Biochips or microfluidic chips

Abstract

To provide a novel photosensitive composition which can form a developed film having high water repellency and has good developability.SOLUTION: The photosensitive composition of the present invention contains: a polymer containing a constituent unit represented by the following formula (1); and at least one selected from the group consisting of photoacid generators and photobase generators. [In the formula (1), Rff1-Rff4 each independently represent a fluorine atom, a C1-7 perfluoroalkyl group or a C1-7 perfluoroalkyl ether group; and Rff1 and Rff2 may be linked together to form a ring.]SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a photosensitive composition, a device, and a method for manufacturing the device. [Background technology]

[0002] Photolithography has been known as a technique for forming a pattern on a photosensitive film formed from a photosensitive composition. In photolithography, a pattern can be formed on a photosensitive film by exposing the photosensitive film to light in a pattern and then developing the photosensitive film. In this specification, a photosensitive film that has been subjected to a development process may be referred to as a "developed film."

[0003] Photolithography techniques are also used to fabricate devices such as biochips, microchannel chips, etc. For example, Patent Document 1 discloses a photosensitive composition for fabricating biochips using photolithography techniques. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-102159 Summary of the Invention [Problem to be solved by the invention]

[0005] Depending on the field in which the device is used, the developed film is required to have high water repellency, and further, the photosensitive composition for forming the developed film is required to have good developability.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a novel photosensitive composition which can form a developed film having high water repellency and has good developability. [Means for solving the problem]

[0007] The present invention provides A polymer containing a structural unit represented by the following formula (1): at least one selected from the group consisting of a photoacid generator and a photobase generator; The present invention provides a photosensitive composition comprising: [ka] [In formula (1), R ff 1 ~R ff 4 R each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms. ff 1 and R ff 2 may be linked to form a ring.

[0008] Furthermore, the present invention provides A substrate; a water-repellent film disposed on the substrate and having an opening; The device has a water-repellent film comprising a polymer containing a constitutional unit represented by the following formula (1): [ka] [In formula (1), R ff 1 ~R ff 4 R each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms. ff 1 and R ff 2 may be linked to form a ring. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a novel photosensitive composition that can form a developed film having high water repellency and has good developability. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a cross-sectional view showing an example of a device. [Figure 2A] FIG. 1 is a diagram showing a state in which a photosensitive film is disposed on a substrate. [Figure 2B] 2B is a diagram showing a state in which a part of the photosensitive film of FIG. 2A is exposed to light. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described, but the following description is not intended to limit the present invention to any particular embodiment.

[0012] [Photosensitive composition] The photosensitive composition of the present embodiment contains a polymer (P) containing a structural unit (A) represented by the following formula (1), and at least one selected from the group consisting of a photoacid generator and a photobase generator. [ka]

[0013] In formula (1), R ff 1 ~R ff 4 R each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms. ff 1 and R ff 2 may be linked to form a ring. "Perfluoro" means that all hydrogen atoms bonded to carbon atoms are substituted with fluorine atoms. In formula (1), the number of carbon atoms in the perfluoroalkyl group is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. The perfluoroalkyl group may be linear or branched. Examples of perfluoroalkyl groups include a trifluoromethyl group, a pentafluoroethyl group, and a heptafluoropropyl group.

[0014] In formula (1), the number of carbon atoms in the perfluoroalkyl ether group is preferably 1 to 5, and more preferably 1 to 3. The perfluoroalkyl ether group may be linear or branched. Examples of the perfluoroalkyl ether group include a perfluoromethoxymethyl group.

[0015] R ff 1 and R ff 2 When these are linked to form a ring, the ring may be a 5-membered ring or a 6-membered ring. Examples of this ring include a perfluorotetrahydrofuran ring, a perfluorocyclopentane ring, and a perfluorocyclohexane ring.

[0016] Specific examples of the structural unit (A) include structural units represented by the following formulas (A1) to (A8). [ka]

[0017] Of the structural units represented by the above formulas (A1) to (A8), the structural unit (A) is preferably the structural unit (A2), ie, the structural unit represented by the following formula (2). [ka]

[0018] The structural unit (A) is derived from, for example, a compound represented by the following formula (3): ff 1 ~R ff 4 is the same as equation (1). [ka]

[0019] Specific examples of the compound represented by the above formula (3) include compounds represented by the following formulae (M1) to (M8). [ka]

[0020] The polymer (P) may contain one or more types of structural unit (A). The polymer (P) contains, for example, the structural unit (A) as a main component. In this specification, "main component" means the structural unit that is contained in the polymer (P) in the largest amount on a molar basis. The content of the structural unit (A) in the polymer (P) is, for example, 80 mol% or more, preferably 90 mol% or more, and more preferably 95 mol% or more. The polymer (P) is, for example, substantially composed of the structural unit (A).

[0021] The polymer (P) may further contain a structural unit (B) other than the structural unit (A). Examples of compounds that form the structural unit (B) include fluorine-containing olefin compounds such as tetrafluoroethylene and chlorotrifluoroethylene; perfluorovinyl ether compounds such as perfluoropropyl vinyl ether; and fluorine-containing compounds that have two or more polymerizable double bonds and are capable of cyclopolymerization, such as perfluoroallyl vinyl ether and perfluorobutenyl vinyl ether.

[0022] The polymer (P) preferably contains substantially no hydrogen atoms, and is more preferably perfluorinated from the viewpoint of improving the water repellency of the developed film formed from the photosensitive composition. "The polymer is perfluorinated" means that in the polymer, all hydrogen atoms bonded to carbon atoms are substituted with fluorine atoms. As far as the inventors know, there has been no example of using a perfluorinated polymer in a photosensitive composition.

[0023] The polymerization method for the polymer (P) is not particularly limited, and for example, a general polymerization method such as radical polymerization can be used. The polymerization initiator for polymerizing the polymer (P) may be a perfluorinated compound.

[0024] The weight average molecular weight of the polymer (P) is, for example, 5,000 to 1,000,000. The glass transition temperature (Tg) of the polymer (P) is, for example, 100°C to 150°C. In this specification, Tg refers to the midpoint glass transition temperature (T mg ) means

[0025] The content of the polymer (P) in the photosensitive composition is, for example, 1 wt % or more, and preferably 5 wt % or more. The content of the polymer (P) may be 99.9 wt % or less, or may be 80 wt % or less.

[0026] The photosensitive composition of this embodiment preferably contains one of a photoacid generator and a photobase generator, and more preferably contains a photoacid generator. The photoacid generator is not particularly limited as long as it is a compound that generates an acid when irradiated with light of a specific wavelength, and examples thereof include triarylsulfonium salts, diaryliodonium salts, and sulfonyldiazomethane.

[0027] Examples of cations contained in triarylsulfonium salts include triphenylsulfonium, diphenyl-4-methylphenylsulfonium, tris(4-methylphenyl)sulfonium, diphenyl-2,4,6-trimethylphenylsulfonium, and 4-(phenylthio)phenyldiphenylsulfonium. Examples of anions contained in triarylsulfonium salts include trifluoromethanesulfonate, nonafluorobutanesulfonate, hexafluorophosphate, tetrafluoroborate, tris(pentafluoroethyl)trifluorophosphate, tris(heptafluoropropyl)trifluorophosphate, tris(nonafluoroisobutyl)trifluorophosphate, and bis(nonafluoroisobutyl)tetrafluorophosphate.

[0028] Examples of cations contained in diaryliodonium salts include diphenyliodonium, 4-isopropyl-4'-methyldiphenyliodonium, 4-methyl-4'-methylpropyldiphenyliodonium, bis(4-tert-butylphenyl)iodonium, and 4-methoxyphenylphenyliodonium. Examples of anions contained in diaryliodonium salts include those described above for triarylsulfonium salts.

[0029] Examples of sulfonyldiazomethanes include bis(phenylsulfonyl)diazomethane, bis(tert-butylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, and bis(p-toluenesulfonyl)diazomethane.

[0030] The photoacid generator is preferably tris(4-methylphenyl)sulfonium nonafluorobutanesulfonate, 4-(phenylthio)phenyldiphenylsulfonium tris(heptafluoropropyl)trifluorophosphate, 4-(phenylthio)phenyldiphenylsulfonium tris(nonafluoroisobutyl)trifluorophosphate, 4-(phenylthio)phenyldiphenylsulfonium bis(nonafluoroisobutyl)tetrafluorophosphate, 4-(phenylthio)phenyldiphenylsulfonium (pentafluoroethyl)trifluorophosphate, diphenyl-2,4,6-trimethylphenylsulfonium trifluoromethanesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium nonafluorobutanesulfonate, bis(phenylsulfonyl)diazomethane, or bis(p-toluenesulfonyl)diazomethane. The photoacid generator may be IRGACURE (registered trademark) 250 manufactured by BASF, CPI (registered trademark)-100P or CPI (registered trademark)-210S manufactured by San-Apro Co., Ltd., or WPAG-638 or WPAG-199 manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. The photosensitive composition of the present embodiment may contain one or more photoacid generators.

[0031] The photobase generator is not particularly limited as long as it is a compound that generates a base when irradiated with light of a specific wavelength. Examples of the photobase generator include N-cyclohexylcarbamic acid 1-(anthraquinone-2-yl)ethyl, N,N-diethylcarbamic acid 9-anthrylmethyl, piperidine-1-carboxylic acid 9-anthrylmethyl, N,N-dicyclohexylcarbamic acid 9-anthrylmethyl, N,N-dicyclohexylcarbamic acid 1-(anthraquinone-2-yl)ethyl, imidazole-1-carboxylic acid 1-(anthraquinone-2-yl)ethyl, cyclohexylammonium 2-(3-benzoylphenyl)propionate, (E)-N-cyclohexyl-3-(2-hydroxyphenyl)acrylamide, and dicyclohexylammonium. Examples of suitable photobase generators include 2-(3-benzoylphenyl)propionate, 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium n-butyltriphenylborate, 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidium 2-(3-benzoylphenyl)propionate, 4-hydroxypiperidine-1-carboxylate (2-nitrophenyl)methyl, 4-(methacryloyloxy)piperidine-1-carboxylate (2-nitrophenyl)methyl, guanidium 2-(3-benzoylphenyl)propionate, and (E)-1-piperidino-3-(2-hydroxyphenyl)-2-propen-1-one. Examples of suitable photobase generators include the WPBG series manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. The photosensitive composition of this embodiment may contain one or more photobase generators.

[0032] The content of the photoacid generator in the photosensitive composition is, for example, 0.1 wt% to 10 wt%, and preferably 1 wt% to 5 wt%. The content of the photobase generator in the photosensitive composition is, for example, 0.1 wt% to 10 wt%, and preferably 1 wt% to 5 wt%.

[0033] The photosensitive composition of the present embodiment may or may not further contain components other than the polymer (P), the photoacid generator, and the photobase generator, such as a polymer other than the polymer (P), a solvent, a photosensitizer, an antioxidant, an adhesion promoter, a leveling agent, an antifoaming agent, a suspending agent, a dispersant, a plasticizer, and a thickener.

[0034] The solvent contained in the photosensitive composition is preferably one that dissolves or disperses the polymer (P), the photoacid generator, and the photobase generator. Examples of the solvent include 1H-tridecafluorohexane (manufactured by Asahi Glass Co., Ltd., Asahiklin (registered trademark) AC2000), 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorooctane (manufactured by Asahi Glass Co., Ltd., Asahiklin (registered trademark) AC6000), 1,1,2,2-tetrafluoro-1-(2,2,2-trifluoroethoxy)ethane (manufactured by Asahi Glass Co., Ltd., Asahiklin (registered trademark) AE3000), and dichloropentafluoropropane (manufactured by Asahi Glass Co., Ltd., Asahiklin (registered trademark) AK-22 5), 1,1,1,2,3,4,4,5,5,5-decafluoro-3-methoxy-2-(trifluoromethyl)pentane (manufactured by Asahi Glass Co., Ltd., Cytop (registered trademark) CT-solv100E), 1-methoxynonafluorobutane (manufactured by 3M Japan, Novec (registered trademark) 7100), 1-ethoxynonafluorobutane (manufactured by 3M Japan, Novec (registered trademark) 7200), perfluorohexyl methyl ether (manufactured by 3M Japan, Novec (registered trademark) 7300), 1, 1,1,2,3,3-Hexafluoro-4-(1,1,2,3,3,3-hexafluoropropoxy)pentane (Novec® 7600, manufactured by 3M Japan), 2H,3H-perfluoropentane (Vertrel® XF, manufactured by Mitsui-Chemours Fluorochemicals), 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-1-octanol, 4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluoro-1-nonanol, hexafluoro fluorine-containing compounds such as chlorobenzene, hexafluoro-2-propanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, and 1H,1H,7H-dodecafluoro-1-heptanol, as well as other commercially available fluorine-based solvents (for example, Fluorinert (registered trademark) FC-770 manufactured by 3M Japan and Cerefhin (registered trademark) 1233Z manufactured by Central Glass Co., Ltd.); non-fluorine-containing ketones such as cyclopentanone, cyclohexanone, methyl amyl ketone, and 2-butanone;Examples of the solvent include esters such as ethyl lactate, methyl benzoate, ethyl benzoate, benzyl benzoate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol methyl ethyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene carbonate; and ethers such as diethylene glycol methyl ethyl ether, tetrahydrofuran, dioxane, dimethoxyethane, diethoxyethane, anisole, diglyme, and triglyme. The photosensitive composition may contain one or more of these solvents. From the viewpoints of the solubility of the components contained in the photosensitive composition and the film-forming properties of the photosensitive composition, preferred solvents are propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol methyl ethyl ether, hexafluoro-2-propanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, and 1H,1H,7H-dodecafluoro-1-heptanol;

[0035] The content of the solvent in the photosensitive composition is, for example, 98.9 wt% or less, and preferably 94 wt% or less. The lower limit of the solvent content is not particularly limited and is, for example, 15 wt%. The photosensitive composition may not contain a solvent.

[0036] [device] As shown in Fig. 1, the device 10 of this embodiment includes a substrate 1 and a water-repellent film 2. The water-repellent film 2 is disposed on the substrate 1 and is in contact with the substrate 1. As will be described later, the water-repellent film 2 is a developed film obtained by developing a photosensitive film made from the above-mentioned photosensitive composition. Therefore, the water-repellent film 2 contains the above-mentioned polymer (P).

[0037] The water-repellent film 2 has an opening 5, and the opening 5 exposes, for example, a part of the surface of the substrate 1. The water-repellent film 2 may have a plurality of openings 5. The openings 5 ​​penetrate the water-repellent film 2 in the thickness direction. The openings 5 ​​may have the shape of a hole or a groove. When the openings 5 ​​have the shape of a hole, the openings 5 ​​have, for example, a circular shape in a plan view. In the water-repellent film 2, one or more openings 5 ​​may be formed in a predetermined pattern.

[0038] When the openings 5 ​​have a circular shape in a planar view, the diameter of the openings 5 ​​is, for example, 1 to 1000 μm, and preferably 10 to 500 μm. When the openings 5 ​​have a groove shape, the width of the openings 5 ​​is, for example, 1 to 2000 μm, and preferably 10 to 1000 μm. When the water-repellent film 2 has a plurality of openings 5, the distance between two adjacent openings 5 ​​is, for example, 1 to 2000 μm, preferably 1 to 1000 μm, more preferably 10 to 1000 μm, and even more preferably 10 to 500 μm.

[0039] The thickness of the water-repellent film 2 is not particularly limited, and is, for example, 0.01 to 100 μm, and preferably 0.1 to 50 μm.

[0040] Examples of the substrate 1 include a glass plate, a thermoplastic plastic sheet including polypropylene, polyethylene, polycarbonate, polymethyl methacrylate, polystyrene, polyimide, polyamideimide, polyamide, etc., a silicon wafer, a metal plate including stainless steel (SUS), aluminum, etc., and a laminate of a metal foil such as copper foil and a resin substrate. From the viewpoint of heat resistance, the substrate 1 is preferably a glass plate, particularly a quartz glass plate.

[0041] The composition of the water-repellent film 2 is the same as that of the above-mentioned photosensitive composition, except that it contains almost no solvent. The water-repellent film 2 contains, for example, at least one selected from the group consisting of the above-mentioned photoacid generators and photobase generators in addition to the polymer (P).

[0042] The content of the polymer (P) in the water-repellent film 2 is, for example, 1 wt% or more, and preferably 5 wt% or more. The content of the polymer (P) in the water-repellent film 2 may be 99.9 wt% or less, or may be 80 wt% or less. The content of the photoacid generator in the water-repellent film 2 is, for example, 0.1 wt% to 10 wt%, and preferably 1 wt% to 5 wt%. The content of the photobase generator in the water-repellent film 2 is, for example, 0.1 wt% to 10 wt%, and preferably 1 wt% to 5 wt%.

[0043] The water-repellent film 2 has high water repellency due to the inclusion of the polymer (P). The contact angle of the water-repellent film 2 with water is, for example, 60 degrees or more, preferably 90 degrees or more. The upper limit of the contact angle of the water-repellent film 2 with water is not particularly limited and may be, for example, 130 degrees or 110 degrees. The contact angle of the water-repellent film 2 can be measured in accordance with the "sessile drop method" specified in JIS R3257:1999. Specifically, the contact angle of the water-repellent film 2 can be measured by the following method. First, a syringe equipped with a needle is held in a position where the tip of the needle does not contact the water-repellent film 2. A 2 μL droplet (a droplet of distilled water) is dispensed from the tip of the needle, and with the droplet held at the tip of the needle, the syringe is lowered to bring the droplet into contact with the water-repellent film 2. The syringe is then raised, and only the droplet is placed on the film, and the contact angle of the droplet is measured using a commercially available contact angle meter.

[0044] The device 10 having the water-repellent film 2 is suitable for use as a biochip, a microchannel chip, etc. A specific example of a microchannel chip is a microreactor. As an example, the device 10 of this embodiment can be used as a biochip.

[0045] Next, a method for manufacturing the device 10 will be described. First, as shown in FIG. 2A, the above-described photosensitive composition is applied to a substrate 1 to form a photosensitive film 3. The method for applying the photosensitive composition to the substrate 1 is not particularly limited, and examples thereof include spraying, roll coating, spin coating, and bar coating. The photosensitive film 3 can be produced, for example, by applying the photosensitive composition to the substrate 1 and then drying the photosensitive composition. The drying conditions for the photosensitive composition are not particularly limited, and the photosensitive composition may be dried, for example, by heating the photosensitive composition. The photosensitive composition may be heated, for example, at a temperature of 50°C to 120°C for 10 to 2000 seconds. The thickness of the photosensitive film 3 is, for example, the same as that of the water-repellent film 2.

[0046] Next, a portion of the photosensitive film 3 is exposed. For example, the following method can be used to expose a portion of the photosensitive film 3. First, as shown in FIG. 2B , a mask 20 is placed on the photosensitive film 3. The mask 20 has openings 25, and a portion of the surface of the photosensitive film 3 is exposed through the openings 25. Next, light is irradiated onto the surface of the mask 20 from a light source 30. This allows the surface of the photosensitive film 3 exposed through the openings 25 of the mask 20 to be exposed. The light irradiated from the light source 30 can be selected depending on the type of photoacid generator or photobase generator contained in the photosensitive film 3, and is, for example, at least one selected from the group consisting of ultraviolet light, visible light, infrared light, an electron beam, and radiation, and preferably includes ultraviolet light. The wavelength of the light irradiated from the light source 30 is, for example, 100 to 500 nm, preferably 200 to 450 nm, and more preferably 365 nm. The exposure dose of the light irradiated from the light source 30 is, for example, 5 to 10,000 mJ / cm. 2 The light source 30 may be, for example, a semiconductor light emitting element, preferably a light emitting diode (LED), a superluminescent diode (SLD), or a laser diode (LD). The light source 30 may also be a high-pressure mercury lamp.

[0047] In the exposed portion of the photosensitive film 3, an acid is generated from the photoacid generator, or a base is generated from the photobase generator. The generated acid or base decomposes the structural unit (A) contained in the polymer (P). The decomposition of the structural unit (A) is represented, for example, by the following reaction formula (4). [ka]

[0048] Next, if necessary, the exposed photosensitive film 3 is subjected to a heat treatment. For the heat treatment, a known heating device such as a hot plate or an oven can be used. The heat treatment is performed, for example, at a temperature of 60°C to 200°C for 60 to 600 seconds.

[0049] Next, the photosensitive film 3 is developed to form the water-repellent film 2. The photosensitive film 3 is developed, for example, by removing the exposed portion of the photosensitive film 3 with a developer. The developer used is, for example, one that can dissolve the decomposition product of the polymer (P) generated in the reaction formula (4) above, but hardly dissolves the polymer (P). The developer is preferably basic, particularly weakly basic. Examples of the developer include organic solvents such as propylene glycol monomethyl ether acetate (PGMEA), N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide, dimethyl sulfide, dimethyl sulfone, tetramethylurea, diglyme, triglyme, tetrahydrofuran, dioxane, cyclohexane, toluene, xylene, isoamyl acetate, dimethylammonium, and halogenated hydrocarbons; aqueous solutions of inorganic bases such as sodium hydroxide and potassium hydroxide; and aqueous solutions of organic bases such as propylamine, butylamine, monoethanolamine, tetramethylammonium hydroxide, and choline. The development process can be performed by, for example, a puddle method, a dipping method, or a shower method. The development process time is, for example, 30 to 180 seconds. After the development process, the resulting water-repellent film 2 may be washed with water. The washing time for the water-repellent film 2 is, for example, 30 to 90 seconds. After the cleaning treatment, the water-repellent film 2 may be dried. [Example]

[0050] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto.

[0051] Example 1 First, 22.6 g of perfluoro-2-methylene-4-methyl-1,3-dioxolane (compound represented by formula (M2)) was dissolved in 50 mL of 1,1,1,2,2,3,4,5,5,5-decafluoropentane (Vertrel XF, manufactured by Mitsui Chemours Fluoroproducts) under an argon atmosphere at room temperature (20°C ± 15°C). While maintaining the argon atmosphere, 0.155 g of perfluorobenzoyl peroxide was added to the resulting solution and stirred. Dissolved oxygen was then removed from the solution by freeze-degassing. The solution was heated to 40°C with stirring and reacted for 72 hours. The resulting reaction mixture was added to 300 mL of chloroform. The precipitate formed by this operation was collected by filtration. The resulting residue was a polymer of perfluoro-2-methylene-4-methyl-1,3-dioxolane (polymer (P)). The amount of the polymer obtained was 19.2 g, and the yield was 81.0%.

[0052] Next, 10 g of the resulting polymer was dissolved in 90 mL of 1,1,1,2,2,3,4,5,5,5-decafluoropentane. The resulting solution and 0.4 g of tris(4-methylphenyl)sulfonium nonafluorobutanesulfonate (WPAG-638, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a photoacid generator were added to a glass vial (200 mL) and thoroughly stirred to obtain a homogeneous solution. The resulting solution was filtered through a PTFE filter with a pore size of 0.20 μm to prepare the photosensitive composition of Example 1.

[0053] (Comparative Example 1) First, a polymer composed of structural units represented by the following formulas (5) to (7) was prepared. The content of the structural unit represented by formula (5) in the polymer was 63 mol %, the content of the structural unit represented by formula (6) was 26 mol %, and the content of the structural unit represented by formula (7) was 11 mol %. [ka]

[0054] Next, 100 parts by mass of the above polymer, 2.5 parts by mass of triphenylsulfonium nonafluorobutanesulfonate as a photoacid generator, 0.1 part by mass of surfactant R-08 (manufactured by DIC Corporation), 0.2 parts by mass of tripentylamine, 0.09 part by mass of salicylic acid, and 600 parts by mass of ethyl lactate (EL) were mixed to prepare a photosensitive composition of Comparative Example 1.

[0055] (developability) The developability of the photosensitive compositions of Example 1 and Comparative Example 1 was evaluated by the following method. First, the photosensitive composition was applied to a 4-inch quartz glass plate. The photosensitive composition was applied by spin coating at 1000 rpm for 30 seconds. Next, the photosensitive composition was heated at 100°C for 300 seconds using a hot plate to form a photosensitive film.

[0056] Next, the photosensitive film was exposed to light through a mask (a mask capable of forming a circular hole pattern with a diameter of 50 μm) using a high-pressure mercury lamp as a light source, with an exposure dose of 800 mJ / cm 2 2 In the exposed portions of the photosensitive film, acid was generated from the photoacid generator, causing the polymer to decompose. After the exposure of the photosensitive film, the photosensitive film was heated at 120°C for 120 seconds using a hot plate to promote the decomposition of the polymer.

[0057] Next, the exposed photosensitive film was developed. A 2.38 wt% aqueous solution of tetramethylammonium hydroxide (TMAH) was used as the developer. The development process was carried out by dipping for 60 seconds. This resulted in the formation of a developed film. The developed film had a thickness of 3.0 μm. After rinsing with water, the developed film was dried at 120°C for 60 seconds.

[0058] Next, the developed film was observed with a microscope (Keyence Corporation, VHX Digital Microscope). When it was confirmed that holes with a diameter of 50 μm were opened in the developed film, the developability of the photosensitive composition was judged to be good (◯). When holes with a diameter of 50 μm were not opened in the developed film or no pattern was formed in the developed film, the developability of the photosensitive composition was judged to be poor (×). The results are shown in Table 1.

[0059] (contact angle) The contact angle with water was evaluated by the above-mentioned method for the developed films prepared from the photosensitive compositions of Example 1 and Comparative Example 1. The results are shown in Table 1.

[0060] [Table 1]

[0061] As can be seen from Table 1, the photosensitive composition containing polymer (P) had good developability. Furthermore, the developed film formed from the photosensitive composition containing polymer (P) had a large contact angle with water and high water repellency. A developed film with such high water repellency is suitable for applications such as biochips and microchannel chips. [Industrial Applicability]

[0062] The developed film formed from the photosensitive composition of this embodiment is suitable for use in biochips, microchannel chips, and the like. [Explanation of symbols]

[0063] 1 board 2. Water-repellent film (development film) 3 Photosensitive film 5 Opening 10 devices 20 Mask 25 Opening 30 light source

Claims

1. A substrate; a water-repellent film disposed on the substrate; Equipped with The water-repellent film contains a polymer (P) including a structural unit represented by the following formula (1) and a photoacid generator: The polymer (P) does not contain a hydrogen atom, The water-repellent film does not contain any other polymers other than the polymer (P). Biochips or microfluidic chips. 【Chemistry 1】 [In formula (1), R ff 1 ~R ff 4 R each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms. ff 1 and R ff 2 may be linked to form a ring.

2. The biochip or microchannel chip according to claim 1 , wherein the water-repellent film has an opening.

3. 3. The biochip or microchannel chip according to claim 1, wherein the polymer (P) is perfluorinated.

4. 4. The biochip or microchannel chip according to claim 1, wherein the polymer (P) contains the structural unit in the largest amount on a molar basis.

5. The biochip or microchannel chip according to any one of claims 1 to 4, wherein the structural unit is represented by the following formula (2): 【Chemistry 2】

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