Semiconductor device manufacturing method, substrate, and silylated composition

Abstract

This semiconductor device manufacturing method includes: a preparation step for preparing a substrate provided with a structure that includes a first surface for which the silicon single crystal orientation is (100), a second surface having a (110) orientation, and a film containing silicon oxide formed atop the second surface; a silylation step for selectively forming a water-repellent film on the film containing silicon oxide atop the second surface by supplying a silylating agent onto at least the second surface; and an etching step for selectively etching the first surface with respect to the second surface by supplying an etching solution onto at least the first surface.

Description

Method for manufacturing semiconductor device, substrate, and silylation composition

[0001] The present invention relates to a method for manufacturing a semiconductor device, a substrate, and a silylation composition.

[0002] Various anisotropic etching techniques for silicon have been developed to date. One such technique is described in Patent Document 1. Patent Document 1 describes that when an etching solution containing hydrogen fluoride and ozone water is used in a surface roughening treatment step, the etching rate ratio depending on the crystal plane orientation is Si(100):Si(110)=1:0.6.

[0003] Japanese Patent Application Laid-Open No. 2006-134993

[0004] However, as a result of investigations by the present inventors, it was found that there is room for improvement in the etching selectivity of the Si(100) surface relative to the Si(110) surface in the etching method described in Patent Document 1.

[0005] After further investigation, the inventors discovered that the etching selectivity of the Si(100) surface relative to the Si(110) surface can be improved by forming a water-repellent film selectively on the Si(110) surface and then etching the Si(100) surface and the Si(110) surface, and thus completed the present invention.

[0006] According to one aspect of the present invention, there are provided the following method for manufacturing a semiconductor device, a substrate, and a silylation composition.

[0007] Examples of reference embodiments are given below. 1. A method for manufacturing a semiconductor device, comprising: a preparation step of preparing a substrate having a structure including a first surface of a silicon single crystal with a (100) plane orientation, a second surface with a (110) plane orientation, and a film containing silicon oxide formed on the second surface; a silylation step of supplying a silylating agent onto at least the second surface to form a water-repellent film selectively with respect to the film containing silicon oxide on the second surface; and an etching step of supplying an etching solution onto at least the first surface to selectively etch the first surface with respect to the second surface. 2. The method for manufacturing a semiconductor device according to 1., wherein the preparation step of preparing the substrate includes an oxidation treatment of forming the film containing silicon oxide on at least the exposed second surface. 3. 1. or 2. 4. The method for manufacturing a semiconductor device according to 2. or 3., wherein the preparation step of preparing the base material includes: an oxidation treatment for forming a first film containing silicon oxide and a second film containing silicon oxide on the exposed first surface and the exposed second surface, respectively; and a selective removal treatment for removing the first film containing silicon oxide on the first surface and leaving the second film containing silicon oxide on the second surface. 4. The method for manufacturing a semiconductor device according to 2. or 3., wherein the oxidation treatment includes a treatment for contacting a gaseous oxidizing agent or a treatment for contacting a liquid oxidizing agent. 5. The method for manufacturing a semiconductor device according to 3., wherein the selective removal treatment uses a solution containing hydrogen fluoride. 6. The method for manufacturing a semiconductor device according to 5., wherein the concentration of hydrogen fluoride in the solution containing hydrogen fluoride is 0.01 mass % or more and 10 mass % or less. 7. 5. or 6. 8. The method for manufacturing a semiconductor device according to any one of 1. to 7., wherein the solution containing hydrogen fluoride contains one or more selected from the group consisting of hydrofluoric acid, buffered hydrofluoric acid, hexafluorosilicic acid, and ammonium hexafluorosilicate. 8. The method for manufacturing a semiconductor device according to any one of 1. to 7., wherein the etching solution contains a quaternary ammonium hydroxide.9. The method for manufacturing a semiconductor device according to any one of 1. to 8., wherein the silylation step includes supplying the silylating agent or supplying a silylation composition containing the silylating agent and a catalytic compound. 10. The method for manufacturing a semiconductor device according to any one of 1. to 9., wherein the structure of the substrate has a plate-like structure. 11. The method for manufacturing a semiconductor device according to any one of 1. to 10., wherein CA is used to measure the water contact angle on the first surface immediately after the step of preparing the substrate. １Ｘ , the water contact angle on the second surface is CA ２Ｘ , the water contact angle on the first surface immediately after the silylation step is CA １Ｙ , the water contact angle on the second surface is CA ２Ｙ When this is done, |CA １Ｙ -CA １Ｘ |<|CA ２Ｙ -CA ２Ｘ 12. A method for manufacturing a semiconductor device according to 11., which satisfies |CA １Ｙ -CA １Ｘ | is 29° or less and |CA ２Ｙ -CA ２Ｘ | is 30° or more. 13. The method for manufacturing a semiconductor device according to any one of 1. to 12., wherein in the etching step, an etching selectivity of the first surface to the second surface is 2 or more. 14. A substrate having a structure including: a first surface of silicon single crystal having a (100) plane orientation; a second surface of silicon single crystal having a (110) plane orientation; a film containing silicon oxide formed on the second surface; and a water-repellent film formed on the film containing silicon oxide on the second surface. 15. A silylation composition used for forming a water-repellent film on a film containing silicon oxide formed on a second surface of silicon single crystal having a (110) plane orientation, the silylation composition comprising a silylation agent.

[0008] According to the present invention, there are provided a method for manufacturing a semiconductor device, a substrate, and a silylation composition that are excellent in selectivity for anisotropic etching in the Si-plane orientation.

[0009] FIG. 1 is a process cross-sectional view schematically showing an example of a preparatory step in a method for manufacturing a substrate. FIG. 2 is a process cross-sectional view schematically showing an example of a preparatory step in a method for manufacturing a substrate. FIG. 3 is a process cross-sectional view schematically showing an example of a silylation step in a method for manufacturing a substrate. FIG. 4 is a process cross-sectional view schematically showing an example of a silylation step in a method for manufacturing a substrate. FIG. 5 is a process cross-sectional view schematically showing an example of an etching step in a method for manufacturing a substrate.

[0010] 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.

[0011] An outline of the method for manufacturing the semiconductor device of this embodiment will be described.

[0012] The method for manufacturing a semiconductor device according to the present embodiment includes the steps of: preparing a substrate having a structure including a first surface of a silicon single crystal with a (100) plane orientation, a second surface with a (110) plane orientation, and a film containing silicon oxide formed on the second surface; a silylation step of supplying a silylation agent onto at least the second surface to selectively form a water-repellent film on the film containing silicon oxide on the second surface; and an etching step of supplying an etching liquid onto at least the first surface to selectively etch the first surface relative to the second surface.

[0013] According to the findings of the present inventors, by performing a silylation treatment to selectively form a water-repellent film on the Si(110) surface, it is possible to selectively increase the etching amount of the Si(100) surface compared to the etching amount of the Si(110) surface on which the water-repellent film has been selectively formed, i.e., the anisotropic etching selectivity of the Si(100) surface relative to the Si(110) surface is increased. Although the detailed mechanism is unclear, it is believed that selectively forming a water-repellent film can enhance the protective ability and / or water-repellent performance of the second surface including the Si(110) surface compared to the first surface including the Si(100) surface.

[0014] In this specification, the anisotropic etching selectivity is defined as [etching rate of Si(100) surface] / [etching rate of Si(110) surface]. Each etching rate is defined as the amount of etching (nm) per unit time (min). In this case, in the etching step of this embodiment, the etching selectivity of the first surface relative to the second surface, i.e., the lower limit of the anisotropic etching selectivity, is, for example, 2 or more, preferably 3 or more, and more preferably 4 or more. The upper limit of the anisotropic etching selectivity is not particularly limited, but may be 100 or less.

[0015] In this specification, the terms "protective film" and "water-repellent film" refer to both a compound having a silyl group derived from a silylating agent chemically bonded to a surface having Si elements, and a group of such compounds, regardless of whether or not the compounds interact with each other or are bonded. The water-repellent film may also contain a compound derived from a silylating agent physically bonded (adsorbed, attached, etc.) to the surface having silicon elements. The bond does not necessarily have to be direct, and may also be bonded via other elements, substituents, etc.

[0016] (Water repellency) In this specification, the water repellency is defined as the water contact angle obtained by the following measurement. Details of cleaning and drying before each measurement will be described later. First, the substrate was placed horizontally with the surface for measuring the contact angle facing up, and a 2 μl droplet of pure water was placed on the surface. In order to reduce the effect of the surface shape on the water contact angle, a substrate with a smooth surface on which the water droplet was placed was used. Next, in accordance with JIS R 3257:1999 "Test method for wettability of substrate glass surfaces," the temperature during measurement was set to room temperature (25° C.), and the angle between the water droplet and the substrate was measured using a contact angle meter (CA-X model, manufactured by Kyowa Interface Science Co., Ltd.), and the obtained value was defined as the water contact angle.

[0017] Each component of the method for manufacturing a semiconductor device according to this embodiment will be described in detail below.

[0018] An example of the method for manufacturing a semiconductor device according to this embodiment includes a preparation step, a silylation step, and an etching step. Each step will be described below with reference to FIGS. 1 to 6. FIGS. 1 to 6 are cross-sectional views that schematically illustrate each step.

[0019] (Preparation Step) In the preparation step, as shown in FIG. 1 , a substrate 1 is prepared which has a structure including a first surface 11 having a silicon single crystal plane orientation of (100), a second surface 12 having a silicon single crystal plane orientation of (110), and a silicon oxide-containing film 22 formed on the second surface 12.

[0020] The material of the substrate 1 is not particularly limited as long as it is a substrate used in a semiconductor manufacturing process, and may be made of, for example, silicon, silicon carbide, a plurality of components containing silicon element, sapphire, various compound semiconductors, etc. Furthermore, the substrate 1 may be, for example, a wafer.

[0021] The substrate 1 may have a relief structure (not shown) formed on the substrate surface. The relief structure may be, for example, a three-dimensional structure having one or more structures arranged along the vertical direction of the substrate 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, a memory device, a gate electrode, etc., such as a FinFET, a nanowire FET, a nanosheet FET, or other multi-gate FET, a three-dimensional memory cell, etc.

[0022] According to this embodiment, not only two-dimensional selective processing on a flat surface but also three-dimensional selective processing on a three-dimensional structure (three-dimensional film formation, three-dimensional etching, etc.) is possible.

[0023] The first surface 11 and the second surface 12 may be arranged along the planar direction of the substrate surface, or along the direction perpendicular to the substrate surface. The first surface 11 and the second surface 12 may be formed on the same plane or on different planes. For example, the first surface 11 may be arranged along the planar direction of the substrate surface, and the second surface 12 may be arranged perpendicular to the substrate surface. The first surface 11 and the second surface 12 may be formed adjacent to each other, or may be formed spaced apart from each other. The first surface 11 and the second surface 12 may each be composed of one region or two or more multiple regions. The multiple regions on each surface may be formed spaced apart from each other.

[0024] The first surface 11 and the second surface 12 may be the outermost surfaces of two different layers (first and second layers) of the substrate 1, or may be the outermost surfaces of the same layer of the substrate. The first surface 11 and the second surface 12 and the above-mentioned layers of the substrate 1 may or may not be composed of the same composition. "Not composed of the same composition" means, for example, that there is a difference in compositional components, such as (i) the first surface 11 or the second surface 12 containing the element O and the other surface not containing the element O, and / or (ii) there is a difference in compositional ratio, such as the content ratio of the element O of the first surface 11 or the second surface 12 being higher than the content ratio of the element O of the other layer.

[0025] The first surface 11 and the second surface 12 are formed by a single crystal structure of Si atoms with a plane orientation (100) and a plane orientation (110), respectively. However, the first surface 11 and the second surface 12 are allowed to contain other elements such as O atoms as long as the plane orientations are maintained.

[0026] The silicon oxide-containing film 22 is not particularly limited as long as it is a film containing Si and O. The stoichiometric ratio of Si and O in the silicon oxide-containing film is not limited to 1:1, and does not have to be an integer ratio. For example, SiO ２As shown in the figure, the ratio is 1:2. Specific examples of films containing silicon oxide include SiO films, SiCO films, and SiCOH films, with SiO films being preferred. The silicon oxide-containing film 22 may have a total content of Si atoms and O atoms of 80 mol % or more. The silicon oxide-containing film 22 may also contain other elements (C, H, P, B, etc.) within a range that does not adversely affect subsequent processes.

[0027] Furthermore, one or more dopants (e.g., P, N, B, Al, etc.) used for n-type source / drain or p-type source / drain may be contained in trace amounts in the first surface 11 and the second surface 12, and in the peripheral regions below the first surface 11 and the second surface 12. The dopants can affect the electrical properties when added in trace amounts relative to the Si element content, and therefore, it is presumed that the content of the dopants is sufficient to function as a dopant and therefore will not affect the silylation at the first surface 11 or the second surface 12.

[0028] The substrate 1 may further include a third surface and / or a fourth surface (not shown) on the substrate surface. The third surface contains Si and has a different chemical composition from the first surface 11 and the second surface 12. The fourth surface does not contain Si and is composed of, for example, amorphous carbon, elements such as W, Co, Al, Ni, Ru, Cu, Ti, and Ta, or compounds, oxides, or nitrides of these elements. The fourth surface may be a film surface of a high-k film. The third surface and the fourth surface may be adjacent to the first surface 11 and / or the second surface 12, respectively, or may be formed separately from each other. Furthermore, the third surface and the fourth surface may each be composed of one region or two or more regions.

[0029] In another embodiment, the above-described substrate preparation step may include an oxidation treatment to form a film 22 comprising silicon oxide on at least the exposed second surface 12 .

[0030] In yet another embodiment, the preparation step for preparing the above-mentioned substrate may include: an oxidation treatment for forming a first film containing silicon oxide (film 21 containing silicon oxide) and a second film containing silicon oxide (film 22 containing silicon oxide) on the exposed first surface 11 and the exposed second surface 12, respectively; and a selective removal treatment for removing the first film containing silicon oxide on the first surface 11 and leaving the second film containing silicon oxide on the second surface 12.

[0031] The oxidation treatment may include a treatment of contacting with a gaseous oxidizing agent or a treatment of contacting with a liquid oxidizing agent. Examples of treatments of contacting with a gaseous oxidizing agent include the following treatment A-2a, and examples of treatments of contacting with a liquid oxidizing agent include treatment A-2b. The oxidation treatment time may be 10 seconds or more, 1 minute or more, 2 minutes or more, 3 minutes or more, or 5 minutes or more, or may be 60 minutes or less, 40 minutes or less, or 20 minutes to 15 minutes or less. The oxidation treatment may newly form an OH group-containing region on at least the second surface 12, or on the first surface 11 and the second surface 12, or may form a film having OH groups (Si—OH film). The OH groups on each surface serve as reaction sites with the silylation agent in the subsequent silylation treatment.

[0032] In the treatment A-2a, an active species containing oxygen or an oxidizing agent in the form of a gas containing oxygen is brought into contact with at least the second surface 12, or with the first surface 11 and the second surface 12. As a specific method for the treatment A-2a, a known oxidation treatment used in a dry process can be suitably used, for example, a plasma treatment using a plasma containing oxygen, UV / O ３ and gas treatment involving exposure to a gas containing oxygen. Treatment A-2a is likely to oxidize Si-based surfaces, and therefore can form OH groups on each surface even if a native oxide film is formed on the surface.

[0033] The above plasma treatment may be carried out by a known method, for example, ３ Plasma treatment, O ２ Plasma treatment, CO ２ Plasma treatment, CO plasma treatment, NO２ Plasma treatment, NO plasma treatment, H ２ O plasma treatment. ３ The treatment involves irradiating ultraviolet light in an oxygen-gas-containing atmosphere such as the air to generate radicals containing oxygen elements, resulting in oxidation, and known treatment equipment can be used. The treatment conditions are not particularly limited, but are, for example, as follows: The ultraviolet light source may be any light source that emits ultraviolet light with a wavelength that can ozonize oxygen molecules, and examples thereof include a low-pressure mercury lamp and an excimer lamp. The output of the ultraviolet light is approximately 1 to 1,000 mW / cm. ２ Examples of the atmosphere include air, oxygen, a mixed gas of nitrogen and oxygen, a mixed gas of noble gas and oxygen, etc. As for the pressure, atmospheric pressure is acceptable, but in consideration of the ozone generation efficiency and the transmittance of ultraviolet light, an oxygen partial pressure of about 0.001 to 1 MPa is recommended. Examples of the temperature are about 10°C to 90°C. Examples of the gas used in the above gas treatment include, for example, O ３ , O ２ , CO ２ , H ２ O ２ For the purpose of efficient oxidation, heated gas may be used.

[0034] In the treatment A-2b, a liquid oxidizing agent containing oxygen is brought into contact with at least the second surface 12, or with the first surface 11 and the second surface 12. Examples of the liquid oxidizing agent include H ２ O ２ and / or ozone water. ２ O ２ The solution containing, for example, a cleaning agent (H ２ O ２ and ammonium hydroxide alkaline mixture (SC-1 liquid) and H ２ O ２ Acidic mixture of acetic acid and hydrochloric acid (SC-2 solution, etc.), ２ O ２ Examples include aqueous solutions. ２ O ２An example of the aqueous solution is an aqueous solution having a hydrogen peroxide concentration of 0.05 to 40% by mass. The specific contact method may be a known method, such as the same method as the silylation treatment described below. An example of the ozone water is an aqueous solution having an ozone concentration of 1 to 50 ppm by mass. The temperature at which the ozone water is contacted is, for example, 10 to 50°C. In addition, the H ２ O ２ The temperature at which the solution containing the compound is brought into contact with the substrate is, for example, 10 to 50°C. If necessary, treatment A-1 may be carried out before treatment A-2b to remove the native oxide film. Furthermore, treatments A-2a and A-2b may be combined.

[0035] Treatment A-1 is not particularly limited as long as it is a treatment capable of removing a native oxide film. Typically, a native oxide film forms on the surface of polysilicon, silicon oxide, or the like during the semiconductor manufacturing process. Treatment A-1 is preferable because it can remove this native oxide film. Treatment A-1 is not necessary for surfaces on which a native oxide film does not form, but may be performed as part of cleaning. Specific methods for treatment A-1 include, for example, contacting at least the second surface 12, or the first surface 11 and the second surface 12, with hydrogen fluoride (HF) or diluted hydrofluoric acid (DHF). Specific contacting methods may be known methods, such as the same method as the silylation treatment described below. After contact with hydrofluoric acid, a cleaning treatment using a cleaning agent described below may be performed.

[0036] The oxidation treatment is performed using UV / O ３ Processing, H ２ O ２ Treatment with a solution containing or ozone water is preferred.

[0037] As shown in Fig. 2, after the above-described oxidation treatment forms a film 21 containing silicon oxide on the first surface 11 and a film 22 containing silicon oxide on the second surface 12, it is preferable to remove the film 21 containing silicon oxide on the first surface 11 and leave the film 22 containing silicon oxide on the second surface 12 by a selective removal treatment. This results in a substrate 1 having the structure shown in Fig. 1. The film 21 containing silicon oxide does not have to be completely removed, and a portion of it may remain on the first surface 11.

[0038] The selective removal process may be performed using any solution capable of etching silicon oxide, but it is preferable to use a solution containing hydrogen fluoride. Although the detailed mechanism is unclear, the Si(100) surface and the Si(110) surface have different numbers of bonds to silicon oxide such as SiO, i.e., the densities of the silicon oxide-containing films are different, and therefore the frequency of contact with hydrogen fluoride differs between the two surfaces. This is thought to make the silicon oxide-containing film 21 on the first surface 11 of the Si(100) surface more susceptible to etching by hydrogen fluoride than the silicon oxide-containing film 22 on the second surface 12 of the Si(110) surface.

[0039] A specific example of the solution containing hydrogen fluoride is preferably one containing hydrogen fluoride and water, and may contain, for example, hydrofluoric acid, buffered hydrofluoric acid, hexafluorosilicic acid, or ammonium hexafluorosilicate. These may be used alone or in combination.

[0040] The concentration of hydrogen fluoride in the solution containing hydrogen fluoride is, for example, 0.01 to 10 mass %, preferably 0.02 to 5 mass %, more preferably 0.05 to 2 mass %, and even more preferably 0.1 to 1 mass %. Setting the concentration at or above the lower limit has the advantage of efficiently removing the silicon oxide-containing film 21. Setting the concentration at or below the upper limit has the advantage of allowing a sufficient amount of the silicon oxide-containing film 22 to remain. In this specification, the symbol "to" indicates that both the upper and lower limits are included, unless otherwise specified.

[0041] The solution containing hydrogen fluoride may contain an organic solvent such as alcohol to the extent that removal of the silicon oxide-containing film 21 is not practically hindered. The solution containing hydrogen fluoride may be substantially free of an oxidizing agent such as ozone water. "Substantially free of an oxidizing agent" means that the etching solution does not contain an oxidizing agent, or that the content of the oxidizing agent in the etching solution is 1% by mass or less. The content of the oxidizing agent in the etching solution may be 0.5% by mass or less, 0.1% by mass or less, 0.05% by mass or less, or 0.01% by mass or less. Furthermore, taking into consideration the manufacturing process of a semiconductor device, the solution containing hydrogen fluoride preferably does not contain alkali metal hydroxides or alkaline earth metal hydroxides. "Free of alkali metal hydroxides or alkaline earth metal hydroxides" means that the etching solution does not contain alkali metal hydroxides or alkaline earth metal hydroxides, or that the content of alkali metal hydroxides or alkaline earth metal hydroxides in the etching solution is 100 ppm by mass or less. The content of the oxidizing agent in the etching solution may be 10 ppm by mass or less, 1 ppm by mass or less, 100 ppb by mass or less, 10 ppb by mass or less, or 1 ppb by mass or less.

[0042] 3 and 4 , after the above preparation step, the silylation step is a silylation treatment in which a silylating agent is supplied onto at least the second surface 12, or onto the first surface 11 and the second surface 12, to selectively form a water-repellent film 32 with respect to the silicon oxide-containing film 22 on the second surface 12. The silylation agent 30 may be supplied so as to come into contact with at least the surface of the silicon oxide-containing film 22 on the second surface 12, or may be supplied so as to come into contact with the surface of the first surface 11 and the surface of the silicon oxide-containing film 22 on the second surface 12.

[0043] The silylation treatment can improve the water repellency of at least the second surface 12. That is, the silylation treatment improves the water repellency by forming a structure on the second surface 12 in which silyl groups derived from the silylating agent are chemically bonded to OH groups in the silicon oxide-containing film 22 on the second surface 12, i.e., a water-repellent film 32. A water-repellent film may also be formed on the first surface 11 in a similar manner, and even if a water-repellent film is not formed, the water repellency may be improved by having a structure in which a compound derived from the silylating agent is physically bonded (e.g., attached or adsorbed) to the surface.

[0044] Although the detailed mechanism is unclear, the silylation agent converts Si—OH groups present in the silicon oxide-containing film 22 on the second surface 12 into silyl groups such as trimethylsilyl groups, thereby forming a protective layer (water-repellent layer) on the surface, but it is difficult to form a protective layer (water-repellent layer) on the first surface 11. For this reason, while bonding / adhesion of the silylation agent progresses on the surface of the silicon oxide-containing film 22 on the second surface 12, a protective layer (water-repellent layer) is not formed on the first surface 11, and even if it is formed, its density is relatively low. In other words, it can be inferred that the density of the water-repellent film 32 on the second surface 12 is increased compared to the state of the first surface 11 after the silylation treatment.

[0045] In the silylation treatment, the silylating agent 30 may be used alone, or a silylation composition containing the silylating agent 30 and a solvent or diluent gas, or a silylation composition containing the silylating agent 30 and a catalytic compound, and if necessary, a solvent or diluent gas, may be used. The silylation agent 30 and the silylation composition containing the silylation composition 30 may be used in either a liquid or gas state.

[0046] In the case of a wet process, a liquid of the silylation agent 30 or a silylation composition containing the silylation agent 30 may be supplied to the first surface 11 and the second surface 12. A known supply method can be used, and examples of the supply method include a single-wafer method such as spin coating when supplying in a liquid state, and a batch method such as immersion. Furthermore, when supplying in a vapor state and turning into a liquid after contact with the first surface 11 and the second surface 12, a known vapor injection method can be used.

[0047] In the case of a dry process, the silylation agent 30 may be supplied as a gas to the first surface 11 and the second surface 12. A known method can be used for supplying the silylation agent 30, for example, a method in which the silylation agent 30 is gasified in advance using a vaporizer or the like and then supplied; ２ For example, two or more kinds of gases may be supplied simultaneously or may be mixed in advance and supplied.

[0048] The silylation step may optionally include a cleaning treatment in which at least a portion of each surface is cleaned using a cleaning agent. When at least a portion of each treatment is performed using a wet process, one or more cleaning treatments may be performed between each treatment. In the case of multiple cleaning treatments, the type of cleaning agent may be changed for each treatment.

[0049] The cleaning material may include an aqueous cleaning solution and / or a rinse solution.

[0050] The aqueous cleaning solution is not particularly limited as long as it does not remove the water-repellent film 32 formed on the silicon oxide-containing film 22 on the second surface 12. Examples include water, alcohol, an aqueous hydrogen peroxide solution, and ozone water. These may be used alone or in combination of two or more.

[0051] Like the aqueous cleaning solution, the rinse solution is not particularly limited as long as it does not remove the water-repellent film 32 formed on the silicon oxide-containing film 22 on the second surface 12. The rinse solution may use a cleaning agent different from that used in 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 rinse solution include hydrocarbons, esters, ethers, ketones, halogen-containing solvents, sulfoxide-based solvents, alcohols, polyhydric alcohol derivatives, and nitrogen-containing solvents. Among these, it is preferable to use at least one organic solvent selected from alcohols having 3 or fewer carbon atoms, such as methanol, 1-propanol, and 2-propanol (isopropanol).

[0052] In this embodiment, the method of contacting the cleaning agent is not particularly limited, but examples thereof include immersion, application methods such as spin coating and spray coating, and vapor contact.

[0053] The silylation step may be subjected to a drying treatment as necessary. When at least a part of each treatment is performed by a wet process, one or more drying treatments may be performed between each treatment.

[0054] By the above silylation step, the substrate 1 shown in FIG. 4 is obtained, which has a water-repellent film 32 (protective film) formed on the silicon oxide-containing film 22 on the second surface 12 .

[0055] Furthermore, when the first surface 11 is arranged in the planar direction of the substrate surface and the second surface 12 is arranged in a direction perpendicular to the substrate surface, a substrate 1 having the structure shown in Fig. 5 is obtained. The structure of the substrate 1 may have the above-mentioned three-dimensional structure as shown in Fig. 5, or may have a plate-like structure.

[0056] 4 or 5 has a structure including: a first surface 12 having a (100) plane orientation of the silicon single crystal; a second surface 12 having a (110) plane orientation; a silicon oxide-containing film 22 formed on the second surface 12; and a water-repellent film 32 formed on the silicon oxide-containing film 22 on the second surface 12. The water-repellent film 32 may be configured as a film that covers at least a part or the entire second surface 12. A water-repellent film (not shown) may also be formed on the first surface 11, but it is not necessarily required that a water-repellent film be formed.

[0057] (Etching Step) In the etching step, after the silylation step, an etching solution is supplied onto at least the first surface 11, as shown in Fig. 6, so that the first surface 11 can be selectively etched relative to the second surface 12. Although the detailed mechanism is not clear, it is thought that because the second surface 12 is protected by the relatively dense water-repellent film 32, etching by the etching solution proceeds selectively on the first surface 11. After the etching step, a portion of the first surface 11 may remain.

[0058] In this embodiment, the water contact angle on the first surface 11 immediately after the step of preparing the substrate is expressed as CA １Ｘ , the water contact angle on the second surface 12 is CA ２Ｘ , the water contact angle on the first surface 11 immediately after the silylation step is CA １Ｙ , the water contact angle on the second surface 12 is CA ２Ｙ Before the etching process, |CA １Ｙ -CA １Ｘ |<|CA ２Ｙ -CA ２Ｘ It is preferable that |CA １Ｙ -CA １Ｘ | is 29° or less and |CA ２Ｙ -CA ２Ｘ It is preferable that | is 30° or more. １Ｙ -CA １Ｘ The upper limit of | is, for example, 29° or less, preferably 27° or less, and more preferably 25° or less. １Ｙ -CA １Ｘ The lower limit of | is not particularly limited, but may be 0° or more, or 1° or more. ２Ｙ -CA ２Ｘ The lower limit of | is, for example, 30° or more, preferably 33° or more, and more preferably 35° or more. ２Ｙ -CA ２Ｘ The upper limit of | is not particularly limited, but may be 80° or less, or 75° or less.

[0059] | CA １Ｙ -CA １Ｘ | is relatively small and |CA ２Ｙ -CA ２Ｘ A relatively high | is an indicator that, as a result of the silylation step, a dense water-repellent film 32 has been formed on the second surface 12, while a dense water-repellent film 32 has not been formed on the first surface 11. By utilizing this indicator, it is possible to stably improve the etching selectivity of the first surface 11 relative to the second surface 12 in the etching treatment in the next step.

[0060] The etching solution can be selected from those capable of etching silicon single crystals, and preferably contains, for example, a quaternary ammonium hydroxide. The etching time may be 10 seconds or more, 1 minute or more, 2 minutes or more, 3 minutes or more, or 5 minutes or more, or 60 minutes or less, 40 minutes or less, or 20 minutes to 15 minutes or less.

[0061] Quaternary ammonium hydroxide is NR ４ OH (wherein R is a hydrogen atom or an alkyl group). Specific examples of the quaternary ammonium hydroxide include ammonium hydroxide and tetramethylammonium hydroxide. The content of the quaternary ammonium hydroxide in the etching solution is, for example, 0.01 to 2.0 mass%, preferably 0.02 to 1.0 mass%, and more preferably 0.1 to 0.5 mass%.

[0062] The etching solution is preferably substantially free of an oxidizing agent. "Substantially free of an oxidizing agent" means that the etching solution does not contain an oxidizing agent or the content of the oxidizing agent in the etching solution is 1% by mass or less. The content of the oxidizing agent in the etching solution may be 0.5% by mass or less, 0.1% by mass or less, 0.05% by mass or less, or 0.01% by mass or less. Examples of the oxidizing agent include hydrogen peroxide, FeCl ３ , FeF ３ , Fe(NO ３ ) ３ , Sr(NO ３ ) ２ , CoF ３ , MnF ３ , Oxone (2KHSO ５ ・KHSO ４ ・K ２ SO ４), periodic acid, iodic acid, vanadium (V) oxide, vanadium (IV, V) oxide, ammonium vanadate, ammonium peroxomonosulfate, ammonium chlorite, ammonium chlorate, ammonium iodate, ammonium nitrate, ammonium perborate, ammonium perchlorate, ammonium periodate, ammonium persulfate, ammonium hypochlorite, ammonium hypobromite, ammonium tungstate, sodium persulfate, sodium hypochlorite, sodium perborate, sodium hypobromite, potassium iodate, potassium permanganate, potassium persulfate, nitric acid, potassium persulfate, potassium hypochlorite, tetramethylammonium chlorite, chloric acid Examples of the solvent include tetramethylammonium, tetramethylammonium iodate, tetramethylammonium perborate, tetramethylammonium perchlorate, tetramethylammonium periodate, tetramethylammonium persulfate, tetrabutylammonium peroxomonosulfate, peroxomonosulfuric acid, ferric nitrate, urea peroxide, peracetic acid, methyl-1,4-benzoquinone (MBQ), 1,4-benzoquinone (BQ), 1,2-benzoquinone, 2,6-dichloro-1,4-benzoquinone (DCBQ), toluquinone, 2,6-dimethyl-1,4-benzoquinone (DMBQ), chloranil, alloxan, N-methylmorpholine N-oxide, and trimethylamine N-oxide.

[0063] In the manufacturing method of this embodiment, a cycle including a silylation step and an etching step, or a cycle including an oxidation treatment step, a silylation step and an etching step may be repeated once or twice or more times. Between cycles, one or more known treatments such as the above-mentioned cleaning treatment may be performed.

[0064] After the etching step, if the water-repellent film 32 formed on the second surface 12 is no longer needed, the water-repellent film 32 may be removed. The removal method is not particularly limited as long as it is a known method capable of removing silylated groups. Examples include light (ultraviolet) irradiation, heat treatment, ozone exposure, plasma irradiation, and corona discharge. Removal by a wet process is also possible, such as contact with an ammonium hydroxide aqueous solution, a tetramethylammonium aqueous solution, a hydrochloric acid aqueous solution, or a sulfuric acid aqueous solution.

[0065] The method for manufacturing a semiconductor device according to the present embodiment includes the steps of obtaining a substrate that has been subjected to the steps in the method for manufacturing a semiconductor device described above. By the method for manufacturing a semiconductor device, desired semiconductor wafers and semiconductor devices can be obtained.

[0066] <Silylation Agent> The silylation agent and the silylation composition containing the silylation agent used in the silylation treatment in the method for manufacturing a semiconductor device described above will now be described. The silylation composition is used to form a water-repellent film on the silicon oxide-containing film formed on the second surface having a (110) plane orientation.

[0067] Known silylating agents can be used as the silylating agent. Examples of the silylating agent include silicon compounds represented by the following general formula [1]. These may be used alone or in combination of two or more kinds. When two or more kinds are combined, they are sometimes referred to as a "silylated composition." Furthermore, the silicon compound contained in the above silylated composition is represented by R １ may have the same number of carbon atoms or different numbers of carbon atoms.

[0068] R １ ａ Si(H) ｂ X ４－ａ－ｂ [1]

[0069] In the above general formula [1], R １are each independently an organic group containing a hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms; each X is independently a monovalent organic group in which the element bonded to the Si atom is nitrogen, oxygen, carbon, or halogen; a is an integer of 1 to 3; b is an integer of 0 to 2; and the sum of a and b is 1 to 3.

[0070] R in the above general formula [1] １ may contain not only hydrogen, carbon, nitrogen, oxygen, and fluorine elements, but also silicon, sulfur, and halogen elements (other than fluorine). １ R in the above general formula [1] may contain an unsaturated bond, an aromatic ring, or a cyclic structure. １ For example, each independently represents C ｅ H ２ｅ＋１ (e=1 to 18), and C ｆ F ２ｆ＋１ CH ２ CH ２ (f=1 to 8). Among these, it is particularly preferable to use a silicon compound having a trialkylsilyl group. １ When R contains a silicon element, the general formula [1] may have a structure represented by the following general formula [1-1]: １ ｍ X ３－ｍ－ｎ (H) ｎ Si-(CH ２ ) ｐ -Si(H) ｎ X ３－ｍ－ｎ R １ ｍ [1-1] In the above general formula [1-1], R １ (However, this R １ does not contain silicon element) and X are the same as those in the above general formula [1], m is an integer of 1 to 2, n is an integer of 0 to 1, the sum of m and n is 1 to 2, p is an integer of 1 to 18, and -(CH ２ ) ｐ The methylene chain represented by - may be substituted with a halogen.

[0071] In X in the general formula [1], the monovalent organic group in which the element bonded to the Si element is nitrogen, oxygen, or carbon may contain not only hydrogen, carbon, nitrogen, or oxygen elements, but also silicon, sulfur, a halogen element, etc. Examples of the monovalent organic group in which the element bonded to the Si element is nitrogen include, for example, an isocyanate group, an amino group, a dialkylamino group, an isothiocyanate group, an azide group, an acetamide group, and -NHC(=O)CF ３ , -N(CH ３ )C(=O)CH ３ , -N(CH ３ )C(=O)CF ３ , -N=C(CH ３ )OSi(CH ３ ) ３ , -N=C(CF ３ )OSi(CH ３ ) ３ , -NHC(=O)-OSi(CH ３ ) ３ , -NHC(=O)-NH-Si(CH ３ ) ３ , an imidazole ring, a triazole ring, a tetrazole ring, an oxazolidinone ring, a morpholine ring, —NH—C(═O)—Si(CH ３ ) ３ , -N(S(=O) ２ R ４ ) ２ (where R ４ are each independently a group selected from the group consisting of a monovalent hydrocarbon group having 1 to 8 carbon atoms, in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and fluorine atoms), and a substituent having a structure of the following general formula [1-2] (In the above general formula [1-2], R ５ are each independently a divalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms), -N=C(NR ６ ２ ) ２ , -N=C(NR ６ ２ ) R ６ (where R ６ are each independently a hydrogen group, a —C≡N group, or —NO ２and a hydrocarbon group in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and the hydrocarbon group may have an oxygen atom and / or a nitrogen atom. ａ１ ) (R ａ２ ) (wherein the above R ａ１ represents a hydrogen atom or a saturated or unsaturated alkyl group, and R ａ２ represents a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, or a saturated or unsaturated heterocycloalkyl group. ａ１ and R ａ２ may be bonded to each other to form a saturated or unsaturated heterocycloalkyl group having a nitrogen atom. ａ３ )-Si(R ａ４ ) (R ａ５ ) (R ａ６ ) (wherein the above R ａ３ represents a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, a trimethylsilyl group, or a dimethylsilyl group, and ａ４ , R ａ５ and R ａ６ each independently represents a hydrogen atom or an organic group, R ａ４ , R ａ５ and R ａ６ The total number of carbon atoms contained in —N(R ａ７ )-C(=O)R ａ８ (Here, the above R ａ７ represents a hydrogen atom, a methyl group, a trimethylsilyl group, or a dimethylsilyl group, and R ａ８ represents a hydrogen atom, a saturated or unsaturated alkyl group, a fluorine-containing alkyl group, or a trialkylsilylamino group.

[0072] Examples of the silylating agent in which X in the general formula [1] is a monovalent organic group in which the element bonded to the Si element is nitrogen include CH ３ Si(NH ２ ) ３ , C ２ H ５ Si(NH ２ ) ３ , C ３ H ７ Si(NH ２ ) ３C ４ H ９ Si(NH) ２ ) ３ C ５ H １１ Si(NH) ２ ) ３ C ６ H １３ Si(NH) ２ ) ３ C ７ H １５ Si(NH) ２ ) ３ C ８ H １７ Si(NH) ２ ) ３ C ９ H １９ Si(NH) ２ ) ３ C １０ H ２１ Si(NH) ２ ) ３ C １１ H ２３ Si(NH) ２ ) ３ C １２ H ２５ Si(NH) ２ ) ３ C １３ H ２７ Si(NH) ２ ) ３ C １４ H ２９ Si(NH) ２ ) ３ C １５ H ３１ Si(NH) ２ ) ３ C １６ H ３３ Si(NH) ２ ) ３ C １７ H ３５ Si(NH) ２ ) ３ C １８ H ３７ Si(NH) ２ ) ３ (CH) ３ ) ２ Si(NH) ２ ) ２ C ２ H５ Si(CH) ３ (NH ２ ) ２ (C) ２ H ５ ) ２ Si(NH) ２ ) ２ C ３ H ７ Si(CH) ３ (NH ２ ) ２ (C) ３ H ７ ) ２ Si(NH) ２ ) ２ C ４ H ９ Si(CH) ３ (NH ２ ) ２ (C) ４ H ９ ) ２ Si(NH) ２ ) ２ C ５ H １１ Si(CH) ３ (NH ２ ) ２ C ６ H １３ Si(CH) ３ (NH ２ ) ２ C ７ H １５ Si(CH) ３ (NH ２ ) ２ C ８ H １７ Si(CH) ３ (NH ２ ) ２ C ９ H １９ Si(CH) ３ (NH ２ ) ２ C １０ H ２１ Si(CH) ３ (NH ２ ) ２ C １１ H ２３ Si(CH) ３ (NH ２ ) ２ C１２ H ２５ Si(CH) ３ (NH ２ ) ２ C １３ H ２７ Si(CH) ３ (NH ２ ) ２ C １４ H ２９ Si(CH) ３ (NH ２ ) ２ C １５ H ３１ Si(CH) ３ (NH ２ ) ２ C １６ H ３３ Si(CH) ３ (NH ２ ) ２ C １７ H ３５ Si(CH) ３ (NH ２ ) ２ C １８ H ３７ Si(CH) ３ (NH ２ ) ２ (CH) ３ ) ３ Sinh ２ C ２ H ５ Si(CH) ３ ) ２ NH ２ (C) ２ H ５ ) ２ Si(CH) ３ )NH ２ (C) ２ H ５ ) ３ Sinh ２ C ３ H ７ Si(CH) ３ ) ２ NH ２ (C) ３ H ７ ) ２ Si(CH) ３ )NH ２ (C) ３ H ７ ) ３Sinh ２ C ４ H ９ Si(CH) ３ ) ２ NH ２ (C) ４ H ９ ) ３ Sinh ２ C ５ H １１ Si(CH) ３ ) ２ NH ２ C ６ H １３ Si(CH) ３ ) ２ NH ２ C ７ H １５ Si(CH) ３ ) ２ NH ２ C ８ H １７ Si(CH) ３ ) ２ NH ２ C ９ H １９ Si(CH) ３ ) ２ NH ２ C １０ H ２１ Si(CH) ３ ) ２ NH ２ C １１ H ２３ Si(CH) ３ ) ２ NH ２ C １２ H ２５ Si(CH) ３ ) ２ NH ２ C １３ H ２７ Si(CH) ３ ) ２ NH ２ C １４ H ２９ Si(CH) ３ ) ２ NH ２ C １５ H ３１ Si(CH) ３ ) ２ NH ２ C１６ H ３３ Si(CH) ３ ) ２ NH ２ C １７ H ３５ Si(CH) ３ ) ２ NH ２ C １８ H ３７ Si(CH) ３ ) ２ NH ２ (CH) ３ ) ２ Si(H)NH ２ CH ３ Si(H) ２ NH ２ (C) ２ H ５ ) ２ Si(H)NH ２ C ２ H ５ Si(H) ２ NH ２ C ２ H ５ Si(CH) ３ )(H)NH ２ (C) ３ H ７ ) ２ Si(H)NH ２ C ３ H ７ Si(H) ２ NH ２ CF ３ CH ２ CH ２ Si(NH) ２ ) ３ C ２ F ５ CH ２ CH ２ Si(NH) ２ ) ３ C ３ F ７ CH ２ CH ２ Si(NH) ２ ) ３ C ４ F ９ CH ２ CH ２ Si(NH) ２ ) ３ C５ F １１ CH ２ CH ２ Si(NH) ２ ) ３ C ６ F １３ CH ２ CH ２ Si(NH) ２ ) ３ C ７ F １５ CH ２ CH ２ Si(NH) ２ ) ３ C ８ F １７ CH ２ CH ２ Si(NH) ２ ) ３ CF ３ CH ２ CH ２ Si(CH) ３ (NH ２ ) ２ C ２ F ５ CH ２ CH ２ Si(CH) ３ (NH ２ ) ２ C ３ F ７ CH ２ CH ２ Si(CH) ３ (NH ２ ) ２ C ４ F ９ CH ２ CH ２ Si(CH) ３ (NH ２ ) ２ C ５ F １１ CH ２ CH ２ Si(CH) ３ (NH ２ ) ２ C ６ F １３ CH ２ CH ２ Si(CH) ３ (NH ２ ) ２ C７ F １５ CH ２ CH ２ Si(CH) ３ (NH ２ ) ２ C ８ F １７ CH ２ CH ２ Si(CH) ３ (NH ２ ) ２ CF ３ CH ２ CH ２ Si(CH) ３ ) ２ NH ２ C ２ F ５ CH ２ CH ２ Si(CH) ３ ) ２ NH ２ C ３ F ７ CH ２ CH ２ Si(CH) ３ ) ２ NH ２ C ４ F ９ CH ２ CH ２ Si(CH) ３ ) ２ NH ２ C ５ F １１ CH ２ CH ２ Si(CH) ３ ) ２ NH ２ C ６ F １３ CH ２ CH ２ Si(CH) ３ ) ２ NH ２ C ７ F １５ CH ２ CH ２ Si(CH) ３ ) ２ NH ２ C ８ F １７ CH ２ CH ２Si(CH ３ ) ２ NH ２ , C.F. ３ CH ２ CH ２ Si(CH ３ ) (H) NH ２ , aminodimethylvinylsilane, aminodimethylphenylethylsilane, aminodimethylphenylsilane, aminomethyldiphenylsilane, aminodimethyl-t-butylsilane, etc. ２ group), -N=C=O, dialkylamino group (-N(CH ３ ) ２ , -N(C ２ H ５ ) ２ etc.), t-butylamino group, allylamino group, -N=C=S, -N ３ , -NHC(=O)CH ３ , -NHC(=O)CF ３ , -N(CH ３ )C(=O)CH ３ , -N(CH ３ )C(=O)CF ３ , -N=C(CH ３ )OSi(CH ３ ) ３ , -N=C(CF ３ )OSi(CH ３ ) ３ , -NHC(=O)-OSi(CH ３ ) ３ , -NHC(=O)-NH-Si(CH ３ ) ３ (e.g., N,N'-bis(trimethylsilyl)urea, etc.), imidazole ring (e.g., N-trimethylsilylimidazole, etc.), triazole ring (e.g., N-trimethylsilyltriazole, etc.), tetrazole ring, oxazolidinone ring, morpholine ring, —NH—C(═O)—Si(CH ３ ) ３ , -N(S(=O) ２ R ４ ) ２ (where R ４are each independently a group selected from the group consisting of a monovalent hydrocarbon group having 1 to 8 carbon atoms, in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and fluorine atoms. For example, N-(trimethylsilyl)bis(trifluoromethanesulfonyl)imide, etc.), and a substituent having a structure of the following general formula [1-2]: (In the above general formula [1-2], R ５ are each independently a divalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms. Examples include N-(trimethylsilyl)N,N-difluoromethane-1,3-bis(sulfonyl)imide, -N=C(NR ６ ２ ) ２ , -N=C(NR ６ ２ ) R ６ (where R ６ are each independently a hydrogen group, a —C≡N group, or —NO ２ and hydrocarbon groups in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and the hydrocarbon groups may have oxygen atoms and / or nitrogen atoms. For example, 2-trimethylsilyl-1,1,3,3-tetramethylguanidine, -N(R ａ１ ) R ａ２ (Here, the above R ａ１ represents a hydrogen atom or a saturated or unsaturated alkyl group, and R ａ２ represents a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, or a saturated or unsaturated heterocycloalkyl group. ａ１ and R ａ２ may be bonded to each other to form a saturated or unsaturated heterocycloalkyl group having a nitrogen atom. ａ３ )-Si(R ａ４ ) (R ａ５ ) (R ａ６ ) (wherein the above R ａ３ represents a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, a trimethylsilyl group, or a dimethylsilyl group, and ａ４ , R ａ５ and R ａ６ each independently represents a hydrogen atom or an organic group, Rａ４ , R ａ５ and R ａ６ is 1 or more. For example, hexamethyldisilazane, N-methylhexamethyldisilazane, 1,1,3,3-tetramethyldisilazane, 1,3-dimethyldisilazane, 1,3-di-N-octyltetramethyldisilazane, 1,3-divinyltetramethyldisilazane, heptamethyldisilazane, N-allyl-N,N-bis(trimethylsilyl)amine, 1,3-diphenyltetramethyldisilazane, and 1,1,3,3-tetraphenyl-1,3-dimethyldisilazane, nonamethyltrisilazane, pentamethylethyldisilazane, pentamethylvinyldisilazane, pentamethylpropyldisilazane, pentamethylethyldisilazane, pentamethyl-t-butyldisilazane, pentamethylphenyldisilazane, trimethyltriethyldisilazane, and the like.), -N(R ａ７ )-C(=O)R ａ８ (Here, the above R ａ７ represents a hydrogen atom, a methyl group, a trimethylsilyl group, or a dimethylsilyl group, and R ａ８ represents a hydrogen atom, a saturated or unsaturated alkyl group, a fluorine-containing alkyl group, or a trialkylsilylamino group. Examples of such groups include N-trimethylsilylacetamide, N-trimethylsilyltrifluoroacetamide, N-methyl-N-trimethylsilylacetamide, N-methyl-N-trimethylsilyltrifluoroacetamide, bis(trimethylsilyl)acetamide, and bis(trimethylsilyl)trifluoroacetamide.

[0073] Examples of the silylating agent in which X in the general formula [1] is a monovalent organic group in which the element bonded to the Si element is oxygen include the amino group (—NH ２ group) by —O—C(═A)R ａ９ (wherein A is O, CHR ａ１０ , CHOR ａ１０ , C.R. ａ１０ R ａ１０ , or NR ａ１１ indicates R ａ９ , R ａ１０each independently represents a hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, a fluorine-containing alkyl group, a chlorine-containing alkyl group, a trialkylsilyl group, a trialkylsiloxy group, an alkoxy group, a phenyl group, a phenylethyl group, or an acetyl group, and ａ１１ represents a hydrogen atom, an alkyl group, or a trialkylsilyl group. Examples include trimethylsilyl acetate, dimethylsilyl acetate, monomethylsilyl acetate, trimethylsilyl trifluoroacetate, dimethylsilyl trifluoroacetate, monomethylsilyl trifluoroacetate, trimethylsilyl trichloroacetate, trimethylsilyl propionate, and trimethylsilyl butyrate.), —O—C(R ａ１２ ) = N(R ａ１３ ) (wherein the above R ａ１２ represents a hydrogen atom, a saturated or unsaturated alkyl group, a fluorine-containing alkyl group, or a trialkylsilylamino group, and R ａ１３ represents a hydrogen atom, an alkyl group, or a trialkylsilyl group.), —O—C(R ａ１４ )=CH-C(=O)R ａ１５ (Here, the above R ａ１４ and R ａ１５ each independently represents a hydrogen atom or an organic group. For example, trimethylsilyloxy-3-penten-2-one, 2-trimethylsiloxypent-2-en-4-one, etc.), —OR ａ１６ (Here, the above R ａ１６ represents a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, or a fluorine-containing alkyl group. ａ１６ Examples of the silylating agent having the formula: ３ Si(OCH ３ ) ３ , C ２ H ５ Si(OCH ３ ) ３ , C ３ H ７ Si(OCH ３ ) ３ , C ４ H ９ Si(OCH ３ ) ３ , C ５H １１ Si(OCH ３ ) ３ 、C ６ H １３ Si(OCH ３ ) ３ 、C ７ H １５ Si(OCH ３ ) ３ 、C ８ H １７ Si(OCH ３ ) ３ 、C ９ H １９ Si(OCH ３ ) ３ 、C １０ H ２１ Si(OCH ３ ) ３ 、C １１ H ２３ Si(OCH ３ ) ３ 、C １２ H ２５ Si(OCH ３ ) ３ 、C １３ H ２７ Si(OCH ３ ) ３ 、C １４ H ２９ Si(OCH ３ ) ３ 、C １５ H ３１ Si(OCH ３ ) ３ 、C １６ H ３３ Si(OCH ３ ) ３ 、C １７ H ３５ Si(OCH ３ ) ３ 、C １８ H ３７ Si(OCH ３ ) ３ ,(H ３ ) ２ Si(OCH ３ ) ２ 、C ２ H ５ Si(H) ３ )(OCH ３ ) ２ 、(C２ H ５ ) ２ Si(OCH ３ ) ２ 、C ３ H ７ Si(H) ３ )(OCH ３ ) ２ 、(C ３ H ７ ) ２ Si(OCH ３ ) ２ 、C ４ H ９ Si(H) ３ )(OCH ３ ) ２ 、(C ４ H ９ ) ２ Si(OCH ３ ) ２ 、C ５ H １１ Si(H) ３ )(OCH ３ ) ２ 、C ６ H １３ Si(H) ３ )(OCH ３ ) ２ 、C ７ H １５ Si(H) ３ )(OCH ３ ) ２ 、C ８ H １７ Si(H) ３ )(OCH ３ ) ２ 、C ９ H １９ Si(H) ３ )(OCH ３ ) ２ 、C １０ H ２１ Si(H) ３ )(OCH ３ ) ２ 、C １１ H ２３ Si(H) ３ )(OCH ３ ) ２ 、C １２ H ２５ Si(H) ３ )(OCH ３) ２ 、C １３ H ２７ Si(H) ３ )(OCH ３ ) ２ 、C １４ H ２９ Si(H) ３ )(OCH ３ ) ２ 、C １５ H ３１ Si(H) ３ )(OCH ３ ) ２ 、C １６ H ３３ Si(H) ３ )(OCH ３ ) ２ 、C １７ H ３５ Si(H) ３ )(OCH ３ ) ２ 、C １８ H ３７ Si(H) ３ )(OCH ３ ) ２ ,(H ３ ) ３ SiOCH ３ 、C ２ H ５ Si(H) ３ ) ２ OCH ３ 、(C ２ H ５ ) ２ Si(H) ３ )OCH ３ 、(C ２ H ５ ) ３ SiOCH ３ 、C ３ H ７ Si(H) ３ ) ２ OCH ３ 、(C ３ H ７ ) ２ Si(H) ３ )OCH ３ 、(C ３ H ７ ) ３ SiOCH ３ 、C ４ H ９Si(H) ３ ) ２ OCH ３ 、(C ４ H ９ ) ３ SiOCH ３ 、C ５ H １１ Si(H) ３ ) ２ OCH ３ 、C ６ H １３ Si(H) ３ ) ２ OCH ３ 、C ７ H １５ Si(H) ３ ) ２ OCH ３ 、C ８ H １７ Si(H) ３ ) ２ OCH ３ 、C ９ H １９ Si(H) ３ ) ２ OCH ３ 、C １０ H ２１ Si(H) ３ ) ２ OCH ３ 、C １１ H ２３ Si(H) ３ ) ２ OCH ３ 、C １２ H ２５ Si(H) ３ ) ２ OCH ３ 、C １３ H ２７ Si(H) ３ ) ２ OCH ３ 、C １４ H ２９ Si(H) ３ ) ２ OCH ３ 、C １５ H ３１ Si(H) ３ ) ２ OCH ３ 、C １６ H ３３ Si(H)３ ) ２ OCH ３ , C １７ H ３５ Si(CH ３ ) ２ OCH ３ , C １８ H ３７ Si(CH ３ ) ２ OCH ３ , (CH ３ ) ２ Si(H)OCH ３ , CH ３ Si(H) ２ OCH ３ , (C ２ H ５ ) ２ Si(H)OCH ３ , C​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​３ ) ３ 、C ６ F １３ CH ２ CH ２ Si(OCH ３ ) ３ 、C ７ F １５ CH ２ CH ２ Si(OCH ３ ) ３ 、C ８ F １７ CH ２ CH ２ Si(OCH ３ ) ３ 、CF ３ CH ２ CH ２ Si(H) ３ )(OCH ３ ) ２ 、C ２ F ５ CH ２ CH ２ Si(H) ３ )(OCH ３ ) ２ 、C ３ F ７ CH ２ CH ２ Si(H) ３ )(OCH ３ ) ２ 、C ４ F ９ CH ２ CH ２ Si(H) ３ )(OCH ３ ) ２ 、C ５ F １１ CH ２ CH ２ Si(H) ３ )(OCH ３ ) ２ 、C ６ F １３ CH ２ CH ２ Si(H) ３ )(OCH ３ ) ２ 、C ７ F １５ CH ２ CH ２Si(H) ３ )(OCH ３ ) ２ 、C ８ F １７ CH ２ CH ２ Si(H) ３ )(OCH ３ ) ２ 、CF ３ CH ２ CH ２ Si(H) ３ ) ２ OCH ３ 、C ２ F ５ CH ２ CH ２ Si(H) ３ ) ２ OCH ３ 、C ３ F ７ CH ２ CH ２ Si(H) ３ ) ２ OCH ３ 、C ４ F ９ CH ２ CH ２ Si(H) ３ ) ２ OCH ３ 、C ５ F １１ CH ２ CH ２ Si(H) ３ ) ２ OCH ３ 、C ６ F １３ CH ２ CH ２ Si(H) ３ ) ２ OCH ３ 、C ７ F １５ CH ２ CH ２ Si(H) ３ ) ２ OCH ３ 、C ８ F １７ CH ２ CH ２ Si(H) ３ ) ２ OCH ３, C.F. ３ CH ２ CH ２ Si(CH ３ ) (H) OCH ３ or a compound in which the methyl group moiety of the methoxy group of the above methoxysilane is replaced with a monovalent hydrocarbon group having 2 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced with fluorine atoms), —O—S(═O) ２ -R ａ１７ (Here, the above R ａ１７ represents an alkyl group having 1 to 6 carbon atoms, a perfluoroalkyl group, a phenyl group, a tolyl group, —O—Si(CH ３ ) ３ For example, trimethylsilyl sulfonate, trimethylsilyl benzene sulfonate, trimethylsilyl toluene sulfonate, trimethylsilyl trifluoromethane sulfonate, trimethylsilyl perfluorobutane sulfonate, bistrimethylsilyl sulfate, etc., -O-P(-O-Si(CH ３ ) ３ ) ２ (for example, tristrimethylsilyl phosphite, etc.)

[0074] Furthermore, examples of the silylating agent in which X in the above general formula [1] is a monovalent organic group in which the element bonded to the Si element is oxygen include hexamethyldisiloxane, 1,3-diphenyl-1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane, 1,1,1-triethyl-3,3-dimethyldisiloxane, 1,1,3,3-tetra-n-octyldimethyldisiloxane, bis(nonafluorohexyl)tetramethyldisiloxane, 1,3-bis(trifluoropropyl)tetramethyldisiloxane, 1,3-di-n-butyltetramethyldisiloxane, Siloxane, 1,3-di-n-octyltetramethyldisiloxane, 1,3-diethyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, hexa-n-butyldisiloxane, hexaethyldisiloxane, hexavinyldisiloxane, 1,1,3,3-tetraisopropyldisiloxane, vinylpentamethyldisiloxane, 1,3-bis(3-chloroisobutyl)tetramethyldisiloxane, hexaphenyldisiloxane, 1,1,1-triethyl-3,3,3-trimethyldisiloxane, 1,3-bis(chloromethyl)tetramethyldisiloxane Methyldisiloxane, 1,1,3,3-tetraphenyldimethyldisiloxane, pentamethyldisiloxane, 1,3-bis(3-chloropropyl)tetramethyldisiloxane, 1,3-dichloro-1,3-diphenyl-1,3-dimethyldisiloxane, n-butyl-1,1,3,3-tetramethyldisiloxane, 1,3-di-t-butyldisiloxane, vinyl-1,1,3,3-tetramethyldisiloxane, 1,1,1-trimethyl-3,3,3-triphenyldisiloxane, 3,3-diphenyltetramethyltrisiloxane, 3-phenylheptamethoxane Chiltrisiloxane, hexamethylcyclotrisiloxane, n-propylheptamethyltrisiloxane, 3-ethylheptamethyltrisiloxane, 3-(3,3,3-trifluoropropyl)heptamethyltrisiloxane, 1,1,3,5,5-pentaphenyl-1,3,5-trimethyltrisiloxane, octamethyltrisiloxane, 1,1,5,5-tetraphenyl-1,3,3,5-tetramethyltrisiloxane, hexaphenylcyclotrisiloxane, 1,1,1,5,5,5-hexamethyltrisiloxane, 3-phenyl-1,1,3,5,5-pentamethyltrisiloxane, 1,3,5-trivinyl-1,1,3,5,5-pentamethyltrisiloxane, 1,3,5-trivinyl-1,3,5-trimethylcyclotrisiloxane, 3-octylheptamethyltrisiloxane, 1,3,5-triphenyltrimethylcyclotrisiloxane, 1,1,1,3,3,5,5-heptamethyltrisiloxane, 1,1,3,3,5,5-hexamethyltrisiloxane, 1,1,1,5,5,5-hexaethyl-3-methyltrisiloxane, furfuryloxytrisiloxane, tetrakis(dimethylsiloxy)silane, 1,1,3,3,5,5,7,7-octamethyltetrasiloxane, diphenylsiloxane-dimethylsiloxane copolymer, 1,3-diphenyl-1,3-dimethyldisiloxane Also included are siloxane compounds such as methylsiloxane, octamethylcyclotetrasiloxane, 1,3-bis(trimethylsiloxy)-1,3-dimethyldisiloxane, tetra-n-propyltetramethylcyclotetrasiloxane, octaethylcyclotetrasiloxane, decamethyltetrasiloxane, dodecamethylcyclohexasiloxane, dodecamethylpentasiloxane, tetradecamethylhexasiloxane, hexaphenylcyclotrisiloxane, polydimethylsiloxane, polyoctadecylmethylsiloxane, decamethylcyclopentasiloxane, poly(3,3,3-trifluoropropylmethylsiloxane), trimethylsiloxy-terminated polydimethylsiloxane, and 1,1,3,3,5,5,7,7,9,9-decamethylpentasiloxane.

[0075] Examples of the silylating agent in which X in the general formula [1] is a monovalent organic group in which the element bonded to the Si element is carbon include the amino group (—NH ２ group) to -C(S(=O) ２ R ７ ) ３ (where R ７ are each independently a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and fluorine atoms. Examples include those in which hydrogen atoms are replaced by (trimethylsilyl)tris(trifluoromethanesulfonyl)methide, etc.

[0076] Furthermore, examples of the silylating agent in which X in the general formula [1] is a monovalent organic group in which the element bonded to the Si element is halogen include the amino group (—NH ２ group) is replaced with a chloro group, a bromo group, or an iodo group (for example, chlorotrimethylsilane, bromotrimethylsilane, etc.).

[0077] The silylating agent may contain a cyclic silazane compound, such as cyclic disilazane compounds like 2,2,5,5-tetramethyl-2,5-disila-1-azacyclopentane and 2,2,6,6-tetramethyl-2,6-disila-1-azacyclohexane, cyclic trisilazane compounds like 2,2,4,4,6,6-hexamethylcyclotrisilazane and 2,4,6-trimethyl-2,4,6-trivinylcyclotrisilazane, and cyclic tetrasilazane compounds like 2,2,4,4,6,6,8,8-octamethylcyclotetrasilazane.

[0078] When the silylating agent is supplied in the form of a gas, it may be supplied as a mixed gas containing an inert gas. ２ , Ar, He, Ne, CF ４ etc. Preferably, N ２ , Ar, or He may also be used.

[0079] The silylation composition refers to a composition containing two or more of the above-mentioned silylating agents in combination, or a composition containing the above-mentioned mixed gas and a compound other than the silylating agent. The silylation composition may contain, in addition to the silylating agent, a catalytic compound that promotes the silylation reaction caused by the silylating agent. The catalytic compound is preferably one or more selected from the group consisting of Compound A (described below), acid imides, nitrogen-containing compounds, silicon-free nitrogen-containing heterocyclic compounds, and silylated heterocyclic compounds. The catalytic compound here refers to a compound that can promote the reaction between the above-mentioned surfaces and the silylating agent or enhance the water-repellent properties of the resulting water-repellent film, and may itself or a modified compound thereof may constitute part of the water-repellent film.

[0080] The concentration of the catalytic compound may be, for example, 0.005% by mass or more and 20% by mass or less, or 0.05% by mass or more and 15% by mass or less, relative to 100% by mass of the silylation composition.

[0081] Specific examples of the compound A include, for example, trimethylsilyl trifluoroacetate, trimethylsilyl trifluoromethanesulfonate, dimethylsilyl trifluoroacetate, dimethylsilyl trifluoromethanesulfonate, butyldimethylsilyl trifluoroacetate, butyldimethylsilyl trifluoromethanesulfonate, hexyldimethylsilyl trifluoroacetate, hexyldimethylsilyl trifluoromethanesulfonate, octyldimethylsilyl trifluoroacetate, octyldimethylsilyl trifluoromethanesulfonate, decyldimethylsilyl trifluoroacetate, and decyldimethylsilyl trifluoromethanesulfonate, and can contain one or more selected from them.These may be used alone or in combination of two or more.In addition, the compound A may also correspond to the above-mentioned silylating agent, but when used as a catalytic compound, it means that the compound A used and the above-mentioned silylating agent are used in combination.

[0082] The compound A may be obtained by reacting a silicon compound represented by the following general formula [2] with one or more acetic acids or sulfonic acids selected from the group consisting of trifluoroacetic acid, trifluoroacetic anhydride, trifluoromethanesulfonic acid, and trifluoromethanesulfonic anhydride. Any excess silicon compound represented by the following general formula [2] that remains unconsumed in the reaction can be used as the silylating agent together with the compound A obtained by the reaction. The silicon compound represented by the following general formula [2] may be reacted, for example, in a molar ratio of 0.2 to 100,000 times, preferably 0.5 to 50,000 times, more preferably 1 to 10,000 times, the acetic acid or sulfonic acid.

[0083] R ２ ｃ (H) ｄ Si-X [2]

[0084] In the above general formula [2], R ２ ｃ (H) ｄ As Si-, (CH ３ ) ３ Si-, (CH ３ ) ２ (H)Si-, (C ４ H ９ ) (CH ３ ) ２ Si-, (C ６ H １３ ) (CH ３ ) ２ Si-, (C ８ H １７ ) (CH ３ ) ２ Si-, (C １０ H ２１ ) (CH ３ ) ２ Si-, etc. X is the same as in the general formula [1] above.

[0085] The compound A may be at least one selected from the group consisting of sulfonic acids represented by the following general formula [3], anhydrides of the sulfonic acids, salts of the sulfonic acids, and sulfonic acid derivatives represented by the following general formula [4]: ８ -S(=O) ２ OH [3] [In the above general formula [3], R ８ is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms, some or all of whose hydrogen atoms may be replaced by fluorine atoms, and hydroxyl groups.] R ８’ -S(=O) ２ O—Si(H) ３－ｒ (R ９ ) ｒ [4] [In the above general formula [4], R ８’ is a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and R ９ are each independently at least one group selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and r is an integer of 1 to 3.

[0086] Furthermore, the compound A may be at least one selected from the group consisting of sulfonate esters represented by the following general formula [5], sulfonimides represented by the following general formulas [6] and [7], sulfonimide derivatives represented by the following general formulas [8] and [9], sulfonmethides represented by the following general formula

[10] , and sulfonmethide derivatives represented by the following general formula

[11] . １０ -S(=O) ２ OR １１ [5] [In the above general formula [5], R １０ is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms, some or all of whose hydrogen atoms may be replaced by fluorine atoms, and fluorine atoms; R １１ is a monovalent alkyl group having 1 to 18 carbon atoms. １２ -S(=O) ２ ) ２ NH [6] [In the above general formula [6], R １２ are each independently a group selected from the group consisting of a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and fluorine atoms. [In the above general formula [7], R １３ is a divalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms. １４ -S(=O) ２ ) ２ N) ｓ Si(H) ｔ (R １５ ) ４－ｓ－ｔ [8] [In the above general formula [8], R １４ are each independently a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms, some or all of whose hydrogen atoms may be replaced by fluorine atoms, and fluorine atoms; R １５ are each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, s is an integer of 1 to 3, t is an integer of 0 to 2, and the sum of s and t is 3 or less. [In the above general formula [9], R １６are each independently a divalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and R １７ are each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, u is an integer of 1 to 3, v is an integer of 0 to 2, and the sum of u and v is 3 or less.] (R １８ -S(=O) ２ ) ３ CH

[10] [In the above general formula

[10] , R １８ are each independently a group selected from the group consisting of a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and fluorine atoms. １９ -S(=O) ２ ) ３ C) ｗ Si(H) ｘ (R ２０ ) ４－ｗ－ｘ

[11] [In the above general formula

[11] , R １９ are each independently a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms, some or all of whose hydrogen atoms may be replaced by fluorine atoms, and fluorine atoms; R ２０ are each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, w is an integer of 1 to 3, x is an integer of 0 to 2, and the sum of w and x is 3 or less.

[0087] Furthermore, examples of the acid imides that can be used as catalytic compounds include compounds having a chemical structure in which an acid such as a carboxylic acid or phosphoric acid is imidized.

[0088] The nitrogen-containing compound that can be used as the catalytic compound includes at least one of the compounds represented by the following general formulas

[12] and

[13] : ２１ -N=C(NR ２２ ２ ) ２

[12] R ２１ -N=C(NR ２２２ ) R ２２

[13] [In the above general formulas

[12] and

[13] , R ２１ represents a hydrogen group, a —C≡N group, or —NO ２ R is selected from a hydrocarbon group in which some or all of the hydrogen atoms may be replaced by fluorine atoms, an alkylsilyl group, and the hydrocarbon group may contain oxygen atoms and / or nitrogen atoms, but when it contains a nitrogen atom, it is considered to have a non-cyclic structure. ２２ are each independently a hydrogen group, a —C≡N group, or —NO ２ and hydrocarbon groups in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and the hydrocarbon groups may contain oxygen atoms and / or nitrogen atoms, but when they contain nitrogen atoms, they are considered to have a non-cyclic structure.] Furthermore, examples of the nitrogen-containing compounds include compounds having a guanidine skeleton, such as guanidine, 1,1,3,3-tetramethylguanidine, 2-tert-butyl-1,1,3,3-tetramethylguanidine, 1,3-diphenylguanidine, 1,2,3-triphenylguanidine, N,N'-diphenylformamidine, and 2,2,3,3,3-pentafluoropropylamidine.

[0089] Furthermore, examples of the above-mentioned nitrogen-containing heterocyclic compounds not containing silicon atoms and silylated heterocyclic compounds that can be used as catalytic compounds include at least one of compounds represented by the following general formulas

[14] and

[15] : [In the above general formula

[14] , R ２３ and R ２４ are each independently a divalent organic group consisting of a carbon element and / or a nitrogen element and a hydrogen element, and the total number of carbon atoms and nitrogen atoms is 1 to 9, and when there are 2 or more carbon atoms, there may be carbon atoms that do not constitute the ring.] [In the above general formula

[15] , R ２５is an alkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by elemental fluorine, a trialkylsilyl group having an alkyl group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by elemental fluorine, an alkenyl group having 2 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by elemental fluorine, an alkoxy group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by elemental fluorine, an amino group, an alkylamino group having an alkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by elemental fluorine, a dialkylamino group having an alkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by elemental fluorine, an aminoalkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by elemental fluorine, a nitro group, a cyano group, a phenyl group, a benzyl group, or a halogen group; R ２６ , R ２７ and R ２８ are each independently an alkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, or a hydrogen group.

[0090] The silicon-free nitrogen-containing heterocyclic compound may contain heteroatoms other than nitrogen atoms, such as oxygen atoms and sulfur atoms, in the ring, may have aromaticity, and may be a compound in which two or more rings are bonded by a single bond or a polyvalent linking group having a valence of two or more. It may also have a substituent. Examples of the silicon-free nitrogen-containing heterocyclic compound include pyridine, pyridazine, pyrazine, pyrimidine, triazine, tetrazine, pyrrole, pyrazole, imidazole, triazole, tetrazole, oxazole, isoxazole, thiazole, isothiazole, oxadiazole, thiadiazole, quinoline, isoquinoline, cinnoline, phthalazine, quinoxaline, quinazoline, indole, indazole, benzimidazole, benzotriazole, benzoxazole, benzisoxazole, benzothiazole, benzisothiazole, benzoxadiazole, benzothiadiazole, saccharin, pyrrolidine, and piperidine.

[0091] In addition, the above-mentioned silylated heterocyclic compounds include silylated imidazole compounds and silylated triazole compounds. Examples of silylated heterocyclic compounds include monomethylsilylimidazole, dimethylsilylimidazole, trimethylsilylimidazole, monomethylsilyltriazole, dimethylsilyltriazole, trimethylsilyltriazole, etc. It should be noted that some of the above-mentioned silylated heterocyclic compounds correspond to the above-mentioned silylating agents, but when used as a catalytic compound, this means that they are used in combination with other silylating agents other than the silylated heterocyclic compounds.

[0092] In the silylation composition, the concentration of the silylating agent, or the total concentration of the silylating agent and the catalytic compound, relative to 100% by mass of the silylation composition, may be, for example, 0.01% by mass to 100% by mass, preferably 0.1% by mass to 50% by mass, and more preferably 0.5% by mass to 30% by mass.

[0093] Additionally, when the silylation composition is a liquid, the silylation composition may include a solvent.

[0094] The solvent is not particularly limited as long as it dissolves the silylating agent. Examples of solvents that can be used include organic solvents such as hydrocarbons, esters, ethers, ketones, halogen-containing solvents, sulfoxide-based solvents, alcohols, carbonate-based solvents, polyhydric alcohol derivatives, nitrogen-containing solvents, silicone solvents, and thiols. Among these, hydrocarbons, esters, ethers, halogen-containing solvents, sulfoxide-based solvents, and polyhydric alcohol derivatives that do not have an OH group are preferred. These solvents may be used alone or in combination of two or more.

[0095] Examples of the hydrocarbons include linear, branched, or cyclic hydrocarbon solvents, aromatic hydrocarbon solvents, and terpene solvents, such as n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane, n-tetradecane, n-hexadecane, n-octadecane, and n-eicosane, as well as branched hydrocarbons corresponding to the carbon numbers thereof (e.g., isododecane, isocetane, etc.), cyclohexane, methylcyclohexane, and the like. Examples of the solvent include cyclohexane, decalin, benzene, toluene, xylene, (ortho-, meta-, or para-)diethylbenzene, 1,3,5-trimethylbenzene, naphthalene, mesitylene, p-menthane, o-menthane, m-menthane, diphenylmenthane, limonene, α-terpinene, β-terpinene, γ-terpinene, bornane, norbornane, pinane, α-pinene, β-pinene, carane, longifolene, abietane, and terpene solvents.

[0096] Examples of the esters include methyl acetate, 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, methyl butyrate, 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, and ethyl ethoxyacetate.

[0097] Furthermore, the esters may be cyclic esters such as lactone compounds. Examples of lactone compounds 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.

[0098] Examples of the ethers 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 corresponding to the carbon numbers of these ethers, dimethyl ether, diethyl ether, methyl ethyl ether, methylcyclopentyl ether, diphenyl ether, tetrahydrofuran, and dioxane.

[0099] Examples of the ketones include acetone, acetylacetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, cyclohexanone, and isophorone.

[0100] Examples of the halogen element-containing solvent 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 Asahi Glass Co., Ltd.), Novec HFE-7100, and Novec Examples of such hydrocarbons 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.

[0101] Examples of the sulfoxide solvent include dimethyl sulfoxide.

[0102] Examples of the carbonate solvent include dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and propylene carbonate.

[0103] Examples of the alcohols include methanol, ethanol, 1-propanol, 2-propanol, 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, 2- Examples include methyl-2-pentanol, 3-methyl-2-pentanol, 4-methyl-2-pentanol, 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 4-methyl-2-pentanol.

[0104] Examples of the derivatives of the above polyhydric alcohols that do not have an OH group include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol diacetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, diethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol diacetate, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, triethylene glycol monomethyl ether acetate, and triethylene glycol monoethyl ether acetate. acetate, triethylene glycol monobutyl ether acetate, triethylene glycol diacetate, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dibutyl ether, tetraethylene glycol monomethyl ether acetate, tetraethylene glycol monoethyl ether acetate, tetraethylene glycol monobutyl ether acetate, tetraethylene glycol diacetate, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol diacetate, dipropylene glycol dimethyl ether, dipropylene glycol methylpropyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate,Dipropylene glycol monobutyl ether acetate, dipropylene glycol diacetate, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol dibutyl ether, tripropylene glycol monomethyl ether acetate, tripropylene glycol monoethyl ether acetate, tripropylene glycol monobutyl ether acetate, tripropylene glycol diacetate, tetrapropylene glycol dimethyl ether, tetrapropylene glycol monomethyl ether acetate, tetrapropylene glycol diacetate, butylene glycol dimethyl ether, butylene glycol monomethyl ether acetate, butylene glycol diacetate, glycerin triacetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, etc.

[0105] Examples of the nitrogen-containing solvent 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.

[0106] Examples of the silicone solvent include hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, and dodecamethylpentasiloxane.

[0107] Examples of the thiols include 1-hexanethiol, 2-methyl-1-pentanethiol, 3-methyl-1-pentanethiol, 4-methyl-1-pentanethiol, 2,2-dimethyl-1-butanethiol, 3,3-dimethyl-1-butanethiol, 2-ethyl-1-butanethiol, 1-heptanethiol, benzylthiol, 1-octanethiol, 2-ethyl-1-hexanethiol, 1-nonanethiol, 1-decanethiol, 1-undecanethiol, 1-dodecanethiol, and 1-tridecanethiol.

[0108] The solvent preferably contains an aprotic solvent. The content of the aprotic solvent is, for example, 80% by mass or more, preferably 90% by mass or more, relative to 100% by mass of the solvent. It is more preferable that the solvent is an aprotic solvent, i.e., the solvent contains the aprotic solvent at a content of 100% by mass relative to 100% by mass of the solvent.

[0109] Aprotic solvents include hydrocarbons, esters, ethers, ketones, halogen-containing solvents, sulfoxides, carbonate solvents, polyhydric alcohol derivatives, nitrogen-containing solvents, silicone solvents, etc. These may be used alone or in combination of two or more. Among these, it is preferable to use one or more selected from the group consisting of polyhydric alcohol derivatives, hydrocarbons, and ethers.

[0110] From the viewpoint of cost and solubility, derivatives of polyhydric alcohols (which do not have an OH group in the molecule) are preferred, such as diethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol diacetate, triethylene glycol dimethyl ether, ethylene glycol diacetate, ethylene glycol dimethyl ether, 3-methoxy-3-methyl-1-butyl acetate, Preferred are propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol diacetate, dipropylene glycol dimethyl ether, dipropylene glycol methyl propyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, and dipropylene glycol diacetate. Also preferred are propylene carbonate, linear or branched hydrocarbon solvents having 6 to 12 carbon atoms, p-menthane, diphenylmenthane, limonene, terpinene, bornane, norbornane, and pinane.

[0111] Examples of silylation compositions containing a silylating agent and a solvent include those in which the silylating agent is hexamethyldisilazane, heptamethyldisilazane, N-(trimethylsilyl)dimethylamine, bis(dimethylamino)dimethylsilane, bis(trimethylsilyl)trifluoroacetamide, N-methyl-N-trimethylsilyltrifluoroacetamide, N-trimethylsilylacetamide, N-trimethylsilylimidazole, trimethylsilyltriazole, bistrimethylsilyl sulfate, 2,2,5,5-tetramethyl-2,5-disila-1-azacyclopentane, 2,2,4,4,6,6-hexamethyldisilaz ... The catalyst may contain one or more selected from the group consisting of trimethylsilylcyclotrisilazane, hexamethyldisiloxane, trimethylsilyl trifluoroacetate, trimethylsilyl trifluoromethanesulfonate, trimethylsilylbenzenesulfonate, and trimethylsilyl toluenesulfonate, and the solvent may contain one or more selected from the group consisting of propylene carbonate, linear hydrocarbon solvents having 7 to 10 carbon atoms, menthane, pinane, γ-butyrolactone, propylene glycol monomethyl ether acetate, and 3-methoxy-3-methyl-1-butyl acetate.

[0112] The silylation composition may contain no water or may contain water in an amount of 2% by mass or less based on 100% by mass of the silylation composition, making it possible to use a silylation composition that is substantially free of water.

[0113] The silylation composition may contain other components in addition to those described above, provided that the purpose of the present invention is not impaired. Examples of such other components include oxidizing agents such as hydrogen peroxide and ozone, surfactants, and antioxidants such as BHT.

[0114] The silylation composition of this embodiment is obtained by mixing the above-mentioned components. The obtained mixture may be purified using an adsorbent, a filter, or the like, as necessary. Alternatively, each component may be purified in advance by distillation, or may be purified using an adsorbent, a filter, or the like.

[0115] 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.

[0116] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the descriptions of these examples.

[0117] <Production of Substrate> [Example 1] (1) Preparation Step The substrate used was a silicon substrate with a smooth surface measuring 30 mm x 40 mm x 1 mm. The following simulation test was carried out using substrate A having a first surface with a silicon single crystal plane orientation of (100) and substrate B having a second surface with a silicon single crystal plane orientation of (110). Note that the SiO composition ratio is not necessarily limited to Si:O = 1:1. Also, room temperature refers to 20 to 25°C.

[0118] (Natural Oxide Film Removal Treatment) Each of the prepared substrates was immersed in 0.02 mass % hydrofluoric acid (DHF) at room temperature for 1 minute, and then immersed in a rinse liquid (ultrapure water) for 1 minute.

[0119] (Oxidation Treatment) The substrate was irradiated with UV / O using a low-pressure mercury lamp at room temperature. ３ The substrate was placed in a UV / O device (manufactured by Novascan) and exposed to UV light for 30 minutes. ３ The irradiation power was 30 mW / cm at 254 nm. ２ Thereafter, the substrate was immersed in ultrapure water for 1 minute and in 2-propanol (IPA) for 2 minutes.

[0120] (Selective Removal Treatment) Each substrate was immersed in 0.1 mass % hydrofluoric acid (DHF), which was a solution containing water and hydrogen fluoride, for 7 minutes, and then immersed in ion-exchanged water for 1 minute and in IPA for 2 minutes.

[0121] (2) Silylation Step The substrate was immersed in a silylating agent prepared by the following method at room temperature for 3 minutes to silylate the surface of the substrate. The silylating agent was obtained by weighing and mixing 5 g of hexamethyldisilazane (HMDS), 3.5 g of trimethylsilyl trifluoroacetate, and 91.5 g of propylene glycol monomethyl ether acetate (PGMEA) at room temperature. The substrate was then immersed in IPA for 2 minutes. The substrate was then removed and dried by blowing air to remove the IPA.

[0122] (3) Etching step The substrate was immersed in a 0.1% by mass aqueous solution of ammonium hydroxide at a liquid temperature of 40° C. for 1 minute. Then, the substrate was immersed in ultrapure water for 1 minute and then in IPA for 2 minutes. After that, the substrate was taken out and dried by blowing air to remove the IPA.

[0123] <Etching Amount> The film thickness of each substrate was measured using an ellipsometer (SE-2000, manufactured by Nippon Semilab Co., Ltd.). Film thickness measurements were performed immediately before the (3) etching step and immediately after the (3) etching step. The difference in film thickness reduction from the initial film thickness was calculated as the etching amount (nm). The results are shown in Table 1. However, the initial film thickness includes the thickness of the oxide film on the surface formed in the preparation step. The "total amount" in Table 1 means that the entire oxide film (SiO film) formed on the substrate has disappeared.

[0124] <Water Contact Angle> The water contact angle was measured on the surface of each substrate by the following method, and the results are shown in Table 1. First, the substrate was placed horizontally with the treated surface of the measurement sample facing up, and a 2 μl droplet of pure water was placed on the surface. Next, in accordance with JIS R 3257:1999 "Test method for wettability of substrate glass surfaces," the angle between the water droplet and the substrate was measured using a contact angle meter (CA-X model, manufactured by Kyowa Interface Science Co., Ltd.), and the obtained value was taken as the water contact angle. In Table 1, the water contact angle on the first surface immediately after the step of preparing the substrate is shown as the CA-X. １Ｘ , the water contact angle on the second surface is CA ２Ｘ , the water contact angle on the first surface immediately after the silylation step is CA １Ｙ , the water contact angle on the second surface is CA ２ＹThe water contact angle was also measured immediately after the etching process, and the results are shown in Table 1.

[0125] Examples 2 to 7 The same procedures as in Example 1 were carried out except that the oxidation treatment, selective removal treatment, and / or etching process were changed to the conditions shown in Table 1.

[0126] Reference Examples 1 to 3 were the same as Examples 1, 2, and 4, respectively, except that the etching step was not performed. Reference Example 4 was the same as Example 4, except that the selective removal and etching steps were not performed.

[0127] Comparative Example 1: The same procedure as in Example 1 was carried out except that the silylation treatment was not carried out. Comparative Examples 2 and 3: The same procedure as in Example 4 was carried out except that the selective removal was not carried out.

[0128]

[0129] The results in Table 1 show that the semiconductor device manufacturing method of each Example is superior to Comparative Examples 1 to 3 in etching selectivity for the Si(100) surface relative to the Si(110) surface.

[0130] This application claims priority based on Japanese Patent Application No. 2024-112326, filed July 12, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0131] REFERENCE SIGNS LIST 1 substrate 11 first surface 12 second surface 21 silicon oxide-containing film 22 silicon oxide-containing film 30 silylation agent 32 water-repellent film

Claims

1. A method for manufacturing a semiconductor device, comprising: a preparation step of preparing a substrate having a structure including a first surface of silicon single crystal with a (100) orientation, a second surface with a (110) orientation, and a film containing silicon oxide formed on the second surface; a silylation step of supplying a silylation agent onto at least the second surface to form a water-repellent film selective to the film containing silicon oxide on the second surface; and an etching step of supplying an etching liquid onto at least the first surface to selectively etch the first surface relative to the second surface.

2. A method for manufacturing a semiconductor device according to claim 1, wherein the preparation step of preparing the base material includes an oxidation treatment for forming a film containing silicon oxide on at least the exposed second surface.

3. A method for manufacturing a semiconductor device according to claim 1, wherein the preparation step of preparing the base material includes: an oxidation treatment for forming a first film containing silicon oxide and a second film containing silicon oxide on the exposed first surface and the exposed second surface, respectively; and a selective removal treatment for removing the first film containing silicon oxide on the first surface and leaving the second film containing silicon oxide on the second surface.

4. A method for manufacturing a semiconductor device according to claim 2 or 3, wherein the oxidation treatment includes a treatment of contacting a gaseous oxidizing agent or a treatment of contacting a liquid oxidizing agent.

5. A method for manufacturing a semiconductor device according to claim 3, wherein the selective removal treatment uses a solution containing hydrogen fluoride.

6. A method for manufacturing a semiconductor device according to claim 5, wherein the concentration of hydrogen fluoride in the solution containing hydrogen fluoride is 0.01% by mass or more and 10% by mass or less.

7. A method for manufacturing a semiconductor device according to claim 5, wherein the solution containing hydrogen fluoride contains one or more selected from the group consisting of hydrofluoric acid, buffered hydrofluoric acid, hexafluorosilicic acid, and ammonium hexafluorosilicate.

8. A method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the etching solution contains a quaternary ammonium hydroxide.

9. A method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the silylation step includes supplying the silylating agent or supplying a silylation composition containing the silylating agent and a catalytic compound.

10. A method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the structure provided on the substrate has a plate-like structure.

11. The method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the water contact angle on the first surface immediately after the step of preparing the base material is measured by CA. １Ｘ , the water contact angle on the second surface is CA ２Ｘ , the water contact angle on the first surface immediately after the silylation step is CA １Ｙ , the water contact angle on the second surface is CA ２Ｙ When this is done, |CA １Ｙ -CA １Ｘ |<|CA ２Ｙ -CA ２Ｘ A method for manufacturing a semiconductor device that satisfies |.

12. The method for manufacturing a semiconductor device according to claim 11, comprising the steps of: |CA １Ｙ -CA １Ｘ | is 29° or less and |CA ２Ｙ -CA ２Ｘ | is 30° or more.

13. A method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein in the etching step, an etching selectivity ratio of the first surface to the second surface is 2 or greater.

14. A substrate having a structure including: a first surface of silicon single crystal with a (100) plane orientation; a second surface of silicon single crystal with a (110) plane orientation; a film containing silicon oxide formed on the second surface; and a water-repellent film formed on the film containing silicon oxide on the second surface.

15. A silylation composition used to form a water-repellent film on a silicon oxide-containing film formed on a second surface of a silicon single crystal having a (110) plane orientation, the silylation composition comprising a silylating agent.

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