JP7275605B2 - Filter for solid-state image sensor, solid-state image sensor, method for manufacturing filter for solid-state image sensor, and method for manufacturing solid-state image sensor - Google Patents

Description

The present invention relates to a filter for a solid-state imaging device, a solid-state imaging device provided with the filter for a solid-state imaging device, a method for manufacturing a filter for a solid-state imaging device, and a method for manufacturing a solid-state imaging device.

A solid-state imaging device such as a CMOS image sensor or a CCD image sensor has a photoelectric conversion device that converts the intensity of light into an electrical signal. In addition to multiple photoelectric conversion elements, the solid-state image sensor is equipped with color filters positioned on the photoelectric conversion elements for each color. and a positioned infrared pass filter (see, for example, US Pat.

The color filter converts the color of the received light into a three primary color system of light consisting of red, green and blue or a three primary color system of colors consisting of cyan, magenta and yellow. The photoelectric conversion element for each color converts the intensity of light of each color converted by the color filter into an electric signal.

The infrared pass filter shields visible light that can be detected by the infrared photoelectric conversion element to increase the detection accuracy of infrared light by the infrared photoelectric conversion element. In the constituent material of the infrared pass filter, for example, as described in Patent Document 1, at least one of pigments and dyes, a single compound or a combination of a plurality of compounds, is used to form a colored composition for an infrared pass filter. be a thing Alternatively, as described in Patent Document 2, a black colorant such as a bisbenzofuranone-based pigment, an azomethine-based pigment, a perylene-based pigment, or an azo-based dye is used as a coloring composition for an infrared pass filter. Alternatively, as described in Patent Document 3, a combination of a black colorant and color pigments such as red, blue, green and yellow is known.

JP 2014-130338 A JP 2014-130173 A JP 2016-177079 A

A solid-state imaging device comprising a color filter and an infrared pass filter enables visible light detection and infrared light detection, while the manufacturing methods described in Patent Documents 1 to 3 can detect visible light and red light. Ambient light detection and are manufactured from separate materials of construction. The use of different constituent materials for manufacturing complicates the manufacturing process and the use process of the solid-state imaging device, leading to problems such as a decrease in yield and an increase in cost.

An object of the present invention is to provide a filter for a solid-state imaging device, a solid-state imaging device, a method for manufacturing a filter for a solid-state imaging device, and a method for manufacturing a solid-state imaging device, which can suppress a decrease in the rate of non-defective products and an increase in cost. is.

A filter for a solid-state image pickup device for solving the above problems includes three color filters of a red filter, a green filter, and a blue filter positioned on the light incident side with respect to the first photoelectric conversion element, and a second photoelectric conversion element. and an infrared pass filter positioned on the light incident side with respect to the conversion element, wherein the infrared pass filter is a laminate of filter elements of two or more colors including at least red and blue, and the filters of each color. The element is thinner than the color filter of the same color as the filter element and is composed of the same material as the color filter.

According to the above configuration, the two or more color filter elements forming the infrared pass filter and the corresponding two or more color filters are made of the same material. Therefore, it is possible to suppress the difference depending on the constituent materials between the processing conditions suitable for the color filter and the processing conditions suitable for the infrared pass filter. In addition, it is possible to suppress the difference depending on the constituent materials between the use environment suitable for the color filter and the use environment suitable for the infrared pass filter. As a result, it is possible to suppress a decrease in the non-defective product rate and an increase in cost due to differences in processing conditions and differences in usage environment.

In the solid-state imaging device filter, the infrared pass filter further includes a green filter element, and the green filter element is thinner than the color filter having the same color as the filter element, and is the same as the color filter. They may be constructed from the same material. With this configuration, it is possible to suppress the above-described difference in processing conditions and difference in use environment even in a filter for a solid-state image pickup device having a green filter element.

In the solid-state imaging device filter, the thickness of the infrared pass filter may be equal to or greater than the thickness of the color filter. With this configuration, it is possible to reduce the restrictions on the thinning of each filter element, so that it is possible to improve the non-transmittance of visible light in the infrared pass filter.

The solid-state imaging device filter may further include an infrared cut filter located on the light incident side with respect to the first photoelectric conversion device. With this configuration, the detection accuracy of visible light by the first photoelectric conversion element is enhanced, and the step between the infrared pass filter and the color filter can be reduced by the infrared cut filter. In addition, an infrared cut filter positioned on the light incident side with respect to the second photoelectric conversion element may be provided.

In the solid-state imaging device filter, a through hole may be provided at a position of the infrared cut filter corresponding to the infrared pass filter. With this configuration, it is possible to detect the infrared light cut by the infrared cut filter with the second photoelectric conversion element.

A solid-state imaging device for solving the above problems includes a photoelectric conversion element and the solid-state imaging device filter.
A method for manufacturing a filter for a solid-state image pickup device for solving the above-mentioned problems includes three color filters positioned on the light incident side with respect to the first photoelectric conversion element, and three color filters positioned on the light incident side with respect to the second photoelectric conversion element. and an infrared pass filter positioned in the solid-state imaging device filter, wherein the infrared pass filter is a laminate of filter elements of two or more colors including at least red and blue, each color The filter element of is thinner than the color filter of the same color as the filter element and is made of the same material as the color filter, and the color filter of each color is formed in separate steps, and the color filter of each color is formed in separate steps. A color filter and the filter element having the same color as the color filter are formed in the same process.

According to the above method, the two or more color filter elements forming the infrared pass filter and the corresponding two or more color filters are formed from the same material. Therefore, it is possible to suppress the difference depending on the constituent materials between the processing conditions suitable for the color filter and the processing conditions suitable for the infrared pass filter. In addition, it is possible to suppress the difference depending on the constituent materials between the use environment suitable for the color filter and the use environment suitable for the infrared pass filter. Moreover, since the color filters of each color and the filter elements of the same color as the color filters are formed in the same process, it is possible to improve the productivity of filters for solid-state imaging devices.

A method for manufacturing a solid-state imaging device for solving the above-mentioned problems includes a step of forming a photoelectric conversion device, and a solid-state imaging device on a light incident side of the photoelectric conversion device using the above-described method for manufacturing a filter for a solid-state imaging device. form a filter for

1 is an exploded perspective view partially showing a layer structure in an embodiment of a solid-state imaging device; FIG. II-II line cross-sectional view of FIG. The graph which shows an example of the transmission spectrum of an infrared pass filter. (a), (b), and (c) are cross-sectional views showing respective steps in one embodiment of the solid-state imaging device. FIG. 11 is an exploded perspective view partially showing a layer structure in a modification of the solid-state imaging device; FIG. 5 is a sectional view taken along the line VI-VI.

An embodiment of a filter for a solid-state imaging device, a solid-state imaging device, a method for manufacturing a filter for a solid-state imaging device, and a method for manufacturing a solid-state imaging device will be described below with reference to FIGS. 1 to 4. FIG. FIG. 1 is a schematic configuration diagram separately showing each layer in a part of a solid-state imaging device.

As shown in FIG. 1 , the solid-state imaging device includes a solid-state imaging device filter 10 and a plurality of photoelectric conversion elements 11 . The solid-state imaging device filter 10 includes color filters 12R, 12G, 12B, an infrared pass filter 12P, and microlenses 15R, 15G, 15B, 15P.

The respective color filters 12R, 12G, 12B are positioned between the three-color photoelectric conversion elements 11R, 11G, 11B and the microlenses 15R, 15G, 15B. The infrared pass filter 12P is positioned between the infrared photoelectric conversion element 11P and the microlens 15P.

The photoelectric conversion element 11 for three colors is an example of a first photoelectric conversion element, and is composed of a photoelectric conversion element 11R for red, a photoelectric conversion element 11G for green, and a photoelectric conversion element 11B for blue. The infrared photoelectric conversion element 11P is an example of a second photoelectric conversion element. The solid-state imaging device includes a plurality of red photoelectric conversion elements 11R, a plurality of green photoelectric conversion elements 11G, a plurality of blue photoelectric conversion elements 11B, and a plurality of infrared photoelectric conversion elements 11P. FIG. 1 shows a repeating unit of photoelectric conversion elements 11 in a solid-state imaging device.

The color filters for three colors are composed of a red filter 12R, a green filter 12G, and a blue filter 12B. The red filter 12R is positioned on the light incident side with respect to the red photoelectric conversion element 11R. The green filter 12G is positioned on the light incident side with respect to the green photoelectric conversion element 11G. The blue filter 12B is located on the light incident side with respect to the blue photoelectric conversion element 11B.

As the pigment contained in the photosensitive coloring composition of the red filter 12R, the green filter 12G, and the blue filter 12B, organic or inorganic pigments can be used singly or in combination of two or more. . As the pigment, a pigment having high color developability and high heat resistance, particularly a pigment having high heat decomposition resistance is preferable, and an organic pigment is used. Organic pigments include phthalocyanine, azo, anthraquinone, quinacridone, dioxazine, anthanthrone, indanthrone, perylene, thioindigo, isoindoline, quinophthalone, and diketopyrrolopyrrole pigments. are mentioned.

Specific examples of organic pigments that can be used in the photosensitive coloring composition of the present embodiment are shown below by color index numbers.
Examples of blue pigments used in the blue-sensitive coloring composition for each color filter include CI Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 22, 60, 64, 81, among others, CI Pigment Blue 15:6 is preferred. Examples of purple dyes include pigments such as CI Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, and 50, among which CI Pigment Violet 23 is preferred.

Yellow pigments include C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35, 35:1, 36, 36:1, 37, 37:1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 138, 139, 147, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, Pigment Yellow 13, 150 and 185 are particularly preferred.

The red photosensitive coloring composition is, for example, C.I. Pigment Red 7,9,14,41,48:1,48:2,48:3,48:4,81:1,81: 2, 81: 3, 97, 122, 123, 146, 149, 168, 177, 178, 180, 184, 185, 187, 192, 200, 202, 208, 210, 215, 216, 217, 220, 223, Red pigments such as 224, 226, 227, 228, 240, 246, 254, 255, 264, 272, C.I. as C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35, 35: 1, 36, 36 : 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 93, 94, 95, 97, 98, 100 , 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 138, 139, 147, 150, 151, 152 , 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 185, 187 , 188, 193, 194, 198, 199, 213, 214, etc.

In addition, the green photosensitive coloring composition is obtained by using a green pigment such as C.I. Pigment Green 7, 10, 367, 58, and, if necessary, the above yellow pigment for toning instead of a blue pigment or the like. It is a composition that can be

The photosensitive coloring composition of each color further contains a binder resin, a photopolymerization initiator, a polymerizable monomer, an organic solvent, a leveling agent and the like. Examples of binder resins include acrylic resins, polyamide resins, polyimide resins, polyurethane resins, polyester resins, polyether resins, polyolefin resins, polycarbonate resins, polystyrene resins, and norbornene resins.

Examples of photopolymerization initiators include acetophenone-based photopolymerization initiators, benzoin photopolymerization initiators, benzophenone-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, triazine-based photopolymerization initiators, and oxime ester-based photopolymerization initiators. and the like are used singly or in combination of two or more.

Polymerizable monomers include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert- Butyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, cyclohexyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isobornyl (meth)acrylate, 2-hydroxyethyl ( (meth)acrylic acid esters such as meth)acrylate and tetrahydrofurfuryl (meth)acrylate; N-vinylpyrrolidone; styrene and its derivatives, α-methylstyrene and other styrenes; (meth)acrylamide, methylol (meth)acrylamide , alkoxymethylol (meth)acrylamide, diacetone (meth)acrylamide and other acrylamides; (meth)acrylonitrile, ethylene, propylene, butylene, vinyl chloride, vinyl acetate and other vinyl compounds, and polymethyl methacrylate macromonomers, polystyrene macromonomers Examples include macromonomers such as monomers. These monomers can be used singly or in combination of two or more.

Examples of organic solvents include ethyl lactate, benzyl alcohol, 1,2,3-trichloropropane, 1,3-butanediol, 1,3-butylene glycol, 1,3-butylene glycol diacetate, and 1,4-dioxane. , 2-heptanone, 2-methyl-1,3-propanediol, 3,5,5-trimethyl-2-cyclohexen-1-one, 3,3,5-trimethylcyclohexanone, ethyl 3-ethoxypropionate, 3- methyl-1,3-butanediol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-3-methylbutyl acetate, 3-methoxybutanol, 3-methoxybutyl acetate, 4-heptanone, m-xylene, m-diethylbenzene, m-dichlorobenzene, N,N-dimethylacetamide, N,N-dimethylformamide, n-butyl alcohol, n-butylbenzene, n-propyl acetate, o-xylene, o-chlorotoluene, o-diethylbenzene , o-dichlorobenzene, p-chlorotoluene, p-diethylbenzene, sec-butylbenzene, tert-butylbenzene, γ-butyrolactone, isobutyl alcohol, isophorone, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monoisopropyl ether, Ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monotertiary butyl ether, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monopropyl ether, ethylene glycol monohexyl ether, ethylene glycol monomethyl ether, ethylene glycol Monomethyl ether acetate, diisobutyl ketone, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether, cyclohexanol, cyclohexanol acetate, cyclohexanone, dipropylene glycol Dimethyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monomethyl ether, diacetone alcohol, triacetin, tripropylene glycol monobutyl ether, tripropylene glycol Monomethyl ether, propylene glycol diacetate, propylene glycol phenyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, benzyl alcohol, methyl isobutyl ketone, methylcyclohexanol, n-amyl acetate, n-butyl acetate, isoamyl acetate, isobutyl acetate, propyl acetate, dibasic esters and the like. These can be used individually by 1 type or in mixture of 2 or more types.

As the leveling agent, dimethylsiloxane having a polyether structure or a polyester structure in its main chain is preferred. Specific examples of dimethylsiloxane having a polyether structure in the main chain include FZ-2122 manufactured by Dow Corning Toray Co., Ltd. and BYK-333 manufactured by BYK Chemie. Specific examples of dimethylsiloxane having a polyester structure include BYK-310 and BYK-370 manufactured by BYK-Chemie. A dimethylsiloxane having a polyether structure and a dimethylsiloxane having a polyester structure can be used in combination. These can be used individually by 1 type or in mixture of 2 or more types.

The infrared pass filter 12P includes at least a first pass element 12P1 and a third pass element 12P3. Also, as shown in FIG. 2, a second path element 12P2 may be further provided. First pass element 12P1, second pass element 12P2, and third pass element 12P3 are examples of three-color filter elements. A case will be described below in which the infrared pass filter 12P includes three color filter elements, a first pass element 12P1, a second pass element 12P2, and a third pass element 12P3.

The infrared pass filter 12P is a laminate of three color filter elements. Each color filter element is thinner than the color filter of the same color as the filter element and is made of the same material as the color filter. That is, the first pass element 12P1 is thinner than the red filter 12R and made of the same material as the red filter 12R. The second pass element 12P2 is thinner than the green filter 12G and made of the same material as the green filter 12G. The third pass element 12P3 is thinner than the blue filter 12B and made of the same material as the blue filter 12B.

The stacking order of the first path element 12P1, the second path element 12P2, and the third path element 12P3 may be the order of the first path element 12P1, the second path element 12P2, and the third path element 12P3. The order may be the element 12P1, the third path element 12P3, and the second path element 12P2. Also, the stacking order of the first path element 12P1, the second path element 12P2, and the third path element 12P3 may be the order of the second path element 12P2, the first path element 12P1, and the third path element 12P3. The order may be the element 12P2, the third path element 12P3, and the first path element 12P1. Also, the stacking order of the first pass element 12P1, the second pass element 12P2, and the third pass element 12P3 may be the order of the third pass element 12P3, the first pass element 12P1, and the second pass element 12P2. The order may be the element 12P3, the second path element 12P2, and the first path element 12P1.

The infrared pass filter 12P cuts visible light that can be detected by the infrared photoelectric conversion element 11P to the infrared photoelectric conversion element 11P, thereby enhancing detection accuracy of visible light by the infrared photoelectric conversion element 11P. Visible light that can be detected by the infrared photoelectric conversion element 11P is, for example, light having a wavelength of 450 nm or more and 700 nm or less. The infrared pass filter 12P is a layer located only on the infrared photoelectric conversion element 11P.

As shown in FIG. 3, the transmission spectrum of the infrared pass filter 12P exhibits a transmittance of 10% or less in the range of 400 nm or more and 700 nm or less, for example. On the other hand, the infrared pass filter 12P has, for example, a transmittance of 10% or more with a peak around 900 nm, and a transmittance of 90% or more in the range exceeding 900 nm.

Near-infrared light with a wavelength of 850 nm and near-infrared light with a wavelength of 940 nm are absorbed by water vapor contained in the atmosphere. That is, near-infrared light with a wavelength of 850 nm and near-infrared light with a wavelength of 940 nm are light from which noise due to sunlight is removed by water vapor in the atmosphere. The infrared photoelectric conversion element 11P detects at least one of near-infrared light with a wavelength of 850 nm and near-infrared light with a wavelength of 940 nm.

The microlenses are composed of a red microlens 15R, a green microlens 15G, a blue microlens 15B, and an infrared microlens 15P. The red microlens 15R is positioned on the light incident side with respect to the red filter 12R. The green microlens 15G is positioned on the light incident side with respect to the green filter 12G. The blue microlens 15B is positioned on the light incident side with respect to the blue filter 12B. The infrared microlens 15P is positioned on the light incident side with respect to the infrared pass filter 12P.

Each microlens 15R, 15G, 15B, 15P has an incident surface 15S which is an outer surface. Each of the microlenses 15R, 15G, 15B and 15P has a refractive index difference with the outside air for concentrating the light entering the incident surface 15S toward each of the photoelectric conversion elements 11R, 11G, 11B and 11P.

Next, a method for manufacturing a filter for a solid-state image sensor and a method for manufacturing a solid-state image sensor will be described. A method for manufacturing a solid-state image sensor includes a step of forming each photoelectric conversion element 11 and a method for manufacturing a filter for a solid-state image sensor.

The method for manufacturing a filter for a solid-state imaging device includes a first step of forming a red filter 12R and a first pass element 12P1 having the same color as the red filter 12R. Moreover, the method for manufacturing a filter for a solid-state imaging device includes a second step of forming a green filter 12G and a second pass element 12P2 having the same color as the green filter 12G. Further, the method for manufacturing a filter for a solid-state imaging device includes a third step of forming a blue filter 12B and a third pass element 12P3 having the same color as the blue filter 12B. The method for manufacturing a filter for a solid-state imaging device includes a fourth step of forming each microlens 15R, 15G, 15B, 15P.

As shown in FIG. 4A, in the first step, a coating film 12RD containing a red photosensitive resin is formed on each photoelectric conversion element 11, and the coating film 12RD is patterned using a photolithography method to A red filter 12R and a first pass element 12P1 are formed.

For example, the coating film 12RD containing the red photosensitive resin is formed by applying a coating liquid containing the red photosensitive resin and drying the coating film 12RD. The red filter 12R is formed by exposing and developing the coating film 12RD to a range corresponding to the region of the red filter 12R. Also, the first pass element 12P1 uses a halftone mask or a gradation mask at the time of exposure for forming the red filter 12R, and exposes a range corresponding to the region of the first pass element 12P1, and It is formed by developing. The coating film 12RD located on the green photoelectric conversion element 11G and the blue photoelectric conversion element 11B is removed by the above-described exposure and development.

As shown in FIG. 4B, in the second step, the red filter 12R and the first pass element 12P1, the green photoelectric conversion element 11G, and the blue photoelectric conversion element 11B have , a coating film 12GD containing a green photosensitive resin is formed, and a green filter 12G and a second pass element 12P2 are formed by patterning the coating film 12GD using a photolithography method.

For example, the coating film 12GD containing the photosensitive resin for green is formed by applying a coating liquid containing the photosensitive resin for green and drying the coating film 12GD. The green filter 12G is formed by exposing a range corresponding to the area of the green filter 12G and developing the coating film 12GD. Also, the second pass element 12P2 uses a halftone mask or a gradation mask at the time of exposure for forming the green filter 12G, and exposes a range corresponding to the region of the second pass element 12P2, and It is formed by developing. The blue photoelectric conversion element 11B and the coating film 12GD located on the red filter 12R are removed by the above-described exposure and development.

As shown in FIG. 4C, in the third step, a coating film 12BD containing a blue photosensitive resin is formed on the red filter 12R, the green filter 12G, and the second pass element 12P2, followed by photolithography. A blue filter 12B and a third pass element 12P3 are formed by patterning the coating film 12BD using a method.

For example, the coating film 12BD containing the blue photosensitive resin is formed by applying a coating liquid containing the blue photosensitive resin and drying the coating film 12BD. The blue filter 12B is formed by exposing and developing the coating film 12BD to a range corresponding to the region of the blue filter 12B. Further, the third pass element 12P3 uses a halftone mask or a gradation mask at the time of exposure for forming the blue filter 12B, and exposes a range corresponding to the region of the third pass element 12P3, and It is formed by developing. Note that the coating film 12BD located on the red filter 12R and the green filter 12G is removed by the above-described exposure and development.

In the fourth step, a coating film containing a transparent resin is formed on the color filters 12R, 12G, 12B and the infrared pass filter 12P. Then, the coating film made of transparent resin is subjected to patterning using photolithography and reflowing by heat treatment to form the respective microlenses 15R, 15G, 15B, and 15P. Examples of transparent resins include acrylic resins, polyamide resins, polyimide resins, polyurethane resins, polyester resins, polyether resins, polyolefin resins, polycarbonate resins, polystyrene resins, and norbornene resins.

In addition, the function of transmitting infrared light by the infrared pass filter 12P may change according to the thickness of the infrared pass filter 12P. The microlenses 15R, 15G, 15B on the color filters 12R, 12G, 12B and the microlens 15P on the infrared pass filter 12P are the color filters 12R, 12G, 12B and the infrared pass filter 12P. A step in between can reduce the accuracy of the machining. Therefore, from the viewpoint of improving the flatness of the base of each microlens 15R, 15G, 15B, 15P, the thickness of each color filter 12R, 12G, 12B and the thickness of the infrared pass filter 12P are substantially equal to each other. is preferred.

Alternatively, it is also possible to adopt a configuration in which a flattening layer is provided between each color filter 12R, 12G, 12B and infrared pass filter 12P and the microlens 15P. If the configuration includes a flattening layer, the thickness difference between the color filters 12R, 12G, 12B and the infrared pass filter 12P is reduced, thereby flattening the base of the microlenses 15R, 15G, 15B, 15P. can.

Further, the material of the microlenses 15R, 15G, 15B and 15P may be used instead of the planarizing layer when forming the respective microlenses 15R, 15G, 15B and 15P. The height difference due to the difference in thickness of the filters 12R, 12G, 12B for each color and the infrared pass filter 12P may be flattened by filling the material of the microlenses 15R, 15G, 15B, 15P.

As described above, according to the above embodiment, the following effects can be obtained.
(1) Each of the three-color pass elements 12P1, 12P2, and 12P3 and the three-color color filters are made of the same material. Therefore, it is possible to suppress the difference depending on the constituent materials between the processing conditions suitable for the color filter and the processing conditions suitable for the infrared pass filter 12P.

(2) It is possible to suppress the difference depending on the constituent materials between the use environment suitable for each color filter 12R, 12G, 12B and the use environment suitable for the infrared pass filter 12P.

(3) For a solid-state imaging device equipped with an infrared sensor function, since the filters 12R, 12G, 12B for each color and the pass elements 12P1, 12P2, 12P3 of the same color as the filters for the respective colors are formed in the same process. It becomes possible to manufacture without lowering the productivity of the filter.

(4) Moreover, the coating films 12RD, 12GD and 12BD for forming the color filters 12R, 12G and 12B and the coating films 12RD, 12GD and 12BD for forming the pass elements 12P1, 12P2 and 12P3 are Formed as a single coating. Therefore, it is also possible to more effectively use the materials required for forming the filters 12R, 12G, 12B for each color and the infrared pass filter 12P.

It should be noted that the above embodiment can be implemented with the following changes.
[Infrared cut filter]
- The solid-state imaging device can also be provided with an infrared cut filter 13 separately. The infrared cut filter 13 cuts the photoelectric conversion element 11 from infrared light in a wavelength band that can be detected as noise by each photoelectric conversion element 11 . Thereby, the detection accuracy of the photoelectric conversion element 11 is enhanced.

For example, as shown in FIG. 5, the infrared cut filter 13 may be provided with a through hole 13H on the light incident side of the infrared pass filter 12P and not positioned on the light incident side of the infrared pass filter 12P. good. The infrared cut filter 13 is common to the red filter 12R, the green filter 12G, and the blue filter 12B.

Infrared light that can be detected by each photoelectric conversion element 11 is, for example, near-infrared light having a wavelength of 700 nm or more and 1200 nm or less. The infrared cut filter 13 is a layer common to the red filter 12R, the green filter 12G, and the blue filter 12B.

Further, the infrared cut filter 13 may be provided so as to be positioned on the light incident side with respect to the infrared pass filter 12P. That is, the infrared cut filter 13 may not have the through holes 13H. For example, the infrared cut filter 13 cuts off near-infrared light having a wavelength of 700 nm or more and 900 nm or less. With this configuration, even the infrared photoelectric conversion element 11P can efficiently detect near-infrared light having a wavelength of 940 nm.

A constituent material of the infrared cut filter 13 is a transparent resin containing an infrared absorbing pigment. Examples of infrared absorbing dyes include anthraquinone dyes, cyanine dyes, phthalocyanine dyes, dithiol dyes, diimmonium dyes, squarylium dyes, and croconium dyes. Examples of transparent resins include acrylic resins, polyamide resins, polyimide resins, polyurethane resins, polyester resins, polyether resins, polyolefin resins, polycarbonate resins, polystyrene resins, and norbornene resins. The infrared cut filter 13 is formed by film formation using a coating method or the like.

The transparent resin containing the infrared absorbing dye can be made photosensitive, and as with each coloring composition, a photopolymerization initiator, a polymerizable monomer, an organic solvent, a leveling agent, etc. are mixed to make the resin photosensitized. It can be a transparent infrared absorbing transparent resin composition. The patterning method is performed in the same manner as the color filter manufacturing method.

As shown in FIG. 6, the infrared pass filter 12P may be thicker than the color filters 12R, 12G, 12B. With this configuration, it is possible to reduce the restrictions on the thicknesses of the pass elements 12P1, 12P2, and 12P3, so that the infrared pass filter 12P can improve the non-transmittance of visible light.

Note that the microlenses 15R, 15G, 15B, and 15P may reduce the accuracy of processing due to steps in the base on which they are formed. In the configuration including the infrared cut filter 13, from the viewpoint of improving the flatness of the base of each microlens 15R, 15G, 15B, 15P, the thickness of each color filter 12R, 12G, 12B and the thickness of the infrared cut filter 13 is preferably approximately equal to the thickness of the infrared pass filter 12P.

The transmission spectrum of the infrared cut filter 13 preferably satisfies the following conditions [A1] and [A2].
[A1] The average transmittance is 80% or more in the range of 450 nm or more and 650 nm or less.

[A2] It has a maximum absorption (λmax) in the range of 700 nm to 1000 nm and a transmittance of 20% or less.
If the configuration satisfies [A1], absorption of visible light by the infrared cut filter 13 is sufficiently suppressed. If the configuration satisfies [A2], the near-infrared light that can be detected by the photoelectric conversion element 11 for each color is sufficiently cut by the infrared cut filter 13, and even visible light is sufficiently cut. suppressed by

[Infrared pass filter]
- The infrared pass filter 12P may be composed of a laminate of two-color filter elements, a first pass element 12P1 and a third pass element 12P3. Each color filter element is thinner than the color filter of the same color as the filter element and is made of the same material as the color filter. That is, the first pass element 12P1 is thinner than the red filter 12R and made of the same material as the red filter 12R. The third pass element 12P3 is thinner than the blue filter 12B and made of the same material as the blue filter 12B. The stacking order of the first path element 12P1 and the third path element 12P3 may be the order of the first path element 12P1 and the third path element 12P3, or the order of the third path element 12P3 and the first path element 12P1. .

According to the above modification, the same effect as the above-described embodiment can be obtained while reducing the number of layers of the infrared pass filter 12P.
- It is also possible to adopt a configuration in which a black matrix and a flattening layer are provided between the plurality of photoelectric conversion elements 11 and the respective color filters 12R, 12G, 12B and the infrared pass filter 12P. The black matrix suppresses the light of each color selected by each color filter 12R, 12G, 12B from entering other photoelectric conversion elements 11. FIG. The flattening layer fills the steps of the black matrix to flatten the underlayers of the color filters 12R, 12G, 12B and the infrared pass filter 12P, thereby making the microlenses 15R, 15G, 15B, 15P flat. flatten the substrate of

DESCRIPTION OF SYMBOLS 10... Filter for solid-state image sensors 11... Photoelectric conversion element 11R... Photoelectric conversion element for red 11G... Photoelectric conversion element for green 11B... Photoelectric conversion element for blue 11P... Photoelectric conversion element for infrared 12R... For red Filter 12G...Green filter 12B...Blue filter 12P...Infrared pass filter 12P1...First pass element 12P2...Second pass element 12P3...Third pass element 13...Infrared cut filter 15R ... red microlens, 15G ... green microlens, 15B ... blue microlens, 15P ... infrared microlens.

Claims (6)

Three color filters of a red filter, a green filter, and a blue filter positioned on the light incident side with respect to the first photoelectric conversion element;
an infrared pass filter located on the light incident side with respect to the second photoelectric conversion element,
The infrared pass filter is a laminate of filter elements of two or more colors including at least red and blue,
The filter element of each color is thinner than the color filter of the same color as the filter element and is made of the same material as the color filter ,
A common infrared cut filter located on the light incident side with respect to the first photoelectric conversion element and the second photoelectric conversion element, the filter blocking near-infrared light having a wavelength of 700 nm or more and 900 nm or less. Equipped with an infrared cut filter
Filter for solid-state image sensors. said infrared pass filter further comprising a green filter element,
2. The filter for a solid-state imaging device according to claim 1, wherein said green filter element is thinner than said color filter of the same color as said filter element and made of the same material as said color filter. 3. The filter for a solid-state imaging device according to claim 1, wherein the thickness of said infrared pass filter is equal to or greater than the thickness of said color filter. a photoelectric conversion element;
A solid-state imaging device, comprising the filter for a solid-state imaging device according to any one of claims 1 to 3 . a three-color filter positioned on the light incident side with respect to the first photoelectric conversion element;
A method for manufacturing a filter for a solid-state imaging device, comprising: an infrared pass filter positioned on the light incident side with respect to the second photoelectric conversion device,
The infrared pass filter is a laminate of filter elements of two or more colors including at least red and blue,
The filter element of each color is thinner than the color filter of the same color as the filter element and is made of the same material as the color filter,
While forming the color filters of each color in separate steps,
forming the color filters of each color and the filter elements of the same color as the color filters in the same process;
A common infrared cut filter located on the light incident side with respect to the first photoelectric conversion element and the second photoelectric conversion element, the filter blocking near-infrared light having a wavelength of 700 nm or more and 900 nm or less. Further forming an infrared cut filter
A method for manufacturing a filter for a solid-state imaging device. a step of forming a photoelectric conversion element;
A method for manufacturing a solid-state imaging device, comprising: forming a solid-state imaging device filter on a light incident side of the photoelectric conversion device by using the solid-state imaging device filter manufacturing method according to claim 5 .

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