Surface treatment composition and wafer manufacturing method

Abstract

The surface treatment composition of the present invention is a surface treatment composition including a silylating agent and a solvent that is supplied as a vapor to the surface of a wafer having an uneven pattern on the surface to form a water-repellent protective film on the surface, wherein the silylating agent includes a trialkylsilylamine, the solvent includes at least one or more selected from the group consisting of glycol ether acetate and glycol acetate, and the total content of glycol ether acetate and glycol acetate is 50 mass% or more in the total of 100 mass% of solvent.

Description

[Technical Field]

[0001] The present invention relates to a surface treatment composition and a method for producing a wafer. [Background technology]

[0002] Semiconductor devices for networks and digital home appliances are required to achieve ever higher performance and functionality while reducing power consumption. This has led to the miniaturization of circuit patterns, which has led to the problem of pattern collapse. Cleaning processes are widely used in semiconductor device manufacturing to remove particles and metal impurities, and as a result, cleaning processes account for 30–40% of the entire semiconductor manufacturing process. As the aspect ratio of patterns increases with the miniaturization of semiconductor devices, pattern collapse occurs when the gas-liquid interface passes over the pattern after cleaning or rinsing. Preventing pattern collapse often requires changes to the pattern design and can lead to reduced production yields. Therefore, a method to prevent pattern collapse during the cleaning process is needed.

[0003] Forming a water-repellent protective film on the pattern surface is known to be an effective method for preventing pattern collapse. Since this water-repellent treatment must be performed without drying the pattern surface, a chemical liquid for forming a water-repellent protective film capable of making the pattern surface water-repellent is supplied to the pattern surface in a state where a cleaning liquid or the like is retained, and the water-repellent protective film is formed by replacing the cleaning liquid or the like with the chemical liquid.

[0004] Known examples of this type of technology include the technology described in Patent Document 1. Patent Document 1 describes a surface treatment composition containing a silylating agent, diethyl carbonate, and propylene carbonate as a solvent (see, for example, Example 5 of Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2019 / 193967 Summary of the Invention [Problem to be solved by the invention]

[0006] However, as a result of investigations by the present inventors, it has been found that the surface treatment composition described in Patent Document 1 has room for improvement in terms of surface modification ability and storage stability. [Means for solving the problem]

[0007] After further investigation, the present inventors found that the surface modification ability and storage stability of the surface treatment composition can be improved by using a trialkylsilylamine as the silylating agent and glycol ether acetate and / or glycol acetate as the solvent, and by setting the total content of these to a predetermined amount or more, and thus completed the present invention.

[0008] According to the present invention, A surface treatment composition comprising a silylating agent and a solvent, the surface treatment composition being supplied as a vapor to a surface of a wafer having a textured pattern on the surface, and being used to form a water-repellent protective film on the surface, the surface treatment composition comprising: the silylating agent comprises a trialkylsilylamine; the solvent contains at least one or more selected from the group consisting of glycol ether acetate and glycol acetate, the total content of the glycol ether acetate and the glycol acetate is 50% by mass or more in 100% by mass of the total amount of the solvent; A surface treatment composition is provided.

[0009] Further, according to the present invention, preparing a wafer having a relief pattern on its surface; supplying a cleaning liquid to the surface of the wafer to clean it; supplying vapor of a surface treatment composition to the surface holding the cleaning liquid, changing the state of the vapor to a liquid on the surface, and replacing the cleaning liquid with the liquid, thereby forming a water-repellent protective film on at least a portion of the surface, The surface treatment composition comprises: a silylating agent and a solvent, the silylating agent comprises a trialkylsilylamine; the solvent contains at least one or more selected from the group consisting of glycol ether acetate and glycol acetate, the total content of the glycol ether acetate and the glycol acetate is 50% by mass or more in 100% by mass of the total amount of the solvent; A method for manufacturing a wafer is provided. [Effects of the Invention]

[0010] According to the present invention, there are provided a surface treatment composition having excellent surface modification ability and storage stability, and a method for producing a wafer using the same. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic perspective view of a wafer having a fine uneven pattern on its surface; [Figure 2] FIG. 2 is a schematic cross-sectional view showing a part of the aa' cross section in FIG. [Figure 3] FIG. 2 is a schematic cross-sectional view showing a state in which vapor of a composition is supplied to a recess holding a liquid. [Figure 4] FIG. 2 is a schematic cross-sectional view of a wafer on which a water-repellent protective film is formed. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by similar reference numerals, and descriptions thereof will be omitted where appropriate. Furthermore, the drawings are schematic diagrams and do not correspond to actual dimensional proportions.

[0013] The surface treatment composition of this embodiment will be outlined below.

[0014] The surface treatment composition of this embodiment is supplied as a vapor to the surface of a wafer having a concave-convex pattern on its surface, and is used to form a water-repellent protective film on the surface. This surface treatment composition comprises a silylating agent and a solvent, the silylating agent comprising a trialkylsilylamine, the solvent comprising at least one or more selected from the group consisting of glycol ether acetate and glycol acetate, and is configured so that the total content of glycol ether acetate and glycol acetate is 50% by mass or more in 100% by mass of the total amount of the solvent.

[0015] By using the surface treatment composition of this embodiment and applying it to the production of a wafer having a concave-convex pattern on its surface, it is possible to prevent the concave-convex pattern from collapsing.

[0016] Here, the manufacturing of semiconductor wafers will be explained as an example. In the semiconductor wafer manufacturing process, a fine uneven pattern is formed on the surface of a substrate (wafer) through processes such as film deposition, lithography, and etching. Then, to clean the wafer surface, wet processes such as cleaning processes using water or organic solvents are carried out, and a drying process is also carried out to remove liquids such as cleaning fluids and rinse solutions that have adhered to the wafer during the wet processes. It is known that during such a drying process, deformation or collapse of the concave-convex pattern is likely to occur in wafers having fine concave-convex patterns. By forming a water-repellent protective film on the concave-convex pattern using vapor from the surface treatment composition and modifying the wafer surface to exhibit water repellency, it becomes possible to suppress deformation and collapse of the concave-convex pattern during the drying step, thereby realizing a wafer manufacturing method with excellent manufacturing stability.

[0017] According to the findings of the present inventors, it has been found that the surface modification ability and storage stability can be improved by using a trialkylsilylamine as a silylating agent in combination with glycol ether acetate and / or glycol acetate as a solvent, and by setting the total content of glycol ether acetate and the glycol acetate to 50 mass% or more relative to the total amount of solvent (100 mass%).

[0018] Although the detailed mechanism is unclear, it is thought that by using glycol ether acetate and / or glycol acetate, which are solvents that do not easily react with the silylating agent trialkylsilylamine, as the main component of the solvent, it is possible to suppress reactions in liquids and improve storage stability, and also to suppress reactions in gases (vapors), thereby preventing a decrease in surface modification ability. Furthermore, solvents with high boiling points (low volatility) preferentially aggregate on the wafer surface and are replaced by the cleaning liquid, which prevents the silylating agent from reacting with the cleaning liquid and being consumed, thereby preventing a decrease in surface modification ability.

[0019] The configuration of the surface treatment composition of this embodiment will be described in detail below.

[0020] (Silylating agent) The surface treatment composition contains one or more trialkylsilylamines as silylating agents.

[0021] Trialkylsilylamine is a silane compound having at least a structure in which three alkyl groups and one amino group are bonded to a silicon atom.

[0022] The alkyl group is a group selected from hydrocarbon groups having 1 to 10 carbon atoms and hydrocarbon groups having 1 to 10 carbon atoms in which some or all of the hydrogen atoms have been substituted with fluorine atoms.

[0023] Examples of amino groups include monovalent groups obtained by removing a hydrogen atom from a primary amine or a secondary amine. For example, -NH2, dialkylamino groups (-N(CH3)2, -N(C2H5)2, etc.), t-butylamino group, allylamino group, -NHSi(CH3)3, -NH-C(=O)-Si(CH3)3, -NHC(=O)CH3, -NHC(=O)CF3, -N(CH3)C(=O)CH3, -N(CH3)C(=O)CF3, -NHC(=O)-OSi(CH3)3, -NHC(=O)-NH-Si(CH3)3 (for example, N,N'-bis(trimethylsilyl)urea, etc.), and groups having a nitrogen-containing ring (wherein the nitrogen atom constituting the ring is bonded to the aforementioned Si atom), etc. may also be used. Examples of the nitrogen-containing ring include a piperidine ring, an imidazole ring (e.g., N-trimethylsilylimidazole, etc.), a triazole ring (e.g., N-trimethylsilyltriazole, etc.), a tetrazole ring, an oxazolidinone ring, a morpholine ring, and other nitrogen-containing heterocycles.

[0024] Specific examples of trialkylsilylamines include trimethylsilylamines such as trimethylsilyldimethylamine, trimethylsilyldiethylamine, N-(trimethylsilyl)-tertiarybutylamine, hexamethyldisilazane, trimethylsilylpiperidine, and N-(trimethylsilyl)-imidazole, as well as compounds in which the trimethylsilyl group of the above trimethylsilylamine is an ethyldimethylsilyl group, a propyldimethylsilyl group, a butyldimethylsilyl group, a hexyldimethylsilyl group, an octyldimethylsilyl group, and a decyldimethylsilyl group. These may be used alone or in combination of two or more. Among these, from the viewpoint of resistance to deactivation of the silylating agent upon vaporization (steam stability), trimethylsilyldimethylamine, trimethylsilyldiethylamine, N-(trimethylsilyl)-tertiarybutylamine, hexamethyldisilazane, and compounds in which the trimethylsilyl group of the trimethylsilylamine is an ethyldimethylsilyl group, a propyldimethylsilyl group, a butyldimethylsilyl group, a hexyldimethylsilyl group, an octyldimethylsilyl group, or a decyldimethylsilyl group are preferred. Furthermore, from the viewpoint of silylation reactivity, trimethylsilyldimethylamine, trimethylsilyldiethylamine, and N-(trimethylsilyl)-tertiarybutylamine are preferred.

[0025] The lower limit of the content of the silylating agent is, for example, 0.3 mass % or more, preferably 3 mass % or more, and more preferably 9 mass % or more, relative to 100 mass % of the surface treatment composition, which can improve the surface modification ability. On the other hand, the upper limit of the content of the silylating agent is, for example, 30% by mass or less, preferably 25% by mass or less, and more preferably 20% by mass or less, relative to 100% by mass of the surface treatment composition, thereby improving storage stability.

[0026] The lower limit of the trialkylsilylamine content is, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more, relative to 100% by mass of the silylating agent, which can improve the surface modification ability and storage stability. On the other hand, the upper limit of the content of trialkylsilylamine in 100% by mass of the silylating agent is not particularly limited, but may be 100% by mass or less, and when multiple silylating agents are used in combination, may be 98% by mass or less.

[0027] (solvent) The surface treatment composition contains one or more glycol ether acetates and / or glycol acetates as a solvent. When two or more glycol ether acetates and / or glycol acetates are contained, the content of the glycol ether acetates and / or glycol acetates in the solvent refers to the total amount of the glycol ether acetates and glycol acetates contained in the solvent.

[0028] Specific examples of glycol ether acetates and glycol acetates include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol diacetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol diacetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, triethylene glycol monobutyl ether acetate, triethylene glycol diacetate, tetraethylene glycol monomethyl ether acetate, tetraethylene glycol monoethyl ether acetate, tetraethylene glycol monobutyl ether acetate, tetraethylene glycol diacetate, propylene glycol Examples of the glycerin monomethyl ether acetate include propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, dipropylene glycol diacetate, tripropylene glycol monomethyl ether acetate, tripropylene glycol monoethyl ether acetate, tripropylene glycol monobutyl ether acetate, tripropylene glycol diacetate, tetrapropylene glycol monomethyl ether acetate, tetrapropylene glycol diacetate, butylene glycol monomethyl ether acetate, butylene glycol diacetate, glycerin triacetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, etc. These may be used alone or in combination of two or more. Among these, glycol ether acetate is preferred over glycol acetate because it has a lower boiling point and is therefore more likely to vaporize, and furthermore, from the viewpoint of storage stability, propylene glycol monomethyl ether acetate is more preferred.

[0029] The total content of at least one solvent selected from the group consisting of glycol ether acetate and glycol acetate is 50% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more, relative to 100% by mass of the total amount of solvents, thereby improving storage stability. On the other hand, the total content of solvents selected from glycol ether acetate and glycol acetate may be 100% by mass or less, and when multiple solvents are used in combination, it may be 98% by mass or less, based on 100% by mass of the total amount of solvents. Furthermore, substantially 100% by mass of the solvent may be at least one selected from the group consisting of glycol ether acetate and glycol acetate. "Substantially 100% by mass" means that no other solvents are intentionally mixed as the solvent.

[0030] The lower limit of the total content of glycol ether acetate and glycol acetate is, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more, based on 100% by mass of the surface treatment composition, thereby improving storage stability. On the other hand, the upper limit of the substantial total content of glycol ether acetate and glycol acetate is, for example, 99% by mass or less, preferably 97% by mass or less, more preferably 95% by mass or less, and even more preferably 92% by mass or less, based on 100% by mass of the surface treatment composition, which allows for a good balance between the surface modification ability and other properties.

[0031] (Surface treatment composition) In one example of this embodiment, the total content of trialkylsilylamine and at least one or more compounds selected from the group consisting of glycol ether acetate and glycol acetate is, for example, 60% by mass or more, preferably 80% by mass or more, and more preferably 95% by mass or more, relative to 100% by mass of the surface treatment composition, thereby improving the surface modification ability and storage stability. Another example of the surface treatment composition may consist of a silylating agent and at least one or more selected from the group consisting of glycol ether acetate and glycol acetate, and preferably, a trialkylsilylamine and at least one or more selected from the group consisting of glycol ether acetate and glycol acetate.

[0032] Furthermore, the surface treatment composition has a boiling point difference (boiling point of solvent - boiling point of silylating agent) between the boiling point of the solvent and the boiling point of the silylating agent at 1 atmosphere pressure of, for example, 20°C or higher, preferably 40°C or higher, and more preferably 55°C or higher. This allows the solvent with a higher boiling point to preferentially aggregate on the wafer surface and be replaced with the cleaning solution, thereby preventing the silylating agent from being deactivated by contact with the cleaning solution and preventing a decrease in surface modification ability. The boiling point difference is not particularly limited, as long as the solvent has a boiling point that does not thermally decompose the silylating agent during vaporization. The boiling point difference may be, for example, 200°C or lower, preferably 150°C or lower. The boiling point of a solvent or silylating agent containing multiple components is the boiling point of the component with the highest content (mass%) among the components contained in the solvent or silylating agent (however, if there are two or more components with the highest content, the boiling point of the component with the highest temperature is used).

[0033] The surface treatment composition preferably contains a small amount of water, and particularly preferably contains substantially no water.

[0034] The surface treatment composition of this embodiment may contain other components in addition to the above-mentioned components, provided that the purpose of the present invention is not impaired. Examples of such other components include silylating agents other than trialkylsilylamines, solvents other than glycol ether acetates and glycol acetates, surfactants, and antioxidants such as BHT (dibutylhydroxytoluene).

[0035] The surface treatment composition may be configured to contain no fluorine-based solvent or to contain a fluorine-based solvent in an amount of 2 mass% or less relative to 100 mass% of the surface treatment composition. By using a solvent that is substantially free of fluorine-based solvents, it is possible to improve the cohesion of the vapor of the surface treatment composition in the in-plane direction on the wafer surface. Examples of the fluorine-based solvent include hydrofluorocarbons, hydrofluoroethers, perfluorocarbons, and hydrochlorofluorocarbons.

[0036] The surface treatment composition may be configured so as to contain no acyclic carbonate ester or to contain the acyclic carbonate ester in an amount of 2 mass% or less relative to 100 mass% of the surface treatment composition. By using a solvent that is substantially free of acyclic carbonate ester, storage stability can be improved.

[0037] The surface treatment composition may be configured to contain no catalyst or to contain a catalyst in an amount of 2 mass % or less relative to 100 mass % of the surface treatment composition. The catalyst promotes the reaction between the wafer surface and the trialkylsilylamine. Examples of the catalyst include trimethylsilyl trifluoroacetate, trimethylsilyl trifluoromethanesulfonate, dimethylsilyl trifluoroacetate, dimethylsilyl trifluoromethanesulfonate, butyldimethylsilyl trifluoroacetate, butyldimethylsilyl trifluoromethanesulfonate, hexyldimethylsilyl trifluoroacetate, hexyldimethylsilyl trifluoromethanesulfonate, octyldimethylsilyl trifluoroacetate, octyldimethylsilyl trifluoromethanesulfonate, decyldimethylsilyl trifluoroacetate, decyldimethylsilyl trifluoromethanesulfonate, sulfonic acid, anhydrides of the sulfonic acid, salts of the sulfonic acid, sulfonic acid derivatives, sulfonic acid esters, sulfonimides, sulfonimide derivatives, sulfonmethides, sulfonmethide derivatives, acid imides, nitrogen-containing heterocyclic compounds, and silylated heterocyclic compounds. By preparing a surface treatment composition that is substantially free of a catalyst, storage stability can be improved.

[0038] The surface treatment composition of this embodiment can be obtained by mixing the above-mentioned components. The resulting mixture may be purified, if necessary, using an adsorbent, a filter, etc. Alternatively, each component may be purified in advance by distillation, and then purified using an adsorbent, a filter, etc.

[0039] The surface treatment composition is formulated so that the water contact angle of the silicon wafer surface after surface treatment, measured by the following procedure, is, for example, 70° or more, thereby achieving good surface modification ability. (procedure) A silicon wafer having a thermal oxide film layer on its surface is immersed in 1 mass % hydrofluoric acid at 25°C for 10 minutes, then in pure water at 25°C for 1 minute, and then in 2-propanol (iPA) at 25°C for 1 minute to be washed. The cleaned silicon wafer is placed horizontally with a puddle of iPA on it, and the vapor of the surface treatment composition is supplied to the silicon wafer. Subsequently, the vapor is changed into a liquid state on the surface of the silicon wafer, and the iPA held on the surface is replaced with the liquid. The silicon wafer is then immersed in iPA at 25° C. for 1 minute. Thereafter, air is blown onto the silicon wafer to remove the iPA from the surface. The water contact angle is measured on the silicon wafer surface obtained by the above steps using about 2 μl of pure water in accordance with JIS R 3257:1999 "Test method for wettability of substrate glass surface."

[0040] The surface treatment composition has a particle count of, for example, 1.0×10 per mL of the surface treatment composition, as measured using a light scattering liquid-borne particle detector. 4 1.0 × 10 or less, preferably 1.0 × 10 3 or less, more preferably 1.0 × 10 2This makes it possible to suppress the risk of contamination of the inside of the vapor treatment device, the vaporization chamber that vaporizes the surface treatment composition, other liquid delivery parts, etc., which may result in a decrease in device yield and reliability. On the other hand, the fewer the number of particles larger than 0.2 μm, the better, but as long as they are within the above content range, there may be one or more particles per mL of the composition. Particle measurements in the liquid phase of the surface treatment composition are performed using a commercially available measuring device that uses a laser as a light source for light scattering liquid particle measurement, and the particle size refers to the light scattering equivalent diameter based on PSL (polystyrene latex) standard particles. Particles include particles such as dust, dirt, organic solids, and inorganic solids that are contained as impurities in raw materials, and particles such as dust, dirt, organic solids, and inorganic solids that are introduced as contaminants during the preparation of a composition, and which ultimately exist as particles in the composition without dissolving.

[0041] The surface treatment composition is configured so that the total content of Na, Mg, Ca, Mn, Fe, Cu, Li, Al, Cr, Ni, Zn, and Ag in the surface treatment composition, as measured by inductively coupled plasma mass spectrometry, is, for example, 100 ppb by mass or less, preferably 10 ppb by mass or less, and more preferably 1 ppb by mass or less, thereby suppressing the risk of contamination inside the vapor treatment apparatus, which may result in reduced yield and reliability of devices. On the other hand, as long as the total content is within the above range, the content of each element may be 0.0001 ppb by mass or more relative to the total amount of the composition.

[0042] A method for producing a wafer using the surface treatment composition will be described below.

[0043] The method for manufacturing a wafer of this embodiment includes the steps of preparing a wafer having a concave-convex pattern on its surface, supplying a cleaning liquid to the surface of the wafer to clean it, and supplying vapor of the surface treatment composition to the surface holding the cleaning liquid, changing the state of the vapor to a liquid on the surface, replacing the cleaning liquid with the liquid, and forming a water-repellent protective film on at least a portion of the surface. In addition to the above steps, one or more of a pre-rinse (first rinse) step, a post-rinse (second rinse) step, a drying step, a step of removing the water-repellent protective film, and the like may be carried out. The surface treatment composition used in the method for producing a wafer of this embodiment may be the same as the surface treatment composition described above.

[0044] 1 to 4 show an example of a wafer manufacturing process using a surface treatment composition. Fig. 1 is a schematic perspective view of a wafer 1 whose surface has a fine uneven pattern 2. Fig. 2 is a schematic cross-sectional view of the wafer 1 showing a part of the a-a' cross section in Fig. 1. Fig. 3 is a diagram showing a step of supplying vapor 9 of a composition to a recess 4 holding a liquid 8. Fig. 4 is a diagram showing a step of cleaning, with liquid 10, the recess 4 on which a water-repellent protective film 11 has been formed by the composition.

[0045] First, a wafer 1 having a concave-convex pattern on its surface is prepared.

[0046] In the preparation step of the wafer 1, the following method may be used as an example of a method for forming the concave-convex pattern 2 on the wafer surface. First, a resist is applied to the wafer surface, and then the resist is exposed through a resist mask. Either the exposed or unexposed resist is removed to create a resist with the desired concave-convex pattern. Alternatively, a resist with a concave-convex pattern can be obtained by pressing a mold with a pattern onto the resist. Next, the wafer is etched. At this time, the substrate surface corresponding to the concave portions of the resist pattern is selectively etched. Finally, the resist is peeled off to obtain a wafer 1 with a concave-convex pattern 2 on its surface.

[0047] The wafer on which the concave-convex pattern 2 is formed and the material of the concave-convex pattern 2 are not particularly limited. The wafer 1 may be made of various materials such as a silicon wafer, a silicon carbide wafer, a wafer made of a plurality of components including silicon atoms, a sapphire wafer, or a wafer made of various compound semiconductors.

[0048] The material of the concave-convex pattern 2 may include one or more selected from the group consisting of Si, Ti, Ge, W, and Ru, as well as oxides, nitrides, nitrogen oxides, carbonitrides, and carbonoxides containing at least one of these. For example, the material of the concave-convex pattern 2 may include silicon-based materials such as silicon oxide, silicon nitride, polycrystalline silicon, single-crystalline silicon, and silicon germanium, metal-based materials such as titanium nitride, tungsten, ruthenium, tantalum nitride, and tin, combinations of these materials, and resist (photoresist) materials.

[0049] The concave-convex pattern 2 may be formed of a three-dimensional structure having, for example, one or more structures arranged along the vertical direction of the surface and / or one or more structures arranged along a horizontal direction perpendicular to the vertical direction. Examples of such three-dimensional structures may constitute at least a part of a logic device or memory device, such as a FinFET, a nanowire FET, a nanosheet FET, or other multi-gate FETs, a three-dimensional memory cell, etc.

[0050] FIG. 2 is a cross-sectional view showing an example of the concave-convex pattern 2. As shown in FIG. In this embodiment, the pattern dimension of the concave-convex pattern 2 can be defined as the dimension in at least one width direction in the in-plane direction of the surface and / or the dimension in at least one height direction perpendicular to the surface. In the cross-sectional structure (in the substrate thickness direction) of the concave-convex pattern 2, at least one of the pattern dimensions of its width and height, or in the three-dimensional structure (three-dimensional coordinates of X, Y, and Z) of the concave-convex pattern 2, at least one of the pattern dimensions of its width (length in the X-axis direction), height (length in the Y-axis direction), and depth (length in the Z-axis direction) may be, for example, 30 nm or less, 20 nm or less, or 10 nm or less. This may also be the spacing between patterns. The surface treatment composition of this embodiment can also be applied when using a wafer 1 having such a fine concave-convex pattern 2.

[0051] Such a surface treatment composition is suitable for use in surface treatment of a wafer 1 having a concave-convex pattern 2 with a pattern dimension of 30 nm or less, preferably 20 nm or less.

[0052] The aspect ratio of the protrusions 3 may be, for example, not less than 3, not less than 5, or not less than 10. Even in the concave-convex pattern 2 having protrusions 3 with a fragile structure, pattern collapse can be suppressed. On the other hand, the aspect ratio of the protrusions 3 is not particularly limited, but may be 100 or less. The aspect ratio of the protrusion 3 is expressed as the value obtained by dividing the height 6 of the protrusion by the width 7 of the protrusion.

[0053] The width 5 of the recess may be, for example, 70 nm or less, preferably 45 nm or less. The width 5 of the recess is indicated by the distance between adjacent protrusions 3 in the cross-sectional view of FIG.

[0054] Subsequently, the surface of the wafer 1 is cleaned with a cleaning liquid. In the cleaning step, the surface of the wafer 1 may be brought into contact with an aqueous cleaning solution, which is one of the cleaning liquids. Examples of aqueous cleaning solutions include water, alcohol, an ammonium hydroxide solution, a tetramethylammonium solution, a hydrofluoric acid solution, a hydrochloric acid solution, a hydrogen peroxide solution, a sulfuric acid solution, and an organic solvent, etc. These may be used alone or in combination of two or more.

[0055] The cleaning step may be carried out once or twice or more times before the surface treatment step or the first rinse step. Other steps may be included between multiple cleaning steps or between a cleaning step and a surface treatment step.

[0056] Subsequently, if necessary, the surface of the wafer 1 may be brought into contact with a first rinse solution (first rinse step).

[0057] The first rinse solution may be a cleaning solution different from the aqueous cleaning solution, such as water, an organic solvent, a mixture thereof, or a mixture of these with at least one of an acid, an alkali, a surfactant, and an oxidizing agent. Examples of organic solvents used in the first rinse solution include hydrocarbons, esters, ethers, ketones, halogen-containing solvents, sulfoxide-based solvents, alcohols, polyhydric alcohol derivatives, nitrogen-containing solvents, etc. Among these, it is preferable to use at least one organic solvent selected from alcohols having 3 or less carbon atoms, such as methanol, 1-propanol, and 2-propanol (isopropanol).

[0058] Alternatively, multiple types of first rinse solutions may be used. For example, rinsing may be performed in the following order: an acidic or alkaline aqueous solution, followed by an organic solvent. Alternatively, an additional aqueous cleaning solution may be added, followed by an acidic or alkaline aqueous solution, followed by the aqueous cleaning solution, followed by an organic solvent.

[0059] The first rinsing step may be performed once or twice or more times after the cleaning step or before the surface treatment step. Other steps may be included between multiple first rinsing steps or between the first rinsing step and the surface treatment step.

[0060] The cleaning liquid can be supplied by any known means, including, for example, a single wafer method, typified by a cleaning method using a spin cleaning device in which the wafer is held almost horizontally and rotated while the cleaning liquid is supplied near the center of rotation to clean the wafer one by one, and a batch method, in which a cleaning device is used to immerse multiple wafers in a cleaning tank and clean them. This allows the cleaning liquid to be held at least in the recesses 4 of the concave / convex pattern 2 of the wafer 1.

[0061] Next, with a cleaning liquid (liquid 8) held in at least the recesses 4 of the recessed / protruding pattern 2, vapor 9 of the surface treatment composition of this embodiment is supplied to the surface of the recessed / protruding pattern, causing the vapor 9 to change state to liquid 10 on the wafer surface, and replacing and holding the liquid 8 held in at least the recesses 4 with liquid 10, thereby forming a water-repellent protective film (protective film 11) on at least a portion of the wafer surface, for example, on the surface of the recesses 4.

[0062] When the vapor 9 of the surface treatment composition is supplied, the cleaning liquid (liquid 8) retained on the wafer surface may be the aqueous cleaning solution or the first rinse solution. From the viewpoint of manufacturing stability, the first rinse solution is preferred, and among these, 2-propanol (IPA) may be contained. That is, in one embodiment of the wafer manufacturing method, the vapor 9 of the surface treatment composition may be supplied while IPA is retained on the wafer surface.

[0063] The wafer manufacturing method may also include a step of preparing the surface treatment composition using raw materials having a total moisture content of, for example, 2000 mass ppm or less, preferably 500 mass ppm or less, more preferably 100 mass ppm or less, and even more preferably 50 mass ppm or less, relative to the total amount of the raw materials, thereby preventing a decrease in the surface modifying ability of the surface treatment composition.

[0064] Examples of a method for supplying the vapor 9 of the surface treatment composition include placing the wafer 1, which holds the liquid 8 at least in the recesses 4 of the concave-convex pattern 2, in a chamber, and separately evaporating the surface treatment composition to obtain a vapor, which is then supplied to the surface of the concave-convex pattern via a pipe or a nozzle. A carrier gas such as nitrogen gas or dry air may be used for supplying the vapor.

[0065] However, the method for vaporizing the surface treatment composition is not particularly limited to the above method. For example, a batch-type vaporization method may be used in which a predetermined amount of a liquid surface treatment composition is introduced into a vaporization chamber, and heated sufficiently to evaporate the entire amount of the surface treatment composition. After the entire amount has evaporated, the vapor 9 is sent to a pipe or nozzle to be supplied to the uneven pattern surface.

[0066] Another example is a continuous vaporization method in which droplets of the surface treatment composition are dropped onto a preheated small-scale vaporization section (for example, by providing a heating means in a part of a pipe), and the entire amount of the surface treatment composition is evaporated each time a drop is dropped, and the vapor 9 is sent to a pipe or a nozzle to be supplied to the uneven pattern surface.

[0067] The vaporization temperature is preferably controlled to a temperature at which there is no risk of thermal decomposition of the silylating agent, which is a protective film-forming component. A preferred condition for the vapor treatment is to introduce nitrogen gas, and after the composition of the mixed gas of the vapor and nitrogen gas obtained as described above becomes constant, supply the mixed gas to the uneven pattern surface. The ambient temperature around the substrate during processing, i.e., the temperature of the vapor, is preferably lower than the boiling point of the liquid 8 held in the recesses 4. If this condition is met, the liquid 8 held in the recesses can be prevented from volatilizing before being replaced with the surface treatment composition, which makes it easier to prevent the concave-convex pattern 2 from collapsing.

[0068] Fig. 3 is a schematic diagram showing a state in which steam 9 is supplied to a recess 4 holding a liquid 8. Fig. 4 is a schematic diagram showing a state in which a water-repellent protective film 11 has been formed on the recess 4 using a surface treatment composition. The wafer 1 in the schematic diagrams of Figs. 3 and 4 shows a part of the a-a' cross section of Fig. 1.

[0069] 3 and 4, the supplied vapor 9 changes state to liquid 10 in the recess 4, and the liquid 8 held in the recess 4 is replaced by the liquid 10, so that the liquid 10 is held in the recess 4. In order to promote or stabilize the above-mentioned state change, the temperature of the wafer 1 or the recess 4 may be adjusted by lowering it or keeping it constant.

[0070] On the wafer surface, the silylation agent in the liquid 10 reacts with the wafer surface, and the moieties having the water-repellent functional groups described above are fixed to the wafer surface, thereby forming a water-repellent protective film (protective film 11).

[0071] The protective film 11 does not necessarily have to be formed continuously or uniformly, but it is more preferable that it is formed continuously and uniformly, as this provides better water repellency.

[0072] By replacing the liquid 8 retained on the wafer surface, such as the first rinse solution or aqueous cleaning solution, with liquid 10 liquefied from vapor 9 of the surface treatment composition, it becomes possible to perform a surface modification treatment, i.e., to form a protective film 11, before the surface of the concave-convex pattern 2 on the surface of the wafer 1 becomes dry. This makes it possible to prevent the concave-convex pattern 2 from collapsing.

[0073] If necessary, the liquid 10 held on the wafer surface may be subjected to known means such as heating, decompression, or drying to promote the formation of the protective film 11 .

[0074] Subsequently, if necessary, the wafer surface on which the protective film 11 is formed may be brought into contact with a second rinse solution (second rinse step). As the second rinse solution, the same solutions as those exemplified as the first rinse solution can be used.

[0075] Alternatively, a plurality of types of second rinse solutions may be used. For example, rinsing can be performed by contacting the substrate with water and an organic solvent such as isopropanol in this order.

[0076] The second rinsing step may be performed once or twice or more times after the surface treatment step. Other steps may be included between multiple second rinsing steps or between the second rinsing step and the surface treatment step.

[0077] Subsequently, after the formation of the protective film 11, a drying step for drying the surface of the wafer 1 may be carried out as necessary. The drying step makes it possible to remove any liquid present on the surface of the wafer 1 . The liquid may include liquid 10, a second rinse solution, or a mixture thereof. As the drying means, for example, known means such as spin drying, IPA (2-propanol) vapor drying, Marangoni drying, heat drying, hot air drying, vacuum drying, and reduced pressure drying may be used.

[0078] The drying step may be performed once or twice or more times, for example, after the surface treatment step or after the second rinsing step. The drying step and the second rinsing step may be repeated alternately.

[0079] Subsequently, the protective film 11 on the surface of the wafer 1 may be removed (removal step). Removal methods include heating, UV irradiation, ozone exposure, plasma irradiation, and corona discharge. Treatment with a concentrated fluid such as a supercritical fluid (which may contain an acid, base, or oxidizing agent), or treatment using a gas-phase remover, may also be used. These methods may be used alone or in combination of two or more. These treatments may be performed under atmospheric pressure or reduced pressure.

[0080] In this manner, a wafer 1 (semiconductor substrate) is obtained using the surface treatment composition of this embodiment.

[0081] 3 is directed to a wafer pattern, but the present invention is not limited thereto. The substrate manufacturing method of this embodiment is directed to a resist pattern, and by using the surface treatment composition of the present invention in the cleaning and drying process, it is also possible to prevent the resist pattern from collapsing.

[0082] Although the manufacturing method has been described in which the supplying step is performed after the cleaning step, the present invention is not limited to this and the supplying step may be performed after various treatments performed on the concave-convex pattern 2. In addition to the above-described steps, the method for manufacturing a substrate may also include one or a combination of two or more known treatments. For example, a surface treatment such as a plasma treatment may be performed after the above-described removal step.

[0083] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. Below, examples of reference forms are added. 1. A surface treatment composition comprising a silylating agent and a solvent, which is supplied as a vapor to a surface of a wafer having a patterned surface, and is used to form a water-repellent protective film on the surface, the composition comprising: the silylating agent comprises a trialkylsilylamine; The solvent contains 50% by mass or more of glycol ether acetate relative to 100% by mass of the total amount of the solvent. Surface treatment composition. 2. The surface treatment composition according to 1., A surface treatment composition, wherein the content of the silylating agent is 0.3% by mass or more and 30% by mass or less, based on 100% by mass of the surface treatment composition. 3. The surface treatment composition according to 1. or 2., A surface treatment composition, wherein the content of the glycol ether acetate is 50% by mass or more relative to 100% by mass of the surface treatment composition. 4. The surface treatment composition according to any one of 1. to 3., The surface treatment composition, wherein the boiling point difference between the boiling point of the solvent and the boiling point of the silylating agent at 1 atmosphere (boiling point of the solvent - boiling point of the silylating agent) is 20°C or more. 5. The surface treatment composition according to any one of 1. to 4., The surface treatment composition, wherein the trialkylsilylamine comprises one or more selected from the group consisting of trimethylsilyldimethylamine, trimethylsilyldiethylamine, and N-(trimethylsilyl)-tertiarybutylamine. 6. The surface treatment composition according to any one of 1. to 5., A surface treatment composition, which has a water contact angle of 70° or more on a silicon wafer surface after surface treatment, as measured by the following procedure. (procedure) A silicon wafer having a thermal oxide film layer on its surface is immersed in a 1 mass % hydrofluoric acid aqueous solution at 25°C for 10 minutes, then in pure water at 25°C for 1 minute, and then in 2-propanol (iPA) at 25°C for 1 minute to be washed. The silicon wafer after cleaning is placed horizontally with a puddle of iPA on it, and the vapor of the surface treatment composition is supplied to the silicon wafer. Subsequently, the vapor is changed into a liquid state on the surface of the silicon wafer, and the iPA held on the surface is replaced with the liquid. Subsequently, the silicon wafer is immersed in iPA at 25° C. for 1 minute. Thereafter, air is blown onto the silicon wafer to remove the iPA from the surface. The water contact angle is measured on the silicon wafer surface obtained by the above steps using about 2 μl of pure water in accordance with JIS R 3257:1999 "Test method for wettability of substrate glass surface." 7. The surface treatment composition according to any one of 1. to 6., The surface treatment composition, wherein the solvent does not contain a fluorine-based solvent. 8. The surface treatment composition according to any one of 1. to 7., The surface treatment composition, wherein the solvent does not contain an acyclic carbonate ester. 9. The surface treatment composition according to any one of 1. to 8., A catalyst-free surface treatment composition. 10. The surface treatment composition according to any one of 1. to 9., The number of particles larger than 0.2 μm measured using a light scattering liquid particle detector is 1.0 × 10 per mL of the surface treatment composition. 4 The surface treatment composition has a particle size of 1000 or less. 11. The surface treatment composition according to any one of 1. to 10., A surface treatment composition, in which the total content of Na, Mg, Ca, Mn, Fe, Cu, Li, Al, Cr, Ni, Zn, and Ag in the surface treatment composition is 100 ppb by mass or less, as measured using inductively coupled plasma mass spectrometry. 12. Providing a wafer having a relief pattern on its surface; supplying a cleaning liquid to the surface of the wafer to clean it; supplying vapor of a surface treatment composition to the surface holding the cleaning liquid, changing the state of the vapor to a liquid on the surface, and replacing the cleaning liquid with the liquid, thereby forming a water-repellent protective film on at least a portion of the surface, the surface treatment composition comprises a silylating agent and a solvent; the silylating agent comprises a trialkylsilylamine; The solvent contains 50% by mass or more of glycol ether acetate relative to 100% by mass of the total amount of the solvent. Wafer manufacturing method. 13. A method for manufacturing a wafer according to 12., comprising: a method for manufacturing a wafer, the method comprising: supplying vapor of the surface treatment composition to the surface of the wafer while IPA is held on the surface of the wafer. 14. A method for manufacturing a wafer according to 12. or 13., A method for manufacturing a wafer, comprising: preparing the surface treatment composition using raw materials having a total moisture content of 2000 mass ppm or less based on the total amount of the raw materials. [Example]

[0084] EXAMPLES Hereinafter, examples will be given that more specifically disclose embodiments of the present invention, but the present invention is not limited to these examples.

[0085] [Example 1] (Preparation of Surface Treatment Composition) A surface treatment composition (hereinafter referred to as "composition") was obtained by mixing 5 g of trimethylsilyldimethylamine [(CH3)3Si-N(CH3)2] (hereinafter referred to as "TMSDMA") as a silylating agent and 95 g of propylene glycol monomethyl ether acetate (hereinafter referred to as "PGMEA") as a solvent. The compositions immediately after preparation were evaluated according to the procedures described in (A) and (B) below, and the results are shown in Table 1.

[0086] [Evaluation method] (A) Evaluation of storage stability of the composition After mixing the raw materials for the composition, the composition was left to stand at 45°C and then the appearance of the composition was visually observed. Those that showed no precipitation or precipitate of insoluble matter after one week were marked with a "◎", those that showed no precipitation or precipitate of insoluble matter after one day of standing but showed some precipitation or precipitate after one week were marked with a "○", and those that showed no precipitation or precipitate of insoluble matter after four hours of standing but showed some precipitation or precipitate after one day of standing were marked with a "△". Furthermore, those that showed precipitation or precipitate of insoluble matter within four hours of mixing the raw materials for the composition and standing at 45°C were marked with an "×".

[0087] The composition was analyzed by gas chromatography to check for changes in the concentration of the silylating agent during storage. The analysis was performed using a gas chromatography system (Shimadzu Corporation GC-2010Plus) equipped with a capillary column TC-1 (GL Sciences Inc.). Measurements were performed on samples immediately after preparation and on samples prepared and stored for 1 day at 45° C. For each composition, the reduction rate (%) of the silylating agent concentration was calculated from the ratio of the area % of the silylating agent in the chromatography chart of the control sample immediately after preparation to the area % of the silylating agent in the chromatography chart after storage, assuming the initial concentration in the control sample to be 100%.

[0088] (B) Evaluation of the surface modification ability of the composition (evaluation of the contact angle of the water-repellent protective film formed on the wafer surface) The technique of forming a wafer surface with a concave-convex pattern and replacing the cleaning liquid retained in at least the concave portions of the concave-convex pattern with another cleaning liquid has been variously studied in other literature, etc., and is already an established technique. In the present invention, the water repellency imparting effect when a wafer is surface-treated with vapor of a composition was evaluated.

[0089] However, in the case of a wafer having a concave-convex pattern on its surface, the contact angle of the protective film 11 (water-repellent protective film) itself formed on the concave-convex pattern surface cannot be accurately evaluated.

[0090] As specified in JIS R 3257:1999 "Test Method for Wettability of Substrate Glass Surfaces," the water droplet contact angle is evaluated by placing a few microliters of water on the surface of a sample (substrate) and measuring the angle between the water droplet and the substrate surface. However, in the case of wafers with patterns, the water droplet contact angle becomes very large. This is because the Wenzel effect and Cassie effect occur, and the contact angle is affected by the surface shape (roughness) of the substrate, increasing the apparent contact angle of the water droplet.

[0091] In this example, vapor of the composition was applied to a wafer having a smooth surface to form a protective film on the wafer surface, and the protective film was considered to be a protective film formed on the surface of a wafer having a concave-convex pattern formed on its surface, and evaluation was carried out according to the following procedure. Note that in this example, a silicon wafer with a thermal oxide film, which has an SiO layer on a smooth silicon wafer, was used as the wafer having a smooth surface.

[0092] (1) Silicon wafer cleaning A smooth silicon wafer with a thermal oxide film (a Si wafer having a 1 μm-thick thermal oxide film layer on its surface) was immersed in a 1% by mass aqueous solution of hydrofluoric acid at 25°C for 10 minutes, then in pure water at 25°C for 1 minute, and then in 2-propanol (hereinafter referred to as "iPA") at 25°C for 1 minute.

[0093] (2) Steam surface treatment on silicon wafer surface After the above cleaning, the silicon wafer was placed horizontally in a vapor treatment chamber with a puddle of iPA, and the solution-state composition prepared above was vaporized under the following vapor supply conditions, and the vapor was supplied to the vapor treatment chamber. The vapor supplied to the wafer surface at a temperature of 50° C. or less was then changed into a liquid state, and the iPA held on the wafer surface was replaced with the liquid.

[0094] Conditions for supplying the vapor of the above composition: 2 dm of nitrogen gas was supplied to a vaporization chamber heated to 145°C. 3 The solution composition prepared above was added dropwise at a rate of 0.01 g / sec while the solution was flowing at a flow rate of 1 / min. The entire amount added was vaporized. The vapor was immediately supplied to the vapor treatment chamber using a nitrogen gas flow. The treatment was carried out for 60 seconds.

[0095] (3) Silicon wafer cleaning Thereafter, the silicon wafer was removed from the vapor treatment chamber and immersed in iPA for 1 minute at 25° C. Finally, the silicon wafer was removed from the iPA and air was blown onto it to remove the iPA from the surface. In this way, a silicon wafer having a protective film formed on its surface was obtained.

[0096] (4) Water contact angle measurement of protective film Approximately 2 μl of pure water was placed on the wafer surface on which the protective film was formed, and the angle between the water droplet and the wafer surface (water contact angle) was measured using a contact angle meter (CA-X model, manufactured by Kyowa Interface Science Co., Ltd.) in accordance with JIS R 3257:1999 "Test method for wettability of substrate glass surfaces." Three samples of wafers on which the protective film was formed were prepared, and the water contact angle was measured for each sample. Table 1 shows the difference between the maximum and minimum water contact angles for the three samples as the variation in water contact angle. The water contact angle on the surface of the silicon wafer without a protective film formed on its surface, obtained by performing the treatments (1) and (3) without performing the above (2), was less than 10°.

[0097] [Table 1]

[0098] [Example 2] A composition was prepared in the same manner as in Example 1, except that 7 g of TMSDMA as a silylating agent and 93 g of PGMEA as a solvent were mixed to obtain a composition, and various evaluations were carried out. The results are shown in Table 1.

[0099] [Example 3] A composition was prepared in the same manner as in Example 1, except that 9 g of TMSDMA as a silylating agent and 91 g of PGMEA as a solvent were mixed to obtain a composition, and various evaluations were carried out. The results are shown in Table 1.

[0100] [Example 4] A composition was prepared in the same manner as in Example 1, except that 11 g of TMSDMA as a silylating agent and 89 g of PGMEA as a solvent were mixed to obtain a composition, and various evaluations were carried out. The results are shown in Table 1.

[0101] [Example 5] A composition was prepared in the same manner as in Example 1, except that 13 g of TMSDMA as a silylating agent and 87 g of PGMEA as a solvent were mixed to obtain a composition, and various evaluations were carried out. The results are shown in Table 1.

[0102] [Example 6] A composition was prepared in the same manner as in Example 1, except that 3 g of TMSDMA was used as a silylating agent and 97 g of PGMEA was used as a solvent, and various evaluations were carried out. The results are shown in Table 1. [Example 7] A composition was prepared in the same manner as in Example 1, except that 11 g of propyldimethylsilyldimethylamine [(CH3CH2CH2)(CH3)2Si-N(CH3)2] (hereinafter abbreviated as "PDMSDMA") was mixed as a silylating agent and 89 g of PGMEA as a solvent to obtain a composition, and various evaluations were carried out. The results are shown in Table 1. [Example 8] A composition was prepared in the same manner as in Example 1, except that 11 g of butyldimethylsilyldimethylamine [(CH3CH2CH2CH2)(CH3)2Si-N(CH3)2] (hereinafter abbreviated as "BDMSDMA") was mixed as a silylating agent and 89 g of PGMEA as a solvent to obtain a composition, and various evaluations were carried out. The results are shown in Table 1.

[0103] [Comparative Example 1] A composition was prepared in the same manner as in Example 1, except that 5 g of TMSDMA was used as a silylating agent, and 45 g of propylene carbonate and 50 g of diethyl carbonate were mixed together as solvents to obtain a composition. Various evaluations were carried out, and the results are shown in Table 1.

[0104] The surface treatment compositions of Examples 1 to 8 had a water contact angle of 70° or more and had good water repellency. Furthermore, the water contact angle measurement (4) above was repeatedly performed using the compositions immediately after preparation, and the results showed that the variation in the measured values ​​was suppressed. The surface treatment compositions of Examples 1 to 8 could be used practically without any problems in the wafer manufacturing process. On the other hand, Comparative Example 1 had a water contact angle of 70° or more, but tended to have a larger variation than Examples 1 to 8. In other words, Examples 1 to 8 exhibited better surface modification ability than Comparative Example 1 in that they achieved both good water repellency and suppressed variation in the water contact angle. Furthermore, the surface treatment compositions of Examples 1 to 8 were subjected to a storage stability evaluation of the above (A) composition, and the results showed that the occurrence of precipitation in the composition was suppressed and the fluctuation in the concentration of the silylating agent in the composition was small compared to Comparative Example 1. The surface treatment compositions of Examples 1 to 8 showed results in which the silylating agent concentration hardly fluctuated from immediately after preparation until one month later, while the surface treatment composition of Comparative Example 1 showed results in which the silylating agent concentration decreased over time when measured 6 hours and 4 days after preparation. From the above, the surface treatment compositions of Examples 1 to 8 showed results in which the storage stability was superior to that of Comparative Example 1.

[0105] This application claims priority based on Japanese Patent Application No. 2021-029887, filed on February 26, 2021, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0106] 1 wafer 2. Concave and convex patterns 3 Convex part 4 recess 5 Recess width 6 Height of the convex part 7. Width of the convex part 8 liquid 9. Steam 10 liquid 11 Protective film

Claims

1. A surface treatment composition comprising a silylating agent and a solvent, the surface treatment composition being supplied as a vapor to a surface of a wafer having a textured pattern on the surface, and being used to form a water-repellent protective film on the surface, the surface treatment composition comprising: the silylating agent comprises a trialkylsilylamine; the solvent contains at least one or more selected from the group consisting of glycol ether acetate and glycol acetate, the total content of the glycol ether acetate and the glycol acetate is 50% by mass or more in 100% by mass of the total amount of the solvent; the boiling point difference between the boiling point of the solvent and the boiling point of the silylating agent at 1 atmosphere (boiling point of the solvent - boiling point of the silylating agent) is 20°C or more; Surface treatment composition.

2. The surface treatment composition according to claim 1, A surface treatment composition, wherein the content of the silylating agent is 0.3 mass % or more and 30 mass % or less, based on 100 mass % of the surface treatment composition.

3. The surface treatment composition according to claim 1 or 2, A surface treatment composition, wherein the total content of the glycol ether acetate and the glycol acetate is 50% by mass or more relative to 100% by mass of the surface treatment composition.

4. The surface treatment composition according to any one of claims 1 to 3, The surface treatment composition, wherein the trialkylsilylamine comprises one or more selected from the group consisting of trimethylsilyldimethylamine, trimethylsilyldiethylamine, and N-(trimethylsilyl)-tertiarybutylamine.

5. The surface treatment composition according to any one of claims 1 to 4, A surface treatment composition, which has a water contact angle of 70° or more on a silicon wafer surface after the surface treatment, as measured by the following procedure. (procedure) A silicon wafer having a thermal oxide film layer on its surface is immersed in a 1 mass % aqueous solution of hydrofluoric acid at 25°C for 10 minutes, then in pure water at 25°C for 1 minute, and then in 2-propanol (iPA) at 25°C for 1 minute, for cleaning. The silicon wafer after cleaning is placed horizontally with a puddle of iPA on it, and the vapor of the surface treatment composition is supplied to the silicon wafer. Subsequently, the vapor is changed into a liquid state on the surface of the silicon wafer, and the iPA held on the surface is replaced with the liquid. Subsequently, the silicon wafer is immersed in iPA at 25° C. for 1 minute. Thereafter, air is blown onto the silicon wafer to remove the iPA from the surface. The water contact angle is measured on the silicon wafer surface obtained by the above steps using about 2 μl of pure water in accordance with JIS R 3257:1999 "Test method for wettability of substrate glass surface."

6. The surface treatment composition according to any one of claims 1 to 5, A surface treatment composition that does not contain a fluorine-based solvent.

7. The surface treatment composition according to any one of claims 1 to 6, A surface treatment composition that does not contain an acyclic carbonate ester.

8. The surface treatment composition according to any one of claims 1 to 7, A catalyst-free surface treatment composition.

9. The surface treatment composition according to any one of claims 1 to 8, The number of particles larger than 0.2 μm measured using a light scattering liquid-borne particle detector is 1.0 × 10 per mL of the surface treatment composition. ４ The surface treatment composition has a particle size of 1000 or less.

10. The surface treatment composition according to any one of claims 1 to 9, A surface treatment composition, in which the total content of Na, Mg, Ca, Mn, Fe, Cu, Li, Al, Cr, Ni, Zn, and Ag in the surface treatment composition is 100 ppb by mass or less, as measured by inductively coupled plasma mass spectrometry.

11. preparing a wafer having a relief pattern on its surface; supplying a cleaning liquid to the surface of the wafer to clean it; supplying vapor of a surface treatment composition to the surface holding the cleaning liquid, changing the state of the vapor to a liquid on the surface, and replacing the cleaning liquid with the liquid, thereby forming a water-repellent protective film on at least a portion of the surface, The surface treatment composition comprises: a silylating agent and a solvent, the silylating agent comprises a trialkylsilylamine; the solvent contains at least one or more selected from the group consisting of glycol ether acetate and glycol acetate, the total content of the glycol ether acetate and the glycol acetate is 50% by mass or more in 100% by mass of the total amount of the solvent; In the surface treatment composition, the boiling point difference between the boiling point of the solvent and the boiling point of the silylating agent at 1 atmosphere (boiling point of the solvent - boiling point of the silylating agent) is 20°C or more. Wafer manufacturing method.

12. 12. The method for manufacturing a wafer according to claim 11, The method for producing a wafer, wherein the content of the silylating agent in the surface treatment composition is 0.3 mass % or more and 30 mass % or less, based on 100 mass % of the surface treatment composition.

13. 13. The method for manufacturing a wafer according to claim 11 or 12, A method for producing a wafer, wherein the total content of the glycol ether acetate and the glycol acetate in the surface treatment composition is 50 mass % or more relative to 100 mass % of the surface treatment composition.

14. A method for manufacturing a wafer according to any one of claims 11 to 13, comprising: The method for producing a wafer, wherein in the surface treatment composition, the trialkylsilylamine comprises one or more selected from the group consisting of trimethylsilyldimethylamine, trimethylsilyldiethylamine, and N-(trimethylsilyl)-tertiarybutylamine.

15. A method for manufacturing a wafer according to any one of claims 11 to 14, comprising: The method for producing a wafer, wherein the surface treatment composition does not contain a fluorine-based solvent.

16. A method for manufacturing a wafer according to any one of claims 11 to 15, The method for producing a wafer, wherein the surface treatment composition does not contain an acyclic carbonate ester.

17. A method for manufacturing a wafer according to any one of claims 11 to 16, comprising: The method for producing a wafer, wherein the surface treatment composition does not contain a catalyst.

18. A method for manufacturing a wafer according to any one of claims 11 to 17, comprising: In the surface treatment composition, the number of particles larger than 0.2 μm as measured using a light scattering liquid-borne particle detector is 1.0 × 10 per mL of the surface treatment composition. ４ A method for manufacturing a wafer,

19. A method for manufacturing a wafer according to any one of claims 11 to 18, comprising: a total content of Na, Mg, Ca, Mn, Fe, Cu, Li, Al, Cr, Ni, Zn, and Ag in the surface treatment composition, as measured by inductively coupled plasma mass spectrometry, of 100 ppb by mass or less.

20. A method for manufacturing a wafer according to any one of claims 11 to 19, comprising: a wafer manufacturing method including supplying vapor of the surface treatment composition to the wafer while IPA is held on the surface of the wafer;

21. A method for manufacturing a wafer according to any one of claims 11 to 20, comprising: A method for manufacturing a wafer, comprising: preparing the surface treatment composition using raw materials having a total moisture content of 2000 mass ppm or less with respect to the total amount of the raw materials.

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