Surface treatment agent, surface treatment method, method for producing electronic device, and electronic device

Abstract

Disclosed is a surface treatment agent for treating the surface of a substrate, the surface treatment agent containing polyhedral oligomeric silsesquioxane particles (A) and an organic solvent (B).

Description

Surface treatment agent, surface treatment method, method for manufacturing electronic device, and electronic device

[0001] The present disclosure relates to a surface treatment agent, a surface treatment method, a method for manufacturing an electronic device, and an electronic device.

[0002] Some semiconductor device manufacturing methods include a step of processing the surface of a substrate (e.g., a wafer, etc.) Patent Document 1 discloses, for example, a technique for processing the surface of such a substrate.

[0003] Patent Document 1 describes a method for making a substrate water-repellent, which includes exposing the surface of the substrate to a surface treatment agent, the surface treatment agent containing a water-repellent agent (A) and a nitrogen-containing heterocyclic compound (B), and the water-repellent agent (A) containing an alkoxymonosilane compound having a hydrophobic group bonded to a silicon atom. It is also described that the method for making a substrate water-repellent described in Patent Document 1 can provide a substrate with excellent water-repellent properties.

[0004] Japanese Patent Application Laid-Open No. 2019-119791

[0005] In some cases, the contact angle of the substrate surface with water decreases, and therefore, there is a demand for improving the contact angle of such substrates with water.

[0006] The present disclosure has been made in consideration of the above circumstances, and provides a surface treatment agent that can improve the contact angle of a substrate.

[0007] According to the present disclosure, there are provided the following surface treatment agent, surface treatment method, method for manufacturing an electronic device, and electronic device.

[0008] [1] A surface treatment agent for treating a surface of a substrate, comprising: cage-type silsesquioxane particles (A) and an organic solvent (B). [2] The cage-type silsesquioxane constituting the cage-type silsesquioxane particles (A) is T ８ [3] The surface treatment agent according to [1], which contains a cage-type silsesquioxane having a structure of T ８ The surface treatment agent according to [2] above, wherein the cage silsesquioxane structure is represented by the following general formula (1): (Note that in general formula (1), R １ ~R ８may be the same or different and are any one selected from the group consisting of a hydrocarbon group having 1 to 20 carbon atoms and a silyl ether group. [4] The surface treatment agent according to any one of [1] to [3] above, wherein the cage-type silsesquioxane particles (A) have an average particle size of 0.3 nm to 5.0 nm, as obtained by the following method. [Method] A chloroform solution of the cage-type silsesquioxane particles (A) is subjected to particle size measurement by dynamic light scattering, and the average particle size of the peak observed in the particle size range of 0.3 nm to 10.0 nm is obtained. [5] The surface treatment agent according to any one of [1] to [4] above, wherein the content of the cage-type silsesquioxane particles (A) in the surface treatment agent is 0.001 mass% to 1.00 mass%, when the content of all components in the surface treatment agent is taken as 100 mass%. [6] The surface treatment agent according to any one of [1] to [5], wherein the organic solvent (B) comprises at least one selected from the group consisting of halogen-containing solvents, ketone-based solvents, alcohol-based solvents, ether-based solvents, sulfoxide-based solvents, carbonate-based solvents, nitrogen-containing solvents, and ester-based solvents. [7] The surface treatment agent according to [6], wherein the organic solvent (B) comprises at least one selected from the group consisting of chloroform, acetone, cyclohexanone, isopropyl alcohol, methyl isobutyl carbinol, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate. [8] The surface treatment agent according to any one of [1] to [7], wherein the total content of the cage silsesquioxane particles (A) and the organic solvent (B) in the surface treatment agent is 70% by mass or more and 100% by mass or less, when the total content of all components in the surface treatment agent is 100% by mass. [9] The surface treatment agent according to any one of [1] to [8], wherein the content of the resin component in the surface treatment agent is less than 5% by mass, where the content of all components in the surface treatment agent is 100% by mass.

[10] The surface treatment agent according to any one of [1] to [9], wherein the substrate is a silicon substrate or a silicon oxide film substrate.

[11] A surface treatment method, comprising: a step (a) of treating a surface of a substrate with the surface treatment agent according to any one of [1] to

[10] .

[12] The surface treatment method according to

[11] above, further comprising a pre-cleaning step (b) of cleaning the substrate before the step (a).

[13] The surface treatment method according to

[11] or

[12] above, further comprising a post-cleaning step (c) of cleaning the substrate after the step (a).

[14] A method for manufacturing an electronic device, comprising a step of treating the surface of a substrate by the surface treatment method according to any one of

[11] to

[13] above.

[15] An electronic device comprising a substrate surface-treated with the surface treatment agent according to any one of [1] to

[10] above.

[0009] According to the present disclosure, it is possible to provide a surface treatment agent that can improve the contact angle of a substrate.

[0010] Hereinafter, embodiments of the present disclosure will be described. Note that "to" between numbers in the text indicates "above" or "below" unless otherwise specified. Also, unless otherwise specified, "contact angle" refers to the contact angle of the substrate with water.

[0011] [Surface Treatment Agent] The surface treatment agent of this embodiment is a surface treatment agent for treating the surface of a substrate, and contains cage silsesquioxane particles (A) and an organic solvent (B).

[0012] Hereinafter, each component constituting the surface treatment agent of this embodiment will be described.

[0013] <Cage-Type Silsesquioxane Particles (A)> The surface treatment agent of the present embodiment contains the cage-type silsesquioxane particles (A).

[0014] The cage silsesquioxane constituting the cage silsesquioxane particles (A) is not particularly limited, and examples thereof include, for example, T ８ Cage-type silsesquioxane with the structure T ６ Cage-type silsesquioxane with the structure T １０ Cage-type silsesquioxanes and T １２ The compound preferably contains at least one selected from the group consisting of cage-type silsesquioxanes having the structure T ８ It includes cage-type silsesquioxanes having the following structure.

[0015] Here, T ｎThe cage silsesquioxane structure is represented by the general formula (RSiO １．５ ) ｎ In the general formula, R represents any organic group, and may be the same or different.

[0016] T ８ The cage silsesquioxane structure is preferably represented by the following general formula (1):

[0017]

[0018] In general formula (1), R １ ~R ８ may be the same or different and are any one selected from the group consisting of hydrocarbon groups having 1 to 20 carbon atoms and silyl ether groups.

[0019] In general formula (1), R １ ~R ８ In the formula (I), the hydrocarbon group having 1 to 20 carbon atoms is not particularly limited, but examples thereof include at least one selected from the group consisting of a methyl group, an ethyl group, an isobutyl group, an octyl group, an octadecyl group, a cyclopentyl group, a cyclohexyl group, a vinyl group, and a phenyl group, and preferably at least one selected from the group consisting of a methyl group, a vinyl group, a cyclohexyl group, an isobutyl group, and a phenyl group.

[0020] In general formula (1), R １ ~R ８ In the formula, the silyl ether group is not particularly limited, but examples thereof include the silyl ether group represented by the general formula "-OSiR ９ ３ ", a group represented by the general formula "-OSiR １０ ２ H" and a group represented by the general formula "-OSiR １１ ２ -CH=CH ２ ". ９ ~R １１may be the same or different and are hydrocarbon groups having 1 to 20 carbon atoms. The hydrocarbon group having 1 to 20 carbon atoms is not particularly limited, but examples thereof include at least one selected from the group consisting of a methyl group, an ethyl group, an isobutyl group, an octyl group, an octadecyl group, a cyclopentyl group, a cyclohexyl group, a vinyl group, and a phenyl group, and is preferably at least one selected from the group consisting of a methyl group, a vinyl group, a cyclohexyl group, an isobutyl group, and a phenyl group. ９ ３ " specifically includes groups represented by -OSi(Me) ３ , —OSi(Et) ３ , -OSi(Ph) ３ , —OSi(Me) ２ (tBu), -OSi(tBu) ３ and —OSi(Ph) ２ (tBu), etc. １０ ２ Specific examples of the group represented by "H" include -OSi(Me) ２ H, -OSi(Et) ２ H, -OSi(tBu) ２ H, -OSi(Ph) ２ H, and —OSi(Me)(tBu)H, etc. １１ ２ -CH=CH ２ " specifically includes groups represented by -OSi(Me) ２ -CH=CH ２ , —OSi(Et) ２ -CH=CH ２ , -OSi(tBu) ２ -CH=CH ２ , -OSi(Ph) ２ -CH=CH ２ , and —OSi(Me)(tBu)—CH═CH ２ At least one selected from the group consisting of:

[0021] In general formula (1), R １ ~R８ Preferably, the surface treatment agent does not contain at least one selected from the group consisting of an alkoxy group, a silanol group, and an epoxy group. Specific examples of the alkoxy group include at least one selected from the group consisting of a methoxy group and an ethoxy group. When the substrate is a silicon substrate or a silicon oxide film substrate, the absence of the above-mentioned substituents inhibits bonding of the cage silsesquioxane particles (A) to the substrate surface, making it easier to adjust the contact angle to the desired range when the post-cleaning step (c) is performed after the surface treatment step (a). Furthermore, the absence of the above-mentioned substituents is preferable because it improves the stability of the surface treatment agent and extends its lifespan.

[0022] T ８ The cage silsesquioxane structure preferably includes at least one selected from the group consisting of octamethyloctasilsesquioxane, octavinyloctasilsesquioxane, octacyclohexyloctasilsesquioxane, octaisobutylsilsesquioxane, and octaphenylsilsesquioxane.

[0023] The cage-shaped silsesquioxane particles (A) obtained by the following method preferably have an average particle diameter of 5.0 nm or less, more preferably 4.0 nm or less, even more preferably 3.0 nm or less, even more preferably 2.5 nm or less, and even more preferably 2.0 nm or less, and the lower limit is not particularly limited, but is, for example, 0.3 nm or more. In particular, in the field of electronic device manufacturing, it is preferable that the average particle diameter of the cage-shaped silsesquioxane particles (A) be the above-mentioned upper limit or less, because this can prevent the surface of the substrate from becoming rough due to surface treatment.

[0024] [Method] A chloroform solution of the cage-shaped silsesquioxane particles (A) is subjected to particle size measurement by dynamic light scattering, and the average particle size of the peak observed in the particle size range of 0.3 nm to 10.0 nm is obtained.

[0025] More specifically, the autocorrelation function obtained in particle size measurement is analyzed by cumulant analysis to obtain the cumulant diameter of the peak observed in the particle size range of 0.3 nm to 10.0 nm. The obtained cumulant diameter is taken as the average particle size. Note that, if two or more peaks are observed in the particle size range of 0.3 nm to 10.0 nm, the average particle size of the peak with the smallest particle size can be used to measure the average particle size of the primary particles, i.e., the monomolecular size of the cage silsesquioxane particles themselves. In this specification, the average particle size of the cage silsesquioxane particles (A) refers to the average particle size of the aforementioned primary particles.

[0026] In the measurement sample for particle size measurement, i.e., the chloroform solution of the cage silsesquioxane particles (A), the concentration of the cage silsesquioxane particles (A) can be appropriately adjusted according to the dispersion state of the cage silsesquioxane particles (A) in the chloroform solution. More specifically, the concentration of the cage silsesquioxane particles (A) can be adjusted so that a peak is observed in the particle size range of 0.3 nm to 10.0 nm in the particle size distribution obtained by analyzing the autocorrelation function obtained in particle size measurement by dynamic light scattering measurement using the NNLS method (non-negative least squares method). In the chloroform solution of the cage silsesquioxane particles (A), the concentration of the cage silsesquioxane particles (A) may be 0.01% by mass or 0.1% by mass.

[0027] Cage-shaped silsesquioxane particles (A) is preferably a monomer.In other words, the oligomer of the cage-shaped silsesquioxane monomer in the cage-shaped silsesquioxane particles (A) polymerized with each other, the polymer of the cage-shaped silsesquioxane monomer polymerized with each other, and the total content of the copolymer of the cage-shaped silsesquioxane monomer and other monomer components, when the whole of the cage-shaped silsesquioxane particles (A) is taken as 100 mass%, preferably less than 20 mass%, more preferably less than 10 mass%, even more preferably less than 5 mass%, even more preferably less than 3 mass%, even more preferably less than 1 mass%, and cage-shaped silsesquioxane particles (A) more preferably do not contain at least one selected from the group consisting of the oligomer of the cage-shaped silsesquioxane monomer polymerized with each other, the polymer of the cage-shaped silsesquioxane monomer polymerized with each other, and the copolymer of the cage-shaped silsesquioxane monomer and other monomer components.

[0028] The content of the cage silsesquioxane particles (A) in the surface treatment agent is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, even more preferably 0.008% by mass or more, and is preferably 1.00% by mass or less, more preferably 0.50% by mass or less, even more preferably 0.30% by mass or less, even more preferably 0.20% by mass or less, when the content of all components in the surface treatment agent is taken as 100% by mass.

[0029] The cage-type silsesquioxane particles (A) may be a single type of cage-type silsesquioxane particle, or two or more types of cage-type silsesquioxane particles may be used in combination.

[0030] <Organic Solvent (B)> The surface treatment agent of the present embodiment contains an organic solvent (B).

[0031] The organic solvent (B) is not particularly limited, but preferably contains at least one solvent selected from the group consisting of halogen-containing solvents, ketone-based solvents, alcohol-based solvents, ether-based solvents, sulfoxide-based solvents, carbonate-based solvents, nitrogen-containing solvents, and ester-based solvents.

[0032] Examples of halogen-containing solvents include perfluorocarbons such as perfluorooctane, perfluorononane, perfluorocyclopentane, perfluorocyclohexane, and hexafluorobenzene; hydrofluorocarbons such as 1,1,1,3,3-pentafluorobutane, octafluorocyclopentane, 2,3-dihydrodecafluoropentane, and Zeorora H (manufactured by Zeon Corporation); methyl perfluoropropyl ether, methyl perfluoroisobutyl ether, methyl perfluorobutyl ether, ethyl perfluorobutyl ether, ethyl perfluoroisobutyl ether, methyl perfluorohexyl ether, ethyl perfluorohexyl ether, Asahiklin AE-3000 (manufactured by AGC Corporation), Novec HFE-7100, and Novec Examples include hydrofluoroethers such as HFE-7200, Novec7300, and Novec7600 (all manufactured by 3M); chlorocarbons such as tetrachloromethane; hydrochlorocarbons such as chloroform; chlorofluorocarbons such as dichlorodifluoromethane; hydrochlorofluorocarbons such as 1,1-dichloro-2,2,3,3,3-pentafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane, 1-chloro-3,3,3-trifluoropropene, and 1,2-dichloro-3,3,3-trifluoropropene; perfluoroethers; and perfluoropolyethers.

[0033] Examples of ketone solvents include acetone, acetylacetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, cyclohexanone, and isophorone.

[0034] Examples of alcohol-based solvents include methanol, ethanol, 1-propanol, 2-propanol (isopropyl alcohol), 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 1-hexanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 4-methyl-1-pentanol, 5-methyl-1-pentanol, 6-methyl-1-pentanol, 7-methyl-1-pentanol, 8-methyl-1-pentanol, 9-methyl-1-pentanol, 10-methyl-1-pentanol, 11-methyl-1-pentanol, 12-methyl-1-pentanol, 13-methyl-1-pentanol, 14-methyl-1-pentanol, 15-methyl-1-pentanol, 16-methyl-1-pentanol, 17-methyl-1-pentanol, 18-methyl-1-pentanol, 19-methyl-1-pentanol, 20-methyl-1-pentanol, 21-methyl-1-pentanol, 22-methyl-1-pentanol, 23-methyl-1-pentanol, 24-methyl-1-pentanol, 25-methyl-1-pentanol, 26-methyl-1-pentanol, 27-methyl-1-pentanol, 28-methyl-1-pentanol, 29-methyl-1-pentanol, 21-methyl-1-pentanol, 22-methyl-1-pentanol, 23-methyl-1-pentanol, 2 ethanol, 2-methyl-2-pentanol, 3-methyl-2-pentanol, 4-methyl-2-pentanol (methyl isobutylcarbinol), 2-methyl-3-pentanol, 3-methyl-3-pentanol, 2,2-dimethyl-1-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 4-heptanol, benzyl alcohol, 1-octanol, isooctanol, 2-ethyl-1-hexanol, and the like.

[0035] Examples of ether solvents include di-n-propyl ether, ethyl-n-butyl ether, di-n-butyl ether, ethyl-n-amyl ether, di-n-amyl ether, ethyl-n-hexyl ether, di-n-hexyl ether, di-n-octyl ether, as well as ethers having a branched hydrocarbon group such as diisopropyl ether and diisoamyl ether which correspond to the carbon numbers of these ether solvents, dimethyl ether, diethyl ether, methyl ethyl ether, methylcyclopentyl ether, diphenyl ether, tetrahydrofuran, dioxane, and propylene glycol monomethyl ether.

[0036] An example of a sulfoxide solvent is dimethyl sulfoxide.

[0037] Examples of carbonate solvents include dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and propylene carbonate.

[0038] Examples of nitrogen-containing solvents include formamide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-diisopropyl-2-imidazolidinone, diethylamine, triethylamine, and pyridine.

[0039] Examples of ester solvents include ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-pentyl acetate, i-pentyl acetate, n-hexyl acetate, n-heptyl acetate, n-octyl acetate, n-pentyl formate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, methyl n-octanoate, methyl decanoate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl 2-oxobutanoate, dimethyl adipate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, and propylene glycol monomethyl ether acetate.

[0040] Furthermore, as the ester-based solvent, a cyclic ester-based solvent such as a lactone compound may be used. Examples of the lactone compound include β-propiolactone, γ-butyrolactone, γ-valerolactone, γ-hexanolactone, γ-heptanolactone, γ-octanolactone, γ-nonanolactone, γ-decanolactone, γ-undecanolactone, γ-dodecanolactone, δ-valerolactone, δ-hexanolactone, δ-octanolactone, δ-nonanolactone, δ-decanolactone, δ-undecanolactone, δ-dodecanolactone, and ε-hexanolactone.

[0041] Among the above, the organic solvent (B) preferably includes at least one selected from the group consisting of chloroform, acetone, cyclohexanone, isopropyl alcohol, methyl isobutyl carbinol, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate, and from the viewpoint of further improving the dispersibility of the cage silsesquioxane particles (A) in the surface treatment agent, more preferably includes at least one selected from the group consisting of chloroform and cyclohexanone.

[0042] The organic solvent (B) is preferably a high-purity organic solvent in which metal impurities, particles, etc. are suppressed, and more preferably an organic solvent of electronics industry grade.

[0043] As the organic solvent (B), one organic solvent may be used alone, or two or more organic solvents may be used in combination.

[0044] <Other Components> The surface treatment agent of the present embodiment may contain other components in addition to the cage silsesquioxane particles (A) and the organic solvent (B). Examples of other components include a dispersant. The content of the other components is an appropriate amount.

[0045] When the content of all components in the surface treatment agent is taken as 100% by mass, from the viewpoint of further improving the contact angle of the substrate, the content of the resin component in the surface treatment agent of this embodiment is preferably less than 5% by mass, more preferably less than 3% by mass, even more preferably less than 1% by mass, even more preferably less than 0.5% by mass, even more preferably less than 0.1% by mass, even more preferably less than 0.05% by mass, and even more preferably less than 0.01% by mass, and it is even more preferable that the surface treatment agent of this embodiment does not contain a resin component.

[0046] When the content of all components in the surface treatment agent is taken as 100 mass%, the total content of the cage silsesquioxane particles (A) and the organic solvent (B) in the surface treatment agent of this embodiment is, from the viewpoint of further improving the contact angle of the substrate, preferably 70 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, even more preferably 95 mass% or more, even more preferably 97 mass% or more, and even more preferably 99 mass% or more; and the upper limit is not particularly limited, but is, for example, 100 mass% or less.

[0047] The surface treatment agent of the present embodiment is preferably non-aqueous, and even if moisture is inevitably mixed in, the content of water in the surface treatment agent is preferably less than 1% by mass or less than 0.1% by mass, where the content of all components in the surface treatment agent is taken as 100% by mass.

[0048] [Method for Producing Surface Treatment Agent] The surface treatment agent of this embodiment can be obtained, for example, by mixing the respective components.

[0049] [Use of Surface Treatment Agent] The surface treatment agent of this embodiment is a surface treatment agent for treating the surface of a substrate, and is preferably a surface treatment agent that can be used in the surface treatment method described below.

[0050] The substrate of this embodiment can be, for example, a semiconductor wafer or a semiconductor substrate. The material of the substrate of this embodiment is not particularly limited, and can be, for example, a silicon substrate, a silicon oxide film substrate, a silicon carbide substrate, a germanium substrate, a sapphire substrate, a gallium phosphide substrate, a gallium arsenide substrate, an indium phosphide substrate, a gallium nitride substrate, etc., among which, a silicon substrate or a silicon oxide film substrate is preferred. The inventors believe that when the substrate of this embodiment is a silicon substrate or a silicon oxide film substrate, these substrates have an atomic composition similar to that of the cage silsesquioxane particles (A), and therefore, it is possible to improve the contact angle of the substrate without significantly affecting various physical properties such as heat resistance and chemical resistance.

[0051] [Surface Treatment Method] The surface treatment method of this embodiment is a surface treatment method including a step (a) of treating the surface of a substrate with the surface treatment agent of this embodiment.

[0052] Each step of the surface treatment method of this embodiment will be described below.

[0053] <Step (a)> The surface treatment method of this embodiment includes step (a) of treating the surface of a substrate with the surface treatment agent of this embodiment.

[0054] In the step (a), the method for treating the surface of the substrate is not particularly limited, and examples thereof include a method for treating the surface of the substrate by immersing the substrate in the surface treatment agent of the present embodiment; a method for treating the surface of the substrate by applying the surface treatment agent of the present embodiment to the substrate; and the like.

[0055] When the surface of a substrate is treated by immersing the substrate in the surface treatment agent of this embodiment, the immersion conditions are not particularly limited, and may be, for example, a temperature condition of 20° C. or higher and 30° C. or lower, and an immersion time of 10 seconds or higher and 5 minutes or lower.

[0056] When treating the surface of a substrate by applying the surface treatment agent of this embodiment to the substrate, the specific application method and conditions are not particularly limited, but for example, a method of application using a spin coater may be used.

[0057] In step (a), the substrate may be dried after the above-mentioned immersion, coating, etc. The method for drying the substrate is not particularly limited, and the substrate may be dried, for example, by a nitrogen gas flow.

[0058] <Step (b)> The surface treatment method of this embodiment preferably further includes a pre-cleaning step (b) of cleaning the substrate before step (a). Step (b) is a step performed before step (a), and any step may be included between step (b) and step (a).

[0059] In the step (b), the method for washing the substrate is not particularly limited, but for example, a method of immersing the substrate in a solvent and then drying the substrate can be mentioned.

[0060] The solvent for cleaning the substrate may be, for example, isopropanol. The time for which the substrate is immersed is not particularly limited, but may be, for example, 10 seconds to 5 minutes.

[0061] The method for drying the substrate is not particularly limited, but for example, the substrate may be dried using a nitrogen gas flow.

[0062] <Step (c)> The surface treatment method of the present embodiment preferably further includes a post-cleaning step (c) of cleaning the substrate after step (a). Step (c) is a step performed after step (a), and any step may be included between step (a) and step (c).

[0063] In the surface treatment method of this embodiment, by performing step (a) on a substrate whose contact angle has decreased, the contact angle can be improved. On the other hand, performing step (a) may cause the contact angle of the substrate to become larger than the desired range. In such a case, by performing step (c) after step (a), it is possible to adjust the contact angle to within the desired range.

[0064] In the step (c), the method for washing the substrate is not particularly limited, but for example, a method of immersing the substrate in a solvent and then drying the substrate can be mentioned.

[0065] As the solvent for cleaning the substrate, the solvents described above as examples of the organic solvent (B) can be used, such as isopropanol, chloroform, cyclohexanone, etc. The time for immersing the substrate is not particularly limited, but may be, for example, 10 seconds to 5 minutes.

[0066] The method for drying the substrate is not particularly limited, but for example, the substrate may be dried using a nitrogen gas flow.

[0067] [Method for Manufacturing an Electronic Device] The method for manufacturing an electronic device of this embodiment includes a step of treating the surface of a substrate by the surface treatment method of this embodiment.

[0068] The electronic device in this embodiment includes elements, devices, final products, etc. that apply electronic engineering technology, such as semiconductor devices, semiconductor chips, and semiconductor elements.

[0069] The method for manufacturing an electronic device according to this embodiment may include other steps in addition to the step of treating the surface of the substrate by the surface treatment method according to this embodiment. Examples of other steps include general steps in the manufacture of semiconductor devices, such as a film formation step, a pattern transfer step, an etching step, a dicing step, and a sealing step.

[0070] [Electronic Device] The electronic device of this embodiment is an electronic device including a substrate that has been surface-treated with the surface treatment agent of this embodiment.

[0071] The preferred range of the contact angle of the surface-treated substrate of this embodiment is as follows. When the substrate is a silicon substrate, the contact angle of the surface-treated substrate is preferably 29° or more, more preferably 31° or more, and even more preferably 33° or more, and may be, for example, 120° or less or 110° or less. When the substrate is a silicon oxide film substrate, the contact angle of the surface-treated substrate is preferably 45° or more, more preferably 48° or more, and even more preferably 50° or more, and may be, for example, 90° or less or 80° or less. The contact angle of the surface-treated substrate of this embodiment means the value of the contact angle of water measured by the method described in the examples. When the surface-treated substrate of this embodiment has a contact angle within the above range, it is preferable because it makes it less likely that dirt attached together with the cleaning solvent will remain on the substrate in the drying step after cleaning as a subsequent step.

[0072] Although the embodiments of the present disclosure have been described above, these are merely examples of the present disclosure, and various configurations other than those described above may be adopted. Furthermore, the present disclosure is not limited to the above-described embodiments, and modifications, improvements, etc. within the scope of achieving the object of the present disclosure are included in the present disclosure.

[0073] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples.

[0074] [Raw Materials] First, the raw materials used in the Examples and Comparative Examples will be described. The cage silsesquioxane particles (A), organic solvents (B), and substrates shown in Table 1 are as follows.

[0075] Cage-shaped silsesquioxane particles (A) T8-Me: octamethyloctasilsesquioxane (manufactured by Sigma-Aldrich Co.) T8-Vi: octavinyloctasilsesquioxane (manufactured by Tokyo Chemical Industry Co., Ltd.) T8-Cy: octacyclohexyloctasilsesquioxane (manufactured by Sigma-Aldrich Co.)

[0076] Organic solvent (B) S1: Chloroform (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) S2: Cyclohexanone (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.)

[0077] Substrate Si: Silicon substrate SiOx: Silicon oxide film substrate

[0078] [Preparation of Surface Treatment Agent] Example 1 Octamethyloctasilsesquioxane was dissolved in chloroform so that the content of octamethyloctasilsesquioxane in the surface treatment agent was 0.1 mass%, and the solution was filtered through a 0.2 μm filter to prepare the surface treatment agent of Example 1. Examples 2 to 14 Surface treatment agents of Examples 2 to 14 were each prepared in the same manner as Example 1, except that the cage silsesquioxane particles (A), organic solvent (B), and the content of the cage silsesquioxane particles (A) in the surface treatment agent were set as shown in Table 1.

[0079] [Surface Treatment of Substrate] Example 1 A silicon substrate (Si) was immersed in isopropanol for 1 minute, and then dried in a nitrogen stream to clean the substrate (pre-cleaning step (b)). Next, the silicon substrate (Si) was immersed in the surface treatment agent of Example 1 for 30 seconds at room temperature (25°C), and then the substrate was removed and dried in a nitrogen stream (substrate surface treatment step (a)). In this way, the surface-treated substrate of Example 1 was obtained.

[0080] <Examples 3, 4, 6, 8, 9, and 11 to 14> Substrates were surface-treated in the same manner as in Example 1 to obtain the surface-treated substrates of Examples 3, 4, 6, 8, 9, and 11 to 14. The surface treatment agents and substrates used were those listed in Table 1.

[0081] <Examples 2, 5, 7, and 10> Substrates were each subjected to surface treatment in the same manner as in Example 1. That is, step (b) and step (a) were each performed. Next, the substrates obtained after step (a) were each washed by immersing them in isopropanol for 1 minute (IPA washing), and then dried in a nitrogen gas stream (post-washing step (c)). In this manner, the surface-treated substrates of Examples 2, 5, 7, and 10 were each obtained. The surface treatment agents and substrates used were those listed in Table 1.

[0082] <Comparative Examples 1 and 2> No surface treatment was performed on the substrates listed in Table 1. That is, the substrate of Comparative Example 1 was a raw silicon substrate (Si), and the substrate of Comparative Example 2 was a raw silicon oxide film substrate (SiOx).

[0083] [Measurement and Evaluation] <Particle Size Measurement> (Measurement Example 1) Octamethyloctasilsesquioxane (T8-Me) was diluted with chloroform to prepare a 0.01% by mass chloroform solution. This was used as a measurement sample, and particle size measurement was performed using a Zetasizer Nano ZS (manufactured by Malvern Instruments) by dynamic light scattering. The measurement conditions were as follows: Temperature of measurement sample: 25°C Viscosity of measurement sample: 0.63 cP Refractive index of measurement sample: 1.44 The particle size distribution was obtained by analyzing the autocorrelation function obtained in the particle size measurement using the NNLS method (non-negative least squares method). Furthermore, the autocorrelation function obtained in the particle size measurement was analyzed using cumulant analysis to obtain a cumulant diameter in the particle size range of 0.3 nm to 10.0 nm. The obtained cumulant diameter was taken as the average particle size. A peak was confirmed in the particle size distribution in the particle size range of 0.3 nm to 10.0 nm. The average particle size at the peak of this particle size range was 0.7 nm.

[0084] (Measurement Example 2) Particle size measurement by dynamic light scattering was carried out in the same manner as in Measurement Example 1, except that the measurement sample was prepared by diluting octavinyloctasilsesquioxane (T8-Vi) with chloroform to prepare a 0.1 mass% chloroform solution. In the particle size distribution, a peak was observed in the particle size range of 0.3 nm or more and 10.0 nm or less. The average particle size of the peak in that particle size range was 1.7 nm.

[0085] <Measurement of Contact Angle of Substrate> The contact angle of water was measured for the surface-treated substrates of Examples 1 to 14 and the substrates of Comparative Examples 1 and 2. The contact angle of water was measured using a DMs-601 (manufactured by Kyowa Interface Science Co., Ltd.) when a droplet (2.0 μL) of pure water was dropped onto the surface of a horizontally placed substrate. The temperature during measurement was room temperature (25° C.). The results are shown in Table 1.

[0086]

[0087] In the item "Step (c)" in Table 1, "Y" means an example in which the post-cleaning step (c) was performed, and "N" means an example in which the post-cleaning step (c) was not performed.

[0088] As shown in Table 1, the substrates of Examples 1 to 11 had improved contact angles compared to the substrate of Comparative Example 1. Furthermore, the substrates of Examples 12 to 14 had improved contact angles compared to the substrate of Comparative Example 2. That is, it can be seen that the surface treatment agent of the present embodiment can improve the contact angle of the substrate.

[0089] Furthermore, it can be seen from Table 1 that the surface treatment method of this embodiment, which includes the post-cleaning step (c), can adjust the contact angle of the substrate to a desired value.

[0090] This application claims priority based on Japanese Patent Application No. 2023-129878, filed August 9, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A surface treatment agent for treating a surface of a substrate, comprising: a cage-type silsesquioxane particle (A); and an organic solvent (B).

2. The cage-type silsesquioxane constituting the cage-type silsesquioxane particles (A) is T ８ The surface treatment agent according to claim 1 , comprising a cage-type silsesquioxane having the structure:

3. Said T ８ 3. The surface treatment agent according to claim 2, wherein the cage-type silsesquioxane structure is represented by the following general formula (1): (In the general formula (1), R １ ~R ８ may be the same or different and are any one selected from the group consisting of a hydrocarbon group having 1 to 20 carbon atoms and a silyl ether group.

4. The surface treatment agent according to any one of claims 1 to 3, wherein the cage-type silsesquioxane particles (A) have an average particle size of 0.3 nm or more and 5.0 nm or less, as obtained by the following method: [Method] A chloroform solution of the cage-type silsesquioxane particles (A) is subjected to particle size measurement by dynamic light scattering measurement, and the average particle size of the peak observed in the particle size range of 0.3 nm or more and 10.0 nm or less is obtained.

5. A surface treatment agent according to any one of claims 1 to 3, wherein the content of the cage-type silsesquioxane particles (A) in the surface treatment agent is 0.001 mass% or more and 1.00 mass% or less, when the content of all components in the surface treatment agent is 100 mass%.

6. The surface treatment agent according to any one of claims 1 to 3, wherein the organic solvent (B) comprises at least one selected from the group consisting of halogen-containing solvents, ketone-based solvents, alcohol-based solvents, ether-based solvents, sulfoxide-based solvents, carbonate-based solvents, nitrogen-containing solvents, and ester-based solvents.

7. The surface treatment agent according to claim 6, wherein the organic solvent (B) includes at least one selected from the group consisting of chloroform, acetone, cyclohexanone, isopropyl alcohol, methyl isobutyl carbinol, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate.

8. A surface treatment agent according to any one of claims 1 to 3, wherein the total content of the cage-type silsesquioxane particles (A) and the organic solvent (B) in the surface treatment agent is 70 mass% or more and 100 mass% or less, when the content of all components in the surface treatment agent is 100 mass%.

9. A surface treatment agent according to any one of claims 1 to 3, wherein the content of the resin component in the surface treatment agent is less than 5% by mass when the content of all components in the surface treatment agent is 100% by mass.

10. The surface treatment agent according to any one of claims 1 to 3, wherein the substrate is a silicon substrate or a silicon oxide substrate.

11. A surface treatment method comprising the step (a) of treating a surface of a substrate with the surface treatment agent according to any one of claims 1 to 3.

12. The surface treatment method according to claim 11, further comprising a pre-cleaning step (b) of cleaning the substrate prior to the step (a).

13. The surface treatment method according to claim 11, further comprising a post-cleaning step (c) of cleaning the substrate after the step (a).

14. A method for manufacturing an electronic device, comprising the step of treating the surface of a substrate by the surface treatment method according to claim 11.

15. An electronic device comprising a substrate whose surface has been treated with the surface treatment agent according to any one of claims 1 to 3.

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