JPH10333179A - Liquid crystal image display device and manufacture of semiconductor device for image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a tapered part from being formed by preventing the generation of a mouse bite when aluminum or aluminum alloy is used for a scanning line. SOLUTION: This device is equipped with a glass substrate 2 which has scanning line gate electrodes 6 formed, many unit pixels which are arrayed in two-dimensional matrix having insulation gate type transistors and pixel electrodes formed on the glass substrate 2, signal lines connected to the sources of the insulation gate type transistors, and a counter glass substrate or color filter which has liquid crystal charged with the glass substrate 2; and the scanning lines 6 are formed of a metal layer consisting principally of aluminum and at least the flank parts of the scanning lines 6 are insulated by anode oxidation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal image display device using a thin film semiconductor element as a switch element and a method of manufacturing a semiconductor device for an image display device.
In particular, the present invention relates to a technique related to lowering the resistance of a scanning line and improving the yield.

[0002]

2. Description of the Related Art An active type liquid crystal image display device in which a thin film transistor using amorphous silicon as a semiconductor material is incorporated in each pixel as a switching element is rapidly expanding in substrate size in combination with efforts to improve productivity. However, at present, the adoption of glass substrates with a size of 550 x 650 mm or more is about to be commercialized to screen sizes exceeding 20 inches (50 cm).

FIG. 5 is a perspective view of such a liquid crystal image display device (panel) 1. One transparent insulating substrate, for example, a glass substrate 2, is provided at each intersection of a scanning line 6 and a signal line 3. A thin film transistor as a switch element and a pixel electrode are arranged in a two-dimensional matrix to form an image display unit. A video signal is supplied to the signal line 3 by, for example, TCP mounting using a film carrier 5 to the terminal electrode 4 formed at the distal end of the signal line 3, and the terminal electrode 7 (not shown) at the distal end of the scanning line 6 is provided. For example, a scanning signal is supplied by COG mounting for directly connecting the semiconductor chip 8, and an image is displayed on the image display unit. Here, for the sake of convenience, two types of mounting methods are shown at the same time, but in practice any one of the methods is appropriately selected and adopted. Reference numeral 9 denotes another glass substrate facing the image display unit, and a liquid crystal is filled in a space having a thickness of several μm sandwiched between the two glass substrates 2 and 9 to function as an optical element. In many cases, the inner surface of the glass substrate 9 that is in contact with the liquid crystal is provided with a colored layer made of an organic thin film corresponding to each unit pixel or signal line, so that a color image is displayed. Often called.

FIG. 6 shows an equivalent circuit of an active type liquid crystal image display device using an insulated gate transistor 10 as a switch element, 3 is a signal line, 6 is a scanning line orthogonal to the signal line 3, 11 Is a liquid crystal cell. The elements drawn by solid lines are formed on one glass substrate 2 constituting the liquid crystal image display device, and the counter electrode 12 common to all the liquid crystal cells 11 drawn by dotted lines is formed on the other glass substrate 9. Is formed. O of the insulated gate transistor 10
When the FF resistance or the resistance of the liquid crystal cell 11 is low or when the gradation of a display image is emphasized, an auxiliary storage capacitor 13 for increasing the time constant of the liquid crystal cell 11 as a load.
Are added to the liquid crystal cell 11 in parallel.

FIG. 7 is a plan view of a unit picture element of an active substrate constituting a conventional liquid crystal image display device.
FIG. 8 is a cross-sectional view taken along the line A ′, and its manufacturing process will be briefly described below. First, as shown in FIG. 8A, a glass substrate 2 as an insulating substrate having high heat resistance and high transparency, for example, on one main surface of a product name 1737 manufactured by Corning Incorporated, a vacuum such as SPT (sputtering) is applied. Film thickness using film forming equipment
As the first metal layer of about 0.2 μm, for example, Cr, Ta,
The gate electrode 6 serving also as a scanning line is selectively formed by applying Mo or the like and by a fine processing technique.

Next, as shown in FIG. 8B, a first silicon nitride layer (SiNx) serving as a gate insulating layer is almost entirely contained on the entire surface of the glass substrate 2 by using a P (plasma) CVD apparatus. First, three types of thin film layers, that is, a first amorphous silicon layer (a-Si) and a second silicon nitride layer serving as channels of an insulated gate transistor are formed, for example, with a film thickness of 0.3 μm, 0.05 μm, 0. The second amorphous silicon nitride layer 16 on the gate 6 is selectively left to 16 'by a fine processing technique, and the first amorphous silicon layer 15 is exposed. .

Subsequently, as shown in FIG. 8C, a second amorphous silicon layer 17 containing, for example, phosphorus as an impurity, for example, having a thickness of 0.05 .mu.m
Then, the first amorphous silicon layer 15 and the second amorphous silicon layer 17 including the second silicon nitride layer 16 'on the gate 6 are formed into islands 15', 17 '. ′ To expose the transparent first silicon nitride layer 14.

[0008] Then, as shown in FIG. 8 (d), a transparent conductive, eg, ITO thin film having a thickness of about 0.1 μm is deposited using a vacuum film forming apparatus such as an SPT, and a picture element is formed by a fine processing technique. The electrode 18 is selectively formed. Further, although not shown, a glass substrate 2 necessary for electrical connection to the scanning line 6 is provided.
8A, openings are selectively formed on the scanning lines 6 in the peripheral portion of the substrate. Then, as shown in FIG. For example, a Ti thin film is used as a layer and an A layer having a thickness of about 0.3 μm
1) A thin film is sequentially deposited, and the pixel electrode 18 is
A signal line (source line) 3 and a drain line 19 for connecting the gate electrode and the drain of the insulated gate transistor are selectively formed. At this time, the second amorphous silicon layer 17 'is removed by using the Al thin film and the Ti thin film and the photosensitive resin pattern used for forming the electrodes as a mask to expose the second silicon nitride layer 16'. Let it. In order to prevent the insulated gate transistor from having an offset structure, the source / drain wirings (electrodes) 3 and 19 are formed in a positional relationship that partially overlaps the gate 6 in a plane. Note that the terminal electrode 7 of the scanning line 6 or the terminal electrode 7 of the scanning line 6 and the terminal electrode 7 of the scanning line 6 (in this case, a transparent conductive terminal electrode is selected, including the signal line 3 including the opening on the scanning line 6). It is also common to form a gate wiring (not shown) for connecting the gate wiring (not shown).

[0009] In this state, operation as an active substrate is possible, but the direct current component enters the liquid crystal cell, and the liquid crystal is degraded by high-temperature operation or long-term continuous operation, thereby avoiding the problem of reliability of coloring black. Therefore, as shown in FIG. 8F, a transparent insulating layer, for example, a silicon nitride layer 20 is further formed on the entire surface of the substrate 2 by using a PCVD apparatus.
The opening 21 is formed on the pixel electrode 18 with a thickness of about μm.
And the pixel electrode 18 is largely exposed to complete the active substrate 2. Of course, the silicon nitride layer 20 which is a passivation insulating layer on the terminal electrodes 4 and 7 of the scanning lines 6 and the signal lines 3 is also provided around the glass substrate 2 so that electric signals can be supplied to the scanning lines 6 and the signal lines 3. It has been selectively removed.

[0010] In the above-described manufacturing process, the configuration of the liquid crystal image display device is described with respect to the minimum constituent factors for easy understanding. Therefore, a technique for preventing an interlayer short circuit between the scanning line 6 and the signal line 3, a heat-resistant metal is interposed between the aluminum layer and the second amorphous silicon layer (source / drain) 17 ′ containing impurities. The explanation of the reason and the like is omitted. In addition, descriptions of spacers and sealing materials constituting a liquid crystal cell, members for an alignment film, a polarizing plate, and the like necessary for operating as a liquid crystal cell, and constituent elements necessary for an optical element such as a back light source are omitted. doing.

In FIG. 7, a region 23 in which the picture element electrode 18 and the projection 22 provided on the preceding scanning line 3 overlap via the gate insulating layer 14 constitutes the storage capacitor 12. Also, as shown in the equivalent circuit of FIG. 6, it is also possible to arrange a storage capacitor line (not shown) in parallel with the scanning line 6 to form a storage capacitor.

[0012]

In a large-screen or high-definition liquid crystal image display device, it is necessary to lower the resistance of the electrode wiring such as the scanning line 6 and the signal line 3 as a matter of course. As described above, aluminum has been used as a wiring material for the signal line 3 from an early stage, but since the deposition temperature of the gate insulating layer 14 is as high as 300 ° C. or higher for the scanning line 6, hillock generation is avoided. The use of aluminum alone for the scanning line 6 has not been realized on a mass production level.

A heat resistant metal such as Cr, Ta, Mo or the like or a silicide layer thereof is laminated on aluminum (cladding structure), or an alumina (Al ₂ O ₃ ) layer is formed on the surface of aluminum by anodic oxidation. Means for suppressing the generation of hillocks at a high temperature when the gate insulating layer 14 is applied is a conventional improvement measure, but the increase in the number of manufacturing steps has been unavoidable.

Recently, it has become possible to suppress the occurrence of hillocks even in an aluminum-based alloy by improving the degree of vacuum in the background of a film-forming chamber at the time of forming an aluminum film, but it is still difficult with pure aluminum.
As a result of the inclusion of metals such as Si, Cu, Ta, and Zr as a small amount of additive material of about several percent, problems such as an increase in the resistance value and a residue of these added metals remaining on the substrate during etching are still complete. Is not necessarily resolved. At present, it is not possible to ignore restrictions such as the need for a titanium thin film as a buffer layer between itself and the underlying glass substrate 2.

On the other hand, in order to increase the dielectric strength between the scanning line 6 and the signal line 3, a technique of forming a side surface of the scanning line 6 into a tapered shape has been introduced in forming the scanning line 6. However, when the taper angle of the scanning line 6 is increased, the thickness of the aluminum is thin at the end of the side surface, so that the adhesion strength to the glass substrate 2 is reduced. Since the manufacturing process following the process of forming the scanning line 6 is usually a process of forming the gate insulating layer 14, in order to avoid a short circuit between the scanning line 6 and the signal line 3 due to the attachment of minute foreign matter, In the step of removing the used photosensitive resin pattern, the cleaning ability is enhanced. Specifically, it is necessary to add physical force such as ultrasonic waves or bubble jets in the water washing process, and in some cases, even during peeling of the photosensitive resin, it is necessary to increase the foreign matter removing ability by these physical forces. As a result, as shown in FIG. 8, the chipping 6b of the edge often occurs in the tapered side surface 6a of the scanning line 6 (gate). Such a chip 6b of the side surface 6a is called a mouse bite. However, when the occurrence is severe, the gap between the scanning line 6 and the signal line 3 is opposite to the purpose of forming the gate cross section in a tapered shape. Short circuits increased and the yield was reduced.

The present invention has been made in view of the above situation, and when using aluminum or an aluminum alloy as a scanning line, a liquid crystal image display capable of preventing the occurrence of a mouse bite and effectively forming a tapered shape. It is an object of the present invention to provide a device and a method for manufacturing a semiconductor device for an image display device.

[0017]

According to a first aspect of the present invention, there is provided a liquid crystal image display device comprising: a first transparent insulating substrate having a scanning line also serving as a gate formed on one main surface; A large number of unit pixels arranged on a substrate and arranged in a two-dimensional matrix having at least an insulated gate transistor and a pixel electrode connected to the drain of the insulated gate transistor, A liquid crystal image display device comprising: a signal line connected to a source; and a second transparent insulating substrate or a color filter filled with liquid crystal between a first transparent insulating substrate and a scanning line. It is made of a metal layer containing aluminum as a main component, and at least a side portion of the scanning line is insulated by anodic oxidation.

According to the liquid crystal image display device of the present invention, the resistance of the scanning line can be easily reduced, and the voltage of the scanning line can be reduced in order to increase the dielectric strength between the scanning line and the signal line. Even if tapering is promoted, a mouse bite does not occur, which contributes to an improvement in yield. According to a second aspect of the present invention, in the liquid crystal image display device according to the first aspect, the scanning lines are formed by laminating a metal layer mainly composed of aluminum and a heat-resistant metal layer.

According to the liquid crystal image display device of the second aspect, the same effect as that of the first aspect is obtained. According to a third aspect of the present invention, in the liquid crystal image display device according to the second aspect, the heat-resistant metal layer is made of tantalum or titanium. According to the liquid crystal image display device of the third aspect, the same effect as that of the first aspect is obtained. According to a fourth aspect of the present invention, in the liquid crystal image display device according to the first aspect, the scanning lines are formed by laminating a metal layer mainly composed of aluminum and a silicide layer.

According to the liquid crystal image display device of the fourth aspect, the same effect as that of the first aspect is obtained. According to a fifth aspect of the present invention, in the liquid crystal image display device according to the fourth aspect, the silicide layer contains at least one of tantalum, tungsten, molybdenum, chromium, and titanium. According to the liquid crystal image display device of the fifth aspect, the same effect as that of the first aspect is obtained.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a semiconductor device for an image display device, wherein a scanning line serving also as a gate of an insulated gate transistor formed of a metal layer containing aluminum as a main component is formed on a transparent insulating substrate. A step of selectively forming a mask as a mask, a step of anodizing the side surface of the scanning line by anodizing using the photosensitive resin pattern as a mask, and a step of applying at least a gate insulating layer and a semiconductor layer serving as a channel. Forming a picture element electrode; and forming a drain wiring connecting the picture element electrode with a source wiring and a drain serving as a signal line.

According to the method of manufacturing a semiconductor device for an image display device according to the sixth aspect, before removing the photosensitive resin pattern used for selectively forming the scanning line, the side surface of the aluminum layer forming the scanning line is removed. Since it is converted to alumina by anodic oxidation,
The chemical resistance and the impact resistance against physical impact in the step of peeling and removing the photosensitive resin pattern are improved, and the hardness can be improved. As a result, it is possible to prevent the occurrence of a mouse bite and to make it effective even if the side surface of the scanning line is formed in a tapered shape.

According to a seventh aspect of the present invention, in the method for manufacturing a semiconductor device for an image display device according to the sixth aspect, after the step of insulating the side surface of the scanning line by anodic oxidation using the photosensitive resin pattern as a mask, After removing the photosensitive resin pattern,
It has a step of anodizing the entire surface of the scanning line. According to the method of manufacturing a semiconductor device for an image display device according to the seventh aspect, in addition to the same effect as the sixth aspect, the probability of a short circuit between the scanning line and the signal line can be further reduced.

According to an eighth aspect of the present invention, in the method of manufacturing a semiconductor device for an image display device according to the sixth aspect, the scanning lines are formed by laminating a metal layer mainly composed of aluminum and a heat-resistant metal layer. According to the method of manufacturing a semiconductor device for an image display device according to the eighth aspect, the same effect as that of the sixth aspect is obtained.

According to a ninth aspect of the present invention, in the method of manufacturing a semiconductor device for an image display device according to the sixth aspect, the scanning lines are formed by laminating a metal layer mainly composed of aluminum and a silicide layer. According to the method of manufacturing a semiconductor device for an image display device according to the ninth aspect, the same effect as that of the sixth aspect can be obtained.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a liquid crystal image display device and a semiconductor device for an image display device according to a first embodiment of the present invention will be described with reference to FIGS. In addition,
For convenience, the same reference numerals are given to the same or corresponding parts as in the conventional example. FIG. 1 is a process sectional view at the time of forming a scanning line on the active substrate 2 according to the first embodiment. The manufacturing process of the semiconductor device for an image display device according to the first embodiment includes:
As shown in FIG. 1A, a scanning line 6 is obtained by etching a 0.3 μm-thick aluminum or aluminum alloy layer using the photosensitive resin pattern 24. The etching method may be either a dry method using a gas or a wet method using a chemical, but it is preferable that the side surface of the aluminum layer 6 be formed in a tapered shape.

Subsequently, as shown in FIG. 1B, an alumina layer 25 is formed by anodic oxidation on the tapered side surface of the exposed aluminum layer 6 using the photosensitive resin pattern 24 as a mask. In the anodic oxidation step, as shown in FIG. 2A, the active substrate 2 is immersed in an insulating container 32 such as a vinyl chloride resin or glass containing a chemical solution 31 containing ethylene glycol as a main component. Wide solid pattern 34 to which all the scanning lines 6 are connected
A positive potential is supplied from the DC power supply 33 to perform anodic oxidation. The formation voltage was about 100 V and alumina (Al ₂
The O ₃ ) layer has a thickness of 0.15 μm, which is sufficient for improving chemical resistance and impact resistance. In order to apply a direct current to the solid pattern 34 with the clip 35 during anodic oxidation, the shape of the tip of the clip 35 is sharpened.
For example, using a saw-toothed crocodile clip 35 or the like to pierce the photosensitive resin layer having a thickness of about 2 μm on the solid pattern 34 so as to allow the crocodile clip 35 to directly reach the aluminum solid pattern 34 is the present invention. This is one of the points.

Reference numeral 36 denotes a noble metal such as gold or platinum or a cathode plate which can be simply replaced by SUS or the like. Scanning line 6
In order to anodic oxidize the side surfaces, all of the scanning lines 6 need to be connected to the solid pattern 34. As shown in FIG. 2B, the scanning lines 6 are appropriately connected in parallel and formed. It is connected to a solid pattern 34 via a line 37. Such a parallel configuration of the scanning lines 6 is separated along with the cutting of the glass substrate 2 in the liquid crystal panel forming process, or by fusing by laser irradiation or appropriate etching, and at least until the lighting image inspection after mounting is completed. Scan line 6 is 1
Each book must be completely separated, but details are omitted.
In FIG. 2B, two active substrates 2 are arranged as an example, and if it is possible to connect both ends of the scanning lines 6 to the connection lines 37 in a pattern arrangement like a device in the upper half, It can be easily understood that even if there is a disconnection in the scanning line 6, all the side surfaces of the aluminum layer 6 are anodized.

FIG. 1C shows a state in which the photosensitive resin pattern 24 is removed after forming the anodized alumina layer 25 on the side surface of the scanning line 6 made of aluminum, and is processed into a tapered shape. The thin aluminum on the side surface is anodized on the surface and changed into an alumina layer 25, so that the chemical resistance is improved, and a medium to strong alkaline organic stripping solution such as stripping solution 106 manufactured by Tokyo Ohka Co., Ltd. is used. Even if immersed for 3 minutes while heated to 80 ° C., there is no generation of a mouth bite, the impact resistance is also improved, and an ultrasonic water jet having a hole diameter of 5 mm, a discharge rate of 2 liters / minute, and a high-frequency output of 2 KW No mouse bite was generated even after spraying for 2 minutes.

With the above, the scanning line forming step of the semiconductor device for an image display device according to the first embodiment of the present invention is completed. Subsequently, through the formation of a gate insulating layer, a semiconductor layer, source / drain wiring, a pixel electrode, etc.
Although a semiconductor device for an image display device is completed, there is no problem even if an insulated gate transistor or a pixel electrode is formed by a manufacturing method different from the conventional example.

That is, the method of manufacturing a semiconductor device for an image display device according to the first embodiment is directed to a method for manufacturing an insulated gate transistor comprising a metal layer containing aluminum as a main component on a glass substrate 2 which is a transparent insulating substrate. A step of selectively forming the scanning line 6 also serving as a gate, and anodizing or selectively anodizing a side portion of the scanning line 6 using the photosensitive resin pattern 24 used for the selective formation of the scanning line as a mask. A step of oxidizing and insulating, a step of applying at least the first silicon nitride layer 14 as a gate insulating layer and a semiconductor layer to be a channel, a step of forming a picture element electrode 18, and a step of forming a source (signal line). 3) forming a drain wiring 19 connecting the wiring and the drain to the picture element electrode 18;

The liquid crystal image display device manufactured by the manufacturing method of the first embodiment has at least an insulated gate transistor on one main surface and a picture element electrode 18 connected to the drain of the insulated gate transistor. A liquid crystal is interposed between a glass substrate 2 which is a first transparent insulating substrate in which unit picture elements having the following are arranged in a two-dimensional matrix, and a counter glass substrate or a color filter 9 which is a second transparent insulating substrate. In a liquid crystal image display device filled with, a scanning line 6 also serving as a gate formed on a glass substrate 2 is made of a metal layer containing aluminum as a main component, and at least side surfaces are insulated by anodic oxidation. An insulated gate transistor including at least one or more kinds of insulating layers and a semiconductor layer as components is formed.

A second embodiment of the present invention will be described with reference to FIG. That is, FIG. 1 of the first embodiment
As shown in (c), after forming an alumina layer 25 on the side surface of the scanning line 6 made of aluminum or aluminum alloy by anodic oxidation, as shown in FIG. An alumina film 25 'is formed on the entire surface. Thus, it is not necessary to explain that the gate insulating layer can be multi-layered and the probability of a short circuit between the scanning line 6 and the signal line 3 can be reduced. Also, when compared with the anodizing method of the aluminum layer according to the prior art,
The most important point is that the alumina layer 25 is formed on the side surface in advance, and attention to the generation of a mouse bite is a clear technical advance. Even if the alumina layer 25 is formed on the side surface in advance, the thickness of the alumina layer 25 'formed on the surface of the scanning line 6 becomes the same as the anodic oxidation of the entire surface is continued. Please pay attention. Others are the same as in the first embodiment.

A third embodiment of the present invention will be described with reference to FIG. That is, the third embodiment is effective when aluminum or an aluminum alloy having high heat resistance cannot be obtained, and a heat-resistant metal or a silicide is laminated on an aluminum layer in order to prevent generation of hillocks. This is effective for forming the scanning line 6. FIG. 4 shows the third
FIG. 9 is a process cross-sectional view when forming the scanning lines 6 on the active substrate 2 according to the embodiment. As shown in FIG. 4A, the manufacturing process of the semiconductor device for an image display device according to the third embodiment includes an aluminum layer having a thickness of 0.3 μm and a thickness of 0.05 μm.
After a stack of a heat-resistant metal layer or a silicide layer having a thickness of about 0.1 μm is deposited on the glass substrate 2 by using a vacuum film forming apparatus such as SPT (sputtering), the photosensitive resin pattern 2 is formed.
4 is used as a mask, and a scanning line 6 composed of a heat-resistant metal layer or a silicide layer 27 and an aluminum layer 26 is formed.
Get. The etching method may be either a dry method using a gas or a wet method using a chemical. However, it is preferable that the side surfaces of the stacked scanning lines 6 be formed in a tapered shape. The heat-resistant metal layer is preferably made of titanium Ti or tantalum Ta whose oxide is not water-soluble, and the silicide layer is made of tungsten W or tantalum T
a, molybdenum Mo, titanium Ti, chromium Cr and the like containing at least one kind of heat-resistant metal.

Subsequently, as shown in FIG. 4B, an alumina layer 25 is formed by anodic oxidation on the side surface of the exposed aluminum layer 26 using the photosensitive resin pattern 24 as a mask. The anodic oxidation step has already been described in detail in the first embodiment and the second embodiment. Refractory metal layer or silicide layer 27 exposed portion of the their oxidized layer on the side 28, i.e. the refractory metal layer is Ti0 _2, Ta ₂ O _5, although SiO ₂ is grown as a main component in the silicide layer, these Each of the oxide layers is an insulating layer having chemical resistance and hardness equal to or higher than that of alumina (Al ₂ O ₃ ).

An alumina layer 25 and an oxide layer 2 formed by anodic oxidation on the side surface of the scanning line 6 having a laminated structure including an aluminum layer 26 and a refractory metal layer or a silicide layer 27.
4C, the photosensitive resin pattern 24 is removed, and FIG. 4C shows a state in which the thin aluminum layer 26 on the side surface of the scanning line 6 is anodized to form an alumina layer 25. As a result of the change, the point that the chemical resistance and the impact resistance are improved is exactly the same as the first embodiment and the second embodiment. Since the upper surface of the scanning line 6 is a heat-resistant metal layer or a silicide layer and the side surface is mostly an alumina layer 25, the chemical resistance of the scanning line 6 as a whole is further improved. You will understand.

Thus, the scanning line forming step of the semiconductor device for an image display device according to the third embodiment is completed. Subsequently, the gate insulating layer, the semiconductor layer, the source
After forming the drain wiring, the picture element electrode, and the like, the semiconductor device for the image display device is completed. Others are the same as in the first embodiment.

[0038]

According to the liquid crystal image display device of the first aspect, the resistance of the scanning line can be easily reduced, and the scanning is performed to increase the dielectric strength between the scanning line and the signal line. Even if the tapering of the wire is promoted, a mouse bite does not occur, which contributes to an improvement in yield.

According to the liquid crystal image display device of the second aspect, the same effect as that of the first aspect is obtained. According to the liquid crystal image display device of the third aspect, the same effect as that of the first aspect is obtained.
According to the liquid crystal image display device of the fourth aspect, the same effect as that of the first aspect is obtained. According to the liquid crystal image display device of the fifth aspect, the same effect as that of the first aspect is obtained. According to the method of manufacturing a semiconductor device for an image display device according to claim 6, before removing the photosensitive resin pattern used for selective formation of the scanning line, the side surface of the aluminum layer forming the scanning line is anodized. Since alumina is used, the chemical resistance and the impact resistance against physical impact in the step of removing and removing the photosensitive resin pattern are improved, and the hardness can be improved. As a result, it is possible to prevent the occurrence of a mouse bite and to make it effective even if the side surface of the scanning line is formed in a tapered shape.

According to the method of manufacturing a semiconductor device for an image display device according to the seventh aspect, in addition to the same effect as the sixth aspect, the probability of short-circuiting between the scanning line and the signal line can be further reduced. According to the method of manufacturing a semiconductor device for an image display device according to the eighth aspect, the same effect as that of the sixth aspect is obtained.

According to the method of manufacturing a semiconductor device for an image display device according to the ninth aspect, the same effect as that of the sixth aspect can be obtained. The main point of the present invention is that at least the side surface of the scanning line including the aluminum layer is insulated by anodic oxidation, and there is no structural difference or material difference of the insulated gate transistor other than the above restrictions. Regarding the material, configuration, or lamination of signal lines and pixel electrodes,
It will be apparent that the presence or absence and configuration of the storage capacitor are not similarly restricted by the present invention. For example, even if the configuration of the liquid crystal cell does not use a transparent conductive layer for the pixel electrode unlike the conventional one, such as an IPS device that realizes a high visual field, there is no effect on the configuration of the insulated gate transistor. Of course, it can be said that the liquid crystal image display device is included in the present invention.

[Brief description of the drawings]

FIG. 1 is a sectional view of a scanning line forming step according to a first embodiment of the present invention.

FIG. 2 is a diagram (b) showing an anodic oxidation step (a) and arrangement of scanning lines and solid patterns on an active substrate.

FIG. 3 is a cross-sectional view showing a part of an operation line forming step according to a second embodiment.

FIG. 4 is a sectional view of a scanning line forming step according to a third embodiment.

FIG. 5 is a perspective view of a liquid crystal panel.

FIG. 6 is an equivalent circuit diagram of the active liquid crystal image display device.

FIG. 7 is a plan view of a unit picture element of a conventional active substrate.

FIG. 8 is a sectional view taken along the line AA 'of FIG. 6;

9A and 9B show chipping of an edge on a side surface of a scanning line processed into a tapered shape, FIG. 9A is a partial perspective view, and FIG. 9B is a partial plan view thereof.

[Explanation of symbols]

 Reference Signs List 1 liquid crystal panel 2 active (glass) substrate 3 signal line 4 signal line terminal electrode 5 film carrier 6 scanning line (gate electrode) 7 scanning line terminal electrode 8 semiconductor chip 9 opposing glass substrate (color filter) 10 insulated gate transistor Reference Signs List 11 liquid crystal cell 12 counter electrode 13 storage capacitor 14 first silicon nitride layer (gate insulating layer) 15 first amorphous silicon layer 16 second silicon nitride layer 17 second amorphous silicon layer 18 picture element electrode DESCRIPTION OF SYMBOLS 19 Drain wiring 20 Passivation insulating layer 21 Opening on picture element electrode 22 Projection of scanning line 23 Storage capacity formation area 24 Photosensitive resin pattern for scanning line formation 25, 25 'Alumina layer 27 Heat resistant metal layer or silicide layer 28 heat-resistant metal or silicide oxide layer 31 chemical conversion liquid 32 container 33 DC power supply 34 Solid pattern 35 Clip 36 (Cathode) metal plate 37 Connection line

Claims (9)

[Claims] 1. A first transparent insulating substrate having a scanning line also serving as a gate formed on one main surface, at least an insulated gate transistor formed on the first transparent insulating substrate, and an insulated gate transistor. A plurality of unit picture elements arranged in a two-dimensional matrix having picture element electrodes connected to the drains of the transistors, a signal line connected to the source of the insulated gate transistor, and the first transparent A liquid crystal image display device comprising a second transparent insulating substrate or a color filter filled with liquid crystal between the conductive insulating substrate and the second transparent insulating substrate, wherein the scanning line is made of a metal layer mainly containing aluminum, A side surface portion of the scanning line is insulated by anodic oxidation. 2. The liquid crystal image display device according to claim 1, wherein the scanning lines are formed by laminating a metal layer mainly composed of aluminum and a heat-resistant metal layer. 3. The liquid crystal image display device according to claim 2, wherein the heat-resistant metal layer is tantalum or titanium. 4. The liquid crystal image display device according to claim 1, wherein the scanning line is formed by laminating a metal layer mainly composed of aluminum and a silicide layer. 5. The liquid crystal image display device according to claim 4, wherein the silicide layer contains at least one of tantalum, tungsten, molybdenum, chromium, and titanium. 6. A step of selectively forming a scanning line also serving as a gate of an insulated gate transistor made of a metal layer containing aluminum as a main component on a transparent insulating substrate using a photosensitive resin pattern as a mask; Using a resin pattern as a mask to insulate the side surfaces of the scanning lines by anodic oxidation, applying at least a gate insulating layer and a semiconductor layer serving as a channel, forming pixel electrodes, Forming a drain wiring connecting the picture element electrode with the source wiring and the drain to be formed. 7. After the step of anodizing the side surface of the scanning line by anodizing using the photosensitive resin pattern as a mask,
7. The method of manufacturing a semiconductor device for an image display device according to claim 6, further comprising a step of anodizing the entire surface of the scanning line after removing the photosensitive resin pattern. 8. The method for manufacturing a semiconductor device for an image display device according to claim 6, wherein the scanning line is formed by laminating a metal layer mainly composed of aluminum and a heat-resistant metal layer. 9. The method for manufacturing a semiconductor device for an image display device according to claim 6, wherein the scanning line is formed by laminating a metal layer mainly composed of aluminum and a silicide layer.