JPH11337932A - Color filter substrate for reflection type liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter substrate for a reflection type liquid crystal display device having color display quality of high lightness (high reflective index) and high chroma (brilliant in color) by laminating a low reflection layer, an interference prevention layer, a multi-layer film interference filter layer, and a protective film layer on a Si-chip-based substrate. SOLUTION: A color filter substrate 15 comprises a Si-chip-based substrate 11 on which elements necessary for displaying picture elements, picture element electrodes 13, etc., are formed, a low reflection layer 25, an anti-interference layer 26, a multi-film interference color filter layer 18, an overcoat layer 19, a shielding layer 21, etc. Reflection light R1 of external light I reflected by the multi-layer film interference color filter layer 18 is made to exit outside, but reflection light of the transmissive light passing through the multi-layer interference color filter layer 18 occurring on the boundary surface between the multi-layer interference color filter layer 18 and the low reflection layer 25 is reduced and prevented. Moreover, the light transmitted the anti-interference layer 26 is absorbed by the low reflection layer 25 and reflected little.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for a liquid crystal display device used in a single-panel reflective liquid crystal projection device or a liquid crystal spatial light modulator, and more particularly to a multilayer interference filter on a Si chip-based substrate. The present invention relates to a color filter substrate for a reflective liquid crystal display device having a layer formed thereon.

[0002]

2. Description of the Related Art A conventional single-panel reflective liquid crystal projection device or a liquid crystal display device used for a liquid crystal spatial modulation device has a structure in which a reflective film such as Al is provided on an electrode formed on a Si chip / base substrate. For example, a method has been employed in which transmitted light, which is separated by a color filter of a pigment dispersion method on an opposing color filter substrate, is reflected by the reflection film and emitted to the outside. FIG. 10 is an explanatory view showing an example of a liquid crystal display device used in a single-panel reflection type liquid crystal projection device in a conventional method, in an enlarged scale and in section.

As shown in FIG. 10, a liquid crystal display (8
0) is composed of a counter substrate (85), a liquid crystal (86), a color filter substrate (87) and the like. In FIG. 10, an opposing substrate (85) has an element (not shown) necessary for pixel display, a pixel electrode (83), and the like formed on Si.
i-chip based substrate (81) and Al reflective film (8
4) and the like. The color filter substrate (87) includes a glass substrate (92), a color filter layer (88), an overcoat layer (89), and a transparent electrode layer (9).
0), a light shielding layer (91) and the like.

[0004] The liquid crystal display device (80) comprises a counter substrate (8).
5) and the color filter substrate (87) are bonded together via a liquid crystal (86). The pixel electrode (83) of the counter substrate (85) and the color filter substrate (8) are bonded together.
For the alignment with the color filter layer (88) of (7), the width of the light shielding layer (91) has a margin (93). For this reason, the area of the opening (94) of the pixel becomes smaller accordingly. That is, the aperture ratio of the pixel is reduced.

In FIG. 10, external light (I) passes through a color filter layer (88) to become color light, and is reflected by an Al reflection film (8).
The light is reflected at 4), passes through the color filter layer (88) again, and is emitted to the outside as reflected light (R). In such a reflection type liquid crystal display device,
When, for example, a pigment is used as the pigment, the external light (I) passes through the color filter layer (88) to become colored light, and the performance of the colored light such as saturation and lightness (transmittance) is restricted by the pigment. The reflection performance on the opposite substrate (85) is A
l is restricted by the reflective film (84),
The reflection type liquid crystal display device used in the reflection type liquid crystal projection device does not have satisfactory performance in terms of brightness (brightness) and color vividness.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a reflection type liquid crystal display device used for a reflection type liquid crystal projection device, which is bright (high in luminance) and color. A color filter substrate for a reflective liquid crystal display device, which is a reflective liquid crystal projection device having a vivid display quality, that is, a color filter substrate for a reflective liquid crystal display device has high brightness (high reflectance), It is an object of the present invention to provide a color filter substrate for a reflection type liquid crystal display device having a high degree of color display (bright colors). It is another object of the present invention to provide a color filter substrate for a reflective liquid crystal display device which is a reflective liquid crystal display device having a high aperture ratio as the reflective liquid crystal display device.

[0007]

SUMMARY OF THE INVENTION The present invention provides a Si chip
A color filter substrate for a reflection type liquid crystal display device, comprising a base substrate and a laminated structure of a low reflection layer, an interference prevention layer, a multilayer interference filter layer, and a protective film layer. The present invention also provides the color filter substrate for a reflective liquid crystal display device according to the above invention, wherein the low reflection layer has a multilayer structure of three or more layers, and the first to nth layers from the Si chip-based substrate side. "refractive index n _1, the absorption coefficient k _1" in the layer, the first layer to the "refractive index n _n, the absorption coefficient k _n" of the n-th layer is the relationship, n _1> · · ·> n _n-1> n _n , k ₁ >> k
a color filter substrate for a reflective liquid crystal display device, wherein the _n-1> k _n, is. The present invention also provides the color filter substrate for a reflective liquid crystal display device according to the above invention, wherein the low-reflection layer has a “refractive index n _a , absorption coefficient k _a ” of _a layer on the interference prevention layer side, and the interference prevention layer. Of "refractive index n
_b , absorption coefficient k _b ”and the multilayer interference filter layer,
The relationship between the “refractive index n _c ” of the layer on the interference prevention layer side is n _b <n
_a , n _b <n _c , k _b <k _a , and a color filter substrate for a reflection type liquid crystal display device, characterized in that the thickness of the interference prevention layer is at least about 中心 of the center wavelength.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A color filter substrate for a reflection type liquid crystal display device according to the present invention will be described below based on one embodiment. FIG. 1 is a sectional view of an embodiment in which a color filter substrate for a reflection type liquid crystal display device according to the present invention is used in a reflection type liquid crystal display device. This reflection type liquid crystal display device is used for a single plate type reflection type liquid crystal projection device. FIG. 1 is an enlarged view of a part of the reflection type liquid crystal display device.

As shown in FIG. 1, a reflection type liquid crystal display device (10) comprises a color filter substrate (15) and a liquid crystal (1).
6) and a counter substrate (17). In FIG. 1, a color filter substrate (15) includes elements (not shown) necessary for pixel display and pixel electrodes (13) formed of Si.
(12) Si chip-based substrate (1
1), low reflection layer (25), interference prevention layer (26), multilayer interference color filter layer (18), overcoat layer (1)
9), and a light-shielding layer (21). The counter substrate (17) is obtained by forming a transparent electrode layer (20) on a glass substrate (22).

The reflection type liquid crystal display device (10) includes a color filter substrate (15) and a counter substrate (17) formed of a liquid crystal (16).
In the present invention, the multi-layer interference color filter layer (18) is formed on the color filter substrate (15) side, and the pixel electrode (13) and the multi-layer Since the alignment with the interference color filter layer (18) is performed on the Si chip-based substrate (11) by the photolithography method, the pixel electrode (13) and the multilayer interference color filter layer (18) are aligned. Allowance for the width of the light shielding layer (21) for alignment (2
3) is small. That is, the aperture ratio of the pixel hardly decreases.

In FIG. 1, external light (I) is split into reflected light (R ₁ ) and transmitted light (not shown) by a multilayer interference color filter layer (18), and the reflected light (R ₁ ) is sent to the outside. Injected. Further, the transmitted light is absorbed by the low reflection layer (25) via the interference prevention layer (26). The multilayer interference color filter layer (18) in the present invention is a multilayer film in which a high refractive index film and a low refractive index film are alternately formed, and the high refractive index film is made of TiO ₂ , ZrO.
_2, such as CeO _2, as the material of the low refractive index film Si
O ₂ , SiO, MgF ₂ and the like.

FIG. 2 shows a multilayer interference color filter according to the present invention.
FIG. 4 is an explanatory diagram showing an enlarged layer configuration of a filter layer (18).
You. In FIG. 2, the low reflection layer (25) and the interference prevention layer (2)
6) Multi-layer interference color filter layer (1) formed on
8) is a high refractive index film (27, 127) such as T
iO_TwoAs the low refractive index film (28), for example, SiO 2_TwoTo
It was used. This multilayer interference color filter layer
In (18), external light (I) is reflected light (R ₁) And transparent
Light (T₁). Reflective liquid crystal display
The mounting color filter substrate is a multilayer interference color filter.
The reflected light (R₁) To the outside
Reflected light (R₁) Is a reflection type liquid crystal display device (10).
It becomes the light.

FIG. 3 is an explanatory view showing the principle of a color filter substrate for a reflection type liquid crystal display device having a high lightness (high reflectivity) and high color saturation (bright color) display quality according to the present invention. It is. In FIG. 3, the low reflection layer (25) has a function of absorbing light. That is, external light (I) is split into reflected light (R ₁₎ and transmitted light (T ₁₎ in the multilayer interference color filter layer (18), spectrally separated transmitted light (T ₁₎ the interference preventing layer (26 ) Through the transmitted light (T ₂ )
When the low reflection layer (25) is reached, the low reflection layer (2)
5) absorbs the transmitted light (T ₂ ) so as not to be reflected again. As a result, the reflected light (R ₁ ) separated by the multilayer interference color filter layer (18) is emitted to the outside while maintaining the brightness and saturation without being affected by the re-reflection of the transmitted light.

FIG. 4 is an explanatory diagram showing an enlarged cross section of the low reflection layer (25) of the present invention formed on Si (12). As shown in FIG. 4, the low-reflection layer (25) is composed of three layers (31, 32, 33), and the material of the three-layer film has a refractive index and an absorption coefficient from the Si (12) side. It is set so as to incline in order. this is,
As the low reflective layer (25) of the transmitted light (T ₂₎ does not reach the transmitted light (T ₂₎ to absorb Si (12) in FIG. 3, i.e., the reflected light (R ₃₎ in FIG. 3 live It has a function like nothing.

The low-reflection layer (25) in the present invention has a multilayer structure of three or more layers. The first layer to the n-th layer from the side of the Si chip-based substrate has a “refractive index n ₁ ,
The relationship between “absorption coefficient k ₁ ” and “refractive index n _n , absorption coefficient k _n ” of the n-th layer is represented by n ₁ >> ... n _n-1 > n _n , k ₁ >
...> it is for setting k _n-1> k _n, in.

In the present invention, the interference preventing layer (26) comprises a multilayer interference color filter layer (18) and a low reflection layer (25).
This is for reducing and preventing reflected light generated at the interface between the multilayer interference color filter layer (18) and the low-reflection layer (25) when they come into direct contact with each other. 1 and 3, an interference prevention layer (26) is provided between the multilayer interference color filter layer (18) and the low reflection layer (25). The reflected light (R ₂ ) generated at the interface between the film interference color filter layer (18) and the low reflection layer (25) is reduced and prevented, and the reflected light (R ₁ ) from the multilayer interference color filter layer (18) is reduced. It has a function that does not adversely affect it.

The thickness of the anti-interference layer (26) is about １ ／ or more of the center wavelength of the corresponding multilayer interference color filter layer (18). The interference prevention layer (2)
The refractive index of 6) is the first layer of the multilayer interference color filter layer (18) in contact with the interference prevention layer (26), ie, 1 in FIG.
The refractive index of 27 (TiO ₂ ) and the third layer of the low reflection layer (25) in contact with the interference prevention layer (26), 33 in FIG.
It is desirable that the refractive index of (CrON) be smaller.

That is, in the present invention, the “refractive index n _a and the absorption coefficient k _a ” of the layer on the interference prevention layer (26) side of the low reflection layer (25) and the “refractive index” of the interference prevention layer (26). Rate n _b , absorption coefficient k _b ”and the multilayer interference filter layer (1
8), the relationship "the refractive index n _c" of the interference preventing layer (26) of the side _{layers, n b <n a, n} b <n c, k b <k a, the layer thickness of the interference preventing layer center The wavelength is set to be approximately 略 or more of the wavelength.

The anti-interference layer (26) and the low reflection layer (2)
The relationship between the refractive index and the absorption coefficient of 5) is as follows: the “refractive index n ₁ , absorption coefficient k ₁ ” of the first layer (31) of the low reflection layer (25), and the second
The “refractive index n ₂ , absorption coefficient k ₂ ” of the third layer and the “refractive index n ₃ , absorption coefficient k ₃ ” of the third layer, and the “refractive index n ₄ , absorption coefficient k ₄ ” of the interference prevention layer (26). Where n ₁ > n ₂
> N ₃ > n ₄ , and k ₁ > k ₂ > k ₃ > k ₄ .

As described above, the reflected light (R ₁ ) of the external light (I) by the multilayer interference color filter layer (18) is emitted to the outside, but the transmitted light by the multilayer interference color filter layer (18). (T ₁ ) multilayer interference color filter layer (1
The reflected light (R ₂ ) generated at the interface between 8) and the low reflection layer (25) is reduced and prevented, and the interference prevention layer (26)
The transmitted light (T ₂ ) having passed through is absorbed by the low reflection layer (25), and almost no reflected light (R ₃ ) is generated.

That is, only the reflected light (R ₁ ) having high brightness (high reflectance) and high saturation (bright color) by the multilayer interference color filter layer (18) is applied to the multilayer interference color filter layer. The light is emitted to the outside without being affected by the re-reflection of the transmitted light due to (18).

Therefore, by using the color filter substrate for a reflection type liquid crystal display device according to the present invention, a color display quality with high brightness (high reflectivity), high saturation (bright color), and light A highly efficient reflective liquid crystal display device is obtained.
In addition, by using this reflective liquid crystal display device, a reflective liquid crystal projection device having high light efficiency (high reflectivity), high color saturation (bright colors), and high light efficiency can be obtained. Become.

Further, as described above, the multilayer interference color filter layer (18) is formed on the color filter substrate (15) side, and the pixel electrode (13) and the multilayer interference color filter layer (18) are separated from each other. Since the alignment is performed on the Si chip-based substrate (11) by the photolithography method, the alignment between the pixel electrode (13) and the multilayer interference color filter layer (18) becomes accurate, and Almost no decrease in the aperture ratio. That is, by using the color filter substrate for a reflective liquid crystal display device according to the present invention, the reflective liquid crystal display device has a high aperture ratio.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. <Example 1> (Formation of low-reflection layer) Chromium, chromium oxide, and chromium oxynitride were sequentially formed as a low-reflection layer on a Si chip-based substrate on which elements, pixel electrodes, wiring, and the like were formed by a Spack method. Filmed. The respective optical constants and film thicknesses were as follows. Refractive index Absorption coefficient Film thickness (nm) Chromium 3.3 2.5 90.0 Chromium oxide 2.76 1.0 40.0 Chromium oxynitride 2.0 0.5 50.0 As shown in FIG. 5, the reflection was as low as 1% or less over the entire wavelength range.

(Formation of Interference Prevention Layer) On the Si chip-based substrate on which the low reflection layer was formed, a silicon dioxide film was formed as an interference prevention layer by the Spack method. The optical constant and the film thickness were as follows. Refractive index Absorption coefficient Film thickness (nm) Silicon dioxide 1.46 0.0 100.0

(Formation of Multilayer Interference Color Filter Layer) FIGS. 6A to 6D are explanatory views showing steps of forming a multilayer interference color filter layer in cross section. Si chip on which the low reflection layer (25) and the interference prevention layer (26) are formed.
A heat-resistant resist (Tokyo Ohka Kogyo,
Using OFPR800), the resist was applied to a thickness of 0.6 μm, pre-baked (90 ° C., 1 hour), and then exposed with a Nikon stepper with an accuracy of ± 0.3 μm. After development and post-baking, a resist pattern (61) for the first color was formed as shown in FIG.

Next, the substrate on which the resist pattern is formed
As shown in FIG. 6 (b), the first color multilayer film (62) is formed thereon.
Formed. The equipment is an EB evaporation machine made by Syncron (BMC1
050), a Cowman-type ion gun is arranged.
The material is TiO as a high refractive index film._Two, S as a low refractive index film
iO _TwoAnd 11 layers were alternately laminated under the following conditions. Ultimate vacuum pressure: 5 × 10^-FourPa, Substrate temperature: 130 ° C or less Rate IADO_Two Gas pressure TiO_Two 2.0 500 eV 2 × 10^-2Pa SiO_Two 2.0 500 eV −

Next, the substrate is immersed in a stripper (made by Shipley: Remover 1165) heated to about 90 ° C. for about 1 hour.
The resist and the multilayer film located in an area other than the first color filter layer are removed, and the first color filter layer is formed as shown in FIG.
Obtained as shown. The second color and the third color were formed by repeating the above, to obtain a multilayer interference color filter layer of three colors. The spectral characteristics of the three colors are cyan, magenta, and yellow for transmitted light, and red, green, and blue for reflected light. The layer configuration is as follows.

Color center wavelength TiO ₂ / (SiO ₂ / TiO ₂ ) ⁴ / SiO ₂ / TiO ₂ (transmission) (λ) nm cyan 740 1.0 / (1.0 / 1.0) /1.0/ 1.2 Magenta 420 4.0 / (0.5 / 2.0) /0.5/4.0 Yellow 400 0.6 / (1.0 / 1.0) /1.0/0.6 [ Numerical value 1.0 = λ / 4]

Next, a transparent organic resin (HOC-338J, manufactured by Nippon Kayaku Co., Ltd.) to be a protective film layer (63) is applied on the multilayer interference color filter layer, and is heated at 220 ° C. for 30 minutes in a clean oven. And cured under the following conditions. Thus, a color filter substrate for a reflective liquid crystal display device as shown in FIG. As shown in FIGS. 7 to 9, the spectral characteristics of the reflected light of the obtained multilayer interference color filter layer are high in lightness (high reflectivity, about 98%) and high in saturation (color is vivid). It has color display quality. In addition, the alignment between the pixel electrode and the multilayer interference color filter layer has been improved from ± 1.0 μm of the positional accuracy in the conventional method to ± 0.3 μm, and has been improved by about 5% in terms of aperture ratio. .

[0031]

According to the present invention, there is provided a color filter substrate for a reflection type liquid crystal display device having a laminated structure of a low reflection layer, an interference prevention layer, a multilayer interference filter layer and a protective film layer on a Si chip based substrate. So, high brightness (high reflectivity),
It becomes a color filter substrate for a reflection type liquid crystal display device having a color display quality with high saturation (bright colors). Further, it is possible to provide a color filter substrate for a reflection type liquid crystal display device which becomes a reflection type liquid crystal display device having a high aperture ratio.

The present invention also provides a color filter substrate for a reflective liquid crystal display device according to the present invention, wherein the low-reflection layer has a multilayer structure of three or more layers. in the n-layer, "a refractive index n _1, the absorption coefficient k ₁ 'of the first layer," refractive index n _n, the absorption coefficient k _n "th to the n-layer relationship, n _1> · · ·> n _n-1 > N _n , k _{1
>···> k n-1>} k n, a since, (high reflectance) high lightness, high saturation (colorful) of color filters for reflection type liquid crystal display device having a color display quality It becomes a substrate. Further, it is possible to provide a color filter substrate for a reflection type liquid crystal display device which becomes a reflection type liquid crystal display device having a high aperture ratio.

Further, according to the present invention, in the color filter substrate for a reflection type liquid crystal display device according to the present invention, the “refractive index n _a , absorption coefficient k _a ” of the low reflection layer on the interference prevention layer side, and the interference prevention The relationship between the “refractive index n _b , absorption coefficient k _b ” of the layer and the “refractive index n _c ” of the layer on the interference prevention layer side of the multilayer interference filter layer is n _b <n _a , n _b <n _c. , K _b <k _a , and the thickness of the anti-interference layer is approximately １ ／ or more of the center wavelength, so that color display quality with high lightness (high reflectivity) and high saturation (bright color) is obtained. And a color filter substrate for a reflection type liquid crystal display device. Further, it is possible to provide a color filter substrate for a reflection type liquid crystal display device which becomes a reflection type liquid crystal display device having a high aperture ratio.

Therefore, by using the color filter substrate for a reflection type liquid crystal display device according to the present invention, a color display quality having high brightness (high reflectivity), high saturation (bright color), and light A highly efficient reflective liquid crystal display device is obtained.
In addition, by using this reflective liquid crystal display device, a reflective liquid crystal projection device having high lightness (high reflectance), high chroma (bright color) color display quality, and high light efficiency is provided. Becomes

[Brief description of the drawings]

FIG. 1 is a sectional view in which a color filter substrate for a reflection type liquid crystal display device according to the present invention is used for a reflection type liquid crystal display device.

FIG. 2 is an explanatory diagram showing an enlarged layer configuration of a multilayer interference color filter layer.

FIG. 3 is an explanatory view showing the principle of a color filter substrate for a reflection type liquid crystal display device according to the present invention.

FIG. 4 is an explanatory diagram showing an enlarged cross section of a low reflection layer.

FIG. 5 is a reflection characteristic diagram of a low reflection layer.

FIGS. 6A to 6D are cross-sectional views showing steps of forming a multilayer interference color filter layer.

FIG. 7 is a spectral characteristic diagram of blue reflected light from a multilayer interference color filter layer.

FIG. 8 is a spectral characteristic diagram of red reflected light of a multilayer interference color filter layer.

FIG. 9 is a spectral characteristic diagram of green reflected light from a multilayer interference color filter layer.

FIG. 10 is an explanatory view showing a liquid crystal display device used for a single-panel reflective liquid crystal projection device in a conventional method.

[Explanation of symbols]

Reference Signs List 10: reflective liquid crystal display device 11, 81: Si chip-based substrate 12, 82: Si 13, 83: pixel electrode 15: color filter substrate 16, 86: liquid crystal 17: counter substrate 18: multilayer interference color filter layer 19 89, overcoat layer 20, 90 transparent electrode layer 21, 91 light shielding layer 22, 92 glass substrate 23, 93 margin of light shielding layer 24, 94 aperture of pixel 25 low reflection layer 26 Interference prevention layer 27: High refractive index film 28: Low refractive index film 31, 32, 33: Three layers of low reflection layer 61: Resist pattern for first color 62: Multilayer film of first color 63: Protective film layer 80 ··· Conventional liquid crystal display device ·············································································································· / The first layer I ... external light R of the multilayer interference color filter layer in contact with the layer 127 ... interference preventing layer, R _1, R _2, R ₃ ... reflected light T _1, T ₂ ... transmitted light

Claims (3)

[Claims] 1. A color filter substrate for a reflection type liquid crystal display device, comprising a Si chip-based substrate and a laminated structure of a low reflection layer, an interference prevention layer, a multilayer interference filter layer, and a protective film layer. 2. The low-reflection layer has a multilayer structure of three or more layers, and the first layer to the n-th layer have a “refractive index n ₁ , absorption coefficient” from the Si chip-based substrate side. k ₁ "
"Refractive index n _n, the absorption coefficient k _n" th to the n-layer relationship _{is, n 1>···> n n} -1> n n, k 1>···> k n-1>
k _n color filter substrate for a reflective liquid crystal display device according to claim 1, wherein the a. 3. The "refractive index n _a , absorption coefficient k _a " of the layer on the interference prevention layer side of the low reflection layer, the "refractive index n _b , absorption coefficient k _b " of the interference prevention layer, and The relationship of “refractive index n _c ” of the layer on the interference prevention layer side of the multilayer interference filter layer is n _b <n _a , n _b <n _c , k _b <k _a , and the thickness of the interference prevention layer is centered. 3. The color filter substrate for a reflective liquid crystal display device according to claim 1, wherein the color filter substrate has a wavelength substantially equal to or longer than １ ／.