JPH04128703A - Production of color filter - Google Patents

Abstract

PURPOSE:To facilitate material administration and to improve and stabilize patterning accuracy by applying color materials dissolved with photosensitive agents and dyes in a resin on a substrate and solidifying the color materials to form color layers, then patterning the color layers by exposing and developing, thereby forming the color patterns. CONSTITUTION:The color materials dissolved with the photosensitive agents and dyes in the resin are applied on the substrate 1. The color materials are solidified to form the color layers 12 and the color layers 12 are patterned by exposing and developing to form the color patterns 12P. Namely, the color patterns 12P are formed by using the materials prepd. by previously incorporating the dyes at prescribed ratios into a synthetic resin, such as acrylic resin, with which the patterns having stable and uniform quality are easily obtainable. The need for the intricate material administration and the administration of the dyeing liquids is eliminated in this way and the color filters having the good patterning accuracy and uniform quality are stably formed.

Description

[Detailed Description of the Invention] [Summary] Regarding the manufacturing method of color filters, especially color filters used for colorizing solid-state image sensors, there is no need for complicated material management or dyeing solution management, and the method improves patterning accuracy. With the aim of stably forming color filters of good and uniform quality, a coloring material made by dissolving a photosensitizer and a pigment in resin is applied onto a substrate, the coloring material is solidified to form a color layer, and the color The method includes the step of patterning the layer by exposure and development to form a color pattern.

[Industrial application field]

The present invention relates to a method of manufacturing a color filter, and particularly to a method of manufacturing a color filter used for colorizing a solid-state image sensor.

In color filters used for colorizing solid-state image sensors, the filter pattern has become finer, more precise, and
Uniformity and stability of color tone are strongly desired.

[Conventional technology]

Color patterns in conventional color filters are formed by patterning a photosensitive film of gelatin, casein, fish gris, or the like by exposure and development, and then dyeing the film in a dye solution.

The method will be described below by way of example with reference to FIGS.

Refer to FIG. 3(a). In other words, in the solid-state image sensor forming a color filter, as shown in the figure, a photodiode (PD) formed of a silicon (Si) substrate 1 and an impurity-introduced layer 2 connects each pixel. An aluminum (AI) wiring 3 is formed on the substrate, and the surface is covered with a phosphosilicate glass (PSG) layer 4.

Refer to FIG. 3(b). In the conventional color filter manufacturing method, a flat layer 5 made of acrylic resin is applied onto the substrate on which the image sensor is formed to flatten the substrate surface, and then a photosensitive layer is applied on the substrate. A gelatin film (negative type) 6 is deposited, and then areas other than desired pixels are covered with a photomask 7 and exposed. Note that 8 indicates ultraviolet (UV) light, and 106 indicates a photosensitive area.

3 (see C1) Next, the gelatin film 6 is developed to form a first layer of undyed patterns 6A.

Refer to FIG. 3(d). Next, the undyed pattern 6A is dyed in a predetermined color.
Complete the first layer color pattern 6AA.

Referring to FIG. 3(e), an interlayer separation layer 9 made of acrylic resin (the flat layer 5
) is applied and formed.

Refer to Figure 3) Then, repeat the steps (a) to (d) above to
Color pattern 6AA, 6AB of three colors that are complementary colors of primary colors,
6AC is formed with an interlayer separation layer 9 interposed therebetween.

FIG. 3 (see gl) Finally, the substrate on which the third layer color pattern 6AC is formed is covered with a protective layer IO made of acrylic resin.
It had been completed.

[Problem to be solved by the invention]

However, as mentioned above, in conventional color filters, natural products such as gelatin, casein, and fish gris are used for color pattern materials, so material quality cannot be controlled due to variations in quality at the time of purchase, deterioration over time, etc. At the same time, it is difficult to do so, and it also causes variations in processing accuracy during patterning.Also, since the coloring of the color pattern is done by dyeing, the control of the concentration and pH of the dye solution is very delicate, making it difficult to maintain a constant color tone. There was a problem in that it was very difficult to obtain it stably.

Therefore, an object of the present invention is to stably form a color filter with good patterning accuracy and uniform quality without the need for the above-mentioned complicated material management and dyeing solution management.

[Means to solve the problem]

The above problem is to apply a coloring material made by dissolving a photosensitizer and a dye in resin onto a substrate, solidify the coloring material to form a color layer, and pattern the color layer by exposure and development to form a color pattern. The problem is solved by a method for manufacturing a color filter according to the present invention, which includes steps.

[For production]

That is, in the present invention, synthetic resins such as acrylic and novolak resins, which can stably obtain homogeneous and better quality materials than natural materials, are used as materials for color patterns, thereby facilitating material management and patterning. Improved accuracy and stability.

Furthermore, by imparting photosensitivity to the synthetic resin, patterning of a color pattern is made possible through exposure and development, thereby preventing the need for a process bath during color pattern formation.

Furthermore, since the color tone of the color pattern is adjusted by mixing a pigment into the synthetic resin and adjusting its content, a constant color tone can be easily obtained by controlling the pigment content, and the color tone can be changed over time. never changes.

As a result, compared to conventional products that use natural products such as gelatin, it has higher pattern accuracy, can stably obtain uniform performance, and has high quality and high reliability with less deterioration over time. A color filter is formed.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to illustrated embodiments, including sectional views,
FIG. 2 is a diagram showing the decolorizing effect of a photosensitizer by full UV irradiation.

Identical objects are indicated by the same reference numerals throughout the figures.

Refer to FIG. 1(a) When forming an on-wafer type complementary color filter for a solid-state image sensor by the method of the present invention, as in the conventional method,
A photodiode formed on one surface of a Si substrate by an impurity-introduced layer 2 of a conductivity type opposite to that of the substrate constitutes each pixel, an AI wiring 3 is formed on the substrate, and the top thereof is covered with a PSG layer 4. First, a flat layer II made of spin-on glass (SOG) is applied on the black-and-white solid-state image sensor 101 to flatten the substrate surface, and then a P(MMA+MA) resin, which is an acrylic resin, for example, is coated on top of the flat layer II made of spin-on glass (SOG). A color layer 12 having a thickness of about 0.5 μm is formed by adding a photosensitizer and a dye to a resin made of a copolymer of methacrylate and maleic anhydride.

At this time, the P(MMA+MA) resin is dissolved in the solvent in an amount of about 6 to 15% by weight using ethyl cellosolve acetate (ECA), cyclohexanone, etc. as a solvent.

For example, 0-naphthoquinonediazide (positive type) is used as the photosensitizer, and is added to the resin solution at a rate of 20 to 30% by weight.

In addition, pigments include, for example, cyan (Cy), orazole blue GN, magenta (Mg), orazole pink 5BLG, and yellow (Ye).
) using Orazole Yellow 2GLN. (All made by Ciba-Geigi) And, all of these dyes have a 2 to
6% by weight dissolved.

The resin thus prepared is then applied by spin coating and heated to drive off the solvent and solidify.

Refer to FIG. 1(b) Next, a desired pixel region is covered with a photomask 7 and exposed to ultraviolet (UV) light 8. 112 indicates a photosensitive area. In this UV exposure, the color layer containing Cy or Mg was exposed to UV light with a wavelength near the g-line (wavelength 436 nm), and the color layer containing Ye was exposed to i-line (35 nm).
It is desirable to use UV light that contains many wavelengths around 6 nm).

1 (see C1) Next, the color layer 12 is developed using an ordinary alkaline developer, and the photosensitive area 112 is dissolved and removed to form a first color pattern (for example, Ye) 12P.

Refer to FIG. 1(d) Next, the entire surface on which the color pattern (Ye) 12P is formed is irradiated with UV light 8 for about lθ seconds, and the color pattern (Ye) 12P is
Decolorizes the photosensitizer contained in the. Through the above steps, the first color pattern (Ye) 12P is completed.

Note that the UV light used for the above-mentioned entire surface irradiation uses a wavelength near the g-line for a color pattern containing Cy or Mg, and a wavelength near the i-line for a color pattern containing Ye, as in the case of the above-mentioned pattern exposure. This is desirable.

Fig. 2 is a diagram showing the decolorizing effect of the photosensitizer by the above-mentioned UV whole-surface irradiation, and from this figure, from the above-mentioned U
~700nm wavelength of light detected by the image sensor (λ)
It can be seen that the transmittance (T) of light with a wavelength of 500 nm or less, which had a low transmittance (T), is improved to 90% or more, similar to that of light with a wavelength of 500 nm or more.

Refer to FIG. 1(e). Next, a 0.5 μm thick SOG film is formed on the surface on which the first color pattern (Ye) 12P is formed by a spin code method.
The first interlayer separation layer 13 is formed to a certain extent.

Refer to Fig. 1 (Fig. 1). Then, repeat the steps from Fig. 1 (a) to (e) to obtain a second color pattern (for example, Cy) 14P, SOG.
A second interlayer separation layer 15 consisting of 16P and a third color pattern (for example, Mg) 16P are sequentially formed as shown in the figure, and then a layer of SOG made of SOG is formed on the third color pattern (Mg) tep formation surface by a spin code method. Protective film 1 with a thickness of about 0.7 μm
7 is coated to complete the color filter according to the method of the present invention.

The resin according to the present invention includes P(
Acrylic resins other than MMA+MA) resins, novolac resins, etc. can also be used.

In addition, in the above embodiments, the present invention is carried out on-wafer.
Although the description has been made regarding a color filter using a bonding method, the present invention is of course also applicable to manufacturing a color filter using a bonding method, in which a color filter is formed on glass and then bonded to an element.

〔Effect of the invention〕

As explained above, according to the present invention, a color pattern is formed using a synthetic resin such as an acrylic resin that can easily be obtained with stable and uniform quality, and a dye is mixed in a predetermined proportion. Compared to conventional color filters that use natural materials and dyeing methods, delicate management of materials and dyeing solutions is no longer required, and the quality is also improved and stable. .

Furthermore, since the resin is not a natural product and has a homogeneous and stable composition, patterning accuracy during color pattern formation is also improved.

As described above, the present invention greatly contributes to improving the performance, manufacturing yield, and reliability of color solid-state image sensors.

[Brief explanation of the drawing]

Figures 1(a) to 3) are process cross-sectional views of an embodiment of the method of the present invention. Figure 2 is a diagram showing the decolorizing effect of the photosensitizer by irradiating the entire surface with UV light. Figures 3(a) to ( g) is a process sectional view of the conventional method. In the figure, l is a Si substrate, 2 is an impurity introduction layer, 3 is an AI wiring, 4 is a PSG layer 7 is a photomask, 8 is an ultraviolet (UV) light, 11 is a flat layer, 12 is a color layer, 12P is a first layer 13 is a first interlayer separation layer, 14P is a second color pattern, 15 is a second interlayer separation layer, 16P is a third color pattern, and 17 is a protective film. At the end, CS, Nro 56, Ichijike-sha 10 process cross-sectional diagram No. 1
Concave C well/)D Final completion g'A/) Lum n-Pre-process face on the real light side'l#,
7 11EI (Jf/)2) UVX-Full-frontal 5
Photosensitizer O Decolorization is not allowed.Figure 62 Concave number (one thousandth)

Claims (1)

[Claims] 1. A coloring material prepared by dissolving a photosensitizer and a dye in a resin is applied onto a substrate, the coloring material is solidified to form a color layer, and the color layer is patterned by exposure and development to create a color. A method for manufacturing a color filter, the method comprising the step of forming a pattern. 2. The method of manufacturing a color filter according to claim 1, wherein the dye is a dye that transmits light at a wavelength to which the photosensitizer is sensitive. 3. A method for manufacturing a color filter, comprising the step of irradiating the color pattern formed by the method according to claim 1 with ultraviolet light to decolorize the photosensitizer contained in the color pattern.