Method for manufacturing substrate, and etching solution for germanium-containing oxide

Abstract

The method for manufacturing a substrate of the present invention includes: a preparation step of preparing a substrate having at least a first surface containing a silicon and a second surface containing a germanium-containing oxide; a silylation treatment step in which a silylating agent is brought into contact with at least the first surface; and an etching step in which the second surface is selectively etched with respect to the first surface by performing an etching treatment in which an etching solution containing hydrogen fluoride, water, and alcohol is brought into contact with the second surface.

Description

Method for manufacturing substrate and etching solution for Ge-containing oxide

[0001] The present invention relates to a method for producing a substrate and an etching solution for a Ge-containing oxide.

[0002] Various etching methods for silicon germanium have been developed to date. One such technique is known from Patent Document 1. Patent Document 1 describes a technique for selectively etching SiGe relative to hard mask layers, gate materials (e.g., SiN, polysilicon, or SiOx), and low-k dielectric layers (e.g., SiN, polysilicon, SiOx, carbon-doped oxide, or SiCO) present in semiconductor devices using an etching composition containing a fluorine-containing acid and an oxidizing agent (hydrogen peroxide in this example) (see, for example, claim 1 and paragraph 0006 of Patent Document 1).

[0003] Special Publication No. 2022-512116

[0004] The etching principle using the etching composition described in Patent Document 1 is presumed to involve simultaneous oxidation and etching of SiGe using an oxidizing agent and a fluorine-containing acid. It has also been found that such etching compositions are prone to undergo composition changes over time due to the reaction between the oxidizing agent and other components. In response to this, the present inventors have sought a method for selectively etching SiGe using a mechanism different from the above-mentioned etching principle.

[0005] As a result of extensive research, the present inventors have found that, while a first surface containing Si element is protected by silylation, a second surface containing Ge-containing oxide can be selectively etched by using an etching solution containing hydrogen fluoride, water, and alcohol, and have thus completed the present invention.

[0006] According to one aspect of the present invention, the following methods for manufacturing a substrate and an etching solution for a Ge-containing oxide are provided. 1. A method for manufacturing a substrate, comprising: a preparation step of preparing a substrate having at least a first surface containing Si element and a second surface containing Ge-containing oxide; a silylation treatment step of contacting at least the first surface with a silylating agent; and an etching step of contacting the second surface with an etching solution containing hydrogen fluoride, water, and an alcohol to selectively etch the second surface relative to the first surface. 2. A method for manufacturing a substrate according to 1., wherein the first surface does not contain Ge element, and the Ge-containing oxide is silicon germanium oxide. 3. A method for manufacturing a substrate according to 1. or 2., wherein the etching solution is substantially free of an oxidizing agent that forms a Ge-containing oxide. 4. A method for manufacturing a substrate according to any one of 1. to 3., wherein the alcohol in the etching solution includes a monohydric alcohol. 5. 4. 6. The method for manufacturing a substrate according to any one of 1. to 5., wherein the monohydric alcohol comprises one or more selected from the group consisting of 2-propanol, 1-propanol, ethanol, and methanol. 6. The method for manufacturing a substrate according to any one of 1. to 5., wherein the content of the alcohol is 30 mass% or more in 100 mass% of the etching solution. 7. The method for manufacturing a substrate according to any one of 1. to 6., wherein the content of the water is 70 mass% or less in 100 mass% of the etching solution. 8. The method for manufacturing a substrate according to any one of 1. to 7., wherein in the preparation step, the second surface is formed by an oxidation treatment. 9. The method for manufacturing a substrate according to 8., wherein the oxidation treatment includes a treatment of contacting a gaseous oxidizing agent or a treatment of contacting a liquid oxidizing agent. 10. 2. 2. The method for producing a substrate according to claim 1, wherein the content of Si element in the total of Si element and Ge element contained in the silicon germanium oxide in the preparing step is 95 mol % or less.11. The method for manufacturing a substrate according to any one of 1. to 10., wherein the silylation agent is used or a silylation composition containing the silylating agent and a catalytic compound is used in the silylation treatment step. 12. An etching solution for a Ge-containing oxide comprising hydrogen fluoride, water, and an alcohol. 13. The etching solution for a Ge-containing oxide according to 12., wherein the Ge-containing oxide is silicon germanium oxide. 14. The etching solution for a Ge-containing oxide according to 12. or 13., wherein the etching solution is substantially free of an oxidizing agent that forms a Ge-containing oxide.

[0007] According to the present invention, there are provided a method for producing a substrate having excellent etching selectivity for Ge-containing oxides, and an etching liquid for Ge-containing oxides.

[0008] Fig. 1 is a process cross-sectional view schematically showing an example of a preparation step in the method for producing a substrate of the present embodiment; Fig. 2 is a process cross-sectional view schematically showing an example of a silylation treatment step in the method for producing a substrate of the present embodiment; Fig. 3 is a process cross-sectional view schematically showing an example of a silylation treatment step in the method for producing a substrate of the present embodiment; Fig. 4 is a process cross-sectional view schematically showing an example of an etching step in the method for producing a substrate of the present embodiment.

[0009] 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.

[0010] An outline of the method for manufacturing the substrate of this embodiment will be described.

[0011] The method for manufacturing a substrate of this embodiment includes: a preparation step of preparing a substrate having at least a first surface containing Si element and a second surface containing a Ge-containing oxide; a silylation treatment step of contacting at least the first surface with a silylating agent; and an etching step of contacting the second surface with an etching solution containing hydrogen fluoride, water, and an alcohol, thereby selectively etching the second surface relative to the first surface.

[0012] In this specification, "selectively etching the second surface relative to the first surface" means that the ratio of the etching rates of the second surface to the first surface is 1.1 or more. The etching rate ratio is preferably 2 or more, more preferably 3 or more, and even more preferably 8 or more.

[0013] According to the findings of the present inventors, it has been found that the protective ability and / or water-repellent performance of a first surface containing Si elements can be enhanced by a silylation treatment compared to a second surface containing Ge elements. Although the detailed mechanism is unclear, the silylating agent converts Si—OH groups present on the first surface into silyl groups such as trimethylsilyl groups, thereby forming a protective layer (water-repellent layer) on the surface, but does not bond / adhere to Ge elements present on the second surface. As a result, Ge elements are exposed on the second surface, and the density of the protective layer on the second surface is relatively lower than that of the first surface. Therefore, it can be inferred that the silylation treatment enhances the density of the protective layer on the first surface containing Si elements compared to the protective layer on the second surface containing Ge elements.

[0014] Furthermore, according to the findings of the present inventors, an etching solution containing hydrogen fluoride and water is unable to etch germanium materials that do not contain O, but is capable of etching oxides of germanium materials. However, an etching solution containing hydrogen fluoride and water may also etch the first surface on which the protective film is formed. In contrast, it has been found that using an etching solution containing hydrogen fluoride and water to which alcohol has been added enables selective etching of the second surface while suppressing unintended etching of the first surface on which the protective film is formed. Although the detailed mechanism is unclear, it is inferred that an etching solution with mild etching ability can be realized because the alcohol suppresses the ionization of hydrogen fluoride and reduces the amount of fluorine ions, which are an etchant. Even if a protective film is formed on the second surface, the density of the protective film is reduced in the surface region where the Ge element is exposed, so the second surface can be etched even using an etching solution with mild etching ability.

[0015] As described above, in this embodiment, while the first surface containing Si element is protected by silylation, the second surface containing Ge-containing oxide can be selectively etched using an etching solution containing hydrogen fluoride, water, and alcohol.

[0016] 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 to each other. 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.

[0017] (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.

[0018] Furthermore, in this embodiment, a Ge-containing oxide etching solution containing hydrogen fluoride, water, and alcohol can be realized. Preferably, such an etching solution does not substantially contain an oxidizing agent that forms a Ge-containing oxide.

[0019] Each component of the method for producing a substrate according to this embodiment will be described in detail below.

[0020] An example of a method for manufacturing a substrate according to this embodiment includes a preparation step, a silylation treatment step, and an etching step, and will be described with reference to Figures 1 to 4. Figures 1 to 3 are cross-sectional views schematically illustrating the steps of the method for manufacturing a substrate.

[0021] (Preparation Step) In the preparation step, as shown in FIG. 1, a substrate 1 having a first surface 11 and a second surface 12 on its surfaces is prepared.

[0022] 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.

[0023] 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 1a 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.

[0024] The first surface 11 and the second surface 12 may be arranged along the planar direction of the substrate surface 1a, or along a direction perpendicular to the substrate surface 1a. According to this embodiment, not only two-dimensional selective processing of a plane but also three-dimensional selective processing of a three-dimensional structure (such as three-dimensional film formation or three-dimensional etching) is possible. Here, the first surface 11 and the second surface 12 refer to the outermost surfaces of the first and second layers of the substrate 1, respectively. The first and second surfaces 11 and 12 may or may not have the same composition as the first and second layers. "Not having the same composition" means, for example, that (i) the first surface 11 or the second surface 12 contains an O element while the first or second layer does not contain an O element, and / or (ii) the composition ratio is different, such as the O element content of the first surface 11 or the second surface 12 being higher than the O element content of the first or second layer.

[0025] 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 regions. In each surface, the multiple regions may be formed spaced apart from each other.

[0026] The first surface 11 is a surface containing Si elements, has Si-OH groups on the surface, and is a surface whose water repellency is selectively improved by a silylation agent. The first layer having the first surface 11 is a layer containing a silicon material containing Si elements. The content of the silicon material in the first layer is preferably 80 mol % or more, more preferably 99 mol % or more, relative to the elements constituting the first layer, and may be substantially made of silicon material only. Examples of silicon materials include silicon oxide, silicon nitride, silicon carbide, silicon oxynitride, silicon oxycarbide, silicon carbide nitride, silicon oxynitride carbide, single crystal silicon, polysilicon, and low-k materials. Alternatively, the silicon may be a compound of Si and at least one element selected from the group consisting of N, C, and O. The low-k material is a material having a dielectric constant lower than that of silicon oxide (e.g., SiO ２ ) and examples thereof include SiON, SiCN, SiCO, SiCOH, and SiOCN. Note that the compositions of low-k materials are merely representative, and the stoichiometric ratio does not have to be the integer ratio as shown. Specifically, in the case of SiON, the ratio is not limited to Si:O:N=1:1:1.

[0027] The first surface 11 preferably contains one or more elements (including at least Si) selected from the group consisting of Si, N, C, and O. Within the above range, the silylating agent is more likely to form bonds, further improving water repellency. Furthermore, it is preferable for the surface to contain many regions having Si-OH bonds, and a surface on which Si-OH bonds have been formed by surface treatment may be used. More preferably, the first surface 11 may contain Si and O, and the total content of Si and O relative to the elements constituting the first surface 11 may be 80 mol % or more. Furthermore, the first surface 11 may contain elements other than Si, N, C, and O (e.g., H, P, B) as long as the water repellency imparted by contact with a chemical solution is not significantly impaired. It is preferable that the first surface 11 does not contain Ge elements, and even if Ge elements are mixed in, the content of Ge elements in the total of Si elements and Ge elements is preferably 1 mol% or less, more preferably 0.1 mol% or less, and particularly preferably 0.01 mol% or less, and the content may be about the same as that of unavoidable impurities.

[0028] The second surface 12 is a surface containing a Ge-containing oxide, and is less likely to be imparted with water repellency by a silylating agent than the first surface 11, or is a surface to which water repellency by a silylating agent is not imparted. The Ge-containing oxide may be any oxide containing Ge and O, and is preferably a silicon germanium oxide. The Ge content of the second surface 12 is preferably 5 mol% or more higher, more preferably 10 mol% or more higher, and particularly preferably 20 mol% or more higher than the Ge content of the first surface 11. The second surface 12 preferably has a total content of Si, Ge, and O relative to the elements constituting the second surface 12 of 80 mol% or more, more preferably 99 mol% or more, and may be substantially composed of only Si, Ge, and O. The Ge content of the Ge oxide is, for example, 5 to 100 mol%, preferably 10 to 50 mol%, and more preferably 20 to 40 mol% relative to the total of Si and Ge, which is 100 mol%. The content of elemental Si contained in the Ge-containing oxide is, for example, 0 to 95 mol %, preferably 50 to 90 mol %, and more preferably 60 to 80 mol %, based on 100 mol % of the total of elemental Si and elemental Ge. The content of elemental O contained in the Ge-containing oxide is, for example, 5 to 80 mol %, preferably 10 to 75 mol %, and more preferably 20 to 70 mol %, based on 100 mol % of the total of elemental Ge. Even if a region having Si—OH bonds is present on the second surface 12, the presence of elemental Ge prevents the formation of a dense silylated protective layer, making it difficult or impossible to impart water repellency. The second surface 12 may contain other elements (e.g., O, N, C, H, P, B) within a range that does not adversely affect film formation in the etching step. In this specification, the symbol "to" indicates that the range includes both the upper and lower limits, unless otherwise specified.

[0029] 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.

[0030] The substrate 1 may further have a third surface and / or a fourth surface (not shown) on the substrate surface 1a. 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.

[0031] The preparation step may also include a step of obtaining the first surface 11 and / or the second surface 12 by performing an oxidation treatment on the first surface 11' not containing O element and / or the second surface 12' not containing O element. In a preferred embodiment, the oxidation treatment is performed on at least the second surface 12', and may be performed on both the first surface 11' and the second surface 12'. Examples of materials contained in the first surface 11' include single crystal silicon, polysilicon, silicon nitride, silicon carbide, silicon carbide nitride, etc. Examples of materials contained in the second surface 12' include Ge-containing materials such as germanium and silicon germanium. The ratio of Si element to Ge element in the Ge-containing material is the same as that in the Ge-containing oxide.

[0032] The oxidation treatment may be any treatment that oxidizes the Ge-containing material, and is preferably one that does not etch the silicon material. Specific examples of the oxidation treatment include a treatment involving contact with a gaseous oxidizing agent or a treatment involving contact with a liquid oxidizing agent. Examples of treatment involving contact with a gaseous oxidizing agent include treatment A-2a below, and examples of treatment involving contact with a liquid oxidizing agent include treatment A-2b. The oxidation treatment may result in the formation of a new OH group-containing region on the first surface 11, or in the formation of a film having OH groups (Si—OH film). The OH groups on the first surface 11 serve as reaction sites with the silylation agent in the subsequent silylation treatment. The oxidation treatment time may be 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.

[0033] Treatment A-2a is a treatment that oxidizes the Si-based surface more easily than treatment A-2b. Treatment A-2a involves contacting the first surface 11' and / or the second surface 12' with an active species containing oxygen or an oxidizing agent in the form of a gas containing oxygen. Specific methods for treatment A-2a include well-known oxidation treatments used in dry processes, such as plasma treatment using plasma containing oxygen, UV / O ３ and gas treatment in which the surface is exposed to a gas containing oxygen. The treatment A-2a is likely to oxidize the Si-based surface, so that even if a native oxide film is formed on the surface, it is possible to form OH groups on the first surface 11. The above-mentioned plasma treatment may be a known method, for example, O ３ Plasma treatment, O ２ Plasma treatment, CO ２ Plasma treatment, CO plasma treatment, NO ２ Plasma treatment, NO plasma treatment, H ２ O plasma treatment. ３The 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] Treatment A-2b is a treatment that can oxidize the Si-based surface more gently than treatment A-2a. Treatment A-2b involves bringing an oxidizing agent containing oxygen element into contact with the first surface 11' and / or the second surface 12'. As the oxidizing agent, a gas containing oxygen element that does not have as much oxidizing power as treatment A-2a may be used, or the same gas may be used under weak oxidation conditions, but it is preferable to use a liquid oxidizing agent because it is easy to adjust the strength of oxidation. As the liquid oxidizing agent, for example, 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 ２Examples of the contacting method include a known method, such as the same method as the silylation treatment described below. Examples of ozone water include an aqueous solution with 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. H ２ O ２ Examples of the aqueous solution include an aqueous solution containing hydrogen peroxide at a concentration of 0.05 to 40% by mass. ２ O ２ The temperature at which the aqueous solution is brought into contact may be, for example, 10 to 50°C. ２ O ２ Examples of the solution containing ２ O ２ and ammonium hydroxide alkaline mixture (SC-1 liquid) and H ２ O ２ Alternatively, an acidic mixture of ammonium hydroxide and hydrochloric acid (SC-2 solution) may be used. 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 a cleaning process. Specific methods for treatment A-1 include, for example, a method of contacting hydrofluoric acid (HF) with the first surface 11' and / or the second surface 12', and a method of contacting a diluted hydrofluoric acid aqueous solution (DHF) with the first surface 11' and / or the second surface 12'. The specific contacting method may be a known method, such as a method similar to 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 ２Treatment with a solution containing or ozone water is preferred.

[0037] (Silylation Treatment Step) In the silylation treatment step, a silylation treatment is carried out after the preparation step, as shown in Figures 2 and 3. In addition, as an example, the silylation treatment step may be carried out after the oxidation treatment. As a result, a protective film (water-repellent film 21) is formed at least on the first surface 11.

[0038] 2, the silylation treatment involves contacting at least the first surface 11 and the second surface 12 with a silylating agent 20, which will be described later. In the silylation treatment, the silylating agent 20 may be used alone, or a silylation composition 20 containing a silylating agent, a solvent, and a diluent gas, or a silylation composition 20 containing a silylating agent, a catalytic compound, and, if necessary, a solvent and a rare gas, may be used. The silylating agent 20 and the silylation composition 20 may be used in the form of a liquid or a gas.

[0039] In the case of a wet process, a liquid of the silylation agent 20 or silylation composition 20 is supplied to the first surface 11 and the second surface 12. Known methods can be used for supplying the silylation agent 20 or silylation composition 20. For example, when the agent is supplied in a liquid state, a single-wafer method such as a spin coating method or a batch method such as a dipping method can be used. When the agent is supplied as a vapor and becomes a liquid after contacting the first surface 11 and the second surface 12, a known vapor injection method can be used.

[0040] In the case of a dry process, the silylation agent is supplied as a gas to the first surface 11 and the second surface 12. A known method can be used for the supply method, but for example, a method in which the silylation agent is gasified in advance using a vaporizer or the like and then supplied; ２ In addition, two or more kinds of gases may be supplied simultaneously or may be mixed in advance and supplied.

[0041] The silylation treatment can improve the water repellency of at least the first surface 11. At this time, the water repellency of the second surface 12 may also be increased. The silylation treatment improves the water repellency of the first surface 11 by forming a structure in which silyl groups derived from the silylating agent are chemically bonded to OH groups on the first surface 11, i.e., a water-repellent film. A water-repellent film may also be formed on the second surface 12. Even if a water-repellent film is not formed, the water repellency may be increased by forming a structure in which a compound derived from the silylating agent is physically bonded (e.g., attached or adsorbed) to the surface.

[0042] 3, a water-repellent film 21 (protective film) may be formed on the first surface 11. The water-repellent film 21 may be configured as a film that covers at least a part of or the entire surface. A water-repellent film (not shown) may also be formed on the second surface 12, but it is not necessarily required that a water-repellent film be formed.

[0043] The silylation treatment step may optionally include a cleaning treatment in which at least a portion of the second surface 12 is cleaned using a cleaning agent. When at least a portion of each treatment is performed by a wet process, one or more cleaning treatments may be performed between each treatment. When multiple cleaning treatments are performed, the type of cleaning agent may be changed for each treatment.

[0044] The cleaning material may include an aqueous cleaning solution and / or a rinse solution.

[0045] The aqueous cleaning solution is not particularly limited as long as it does not remove the water-repellent film 21 formed on the first surface 11. Examples include water, alcohol, an aqueous hydrogen peroxide solution, and ozone water. These may be used alone or in combination of two or more.

[0046] Like the aqueous cleaning solution, the rinse solution is not particularly limited as long as it does not remove the water-repellent film 21 formed on the first surface 11. A cleaning agent different from that used in the aqueous cleaning solution can be used as the rinse solution, and examples thereof include 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).

[0047] 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.

[0048] The silylation step may be subjected to a drying treatment as needed. 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.

[0049] (Etching Step) In the etching step, the second surface 12 is selectively etched after the silylation step, as shown in FIG. 4 . While etching of the first surface 11 is suppressed, etching of the second surface 12 proceeds more rapidly than that of the first surface 11. This allows selective etching of the second surface 12 compared to the first surface 11. After the etching step, the entire second surface 12 may be removed, or a portion of the second surface 12 may remain. If a portion of the second surface 12 remains, a cycle including the silylation step and the etching step, or a cycle including the oxidation step, the silylation step, and the etching step, may be repeated once or twice or more times. Between cycles, one or more known processes, such as the above-mentioned cleaning process, may be performed. The etching step may last for 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.

[0050] Although the detailed mechanism is unclear, it is presumed that the remaining water-repellent film 21 acts as a shield against the etching solution, so that etching of the first surface 11 is suppressed more than etching of the second surface 12.

[0051] The etching solution is a composition containing hydrogen fluoride, water, and alcohol. The lower limit of the hydrogen fluoride content in the etching solution is, for example, 0.1 mass% or more, preferably 0.2 mass% or more, and more preferably 0.5 mass% or more, based on 100 mass% of the etching solution. On the other hand, the upper limit of the hydrogen fluoride content in 100 mass% of the etching solution is, for example, 10 mass% or less, preferably 5 mass% or less, and more preferably 2 mass% or less.

[0052] It is preferable that the etching solution is substantially free of an oxidizing agent that oxidizes silicon germanium. This can prevent the composition of the etching solution from fluctuating over time. "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.

[0053] The etching solution may also be substantially free of a silane coupling agent. "Substantially free of a silane coupling agent" means that the etching solution does not contain a silane coupling agent or the content of the silane coupling agent in the etching solution is 0.1 mass % or less. The silane coupling agent is a silane compound represented by the following formula: Si-R ３１ R ３２ R ３３ R ３４ In the above formula, R ３１ , R ３２ , R ３３ , and R ３４ each independently represents N(RR'), RC(O)O, C1-C8 alkoxy (e.g., methoxy or ethoxy), N(RR'), or Si(R ａ R ｂ Rｃ Each of R and R' is independently a C1-C10 alkyl, and R ａ , R ｂ , and R ｃ is independently a C1 to C10 alkyl or a C1 to C10 alkoxy. Examples of the silane coupling agent include 3-aminopropyltriethoxysilane, methyltrimethoxysilane, dimethylaminotrimethylsilane, acetoxytrimethylsilane, octyltrimethoxysilane, butyltrimethoxysilane, dodecyltrimethoxysilane, hexyltrimethoxysilane, octadecyltrimethoxysilane, or bis(trimethoxysilyl)methane.

[0054] The alcohol contained in the etching solution may contain, for example, a polyhydric alcohol such as a monohydric alcohol or a dihydric alcohol, but preferably contains a monohydric alcohol. By containing a monohydric alcohol, it is possible to control the viscosity of the etching solution to be lower than in the case of a polyhydric alcohol. In other words, it can be suitably used for substrates having a fine uneven structure.

[0055] Examples of monohydric alcohols include 2-propanol, 1-propanol, ethanol, and methanol. These may be contained alone or in any combination of two or more.

[0056] The lower limit of the alcohol content in 100 mass% of the etching solution is, for example, 30 mass% or more, preferably 50 mass% or more, and more preferably 70 mass% or more, while the upper limit of the alcohol content in 100 mass% of the etching solution is, for example, 99.8 mass% or less, preferably 99.6 mass% or less, and more preferably 99.0 mass% or less.

[0057] The lower limit of the water content in the etching solution may be, for example, 0.1 mass % or more, 0.2 mass % or more, 0.5 mass % or more, 1 mass % or more, 5 mass % or more, or 10 mass % or more, relative to 100 mass % of the etching solution. On the other hand, the upper limit of the water content in 100 mass % of the etching solution is, for example, 70 mass % or less, preferably 50 mass % or less, and more preferably 30 mass % or less.

[0058] If the water-repellent film 21 remaining on the first surface 11 after the etching step is unnecessary, the water-repellent film 21 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, for example, by contacting with an ammonium hydroxide aqueous solution, a tetramethylammonium aqueous solution, a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution, or the like.

[0059] The method for manufacturing a substrate of this embodiment includes a step of obtaining a substrate that has been subjected to each of the steps in the method for manufacturing a substrate described above. By the method for manufacturing a substrate, a desired semiconductor wafer or semiconductor device can be obtained.

[0060] <Silylating Agent> The silylating agent used in the silylation treatment in the above-described method for producing a substrate and the silylation composition containing the silylating agent will now be described.

[0061] 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.

[0062] R １ ａ Si(H) ｂ X ４－ａ－ｂ [1]

[0063] 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.

[0064] 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.

[0065] 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, 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.

[0066] 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 atom is nitrogen include CH ３ Si(NH ２ ) ３ , C ２ H ５ Si(NH ２ ) ３ , C ３ H ７ Si(NH ２ ) ３、C ４ H ９ H ２ ) ３ 、C ５ H １１ H ２ ) ３ 、C ６ H １３ H ２ ) ３ 、C ７ H １５ H ２ ) ３ 、C ８ H １７ H ２ ) ３ 、C ９ H １９ H ２ ) ３ 、C １０ H ２１ H ２ ) ３ 、C １１ H ２３ H ２ ) ３ 、C １２ H ２５ H ２ ) ３ 、C １３ H ２７ H ２ ) ３ 、C １４ H ２９ H ２ ) ３ 、C １５ H ３１ H ２ ) ３ 、C １６ H ３３ H ２ ) ３ 、C １７ H ３５ H ２ ) ３ 、C １８ H ３７ H ２ ) ３ 、(CH ３ ) ２ H ２ ) ２ 、C ２ H５ H ３ ) ２ ) ２ 、(C ２ H ５ ) ２ H ２ ) ２ 、C ３ H ７ H ３ ) ２ ) ２ 、(C ３ H ７ ) ２ H ２ ) ２ 、C ４ H ９ H ３ ) ２ ) ２ 、(C ４ H ９ ) ２ H ２ ) ２ 、C ５ H １１ H ３ ) ２ ) ２ 、C ６ H １３ H ３ ) ２ ) ２ 、C ７ H １５ H ３ ) ２ ) ２ 、C ８ H １７ H ３ ) ２ ) ２ 、C ９ H １９ H ３ ) ２ ) ２ 、C １０ H ２１ H ３ ) ２ ) ２ 、C １１ H ２３ H ３ ) ２ ) ２ 、C１２ H ２５ H ３ ) ２ ) ２ 、C １３ H ２７ H ３ ) ２ ) ２ 、C １４ H ２９ H ３ ) ２ ) ２ 、C １５ H ３１ H ３ ) ２ ) ２ 、C １６ H ３３ H ３ ) ２ ) ２ 、C １７ H ３５ H ３ ) ２ ) ２ 、C １８ H ３７ H ３ ) ２ ) ２ 、(CH ３ ) ３ H ２ 、C ２ H ５ H ３ ) ２ NH ２ 、(C ２ H ５ ) ２ H ３ )NH ２ 、(C ２ H ５ ) ３ H ２ 、C ３ H ７ H ３ ) ２ NH ２ 、(C ３ H ７ ) ２ H ３ )NH ２ 、(C ３ H ７ ) ３H ２ 、C ４ H ９ H ３ ) ２ NH ２ 、(C ４ H ９ ) ３ H ２ 、C ５ H １１ H ３ ) ２ NH ２ 、C ６ H １３ H ３ ) ２ NH ２ 、C ７ H １５ H ３ ) ２ NH ２ 、C ８ H １７ H ３ ) ２ NH ２ 、C ９ H １９ H ３ ) ２ NH ２ 、C １０ H ２１ H ３ ) ２ NH ２ 、C １１ H ２３ H ３ ) ２ NH ２ 、C １２ H ２５ H ３ ) ２ NH ２ 、C １３ H ２７ H ３ ) ２ NH ２ 、C １４ H ２９ H ３ ) ２ NH ２ 、C １５ H ３１ H ３ ) ２ NH ２ 、C１６ H ３３ H ３ ) ２ NH ２ 、C １７ H ３５ H ３ ) ２ NH ２ 、C １８ H ３７ H ３ ) ２ NH ２ 、(CH ３ ) ２ H. ２ CH ３ H ２ NH ２ 、(C ２ H ５ ) ２ H. ２ 、C ２ H ５ H ２ NH ２ 、C ２ H ５ H ３ )(H)NH ２ 、(C ３ H ７ ) ２ H. ２ 、C ３ H ７ H ２ NH ２ CF ３ CH ２ CH ２ H ２ ) ３ 、C ２ F ５ CH ２ CH ２ H ２ ) ３ 、C ３ F ７ CH ２ CH ２ H ２ ) ３ 、C ４ F ９ CH ２ CH ２ H ２ ) ３ 、C５ F １１ CH ２ CH ２ H ２ ) ３ 、C ６ F １３ CH ２ CH ２ H ２ ) ３ 、C ７ F １５ CH ２ CH ２ H ２ ) ３ 、C ８ F １７ CH ２ CH ２ H ２ ) ３ CF ３ CH ２ CH ２ H ３ ) ２ ) ２ 、C ２ F ５ CH ２ CH ２ H ３ ) ２ ) ２ 、C ３ F ７ CH ２ CH ２ H ３ ) ２ ) ２ 、C ４ F ９ CH ２ CH ２ H ３ ) ２ ) ２ 、C ５ F １１ CH ２ CH ２ H ３ ) ２ ) ２ 、C ６ F １３ CH ２ CH ２ H ３ ) ２ ) ２ 、C７ F １５ CH ２ CH ２ H ３ ) ２ ) ２ 、C ８ F １７ CH ２ CH ２ H ３ ) ２ ) ２ CF ３ CH ２ CH ２ H ３ ) ２ NH ２ 、C ２ F ５ CH ２ CH ２ H ３ ) ２ NH ２ 、C ３ F ７ CH ２ CH ２ H ３ ) ２ NH ２ 、C ４ F ９ CH ２ CH ２ H ３ ) ２ NH ２ 、C ５ F １１ CH ２ CH ２ H ３ ) ２ NH ２ 、C ６ F １３ CH ２ CH ２ H ３ ) ２ NH ２ 、C ７ F １５ CH ２ CH ２ H 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.

[0067] 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; 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 ２ H ５ Si(H) ２ OCH ３ , C ２ H ５ Si(CH ３ )(H)OCH ３ , (C ３ H ７ ) ２ Si(H)OCH<000​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​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.)

[0068] 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.

[0069] 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.

[0070] 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.).

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] R ２ ｃ (H) ｄ Si-X [2]

[0078] 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.

[0079] 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.

[0080] 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 in which some or all of the 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 in which some or all of the 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.

[0081] 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.

[0082] 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.

[0083] Furthermore, examples of the above-mentioned silicon-atom-free nitrogen-containing heterocyclic compounds 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] Additionally, when the silylation composition is a liquid, the silylation composition may include a solvent.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] Examples of the ketones include acetone, acetylacetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, cyclohexanone, and isophorone.

[0094] 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 AGC), 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.

[0095] Examples of the sulfoxide solvent include dimethyl sulfoxide.

[0096] Examples of the carbonate solvent include dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and propylene carbonate.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] Examples of the silicone solvent include hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, and dodecamethylpentasiloxane.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] <Production of Substrate> [Example 1] (1) Preparation Step (Deposition of Film) A silicon substrate having a smooth surface and a size of 30 mm × 40 mm × 1 mm was used as the substrate. ２ , hereinafter SiO), silicon germanium (Si ０．７５ Ge ０．２５ (hereinafter referred to as SiGe), silicon oxynitride carbide (hereinafter referred to as SiOCN), and polysilicon (hereinafter referred to as Si) were each deposited to a thickness of 10 nm. However, when depositing the Si film, a SiO film was first deposited and then a Si film was deposited thereon for later film thickness measurement. The following simulation tests were performed using substrate A on which a SiO film was deposited as the first surface, substrate B on which a SiGe film was deposited as the second surface, and, as necessary, substrate C on which a SiOCN film was deposited as the first surface and substrate D on which Si was deposited as the first surface. Note that the composition ratio of SiOCN is not necessarily limited to Si:O:C:N = 1:1:1:1. Also, room temperature refers to 20 to 25°C.

[0112] (Natural Oxide Film Removal Treatment) Each of the prepared substrates was immersed in 0.02 wt % hydrofluoric acid (DHF) at room temperature for 1 minute, and then immersed in a rinse solution (ultrapure water) for 1 minute.

[0113] (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 / O for 30 minutes. ３ The irradiation power was 30 mW / cm at 254 nm. ２The substrate B was then immersed in ultrapure water for 1 minute and in 2-propanol (IPA) for 2 minutes. At this time, it was confirmed that element O was present on the second surface of the substrate B. In other Examples 2 to 9 and Comparative Examples 1 and 4 described below, it was also confirmed that element O was present on the second surface of the substrate B. In other words, the outermost surface of the silicon germanium layer of the substrate B was oxidized to form a silicon germanium oxide layer.

[0114] (2) Silylation Treatment 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 trimethylsilyltrifluoroacetate, 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.

[0115] (3) Etching step: The substrate was immersed for 5 minutes at room temperature in an etching solution containing 0.7% by mass of hydrogen fluoride, 86.3% by mass of IPA (alcohol in Table 1), and 13% by mass of water. The substrate was then immersed for 1 minute in ultrapure water and then for 2 minutes in IPA. The substrate was then removed and dried by blowing air onto it to remove the IPA.

[0116] <Etching Amount> The thickness of the film formed on each substrate was measured using an ellipsometer (SE-2000, manufactured by Nippon Semilab Co., Ltd.). The 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.

[0117] [Examples 2, 5 to 7] The same as Example 1 except that the oxidation treatment and etching process were changed to the conditions in Table 1. [Examples 3 and 4] The same as Example 1 except that the oxidation treatment and etching process were changed to the conditions in Table 1 and that ethanol was used instead of IPA as the alcohol in Table 1 used in the etching solution. [Example 8] The same as Example 1 except that the oxidation treatment and etching process were changed to the conditions in Table 1. However, the ozone water was O ３ The concentration was 10 ppm, and the oxidation treatment was carried out at room temperature.

[0118] [Comparative Example 1] The same as Example 1 was performed except that an etching solution containing no alcohol was used. [Comparative Examples 2 and 3] The same as Example 1 was performed except that the oxidation treatment was not performed. [Comparative Example 4] The same as Example 1 was performed except that the silylation treatment step was not performed.

[0119]

[0120] The results in Table 1 show that the manufacturing methods of the substrates of the Examples are superior to Comparative Examples 1 to 4 in etching selectivity for Ge-containing oxides.

[0121] In Examples 1, 2, and 8, silicon germanium was selectively etched relative to silicon oxide, silicon oxynitride carbide, and polysilicon. Since the etching amount of the SiGe layer did not differ significantly between Examples 1 and 2, it appears that the silicon germanium oxide thickness produced by the oxidation treatment in Examples 1 and 2 was approximately 2 nm, and was almost completely etched within a 5-minute treatment time, with no etching of the underlying silicon germanium. Comparing Examples 4 and 6, the etching rate of silicon germanium oxide slowed as the amount of water in the etching solution composition decreased. In Comparative Example 1, since the etching solution did not contain alcohol, etching of the silicon oxide proceeded rapidly, and the entire silicon oxide layer was etched. In Comparative Examples 2 and 3, since no oxidation treatment was performed and no silicon germanium oxide layer was formed, etching of the silicon germanium layer did not proceed. In Comparative Example 4, since the silylation treatment step was not performed, etching of the silicon oxide proceeded rapidly, and the entire silicon oxide layer was etched.

[0122] This application claims priority based on Japanese Patent Application No. 2024-026445, filed February 26, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0123] REFERENCE SIGNS LIST 1 substrate 1a substrate surface 11 first surface 12 second surface 20 silylation agent, silylation composition 21 water-repellent film

Claims

1. A method for manufacturing a substrate, comprising: a preparation step of preparing a substrate having at least a first surface containing Si element and a second surface containing a Ge-containing oxide; a silylation treatment step of contacting at least the first surface with a silylating agent; and an etching step of contacting the second surface with an etching solution containing hydrogen fluoride, water, and an alcohol, thereby selectively etching the second surface relative to the first surface.

2. A method for manufacturing a substrate according to claim 1, wherein the first surface does not contain Ge element, and the Ge-containing oxide is silicon germanium oxide.

3. A method for producing a substrate according to claim 1 or 2, wherein the etching solution does not substantially contain an oxidizing agent that forms a Ge-containing oxide.

4. The method for producing a substrate according to claim 1 or 2, wherein the alcohol in the etching solution contains a monohydric alcohol.

5. The method for producing a substrate according to claim 4, wherein the monohydric alcohol comprises one or more selected from the group consisting of 2-propanol, 1-propanol, ethanol, and methanol.

6. The method for manufacturing a substrate according to claim 1 or 2, wherein the content of the alcohol is 30 mass % or more in 100 mass % of the etching solution.

7. The method for producing a substrate according to claim 1 or 2, wherein the content of water is 70 mass % or less in 100 mass % of the etching solution.

8. A method for manufacturing a substrate according to claim 1 or 2, wherein in the preparation step, the second surface is formed by an oxidation treatment.

9. The method for manufacturing a substrate according to claim 8, wherein the oxidation treatment includes a treatment of contacting a gaseous oxidizing agent or a treatment of contacting a liquid oxidizing agent.

10. A method for manufacturing a substrate according to claim 2, wherein the content of Si element in the total of Si element and Ge element contained in the silicon germanium oxide in the preparation step is 95 mol % or less.

11. A method for producing a substrate according to claim 1 or 2, wherein the silylation treatment step uses the silylating agent or a silylation composition containing the silylating agent and a catalytic compound.

12. An etching solution for Ge-containing oxides, comprising hydrogen fluoride, water, and alcohol.

13. The etching solution for Ge-containing oxides according to claim 12, wherein the Ge-containing oxide is silicon germanium oxide.

14. The etching solution for Ge-containing oxides according to claim 12 or 13, which is substantially free of an oxidizing agent that forms Ge-containing oxides.

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