methylbenzenesulfonate, nickel (II) trifluoromethanesulfonate, nickel (II) bis(2,2,6,6-tetramethyl-3,5-heptanedione)ate, and nickel (II) propionate.

[0219] Examples of the manganese-containing compound include tris(2,2,6,6-tetramethyl-3,5-heptanedione)manganese(III).

[0220] Examples of the iron-containing compound include tris(2,2,6,6-tetramethyl-3,5-heptanedione)iron(III), oxocyclohexanecarboxylate iron(II), and ferric chloride.

[0221] Examples of the cobalt-containing compound include dichloro[ethylenebis(diphenylphosphine)]cobalt, cobalt(II) bromide, cobalt(II) acetate, tris(1,3-diphenyl-1,3-propanedione)cobalt(III), and cyclopentylcobalt(II) acetate.

[0222] Examples of the copper-containing compound include copper (II) acetate, monobutyl copper (II) phthalate, copper (II) acetylacetonate, copper (I) heptanoate, and copper (II) 2-ethylhexanoate.

[0223] Examples of the zinc-containing compound include zinc diisopropylate, zinc (II) acetate, zinc (II) chloride, and zinc (II) 4-vinylbenzoate.

[0224] Examples of zirconium compounds include dibutoxybis(ethyl acetoacetate) zirconium(IV), di-n-butoxybis(acetylacetonate) zirconium(IV), tetra-n-butoxyzirconium(IV), tetra-n-propoxyzirconium(IV), tetraisopropoxyzirconium(IV), aminopropyltriethoxyzirconium(IV), 2-(3,4-epoxycyclohexyl)ethyltrimethoxyzirconium(IV), γ-glycidoxypropyltrimethoxyzirconium(IV), 3-isocyanopropyltrimethoxyzirconium(IV), triethoxymono(acetylacetonate)zirconium(IV), and the like. ), tri-n-propoxymono(acetylacetonate)zirconium(IV), tri-isopropoxymono(acetylacetonate)zirconium(IV), tri(3-methacryloyloxypropyl)methoxyzirconium(IV), tri(3-acryloyloxypropyl)methoxyzirconium(IV), zirconium(IV) acetate, zirconium(IV) acetate oxide, zirconium(II) bis(2-ethylhexanoate), zirconium(IV) tetra(2-ethylhexanoate), zirconium(IV) bis(2-ethylhexanoate)oxy, zirconium(IV) nitrate, zirconium(IV) chloride, zirconium(IV) carboxyethyl acrylate, etc.

[0225] Compounds containing molybdenum include pentaethoxy molybdenum (V), hexaethoxy molybdenum (VI), isopropoxy molybdenum (V), platinum (II) acetate dimer, bis(acetylacetonate) molybdenum (IV) oxide, bis(2,2,6,6-tetramethyl-3,5-heptanedione) oxide molybdenum (VI), molybdenum 2-ethylhexanoate, platinum (V) chloride, platinum (III) chloride, and the like.

[0226] Examples of the compound containing indium include tris(1,3-diphenyl-1,3-propanedione)indium(III), indium(III) ethylbutyrate, indium(III) acetate, and indium(III) triisopropoxide.

[0227] Examples of tin compounds include tin(II) acetate, tin(IV) acetate, tin(II) acetylacetonate, tin(IV) tert-butoxide, tin tetra-n-butoxide, tin tetraisopropoxide, 4-fluorophenyltin(II) acetate, and tin(II) 2-ethylhexanoate.

[0228] Examples of hafnium-containing compounds include diisopropoxybis(acetylacetonate)hafnium(IV), tetrabutoxyhafnium(IV), tetraisopropoxyhafnium(IV), tetraethoxyhafnium(IV), dichlorobis(cyclopentadienyl)hafnium(IV), hafnium(IV) chloride, tetrakis(dimethylamide)hafnium(IV), tetrakis(ethylmethylamide)hafnium(IV), carboxyethylacrylate hafnium, bis(cyclopentadienyl)hafnium(IV) dichloride, trifluoromethanesulfonate hafnium(IV) hydrate, and carboxyethylacrylate hafnium(IV).

[0229] As for the compounds containing tantalum, there can be mentioned tantalum (V) methanol, tantalum (V) ethoxide, tetrabutoxytantalum (IV), pentabutoxytantalum (V), pentaethoxytantalum (V), tantalum (V) chloride, penta(dimethylamino)tantalum (V), tris(diethylamide)(tert-butylimide)-tantalum (V), bis(2-ethylhexanoate)tantalum (II), etc.

[0230] Examples of compounds containing tungsten include tungsten (VI) ethoxide, tetrabutoxytungsten (IV), pentabutoxytungsten (V), pentamethoxytungsten (V), hexabutoxytungsten (VI), hexaethoxytungsten (VI), and dichlorobis(cyclopentadienyl)tungsten (IV).

[0231] Examples of bismuth-containing compounds include bismuth (III) n-butoxide, bismuth (III) tri-tert-pentyloxybismuth (III), bismuth (III) triethoxy, bismuth (III) tris(β-diketonate)bismuth (III), bismuth (III) neodecanoate, tris(2-naphthol)bismuth (III), bismuth (III) fluoride, bismuth (III) bromide, bismuth (III) iodide, bismuth (III) oxychloride, bismuth (III) acetate, bismuth (III) subsalicylate, bismuth (III) 2-ethylhexanoate, and bismuth (III) trifluoromethanesulfonate.

[0232] <(B) Solvent>

[0233] The (B) solvent that can be used in the metal-containing film-forming composition of the present invention is not particularly limited as long as it can dissolve the (M) metal compound and other additives contained therein.

[0234] Specifically, for example, the organic solvents described in paragraphs

[0091] to

[0092] of JP-A-2007-199653 can be added. More specifically, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and γ-butyrolactone, or a mixture containing one or more of these can be preferably used. 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-propanol, -pentanol, acetone, tetrahydrofuran, toluene, hexane, ethyl acetate, cyclohexanone, methyl amyl ketone, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, diamyl 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 mono-tert-butyl ether acetate, methyl isobutyl ketone, cyclopentyl methyl ether, etc.

[0235] The amount of the solvent (B) to be added is preferably in the range of 200 to 10,000 parts, more preferably 250 to 5,000 parts, based on 100 parts by mass of the metal compound (M).

[0236] <Other additives>

[0237] Depending on the application of the metal-containing film-forming composition, the composition may contain at least one of (C) a cross-linking agent, (D) an acid generator, and (E) a surfactant.

[0238] Components that may be contained in the metal-containing film-forming composition other than the aforementioned (M) metal compound and (B) organic solvent will be described below.

[0239] [(C) Cross-linking agent]

[0240] When the metal-containing film-forming composition is used as a resist underlayer film, a crosslinking agent (C) may be added to improve curability and further suppress intermixing with the resist upperlayer film.

[0241] As a cross-linking agent, there is no particular limitation, and cross-linking agents of various known systems can be widely used. As an example, melamine-based cross-linking agents, glycoluril-based cross-linking agents, benzoguanamine-based cross-linking agents, urea-based cross-linking agents, β-hydroxyalkylamide-based cross-linking agents, isocyanurate-based cross-linking agents, aziridine-based cross-linking agents, oxazoline-based cross-linking agents, epoxy-based cross-linking agents, and phenol-based cross-linking agents can be exemplified. The above-mentioned (C) cross-linking agent can be used alone or in combination of two or more. The amount added when adding the cross-linking agent is preferably 5 to 50 parts, more preferably 10 to 40 parts, relative to 100 parts of the above-mentioned (M) metal compound. If the addition amount is 5 parts or more, sufficient curability can be exhibited and intermixing with the upper film of the resist can be suppressed. On the other hand, if the addition amount is 50 parts or less, there is no risk of deterioration of dry etching resistance due to a lower ratio of the (M) metal compound in the composition.

[0242] Specific examples of the melamine-based crosslinking agent include hexamethoxymethylated melamine, hexabutoxymethylated melamine, alkoxy and / or hydroxyl-substituted melamines thereof, and partially self-condensed melamines thereof.

[0243] Specific examples of glycoluril-based crosslinking agents include tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril, alkoxy and / or hydroxyl-substituted products thereof, and partially self-condensed products thereof.

[0244] Specific examples of the benzoguanamine-based crosslinking agent include tetramethoxymethylated benzoguanamine, tetrabutoxymethylated benzoguanamine, alkoxy and / or hydroxyl-substituted products thereof, and partially self-condensed products thereof.

[0245] Specific examples of the urea crosslinking agent include dimethoxymethylated dimethoxyethylene urea, alkoxy and / or hydroxyl substituted products thereof, and partial self-condensation products thereof.

[0246] Specific examples of the β-hydroxyalkylamide crosslinking agent include N,N,N′,N′-tetrakis(2-hydroxyethyl)adipamide.

[0247] Specific examples of the isocyanurate-based crosslinking agent include triglycidyl isocyanurate and triallyl isocyanurate.

[0248] Specific examples of the aziridine-based crosslinking agent include 4,4′-bis(ethyleneiminocarbonylamino)diphenylmethane and 2,2-bis(hydroxymethylbutanol-tris[3-(1-aziridinyl)propionate].

[0249] Specific examples of the oxazoline crosslinking agent include 2,2'-isopropylidenebis(4-benzyl-2-oxazoline), 2,2'-isopropylidenebis(4-phenyl-2-oxazoline), 2,2'-methylenebis-4,5-diphenyl-2-oxazoline, 2,2'-methylenebis-4-phenyl-2-oxazoline, 2,2'-methylenebis-4-tert-butyl-2-oxazoline, 2,2'-bis(2-oxazoline), 1,3-phenylenebis(2-oxazoline), 1,4-phenylenebis(2-oxazoline), and 2-isopropenyloxazoline copolymers.

[0250] Specific examples of epoxy crosslinking agents include diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, poly(glycidyl methacrylate), trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, and pentaerythritol tetraglycidyl ether.

[0251] Specific examples of the phenolic crosslinking agent include compounds represented by the following general formula (10).

[0252] [Chemistry 3]

[0253]

[0254] Wherein, Q is a single bond, or a carbon number of 1 to 20 1 Hydrocarbyl group with valence R 16 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. 1 An integer from 1 to 5.

[0255] Q is a single bond, or a carbon number of 1 to 20 1 Hydrocarbyl with valence. 1 is an integer of 1 to 5, more preferably 2 or 3. Specific examples of Q include methane, ethane, propane, butane, isobutane, pentane, cyclopentane, hexane, cyclohexane, methylpentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, benzene, toluene, xylene, ethylbenzene, ethylisopropylbenzene, diisopropylbenzene, methylnaphthalene, ethylnaphthalene, and eicosane. 16 It is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Specific examples of the alkyl group having 1 to 20 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, octyl, ethylhexyl, decyl, and eicosyl, and it is preferably a hydrogen atom or a methyl group.

[0256] The compound represented by the general formula (10) is preferably a hexamethoxymethylated form of trisphenolmethane, trisphenolethane, 1,1,1-tris(4-hydroxyphenyl)ethane, or tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene, from the viewpoint of improving curability and film thickness uniformity.

[0257] <(D) Acid Generator>

[0258] The metal-containing film-forming composition of the present invention may contain an acid generator, for example, a compound that generates an acid in response to active light or radiation (photoacid generator).

[0259] The photoacid generator may be any compound that generates an acid upon exposure to high-energy radiation. Preferred photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimides, and oxime-O-sulfonate acid generators. Specific examples of acid generators include those described in paragraphs

[0122] to

[0142] of Japanese Patent Application Laid-Open No. 2008-111103, Japanese Patent Application Laid-Open No. 2009-080474, and Japanese Patent Application Laid-Open No. 2015-026064.

[0260] The acid generators may be used alone or in combination of two or more. The amount of the acid generator added is preferably 0.05 to 50 parts, more preferably 0.1 to 10 parts, relative to 100 parts by mass of the metal compound (M).

[0261] <(E) Surfactant>

[0262] A surfactant (E) may be added to the metal-containing film-forming composition to improve coating properties during spin coating. Surfactants such as those described in

[0142] to

[0147] of JP-A-2009-269953 can be used. The amount of the surfactant added is preferably 0.01 to 10 parts, more preferably 0.05 to 5 parts, relative to 100 parts by mass of the metal compound (M).

[0263] [Coating Step]

[0264] In the coating step, the metal-containing film-forming composition is applied directly or indirectly to the substrate. The method for applying the metal-containing film-forming composition is not particularly limited, and can be carried out by any suitable method, such as spin coating, cast coating, or roll coating. This forms a coating film, and the metal-containing film is formed by volatilization of the solvent (B).

[0265] The substrate on which the metal-containing film-forming composition is applied is not particularly limited, and substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, and Al can be used, with the target layer formed on the substrate. The target layer can be a variety of low-k films such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, as well as their stopper films. Typically, the target layer can be formed to a thickness of 50 to 10,000 nm, particularly 100 to 5,000 nm. Furthermore, when forming the target layer, the substrate and target layer can be made of different materials.

[0266] 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 average thickness is preferably 500 nm, more preferably 200 nm, and even more preferably 60 nm. The method for measuring the average thickness is as described in the Examples.

[0267] The semiconductor substrate manufacturing method preferably further includes a step of heating the coating film formed by the coating step (hereinafter also referred to as the "heating step"). Heating the coating film promotes the formation of the metal-containing film. More specifically, heating the coating film promotes volatilization of the solvent (B).

[0268] The coating film is typically heated under atmospheric air, but can also be heated under a nitrogen atmosphere. The lower limit of the heating temperature is preferably 150°C, more preferably 200°C. The upper limit of the heating 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 heating time is preferably 1,200 seconds, more preferably 600 seconds.

[0269] [Organic Resist Interlayer Film Formation Step]

[0270] In this step, before the resist pattern forming step, an organic resist intermediate film may be formed directly or indirectly on the substrate having the metal-containing film formed in the coating step.

[0271] The organic interlayer film can be formed by applying an organic interlayer film-forming composition, etc. Examples of methods for forming an organic resist interlayer film by applying an organic resist interlayer film-forming composition include methods such as directly or indirectly applying the organic resist interlayer film-forming composition to a substrate having the metal-containing film, and then heating and exposing the resulting coating film to cure the coating film.

[0272] As materials for the organic resist interlayer film that can be used in the above-mentioned organic resist interlayer film, materials that are already known as underlayer films for three-layer resist methods or two-layer resist methods using a silicon resist composition can be used. In addition to the 4,4'-(9-fluorenylidene)bisphenol novolac resin (molecular weight 11,000) described in Japanese Patent Application Laid-Open No. 2005-128509, various resins, typified by novolac resins, that are known as materials for resist underlayers (or interlayers) for two-layer and three-layer resist methods can also be used. Furthermore, when it is desired to improve heat resistance compared to conventional novolacs, a polycyclic backbone such as 6,6'-(9-fluorenylidene)-bis(2-naphthol) novolac resin can be added, and polyimide resins can also be selected (for example, Japanese Patent Application Laid-Open No. 2004-153125).

[0273] The organic resist interlayer film can be formed on a substrate using a composition solution, similar to a photoresist composition, by spin coating or other methods. After forming the organic resist interlayer film by spin coating or other methods, it is desirable to bake it to evaporate the organic solvent. Ideally, the baking temperature should be between 80 and 400°C, and the baking time should be between 10 and 300 seconds.

[0274] An organic hard mask formed by a CVD method or an ALD method may be used instead of the above-mentioned organic resist intermediate film material.

[0275] [Silicon-Containing Film Formation Step]

[0276] In this step, before the resist pattern forming step, a silicon-containing film may be formed directly or indirectly on the substrate having the metal-containing film formed in the coating step.

[0277] The silicon-containing film can be formed by coating a silicon-containing film-forming composition, chemical vapor deposition (CVD), atomic layer deposition (ALD), etc. As for the method of forming a silicon-containing film by coating a silicon-containing film-forming composition, there can be mentioned a method such as curing the coating film formed by directly or indirectly applying the silicon-containing film-forming composition to the metal-containing film by exposing and / or heating it. As for commercial products of the above-mentioned silicon-containing film-forming composition, "SHB-A940" (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used. By chemical vapor deposition (CVD) or atomic layer deposition (ALD), a silicon oxide film, a silicon nitride film, a silicon nitride oxide film, or an amorphous silicon film can be formed.

[0278] [Cleaning steps]

[0279] In this step, the peripheral portion of the substrate is cleaned with a cleaning liquid. As the cleaning liquid, the cleaning liquid of the present invention can be preferably used.

[0280] The cleaning method is not particularly limited, and known cleaning methods in semiconductor manufacturing processes, such as edge bead removal and backside rinsing, can be employed. In the present invention, the step of cleaning a substrate having a metal-containing film formed thereon preferably includes applying the cleaning solution of the present invention along the periphery of the substrate to remove edge bead from the substrate (hereinafter sometimes referred to as "edge rinsing").

[0281] Representatively, such as Figure 1 As shown, first, the substrate 1 on which the metal-containing film 2 is formed is rotated at a predetermined speed ( Figure 1 Then, while the cleaning liquid 4 is ejected from the cleaning liquid ejection nozzle 3, the cleaning liquid ejection nozzle 3 is moved at a predetermined speed from the outer peripheral end of the rotating substrate 1 toward the center of the substrate 1 ( Figure 1 (B)). When the cleaning liquid ejection nozzle 3 has moved a predetermined distance, it stops moving and continues to eject the cleaning liquid 4 for a predetermined time. Thereafter, the ejection of the cleaning liquid 4 from the cleaning liquid ejection nozzle 3 is stopped and dried as needed, thereby completing the cleaning of the coating film end portion 2A ( Figure 1 (C)). The rotation speed of the substrate, the amount of cleaning liquid ejected per unit time, the moving speed and moving distance of the cleaning liquid ejection nozzle, the cleaning liquid ejection time after stopping the movement of the cleaning liquid ejection nozzle, etc. can be appropriately set according to the substrate size, the number, type and thickness of the films to be formed, and the cleaning area.

[0282] The number of times of edge rinsing is not particularly limited, and it can be performed 1 to 20 times. Furthermore, two or more cleaning liquids may be used for edge rinsing.

[0283] In edge rinsing, the cleaning liquid is preferably added dropwise in an amount of 0.05 to 50 ml, more preferably 0.075 to 40 ml, and even more preferably 0.1 to 30 ml.

[0284] After coating the substrate with the metal-containing film-forming composition, the cleaning step may be performed after or after the heating step. If the cleaning step is performed after the coating step without the heating step, it is preferably performed after the cleaning step.

[0285] The metal-containing film formed by the above steps is preferably a photoresist film or a resist underlayer film.

[0286] Furthermore, the present invention, Figure 2 As shown, the cleaning liquid can also be used to reprocess the metal-containing film 2 on the substrate 1 and reuse the substrate 1. The cleaning liquid spray nozzle 3 is moved to the center of the substrate 1 and the cleaning liquid 4 is sprayed onto the rotating substrate 1 at a predetermined time. Figure 2(D) to (E)). After that, the cleaning liquid 4 is stopped from being ejected from the cleaning liquid ejection nozzle 3 and dried as needed, thereby completing the cleaning ( Figure 2 The rotation speed of the substrate, the amount of cleaning liquid ejected per unit time, the ejection position of the cleaning liquid, etc. can be appropriately set according to the substrate size, the number, type and thickness of the films to be formed, and the cleaning area.

[0287] To evaluate the metal removal achieved by edge washing, the substrate can be inspected for residual metal. Suitable commercially available methods for evaluating trace metals generally include inductively coupled plasma mass spectrometry (ICP-MS). For substrate surface evaluation, vapor phase decomposition-inductively coupled plasma mass spectrometry (VPD-ICP-MS) can be used. This technique can determine the residual metal per unit area of ​​the wafer surface along the edge.

[0288] In the present invention, when the metal-containing film is based on Zr, the amount of residual Zr is 100×10 10 atoms / cm 2 The following is more ideal, 50×10 10 atoms / cm 2 The following is more ideal, 10×10 10 atoms / cm 2 The following is even better, 5×10 10 atoms / cm 2 The following are particularly ideal.

[0289] <Pattern Formation Method Using Metal-Containing Resist Underlayer Film>

[0290] In the resist pattern forming step, after the cleaning step, a resist pattern is formed directly or indirectly on the metal-containing film. Examples of methods for performing this step include methods using a resist composition, methods using nanoimprinting, and methods using a self-assembling composition. Indirectly forming the resist pattern on the metal-containing film may involve forming the resist pattern on the silicon-containing film, for example, when the semiconductor substrate manufacturing method includes the silicon-containing film forming step.

[0291] The following is an example of a method for directly or indirectly forming a resist pattern on the metal-containing film after the cleaning step and transferring the resist pattern to the substrate to be processed.

[0292] (2-layer resist process)

[0293] In the present invention, with respect to a pattern forming method performed using a two-layer resist process using a metal-containing film, a pattern forming method can be provided, which is characterized in that a metal-containing film is formed on a substrate to be processed using a metal-containing film-forming composition, a resist upper film is formed on the metal-containing film using a photoresist material, the resist upper film is subjected to pattern exposure, and then developed with a developer to form a pattern on the resist upper film, the resist upper film with the pattern formed is used as a mask, and the pattern is transferred to the metal-containing film by dry etching, the substrate to be processed is processed using the metal-containing film with the pattern formed as a mask, and a pattern is formed on the processed substrate.

[0294] The resist upper layer film in the above-mentioned two-layer resist process shows etching resistance to chlorine-based gases. Therefore, in the above-mentioned two-layer resist process, it is more ideal to use an etching gas mainly composed of chlorine-based gases to perform dry etching of the metal-containing film using the resist upper layer film as a mask.

[0295] In order to ensure adhesion with the resist upper layer film, an adhesive film may be formed between the resist upper layer film and the metal-containing film. The adhesive film may be an organic film or a silicon-containing film containing polysiloxane.

[0296] (3-layer resist process)

[0297] Furthermore, the present invention provides a pattern forming method for a three-layer resist process using a metal-containing film, characterized in that a metal-containing film is formed on a substrate to be processed using a metal-containing film-forming composition, an organic resist intermediate film is formed on the metal-containing film, a resist upper film is formed on the organic resist intermediate film using a photoresist material, the resist upper film is subjected to pattern exposure and then developed with a developer to form a pattern on the resist upper film, the pattern is transferred to the organic resist intermediate film by dry etching using the resist upper film with the pattern formed as a mask, the pattern is transferred to the metal-containing film by dry etching using the organic resist intermediate film with the pattern transferred as a mask, the substrate to be processed is processed using the metal-containing film with the pattern formed as a mask, and a pattern is formed on the substrate to be processed.

[0298] The organic resist intermediate film of the above-mentioned three-layer resist process shows etching resistance to chlorine-based gases. Therefore, in the above-mentioned three-layer resist process, it is more ideal to use an etching gas mainly composed of chlorine-based gases to perform dry etching of the metal-containing film using the organic resist intermediate film as a mask.

[0299] (4-layer resist process)

[0300] Furthermore, the present invention provides a pattern forming method using a four-layer resist process using a metal-containing film, characterized in that a metal-containing film is formed on a substrate to be processed using a metal-containing film-forming composition, an organic resist interlayer is formed on the metal-containing film, a silicon-containing film is formed on the organic resist interlayer, a resist upper layer is formed on the silicon-containing film using a photoresist material, the resist upper layer is subjected to pattern exposure, and then developed with a developer. A pattern is formed on the resist upper film, the resist upper film with the pattern is used as a mask, the pattern is transferred to the silicon-containing film by dry etching, the silicon-containing film with the pattern transferred is used as a mask, the pattern is transferred to the organic resist intermediate film by dry etching, the organic resist intermediate film with the pattern transferred is used as a mask, the pattern is transferred to the metal-containing film by dry etching, the metal-containing film with the pattern formed is used as a mask, the processed substrate is processed, and a pattern is formed on the processed substrate.

[0301] Here, use Figure 3 The pattern forming method using the four-layer resist process is described. First, a metal-containing film 2 ( Figure 3 (A)). Next, the cleaning liquid 4 is ejected from the cleaning liquid ejection nozzle 3 as described above to clean the metal-containing film 2 at the end of the substrate ( Figure 3 (B)). Thus, the cleaning of the coating film end portion 2A is completed ( Figure 3 (C)). Then, an organic resist intermediate film 7, a silicon-containing film 6, and a resist upper film 5 are formed on the metal-containing film 2 ( Figure 3 (D)). The exposed portion 8 of the resist upper film 5 is exposed to form a resist upper film pattern 5a ( Figure 3 (E) to (F)). Then, using the resist upper film pattern 5a as a mask, the pattern is transferred to the silicon-containing film 6 by dry etching to form a silicon-containing film pattern 6a ( Figure 3 (G)), and then forming an organic resist intermediate film pattern 7a and a metal-containing film pattern 2a ( Figure 3 (H)~(I)).

[0302] An inorganic hard mask can be formed as an inorganic hard mask intermediate film. In this case, a metal-containing film is formed at least on the workpiece using a metal-containing film-forming composition, an organic resist intermediate film is formed on the metal-containing film, an inorganic hard mask selected from silicon oxide film, silicon nitride film, and silicon oxynitride film is formed on the organic resist intermediate film, a photoresist composition is used on the inorganic hard mask to form a resist upper film, a circuit pattern is formed on the resist upper film, the inorganic hard mask is etched using the resist upper film with the pattern formed as a mask, the organic resist intermediate film is etched using the inorganic hard mask with the pattern formed as a mask, the metal-containing film is etched using the organic resist intermediate film with the pattern formed as a mask, and further, the workpiece is etched using the metal-containing film with the pattern formed as a mask to form a pattern on the workpiece, thereby forming a semiconductor device circuit pattern on the substrate.

[0303] As described above, when forming an inorganic hard mask on a metal-containing film, a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiON film) can be formed using methods such as CVD and ALD. For example, methods for forming a silicon nitride film are described in Japanese Patent Application Publication No. 2002-334869 and International Publication No. 2004 / 066377. The inorganic hard mask preferably has a thickness of 5 to 200 nm, more preferably 10 to 100 nm. Furthermore, SiON film, which is highly effective as an antireflective film, is most ideal for use as an inorganic hard mask. To maintain a substrate temperature of 300 to 500°C during SiON film formation, the metal-containing film must be able to withstand temperatures of 300 to 500°C. The metal-containing film-forming composition used in the present invention has high heat resistance and can withstand high temperatures of 300°C to 500°C, so it can be a combination of an inorganic hard mask formed by CVD or ALD and a metal-containing film formed by spin coating.

[0304] As described above, a photoresist film can be formed on an inorganic hard mask as a resist upper layer. Alternatively, an organic antireflective film (BARC) or adhesion film can be formed on the inorganic hard mask by spin coating, and a photoresist film formed thereon. In particular, when using a SiON film as an inorganic hard mask, the dual antireflective films of the SiON film and the BARC can suppress reflections even during immersion exposure with a high NA exceeding 1.0. Another advantage of forming a BARC is that it reduces smearing of the photoresist pattern directly above the SiON film.

[0305] In the above-mentioned pattern forming method, the resist upper layer film may be either positive-type or negative-type, and the same composition as a commonly used photoresist composition may be used.

[0306] When forming a photoresist composition by spin coating, a pre-bake is performed after the resist is applied, preferably at 60-180°C for 10-300 seconds. Exposure, post-exposure baking (PEB), and development are then performed according to conventional methods to obtain a resist pattern. The thickness of the resist top layer is not particularly limited, but is preferably 10-500 nm, particularly 20-400 nm.

[0307] Examples of exposure light include high-energy rays with a wavelength of 300 nm or less, specifically, excimer lasers of 248 nm, 193 nm, and 157 nm, and soft X-rays, electron beams, and X-rays of 3 to 20 nm.

[0308] The patterning method of the resist upper layer may be performed by optical lithography with a wavelength of 5 nm to 300 nm, direct writing with an electron beam, nanoimprinting, or a combination thereof. However, EUV light is most ideal in the present invention.

[0309] Furthermore, it is preferable that the development method in the pattern forming method be set to development using an alkali or an organic solvent.

[0310] Next, etching is performed using the resulting resist pattern as a mask. Etching of the silicon-containing resist interlayer and inorganic hard mask in the four-layer resist process is performed using a Freon-based gas and the upper resist pattern as a mask. This results in the formation of a silicon-containing resist interlayer pattern and an inorganic hard mask pattern.

[0311] Then, the obtained silicon-containing resist interlayer pattern and inorganic hard mask pattern are used as masks to perform etching of the organic resist interlayer film. The etching of the organic resist interlayer film is preferably performed using an etching gas mainly composed of an oxygen-based gas.

[0312] Then, the obtained organic resist interlayer film pattern is used as a mask to perform etching of the metal-containing film. The etching of the metal-containing film is preferably performed using an etching gas mainly composed of a chlorine-based gas.

[0313] Subsequent etching of the workpiece can also be performed using conventional methods. For example, if the workpiece is a SiO2, SiN, or silicon dioxide-based low-k dielectric film, etching is performed primarily using a Freon-based gas. When etching the substrate using a Freon-based gas, the silicon-containing resist interlayer pattern in the four-layer resist process is stripped simultaneously with the substrate processing.

[0314] In the present invention, the metal-containing film obtained from the metal-containing film-forming composition has a characteristic of being excellent in etching resistance when etching these workpieces.

[0315] Furthermore, the object to be processed (substrate to be processed) is not particularly limited, and substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, and Al, as well as substrates having a process layer formed thereon, can be used. The process layer can be a variety of low-k films such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, as well as their stopper films. Typically, a thickness of 50 to 10,000 nm, particularly 100 to 5,000 nm, can be formed. Furthermore, when forming the process layer, the substrate and the process layer are made of different materials.

[0316] [Example]

[0317] Hereinafter, the present invention will be described in detail with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to these descriptions.

[0318] <Preparation of cleaning solution>

[0319] Each cleaning solution was prepared by mixing the components in the ratio shown in Table 1.

[0320] [Table 1]

[0321]

[0322]

[0323] The first solvent used was the solvent shown in Table 2 below.

[0324] [Table 2]

[0325]

[0326] The second solvent used was the solvent shown in Table 3 below.

[0327] [Table 3]

[0328]

[0329] As the organic acid, the organic acids shown in Table 4 below were used.

[0330] [Table 4]

[0331] organic acids type G-1 Acetic acid G-2 Formic acid G-3 citric acid G-4 acrylic acid G-5 Propionic acid

[0332] Acetylacetone (Tokyo Chemical Industry Co., Ltd., P0052) was used as the chelating agent (c-1), and allyl acetoacetate (Tokyo Chemical Industry Co., Ltd., A1981) was used as the chelating agent (c-2).

[0333] <Preparation of Metal-Containing Film-Forming Composition>

[0334] [Synthesis Example of Metal Compound]

[0335] In the following synthesis examples, the following metal sources M: (M1) to (M3) and compound group H are used:

[0336] (H1)~(H3).

[0337] (M1): Ti(OBu)4: Tetrabutyl orthotitanate (Tokyo Chemical Industry Co., Ltd., B0742)

[0338] (M2): Hf(OBu)4: n-butoxyhafnium(IV) (Sigma-Aldrich Corp, 667943)

[0339] (M3): Zr(OBu)4: tetrabutoxyzirconium (IV) (80% by mass 1-butanol solution) (Tokyo Chemical Industry Co., Ltd., Z0016)

[0340] [Chemistry 4]

[0341]

[0342] [Synthesis Example 1: Synthesis of Metal-Containing Metal Compound for Film Formation (m-1)]

[0343] Under a nitrogen atmosphere, a solution of 54.5 g of n-butanol in 1.6 g of deionized water was added dropwise to 40.5 g of a n-butanol solution of 28.4 g of tetrabutyl orthotitanate (M1) while stirring at room temperature over a period of 2 hours. 11.2 g of the compound group (H1) was added to the obtained solution, and the mixture was stirred at room temperature for 30 minutes. After the solution was concentrated at 30°C under reduced pressure, it was heated to 60°C and continued to be heated under reduced pressure until no distillate appeared. After no distillate was observed, 69.0 g of a PGMEA / PGME (weight ratio 70 / 30) solution was added, and the mixture was heated at 40°C under reduced pressure until IPA no longer distilled, thereby obtaining a PGMEA / PGME solution of a metal compound (m-1) for forming a metal-containing film. The concentration of the components other than the solvent in the above solution was 17% by mass.

[0344] [Synthesis of Compounds (m-2) to (m-3)]

[0345] Compounds (m-2) to (m-3) shown in Table 5 were obtained under the same reaction conditions as in Synthesis Example 1 except that the metal source M and compound group H were used in the feed amounts shown in Table 5.

[0346] [Table 5]

[0347]

[0348] [Preparation of Compound (m-4)]

[0349] As the metal compound (m-4), tin(II) 2-ethylhexanoate (Tokyo Chemical Industry Co., Ltd., T3149) was used.

[0350] [Preparation of Metal-Containing Film-Forming Composition (MUL-1)]

[0351] The metal-containing film-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 6, and filtered with a 0.02 μm membrane filter to prepare a metal-containing film-forming composition (MUL-1).

[0352] [Preparation of Metal-Containing Film-Forming Compositions (MUL-2 to 4)]

[0353] Each solution was prepared in the same manner as in MUL-1 except that the types and contents of the components were set as shown in Table 6.

[0354] [Table 6]

[0355]

[0356] <Evaluation of Metal Cleaning Properties>

[0357] After applying the metal-containing film-forming composition (MUL-1-4) prepared above to a silicon substrate by spin coating, the cleaning liquid (MER-1-25, Comparative Examples MER-1-2) was ejected at a rate of 2 ml / s while the cleaning liquid ejection nozzle was moved 2 mm from the outer edge of the substrate toward the center of the substrate while rotating at 1500 rpm. The cleaning liquid was ejected at a rate of 2 ml / s from the position 2 mm from the outer edge of the substrate toward the center of the substrate for 10 seconds, and then the substrate was rotated at 1500 rpm for 30 seconds. The substrate was then heated at 450°C for 60 seconds to obtain an evaluation substrate A having a metal-containing film having an average thickness of 30 nm. The amount of residual metal (×10) at the outer edge (front and back regions 0.3 mm from the edge) of the obtained evaluation substrate A was measured using vapor phase decomposition-inductively coupled plasma mass spectrometry (VPD-ICP-MS). 10 atoms / cm 2 ).

[0358] Evaluation substrates B, each having a metal-containing film with an average thickness of 30 nm, were obtained by following the same procedure as for obtaining evaluation substrate A, except that OK73 diluent was used instead of the cleaning solution (MER-1 to 25). OK73 diluent is a mixed solvent of propylene glycol monomethyl ether and propylene glycol methyl ether acetate.

[0359] For metal cleaning performance, the amount of metal constituting the metal-containing film-forming metal compound detected on evaluation substrate A relative to evaluation substrate B was rated "A," 30% to 50% or more was rated "B," and 50% or more was rated "C." The results are shown in Table 7.

[0360] [Table 7]

[0361]

[0362]

[0363] As shown in Table 7, the cleaning solution of the present invention demonstrates superior metal cleaning performance compared to Comparative Examples 1-1 and 1-2, which used Comparative Examples MER-1 and MER-2. It is speculated that the cleaning solution of the present invention, containing a second solvent (A-2) with a normal boiling point of 160°C or higher and less than 500°C, suppresses drying of the cleaning solution, further improving the metal cleaning effect of the organic acid. Cleaning solutions containing chain carboxylates or chain ethers (Y-2-4) that do not contain hydroxyl groups as the second solvent exhibited superior metal removal performance. This is presumably because the use of an organic solvent that does not contain hydroxyl groups suppresses the esterification reaction of the acid in the cleaning solution, thereby preventing deterioration in the cleaning solution's metal removal performance. Furthermore, Examples 1-24 and 1-25, which used cleaning solutions MER-24 and MER-25 containing compounds (c-1) and (c-2) containing a β-diketone structure as a chelating agent, exhibited superior cleaning performance compared to Examples 1-9 and 1-10, which used cleaning solutions MER-9 and MER-10 that did not contain a chelating agent.

[0364] <Discharge Stability>

[0365] Mixed solutions were prepared by mixing equal amounts of the cleaning solutions (MER-1 to 25) prepared above with metal-containing film-forming compositions (MUL-1 to 4), a resist underlayer film-forming composition (SOC-1), a silicon-containing film-forming composition (SOG-1), and a photoresist composition (PR-1). The presence of precipitates and turbidity was visually inspected after standing at 23°C for one week. For the stability of the effluent, the presence of precipitates and turbidity after standing at 23°C for one week was rated "good," while the presence of precipitates or turbidity was rated "poor." The results are shown in Table 12.

[0366] The following materials were used for the resist underlayer film forming composition (SOC-1), the silicon-containing film forming composition (SOG-1), and the photoresist composition (PR-1).

[0367] As for the composition for forming an anti-etching agent underlayer film (SOC-1), the polymer shown as the organic underlayer film polymer (SOP1) and 0.1% by mass of FC-4430 (produced by Sumitomo 3M Co., Ltd.) were dissolved in an organic solvent in the proportions shown in Table 8, and filtered with a filter material made of fluororesin with a pore size of 0.2 μm to prepare the composition for forming an anti-etching agent underlayer film (SOC-1).

[0368] [Table 8]

[0369]

[0370] Table 9 shows the structural formula of the organic underlayer membrane polymer (SOP1) used.

[0371] [Table 9]

[0372]

[0373] The silicon-containing film-forming composition (SOG-1) was prepared by dissolving a polymer represented by a silicon-containing intermediate film polymer (SiP1) and a thermal cross-linking catalyst (CAT1) in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) in the proportions shown in Table 10, and filtering the mixture through a fluororesin filter material having a pore size of 0.1 μm.

[0374] [Table 10]

[0375]

[0376] The structural formulas of the silicon-containing interlayer polymer (SiP1) and the thermal crosslinking catalyst (CAT1) used are shown below.

[0377] [Chemistry 5]

[0378]

[0379] The photoresist composition (PR-1) was prepared by dissolving the following polymer, quencher, sensitizer, and surfactant in an organic solvent containing 0.25% by mass of FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) at the ratios shown in Table 11. The mixture was then filtered through a fluororesin filter having a pore size of 0.1 μm.

[0380] [Chemistry 6]

[0381]

[0382] [Chemistry 7]

[0383]

[0384] Surfactant: FC-4430 manufactured by 3M

[0385] [Table 11]

[0386]

[0387] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) CyHO (cyclohexanone)

[0388] PGME (propylene glycol monomethyl ether)

[0389] [Table 12]

[0390]

[0391]

[0392] As shown in the results of Table 12, it can be understood that the cleaning liquid of the present invention is excellent in discharge liquid stability.

[0393] <Evaluation of bulge height>

[0394] like Figure 4 As shown in FIG, the metal-containing film-forming composition 2' (MUL-1 to 4) prepared above was applied to the silicon substrate 1 by spin coating ( Figure 4 (A)), while rotating at 1500 rpm, the cleaning liquid ejection nozzle 3 is moved to a position 2 mm from the outer peripheral end of the substrate toward the center of the substrate, and the cleaning liquid 4 (MER-1 to 25, comparative example MER-1 to 2) is ejected at a jet volume of 2 ml / s ( Figure 4 (B)), the cleaning liquid is ejected at a rate of 2 ml / s for 10 seconds at a position moved 2 mm from the outer edge of the substrate toward the center of the substrate ( Figure 4 (C)), the substrate was rotated at 1500 rpm for 30 seconds. Then, the substrate was heated at 450°C for 60 seconds to obtain an evaluation substrate A on which a metal-containing film having an average thickness of 30 nm was formed. Then, a stylus-type film thickness meter (device name "Alpha Step", manufactured by KLA-Tencor) was used to measure the height (hump) of the coating film end 2A near the boundary with the film removal area. Figure 4 (D) ridge 8).

[0395] Evaluation substrates B having respective metal-containing films with an average thickness of 30 nm formed thereon were obtained in the same manner as in the procedure for obtaining evaluation substrate A, except that OK73 diluent was used instead of the cleaning liquid (MER-1 to 25).

[0396] The case where the protrusion height of the evaluation substrate A was less than 50% of the evaluation substrate B was designated "A", the case where it was 50 to 80% was designated "B", and the case where it exceeded 80% was designated "C".

[0397] [Table 13]

[0398] Example cleaning fluid Height of bulge Example 3-1 MER-1 A Example 3-2 MER-2 A Example 3-3 MER-3 A Examples 3-4 MER-4 A Examples 3-5 MER-5 A Examples 3-6 MER-6 A Examples 3-7 MER-7 A Examples 3-8 MER-8 A Examples 3-9 MER-9 A Examples 3-10 MER-10 B Example 3-11 MER-11 A Examples 3-12 MER-12 A Example 3-13 MER-13 A Examples 3-14 MER-14 A Examples 3-15 MER-15 B Example 3-16 MER-16 A Example 3-17 MER-17 A Example 3-18 MER-18 A Example 3-19 MER-19 A Example 3-20 MER-20 A Example 3-21 MER-21 A Example 3-22 MER-22 A Example 3-23 MER-23 A Example 3-24 MER-24 A Example 3-25 MER-25 B Comparative Example 1-1 Comparative Example MER-1 C Comparative Example 1-2 Comparative Example MER-2 B

[0399] As shown in the results of Table 13, it can be understood that the cleaning liquid of the present invention can suppress the height of the ridges compared to the OK73 diluent. In particular, the cleaning liquids containing the second solvents (Y-1) to (Y-6) with high surface tension (such as MER-1 to 9) show excellent ridge suppression. On the other hand, no improvement in ridges was found in the comparative example MER-1 that does not contain a second solvent. The comparative example MER-2 that contains the second solvent (Y-1) but does not contain an organic acid obtained a poor result in ridge suppression compared to MER-5 that contains an organic acid. In other words, it is believed that by including an organic acid, the compatibility with the metal-containing film is improved, and the ridge suppression is improved. It is believed that the cleaning liquid of the present invention, in addition to the organic acid, also contains the second solvent with a normal boiling point of 160°C or more and less than 500°C, so a multiplying effect is exerted, and excellent ridge suppression is exhibited.

[0400] As described above, the cleaning liquid of the present invention comprises (A) a solvent and (B) an organic acid, wherein the solvent (A) comprises at least one first solvent (A-1) having a normal boiling point of less than 160°C and at least one second solvent (A-2) having a normal boiling point of 160°C or higher and less than 500°C. This cleaning liquid can provide excellent cleaning properties, ridge suppression properties, and discharge stability for removing metal-containing films formed on the peripheral edge of a substrate when a metal-containing film-forming composition is applied to the substrate. Substrate cleaning methods and metal-containing film-forming methods using the cleaning liquid exhibit excellent cleaning properties, ridge suppression properties, and discharge stability, enabling efficient formation of a desired resist underlayer film. These cleaning liquids are ideally suited for use in, for example, the manufacture of semiconductor devices, which are expected to continue to become increasingly miniaturized.

[0401] This specification includes the following inventions.

[0402] [1]: A cleaning liquid containing a metal film-forming composition, characterized by:

[0403] A cleaning solution comprising (A) a solvent and (B) an organic acid,

[0404] The solvent (A) includes at least one first solvent (A-1) having a normal boiling point of less than 160°C and at least one second solvent (A-2) having a normal boiling point of 160°C or higher and less than 500°C.

[0405] [2]: The cleaning solution of [1], wherein the second solvent (A-2) is a chain ester, a chain ether, or a combination thereof.

[0406] [3]: The cleaning solution of [2], wherein the ester is a carboxylic acid ester.

[0407] [4]: The cleaning solution of [2] or [3], wherein the ether is (poly)alkylene glycol dibenzyl ether or (poly)phenylene ether.

[0408] [5]: The cleaning solution according to any one of [1] to [4], wherein the surface tension of the second solvent (A-2) is 29.0 mN / m or greater.

[0409] [6]: A cleaning solution as described in any one of [1] to [5], wherein in the solvent (A), the content of the first solvent (A-1) is not less than 30 mass % and not more than 98 mass %, and the content of the second solvent (A-2) is not less than 2 mass % and not more than 70 mass %.

[0410] [7]: The cleaning solution according to any one of [1] to [6], wherein the organic acid (B) is a carboxylic acid.

[0411] [8]: The cleaning solution according to any one of [1] to [7], wherein the content of the organic acid (B) is 1 to 70% by mass relative to the total mass of the cleaning solution.

[0412] [9]: The cleaning solution according to any one of [1] to [8], further comprising a compound having β-diketone as (C) the chelating agent.

[0413]

[10] : The cleaning solution of [9], wherein the content of the (C) chelating agent is 0.1 to 10% by mass relative to the total mass of the cleaning solution.

[0414]

[11] :A method for cleaning a substrate, characterized by comprising the following steps:

[0415] On a substrate directly or indirectly coated with a metal-containing film-forming composition, the metal-containing film-forming composition at the peripheral edge of the substrate is cleaned by using the cleaning solution described in any one of [1] to

[10] .

[0416]

[12] : A method for forming a metal-containing film, characterized by:

[0417] The following steps are involved:

[0418] directly or indirectly coating a metal-containing film-forming composition on a substrate,

[0419] Cleaning the metal film-forming composition on the peripheral portion of the substrate with the cleaning solution described in any one of [1] to

[10] ;

[0420] The metal-containing film-forming composition is set to contain a metal compound and a solvent.

[0421] The present invention is not limited to the above-described embodiments, which are merely examples, and any device having substantially the same configuration and exhibiting the same functions and effects as the technical concept described in the claims of the present invention is encompassed within the technical scope of the present invention.

[0422] Description of Reference Numerals

[0423] 1: Processed substrate (substrate, silicon substrate)

[0424] 2: Metal-containing film

[0425] 2': Metal-containing film-forming composition

[0426] 2A: Coating film end

[0427] 2a: Metal-containing film pattern

[0428] 3: Cleaning fluid spray nozzle

[0429] 4: Cleaning fluid

[0430] 5: Resist upper film

[0431] 5a: Resist upper film pattern

[0432] 6: Silicon-containing film

[0433] 6a: Silicon-containing film pattern

[0434] 7: Organic resist interlayer

[0435] 7a: Organic resist interlayer pattern

[0436] 8: Exposure part

[0437] Bump 8: Bump height.

Claims

1. A cleaning liquid comprising a metal film-forming composition, characterized by: yes A cleaning solution comprising (A) a solvent and (B) an organic acid, The solvent (A) comprises at least one first solvent (A-1) having a normal boiling point of less than 160°C and at least one second solvent (A-2) having a normal boiling point of 160°C or higher and less than 500°C.

2. The cleaning solution according to claim 1, wherein The second solvent (A-2) is a chain ester, a chain ether, or a combination thereof.

3. The cleaning solution according to claim 2, wherein The esters are carboxylic acid esters.

4. The cleaning solution according to claim 2, wherein The ethers are (poly)alkylene glycol dibenzyl ethers or (poly)phenylene ethers. The cleaning solution according to claim 1 , wherein: The surface tension of the second solvent (A-2) is 29.0 mN / m or more. The cleaning solution according to claim 1 , wherein: In the solvent (A), the content of the first solvent (A-1) is 30% by mass or more and 98% by mass or less, and the content of the second solvent (A-2) is 2% by mass or more and 70% by mass or less.

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

8. The cleaning solution according to claim 1, wherein The content of the organic acid (B) is 1 to 70% by mass based on the total mass of the cleaning liquid.

9. The cleaning solution according to claim 1, wherein The cleaning solution further contains a compound having β-diketone as (C) a chelating agent.

10. The cleaning solution according to claim 9, wherein The content of the (C) chelating agent is 0.1 to 10% by mass based on the total mass of the cleaning liquid.

11. A method for cleaning a substrate, comprising the following steps: On a substrate directly or indirectly coated with a metal-containing film-forming composition, the metal-containing film-forming composition at a peripheral portion of the substrate is cleaned using the cleaning solution according to any one of claims 1 to 10.

12. A method for forming a metal-containing film, characterized by: The following steps are involved: directly or indirectly coating a metal-containing film-forming composition on a substrate, cleaning the metal film-forming composition on the peripheral portion of the substrate with the cleaning solution according to any one of claims 1 to 10; The metal-containing film-forming composition is set to contain a metal compound and a solvent.

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