JPH10305369A - Liquid crystal display and manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active matrix liquid crystal display and its manufacturing method, which concurrently prevent problems of the open area ratio reduction caused by the displacement of an active matrix substrate and an opposed substrate and the signal delay in wiring and the capacitive coupling between wiring and display electrodes, and also supply a TFT of high quality and reliability. SOLUTION: An active matrix substrate is made up of a glass substrate 1 which a light blocking layer 3 serving concurrently as a black matrix, and an organic insulating layer 4 with a thickness of 1.0-5.0 μm, an inorganic insulating layer 5 of at least >=0.01 μm covering whole underneath portion, and a forward staggered TFT 20, a source bus wiring 6, a gate bus wiring, and a transparent pixel electrode 10 in a matrix form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device and a method of manufacturing the same, and more particularly to an active matrix type liquid crystal display device using a thin film transistor as a switching element and a method of manufacturing the same.

[0002]

2. Description of the Related Art Known documents relating to the technology related to the present invention include, for example, those described below.

(1) JP-A-8-101400,
(2) JP-A-7-120784 and (3) DJ
Perettie, MJRadler, and T. Takahashi, The Daw
Chem. Co., ASIA DISPLAY '95, S31-3 (P.72
1), "Benzocyclobutene as a Planarization Overc
oat for Flat Panel Displays ".

In recent years, liquid crystal display devices have been widely applied to information terminal devices, AV (audio and video) devices, etc. due to various advantages such as thinness, light weight, and low power consumption. In particular, an active matrix type liquid crystal display device using a TFT (thin film transistor) as a switching element is capable of displaying a clear image and a high-speed display without depending on the number of scans in principle. Used for fine video displays.

The active matrix type liquid crystal display device is roughly divided into an active matrix substrate on which a plurality of transparent pixel electrodes and TFT elements formed for each pixel electrode are arranged in a matrix, and a common transparent electrode on the entire surface. And a liquid crystal layer sealed between both substrates. Polarizing plates are arranged and formed on the outer surfaces of both substrates such that their transmission axes are perpendicular to each other. The transmission axis and the orientation direction of the liquid crystal molecules near both substrates are arranged so as to be substantially parallel to each other, so that a state in which the liquid crystal molecules are twist-oriented at substantially 90 ° in the layer is formed.

In the active matrix substrate, the TFT elements arranged for each pixel are connected by vertical and horizontal wirings to form a TFT array. The horizontal line is TF
The scanning line is connected to the gate of T, and the vertical line is connected to the source of the TFT to serve as a signal line (video signal line). The drain, which is the third terminal of the TFT, is connected to the pixel electrode and plays the role of operating the liquid crystal.

When a voltage is applied to a scanning line, that is, a gate electrode, all TFT switches in the row are turned on, and all vertical signal lines and pixel electrodes connected to the drain from the source electrode to the drain through the respective switches respond to the signal. Accumulate stored charge immediately. Since the pixel electrode is a capacitor using liquid crystal as a derivative between the pixel electrode and the common electrode, it is possible to accumulate charges.

When the operation shifts to the next scanning line, that is, when the gate voltage becomes low, the TFT switch is turned off. Therefore, the accumulated charge is held in each pixel electrode until the next voltage is applied to the gate electrode. Is done. In accordance with the stored voltage, the alignment direction of the liquid crystal molecules is changed, and the transmitted light is modulated by the change in the optical rotation of the liquid crystal layer.

By controlling light modulation for each pixel, an image can be displayed as a whole.

When a forward stagger type TFT having a gate disposed above a semiconductor layer is used as a TFT, there is an advantage as described in, for example, Japanese Patent Application Laid-Open No. 8-101400 (1). Japanese Patent Application Laid-Open No. 8-101400 proposes a configuration of a liquid crystal display device using a forward stagger type TFT, which improves the aperture ratio and increases the auxiliary capacitance to improve the voltage holding characteristic. Have been. FIG. 5 is a plan view, and FIGS. 6 and 7 are cross-sectional views of the liquid crystal display device proposed in Japanese Patent Application Laid-Open No. 8-101400. Referring to FIG. 5 to FIG.
The liquid crystal display device described in JP-A-101400 will be described below.

An auxiliary capacitance electrode 19 made of a transparent conductive material is formed on the entire surface of the transparent substrate 1, and a light shielding layer 3 also serving as a black matrix is formed thereon. An interlayer insulating layer 5 is formed on the entire surface covering the auxiliary capacitance electrode 19 and the light shielding layer 3, and on the interlayer insulating layer 5,
A gate bus line 7 and a source bus line 6 are arranged to cross each other, and a source electrode 8 and a drain electrode 9 are arranged close to each other at the intersection of the two lines. The layer 12 and the gate electrode 14 are sequentially laminated to form a TFT 20.

A display electrode 10 is formed in a region surrounded by the gate bus wiring 7 and the source bus wiring 6.
Is formed around the periphery of the display electrode 10 and partially overlapped with the peripheral edge of the display electrode 10.

That is, the light-shielding layer 3 covers the entire area except the opening,
That is, the structure is also provided in the region below the gate bus wiring 7 and the source bus wiring 6.

A colored layer 2 and a light-shielding layer 18 are provided on a transparent substrate 17 which is opposed to the substrate 1 with the liquid crystal layer 15 interposed therebetween.
Are formed, and a common electrode 16 made of a transparent conductive layer is formed on the entire surface covering them. The light-shielding layer 18 is formed so as to be smaller than the light-shielding layer 3 on the substrate 1 side, that is, to have a larger opening.

In this structure, the aperture ratio is improved by making the light shielding layer function as a black matrix.

Normally, since the black matrix is formed on the counter substrate side, it is necessary to take a large margin in consideration of a deviation at the time of bonding with the active matrix substrate, and there is a problem that the aperture ratio is reduced.

A sectional view of the source bus wiring portion at this time is shown in FIG.
As shown in FIG.

Since the displacement between the two substrates is about 5 to 10 μm, in order to block unmodulated light leaking from the periphery of the display electrode 10, the overlapping portion of the display electrode and the light-shielding layer (portion indicated by P 2 in FIG. 9) Is required to be 10 μm or more. Therefore, a structure in which the portion of the display electrode whose peripheral edge is 10 μm or more is not effectively used is obtained.

On the other hand, Japanese Patent Application Laid-Open No.
In the device described in Japanese Patent Application Laid-Open Publication No. H11-270, the black matrix is formed on the same active matrix substrate side as the display electrode, so that only the deviation (1-2 μm) during the exposure alignment in the photolithography technique needs to be considered. The overlapping portion (the portion indicated by P1 in FIG. 7) is 2 μm.
m, which improves the aperture ratio.

[0020]

However, in the liquid crystal display device described in the above-mentioned Japanese Patent Application Laid-Open No. 8-101400,
There are the following problems.

As can be seen from FIG. 7, the light shielding layer 3, the source bus wiring 6, and the display electrode 10 form a capacitor C with the interlayer insulating layer 5 interposed therebetween.

The voltage applied to the source bus line 6 fluctuates at any time in accordance with the brightness to be displayed and, in order to prevent the burn-in of the liquid crystal, normally, the AC drive is performed so that the write polarity of the display electrode 10 is inverted for each line. It has become.

Therefore, if the capacitance of the capacitor C is large, the writing potential of the display electrode 10 fluctuates due to the capacitive coupling between the source bus line 6 and the display electrode 10, which causes display defects including crosstalk and flicker. .

In the liquid crystal display device described in JP-A-8-101400, a silicon oxide film is formed as the interlayer insulating layer 5 to a thickness of 0.7 to 1.0 μm.
Since the relative dielectric constant of the silicon oxide film is about 4.0, when the film thickness is about 0.7 μm, the capacitance is negligible with respect to the liquid crystal capacitance (the capacitance formed by the display electrode 10 and the common electrode 16). In this case, the size becomes impossible, and the above-mentioned problem of display failure occurs.

At the same time, there is a problem of signal delay on the wiring. The signal supplied to the wiring has a signal delay determined by a time constant defined by the wiring resistance and the wiring parasitic capacitance. If the parasitic capacitance on the wiring increases,
Since the time constant increases accordingly, the rise and fall characteristics of the signal deteriorate, and it becomes difficult to transmit a normal signal within a predetermined time.

If the capacitance of the gate bus wiring 7 or the source bus wiring 6 and the light shielding layer 3 is large,
Such a problem of signal delay also occurs.

Further, as in the apparatus described in the above publication, a silicon oxide film is formed by a plasma CVD method to a thickness of 0.5 μm.
If an attempt is made to form more than m, the following problem occurs.

First, since it takes 10 minutes or more to form a film, the throughput of the product is greatly reduced, and the production cost is greatly increased, including the use of expensive equipment.

Further, the film thickness and the film quality in the substrate become extremely uneven, which leads to an increase in defects such as display unevenness and a decrease in yield.

Further, the following problem can be considered. As the definition of the display screen increases, the width of the source bus lines 6 and the distance between the source bus lines 6 and the display pixels 10 need to be reduced. Then, as shown in FIG. 7, the colored layer 2 and the light shielding layer 18 are formed on the counter substrate side, but the end of the light shielding layer 3 formed on the active matrix substrate side and the light shielding layer formed on the counter substrate side are formed. 22 (Fig. 7
(Indicated by P3 in FIG. 3) cannot be formed by 10 μm.
Therefore, in consideration of the misalignment of the two substrates of 5 to 10 μm, it cannot be said that the opening is determined only by the light shielding layer 3 formed on the active matrix substrate side.

As a method for solving the problems of capacitive coupling, signal delay and film formation among these problems, for example, as described in Japanese Patent Application Laid-Open No. Hei 7-120784, an interlayer insulating layer is formed by an organic insulating method. The technology of forming a film can be applied. FIG. 8 shows the cross-sectional structure.

Referring to FIG. 8, the TFT on the transparent substrate 1
The light shielding layer 3 is formed only at the formation position, the polyimide film 4 covering the light shielding layer 3 and the transparent substrate 1 is formed, the source electrode 8 and the drain electrode 9 are formed on the polyimide film 4, and the source electrode 8 and the drain electrode 9 are formed. Ohmic contact layers 21 are formed at the ends of the respective layers. Further, a semiconductor layer 11 is formed so as to straddle both ohmic contact layers 21 formed at ends of the source electrode 8 and the drain electrode 9, a gate insulating layer 12 is formed on the semiconductor layer 11, and the whole is further formed. A gate insulating layer 13 is formed to cover. Next, the semiconductor layer 11 is formed on the gate insulating layer 13.
The gate electrode 14 is formed at a position corresponding to the upper part.

Since an organic insulating film such as polyimide is in a liquid state before firing, it can be applied by a spin coater or the like. Therefore, the film thickness can be controlled at 1 to 5 μm. Of course, it can be controlled to 1 μm or less and 5 μm or more. Further, the film thickness and film quality can be formed substantially uniformly over the entire surface of the substrate.

When this organic insulating film is applied to the interlayer insulating layer 5 of the device described in Japanese Patent Application Laid-Open No. Hei 8-101400 shown in FIG. 6, the relative dielectric constant of the polyimide film is about 3.0, Since the thickness can be formed to be 2 μm or more, the capacitance formed between the light shielding layer 3 and the source bus wiring 6 and between the display electrode 10 can be reduced. Can be controlled to be negligibly small. In addition, since the parasitic capacitance of the wiring can be reduced, the problem of signal delay can be solved. Further, it is possible to form an insulating film having a thickness of several μm without sacrificing throughput or yield.

However, as shown in FIG.
The device described in Japanese Patent No. 20784 has the following problem.

That is, the polyimide film 4 and the semiconductor layer 11
Are in contact with each other, but at the interface,
The diffusion of carbon and hydrogen molecules in the polyimide film 4 into the semiconductor layer 11 causes deterioration in transistor characteristics such as an increase in conductivity of the semiconductor layer 11 near the interface and a shift in the threshold voltage of the transistor. .

Although polyimide is used for the gate insulating layer 13, since a small amount of ions are always contained in the organic film, when such an organic film is used as the gate insulating film, the reliability of the transistor is reduced. It causes a decline.

Further, since the light shielding layer 3 is formed only at the TFT position, the black matrix has a conventional structure formed on the counter substrate side, and has a low aperture ratio.

As described above in detail, the conventional technique has a problem that the aperture ratio is inevitably reduced due to the displacement that occurs when the active matrix substrate and the counter substrate are overlapped.

Further, there are problems of capacitive coupling between the wiring and the pixel electrode and signal delay on the wiring. To solve the problems, it is necessary to form an interlayer insulating layer thickly, and the time required for the process is increased. This not only increases the manufacturing cost, but also causes a problem that the uniformity of the film is significantly reduced.

Further, even if a solution using an organic insulating film as an interlayer insulating layer is applied, a problem that transistor characteristics are deteriorated occurs.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to avoid a decrease in an aperture ratio due to a displacement that occurs when an active matrix substrate and a counter substrate are superimposed, and to reduce wiring. Liquid crystal display device capable of solving the problems of capacitive coupling between a pixel and a pixel electrode and signal delay on wiring without sacrificing productivity or quality and stably producing transistors with excellent characteristics And a method for manufacturing the same.

[0043]

In order to achieve the above object, a liquid crystal display device according to the present invention comprises an active liquid crystal display comprising a plurality of pixel electrodes and a plurality of forward staggered TFT elements each for driving the pixel electrodes arranged in a matrix. A matrix substrate, a counter substrate having a transparent electrode, and a liquid crystal layer sealed between both substrates, wherein the active matrix substrate is a light-shielding layer also serving as a black matrix on a transparent insulating substrate, An organic interlayer insulating layer formed so as to cover the entire surface thereof, an inorganic interlayer insulating film thinly formed thereon, a plurality of transparent pixel electrodes arranged in a matrix thereon, and the plurality of transparent And a staggered TFT element for driving each pixel electrode.

In the present invention, the active matrix substrate further includes a structure in which a colored layer is formed between the transparent insulating substrate and the organic interlayer insulating layer.

In the present invention, the organic interlayer insulating layer is preferably selected from high molecular compounds such as polyamide, polyimide, acrylic resin and silicone resin, and is preferably formed to a thickness of 1.0 to 5.0 μm. And an organic insulating film.

In the present invention, the inorganic interlayer insulating layer is preferably formed by a sputtering method or a plasma CVD method, and is preferably formed of a silicon oxide film or a silicon nitride film having a thickness of at least 0.01 μm. It is characterized by having.

In the present invention, the organic interlayer insulating layer preferably has a thickness of about 1.0 to 5.0 μm.
And the inorganic interlayer insulating layer is formed by denaturing the surface of the organic insulating film by plasma treatment in an oxygen atmosphere. It is made of a silicon oxide film having a thickness of 0.01 μm or more.

Further, in the present invention, the light-shielding layer is superimposed on the entire area between the plurality of transparent pixel electrodes and on the periphery of the transparent pixel electrode, preferably in an area of 1.0 to 2.0 μm. It is characterized by being provided.

Next, in the method of manufacturing a liquid crystal display device according to the present invention, the step of forming the active matrix substrate includes the following steps:
(A) a step of forming a light-blocking layer also serving as a black matrix on a transparent insulating substrate; (b) a step of forming an organic interlayer insulating layer on the transparent insulating substrate so as to cover the entire surface; and (c) a thin inorganic layer thereon. Forming an interlayer insulating layer; and (d) arranging and forming a plurality of transparent pixel electrodes thereon and a staggered TFT element for sequentially driving the plurality of transparent pixel electrodes in a matrix. It is characterized by having.

In the step (b) and the step (c), a polymer compound having a siloxane skeleton is formed as an insulating film by spin coating and thermal baking, and then the insulating film is subjected to plasma treatment in an oxygen atmosphere. A step of transforming only the surface into a silicon oxide film.

[0051]

Embodiments of the present invention will be described below. In the liquid crystal display device of the present invention, in a preferred embodiment, the active matrix substrate has a light-shielding layer also serving as a black matrix formed on a glass substrate, and a predetermined thickness, preferably approximately a thickness, is formed thereon. An organic interlayer insulating layer having a thickness of 1.0 to 5.0 μm and an inorganic interlayer insulating layer having a thickness of preferably at least 0.01 μm are formed on the organic interlayer insulating layer so as to cover the entire surface. A source bus wiring, a gate bus wiring, and a transparent pixel electrode are formed in a matrix.

According to the embodiment of the present invention, the black matrix is formed on the active matrix substrate side, which has been a problem when these are conventionally formed on the counter substrate side. It is possible to avoid a decrease in aperture ratio due to misalignment of the substrates.

According to the embodiment of the present invention, the interlayer insulating layer formed between the light-shielding layer and the source bus wiring and the pixel electrode is formed by spin-coating and thermally firing an organic polymer compound. It can be formed as a low dielectric constant insulating layer having a uniform film thickness and quality to a thickness of several μm. As a result, it is possible to control the capacitance coupling between the source bus wiring and the pixel electrode and the occurrence of signal delay on the wiring to be small enough to be ignored.

Further, according to the embodiment of the present invention, by forming a thin silicon oxide film on the organic insulating film, the semiconductor layer has a structure protected by the inorganic insulating layer. It is possible to manufacture a TFT having various characteristics.

[0055]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; For the sake of simplicity, parts that are not directly related to the present invention, such as auxiliary capacitors, electrode lines for auxiliary capacitors, and terminal structures, are omitted as appropriate.

[Embodiment 1] FIG. 1 is a plan view showing a part of a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a schematic sectional view taken along line AA of FIG. FIG. 3 is a diagram schematically showing a cross section taken along line BB of FIG.
An embodiment of the present invention will be described below with reference to FIGS.

In the active matrix substrate, first, a light-shielding layer 3 which is made of chromium, chromium oxide, a black colored resin and the like and also serves as a black matrix is formed on a transparent insulating substrate 1, and the light-shielding layer 3 covers the entire substrate. An organic interlayer insulating layer 4 made of a transparent and low dielectric constant organic insulating film is formed, and an inorganic interlayer insulating layer 5 made of silicon oxide or the like is formed thereon.
A source bus line 6, a transparent pixel electrode 10, and a TFT (thin film transistor) 20 are formed, and an alignment film (not shown) is further formed thereon.

Here, the inorganic interlayer insulating layer 5 must have a thickness of at least 0.01 μm or more in order to prevent diffusion of carbon and hydrogen molecules existing in the underlying organic interlayer insulating layer 4. is required.

In the active matrix substrate, as shown in FIG. 1, a plurality of gate bus lines 7 made of chromium, tantalum, molybdenum, aluminum, etc.
Are provided in parallel with each other, and the IT
O (Indium-Tin-Oxide) or IT
A plurality of source bus lines 6 made of O / chromium, ITO / molybdenum, or the like are provided in parallel with each other.

At each intersection of the gate bus line 7 and the source bus line 6, a TFT 20 is formed as a switching element.
Are provided, and the source electrode 8 of the TFT 20 is provided branching from the source bus wiring 6. A transparent pixel electrode 10 made of ITO or the like is connected to the drain electrode 9 of each TFT 20. The light-blocking layer 3 also serving as a black matrix is provided so as to overlap the entire area between the transparent pixel electrodes 10 and the area of the periphery of the transparent pixel electrode 10 of 1.0 to 2.0 μm.

The structure of the TFT 20 is as follows.

Referring to FIG. 2, first, a source electrode 8 and a drain electrode 9 made of a transparent conductive film such as ITO are formed on an interlayer insulating layer 5, and a pixel electrode 10 is connected to the drain electrode 9. I have. On top of that, the source electrode 8
Amorphous silicon semiconductor layer 11 is formed so as to be connected to both of and drain electrode 9. A gate insulating layer 12 made of silicon nitride or the like is formed on the semiconductor layer 11, and a gate insulating layer 13 made of silicon nitride or the like is formed thereon so as to cover the entire substrate. Electrode 14 made of, for example, tantalum, molybdenum, aluminum, etc.
It is formed at a position corresponding to the upper part.

The opposite substrate, which is disposed opposite the active matrix substrate with the liquid crystal layer interposed therebetween, has a transparent insulating substrate 17 made of glass or the like, on which a colored layer 2 made of a photosensitive resin in which a pigment is dispersed is formed. A common electrode 16 made of a transparent conductive film such as ITO is formed so as to cover the whole, and an alignment film (not shown) is further formed thereon.

This liquid crystal display device can be manufactured as follows.

First, a film of chromium, chromium oxide, or the like is formed on the glass substrate 1 to a thickness of 0.1 to 0.4 μm by a sputtering method, and then patterned into a predetermined black matrix shape by photolithography. Thus, the light shielding layer 3 is formed.

Subsequently, a transparent and low dielectric constant (relative dielectric constant of 2.0 to 3.0) made of polyimide resin, silicon resin or the like.
The thermosetting resin 0) is spin-coated to a thickness of 1 to 5 μm and thermally baked to form the organic interlayer insulating layer 4. Specifically, first, a viscous liquid prepolymer (precursor polymer)
Is applied on a substrate, then stretched by a spin coater so that the film thickness of the prepolymer becomes substantially uniform over the entire surface of the substrate, and then held in a firing furnace at, for example, 250 ° C. for 30 minutes to cure the prepolymer. By this, the organic interlayer insulating layer 4
To form

Next, the silicon oxide film is formed by sputtering or plasma CVD, preferably from 0.01 to 0.1 μm.
Then, an interlayer insulating layer 5 is formed.

After forming a film of chromium, molybdenum or the like to a thickness of 0.1 to 0.4 μm thereon by sputtering,
The source bus wiring 6 is formed by etching into a predetermined shape using a photolithography technique. The step of forming the source bus wiring 6 can be omitted in some cases.

Subsequently, a transparent conductive film made of ITO or the like is formed thereon by sputtering to a thickness of 0.01 to 0.4 μm, and then etched into a predetermined shape by photolithography. As a result, the source bus wiring 6, the source electrode 8, the drain electrode 9, and the pixel electrode 1
0 is formed.

Thereafter, the substrate is subjected to a plasma treatment in a phosphine gas, and then the amorphous silicon to be the semiconductor layer 11 is formed to a thickness of 0.03 to 0.03 by a plasma CVD method.
0.3 μm, gate insulating film 12 by plasma CVD
Silicon nitride or silicon oxide to a thickness of 0.1 to
After continuously depositing 0.3 μm, pattern processing is performed into an island shape by photolithography technology.

Next, silicon nitride or the like which will become the gate insulating film 13 is deposited to a thickness of 0.1 to 0.4 by plasma CVD.
After forming a film with a thickness of μm,
A through hole for making an electrical contact with the source bus wiring 6 is patterned at a predetermined position of the gate insulating film 13.

Further, a metal film of chromium, tantalum, molybdenum, aluminum or the like is formed to a thickness of 0.1 by a sputtering method.
After forming a film having a thickness of 1 to 0.5 μm, the gate electrode 14 and the gate bus line 7 are formed by etching into a predetermined shape by photolithography.

An active matrix substrate is obtained by the above manufacturing steps.

On the other hand, on the opposite substrate, first, a pattern is formed on a glass substrate 17 by applying, exposing and developing photosensitive acrylic or photosensitive vinyl alcohol in which a pigment is dispersed. Three types of photosensitive resins in which red, green, and blue pigments are respectively dispersed are prepared, and the pattern forming process is repeated three times to form a colored layer 2 in which three colors are alternately arranged in a stripe or a matrix. I do.

An ITO film is formed thereon to a thickness of 0.03 to 0.1 μm by a sputtering method, and then is etched into a predetermined shape to form the transparent common electrode 16.

An alignment film is applied to the electrode forming side surfaces of the two substrates obtained as described above, and the surfaces of the alignment films are rubbed.

Thereafter, the substrates are opposed to each other with plastic beads having a diameter of 3 to 8 μm therebetween, with the surface coated with the alignment film facing inward, and bonded together using a sealing resin.
At this time, the substrates are bonded so that the rubbing directions of the alignment films of the substrates are perpendicular to each other.

Thereafter, a liquid crystal material is injected from an injection hole provided by previously opening a part of the sealing resin, and the injection hole is sealed.

Finally, a polarizing plate is attached to the outside of the two substrates so that the transmission axis is substantially parallel to the rubbing direction of each substrate. A liquid crystal display device is obtained by the above manufacturing steps.

In the first embodiment, a polyimide resin or a silicon resin is used as the organic interlayer insulating layer 4. However, a transparent organic insulating material having a heat resistance of 300 ° C. or more is also used. Any thermosetting resin capable of forming a film can be used as a material. For example, a high molecular compound such as polyimide or acrylic resin can be considered.

[Embodiment 2] A second embodiment of the present invention will be described. The second embodiment of the present invention is structurally similar to the first embodiment, but the manufacturing method is different as follows.

First, as in the first embodiment, a light-shielding film 3 is formed on a glass substrate 1.

Next, for example, the above document (3) (Asia
Display 95 Proceedings (p. 721)) reported benzocyclobutene (Divinyl Siloxane bis).
An organic interlayer insulating layer 4 having a thickness of 1 to 5 μm is formed by spin coating and thermal baking using a transparent and low-dielectric constant thermosetting resin having a siloxane skeleton such as -Benzocyclobutene).

Thereafter, plasma anodic oxidation is performed in an oxygen atmosphere, so that the surface of the organic interlayer insulating layer 4 has a surface thickness of 0.01 to 0.
The inorganic interlayer insulating layer 5 is formed by transforming a 1 μm portion into silicon oxide.

When this plasma oxidation method is used, 10
Since plasma processing at a low temperature of 0 ° C. or less is possible, plasma CVD
It is not necessary to heat the substrate to 300 ° C. or more as in the case of the method, and the manufacturing process can be shortened accordingly. Also,
The sputtering method requires a silicon oxide target, and the plasma CVD method requires a reactive gas. However, the only material required in the plasma oxidation method is an oxygen gas, so that the manufacturing cost can be reduced accordingly. .

The subsequent manufacturing steps are performed in the same manner as in the first embodiment, whereby a liquid crystal display device can be obtained.

[Embodiment 3] FIG. 4 is a sectional view showing a part of a liquid crystal display device according to a third embodiment of the present invention. In this embodiment, the planar structure is the same as that of the first embodiment, except that the colored layer 2 is formed on the active matrix substrate side.

Referring to FIG. 4, on a glass substrate 1,
First, a colored layer 2 was formed, then a light shielding layer 3 also serving as a black matrix was formed, and an organic interlayer insulating layer 4 and an inorganic interlayer insulating layer 5 were sequentially formed so as to cover the colored layer 2 and the light shielding layer 3. The remaining structure is the same as that of the active matrix substrate of the first embodiment.

In this case, a polyimide resin having excellent heat resistance is desirable as the base material of the colored layer 2.

The opposing substrate has a simple structure in which a transparent common electrode 16 is formed on a transparent insulating substrate 17.

The other parts are exactly the same as those of the first embodiment.

This liquid crystal display device can be manufactured as follows.

First, a photosensitive acrylic or a photosensitive polyimide in which a pigment is dispersed is applied on the glass substrate 1 -exposure-
Patterning is performed by a development process to form three types of colored layers of red, green, and blue in a matrix.

Subsequently, a film of chromium, chromium oxide, or the like is formed to a thickness of 0.1 to 0.4 μm by a sputtering method, and is patterned into a predetermined black matrix shape by using a photolithography technique. The layer 3 is formed.

On top of this, a transparent and low-dielectric constant thermosetting resin made of polyimide resin, silicon resin or the like is used for 1 to 5 times.
The organic interlayer insulating layer 4 is formed by spin-coating to a thickness of μm and baking by heat.

[0096] A silicon oxide film is formed thereon to a thickness of 0.01 to 0.1 µm by sputtering or plasma CVD to form an interlayer insulating layer 5.

The subsequent manufacturing process is performed in the same manner as in the first embodiment, whereby an active matrix substrate can be obtained.

On the other hand, the opposite substrate is provided on the glass substrate 17 by IT.
An O film is formed to a thickness of 0.03 to 0.1 μm by a sputtering method, and is etched into a predetermined shape to form a transparent common electrode 1.
6 is obtained.

The subsequent manufacturing steps are performed in the same manner as in the first embodiment, whereby a liquid crystal display device can be obtained.

The method of the second embodiment can be applied to the method of manufacturing the organic interlayer insulating layer 4 and the inorganic interlayer insulating layer 5.

[0101]

As described above, according to the present invention,
Since the black matrix is formed on the active matrix substrate side, the required margin in consideration of the deviation is reduced from 10 μm to 2 μm as compared with the conventional case where they are formed on the counter substrate side. Can be improved.

According to the present invention, the interlayer insulating layer formed between the light-shielding layer and the source bus line and the pixel electrode is
By forming the organic polymer compound by spin coating and thermal baking, it is possible to form a low-dielectric-constant insulating layer having a uniform thickness and film quality to a thickness of several μm. This allows
Since the capacitance of the capacitor between the wiring and the light-shielding layer or between the pixel electrode and the light-shielding layer can be reduced, the capacitance coupling between the source bus wiring and the pixel electrode and the occurrence of signal delay on the wiring can be controlled to a negligible level. It becomes possible.

According to the present invention, by forming a thin silicon oxide film on the organic insulating film, the lower portion of the semiconductor layer has a structure protected by the inorganic insulating layer. Diffusion of molecules into the semiconductor layer is prevented, and a TFT having excellent characteristics can be stably manufactured.

Further, in the present invention, when a polymer compound having a siloxane skeleton is used as the organic insulating film, the surface can be transformed into a silicon oxide film by performing a plasma treatment in an oxygen atmosphere. When the interlayer insulating layer is formed using this method, the time required for manufacturing is reduced and the material cost is reduced, as compared with the case where a silicon oxide film is formed on the organic insulating film by a sputtering method or a plasma CVD method. Can be cut, so that the throughput can be increased and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a part of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a cross section taken along line AA of FIG. 1;

FIG. 3 is a diagram schematically showing a cross section taken along line BB of FIG. 1;

FIG. 4 is a plan view showing a part of a liquid crystal display according to another embodiment of the present invention.

FIG. 5 is a plan view showing a part of a conventional liquid crystal display device.

FIG. 6 is a diagram schematically showing a cross section taken along line AA of FIG. 4;

FIG. 7 is a diagram schematically showing a cross section taken along line BB of FIG. 4;

FIG. 8 is a sectional view showing a part of a conventional liquid crystal display device.

FIG. 9 is a cross-sectional view showing a part of a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 17 Transparent insulating substrate 2 Colored layer 3, 18 Light shielding layer 4 Interlayer insulating layer (organic insulating film) 5 Interlayer insulating layer (inorganic insulating film) 6 Source bus wiring 7 Gate bus wiring 8 Source electrode 9 Drain electrode 10 Transparent pixel electrode Reference Signs List 11 semiconductor layer 12, 13 gate insulating layer 14 gate electrode 15 liquid crystal layer 16 transparent common electrode 19 auxiliary capacitance electrode 20 TFT (thin film transistor) 21 ohmic contact layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B23K 103: 20

Claims (10)

[Claims] An active matrix substrate on which a plurality of pixel electrodes and a plurality of forward staggered TFT (thin film transistor) elements for driving the plurality of pixel electrodes are arranged in a matrix; a counter substrate having a transparent electrode; A liquid crystal display device, comprising: a liquid crystal layer sealed to both substrates; and a liquid crystal display device comprising: a light shielding layer formed on a transparent insulating substrate and also serving as a black matrix; A formed organic interlayer insulating layer, an inorganic interlayer insulating layer formed thinly thereon, a plurality of transparent pixel electrodes arranged and formed on the inorganic interlayer insulating layer, and a driving order for each of the plurality of transparent pixel electrodes. A liquid crystal display device, comprising: a staggered thin film transistor element. 2. The liquid crystal display device according to claim 1, wherein in the active matrix substrate, a colored layer is formed between the transparent insulating substrate and the organic interlayer insulating layer. 3. The organic interlayer insulating layer is selected from polymer compounds such as polyamide, polyimide, acrylic resin, and silicone resin, and has a predetermined thickness, preferably approximately 1.0
The liquid crystal display device according to claim 1, wherein the liquid crystal display device is configured by an organic insulating film formed to have a thickness of about 5.0 μm. 4. The method according to claim 1, wherein the inorganic interlayer insulating layer is formed of a silicon oxide film or a silicon nitride film having a thickness of at least 0.01 μm by a sputtering method or a plasma CVD (chemical vapor deposition) method. 3. The liquid crystal display device according to claim 1, wherein: 5. The organic interlayer insulating layer is formed of a siloxane skeleton organic insulating film having a predetermined thickness, preferably, about 1.0 to 5.0 μm. 3. A silicon oxide film having a thickness of about 0.01 [mu] m or more formed by denaturing the surface of the organic insulating film by a plasma treatment in an oxygen atmosphere. 3. The liquid crystal display device according to 1. 6. The light-shielding layer according to claim 1, wherein the light-shielding layer is provided so as to overlap the entire area between the plurality of transparent pixel electrodes and a peripheral area of the transparent pixel electrode. Liquid crystal display device. 7. The light-shielding layer is provided in the entire area between the plurality of transparent pixel electrodes and in the periphery of the transparent pixel electrodes substantially in a range of 1.0 to 2..
The liquid crystal display device according to claim 1, wherein the liquid crystal display device is provided so as to overlap a region of 0 μm. 8. An active matrix substrate in which a plurality of pixel electrodes and a plurality of forward staggered TFT elements for driving the plurality of pixel electrodes are arranged in a matrix, an opposing substrate having a transparent electrode, and both substrates. A method of manufacturing a liquid crystal display device including a sealed liquid crystal layer, wherein the step of forming the active matrix substrate includes the steps of: (a) forming a light shielding layer also serving as a black matrix on a transparent insulating substrate; (B) a second step of forming an organic interlayer insulating layer thereon so as to cover the entire surface thereof; (c) a third step of forming a thin inorganic interlayer insulating layer thereon; A fourth step in which a plurality of transparent pixel electrodes and a forward stagger type TFT element for driving each of the plurality of transparent pixel electrodes are arranged in a matrix. Manufacturing method of a display device. 9. The insulating film according to claim 2, wherein the second step and the third step form a high molecular compound having a siloxane skeleton as an insulating film by spin coating and thermal baking, and then perform a plasma treatment in an oxygen atmosphere. 9. The method for manufacturing a liquid crystal display device according to claim 8, comprising a step of transforming only the surface into a silicon oxide film. 10. A light-shielding layer also serving as a black matrix and an organic interlayer insulating layer are formed in this order on one transparent insulating substrate, and an inorganic interlayer insulating layer is formed thereon to cover the entire surface. A liquid crystal display device, comprising: a staggered thin film transistor, a source bus wiring, a gate bus wiring, and a transparent pixel electrode formed thereon in a matrix, and liquid crystal sandwiched between the substrate and a substrate facing the substrate. .