JPH0693120B2 - Photosensitive composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a photosensitive composition and a solid-state image sensor using the same for forming a micro color filter.

[Prior art]

Conventionally, as a method for providing a color filter on a solid-state imaging device made of a semiconductor substrate incorporating a photodetection section or the like, a layer containing a photosensitive resin (photoresist layer) on the solid-state imaging device or on another glass substrate or the like. Was coated, exposed to ultraviolet light through a predetermined mask, and then developed with water or an aqueous solution to form a predetermined pattern, which was colored to form a color filter. In the latter case, it was formed. A method of bonding a color filter onto a solid-state image sensor is known.

In such a method, as a photoresist for a color filter, a photosensitive composition obtained by adding a dichromate to an aqueous gelatin solution is used (for example, JP-A-58-33208).

[Problems to be solved by the invention]

However, since the dichromate is subject to pollution control, the use of such compounds poses a serious environmental hygiene problem. In order to prevent such pollution problems, a photosensitive composition using a diazonium salt or an azide compound as a photosensitive component in place of the dichromate is known (for example, Japanese Patent Publication No.
59-52549). However, diazonium salts and azide compounds have a drawback that the coating solution composition for forming a photosensitive layer, the photosensitive film after coating and drying, and the like have poor stability over time.

Further, a photosensitive composition obtained by adding a styrylpyridinium group to polyvinyl alcohol (for example, Japanese Patent Publication No. 56-5761) or a photosensitive composition obtained by adding a stilbazolium group to a vinyl acetate polymer (for example, JP-A-60- No. 10243, 60-1
No. 0244). However, although such a composition has characteristics such as no pollution and high sensitivity when used as a material for a microfilter, it is inferior in heat resistance, adhesiveness, dyeability, etc. and has a problem in practical use. .

Therefore, an object of the present invention is to provide a photosensitive composition which does not cause pollution problems and the like, has high sensitivity, and is excellent in heat resistance, adhesiveness, dyeability and the like.

Another object of the present invention is to provide a color solid-state imaging device in which a color filter is formed using the above-mentioned photosensitive composition.

[Means for solving problems]

As a result of intensive studies to solve the above problems, the present inventors have made gelatin or casein a hydrophilic polymer and imparted a stilbazolium group as a photosensitive group, particularly a stilbazolium group represented by the following general formula (I). The present invention has been accomplished by finding that the hydrophilic photosensitive gelatin or photosensitive casein prepared as above is suitable as a dyeing material for a color filter of a color solid-state imaging device or a photosensitive composition in the printing field (including printed wiring). .

That is, the present invention is characterized by comprising a liquid (aqueous solution or aqueous dispersion or solid) containing gelatin or casein having a stilbazolium group as a photosensitive group, particularly a stilbazolium group represented by the following general formula (I). And a photosensitive composition.

Where R₁Is a hydrogen atom, an alkyl group, or an aralkyl group
Represents R₂Represents a hydrogen atom or an alkyl group, X
Represents an anion, and * represents gelatin or via a linking group.
Represents the binding position for binding casein.

Hereinafter, the present invention will be described in detail.

The photosensitive gelatin used in the present invention can be easily synthesized by reacting a stilbazolium salt (styrylpyridinium salt) represented by the following general formula (II) with gelatin or casein in water.

Where R₁， R₂, And X Represents the same as general formula (I)
Where L represents a divalent linking group, R₃Is gelatin or mosquito
Represents an electrophilic reactive group capable of reacting with the amino group of zein.
However, n represents 0 or 1.

In the above general formulas (I) and (II), R ₁ is a hydrogen atom, an alkyl group (unsubstituted alkyl group: for example, methyl group, ethyl group, propyl group, 2,2-dimethylpropyl group, n-hexyl group, 2- Substituted alkyl groups such as ethylhexyl group: for example, allyl group, 2-hydroxyethyl group, propargyl group, 2-butenyl group, carbamoylmethyl group and the like, and aralkyl group (for example, benzyl group, diphenylmethyl group, p-methylbenzyl group, p-chlorobenzyl group, naphthylmethyl group, etc.), a hydrogen atom,
A methyl group, an ethyl group, an allyl group, a 2-hydroxyethyl group, a carbamoylmethyl group and a benzyl group are particularly preferable.

R ₂ represents a hydrogen atom or an alkyl group selected from the same group as R ₁ , and a hydrogen atom and a methyl group are particularly preferred.

R ₃ is an electrophilic reactive group capable of reacting with the amino group of gelatin, for example, an aldehyde group, an acetal group, an active halogen group, an epoxy group, an N-methylol group, an active ester group,
It represents an active vinyl group, an isocyanate group, a triazine group or the like, and an aldehyde group, an epoxy group or an active vinyl group is particularly preferable.

L represents a divalent linking group such as a methylene group, an ethylene group, a propylene group, a phenylene group, a p-xylylene group, a trimethylene group, a neopentylene group, an oxyethylene group, and a polyoxyethylene group, and a methylene group, an ethylene group. , Oxyethylene group and polyoxyethylene group are particularly preferable.

X in the general formula (II) Is an anion such as halogen
Ions (eg chloride, bromide, iodide)
), Methylsulfate ion, p-toluenesulfonate ion
Ion, acetate ion, methanesulfonate ion, etc.,
Chlorine ion, bromine ion, methyl sulfate ion, p-tolu
The ensulfonate ion is particularly preferred.

Preferred specific examples of the stilbazolium salt used for the reaction with gelatin or casein in the present invention are shown below.

In the reaction of the stilbazolium salt represented by the general formula (II) of the present invention with gelatin or casein, the stilbazolium salt is 1 to 30 m based on 100 g of gelatin or casein.
It is preferable to use mol.

When the solubility in stilbazolium salt water is low, methanol, ethanol or the like can be used as an auxiliary solvent, but the amount thereof is preferably 20 wt% or less with respect to water.

The reaction temperature is preferably 36 ° C to 60 ° C or lower.

The following is a synthesis example of gelatin having a stilbazolium group in the side chain of the present invention.

Synthesis Example 1 10 g of 680 gelatin was dissolved in 100 ml of distilled water, 1.3 g of the stilbazolium salt of Specific Example (1) was added, and heating was continued at 40 ° C. for 6 hours. Then, cool to room temperature, add 500 ml of distilled water, perform dialysis for 2 days with a semipermeable membrane of cellulose,
Lyophilization gave 8.8 g of white powder.

The introduction rate of stilbazolium groups into this gelatin is described in
2.1 mmol when measured according to the same method as 55-23163
/ 100g gelatin.

Also, it was possible to synthesize casein having a stilbazolium group in its side chain in the same manner as described above, using casein instead of gelatin.

The photosensitive composition of the present invention is obtained by dissolving or dispersing the above-mentioned photosensitive gelatin or casein in water. In this case, the photosensitive gelatin or casein can be sufficiently used alone, but various additives such as a photopolymerization initiator and a dye can be contained depending on the purpose of use.

The photosensitive composition of the present invention is particularly useful as a dyeing material as a photoresist for a micro color filter of a color solid-state image pickup device. That is, the photosensitive composition of the present invention is applied and dried on a solid-state imaging device composed of a semiconductor substrate having a photodetection section and the like, and then irradiated with ultraviolet rays through a predetermined mask, developed with water or a washing solution, and then subjected to predetermined treatment. Pattern is formed, and the pattern is dyed to form a micro color filter. (Repeat this operation for multicolor filters). It can also be used in a method in which a photosensitive composition is coated on a glass substrate, a micro color filter is formed on the glass substrate as described above, and the micro color filter is attached to a solid-state image sensor. That is, according to the present invention, a photosensitive gelatin (or casein) composition containing no dichromate is used instead of the conventional photosensitive composition comprising gelatin (or casein) and dichromate. The characteristics of gelatin can be used as they are without causing pollution problems due to dichromate, and a microcolor filter excellent in dyeability, stability over time, and adhesion can be formed.

Further, the photosensitive composition of the present invention is not limited to the above-mentioned case, and is also used as a photosensitive composition used in the conventional printing field (relief printing, intaglio printing, lithographic printing, etc.) or in the production of printed wiring such as IC circuits. be able to.

The photosensitive composition using the low molecular weight photosensitive gelatin or casein (aqueous dispersion) used in the present invention is a water-soluble photosensitive material which can be dissolved, coated and developed at room temperature. When used in the above fields, temperature around room temperature (25 ℃ ± 5 ℃)
It has the advantage that it can be handled with.

〔Example〕

Next, the present invention will be specifically described with reference to examples. In addition,
In order to show the effect of the present invention, a comparative example using a conventional photosensitive composition is also shown.

Comparative Example 1 A photosensitive composition having the following composition was coated on a transparent glass substrate using a spinner coating machine so that the film thickness after drying was 1.0 micron, and dried at room temperature for 15 minutes to form a filter forming layer. .

Photosensitive layer coating solution Gelatin 10 g Ammonium dichromate 1 g Water 100 ml A pattern mask consisting of a mosaic pattern is placed on this filter forming layer and vacuum-bonded, then with a 500 W high pressure mercury lamp.
After exposure for 40 seconds, the filter forming material is immersed in warm water at 43 ° C for 10 minutes, and development processing is performed to dissolve and remove the non-crosslinked portion of the filter forming layer to form a mosaic photocrosslinked relief image. Created.

Next, this photocrosslinking relief image was dyed by immersing it in a cyan dyeing solution having the following composition for 8 minutes at 43 ° C.

Staining liquid composition Copper phthalocyanine (tetra) Sulfonic acid (tetra) pyridinium salt 0.5 g pH about 6 buffer solution 1 2 Water containing ammonium acetate 29.6 g and acetic acid 0.96 ml This cyan colored filter material A cyan filter (1) (Comparative Example 1) was prepared by immersing in a rinse liquid (containing 1.5 ml of acetic acid in water 1) for 30 seconds, washing and drying.

Comparative Example 2 A cyan filter 2 (Comparative Example 2) was prepared in the same manner as in Comparative Example 1 except that a photosensitive composition having the following composition was applied on a transparent glass substrate to a dry film thickness of 1 micron. )made.

Photosensitive layer composition Polyvinyl alcohol 10 g (Kuraray, PVA-220, saponification degree 87.6%, degree of polymerization 2000) Water 100 ml Ammonium dichromate 2 g However, the developing conditions and dyeing conditions were changed as follows.

Development condition 25 ° C. for 2 minutes Dyeing condition 25 ° C. for 8 minutes Comparative Examples 3 to 4 A photosensitive solution having the following composition was applied on a transparent glass substrate to a dry film thickness of 1 micron, and dried at room temperature for 10 minutes. ,
Cyan filters 3 and 4 (Comparative Examples 3 and 4) were prepared in the same manner as in Comparative Example 2 except that the baking treatment was carried out at 80 ° C. for 15 minutes.

Photosensitive Solution Composition Comparative Example 3 PVA-Stilbazolium (PVA Polymerization Degree 1700, Saponification Degree 88% Stilbazolium Group Content 1.24 Mol% 7.5% Aqueous Solution (wt%)) Comparative Example 4 PVA-Stilbazolium (PVA Polymerization Degree 500, Saponification Degree 88% Stilbazolium group content 4.2Mol% 7.5% Aqueous solution (wt%)) Example 1 Preparation of cyan filter (invention) 150 ml of gelatin-stilbazolium salt compound powder synthesized in Synthesis Example 1 on the above glass substrate. A cyan filter 5 was prepared in the same manner as in Comparative Examples 3 to 4 except that the photosensitive composition dissolved in distilled water in Example 1 was applied.

Next, with respect to the cyan filters 1 to 5 prepared as described above, the spectral optical density at 630 nm was measured (manufactured by Olympus Corp., MMSP microspectrophotometer), and the results in Table 1 were obtained.

As is apparent from these results, the dyeing index (D / μ, dyeing density per unit film thickness) of the filter of the present invention (D / μ, the dyeing density per unit film thickness) is extremely higher than that of the comparative ones (filters (1) to (4)). As a result, it was found that the film thickness of the filter can be made half as thin as that of the filter (1) .By making the film thin, the resolution is remarkably high and the pattern reproducibility is excellent. In addition, it was found that the dyeing treatment did not cause decolorization (color loss) with the rinse solution.

Example 2 The photosensitive composition used in the cyan filter 5 of Example 1 was applied onto a transparent glass plate.

This filter forming layer was exposed to ultraviolet light through a mask having a stripe pattern of the first color filter color element, and then developed with cold water at 23 ° C. for 30 seconds to form a relief image. Next, using a dyeing solution of the following composition, 40
The dyeing treatment was performed at 8 ° C. for 8 minutes. The film thickness after dyeing and drying was 1.2 μm.

Dyeing liquid composition Water 1 Suminol Milling Brilliant Sky Blue SE 0.5g After adding acetic acid to pH 3.0, dyeing, immersing in rinse solution for 30 seconds, washing, tannic acid treatment and tartar treatment. Was done.

Dye-proof treatment First treatment: Immersed in an aqueous solution prepared by dissolving 2 g of tannic acid and 10 cc of acetic acid in water 1 at 25 ° C. for 2 minutes and then washed with water for 1 minute.

Second treatment: Next, the first color filter element was prepared by immersing in an aqueous solution of tartarite (5 g) and acetic acid (2.5 cc) in water 1 at 25 ° C. for 2 minutes, washing with water for 1 minute and drying.

Then, after baking at 170 ° C. for 20 minutes, a photosensitive solution having the same composition as the first color was used to prepare a second color filter color element in the same procedure as described above. However, the dyeing process was carried out at 40 ° C. for 3 minutes in the dyeing step. The film thickness after dyeing and drying is 1.6
It was micron.

Staining liquid composition Water 1 Kiton Green C-I 9 0.3 g Direct Farst Yellow BC 0.5 g Acetic acid was added to pH 3.4 Further, a third color filter element was prepared by the same procedure as above. However, the dyeing process was carried out at 40 ° C. for 4 minutes using the following dyeing solution. The film thickness after dyeing and drying was 1.7 μm.

Dyeing liquid composition Water 1 Suminol FASTRED G 3g Acetic acid was added to pH 3.0, and 1 micron thick ethyl P-phenylene diacrylate and equimolar 1,4-bis (β-hydroxyethoxy)- Copolymer with cyclohexanone (2 as sensitizer
(Benzoylmethylene-1-methyl-β-naphthothizoline, 2% by weight).
After pre-baking at 150 ° C for 10 minutes, UV-exposure is performed using a mask (exposure pattern) that covers the bonding butter and the dicing cut, and exposes the pixel area. Done. Then, development was carried out with r-butyrolactone to elute and remove unexposed portions of the resin (bonding pad portion and dicing cut portion). Then, post-baking at 170 ℃ for 40 minutes, blue, red,
A multicolor optical filter consisting of green was created.

Example 3 A CCD image sensor having a surface smoothed with a photosensitive composition having the same composition as the overcoat of Example 3 was prepared.
A color filter layer was formed on the smooth surface of this CCD image sensor in the same manner as in Example 2. Next, this CCD image pickup device was cut using a diamond cutter while applying a water shower, and separated into each color solid-state image pickup device. The cut and separated color solid-state imaging device was ultrasonically cleaned with a solvent such as water, trichlene, and Freon to remove chips and oil adhering to the surface for cleaning. The color image sensor thus obtained is subsequently transferred to the wire bonding step, but when observed under a microscope with a microscope before wire bonding, film peeling and elution were observed in the overcoat layer and the colored resin film. The changes to filters such as bleaching, color mixing, and opacity were never noticed. Next, this was left to stand in an oven at 200 ° C. for 3 hours, subjected to a thermotest, and then observed under a microscope. Here, no change was noticeable. Therefore, it has been found that the color filter layer according to the present invention is also very excellent in heat resistance. This was wire-bonded and packaged, incorporated into a CCD color camera, and as a result of shooting, a color image with good color reproducibility was reproduced on a cathode ray tube.

[Advantages of the Invention] As described above, the photosensitive composition according to the present invention has no pollution, has excellent stability over time, has high sensitivity, and has extremely excellent adhesion, heat resistance, and dyeability. Has the effect of being

Claims (3)

[Claims] 1. A photosensitive composition comprising an aqueous solution or dispersion containing gelatin or casein having a stilbazolium group as a partial structure as a photosensitive group. 2. A stilbazolium group has the following general formula (1):
The group represented by claim (1), which is a group represented by
Photosensitive composition.However, in the above general formula, R₁Is a hydrogen atom, alkyl
A group or an aralkyl group, R₂Is a hydrogen atom or
Represents a kill group, X Represents an anion, * represents a linking group
The binding position for binding to gelatin or casein via
Forget 3. A color solid-state imaging device having a color filter having an organic polymer material layer as a layer to be colored on a solid-state imaging device, wherein the organic polymer material layer has a stilbazolium group as a partial structure as a photosensitive group. A color solid-state image pickup device characterized by being formed of the gelatin.