JPS60247687A - Manufacturing method of liquid crystal display element - 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 Technical Field The present invention relates to a method of manufacturing a liquid crystal display element, and more particularly to a method of manufacturing a liquid crystal display having a structure in which an electrical signal is applied to each display electrode via an electrically insulating thin film.

BACKGROUND ART FIG. 1 shows a substrate 1 of a typical liquid crystal display device according to the prior art.
2 is a plan view of a portion of FIG. 1, and FIG. 2 is a perspective view of a portion of FIG. A plurality of first conductors 2 are patterned on the substrate 1, and a first insulating film 3 is formed on the surface with a thickness of 2000A to 400A.
It is formed with a thickness of 000A. A plurality of second conductors 4 are formed so as to selectively cover the first insulation M3, and a second insulating film 5 is formed between the first conductor 2 and the second conductor 4 at a thickness of 300A to 300A. It is formed with a thickness of 700A.

Here, the second conductor 4, the second insulating film 5, and the first conductor 2 are a nonlinear resistance element (MetaF-Insul!ator-MetaI) having a so-called metal-insulating film-metal structure.
! A device (hereinafter abbreviated as MIM device) 6 is formed.

Next, the button display electrode 7 is electrically connected to the second conductor 4.
is formed. A liquid crystal display element is manufactured through such steps, and a liquid crystal display element including the above-described MIM element 6 will be abbreviated as an MIM type liquid crystal display element hereinafter.

There are two major problems involved in manufacturing such MIM type liquid crystal display elements. The first problem is related to mask alignment accuracy. g2nd point This is a problem regarding the size of the fish eye indicator electrode 7. First, we will discuss the problem regarding the mask alignment accuracy of the first fish. As shown in the first diagram, if the arrangement pitch L1 of the display electrodes 7 is 200 μm to 600 μm, the distance 1iL2 between each display electrode 70 is 20 μm to 60 μm.
It is m. In addition, the mask alignment accuracy when forming the grooves of the second conductor 4 etc. is 1/1/2 of the width of the thinnest line to be formed.
An accuracy of 4 to 1/10 is required. Therefore, if the pinch L1 of each display electrode 7 is 200 μm to 600 μm, the mask alignment accuracy in this case is required to be 2 μm to 6 μm. The mask alignment accuracy of the otolithographic technique is W110 μm, and this accuracy is no longer suitable for manufacturing MIM type liquid crystal display elements. Therefore, high-precision 7-lithography technology, which is used in manufacturing large-scale integrated circuits, is used, which is one of the factors that increases the cost of manufacturing MIM type liquid crystal display elements.

The problem of the size of the artificial electrode 7 of the second fish will be described.

When manufacturing an MIM type liquid crystal display element using conventional technology, the first
The first conductor had to be placed between the display electrodes 7 as shown. Therefore, there is a problem in that the size of the display electrode 7 is limited.

A first object of the present invention is to provide an improved method for manufacturing a liquid crystal display element, which does not require significantly higher precision during manufacturing, improves yield during manufacturing, and reduces manufacturing costs. The second purpose is to provide an electrically insulating thin film that can increase the area of the display electrodes to increase the proportion of the area occupied by the display electrodes on the display screen, and thus has high display quality. An object of the present invention is to provide a method of manufacturing a liquid crystal display element including an intervening circuit.

Embodiment FIG. 3 is a perspective view showing a partial cross section of a liquid crystal display element according to the present invention, FIG. 41g4 is a plan view of a portion of the substrate 10 in FIG. 3, and FIG. FIG. In FIG. 3, substrates 10 and 103 are arranged parallel to each other and facing each other.

A first conductor 11 is formed on the substrate 10, and a plurality of circuits including an MIM element 12 and a display electrode 13, which will be described later, are configured on the first conductor 11.

Furthermore, an alignment film 14 is formed thereon.

A plurality of strip-shaped electrodes 15 are formed on the surface of the substrate 10a, extending in parallel in a direction perpendicular to the extending direction of the first conductor 11 (vertical direction in FIG. 4).

Each strip electrode 15 is arranged to face each display electrode 13 on the substrate 10, and each strip electrode 15 and each display electrode 13
This constitutes a dot matrix display system. An alignment film 14a is formed on the surface of the substrate 10a including the strip electrode 15. A liquid crystal 16 is sealed between the alignment films 14 and 14a.

Next, the manufacturing process of the liquid crystal display element according to the present invention will be explained using FIGS. 6 and 7. FIG. 6(1) is a plan view of a portion of the substrate 10, and FIG. 7(1) is a sectional view taken along the section line AA in FIG. 6(1).

A first conductor 11 is patterned on the substrate IO to have a thickness of 3000X to 1 μm. At this time, the first conductor 11 is made of tantalum Ta, for example.

Next, Fig. 6 (2) and the cutting plane line B in Fig. 6 (2)
Refer to FIG. 7(2a) and FIG. 7(2b), which are cross-sectional views taken from -B and CC. MIM element 12 described later
The formation region 17 is coated with a photosensitive material, for example, a photoresist 18. Next, 4J1 insulation of tantalum pentoxide Ta205 is spread on the first conductor 11 which is not covered with the photoresist 1B by an anodic oxidation method.

Next, reference is made to FIG. 6(3) and FIG. 7(3), which is a sectional view taken along the cutting plane line of FIG. 6(3). 7 mentioned above
The photoresist 18 is removed, and a second layer of T a 205 is applied to the removed portion of the first conductor 11 using an anodic oxidation method.
The insulating film 20 is formed to have a thickness of 300A to 700A.

Next, FIG. 6 (4) and the cut plane tj! of FIG. 6 (4)!
Refer to FIG. 7(4), which is a sectional view taken along the line E-E. Second
The second conductor 21 is formed to cover the insulating film 20 so as to have a rectangular shape with one side of 50 μm to 100 μm. At this time, the second conductor 21 may be made of, for example, Ta and cover the above-mentioned region 17.

Next, Fig. 6 (5) and the cutting plane line F- in Fig. 6 (5)
Refer to FIG. 7(5), which is a sectional view seen from F. The display electrode 13.covers the second conductor 21 and is arranged such that the second conductor 21 is located in the center thereof. form. At this time, the display electrode 13 is formed of, for example, indium oxide (In2O3).

In this way, a circuit on the substrate IO of the liquid crystal display element as shown in FIG. 4 is constructed. In this way, the display electrode 13 can be electrically connected to the first conductor 11 only through the MIM element 12.

In the above embodiment, mask alignment is required because:
In the step explained in FIG. 6(2), the first conductor 11
In the case where a photoresist 18 is formed on the
), the display electrode 13 is formed on the second conductor 21. 7 on the first conductor 11
The 1 m electric body 11 may be coated with the photoresist 18. Therefore, an accuracy of 30 μm to 100 μm is sufficient. Also, in the case where the display electrode 13 is formed on the second conductor 21, it is sufficient that the display electrode 13 covers the second conductor 21 and is electrically conductive, and the mask alignment accuracy in this case is 100 μm to 200 μm. Therefore, the desired degree of mask alignment accuracy can be achieved.

Further, although Ta was used as the material for forming the first conductor 11, aluminum l/ may be used instead.

Further, other photosensitive materials such as a photosensitive polyimide film may be used instead of the photoresist.

Furthermore, in the above-mentioned embodiment, the first insulating film 19 and the second insulating film 20 were formed using the oxidation method, so tantalum oxide T,! It was 2o5. However, in other embodiments, when forming using a vapor deposition technique or the like, other electrically insulating materials can be widely used.

Further, the second conductor 21 was made of Ta, but other materials were used.
, nickel, Nis, Cr, etc. may also be used.

Although the display electrode 13 is made of n203, other materials such as tin oxide S n02 or Al may also be used.

Further, in the above-mentioned embodiment, the second conductor 21 and the display electrode 13 were formed separately, but as shown in FIG.
And in the process explained in FIG. 6 (5),! The display electrode 13 can be formed to cover the second insulating film 20 instead of the second conductor 21 . In this case, vapor deposition and mask alignment are not necessary when forming the second conductor 21, so that the manufacturing process can be simplified and costs can be further reduced accordingly.

Further, in the above-mentioned embodiments, a method for manufacturing an MIM-type liquid crystal display element was described, but the present invention is not limited to an MIM-resistant liquid crystal display element, but can also be applied to a structure in which an electrical signal is applied through an electrically insulating thin film. As described above, according to the present invention, there is provided a liquid crystal display element including a structure in which an electric signal can be applied through a thin film having electrical insulation properties. In the manufacturing process, an accuracy of several 10 μm to several 100 μm is sufficient. Therefore, it is not necessary to use the high-precision 7-lithography technology used in the manufacture of large-scale integrated circuits, making it possible to reduce costs and improve the yield of manufactured liquid crystal display elements. .

In addition, since the display electrode is formed over the first conductor, the size of the display electrode is not limited by the second conductor, and therefore the display electrode can be made sufficiently large, and each display The spacing between the electrodes can also be reduced. As a result, a liquid crystal display element with high display quality can be manufactured.

[Brief explanation of the drawing]

1 is a plan view of a portion of a substrate 1 of a prior art MIM type liquid crystal display element, FIG. 2 is a perspective view showing a cross section of the sexy liquid crystal display element of FIG. 1, and FIG. 4 is a substrate of the substrate 1 of FIG. 3. FIG. 5 is a perspective view of section V of FIG. 4;
6 and 7 are diagrams showing the manufacturing process of the liquid crystal display element of FIG. 3. lO...Substrate, 11...First conductor, 12...M
IM element, 17... Formation region, 18... Photoresist, 19... First insulating film, 20... Second insulating film,
21...Second conductor agent Patent attorney Kei Nishi Figure 1 Figure 2

Claims (1)

[Claims] A plurality of first conductors are formed on a substrate, a plurality of circuits having a structure in which an electrically conductive thin film is interposed on each first conductor are connected, and a first conductor is formed on each circuit through the circuit. A method for manufacturing a liquid crystal display element, comprising forming display electrodes to which an electrical signal is applied from the body.