Compositions for near-infrared blocking filters, and image sensors including near-infrared blocking filters

Abstract

To provide a composition for a near-infrared blocking filter and an image sensor including the near-infrared blocking filter.SOLUTION: An image sensor is provided, comprising a substrate having a first surface, a second surface opposite the first surface, and a plurality of pixels, each having a photoelectric conversion area; and a near-infrared blocking filter provided on the second surface of the substrate, the near-infrared blocking filter comprising a mixture of a first cyanine dye represented by general formula 1, a second cyanine dye represented by general formula 2, and a third cyanine dye represented by general formula 3 or 4.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a composition for a near-infrared ray blocking filter and an image sensor including the near-infrared ray blocking filter, and more particularly to an image sensor including a near-infrared ray blocking filter containing a cyanine dye. [Background technology]

[0002] A CMOS (complementary metal oxide semiconductor) image sensor includes a photoelectric conversion region formed within a silicon substrate, which has a relatively high sensitivity to the infrared region. When near-infrared or infrared light penetrates the silicon substrate, red image distortion occurs. Therefore, a method of absorbing infrared or near-infrared light by placing a near-infrared blocking filter under the module lens has been proposed. However, the relatively large size of the near-infrared blocking filter restricts the miniaturization of image sensors. In addition, the deviation in blocking characteristics depending on the angle of incidence is relatively large, which can lead to issues such as noise generation due to light leakage. Summary of the Invention [Problem to be solved by the invention]

[0003] An object of the present invention is to provide a composition for a near-infrared blocking filter having improved blocking properties, and an image sensor including a near-infrared blocking filter formed using the composition. [Means for solving the problem]

[0004] A composition for a near-infrared blocking filter according to an exemplary embodiment for solving the above problems is a composition for a near-infrared blocking filter used in an image sensor, and includes a mixture of a first cyanine dye, a second cyanine dye, and a third cyanine dye, wherein the first cyanine dye is represented by the following Chemical Formula 1, the second cyanine dye is represented by the following Chemical Formula 2, and the third cyanine dye is represented by the following Chemical Formula 3 or Chemical Formula 4:

[0005] [ka] (In Chemical Formula 1, R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms; R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R4 is an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group; and X is a non-metallic element.)

[0006] [ka] (In Chemical Formula 2, R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms; R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R4 is an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group; and X is a non-metallic element.)

[0007] [ka] (In Chemical Formula 3, R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms; R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R4 is an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group; and X is a non-metallic element.)

[0008] [ka] (In Chemical Formula 4, R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms; R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; and X is a non-metallic element.)

[0009] According to an exemplary embodiment for solving the above problems, an image sensor includes: a substrate having a first surface and a second surface opposite to the first surface, the substrate including a plurality of pixels, each of the plurality of pixels including a photoelectric conversion region; and a near-infrared blocking filter disposed on the second surface of the substrate, the near-infrared blocking filter including a mixture of a first cyanine dye, a second cyanine dye, and a third cyanine dye, wherein the first cyanine dye is represented by Chemical Formula 1, the second cyanine dye is represented by Chemical Formula 2, and the third cyanine dye is represented by Chemical Formula 3 or Chemical Formula 4.

[0010] According to an exemplary embodiment for solving the above-described problems, an image sensor includes: a substrate including a first surface and a second surface opposite to the first surface, the substrate including a plurality of pixels, each of the plurality of pixels including a photoelectric conversion region; an anti-reflection layer disposed on the second surface of the substrate; a color filter disposed on the anti-reflection layer; a near-infrared blocking filter disposed on the color filter; and a microlens disposed on the near-infrared blocking filter, wherein the near-infrared blocking filter includes a mixture of a first cyanine dye, a second cyanine dye, and a third cyanine dye, and the near-infrared blocking filter is configured such that the first cyanine dye, the second cyanine dye, and the third cyanine dye are arranged in an a:b:c ratio. the first cyanine dye is a heptamethine cyanine dye and is configured to absorb light having a wavelength in the range of 750 to 850 nm, and the maximum absorption wavelength of the first cyanine dye is 760 to 810 nm; the second cyanine dye is a heptamethine cyanine dye and is configured to absorb light having a wavelength in the range of 850 to 950 nm, and the maximum absorption wavelength of the second cyanine dye is 870 to 920 nm; and the third cyanine dye is a heptamethine cyanine dye and is configured to absorb light having a wavelength in the range of 950 to 1100 nm, and the maximum absorption wavelength of the third cyanine dye is 1000 to 1100 nm. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a graph showing the light absorption characteristics of a near-infrared blocking filter composition according to an exemplary embodiment. [Figure 2] 1 is a graph showing the light absorption characteristics of a near-infrared blocking filter composition according to an exemplary embodiment. [Figure 3] 1 is a graph showing the light absorption characteristics of a near-infrared blocking filter composition according to an exemplary embodiment. [Figure 4] 1 is a graph showing the light absorption characteristics of a near-infrared blocking filter composition according to an exemplary embodiment. [Figure 5]FIG. 1 is a plan view illustrating an image sensor according to an exemplary embodiment. [Figure 6] FIG. 6 is a cross-sectional view taken along line AA' in FIG. 5. [Figure 7] 1 is a cross-sectional view illustrating an image sensor according to an exemplary embodiment. [Figure 8] FIG. 1 is a plan view illustrating an image sensor according to an exemplary embodiment. [Figure 9] FIG. 9 is a cross-sectional view taken along line AA' in FIG. 8. [Figure 10] 1 is a cross-sectional view illustrating an image sensor according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Exemplary embodiments of the technical concept of the present invention will now be described in detail with reference to the accompanying drawings.

[0013] Exemplary embodiments include a near-infrared blocking filter composition employed in an image sensor, a near-infrared blocking filter manufactured using the near-infrared blocking filter composition, and an image sensor including a near-infrared blocking filter.

[0014] A near-infrared blocking filter composition according to an exemplary embodiment includes a mixture of a first cyanine dye, a second cyanine dye, and a tertiary cyanine dye.

[0015] In an exemplary embodiment, the first cyanine dye is represented by Formula 1: The following chemical formula 1

[0016] [ka] wherein R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms. R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group. R4 is at least one of an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, and a propoxyl group. X is a nonmetallic element. For example, X is at least one of a halogen atom, phosphate, hexafluorophosphate, perchlorate, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanide (TFSI), or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF).

[0017] In an exemplary embodiment, the second cyanine dye is represented by Formula 2: The following chemical formula 2

[0018] [ka] wherein R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms. R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group. R4 is at least one of an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, and a propoxyl group. X is a nonmetallic element. For example, X is at least one of a halogen atom, phosphate, hexafluorophosphate, perchlorate, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanide (TFSI), or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF).

[0019] In an exemplary embodiment, the tertiary cyanine dye is represented by Formula 3 or Formula 4: The following chemical formula 3

[0020] [ka] wherein R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms. R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group. R4 is at least one of an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, and a propoxyl group. X is a nonmetallic element. For example, X is at least one of a halogen atom, phosphate, hexafluorophosphate, perchlorate, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanide (TFSI), or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF). The following chemical formula 4

[0021] [ka] wherein R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms. R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group. X is a non-metallic element. For example, X is at least one of a halogen atom, phosphoric acid, hexafluorophosphate, perchloric acid, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanide (TFSI), or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF).

[0022] In an exemplary embodiment, the composition for a near-infrared blocking filter includes a binder solution, and a first cyanine dye, a second cyanine dye, and a third cyanine dye contained in the binder solution in predetermined ratios.

[0023] In exemplary embodiments, the binder solution includes a polysulfone polymer or a cycloolefin polymer in a chloroform or dichloromethane solvent. In some embodiments, the binder solution may also include at least one of polyarylene ether sulfone, polyether ether sulfone, polyether sulfone, polyimide, polyimidazole, polybenzimidazole, polyether benzimidazole, polyarylene ether ketone, polyether ether ketone, polyether ketone, polyether ketone ketone, and polystyrene.

[0024] In an exemplary embodiment, the first cyanine dye, the second cyanine dye, and the third cyanine dye are contained in the near-infrared blocking filter composition in a weight ratio of a:b:c, where a is 0.1 to 0.9, b is 0.2 to 1.0, and c is 0.6 to 1.4. In some embodiments, the first cyanine dye, the second cyanine dye, and the third cyanine dye are contained in the near-infrared blocking filter composition in a weight ratio of a:b:c, where a is 0.4 to 0.6, b is 0.5 to 0.7, and c is 0.9 to 1.1.

[0025] In an exemplary embodiment, the first cyanine dye, the second cyanine dye, and the third cyanine dye are contained in a binder solution in molar amounts of a1, b1, and c1, respectively, in a near-infrared blocking filter composition. For example, in 2 g of binder solution, the first cyanine dye is contained in a range of 0.0005 mmol to 0.0045 mmol (e.g., a1 is in a range of 0.0005 mmol to 0.0045 mmol), the second cyanine dye is contained in a range of 0.001 mmol to 0.005 mmol (e.g., b1 is in a range of 0.001 mmol to 0.005 mmol), and the third cyanine dye is contained in a range of 0.003 mmol to 0.007 mmol (e.g., c1 is in a range of 0.003 mmol to 0.007 mmol).

[0026] In an exemplary embodiment, the weight ratio of the first cyanine dye, the second cyanine dye, and the third cyanine dye contained in the near-infrared blocking filter composition is within a range that maximizes the transmittance of light in the visible light region while minimizing the transmittance of light in the near-infrared region.

[0027] In an exemplary embodiment, a near-infrared blocking filter manufactured using the near-infrared blocking filter composition may exhibit a first average transmittance for light in the 700 to 1100 nm range (e.g., near-infrared radiation), the first average transmittance being in the range of 0 to 30%. In some embodiments, the first average transmittance is in the range of 0 to 10%.

[0028] In exemplary embodiments, the near-infrared blocking filter can exhibit a second average transmittance for light in the 400-700 nm range (e.g., for visible light), the second average transmittance being in the range of 60-100%. In some embodiments, the second average transmittance is in the range of 80-100%.

[0029] In an exemplary embodiment, the first cyanine dye is configured to absorb light having a wavelength in the 750 to 850 nm range, and the maximum absorption wavelength of the first cyanine dye is 760 to 810 nm. In an exemplary embodiment, the second cyanine dye is configured to absorb light having a wavelength in the 850 to 950 nm range, and the maximum absorption wavelength of the second cyanine dye is 870 to 920 nm. In an exemplary embodiment, the third cyanine dye is configured to absorb light having a wavelength in the 950 to 1100 nm range, and the maximum absorption wavelength of the third cyanine dye is 1000 to 1100 nm. When the composition for a near-infrared blocking filter contains the first cyanine dye, the second cyanine dye, and the third cyanine dye in a weight ratio of a:b:c, a near-infrared blocking filter formed from the composition for a near-infrared blocking filter can have excellent near-infrared blocking properties (or absorption properties) as well as excellent visible light transmittance properties.

[0030] Hereinafter, a method for synthesizing a composition for a near-infrared blocking filter according to an exemplary embodiment will be described.

[0031] Method for synthesizing the first cyanine dye The first cyanine dye contained in the composition for a near-infrared blocking filter according to an exemplary embodiment is represented by Chemical Formula 1 below. The following chemical formula 1

[0032] [ka] wherein R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms. R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group. R4 is at least one of an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, and a propoxyl group. X is a nonmetallic element. For example, X is at least one of a halogen atom, phosphoric acid, hexafluorophosphate, perchloric acid, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanilide (TFSI), or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF). In some embodiments, X is bis(trifluoromethanesulfonyl)azanilide (TFSI), or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF).

[0033] In an exemplary embodiment, R1 and R2 in Chemical Formula 1 have a relatively long alkyl group having 6 to 12 carbon atoms, which allows the first cyanine dye to have excellent solubility in the binding solution. In an exemplary embodiment, R4 in Chemical Formula 1 includes a substituent having a property of imparting steric hindrance, which prevents the first cyanine dye molecules from aggregating when the first cyanine dye is dissolved in the binding solution. In an exemplary embodiment, X in Chemical Formula 1 -is a counter anion and a non-metallic ion. In some embodiments, X is a non-metallic ion with a large molecular weight, such as TFSI or BARF, which can improve the solubility and heat resistance of the first cyanine dye. In an exemplary embodiment, the first cyanine dye is configured to absorb light having a wavelength in the range of 750 to 850 nm, and the first cyanine dye has a maximum absorption wavelength of 760 to 810 nm.

[0034] The first cyanine dye represented by Chemical Formula 1 can be synthesized by the following synthesis method.

[0035] First, a 2,3,3-trimethylindolenine derivative can be synthesized. As shown in Step 1-1 below, 2,3,3-trimethylindolenine is added to an acetonitrile solution, and then alkyl iodide is added and reacted at 100°C for 12 hours to synthesize 1-hexyl-2,3,3-trimethyl-3H-indol-1-ium.

[0036] [Step 1-1]

[0037] [ka] Next, an anilinium salt can be synthesized. As shown in Step 1-2 below, dimethylformamide is added to phosphoryl chloride (POCl3) and reacted at 0°C for 30 minutes, and then refluxed in cyclohexanone for 30 minutes. Next, aniline and ethanol are added and reacted at room temperature for 1 hour to synthesize N-((E)-((E)-2-chloro-3-((phenylamino)methylene)cyclohex-1-en-1-yl)methylene)benzeneaminium.

[0038] [Steps 1-2]

[0039] [ka] Next, a heptamethine cyanine dye can be synthesized through a coupling reaction. As shown in Step 1-3 below, the 2,3,3-trimethylindolenine derivative (e.g., 1-hexyl-2,3,3-trimethyl-3H-indol-1-ium) formed in Step 1-1 and the anilinium salt (e.g., N-((E)-((E)-2-chloro-3-((phenylamino)methylene)cyclohex-1-en-1-yl)methylene)benzeneaminium) formed in Step 1-2 are added to sodium acetate and ethanol and refluxed for 12 hours to synthesize the heptamethine cyanine dye.

[0040] [Steps 1-3]

[0041] [ka] In an exemplary embodiment, the heptamethine cyanine dye synthesized through steps 1-1, 1-2, and 1-3 is 2-((E)-2-((E)-2-chloro-3-(2-((E)-1-hexyl-3,3-dimethylindolin-2-ylidene)ethylidene)cyclohex-1-en-1-yl)vinyl)-1-hexyl-3,3-dimethyl-3H-indol-1-ium.

[0042] Next, as shown in Step 1-4 below, the heptamethine cyanine dye synthesized in Step 1-3 is added to a solution of sodium hydride (NaH) and dimethylformamide (DMF), and phenol is added and reacted at room temperature to synthesize 1-hexyl-2-((E)-2-((E)-3-(2-((E)-1-hexyl-3,3-dimethylindolin-2-ylidene)ethylidene)-2-phenoxycyclohex-1-en-1-yl)vinyl)-3,3-dimethyl-3H-indol-1-ium.

[0043] [Steps 1-4]

[0044] [ka] Next, anion substitution is carried out. As shown in steps 1-5 below, the heptamethine cyanine dye synthesized in steps 1-4 is added to an acetone solution, and BARF anions are added to synthesize the first cyanine dye at room temperature.

[0045] [Steps 1-5]

[0046] [ka] Methods for synthesizing secondary cyanine dyes The second cyanine dye contained in the composition for a near-infrared blocking filter according to an exemplary embodiment is represented by Chemical Formula 2 below. The following chemical formula 2

[0047] [ka] wherein R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms. R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group. R4 is at least one of an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, and a propoxyl group. X is a nonmetallic element. For example, X is at least one of a halogen atom, phosphate, hexafluorophosphate, perchlorate, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanide (TFSI), or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF).

[0048] In an exemplary embodiment, R1 and R2 in Chemical Formula 2 have a relatively long alkyl group having 6 to 12 carbon atoms, which allows the second cyanine dye to have excellent solubility in the binding solution. In an exemplary embodiment, R4 in Chemical Formula 2 includes a substituent having a property of imparting steric hindrance, which prevents the second cyanine dye molecules from aggregating when the second cyanine dye is dissolved in the binding solution. In an exemplary embodiment, X in Chemical Formula 2 - is a counter anion and a non-metallic ion. In some embodiments, X is a non-metallic ion with a large molecular weight, such as TFSI or BARF, which can improve the solubility and heat resistance of the second cyanine dye. In an exemplary embodiment, the second cyanine dye is configured to absorb light having a wavelength in the range of 850 to 950 nm, and the second cyanine dye has a maximum absorption wavelength of 870 to 920 nm.

[0049] The second cyanine dye represented by Chemical Formula 2 can be synthesized by the following synthesis method.

[0050] First, a derivative of the commercial dye (IR-813) can be synthesized. As shown in Step 2-1 below, 1,1,3-trimethyl-2-((E)-2-((E)-2-(phenylsulfonyl)-3-((E)-2-(1,1,3-trimethyl-1,3-dihydro-2H-benzo[e]indol-2-ylidene)ethylidene)cyclohex-1-en-1-yl)vinyl)-1H-benzo[e]indol-3-ium indol-1-ium 4-methylbenzenesulfonate can be synthesized from the commercial dye IR-813 in a solution containing sodium cations and benzenesulfonate anions.

[0051] [Step 2-1]

[0052] [ka] Next, anion substitution is carried out. As shown in Step 2-2 below, the commercial dye derivative synthesized in Step 2-1 is added to an acetone solution, and BARF anions are added to synthesize the second cyanine dye at room temperature.

[0053] [Step 2-2]

[0054] [ka] Methods for synthesizing tertiary cyanine dyes The tertiary cyanine dye contained in the composition for a near-infrared blocking filter according to an exemplary embodiment is represented by Chemical Formula 3 below. The following chemical formula 3

[0055] [ka] wherein R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms. R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group. R4 is at least one of an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, and a propoxyl group. X is a nonmetallic element. For example, X is at least one of a halogen atom, phosphate, hexafluorophosphate, perchlorate, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanide (TFSI), or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF).

[0056] In an exemplary embodiment, R1 and R2 in Chemical Formula 3 have a relatively long alkyl group having 6 to 12 carbon atoms, which allows the tertiary cyanine dye to have excellent solubility in the binding solution. In an exemplary embodiment, R4 in Chemical Formula 3 includes a substituent that imparts steric hindrance, which prevents the tertiary cyanine dye molecules from aggregating when the tertiary cyanine dye is dissolved in the binding solution. In an exemplary embodiment, X in Chemical Formula 3 - is a counter anion and a non-metallic ion. In some embodiments, X is a non-metallic ion with a large molecular weight, such as TFSI or BARF, which can improve the solubility and heat resistance of the tertiary cyanine dye. In an exemplary embodiment, the tertiary cyanine dye is configured to absorb light having a wavelength in the range of 950 to 1100 nm, and the tertiary cyanine dye has a maximum absorption wavelength of 1000 to 1100 nm.

[0057] The tertiary cyanine dye represented by Chemical Formula 3 can be synthesized by the following synthesis method.

[0058] First, the benzo[c,d]indolium derivative can be synthesized. As shown in Step 3-1 below, benzo[c,d]indol-2(1H)-one is added to o-dichlorobenzene and the resulting mixture is treated with CH3(CH2)9I, 45% NaOH aqueous solution and 18-crown-6 material are added together to synthesize 1-decylbenzo[c,d]indol-2(1H)-one. Methylmagnesium iodide and ether are then added and the mixture is maintained at -5°C for a predetermined time, followed by a period at 35°C. 20% HClO4 aqueous solution is then added and the mixture is allowed to react at 0°C to synthesize 1-decyl-2-methylbenzo[c,d]indol-1-ium perchlorate.

[0059] [Step 3-1]

[0060] [ka] Next, an anilinium salt can be synthesized. As shown in Step 3-2 below, dimethylformamide is added to phosphoryl chloride (POCl3) and reacted at 0°C for 30 minutes, and then refluxed in cyclohexanone for 30 minutes. Next, aniline and ethanol are added and reacted at room temperature for 1 hour to synthesize N-((E)-((E)-2-chloro-3-((phenylamino)methylene)cyclohex-1-en-1-yl)methylene)benzeneaminium.

[0061] [Step 3-2]

[0062] [ka] A heptamethine cyanine dye can then be synthesized through a coupling reaction. As shown in Step 3-3 below, the benzo[c,d]indolium derivative formed in Step 3-1 and the anilinium salt formed in Step 3-2 are added to acetic anhydride and sodium acetate to synthesize the heptamethine cyanine dye. In an exemplary embodiment, the heptamethine cyanine dye synthesized through Steps 3-1, 3-2, and 3-3 is 2-((E)-2-((E)-2-chloro-3-((E)-2-(1-decylbenzo[cd]indol-2(1H)-ylidene)ethylidene)cyclohex-1-en-1-yl)vinyl)-1-decylbenzo[cd]indol-1-ium perchlorate.

[0063] [Step 3-3]

[0064] [ka] Next, anion substitution is carried out. As shown in Step 3-4 below, the heptamethine cyanine dye synthesized in Step 3-3 is added to NaBARF and a dichloromethane (DCM) / acetone solution and reacted at room temperature to synthesize the tertiary cyanine dye.

[0065] [Steps 3-4]

[0066] [ka] Methods for synthesizing quaternary cyanine dyes The tertiary cyanine dye contained in the composition for a near-infrared blocking filter according to an exemplary embodiment is represented by the following Chemical Formula 4. The following chemical formula 4

[0067] [ka] wherein R1 and R2 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms. R3 is at least one of a halogen atom, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group. X is a non-metallic element. For example, X is at least one of a halogen atom, phosphoric acid, hexafluorophosphate, perchloric acid, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanide (TFSI), or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF).

[0068] In an exemplary embodiment, R1 and R2 in Chemical Formula 4 have a relatively long alkyl group having 6 to 12 carbon atoms, which allows the tertiary cyanine dye to have good solubility in the binding solution. -is a counter anion and a non-metallic ion. In some embodiments, X is a non-metallic ion with a large molecular weight, such as TFSI or BARF, which can improve the solubility and heat resistance of the tertiary cyanine dye. In an exemplary embodiment, the tertiary cyanine dye is configured to absorb light having a wavelength in the range of 950 to 1100 nm, and the tertiary cyanine dye has a maximum absorption wavelength of 1000 to 1100 nm.

[0069] The tertiary cyanine dye represented by Chemical Formula 4 can be synthesized by the following synthesis method.

[0070] First, the benzo[c,d]indolium derivative can be synthesized. As shown in Step 3-1 below, benzo[c,d]indol-2(1H)-one is added to o-dichlorobenzene and the resulting mixture is treated with CH3(CH2)9I, 45% NaOH aqueous solution and 18-crown-6 material are added together to synthesize 1-decylbenzo[c,d]indol-2(1H)-one. Methylmagnesium iodide and ether are then added and the mixture is maintained at -5°C for a predetermined time, followed by a period at 35°C. 20% HClO4 aqueous solution is then added and the mixture is allowed to react at 0°C to synthesize 1-decyl-2-methylbenzo[c,d]indol-1-ium perchlorate.

[0071] [Step 4-1]

[0072] [ka] Next, an anilinium salt can be synthesized. As shown in Step 4-2 below, dimethylformamide is added to phosphoryl chloride (POCl3) and reacted at 0°C for 30 minutes, and then refluxed in cyclohexanone for 30 minutes. Next, aniline and ethanol are added and reacted at room temperature for 1 hour to synthesize N-((E)-((E)-2-chloro-3-((phenylamino)methylene)cyclopent-1-en-1-yl)methylene)benzeneaminium.

[0073] [Step 4-2]

[0074] [ka] The heptamethine cyanine dye can then be synthesized through a coupling reaction. As shown in Step 4-3 below, the benzo[c,d]indolium derivative formed in Step 4-1 and the anilinium salt formed in Step 4-2 are added to acetic anhydride and sodium acetate to synthesize the heptamethine cyanine dye. In an exemplary embodiment, the heptamethine cyanine dye synthesized through Steps 4-1, 4-2, and 4-3 is 2-((E)-2-((E)-2-chloro-3-((E)-2-(1-decylbenzo[cd]indol-2(1H)-ylidene)ethylidene)cyclopent-1-en-1-yl)vinyl)-1-decylbenzo[cd]indol-1-ium perchlorate.

[0075] [Step 4-3]

[0076] [ka] Next, anion substitution is carried out. As shown in Step 4-4 below, the heptamethine cyanine dye synthesized in Step 4-3 is added to NaBARF and a dichloromethane (DCM) / acetone solution and reacted at room temperature to synthesize the tertiary cyanine dye.

[0077] [Step 4-4]

[0078] [ka] FIG. 1 is a graph showing the light absorption characteristics of a near-infrared blocking filter composition according to an exemplary embodiment.

[0079] FIG. 1 shows the optical absorption data for the 350 nm to 1100 nm region of the near-infrared blocking filter according to Experimental Example 11 (EX11). To form the near-infrared blocking filter according to Experimental Example 11 (EX11), a first cyanine dye, a second cyanine dye, and a third cyanine dye were mixed in a ratio of 0.6:0.5:1, spin-coated onto a transparent substrate, and dried to obtain a near-infrared blocking filter in film form. The first cyanine dye included a heptamethine cyanine dye represented by Chemical Formula 1 obtained by the aforementioned synthesis method. The second cyanine dye included a heptamethine cyanine dye represented by Chemical Formula 2 obtained by the aforementioned synthesis method. The third cyanine dye included a heptamethine cyanine dye represented by Chemical Formula 4 obtained by the aforementioned synthesis method. The near-infrared blocking filter was formed to a thickness of approximately 1.5 micrometers.

[0080] 1, the near-infrared blocking filter of Experimental Example 11 (EX11) exhibited a transmittance of 60% or more and an average transmittance of 80% or more in the visible light region (I), for example, in the light region having a wavelength range of 700 nm or less. Furthermore, the near-infrared blocking filter of Experimental Example 11 (EX11) exhibited an average transmittance of 0 to 30% in the near-infrared region (II), for example, in the light region having a wavelength range of 700 nm to 1100 nm. In particular, the maximum transmittance did not exceed approximately 30% in the wavelength range of 750 nm to 1100 nm, and thus exhibited an average transmittance of 0 to 10% in the wavelength range of 750 nm to 1100 nm.

[0081] As shown in FIG. 1, the near-infrared blocking filter according to Experimental Example 11 (EX11) exhibits three peak values ​​having inflection points of transmittance in the near-infrared region (II), with the first peak 1a observed at a wavelength of about 780 nm, the second peak 2a observed at a wavelength of about 890 nm, and the third peak 3a observed at a wavelength of about 1070 nm.

[0082] For example, in the wavelength region of 750 nm to 850 nm, the near-infrared blocking filter of Experimental Example 11 (EX11) exhibits the lowest transmittance at a first peak 1a observed at a wavelength of approximately 780 nm. This transmittance peak is attributed to the first cyanine dye represented by Chemical Formula 1, and the first peak 1a corresponds to the maximum absorption wavelength of the first cyanine dye.

[0083] For example, in the region of 850 nm to 950 nm, the near-infrared blocking filter of Experimental Example 11 (EX11) exhibits the lowest transmittance at a second peak 2a observed at a wavelength of approximately 890 nm. This transmittance peak is caused by the second cyanine dye represented by Chemical Formula 2, and the second peak 2a corresponds to the maximum absorption wavelength of the second cyanine dye.

[0084] For example, in the region of 950 nm to 1100 nm, the near-infrared blocking filter of Experimental Example 11 (EX11) exhibits the lowest transmittance at a third peak 3a observed at a wavelength of approximately 1070 nm, which is a transmittance peak caused by the third cyanine dye represented by Chemical Formula 4, and the third peak 3a corresponds to the maximum absorption wavelength of the third cyanine dye.

[0085] 1, the near-infrared blocking filter according to Experimental Example 11 (EX11) transmits light in the visible light region with a relatively high transmittance, while transmitting light in the near-infrared region with a relatively low transmittance. In other words, it can be seen that the near-infrared blocking filter according to Experimental Example 11 (EX11) absorbs light in the near-infrared region at a relatively high rate.

[0086] 2 to 4 are graphs showing the light absorption characteristics of near-infrared blocking filter compositions according to exemplary embodiments.

[0087] 2 shows the optical absorption data in the 350 nm to 1100 nm region of the near-infrared blocking filter according to Experimental Example 21 (EX21). To form the near-infrared blocking filter according to Experimental Example 21 (EX21), only the first cyanine dye was added to a binder solution, which was spin-coated on a transparent substrate and dried to obtain a near-infrared blocking filter in film form. The first cyanine dye includes the heptamethine cyanine dye represented by Chemical Formula 1, which is obtained by the above-mentioned synthesis method.

[0088] As shown in Figure 2, the near-infrared blocking filter of Experimental Example 21 (EX21) exhibited a transmittance of 60% or more and an average transmittance of 80% or more in the visible light region (I), for example, in the light region having a wavelength range of 700 nm or less. Furthermore, the near-infrared blocking filter of Experimental Example 21 (EX21) exhibited an average transmittance of 0 to 30% in the region of 750 to 850 nm in the near-infrared region (II). In particular, the near-infrared blocking filter of Experimental Example 21 (EX21) has a maximum absorption wavelength MW1 at a wavelength of approximately 780 nm, i.e., it exhibits the lowest transmittance or highest absorbance value at a wavelength of approximately 780 nm.

[0089] 3 shows the optical absorption data in the 350 nm to 1100 nm region of the near-infrared blocking filter according to Experimental Example 22 (EX22). To form the near-infrared blocking filter according to Experimental Example 22 (EX22), only the second cyanine dye was added to a binder solution, which was spin-coated on a transparent substrate and dried to obtain a near-infrared blocking filter in film form. The second cyanine dye includes the heptamethine cyanine dye represented by Chemical Formula 2, which is obtained by the above-mentioned synthesis method.

[0090] As shown in Figure 3, the near-infrared blocking filter of Experimental Example 22 (EX22) exhibited a transmittance of 60% or more and an average transmittance of 80% or more in the visible light region (I), for example, in the light region having a wavelength range of 700 nm or less. Furthermore, the near-infrared blocking filter of Experimental Example 22 (EX22) exhibited an average transmittance of 0 to 30% in the 850 to 950 nm range in the near-infrared region (II). In particular, the near-infrared blocking filter of Experimental Example 22 (EX22) has a maximum absorption wavelength MW2 at a wavelength of approximately 890 nm, i.e., it exhibits the lowest transmittance or highest absorbance value at a wavelength of approximately 890 nm.

[0091] Referring to Figure 4, the optical absorption data in the 350 nm to 1100 nm region of the near-infrared blocking filters according to Experimental Examples 23 (EX23) and 24 (EX24) are shown. To form the near-infrared blocking filters according to Experimental Examples 23 (EX23) and 24 (EX), only the tertiary cyanine dye was added to a binder solution, which was spin-coated onto a transparent substrate and dried to obtain a near-infrared blocking filter in film form. The tertiary cyanine dye contained in Experimental Example 23 (EX23) was a heptamethine cyanine dye represented by Chemical Formula 3, obtained by the aforementioned synthesis method. The tertiary cyanine dye contained in Experimental Example 24 (EX24) was a heptamethine cyanine dye represented by Chemical Formula 4, obtained by the aforementioned synthesis method.

[0092] As shown in FIG. 4, the near-infrared blocking filters of Experimental Examples 23 (EX23) and 24 (EX24) exhibited transmittance of 60% or more and average transmittance of 80% or more in the visible light region (I), for example, in the light region having a wavelength range of 700 nm or less. Furthermore, the near-infrared blocking filters of Experimental Examples 23 (EX23) and 24 (EX24) exhibited average transmittance of 0 to 30% in the near-infrared region (II) from 950 nm to 1100 nm. In particular, the near-infrared blocking filter of Experimental Example 23 (EX23) has a maximum absorption wavelength MW3 at a wavelength of approximately 1040 nm, i.e., exhibits the lowest transmittance or highest absorbance value at a wavelength of approximately 1040 nm. Furthermore, the near-infrared blocking filter of Experimental Example 24 (EX24) has a maximum absorption wavelength MW4 at a wavelength of approximately 1070 nm, i.e., exhibits the lowest transmittance or highest absorbance value at a wavelength of approximately 1070 nm.

[0093] FIG. 5 is a plan view showing an image sensor 100 according to an exemplary embodiment, and FIG. 6 is a cross-sectional view taken along line AA' in FIG.

[0094] 5 and 6, the image sensor 100 includes a plurality of pixels PX arranged in a matrix. The image sensor 100 includes a plurality of photoelectric conversion regions PD formed in a semiconductor substrate 110. A pixel separating structure 120 is disposed on the semiconductor substrate 110, extending from a first surface 110F1 to a second surface 110F2 and defining the plurality of pixels PX. At least one photoelectric conversion region PD is disposed within each pixel PX defined by the pixel separating structure 120.

[0095] A transfer gate TG may be disposed on the first surface 110F1 of the semiconductor substrate 110. The transfer gate TG is disposed within the trench TGH to extend into the semiconductor substrate 110 and is configured to control photoelectrons stored in the photoelectric conversion region PD. A pixel transistor may be further formed on the front surface of the semiconductor substrate 110 and configured to transfer photoelectrons stored in the photoelectric conversion region PD to the flow diffusion region or reset the photoelectrons stored in the photoelectric conversion region PD. A front wiring layer FL and a front insulating layer FIL are disposed on the first surface 110F1 of the semiconductor substrate 110 to cover the transfer gate TG and the pixel transistor.

[0096] An anti-reflection film 130 may be disposed on the second surface 110F2 of the semiconductor substrate 110. A grid GR may be disposed on the anti-reflection film 130, dividing pixel spaces corresponding to the pixels PX. Color filters CF may be disposed on the anti-reflection film 130 within the pixel spaces defined by the grid GR. The color filters CF may sense green, blue, and red light depending on the type of material contained in the color filters CF. For example, the plurality of pixels PX may include a green pixel G, a blue pixel B, and a red pixel R, where the green pixel G includes a color filter CF that senses green, the blue pixel B includes a color filter CF that senses blue, and the red pixel R includes a color filter CF that senses red. In an exemplary embodiment, as shown in FIG. 5, the green pixels G, blue pixels B, and red pixels R are arranged in a Bayer pattern. In other embodiments, the arrangement of the green pixels G, blue pixels B, and red pixels R may be variously changed.

[0097] A near-infrared blocking filter IF may be disposed on the color filter CF. In an exemplary embodiment, the near-infrared blocking filter IF is formed from the near-infrared blocking filter composition according to the above exemplary embodiment, and the near-infrared blocking filter composition includes a first cyanine dye, a second cyanine dye, and a third cyanine dye.

[0098] In an exemplary embodiment, the first cyanine dye is a heptamethine cyanine dye represented by Chemical Formula 1 above, and the first cyanine dye is configured to absorb light having a wavelength in the range of 750 to 850 nm, and the maximum absorption wavelength of the first cyanine dye is 760 to 810 nm.

[0099] In an exemplary embodiment, the second cyanine dye is a heptamethine cyanine dye represented by Chemical Formula 2 above, and the second cyanine dye is configured to absorb light having a wavelength in the range of 850 to 950 nm, and the maximum absorption wavelength of the second cyanine dye is 870 to 920 nm.

[0100] In an exemplary embodiment, the third cyanine dye is a heptamethine cyanine dye represented by the aforementioned Chemical Formula 3 or a heptamethine cyanine dye represented by the aforementioned Chemical Formula 4, and the third cyanine dye is configured to absorb light having a wavelength in the range of 950 to 1100 nm, and the maximum absorption wavelength of the third cyanine dye is 1000 to 1100 nm.

[0101] In an exemplary embodiment, a near-infrared blocking filter IF is formed by spin-coating a near-infrared blocking filter composition according to the aforementioned exemplary embodiment onto a color filter CF. For example, the near-infrared blocking filter IF includes a first cyanine dye, a second cyanine dye, and a third cyanine dye in a weight ratio of a:b:c, where a is 0.1 to 0.9, b is 0.2 to 1.0, and c is 0.6 to 1.4. In some embodiments, a is 0.4 to 0.6, b is 0.5 to 0.7, and c is 0.9 to 1.1.

[0102] In an exemplary embodiment, the near-infrared blocking filter IF has a first average transmittance for light in the 700 to 1100 nm range, and the first average transmittance is 0 to 30%. In some embodiments, the first average transmittance is 0 to 10%. In an exemplary embodiment, the near-infrared blocking filter IF has a second average transmittance for light in the 400 to 700 nm range, and the second average transmittance is 60 to 100%. In some embodiments, the second average transmittance is 80 to 100%.

[0103] In an exemplary embodiment, the near-infrared blocking filter IF may have a first thickness t1, which may be in the range of 50 nm to 1000 nm.

[0104] In an exemplary embodiment, a microlens ML may be disposed on the near-infrared blocking filter IF. No anti-reflection layer made of an inorganic material is interposed between the near-infrared blocking filter IF and the microlens ML or between the near-infrared blocking filter IF and the color filter CF. In some embodiments, the near-infrared blocking filter IF may be in direct contact with the microlens ML disposed thereon. In other embodiments, a thin passivation layer may be interposed between the near-infrared blocking filter IF and the microlens ML disposed thereon. In some embodiments, the near-infrared blocking filter IF may be in direct contact with the color filter CF disposed thereunder. In other embodiments, a thin passivation layer may be interposed between the near-infrared blocking filter IF and the color filter CF disposed thereunder.

[0105] Generally, when near-infrared or infrared rays are transmitted through a silicon substrate, distortion of the red image occurs. Therefore, a method of absorbing infrared or near-infrared rays by disposing a near-infrared blocking filter below a module lens has been proposed. Such near-infrared blocking filters include a filter layer containing a dye coated on the upper surface of a transparent substrate and an anti-reflection stack made of an inorganic material coated on the lower surface of the transparent substrate, and have a relatively large thickness. The relatively large size of such near-infrared blocking filters restricts miniaturization of image sensors. In addition, the deviation in blocking characteristics depending on the angle of incidence is relatively large, resulting in problems such as noise generation due to light leakage.

[0106] According to an exemplary embodiment, the near-infrared blocking filter IF may exhibit relatively high near-infrared absorbance (relatively uniform near-infrared absorbance) over the entire wavelength range of 700 to 1100 nm. Furthermore, the near-infrared blocking filter IF is coated on the rear surface of the image sensor 100 using a wafer-level scheme, eliminating the need for a separate anti-reflection stack. Therefore, the image sensor 100 may have excellent near-infrared blocking properties while being compact in size.

[0107] FIG. 7 is a cross-sectional view illustrating an image sensor 100A according to an example embodiment.

[0108] 7, an anti-reflection film 130 is disposed on a second surface 110F2 of the semiconductor substrate 110, and a grid GR that separates pixel spaces corresponding to the pixels PX is disposed on the anti-reflection film 130. A near-infrared blocking filter IF may be disposed within the pixel space defined by the grid GR on the anti-reflection film 130. A color filter CF may be disposed on the near-infrared blocking filter IF.

[0109] In an exemplary embodiment, the near-infrared blocking filter IF is formed from a near-infrared blocking filter composition according to the aforementioned exemplary embodiment. After forming a grid GR on the anti-reflection film 130, the near-infrared blocking filter composition is spin-coated within the pixel spaces defined by the grid GR, and then dried to form the near-infrared blocking filter IF.

[0110] In some exemplary embodiments, the microlens ML may further include a near-infrared blocking filter composition according to an exemplary embodiment, for example, a near-infrared blocking filter composition including a first cyanine dye, a second cyanine dye, and a third cyanine dye. For example, the microlens ML may include a light-transmitting organic material, and the near-infrared blocking filter composition may be further included in the light-transmitting organic material. This allows the microlens ML to have near-infrared blocking properties.

[0111] In some exemplary embodiments, the microlens ML including the near-infrared blocking filter composition may be provided together with the near-infrared blocking filter IF described with reference to Figures 5 to 7. In some exemplary embodiments, the microlens ML including the near-infrared blocking filter composition may be provided in place of the near-infrared blocking filter IF described with reference to Figures 5 to 7.

[0112] FIG. 8 is a plan view showing an image sensor 200 according to an example embodiment, and FIG. 9 is a cross-sectional view taken along line AA' in FIG.

[0113] 8 and 9, the image sensor 200 includes a plurality of pixels PX, which include a green pixel G, a blue pixel B, a red pixel R, and an infrared pixel I. In an exemplary embodiment, the infrared pixel I is a pixel that senses infrared light and includes a color filter CF that senses infrared light.

[0114] In an exemplary embodiment, a near-infrared blocking filter IF is provided on the green pixel G, the blue pixel B, and the red pixel R, but not on the infrared pixel I. For example, a near-infrared blocking filter IF is disposed on the color filter CF corresponding to the green pixel G, on the color filter CF corresponding to the blue pixel B, and on the color filter CF corresponding to the red pixel R. A near-infrared blocking filter IF is not disposed on the color filter CF corresponding to the infrared pixel I.

[0115] In an exemplary embodiment, the near-infrared blocking filter IF includes a near-infrared blocking filter composition contained in a photosensitive material. For example, the near-infrared blocking filter IF includes a near-infrared blocking filter composition contained in a photoresist material, such as a near-infrared blocking filter composition including a first cyanine dye, a second cyanine dye, and a third cyanine dye contained in the photoresist material. By including the near-infrared blocking filter composition contained in the photoresist material, the near-infrared blocking filter IF can be patterned by a lithography process, for example, by a photosensitive solution coating process, an exposure process, and a development process.

[0116] In an exemplary embodiment, the near-infrared blocking filter IF is formed using a near-infrared blocking filter composition contained in a photosensitive material, and by a lithography process, the near-infrared blocking filter IF is formed on the color filters CF corresponding to the green pixel G, the blue pixel B, and the red pixel R, but is not formed on the color filter CF corresponding to the infrared pixel I. In an exemplary embodiment, as shown in FIG. 9 , the near-infrared blocking filter IF is disposed on the color filters CF, and a microlens ML may be disposed on the near-infrared blocking filter IF.

[0117] FIG. 10 is a cross-sectional view illustrating an image sensor 200A according to an example embodiment.

[0118] 10 , the plurality of pixels PX include a green pixel G, a blue pixel B, a red pixel R, and an infrared pixel I. A near-infrared blocking filter IF is provided on the green pixel G, the blue pixel B, and the red pixel R, but is not provided on the infrared pixel I. For example, the near-infrared blocking filter IF is disposed below the color filter CF corresponding to the green pixel G, below the color filter CF corresponding to the blue pixel B, and below the color filter CF corresponding to the red pixel R. The near-infrared blocking filter IF is not disposed below the color filter CF corresponding to the infrared pixel I. In an exemplary embodiment, the near-infrared blocking filter IF may be disposed on the second surface 110F2 of the semiconductor substrate 110 (e.g., on the anti-reflection film 130) within a pixel space defined by the grid GR, and the color filter CF may be disposed on the near-infrared blocking filter IF.

[0119] According to the technical concept of the present invention, a near-infrared blocking filter includes a mixture of a first cyanine dye, a second cyanine dye, and a third cyanine dye, and the mixture of the first cyanine dye, the second cyanine dye, and the third cyanine dye exhibits a transmittance of 0 to 30% for near-infrared rays in the range of 700 to 1100 nm. The near-infrared blocking filter is coated on the rear surface of an image sensor using a wafer-level scheme, thereby enabling the image sensor to have a compact size while exhibiting excellent near-infrared blocking properties.

[0120] As mentioned above, exemplary embodiments have been disclosed in the drawings and specification. Although specific terms have been used to describe the embodiments in this specification, they are used solely for the purpose of explaining the technical idea of ​​the present invention and are not used to limit the meaning or the scope of the present invention as described in the claims. Therefore, a person skilled in the art will understand that various modifications and equivalent embodiments are possible. Therefore, the true technical scope of protection of the present invention should be determined by the technical idea of ​​the claims. [Explanation of symbols]

[0121] 100 image sensors 110 Semiconductor substrate 120 pixel isolation structure 130 Anti-reflection coating 110F1 1st page 110F2 2nd side CF color filter FL front wiring layer FIL front insulation layer GR Grid IF near-infrared blocking filter ML Micro Lens PD photoelectric conversion region TGH Trench TG Transmission Gate

Claims

1. A composition for a near-infrared blocking filter used in an image sensor, comprising: comprising a mixture of a first cyanine dye, a second cyanine dye, and a tertiary cyanine dye; The first cyanine dye is represented by the following Chemical Formula 1: The second cyanine dye is represented by the following Chemical Formula 2: The tertiary cyanine dye is represented by the following Chemical Formula 3 or 4: 【Chemical 1】 In Chemical Formula 1, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms; R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R ４ represents an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group, and X represents a nonmetallic element; 【Chemistry 2】 In Chemical Formula 2, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms, R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R ４ represents an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group, and X represents a nonmetallic element; 【Chemistry 3】 In Chemical Formula 3, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms, R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R ４ represents an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group, and X represents a nonmetallic element; 【Chemistry 4】 In Chemical Formula 4, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms, R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group, and X is a non-metallic element; A composition for a near-infrared blocking filter.

2. the composition for a near-infrared blocking filter contains the first cyanine dye, the second cyanine dye, and the third cyanine dye in a weight ratio of a:b:c; a is 0.1 to 0.9; b is 0.2 to 1.0, 2. The near-infrared blocking filter composition according to claim 1, wherein c is 0.6 to 1.

4.

3. the composition for a near-infrared blocking filter contains the first cyanine dye, the second cyanine dye, and the third cyanine dye in a weight ratio of a:b:c; a is 0.4 to 0.6; b is 0.5 to 0.7; 2. The near-infrared blocking filter composition according to claim 1, wherein c is 0.9 to 1.

1.

4. the first cyanine dye is configured to absorb light having a wavelength in the range of 750 to 850 nm; the second cyanine dye is configured to absorb light having a wavelength in the range of 850 to 950 nm; 2. The near-infrared blocking filter composition of claim 1, wherein the tertiary cyanine dye is configured to absorb light having a wavelength in the range of 950 to 1100 nm.

5. the first cyanine dye has a maximum absorption wavelength of 760 to 810 nm; the second cyanine dye has a maximum absorption wavelength of 870 to 920 nm; 5. The near-infrared blocking filter composition according to claim 4, wherein the tertiary cyanine dye has a maximum absorption wavelength of 1000 to 1100 nm.

6. a substrate including a first surface and a second surface opposite the first surface, the substrate including a plurality of pixels, each of the plurality of pixels including a photoelectric conversion region; a near-infrared blocking filter disposed on the second surface of the substrate; the near-infrared blocking filter comprises a mixture of a first cyanine dye, a second cyanine dye, and a third cyanine dye; The first cyanine dye is represented by the following Chemical Formula 1: The second cyanine dye is represented by the following Chemical Formula 2: The tertiary cyanine dye is represented by the following formula 3 or 4: The following chemical formula 1 【Chemistry 5】 In this case, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms; R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R ４ represents an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group, and X represents a nonmetallic element; The following chemical formula 2 【Chemistry 6】 In this case, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms, R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R ４ represents an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group, and X represents a nonmetallic element; The following chemical formula 3 【Chemistry 7】 In this case, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms, R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R ４ represents an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group, and X represents a nonmetallic element; The following chemical formula 4 【Chemistry 8】 In this case, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms, R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group, and X is a non-metallic element; Image sensor.

7. In Formula 1, X is at least one of a halogen element, phosphoric acid, hexafluorophosphate, perchloric acid, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanilide (TFSI), and tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF); In Formula 2, X is at least one of a halogen element, phosphoric acid, hexafluorophosphate, perchloric acid, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanilide (TFSI), and tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF); In Formula 3, X is at least one of a halogen element, phosphoric acid, hexafluorophosphate, perchloric acid, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanilide (TFSI), and tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF); 7. The image sensor of claim 6, wherein in Chemical Formula 4, X is at least one of a halogen element, phosphoric acid, hexafluorophosphate, perchloric acid, tetrafluoroborate, p-toluenesulfonate, bis(trifluoromethanesulfonyl)azanilide (TFSI), and tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF).

8. the near-infrared blocking filter comprises the first cyanine dye, the second cyanine dye, and the third cyanine dye in a weight ratio of a:b:c; a is 0.1 to 0.9; b is 0.2 to 1.0, 7. The image sensor according to claim 6, wherein c is 0.6 to 1.

4.

9. the near-infrared blocking filter comprises the first cyanine dye, the second cyanine dye, and the third cyanine dye in a weight ratio of a:b:c; a is 0.4 to 0.6; b is 0.5 to 0.7; 7. The image sensor according to claim 6, wherein c is 0.9 to 1.

1.

10. the first cyanine dye is configured to absorb light having a wavelength in the range of 750 to 850 nm; the second cyanine dye is configured to absorb light having a wavelength in the range of 850 to 950 nm; 7. The image sensor of claim 6, wherein the tertiary cyanine dye is configured to absorb light having a wavelength in the range of 950 to 1100 nm.

11. the first cyanine dye has a maximum absorption wavelength of 760 to 810 nm; the second cyanine dye has a maximum absorption wavelength of 870 to 920 nm; 11. The image sensor according to claim 10, wherein the tertiary cyanine dye has a maximum absorption wavelength of 1000 to 1100 nm.

12. the near-infrared blocking filter has a first average transmittance for light in the range of 700 to 1100 nm; 7. The image sensor of claim 6, wherein the first average transmittance is 0 to 30%.

13. the near-infrared blocking filter has a second average transmittance for light in the range of 400 to 700 nm; 7. The image sensor of claim 6, wherein the second average transmittance is 60 to 100%.

14. a color filter disposed on the second surface of the substrate and the near-infrared blocking filter; The image sensor of claim 6 , further comprising: a microlens disposed on the near-infrared blocking filter.

15. a color filter disposed on the near-infrared blocking filter; The image sensor of claim 6 , further comprising: a microlens disposed on the color filter.

16. the plurality of pixels includes red pixels, green pixels, and blue pixels; 7. The image sensor of claim 6, wherein the near-infrared blocking filters are provided on the red pixels, the green pixels, and the blue pixels.

17. the plurality of pixels including a red pixel, a green pixel, a blue pixel, and an infrared pixel; the near-infrared blocking filters are provided on the red pixels, the green pixels, and the blue pixels; The image sensor of claim 6 , wherein the near-infrared blocking filter is not provided on the infrared pixels.

18. a substrate including a first surface and a second surface opposite the first surface, the substrate including a plurality of pixels, each of the plurality of pixels including a photoelectric conversion region; an anti-reflective layer disposed on the second surface of the substrate; a color filter disposed on the anti-reflection layer; a near-infrared blocking filter disposed on the color filter; a microlens disposed on the near-infrared blocking filter; the near-infrared blocking filter comprises a mixture of a first cyanine dye, a second cyanine dye, and a third cyanine dye, the near-infrared blocking filter comprising the first cyanine dye, the second cyanine dye, and the third cyanine dye in a weight ratio of a:b:c, wherein a is 0.4 to 0.6, b is 0.5 to 0.7, and c is 0.9 to 1.1; the first cyanine dye is a heptamethine cyanine dye and is configured to absorb light having a wavelength in the range of 750 to 850 nm, and the maximum absorption wavelength of the first cyanine dye is 760 to 810 nm; the second cyanine dye is a heptamethine cyanine dye and is configured to absorb light having a wavelength in the range of 850 to 950 nm, and the second cyanine dye has a maximum absorption wavelength of 870 to 920 nm; The third cyanine dye is a heptamethine cyanine dye and is configured to absorb light having a wavelength in the range of 950 to 1100 nm, and the third cyanine dye has a maximum absorption wavelength of 1000 to 1100 nm.

19. The first cyanine dye is represented by the following Chemical Formula 1: The second cyanine dye is represented by the following Chemical Formula 2: The following chemical formula 1 【Chemistry 9】 In this case, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms; R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R ４ represents an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group, and X represents a nonmetallic element; The following chemical formula 2 【Chemistry 10】 In this case, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms, R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R ４ represents an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group, and X represents a non-metallic element; 20. The image sensor of claim 18.

20. The tertiary cyanine dye is represented by the following Chemical Formula 3 or 4: The following chemical formula 3 【Chemistry 11】 In this case, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms, R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group; R ４ represents an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a phenyl group, a benzyl group, a tert-butylphenyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a cycloheptyl group, a cyclooctyl group, a methoxyl group, an ethoxyl group, or a propoxyl group, and X represents a nonmetallic element; The following chemical formula 4 【Chemistry 12】 In this case, R １ and R ２ are each independently a linear or branched alkyl group having 6 to 12 carbon atoms, R ３ is at least one of a halogen element, a phenol group, a p-hydroxybenzoic acid group, a methylparaben group, a methyl p-aminobenzoate group, a p-aminobenzoic acid group, an aniline group, a benzenesulfinic acid group, and a diphenylamine group, and X is a non-metallic element; 20. The image sensor of claim 19.

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