JP2001021715A - Color filter and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a flat filter surface by effectively preventing separation of a colored pattern film without lowering of sensitivity and uneven sensitivity. SOLUTION: This color filter 30 is formed by red, green and blue colored pattern films 32, 34, 36. The respective unit cells 34A of the green colored pattern 34 are arranged like checkers in a picture element matrix. In the colored pattern 34, the unit cells 34A are connected diagonally by a bridging part 34B to improve the adhesiveness of each corner part of each unit cell 34A, whereby separation can be prevented. The unit cells of the red and blue colored patterns 32, 36 are line-sequentially arranged and formed in an area surrounded with each unit cell 34A and bridging part 34B of the colored pattern 34. The corner parts of the unit cell are cut not to overlap the bridging part 34B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color filter in which a colored pattern film is adhered to a light emitting surface and a light receiving surface of various optical devices, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Heretofore, as a solid-state imaging device used in a color video camera, a color still camera, or the like, a device in which a primary color or a complementary color filter is arranged on a surface of a light receiving element constituting each pixel has been provided. ing. In this solid-state imaging device, a flattening film is stacked on the surface of a device having irregularities with a light receiving element and a signal charge transfer register stacked on a semiconductor substrate, and a color filter is coated on the flattening film. It is to be formed. Further, a microlens is further disposed on the upper surface of the color filter via an adhesive layer.

FIG. 5 is a sectional view showing an element structure in a solid-state imaging device provided with a conventional color filter. In the figure, a light receiving element 112 composed of a photodiode or the like, a transfer register unit 14 using a CCD, and the like are formed in a semiconductor substrate 110. An insulating film 116 is provided on the upper surface of the semiconductor substrate 110, and a transfer electrode 118 corresponding to the transfer register unit 114 is provided via the insulating film 116. In addition, a light-shielding film 120 that shields a portion other than the light-receiving region of the light-receiving element 112 is provided on the upper surface of the insulating film 116, and the passivation film 122 is formed on the upper surface so as to cover the entire semiconductor substrate 110.
Is provided.

[0004] A flattening film 124 is provided on the upper surface of the passivation film 122.
The color filter 130 is provided on the flat upper surface of the fourth. The color filter 130 of the present example has RGB (red,
Green, blue) colored pattern film 132 of three primary colors,
134 and 136. Further, a micro lens 142 made of a transparent resin film 140 is provided on the color filter 130.

In general, as the flattening film 124, a photo-setting resin such as an acrylic resin or a thermosetting resin such as a polyimide resin can be used. Also, color filter 1
As a colored pattern film constituting 30, a dyeing method for dyeing an organic film such as casein or gelatin, or a color resist using a photosensitive resin composition in which a pigment having a predetermined particle size distribution and an insoluble dye are dispersed in a resin. Those formed by the method are known.

[0006]

In the solid-state imaging device as described above, the size and the number of pixels have been reduced, and when the color pattern of the color filter is miniaturized, the color pattern film may be peeled off. Defects due to separation and the like are increasing, and the adhesion between the flattening film and the colored pattern film is generally poor in many cases. Therefore, it is required to improve the adhesion between the flattening film and the colored pattern film. However, when the adhesion between the flattening film and the colored pattern film is simply increased, particularly when the above-described pigment-dispersed photosensitive resin is used, a large amount of development residues and the like are generated when developing the resist pattern, Problems such as sensitivity unevenness occur.

Further, if the adhesion area between the flattening film and the colored pattern film is improved by simply increasing the adhesion area,
The overlapping area between the colored patterns of each color becomes large, and as a whole, problems such as reduced sensitivity and sensitivity unevenness occur. Also, the presence of steps in the color pattern film of the color filter causes problems such as reduced sensitivity and uneven sensitivity.

For example, in the conventional example shown in FIG. 5, the colored pattern films 132, 134 and 136 of the respective colors are formed so as to partially overlap each other. The blue and blue colored pattern films 132 and 136 have a large film thickness, so that the color filter 130 has a step. Since the adhesion between the flattening film 124 and each of the coloring patterns 132, 134, and 136 is poor as described above, the green coloring pattern film 134 having the largest number of pixels and the largest contact area among the three colors is used. By first forming the flattened film 124 and increasing the area of the green colored pattern film 134,
The bonding area with the flattening film 124 is increased, and the bonding property is increased as much as possible. As a result, the subsequently formed red and blue colored pattern films 132, 136
Are formed on the green colored pattern film 134 so as to overlap with each other, and the film thickness is large. Therefore,
In such a configuration, problems such as reduced sensitivity and sensitivity unevenness occur due to overlapping or steps between the colored patterns of each color.

When the color filter has a step, it is necessary to increase the thickness of the transparent resin film 40 in order to flatten the microlenses 142, which hinders a reduction in thickness and weight of the entire image pickup apparatus. There is a problem that is. In this type of solid-state imaging device, the distance between the light receiving element and the microlens must be reduced as much as possible due to demands for sensitivity, smear characteristics, shading, and the like as pixels become finer. As a result, the thickness of the transparent resin film cannot be reduced, and the distance between the light receiving element and the microlens cannot be reduced, so that various characteristics cannot be improved.

Accordingly, an object of the present invention is to provide a color filter capable of effectively preventing peeling of a colored pattern film, forming a flat filter surface, and maintaining good characteristics without causing sensitivity reduction or sensitivity unevenness. And a method for manufacturing the same.

[0011]

In order to achieve the above object, the present invention provides an optical device having a plurality of optical elements arranged in a matrix on a substrate. In a color filter formed by skinning a plurality of colored pattern films corresponding to each other, the plurality of colored pattern films have a plurality of pixel portions provided on the surface of each corresponding optical element. The color pattern film of at least one color among the color pattern films of a plurality of colors has a connecting portion for connecting the plurality of pixel portions in a diagonal direction of the matrix.

The present invention is also provided in an optical device in which a plurality of optical elements are arranged in a matrix on a substrate, and a colored pattern film of a plurality of colors selectively corresponding to each optical element is provided on the surface of each optical element. In the method of manufacturing a color filter formed by skinning, when forming a colored pattern film of at least one color among the colored pattern films of the plurality of colors, the method may be applied to a surface of each optical element corresponding to the colored pattern film. A plurality of pixel portions to be arranged and a coupling portion for coupling the plurality of pixel portions in a diagonal direction of the matrix are simultaneously patterned.

[0013] In the color filter of the present invention, the colored pattern film has a plurality of pixel portions provided on the surface of each optical element, and has a connecting portion for connecting the plurality of pixel portions in a diagonal direction of the pixel matrix. Thereby, the bonding state of each pixel portion is reinforced by the joint portion. Accordingly, the adhesion of the colored pattern film to the substrate itself is not increased, and the adhesion of the colored pattern film can be improved and peeling or the like can be prevented without increasing the adhesive area so much. Without forming a flat filter surface, a color filter having good characteristics can be provided.

In the method for manufacturing a color filter according to the present invention, when forming a colored pattern film, a plurality of pixel portions arranged on the surface of each optical element and the plurality of pixel portions are arranged in a diagonal direction of a pixel matrix. By simultaneously forming a pattern with the bonding portion to be bonded, a colored pattern in which the bonding state of each pixel portion is reinforced by the bonding portion can be formed. Accordingly, the adhesion of the colored pattern film to the substrate itself is not increased, and the adhesion of the colored pattern film can be improved and peeling or the like can be prevented without increasing the adhesive area so much. Without forming a flat filter surface, a color filter having good characteristics can be formed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a color filter and a method of manufacturing the same according to the present invention will be described. FIG. 1 is an explanatory diagram showing a coloring pattern of a color filter according to the present embodiment. FIG. 2 is an enlarged view showing a specific example of a pixel portion and a coupling portion constituting one coloring pattern of the color filter shown in FIG. It is a top view. FIG. 3 is a plan view illustrating a color arrangement in the color filter shown in FIG. 1, and FIG. 4 is a cross-sectional view showing an element structure in a solid-state imaging device provided with the color filter shown in FIG.

First, prior to the description of the color filter according to the present embodiment, the configuration of the solid-state imaging device shown in FIG. 4 will be described. In FIG. 4, a light receiving element 12 composed of a photodiode or the like, a transfer register unit 14 using a CCD, and the like are formed in a semiconductor substrate 10. An insulating film 16 is provided on the upper surface of the semiconductor substrate 10, and a transfer electrode 18 corresponding to the transfer register unit 14 is provided via the insulating film 16. A light-shielding film 20 is provided on the upper surface of the insulating film 16 to shield the light-receiving element 12 from light other than the light-receiving region.
Passivation film 22 is provided so as to cover the entire surface of the substrate.

A flattening film 24 is provided on the upper surface of the passivation film 22, and a color filter 30 is provided on a flat upper surface of the flattening film 24. The color filter 30 of the present example includes RGB (red, green,
(Blue) colored pattern films 32, 34, 36. As shown, each colored pattern film 3
2, 34 and 36 are formed with the same film thickness. Further, a micro lens 42 made of a transparent resin film 40 is provided on the color filter 30.

In the solid-state imaging device having the above-described configuration, each light receiving element 12 is provided in a matrix on the semiconductor substrate 10 to constitute each pixel in an imaging area. In the figure, RGB unit cells (pixel units) are provided in a matrix for each light receiving element 12. The unit cells of this example are each formed in a square shape, and in a state where adjacent cells have no gap therebetween,
Moreover, it is formed in a state in which duplication is avoided.

In the color filter 30 of this embodiment,
Each unit cell 34A of the green coloring pattern 34
(FIG. 2) are arranged in a checkered pattern in the pixel matrix shown in FIG. That is, the green unit cells 34A are provided every other pixel in the vertical and horizontal directions of the pixel matrix, and are arranged in an array adjacent to each other in the diagonal direction of the pixel matrix. As shown in FIG. 1, each of the green unit cells 34A has its corners joined by a bridging portion (joining portion) 34B formed in a diagonal thin line. That is, in this example, the green colored pattern 34 as the first color connects the unit cells 34A in a diagonal direction by the bridging portions 34B, improves the adhesiveness of the corners of the unit cells 34A, and separates the unit cells 34A. Is prevented.

By improving the adhesiveness of the green colored pattern 34 to the flattening film 24 as described above, when forming the colored pattern 34, the pressure of a high-pressure rinse or a two-fluid rinse used in the developing step is reduced. Even when the height is increased or the time is lengthened, the unit cell 34A of the colored pattern 34 does not peel off. Therefore, in such a developing step, the colored film to be removed present in the non-pixel region of the green colored pattern 34 can be reliably removed, and the residue removal rate can be improved.

The red and blue coloring patterns 3 formed after the green coloring pattern 34 are used.
2 and 36 are formed in a region surrounded by each unit cell 34A and the bridging portion 34B of the green coloring pattern 34. For this reason, since it is fixed not only by the adhesion with the flattening film 24 but also by the adhesion with the green coloring pattern 34, sufficient adhesiveness can be obtained, and it is formed in a state in which peeling or the like does not easily occur. Will be done.

Further, in this embodiment, as shown in FIG. 2, the width b of the bridging portion 34B is formed to be 1/5 or less of the length a of one side of the unit cell 34A. . In this manner, by reducing the width b of the bridging portion 34B, it is possible to minimize the influence on the adjacent pixels (red and blue unit cells 32A and 36A) and to prevent a reduction in sensitivity or uneven sensitivity. Becomes In FIG. 2, two unit cells 34A and one bridge 3
4B, the coloring pattern 34 of the present example is provided at each of the four corners of each unit cell 34A as shown in FIG.

The remaining color pattern films 32, 36 of the second color (red) and the third color (blue) of RGB are arranged in a line-sequential manner. That is, each colored pattern film 3
2, 36 unit cells (pixel units) 32A, 36A
The pixels are provided every other pixel in the vertical and horizontal directions of the pixel matrix, and are not adjacent to each other in the diagonal direction of the pixel matrix. Then, these colored pattern films 32,
In 36, a bridging portion (joining portion) for joining the unit cells 32A and 36A is not provided. Each of the unit cells 32A and 36A is cut diagonally, and is configured to avoid overlapping of the green colored pattern 34 with the bridging portion 34B. As described above, in this example, the coloring patterns 32, 34, and 36 can be arranged without overlapping, and the unit cells 32A, 34A, 36
A can be easily flattened, and a high-precision color filter 30 free from sensitivity reduction and sensitivity unevenness can be provided.

Further, since the color filter can be flattened in this manner, the formation of the above-described microlens 42 is facilitated, and the thickness of the transparent resin film 40 can be reduced.
That is, when the color filter is not flat and the step is large as in the conventional example shown in FIG. 5, it is necessary to increase the thickness of the transparent resin film in order to flatten the microlens. In the example, even if the color filter 30 is flattened and the transparent resin film 40 is thinned, the microlens 42 can be easily flattened. Thus, the reduction in thickness and weight of the transparent resin film 40 can contribute to the reduction in thickness and weight of the entire imaging device, and can contribute to the reduction in size and weight of various devices provided with the imaging device.

In this type of solid-state imaging device, the distance between the light receiving element 12 and the microlens 42 needs to be reduced as much as possible due to demands for sensitivity, smear characteristics, shading, and the like as pixels become finer. Therefore, by flattening the color filter 30 and reducing the thickness of the transparent resin film 40 as in the present example, the distance between the light receiving element 12 and the microlens 42 can be reduced, and various characteristics of the solid-state imaging device can be achieved. Can also contribute to the improvement of

As a method for forming the colored pattern films 32, 34, 36 of the color filter 30 as described above, for example, a dyeing method or a color resist method can be used.
In the dyeing method, an organic film (film to be dyed) such as casein or gelatin is coated on the flattening film 24, dried, and exposed by a mask.
After pattern development, the patterned organic film is dyed and fixed. In the color resist method, a photosensitive resin composition (resist) in which a pigment or an insoluble dye having a distribution of a predetermined particle size (for example, 1 μm or less) is dispersed in a resin is applied on the flattening film 24 and dried. , Mask exposure and pattern development. When forming the green colored pattern film 34 in the formation process of such a colored pattern film, the pattern having the unit cell 34A and the bridging portion 34B described above is used as the mask exposure pattern. , FIG.
The green colored pattern film 34 shown in FIG.

In the present invention, in the above-described dyeing method, color resist method and the like, a film in which a region exposed by mask exposure becomes soluble or insoluble becomes a photosensitive element film in a broad sense. In this case, any method may be employed for forming the above-described colored pattern film. In the above example, an example in which the color filter of the present invention is applied to a solid-state imaging device has been described. However, the present invention is not limited to this, and can be widely applied to, for example, a color filter of an LCD display device. . In the above example, the example of the color filters for the three primary colors of RGB has been described. However, for example, a color filter for a complementary color of RGB or a single color filter can be similarly applied.

[0028]

As described above, in the color filter of the present invention, the colored pattern film has a plurality of pixel portions provided on the surface of each optical element, and the plurality of pixel portions are arranged in a diagonal direction of the pixel matrix. By having the coupling portion to be coupled, the bonding state of each pixel portion is reinforced by the coupling portion. Accordingly, the adhesion of the colored pattern film to the substrate itself is not increased, and the adhesion of the colored pattern film can be improved and peeling or the like can be prevented without increasing the adhesive area so much. Without forming a flat filter surface, a color filter having good characteristics can be provided.

In the method of manufacturing a color filter according to the present invention, when forming a colored pattern film, a plurality of pixel portions arranged on the surface of each optical element and the plurality of pixel portions are arranged in a diagonal direction of a pixel matrix. By simultaneously forming a pattern with the joints to be joined, a colored pattern in which the adhesion state of each pixel portion is reinforced by the joints is formed. Accordingly, the adhesion of the colored pattern film to the substrate itself is not increased, and the adhesion of the colored pattern film can be improved and peeling or the like can be prevented without increasing the adhesive area so much. Without forming a flat filter surface, a color filter having good characteristics can be formed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an example of a color filter according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view showing a specific example of a pixel unit and a coupling unit which constitute one coloring pattern of the color filter shown in FIG.

FIG. 3 is a plan view illustrating a color arrangement in the color filter shown in FIG.

FIG. 4 is a cross-sectional view showing an element structure in a solid-state imaging device provided with the color filter shown in FIG.

FIG. 5 is a sectional view showing an element structure in a conventional solid-state imaging device.

[Explanation of symbols]

10 semiconductor substrate, 12 light receiving element, 14 transfer register section, 16 insulating film, 18 transfer electrode, 20
... Shielding film, 22... Passivation film, 24... Flattening film, 30... Color filter, 32, 34, 36.
... Colored pattern film, 32A, 34A, 36A ... Unit cell (pixel part), 34B ... Bridge part (coupling part), 4
0: transparent resin film, 42: microlens.

Claims (14)

[Claims] 1. An optical device having a plurality of optical elements arranged in a matrix on a substrate, wherein a plurality of colored pattern films corresponding to the respective optical elements are selectively applied on the surface of the respective optical elements. In the color filter formed as described above, the plurality of colored pattern films have a plurality of pixel portions provided on the surface of each corresponding optical element, and at least one of the plurality of colored pattern films is provided. Wherein the colored pattern film includes a coupling portion that couples the plurality of pixel portions in a diagonal direction of the matrix. 2. The pixel portion of each of the plurality of colored pattern films is formed in a square shape, and the pixel portions of each of the colored pattern films are arranged without any gap therebetween. The color filter according to 1. 3. The colored pattern film of a plurality of colors is a colored pattern film of three colors, and a colored pattern film of a first color among the three colors is such that each pixel portion is one in a vertical direction and a horizontal direction of the matrix. A colored pattern film that is provided at every pixel and adjacent to each other in the diagonal direction of the matrix and has a coupling portion that couples each pixel portion, and the remaining second and third color pattern films of the three colors Is that each pixel portion is provided every other pixel in the vertical and horizontal directions of the matrix, and is arranged in an array that is not adjacent to the matrix in a diagonal direction, and has no coupling portion that couples each pixel portion. The color filter according to claim 2, wherein: 4. The color filter according to claim 3, wherein the three colors are red, green, and blue, and the first color is green. 5. The color filter according to claim 2, wherein the connection portion is formed in a thin line shape connecting the corner portions of the plurality of pixel portions. 6. The color filter according to claim 5, wherein a line width of the connection portion is formed to be 1/5 or less of one side of the pixel portion. 7. A colored pattern film other than the colored pattern film provided with the coupling portion cuts a corner portion of each pixel portion,
The color filter according to claim 5, wherein the color filter is formed so as to avoid overlapping with the connecting portion. 8. An optical device in which a plurality of optical elements are arranged in a matrix on a substrate, and a colored pattern film of a plurality of colors corresponding to each optical element is selectively applied on the surface of each optical element. In the method for manufacturing a color filter formed by: forming at least one color pattern film among the plurality of color pattern films, the color filter is disposed on the surface of each optical element corresponding to the color pattern film. A method of manufacturing a color filter, wherein a plurality of pixel portions and a connecting portion that connects the plurality of pixel portions in a diagonal direction of the matrix are simultaneously formed in a pattern. 9. The color filter according to claim 8, wherein each of the pixel portions is formed in a square shape, and the connecting portion is formed in a thin line shape connecting corner portions of the plurality of pixel portions. Manufacturing method. 10. The line width of the coupling part is one of the pixel part.
The method for manufacturing a color filter according to claim 9, wherein the color filter is formed at １ ／ or less of one side. 11. A coloring pattern film other than the coloring pattern film provided with the coupling portion, cuts corner portions of each rectangular pixel portion disposed on the surface of each optical element corresponding to the coloring pattern film, The method according to claim 9, wherein the color filter is formed so as to avoid overlapping with the connecting portion. 12. The colored pattern film, after forming a photosensitive element film over the entire optical region of the substrate, exposing the photosensitive element film through a mask corresponding to a predetermined pattern shape, and by exposing the photosensitive element film, The method for manufacturing a color filter according to claim 9, wherein the pattern is formed by developing the changed pattern of the photosensitive element film. 13. The method for manufacturing a color filter according to claim 12, wherein the photosensitive element film has a colorant dispersed therein in advance. 14. The photosensitive element film is made of a material to be dyed,
The method for producing a color filter according to claim 12, wherein the material to be dyed is colored by dyeing after the development.