JP2017063179A - Surface preparation agent and surface treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface preparation agent capable of effectively preventing pattern collapse of an inorganic pattern or a resin pattern provided on a substrate; and provide a surface treatment method using the above-described surface preparation agent; and provide a surface preparation agent which allows an advanced silylation treatment on a surface of a treated body; and provide a surface treatment method using the latter surface preparation agent.SOLUTION: There is provided a surface preparation agent which is used for a surface treatment of a treated body and contains a silylation treatment agent and a non-silicon-containing and a nitrogen-containing heterocyclic compound.SELECTED DRAWING: None

Description

  The present invention relates to a surface treatment agent and a surface treatment method, and more particularly to a surface treatment agent and a surface treatment method that can be suitably applied to the surface treatment of an object to be processed such as a substrate used in semiconductor integrated circuit manufacturing.

  In the manufacture of a semiconductor device or the like, a lithography technique is used before the substrate is subjected to processing such as etching. In this lithography technique, a photosensitive resin layer is provided on a substrate using a photosensitive resin composition, and then this is selectively irradiated with actinic radiation for exposure and development, and then the photosensitive resin layer is formed. By selectively dissolving and removing, a resin pattern is formed on the substrate. Then, an inorganic pattern is formed on the substrate by performing an etching process using this resin pattern as a mask.

  By the way, in recent years, the trend toward higher integration and miniaturization of semiconductor devices has been increasing, and the miniaturization and high aspect ratio of the inorganic pattern produced by the resin pattern or etching process used as a mask have been advanced. However, on the other hand, the problem of so-called pattern collapse has arisen. This pattern collapse occurs when a large number of resin patterns and inorganic patterns are formed in parallel on a substrate, so that adjacent patterns are close to each other, and in some cases, the pattern is broken or peeled off from the base. That is the phenomenon. When such a pattern collapse occurs, a desired product cannot be obtained, which leads to a decrease in product yield and reliability.

  This pattern collapse is known to occur due to the surface tension of the cleaning liquid when the cleaning liquid dries in the cleaning process after pattern formation. That is, when the cleaning liquid is removed during the drying process, stress based on the surface tension of the cleaning liquid acts between the patterns, resulting in pattern collapse.

  Thus, many attempts have been made to prevent pattern collapse by adding a substance that lowers the surface tension to the cleaning liquid. For example, a cleaning solution to which isopropyl alcohol has been added, a cleaning solution to which a fluorosurfactant has been added, and the like have been proposed (see, for example, Patent Documents 1 and 2).

  In addition to the pattern collapse, in order to improve the adhesion between the resin pattern serving as a mask and the surface of the substrate, and to prevent a partial loss of the resin pattern due to the chemical developer, a photosensitive resin layer is provided on the substrate. Prior to the formation, a hydrophobic treatment (silylation treatment) using hexamethyldisilazane (HMDS) is performed on the surface of the substrate (for example, see “Background of the Invention” in Patent Document 3). ).

JP-A-6-163391 JP-A-7-142349 Japanese National Patent Publication No. 11-511900

  However, the device of the cleaning liquid as described in Patent Documents 1 and 2 has a problem that the prevention of pattern collapse is insufficient. In addition, when silylation treatment is performed on the surface of an object to be processed such as a substrate by HMDS, it takes time for the silylation treatment or the silylation treatment on the surface of the object to be processed is not sufficient. Sometimes it was not possible.

  The present invention has been made in view of the above situation, a surface treatment agent capable of effectively preventing pattern collapse of an inorganic pattern or a resin pattern provided on a substrate, and such a surface treatment. It is an object to provide a surface treatment method using an agent. In addition, as another object, the present invention provides a surface treatment agent capable of highly performing silylation treatment on the surface of an object to be treated, and a surface treatment method using such a surface treatment agent. For the purpose.

  The inventors of the present invention have made extensive studies to solve the above problems. As a result, when a surface treatment is performed on the surface of the object to be treated using a surface treatment agent containing a silylating agent and a nitrogen-containing heterocyclic compound not containing silicon atoms, the surface of the object to be treated is highly hydrophobic. I found out that In particular, the surface of the inorganic pattern or the resin pattern provided on the substrate is treated with such a surface treatment agent to be hydrophobized, and the contact angle with respect to the cleaning liquid is increased, whereby the pattern collapse of the inorganic pattern or the resin pattern is performed. Has been found to be prevented, and the present invention has been completed. Specifically, the present invention provides the following.

  A first aspect of the present invention is a surface treatment agent used for surface treatment of an object to be treated, which includes a silylating agent and a nitrogen-containing heterocyclic compound not containing a silicon atom.

  The second aspect of the present invention is a surface treatment method for treating the surface of a substrate by exposing the surface of the object to be treated to the surface treatment agent according to the first aspect.

  ADVANTAGE OF THE INVENTION According to this invention, the surface treatment agent which can prevent effectively the pattern collapse of the inorganic pattern or resin pattern provided on the board | substrate, and the surface treatment method using such a surface treatment agent are provided. The Moreover, according to this invention, the surface treatment method which can perform the silylation process to the surface of a to-be-processed body highly, and the surface treatment method using such a surface treatment agent are provided.

<Surface treatment agent>
The surface treatment agent will be described. The surface treatment agent is used when silylating the surface of the object to be treated. The kind of to-be-processed object is not specifically limited. The substrate is preferably a “substrate”. Here, the “substrate” to be subjected to the silylation process is exemplified by a substrate used for manufacturing a semiconductor device, and the “surface of the substrate” is provided on the substrate in addition to the surface of the substrate itself. Examples of the surface of the inorganic pattern and the resin pattern, and the surface of the non-patterned inorganic layer and organic layer are exemplified.

  Examples of the inorganic pattern provided on the substrate include a pattern formed by preparing an etching mask on the surface of the inorganic layer present on the substrate by a photoresist method and then performing an etching process. Examples of the inorganic layer include an oxide film of an element constituting the substrate, an inorganic film or layer such as silicon nitride, titanium nitride, or tungsten formed on the surface of the substrate in addition to the substrate itself. Such a film or layer is not particularly limited, and examples thereof include an inorganic film and layer formed in the process of manufacturing a semiconductor device.

  Examples of the resin pattern provided on the substrate include a resin pattern formed on the substrate by a photoresist method. Such a resin pattern is formed, for example, by forming an organic layer that is a photoresist film on a substrate, exposing the organic layer through a photomask, and developing the organic layer. As an organic layer, what was provided in the surface of the laminated film etc. which were provided in the surface of the board | substrate other than the surface of board | substrate itself is illustrated. Such an organic layer is not particularly limited, but examples thereof include an organic film provided for forming an etching mask in the process of manufacturing a semiconductor device.

  A solution-type surface treatment agent to which a solvent is added can be applied to the surface of an object to be treated such as a substrate by means of a spin coating method or a dipping method, for example.

  The surface treating agent of the present invention contains a silylating agent and a nitrogen-containing heterocyclic compound containing no silicon atom (hereinafter also referred to as a heterocyclic compound). Hereinafter, each component will be described.

[Silylating agent]
First, the silylating agent used in the surface treating agent of the present invention will be described. The silylating agent used in the surface treatment agent of the present invention is a component for silylating the surface of the object to be treated and increasing the hydrophobicity of the surface of the object to be treated.
The silylating agent contained in the surface treatment agent of the present invention is not particularly limited, and any conventionally known silylating agent can be used. As such a silylating agent, for example, a silylating agent having a substituent represented by the following general formula (2) or a cyclic silazane compound can be used.

（上記一般式（２）中、Ｒ^４、Ｒ^５及びＲ^６は、それぞれ独立に水素原子、ハロゲン原子、含窒素基又は有機基を表し、Ｒ^４、Ｒ^５及びＲ^６に含まれる炭素原子の合計の個数は１個以上である。）

(In the general formula (2), R ⁴ , R ⁵ and R ⁶ each independently represents a hydrogen atom, a halogen atom, a nitrogen-containing group or an organic group, and carbon atoms contained in R ⁴ , R ⁵ and R ^6. The total number of is one or more.)

  More specifically, as the silylating agent having a substituent represented by the general formula (2), silylating agents represented by the following general formulas (3) to (8) can be used.

（上記一般式（３）中、Ｒ^４、Ｒ^５及びＲ^６は、上記一般式（２）と同様であり、Ｒ^７は、水素原子、又は飽和若しくは不飽和アルキル基を表し、Ｒ^８は、水素原子、飽和若しくは不飽和アルキル基、飽和若しくは不飽和シクロアルキル基、アセチル基、又は飽和若しくは不飽和ヘテロシクロアルキル基を表す。Ｒ^７及びＲ^８は、互いに結合して窒素原子を含む環構造を形成してもよい。）

(In the general formula (3), R ⁴ , R ⁵ and R ⁶ are the same as those in the general formula (2), R ⁷ represents a hydrogen atom or a saturated or unsaturated alkyl group, and R ⁸ is 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, and R ⁷ and R ⁸ are a ring containing a nitrogen atom bonded to each other. A structure may be formed.)

（上記一般式（４）中、Ｒ^４、Ｒ^５及びＲ^６は、上記一般式（２）と同様であり、Ｒ^９は、水素原子、メチル基、トリメチルシリル基、又はジメチルシリル基を表し、Ｒ^１０、Ｒ^１１及びＲ^１２は、それぞれ独立に水素原子又は有機基を表し、Ｒ^１０、Ｒ^１１及びＲ^１２に含まれる炭素原子の合計の個数は１個以上である。）

(In the general formula (4), R ⁴ , R ⁵ and R ⁶ are the same as those in the general formula (2), R ⁹ represents a hydrogen atom, a methyl group, a trimethylsilyl group, or a dimethylsilyl group, R ¹⁰ , R ¹¹ and R ¹² each independently represent a hydrogen atom or an organic group, and the total number of carbon atoms contained in R ¹⁰ , R ¹¹ and R ¹² is 1 or more.)

（上記一般式（５）中、Ｒ^４、Ｒ^５及びＲ^６は、上記一般式（２）と同様であり、Ｘは、Ｏ、ＣＨＲ^１４、ＣＨＯＲ^１４、ＣＲ^１４Ｒ^１４、又はＮＲ^１５を表し、Ｒ^１３及びＲ^１４はそれぞれ独立に水素原子、飽和若しくは不飽和アルキル基、飽和若しくは不飽和シクロアルキル基、トリアルキルシリル基、トリアルキルシロキシ基、アルコキシ基、フェニル基、フェニルエチル基、又はアセチル基を表し、Ｒ^１５は、水素原子、アルキル基、又はトリアルキルシリル基を表す。）

(In the above general formula (5), R ⁴ , R ⁵ and R ⁶ are the same as in the above general formula (2), and X represents O, CHR ¹⁴ , CHOR ¹⁴ , CR ¹⁴ R ¹⁴ , or NR ¹⁵ . R ¹³ and R ¹⁴ are each independently a hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, a trialkylsilyl group, a trialkylsiloxy group, an alkoxy group, a phenyl group, a phenylethyl group, or Represents an acetyl group, and R ¹⁵ represents a hydrogen atom, an alkyl group, or a trialkylsilyl group.)

（上記一般式（６）中、Ｒ^４、Ｒ^５及びＲ^６は、上記一般式（２）と同様であり、Ｒ^９は、上記一般式（４）と同様であり、Ｒ^１４は、水素原子、飽和若しくは不飽和アルキル基、トリフルオロメチル基、又はトリアルキルシリルアミノ基を表す。）

(In the general formula (6), R ⁴ , R ⁵ and R ⁶ are the same as the general formula (2), R ⁹ is the same as the general formula (4), and R ¹⁴ is hydrogen. Represents an atom, a saturated or unsaturated alkyl group, a trifluoromethyl group, or a trialkylsilylamino group.)

（上記一般式（７）中、Ｒ^１５及びＲ^１６は、それぞれ独立に水素原子、アルキル基、トリアルキルシリル基を表し、Ｒ^１５及びＲ^１６の少なくとも一つは、トリアルキルシリル基を表す。）

(In the general formula (7), R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, an alkyl group, or a trialkylsilyl group, and at least one of R ¹⁵ and R ¹⁶ represents a trialkylsilyl group. )

（上記一般式（８）中、Ｒ^１７はトリアルキルシリル基を表し、Ｒ^１８及びＲ^１９は、それぞれ独立に水素原子又は有機基を表す。）

(In the general formula (8), R ¹⁷ represents a trialkylsilyl group, and R ¹⁸ and R ¹⁹ each independently represent a hydrogen atom or an organic group.)

（上記一般式（９）中、Ｒ^４、Ｒ^５及びＲ^６は、上記一般式（２）と同様であり、Ｒ^２０は、有機基を表し、Ｒ^２１は、存在しないか、存在する場合、−ＳｉＲ^２２Ｒ^２３Ｒ^２４を表す。Ｒ^２２、Ｒ^２３及びＲ^２４は、それぞれ独立に水素原子、ハロゲン原子、含窒素基又は有機基を表す。）

(In the above general formula (9), R ⁴ , R ⁵ and R ⁶ are the same as in the above general formula (2), R ²⁰ represents an organic group, and R ²¹ is not present or present. , -SiR ²² R ²³ R ^24. R ²² , R ²³ and R ²⁴ each independently represents a hydrogen atom, a halogen atom, a nitrogen-containing group or an organic group.

  Examples of the silylating agent represented by the above formula (3) include N, N-dimethylaminotrimethylsilane, N, N-dimethylaminodimethylsilane, N, N-dimethylaminomonomethylsilane, N, N-diethylaminotrimethylsilane, t-butylaminotrimethylsilane, allylaminotrimethylsilane, trimethylsilylacetamide, N, N-dimethylaminodimethylvinylsilane, N, N-dimethylaminodimethylpropylsilane, N, N-dimethylaminodimethyloctylsilane, N, N- Dimethylaminodimethylphenylethylsilane, N, N-dimethylaminodimethylphenylsilane, N, N-dimethylaminodimethyl-t-butylsilane, N, N-dimethylaminotriethylsilane, trimethylsilanamine, monomethylsilylimidazole Dimethylsilyl imidazole, trimethylsilyl imidazole, monomethyl silyl triazole, dimethyl silyl triazole, and trimethylsilyl triazole and the like.

  Examples of the silylating agent represented by the above formula (4) include hexamethyldisilazane, N-methylhexamethyldisilazane, 1,1,3,3-tetramethyldisilazane, 1,3-dimethyldisilazane, , 2-Di-N-octyltetramethyldisilazane, 1,2-divinyltetramethyldisilazane, heptamethyldisilazane, nonamethyltrisilazane, tris (dimethylsilyl) amine, tris (trimethylsilyl) amine, pentamethylethyldi Examples include silazane, pentamethylvinyldisilazane, pentamethylpropyldisilazane, pentamethylphenylethyldisilazane, pentamethyl-t-butyldisilazane, pentamethylphenyldisilazane, and trimethyltriethyldisilazane.

  Examples of the silylating agent represented by the above formula (5) include trimethylsilyl acetate, dimethylsilyl acetate, monomethylsilyl acetate, trimethylsilylpropionate, trimethylsilylbutyrate, trimethylsilyloxy-3-penten-2-one, and the like.

  Examples of the silylating agent represented by the above formula (6) include bis (trimethylsilyl) urea, N-trimethylsilylacetamide, N-methyl-N-trimethylsilyltrifluoroacetamide, and the like.

  Examples of the compound represented by the above formula (7) include bis (trimethylsilyl) trifluoroacetamide and the like, and examples of the compound represented by the above formula (8) include 2-trimethylsiloxypent-2-ene-4- ON etc. are mentioned. Examples of the compound represented by the above formula (9) include 1,2-bis (dimethylchlorosilyl) ethane, t-butyldimethylchlorosilane and the like.

  As the cyclic silazane compound, 2,2,5,5-tetramethyl-2,5-disila-1-azacyclopentane, 2,2,6,6-tetramethyl-2,6-disila-1-azacyclohexane Cyclic trisilazane compounds such as 2,2,4,4,6,6-hexamethylcyclotrisilazane, cyclic trisilazane compounds such as 2,4,6-trimethyl-2,4,6-trivinylcyclotrisilazane; 2 , 2,4,4,6,6,8,8-octamethylcyclotetrasilazane and the like; and the like.

  Here, focusing on the substituent bonded to the silicon atom, a silylating agent having a large number of carbon atoms contained in the substituent, a so-called bulky substituent bonded to the silicon atom may be used. preferable. When the surface treatment agent contains such a silylating agent, the hydrophobicity of the surface of the object to be treated that has been treated with the surface treatment agent can be increased. When the object to be processed is a substrate, it is possible to improve the adhesion between the surface of the substrate that has been processed and the resin pattern. Further, as will be described later, among the treated substrate surfaces, the hydrophobicity of the surface of the inorganic pattern or the resin pattern, in particular, increases, so that the pattern collapse of the inorganic pattern or the resin pattern can be prevented. .

Therefore, in the general formula (2), it is preferred that the total number of carbon atoms contained in R ^4, R ⁵ and R ⁶ is 3 or more. Among these, from the viewpoint of obtaining sufficient reactivity in the silylation reaction, any one of R ⁴ , R ⁵ and R ⁶ in the general formula (2) is an organic group having 2 or more carbon atoms (hereinafter, In this paragraph, it is referred to as “specific organic group”), and it is more preferable that the remaining two are each independently a methyl group or an ethyl group. The specific organic group may have a branched and / or substituted alkyl group having 2 to 20 carbon atoms, an optionally substituted vinyl group, or an optionally substituted group. An aryl group etc. are illustrated. 2-12 are more preferable, as for the carbon atom number of a specific organic group, 2-10 are more preferable, and 2-8 are especially preferable.

  From such a viewpoint, among the silylating agents exemplified above, N, N-dimethylaminodimethylvinylsilane, N, N-dimethylaminodimethylpropylsilane, N, N-dimethylaminodimethyloctylsilane, N, N-dimethyl Aminodimethylphenylethylsilane, N, N-dimethylaminodimethylphenylsilane, N, N-dimethylaminodimethyl-t-butylsilane, N, N-dimethylaminotriethylsilane, N, N-dimethylaminotrimethylsilane, pentamethylethyldi Preferred examples include silazane, pentamethylvinyldisilazane, pentamethylpropyldisilazane, pentamethylphenylethyldisilazane, pentamethyl-t-butyldisilazane, pentamethylphenyldisilazane, and trimethyltriethyldisilazane. .

  The silylating agents exemplified above can be used alone or in admixture of two or more.

[Heterocyclic compounds]
The surface treatment agent includes a nitrogen-containing heterocyclic compound containing no silicon atom (also simply referred to as a heterocyclic compound).

  Until now, the silylation of the surface of the object such as the substrate, for example, when hexamethyldisilazane (HMDS) is used as a silylating agent, the reactivity of the silylating agent is not sufficient. It may take time, or sufficient hydrophobicity on the surface of the object to be treated may not be obtained.

However, when the surface treatment agent includes a silylating agent and a nitrogen-containing heterocyclic compound containing no silicon atom, the silylation reaction by the silylating agent is promoted by the catalytic action of the nitrogen-containing heterocyclic compound, and the object to be treated The surface of is highly hydrophobized.
Therefore, when the silylation treatment is performed on the surface of the object to be treated using the surface treatment agent of the present invention, the surface of the object to be treated can be highly hydrophobized. If the surface treatment agent of the present invention is used to hydrophobize the surface of the object to be treated to the same extent as before, the time required for the surface treatment can be shortened.

The heterocyclic compound is not particularly limited as long as it does not contain a silicon atom and contains a nitrogen atom in the ring structure. The heterocyclic compound may contain a hetero atom other than a nitrogen atom such as an oxygen atom or a sulfur atom in the ring.
The heterocyclic compound is preferably a compound containing a nitrogen-containing heterocyclic ring having aromaticity. When the heterocyclic compound contains a nitrogen-containing heterocyclic ring having aromaticity, the hydrophobicity of the surface of the object to be treated treated with the surface treatment agent can be increased.

The heterocyclic compound may be a compound in which two or more rings are bonded by a single bond or a divalent or higher polyvalent linking group. In this case, the two or more rings connected by the linking group may contain at least one nitrogen-containing heterocycle.
Among the polyvalent linking groups, a divalent linking group is preferable from the viewpoint that the steric hindrance between the rings is small. Specific examples of the divalent linking group include an alkylene group having 1 to 6 carbon atoms, —CO—, —CS—, —O—, —S—, —NH—, —N═N—, —CO—. O-, -CO-NH-, -CO-S-, -CS-O-, -CS-S-, -CO-NH-CO-, -NH-CO-NH-, -SO-, and -SO ₂ etc. are mentioned.
The number of rings contained in a compound in which two or more rings are bonded by a polyvalent linking group is preferably 4 or less, more preferably 3 or less, and most preferably 2 from the viewpoint of easy preparation of a uniform surface treatment agent. preferable. For example, a condensed ring such as a naphthalene ring has 2 rings.

The heterocyclic compound may be a nitrogen-containing heterocyclic compound in which two or more rings are condensed. In this case, at least one of the rings constituting the condensed ring may be a nitrogen-containing heterocyclic ring.
The number of rings contained in the nitrogen-containing heterocyclic compound in which two or more rings are condensed is preferably 4 or less, more preferably 3 or less, and most preferably 2 from the viewpoint of easy preparation of a uniform surface treatment agent.

  The heterocyclic compound preferably contains a nitrogen-containing 5-membered ring or a condensed polycycle containing a nitrogen-containing 5-membered ring skeleton from the viewpoint that the effect of the surface treatment using the surface treatment agent is good.

Preferable examples of the heterocyclic compound include, for example, pyridine, pyridazine, pyrazine, pyrimidine, triazine, tetrazine, pyrrole, pyrazole, imidazole, triazole, tetrazole, oxazole, isoxazole, thiazole, isothiazole, oxadiazole, thiadiazole, Quinoline, isoquinoline, cinnoline, phthalazine, quinoxaline, quinazoline, indole, indazole, benzimidazole, benzotriazole, benzoxazole, benzisoxazole, benzothiazole, benzoisothiazole, benzoxiadiazole, saccharin, pyrrolidine, and piperidine Is mentioned.
Among these, pyrrole, pyrazole, imidazole, triazole, tetrazole, oxazole, isoxazole, thiazole, isothiazole, oxadiazole, thiadiazole, indole, indazole, benzimidazole, benzotriazole, benzoxazole, benzoisoxazole, benzothiazole , Benzoisothiazole, benzooxadiazole, benzothiadiazole, and saccharin are preferable, and imidazole, triazole, tetrazole, benzotriazole, and pyrazole are more preferable.
The above heterocyclic compounds having a substituent are also preferably used.

Examples of the substituent that the heterocyclic compound may have include an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and 3 to 3 carbon atoms. 8 cycloalkyloxy group, aryl group having 6 to 20 carbon atoms, aralkyl group having 7 to 20 carbon atoms, halogenated alkyl group having 1 to 6 carbon atoms, aliphatic acyl group having 2 to 7 carbon atoms , Halogenated aliphatic acyl group having 2 to 7 carbon atoms, arylcarbonyl group having 7 to 20 carbon atoms, carboxyalkyl group having 2 to 7 carbon atoms, halogen atom, hydroxyl group, mercapto group, 1 to carbon atoms 6 alkylthio groups, amino groups, monoalkylamino groups including alkyl groups having 1 to 6 carbon atoms, dialkylamino groups including alkyl groups having 1 to 6 carbon atoms, nitro groups, and cyano groups. It is.
The heterocyclic compound may have a plurality of substituents on the heterocyclic ring. When the number of substituents is plural, the plural substituents may be the same or different.
When these substituents include an aliphatic hydrocarbon ring or an aromatic hydrocarbon ring, these rings may further have the same substituent as the substituent that the heterocyclic compound may have. Good.

The alkyl group as a substituent has 1 to 6 carbon atoms, preferably 1 to 4 and more preferably 1 or 2. Specific examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, and n-pentyl group. And n-hexyl group.
Among these, a methyl group and an ethyl group are preferable, and a methyl group is more preferable.

  The carbon atom number of the cycloalkyl group as a substituent is 3-8, 3-7 are preferable and 4-6 are more preferable. Specific examples of the cycloalkyl group having 3 to 8 carbon atoms are a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.

The number of carbon atoms of the alkoxy group as a substituent is 1 to 6, preferably 1 to 4, and more preferably 1 or 2. Specific examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-butyloxy group, isobutyloxy group, sec-butyloxy group, tert-butyloxy group, n -A pentyloxy group, n-hexyloxy group, etc. are mentioned.
In these, a methoxy group and an ethoxy group are preferable, and a methoxy group is more preferable.

  The carbon atom number of the cycloalkyloxy group as a substituent is 3-8, 3-7 are preferable and 4-6 are more preferable. Specific examples of the cycloalkyloxy group having 3 to 8 carbon atoms are a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, a cycloheptyloxy group, and a cyclooctyloxy group.

  The aryl group as a substituent has 6 to 20 carbon atoms, and preferably 6 to 12 carbon atoms. Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl group, α-naphthyl group, β-naphthyl group, biphenyl-4-yl group, biphenyl-3-yl group, biphenyl-2-yl group, anthracene -1-yl group, anthracen-2-yl group, anthracen-9-yl group, phenanthren-1-yl group, phenanthren-2-yl group, phenanthren-3-yl group, phenanthren-4-yl group, and phenanthrene A -9-yl group is mentioned. Among these, a phenyl group, an α-naphthyl group, a β-naphthyl group, a biphenyl-4-yl group, a biphenyl-3-yl group, and a biphenyl-2-yl group are preferable, and a phenyl group is more preferable.

  The carbon number of the aralkyl group as a substituent is 7-20, and 7-12 are preferable. Specific examples of the aralkyl group having 7 to 20 carbon atoms include benzyl group, phenethyl group, 3-phenyl-n-propyl group, 4-phenyl-n-butyl group, α-naphthylmethyl group, β-naphthylmethyl group. , 2- (α-naphthyl) ethyl group, and 2- (β-naphthyl) ethyl group. Among these groups, a benzyl group and a phenethyl group are preferable, and a benzyl group is more preferable.

Examples of the halogen atom contained in the halogenated alkyl group as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogenated alkyl group as a substituent has 1 to 6 carbon atoms, preferably 1 to 4 and more preferably 1 or 2.
Specific examples of the halogenated alkyl group having 1 to 6 carbon atoms include chloromethyl group, dichloromethyl group, trichloromethyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2 , 2,2-trifluoroethyl group, and pentafluoroethyl group.

  The number of carbon atoms of the aliphatic acyl group as a substituent is 2 to 7, preferably 2 to 5, and more preferably 2 or 3. Specific examples of the aliphatic acyl group having 2 to 7 carbon atoms include acetyl group, propionyl group, butanoyl group, pentanoyl group, hexanoyl group, and heptanoyl. In these, an acetyl group and a propanoyl group are preferable, and an acetyl group is more preferable.

Examples of the halogen atom contained in the halogenated aliphatic acyl group as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogenated aliphatic acyl group as a substituent has 2 to 7 carbon atoms, preferably 2 to 5 and more preferably 1 or 2.
Specific examples of the halogenated aliphatic acyl group having 2 to 7 carbon atoms include chloroacetyl group, dichlororoacetyl group, trichloroacetyl group, fluoroacetyl group, difluoroacetyl group, trifluoroacetyl group, and pentafluoropropionyl group. is there.

The carbon atom number of the arylcarbonyl group as a substituent is 7-20, and 7-13 are preferable.
Specific examples of the arylcarbonyl group having 7 to 20 carbon atoms are a benzoyl group, an α-naphthoyl group, and a β-naphthoyl group.

  The carbon atom number of the carboxyalkyl group as a substituent is 2-7, 2-5 are preferable and 2 or 3 is more preferable. Specific examples of the carboxyalkyl group having 2 to 7 carbon atoms include carboxymethyl group, 2-carboxyethyl group, 3-carboxy-n-propyl group, 4-carboxy-n-butyl group, 5-carboxy-n- A pentyl group and 6-carboxy-n-hexyl group are mentioned. In these, a carboxymethyl group is preferable.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. In these, a fluorine atom, a chlorine atom, and a bromine atom are preferable, and a chlorine atom and a bromine atom are more preferable.

The alkylthio group as a substituent has 1 to 6 carbon atoms, preferably 1 to 4 and more preferably 1 or 2. Specific examples of the alkylthio group having 1 to 6 carbon atoms include methylthio group, ethylthio group, n-propylthio group, isopropylthio group, n-butylthio group, isobutylthio group, sec-butylthio group, tert-butylthio group, n- Examples thereof include a pentylthio group and an n-hexylthio group.
Among these, a methylthio group and an ethylthio group are preferable, and a methylthio group is more preferable.

Specific examples of the alkyl group contained in the monoalkylamino group containing an alkyl group having 1 to 6 carbon atoms and the dialkylamino group containing an alkyl group having 1 to 6 carbon atoms are as follows. The same as the specific example.
As a monoalkylamino group containing a C1-C6 alkyl group, an ethylamino group and a methylamino group are preferable, and a methylamino group is more preferable.
As a dialkylamino group containing a C1-C6 alkyl group, a diethylamino group and a dimethylamino group are preferable, and a dimethylamino group is more preferable.

As a particularly preferable specific example of the heterocyclic compound, a compound represented by the following formula may be mentioned.

The addition amount of the heterocyclic compound in the surface treatment agent is not particularly limited as long as the object of the present invention is not impaired. The addition amount of the heterocyclic compound in the surface treatment agent is preferably 0.1 to 20 mol, more preferably 0.2 to 10 mol, and most preferably 0.5 to 5 mol with respect to 1 mol of the silylating agent. preferable.
When the addition amount of the heterocyclic compound is within the above range, the silylation reaction by the surface treatment agent is promoted, and the surface hydrophobicity of the object to be treated, which is the treatment target, is easily improved.

[solvent]
The surface treatment agent may contain a solvent. When the surface treatment agent contains a solvent, the surface treatment of the object to be treated by a spin coating method, a dipping method or the like becomes easy. Next, the solvent that can be contained in the surface treatment agent will be described.

  The solvent is not particularly limited as long as it can dissolve the silylating agent and the heterocyclic compound and has little damage to the surface of the object to be treated (for example, the surface of the substrate (inorganic pattern, resin pattern, etc.)). Conventionally known solvents can be used.

Specifically, sulfoxides such as dimethyl sulfoxide;
Sulfones such as dimethylsulfone, diethylsulfone, bis (2-hydroxyethyl) sulfone, tetramethylenesulfone;
Amides such as N, N-dimethylformamide, N-methylformamide, N, N-dimethylacetamide, N-methylacetamide, N, N-diethylacetamide;
Lactams such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone;
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, methyl ethyl diglycol, diethyl glycol, triethylene glycol butyl methyl ether;
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, di Propylene glycol mono Chirueteru, dipropylene glycol mono -n- propyl ether, dipropylene glycol mono -n- butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl (poly) alkylene glycol monoalkyl ethers such as ether;
(Poly) alkylene glycol mono, 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 Alkyl ether acetates;
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 diethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran;
Ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone;
Lactic acid alkyl esters such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate; ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid Methyl, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxy Butylpropionate, 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, formic acid n-pentyl, i-pentyl acetate, propio N-butyl acid, 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 , Other esters such as ethyl acetoacetate, ethyl 2-oxobutanoate, dimethyl adipate, propylene glycol diacetate;
Lactones such as β-propyrolactone, γ-butyrolactone, δ-pentyrolactone;
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 and the like linear, branched or cyclic aliphatic hydrocarbons;
Aromatic hydrocarbons such as benzene, toluene, xylene, 1,3,5-trimethylbenzene, naphthalene;
and terpenes such as p-menthane, diphenylmenthane, limonene, terpinene, bornane, norbornane, and pinane; These solvents can be used alone or in admixture of two or more.

When a nonpolar solvent is used, the heterocyclic compound is slightly difficult to dissolve, and the surface treatment agent may contain crystals of the heterocyclic compound.
When it is necessary to use a non-polar solvent in the surface treatment agent due to the relationship with the post-treatment of the surface treatment with the surface treatment agent, the heterocyclic compound deposited as necessary after the surface treatment with the surface treatment agent It is preferable to provide a step of removing the crystals.

  In addition, when the object to be treated by the surface treating agent of the present invention is an organic material such as a resin pattern, an ether solvent having 2 to 14 carbon atoms from the viewpoint that damage to the object to be treated can be reduced. Are preferably used, and ether solvents having 3 to 12 carbon atoms are more preferably used. Specific examples of such ether solvents include alkyl ethers such as dimethyl ether, diethyl ether, methyl ethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, and diisoamyl ether. Among these, diisopropyl ether, dibutyl ether and diisoamyl ether are preferable. The said ether solvent can be used individually or in combination of 2 or more types.

  When the solvent is contained in the surface treatment agent of the present invention, the total concentration of the silylating agent and the heterocyclic compound contained in the surface treatment agent is practically preferably 0.1% by mass or more. 30 mass% is more preferable, 0.5-20 mass% is especially preferable, and 1-15 mass% is the most preferable.

  The surface treatment agent described above hardly elutes metal even when it comes into contact with a metal such as SUS. For example, even if a test piece containing iron is immersed in a surface treatment agent at room temperature for 5 days or more, the elution of iron into the surface treatment agent is 3 ppb or less.

<Surface treatment method>
Next, the surface treatment method of the present invention will be described.
In the surface treatment method of the present invention, the surface of the object to be treated is treated by exposing the surface treatment agent of the present invention to the surface of the object to be treated.

  When the object to be processed is a substrate, as already described, the surface of the substrate to be processed in the surface treatment method of the present invention is not only the surface of the substrate itself, but also an inorganic pattern and a resin pattern provided on the substrate. As well as the surfaces of unpatterned inorganic and organic layers. Since the description of the inorganic pattern and the resin pattern provided on the substrate, and the surfaces of the inorganic layer and the organic layer that are not patterned are as described above, the description is omitted here.

  In the surface treatment method of the present invention, the surface of the object to be treated is subjected to silylation treatment, and the purpose of the treatment may be any, but as a typical example of the purpose of the treatment, (1) Hydrophobizing the surface of an object to be processed such as a substrate and improving adhesion to a resin pattern made of, for example, a photoresist, etc. (2) During cleaning of the surface of an object to be processed which is a substrate, For example, preventing the pattern or the resin pattern from collapsing.

Regarding (1) above, as a method for exposing the surface treatment agent of the present invention to the surface of the object to be treated, a conventionally known method can be used without particular limitation. For example, the surface treatment agent of the present invention is used. Examples thereof include a method of vaporizing into vapor and bringing the vapor into contact with the surface of the object to be treated, and a method of bringing the surface treatment agent of the present invention into contact with the surface of the object to be treated by spin coating or dipping.
When the substrate used for forming the organic layer which is a photoresist film is an object to be processed, the surface treatment agent is preferably exposed before the organic layer is formed.
By such an operation, the surface of the object to be processed is silylated, and the hydrophobicity of the surface of the object to be processed is improved. In the case where a substrate to be processed is a substrate and a substrate treated with a surface treatment agent is used, the substrate surface is hydrophobized, thereby improving the adhesion of the substrate to, for example, a photoresist or the like.

  Regarding (2) above, the surface treatment agent of the present invention may be exposed to the surface of the substrate as the object to be treated before performing the cleaning operation after forming the inorganic pattern or the resin pattern. Next, the reason why it is possible to prevent the pattern collapse of the inorganic pattern or the resin pattern on the surface of the substrate by performing such surface treatment during the cleaning of the surface of the substrate will be described.

Usually, after an inorganic pattern is formed on the surface of a substrate, the pattern surface is generally cleaned with a cleaning solution such as SPM (sulfuric acid / hydrogen peroxide solution) or APM (ammonia / hydrogen peroxide solution). . Further, even after the resin pattern is formed on the surface of the substrate, the development residue and the attached developer are generally washed away with a cleaning solution such as water or an activator rinse.
In the surface treatment method of the present invention, before washing such an inorganic pattern or resin pattern, the pattern surface is treated with the surface treatment agent of the present invention to make the surface of the pattern hydrophobic.

Here, the force F acting between patterns such as an inorganic pattern and a resin pattern at the time of cleaning is represented by the following formula (I). Where γ represents the surface tension of the cleaning liquid, θ represents the contact angle of the cleaning liquid, A represents the aspect ratio of the pattern, and D represents the distance between the pattern sidewalls.
F = 2γ · cos θ · A / D (I)

  Therefore, if the surface of the pattern can be made hydrophobic and the contact angle of the cleaning liquid can be increased (cos θ is reduced), the force acting between the patterns during subsequent cleaning can be reduced, and pattern collapse can be prevented.

  This surface treatment is performed by immersing the substrate on which the inorganic pattern or the resin pattern is formed in the surface treatment agent, or by applying or spraying the surface treatment agent onto the inorganic pattern or the resin pattern. The treatment time is preferably 1 to 60 seconds. Moreover, after this surface treatment, the contact angle of water on the pattern surface is preferably 40 to 120 degrees, and more preferably 60 to 100 degrees.

  When the above surface treatment is completed, the inorganic pattern or the resin pattern is washed. For this cleaning process, a cleaning solution that has been conventionally used for cleaning an inorganic pattern or a resin pattern can be used as it is. For example, SPM, APM, etc. are mentioned about an inorganic pattern, Water, an activator rinse, etc. are mentioned about a resin pattern.

  From the viewpoint of throughput, it is preferable that the surface treatment and the cleaning treatment are continuous treatments. For this reason, it is preferable to select a surface treatment agent that is excellent in substitution with the cleaning liquid.

  As described in the surface treatment agent of the present invention, the surface treatment agent used in the surface treatment method of the present invention contains a silylating agent and a nitrogen-containing heterocyclic compound not containing a silicon atom. The nitrogen-containing heterocyclic compound containing no atoms is a compound that functions as a catalyst when silylating the surface of an object to be treated. For this reason, the surface of the to-be-processed object processed with the surface treatment method of this invention is highly hydrophobized (silylation). When the object to be processed is a substrate used for forming a resin pattern or an inorganic pattern, the adhesion to the resin pattern or the like is improved as a result of the surface treatment, or pattern collapse is prevented.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

[Examples 1 to 52 and Comparative Examples 1 to 8]
In Examples and Comparative Examples, the following silylating agents, SA1 to SA3, SA4: 2,2,5,5-tetramethyl-2,5-disila-1-azacyclopentane, SA5: 2,2,4, 4,6,6-Hexamethylcyclotrisilazane was used.

In Examples and Comparative Examples, the following H1 to H8 were used as nitrogen-containing heterocyclic compounds not containing silicon atoms.

In Examples and Comparative Examples, the following S1 to S15 were used as solvents.
S1: Propylene glycol monomethyl ether acetate S2: n-butyl acetate S3: ethyl acetate S4: γ-butyrolactone S5: high boiling point solvent (triethylene glycol butyl methyl ether, boiling point: 261 ° C.)
S6: Tetraethylene glycol dimethyl ether S7: Diethylene glycol diethyl ether S8: 3-methoxybutyl acetate S9: 3-methyl-3-methoxybutyl acetate S10: Ethylene glycol monobutyl ether acetate S11: Propylene glycol diacetate S12: Diethylene glycol monoethyl ether acetate S12 : Dimethyl adipate S13: Methyl decanoate
S14: methyl n-octanoate S15: n-octyl acetate

Each of the types and amounts (mass%) described in Tables 1 to 3 were uniformly mixed with a silylating agent, a heterocyclic compound, and a solvent to obtain surface treating agents of Examples and Comparative Examples. .
In addition, in the surface treating agents of Examples 15 to 19, some undissolved residues of the heterocyclic compound occurred.
Using the obtained surface treatment agent, the silicon substrate (Si), the silicon thermal oxide film substrate (thOx), and the silicon nitride substrate (SiN) are subjected to surface treatment according to the following method, and water contact after the surface treatment is performed. The corner was measured. The measurement results of the water contact angle are shown in Tables 1 to 3.
The contact angle of water is measured by dropping a pure water droplet (1.8 μL) on the surface of the surface-treated substrate using Dropmaster 700 (manufactured by Kyowa Interface Science Co., Ltd.) and measuring the contact angle 10 seconds after the dropping. did.

<Surface treatment method>
First, the substrate was immersed in an HF aqueous solution having a concentration of 1% by mass at 25 ° C. for 1 minute. After immersion, the substrate was washed with ion exchange distilled water for 1 minute. The substrate after washing with water was dried with a nitrogen stream.
The substrate after the drying was immersed in the surface treatment agent of each Example and Comparative Example at 25 ° C. for 60 seconds to perform the surface treatment of the substrate. The substrate after the surface treatment was washed with isopropyl alcohol 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.

  Comparison between Comparative Example 1 and Examples 1 to 3, Comparison Example 2 and Comparison between Examples 4 to 6, Comparison between Comparative Example 3 and Examples 5 to 9, Comparison Example 7 and Example 22 And the comparison between Comparative Example 8 and Example 23 showed that the surface treatment agent contained a nitrogen-containing heterocyclic compound containing no silicon atom together with the silylating agent, so that silylation during the surface treatment was achieved. It can be seen that the efficiency of hydrophobization by the agent is significantly improved.

  From the comparison between Comparative Example 1 and Comparative Examples 4 and 5, even if the nitrogen-containing heterocyclic compound was contained in the surface treatment agent as a silylation agent containing a silicon atom, the hydrophobicity by the silylation agent during the surface treatment was It turns out that efficiency does not improve so much.

  From the comparison between Example 6 and Examples 10 to 13 and Examples 24 to 33, the surface treatment agent containing a nitrogen-containing heterocyclic compound not containing a silicon atom together with a silylating agent, regardless of the type of solvent. It can be seen that a good surface treatment effect can be obtained.

According to a comparison between Example 6 and Examples 14 to 21 and Examples 34 to 52, the use of various compounds as the heterocyclic compound, and the desire for improving the efficiency of hydrophobization by the silylating agent during the surface treatment It turns out that the effect to do is acquired.
In particular, according to Examples 15 to 19, 34, 37, 39, and 41 to 50, even when the content of the heterocyclic compound is slightly low, the effect of good hydrophobization by the surface treatment agent is not greatly impaired. I understand.

Claims (4)

  A surface treatment agent used for surface treatment of an object to be treated, comprising a silylating agent and a nitrogen-containing heterocyclic compound containing no silicon atom.   The surface treating agent according to claim 1, wherein the nitrogen-containing heterocyclic compound contains a condensed polycycle containing a nitrogen-containing 5-membered ring or a nitrogen-containing 5-membered ring skeleton.   Furthermore, the surface treating agent of Claim 1 or 2 containing a solvent.   The surface treatment method which exposes the surface treating agent of any one of Claims 1-3 to the surface of a to-be-processed object, and processes the surface of the said to-be-processed object.