Composite photosensitive structure and manufacturing method thereof

Abstract

A composite photosensitive structure and a method of preparing the same, the composite photosensitive structure including a photosensitive element and a near-infrared absorbing layer formed on the photosensitive element wherein the near-infrared absorbing layer includes a copper complex, the copper complex is formed of a copper compound for providing copper ions, a phosphonic acid represented by Formula 1 herein, and at least one phosphorus-containing compound represented by Formula 2 to Formula 4 herein, and wherein the near-infrared absorbing layer has an OD value of greater than 4 for a wavelength of incident light of 930 nm to 950 nm. According to the invention, the filter film is directly formed on the photosensitive element to replace a traditional optical filter assembly, so that the size of an assembled finished product is reduced; the filter film can be further processed and shaped to have a microlens function.

Description

Technical Field

[0001] The present invention relates to a composite photosensitive structure, and in particular to a composite photosensitive structure comprising a photosensitive element and a near-infrared absorption layer formed thereon. Background Art

[0002] The known photosensitive elements roughly include components such as microlenses, color filter layers, photoelectric conversion layers, and drive circuits. The photosensitive element array can be made on a wafer through a multi-pass photolithography process and then cut to form a photosensitive element. In addition to being sensitive to visible light, the photoelectric conversion layer is also sensitive to part of near-infrared light, that is, the detection wavelength range includes visible light and part of near-infrared light. However, the electrical signal generated by the detection of near-infrared light is regarded as an interference signal, which interferes with the display of normal images. Therefore, it is expected to effectively filter out infrared light from entering the photoelectric conversion layer. In the past, when the photosensitive element was assembled into an optical lens, an independent external near-infrared filter was usually set on the light incident side to achieve the purpose of filtering out near-infrared light.

[0003] However, with the increasing demand for image quality, the problem of using external filters to filter out near-infrared rays has gradually emerged. In addition to the fact that the visible light transmittance of the external near-infrared filter is not high enough, which reduces the amount of incident light on the photoelectric conversion layer, there is also the problem of the optical lens being too large to provide space for the external filter. This has led to the common problem of protruding lenses on mobile phones, even high-end mobile phones, which increases the risk of bumps and damage. In the trend of miniaturization and thinning of components, the known optical lenses with external near-infrared filters are difficult to make significant progress due to the above limitations.

[0004] In addition, in the process of near-infrared absorption filter, a near-infrared absorption layer is usually formed first and then an anti-reflective coating is applied. However, the working temperature of the coating process for forming the anti-reflective layer is as high as 200°C-300°C, which makes the organic dye in the near-infrared absorption layer easily decompose or lose its activity due to high temperature. Therefore, there are great limitations on the selection of organic dyes and the adjustment and control of coating process parameters. Summary of the invention

[0005] In view of the above problems, the present invention provides a composite photosensitive structure, which includes:

[0006] Photosensitive element; and

[0007] A near infrared absorbing layer is formed on a photosensitive element, wherein the near infrared absorbing layer comprises a copper complex, and the copper complex is formed by a copper compound for providing copper ions, a phosphonic acid as shown in Formula 1 below, and at least one phosphorus-containing compound as shown in Formulas 2 to 4,

[0008]

[0009] wherein R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C 12 Alkyl or C6 to C 12 Aryl,

[0010] The OD value of the near infrared absorption layer to the incident light wavelength of 930nm to 950nm is greater than 4.

[0011] In one embodiment, the photosensitive element is a charged-couple device (CCD) or a complementary metal-oxide-semiconductor (CMOS).

[0012] In one embodiment, the substituted or unsubstituted C1 to C 12 The alkyl group is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl; substituted or unsubstituted C6 to C 12 The aryl group is selected from the group consisting of phenyl, naphthyl and chlorophenyl.

[0013] In one embodiment, the near infrared absorbing layer has a haze of 0.4% or less.

[0014] In one embodiment, the X-ray photoelectron spectrum of the near infrared absorbing layer has at least one main peak at a binding energy of 930 eV to 940 eV. In another embodiment, the counts per second value of at least one main peak in the X-ray photoelectron spectrum of the near infrared absorbing layer is greater than 4500.

[0015] In one embodiment, the near infrared absorbing layer has a thickness of 25 μm to 150 μm.

[0016] In one embodiment, the near infrared absorbing layer further comprises an optical resin, which is a thermoplastic resin and / or a photocurable resin. In another embodiment, the optical resin is selected from polycarbonates, polyesters, polycycloolefins, polyacrylic acids, siloxane resins and polyimides. In another embodiment, the optical resin is methyl methacrylate.

[0017] In one embodiment, a copper compound, a phosphonic acid as shown in Formula 1, and at least one phosphorus-containing compound as shown in Formula 2 to Formula 4 form a dispersion containing a copper complex with a solvent, and the dispersion is mixed with an optical resin in a weight ratio of 5:1 to 1:1 to form a near infrared absorption layer.

[0018] In one embodiment, the photosensitive element includes a plurality of photosensitive regions, the near infrared ray absorption layer is formed on each photosensitive region, and the boundary of the near infrared ray absorption layer is flush with or exceeds the boundary of the photosensitive region.

[0019] In one embodiment, the near infrared ray absorption layer has a first surface and a second surface opposite to each other, wherein the second surface contacts the surface of the photosensitive region, and the first surface is a plane, a convex surface, or a concave surface.

[0020] In one embodiment, the near infrared absorbing layer serves as a microlens.

[0021] The present invention further provides a method for preparing a composite photosensitive structure, which comprises:

[0022] A copper compound for providing copper ions, a phosphonic acid as shown in Formula 1, and at least one phosphorus-containing compound as shown in Formulas 2 to 4 are prepared to form a coating solution containing a copper complex,

[0023]

[0024] wherein R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C 12 Alkyl or C6 to C 12 Aryl;

[0025] Applying the coating liquid on a wafer including a photosensitive element array and curing the coating liquid to form a near infrared ray absorption layer; and

[0026] Cut the wafer to obtain a composite photosensitive structure.

[0027] The absorbance OD value of the near infrared absorption layer to incident light wavelengths of 930nm to 950nm is greater than 4.

[0028] In one embodiment, the photosensitive element is a photocoupled device or a complementary metal oxide semiconductor sensor.

[0029] In one embodiment, the substituted or unsubstituted C1 to C 12 The alkyl group is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl; substituted or unsubstituted C6 to C 12 The aryl group is selected from the group consisting of phenyl, naphthyl and chlorophenyl.

[0030] In one embodiment, the near infrared absorbing layer has a haze of 0.4% or less.

[0031] In one embodiment, the X-ray photoelectron spectrum of the near infrared absorbing layer has at least one main peak at a binding energy of 930 electron volts to 940 electron volts. In another embodiment, the counts per second of at least one main peak in the X-ray photoelectron spectrum of the near infrared absorbing layer is greater than 4500.

[0032] In one embodiment, the near infrared absorbing layer has a thickness of 25 μm to 150 μm.

[0033] In one embodiment, the step of forming a coating solution containing a copper complex comprises adding a copper compound, a phosphonic acid, and a phosphorus-containing compound to a solvent and mixing to form a dispersion. In another embodiment, the weight ratio of the sum of the copper compound, the phosphonic acid, and the phosphorus-containing compound to the solvent is 1:5 to 1:1. In another embodiment, the step of forming a coating solution containing a copper complex further comprises mixing the dispersion with an optical resin to form the coating solution. In another embodiment, the weight ratio of the dispersion to the optical resin is 5:1 to 1:1.

[0034] In one embodiment, the optical resin is a thermoplastic resin and / or a photocurable resin. In another embodiment, the optical resin is selected from polycarbonates, polyesters, polycycloolefins, polyacrylic acids, siloxane resins and polyimides. In another embodiment, the optical resin is methyl methacrylate.

[0035] In one embodiment, the curing step uses light curing, and the coating liquid is dried to remove the solvent before curing.

[0036] In one embodiment, the method for preparing a composite photosensitive structure of the present invention further comprises patterning the near-infrared absorption layer by a photolithography process.

[0037] The present invention first prepares a coating liquid that can form a near-infrared absorption layer that efficiently absorbs incident light with a wavelength of 800nm ​​to 1100nm, more particularly excellently absorbs incident light with a wavelength of 940nm, and at the same time exhibits a high transmittance to visible light, and directly coats it on a photosensitive element to form a near-infrared absorption layer, thereby preparing a composite photosensitive structure. An optical lens using the composite photosensitive structure of the present invention can still achieve an excellent near-infrared cutoff effect without providing an independent external near-infrared filter, and can significantly reduce the thickness of the optical lens. Furthermore, by introducing a photolithography process when forming the near-infrared absorption layer, the near-infrared absorption layer has a specific shape, such as a convex lens or a concave lens, so that the near-infrared absorption layer can also be used as a microlens, further reducing the thickness of the optical lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figures 1 to 4 The figure is a schematic diagram of the process of preparing a composite photosensitive structure according to the present invention.

[0039] Figures 5 to 7 A schematic diagram of another process for preparing a composite photosensitive structure according to the present invention.

[0040] Figure 8 This is the X-ray photoelectron spectrum of the near infrared absorption layer in Preparation Example 1.

[0041] Main component symbols

[0042] 1,1' composite photosensitive structure

[0043] 10 Wafer

[0044] 11 Photosensitive area

[0045] 12 Photosensitive element

[0046] 20 coating liquid

[0047] 21,21',21” Near infrared absorption layer

[0048] C Cutting tools

[0049] L Light source

[0050] M mask. DETAILED DESCRIPTION

[0051] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can easily understand the scope and effectiveness of the present invention based on the contents described herein.

[0052] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents described in the specification for people familiar with this technology to understand and read, and are not used to limit the applicable limiting conditions, so they have no substantial technical significance. Any structural modification, change in proportion relationship, or adjustment of size, without affecting the effects that can be produced and the purposes that can be achieved, should still fall within the scope of the technical content described. At the same time, the terms such as "upper", "first", "second", etc. cited in this specification are only for the convenience of description, and are not used to limit the scope of implementation. Changes or adjustments in their relative relationships should also be considered as the scope of implementation without substantially changing the technical content.

[0053] When “includes,” “comprising,” or “has” specific elements as described herein, unless otherwise stated, other elements, components, structures, regions, parts, devices, systems, steps, or connections may also be included, rather than excluding these other elements.

[0054] Unless clearly stated otherwise herein, the singular forms "a", "an" and "the" described herein also include plural forms, and "or" and "and / or" described herein are used interchangeably.

[0055] The numerical ranges described herein are inclusive and combinable, and any numerical value falling within the numerical range described herein can be used as the maximum value or the minimum value to derive its sub-range; for example, the numerical range of "25 to 200" should be understood to include any sub-range between endpoint 25 and endpoint 200, such as 25 to 150, 30 to 200, 30 to 150... and other sub-ranges; in addition, if a numerical value falls within the ranges described herein (such as between the maximum value and the minimum value), it should be deemed to be included in the scope of the present invention.

[0056] A first aspect of the present invention is a composite photosensitive structure, which includes: a photosensitive element; and a near-infrared absorption layer formed on the photosensitive element.

[0057] As for the photosensitive element, any element that can react with incident light and generate a signal is within the scope of the present invention, including but not limited to a photocoupled device (CCD) or a complementary metal oxide semiconductor (CMOS) sensor.

[0058] Formed on the photosensitive element, specifically, it can refer to the near-infrared absorbing layer directly contacting the photosensitive element, that is, all methods that can make the two directly contact are included in the scope of the present invention, for example, a near-infrared absorbing layer precursor is formed on the surface of the photosensitive element, and then the near-infrared absorbing layer precursor is further processed to become the near-infrared absorbing layer; the near-infrared absorbing layer is attached to the surface of the photosensitive element with or without an adhesive, etc.

[0059] The near infrared absorbing layer of the present invention comprises: a copper complex formed by a copper compound for providing copper ions, a phosphonic acid as shown in Formula 1 and at least one phosphorus-containing compound as shown in Formula 2 to Formula 4,

[0060]

[0061] wherein R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C 12 Alkyl or C6 to C 12 Aryl.

[0062] The copper complex can be chemically represented by Cu 2+ X represents, where Cu 2+ Provided by copper compounds; X is contributed by phosphonic acid and / or phosphorus-containing compounds.

[0063] Alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, etc., and examples of substituted alkyl groups include, but are not limited to, haloalkyl, hydroxyalkyl, nitroalkyl, alkoxyalkyl, etc. Aryl groups include, but are not limited to, phenyl, naphthyl, etc., and examples of substituted aryl groups include, but are not limited to, haloaryl (e.g., chlorophenyl), nitroaryl, hydroxyaryl, alkoxyaryl, alkylaryl, haloalkylaryl, nitroalkylaryl, hydroxyalkylaryl.

[0064] In one embodiment, the phosphonic acid is butylphosphonic acid.

[0065] The copper compound used to provide copper ions is mainly used as a supply source of copper ions. A known copper compound that can provide copper ions can be used, such as a copper salt, which can be listed as copper acetate or a hydrate of copper acetate, and can also be listed as an anhydride or hydrate of copper chloride, copper formate, copper stearate, copper benzoate, copper pyrophosphate, copper naphthenate, and copper citrate. In one embodiment, the copper compound used to provide copper ions is copper acetate.

[0066] The phosphorus-containing compound can have a dispersing function, so that the components in the composition (including the formed copper complex) do not agglomerate with each other and achieve uniform dispersion. One of the effects of this function is that the crystallite size can be less than 100nm, further between 5nm and 80nm, or between 20nm and 60nm, such as 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100nm. When the crystallite size is above 5nm, sufficient near-infrared absorption characteristics can be displayed; and when the crystallite size is below 100nm, the particle number average agglomerated particle size is small, and the product has a lower haze.

[0067] The copper complex of the present invention can be prepared from a near-infrared absorbing composition. The near-infrared absorbing composition includes the above-mentioned copper compound, phosphonic acid and phosphorus-containing compound, and the components interact and react with each other to form a copper complex. In the present invention, the proportion of each component can be adjusted as needed. For example, in the near-infrared absorbing composition, the copper compound used to provide copper ions can be 150 parts by weight, which can be listed as 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145 or 150 parts by weight; the phosphonic acid can be 100 The amount of the phosphorus-containing compound can be 1 to 90 parts by weight, which can be 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 parts by weight; and the total amount of the phosphorus-containing compound can be 1 to 90 parts by weight, which can be 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 parts by weight.

[0068] In one embodiment, the near-infrared absorbing composition includes the phosphorus-containing compounds shown in Formula 2 to Formula 4 at the same time, and the proportion can be adjusted according to the needs. For example, in the near-infrared absorbing composition, the phosphorus-containing compound shown in Formula 2 can be 1 to 90 parts by weight, the phosphorus-containing compound shown in Formula 3 can be 1 to 90 parts by weight, and the phosphorus-containing compound shown in Formula 4 can be 1 to 90 parts by weight, wherein the phosphorus-containing compounds shown in Formula 2 to Formula 4 can be listed as 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 or 90 parts by weight. In another embodiment, the phosphorus-containing compound shown in Formula 2: the phosphorus-containing compound shown in Formula 3: the phosphorus-containing compound shown in Formula 4 is 20:20:50.

[0069] In one embodiment, the near infrared absorbing composition may be in the form of a dispersion, i.e., in addition to the copper compound, phosphonic acid and phosphorus-containing compound, further comprising a solvent. During preparation, the copper compound, phosphonic acid and phosphorus-containing compound may be added to the solvent and mixed, and the ratio of these components to the solvent may be 1:5 to 1:1, for example 1:3, but is not limited thereto.

[0070] The solvent may be a known solvent, including but not limited to water, alcohols, ketones, ethers, esters, aromatic hydrocarbons, halogenated hydrocarbons, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, cyclopentane, etc. Specifically, alcohols include methanol, ethanol, propanol, etc. Esters include alkyl formates, alkyl acetates, alkyl propionates, alkyl butyrates, alkyl lactates, alkyl alkoxy acetates, alkyl 3-alkoxy propionates, alkyl 2-alkoxy propionates, alkyl 2-alkoxy-2-methyl propionates, alkyl pyruvates, alkyl acetoacetates, alkyl 2-oxobutyrates, etc. Examples of ethers include diethylene glycol dimethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, etc. Examples of ketones include methyl ethyl ketone, cyclohexanone, cyclopentanone, 2-heptanone, 3-heptanone, etc. Examples of aromatic hydrocarbons include toluene and xylene, etc.

[0071] Mixing, for example, stirring fully at room temperature (such as 25° C.), for example, stirring for more than 4 hours, more than 6 hours, or more than 8 hours, but not limited thereto.

[0072] In the present invention, the near-infrared absorbing composition in the form of a dispersion liquid can be mixed with an optical resin to form a near-infrared absorbing composition in the form of a coating liquid to subsequently form a near-infrared absorbing layer. The ratio of the dispersion liquid to the optical resin can be 5:1 to 1:1 or 3:1 to 1:1, for example, 0.65:0.35, but is not limited thereto. When the near-infrared absorbing composition in the form of a coating liquid is used, it is formed on a substrate and dried and cured to form a near-infrared absorbing layer.

[0073] The optical resin may be a thermoplastic resin and / or a light-curable resin. In one embodiment, the optical resin is selected from polycarbonates, polyesters, polycycloolefins, polyacrylic acids, siloxane resins, and polyimides. In another embodiment, the optical resin is a siloxane resin. In another embodiment, the optical resin is methyl methacrylate.

[0074] In one embodiment, the near infrared absorbing composition may further add a polymerization initiator, such as a photopolymerization initiator, so that the optical resin can be polymerized by light irradiation. Known polymerization initiators can be used, including but not limited to azobisisobutyronitrile. In one embodiment, a solvent may also be added to facilitate uniform mixing, and known ones may be used, including but not limited to the solvents mentioned herein. In one embodiment, in order to facilitate the curing process, a curing agent, such as a photocuring agent, may be further added, so that the film can be cured by light irradiation.

[0075] In one embodiment, in order to further improve the optical properties of the near infrared absorbing layer, for example, to further enhance the cutoff of near infrared and ultraviolet rays, it may further include an absorbing dye. In one embodiment, the absorbing dye includes a near infrared absorbing dye and / or an ultraviolet absorbing dye.

[0076] Near infrared absorbing dyes such as azo compounds, diimmonium compounds, dithiol metal complexes, squaraine compounds, cyanine compounds and phthalocyanine compounds can adjust the maximum absorption wavelength to between 650 and 1100 nm, or more specifically between 650 and 750 nm. Ultraviolet absorbing dyes such as azomethine compounds, indole compounds, ketone compounds, benzimidazole compounds and triazine compounds.

[0077] In one embodiment, in order to maintain better light transmittance, the near infrared absorption layer has a haze of less than 0.4%, 0.3% or 0.2%, for example, 0.4%, 0.35%, 0.3%, 0.25%, 0.2%, 0.19%, 0.18%, 0.17%, 0.16%, 0.15%, 0.14%, 0.13%, 0.12%, 0.11% or 0.1%.

[0078] The thickness of the near-infrared absorption layer also affects the characteristics of near-infrared absorption. Generally speaking, as the thickness of the near-infrared absorption layer increases, the near-infrared cutoff ability also increases, but it does not meet the demand for thinness. On the other hand, as the thickness of the near-infrared absorption layer decreases, the near-infrared cutoff ability also decreases. In one embodiment, the near-infrared absorbing layer of the present invention can achieve excellent near-infrared cutoff capability even when it is very thin. Specifically, the thickness of the near-infrared absorbing layer is between 25μm and 150μm, between 50μm and 150μm, or between 100μm and 150μm, for example, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 125μm, 130μm, 135μm, 140μm, 145μm, 146μm, 147μm or 150μm.

[0079] In one embodiment, the X-ray photoelectron spectrum of the near infrared absorbing layer of the present invention has at least one main peak at a binding energy of 930 electron volts to 940 electron volts. In one embodiment, the counts per second of the at least one main peak is 4500 or more, 4600 or more, 4700 or more, 4800 or more, 4900 or more, or 5000 or more.

[0080] In one embodiment, the maximum transmittance of the near infrared absorbing layer of the present invention for incident light in the wavelength range of 930 nm to 950 nm (including incident light at 940 nm) is 0.1% or less, less than 0.1%, 0.05% or less, less than 0.05%, 0.01% or less, less than 0.01%, 0.0005 or less, for example, 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.009%, 0.008%, 0.007%, On the other hand, the OD value for an incident light wavelength range of 930nm to 950nm (including an incident light of 940nm) is 3 or more, greater than 3, greater than 3.5, greater than 3.5, greater than 4, greater than 4.5, or greater than 4.5, for example, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9. In one embodiment, the minimum transmittance of the near infrared absorbing layer of the present invention for incident light in the wavelength range of 460nm to 560nm is 80% or more or 85% or more, for example, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89% or 90%.

[0081] In one embodiment, the near infrared absorbing layer has a passband overlapping with a wavelength range of 300nm to 850nm, 300nm to 800nm, or 350nm to 750nm, and the center wavelength of the passband is within a wavelength range of 300nm to 850nm, 300nm to 800nm, 350nm to 750nm, 400nm to 700nm, 450nm to 650nm, 500nm to 600nm, or 500nm to 550nm. Herein, the "passband" refers to a segment in which the transmittance of incident light within the wavelength range is 50% or more, and the "center wavelength of the passband" is the average value of two incident light wavelengths corresponding to the transmittance of 50% for the incident light.

[0082] In one embodiment, when the incident light irradiates the near-infrared absorbing layer of the present invention at an incident angle of 0 and 30 degrees, the central wavelength of the passband is shifted, and the shift amplitude is 1.4 nm or less, such as 1.4 nm, 1.3 nm, 1.2 nm or 1.1 nm. In one embodiment, when the incident light irradiates the near-infrared absorbing layer of the present invention at an incident angle of 0 and 35 degrees, the central wavelength of the passband is shifted, and the shift amplitude is 1.9 nm or less, such as 1.9 nm, 1.8 nm or 1.7 nm.

[0083] In the composite photosensitive structure of the present invention, the photosensitive element may include multiple photosensitive areas, and the near-infrared absorption layer is formed on each photosensitive area. For example, the photosensitive element is a wafer that has not yet been cut, and it has multiple photosensitive units. The photosensitive unit is the photosensitive area referred to in this article, and the near-infrared absorption layer is formed on the entire wafer and can be further processed. More specifically, the near-infrared absorption layer may contact or multiple photosensitive units. In one embodiment, the boundary of the near-infrared absorption layer is flush with or exceeds the boundary of the photosensitive area to ensure that the infrared light is cut off by the near-infrared absorption layer and does not leak into the photosensitive area below.

[0084] In one embodiment, the near-infrared absorption layer of the composite photosensitive structure of the present invention has a relative first surface and a second surface, wherein the second surface of the near-infrared absorption layer contacts the surface of the photosensitive area, and the first surface of the near-infrared absorption layer is a plane, a convex surface, or a concave surface. Here, the near-infrared absorption layer may be processed to make the first surface a plane, a convex surface, or a concave surface, for example, by etching, laser cutting, grinding, photolithography, etc., and the processing may be performed before, at the same time, or after the near-infrared absorption layer is formed on the photosensitive area. A convex surface means that the first surface protrudes outward relative to the second surface; a concave surface means that the first surface is sunken inward relative to the second surface. In one embodiment, the first surface of the near-infrared absorption layer serves as the incident surface of light, so that the light is converged or diverged due to the first surface, so that the near-infrared absorption layer serves as a microlens.

[0085] A second aspect of the present invention is a method for preparing a composite photosensitive structure, comprising:

[0086] A copper compound for providing copper ions, a phosphonic acid as shown in Formula 1, and at least one phosphorus-containing compound as shown in Formulas 2 to 4 are prepared to form a coating solution containing a copper complex,

[0087]

[0088] wherein R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C 12 Alkyl or C6 to C 12 Aryl;

[0089] Applying the coating liquid on a wafer including a photosensitive element array and curing the coating liquid to form a near infrared ray absorption layer; and

[0090] The wafer is cut to obtain a composite photosensitive structure.

[0091] Specific implementation method Figures 1 to 4As exemplified. First, a copper compound, a phosphonic acid, and a phosphorus-containing compound for providing copper ions are prepared, and then mixed with a solvent to form a dispersion. The mixing here, for example, can firstly mix the copper compound and the solvent into a first mixture, and then mix the phosphorus-containing compound and the solvent into a second mixture, and then mix the first mixture and the second mixture with the phosphonic acid to form a dispersion. Here, due to the reaction and interaction of each component, a copper complex is formed in the dispersion.

[0092] To form a coating solution, the dispersion is further mixed with an optical resin, i.e., the optical resin as described in the first aspect of this document.

[0093] In one embodiment, the dispersion is first dried to form a powder, and then the powder is added to a second solvent to form a dispersion, which is then mixed with the optical resin. The second solvent may be selected from the solvent types described in the first aspect of this invention.

[0094] In the case of adding an absorbing dye, the absorbing dye can also be optionally added to the dispersion / coating solution, for example, added to the dispersion before mixing with the optical resin, mixed with the optical resin together with the dispersion, or added to the coating solution after the dispersion is mixed with the optical resin.

[0095] like Figure 1 As shown, the coating liquid 20 is coated on the wafer 10 including the photosensitive element array (including multiple photosensitive areas 11). Optionally, before or after coating, the coating liquid is de-bubbled, for example, by ultrasonic vibration, placing in a negative pressure environment, or both. Coating is not limited in the present invention, for example, it can be coated by spin coating, spray coating, blade coating, roller coating, dipping, etc.

[0096] Then, the coating liquid is cured to form a near infrared absorbing layer. Figure 2 As shown in the example, the curing may be light curing, where the coating liquid is irradiated with a light source L to form a near infrared absorbing layer 21 on the entire wafer 10 .

[0097] For example Figure 3 and Figure 4 As shown, a cutting tool C, such as a laser or a diamond knife, is used to cut the wafer 10 to obtain a composite photosensitive structure 1 having a photosensitive element 12 and a near-infrared absorption layer 21 formed thereon.

[0098] Figures 5 to 7 To show another specific embodiment of the method for preparing a composite photosensitive structure, compared to Figures 1 to 4 A step of patterning the near-infrared absorbing layer is added. Figures 5 to 7 The process shown is continued in Figure 1 Afterwards, they correspond to Figures 2 to 4 , the difference is that, compared with Figure 2 , Figure 5A photolithography process is further introduced, which specifically includes setting a mask M, such as a grayscale mask, so that the coating liquid below is selectively exposed to obtain a near-infrared absorbing layer 21', 21". The specific pattern or shape is as follows: Figure 6 and Figure 7 As illustrated, the first surface of the near infrared absorbing layer may be made to protrude upward or to be recessed downward.

[0099] In one embodiment, the coating liquid on the entire wafer forms independent patterned near-infrared absorption layers above the positions corresponding to the photosensitive regions 11, such as Figure 6 and Figure 7 The near infrared absorbing layers 21 ′, 21 ″ shown are independent of each other, which specifically means that there is no contact between any two adjacent infrared absorbing layers, which can be achieved through the above-mentioned photolithography process.

[0100] In one embodiment, the coating solution is dried (eg, dried at 120° C.) to remove the solvent before curing.

[0101] The present invention will be described in further detail with reference to the following specific examples, which are however in no way intended to limit the scope of the present invention.

[0102] Preparation Example 1 - Near Infrared Absorption Layer

[0103] 150 parts by weight of copper acetate was mixed with 15,000 parts by weight of ethanol and stirred at room temperature for 1.5 hours to form a first mixed solution; 20 parts by weight of the phosphorus-containing compound shown in formula 2 (plysurf A242G, purchased from Japan Daiichi Industry Pharmaceutical Co., Ltd.), 20 parts by weight of the phosphorus-containing compound shown in formula 3 (plysurf W542C, purchased from Japan Daiichi Industry Pharmaceutical Co., Ltd.) and 50 parts by weight of the phosphorus-containing compound shown in formula 4 (plysurf A285C, purchased from Japan Daiichi Industry Pharmaceutical Co., Ltd.) were mixed with 1,500 parts by weight of ethanol to form a second mixed solution. The first mixed solution and the second mixed solution were mixed and stirred at room temperature for 1 hour, followed by adding 100 parts by weight of butylphosphonic acid and stirring at room temperature for 3 hours. Then, the mixture was placed in an oven at 85°C for 12 hours to obtain a powder. The powder and xylene were mixed in a weight ratio of 1:3 to form a dispersion, and the dispersion was mixed with methyl methacrylate (MMA) in a weight ratio of 0.65:0.35 to form a coating solution, which was then coated on a substrate and baked at 70°C for 30 minutes to obtain a near-infrared absorption layer.

[0104] The near infrared absorption layer is subjected to X-ray photoelectron (ESCA / XPS) analysis, and its X-ray photoelectron spectrum is as follows: Figure 5It can be observed that the characteristic peaks associated with copper complexes (Cu(PO x ) y , CuO, Cu2O, Cu(OH)2). In addition, the peak that appears when the binding energy is above 940 eV is a satellite peak.

[0105] Example 1

[0106] The dispersion and coating liquid were prepared according to the method of Preparation Example 1, but 0.5 g of azobisisobutyronitrile (AIBN) as a photopolymerization initiator and an appropriate amount of solvent propylene glycol methyl ether (PGME) were added to the coating liquid, and then the bubbles were removed by ultrasonic vibration under negative pressure, and then spin-coated on the wafer with the photosensitive element array. The solvent was baked at a temperature of 120°C, and then the coating layer was irradiated with ultraviolet light to form a near-infrared absorption layer on the surface of the photosensitive element array. Finally, the wafer was cut by laser to obtain a composite photosensitive structure.

[0107] Example 2

[0108] According to Example 1, a near-infrared absorption layer is formed on a wafer having a photosensitive element array, except that a grayscale mask is placed above the wafer after the spin coating step and before the ultraviolet irradiation, so that the coating layer is selectively exposed. Thus, a patterned near-infrared absorption layer is formed on the surface of the photosensitive element array to obtain a composite photosensitive structure.

[0109] The above-mentioned embodiments and specific examples are not intended to limit the present invention. The listed technical features or schemes can be combined with each other. The present invention can also be implemented or applied through other different embodiments. The details recorded in this document can also be given different changes or modifications according to different viewpoints and applications without departing from the present invention.

Claims

1. A composite photosensitive structure, characterized in that: include: Photosensitive element; as well as A near infrared absorbing layer is formed on the photosensitive element, wherein the near infrared absorbing layer comprises a copper complex, and the copper complex is formed by a copper compound for providing copper ions, a phosphonic acid as shown in Formula 1, and at least one phosphorus-containing compound as shown in Formulas 2 to 4, wherein R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C 12 Alkyl or C6 to C 12 Aryl, Wherein, the OD value of the near infrared absorption layer to the incident light wavelength of 930nm to 950nm is greater than 4.

2. The composite photosensitive structure according to claim 1, characterized in that: The photosensitive element is a photosensitive coupling element or a complementary metal oxide semiconductor sensor.

3. The composite photosensitive structure according to claim 1, characterized in that: The substituted or unsubstituted C1 to C 12 The alkyl group is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl; the substituted or unsubstituted C6 to C 12 The aryl group is selected from the group consisting of phenyl, naphthyl and chlorophenyl.

4. The composite photosensitive structure according to claim 1, characterized in that: The near infrared absorbing layer has a haze of 0.4% or less.

5. The composite photosensitive structure according to claim 1, characterized in that: The X-ray photoelectron spectrum of the near infrared absorption layer has at least one main peak when the binding energy is 930 electron volts to 940 electron volts.

6. The composite photosensitive structure according to claim 5, characterized in that: The counts per second of the at least one main peak is greater than 4500.

7. The composite photosensitive structure according to claim 1, characterized in that: The near infrared absorbing layer has a thickness of 25 μm to 150 μm.

8. The composite photosensitive structure according to claim 1, characterized in that: The photosensitive element includes a plurality of photosensitive areas, the near infrared ray absorption layer is formed on each of the photosensitive areas, and the boundary of the near infrared ray absorption layer is flush with or exceeds the boundary of the photosensitive area.

9. The composite photosensitive structure according to claim 1, characterized in that: The near infrared ray absorption layer has a first surface and a second surface opposite to each other, the second surface contacts the surface of the photosensitive area, and the first surface is a plane, a convex surface or a concave surface.

10. The composite photosensitive structure according to claim 9, characterized in that: The near infrared absorbing layer acts as a microlens.

11. A method for preparing a composite photosensitive structure, characterized in that: include: A copper compound for providing copper ions, a phosphonic acid as shown in Formula 1 and at least one phosphorus-containing compound as shown in Formula 2 to Formula 4 are prepared to form a coating liquid containing a copper complex, wherein R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C 12 Alkyl or C6 to C 12 Aryl; Applying the coating liquid on a wafer including a photosensitive element array and curing the coating liquid to form a near infrared ray absorption layer; and cutting the wafer to obtain a composite photosensitive structure, The absorbance OD value of the near-infrared absorption layer to incident light wavelengths of 930nm to 950nm is greater than 4.

12. The method according to claim 11, characterized in that The photosensitive element is a photosensitive coupling element or a complementary metal oxide semiconductor sensor.

13. The method according to claim 11, characterized in that The substituted or unsubstituted C1 to C 12 The alkyl group is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl; the substituted or unsubstituted C6 to C 12 The aryl group is selected from the group consisting of phenyl, naphthyl and chlorophenyl.

14. The method according to claim 11, characterized in that The near infrared absorbing layer has a haze of 0.4% or less.

15. The method according to claim 11, characterized in that The X-ray photoelectron spectrum of the near infrared absorption layer has at least one main peak when the binding energy is 930 electron volts to 940 electron volts.

16. The method according to claim 15, characterized in that The counts per second of the at least one main peak is greater than 4500.

17. The method according to claim 16, characterized in that The near infrared absorbing layer has a thickness of 25 μm to 150 μm.

18. The method according to claim 11, characterized in that The curing is photocuring, and the coating liquid is dried to remove the solvent before curing.

19. The method according to claim 11, characterized in that The method further includes patterning the near infrared ray absorption layer by a photolithography process.

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