JP7378293B2 - Surface treatment agent, surface treatment method, and region-selective film formation method on substrate surface - Google Patents

Description

The present invention relates to a surface treatment agent, a surface treatment method, and a region-selective film forming method on a substrate surface.

In recent years, there has been an increasing trend toward higher integration and miniaturization of semiconductor devices, and organic patterns that serve as masks and inorganic patterns created by etching are becoming increasingly finer, creating a need for film thickness control at the atomic layer level. .
Atomic layer deposition (ALD) (hereinafter also simply referred to as "ALD") is known as a method for forming a thin film on a substrate at the atomic layer level. It is known that the ALD method has both higher step coverage and film thickness controllability than the general CVD (Chemical Vapor Deposition) method.

In the ALD method, two types of gases whose main components are the elements constituting the film to be formed are alternately supplied onto the substrate, and a thin film is formed on the substrate in atomic layer units, which is repeated multiple times to form the desired film. This is a thin film formation technology that forms thick films.
In the ALD method, only one or several layers of raw material gas components are adsorbed onto the substrate surface while the raw material gas is being supplied, and the excess raw material gas does not contribute to growth. ).
For example, when forming an A1 ₂ O ₃ film on a substrate, a source gas made of TMA (TriMethy1 Aluminum) and an oxidizing gas containing O are used. Furthermore, when forming a nitride film on a substrate, nitriding gas is used instead of oxidizing gas.

In recent years, attempts have been made to form a film selectively on a substrate surface using the ALD method (see Non-Patent Documents 1 and 2).
Along with this, there has been a demand for a substrate whose surface has been modified in a region-selective manner so that it can be suitably applied to a region-selective film formation method on a substrate using the ALD method.
As a film forming method, by using the ALD method, it is expected that film thickness control at the atomic layer level, step coverage, and miniaturization of patterning can be achieved.

J. Phys. Chem. C 2014, 118, 10957-10962 ACS NANO Vol. 9, No. 9, 8710-8717 (2015)

ALD methods often include treatment steps under high-temperature conditions and chemical treatment steps, and the materials used are required to have heat resistance and chemical resistance. Furthermore, when the film-forming material is hydrophilic, the material used is required to have water repellency.
In addition, in the method of region-selectively forming a film on the substrate surface using the ALD method as described in Non-Patent Documents 1 and 2, if at least one region contains metal, the material used is metal-corrosive. It is desirable that the

The present invention has been made in view of the above circumstances, and provides a method for treating a surface including two or more regions in which adjacent regions of the two or more regions have different materials from each other. A surface treatment agent with good properties such as heat resistance, chemical resistance, water repellency, and metal corrosion resistance, a surface treatment method using the surface treatment agent, and region-selective film formation on a substrate surface using the surface treatment method The task is to provide a method.

In order to solve the above problems, the present invention employs the following configuration.

A first aspect of the present invention is a surface including two or more regions in which at least one region contains a metal surface, and the surfaces of adjacent regions of the two or more regions are treated with different materials. This is a surface treatment agent used for the purpose of the present invention, which contains a compound (P) represented by the following general formula (P-1).

［式中、Ｒ^１は直鎖状又は分岐鎖状のフッ素化アルキル基である。Ｒ^２及びＲ^３はそれぞれ独立に水素原子、直鎖若しくは分岐鎖状のアルキル基、直鎖若しくは分岐鎖状のフッ素化アルキル基、又は置換基を有してもよい芳香族炭化水素基である。］

[In the formula, R ¹ is a linear or branched fluorinated alkyl group. R ² and R ³ are each independently a hydrogen atom, a linear or branched alkyl group, a linear or branched fluorinated alkyl group, or an aromatic hydrocarbon group which may have a substituent. . ]

A second aspect of the present invention is a surface treatment method for a surface of a substrate, the method comprising exposing the surface to the surface treatment agent according to the first aspect, wherein the surface has two or more regions. at least one region of the two or more regions contains a metal surface, adjacent regions of the two or more regions have different materials, and the compound (P) and the two or more regions This is a surface treatment method in which the contact angles of adjacent regions of the two or more regions are made to differ from each other by the reaction of

A third aspect of the present invention includes treating the surface of the substrate by the surface treatment method according to the second aspect, and forming a film on the surface of the surface-treated substrate by atomic layer growth. A method for selectively forming a film on the surface of the substrate, the method comprising: selectively varying the amount of deposited material of the film on the surface of the substrate.

According to the present invention, in a method of treating a surface including two or more regions in which adjacent regions of the two or more regions are made of different materials, heat resistance, chemical resistance, and water repellency are provided. It is possible to provide a surface treatment agent having good properties such as metal corrosivity, a surface treatment method using the surface treatment agent, and a region-selective film forming method on a substrate surface using the surface treatment method.

<First aspect: Surface treatment agent>
The surface treatment agent according to the first aspect of the present invention has a surface including two or more regions in which at least one region contains a metal surface, and the two or more regions that are adjacent to each other have different materials. This is a surface treatment agent used to treat surfaces with different surfaces (hereinafter sometimes simply referred to as "surface to be treated").

The surface to be treated to which the surface treatment agent of the present embodiment is applied includes two or more regions in which at least one region contains a metal surface, and adjacent regions of the two or more regions have different materials.

In the present embodiment, when the surface to be treated includes two regions, the surface to be treated includes a first region containing a metal surface and a material different from the first region and adjacent to the first region. and a second area. In such a case, the "adjacent areas" are the first area and the second area.
Here, the first region and the second region each may or may not be divided into a plurality of regions.

In this embodiment, when the surface to be treated includes three or more regions, the surface to be treated includes a first region containing a metal surface and a material that is different from the first region, and the first region contains a metal surface. The second region is adjacent to the second region, and the second region is made of different materials, and includes a third region adjacent to the second region. In such a case, the "adjacent areas" may be the first area and the second area (i.e., adjacent areas), or the first area and the third area (i.e., the next adjacent area). There may be.
Note that if the materials of the first region and the third region are not different (that is, if the first region and the third region both contain metal surfaces), the "adjacent region" is the first region. and the second region, or the second region and the third region (that is, adjacent regions).
Here, each of the first region, second region, and third region may or may not be divided into a plurality of regions.
In this embodiment, the same concept can be applied to the case where the surface to be treated includes a fourth or more region.
The upper limit of the number of regions with different materials is not particularly limited as long as the effects of the present invention are not impaired, but is, for example, 7 or less, or 6 or less, and typically 5 or less.

In this embodiment, the metal surface included in the surface to be treated is not particularly limited, but it is preferably a metal surface containing copper and/or cobalt.

The surface treatment agent of this embodiment contains a compound (P) represented by the following general formula (P-1).

［式中、Ｒ^１は直鎖状又は分岐鎖状のフッ素化アルキル基である。Ｒ^２及びＲ^３はそれぞれ独立に水素原子、直鎖若しくは分岐鎖状のアルキル基、直鎖若しくは分岐鎖状のフッ素化アルキル基、又は置換基を有してもよい芳香族炭化水素基である。］

[In the formula, R ¹ is a linear or branched fluorinated alkyl group. R ² and R ³ are each independently a hydrogen atom, a linear or branched alkyl group, a linear or branched fluorinated alkyl group, or an aromatic hydrocarbon group which may have a substituent. . ]

・Compound (P)
Compound (P) is a phosphonic acid represented by the general formula (P-1) or a derivative thereof.
In the general formula (P-1), the straight chain or branched fluorinated alkyl group in R ¹ is a straight chain or branched alkyl group in which some or all of the hydrogen atoms are substituted with fluorine atoms. It is the basis.
The linear or branched alkyl group preferably has 5 to 45 carbon atoms, more preferably 6 to 40 carbon atoms, even more preferably 7 to 35 carbon atoms, and particularly preferably 8 to 30 carbon atoms.
Straight chain alkyl groups include pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexa Examples include decyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group, and isomers of the above alkyl groups.

Among them, R ¹ has the general formula: R ¹¹ -R ¹² - ^* (wherein R ¹¹ is a fluorinated alkyl group, R ¹² is an alkylene group, and * is a bond with a phosphorus atom (P) A group represented by (indicates a hand) is preferable.
Examples of R ¹¹ include the same linear or branched fluorinated alkyl groups as R ¹ above. Among these, R ¹¹ is preferably a straight chain or branched fluorinated alkyl group having 1 to 40 carbon atoms, more preferably a straight chain or branched fluorinated alkyl group having 3 to 20 carbon atoms. Even more preferred are straight-chain or branched perfluoroalkyl groups having a number of 6 to 20.
The alkylene group in R ¹² preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 5 carbon atoms.

In the general formula (P-1), the linear or branched alkyl group in R ² and R ³ is the linear or branched alkyl group constituting the linear or branched fluorinated alkyl group in R ¹ . Examples include those similar to chain alkyl groups.
The linear or branched fluorinated alkyl group in R ² and R ³ is the same as the linear or branched fluorinated alkyl group in R ¹ above.
Examples of the aromatic hydrocarbon group which may have a substituent in R ² and R ³ include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, and a p-adamantylphenyl group. , tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, and the like.
Among these, hydrogen atoms are preferred as R ² and R ³ .

In this embodiment, one type of compound (P) may be used alone, or two or more types may be used.
In the surface treatment agent according to the present embodiment, the content of compound (P) is preferably 0.0001 to 5% by mass, more preferably 0.001 to 4% by mass, and 0.0001 to 5% by mass, more preferably 0.001 to 4% by mass, based on the total mass of the surface treatment agent. The amount is more preferably .005 to 3% by weight, and even more preferably 0.008 to 3% by weight.
By setting the content of the compound (P) within the above-mentioned preferred range, a surface including two or more regions, in which adjacent regions of the two or more regions have different materials, is treated. In the method, when at least one region contains a metal surface, the compound (P) is likely to be adsorbed to the region containing the metal surface, and the selectivity of the surface treatment agent to the region containing the metal surface is likely to be improved. . In addition, various properties (heat resistance, chemical resistance, Water repellency, metal corrosion resistance, surface free energy, etc.) tend to be good.

- Water The surface treatment agent according to the present embodiment may contain water in order to further improve water repellency. The water may contain unavoidably mixed trace components. The water used in the surface treatment agent of this embodiment is preferably purified water such as distilled water, ion-exchanged water, or ultrapure water, and ultrapure water commonly used in semiconductor manufacturing is used. It is more preferable.
In the surface treatment agent according to the present embodiment, the water content is preferably 1 to 25% by mass, more preferably 3 to 20% by mass, and even more preferably 5 to 15% by mass.
In a method for treating a surface including two or more regions in which adjacent regions of the two or more regions have different materials, the water content is within the above-mentioned preferred range, When at least one region contains a metal surface, the compound (P) is likely to be adsorbed to the region containing the metal surface, and the selectivity of the surface treatment agent to the region containing the metal surface is likely to be improved. Moreover, the water repellency of the surface treatment agent is more likely to be improved.

-Solvent In the surface treatment agent of this embodiment, each component is preferably dissolved in a solvent. When the surface treatment agent contains a solvent, surface treatment of the substrate by a dipping method, a spin coating method, or the like tends to be easy.

Specific examples of solvents include sulfoxides such as dimethylsulfoxide; sulfones such as dimethylsulfone, diethylsulfone, bis(2-hydroxyethyl)sulfone, and tetramethylenesulfone; N,N-dimethylformamide, N-methylformamide, and , N-dimethylacetamide, N-methylacetamide, N,N-diethylacetamide and other amides; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-hydroxymethyl Lactams such as -2-pyrrolidone and N-hydroxyethyl-2-pyrrolidone; 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-diisopropyl-2- Imidazolidinones such as imidazolidinone; dialkyl glycol ethers such as dimethyl glycol, dimethyl diglycol, dimethyl triglycol, methyl ethyl diglycol, diethyl glycol, triethylene glycol butyl methyl ether; 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-vundecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3, Monoalcoholic solvents such as 3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, and cresol; 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 - (Poly)alkylene glycol monoalkyl ethers such as butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether; 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, and other (poly)alkylene glycol monoalkyl ether acetates; 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 diethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran and other ethers; methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone and other ketones; 2- Lactic acid alkyl esters such as methyl 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-methylbutanoate, 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-octoate, methyl decanoate, methyl pyruvate, pyruvin Other esters such as ethyl acid, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl 2-oxobutanoate, dimethyl adipate, propylene glycol diacetate; propyrolactone, γ-butyrolactone, 6-pentylolactone Lactones such as lactone; n-hexane, n-heptane, n-octane, n-nonane, methyloctane, n-decane, n-vundecane, n-dodecane, 2,2,4,6,6-pentamethyl Linear, branched, or cyclic aliphatic hydrocarbons such as heptane, 2,2,4,4,6,8,8-heptamethylnonane, cyclohexane, methylcyclohexane; benzene, toluene, xylene, 1 , 3,5-trimethylbenzene, naphthalene, and other aromatic hydrocarbons; p-menthane, diphenylmenthane, limonene, terpinene, bornane, norbornane, pinane, and other terpenes; and the like.

Among these, 3-methyl-3-methoxy-1-butyl acetate, ethyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, isopropanol or methyl ethyl ketone are preferable, and propylene glycol monomethyl ether is more preferable. preferable.

The surface treatment agent according to the present embodiment has a surface free energy (hereinafter sometimes simply referred to as "SFE") of the copper substrate after the copper substrate is immersed at 25° C. for 1 minute of 40 mJ/m ² It is preferably at most 30 mJ/m ² , more preferably at most 20 mJ/m 2 , even more preferably at most 20 mJ/m ² .
In a method for treating a surface including two or more regions, in which adjacent regions of the two or more regions have different materials, at least one When one region contains a metal surface, the compound (P) is likely to be adsorbed to the region containing the metal surface, and the selectivity of the surface treatment agent to the region containing the metal surface is likely to be improved.
Note that the surface free energy (SFE) of the substrate surface can be measured by the Owens-Wendt method according to the procedure described in the Examples section.

The surface treatment agent according to the present embodiment has a contact angle (hereinafter referred to as "CA _bake ") of the surface of the cobalt substrate after the cobalt substrate is immersed at 25° C. for 1 minute and then baked at 300° C. in a nitrogen atmosphere. ) is preferably 75° or more, more preferably 80° or more, and even more preferably 85° or more.
By setting the CA _bake within the above-mentioned preferable range, in a method for treating a surface including two or more regions in which adjacent regions of the two or more regions are made of different materials, the high temperature It becomes easier to form a film stably even under various conditions.

The surface treatment agent according to the present embodiment has a contact angle (CA w/o ) of the copper substrate after the copper substrate is immersed at 60° for 18 hours, and a contact angle (CA _w/o ) of the copper substrate after the copper substrate is immersed at 60° for 18 hours, and then The difference from the contact angle (CA _w ) of the copper substrate after immersion in 1.0% hydrochloric acid at 25°C for 1 minute (hereinafter sometimes referred to as "CA _chem ") is within ±40°. is preferable, more preferably within ±35°, and still more preferably within ±30°.
By setting the CA _chem within the above-mentioned preferable range, in a method for treating a surface including two or more regions in which adjacent regions of the two or more regions have different materials, the chemical Chemical resistance tends to be good, making it easier to form a film stably.

The surface treatment agent of this embodiment contains a compound (P) represented by general formula (P-1). Compound (P) is a phosphonic acid or a derivative thereof, and has a linear or branched fluorinated alkyl group as at least R ¹ . A linear or branched fluorinated alkyl group has a C--F bond that has a higher bond energy than an alkyl chain (C--H bond). Furthermore, when a linear or branched fluorinated alkyl group contains a plurality of fluorine atoms, it becomes a skeleton that is more rigid than an alkyl chain due to repulsion between fluorine atoms. In combination with the above configuration, the surface treatment agent of the present embodiment is used in a method of treating a surface including two or more regions, in which adjacent regions of the two or more regions have different materials from each other. It is assumed that properties such as heat resistance, chemical resistance, water repellency, and metal corrosion resistance will be improved.
In addition, the surface treatment agent according to the present embodiment has high selectivity particularly to a region including a metal surface, and therefore can be particularly suitably applied to region-selective film formation on a substrate surface using an ALD method.

A surface treatment method according to a second aspect of the present invention is a method for treating a surface of a substrate, and includes exposing the surface to the surface treatment agent according to the first aspect.
In the surface treatment method according to the present embodiment, the surface includes two or more regions, at least one region of the two or more regions contains a metal surface, and adjacent regions of the two or more regions The materials are different from each other, and due to the reaction between the compound (P) and the two or more regions, the contact angles of adjacent regions of the two or more regions are made to differ from each other.

In this embodiment, the "substrate" to be subjected to surface treatment is exemplified by a substrate used for manufacturing a semiconductor device, such as a silicon (Si) substrate, a silicon nitride (SiN) substrate, a silicon oxide film ( Ox) substrate, tungsten (W) substrate, cobalt (Co) substrate, titanium nitride (TiN) substrate, tantalum nitride (TaN) substrate, germanium (Ge) substrate, silicon germanium (SiGe) substrate, aluminum (Al) substrate, nickel (Ni) substrate, ruthenium (Ru) substrate, copper (Cu) substrate, etc.
The "surface of the substrate" includes the surface of the substrate itself, the surface of an inorganic pattern and an organic pattern provided on the substrate, and the surface of an unpatterned inorganic layer or organic layer.

An example of the inorganic pattern provided on the substrate is a pattern formed by etching and creating a mask on the surface of an inorganic layer existing on the substrate by a photoresist method, and then performing an etching process. Inorganic layers include, in addition to the substrate itself, oxide films of elements constituting the substrate, SiN, Ox, W, Co, TiN, TaN, Ge, SiGe, Al, Al ₂ O ₃ , Ni, formed on the surface of the substrate. Examples include films or layers of inorganic substances such as Ru and Cu.
Examples of such films and layers include, but are not particularly limited to, inorganic films and layers formed during the manufacturing process of semiconductor devices.

Examples of the organic pattern provided on the substrate include a resin pattern formed on the substrate by photolithography using a photoresist or the like. Such an organic pattern can be formed, for example, by forming an organic layer, which is a photoresist film, on a substrate, exposing the organic layer to light through a photomask, and developing the organic layer. The organic layer may be an organic layer 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 an organic layer is not particularly limited, but can be exemplified by an organic film provided for etching and forming a mask in the process of manufacturing a semiconductor device.

(A mode in which the substrate surface includes two regions)
In the surface treatment method according to the second aspect, the substrate surface includes two or more regions, at least one region of the two or more regions contains a metal surface, and adjacent regions of the two or more regions However, the materials are different from each other.

Among the above two or more regions, the regions where the water contact angle tends to be higher (preferably, the surface free energy is smaller) than the other region include W, Co, Al, Al ₂ O ₃ , Ni , Ru, Cu, TiN, and TaN.
Among the above two or more regions, the regions where the water contact angle tends to be smaller (preferably, the surface free energy is higher) than the other region include Si, Al ₂ O ₃ , SiN, Ox, and TiN. , TaN, Ge, and SiGe.

In the present embodiment, when the substrate surface includes two regions, the substrate surface includes a first region containing a metal surface and a second region that is made of a different material from the first region and that is adjacent to the first region. including the area of In such a case, the "adjacent areas" are the first area and the second area.
Here, the first region and the second region each may or may not be divided into a plurality of regions.

Examples of the first region and the second region include a mode in which the surface of the substrate itself is the first region and a surface of an inorganic layer formed on the surface of the substrate is the second region; Examples include an embodiment in which the surface of the first inorganic layer formed is the first region, and the surface of the second inorganic layer formed on the surface of the substrate is the second region. Note that embodiments in which an organic layer is formed instead of the inorganic layer may also be mentioned.

In an embodiment in which the surface of the substrate itself is the first region and the surface of the inorganic layer formed on the surface of the substrate is the second region, selective hydrophobicity is created between two or more adjacent regions made of different materials on the substrate surface. The surface of at least one substrate selected from the group consisting of a Si substrate, a SiN substrate, an Ox substrate, a TiN substrate, a TaN substrate, a Ge substrate, and a SiGe substrate. is defined as a first region, and the surface of an inorganic layer formed on the surface of the substrate and containing at least one selected from the group consisting of W, Co, A1, Ni, Ru, Cu, TiN, and TaN is defined as a second region. A preferred embodiment is a region.

Further, as an embodiment 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 material on the surface of the substrate is From the viewpoint of selectively improving hydrophobicity and improving the difference in water contact angle between two or more different adjacent regions, SiN, Ox, TiN, W, Co, Al, Ni, Ru, Cu formed on the surface of the substrate, with the surface of the first inorganic layer containing at least one selected from the group consisting of TaN, Ge, and SiGe as the first region. It is preferable that the surface of the second inorganic layer containing at least one selected from the group consisting of , TiN, and TaN is used as the second region.

(A mode in which the substrate surface includes three or more areas)
In this embodiment, when the substrate surface includes three or more regions, the substrate surface includes a first region containing a metal surface, which is made of a different material from the first region, and which is adjacent to the first region. The second region is made of different materials and includes a third region adjacent to the second region. In such a case, the "adjacent areas" may be the first area and the second area (i.e., adjacent areas), or the first area and the third area (i.e., the next adjacent area). There may be.
Note that if the materials of the first region and the third region are not different (that is, if the first region and the third region both contain metal surfaces), the "adjacent region" is the first region. and the second region, or the second region and the third region (that is, adjacent regions).
Here, each of the first region, second region, and third region may or may not be divided into a plurality of regions.
As an example of the first region, second region, and third region, for example, the surface of the substrate itself is the first region, and the surface of the first inorganic layer formed on the surface of the substrate is the second region. Examples include an embodiment in which the surface of the second inorganic layer formed on the surface of the substrate is the third region. Note that embodiments in which an organic layer is formed instead of the inorganic layer may also be mentioned. Further, embodiments including both an inorganic layer and an organic layer, such as one in which only one of the second inorganic layer and the third inorganic layer is replaced with an organic layer, can also be mentioned.
From the viewpoint of selectively improving hydrophobicity and improving the difference in water contact angle between two or more adjacent regions made of different materials on the substrate surface, the surface of an arbitrary substrate (for example, a Si substrate) itself is The surface of the first inorganic layer formed on the surface of the substrate and containing at least one selected from the group consisting of SiN, Ox, TiN, TaN, Ge and SiGe is defined as the second region, and the surface of the first inorganic layer formed on the surface of the substrate is defined as the second region. It is preferable that the surface of the second inorganic layer containing at least one selected from the group consisting of W, Co, Al, Ni, Ru, Cu, TiN and TaN is formed on the surface of the third region. .
In this embodiment, the same concept can be applied to the case where the substrate surface includes the fourth or more regions.
The upper limit of the number of regions with different materials is not particularly limited as long as the effects of the present invention are not impaired, but is, for example, 7 or less, or 6 or less, and typically 5 or less.

(exposure)
As a method for exposing the surface of the substrate to a surface treatment agent, a surface treatment agent (typically a liquid surface treatment agent) that may contain a solvent may be exposed to the surface treatment agent, for example, by dipping, spin coating, roll coating, or the like. Examples include a method of applying (for example, coating) the surface of the substrate and exposing it by means such as a coating method such as a doctor blade method.
The exposure temperature is, for example, 10°C or more and 90°C or less, preferably 20°C or more and 80°C or less, more preferably 20°C or more and 70°C or less, and still more preferably 20°C or more and 30°C or less.
The exposure time is preferably 20 seconds or more, more preferably 30 seconds or more, and even more preferably 45 seconds or more, from the viewpoint of selectively improving hydrophobicity between two or more adjacent regions of different materials on the substrate surface.
The upper limit of the above exposure time is not particularly limited, but is, for example, 2 hours or less, typically 1 hour or less, preferably 15 minutes or less, more preferably 5 minutes or less, and 2 minutes or less. Particularly preferred.
After the above exposure, cleaning (for example, cleaning with water, activator rinse, etc.) and/or drying (cleaning with nitrogen blower, etc.) may be performed as necessary.
For example, when cleaning the surface of a substrate with an inorganic pattern or an organic pattern using a cleaning liquid, the cleaning liquid that has conventionally been used for cleaning inorganic or organic patterns can be used as is; for inorganic patterns, SPM (sulfuric acid・Hydrogen peroxide solution), APM (ammonia/hydrogen peroxide solution), etc., and for organic patterns, water, activator rinse, etc. can be mentioned.
Further, the dried treated substrate may be additionally subjected to heat treatment at 100° C. or higher and 300° C. or lower, if necessary.

By the above exposure, the compound (P) can be adsorbed selectively in accordance with the material of each region on the surface of the substrate.
The contact angle of the substrate surface to water after being exposed to the surface treatment agent can be, for example, 50° or more and 140° or less.
By controlling the material of the substrate surface, the type and amount of compound (P) and acid used, exposure conditions, etc., the contact angle with water can be set to 50° or more, preferably 55° or more, and 65° or more. is more preferable.
The upper limit of the contact angle is not particularly limited, but is, for example, 140° or less, typically 130° or less.

In the surface treatment method according to the present embodiment, since the materials are different between two or more adjacent regions on the substrate surface, it is possible to selectively improve hydrophobicity between the two or more adjacent regions by the exposure. , the contact angle of water can be made different from each other.
The difference in water contact angle between the two or more adjacent regions is not particularly limited as long as it does not impair the effects of the present invention, and may be, for example, 10° or more. From the viewpoint of improving hydrophobicity, the water contact angle difference is preferably 20° or more, more preferably 30° or more, and even more preferably 40° or more.
The upper limit of the contact angle difference is not particularly limited as long as it does not impair the effects of the present invention, and is, for example, 80° or less or 70° or less, typically 60° or less.

<Third aspect: Region selective film formation method on substrate>
Next, a method for region-selective film formation on a substrate using the surface treatment method according to the second aspect will be described.
In this aspect, the region-selective film forming method on the substrate includes treating the surface of the substrate by the surface treatment method according to the second aspect, and forming an atomic layer on the surface of the surface-treated substrate. The method includes forming a film by a growth method (ALD method), and selectively varying the amount of deposited material of the film.

As a result of the surface treatment by the method according to the second aspect, the contact angle (preferably surface free energy) of water between the two or more regions differs, and in this aspect, the two or more regions The amount of deposited material forming the film can be selectively varied between regions on the substrate surface.
Specifically, in the region where the contact angle of water between the two or more regions is larger than that of the other region (preferably, the surface free energy is smaller), the film forming material formed by the ALD method is applied. It becomes difficult to adsorb (preferably chemically adsorb) the film-forming material to the above-mentioned regions on the substrate surface, and a difference occurs in the amount of film-forming material deposited between the two or more regions, resulting in a selective deposition amount of the film-forming material on the region on the substrate. It is preferable that they are different.
Examples of the chemical adsorption include chemical adsorption with hydroxyl groups.

Among the above two or more regions, the regions where the water contact angle tends to be larger (preferably, the surface free energy is smaller) than the other region include W, Co, Al, Al ₂ O ₃ , Ni , Ru, Cu, TiN, and TaN.
Among the above two or more regions, the regions where the water contact angle tends to be smaller (preferably, the surface free energy is higher) than the other region include Si, Al ₂ O ₃ , SiN, Ox, and TiN. , TaN, Ge, and SiGe.

(Film formation by ALD method)
There are no particular restrictions on the method of forming a film using the ALD method, but it may be a method of forming a thin film by adsorption (preferably chemical adsorption) using at least two gas phase reactants (hereinafter simply referred to as "precursor gas"). preferable.
Specifically, a method 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, etc. may be mentioned.
(a) exposing the substrate surface-treated by the method according to the first aspect above to a pulse of a first precursor gas; and (b) following step (a) above, exposing the substrate to a pulse of a second precursor gas. exposure to pulses of

After the above step (a) and before the above step (b), a plasma treatment step, a step of removing or purging the first precursor gas and its reactants with a carrier gas, a second precursor gas, etc. are performed. It may or may not be included.
After the step (b), the process may or may not include a plasma treatment step, a step of removing or purging the second precursor gas and its reactant with a carrier gas, etc.
Examples of the carrier gas include inert gases such as nitrogen gas, argon gas, and helium gas.

Preferably, each pulse per cycle and each layer formed is self-limiting, and more preferably each layer formed is a monoatomic layer.
The thickness of the monoatomic 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. be able to.

Examples of the first precursor gas include organic metals, metal halides, metal oxidized halides, etc. Specifically, tantalum pentaethoxide, tetrakis(dimethylamino)titanium, pentakis(dimethylamino)tantalum, tetrakis (dimethylamino)zirconium, tetrakis(dimethylamino)hafnium, tetrakis(dimethylamino)silane, copperhexafluoroacetylacetonate vinyltrimethylsilane, Zn(C ₂ H ₅ ) ₂ , Zn(CH ₃ ) ₂ , TMA (trimethylaluminum) ), TaCl ₅ , WF ₆ , WOCl ₄ , CuCl, ZrCl ₄ , AlCl ₃ , TiCl ₄ , SiCl ₄ , HfCl ₄ and the like.

Examples of the second precursor gas include a precursor gas that can decompose the first precursor or a precursor gas that can remove the ligand of the first precursor, and specifically, H ₂ O, H _Examples include _{2O2 , O2O3} , _NH3 , _H2S , _H2Se , _PH3 , _AsH3 , _C2H4 , _{and Si2H6 .}

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

The exposure temperature in step (b) is not particularly limited, but includes temperatures that are substantially equal to or higher than the exposure temperature in step (a).
There are no particular restrictions on the film formed by the ALD method, but films containing pure elements (e.g., Si, Cu, Ta, W), films containing oxides (e.g., SiO ₂ , GeO ₂ , HfO ₂ , ZrO ₂ , _{Ta2O5 , TiO2} , _Al2O3 , ZnO, _SnO2 , _{Sb2O5 , B2O3} , _In2O3 , _{WO3 )} , _films containing nitrides ( _e.g. , _{Si3N 4} , TiN, AlN, BN, GaN, NbN), films containing carbides (e.g. SiC), films containing sulfides (e.g. CdS, ZnS, MnS, _WS2 , PbS), films containing selenide (e.g. , CdSe, ZnSe), a film containing phosphide (GaP, InP), a film containing arsenide (eg, GaAs, InAs), or a mixture thereof.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

[Examples 1-2, Comparative Example 1, Reference Example 1]
Each component shown in Table 1 was mixed to prepare a surface treatment agent for each example.

(surface treatment)
Using the obtained surface treatment agents of Examples 1 and 2 and Comparative Example 1, a Cu substrate was surface treated according to the following method.

- Pretreatment Each substrate was pretreated by immersing it in an HF aqueous solution with a concentration of 0.5% by mass at 25° C. for 1 minute. After the above pretreatment, the substrate was washed with ion exchange distilled water for 1 minute. After washing with water, the substrate was dried with a nitrogen stream.

-Surface Treatment Each dried substrate was immersed in the surface treatment agent of each example under the surface treatment conditions shown in Table 1 to perform surface treatment of the substrate. After the surface treatment, the substrate was washed with isopropanol for 1 minute, and then washed with ion-exchanged distilled water for 1 minute. The cleaned substrate was dried with a nitrogen stream to obtain a surface-treated substrate.

(Measurement of water contact angle)
The water contact angle was measured for the Cu substrate subjected to only the above pretreatment (Reference Example 1) and each substrate after the above surface treatment (Examples 1 to 2, Comparative Example 1).
To measure the contact angle of water, use Dropmaster 700 (manufactured by Kyowa Interface Science Co., Ltd.) to drop a pure water droplet (2.0 μL) onto the surface of the surface-treated substrate, and calculate the contact angle 2 seconds after dropping. It was measured. The results are shown in Table 1 below.

(Measurement of surface free energy)
The surface free energy (mJ/m ² ) of the Cu substrate subjected to only the above pretreatment (Reference Example 1) and each substrate after the above surface treatment (Examples 1 to 2, Comparative Example 1) was measured using a Dropmaster 700 (Kyowa Measurement was carried out using the following procedures (1) to (3) using an instrument (manufactured by Interface Science Co., Ltd.).
(1) A pure water droplet (2.0 μL) is dropped onto the surface of the surface-treated substrate, and the contact angle Cw is measured 2 seconds after dropping.
(2) A diiodomethane droplet (1.2 μL) is dropped onto the surface of the surface-treated substrate, and the contact angle Ci is measured 2 seconds after the droplet is dropped.
(3) Surface free energy (mJ/m ² ) is calculated from the contact angle Cw and the contact angle Ci using the Owens-Wendt method.
The results are shown in Table 1 below.

In Table 1, each abbreviation has the following meaning. The numerical value in [ ] is the compounding amount (mass %).
(P)-1: (heptadecafluorodecyl)phosphonic acid (P)-2: Octadecylphosphonic acid DIW: Deionized water PGME: Propylene glycol monomethyl ether IBA: Isobutyl alcohol

From the results shown in Table 1, the surface treatment agents of Examples 1 and 2 improved the contact angle of the Cu substrate and decreased the surface free energy of the Cu substrate, compared to the surface treatment agent of Comparative Example 1. I know that there is. Therefore, it can be said that the use of the surface treatment agents of Examples 1 and 2 is more suitable for region-selective film formation on the substrate surface using the ALD method.

[Example 3, Comparative Example 2, Reference Example 2]
Each component shown in Table 2 was mixed to prepare a surface treatment agent for each example.

(surface treatment)
Using the obtained surface treatment agents of Example 3 and Comparative Example 2, a Cu substrate and a Co substrate were surface treated in the same manner as Examples 1 to 2 and Comparative Example 1. The surface treatment conditions using the surface treatment agent were 25° C. and 1 minute.

(Measurement of water contact angle)
The contact angle of water was measured in the same manner as described above for each substrate subjected to only the above pretreatment (Reference Example 2) and each substrate after the above surface treatment (Example 3, Comparative Example 2). The results are shown in Table 2.

(Evaluation of heat resistance)
A Cu substrate subjected to only the above pretreatment (Reference Example 2) and each substrate after the above surface treatment (Example 3, Comparative Example 2) were baked at 300°C. The contact angle of water was measured for each substrate after baking in the same manner as described above. The results are shown in Table 2.

In Table 2, each abbreviation is the same as above. The numerical value in [ ] is the compounding amount (mass %).

From the results shown in Table 2, it can be seen that the surface treatment agent of Example 3 has a smaller change in the contact angle of the substrate before and after baking treatment than the surface treatment agent of Comparative Example 2. Therefore, it can be said that the use of the surface treatment agent of Example 3 improves heat resistance and can be suitably applied to region-selective film formation on the substrate surface using the ALD method.

[Example 4, Comparative Example 3]
Each component shown in Table 3 was mixed to prepare a surface treatment agent for each example.

(surface treatment)
Using the obtained surface treatment agents of Example 4 and Comparative Example 3, the surface treatment of a Cu substrate was carried out in the same manner as in Examples 1 to 2 and Comparative Example 1. The surface treatment conditions using the surface treatment agent were 60° C. for 18 hours.

(Measurement of water contact angle)
For each substrate (Example 4, Comparative Example 3) after the above surface treatment, the contact angle of water was measured in the same manner as described above. The results are shown in Table 3.

(Evaluation of chemical resistance)
Each substrate (Example 4, Comparative Example 3) after the above surface treatment was immersed in 1.0% hydrochloric acid at 25° C. for 1 minute. The contact angle of water for each substrate after the hydrochloric acid immersion treatment was measured in the same manner as described above. The results are shown in Table 3.

In Table 3, each abbreviation is the same as above. The numerical value in [ ] is the compounding amount (mass %).

From the results shown in Table 3, it can be seen that the surface treatment agent of Example 4 shows a smaller change in the contact angle of the substrate before and after the hydrochloric acid immersion treatment than the surface treatment agent of Comparative Example 3. Therefore, it can be said that the use of the surface treatment agent of Example 4 improves the resistance to chemical solutions, and can therefore be suitably applied to region-selective film formation on the substrate surface using the ALD method.

[Example 5, Comparative Example 4]
Each component shown in Table 4 was mixed to prepare a surface treatment agent for each example.

(surface treatment)
Using the obtained surface treatment agents of Example 5 and Comparative Example 4, a Cu substrate and a Co substrate were surface treated in the same manner as Examples 1 to 2 and Comparative Example 1. The surface treatment conditions using the surface treatment agent were 25° C. and 1 minute.

(Measurement of water contact angle)
For each substrate (Example 5, Comparative Example 4) after the above surface treatment, the contact angle of water was measured in the same manner as described above. The results are shown in Table 4.

(Evaluation of metal corrosivity)
Each substrate (Example 5, Comparative Example 4) after the above surface treatment was immersed at 25° C. for 15 minutes, and the amount of film loss (etching amount) was measured by sheet resistance. The sheet resistance was measured using a resistivity meter VR-250 (manufactured by Kokusai Electric Semiconductor Service Co., Ltd.). The results are shown in Table 4.

In Table 4, each abbreviation is the same as above. The numerical value in [ ] is the compounding amount (mass %).

From the results shown in Table 4, the surface treatment agent of Example 5 improves the contact angle of Cu substrate and Co substrate and suppresses etching loss compared to the surface treatment agent of Comparative Example 4. I understand. Therefore, it can be said that the use of the surface treatment agent of Example 5 can be more suitably applied to region-selective film formation on the substrate surface using the ALD method.

[Examples 6-7, Comparative Examples 5-6, Reference Example 3]
Each component shown in Table 5 was mixed to prepare a surface treatment agent for each example.

(surface treatment)
Using the obtained surface treatment agents of Examples 6 to 7 and Comparative Examples 5 to 6, the surfaces of Cu substrates, Co substrates, and Al ₂ O ₃ film substrates were treated in the same manner as in Examples 1 to 2 and Comparative Example 1. processed. The surface treatment conditions using the surface treatment agent were 25° C. and 1 minute.

(Measurement of water contact angle)
The contact angle of water was measured in the same manner as above for each substrate subjected to only the above pretreatment (Reference Example 3) and each substrate after the above surface treatment (Examples 6 to 7, Comparative Examples 5 to 6). . The results are shown in Table 5.

In Table 5, each abbreviation is the same as above. The numerical value in [ ] is the compounding amount (mass %).

From the results shown in Table 5, it can be seen that the surface treatment agents of Examples 6 and 7 improve the contact angle of each substrate compared to the surface treatment agents of Comparative Examples 5 and 6. Therefore, it can be said that the use of the surface treatment agents of Examples 6 and 7 is more suitable for region-selective film formation on the substrate surface using the ALD method.

[Examples 8 to 10, Comparative Example 7, Reference Example 4]
Each component shown in Table 6 was mixed to prepare a surface treatment agent for each example.

(surface treatment)
Using the surface treatment agents of Examples 8 to 10 and Comparative Example 7, the surfaces of Cu substrates and Co substrates were treated in the same manner as in Examples 1 to 2 and Comparative Example 1. The surface treatment conditions using the surface treatment agent were 25° C. and 1 minute.

(Measurement of water contact angle)
The contact angle of water was measured in the same manner as described above for each substrate subjected to only the above pretreatment (Reference Example 4) and each substrate after the above surface treatment (Examples 8 to 10, Comparative Example 7). The results are shown in Table 6.

In Table 6, each abbreviation is the same as above. The numerical value in [ ] is the compounding amount (mass %).

From the results shown in Table 6, it can be seen that the surface treatment agents of Examples 8 to 10 improve the contact angle of each substrate compared to the surface treatment agent of Comparative Example 7. Therefore, it can be said that the surface treatment agents of Examples 8 to 10 can be more preferably applied to region-selective film formation on the substrate surface using the ALD method.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other changes to the configuration are possible without departing from the spirit of the invention. The invention is not limited by the foregoing description, but only by the scope of the appended claims.

Claims (4)

At least one region is a surface including two or more regions containing a metal surface, and a surface treatment agent used for treating surfaces having different materials with respect to adjacent regions of the two or more regions. There it is,
the metal surface contains copper and/or cobalt;
A surface treatment agent containing a compound (P) represented by the following general formula (P-1).

[In the formula, R ¹ is a linear or branched fluorinated alkyl group. R ² and R ³ are each independently a hydrogen atom, a linear or branched alkyl group, a linear or branched fluorinated alkyl group, or an aromatic hydrocarbon group which may have a substituent. be. ] The surface treatment agent according to claim 1, wherein the content of the compound (P) is 0.0001 to 5% by mass based on the total mass of the surface treatment agent. A surface treatment method for a surface of a substrate, the method comprising:
exposing the surface to a surface treatment agent according to any one of claims 1 or 2,
the surface includes two or more regions,
at least one region of the two or more regions contains a metal surface;
the metal surface contains copper and/or cobalt;
Adjacent regions among the two or more regions have different materials,
A surface treatment method in which contact angles of adjacent regions of the two or more regions are made to differ from each other by reaction between the compound (P) and two or more of the regions. Treating the surface of the substrate by the surface treatment method according to claim 3;
forming a film on the surface of the surface-treated substrate by atomic layer deposition;
A method for selectively forming a film on the surface of the substrate, comprising region-selectively varying the amount of deposited material of the film.