JP2002107531A - Color filter and color image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the roughening of an image picked up with a color image pickup device as well as to improve the heat and light resistances of a color filter and to obtain an image having good color forming property. SOLUTION: The color image pickup device contains plural photoelectric converting elements arrayed on a two-dimensional flat surface and a cyan color filter disposed on the elements. The color filter contains a transparent resin and fine particles of a pigment containing aluminum phthalocyanine, titanium phthalocyanine, cobalt phthalocyanine or tin phthalocyanine dispersed in the transparent resin and has a high relative sensitivity region from 470 nm to 540 nm wavelength and a low relative sensitivity region in which relative sensitivity from 625 nm to 650 nm wavelength is about <=10% of the maximum sensitivity in the high relative sensitivity region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image sensor, and more particularly, to a color filter used in a color image sensor.

[0002]

2. Description of the Related Art In the present specification, complementary color filters include color filters of cyan, magenta, and yellow. The primary color filters include color filters such as green, red, and blue.

[0003] In recent years, there has been an increasing demand for higher pixel density in color imaging devices. Since a complementary color filter having a high spectral transmittance is bright, it is suitable for a higher pixel density than a primary color filter. For example, magenta (Magenta: Mg), yellow (Yellow:
By forming a color filter in which a pattern colored in a complementary color such as Ye) or cyan (Cyan: Cy) is accurately arranged and arranged on a photoelectric conversion element, a color image with high resolution can be obtained.

[0004] As a method of producing a color filter by coloring a transparent resin, a dyeing method has conventionally been used. In the dyeing method, for example, a substrate colored with a dye such as gelatin is applied on a substrate of a CCD solid-state imaging device, and the substrate is processed to form a color filter pattern. Alternatively, there is a method of dyeing a pattern formed of a transparent substrate with a dye, and a method of forming a pattern after coloring a transparent substrate. After forming a protective film thereon, a color filter of another color is formed.

[0005]

However, color filters using dyes have problems in heat resistance and light resistance.
Although the problem of heat resistance and light resistance has been covered to some extent by forming the protective film, sufficient heat resistance and light resistance cannot be obtained. In addition, there is also a problem that the number of steps increases because a protective film forming step must be added.

Therefore, while improving heat resistance and light resistance,
As a method that can omit the formation of the protective film, a coloring method using a pigment is being studied. Pigments are chemically more stable than dyes and should improve the heat resistance and light resistance of the color filters.

However, when an image captured by a color image sensor using a color filter formed by a pigment coloring method is displayed on a display monitor, the image is likely to be rough. Further, the color reproducibility of the displayed image is not very good.

The present invention improves the heat resistance and light resistance of a color filter used in a color image pickup device,
Reduces the roughness of the image captured by the color image sensor,
Another object is to obtain an image with good color reproducibility.

[0009]

According to one aspect of the present invention, there is provided a color imaging device including a plurality of photoelectric conversion elements arranged on a two-dimensional plane and a cyan color filter disposed thereon. The color filter comprises a transparent resin and fine particles of a pigment dispersed in the transparent resin and containing at least one of aluminum phthalocyanine, titanium phthalocyanine, cobalt phthalocyanine, and tin phthalocyanine.
A color imaging device having a high relative sensitivity region at 0 nm and a low relative sensitivity region having a relative sensitivity from 625 nm to 650 nm of about 10% or less of the highest sensitivity in the high relative sensitivity region is provided.

When a cyan color filter formed by dispersing fine particles of a phthalocyanine pigment of aluminum, titanium, cobalt or tin in a transparent resin is used, a wavelength of 4
A high relative sensitivity is obtained from 70 nm to a wavelength of 540 nm, and a relative sensitivity from a wavelength of 625 nm to 650 nm is 10% or less of the maximum sensitivity, the spectral sensitivity of cyan is improved, and the noise / sensitivity ratio of the complementary color signal of cyan is improved. Reduce. Therefore, roughness of an image captured using the color image sensor can be suppressed.

According to another aspect of the present invention, there is provided a cyan color filter used for a color image sensor, comprising a transparent resin, and aluminum phthalocyanine, titanium phthalocyanine, cobalt phthalocyanine, or tin phthalocyanine dispersed in the transparent resin. A color filter having a high transmittance of 50% or more from 400 nm to 570 nm and a low spectral transmittance of 10% or less from 625 nm to 650 nm. Is provided.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing embodiments of the present invention, considerations made by the inventor will be described. When a complementary color filter is used, signal processing involving a matrix operation is performed to extract a primary color signal from the complementary color signal. Heretofore, it has not been possible to obtain a pigment of a complementary color, particularly a cyan pigment, having a very good spectral characteristic. Therefore, in order to improve color reproducibility, it is necessary to perform signal processing including matrix operation processing including large subtraction.

However, when a matrix operation including a large subtraction is performed, the noise / sensitivity ratio of the obtained primary color signal also increases. In order to obtain a good image, it is preferable that the noise / sensitivity ratio of the complementary color signal be as small as possible and that the spectral characteristics of the complementary color filter be as good as possible.

A matrix operation including a large subtraction
Processing means "includes negative coefficients with large absolute values."
Taste is a big difference when noise / sensitivity ratio
It may cause it to grow. For example, in the case of addition, N
_total/ S_total= (N₁ ^Two+ N _Two ^Two)^0.5/ (S₁+ S_Two)so
is there. N for subtraction_total/ S_total= (N₁ ^Two+
N_Two ^Two)^0.5/ (S₁-S_Two).

The inventor of the present invention has concluded that, when a color filter colored with a pigment is used, the noise of the primary color signal becomes large and the image becomes rough, because the pigment mixed into the transparent resin may have a problem. Thought.

The size of a photoelectric conversion element included in a solid-state imaging device has been rapidly reduced. When a pigment is mixed into a transparent resist, mixing large pigment particles having a particle size substantially equal to the size of the photoelectric conversion element causes roughness of an image. Even if the pigment particles have a small particle size before being mixed into the transparent resin, if the pigment particles aggregate during the process of mixing the pigment, the substantial particle size of the pigment particles becomes large, and the image becomes rough. Therefore, when dispersing the pigment particles in the transparent resin, it is necessary to prevent the substantial size thereof from increasing.

In addition, in order not to make the matrix value used for forming the primary color signal from the complementary color signal so large, the spectral characteristics of the complementary color filter should be as good as possible. desirable.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3 based on the above considerations.

FIG. 1 shows a chemical formula of metal phthalocyanine used for a cyan complementary color filter. As shown in FIG. 1, the metal atom M is located at the center, and the properties of the metal phthalocyanine change depending on the type of the metal atom M. The metal atom is preferably aluminum, titanium, cobalt or tin.

FIG. 2 shows a structure of a cyan color filter in which fine particles of an aluminum phthalocyanine pigment are dispersed in a transparent resin. As shown in FIG. 2, the cyan color filter 1 includes a transparent resin (including a photoresist or the like) 3 and
And fine particles 5 of an aluminum phthalocyanine pigment.

The fine particles 5 of the aluminum phthalocyanine pigment are dispersed in the transparent resin 3. The thickness of the transparent resin 3 is, for example, between 0.2 μm and 5 μm, and preferably between 1 μm and 2 μm. When the size of the photoelectric conversion element is reduced due to an increase in pixel density, it is preferable to reduce the thickness of the color filter in view of the aspect ratio.

In order to prevent irregularities on the surface of the transparent resin, it is necessary to make the particle size of the fine particles 5 of the aluminum phthalocyanine pigment smaller than the thickness of the transparent resin 3. It is preferable not to protrude from the upper and lower surfaces of the transparent resin.
The particle size of the fine particles 5 of the aluminum phthalocyanine pigment is
For example, it is preferably 1 μm or less, more preferably 0.1 μm or less. The volume ratio of the fine particles 5 of the aluminum phthalocyanine pigment to the transparent resin 3 per unit volume is, for example, the fine particles 5 of the aluminum phthalocyanine pigment.
Occupies about 25% to 70%.

FIG. 3 shows the wavelength dependence of the transmittance of a cyan color filter in which fine particles of the above-mentioned aluminum phthalocyanine pigment are dispersed in a transparent resin.

The average particle size of the fine particles of the aluminum phthalocyanine pigment is 0.04 μm.

As shown in FIG. 3, a cyan color filter in which fine particles of aluminum aluminum phthalocyanine pigment are dispersed in a transparent resin has a wavelength of 400 nm to 600 nm.
It has high transmittance over the range up to nm. More specifically, it has a high transmittance of 50% or more from a wavelength of 400 nm to a wavelength of 570 nm and a wavelength of 62 nm.
It has a low spectral transmittance of 10% or less from 5 nm to a wavelength of 650 nm.

FIG. 3 also shows data of PG7, which is generally used as a pigment for a cyan filter, for comparison. The color filter using PG7 is
The transmittance of light from a wavelength of 400 nm to a wavelength of 500 nm is smaller than that of a cyan color filter, and the transmittance at a wavelength of 600 nm or more exceeds 15%.

From the results shown in FIG. 3, it can be seen that, when the fine particles of aluminum phthalocyanine pigment are used, the transmittance in the blue region is improved and the transmittance in the red region can be extremely reduced as compared with the case where PG-7 is used. Shows excellent spectral characteristics as a filter.

As pigments for cyan color filters, in addition to aluminum phthalocyanine pigment fine particles dispersed in a transparent resin, titanium phthalocyanine (also known as:
It is also possible to use fine particles of a titanium phthalocyanine pigment, fine particles of a cobalt phthalocyanine pigment, or fine particles of a tin phthalocyanine pigment.

The following pigments can be used as pigments for complementary color filters other than cyan.

Various pigments can be used as the pigment for the yellow (Ye) color filter. PY (P
pigment Yellow) 83, PY129, PY
138, PY139, PY150 and PY185 are preferred. One of the above pigments may be used alone, or two or more of them may be used in combination. Alternatively, a solid solution of two or more pigments may be used.

Pigments for magenta (Mg) color filters include PR (Pigment Red) 81, PR1
22, PR144, PR146, PR169 or PR1
77, PV (Pigment Violet) 19 or PV23 is preferably used. One type may be used, or two or more types may be used in combination. Alternatively, a solid solution of two or more pigments may be used.

As a pigment for a green (G) primary color filter which is often used together with a complementary color filter, a mixture of the above-mentioned yellow pigment and the following green or cyan pigments is preferably used. As the green pigment, PG7 or PG36 is preferably used. As the cyan pigment, aluminum phthalocyanine, titanium phthalocyanine, cobalt phthalocyanine, or tin phthalocyanine is preferable. Each of the yellow pigment and the green pigment or the cyan pigment may be a mixture of two or more kinds. Further, a solid solution may be used.

FIG. 4 is a plan view of a honeycomb CCD color image pickup device. 5A to 5C are cross-sectional views illustrating the steps of manufacturing the honeycomb CCD color imaging device.

As shown in FIG. 4, in the honeycomb CCD color imaging device X, a large number of photoelectric conversion elements 7 are arranged in a plurality of columns and a plurality of rows at a constant pitch on a two-dimensional plane formed by the surface of a semiconductor substrate 6. It is arranged over. The photoelectric conversion elements 7 are arranged in the column direction to form one photoelectric conversion element row.
The photoelectric conversion elements 7 are arranged in a row direction to form one photoelectric conversion element row. A read gate 7a for reading electric charges in the direction of the arrow is formed adjacent to the photoelectric conversion element 7.

Each of the plurality of photoelectric conversion elements forming one photoelectric conversion element column is approximately one in the column direction with respect to the photoelectric conversion element forming the photoelectric conversion element row adjacent thereto in the row direction. / 2 pitch shift. Each of the plurality of photoelectric conversion elements forming one photoelectric conversion element row is approximately 約 pitch in the row direction with respect to the photoelectric conversion elements forming the photoelectric conversion element row adjacent thereto in the column direction. It is out of alignment.

A plurality of vertical charge transfer channels 21 are formed in order to transfer the signal charges accumulated in each photoelectric conversion element 7, and each of the vertical charge transfer channels 21 is arranged adjacent to each other in the row direction. It extends in the column direction, meandering between the columns. The vertical charge transfer channel layer 21 is, for example, an n-type semiconductor layer formed on the semiconductor substrate 6.

On the vertical charge transfer channel 21, a plurality of first vertical charge transfer electrodes 27a extending in the horizontal direction are provided.
And a second vertical charge transfer electrode 2 adjacent thereto in the column direction.
7b is formed to meander. The first vertical charge transfer electrode 27a and the second vertical charge transfer electrode 27b are formed in line symmetry with respect to a straight line extending in the row direction, and the first vertical charge transfer electrode 27a and the second vertical charge The transfer electrodes 27b form a set, and are repeatedly formed in the row direction of a large number of sets. One set of vertical charge transfer electrodes 27
a, a substantially hexagonal gap formed between 27b and
Each of the photoelectric conversion elements 7 is located in each of the substantially hexagonal gaps formed between the vertical charge transfer electrodes 27b and 27a.

As described above, the pixel density can be improved by forming a large number of photoelectric conversion elements 7 and a plurality of charge transfer electrodes in a honeycomb shape.

The vertical charge transfer channel 21 protrudes from the photoelectric conversion element array. At one end of the vertical charge transfer channel 21, a horizontal charge transfer channel 53 connected thereto is formed. From the position of the vertical charge transfer channel 21 projecting from the photoelectric conversion element row, the horizontal charge transfer channel 53
Are formed adjacent to each other in the vertical direction between the charge transfer electrodes 32-1 to 32-5 extending in the horizontal direction. Charge transfer electrodes 32-4 and 32-5
And are commonly connected. A first barrier layer B1 (hatched) is formed of a low-concentration n-type semiconductor layer or a p-type semiconductor layer in the semiconductor layer below the charge transfer electrode 32-4.

A horizontal charge transfer channel 53 is formed adjacent to the final charge transfer electrode 32-5 in the vertical direction and along the horizontal direction. An output amplifier 61 is formed at one end of the horizontal charge transfer channel 53. The horizontal charge transfer channel 53 includes a high-concentration n-type semiconductor layer 53a.
And a low-concentration n-type semiconductor layer 53b. A plurality of high-concentration n-type semiconductor layers 53a are formed in an island-like region,
Each is close to and opposite one end of a single vertical charge transfer channel 21. Low concentration n-type semiconductor layer 53b
Has a region extending in the horizontal direction so as to be adjacent to one end of at least a plurality of, for example, all the vertical charge transfer channels 21, and a plurality of branch portions branched from the region extending in the horizontal direction. Each of the branched portions extends in the vertical direction so as to divide the high-concentration n-type semiconductor layer 53a adjacent in the horizontal direction. The low-concentration n-type semiconductor layer 55b forms a second barrier layer B2 (shaded portion). A p-type semiconductor layer may be used instead of the low-concentration n-type semiconductor layer.

An island-shaped first horizontal charge transfer electrode 55a formed on the high-concentration n-type semiconductor layer 53a and a low-concentration n-type
The second horizontal charge transfer electrodes 55b formed on the mold semiconductor layer 53b are alternately arranged in the horizontal direction. The horizontal charge transfer electrodes 55a-1, 55b-1, 55a-2, 5
They are arranged in the horizontal direction in the order of 5b-2. The first horizontal charge transfer electrodes 55a-1 to 55a-8 and the second horizontal charge transfer electrodes 55b-1 to 55b-8 constitute one set, and a plurality of these sets are arranged. Horizontal charge transfer electrodes adjacent in the horizontal direction, for example, horizontal charge transfer electrodes 5
5a-1 and 55b-1 are commonly connected to form a two-phase drivable electrode group. However, in this configuration,
Eight drive signal supply lines are provided for one set. In the figure, voltages from φH1 to φH8 can be applied in order from the left side.

FIG. 5 is a sectional view taken along the line VV 'of FIG.
FIG. 5C is a cross-sectional view of the color imaging device.
Steps up to FIG. 5C will be described with reference to FIGS.

As shown in FIG. 5A, a p-type semiconductor layer 15 is formed on a semiconductor substrate 6. In the p-type semiconductor layer 15,
An n-type semiconductor layer 17 constituting the photoelectric conversion element (photodiode) 7 is formed together with the p-type semiconductor layer 15. A vertical charge transfer channel 21 is formed near the n-type semiconductor layer 17 by the n-type semiconductor layer. A read gate 7a is formed between the two. A channel stopper layer 23 is formed outside the n-type semiconductor layer 17 and the vertical charge transfer channel 21 with a p-type semiconductor layer having a high impurity concentration.

A gate oxide film 25 is formed on the p-type semiconductor layer 15. On the gate oxide film 25 and on the region above the vertical charge transfer channel layer 23, the charge transfer electrodes 27a,
7b is formed of polycrystalline silicon. Charge transfer electrode 2
An insulating film 25a is also formed on the insulating films 7a and 27b. An opening exposing the insulating film 25 on the surface of the n-type semiconductor layer 17 forming a part of the photoelectric conversion element 7 is formed on the insulating film 25a. A light-shielding film 31 that covers the vertical charge transfer channel layer 23 and the vertical charge transfer channel layers 23 is formed. A planarizing film 30 is formed to cover the above structure.

As shown in FIG. 5B, a color filter including a cyan color filter 33 is formed on a region corresponding to each photoelectric conversion element 7 on the flattening film 30. FIG. 5B shows a yellow color filter 25 and a magenta color filter 37 in addition to the cyan color filter 33. The arrangement of the color filters is as follows.
For example, the arrangement is as shown in FIG. 4 and has four color arrangements of cyan Cy, yellow Ye, magenta Mg, and green G. The filter arrangement of the four colors is not limited to the arrangement of FIG. Any filter arrangement is within the scope of the present invention, and the effects of the invention can be exhibited.

A row in which cyan and magenta are alternately arranged and a row in which green and yellow are alternately arranged are alternately arranged in the direction.

The manufacturing process of the color filter will be described in detail. After the flattening film 30 is formed, a color filter of the first color is formed, and then a color filter of the second, third, and fourth colors is formed. The process of forming a color filter of each color includes first applying a color resist film of each color to the substrate surface, passing through a first baking process, performing exposure and development for pattern formation, and then performing a second baking process. Do.

The color resist film is applied by a spin coater, a spray coater, a roll coater or the like. The film thickness to be applied is, for example, from 0.2 μm to 5 μm, preferably from 1 μm to 2 μm.

In the exposure step for forming a pattern, the exposure mask and the substrate surface are brought into a non-contact state or a contact state.
Light irradiation is performed using an i-line, an h-line, a g-line, or an excimer laser. Development step, the exposed substrate in an alkaline developer, for example, in an aqueous solution containing sodium carbonate or caustic soda,
Alternatively, it is immersed in an organic solvent (dimethylbenzylamine, triethanolamine, etc.). An aqueous solution or an organic solvent may be sprayed with a spray or the like. Incidentally, an antifoaming agent or a surfactant may be added to the developer.

Cyan Cy, Yellow Ye, Magenta M
When forming four color filters of g and green G, color filters of Ye, Mg, Cy, and G are formed in an arbitrary order.

Also, three color filters of yellow Ye, cyan Cy, and magenta Mg can be used.
In this case, it is preferable that the yellow Ye color filter occupies １ ／ of the entire area and the other color filters occupy １ ／ of the entire area. The reason is that not only the G signal but also the R signal resolution is improved.

Next, as shown in FIG. 5C, a flattening film 40 is formed on the color filters 33, 35 and 37 to reduce surface irregularities due to the color filters. Flattening film 4
The microlens 41 for condensing the light on the opening 18 of the photoelectric conversion element 7 on the area corresponding to each photoelectric conversion element 7
To form

Through the above steps, a honeycomb CCD color image pickup device having a complementary color filter is completed.

The operation of the honeycomb CCD color image pickup device will be described with reference to FIGS. A read pulse is applied to the first vertical charge transfer electrode 27a and the second vertical charge transfer electrode 27b. At this time, no read pulse is applied to the first and second vertical charge transfer electrodes of the next row vertically adjacent to the first and second vertical charge transfer electrodes 27a and 27b. That is, 1/2 thinning-out reading is performed.

When a read pulse is applied to the first vertical charge transfer electrode 27a, charges of green G, yellow Ye, green G, and yellow Ye are transferred from the photoelectric conversion element 7 to the vertical charge transfer channel 21 through the read gate 7a. Is done. When a read pulse is applied to the second vertical charge transfer electrode 27b, charges of cyan Cy, magenta Mg, cyan Cy, and magenta Mg are transferred from the photoelectric conversion element 7 to the vertical charge transfer channel 21 through the read gate 7a.

A voltage for transferring the charges in the vertical charge transfer channel 21 to the horizontal charge transfer channel 53 is sequentially applied to the vertical charge transfer electrodes 27a and 27b. The charges are transferred in the direction of the horizontal charge transfer channel layer 53. Charge transfer electrodes 32-1, 32-2, 32-3,
When a High voltage is sequentially applied to 32-4 (common to 32-5) to transfer charges in the direction of the horizontal charge transfer channel 53, for example, a charge C below the charge transfer electrode 32-5
The charge of y, Mg, Cy, Mg is accumulated. Once these charges are transferred below the charge transfer electrode 32-5,
Due to the presence of the first barrier layer B1 formed below the charge transfer electrode 32-4, charges do not return in the direction opposite to the horizontal charge transfer channel layer 53.

Here, φ4 is set to Low, for example, φH
When 5 is set to High, the charge (Cy) accumulated under the charge transfer electrode 32-5 is changed to the horizontal charge transfer electrode 53a-.
5 and enters the high-concentration n-type semiconductor layer 53a. Next, φ4
When φH4 is set to High while is set to Low, the charge (Cy) is reduced to a high concentration n-type semiconductor layer 53 under 55a-4.
a. Thus, the charge (Cy) is transferred to the high-concentration n-type semiconductor layer 53 under the horizontal charge transfer electrode 55a-2.
Transfer to a.

Next, when φH1 is set to High while φ4 is set to Low, the charge (C) transferred to the high-concentration n-type semiconductor layer 53a under the horizontal charge transfer electrode 55a-2.
y) and the vertical charge transfer channel layer 21 under the transfer electrode 32-5 vertically facing the horizontal charge transfer electrode 55a-1.
And the electric charge (Cy) accumulated therein enters the region below 53a-1, and the electric charge (Cy) is added. By the same operation, the charge of Mg or Ye can be added. Ye,
Since the charges of Mg, Cy and G can be added, a brighter image can be obtained.

FIG. 6 shows a spectral sensitivity characteristic when a digital still camera is manufactured using a color image pickup device including a cyan complementary color filter according to the present embodiment. In addition, the spectral sensitivity characteristics when PG7 is used as a color pigment for a color filter is shown as a comparative example. When the cyan complementary color filter according to the present embodiment is used, it has high sensitivity from a wavelength of 400 nm to a wavelength of 600 nm, and has extremely low sensitivity in a region where the wavelength exceeds 600 nm. It turns out that it has excellent spectral sensitivity characteristics.

More specifically, a wavelength of 470 nm to a wavelength of 5
It has a high relative sensitivity region over 40 nm,
The relative sensitivity from the wavelength of 625 nm to the wavelength of 650 nm has a low relative sensitivity region of about 10% of the highest sensitivity in the high relative sensitivity region.

On the other hand, when the color filter according to the comparative example is used, the sensitivity from 400 nm to 470 nm is low, and the wavelength is from 600 nm to 650 nm.
The sensitivity toward m is higher, and the color filter according to the present embodiment has better spectral sensitivity characteristics as a cyan complementary color filter.

Actually, the same image is taken when the color filter according to the present embodiment is used and when the color filter according to the comparative example is used, so that the linear matrix and the linear matrix are arranged so that the color reproducibility is substantially equal. The color difference matrix was determined and signal processing was performed to create an image. When the images of the color image sensor using the color filter according to the present embodiment and the color image sensor using the color filter according to the comparative example are compared, the image photographed by the color image sensor according to the present embodiment is rougher. Was few.

The roughness of the image is determined by Macbethch
An art (Macbeth chart) was photographed, and roughness was visually evaluated for each color.

The reason why the roughness of the image is reduced is that, first, fine particles of the pigment are dispersed in the transparent resin, so that the noise of the color signal is reduced as compared with the case where large pigment particles are mixed. Wavelength 400nm to 600n
m, the light transmittance of the color filter is high, and
Since the light transmittance of the color filter at a wavelength of 600 nm or more is extremely low, the value of the linear matrix itself for converting a complementary color signal into a primary color signal in the signal processing process may be small. If the linear matrix used for signal processing is small, the noise included in the signal after the matrix processing does not increase, so that the noise included in the finally obtained signal can be reduced.

When the color imaging device according to the present embodiment is used, the spectral sensitivity characteristic of the cyan complementary color filter is particularly improved as compared with the conventional color imaging device. Since it is not necessary to perform matrix processing using a very large matrix in the process of color signal processing, image roughness is reduced.

Further, since a pigment is used as a colorant for a color filter, heat resistance and light resistance are improved. Since the step of forming a protective film, which is required when a dye is used as a colorant, becomes unnecessary, the manufacturing process is also shortened.

[0067]

The use of the color image pickup device of the present invention improves the heat resistance and light resistance of the color filter. Roughness of the image is reduced as compared with the case where a conventional cyan pigment is used. In addition, since the dyeing process is not required, the manufacturing process can be simplified, the cost can be reduced, and the product yield can be improved.

[Brief description of the drawings]

FIG. 1 is a chemical formula of metal phthalocyanine used as a coloring pigment of a color filter used in a color imaging device according to the present embodiment.

FIG. 2 is a cross-sectional view illustrating a schematic structure of a color filter used in the color imaging device according to the present embodiment.

FIG. 3 is a diagram illustrating a spectral transmittance of a color filter used in a color imaging device according to an embodiment of the present invention, and also a diagram illustrating a spectral transmittance of a color filter according to a comparative example.

FIG. 4 is a plan view showing the structure of the color imaging device according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a manufacturing process of the color imaging device according to the present embodiment.

FIG. 6 is a diagram illustrating the spectral sensitivity characteristics of a digital camera using the color imaging device according to the embodiment of the present invention, and also illustrates the spectral sensitivity characteristics according to a comparative example.

[Explanation of symbols]

 Reference Signs List 1 color filter 3 transparent resin 5 aluminum phthalocyanine pigment fine particles 6 semiconductor substrate 7 photoelectric conversion element 11 n-type semiconductor layer 15 p-type semiconductor layer 17 n-type semiconductor layer 18 opening 21 vertical charge transfer channel layer (n-type semiconductor layer) 23) Channel stop 25, 25a Insulating film 27a, 27b Vertical charge transfer electrode (polycrystalline silicon) 30 Flattening film 31 Light shielding film 32 Transfer electrode 33, 35, 37 Color filter 40 Flattening film 41 Microlens 51 Horizontal charge transfer channel 53a High-concentration n-type semiconductor layer 53b Low-concentration n-type semiconductor layer 55a, 55b Horizontal charge transfer electrode 61 Output amplifier G Green Mg Magenta Ye Yellow Cy Cyan

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H048 BA45 BA47 BB02 BB07 BB10 BB47 4M118 AA10 AB01 BA13 CA03 GC08 GC14 GC20 5C065 AA01 AA03 BB15 CC01 DD02 DD17 EE05 EE07

Claims (6)

[Claims] 1. A color imaging device including a plurality of photoelectric conversion elements arranged on a two-dimensional plane and a cyan color filter disposed thereon, wherein the color filter comprises: a transparent resin; And fine particles of a pigment containing at least one of aluminum phthalocyanine, titanium phthalocyanine, cobalt phthalocyanine, and tin phthalocyanine dispersed in a resin, and having a high relative sensitivity region from 470 nm to 540 nm, and having a wavelength of 625 nm to 65
A color imaging device having a low relative sensitivity region in which the relative sensitivity toward 0 nm is about 10% or less of the highest sensitivity in the high relative sensitivity region. 2. The color imaging device according to claim 1, wherein the average particle size of the fine particles is 1 μm or less. 3. The color imaging device according to claim 1, wherein the fine particles have an average particle size of 0.1 μm or less. 4. A PY83, PY129, PY129, PY129, PY129, and PY83 layer formed on a second photoelectric conversion element different from the first photoelectric conversion element among the plurality of photoelectric conversion elements.
A yellow color filter in which fine particles of a yellow pigment containing at least one of Y138, PY139, PY150, and PY185 are dispersed;
Is formed on a third photoelectric conversion element different from the photoelectric conversion element of the above, and PR81, PR122, PR144,
PR146, PR169, PR177, PV19 or PV
And a magenta color filter in which fine particles of a magenta pigment containing at least any one of 23 are dispersed. 4. The color imaging device according to claim 1, further comprising: 5. A PY83, PY129, PY138, and PY13 formed on a fourth photoelectric conversion element different from the first to third photoelectric conversion elements and in a transparent resin.
9, green pigment fine particles formed by mixing at least one of PY150 and PY185 with at least one of PG7, PG36, aluminum phthalocyanine pigment, titanium phthalocyanine pigment, cobalt phthalocyanine pigment, or tin phthalocyanine pigment The color imaging device according to claim 4, further comprising: a green color filter in which is dispersed. 6. A cyan color filter for use in a color image sensor, comprising: a transparent resin; and an aluminum phthalocyanine dispersed in the transparent resin.
Pigment fine particles containing at least one of titanium phthalocyanine, cobalt phthalocyanine, and tin phthalocyanine, and having a high spectral transmittance of 50% or more from a wavelength of 400 nm to a wavelength of 570 nm and a 10% wavelength of 625 nm to a wavelength of 650 nm. A color filter having the following low spectral transmittance.