WO2017030073A1

WO2017030073A1 - Wafer washing method, and liquid chemical used in same

Info

Publication number: WO2017030073A1
Application number: PCT/JP2016/073619
Authority: WO
Inventors: 崇齋尾; 雄三奥村; 由季福井; 宏紀深澤; 朋宏高田; 公文　創一; 一之阿部; 翔太渡辺; 昌義井町
Original assignee: セントラル硝子株式会社
Priority date: 2015-08-20
Filing date: 2016-08-10
Publication date: 2017-02-23
Also published as: TW201715010A; TWI657126B

Abstract

[Problem] To provide a liquid chemical used for forming a water repellent protective membrane, said liquid chemical being used in a wafer washing method in which a washing device that includes a vinyl chloride resin as a wetted member is used. [Solution] A liquid chemical is used, said liquid chemical including at least one compound selected from the group consisting of: an alkoxysilane represented by general formula [1]; a sulfonic acid represented by general formula [2]; an anhydrate of said sulfonic acid; a salt of said sulfonic acid; and a sulfonic acid derivative represented by general formula [3]. Also included in the liquid chemical is a dilution solvent having at least one compound selected from the group consisting of a hydrocarbon, ether, and thiol. [1] (R1) aSi (H)b (OR2)4-a-b [2] R3 – S(=O)2OH [3] R3 – S (=O)2 O-Si (H)3-c (R4)c

Description

Wafer cleaning method and chemical used in the cleaning method

The present invention relates to a wafer cleaning method using a predetermined chemical solution in cleaning a wafer using a cleaning apparatus including a vinyl chloride resin as a liquid contact member.

As described in Patent Documents 1 to 8, some wafer cleaning apparatuses use a vinyl chloride resin as a member that comes into contact with a cleaning solution or a processing solution (a liquid contact member). There is a need to not degrade the vinyl resin. As a cleaning apparatus containing a vinyl chloride resin as a liquid contact member, for example, a wafer cleaning apparatus or tank in which a part or all of the members that come into contact with the cleaning liquid or the processing liquid in the cleaning processing tank are made of vinyl chloride resin, a tank, Examples include a wafer cleaning apparatus in which a part or all of the members that come into contact with the cleaning liquid or processing liquid such as piping, connecting members, and nozzles are made of vinyl chloride resin.

In semiconductor devices for networks and digital home appliances, higher performance, higher functionality, and lower power consumption are required. For this reason, miniaturization of the circuit pattern is progressing, and as the miniaturization progresses, pattern collapse of the circuit pattern becomes a problem. In semiconductor device manufacturing, a cleaning process for the purpose of removing particles and metal impurities is frequently used. As a result, the cleaning process accounts for 30 to 40% of the entire semiconductor manufacturing process. In this cleaning process, when the aspect ratio of the pattern increases with the miniaturization of the semiconductor device, the pattern collapses when the gas-liquid interface passes through the pattern after cleaning or rinsing. In order to prevent the occurrence of pattern collapse, the design of the pattern must be changed, or the yield during production may be reduced. Therefore, a method for preventing pattern collapse in the cleaning process is desired.

As a method for preventing pattern collapse, it is known that it is effective to form a water-repellent protective film on the pattern surface. Since this water repellency needs to be performed without drying the pattern surface, the water repellent protective film is formed with a water repellent protective film forming chemical that can make the pattern surface water repellent.

In the method of manufacturing a wafer having a fine concavo-convex pattern on the surface and at least a part of the concavo-convex pattern containing silicon element in Patent Document 9, the present applicant easily induces pattern collapse without impairing throughput. As a protective film forming chemical for forming a water-repellent protective film on the uneven pattern surface of the wafer to improve the cleaning process,
A chemical solution for forming a water-repellent protective film on at least the concave surface of the concavo-convex pattern at the time of cleaning a wafer having a fine concavo-convex pattern on the surface and at least a part of the concavo-convex pattern containing silicon element. The total amount of water in the starting material of the chemical solution, the silicon compound A represented by [A] and the acid that donates protons to the silicon compound A and / or the acid that accepts electrons from the silicon compound A A chemical solution for forming a water-repellent protective film, characterized in that it is 5000 ppm by mass or less with respect to the total amount of raw materials, and a wafer cleaning method using the same are disclosed.
R ¹ _a Si (H) _b (X) _4-ab [A]
(In the formula [A], R ^{1 s} each independently contain a monovalent organic group containing a hydrocarbon group having 1 to 18 carbon atoms and a fluoroalkyl chain having 1 to 8 carbon atoms. X is at least one group selected from a valent organic group, and X is independently of each other at least one selected from a halogen group, a monovalent organic group in which the element bonded to Si is oxygen or nitrogen, or a nitrile group A is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a and b is 3 or less.)

JP 05-259136 A JP 07-245283 A Japanese Patent Laid-Open No. 10-189527 Japanese Patent Laid-Open No. 10-229062 JP 11-283949 A JP 2001-087725 A JP 2008-098440 A JP 2010-003739 A JP 2012-033873 A

In a method for cleaning a wafer having a fine concavo-convex pattern on the surface with a wafer cleaning apparatus containing a vinyl chloride resin as a liquid contact member and at least a part of the concavo-convex pattern containing silicon element,
For example, when the chemical solution for forming a water-repellent protective film described in Example 4 of Patent Document 9 is used, the vinyl chloride resin may be deteriorated by the chemical solution.

Therefore, the present invention is a wafer cleaning apparatus containing a vinyl chloride resin as a liquid contact member, and a wafer having a fine concavo-convex pattern on the surface and at least a part of the concavo-convex pattern containing silicon element (hereinafter simply referred to as “wafer”). In the method of cleaning)
A water repellent protective film forming chemical (hereinafter simply referred to as a “water repellent protective film”) that forms a water repellent protective film (hereinafter sometimes simply referred to as “protective film”) on the surface of the concavo-convex pattern of the wafer without deteriorating the vinyl chloride resin. It is an object of the present invention to provide a method for cleaning a wafer using the chemical solution.

The present invention provides a method for cleaning a wafer having a fine concavo-convex pattern on a surface thereof and having at least a part of the concavo-convex pattern containing silicon element by a wafer cleaning apparatus containing a vinyl chloride resin as a liquid contact member.
An alkoxysilane represented by the following general formula [1], a sulfonic acid represented by the following general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a general formula [3] At least one selected from the group consisting of sulfonic acid derivatives
As well as a diluent solvent,
The dilution solvent includes at least one solvent selected from the group consisting of hydrocarbon, ether, and thiol, and the total amount of the hydrocarbon, ether, and thiol is 100% by mass of the total amount of the dilution solvent. This is a wafer cleaning method in which a water-repellent protective film-forming chemical solution of 80 to 100% by mass is held in at least the concave portion of the concave-convex pattern, and a water-repellent protective film is formed on the concave surface.
(R ¹ ) _a Si (H) _b (OR ² ) _4-ab [1]
[In the formula [1], each R ¹ is independently selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. At least one group, and R ² is each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a and b is 3 or less. ]
R ³ —S (═O) ₂ OH [2]
[In the formula [2], R ³ is selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced with fluorine elements, and hydroxyl groups. Group. ]
R ³ —S (═O) ₂ O—Si (H) _{3 -c} (R ⁴ ) _c [3]
[In the formula [3], R ³ is a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R ⁴ are each Independently, at least one group selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced with fluorine elements, and c is 1 to 3 Is an integer. ]

The sulfonic acid is preferably at least one selected from the group consisting of sulfonic acids represented by the following general formula [4].
R ⁵ —S (═O) ₂ OH [4]
[In the formula [4], R ⁵ is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. . ]

The sulfonic acid anhydride is preferably at least one selected from the group consisting of sulfonic acid anhydrides represented by the following general formula [4].
R ⁵ —S (═O) ₂ OH [4]
[In the formula [4], R ⁵ is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. . ]

The sulfonic acid salt is preferably at least one selected from the group consisting of an ammonium salt and an alkylamine salt of a sulfonic acid represented by the following general formula [4].
R ⁵ —S (═O) ₂ OH [4]
[In the formula [4], R ⁵ is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. . ]

The sulfonic acid derivative is preferably at least one selected from the group consisting of sulfonic acid derivatives represented by the following general formula [5].
R ⁶ —S (═O) ₂ O—Si (CH ₃ ) ₂ (R ⁷ ) [5]
[In the formula [5], R ⁶ is a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R ⁷ is a part of Alternatively, it is a monovalent hydrocarbon group having 1 to 18 carbon atoms in which all hydrogen elements may be replaced with fluorine elements. ]

It is preferable that the hydrocarbon is a hydrocarbon having 6 to 13 carbon atoms.

The ether is preferably an ether represented by the following general formula [6].
R ⁸ —O—R ⁹ [6]
[In the formula [6], R ⁸ and R ⁹ are each independently a monovalent carbon atom having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. It is a hydrogen group, and the total number of carbon atoms of R ⁸ and R ⁹ is 4 to 16. ]

The thiol is preferably a thiol having 6 to 13 carbon atoms.

The alkoxysilane is preferably at least one selected from the group consisting of alkoxysilanes represented by the following general formula [7].
(R ¹⁰ ) _d Si (OR ¹¹ ) _4-d [7]
[In the formula [7], R ^{10 s} are each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, R ¹¹ Are each independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, and d is 2 or 3. ]

The alkoxysilane is preferably at least one selected from the group consisting of monoalkoxysilanes represented by the following general formula [8].
R ¹⁰ —Si (CH ₃ ) ₂ (OR ¹¹ ) [8]
[In the formula [8], R ¹⁰ is a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R ¹¹ is 1 carbon atom. Is a monovalent hydrocarbon group of ˜12. ]

The concentration of the alkoxysilane in the chemical solution for forming the water repellent protective film is preferably 0.5 to 35% by mass.

The total concentration of the sulfonic acid, the sulfonic acid anhydride, the sulfonic acid salt, and the sulfonic acid derivative in the water repellent protective film-forming chemical solution is preferably 0.0001 to 5% by mass. .

After holding the water repellent protective film forming chemical in at least the recesses of the concave and convex pattern to form a water repellent protective film on the concave surface, the water repellent protective film forming chemical is removed from the recesses by drying. It is preferable.

The water-repellent protective film-forming chemical solution is held in at least the concave portion of the concavo-convex pattern, and after forming the water-repellent protective film on the concave surface, the water-repellent protective film-forming chemical solution in the concave portion is different from the chemical solution. It is preferable to replace with a cleaning liquid and remove the cleaning liquid from the recess by drying.

Further, the water-repellent protective film is removed by performing at least one treatment selected from the group consisting of heat treatment, light irradiation treatment, ozone exposure treatment, plasma irradiation treatment, and corona discharge treatment on the wafer surface after the drying. May be.

In addition, the above cleaning method is
at least,
Containing an alkoxysilane represented by the above general formula [1], or
A diluting solvent containing an alkoxysilane represented by the general formula [1] and at least one solvent selected from the group consisting of hydrocarbons, ethers, and thiols,
The first liquid,
At least one selected from the group consisting of a sulfonic acid represented by the general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a sulfonic acid derivative represented by the general formula [3]. Including or
At least one selected from the group consisting of a sulfonic acid represented by the above general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a sulfonic acid derivative represented by the general formula [3]; A diluting solvent comprising at least one solvent selected from the group consisting of: hydrocarbons, ethers, and thiols,
A second liquid,
You may have the process of obtaining the said chemical | medical solution for water-repellent protective film formation by mixing the chemical | medical solution kit for water-repellent protective film formation in which at least one of a 1st liquid and a 2nd liquid contains the said dilution solvent.

Further, the present invention is used for cleaning a wafer having a fine concavo-convex pattern on the surface thereof and at least a part of the concavo-convex pattern containing silicon element by a wafer cleaning apparatus containing a vinyl chloride resin as a liquid contact member. ,
An alkoxysilane represented by the following general formula [1], a sulfonic acid represented by the following general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a general formula [3] At least one selected from the group consisting of sulfonic acid derivatives
As well as a diluent solvent,
The dilution solvent includes at least one solvent selected from the group consisting of hydrocarbon, ether, and thiol, and the total amount of the hydrocarbon, ether, and thiol is 100% by mass of the total amount of the dilution solvent. It is a chemical solution for forming a water-repellent protective film, which is 80 to 100% by mass.
(R ¹ ) _a Si (H) _b (OR ² ) _4-ab [1]
[In the formula [1], each R ¹ is independently selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. At least one group, and R ² is each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a and b is 3 or less. ]
R ³ —S (═O) ₂ OH [2]
[In the formula [2], R ³ is selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced with fluorine elements, and hydroxyl groups. Group. ]
R ³ —S (═O) ₂ O—Si (H) _{3 -c} (R ⁴ ) _c [3]
[In the formula [3], R ³ is a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R ⁴ are each Independently, at least one group selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced with fluorine elements, and c is 1 to 3 Is an integer. ]

The thiol is preferably a thiol having 6 to 13 carbon atoms.

The present invention also provides:
A water repellent protective film forming chemical solution kit for obtaining the above water repellent protective film forming chemical solution by mixing,
at least,
Containing an alkoxysilane represented by the above general formula [1], or
A diluting solvent containing an alkoxysilane represented by the general formula [1] and at least one solvent selected from the group consisting of hydrocarbons, ethers, and thiols,
The first liquid,
At least one selected from the group consisting of a sulfonic acid represented by the general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a sulfonic acid derivative represented by the general formula [3]. Including or
At least one selected from the group consisting of a sulfonic acid represented by the above general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a sulfonic acid derivative represented by the general formula [3]; A diluting solvent comprising at least one solvent selected from the group consisting of: hydrocarbons, ethers, and thiols,
A second liquid,
A chemical solution kit for forming a water-repellent protective film, wherein at least one of the first liquid and the second liquid contains the dilution solvent.

The chemical solution for forming a water-repellent protective film of the present invention can form a water-repellent protective film on the surface of the concavo-convex pattern of the wafer without deteriorating the liquid contact member made of vinyl chloride resin in the wafer cleaning apparatus. Since the protective film formed by the chemical solution for forming a water-repellent protective film of the present invention is excellent in water repellency, it reduces the capillary force on the surface of the concavo-convex pattern of the wafer, and thus exhibits an effect of preventing pattern collapse. When the chemical solution is used, the cleaning step in the method for producing a wafer having a fine uneven pattern on the surface can be improved without lowering the throughput. Therefore, the method for producing a wafer having a fine concavo-convex pattern on the surface, which is performed using the chemical solution for forming a water repellent protective film of the present invention, has high productivity.

The aspect ratio of the circuit pattern on the wafer is expected to increase further with higher density. The chemical solution for forming a water-repellent protective film of the present invention can be applied to cleaning an uneven pattern having an aspect ratio of 7 or more, for example, and can reduce the production cost of a higher-density semiconductor device. In addition, the conventional apparatus can be applied without major changes such as a wetted member, and as a result, can be applied to the manufacture of various semiconductor devices.

It is a schematic diagram when the wafer 1 made into the surface which has the fine uneven | corrugated pattern 2 on the surface is seen. FIG. 2 shows a part of the a-a ′ cross section in FIG. 1. It is a schematic diagram of the state in which the recessed part 4 hold | maintained the chemical | medical solution 8 for protective film formation at the washing | cleaning process. It is a schematic diagram of the state by which the liquid was hold | maintained at the recessed part 4 in which the protective film was formed.

(1) About the water-repellent protective film-forming chemical solution
An alkoxysilane represented by the following general formula [1], a sulfonic acid represented by the following general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a general formula [3] At least one selected from the group consisting of sulfonic acid derivatives
As well as a diluent solvent,
The dilution solvent includes at least one solvent selected from the group consisting of hydrocarbon, ether, and thiol, and the total amount of the hydrocarbon, ether, and thiol is 100% by mass of the total amount of the dilution solvent. 80 to 100% by mass.
(R ¹ ) _a Si (H) _b (OR ² ) _4-ab [1]
[In the formula [1], each R ¹ is independently selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. At least one group, and R ² is each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a and b is 3 or less. ]
R ³ —S (═O) ₂ OH [2]
[In the formula [2], R ³ is selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced with fluorine elements, and hydroxyl groups. Group. ]
R ³ —S (═O) ₂ O—Si (H) _{3 -c} (R ⁴ ) _c [3]
[In the formula [3], R ³ is a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R ⁴ are each Independently, at least one group selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced with fluorine elements, and c is 1 to 3 Is an integer. ]

R ¹ of the alkoxysilane is a water-repellent functional group. Then, the alkoxysilane alkoxy groups (-OR ² group) reacts with the silanol groups on the wafer surface, by site having a functional group of the water-repellent is fixed to the wafer surface, the water repellent on the wafer surface A protective film is formed. When the alkoxysilane and at least one selected from the group consisting of the sulfonic acid, the sulfonic acid anhydride, the sulfonic acid salt, and the sulfonic acid derivative are used, the alkoxysilane and the wafer surface react quickly. As a result, the effect of imparting water repellency is obtained.

Specific examples of the _{_{alkoxysilane, CH 3 Si (OCH 3)}} 3, C 2 H 5 Si (OCH 3) 3, C 3 H 7 Si (OCH 3) 3, C 4 H 9 Si (OCH 3) 3 _{_{, C 5 H 11 Si (OCH}} 3) 3, C 6 H 13 Si (OCH 3) 3, C 7 H 15 Si (OCH 3) 3, C 8 H 17 Si (OCH 3) 3, C 9 H 19 Si (OCH ₃ ) ₃ , C ₁₀ H ₂₁ Si (OCH ₃ ) ₃ , C ₁₁ H ₂₃ Si (OCH ₃ ) ₃ , C ₁₂ H ₂₅ Si (OCH ₃ ) ₃ , C ₁₃ H ₂₇ Si (OCH ₃ ) ₃ , C ₁₄ H ₂₉ Si (OCH ₃ ) ₃ , C ₁₅ H ₃₁ Si (OCH ₃ ) ₃ , C ₁₆ H ₃₃ Si (OCH ₃ ) ₃ , C ₁₇ H ₃₅ Si (OCH ₃ ) ₃ , C ₁₈ H ₃₇ Si ( OCH ₃ ) ₃ , (CH ₃ ) ₂ Si (OCH ₃ ) ₂ , C ₂ H ₅ Si (CH ₃ ) (OCH ₃ ) ₂ , (C ₂ H ₅ ) ₂ Si (OCH ₃ ) ₂ , C ₃ H ₇ Si (CH ₃ ) (OCH ₃ ) ₂ , (C ₃ H ₇ ) ₂ Si (OCH ₃ ) ₂ , C ₄ H ₉ Si (CH ₃ ) (OCH ₃ ) ₂ , (C ₄ H ₉ ) ₂ Si (OCH _{_{_{_{3) 2, C 5 H 11}}}} Si (CH 3) (OCH 3) 2, C 6 H 13 Si (CH 3) (OCH 3) 2, C 7 H 15 Si (CH 3) (OCH 3) 2, C ₈ H ₁₇ Si (CH ₃ ) (OCH ₃ ) ₂ , C ₉ H ₁₉ Si (CH ₃ ) (OCH ₃ ) ₂ , C ₁₀ H ₂₁ Si (CH ₃ ) (OCH ₃ ) ₂ , C ₁₁ H ₂₃ Si ( CH ₃ ) (OCH ₃ ) ₂ , C ₁₂ H ₂₅ Si (CH ₃ ) (OCH ₃ ) ₂ , C ₁₃ H ₂₇ Si (CH ₃ ) (OCH ₃ ) ₂ , C ₁₄ H ₂₉ Si (CH ₃ ) (OCH _{_{_{_{3) 2, C 15 H 31}}}} Si (CH 3) (OCH 3) 2, C 16 H 33 Si (CH 3) (OCH 3) 2, C 17 H 35 Si (CH 3) (OCH 3) 2, C ₁₈ H ₃₇ Si (CH ₃ _{_{(OCH 3) 2, (CH}} 3) 3 SiOCH 3, C 2 H 5 Si (CH 3) 2 OCH 3, (C 2 H 5) 2 Si (CH 3) OCH 3, (C 2 H 5) 3 SiOCH ₃ , C ₃ H ₇ Si (CH ₃ ) ₂ OCH ₃ , (C ₃ H ₇ ) ₂ Si (CH ₃ ) OCH ₃ , (C ₃ H ₇ ) ₃ SiOCH ₃ , C ₄ H ₉ Si (CH ₃ ) ₂ OCH ₃ , (C ₄ H ₉ ) ₃ SiOCH ₃ , C ₅ H ₁₁ Si (CH ₃ ) ₂ OCH ₃ , C ₆ H ₁₃ Si (CH ₃ ) ₂ OCH ₃ , C ₇ H ₁₅ Si (CH ₃ ) ₂ OCH ₃ , C ₈ H ₁₇ Si (CH ₃ ) ₂ OCH ₃ , C ₉ H ₁₉ Si (CH ₃ ) ₂ OCH ₃ , C ₁₀ H ₂₁ Si (CH ₃ ) ₂ OCH ₃ , C ₁₁ H ₂₃ Si (CH ₃ ) ₂ OCH ₃ , C ₁₂ H ₂₅ Si (CH ₃ ) ₂ OCH ₃ , C ₁₃ H ₂₇ Si (CH ₃ ) ₂ OCH ₃ , C ₁₄ H ₂₉ Si (CH ₃ ) ₂ OCH ₃ , C ₁₅ H ₃₁ S _{_{_{i (CH 3) 2 OCH 3}}} , C 16 H 33 Si (CH 3) 2 OCH 3, C 17 H 35 Si (CH 3) 2 OCH 3, C 18 H 37 Si (CH 3) 2 OCH 3, (CH ₃ ) ₂ Si (H) OCH ₃ , CH ₃ Si (H) ₂ OCH ₃ , (C ₂ H ₅ ) ₂ Si (H) OCH ₃ , C ₂ H ₅ Si (H) ₂ OCH ₃ , C ₂ H ₅ Si (CH ₃ ) (H) OCH ₃ , (C ₃ H ₇ ) ₂ Alkyl methoxysilane such as Si (H) OCH ₃ , or CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₂ F ₅ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₃ F ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₄ F ₉ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₅ F ₁₁ CH ₂ CH ₂ Si ( _{_{_{OCH 3) 3, C 6 F}}} 13 CH 2 CH 2 Si (OCH 3) 3, C 7 F 15 CH 2 CH 2 Si (OCH 3) 3, C 8 F 17 CH 2 CH 2 Si _{_{_{OCH 3) 3, CF 3 CH}}} 2 CH 2 Si (CH 3) (OCH 3) 2, C 2 F 5 CH 2 CH 2 Si (CH 3) (OCH 3) 2, C 3 F 7 CH 2 CH 2 Si (CH ₃ ) (OCH ₃ ) ₂ , C ₄ F ₉ CH ₂ CH ₂ Si (CH ₃ ) (OCH ₃ ) ₂ , C ₅ F ₁₁ CH ₂ CH ₂ Si (CH ₃ ) (OCH ₃ ) ₂ , C ₆ _{_{_{F 13 CH 2 CH 2 Si (}}} CH 3) (OCH 3) 2, C 7 F 15 CH 2 CH 2 Si (CH 3) (OCH 3) 2, C 8 F 17 CH 2 CH 2 Si (CH 3) ( _{_{_{OCH 3) 2, CF 3 CH}}} 2 CH 2 Si (CH 3) 2 OCH 3, C 2 F 5 CH 2 CH 2 Si (CH 3) 2 OCH 3, C 3 F 7 CH 2 CH 2 Si (CH 3) _{_{_{_{2 OCH 3, C 4 F 9}}}} CH 2 CH 2 Si (CH 3) 2 OCH 3, C 5 F 11 CH 2 CH 2 Si (CH 3) 2 OCH 3, C 6 F 13 CH 2 CH 2 _{_{_{i (CH 3) 2 OCH 3}}} , C 7 F 15 CH 2 CH 2 Si (CH 3) 2 OCH 3, C 8 F 17 CH 2 CH 2 Si (CH 3) 2 OCH 3, CF 3 CH 2 CH 2 Si Fluoroalkylmethoxysilane such as (CH ₃ ) (H) OCH ₃ , or the methyl group part of the methoxy group of the methoxysilane has a carbon number in which some or all of the hydrogen elements may be replaced with fluorine elements. Examples thereof include compounds substituted with 2 to 18 monovalent hydrocarbon groups.

Further, from the viewpoint of the effect of imparting water repellency, the number of carbon atoms of R ² of the alkoxy group (—OR ² group) is preferably 1 to 12, and the number of alkoxy groups (—OR ² group) is one, Or two is preferable. Further, from the viewpoint of easy maintenance of water repellency after forming the protective film, the number (b) of —H groups in the alkoxysilane represented by the general formula [1] is preferably zero. For this reason, the alkoxysilane is preferably at least one selected from the group consisting of alkoxysilanes represented by the following general formula [7].
(R ¹⁰ ) _d Si (OR ¹¹ ) _4-d [7]
[In the formula [7], R ^{10 s} are each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, R ¹¹ Are each independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, and d is 2 or 3. ]

Further, among the above specific examples, from the viewpoint of water repellency imparting effect, the alkoxysilane is preferably at least one selected from the group consisting of monoalkoxysilanes represented by the following general formula [8].
R ¹⁰ —Si (CH ₃ ) ₂ (OR ¹¹ ) [8]
[In the formula [8], R ¹⁰ is a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R ¹¹ is 1 carbon atom. Is a monovalent hydrocarbon group of ˜12. ]

Specific examples of the monoalkoxysilane represented by the general formula [8] include (CH ₃ ) ₃ SiOCH ₃ , C ₂ H ₅ Si (CH ₃ ) ₂ OCH ₃ , and C ₃ H ₇ Si (CH ₃ ) _2. OCH ₃ , C ₄ H ₉ Si (CH ₃ ) ₂ OCH ₃ , C ₅ H ₁₁ Si (CH ₃ ) ₂ OCH ₃ , C ₆ H ₁₃ Si (CH ₃ ) ₂ OCH ₃ , C ₇ H ₁₅ Si (CH ₃ ) ₂ OCH ₃ , C ₈ H ₁₇ Si (CH ₃ ) ₂ OCH ₃ , CF ₃ CH ₂ CH ₂ Si (CH ₃ ) ₂ OCH ₃ , C ₂ F ₅ CH ₂ CH ₂ Si (CH ₃ ) ₂ OCH ₃ , _{_{_{_{C 3 F 7 CH 2 CH 2}}}} Si (CH 3) 2 OCH 3, C 4 F 9 CH 2 CH 2 Si (CH 3) 2 OCH 3, C 5 F 11 CH 2 CH 2 Si (CH 3) 2 OCH 3 alkyldimethyl monoalkoxysilane such as _{_{_{_{C 6 F 13 CH 2 CH 2}}}} Si (CH 3) 2 OCH 3 or, the alkyl Methyl moiety of a methoxy group of dimethyl monoalkoxysilanes include compounds is replaced with monovalent hydrocarbon group having 2 to 12 carbon atoms and the like. Further, from the viewpoint of imparting water repellency, R ¹⁰ is preferably a monovalent linear hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, Further, a monovalent unsubstituted linear hydrocarbon group having 1 to 8 carbon atoms is preferable, and a methyl group is particularly preferable. In the above R ¹¹ , the carbon atom bonded to the oxygen atom is preferably a primary carbon atom and is preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms. Specific examples of particularly preferred monoalkoxysilanes include (CH ₃ ) ₃ SiOCH ₃ , (CH ₃ ) ₃ SiOC ₂ H ₅ , (CH ₃ ) ₃ SiOCH ₂ CH ₂ CH ₃ , (CH ₃ ) ₃ SiOCH ₂ CH _2. _{_{_{CH 2 CH 3, (CH 3}}} ) 3 SiOCH 2 CH (CH 3) 2, (CH 3) 3 SiOCH 2 CH 2 CH 2 CH 2 CH 3, (CH 3) 3 SiOCH 2 CH 2 CH (CH 3) 2 , (CH ₃ ) ₃ SiOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₃ , (CH ₃ ) ₃ SiOCH ₂ CH ₂ CH ₂ CH (CH ₃ ) ₂ , (CH ₃ ) ₃ SiOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₃ , (CH ₃ ) ₃ SiOCH ₂ CH ₂ CH ₂ CH ₂ CH (CH ₃ ) ₂ , (CH ₃ ) ₃ SiOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₃ , ( CH ₃ ) ₃ SiOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH (CH ₃ ) ₂ etc. are mentioned. Furthermore, considering the solubility with at least one selected from the group consisting of the sulfonic acid, the anhydride of the sulfonic acid, the salt of the sulfonic acid, and the sulfonic acid derivative represented by the general formula [3], The number of carbon atoms of the alkoxy group of the monoalkoxysilane is preferably 3-8, and more preferably 4-8.

The concentration of the alkoxysilane in the chemical solution is preferably 0.5 to 35% by mass. If it is 0.5 mass% or more, it is preferable because the water repellency imparting effect is easily exhibited. Moreover, since it is hard to degrade a vinyl chloride resin if it is 35 mass% or less, it is preferable. The concentration is more preferably 0.7 to 30% by mass, and further preferably 1.0 to 25% by mass. The concentration of alkoxysilane in the chemical solution is the alkoxysilane represented by the general formula [1], the sulfonic acid represented by the general formula [2], the anhydride of the sulfonic acid, and the salt of the sulfonic acid. , And at least one selected from the group consisting of sulfonic acid derivatives represented by the above general formula [3], and the mass% concentration of alkoxysilane with respect to the total amount of diluent solvent.

At least one selected from the group consisting of the sulfonic acid, the sulfonic acid anhydride, the sulfonic acid salt, and the sulfonic acid derivative is an alkoxy group (—OR ² group) of the alkoxysilane and a silanol on the wafer surface. It promotes the reaction with the group and may itself form part of the protective film. If an acid other than sulfonic acid, its anhydride, salt or derivative is used, the effect of imparting water repellency will be insufficient, or the vinyl chloride resin will be deteriorated. Hereinafter, “at least one selected from the group consisting of the sulfonic acid, the anhydride of the sulfonic acid, the salt of the sulfonic acid, and the sulfonic acid derivative” may be collectively referred to as “sulfonic acids”.

Specific examples of the sulfonic acid include sulfuric acid, methanesulfonic acid, benzenesulfonic acid, paratoluenesulfonic acid, trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, hexafluoropropanesulfonic acid, nonafluorobutanesulfonic acid, and tridecafluoro. Examples include hexanesulfonic acid. Further, from the viewpoint of promoting the above reaction (and in view of the effect of imparting water repellency), it is preferable that the R ³ group of the general formula [2] is a perfluoroalkyl group. A perfluoroalkyl group having 6 or less is preferable, and at least one selected from the group consisting of trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, heptafluoropropanesulfonic acid, nonafluorobutanesulfonic acid, and tridecafluorohexanesulfonic acid. Is preferred.

Specific examples of the sulfonic acid anhydride include the sulfonic acid anhydrides exemplified above. In addition, from the viewpoint of promoting the above reaction (and in view of the effect of imparting water repellency), an anhydride of a sulfonic acid in which the R ³ group of the general formula [2] is a perfluoroalkyl group is preferable, and the influence on the environment is further increased. In view of the above, a perfluoroalkyl group having 6 or less carbon atoms is preferable, and trifluoromethanesulfonic anhydride, pentafluoroethanesulfonic anhydride, heptafluoropropanesulfonic anhydride, nonafluorobutanesulfonic anhydride, trideca At least one selected from the group consisting of fluorohexanesulfonic anhydride is preferred.

Specific examples of the sulfonic acid salt include ammonium salts, dimethylamine salts, and diethylamine salts of the sulfonic acids exemplified above. From the viewpoint of promoting the above reaction (and in view of the effect of imparting water repellency), trifluoromethane is exemplified. Ammonium and dimethylamine salts of sulfonic acid, ammonium and dimethylamine salts of pentafluoroethanesulfonic acid, ammonium and dimethylamine salts of heptafluoropropanesulfonic acid, ammonium and dimethylamine salts of nonafluorobutanesulfonic acid, Preferred are ammonium salts and dimethylamine salts of decafluorohexanesulfonic acid.

Specific examples of the sulfonic acid derivatives include trimethylsilylmethanesulfonate, dimethylsilylmethanesulfonate, ethyldimethylsilylmethanesulfonate, propyldimethylsilylmethanesulfonate, tripropylsilylmethanesulfonate, butyldimethylsilylmethanesulfonate, octyldimethylsilylmethanesulfonate, and the like. Methane sulfonate silane, or the methyl group of the methane sulfonate silane is replaced with ethyl, propyl, butyl, octyl, perfluoromethyl, perfluoroethyl, perfluoropropyl, and perfluorobutyl groups. And the like. In addition, from the viewpoint of promoting the above reaction (and in view of the effect of imparting water repellency), the methyl group portion of the methanesulfonate silane is replaced with a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, or a perfluorobutyl group. The compounds are preferred.

Among the sulfonic acid, the sulfonic acid anhydride, the sulfonic acid salt, and the sulfonic acid derivative, from the viewpoint of impurities, the sulfonic acid, the sulfonic acid anhydride, and the sulfonic acid derivative are selected. It is preferable that there is at least one.

The total concentration of the sulfonic acid, the sulfonic acid anhydride, the sulfonic acid salt, and the sulfonic acid derivative in the chemical solution is preferably 0.0001 to 5% by mass. If it is 0.0001 mass% or more, the reaction promoting effect (and consequently the water repellency imparting effect) is easily exhibited, which is preferable. If it is 5% by mass or less, it is difficult to erode the wafer surface and the like, and it is difficult to remain on the wafer as an impurity. In addition, it is preferable that a non-homogeneous chemical solution does not occur without dissolving in the diluting solvent. The concentration is more preferably from 0.01 to 2% by mass, even more preferably from 0.05 to 1% by mass. The concentration of the total amount of the sulfonic acid, the anhydride of the sulfonic acid, the salt of the sulfonic acid, and the sulfonic acid derivative in the chemical solution is the alkoxysilane represented by the general formula [1], the general formula At least one selected from the group consisting of the sulfonic acid represented by [2], the anhydride of the sulfonic acid, the salt of the sulfonic acid, and the sulfonic acid derivative represented by the general formula [3], and a dilution solvent Is a mass% concentration of the total amount of the sulfonic acid, the anhydride of the sulfonic acid, the salt of the sulfonic acid, and the sulfonic acid derivative.

The at least one solvent selected from the group consisting of the hydrocarbon, ether, and thiol includes the alkoxysilane, the sulfonic acid, the sulfonic acid anhydride, the sulfonic acid salt, and the sulfonic acid derivative. It is a solvent for dissolving at least one selected from the group consisting of: Specific examples of the hydrocarbon include hexane, heptane, octane, nonane, decane, dodecane, tetradecane, hexadecane, octadecane, aicosane, cyclohexane, methylcyclohexane, decalin, benzene, toluene, xylene, diethylbenzene, and the like. Heptane, octane, nonane, decane, dodecane, tetradecane, hexadecane, octadecane, and eicosane are not limited to straight chains, and may be branched. When the number of carbon atoms is small, the hydrocarbon has high volatility and low flash point, which is not preferable from the viewpoint of safety and liquid preparation workability. On the other hand, a large number of carbon atoms is not preferable from the viewpoint of ease of handling because the viscosity increases. Therefore, the hydrocarbon preferably has 6 to 13 carbon atoms. From the viewpoint of safety and viscosity, saturated hydrocarbons having 8 to 12 carbon atoms are more preferable, octane, nonane, decane, dodecane, cyclohexane, methylcyclohexane, and decalin are preferable, and octane, nonane, decane, and dodecane are straightforward. It is not limited to a chain shape and may be branched.

Similarly, the ether is also preferably an ether represented by the following general formula [6] because a small number of carbon atoms is not preferable from the viewpoint of safety, and a large number of carbon atoms is not preferable from the viewpoint of ease of handling. It is preferable.
R ⁸ —O—R ⁹ [6]
[In the formula [6], R ⁸ and R ⁹ are each independently a monovalent carbon atom having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. It is a hydrogen group, and the total number of carbon atoms of R ⁸ and R ⁹ is 4 to 16. ]

Specific examples of the ether include dipropyl ether, ethyl butyl ether, dibutyl ether, ethyl amyl ether, diamyl ether, methyl cyclopentyl ether, ethyl hexyl ether, dihexyl ether, dioctyl ether, diphenyl ether, methyl perfluoropropyl ether, methyl perfluoro Examples include butyl ether, ethyl perfluorobutyl ether, methyl perfluorohexyl ether, and ethyl perfluorohexyl ether. The ether is not limited to a straight chain, and may be branched. In particular, ethyl t-butyl ether and methylcyclopentyl ether are preferable because they are difficult to oxidize, and methyl perfluoropropyl ether, methyl perfluorobutyl ether, ethyl perfluorobutyl ether, methyl perfluorohexyl ether, and ethyl perfluorohexyl ether are nonflammable. Dibutyl ether, diamyl ether, dihexyl ether, and dioctyl ether are preferable in terms of liquid preparation workability and high flash point.

The above thiol is obtained by replacing a hydrocarbon hydrogen atom with a mercapto group. The thiol is not preferable from the viewpoint of safety and environmental impact when the number of carbon atoms is small, and may deteriorate the vinyl chloride resin, and is not preferable from the viewpoint of ease of handling when the number of carbon atoms is large. Therefore, the thiol preferably has 6 to 13 carbon atoms. The thiol may have a plurality of mercapto groups, but preferably has one mercapto group.

Specific examples of the thiol include 1-hexanethiol, 2-hexanethiol, 3-hexanethiol, 2-methyl-1-pentanethiol, 3-methyl-1-pentanethiol, 4-methyl-1-pentanethiol, 2-methyl-2-pentanethiol, 3-methyl-2-pentanethiol, 4-methyl-2-pentanethiol, 2-methyl-3-pentanethiol, 3-methyl-3-pentanethiol, 2,2-dimethyl -1-butanethiol, 3,3-dimethyl-1-butanethiol, 3,3-dimethyl-2-butanethiol, 2-ethyl-1-butanethiol, 1-heptanethiol, 2-heptanethiol, 3-heptane Thiol, 4-heptanethiol, benzylthiol, 1-octanethiol, 2-octanethiol, -Octanethiol, 4-octanethiol, 2-ethyl-1-hexanethiol, 1-nonanethiol, 2-nonanethiol, 3-nonanethiol, 4-nonanethiol, 5-nonanethiol, 1-decanethiol, 2- Decanethiol, 3-decanethiol, 4-decanethiol, 5-decanethiol, tert-decanethiol, 1-undecanethiol, 2-undecanethiol, 3-undecanethiol, 4-undecanethiol, 5-undecanethiol, 6- Undecanethiol, 1-dodecanethiol, 2-dodecanethiol, 3-dodecanethiol, 4-dodecanethiol, 5-dodecanethiol, 6-dodecanethiol, tert-dodecanethiol, 1-tridecanethiol, 2-tridecanethiol, 3-tride Nchioru, 4-tridecane thiol, 5-tridecane thiol, 6-tridecane thiol, 7-tridecane thiol, and the like.

From the viewpoint of water repellency imparting effect, 1-hexanethiol, 2-methyl-1-pentanethiol, 3-methyl-1-pentanethiol, 4-methyl-1-pentanethiol, 2,2-dimethyl-1- Butanethiol, 3,3-dimethyl-1-butanethiol, 2-ethyl-1-butanethiol, 1-heptanethiol, benzylthiol, 1-octanethiol, 2-ethyl-1-hexanethiol, 1-nonanethiol, Primary thiols such as 1-decanethiol, 1-undecanethiol, 1-dodecanethiol and 1-tridecanethiol are preferred.

The chemical solution of the present invention may contain an organic solvent other than at least one solvent selected from the group consisting of hydrocarbons, ethers, and thiols, but the viewpoint of preventing the deterioration of the vinyl chloride resin, And / or from a viewpoint of the water-repellent provision effect, another organic solvent is less than 20 mass% with respect to 100 mass% of solvent total amount. From the viewpoint of achieving a well-balanced effect of preventing the deterioration of the vinyl chloride resin and imparting water repellency, it is preferably less than 10% by mass, and more preferably less than 5% by mass. That is, at least one solvent selected from the group consisting of hydrocarbons, ethers, and thiols is 80 to 100% by mass, preferably 90 to 100% by mass, with respect to 100% by mass of the total amount of solvent. More preferably, it is ˜100 mass%.

Examples of organic solvents other than at least one solvent selected from the group consisting of hydrocarbons, ethers, and thiols include, for example, esters, ketones, halogen-containing solvents, sulfoxide solvents, lactone solvents, carbonate solvents, Examples include alcohols and polyhydric alcohol derivatives. In particular, alcohols and derivatives of polyhydric alcohols having an OH group are preferable from the viewpoint of improving the solubility of sulfonic acids. Esters, ketones, halogen-containing solvents, polyhydric alcohols having no OH group This derivative is preferable from the viewpoint of the effect of imparting water repellency.

Moreover, the alkoxysilane and sulfonic acid contained in the said chemical | medical solution may be obtained by reaction. For example, it may be obtained by reacting a silylating agent and an alcohol as in the following formula [9].
(R ¹ ) _a Si (H) _{3 -a} -OS (= O) ₂ -R ³ + R ² OH
→ (R ¹ ) _a Si (H) _3−a —OR ² + R ³ —S (═O) ₂ —OH [9]
In the above reaction formula, R ¹ , R ² and a are the same as in general formula [1], and R ³ is the same as in general formula [2].

In addition, the alkoxysilane represented by the general formula [1] reacts with the sulfonic acid represented by the general formula [2], the anhydride of the sulfonic acid, or the salt of the sulfonic acid, thereby reacting with the general formula [3 ] May be formed. Accordingly, in the chemical solution of the present invention, the alkoxysilane represented by the general formula [1], the sulfonic acid represented by the general formula [2], the anhydride of the sulfonic acid, the salt of the sulfonic acid, A sulfonic acid derivative represented by the formula [3] may coexist.

The chemical solution of the present invention may contain additives such as a polymerization inhibitor, a chain transfer agent, and an antioxidant in order to further improve the stability of the chemical solution. For example, 4-methoxyphenol, dibutylhydroxytoluene, butylhydroxyanisole, 1,4-benzenediol, 2- (1,1-dimethylethyl) -1,4-benzenediol, 1,4-benzoquinone, 1-octanethiol 1-nonanethiol, 1-decanethiol, 1-undecanethiol, 1-dodecanethiol, octyl-3,5-di-tert-butyl-4-hydroxy-hydrocarbinic acid (manufactured by BASF, Irganox 1135), 6-tert -Butyl-2,4-xylenol and the like.

In addition, from the viewpoint of the cleanliness of the chemical solution, the above additive is preferably a liquid. For example, 1-dodecanethiol, octyl-3,5-di-tert-butyl-4-hydroxy-hydrocarbine which is liquid at 25 ° C. and atmospheric pressure. Acids (manufactured by BASF, Irganox 1135), 6-tert-butyl-2,4-xylenol and the like are preferable.

In addition, the total amount of moisture in the starting material of the chemical solution is preferably 2000 ppm by mass or less with respect to the total amount of the material. When the total amount of moisture exceeds 2000 mass ppm, the effects of the alkoxysilane, the sulfonic acid, the sulfonic acid anhydride, the sulfonic acid salt, and the sulfonic acid derivative are reduced, and the protective film is removed in a short time. It becomes difficult to form. For this reason, it is preferable that the total amount of water in the chemical solution raw material is as small as possible, particularly 500 mass ppm or less, and more preferably 200 mass ppm or less. Furthermore, since the storage stability of the said chemical | medical solution will fall easily when there are many amounts of water, the one where water content is small is preferable, 100 mass ppm or less, Furthermore, 50 mass ppm or less is preferable. In addition, although the said moisture content is so preferable that it is small, as long as it exists in said content range, 0.1 mass ppm or more may be sufficient as the moisture content in the said chemical | medical solution raw material. Therefore, at least one selected from the group consisting of alkoxysilane, sulfonic acid, sulfonic acid anhydride, sulfonic acid salt, and sulfonic acid derivative contained in the chemical solution, the dilution solvent contains a large amount of water. It is preferable not to.

Further, it is preferable that the number of particles larger than 0.2 μm in the liquid measurement in the liquid phase in the chemical solution is 100 or less per 1 mL of the chemical solution. If the number of particles larger than 0.2 μm is more than 100 per 1 mL of the chemical solution, pattern damage due to the particles may be induced, which causes a decrease in device yield and reliability. Further, it is preferable that the number of particles larger than 0.2 μm is 100 or less per mL of the chemical solution because washing with a solvent or water after forming the protective film can be omitted or reduced. The number of particles larger than 0.2 μm is preferably as small as possible, but may be 1 or more per 1 mL of the chemical solution as long as it is within the above content range. The particle measurement in the liquid phase in the chemical solution in the present invention is performed by using a commercially available measuring device in the light scattering liquid particle measurement method using a laser as a light source. , PSL (polystyrene latex) standard particle-based light scattering equivalent diameter.

Here, the particles are particles such as dust, dust, organic solids and inorganic solids contained as impurities in the raw materials, and dust, dust, organic solids and inorganic solids brought in as contaminants during the preparation of chemicals. It is a particle such as an object, and finally exists as a particle without being dissolved in a chemical solution.

In addition, the content of each element (metal impurity) of Na, Mg, K, Ca, Mn, Fe, Cu, Li, Al, Cr, Ni, Zn, and Ag in the chemical solution is 0 for each total amount of the chemical solution. .1 mass ppb or less is preferable. If the metal impurity content is more than 0.1 mass ppb with respect to the total amount of the chemical solution, it is likely to increase the junction leakage current of the device, which causes a decrease in device yield and reliability. Absent. Further, when the metal impurity content is 0.1 mass ppb or less with respect to the total amount of the chemical solution, the surface of the wafer (protective film surface) with the solvent or water after the protective film is formed on the wafer surface. This is preferable because cleaning can be omitted or reduced. For this reason, the content of the metal impurities is preferably as small as possible, but may be 0.001 mass ppb or more for each element with respect to the total amount of the chemical solution as long as it is within the above content range.

Further, the chemical solution of the present invention may be obtained by mixing a water-repellent protective film-forming chemical solution kit containing the first liquid and the second liquid described above.

(2) Water-repellent protective film In the present invention, the water-repellent protective film is a film that reduces the wettability of the wafer surface by being formed on the wafer surface, that is, a film that imparts water repellency. . In the present invention, the water repellency means that the surface energy of the article surface is reduced and the interaction (for example, hydrogen bond, intermolecular force) between water or other liquid and the article surface is reduced. It is. In particular, the effect of reducing the interaction with water is great, but it has the effect of reducing the interaction with a mixed liquid of water and a liquid other than water or a liquid other than water. By reducing the interaction, the contact angle of the liquid with the article surface can be increased. The water-repellent protective film may be formed from the above alkoxysilane or may contain a reaction product containing alkoxysilane as a main component.

(3) Wafer As the above wafer, the wafer surface is formed with a film containing a silicon element such as silicon, silicon oxide, or silicon nitride, or the surface of the concavo-convex pattern when the concavo-convex pattern is formed. In which at least a part of silicon contains silicon element such as silicon, silicon oxide, or silicon nitride. In addition, a protective film can be formed on the surface of a component containing a silicon element even for a wafer composed of a plurality of components containing at least a silicon element. As the wafer composed of the plurality of components, silicon, silicon oxide, silicon nitride and other components containing silicon elements are formed on the wafer surface, or when the concavo-convex pattern is formed, at least the concavo-convex pattern A part of which includes a silicon element such as silicon, silicon oxide, and silicon nitride is also included. In addition, it is the surface of the part containing the silicon element in the said uneven | corrugated pattern that can form a protective film with the said chemical | medical solution.

In general, in order to obtain a wafer having a fine concavo-convex pattern on the surface, first, after applying a resist to a smooth wafer surface, the resist is exposed through a resist mask, and the exposed resist or exposed A resist having a desired concavo-convex pattern is produced by etching away the resist that was not present. Moreover, the resist which has an uneven | corrugated pattern can be obtained also by pressing the mold which has a pattern to a resist. Next, the wafer is etched. At this time, the wafer surface corresponding to the concave portion of the resist pattern is selectively etched. Finally, when the resist is removed, a wafer having a fine uneven pattern is obtained.

After the surface of the wafer has a fine uneven pattern, the surface is cleaned with an aqueous cleaning solution, and the aqueous cleaning solution is removed by drying or the like. When the width of the concave portion is small and the aspect ratio of the convex portion is large, the pattern collapses. Is likely to occur. The concavo-convex pattern is defined as shown in FIGS. FIG. 1 is a schematic view when a wafer 1 whose surface has a fine concavo-convex pattern 2 is viewed from the perspective, and FIG. 2 shows a part of the aa ′ cross section in FIG. . As shown in FIG. 2, the width 5 of the concave portion is shown by the interval between the convex portions 3 adjacent to each other, and the aspect ratio of the convex portion is obtained by dividing the height 6 of the convex portion by the width 7 of the convex portion. It is represented by Pattern collapse in the cleaning process tends to occur when the width of the recess is 70 nm or less, particularly 45 nm or less, and the aspect ratio is 4 or more, particularly 6 or more.

(4) Wafer Cleaning Method A wafer having a fine uneven pattern on the surface obtained by etching as described above is an aqueous cleaning solution for removing etching residues and the like prior to the cleaning method of the present invention. The water-based cleaning liquid held in the recess after the cleaning may be replaced with a cleaning liquid different from the water-based cleaning liquid (hereinafter referred to as “cleaning liquid A”), and further cleaning may be performed.

Examples of the aqueous cleaning liquid include water or an aqueous solution in which at least one of organic solvents, hydrogen peroxide, ozone, acid, alkali, and surfactant is mixed in water (for example, the water content is 10 mass). % Or more).

The cleaning liquid A refers to an organic solvent, a mixture of the organic solvent and an aqueous cleaning liquid, and a cleaning liquid in which at least one of acid, alkali, and surfactant is mixed.

In the present invention, the cleaning method of the wafer is not particularly limited as long as the cleaning device capable of holding the chemical solution or the cleaning solution is used in at least the concave portion of the concave / convex pattern of the wafer. As a wafer cleaning method, a single wafer method typified by a cleaning method using a spin cleaning apparatus that cleans wafers one by one by supplying a liquid near the rotation center while rotating the wafer while holding the wafer substantially horizontal, A batch method using a cleaning apparatus that immerses and cleans a plurality of wafers in a cleaning tank may be used. The form of the chemical solution or the cleaning liquid when supplying the chemical solution or the cleaning liquid to at least the concave portion of the concave / convex pattern of the wafer is not particularly limited as long as it becomes liquid when held in the concave portion. And steam.

Examples of the organic solvent that is one of the preferred examples of the cleaning liquid A include hydrocarbons, esters, ethers, ketones, halogen-containing solvents, sulfoxide solvents, lactone solvents, carbonate solvents, alcohols, Examples include polyhydric alcohol derivatives, nitrogen element-containing solvents, and the like. Of these, hydrocarbons, ethers, alcohols, and polyhydric alcohol derivatives having no OH group and acetate group are preferable because the vinyl chloride resin is hardly deteriorated. When an organic solvent is used as the cleaning liquid A, hydrocarbons, ethers, alcohols, polyhydric alcohol derivatives having no OH group and acetate group, which are preferable solvents, are 80% by mass of the total amount of the organic solvent. It is desirable to occupy the above.

The chemical solution for forming a protective film of the present invention is used by replacing the above aqueous cleaning solution or cleaning solution A with the chemical solution. In addition, the replaced chemical liquid may be replaced with a cleaning liquid different from the chemical liquid (hereinafter referred to as “cleaning liquid B”).

In addition, the wafer cleaning method of the present invention includes mixing a water repellent protective film forming chemical solution kit including the first liquid and the second liquid, as described above, prior to the replacement of the aqueous cleaning liquid or the cleaning liquid A with the chemical liquid. By doing so, you may have the process of obtaining the said chemical | medical solution.

After the cleaning with the aqueous cleaning liquid or the cleaning liquid A as described above, the cleaning liquid is replaced with a protective film-forming chemical solution, and at least the surface of the concave and convex pattern has at least the surface of the concave and convex pattern while the chemical liquid is held in at least the concave portion Then, the protective film is formed. The protective film of the present invention does not necessarily have to be formed continuously, and does not necessarily have to be formed uniformly. However, since it can impart better water repellency, it can be applied continuously and uniformly. More preferably, it is formed.

FIG. 3 shows a schematic view of the state in which the recess 4 holds the protective film forming chemical 8. The wafer shown in the schematic diagram of FIG. 3 shows a part of the a-a ′ cross section of FIG. 1. At this time, a protective film is formed on the surface of the recess 4 to make the surface water repellent.

When the temperature of the chemical for forming a protective film is increased, the protective film is easily formed in a shorter time. The temperature at which a homogeneous protective film is easily formed is preferably 10 ° C. or higher and lower than the boiling point of the chemical solution, and particularly preferably 15 ° C. or higher and 10 ° C. lower than the boiling point of the chemical solution. The temperature of the chemical solution is preferably maintained at the temperature even when held in at least the concave portion of the concavo-convex pattern. The boiling point of the chemical solution means the boiling point of the component having the largest amount by mass ratio among the components contained in the protective film forming chemical solution.

After forming the protective film as described above, the chemical solution remaining in at least the concave portion of the concave / convex pattern may be replaced with the cleaning liquid B, and then the drying process may be performed. Examples of the cleaning liquid B include an aqueous cleaning liquid, an organic solvent, a mixture of an aqueous cleaning liquid and an organic solvent, a mixture of at least one of an acid, an alkali, and a surfactant, and a protective film with them. Examples include a mixture of chemicals for forming. The cleaning liquid B is more preferably water, an organic solvent, or a mixture of water and an organic solvent from the viewpoint of removing particles and metal impurities.

Examples of the organic solvent that is one of the preferred examples of the cleaning liquid B include hydrocarbons, esters, ethers, ketones, halogen-containing solvents, sulfoxide solvents, alcohols, polyhydric alcohol derivatives, nitrogen elements Examples thereof include a solvent. Of these, hydrocarbons, ethers, alcohols, and polyhydric alcohol derivatives having no OH group and acetate group are preferable because the vinyl chloride resin is hardly deteriorated. When an organic solvent is used as the cleaning liquid B, hydrocarbons, ethers, alcohols, polyhydric alcohol derivatives having no OH group and acetate group, which are preferable solvents, are 80% by mass of the total amount of the organic solvent. It is desirable to occupy the above.

In addition, when an organic solvent is used as the cleaning liquid B, the protective film formed on the wafer surface with the chemical liquid of the present invention may not easily be reduced in water repellency due to the cleaning of the cleaning liquid B.

FIG. 4 shows a schematic diagram when the liquid is held in the recess 4 made water repellent by the protective film forming chemical. The wafer in the schematic diagram of FIG. 4 shows a part of the a-a ′ cross section of FIG. The surface of the concavo-convex pattern is made water-repellent by forming a protective film 10 with the chemical solution. The protective film 10 is held on the wafer surface even when the liquid 9 is removed from the concavo-convex pattern.

When the protective film 10 is formed on at least the concave surface of the concave / convex pattern of the wafer with the chemical solution for forming the protective film, the pattern collapses when the contact angle is 50 to 130 ° on the assumption that water is held on the surface. Is preferable because it is difficult to occur. When the contact angle is large, the water repellency is excellent, so 60 to 130 ° is more preferable, and 65 to 130 ° is particularly preferable. In addition, the amount of decrease in the contact angle before and after cleaning with the cleaning liquid B (contact angle before cleaning the cleaning liquid B−contact angle after cleaning the cleaning liquid B) is preferably 10 ° or less.

Next, the liquid held in the recess 4 in which the protective film is formed by the chemical solution is removed from the uneven pattern by drying. At this time, the liquid held in the recess may be the chemical solution, the cleaning solution B, or a mixed solution thereof. The mixed liquid is contained so that each component contained in the protective film forming chemical solution is at a lower concentration than the chemical liquid, and the mixed liquid is in a state of being replaced with the cleaning liquid B. The liquid may be sufficient, and the liquid mixture obtained by mixing each said component with the washing | cleaning liquid B previously may be sufficient. From the viewpoint of the cleanliness of the wafer, water, an organic solvent, or a mixture of water and an organic solvent is preferable. Moreover, after the liquid is once removed from the surface of the concave / convex pattern, the cleaning liquid B may be held on the surface of the concave / convex pattern and then dried.

In the case of cleaning with the cleaning liquid B after the formation of the protective film, the cleaning time, that is, the time for which the cleaning liquid B is held is 10 seconds or more, more preferably 20 from the viewpoint of removing particles and impurities on the uneven pattern surface. It is preferable to carry out for 2 seconds or more. From the viewpoint of the effect of maintaining the water repellency of the protective film formed on the surface of the uneven pattern, when an organic solvent is used as the cleaning liquid B, the water repellency of the wafer surface tends to be easily maintained even after the cleaning. On the other hand, if the washing time is too long, productivity is deteriorated.

The liquid held in the uneven pattern is removed by the above drying. The drying is preferably performed by a known drying method such as a spin drying method, IPA (2-propanol) vapor drying, Marangoni drying, heat drying, hot air drying, air drying, or vacuum drying.

The protective film 10 may be further removed after the drying. When removing the water repellent protective film, it is effective to cut the C—C bond and C—F bond in the water repellent protective film. The method is not particularly limited as long as it can cut the bond, for example, light irradiation of the wafer surface, heating of the wafer, exposure of the wafer to ozone, irradiation of the wafer surface with plasma, For example, corona discharge on the wafer surface may be mentioned.

When removing the protective film 10 by light irradiation, shorter than 340 nm and 240 nm, which are energy equivalent to 83 kcal / mol and 116 kcal / mol, which are binding energy of CC bond and CF bond in the protective film 10 It is preferable to irradiate ultraviolet rays including wavelengths. As this light source, a metal halide lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an excimer lamp, a carbon arc, or the like is used. If the ultraviolet irradiation intensity is a metal halide lamp, for example, measurement with an illuminometer (irradiance intensity meter UM-10 manufactured by Konica Minolta Sensing, light receiving unit UM-360 [peak sensitivity wavelength: 365 nm, measurement wavelength range: 310 to 400 nm]) 100 mW / cm ² or more is preferable in value, 200 mW / cm ² or more is particularly preferable. When the irradiation intensity is less than 100 mW / cm ² , it takes a long time to remove the protective film 10. Further, a low-pressure mercury lamp is preferable because it can irradiate ultraviolet rays having a shorter wavelength, and thus the protective film 10 can be removed in a short time even if the irradiation intensity is low.

Further, when the protective film 10 is removed by light irradiation, if the constituent components of the protective film 10 are decomposed by ultraviolet rays and ozone is generated at the same time, and the constituent components of the protective film 10 are oxidized and volatilized by the ozone, the processing time is shortened. Therefore, it is particularly preferable. As this light source, a low-pressure mercury lamp, an excimer lamp, or the like is used. Further, the wafer may be heated while irradiating light.

When heating the wafer, it is preferable to heat the wafer at 400 to 1000 ° C., preferably 500 to 900 ° C. This heating time is preferably maintained for 10 seconds to 60 minutes, preferably 30 seconds to 10 minutes. In this process, ozone exposure, plasma irradiation, corona discharge, etc. may be used in combination. Further, light irradiation may be performed while heating the wafer.

There are a method of removing the protective film 10 by heating, a method of bringing the wafer into contact with a heat source, and a method of placing the wafer in a heated atmosphere such as a heat treatment furnace. Note that the method of placing the wafer in a heated atmosphere is easy to operate because it is easy to uniformly apply energy for removing the protective film 10 to the wafer surface even when processing a plurality of wafers. This is an industrially advantageous method that requires a short processing time and a high processing capacity.

When the wafer is exposed to ozone, it is preferable that ozone generated by ultraviolet irradiation with a low-pressure mercury lamp or the like or low-temperature discharge with a high voltage is provided on the wafer surface. The wafer may be irradiated with light while being exposed to ozone, or may be heated.

By combining the above light irradiation, heating, ozone exposure, plasma irradiation, and corona discharge, the protective film on the wafer surface can be efficiently removed.

Hereinafter, examples that more specifically disclose the embodiment of the present invention will be shown. In addition, this invention is not limited only to these Examples.

Making the surface of the wafer a surface having a concavo-convex pattern, replacing the cleaning liquid held at least in the concave portion of the concavo-convex pattern with another cleaning liquid, various studies have been made in other literatures, etc. and already established techniques Therefore, in the present invention, the water repellency imparting effect of the chemical solution for forming the protective film and the resistance of the vinyl chloride resin to the chemical solution were evaluated. In the examples, water, which is a typical water-based cleaning liquid, was used as the liquid to be brought into contact with the wafer surface when the contact angle was evaluated.

However, in the case of a wafer having a concavo-convex pattern on the surface, the contact angle of the protective film 10 itself formed on the concavo-convex pattern surface cannot be accurately evaluated.

The contact angle of water droplets is evaluated by dropping several microliters of water droplets on the surface of the sample (base material) as described in JIS R 3257 “Testing method for wettability of substrate glass surface”. It is made by measuring. However, in the case of a wafer having a pattern, the contact angle becomes very large. This is because a Wenzel effect and a Cassie effect occur, and the contact angle is affected by the surface shape (roughness) of the substrate, and the apparent contact angle of water droplets increases.

Therefore, in this embodiment, the above chemical solution is applied to a wafer having a smooth surface, a protective film is formed on the wafer surface, and the protective film is formed on the surface of the wafer having a concavo-convex pattern formed on the surface. Various evaluations were made. In this example, as a wafer having a smooth surface, a “wafer with SiO ₂ film” having a SiO ₂ layer on a silicon wafer having a smooth surface was used.

Details are described below. Hereinafter, an evaluation method, preparation of a protective film forming chemical solution, a wafer cleaning method using the protective film forming chemical solution, and evaluation results will be described.

〔Evaluation methods〕
The following (A) to (C) were evaluated.

(A) Contact angle evaluation of the protective film formed on the wafer surface About 2 μl of pure water is placed on the wafer surface on which the protective film is formed, and the angle (contact angle) formed between the water droplet and the wafer surface is measured by a contact angle meter (Kyowa). It was measured by Interface Science: CA-X type.

(B) Contact angle decrease at the time of water contact The amount of decrease in the contact angle was evaluated when the wafer on which the protective film was formed was immersed in 60 ° C warm water for 10 minutes. A smaller contact angle decrease means that the contact angle is less likely to be reduced by washing after the formation of the protective film, and the decrease is particularly preferably 10 ° or less.

(C) Resistance of the vinyl chloride resin to the chemical solution for forming the protective film In the embodiment of the present invention, whether or not the liquid contact member is deteriorated when the wafer is cleaned by a wafer cleaning apparatus containing the vinyl chloride resin as the liquid contact member. Instead of evaluating, the presence or absence of deterioration of the vinyl chloride resin was evaluated by immersing the vinyl chloride resin in the chemical solution for forming the protective film. Specifically, after immersing a vinyl chloride resin (the surface is glossy) in a chemical solution for forming a protective film and immersing it at 40 ° C. for 4 weeks, the deterioration of the vinyl chloride resin is visually observed, and discoloration, swelling, etc. The presence or absence of deterioration was confirmed. Those with no deterioration were accepted and those with no deterioration were rejected.

[Example 1]
(1) Preparation of chemical solution for forming protective film Trimethylmethoxysilane [(CH ₃ ) ₃ Si—OCH ₃ ] as the raw material alkoxysilane; 10 g, methanesulfonic acid [CH ₃ S (═O) ₂ OH] as the sulfonic acids; 0.5 g and diisoamyl ether [(CH ₃ ) ₂ CHCH ₂ CH ₂ —O—CH ₂ CH ₂ CH (CH ₃ ) ₂ : DiAE]; 89.5 g as a diluent solvent; Obtained.

(2) Cleaning of silicon wafer A silicon wafer with a smooth thermal oxide film (Si wafer having a 1 μm thick thermal oxide film layer on the surface) is immersed in a 1% by mass hydrofluoric acid aqueous solution at room temperature for 10 minutes, and is then added to pure water. It was immersed in 2-propanol (iPA) for 1 minute at room temperature and for 1 minute at room temperature.

(3) Surface treatment of the silicon wafer surface with the chemical solution for forming the protective film The cleaned silicon wafer is added to the protective film forming chemical solution prepared in the above-mentioned “(1) Preparation of the chemical solution for forming the protective film” at room temperature for 2 minutes. It was immersed, and immersed in iPA at room temperature for 1 minute and in pure water at room temperature for 1 minute. Finally, the silicon wafer was taken out from the pure water and air was blown to remove the pure water on the surface.

When the evaluation was performed as described in the above (A) to (C), as shown in Table 1, the initial contact angle before the surface treatment was less than 10 °, but the contact angle after the surface treatment was 76. The water repellency imparting effect was exhibited. Further, the decrease in the contact angle was 2 °, and the ease of maintaining water repellency was good. Furthermore, the resistance of the vinyl chloride resin was good with no change in appearance even after storage at 40 ° C. for 4 weeks.

[Examples 2 to 83]
The surface treatment of the wafer was performed in the same manner as in Example 1 except that the conditions such as the type and concentration of alkoxysilane used in Example 1, the type and concentration of sulfonic acids, the type of dilution solvent, etc. were changed. Evaluation was performed. The results are shown in Tables 1 to 3. In the table, “DnAE” means dinormal amyl ether, “DnHE” means dinormal hexyl ether, “EME” means ethyl methyl ether, “DnDE” means dinormal decyl ether. “DiAE / PGMEA-95” means a mixed solvent of DiAE: PGMEA (propylene glycol monomethyl ether acetate) = 95: 5 by mass ratio, and “DiAE / PGMEA-90” means DiAE: PGMEA = mass ratio 90:10 means a mixed solvent, “DiAE / nHA-95” means a mixed solvent of DiAE: nHA (n-hexanol) = 95: 5 by mass ratio, and “DiAE / ethyl acetate-95” means a mass This means a mixed solvent of DiAE: ethyl acetate = 95: 5 by ratio, and “DiAE / cyclohexanone-95” DiAE: cyclohexanone in a quantitative ratio means a mixed solvent of 95: 5, “decane / PGMEA-95” means a mixed solvent of decane: PGMEA = 95: 5 in a mass ratio, and “decane / nHA-95” means “Decan / nHA-90” means a mixed solvent of decane: nHA = 95: 5 by mass ratio, “decane / nHA-90” means a mixed solvent of decane: nHA = 90: 10 by mass ratio, and “1-dodecanethiol / PGMEA— “95” means a mixed solvent of 1-dodecanethiol: PGMEA = 95: 5 by mass ratio, and “1-dodecanethiol / PGMEA-90” means a mixed solvent of 1-dodecanethiol: PGMEA = 90: 10 by mass ratio. “1-dodecanethiol / nHA-95” means a mixed solvent of 1-dodecanethiol: nHA = 95: 5 by mass ratio, and “1-dodecanethiol” “nHA-90” means a mixed solvent of 1-dodecanethiol: nHA = 90: 10 by mass ratio, and “1-dodecanethiol / ethyl acetate-95” means 1-dodecanethiol: ethyl acetate = 95 by mass ratio. 5, “1-dodecanethiol / cyclohexanone-95” means a mixed solvent of 1-dodecanethiol: cyclohexanone = 95: 5 by mass ratio.

In any of the examples, the initial contact angle before the surface treatment was less than 10 °, which showed the effect of imparting water repellency after the surface treatment. Further, the decrease in contact angle was slight, and the ease of maintaining water repellency was good. Furthermore, the resistance of the vinyl chloride resin was good with no change in appearance even after storage at 40 ° C. for 4 weeks.

In addition, the alkoxysilane used in Example 5 has a structure in which one hydrogen atom is bonded to a silicon atom (that is, a structure in which b in the general formula [1] is 1), and the contact angle is reduced when contacted with water. A tendency was confirmed that the degree was larger than that in Example 4 in which alkoxysilane having a structure in which b in the general formula [1] was 0 was used. Therefore, from the viewpoint of easy maintenance of water repellency after forming the protective film, the number of —H groups (b) of the alkoxysilane represented by the general formula [1] is preferably zero. I understood it.

When Examples 1, 22, and 23 are compared, the smaller the number of carbon atoms of the hydrocarbon group represented by R ¹ in the general formula [1], the larger the contact angle after the surface treatment, and more particularly the methyl group. It was found that a water repellency imparting effect can be obtained.

When Examples 1, 2, and 3 are compared, the contact angles after the surface treatment are in the order of Example 1> Example 2> Example 3 (monoalkoxysilane> dialkoxysilane> trialkoxysilane). From the viewpoint of the effect, it was found that monoalkoxysilane is preferable. The same tendency can be confirmed from the comparison of Examples 40, 41, and 42.

When Examples 8 and 12 were compared, it was found that a better water repellency imparting effect can be obtained when R ^{3 in the} general formula [2] is a perfluoroalkyl group. Moreover, Examples 17, 24 and 25 using sulfonic acid in which R ³ in the general formula [2] is a perfluoroalkyl group all showed excellent water repellency imparting effects.

In Example 26, the sulfonic acid anhydride used in Example 17 was used as the sulfonic acid, and an excellent water repellency imparting effect was exhibited.

In Example 27, a sulfonic acid derivative in which the —OH group of trifluoromethanesulfonic acid was replaced with —OSi (CH ₃ ) ₃ group was used as the sulfonic acid, and an excellent water repellency imparting effect was shown.

In Examples 29 to 32, two kinds of sulfonic acids, trifluoromethanesulfonic acid and the sulfonic acid derivative used in Example 27, were used, and excellent water repellency imparting effects were exhibited. Furthermore, in Example 33, two kinds of sulfonic acid anhydrides used in Example 26 and sulfonic acid derivatives used in Example 27 were used as sulfonic acids, and an excellent water repellency imparting effect was shown. .

Examples 12, 13, and 14 using DiAE, DnAE, and DnHE, respectively, as dilution solvents were all good evaluation results. In addition, Example 15 using EME as a diluent solvent was a good evaluation result. However, since the dilution solvent has high volatility, it was necessary to prepare the solution while cooling in order to suppress concentration change due to solvent volatilization. It was. Moreover, although Example 16 using DnDE as a diluent solvent was a good evaluation result, the stirring time for obtaining a uniform chemical solution for forming a water-repellent protective film tends to be long because the viscosity of the diluent solvent is high. there were.

Examples 17, 18, and 19 using decane, dodecane, and decalin as dilution solvents were all good evaluation results. In addition, Example 20 using pentane as a diluent solvent was a good evaluation result. However, since the dilution solvent has high volatility, it was necessary to prepare the solution while cooling in order to suppress the concentration change due to solvent volatilization. It was. Moreover, although Example 21 using pentadecane as a diluent solvent was a good evaluation result, the viscosity of the diluent solvent is high, and thus the stirring time for obtaining a uniform chemical solution for forming a water-repellent protective film tends to be longer. there were.

Further, Examples 43 to 69 using thiol as a diluent solvent had the same tendency as described above.

In Examples 70 to 83 using a mixed solvent as a diluting solvent, the evaluation results were all good.

[Examples 84 to 89]
The chemical solutions of Examples 84 and 85 are chemical solutions obtained by adding 1-dodecanethiol as the other additive to the chemical solutions of Examples 17 and 75 to a concentration of 1% by mass, respectively. Both were good evaluation results. In addition, the chemical solutions of Examples 86 and 87 were added to the chemical solutions of Example 17 and Example 75, respectively, so that BHT (dibutylhydroxytoluene) was added at a concentration of 0.1% by mass as another additive. The obtained chemical solution was a good evaluation result. Furthermore, the chemical solutions of Examples 88 and 89 were added to the chemical solutions of Example 17 and Example 75, respectively with tert-butylxylenol (6-tert-butyl-2,4-xylenol) as the other additive. It was a chemical solution obtained by adding so as to have a concentration of mass%, and both were good evaluation results. The results are shown in Table 4.

[Example 90]
(Preparation of the first solution)
10 g of trimethylmethoxysilane as an alkoxysilane; 40 g of diisoamyl ether as a diluting solvent were mixed to obtain a first liquid.
(Preparation of the second liquid)
Sulfonic acid derivative [CF ₃ S (═O) ₂ O—Si (CH ₃ ) ₃ ] in which —OH group of trifluoromethanesulfonic acid is replaced by —OSi (CH ₃ ) ₃ group as sulfonic acids; 0.5 g, diluted 49.5 g of diisoamyl ether as a solvent was mixed to obtain a second liquid.
Example 1 was the same as Example 1 except that the first liquid and the second liquid were mixed to obtain a protective film forming chemical.

When the evaluation was performed in the manner described in (A) to (C) above, as shown in Table 5, the initial contact angle before the surface treatment was less than 10 °, but the contact angle after the surface treatment was 87. The water repellency imparting effect was exhibited. Further, the decrease in the contact angle was 0 °, and the ease of maintaining water repellency was good. Furthermore, the resistance of the vinyl chloride resin was good with no change in appearance even after storage at 40 ° C. for 4 weeks.

[Examples 91 to 94]
The surface treatment of the wafer was performed in the same manner as in Example 90 except that the conditions such as the type and concentration of alkoxysilane used in Example 90, the concentration of sulfonic acids, the type of dilution solvent, etc. were changed. went. The results are shown in Table 5.

[Comparative Examples 1 to 12]
As shown in Table 6, the surface treatment of the wafer was performed in the same manner as in Example 1 except that the conditions such as the type and concentration of the sulfonic acids and the type of the dilution solvent were changed, and the evaluation was further performed.
In Comparative Example 1, a protective film-forming chemical solution containing no sulfonic acid was used. The contact angle after the surface treatment was as low as less than 10 °, and no water repellency imparting effect was observed.
Comparative Example 2 was an example in which the dilution solvent of Comparative Example 1 was changed to DiAE, and the evaluation results were the same as Comparative Example 1. Comparative Example 3 was an example in which the diluent solvent of Comparative Example 1 was changed to 1-dodecanethiol, and the evaluation results were the same as Comparative Example 1.
Comparative Examples 4 to 12 are examples using a water-repellent protective film-forming chemical solution in which the total amount of hydrocarbon, ether, and thiol was 70% by mass with respect to the total amount of dilution solvent of 100% by mass. In the evaluation of the resistance of the vinyl resin to the chemical solution for forming a protective film, the vinyl chloride resin was confirmed to swell after storage, and thus was rejected.

DESCRIPTION OF SYMBOLS 1 Wafer 2 Fine uneven | corrugated pattern on the wafer surface 3 Pattern convex part 4 Pattern concave part 5 Concave width 6 Convex height 7 Convex width 8 The protective film forming chemical 9 held in the concave part 4 In the concave part 4 Retained liquid 10 protective film

Claims

In a method for cleaning a wafer having a fine concavo-convex pattern on the surface with a wafer cleaning apparatus containing a vinyl chloride resin as a liquid contact member and at least a part of the concavo-convex pattern containing silicon element,
An alkoxysilane represented by the following general formula [1], a sulfonic acid represented by the following general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a general formula [3] At least one selected from the group consisting of sulfonic acid derivatives
As well as a diluent solvent,
The dilution solvent includes at least one solvent selected from the group consisting of hydrocarbon, ether, and thiol, and the total amount of the hydrocarbon, ether, and thiol is 100% by mass of the total amount of the dilution solvent. A method for cleaning a wafer, comprising holding a chemical solution for forming a water-repellent protective film in an amount of 80 to 100% by mass in at least a concave portion of the concave-convex pattern to form a water-repellent protective film on the concave surface.
(R 1 ) a Si (H) b (OR 2 ) 4-ab [1]
[In the formula [1], each R 1 is independently selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. At least one group, and R 2 is each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a and b is 3 or less. ]
R 3 —S (═O) 2 OH [2]
[In the formula [2], R 3 is selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced with fluorine elements, and hydroxyl groups. Group. ]
R 3 —S (═O) 2 O—Si (H) 3 -c (R 4 ) c [3]
[In the formula [3], R 3 is a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R 4 are each Independently, at least one group selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced with fluorine elements, and c is 1 to 3 Is an integer. ]
The wafer cleaning method according to claim 1, wherein the sulfonic acid is at least one selected from the group consisting of sulfonic acids represented by the following general formula [4].
R 5 —S (═O) 2 OH [4]
[In the formula [4], R 5 is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. . ]
2. The wafer cleaning method according to claim 1, wherein the sulfonic acid anhydride is at least one selected from the group consisting of sulfonic acid anhydrides represented by the following general formula [4].
R 5 —S (═O) 2 OH [4]
[In the formula [4], R 5 is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. . ]
The wafer cleaning according to claim 1, wherein the sulfonic acid salt is at least one selected from the group consisting of an ammonium salt and an alkylamine salt of a sulfonic acid represented by the following general formula [4]. Method.
R 5 —S (═O) 2 OH [4]
[In the formula [4], R 5 is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. . ]
The wafer cleaning method according to claim 1, wherein the sulfonic acid derivative is at least one selected from the group consisting of sulfonic acid derivatives represented by the following general formula [5].
R 6 —S (═O) 2 O—Si (CH 3 ) 2 (R 7 ) [5]
[In the formula [5], R 6 is a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R 7 is a part of Alternatively, it is a monovalent hydrocarbon group having 1 to 18 carbon atoms in which all hydrogen elements may be replaced with fluorine elements. ]
6. The wafer cleaning method according to claim 1, wherein the hydrocarbon is a hydrocarbon having 6 to 13 carbon atoms.
The wafer cleaning method according to claim 1, wherein the ether is an ether represented by the following general formula [6].
R 8 —O—R 9 [6]
[In the formula [6], R 8 and R 9 are each independently a monovalent carbon atom having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. It is a hydrogen group, and the total number of carbon atoms of R 8 and R 9 is 4 to 16. ]
The wafer cleaning method according to any one of claims 1 to 7, wherein the thiol is a thiol having 6 to 13 carbon atoms.
The wafer cleaning method according to any one of claims 1 to 8, wherein the alkoxysilane is at least one selected from the group consisting of alkoxysilanes represented by the following general formula [7].
(R 10 ) d Si (OR 11 ) 4-d [7]
[In the formula [7], R 10 s are each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, R 11 Are each independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, and d is 2 or 3. ]
10. The wafer cleaning method according to claim 1, wherein the alkoxysilane is at least one selected from the group consisting of monoalkoxysilanes represented by the following general formula [8].
R 10 —Si (CH 3 ) 2 (OR 11 ) [8]
[In the formula [8], R 10 is a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R 11 is 1 carbon atom. Is a monovalent hydrocarbon group of ˜12. ]
11. The wafer cleaning method according to claim 1, wherein the concentration of the alkoxysilane in the water repellent protective film forming chemical is 0.5 to 35% by mass.
The concentration of the total amount of the sulfonic acid, the sulfonic acid anhydride, the sulfonic acid salt, and the sulfonic acid derivative in the water repellent protective film-forming chemical solution is 0.0001 to 5 mass%. The wafer cleaning method according to any one of 1 to 11.
After holding the water repellent protective film forming chemical in at least the recesses of the concave / convex pattern and forming the water repellent protective film on the concave surfaces, the water repellent protective film forming chemical is removed from the recesses by drying. The method for cleaning a wafer according to any one of claims 1 to 12.
After holding the water repellent protective film forming chemical in at least the recesses of the concave / convex pattern and forming the water repellent protective film on the surface of the concaves, the water repellent protective film forming chemical is different from the chemicals. The method for cleaning a wafer according to claim 1, wherein the cleaning liquid is replaced with a cleaning liquid, and the cleaning liquid is removed from the recesses by drying.
The wafer surface after the drying is subjected to at least one treatment selected from the group consisting of heat treatment, light irradiation treatment, ozone exposure treatment, plasma irradiation treatment, and corona discharge treatment to remove the water-repellent protective film. Item 15. A method for cleaning a wafer according to Item 13 or 14.
at least,
Containing an alkoxysilane represented by the general formula [1], or
A diluting solvent containing an alkoxysilane represented by the general formula [1] and at least one solvent selected from the group consisting of hydrocarbons, ethers, and thiols,
The first liquid,
At least one selected from the group consisting of a sulfonic acid represented by the general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a sulfonic acid derivative represented by the general formula [3]. Including or
At least one selected from the group consisting of a sulfonic acid represented by the general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a sulfonic acid derivative represented by the general formula [3]; A diluting solvent comprising at least one solvent selected from the group consisting of: hydrocarbons, ethers, and thiols,
A second liquid,
The step of obtaining the water repellent protective film forming chemical solution by mixing a water repellent protective film forming chemical solution kit in which at least one of the first liquid and the second liquid contains the dilution solvent is provided. The wafer cleaning method according to any one of the above.
Used when cleaning a wafer having a fine concavo-convex pattern on the surface with a wafer cleaning apparatus containing a vinyl chloride resin as a liquid contact member and at least a part of the concavo-convex pattern containing a silicon element.
An alkoxysilane represented by the following general formula [1], a sulfonic acid represented by the following general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a general formula [3] At least one selected from the group consisting of sulfonic acid derivatives
As well as a diluent solvent,
The dilution solvent includes at least one solvent selected from the group consisting of hydrocarbon, ether, and thiol, and the total amount of the hydrocarbon, ether, and thiol is 100% by mass of the total amount of the dilution solvent. A chemical solution for forming a water-repellent protective film, comprising 80 to 100% by mass.
(R 1 ) a Si (H) b (OR 2 ) 4-ab [1]
[In the formula [1], each R 1 is independently selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. At least one group, and R 2 is each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a and b is 3 or less. ]
R 3 —S (═O) 2 OH [2]
[In the formula [2], R 3 is selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced with fluorine elements, and hydroxyl groups. Group. ]
R 3 —S (═O) 2 O—Si (H) 3 -c (R 4 ) c [3]
[In the formula [3], R 3 is a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R 4 are each Independently, at least one group selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced with fluorine elements, and c is 1 to 3 Is an integer. ]
The water-repellent protective film-forming chemical solution according to claim 17, wherein the sulfonic acid is at least one selected from the group consisting of sulfonic acids represented by the following general formula [4].
R 5 —S (═O) 2 OH [4]
[In the formula [4], R 5 is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. . ]
The water-repellent protective film-forming chemical solution according to claim 17, wherein the sulfonic acid anhydride is at least one selected from the group consisting of sulfonic acid anhydrides represented by the following general formula [4].
R 5 —S (═O) 2 OH [4]
[In the formula [4], R 5 is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. . ]
The water-repellent protection according to claim 17, wherein the salt of the sulfonic acid is at least one selected from the group consisting of an ammonium salt and an alkylamine salt of a sulfonic acid represented by the following general formula [4]. Chemical solution for film formation.
R 5 —S (═O) 2 OH [4]
[In the formula [4], R 5 is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. . ]
The water-repellent protective film-forming chemical solution according to claim 17, wherein the sulfonic acid derivative is at least one selected from the group consisting of sulfonic acid derivatives represented by the following general formula [5].
R 6 —S (═O) 2 O—Si (CH 3 ) 2 (R 7 ) [5]
[In the formula [5], R 6 is a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R 7 is a part of Alternatively, it is a monovalent hydrocarbon group having 1 to 18 carbon atoms in which all hydrogen elements may be replaced with fluorine elements. ]
The chemical solution for forming a water-repellent protective film according to any one of claims 17 to 21, wherein the hydrocarbon is a hydrocarbon having 6 to 13 carbon atoms.
The chemical solution for forming a water-repellent protective film according to any one of claims 17 to 22, wherein the ether is an ether represented by the following general formula [6].
R 8 —O—R 9 [6]
[In the formula [6], R 8 and R 9 are each independently a monovalent carbon atom having 1 to 8 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements. It is a hydrogen group, and the total number of carbon atoms of R 8 and R 9 is 4 to 16. ]
The chemical solution for forming a water-repellent protective film according to any one of claims 17 to 23, wherein the thiol is a thiol having 6 to 13 carbon atoms.
The chemical solution for forming a water repellent protective film according to any one of claims 17 to 24, wherein the alkoxysilane is at least one selected from the group consisting of alkoxysilanes represented by the following general formula [7].
(R 10 ) d Si (OR 11 ) 4-d [7]
[In the formula [7], R 10 s are each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, R 11 Are each independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, and d is 2 or 3. ]
The chemical solution for forming a water-repellent protective film according to any one of claims 17 to 25, wherein the alkoxysilane is at least one selected from the group consisting of monoalkoxysilanes represented by the following general formula [8].
R 10 —Si (CH 3 ) 2 (OR 11 ) [8]
[In the formula [8], R 10 is a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen elements may be replaced by fluorine elements, and R 11 is 1 carbon atom. Is a monovalent hydrocarbon group of ˜12. ]
The chemical solution for forming a water-repellent protective film according to any one of claims 17 to 26, wherein the concentration of the alkoxysilane in the chemical solution for forming a water-repellent protective film is 0.5 to 35% by mass.
The concentration of the total amount of the sulfonic acid, the sulfonic acid anhydride, the sulfonic acid salt, and the sulfonic acid derivative in the water repellent protective film-forming chemical solution is 0.0001 to 5 mass%. 28. The chemical solution for forming a water-repellent protective film according to any one of 17 to 27.
A water repellent protective film forming chemical solution kit for obtaining the water repellent protective film forming chemical solution according to any one of claims 17 to 28 by mixing,
at least,
Containing an alkoxysilane represented by the general formula [1], or
A diluting solvent containing an alkoxysilane represented by the general formula [1] and at least one solvent selected from the group consisting of hydrocarbons, ethers, and thiols,
The first liquid,
At least one selected from the group consisting of a sulfonic acid represented by the general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a sulfonic acid derivative represented by the general formula [3]. Including or
At least one selected from the group consisting of a sulfonic acid represented by the general formula [2], an anhydride of the sulfonic acid, a salt of the sulfonic acid, and a sulfonic acid derivative represented by the general formula [3]; A diluting solvent comprising at least one solvent selected from the group consisting of: hydrocarbons, ethers, and thiols,
A second liquid,
A chemical kit for forming a water-repellent protective film, wherein at least one of the first liquid and the second liquid contains the dilution solvent.