JPH02308227A - Active matrix substrate - Google Patents

Abstract

PURPOSE:To obtain a liquid crystal display device of high picture quality which has no display irregularity by connecting a 1st MIM element, where a lower layer electrode is connected to a signal electrode and an upper layer electrode is connected to a display electrode respectively, and a 2nd MIM element, where a lower layer electrode is connected to a display electrode and an upper electrode is connected to a signal electrode, in parallel. CONSTITUTION:An MIM element is constituted including a 1st lower layer electrode 3 connected to a signal electrode 1, a 2nd lower layer electrode 4 connected to a display electrode 2, an insulating film 7 provided on the 1st and 2nd lower layer electrodes 3 and 4, 1st upper layer wiring 5 which is pro vided on the insulating film 7 opposite the 1st lower layer electrode 3 and connected to the display electrode 2 and 2nd lower layer electrode 4, and 2nd upper layer wiring 6 which is provided on the insulating film 7 opposite the 2nd lower layer electrode 4 and connected to the signal electrode 2 and 1st lower layer electrode 3 respectively. A liquid crystal display is constituted by using this MIM type active matrix substrate to obtain the liquid crystal display device of high picture quality with good display uniformity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applied to an active matrix substrate of a liquid crystal display device, and particularly to an MIM type active matrix using an MIM (metal-insulator-metal) element as a switching element. Regarding the board.

〔overview〕

The present invention provides an MIM type active matrix substrate using an MIM element as a switching element, in which the MIM element is connected to a first M-IM element whose lower layer electrode is connected to a signal electrode and whose upper layer electrode is connected to a display electrode. and a second MIM element whose lower layer electrode is connected to the display electrode and whose upper layer electrode is connected to the signal electrode are connected in parallel, whereby a high-quality liquid crystal display device with no display unevenness can be obtained. This is how it was done.

[Conventional technology]

As shown in FIG. 3, a conventional MIM type active matrix substrate includes a lower electrode 8 connected to a display electrode 2,
It consisted of a lower layer electrode 8 and an upper layer electrode 9 facing each other with an insulating film 7 in between and connected to the signal electrode 1.

[Problem that the invention seeks to solve]

The conventional MIM type active material IJ substrate described above is an MI type consisting of a lower layer electrode 8, an insulating film 7, and an upper layer electrode 9.
There is a drawback that it is difficult to maintain the electrical symmetry and uniformity of characteristics of the M element. For this reason, when a liquid crystal display device is manufactured using a conventional MIM type active matrix substrate, there is a drawback that the display becomes uneven due to variations in the characteristics of the MIM elements, and the image quality deteriorates.

SUMMARY OF THE INVENTION An object of the present invention is to provide an MIM-type active matrix substrate that eliminates the above-mentioned drawbacks, thereby making it possible to produce a liquid crystal display device with high image quality and no display unevenness.

[Means for solving problems]

The present invention provides an active matrix substrate including a signal electrode, a display electrode, and an MIM element provided between the signal electrode and the display electrode, wherein the MIM element comprises:
a first lower electrode connected to the signal electrode; a second lower electrode connected to the display electrode; an insulating film provided on the first and second lower electrodes; a first upper layer wiring provided opposite to the first lower layer electrode and connected to the display electrode and the second lower layer electrode, respectively; and a first upper layer wiring provided opposite to the second lower layer electrode on the insulating film and the signal electrode and a second upper layer wiring connected to the first lower layer electrode, respectively.

[Effect]

In the MIM element of the present invention, the lower electrode is a signal electrode,
a first MIM in which upper layer electrodes are respectively connected to display electrodes;
The element and a second MIM element whose lower layer electrode is connected to the display electrode and whose upper layer electrode is connected to the signal electrode are connected in parallel.

Therefore, even if the characteristics of the first and second MIM elements become asymmetric due to differences in the materials of the lower and upper electrodes, manufacturing methods, and process order, the overall characteristics for one pixel are perfect. This makes it possible to create a high-quality liquid crystal display device that is symmetrical and has no display unevenness.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing essential parts of a first embodiment of the present invention.

The present embodiment is an active matrix substrate including a signal electrode 1, a display electrode 2, and an MIM element provided between the signal electrode 1 and the display electrode 2. Features include a first lower electrode 3 connected to the signal electrode 1, a second lower electrode 4 connected to the display electrode 2, and first and second lower electrodes 3.
and an insulating film 7 provided on the insulating film 7, and a first upper layer wiring 5 provided on the insulating film 7 facing the first lower layer electrode 3 and connected to the display electrode 2 and the second lower layer electrode 4, respectively. ,
The second upper layer wiring 6 is provided on the insulating film 7 to face the second lower layer electrode 4 and connected to the signal electrode 2 and the first lower layer electrode 3, respectively.

The present example was manufactured as follows.

First, the signal electrode 1, the first lower layer electrode 3 connected to the signal electrode 1, the display electrode 2, and the second lower layer electrode 4 connected to the display electrode 2 are made of ITO (indium tin oxide).
After forming 1,000 layers by sputtering, patterning is performed. Next, a silicon nitride film 1000 is used as the insulating film 7.
After forming a person by plasma CVD method, patterning is performed. Next, the first upper electrode 5 facing the first lower electrode 3 and the insulating film 7 is connected to the display electrode 2 and the second lower electrode 4, and the second lower electrode 4 and the insulating film 7 are connected to each other. A chromium film of 1000 A was formed by sputtering and then patterned so as to connect the opposing second upper layer electrode 6 to the signal electrode 1 and the first lower layer electrode 3, thereby forming the MIM of this first embodiment.
A type of active matrix substrate was manufactured.

The MIM element manufactured in this way has asymmetrical characteristics due to the difference in the materials of the lower and upper electrodes, the manufacturing method, and the order of the process, but in the present invention, two elements with opposite structures are used for one display pixel. Since they are connected in parallel, the characteristics are completely symmetrical for one display pixel. When a liquid crystal display was created using this MIM type active matrix substrate, a high quality liquid crystal display with good display uniformity was obtained.

FIG. 2 is a plan view showing essential parts of a second embodiment of the present invention.

The second embodiment has the same structure as the first embodiment, but the manufacturing method is different and was manufactured as follows.

First, the signal electrode 1, the first lower electrode 3 connected to the signal electrode 1, and the second lower electrode 4 are connected to the chromium film 100.
After forming a layer by sputtering, patterning is performed.

Next, a silicon nitride film of 1,000 layers is formed as an insulating film 7 by plasma CVD, and then patterned. Next, the display electrode 2 is connected to the second lower electrode 4, and the first upper electrode 5 is connected to the display electrode 2 and the second lower electrode 4 and faces the first lower electrode 3 with the insulating film 7 in between.
and a second upper layer electrode 6 connected to the signal electrode 1 and the first lower layer electrode 3 and facing the second lower layer electrode 4 with an insulating film 7 in between, an ITO film 1000 A is formed by sputtering and then patterned. In this manner, an MIM type active material IJ substrate of the second embodiment was manufactured.

In the second embodiment, since the signal electrode 1 and the display electrode 2 are formed separately, there is an advantage that wiring resistance of the signal electrode 1 can be prevented. In the second embodiment, the MrM characteristics for one display pixel are completely symmetrical for the same reason as in the first embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, even if the characteristics of the MIM element become asymmetric due to the difference in the materials of the lower and upper electrodes, the manufacturing method, and the order of the processes, the structure is reversed for one display pixel. Since two elements are connected in parallel, 1
It is possible to provide an MIM-type active matrix substrate whose characteristics are completely symmetrical to display pixels, and which can provide a high-quality liquid crystal display device with no display unevenness without increasing the number of manufacturing steps. The effect is great.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the main parts of a first embodiment of the present invention. FIG. 2 is a plan view showing the main parts of a second embodiment of the present invention. FIG. 3 is a plan view showing the main parts of the conventional example. l... Signal electrode, 2... Display electrode, 3... First lower layer electrode, 4... Second lower layer electrode, 5... First upper layer electrode, 6... Second upper layer electrode , 7... Insulating film, 8... Lower layer electrode, 9... Upper layer electrode. Patent Applicant NEC Corporation 4 Agent Patent Attorney Nao Takashi Ide 3: Lower level 11 & profanity 1 Talk - Laughter Example I: Shin'! @Others 4: Island-lower electrode 7: Kisuru 2: &
Indication 1i heat 5: Her upper 1 electrode 3 knees - lower 1 electric wire 6: Atsushi 2 tatami electric sleeve 2 cases 1: No. 18 @ pii 8: Lower view electric Tachibana 2: Five electrodes 9: Ekan Denkame 7: Soryokuran

Claims (1)

[Claims] 1. An active matrix substrate including a signal electrode, a display electrode, and an MIM element provided between the signal electrode and the display electrode, wherein the MIM element is provided in the signal electrode. a connected first lower layer electrode, a second lower layer electrode connected to the display electrode, an insulating film provided on the first and second lower layer electrodes, and a first lower layer provided on the insulating film. a first upper layer wiring provided opposite to the electrode and connected to the display electrode and the second lower layer electrode, respectively; and a first upper layer wiring provided on the insulating film opposite to the second lower layer electrode and connected to the signal electrode and the first An active matrix substrate comprising second upper layer wirings respectively connected to lower layer electrodes.