JPS62113106A - Production of color separation filter - Google Patents

Abstract

PURPOSE:To improve the characteristics of flattening, intermediate and protective layers such as the strength and resistance to heat and ultrasonic waves by forming layers having a filter held between them with a photo-cross-linkable transparent polymer, forming a prescribed image and irradiating light having a wavelength at which the photoreaction of the polymer can be caused. CONSTITUTION:A photo-cross-linkable transparent polymer is spin-coated on a silicon substrate having many image pickup element chips arranged on the surface to for a flattening layer 5'. This layer 5' is exposed and developed to form a desired image and rays of light having a wavelength necessary for the photoreaction of the polymer, that is, photo-cross-linking rays 12' are irradiated on the layer 5'. The 1st color filter 8 is formed on the photo-cross linked flattening layer 5'', the photo-cross-linkable transparent polymer is coated again to form an intermediate layer 6', this layer 6' is exposed and developed, and postirradiation is carried out to from a photo-cross-linked intermediate layer 6''. A protective layer as the top layer is similarly processed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing color separation filters used in imaging and display devices and the like.

[Conventional technology]

FIG. 5 is a cross-sectional view of a conventional color separation filter formed directly on a solid-state imaging device as shown in Japanese Patent Publication No. 52-17375, and this color separation filter consists of photodiode arrays (11 and A1). A silicon substrate (
10) A flattening layer (5), an intermediate layer (6), and a protective layer (7) made of a transparent polymeric material are formed in sequence on top of the flattening layer (5) and the intermediate layer (6). A first color filter (8) and a second color filter (9) each dyed to a required color density are formed between the layer (6) and the protective layer (7). First color filter (8
) and the second color filter (9) constitute, for example, a blue filter and a yellow filter, respectively. The flattened IJ (51, intermediate layer (6) and protective layer (7) are made of positive type (photocuttable) or negative type (photocrosslinkable) transparent polymer material that can be patterned with ultraviolet rays or deep ultraviolet rays. , each layer is usually exposed and developed one or more times, that is, by a photolithography process.

Of the three layers configured in this way, the planarization layer (5) is formed directly on the inorganic silicon substrate (10), and since the first color filter (8) is formed on this, the base +f
It is necessary to flatten the unevenness of f1 (10), sufficiently absorb the stress due to the difference in expansion coefficient between inorganic and organic materials, and have sufficient strength to withstand this stress. In addition, the intermediate layer (6) needs to be able to separate the first color filter (8) and the second color filter (9) and prevent color mixing during the process. 71 is the second color filter (9)
It is also necessary to have strength and light resistance to protect the entire imaging area or display area. In addition, these three layers must have a light transmittance of 100% in the visible light range due to strict color performance requirements for imaging and display devices.

[Problems to be Solved by the Invention] In order to satisfy the above-mentioned performance and buttering properties, conventional positive-type or negative-type transparent photoresists are
layers, namely a planarization layer (5), an intermediate layer (6), a protective layer (
7), but since positive resists utilize their photo-cleavability, they essentially cannot obtain sufficient strength, and negative resists cannot be strengthened by photo-crosslinking alone through buttering. There was a problem in that the filter layer was deformed during, for example, device reliability testing.

This invention was made to solve the above problems, and it is possible to increase the strength of the flattening layer, intermediate layer, and protective layer without significantly changing the process or filter structure or reducing throughput. The object is to obtain a method for manufacturing color separation filters with improved and high reliability.

[Means for solving problems]

The method for manufacturing a color separation filter according to the present invention includes a method for manufacturing a color separation filter in which a filter is held between layers (a laminated layer forming body is formed of a photo-crosslinkable transparent polymer material, and a filter is further formed of a photo-crosslinkable transparent polymer material). The layer-formed product is one in which, after forming a desired image by exposure, the photocrosslinkable transparent polymer material is irradiated with light having a wavelength capable of photoreacting.

[For production]

The method for producing a color separation filter according to the present invention is to form a layer-forming body from a photo-crosslinkable transparent polymer material, and after forming a predetermined image by exposure, unreacted light is removed by irradiating it with light of a photoreactive wavelength. The crosslinking groups react sufficiently and the bridge density is greatly improved, thereby dramatically improving the strength of the layered product and improving reliability such as heat resistance.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, photodiode array (1) and A1 arrangement! l-,'ff (consisting of 21 etc.) First, light is
A cross-linked transparent polymer material is spin-coded to form a thin film to flatten the surface of the substrate (10), and a flattening layer (5'
) to form. In order to make this flattened N (5') into a desired shape, a chrome mask (11
) is disposed above and exposed by irradiating the exposure light beam (12) from above. As a result, desired bonding butts (3), scribe lines (4), etc. are formed in the areas where the chrome mask (11) is not provided.

After the exposure is completed in this way, further development is carried out.
After forming the desired image, as shown in FIG. 2, the wavelength necessary for the photoreaction of the photocrosslinkable transparent polymeric material is applied to the flattening layer (5') made of the photocrosslinkable transparent polymeric material. A photocrosslinked flattening layer (5') is formed by irradiating the substrate with a photocrosslinking light beam (12').

Next, on the planarization layer (5”) formed in this way, a third
A first color filter (8) is formed as shown in the figure. Then, a photocrosslinkable transparent polymer material is applied from above in the same manner as shown in FIG. 1 to form an intermediate layer (6').
After exposure and development, post-irradiation is performed to form a photocrosslinked intermediate layer (6").
) on which a second color filter (9) is formed.

Further, the same process is repeated for the uppermost protective layer. That is, as described above, the photocrosslinked intermediate layer (
A photo-crosslinkable transparent polymer material is applied on top of the film (6") to form a protective layer (7"), and after further exposure and development, post-irradiation is performed to form a photo-crosslinked protective layer (7"). do. A flattening layer (5") and an intermediate layer (6") formed of a photocrosslinkable transparent polymer material photocrosslinked by post-irradiation in this way.
A color separation filter with a protective layer (7'') is formed as shown in FIG.

As described above, a layer forming body such as a flattening layer, an intermediate layer, a protective layer, etc. is composed of a photo-crosslinkable transparent polymer material, and the photo-crosslinking transparent polymer material is irradiated with a photo-crosslinking beam for post-irradiation. As a result, photo-crosslinking reactions between and within molecules of the polymer material, which were insufficient only through exposure for image formation, are carried out sufficiently, and the flattening layer and intermediate layer, which were previously insufficient, are , properties such as film strength, heat resistance, and ultrasonic resistance of layer forming bodies such as protective layers have been significantly improved. As a result, it becomes easier to set the conditions in the assembly process, etc., and the reliability of the imaging device, such as high-temperature storage, low-temperature storage, high-temperature operation, and even thermal shock tests, becomes easier, and the filter pattern There is no longer any deformation or dye oozing.

The photo-crosslinkable transparent polymer material used in this invention can be photo-crosslinked by adding an oligomer or low molecular weight polymer having a photo-crosslinkable reactive group, or by copolymerizing it into the polymer chain of the main component. The il that has been given gender is used. Transparent polymer materials include, for example, acrylic polymers with excellent light transparency such as polymethyl methacrylate, polyethyl methacrylate, polyglycidyl methacrylate, and polyethyl acrylate, as well as polystyrene, polychloromethylstyrene, chlorinated polymethylstyrene, etc. Polycarbonate etc., but are not limited to these, 4
Any material may be used as long as it absorbs only a small amount of visible light in the range of 00rv+ to 700nm, has excellent thin film forming properties, and has or can be provided with photocrosslinking properties. After 400 nm to 70
The absorption of visible light in the 0 nm range is negligible, it does not dissolve from the residual film during development, and it has excellent storage stability when added to transparent polymer materials or copolymerized. is necessary. Photocrosslinkable materials that meet these conditions include hinyl cinnamate and its derivatives, derivatives containing chalcone or oxychalcone groups, and furthermore derivatives containing epoxy rings, double bonds, and triple bonds. It is mentioned, well.

Examples of substances that promote photocrosslinking include diazo compounds and organic halogen compounds, but the present invention is not limited to these.

The photocrosslinking light used in this invention may be ultraviolet rays or far ultraviolet rays used in normal exposure, and the irradiation dose must be at least five times the appropriate exposure dose used during image formation. The upper limit is determined within a range that does not cause deterioration of the dye dyed with the filter and does not significantly reduce the throughput.

In addition, in the above example, it was explained that post-irradiation is performed for all layers, including the planarizing layer, the intermediate layer, and the protective layer, but the post-irradiation is not limited to this. Even if it is applied only to the middle layer, the effect is sufficient.

Furthermore, in the above embodiments, the direct mounting for solid-state image elements is explained for the production of type color separation filters, but the invention is not limited to this, and the production of filters on glass substrates for bonding and for liquid crystal displays. It can also be applied to the manufacture and manufacture of color separation filters such as the following.

〔Effect of the invention〕

As described above, according to the present invention, the laminated layer forming body to hold the filter therebetween is formed of a photo-crosslinkable transparent polymer material, and after forming a predetermined image by exposure, a photoreactable wavelength is formed. Because it is irradiated with light, properties such as film strength, heat resistance, and ultrasonic resistance of the layer forming body, i.e., the flattening layer, intermediate layer, protective layer, etc., are significantly improved, and for example, the properties of the filter due to thermal shock etc. are improved. This has the excellent effect of eliminating deformation and dramatically improving the reliability.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the process of forming a flattening layer according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the process of post-irradiation with a photocrosslinking beam, and FIG. FIG. 4 is a cross-sectional view showing the irradiation process; FIG. 4 is a cross-sectional view of a solid-state image sensor with a direct color separation filter formed by post-irradiation using a photo-crosslinking configuration; FIG. 1 is a cross-sectional view of a solid-state image sensor having a color separation filter. (5'), (6'), (7') are a flattening layer, an intermediate layer, a protective layer, (layer forming body'), (5' l, (6 ”), (7”) are flattening layers, intermediate layers, and protective layers (layer forming bodies) photo-crosslinked by post-irradiation.
, (81, (91) is a filter, and (12'') is a photocrosslinking light beam. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A method for manufacturing a color separation filter having a layer forming body laminated to hold a filter therebetween, characterized in that the layer forming body is formed of a photo-crosslinkable transparent polymer material. Production method. (2) After the layer-forming body formed of the photo-crosslinkable transparent polymer material forms a desired image by exposure, the photo-crosslinkable transparent polymer material is irradiated with light having a wavelength capable of photoreacting. A method for manufacturing a color separation filter according to claim 1, characterized in that: