WO2012157507A1

WO2012157507A1 - Surface-treating agent and surface treatment method

Info

Publication number: WO2012157507A1
Application number: PCT/JP2012/061972
Authority: WO
Inventors: 尚正古田; 鈴木　浩; 勝可原田; 柱賢鄭
Original assignee: 東亞合成株式会社
Priority date: 2011-05-17
Filing date: 2012-05-10
Publication date: 2012-11-22
Also published as: JPWO2012157507A1; TW201311771A

Abstract

The present invention is a surface-treating agent suitable for rendering the surface of an object of interest water-repellent, which comprises a compound (A) represented by general formula (1). [In the formula, R⁶ represents a hydrogen atom or an alkyl group having 1-6 carbon atoms; R¹, R², R³, R⁴ and R⁵ independently represent a hydrogen atom, a cyanoalkyl group, an alkyl group, an aralkyl group, a cycloalkyl group, a cycloaralkyl group or an aryl group, wherein at least one of R¹, R², R³, R⁴ and R⁵ represents a hydrogen atom; and a, w, x, y and z independently represent 0 or a positive number, wherein w and/or x represents a positive number and the following formulae 0 ≤ w/(x+y) ≤ 5 and 0 ≤ z/(a+w+x+y) ≤ 1 are fulfilled.]

Description

Surface treatment agent and surface treatment method

The present invention relates to a surface treatment agent and a surface treatment method for improving the water repellency of a surface of an object to be treated, and more specifically, a surface treatment agent for making a substrate surface of a liquid crystal, a semiconductor or the like to which a lithography technique is applied to be water repellent. The present invention also relates to a surface treatment method for making a substrate surface water repellent using the surface treatment agent.

In the manufacture of semiconductor devices and the like, lithography technology is used when processing such as etching on a substrate. In lithography technology, a photosensitive resin layer is provided on a substrate using a photosensitive resin composition, and then exposed to selective irradiation with actinic radiation for exposure and development, and then a photosensitive resin layer. Is selectively dissolved and removed, a resin pattern is formed on the substrate, and an etching process is performed using the resin pattern as a mask, whereby a pattern to be etched is formed on the substrate.

There are various types of substrates used for liquid crystals, semiconductors, and the like, and a photosensitive resin layer is formed in order to build a plurality of types of elements and circuits on the substrate. The surface of a semiconductor substrate to which lithography technology is applied can be a mixture of various surface states, such as a previously formed surface or a surface after being removed by etching. For example, a SiO ₂ film is usually formed on the surface of a silicon wafer before manufacturing a semiconductor product, and moisture in the atmosphere is bonded to the outermost surface of the SiO ₂ film to form Si—OH. It is known that As a method for modifying the surface of a silicon wafer, Patent Document 1 discloses a method for trimethylsilylation by reacting hexamethyldisilazane with an OH group on an oxidized silicon wafer surface after oxidizing the silicon wafer surface. Is disclosed. It is also known that such a water repellency treatment can improve the adhesion between the substrate surface and the resist resin.

In recent years, the trend toward higher integration and miniaturization of semiconductor devices has increased, and the ratio of height to the area of the pattern has increased, and so-called high aspect ratio has been promoted, and a problem called pattern collapse has arisen. ing. This pattern collapse initially, when forming a large number of photosensitive resin patterns in parallel on the substrate, adjacent resin patterns are close to each other, in some cases the resin pattern breaks from the base, It was discovered as a phenomenon of peeling. When such a pattern collapse occurs, a desired product cannot be obtained, which causes a decrease in product yield and reliability. Recently, as the semiconductor element circuit has become more complex, the shape of the semiconductor element has been increased, so that not only the photosensitive resin pattern but also the pattern to be etched, that is, the pattern of the semiconductor element, can be collapsed. Has come to occur.

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 in the drying process, a stress based on the surface tension of the cleaning liquid acts between the patterns, and it is said that the pattern which is a long wall with a high aspect ratio cannot endure and falls down. In Patent Document 2, as a method for preventing pattern collapse, a method for treating a substrate surface using a surface treatment solution obtained by diluting a silylating agent such as N, N-dimethylaminotrimethylsilane or hexamethyldisilazane with an organic solvent. Is disclosed. In Patent Document 3, a plurality of convex patterns having a hydroxyl group on the surface formed on a semiconductor substrate, a surface treatment agent containing a silane coupling agent having a hydrolyzable group that reacts with the hydroxyl group, It is disclosed that a water-repellent protective film having low wettability to water can be formed, and that the water repellency is increased by cleaning the substrate surface using sulfuric acid and hydrogen peroxide.

In Patent Documents 2 and 3, as a method for evaluating the water repellency of the substrate surface, it is described that a contact angle to water is measured, and those having a large contact angle value can suppress pattern collapse. It is known that increasing the contact angle is a solution to pattern collapse.

Patent Document 3 describes that surface treatment with a surface treatment agent can be used for a silicon nitride film, but in the case of a silicon-based film, contact with water after forming a water-repellent protective film. In contrast to the angle of 89 degrees, in the case of a silicon nitride film, only about 46 degrees can be obtained, and the contact angle is improved to 59 degrees by converting the silicon nitride film surface to SiO ₂ with an oxidizing agent. There is a description. That is, a valid and the silicon-based film invention having a hydroxyl group on the surface of the Patent Document 3, there is the effect is not sufficient problems providing water repellency to the silicon nitride film, a surface treatment from once SiO ₂ turned into However, since only water repellency inferior to that of the silicon-based film was obtained, it can be said that the effect was insufficient.

On the other hand, there is no limit to the trend toward higher integration and miniaturization of semiconductor devices, and the effects of conventional surface treatment methods are inadequate as the materials and conditions of the substrate surface diversify. There has been a problem that the yield may be low. In particular, the silicon nitride film is easier to obtain a dense film quality than the oxide film, and also has a characteristic as an antireflection film. Therefore, the silicon nitride film is a material frequently used in recent highly integrated semiconductor devices. A method for providing sufficient water repellency to the surface of the material has been demanded.

JP 62-120031 A JP 2010-129932 A JP 2010-114467 A

The subject of this invention is providing the surface treating agent which improves the water repellency of the surface of to-be-processed objects, such as a board | substrate used for a liquid crystal, a semiconductor, etc. Another object of the present invention is to provide a method for making the surface of an object to be treated such as a semiconductor substrate water repellent using the surface treating agent.

The present invention is shown below.
1. The surface treating agent characterized by including the compound (A) represented by following General formula (1).

[Wherein R ⁶ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom, a cyanoalkyl group, , An alkyl group, an aralkyl group, a cycloalkyl group, a cycloaralkyl group or an aryl group, and at least one of R ¹ , R ² , R ³ , R ⁴ and R ⁵ is a hydrogen atom. a, w, x, y and z are each independently 0 or a positive number, at least one of w and x is a positive number, 0 ≦ w / (x + y) ≦ 5, 0 ≦ z / (a + w + x + y) ≦ 1. Compound A may contain only 1 type of each structural unit, and may contain 2 or more types. ]
2. 2. The surface treating agent according to 1 above, wherein the compound (A) is represented by the following general formula (4).

[Wherein, R ³ and R ⁵ are each independently a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group, a cycloaralkyl group or an aryl group, and w, x and y are independently of each other, It is a positive number and z is 0 or a positive number. ]
3. ^2. The surface treating agent according to 1 above, wherein at least one of R ¹ , R ² , R ³ , R ⁴ and R ^{5 in} the general formula (1) is a cyanoalkyl group.
4). 4. The surface treating agent according to 3 above, wherein the compound (A) is represented by the following general formula (7).

[Wherein, B is a cyanoalkyl group, b, x, y and z are each independently 0 or a positive number, and c is a positive number. ]
5. 5. The surface treating agent according to 4 above, wherein in the general formula (7), the ratio b / c is in the range of 0.1-20.
6). 6. The surface treating agent according to any one of 1 to 5 above, wherein the compound (A) has a number average molecular weight of 240 to 10,000.
7. Furthermore, the surface treating agent as described in any one of said 1 thru | or 6 containing the compound (B) represented by the following general formula (11).

[Wherein R ¹¹ , R ¹² and R ¹³ are each independently a hydrogen atom, alkyl group, aralkyl group, cycloalkyl group, cycloaralkyl group or aryl group, and R ¹⁴ and R ¹⁵ are independently A hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, a trimethylsilyl group, a dimethylsilyl group, or a saturated or unsaturated heterocycloalkyl group, and R ¹⁴ and R ¹⁵ are bonded to each other. Or a saturated or unsaturated heterocycloalkyl group having a nitrogen atom. ]
8). 8. The surface treating agent according to 7 above, wherein the compound (B) is at least one of N, N-diethylaminotrimethylsilane and N, N-dimethylaminotrimethylsilane.
9. Furthermore, the surface treating agent as described in any one of said 1 thru | or 8 containing an organic solvent.
10. 10. The surface treatment agent according to any one of 1 to 9 above, which is used for water repellency on the surface of an object to be treated.
11. A surface treatment method for making a surface of a treatment object water-repellent, comprising a contact step of bringing the surface treatment agent according to any one of 1 to 9 into contact with the treatment object. Method.
12 12. The surface treatment method according to 11 above, wherein the object to be treated is a semiconductor substrate.
13. 13. The surface treatment method according to 11 or 12 above, wherein the object to be treated contains silicon nitride on a part of its surface.
14 14. The surface treatment method according to any one of 11 to 13, wherein the object to be treated includes silicon oxide on a part of the surface thereof.
15. The surface treatment method according to any one of the above 11 to 14, wherein the object to be treated contains metallic silicon in a part of its surface.
16. The surface treatment method according to any one of 11 to 15, further comprising an acid contact step in which an acidic liquid containing an acid is brought into contact with the object to be processed before the contact step.
17. 17. The surface treatment method according to 16 above, wherein the acid is an inorganic acid having an acid dissociation constant (pKa) of less than 0.
18. The object to be processed has a silicon nitride film and a silicon oxide film on the surface thereof, and after the contact step, the contact angle (Can) of water on the surface of the silicon nitride film and the surface of the silicon oxide film 18. The surface treatment method according to 17 above, wherein the ratio (Can / Cao) to the water contact angle (Cao) is in the range of 0.7 to 1.3.
19. The surface treatment according to any one of 11 to 15, further comprising a solvent replacement step after the step of contacting with the liquid containing water, and then bringing the surface treatment agent diluted with an organic solvent into contact with the object to be treated. Method.
20. In a surface treatment method for making a surface of a semiconductor substrate water repellent, a first step of bringing an acid liquid containing an acid into contact with the semiconductor substrate, and a surface treatment agent containing a compound represented by the following general formula (11): A surface treatment method comprising sequentially providing a second step of contacting the semiconductor substrate.

[Wherein R ¹¹ , R ¹² and R ¹³ are each independently a hydrogen atom, alkyl group, aralkyl group, cycloalkyl group, cycloaralkyl group or aryl group, and R ¹⁴ and R ¹⁵ are independently A hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, a trimethylsilyl group, a dimethylsilyl group, or a saturated or unsaturated heterocycloalkyl group, and R ¹⁴ and R ¹⁵ are bonded to each other. Or a saturated or unsaturated heterocycloalkyl group having a nitrogen atom. ]
21. 21. The surface treatment method as described in 20 above, wherein the acid is an inorganic acid having an acid dissociation constant (pKa) of less than 0.
22. 22. The method for treating a surface of a semiconductor substrate according to 20 or 21, wherein the semiconductor substrate has silicon nitride on at least a part of its surface.
23. 23. The surface treatment method for a semiconductor substrate as described in 22 above, wherein the semiconductor substrate has at least two portions of metal silicon, silicon nitride and silicon oxide on at least a part of the surface thereof.
24. The semiconductor substrate has a silicon nitride film and a silicon oxide film on its surface, and after the second step, the contact angle (Can) of water on the surface of the silicon nitride film and the surface of the silicon oxide film 24. The method for surface treatment of a semiconductor substrate according to any one of 20 to 23, wherein the ratio (Can / Cao) to the contact angle (Cao) of water is in the range of 0.7 to 1.3.

According to the surface treating agent of the present invention, it is possible to improve the water repellency by forming a film on the surface of an object to be treated such as a substrate used for a liquid crystal or a semiconductor. It is known that the surface of a water-repellent semiconductor substrate or the like has good adhesion to a resist resin, and it is known that the problem of so-called pattern collapse does not occur. The surface treatment agent of the present invention improves the yield of semiconductor manufacturing. Can be expected to do. Furthermore, according to the surface treating agent of the present invention, the surface of the substrate having different surface materials and states can be made water repellent to the same extent, so that the yield is particularly high in a semiconductor substrate or the like in which patterns made of different materials are mixed. The improvement effect can be expected.

In the following description, the contact angle is a value measured using water by a method according to JIS R1257.

The surface treating agent of the present invention contains a compound (A) represented by the following general formula (1), and if necessary, contains other silicone compounds, organic solvents, additives and the like.

[Wherein R ⁶ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom, a cyanoalkyl group, , An alkyl group, an aralkyl group, a cycloalkyl group, a cycloaralkyl group or an aryl group, and at least one of R ¹ , R ² , R ³ , R ⁴ and R ⁵ is a hydrogen atom. a, w, x, y and z are each independently 0 or a positive number, at least one of w and x is a positive number, 0 ≦ w / (x + y) ≦ 5, 0 ≦ z / (a + w + x + y) ≦ 1. Compound A may contain only 1 type of each structural unit, and may contain 2 or more types. ]

The said compound (A) is a silicon compound containing the structural unit shown below as represented by the said General formula (1).

In addition, the content rate of each structural unit is based on prescription | regulation of a, w, x, y, and z, In this invention, the said compound (A) may not contain all the structural units.

The compound (A) represented by the general formula (1) is a kind of polysiloxane in which structural units represented by (SiO _4/2 ) and the like are bonded to each other through a siloxane bond, The bonding form of the structural units may not necessarily be the arrangement order of the general formula (1). a, w, x, y, z represent the composition ratio (molar ratio) of each structural unit.

In the general formula (1), since any ^one of R ¹ , R ² , R ³ , R ⁴ and R ⁵ is a hydrogen atom, the compound (A) has an Si—H bond having chemical reactivity. Will be included. Si—H bonds are sometimes referred to as Si—H groups or hydrosilyl groups.

The number average molecular weight (Mn) of the compound (A) represented by the general formula (1) is preferably 120 or more and 20000 or less, more preferably 200 or more and 10,000 or less, and further preferably 240 or more and 10,000 or less. When a surface treating agent containing the compound (A) having Mn in the above range is used, a highly water-repellent film can be formed, and in particular, a water-repellent film can be efficiently formed even on fine uneven surfaces. .

In the general formula (1), when R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group or an aryl group, a preferred compound (A) is a compound represented by the following general formulas (2) to (6) from the viewpoint of water repellency, and more preferred compounds are represented by the general formulas (3) and (4), and particularly preferred compounds. Is represented by the general formula (4). The compound represented by the general formula (3) has a trifunctional structural unit having both a Si—O bond and a Si—H bond, and the compound represented by the general formula (4) includes two Si— It has a structural unit having both an O bond and a Si—H bond.

[Wherein R ² , R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group or an aryl group, and R ⁶ is a hydrogen atom or a carbon atom number of 1 to 6 Wherein x and y are positive numbers, z is 0 or a positive number, and the ratio of x / y is preferably 0.5 to 2000, more preferably 1 to 200. ]

[Wherein, R ⁵ independently of one another represents a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group or an aryl group, R ⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, w and y are positive numbers, z is 0 or a positive number, and the ratio of w / y is preferably 0.3 to 5.0. ]

[Wherein, R ³ and R ⁵ are each independently a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group or an aryl group, and R ⁶ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Where w, x and y are positive numbers and z is 0 or a positive number. ]

[In the formula, R ⁵ independently of one another represents a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group or an aryl group, and a and y are positive numbers, preferably a = y = 8. is there. ]

[Wherein, R ² and R ³ each independently represent a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group, a cycloaralkyl group or an aryl group. ]

In the above general formula (4), the preferable relationship between w, x, y and z is that x is preferably 0.1 to 0.9, more preferably 0.2 to 0.5 and w are preferably 0.05 to 0.5, more preferably 0.1 to 0.4, and y is preferably 0.05 to 0.5, more preferably 0.1 to 0.00. 4, z is preferably 0.001 to 0.2, more preferably 0.005 to 0.1.

In the present invention, the compound (A) in which at least one of R ¹ , R ² , R ³ , R ⁴ and R ^{5 in} the general formula (1) is a cyanoalkyl group is also a preferred embodiment, and particularly preferably at least R A compound in which ¹ is a cyanoalkyl group. In addition, a compound in which two or more of R ¹ , R ² , R ³ , R ⁴ and R ⁵ are cyanoalkyl groups may be used, and preferred examples in that case include, for example, R ¹ and R ⁵ . A compound having a cyanoalkyl group.
The cyanoalkyl group is represented by NC—R ⁷ —. R ⁷ is a linear or branched divalent alkyl group having 1 to 5 carbon atoms. R ⁷ preferably has 1 to 3 carbon atoms. Specific examples of the cyanoalkyl group include a cyanomethyl group, a cyanoethyl group, a cyanopropyl group, and the like. In the present invention, a cyanoethyl group or a cyanopropyl group is more preferable, and a cyanoethyl group is particularly preferable.

Regarding the constituent ratio of each structural unit when at least one of R ¹ , R ² , R ³ , R ⁴ and R ^{5 in} the general formula (1) is a cyanoalkyl group, The ratio of x / y is preferably 0.1 to 200, more preferably 0.5 to 20. The ratio of w / y when w and y are not 0 is preferably 0.3 to 5.0.

Of the compounds (A) having the cyanoalkyl group, a preferred compound is represented by the following general formula (7).

Wherein, B is cyanoalkyl ^{^{group, R 2, R 3, R}} 4 and R ^5, independently of one another, a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group or an aryl group, R ⁶ Is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, b, x, y and z are each independently 0 or a positive number, and c is a positive number. ]

(H—SiO _3/2 ) _b (B—SiO _3/2 ) _c in the general formula (7) is included in (R ¹ —SiO _3/2 ) _w in the general formula (1). That is, (b + c) = w. The higher the molar ratio of b to c (b / c), the higher the water repellency. However, from the viewpoint of a preferable balance of water repellency, it is preferably 20 to 0.1, more preferably 10 to 0.2, Particularly preferred is between 5 and 0.5.

Among the compounds represented by the general formula (7), a more preferable compound can be represented by the following general formula (8).

[Wherein, B is a cyanoalkyl group, R ³ and R ⁵ are each independently an alkyl group, an aralkyl group, a cycloalkyl group or an aryl group, and R ⁶ is a hydrogen atom or a carbon atom of 1 -6 alkyl groups, b, x, y and z are independently of each other 0 or a positive number, and c is a positive number. ]

The compound represented by the general formula (8) is also a kind of polysiloxane.

Other examples of the compound represented by the general formula (1) and having a cyanoalkyl group are represented by the following general formulas (9) and (10).

[Wherein R ² , R ⁴ and R ⁵ are each independently a hydrogen atom, a cyanoalkyl group, an alkyl group, an aralkyl group, a cycloalkyl group or an aryl group, and R ² , R ⁴ and R ⁵ are At least one of them is a cyanoalkyl group, R ⁶ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, x and y are positive numbers, and z is 0 or a positive number. X / y ratio is preferably 0.1 to 200, more preferably 0.5 to 20. ]

[In the formula, one R ⁵ is a cyanoalkyl group, and the other R ⁵ is independently a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group or an aryl group, and R ⁶ is a hydrogen atom. An atom or an alkyl group having 1 to 6 carbon atoms, w and y are positive numbers, z is 0 or a positive number, and the ratio of w / y is preferably 0.3 to 5.0. More preferably, it is 0.8 to 4.0. ]

Although the manufacturing method of the said compound (A) is not specifically limited, The method of using for the raw material organosilicon compound which forms each structural unit to hydrolytic condensation on acidic conditions is common.
When forming the structural unit (i), tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrachlorosilane, or the like can be used as a raw material organic silicon compound.
When the structural unit (ii) is formed, trimethoxysilane, triethoxysilane, tripropoxysilane, trichlorosilane, cyanopropyltrimethoxysilane, cyanoethyltriethoxysilane, or the like can be used as the raw material organic silicon compound. .
When forming the structural unit (iii), dimethoxymethylsilane, diethoxymethylsilane, dipropoxymethylsilane, dichloromethylsilane, or the like can be used as a raw material organic silicon compound.
In the case of forming the structural unit (iv), methoxytrimethylsilane, chlorotrimethylsilane, trimethylsilanol, hexamethyldisiloxane, tetramethyldisiloxane, or the like can be used as a raw material organic silicon compound.
In forming the structural unit (v), methanol, ethanol, propanol, s-butanol, or the like can be used.

The surface treating agent of the present invention may contain only one kind of the above compound (A), or may contain two or more kinds. For example, you may combine the compound represented by the said General formula (4), and the compound represented by the said General formula (7).

The surface treating agent of the present invention contains the compound (A) represented by the general formula (1) and may be composed only of the compound (A), or the compound (A) and other repellent materials. It may consist of a hydrating agent. As another water repellent, a compound represented by the following general formula (11) (hereinafter referred to as “compound (B)”) is preferable.

[Wherein R ¹¹ , R ¹² and R ¹³ are each independently a hydrogen atom, alkyl group, aralkyl group, cycloalkyl group, cycloaralkyl group or aryl group, and R ¹⁴ and R ¹⁵ are independently A hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, a trimethylsilyl group, a dimethylsilyl group, or a saturated or unsaturated heterocycloalkyl group, and R ¹⁴ and R ¹⁵ are bonded to each other. Or a saturated or unsaturated heterocycloalkyl group having a nitrogen atom. ]

Examples of the compound (B) include N, N-dimethylaminotrimethylsilane (hereinafter abbreviated as “DMATMS”), N, N-dimethylaminotriethylsilane, N, N-diphenylaminotriethylsilane, N, N-diethylaminotrimethyl. Silane, t-butylaminotrimethylsilane, allylaminotrimethylsilane, trimethylsilylacetamide, trimethylsilylpiperidine, trimethylsilylimidazole, trimethylsilylpyrrolidine, hexamethyldisilazane, N-methylhexamethyldisilazane, 1,2-di-N-octyl Examples thereof include tetramethyldisilazane, 1,2-divinyltetramethyldisilazane, heptamethyldisilazane, nonamethyltrisilazane, and tris (dimethylsilyl) amine. These compounds may be used alone or in combination of two or more.

When the surface treating agent of the present invention contains the compound (B), the content ratio of the compound (A) and the compound (B) is not limited. When the sum total of a compound (A) and a compound (B) is 100 mass%, the ratio of a compound (B) becomes like this. Preferably it is less than 60 mass%, More preferably, it is 1 to 40 mass%.

The surface treatment agent of the present invention may further contain an organic solvent and additives (pH adjuster, leveling agent, surfactant, silane coupling agent, stabilizer, etc.). As the organic solvent, a solvent that dissolves the compound (A) or a solvent that does not dissolve the compound (A) but disperses the compound (A) and additives can be used. In the present invention, a compound capable of dissolving the compound (A) is preferable because a surface treatment agent having a more uniform concentration distribution can be obtained. Moreover, a conventionally well-known solvent with little damage with respect to the to-be-processed object, especially the resin pattern formed in the organic liquid crystal or the board | substrate of a semiconductor or the to-be-etched pattern surface can be used. Specifically, sulfoxides such as dimethylsulfoxide; sulfones such as dimethylsulfone, diethylsulfone, bis (2-hydroxyethyl) sulfone, tetramethylenesulfone; N, N-dimethylformamide, N-methylformamide, N, N Amides such as dimethylacetamide, N-methylacetamide, N, N-diethylacetamide; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-hydroxymethyl-2 -Lactams such as pyrrolidone and N-hydroxyethyl-2-pyrrolidone; 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-diisopropyl-2-imidazolidi Non-imidazolidinones such as non-dimethyl ether, diethyl ether Dialkyl ethers such as tellurium, methyl ethyl ether, dipropyl ether, diisopropyl ether and dibutyl ether; dialkyl glycol ethers such as dimethyl glycol, dimethyl diglycol, dimethyltriglycol, methylethyl diglycol and diethyl glycol; propylene glycol monomethyl ether Alkylene glycol monoalkyl ethers such as propylene glycol monomethyl ether acetate, esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone and 3-heptanone; p-menthane, diphenylmenthane, limonene, Terpenes such as terpinene, bornane, norbornane, pinane; linear, branched, or cyclic hydrocarbon solvents, aromatic Hydrocarbon solvents, and the like. These organic solvents may be used alone or in combination of two or more.

Of these organic solvents, those having a relatively small polarity and a small molecular weight are preferred. However, if the molecular weight is too small, the volatility is too high and handling becomes difficult. Accordingly, preferred organic solvents are linear or branched hydrocarbon solvents or terpene solvents having 6 to 12 carbon atoms, and specifically include n-hexane, n-heptane, n-octane. N-nonane, methyloctane, n-decane, n-undecane, n-dodecane and the like. Terpene solvents include p-menthane, o-menthane, m-menthan and other menthane, diphenylmenthane, limonene, α-terpinene, β-terpinene, γ-terpinene and other terpinenes, bornane, norbornane, pinane, α -Pinenes such as pinene and β-pinene, monoterpenes such as karan and longifolene, diterpenes such as abiethane, and the like. These organic solvents may be used alone or in combination of two or more. More preferred organic solvents are linear hydrocarbon solvents having 7 to 10 carbon atoms, menthane and pinane, particularly preferably hexane and octane.

When the surface treatment agent of the present invention contains an organic solvent, the concentration of the compound (A) or the concentration of the total amount of the compound (A) and other water repellent is relative to the total amount of the surface treatment agent. Preferably, it is 0.1 to 60%, more preferably 0.5 to 30%, more preferably 1 to 20%.

As the substrate suitable for water repellency of the surface of the object to be processed using the surface treatment agent of the present invention, Si, SiO ₂ , SiON, SiN, p-Si, α-Si, W, W-Si, Al , Cu, Al—Si, Si—C, alumina, sapphire, glass, resin, and the like. Further, the substrate is not limited to the above-mentioned material, and the base surface has Si, SiO ₂ , SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si, alumina, Water repellency can be similarly applied to a laminated substrate film having a film made of sapphire, ITO, ZnO, glass or the like.

The above film is formed using a conventionally known technique such as CVD, vacuum vapor deposition, plating, plating, or the like. For CVD, methods such as plasma CVD, thermal CVD, and photo-CVD are known, but a film formed by any method may be used. More specifically, as a method for producing a film of SiO ₂ , SiON, SiN, Si, etc., various types such as a low temperature film formation technique such as plasma and a method of epitaxial growth at high temperature are known. For example, it is well known that SiN is not necessarily a composition of Si ₃ N ₄ which is a stoichiometric value but an intermediate composition expressed as SiN _x . In the present invention, since any of the compositions has an effect, it is typically referred to as SiN (or silicon nitride).

In the present invention, a preferable object to be treated has a material having a contact angle of preferably 0 to 80 degrees, more preferably 5 to 60 degrees, and still more preferably 10 to 50 degrees on the surface. Particularly preferably, it is a semiconductor substrate using a silicon wafer, and a film or pattern of SiN, SiO ₂ , metal silicon (Si) or the like (including the case of having Si—OH) may be placed on the surface thereof, A resist resin film or its pattern may be placed thereon. The effect of the present invention is most remarkable in at least a part of the surface of the substrate on three kinds of materials such as SiN such as Si ₃ N ₄ and SiON, SiO ₂ , and Si such as amorphous silicon and crystalline silicon. Of these, a substrate having at least two types, more preferably a substrate having these three types of materials.

According to the surface treatment agent of the present invention, a high water-repellent film can be provided regardless of the material of the surface of the object to be treated. In the case of a silicon wafer having Si—OH on the surface, the Si—H bond in the compound (A) is such that the H atom is negative and the Si atom is positively polarized. In the —H bond, since the O atom is negative and the H atom is positively polarized, a hydrogen bond is generated here, and the compound (A) is oriented on the substrate surface to make the substrate surface water repellent. It is thought that the effect is given.

In particular, when the surface treatment agent of the present invention contains a compound (A) in which at least one of R ¹ , R ² , R ³ , R ⁴ and R ^{5 in} the general formula (1) is a cyanoalkyl group, A high water-repellent film can be provided for any of SiO ₂ , SiN, and Si. Further, when the compound (A) contains a cyanoalkyl group, the magnitude of the effect on each surface material can be controlled by the amount of the cyanoalkyl group and the amount of Si—H bond. That is, the ratio of the total amount of structural units having a cyanoalkyl group and the total amount of structural units having a Si—H bond is 1 to 20 mol% when the sum of both is 100 mol% and 99 to 80 mol%. In the case where one structural unit has both a cyanoalkyl group and an Si—H bond, the amount of the structural unit having a cyanoalkyl group focused on the cyanoalkyl group and an Si—H bond focused on the Si—H bond If the calculation is carried out with the total of both as the amount of structural units being 100 mol%, the above control can be made the same. By such control, the values of the contact angles on the surfaces of different materials of SiO ₂ , SiN, and Si can be made closer. The latest liquid crystal and semiconductor substrate surfaces have micropatterns of various surface materials such as SiO ₂ , SiN, Si, etc., so that not only can the substrate surface be made water-repellent, but the same level on the surface of different materials The ability to impart the water repellency is an extremely advantageous effect in solving the problem of pattern collapse on the substrate surface of a semiconductor or the like having a complicated pattern. Such an effect has not been conventionally known.

The surface treatment method of the present invention includes a contact step of bringing the surface treatment agent of the present invention into contact with the surface of an object to be processed.
Although the specific method of a contact process is not specifically limited, The method of apply | coating a surface treating agent is simple. The coating may be any method such as spray coating, spin coating or dipping, but spin coating is preferred from the viewpoint that a thin and uniform water-repellent film can be obtained. Moreover, what contains an organic solvent is preferably used for a surface treating agent.

When the surface treatment agent of the present invention contains the compound (A) and the compound (B), it is preferable to use them in a mixed state from the viewpoint of the uniformity of the thickness of the coating film. Either one of the compound (A) and the compound (B) is first brought into contact with the surface of the semiconductor substrate and then brought into contact with the other, or both the compound (A) and the compound (B) are supplied from separate supply ports. At the same time, a method of supplying the surface of the semiconductor substrate can be used.

In the present invention, the object to be processed is preferably a semiconductor substrate having a film made of at least one of SiO ₂ , SiN and Si on a part of its surface.
Prior to the contacting step, pretreatment such as cleaning and drying of the semiconductor substrate may be performed, and after the contacting step, post-processing such as washing and drying may be performed. However, considering the mechanism that causes pattern collapse due to the surface tension when the cleaning liquid used in the pretreatment dries, it is not preferable to have a drying step in the pretreatment, and it should be dried after cleaning with the pretreatment cleaning liquid. It is preferable to perform the contact step using the surface treatment agent of the present invention.

The cleaning method in the pretreatment step is not particularly limited, but for example, a method called “SC1 cleaning” using ammonia and hydrogen peroxide is known. Further, acid treatment of the surface (hereinafter referred to as “acid contact step”) may be performed before and after cleaning the semiconductor substrate.

Specifically, the acid contact step is to bring an acidic liquid containing acid into contact with the surface of the semiconductor substrate by a method such as coating, spraying, dipping, or vapor contact. In the present invention, the method of immersing the substrate in an aqueous acid solution is preferable because it can be carried out with a simple apparatus. The concentration of the acid when an aqueous solution is used as the acidic liquid is preferably 0.1% by mass or more and 96% by mass or less, more preferably 1% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 20% by mass or less. is there.
The condition for bringing the acidic liquid into contact with the surface of the semiconductor substrate is not particularly limited, but it is preferably about 1 second to 30 minutes, more preferably 10 seconds to 10 minutes at a temperature higher than 0 ° C. and lower than 70 ° C. Thus, effects such as impurity removal can be obtained.

The acid used in the acid contact step may be either an organic acid or an inorganic acid. In the case of an organic acid, an acid having an acid dissociation constant (pKa) of 2.0 or less, such as oxalic acid, trichloroacetic acid, trifluoroacetic acid, or dichloroacetic acid, is preferable, and oxalic acid is more preferable. In the case of an inorganic acid, an inorganic acid having an acid dissociation constant (pKa) of 0.0 or less is preferable. Specifically, hydrochloric acid, sulfuric acid, nitric acid, hydroiodic acid, hydrobromic acid, chloric acid, bromic acid, Examples thereof include iodic acid, permanganic acid, thiocyanic acid, perchloric acid, perbromic acid, tetrafluoroboric acid, hexafluorophosphoric acid and the like. Of these, hydrochloric acid, sulfuric acid, and nitric acid that are easily obtained industrially are preferable, and hydrochloric acid is particularly preferable because it is safe in that it is not oxidizable and hardly forms a hardly soluble salt. Among organic acids and inorganic acids, inorganic acids are preferred in that high purity products are easily obtained. These acids are preferably highly pure to the extent that they are commercially available. Moreover, in order to use for a semiconductor use, what is called EL grade except a particle can also be used preferably similarly.
Further, in the case of an acid having low water solubility such as oxalic acid, a solution using 2-propanol, methyl ethyl ketone or the like as an organic solvent can be used in the same manner as other acid aqueous solutions.

The compound (A) contained in the surface treatment agent of the present invention may be hydrolyzed by contact with water, and a preferable solvent in the case where the surface treatment agent contains an organic solvent is one having a relatively small polarity. Therefore, when water is used in the cleaning in the pretreatment process or the acid contact process after cleaning, the water and the surface between the cleaning process and the acid contact process, and between the acid contact process and the contact process. It is preferable to provide a step of replacing the medium remaining on the surface of the semiconductor substrate with an organic solvent such as alcohol having an intermediate polarity of the organic solvent contained in the treatment agent.

Also, after the contacting step, drying is usually performed, but if an excessive surface treatment agent remains on the surface of the semiconductor substrate, there is a possibility that spots are generated on the surface of the substrate. Therefore, after bringing a surface treatment agent containing an organic solvent having a relatively small polarity into contact with the surface of the semiconductor substrate, water having an intermediate polarity between the organic solvent contained in the surface treatment agent and an organic material such as alcohol It is preferable to perform a step of replacing the medium remaining on the surface of the semiconductor substrate using a solvent, and then wash with water. On the substrate surface that has been made water-repellent by the surface treatment agent of the present invention, even after the above replacement step and cleaning step, the excellent water repellency is maintained, and even after the drying step, pattern collapse is suppressed. be able to. In the subsequent semiconductor manufacturing process, when the surface of the substrate is made hydrophilic, treatments such as dry ashing, ozone oxidation treatment, and wet oxidation can be performed.

As a specific method for treating the substrate surface using the surface treating agent of the present invention as one embodiment of the surface treating method of the present invention, the substrate is washed by a washing method using deionized water, then washed with water, and alcohol. As a contact process with the surface treatment agent, the surface treatment agent diluted with a low-polarity solvent is brought into contact with the substrate, then the solvent is replaced with alcohol, washed with deionized water, and dried. Can be mentioned.

As another embodiment of the surface treatment method of the present invention, as a specific method of treating the substrate surface using the surface treatment agent of the present invention, the substrate is cleaned by a cleaning method using deionized water, and then the acid is added. Immerse in the aqueous solution containing, wash with water, perform solvent replacement with alcohol, as a contact process with the surface treatment agent, contact the surface treatment agent diluted with a low polarity solvent to the substrate, and then after solvent replacement with alcohol, A series of steps of washing with deionized water and then drying can be mentioned.

In the surface treatment method of the present invention, when the surface treatment agent is mainly the compound (A), the main constituent material of the formed water-repellent film is the compound (A) itself or the compound (A). Is a silicon compound obtained by a reaction between a functional group contained in the substrate and a functional group contained in the material constituting the surface of the workpiece. The contact angle in this water-repellent coating is preferably 80 to 120 degrees, more preferably 85 to 95 degrees.
In the surface treatment method of the present invention, when the surface treatment agent contains the compounds (A) and (B), the main constituent material of the formed water-repellent film is the compound (A) and the compound (B) itself. A silicon compound formed by condensation of the compound (A) and the compound (B), or a functional group contained in the compound (A) and / or a functional group contained in the compound (B), and an object to be treated It is a silicon compound obtained by the reaction with the functional group contained in the material constituting the surface of The contact angle in this water-repellent coating is preferably 80 to 120 degrees, more preferably 85 to 95 degrees.

When the object to be processed is a silicon wafer (semiconductor substrate) having a silicon nitride film and a silicon oxide film on its surface, a contact angle (Can) on the surface of the silicon nitride film after the contact step. And the contact angle (Cao) at the surface of the silicon oxide film (Can / Cao) is preferably in the range of 0.7 to 1.3, more preferably 0.9 to 1.1, particularly preferably 0. 97 to 1.03.

Another aspect of the present invention is a surface treatment method for imparting water repellency to the surface of a semiconductor substrate, which is represented by a first step in which an acidic liquid containing an acid is brought into contact with the semiconductor substrate, and the following general formula (11): A surface treatment method comprising sequentially providing a second step of bringing a surface treatment agent containing a compound (B) into contact with the semiconductor substrate. The semiconductor substrate means a silicon wafer having a material with a contact angle of preferably 0 to 80 degrees, more preferably 5 to 60 degrees, and still more preferably 10 to 50 degrees on the surface, and SiN, A film or pattern of SiO ₂ , (Si) or the like (including the case of having Si—OH) may be placed, or a resist resin film or pattern thereof may be placed.

The substrate surface can be cleaned before the step of bringing the acidic liquid into contact with the semiconductor substrate surface, which is the first step. As a cleaning method, for example, a method called “SC1 cleaning” using ammonia and hydrogen peroxide and a method called “SC2 cleaning” using hydrochloric acid and hydrogen peroxide are known, and any known cleaning method can be used. Can be used. However, for example, a cleaning method using a mixture of hydrofluoric acid and nitric acid obviously erodes the semiconductor substrate surface, and it goes without saying that it is not preferable to apply it to the surface after the pattern is formed. .

In addition, since the SC1 cleaning solution is alkaline, it is preferable to perform a water washing step in the present invention before performing the step of bringing the acidic liquid into contact with the semiconductor substrate surface. Similarly, it is preferable to perform water washing after SC2 washing. The acidic liquid used in the present invention and the cleaning liquid in which hydrochloric acid and hydrogen peroxide used in SC2 cleaning coexist are different in the presence or absence of hydrogen peroxide, and even if SC2 cleaning is performed instead of the step of contacting the acidic liquid, There is no effect.

In addition, the compound (B) used in the second step may be hydrolyzed, and a preferable solvent when the surface treatment agent is used after being diluted with a solvent is relatively small in polarity. After that, it is preferable to carry out water washing, and further sandwich a step of solvent replacement using a solvent such as alcohol having an intermediate polarity between water and the solvent used in the second step.

In the second step, the method of bringing the surface treatment agent into contact with the substrate is not particularly limited, but the method of applying the surface treatment agent is simple. Coating may be any method such as spray coating, spin coating or dipping, but spin coating is preferred in that a thin and uniform treated film can be obtained. Further, the surface treatment agent is preferably diluted with a solvent.

Before the surface treatment, pretreatment such as cleaning and drying of the substrate may be performed, and after the surface treatment, posttreatment such as washing and drying may be performed, but the surface tension when the cleaning liquid dries. In view of the mechanism that causes pattern collapse, it is not preferable to put a drying step in the pretreatment, and it is preferable to perform the surface treatment using the surface treatment agent used in the present invention without drying after washing with the washing liquid.

In addition, after the step of contacting with the surface treatment agent, a drying step is usually included, and it is an effect of the present invention that pattern collapse does not occur in the drying step, but an excessive surface treatment agent is present before the drying step. If a large amount remains, it may cause spots on the substrate surface. Therefore, it is preferable that the surface treatment agent diluted with a solvent having a relatively small polarity is brought into contact with the substrate surface, and then the surface treatment with water is performed. It is preferable to wash with water with a step of solvent replacement using a solvent such as alcohol having an intermediate polarity of the solvent used in step 1. The substrate surface that has been subjected to the surface treatment of the present invention can maintain water repellency even after the above-described solvent replacement or cleaning, and pattern collapse can be suppressed even after drying. In a subsequent semiconductor manufacturing process, when it is desired to make the substrate surface hydrophilic, a process such as dry ashing, ozone oxidation, or wet oxidation can be performed.

As a specific method for treating the surface of a semiconductor substrate as one embodiment of the present invention, the substrate is washed by a washing method using deionized water, and then immersed in an aqueous solution containing an acidic liquid (first step) and washed with water. The solvent was replaced with alcohol, and as a contact step (second step) with the surface treatment agent containing compound (B), the surface treatment agent diluted with a low-polar solvent was brought into contact with the substrate, and then the solvent with alcohol was used. Subsequently, a series of steps of washing with deionized water and then drying can be mentioned.

As cleaning methods for silicon wafers, methods using hydrofluoric acid / nitric acid, hydrochloric acid / hydrogen peroxide, etc. are known, but these methods are more effective than those that have the effect of leaching oxide films and metals on the substrate surface. The meaning of using an acid in the invention is completely different. It is known that acidic Si—OH groups exist on the substrate surface, and conventionally known silylating agents have been said to react with the Si—OH groups on the surface to make the surface water repellent. The fact that this effect does not sufficiently appear on the silicon surface is as disclosed in Patent Document 3. The present inventors consider that the reason why the effect does not appear on the silicon nitride surface is that there is a basic functional group on the substrate surface, and in order to change the substrate surface to acidic, hydrogen peroxide is allowed to coexist. When the surface treatment was performed with a surface treatment agent containing a specific water repellent, the present invention was completed by finding an excellent effect.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to this embodiment.

The number average molecular weight of the polysiloxane such as the compound (A) according to the present invention was measured by a high-speed GPC system “HLC-8320GPC” (model name) manufactured by Tosoh Corporation as a GPC apparatus. The column used was “TSKgel G4000H _XL ” and “TSKgel G2000H _XL ” manufactured by Tosoh Corporation.
The viscosity of the polysiloxane was measured with an E-type viscometer.

Other compounds used for the preparation of the surface treatment agent are shown below.
(1) DMATMS
N, N-dimethylaminotrimethylsilane manufactured by Tokyo Chemical Industry Co., Ltd.
(2) HMDS
It is 1,1,1,3,3,3-hexamethyldisilazane manufactured by Kishida Chemical Co., Ltd.
(3) TMCT
It is 2,4,6,8-tetramethylcyclotetrasiloxane manufactured by Alpha Eiser.
(4) OMCT
Octamethylcyclotetrasiloxane manufactured by Tokyo Chemical Industry Co., Ltd., a compound having no Si—H bond.
(5) KF-96
This is a dimethyl silicone oil “KF-96-30cs” (trade name) manufactured by Shin-Etsu Silicone Co., which is a compound having no Si—H bond with z of 0 in the general formula (1).
(6) KF-99
This is a hydrogen silicone oil “KF-99” (trade name) manufactured by Shin-Etsu Silicone Co., which is a compound in which a, w and z in the general formula (1) are all 0.
(7) Q-2
Mayerials Inc. This is octa (hydrodimethylsiloxy) silsesquioxane manufactured by the company.
(8) n-octane

Synthesis Example 1-1
The manufacturing method of the compound (A) based on this invention is described.
A 300 ml four-necked flask was equipped with a magnetic rotor, a liquid feed pump, a reflux condenser and a thermometer, and the system was replaced with nitrogen gas. To this flask, 8.21 g (50 mmol) of triethoxysilane, 10.87 g (50 mmol) of 2-cyanoethyltriethoxysilane, 10.62 g (100 mmol) of dimethoxymethylsilane, 1,1,3,3-tetramethyldisiloxane 20 .15 g (150 mmol), 2-butanol 24.71 g and xylene 74.12 g were accommodated, and the reaction system was put in a nitrogen gas atmosphere. The temperature in the flask was kept at 25 ° C., and a mixture of 9.30 g of a 3.14% hydrochloric acid aqueous solution and 12.35 g of 2-butanol was gradually added from the dropping funnel while stirring. After completion of dropping, the reaction solution was allowed to stand at 25 ° C. for 22 hours.

Next, the reaction solution was placed in a distillation apparatus, and while the pressure was reduced to an ultimate pressure of 133 Pa, the temperature of the reaction solution was increased from 16 ° C. to 60 ° C., and volatile components including water were distilled off under reduced pressure. As a result, 21.4 g of a colorless liquid (hereinafter referred to as “polysiloxane (PCN1)”) was obtained. With respect to this polysiloxane (PCN1), the number average molecular weight (Mn) was measured by GPC and found to be 600. Moreover, it was 7 mPa * s when the viscosity in 25 degreeC was measured.

The composition of polysiloxane (PCN1) is shown in the following structural formula (12) together with the molar ratio of structural units.

(CN represents a cyano group, Me represents a methyl group, s-Bu represents a secondary butyl group, and Et represents an ethyl group.)

The composition was subjected to ¹ H-NMR (proton nuclear magnetic resonance) and ²⁹ Si-NMR measurements using polysiloxane (PCN1) as a CDCl ₃ (deuterated chloroform) solvent, and analyzed from the obtained chemical shift. That is, a signal having a chemical shift δ (ppm) in the ¹ H-NMR spectrum of 2.2 to 2.5 is derived from (CH ₂ CH ₂ CN), and δ (ppm) is 3.6 to 3.8. signal, (OCH ₂ CH _3), the signal [delta] (ppm) is 3.8-4.1, from _{_{(OCH (CH 3) CH 2}} CH 3). Further, from the ²⁹ Si-NMR spectrum, the signal with δ (ppm) of −10 to 0 is derived from the structure of SiO _1/2 , and the signal with δ (ppm) of −40 to −35 is SiO _2/2 Derived from the structure. A raw material compound giving a structure having three Si—O— bonds expressed as SiO _1.5 or SiO _3/2 (called T monomer), and Si—O expressed as SiO _1.0 or SiO _2/2 -It has been found that for raw material compounds (called D monomers) that give a structure having two bonds, the raw material compounds charged in the condensation reaction are incorporated into the polysiloxane in a proportion of the amount used. Therefore, simultaneous equations relating to the side chains were prepared from the integrated values of the signal intensities, and the molar ratio of each structural unit contained in the polysiloxane (PCN1) was determined from the charged amount of each monomer and the integrated value of NMR. .

Synthesis Example 1-2
A 300 ml four-necked flask was equipped with a magnetic rotor, a liquid feed pump, a reflux condenser and a thermometer, and the system was replaced with nitrogen gas. To this flask, 12.32 g (75 mmol) of triethoxysilane, 5.43 g (25 mmol) of 2-cyanoethyltriethoxysilane, 10.62 g (100 mmol) of dimethoxymethylsilane, 1,1,3,3-tetramethyldisiloxane 20 .15 g (150 mmol), 2-butanol 24.71 g and xylene 74.12 g were accommodated, and the reaction system was put in a nitrogen gas atmosphere. The temperature in the flask was kept at 25 ° C., and a mixture of 9.30 g of a 3.14% hydrochloric acid aqueous solution and 12.35 g of 2-butanol was gradually added from the dropping funnel while stirring. After completion of dropping, the reaction solution was allowed to stand at 25 ° C. for 22 hours.

Next, the reaction solution was placed in a distillation apparatus, and with the pressure reduced to an ultimate pressure of 133 Pa, the temperature of the reaction solution was increased from 17 ° C. to 60 ° C. to distill off volatile components including water under reduced pressure. As a result, 23.97 g of a colorless liquid (hereinafter referred to as “polysiloxane (PCN2)”) was obtained. This polysiloxane (PCN2) was measured to have a number average molecular weight (Mn) of 730 by GPC. Moreover, it was 6 mPa * s when the viscosity in 25 degreeC was measured.

The composition of polysiloxane (PCN2) is shown in the following structural formula (13) together with the molar ratio of structural units.

Synthesis Example 1-3
A 300 ml four-necked flask was equipped with a magnetic rotor, a liquid feed pump, a reflux condenser and a thermometer, and the system was replaced with nitrogen gas. This flask was charged with 32.85 g (200 mmol) of triethoxysilane, 20.15 g (150 mmol) of 1,1,3,3-tetramethyldisiloxane, 24.04 g of 2-propanol and 72.12 g of xylene. Was put in a nitrogen gas atmosphere. The temperature in the flask was kept at 25 ° C., and a mixed solution of 2.63% hydrochloric acid aqueous solution (11.10 g) and 2-propanol (12.02 g) was gradually added from the dropping funnel. After completion of dropping, the reaction solution was allowed to stand at 25 ° C. for 22 hours.

Next, the reaction solution was placed in a distillation apparatus, and with the pressure reduced to an ultimate pressure of 1 mmHg, the temperature of the reaction solution was increased from 9 ° C. to 60 ° C. to distill off volatile components including water under reduced pressure. As a result, 19.3 g of a colorless liquid (hereinafter referred to as “polysiloxane (P1)”) was obtained. The number average molecular weight (Mn) of this polysiloxane (P1) measured by GPC was 1,050. Moreover, it was 7 mPa * s when the viscosity in 25 degreeC was measured.

The composition of polysiloxane (P1) is shown in the following structural formula (14) together with the molar ratio of structural units.

(Me represents a methyl group, i-Pr represents an isopropyl group, and Et represents an ethyl group.)

The composition was subjected to ¹ H-NMR (proton nuclear magnetic resonance) measurement using polysiloxane (P1) as a CDCl ₃ (deuterated chloroform) solvent and analyzed from the obtained chemical shift. That is, a signal with a chemical shift δ (ppm) of −0.2 to 0.6 in the ¹ H-NMR spectrum is a signal with a δ (ppm) of 0.9 to 1.5 based on the structure of Si—CH _3. Is (OCH (CH ₃ ) ₂ and OCH ₂ CH ₃ ), and a signal with δ (ppm) of 3.5 to 4.1 is OCH ₂ CH ₃ and δ (ppm) of 4.1 to 5.5. Is considered to be based on OCH (CH ₃ ) ₂ and Si—H. A raw material compound giving a structure having three Si—O— bonds represented by SiO _1.5 or SiO _3/2 (called T monomer), and Si—O represented by SiO _1.0 or SiO _2/2 -It has been found that for raw material compounds (called D monomers) that give a structure having two bonds, the raw material compounds charged in the condensation reaction are incorporated into the polysiloxane in a proportion of the amount used. Therefore, simultaneous equations related to the side chains were prepared from the integrated values of the signal intensities, and the molar ratio of each structural unit contained in the polysiloxane (P1) was determined from the charged amount of each monomer and the integrated value of NMR. .

Synthesis Example 1-4
A 300 ml four-necked flask was equipped with a magnetic rotor, a liquid feed pump, a reflux condenser and a thermometer, and the system was replaced with nitrogen gas. To this flask, 16.43 g (100 mmol) of triethoxysilane, 10.62 g (100 mmol) of dimethoxymethylsilane, 20.15 g (150 mmol) of 1,1,3,3-tetramethyldisiloxane, 20.03 g of 2-propanol and 60.10 g of xylene was accommodated, and the reaction system was placed in a nitrogen gas atmosphere. The temperature in the flask was kept at 25 ° C., and a mixture of 9.30 g of a 3.14% hydrochloric acid aqueous solution and 10.02 g of 2-propanol was stirred while gradually being added from the dropping funnel. After completion of dropping, the reaction solution was allowed to stand at 25 ° C. for 22 hours.

Next, the reaction solution was placed in a distillation apparatus, and while the pressure was reduced to an ultimate pressure of 133 Pa, the temperature of the reaction solution was increased from 7 ° C. to 60 ° C. to distill off volatile components including water under reduced pressure. As a result, 15.6 g of a colorless liquid (hereinafter referred to as “polysiloxane (P2)”) was obtained. The number average molecular weight (Mn) of this polysiloxane (P2) measured by GPC was 1,000. Moreover, it was 3 mPa * s when the viscosity in 25 degreeC was measured.

The composition of polysiloxane (P2) is shown in the following structural formula (15) together with the molar ratio of structural units.

(Me represents a methyl group, Et represents an ethyl group, and i-Pr represents an isopropyl group.)

The composition was subjected to ¹ H-NMR (proton nuclear magnetic resonance) measurement using polysiloxane (P2) as a CDCl ₃ (deuterated chloroform) solvent and analyzed from the obtained chemical shift. That is, a signal with a chemical shift δ (ppm) of −0.2 to 0.6 in the ¹ H-NMR spectrum is a signal with a δ (ppm) of 0.9 to 1.5 based on the structure of Si—CH _3. Is (OCH (CH ₃ ) ₂ and OCH ₂ CH ₃ ), and a signal with δ (ppm) of 3.5 to 4.1 is OCH ₂ CH ₃ and δ (ppm) of 4.1 to 5.5. Is considered to be based on OCH (CH ₃ ) ₂ and Si—H. In addition, as for the raw material compound (referred to as T monomer) which gives a structure having three Si—O— bonds represented by SiO _1.5 or SiO _3/2 , the charged raw material compound is almost in proportion to the amount used. It has been found to be incorporated into polysiloxanes. Therefore, simultaneous equations relating to the side chains were prepared from the integrated values of the signal intensities, and the molar ratio of each structural unit contained in the polysiloxane (P2) was determined from the charged amount of each monomer and the integrated value of NMR. .

Experimental Example 1-1
Mixing 2.0 parts by mass of polysiloxane (PCN2) obtained in Synthesis Example 1-2, 8.0 parts by mass of N, N-dimethylaminotrimethylsilane (DMATMS), and 90.0 parts by mass of n-octane Thus, a surface treatment agent was prepared (see Table 1). Using the chemical solution containing this surface treatment agent, the surface treatment of the object to be treated was performed. Table 2 shows specific methods of surface treatment. An object to be processed (hereinafter referred to as “substrate”) is a silicon wafer with a silicon nitride film (hereinafter sometimes referred to as “SiN substrate”) cut into a size of 10 mm × 50 mm, or a silicon wafer with a silicon oxide film (hereinafter referred to as “SiN substrate”). , “Sometimes referred to as“ SiO ₂ substrate ”) and silicon wafer (hereinafter sometimes referred to as“ Si substrate ”). The substrate is designated as No. 2 in Table 2. 1-1 to No. In the order of 1-12, after immersing each chemical solution (about 5 ml) weighed in a resin cup at a predetermined temperature for a predetermined time, nitrogen gas was blown for 20 seconds to remove water, and the contact angle was quickly Was measured. In the case where the object to be processed is a SiO ₂ substrate, No. is used so that the oxide film is not melted. In the treatment in 1-4, the immersion time of the 1% HF aqueous solution was 30 seconds.

The contact angle on the surface of the substrate after the surface treatment is determined by JIS R1257: 1999 static droplets in air using a dataphysics automatic contact angle measuring device “OCA20 type” for the substrate after drying by nitrogen gas blowing for 20 seconds. It is the average value measured five times by the method.

Table 1 shows standard deviations (calculated values) of contact angles on three types of substrate surfaces. The standard deviation is defined according to JIS Z8101-1. The standard deviation is defined as the positive square root of the dispersion of the three contact angle values on the surfaces of the SiN substrate, the SiO ₂ substrate and the Si substrate shown in Table 1. The closer this standard deviation value is to 0, the smaller the contact angle deviation due to the type of substrate.

Experimental Examples 1-2 to 1-12
The surface treatment agent shown in Table 1 was prepared, surface treatment was performed in the same manner as in Experimental Example 1-1, the contact angle on each substrate surface was measured, and the standard deviation was calculated. The results are shown in Table 1.

Experimental Example 1-13
This experimental example is No. 1 in Table 2. 1-1 to No. This is a blank test in which, in the order of 1-5, each chemical solution (about 5 ml) was immersed in a predetermined temperature at a predetermined temperature for a predetermined time, then nitrogen gas was blown for 20 seconds to remove water, and the contact angle was measured immediately. (See Table 1).

According to Experimental Examples 1-8 to 1-12 shown in Table 1, some of the SiN, SiO ₂ and Si substrates had a large contact angle, but the substrate with a large contact angle and a small contact angle. The difference with the substrate was large, and the standard deviation exceeded 2. On the other hand, in Experimental Examples 1-1 to 1-6 using a polysiloxane having a cyanoalkyl group, the difference in contact angle between the three types of substrate surfaces was smaller and the standard deviation was less than 1. It can be seen that the water-repellent film was formed without depending on the composition and showed water repellency. This means that when a plurality of patterns of different materials coexist on the surface, the difference in water repellency due to the surface treatment agent is small at each position. In the cleaning process, it is possible to prevent the stress based on the surface tension of the cleaning liquid from acting unevenly between patterns of different materials, and thus it can be said that excellent results have been shown.

Experimental example 2-1
A surface treating agent was prepared by mixing 5 parts by mass of KF-99 and 95 parts by mass of n-octane (see Table 3). Using the chemical solution containing this surface treatment agent, the surface treatment of the object to be treated was performed. The specific method of surface treatment is as shown in Table 2. The object to be processed is a silicon wafer with a SiN film (SiN substrate) having a size of 10 mm × 50 mm. The contact angle measurement method is also the same as in Experimental Example 1-1 and the like (see Table 3).

Experimental Example 2-2
10 parts by mass of KF-99 and 90 parts by mass of n-octane were mixed to prepare a surface treatment agent, and the surface treatment of the SiN substrate surface was performed in the same manner as in Experimental Example 2-1, and the substrate after the treatment The contact angle at the surface was measured. The results are shown in Table 3.

Experimental Example 2-3
A surface treating agent was prepared by mixing 5 parts by mass of the polysiloxane (P1) obtained in Synthesis Example 1-3 and 95 parts by mass of n-octane, and the surface of the SiN substrate in the same manner as in Experimental Example 2-1. The contact angle on the substrate surface after the treatment was measured. The results are shown in Table 3.

Experimental Examples 2-4 to 2-6
The surface treatment agent shown in Table 3 was prepared, the surface treatment of the SiN substrate surface was performed in the same manner as in Experimental Example 2-1, and the contact angle on the substrate surface after the treatment was measured. The results are shown in Table 3.

Experimental Example 2-7
The treatment was performed in the same manner as in Experimental Example 2-6 except that a SiO ₂ substrate was used instead of the SiN substrate, and the contact angle on the treated substrate surface was measured. The results are shown in Table 3. In the case of an SiO ₂ substrate, No. is used so that the oxide film does not melt. In the treatment in 1-4, the immersion time of the 1% HF aqueous solution was 30 seconds.

Experimental Example 2-8
The treatment was performed in the same manner as in Experimental Example 2-6, except that a Si substrate was used instead of the SiN substrate, and the contact angle on the treated substrate surface was measured. The results are shown in Table 3.

2-9 to 2-12
The surface treatment agent shown in Table 3 was prepared, the surface treatment of the SiN substrate surface was performed in the same manner as in Experimental Example 2-1, and the contact angle on the substrate surface after the treatment was measured. The results are shown in Table 3.

Experimental Example 2-13
The treatment was performed in the same manner as in Experimental Example 2-10 except that a SiO ₂ substrate was used instead of the SiN substrate, and the contact angle on the treated substrate surface was measured. The results are shown in Table 3. In the case of an SiO ₂ substrate, No. is used so that the oxide film does not melt. In the treatment in 1-4, the immersion time of the 1% HF aqueous solution was 30 seconds.

Experimental Example 2-14
The treatment was performed in the same manner as in Experimental Example 2-10 except that a Si substrate was used instead of the SiN substrate, and the contact angle on the treated substrate surface was measured. The results are shown in Table 3.

As is apparent from Table 3, Experimental Examples 2-9 to 2-14 are examples using a surface treating agent containing a compound containing no Si—H group, and show a low contact angle of less than 85 degrees. It was. On the other hand, Experimental Examples 2-1 to 2-8 are examples using a surface treating agent containing a compound containing a Si—H group, and the contact angle was 86 degrees or more, indicating good water repellency.

Experimental Example 3-1
A surface treating agent was prepared by mixing 1 part by mass of KF-99, 4 parts by mass of DMATMS, and 95 parts by mass of n-octane (see Table 4). Using the chemical solution containing this surface treatment agent, the surface treatment of the object to be treated was performed. The specific method of surface treatment is as shown in Table 2. The object to be processed is a silicon wafer with a SiN film (SiN substrate) having a size of 10 mm × 50 mm. The contact angle measurement method is also the same as in Experimental Example 1-1 and the like (see Table 4).

Experimental Examples 3-2 to 3-11
Surface treatment agents shown in Table 4 were prepared, and the surface treatment of the SiN substrate surface was performed in the same manner as in Experimental Example 3-1, and the contact angle on the substrate surface after the treatment was measured. The results are shown in Table 4.

Experimental Example 3-12
The treatment was performed in the same manner as in Experimental Example 3-4 except that a SiO ₂ substrate was used instead of the SiN substrate, and the contact angle on the treated substrate surface was measured. The results are shown in Table 4. In the case of an SiO ₂ substrate, No. is used so that the oxide film does not melt. In the treatment in 1-4, the immersion time of the 1% HF aqueous solution was 30 seconds.

Experimental Example 3-13
The treatment was performed in the same manner as in Experimental Example 3-4, except that a Si substrate was used instead of the SiN substrate, and the contact angle on the treated substrate surface was measured. The results are shown in Table 4.

Experimental Examples 3-14 to 3-20
Surface treatment agents shown in Table 4 were prepared, and the surface treatment of the SiN substrate surface was performed in the same manner as in Experimental Example 3-1, and the contact angle on the substrate surface after the treatment was measured. The results are shown in Table 4.

Experimental Example 3-21
The treatment was performed in the same manner as in Experimental Example 3-15 except that a SiO ₂ substrate was used instead of the SiN substrate, and the contact angle on the treated substrate surface was measured. The results are shown in Table 4. In the case of an SiO ₂ substrate, No. is used so that the oxide film does not melt. In the treatment in 1-4, the immersion time of the 1% HF aqueous solution was 30 seconds.

Experimental Example 3-22
The treatment was performed in the same manner as in Experimental Example 3-15 except that a Si substrate was used instead of the SiN substrate, and the contact angle on the substrate surface after the treatment was measured. The results are shown in Table 4.

In the following experiment, surface treatment agents 4-1 to 4-7 shown in Table 5 were prepared, and surface treatment was performed on the SiN substrate, the SiO ₂ substrate, and the Si substrate.

Experimental Example 4-1
Surface treatment of the object to be treated was performed using a chemical solution containing the individual surface treatment agents 4-1 to 4-7. Table 6 shows specific methods of surface treatment. The object to be processed is a silicon wafer with a SiN film (SiN substrate), a SiO ₂ substrate, and a Si substrate having a size of 10 mm × 50 mm. The substrate was designated as No. 6 in Table 6. 2-1. In the order of 2-14, after immersing each chemical solution (about 5 ml) weighed in a resin cup at a predetermined temperature for a predetermined time, blow off nitrogen gas for 20 seconds to remove water, and quickly contact angle Was measured. No. In the HF process in 2-4, a 1 minute process is performed. In the acid treatment in 2-9, a 12% hydrochloric acid aqueous solution was used. In the case of a SiO ₂ substrate, No. is used so that the oxide film does not melt. In the treatment in 2-4, the immersion time of the 1% HF aqueous solution was 30 seconds. Furthermore, the contact angle measurement method was the same as in Experimental Example 1-1. Table 7 shows the measurement results of the contact angle.

Experimental Example 4-2
No. The surface treatment of the SiN substrate was performed in the same manner as in Experimental Example 4-1, except that 16% sulfuric acid aqueous solution was used in the acid treatment in 2-9. The results are shown in Table 7.

Experimental Example 4-3
No. Surface treatment of the SiN substrate was performed in the same manner as in Experimental Example 4-1, except that 20% nitric acid aqueous solution was used in the acid treatment in 2-9. The results are shown in Table 7.

Experimental Example 4-4
No. A surface treatment of the SiN substrate was performed in the same manner as in Experimental Example 4-1, except that a 14% oxalic acid aqueous solution was used in the acid treatment in 2-9. The results are shown in Table 7.

Experimental Example 4-5
No. The surface treatment of the SiN substrate was carried out in the same manner as in Experimental Example 4-1, except that the acid treatment in 2-9 was omitted and instead it was immersed in deionized water for 2 minutes. The results are shown in Table 7.

By using the surface treating agent of the present invention, the surface of a semiconductor substrate or the like that has a pattern with a high aspect ratio can be made water repellent uniformly, and the yield during semiconductor manufacturing can be improved. .

In addition, according to the surface treatment method of the present invention, the surface of the semiconductor substrate having a high aspect ratio pattern can be made water repellent uniformly, and the yield during semiconductor manufacturing can be improved. it can.

Claims

The surface treating agent characterized by including the compound (A) represented by following General formula (1).

[Wherein R 6 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R 1 , R 2 , R 3 , R 4 and R 5 are each independently a hydrogen atom, a cyanoalkyl group, , An alkyl group, an aralkyl group, a cycloalkyl group, a cycloaralkyl group or an aryl group, and at least one of R 1 , R 2 , R 3 , R 4 and R 5 is a hydrogen atom. a, w, x, y and z are each independently 0 or a positive number, at least one of w and x is a positive number, 0 ≦ w / (x + y) ≦ 5, 0 ≦ z / (a + w + x + y) ≦ 1. Compound A may contain only 1 type of each structural unit, and may contain 2 or more types. ]
The surface treating agent according to claim 1, wherein the compound (A) is represented by the following general formula (4).

[Wherein, R 3 and R 5 are each independently a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group, a cycloaralkyl group or an aryl group, and w, x and y are independently of each other, It is a positive number and z is 0 or a positive number. ]
The surface treating agent according to claim 1, wherein at least one of R 1 , R 2 , R 3 , R 4 and R 5 in the general formula (1) is a cyanoalkyl group.
The surface treating agent according to claim 3, wherein the compound (A) is represented by the following general formula (7).

[Wherein, B is a cyanoalkyl group, b, x, y and z are each independently 0 or a positive number, and c is a positive number. ]
The surface treating agent according to claim 4, wherein in the general formula (7), the ratio b / c is in the range of 0.1 to 20.
The surface treating agent according to any one of claims 1 to 5, wherein the number average molecular weight of the compound (A) is 240 to 10,000.
Furthermore, the surface treating agent as described in any one of Claims 1 thru | or 6 containing the compound (B) represented by following General formula (11).

[Wherein R 11 , R 12 and R 13 are each independently a hydrogen atom, alkyl group, aralkyl group, cycloalkyl group, cycloaralkyl group or aryl group, and R 14 and R 15 are independently A hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, a trimethylsilyl group, a dimethylsilyl group, or a saturated or unsaturated heterocycloalkyl group, and R 14 and R 15 are bonded to each other. Or a saturated or unsaturated heterocycloalkyl group having a nitrogen atom. ]
The surface treating agent according to claim 7, wherein the compound (B) is at least one of N, N-diethylaminotrimethylsilane and N, N-dimethylaminotrimethylsilane.
Furthermore, the surface treating agent according to any one of claims 1 to 8, further comprising an organic solvent.
The surface treating agent according to any one of claims 1 to 9, which is used for water repellency of a surface of an object to be treated.
A surface treatment method for making a surface of a treatment object water repellent, comprising a contact step of bringing the surface treatment agent according to claim 1 into contact with the treatment object. Processing method.
The surface treatment method according to claim 11, wherein the workpiece is a semiconductor substrate.
The surface treatment method according to claim 11 or 12, wherein the object to be treated contains silicon nitride in a part of its surface.
The surface treatment method according to any one of claims 11 to 13, wherein the object to be treated contains silicon oxide in a part of its surface.
The surface treatment method according to any one of claims 11 to 14, wherein the object to be treated contains metallic silicon in a part of its surface.
The surface treatment method according to any one of claims 11 to 15, further comprising an acid contact step in which an acidic liquid containing an acid is brought into contact with the object to be processed before the contact step.
The surface treatment method according to claim 16, wherein the acid is an inorganic acid having an acid dissociation constant (pKa) of less than 0.
The object to be processed has a silicon nitride film and a silicon oxide film on the surface thereof, and after the contact step, the contact angle (Can) of water on the surface of the silicon nitride film and the surface of the silicon oxide film The surface treatment method according to claim 17, wherein the ratio (Can / Cao) to the contact angle (Cao) of water is in the range of 0.7 to 1.3.
The surface according to any one of claims 11 to 15, further comprising a solvent replacement step after the step of contacting with the liquid containing water, and then bringing the surface treatment agent diluted with an organic solvent into contact with the object to be treated. Processing method.
In a surface treatment method for making a surface of a semiconductor substrate water repellent, a first step of bringing an acid liquid containing an acid into contact with the semiconductor substrate, and a surface treatment agent containing a compound represented by the following general formula (11): A surface treatment method comprising sequentially providing a second step of contacting the semiconductor substrate.

[Wherein R 11 , R 12 and R 13 are each independently a hydrogen atom, alkyl group, aralkyl group, cycloalkyl group, cycloaralkyl group or aryl group, and R 14 and R 15 are independently A hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, a trimethylsilyl group, a dimethylsilyl group, or a saturated or unsaturated heterocycloalkyl group, and R 14 and R 15 are bonded to each other. Or a saturated or unsaturated heterocycloalkyl group having a nitrogen atom. ]
21. The surface treatment method according to claim 20, wherein the acid is an inorganic acid having an acid dissociation constant (pKa) of less than 0.
The method for treating a surface of a semiconductor substrate according to claim 20 or 21, wherein the semiconductor substrate has silicon nitride on at least a part of its surface.
23. The surface treatment method for a semiconductor substrate according to claim 22, wherein the semiconductor substrate has at least two portions of metal silicon, silicon nitride, and silicon oxide on at least a part of the surface thereof.
The semiconductor substrate has a silicon nitride film and a silicon oxide film on its surface, and after the second step, the contact angle (Can) of water on the surface of the silicon nitride film and the surface of the silicon oxide film The surface treatment method for a semiconductor substrate according to any one of claims 20 to 23, wherein a ratio (Can / Cao) to a water contact angle (Cao) is in a range of 0.7 to 1.3.