JP2710899B2 - Method for manufacturing color solid-state imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a color solid-state imaging device in which a mosaic color filter for color separation is directly formed on a substrate on which a solid-state imaging device is formed.

[0002]

2. Description of the Related Art Conventionally, as a method of directly forming a color filter on a solid-state imaging device, first, a transparent polymer resin is applied for flattening the surface of the device, and then a photosensitive layer is formed as a color filter layer. A material such as gelatin, casein, PVA or the like, which has been prepared and clay adjusted, is applied, a desired pattern is formed by exposure and development, and further, a desired dyeing property is obtained by dyeing with an appropriate dye. Then, for the purpose of preventing color mixing in the next dyeing process,
The same transparent polymer resin as that used for planarization is applied as an intermediate film. By repeating the above steps,
A color filter composed of yellow, cyan, magenta, and green color groups is realized. FIG. 3 is a cross-sectional view at the time of exposure showing a method of manufacturing the above-described conventional color solid-state imaging device. In FIG. 3, reference numeral 11 denotes a substrate on which a solid-state image sensor is formed, 12 denotes a light-receiving portion of the solid-state image sensor, 13 denotes an aluminum light-shielding film, 14 denotes an acrylic flattening layer coated with a transparent polymer resin, 15 denotes gelatin and casein. , PVA or the like, and 16 is a photomask.

[0003]

However, in the above-mentioned manufacturing process, in the step of patterning the color filter layer, that is, in the step of exposing and developing a material such as gelatin, casein, glue, PVA, etc. with a photomask, The pattern finishing method and shape do not match the pattern on the photomask, and usually, a phenomenon occurs in which the edge is more blurred than the pattern on the photomask. Generally, in patterning exposure of a photosensitive resin, light contributing to exposure is caused by incident light and light reflected from a substrate surface. In the case of a solid-state imaging device, in the image area, the portion other than the photodiode portion is shielded from light by an aluminum film, and the photodiode portion, the CCD portion and the like are rich in irregularities. in this way,
When patterning a dyeing base on an element surface with a highly uneven surface covered with high reflectivity aluminum, a flattening layer
Since the intermediate layer is a highly transparent material, the reflected light from the substrate is not attenuated even if it passes through this layer, and the irregularly reflected light from the underlayer directly exposes the dyed base area other than the pattern on the photomask. In this method, the direct formation technology of the color filter corresponding to the reduction of the pixel size and the reduction of the separation width between the pixels accompanying the increase in the number of pixels of the solid-state imaging device in the future, the filter of the filter between the adjacent pixels. The problem that color mixing cannot be avoided occurs. That is, in FIG.
There is a problem that the pattern (negative resist 15) covers the upper part of the light receiving section 12 due to abnormal pattern dimension and blurring of the pattern edge due to the reflected light from the aluminum light shielding film 13.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the pattern dimension abnormality of the dyed base layer and the blurring of the pattern edge.
An object of the present invention is to provide a method of manufacturing a color solid-state imaging device capable of improving the accuracy of a mosaic pattern shape.

[0005]

According to a method of manufacturing a color solid-state imaging device of the present invention , a plurality of light receiving portions are formed on a substrate.
And a metal light-shielding film is formed between
Solid-state imaging device having a color filter formed on its part
Manufacturing method, wherein the flattening layer formed on the substrate
Apply a positive photoresist and apply the positive photoresist
By exposing and developing the photoresist,
Remove the positive photoresist on the top and
Form a covering photoresist pattern, and then
Negative photoresist on substrate with resist pattern
The negative photoresist is exposed and developed.
Positive photoresist on top of the metal light-shielding film
Dyed base made of negative photoresist
Embedded in the storage layer.

[0006]

According to the manufacturing method of the present invention , on the flattening layer
Upper part of the coated metal film of the positive photoresist applied
Photoresist pattern that removes and covers the top of the light receiving section
To form a positive photoresist on top of the metal light-shielding film.
Since the stained base layer made of a negative photoresist is embedded in the removed portion, abnormal pattern dimensions of the stained base layer and blurring of the edge of the pattern shape can be improved, and the accuracy of the mosaic pattern shape for color separation can be improved.
Therefore, color mixing of the filters between adjacent pixels can be completely prevented, and the image quality can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a color solid-state imaging device according to the present invention.
Indicates that a plurality of light receiving parts are formed on the substrate and the adjacent light receiving parts
A metal light-shielding film such as aluminum is formed between
Of color solid-state imaging device with color filter
This is described below with reference to the drawings . FIG. 1 is a sectional view in the order of steps showing a method for manufacturing a color solid-state imaging device according to an embodiment of the present invention, and FIG. 2 is a sectional view of the final step. First, as shown in FIG. 1A, an acrylic planarizing layer 4 is formed by applying a transparent polymer resin on the surface of a substrate 1 on which a solid-state imaging device is formed. Reference numeral 2 denotes a light receiving portion of the solid-state imaging device, and reference numeral 3 denotes an aluminum light shielding film.

Next, as shown in FIG. 1 (b), a high-resolution positive resist 5 is spin-coated and exposed with light such as g-line, h-line, i-line using a photomask 6, and the light-receiving portion is formed. 2A, a resist pattern 5a shown in FIG.
To form Next, as shown in FIG. 1 (d), after a negative resist 7 such as gelatin, casein, PVA or the like is spin-coated on the surface, a photomask 8 of a pattern that leaves the negative resist 7 between the resist patterns 5a is formed. Exposure using
develop. Thereby, as shown in FIG. 2, a negative resist (stained base layer) 7a is formed between the resist patterns 5a.
Is embedded. Then, a negative resist 7
a is treated (eg, stained) to have a spectral color (eg, black) that absorbs ultraviolet rays including g-line, h-line, and i-line. The photomasks 6 and 8 are set so that the negative resist 7a is embedded in the upper part of the aluminum light shielding film 3 and the negative resist 7a does not exist in the upper part of the light receiving part 2.

As described above, according to this embodiment, the resist pattern 5 having a removed portion above the aluminum light shielding film 3 is provided.
a, and a negative type resist 7a as a dye base layer is buried in a removed portion of the resist pattern 5a.
Abnormal pattern dimensions of the negative resist 7a and blurring of the edge of the pattern shape can be improved, and the accuracy of the mosaic pattern shape for color separation can be improved. for that reason,
It is possible to completely prevent the color mixture of the filter between the adjacent pixels and improve the image quality. Further, it is possible to cope with a reduction in pixel size.

When the negative resist 7a is dyed black in order to suppress unnecessary irregular reflection on the aluminum light-shielding film 3, the transmittance is 50% or less in the wavelength region of 365 nm, 405 nm and 436 nm.

[0011]

According to the method of manufacturing a color solid-state imaging device of the present invention, a positive type photoresist coated on a flattening layer is formed.
The upper part of the metal light shielding film is removed to cover the upper part of the light receiving part.
A photoresist pattern is formed, and the top
Negative photoresist on the part where the di-photoresist is removed
For embedding the dyeing base layer made of, can improve blurring of edge patterns dimension abnormality and the pattern shape of the dyeing base layer, it is possible to improve the accuracy of the mosaic pattern of color separation. Therefore, color mixing of the filters between adjacent pixels can be completely prevented, and the image quality can be improved. Further, it is possible to cope with a reduction in pixel size.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a method of manufacturing a color solid-state imaging device according to an embodiment of the present invention in the order of steps.

FIG. 2 is a sectional view of a final step in the embodiment.

FIG. 3 is a cross-sectional view at the time of exposure showing a method for manufacturing a conventional color solid-state imaging device.

[Explanation of symbols]

 2 Light-receiving part 3 Aluminum light-shielding film 4 Flattening layer 5 Positive resist 5a Resist pattern 7a Negative resist (staining base layer)

Claims (1)

(57) [Claims] A plurality of light-receiving portions formed on a substrate;
A metal light shielding film is formed between the light receiving portions
Solid-state imaging device having a color filter formed on its part
Manufacturing method, wherein a positive photoresist is formed on the planarizing layer formed on the substrate.
And then expose the applied positive photoresist.
By light and development, the port on the metal light shielding film is exposed.
Remove the di-type photoresist and cover the upper part of the light receiving part
After forming a photoresist pattern, the photoresist
Negative photoresist on substrate with resist pattern
The negative photoresist is exposed and developed.
By doing so, the positive-type transistor on the metal light-shielding film is formed.
From the negative photoresist to the part where the photoresist is removed
A method for manufacturing a color solid-state imaging device, comprising embedding a stained base layer .