Photoresist films and their applications

Abstract

This invention provides a photoresist film and its application. The photoresist film has a thickness T in micrometers, and when measured by ultraviolet-visible spectroscopy, it exhibits an absorbance A for light with a wavelength of 405 nanometers. 405nm It has an absorbance of A for light with a wavelength of 436 nanometers. 436nm , of which 0 405nm / T≦0.006and0 436nm / T≦0.005, and the thickness T is 60 micrometers to 600 micrometers.​​

Description

Technical Field

[0001] This invention relates to a photoresist film, and more particularly to a high-thickness photoresist film, and the application of the photoresist film. Background Technology

[0002] Based on their changes after exposure and development, photoresist films are classified into positive photoresist films and negative photoresist films. With positive photoresist films, the areas exposed to light dissolve during development, leaving the pattern of the unexposed areas. With negative photoresist films, the areas not exposed to light dissolve during development, leaving the pattern of the exposed areas.

[0003] In the printed circuit board (PCB) industry, photoresist films are essential for etching or electroplating processes to form circuit patterns. As electronic components become increasingly complex and larger, the demand for thick photoresist films with high aspect ratios is growing. However, existing photoresist films still cannot stably form high-precision photoresist patterns after exposure and development, often resulting in poor photoresist profiles and even noticeable footing, affecting the accuracy of subsequent etching or electroplating processes. Therefore, improvements are urgently needed. Summary of the Invention

[0004] In view of the above-mentioned technical problems, the present invention aims to provide a photoresist film with a good photoresist cross-sectional profile after exposure, which can achieve high-precision etching or electroplating processing.

[0005] Therefore, one object of the present invention is to provide a photoresist film having a thickness T in micrometers, and the photoresist film having an absorbance A for light with a wavelength of 405 nanometers when measured by ultraviolet-visible spectroscopy. 405nm It has an absorbance of A for light with a wavelength of 436 nanometers. 436nm , where 0 < A 405nm / T≤0.006 and 0<A 436nm / T≤0.005, and the thickness T is 60 micrometers to 600 micrometers.

[0006] In some embodiments of the present invention, the photoresist film, when measured by ultraviolet-visible spectroscopy, exhibits absorbance A for light with a wavelength of 365 nanometers. 365nm , where 0 < A 365nm / T≤0.010.

[0007] In some embodiments of the present invention, the ultraviolet-visible spectroscopy is performed using an ultraviolet-visible spectrophotometer under the following conditions: the photoresist film is placed perpendicular to the direction of the incident light source; a diffraction grating is configured as a spectrometer; the test temperature is 25°C; the test pressure is 1 atm; the analysis mode is absorbance; the scanning wavelength range is 190 nm to 1100 nm; the blank sample is air; the scanning speed is 2200 nm / min; the lamp source switching wavelength from deuterium lamp to tungsten filament lamp is 340.8 nm; the sampling interval is 0.2 nm; and the slit width is 2.0 nm.

[0008] In some embodiments of the present invention, the photoresist film is a negative photoresist film.

[0009] In some embodiments of the present invention, 0 < A 405nm / T≤0.002 and 0<A 436nm / T≤0.001.

[0010] In some embodiments of the present invention, the photoresist film comprises: (A) an alkali-soluble polymer; (B) an ethylene-containing unsaturated double bond compound; and (C) a photopolymerization initiator.

[0011] In some embodiments of the present invention, the ethylene-containing unsaturated double bond compound (B) comprises a bifunctional acrylic compound.

[0012] In some embodiments of the present invention, the content of the difunctional acrylic compound is 60% by weight or more, based on the total weight of the ethylene-containing unsaturated double bond compound (B).

[0013] Another object of the present invention is to provide a composite film comprising: a photoresist film as described above, and a protective film formed on at least one surface of the photoresist film.

[0014] In some embodiments of the present invention, the protective film is selected from the group consisting of polyethylene terephthalate films, polyolefin films, and the aforementioned composites.

[0015] To make the above-mentioned objectives, technical features and advantages of the present invention more apparent and understandable, the following detailed description is provided with reference to some specific embodiments. Detailed Implementation

[0016] The following describes some specific embodiments of the present invention; however, the present invention can be practiced in many different forms and should not be construed as limited to those set forth in the specification.

[0017] Unless otherwise stated, the terms “a,” “the,” and similar terms used in this specification and claims shall be understood to include both singular and plural forms.

[0018] Unless otherwise stated, the terms “first,” “second,” and similar terms used in this specification and claims are used only to distinguish the described elements or components and have no special meaning in themselves, nor are they used to indicate a sequence.

[0019] Unless otherwise stated, the terms “(meth)acrylic acid,” “(meth)acrylate,” and similar terms as used in this specification are intended to cover cases that include or exclude the groups enclosed in parentheses. For example, “(meth)acrylic polymers having a carboxyl group” is intended to cover both acrylic polymers having a carboxyl group and methacrylic polymers having a carboxyl group, and “(meth)acrylate” is intended to cover both methyl acrylate and methyl methacrylate.

[0020] In this specification and claims, the weight average molecular weight (Mw) is determined by gel permeation chromatography (GPC) and compared and converted with standards, and its unit is "grams per mol (g / mol)".

[0021] The advantages of this invention compared to the prior art are particularly evident in that, by controlling A 405nm / T and A 436nm When the value of / T is within a specific range, a photoresist film with a good cross-sectional profile after exposure can be provided, thereby enabling high-precision etching or electroplating processes. The following provides a detailed description of the photoresist film of this invention and its applications.

[0022] 1. Photoresist film

[0023] The photoresist film described in this article refers to a film containing a photosensitive resin composition.

[0024] The surface of the photoresist film may be additionally covered with a protective film to provide protection and support, facilitating storage and preventing foreign matter adhesion or damage. In this document, unless otherwise stated, properties such as "thickness" and "absorbance" refer to the photoresist film itself and do not include other components such as protective films used in conjunction with it. Further explanation regarding the photoresist film follows.

[0025] 1.1. Properties of photoresist films

[0026] The photoresist film of this invention possesses specific light absorption properties. Specifically, when measured by ultraviolet-visible spectroscopy, the photoresist film exhibits an absorbance A for light with a wavelength of 405 nanometers. 405nm It has an absorbance of A for light with a wavelength of 436 nanometers. 436nm Absorbance A 405nm The relationship between the photoresist film thickness T (unit: micrometers) and the photoresist film thickness T satisfies 0 < A405nm / T≤0.006, and absorbance A 436nm The relationship with thickness T satisfies 0 < A 436nm / T≤0.005. For example, A 405nm / T can be 0.0005, 0.001, 0.0015, 0.002, 0.0025, 0.003, 0.0035, 0.004, 0.0045, 0.005, 0.0055, or 0.006, or a range consisting of any two of the above values. A 436nm / T can be 0.0005, 0.001, 0.0015, 0.002, 0.0025, 0.003, 0.0035, 0.004, 0.0045, or 0.005, or a range consisting of any two of the above values. If A 405nm / T or A 436nm If the value of T exceeds the above range, the cross-sectional profile of the photoresist pattern formed after exposure and development will be poor, making it unsuitable for etching or electroplating processes requiring high precision. In a preferred embodiment of the present invention, 0 < A 405nm / T≤0.002 and 0<A 436nm / T≤0.001.

[0027] In some embodiments of the present invention, when measured by ultraviolet-visible spectroscopy, the photoresist film exhibits absorbance A for light with a wavelength of 365 nanometers. 365nm , where 0 < A 365nm / T≤0.010, where T is in micrometers. For example, A 365nm / T can be 0.0005, 0.001, 0.0015, 0.002, 0.0025, 0.003, 0.0035, 0.004, 0.0045, 0.005, 0.0055, 0.006, 0.0065, 0.007, 0.0075, 0.008, 0.0085, 0.009, 0.0095, or 0.010, or a range consisting of any two of the above values.

[0028] In this invention, ultraviolet-visible spectroscopy is performed using an ultraviolet-visible spectrophotometer under the following conditions: the photoresist film is placed perpendicular to the incident light source; a diffraction grating is used as a spectrometer; the test temperature is 25°C; the test pressure is 1 atm; the analysis mode is absorbance; the scanning wavelength range is 190 nm to 1100 nm; the blank sample is air; the scanning speed is 2200 nm / min; the lamp source switching wavelength from deuterium lamp to tungsten lamp is 340.8 nm; the sampling interval is 0.2 nm; and the slit width is 2.0 nm. Under the aforementioned test conditions, the photoresist film sample used for analysis is obtained by cutting a composite film containing the photoresist film and protective films located on both sides of the photoresist film into a size of 5 cm × 3 cm at any position along the transverse direction (TD) and the machine direction (MD), and then removing the protective films on both sides of the cut photoresist film. The photoresist film must be placed perpendicular to the direction of the incident light source to accurately measure its absorbance. The tungsten filament lamp used as the incident light source has a wavelength range greater than 340.8 nm. Additionally, the "sampling interval" refers to taking a data point every 0.2 nm within the scanning wavelength range of 190 nm to 1100 nm and recording its value.

[0029] A of the photoresist film of the present invention 405nm A 436nm A 365nm The absorbance value can be adjusted by modifying the composition of the photoresist film or the drying conditions of the photoresist film process. For example, the composition of the photoresist film can be adjusted by selecting the type and content of additives, including but not limited to photopolymerization initiators, light absorbers, and dyes. Those skilled in the art, after reading the teachings of this specification, can achieve the desired absorbance through conventional experiments.

[0030] The thickness T of the photoresist film of the present invention is expressed in micrometers, and its range is from 60 micrometers to 600 micrometers, preferably from 100 micrometers to 600 micrometers, for example 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, 100 micrometers, 110 micrometers, 120 micrometers, 130 micrometers, 140 micrometers, 150 micrometers, 160 micrometers, 170 micrometers, 180 micrometers, 190 micrometers, 200 micrometers, 210 micrometers, 220 micrometers, 230 micrometers, 240 micrometers, 250 micrometers, 260 micrometers, 270 micrometers, 280 micrometers, 290 micrometers, and 300 micrometers. The photoresist thickness can be 310 μm, 320 μm, 330 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm, 410 μm, 420 μm, 430 μm, 440 μm, 450 μm, 460 μm, 470 μm, 480 μm, 490 μm, 500 μm, 510 μm, 520 μm, 530 μm, 540 μm, 550 μm, 560 μm, 570 μm, 580 μm, 590 μm, or 600 μm, or a range between any two of the above values. Since a higher photoresist thickness allows for a higher plating thickness of the metal conductive layer, the photoresist film of this invention is particularly suitable for use in 2.5D and 3D integrated circuit packaging, and can be used as a patterning application before electroplating of the conductive layer.

[0031] The photoresist film of the present invention can be a positive photoresist film or a negative photoresist film. In some embodiments of the present invention, the photoresist film is a negative photoresist film, that is, after exposure, the unexposed parts of the photoresist film will dissolve during development, leaving the pattern of the exposed parts after development.

[0032] In one embodiment of the present invention, the photoresist film is a dry film, i.e., a resin film with low solvent content. The low solvent content means that the solvent content is less than 10% by weight of the total weight of the photoresist film, specifically less than 5% by weight, and more specifically 0.1 to 4% by weight. Compared to ink-like or liquid wet films, dry films, due to their low solvent content, are less prone to flow or deformation, and can be adhered to the substrate without additional coating or drying processes, thus being easier to control and having better operability.

[0033] 1.2. Composition of photoresist film

[0034] In the case that 0 < A 405nm / T≤0.002 and 0<A 436nm Under the condition that / T≤0.001, the composition of the photoresist film of the present invention can be adjusted as needed. In some embodiments of the present invention, the photoresist film is a negative photoresist film, which comprises (A) an alkali-soluble polymer, (B) a compound containing ethylene unsaturated double bonds, and (C) a photopolymerization initiator, and may further comprise additives as needed.

[0035] 1.2.1.(A) Alkali-soluble polymers

[0036] Alkali-soluble polymers are polymers containing carboxyl groups, examples of which include, but are not limited to, acrylic polymers containing carboxyl groups, vinyl aromatic polymers containing carboxyl groups, norbornene polymers containing carboxyl groups, epoxy polymers containing carboxyl groups, amide polymers containing carboxyl groups, amide-epoxy polymers containing carboxyl groups, alkyd polymers containing carboxyl groups, and phenolic polymers containing carboxyl groups. The aforementioned alkali-soluble polymers can be used alone or in combination. In some embodiments of the present invention, the alkali-soluble polymer is an acrylic polymer containing carboxyl groups.

[0037] Alkali-soluble polymers can be obtained by polymerizing one or more polymerizable monomers having carboxyl groups, or by copolymerizing one or more polymerizable monomers having carboxyl groups with other polymerizable monomers without carboxyl groups, and may therefore contain repeating units derived from polymerizable monomers having carboxyl groups, or contain repeating units derived from polymerizable monomers having carboxyl groups and repeating units of other polymerizable monomers.

[0038] In some embodiments of the present invention, the alkali-soluble polymer has repeating units derived from at least one first polymerizable monomer and repeating units derived from at least one second polymerizable monomer, wherein the first polymerizable monomer has a carboxyl group, and examples of such first polymerizable monomers include, but are not limited to, (meth)acrylic acid, α-bromo(meth)acrylic acid, α-chloro(meth)acrylic acid, β-o-benzoimide(meth)acrylic acid, β-styryl(meth)acrylic acid, propiolic acid, fumaric acid, cinnamic acid, crotonic acid, itconic acid, and maleic acid. The second polymerizable monomer does not have a carboxyl group, and examples of such monomers include, but are not limited to, (meth)acrylate compounds, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl(meth)acrylate, tributyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 1-methyl-cyclopentyl (meth)acrylate, 1-methyl-cyclohexyl (meth)acrylate, 2-(meth)acrylate-2-methyl-adamantyl (meth)acrylate, 2-(meth)acrylate-2-ethyl -Adamantyl ester, 2-(meth)acrylate-2-butyl-adamantyl ester, tetrahydrofuran methyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, glycidyl methacrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate; (meth)acrylonitrile; vinyl ester compounds, such as vinyl acetate, vinyl n-butyl ester; vinyl aromatic compounds, such as styrene, vinylnaphthalene, 3-acetoxystyrene, 4-acetoxystyrene, vinyltoluene, α-methylstyrene; norbornene; acrylamide; maleate compounds, such as monomethyl maleate, monoethyl maleate, monoisopropyl maleate; and derivatives of the aforementioned polymerizable monomers. The first monomer and the second monomer may be used independently or in combination.

[0039] In a preferred embodiment of the invention, the alkali-soluble polymer is obtained by copolymerizing (meth)acrylic acid with one or more (meth)acrylate compounds, and thus comprises repeating units derived from (meth)acrylic acid and repeating units derived from (meth)acrylate compounds. The weight ratio of (meth)acrylic acid to (meth)acrylate compounds can be from 1:20 to 1:1, more specifically from 1:6 to 1:4. For example, the weight ratio of (meth)acrylic acid to (meth)acrylate compounds can be 1:20, 1:19, 1:18, 1:17, 1:16, 1:15, 1:14, 1:13, 1:12, 1:11, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, or 1:1, or falls within a range consisting of any two of the above values.

[0040] The alkali-soluble polymer has a molecular weight ranging from 10,000 to 180,000, preferably from 40,000 to 80,000, for example 10,000, 15,000, 20,000, 25,000, 30,000, 35,000, 40,000, 45,000, 50,000, 55,000, 60,000, 65,000, 70,000, 75,000, 80,000, 85,000, 90,000, etc. 00, 95,000, 100,000, 105,000, 110,000, 115,000, 120,000, 125,000, 130,000, 135,000, 140,000, 145,000, 150,000, 155,000, 160,000, 165,000, 170,000, 175,000, or 180,000, or a range consisting of any two of the above values.

[0041] In the photoresist film of the present invention, the content of the alkali-soluble polymer, based on the total weight of the photoresist film, can be from 20% to 85% by weight, more specifically from 40% to 80% by weight, and even more specifically from 50% to 75% by weight. For example, the content of the alkali-soluble polymer, based on the total weight of the photoresist film, can be 20 wt%, 22.5 wt%, 25 wt%, 27.5 wt%, 30 wt%, 32.5 wt%, 35 wt%, 37.5 wt%, 40 wt%, 42.5 wt%, 45 wt%, 47.5 wt%, 50 wt%, 52.5 wt%, 55 wt%, 57.5 wt%, 60 wt%, 62.5 wt%, 65 wt%, 67.5 wt%, 70 wt%, 72.5 wt%, 75 wt%, 77.5 wt%, 80 wt%, 82.5 wt%, or 85 wt%, or a range consisting of any two of the above values.

[0042] 1.2.2.(B) Compounds containing ethylene-containing unsaturated double bonds

[0043] Compounds containing ethylene unsaturated double bonds refer to compounds having at least one reactive ethylene functional group, preferably difunctional compounds having two reactive ethylene functional groups. In some embodiments of the present invention, the ethylene-containing unsaturated double bond compound is a monofunctional or polyfunctional acrylic compound, preferably a difunctional acrylic compound, examples of which include, but are not limited to, ethoxylated trimethylolpropane triacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, polypropylene glycol diacrylate, tri((meth)acryloyloxyisocyanate)hexamethylene isocyanate, ethoxylated urate di(meth)acrylate, propoxylated urate di(meth)acrylate, ethoxylated / propoxylated urate di(meth)acrylate, ethoxylated tri(methacryloyloxyisocyanate)hexamethylene isocyanate, acrylated tri(methacryloyloxyisocyanate)hexamethylene isocyanate, and ethoxylated / propoxylated tri(methacryloyloxyisocyanate)hexamethylene isocyanate. Furthermore, based on the total weight of the ethylene-containing unsaturated double bond compound, the content of the difunctional acrylic compound is preferably 60% by weight or more, for example 60% by weight, 62.5% by weight, 65% by weight, 67.5% by weight, 70% by weight, 72.5% by weight, 75% by weight, 77.5% by weight, 80% by weight, 82.5% by weight, 85% by weight, 87.5% by weight, 90% by weight, 92.5% by weight, 95% by weight, 97.5% by weight, or 100% by weight, or within a range consisting of any two of the above values.

[0044] In some embodiments of the present invention, the ethylene-containing unsaturated double bond compound comprises ethoxylated trimethylolpropane triacrylate and ethoxylated bisphenol A dimethacrylate.

[0045] In the photoresist film of the present invention, the content of the vinyl unsaturated double bond compound can be from 5% to 70% by weight, more specifically from 15% to 50% by weight, and even more specifically from 20% to 45% by weight, based on the total weight of the photoresist film. For example, the content of ethylene-containing unsaturated double bond compounds, based on the total weight of the photoresist film, can be 5 wt%, 7.5 wt%, 10 wt%, 12.5 wt%, 15 wt%, 17.5 wt%, 20 wt%, 22.5 wt%, 25 wt%, 27.5 wt%, 30 wt%, 32.5 wt%, 35 wt%, 37.5 wt%, 40 wt%, 42.5 wt%, 45 wt%, 47.5 wt%, 50 wt%, 52.5 wt%, 55 wt%, 57.5 wt%, 60 wt%, 62.5 wt%, 65 wt%, 67.5 wt%, or 70 wt%, or a range consisting of any two of the above values.

[0046] 1.2.3.(C) Photopolymerization initiator

[0047] Photopolymerization initiators are substances that can initiate polymerization reactions in response to light. There are no particular limitations on the types of photopolymerization initiators, and examples include, but are not limited to, imidazole compounds, ketone compounds, quinone compounds, benzoin or benzoin ether compounds, polyhalogenated compounds, triazine compounds, organic peroxides, onium salts, and other photopolymerization initiators commonly found in the art. The aforementioned photopolymerization initiators can be used individually or in combination.

[0048] Examples of the aforementioned imidazole compounds include, but are not limited to, 2,4,6-triarylimidazolium dimers, such as 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazolium dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazolium dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazolium dimer.

[0049] Examples of the aforementioned ketone compounds include, but are not limited to, benzophenone, 4,4-bis(dimethylamino)benzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 4,4′-dimethoxybenzophenone, 4-dimethylaminobenzophenone, 4-dimethylaminoacetophenone, xanthonone, thioxanthonone, 2-chlorothioxanthonone, 2,4-diethylthioxanthonone, acridinone, α-hydroxyacetophenone, α-aminoacetophenone, α-hydroxycycloalkylphenyl ketone, and diekoxyacetophenone.

[0050] Examples of the aforementioned quinone compounds include, but are not limited to, camphorquinone, benzylanthraquinone, 2-tertiary butylanthraquinone, and 2-methylanthraquinone.

[0051] Examples of the aforementioned benzoin or benzoin ether compounds include, but are not limited to, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin phenyl ether.

[0052] Examples of the aforementioned polyhalogenated compounds include, but are not limited to, carbon tetrabromide, phenyltribromomethyl sulfone, and phenyltrichloromethyl ketone.

[0053] Examples of the aforementioned triazine compounds include, but are not limited to, 2,4,6-trichloromethyl)-s-triazine, 2-methoxy-4,6-bis(trichloromethyl)-s-triazine, 2-amino-4,6-bis(trichloromethyl)-s-triazine, and 2-(p-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine.

[0054] Examples of the aforementioned organic peroxides include, but are not limited to, methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, benzoyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(benzylperoxy)hexane, tert-butyl peroxide, α,a′-bis(tert-butylperoxyisopropyl)benzene, dicumyl peroxide, and 3,3′,4,4′-tetra-(tert-butylperoxycarbonyl)benzophenone.

[0055] Examples of the aforementioned onium salt compounds include, but are not limited to, diaryliodoium salts and triarylsulfonium salts obtained by combining biphenyliodonium, 4,4′-dichlorobiphenyliodonium, 4,4′-dimethoxybiphenyliodonium, 4,4′-di-tri-butylbiphenyliodonium, 4-methyl-4′-isopropyl-biphenyliodonium, or 3,3′-dinitrobiphenyliodonium with chlorides, bromides, tetrafluoroborates, hexafluorophosphates, hexafluoroarsenates, hexafluoroantimonates, and tetra(pentafluorophenyl)borates or trifluoromethanesulfonic acids.

[0056] Examples of other photopolymerization initiators commonly found in the art include, but are not limited to, fumonisins, bisacylphosphine oxide compounds, azinium compounds, organoboron compounds, phenylacetalates, and dicerocene.

[0057] In some embodiments of the present invention, the photopolymerization initiator is an imidazole compound or a ketone compound.

[0058] In the photoresist film of the present invention, the content of the photopolymerization initiator, based on the total weight of the photoresist film, can be from 0.1% to 15% by weight, more specifically from 0.5% to 10% by weight, and even more specifically from 1% to 5% by weight. For example, relative to the total weight of the photoresist film, the content of the photopolymerization initiator can be 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, 10 wt%, 10.5 wt%, 11 wt%, 11.5 wt%, 12 wt%, 12.5 wt%, 13 wt%, 13.5 wt%, 14 wt%, 14.5 wt%, or 15 wt%, or within a range consisting of any two of the above values.

[0059] 1.2.4. Additives as needed

[0060] In the case that 0 < A 405nm / T≤0.002 and 0<A 436nm Under the condition that / T≤0.001, the photoresist film of the present invention may further contain additives to specifically improve the properties of the photoresist film. Examples of such additives include, but are not limited to, light absorbers, dyes, pigments, free radical inhibitors, and surfactants. These additives may be used alone or in any combination. In some embodiments of the present invention, the photoresist film further contains a light absorber to adjust the absorbance of the photoresist film for a specific wavelength of light to a desired range.

[0061] 1.3. Preparation of photoresist film

[0062] The preparation method of the photoresist film of this invention is not particularly limited. Those skilled in the art can prepare the photoresist film based on the disclosure in this specification. Taking the preparation of the negative photoresist film described above as an example, the components of the photoresist film, including (A) an alkali-soluble polymer, (B) an ethylene-containing unsaturated double-bond compound, (C) a photopolymerization initiator, and other additives as needed, can be uniformly mixed and dissolved or dispersed in a solvent using a stirrer to form a resin composition. The resulting resin composition is then coated onto a substrate and dried to obtain the photoresist film. Detailed preparation methods are illustrated in the examples below and will not be repeated here.

[0063] 2. Applications of photoresist films

[0064] Before use, photoresist films are typically coated with a protective film on both surfaces to provide protection and support, facilitating storage and preventing foreign matter adhesion or damage. Therefore, this invention provides a composite film comprising the photoresist film of this invention as described above, and a protective film formed on at least one surface of the photoresist film. In a preferred embodiment of this invention, the protective film is formed on both surfaces of the photoresist film, and the materials of the protective films formed on the two surfaces of the photoresist film may be the same or different.

[0065] There are no particular limitations on the type of protective film, and various materials well known in the technical field to which this invention pertains can be used. For example, the protective film that can be used in this invention may be selected from the following group: polyethylene terephthalate film (PET film), polyolefin film, and the aforementioned composites. Examples of the polyolefin film include, but are not limited to, polyethylene film (PE film) and polypropylene film (PP film), such as oriented polypropylene film, and the composite may be a composite of polyethylene terephthalate film and polyolefin film, or a composite of different polyolefin films. In a preferred embodiment of the invention, the composite film comprises a PET film formed on one surface of the photoresist film and a PE film formed on the other surface of the photoresist film.

[0066] The preparation method of the composite film of the present invention is not particularly limited, and methods well known in the art can be used. Those skilled in the art can prepare the composite film based on the disclosure in this specification. For example, a protective film can be laminated onto two surfaces of a photoresist film to provide a laminate, and pressure can be applied to the laminate to obtain a composite film. Alternatively, a resin composition for forming the photoresist film can be first coated onto a first protective film and dried to form a photoresist film on the first protective film, and then a second protective film can be attached to the surface of the photoresist film that is not in contact with the first protective film, thereby obtaining a composite film. Alternatively, a resin composition for forming the photoresist film can be extruded between two protective films having a fixed spacing, and then dried to form a photoresist film between the two protective films.

[0067] 3. Example

[0068] 3.1 Measurement Method

[0069] [Photoresist film thickness]

[0070] After cutting the composite film containing the photoresist film into 5 cm × 3 cm pieces, the protective films on both sides of the photoresist film were removed. The photoresist film was placed on the base (MS-11C base) of a film thickness gauge (model: Nikon Digimicro MFC-101+MS-11C, purchased from Nikon Corporation). The MFC-101 measuring instrument was used to measure the thickness at 140 g / L, and the average value was taken.

[0071] [Absorbance of the photoresist film]

[0072] After cutting the composite film containing the photoresist film into 5 cm × 3 cm pieces, the protective films on both sides of the photoresist film were removed. The photoresist film was measured using a UV-Vis spectrophotometer (model: Shimadzu UV-1601, purchased from Shimadzu Corporation) as follows. The photoresist film was placed perpendicular to the incident light source using a fixture under the following conditions: a diffraction grating was used as a spectrometer; the test temperature was 25°C; the test pressure was 1 atm; the analysis mode was absorbance; the scanning wavelength range was 190 nm to 1100 nm; the blank sample was air; the scanning speed was 2200 nm / min; the lamp source switching wavelength from deuterium lamp to tungsten lamp was 340.8 nm; the sampling interval was 0.2 nm; the slit width was 2.0 nm; and the absorbance A for light at a wavelength of 405 nm was obtained using Shimadzu UV Probe V1.11 software. 405nm Absorbance A for light with a wavelength of 436 nanometers 436nm and absorbance A for light with a wavelength of 365 nanometers. 365nm .

[0073] [Cross-sectional shape of the photoresist pattern]

[0074] A 6-inch diameter Ti(600A) / Cu(2000A) wafer with a thickness of 625 micrometers was preheated in a batch oven at 80°C for 10 minutes, maintaining the surface temperature at 50°C before lamination. The photoresist film was placed on the wafer and pressed using a laminator (model: CSL-M25E, purchased from Zhisheng Industrial). The laminator temperature was 105°C, the pressure was 3 kg / cm², and the lamination speed was 2.0 m / min. After lamination, excess film was removed, and the sample was allowed to stand for 15 minutes to cool to room temperature.

[0075] The development point test was performed under the following conditions: a 0.9% to 1.1% Na2CO3 aqueous solution was used, the liquid temperature was set to 29°C to 31°C, and the spray pressure was set to 2.0 kg / cm²; the photoresist film sample along with the wafer was placed in a developer (model: S30C, purchased from Zaoli Company), and the rinsing and shaking were turned on, with the development section and the water rinsing section both being 1.3 meters long; and the time when the photoresist was just completely developed and removed was recorded as the minimum developing time (MDT).

[0076] The photoresist film was exposed using an exposure machine (Ultratech Stepper Spectrum, purchased from Ultratech). Exposure wavelengths were 405 nm, 436 nm, and 365 nm, with continuous exposure until the exposure energy reached 800 mJ / cm². The predetermined aspect ratio of the resulting photoresist pattern was 2.0, and the ratio of the patterned portion to the non-patterned portion (i.e., the diameter of the via: the width of the photoresist) was 1:1. After exposure, the exposed photoresist film was allowed to stand for 30 minutes. Then, the exposed photoresist film was developed using a 0.9% to 1.1% Na₂CO₃ aqueous solution, with the liquid temperature set at 29°C to 31°C, the spray pressure set at 2.0 kg / cm², and the development time twice the development time (MDT*2) to obtain the developed photoresist film.

[0077] Using a wafer dicing tool, the developed photoresist film, along with the wafer, was diced at the non-patterned portion (i.e., via) of the photoresist. The cross-sectional shape of the photoresist pattern was observed using a scanning electron microscope, with the sample tilted at 75° and a magnification of 200x. A random photoresist cross-section was selected, and the width of the photoresist was measured at 1 / 25, 2 / 25, 3 / 25, 4 / 25, and 5 / 25 of the total thickness, starting from the upper edge (the side away from the wafer). The average of these five width values ​​was taken as the upper width. Similarly, the width of the photoresist was measured at 1 / 25, 2 / 25, 3 / 25, 4 / 25, and 5 / 25 of the total thickness, starting from the lower edge (the side in contact with the wafer). The average of these five width values ​​was taken as the lower width. If the value of "|(top width - bottom width)| / thickness" is less than 0.04, it is recorded as "rectangular", indicating that the cross-sectional shape of the photoresist pattern is good; if the value of "|(top width - bottom width)| / thickness" is greater than or equal to 0.04, it is recorded as "trapezoidal", indicating that the cross-sectional shape of the photoresist pattern is poor. "|(top width - bottom width)|" in the formula represents the absolute value.

[0078] [Length of the base of the photoresist pattern]

[0079] A 6-inch diameter Ti(600A) / Cu(2000A) wafer with a thickness of 625 micrometers was preheated in a batch oven at 80°C for 10 minutes, maintaining the surface temperature at 50°C before lamination. The photoresist film was placed on the wafer and pressed using a laminator (model: CSL-M25E, purchased from Zhisheng Industrial). The laminator temperature was 105°C, the pressure was 3 kg / cm², and the lamination speed was 2.0 m / min. After lamination, excess film was removed, and the sample was allowed to stand for 15 minutes to cool to room temperature.

[0080] Exposure was performed using an Ultratech Stepper Spectrum exposure machine (purchased from Ultratech). Exposure light wavelengths were 405 nm, 436 nm, and 365 nm, with continuous exposure until the exposure energy reached 800 mJ / cm². The predetermined aspect ratio of the resulting photoresist pattern was 2.0, and the ratio of the patterned portion to the non-patterned portion (i.e., the diameter of the via: the width of the photoresist) was 1:1. After exposure, the exposed photoresist film was allowed to stand for 30 minutes to 24 hours. Then, the exposed photoresist film was developed using a 0.9% to 1.1% Na₂CO₃ aqueous solution, with the liquid temperature set to 29°C to 31°C, the spray pressure set to 2.0 kg / cm², and the development times being twice the development time (MDT*2) and four times the development time (MDT*4), respectively, to obtain the developed photoresist film. The development point (MDT) was based on the development point test results of the [cross-sectional shape of the photoresist pattern].

[0081] Using a wafer dicing tool, the developed photoresist film, along with the wafer, is diced at the non-patterned portion (i.e., via) of the photoresist. The cross-sectional shape of the photoresist pattern is observed using a scanning electron microscope, with the sample tilted at 75° and magnification at 5000x. A photoresist cross-section is randomly selected, and the side with the largest protrusion from the bottom towards the non-patterned portion is chosen for calculating the foot length. The calculation method is as follows: the photoresist sidewall position, where the thickness is 1 / 5 of the total photoresist thickness, is taken as the reference point. A reference line perpendicular to the wafer surface is extended downward from the reference point. The length from the intersection of the reference line and the wafer surface to the intersection of the photoresist sidewall and the wafer surface is the foot length.

[0082] 3.2. Preparation and Testing of Photoresist Films

[0083] 3.2.1. Synthesis of Alkali-Soluble Polymers

[0084] Acrylic polymers with carboxyl groups were prepared as alkali-soluble polymers according to the following synthesis examples 1 to 3.

[0085] [Synthesis example 1]

[0086] Solution a1 was prepared by mixing 15 g of methacrylic acid, 50 g of methyl methacrylate, 30 g of butyl acrylate, and 5 g of butyl methacrylate as copolymer monomers with 1.0 g of azobisisoheptanenitrile. Solution b1 was prepared by dissolving 0.5 g of azobisisoheptanenitrile in 20 g of ethyl acetate.

[0087] Prepare a flask equipped with a stirrer, reflux cooler, thermometer, and dropper. Add 80 g of ethyl acetate solvent to the flask and heat to 70°C. Then, add solution a1 dropwise to the flask at a fixed rate over a total of 3 hours. Maintain the temperature of the solution in the flask at 70°C and stir for 2 hours. Next, add solution b1 dropwise to the flask at a fixed rate over a total of 0.5 hours. Maintain the temperature of the solution in the flask at 70°C and stir for 5 hours. Afterward, heat the solution in the flask to 90°C and stir for 5 hours to ensure the reaction proceeds fully. After the reaction is complete, cool the product to room temperature to obtain an acrylic polymer A with carboxyl groups (hereinafter referred to as "polymer A"), with a weight average molecular weight of 65,000 and a solid content of 50% by weight.

[0088] [Synthesis example 2]

[0089] Solution a2 was prepared by mixing 15 g of methacrylic acid, 65 g of methyl methacrylate, 10 g of butyl acrylate, and 10 g of butyl methacrylate as copolymer monomers with 0.75 g of azobisisoheptanenitrile. Solution b2 was prepared by dissolving 0.5 g of azobisisoheptanenitrile in 20 g of ethyl acetate.

[0090] Prepare a flask equipped with a stirrer, reflux cooler, thermometer, and dropper. Add 102.2 g of ethyl acetate solvent to the flask and heat to 70°C. Then, add solution a2 dropwise to the flask at a fixed rate over a total of 3 hours. Maintain the temperature of the solution in the flask at 70°C and stir for 2 hours. Next, add solution b2 dropwise to the flask at a fixed rate over a total of 0.5 hours. Maintain the temperature of the solution in the flask at 70°C and stir for 5 hours. Afterward, heat the solution in the flask to 90°C and stir for 5 hours to ensure the reaction proceeds fully. After the reaction is complete, cool the product to room temperature to obtain an acrylic polymer B with carboxyl groups (hereinafter referred to as "polymer B"), with a weight average molecular weight of 65,000 and a solid content of 45% by weight.

[0091] [Synthesis example 3]

[0092] Solution a3 was prepared by mixing 20 g of methacrylic acid, 45 g of methyl methacrylate, and 35 g of 2-ethylhexyl acrylate (2-Ethylhexyl Acrylate) as copolymer monomers with 0.5 g of azobisisobutyronitrile. Solution b3 was prepared by dissolving 0.5 g of azobisisobutyronitrile in 20 g of ethyl acetate.

[0093] Prepare a flask equipped with a stirrer, reflux cooler, thermometer, and dropper. Add 80 g of ethyl acetate solvent to the flask and heat to 70°C. Then, add solution a3 dropwise to the flask at a fixed rate over a total of 3 hours. Maintain the solution temperature at 70°C and stir for 2 hours. Next, add solution b3 dropwise to the flask at a fixed rate over a total of 0.5 hours. Maintain the solution temperature at 70°C and stir for 5 hours. Finally, heat the solution temperature to 90°C and stir for 5 hours to ensure the reaction proceeds fully. After the reaction is complete, cool the product to room temperature to obtain an acrylic polymer C (hereinafter referred to as "polymer C") with carboxyl groups, a weight average molecular weight of 55,000, and a solid content of 50% by weight.

[0094] 3.2.2. Preparation of photoresist film

[0095] The raw material information used in the following embodiments and comparative examples is shown in Table 1 below.

[0096] Table 1

[0097]

[0098]

[0099] The components were mixed according to the proportions shown in Table 2 below and stirred for 1 hour to obtain a uniform resin composition. The obtained resin composition was then coated onto a PET film as a protective film using a Kodaira bar, and dried in an oven at 100°C for 24 minutes. Finally, a PE film as a protective film was applied to the surface of the dried resin composition to obtain the photoresist films (i.e., composite films) coated with a protective film as described in Examples 1 to 7 and Comparative Examples 1 to 5.

[0100]

[0101]

[0102] As shown in Table 3, the light absorption properties of the photoresist films in Examples 1 to 7 of the present invention satisfy 0 < A. 405nm / T≤0.006 and 0<A 436nm / T≤0.005, therefore the photoresist pattern formed after exposure and development can have a rectangular cross-section and a short base length (less than 10 micrometers), indicating that the photoresist pattern has an excellent cross-sectional profile. In particular, Examples 3 and 7 further show that if the light absorption properties of the photoresist film satisfy 0<A 405nm / T≤0.002 and 0<A 436nm When / T≤0.001, the length of the base of the photoresist pattern is most significantly improved, resulting in the best cross-sectional profile. In contrast, the light absorption properties of the photoresist films in Comparative Examples 1 to 5 do not satisfy 0<A 405nm / T≤0.006 and 0<A 436nm / T≤0.005, therefore the photoresist pattern formed after exposure and development does not have a rectangular cross section and the base length is long, which means that the cross-sectional profile of the photoresist pattern is not good and it is not suitable for etching or electroplating processes that require high precision.

[0103] The above embodiments are merely illustrative of the principles and effects of the present invention and to illustrate its technical features, and are not intended to limit the scope of protection of the present invention. Any changes or arrangements that can be easily made by those skilled in the art without departing from the technical principles of the present invention are within the scope of the claims of the present invention.

Claims

1. A photoresist film for use in an exposure light source containing light with wavelengths of 405 nm, 436 nm, and 365 nm, characterized in that, It has a thickness T in micrometers, and the photoresist film has an absorbance A for light with a wavelength of 405 nanometers, as measured by ultraviolet-visible spectroscopy. 405nm It has an absorbance of A for light with a wavelength of 436 nanometers. 436nm It has an absorbance of A for light with a wavelength of 365 nanometers. 365nm , of which 0 405nm / T≦0.006and0 436nm / T≦0.004,0 365nm / T≦0.010, and the thickness T is between 60 micrometers and 600 micrometers.​​​ This ultraviolet-visible spectroscopy was performed using an ultraviolet-visible spectrophotometer under the following conditions: the photoresist film was placed perpendicular to the incident light source; a diffraction grating was used as the spectrometer; the test temperature was 25°C; the test pressure was 1 atm; the analysis mode was absorbance; the scanning wavelength range was 190 nm to 1100 nm; the blank sample was air; the scanning speed was 2200 nm / min; the lamp source switching wavelength from deuterium lamp to tungsten filament lamp was 340.8 nm; the sampling interval was 0.2 nm; and the slit width was 2.0 nm.

2. The photoresist film as described in claim 1, characterized in that, It is a negative photoresist film.

3. The photoresist film as described in claim 1, characterized in that, 0 405nm / T≦0.002and0 436nm / T≦0.001.​​ 4. The photoresist film as described in claim 1, characterized in that, It includes: (A) Alkali-soluble polymers; (B) Compounds containing ethylene-containing unsaturated double bonds; and (C) Photopolymerization initiator.

5. The photoresist film as described in claim 4, characterized in that, The ethylene-containing unsaturated double bond compound (B) contains a bifunctional acrylic compound.

6. The photoresist film as described in claim 5, characterized in that, The content of the difunctional acrylic compound is 60% by weight or more, based on the total weight of the ethylene-containing unsaturated double bond compound (B).

7. A composite membrane, characterized in that, It includes: The photoresist film as described in any one of claims 1 to 6; and A protective film is formed on at least one surface of the photoresist film.

8. The composite membrane as described in claim 7, characterized in that, The protective film is selected from the following group: polyethylene terephthalate film, polyolefin film and the aforementioned composites.

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