JPS59172606A - Color filter - Google Patents

Abstract

PURPOSE:To obtain a blue 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 450nm 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 600nm in the attenuation wavelength range has transmittance below a specific value. The refractive index of the colored layer used for a blue 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. 450nm is selected normally as wavelength within the blue transmission wavelength range, and 600nm is selected as a representative wavelength 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 color filter, a tooth-colored fine color resolution filter used in a color image sensor and a color image sensor.

As a conventional general/more filter, a film is formed on the film plate, and this is further dyed (-1).
Organic dyed filters are known.

However, the production of these filters required a large number of man-hours and IF and j time for staining, making it inefficient.

Also, the dyed layer, that is, the colored transparent layer is relatively j9. However, even if the thickness is made uniform, there is a drawback that the transmission characteristics are non-uniform.

In addition to this, a colored layer is formed directly on the substrate by vacuum evaporation, and this colored layer is used as an optical filter element once a month.
Colorant vapor deposition is an excellent color filter that eliminates the drawbacks of the above-mentioned color filters. In addition, the cost I required for production is relatively low, and the produced colored layer has the advantage of being heat resistant. In particular, before the mordant layer or the binder, %'): l (without using !i,
Since the color separation layer is directly deposited on the substrate, it is easy to obtain the 11-color HB, which is necessary for fine color separation filters.
Since the colored layer is made up of only colored grains, the amount of light absorption necessary for the color filter can be easily obtained even if the layer thickness is approximately λ.

However, when the thickness of the colored layer is on the order of the visible light wavelength or less, the behavior of the additive layer as a light absorber 1i6 becomes similar to what is conventionally known. That is, the influence of multiple light multiple interference appears: the transmission characteristic curve with respect to change in film thickness becomes a curve that does not have a clear peak value, rather than the conventionally well-known monotonically decreasing curve. This is particularly true for the optical transmission wave IQ region.

This phenomenon complicates the spectral transmittance of color filters, so conventional methods to prevent this problem include drying a transparent layer that has the same refractive index as the colored layer, thereby making the entire layer thicker and allowing the light to shine through. Reduce the effects of interference,
Alternatively, the phase of the repulsed light can be controlled by forming a transparent layer with a refractive index equal to the colored layer with an appropriate thickness.
Shadow by Wataru K1-9. By decreasing i, ℃・ru (JP-A-Sho S
t, -3010g, etc.).

But the color A'A' K according to l1j3'')? 9'
It is difficult to select a transparent layer that satisfies c = '1, and when forming multiple color marks on the same board (board), it is difficult to satisfy the above conditions for all colors. This is extremely difficult.

The present invention has been proposed in view of the above points, and has a colored layer formed by controlling the film 1' by vacuum deposition to make use of the thin film interference effect. A color film with a large difference between the amount of light and the transmitted light tri in the optical attenuation wavelength range is defined as the color filter. .

First, we will briefly clarify the light transmission characteristics and phenomena of light blue [14], which are the premise of the embodiments of the present invention, and the conditions for obtaining the thickness of the colored layer according to the present invention.

In general, when light passes through a film with IC properties, it is the thin film and thin film that determine the transmitted light and reflected light.
'+: refractive index (n), attenuation rate (8) of each of the upper and lower layers)
, is a thin film structure CI+. Among these, the refractive index and attenuation rate are unique to the Alt 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 true light transmittance of light in the transmission wavelength range and the thickness of the colored layer.

The solid line is the I]@if knee light transmittance curve when light interference effects are considered, and the broken line is the film thickness-light transmittance curve when light interference effects are not taken into account. In the figure, the wavelength of the colored layer 1) is on the same order of magnitude or less than the wavelength of this light, and therefore the amount of light absorbed by the colored layer is small, so the interference effect is significant. Note that the properties of the film 1ζL-light transmittance curve change depending on the magnitude relationship between the refractive index of the colored layer and the refractive index of the substrate, but this figure shows that the refractive index of the substrate is higher than that of the colored layer. show.

FIG. 2 shows the relationship between the light transmittance for light in the attenuation wavelength range and the thickness of the colored layer. In this case, even if the film thickness of the colored j7'f4 is on the same order of magnitude or smaller than the wavelength of this light, the transmitted light is attenuated so sharply that there is no effect of interference.

Figure 3 shows that when the refractive index of the colored layer is higher than the refractive index of the substrate,
・Same as Figure 7 except for the conditions in 4. 7 is a diagram showing the relationship between the total light transmission and the thickness of the colored layer for light in the transmission wavelength range under the condition of η. The solid line is the film thickness-light transmission line when taking into account the optical interference effect, and the broken line is the 111 line when considering the optical interference effect. The seventh point is that the transmittance decreases due to interference effects.
It is 5y compared to the case shown in the figure.

Note that the attenuation wavelength range (C) does not show any interference effect for certain light (. Therefore, 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 The transmission half curve shows the same relationship as in FIG.

Next, conditions for setting the optimal film thickness of the colored layer used as the blue 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. Is there a possibility of selecting a film thickness that has a higher transmittance in the transmission wavelength range? In addition, as the wavelength in the archaic transmission θ branch region, 1150 nm, which is usually the center wavelength, is selected,
A wavelength of 00 nm is selected as a representative wavelength in the attenuation wavelength range.

It is assumed that FIG. 7 is a diagram showing the relationship between the film L7 and the transmittance at a wavelength of 0 nm, and that FIG. 2 is a diagram showing the relationship between the film 19 and the transmittance at a wavelength of 00 nm. The necessary conditions for a color filter are that the transmittance of a certain wavelength in the attenuation wavelength range (C) is below a certain set value.From the patent diagram that features the set value, the 1 return thickness at that time is dl. Therefore, the required film is 1!9 dl. Under these conditions, the required film thickness for the maximum transmittance at θ in the transmission wavelength range is determined by using the diagram. That is, in Figure 1, the film thickness exhibiting the maximum transmission Ha Tmax in the range above d is d2.In this way, the optimum film thickness can be set, but in reality the film thickness There will be variations in the thickness setting, and it does not necessarily have to be a film j!/! that does not necessarily show the maximum permeability.For example, if it is 'I"mln"2, the required 1 model j7 setting according to Figure 7. The range is clmin <
d (dmax).

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

Example/ First, a wafer on which a solid-state image sensor is formed, and second, an FPM
2/0 and spinner coating t) to make the film thickness 7000A. 30~ at 750~200℃ after drying
After pre-baking for 60 minutes, mask exposure of the live shape is performed using deep ultraviolet light. Furthermore, a resist mask was formed by performing a predetermined development process. Next, the entire surface of the wafer on which the resist mask has been formed is irradiated with far-ultraviolet light to soak it in a solvent. I made it J. Next, the wafer and copper phthalocyanine (C, 1,711/0) packed in a molybdenum (MO) boat were placed in a vacuum container, and the MO boat was heated at 50θ at a vacuum degree of 70~/Q TOrr.
It was heated to 0° C. to deposit copper phthalocyanine.

The thickness of the deposited film at this time was set as follows based on the above-mentioned principle. First, the refractive index (n+) and attenuation rate (k) of copper phthalonanine were calculated using a polarization analysis method.

As a result, at the wavelength in the transmission wavelength range (input -950 nm), n = 7'7, k = 0.0 /, and at the wavelength in the attenuation wavelength range (input = O00 nm), n = 2.
．． 0. = 0.3. In addition, the refractive index of Sl is n-5
(in = -'I 30 nm), n-1 (person = 6
00 nm). When the relationship between thickness and light transmittance is graphed using this value, the result is FIG. 9 (transmission wavelength range) fI3S diagram (attenuation wavelength range). (・If the transmittance in the attenuation wavelength range is set to 3% or less, the film j′-f4 becomes a
It can be seen that more than Onm is required.

Under these conditions, the film thickness at which the wavelength in the transmission wavelength range exhibits the maximum transmittance is 330 nm in Figure 9, and it can be seen that the maximum 1-h transmittance is 73. Further, when the transmittance in the transmission wavelength range is required to be higher than a certain set value, the range in which the film thickness should be set accordingly is determined by referring to Figure 11.

In the example, the deposited film thickness was set to 330 nm, which is the optimum film thickness.
And so. After a while, FPM, 2#7D (FPM210
The wafer was immersed for 3 minutes in a developer solution (manufactured by Daikin Industries, Ltd.) to dissolve the resist mask, and unnecessary portions of the deposited film were removed at 111J to form a color filter on the wafer.

For comparison, a conventional color filter, ie, a blue filter made of an organic polymer film, will be described below.

First, a gelatin layer is formed on the wafer, and dyed with Kayanol Zyanine 4B (manufactured by Nippon Kabu), which has spectral absorption characteristics similar to copper phthalocyanine. went. The relationship between film thickness and transmittance at this time is shown in Figure 4 (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 ke o o o nm, and the maximum transmittance in the transmission wavelength range is 40 factors. From this, it is clear that the color filter according to the present invention can obtain a transmittance 3% higher than that of the conventional color filter.

EXAMPLE A case will be described in which a liquid crystal color display is manufactured using a blue color filter according to the present invention. First, a 5no2 transparent electrode plate formed on a glass plate was used as a plate, and Kakin 1 and Nauphthalocyanine (C
,■. qqloo) was used to form a colored layer. Thereafter, PGMA is formed as a passivation film for the colored layer. Thereafter, a striped pattern was formed using the same procedure as in Example. In addition, the refractive index of 5no2 is n-s0°PGM'A's refractive index n=l'19,
A colored layer was formed to have a thickness of 300 nm, which was the optimum thickness determined from the film thickness-transmittance relationship diagram prepared using these A[11J]. As a result, the transmittance gθ in the transmission wavelength range is
A related five-color filter was obtained. This was pasted onto a liquid crystal board to create a liquid crystal color display.

As explained below, according to the present invention, a color filter with excellent quality can be easily obtained. Also,
Because it is a thin film, it is suitable for fine silk processing, and is particularly useful as a color filter for image pickup devices and display snow, which require a high temperature of 1141 degrees.

The substrate used in 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: Crow temporary,
Optical resin plates, resin films of gelatin, polyhinyl alcohol, hydroxyethyl cell [cose, methyl methacrylate, polyester, butyral, polyamide, etc.]. -4: It is also possible to form the color filter integrally with the object to which it is applied. Examples of substrates in this case include CCD (charge coupled (bucket bridge differential)), CID (charge injection denomination) solid-state imaging devices, cathode ray tube display surfaces, and image pickup tube receivers. ) (6th page.

Examples include liquid crystal display surfaces and color electrophotographic photoreceptors.

The hue of the colored layer can be used without any problem, even if it can be vacuum-deposited.

For example, (1) Isoisotrinon colorant Monolite Navy B V (C, 1. No. 7
3000>(2) Indathlon colorant Fastgen Super Color AO//AMA(
C. 1. No. goo) Bolimo I, Ivy Blue FR (C.1.No.4'
7g35) Lysozol Fluor G L (C.
1. N069g10) (3) Dioxazine colorant Chromophthal Violet B First Gen Super Noku Iolet BBL (C
. 1. No. 3 (4) Industhrene colorant Mikenurene Brilliant Nokuiorenoto RR (C.I.
1. No. 0010) Mikethlen Full 3G (C. 1. No. 9g'
IO) (5) l, rifconil, methane colorant)')
')-Lou y/Lou Di>3'AO (C.T.N
nq25?5:, 2) Dainichi First Blue B
OX (C.■.rlo.'l 41O'13:2) Irgalite Blue TCR (C.T.No4'J/'#;
':/) Phanaton Bluero G (C.I.NC
20.23: / ) Hallo Bonn Flame RNN
(C.T, No.','.2ro00:/) Reflex Blue 〇 (C.I, No'1
2700: / ) Alkaline Blue Toner (C
．． 1. No. 'i. 2'730: / ) Blue・
Rake 2g 372A (c.I, No//-) θF 0
:/) Reflex Blue CG (C.I,
No. '12g 00) Reflex Blue 1E1
3' (C.1.N Tsuba27waS) Final Furu D3gO (6) Phthalonanine-based copper phthalocyanine (α type) (C.1.No.74'
/40)// (β type) Metal-free phthalocyanine (C.■.No.74'
/00) Zinc phthalocyanine Iron phthalocyanine Gold phthalocyanine Chromium phthalocyanine Also, the regimen N used in the present invention may be appropriately selected and used. Typical examples (product names) of photoresists include the ``OFPR series<, t, qq. qg, goo
)"" OMR series (g/.g3.g3.g7)"
II Tl) R11 II SVR 11 11 03
R II II TPS 11 or more Tokyo Oka? ! ! floor
"KMPR-309""KMR-'7gu'7
"l'KMR-75.2""KTFR
” ” KPR 1st ” KPR-3
” ”KPR-'I”J21,
-L Manufactured by Kodak, "JSR-CBR""JS
R-CBI conversion-qO/”” JSR-CIR-70/
``Above 1] II wayc made by this synthetic comb.

at LSI ReSISt” “HP:R P
OSltlVe Resist (1011, 10 Otsu)
” ” WayCOat(HNR, HNR-L???.
NegatlVe H'R,IC,Type3IC,S
C) ``Manufactured by Hunt, ``AZ/330'' ``AZ/350J
"Oshi"Nizubray's far-UV resists include the "0DUR series (1000, 100/, 1010.
10/ri/10WR,/20) "Tokyo Oka Gen, 11. Nige0O-DUV11 made by Nobley"r(pR(20'
1.20) Made by II Hunt, “FBM/10”
FBM/20"" FPM, 2/θ11, manufactured by Nidaigin, for electron beam use, "0EBR (10θθ, 1010, /θ30.
/θ0) 11 manufactured by Tokyo Ohka, "5EL (N, Type A, Type F)" manufactured by Somar, 11 FMR (E10/, E102) "1 manufactured by Fuji Pharmaceutical,""EBR (/, 9)" manufactured by Toshi, etc. .

[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. Figure 2 shows a similar relationship for light in the attenuation wavelength range, and Figure 3 shows the relationship between the substrate and the film when the refractive index is lower than the colored layer's refractive index. Figure 9 shows the relationship between the transmittance of light in the transmission wavelength range and the film 19, and Figure 9 shows the relationship between the transmittance of light in the transmission wavelength range and the film 19. A certain light (entering a+0
Figure 4 shows the relationship between the transmittance of light (input -400 nm) and the film thickness. is a diagram of the relationship between the transmittance and film thickness of light in the transmission wavelength range (human = 130nrn) of the Kayanol-Xianin Otsu B dyed filter formed on the related 81 substrate; A certain light (
A similar relationship diagram between transmittance and film thickness (input/output 00 nm)' (
-Yes. /-/...Film thickness-light transmission curve with interference effect/-) Film thickness-light transmission curve 3 without interference effect-/...Film thickness-light transmission curve without interference effect Film thickness-light transmission curve 3-2...Film thickness-light transmission curve with interference effect Figure 1 Figure 2 Figure 5 d (nm) Figure 6

Claims (1)

[Claims] L l ) 1+! Put it on a color filter with a dye film formed on it, and select 11 rows of dyes. Film J1 showing
．． In the range f, the light wave with a wavelength ll Q nm in the transmission wavelength region has maximum transmission of only 〈+Mo or less than 1.1-TmiaX-TmaX
,
A color filter that is characterized by its own characteristics. Ilter.