JP3023729B2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having a liquid crystal layer sandwiched between a pair of substrates each having electrodes formed thereon and a plurality of color filters.

[0002]

2. Description of the Related Art Generally, in a liquid crystal display device having a color filter, it is necessary to shield light other than a display portion. Conventionally, as means for providing this light-shielding layer, JP-A-2-118
Japanese Patent Application Laid-Open No. 519-519 discloses that a light-shielding layer is provided at a boundary portion between color filters on a substrate on a color filter side. It is disclosed that a color filter is provided and this is used as a light shielding layer.

[0003] However, in the former case, if the upper and lower pixels are not accurately aligned when assembling the cells in which the upper and lower substrates are bonded, the display quality is degraded, and furthermore, the color shift is caused. A bonding device was required. There is also a problem that the size of the pixel of the lower electrode must be smaller than the size of the opening of the light shielding layer in order to prevent display unevenness.

Further, in the latter case, since the light is shielded only by the color filter, there is a problem that the image quality is deteriorated due to oblique incident light, stray light and the like.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device in which the accuracy of bonding a color filter substrate and a TFT substrate is relaxed, the light utilization factor is high, and there is no display unevenness.

[0006]

That is, the present invention provides a thin film transistor .
A transistor and an arrangement connected to the thin film transistor
Substrate provided with a pixel electrode,
A second substrate having a transparent electrode disposed opposite to the second substrate;
And a liquid crystal disposed in a gap between the first substrate and the second substrate.
In the liquid crystal display device, the first substrate is
A metal film on the film transistor with an insulating film interposed
A first light-shielding layer, and a first light-shielding layer.
Are not connected to each other, and are overlapped around the pixel electrode.
A second light-shielding layer made of a metal film,
And the second light-shielding layer are arranged except for the pixel portion.
Be Te is a liquid crystal display device according to claim.

[0007]

The present invention will be described below in detail with reference to examples.

Embodiment 1 FIG. 1 is a schematic sectional view of a liquid crystal display device of the present embodiment, and FIG. 2 is a sectional structural view of a TFT substrate in the liquid crystal display device of FIG.

In FIG. 1, a liquid crystal layer 10 is sandwiched between a TFT substrate 11 and a color filter substrate 12. T
The FT substrate 11 is made of quartz glass, Corning # 7059.
A TFT (thin film transistor) 2 made of polysilicon, amorphous silicon, or the like is formed on a glass substrate 1 made of low alkali glass typified by Corning Inc. The light-shielding layer 4 is formed in a process of forming the TFT 2 so as to cover portions other than the pixel electrode (pixel portion) 3 with a metal film such as Cr or Al. After forming the TFT 2, a protective film 5 is formed on the TFT 2.

The color filter substrate 12 is formed by forming a plurality of color filters 8, a protective film 7, and a transparent (pixel) electrode 6 on a glass substrate 9.

As shown in FIG. 2, the TFT on the TFT substrate 11
Are the source electrode 22, the gate electrode 23, and the drain electrode 2
4, an insulating film 25, and a semiconductor layer 26. The light-shielding layer 4 is provided on the pixel electrode 3 (second light-shielding layer) and on the TFT (first light-shielding).
Layer) .

In this embodiment, the incident light enters from the color filter 12 side and passes through the TFT substrate 11 side.

According to this embodiment, the overlapping portion between the light-shielding layer and the pixel electrode is narrower than when the light-shielding layer is provided on the color filter substrate, and the light utilization efficiency is improved.

Embodiment 2 FIG. 4 is a schematic sectional view of a liquid crystal display device of the present embodiment, and FIG. 5 is a sectional structural view of a TFT substrate in the liquid crystal display device of FIG.
You.

A liquid crystal display was manufactured in the same manner as in Example 1 except that an Si wafer was used as the TFT substrate 11 and an insulating film was disposed between the second light-shielding layer and the pixel electrode . still,
The Si wafer in the pixel portion was removed from the back surface by etching to make light transmissive.

[0016] creating a Si upper blade used in the TFT substrate 11 is as follows.

A P-type (10 μm) having a thickness of 300 microns
0) A single crystal Si substrate was anodized in an HF solution to form a porous Si substrate.

The anodizing conditions were as follows.

Application time: 2.6 (V) Current density: 30 (mA · cm ⁻² ) Anodizing solution: HF: H ₂ O: C ₂ H ₅ OH = 1:
1: 1 Time: 2.4 (hour) Thickness of porous Si: 300 (μm) Porosity: 56 (%) On the P-type (100) porous Si substrate thus obtained, a Si epitaxial layer was formed by a reduced pressure CVD method. Was grown with a layer thickness of 1.0 micron. The deposition conditions are as follows.

Source gas: SiH ₄ Carrier gas: H ₂ Temperature: 850 ° C. Pressure: 1 × 10 ⁻² Torr Growth rate: 3.3 nm / sec Next, a 1000 Å oxide layer is formed on the surface of the epitaxial layer. 5 on the oxidized surface
The other Si substrate on which a 2,000 Å oxide layer, a 1,000 Å oxide layer, and a 1,000 Å nitride layer were formed was overlapped and heated at 800 ° C. for 0.5 hour in a nitrogen atmosphere to form two S layers.
The i substrate was firmly bonded.

Thereafter, the bonded substrates are mixed with a mixture of 49% hydrofluoric acid, alcohol and 30% hydrogen peroxide solution (10:
6:50), and was selectively etched without stirring.
After 65 minutes, only the non-porous Si layer remains without being etched, and single-crystal Si is used as an etch stop material.
The porous Si substrate was selectively etched and completely removed. The etching rate of the non-porous Si single crystal with respect to the etching solution is extremely low, even after 65 minutes. The etching amount (several tens of angstroms) in the non-porous layer was practically negligible. In these places, 2
The porous Si substrate having a thickness of 00 μm was removed, and a single-crystal Si layer having a thickness of 1.0 μm was formed on SiO ₂ . SiH ₂ C as source gas
When 1 was used, the growth temperature had to be raised by several tens of degrees, but the accelerated etching characteristic peculiar to the porous substrate was maintained.

The Si wafer prepared by the above method is excellent in economical efficiency and has extremely excellent crystallinity which is uniform and flat over a large area.

According to this embodiment, the potential of the light-shielding layer metal is taken around the pixel array, so that the second light-shielding layer is used as a common electrode line and a storage capacitor is formed between the light-shielding metal layer and the pixel electrode. it can.

Embodiment 3 FIG. 3 is a sectional structural view of a TFT substrate in a liquid crystal display device of the present embodiment. As shown in FIG. 3 , a liquid crystal display device was manufactured in the same manner as in Example 2 except that the light shielding layer 4 was tapered.

According to this embodiment, since the step 30 around the pixel portion and its periphery is reduced, disturbance of the alignment of the liquid crystal can be prevented, and good image quality can be obtained.

[0026]

As described above, according to the present invention , TF
Since a light shielding layer is provided on the T side, the color filter substrate and the T
The bonding accuracy of the FT is relaxed, and it is possible to perform bonding with an ordinary bonding machine instead of high accuracy.

Further, the light-shielding layer can be formed by the same photo process as that of the TFT, and the alignment accuracy between the pixel and the light-shielding layer is remarkably improved. Therefore, the opening of the light-shielding layer with respect to the pixel is widened, and the light utilization rate of the liquid crystal panel is improved,
A liquid crystal display having high display quality was obtained.

Further, since a high-precision light-shielding is possible, a color tone between color filters does not interfere with each other, and a liquid crystal display device with excellent clear contrast is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a liquid crystal display device according to a first embodiment.

FIG. 2 is a sectional structural view of a TFT substrate in the liquid crystal display device of FIG.

FIG. 3 illustrates a TFT substrate in a liquid crystal display device according to a third embodiment .
FIG.

FIG. 4 is a schematic sectional view of a liquid crystal display device according to a second embodiment .

FIG. 5 is a sectional structural view of a TFT substrate in the liquid crystal display device of FIG.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mamoru Miyawaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-3-288022 (JP, A) JP-A-3 −125123 (JP, A) JP-A-3-225323 (JP, A) JP-A-3-146926 (JP, A) Japanese Utility Model Application Laid-open No. 64-4420 (JP, U) (58) Fields investigated (Int. . ^7, DB name) G02F 1/1335 G02F 1/136 500

Claims (4)

(57) [Claims] A thin film transistor and a thin film transistor
A first base having a pixel electrode arranged to be connected to a star
Plate, a transparent electrode disposed opposite to the pixel electrode.
A second substrate provided with the first substrate and the second substrate.
In the liquid crystal display device having a liquid crystal disposed in a gap, before
The first substrate has an insulating film on the thin film transistor.
When a first light-shielding layer made of a metal film is provided
Both are not connected to the first light-shielding layer, and
A second shield made of a metal film is provided at a position where the electrodes overlap each other.
An optical layer is provided, and the first light-shielding layer and the second light-shielding layer
A liquid crystal display device which is arranged except for a pixel portion . 2. The pixel electrode and the second light-shielding layer,
2. The device according to claim 1 , wherein the components are connected to each other.
The liquid crystal display device according to the above. 3. The pixel electrode and the second light-shielding layer,
The pixel electrode and the second electrode are disposed with an insulating film interposed therebetween.
2. The liquid crystal display device according to claim 1 , wherein a storage capacitor is formed between the liquid crystal display device and the light shielding layer . 4. The color filter according to claim 2, wherein the second substrate has a color filter.
4. Any of Claims 1-3 characterized by being arranged
3. The liquid crystal display device according to 1.