JP2020122902A - Filter for solid-state image sensor, solid-state image sensor, method of manufacturing filter for solid-state image sensor, and method of manufacturing solid-state image sensor - Google Patents

Abstract

To provide a filter for a solid-state image sensor, a solid-state image sensor, a method of manufacturing a filter for a solid-state image sensor, and a method of manufacturing a solid-state image sensor, capable of preventing a yield rate from decreasing or a cost from increasing.SOLUTION: The filter for a solid-state image sensor comprises: color filters in three colors located on the light incident side with respect to photoelectric conversion elements for respective colors 11R, 11G and 11B; and an infrared pass filter 12P located on the light incident side with respect to an infrared photoelectric conversion element 11P. The infrared pass filter 12P is a laminated body consisting of filter elements in three colors. A filter element in each color is made of a material which is thinner than the color filter in the same color with the filter element and also which is the same material with the color filter.SELECTED DRAWING: Figure 1

Description

The present invention relates to a solid-state image sensor filter, a solid-state image sensor including the solid-state image sensor filter, a method for manufacturing a solid-state image sensor filter, and a solid-state image sensor manufacturing method.

A solid-state image sensor such as a CMOS image sensor or a CCD image sensor includes a photoelectric conversion element that converts light intensity into an electric signal. The solid-state image sensor has a plurality of photoelectric conversion elements and a color filter located on the photoelectric conversion element for each color. Furthermore, the solid-state image sensor equipped with an infrared sensor function is mounted on the infrared photoelectric conversion element. Infrared pass filter located (see, for example, Patent Document 1).

The color filter converts the color of the received light into the three primary color system of light including red, green and blue, or the three primary color system 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 blocks visible light that can be detected by the infrared photoelectric conversion element, and increases the accuracy of infrared light detection by the infrared photoelectric conversion element. In the constituent material of the infrared pass filter, for example, as described in Patent Document 1, a coloring composition for the infrared pass filter is prepared by using a single compound or a combination of a plurality of compounds from at least one of a pigment and a dye. It is a thing. Alternatively, as described in Patent Document 2, a black color material such as a bisbenzofuranone pigment, an azomethine pigment, a perylene pigment, and an azo dye is used as a coloring composition for an infrared pass filter. Alternatively, as described in Patent Document 3, a combination of a black color material and color pigments such as red, blue, green, and yellow is known.

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

The solid-state imaging device including the color filter and the infrared pass filter enables visible light detection and infrared light detection, while the visible light detection and the red light detection are performed as in the manufacturing methods described in Patent Documents 1 to 3. The ambient light detection is manufactured from different constituent materials. The use of the different constituent materials for manufacturing complicates the manufacturing process and the use process of the solid-state imaging device, and causes problems such as a decrease in the yield rate and an increase in cost.

An object of the present invention is to provide a filter for a solid-state image sensor, a solid-state image sensor, a method for manufacturing a filter for a solid-state image sensor, and a method for manufacturing a solid-state image sensor, which can suppress a decrease in the yield rate and an increase in cost. Is.

A solid-state image sensor filter for solving the above-mentioned problems includes a three-color filter including a red filter, a green filter, and a blue filter located on the light incident side with respect to the first photoelectric conversion element, and a second photoelectric filter. An infrared pass filter located on the incident side of light with respect to the conversion element, and the infrared pass filter is a laminate of two or more color filter elements containing at least red and blue, the filter of each color The 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.

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

In the solid-state image sensor filter, the infrared pass filter further includes a green filter element, the green filter element is thinner than the color filter of the same color as the filter element, and the color filter and They may be composed of the same material. With this configuration, it is possible to suppress the above-mentioned difference in the processing conditions and the difference in the use environment even in the solid-state image sensor filter including the green filter element.

In the solid-state image sensor filter, the thickness of the infrared pass filter may be equal to or greater than the thickness of the color filter. With this configuration, the restriction of thinning each filter element can be reduced, and thus the non-transparency of visible light in the infrared pass filter can be improved.

The solid-state image sensor filter may further include an infrared cut filter located on the light incident side of the first photoelectric conversion element. With this configuration, the accuracy of detection of visible light by the first photoelectric conversion element can be improved, and the step difference between the infrared pass filter and the color filter can be reduced by the infrared cut filter. An infrared cut filter may be provided on the light incident side of the second photoelectric conversion element.

In the solid-state image sensor filter, a through hole may be provided at a position corresponding to the infrared pass filter of the infrared cut filter. With this configuration, the infrared light cut by the infrared cut filter can be detected by the second photoelectric conversion element.

A solid-state image sensor for solving the above-described problems includes a photoelectric conversion element and the solid-state image sensor filter.
A method for manufacturing a filter for a solid-state image sensor for solving the above-mentioned problems is provided by a color filter of three colors positioned on the light incident side of a first photoelectric conversion element and a light incident side of a second photoelectric conversion element. Infrared pass filter located, a method for manufacturing a solid-state imaging device filter comprising, the infrared pass filter is a laminate of two or more color filter elements containing 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 composed of the same material as the color filter, to form the color filter of each color in a separate step, the 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 of the same material. Therefore, it is possible to suppress a difference depending on the constituent material between the processing conditions suitable for the color filter and the processing conditions suitable for the infrared pass filter. Further, it is possible to prevent the difference depending on the constituent material between the usage environment suitable for the color filter and the usage environment suitable for the infrared pass filter. In addition, since the color filter of each color and the filter element of the same color as the color filter are formed in the same step, the productivity of the solid-state image sensor filter can be improved.

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

FIG. 3 is an exploded perspective view partially showing a layer structure in one embodiment of the solid-state imaging device. II-II sectional view taken on the line of FIG. The graph which shows an example of the transmission spectrum of an infrared pass filter. (A) (b) (c) Sectional drawing which shows each process in one Embodiment of a solid-state image sensor. FIG. 6 is an exploded perspective view partially showing a layer structure in a modification of the solid-state image sensor. VI-VI sectional view taken on the line of FIG.

Hereinafter, an embodiment of a solid-state image sensor filter, a solid-state image sensor, a method for manufacturing a solid-state image sensor filter, and a method for manufacturing a solid-state image sensor will be described with reference to FIGS. 1 to 4. FIG. 1 is a schematic configuration diagram in which each layer in a part of the solid-state imaging device is shown separately.

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

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

The three-color photoelectric conversion element 11 is an example of a first photoelectric conversion element, and includes a red photoelectric conversion element 11R, a green photoelectric conversion element 11G, and a blue photoelectric conversion element 11B. 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 the photoelectric conversion element 11 in the solid-state image sensor.

The color filters for the three colors include a red filter 12R, a green filter 12G, and a blue filter 12B. The red filter 12R is located on the light incident side with respect to the red photoelectric conversion element 11R. The green filter 12G is located 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 alone 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 thermal decomposition resistance is preferable, and an organic pigment is used. The pigments include phthalocyanine-based, azo-based, anthraquinone-based, quinacridone-based, dioxazine-based, ansanthuron-based, indanthrone-based, perylene-based, thioindigo-based, isoindoline-based, quinophthalone-based, and diketopyrrolopyrrole-based organic pigments. Is 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 the blue dye used in the blue photosensitive coloring composition of each color filter include CI Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 22, 22 and 60, Pigments such as 64 and 81 are mentioned, and CI Pigment Blue 15:6 is preferable among them. Examples of the purple pigment include pigments such as CI Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42 and 50, and CI Pigment Violet 23 is preferable among them.

As the yellow pigment, CI 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, Pigments such as 185, 187, 188, 193, 194, 198, 199, 213 and 214 are mentioned, and CI Pigment Yellow 13, 150 and 185 are preferable among them.

The red photosensitive coloring composition has, for example, CI Pigment Red 7, 9, 14, 41, 48:1, 48:2, 48:3, 48:4, 81:1, 81: instead of the blue dye. 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, 224, 226, 227, 228, 240, 246, 254, 255, 264, 272, red pigments such as CI Pigment Orange 36, 43, 51, 55, 59, 61, 71, 73, and for toning as needed. CI 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 and the like.

In addition, a green photosensitive coloring composition is obtained by using, for example, a green pigment such as CI Pigment Green 7, 10, 367, 58, and the above yellow pigment for toning, instead of the blue dye. The composition is

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 the binder resin include acrylic resin, polyamide resin, polyimide resin, polyurethane resin, polyester resin, polyether resin, polyolefin resin, polycarbonate resin, polystyrene resin, norbornene resin.

As the photopolymerization initiator, for example, acetophenone photopolymerization initiator, benzoin photopolymerization initiator, benzophenone photopolymerization initiator, thioxanthone photopolymerization initiator, triazine photopolymerization initiator, oxime ester photopolymerization initiator. Etc. are used alone or in combination of two or more.

As the polymerizable monomer, (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)acrylates such as (meth)acrylate and tetrahydrofurfuryl (meth)acrylate; N-vinylpyrrolidone; styrene and its derivatives; styrenes such as α-methylstyrene; (meth)acrylamide, methylol (meth)acrylamide , Acrylamides such as alkoxymethylol (meth)acrylamide, diacetone (meth)acrylamide; other vinyl compounds such as (meth)acrylonitrile, ethylene, propylene, butylene, vinyl chloride, vinyl acetate, and polymethylmethacrylate macromonomer, polystyrene macro Examples thereof include macromonomers such as monomers. These monomers may be used alone or in combination of two or more.

Examples of the organic solvent 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, methyl Examples thereof include cyclohexanol, n-amyl acetate, n-butyl acetate, isoamyl acetate, isobutyl acetate, propyl acetate and dibasic acid ester. These may be used alone or in combination of two or more.

As the leveling agent, dimethylsiloxane having a polyether structure or a polyester structure in the main chain is preferable. Specific examples of dimethylsiloxane having a polyether structure in the main chain include FZ-2122 manufactured by Toray Dow Corning, BYK-333 manufactured by Big Chemie, and the like. Specific examples of the dimethylsiloxane having a polyester structure include BYK-310 and BYK-370 manufactured by BYK Chemie. Dimethylsiloxane having a polyether structure and dimethylsiloxane having a polyester structure can be used in combination. These may be used alone or in combination of two or more.

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

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

The first pass element 12P1, the second pass element 12P2, and the third pass element 12P3 may be stacked in the order of the first pass element 12P1, the second pass element 12P2, and the third pass element 12P3. The order may be the element 12P1, the third path element 12P3, and the second path element 12P2. 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 second pass element 12P2, the first pass element 12P1, and the third pass element 12P3, or the second pass element. The order may be the element 12P2, the third path element 12P3, and the first path element 12P1. 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, or the third pass element. 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 with respect to the infrared photoelectric conversion element 11P, thereby increasing the accuracy of visible light detection 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 shows a transmittance of 10% or less in the range of 400 nm to 700 nm, for example. On the other hand, the infrared pass filter 12P has a transmittance of 10% or more with a peak near 900 nm, and a transmittance of 90% or more in the range exceeding 900 nm.

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

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

Each of the microlenses 15R, 15G, 15B and 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 between the microlenses 15R, 15G, 15B, and 15P for collecting the light entering the incident surface 15S toward the photoelectric conversion elements 11R, 11G, 11B, and 11P, and the outside air.

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

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. The method for manufacturing the solid-state image sensor filter includes a second step of forming the green filter 12G and the second pass element 12P2 having the same color as the green filter 12G. The method for manufacturing the solid-state image sensor filter includes a third step of forming the blue filter 12B and the third pass element 12P3 having the same color as the blue filter 12B. The method for manufacturing the solid-state image sensor filter includes a fourth step of forming the microlenses 15R, 15G, 15B, and 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 by patterning the coating film 12RD using a photolithography method, The red filter 12R and the 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 subjecting the coating film 12RD to exposure and development in a range corresponding to the region of the red filter 12R. Further, the first pass element 12P1 uses a halftone mask or a gradation mask at the time of exposure for forming the red color filter 12R, and exposes a range corresponding to the area 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, on the red filter 12R and the first pass element 12P1, and on the green photoelectric conversion element 11G and the blue photoelectric conversion element 11B. The coating film 12GD including the green photosensitive resin is formed, and the green filter 12G and the second pass element 12P2 are formed by patterning the coating film 12GD using the photolithography method.

For example, the coating film 12GD containing the green photosensitive resin is formed by applying a coating liquid containing the green photosensitive resin and drying the coating film 12GD. The green filter 12G is formed by subjecting the coating film 12GD to exposure and development in a range corresponding to the area of the green filter 12G. Further, the second pass element 12P2 uses a halftone mask or a gradation mask at the time of exposure for forming the green color filter 12G, and exposes a range corresponding to the area of the second pass element 12P2, and It is formed by developing. The coating film 12GD located on the blue photoelectric conversion element 11B and the red filter 12R is 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, and photolithography is performed. By patterning the coating film 12BD using the method, the blue filter 12B and the third pass element 12P3 are formed.

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 subjecting the coating film 12BD to exposure and development in a range corresponding to the area 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. The coating film 12BD located on the red filter 12R and the green filter 12G is removed by the above-mentioned exposure and development.

In the fourth step, a coating film containing a transparent resin is formed on the filters 12R, 12G, 12B for each color and the infrared pass filter 12P. Then, the coating film made of the transparent resin is subjected to patterning of the coating film using a photolithography method and reflowing by heat treatment to form each microlens 15R, 15G, 15B, 15P. The transparent resin is, for example, an acrylic resin, a polyamide resin, a polyimide resin, a polyurethane resin, a polyester resin, a polyether resin, a polyolefin resin, a polycarbonate resin, a polystyrene resin, or a norbornene resin.

The infrared light transmission function of the infrared pass filter 12P may change depending on the thickness of the infrared pass filter 12P. The microlenses 15R, 15G, 15B on the filters 12R, 12G, 12B for the respective colors and the microlens 15P on the infrared pass filter 12P are composed of the filters 12R, 12G, 12B for the respective colors and the infrared pass filter 12P. Due to the step between them, the accuracy of the processing can be reduced. Therefore, from the viewpoint of improving the flatness of the microlenses 15R, 15G, 15B, and 15P on the base, the thicknesses of the color filters 12R, 12G, and 12B and the infrared pass filter 12P are substantially equal to each other. It is preferable.

Alternatively, a flattening layer may be provided between the filters 12R, 12G, 12B for each color and the infrared pass filter 12P and the microlens 15P. With the configuration including the flattening layer, the thickness difference between the filters 12R, 12G, 12B for each color and the infrared pass filter 12P is reduced, thereby flattening the base of the microlenses 15R, 15G, 15B, 15P. it can.

Further, when forming each microlens 15R, 15G, 15B, 15P, the material of the microlens 15R, 15G, 15B, 15P may be used instead of the flattening layer. The height difference due to the difference in the 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 effects listed below can be obtained.
(1) The three color pass elements 12P1, 12P2, 12P3 and the three color filters are made of the same material. Therefore, it is possible to suppress a difference depending on the constituent material between the processing condition suitable for the color filter and the processing condition suitable for the infrared pass filter 12P.

(2) It is possible to suppress a difference depending on the constituent material 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 the solid-state image pickup device equipped with the 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 color filter are formed in the same process. It is possible to manufacture the filter without lowering its productivity.

(4) Moreover, the coating films 12RD, 12GD, 12BD for forming the filters 12R, 12G, 12B for the respective colors and the coating films 12RD, 12GD, 12BD for forming the respective pass elements 12P1, 12P2, 12P3, Formed as a single coating. Therefore, the materials required for forming the filters 12R, 12G, 12B for the respective colors and the infrared pass filter 12P can be used more effectively.

The above embodiment can be modified as follows.
[Infrared cut filter]
-The solid-state image sensor can also be provided with the infrared cut filter 13 separately. The infrared cut filter 13 cuts into the photoelectric conversion element 11 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 improved.

For example, as shown in FIG. 5, the infrared cut filter 13 may include a through hole 13H on the light incident side of the infrared pass filter 12P and may not be located 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.

The 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 located on the light incident side with respect to the infrared pass filter 12P. That is, the infrared cut filter 13 may not include the through hole 13H. The infrared cut filter 13 blocks, for example, near infrared light having a wavelength of 700 nm or more and 900 nm or less. With this configuration, the near-infrared light having a wavelength of 940 nm can be efficiently detected also in the infrared photoelectric conversion element 11P.

The constituent material of the infrared cut filter 13 is a transparent resin containing an infrared absorbing dye. The infrared absorbing dye is, for example, an anthraquinone dye, a cyanine dye, a phthalocyanine dye, a dithiol dye, a diimonium dye, a squarylium dye, or a croconium dye. The transparent resin is, for example, an acrylic resin, a polyamide resin, a polyimide resin, a polyurethane resin, a polyester resin, a polyether resin, a polyolefin resin, a polycarbonate resin, a polystyrene resin, or a norbornene resin. The infrared cut filter 13 is formed by film formation using a coating method or the like.

A transparent resin containing an infrared absorbing dye can have photosensitivity, and as with each coloring composition, a photopolymerization initiator, a polymerizable monomer, an organic solvent, a leveling agent, etc. are mixed to form a photosensitive resin. Infrared absorbing transparent resin composition. The patterning method is the same as the color filter manufacturing method.

As shown in FIG. 6, the infrared pass filter 12P may be thicker than each color filter 12R, 12G, 12B. With this configuration, the restriction on the thickness of each of the pass elements 12P1, 12P2, and 12P3 can be reduced, and thus the non-transmittance of visible light can be improved in the infrared pass filter 12P.

Note that the microlenses 15R, 15G, 15B, and 15P can reduce the processing accuracy due to the step difference in the base on which they are formed. In the configuration including the infrared cut filter 13, the thickness of each color filter 12R, 12G, 12B and the infrared cut filter 13 are increased from the viewpoint of improving the flatness of each microlens 15R, 15G, 15B, 15P on the base. It is preferable that the total thickness of the infrared pass filter 12P and the thickness of the infrared pass filter 12P be substantially equal.

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 to 650 nm.

[A2] It has the maximum absorption (λmax) in the range of 700 nm or more and 1000 nm or less, and the transmittance is 20% or less.
With the configuration satisfying [A1], the absorption of visible light by the infrared cut filter 13 is sufficiently suppressed. With the configuration that satisfies [A2], it is sufficient that 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 cut. Suppressed to.

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

According to the modified example, the same effect as that of the above-described embodiment can be obtained while reducing the number of laminated infrared pass filters 12P.
A black matrix and a flattening layer may be provided between the plurality of photoelectric conversion elements 11 and the filters 12R, 12G, 12B for each color and the infrared pass filter 12P. The black matrix suppresses the light of each color selected by the filters 12R, 12G, and 12B for each color from entering the other photoelectric conversion element 11. The flattening layer fills the steps of the black matrix to flatten the base of each color filter 12R, 12G, 12B and the base of the infrared pass filter 12P, and thereby the microlenses 15R, 15G, 15B, 15P. Flatten the base.

10... Solid-state image sensor filter, 11... Photoelectric conversion element, 11R... Red photoelectric conversion element, 11G... Green photoelectric conversion element, 11B... Blue photoelectric conversion element, 11P... Infrared photoelectric conversion element, 12R... Red color 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 (8)

Three color filters, a red filter, a green filter, and a blue filter, which are located 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 two or more color filter elements containing at least red and blue,
A filter for a solid-state imaging device, wherein 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. The infrared pass filter further includes a green filter element,
The solid-state image sensor filter according to claim 1, wherein the green filter element is thinner than the color filter having the same color as the filter element, and is made of the same material as the color filter. The solid-state image sensor filter according to claim 1, wherein the infrared pass filter has a thickness equal to or greater than the thickness of the color filter. The solid-state image sensor filter according to claim 1, further comprising an infrared cut filter located on a light incident side with respect to the first photoelectric conversion element. The solid-state image sensor filter according to claim 4, wherein a through hole is provided at a position of the infrared cut filter corresponding to the infrared pass filter. A photoelectric conversion element,
A solid-state image sensor, comprising: the solid-state image sensor filter according to claim 1. A color filter of three colors 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 located on a light incident side with respect to a second photoelectric conversion element,
The infrared pass filter is a laminate of two or more color filter elements containing 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 composed of the same material as the color filter,
While forming the color filters of each color in separate steps,
A method for manufacturing a filter for a solid-state imaging device, comprising forming the color filter of each color and the filter element of the same color as the color filter in the same step. A step of forming a photoelectric conversion element,
A method for manufacturing a solid-state image sensor, comprising the step of forming the filter for solid-state image sensor on the light incident side of the photoelectric conversion element using the method for manufacturing a filter for solid-state image sensor according to claim 7.