KR20110102192A - Photoelectric transformation element amd manufacturing method thereof, and composition for forming optical waveguide and cured body thereof - Google Patents

Abstract

(Problem) Provided is a photoelectric conversion element having an optical waveguide having good solvent resistance and good heat resistance.
(Solution means) The photoelectric conversion element 100 according to the present invention includes a substrate 10, a photoelectric conversion unit 20 formed above the substrate 10, and an optical waveguide formed above the photoelectric conversion unit 20. The part 30 is provided, and the optical waveguide part 30 contains the cured product of the composition containing sulfur and the polyimide whose refractive index at 633 nm is 1.60 or more, and a crosslinking agent.

Description

Photoelectric conversion element, its manufacturing method, and the composition for optical waveguide formation, and its hardened | cured material TECHNICAL FIELD OF THE INVENTION

This invention relates to a photoelectric conversion element, its manufacturing method, the optical waveguide formation composition, and its hardened | cured material.

BACKGROUND ART Photoelectric conversion elements such as solid-state imaging devices mounted in digital cameras, cellular phones, and the like are used in a plurality of two-dimensional optical reception units (photoelectric conversion mechanisms) such as CCD (Charge Coupled Device) and MOS (Metal Oxide Semiconductor). It has a structure arranged. Such photoelectric conversion elements have been required to increase the number of pixels conventionally. That is, miniaturization of each pixel is progressing in the photoelectric conversion element gradually. In connection with this, the light reception amount per unit pixel of a photoelectric conversion element becomes very small.

If the amount of light received by the light receiving portion is insufficient, the quality of the image to be imaged is degraded. Therefore, a method of increasing the amount of received light per pixel has been proposed. For example, providing a lens for focusing light on a light receiving portion of a photoelectric conversion element, providing an optical waveguide to the element, and the like have been proposed. As an example of forming an optical waveguide, for example, Patent Document 1 describes that the optical waveguide is formed of a material having a high refractive index. In this document, as such a high refractive index material, it is disclosed to use a composite material of a resin having high transparency and metal oxide particles having a high refractive index such as titanium oxide.

Moreover, Patent Literature 2 discloses an attempt to increase the refractive index of an optical member by using a specific polyamic acid and the imidized polymer thereof.

Japanese Laid-Open Patent Publication No. 2008-091744 Japanese Laid-Open Patent Publication No. 2008-274234

However, since the pixel of the photoelectric conversion element is very small, the dimension of the optical waveguide is also very small. That is, the optical waveguide has a small light receiving surface area and a long waveguide path (a large aspect ratio).

Therefore, when using the resin composition containing the above-mentioned metal oxide particle as a material of an optical waveguide, in the process of forming an optical waveguide at the time of manufacture, a material is uniformly distributed over the whole opening for an optical waveguide. It is getting hard to charge.

For example, when the refractive index of resin itself which forms an optical waveguide can be improved by resin etc. which were disclosed in the said patent document 2, embedding property is considered to be favorable. However, since the polyimide resin disclosed in this document is a relatively low molecular weight body, there is a concern that solvent resistance and heat resistance become insufficient. Therefore, in the case of forming a color filter, an anti-reflection film, a planarization film, or the like on the upper part of the waveguide part, the mixture is whitened with these, or coloring by heating occurs in the solder reflow process, thereby deteriorating the light collecting property. There was a concern.

This invention is made | formed in view of the said subject, One of the objectives in accordance with the some aspect is providing the photoelectric conversion element which has an optical waveguide with good solvent resistance and heat resistance. Moreover, one of the objectives in accordance with some aspects of this invention is providing the manufacturing method of the photoelectric conversion element which has an optical waveguide with favorable solvent resistance and heat resistance. Moreover, one of the objectives in accordance with some aspects of this invention is providing the composition suitable for the optical waveguide of a photoelectric conversion element, and its hardened | cured material.

This invention is made | formed in order to solve at least one part of the above-mentioned subject, and can be implement | achieved as the following aspects or application examples.

[Application Example 1] An aspect of a photoelectric conversion element according to the present invention includes a substrate, a photoelectric conversion portion formed above the substrate, and an optical waveguide portion formed above the photoelectric conversion portion. Part contains the hardened | cured material of the composition containing sulfur and the polyimide whose refractive index in 633 nm is 1.60 or more, and a crosslinking agent.

In addition, in this specification, the term "upper" is used, for example, "it forms another specific thing (henceforth" B ") in" upper "of a specific thing (henceforth" A "). It is used for such. In this specification, in this case, unless otherwise indicated, the case of forming B directly on A, the case of forming B through another on A, and the formation of B on the top of A It shall be included.

Application Example 2 In Application Example 1, the cured product may include a structure represented by the following General Formula (1).

(In General Formula (1), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4).

[Application Example 3] In Application Example 2, R may be a tetravalent aliphatic or alicyclic hydrocarbon having 4 to 12 carbon atoms.

[Application Example 4] In at least one of Application Examples 1 to 3, the crosslinking agent is at least selected from alkyl etherates of methylol melamine, alkyl ether compounds of methylol melamine condensates, and polyfunctional vinyl ether compounds. One kind may be sufficient.

[Application Example 5] In any of Application Examples 1 to 4, the optical waveguide part has a columnar shape, and one end in the longitudinal direction of the columnar shape is optically connected to the photoelectric conversion part. good.

Application Example 6 In Application Example 5, in the cross section parallel to the longitudinal direction of the optical waveguide portion, the length in the longitudinal direction is the maximum length in the length in the direction perpendicular to the longitudinal direction. 0.5 times or more and 10 times or less may be sufficient.

[Application Example 7] One aspect of the method for manufacturing a photoelectric conversion element according to the present invention includes a step of forming a photoelectric conversion part above the substrate, a step of forming an interlayer insulating layer to cover the photoelectric conversion part, and the interlayer. Forming a hole penetrating the upper surface of the photoelectric conversion unit in the insulating layer, filling the hole with a composition containing a structure represented by the following general formula (1), and a composition containing a crosslinking agent, and Curing the composition.

(In general formula (1), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, and represents a bivalent sulfur atom, and a respectively represents the number of 0-4 independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4).

Application Example 8 In Application Example 7, R may be a tetravalent aliphatic or alicyclic hydrocarbon having 4 to 12 carbon atoms.

[Application Example 9] In Application Example 7 or Application Example 8, the composition includes a structure represented by General Formula (1) when the total amount of components excluding the organic solvent of the composition is 100% by mass. 80 mass% or more and 99 mass% or less of a polymer may contain 1 mass% or more and 20 mass% or less of a crosslinking agent.

[Application Example 10] One embodiment of the optical waveguide forming composition according to the present invention includes a polymer having a structure represented by the following General Formula (1), a crosslinking agent, and an organic solvent capable of dissolving these uniformly, and an organic solvent. When the component whole quantity except this is 100 mass%, the polymer containing the structure represented by the said General formula (1) contains 80 mass% or more and 99 mass% or less, and the crosslinking agent contains 1 mass% or more and 20 mass% or less.

(In general formula (1), R <^1> respectively independently represents a C1-C3 alkyl group, a cyno group, or a bivalent R <^1> couple | bonded, represents a divalent sulfur atom, and a respectively represents the integer of 0-4 independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4).

APPLICATION EXAMPLE 11 The polymer which has a structure represented by following General formula (2) may be sufficient as the polymer containing the structure represented by the said General formula (1) in Application Example 10.

(In General Formula (2), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, and represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4, l and m represent an integer of 1 to 100,000 in total, and l: m is 50:50 to 100: 0.

Application Example 12 In Application Example 10 or Application Example 11, R may be a tetravalent aliphatic or alicyclic hydrocarbon having 4 to 12 carbon atoms.

Application Example 13 One aspect of the cured product according to the present invention is obtained by curing a polymer containing a structure represented by the following General Formula (1) and a composition containing a crosslinking agent.

(In General Formula (1), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4).

The photoelectric conversion element which concerns on this invention contains the hardened | cured material which has a structure as described in an optical waveguide part containing tetracarboxylic dianhydride, an aromatic diamine containing a sulfur atom, and a crosslinking agent. Therefore, it has an optical waveguide with good solvent resistance and heat resistance, the flatness and the filling property of an optical waveguide part are favorable, and manufacture is easy. Moreover, since the optical waveguide part contains a sulfur atom and an aromatic ring, the optical waveguide part has a large refractive index. Thereby, the photoelectric conversion element which concerns on this invention has favorable condensing efficiency. According to the manufacturing method of the photoelectric conversion element which concerns on this invention, the optical waveguide part has the process of filling the polymer containing the structure represented by General formula (1), and the composition containing a crosslinking agent. Therefore, the photoelectric conversion element which has an optical waveguide with favorable solvent resistance and heat resistance can be manufactured easily.

FIG. 1: is a schematic diagram of the cross section of the main part of the photoelectric conversion element 100 which concerns on the example of embodiment.
2 is an enlarged schematic view of a main portion of a photoelectric conversion element 100 according to an example of the embodiment.
3 is a schematic diagram of a step of forming an interlayer insulating layer during the manufacturing process of the photoelectric conversion element 100 according to the example of the embodiment.
4 is a schematic diagram of a step of forming a hole in an interlayer insulating layer during the manufacturing process of the photoelectric conversion element 100 according to the example of the embodiment.
5 is a schematic view of a step of filling a composition in a process of manufacturing the photoelectric conversion element 100 according to the example of the embodiment.
6 is a schematic view of a step of removing the optical waveguide part formed on the interlayer insulating layer during the manufacturing process of the photoelectric conversion element 100 according to the example of the embodiment.

(Form to carry out invention)

EMBODIMENT OF THE INVENTION Below, preferred embodiment of this invention is described. Embodiment described below demonstrates an example of this invention. In addition, this invention is not limited to the following embodiment, but also includes various modified examples implemented in the range which does not change the summary of this invention. In addition, not all the structures demonstrated in the following embodiment are essential components of this invention.

As an example of the photoelectric conversion element which concerns on this invention, a charge coupling element (CCD) and an MOS type imaging element are mentioned. In the following embodiment, the photoelectric conversion element 100 containing a CCD is illustrated.

1. Photoelectric conversion element

FIG. 1: is a schematic diagram of the cross section of the main part of the photoelectric conversion element 100 which concerns on the example of embodiment. 2 is an enlarged schematic view of a cross section of a main portion of the photoelectric conversion element 100.

The photoelectric conversion element 100 of the present embodiment includes a substrate 10, a photoelectric conversion unit 20, and an optical waveguide part 30.

1. 1. Substrate

The substrate 10 becomes a base of the photoelectric conversion element 100. The substrate 10 has a shape such as a flat plate shape, a film shape, a sheet shape, or the like. The substrate 10 may be a laminate of a plurality of substrates. The board | substrate 10 may be comprised including a semiconductor substrate and a wiring board, for example. On the substrate 10, a photoelectric conversion unit 20 (to be described later), a resistor, and the like may be formed. The substrate 10 may have a transistor (for example, a TFT), an IC for control, a wiring layer, or the like. 1 shows an example in which the photoelectric conversion unit 20 is formed on the substrate 10.

It does not specifically limit as a material of the board | substrate 10, Inorganic materials, such as a metal, glass, silicon, and gallium arsenide, (meth) acrylic resin, a polyimide resin, an alicyclic olefin resin, a polycarbonate, a polyethylene terephthalate Polymeric materials, such as these, can be illustrated. In addition, the board | substrate 10 may be what laminated | stacked multiple layers. For example, the board | substrate 10 may contain the reflecting layer etc. which reflect light. When the substrate 10 is a semiconductor substrate such as a silicon substrate or a GaAs substrate, it is easy to form the photoelectric conversion section 20 in the substrate 10.

1. Photoelectric conversion unit

The photoelectric conversion unit 20 is formed above the substrate 10. The photoelectric conversion unit 20 may be formed to be embedded in the upper surface of the substrate 10. In the photoelectric conversion element 100 of the present embodiment, the photoelectric conversion unit 20 is formed on the upper surface side of the substrate 10.

The shape of the photoelectric conversion part 20 is not specifically limited, In planar view, it can be set as elliptical, circular, rectangular, square, etc. Although the area of the photoelectric conversion part 20 in plan view can be suitably designed according to design, such as the resolution of the photoelectric conversion element 100, For example, the length of one side in the case of square shape is 100 nm. It can be 10 micrometers or less as mentioned above. The photoelectric converter 20 may be formed in plural on the substrate 10. The number of photoelectric conversion units 20 formed in the substrate 10 is appropriately selected depending on the design of the resolution of the photoelectric conversion element 100 and the like, and is not particularly limited. In addition, the thickness of the photoelectric conversion unit 20 is not particularly limited.

The photoelectric conversion part 20 is a part (light sensor) which converts light into an electric signal, or a part which converts electricity into light, and can apply a well-known photoelectric conversion element, for example, a photodiode. For example, the photoelectric conversion part 20 can be comprised by the pn junction etc. which made the board | substrate 10 a semiconductor substrate, and the different area | region of a conductive type was formed in the surface. In addition, the photoelectric conversion unit 20 may be formed including other structures such as a resistor.

Although the wavelength range of the electromagnetic wave (light) detected by the photoelectric conversion part 20 is not specifically limited, For example, it is the range of 300 nm or more and 1100 nm or less. The photoelectric conversion unit 20 can typically detect visible light and convert it into an electrical signal.

1.3. Optical waveguide part

1. 3. 1. Shape of optical waveguide

The optical waveguide part 30 is formed above the photoelectric conversion part 20. The optical waveguide part 30 is formed by optically connecting to the photoelectric conversion part 20. In addition, as long as the optical waveguide part 30 is optically connected to the photoelectric conversion part 20, you may connect it with the photoelectric conversion part 20 via another member (for example, optical members, such as a lens). . In addition, "optically connecting" means the state which can transmit light.

One of the functions of the optical waveguide part 30 includes condensing light incident on the photoelectric conversion element 100 with respect to the photoelectric conversion part 20 when the photoelectric conversion element is a light receiving element. On the other hand, when a photoelectric conversion element is a light emitting element, the extraction efficiency of the light radiate | emitted from the photoelectric conversion element 100 with respect to the light emitted from the photoelectric conversion part 20 is mentioned. Therefore, it is preferable that the optical waveguide part 30 is formed from the material whose refractive index is larger than the other member which adjoins. It is preferable that it is 1.60 or more, and, as for the refractive index of an optical waveguide part, it is more preferable that it is 1.65 or more. In addition, in this invention, a "refractive index" means the refractive index in 633 nm at 25 degreeC. As a result, light can be confined to the optical waveguide part 30, and the light condensing efficiency to the photoelectric converter 20 can be further increased. The detail of the material of the optical waveguide part 30 is mentioned later.

The optical waveguide part 30 is provided corresponding to each photoelectric conversion part 20. The optical waveguide part 30 has a columnar shape. And the optical waveguide part 30 is arrange | positioned so that one end of the columnar longitudinal direction may be optically connected to the photoelectric conversion part 20. As shown in FIG. Although it does not specifically limit as a specific shape of the optical waveguide part 30, For example, it can be set as cylindrical shape, a prismatic shape, a truncated cone, a pyramid, etc.

In the photoelectric conversion element 100 of the present embodiment, since the shape of the optical waveguide part 30 is columnar, the optical waveguide part 30 can be arranged at a high density (the resolution of the photoelectric conversion element 100 is increased. And insulation in the thickness direction (the longitudinal direction of the optical waveguide part 30) can be ensured. In addition, since the optical waveguide part 30 has a columnar shape, it is easy to condense light incident from the outside of the photoelectric conversion element 100 with respect to the photoelectric conversion part 20.

In the example of FIG. 1, the optical waveguide part 30 has the shape of the truncated cone which becomes smaller in the cross section side on the photoelectric conversion part 20 side. In addition, the upper or lower surface of the optical waveguide part 30 may have a convex shape or a concave shape. In this way, the optical waveguide part 30 can be given the function of an optical lens. The uneven shape in this case can be freely designed in consideration of the optical path of the incident light.

In the cross section parallel to the longitudinal direction, the optical waveguide part 30 is more preferably 0.5 to 10 times the maximum length in the length in the direction perpendicular to the longitudinal direction. By setting the optical waveguide part 30 in such a shape, the resolution of the photoelectric conversion element 100 can be further increased, and the insulation in the longitudinal direction of the optical waveguide part 30 can be ensured.

Although the optical waveguide part 30 may be arrange | positioned independently as long as it is arrange | positioned above the photoelectric conversion part 20, like the photoelectric conversion element 100 of this embodiment, it is upper side of the board | substrate 10, for example. A hole 42 may be formed in the interlayer insulating layer 40 formed therein, and an optical waveguide portion 30 may be formed inside the hole 42 (see FIG. 2). By doing in this way, manufacture of the optical waveguide part 30 can be made easier, for example.

It is preferable that the refractive index of the optical waveguide part 30 is higher than the refractive index of the surrounding. When the interlayer insulating layer 40 is formed, SiO _{2 having a} refractive index of 1.4 to 1.5 and a refractive index of 1.4 to 1.5 are used as the material of the interlayer insulating layer 40 in order to improve the light collecting efficiency to the photoelectric conversion unit 20. It is preferable to be formed from SiO ₂ materials such as BPSG (borophosphosilicate glass), PSG (phosphosilicate glass), SOG (spin-on glass), or SiON (silicon oxynitride) materials that are about 1.5. When the interlayer insulating layer 40 is formed of silicon oxide (SiO ₂ ), for example, the interlayer insulating layer 40 may be formed by a thermal oxidation method, a chemical vapor deposition (CVD) method, or the like.

In addition, the photoelectric conversion element 100 of this embodiment may have the on-chip lens 50 for condensing to the optical waveguide part 30, as shown in FIG. Although the on-chip lens 50 is provided above the optical waveguide part 30 in the example of illustration, it may be provided below. In addition, the on-chip lens 50 may be provided in plurality.

1. 3. 2. Material of optical waveguide

1. 3. 2. 1. Composition

The optical waveguide portion 30 is formed of a cured product of a composition containing sulfur and having a refractive index of 1.60 or more at 633 nm and a crosslinking agent. The said polyimide can be obtained by condensing an aromatic diamine compound containing tetracarboxylic dianhydride and sulfur, for example, and imidizing it further.

<1> tetracarboxylic dianhydride

The compound represented by following General formula (3) can be used for the tetracarboxylic dianhydride used as a raw material for obtaining the said polyimide.

(In General Formula (3), R represents a tetravalent organic group.).

In General Formula (3), R may have a structure classified into at least one of aliphatic, alicyclic and aromatic. The tetracarboxylic dianhydride is preferably an aliphatic or alicyclic tetracarboxylic dianhydride in which R is aliphatic or alicyclic, and more preferably an aliphatic tetracarboxylic dianhydride from the viewpoint of increasing the transparency of the cured product obtained.

Specific examples of aliphatic and alicyclic tetracarboxylic dianhydrides include 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4 -Cyclopentanetetracarboxylic dianhydride, 4,10-dioxatricyclo [6.3.1.0 ^2,7 ] dodecane-3,5,9,11-tetraone, 1,2,4,5-cyclohexanetetra Carboxylic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5, 9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 5- (2,5-di Oxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2.2.2] -octo-7-ene-2,3,5,6-tetracarboxylic dianhydride Tetracarboxylic dianhydrides, such as water, are mentioned. Among them, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 4,10-dioxatricyclo [6.3.1.0 ^2,7 ] Dodecane-3,5,9,11-tetraone, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride and 1,3, More preferred is 3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 4,10-dioxatricyclo [6.3.1.0 ^2,7 ] dode CAN-3,5,9,11-tetraone and 1,2,4,5-cyclohexanetetracarboxylic dianhydride are more preferable from a viewpoint of improving transparency of hardened | cured material.

Specific examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfontetracarboxylic dianhydride Water, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenylethertetracarboxylic dianhydride , 3,3 ', 4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3', 4,4'-tetraphenylsilanetetracarboxylic dianhydride, 2,3,4,5-tetrahydro Furantetetracarboxylic dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride Water, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 4,4 '-(hexafluoroisopropylidene) bis (phthalic acid) dianhydride, 3,3', 4 , 4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis Phenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenylether dianhydride, bis (triphenylphthalic acid) -4,4'- Aromatic tetracarboxylic dianhydrides, such as diphenylmethane dianhydride, are mentioned. Among these, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfontetracarboxylic dianhydride, 4,4 '-(Hexafluoroisopropylidene) bis (phthalic acid) dianhydride and 3,3', 4,4'-biphenyltetracarboxylic dianhydride are more preferable because the cured product has a high refractive index.

Moreover, it is more preferable that tetracarboxylic dianhydride contains a sulfur atom from a viewpoint of obtaining the hardened | cured material of a higher refractive index. As an example of the tetracarboxylic dianhydride containing a sulfur atom, 4,4 '-[p-thiobis (phenylene sulfanyl)] diphthalic dianhydride etc. are mentioned.

The structure based on tetracarboxylic dianhydride is, for example, polymerized in the state of tetracarboxylic acid (state not being an anhydride of the above-described tetracarboxylic dianhydride) to form a structure based on polyamic acid, and It may be formed by performing a dehydration reaction using an imidization catalyst later.

The polyamic acid formed by superposition | polymerization in the state of tetracarboxylic acid can be chemical imidation or thermal imidation. As an imidation catalyst used at the time of chemical imidation, an acetic anhydride-pyridine mixed solution etc. are mentioned, for example. Moreover, the acetic anhydride-triethylamine mixed solution, trifluoro acetic anhydride, and dicyclohexyl carbodiimide can also be used. As the imidation catalyst, a photoacid generator or a photobase generator, which is a compound that generates an acid or a base by irradiation with light, may be used. As a photobase generator, a carbamate-type photobase generator etc. are mentioned, for example.

<2> aromatic diamines containing sulfur atoms

As aromatic diamine containing the sulfur atom used as a raw material for obtaining the said polyimide, the compound represented by following General formula (4) is mentioned.

(In General Formula (4), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , n represents an integer of 1 to 4).

In General Formula (4), it is more preferable that a is 0 (that is, no substituent) or R ¹ is a cyano group and a is 1 from the viewpoint of the refractive index. In addition, it is more preferable that n is an integer of 2-4 from a refractive index viewpoint.

As an example of the diamine represented by General formula (4), it is 4,4 '-(p-phenylene disulfanyl) dianiline, 1, 3-bis (4-aminophenylsulfanyl) benzene, 1, 3-, for example. Bis (4-aminophenolsulfanyl) -5-cyanobenzene, 4,4'-thiobis [(p-phenylenesulfanyl) aniline], 4,4'-bis (4-aminophenylsulfanyl) -p -Dithiophenoxybenzene, etc. are mentioned, Among these, 4,4'- thiobis [(p-phenylenesulfanyl) aniline] is more preferable from a refractive index viewpoint.

<3> other monomer components

The polyimide used by this embodiment may contain the structure derived from another monomer. For example, the polyimide may contain a structure based on diamines other than aromatic diamines containing sulfur atoms. As such diamine, p-phenylenediamine, m-phenylenediamine, 4,4'- diamino diphenylmethane, 4,4'- diaminodiphenylethane, 4,4'- diaminodi, for example. Phenylsulfide, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylether, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 3,4'-diaminodiphenylether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone , 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4- Aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-amino Phenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 9,9-bis (4-aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroanyl Lin), 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl , 3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 4,4'-(m-phenylenediisopropylidene) Aromatic diamines having hetero atoms such as bisaniline and diaminotetraphenylthiophene; 1,1-methylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindenylenedimethylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyl Aliphatic or alicyclic diamine, such as diamine, is mentioned.

When introducing the structure based on the said diamine into the said polyimide, when making the whole monomeric unit of the said polyimide into 100 mass%, the structure based on the said diamine becomes like this. Preferably it is 30 mass% or less, More preferably, The compounding quantity can be suitably adjusted in order to set it as 20 mass% or less, and to adjust the refractive index of hardened | cured material.

<4> polyimide

As for the polyimide used for the composition of this embodiment, the polyimide which contains sulfur and whose refractive index in 633 nm is 1.60 or more is used. When polyimide contains sulfur, the refractive index of the polyimide obtained becomes high and as a result, the refractive index of the optical waveguide part 30 can be raised. Moreover, it is preferable that the refractive index of a polyimide is 1.65 or more. In addition, the number average molecular weight which measured the polyimide by the gel permeation chromatography is workability at the time of forming the optical waveguide part 30 (easiness of application in the case of making it into a solution), especially the hole which forms the optical waveguide part 30 It is preferable that they are 2,000 or more and 10,000 or less, and, as for the embedding property to, it is more preferable that they are 3,000 or more and 8,000 or less.

As a polyimide obtained from the tetracarboxylic dianhydride and the aromatic diamine containing a sulfur atom, it can have a repeating unit represented by following General formula (1).

(In General Formula (1), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4).

The polymer of the structure represented by General formula (1) can be obtained, for example by making aromatic diamine containing the above-mentioned sulfur atom react with the above-mentioned tetracarboxylic dianhydride.

Reaction of the aromatic diamine containing a sulfur atom with tetracarboxylic dianhydride can be performed in non-protic organic solvents, such as N-methyl- 2-pyrrolidone, for example. The polymer of General formula (1) can be obtained by stirring and mixing the aromatic diamine compound containing a sulfur atom, and tetracarboxylic dianhydride. For example, you may melt | dissolve the aromatic diamine containing a sulfur atom in the organic solvent, add tetracarboxylic dianhydride to this, and stir and mix. The reaction is performed under normal pressure, for example, at a temperature of 100 ° C. or lower, preferably 80 ° C. or lower. As needed, you may carry out under pressure or reduced pressure. Although reaction time changes with the diamine compound to be used, an acid dianhydride, an organic solvent, reaction temperature, etc., it is the range of 1 to 24 hours, for example. The polymer thus obtained can be imidized by heating. Under the present circumstances, well-known imidation catalysts, such as an acetic anhydride-pyridine mixed solution and an acetic anhydride-triethylamine mixed solution, and trifluoro acetic anhydride and dicyclohexyl carbodiimide, can also be used.

As a polyimide which has a repeating unit represented by General formula (1), the polymer represented by following General formula (2) may be sufficient.

(In General formula (2), R <^1> , a, R, n are the same as Formula (1), and molar ratio (l: m) is 50: 50-100: 0).

Here, molar ratio (l: m) expresses the imidation ratio of the polymer represented by General formula (2), and imide frame | skeleton (polyimide site | part) (1) and amic acid skeleton (polyamic acid (polyamide) Molar ratio with acid) site | part) (m) is shown. That is, the thing whose molar ratio (l: m) is 50: 50-100: 0 has shown that the imidation ratio is 50% or more and 100% or less in the polymer represented by General formula (2). In other words, a molar ratio (l: m) of 50:50 to 100: 0 indicates that the content ratio of the dark acid is 0% or more and 50% or less in the polymer represented by the general formula (2). When the imidation ratio of the polymer represented by General formula (2) is 50% or more and 100% or less, the solvent tolerance of the optical waveguide part 30 can be improved. For the reason mentioned above, it is preferable that the imidation ratio of the polymer represented by General formula (2) is 70% or more and 100% or less. Here, in this embodiment, polyimide means the imidate of polyamic acid, and all the bonds do not need to be imidized.

The reaction temperature in the case of performing imidation can be 70-150 degreeC, for example. The reaction time is preferably in the range of 1 to 24 hours. When thermal imidation is performed, it can carry out by making the substance which has a structure described in polyamic acid react for 1 to 24 hours at 150-250 degreeC in a high boiling point solvent.

In addition, the content rate of the dark acid (amic acid) in the polymer represented by General formula (2) can be calculated | required by NMR (nuclear magnetic resonance method), for example.

The polyimide which has a repeating unit represented by the said General formula (1) and General formula (2) is a polymer obtained from the tetracarboxylic dianhydride and the aromatic diamine containing a sulfur atom, by making it react with the crosslinking agent mentioned above. And the hardened | cured material which forms an optical waveguide part can be obtained.

<5> crosslinking agent

As a crosslinking agent, a polyfunctional compound is mentioned, For example, a polyfunctional melamine compound, a urea compound, a guanamine compound, a phenol compound, an epoxy compound, an isocyanate compound, a polybasic acid, etc. are mentioned. In addition, a crosslinking agent may be a single type of these compounds, or a combination of two or more types.

Among these crosslinking agents, a melamine compound having a methylol group and an alkoxylated methyl group or two or more thereof in the molecule is preferable because the storage stability is relatively excellent and relatively low temperature curing is possible. In addition, among these melamine compounds, hexamethyl ether methylol melamine compound, hexabutyl ether methylated melamine compound, methyl butyl mixed ether methylol melamine compound, methyl ether methylol melamine compound, butyl ether methylol melamine compound The alkyl etherate of methylol melamine and the alkyl etherate of the condensate of methylol melamine are more preferable because both reactivity and storage stability can be compatible.

On the other hand, as a crosslinking agent, the polyfunctional compound which has two or more ethylenically unsaturated groups, such as polyfunctional ether compounds which have two or more ethylenically unsaturated groups, such as a vinyl group, and polyfunctional (meth) acrylate compounds which have two or more ethylenically unsaturated groups, such as a vinyl group, Can also be used. As a polyfunctional compound which has two or more ethylenically unsaturated groups, it is a polyfunctional vinyl ether compound, for example, 1, 4- butanediol divinyl ether, cyclohexane dimethanol divinyl ether, diethylene glycol divinyl ether, diethylene glycol di As alkyldivinyl ethers, such as vinyl ether, and polyfunctional (meth) acrylate, such as trimethylol propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol hexa (meth) acrylate, etc. (Meth) acrylic esters are mentioned.

When the whole composition except the organic solvent is made into 100%, the quantity of the crosslinking agent in this embodiment has preferable 0.1% or more and 30% or less, and its 1% or more and 20% or less are more preferable. If a crosslinking agent exists in this range, solvent tolerance can be provided to the hardened | cured material obtained.

<6> organic solvent

As an organic solvent used for a composition, it selects so that the polymer and crosslinking agent containing the structure represented by General formula (1) can be melt | dissolved uniformly.

As such an organic solvent, an aprotic organic solvent is mentioned, for example. As the aprotic organic solvent, for example, N-methyl-2-pyrrolidone (NMP), N, N-dimethylformamide (DMF), cyclohexanone (CHN), N, N-dimethylacetamide ( DMAc), γ-butyrolactone (GBL), and the like. In addition to these, N, N-diethylacetamide, N, N-dimethoxyacetamide, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, 1,2-dimethoxyethane, 1,2 -Dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, bis [2- (2-methoxyethoxy) ethyl] ether, tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, pyrroline, picoline, dimethyl sulfoxide, dimethyl sulfone, tetramethyl urea, hexamethylphosphoramide, propylene glycol monomethyl ether (PGME), γ-butyro Lactone (GBL), phenol, o-cresol, m-cresol, p-cresol, m-cresolic acid, p-chlorophenol, anisole, benzene, toluene, xylene and the like. These organic solvents may be used alone or as a mixture of two or more thereof.

In the composition for forming the optical waveguide part 30, the amount of the organic solvent to be added is 100 to 9,900 parts by mass, preferably 100 parts by mass of a polymer having a structure represented by the general formula (1) and a crosslinking agent. Preferably it is 150-1,900 mass parts, More preferably, it can use within the range of 200-1,900 mass parts. If the compounding quantity of the organic solvent with respect to a composition is such a range, favorable application can be performed. The organic solvent may be an organic solvent derived from the production of a polymer containing a structure represented by General Formula (1).

1. 3. 2. 2. Other Ingredients

It is preferable to contain 80% or more of said hardened | cured material with respect to the total mass of the optical waveguide part 30, and, as for the optical waveguide part 30 of this embodiment, it is more preferable to contain 90 mass% or more. Therefore, the optical waveguide part 30 of this embodiment may contain substances other than the hardened | cured material mentioned above in 20 mass% or less.

<Surfactant>

The optical waveguide part 30 may contain surfactant. The surfactant may be used to control the wettability or fluidity of the composition used when forming the optical waveguide part 30. After the optical waveguide part 30 is formed, it may be contained in the optical waveguide part 30 together with the cured product.

As such surfactant, a silicon type surfactant, a fluorine type surfactant, etc. are mentioned, A polydimethylsiloxane type surfactant is mentioned.

As an example of a silicon type surfactant, SH28PA, DC57, DC190, Paintad 19, 54 (made by Toray Dow Corning, dimethyl polysiloxane polyoxyalkylene copolymer), SF8428 (Torre, for example) Dow Corning Co., Ltd., dimethylpolysiloxane polyoxyalkylene copolymer (containing side chain OH), Silaplane FM-4411, FM-4421, FM-4425, FM-7711, FM-7721, FM-7725 , FM-0411, FM-0421, FM-0425, FM-DA11, FM-DA21, FM-DA26, FM-0711, FM-0721, FM-0725, TM-0701, TM-0701T (manufactured by Chisso Corp. ), UV3500, UV3510, UV3530 (manufactured by Big Chemi Japan Co., Ltd.), BY16-004 (manufactured by Torre Dow Corning Silicon Co., Ltd.), VPS-1001 (manufactured by Wako Pure Chemical Industries, Ltd.), Tego Rad 2300, 2200N (made by Tego Chemical Co., Ltd.), etc. are mentioned.

Examples of fluorine-based surfactants include Megaface F-114, F410, F411, F450, F493, F494, F443, F444, F445, F446, F470, F471, F472SF, F474, F475, R30, F477, F478, and F479. , F480SF, F482, F483, F484, F486, F487, F553, F172D, F178K, F178RM, ESM-1, MCF350SF, BL20, R08, R61, R90 (manufactured by Dainippon Inking Chemical Co., Ltd.). .

As one of the functions of the surfactant, for example, in the manufacture of the photoelectric conversion element 100, a composition containing a raw material for forming the cured product is applied by spin coating the optical waveguide part 30 to In the case of forming, forming a uniform coating film is mentioned.

Content in the case where surfactant is contained in the optical waveguide part 30 is 0.001-10 mass% with respect to the component whole quantity except the organic solvent in a composition, Preferably it is 0.01-5 mass%, More preferably, it is 0.01- It is in the range of 2 mass%. When the compounding quantity of surfactant exists in the said range, the applicability | paintability of the composition containing the raw material for forming hardened | cured material becomes favorable.

<Others>

The optical waveguide part 30 may contain an inorganic particle. As an inorganic particle, titanium oxide, zirconium oxide, aluminum oxide etc. are mentioned, for example. Among these, the titanium oxide particles may be blended in order to adjust the refractive index of the optical waveguide part 30. In the case where the optical waveguide portion 30 contains inorganic particles, for example, the amount is 0.001 to 10 mass%, preferably 0.01 to 5 mass%, more preferably relative to 100 mass% of the component total amount excluding the organic solvent. Is in the range of 0.01 to 2% by mass.

The optical waveguide part 30 may contain a resin such as polystyrene.

<Hardened product>

The hardened | cured material of this embodiment is obtained by hardening the above-mentioned composition. Hardening is performed by apply | coating the said composition to a board | substrate, and then heating. The heating temperature at this time is room temperature to 300 degreeC, Preferably it is 30-250 degreeC. Moreover, although heating time can be suitably changed in consideration of the size shape of the hardened | cured material to manufacture, it is preferable to heat normally for 1 minute-2 hours, Preferably it is about 3 minutes-1 hour. Under the present circumstances, you may heat at fixed temperature and you may heat at different temperature one by one. By hardening the above-mentioned composition, the hardened | cured material containing the structure represented by following General formula (1) can be obtained.

1.60 or more are preferable and, as for the refractive index of the hardened | cured material of this embodiment, it is more preferable that it is 1.65 or more.

1. 4. Other Configuration

The photoelectric conversion element 100 of the present embodiment may include various other members. For example, the photoelectric conversion element 100 may include an intralayer lens, a transfer electrode, a light shielding film, a color filter, a planarization layer, an antireflection film, or the like.

1. 5. Effect of effect

In the photoelectric conversion element 100 according to the present embodiment, the optical waveguide part 30 contains a tetracarboxylic dianhydride, an aromatic diamine containing a sulfur atom, and a cured product having a structure based on a crosslinking agent. Therefore, the solvent resistance and heat resistance of the optical waveguide part 30 become favorable. Moreover, since the hardened | cured material contained in the optical waveguide part 30 with which the photoelectric conversion element 100 which concerns on this embodiment has a sulfur atom and an aromatic ring is large in refractive index. Thereby, the photoelectric conversion element 100 has good condensing efficiency to the photoelectric conversion part 20.

2. Manufacturing Method of Photoelectric Conversion Element

3-6 is a schematic diagram of the manufacturing process of the photoelectric conversion element 100 which is an example of this embodiment.

The manufacturing method of the photoelectric conversion element which concerns on this invention is a process of forming a photoelectric conversion part above the board | substrate 10, the process of forming an interlayer insulation layer so that the said photoelectric conversion part may be covered, and the photoelectric conversion part of the said interlayer insulation layer The process of forming the hole penetrating to an upper surface, and the process of filling the said hole with the composition containing the structure represented by the following general formula (1) and a crosslinking agent at least are included.

(In General Formula (1), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4).

Hereinafter, although each process is explained in full detail, in the description of the photoelectric conversion element 100 mentioned above, the same code | symbol is attached | subjected about the member mentioned above and detailed description is abbreviate | omitted.

First, as shown in FIG. 3, the board | substrate 10 is prepared and the photoelectric conversion part 20 is formed above (upper surface) the board | substrate 10. FIG. The photoelectric conversion unit 20 can be formed by a known method, and can be formed, for example, by doping the substrate 10 with impurities. In addition, before or after the formation of the photoelectric conversion unit 20, a charge transfer unit or the like can be formed as necessary. In addition, after formation of the photoelectric conversion part 20, you may form a transfer electrode, an antireflection film, and a light shielding film as needed. Further, insulating films other than the interlayer insulating layer 40 may be formed.

Next, as shown in FIG. 3, the interlayer insulation layer 40a is formed so that the photoelectric conversion part 20 may be covered. The interlayer insulating layer 40a may be formed to cover the photoelectric conversion unit 20 and the substrate 10. In the example of illustration, the interlayer insulation layer 40a covers the photoelectric conversion part 20 and the board | substrate 10, and is formed. The interlayer insulating layer 40a may be formed by, for example, a spin coating method, a CVD method, or the like.

Next, as shown in FIG. 4, the hole 42 penetrating from the upper surface of the interlayer insulating layer 40 to the upper surface of the photoelectric conversion unit 20 is formed in the interlayer insulating layer 40. The hole 42 has a shape corresponding to the outer shape of the optical waveguide part 30. The hole 42 is formed above the photoelectric conversion unit 20. In the present embodiment, the hole 42 is formed through the interlayer insulating layer 40 so as to reach the photoelectric conversion unit 20, but extends toward the photoelectric conversion unit 20. It may be a concave portion formed in The hole 42 may be formed by photolithography or the like, using a suitable mask and etchant. In addition, the hole 42 can also be formed by a well-known method, for example, anisotropic dry etching, reactive dry etching, or the like.

As shown in FIG. 5, the hole 42 is filled with a polyimide containing sulfur and having a refractive index of 1.60 or more at 633 nm and a composition containing a crosslinking agent to form the optical waveguide portion 30a. Specifically, this step can use a method such as coating using a liquid injection nozzle such as a dispenser, spray coating such as an inkjet method, coating by rotation such as spin coating, coating by squeeging such as printing, or transfer.

The composition used in this step may contain, for example, an organic solvent in order to control the viscosity of the composition, in addition to polyimide containing sulfur and having a refractive index of 1.60 or more at 633 nm and a crosslinking agent. As an organic solvent used for a composition, it is as above-mentioned.

In order to improve the solvent resistance of hardened | cured material, you may mix | blend an imidation catalyst with a composition. In that case, the compounding quantity of the imidation catalyst with respect to a composition is 20 mass% or less, Preferably it is 10 mass% or less, More preferably, in the range of 5 mass% or less with respect to 100 mass% of component total amounts except the organic solvent. to be. When the imidation catalyst mentioned above is used, the process of hardening treatment can be added as needed. A hardening process can be made into photocuring and thermosetting, for example.

In this process, a particulate matter may be added to the composition to be applied as long as it is a range that does not impair applicability and embedding properties.

In this step, since such a composition is used, a hole (such as a coating by a spray nozzle such as a dispenser, a spray coating such as an inkjet method, a coating by rotation such as spin coating, a coating by squeeging such as printing, or a transfer) is used. It is easy to fill 42 without gaps. In this case, particularly, when the size of the long axis direction of the optical waveguide part 30 is 0.5 to 10 times the size of the short axis direction of the optical waveguide part 30, it is very important to fill the hole 42 without gaps. It can be performed easily.

Then, as needed, as shown in FIG. 6, the process of removing the optical waveguide part 30a (part of parts other than the hole 42) formed on the interlayer insulation layer 40 can be performed. This step can be performed by dry etching, wet etching, or the like. In the case of performing this step, when no particulate matter is added to the coating film of the optical waveguide portion 30a, etching rates such as dry etching and wet etching can be sufficiently increased.

Subsequently, the photoelectric conversion element 100 of this embodiment shown in FIG. 1 can be obtained by providing the microlens array separately prepared above the interlayer insulation layer 40, for example.

According to the manufacturing method of the photoelectric conversion element of this embodiment, the photoelectric conversion element which has an optical waveguide with good light condensation to a photoelectric conversion part, flatness and filling property of an optical waveguide part, and good solvent resistance and heat resistance heat coloring property is easily manufactured. can do.

3. Examples and Comparative Examples

Although an Example and a comparative example are shown to the following and this invention is demonstrated further more concretely, the scope of the present invention is not limited by these.

In the Example and the comparative example, embedding property, heating transparency, and solvent tolerance to the hole of the composition containing the polymer represented by General formula (1), a crosslinking agent, and the organic solvent were evaluated. That is, the following composition was apply | coated to the following base material, and the various shapes of the member after drying, the transparency after heat processing (after hardening), the crack after acetone immersion, the film reduction, or the presence or absence of whitening were evaluated.

The Example and the comparative example modeled the formation process of the optical waveguide in manufacture of a photoelectric conversion element. By this evaluation, the optical characteristic, solvent resistance, ease of manufacture, etc. of an optical waveguide part can be evaluated.

3. 1. Description

As the substrate 10, a silicon substrate was used. On the upper surface of the silicon substrate, a SiO ₂ film having a thickness of 3 µm was formed by spin coating and baked. The SiO ₂ film was etched to form holes (through holes reaching the silicon substrate) with an opening diameter of 0.8 μm and a depth of 3 μm. The refractive index of the SiO ₂ film is around 1.45, and when the refractive index of the optical waveguide portion formed in the embodiment is high, the light condensing property in the photoelectric conversion element is realized.

3. 2. Composition

As a composition which forms hardened | cured material, the composition of A-L shown in Table 1 was prepared.

Although the unit of a number is a mass part in a table | surface, it can be seen by mass% about the compounding quantity of the component except a solvent.

In Table 1, P-1 is an acid dianhydride, 3SDA (4,4 ') as BT-100 (1,2,3,4- butanetetracarboxylic dianhydride by Shin-Nihon Rica Co., Ltd.) and diamine. -A polymer synthesized using -thiobis [(p-phenylenesulfanyl) aniline]). In addition, 3SDA was synthesize | combined by the method of Unexamined-Japanese-Patent No. 2008-274234.

In preparation of P-1, first, dimethylacetamide (30 g) (hereinafter referred to as DMAc) was added to 3SDA (11.9 g, 27.5 mmol) in a reaction vessel equipped with a nitrogen inlet tube, and stirred at room temperature to completely dissolve it. . Next, BT-100 (5.45 g, 27.5 mmol) and DMAc (10 g) were added, and it stirred at 40 degreeC for 4 hours. Subsequently, after adding DMAc (110g), acetic anhydride (2.81g) and pyridine (2.18g) were added as an imidation catalyst, and it stirred at 110 degreeC for 5 hours, and obtained DM-1 solution of P-1. A predetermined amount of DMAc was removed by vacuum distillation to obtain a solution having a solid content concentration of 20%, and then a predetermined amount of γ-butyrolactone (hereinafter referred to as GBL) was added to a solution having a solid content concentration of 10%. After repeating this operation twice, it adjusted to solid content concentration 45% by the vacuum distillation again, and obtained the GBL solution of P-1. The imidation ratio of P-1 was 50%. That is, P-1 is 50:50 of l: m in the polymer which has a structure represented by General formula (2).

In Table 1, P-2 represents the polymer synthesize | combined similarly to P-1 by increasing the acetic anhydride and pyridine which are imidation catalysts, than P-1. A GBL solution of P-2 was prepared in the same manner as P-1 except that acetic anhydride (5.61 g) and pyridine (4.35 g) were used. The imidation ratio of P-2 was 90%. That is, l: m is 90:10 in P-2 which has a structure represented by General formula (2).

In Table 1, P-3 represents the polymer which synthesize | combined the acetic anhydride and pyridine which are imidation catalysts further, and synthesize | combined more than P-2. A GBL solution of P-3 was prepared in the same manner as P-1 except that acetic anhydride (8.43 g) and pyridine (6.54 g) were used. The imidation ratio of P-3 was 93%. That is, in the polymer which has a structure represented by General formula (2) in P-3, l: m is 93: 7.

In addition, the imidation ratio of P-1 to P-3 calculated | required and calculated the content rate of dark acid. Specifically, NMR (nuclear magnetic resonance method) of P-1 to P-3 was measured and calculated | required.

In Table 1, P-4 was prepared as follows. First, N-methyl-2-pyrrolidone (80 g) (NMP) was added to bis (p-aminophenyl) ether (8.01 g, 40 mmol) (hereinafter referred to as ODA) in a reaction vessel having a nitrogen inlet tube. It stirred at room temperature and dissolved completely. Next, 1,2,3,4-cyclobutanetetracarboxylic dianhydride (hereinafter referred to as CBDA) (7.84 g, 40 mmol) and NMP (25 g) are added and stirred for 24 hours at room temperature to obtain polyamic acid. An NMP solution was obtained.

In Table 1, P-5 was prepared as follows. Polyamic acid was obtained in the same manner as P-1 except that 2,7-bis (4-aminophenylenesulfonyl) thianthrene (11.90 g, 25.71 mmol) and BT-100 (5.1 g, 25.76 mmol) were used. In addition, except that pyridine (6.11 g) and acetic anhydride (7.89 g) were used, imidation reaction and post-treatment were carried out similarly to P-2, and the GBL solution of P-5 was obtained. The imidation ratio was 91%. Here, 2,7-bis (4-aminophenylenesulfonyl) thianthrene is described in Macromolecules, Vol. 40, P4614, 2007].

In Table 1, the crosslinking agents X, Y, and Z are each X; Nippon Cytec Industries, Ltd. Cymel 303 (alkyl etherate of methylolmelamine condensate), Y; Nippon Carbide Co., Ltd. CHDVE (polyfunctional vinyl ether compound), Z; Nippon Carbide Co., Ltd. make BDVE (polyfunctional vinyl ether compound).

As the surfactant, a dimethylpolysiloxane-polyoxyalkylene copolymer (DC-190, manufactured by Toray Dow Corning Silicon Co., Ltd.) was used.

The compositions of A to L were diluted with a mixed solvent of cyclohexanone (CHN) and γ-butyrolactone (GBL), and the final composition is shown in Table 1. The composition used for each Example and each comparative example makes 100 mass parts of components except the above-mentioned solvent, and mix | blends the organic solvent by the mass part shown in Table 1.

3. Evaluation Method

In each Example and each comparative example, evaluation of embedding property, heating transparency, solvent resistance, and refractive index was performed as follows.

In either case, the substrate was one in which a hole having an opening diameter of 0.8 µm and a depth of 3 µm was formed in the SiO ₂ film formed on the silicon wafer described above.

Evaluation of embedding: The composition of each Example and each Comparative Example was applied to the substrate by spin coating method under the condition that the film thickness after embedding the pores was 0.6 µm, respectively, and this was carried out at 120 ° C for 1 minute and 180 ° C. 3 minutes at 250 degreeC for 5 minutes, and heat-dried sequentially, and it was set as the evaluation sample. And after cutting the board | substrate of each Example and the comparative example, respectively, the cross section of the hole was observed with a scanning electron microscope (SEM), the thing without voids in a composition was evaluated as having good embedding, and (circle) was attached to the table | surface. In the table, x is attached to the occurrence of voids.

Heating transparency evaluation: The resin composition was apply | coated and dried on the glass wafer similarly to the case of embedding evaluation, and the sample was created. A sample (described in the column at 250 ° C. in the table) sequentially heated for 1 minute at 120 ° C., 3 minutes at 180 ° C. for 5 minutes, and a sample heated at 265 ° C. for 5 minutes (the 265 ° C. in the table). 2 types of each of them) were created, respectively. The film thickness of each sample was measured with a stylus film thickness meter, and the transmittance at 400 nm of the sample obtained using an ultraviolet visible spectrophotometer was measured. The film thickness and the transmittance measured at each temperature are described.

Solvent resistance evaluation: The composition was apply | coated and dried similarly to the case of embedding evaluation, and the sample was created. After the obtained sample was immersed in acetone for 5 minutes, it dried at 120 degreeC for 1 minute, the external appearance (whitening, a crack), and film thickness residual rate were calculated | required and it was set as evaluation of solvent resistance. The solvent resistance described in Table 2 as (circle) that a crack was not recognized by visual evaluation about an external appearance, (circle) that a crack was recognized by SEM observation, (triangle | delta), and that the crack was clearly recognized by the naked eye. In addition, it was described in Table 2 as (circle) and the thing which whitened that whitening was not recognized. The film thickness residual ratio was calculated by the following formula using the film thickness determined by the tactile film thickness meter before and after acetone immersion and is shown in Table 2.

expression… Film thickness residual rate (%) = film thickness (100 micrometers) after acetone immersion / film thickness (micrometer) before acetone immersion

Refractive index: The refractive index in wavelength 633nm was calculated | required at 25 degreeC with the prism coupler using the sample created similarly to the sample for solvent tolerance evaluation.

3. 4. Evaluation result

The evaluation result of each Example and each comparative example was put together in Table 2.

In Table 2, in the cured product (Comparative Examples 1 and 2) formed by Composition A or Composition B containing no crosslinking agent, it was found that transparency after heating was good but solvent resistance was insufficient. Moreover, it turned out that embedding property is bad in the hardened | cured material (comparative example 3) formed with the composition K using the polymer which does not contain the structure of General formula (1). Moreover, especially in the polymer of General formula (2), in the hardened | cured material formed by the composition D-J and L containing the polymer whose l: m is the range of 70: 30-100: 0 (Examples 2-9), It turned out that the coating film excellent in transparency after a heating and solvent tolerance is obtained without all being accompanied by the fall of embedding property and refractive index.

The photoelectric conversion element of this invention can be applied to various uses, such as a digital camera, a video camera, a mobile phone with a camera, a scanner, a digital copier, and a facsimile. Moreover, according to the manufacturing method of the photoelectric conversion element of this invention, the photoelectric conversion element which has the optical waveguide part excellent in transparency and solvent tolerance can be manufactured easily.

10: substrate
20: photoelectric conversion unit
30, 30a: optical waveguide part
40, 40a: interlayer insulation layer
42: hole
50: on-chip lens
100: photoelectric conversion element

Claims (13)

Substrate,
A photoelectric conversion unit formed above the substrate,
An optical waveguide portion formed above the photoelectric conversion portion;
The said optical waveguide part contains sulfur, the polyimide whose refractive index in 633 nm is 1.60 or more, and the hardened | cured material of the composition containing a crosslinking agent. The method of claim 1,
The said hardened | cured material contains the structure represented by the following general formula (1):

(In General Formula (1), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4). The method of claim 2,
The said photoelectric conversion element whose said R is a C4-C12 tetravalent aliphatic or alicyclic hydrocarbon. 4. The method according to any one of claims 1 to 3,
The said crosslinking agent is at least 1 sort (s) chosen from the alkyl etherified product of methylol melamine, the alkyl etherified product of a methylol melamine condensate, and a polyfunctional vinyl ether compound. 4. The method according to any one of claims 1 to 3,
The said optical waveguide part has a columnar shape, The one end of the said columnar longitudinal direction is optically connected to the said photoelectric conversion part. The method of claim 5,
The cross section parallel to the said longitudinal direction of the said optical waveguide part WHEREIN: The length of the said longitudinal direction is 0.5 times or more and 10 times or less of the maximum length in the length of the direction perpendicular to the said longitudinal direction. Forming a photoelectric conversion section above the substrate;
Forming an interlayer insulating layer to cover the photoelectric conversion unit;
Forming a hole penetrating the upper surface of the photoelectric conversion part in the interlayer insulating layer;
Filling the hole with a composition containing a structure represented by the following General Formula (1) and a crosslinking agent;
A method for producing a photoelectric conversion element, comprising the step of curing the composition:

(In General Formula (1), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4). The method of claim 7, wherein
The said R is a manufacturing method of the photoelectric conversion element which is a C4-C12 tetravalent aliphatic or alicyclic hydrocarbon. The method according to claim 7 or 8,
In the said composition, when the component whole quantity except the organic solvent of the said composition is 100 mass%, 80 mass% or more and 99 mass% or less of the polymer containing the structure represented by the said General formula (1), and 1 mass of crosslinking agents The manufacturing method of the photoelectric conversion element contained% or more and 20 mass% or less. It includes the polymer which has a structure represented by following General formula (1), a crosslinking agent, and the organic solvent which can melt | dissolve these uniformly,
When the component whole quantity except the organic solvent is 100 mass%, 80 mass% or more and 99 mass% or less of the polymer containing the structure represented by the said General formula (1) contain 1 mass% or more and 20 mass% or less Composition for forming an optical waveguide:

(In General Formula (1), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4). The method of claim 10,
The composition for optical waveguide formation whose polymer containing the structure represented by the said General formula (1) is a polymer which has a structure represented by following General formula (2):

(In General Formula (2), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, and represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4, l and m represent an integer of 1 to 100,000 in total, and l: m is 50:50 to 100: 0. The method according to claim 10 or 11, wherein
The composition for forming an optical waveguide, wherein R is a tetravalent aliphatic or alicyclic hydrocarbon having 4 to 12 carbon atoms. Hardened | cured material of the polymer containing the structure represented by following General formula (1), and the composition containing a crosslinking agent:

(In General Formula (1), R <^1> respectively independently represents a C1-C3 alkyl group, a cyano group, or bivalent R <^1> couple | bonded, represents a bivalent sulfur atom, and a represents the integer of 0-4 each independently. , R represents a tetravalent organic group, n represents an integer of 1 to 4).

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