U.S. patent application number 10/893983 was filed with the patent office on 2005-01-13 for color filter array having a yellow filter layer.
This patent application is currently assigned to Sumitomo Chemical Company, Limited. Invention is credited to Endo, Hiroki, Machiguchi, Kazuhiro, Sayama, Yukihiro, Uchida, Yoshinori, Ueda, Yuuji.
Application Number | 20050008954 10/893983 |
Document ID | / |
Family ID | 18697009 |
Filed Date | 2005-01-13 |
United States Patent
Application |
20050008954 |
Kind Code |
A1 |
Machiguchi, Kazuhiro ; et
al. |
January 13, 2005 |
Color filter array having a yellow filter layer
Abstract
A color filter array having a yellow filter layer on a substrate
wherein the yellow filter layer comprises a pyridone azo dye having
its absorption maximum at a wavelength of 400 to 500 nm; and has a
transmittance at a wavelength of 450 nm of 5% or less, that at 535
nm of 80% or more and that at 650 nm of 90% or more is provided;
the color filter array shows excellent spectroscopic
characteristics with respect to yellow light, is capable of forming
a pattern with a short time exposure and has a yellow filter layer
excellent in light fastness; and a photosensitive resin composition
with which a pattern can be formed with a short time exposure is
also provided.
Inventors: |
Machiguchi, Kazuhiro;
(Osaka, JP) ; Ueda, Yuuji; (Osaka, JP) ;
Endo, Hiroki; (Tokyo, JP) ; Uchida, Yoshinori;
(Tokyo, JP) ; Sayama, Yukihiro; (Kokubu-shi,
JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
Sumitomo Chemical Company,
Limited
Sony Corporation
|
Family ID: |
18697009 |
Appl. No.: |
10/893983 |
Filed: |
July 20, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10893983 |
Jul 20, 2004 |
|
|
|
09893551 |
Jun 29, 2001 |
|
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Current U.S.
Class: |
430/7 |
Current CPC
Class: |
G02B 5/201 20130101 |
Class at
Publication: |
430/007 |
International
Class: |
G02B 005/20 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 2000 |
JP |
2000-198914 |
Claims
What is claimed is:
1. A color filter array having a yellow filter layer on a substrate
wherein the yellow filter layer comprises a pyridone azo dye having
its absorption maximum at a wavelength of 400 to 500 nm; and has a
transmittance at a wavelength of 450 nm of 5% or less, that at 535
nm of 80% or more and that at 650 nm of 90% or more.
2. A process for producing a color filter array having a yellow
filter layer on a substrate which comprises the step of patterning
a photosensitive resin composition comprising a pyridone azo dye
having its absorption maximum at a wavelength of 400 to 500 nm to
form the yellow filter layer having a transmittance at a wavelength
of 450 nm of 5% or less, that at 535 nm of 80% or more and that at
650 nm of 90% or more.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to color filter arrays for
solid-state image devices or liquid crystal display devices, and to
a method for producing the same.
[0002] As a color filter array formed on a device such as a
solid-state image device or a liquid crystal display device, there
has been known a color filter array (2) constituted of a yellow
filter layer (Y), a magenta filter layer (M), and a cyan filter
layer (C) formed so as to be adjoining to each other in the same
plane of a substrate (1) (FIG. 1). In the color filter array (2),
the filter layers (Y), (M), (C) are arranged in a striped pattern
(FIG. 2) or a lattice-like pattern (mosaic) (FIG. 3).
[0003] A variety of processes for producing such color filter array
have been proposed. Among them, so-called "color resist method" is
in wide practical use. In the color resist method, the patterning
is effected by exposing a photosensitive resin composition
comprising colorants to light and developing, and the patterning is
repeated in sequence in the required times.
[0004] As the photosensitive resin composition which is employed in
the color resist method, those employing pigments as colorants are
in wide use. However, such pigments are not suitable for the
formation of fine or minute patterns., for they are granular and do
not dissolve in developers, and developing residue is
generated.
[0005] As a photosensitive resin composition for obtaining a finely
patterned color filter array, a photosensitive resin composition
employing dyes as colorants has also been known. For example,
Japanese Patent Application Laid-Open No. 6-75375 discloses a
negative photosensitive resin composition comprising dyes, and
Japanese Patent Publication No. 7-111485 discloses a positive
photosensitive resin composition comprising 10 to 50%, on a dry
weight basis, of a dye soluble in the solvent used in the positive
photosensitive resin composition. (Hereinafter, "JP-A-" is used for
indicating Japanese Patent Application Laid-Open, and "JP-B-" is
used for indicating Japanese Patent Publication.)
[0006] Colorants comprised in photosensitive resin compositions
used for producing color filter arrays, such as those described
above, are required to have the following two properties.
[0007] (1) Good transmittance property to the exposure light, that
is, having high transmittance to the exposure light used for
forming the pattern and capable of forming a pattern with a short
time exposure.
[0008] (2) Good light fastness, that is, no burn-in due to the
decolorization of dyes under normal operating conditions
[0009] However, none of the dyes employed in conventional
photosensitive resin compositions has both of the above-described
two properties.
[0010] For example, as a dye to be incorporated in a yellow film
layer, a pirazolone azo dye (C.I. Solvent Yellow 88) is described
in Japanese Patent Publication No. 7-111485. (Hereinafter, "JP-A-"
is used for indicating Japanese Patent Application Laid-Open, and
"JP-B-" is used for indicating Japanese Patent Publication.)
However, this dye exhibits high absorption of visible ray and near
ultraviolet ray, such as i-line and g-line, and use of this dye
makes the exposure time longer. According to JP-B-7-111485, the
exposure time is 20 second to form a yellow filter layer using the
dye.
[0011] A colorant exhibiting a small absorption of visible ray and
near ultra violet ray. However, generally colorants exhibiting a
small absorption of visible ray and near ultra violet ray is not
satisfactory in light fastness. Further, such a dye has low
solubility in a photosensitive resin composition, and a
photosensitive resin composition containing the dye at a high
concentration cannot be easily obtained easily.
[0012] Therefore, it has been difficult to manufacture a color
filter array having a practical yellow filter layer.
[0013] The inventors of the present invention have made intensive
and extensive studies to develop a color filter array having a
yellow filter layer having good transmittance property, which
enables to form the layer in a short time, as well as good light
fastness. As a result, they have found that the use of a specific
dye enables the formation of a yellow filter layer satisfactory in
light fastness with a short exposure time. The present invention
was 0.3 accomplished based on this finding.
SUMMARY OF THE INVENTION
[0014] The present invention provides a color filter array having a
yellow filter layer on a substrate wherein the yellow filter layer
comprises
[0015] a pyridone azo dye (hereinafter, referred to as "dye (I)")
having its absorption maximum at a wavelength of 400 to 500 nm;
and
[0016] has a transmittance at a wavelength of 450 nm of 5t or less,
that at 535 nm of 80% or more and that at 650 nm of 90% or
more.
[0017] The present invention also provides a process for producing
the color filter array.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [FIG. 1]
[0019] FIG. 1 is a schematic view showing a cross-section of a
color filter array in which a yellow filter layer, a magenta filter
layer, and a cyan filter layer are provided in the same plane of a
substrate.
[0020] [FIG. 2]
[0021] FIG. 2 is a plane schematic view of a color filter array
provided with a yellow filter layer, a magenta filter layer, and a
cyan filter layer arranged in a striped pattern.
[0022] [FIG. 3]
[0023] FIG. 3 is a plane schematic view of a color filter array
provided with a yellow filter layer, a magenta filter layer, and a
cyan filter layer arranged in a mosaic pattern.
[0024] [FIG. 4]
[0025] FIG. 4 is a plane schematic view of the color filter array
obtained in Example 1.
[0026] [FIG. 5]
[0027] FIG. 5 is a plane schematic view of the color filter array
obtained in Example 1.
[Description of Reference Numerals]
[0028] 1: substrate
[0029] 2: color filter array
[0030] Y: yellow filter layer
[0031] M: magenta filter layer
[0032] C: cyan filter layer
EMBODIMENT OF THE INVENTION
[0033] As the substrate used in the color filter of the present
invention, a silicon wafer and a transparent inorganic glass plate
are exemplified. On the silicone wafer, a charge coupled device may
be formed.
[0034] The color filter array of the present invention has a yellow
filter layer on its substrate.
[0035] The yellow filter layer comprises a dye (I) having its
absorption maximum at a wavelength of 400 to 500 nm. Concrete
examples of the dye (I) include compounds represented by the
general formula (I): 1
[0036] wherein R.sup.10 represents an alkyl group having 2 to 10
carbon atoms; R.sup.11, R.sup.12, and R.sup.14 each independently
represents hydrogen atom, methyl group, hydroxyl group, or cyano
group; and R.sup.13 represents an alkyl group having 1 to 4 carbon
atoms. By incorporating such a dye, a yellow filter layer having a
transmittance at a wavelength of 450 nm of 5% or less, that at 535
nm of 80% or more and that at 650 nm of 90% or more can be
obtained.
[0037] Examples of the alkyl group having 2 to 10 carbon atoms and
represented by R.sup.10 in the general formula (II) include ethyl
group, propyl group, n-hexyl group, n-nonyl group, n-decyl group,
n-dodecyl group, 2-ethylhexyl group, 1,3-dimethylbutyl group,
1-methylbutyl group, 1,5-dimethylhexyl group, and
1,1,3,3-tetramethylbutyl group. Examples of the alkyl group having
1 to 4 carbon atoms and represented by R.sup.13 include methyl
group, ethyl group, propyl group, and butyl group.
[0038] Examples of the dye (I) include C.I. Solvent Yellow 162.
These are used singly or in combination. These dyes (I) have their
absorption maximum at a wavelength within the range of from 400 to
500 nm, and have low absorption of i-line and g-line.
[0039] For improving light fastness and controlling the color, that
is, control of its spectroscopic characteristics, other dyes may be
incorporated into the yellow filter layer. One kind of the other
dye may be used or two or more of them may be used in
combination.
[0040] The transmittance of the yellow filter layer is 5% or less
at a wavelength of 450 nm, 80% or more at 535 nm and 90% or more at
650 nm.
[0041] The color filter array of the present invention can be
produced by an ordinary color resist method. For example, it can be
produced by a process comprising the step of patterning a
photosensitive resin composition comprising colorants. The
photosensitive resin composition comprises the dye (I).
[0042] The photosensitive resin composition may be a positive
photosensitive resin composition or a negative photosensitive resin
composition.
[0043] The positive photosensitive resin composition of the present
invention comprises, for example, a photoactive compound and an
alkali-soluble resin in addition to the above-described dyes.
[0044] A photoactive compound used in conventional
photosensitive-resin compositions can be used in the positive
photosensitive resin composition of the present invention. Examples
thereof include esters of phenolic compounds with
o-naphthoquinonediazide sulfonates. Examples of the phenolic
compounds include compounds represented by the chemical formula
(10). 2
[0045] As the o-naphthoquinonediazide sulfonates,
o-naphthoquinonediazide-- 5-sulfonate and
o-naphthoquinonediazide-4-sulfonate can be exemplified.
[0046] The term "alkali-soluble resin" refers to resins that
dissolve in alkaline developers, and any alkali-soluble resin
similar to those used in conventional photosensitive resin
compositions can be employed. Examples of such alkali-soluble
resins include novolak resins such as those of p-cresol novolak
resins, novolak resins of p-cresol and m-cresol; novolak resins
having the structure represented by the formula (20): 3
[0047] polyvinylphenol; and copolymers of styrene with vinylphenol.
Preferably, a novolak resin is employed as the alkali-soluble
resin.
[0048] The amounts of the dyes, the photoactive compound, and the
alkali-soluble resin comprised in the photosensitive resin
composition are usually 10 to 50 parts by weight, 10 to 50 parts by
weight, and 3 to 50 parts by weight, per a total of 100 parts by
weight of the dyes, photoactive compound, and alkali-soluble resin,
respectively.
[0049] Into the positive photosensitive resin composition, a curing
agent may be incorporated. Incorporation of the curing agent
improves the mechanical strength of the pattern formed by using the
photosensitive resin composition.
[0050] As the curing agent, usually, a heat curing agent which is
cured through heating is employed. Examples of the heat curing
agent include compounds represented by the general formula (30):
4
[0051] wherein Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 each
independently represents hydrogen atom, a hydroxyalkyl group having
1 to 4 carbon atoms, or an alkyl group having 1 to 4 carbon atoms
and substituted with an alkoxyl group having 1 to 4 carbon atoms; Z
represents phenyl group or a group represented by the general
formula (31):
Q.sup.5Q.sup.6N-- (31)
[0052] wherein Q.sup.5 and Q.sup.6 each independently represents
hydrogen atom, a hydroxyalkyl group having 1 to 4 carbon atoms, or
an alkyl group having 1 to 4 carbon atoms and substituted with an
alkoxyl group having 1 to 4 carbon atoms
[0053] with the proviso that at least one of Q.sup.1 to Q.sup.6 is
a hydroxyalkyl group having 1 to 4 carbon atoms or an alkyl group
having 1 to 4 carbon atoms and substituted with an alkoxyl group
having 1 to 4 carbon atoms.
[0054] Examples of the hydroxyalkyl group having 1 to 4 carbon
atoms include hydoxymethyl group, hydroxyethyl group, hydroxypropyl
group, and hydroxybutyl group. Examples of the alkyl group having 1
to 4 carbon atoms and substituted with an alkoxyl group having 1 to
4 carbon atoms include methoxymethyl group, methoxyethyl group,
ethoxyethyl group, and propoxybutyl group.
[0055] An example of the compound represented by the general
formula (30) is hexamethoxymethylmelamine.
[0056] Moreover, compounds of the following chemical formulae (32)
to (37) can be used as the curing agent in the positive
photosensitive resin composition of the present invention, for
example. 5
[0057] When the curing agent is used, its content is usually not
less than 10 parts by weight and not more than 35 parts by weight
per a total of 100 parts by weight of the dyes, the photoactive
compound, and the alkali-soluble resin.
[0058] The positive photosensitive resin composition of the present
invention is usually diluted with a solvent.
[0059] The solvent is suitably selected according to the
solubilities of the dye (I), photoactive compound, alkali-soluble
resin, and curing agent. For example, methyl cellosolve, ethyl
cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate,
diethylene glycol dimethyl ether, ethylene glycol monoisopropyl
ether, propylene glycol monomethyl ether, N-methylpyrrolidone,
.gamma.-butyrolactone, dimethyl sulfoxide, N,N'-dimethylformamide,
cyclohexane, ethyl acetate, n-butyl acetate, propylene
glycolmonoethyl ether acetate, ethyl acetate, ethyl pyruvate, ethyl
lactate, or the like can be employed. These solvents are used
either singly or in combination.
[0060] The amount of the solvent to be used is usually about 180 to
400 parts by weight per a total of 100 parts by weight of the dyes,
photoactive compound, alkali-soluble resin, and curing agent.
[0061] The negative photosensitive resin composition of the present
invention comprises, for example, a photoreactive acid generator, a
curing agent, and an alkali-soluble resin, in addition to the dyes
described above.
[0062] A photoreactive acid generator use in conventional negative
photoreactive resin compositions can be employed as the
photoreactive acid generator used in the negative photosensitive
resin composition of the present invention. Examples thereof
include compounds represented by the general formula (40): 6
[0063] wherein Q.sup.7 represents an alkyl group having 1 to 3
carbon atoms, and Q.sup.8 represents a phenyl group substituted
with an alkyl group having 1 to 3 carbon atoms or a phenyl group
substituted with an alkoxyl group having 1 to 3 carbon atoms.
[0064] Examples of the alkyl group having 1 to 3 carbon atoms
represented by Q.sup.7 include methyl group, ethyl group, and
propyl group. An example of the phenyl group substituted with an
alkyl group having 1 to 3carbon atoms and represented by Q.sup.8 is
o-isopropylphenyl group. Examples of the phenyl group substituted
with an alkoxyl group having 1 to 3 carbon atoms include
p-methoxyphenyl group, p-ethoxylphenyl group, and p-propoxyphenyl
group.
[0065] Moreover, compounds represented by the chemical formulae
(41) to (47): 7
[0066] can also be used as the photo acid generator, for
example.
[0067] As the curing agent, a heat curing agent which is cured
through heating is usually employed as in the case of conventional
negative photosensitive resin composition. The heat curing agents
listed above as examples for the positive photosensitive resin
composition can also be employed in the negative photosensitive
resin composition of the present invention.
[0068] The alkali-soluble resins listed above as examples for the
positive photosensitive resin composition can also be employed in
the negative photosensitive resin composition of the present
invention, as in the case of conventional negative photosensitive
resin composition.
[0069] The amounts of the photo acid generator, curing agent, and
alkali-soluble resin comprised in the negative photosensitive resin
composition per a total of 100 parts by weight of the dyes,
photoreactive acid generator, curing agent, and alkali-soluble
resin are as follow. The content of the dyes is usually about 15 to
40 parts by weight, and that of the photo acid generator is usually
0.3 to 5 parts by weight. The amount of the curing agent to be used
is usually 10 to 25 parts by weight, and the content of the
alkali-soluble resin is usually 20 to 75 parts by weight.
[0070] The negative photosensitive resin composition is usually
diluted with a solvent.
[0071] The solvent is selected according to the solubilities of the
dye (I), photo acid generator, alkali-soluble resin, and curing
agent, especially according to the solubilities of the dye (I), dye
(II), dye (III), and dye (IV). The solvent listed above as examples
for the positive photosensitive resin composition can be employed.
The amount of the solvent to be used is usually about 180 to 400
parts by weight per a total of 100 parts by weight of the dyes,
photo acid generator, curing agent, and alkali-soluble resin.
[0072] Since the above-described photosensitive resin composition
employs the dye (I) as its colorant, almost no precipitate is
generated even if the composition is stored for a long period of
time. Consequently, the composition can be applied onto the
substrate practically without irregularities. This makes it
possible to provide a color filter array having a yellow filter
layer with a pattern of about 0.5 to 2 .mu.m in thickness and about
2 to 20 .mu.m in length of each side.
[0073] The patterning is effected, for example, by providing a coat
of the above-described resin composition on a substrate, exposing
the coat to light, and then developing.
[0074] The coat is provided on the substrate by applying a diluted
photosensitive resin composition thereto. The composition is
usually applied by spin coating. After the composition has been
applied onto the substrate, the coat is heated up to, for example,
about 80 to 130.degree. C. to evaporate the solvent comprised
therein. Thus, a coat of the photosensitive resin composition is
obtained.
[0075] Thereafter, the coat is exposed to light. The exposure to
light involves the use of a mask pattern corresponding to the
desired pattern, and is effected by irradiating the coat with a
beam through the mask pattern. As the beam for the exposure of the
coat to light, for example, g-ray, i-ray, or the like can be
employed. Such an exposure equipment as the g-ray stepper or i-ray
stepper may be employed for the exposure.
[0076] Using the photosensitive resin composition, a pattern can be
formed with a short time exposure.
[0077] When a negative photosensitive resin composition is used,
the coat is heated after the exposure to light. When the positive
photosensitive resin composition is used, the coat may be heated
after the exposure or may not be heated. On heating the coat, the
heating temperature is, for example, about 80 to 150.degree. C.
[0078] After having been exposed to light, the coat is subjected to
development. The development is effected by immersing the substrate
provided with the coat in a developer, as in the case of the use of
an ordinary photosensitive resin composition. Developer used for
patterning conducted by using a conventional photosensitive resin
composition can also be employed in patterning in the present
invention. A color filter array having a yellow filter layer
defined in the desired pattern can be obtained by taking the
substrate out of the developer and then washing with water to
remove the developer.
[0079] When a positive photosensitive resin composition is used,
after having been washed with water, the substrate may be subjected
to ultraviolet ray irradiation. Irradiation of ultraviolet rays can
decompose the remaining photoactive compound. Moreover, when the
photosensitive resin composition comprises a heat curing agent, the
substrate may be heated after having been washed with water. By
heating, the mechanical strength of the formed yellow filter layer
can be improved. The heating temperature is usually not lower than
160.degree. C. and not higher than 220.degree. C. Usually, the
heating temperature is not higher than the decomposition
temperatures of the dyes.
[0080] When a negative photosensitive resin composition is used,
the substrate may be heated after having been washed with water. By
heating, the mechanical strength of the formed yellow filter layer
is improved. The heating temperature is usually not lower than
160.degree. C. and not higher than 220.degree. C. Usually, the
heating temperature is not higher than the decomposition
temperatures of the dyes.
[0081] Thus, a yellow filter layer in the desired pattern is
formed. Transmittances of the yellow filter layer thus formed are
preferably 5% or less at a wavelength of 450 nm and 80% or more at
535 nm.
[0082] The other filter layers, that is, a magenta filter layer and
a cyan filter layer are formed in the same plane of the substrate
which has been provided with the yellow filter layer, according,
for example, to a conventional manner. When employing a positive
photosensitive resin composition, it is preferred to employ one
comprising a curing agent and carry out heating after development,
for the strength of the formed yellow filter layer is improved. The
yellow filter layer may be formed after the other color filter
layers have been provided on the substrate.
[0083] Thus, a color filter array constituted of the yellow filter
layer, magenta filter layer, and cyan filter layer that are formed
so as to be adjoining to each other in the same plane of the
substrate can be obtained.
[0084] The color filter array thus obtained is used for a
solid-state image device, a liquid crystal display device, and the
like. For instance, in the solid-state image device, if the color
filter array is disposed on the front side of its charge-coupled
device, color images excellent in color reproductivity can be
obtained.
[0085] The color filter array of the present invention shows
excellent spectroscopic characteristics and has a yellow filter
layer excellent in light fastness. Moreover; since dyes are
employed as its colorants, a yellow filter layer less in foreign
matter content, and uniform in thickness can be produced with ease.
This color filter array is favorably employed for use in a liquid
crystal display device or a solid-state image device comprising a
charge-coupled device.
[0086] Hereinafter, the present invention will be described in more
detail based on Examples, but these should by no means be construed
as defining the scope of the present invention.
EXAMPLE 1
[0087] After 36 parts by weight of C.I. Solvent Yellow 162 as the
dye (I), 27 parts by weight of the ester of a phenolic compound
represented by the chemical formula (10) with
o-naphthoquinonediazide-5-sulfonate, as the photoactive compound,
18 parts by weight of a novolak resin of p-cresol as the
alkali-soluble resin (weight average molecular weight in terms of
polystyrene: 6,000), 20 parts by weight of
hexamethoxymethylmelamine as the curing agent, and 400 parts by
weight of ethyl lactate as the solvent had been mixed and
dissolved, the resulting mixture was filtrated with a membrane
filter having a pore size of 0.1 .mu.m to provide a positive
photosensitive resin composition.
[0088] A coat was formed by applying the positive photosensitive
resin composition obtained above onto a substrate (silicon wafer)
by spin coating and heating at 100.degree. C. for 1 minute to
evaporate ethyl lactate therefrom. The coat had been exposed to
light by irradiation of i-ray through a mask pattern using an
exposure equipment ("Nikon NSR i7A" manufactured by Nikon Corp.).
Then, the pattern was developed by immersing the coated substrate
in a developer ("SOPD" manufactured by Sumitomo Chemical Co., Ltd.)
at 23.degree. C. for 1 minute. After the development, the substrate
was washed with water, dried, irradiated with ultraviolet rays, and
heated to 180.degree. C. for 3 minutes to give a color filter array
having a yellow filter layer in a striped-pattern (FIG. 4). The
yellow filter layer has a line width of 1.0 .mu.m and a thickness
of 0.7 .mu.m.
[0089] Thereafter, except using a different mask pattern, the same
procedure as above was repeated to give a color filter array having
a yellow filter layer formed in a mosaic pattern (FIG. 5). The
yellow filter layer has a line width of 2.0 .mu.m and a thickness
of 0.7 .mu.m.
[0090] Except that a transparent glass plate was employed as the
substrate in place of a silicon wafer and that the pattern was
developed without being exposed to light, the same procedure as
above was repeated to give a yellow filter layer formed in a
thickness of 0.7 .mu.L mall over the substrate.
EXAMPLE 2
[0091] Except for using 18 part by weight of C.I. Solvent Yellow
162 as the dye (I) and 18 part by weight of C.I. Solvent Yellow 82
as the other dye in place of 36 parts by weight of C.I. Solvent
Yellow 162, the same procedure as in Example 1 was repeated to give
a color filter array having a striped-pattern yellow filter layer
with a line width of 1.0 .mu.m and a thickness of 0.7 .mu.m (FIG.
4), a color filter array having a mosaic-pattern yellow filter
layer with a line width of 2.0 .mu.m and a thickness of 1.1 .mu.m,
and a yellow filter layer formed in a thickness of 1.1 .mu.m all
over the substrate.
EXAMPLE 3
[0092] After 18 part by weight of C.I. Solvent Yellow 162 as the
dye (I), 0.5 parts by weight of the compound represented by the
chemical formula (50): 8
[0093] as the photo acid generator, 44 parts by weight of a novolak
resin of p-cresol as the alkali-soluble resin (weight average
molecular weight in terms of polystyrene: 5,000), 20 parts by
weight of hexamethoxymethylmelamine as the curing agent, and 400
parts by weight of ethyl lactate as the solvent had been mixed and
dissolved, the resulting mixture was filtrated with a membrane
filter having a pore size of 0.1 .mu.m to provide a negative
photosensitive resin composition.
[0094] A coat was formed by applying the negative photosensitive
resin composition obtained above onto a substrate (silicon wafer)
by spin coating and heating at 100.degree. C. for 1 minute to
evaporate ethyl lactate therefrom. The coat had been exposed to
light by irradiation of i-ray through a mask pattern using an
exposure equipment ("Nikon NSR i7A" manufactured by Nikon Corp.),
followed by heated at 120.degree. C. for 1 minute. Then, the
pattern was developed by immersing the coated substrate in a
developer ("SOPD" manufactured by Sumitomo Chemical Co., Ltd.) at
23.degree. C. for 1 minute. After the development, the substrate
was washed with water, dried, irradiated with ultraviolet rays, and
heated to 180.degree. C. for 3 minutes to give a color filter array
having a yellow filter layer in a striped-pattern. The yellow
filter layer has a line width of 1.0 .mu.m and a thickness of 0.7
.mu.m.
[0095] Thereafter, except using a different mask pattern, the same
procedure as above was repeated to give a color filter array having
a yellow filter layer formed in a mosaic pattern. The yellow filter
layer has a line width of 2.0 .mu.m and a thickness of 0.7
.mu.m.
[0096] Except that a transparent glass plate was employed as the
substrate in place of a silicon wafer and that the exposure to
light was conducted without using the mask pattern, the same
procedure as in Example 1 was repeated to give a yellow filter
layer formed in a thickness of 0.7 ,am all over the substrate.
EXAMPLE 4
[0097] A photosensitive resin composition for forming a magenta
filter layer, a photosensitive resin composition for forming a cyan
filter layer, and a photosensitive resin composition for forming a
yellow filter layer were prepared according to the respective
blending formulations shown below.
1 (Photosensitive resin composition for forming a magenta filter
layer) Novolak resin 36 parts by weight
o-naphthoquinonediazide-4-sulfonate 30 parts by weight
Hexamethoxymethylmelamine 17 parts by weight Ethyl lactate 280
parts by weight N,N'-dimethylformamide 120 parts by weight A
compound represented by the chemical formula (51) 18 parts by
weight (51) 9 (Photosensitive resin composition for forming a cyan
filter layer) Novolak resin 19 parts by weight
o-naphthoquinonediazide-4-sulfonate ester 43 parts by weight
Hexamethoxymethylmelamine 16 parts by weight Ethyl lactate 210
parts by weight N,N'-dimethylformamide 90 parts by weight C.I.
Solvent Blue 67 23 parts by weight (Photosensitive resin
composition for forming a yellow filter layer) Novolak resin 18
parts by weight o-naphthoquinonediazide-4-su- lfonate ester 27
parts by weight Hexamethoxymethylmelamine 20 parts by weight Ethyl
lactate 280 parts by weight N,N'-dimethylformamide 120 parts by
weight C.I. Solvent Yellow 162 18 parts by weight C.I. Solvent
Yellow 82 18 parts by weight
[0098] The photosensitive resin composition for forming a yellow
filter layer prepared above had been applied onto a silicon wafer
provided with a charge-coupled device by spin coating. Then, its
solvent was evaporated off on a baking plate at 100.degree. C.
[0099] Thereafter, using an i-ray stepper exposure equipment
("Nikon NSR2205 il2D" manufactured by Nikon Corp.), the substrate
was irradiated with an ultraviolet ray of a wavelength of 365 nm
through a reticle (2,000 mJ/cm.sup.2). Then, the substrate was
subjected to development by a developing agent (an aqueous solution
containing 30 g of tetramethylammonium hydroxide per 1,000
cm.sup.3). After the exposed portion had been removed, the
substrate was washed with pure water. Thereafter, using a
low-pressure mercury lamp (3,000 mJ/cm.sup.2), ultraviolet rays
were irradiated all over the substrate, and the substrate was then
heated on a baking plate at 180.degree. C. for 10 minutes to form a
yellow filter layer.
[0100] Except for using the photosensitive resin composition for
forming a magenta filter layer prepared above instead of the
photosensitive resin composition for forming a yellow filter layer,
the same procedure as above was repeated to form a magenta filter
layer (FIG. 6(b)).
[0101] Except for using the photosensitive resin composition for
forming a cyan filter layer prepared above, the same procedure as
above was repeated to form a cyan filter layer and consequently a
color filter array.
[0102] A microlens was formed on the color filter array in a
conventional manner to give a solid-state image device. The
thickness of the yellow filter layer of the color filter array at
the solid-state image device was 0.7 .mu.m. The color filter array
at this solid-state image device showed good spectroscopic
characteristics.
[0103] In the same manner as that described above, a yellow filter
layer (thickness: 0.7 .mu.m) was formed all over a quartz
wafer.
COMPARATIVE EXAMPLE 1
[0104] Except for using 20 of parts by weight of the compound
represented by the chemical formula (52): 10
[0105] wherein R.sup.50 represent a group represented by the
following formula (53): 11
[0106] 10 of parts by weight of the compound represented by the
chemical formula (54): 12
[0107] wherein R.sup.51 represent a group represented by the
following formula (55): 13
[0108] 6 of parts by weight of the compound represented by the
chemical formula (56): 14
[0109] wherein R.sup.52 represent a group represented by the
formula (55)
[0110] in place of C.I. Solvent Yellow 162, the same procedure as
in Example 1 was repeated to give a color filter array having a
striped-pattern yellow filter layer with a line width of 1.0 .mu.m
and a thickness of 1.1 .mu.m, a color filter array having a
mosaic-pattern yellow filter layer with a line width of 2.0 .mu.m
and a thickness of 1.1 .mu.m, and a yellow filter layer formed in a
thickness of 1.1 am all over the substrate.
[0111] Evaluation
[0112] (1) Exposure Time
[0113] The exposure time required to form lines of 1.0 .mu.m in
each of Examples and Comparative Example is shown in Table 1.
[0114] (2) Spectroscopic Characteristics
[0115] The color filter arrays each provided with a yellow filter
layer all over its substrate and obtained in Examples and
Comparative Example were subjected to measurement of light
transmittance at 450 nm, 535 nm, and 650 nm. The results are shown
in Table 2.
[0116] (2) Light Fastness
[0117] An ultraviolet ray-blocking filter ("colored optical glass
L38" manufactured by Hoya Corp. Capable of blocking light of a
wavelength of 380 nm or shorter) was disposed in front of each of
the color filter arrays obtained in Examples and Comparative
Example and provided with a yellow filter layer all over its
substrate, followed by irradiating light at 1,000,000
1x.multidot.hour. "Sun tester XF 180 CPS" manufactured by Shimadzu
Corp. was employed as the light source. The light transmittance of
each color filter array after the irradiation was measured at a
wavelength of 450 nm, 535 nm, and 650 nm. The results are shown in
Table 3.
2 TABLE 1 Exposure time (msec) Example 1 400 Example 2 600 Example
3 250 Comparative 2000 example 1
[0118]
3 TABLE 2 Light transmittance (%) Wavelength 450 535 650 (nm)
Example 1 0.2 95 100 Example 2 0.6 84 98 Example 3 0.5 95 100
Comparative 7 93 98 example 1
[0119]
4 TABLE 3 Light transmittance (%) Wavelength 450 535 650 (nm)
Example 1 2 98 100 Example 2 2 87 100 Example 3 5 98 100
Comparative 19 94 99 example 1
* * * * *