Optical filter, image sensor, camera module, and electronic device

Abstract

To provide an optical filter, an image sensor, a camera module, and an electronic device, in which the transmissivity of light in a visible light region is increased and the transmissivity of light in a near-infrared region is decreased with the small thickness.SOLUTION: An optical filter according to the present invention includes a near-infrared light absorption layer including a first material that absorbs light in a first wavelength region that belongs to a near-infrared ray wavelength region, a compensation layer disposed adjacent to the near-infrared light absorption layer and including a second material different from the first material, and a meta-material structure that exists apart from the near-infrared light absorption layer through the compensation layer and absorbs or reflects light in a second wavelength region that overlaps with the first wavelength region.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an optical filter, an image sensor, a camera module, and an electronic device. [Background technology]

[0002] 2. Description of the Related Art In recent years, electronic devices such as digital cameras, camcorders, and mobile phones with built-in cameras, each of which includes an image pickup device that stores an image as an electrical signal, have come into widespread use.

[0003] Such electronic devices include optical filters to reduce optical distortion caused by light outside the visible light range or to improve visibility of light outside the visible light range. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-092164 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above-mentioned conventional technology, and an object of the present invention is to provide an optical filter that has a small thickness and can achieve predetermined optical characteristics for light outside the visible light range. Another object of the present invention is to provide an image sensor including the optical filter, and a camera module including the optical filter or the image sensor. Furthermore, the present invention has an object to provide an electronic device including the optical filter, the image sensor, or the camera module. [Means for solving the problem]

[0006] In order to achieve the above object, an optical filter according to one embodiment of the present invention includes a near-infrared absorption layer including a first material that absorbs light in a first wavelength region belonging to a near-infrared wavelength region, a compensation layer disposed adjacent to the near-infrared absorption layer and including a second material different from the first material, and a metamaterial structure disposed away from the near-infrared absorption layer via the compensation layer and absorbing or reflecting light in a second wavelength region overlapping with the first wavelength region.

[0007] The metamaterial structure is not in direct contact with the near infrared light absorption layer. The compensation layer may be disposed underneath, on top of, or to the side of the near infrared light absorption layer, and the meta-material structure may be embedded within the compensation layer. The compensation layer may surround the meta-material structure. The metamaterial structure, surrounded by the compensation layer, may be embedded within the near infrared light absorption layer. It is preferable that the second substance does not substantially absorb light in the first wavelength region. The second substance may have a maximum extinction coefficient (k) of less than about 0.01 in a wavelength range of about 700 nm to 1200 nm. The second material may have an average refractive index (n) of about 1.4 to 2.6 in a wavelength range of about 700 nm to 1200 nm. The second material may include an oxide, a nitride, an oxynitride, a halide, a sulfide, a chalcogenide, a semiconductor element, a semiconductor compound, an organic material, or a combination thereof. The compensation layer may have a thickness between about 1.2 and 20 times the thickness of the metamaterial structure. The thickness ratio of the compensation layer to the near infrared absorbing layer may be about 1:4 to 1:50. The transmission spectrum of the first material has a first minimum transmission wavelength belonging to the first wavelength region, and the transmission spectrum of the metamaterial structure has a second minimum transmission wavelength belonging to the second wavelength region, and the first minimum transmission wavelength and the second minimum transmission wavelength may each be within a range of approximately 700 nm to 990 nm. The difference between the first minimum transmission wavelength and the second minimum transmission wavelength may be about 100 nm or less. The ratio of the average transmittance of the optical filter in the near infrared wavelength region to the average transmittance of the optical filter in the visible wavelength region may be about 0.07 or less. The optical filter may have an average transmittance of greater than about 80% in a wavelength range of about 430 nm to 565 nm, and an average transmittance of less than about 10% in a wavelength range of about 700 nm to 800 nm or about 890 nm to 990 nm.

[0008] In order to achieve the above object, a camera module according to one aspect of the present invention includes the optical filter described above.

[0009] In order to achieve the above object, an image sensor according to one aspect of the present invention includes a semiconductor substrate including a plurality of photodiodes, and the optical filter located on the semiconductor substrate.

[0010] The image sensor may further include a color filter located below or above the optical filter.

[0011] In order to achieve the above object, a camera module according to one aspect of the present invention includes the image sensor described above.

[0012] In order to achieve the above object, an electronic device according to one aspect of the present invention includes the camera module described above. Effect of the Invention

[0013] According to the present invention, it is possible to provide an optical filter, an image sensor, a camera module, and an electronic device that can effectively increase the transmittance of light in the visible light region and effectively decrease the transmittance of light in the near-infrared region with a thin thickness. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic diagram illustrating an example of an optical filter according to an embodiment of the present invention. [Diagram 2] 2 is an enlarged cross-sectional view showing a portion A of the optical filter in FIG. 1. [Diagram 3] FIG. 4 is a schematic diagram showing another example of an optical filter according to an embodiment of the present invention. [Figure 4] 4 is an enlarged cross-sectional view showing a portion A of the optical filter in FIG. 3. [Diagram 5] FIG. 13 is a schematic diagram showing yet another example of an optical filter according to an embodiment of the present invention. [Figure 6] 6 is an enlarged cross-sectional view showing a portion A of the optical filter in FIG. 5. [Figure 7] FIG. 7 is a schematic diagram showing the metamaterial structure of the optical filter of FIG. 6 capped by a compensation layer. [Figure 8] FIG. 2 is a schematic diagram illustrating an example of a camera module according to an embodiment of the present invention. [Figure 9] FIG. 2 is a schematic diagram illustrating another example of a camera module according to an embodiment of the present invention. [Figure 10] 1 is a cross-sectional view showing an example of an optical filter integrated image sensor according to an embodiment of the present invention. [Figure 11] 11 is a cross-sectional view showing another example of an optical filter integrated image sensor according to an embodiment of the present invention. [Figure 12] 11 is a cross-sectional view showing yet another example of an optical filter integrated image sensor according to an embodiment of the present invention. [Figure 13] 11 is a cross-sectional view showing another example of an optical filter integrated image sensor according to an embodiment of the present invention. FIG. [Figure 14] 1 is a schematic diagram of an electronic device according to one embodiment of the present invention. [Figure 15] 1 is a graph showing the transmission spectra of optical filters according to Example 1, Comparative Example 1, and Reference Example 1. [Figure 16] 1 is a graph showing the transmission spectra of optical filters according to Example 2, Comparative Example 1, and Reference Example 1. [Figure 17] 1 is a graph showing the transmission spectra of the optical filters according to Example 11 and Reference Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present invention will be described in detail below so that those skilled in the art can easily implement the present invention, however, the actual structures may be embodied in various different forms and are not limited to the embodiments described herein.

[0016] The drawings are exaggerated in thickness to clearly depict the various layers and regions. Similar elements are given the same reference numerals throughout the specification. When a layer, film, region, plate, or other part is said to be "on" another part, this includes not only when it is "directly on" the other part, but also when there is another part between them. Conversely, when a part is said to be "directly on" another part, it means that there is no other part between them.

[0017] Hereinafter, an optical filter according to an embodiment of the present invention will be described with reference to the drawings.

[0018] The optical filter 100 according to one embodiment of the present invention includes a film or thin film for filtering or blocking light in a predetermined wavelength range, for example, a film or thin film for filtering or blocking at least a portion of light in a wavelength range other than visible light, for example, a film or thin film for filtering or blocking at least a portion of light in the near-infrared wavelength range.

[0019] FIG. 1 is a schematic diagram showing an example of an optical filter according to one embodiment of the present invention, FIG. 2 is a cross-sectional view showing an enlarged view of portion A of the optical filter of FIG. 1, FIG. 3 is a schematic diagram showing another example of an optical filter according to one embodiment of the present invention, FIG. 4 is a cross-sectional view showing an enlarged view of portion A of the optical filter of FIG. 3, FIG. 5 is a schematic diagram showing yet another example of an optical filter according to one embodiment of the present invention, FIG. 6 is a cross-sectional view showing an enlarged view of portion A of the optical filter of FIG. 5, and FIG. 7 is a schematic diagram showing a metamaterial structure capped by a compensation layer in the optical filter of FIG. 6.

[0020] An optical filter 100 according to one embodiment of the present invention includes a near-infrared absorbing layer 101 , a meta-material structure 102 a , a compensation layer 103 , and a substrate layer 104 .

[0021] The near-infrared light absorption layer 101 includes a first substance that absorbs light in at least a part of the near-infrared wavelength region. The first substance mainly absorbs light in a predetermined wavelength region (hereinafter referred to as the "first wavelength region") belonging to the near-infrared wavelength region, and the first wavelength region belongs to a wavelength region of, for example, about 700 nm to 1200 nm. As an example, the first substance is a near-infrared absorbing substance that selectively absorbs light in the first wavelength region belonging to the near-infrared wavelength region and transmits light in the visible light wavelength region.

[0022] The transmission spectrum of the first material is determined by absorbing light in a first wavelength region and includes a first minimum transmission wavelength (λ min , T1 ) and has a first minimum transmission wavelength (λ min , T1) belongs to, for example, about 700 nm to 1100 nm, about 700 nm to 1000 nm, about 700 nm to 990 nm, about 700 nm to 900 nm, about 700 nm to 800 nm, about 750 nm to 1100 nm, about 750 nm to 1000 nm, about 750 nm to 990 nm, about 750 nm to 900 nm, about 750 nm to 800 nm, about 800 nm to 1100 nm, about 800 nm to 1000 nm, about 800 nm to 990 nm, about 800 nm to 900 nm, about 850 nm to 1100 nm, about 850 nm to 1000 nm, about 850 nm to 990 nm, about 850 nm to 900 nm, about 870 nm to 990 nm, or about 890 nm to 990 nm.

[0023] The first substance may be one or more, for example, an organic substance, an inorganic substance, an organic-inorganic substance, or a combination thereof. The first substance may be, for example, a quantum dot, a quinoid metal complex, a polymethine compound, a cyanine compound, a phthalocyanine compound, a merocyanine compound, a naphthalocyanine compound, an immonium compound, a diimmonium compound, a triarylmethane compound, a dipyrromethene compound, an anthraquinone compound, a diquinone compound, a diphenyl ether compound, a ... The compounds include, but are not limited to, quinone compounds, naphthoquinone compounds, squarylium compounds, rylene compounds, perylene compounds, pyrylium compounds, squaraine compounds, thiopyrylium compounds, diketopyrrolopyrrole compounds, boron-dipyrromethene compounds, nickel-dithiol complexes, croconium compounds, derivatives thereof, or combinations thereof.

[0024] The (average) refractive index of the near-infrared light absorption layer 101 containing the first substance in the visible light wavelength region and the near-infrared light wavelength region (e.g., about 400 nm to 1000 nm) is about 2.0 or less, or about 1.8 or less, for example, about 1.1 to 2.0 or about 1.1 to 1.8. For example, the (average) refractive index of the near-infrared light absorption layer 101 containing the first substance in the wavelength region of about 900 nm to 1000 nm (e.g., 940 nm) is about 2.0 or less, or about 1.8 or less, for example, about 1.1 to 2.0 or about 1.1 to 1.8.

[0025] The near-infrared absorption layer 101 containing the first substance has an (average) absorption coefficient in the visible light wavelength region and the near-infrared wavelength region (e.g., about 400 nm to 1000 nm) of about 0.01 to 0.5, and for example, an (average) absorption coefficient in the wavelength region of about 900 nm to 1000 nm (e.g., 940 nm) of about 0.01 to 0.5.

[0026] The optical properties of the near-infrared light absorption layer 101 are substantially similar to the optical properties of the first substance, i.e., the near-infrared light absorption layer 101 selectively absorbs light in a first wavelength region, for example, belonging to a wavelength region of about 700 nm to 1200 nm, and transmits light in the visible light wavelength region.

[0027] The transmission spectrum of the near-infrared absorbing layer 101 is substantially similar to the transmission spectrum of the first material, and the near-infrared absorbing layer 101 absorbs light in the first wavelength region and has a first minimum transmission wavelength (λ min , T1 ) and has a first minimum transmission wavelength (λ min , T1 ) belongs to, for example, about 700 nm to 1100 nm, about 700 nm to 1000 nm, about 700 nm to 990 nm, about 700 nm to 900 nm, about 700 nm to 800 nm, about 750 nm to 1100 nm, about 750 nm to 1000 nm, about 750 nm to 990 nm, about 750 nm to 900 nm, about 750 nm to 800 nm, about 800 nm to 1100 nm, about 800 nm to 1000 nm, about 800 nm to 990 nm, about 800 nm to 900 nm, about 850 nm to 1100 nm, about 850 nm to 1000 nm, about 850 nm to 990 nm, about 850 nm to 900 nm, about 870 nm to 990 nm, or about 890 nm to 990 nm.

[0028] The near infrared absorbing layer 101 is formed of a composition containing a first substance. The composition may further contain a binder and / or a solvent in addition to the first substance.

[0029] The binder is a transparent polymer and is not particularly limited as long as it is a substance that can be mixed with the first substance, disperse the first substance, or bind the first substance. The binder is, for example, a curable binder, and includes, for example, a thermosetting binder, a photocurable binder, or a combination thereof.

[0030] Examples of binders include, but are not limited to, (meth)acryl, methyl cellulose, ethyl cellulose, hydroxypropyl methyl cellulose (HPMC), hydroxylpropyl cellulose (HPC), xanthan gum, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), cyclic olefin polymer (COP), carboxy methyl cellulose, hydroxyl ethyl cellulose, epoxy, silicone, organic-inorganic hybrid materials, copolymers thereof, or combinations thereof.

[0031] The first substance is contained, for example, in an amount of about 0.01 to 50 parts by weight, for example, in an amount of about 0.01 to 30 parts by weight, for example, in an amount of about 0.01 to 20 parts by weight, for example, in an amount of about 0.01 to 15 parts by weight, for example, in an amount of about 0.01 to 10 parts by weight, relative to 100 parts by weight of the binder.

[0032] The near infrared absorbing layer 101 contains a cured product of a first substance and a binder.

[0033] The thickness of the near-infrared light absorption layer 101 is about 10 nm to 1000 nm, and within the above range, for example, about 10 nm to 800 nm, about 10 nm to 700 nm, about 10 nm to 500 nm, about 10 nm to 400 nm, or about 10 nm to 300 nm.

[0034] The multiple metamaterial structures 102a are arranged periodically or randomly and are located below, above, and / or within the near-infrared light absorption layer 101 at a distance from the near-infrared light absorption layer 101.

[0035] 1 and 2, a plurality of metamaterial structures 102a are located under the near-infrared light absorption layer 101 and are separated from the near-infrared light absorption layer 101 by a compensation layer 103, which will be described later. Each metamaterial structure 102a is embedded in and surrounded by the compensation layer 103.

[0036] 3 and 4, a plurality of metamaterial structures 102a are located on top of the near-infrared light absorption layer 101 and are separated from the near-infrared light absorption layer 101 by a compensation layer 103, which will be described later. Each metamaterial structure 102a is embedded in and surrounded by the compensation layer 103.

[0037] 5 to 7, as an example, a plurality of metamaterial structures 102a are located inside the near-infrared light absorption layer 101 and are separated from the near-infrared light absorption layer 101 by a compensation layer 103 described below. Each metamaterial structure 102a is surrounded by the compensation layer 103, and each metamaterial structure 102a surrounded by the compensation layer 103 is embedded in the near-infrared light absorption layer 101.

[0038] The metamaterial structure 102a is a disk-shaped nano-body that absorbs or scatters light in a predetermined wavelength range by localized surface plasmon resonance. The metamaterial structure 102a is, for example, a metal nano-disk, including, but not limited to, gold (Au), silver (Ag), aluminum (Al), copper (Cu), alloys thereof, or combinations thereof.

[0039] As an example, a wavelength region in which localized surface plasmon resonance occurs (hereinafter referred to as the "second wavelength region") overlaps with the first wavelength region, which is the absorption wavelength of the near-infrared absorbing material described above, and the metamaterial structure 102a absorbs or scatters light in the second wavelength region. For example, the second wavelength region belongs to the near-infrared wavelength region. For example, the second wavelength region is narrower than the first wavelength region, and belongs to, for example, the first wavelength region.

[0040] The second wavelength region belongs to, for example, about 700 nm to 1200 nm, and within the above range, for example, about 700 nm to 1100 nm, about 700 nm to 1000 nm, about 700 nm to 990 nm, about 700 nm to 900 nm, about 700 nm to 800 nm, about 750 nm to 1100 nm, about 750 nm to 1000 nm, about 750 nm to 990 nm, about 750 nm to 900 nm, about 750nm to 800nm, about 800nm ​​to 1100nm, about 800nm ​​to 1000nm, about 800nm ​​to 990nm, about 800nm ​​to 900nm, about 850nm to 1100nm, about 850nm to 1000nm, about 850nm to 990nm, about 850nm to 900nm, about 870nm to 990nm, or about 890nm to 990nm.

[0041] The metamaterial structure 102a effectively blocks the transmission of light in the second wavelength region by absorbing or scattering the light in the second wavelength region. The transmission spectrum of the metamaterial structure 102a has a second minimum transmission wavelength (λ min , T2 ) and the second minimum transmission wavelength (λ min , T2) belongs to about 700nm to 1100nm, about 700nm to 1000nm, about 700nm to 990nm, about 700nm to 900nm, about 700nm to 800nm, about 750nm to 1100nm, about 750nm to 1000nm, about 750nm to 990nm, about 750nm to 900nm, about 750nm to 800nm, about 800nm ​​to 1100nm, about 800nm ​​to 1000nm, about 800nm ​​to 990nm, about 800nm ​​to 900nm, about 850nm to 1100nm, about 850nm to 1000nm, about 850nm to 990nm, about 850nm to 900nm, about 870nm to 990nm, or about 890nm to 990nm.

[0042] As an example, the first minimum transmission wavelength (λ min , T1 ) and the second minimum transmission wavelength (λ min , T2 ) respectively belong to, for example, about 700 nm to 1100 nm, about 700 nm to 1000 nm, about 700 nm to 990 nm, about 700 nm to 900 nm, about 760 nm to 800 nm, about 750 nm to 1100 nm, about 750 nm to 1000 nm, about 750 nm to 990 nm, about 750 nm to 900 nm, about 750 nm to 800 nm, about 800 nm to 1100 nm, about 800 nm to 1000 nm, about 800 nm to 990 nm, about 800 nm to 900 nm, about 850 nm to 1100 nm, about 850 nm to 1000 nm, about 850 nm to 990 nm, about 850 nm to 900 nm, about 870 nm to 990 nm, or about 890 nm to 990 nm.

[0043] As an example, the first minimum transmission wavelength (λ min , T1 ) and the second minimum transmission wavelength (λ min , T2 ) is about 100 nm or less, and within the above ranges, is about 80 nm or less, about 70 nm or less, about 50 nm or less, about 40 nm or less, about 30 nm or less, about 20 nm or less, or about 10 nm or less.

[0044] The metamaterial structure 102a is a three-dimensional structure having a predetermined shape and dimension that absorbs or reflects light in the second wavelength region, where the dimension is a diameter (d) and a thickness (t). The dimension of the metamaterial structure 102a is a subwavelength smaller than the wavelength of the light to be reflected or absorbed, i.e., the wavelength belonging to the second wavelength region.

[0045] As an example, the metamaterial structure 102a is a thin nano-body having a flat surface, and the ratio of diameter (d) to thickness (t) of the metamaterial structure 102a is, for example, about 8 or more, about 9 or more, about 10 or more, about 12 or more, or about 15 or more, and within the above ranges, about 8-50, about 9-50, about 10-50, about 12-50, or about 15-50.

[0046] As an example, the diameter (d) of the metamaterial structure 102a is from tens of nanometers to hundreds of nanometers, for example, about 80 nm or more, within the above range, for example, about 80 nm to 500 nm, about 80 nm to 400 nm, 80 nm to 300 nm, or 80 nm to 200 nm.

[0047] As an example, the thickness (t) of the metamaterial structure 102a is from a few nanometers to a few tens of nanometers, for example, about 60 nm or less, about 40 nm or less, about 30 nm or less, or about 20 nm or less, and within the above range, for example, about 1 nm to 60 nm, about 1 nm to 50 nm, about 1 nm to 40 nm, about 1 nm to 30 nm, about 1 nm to 20 nm, or about 1 nm to 15 nm.

[0048] The metamaterial structures 102a have a surface coverage of about 50% or less with respect to the total area of ​​the optical filter 100, and within the above range, for example, about 1% to 50%, about 3% to 50%, about 5% to 50%, about 5% to 40%, about 5% to 30%, about 5% to 20%, about 10% to 50%, about 10% to 40%, or about 10% to 30%. Here, the surface coverage is the area occupied by the multiple metamaterial structures 102a with respect to the total area of ​​the optical filter 100, and is measured by analyzing an image using, for example, an electron microscope, an atomic microscope, or a surface analyzer.

[0049] The metamaterial structure 102a strongly scatters light in the near-infrared wavelength region due to localized surface plasmon resonance, and the scattered light is multiple-absorbed by the near-infrared absorption layer 101, thereby providing a high light absorption effect for light in the near-infrared wavelength region. The amount of light absorbed by such multiple absorption is significantly higher than the amount of light absorbed by light incident from a structure without multiple metamaterial structures 102a, i.e., a planar structure, while passing through the near-infrared absorption layer 101 once. Therefore, a high light absorption synergy effect is provided by the combination of the near-infrared absorption layer 101 and multiple metamaterial structures 102a.

[0050] The compensation layer 103 is located adjacent to the near infrared absorbing layer 101, for example, underneath, on top, and / or on the sides of the near infrared absorbing layer 101. The compensation layer 103 is a thin film laminated to the near infrared absorbing layer 101 or is a coating or passivation layer that surrounds each metamaterial structure 102a.

[0051] The compensation layer 103 is interposed between the near-infrared light absorption layer 101 and the metamaterial structure 102a to separate the near-infrared light absorption layer 101 and the metamaterial structure 102a, and prevents the metamaterial structure 102a from directly contacting the near-infrared light absorption layer 101.

[0052] If the near-infrared absorbing layer 101 and the metamaterial structure 102a are in direct contact without the compensation layer 103, the electric field concentrated at the end of the metamaterial structure 102a will cause a sudden decrease or increase in the refractive index in the main absorption wavelength region of the near-infrared absorbing layer 101, i.e., the above-mentioned first wavelength region and its vicinity, and such a fluctuation in the refractive index of the near-infrared absorbing layer 101 will interfere with the absorption synergy effect achieved by the combination of the near-infrared absorbing layer 101 and the metamaterial structure 102a described above.

[0053] Therefore, by interposing the compensation layer 103 between the near-infrared absorption layer 101 and the metamaterial structure 102a, direct contact between the near-infrared absorption layer 101 and the metamaterial structure 102a is prevented, and the refractive index fluctuation of the near-infrared absorption layer 101 due to the metamaterial structure 102a is reduced or prevented, thereby reducing or preventing the interference with the light absorption synergy effect due to the combination of the near-infrared absorption layer 101 and the metamaterial structure 102a.

[0054] The compensation layer 103 contains a second substance different from the first substance contained in the near-infrared light absorption layer 101. The second substance is, for example, a substance that does not substantially absorb light in the near-infrared wavelength region, for example, a substance that does not substantially absorb light in the first wavelength region that is mainly absorbed in the near-infrared light absorption layer 101. For example, the second substance is a near infrared transmission material, which is a substance that transmits at least light in a wavelength region of about 700 nm to 1200 nm without substantially absorbing it.

[0055] For example, the maximum extinction coefficient (k) of the second substance in the wavelength region of about 700 nm to 1200 nm is less than about 0.01, and within the above range, it is about 0.007 or less, about 0.005 or less, about 0.003 or less, about 1×10 -3 Below, approximately 1×10 -5 or less, or about 1×10 -7 The following is the result.

[0056] For example, the second substance is a transparent substance that does not substantially absorb light in the near-infrared wavelength region and the visible wavelength region, for example, a visible light-near-infrared transparent substance, which transmits light in at least the wavelength region of about 400 nm to 1200 nm without substantially absorbing it.

[0057] For example, the maximum extinction coefficient (k) of the second substance in the wavelength region of about 400 nm to 1200 nm is less than about 0.01, and within the above range, it is about 0.007 or less, about 0.005 or less, about 0.003 or less, about 1×10 -3 Below, approximately 1×10 -5 or less, or about 1×10 -7 The following is the result.

[0058] The refractive index of the second substance is higher or lower than the refractive index of the first substance contained in the near infrared absorbing layer 101. For example, the average refractive index (n) of the second substance in the wavelength region of about 700 nm to 1200 nm is about 1.2 to 3.0, about 1.2 to 2.8, about 1.2 to 2.8, or about 1.4 to 2.6, but is not limited thereto.

[0059] For example, the refractive index of the second substance is higher than the refractive index of the first substance contained in the near-infrared absorption layer 101, and the average refractive index (n) of the second substance in the wavelength region of approximately 700 nm to 1200 nm is approximately 1.01 to 1.5 times the average refractive index of the first substance in the wavelength region of approximately 700 nm to 1200 nm.

[0060] For example, the refractive index of the second substance is lower than the refractive index of the first substance contained in the near-infrared absorption layer 101, and the average refractive index (n) of the second substance in the wavelength region of approximately 700 nm to 1200 nm is approximately 0.70 to 0.99 times the average refractive index of the first substance in the wavelength region of approximately 700 nm to 1200 nm.

[0061] The second material is selected from inorganic, organic, organic-inorganic, or combinations thereof that satisfy the above-mentioned physical properties, and includes, but is not limited to, oxides, nitrides, oxynitrides, halides, sulfides, chalcogenides, semiconductor elements, semiconductor compounds, photocurable polymers, thermosetting polymers, high heat resistant polymers, or combinations thereof. For example, the second material may be silicon oxide, titanium oxide, zinc oxide, indium oxide, tin oxide, indium zinc oxide, indium tin oxide, indium aluminum oxide, zirconium oxide, aluminum oxide, borosilicate, silicon nitride, silicon oxynitride, barium fluoride (BaF 2 ), calcium fluoride (CaF 2 ), lithium fluoride (LiF), magnesium fluoride (MgF 2 ), potassium chloride (KCl), potassium bromide (KBr), cesium iodide (CsI), zinc sulfide, chalcogenides, germanium, gallium arsenide, polyimides, polyvinylpyrrolidone, or combinations thereof.

[0062] The optical properties of the compensation layer 103 are substantially similar to those of the second material, i.e., the compensation layer 103 transmits light in a first wavelength region, for example, about 700 nm to 1200 nm, without absorbing it, and transmits light in the visible-infrared wavelength region, for example, about 400 nm to 1200 nm, without substantially absorbing it.

[0063] The compensation layer 103 is formed from a composition including a second material. The composition may further include a binder and / or a solvent in addition to the second material described above. The binder is as described above.

[0064] The thickness of the compensation layer 103 is thicker than the thickness of the metamaterial structure 102a, for example, the thickness of the compensation layer 103 is about 1.2 times or more, about 1.5 times or more, or about 2 times or more, the thickness of the metamaterial structure 102a. For example, the thickness of the compensation layer 103 is about 1.2 to 20 times, about 1.5 to 20 times, or about 2 to 20 times the thickness of the metamaterial structure 102a, but is not limited thereto.

[0065] The thickness of the compensation layer 103 is thinner than that of the near-infrared absorbing layer 101, and for example, the thickness ratio between the compensation layer 103 and the near-infrared absorbing layer 101 is about 1:2 to 1:100. For example, the thickness ratio between the compensation layer 103 and the near-infrared absorbing layer 101 is about 1:3 to 1:80, about 1:4 to 1:50, or about 1:4 to 1:30, but is not limited thereto.

[0066] The base layer 104 is located below the near-infrared light absorption layer 101, the metamaterial structure 102a, and the compensation layer 103, and supports the near-infrared light absorption layer 101, the metamaterial structure 102a, and the compensation layer 103. The base layer 104 is a transparent base layer and has a light transmittance of, for example, about 85% or more, about 90% or more, or about 95% or more in a wavelength region of about 400 nm to 1000 nm.

[0067] The substrate layer 104 may be organic, inorganic, organic-inorganic, or a combination thereof, such as, but not limited to, an oxide, a nitride, a sulfide, a fluoride, a polymer, or a combination thereof, such as, but not limited to, glass, silicon oxide, aluminum oxide, magnesium fluoride, polystyrene, polymethyl methacrylate, polycarbonate, or a combination thereof.

[0068] As described above, the optical filter 100 exhibits high light absorption characteristics for light in the near-infrared wavelength region despite its small thickness due to the combination of the near-infrared light absorption layer 101 and the multiple metamaterial structures 102a.

[0069] Specifically, the optical filter 100 scatters light in the near-infrared wavelength region by localized surface plasmon resonance generated from the multiple metamaterial structures 102a, and the near-infrared absorption layer 101 absorbs the scattered light in multiple ways, thereby providing a high light absorption effect for light in the near-infrared wavelength region. The amount of light absorbed by such multiple absorption is significantly higher than the amount of light absorbed by light incident from a structure without multiple metamaterial structures 102a, i.e., a planar structure, while passing through the near-infrared absorption layer 101 once. Therefore, a synergistic effect of high light absorption properties is provided by the combination of the near-infrared absorption layer 101 and the multiple metamaterial structures 102a.

[0070] On the other hand, as described above, by interposing the compensation layer 103 between the near-infrared light absorption layer 101 and the metamaterial structure 102a, direct contact between the near-infrared light absorption layer 101 and the metamaterial structure 102a is prevented, thereby preventing the refractive index of the near-infrared light absorption layer 101 from varying depending on the wavelength due to the metamaterial structure 102a, thereby reducing or preventing interference with the light absorption synergy effect due to the combination of the above-mentioned near-infrared light absorption layer 101 and the metamaterial structure 102a.

[0071] The transmission spectrum of the optical filter 100 overlaps with a first wavelength region absorbed by the near-infrared absorption layer 101 and a second wavelength region absorbed or scattered by the metamaterial structure 102a, and has a wavelength width wider than the first wavelength region and the second wavelength region. For example, the wavelength width at 50% transmittance of the transmission spectrum of the optical filter 100 is about 100 nm or more, and within the above range, it is about 120 nm or more, about 140 nm or more, about 150 nm or more, about 180 nm or more, about 200 nm or more, about 210 nm or more, about 220 nm or more, about 230 nm or more, about 240 nm or more, or about 250 nm or more, and is about 100 nm to 300 nm, about 120 nm to 300 nm, about 140 nm to 300 nm, about 150 nm to 300 nm, about 180 nm to 300 nm, about 200 nm to 300 nm, about 210 nm to 300 nm, about 220 nm to 300 nm, about 230 nm to 300 nm, about 240 nm to 300 nm, or about 250 nm to 300 nm. Therefore, the optical filter 100 exhibits high light absorption characteristics over a wide wavelength range within the near-infrared wavelength region.

[0072] In addition, the optical filter 100 can increase the transmittance of light in the visible light wavelength range by combining the near-infrared absorbing layer 101 and the metamaterial structure 102a, compared to the near-infrared absorbing layer 101 alone or the metamaterial structure 102a alone.

[0073] As a result, the optical filter 100 increases the transmittance of light in the visible wavelength region and increases the absorbance in the near-infrared wavelength region, thereby further enhancing the selective filtering effect in the near-infrared wavelength region.

[0074] As an example, the average transmittance (T VIS ) is more than about 80%, and within the above range, is about 82% or more, about 85% or more, about 90% or more, about 91% or more, about 92% or more, about 94% or more, about 95% or more, about 96% or more, about 97% or more, about 98% or more, or about 99% or more. The visible light wavelength region here is a predetermined wavelength region belonging to, for example, about 400 nm or more and less than 700 nm, for example, about 430 nm to 565 nm.

[0075] As an example, the average transmittance (T NIR ) is lower than that of the near-infrared light absorption layer 101 alone or the metamaterial structure 102a alone, for example, about 1.5 times or more, about 2 times or more, about 3 times or more, about 4 times or more, or about 5 times or more, for example, about 1.5 to 50 times, about 2 to 50 times, about 3 to 50 times, about 4 to 50 times, or about 5 to 50 times lower. The average transmittance (T NIR ) is, for example, less than about 10%, and within the above range, is about 8% or less, about 7% or less, about 5% or less, about 4% or less, about 3% or less, about 2% or less, about 1% or less, or about 0.5% or less. Here, the near-infrared wavelength region is, for example, a predetermined wavelength region belonging to about 700 nm to 1200 nm, and is about 700 nm to 800 nm or about 890 nm to 990 nm.

[0076] As an example, the ratio of the average transmittance of the optical filter 100 in the near-infrared wavelength region to the average transmittance of the optical filter 100 in the visible wavelength region (T NIR / T VIS ) is lower than that of the near-infrared absorption layer 101 alone or the metamaterial structure 102a alone, and is, for example, about 1.5 times or more, about 2 times or more, about 3 times or more, about 4 times or more, or about 5 times or more lower, and is, for example, about 1.5 to 50 times, about 2 to 50 times, about 3 to 50 times, about 4 to 50 times, or about 5 to 50 times lower. The ratio (T NIR / T VIS ) is, for example, about 0.1 or less, and within the above ranges, about 0.08 or less, about 0.07 or less, about 0.05 or less, about 0.04 or less, about 0.03 or less, or about 0.02 or less.

[0077] The optical filter 100 is applicable to all applications for filtering light in a predetermined wavelength region, and is effectively applied to a near-infrared blocking filter for filtering light in a near-infrared wavelength region, for example. The optical filter 100 is usefully applied to, for example, an image sensor, a camera module, and an electronic device including the same. The electronic device may be, but is not limited to, a digital camera, a camcorder, a surveillance camera such as a CCTV, an automobile camera, a robot camera, a medical device camera, a mobile phone with an internal or external camera, a computer with an internal or external camera, a laptop computer with an internal or external camera, and the like.

[0078] An example of a camera module equipped with the above-described optical filter 100 will now be described.

[0079] FIG. 8 is a schematic diagram illustrating an example of a camera module according to an embodiment of the present invention.

[0080] Referring to FIG. 8, the camera module 20 includes a lens barrel 21, a housing 22, an optical filter 100, and an image sensor 23.

[0081] Lens barrel 21 includes one or more lenses for capturing an image of a subject, and the lenses are arranged along an optical axis direction. Here, the optical axis direction is the up-down direction of lens barrel 21. Lens barrel 21 is accommodated inside housing 22 and is coupled to housing 22. Lens barrel 21 moves in the optical axis direction within housing 22 for autofocus.

[0082] The housing 22 is for supporting and housing the lens barrel 21, and the housing 22 has an open shape in the optical axis direction and is designed to be characteristically vertical using a prism, etc. Therefore, light incident from one side of the housing 22 passes through the lens barrel 21 and the optical filter 100 and reaches the image sensor 23.

[0083] An actuator for moving the lens barrel 21 in the optical axis direction is provided in the housing 22. The actuator includes a voice coil motor (VCM) including a magnet and a coil. However, various methods other than the actuator, such as a mechanical drive method or a piezoelectric drive method using a piezoelectric element, may be used.

[0084] The optical filter 100 is as described above.

[0085] The image sensor 23 collects an image of a subject and stores it as data, and the stored data is displayed as a video through a display medium.

[0086] The image sensor 23 is mounted on and electrically coupled to a substrate (not shown), which may be, for example, a printed circuit board (PCB), or is electrically coupled to a printed circuit board, which may be, for example, a flexible printed circuit board (FPCB).

[0087] The image sensor 23 collects light that has passed through the lens barrel 21 and the optical filter 100 to generate a video signal, and is a complementary metal-oxide semiconductor (CMOS) image sensor and / or a charge coupled device (CCD) image sensor.

[0088] FIG. 9 is a schematic diagram illustrating another example of a camera module according to an embodiment of the present invention.

[0089] 9, a camera module 20 according to this embodiment includes a lens barrel 21, a housing 22, an optical filter 100, and an image sensor 23, similar to the above-described embodiments.

[0090] However, the camera module 20 according to this embodiment differs from the above-described embodiments in that the image sensor 23 abuts the optical filter 100, and for example, the optical filter 100 and the image sensor 23 are integrally formed and included in an optical filter-integrated image sensor 23A.

[0091] An example of the optical filter integrated image sensor 23A will be described below with reference to the drawings. As an example of the image sensor, a CMOS image sensor will be described.

[0092] FIG. 10 is a cross-sectional view showing an example of an optical filter integrated image sensor according to an embodiment of the present invention.

[0093] The optical filter integrated image sensor 23A according to an embodiment of the present invention includes an image sensor 23 including a semiconductor substrate 110, a lower insulating layer 60, a color filter layer 70, and an upper insulating layer 80, and an optical filter 100.

[0094] The semiconductor substrate 110 is a silicon substrate on which photo-sensing elements (50a, 50b, 50c) and transmission transistors (not shown) are integrated. The photo-sensing elements (50a, 50b, 50c) are photodiodes. For example, the photo-sensing element 50a is a blue light-sensing element 50a that senses light in a blue wavelength region that has passed through a blue filter 70a described later, the photo-sensing element 50b is a green light-sensing element 50b that senses light in a green wavelength region that has passed through a green filter 70b described later, and the photo-sensing element 50c is a red light-sensing element 50c that senses light in a red wavelength region that has passed through a red filter 70c described later. The photo-sensing elements (50a, 50b, 50c) and the transmission transistors are integrated for each pixel. The photo-sensing elements (50a, 50b, 50c) sense light, and the sensed information is transmitted by the transmission transistor.

[0095] Metal wiring (not shown) and pads (not shown) are also formed on the semiconductor substrate 110. The metal wiring and pads are made of a metal having a low resistivity to reduce signal delay, such as, but not limited to, aluminum (Al), copper (Cu), silver (Ag), and alloys thereof. However, without being limited to the above structure, the metal wiring and pads may be located under the photo-sensing elements (50a, 50b, 50c).

[0096] Formed on the metal lines and pads is a lower insulating layer 60. The lower insulating layer 60 is made of inorganic insulating materials such as silicon oxide and / or silicon nitride, or low dielectric constant (low K) materials such as SiC, SiCOH, SiCO, and SiOF.

[0097] A color filter layer 70 is formed on the lower insulating layer 60. The color filter layer 70 includes a blue filter 70a formed in a blue pixel, a green filter 70b formed in a green pixel, and a red filter 70c formed in a red pixel. However, the present invention is not limited thereto, and at least one of the blue filter 70a, the green filter 70b, and the red filter 70c may be replaced with a yellow filter, a cyan filter, or a magenta filter.

[0098] An upper insulating layer 80 is formed on the color filter layer 70. The upper insulating layer 80 reduces steps caused by the color filter layer 70 and provides a flat surface. The upper insulating layer 80 is made of an inorganic insulating material such as silicon oxide and / or silicon nitride, or an organic insulating material. The upper insulating layer 80 may be omitted in some cases.

[0099] The optical filter 100 is formed on the upper insulating layer 80. The optical filter 100 includes the near-infrared absorbing layer 101, the multiple metamaterial structures 102a, the compensation layer 103, and the substrate layer 104 as described above, and effectively transmits light in the visible wavelength region, for example, and effectively filters or blocks light in wavelength regions other than visible light, such as the near-infrared wavelength region. When the above-mentioned upper insulating layer 80 is the same as the substrate layer 104 of the optical filter 100, one of the upper insulating layer 80 and the substrate layer 104 is omitted. The detailed description of the optical filter 100 is as described above.

[0100] A condenser lens (not shown) is disposed on the optical filter 100. However, the optical filter 100 may be disposed on the condenser lens. The condenser lens controls the direction of the incident light to condense the light to one point. The condenser lens may be, for example, cylindrical or hemispherical, but is not limited thereto.

[0101] A dual bandpass filter (not shown) is disposed below the condenser lens. The dual bandpass filter selectively transmits light in at least two wavelength regions of the incident light, for example, selectively transmits light in the visible light wavelength region and the near infrared wavelength region.

[0102] As described above, the optical filter 100 effectively transmits light in the visible light region and effectively blocks light in the near-infrared wavelength region, thereby transmitting pure light in the visible light region to the image sensor, thereby reducing or preventing crosstalk that occurs when signals generated by light in the visible light region and signals generated by light in the near-infrared wavelength region cross over or mix together.

[0103] In particular, the optical filter 100 has a thin thickness of about 10 μm or less, about 5 μm or less, about 3 μm or less, about 2 μm or less, about 1 μm or less, about 700 nm or less, about 10 nm to 10 μm, about 10 nm to 5 μm, about 10 nm to 3 μm, about 10 nm to 2 μm, about 10 nm to 1 μm, or about 10 nm to 700 nm, and is thereby embodied as an integrated image sensor 23A in which the optical filter 100 and the image sensor 23 are integrated, thereby achieving thin image sensors, camera modules, and electronic devices equipped therewith.

[0104] FIG. 11 is a cross-sectional view showing another example of an optical filter integrated image sensor according to an embodiment of the present invention.

[0105] The optical filter-integrated image sensor 23A according to this embodiment includes an image sensor 23 including a semiconductor substrate 110 on which light-sensing elements (50a, 50b, 50c) are integrated, a lower insulating layer 60, and a color filter layer 70, and an optical filter 100, similar to the above-described embodiments.

[0106] However, unlike the embodiment of Fig. 10 described above, the integrated image sensor 23A according to the present embodiment has the optical filter 100 located below the color filter layer 70. Although Fig. 11 shows an example in which the optical filter 100 is located between the lower insulating layer 60 and the color filter layer 70, the present invention is not limited thereto and the optical filter 100 may be located between the semiconductor substrate 110 and the lower insulating layer 60. When the lower insulating layer 60 is the same as the base layer 104 of the optical filter 100, either the lower insulating layer 60 or the base layer 104 of the optical filter 100 is omitted.

[0107] FIG. 12 is a cross-sectional view showing still another example of an optical filter integrated image sensor according to an embodiment of the present invention.

[0108] The optical filter-integrated image sensor 23A according to this embodiment includes an image sensor 23 including a semiconductor substrate 110 on which photo-sensing elements (50a, 50b, 50c) are integrated, a lower insulating layer 60, a color filter layer 70, and an upper insulating layer 80, and an optical filter 100, similar to the embodiment of FIG. 10 described above.

[0109] 10, the optical filter integrated image sensor 23A according to the present embodiment further includes a photo-sensing element 50d for sensing light in the infrared wavelength region integrated on the semiconductor substrate 110. The color filter layer 70 may include a visible light blocking filter, a transparent filter, or a white filter (not shown) at a position corresponding to the photo-sensing element 50d, or may have an empty space without a separate filter.

[0110] The optical filters 100 are disposed only above or below the blue filter 70a, the green filter 70b, and the red filter 70c, but not above or below the clear or white filters.

[0111] As an example, light-sensing element 50d may be used as an auxiliary element for a telephoto camera to improve the image sensor's sensitivity in low-light environments, or to sharpen visible light images obscured by fog or fine dust.

[0112] As an example, the light sensing element 50d may be an infrared sensor that senses light in the near infrared wavelength region. The infrared sensor can enhance the sensing capability of a three-dimensional image by widening the dynamic range for finely distinguishing between black and white and light and dark. The infrared sensor may be, for example, a biometric sensor, such as, but not limited to, an iris sensor, a distance sensor, a fingerprint sensor, a blood vessel distribution sensor, etc.

[0113] FIG. 13 is a cross-sectional view showing another example of an optical filter integrated image sensor according to an embodiment of the present invention.

[0114] The optical filter-integrated image sensor 23A according to this embodiment includes an image sensor 23 including a semiconductor substrate 110 on which light-sensing elements (50a, 50b, 50c, 50d) are integrated, a lower insulating layer 60, and a color filter layer 70, and an optical filter 100, similar to the embodiment of FIG. 12 described above.

[0115] However, unlike the embodiment of Fig. 12, the optical filter integrated image sensor 23A according to the present embodiment has the optical filter 100 located below the color filter layer 70. Although Fig. 13 shows an example in which the optical filter 100 is located between the lower insulating layer 60 and the color filter layer 70, the present invention is not limited thereto and the optical filter 100 may be located between the semiconductor substrate 110 and the lower insulating layer 60. When the lower insulating layer 60 is the same as the base layer 104 of the optical filter 100, either the lower insulating layer 60 or the base layer 104 of the optical filter 100 is omitted.

[0116] FIG. 14 is a schematic diagram of an electronic device according to one embodiment of the present invention.

[0117] 14, an electronic device 1300 according to an embodiment of the present invention includes a processor 1320, a memory 1330, a sensor 1340, and a display device 1350 electrically coupled to a bus 1310. The sensor 1340 may be an image sensor (e.g., 23, 23A), a camera module 20, or a combination thereof, as described above, and may include an optical filter 100 as described above. The processor 1320 executes a memory program to perform at least one function, including a function to control the sensor 1340. The processor 1320 further executes the memory program to cause an image to be displayed on the display device 1350. The processor 1320 generates an output.

[0118] The above-mentioned embodiments will be described in more detail with reference to the following examples, which are merely for illustrative purposes and are not intended to limit the scope of the present invention.

[0119] Optical Filter Design I

[0120] Example 1 A 50 nm thick high refractive index layer (refractive index 1.65) was formed on a glass substrate, and multiple Ag nanodisks with a diameter of 132 nm and a thickness of 10 nm were placed on top of it with a surface coverage of 20%. Another 50 nm thick high refractive index layer (refractive index 1.65) was then formed on top of it to form a compensation layer with a thickness of about 100 nm in which multiple Ag nanodisks were embedded. Next, a near-infrared absorbing material (Epolin, Epolight) was applied to the compensation layer. TM A composition was mixed with 15% by weight of 1178) and 85% by weight of a cycloolefin polymer (poly[[octahydro-5-(methoxycarbonyl)-5-methyl-4,7-methano-1H-indene-1,3-diyl]-1,2-ethanediyl], Sigma-Aldrich, CAS No. 123322-60-1) in chloroform, and the mixture was spin-coated (3000 rpm, 20 seconds) to form a near-infrared absorbing layer of approximately 400 nm thickness to design an optical filter (structures in Figures 1 and 2).

[0121] The compensation layer has an average refractive index (n) of 1.65 and a maximum absorption coefficient (k) of 0 in the visible light wavelength region and the near infrared wavelength region (400 nm to 1000 nm).

[0122] The near-infrared absorbing layer has an average refractive index (n) of 1.47 in the visible light wavelength region and the near-infrared wavelength region (400 nm to 1000 nm), and a maximum absorption coefficient (k) of 0.16.

[0123] The refractive index and extinction coefficient were measured from the change in polarization characteristics (Delta, Psi) using an Ellipsometry device (JA Woollam).

[0124] Example 2 An optical filter was designed in the same manner as in Example 1, except that the surface coverage of the multiple Ag nanodisks was changed to 19%.

[0125] Example 3 An optical filter was designed in the same manner as in Example 1, except that the surface coverage of the multiple Ag nanodisks was changed to 18%.

[0126] Comparative Example 1 Multiple Ag nanodisks and near-infrared absorbing materials (Epolin, Epolight) were fabricated on a glass substrate without a compensation layer. TM An optical filter was designed in which a near-infrared absorbing layer of approximately 500 nm thickness was formed by spin coating (3000 rpm, 20 seconds) a composition in which 15 wt% of 1178) and 85 wt% of a cycloolefin polymer (poly[[octahydro-5-(methoxycarbonyl)-5-methyl-4,7-methano-1H-indene-1,3-diyl]-1,2-ethanediyl], Sigma-Aldrich, CAS No. 123322-60-1) were mixed in chloroform.

[0127] Comparative Example 2 An optical filter was designed in which multiple Ag nanodisks with a diameter of 132 nm and a thickness of 10 nm were arranged on a glass substrate with a surface coverage of 20%, without a near-infrared absorption layer or a compensation layer, and a cycloolefin polymer (poly[[octahydro-5-(methoxycarbonyl)-5-methyl-4,7-methano-1H-indene-1,3-diyl]-1,2-ethanediyl], Sigma-Aldrich, CAS No. 123322-60-1) solution was spin-coated (3000 rpm, 20 s) on top to form a polymer layer with a thickness of approximately 500 nm.

[0128] Reference example 1 Without a compensation layer, multiple Ag nanodisks with a diameter of 160 nm and a thickness of 10 nm were placed on a glass substrate with a surface coverage of 20%, and a near-infrared absorbing material (Epolin, Epolight) was deposited on top of them. TMAn optical filter was designed in which a near-infrared absorbing layer of approximately 500 nm thickness was formed by spin coating (3000 rpm, 20 seconds) a composition in which 15 wt% of 1178) and 85 wt% of a cycloolefin polymer (poly[[octahydro-5-(methoxycarbonyl)-5-methyl-4,7-methano-1H-indene-1,3-diyl]-1,2-ethanediyl], Sigma-Aldrich, CAS No. 123322-60-1) were mixed in chloroform.

[0129] Rating I An optical simulation was performed on the optical filters according to the embodiment, the comparative example, and the reference example using finite-different time domain (FDTD) software manufactured by Lumerical Corporation.

[0130] The results are shown in Table 1 and FIG.

[0131] FIG. 15 is a graph showing the transmission spectra of the optical filters according to Example 1, Comparative Example 1, and Reference Example 1, and FIG. 16 is a graph showing the transmission spectra of the optical filters according to Example 2, Comparative Example 1, and Reference Example 1.

[0132] [Table 1] *λ min、T :Minimum transmission wavelength *T NIR : Average transmittance in the near infrared (890nm to 990nm) wavelength range *T VIS : Average transmittance in the visible light (430nm to 565nm) wavelength range *T NIR / T VIS : Ratio of average transmittance in the near infrared wavelength range to average transmittance in the visible wavelength range

[0133] 15 and 16, it was confirmed that the optical filter according to the embodiment has a higher transmittance in the visible light wavelength region (e.g., greater than or equal to about 400 nm and less than 700 nm, e.g., about 430 nm to 565 nm) and a lower transmittance in the near-infrared wavelength region (e.g., about 890 nm to 990 nm) than the optical filters according to the comparative example and reference example. From these results, it was confirmed that the optical filter according to the embodiment has a more pronounced effect of improving the optical properties due to the combination of the near-infrared absorption layer and the metamaterial structure than the optical filter according to the comparative example, and that such an improvement in the optical properties is even more pronounced than the optical filter according to the reference example.

[0134] Optical Filter Design II

[0135] Examples 4 to 10 An optical filter was designed in the same manner as in Example 1, except that the thickness of the compensation layer and the diameter of the Ag nanodisks were changed as shown in Table 2.

[0136] Rating II An optical simulation was performed on the optical filters according to the embodiment, the comparative example, and the reference example using FDTD software.

[0137] The results are shown in Table 2.

[0138] [Table 2] *Diameter of Ag nanodisk: T NIR The diameter at which is the minimum *λ min , T :Minimum transmission wavelength *T NIR : Average transmittance in the near infrared (890nm to 990nm) wavelength range *T VIS : Average transmittance in the visible light (430nm to 565nm) wavelength range *T NIR / T VIS: Ratio of average transmittance in the near infrared wavelength range to average transmittance in the visible wavelength range

[0139] Referring to Table 2, it was confirmed that the optical filter according to the embodiment has a higher transmittance in the visible light wavelength region (e.g., greater than or equal to about 400 nm and less than 700 nm, e.g., about 430 nm to 565 nm) and a lower transmittance in the near-infrared wavelength region (e.g., about 890 nm to 990 nm) than the optical filters according to the comparative example and reference example. From this, it was confirmed that the optical filter according to the embodiment has a more pronounced effect of improving the optical properties due to the combination of the near-infrared absorption layer and the metamaterial structure than the optical filter according to the comparative example, and that such an improvement in the optical properties is even more pronounced than the optical filter according to the reference example.

[0140] Optical Filter Design III

[0141] Example 11 Ag nanodisks with a diameter of 144 nm and a thickness of 10 nm were dipped into a high refractive index polymer solution with a refractive index of 1.65, then dried and coated to a thickness of about 15 nm to prepare polymer-capped Ag nanodisks. Next, the polymer-capped Ag nanodisks were placed on a glass substrate with a surface coverage of 20%, and a near-infrared absorbing material (Epolin, Epolight) was applied on top of them. TM A composition was mixed with 15% by weight of 1178) and 85% by weight of a cycloolefin polymer (poly[[octahydro-5-(methoxycarbonyl)-5-methyl-4,7-methano-1H-indene-1,3-diyl]-1,2-ethanediyl], Sigma-Aldrich, CAS No. 123322-60-1) in chloroform, and the mixture was spin-coated (3000 rpm, 20 seconds) to form a near-infrared absorbing layer of approximately 500 nm thickness to design an optical filter (structures in Figures 5 and 6).

[0142] Rating III An optical simulation was performed on the optical filters according to the embodiment, the comparative example, and the reference example using FDTD software.

[0143] The results are shown in Table 3 and Figure 17.

[0144] FIG. 17 is a graph showing the transmission spectra of the optical filters according to Example 11, Comparative Example 1, and Reference Example 1.

[0145] [Table 3]

[0146] 17, it was confirmed that the optical filter according to the embodiment has a higher transmittance in the visible light wavelength region (e.g., greater than or equal to about 400 nm and less than 700 nm, e.g., about 430 nm to 565 nm) and a lower transmittance in the near-infrared wavelength region (e.g., about 890 nm to 990 nm) than the optical filters according to the comparative example and reference example. From this, it was confirmed that the optical filter according to the embodiment has a more pronounced effect of improving the optical properties due to the combination of the near-infrared absorption layer and the metamaterial structure than the optical filter according to the comparative example, and that such an improvement in the optical properties is even more pronounced than the optical filter according to the reference example.

[0147] Although the embodiment of the present invention has been described in detail above, the present invention is not limited thereto, and various modifications can be made without departing from the technical scope of the present invention. [Explanation of symbols]

[0148] 20 Camera Module 21 Range Barrel 22 Housing 23 Image Sensor 23A Optical filter integrated image sensor 50a, 50b, 50c, 50d Light sensing element 60 Lower insulation layer 70 color filter layers 70a, 70b, 70c Color Filters 80 Upper insulating layer 100 Optical Filters 101 Near-infrared absorption layer 102a Metamaterial Structure 103 Compensation layer 104 Base material layer 110 Semiconductor substrate 1300 Electronic equipment 1310 Bus 1320 Processor 1330 Memory 1340 Sensor 1350 Display device

Claims

1. a near-infrared light absorption layer including a first substance that absorbs light in a first wavelength region belonging to the near-infrared wavelength region; a compensation layer disposed adjacent to the near infrared light absorption layer, the compensation layer comprising a second material different from the first material; a metamaterial structure positioned apart from the near infrared absorbing layer via the compensation layer and absorbing or reflecting light in a second wavelength region overlapping the first wavelength region, The optical filter has an average transmittance of more than 80% in the wavelength range of 430 nm to 565 nm; The optical filter has an average transmittance of less than 10% in the wavelength region of 700 nm to 800 nm or 890 nm to 990 nm.

2. The optical filter of claim 1 , wherein the metamaterial structure is not in direct contact with the near-infrared light absorption layer.

3. the compensation layer is located below or above the near infrared absorbing layer; 2. The optical filter of claim 1, wherein the metamaterial structure is embedded within the compensation layer.

4. The optical filter of claim 1 , wherein the compensation layer surrounds the metamaterial structure.

5. 5. The optical filter of claim 4, wherein the metamaterial structure surrounded by the compensation layer is embedded within the near infrared light absorption layer.

6. The optical filter of claim 1 , wherein the second material transmits light in the first wavelength region.

7. 2. The optical filter of claim 1, wherein the second material has a maximum extinction coefficient (k) of less than 0.01 in the wavelength range of 700 nm to 1200 nm.

8. 2. The optical filter according to claim 1, wherein the second material has an average refractive index (n) of 1.4 to 2.6 in the wavelength range of 700 nm to 1200 nm.

9. 10. The optical filter of claim 1, wherein the second material comprises an oxide, a nitride, an oxynitride, a halide, a sulfide, a chalcogenide, a semiconductor element, a semiconductor compound, an organic material, or a combination thereof.

10. 2. The optical filter of claim 1, wherein the compensation layer has a thickness that is 1.2 to 20 times the thickness of the metamaterial structure.

11. 2. The optical filter of claim 1, wherein a thickness ratio of the compensation layer to the near infrared absorbing layer is 1:4 to 1:

50.

12. The transmission spectrum of the first material has a first minimum transmission wavelength that belongs to the first wavelength region, a transmission spectrum of the metamaterial structure having a second minimum transmission wavelength in the second wavelength region; 2. The optical filter according to claim 1, wherein the first minimum transmission wavelength and the second minimum transmission wavelength are each in the range of 700 nm to 990 nm.

13. 13. The optical filter according to claim 12, wherein a difference between the first minimum transmission wavelength and the second minimum transmission wavelength is 100 nm or less.

14. 2. The optical filter according to claim 1, wherein a ratio of an average transmittance of the optical filter in a near-infrared wavelength region to an average transmittance of the optical filter in a visible wavelength region is 0.07 or less.

15. A camera module comprising the optical filter according to any one of claims 1 to 14.

16. a semiconductor substrate including a plurality of photodiodes; and the optical filter according to any one of claims 1 to 14 located on the semiconductor substrate.

17. The image sensor of claim 16, further comprising a color filter located below or above the optical filter.

18. A camera module comprising the image sensor according to claim 16.

19. 16. An electronic device comprising the camera module of claim 15.

20. 20. An electronic device comprising the camera module of claim 18.

Images