JP6807226B2 - Energy-sensitive compositions used to form flattening films or microlenses on a substrate, cured product manufacturing methods, cured products, microlens manufacturing methods, and CMOS image sensors. - Google Patents

Description

The present invention relates to an energy-sensitive composition used for forming a flattening film or a microlens on a substrate suitable for low-temperature curing, a method for producing a cured product, a cured product, a method for producing a microlens, and a CMOS image. Regarding the sensor.

Conventionally, a solid-state image sensor has been used in cameras, video cameras, and the like. A CCD (charge-coupled device) image sensor and a CMOS (complementary metal-axis semiconductor) image sensor are used in this solid-state image sensor. The image sensor is provided with a fine condensing lens (hereinafter referred to as a microlens) for the purpose of improving the condensing rate.

In forming such a microlens, a method called a thermal flow method and a method called an etching method are widely industrially adopted.
In the former thermal flow method, a photoresist film (a layer composed of a positive photosensitive resin composition or the like) is formed on the upper part of the CCD element or the like, and then exposure and development are sequentially performed on the element. Form an uneven pattern. This uneven pattern is made to flow by heating at a temperature equal to or higher than the glass transition point, and a hemispherical microlens pattern is formed by surface tension (see, for example, paragraph 0003 of Patent Document 1).
On the other hand, in the latter etching method, a positive photosensitive resin composition layer is formed on the lens material layer by using the positive photosensitive resin composition, and then the positive photosensitive resin composition layer is selectively exposed. Next, after removing the exposed portion by development, the positive photosensitive resin composition layer is fluidized by heat treatment to form a mask layer having a microlens pattern. Then, the lens material layer and the mask layer are dry-etched, and the shape of the microlens pattern is transferred to the lens material layer to obtain a microlens. Conventionally, as a positive photosensitive resin composition for producing a microlens pattern used for forming the mask layer, for example, an acrylic or novolac positive resist material has been used (see Patent Document 2). ..

Here, conventionally, an inorganic photodiode has been used in manufacturing a solid-state image sensor, but recently, from the viewpoint of miniaturization, high resolution, and high sensitivity of the device, a solid-state photodiode using an organic photodiode has been used. Is being developed. However, there is a concern that organic photodiodes are easily decomposed at temperatures exceeding 200 ° C., for example, and the current situation remains that technical problems remain.
From such a viewpoint, a material (for example, a lens forming material, a flattening film, etc.) constituting a solid-state image sensor using an organic photodiode is required to have low-temperature curability (for example, 200 ° C. or lower).
Further, in the production of a solid-state image sensor using a conventional inorganic photodiode, a color filter layer is required from the viewpoint of obtaining color information, but the color filter layer has a relatively large amine content and is on the color filter layer. In addition, when the lens material layer or the flattening film is formed, the curability of the lens material layer or the flattening film tends to be impaired due to the influence of the amine, and the lens material layer or the flattening film is stably cured regardless of the surrounding environment. There is a need for materials to be used.
Conventional compositions that form lens material layers or flattening films have not fully met these requirements.

JP-A-2007-33518 Japanese Unexamined Patent Publication No. 2013-117662

In view of the above-mentioned problems of the prior art, the present invention produces an energy-sensitive composition and a cured product used for forming a flattening film or a microlens on a substrate provided with an organic photodiode, which is excellent in low-temperature curability. It is an object of the present invention to provide a method, a cured product, a method for manufacturing a microlens, and a CMOS image sensor.

The present inventors have provided an acid crosslinkable structure in the composition while using a resin having a structural unit derived from a hydroxyl group-containing (meth) acrylic acid derivative in the energy-sensitive composition, and further have an acid generation temperature in a specific range. By combining the thermal acid generators having the above, the present invention has been completed by finding that it is excellent in low temperature curability even in an amine environment in which a color filter layer is present in the layer directly below.
That is, the present invention is as follows.

A first aspect of the present invention is an energy sensitive composition used to form a flattening film or microlens on a substrate.
The energy-sensitive composition contains (A) a resin and (B) a thermoacid generator.
The resin (A) has a structural unit (a1) derived from a hydroxyl group-containing (meth) acrylic acid derivative and has a structural unit (a1).
The acid generation temperature of the above (B) thermoacid generator observed in differential scanning calorimetry (DSC) is 100 ° C or higher and 200 ° C or lower.
The energy sensitive composition further comprises (C) an acid crosslinkable structure.
The (C) acid crosslinkable structure is a partial structure of the (C1) polymer or the (C2) monomer.
The (C1) polymer is an energy-sensitive composition which may be the (A) resin.

A second aspect of the present invention includes a resin layer forming step of forming a resin layer by applying the energy-sensitive composition according to the first aspect on a substrate, and a heating step of heating the resin layer. , A method for producing a cured product.
A third aspect of the present invention is a cured product in which the energy-sensitive composition according to the first aspect is crosslinked.

A fourth aspect of the present invention includes a lens material layer forming step of applying the energy-sensitive composition according to the first aspect on a substrate and cross-linking the resin layer obtained by heating to form a lens material layer.
A lens pattern forming step of forming a resist pattern on the lens material layer and then reflowing the resist pattern by heating to form a lens pattern.
This is a method for manufacturing a microlens, which includes a shape transfer step of dry-etching the lens material layer and the lens pattern using the lens pattern as a mask to transfer the shape of the lens pattern to the lens material layer.

A fifth aspect of the present invention is on a substrate provided with at least a base material, a solid-state image sensor formed on the base material, and a color filter formed corresponding to the solid-state image pickup element. A resin layer forming step of applying the energy-sensitive composition according to the first aspect to form a resin layer,
A microlens pattern forming step of forming a microlens pattern corresponding to the solid-state image sensor and the color filter by pattern-exposing and developing the resin layer.
A bleaching process in which the above microlens pattern is fully exposed and bleached,
A thermal flow step of heating the bleached microlens pattern to cause a thermal flow,
This is a method for manufacturing a microlens, which includes a curing step of forming a microlens by cross-linking the thermally flowed microlens pattern by heating.

A sixth aspect of the present invention is a CMOS image sensor including the cured product according to the third aspect.

The energy-sensitive composition used for forming a flattening film or a microlens on the substrate of the present invention is excellent in low-temperature curability even in an amine environment in which a color filter layer is present in a layer directly below.
According to the present invention, it is possible to provide a method for producing a cured product, a method for producing a cured product, a microlens, and a CMOS image sensor using the above energy-sensitive composition.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the scope of the object of the present invention. ..

<Energy sensitive composition used to form a flattening film or microlens on a substrate>
The energy-sensitive composition used for forming a flattening film or a microlens on a substrate according to the first aspect contains (A) a resin and (B) a thermoacid generator.
The resin (A) has a structural unit (a1) derived from a hydroxyl group-containing (meth) acrylic acid derivative and has a structural unit (a1).
The acid generation temperature of the above (B) thermoacid generator observed in differential scanning calorimetry (DSC) is 100 ° C or higher and 200 ° C or lower.
The energy sensitive composition further comprises (C) an acid crosslinkable structure.
The (C) acid crosslinkable structure is a partial structure of the (C1) polymer or the (C2) monomer.
The (C1) polymer may be the (A) resin.
The energy-sensitive composition according to the first aspect may be a composition sensitive to any energy such as heat, light (light), and radiation, but a heat-sensitive composition is preferable.
Further, the acid crosslinkable structure (C) means a chemical structure that is crosslinked by the action of an acid, and can improve the curability of the flattening film or the microlens to be formed.

((A) resin)
The resin (A) has a structural unit (a1) derived from a hydroxyl group-containing (meth) acrylic acid derivative, and can contribute to the improvement of low-temperature curability.
In the present specification, examples of the hydroxyl group-containing (meth) acrylic acid derivative include hydroxyl group-containing (meth) acrylic acid ester and hydroxyl group-containing (meth) acrylic acid amide.
The hydroxyl group-containing (meth) acrylic acid derivative is not the (meth) acrylic acid itself, but the hydroxyl group may be a "-OH group" provided as a terminal of an acidic functional group such as "carboxylic acid" or "sulfonic acid". Good.
Here, when the hydroxyl group-containing (meth) acrylic acid derivative has an acidic functional group such as "carboxylic acid" or "sulfonic acid", the hydroxyl group-containing (meth) acrylic acid derivative uses (meth) acrylic acid as a starting material. It can be obtained by subjecting a compound having an acidic functional group and a hydroxyl group to a (meth) acrylic acid by a dehydration condensation reaction.
However, from the viewpoint of improving the storage stability of the energy-sensitive composition, the structural unit (a1) preferably has a structure in which a hydroxyl group is bonded to an aromatic ring or an aliphatic hydrocarbon group.
The "aromatic ring" and the "aliphatic hydrocarbon group" here are preferably at least divalent, and at least one bond is bonded to the hydroxyl group, but the other bond is used. It can be defined as binding to the following atoms. That is, when the (meth) acrylic acid derivative is a (meth) acrylic acid ester or a (meth) acrylic acid amide, the "aromatic ring" and the "aliphatic hydrocarbon group" are oxygen atoms constituting this ester group. It can be defined as binding to the nitrogen atoms that make up the amide group.

（上記式（１）中、Ｒ_０は水素原子又はメチル基を表し、Ｘは酸素原子（−Ｏ−）又は−ＮＨ−基を表し、Ｙは単結合又はアルキレン基を表し、Ｒ_１はアルキル基を表す。ａは１〜５の整数を表し、ｂは０〜４の整数を表しａ＋ｂは５以下である。）
上記式（１）中、Ｘは酸素原子であることが好ましい。
Ｙのアルキレン基としては、炭素原子数１〜５（好ましくは炭素原子数１〜４、より好ましくは炭素原子数１〜３、更に好ましくは炭素原子数１又は２）のアルキレン基が挙げられ、具体的には、メチレン基、エチレン基、プロピレン基、ブチレン基等が挙げられる。
Ｒ_１のアルキル基としては、炭素原子数１〜５（好ましくは炭素原子数１〜４、より好ましくは炭素原子数１〜３、更に好ましくは炭素原子数１又は２）のアルキル基が挙げられ、具体的には、メチル基、エチル基、プロピル基、ｉ−プロピル基、ブチル基、ｉ−ブチル基、ｔ−ブチル基、ペンチル基等が挙げられる。
ａは１〜３の整数であることが好ましく、１又は２であることがより好ましく、１であることが更に好ましい。
なお、本明細書中において用いられる「構造単位」の用語は、（Ａ）樹脂を構成する各ユニットを指すものであり、（Ａ）樹脂を重合する際のモノマー（単量体）のモル数に応じ、その構造単位のモル％を定義することができる。 Examples of the aromatic ring to which the hydroxyl group is bonded include an aromatic ring having 6 to 12 carbon atoms, and specific examples thereof include a benzene ring and a naphthalene ring, and a benzene ring is preferable.
The aliphatic hydrocarbon group to which the hydroxyl group is bonded includes linear, branched or cyclic carbon atoms 1 to 10 (preferably carbon atoms 1 to 5, more preferably carbon atoms 1 to 3, and even more preferably. It is preferably a divalent aliphatic hydrocarbon group having 1 or 2) carbon atoms, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a cyclopentylene group, and a cyclohexylene group. More preferably, it is a linear divalent aliphatic hydrocarbon group.
The structural unit (a1) is preferably a structural unit represented by the following formula (1).

(In the above formula (1), R ₀ represents a hydrogen atom or a methyl group, X represents an oxygen atom (-O-) or a -NH- group, Y represents a single bond or an alkylene group, and R ₁ is an alkyl. Represents a group. A represents an integer of 1 to 5, b represents an integer of 0 to 4, and a + b is 5 or less.)
In the above formula (1), X is preferably an oxygen atom.
Examples of the alkylene group of Y include alkylene groups having 1 to 5 carbon atoms (preferably 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and further preferably 1 or 2 carbon atoms). Specific examples thereof include a methylene group, an ethylene group, a propylene group, and a butylene group.
Examples of the alkyl group of R ₁ include alkyl groups having 1 to 5 carbon atoms (preferably 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and further preferably 1 or 2 carbon atoms). Specific examples thereof include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, an i-butyl group, a t-butyl group, a pentyl group and the like.
a is preferably an integer of 1 to 3, more preferably 1 or 2, and even more preferably 1.
The term "structural unit" used in the present specification refers to (A) each unit constituting the resin, and (A) the number of moles of the monomer (monomer) when polymerizing the resin. Therefore, the molar% of the structural unit can be defined.

The structural unit (a1) is 1 to 75 mol% with respect to all the structural units in the resin (A) from the viewpoint of improving the long-term reliability, transmittance, etc. of the flattening film or microlens to be formed. It is preferably 1 to 60 mol%, more preferably 5 to 50 mol%.

（上記式（２）中、Ｒ_０は水素原子又はメチル基を表し、Ｘは酸素原子（−Ｏ−）又は−ＮＨ−基を表し、Ｙは単結合又はアルキレン基を表し、Ｒ_２は酸架橋性を有する１価の有機基を表す。） The (C) acid crosslinkable structure may be a partial structure of the (C1) polymer. In this case, it is more preferable that the (C) acid-crosslinkable structure is a partial structure of the (A) resin.
When the (C) acid-crosslinkable structure is a partial structure of the (C1) polymer, the (C) acid-crosslinkable structure is selected from the group consisting of an oxylanyl group, an oxetanyl group, an alicyclic epoxy group and an alkoxymethyl group. It is preferably at least one group.
When the (C) acid-crosslinkable structure is a partial structure of the (A) resin, the (A) resin is represented by the following formula (2) as a structural unit having the (C) acid-crosslinkable structure. It is preferable to include structural units.

(In the above formula (2), R ₀ represents a hydrogen atom or a methyl group, X represents an oxygen atom (-O-) or a -NH- group, Y represents a single bond or an alkylene group, and R ₂ is an acid. Represents a monovalent organic group having crosslinkability.)

It is preferable that X is an oxygen atom.
Examples of the alkylene group of Y include alkylene groups having 1 to 5 carbon atoms (preferably 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and further preferably 1 or 2 carbon atoms). Specific examples thereof include a methylene group, an ethylene group, a propylene group, and a butylene group.
Examples of the monovalent organic group having an acid crosslinkability for R ₂ include at least one group selected from the group consisting of an oxylanyl group, an oxetanyl group, an alicyclic epoxy group and an alkoxymethyl group.
The structural unit represented by the above formula (2) is preferably 20 to 80 mol%, more preferably 30 to 75 mol%, and 40, based on all the structural units in the resin (A). It is more preferably ~ 70 mol%.

The resin (A) has a structural unit represented by the above formula (1) as the structural unit (a1) and a structure represented by the above formula (2) as the structural unit having the acid crosslinkable structure (C). It is more preferable to include a unit.

（上記式（３）中、Ｒ_０は水素原子又はメチル基を表し、Ｒ_３はそれぞれ独立して水素原子、アルキル基及びアリール基からなる群から選ばれる基である。）
Ｒ_３についてのアルキル基としては、置換基を有していてもよく、炭素原子数１〜１２（好ましくは炭素原子数１〜８、より好ましくは炭素原子数１〜４、更に好ましくは炭素原子数１〜３）のアルキル基が挙げられ、具体的には、メチル基、エチル基、プロピル基、ｉ−プロピル基、ブチル基、ｉ−ブチル基、ｔ−ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基等が挙げられる。
Ｒ_３についてのアリール基としては、置換基を有していてもよく、炭素原子数６〜１２（好ましくは炭素原子数６〜１０）のアリール基が挙げられ、具体的には、フェニル基、ナフチル基等が挙げられ、フェニル基であることが好ましい。
上記構造単位（ａ２）を（Ａ）樹脂に含有させる場合、その含有量は、上記（Ａ）樹脂における全構造単位に対して、３０〜６０モル％であることが好ましく、３５〜５５モル％であることがより好ましく、４０〜５０モル％であることが更に好ましい。 The resin (A) improves the thermal decomposition point of the resin, further improves the long-term reliability of the flattening film or microlens formed, the transmittance, etc., and improves the refractive index of the flattening film or microlens formed. From the viewpoint of the above, it is preferable to further contain the structural unit (a2) represented by the following formula (3).

(In the above formula (3), R ₀ represents a hydrogen atom or a methyl group, and R ₃ is a group independently selected from the group consisting of a hydrogen atom, an alkyl group and an aryl group.)
The alkyl group for R ₃ may have a substituent and has 1 to 12 carbon atoms (preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably carbon atoms. Alkyl groups of Nos. 1-3) can be mentioned, specifically, methyl group, ethyl group, propyl group, i-propyl group, butyl group, i-butyl group, t-butyl group, pentyl group, hexyl group, Examples thereof include a heptyl group, an octyl group, a nonyl group and a decyl group.
The aryl group for R ₃ may have a substituent and includes an aryl group having 6 to 12 carbon atoms (preferably 6 to 10 carbon atoms), and specifically, a phenyl group. Examples thereof include a naphthyl group, and a phenyl group is preferable.
When the structural unit (a2) is contained in the resin (A), the content thereof is preferably 30 to 60 mol% with respect to all the structural units in the resin (A), and is 35 to 55 mol%. Is more preferable, and 40 to 50 mol% is further preferable.

The weight average molecular weight of the resin (A) is preferably 2000 to 100,000, more preferably 3,000 to 50,000, and even more preferably 5,000 to 50,000.
The weight average molecular weight of the resin (A) is defined as a polystyrene-equivalent value measured by GPC.

The resin (A) can be produced by either random polymerization or block polymerization.
Further, the resin (A) may be used alone or in combination of two or more.
The content of the resin (A) is preferably 30 to 99.8% by mass, more preferably 50 to 99.6% by mass, and 70 to 99.%, Based on the total solid content of the composition. It is particularly preferable to set it to 5% by mass.
Further, as described later, the energy-sensitive composition may contain a photosensitizer, but in that case, the content of the resin (A) is 30 to 95% by mass based on the total solid content of the composition. It is preferably 50 to 90% by mass, more preferably 55 to 80% by mass, and particularly preferably 55 to 80% by mass.

((B) Thermoacid generator)
The above-mentioned thermal acid generator (B) does not generate an excessive amount of acid in the prebaking described later, and also generates acid well even at low temperature curing suitable for using an organic photodiode, etc., to form a good permanent film. Therefore, the acid generation temperature observed by the measurement using DSC is 100 ° C. or higher and 200 ° C. or lower, preferably 100 ° C. or higher and 180 ° C. or lower, more preferably 110 ° C. or higher and 150 ° C. or lower, 120. It is more preferably ° C. or higher and 150 ° C. or lower, and particularly preferably 125 ° C. or higher and 145 ° C. or lower.
In the present specification, the acid generation temperature of the thermal acid generator (B) is increased from 30 ° C. to 300 ° C. under the condition of a temperature rise rate of 10 ° C./min because the acid generation reaction is an endothermic reaction. It is defined as the peak temperature at the maximum endothermic peak of the DSC curve obtained when warmed.
Examples of the device used for measuring the acid generation temperature include Q2000 (manufactured by TA Instruments).

（上記式（４）中、Ｒ_４はそれぞれ独立して水素原子又は有機基であり、Ｘ⁻はハロゲン化物イオン、水酸化物イオン、硝酸イオン、ボレート、有機カルボン酸イオン、及び有機スルホン酸イオンよりなる群から選ばれる一種である。） The thermal acid generator (B) is an ammonium salt; a sulfonium salt such as a triphenylsulfonium salt, a tri-p-tolylsulfonium salt, a 4- (phenylthio) phenyldiphenylsulfonium salt; Salt, bis (4-dodecylphenyl) iodonium salt, bis (4-methoxyphenyl) iodonium salt, (4-octyloxyphenyl) phenyliodonium salt, bis (4-decyloxy) phenyliodonium salt, 4- (2-hydroxytetra Examples thereof include decyloxy) phenylphenyl iodonium salt, 4-isopropylphenyl (p-tolyl) iodonium salt, and iodonium salt such as 4-isobutylphenyl (p-tolyl) iodonium salt.
The thermal acid generator (B) is preferably a quaternary ammonium salt from the viewpoint of achieving the acid generation temperature and the surface wettability of the flattening film or the like to be formed, and is preferably the following formula (4). ) Is more preferable.

(In the above formula (4), R ₄ is an independent hydrogen atom or an organic group, and X ⁻ is a halide ion, a hydroxide ion, a nitrate ion, a borate, an organic carboxylic acid ion, and an organic sulfonic acid ion. It is a kind selected from the group consisting of.)

Examples of the organic group for R ₄ include an organic group having 1 to 30 carbon atoms (preferably 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms), and an alkyl group, an aryl group, and an aralkyl group. And so on.
The alkyl group for R ₄ may have a substituent and includes an alkyl group having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms). Specifically, methyl group, ethyl group, propyl group, i-propyl group, butyl group, i-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl. Group etc. can be mentioned.
The aralkyl group for R ₄ may have a substituent and includes an aralkyl group having 7 to 13 carbon atoms (preferably 7 to 11 carbon atoms), such as a benzyl group, a phenethyl group and a naphthylmethyl group. Examples thereof include a benzyl group and a p-methoxybenzyl group, and a paramethoxybenzyl group is more preferable.
Examples of the cation portion in the above formula (4) include paramethoxybenzyldimethylphenylammonium, benzyldimethylphenylammonium, N, N-dimethylanilinium and the like, and p-methoxybenzyldimethylphenylammonium is preferable.

Examples of the halide ion for X ⁻ include a fluorinated ion, a chlorinated ion, a brominated ion and the like, and a fluorinated ion or a chlorinated ion is preferable, and a fluorinated ion is more preferable.
X ^- borate as the tetrakis (pentafluorophenyl) borate of _{([B (C 6 F 5} ) 4] -), tetrakis [(trifluoromethyl) phenyl] borate _{([B (C 6 H 4} CF 3) 4 ] ^- ), Difluorobis (pentafluorophenyl) borate ([(C ₆ F ₅ ) ₂ BF ₂ ] ^- ), trifluoro (pentafluorophenyl) borate ([(C ₆ F ₅ ) BF ₃ ] ^- ), tetrakis (Difluorophenyl) borate ([B (C ₆ H ₃ F ₂ ) ₄ ] ⁻ ) and the like can be mentioned. Of these, tetrakis (pentafluorophenyl) borate ([B (C ₆ F ₅ ) ₄ ] ⁻ ) is particularly preferable.
Examples of the organic carboxylic acid ion for X ⁻ include acetate ion, propionic acid ion, maleate ion, lactate ion, malate ion, succinate ion, glycolate ion, tartrate ion, benzoate ion and the like.
X ^- is an organic sulfonate ion for, methanesulfonate ion, benzenesulfonate ion, trifluoromethanesulfonate ion (simply "TfO ^-"., Sometimes referred to as), p-toluenesulfonate ion (simply "TsO ^- ”May be indicated.) Etc. can be mentioned.
The X ⁻ is preferably an organic sulfonic acid ion or a borate, and more preferably a trifluoromethanesulfonic acid ion or a tetrakis (pentafluorophenyl) borate ([B (C ₆ F ₅ ) ₄ ] ⁻ ).

The content of the (B) thermal acid generator is preferably 0.01 to 2.0 parts by mass, and 0.05 to 1.5 parts by mass with respect to 100 parts by mass of the resin (A). More preferably, it is more preferably 0.1 to 1.0 part by mass.
The above (B) thermoacid generator can be used alone or in combination of two or more.

((C) Acid crosslinkable structure)
The (C) acid-crosslinkable structure is a partial structure of (C1) polymer or (C2) monomer.
When the (C) acid crosslinkable structure is a partial structure of the (C1) polymer, the (C1) polymer does not have to be the (A) resin, but as described above, the (C1) polymer is , The resin (A) described above is preferable.
When the (C) acid crosslinkable structure is a partial structure of the (C1) polymer and the (C1) polymer is not the (A) resin, the (C1) polymer may be, for example, a melamine resin. Examples thereof include urea resin, guanamine resin, glycoluril-formaldehyde resin, succinylamide-formaldehyde resin, and ethyleneurea-formaldehyde resin. More specifically, methoxymethylated melamine resin, propoxymethylated melamine resin, butoxymethylated melamine resin, methoxymethylated urea resin, ethoxymethylated urea resin, propoxymethylated urea resin, butoxymethylated urea resin and the like can be mentioned. Be done.
The polymer (C1) is also preferably a resin containing a structural unit having a partial structure having two or more N-methylol groups or N-methoxymethyl groups or a structural unit represented by the above formula (2).
In the present specification, the N-methylol group or N-methoxymethyl group means a methylol group or a methoxymethyl group covalently bonded to a nitrogen atom.
When the polymer (C1) is not the resin (A), the content of the structural unit represented by the formula (2) in the polymer (C1) is 30 with respect to all the structural units in the polymer (C1). It is preferably ~ 100 mol%, more preferably 50 ~ 90 mol%, still more preferably 60-80 mol%.
When the polymer (C1) is not the resin (A), the other structural units in the polymer (C1) are not particularly limited, but may include structural units represented by the formula (3). Good.
When the (C) acid crosslinkable structure is not a partial structure of the (A) resin, the content of the (C1) polymer is 0.01 to 50 parts by mass with respect to 100 parts by mass of the (A) resin. It is preferably 0.05 to 45 parts by mass, and even more preferably 0.1 to 40 parts by mass.

When the (C) acid crosslinkable structure is a partial structure of the (C2) monomer, the (C2) monomer is a monomer having a partial structure having two or more N-methylol groups or N-methoxymethyl groups, or an oxylanyl group. , Monomers having at least one group selected from the group consisting of an oxetanyl group, an alicyclic epoxy group and an alkoxymethyl group.
As a monomer having a partial structure having two or more N-methylol groups or N-methoxymethyl groups, a compound in which two or more hydrogen atoms bonded to the nitrogen atom of melamine are substituted with methylol groups or methoxymethyl groups, respectively. Can be mentioned.
When the (C) acid crosslinkable structure is a partial structure of the (C2) monomer, the content of the (C2) monomer shall be 0.01 to 50 parts by mass with respect to 100 parts by mass of the (A) resin. , More preferably 0.05 to 45 parts by mass, and even more preferably 0.1 to 40 parts by mass.

(Photosensitive agent)
The energy-sensitive composition according to the first aspect may further contain a photosensitizer.
As this photosensitizer, a quinonediazide group-containing compound can be used.
Examples of the quinone diazide group-containing compound include 2,3,4-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,6-trihydroxybenzophenone, and the like. 2,3,4-trihydroxy-2'-methylbenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,3', 4,4 ', 6-Pentahydroxybenzophenone, 2,2', 3,4,4'-Pentahydroxybenzophenone, 2,2', 3,4,5-Pentahydroxybenzophenone, 2,3', 4,4', 5 Polyhydroxybenzophenones such as', 6-hexahydroxybenzophenone, 2,3,3', and 4,4', 5'-hexahydroxybenzophenone; bis (2,4-dihydroxyphenyl) methane, bis (2,3) , 4-Trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (2', 4'-dihydroxy Phenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (2', 3', 4'-trihydroxyphenyl) propane, 4,4'-{1- [4- [2- [2-] (4-Hydroxyphenyl) -2-propyl] phenyl] ethylidene} bisphenol, and 3,3'-dimethyl-{1- [4- [2- (3-methyl-4-hydroxyphenyl) -2-propyl] phenyl ] Echiliden} Bisphenols and other bis [(poly) hydroxyphenyl] alkanes; tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-) Hydroxy-2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl)- 2-Hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, and bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane Tris (hydroxyphenyl) methanes such as or methyl substituents thereof; bis (3-cyclohexyl-4-hydroxyphenyl) -3- Hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy- 2-Methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl)- 4-Hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -4-hydroxyphenylmethane, bis (5-) Cyclohexyl-4-hydroxy-3-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) ) -4-Hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -2-hydroxyphenylmethane, and bis Bis (cyclohexylhydroxyphenyl) (hydroxyphenyl) methanes such as (5-cyclohexyl-2-hydroxy-4-methylphenyl) -4-hydroxyphenylmethane or methyl substituents thereof; phenol, p-methoxyphenol, dimethylphenol, Compounds with hydroxyl or amino groups such as hydroquinone, naphthol, pyrocatechol, pyrogallol, pyrogallol monomethyl ether, pyrogallol-1,3-dimethyl ether, gallic acid, aniline, p-aminodiphenylamine, and 4,4'-diaminobenzophenone; A complete ester compound, a partial ester compound, an amidate, or a quinonediazide group-containing sulfonic acid with a homopolymer of novolak, pyrogallol-acetone resin, and p-hydroxystyrene or a copolymer with a monomer capable of copolymerizing with the homopolymer. Examples thereof include partially amidates. These photosensitizers may be used alone or in combination of two or more.

The quinone diazide group-containing sulfonic acid is not particularly limited, and for example, naphthoquinone diazido sulfonic acid such as naphthoquinone-1,2-diazide-5-sulfonic acid and naphthoquinone-1,2-diazide-4-sulfonic acid; orthoanthra. Examples thereof include quinonediazide sulfonic acid, and naphthoquinonediazide sulfonic acid is preferable.

The method for producing the above ester compound as a photosensitizer is not particularly limited, and for example, a quinone diazide group-containing sulfonic acid is added as a sulfonyl chloride such as naphthoquinone-1,2-diazide-sulfonyl chloride to form a dioxane. Examples thereof include a method of completely esterifying or partially esterifying by condensing in the presence of an alkali such as triethanolamine, alkali carbonate, or alkali hydrogen carbonate in a solvent.

From the viewpoint of the sensitivity of the composition, the content of the photosensitizer is preferably 1 to 50 parts by mass, more preferably 5 to 40 parts by mass, based on 100 parts by mass of the resin (A). It is more preferably about 30 parts by mass.

(Surfactant)
The energy-sensitive composition according to the first aspect may or may not further contain a surfactant.
Examples of the surfactant include a fluorine atom-containing surfactant and a silicon atom-containing surfactant. As the fluorine atom-containing surfactant, a fluorine-based surfactant having an alkylene oxide chain is preferable, and a silicon atom-containing interface is preferable. As the activator, a polysiloxane-based surfactant having an alkylene oxide chain is preferable.
Preferable specific examples of the fluorine atom-containing surfactant include, for example, PF-636, PF-6320, PF-6656, PF-6520 (trade names, manufactured by Omniova) of the Polyfox series.
Preferable specific examples of the silicon atom-containing surfactant include BYK-307, BYK-333, BYK-378 (trade names, all manufactured by Big Chemie) and the like.
The content of the surfactant is preferably 0.01 part by mass to 0.2 part by mass with respect to 100 parts by mass of the resin (A). More preferably, it is 0.03 part by mass to 0.1 part by mass.

(Organic solvent)
The energy-sensitive composition according to the first aspect may contain an organic solvent. The type of the organic solvent is not particularly limited as long as it does not impair the object of the present invention, and can be appropriately selected and used from the organic solvents capable of dispersing or dissolving each component.

Specific examples of organic solvents include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, and dipropylene. Polyhydric alcohols such as glycol, dipropylene glycol monoacetate monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, monophenyl ether and derivatives thereof; cyclic ethers such as dioxane; ethyl acetate, methyl lactate, lactic acid Ethyl, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, 2- Ethers such as ethyl hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate; toluene, xylene, etc. Aromatic hydrocarbons; etc. These may be used alone or in combination of two or more.

The amount of the organic solvent used is not particularly limited, but is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate or the like. Specifically, the energy-sensitive composition is used so that the solid content concentration is in the range of 5 to 60% by mass, preferably 10 to 55% by mass.

(Other ingredients)
Various additives such as a sensitizer and an antifoaming agent may be added to the energy-sensitive composition according to the first aspect. Examples of the sensitizer include compounds having a phenolic hydroxyl group having a molecular weight of 1000 or less. The defoaming agent may be a conventionally known one, and examples thereof include silicone-based compounds and fluorine-based compounds.

<Manufacturing method of cured product>
The method for producing a cured product according to the second aspect includes a resin layer forming step of forming a resin layer by applying an energy-sensitive composition on a substrate, and a heating step of heating the resin layer.

Examples of the base material include an image element including a photodiode (organic photodiode, inorganic photodiode, etc.), a silicon wafer provided with a color filter layer, and a substrate such as a silicon wafer on which an antireflection film is further formed. Can be mentioned.
The method of applying the energy-sensitive composition is not particularly limited, and conventionally known methods can be used. When the energy-sensitive composition is a solid or a high-viscosity gel, for example, a method of supplying a predetermined amount of the energy-sensitive composition onto a substrate and then pressing the energy-sensitive composition while appropriately heating it. Therefore, a resin layer can be formed. When the energy-sensitive composition is a liquid (for example, when the energy-sensitive composition contains an organic solvent), for example, a contact transfer type coating device such as a roll coater, a reverse coater, a bar coater, a slit coater, or a spinner. Using a non-contact coating device such as (rotary coating device) or a curtain flow coater, the energy-sensitive composition is applied onto a substrate to a desired thickness to form a coating film, and as appropriate. The resin layer can be formed by removing the organic solvent in the coating film by heat treatment (pre-baking (post-apply baking (PAB)) treatment).
The method of prebaking is not particularly limited, and for example, (i) drying using a hot plate at a temperature of 80 ° C. to 120 ° C. (preferably 85 to 100 ° C., more preferably 85 to 95 ° C.) for 60 seconds to 120 seconds. (Ii) A method of leaving the solvent at room temperature for several hours to several days, or (iii) a method of putting it in a warm air heater or an infrared heater for several tens of minutes to several hours to remove the solvent.

From the viewpoint of low-temperature curing suitable for using an organic photodiode or the like, the heating temperature in the heating step is preferably 200 ° C. or lower, more preferably 100 ° C. or higher and 180 ° C. or lower, and 110 ° C. or higher and 150 ° C. It is more preferably 120 ° C. or higher and 150 ° C. or lower.
Examples of the cured product produced by the production method according to the second aspect include a flattening film for an image sensor and a display.

<Hardened body>
The cured product according to the third aspect is a cured product in which the energy-sensitive composition according to the first aspect is crosslinked.
The cross-linking can be achieved by the heating step in the second aspect.
The cured product according to the third aspect can have a cross-linking rate of at least 70%, preferably 80% or more, and more preferably 90% or more.
The cured product according to the third aspect can have a pencil hardness of 3H or more according to JIS K 5600-5-4, and is preferably 4H or more.
When the cured product is in the form of a film, the film thickness is preferably in the range of 50 nm to 5.0 μm, more preferably 200 nm to 4.0 μm.
Examples of the cured product include an image sensor, a flattening film for a display, and the like.

<Manufacturing method of microlens>
The method for producing a microlens according to a fourth aspect is a lens material layer for forming a lens material layer by applying the energy-sensitive composition according to the first aspect on a substrate and cross-linking the resin layer obtained by heating. The formation process and
A lens pattern forming step of forming a resist pattern on the lens material layer and then reflowing the resist pattern by heating to form a lens pattern.
This includes a shape transfer step of dry-etching the lens material layer and the lens pattern using the lens pattern as a mask to transfer the shape of the lens pattern to the lens material layer.

Examples of the base material include an image element including a photodiode (organic photodiode, inorganic photodiode, etc.), a silicon wafer provided with a color filter layer, and a substrate such as a silicon wafer on which an antireflection film is further formed. Can be mentioned.
The method of applying the energy-sensitive composition to obtain a resin layer is not particularly limited, and for example, a contact transfer type coating device such as a roll coater, a reverse coater, a bar coater, or a slit coater, or a spinner (rotary coating device). , A non-contact coating device such as a curtain flow coater is used to apply the above energy-sensitive composition onto a substrate so as to have a desired film thickness to form a coating film, and heat-treat (pre-bake (post)) as appropriate. A resin layer can be formed by removing the organic solvent in the coating film by (apply bake (PAB)) treatment).
The method of prebaking is not particularly limited, and for example, (i) drying using a hot plate at a temperature of 80 ° C. to 120 ° C. (preferably 85 to 100 ° C., more preferably 85 to 95 ° C.) for 60 seconds to 120 seconds. (Ii) A method of leaving the solvent at room temperature for several hours to several days, or (iii) a method of putting it in a warm air heater or an infrared heater for several tens of minutes to several hours to remove the solvent.

From the viewpoint of low-temperature curing suitable for using an organic photodiode or the like, cross-linking by heating in the lens material layer forming step is preferably performed at a temperature of 200 ° C. or lower, and more preferably 100 ° C. or higher and 180 ° C. or lower. It is more preferably 110 ° C. or higher and 150 ° C. or lower, and particularly preferably 120 ° C. or higher and 150 ° C. or lower.
The film thickness of the lens material layer to be formed is preferably in the range of 100 nm to 4.0 μm, more preferably 400 nm to 2.0 μm.

The heating conditions for reflow in the lens pattern forming step differ depending on the type of each component in the composition, the mixing ratio, the coating film thickness, and the like, but the heating temperature is, for example, 60 to 150 ° C. (preferably 70 to 140 ° C.). The heating time is, for example, about 0.5 to 60 minutes (preferably 1 to 50 minutes).
The film thickness of the resist pattern is preferably in the range of 100 nm to 4.0 μm, more preferably 400 nm to 2.0 μm.

The dry etching in the shape transfer step is not particularly limited, and examples thereof include dry etching by plasma (oxygen, argon, CF _4, etc.), corona discharge, and the like.

The method for manufacturing a microlens according to a fifth aspect is a substrate including at least a base material, a solid-state image sensor formed on the base material, and a color filter formed corresponding to the solid-state image sensor. A resin layer forming step of applying the energy-sensitive composition according to the first aspect to form a resin layer,
A microlens pattern forming step of forming a microlens pattern corresponding to the solid-state image sensor and the color filter by pattern-exposing and developing the resin layer.
A bleaching process in which the above microlens pattern is fully exposed and bleached,
A thermal flow step of heating the bleached microlens pattern to cause a thermal flow,
It includes a curing step of forming a microlens by cross-linking the thermally flowed microlens pattern by heating.
In the method for producing a microlens here, a composition containing a photosensitizer is usually used as an energy-sensitive composition.

In the resin layer forming step, a resin layer having a film thickness in the range of 100 nm to 4.0 μm, more preferably 400 nm to 2.0 μm is formed by applying and drying by a known coating means such as a spin coater.
In order to form a microlens pattern, an active energy ray such as ultraviolet rays or excimer laser light is irradiated through a mask to partially expose the lens. The energy dose to be irradiated varies depending on the composition of the energy-sensitive composition, but is preferably about 30 to 2000 mJ / cm ² , for example.
As the developer used in the development treatment, for example, an organic alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) aqueous solution or an inorganic alkaline aqueous solution such as sodium hydroxide, potassium hydroxide, sodium metasilicate, and sodium phosphate is used. By the development process, the exposed portion is dissolved and removed to form a microlens pattern.
The transparency of the microlens pattern can be improved by the bleaching process.
For bleaching, it is preferable to irradiate ultraviolet rays having a wavelength of 300 to 450 nm.

The thermal flow temperature in the thermal flow step is a temperature equal to or higher than the glass transition temperature of the microlens pattern, for example, by heat-treating at 130 to 160 ° C. for about 2 to 15 minutes to fluidize the microlens pattern and make a convex microlens. Can be formed.

From the viewpoint of low-temperature curing suitable for the case of using an organic photodiode or the like, the crosslinking by heating in the curing step is preferably performed at a temperature of 200 ° C. or lower, more preferably 100 ° C. or higher and 180 ° C. or lower, 110. It is more preferably ° C. or higher and 150 ° C. or lower, and particularly preferably 120 ° C. or higher and 150 ° C. or lower.

<CMOS image sensor>
The CMOS image sensor according to the sixth aspect includes a cured product according to the third aspect.
A solid-state image sensor including the CMOS image sensor according to the sixth aspect can be formed.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to these Examples.

<Preparation of energy-sensitive composition>
The following components were uniformly mixed in the amounts shown in Tables 1 and 2 to prepare energy-sensitive compositions of Examples and Comparative Examples.
The unit of numerical values in Tables 1 and 2 is the mass part.

(resin)
As the resin 1, a copolymer of styrene, p-hydroxyphenyl methacrylate and glycidyl methacrylate (styrene / p-hydroxyphenyl methacrylate / glycidyl methacrylate = 45:10:45 (molar ratio); weight average molecular weight 50,000) was used.
As the resin 2, a copolymer of styrene and glycidyl methacrylate (styrene / glycidyl methacrylate = 50: 50 (molar ratio); weight average molecular weight 50,000) was used.
As the resin 3, a copolymer of p-hydroxyphenyl methacrylate and glycidyl methacrylate (p-hydroxyphenyl methacrylate / glycidyl methacrylate = 40: 60 (molar ratio); weight average molecular weight 9000) was used.
As the resin 4, a copolymer of p-hydroxyphenyl methacrylate and glycidyl methacrylate (p-hydroxyphenyl methacrylate / glycidyl methacrylate = 40: 60 (molar ratio); weight average molecular weight of 5000) was used.

（熱酸発生剤の酸発生温度の測定）
各熱酸発生剤５ｍｇに対し、開始温度３０℃、測定温度範囲３０〜３００℃、昇温速度１０℃／分の条件下で、示差走査熱量計（Ｑ２０００；ＴＡインスツルメント社製）を用いて示差走査熱量測定を行った。得られたＤＳＣ曲線から、最大吸熱ピークのピーク温度（℃）を算出し、各熱酸発生剤の酸発生温度とした。結果を以下に示す。
熱酸発生剤１の酸発生温度：１３０．７℃
熱酸発生剤２の酸発生温度：１４０．３℃ (Thermal acid generator)
The following thermal acid generators 1 and 2 were used as the thermal acid generators. In the formula below, Tf represents a trifluoromethanesulfonyl group.

(Measurement of acid generation temperature of thermal acid generator)
For each 5 mg of thermoacid generator, a differential scanning calorimeter (Q2000; manufactured by TA Instruments) was used under the conditions of a starting temperature of 30 ° C., a measurement temperature range of 30 to 300 ° C., and a heating rate of 10 ° C./min. The differential scanning calorimetry was performed. From the obtained DSC curve, the peak temperature (° C.) of the maximum endothermic peak was calculated and used as the acid generation temperature of each thermoacid generator. The results are shown below.
Acid generation temperature of thermal acid generator 1: 130.7 ° C
Acid generation temperature of thermal acid generator 2: 140.3 ° C

(Other ingredients)
As the surfactant, PF-656 (manufactured by Omniova) was used.
As the photosensitizer, an esterified product of the following phenol compound with 1,2-naphthoquinonediazide-5-sulfonyl chloride was used.

（溶剤）
溶剤１としてプロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）を使用し、溶剤２としてＰＧＭＥＡと乳酸エチルとの混合溶剤（ＰＧＭＥＡ：乳酸エチル＝１：１（体積比））を使用した。

(solvent)
Propylene glycol monomethyl ether acetate (PGMEA) was used as the solvent 1, and a mixed solvent of PGMEA and ethyl lactate (PGMEA: ethyl lactate = 1: 1 (volume ratio)) was used as the solvent 2.

<Test>
(Curing test)
The energy-sensitive compositions of each Example and Comparative Example were applied by spin coating on a green color filter formed on a substrate, dried using a hot plate at 90 ° C. for 90 seconds under prebaking conditions, and had a film thickness of 1 μm. A resin layer was formed. Then, it was heated and cured using a hot plate under the condition of 150 ° C. for 5 minutes.
The obtained cured film was subjected to a test of immersing it in acetone under room temperature (23 ° C.) conditions for 5 minutes.

The change in film thickness before and after immersion in acetone was measured, and the film thickness of 95% or more was evaluated as “◯” and the film thickness of less than 95% was evaluated as “x” with respect to the film thickness before immersion in acetone. The results are shown in Table 1.

As is clear from the results shown in Table 1, Comparative Example 1 containing no thermoacid generator and the resin containing hydroxyl groups (meth) acrylic acid under low temperature curing conditions of 150 ° C. on a green color filter that can be in an amine environment. In Comparative Example 2 which does not have the structural unit (a1) derived from the derivative, the result was inferior in curability.
On the other hand, even under low temperature curing conditions of 150 ° C. on a green color filter that can be in an amine environment, the resin has a structural unit (a1) derived from a hydroxyl group-containing (meth) acrylate (hydroxyl-containing (meth) acrylic acid derivative). In Examples 1 and 2 in which a thermal acid generator having a specific acid generation temperature was used, the results were excellent in curability.

(Surface hardness test)
The energy-sensitive compositions of each Example and Comparative Example were applied to a glass substrate by spin coating and dried using a hot plate at 90 ° C. for 90 seconds to form a resin layer having a film thickness of 1 μm. The obtained resin layer was irradiated with UV (exposure amount 200 mJ / cm ² ), and then heated and cured using a hot plate under the condition of 130 ° C. for 1 hour. The hardness of the obtained cured film was measured according to JIS K 5600-5-4. The results are shown in Table 2. The pencil hardness here is preferably 3H or higher and 4H or higher.

(Crosslink rate)
The energy-sensitive compositions of each Example and Comparative Example were applied to a silicon substrate by spin coating and dried using a hot plate at 90 ° C. for 90 seconds to form a resin layer having a film thickness of 1 μm. The obtained resin layer was irradiated with UV (exposure amount 200 mJ / cm ² ), and then heated and cured using a hot plate under the condition of 150 ° C. for 1 hour.
The cross-linking rate of the resin film before and after curing was measured from the degree of decrease in the peak area around 900 cm- ¹ derived from the epoxy group using a Fourier transform infrared spectrophotometer (FT-IR) (Nicolet 6700, manufactured by Thermo). The results are shown in Table 2. The cross-linking rate here is 70% or more, preferably 80% or more, and more preferably 90% or more.

As is clear from the results shown in Table 2, at low temperature curing at 150 ° C. or lower, in Comparative Example 3 containing no thermoacid generator, the cross-linking rate of the cured film was low, the surface hardness was low, and the curability was inferior. It was.
On the other hand, the resin has a structural unit (a1) derived from a hydroxyl group-containing (meth) acrylate (hydroxyl-containing (meth) acrylic acid derivative) even when cured at a low temperature of 150 ° C. or lower, and has a (C) acid crosslinkable structure. In Examples 3 and 4 in which a thermal acid generator containing a specific acid generation temperature was used, the crosslink rate was high, the surface hardness was high, and the curability was excellent.

Claims (14)

An energy-sensitive composition used to form a flattening film or microlens on a substrate comprising an organic photodiode .
The energy-sensitive composition contains (A) a resin and (B) a thermoacid generator.
The resin (A) has a structural unit (a1) derived from a hydroxyl group-containing (meth) acrylic acid derivative and has a structural unit (a1).
The acid generation temperature of the thermal acid generator (B) observed in the differential scanning calorimetry is 100 ° C. or higher and 200 ° C. or lower.
The energy sensitive composition further comprises (C) an acid crosslinkable structure.
The (C) acid crosslinkable structure is a partial structure of the (C1) polymer or the (C2) monomer.
The energy-sensitive composition, wherein the (C1) polymer may be the (A) resin. The energy-sensitive composition according to claim 1, wherein the (C) acid-crosslinkable structure is at least one group selected from the group consisting of an oxylanyl group, an oxetanyl group, an alicyclic epoxy group and an alkoxymethyl group. The (C) acid crosslinkable structure is a partial structure of the (A) resin.
The energy-sensitive composition according to claim 1 or 2, wherein the resin (A) contains a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2).

(In the above formulas (1) and (2), R ₀ independently represents a hydrogen atom or a methyl group, X represents an oxygen atom (-O-) or an -NH- group, and Y represents a single bond or an alkylene group. Represents a group, R ₁ represents an alkyl group, R ₂ represents a monovalent organic group having acid crosslinkability. A represents an integer of 1 to 5, b represents an integer of 0 to 4, and a + b represents 5. It is as follows.) The energy-sensitive composition according to claim 3, wherein the content of the structural unit represented by the formula (2) is 45 to 80 mol% with respect to the total structural unit in the resin (A). The energy-sensitive composition according to any one of claims 1 to 4 , wherein the resin (A) further has a structural unit (a2) represented by the following formula (3).

(In the above formula (3), R ₀ represents a hydrogen atom or a methyl group, and R ₃ is a group independently selected from the group consisting of a hydrogen atom, an alkyl group and an aryl group.) The energy-sensitive composition according to claim 5, wherein the content of the structural unit (a2) represented by the formula (3) is 30 to 60 mol% with respect to all the structural units in the resin (A). .. The energy-sensitive composition according to any one of claims 1 to 6 , wherein the thermal acid generator (B) is a compound represented by the following formula (4).

(In the above formula (4), R ₄ is an independent hydrogen atom or an organic group, and X ⁻ is a halide ion, a hydroxide ion, a nitrate ion, a borate, an organic carboxylic acid ion, and an organic sulfonic acid ion. It is a kind selected from the group consisting of.) The energy-sensitive composition according to any one of claims 1 to 7 , further comprising a photosensitizer. A resin layer forming step of forming a resin layer by applying the energy-sensitive composition according to any one of claims 1 to 8 onto a base material provided with an organic photodiode .
A method for producing a cured product, which comprises a heating step of heating the resin layer. The method for producing a cured product according to claim 9 , wherein the heating temperature in the heating step is 200 ° C. or lower. A lens material layer formed by applying the energy-sensitive composition according to any one of claims 1 to 7 onto a substrate provided with an organic photodiode and cross-linking the resin layer obtained by heating to form a lens material layer. The formation process and
A lens pattern forming step of forming a resist pattern on the lens material layer and then reflowing the resist pattern by heating to form a lens pattern.
A method for manufacturing a microlens, which comprises a shape transfer step of dry-etching the lens material layer and the lens pattern using the lens pattern as a mask to transfer the shape of the lens pattern to the lens material layer. The energy-sensitive composition according to claim 8 is applied on a substrate including at least a solid-state image sensor including an organic photodiode and a color filter formed corresponding to the solid-state image sensor to form a resin layer. The resin layer forming process to be formed and
A microlens pattern forming step of forming a microlens pattern corresponding to the solid-state image sensor and the color filter by pattern-exposing and developing the resin layer.
A bleaching process in which the entire surface of the microlens pattern is exposed and bleached,
A thermal flow step of heating the bleached microlens pattern to cause a thermal flow,
A method for manufacturing a microlens, which comprises a curing step of forming a microlens by cross-linking the thermally flowed microlens pattern by heating. The method for producing a microlens according to claim 11 or 12 , wherein the cross-linking by heating is performed at a temperature of 200 ° C. or lower. A base material including an organic photodiode and a flattening film or microlens provided on the base material and composed of a cured product of the energy-sensitive composition according to any one of claims 1 to 8. CMOS image sensor.