KR20200079414A - Resin composition, and method of manufacturing substrate including microlens pattern - Google Patents

Abstract

The present invention relates to a resin composition, which is used for forming a dot pattern when forming a microlens pattern by heating the dot pattern including a square dot and a lattice-shaped space to thermally flow the dot pattern, and also, is able to form the dot pattern which can properly thermally flow even at low temperatures, and to a method for manufacturing a substrate having a microlens pattern using the resin composition. According to the resin composition of the present invention, which is used for forming a dot pattern when forming a microlens pattern by heating the dot pattern including a square dot and a lattice-shaped space to thermally flow the dot pattern, a glass transition temperature Tg measured under predetermined conditions of a resin film formed by using the resin composition is 70°C or less.

Description

RESIN COMPOSITION, AND METHOD OF MANUFACTURING SUBSTRATE INCLUDING MICROLENS PATTERN}

The present invention relates to a resin composition and a method for producing a microlens pattern using the resin composition.

BACKGROUND ART A solid-state imaging device is mounted on a digital camera, a mobile phone with a camera, and the like, which are widely spread nowadays. Typical solid-state imaging devices include charge coupled device (CCD) image sensors and complementary metal-oxide semiconductor (CMOS) image sensors. In these image sensors, fine lenses (hereinafter referred to as microlenses) are formed for the purpose of improving sensitivity. In the manufacture of the image sensor, in addition to the microlens, other parts such as a color filter are formed as necessary.

In recent years, miniaturization of a solid-state imaging device, an increase in the number of imaging pixels, and the like have progressed, and various research and development have been made to further improve light collection efficiency. For example, in Patent Literature 1, a resist film is applied onto a planarization layer formed on a light-receiving portion of a solid-state imaging element, a photomask is interposed to expose the resist film, and then the exposed resist film is developed to make the resist film into a lens shape A patterning method has been proposed.

In the method described in Patent Document 1, the resist film is exposed using a photomask in which a light-transmitting portion made of a medium of a light refractometer having a stepped portion is formed on a surface portion.

Japanese Patent Publication No. 2003-98649

On the other hand, after forming the bulb pattern of the microlens pattern which consists of a resin composition, the microlens pattern can also be formed by heat-flowing the said bulb pattern by heat processing.

In the method described in Patent Document 1, it is necessary to use a photomask having a precisely designed shape. Such a photomask is expensive and difficult to manufacture. However, it is not necessary to use the photomask as described in patent document 1 in the method by the said heat flow.

Regarding the above-mentioned method for manufacturing a microlens pattern by heat flow, from the viewpoint of reducing the heat resistance of the material used for the solid-state imaging element and the manufacturing energy of the microlens pattern, even if the heating temperature is lowered, the pattern that heat flows satisfactorily There is a need for a resin composition that can be formed.

This invention is made|formed in view of the said subject, When forming a microlens pattern by heating the dot pattern which consists of a square dot and a lattice-like space, and making a dot pattern thermally flow, it is used for formation of a dot pattern. An object of the present invention is to provide a resin composition capable of forming a dot pattern capable of being heat-flowed well even at low temperatures and a method for manufacturing a substrate having a microlens pattern using the resin composition.

When the present inventors form a microlens pattern by heating a dot pattern consisting of a square dot and a lattice-like space to thermally flow the dot pattern, the resin composition used for the formation of the dot pattern is the resin. It has been found that the above-described problems can be solved by setting the glass transition temperature Tg measured under predetermined conditions of the resin film formed using the composition to 70° C. or less, and the present invention has been completed. More specifically, the present invention provides the following.

In the first aspect of the present invention, in a method for forming a microlens pattern by heating a dot pattern composed of a rectangular dot and a lattice-like space to thermally flow the dot pattern, the resin used for the formation of the dot pattern As a composition,

The resin composition contains the resin (A),

Of the resin film formed using the resin composition, the following 1) to 4):

1) Process of spin coating a resin composition on a substrate to form a coating film,

2) Process of heating the coating film at 100° C. for 90 seconds to form a resin film,

3) a step of taking a sample for measuring a glass transition point from the obtained resin film, and performing a measurement by a differential scanning calorimeter (DSC) using the obtained sample to obtain a reverse heat flow curve, and

4) A step of determining the value of the glass transition temperature Tg by reading the minimum value in the differential curve derived by first differentiating the obtained reverse heat flow curve with temperature as the glass transition temperature Tg,

The resin composition whose glass transition temperature Tg measured according to the method which consists of the process of 70 degreeC or less is 70 degrees C or less.

The 2nd aspect of this invention is the process of forming the dot pattern which consists of square dots and a lattice-shaped space on a board|substrate using the resin composition which concerns on 1st aspect,

It is a manufacturing method of the board|substrate which has a microlens pattern including the heat flow process which heat-flows a dot pattern by heating.

According to the present invention, when forming a microlens pattern by heating a dot pattern consisting of a square dot and a lattice-like space to thermally flow the dot pattern, it is used for forming a dot pattern and heats well even at low temperatures. It is possible to provide a method for manufacturing a substrate comprising a resin composition capable of forming a flowable dot pattern and a microlens pattern using the resin composition.

1 is a view schematically showing a method of manufacturing a substrate having a microlens pattern.

≪Resin composition≫

The resin composition is used for forming a dot pattern in a method of forming a microlens pattern by heating a dot pattern composed of square dots and a lattice-like space to heat-flow a dot pattern.

Here, the microlens pattern is a pattern composed of two or more microlenses, each disposed at a predetermined position.

The resin composition contains resin (A).

Moreover, the following 1)-4) of the resin film formed using a resin composition:

1) Process of spin coating a resin composition on a substrate to form a coating film,

2) Process of heating the coating film at 100° C. for 90 seconds to form a resin film,

3) a step of taking a sample for measuring a glass transition point from the obtained resin film, and performing a measurement by a differential scanning calorimeter (DSC) using the obtained sample to obtain a reverse heat flow curve, and

4) A step of determining the value of the glass transition temperature Tg by reading the minimum value in the differential curve derived by first differentiating the obtained reverse heat flow curve with temperature as the glass transition temperature Tg,

The glass transition temperature Tg measured according to the method comprising the steps of is 70° C. or less. The value of Tg is more preferably 68°C or lower, and particularly preferably 66°C or lower.

Moreover, the lower limit of Tg is preferably 40°C or higher, more preferably 50°C or higher, and even more preferably 55°C or higher.

When the resin composition has the above-mentioned thermal properties, good heat flow at a low temperature for the dot pattern formed using the resin composition is realized.

Tg measured by the above method can be adjusted, for example, by appropriately changing the chemical structure of the structural unit constituting the resin (A). Moreover, when resin (A) contains 2 or more types of structural unit, Tg measured by the said method can be adjusted by changing the ratio of a structural unit. Moreover, when a resin composition contains a photosensitive agent (B) as mentioned later, Tg measured by the said method can be adjusted by changing the kind and content of the photosensitive agent (B) contained in a resin composition.

The method for forming the dot pattern is not particularly limited. For example, the dot pattern may be formed by a printing method such as an inkjet printing method. The dot pattern may be formed by a photolithography method including patterning by exposure and development.

The resin composition is preferably a photosensitive resin composition capable of forming a dot pattern by a photolithography method, since it is easy to form a fine and fine dot pattern.

For the dot pattern formed using the resin composition, the width of the space is preferably 0.2 µm or more and 2.0 µm or less, and more preferably 0.25 µm or more and 1.0 µm or less.

In addition, when the width of the space is set to W and the height of the dot is set to H, the aspect ratio expressed in H/W is preferably 1.0 or more and 10.0 or less, and more preferably 2.0 or more and 8.0 or less.

The height H of the dot is not particularly limited, but is preferably 0.25 μm or more and 4.0 μm or less, and more preferably 0.5 μm or more and 2.0 μm or less.

Further, the dot pattern is formed on the substrate. Each dot constituting the dot pattern is usually a cuboid shape, a cube shape, or a shape similar to these shapes, and the dimension in the thickness direction and the same direction of the substrate with respect to the dot is the height H of the dot.

Moreover, the shape of a square surface in the same direction or substantially the same direction as the plane direction of the substrate with respect to the dot is a square, a rectangle, or a shape similar to these shapes. The length of each of the four sides is preferably 0.5 µm or more and 5 µm or less, and more preferably 1 µm or more and 4 µm or less, with respect to the surface of the substrate relative to the dot and the square surface in the same or approximately the same direction.

For the dot pattern formed using the resin composition, if the width of the space and the aspect ratio are within the above range, it is easy to obtain a microphone lens pattern of a desired shape after heat flow.

The temperature of the heat flow for the dot pattern formed using the resin composition is preferably (Tg + 5) °C or higher and 130 °C or lower, and more preferably (Tg + 5) °C or higher and 100 °C or lower.

When the dot pattern formed using the resin composition is heat-flowed at a temperature within this range, it is easy to heat-flow the dot pattern to a desired degree while suppressing excessive heat flow of the dot pattern.

As a preferable resin composition, the photosensitive resin composition containing alkali-soluble resin (A1) as resin (A) and a photosensitive agent (B) is mentioned. Hereinafter, essential or arbitrary components contained in such a preferred photosensitive resin composition will be described.

<Alkali-soluble resin (A1)>

The alkali-soluble resin (A1) is a resin having an alkali-soluble group such as a carboxyl group or a phenolic hydroxyl group, and is not particularly limited as long as it is a resin soluble in a basic solution.

For example, examples of the alkali-soluble resin (A1) include a phenol resin, an acrylic resin, a copolymer of styrene and acrylic acid, a polymer or copolymer of hydroxystyrene, and polyvinylphenol, polyα-methylvinylphenol, and the like. .

The alkali-soluble resin (A1) has the following formula (a1):

[Formula 1]

(In formula (a1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a single bond or an alkylene group having 1 to 5 carbon atoms, and R ³ has 1 to 5 carbon atoms. The following alkyl group, a represents an integer of 1 or more and 5 or less, b represents an integer of 0 or more and 4 or less, a+b is 5 or less, and when b is 2 or more, a plurality of R ^{3 s} It may be the same or different)

It is preferable to contain the (meth)acrylic-type resin containing the structural unit represented by.

When a (meth)acrylic-type resin contains the structural unit represented by said formula (a1), it is easy to obtain favorable patterning characteristics at the time of forming a dot pattern using a photosensitive resin composition.

In the formula (a1), when R ² is an alkylene group having 1 to 5 carbon atoms, the alkylene group may be linear or branched. Specific examples of the alkylene group as R ² are methylene group, ethane-1,2-diyl group, ethane-1,1-diyl group, propane-1,3-diyl group, propane-1,2-diyl group, Propane-1,1-diyl group, propane-2,2-diyl group, butane-1,4-diyl group, butane-1,3-diyl group, butane-1,2-diyl group, butane-1,1 -Diyl group, butane-2,3-diyl group, butane-2,2-diyl group, pentane-1,5-diyl group, pentane-1,4-diyl group, pentane-1,3-diyl group, pentane -1,2-diyl group, pentane-1,1-diyl group, pentane-2,4-diyl group, pentane-2,3-diyl group, pentane-2,2-diyl group, and pentane-3,3 -Di-diary.

As R ² described above, it is easy to obtain or synthesize a compound that gives the structural unit represented by formula (a1), and from the viewpoint of easy to form a dot pattern that flows favorably at a low temperature using a resin composition. A bond, a methylene group, and an ethane-1,2-diyl group are preferable, a single bond, and a methylene group are more preferable, and a single bond is particularly preferable.

In the formula (a1), R ³ is an alkylene group having 1 to 5 carbon atoms. The alkylene group as R ³ may be linear or branched. Specific examples of the alkylene group as R ³ are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, and isophene Til group, neopentyl group, sec-pentyl group, tert-pentyl group, and pentane-3-yl group.

In Formula (a1), a, which is the number of hydroxyl groups on the benzene ring, is an integer of 1 or more and 5 or less. As a, point 1 or 2 is preferable and 1 is more preferable at the point which is easy to obtain or synthesize|combine the compound which gives the structural unit represented by Formula (a1).

In formula (a1), it is preferable that at least one of the one or more hydroxyl groups is bonded to the para position relative to the position where the group represented by -CO-OR ² -is bonded on the benzene ring.

As a structural unit represented by Formula (a1), a structural unit represented by the following Formula (a1-1) or the following Formula (a1-2) is preferable, for example. In formulas (a1-1) and (a1-2), R ¹ is a hydrogen atom or a methyl group.

[Formula 2]

In the (meth)acrylic resin containing the structural unit represented by formula (a1), the content of the structural unit represented by formula (a1) is preferably 20% by mass or more and 80% by mass or less, and 20% by mass or more and 70% by mass The following are more preferable, 20 mass% or more and 60 mass% or less are more preferable, and 20 mass% or more and 50 mass% or less are particularly preferable.

It is also preferable that the lower limit of the content of the structural unit represented by the formula (a1) in the (meth)acrylic resin containing the structural unit represented by the formula (a1) is 25% by mass or more, or 30% by mass or more.

When the content of the structural unit represented by Formula (a1) in the (meth)acrylic resin containing the structural unit represented by Formula (a1) is within the above range, when forming a dot pattern using a photosensitive resin composition It is easy to achieve good patterning characteristics and the good low-temperature heat flow property of a dot pattern.

The (meth)acrylic resin containing the structural unit represented by the formula (a1) is derived from an alkyl ester having 1 to 10 carbon atoms or more of the (meth)acrylic acid together with the structural unit represented by the formula (a1). It is preferable to contain the said structural unit.

In this case, using a photosensitive resin composition, it is particularly easy to form a dot pattern excellent in low-temperature heat flow properties.

As the alkyl ester having 1 to 10 carbon atoms in (meth)acrylic acid, alkyl esters having 2 to 6 carbon atoms in (meth)acrylic acid are preferred, and 3 to 5 carbon atoms in (meth)acrylic acid Alkyl ester is more preferable.

The alkyl group constituting the alkyl ester may be linear or branched, and a linear chain is preferred.

Preferable specific examples of the alkyl ester of (meth)acrylic acid include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, ( Isobutyl meth)acrylate, sec-butyl acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl acrylate, n-octyl (meth)acrylate, n-octyl (meth)acrylic acid 2-ethylhexyl, (meth)acrylic acid n-nonyl, and (meth)acrylic acid n-decyl.

Of these, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, and n-hexyl (meth)acrylate are preferred. Do.

In the (meth)acrylic resin containing a structural unit represented by formula (a1), the content of the structural unit derived from an alkyl ester having 1 to 10 carbon atoms in (meth)acrylic acid is 10% by mass or more and 80% by mass The following are preferable, 15 mass% or more and 80 mass% or less are more preferable, and 20 mass% or more and 80 mass% or less are more preferable.

(Meth)acrylic-type resin containing the structural unit represented by Formula (a1) is 1 to 10 carbon atoms of the structural unit represented by Formula (a1) and (meth)acrylic acid within the range which does not impair the object of the present invention. You may contain other structural units other than the structural unit derived from the following alkyl ester.

Examples of the monomer conferring these other structural units include (meth)acrylic acid esters having no epoxy group, unsaturated compounds having an epoxy group, and (meth)acrylic groups other than alkyl esters having 1 to 10 carbon atoms in (meth)acrylic acid. And amides, allyl compounds, vinyl ethers, vinyl esters, and styrenes. These compounds can be used alone or in combination of two or more.

Examples of (meth)acrylic acid esters that do not have an epoxy group include chloroethyl (meth)acrylate, 2,2-dimethylhydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and trimethylolpropane mono. (Meth)acrylate, benzyl (meth)acrylate, and furfuryl (meth)acrylate.

Examples of the unsaturated compound having an epoxy group include glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, and 6,7-epoxyheptyl (meth). (Meth)acrylic acid epoxy alkyl esters such as acrylates; α-alkyl acrylic acid epoxyalkyl esters such as α-ethyl acrylate glycidyl, α-n-propyl acrylate glycidyl, α-n-butyl acrylate glycidyl, and α-ethyl acrylic acid 6,7-epoxyheptyl; And the like.

As the unsaturated compound having an epoxy group, (meth)acrylic acid ester having an alicyclic group containing an epoxy group is also preferable.

Examples of (meth)acrylamides include (meth)acrylamide, N-alkyl(meth)acrylamide, N-aryl(meth)acrylamide, N,N-dialkyl(meth)acrylamide, and N,N-aryl (Meth)acrylamide, N-methyl-N-phenyl (meth)acrylamide, N-hydroxyethyl-N-methyl (meth)acrylamide, and the like.

Examples of the allyl compound include allyl esters such as allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, and allyl lactate; Allyloxyethanol; And the like.

As vinyl ethers, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethyl hexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chlorethyl vinyl ether, 1-methyl-2,2-dimethylpropyl Vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl Alkyl vinyl ethers such as ether; Vinyl aryl ethers such as vinyl phenyl ether, vinyl tolyl ether, vinyl chlorphenyl ether, vinyl-2,4-dichlorphenyl ether, vinyl naphthyl ether, and vinyl anthranyl ether; And the like.

Vinyl esters include vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valate, vinyl caproate, vinyl chlor acetate, vinyl dichlor acetate, vinyl methoxy acetate, vinyl butoxy acetate, vinyl And phenyl acetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinyl benzoate, vinyl salicylate, vinyl chlorbenzoate, vinyl tetrachlorbenzoate, and vinyl naphthoate.

As styrenes, Styrene; Methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, decylstyrene, benzylstyrene, chlormethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene , Alkyl styrenes such as acetoxy methyl styrene; Alkoxystyrenes such as methoxystyrene, 4-methoxy-3-methylstyrene and dimethoxystyrene; Chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodinestyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethyl Halostyrenes such as styrene and 4-fluoro-3-trifluoromethylstyrene; And the like.

The amount of other structural units in the (meth)acrylic resin containing the structural unit represented by formula (a1) is not limited within the range of not impairing the object of the present invention from the mass of the (meth)acrylic resin, The remaining amount may be subtracted from the mass of the structural unit represented by the formula (a1) and the mass of the structural unit derived from an alkyl ester having 1 to 10 carbon atoms in (meth)acrylic acid.

The content of the (meth)acrylic resin containing the structural unit represented by the formula (a1) in the alkali-soluble resin (A1) is preferably 70 mass% or more, more preferably 80 mass% or more, and more preferably 90 mass% or more. This is more preferable, and particularly preferably 100% by mass.

The molecular weight of the alkali-soluble resin (A1) is not particularly limited, but as a mass average molecular weight (Mw: measured value in terms of styrene in gel permeation chromatography (GPC)), 1000 or more and 20000 or less are preferable, 1500 or more and 15000 or less Is more preferable, and 2000 or more and 10,000 or less are even more preferable.

<Photosensitive agent (B)>

The photosensitive agent (B) increases the solubility of the photosensitive resin composition in the alkali developer by exposure. It is preferable that the photosensitive agent (B) is a quinonediazide group containing compound.

Examples of the quinonediazide group-containing compound include a complete esterified product or a partial esterified product of a phenol compound and a naphthoquinonediazide sulfonic acid compound. Examples of the phenol compound include polyhydroxybenzophenone compounds such as 2,3,4-trihydroxybenzophenone and 2,3,4,4'-tetrahydroxybenzophenone; Tris(4-hydroxyphenyl)methane, bis(4-hydroxy-3-methylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,3,5-trimethylphenyl)-2-hydroxy Phenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-4-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-3-hydroxyphenylmethane, bis(4 -Hydroxy-3,5-dimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-4-hydroxyphenylmethane, bis(4-hydroxy-2, 5-dimethylphenyl)-3-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)- 3,4-dihydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-3,4-dihydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)- 2,4-dihydroxyphenylmethane, bis(4-hydroxyphenyl)-3-methoxy-4-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-4- Hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-2-hydroxy Trisphenol type compounds such as phenylmethane and bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3,4-dihydroxyphenylmethane; 2,4-bis(3,5-dimethyl-4-hydroxybenzyl)-5-hydroxyphenol, 2,6-bis(2,5-dimethyl-4-hydroxybenzyl)-4-methylphenol, etc. Linear trinuclear phenol compounds; 1,1-bis[3-(2-hydroxy-5-methylbenzyl)-4-hydroxy-5-cyclohexylphenyl]isopropane, bis[2,5-dimethyl-3-(4-hydroxy- 5-methylbenzyl)-4-hydroxyphenyl]methane, bis[2,5-dimethyl-3-(4-hydroxybenzyl)-4-hydroxyphenyl]methane, bis[3-(3,5-dimethyl -4-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane, bis[3-(3,5-dimethyl-4-hydroxybenzyl)-4-hydroxy-5-ethylphenyl]methane, bis [3-(3,5-diethyl-4-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane, bis[3-(3,5-diethyl-4-hydroxybenzyl)-4- Hydroxy-5-ethylphenyl]methane, bis[2-hydroxy-3-(3,5-dimethyl-4-hydroxybenzyl)-5-methylphenyl]methane, bis[2-hydroxy-3-(2 -Hydroxy-5-methylbenzyl)-5-methylphenyl]methane, bis[4-hydroxy-3-(2-hydroxy-5-methylbenzyl)-5-methylphenyl]methane, bis[2,5-dimethyl Linear type 4 nucleus phenol compounds such as -3-(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl]methane; 2,4-bis[2-hydroxy-3-(4-hydroxybenzyl)-5-methylbenzyl]-6-cyclohexylphenol, 2,4-bis[4-hydroxy-3-(4-hydroxy Hydroxybenzyl)-5-methylbenzyl]-6-cyclohexylphenol, 2,6-bis[2,5-dimethyl-3-(2-hydroxy-5-methylbenzyl)-4-hydroxybenzyl]-4 -Linear polyphenol compounds, such as a linear 5 nucleus phenol compound, such as methylphenol; Bis(2,3,4-trihydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)methane, 2,3,4-trihydroxyphenyl-4'-hydroxyphenylmethane, 2-( 2,3,4-trihydroxyphenyl)-2-(2',3',4'-trihydroxyphenyl)propane, 2-(2,4-dihydroxyphenyl)-2-(2', 4'-dihydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(4'-hydroxyphenyl)propane, 2-(3-fluoro-4-hydroxyphenyl)-2-( 3'-fluoro-4'-hydroxyphenyl)propane, 2-(2,4-dihydroxyphenyl)-2-(4'-hydroxyphenyl)propane, 2-(2,3,4-tri Hydroxyphenyl)-2-(4'-hydroxyphenyl)propane, 2-(2,3,4-trihydroxyphenyl)-2-(4'-hydroxy-3',5'-dimethylphenyl) Bisphenol-type compounds such as propane; 1-[1-(4-hydroxyphenyl)isopropyl]-4-[1,1-bis(4-hydroxyphenyl)ethyl]benzene, 1-[1-(3-methyl-4-hydroxyphenyl )Isopropyl]-4-[1,1-bis(3-methyl-4-hydroxyphenyl)ethyl]benzene, and other polynuclear branched compounds; And condensed phenol compounds such as 1,1-bis(4-hydroxyphenyl)cyclohexane. These may be used alone or in combination of two or more.

In addition, examples of the naphthoquinone diazide sulfonic acid compound include naphthoquinone-1,2-diazide-5-sulfonic acid chloride or naphthoquinone-1,2-diazide-4-sulfonic acid chloride.

In addition, other quinonediazide group-containing compounds, such as orthobenzoquinonediazides, orthonaphthoquinonediazides, orthoanthraquinonediazides, orthonaphthoquinonediazidesulfonic acid esters and the like, these nuclear-substituted derivatives, furthermore Orthoquinone diazide sulfonyl chloride and compounds having hydroxyl or amino groups, such as phenol, p-methoxyphenol, dimethylphenol, hydroquinone, bisphenol A, naphthol, pyrocatechol, pyrogallol, pyrogallol monomethyl ether, Pyrogalol-1,3-dimethyl ether, gallic acid, a reaction product such as esterified or etherified gallic acid, aniline, p-aminodiphenylamine, etc. may also be used by leaving some hydroxyl groups. These may be used alone, or two or more of them may be used in combination.

These quinonediazide group-containing compounds include, for example, the phenol compounds described above and naphthoquinone-1,2-diazide-5-sulfonic acid chloride or naphthoquinone-1,2-diazide-4-sulfonic acid chloride. In a suitable solvent such as dioxane, it can be produced by condensation in the presence of an alkali such as triethanolamine, alkali carbonate, or alkali hydrogen carbonate, followed by complete esterification or partial esterification.

The amount of the photosensitive agent (B) used is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less, relative to the mass of the resin (A). The lower limit of the amount of the photosensitive agent (B) used is, for example, 10 mass% or more, more preferably 15 mass% or more, and even more preferably 20 mass% or less, relative to the mass of the resin (A).

By using the photosensitive agent (B) in an amount in this range, it is easy to prepare a resin composition in which the above Tg is an appropriate value. As a result, good patterning characteristics when forming a dot pattern using a photosensitive resin composition, and good low-temperature heat flow property of a dot pattern are easily compatible.

(Other ingredients)

The photosensitive resin composition containing the alkali-soluble resin (A1) as the resin (A) and the photosensitive agent (B) may contain components other than the alkali-soluble resin (A1) and the photosensitive agent (B) as necessary.

As another component, an organic solvent and a heat crosslinking agent are mentioned, for example.

When the photosensitive resin composition contains a heat crosslinking agent, the heat resistance of the formed microlens can be improved, and it is easy to suppress excessive heat flow of the dot pattern.

There is no restriction|limiting in particular as a heat crosslinking agent, For example, the thing similar to a well-known crosslinking agent can be used selecting it suitably. For example, melamine resin, urea resin, guanamine resin, glycoluril-formaldehyde resin, succinylamide-formaldehyde resin, ethyleneurea-formaldehyde resin, and the like are used.

In particular, alkoxymethylated amino resins such as alkoxymethylated melamine resins and alkoxymethylated urea resins can be preferably used.

Among them, preferred examples of the heat crosslinking agent include methoxymethylated melamine resin, propoxymethylated melamine resin, butoxymethylated melamine resin, methoxymethylated urea resin, ethoxymethylated urea resin, propoxymethylated urea resin, and parts And ethoxymethylated urea resins.

A resin composition is prepared by uniformly mixing the components described above.

≪Method for manufacturing a substrate having a microlens pattern≫

A substrate having a microlens pattern is manufactured using the resin composition described above.

Specifically, a method of manufacturing a substrate having a microlens pattern,

A step of forming a dot pattern consisting of square dots and lattice-like spaces on a substrate using the resin composition described above,

And a heat flow step in which the dot pattern is heat flowed by heating.

Moreover, preferable ranges, such as the shape and dimension of a dot pattern, the width of the space in a dot pattern, and the aspect ratio H/W value when the height of a dot is set to H, are the same as described above for the resin composition. .

The substrate is not particularly limited as long as it is a substrate conventionally used as a target for forming microlens patterns.

Examples of preferred substrates include substrates on which a solid-state imaging element, a first planarizing film, a color filter, and a second planarizing film are formed on a silicon substrate.

In such a substrate, a first planarization film having a flat surface is formed so as to cover a solid-state imaging element located at a predetermined position on the silicon substrate. On the first planarizing film, color filters are formed at positions above the positions of the respective solid-state imaging elements. Then, a second flattening film having a flat surface is formed so as to cover the color filter.

In addition, in the substrate, the direction from the silicon substrate to the second planarization film side is upward, and the direction from the second planarization film to the silicon substrate side is downward.

Hereinafter, a method of forming a microlens pattern on a substrate will be described with reference to FIG. 1.

<Step of forming dot pattern>

1(b), in order to form a microlens pattern on the substrate 10, first, a dot pattern 12 is formed on the substrate 10 using the above resin composition.

The method for forming the dot pattern 12 is not particularly limited.

For example, as described above, the dot pattern 12 may be formed by a printing method such as an inkjet printing method. The dot pattern 12 may be formed by a photolithography method including patterning by exposure and development.

The detailed prescription of the photolithography method is appropriately selected depending on the kind of component contained in the resin composition or the composition of the resin composition.

For example, when a positive photosensitive resin composition containing an alkali-soluble resin (A1) and a photosensitive agent (B), which are preferable resin compositions, is used, first, as shown in Fig. 1(a), the substrate 10 ), the resin composition is applied to form the coating film 11.

It does not specifically limit as a coating method, For example, the well-known method using a roll coater or a spin coater can be used.

When the coating film 11 contains a volatile component such as a solvent, the volatile component may be removed from the coating film 11 as necessary.

As a method for removing volatile components, a method of placing the coating film 11 under a reduced pressure atmosphere or a method of heating the coating film 11 is preferable. However, as the dot pattern has excellent low-temperature heat-flow property, the coating film 11 is also likely to heat-flow at low temperatures. For this reason, when removing a volatile component from the coating film 11, it is placed in a pressure-reduced atmosphere as needed, and the coating film 11 is at a temperature of (Tg + 50°C or less), preferably 120 seconds or less, preferably It is preferable to heat for a short time of about 90 seconds or less.

Subsequently, after exposing the coating film 11 via a mask of a predetermined shape, the exposed coating film 11 is developed to form a dot pattern 12 as described in Fig. 1(b).

Exposure is performed by irradiating active energy rays, such as ultraviolet rays and excimer laser light, for example. The energy dose to be irradiated may vary depending on the composition of the photosensitive resin composition, but, for example, about 30 mJ/cm 2 or more and 2000 mJ/cm 2 or less is preferable.

As the developer, for example, an organic alkali aqueous solution such as an aqueous solution of tetramethylammonium hydroxide (TMAH) or an inorganic alkali aqueous solution such as sodium hydroxide, potassium hydroxide, sodium metasilicate, and sodium phosphate can be used.

The dot pattern 12 formed as described above may be bleached by front exposure. The transparency of the dot pattern 12 is improved by such bleaching.

By bleaching, the photoreaction of the photosensitive agent (B), such as a quinonediazide group-containing compound, contained in the resin composition occurs, and the transparency of the dot pattern 12 is improved.

As a method of bleaching, specifically, it is preferable to irradiate ultraviolet rays having a wavelength of 300 nm or more and 450 nm or less.

Further, even if no bleaching is performed, when the transparency of the dot pattern 12 is good, bleaching can be omitted if necessary.

<heat flow process>

If necessary, the dot pattern 12 is heat-flowed by heating the bleached dot pattern 12. The microlens pattern 13 is formed on the substrate 10 by such a heat flow.

The temperature of the heat flow is preferably (Tg + 5) °C or higher and 130 °C or lower, and more preferably (Tg + 5) °C or higher and 100 °C or lower.

When heat-flowing the dot pattern 12 formed using a resin composition at a temperature within this range, it is easy to heat-flow the dot pattern 12 to a desired degree while suppressing excessive heat flow of the dot pattern 12.

According to the method described above, the dot pattern can be heat-flowed satisfactorily even at a low temperature, whereby a microlens pattern can be satisfactorily formed.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. The present invention is not limited by these examples.

[Examples 1 to 4, Comparative Example 1, and Comparative Example 2]

In Examples 1-4, the resin (A), the photosensitive agent (B), and the solvent demonstrated below were mixed uniformly, and the photosensitive resin composition was prepared.

<Resin (A)>

In each of Examples and Comparative Examples, 100 parts by mass of the copolymer containing units represented by the following formulas A-1, A-2, and A-3 in the mass ratio shown in Table 1 below was used as the resin (A). The mass average molecular weight (Mw) of the copolymer used in each Example and the comparative example was all 8,000.

[Formula 3]

<Photosensitive agent (B)>

In each Example and each comparative example, as a photosensitizer (B), the substituent in which the hydrogen atom in the hydroxyl group of the compound represented by the following formula is substituted with the 1,2-naphthoquinonediazide-5-sulfonyl group is shown in Table 1 The amounts described were used. The substitution rate of the hydrogen atom in the hydroxyl group of the photosensitive agent by the 1,2-naphthoquinonediazide-5-sulfonyl group was 98.7 mol%.

[Formula 4]

100 parts by mass of the resin (A) and the photosensitive agent (B) in an amount shown in Table 1 were dissolved in propylene glycol monomethyl ether acetate to a solid content concentration of 24 mass%, thereby obtaining resin compositions of each of Examples and Comparative Examples . About the obtained resin composition, Tg was measured by the differential scanning calorimeter according to the method mentioned above. Table 1 shows the measurement results of Tg.

About the obtained resin composition, low temperature heat flow property was evaluated by the following method. Table 1 shows the evaluation results.

<Evaluation of low-temperature heat flow properties>

After coating the resin composition of each Example and each comparative example on a silicon substrate with a spin coater, it baked at 90 degreeC 90 seconds, and formed the coating film of 1.8 micrometers in film thickness.

After the positional exposure was performed on the formed coating film, the development was conducted for 60 seconds using an aqueous solution of tetramethylammonium hydroxide (TMAH) at a concentration of 2.38% by mass to form a dot pattern.

The shape of the surface of the dot constituting the formed dot pattern parallel to the plane direction of the substrate was a square of 4 µm × 4 µm. Moreover, the width of the space between dots was 0.5 µm.

After the formed dot pattern was heat-flowed under the conditions described in Table 1, an electron microscope image obtained by observing the surface of the substrate by electron micrograph was obtained. From the obtained electron microscope image, low-temperature heat flow property was evaluated based on the following criteria.

◎ The four sides of the dots constituting the dot pattern are deformed into an arc projecting in the space direction, and the space between dots can be clearly seen.

○ Although the heat flow of the dot pattern is confirmed, the space between dots is not well recognized.

× All four sides of the dots constituting the dot pattern are linear, and no heat flow is observed.

As can be seen from Table 1, when using a resin composition having a Tg of 70° C. or less of a resin film formed using a resin composition, measured by a predetermined method, even at a low temperature of about (Tg + 30)° C., the resin composition It can be seen that the dot pattern formed by using is well heat-flowed.

On the other hand, from the comparative example, in the case of using a resin composition having a Tg value of more than 70° C., at a low temperature of about (Tg + 30)° C., the dot pattern formed using the resin composition hardly flows. Able to know.

10: substrate
11: coating film
12: dot pattern
13: micro lens pattern

Claims (13)

A method for forming a microlens pattern by heating a dot pattern consisting of a rectangular dot and a lattice-like space and causing the dot pattern to heat flow, the resin composition used for forming the dot pattern,
The resin composition contains the resin (A),
Of the resin film formed using the resin composition, the following 1) to 4):
1) a step of spin coating the resin composition on a substrate to form a coating film,
2) a step of heating the coating film at 100° C. for 90 seconds to form a resin film,
3) a step of taking a sample for measuring a glass transition point from the obtained resin film, and measuring by differential scanning calorimetry (DSC) using the obtained sample to obtain a reverse heat flow curve, and
4) A step of determining the value of the glass transition temperature Tg by reading the minimum value in the differential curve derived by first differentiating the obtained reverse heat flow curve with temperature as the glass transition temperature Tg,
The resin composition, measured according to the method comprising the process of, has a glass transition temperature Tg of 70°C or lower. According to claim 1,
Resin composition containing alkali-soluble resin (A1) as resin (A) and photosensitive agent (B). According to claim 2,
The resin composition in which the content of the photosensitive agent (B) in the resin composition is 50% by mass or less with respect to the mass of the resin (A). According to claim 2,
The alkali-soluble resin (A1), the following formula (a1):

(In formula (a1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a single bond or an alkylene group having 1 to 5 carbon atoms, and R ³ has 1 to 5 carbon atoms. The following alkyl group, a represents an integer of 1 or more and 5 or less, b represents an integer of 0 or more and 4 or less, a+b is 5 or less, and when b is 2 or more, a plurality of R ^{3 s} are It may be the same or different)
The resin composition containing the (meth)acrylic-type resin containing the structural unit represented by. The method of claim 4,
The resin composition in which the ratio of the mass of the structural unit represented by the formula (a1) to the mass of the (meth)acrylic resin is 20% by mass or more and 80% by mass or less. The method of claim 4,
The said alkali-soluble resin (A1) further contains the structural unit derived from the alkyl ester of (meth)acrylic acid of 1 or more and 10 or less carbon atoms. According to claim 1,
The width of the space is 0.2 μm or more and 2.0 μm or less,
When the width of the space is set to W and the height of the dot is set to H, the resin composition has an aspect ratio represented by H/W of 1.0 or more and 10.0 or less. According to claim 1,
The resin composition whose temperature of the said heat flow is (the said Tg+5) degreeC or more and 130 degreeC or less. The method of claim 8,
The resin composition in which the temperature of the heat flow is (Tg + 5) °C or higher and 100 °C or lower. The process of forming a dot pattern which consists of a square dot and a lattice-shaped space on a board|substrate using the resin composition in any one of Claims 1-9,
A method of manufacturing a substrate having a microlens pattern, comprising a heat flow step of heat-flowing the dot pattern by heating. The method of claim 10,
The width of the space is 0.2 μm or more and 2.0 μm or less,
When the width of the space is W and the height of the dot is H, the aspect ratio expressed in H/W is 1.0 or more and 10.0 or less,
The manufacturing method of the board|substrate with a microlens pattern which performs the formation of the said dot pattern using the said resin composition. The method of claim 10,
The temperature of the heat flow is (Tg + 5) °C or higher and 130 °C or lower,
The manufacturing method of the board|substrate with a microlens pattern which performs the formation of the said dot pattern using the said resin composition. The method of claim 10,
The temperature of the heat flow is (Tg + 5) ℃ or more and 100 ℃ or less,
The manufacturing method of the board|substrate with a microlens pattern which performs the formation of the said dot pattern using the said resin composition.

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