Infrared light cut filter, filter for solid-state imaging device, solid-state imaging device, and method for manufacturing filter for solid-state imaging device

Abstract

To provide an infrared ray cut filter, a filter for a solid-state image sensor, a solid-state image sensor, and a method for manufacturing a filter for a solid-state image sensor that can achieve both developability and infrared ray absorptive power of the infrared ray cut filter.SOLUTION: An infrared ray cut filter 13 includes: a cyanine dye including polymethine, cations located at terminals of polymethine and having heterocycles containing nitrogen, and tris(pentafluoroethyl)trifluorophosphate anions; a polymer including a repeating unit represented by the following formula (1) or the following formula (2); and a naphthoquinonediazide compound.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an infrared light cut filter, a filter for a solid-state imaging device, a solid-state imaging device, and a method for manufacturing a filter for a solid-state imaging device. [Background technology]

[0002] Solid-state imaging devices such as CMOS image sensors and CCD image sensors include photoelectric conversion elements that convert light intensity into electrical signals. One example of a solid-state imaging device is capable of detecting light corresponding to multiple colors. The solid-state imaging device includes a color filter and a photoelectric conversion element for each color, and detects light of each color using the photoelectric conversion element for each color (see, for example, Patent Document 1). Another example of a solid-state imaging device includes an organic photoelectric conversion element and an inorganic photoelectric conversion element, and detects light of each color using the photoelectric conversion element without using a color filter (see, for example, Patent Document 2).

[0003] The solid-state imaging device includes an infrared light cut filter on a photoelectric conversion element. The infrared light absorbing dye in the infrared light cut filter absorbs infrared light, thereby cutting off infrared light that can be detected by each photoelectric conversion element. This improves the detection accuracy of visible light in each photoelectric conversion element. The infrared light cut filter contains, for example, a cyanine dye, which is an infrared light absorbing dye (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-060176 [Patent Document 2] Japanese Patent Application Publication No. 2018-060910 [Patent Document 3] Japanese Patent Application Laid-Open No. 2007-219114 Summary of the Invention [Problem to be solved by the invention]

[0005] The infrared cut filter included in a solid-state imaging device may require patterning depending on the layer structure of the solid-state imaging device. For example, photolithography or dry etching can be used as a method for patterning a thin film such as an infrared cut filter. Among these, photolithography does not require processing under vacuum, and therefore can reduce the cost of manufacturing a solid-state imaging device compared to dry etching. Therefore, the infrared cut filter is required to be patternable by photolithography, in other words, to have developability by photolithography.

[0006] There are two types of photolithographic transfer methods: negative and positive. In negative photolithography, the exposed portions of the object to be patterned form the desired pattern. In contrast, in positive photolithography, the unexposed portions of the object to be patterned form the desired pattern. In patterning an infrared cut filter, the infrared cut filter that is the object to be exposed contains a cyanine dye. The cyanine dye contained in the infrared cut filter may be deteriorated by exposure to light. Therefore, from the viewpoint of suppressing deterioration of the cyanine dye, it is preferable to select a positive photolithography transfer method when patterning an infrared cut filter by photolithography.

[0007] On the other hand, positive resists containing naphthoquinone diazide compounds and novolac phenolic resins are widely used as resists for forming semiconductor devices. However, when an infrared cut filter is formed using a positive resist containing novolac phenolic resins, the cyanine dyes may remain in an aggregated state due to the difference in polarity between the novolac phenolic resins and the cyanine dyes. This reduces the infrared light absorption ability of the cyanine dyes contained in the infrared cut filter. [Means for solving the problem]

[0008] The infrared light cut filter for solving the above-described problems includes a polymethine, a cyanine dye containing a tris(pentafluoroethyl)trifluorophosphate anion and a cation having a nitrogen-containing heterocycle, the cation being located at each terminal of the polymethine, a polymer containing a repeating unit represented by the following formula (1) or (2), and a naphthoquinone diazide compound.

[0009] [ka]

[0010] [ka]

[0011] In formula (1), A is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and R1 is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. The substituted alkyl group is an alkyl group in which an atom contained in the alkyl group is substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The substituted aryl group is an aryl group in which an atom contained in the aryl group is substituted with a halogen atom, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, or an amide group.

[0012] In formula (2), A is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, B is a phenylene group, and R1 is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. The substituted alkyl group is an alkyl group in which an atom contained in the alkyl group is substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The substituted aryl group is an aryl group in which an atom contained in the aryl group is substituted with a halogen atom, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, or an amide group. m is 0 or 1.

[0013] A method for manufacturing a filter for a solid-state imaging device that solves the above problem includes forming an infrared light cut filter that includes a cyanine dye containing polymethine, a cation having two nitrogen-containing heterocycles located at each end of the polymethine, and a tris(pentafluoroethyl)trifluorophosphate anion, a polymer containing a repeating unit represented by formula (1) or (2), and a naphthoquinone diazide compound, and patterning the infrared light cut filter by photolithography.

[0014] According to the manufacturing method of the infrared cut filter and the filter for a solid-state imaging device, the polymer contains a repeating unit derived from the above-mentioned formula (1) or a repeating unit derived from the above-mentioned formula (2). The monomer represented by the above-mentioned formula (1) contains a sulfonamide structure (—SO—N—) exhibiting acidity. This allows naphthoquinone diazide in the naphthoquinone diazide compound to interact with the sulfonamide structure, and as a result, a mixture of the polymer and the naphthoquinone diazide compound can be insoluble in an alkaline developer.

[0015] The monomer represented by the above formula (2) contains a sulfonimide structure (—SO2-NH-SO2-) that exhibits acidity. This allows naphthoquinone diazide in the naphthoquinone diazide compound to interact with the sulfonimide structure, and as a result, the mixture of the polymer and the naphthoquinone diazide compound can be insoluble in an alkaline developer.

[0016] Furthermore, when the naphthoquinone diazide compound is converted to indene carboxylic acid by exposure to light, the indene carboxylic acid does not interact with the sulfonamide structure or sulfonimide structure of the polymer, which allows the mixture of the polymer and the naphthoquinone diazide compound to be soluble in an acrylic developer.

[0017] Furthermore, polymers containing repeating units derived from formula (1) or repeating units derived from formula (2) have high compatibility with cyanine dyes. This makes it possible to suppress association of the cyanine dyes when the polymer is mixed with the cyanine dye. As a result, it is possible to suppress a decrease in the infrared light absorption ability of the cyanine dye in an infrared light cut filter.

[0018] In the infrared cut filter, the repeating unit may be represented by the formula (1), and the polymer may contain 30% by weight or more and 100% by weight or less of the repeating unit.

[0019] In the infrared cut filter, the repeating unit may be represented by the formula (2), and the polymer may contain 30% by weight or more and 100% by weight or less of the repeating unit.

[0020] According to the above infrared cut filter, by containing 30% by weight or more of the repeating unit described above, it is possible to further improve the developability of the infrared cut filter containing the polymer.

[0021] In the infrared cut filter, the weight of the naphthoquinone diazide compound may be 5% by weight or more and 30% by weight or less relative to the weight of the polymer. According to this infrared cut filter, the amount of the naphthoquinone diazide compound is 5% by weight or more, thereby reducing the developability of the unexposed areas and improving the developability of the exposed areas in the infrared cut filter. This increases the precision of the shape of the infrared cut filter. Furthermore, the amount of the naphthoquinone diazide compound is 30% by weight or less, thereby reducing the deterioration of the cyanine dye and reducing the decrease in the absorbance of the infrared cut filter.

[0022] In the infrared cut filter, the average molecular weight of the polymer may be 3,000 or more and 300,000 or less. In this infrared cut filter, since the molecular weight of the polymer is 300,000 or less, the solubility of the acrylic polymer in a developer is less likely to decrease, thereby preventing peeling of the infrared cut filter during development of the infrared cut filter 13. This facilitates patterning of the infrared cut filter. Furthermore, since the molecular weight of the polymer is 3,000 or more, the polymer prevents aggregation of the cyanine dye contained in the infrared cut filter. This prevents a decrease in absorbance in the infrared region of the infrared cut filter.

[0023] A filter for a solid-state imaging device that solves the above problem includes the above infrared cut filter, and a barrier layer that covers the infrared cut filter and prevents transmission of an oxidation source that oxidizes the infrared cut filter.

[0024] A solid-state imaging device for solving the above problem includes a photoelectric conversion element and the above-described filter for solid-state imaging devices. [Effects of the Invention]

[0025] According to the present invention, it is possible to achieve both the developability of the infrared cut filter and the infrared light absorption ability. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is an exploded perspective view showing a structure of a solid-state imaging device according to an embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0027] An infrared light cut filter, a filter for a solid-state imaging device, and a solid-state imaging device according to an embodiment will be described with reference to Figure 1. A manufacturing method, manufacturing example, and test example of the solid-state imaging device and the filter for a solid-state imaging device will be described below. In this embodiment, infrared light refers to light having a wavelength in the range of 0.7 μm to 1 mm, and near-infrared light refers to infrared light having a wavelength in the range of 700 nm to 1100 nm.

[0028] [Solid-state imaging device] The solid-state imaging device will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing the individual layers of a portion of the solid-state imaging device in isolation.

[0029] 1, the solid-state imaging device 10 includes a solid-state imaging device filter 10F and a plurality of photoelectric conversion elements 11. The plurality of photoelectric conversion elements 11 include a red photoelectric conversion element 11R, a green photoelectric conversion element 11G, a blue photoelectric conversion element 11B, and an infrared light photoelectric conversion element 11P. The photoelectric conversion elements 11R, 11G, and 11B for each color measure the intensity of visible light having a specific wavelength associated with that photoelectric conversion element 11R, 11G, and 11B. Each infrared light photoelectric conversion element 11P measures the intensity of infrared light.

[0030] The solid-state imaging device 10 includes a plurality of red photoelectric conversion elements 11R, a plurality of green photoelectric conversion elements 11G, a plurality of blue photoelectric conversion elements 11B, and a plurality of infrared photoelectric conversion elements 11P. For convenience of illustration, Fig. 1 shows a repeating unit of the photoelectric conversion elements 11 in the solid-state imaging device 10.

[0031] The solid-state imaging device filter 10F includes a plurality of visible light filters, an infrared light pass filter 12P, an infrared light cut filter 13, a plurality of visible light microlenses, and an infrared light microlens 15P.

[0032] The visible light color filter is composed of a red filter 12R, a green filter 12G, and a blue filter 12B. The red filter 12R is located on the light incident side of the red photoelectric conversion element 11R. The green filter 12G is located on the light incident side of the green photoelectric conversion element 11G. The blue filter 12B is located on the light incident side of the blue photoelectric conversion element 11B.

[0033] The infrared light pass filter 12P is located on the light incident side of the infrared light photoelectric conversion element 11P. The infrared light pass filter 12P blocks visible light that can be detected by the infrared light photoelectric conversion element 11P from being transmitted to the infrared light photoelectric conversion element 11P. This improves the accuracy of infrared light detection by the infrared light photoelectric conversion element 11P. The infrared light that can be detected by the infrared light photoelectric conversion element 11P is, for example, near-infrared light.

[0034] The infrared light cut filter 13 is located on the light incident side of the color filters 12R, 12G, and 12B. The infrared light cut filter 13 has a through-hole 13H. When viewed from the perspective opposite the plane in which the infrared light cut filter 13 extends, the infrared light pass filter 12P is located within the area defined by the through-hole 13H. On the other hand, when viewed from the perspective opposite the plane in which the infrared light cut filter 13 extends, the infrared light cut filter 13 is located above the red filter 12R, the green filter 12G, and the blue filter 12B.

[0035] The infrared cut filter 13 contains a cyanine dye, which is an infrared light absorbing dye. The cyanine dye has a maximum infrared light absorptance at any wavelength included in the near-infrared light. Therefore, the infrared cut filter 13 can reliably absorb near-infrared light that passes through the infrared cut filter 13. As a result, near-infrared light that can be detected by the photoelectric conversion elements 11 for each color is sufficiently cut by the infrared cut filter 13. The infrared cut filter 13 can have a thickness of, for example, 300 nm or more and 3 μm or less.

[0036] The barrier layer 14 suppresses the transmission of oxidizing sources through the infrared cut filter 13. The oxidizing sources include oxygen and water. The oxygen permeability of the barrier layer 14 is, for example, 5.0 cc / m 2 / day / atm or less. The oxygen permeability is a value in accordance with JIS K7126:2006. The oxygen permeability is 5.0 cc / m 2 Since the infrared cut filter 13 is set to have a relative humidity of 100% or less, the barrier layer 14 prevents the oxidizing source from reaching the infrared cut filter 13, making the infrared cut filter 13 less susceptible to oxidation by the oxidizing source. This makes it possible to improve the light resistance of the infrared cut filter 13.

[0037] The material forming the barrier layer 14 is an inorganic compound. The material forming the barrier layer 14 is preferably a silicon compound. The material forming the barrier layer 14 may be, for example, at least one selected from the group consisting of silicon nitride, silicon oxide, and silicon oxynitride.

[0038] The microlenses are composed of a red microlens 15R, a green microlens 15G, a blue microlens 15B, and an infrared microlens 15P. The red microlens 15R is located on the light incident side relative to the red filter 12R. The green microlens 15G is located on the light incident side relative to the green filter 12G. The blue microlens 15B is located on the light incident side relative to the blue filter 12B. The infrared microlens 15P is located on the light incident side relative to the infrared light pass filter 12P.

[0039] Each of the microlenses 15R, 15G, 15B, and 15P has an incident surface 15S, which is its outer surface. Each of the microlenses 15R, 15G, 15B, and 15P has a refractive index difference between itself and the outside air, which allows light entering the incident surface 15S to be collected toward each of the photoelectric conversion elements 11R, 11G, 11B, and 11P. Each of the microlenses 15R, 15G, 15B, and 15P contains a transparent resin.

[0040] [Infrared cut filter] The infrared cut filter 13 will be described in more detail below. The infrared cut filter 13 includes a cyanine dye, a polymer, and a naphthoquinone diazide compound. The cyanine dye includes a cation and an anion. The cation is a polymethine and has a nitrogen-containing heterocycle located at each end of the polymethine. The anion is a tris(pentafluoroethyl)trifluorophosphate anion.

[0041] The polymer contains a repeating unit represented by the following formula (1) or the following formula (2).

[0042] [ka]

[0043] [ka]

[0044] In formula (1), A is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and R1 is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. The substituted alkyl group is an alkyl group in which an atom contained in the alkyl group is substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The substituted aryl group is an aryl group in which an atom contained in the aryl group is substituted with a halogen atom, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, or an amide group.

[0045] In formula (2), A is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, B is a phenylene group, and R1 is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. The substituted alkyl group is an alkyl group in which an atom contained in the alkyl group is substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The substituted aryl group is an aryl group in which an atom contained in the aryl group is substituted with a halogen atom, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, or an amide group. m is 0 or 1.

[0046] Positive resists containing a naphthoquinone diazide compound and a novolac phenolic resin are widely used as positive resists for forming semiconductor devices. The novolac phenolic resin has multiple phenolic hydroxyl groups. The naphthoquinone diazide compound has multiple atomic groups containing naphthoquinone diazide. In unexposed positive resists, the phenolic hydroxyl groups of the novolac phenolic resin interact with the diazonaphthoquinone of the naphthoquinone diazide compound, rendering the positive resist insoluble in alkaline developers. In contrast, in exposed positive resists, the naphthoquinone diazide in the naphthoquinone diazide compound converts to indenecarboxylic acid, which does not interact with the phenolic hydroxyl groups. This renders the positive resist soluble in alkaline developers.

[0047] When an infrared cut filter is formed using the above-mentioned positive resist, the infrared cut filter has high developability. On the other hand, because the novolac phenolic resin contains a phenolic hydroxyl group, aggregation of the cyanine dye occurs due to the difference in polarity between the phenolic hydroxyl group and the cyanine dye. This results in the formation of an infrared cut filter containing the cyanine dye in an aggregated state. The spectral characteristics of the cyanine dye in an aggregated state differ from those of the cyanine dye in a non-aggregated state, resulting in a decrease in the infrared light absorption ability of the infrared cut filter.

[0048] In this regard, the infrared light cut filter of the present disclosure has a polymer containing a repeating unit derived from the above-mentioned formula (1) or a repeating unit derived from formula (2). The monomer represented by the above-mentioned formula (1) contains a sulfonamide structure (—SO—N—) exhibiting acidity. This allows naphthoquinone diazide in the naphthoquinone diazide compound to interact with the sulfonamide structure, and as a result, a mixture of the polymer and the naphthoquinone diazide compound can be insoluble in an alkaline developer.

[0049] The monomer represented by the above formula (2) contains a sulfonimide structure (—SO2-NH-SO2-) that exhibits acidity. This allows naphthoquinone diazide in the naphthoquinone diazide compound to interact with the sulfonimide structure, and as a result, the mixture of the polymer and the naphthoquinone diazide compound can be insoluble in an alkaline developer.

[0050] Furthermore, when the naphthoquinone diazide compound is converted to indene carboxylic acid by exposure to light, the indene carboxylic acid does not interact with the sulfonamide structure or sulfonimide structure of the polymer, which allows the mixture of the polymer and the naphthoquinone diazide compound to be soluble in an acrylic developer.

[0051] Furthermore, polymers containing repeating units derived from formula (1) or repeating units derived from formula (2) have high compatibility with cyanine dyes. This makes it possible to suppress association of the cyanine dyes when the polymer is mixed with the cyanine dye. As a result, it is possible to suppress a decrease in the infrared light absorption ability of the cyanine dye in an infrared light cut filter.

[0052] The cyanine dye may have a structure shown in formula (3):

[0053] [ka]

[0054] In the above formula (3), X is a methine or polymethine. The hydrogen atoms bonded to the carbon atoms contained in the methine may be substituted with halogen atoms or organic groups. The polymethine may have a cyclic structure containing the carbon atoms forming the polymethine. The cyclic structure may contain three consecutive carbon atoms among the carbon atoms forming the polymethine. When the polymethine has a cyclic structure, the number of carbon atoms in the polymethine may be 5 or more. Each nitrogen atom is contained in a five- or six-membered heterocyclic ring. The heterocyclic ring may be condensed. Y - is an anion.

[0055] The cyanine dye may also have a structure represented by the following formula (4):

[0056] [ka]

[0057] In the above formula (4), n is an integer of 1 or more. n represents the number of repeating units contained in the polymethine chain. R11 and R12 are hydrogen atoms or organic groups. R13 and R14 are hydrogen atoms or organic groups. R13 and R14 are preferably linear or branched alkyl groups having 1 or more carbon atoms. Each nitrogen atom is contained in a five- or six-membered heterocyclic ring. The heterocyclic ring may be condensed.

[0058] In addition, in formula (3), when the polymethine contains a cyclic structure, the cyclic structure may be, for example, a cyclic structure having at least one unsaturated bond such as an ethylenic double bond, and the unsaturated bond may undergo electron resonance as part of the polymethine chain. Such a cyclic structure may be, for example, a cyclopentene ring, a cyclopentadiene ring, a cyclohexene ring, a cyclohexadiene ring, a cycloheptene ring, a cyclooctene ring, a cyclooctadiene ring, or a benzene ring. Any of these cyclic structures may have a substituent.

[0059] In addition, in formula (4), a compound in which n is 1 is a cyanine, a compound in which n is 2 is a carbocyanine, and a compound in which n is 3 is a dicarbocyanine. In formula (4), a compound in which n is 4 is a tricarbocyanine.

[0060] The organic groups of R11 and R12 may be, for example, alkyl groups, aryl groups, aralkyl groups, and alkenyl groups. The alkyl groups may be, for example, methyl groups, ethyl groups, propyl groups, isopropyl groups, n-butyl groups, sec-butyl groups, isobutyl groups, tert-butyl groups, isopentyl groups, neopentyl groups, hexyl groups, cyclohexyl groups, octyl groups, nonyl groups, and decyl groups. The aryl groups may be, for example, phenyl groups, tolyl groups, xylyl groups, and naphthyl groups. The aralkyl groups may be, for example, benzyl groups, phenylethyl groups, and phenylpropyl groups. The alkenyl groups may be, for example, vinyl groups, allyl groups, propenyl groups, isopropenyl groups, butenyl groups, hexenyl groups, cyclohexenyl groups, and octenyl groups.

[0061] At least a portion of the hydrogen atoms in each organic group may be substituted with a halogen atom or a cyano group. The halogen atom may be fluorine, bromine, or chlorine. The organic group after substitution may be, for example, a chloromethyl group, a chloropropyl group, a bromoethyl group, a trifluoropropyl group, or a cyanoethyl group.

[0062] R13 or R14 may be, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a hexyl group, a cyclohexyl group, an octyl group, a nonyl group, and a decyl group.

[0063] The heterocycle containing each nitrogen atom may be, for example, pyrrole, imidazole, thiazole, pyridine, and the like. The cation contained in such a cyanine dye may have a structure represented by the following formula (5) or (6), for example.

[0064] [ka]

[0065] [ka]

[0066] The cation contained in the cyanine dye may have, for example, a structure represented by the following formulas (7) to (46): That is, each nitrogen atom contained in the cyanine dye may be contained in a cyclic structure represented by the following formulas:

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071]

change

[0072]

change

[0073]

change

[0074]

change

[0075]

change

[0076]

change

[0077]

change

[0078]

change

[0079]

change

[0080]

change

[0081]

change

[0082]

change

[0083]

change

[0084]

change

[0085]

change

[0086]

change

[0087]

change

[0088]

change

[0089]

change

[0090]

change

[0091]

change

[0092]

change

[0093]

change

[0094]

change

[0095]

change

[0096]

change

[0097]

change

[0098]

change

[0099]

change

[0100]

change

[0101]

change

[0102]

change

[0103] [ka]

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] The cyanine dye has a maximum absorbance value of infrared light at any wavelength between 700 nm and 1100 nm, and therefore the infrared cut filter 13 can reliably absorb near-infrared light that passes through the infrared cut filter 13. As a result, the infrared cut filter 13 sufficiently cuts out near-infrared light that can be detected by the photoelectric conversion elements 11 for each color.

[0108] The infrared light cut filter 13 may contain only one type of cyanine dye, or may contain two or more types of cyanine dyes. The absorbance Aλ at wavelength λ is calculated by the following formula. Aλ=-log 10 (%T / 100)

[0109] The transmittance T is expressed as the ratio (TL / IL) of the intensity of transmitted light (TL) to the intensity of incident light (IL) when infrared light passes through an infrared cut filter 13 containing a cyanine dye. In the infrared cut filter 13, the intensity of transmitted light when the intensity of incident light is set to 1 is the transmittance T, and the value obtained by multiplying the transmittance T by 100 is the transmittance percentage %T.

[0110] Tris(pentafluoroethyl)trifluorophosphate anion ([(C2F5)3PF3] - ) has a structure represented by the following formula (47):

[0111] [ka]

[0112] In the manufacturing process of the solid-state imaging device 10, the infrared cut filter 13 is heated to about 200° C. When the above-described cyanine dye is heated to about 200° C., the structure of the cyanine dye changes, which may change the transmittance of the cyanine dye to infrared light.

[0113] In this regard, the FAP anion has a molecular weight and molecular structure that allows it to be located in the vicinity of the polymethine chain of the cyanine dye, thereby preventing the polymethine chain of the cyanine dye from being cleaved when the cyanine dye is heated, thereby preventing changes in the infrared light transmittance of the cyanine dye due to heating, and as a result, preventing changes in the infrared light transmittance of the infrared cut filter 13.

[0114] As described above, the infrared cut filter 13 contains a polymer. The polymer contains a repeating unit represented by the following formula (1) or (2).

[0115] [ka]

[0116] [ka]

[0117] In formula (1), A is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and R1 is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. The substituted alkyl group is an alkyl group in which an atom contained in the alkyl group is substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The substituted aryl group is an aryl group in which an atom contained in the aryl group is substituted with a halogen atom, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, or an amide group.

[0118] In formula (2), A is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, B is a phenylene group, and R1 is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. The substituted alkyl group is an alkyl group in which an atom contained in the alkyl group is substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The substituted aryl group is an aryl group in which an atom contained in the aryl group is substituted with a halogen atom, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, or an amide group. m is 0 or 1.

[0119] In formula (1) and formula (2), A is preferably a hydrogen atom or a methyl group. When R1 is an alkyl group, the alkyl group may be linear, branched, or cyclic, and may have 1 to 20 carbon atoms. The alkyl group may be, for example, a methyl group, an ethyl group, an isopropyl group, a cyclohexyl group, or the like.

[0120] When R1 is a substituted alkyl group, for example, atoms contained in the unsubstituted alkyl group described above may be substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The halogen atom may be, for example, chlorine or bromine. The aryl group may be, for example, a phenyl group. The amide group may be, for example, acetamide. The alkoxy group may be, for example, a methoxy group or a butyloxy group. The alkoxycarbonyl group may be, for example, an ethoxycarbonyl group.

[0121] When R1 is an aryl group, the aryl group may be a carbocyclic aromatic group or a heterocyclic aromatic group. The carbocyclic aromatic group may be, for example, a phenyl group, a naphthyl group, an anthranyl group, etc. The heterocyclic aromatic group may be, for example, a benzofuryl group, etc.

[0122] When R1 is a substituted aryl group, the halogen atom may be, for example, chlorine or bromine. The alkyl group having 1 to 10 carbon atoms may be, for example, a methyl group, an ethyl group, a butyl group, etc. The alkoxy group having 1 to 10 carbon atoms may be, for example, a methoxy group, a butyloxy group, etc. The amide group may be, for example, an acetamide group, etc.

[0123] The repeating unit represented by the above formula (1) may have a structure represented by, for example, the following formulas (48) to (97). Among the examples shown below, the repeating unit represented by formula (1) preferably has a structure represented by formulas (48) to (51).

[0124] [ka]

[0125] [ka]

[0126] [ka]

[0127]

change

[0128]

change

[0129]

change

[0130]

change

[0131]

change

[0132]

change

[0133]

change

[0134]

change

[0135]

change

[0136]

change

[0137]

change

[0138]

change

[0139]

change

[0140]

change

[0141]

change

[0142]

change

[0143]

change

[0144]

change

[0145]

change

[0146]

change

[0147]

change

[0148]

change

[0149]

change

[0150]

change

[0151]

change

[0152]

change

[0153]

change

[0154]

change

[0155]

change

[0156]

change

[0157]

change

[0158]

change

[0159]

change

[0160]

change

[0161]

change

[0162]

change

[0163]

change

[0164]

change

[0165]

change

[0166]

change

[0167]

change

[0168]

change

[0169] [ka]

[0170] [ka]

[0171] [ka]

[0172] [ka]

[0173] [ka]

[0174] The repeating unit represented by the above formula (2) may have a structure represented by, for example, the following formulas (98) to (102): Among the examples shown below, the repeating unit represented by formula (2) preferably has a structure represented by formula (98).

[0175] [ka]

[0176] [ka]

[0177] [ka]

[0178] [ka]

[0179] [ka]

[0180] When the polymer contains a repeating unit represented by formula (1), the polymer may contain 30% to 100% by weight of the repeating unit. When the polymer contains a repeating unit represented by formula (2), the polymer may contain 30% to 100% by weight of the repeating unit.

[0181] By containing 30% by weight or more of the above-described repeating unit, the polymer can contain a sulfonamide structure or a sulfonimide structure to such an extent that the developability of the infrared cut filter is further improved. This makes the exposed portion of the infrared cut filter more soluble in an alkaline developer. Furthermore, since a polymer containing the repeating unit represented by the above-described formula (1) or formula (2) has high compatibility with cyanine dyes, when the polymer and the cyanine dye are mixed, the cyanine dyes are less likely to associate. Therefore, the polymer can contain 100% by weight of the above-described repeating unit.

[0182] The polymer may contain both the repeating unit represented by formula (1) and the repeating unit represented by formula (2). The polymer may contain a repeating unit other than the repeating unit represented by the above formula (1) or (2). The monomer from which the repeating unit is derived may be, for example, a styrene-based monomer, a (meth)acrylic monomer, a vinyl ester-based monomer, a vinyl ether-based monomer, a halogen-containing vinyl-based monomer, or a diene-based monomer.

[0183] The styrenic monomers may be, for example, styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, p-methoxystyrene, p-hydroxystyrene, p-acetoxystyrene, vinyltoluene, ethylstyrene, phenylstyrene, and benzylstyrene.

[0184] Examples of the (meth)acrylic monomer include benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, phenoxypolypropylene glycol (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, and 2-(meth)acryloyloxyethyl hydrogen phthalate. , 2-(meth)acryloyloxypropyl hydrogen phthalate, ethoxylated ortho-phenylphenol (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 3-phenoxybenzyl (meth)acrylate, 4-hydroxyphenyl (meth)acrylate, 2-naphthol (meth)acrylate, 4-biphenyl (meth)acrylate, 9-anthrylmethyl (meth)acrylate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl (meth)acrylate, phenol ethylene Oxide (EO) modified acrylate, nonylphenol EO modified acrylate, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl hexahydrophthalate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, 4-t-cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, adamantyl (meth)acrylate, norbornyl (meth)acrylate, tricyclodecanyl ( (meth)acrylate, dicyclopentadienyl (meth)acrylate, tetracyclododecyl (meth)acrylate, glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, 2-ethylglycidyl (meth)acrylate, 2-oxiranylethyl (meth)acrylate, 2-glycidyloxyethyl (meth)acrylate, 3-glycidyloxypropyl (meth)acrylate, glycidyloxyphenyl (meth)acrylate, oxetanyl (meth)acrylate, 3-methyl-3-oxetanyl (meth)acrylate,3-Ethyl-3-oxetanyl (meth)acrylate, (3-methyl-3-oxetanyl)methyl (meth)acrylate, (3-ethyl-3-oxetanyl)methyl (meth)acrylate, 2-(3-methyl-3-oxetanyl)ethyl (meth)acrylate, 2-(3-ethyl-3-oxetanyl)ethyl (meth)acrylate, 2-[(3-methyl-3-oxetanyl)methyloxy]ethyl (meth)acrylate, 2-[(3-ethyl-3-oxetanyl)methyloxy]ethyl (meth)acrylate, 3-[(3-methyl-3-oxetanyl)methyloxy]propyl (meth)acrylate, 3-[(3-ethyl-3-oxetanyl)methyloxy]propyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, etc.

[0185] The vinyl ester monomer may be, for example, vinyl acetate. The vinyl ether monomer may be, for example, vinyl methyl ether. The halogen-containing vinyl monomer may be, for example, vinyl chloride. The diene monomer may be, for example, butadiene, isobutylene, etc.

[0186] The polymer may also contain a monomer for adjusting the polarity of the polymer. The monomer for adjusting the polarity adds an acid group or a hydroxyl group to the copolymer. Such a monomer may be, for example, acrylic acid, methacrylic acid, maleic anhydride, maleic acid half ester, 2-hydroxyethyl acrylate, and 4-hydroxyphenyl (meth)acrylate.

[0187] The polymer may have any of a random copolymer, an alternating copolymer, a block copolymer, and a graft copolymer structure. If the copolymer has a random copolymer structure, the manufacturing process and preparation with the cyanine dye are easy. Therefore, a random copolymer is preferable to other copolymers.

[0188] The polymerization method for obtaining the polymer may be, for example, radical polymerization, cationic polymerization, anionic polymerization, living radical polymerization, living cationic polymerization, or living anionic polymerization. Radical polymerization is preferably selected as the polymerization method for obtaining the polymer because it is easy to produce industrially. Radical polymerization may be solution polymerization, emulsion polymerization, bulk polymerization, or suspension polymerization. Solution polymerization is preferably used for radical polymerization. By using solution polymerization, the average molecular weight of the polymer can be easily controlled. Furthermore, after polymerization of the monomers, the solution containing the copolymer can be used in the form of the solution for producing a filter for a solid-state imaging device.

[0189] In the radical polymerization, the above-mentioned monomer may be diluted with a polymerization solvent, and then a radical polymerization initiator may be added to polymerize the monomer. The polymerization solvent may be, for example, an ester-based solvent, an alcohol ether-based solvent, a ketone-based solvent, an aromatic solvent, an amide-based solvent, or an alcohol-based solvent. Examples of the ester-based solvent include methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl lactate, ethyl lactate, and propylene glycol monomethyl ether acetate. Examples of the alcohol ether-based solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, 3-methoxy-1-butanol, and 3-methoxy-3-methyl-1-butanol. Examples of the ketone-based solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of the aromatic solvent include benzene, toluene, and xylene. Examples of the amide-based solvent include formamide and dimethylformamide. The alcohol-based solvent may be, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, s-butanol, t-butanol, diacetone alcohol, or 2-methyl-2-butanol. Among these, ketone-based solvents and ester-based solvents are preferred because they can be used to manufacture filters for solid-state imaging devices. The above-mentioned polymerization solvents may be used alone or in combination of two or more.

[0190] In radical polymerization, the amount of polymerization solvent used is not particularly limited. When the total amount of monomers is set to 100 parts by weight, the amount of polymerization solvent used is preferably 1 part by weight or more and 1,000 parts by weight or less, and more preferably 10 parts by weight or more and 500 parts by weight or less.

[0191] The radical polymerization initiator may be, for example, a peroxide or an azo compound. The peroxide may be, for example, benzoyl peroxide, t-butyl peroxyacetate, t-butyl peroxybenzoate, or di-t-butyl peroxide. The azo compound may be, for example, azobisisobutyronitrile, azobisamidinopropane salt, azobiscyanovaleric acid (salt), or 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide].

[0192] The amount of radical polymerization initiator used is preferably 0.0001 to 20 parts by weight, more preferably 0.001 to 15 parts by weight, and even more preferably 0.005 to 10 parts by weight, when the total amount of monomers is set to 100 parts by weight. The radical polymerization initiator may be added to the monomers and polymerization solvent before the start of polymerization, or may be added dropwise to the polymerization reaction system. Adding the radical polymerization initiator dropwise to the monomers and polymerization solvent in the polymerization reaction system is preferred because it can suppress heat generation due to polymerization.

[0193] The reaction temperature for radical polymerization is appropriately selected depending on the types of radical polymerization initiator and polymerization solvent, and is preferably 60° C. or higher and 110° C. or lower from the viewpoints of ease of production and reaction controllability.

[0194] The glass transition temperature of the polymer is preferably 75° C. or higher, and more preferably 100° C. or higher. If the glass transition temperature is 75° C. or higher, it is possible to more reliably suppress changes in the infrared light transmittance of the infrared cut filter when the infrared cut filter 13 is heated.

[0195] The average molecular weight of the polymer is preferably from 30,000 to 300,000, and more preferably from 5,000 to 100,000. When the average molecular weight of the polymer is within this range, it is possible to maintain the developability of the infrared cut filter 13 while maintaining the spectral characteristics of the cyanine dye contained in the infrared cut filter 13.

[0196] If the polymer has an average molecular weight exceeding 300,000, the solubility of the polymer in the developer decreases. As a result, when an infrared cut filter 13 containing the polymer is developed, the infrared cut filter 13 is less soluble in the developer, which makes the infrared cut filter 13 more likely to peel off from the support of the infrared cut filter 13. Therefore, if the average molecular weight of the polymer exceeds 300,000, it is not easy to pattern the infrared cut filter 13. In contrast, if the average molecular weight of the polymer is 300,000 or less, the solubility of the polymer in the developer is less likely to decrease, which prevents the infrared cut filter 13 from peeling off during development. Therefore, patterning the infrared cut filter 13 is easy.

[0197] Furthermore, if the average molecular weight of the polymer is less than 3000, it is difficult to obtain the effect of suppressing the aggregation of the cyanine dye contained in the infrared light cut filter 13. As a result, the absorbance of the infrared light cut filter 13 in the infrared region is likely to decrease. On the other hand, if the average molecular weight of the polymer is 3000 or more, the polymer suppresses the aggregation of the cyanine dye contained in the infrared light cut filter 13. As a result, the decrease in the absorbance of the infrared light cut filter 13 in the infrared region is suppressed.

[0198] The average molecular weight of the polymer is a weight average molecular weight. The weight average molecular weight of the polymer can be measured, for example, by gel permeation chromatography. For example, in a radical polymerization reaction, the average molecular weight of the polymer can be controlled by changing the concentrations of the monomer and the radical polymerization initiator in the solution.

[0199] The polymer solution obtained by the production of the polymer contains a polymer and an acrylic monomer. The acrylic monomer is a monomer that was not used in the production of the polymer among the acrylic monomers prepared for the production of the polymer. In the polymer solution, the weight of the polymer is a first weight W1, and the weight of the acrylic monomer is a second weight W2.

[0200] The percentage ({W2 / (W1+W2)}×100) of the second weight W2 to the sum (W1+W2) of the first weight W1 and the second weight W2 is preferably 20% or less. That is, of the monomers prepared for producing the polymer, the amount of residual monomer is preferably 20% or less. When the amount of residual monomer is 20% or less, the improvement in transmittance of the infrared light cut filter is suppressed compared to when the amount of residual monomer is more than 20%.

[0201] The percentage of the second weight W2 relative to the sum of the first weight W1 and the second weight W2 is more preferably 10% or less, and even more preferably 3% or less. The first weight W1 and the second weight W2 can be determined based on the results of polymer analysis. The polymer analysis method may be, for example, gas chromatography-mass spectrometry (GC-MS), nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR), or the like.

[0202] For example, when quantifying the first weight W1 and the second weight using the results of NMR analysis, a spectrum of the polymer solution is first obtained by NMR analysis. Next, in the obtained spectrum, the polymer peak and the acrylic monomer peak are identified. Then, the area ratio of each peak is calculated. The area ratio of the polymer peak is the first weight W1, and the area ratio of the acrylic monomer peak is the second weight W2.

[0203] The percentage of the second weight W2 relative to the sum of the first weight W1 and the second weight W2 may be changed, for example, by changing the polymerization time or the polymerization temperature. Alternatively, the percentage of the second weight W2 relative to the sum of the first weight W1 and the second weight W2 may be changed by changing the concentrations of the monomer and the radical polymerization initiator at the start of the polymerization reaction. Alternatively, the percentage of the second weight W2 relative to the sum of the first weight W1 and the second weight W2 may be changed by changing the purification conditions after the polymerization reaction. Of these, the method of changing the polymerization time is preferred because it provides high control accuracy in changing the proportion of the second weight W2.

[0204] When the radical polymerization initiator used in polymerizing the copolymer is an organic peroxide having an aromatic ring in the side chain, the infrared cut filter preferably contains less than 0.35 parts by weight of the organic peroxide when the copolymer contained in the infrared cut filter is set to 100 parts by weight. By containing less than 0.35 parts by weight of the organic peroxide in the infrared cut filter, deterioration of the spectral characteristics of the infrared cut filter in the visible light region and the infrared light region is suppressed.

[0205] The naphthoquinone diazide compound may be a naphthoquinone diazide-based photosensitizer. The naphthoquinone diazide-based photosensitizer is also used as a photosensitizer for positive photoresists. The naphthoquinone diazide-based photosensitizer may be, for example, an ester compound of naphthoquinone diazide sulfonic acid chloride and a phenolic compound.

[0206] The naphthoquinone diazide sulfonic acid chloride may be, for example, 1,2-naphthoquinone-2-diazide-5-sulfonic acid chloride or 1,2-naphthoquinone-2-diazide-4-sulfonic acid chloride.

[0207] Examples of the phenolic compounds include trihydroxybenzophenone, tetrahydroxybenzophenone, pentahydroxybenzophenone, hexahydroxybenzophenone, (polyhydroxyphenyl)alkane, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,3,4,3'-tetrahydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, and 2,3,4,2'-tetrahydroxy-4'-methylbenzophenone. phenone, 2,3,4,4'-tetrahydroxy-3'-methoxybenzophenone, 2,3,4,2',6'-pentahydroxybenzophenone, 2,4,6,3',4',5'-hexahydroxybenzophenone, 3,4,5,3',4',5'-hexahydroxybenzophenone, bis(2,4-dihydroxyphenyl)methane, bis(p-hydroxyphenyl)methane, tris(p-hydroxyphenyl)methane, 1,1,1-tris(p-hydroxyphenyl)ethane, bis(2,3,4-trihydroxyphenyl)methane, 2,2 -bis(2,3,4-trihydroxyphenyl)propane, 1,1,3-tris(2,5-dimethyl-4-hydroxyphenyl)-3-phenylpropane, 4,4'-[1-{4-(1-[4-hydroxyphenyl]-1-methylethyl)phenyl}ethylidene]bisphenol, bis(2,5-dimethyl-4-hydroxyphenyl)-2-hydroxyphenylmethane, 3,3,3',3'-tetramethyl-1,1'-spirobiindene-5,6,7,5',6',7'-hexanol, 2,2,4-trimethyl-7,2',4'-trihydroxyphenyl hydroxyflavan, 2-methyl-2-(2,4-dihydroxyphenyl)-4-(4-hydroxyphenyl)-7-hydroxychroman, 1-[1-{3-(1-[4-hydroxyphenyl]-1-methylethyl)-4,6-dihydroxyphenyl}-1-methylethyl]-3-[1-{3-(1-[4-hydroxyphenyl]-1-methylethyl)-4,6-dihydroxyphenyl}-1-methylethyl]benzene, 4,6-bis{1-(4-hydroxyphenyl)-1-methylethyl}-1,3-dihydroxybenzene. The infrared light cut filter 13 may contain only one type of naphthoquinone diazide compound, or may contain two or more types.

[0208] The weight of the naphthoquinone diazide compound may be 5% by weight or more and 30% by weight or less relative to the weight of the polymer, i.e., when the total amount of the polymer is set to 100% by weight, the weight of the naphthoquinone diazide compound may be 5% by weight or more and 30% by weight or less relative to the total amount of the polymer.

[0209] When the amount of the naphthoquinone diazide compound is 5% by weight or more, the developability of the unexposed areas is reduced and the developability of the exposed areas is improved in the infrared cut filter 13. This increases the precision of the shape of the infrared cut filter 13. Furthermore, when the amount of the naphthoquinone diazide compound is 30% by weight or less, deterioration of the cyanine dye is suppressed, and therefore a decrease in the absorbance of the infrared cut filter 13 is suppressed.

[0210] The infrared light cut filter 13 may contain a surfactant, a storage stabilizer, an adhesive aid, a heat resistance improver, etc. The infrared light cut filter 13 may contain only one of these, or may contain two or more of them.

[0211] [Method of manufacturing filters for solid-state imaging devices] The method for manufacturing the filter 10F for solid-state imaging devices includes forming an infrared light cut filter 13 and patterning the infrared light cut filter 13 by photolithography. The infrared light cut filter 13 is formed by forming an infrared light cut filter 13 containing a cyanine dye, a polymer, and a naphthoquinone diazide compound. The polymer contains a repeating unit represented by the above-mentioned formula (1) or formula (2). The method for manufacturing the filter 10F for solid-state imaging devices will be described in more detail below.

[0212] The color filters 12R, 12G, and 12B and the infrared light pass filter 12P are formed by forming a coating film containing a colored photosensitive resin and patterning the coating film using photolithography. For example, a coating film containing a red photosensitive resin is formed by applying a coating liquid containing the red photosensitive resin and drying the coating film formed by the application. The red filter 12R is formed by exposing the coating film containing the red photosensitive resin to an area corresponding to the red filter 12R and developing it. The green filter 12G, blue filter 12B, and infrared light pass filter 12P are also formed by the same method as the red filter 12R.

[0213] The pigments contained in the coloring compositions of the red filter 12R, the green filter 12G, and the blue filter 12B may be organic or inorganic pigments, either singly or in combination. The pigments are preferably pigments with high color development and heat resistance, particularly those with high thermal decomposition resistance, and are preferably organic pigments. Examples of organic pigments include phthalocyanine, azo, anthraquinone, quinacridone, dioxazine, anthanthrone, indanthrone, perylene, thioindigo, isoindoline, quinophthalone, and diketopyrrolopyrrole pigments.

[0214] The coloring component contained in the infrared pass filter 12P may be a black pigment or a black dye. The black pigment may be a single pigment having a black color, or a mixture of two or more pigments having a black color. The black dye may be, for example, an azo dye, an anthraquinone dye, an azine dye, a quinoline dye, a perinone dye, a perylene dye, or a methine dye.

[0215] The photosensitive coloring composition of each color further contains a binder resin, a photopolymerization initiator, a polymerizable monomer, an organic solvent, a leveling agent, and the like. When forming the infrared cut filter 13, a coating liquid containing the above-mentioned cyanine dye, polymer, naphthoquinone diazide compound, and organic solvent is applied onto the color filters 12R, 12G, and 12B and the infrared pass filter 12P. This forms the infrared cut filter 13. Next, the infrared cut filter 13 is exposed using a positive photomask. Thereafter, the exposed infrared cut filter 13 is developed using an alkaline developer, and then the developed infrared cut filter 13 is washed with water and dried. The dried infrared cut filter 13 is heated to harden it. This results in the infrared cut filter 13 being patterned.

[0216] The alkaline developer may be an aqueous solution of tetraammonium hydroxide (TMAH). The concentration of the TMAH aqueous solution is not particularly limited as long as it is a concentration that allows development of the infrared cut filter 13. The infrared cut filter 13 may be brought into contact with the developer by a dipping method, a spraying method, a spinning method, or the like.

[0217] The barrier layer 14 is formed by a vapor phase deposition method such as sputtering, CVD, or ion plating, or a liquid phase deposition method such as coating. The barrier layer 14 made of silicon oxide is formed, for example, by sputtering a substrate on which the infrared cut filter 13 is formed using a silicon oxide target. The barrier layer 14 made of silicon oxide is formed, for example, by CVD using silane and oxygen on the substrate on which the infrared cut filter 13 is formed. The barrier layer 14 made of silicon oxide is formed, for example, by applying a coating liquid containing polysilazane, modifying it, and drying the coating. The layer structure of the barrier layer 14 may be a single layer structure made of a single compound, a laminate structure made of a single compound, or a laminate structure made of layers made of different compounds.

[0218] Each of the microlenses 15R, 15G, 15B, and 15P is formed by forming a coating film containing a transparent resin, patterning the coating film using a photolithography method, and reflowing the coating film using a heat treatment. The transparent resin may be, for example, an acrylic resin, a polyamide resin, a polyimide resin, a polyurethane resin, a polyester resin, a polyether resin, a polyolefin resin, a polycarbonate resin, a polystyrene resin, or a norbornene resin.

[0219] [Manufacturing example] A production example of an acrylic polymer for producing an infrared light cut filter will be described with reference to Table 1. When the acrylic polymer is a copolymer produced using two or more monomers, the weight ratio of the repeating units derived from each monomer in the produced copolymer is equal to the weight ratio of each monomer at the time of producing the copolymer.

[0220] In Table 1, Compound A is a monomer from which a repeating unit represented by formula (48) is derived, and Compound B is a monomer from which a repeating unit represented by formula (49) is derived. Compound C is a monomer from which a repeating unit represented by formula (50) is derived. Compound D is a monomer from which a repeating unit represented by formula (98) is derived. Furthermore, MAA is methacrylic acid, and PhMA is phenyl methacrylate.

[0221] [Table 1]

[0222] [Manufacturing Example 1] 150 parts by weight of propylene glycol monomethyl ether acetate (PGMAc) was prepared as a polymerization solvent, and 100 parts by weight of Compound A was prepared as a monomer. Also, 1.5 parts by weight of benzoyl peroxide (BPO) was prepared as a radical polymer. These were placed in a reaction vessel equipped with a stirrer and a reflux condenser, and while introducing nitrogen gas into the reaction vessel, the mixture was stirred and refluxed for 8 hours while heated to 80°C. This yielded a polymer solution containing a homopolymer produced from Compound A. The homopolymer had a weight-average molecular weight of 10,000.

[0223] [Manufacturing Example 2] 50 parts by weight of Compound A and 50 parts by weight of PhMA were prepared as monomers. A polymer solution containing a copolymer formed from Compound A and PhMA was obtained in the same manner as in Production Example 1. The weight-average molecular weight of the copolymer was 11,000.

[0224] [Manufacturing Example 3] 30 parts by weight of Compound A and 70 parts by weight of PhMA were prepared as monomers. A polymer solution containing a copolymer formed from Compound A and PhMA was obtained in the same manner as in Production Example 1. The weight-average molecular weight of the copolymer was 15,000.

[0225] [Manufacturing Example 4] 50 parts by weight of compound B and 50 parts by weight of PhMA were prepared as monomers. A polymer solution containing a copolymer formed from compound B and PhMA was obtained in the same manner as in Production Example 1. The weight-average molecular weight of the polymer was 14,000.

[0226] [Manufacturing Example 5] 50 parts by weight of compound C and 50 parts by weight of PhMA were prepared as monomers. A polymer solution containing a copolymer formed from compound C and PhMA was obtained in the same manner as in Production Example 1. The weight-average molecular weight of the acrylic copolymer was 12,000.

[0227] [Manufacturing Example 6] 50 parts by weight of compound D and 50 parts by weight of PhMA were prepared as monomers. A polymer solution containing an acrylic copolymer formed from compound D and PhMAA was obtained in the same manner as in Preparation Example 1. The weight-average molecular weight of the acrylic copolymer was 10,000.

[0228] [Manufacturing Example 7] 20 parts by weight of Compound A and 80 parts by weight of PhMA were prepared as monomers. A polymer solution containing a copolymer formed from Compound A and PhMA was obtained in the same manner as in Production Example 1. The weight-average molecular weight of the acrylic copolymer was 15,000.

[0229] [Manufacturing Example 8] 50 parts by weight of MAA and 50 parts by weight of PhMA were prepared as acrylic monomers. A polymer solution containing an acrylic copolymer formed from MAA and PhMA was obtained in the same manner as in Preparation Example 1. The weight-average molecular weight of the acrylic copolymer was 15,000.

[0230] [Manufacturing Example 9] 30 parts by weight of MAA and 70 parts by weight of PhMA were prepared as acrylic monomers. A polymer solution containing an acrylic copolymer formed from MAA and PhMA was obtained in the same manner as in Preparation Example 1. The weight-average molecular weight of the acrylic copolymer was 10,000.

[0231] [Manufacturing Example 10] 20 parts by weight of MAA and 80 parts by weight of PhMA were prepared as acrylic monomers. A polymer solution containing an acrylic copolymer formed from MAA and PhMA was obtained in the same manner as in Preparation Example 1. The weight-average molecular weight of the acrylic copolymer was 15,000.

[0232] [Manufacturing Example 11] 15 parts by weight of MAA and 85 parts by weight of PhMA were prepared as acrylic monomers. A polymer solution containing an acrylic copolymer formed from MAA and PhMA was obtained in the same manner as in Preparation Example 1. The weight-average molecular weight of the acrylic copolymer was 11,000.

[0233] [Test Example 1] In each production example, a 25% polymer solution was obtained by diluting the polymer solution so that the weight of the homopolymer or acrylic copolymer relative to the weight of the polymer solution was 25%. The 25% polymer solutions of Production Examples 1 to 11 were used in sequence to obtain the infrared light cut filters of Test Examples 1-1 to 1-11. The infrared light cut filters before exposure in each test example were prepared by the following method.

[0234] A coating solution containing 0.4 g of cyanine dye, 12.5 g of a 25% polymer solution, 0.625 g of a naphthoquinone diazide compound, and 10 g of propylene glycol monomethyl ether acetate was prepared. The cyanine dye used was the dye represented by formula (5) above, and 11 polymer solutions containing the acrylic polymers obtained in Production Examples 1 to 11 were used. The naphthoquinone diazide compound used was an ester of 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol and 1,2-naphthoquinone-2-diazide-5-sulfonic acid chloride. The coating solution was applied to a transparent substrate to form a coating film, which was then heated to 90°C. The coating film was dried, resulting in a pre-exposure infrared cut filter having a thickness of 1.0 μm.

[0235] Also, an infrared cut filter of Test Example 1-12 was obtained by the following method using a novolak-based positive resist (OFPR-800, manufactured by Tokyo Ohka Kogyo Co., Ltd.). A positive resist was diluted with propylene glycol monomethyl ether acetate to a solids content of 25% by weight. Next, 0.4 g of a cyanine dye was mixed with the diluted positive resist to prepare a coating solution. The cyanine dye used was the dye represented by the above formula (5). The coating solution was applied to a transparent substrate to form a coating film, which was then heated to 90°C. The coating film was dried to obtain an infrared light cut filter of Test Example 1-12 having a thickness of 1.0 μm.

[0236] [Evaluation of developability] The development rate (R1) of the infrared cut filter in the exposed area to the alkaline developer and the development rate (R2) of the infrared cut filter in the unexposed area to the alkaline developer were calculated using the method described below. The ratio (R1 / R2) of the development rate (R1) in the exposed area to the development rate (R2) in the unexposed area was calculated as the development contrast.

[0237] [Development rate in exposed area R1] The unexposed infrared cut filter was exposed using an exposure machine (FPA-5510iZ, manufactured by Canon Inc.). At this time, the exposure dose of the exposure machine was 5000 J / m 2 Next, tetraammonium hydroxide (TMAH) was added to pure water to prepare an alkaline developer with a concentration of 1.0 wt %. The exposed infrared cut filter was then immersed in the alkaline developer for a predetermined time ranging from 1 to 30 seconds, and then washed with pure water for 30 seconds. The thickness of the infrared cut filter after immersion in the alkaline developer was then measured. The development rate R1 (nm / s) of the exposed area was calculated using the following formula based on the change in the thickness of the infrared cut filter before and after immersion in the alkaline developer and the time the infrared cut filter was immersed in the alkaline developer. Development rate R1 (nm / s) = thickness change / immersion time

[0238] In the formula for calculating the development speed R1, the change in thickness was calculated by subtracting the thickness of the infrared cut filter after immersion in the alkaline developer from the thickness of the infrared cut filter before immersion in the alkaline developer. As described above, the thickness of the infrared cut filter before immersion in the alkaline developer was 1.0 μm. As described above, the immersion time was set to a predetermined time within the range of 1 second to 30 seconds.

[0239] [Development rate in unexposed area R2] TMAH was adjusted with pure water to a TMAH concentration of 1.0 wt %, thereby obtaining an alkaline developer. An unexposed infrared cut filter was then immersed in the alkaline developer for a predetermined time ranging from 1 to 30 seconds, and then the infrared cut filter was washed with pure water for 30 seconds. The thickness of the infrared cut filter after immersion in the alkaline developer was then measured. Based on the change in the thickness of the infrared cut filter before and after immersion in the alkaline developer and the time the infrared cut filter was immersed in the alkaline developer, the development rate R2 (nm / s) of the unexposed area was calculated using the following formula: Development rate R2 (nm / s) = thickness change / immersion time

[0240] In the formula for calculating the development speed R2, the change in thickness was calculated by subtracting the thickness of the infrared cut filter after immersion in the alkaline developer from the thickness of the infrared cut filter before immersion in the alkaline developer. As described above, the thickness of the infrared cut filter before immersion in the alkaline developer was 1.0 μm. As described above, the immersion time was set to a predetermined time within the range of 1 second to 30 seconds.

[0241] [Ratio of development rate R1 to development rate R2] The development contrast was calculated as the ratio of the development speed R1 in the exposed area to the development speed R2 in the unexposed area using the following formula.

[0242] Development contrast = development speed of exposed area R1 / development speed of unexposed area R2 In addition, when the development contrast of the infrared cut filter is 40 or more, the accuracy of the pattern formation is good in the infrared cut filter. In other words, the infrared cut filter has high developability.

[0243] [Spectral characteristics] The unexposed infrared cut filter was heated to 200°C to cure the infrared cut filter. The transmittance of the cured infrared cut filter for light having wavelengths from 350 nm to 1150 nm was measured using a spectrophotometer (U-4100, manufactured by Hitachi High-Technologies Corporation). This resulted in a transmittance spectrum for each infrared cut filter. The transmittance spectrum for the cyanine dye represented by the above formula (5) has the lowest transmittance at 950 nm. An infrared cut filter with a transmittance of 20% or less at 950 nm has favorable infrared light absorption ability when applied to a solid-state imaging device.

[0244] [Evaluation results] The evaluation results of the development speed R1, development speed R2, development contrast, and spectral characteristics of the infrared cut filter of each test example are shown in Table 2 below.

[0245] [Table 2]

[0246] As shown in Table 2, the infrared light cut filters of Test Examples 1-1 to 1-7 were all found to have a development contrast of 40 or more. That is, the infrared light cut filters of Test Examples 1-1 to 1-7 were found to have high developability in patterning by photolithography. Furthermore, the infrared light cut filters of Test Examples 1-1 to 1-7 were found to have a transmittance of 20% or less for light having a wavelength of 950 nm. That is, the infrared light cut filters of Test Examples 1-1 to 1-7 were found to have infrared light absorption ability suitable for use as infrared light cut filters.

[0247] The infrared cut filters of Test Examples 1-10 and 1-11 had a transmittance of 10% for light having a wavelength of 950 nm, and therefore were found to have infrared absorption capabilities suitable for use as infrared cut filters. However, the infrared cut filters of Test Examples 1-10 and 1-11 had a development contrast of 15 or less, and therefore were found to have poorer developability in photolithographic patterning than the infrared cut filters of Test Examples 1-1 to 1-7.

[0248] Furthermore, it was confirmed that the infrared light cut filters of Test Examples 1-8 and 1-9 had a transmittance of 60% or more for light having a wavelength of 950 nm and a development contrast of less than 10. In other words, it was confirmed that the infrared light cut filters of Test Examples 1-8 and 1-9 had lower infrared light absorption ability as infrared light cut filters and lower developability in patterning by photolithography compared to the infrared light cut filters of Test Examples 1-1 to 1-7.

[0249] The infrared cut filter of Test Example 1-12 was found to have a development contrast of 158. That is, the infrared cut filter of Test Example 1-13 was found to have high developability in patterning by photolithography. On the other hand, the infrared cut filter of Test Example 1-12 had a transmittance of 80% for light having a wavelength of 950 nm, and it was found that the infrared cut filter of Test Example 1-12 had low infrared light absorption ability as an infrared cut filter.

[0250] Thus, it was found that by including a repeating unit represented by formula (1) or formula (2) in the polymer, it is possible to achieve both developability and infrared light absorption ability in the infrared light cut filter. It was also found that by including 30% by weight or more of the repeating unit represented by formula (1) in the acrylic polymer, the infrared light cut filter has higher developability. It was also found that, from the viewpoint of developability, it is more preferable for the polymer to include 50% by mass or less of the repeating unit represented by formula (1). That is, it was found that by including 30% by weight or more and 50% by weight or less of the repeating unit represented by formula (1), higher developability can be obtained.

[0251] [Test Example 2] [Naphthoquinone diazide compound content] By using the acrylic copolymer of Production Example 2, seven types of infrared cut filters described below were obtained.

[0252] A coating solution containing 0.4 g of cyanine dye, 12.5 g of a 25% polymer solution, a naphthoquinone diazide compound, and 10 g of propylene glycol monomethyl ether acetate was prepared. The cyanine dye used was the dye represented by formula (5). The naphthoquinone diazide used was an ester of 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol and 1,2-naphthoquinone-2-diazide-5-sulfonic acid chloride. The coating solution was applied to a transparent substrate to form a coating film, which was then heated to 90°C. The coating film was then dried, resulting in a 1.0 μm-thick infrared cut filter.

[0253] The amount of the naphthoquinone diazide compound was changed to seven different amounts as shown in Table 3 below, thereby obtaining seven types of infrared cut filters.

[0254] [Table 3]

[0255] As shown in Table 3, in Test Example 2-1, the amount of naphthoquinone diazide compound was set to 0.095 g, and thus, the amount of naphthoquinone diazide compound was set to 3 wt % when the acrylic copolymer was taken as 100 wt %. In Test Example 2-2, the amount of naphthoquinone diazide compound was set to 0.155 g, and thus, the amount of naphthoquinone diazide compound was set to 5 wt % when the acrylic copolymer was taken as 100 wt %.

[0256] In Test Example 2-3, the amount of naphthoquinone diazide compound was set to 0.315 g, which resulted in a 10 mass % naphthoquinone diazide compound amount when the acrylic copolymer was taken as 100 wt %. In Test Example 2-4, the amount of naphthoquinone diazide compound was set to 0.625 g, which resulted in a 20 mass % naphthoquinone diazide compound amount when the acrylic copolymer was taken as 100 wt %.

[0257] In Test Example 2-5, the amount of naphthoquinone diazide compound was set to 0.950 g, which resulted in a 30 wt% naphthoquinone diazide compound amount relative to 100 wt% acrylic copolymer. In Test Example 2-6, the amount of naphthoquinone diazide compound was set to 1.100 g, which resulted in a 35 wt% naphthoquinone diazide compound amount relative to 100 wt% acrylic copolymer. In Test Example 2-7, the amount of naphthoquinone diazide compound was set to 1.250 g, which resulted in a 40 wt% naphthoquinone diazide compound amount relative to 100 wt% acrylic copolymer.

[0258] [Evaluation results] The development speed R1 of the exposed area, the development speed R2 of the unexposed area, and the development contrast were calculated for the infrared cut filter of each test example using the same method as described in Test Example 1. The spectral characteristics of the infrared cut filter of each test example were also measured using the same method as described in Test Example 1. The evaluation results for the development speed R1, the development speed R2, the development contrast, and the spectral characteristics are shown in Table 4 below.

[0259] [Table 4]

[0260] As shown in Table 4, the infrared light cut filters of Test Examples 2-1 to 2-7 were found to suppress an extreme decrease in either the development contrast or the spectral characteristics, compared to when the acrylic polymer did not contain the repeating unit represented by Formula (1). In other words, the infrared light cut filters of Test Examples 2-1 to 2-7 were found to achieve both developability and infrared light absorption ability. In particular, Test Example 2-1 was found to have a development contrast that was higher or similar to that when the amount of naphthoquinone diazide compound was at least equal to that when the acrylic polymer did not contain the repeating unit represented by Formula (1).

[0261] Furthermore, it was confirmed that the infrared cut filters of Test Examples 2-2 to 2-7, that is, when the acrylic copolymer is taken as 100% by weight, the amount of naphthoquinone diazide compound is 5% by weight or more, can further enhance the development contrast of the infrared cut filters. Specifically, it was confirmed that the infrared cut filters exhibit a development contrast of 40 or more.

[0262] On the other hand, according to the infrared cut filters of Test Examples 2-1 to 2-5, that is, when the acrylic copolymer is taken as 100 wt %, by setting the amount of naphthoquinone diazide compound to 30 mass % or less, it was confirmed that the infrared light absorption ability of the infrared cut filter was further improved. Specifically, it was confirmed that the transmittance of light having a wavelength of 950 nm in the infrared cut filter was 20% or less.

[0263] Thus, from the viewpoint of achieving both the developability and the infrared light absorption ability of the infrared cut filter, it was found that the amount of the naphthoquinone diazide compound is preferably 5% by weight or more and 30% by weight when the acrylic copolymer is taken as 100% by weight.

[0264] As described above, according to one embodiment of the infrared light cut filter, the filter for a solid-state imaging device, the solid-state imaging device, and the method for manufacturing a filter for a solid-state imaging device, the following effects can be obtained.

[0265] (1) A polymer containing a repeating unit represented by formula (1) contains a sulfonamide structure exhibiting acidity. Also, a polymer containing a repeating unit represented by formula (2) contains a sulfonimide structure exhibiting acidity. Therefore, a mixture containing the polymer and a naphthoquinone diazide compound can be developed with an alkaline developer.

[0266] (2) A polymer containing a repeating unit represented by formula (1) or (2) has high compatibility with a cyanine dye, and therefore can suppress the aggregation of the cyanine dye, thereby suppressing a decrease in the infrared light absorption ability of the cyanine dye in an infrared light cut filter.

[0267] (3) When the acrylic polymer contains 30% by weight or more of the repeating unit described above, it is possible to further improve the developability of the infrared cut filter 13 containing the acrylic polymer.

[0268] (4) If the molecular weight of the acrylic polymer is 300,000 or less, the solubility of the acrylic polymer in the developer is less likely to decrease, which prevents the infrared cut filter 13 from peeling off during development of the infrared cut filter 13. This makes it easy to pattern the infrared cut filter 13.

[0269] (5) When the molecular weight of the acrylic polymer is 3000 or more, the acrylic polymer suppresses aggregation of the cyanine dye contained in the infrared cut filter 13. This suppresses a decrease in absorbance in the infrared region of the infrared cut filter 13.

[0270] (6) When the amount of the naphthoquinone diazide compound is 5% by weight or more, the developability of the unexposed areas in the infrared cut filter 13 is reduced and the developability of the exposed areas is improved. This increases the precision of the shape of the infrared cut filter 13. Furthermore, when the amount of the naphthoquinone diazide compound is 30% by weight or less, deterioration of the cyanine dye is suppressed, and therefore a decrease in the absorbance of the infrared cut filter 13 is suppressed.

[0271] The above-described embodiment can be modified as follows. [Barrier layer] The barrier layer 14 is not limited to being disposed between the infrared cut filter 13 and the microlenses 15R, 15G, 15B, and 15P, but may be disposed on the outer surface of each of the microlenses 15R, 15G, 15B, and 15P.

[0272] The solid-state imaging device 10 may include an anchor layer between the barrier layer 14 and the layer below the barrier layer 14. In this case, the anchor layer improves adhesion between the barrier layer 14 and the layer below the barrier layer 14. The solid-state imaging device 10 may also include an anchor layer between the barrier layer 14 and the layer above the barrier layer 14. In this case, the anchor layer improves adhesion between the barrier layer and the layer above the barrier layer. The anchor layer may be formed from a material such as a polyfunctional acrylic resin or a silane coupling agent.

[0273] The layer structure of the barrier layer 14 may be a single layer structure made of a single compound, a laminated structure of layers made of a single compound, or a laminated structure of layers made of different compounds.

[0274] The barrier layer 14 may function as a planarizing layer that fills in the step formed by the surface of the infrared cut filter 13 and the surface of the infrared pass filter 12P. The filter 10F for solid-state imaging devices does not have to have the barrier layer 14. Even in this case, it is possible to obtain the effect equivalent to the above-mentioned (1).

[0275] [others] The thickness of each of the color filters 12R, 12G, and 12B may be equal to or different from that of the infrared pass filter 12P. The thickness of each of the color filters 12R, 12G, and 12B may be, for example, 0.5 μm or more and 5 μm or less.

[0276] The color filter may be a three-color filter including a cyan filter, a yellow filter, and a magenta filter. Alternatively, the color filter may be a four-color filter including a cyan filter, a yellow filter, a magenta filter, and a black filter. Alternatively, the color filter may be a four-color filter including a transparent filter, a yellow filter, a red filter, and a black filter.

[0277] The color filters 12R, 12G, and 12B may have the same thickness as the infrared pass filter 12P, or may have different thicknesses. The thickness of each of the color filters 12R, 12G, and 12B may be, for example, 0.5 μm or more and 5 μm or less.

[0278] The material forming the infrared light cut filter 13 may contain additives such as a light stabilizer, an antioxidant, a heat stabilizer, and an antistatic agent, and the infrared light cut filter 13 may contain additives that provide functions other than the function of absorbing infrared light.

[0279] In the solid-state imaging device 10, the oxygen permeability of the laminated structure located on the side of the incident surface 15S with respect to the infrared light cut filter 13 is 5.0 cc / m 2 For example, the laminated structure may be a planarization layer, an adhesion layer, or other functional layer, and each microlens may have an oxygen permeability of 5.0 cc / m 2 It may be less than / day / atm.

[0280] The solid-state imaging element 10 may include a bandpass filter on the light incident side of the multiple microlenses. The bandpass filter transmits only light having specific wavelengths of visible light and near-infrared light, and has a similar function to the infrared light cut filter 13. That is, the bandpass filter can cut out unnecessary infrared light that may be detected by the color photoelectric conversion elements 11R, 11G, and 11B. This improves the detection accuracy of visible light by the color photoelectric conversion elements 11R, 11G, and 11B, as well as the detection accuracy of near-infrared light having wavelengths in the 850 nm or 940 nm band that is the target of detection by the infrared photoelectric conversion element 11P. [Explanation of symbols]

[0281] 10...Solid-state image sensor 10F...Solid-state image sensor filter 11...Photoelectric conversion element 12R...Red filter 12G...Green filter 12B...Blue filter 12P...Infrared light pass filter 13...Infrared light blocking filter 13H...Through hole 14...Barrier layer 15B...Blue microlens 15G...Green microlens 15P...Infrared light microlens 15R...Red microlens

Claims

1. a cyanine dye comprising a polymethine, a cation having a nitrogen-containing heterocycle located at each end of the polymethine, and a tris(pentafluoroethyl)trifluorophosphate anion; a polymer containing a repeating unit represented by the following formula (1) or the following formula (2); a naphthoquinone diazide compound, Infrared light blocking filter. 【Chemistry 1】 【Chemistry 2】 In formula (1), A is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and R1 is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. The substituted alkyl group is an alkyl group in which an atom contained in the alkyl group is substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The substituted aryl group is an aryl group in which an atom contained in the aryl group is substituted with a halogen atom, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, or an amide group. In formula (2), A is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, B is a phenylene group, and R1 is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. The substituted alkyl group is an alkyl group in which an atom contained in the alkyl group is substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The substituted aryl group is an aryl group in which an atom contained in the aryl group is substituted with a halogen atom, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, or an amide group. m is 0 or 1.

2. The repeating unit is represented by the formula (1), The polymer contains 30% by weight or more and 100% by weight or less of the repeating unit. The infrared light cut filter according to claim 1 .

3. The repeating unit is represented by the formula (2), The polymer contains 30% by weight or more and 100% by weight or less of the repeating unit. The infrared light cut filter according to claim 1 .

4. The weight of the naphthoquinone diazide compound is 5% by weight or more and 30% by weight or less based on the weight of the polymer. The infrared light cut filter according to claim 1 .

5. The average molecular weight of the polymer is 3,000 or more and 300,000 or less. The infrared light cut filter according to claim 1 .

6. The infrared light cut filter according to any one of claims 1 to 5, a barrier layer that covers the infrared light cut filter and suppresses the transmission of an oxidation source that oxidizes the infrared light cut filter. Filter for solid-state imaging devices.

7. a photoelectric conversion element; and the filter for a solid-state imaging device according to claim 6. Solid-state imaging element.

8. forming an infrared light cut filter comprising: a cyanine dye containing polymethine, a cation having two nitrogen-containing heterocycles located at each end of the polymethine, and a tris(pentafluoroethyl)trifluorophosphate anion; a polymer containing a repeating unit represented by the following formula (1) or (2); and a naphthoquinone diazide compound; and patterning the infrared light cut filter by photolithography. A method for manufacturing a filter for a solid-state imaging device. 【Transformation 3】 【Chemistry 4】 In formula (1), A is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and R1 is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. The substituted alkyl group is an alkyl group in which an atom contained in the alkyl group is substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The substituted aryl group is an aryl group in which an atom contained in the aryl group is substituted with a halogen atom, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, or an amide group. In formula (2), A is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, B is a phenylene group, and R1 is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. The substituted alkyl group is an alkyl group in which an atom contained in the alkyl group is substituted with a halogen atom, an aryl group, an amide group, an alkoxy group, or an alkoxycarbonyl group. The substituted aryl group is an aryl group in which an atom contained in the aryl group is substituted with a halogen atom, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, or an amide group. m is 0 or 1.

Images