JPS59172607A - Color filter - Google Patents

Abstract

PURPOSE:To obtain a green color filter which has a colored layer formed under control over film thickness by vacuum deposition while thin-film interference effect is utilized and has large difference in quantity of transmitted light between the light transmission wavelength area and a light attenuating wavelength area. CONSTITUTION:A pigment film has such film thickness that the transmittance to a light wave with a 550nm wavelength in the transmission wavelength range is maximum or at least between Tmax and Tmax.X85% within the film thickness range wherein a light wave of 450 or 650nm in the attenuation wavelength range has transmittance below a specific value. The refractive index of the colored layer used for a green color filter should be smaller than that of a substrate in order to set the optimum film thickness of the colored layer. Further, the center wavelength, i.e. 550nm is selected normally as a wavelength within the green transmission wavelength range, and 450 and 600nm are selected as representative wavelengths in the attenuation wavelength range. Then, the transmittance of light with some wavelength in the attenuation wavelength range should be some set value for the color filter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a green-based fine color separation filter used for color displays and the like.

As a conventional general color filter, an organic dyed filter is known in which an organic polymer plate M is formed on a substrate and further dyed with a dye.

However, creating these filters requires a lot of man-hours and time due to dyeing, which is inefficient.

In addition, as the dyed layer, that is, the colored transparent layer, becomes relatively thick,
The first step is to make the thickness uniform, so Toukiro 1! Ke11:
[There was a drawback that the second prize was uneven.

On the other hand, coloring material deposition, in which a hue is surface-formed on a substrate by vacuum deposition and this colored layer is used as an optical filter layer, is an excellent color filter that eliminates the drawbacks of the dyed filters. In addition, it has the advantage that the production cost is low relative to sales, and the produced eyebrow color layer has excellent heat resistance. In particular, since the colorant is deposited directly onto the substrate without using a mordant layer or a hue retaining layer such as a binder, it is easy to obtain the precision required for an imitation fine color separation filter, and the coloring layer can be formed from only the colorant. M'IN. Because it is done,
Even if the layer thickness is thin, a reliable amount of light absorption can be easily obtained for the color filter.

However, when the thickness of the colored layer is on the order of a wavelength of light or less, the oscillation of the colored layer as a light absorption layer differs from that known in the past. That is, the influence of multiple beam interference appears, and the 495 pass rate characteristic curve with respect to film thickness changes becomes a curve having periodic peak values instead of the conventionally well-known monotonically decreasing curve. This is especially true for light transmission wavelength 1, written by Vrj.

This phenomenon complicates the problem of spectral blurring of the color material %'fQ color filter, so conventionally this has been avoided. 7. To stop the colored layer, by layering a layer with the same refractive index as the colored layer, the entire layer can be made faster and the effects of optical interference can be reduced, or (or by adding an appropriate thickness) By controlling the shoulder colors 1- and 7 (Jlif 111 of the transparent layer with a power factor of 4), the table j77, i due to optical interference can be changed to θ・1′〈small (Unexamined Japanese Patent Publication No. 1983)
-30.108).

However, depending on the color material, the 49i' rate can be changed (ill
J) I am having difficulty in selecting the same hue for multiple colors in A). Tazuko is a miserable and needy older sister.

The present invention has been proposed in view of the above points, and has a colored layer formed by controlling the film thickness by vacuum evaporation to make use of the thin film interference effect. The purpose is to provide a color filter that increases the difference in the amount of transmitted light in wavelength ranges.

Briefly, the light transmission characteristics and phenomena of the colored layer, which are the premises of the embodiments of the present invention, and the conditions for obtaining the F4 thickness of the colored layer according to the present invention will be briefly explained.

Generally, when light passes through a light-absorbing thin film, the amount of transmitted light and reflected light are determined by the refractive index (n) and attenuation rate (k) of the thin film and the upper and lower layers of the thin film, as well as the auxiliary film. thick cl
). Among these, the refractive index and the attenuation factor are specific to the thin film (here, the colored layer) and the upper and lower layers. Therefore, in order to control the amount of transmitted light, it is necessary to change the film thickness.

FIG. 1 is a diagram showing the relationship between the light transmittance for light in the transmission wavelength range and the thickness of the colored layer.

The solid line is the optical density/light formation curve when the optical interference effect is added as a pre-layer, and the broken line is the film thickness-light transmission curve when the optical interference effect is not provided as the pre-layer. In the figure, w'→thickness of the colored layer is about 1.5 mm thick, which is about the same as the wavelength of this light. The order of By)
Although the nature of the light transmission curve changes, this figure shows when the refractive index of the substrate is better than that of the colored layer.

Figure 2 (d shows the relationship between the light transmittance for light in the attenuation wavelength range and the thickness of the colored layer. In this case); the thickness of the false color layer is about the same as the wavelength of this light. Even if it is on the order of +d or less, the intensity of the transmitted light is pretty good and there is no interference effect.

Figure 3 is similar to Figure 1 except for the condition that the refractive index of the edge color layer is higher than the refractive index of the substrate. λ′1 color layer gland j
This is a diagram showing the relationship between the first and the first. The solid line is the thickness-light transmittance curve when considering the optical interference effect, and the solid line is the film thickness when the optical interference effect is not taken into consideration. This differs from the case shown in Figure 1 in that the transmittance decreases due to interference effects.

Furthermore, since light in the attenuation wavelength range does not exhibit an interference effect, the characteristics are not affected by the condition that the refractive index of the colored layer is higher than the refractive index of the substrate, and therefore the film thickness - light transmission wavelength range is The same relationship as in FIG. 1 is shown.

Next, the conditions for setting the optimum film thickness of the colored layer used as the green color filter are determined from the above characteristic diagram. First, a colored layer having a refractive index lower than that of the substrate is used. Higher transmittance in the transmission wavelength range)j
This is because there is a possibility to select the film thickness (Figs. 1 and 3).
). As a wavelength in the green transmission wavelength range, we usually choose 550 nm, which is the center wavelength, and 4.50 nm and 650 nm as representative wavelengths in the attenuation wavelength range.
Reflects the wavelength of nm.

The reason why two wavelengths can be safely used as representatives of the attenuation wavelength range is because there are attenuation wavelength ranges in both I'l+il of the transmission wavelength range. Assuming that Fig. 1 is a diagram showing the ratio of 1-thickness to undersizing at a wavelength of 550 nm, and Fig.
It is assumed that this is a diagram showing the relationship between film thickness and transmittance. A necessary condition for a color filter is that the transmittance of wavelengths in the Δ·1 wavelength range is equal to or less than a certain set value. If the set value is now t1%, the film thickness at that time is d] according to FIG. 2, so the required 1j thickness is 61 or more. However, for a wavelength of 650 nm, a thick core thickness that satisfies the set value condition can be obtained from a relationship diagram similar to that shown in FIG. Assuming that the film thickness is do<d+, the setting condition is f17i in the two attenuation wavelength regions, and the film thickness condition is d or more. Under this condition, the transmittance of wavelengths in the transmission wavelength range is maximum)
The desired film thickness is obtained from FIG.

That is, in FIG. 1, the film thickness exhibiting the maximum permeability TITIax in the range of )j odor thickness d1 or more is d2. In this way, the film thickness in the direction of the film can be set, but in reality, the film J
``There will be variations in the J setting, and the film thickness does not necessarily have to show the maximum transmittance.For example, if TlTl is greater than 2, then the desired film thickness setting range can be determined from Figure 1. id: dmin(d(dmax
It is.

Next, a case will be described in which the one-green color filter according to the embodiment of the present invention is applied to a solid-state image sensor.

Example 1 FPM was placed on top of the solid-state image sensor formed on it.
210 was coated and the film thickness was increased to 700 using the spinner coating method.
Set it to 0A. After drying, prebaking is performed at 150 to 200° C. for 30 to 60 minutes, and then striped mask exposure is performed with deep ultraviolet light. Furthermore, a resist mask was formed by performing a predetermined development process. Next, the entire surface of the wafer film on which the resist mask was formed was irradiated with deep ultraviolet light to make it unresponsive to the solvent.

Next, Ueno-- and lead phthalocyanine packed in a molybdenum (MO) boat were placed in a vacuum container with a vacuum degree of 10 to 1.
Mo boat at 450-550℃ at 0-” Torr
The thickness of the deposited film was set as follows based on the above-mentioned principle. First, the refractive index (n) and attenuation rate (k) of lead phthalocyanine were determined using a polarization analysis method. As a result, at the wavelength in the transmission wavelength range (λ-550nm), n =
1.4. k = 0.01, and the wavelength (λ
= 450 nm), n = 1, 5.1 (= 03 at another wavelength (λ = 650 nm), n - 1, 0, =
It was 09. Incidentally, the refractive index of Si is n=42 (λ=
550nrn), n = 5.0 (λ = 45
0nm) +n=3. s (λ = 650 nm). When the relationship between film Jl and light transmittance is graphed using this Ij white, Figure 4 (λ-550nm) s Figure 5-1 (λ-450nm) + Figure 5-2 (λ-650nm)
becomes. When the transmittance in the wavelength range is set to 3% or less, it can be seen that the film thickness needs to be 190 nm or more as shown in FIG. 5-1, and 200 nm or more as shown in FIG. 5-2. Therefore, in order to satisfy both conditions, a film thickness of 200 nrn or more is required. Under these conditions, the tentative length of the transmission wavelength range or the film thickness that exhibits the maximum transmittance is d = 290n from Figure 4.
m, and the maximum transmittance is 75%. 1
However, when it is assumed that the transmittance in the transmission wavelength range is at least a certain set value, the range in which the film thickness should be set accordingly can be determined from FIG.

In the example, the deposited film was set to an optimum film thickness of 290 nm. After that, FPM210D (FPIVi21
A color filter was formed on the wafer by dissolving the resist mask and simultaneously removing unnecessary portions of the deposited film.

For comparison, a conventional color filter, ie, a color filter using an organic polymer film, will be explained.

First, a gelatin layer was formed on the wafer, and Brilliant India Blue (manufactured by Hoechst) and Suminol Yellow MR (manufactured by Hoechst), which have almost the same spectral absorption characteristics as lead phthalocyanine, and Suminol Yellow MR (
(manufactured by Sumitomo Chemical) and patterning was performed using a known photoetching method using a resist. The relationship between film thickness and transmittance at this time is shown in Figure 6 (transmission wavelength range).

It is shown in FIG. 7 (attenuation wavelength range). As is clear from the figure, the optimal film thickness setting value is 4000 nm, and the maximum transmittance in the transmission wavelength range is 60%. From now on, it is clear that
The color filter according to the present invention has a color filter of 15% compared to the conventional one.
It is also possible to obtain high transmittance.

Example 2 A case will be described in which a liquid crystal display is manufactured using a green color filter according to the present invention. f, a 5N02 transparent electrode plate formed on a glass plate was used as a substrate, and chlorinated phthalonanine (C,
1, Nα74260) to form a colored layer. Thereafter, PGMA is formed as a adhesive film of a colored layer. Thereafter, a striped pattern was formed using the same procedure as in Example 1. The refractive index of 5n02 is n = 2.0°, and the refractive index of PGMA is n = 149, and the thickness is close to the optimal film thickness value obtained from the film thickness-transmittance relationship diagram created using these values. A colored layer having a thickness of 300 nrn was formed.

As a result, a green filter with a transmittance of 70% in the transmission number range was obtained. This was pasted onto a liquid crystal board to create a liquid crystal color display.

As described above, according to the present invention, the filter 4 can also be easily made into a color filter with good properties. Because it is a thin film, it is suitable for microfabrication, and is particularly useful as color filters for image sensors and displays that require high precision.

Note that the substrate used for the color filter according to the present invention can be selected depending on the purpose of use and is not particularly limited.

For example, specifically the following can be used:

Glass plates, optical resin plates, gelatin, polyvinyl alcohol, hydroxyethyl cellulose, methyl methacrylate, polyester, butyral.

It is a film made of polyamide. It is also possible to form a Knobler filter integrally with the object to which it is applied. An example of a substrate in this case is a solid-state image sensor 9 such as a CCD (charge coupled device), BBD (packet brigade device), CID C charge injection device), a cathode ray tube display surface, and a light receiving surface of an image pickup tube. Examples include photoreceptors for color photography, liquid crystal displays, and color photoreceptors.

Any coloring material for the colored layer' that can be vacuum-deposited can be used without any problem.

For example, (1) monoazo colorant monolite of naphthols, Green Y (C0■.N[L 12514 ) (2) triphenyl. Methane colorant Yirgalite, Green BN (C, 1, NO, 4204-0:], )-Dainichi,
Fast Green B (C, 1, No 42000:2) (3) Nitroso Colorant Monolite, Green B (C, I. Ni1.10006
) Monozole, Gly-7B (C-tNo, 1002
0:↑) (4) Phthalocyanine-based chlorinated phthalocyanine (C, 1, No, 74260
) (C,, I. No., 74255) Lead phthalocyanine Also, the resist used in the present invention is appropriately selected and used. The typical photoresists (product names) are "OFI" R series (2,77, 78,800).
"" OMR/Leads (8L' 83.
85. 87) “”TPR””SV
R'"OS R""'TPS" and above manufactured by Tokyo Ohka,"
KMI) R-809""'KMR-747"" K
MR-752””’ KTFR-”” KPR-3””
KPR-1” or higher made by Kodak, “JSR-CBR”
J 5R-CBR-901"" J 5-R-CI R
-701" or more made by Japan Synthetic Rubber" Waycoat LS
I Re5ist ”” HPRPositive
Re5ist (104,106)””Waycoat
(HNR, HNR-999, Negative HR
,IC,Type3IC,SC)
AZ 1350 ``AZ ] 350J'' and above manufactured by Sibley, as far ultraviolet resists, ``0DUR series (1,000, 1001, 1,01, 0, 1, O
]71. .

]] OWR, 120) '''Manufactured by Tokyo Ohka,'' AZ
2400-DUV “Manufactured by Sibley” HP R (20
4,20'6) '''Made by No. Nto,''F'BMI 1
0 ””FBMI 20 ”’”FPM210 ”Diamond 7m or more, as a resist for electron beam,” 0
Ei3R (1000, 1010, 1030, 100)
"Tokyo Ohka" 5EL (N + T V pe A,
T Y p e F) “Nmar Ura,” FIV
IR (]01゜E102) "Made by Fuji Raku Products," EBR
(1, 9) Examples include ``Toshi-made.''

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the characteristics of a color filter according to an embodiment of the present invention, and shows the transmittance of light in the transmission wavelength range when the refractive index of the substrate is higher than the refractive index of the colored layer and the film j♀
Figure 2 is a similar relationship diagram for light in the attenuation wavelength range, and Figure 11. Good 1 (power of the board) + 4J
Figure 1 shows the relationship between the film thickness and the transmittance of light in the vortex wave region when the i index is lower than the refractive index of the colored layer. Light (λ-55
Figures 5-1 and 5-2 show the relationship between the transmittance and film thickness for λ2450nrn), Figure 5-1, and Figure 5-2, respectively.
A similar relationship diagram between the transmittance of m + λ = 650 nm and the II thickness, Figure 6 shows the results of the Brilliant India Blue and Suminol Yellow MR formed on the S1 plate according to the conventional example.
Light in the transmission wavelength range of the mixed dye filter (λ-55
Figure 7 shows a similar relationship between the transmittance (0 nm) and film thickness for light in the attenuation range. 1-1...Film thickness with interference effect - Light transmission small curve 1-2
・Film thickness with no interference effect - Light transmission small curve: 3-1...Film thickness without interference effect - Light transmission small curve 1 3-2...Film thickness with interference effect- Light transmission type surface silk patent applicant Canon Co., Ltd. Figure 1 Figure 2 190nm Figure 5-1 00nm Figure 5-2

Claims (1)

[Scope of Claims] (]) In a color filter in which a dye 1iA is formed on a substrate, the dye film has a transmittance of a predetermined value or less for light waves with wavelengths of 4.50 nm and 650 nm in the attenuation wavelength range. The maximum transmission weight or at least Tmax is for light waves with a wavelength of 550 nm in the transmission wavelength range within the film thickness range. ~Tm
A green color filter whose 4F characteristic is that it has a film thickness that exhibits a transmittance in the range 1&l of 85% ax, x. Ilter.