JP3304298B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device used for OA equipment such as a word processor or a personal computer, portable information equipment such as an electronic organizer, or a camera-integrated VTR equipped with a liquid crystal monitor. .

[0002]

2. Description of the Related Art In recent years, OA (Office Automation) devices such as personal computers have become more portable, and reducing the cost of display devices has become an important issue. This display device has a configuration in which a pair of substrates each having electrodes formed thereon is provided with a display medium having electro-optical characteristics interposed therebetween, and display is performed by applying a voltage between the electrodes.

As such a display medium, liquid crystal, electroluminescence, plasma, electrochromic, and the like are used. In particular, a liquid crystal display (Liquid Crystal Display) using liquid crystal is used.
y; LCD) is the most practical because it can display with low power consumption.

Considering a display mode and a driving method of this liquid crystal display device, a super-twisted nematic (Super
Simple matrix schemes such as r Twisted Nematic (STN) belong to the class that can realize the lowest cost.

[0005] However, in the future, as information becomes more multimedia, it is required to increase the resolution, contrast, multi-gradation (multi-color, full-color) and the viewing angle of the display. It is considered that the simple matrix method is difficult to cope with.

Therefore, an active matrix system has been proposed in which switching elements (active elements) are provided in individual pixels to increase the number of drivable scanning lines (also referred to as scanning electrodes). Higher resolution, higher contrast, multi-gradation, and higher viewing angle are being achieved.

An active matrix type liquid crystal display device has a configuration in which pixel electrodes provided in a matrix and scanning lines passing in the vicinity of the pixel electrodes are electrically connected via active elements. I have.

As the active element, a two-terminal nonlinear element (Metal-Insulator-Meta) is used.
1; MIM) or a three-terminal non-linear element, and a typical example of an active element currently employed is a three-terminal thin film transistor (Thin Film Tran).
(sistor; TFT).

In recent years, there has been an increasing demand for lower power consumption, and a reflection type liquid crystal display device has been actively developed in place of a transmission type liquid crystal display device which usually requires a backlight. Such a reflection type liquid crystal display device performs display by reflecting external incident light by a reflection means.

Further, a liquid crystal display device having both functions of the reflection type and the transmission type has been proposed by a patent application (Japanese Patent Application No. 9-201176). The liquid crystal display device proposed by this patent application uses a light transmitted through a transmission portion from a backlight when the surroundings are completely dark by forming a reflection portion and a transmission portion in one display pixel. When the external light is dark, the display is performed using both the light transmitted from the backlight through the transmitting portion and the light reflected by the reflecting portion, and further, the external light is bright. In such a case, the liquid crystal display device is a transflective liquid crystal display device configured to perform display using light reflected by the reflection unit.

In order to obtain a bright display as a liquid crystal display device that performs display using such reflected light, the intensity of light scattered in a direction perpendicular to the display screen with respect to incident light from all angles is required. Need to increase. For that purpose, it is necessary to produce a reflection plate having optimal reflection characteristics, and on the surface of a substrate made of glass or the like, forming irregularities controlled to have optimal reflection characteristics, It is necessary to form a reflection plate on which a thin film such as Ag is formed.

[0012] As a practiced method, for example, a photosensitive resin is applied on a substrate, and the photosensitive resin is exposed and developed through a light shielding means in which circular light shielding areas are arranged, and then heat treatment is performed. , Forming a plurality of convex portions. Then, an insulating protective film is formed on the convex portion along the shape of the convex portion, and a reflector made of a metal thin film is formed on the insulating protective film.

Further, when the reflection plate is formed on the outside of the substrate (the side opposite to the liquid crystal layer) and the double reflection due to the influence of the thickness of the glass is caused, the reflection plate is formed inside the substrate and the pixel is formed. The problem is solved by using a structure also serving as an electrode, that is, a reflective electrode.

[0014]

In a conventional liquid crystal display device which performs display using reflected light as described above,
As a matter of course, it is preferable that the reflective electrode is made of a material having a high reflectivity. In that sense, Ag is optimal. However, Ag is a material having a high diffusivity into the Si layer.
The problem of diffusion and reaction to the substrate is great.

On the other hand, Al has a low possibility of diffusion and reaction into the underlayer, is widely used for metallization in integrated circuits, and has good characteristics such as etching conditions. Is often done.

By the way, in the above-mentioned conventional technology,
ITO used for transparent electrode parts, etc., for the purpose of preventing high resistance due to oxidation of the connection part in a later process, etc., for wiring for transmitting video signals and connection electrodes for liquid crystal driving drivers Is used.

A conventional method for forming a connection electrode in such a wiring terminal will be briefly described with reference to the drawings. 9 (a) to 9 (f) show process cross-sectional views of a connection electrode in a terminal portion of a scanning line of a conventional liquid crystal display device, and FIGS. 10 (a) to 10 (f) show conventional liquid crystal display devices. 3 is a process sectional view of a connection electrode in a terminal portion of the signal wiring of FIG.

In the terminal portions of the scanning wiring and the signal wiring, first, as shown in FIGS. 9A and 10A, a Ta wiring serving as a scanning wiring 52 is formed on a substrate, and then a gate insulating film is formed. 55 are formed.

Next, as shown in FIGS. 9B and 10B, the ITO film 58 and the signal wiring film 5 serving as signal wiring are formed.
9 are formed, and thereafter, FIGS.
As shown in (c), the metal layer formed in the previous step is patterned, and the lower ITO film 58 is formed on the wiring terminal.
The connection electrode 65 and the connection electrode 66 are formed except for the above.

Next, as shown in FIGS. 9 (d) and 10 (d), after an interlayer insulating film 61 has been formed, A
163 is formed. Here, in the mass production process, Al
Since it is impossible to form a film partially, the film is formed over the entire surface of the substrate. For this reason, as shown in FIGS. 9E and 10E, a reflective electrode film made of Al63 is formed on the connection electrode 65 and the connection electrode 66 made of the ITO film 58. Thus, exposure and development of the resist film 64 are performed by the photolithography method.

In general, a thin film has an order of magnitude more lattice defects than a bulk material, and therefore has an imperfect crystal structure. Accordingly, many pinholes and active regions are generated in the reflective electrode film. When such a film is developed, the use of an alkaline developing solution enables
(F), as shown in FIG. 10 (f), the Al 63 is damaged, which promotes pinhole growth and corrosion of the active region.

As described above, in the conventional method for forming the connection electrode, the developing solution comes into contact with the connection electrode 65 and the connection electrode 66 made of ITO and the Al 63 at the same time, so that a battery system is formed. As a result, the reaction by such a battery system corrodes and dissolves the connection electrode 65 and the connection electrode 66 made of ITO and Al 63, and the electrolytic corrosion reaction greatly reduces the production yield of the active matrix substrate. Had the problem of getting lost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and provides a method of manufacturing a liquid crystal display device that performs display using reflected light, which can easily improve the manufacturing yield. It is intended to provide.

[0024]

To achieve the above object, according to the Invention The method for producing a liquid crystal display device of the present invention, one side of the pair of substrates disposed to face each other across the liquid crystal layer A plurality of scanning wirings, a plurality of signal wirings arranged to intersect with the scanning wirings, a switching element arranged near an intersection of the scanning wirings and the signal wirings, In a method of manufacturing a liquid crystal display device having a pixel electrode connected and at least part or all of which is made of Al having a reflective function, and a connection electrode whose surface for inputting a signal from the outside is ITO, Forming the plurality of scanning lines and switching elements on a substrate; and forming at least different ITO in a lower layer on the substrate including the scanning lines and switching elements.
Laminating two or more metal layers that, by patterning the metal layer to form a connecting electrode for inputting a signal from the external and the signal lines, then the substrate Forming an interlayer insulating film by patterning, forming an Al film as a material having a reflective function on a substrate including the interlayer insulating film, and patterning the Al film to form a part of a pixel electrode. Alternatively, a step of forming the entirety, and forming two or more kinds of metal layers constituting the connection electrode portion on the ITO such that the ITO is a surface.
Removing the metal layer, and forming a connection electrode for inputting a signal from the outside, it is characterized by having a by the above-described object is achieved.

At this time, the step of patterning the material having the reflection function and the removal of the remaining metal layer while leaving at least one of the two or more metal layers constituting the connection electrode portion are performed. The step is preferably performed by simultaneously etching with the same etchant.

At least two or more different metal layers constituting the signal wiring and the connection electrode portion for inputting a signal from the outside are made of an ITO film, Mo, an alloy containing Mo as a main component, It is preferable to be made of Ta, one of alloys containing Ta as a main component, or a laminated film thereof.

According to the method of manufacturing a liquid crystal display device of the present invention, the connection electrode portion is formed of at least two or more different metal layers, and the metal other than the metal layer which becomes the connection electrode after forming the reflective electrode material By removing the layer, the metal layer serving as the connection electrode and the reflective electrode material do not come into contact with each other during the manufacturing process of the liquid crystal display device. Therefore, the connection electrode and the reflective electrode material cause electrolytic corrosion. Therefore, it is possible to prevent the connection electrode from being damaged, and it is possible to improve the production yield.

According to the method of manufacturing a liquid crystal display device of the present invention, the step of patterning the reflective electrode material and the step of leaving at least one of the two or more metal layers constituting the connection electrode portion are performed. The process of removing the metal layer is simultaneously etched with the same etchant, so that the production yield can be easily improved without any increase in the production process as compared with the conventional liquid crystal display device production method. It is possible to make it.

Further, according to the manufacturing method of the liquid crystal display device of the present invention, at least two or more different metal layers constituting the signal wiring and the connection electrode portion are formed by the ITO film, the Mo film, and the Mo film.
Is composed of any one of Ta-based alloy, Ta, Ta-based alloy, or a laminated film thereof, so that the signal wiring can be formed of ITO and metal layer without any increase in the manufacturing process. Therefore, the wiring resistance can be reduced. In addition, since the connection electrode can be formed of an ITO film, it is possible to prevent the resistance from increasing due to surface oxidation in a later step.

In the method of manufacturing a liquid crystal display device according to the present invention, by using a photosensitive resin as the interlayer insulating film, it becomes possible to pattern the interlayer insulating film only by a photolithography process, and to easily obtain a sufficient film thickness. Can be obtained.

Further, in the method of manufacturing a liquid crystal display device according to the present invention, by forming a plurality of irregularities on the surface of the interlayer insulating film corresponding to the portion having the reflection function of the pixel electrode, the light diffusing property can be improved. It is possible to easily produce a reflective electrode having the above, and it is possible to greatly improve the display quality of the liquid crystal display device.

[0032]

First, a positional relationship between a display region and a connection electrode region (wiring terminal portion) according to an embodiment of the present invention will be briefly described with reference to FIGS. 8A to 8C.

As shown in FIG. 8A, the liquid crystal display device according to the present embodiment has a display area in which a liquid crystal layer is sandwiched between both substrates at a center portion, and the display area of this display area is formed. An interlayer insulating film is formed to the outside. Further, on the outside of the interlayer insulating film, FIG.
As shown in (c), a scanning wiring terminal portion for inputting a signal to the scanning wiring and a signal wiring terminal portion for inputting a signal to the signal wiring are formed.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIGS. FIG. 1 is a plan view of a pixel portion of the liquid crystal display device according to the present embodiment, FIG. 2 is a cross-sectional view taken along a line AB in FIG.
Shows a CD cross-sectional view in FIG.

As shown in FIGS. 1 to 3, a gate signal line 2 made of a conductive thin film of Al, Mo, Ta or the like and a gate electrode formed extending from the gate signal line 2 are formed on an insulating substrate 1. 3 and a capacitor wiring 4 are formed. As the insulating substrate 1 at this time, Ta ₂ O ₅ , Si
A film on which an insulating film such as O ₂ is formed is used. Further, the above-described capacitance wiring 4 may also serve as the gate signal line 2.

Subsequently, a gate insulating film 5 is formed on the gate electrode 3. In this embodiment, P-CVD
A gate insulating film 5 was formed by stacking SiN _x films by the method.
In order to enhance the insulating property, the gate electrode 3 may be anodized to form a first insulating film, and the above-described SiN _x film may be used as a second insulating film. Then, the semiconductor layer (amorphous S
i) 6 is continuously formed on the gate insulating film 5 by P-CVD.
It is laminated by the method.

Next, amorphous Si or microcrystalline Si doped with n ⁺ -type impurities to be the contact layers 7 and 7 ′ are laminated by the P-CVD method, and the contact layers 7 and 7 ′ and the semiconductor layer 6 are formed. Are patterned in an island shape. In the present embodiment, a dry etching method using a mixed gas of HCl + SF ₆ is employed for the etching at this time.
A mixed gas of F ₄ + O ₂ or BCl ₃ gas may be used. Further, patterning by wet etching using a Si etching liquid (HF + HNO ₃ or the like) is also possible.

Next, an ITO film is laminated by a sputtering method, and subsequently, a metal layer such as Ta or Mo is laminated. Then, after performing patterning by a photolithography process, the metal layer is etched,
Next, after patterning the ITO film by a photolithography step, the ITO film was etched using an ITO etching solution (HCl + HNO ₃ , HCl + FeCl _3, etc.) to form the signal wiring 9 and the signal wiring 9 ′. Note that the pattern of the ITO film at this time can be etched without using a photolithography process using the metal layer as a mask.

Next, an amorphous Si film doped with an n ⁺ -type impurity or a microcrystalline Si film on the semiconductor layer 6 is formed.
The film is removed by etching to form source and drain contact layers 7, 7 ', and the TFT 10 is completed.

After completion of the TFT 10, for example, a photosensitive acrylic organic resin film is applied to form an interlayer insulating film 11, and a contact hole 12 is formed in the interlayer insulating film 11. Finally, Al serving as the reflective electrode 13 is formed by a sputtering method, and is patterned into a predetermined shape, whereby a pixel portion of the liquid crystal display device according to the present embodiment is formed.

At this time, the reflective electrode 13 may be formed only in a part of the pixel portion, and light may be transmitted through the remaining pixel portion.

Further, a concave-convex shape for forming a reflective electrode having a light diffusing property in the interlayer insulating film 11 may be formed. Although not shown in FIG. 2, an example of a process of forming the uneven shape will be briefly described with reference to FIGS.

First, after a photosensitive resin is applied on a glass substrate (a) (b), exposure and development are carried out (c), and a rounded convex portion is formed by firing (d). Then, after a flattening film is applied so as to cover the protruding portion (e), a contact hole is formed by exposure and development, and (f) a reflective electrode is formed (g). It is possible to form a reflective electrode.

Embodiment 1 Hereinafter, Embodiment 1 will be described with reference to FIG. 5 and FIG. FIG. 5 (a)
FIGS. 6A to 6F are process cross-sectional views of connection electrodes at the terminal portions of the scanning wiring of the liquid crystal display device according to the first embodiment, and FIGS. FIG. 4 shows a process cross-sectional view of a connection electrode in a terminal portion of a signal wiring of a liquid crystal display device. Note that FIG.
(A) to (f) are XX sectional views in FIG. 8 (b), and FIGS. 6 (a) to (f) are Y-sections in FIG. 8 (c).
It is a Y sectional view.

In the terminals of the scanning lines and signal lines of the liquid crystal display device according to the first embodiment, first, FIG.
(A), as shown in FIG. 6A, after a Ta wiring to be the scanning wiring 2 is formed on an insulating substrate, a gate insulating film 5 is formed.

Next, as shown in FIGS. 5 (b) and 6 (b), an ITO film 8 and a signal wiring film 9 serving as signal wirings are formed, and thereafter, FIGS. 5 (c) and 6 (b). As shown in c), the ITO film 8 and the signal wiring film 9 formed in the previous step are patterned, and the ITO
A connection electrode portion is formed while leaving the film 8 and the signal wiring film 9. At this time, the signal wiring film 9 is made of Ta, an alloy containing Ta as a main component, TaN, or a laminated film of these.

Next, as shown in FIGS. 5D and 6D, a photosensitive acrylic organic resin film is applied to form an interlayer insulating film 11, and then Al13 to be a reflective electrode is formed. I do. Here, in the mass production process, Al cannot be formed partially, so that Al is formed over the entire surface of the substrate. Therefore, as shown in FIGS. 5 (e) and 6 (e), a reflective electrode film made of Al13 is formed on the ITO film 8 and the signal wiring film 9 which are connection electrode portions. In this state, exposure and development of the resist film 14 are performed by photolithography.

However, the first embodiment is different from the conventional liquid crystal display device in that the signal wiring film 9 is formed on the ITO film 8 unlike the connection electrodes in the terminal portions of the scanning wiring and the signal wiring. Therefore, even if an alkaline developing solution is used, the electrolytic corrosion of the Al13 and the ITO film 8 does not occur, and the Al13 is not damaged.

Next, after a resist film 14 is formed by a photolithography method, Al13 serving as a reflection electrode is etched. In the first embodiment, this Al
As an etching method of No. 13, Al13 serving as a reflective electrode was etched by a dry etching method using BCl ₃ gas and Cl ₂ gas. The etching selectivity by the etching method at this time is as shown in FIG.

In the etching method according to the first embodiment, at the same time as the Al13 is etched, Ta or an alloy containing Ta as a main component, TaN remaining on the connection electrode portion, or a laminated film of these are used. As a result, the signal wiring film 9 can be removed.
(F), as shown in FIG. 6 (f), a structure in which the ITO film 8 remains on the surface as the connection electrode in the wiring terminal portion. In this way, the connection electrodes at the terminal portions of the scanning wiring and the signal wiring of the liquid crystal display device according to the first embodiment are formed.

As described above, according to the configuration of the connection electrodes in the terminal portions of the scanning wiring and the signal wiring of the liquid crystal display device according to the first embodiment, Al13 serving as a reflection electrode
In the above-mentioned etching, the dry etching method using the above-mentioned gas is used, so that the IT which becomes the connection electrode can be formed without increasing the number of manufacturing steps as compared with the related art.
It is possible to prevent electrolytic corrosion of O8 and Al13 serving as a reflective electrode, and it is possible to manufacture a liquid crystal display device that performs display using reflected light at high yield and at low cost. .

(Embodiment 2) In Embodiment 1 described above, a method of manufacturing a connection electrode using a dry etching method as an etching method of Al13 has been described. However, in Embodiment 2, connection is performed at lower cost. A method for manufacturing a connection electrode using a wet etching method for manufacturing an electrode will be described.

The manufacturing process in the second embodiment is performed according to the same flow as in the first embodiment, but a Mo-based metal layer is used as a metal layer for forming the signal wiring film 9.

After the resist film 14 is formed by the photolithography method, when etching the Al13 serving as the reflection electrode, in the second embodiment, phosphoric acid + nitric acid + acetic acid is used as the etching method of the Al13. The Al13 serving as a reflective electrode was etched by a wet etching method using a solution composed of + water. The etching selectivity by the etching method at this time is as shown in FIG.

In the etching method according to the second embodiment, the signal wiring film 9 made of Mo or the like remaining on the connection electrode portion can be removed at the same time as the Al13 is etched. (F), as shown in FIG. 6 (f), a structure in which the ITO film 8 remains on the surface as the connection electrode in the wiring terminal portion. In this manner, the connection electrodes at the terminal portions of the scanning wiring and the signal wiring of the liquid crystal display device according to the second embodiment are formed.

As described above, according to the configuration of the connection electrodes in the terminal portions of the scanning wiring and the signal wiring of the liquid crystal display device according to the second embodiment, Al13 serving as a reflection electrode
In the above-mentioned etching, the wet etching method using the above-mentioned solution is used, so that the connection electrode can be formed without increasing the number of manufacturing steps as compared with the conventional method.
It is possible to prevent electrolytic corrosion between the TO8 and the Al13 serving as a reflective electrode, and to provide a liquid crystal display device that performs display using reflected light at a high yield and at a lower cost as compared with the first embodiment. It is possible to manufacture with.

[0057]

As described above, according to the method of manufacturing a liquid crystal display device of the present invention, the connection electrode portion is formed of at least two or more different metal layers, and the connection electrode portion is formed after forming the reflective electrode material. By removing the metal layer other than the metal layer serving as the connection electrode, the metal layer serving as the connection electrode and the reflective electrode material do not come into contact during the manufacturing process of the liquid crystal display device. The reflective electrode material does not cause electrolytic corrosion, so that it is possible to prevent damage to the connection electrode, and it is possible to improve the production yield.

According to the method of manufacturing a liquid crystal display device of the present invention, the step of patterning the reflective electrode material and the step of leaving at least one of the two or more metal layers constituting the connection electrode portion are performed. The process of removing the metal layer is simultaneously etched with the same etchant, so that the production yield can be easily improved without any increase in the production process as compared with the conventional liquid crystal display device production method. It is possible to make it.

Further, according to the method of manufacturing a liquid crystal display device of the present invention, at least two or more different metal layers constituting the signal wiring and the connection electrode portion are formed by the ITO film, the Mo film, and the Mo film.
Is composed of any one of Ta-based alloy, Ta, Ta-based alloy, or a laminated film thereof, so that the signal wiring can be formed of ITO and metal layer without any increase in the manufacturing process. Therefore, the wiring resistance can be reduced. In addition, since the connection electrode can be formed of an ITO film, it is possible to prevent the resistance from increasing due to surface oxidation in a later step.

[Brief description of the drawings]

FIG. 1 is a plan view of a pixel portion of a liquid crystal display device according to an embodiment.

FIG. 2 is a sectional view taken along a line AB in FIG. 1;

FIG. 3 is a sectional view taken along the line CD in FIG. 1;

FIGS. 4A to 4G are process cross-sections for forming an uneven shape for forming a reflective electrode for imparting light diffusion to an interlayer insulating film of the liquid crystal display device according to the present embodiment. FIG.

FIGS. 5A to 5F are process cross-sectional views of connection electrodes at terminals of scanning lines of the liquid crystal display device according to the first embodiment.

6 (a) to 6 (f) are process cross-sectional views of connection electrodes in a terminal portion of a signal wiring of the liquid crystal display device according to the first embodiment.

FIG. 7A is a table showing the etching selectivity of the reflective electrode according to the first embodiment by etching, and FIG. 7B is a table showing the etching selectivity of the reflective electrode according to the second embodiment; It is a table | surface which showed the etching selectivity.

8A is an overall plan view of a liquid crystal display device according to the present invention, and FIGS. 8B and 8C are enlarged plan views of a connection electrode portion.

FIGS. 9A to 9F are process cross-sectional views of a connection electrode in a terminal portion of a scanning line of a conventional liquid crystal display device.

FIGS. 10A to 10F are process cross-sectional views of a connection electrode in a terminal portion of a signal wiring of a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Gate signal line (scanning wiring) 3 Gate electrode 4 Capacitance wiring 5 Gate insulating film 6 Semiconductor layer 7 Contact layer 7 'Contact layer 8 ITO film (lower signal wiring) 8' ITO film 9 Signal wiring (Signal wiring 9 ′ connection wiring 10 TFT 11 interlayer insulating film 12 contact hole 13 reflective electrode (Al) 14 resist film 52 gate signal wiring (scanning wiring) 55 gate insulating film 58 ITO film (lower signal wiring) 59 signal wiring (signal wiring) Film 61 inter-layer insulating film 63 reflective electrode (Al) 64 resist film 65 connection electrode 66 connection electrode

──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Atsuto Murai 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Naoyuki Shimada 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp shares In-company (56) References JP-A-8-254714 (JP, A) JP-A-7-86302 (JP, A) JP-A-6-110073 (JP, A) (58) Fields investigated (Int. . ^7, DB name) G02F 1/1335 520 G02F 1/1345

Claims (3)

(57) [Claims] 1. A plurality of scanning wirings and a plurality of signal wirings intersecting the scanning wirings on one of a pair of substrates arranged opposite to each other with a liquid crystal layer interposed therebetween. And a switching element arranged near the intersection of the scanning wiring and the signal wiring, and at least a part or all of Al connected to the switching element and having a reflection function.
A pixel electrode comprising a surface for inputting signals from the outside
A method of manufacturing a liquid crystal display device having a connection electrode made of ITO , comprising: forming the plurality of scanning lines and switching elements on the one side substrate; and a substrate including the scanning lines and switching elements. A step of laminating at least two or more metal layers in which at least different ITO is a lower layer, and patterning the metal layer to form the signal wiring and a connection electrode portion for inputting a signal from the outside A step of patterning and forming an interlayer insulating film on the substrate; and a material having a reflective function on the substrate including the interlayer insulating film.
A step of forming Al as, forming a part or the whole of the pixel electrode by patterning the Al film, of two or more metal layers constituting the connecting electrode, ITO is surface So, ITO
Removing the metal layer formed thereon and forming a connection electrode for inputting the signal from outside. A method for manufacturing a liquid crystal display device, comprising: 2. The step of patterning the material having the reflective function and the step of removing one or more of the two or more metal layers constituting the connection electrode portion and removing the remaining metal layer 2. The method according to claim 1, wherein the etching is performed by simultaneously etching with the same etchant. 3. At least two or more different metal layers constituting the signal wiring and the connection electrode portion for inputting a signal from the outside are made of an ITO film, Mo, an alloy containing Mo as a main component, 3. The method for manufacturing a liquid crystal display device according to claim 1, comprising Ta, any one of alloys containing Ta as a main component, or a laminated film thereof.