JPH095764A - Liquid crystal display substrate - Google Patents

Abstract

PURPOSE: To improve a wide visual field angle characteristic by forming electrodes for display and reference electrodes within the same plane parallel with transparent substrates and changing the light transmittance of a liquid crystal layer by the electric fields generated in parallel with the transparent substrates between both electrodes. CONSTITUTION: The display electrodes SL and reference electrodes CT of the liquid crystal display substrate having the display electrodes SL and the reference electrodes CT on the liquid crystal layer side surface of the one transparent substrate of the transparent substrates arranged opposite to each other via the liquid crystal layer are directly formed on the main surface of the transparent substrate and are formed parallel and flush with the surfaces of the transparent substrate without interposing an insulating film therebetween. The electric fields generated between the display electrodes SL and the reference electrodes CT are, therefore, impressed parallel with the transparent substrates, i.e., in the direction orthogonal with the thickness direction of liquid crystals. The liquid crystal molecules juxtaposed by the impression of the electric fields are flatly disposed within the plane parallel with the transparent substrates. Then, the liquid crystal molecules aligned with the major axis in the observation direction do not exist any more when the display is observed from the direction diagonal with the display surface.

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 substrate,
The present invention relates to a so-called lateral electric field type liquid crystal display substrate.

[0002]

2. Description of the Related Art A so-called lateral electric field type liquid crystal display substrate is a transparent substrate arranged to face each other with a liquid crystal layer in between, and a display electrode and a reference electrode are provided on one liquid crystal layer side of the transparent substrate. And a liquid crystal display substrate in which the light transmittance of the liquid crystal layer is changed by an electric field generated between the display electrode and the reference electrode in parallel with the transparent substrate surface.

A liquid crystal display substrate having such a structure is
Even if the display surface is observed from a direction oblique to the display surface, gradation reversal or color change does not occur, and the image quality is hardly deteriorated, so-called wide viewing angle characteristics are provided.

[0004]

However, the liquid crystal display substrate having such a structure is compared with, for example, one in which an electric field is generated in the thickness direction of the liquid crystal layer to change the light transmittance of the liquid crystal layer. As a result, a large improvement in wide viewing angle characteristics can be achieved, but it is still limited to a certain viewing angle.

The present invention has been made under such circumstances, and an object of the present invention is to provide a liquid crystal display substrate with further improved wide viewing angle characteristics.

[0006]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, of the transparent substrates arranged to face each other with the liquid crystal layer in between, a display electrode and a reference electrode are provided on one of the surfaces on the liquid crystal layer side. In the liquid crystal display substrate in which the light transmittance of the liquid crystal layer is changed by an electric field generated in parallel with the transparent substrate surface, the display electrode and the reference electrode are formed in the same plane parallel to the transparent substrate. It is characterized by that.

[0008]

In the liquid crystal display substrate having the above structure,
The display electrode and the reference electrode are formed in the same plane parallel to the transparent substrate, and there is no difference in height between them relative to the transparent substrate.

Therefore, the electric field generated between the pixel electrode and the reference electrode is applied parallel to the transparent substrate, that is, in the direction completely orthogonal to the thickness direction of the liquid crystal.

This means that the liquid crystal molecules arranged in parallel by applying an electric field are arranged in parallel in a plane parallel to the transparent substrate and are inclined with respect to the plane. Disappear.

Therefore, when the display surface is observed from a direction oblique to the display surface, there is no liquid crystal molecule whose major axis coincides with the observation direction.

Since such a state is the same even if the direction of observation is tilted to a large extent and does not change at all, the wide viewing angle characteristic can be greatly improved.

[0013]

EXAMPLES Examples of the liquid crystal display substrate according to the present invention will be described below.

Example I Substrate Configuration First, FIG. 11 is a schematic configuration diagram showing an example of a liquid crystal display device in which a liquid crystal display substrate according to the present invention is incorporated.

In FIG. 1, there is a liquid crystal display substrate 100. The liquid crystal display substrate 100 includes two transparent substrates which are arranged to face each other with a liquid crystal interposed therebetween, and one of the transparent substrates SUB extends on the liquid crystal side surface in the y direction in the drawing and is arranged in parallel in the x direction. Image signal lines DL are formed, and scanning signal lines GL that are insulated from the image signal lines DL and extend in the x direction and are arranged in parallel in the y direction are formed.

These video signal lines DL and scanning signal lines G
Each rectangular region surrounded by L constitutes a pixel region, but since this liquid crystal display substrate is of the so-called lateral electric field system as described above, in addition to the above-mentioned signal lines, a reference signal is provided. A line CM is also formed.

That is, the reference signal line CM is formed so as to extend in the x-direction and juxtaposed in the y-direction in the figure, and in each pixel area, the corresponding scanning signal line G is provided with the pixel interposed therebetween.
It is formed in parallel with L.

The detailed structure of each pixel area will be described later with reference to FIG.

Around the liquid crystal display substrate 100, a vertical scanning circuit 101 arranged to be connected to the scanning signal line GL and a video signal driving circuit 102 arranged to be connected to the video signal line DL are arranged. Has been done. The vertical scanning circuit 100 and the video signal driving circuit 102 are composed of, for example, a semiconductor device formed by a tape carrier method.

The vertical scanning circuit 101 applies a scanning signal to each scanning signal line GL to sequentially select the signal lines in the y direction, for example, and the video signal driving circuit 102 selects each signal line in accordance with the timing of the selection. A video signal is supplied to the video signal line DL.

The supply of each signal is controlled by the display information processing circuit 103. The display signal processing circuit 103 drives the vertical scanning circuit 101 via the clock circuit 14 and also drives the video signal. It is adapted to drive the circuit 103.

Further, the display signal processing circuit 103 is adapted to directly apply a reference voltage to each of the reference signal lines CM of the liquid crystal display substrate 100.

FIG. 2 is a plan view showing one of the pixel regions of the liquid crystal display substrate 100.

In the figure, the pixel region has a scanning signal line AO / GL and a reference signal line AO / GL extending in the x direction in the figure.
It is formed so as to be surrounded by CM and the video signal lines DL extending in the y direction and arranged in parallel in the x direction.

Here, the scanning signal line AO / GL and the reference signal line AO / CM are made of aluminum (Al), respectively, and the so-called anodization is performed on the entire exposed surface (including the side surface). Aluminum oxide AO is formed.
The video signal line DL is formed of a chrome (Cr) layer.

The video signal line DL is formed by stacking a silicon nitride film SiN _x and amorphous silicon a-Si formed at the intersection of the scanning signal line AO / GL and the reference signal line AO / CM below the video signal line DL. The body AS / SN is insulated via an interlayer insulating film.

Then, one of these interlayer insulating films (the upper left interlayer insulating film in the figure) is formed by the scanning signal line AO / GL.
It extends above the pixel region side, and this extending region constitutes a forming region of the thin film transistor TFT.

That is, in the formation region of the thin film transistor TFT, the laminated body AS from the video signal line DL.
/ SN, the drain electrode DT is formed to extend over the / SN, and the source electrode ST is formed to be slightly separated from the drain electrode DT.
A thin film transistor TFT having a part of L as a gate electrode is formed.

As a result, when the scanning signal (voltage) is supplied to the scanning signal line AO / GL, the silicon nitride film (functioning as a gate insulating film) in the lower layer of the stacked body AS / SN is interposed between the scanning signal line AO / GL and the upper layer. Amorphous silicon a-Si
A channel layer is formed in the layer, and a video signal from the video signal line DL receives the source electrode ST via the drain electrode DT.
Will be supplied to.

The source electrode ST is formed integrally with the display electrode SL, and the display electrode SL is arranged so as to extend in the y direction in the drawing so as to divide the pixel region into approximately two parts. In this embodiment, the display electrode SL
Is the same material as the video signal line DL, that is, chromium (C
r).

Further, the reference signal line AO / CM is provided with two reference electrodes CT formed by extending a part of them in the y direction in the drawing, and each reference electrode has the display electrode SL in between. The display electrodes SL are arranged with a relatively large distance therebetween, and are arranged in a state of being considerably close to the video signal lines DL.

In this case, since the insulating film made of aluminum oxide is formed on the surface of the reference electrode CT as described above, it can be brought close to the video signal line DL without causing an electrical short circuit. That is, the so-called aperture ratio can be improved.

The display electrode S having the above structure
An electric field that is substantially parallel to the main surface of the transparent substrate 100A is generated between L and the reference electrode CT. That is, it becomes possible to change the light transmittance of the liquid crystal in the direction perpendicular to the paper surface by this electric field, which is the reason why this method is called the lateral electric field method.

In this embodiment, one pixel has one display electrode SL.
, And the reference electrode was composed of 2 pieces, but 2 and 3 pieces each,
Furthermore, the number may be three or four.

Here, the display electrode and the reference electrode CT are formed directly on the main surface of the transparent substrate SUB without an insulating film interposed therebetween, and are formed on the same plane parallel to the surface of the transparent substrate SUB. Has been formed.

Therefore, the electric field generated between the pixel electrode and the reference electrode is applied completely parallel to the transparent substrate, that is, in the direction perpendicular to the thickness direction of the liquid crystal. .

This means that liquid crystal molecules arranged in parallel by applying an electric field are arranged in parallel in a plane parallel to the transparent substrate and are inclined with respect to the plane. Disappear.

Therefore, when the display surface is observed from a direction oblique to the display surface, there are no liquid crystal molecules whose major axis coincides with the observation direction.

Since such a state is the same even if the direction of observation is tilted to a large extent and does not change at all, the wide viewing angle characteristic can be greatly improved.

The end portion of the display electrode SL on the side opposite to the source electrode SL is formed so as to overlap the reference signal line AO / CM, and the additional capacitance C is positively formed at this overlap portion.
_{It is designed} to compose _STg . The dielectric film in this case is aluminum oxide AO formed on the surface of the reference signal line AO / CM.

As described above, since the dielectric of the additional capacitance C _STg is made of aluminum oxide AO having a relatively small film thickness, it is possible to secure a large capacitance without increasing its area. Become.

The additional capacitance is formed for the purpose of, for example, retaining the image information after the thin film transistor TFT is turned off until the next selection time.

Although not shown, a passivation film PS made of a silicon nitride film is formed on the main surface of the transparent substrate thus configured so as to cover the video signal lines DL and the like.

FIG. 1 is a block diagram showing a cross-sectional view taken along the line AA 'in FIG. As is clear from the figure,
Video signal line DL, display electrode SL, and reference electrode CM
Are directly formed on the main surface of the transparent substrate SUB.

FIG. 6 is a cross-sectional view showing a structure of a portion of the electrode terminal 10 where the scanning signal line GL extending to the periphery of the transparent substrate SUB is to be connected to the terminal of the vertical scanning circuit 101. It is a figure.

In the figure, at the end portion of the scanning signal line GL, aluminum oxide AO is not formed on the surface thereof, and ITO (which becomes the electrode terminal 10 is formed on a part of the aluminum layer exposed by this). Indium-Tin
-Oxide) film is formed.

Then, the video signal line D is covered so as to cover the aluminum layer and the ITO film which are still exposed.
A conductive layer 20 made of the same material as L is formed.

The conductive layer 20 is formed completely electrically independent of the video signal line DL, and makes the contact between the scanning signal line GL and the electrode terminal 10 made of an ITO film reliable. It has a function. That is, the scanning signal lines GL and IT made of aluminum
Only by contacting with the O film, it is possible to prevent the insulating aluminum oxide film from being formed at the interface between the ITO film and the aluminum and causing the variation in the resistance value.

In FIG. 7, the video signal line DL extending up to the periphery of the transparent substrate SUB is the video signal driving circuit 10.
It is sectional drawing which showed the structure of the part of the electrode terminal 10 used as the location connected with the terminal of FIG.

In this case, a part of the ITO film to be the electrode terminal 10 is formed to be superposed at the end of the video signal line DL. Since the video signal line DL is made of a material that is difficult to oxidize, the structure shown in FIG. 6 does not require any special measures.

FIG. 3 is a configuration diagram showing a cross section of a liquid crystal display substrate incorporating the transparent substrate configured as described above.

In the figure, transparent substrates SUB 'different from the above-mentioned transparent substrate SUB are arranged opposite to each other with the liquid crystal LC interposed therebetween.

On the liquid crystal side surface of the transparent substrate SUB ', a black matrix layer BM is formed so as to surround each pixel area, and further, in a pixel area surrounded by these black matrix layers BM. Is formed by overlapping the periphery of the color filter layer CF with the black matrix layer BM.

Then, on the main surface of the transparent substrate SUB 'on which the black matrix layer BM and the color filter layer CF are formed, a passivation film PS' made of a silicon nitride film is formed so as to cover these layers. There is. This passivation film PS 'is mainly for protecting the color filter layer CF.

In the figure, the liquid crystal (molecule) LC by the electric field E generated between the display electrode SL and the reference electrode CT.
Shows the arrangement state of.

According to the liquid crystal display substrate of this embodiment, the display electrode SL and the reference electrode CT are formed in the same plane parallel to the transparent substrate SUB, and the transparent electrode is provided between them. There is no difference in height with respect to the substrate SUB.

Therefore, the display electrode SL and the reference electrode CT are
The electric field E generated between and is applied to the transparent substrate SUB in parallel, that is, in the direction completely orthogonal to the thickness direction of the liquid crystal layer.

This means that the liquid crystals (molecules) LC arranged in parallel by the application of the electric field E are arranged in a plane parallel to the transparent substrate SUB and are inclined with respect to the plane. There is nothing to do.

Therefore, when the display surface is observed from a direction oblique to the display surface, there are no liquid crystal molecules whose major axis is aligned with the observation direction.

Since such a state is the same even if the direction of observation is tilted to a large extent and does not change at all, the wide viewing angle characteristic can be greatly improved.

In the above embodiment, the reference electrode AO
The cross section of / CM has a substantially rectangular shape as shown in FIG. 1. However, as shown in FIG. 10, the side along the longitudinal direction has a so-called tapered trapezoidal shape. It goes without saying that it is good.

In this case, when the passivation film PS is formed, there is no sharp step on the surface, and the rubbing process of the alignment film OR1 formed on the surface of the passivation film PS can be easily performed.

Further, the scan signal line AO / GL made of the same material as that of the reference electrode AO / CM is subjected to the same processing, so that the disconnection occurs due to the step break of the video signal line DL formed after that. It also has the effect of suppressing

Manufacturing Method Step 1. An aluminum (Al) film is formed on the entire main surface of the transparent substrate SUB. After that, selective etching is performed using a known selective etching method using photolithography to leave the aluminum film having the pattern shown in FIG. 4 and remove all the aluminum film in the other regions.

After that, aluminum oxide is formed on the entire exposed surface (including the side surface) of the remaining aluminum film by anodization.

In the anodization in this case, it is necessary to supply electric power to the aluminum film which is the subject of the anodization, and the supply terminal thereof is ITO as shown in FIG.
The location can be selected to be connected to the film 10 and the conductive film 20.

As a result, on the main surface of the transparent substrate SUB,
Scan signal lines AO / GL and reference signal lines AO / CM are formed.

Step 2. The scanning signal line AO / GL and the reference signal line AO / are formed over the entire main surface of the transparent substrate SUB.
Also covers the CM, silicon nitride film (SiN _X), an amorphous silicon film (a-Si), further to form a laminate by sequentially forming a high concentration impurity layer n-type Si layer. A so-called plasma C is used as a film forming method in this case.
It is suitable to carry out continuous film formation using the VD method.

The laminated body thus formed is selectively etched by a known selective etching method using a photolithography technique to leave the laminated body having the pattern shown in FIG. 5 and the laminated layers in the other regions. Remove all body. As the selective etching in this case,
By applying the dry etching method using SF ₆ , it becomes possible to carry out a rapid processing.

As a result, an interlayer insulating film for interlayer insulation between the scanning signal line AO / GL and the reference signal line AO / CM and the video signal line DL formed in the next step, and among these interlayer insulating films, A thin film transistor forming region is formed by extending one interlayer insulating film and integrally forming it.

In this case, since the laminated body has the same pattern without any difference in the pattern of each layer constituting them, the effect of reducing the number of steps is achieved.

Step 3. The transparent substrate S processed in this way
An ITO film is formed over the entire main surface of the UB. The ITO film thus formed is selectively etched by a known selective etching method using a photolithography technique to leave the electrode terminals 10 shown in FIGS. 6 and 7 and to remove the ITO film in other regions. Remove all.

Step 4. The transparent substrate S processed in this way
A chromium (Cr) film is formed on the entire main surface of the UB. The chrome film thus formed is selectively etched by a known selective etching method using a photolithography technique to leave the chrome film having the pattern shown in FIG. 2 and to remove all the chrome film in other regions. Remove.

As a result, the video signal line DL and the display electrode SL are formed and the thin film transistor TFT is formed.
In the formation region of, the drain electrode DT integrally formed with the video signal line DL and the source electrode ST integrally formed with the display electrode SL are simultaneously formed.

In this case, the conductive layer 2 shown in FIG.
0 is also formed in the same process.

Step 5. The transparent substrate S processed in this way
A silicon nitride film is formed over the entire main surface of the UB by using, for example, the CVD method. The silicon nitride film thus formed is selectively etched by a known selective etching method using a photolithography technique to expose only the electrode terminals 10.

As a result, the passivation film PS in which the portion of the electrode terminal 10 is exposed is formed.

After that, a resin film is formed on the entire main surface of the passivation film PS, and the surface is rubbed to form an alignment film OR1.

According to the manufacturing method described above, the selective etching step by the selective etching method using the photolithography technique can be completed in only 5 steps.
There is an effect that the number of manufacturing steps can be reduced and fine processing can be achieved thereby.

[Embodiment II] FIG. 13 is a view corresponding to FIG. 2 and shows another embodiment of the pattern in the pixel region.

As is clear from the figure, the pixel electrode S
L is formed to be branched into two pieces, and accordingly, three reference electrodes CT are provided so that each pixel electrode SL is positioned between them.

In this case, the so-called opening area of the pixel becomes small, but since the pixel electrode SL and the reference electrode CT can be arranged close to each other, the amount of electric field generated between them can be increased, and the liquid crystal of the liquid crystal can be increased. Driving can be facilitated.

FIG. 12 is a sectional view taken along the line BB ′ in FIG. 13. The difference from the structure shown in the embodiment I lies in the reference electrode CT (in this case, the scanning signal line AO /
The same applies to the cross section of GL).

That is, the reference electrode CT is the lower conductive film C.
The structure is such that an aluminum oxide film formed by anodization is deposited on the surface of an upper conductive film CMU made of an aluminum layer laminated with MD contained therein. In this case, the lower conductive film and the aluminum layer are each formed by applying a selective etching method using a photolithography technique.

The reason for the above configuration is that the reference electrode CT
This is a preventive measure against disconnection when forming a gap. That is, even if any of the lower conductive film or the aluminum layer is formed in the state where the disconnection occurs during the manufacturing process, the probability that the disconnection point is the same portion is small, and as a result, the reference electrode CT itself is formed. It will be possible to obtain a product that does not cause disconnection.

In the present embodiment, for example, noting that the anodized scanning signal line AO / GL and the reference electrode CT have excellent withstand voltage, the insulating film interposed between the anodized scanning signal line AO / GL and the video signal line DL is used. By eliminating the requirement, the reference electrode CT and the display electrode SL can be arranged in the same plane.

Here, the dielectric strength of aluminum oxide obtained by anodizing the aluminum layer will be described with reference to FIG. The same figure is a graph showing a so-called Weibull distribution regarding the failure result due to the dielectric strength of the scanning signal line AO / GL incorporated in the liquid crystal display substrate. It is known that the larger the slope of each plot of this graph, the more reliable it is.

From this, it can be seen that the dielectric strength of aluminum oxide is good.

Although aluminum is used as the material of the reference electrode CT and the scanning signal line AO / GL in each of the above-mentioned embodiments, the material is not limited to this, and for example, tantalum or its alloy may be used. It goes without saying that it is good. Even in this case, the oxide film can be formed by anodizing.

It can be seen that the dielectric strength is extremely good as shown in FIG. 9 which is a graph corresponding to FIG.

Furthermore, in the above-mentioned embodiment, the insulating film is formed on the surface of the scanning signal line AO / GL and the reference electrode CT by anodization, but the present invention is not limited to this, and for example, plasma oxidation may be performed. The same effect can be obtained by using the method.

[0092]

As is apparent from the above description,
According to the liquid crystal display substrate of the present invention, the wide viewing angle characteristics can be further improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of one transparent substrate constituting a liquid crystal display substrate according to the present invention.

FIG. 2 is a plan view showing an embodiment of a pixel area pattern on a liquid crystal display substrate according to the present invention.

FIG. 3 is a sectional view showing an embodiment of a liquid crystal display substrate according to the present invention.

FIG. 4 is a process drawing showing an embodiment of the method of manufacturing a liquid crystal display substrate according to the present invention.

FIG. 5 is a process chart showing an embodiment of a method for manufacturing a liquid crystal display substrate according to the present invention.

FIG. 6 is a cross-sectional view showing an example of a terminal electrode connected to a scanning signal line of a liquid crystal display substrate according to the present invention.

FIG. 7 is a cross-sectional view showing an example of a terminal electrode connected to a video signal line of a liquid crystal display substrate according to the present invention.

FIG. 8 is a graph showing an effect when anodized aluminum is used as a reference electrode of a liquid crystal display substrate according to the present invention.

FIG. 9 is a graph showing an effect of using anodized tantalum as a reference electrode of a liquid crystal display substrate according to the present invention.

FIG. 10 is a sectional view showing another embodiment of the liquid crystal display substrate according to the present invention.

FIG. 11 is a block diagram showing an embodiment of a liquid crystal display device incorporating a liquid crystal display substrate according to the present invention.

FIG. 12 is a sectional view showing another embodiment of the liquid crystal display substrate according to the present invention.

FIG. 13 is a plan view showing another embodiment of the liquid crystal display substrate according to the present invention.

[Explanation of symbols]

100: liquid crystal display substrate, AO / GL: scanning signal line,
SL: display electrode, CT: reference electrode.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keiichiro Ashizawa, 3300 Hayano, Mobara-shi, Chiba, Hitachi, Ltd. Electronic Device Division (72) Inventor Masahiro Yanai, 3300, Hayano, Mobara, Chiba Hitachi, Ltd. Electronic Device Business Department

Claims (13)

[Claims] 1. A display substrate and a reference electrode are provided on a surface of one of the transparent substrates facing each other with a liquid crystal layer in between, and a display electrode and a reference electrode are provided. In the liquid crystal display substrate in which the light transmittance of the liquid crystal layer is changed by an electric field generated in parallel with the transparent substrate surface, the display electrode and the reference electrode are formed in the same plane parallel to the transparent substrate. A liquid crystal display substrate characterized in that 2. The liquid crystal display substrate according to claim 1, wherein the display electrode and the reference electrode are directly formed on the transparent substrate without interposing another material layer. 3. The liquid crystal display substrate according to claim 1, wherein the reference electrode formed on the transparent substrate is covered with an insulating film formed by oxidizing the material. 4. The liquid crystal display substrate according to claim 3, wherein the reference electrode formed on the transparent substrate has an insulating film oxidized by anodization formed on the surface thereof. 5. The liquid crystal display substrate according to claim 4, wherein the material of the reference electrode is aluminum or its alloy. 6. The liquid crystal display substrate according to claim 4, wherein the material of the reference electrode is tantalum or an alloy thereof. 7. A scanning signal line and a reference extending in the x direction and juxtaposed in the y direction on one liquid crystal layer side surface of transparent substrates arranged to face each other with a liquid crystal layer interposed therebetween. A signal line, a video signal line extending in the y direction and juxtaposed in the x direction, a thin film transistor which is turned on by the supply of the scanning signal from the scanning signal line, and the image through the thin film transistor which is turned on. A display electrode to which a video signal from the signal line is supplied, and a reference electrode formed facing the display electrode and connected to the reference signal line are provided, and between the display electrode and the reference electrode. In the liquid crystal display device in which the light transmittance of the liquid crystal layer is changed by the electric field generated in parallel with the transparent substrate surface, the display electrode and the reference electrode are formed in the same plane parallel to the transparent substrate. Are The liquid crystal display substrate, wherein the door. 8. The liquid crystal display according to claim 7, wherein the scanning signal line, the display electrode, and the reference electrode are directly formed on the transparent substrate without interposing another material layer. substrate. 9. The liquid crystal display substrate according to claim 7, wherein the scanning signal line and the reference electrode formed on the transparent substrate are covered with an insulating film formed by oxidizing the material. 10. The scanning signal line and the reference electrode formed on the transparent substrate are formed with an insulating film oxidized by anodization on the surface thereof.
The liquid crystal display substrate described. 11. The liquid crystal display substrate according to claim 10, wherein the material of the scanning signal line and the reference electrode is aluminum or its alloy. 12. The liquid crystal display substrate according to claim 10, wherein the material of the scanning signal line and the reference electrode is tantalum or an alloy thereof. 13. A sequential laminate of an insulating layer and a semiconductor layer, which constitutes an interlayer insulation of a video signal line with respect to a scanning signal line and a reference signal line and a portion which is formed as an extension of this interlayer insulation film and serves as a formation region of a thin film transistor. 10. The liquid crystal display substrate according to claim 9, wherein the liquid crystal display substrate is formed of a sequentially laminated body having the same pattern.