JPS5893092A - Matrix type liquid crystal display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor device such as a TFT array having a storage capacitor, etc., in addition to active elements such as a plurality of TPTs having a plurality of gate lines and source lines. ,
The present invention relates to constituent materials of gate insulating films, storage capacitor electrodes, and dielectrics, and methods of manufacturing the same.

FIG. 1 is a cross-sectional structural diagram for explaining the configuration of a T'FT array, and FIG. 2 is a cross-sectional structural diagram for explaining the configuration of a matrix type liquid crystal display device. In the figure, (1j is a gate line, (21 is a source line, (3) is a drain electrode, (41 is T P T , +
51 is a display electrode, (6) is a storage capacitor, and (7) is a liquid crystal.

C81 is TPT7, +91 is TFT array board,
(1 (I is a transparent conductive film, (111 is a color filter, C2 is a counter substrate, (13 is a matrix type liquid crystal display device.

Conventionally, this type of device is shown in Figure 3! There was one shown in Figure 4. Fig. 3 is a plan view of the T-FT array pixel, and Fig. 4 is a cross-sectional structural diagram of the section A-A' in Fig. 3. In the figure, (l) is the gate line, and C2) is the source line. Line, (3
) is the drain electrode, 15) is the display electrode, (8) is the TFT
array, (9) is a TFT array substrate, C4 is a semiconductor,
(LS is the storage capacitor electrode, αG is the gate insulating film,
αη indicates a dielectric material.The structure of a 7-trix liquid crystal display device will be explained with reference to FIGS. 18I1 and 2. FIG. Matrix type liquid crystal display device u3
is equipped with a plurality of gate lines (1) and a source line (2) orthogonal to these gate lines, and has a T line at the intersection point, for example.
A TFT array (8) in which an active element such as P T f41 is formed and has a drain voltage tili f31 , a display electrode (5), and a signal storage capacitor (6).
A T″FTFT array substrate formed with , a transparent conductive film 11Q facing it, and color filters σ of red, green, blue, etc.
υ.

It has a structure in which a liquid crystal (7) is sandwiched between a counter substrate L13 having a side substrate L13 and a side substrate 19, α2.

Next, the conventional TFT array (8) will be explained with reference to FIGS. 3 and 4. The TPT array (8) is a TFT array substrate (91) made of an insulating substrate such as glass, on the surface of which μ, etc., which serve as gate lines il+, are formed by, for example, vapor deposition, and on top of which μ, etc., which serve as gate insulating atto, are formed. A source line (2) is formed by, for example, a sputtering method.

After μ, etc., which will become the drain electrode 13), are formed by, for example, vapor deposition, a semiconductor α, such as amorphous silicon, is formed by /lasma OVD, etc., and TF' (4) is installed. After this, the storage capacitor (6) is formed by, for example, In2O3, which becomes the storage capacitor magnetic pole (151), by a vapor deposition method, and then, as a dielectric material, for example, 5i02, etc. is formed by a sputtering method, and the display electrode (5) and the storage capacitor are formed. For example, In2O3 is formed by a vapor deposition method, and one end thereof is connected to the previously formed drain electrode (3) to complete the TFT array (8).

By the way, the characteristics required of a TFT array used in a matrix type liquid crystal display are the do L/(
4 current (ID3(OFF')) Ratio of current (ID8 (ON)) when ON (ID5(ON))
OFF) is required to be 103 or more, and it is necessary that the transconductance (gm), which indicates the sensitivity and gain of the parent TFT, be large.

Here, a semiconductor 1 that can be formed by a low-temperature process below about so"cd, such as amorphous, TP using silicon, etc.
In T, etc., this occurs near the interface between the semiconductor and the gate insulating film. The field effect mobility (-) of carriers in a semiconductor is
Compared to the case where, for example, single crystal silicon is used for this semiconductor, it is extremely small (for example, 0.5 cd / 1 se
c) It is difficult to obtain the voltage (current) necessary to drive the liquid crystal, and it is necessary to form a large TPT (with a large gate ratio of 4/1-43) and a large area.
For example, the structure has a large TF'r and a small display electrode as shown in FIG.

On the other hand, in image displays such as matrix-type liquid crystal displays.

Due to resolution constraints, the maximum size of a unit pixel is approximately 300
It is necessary to make the size smaller than micrometer Oy.

As explained above, in the conventional matrix type liquid crystal display, the installation area of TPT, which is a defect in normal display, becomes large, and the installation area of display electrodes decreases, resulting in a decrease in unit pixel area, which is a measure of display performance. Display 4 [matrix type, which has good display performance because the area ratio, that is, the aperture ratio (hereinafter referred to as aperture ratio) is reduced, and the area where a signal storage capacitor, which requires a relatively large capacity, can be formed is reduced. The drawback was that a liquid crystal display device could not be obtained.

This invention was made to eliminate the drawbacks of the conventional ones as mentioned in 1. In TFT arrays used in matrix type liquid crystal display devices, etc., μ is added to the constituent materials of gate electrodes and storage capacitor electrodes. It is characterized in that this surface is anodized and used as the gate insulating film and the dielectric of the storage capacitor.

An embodiment of the present invention will be described below with reference to FIG. 5 and FIG. 6 C-2. FIG. 5 is a partial plan view of a TFT array pixel of the present invention. FIG. 6 shows a cross-sectional structural view taken along the line A-A' in FIG. In the figure, (1) is a gate line, (2) is a source line, (3) is a drain electrode, (5) is a display electrode, and (81) is a source line.
(9) is a TFT array, (9) is a TFT array substrate, α4 is a semiconductor, (1 is a storage capacitor electrode, and (119 is a gate insulating film 1 side is a dielectric material.

Next, I will explain its structure. TFT array (81 is a TFT array substrate (9) made of a transparent insulating substrate such as glass)
First, a gate line (1) and μ, which will become the storage capacitor electrode σS, are formed on the surface of the '7'-
) line (11 and accumulated condensation - positive electrode αS:,
-For example, chemically form the anodic oxide film A1 with a 2-3% ammonium borate solution at a current density of 1 mA/cd and 200 V.
20B is formed to serve as the gate insulating film αe and the dielectric material aη of the storage capacitor. After that, it serves as the display electrode 15) and the upper electrode of the storage capacitor. For example, a transparent conductive film such as ZOM is formed by a vapor deposition method, etc. 1. Then, a source line (2),
A layer such as μ, which will become the drain electrode (3), is formed by vapor deposition or the like, and connected to one end of the previously formed display electrode (5). After this, a semiconductor I such as amorphous silicon is formed and installed by, for example, plasma OVD method, and a TFT array f8) is formed.
is completed.

As described above, the TFT array according to the present invention has a gate 4-
The insulating film and the dielectric of the storage capacitor are respectively
The surface of μ, which constitutes the gate electrode and storage capacitor electrode, is oxidized using an anodic oxidation method.

Al! An insulating film made of O3 was formed. Stable oxidation 1
11A1zos has a large dielectric constant of about 7.4 to 7.6, which is extremely large compared to 81 oz (dielectric constant of 3.1.-4) used in the conventional method. This means that the figure of merit of TPT is (''/i-'4,) (where the voice is the carrier mobility, C is the dielectric constant, t is the thickness of the gate insulating film, W is the gate width, and L is the gate ), the current when the TPT is ON and the mutual conductance gm
This shows that as a result of the increase in TPT performance and the improvement in TPT performance, it is possible to replace the TPT with a smaller and higher performance TPT compared to conventional methods. The capacitance per unit area of the storage capacitor, which requires a relatively large capacity to drive the liquid crystal, has also increased, indicating that it can be formed in a smaller area compared to conventional methods. .

On the other hand, in an image display such as a matrix type liquid crystal display, the maximum dimension of a unit pixel must be reduced to about 300 micrometers or less due to resolution constraints.

As explained above, (1) according to the present invention, the installation area of active elements such as TPT is small, (1) the installation area of display electrodes can be increased, (1) the aperture ratio, which is a measure of display performance, can be increased, and (2) the storage capacitor It is possible to form a matrix type liquid crystal display device with a small area of 1.0 mm, and a matrix type liquid crystal display device with good display quality can be obtained. Furthermore, since it can be manufactured using a low-temperature process, it is possible to use inexpensive glass substrates, etc., and there is an effect that a large-screen MAJ type liquid crystal display device can be obtained.

[Brief explanation of the drawing]

Figure 111 is a diagram for explaining the configuration of the TFT array, 1
Figure 2 is a cross-sectional structural diagram of a matrix type liquid crystal display device, Figure 3 is a partial plan view of a conventional FT array pixel, and Figure 4 is a partial plan view of a conventional FT array pixel.
Figure A-A' section cross-sectional structure diagram, Figure 5 is the TPT of the present invention.
A partial plan view of a play pixel. FIG. 6 is a cross-sectional structural diagram of the section A-A' in FIG. 5. In the figure, 11) is a gate line, α is a storage capacitor electrode, ae is a gate insulating film, and αη is a dielectric. Note that the same lines in Figure 1 indicate the same or equivalent parts. Agent Makoto Kuzuno - Figure 1 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A plurality of gate lines and a plurality of source lines perpendicular to the gate lines are provided, and a thin film transistor (hereinafter referred to as TP) is provided at the intersection point of the gate lines.
A substrate on which a TFT array consisting of active elements (referred to as T) and signal storage capacitors, etc., a transparent conductive film,
and a counter substrate on which color filters of red, green, blue, etc. are formed. In the matrix type liquid crystal display device having a structure in which liquid crystal is sandwiched between the side substrates, the gate bridge of the TFT array and the storage capacitor electrode material are made of red, and the gate insulating film and the dielectric of the storage capacitor are made of Al2O2. semiconductor devices such as TFT arrays, and matrix-type liquid crystal display devices.