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

Abstract

To provide a substrate surface treatment method and a method for region selective film formation on substrate surface with which it is possible to form a film on a substrate surface which is composed of the polymerized condensate of a silylation agent and achieve property modification (e.g., imparting water repellency, obstructing film formation by ALD method) with different degrees of modification in accordance with the material quality of each region of the substrate surface having a plurality of regions, and provide a surface treatment agent which is used in these methods.SOLUTION: Provided is a surface treatment method including: a substrate preparation step for preparing a substrate that includes two or more regions differing from each other in the quality of surface material; an exposure step for exposing the substrate surface to a surface treatment agent; and a bake step for baking the substrate after the exposure step. A rinse step for rinsing the substrate surface with a liquid between the exposure step and the bake step is not included. The surface treatment agent contains a silylation agent (A) and does not contain a nitrogen-containing heterocyclic compound (B), the silylation agent (A) containing organo monosilane, in which two to four nitrogen atoms are bound to a silicon atom.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] In recent years, the trend of high integration and miniaturization of semiconductor devices has been increasing, and the miniaturization of patterned organic films serving as masks and patterned inorganic films formed by etching processes has been progressing. For this reason, film thickness control at the atomic layer level is required for organic films and inorganic films formed on semiconductor substrates. As a method for forming a thin film at the atomic layer level on a substrate, an atomic layer growth method (ALD (Atomic Layer Deposition) method; hereinafter, also simply referred to as the "ALD method") is known. The ALD method is known to have both high step coverage and film thickness controllability as compared with a general CVD (Chemical Vapor Deposition) method.

[0003] The ALD method is a thin film forming technique in which two types of gases mainly composed of elements constituting the film to be formed are alternately supplied onto a substrate, and the formation of a thin film in atomic layer units on the substrate is repeated a plurality of times to form a film having a desired thickness. In the ALD method, only the components of the source gas to the extent that one or several atomic layers are formed while the source gas is being supplied are adsorbed on the substrate surface, while the excess source gas does not contribute to growth, and the self-limiting function of growth is utilized. For example, when forming an Al2O3 film on a substrate, a source gas composed of TMA (TriMethyl Aluminum) and an oxidizing gas containing O are used. When forming a nitride film on a substrate, a nitriding gas is used instead of the oxidizing gas.

[0004] In recent years, attempts have been made to perform region-selective film formation on a substrate surface using the ALD method (see Patent Document 1 and Non-Patent Document 1). Accordingly, there has been a demand for a substrate having a surface selectively modified so as to be suitably applicable to selective film formation on a substrate by ALD method. As a method for obtaining such a substrate having a selectively modified surface, there is a surface treatment method for the surface of a substrate, which includes exposing the surface to a surface treatment agent containing a silylating agent (A) and a nitrogen-containing heterocyclic compound (B), the surface includes two or more regions, and the materials of adjacent regions among the two or more regions are different from each other, and by the reaction of the silylating agent with the two or more regions, the contact angles of water with respect to adjacent regions among the two or more regions are made different from each other (see Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] It is desirable that such a surface treatment agent containing a silylating agent has a high modification effect on the region of the substrate surface to be modified. In order to further increase the modification effect on the region of the substrate surface to be modified, it is conceivable to increase the molecular weight of the film formed on the region of the substrate surface to be modified by the surface treatment agent containing a silylating agent.

[0008] The present invention has been made in view of the above circumstances, and forms a film composed of a condensate of a polymerized silylating agent on the substrate surface, and modifies it with different degrees of modification according to the material of each region of the substrate surface having a plurality of regions (for example, imparting water repellency, imparting inhibitory properties for film formation by ALD method, etc.). An object is to provide a substrate surface treatment method, a region-selective film formation method for a substrate surface, and a surface treatment agent used therefor.

Means for Solving the Problems

[0009] The present inventors used a surface treatment agent containing a silylating agent (A) and not containing a nitrogen-containing heterocyclic compound (B), and the silylating agent (A) contains organomono silane. In the organomono silane, 2 to 4 nitrogen atoms are bonded to the silicon atom. After exposing the surface of the substrate to the surface treatment agent, the substrate is baked without rinsing, thereby forming a film composed of a condensate of a polymerized silylating agent on the substrate surface, and it was found that the degree of modification can be changed according to the material of the substrate surface, and the present invention has been completed. That is, the present invention is as follows.

[0010] The first aspect of the present invention includes a substrate preparation step of preparing a substrate having two or more regions with different surface materials from each other, an exposure step of exposing the surface of the substrate to a surface treatment agent, a baking step of baking the substrate after the exposure step, not including a rinsing step of rinsing the surface of the substrate with a liquid between the exposure step and the baking step, the surface treatment agent contains a silylating agent (A) and does not contain a nitrogen-containing heterocyclic compound (B), the silylating agent (A) contains organomono silane, in the organomono silane, 2 to 4 nitrogen atoms are bonded to the silicon atom, It is a substrate surface treatment method.

[0011] The second aspect of the present invention is a surface treatment step of treating the surface of the substrate by the substrate surface treatment method of the first aspect, A film forming step of forming a film on the surface of the substrate after the surface treatment step by atomic layer growth method is included. It is a method for selectively forming a film on a region of a substrate surface, in which the deposition amount of the material of the film varies selectively in different regions.

[0012] A third aspect of the present invention is a surface treatment agent used in the substrate surface treatment method of the first aspect, which contains a silylating agent (A) and does not contain a nitrogen-containing heterocyclic compound (B). The silylating agent (A) contains an organomono silane. In the organomono silane, 2 to 4 nitrogen atoms are bonded to the silicon atom, and it is a surface treatment agent.

Advantages of the Invention

[0013] According to the present invention, a film composed of a condensate of a polymerized silylating agent is formed on the substrate surface, and the substrate can be modified with different degrees of modification (for example, imparting hydrophobicity, imparting inhibitory properties for film formation by ALD method, etc.) according to the material of each region of the substrate surface having a plurality of regions.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention.

[0015] ≪Substrate Surface Treatment Method and Surface Treatment Agent Used in the Substrate Surface Treatment Method≫ The substrate surface treatment method of the first aspect is a surface treatment method for the surface of a substrate, which includes a substrate preparation step of preparing a substrate including two or more regions with different surface materials, an exposure step of exposing the surface of the substrate to a surface treatment agent, and a baking step of baking the substrate after the exposure step, and does not include a rinsing step of rinsing the surface of the substrate with a liquid between the exposure step and the baking step. And the surface treatment agent contains a silylating agent (A) and does not contain a nitrogen-containing heterocyclic compound (B). Further, the silylating agent (A) contains an organomono-silane, and in the organomono-silane, 2 to 4 nitrogen atoms are bonded to the silicon atom. Hereinafter, each step will be described.

[0016] <Substrate preparation step> In the substrate preparation step, a substrate including two or more regions with different surface materials is prepared. The substrate prepared in the substrate preparation step, that is, the substrate to be surface-treated in the substrate surface treatment method, is a substrate including two or more regions with different surface materials. Examples of the "substrate" include substrates used for manufacturing semiconductor devices, such as silicon (Si) substrates, silicon nitride (SiN) substrates, silicon oxide film (SiOx) substrates, tungsten (W) substrates, cobalt (Co) substrates, titanium nitride (TiN) substrates, tantalum nitride (TaN) substrates, germanium (Ge) substrates, silicon germanium (SiGe) substrates, aluminum (Al) substrates, nickel (Ni) substrates, ruthenium (Ru) substrates, copper (Cu) substrates, and the like. The "surface" of the substrate includes not only the surface of the substrate itself, but also the surfaces of patterned inorganic and organic layers provided on the substrate, and the surfaces of unpatterned inorganic or organic layers.

[0017] Examples of the patterned inorganic layer provided on the substrate include a patterned inorganic layer formed by creating an etching mask on the surface of the inorganic layer existing on the substrate by the photoresist method and then performing an etching process, and a patterned inorganic layer formed on the surface of the substrate by the atomic layer deposition method (ALD method). In addition, even when obtaining a patterned inorganic layer formed on the surface of the substrate by the ALD method, the surface treatment agent of this embodiment can be used. Examples of the inorganic layer include, in addition to the substrate itself, oxide films of elements constituting the substrate, and films or layers of inorganic substances such as SiN, SiOx, W, Mo, Co, TiN, TaN, Ge, SiGe, Al, Ni, Ru, Cu formed on the surface of the substrate. Such films or layers are not particularly limited, but examples include inorganic films or layers formed in the process of manufacturing a semiconductor device. Examples of the unpatterned inorganic layer provided on the substrate include inorganic films or layers made of the same material as the patterned inorganic layer provided on the substrate.

[0018] Examples of the patterned organic layer provided on the substrate include patterned resin layers formed on the substrate by photolithography using a photoresist or the like. Such a patterned organic layer can be formed, for example, by forming an organic layer that is a photoresist film on the substrate, exposing the organic layer through a photomask, and developing it. The organic layer may be provided not only on the surface of the substrate itself but also on the surface of a laminated film provided on the surface of the substrate. Such organic layers are not particularly limited, but examples include organic films provided to form an etching mask in the process of manufacturing a semiconductor device. Examples of the unpatterned organic layer provided on the substrate include organic films or layers made of the same material as the patterned organic layer provided on the substrate.

[0019] (Pretreatment of the substrate surface) The surface of the substrate may be pretreated. The treatment agent for pretreating the substrate surface (hereinafter sometimes referred to as the "pretreatment agent") is not particularly limited as long as it can remove the natural oxide film present on the substrate surface and impart hydroxyl groups to the substrate surface. By imparting hydroxyl groups in advance, the water repellency of the substrate surface after treatment with the surface treatment agent is improved. Specific examples of the pretreatment agent include peroxides such as hydrogen peroxide, perhalic acids such as periodic acid, oxoacids such as nitric acid and hypochlorous acid, phosphoric acid, citric acid, acetic acid, or hydrofluoric acid (HF). The pretreatment agent may be appropriately selected according to the type of substrate to be used. For example, in the case of a substrate containing W or Ru, at least one selected from the group consisting of hydrogen peroxide and perhalic acid is preferable. Further, at least one selected from the group consisting of hydrogen peroxide and perhalic acid is also preferable from the viewpoint of treating the metal surface without damaging the inorganic substances such as SiO2 and Al2O3 coexisting on the substrate surface. On the other hand, in the case of a substrate containing Cu, from the viewpoints of natural oxide film removability and improvement of the hydrophilicity of the substrate surface, it is preferable to use an HF aqueous solution, acetic acid, citric acid, phosphoric acid, nitric acid, or the like as the pretreatment agent. The pretreatment agent may be used alone or in combination of two or more. Note that after the pretreatment with the pretreatment agent, it is preferable to dry the substrate.

[0020] (Two or more regions with different materials from each other) It is preferable that at least two regions (for example, an insulator region and a metal region) with different materials from each other are adjacent. Here, "adjacent" includes the case where at least one region (for example, an insulator region) and at least one other region (for example, a metal region) share a boundary line and are adjacent, or the case where they are configured at positions adjacent or separated without sharing a boundary line.

[0021] The "two or more regions" of the substrate including two or more regions with different materials on the surface preferably include at least one insulator region and at least one metal region. The metal region is composed of a metal or a metal-containing compound having conductivity. The metal region may be defined as a conductor region with respect to the insulator region described later. As the metal, among the above-mentioned inorganic substances, copper (Cu), cobalt (Co), aluminum (Al), silver (Ag), nickel (Ni), titanium (Ti), gold (Au), chromium (Cr), molybdenum (Mo), tungsten (W), ruthenium (Ru), titanium nitride (TiN), tantalum nitride (TaN), etc. are preferable. The insulator region (also referred to as a high-resistance region) is composed of one or more insulating compounds or semiconductors selected from the group consisting of oxides, nitrides, carbides, carbonitrides, oxynitrides, oxycarbonitrides, and insulating resins. As the insulating compound, an oxide, nitride, carbide, carbonitride, oxynitride or oxycarbonitride is preferable. As the oxide, aluminum oxide (Al2O3), titanium oxide (TiO2), zirconium oxide (ZrO2), hafnium oxide (HfO2), tantalum oxide (Ta2O5), silicon oxide (SiOx (1≦X≦2)), fluorine-containing silicon oxide (SiOF), carbon-containing silicon oxide (SiOC) are preferable. As the nitride, for example, silicon nitride (SiN), boron nitride (BN) are preferable. As the carbide, silicon carbide (SiC) is preferable. As the carbonitride, silicon carbonitride (SICN) is preferable. As the oxynitride, silicon oxynitride (SiON) is preferable. As the oxycarbonitride, silicon oxycarbonitride (SiOCN) is preferable. Examples of the insulating resin include polyimide, polyester, plastic resin, etc. As the semiconductor, silicon or silicon doped with at least one selected from phosphorus, boron and germanium is preferable.

[0022] (Aspect where the substrate surface includes two regions) Among the two regions, the region having a tendency that the contact angle of water (preferably, hydrophobicity) is larger than that of the other region includes a region containing at least one selected from the group consisting of Si, SiN, SiOx, TiN, TaN, Ge and SiGe. As a region where the contact angle of water (preferably, hydrophobicity) tends to be smaller than that of the other region between the above two regions, examples of the region include a region containing at least one selected from the group consisting of W, Mo, Co, Al, Ni, Ru, Cu, TiN, and TaN.

[0023] For example, when one of the above two or more regions is defined as the first region and a region preferably adjacent thereto is defined as the second region, the materials of the first region and the second region are different. Here, the first region and the second region may or may not be each divided into a plurality of regions. Examples of the first region and the second region include, for example, a mode in which the surface of the substrate itself is defined as the first region and the surface of the inorganic layer formed on the surface of the substrate is defined as the second region, a mode in which the surface of the first inorganic layer formed on the surface of the substrate is defined as the first region and the surface of the second inorganic layer formed on the surface of the substrate is defined as the second region, and the like. In addition, modes in which an organic layer is formed instead of forming these inorganic layers can also be similarly cited. As a mode in which the surface of the substrate itself is defined as the first region and the surface of the inorganic layer formed on the surface of the substrate is defined as the second region, the surface of at least one substrate selected from the group consisting of Si substrate, SiN substrate, SiOx substrate, TiN substrate, TaN substrate, Ge substrate, and SiGe substrate is defined as the first region, and the surface of the inorganic layer containing at least one selected from the group consisting of W, Mo, Co, Al, Ni, Ru, Cu, TiN, and TaN formed on the surface of the above substrate is defined as the second region, which is preferable. In addition, as a mode in which the surface of the first inorganic layer formed on the surface of the substrate is defined as the first region and the surface of the second inorganic layer formed on the surface of the substrate is defined as the second region, the surface of the first inorganic layer containing at least one selected from the group consisting of SiN, SiOx, TiN, TaN, Ge, and SiGe formed on the surface of an arbitrary substrate (for example, Si substrate) is defined as the first region, and the surface of the second inorganic layer containing at least one selected from the group consisting of W, Mo, Co, Al, Ni, Ru, Cu, TiN, and TaN formed on the surface of the above substrate is defined as the second region, which is preferable.

[0024] The two regions included in the substrate surface preferably include an insulator region and a metal region. As an aspect of the substrate surface composed of the two regions in this case, for example, one of the two regions is a metal region as the first region, and preferably the region adjacent thereto is an insulator region as the second region. Here, the first region and the second region may or may not be divided into a plurality of regions respectively. Examples of the first region and the second region include, for example, a mode in which the surface of the substrate itself is a metal region as the first region and a layer made of an insulator formed on the surface of the substrate is an insulator region as the second region; a mode in which the surface of the substrate itself is an insulator region as the first region and a layer made of metal formed on the surface of the substrate is a metal region as the second region; a mode in which a layer made of metal formed on the surface of the substrate is a metal region as the first region and a layer made of an insulator formed on the surface of the substrate is an insulator region as the second region; a mode in which a part of the surface of an insulating substrate is a metal region as the first region, and a layer made of an insulator formed on at least a part of the surface of the substrate that is not the metal region and / or at least a part of the surface of the substrate that is not the metal region (or the entire surface of the substrate that is not the metal region) is an insulator region as the second region, and the like.

[0025] (Aspect where the substrate surface includes three or more regions) When one of the two or more regions is the first region, preferably the region adjacent thereto is the second region, and further preferably the region adjacent to the second region is the third region, the material is different between the first region and the second region, and the material is different between the second region and the third region. Here, the material may or may not be different between the first region and the third region. Also, the first region, the second region, and the third region may or may not be divided into a plurality of regions respectively. Examples of the first region, the second region, and the third region include, for example, a mode in which the surface of the substrate itself is the first region, the surface of the first inorganic layer formed on the surface of the substrate is the second region, and the surface of the second inorganic layer formed on the surface of the substrate is the third region. In addition, modes in which an organic layer is formed instead of forming these inorganic layers can also be similarly cited. Further, modes including both an inorganic layer and an organic layer formed by changing only one of the second inorganic layer and the third inorganic layer to an organic layer can also be similarly cited. The surface of an arbitrary substrate (for example, a Si substrate) itself is the first region, the surface of the first inorganic layer containing at least one selected from the group consisting of SiN, SiOx, TiN, TaN, Ge, and SiGe formed on the surface of the substrate is the second region, and the surface of the second inorganic layer containing at least one selected from the group consisting of W, Mo, Co, Al, Ni, Ru, Cu, TiN, and TaN formed on the surface of the substrate is the third region.

[0026] It is preferable that the three or more regions included in the substrate surface include at least one insulator region and at least one metal region. In this case, examples of the substrate surface composed of three or more regions include, for example, a mode in which one of the two or more regions is a metal region as the first region, a region preferably adjacent thereto is an insulator region as the second region, and a region preferably adjacent to the second insulator region is a metal region as the third region; a mode in which one of the two or more regions is an insulator region as the first region, a region preferably adjacent thereto is a metal region as the second region, and a region preferably adjacent to the second metal region is an insulator region as the third region; and a mode in which one of the two or more regions is a metal region as the first region, a region preferably adjacent thereto is a metal region as the second region, and a region preferably adjacent to the second metal region is an insulator region as the third region. Here, the materials of the first region and the third region are different. In addition, the first region, the second region, and the third region may or may not be divided into a plurality of regions, respectively. Examples of the first region, the second region, and the third region include, for example, a mode in which the surface of the substrate itself is a metal region as the first region, an insulator region surface formed on the surface of the substrate, which is preferably adjacent to the substrate, is the second region, and a metal region surface formed on the surface of the substrate, which is preferably adjacent to the second region, is the third region; a mode in which the surface of the substrate itself is an insulator region as the first region, a metal region surface formed on the surface of the substrate, which is preferably adjacent to the substrate, is the second region, and an insulator region surface formed on the surface of the substrate, which is preferably adjacent to the second region, is the third region, and the like. The same concept can be applied when there are four or more regions. The upper limit value of the number of regions with different materials is not particularly limited as long as the effects of the present invention are not impaired. For example, it is 7 or less, or 6 or less, and typically 5 or less.

[0027] <Exposure step> In the exposure step, the surface of the substrate prepared in the substrate preparation step is exposed to a surface treatment agent. (Surface treatment agent) The surface treatment agent used in the exposure step contains a silylating agent (A) and does not contain a nitrogen-containing heterocyclic compound (B). The silylating agent (A) contains an organomono silane, and in the organomono silane, 2 to 4 nitrogen atoms are bonded to the silicon atom. That is, the silylating agent (A) contains an organomono silane in which 2 to 4 nitrogen atoms are bonded to the silicon atom. Hereinafter, each component will be described.

[0028] [Silylating agent (A)] The organomono silane in which 2 to 4 nitrogen atoms contained in the silylating agent (A) are bonded to the silicon atom means a compound having one silicon atom and 2 to 4 nitrogen atoms bonded to the silicon atom. By using an organomono-silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom as the silylating agent (A), the organomono-silane is bonded to the substrate surface by the exposure of the surface treatment agent in the exposure step, and it is presumed that the organomono-silanes react with each other during baking in the subsequent baking step to form a polymer of the organomono-silane on the substrate surface. In the exposure step, the above organomono-silane can be bonded to the surface of the substrate, whereby a monomolecular film derived from the above organomono-silane can be formed on the substrate surface. Such a monomolecular film is preferably a self-assembled monolayer (SAM) in which a network of siloxane bonds is formed in the plane direction of the substrate.

[0029] Examples of the organomono-silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom and which is included in the silylating agent (A) include compounds represented by the following formula (1). [Chemical formula] (In formula (1), R 1 and R 2 each independently represent a hydrogen atom, a nitrogen-containing group or an organic group, and the total number of carbon atoms contained in R 1 and R 2 is 1 or more. R 3 ~R 6 each independently represent a hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, an acetyl group, or a saturated or unsaturated heterocycloalkyl group.)

[0030] In formula (1), R 3 ~R 6 each independently represent a hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, an acetyl group (CH3CO-), or a saturated or unsaturated heterocycloalkyl group. R 3 ~R 6As the saturated or unsaturated alkyl group, a saturated or unsaturated alkyl group having 1 to 10 carbon atoms is preferable, and specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a vinyl group, and an aryl group. R 3 ~R 6 As the saturated or unsaturated cycloalkyl group, a saturated or unsaturated alkyl group having 3 to 10 carbon atoms is preferable, and specific examples include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, etc. R 3 ~R 6 As the saturated or unsaturated heterocycloalkyl group, a piperidino group, a morpholino group, etc. can be mentioned.

[0031] In formula (1), R 1 and R 2 each independently represent a hydrogen atom, a nitrogen-containing group or an organic group, and the total number of carbon atoms contained in R 1 and R 2 is 1 or more. R 1 and R 2 As the nitrogen-containing group for R 7 and R 8 -NR 7 and R 8 can be mentioned. R 7 and R 8 each independently represent a hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, an acetyl group, or a saturated or unsaturated heterocycloalkyl group. R 3 ~R 6 The saturated or unsaturated alkyl group, saturated or unsaturated cycloalkyl group, and saturated or unsaturated heterocycloalkyl group for R R 1 and R 2Examples of the organic group as such include a saturated or unsaturated alkyl group in which some or all of the hydrogen atoms may be substituted with fluorine atoms, and an aromatic hydrocarbon group in which some or all of the hydrogen atoms may be substituted with fluorine atoms, etc. R 1 and R 2 The saturated or unsaturated alkyl group as such is the same as the saturated or unsaturated alkyl group described for the above R 3 ~R 6 above. R 1 and R 2 Examples of the aromatic hydrocarbon group as such include a phenyl group, a naphthyl group, etc. R 1 and R 2 The total number of carbon atoms contained in R

[0032] Specific examples of the compound represented by formula (1) include the following compounds.

Chemical formula

[0033] The silylating agent (A) may contain one or more organomono silanes in which 2 to 4 nitrogen atoms are bonded to a silicon atom, and may contain one or more compounds represented by formula (1). In addition, the silylating agent (A) may contain a silylating agent other than the organomono silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom, but it is preferably free of a silylating agent other than the organomono silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom.

[0034] The content of the organomono silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom in the surface treatment agent is not particularly limited as long as the effects of the present invention are not impaired, but is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 1.0% by mass or more, and particularly preferably 10% by mass or more with respect to the total amount of the above surface treatment agent. In addition, the upper limit of the content of organomono-silane in which two or more and four or less nitrogen atoms in the surface treatment agent are bonded to silicon atoms is not particularly limited as long as the effects of the present invention are not impaired. For example, it is 100% by mass or less, 90% by mass or less, or 80% by mass or less.

[0035] [Nitrogen-containing heterocyclic compound (B)] The surface treatment agent does not contain a nitrogen-containing heterocyclic compound (B). The nitrogen-containing heterocyclic compound (B) is a compound containing a nitrogen atom in its ring structure. In this embodiment, by using a surface treatment agent containing a specific silylating agent (A) and not containing a nitrogen-containing heterocyclic compound (B), after exposing the surface of the substrate to the surface treatment agent and without rinsing, baking the substrate can form a film (for example, a thick film composed of a condensate (polymer) of the polymerized silylating agent (A)) on the substrate surface, and depending on the material of the substrate surface, the degree of modification such as water repellency and inhibition of film formation by the ALD method can be changed.

[0036] [Solvent (S)] The surface treatment agent may contain a solvent, but may not substantially contain a solvent. From the viewpoint of ease of surface treatment of the substrate by methods such as the dipping method and the spin coating method, it is preferable for the surface treatment agent to contain a solvent. Note that when the surface treatment agent does not substantially contain a solvent, the content of the solvent in the surface treatment agent is 5% by mass or less, preferably 1% by mass or less, and more preferably 0.1% by mass or less. When the surface treatment agent contains a solvent, the blending amount of the solvent may be appropriately adjusted, for example, in the range of 0.1% by mass or more and 99.99% by mass or less, and the balance of the silylating agent (A) contained in the surface treatment agent may be taken as the solvent amount.

[0037] Specific examples of the solvent include sulfoxides such as dimethyl sulfoxide; Sulfones such as dimethyl sulfone, diethyl sulfone, bis(2-hydroxyethyl) sulfone, and tetramethylene sulfone; Amides such as N,N-dimethylformamide, N-methylformamide, N,N-dimethylacetamide, N-methylacetamide, N,N-diethylacetamide; Imidazolidinones such as 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-diisopropyl-2-imidazolidinone; Dialkyl glycol ethers such as dimethyl glycol, dimethyl diglycol, dimethyl triglycol, methylethyl diglycol, diethyl glycol, triethylene glycol butyl methyl ether; Monoalcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, 3-methyl-3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, methyl isobutyl carbinol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethyl carbinol, diacetone alcohol, cresol; (Poly)alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether; (Poly)alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate; Other ethers such as dimethyl ether, diethyl ether, methyl ethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisoamyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol monobutyl ether, diethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran; Ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone; Alkyl lactates such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate; ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxy-1-butyl acetate, 3-methyl-3-methoxybutyl propionate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-pentyl acetate, n-hexyl acetate, n-heptyl acetate, n-octyl acetate, n-pentyl formate, i-pentyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, methyl n-octanoate, methyl decanoate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl 2-oxobutanoate, dimethyl adipate, propylene glycol diacetate and other esters; Lactones such as β-propiolactone, γ-butyrolactone, δ-pentylolactone; Linear, branched or cyclic aliphatic hydrocarbons such as n-hexane, n-heptane, n-octane, n-nonane, methyloctane, n-decane, n-undecane, n-dodecane, 2,2,4,6,6-pentamethylheptane, 2,2,4,4,6,8,8-heptamethylnonane, cyclohexane, methylcyclohexane; Aromatic hydrocarbons such as benzene, toluene, benzotrifluoride, xylene, 1,3,5-trimethylbenzene, naphthalene, decahydronaphthalene; Terpenes such as p-menthane, diphenylmethane, limonene, terpinene, bornane, norbornane, pinane; Amines such as diisopropylamine, ethylenediamine, diethylenetriamine; etc. These solvents can be used alone or in admixture of two or more. Among them, it is preferable that the solvent contains an alkylene glycol monoalkyl ether acetate.

[0038] The surface treatment agent can be manufactured by mixing the contained components.

[0039] (Exposure method) As a method of exposing the surface of the substrate to the surface treatment agent, a surface treatment agent (typically a liquid surface treatment agent) which may or may not contain a solvent can be applied (e.g., coated) to the surface of the substrate by means such as an immersion method, a spin coating method, a roll coating method, and a doctor blade method, etc. (e.g., coating) and exposed, or a method of applying the vapor of the surface treatment agent to the surface of the substrate and exposing it can be mentioned. As a method of exposing the surface of the substrate to the surface treatment agent, the spin coating method is preferable. As the exposure temperature, for example, it is 10°C or higher and 40°C or lower, preferably 15°C or higher and 35°C or lower, more preferably 20°C or higher and 30°C or lower. As the above exposure time, 10 seconds or more is preferable, and 30 seconds or more is more preferable. The upper limit value of the above exposure time is not particularly limited, but for example, it is 10 minutes or less, etc., and typically 5 minutes or less.

[0040] <Baking process> In the baking process, after the exposure process, the substrate is baked (heated). By baking, organomono silanes in which 2 or more and 4 or less nitrogen atoms contained in the surface treatment agent are bonded to silicon atoms react with each other, and a polymer of the organomono silane is formed on the substrate surface. In this embodiment, a rinsing process of rinsing the surface of the substrate with a liquid is not included between the exposure process and the baking process.

[0041] The baking temperature is preferably 140°C or higher and 500°C or lower, more preferably 150°C or higher and 400°C or lower. Also, the baking time is preferably 0.5 minutes or more and 50 minutes or less, more preferably 1 minute or more and 30 minutes or less.

[0042] Thus, by using a surface treatment agent containing an organomono-silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom and not containing a nitrogen-containing heterocyclic compound (B), exposing the surface of the substrate to the surface treatment agent, and then baking the substrate without rinsing, as shown in the examples described later, a film composed of a condensate of a polymerized silylating agent (A) is formed on the substrate surface, and the degree of modification (such as the degree of water repellency or inhibition of film formation by ALD method) can be varied according to the material of the substrate surface. Thus, the mechanism by which a film composed of a condensate of a polymerized silylating agent (A) is formed on the substrate surface and the degree of modification can be varied according to the material of the substrate surface is unclear, but is presumed as follows. By exposing the surface treatment agent in the exposure step, an organomono-silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom binds to the substrate surface, and by baking in the subsequent baking step, the organomono-silanes react with each other without being inhibited by the nitrogen-containing heterocyclic compound (B), thereby forming a polymer (condensate of the silylating agent) of the organomono-silane bonded to the substrate surface with increased molecular weight. Since the degree of formation of the polymer of the organomono-silane bonded to the substrate surface depends on the material of the substrate, it is possible to modify (for example, impart hydrophobicity or inhibition of film formation by ALD method) with different degrees of modification according to the material of each region of the substrate surface having a plurality of regions.

[0043] On the other hand, when the nitrogen-containing heterocyclic compound (B) is included, when the substrate is not baked after exposing the surface of the substrate to the surface treatment agent, or when the substrate is rinsed before baking the substrate after exposing the surface of the substrate to the surface treatment agent, the polymerization of the film formed on the substrate surface is insufficient, and it is difficult to modify (for example, impart hydrophobicity or inhibition of film formation by ALD method) with different degrees of modification according to the material of each region of the substrate surface having a plurality of regions. Also, when the silylating agent is not an organomono-silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom, the polymerization of the film formed on the substrate surface is insufficient, and it is difficult to impart, for example, different inhibitions of film formation by ALD method according to the material of each region of the substrate surface having a plurality of regions.

[0044] After the baking process, rinsing (cleaning) with a liquid such as water or an activator rinse may be performed as necessary, and drying by nitrogen blowing or the like may also be performed.

[0045] The contact angle of the substrate surface after the surface treatment of this embodiment with respect to water can be, for example, 85° or more and 140° or less. And in this embodiment, since the contact angles of water in the two or more regions can be made different from each other by the above surface treatment, it is possible to improve the selective water repellency (hydrophobicity) between the two or more regions. The difference in the contact angle of water between the two or more regions is not particularly limited as long as the effects of the present invention are not impaired. For example, it can be 50° or more, and can also be 70° or more, 80° or more, or 90° or more. The upper limit value of the contact angle difference is not particularly limited as long as the effects of the present invention are not impaired. For example, it can be 120° or less or 100° or less.

[0046] When a film is formed on the substrate surface after the surface treatment (modification) of this embodiment by ALD method, the thickness of the formed film is, for example, 6.0 nm or less, and can also be 5.0 nm or less, 3.0 nm or less, 2.0 nm or less, 1.0 nm or less, or 0.62 nm or less. And in this embodiment, when a film is formed on the substrate surface after the surface treatment (modification) of this embodiment by ALD method, since the film formation inhibition of the ALD method in the two or more regions can be made different from each other, it is possible to improve the region selectivity (ALD selectivity) of film formation by ALD method between the two or more regions. The difference in the thickness of the film formed by ALD method between the two or more regions is not particularly limited as long as the effects of the present invention are not impaired. For example, it can be 2.0 nm or more, and can also be 3.0 nm or more. The upper limit value of the difference in the thickness of the film formed by ALD method is not particularly limited as long as the effects of the present invention are not impaired. For example, it can be 4.5 nm or less.

[0047] ≪Region-selective Film Formation Method for Substrate Surface≫ Next, a method for selectively depositing a film on a substrate using the surface treatment method of the first aspect will be described. In this aspect, the method for selectively depositing a film on the substrate surface is as follows. A surface treatment step of treating the surface of the substrate by the surface treatment method of the first aspect, and a film formation step of forming a film on the surface of the substrate after the surface treatment step by an ALD method (atomic layer growth method), and the deposition amount of the film material is made to vary selectively in different regions.

[0048] As a result of the surface treatment by the method of the first aspect, the contact angle of water (preferably, hydrophobicity) between the two or more regions will be different. In this aspect, the deposition amount of the film-forming material can be made to selectively differ in different regions on the substrate surface between the two or more regions. Specifically, in a region where the contact angle of water (preferably, hydrophobicity) between the two or more regions is larger than that of the other region, it becomes difficult for the film-forming material by the ALD method to adsorb (preferably, chemisorb) on the region on the substrate surface. As a result of a difference occurring in the deposition amount of the film-forming material between the two or more regions, it is preferable that the deposition amount of the film-forming material selectively differs in different regions on the substrate. Examples of the chemisorption include chemisorption with a hydroxyl group.

[0049] Examples of a region where the contact angle of water (preferably, hydrophobicity) between the two or more regions tends to be larger than that of the other region include a region containing at least one selected from the group consisting of Si, SiN, SiOx, TiN, TaN, Ge, and SiGe. Examples of a region where the contact angle of water (preferably, hydrophobicity) between the two or more regions tends to be smaller than that of the other region include a region containing at least one selected from the group consisting of W, Mo, Co, Al, Ni, Ru, Cu, TiN, and TaN.

[0050] Here, as shown in the examples and comparative examples described later, even when the contact angles of water in two or more regions are similar, there may be a significant difference in the deposition amount of the film-forming material by the ALD method. Therefore, in addition to the contact angles of water in two or more regions, there are factors that affect the deposition amount of the film-forming material by the ALD method, and this factor is considered to be the molecular weight of the film formed on the substrate surface. The surface treatment method of the first aspect is presumed to have an extremely excellent effect on the area selectivity of film formation by the ALD method on the substrate surface after modification (after surface treatment) in order to increase the molecular weight of the film formed on the substrate surface.

[0051] (Film formation by ALD method) The film formation method by the ALD method is not particularly limited, but it is preferably a thin film formation method by adsorption (preferably chemisorption) using at least two gas-phase reactants (hereinafter simply referred to as "precursor gases"). Specifically, methods including the following steps (a) and (b) and repeating the following steps (a) and (b) at least once (one cycle) until a desired film thickness is obtained can be mentioned. (a) A step of exposing the substrate surface-treated by the method according to the first aspect to a pulse of the first precursor gas, and (b) A step of exposing the substrate to a pulse of the second precursor gas following the step (a).

[0052] Before the step (b) after the step (a), a plasma treatment step, a step of removing or exhausting (purging) the first precursor gas and its reactants with a carrier gas, the second precursor gas, etc. may or may not be included. After the step (b), a plasma treatment step, a step of removing or purging the second precursor gas and its reactants with a carrier gas, etc. may or may not be included. Examples of the carrier gas include inert gases such as nitrogen gas, argon gas, and helium gas.

[0053] Each pulse and each layer formed for each cycle are preferably self-controlled, and it is more preferable that each layer formed is a single atomic layer. The film thickness of the above single atomic layer can be, for example, 5 nm or less, preferably 3 nm or less, more preferably 1 nm or less, and still more preferably 0.5 nm or less.

[0054] Examples of the first precursor gas include organometals, metal halides, metal oxyhalides, etc. Specifically, tantalum pentaethoxide, tetrakis(dimethylamino)titanium, pentakis(dimethylamino)tantalum, tetrakis(dimethylamino)zirconium, tetrakis(dimethylamino)hafnium, tetrakis(dimethylamino)silane, pecopper hexafluoroacetylacetonate vinyltrimethylsilane, Zn(C2H5)2, Zn(C2H5)2, Zn(CH3)2, TMA (trimethylaluminum), TaCl5, WF6, WOCl4, CuCl, ZrCl4, AlCl3, TiCl4, SiCl4, HfCl4, etc. can be mentioned.

[0055] Examples of the second precursor gas include a precursor gas capable of decomposing the first precursor or a precursor gas capable of removing the ligand of the first precursor. Specifically, H2O, H2O2, O2, O3, NH3, H2S, H2Se, PH3, AsH3, C2H4, or Si2H6, etc. can be mentioned.

[0056] The exposure temperature in step (a) is not particularly limited, but is, for example, 100°C or higher and 800°C or lower, preferably 150°C or higher and 650°C or lower, more preferably 200°C or higher and 500°C or lower, and still more preferably 225°C or higher and 375°C or lower.

[0057] The exposure temperature in step (b) is not particularly limited, and examples include a temperature substantially equal to or higher than the exposure temperature in step (a).

[0058] The film formed by ALD method is not particularly limited, and examples include films containing pure elements (e.g., Si, Cu, Ta, W), films containing oxides (e.g., SiO2, GeO2, HfO2, ZrO2, Ta2O5, TiO2, Al2O3, ZnO, SnO2, Sb2O5, B2O3, In2O3, WO3), films containing nitrides (e.g., Si3N4, TiN, AlN, BN, GaN, NbN), films containing carbides (e.g., SiC), films containing sulfides (e.g., CdS, ZnS, MnS, WS2, PbS), films containing selenides (e.g., CdSe, ZnSe), films containing phosphides (GaP, InP), films containing arsenides (e.g., GaAs, InAs), or mixtures thereof, etc.

Example

[0059] Hereinafter, the present invention will be described more specifically with reference to examples, but the scope of the present invention is not limited to these examples.

[0060] (Measurement of film thickness formed by surface treatment) [Example 1] (Preparation of surface treatment agent) Bis(dimethylamino)dimethylsilane (BDMADMS) at 100% by mass was used as the surface treatment agent of Example 1.

[0061] (Surface treatment and measurement of surface treatment film thickness) Using the obtained surface treatment agent of Example 1, the surface of a silicon thermal oxide film substrate (SiOx) was treated according to the following method. Specifically, at room temperature (25 °C), the surface treatment agent was applied (exposed) to the surface of the substrate whose thickness had been measured in advance by fluorescence X-ray analysis by spin coating (1500 rpm, 0.5 minutes), and then dried by spin drying (1000 rpm, 0.5 minutes). Next, the substrate after spin drying was placed in a heating furnace and heated (baked) at 300 °C for 1 minute. Next, while rotating the baked substrate, isopropanol was dropped onto the substrate and washed (rinsed) for 1 minute, then deionized distilled water was dropped and washed (rinsed) for 1 minute, and then spin-dried as it was. The washing was performed at room temperature. Note that no washing by rinsing with a liquid was performed between the application (exposure) of the surface treatment agent to the substrate and the baking. The thickness of the entire substrate after washing and spin-drying was measured by fluorescent X-ray analysis, and the difference from the thickness of the original substrate was confirmed to be 0.96 nm. That is, the thickness of the film formed on the substrate surface by the surface treatment (surface treatment film thickness) was 0.96 nm.

[0062] [Comparative Example 1] Surface treatment and surface treatment film thickness measurement were performed in the same manner as in Example 1, except that a surface treatment agent in which BDMADMS and imidazole were uniformly mixed so that the mass ratio was 5:3.5 was used. As a result, the difference between the thickness of the entire substrate after washing and spin-drying and the thickness of the original substrate was 0.84 nm.

[0063] [Comparative Example 2] Surface treatment and surface treatment film thickness measurement were performed in the same manner as in Example 1, except that tetramethyldisilazane (TMDS) was used instead of BDMADMS. As a result, the difference between the thickness of the entire substrate after washing and spin-drying and the thickness of the original substrate was 0.10 nm.

[0064] From the results of Example 1 and Comparative Examples 1 and 2, Example 1, which was exposed and baked using a surface treatment agent containing an organomono silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom as the silylating agent (A) and not containing imidazole which is a nitrogen-containing heterocyclic compound (B), shows that the film formed by the surface treatment is thicker than that in Comparative Example 1 containing imidazole which is a nitrogen-containing heterocyclic compound (B) and Comparative Example 2 using TMDS as the silylating agent. Therefore, it can be said that in Example 1, the film derived from the silylating agent (A) has a higher molecular weight than in Comparative Examples 1 and 2.

[0065] [Example 2] (Preparation of Surface Treatment Agent) To the solvent propylene glycol monomethyl ether acetate (S1), bisdimethylaminodimethylsilane (BDMADMS), which is a silylating agent (A), was added so as to be 10% by mass and uniformly mixed to prepare the surface treatment agent of Example 2.

[0066] (Surface treatment) Using the obtained surface treatment agent of Example 2, the surfaces of the silicon thermal oxide film substrate (SiO x ), tungsten substrate (W), and molybdenum substrate (Mo) were surface-treated according to the following method. Specifically, at room temperature (25 °C), the above surface treatment agent was applied (exposed) to the surface of each substrate by the spin coating method (1500 rpm, 0.5 minutes), and then dried by spin drying (1000 rpm, 0.5 minutes). Next, the substrate after spin drying was placed in a heating furnace and heated (baked) at 300 °C for 1 minute. Next, while rotating the baked substrate, isopropanol was dropped onto the substrate and washed (rinsed) for 1 minute, and then ion-exchanged distilled water was dropped and washed (rinsed) for 1 minute. The washing was performed at room temperature. Note that no washing by rinsing with a liquid was performed between the application (exposure) of the surface treatment agent to the substrate and the baking.

[0067] [Comparative Example 3] A surface-treated substrate was obtained in the same manner as in Example 2, except that tetramethyldisilazane (TMDS) was used instead of bisdimethylaminodimethylsilane (BDMADMS) as the silylating agent (A).

[0068] [Comparative Example 4] Silicon thermal oxide film substrates (SiO x ), tungsten substrates (W), and molybdenum substrates (Mo) without surface treatment were used as the substrates of Comparative Example 4.

[0069] [Measurement of water contact angle] The water contact angles of the surface-treated substrates obtained in Example 2 and Comparative Example 3 and the substrate of Comparative Example 4 were measured. The contact angle of water was measured using Dropmaster700 (manufactured by Kyowa Interface Science Co., Ltd.). Pure water was dropped as droplets (2.0 μL) onto the surface of the substrate, and the contact angle 2 seconds after dropping was measured. The results are shown in Table 1.

[0070] <ALD Film Deposition Test of Al2O3> On the surfaces of the surface-treated substrates obtained in Example 2 and Comparative Example 3 and the substrate of Comparative Example 4, ALD cycle treatment was performed 45 times under the following conditions to form an Al2O3 film. The film thickness of the formed Al2O3 film was measured by fluorescent X-ray analysis. The results are shown in Table 1. · Atomic layer deposition (ALD) apparatus: AT-410 (manufactured by Anric Technologies) · Chamber temperature: 150 °C · Precursors: Trimethylaluminum and H2O

[0071]

Table 1

[0072] As is clear from the results shown in Table 1 above, Example 2, which was exposed and baked using a surface treatment agent containing an organomono silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom as the silylating agent (A) and not containing a nitrogen-containing heterocyclic compound (B), and Comparative Example 3, which was exposed and baked using a surface treatment agent containing an organodisilane in which only 1 nitrogen atom is bonded to a silicon atom and not containing an organomono silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom as the silylating agent (A), both hydrophobize the insulator substrate (SiO x ) but do not hydrophobize the metal substrates (W, Wo), and the difference in the water contact angle between the insulator substrate (SiO x ) and the metal substrates (W, Wo) was large. The degree of hydrophobization (water contact angle) of the insulator substrate (SiO x ) in Example 2 and Comparative Example 3 was about the same. Therefore, it can be said that Example 2 and Comparative Example 3 can selectively hydrophobize the insulator substrate (SiO x ) with respect to the metal substrates (W, Wo).

[0073] On the other hand, in the ALD film formation test, when a film with a thickness of 5 nm was formed by 45 cycles of ALD, the thickness of the Al2O3 film on the insulator substrate (SiO x ) in Example 2 was about 1.4 nm, which was less than half of the film thickness in Comparative Example 3. Therefore, in Example 2, it can be said that the ALD film formation on the insulator substrate (SiO x ) was significantly inhibited compared to Comparative Example 3. Also, in the ALD film formation test, the ALD film formation on the metal substrates (W, Wo) was hardly inhibited in both Example 2 and Comparative Example 3. Therefore, it can be said that Example 2 can selectively inhibit the ALD film formation on the insulator substrate (SiO x ) with respect to the metal substrates (W, Wo) more than Comparative Example 3 with the same degree of water repellency as Example 1. This is presumably because, similar to the fact that the film derived from the silylating agent (A) has a higher molecular weight in Example 1 than in Comparative Example 2 using TMDS, the film derived from the silylating agent (A) has a higher molecular weight in Example 2 than in Comparative Example 3 using TMDS.

[0074] [Examples 3 to 10] Surface treatment agents were prepared and surface treatment was carried out in the same manner as in Example 2, except that the following S2 to S9 were used instead of propylene glycol monomethyl ether acetate (S1) as the solvent. The solvents used are shown in Table 2. S2: Methyl ethyl ketone S3: Diisopropyl ether S4: Cyclohexane S5: n-Decane S6: Diisopropylamine S7: Dimethylformamide S8: Ethylenediamine S9: Diethylenetriamine

[0075] For the surface-treated substrates obtained in Examples 3 to 10, <Measurement of water contact angle> was carried out in the same manner as in Example 2. The results of Examples 3 to 10, together with the results of Example 2 and Comparative Example 4, are shown in Table 2. In any of the examples, the metal substrates (W, Wo) were not made water-repellent.

[0076]

Table 2

[0077] As is clear from the results shown in Table 2 above, in Examples 3 to 10 where S2 to S9 were used instead of S1 as the solvent, similar to Example 2 using S1, the insulator substrate (SiO x ) is rendered water-repellent, but the metal substrates (W, Wo) are not rendered water-repellent, and it can be said that the insulator substrate (SiO x ) can be selectively rendered water-repellent with respect to the metal substrates (W, Wo).

[0078] Also, in Examples 3 to 10 where S2 to S9 were used instead of S1 as the solvent, similar to Example 2 using S1, in the ALD film formation test, while the ALD film formation on the insulator substrate (SiO x ) is significantly inhibited, the ALD film formation on the metal substrates (W, Wo) is not inhibited, and it is presumed that the ALD film formation on the insulator substrate (SiO x ) can be selectively inhibited with respect to the metal substrates (W, Wo). This is presumed to be because, similar to Example 1, the film derived from the silylating agent (A) has a high molecular weight.

[0079] [Examples 11 to 17] (Surface treatment) Using the surface treatment agent of Example 2, the surface treatment of a silicon thermal oxide film substrate (SiO x ), a tungsten substrate (W), and a molybdenum substrate (Mo) was performed according to the following method. Specifically, each substrate was immersed (exposed) in each of the above surface treatment agents at room temperature (25°C) for 1 minute, then the substrate was taken out and dried by a nitrogen stream. Next, the substrate dried by a nitrogen stream was placed in a heating furnace and heated (baked) at the temperature and for the time described in Table 3. Subsequently, the baked substrate was immersed in isopropanol and stirred for 1 minute for cleaning (rinsing), and then rinsed with ion-exchanged distilled water for 1 minute. The cleaning was performed at room temperature. Note that no liquid rinsing was performed between the application (exposure) of the surface treatment agent to the substrate and baking. The cleaned substrate was dried by a nitrogen stream to obtain a surface-treated substrate.

[0080] [Comparative Example 5] A substrate obtained in the same manner as the above surface treatment except that baking was not performed was used as the substrate of Comparative Example 5.

[0081] For the surface-treated substrates obtained in Examples 11 to 17 and the substrate of Comparative Example 5, <measurement of water contact angle> was performed in the same manner as in Example 2. The results are shown in Table 3. Note that in any of the examples, the metal substrates (W, Wo) were not made water-repellent.

[0082]

Table 3

[0083] As is clear from the results shown in Table 3 above, even when the baking conditions are changed to a baking temperature of 150°C or higher and 400°C or lower and a baking time of 1 minute or longer and 30 minutes or shorter, similar to Example 2, the insulator substrate (SiO x ) becomes water-repellent, but the metal substrates (W, Wo) do not become water-repellent, and it can be said that the insulator substrate (SiO x ) can be selectively made water-repellent with respect to the metal substrates (W, Wo). Also, even when the baking conditions are changed to a baking temperature of 150°C or higher and 400°C or lower and a baking time of 1 minute or longer and 30 minutes or shorter, similar to Example 2, in the ALD film formation test, the ALD film formation on the insulator substrate (SiO x ) is significantly inhibited, while the ALD film formation on the metal substrates (W, Wo) is not inhibited, and it is presumed that the ALD film formation on the insulator substrate (SiO x ) can be selectively inhibited with respect to the metal substrates (W, Wo). This is presumed to be because, similar to Example 1, the film derived from the silylating agent (A) has a high molecular weight.

[0084] [Examples 18 to 25] The surface treatment agent was prepared and the surface treatment was carried out in the same manner as in Example 2, except that the concentration of bisdimethylaminodimethylsilane (BDMADMS), which is the silylating agent (A) in the surface treatment agent, was set to the concentration (mass%) shown in Table 4. In Example 25 where the concentration of bisdimethylaminodimethylsilane (BDMADMS) was 100% by mass, a surface treatment agent consisting only of bisdimethylaminodimethylsilane without a solvent was used.

[0085] [Comparative Example 6] The surface treatment agent was prepared and the surface treatment was carried out in the same manner as in Example 25, except that baking was not performed.

[0086] For the surface-treated substrates obtained in Examples 18 to 25 and Comparative Example 6, <Measurement of water contact angle> was carried out in the same manner as in Example 1. The results of Examples 18 to 25 and Comparative Example 6 are shown in Table 4 together with the results of Comparative Example 4. In any of the examples, the metal substrates (W, Wo) were not made water-repellent.

[0087]

Table 4

[0088] As is clear from the results shown in Table 4 above, even when the concentration of the silylating agent is changed to 10.0% by mass or more and 100% by mass or less, similar to Example 2 etc., the insulator substrate (SiO x ) is made water-repellent, but the metal substrates (W, Wo) are not made water-repellent, and it can be said that the insulator substrate (SiO x ) can be selectively made water-repellent with respect to the metal substrates (W, Wo). Also, if the concentration of the silylating agent is 0.6% by mass or more, it can be said that water-repellency equal to or higher than the case where the concentration of the silylating agent is 100% by mass and baking is not performed can be achieved. Also, even when the concentration of the silylating agent is changed to 0.6% by mass or more and 100% by mass or less, similar to Example 2 etc., in the ALD film formation test, the insulator substrate (SiO x) significantly inhibits the ALD film formation above, and does not inhibit the ALD film formation on the metal substrates (W, Wo). For the metal substrates (W, Wo), the insulator substrate (SiO x ) is presumed to be able to selectively inhibit the ALD film formation, which is presumed to be because the film derived from the silylating agent (A) has a high molecular weight, similar to Example 1.

[0089] [Examples 26 - 32] Except for using the following silylating agents instead of bis(dimethylamino)dimethylsilane (BDMADMS) as the silylating agent (A), surface-treated substrates were obtained in the same manner as in Example 12. The silylating agents used are shown in Table 5. [Chemical formula]

[0090] [Comparative Examples 7 - 13] Except for not performing baking, surface-treated substrates were obtained in the same manner as in Examples 26 - 32.

[0091] [Comparative Example 14] Except for not using a surface treatment agent, the substrate treated in the same manner as in Examples 26 - 32 was used as the substrate of Comparative Example 12.

[0092] [Comparative Example 15] Except for not performing baking, surface-treated substrates were obtained in the same manner as in Comparative Example 14.

[0093] For the surface-treated substrates obtained in Examples 26 - 32 and Comparative Examples 7 - 15, <Measurement of the contact angle of water> was performed in the same manner as in Example 2. The results are shown in Table 5. In any case, the metal substrates (W, Wo) were not made water-repellent.

[0094] [Table 5]

[0095] As is clear from the results shown in Table 5 above, even if the silylating agent is changed, as long as it is an organomono-silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom, similar to Example 2, the insulator substrate (SiO x ) is hydrophobized, but the metal substrates (W, Wo) are not hydrophobized, and it can be said that the insulator substrate (SiO x ) can be selectively hydrophobized with respect to the metal substrates (W, Wo). It can also be seen that baking is extremely effective for good hydrophobization. Also, even if the silylating agent is changed, as long as it is an organomono-silane in which 2 to 4 nitrogen atoms are bonded to a silicon atom, similar to Example 2, in the ALD film formation test, the ALD film formation on the insulator substrate (SiO x ) is significantly inhibited, while the ALD film formation on the metal substrates (W, Wo) is not inhibited, and it is presumed that the ALD film formation on the insulator substrate (SiO x ) can be selectively inhibited with respect to the metal substrates (W, Wo). This is presumed to be because, similar to Example 1, the film derived from the silylating agent (A) has a high molecular weight.

[0096] [Comparative Examples 16 to 18] Except that the following polydimethylsiloxanes P1 to P3 were used instead of bisdimethylaminodimethylsilane (BDMADMS), surface-treated substrates were obtained in the same manner as in Example 2. The polydimethylsiloxanes (polymers) used are shown in Table 6. The mass average molecular weight of the polydimethylsiloxane is the mass average molecular weight in terms of polystyrene by GPC (gel permeation chromatography). [Chemical formula] P1: Polydimethylsiloxane with a mass average molecular weight of 117,000 P2: Polydimethylsiloxane with a mass average molecular weight of 2,000 P3: Polydimethylsiloxane with a mass average molecular weight of 237

[0097] For the surface-treated substrates obtained in Comparative Examples 16 to 18, <Measurement of water contact angle> and <ALD film formation test of Al2O3> were carried out in the same manner as in Example 2. The results are shown in Table 6.

[0098]

Table 6

[0099] As is clear from the results shown in Table 6 above, when using polysiloxane instead of organomono-silane in which 2 to 4 nitrogen atoms are bonded to silicon atoms, the difference in water repellency between the insulator substrate (SiO x ) and the metal substrates (W, Wo) is small, and it cannot be said that selective water repellency has been achieved. Also, when using polysiloxane instead of organomono-silane in which 2 to 4 nitrogen atoms are bonded to silicon atoms, the difference in the inhibitory effect on ALD film formation for the insulator substrate (SiO x ) and the metal substrates (W, Wo) is small, and it cannot be said that ALD film formation has been selectively inhibited.

[0100] [Example 33] (Surface treatment) Using the surface treatment agent of Example 2, the surfaces of a silicon thermal oxide film substrate (SiOx), a tungsten substrate (W), and a molybdenum substrate (Mo) were treated according to the following method. Specifically, each substrate was immersed in an HF aqueous solution with a concentration of 0.5% by mass at room temperature (25°C) for 1 minute for pretreatment. After the above pretreatment, the substrate was washed with ion-exchanged distilled water for 1 minute. The washed substrate was dried by a nitrogen stream. Each dried substrate was immersed (exposed) in the surface treatment agent at room temperature for 1 minute, then the substrate was taken out and dried by a nitrogen stream. Next, the substrate dried by a nitrogen stream was put into a heating furnace and heated (baked) at 150°C for 30 minutes. Then, the baked substrate was washed (rinsed) by immersing it in isopropanol and stirring for 1 minute, and then rinsed with ion-exchanged distilled water for 1 minute. The washing was performed at room temperature. Note that no washing by rinsing with a liquid was performed between the application (exposure) of the surface treatment agent to the substrate and baking. The washed substrate was dried by a nitrogen stream to obtain a surface-treated substrate.

[0101] [Comparative Example 19] A surface-treated substrate was obtained in the same manner as in Example 33, except that baking was not performed.

[0102] [Comparative Example 20] (Preparation of surface treatment agent) 10% by mass of bisdimethylaminodimethylsilane (BDMADMS), which is a silylating agent (A), and 7% by mass of imidazole, which is a nitrogen-containing heterocyclic compound (B), were uniformly mixed in the solvent propylene glycol monomethyl ether acetate (S1) to prepare a surface treatment agent for Comparative Example 20.

[0103] (Surface treatment) A surface-treated substrate was obtained in the same manner as in Example 33, except that the surface treatment agent of Comparative Example 20 was used instead of the surface treatment agent of Example 2.

[0104] [Comparative Example 21] A surface-treated substrate was obtained in the same manner as in Comparative Example 20, except that baking was not performed.

[0105] [Comparative Example 22] For the same silicon thermal oxide film substrate (SiOx) as used in Example 33, after pretreatment by immersing it in an aqueous HF solution with a concentration of 0.5% by mass at room temperature (25°C) for 1 minute, washing it with ion-exchanged distilled water for 1 minute, and drying it with a nitrogen stream, the substrate was used as the substrate for Comparative Example 22.

[0106] For the surface-treated substrates obtained in Example 33 and Comparative Examples 19 to 22, <Measurement of water contact angle> and <ALD film formation test of Al2O3> were performed in the same manner as in Example 2. The results are shown in Table 7. In addition, in any of the examples, the metal substrates (W, Wo) were not made water-repellent, and the ALD film formation of Al2O3 was not inhibited.

[0107]

Table 7

[0108] As is clear from the results shown in Table 7 above, Example 33 in which the surface treatment agent does not contain a nitrogen-containing heterocyclic compound and baking is performed in the surface treatment, is the same as Comparative Example 19 in which the surface treatment agent does not contain a nitrogen-containing heterocyclic compound and baking is not performed in the surface treatment, Comparative Example 20 in which the surface treatment agent contains a nitrogen-containing heterocyclic compound and baking is performed in the surface treatment, and Comparative Example 21 in which the surface treatment agent contains a nitrogen-containing heterocyclic compound and baking is not performed in the surface treatment. The insulator substrate (SiO x ) is hydrophobized, but the metal substrates (W, Wo) are not hydrophobized, and the difference in the water contact angle between the insulator substrate (SiO x ) and the metal substrates (W, Wo) is large. Incidentally, the degree of hydrophobization (water contact angle) of the insulator substrate (SiO x ) in Example 33 and Comparative Examples 19 to 21 was of the same degree. On the other hand, in the ALD film formation test, it can be said that Example 33 can selectively inhibit the ALD film formation on the insulator substrate (SiO x ) with respect to the metal substrates (W, Wo) more than Comparative Examples 19 to 21 in which the hydrophobization is of the same degree as in Example 33. This is presumably because in Example 33, as in Example 1, the film derived from the silylating agent (A) has a high molecular weight.

[0109] Also, as is clear from the results shown in Table 7 above, when baking is not performed, the hydrophobization of the insulator substrate (SiO x ) and the inhibitory property of the ALD film formation on the insulator substrate (SiO x ) are improved by the surface treatment agent containing a nitrogen-containing heterocyclic compound. However, when baking is performed, it can be said that the inhibitory property of the ALD film formation on the insulator substrate (SiO x ) is reduced by the surface treatment agent containing a nitrogen-containing heterocyclic compound.

[0110] Also, as is clear from the results shown in Table 7 above, it can be said that the inhibitory property of the ALD film formation on the insulator substrate (SiO x ) due to baking is improved when the surface treatment agent does not contain a nitrogen-containing heterocyclic compound rather than when the surface treatment agent contains a nitrogen-containing heterocyclic compound.

Claims

1. A substrate preparation step of preparing a substrate having two or more regions with different surface materials; An exposure step of exposing the surface of the substrate to a surface treatment agent; A baking step of baking the substrate after the exposure step, including: Between the exposure step and the baking step, not including a rinsing step of rinsing the surface of the substrate with a liquid; The surface treatment agent includes a silylating agent (A) and does not include a nitrogen-containing heterocyclic compound (B); The silylating agent (A) includes an organomono-silane; In the organomono-silane, two or more and four or less nitrogen atoms are bonded to the silicon atom; A substrate surface treatment method.

2. The substrate surface treatment method according to Claim 1, wherein the two or more regions include at least one insulator region and at least one metal region.

3. The insulator is selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, hafnium oxide, tantalum oxide, fluorine-containing silicon oxide, carbon-containing silicon oxide, silicon nitride, boron nitride, silicon carbide, silicon carbonitride, silicon oxynitride, silicon oxycarbonitride, silicon, and silicon doped with one or more selected from phosphorus, boron, and germanium; The metal is selected from the group consisting of tungsten, chromium, molybdenum, copper, cobalt, aluminum, silver, nickel, titanium, gold, ruthenium, titanium nitride, and tantalum nitride. The substrate surface treatment method according to Claim 2.

4. The substrate surface treatment method according to any one of Claims 1 to 3, wherein the organomono-silane includes a compound represented by the following formula (1). 【Chemical Formula 1】 (In formula (1), R １ and R ２ each independently represent a hydrogen atom, a nitrogen-containing group, or an organic group, and the total number of carbon atoms contained in R １ and R ２ is 1 or more.) R ３ ~R ６ each independently represents a hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, an acetyl group, or a saturated or unsaturated heterocycloalkyl group.)

5. In the exposure step, the surface treatment agent is applied to the surface of the substrate by a spin coating method. The substrate surface treatment method according to any one of Claims 1 to 4.

6. A surface treatment step of treating the surface of the substrate by the substrate surface treatment method according to any one of Claims 1 to 5; A film forming step of forming a film on the surface of the substrate after the surface treatment step by an atomic layer growth method, including: A method for selectively forming a film on a region of a substrate surface, in which the deposition amount of the film material is made different regionally.

7. A surface treatment agent used in the substrate surface treatment method according to any one of Claims 1 to 5, including: A silylating agent (A) and does not include a nitrogen-containing heterocyclic compound (B); The silylating agent (A) includes an organomono-silane. A surface treatment agent in which 2 to 4 nitrogen atoms are bonded to a silicon atom in the organomono-silane.

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