JPS6349703A - Manufacture of color filter - Google Patents

Abstract

PURPOSE:To increase the density of a color filter by using an optical cross- linkage type transparent polymer for a transparent polymer layer and treating it in a developing process after exposure by using rinse liquid which contains a photopolymerization initiator, and then carrying out a heat treatment successively. CONSTITUTION:A silicon substrate 10 where a photodiode array 1 and many image pickup element chips made of Al wiring 2, etc., are arrayed is spin-coated with the optical cross-linkage type transparent polymer to form a thin film and the surface of the substrate 10 is flattened to form a flattened layer 5a. Then this flattened layer 5a is exposed 12 through a desired chromium mask 11 to form a bonding pad 3, a scribe line 4, etc. Then a 1st color filter layer 8 is formed on the flattened layer 5b and then an optical cross-linkage type transparent polymer is applied to form an intermediate layer 6a, and a light reacting group which remains in a nonreaction state after light irradiation is made to react thermally; to form an intermediate layer 6b; and a 2nd color filter layer 9 is formed and a protection layer 7b is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a color filter.

[Conventional technology]

A conventional example is shown in Japanese Patent Publication No. 52-17375, for example. FIG. 4 shows a cross-sectional configuration of a color separation filter that is directly mounted on a solid-state imaging device.

In Fig. 4, the conventional direct-mounted color separation filter is a photodiode array! and a planarization layer 5 made of a transparent polymer on a silicon substrate 10 on which a large number of image pickup device chips made of An wiring 2 and the like are arranged. The intermediate layer 6 and the protective layer 7 are sequentially formed, and a first layer dyed to a required color density is formed between the flattening layer 5 and the intermediate layer 6 and between the intermediate layer 6 and the protective layer 7, respectively. A color filter layer 8 and a second color filter layer 9 are formed.

In addition, in the figure, 3 is a pounding bat, and 4 is a scribe line.

Here, the first color filter layer 8 and the second color filter layer 9 form, for example, a blue filter and a yellow filter, respectively, and the flattening layer 5. The intermediate layer 6 and the protective layer 7 are positive type (light-cuttable) that can be patterned by ultraviolet rays or far ultraviolet rays.
Alternatively, each layer is typically formed by one or more exposures and development, ie, a photolithographic process, using a negative-working (photocrosslinkable) transparent polymer.

Of the three layers configured in this way, the planarization layer 5
Since the first color filter layer 8 is formed directly on the inorganic silicon substrate 10 and the first color filter layer 8 is formed thereon, the unevenness of the substrate 10 is flattened as much as possible, and the inorganic and organic substances are The stress caused by the difference in the expansion coefficient of the can be fully absorbed.

In addition, it is required to have sufficient strength to withstand this stress.

Further, regarding the intermediate layer 8, the first color filter layer 8
It is necessary to separate the color filter layer 9 from the second color filter layer 9 to effectively prevent color mixing in the process. Strength to protect an area or entire display area,
Additionally, it is required to have light resistance.

So L2 again. These three layers meet strict color requirements for imaging and display devices.

It is essential to have a light transmittance of 100% within the visible light range.

[Problem that the invention seeks to solve]

In this way, in conventional direct-mounted color separation filters,
In order to satisfy the above-mentioned required performances and buttering properties, a positive or negative type transparent polymer' is used as the flattening layer 5. It is used to form the intermediate layer 6 and the protective layer 7, but in this case, the former positive resist essentially does not have sufficient strength to take advantage of its photo-cutting properties, and However, since the latter negative-type resist only has photo-crosslinking properties due to buttering, its strength is still insufficient.1 For example, in device reliability tests, there are undesirable problems such as deformation of the filter layer. there were.

This invention was made to solve these conventional problems, and its purpose is to solve these problems without significantly changing the process or filter structure or reducing throughput. The strength of the protective layer, intermediate layer, and protective layer has been improved. An object of the present invention is to provide a method for manufacturing a color filter with high reliability.

Means for Solving Problem C] In order to achieve the above object, the method for manufacturing a color filter according to the present invention provides a method for manufacturing a color filter in which a color filter layer and a transparent polymer layer are sequentially laminated, and the transparent polymer layer In this method, a photocrosslinkable transparent polymer is used, and when the photocrosslinkable transparent polymer is developed after exposure, it is rinsed with a rinsing liquid containing a thermal polymerization initiator, and then heat treated.

[For production]

In other words, in this +1 method, the photoreactivity of the photocrosslinkable transparent polymer during exposure is not perfect, and even after exposure, a considerable amount of photoreactive groups (many of which contain carbon-carbon 2-type packing) remain. In view of the fact that unreacted particles remain, a thermal polymerization initiator is added and dissolved in the rinsing liquid during development processing, and by processing with this rinsing liquid, it is uniformly dispersed in the crosslinked polymer. The thermal polymerization initiator effectively acts to promote the reaction of unreacted photoreactive groups through the subsequent post-baking, that is, heat treatment, and the formation of a layer with a more highly densified crosslinked structure becomes possible.

〔Example〕

Hereinafter, one embodiment of the method for manufacturing a color filter according to the present invention will be described in detail with reference to FIGS. 1 to 3.

In the method of this embodiment, as shown in FIG. After coating the substrate 10 to form a thin film and flattening the surface of the substrate 10 to form a flattening layer 5a, the flattening layer 5a is exposed to light through a desired chrome mask 11 to form a bonding pad 3. Then, scribe lines 4 and the like are formed.

When forming this layer, the process is carried out in the order of exposure → development → rinsing + boss baking using the photolithography technique described above. Butyronitrile) is added and dissolved in a rinsing solution, followed by a post-bake treatment, that is, a heat treatment, to remove unreacted residual photoreactive groups (many of which contain carbon-carbon double bonds) after light irradiation. ) to form a planarized layer 5b having a more highly densified crosslinked structure, as shown in FIG.

Next, after forming the first color filter layer 8 on the flattening layer 5b, a photo-crosslinkable transparent polymer is applied thereon in the same manner as described above to form an intermediate layer 8a.
The same treatment as for the flattening layer is performed to thermally react the photoreactive groups remaining unreacted after light irradiation to form intermediate fi8b as shown in FIG. 3.

Furthermore, after forming the second color filter layer 9 on the intermediate layer 6b, the uppermost protective layer 7b is formed by the same means as described above.

That is, in forming each layer of the flattening layer, intermediate layer, and protective layer, a photocrosslinkable transparent polymer is used, and at the time of development treatment after exposure.

By performing a rinse solution treatment containing a thermal polymerization initiator and then a post-baking treatment, crosslinking reactions between and within the polymer molecules, which were insufficient due to the photoreaction caused by exposure, are further promoted, resulting in higher crosslinking density. This makes it possible to significantly improve the properties of each layer, such as strength and heat resistance, which were insufficient in the past, and to form a flattened layer 5b, an intermediate layer 6b, and an intermediate layer 6b with a more dense crosslinked structure. A color filter that can form the protective layer 7b and has sufficient resistance to, for example, high-temperature storage, low-temperature storage, thermal shock testing, etc., can be constructed, and pattern deformation can be completely eliminated.

As the photo-crosslinkable transparent polymer used in this example, a polymer having double or triple bonds in the main chain or side chain can be used. Specifically, examples include a copolymer of methacrylate and glycidyl methacrylate having a chalcone group, a copolymer of vinyl cinnamate and glycidyl methacrylate, and chloromethylated polystyrene, but of course, the invention is limited to these. It is not something that will be done. Note that oligomers having double bonds or the like may be added to the polymer as long as they do not cause undulation during development.

In addition to the above-mentioned azobisisobutyronitrile, the thermal polymerization initiators added to the rinse solution in this example include:
Other compounds such as 2,2'-azobis(2,4,4-trimethylpentane), which is a more stable high-temperature decomposition type, are benzoin, various peroxides such as benzoyl peroxide, or toluene. Aromatic sulfonic acids such as sulfonic acids can be used, but are not limited to these, and the amount added is influenced by the efficiency of the initiator, the boost bake temperature and time, etc. Therefore, although it cannot be determined with certainty,
In the case of typical azobisisobutyronitrile, 0.
About 1% to 5z is sufficient, and the post baking temperature is 150 to 180°C for about 30 to 15 minutes.
The following effect appears.

In the above embodiments, all layers, including the flattening layer, intermediate layer, and protective layer, are treated with a rinsing liquid containing a thermal polymerization initiator, but the treatment may depend on the type of polymer used.

It is sufficiently effective even if it is applied to only two or one of the three layers.

Further, in the above embodiment, the manufacturing process of a type color separation filter is described in which direct mounting for a solid-state image sensor is used. However, the manufacturing process is not necessarily limited to this. For example, a filter layer is created on a glass substrate and the image sensor is It can also be applied to the production of color filter layers for liquid crystal displays.

[Effects of IJ+]

As described in detail above, when using the method of the present invention, when a color filter layer and a transparent polymer layer are sequentially laminated, a photocrosslinkable transparent polymer is used for the transparent polymer layer, and the photocrosslinkable transparent polymer During the development process after exposure, the material was rinsed with a rinsing liquid containing a thermal polymerization initiator, and then heat-treated, so that the thermal polymerization initiator was uniformly dispersed within the crosslinked polymer during the rinsing process. , and the subsequent heat treatment can promote the reaction of unreacted photoreactive groups during exposure in the photoreactive transparent polymer, thereby forming each layer, that is, the flattening layer, the intermediate layer, and It is possible to achieve high density of the protective layer, etc., and its characteristics such as layer strength, optical properties, heat resistance, and reliability,
As a result, the sexual rotation of the color filter itself can be dramatically improved, and as a result, it has excellent features such as being able to prevent deformation of the filter due to, for example, thermal shock.

[Brief explanation of the drawing]

1 to 3 are sectional views showing an outline of an embodiment of the color filter manufacturing method according to the present invention in the order of steps, and FIG. 4 is an outline of a color filter to which the same conventional method is applied. FIG. 3 is a sectional view showing the configuration. l...Photodiode array, 3...Ponding butt, 4...Scribe line, 5a, 5b
... Flattening layer, 8a, 8b ... Intermediate layer, 7b.
...Keep it! 1 layer. 8 and 3...first and second color filter layers, lO...silicon substrate. 1st (21 1: Photodiode array 1o: Silicon curtain 3: y: Indicators)
il: chrome mask 4: scribe line 12: plein air ('shu 5c8 end! ka layer 2nd! 21 5b: 4 [i (layer 60: ko n layer 8: katsuhui ■ retano-kai 3rd figure 9; power larfilk Scrap Figure 4 Procedural Amendment (Voluntary) Mr. Commissioner of the Patent Office Indication of Case 918 Patent Application No. 6T-TQT+Z4G No. 2, Name of Invention Narafui IL-1n Ship 1E Gaito 3, Person Making Amendment 5, Subject of Amendment ( 1) Column for detailed description of the invention in the specification (2) Drawing 6, content of amendments (1) "Highly stable - trimethylpentane)" on page 9, lines 6-7 of the specification was replaced with "dimethyl 2,2" - Azo f sobutyrate". (2) Figure 2 of the drawings is revised as shown in the attached sheet. Above Figure 2 5b: et2 and ihi layer 5q: ci'rti1 layer 8: sword kufiltano tongue

Claims (1)

[Claims] (1) A method for manufacturing a color filter in which a color filter layer and a transparent polymer layer are sequentially laminated and photolithography is used to form at least the transparent polymer layer, in which a photocrosslinkable transparent polymer is added to the transparent polymer layer. 1. A method for producing a color filter, which comprises rinsing with a rinsing liquid containing a thermal polymerization initiator during development after exposure, followed by heat treatment.