JPH0215201A - Solid-state image pickup element - Google Patents

Abstract

PURPOSE:To improve the workability in element production by forming photodetecting parts on a solid-state image pickup element substrate and forming layers of color sepn. filters directly thereon. CONSTITUTION:The layer of a base material for the color sepn. filters is formed on the color solid-state image pickup element substrate 2 formed with the many photodetecting parts 10 and a driving circuit part 11 for driving said parts. Only the parts 2 of the 1st color of this layer are photoset and developed, by which only the parts 2 of the base material for the color sepn. filters are made to remain. These parts are dyed by a dye having a prescribed spectral characteristic. The surface is then coated with a transparent intermediate layer 5 and thereafter, the layer of the base material for the next color filters is formed and similarly the filter parts 3 for the 2nd color are formed and are dyed. Further, the surface is coated with a transparent intermediate layer 6 and the color filters 4 are similarly formed and are dyed; following which a protective film 7 is formed. The intermediate layer layers 5, 6 and the protective film 7 can be directly mounted on the substrate 1 by using the radiation sensitive org. high-polymer material having the spectral characteristics different from the spectral characteristics of the filter layers 2, 3, 4 and, therefore, the workability in element production is improved.

Description

[Detailed description of the invention] [Field of application of the invention 1 The present invention relates to a solid-state image sensor.

The present invention is particularly useful for a color solid-state image sensor in which a color separation filter is mounted directly on a photodetector.

[Background of the Invention] Conventionally, a common manufacturing method is to manufacture a solid-state image sensor and a color separation filter separately, and then bond them together using an optical adhesive or the like while aligning the two.

There have also been reports of using optical matching oil instead of optical adhesive.

Furthermore, a method for manufacturing a polychromatic optical filter is disclosed in Japanese Patent Application Laid-open No. 53-99822, and a method for manufacturing a color separation filter is disclosed in Japanese Patent Application Laid-Open No. 14-7823. There is no mention of directly providing a filter.

Further, although a color imaging device and a method for manufacturing the same are disclosed in Japanese Patent Application Laid-Open No. 53-47282, there is no mention of radiation-sensitive materials at all.

Regarding the multilayer composition, Japanese Patent Application Laid-Open No. 50-834.25
Although the publication discloses radiation-sensitive materials in the publication, these are merely techniques related to containers and plywood.

[Object of the Invention] A first object of the present invention is to mount a color separation filter directly on the light detection section of a solid-state image sensor, thereby improving the workability of manufacturing the device.

A second object of the present invention is to make the color separation filter in this case sufficiently accurate and of high quality.

[Summary of the Invention 1 The first point of the present invention is to use a radiation-sensitive organic polymer material for the so-called intermediate layer and protective layer constituting the color separation filter, which is advantageous for the subsequent manufacturing process of the solid-state image sensor. be.

Second, it is more preferable that the organic polymer material described above has thermal crosslinkability. This is useful for strengthening intermediate layers used in the laminated structure of color separation filters.

Thirdly, it is extremely advantageous for the radiation-sensitive organic polymer material to be of a so-called positive type in terms of process simplification. Even if it has negative radiation sensitivity, this property can be used for processing the filter part. However, as each intermediate layer is formed, it becomes necessary to perform crosslinking by exposing to a predetermined radiation, which increases the number of steps. Of course, even if a positive radiation-sensitive organic polymer material is used, each of the intermediate layers described above may be formed and exposed to a predetermined radiation, and then developed and subjected to the desired processing. Of course, it is okay to do so. When each layer is processed, the number of steps is the same as in the case of negative molding. However, even in this case, the positive type has the following advantages. That is, in the case of a positive type, a portion of the organic polymer material layer to be removed is exposed to radiation, whereas in the case of a negative type, a portion of the organic polymer material to be left is exposed to radiation. Naturally, the color separation filter matrix is the part where the layer of the organic polymer material remains. Therefore, in the case of a negative type, the base material of the one-color separation filter is also irradiated with exposure radiation several times, which affects the deterioration of the filter characteristics. In the case of positive type, there is no such influence at all.

Also, in many cases 1. The filter base material is also used by imparting photosensitivity, but in this case, the photosensitivity characteristics of the filter base material and
Preferably, the materials of the intermediate layer and the protective layer have different optical properties. When processing the filter base material, it is necessary not to affect the materials of the intermediate layer and protective layer that exist below it.

The radiation-sensitive organic polymer materials useful in the present invention include the following.

(1) Poly-alkyl methacrylate or copolymer thereof CH3 (-CH2-C-)-1 C○○R However, R is an alkyl group, for example, CH3゜4H9 - Polyglycidyl methacrylate or copolymer thereof CH3 1+CI(2-〇+n Saki CH.

Strive CH2-C-)-0 0NH2 polymethyl isopropenyl ketone CH3 CH2-C+.

COCH3 Poly (Butene 1 sulfone) + CH.

CH) (SO2) tenn CH2 CI(.

Polyisobutylene CH3 +CT(2-C-)-n CH3 It goes without saying that radiation-sensitive organic polymeric materials other than these examples can be used. Of course, as the radiation-sensitive organic polymer material, those sensitive to ultraviolet rays, electron beams, X-rays, etc. can be used.

As used herein, the term "radiation sensitivity" includes these various types.

[Embodiments of the invention] Hereinafter, the present invention will be explained in detail according to specific examples.

1 to 4 show the manufacturing process of the color solid-state image sensing device of the present invention. Both are cross-sectional views of the main parts of the elements. FIG. 5 is a plan view thereof.

At least a large number of photodetecting sections 10 and a perturbation circuit section 1 for driving them are formed on the color solid-state image sensor substrate 1. Note that the detailed structure in the semiconductor substrate 1 is omitted. Generally, the substrate 1 is made of silicon. The photodetector may be made of the same substrate as the semiconductor integrated circuit that forms the peripheral circuitry for operating the photodetector, or may be made of a different type of semiconductor material.

On the second substrate of such a color solid-state image sensor, a layer of a base material of a color separation filter is formed to a thickness of about 0.5 to 2.5 μm. This matrix is generally gelatin or egg white.

Materials such as green, casein, and poval that have been imparted with photosensitivity are used. The photosensitive characteristics are 365 using negative type.
It is common to have sensitivity in the nm to 435 nm range.

By photo-curing only the first color portion 2 of this layer using a mask exposure method and developing it, only the portion 2 of the color separation filter base material remains. This area is dyed with a dye having predetermined spectral characteristics. Note that the dyeing method may be a conventional method using an aqueous dye solution.

In addition, when forming the layer of the filter base material of the first color, it is preferable to form a film of an organic polymer material on the surface of the substrate 1 to a thickness of about 0.5 to 1 μm. The surface of the substrate is further planarized by this coating of organic polymer material. This brings about the following advantages.

(1) The semiconductor device portion provided in the substrate 1 is protected from contamination such as impurities.

(2) The surface of the substrate 1 is flattened, making it easier to form the intermediate layer, filter matrix layer, etc. formed on the top thereof, and preventing color mixture during dyeing, which occurs especially due to deformation of the intermediate layer. You can.

(3) In the color filter processing process, the adhesion area of impurities is reduced, which is useful for preventing contamination of semiconductor devices in the substrate.

Note that it is advantageous for later processing to use a radiation-sensitive organic polymer material for forming the above-mentioned intermediate layer and the like as the organic polymer material.

Next, a transparent dye-resistant intermediate layer 5 is formed to a thickness of 0.5 to 1.5 mm.
Coat to μm. This is the state shown in Figure 1. The aforementioned radiation-sensitive organic polymer material is used for this intermediate layer. In this case, as described above, it is preferable to select a material having radiation sensitivity characteristics different from those of the color separation filter base material.

Next, as shown in FIG. 2, a layer of color filter base material is formed, exposed using a mask exposure method, and developed to form a second color filter portion 3, which has predetermined spectral characteristics. Dye with dye. Furthermore, a transparent intermediate layer 6 is coated.

Furthermore, as shown in FIG. 3, a color filter 4 is formed and dyed, and then a protective film 7 is formed.

In addition, intermediate M6. The protective film 7 also uses the same radiation-sensitive organic polymer material as the intermediate layer 5.

Through the above steps, three color separation filters are formed.

Note that dyeing for forming a color filter may be performed by determining the dye preparation, content, temperature of the dye solution, and dyeing time according to conventional methods.

Table 1 shows specific examples of the filter base material, intermediate layer, and protective layer.

Further, examples of staining conditions are shown below.

(1) Dye formulation green blue red Dyeing temperature.

time green color 40'C.

2 minutes blue color 40°C2 1 minute red color 40℃.

Among the radiation-sensitive materials mentioned above, for example polymethyl methacrylate-methacryloyl chloride copolymers, which belong to polyglycidyl methacrylate, polymethyl methacrylamide and copolymers with polymethyl methacrylate, are thermally crosslinkable materials.

In the case of such materials, by heating the intermediate layer at a temperature that causes thermal crosslinking after coating, the intermediate layer improves its water resistance and functions more effectively as a dye-resistant layer.

If the heating temperature and time are 200° C. for about 15 minutes, polymerization due to crosslinking will proceed to a considerable extent, resulting in the above-mentioned improvement in water resistance, etc.

This heat treatment is usually performed after forming each intermediate layer and the like.

A mask is applied leaving desired portions of the color solid-state image sensor substrate 1, such as the bonding butt portion 12, and exposed to ultraviolet light. The exposure conditions are as shown in Table 1. If far ultraviolet light is used as the light source, an X e -Hg lamp (IKW
) is a renma. Next, the desired portion is removed by developing the 31G laminated material for filter formation.

In this way, desired portions such as bonding pad portions are opened.

FIG. 5 is a plan view of the color solid-state image sensor.

As shown in the figure, a photodetection section 14, a circuit 15 for driving the photodetection section, and a bonding section 12 are arranged in a silicon chip substrate. A color filter, such as a mosaic pattern, is formed in the light detection section by the method described above. Remove the filter material in the bonding area using the method described above, and then remove the filter material from the bonding area.
The bat is exposed. Next, Au or AQ-8i
(Sj content 0.5-1111t%)
Ultrasonic bond to the pad. Or Au-8i (Au
(content 10 wt%) may be thermocompression bonded to an Au bonding pad.

In this way, a color solid-state image sensor is completed.

In the above specific example, processing of the bonding para I part 12 and the like for the radiation-sensitive material layer includes (1) the coating formed on the surface of the semiconductor substrate 1, (2) each intermediate layer, and (3)
Although a protective film and the like are laminated and post-processing is performed, it goes without saying that each layer may be processed or, for example, every two layers may be processed.

[Effects of the Invention] According to the present invention, a color separation filter can be directly mounted on a solid-state image sensor, and workability in manufacturing the device can be improved.

Furthermore, color separation filters can be provided with high precision and high quality.

[Brief explanation of the drawing]

1 to 4 are sectional views of the color solid-state image sensing device according to the present invention, and FIG. 5 is a plan view of the color solid-state image sensing device. DESCRIPTION OF SYMBOLS 1... Solid-state image sensor board, 2, 3. 4... Color filter part, 5, 6... Intermediate layer, 7... Protective film.

Claims (1)

[Claims] 1. A color separation filter section is provided on an upper part of a semiconductor substrate having at least a photodetection section in which a plurality of photodetection elements are arranged and a wiring section, and the color separation filter section has a desired shape. A predetermined number of filter layers having predetermined spectral characteristics and transparent radiation-sensitive organic polymer material layers are sequentially laminated, and the filter layer and the radiation-sensitive organic polymer material layer are different from each other. What is claimed is: 1. A solid-state imaging device having spectral characteristics and having at least wiring provided through a region where the radiation-sensitive organic polymer material layer is locally removed. 2. Claim 1, wherein the radiation-sensitive organic polymer material layer has positive radiation sensitivity.
The solid-state image sensor described in .