Surface treatment agent, surface treatment method, and region-selective film formation method on substrate surface

Abstract

To provide a surface treatment agent having good properties such as substrate selectivity, desorption, etc. in a method for treating a substrate having a surface containing two or more regions having different materials from each other, a surface treatment method using the surface treatment agent, and a region-selective film formation method for a substrate surface to which the surface treatment method is applied.SOLUTION: A surface treatment agent used to treat a substrate having a surface containing two or more regions of different materials includes a compound (H) represented by the following general formula (H-1) (in the formula, R1 is a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched chain fluorinated alkyl group having 1 to 30 carbon atoms, an aromatic hydrocarbon group or a cycloalkyl group having 3 to 12 carbon atoms. R2 is a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a surface treatment agent, a surface treatment method, and a method for selectively forming a film on a region of a substrate surface. [Background technology]

[0002] In recent years, there has been an increasing trend toward higher integration and miniaturization of semiconductor devices, and the organic patterns used as masks and the inorganic patterns produced by etching processes have become finer, requiring film thickness control at the atomic layer level. Atomic layer deposition (ALD) is a method for forming thin films on a substrate at the atomic layer level. The ALD method is known to have both high step coverage and film thickness controllability compared to the general CVD (Chemical Vapor Deposition) method.

[0003] The ALD method is a thin-film formation technology in which two types of gases, the main components of which are the elements that make up the film to be formed, are alternately supplied onto a substrate, and a thin film is formed on the substrate in atomic layer units by repeating this process multiple times to form a film of the desired thickness. In the ALD method, while the source gas is being supplied, only one or a few layers of the source gas components are adsorbed onto the substrate surface, and excess source gas does not contribute to growth; this utilizes the growth's self-limiting function. For example, when forming an Al2O3 film on a substrate, a source gas consisting of TMA (TriMethy1 Aluminum) and an oxidizing gas containing O are used. When forming a nitride film on a substrate, a nitriding gas is used instead of the oxidizing gas.

[0004] In recent years, attempts have been made to form a film selectively in a region on a substrate surface using the ALD method (see Non-Patent Documents 1 and 2). Accordingly, there is a demand for substrates whose surfaces are modified in a selective manner so that they can be suitably applied to a method for selectively depositing a film on a substrate by the ALD method. In the film formation method, the use of the ALD method is expected to enable film thickness control at the atomic layer level in patterning, step coverage, and miniaturization. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] J.Phys.Chem. C 2014,118,10957-10962 [Non-Patent Document 2] ACS NANO Vol.9,No.9,8710-8717(2015) Summary of the Invention [Problem to be solved by the invention]

[0006] In the methods described in Non-Patent Documents 1 and 2, phosphonic acid is used as a material (hereinafter referred to as "SAM agent") that forms a self-assembled monolayer that is applied to a region-selective film formation method on a substrate by the ALD method. Phosphonic acid has high heat resistance, but has low desorption property from the substrate, and phosphorus element remains on the substrate surface, which may hinder subsequent atomic deposition in the ALD method. In addition, when phosphonic acid is used as a SAM agent, it shows selectivity to a specific substrate, which may limit the types of substrates to which the ALD method can be applied.

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a surface treatment agent having good properties such as substrate selectivity and releasability in a method for treating a substrate having a surface including two or more regions made of different materials, a surface treatment method using the surface treatment agent, and a method for region-selectively forming a film on a substrate surface by applying the surface treatment method. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs the following configuration.

[0009] A first aspect of the present invention is a surface treatment agent used for treating a substrate having a surface including two or more regions made of different materials, the surface treatment agent comprising a compound (H) represented by the following general formula (H-1):

[0010] [ka] [In the formula, R 1 R is a linear or branched alkyl group having 1 to 30 carbon atoms which may have a substituent, a linear or branched fluorinated alkyl group having 1 to 30 carbon atoms which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a cycloalkyl group having 3 to 12 carbon atoms which may have a substituent. 2 represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms which may have a substituent, or a cycloalkyl group having 3 to 12 carbon atoms which may have a substituent.]

[0011] A second aspect of the present invention is a surface treatment method for a substrate having a surface including two or more regions made of different materials, the surface treatment method comprising exposing the surface to the surface treatment agent of the first aspect.

[0012] A third aspect of the present invention is a method for selectively depositing a film on a surface of a substrate, comprising treating the surface of the substrate by the surface treatment method of the second aspect and forming a film on the surface-treated surface of the substrate by atomic layer deposition, wherein the deposition amount of material of the film is varied selectively in each area. Effect of the Invention

[0013] According to the present invention, in a method for treating a substrate having a surface including two or more regions made of different materials, it is possible to provide a surface treatment agent having good properties such as substrate selectivity and releasability, a surface treatment method using the surface treatment agent, and a method for region-selective film formation on a substrate surface to which the surface treatment method is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] <First aspect: Surface treatment agent> The surface treatment agent according to the first aspect of the present invention is a surface treatment agent used for treating a substrate having a surface including two or more regions made of different materials (hereinafter, may be simply referred to as the "surface to be treated").

[0015] In this embodiment, from the viewpoint of ease of application to the method of region-selectively forming a film on a substrate surface, it is preferable that at least one region of the two or more regions of the treated surface contains a metal surface.

[0016] In this embodiment, when the treated surface includes two regions, the treated surface includes a first region and a second region that is made of a different material from the first region and is adjacent to the first region. In this case, the "adjacent regions" are the first region and the second region. Here, each of the first region and the second region may or may not be divided into a plurality of regions.

[0017] In this embodiment, when the treated surface includes three or more regions, the treated surface includes a first region, a second region that is made of a material different from that of the first region and adjacent to the first region, and a third region that is made of a material different from that of the second region and adjacent to the second region. In this case, the "adjacent regions" may be the first region and the second region (i.e., adjacent regions), or the first region and the third region (i.e., adjacent regions). In addition, if the first region and the third region are made of the same material, the "adjacent regions" are the first region and the second region, or the second region and the third region (i.e., adjacent regions). Here, each of the first region, the second region, and the third region may or may not be divided into a plurality of regions. In this embodiment, the same concept can be applied to the case where the treated surface includes a fourth or more regions. The upper limit of the number of regions made of different materials is not particularly limited as long as the effects of the present invention are not impaired, and is, for example, 7 or less or 6 or less, and typically 5 or less.

[0018] The surface treatment agent of this embodiment contains a compound (H) represented by the following general formula (H-1):

[0019] [ka] [In the formula, R 1 R is a linear or branched alkyl group having 1 to 30 carbon atoms which may have a substituent, a linear or branched fluorinated alkyl group having 1 to 30 carbon atoms which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a cycloalkyl group having 3 to 12 carbon atoms which may have a substituent. 2 represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms which may have a substituent, or a cycloalkyl group having 3 to 12 carbon atoms which may have a substituent.]

[0020] In the formula (H-1), R 1 In the linear or branched alkyl group having 1 to 30 carbon atoms, the number of carbon atoms is preferably 5 to 25, more preferably 6 to 22, and further preferably 7 to 20. R 1 Specific examples of the linear or branched alkyl group having 1 to 30 carbon atoms in the formula (I) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicosyl group, a docosyl group, and the isomers of the above-mentioned alkyl groups.

[0021] In the formula (H-1), R 1 Examples of the linear or branched fluorinated alkyl group having 1 to 30 carbon atoms in the formula (I) include groups in which some or all of the hydrogen atoms of the linear or branched alkyl group having 1 to 30 carbon atoms have been substituted with fluorine atoms.

[0022] R 1The linear or branched alkyl group having 1 to 30 carbon atoms or the linear or branched fluorinated alkyl group having 1 to 30 carbon atoms in the formula (1) may have a substituent. Examples of the substituent include a hydroxy group, a carboxy group, a halogen atom (such as a fluorine atom, a chlorine atom, or a bromine atom), an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), or an alkyloxycarbonyl group.

[0023] R 1 Examples of the aromatic hydrocarbon group in R include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, etc. Among these, the aromatic hydrocarbon group in R which may have a substituent is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group.

[0024] R 1 The aromatic hydrocarbon group in may have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, or a nitro group.

[0025] In the formula (H-1), R 1 Examples of the cycloalkyl group having 3 to 12 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group.

[0026] R 1 The cycloalkyl group having 3 to 12 carbon atoms in the formula (I) may have a substituent. Examples of the substituent include an alkyl group, a hydroxy group, a carboxy group, a halogen atom (such as a fluorine atom, a chlorine atom, or a bromine atom), an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), or an alkyloxycarbonyl group.

[0027] Among the above, R 1 As the alkyl group, a linear or branched alkyl group having 1 to 30 carbon atoms which may have a substituent or an aromatic hydrocarbon group which may have a substituent is preferable, and from the viewpoint of application to a method for treating a substrate having a surface including two or more regions made of different materials, a linear or branched alkyl group having 5 to 25 carbon atoms is more preferable.

[0028] In the formula (H-1), R 2 Examples of the linear or branched alkyl group having 1 to 8 carbon atoms in the formula include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and each isomer of the above-mentioned alkyl groups.

[0029] R 2 The linear or branched alkyl group having 1 to 8 carbon atoms in the formula (1) may have a substituent. Examples of the substituent include a hydroxy group, a carboxy group, a halogen atom (such as a fluorine atom, a chlorine atom, or a bromine atom), an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), or an alkyloxycarbonyl group.

[0030] In the formula (H-1), R 2 As the cycloalkyl group having 3 to 12 carbon atoms, R 1 Examples include the same cycloalkyl groups having 3 to 12 carbon atoms as those in the above.

[0031] Among the above, R 2 is preferably a hydrogen atom.

[0032] In the present embodiment, the compound (H) may be used alone or in combination of two or more kinds. In the surface treatment agent according to this embodiment, the content of compound (H) is preferably from 1 ppm to 20 mass %, more preferably from 10 ppm to 15 mass %, and even more preferably from 100 ppm to 10 mass %, relative to the total mass of the surface treatment agent. When the content of compound (H) is within the above-mentioned preferred range, various properties (heat resistance, desorption property, etc.) required in the method for treating a substrate having a surface including two or more regions made of different materials are likely to be good.

[0033] ·water The surface treatment agent according to the present embodiment may contain water in order to further improve water repellency. The water may contain trace components that are inevitably mixed in. The water used in the surface treatment agent according to the present embodiment is preferably water that has been subjected to a purification treatment, such as distilled water, ion-exchanged water, or ultrapure water, and more preferably ultrapure water that is generally used in semiconductor manufacturing. In the surface treatment agent according to this embodiment, the content of water, when included, is preferably from 0.01 to 25 mass %, more preferably from 0.03 to 20 mass %, and even more preferably from 0.05 to 15 mass %. In the method for treating a substrate having a surface including two or more regions made of different materials, when at least one of the regions contains a metal surface, the compound (H) is easily adsorbed to the region containing the metal surface, and the selectivity of the surface treatment agent for the region containing the metal surface is easily improved by the content of water being within the above-mentioned preferred range. Also, the water repellency of the surface treatment agent is easily improved.

[0034] ·solvent In the present embodiment, the surface treatment agent preferably has each component dissolved in a solvent. When the surface treatment agent contains a solvent, it becomes easy to perform surface treatment of the substrate by a dipping method, a spin coating method, or the like.

[0035] Specific examples of the solvent include sulfoxides such as dimethyl sulfoxide; sulfones such as dimethyl sulfone, diethyl sulfone, bis(2-hydroxyethyl) sulfone, and tetramethylene sulfone; amides such as N,N-dimethylformamide, N-methylformamide, N,N-dimethylacetamide, N-methylacetamide, and N,N-diethylacetamide; lactams such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, and N-hydroxyethyl-2-pyrrolidone; imidazolidinones such as 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, and 1,3-diisopropyl-2-imidazolidinone; dialkyl glycol ethers such as dimethyl glycol, dimethyl diglycol, dimethyl triglycol, methyl ethyl diglycol, diethyl glycol, and triethylene glycol butyl methyl ether; methanol, ethanol, monoalcohol solvents such as n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, 3-methyl-3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-pentadecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, and cresol;(poly)alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, and tripropylene glycol monoethyl ether; (Poly)alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; other ethers such as dimethyl ether, diethyl ether, methyl ethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisoamyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, and tetrahydrofuran; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, and 3-heptanone; alkyl esters of lactate such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate;Ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxy-1-butyl acetate, 3-methyl-3-methoxybutylpropionate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-pentyl acetate, n-hexyl acetate, n-heptyl acetate, n-octyl acetate, n-pentyl formate, i-pentyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, methyl n-octanoate, methyl decanoate, methyl pyruvate, ethyl pyruvate, Other esters such as n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl 2-oxobutanoate, dimethyl adipate, and propylene glycol diacetate; lactones such as propylolactone, γ-butyrolactone, and 6-pentyrolactone; linear, branched, or cyclic aliphatic hydrocarbons such as n-hexane, n-heptane, n-octane, n-nonane, methyloctane, n-decane, n-vindecane, n-dodecane, 2,2,4,6,6-pentamethylheptane, 2,2,4,4,6,8,8-heptamethylnonane, cyclohexane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene, 1,3,5-trimethylbenzene, and naphthalene; terpenes such as p-menthane, diphenylmenthane, limonene, terpinene, bornane, norbornane, and pinane; and the like.

[0036] Among these, the solvent is preferably 3-methyl-3-methoxy-1-butyl acetate, ethyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, isopropanol or methyl ethyl ketone, and more preferably propylene glycol monomethyl ether.

[0037] Furthermore, since the surface treatment agent according to the present embodiment has high selectivity to regions including metal surfaces, it can be suitably applied to region-selective film formation on substrate surfaces using the ALD method.

[0038] <Second aspect: Surface treatment method> A surface treatment method for a substrate having a surface including two or more regions made of different materials, comprising exposing the surface to the surface treatment agent of the first aspect. In the surface treatment method according to the present embodiment, the surface includes two or more regions, and adjacent regions among the two or more regions are made of different materials, and adjacent regions among the two or more regions are made to have different contact angles by a reaction between the compound (H) and the two or more regions. In this embodiment, from the viewpoint of ease of application to a method for region-selectively forming a film on a substrate surface, it is preferable that at least one of the two or more regions contains a metal surface.

[0039] In this embodiment, the "substrate" to be surface-treated is exemplified by substrates used for manufacturing semiconductor devices, such as silicon (Si) substrates, silicon nitride (SiN) substrates, silicon oxide (Ox) substrates, tungsten (W) substrates, cobalt (Co) substrates, titanium nitride (TiN) substrates, tantalum nitride (TaN) substrates, germanium (Ge) substrates, silicon germanium (SiGe) substrates, aluminum (Al) substrates, nickel (Ni) substrates, ruthenium (Ru) substrates, copper (Cu) substrates, etc. The "surface of the substrate" includes the surface of the substrate itself, as well as the surfaces of inorganic and organic patterns provided on the substrate, and the surfaces of unpatterned inorganic or organic layers.

[0040] Examples of inorganic patterns provided on a substrate include a pattern formed by etching the surface of an inorganic layer present on a substrate using a photoresist method, preparing a mask, and then performing an etching process. Examples of inorganic layers include the substrate itself, as well as oxide films of elements constituting the substrate, and inorganic films or layers formed on the substrate surface, such as SiN, Ox, W, Co, TiN, TaN, Ge, SiGe, Al, Al2O3, Ni, Ru, and Cu. Such films or layers are not particularly limited, but examples thereof include inorganic films or layers formed during the manufacturing process of semiconductor devices.

[0041] Examples of organic patterns provided on a substrate include resin patterns formed on a substrate by a photolithography method using photoresist or the like. Such organic patterns can be formed, for example, by forming an organic layer, which is a photoresist film, on a substrate, exposing the organic layer through a photomask, and developing it. The organic layer may be an organic layer provided on the surface of the substrate itself, or on the surface of a laminated film provided on the substrate. Examples of such organic layers are not particularly limited, but include organic films provided for etching and forming masks in the process of creating a semiconductor device.

[0042] (Substrate surface includes two regions) In the surface treatment method according to the second aspect, the substrate surface includes two or more regions, and adjacent regions among the two or more regions are made of different materials.

[0043] Among the two or more regions, the region that tends to have a higher water contact angle (preferably a lower surface free energy) than the other region includes a region that contains at least one selected from the group consisting of W, Co, Al, Al2O3, Ni, Ru, Cu, TiN, and TaN. Among the two or more regions, the region that tends to have a smaller water contact angle (preferably, a higher surface free energy) than the other region includes a region that contains at least one selected from the group consisting of Si, Al2O3, SiN, Ox, TiN, TaN, Ge, and SiGe.

[0044] In this embodiment, when the substrate surface includes two regions, the substrate surface includes a first region and a second region that is made of a different material from the first region and is adjacent to the first region. In this case, the "adjacent regions" are the first region and the second region. Here, each of the first region and the second region may or may not be divided into a plurality of regions.

[0045] Examples of the first region and the second region include a mode in which the surface of the substrate itself is the first region and the surface of an inorganic layer formed on the surface of the substrate is the second region, a mode in which the surface of a first inorganic layer formed on the surface of the substrate is the first region and the surface of a second inorganic layer formed on the surface of the substrate is the second region, etc. Note that modes in which an organic layer is formed instead of forming these inorganic layers can also be mentioned.

[0046] As an embodiment in which the surface of the substrate itself is the first region and the surface of an inorganic layer formed on the surface of the substrate is the second region, from the viewpoint of selectively improving hydrophobicity and improving the difference in water contact angle between two or more adjacent regions on the substrate surface made of different materials, a preferred embodiment is one in which the surface of at least one substrate selected from the group consisting of a Si substrate, a SiN substrate, an Ox substrate, a TiN substrate, a TaN substrate, a Ge substrate, and a SiGe substrate is the first region, and the surface of an inorganic layer containing at least one material selected from the group consisting of W, Co, Al, Ni, Ru, Cu, TiN, and TaN formed on the surface of the substrate is the second region.

[0047] In addition, as an embodiment in which the surface of a first inorganic layer formed on the surface of a substrate is the first region and the surface of a second inorganic layer formed on the surface of a substrate is the second region, from the viewpoint of selectively improving hydrophobicity and improving the difference in water contact angle between two or more adjacent regions on the substrate surface made of different materials, a preferred embodiment is one in which the surface of a first inorganic layer formed on the surface of an arbitrary substrate (e.g., a Si substrate) and containing at least one selected from the group consisting of SiN, Ox, TiN, TaN, Ge, and SiGe is the first region, and the surface of a second inorganic layer formed on the surface of the substrate and containing at least one selected from the group consisting of W, Co, Al, Ni, Ru, Cu, TiN, and TaN is the second region.

[0048] (Substrate surface includes three or more regions) In this embodiment, when the substrate surface includes three or more regions, the substrate surface includes a first region, a second region made of a material different from that of the first region and adjacent to the first region, and a third region made of a material different from that of the second region and adjacent to the second region. In this case, the "adjacent regions" may be the first region and the second region (i.e., adjacent regions), or the first region and the third region (i.e., adjacent regions). In addition, if the first region and the third region are made of the same material, the "adjacent regions" are the first region and the second region, or the second region and the third region (i.e., adjacent regions). Here, each of the first region, the second region, and the third region may or may not be divided into a plurality of regions. Examples of the first region, the second region, and the third region include, for example, a mode in which the surface of the substrate itself is the first region, the surface of the first inorganic layer formed on the surface of the substrate is the second region, and the surface of the second inorganic layer formed on the surface of the substrate is the third region. Note that, in place of forming these inorganic layers, an organic layer may be formed. Also, a mode in which both an inorganic layer and an organic layer are included, such as one in which only one of the second inorganic layer and the third inorganic layer is changed to an organic layer, may be included. From the viewpoint of selectively improving the hydrophobicity between two or more adjacent regions made of different materials on the substrate surface and improving the difference in water contact angle, a preferred embodiment is one in which the surface of any substrate (e.g., a Si substrate) itself is the first region, the surface of a first inorganic layer formed on the substrate surface and containing at least one selected from the group consisting of SiN, Ox, TiN, TaN, Ge, and SiGe is the second region, and the surface of a second inorganic layer formed on the substrate surface and containing at least one selected from the group consisting of W, Co, Al, Ni, Ru, Cu, TiN, and TaN is the third region. In this embodiment, the same concept can be applied to the case where the substrate surface includes a fourth or more regions. The upper limit of the number of regions made of different materials is not particularly limited as long as the effects of the present invention are not impaired, and is, for example, 7 or less or 6 or less, and typically 5 or less.

[0049] (exposure) Examples of a method for exposing the surface of a substrate to a surface treatment agent include a method in which a surface treatment agent which may contain a solvent (typically a liquid surface treatment agent) is applied (e.g., coated) to the surface of the substrate by means of, for example, an immersion method, or a coating method such as a spin coating method, a roll coating method, or a doctor blade method. The exposure temperature is, for example, 10°C or higher and 90°C or lower, preferably 20°C or higher and 80°C or lower, more preferably 20°C or higher and 70°C or lower, and even more preferably 20°C or higher and 65°C or lower. The exposure time is preferably 20 seconds or more, more preferably 30 seconds or more, and even more preferably 45 seconds or more, from the viewpoint of selectively improving hydrophobicity between two or more adjacent regions made of different materials on the substrate surface. There is no particular upper limit to the exposure time, but it is preferably, for example, 2 hours or less, more preferably 1.5 hours or less, and even more preferably 1.2 hours or less. After the exposure, washing (for example, washing with water, rinsing with an activator, etc.) and / or drying (washing with nitrogen blower, etc.) may be performed as necessary. For example, when cleaning the surface of a substrate having an inorganic or organic pattern with a cleaning liquid, the cleaning liquid that has been conventionally used for cleaning inorganic or organic patterns can be used as is. For inorganic patterns, examples of the cleaning liquid include SPM (sulfuric acid / hydrogen peroxide solution) and APM (ammonia / hydrogen peroxide solution), and for organic patterns, examples of the cleaning liquid include water and activator rinse. Furthermore, the treated substrate after drying may be additionally subjected to a heat treatment at 100° C. or more and 300° C. or less, if necessary.

[0050] By the above exposure, compound (H) can be selectively adsorbed to each region of the substrate surface depending on the material of each region. The contact angle of the substrate surface with water after exposure to the surface treatment agent can be, for example, 40° or more and 140° or less. There is no particular upper limit to the contact angle, but it is, for example, 140° or less, typically 130° or less.

[0051] In the surface treatment method according to the present embodiment, since the materials are different between two or more adjacent regions on the substrate surface, the exposure can selectively improve the hydrophobicity between the two or more adjacent regions, thereby making the water contact angles different from one another. The difference in water contact angle between the two or more adjacent regions is not particularly limited as long as it does not impair the effects of the present invention, and may be, for example, 10° or more. From the viewpoint of selectively improving hydrophobicity between the two or more adjacent regions, the difference in water contact angle is preferably 20° or more, more preferably 30° or more, and even more preferably 40° or more. The upper limit of the contact angle difference is not particularly limited as long as the effects of the present invention are not impaired, and is, for example, 80° or less or 70° or less, and typically 60° or less.

[0052] <Third aspect: method for selectively forming a film on a substrate> Next, a method for selectively forming a film on a substrate using the surface treatment method according to the second embodiment will be described. In this embodiment, a method for selectively forming a film on a substrate includes treating the surface of the substrate by the surface treatment method according to the second embodiment, and forming a film on the surface-treated surface of the substrate by atomic layer deposition (ALD), thereby selectively varying the amount of deposition of material for the film.

[0053] As a result of the surface treatment by the method according to the second aspect, the water contact angle (preferably the surface free energy) will be different between the two or more regions, and in this aspect, the deposition amount of the material forming the film can be selectively varied between the two or more regions on the substrate surface. Specifically, in a region where the contact angle of water between the two or more regions is larger than that between the other regions (preferably, the surface free energy is smaller), the film-forming material formed by the ALD method is less likely to be adsorbed (preferably chemically adsorbed) to the region on the substrate surface, resulting in a difference in the amount of film-forming material deposited between the two or more regions, and it is preferable that the amount of film-forming material deposited selectively differs between regions on the substrate. The chemical adsorption may be, for example, chemical adsorption with a hydroxyl group.

[0054] Among the two or more regions, the region that tends to have a larger water contact angle (preferably a smaller surface free energy) than the other region includes a region that contains at least one selected from the group consisting of W, Co, Al, Al2O3, Ni, Ru, Cu, TiN, and TaN. Among the two or more regions, the region that tends to have a smaller water contact angle (preferably, a higher surface free energy) than the other region includes a region that contains at least one selected from the group consisting of Si, Al2O3, SiN, Ox, TiN, TaN, Ge, and SiGe.

[0055] (Film formation by ALD method) Although there are no particular limitations on the film formation method using the ALD method, it is preferable that the method be a thin film formation method based on adsorption (preferably chemical adsorption) using at least two gas phase reactive substances (hereinafter simply referred to as "precursor gases"). Specifically, the method includes a method including the following steps (a) and (b), which are repeated at least once (one cycle) until a desired film thickness is obtained. (a) exposing a substrate that has been surface treated by the method according to the second aspect to a pulse of a first precursor gas; and (b) following step (a) above, exposing the substrate to a pulse of a second precursor gas.

[0056] After the above step (a) and before the above step (b), a plasma treatment step, a step of removing or evacuating (purging) the first precursor gas and its reactants using a carrier gas, a second precursor gas, etc., may or may not be included. After the above step (b), a plasma treatment step, a step of removing or purging the second precursor gas and its reactants with a carrier gas or the like, and the like may or may not be included. The carrier gas may be an inert gas such as nitrogen gas, argon gas, or helium gas.

[0057] Preferably, each pulse per cycle and each layer formed is self-limiting, and more preferably, each layer formed is a monolayer. The thickness of the monoatomic layer can be, for example, 5 nm or less, preferably 3 nm or less, more preferably 1 nm or less, and further preferably 0.5 nm or less.

[0058] Examples of the first precursor gas include organic metals, metal halides, and metal oxide halides, and specific examples thereof include tantalum pentaethoxide, tetrakis(dimethylamino)titanium, pentakis(dimethylamino)tantalum, tetrakis(dimethylamino)zirconium, tetrakis(dimethylamino)hafnium, tetrakis(dimethylamino)silane, copper hexafluoroacetylacetonate vinyltrimethylsilane, Zn(C2H5)2, Zn(CH3)2, TMA (trimethylaluminum), TaCl5, WF6, WOCl4, CuCl, ZrCl4, AlCl3, TiCl4, SiCl4, and HfCl4.

[0059] The second precursor gas may be a precursor gas capable of decomposing the first precursor or a precursor gas capable of removing a ligand of the first precursor, such as H2O, H2O2, O2O3, NH3, H2S, H2Se, PH3, AsH3, C2H4, or Si2H6.

[0060] The exposure temperature in step (a) is not particularly limited, and is, for example, 100°C or more and 800°C or less, preferably 150°C or more and 650°C or less, more preferably 180°C or more and 500°C or less, and even more preferably 200°C or more and 375°C or less.

[0061] The exposure temperature in step (b) is not particularly limited, but may be a temperature substantially equal to or higher than the exposure temperature in step (a). Films formed by the ALD method are not particularly limited, and examples thereof include films containing pure elements (e.g., Si, Cu, Ta, W), films containing oxides (e.g., SiO2, GeO2, HfO2, ZrO2, Ta2O5, TiO2, Al2O3, ZnO, SnO2, Sb2O5, B2O3, In2O3, WO3), films containing nitrides (e.g., Si3N4, TiN, AlN, BN, GaN, NbN), films containing carbides (e.g., SiC), films containing sulfides (e.g., CdS, ZnS, MnS, WS2, PbS), films containing selenides (e.g., CdSe, ZnSe), films containing phosphides (GaP, InP), films containing arsenides (e.g., GaAs, InAs), and mixtures thereof. EXAMPLES

[0062] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0063] <Synthesis Example 1: Synthesis of octadecanohydroxamic acid> Hydroxylamine hydrochloride (1.40g, 20.1mmol) and potassium carbonate (4.80g, 34.7mmol) were placed in a 500mL three-neck flask, and ethyl acetate (100.7g) and water (66.0g) were added under ice bath. After dissolution, a solution of stearoyl chloride (5.04g, 16.6mmol) in ethyl acetate (32.0g) was added using a dropping funnel and reacted at room temperature for 18 hours. The organic layer was removed, 1wt% HCl aqueous solution (108.1g) was added, and the mixture was stirred at room temperature for 25 minutes. This aqueous layer was extracted twice with ethyl acetate. The organic layers were combined and washed four times with 180g of water. The organic layers were dried using a rotary evaporator to obtain a crude product (4.48g). 2.48g of the crude product was added to 247.76g of methanol, dissolved under reflux, filtered, and the filtrate was allowed to cool at room temperature for 1 hour and filtered. The cake was recrystallized again from methanol to give white needle crystals of octadecanohydroxamic acid (0.98 g). The obtained compound was subjected to NMR measurement, and its structure was identified from the following results.

[0064] [ka]

[0065] 1 H-NMR(DMSO, 400MHz):δ(ppm)=0.85(t,CH3,3H),1.10-1.35(m,CH2,28H),1.45(t,CH2,2H),1.92,2.23(t,CH2,2H),8.65,8.97(s,NH,1H),9.72,10.35,(s,OH,1H)

[0066] <Preparation of surface treatment agent> The components shown in Table 1 were mixed to prepare the surface treatment agents of each example.

[0067] [Table 1]

[0068] Benzohydroxamic acid and octanohydroxamic acid were manufactured by Tokyo Chemical Industry Co., Ltd. The solvent used was propylene glycol monomethyl ether (PGME).

[0069] [Examples 1 to 3, Comparative Example 1] <Surface treatment> Using the surface treatment agents A to D prepared above, surface treatments were carried out on W substrates, Cu substrates, Co substrates, Al2O3 substrates, SiO2 substrates, TiN substrates and Ru substrates according to the following method. Specifically, each substrate was pretreated by immersing it in a 0.5% by mass aqueous HF solution at 25° C. for 1 minute. After the pretreatment, the substrate was washed with ion-exchanged distilled water for 1 minute. After washing with water, the substrate was dried with a nitrogen stream. After drying, each substrate was immersed in the surface treatment agent of each example at 60° C. for 60 minutes to perform surface treatment. The surface-treated substrate was washed with isopropanol for 1 minute, and then washed with ion-exchanged distilled water for 1 minute. The washed substrate was dried with a nitrogen stream to obtain a surface-treated substrate.

[0070] <Measurement of water contact angle> After the above surface treatment, the contact angle of water was measured for each substrate. The contact angle of water was measured using a Dropmaster 700 (manufactured by Kyowa Interface Science Co., Ltd.) by dropping a droplet of pure water (2.0 μL) onto the surface of the surface-treated substrate, and measuring the contact angle 2 seconds after the drop. The results are shown in Table 2 below.

[0071] [Table 2]

[0072] From the results shown in Table 2, it was confirmed that in Examples 1 to 3, in which surface treatment agents A to C were used, the contact angles of various substrates other than SiO2 were improved compared to Comparative Example 1, in which surface treatment agent D was used.

[0073] [Examples 4 to 9] <Heat treatment> Each of the substrates that had been surface-treated in the above <Surface Treatment> was subjected to a heat treatment in a nitrogen atmosphere under the heating conditions shown in Table 3.

[0074] <Measurement of water contact angle> After the heat treatment, the water contact angle of each substrate was measured. The contact angle of water was measured using a Dropmaster 700 (manufactured by Kyowa Interface Science Co., Ltd.) by dropping a droplet of pure water (2.0 μL) onto the surface of the surface-treated substrate, and measuring the contact angle 2 seconds after the drop. The results are shown in Table 3 below.

[0075] [Table 3]

[0076] From the results shown in Table 3, in Examples 4 and 5 in which surface treatment agent A was used, the contact angles on the Cu substrate, Co substrate, TiN substrate and Ru substrate decreased after heat treatment at 200°C for 20 minutes, confirming that the surface treatment agent can be detached from the substrate by high-temperature heat treatment. In Examples 6 to 7, in which surface treatment agent B was used, the contact angles on the Cu substrate, Co substrate, TiN substrate and Ru substrate decreased after heat treatment at 200°C for 20 minutes, confirming that the surface treatment agent can be desorbed from the substrate by high-temperature heat treatment. In Examples 8 to 9, in which surface treatment agent C was used, the contact angles on the W substrate, Cu substrate, Co substrate, TiN substrate and Ru substrate decreased after heat treatment at 200°C for 20 minutes, confirming that the surface treatment agent can be removed from the substrate by high-temperature heat treatment.

Claims

1. A substrate having a surface including two or more regions made of different materials; At least one region of the two or more regions is a second region including at least one selected from the group consisting of cobalt (Co), titanium nitride (TiN), and ruthenium (Ru); The first region adjacent to the second region is a region containing at least one selected from the group consisting of silicon, silicon nitride, silicon oxide film, germanium, and silicon germanium. A surface treatment agent used to treat the substrate, Contains a compound (H) represented by the following general formula (H-1): The content of the compound (H) in the surface treatment agent is 1 ppm to 20 mass % based on the total amount of the surface treatment agent. 【Chemistry 1】 [In the formula, R １ R is a linear or branched alkyl group having 1 to 30 carbon atoms which may have a substituent, a linear or branched fluorinated alkyl group having 1 to 30 carbon atoms which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a cycloalkyl group having 3 to 12 carbon atoms which may have a substituent. ２ represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms which may have a substituent, or a cycloalkyl group having 3 to 12 carbon atoms which may have a substituent.

2. A surface treatment method for a substrate having a surface including two or more regions made of different materials, comprising the steps of: At least one region of the two or more regions is a second region including at least one selected from the group consisting of cobalt (Co), titanium nitride (TiN), and ruthenium (Ru); The first region adjacent to the second region is a region containing at least one selected from the group consisting of SiN, Ox, TaN, Ge, and SiGe. Exposing the surface to the surface treatment of claim 1. Surface treatment method.

3. treating the surface of the substrate by the surface treatment method according to claim 2; forming a film on the surface of the surface-treated substrate by atomic layer deposition; The method for selectively depositing a film on a surface of a substrate, the method comprising selectively varying the amount of deposition of the material of the film on the surface of the substrate.

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