JP2016146619A - Solid-state image pickup device and optical filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-state image pickup device that has high detection precision while suppressing the manufacturing cost.SOLUTION: A solid-state image pickup device comprises a first optical layer for transmitting at least a part of visible light and near infrared light therethrough, a near infrared light pass filter which absorbs at least a part of visible light and transmits at least a part of near infrared light therethrough, and a pixel array containing a first light reception element for detecting visible light transmitted through the first optical layer, and a second light reception element for detecting near infrared light transmitted through the first optical layer and the near infrared light pass filter. The near infrared light pass filter is provided to a portion corresponding to the second light reception element. When the transmittance of near infrared light in the first optical layer is measured in the vertical direction, a wavelength band from the shortest wavelength (X1) at which the transmittance is equal to 30% or more to the longest wavelength (X2) at which the transmittance is equal to 30% or less is represented by X, in the wavelength band (X), the product of the average transmittance of the first optical layer in the vertical direction and the average transmittance of the near infrared light pass filter is equal to 30% or more.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a solid-state imaging device and an optical filter. In particular, a solid-state imaging device using a dual band pass filter and a near infrared ray pass filter, and an optical filter having a dual band pass filter and a near infrared pass filter About.

  Conventionally, as a photoelectric conversion device, a solid-state imaging device used for imaging equipment such as a camera is known. The solid-state imaging device includes a light receiving element (visible light detection sensor) that detects visible light for each pixel, generates an electrical signal according to visible light incident from the outside, and processes the electrical signal to generate a captured image. To form. As a light receiving element, a CMOS image sensor, a CCD image sensor, and the like formed using a semiconductor process are widely known.

  In the above-described solid-state imaging device, in order to accurately detect the intensity of visible light incident on the light receiving element, light other than visible light that is a noise component is also shielded. For example, there is a technique of shielding an infrared light component using an infrared cut filter before incident light reaches a light receiving element. In this case, since only light in the visible light region reaches the light receiving element, a sensing operation with a relatively small noise component is possible.

  On the other hand, in recent years, there has been an increasing demand for providing a solid-state imaging device with sensing functions such as motion capture using near infrared light and distance recognition (space recognition). As a technique for that purpose, research into incorporating a distance image sensor adopting a TOF (Time Of Flight) system into a solid-state imaging device is underway.

  The TOF method is a technique for measuring the distance from the light source to the imaging object by measuring the time until the light output from the light source is reflected by the imaging object and returns. The light phase difference is used for time measurement. In other words, a phase difference occurs in the light that returns according to the distance to the object to be imaged. Therefore, in the TOF method, the phase difference is converted into a time difference, and an image is taken for each pixel based on the time difference and the speed of light. Measure the distance to the object.

  Since the solid-state imaging device using such a TOF method needs to detect the intensity of visible light and the intensity of near infrared light for each pixel, a light receiving element for detecting visible light and a near infrared light are detected for each pixel. It is necessary to provide a light receiving element for light detection. For example, as an example in which a light-receiving element for detecting visible light and a light-receiving element for detecting near-infrared light are provided in each pixel, a technique described in Patent Document 1 is known.

  Patent Document 1 describes an image sensing device in which an optical filter array including a dual band pass filter and an infrared pass filter and a pixel array including an RGB pixel array and a TOF pixel array are combined. In the technique described in Patent Document 1, visible light and infrared light are selectively passed by a dual band pass filter, and an infrared pass filter is provided only on the TOF pixel array to pass infrared light. As a result, visible light and infrared light are incident on the RGB pixel array, and infrared light is incident on the TOF pixel array, so that necessary light rays can be detected in each pixel array.

JP 2014-103657 A

  However, when the technique described in Patent Document 1 is used, not only visible light but also infrared light is incident on the RGB pixel array. Therefore, infrared light becomes noise, and only visible light cannot be accurately detected. There is a problem. Further, Patent Document 1 discloses a configuration in which a visible light path filter is provided on an RGB pixel array. In this case, it is necessary to dispose both a visible light path filter and an infrared path filter. There is a problem that the manufacturing cost increases. Further, Patent Document 1 only discloses a configuration in which infrared rays are selectively incident on the TOF pixel array, and no consideration is given to the amount of light incident on the TOF pixel array.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a solid-state imaging device with high detection accuracy while suppressing manufacturing cost.

  Another object of the present invention is to provide an optical filter suitable as an element constituting a solid-state imaging device.

  A solid-state imaging device according to an embodiment of the present invention includes a first optical layer that transmits at least part of visible light and near-infrared light, at least part of visible light, and at least part of near-infrared light. A near-infrared light path filter that passes through the first optical layer, a first light receiving element that detects the visible light that has passed through the first optical layer, and the near-light path filter that has passed through the first optical layer and the near-infrared light path filter. A solid-state imaging device including a pixel array including a second light receiving element for detecting infrared light, wherein the near-infrared light path filter is provided in a portion corresponding to the second light receiving element, When the transmittance of the near-infrared light in one optical layer is measured from the vertical direction, the shortest wavelength (X1) that is 30% or more to the longest wavelength (X2) that the transmittance is 30% or less. When the wavelength band is X, the wavelength band (X The near-infrared light path when measured from the vertical direction of the near-infrared light in the wavelength band (X) and the average transmittance of the first optical layer when measured from the vertical direction of the near-infrared light at The product of the average transmittance of the filter is 30% or more.

  At this time, the average transmittance of the first optical layer when measured from the vertical direction at a wavelength of 430 nm to 620 nm and the average transmittance of the near-infrared light path filter when measured from the vertical direction at the wavelength of 430 nm to 620 nm It is desirable that the product of is 30% or less.

  The wavelength of the near infrared light may be 750 to 2500 nm. The first optical layer may include a compound (A) that absorbs part of near infrared light. The compound (A) is selected from the group consisting of compounds having an absorption maximum at a wavelength of 600 to 850 nm, such as squarylium compounds, phthalocyanine compounds, naphthalocyanine compounds, croconium compounds, hexaphyrin compounds, and cyanine compounds. At least one compound may be used.

  The average transmittance of the first optical layer when measured from the vertical direction at wavelengths of 430 nm to 620 nm may be 60% or more. That is, in the second light receiving element, visible light having a wavelength of 430 nm to 620 nm is sufficiently cut by the near-infrared light pass filter. Therefore, even if the average transmittance of the first optical layer is 60% or more, the final light is received. The average transmittance can be 30% or less.

  The solid-state imaging device according to an embodiment of the present invention may further include a second optical layer having an opening at a portion corresponding to the second light receiving element and absorbing at least a part of near infrared light.

  In this case, the arrangement order (vertical relationship) of the first optical layer and the second optical layer may be either top, but the first optical layer is above the second optical layer (the side on which incident light first strikes). It is preferable that the second optical layer absorb at least part of the near-infrared light transmitted through the first optical layer.

  The second optical layer may include a compound having absorption in the wavelength band (X) (hereinafter also referred to as “compound (B)”). As the compound (B), a compound having an absorption maximum at a wavelength of 750 to 2000 nm, for example, a diiminium compound, a squarylium compound, a cyanine compound, a phthalocyanine compound, a naphthalocyanine compound, a quaterylene compound, an aminium compound, and an iminium compound From the group consisting of compounds, azo compounds, anthraquinone compounds, porphyrin compounds, pyrrolopyrrole compounds, oxonol compounds, croconium compounds, hexaphyrin compounds, metal dithiol compounds, copper compounds, tungsten compounds, metal borides At least one selected compound may be used.

  Here, the compound that can be used as the above-described compound (B) is exemplified in more detail below.

  Specific examples of the above-mentioned diiminium (diimonium) compounds include JP-A-01-113482, JP-A-10-180922, International Publication No. 2003/5076, International Publication No. 2004/48480, International Publication No. 2005 / No. 44782, International Publication No. 2006/120888, Japanese Unexamined Patent Publication No. 2007-246464, International Publication No. 2007/148595, Japanese Unexamined Patent Publication No. 2011-038007, Paragraph [0118] of International Publication No. 2011/118171, etc. The compound of this is mentioned. Examples of commercially available products include EPOLIGHT series such as EPOLIGHT1178 (manufactured by Epolin), CIR-108X series such as CIR-1085 and CIR-96X series (manufactured by Nippon Carlit), IRG022, IRG023, PDC-220 (Nippon Kayaku Co., Ltd.) Manufactured).

  Specific examples of the above-mentioned cyanine compounds include paragraphs [0041] to [0042] of JP-A No. 2007-271745, paragraphs [0016] to [0018] of JP-A No. 2007-334325, and JP-A No. 2009-108267. JP, 2009-185161, JP 2009-191213, JP 2012-215806, paragraph [0160], JP 2013-155353, paragraphs [0047] to [0049], etc. The compound of this is mentioned. As a commercial item, NK series (made by Hayashibara Biochemical Laboratories), such as Daito chmix 1371F (made by Daitoke mix company), NK-3212, NK-5060, etc. can be mentioned, for example.

Specific examples of the above-mentioned phthalocyanine compounds include JP-A-60-224589, JP-T-2005-537319, JP-A-4-23868, JP-A-4-39361, JP-A-5-78364. JP-A-5-2202047, JP-A-5-222301, JP-A-5-222302, JP-A-5-345861, JP-A-6-25548, JP-A-6-107663, JP-A-6-192484, JP-A-6-228533, JP-A-7-118551, JP-A-7-118552, JP-A-8-120186, JP-A-8-225751, JP-A-8-225575 JP-A-9-202860, JP-A-10-120927, JP-A-10-182959, JP-A-11-358 No. 8, JP-A 2000-26748, JP-A 2000-63691, JP-A 2001-106687, JP-A 2004-18561, JP-A 2005-220060, JP-A 2007-169343. And compounds described in paragraphs [0026] to [0027] of JP-A-2013-195480. Examples of commercially available products include FB series (manufactured by Yamada Chemical Co., Ltd.) such as FB-22, 24, Excolor series, Excolor TX-EX 720, 708K (manufactured by Nippon Shokubai), Lumogen IR788 (manufactured by BASF), ABS643, ABS654. , ABS667, ABS670T, IRA693N, IRA735 (manufactured by Exciton), SDA3598, SDA6075, SDA8030, SDA8303, SDA8470, SDA3039, SDA3040, SDA3922, SDA7257 (manufactured by HW SANDS), TAP-15, IR-706 Manufactured).

  Specific examples of the naphthalocyanine compound described above include paragraphs [0046] to [0049] of JP-A Nos. 11-152413, 11-152414, 11-152415, and 2009-215542. And the like.

Specific examples of the aforementioned quaterrylene compounds include the compounds described in paragraph [0021] of JP-A-2008-009206. As a commercial item, for example, Lumogen
IR765 (made by BASF) etc. can be mentioned.

  Specific examples of the aminium compound include the compounds described in paragraph [0018] of JP-A-08-027371, JP-A-2007-039343, and the like. As a commercial item, IRG002, IRG003 (made by Nippon Kayaku Co., Ltd.) etc. can be mentioned, for example.

  Specific examples of the aforementioned iminium-based compounds include compounds described in paragraph [0116] of International Publication No. 2011/118171.

  Specific examples of the above-mentioned azo compounds include compounds described in paragraphs [0114] to [0117] of JP 2012-215806 A.

  Specific examples of the aforementioned anthraquinone compounds include compounds described in paragraphs [0128] and [0129] of JP2012-215806A.

  Specific examples of the aforementioned pyrrolopyrrole compound include compounds described in paragraphs [0014] to [0027] of JP2011-068731A and JP2014130343A.

  Specific examples of the aforementioned oxonol-based compounds include compounds described in paragraph [0046] of JP-A-2007-271745.

  Specific examples of the aforementioned croconium compounds include compounds described in paragraph [0049] of JP-A No. 2007-271745, JP-A No. 2007-31644, JP-A No. 2007-169315, and the like.

  Specific examples of the above-mentioned metal dithiol compounds include JP-A-01-114801, JP-A-64-74272, JP-A-62-39682, JP-A-61-80106, JP-A-61-80. -42585 gazette, JP-A 61-32003 gazette, etc. are mentioned.

  As the above-mentioned copper compound, a copper complex is preferable, and specific examples include JP2013-253224A, JP2014-032380A, JP2014-026070A, JP20140261678A, and JP2014. -139616 gazette, Unexamined-Japanese-Patent No. 2014-139617, etc. are mentioned.

As the above-mentioned tungsten compound, a tungsten oxide compound is preferable, cesium tungsten oxide and rubidium tungsten oxide are more preferable, and cesium tungsten oxide is more preferable. Examples of the composition formula of cesium tungsten oxide include Cs _0.33 WO _{3 and the} like, and examples of the composition formula of rubidium tungsten oxide include Rb _0.33 WO _{3 and the} like. The tungsten oxide compound is also available as a dispersion of tungsten fine particles such as YMF-02A manufactured by Sumitomo Metal Mining Co., Ltd.

  Specific examples of the aforementioned metal boride include the compounds described in paragraph [0049] of JP 2012-068418 A. Of these, lanthanum boride is preferable. In addition, when the said compound (B) is an organic compound, it can also be used as a lake pigment | dye. A known method can be adopted as a method for producing the lake dye, and for example, JP-A-2007-271745 can be referred to.

The near-infrared light pass filter is not particularly limited as long as it absorbs at least part of visible light and transmits at least part of near-infrared light. However, the following conditions (I) and (II) ) Is preferable. In particular, from the viewpoint of miniaturization of the solid-state imaging device, it is more preferable to satisfy the following conditions (I) and (II) when the film thickness is 1.2 μm.
Condition (I): The average transmittance of light at a wavelength of 450 to 600 nm is 15% or less.
Condition (II): The average transmittance of light at a wavelength of 900 to 1000 nm is 80% or more.

Such a near-infrared light path filter includes, for example, a compound having an absorption maximum in the visible light wavelength range (typically, a wavelength of 430 to 620 nm) (hereinafter also referred to as “compound (C)”). Is preferred. Although it does not specifically limit as such a compound (C), For example, the coloring agent containing the following compounds (C1)-(C3) at least, and the coloring agent containing the following compounds (C4)-(C6), for example Is mentioned.
(C1) Colorant represented by the following formula (1) (however, 40 to 80% by mass in all colorants)
(C2) One or more colorants selected from blue colorants and green colorants (however, 10 to 40% by mass in all colorants)
(C3) One or more colorants selected from yellow colorants and red colorants (however, 10 to 40% by mass in all colorants)
(C4) One or more colorants selected from a compound having a structure represented by the following formula (2) and a compound having a structure represented by the following formula (3) (C5) One selected from a purple colorant and a red colorant The above colorant (C6) yellow colorant

  (In formula (2), M represents a metal atom.)

In formula (1), R ¹ and R ² each independently represent a hydrogen atom, a hydroxyl group, a methoxy group, or an acetyl group. R ³ and R ⁴ each independently represent a phenylene group or a direct bond. R ⁵ and R ⁶ each independently represent a direct bond or an alkanediyl group having 1 to 10 carbon atoms. However, R ³ and R ⁵ are not directly bonded simultaneously, and R ⁴ and R ⁶ are not directly bonded simultaneously.

  Here, the compounds that can be used as the above-described compounds (C1) to (C6) are exemplified in more detail below.

Compound (C1)
Examples of the perylene compounds represented by the formula (1) include those having the following color index numbers (CI; issued by The Society of Dyers and Colorists, the same shall apply hereinafter). it can.

  C. I. Pigment black 31, C.I. I. Pigment Black 32.

  The compound represented by the formula (1) can be obtained, for example, by reacting perylene-3,5,9,10-tetracarboxylic acid or a dianhydride thereof with an amine compound in water or an organic solvent. it can. For the operation method, reference can be made to, for example, the descriptions in JP-A Nos. 62-1753 and 63-26784.

Compound (C2)
Compound (C2) is one or more colorants selected from blue colorants and green colorants. The blue colorant and the green colorant have an absorption band in the visible region of 600 to 750 nm and transmit the near infrared region of 800 nm or more. As the blue colorant and the green colorant, either a pigment or a dye can be used, and the pigment may be an organic pigment or an inorganic pigment. In addition, a blue coloring agent and a green coloring agent can be used individually or in combination of 2 or more types, respectively.

  Examples of the blue colorant include phthalocyanine-based, anthraquinone-based, and dioxazine-based pigments. Examples of color index numbers are as follows.

  C. I. Pigment blue 1, C.I. I. Pigment blue 2, C.I. I. Pigment blue 3, C.I. I. Pigment blue 9, C.I. I. Pigment blue 10, C.I. I. Pigment blue 14, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 15: 6, C.I. I. Pigment blue 17: 1, C.I. I. Pigment blue 24, C.I. I. Pigment blue 24: 1, C.I. I. Pigment blue 56, C.I. I. Pigment blue 60, C.I. I. Pigment blue 61, C.I. I. Pigment blue 62, C.I. I. Blue pigments such as CI Pigment Blue 80.

  Examples of the dye include those having the following color index numbers.

C. I. Bat Blue 4, C.I. I. Acid Blue 40, C.I. I. Reactive Blue 19, C.I. I. Reactive Blue 49, C.I. I. Disperse Blue 56, C.I. I. Anthraquinone blue dyes such as Disperse Blue 60;
C. I. Acid Blue 7, C.I. I. Basic Blue 1, C.I. I. Basic Blue 5, C.I. I. Basic Blue 7, C.I. I. Basic Blue 11, C.I. I. Triarylmethane blue dyes such as Basic Blue 26;
C. I. Phthalocyanine blue dyes such as Pad Blue 5;
C. I. Basic Blue 3, C.I. I. Quinoneimine blue dyes such as Basic Blue 9.

  Examples of the green colorant include phthalocyanine-based and anthraquinone-based pigments. Examples of color index numbers are as follows.

  C. I. Pigment green 1, C.I. I. Pigment green 4, C.I. I. Pigment green 7, C.I. I. Pigment green 36, C.I. I. Green pigments such as CI Pigment Green 58.

  Examples of the dye include those having the following color index numbers.

  C. I. Direct Green 28, C.I. I. Azo-based green dyes such as Direct Green 59; I. Anthraquinone green dyes such as Acid Green 25; I. Basic Green 1, C.I. I. Basic Green 4 and other triarylmethane green dyes.

  As the compound (C2), a blue colorant is preferable, a copper phthalocyanine pigment is preferable, and a C.I. I. Pigment Blue 15: 6 is more preferable.

Compound (C3)
Compound (C3) is one or more colorants selected from yellow colorants and red colorants. The yellow colorant and the red colorant have an absorption band in the visible region of 380 to 480 nm, and transmit the near infrared region of 800 nm or more. Therefore, without impairing the transmittance in the near infrared region, The visible region can be shielded from light. As the yellow colorant and the red colorant, either a pigment or a dye can be used, and the pigment may be an organic pigment or an inorganic pigment. The yellow colorant and the red colorant can be used alone or in combination of two or more.

  Examples of the yellow colorant include anthraquinone, isoindolinone, condensed azo, benzimidazolone, monoazo, and disazo pigments. Examples of the pigment to which the color index number is attached include the following.

C. I. Solvent Yellow 163, C.I. I. Pigment yellow 24, C.I. I. Pigment yellow 108, C.I. I. Pigment yellow 193, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 199, C.I. I. Anthraquinone yellow pigments such as CI Pigment Yellow 202;
C. I. Pigment yellow 110, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 139, C.I. I. Pigment yellow 179, C.I. I. Isoindolinone-based yellow pigments such as CI Pigment Yellow 185;
C. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 155, C.I. I. Pigment yellow 166, C.I. I. Condensed azo yellow pigments such as CI Pigment Yellow 180;
C. I. Pigment yellow 120, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 156, C.I. I. Pigment yellow 175, C.I. I. Benzimidazolone yellow pigments such as CI Pigment Yellow 181;
C. I. Pigment yellow 1, C.I. I. Pigment yellow 2, C.I. I. Pigment yellow 3, C.I. I. Pigment yellow 4, C.I. I. Pigment yellow 5, C.I. I. Pigment yellow 6, C.I. I. Pigment yellow 9, C.I. I. Pigment yellow 10, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 61, C.I. I. Pigment yellow 62, C.I. I. Pigment yellow 62: 1, C.I. I. Pigment yellow 65, C.I. I. Pigment yellow 73, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 75, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 100, C.I. I. Pigment yellow 104, C.I. I. Pigment yellow 105, C.I. I. Pigment yellow 111, C.I. I. Pigment yellow 116, C.I. I. Pigment yellow 167, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 169, C.I. I. Pigment yellow 182, C.I. I. Monoazo yellow pigments such as CI Pigment Yellow 183;
C. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 16, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 55, C.I. I. Pigment yellow 63, C.I. I. Pigment yellow 81, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 87, C.I. I. Pigment yellow 126, C.I. I. Pigment yellow 127, C.I. I. Pigment yellow 152, C.I. I. Pigment yellow 170, C.I. I. Pigment yellow 172, C.I. I. Pigment yellow 174, C.I. I. Pigment yellow 176, C.I. I. Pigment yellow 188, C.I. I. Disazo yellow pigments such as CI Pigment Yellow 198.

  Examples of the dye include those having the following color index numbers.

C. I. Acid Yellow 11, C.I. I. Direct Yellow 12, C.I. I. Reactive Yellow 2, C.I. I. Azo-based yellow dyes such as Moldant Yellow 5;
C. I. Solvent Yellow 33, C.I. I. Acid Yellow 3, C.I. I. Quinoline yellow dyes such as Disperse Yellow 64;
C. I. Acid Yellow 1, C.I. I. Nitro-based yellow dyes such as Disperse Yellow 42;
C. I. Methine yellow dyes such as Disperse Yellow 201;
C. I. Basic Yellow 1, C.I. I. Basic Yellow 11, C.I. I. Basic Yellow 13, C.I. I. Basic Yellow 21, C.I. I. Basic Yellow 28, C.I. I. Basic Yellow 51, C.I. I. Cyanine yellow dyes such as Reactive Yellow 1

  Examples of the red colorant include monoazo, disazo, monoazo lake, benzimidazolone, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone pigments. Examples of the pigment to which the color index number is attached include the following.

C. I. Pigment red 1, C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 4, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 8, C.I. I. Pigment red 9, C.I. I. Pigment red 12, C.I. I. Pigment red 14, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 17, C.I. I. Pigment red 21, C.I. I. Pigment red 22, C.I. I. Pigment red 23, C.I. I. Pigment red 31, C.I. I. Pigment red 32, C.I. I. Pigment red 112, C.I. I. Pigment red 114, C.I. I. Pigment red 146, C.I. I. Pigment red 147, C.I. I. Pigment red 151, C.I. I. Pigment red 170, C.I. I. Pigment red 184, C.I. I. Pigment red 187, C.I. I. Pigment red 188, C.I. I. Pigment red 193, C.I. I. Pigment red 210, C.I. I. Pigment red 245, C.I. I. Pigment red 253, C.I. I. Pigment red 258, C.I. I. Pigment red 266, C.I. I. Pigment red 267, C.I. I. Pigment red 268, C.I. I. Monoazo red pigments such as CI Pigment Red 269;
C. I. Pigment red 37, C.I. I. Pigment red 38, C.I. I. Disazo red pigments such as CI Pigment Red 41;
C. I. Pigment red 48: 1, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 48: 4, C.I. I. Pigment red 49: 1, C.I. I. Pigment red 49: 2, C.I. I. Pigment red 50: 1, C.I. I. Pigment red 52: 1, C.I. I. Pigment red 52: 2, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 53: 2, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 58: 4, C.I. I. Pigment red 63: 1, C.I. I. Pigment red 63: 2, C.I. I. Pigment red 64: 1, C.I. I. Monoazo lake red pigments such as CI Pigment Red 68;
C. I. Pigment red 171, C.I. I. Pigment red 175, C.I. I. Pigment red 176, C.I. I. Pigment red 185, C.I. I. Benzimidazolone red pigments such as CI Pigment Red 208;
C. I. Pigment red 254, C.I. I. Pigment red 255, C.I. I. Pigment red 264, C.I. I. Pigment red 270, C.I. I. Pigment Red 272, a diketopyrrolopyrrole red pigment such as a compound represented by the following formula (4);
C. I. Pigment red 220, C.I. I. Pigment red 144, C.I. I. Pigment red 166, C.I. I. Pigment red 214, C.I. I. Pigment red 220, C.I. I. Pigment red 221, C.I. I. Condensed azo red pigments such as CI Pigment Red 242;
C. I. Pigment red 168, C.I. I. Pigment red 177, C.I. I. Pigment red 216, C.I. I. Solvent Red 149, C.I. I. Solvent Red 150, C.I. I. Solvent Red 52, C.I. I. Anthraquinone red pigments such as Solvent Red 207;
C. I. Pigment red 122, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 207, C.I. I. Quinacridone red pigments such as CI Pigment Red 209;

  Examples of the dye include those having the following color index numbers.

C. I. Acid Red 37, C.I. I. Acid Red 180, C.I. I. Acid Blue 29, C.I. I. Direct Red 28, C.I. I. Direct Red 83, C.I. I. Reactive Red 17, C.I. I. Reactive Red 120, C.I. I. Disperse thread 58, C.I. I. Basic Red 18, C.I. I. Azo red dyes such as Moldand Red 7;
C. I. Anthraquinone red dyes such as Disperse Red 60;
C. I. Acid Red 52, C.I. I. Acid Red 87, C.I. I. Acid Red 92, C.I. I. Acid Red 289, C.I. I. Xanthene red dyes such as Acid Red 388;
C. I. Basic Red 12, C.I. I. Basic Red 13, C.I. I. Cyanine red dyes such as Basic Red 14.

  As the compound (C3), a yellow colorant is preferable, an isoindolinone-based pigment is preferable, and a C.I. I. Pigment Yellow 139 is more preferable.

Compound (C4)
The compound (C4) is one or more colorants selected from a compound having a structure represented by the formula (2) and a compound having a structure represented by the formula (3). The compound having the structure represented by the formula (2) and the compound having the structure represented by the formula (3) have an absorption band in the visible region of 600 to 700 nm and transmit the near infrared region of 800 nm or more. The compound having the structure represented by the formula (2) and the compound having the structure represented by the formula (3) can be used alone or in combination of two or more.

  In the formula (2), the metal atom in M is preferably a divalent metal atom. For example, Be, Mg, Ca, Ba, Al, Si, Cd, Hg, Cr, Fe, Co, Ni, Cu, Zn, Ge, Pd, Cd, Sn, Pt, Pb, Sr, Mn, etc. can be mentioned. Among these, Cu is preferable.

  Examples of the compound having the structure represented by the formula (2) and the compound having the structure represented by the formula (3) include those having the following color index numbers.

  C. I. Pigment blue 15, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 15: 6 (a compound in which M is Cu in the formula (2)), C.I. I. Pigment Blue 16 (a compound represented by the formula (3)).

  As the compound (C4), a compound having a structure represented by the above formula (2) is preferable because the photosensitive composition is more excellent in resolution, and a compound in which M is Cu in the above formula (2). More preferably, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment Blue 15: 6 is more preferable, and C.I. I. Pigment Blue 15: 4 is particularly preferable.

Compound (C5)
Compound (C5) is one or more colorants selected from purple colorants and red colorants. The purple colorant has an absorption band in the visible region of 500 to 600 nm and transmits the near infrared region of 800 nm or more. The red colorant is the same as the red colorant described as the compound (C3).

  As the purple colorant and the red colorant, either a pigment or a dye can be used, and the pigment may be an organic pigment or an inorganic pigment. In addition, a purple coloring agent and a red coloring agent can be used individually or in combination of 2 or more types, respectively.

  As the purple colorant, for example, those with the following color index numbers can be cited.

  C. I. Pigment violet 1, C.I. I. Pigment violet 2, C.I. I. Pigment violet 3, C.I. I. Pigment violet 3: 1, C.I. I. Pigment violet 3: 3, C.I. I. Pigment violet 13, C.I. I. Pigment violet 19, C.I. I. Pigment violet 23, C.I. I. Pigment violet 25, C.I. I. Pigment violet 27, C.I. I. Pigment violet 29, C.I. I. Pigment violet 32, C.I. I. Pigment violet 36, C.I. I. Pigment violet 37, C.I. I. Pigment violet 38, C.I. I. Purple pigments such as pigment violet 39.

Examples of the purple dye include those having the following color index numbers.
C. I. Basic violet 1, C.I. I. Basic violet 3, C.I. I. Triarylmethane-based purple dyes such as Basic Violet 14;
C. I. Xanthene-based purple dyes such as Basic Violet 11;
C. I. Basic Violet 7, C.I. I. Cyanine purple dyes such as Basic Violet 16;
C. I. Solvent Violet 8, C.I. I. Solvent Violet 13, C.I. I. Solvent Violet 14, C.I. I. Solvent Violet 21, C.I. I. Solvent Violet 27, C.I. I. Solvent Violet 28, C.I. I. Anthraquinone-based purple dyes such as Solvent Violet 36

  Examples of the red colorant include those similar to the red colorant described as the compound (C3).

  As the compound (C5), since it becomes a photosensitive composition more excellent in resolution, C.I. I. At least one selected from the group consisting of CI Pigment Violet 23 and a diketopyrrolopyrrole red pigment is preferable.

Compound (C6)
Compound (C6) is a yellow colorant, and examples thereof include those similar to the yellow colorant described as the compound (C3). A yellow coloring agent can be used individually or in combination of 2 or more types.

  As the compound (C6), an isoindolinone-based pigment is preferable because it becomes a photosensitive composition with more excellent resolution, and C.I. I. Pigment Yellow 139 is more preferable.

  When the near-infrared light pass filter contains the compounds (C1) to (C3) in the above-described proportions, the compounds other than the compound (C1), the compound (C2) and the compound (C3) are within the range not impairing the effects of the present invention. Other colorants can also be used for the purpose of adjusting the transmission spectral shape. As the other colorant, either a pigment or a dye can be used, and the pigment may be either an organic pigment or an inorganic pigment. The dye may be either an organic dye or an inorganic dye. Other colorants can be used alone or in combination of two or more.

  When a near-infrared light pass filter contains the said compounds (C4)-(C6), the preferable content rate of a compound (C4)-(C6) is as follows. The content of the compound (C4) is preferably 20 to 70% by mass, more preferably 25 to 50% by mass, and still more preferably 30 to 45% by mass in the entire colorant. The content ratio of the compound (C5) is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and still more preferably 15 to 30% by mass in all the colorants. The content ratio of the compound (C6) is preferably 20 to 50% by mass, more preferably 25 to 45% by mass, and still more preferably 30 to 40% by mass in the entire colorant. Moreover, in the range which does not impair the effect of this invention, other coloring agents other than a compound (C4), a compound (C5), and a compound (C6) can also be used for the purpose of adjustment of a transmission spectrum shape.

  The average transmittance of the first optical layer when measured from the direction of oblique 30 degrees of the near infrared light in the wavelength band (X) and the oblique angle of 30 degrees of the near infrared light in the wavelength band (X) The product with the average transmittance of the near-infrared light pass filter when measured from the direction can be 25% or more. Thereby, the incident angle dependence of a solid-state imaging device can be reduced, and the malfunction that chromaticity changes with the imaging angles can be suppressed.

  The center wavelength of the wavelength band (X) is preferably in the range of 780 to 950 nm.

  According to the present invention, it is possible to realize a solid-state imaging device with high detection accuracy while suppressing manufacturing costs.

It is a conceptual diagram which shows the application example of the solid-state imaging device which concerns on 1st Embodiment of this invention. 1 is a plan view of a solid-state imaging device according to a first embodiment of the present invention. It is sectional drawing which shows the outline of the solid-state imaging device which concerns on 1st Embodiment of this invention. It is a figure which shows the transmission spectrum of the 1st optical layer used for the solid-state imaging device which concerns on 1st Embodiment of this invention. It is a figure which shows the transmission spectrum of the 2nd optical layer used for the solid-state imaging device which concerns on 1st Embodiment of this invention. It is a figure which shows the transmission spectrum of the near-infrared-light path filter used for the solid-state imaging device which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the relationship of the optical characteristic between a 1st optical layer and a near-infrared-light path filter. It is a figure which shows the result of having calculated the product of the average transmittance | permeability of a 1st optical layer, and the average transmittance | permeability of a near-infrared-light pass filter when near-infrared light is measured from a perpendicular direction. It is a figure which shows the transmission spectrum of the 1st optical layer when incident light is measured from the diagonal direction. It is a figure which shows the result of having calculated the product of the average transmittance | permeability of a 1st optical layer, and the average transmittance | permeability of a near-infrared-light pass filter when near-infrared light is measured from the diagonal direction. It is sectional drawing which shows the outline of the solid-state imaging device concerning 2nd Embodiment of this invention. It is the figure which showed the structure which measures a transmission spectrum from a perpendicular direction and the direction of diagonal 30 degree | times. It is a figure which shows the transmission spectrum of the 1st optical layer used for the solid-state imaging device which concerns on one Embodiment of this invention. It is a figure which shows the transmission spectrum of the 2nd optical layer used for the solid-state imaging device which concerns on one Embodiment of this invention. It is a figure which shows the transmission spectrum of the near-infrared-light pass filter used for the solid-state imaging device which concerns on one Embodiment of this invention.

  Hereinafter, a solid-state imaging device according to an embodiment of the present invention will be described in detail with reference to the drawings. The following embodiment is an example of the embodiment of the present invention, and the present invention is not limited to the embodiment described here.

  Note that in the drawings referred to in this embodiment, the same portion or a portion having a similar function is denoted by the same reference symbol or a similar reference symbol (a reference symbol simply including A, B, etc. after a number) and repeated. The description of may be omitted. In addition, the dimensional ratio in the drawing may be different from the actual ratio for convenience of explanation, or a part of the configuration may be omitted from the drawing.

  Further, in this specification, “up” refers to a relative position with respect to the main surface of the support substrate (surface on which the solid-state imaging device is disposed), and the direction away from the main surface of the support substrate is “up”. It is. In the drawings of the present application, the upper side toward the paper surface is “upper”. In addition, “upper” includes a case where it is in contact with an object (that is, “on”) and a case where it is located above the object (that is, “over”). Conversely, “down” refers to a relative position with respect to the main surface of the support substrate, and the direction approaching the main surface of the support substrate is “down”. In the drawings of the present application, the lower side is “down” toward the paper surface.

[Embodiment 1]
FIG. 1 is an application example of the solid-state imaging device according to the first embodiment of the present invention. Specifically, an example in which the solid-state imaging device of the present embodiment is applied to a TOF imaging device (for example, a distance image camera) is shown. Note that the imaging apparatus described here is merely a conceptual diagram, and does not prevent other elements from being added or deleted.

  In FIG. 1, an imaging device (camera) 10 includes a light source 11, a solid-state imaging device (image sensor) 12, a signal processing unit 13, and a main control unit 14 as basic components. The main control unit 14 is connected to the light source 11, the solid-state imaging device 12, and the signal processing unit 13, and plays a role of controlling each operation. The solid-state imaging device 12 is further connected to a signal processing unit 13 and transmits an electrical signal generated by the solid-state imaging device 12 to the signal processing unit 13.

  As the light source 11, a known LED (Light Emitting Diode) that outputs near-infrared light can be used. The near-infrared light output from the light source 11 strikes the imaging object 15 and is reflected, and the reflected light enters the solid-state imaging device 12. At this time, a phase difference corresponding to the three-dimensional shape of the imaging object 15 is generated between the near infrared light output from the light source 11 and the near infrared light returned from the imaging object 15.

  As the solid-state imaging device 12, a CMOS image sensor or a CCD image sensor can be used. As the CMOS image sensor, either a front-illuminated type or a back-illuminated type can be used, but in the present embodiment, a highly sensitive back-illuminated CMOS image sensor is used.

  External visible light reflected by the imaging object 15 and near-infrared light output from the light source 11 are incident on a solid-state imaging element (also referred to as a photoelectric conversion element or a sensor element) in the solid-state imaging device 12, depending on the amount of light. Converted into an electrical signal. The converted electrical signal is digitized by an AD conversion circuit provided in the solid-state imaging device 12 and output to the signal processing unit 13 as a digital signal. A specific structure of the solid-state imaging device 12 will be described later.

  The signal processing unit 13 receives the digital signal output from the solid-state imaging device 12, performs signal processing, and forms an image based on the imaging target 15. At this time, the digital signal based on the visible light is used as information for reproducing the color and shape of the imaging object 15, and the digital signal based on the near infrared light is information for recognizing the distance to the imaging object 15. Used as With these digital signals, the imaging object 15 can be grasped in three dimensions.

  The main control unit 14 is an arithmetic processing unit centering on the CPU, and controls the light source 11, the solid-state imaging device 12, and the signal processing unit 13, and is based on information obtained from the signal processing unit 13 and others not shown. The processing unit is also controlled.

  FIG. 2 is a plan view for explaining the outline of the solid-state imaging device 12. In the package 16, a pixel portion 17 and a terminal portion 18 are arranged. An AD conversion circuit may be provided between the pixel portion 17 and the terminal portion 18. The enlargement unit 19 shows a state in which a part of the pixel unit 17 is enlarged. As shown in the enlarged portion 19, a plurality of pixels 20 are arranged in a matrix in the pixel portion 17.

  FIG. 2 shows only a simple structure such as the pixel portion 17 and the terminal portion 18, but the solid-state imaging device of the present embodiment is not limited to this. For example, the function as the signal processing unit 13 shown in FIG. 1 can be incorporated in the solid-state imaging device 12 shown in FIG. Furthermore, it may be a system IC circuit that incorporates an arithmetic processing capability equivalent to that of the main control unit 14 shown in FIG.

(Structure of solid-state imaging device)
FIG. 3 is a cross-sectional view of the pixel 20 shown in FIG. 2 taken along line III-III ′. In FIG. 3, the first optical layer 21, the first gap 22, the microlens array 23, the second gap 24, the second optical layer 25, the third gap 26, the visible light path filter (from the side where the external light enters is shown. Color resist) 27a to 27c, a near-infrared light pass filter 27d, an insulator 28, photodiodes 29a to 29d, and a support substrate 30 are illustrated. The first gap 22, the second gap 24, and the third gap 26 may be secured as a space filled with air or an inert gas, or secured as an insulator composed of an organic insulating film or an inorganic insulating film. May be. The first gap 22, the second gap 24, or the third gap 26 may be omitted. For example, the second optical layer 25 and the visible light pass filters 27 a to 27 c may be in contact with each other, and the microlens array 23 may be in contact with the microlens array 23. The second optical layer 25 may be in contact.

  In the present specification, a pixel including the visible light pass filters 27a to 27c and the photodiodes 29a to 29c arranged corresponding to them is referred to as a “visible light detection pixel”, and the near infrared light pass filter 27d. The pixel composed of the photodiode 29d is referred to as a “near infrared light detection pixel”.

  Here, the first optical layer 21 is an optical layer that transmits at least part of visible light and near-infrared light. For example, visible light having a wavelength of 400 to 700 nm and at least part of a wavelength of 750 to 2500 nm (typically Transmits near-infrared light of 750 to 950 nm. Of course, the transmitted wavelength range is not limited to the range described here, but is detected by visible light corresponding to light of R (red), G (green) and B (blue) and a near infrared light detection pixel described later. What is necessary is just to be able to transmit near-infrared light in a possible wavelength range. Such a filter having an optical characteristic that transmits two different wavelength ranges is generally called a dual band pass filter.

  In the present embodiment, an optical layer in which a dielectric multilayer film is provided on a base material having a transparent resin (translucent resin) layer containing a compound having specific optical characteristics is used as the first optical layer 21. . Examples of the compound having specific optical characteristics include a compound that absorbs part of near-infrared light (hereinafter referred to as “compound (A)”). Specifically, at least one compound selected from the group consisting of a squarylium compound, a phthalocyanine compound, a naphthalocyanine compound, a croconium compound, a hexaphyrin compound, and a cyanine compound is used as the compound (A). Can do.

  Thus, by providing a dielectric multilayer film on a substrate having a transparent resin layer containing a compound that absorbs a portion of near infrared light, a dual that transmits at least a portion of visible light and near infrared light. It can be a band pass filter. At this time, the substrate may be a single layer or a multilayer. If it is a single layer, it can be set as the flexible base material comprised with a transparent resin layer. In the case of a multilayer, for example, a base material in which a transparent resin layer containing a compound (A) and a curable resin is laminated on a transparent substrate such as a glass substrate or a resin substrate, or a curable material on a transparent substrate containing a compound (A). A substrate on which a resin layer such as an overcoat layer containing a resin is laminated can be used.

  As described above, when the first optical layer 21 is formed of a resin base material, it is easier to make the first optical layer 21 thinner than a general dual bandpass filter, and for example, a film shape can be used. That is, when the dielectric multilayer film is laminated on the base material having the transparent resin layer containing the compound (A) described above, the thickness of the first optical layer 21 is, for example, 200 μm or less, preferably 180 μm or less. The thickness is preferably 150 μm or less, particularly preferably 120 μm or less.

  In the microlens array 23, the position of each microlens corresponds to the position of each pixel, and the incident light collected by each microlens corresponds to each corresponding pixel (specifically, each photodiode). Is received. Since the microlens array 23 can be formed using a resin material, it can also be formed on-chip. For example, the microlens array 23 may be formed by using an insulator as the second gap 24 and processing a resin material applied thereon. In addition, the second gap 24 is made of a base material (film) made of resin, the resin material applied thereon is processed to form the microlens array 23, and then the base material is pasted to form a solid image. It may be incorporated in the element 12.

  The second optical layer 25 is an optical layer that absorbs at least part of near-infrared light, and includes, for example, a compound having an absorption maximum at a wavelength of 750 to 2000 nm (hereinafter referred to as “compound (B)”). Examples of the compound (B) include diiminium compounds, squarylium compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, quaterylene compounds, aminium compounds, iminium compounds, azo compounds, anthraquinone compounds, Use at least one compound selected from the group consisting of porphyrin compounds, pyrrolopyrrole compounds, oxonol compounds, croconium compounds, hexaphyrin compounds, metal dithiol compounds, copper compounds, tungsten compounds, and metal borides. Can do. The second optical layer 25 functions as a near-infrared light cut filter that absorbs part of the near-infrared light according to the optical characteristics of the compound (B).

  The second optical layer 25 has an opening at a portion corresponding to the near-infrared light detection pixel (specifically, the photodiode 29d). That is, an opening is provided above the photodiode 29d so that the near-infrared light reaches the photodiode 29d as it is, and has a structure that does not prevent near-infrared light from entering. In other words, the “part corresponding to the photodiode 29 d” in the second optical layer 25 means that the second optical layer 25 intersects the optical path of near infrared light directed above the photodiode 29 d, that is, toward the photodiode 29 d. Refers to the part.

  As described above, the second optical layer 25 is arranged so as to cover the portion other than the near-infrared light detection pixel (that is, the visible light detection pixel). Thereby, it is possible to suppress the near infrared light from reaching the visible light detection pixels as much as possible. As a result, noise components can be reduced in the visible light detection pixels, and the detection accuracy of visible light can be improved.

  Below the second optical layer 25, a pixel group including the above-described visible light detection pixels and near-infrared light detection pixels is disposed. As described above, in the present embodiment, the photodiodes 29a to 29c and the visible light pass filters 27a to 27c correspond to each other to form a visible light detection pixel. The photodiode 29d and the near-infrared light pass filter 27d correspond to each other to form a near-infrared light detection pixel. In the present specification, the photodiodes 29a to 29c are referred to as “first light receiving elements”, and the photodiode 29d is referred to as a “second light receiving element”.

  Actually, the visible light pass filters 27a to 27c are constituted by pass filters that transmit visible light having different wavelengths. For example, the visible light pass filter may include a pass filter 27a that transmits green light, a pass filter 27b that transmits red light, and a pass filter 27c that transmits blue light. Therefore, the pixels corresponding to these individual colors may be called green light detection pixels, red light detection pixels, and blue light detection pixels, respectively.

  The visible light pass filters 27a to 27c and the near-infrared light pass filter 27d can be formed using a curable composition containing a coloring matter (pigment or dye) having absorption at a specific wavelength. For example, the visible light pass filters 27a to 27c can be formed using a curable composition containing the compound (B) and at least one selected from a binder resin and a polymerizable compound. The near-infrared light pass filter 27d includes a compound (C) having an absorption maximum in a visible light wavelength region (typically a wavelength of 430 to 620 nm), and at least one selected from a binder resin and a polymerizable compound. It can form using the curable composition containing. As the compound (B) and the compound (C), those described above can be used. One or more compounds (C) having absorption in the visible light wavelength region may be contained, but a plurality of compounds (C) may be combined.

  Typically, as the compound (C), a colorant containing the above-described compounds (C1) to (C6) can be used. Moreover, a well-known thing is employable as binder resin and a polymeric compound. Specifically, as binder resin, paragraphs [0095] to [0148] of JP2012-189632A, paragraphs [0179] to [0210] of JP2013-077009A, JP2013-137337A. Paragraphs [0134] to [0157], paragraphs [0150] to [0165] of JP2013-151675A, paragraphs [0072] to [0079] of JP2014-130332A Can be adopted. As polymerizable compounds, paragraphs [0054] to [0094] of JP2012-189632A, paragraphs [0122] to [0155] of JP2013-077009A, paragraphs of JP2013-137337A [ 0054] to [0089], paragraphs [0066] to [0107] of JP 2013-151675 A, paragraphs [0052] to [0056] of JP 2014-130332 A, and the like. Can do.

  The curable composition may further contain a photopolymerization initiator and a solvent. Known photopolymerization initiators and solvents can be used. Specifically, as photopolymerization initiators, paragraphs [0039] to [0053] of JP2012-189632A, paragraphs [0071] to [0121] of JP2013-077009A, JP2013-137337A. Paragraphs [0093] to [0133] of Japanese Patent Publication No. 2013, paragraphs [0108] to [0149] of Japanese Unexamined Patent Publication No. 2013-151675, and paragraphs [0057] to [0065] of Japanese Unexamined Patent Publication No. 2014-130332. Things can be adopted. As the solvent, paragraphs [0227] of JP2012-189632, paragraphs [0211] to [0213] of JP2013-077009, paragraph [0090] of JP2013-137337, JP2013. Those described in paragraph [0249] of JP-A No. 151151675 and paragraphs [0065] to [0071] of JP 2014-130332 A can be employed.

  The near-infrared light pass filter 27d can also be formed by providing a layer containing a dye having absorption at a specific wavelength on the substrate.

  The photodiodes 29a to 29d described above can be formed using a silicon substrate as the support substrate 30 and using a known semiconductor process on the surface of the silicon substrate. Of course, it is also possible to form the photodiodes 29a to 29d using a known thin film forming technique using a substrate such as glass, ceramics, or resin as the support substrate 30.

  In the present embodiment, the photodiode 29a is used as a light receiving element for receiving green light having a wavelength of 520 to 560 nm, the photodiode 29b is used as a light receiving element for receiving red light having a wavelength of 580 to 620 nm, and the photodiode 29c is used. Is used as a light receiving element for receiving blue light having a wavelength of 430 to 470 nm. Thus, in the solid-state imaging device 12 of the present embodiment, visible light incident from the outside is detected using these photodiodes 29a to 29c.

  On the other hand, the photodiode 29d functions as a light receiving element for receiving near-infrared light having a wavelength of 750 to 2500 nm (typically, wavelength of 750 to 950 nm), and near-infrared light incident from the outside by the photodiode 29d. Is detected.

(Method for manufacturing solid-state imaging device)
An example of a method for manufacturing the solid-state imaging device 20 will be described with reference to FIG. First, a silicon substrate is prepared as the support substrate 30, and the photodiodes 29a to 29d are formed using a known semiconductor process. For example, an n-type region is formed by adding an n-type impurity such as phosphorus to a silicon substrate, and a p-type region is formed by adding a p-type impurity such as boron therein, thereby obtaining a pn junction. . Then, the photodiodes 29a to 29d can be formed by forming a wiring so that current can be taken out from the n-type region and the p-type region.

  After the photodiodes 29a to 29d are formed, the insulator 28 is formed by CVD (Chemical Vapor Deposition) or the like to cover the photodiodes 29a to 29d. As the insulator 28, an inorganic insulating layer containing silicon oxide or the like, or an organic insulating layer containing a resin can be used. At that time, it is preferable to set the film thickness so that the undulation caused by the photodiodes 29a to 29d can be flattened.

  After the insulator 28 is formed, visible light pass filters 27a to 27c are formed. The visible light pass filters 27a to 27c form, for example, a structure composed of a curable composition containing a curable component containing a dye that absorbs light of a specific wavelength at a desired position using a printing method. Can be obtained.

  Next, a light-transmitting insulating layer is formed as the gap 26 on the visible light pass filters 27a to 27d. For example, a silicon oxide layer or an organic resin layer can be formed as the light-transmitting insulating layer. Note that in the case where an insulating layer having a light-transmitting property is used as the gap 26, unevenness caused by the visible light pass filters 27a to 27d can be flattened. Therefore, the second optical layer 25 formed on the gap 26 can be made flat, and the uniformity of the optical characteristics of the second optical layer 25 can be improved.

  After the silicon oxide layer is formed as the gap 26, the second optical layer 25 is formed. As the 2nd optical layer 25, the curable resin composition containing the above-mentioned compound (B) is used. For example, the second optical layer 25 is formed by applying a curable resin composition containing the compound (B) by spin coating. In addition, what is necessary is just to form an opening part in the part corresponding to the near-infrared-light pass filter 27d using well-known photolithography.

  Next, an insulating layer having translucency is formed again as the gap 24 on the second optical layer 25. Also in this case, for example, a silicon oxide layer or an organic resin layer can be formed as the light-transmitting insulating layer. Further, when a light-transmitting insulating layer is used as the gap 24, the undulation caused by the opening provided in the second optical layer 25 can be flattened.

  When a light-transmitting insulating layer is formed as the gap 24, the microlens array 23 is formed so as to correspond to the photodiodes 29a to 29d. The microlens array 23 can be bonded to an existing microlens array, but can also be formed by processing a resin layer. For example, a resin layer can be applied and cured by spin coating or the like, and then processed by dry etching or the like while masking a desired region to form a plurality of lens-shaped structures.

  When the microlens array 23 is formed, a resin layer is formed as the gap 22, and the first optical layer 21 is bonded thereon. For example, a resin material is applied by spin coating or the like, the already formed first optical layer 21 is disposed thereon, and the resin material is cured in that state. Accordingly, the first optical layer 21 can be bonded using the resin layer formed as the gap 22. Of course, after the resin layer is cured, the first optical layer 21 may be bonded using an adhesive.

  The solid-state imaging device 20 shown in FIG. 3 can be formed by the procedure as described above. Note that the manufacturing method described here is merely an example, and an appropriate alternative technique may be used for a material to be used and a film forming method.

  Here, the optical characteristics of the first optical layer 21, the second optical layer 25, and the near-infrared light pass filter 27d used in the solid-state imaging device 12 of the present embodiment are shown in FIGS.

  FIG. 4 is a diagram showing a transmission spectrum of the first optical layer (dual bandpass filter) 21 used in the solid-state imaging device 12 of the present embodiment. In FIG. 4, the horizontal axis indicates the wavelength of incident light, and the vertical axis indicates the transmittance when measured from the direction perpendicular to the first optical layer 21 as a percentage. As shown in FIG. 4, the first optical layer 21 used in this embodiment has optical characteristics that transmit visible light having a wavelength of 400 to 700 nm and near infrared light having a wavelength of 750 to 950 nm. . Of course, the optical characteristics shown in FIG. 4 are merely examples, and the first optical layer 21 used in the present embodiment is not limited as long as it has optical characteristics that transmit at least part of visible light and near infrared light. Even a dual band-pass filter that transmits through the wavelength region can be used.

  FIG. 5 is a diagram showing a transmission spectrum of the second optical layer (near infrared light cut filter) 25 used in the solid-state imaging device 12 of the present embodiment. In FIG. 5, the horizontal axis indicates the wavelength of incident light, and the vertical axis indicates the transmittance when measured from the direction perpendicular to the second optical layer 25 as a percentage. FIG. 5 shows two types of the second optical layer (A) and the second optical layer (B), but the difference in the transmission spectrum between them is due to the difference in the compound (B) contained. . Specifically, the second optical layer (A) contains a cyanine compound having a maximum absorption maximum wavelength of 865 nm, and the second optical layer (B) includes a cyanine compound having a maximum absorption maximum wavelength of 865 nm and It contains a cyanine compound having the same wavelength of 810 nm.

  As shown in FIG. 5, the second optical layer 25 used in this embodiment has a function of cutting incident light having a wavelength of approximately 600 to 950 nm. Of course, the optical characteristic shown in FIG. 5 is an example, and as the second optical layer 25 used in the present embodiment, an optical layer containing a compound (B) having an absorption maximum at a wavelength of 750 to 2000 nm may be used.

  FIG. 6 is a diagram showing a transmission spectrum of the near-infrared light pass filter 27d used in the solid-state imaging device 12 of the present embodiment. In FIG. 6, the horizontal axis indicates the wavelength of the incident light, and the vertical axis indicates the transmittance when measured from the direction perpendicular to the near-infrared light pass filter 27d in percentage.

  As shown in FIG. 6, the near-infrared light pass filter 27d used in the present embodiment has a characteristic of transmitting light having a wavelength longer than that near the wavelength of 800 nm. Of course, the near-infrared light pass filter 27d that can be used in this embodiment is not limited to the one having the transmission spectrum characteristics shown in FIG. That is, since the compound (C) having an absorption maximum at a wavelength of 430 to 620 nm is included as described above, the absorption edge may be on the longer wavelength side or the shorter wavelength side.

  In the solid-state imaging device 12 according to the present embodiment, first, external light is filtered by the first optical layer 21 having the optical characteristics shown in FIG. It transmits at least part of the external light (specifically, near infrared light having a wavelength of 750 to 950 nm). A part of visible light and near infrared light transmitted through the first optical layer 21 is incident on the second optical layer 25.

  At this time, since the second optical layer 25 above the photodiode 29d is provided with an opening, a part of the visible light and the near infrared light transmitted through the first optical layer 21 is not changed. The light enters the pass filter 27d. In the near-infrared light pass filter 27d, as shown in FIG. 6, visible light having a wavelength of approximately 750 nm or less is absorbed (cut), and near-infrared light having a wavelength of 750 to 950 nm is incident on the photodiode 29d. Thereby, in the near-infrared light detection pixel, it is possible to accurately grasp the distance to the imaging target 15 without being affected by noise or the like caused by visible light.

  On the other hand, since the second optical layer 25 is provided above the photodiodes 29a to 29c (above the visible light pass filters 27a to 27c), visible light and near infrared light transmitted through the first optical layer 21 are provided. A part of the light enters the second optical layer 25. In the second optical layer 25, as shown in FIG. 5, near-infrared light having a wavelength of approximately 800 to 900 nm is absorbed (cut), and visible light including RGB component light passes through the visible light path filters 27a to 27c. Through the photodiodes 29a to 29c. As a result, the amount of near-infrared light incident on the photodiodes 29a to 29c can be greatly reduced. Therefore, in the visible light detection pixel, the influence of noise and the like caused by infrared light is suppressed, and more It is possible to grasp the chromaticity and shape of the imaged object 15 with high accuracy.

  As described above, in the solid-state imaging device 12 according to the present embodiment, by appropriately adjusting the optical characteristics of the first optical layer 21 and the second optical layer 25, the near-infrared light finally incident on the visible light detection pixel. Light can be suppressed. Furthermore, by appropriately adjusting the optical characteristics of the first optical layer 21 and the near-infrared light pass filter 27d, visible light that finally enters the near-infrared light detection pixel is suppressed, and the near-infrared light Sensitivity can be increased.

  In addition, when the first optical layer 21 is not provided and only the second optical layer 25 is provided, color reproducibility and sensing performance may be deteriorated in the visible light detection pixels. For example, in general, a color resist for red has an optical characteristic of transmitting light having a wavelength of 600 nm or more. Therefore, even if a portion of near-infrared light is cut by the second optical layer 25, a near color having a wavelength of 950 nm or more is used. Infrared light may enter the red light detection pixel. In general, since the color resist for green and the color resist for blue have optical characteristics in which the transmittance gradually increases from around the wavelength of 750 nm, near infrared light having a wavelength of 950 nm or more is also used for detecting green light. There is a risk of entering the pixel or the blue light detection pixel. The merit of using the first optical layer 21 and the second optical layer 25 together is that these problems can be avoided.

  FIG. 7 is a diagram for explaining the relationship of optical characteristics between the first optical layer 21 and the near-infrared light pass filter 27d. FIG. 7 shows a curve 701 indicating the optical characteristics of the first optical layer 21 (transmission spectrum in the incident light in the vertical direction) and the optical characteristics (transmission spectrum in the incident light in the vertical direction) of the near-infrared light pass filter 27d. Curve 702 is shown. These curves 701 and 702 correspond to the transmission spectra shown in FIGS. 4 and 6, respectively.

  In the curve 701 shown in FIG. 7, when the transmittance of near infrared light having a wavelength of 750 to 950 nm is measured from the vertical direction, the shortest wavelength that is 30% or more is X1, and the transmittance is the most that the transmittance is 30% or less. Let X2 be the long wavelength. A wavelength band (wavelength range) from the wavelength X1 to the wavelength X2 is X.

  At this time, the solid-state imaging device 12 according to the present embodiment has the same wavelength band (X) as the average transmittance of the first optical layer 21 when measured from the vertical direction of near-infrared light in the wavelength band (X) described above. The product of the average transmittance of the near-infrared light pass filter 27d when measured from the vertical direction of the near-infrared light is 30% or more (preferably 40% or more, more preferably 50% or more, particularly preferably 60% or more). ), The optical characteristics of the first optical layer 21 and the near-infrared light pass filter 27d are adjusted.

  For example, the average transmittance of the first optical layer 21 when measured from the vertical direction of near infrared light in the wavelength band (X) is 80%, and from the vertical direction of near infrared light in the same wavelength band (X). When the average transmittance of the near-infrared light pass filter 27d when measured is 85%, the product of both is 68% (that is, 0.8 × 0.85 = 0.68). In other words, by appropriately designing the control of the amount of near-infrared light that passes through the first optical layer 21 and the amount of near-infrared light that passes through the near-infrared light pass filter 27d, the photodiode 29d is finally designed. The amount of the near-infrared light reaching can be 30% or more (preferably 40% or more, more preferably 50% or more, particularly preferably 60% or more) of the incident near-infrared light. Thereby, the sensing sensitivity of the photodiode 29d can be improved.

  Furthermore, the solid-state imaging device 12 according to the present embodiment is a case where the solid-state imaging device 12 is measured from the vertical direction in the same wavelength region as the average transmittance of the first optical layer 21 when measured from the vertical direction in the visible light region (wavelength 430 nm to 620 nm). The first optical layer 21 and the first optical layer 21 so that the product of the average transmittance of the near-infrared light pass filter 27d is 30% or less (preferably 20% or less, more preferably 10% or less, particularly preferably 5% or less). The optical characteristics of the near infrared light pass filter 27d are adjusted. That is, the amount of visible light having a wavelength of 430 nm to 620 nm finally reaching the photodiode 29d is 30% or less (preferably 20% or less, more preferably 10% or less, particularly preferably 5% or less) of incident visible light. ). Thereby, visible light incident on the photodiode 29d can be reduced, and malfunction of the sensing function can be prevented.

  As described above, according to the present embodiment, by adjusting the balance of the optical characteristics (transmittance with respect to near infrared light) of the first optical layer 21 and the near infrared light pass filter 27d, the second light reception is finally achieved. The amount of near-infrared light reaching the element 29d can be controlled. For example, even if the near-infrared light pass filter 27d has a low transmittance to the near-infrared light, the transmittance of the first optical layer 21 to the near-infrared light may be increased to compensate for it. However, when the first optical layer 21 is not provided (theoretically, the transmittance of the first optical layer 21 is 100%), as described above, the color reproducibility and sensing performance deteriorate in the visible light detection pixel. There is a risk. Therefore, it can be said that it is very meaningful to adjust the balance of the optical characteristics of the first optical layer 21 and the near-infrared light pass filter 27d.

  FIG. 8 is a diagram showing the result of calculating the product of the average transmittance of the first optical layer and the average transmittance of the near-infrared light pass filter when near-infrared light is measured from the vertical direction. Specifically, each transmittance in the wavelength band (X) in the transmission spectrum indicated by the curve 701 in FIG. 7 is multiplied by each transmittance in the wavelength band (X) in the transmission spectrum indicated by the curve 702. The calculation results are shown.

  As is clear from FIG. 8, the transmittance is maximum in the wavelength range of 800 to 950 nm, indicating about 87%. This means that when the first optical layer 21 and the near-infrared light pass filter 27 are viewed as one optical layer, 80% or more of the emitted light is transmitted with respect to the incident light. That is, the near-infrared light transmitted through the first optical layer 21 is incident on the near-infrared light detection pixel with almost no absorption by the near-infrared light pass filter 27. Moreover, it turns out that the transmittance | permeability is about 5% or less in visible light region (wavelength 430nm -620nm). That is, the visible light having a wavelength of 430 nm to 620 nm transmitted through the first optical layer 21 is almost absorbed by the near infrared light pass filter 27 and hardly incident on the near infrared light detection pixel.

  In this way, by using the first optical layer 21 and the near-infrared light 27 in combination and adjusting the optical characteristics of the two so as to satisfy the above-described conditions, the visible light detection pixel and the near-infrared light detection are performed. Visible light and near-infrared light can be selectively incident on each pixel. As a result, a solid-state imaging device with high detection accuracy can be realized.

  Further, unlike the conventional example, it is not necessary to separately arrange both a visible light pass filter and an infrared pass filter above the visible light detection pixel and the infrared light detection pixel, and the detection accuracy is high while suppressing the manufacturing cost. A solid-state imaging device can be realized.

  In the present embodiment, the shortest wavelength at which the transmittance of near infrared light having a wavelength of 750 to 950 nm is 30% or more when measured from the vertical direction is X1, and the transmittance is the longest at 30% or less. A reference wavelength band (X) was determined with the wavelength as X2. However, the wavelength band (X) can be arbitrarily determined. For example, when the transmittance of near-infrared light is measured from the vertical direction, the shortest wavelength that is 40% or more is X1, and the transmittance is 40. It is also possible to determine using an arbitrary transmittance, for example, to determine a reference wavelength band (X) with X2 being the longest wavelength that is less than or equal to%. In that case, the center wavelength of the wavelength band (X) is preferably in the range of 780 to 950 nm. This is because the wavelength of 780 to 950 nm includes a wavelength range in which the photodiode 29d (second light receiving element) formed on the silicon substrate can be detected with high accuracy.

  The average transmittance of the first optical layer 21 when measured from the vertical direction of near-infrared light in the wavelength band (X) is 50% or more (preferably 60% or more, more preferably 65% or more). Is desirable. Increasing the amount of near-infrared light transmitted through the first optical layer 21 as much as possible leads to an increase in the amount of received light in the near-infrared light detection pixel, and contributes to the improvement of the detection accuracy of the distance to the imaging target 15. Because.

  The average transmittance of the first optical layer 21 when measured from the vertical direction of visible light at a wavelength of 430 nm to 620 nm is desirably 60% or more (preferably 70% or more, more preferably 80% or more). Increasing not only near-infrared light but also visible light transmitted through the first optical layer 21 as much as possible leads to an increase in the amount of received light in the visible light detection pixels, and improves the color reproducibility of the imaging object 15. This is because it contributes.

  Furthermore, the average transmittance of the second optical layer when measured from the vertical direction of the transmitted light in the same wavelength region as the average transmittance of the first optical layer 21 when measured from the vertical direction of the transmitted light at a wavelength of 430 to 620 nm; It is desirable that the product of is 65% or more. That is, it is desirable to maintain the relationship between the optical characteristics described with reference to FIG. 7 while maintaining high visible light transmittance in both the first optical layer 21 and the second optical layer 25. Accordingly, it is possible to ensure the detection accuracy of the visible light detection pixel at a high level while ensuring the detection accuracy of the near-infrared light detection pixel.

  Such a relationship may be established for light having wavelengths corresponding to RGB colors. That is, the product of the average transmittance of the first optical layer 21 and the average transmittance of the second optical layer is 60% or more at a wavelength of 430 to 470 nm (preferably under the condition of measuring from the vertical direction of transmitted light (preferably 70% or more), 75% or more (preferably 80% or more) at a wavelength of 520 to 560 nm, and 70% or more (preferably 75% or more) at a wavelength of 580 to 620 nm.

  In the solid-state imaging device 12 described above, the transmittance is measured based on light incident from the vertical direction on the first optical layer 21, the second optical layer 25, and the near-infrared light pass filter 27. When the light enters from the transmission spectrum, the transmission spectrum tends to shift. However, the solid-state imaging device 12 of the present embodiment maintains the above-described optical characteristic relationship described with reference to FIG. 7 even when the transmission spectrum is shifted as described above.

  FIG. 9 is a diagram showing a transmission spectrum of the first optical layer (dual bandpass filter) 21 used in the solid-state imaging device 12 of the present embodiment. However, in FIG. 9, the horizontal axis indicates the wavelength of incident light, and the vertical axis is measured from a direction of 0 degree (vertical direction), an oblique direction of 20 degrees, and an oblique direction of 30 degrees with respect to the first optical layer 21. In this case, the transmittance is shown as a percentage. As shown in FIG. 9, the optical characteristics of the first optical layer 21 tend to shift the transmission spectrum depending on the incident angle of incident light.

  FIG. 10 is a diagram showing the result of calculating the product of the average transmittance of the first optical layer and the average transmittance of the near-infrared light pass filter when near-infrared light is measured from a direction of 30 degrees obliquely. is there. As shown in FIG. 10, even in this case, the transmittance becomes maximum in the wavelength range of 800 to 950 nm, indicating about 80%. That is, even if the near infrared light is incident obliquely and the transmission spectrum of the first optical layer 21 is shifted to the short wavelength side, in the present embodiment, a sufficient amount of near infrared light is transmitted to the second light receiving element 29d. Can be reached. As described above, according to the solid-state imaging device 12 of the present embodiment, it is possible to realize a solid-state imaging device with high detection accuracy while suppressing the dependency on the incident angle.

[Embodiment 2]
FIG. 11 is a cross-sectional view of the pixel 40 in the solid-state imaging device according to the second embodiment. The difference between the cross-sectional view shown in FIG. 11 and the cross-sectional view of the pixel 20 shown in FIG. 3 is that the second optical layer 25 and the third gap 26 are omitted in this embodiment. . Other configurations are the same as those in the cross-sectional view shown in FIG. 3, and the same reference numerals are used. The optical characteristics of the first optical layer 21, the visible light pass filters 27a to 27c, and the near-infrared light pass filter 27d are the same as those in the first embodiment.

  In the case of this embodiment, a part of near infrared light is incident on the visible light detection pixel. However, by controlling the material and film thickness of the semiconductor layers of the photodiodes 29a to 29c, a structure in which near-infrared light is hardly absorbed can be obtained. For example, if the semiconductor layers constituting the photodiodes 29a to 29c are silicon, absorption of near-infrared light can be suppressed by sufficiently reducing the film thickness. However, since the detection sensitivity of visible light (especially red light on the long wavelength side) may be lowered by reducing the film thickness, attention must be paid to this point.

  Further, by omitting the second optical layer 25, one of the second gap 24 and the third gap 26 can be omitted. FIG. 11 shows an example in which the third gap 26 is omitted. Thereby, it is possible to reduce the thickness of the whole solid-state imaging device.

  According to this embodiment, since the second optical layer 25 can be omitted, in addition to the effect provided by the solid-state imaging device of the first embodiment, the thickness of the entire solid-state imaging device can be suppressed, and the manufacturing process can be performed. There is an effect that simplification of the above becomes possible.

[Embodiment 3]
The optical filter of the present invention includes a first optical layer that transmits at least part of visible light and near infrared light, and near red that absorbs at least part of visible light and transmits at least part of near infrared light. And an external light path filter. As an embodiment thereof, for example, an optical filter in which the first optical layer and the near-infrared light path filter described above are bonded together, or an optical in which the first optical layer and the near-infrared light path filter are bonded through a transparent substrate. A filter can be exemplified. That is, the optical filter according to the present embodiment includes a first optical layer that transmits at least part of visible light and near infrared light, and at least part of visible light that absorbs at least part of near infrared light. There is no particular limitation as long as it includes a transmitting near-infrared light path filter.

[Example]

  Hereinafter, the first optical layer, the second optical layer, and the near-infrared light pass filter shown in the above embodiment will be described more specifically based on examples. However, the above embodiment is not limited to these examples. It is not something. “Parts” means “parts by weight” unless otherwise specified. Moreover, the measurement method of each physical property value and the evaluation method of the physical property are as follows.

<Molecular weight>
The molecular weight of the resin was measured by the following method in consideration of the solubility of each resin in a solvent.

  Using a gel permeation chromatography (GPC) apparatus manufactured by WATERS (150C type, column: H type column manufactured by Tosoh Corporation, developing solvent: o-dichlorobenzene), the weight average molecular weight in terms of standard polystyrene ( Mw) and number average molecular weight (Mn) were measured.

<Glass transition temperature (Tg)>
Using a differential scanning calorimeter (DSC6200) manufactured by SII Nano Technologies, Inc., the rate of temperature increase was measured at 20 ° C. per minute under a nitrogen stream.

<Spectral transmittance>
The transmittance of each wavelength region of the first optical layer (X1) and (X2) and the first optical layer was measured using a spectrophotometer (U-4100) manufactured by Hitachi High-Technologies Corporation.

  Here, with respect to the transmittance when measured from the vertical direction of the first optical layer and the second optical layer, light transmitted perpendicularly to the filter was measured as shown in FIG. Further, with respect to the transmittance when measured from an angle of 30 ° with respect to the vertical direction of the optical filter, light transmitted at an angle of 30 ° with respect to the vertical direction of the filter was measured as shown in FIG.

[Synthesis example]
The compound (A) used in the above embodiment can be synthesized by a generally known method. For example, Japanese Patent No. 3366697, Japanese Patent No. 2846091, Japanese Patent No. 2864475, Japanese Patent No. 3094037, Patent No. 3703869, Japanese Patent Application Laid-Open No. 60-228448, Japanese Patent Application Laid-Open No. 1-146846, Japanese Patent Application Laid-Open No. 1-222860, Japanese Patent No. 4081149, Japanese Patent Application Laid-Open No. 63-122404, “Phthalocyanine -Chemistry and Function (IPC, 1997), Japanese Patent Application Laid-Open No. 2007-169315, Japanese Patent Application Laid-Open No. 2009-108267, Japanese Patent Application Laid-Open No. 2010-241873, Japanese Patent No. 3699464, Japanese Patent No. 4740631, and the like. It can be synthesized by reference.

<Resin Synthesis Example 1 Related to Compound (A)>
8-methyl-8-methoxycarbonyltetracyclo represented by the following formula (a) [4.4.0.1 ^2,5 . 1 ^7,10 ] 100 parts of dodec-3-ene, 18 parts of 1-hexene (molecular weight regulator) and 300 parts of toluene (solvent for ring-opening polymerization reaction) were charged into a nitrogen-substituted reaction vessel, and this solution was heated to 80 ° C. Heated. Next, 0.2 parts of a toluene solution of triethylaluminum (concentration 0.6 mol / liter) and a toluene solution of methanol-modified tungsten hexachloride (concentration 0.025 mol / liter) 0 as a polymerization catalyst were added to the solution in the reaction vessel. 9 parts was added, and the resulting solution was heated and stirred at 80 ° C. for 3 hours to cause a ring-opening polymerization reaction to obtain a ring-opening polymer solution. The polymerization conversion rate in this polymerization reaction was 97%.

1,000 parts of the ring-opening polymer solution thus obtained was charged into an autoclave, and 0.12 part of RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ was added to the ring-opening polymer solution. Then, the hydrogenation reaction was performed by heating and stirring for 3 hours under the conditions of a hydrogen gas pressure of 100 kg / cm ² and a reaction temperature of 165 ° C. After cooling the obtained reaction solution (hydrogenated polymer solution), the hydrogen gas was released. This reaction solution was poured into a large amount of methanol to separate and recover the coagulated product, and dried to obtain a hydrogenated polymer (hereinafter also referred to as “resin A”). The obtained resin A had a number average molecular weight (Mn) of 32,000, a weight average molecular weight (Mw) of 137,000, and a glass transition temperature (Tg) of 165 ° C.

<Preparation of the first optical layer>
In this example, an optical filter having a base made of a transparent resin substrate having resin layers on both sides as the first optical layer and having a near infrared selective transmission band in the vicinity of a wavelength of 810 to 900 nm was prepared. In a container, 100 parts of resin A obtained in Resin Synthesis Example 1, 0.03 part of compound (a-1: absorption maximum wavelength 698 nm in dichloromethane) having the following structure as compound (A), (a-2: dichloromethane) In addition, 0.05 part of (maximum absorption wavelength 738 nm), 0.03 part (a-3: absorption maximum wavelength 770 nm in dichloromethane) and methylene chloride were added to obtain a solution having a resin concentration of 20% by weight. Subsequently, the obtained solution was cast on a smooth glass plate, dried at 20 ° C. for 8 hours, and then peeled off from the glass plate. The peeled coating film was further dried at 100 ° C. under reduced pressure for 8 hours to obtain a base material composed of a transparent resin substrate having a thickness of 0.1 mm, a length of 60 mm, and a width of 60 mm.

（ａ−１）

（ａ−２）

（ａ−３）

(A-1)

(A-2)

(A-3)

A resin composition (1) having the following composition was applied to one side of the obtained transparent resin substrate with a bar coater and heated in an oven at 70 ° C. for 2 minutes to volatilize and remove the solvent. At this time, the coating conditions of the bar coater were adjusted so that the thickness after drying was 2 μm. Next, it exposed using the conveyor type exposure machine (exposure amount 500mJ / cm < ² >, 200mW), the resin composition (1) was hardened, and the resin layer was formed on the substrate made from transparent resin. Similarly, a resin layer made of the resin composition (1) was formed on the other surface of the transparent resin substrate, and a base material having a resin layer on both surfaces of the transparent resin substrate containing the compound (A) was obtained. .

  Resin composition (1): 60 parts by weight of tricyclodecane dimethanol acrylate, 40 parts by weight of dipentaerythritol hexaacrylate, 5 parts by weight of 1-hydroxycyclohexyl phenyl ketone, methyl ethyl ketone (solvent, solid content concentration (TSC): 30%)

Subsequently, the dielectric multilayer film (I) is formed on one surface of the obtained base material, and the dielectric multilayer film (II) is further formed on the other surface of the base material, so that the optical thickness is about 0.109 mm. A filter was obtained.
The dielectric multilayer film (I) is formed by alternately laminating silica (SiO ₂ ) layers and titania (TiO ₂ ) layers at a deposition temperature of 100 ° C. (26 layers in total). The dielectric multilayer film (II) is formed by alternately laminating silica (SiO ₂ ) layers and titania (TiO ₂ ) layers at a deposition temperature of 100 ° C. (20 layers in total). In both of the dielectric multilayer films (I) and (II), the silica layer and the titania layer are arranged in the order of the titania layer, the silica layer, the titania layer,... The outermost layer of the optical filter was a silica layer.

The dielectric multilayer films (I) and (II) were designed as follows. Regarding the thickness and number of layers, the wavelength dependence of the refractive index of the base material and the absorption characteristics of the compound (A) used so that the antireflection effect in the visible region and the selective transmission / reflection performance in the near infrared region can be achieved. Was optimized using optical thin film design software (Essential Macleod, manufactured by Thin Film Center). When performing optimization, in this example, the input parameters (Target values) to the software are as shown in Table 1 below.

  As a result of the optimization of the film configuration, in the present example, the dielectric multilayer film (I) is formed by alternately stacking a silica layer having a film thickness of 19 to 387 nm and a titania layer having a film thickness of 8 to 99 nm. The dielectric multilayer film (II) is a multilayer deposited film having 20 layers, in which a silica layer having a thickness of 31 to 191 nm and a titania layer having a thickness of 19 to 126 nm are alternately stacked. It was. Table 2 shows an example of the optimized film configuration.

  The spectral transmittance and reflectance of this optical filter were measured, and the optical characteristics in each wavelength region were evaluated. As a result of evaluation, in this example, (X1) is 812 nm, (X2) is 904 nm, the center wavelength of the wavelength band (X) is 858 nm, and the average transmittance is 73 when measured from the vertical direction in the wavelength band (X). %, The average transmittance when measured from an oblique direction of 30 degrees in the wavelength band (X) is 45%, the average transmittance when measured from the vertical direction at a wavelength of 430 to 620 nm is 85%, and the vertical transmittance at a wavelength of 430 to 470 nm The average transmittance when measured from the direction is 82%, the average transmittance when measured from the vertical direction at wavelengths of 520 to 560 nm is 88%, and the average transmittance when measured from the vertical direction at wavelengths of 580 to 620 nm is 79%. Thus, it was confirmed that the film has excellent transmission characteristics in the visible region and some near-infrared wavelength bands. A spectrum obtained by the measurement is shown in FIG.

<Resin Synthesis Example 2 Related to Compound (B)>
In a reaction vessel, 14 g of benzyl methacrylate, 12 g of N-phenylmaleimide, 15 g of 2-hydroxyethyl methacrylate, 10 g of styrene and 20 g of methacrylic acid are dissolved in 200 g of propylene glycol monomethyl ether acetate, and further 3 g of 2,2′-azoisobutyronitrile. And 5 g of α-methylstyrene dimer was added. After purging the inside of the reaction vessel with nitrogen, it was heated at 80 ° C. for 5 hours with stirring and nitrogen bubbling to obtain a solution containing a binder resin (hereinafter, binder resin solution (P) solid content concentration 35 mass%). About the obtained binder resin, Showa Denko Corporation Gel Permeation Chromatography (GPC) apparatus (GPC-104 type, column: Showa Denko LF-604 combined with KF-602, developing solvent: tetrahydrofuran ) Was used to measure the molecular weight in terms of polystyrene, the weight average molecular weight (Mw) was 9700, the number average molecular weight (Mn) was 5700, and Mw / Mn was 1.70.

<Preparation of curable resin composition A>
6.6 parts of NK-5060 (maximum absorption wavelength 864 nm in methyl ethyl ketone), Hayashibara's cyanine dye, 507 parts of cyclohexanone, 100 parts of the binder resin solution (P), Residtop C-manufactured by Gunei Chemical Industry Co., Ltd. 357 parts of 357 PGMEA (a propylene glycol monomethyl ether acetate solution containing a compound having the following structure as a main component and a solid content concentration of 20% by mass), and 2 bis- (4-tert-butylphenyl) iodonium nonafluorobutanesulfonate from ADEKA .23 parts and 0.14 part of FTX-218D manufactured by Neos Co., Ltd. were mixed to prepare curable composition A.

<Preparation of the second optical layer>
The curable resin composition A is applied on a glass substrate by a spin coating method, heated at 100 ° C. for 120 seconds, and then heated at 140 ° C. for 300 seconds, whereby a thickness of 0.50 μm is formed on the glass substrate. A second optical layer was produced. The film thickness was measured with a stylus type step meter (manufactured by Yamato Scientific Co., Ltd., Alpha Step IQ).

<Spectral transmittance>
The transmittance in each wavelength region of the second optical layer produced on the glass substrate was measured by comparison with a glass substrate using a spectrophotometer (manufactured by JASCO Corporation, V-7300). The spectrum obtained by the measurement is shown in FIG.

  In this example, when measured from the vertical direction of the near-infrared light in the wavelength band (X), measured from the average transmittance of the first optical layer and the vertical direction of the near-infrared light in the wavelength band (X). The product with the average transmittance of the second optical layer is 20%, and the average transmittance of the first optical layer is measured from the direction of oblique 30 degrees of the near infrared light in the wavelength band (X). And the average transmittance of the second optical layer in the wavelength band (X) measured from an oblique 30 degree direction of the near infrared light is 14%, from the vertical direction of the transmitted light at a wavelength of 430 to 620 nm. The product of the average transmittance of the first optical layer when measured and the average transmittance of the second optical layer when measured from the vertical direction of the transmitted light at the wavelength of 430 to 620 nm is 79%, and the wavelength is 4 The average transmittance of the first optical layer when measured from the vertical direction of transmitted light at 0 to 470 nm and the average transmittance of the second optical layer when measured from the vertical direction of transmitted light at the wavelengths of 430 to 470 nm Of the first optical layer when measured from the vertical direction of transmitted light at a wavelength of 520 to 560 nm and the second when measured from the vertical direction of transmitted light at the wavelength of 520 to 560 nm. When the product of the average transmittance of the optical layer is 83% and measured from the vertical direction of the transmitted light at a wavelength of 580 to 620 nm, the average transmittance of the first optical layer and the transmitted light at the wavelength of 580 to 620 nm from the vertical direction When measured, the product of the average transmittance of the second optical layer was 76%.

<Production of near-infrared light pass filter>
<Synthesis example of alkali-soluble polymer>
In a reaction vessel, 14 g of benzyl methacrylate, 12 g of N-phenylmaleimide, 15 g of 2-hydroxyethyl methacrylate, 10 g of styrene and 20 g of methacrylic acid are dissolved in 200 g of propylene glycol monomethyl ether acetate, and further 3 g of 2,2′-azoisobutyronitrile. And 5 g of α-methylstyrene dimer was added. After purging the inside of the reaction vessel with nitrogen, it was heated at 80 ° C. for 5 hours with stirring and nitrogen bubbling to obtain a solution containing the alkali-soluble polymer (E-1) (solid content concentration 35% by mass). This polymer had a polystyrene-equivalent weight average molecular weight of 9700, a number average molecular weight of 5700, and Mw / Mn of 1.70.

<Preparation of Colorant Dispersion 1>
C. I. Pigment Black 32 (hereinafter referred to as “Component (C1-1)”. In Formula (1), R ¹ and R ² are methoxy groups, R ³ and R ⁴ are phenylene groups, and R ⁵ and R ⁶ are methylene groups. 60 parts, C.I. I. Pigment Blue 15: 6 (hereinafter referred to as “component (C2-1)”), 20 parts; I. 20 parts of Pigment Yellow 139 (hereinafter referred to as “component (C3-1)”), 80 parts of Solsperse 76500 manufactured by Nippon Lubrizol Co., Ltd. (solid content concentration 50 mass%), the component (E-1) 120 parts (solid content concentration: 35% by mass) and 700 parts of propylene glycol monomethyl ether acetate were mixed and dispersed for 8 hours using a paint shaker to obtain Colorant Dispersion Liquid 1.

<Production of photosensitive composition 1>
1000 parts of the colorant dispersion 1, 50 parts of dipentaerythritol hexaacrylate, 10 parts of 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], propylene 179 parts of glycol monomethyl ether acetate and 17 parts of a solution containing the component (E-1) (solid content concentration 35% by mass) were mixed to prepare photosensitive composition 1.

<Evaluation of near-infrared light pass filter>
The photosensitive composition 1 was applied on a glass substrate by spin coating, and then heated at 100 ° C. for 180 seconds to form a coating film. Thereafter, the entire surface of the coating film on the substrate was exposed (an exposure amount of 1000 mJ / cm ² at a wavelength of 365 nm). Next, the coating film was brought into contact with an aqueous solution containing 0.05% by mass of tetramethylammonium hydroxide for 15 seconds, and then the coating film was washed with water. Next, the glass substrate having the coating film was heated on a hot plate at 200 ° C. for 300 seconds to obtain a glass wafer having a near infrared light pass filter having a thickness of 1.23 μm.

  Using a glass wafer having a near-infrared light pass filter and a spectrophotometer (V-7300, manufactured by JASCO Corporation), the transmittance (% T) of the near-infrared light pass filter at a wavelength of 300 to 1200 nm. FIG. 15 shows the results obtained by measuring the transmittance and the light shielding properties of the near-infrared light pass filter obtained from the photosensitive composition 1. However, the transparency shown in FIG. 15 is a value relative to the glass substrate. The film thickness was measured with a stylus type step meter (manufactured by Yamato Scientific Co., Ltd., Alpha Step IQ).

  As shown in FIG. 15, it was found that the near-infrared light pass filter manufactured according to the above procedure effectively shields light with a wavelength of 800 nm or less and efficiently transmits near-infrared light.

  In this example, when measured from the vertical direction of the near-infrared light in the wavelength band (X), measured from the average transmittance of the first optical layer and the vertical direction of the near-infrared light in the wavelength band (X). The product of the average transmittance of the near-infrared light pass filter in this case is 65%, and the average of the first optical layer when measured from the direction of oblique 30 degrees of the near-infrared light in the wavelength band (X) The product of the transmittance and the average transmittance of the near-infrared light pass filter when measured from the direction of oblique 30 degrees of the near-infrared light in the wavelength band (X) is 40%, and the transmitted light at a wavelength of 430 to 620 nm. The average transmittance of the first optical layer when measured from the vertical direction of the filter and the flatness of the near-infrared light path filter when measured from the vertical direction of transmitted light at the wavelengths of 430 to 620 nm. The product of the transmittance was 2%.

1: Light 2: Spectrophotometer 3: Optical filter 10: Imaging device (camera)
11: Light source 12: Solid-state imaging device (image sensor)
13: Signal processing unit 14: Main control unit 15: Imaging target 16: Package 17: Pixel unit 18: Terminal unit 19: Enlargement unit 20: Pixel 21: First optical layer (dual band pass filter)
22: First gap 23: Micro lens array 24: Second gap 25: Second optical layer (near infrared light cut filter)
26: third gaps 27a to 27c: visible light pass filter 27d: near infrared light pass filter 28: insulators 29a to 29d: photodiode 30: support substrate

Claims (18)

A first optical layer that transmits at least part of visible light and near infrared light;
A near-infrared light pass filter that absorbs at least part of visible light and transmits at least part of near-infrared light; and
A first light receiving element for detecting the visible light transmitted through the first optical layer, and a second light receiving element for detecting the near infrared light transmitted through the first optical layer and the near infrared light pass filter. A pixel array comprising:
A solid-state imaging device comprising:
The near-infrared light path filter is provided in a portion corresponding to the second light receiving element,
From the shortest wavelength (X1) at which the transmittance of the near infrared light in the first optical layer is 30% or more when measured from the vertical direction, the longest wavelength (X2) at which the transmittance is 30% or less. When the wavelength band up to is X,
When measured from the vertical direction of the near-infrared light in the wavelength band (X) and the average transmittance of the first optical layer when measured from the vertical direction of the near-infrared light in the wavelength band (X) A solid-state imaging device, wherein a product of the near-infrared light pass filter and the average transmittance is 30% or more.   The product of the average transmittance of the first optical layer when measured from the vertical direction at wavelengths of 430 nm to 620 nm and the average transmittance of the near-infrared light path filter when measured from the vertical direction at wavelengths of 430 nm to 620 nm is The solid-state imaging device according to claim 1, wherein the solid-state imaging device is 30% or less.   The solid-state imaging device according to claim 1, wherein a wavelength of the near infrared light is 750 to 2500 nm.   4. The solid-state imaging device according to claim 1, wherein the first optical layer includes a compound (A) that absorbs part of near infrared light. 5.   The solid-state imaging device according to claim 4, wherein the compound (A) has an absorption maximum at a wavelength of 600 to 850 nm.   The compound (A) is at least one compound selected from the group consisting of squarylium compounds, phthalocyanine compounds, naphthalocyanine compounds, croconium compounds, hexaphyrin compounds, and cyanine compounds. The solid-state imaging device according to claim 4.   7. The solid-state imaging device according to claim 1, wherein an average transmittance of the first optical layer when measured from a vertical direction at a wavelength of 430 nm to 620 nm is 60% or more.   8. The apparatus according to claim 1, further comprising a second optical layer that has an opening at a portion corresponding to the second light receiving element and absorbs at least a part of near infrared light. The solid-state imaging device described.   The solid-state imaging device according to claim 8, wherein the second optical layer absorbs at least a part of the near-infrared light transmitted through the first optical layer.   The solid-state imaging device according to claim 8 or 9, wherein the second optical layer includes a curable resin composition including a compound (B) having absorption in the wavelength band (X).   The solid-state imaging device according to claim 10, wherein the compound (B) has an absorption maximum at a wavelength of 750 to 2000 nm.   The compound (B) is a diiminium compound, squarylium compound, cyanine compound, phthalocyanine compound, naphthalocyanine compound, quaterylene compound, aminium compound, iminium compound, azo compound, anthraquinone compound, porphyrin compound It is at least one compound selected from the group consisting of a compound, a pyrrolopyrrole compound, an oxonol compound, a croconium compound, a hexaphyrin compound, a metal dithiol compound, a copper compound, a tungsten compound, and a metal boride. The solid-state imaging device according to claim 10. The solid-state imaging device according to claim 1, wherein the near-infrared light path filter satisfies the following conditions (I) and (II).
Condition (I): The average transmittance of light at a wavelength of 450 to 600 nm is 15% or less.
Condition (II): The average transmittance of light at a wavelength of 900 to 1000 nm is 80% or more. The near-infrared light pass filter includes at least a colorant represented by (C1) to (C3) or at least a colorant represented by (C4) to (C6). The solid-state imaging device according to any one of the above.
(C1) Colorant represented by the following formula (1) (however, 40 to 80% by mass in all colorants)
(C2) One or more colorants selected from blue colorants and green colorants (however, 10 to 40% by mass in all colorants)
(C3) One or more colorants selected from yellow colorants and red colorants (however, 10 to 40% by mass in all colorants)
(C4) One or more colorants selected from a compound having a structure represented by the following formula (2) and a compound having a structure represented by the following formula (3) (C5) One kind selected from a purple colorant and a red colorant Colorant above (C6) Yellow colorant

(In formula (1), R ¹ and R ² each independently represent a hydrogen atom, a hydroxyl group, a methoxy group or an acetyl group. R ³ and R ⁴ each independently represent a phenylene group or a direct bond. R ⁵ and R ⁶ each independently represents a direct bond or an alkanediyl group having 1 to 10 carbon atoms, provided that R ³ and R ⁵ are not simultaneously a direct bond, and R ⁴ and R ⁶ Are not simultaneously direct bonds.)

(In formula (2), M represents a metal atom.)   The solid-state imaging device according to claim 14, wherein the near-infrared light pass filter includes a curable resin composition including the compounds (C1) to (C3) or the compounds (C4) to (C6). .   The average transmittance of the first optical layer when measured from the direction of oblique 30 degrees of the near infrared light in the wavelength band (X) and the oblique angle of 30 degrees of the near infrared light in the wavelength band (X) The solid-state imaging device according to any one of claims 1 to 15, wherein a product of the near-infrared light pass filter and the average transmittance when measured from the direction is 25% or more.   17. The solid-state imaging device according to claim 1, wherein a center wavelength of the wavelength band (X) is in a range of 780 to 950 nm. A first optical layer that transmits at least part of visible light and near infrared light;
A near-infrared light path filter that absorbs at least part of visible light and transmits at least part of near-infrared light; and an optical filter comprising:
From the shortest wavelength (X1) at which the transmittance of the near infrared light in the first optical layer is 30% or more when measured from the vertical direction, the longest wavelength (X2) at which the transmittance is 30% or less. When the wavelength band up to is X,
When measured from the vertical direction of the near-infrared light in the wavelength band (X) and the average transmittance of the first optical layer when measured from the vertical direction of the near-infrared light in the wavelength band (X) The optical filter, wherein the product of the near-infrared light pass filter and the average transmittance is 30% or more.

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