JP2000162637A - Manufacture of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacture of a liquid crystal display device, which improves efficiency in utilizing surrounding light and illuminating light (backlight) more than in a conventional device and which stabilizes the quality as well as simplifies production, in the type of a liquid crystal display device that can perform transmission display and reflection display simultaneously with one substrate. SOLUTION: A plurality of gate wiring 3 and source wiring 9a are disposed, in a manner orthogonally crossing each other on an insulating substrate 1, with a TFT 7 provided in proximity to the intersection of the wirings. Connected to a drain electrode 9c of the TFT 7 are a reflection electrode 11 and a transmission electrode 8a as pixel electrodes. The region formed by these pixel electrodes, if seen from above the substrate, is constituted of two regions, i.e., a region A having high light transmissivity and a region B having high light reflectivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a transmission type, a reflection type,
Also, the present invention relates to a liquid crystal display device that can be used as a combined type thereof and a method for manufacturing the same.

[0002]

2. Description of the Related Art A liquid crystal display device is provided with an OA device such as a word processor or a personal computer, a portable information device such as an electronic organizer, or a liquid crystal monitor by utilizing the features of being thin and having low power consumption. Widely used in camera-integrated VTRs and the like.

Also, unlike the CRT (CRT) or EL (Electroluminescence) display, the liquid crystal display mounted on the above-mentioned liquid crystal display does not emit light by itself. 2. Description of the Related Art A transmissive liquid crystal display device that is installed on a side and controls the amount of backlight transmitted by a liquid crystal display device to display an image is often used.

However, in a transmission type liquid crystal display device,
Normally, the backlight is 5% of the total power consumption of the liquid crystal display.
Since it occupies 0% or more, providing a backlight increases power consumption.

On the other hand, the transmissive liquid crystal display device, contrary to the reflective liquid crystal display device, has a problem that when the ambient light is very bright, the display looks dark and it is difficult to recognize the display.

Therefore, in addition to the above-mentioned transmissive liquid crystal display device, in a portable information device which is often used outdoors or constantly carried, a reflector is provided on one substrate instead of a backlight, and ambient light is reflected on the surface of the reflector. 2. Related Art A reflection type liquid crystal display device which performs display by reflecting light from the LCD has been used.

However, the reflection type liquid crystal display device utilizing the reflected light of the ambient light has a drawback that the visibility is extremely reduced when the ambient light is dark.

Further, in such a reflection type liquid crystal display device, display is performed using ambient light, so that when the ambient light is darker than a certain limit value, the display cannot be recognized. This was the biggest drawback of the reflection type liquid crystal display.

Further, if the reflection characteristics of the reflective electrode vary in its manufacture, the use efficiency of ambient light also varies, so that the display cannot be recognized and the ambient light intensity varies between panels. Become. Therefore, at the time of manufacturing, a liquid crystal display device having stable display characteristics could not be obtained unless variation in the reflection characteristics was controlled more than variation in the aperture ratio in the conventional transmission type liquid crystal display device.

In order to solve the problems of the reflection type liquid crystal display device and the transmission type liquid crystal display device as described above, conventionally, as shown in Japanese Patent Application Laid-Open No. Hei 7-333598, a part of the backlight light is transmitted. In addition, there is disclosed a configuration in which both a transmissive display and a reflective display are realized by one liquid crystal liquid crystal display device by using a semi-transmissive reflective film that reflects part of ambient light.

FIG. 26 shows a liquid crystal display device using the transflective film. The liquid crystal display device includes a polarizing plate 30, a retardation plate 31, a transparent substrate 32, a black mask 33, a counter electrode 3
4, alignment film 35, liquid crystal layer 36, MIM 37, pixel electrode 3
8, a light source 39, and a reflection film 40.

The pixel electrode 38, which is a transflective film, is formed by depositing metal particles very thinly over the entire surface of the pixel, or
It is formed such that minute defects and the like are scattered in the plane, and transmits light from the light source 39 through the pixel electrode 38 and reflects external light such as natural light or indoor illumination light on the pixel electrode 38. As a result, the transmissive display function and the reflective display function can be simultaneously realized.

[0013]

However, FIG.
The following problems occur in the display device shown in FIG.
First, when the above-mentioned semi-transmissive reflection film is formed by depositing metal particles very thinly, it is necessary to use a material having a large absorption coefficient, so that the internal absorption of incident light is large and absorption light not used for display or There is a problem that scattered light is generated and light use efficiency is poor (for example, 55% of light is not used for display in some models).

On the other hand, when a film in which minute hole defects or the like (hereinafter, referred to as openings) are scattered in a plane is used as the pixel electrode 38, the structure of the film is too complicated, and a precise design is required in manufacturing. Due to the accompanying conditions, it is difficult to control the film quality, and it is difficult to produce a film having uniform characteristics. In other words, the reproducibility of the electrical characteristics and optical characteristics is poor, and it has been extremely difficult to control the display quality as a liquid crystal display device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and a liquid crystal display device which simultaneously performs a transmissive display and a reflective display on a single substrate is provided with a higher ambient light than a conventional liquid crystal display device. In addition, the present invention provides a method for manufacturing a liquid crystal display device in which utilization efficiency of illumination light (backlight light) is improved, quality is stabilized, and manufacturing is simplified.

[0016]

According to the present invention, a scanning line is provided on one of a pair of substrates opposed to each other with a liquid crystal layer interposed therebetween such that the scanning line intersects the scanning line via an insulating film. A signal line formed, a thin film transistor formed in the vicinity of the intersection of the scanning line and the signal line, a drain electrode electrically connected to the signal line through the thin film transistor, and a thin film transistor or the signal line. A pixel electrode includes an interlayer insulating film formed thereon, a transmission electrode, and a reflective electrode formed on the interlayer insulating film, and the pixel electrode is electrically connected to the drain electrode. A method for manufacturing a liquid crystal display device in which a connection electrode is provided on a terminal portion outside a display area of a scanning line and each signal line, wherein the one substrate includes the scanning line, the signal line, the thin film transistor, and a terminal. Forming the connection electrode of the part Forming the interlayer insulating film so as to cover the connection electrode, and forming a reflective electrode over the interlayer insulating film and other portions, and at least a reflective electrode on the connection electrode. And patterning the reflective electrode so that the reflective electrode is present in the display area, and removing the interlayer insulating film on the connection electrode in O ₂ plasma or O ₂ plasma containing CF _4. A step of exposing the connection electrode by processing in the inside.

Further, in the present invention, the step of patterning the reflective electrode so that the reflective electrode is present in the display area and the step of exposing the connection electrode include the step of covering the thin film transistor with the reflective electrode in the display area. To be in a state,
Patterning the reflective electrode; and removing the interlayer insulating film on the connection electrode by plasma treatment to expose the connection electrode.

Further, in the present invention, the step of patterning the reflection electrode so that the reflection electrode is present in the display area and the step of exposing the connection electrode are performed in a state where the reflection electrode covers the thin film transistor. Exists in the display area, and
Patterning the reflective electrode so as to be present outside the display area; removing the interlayer insulating film on the connection electrode by plasma treatment to expose the connection electrode; Patterning the reflective electrode so as to remove the existing reflective electrode.

According to the present invention, a signal formed on one of a pair of substrates opposed to each other with a liquid crystal layer interposed therebetween so that the scanning line intersects the scanning line via an insulating film. A thin film transistor formed near the intersection of the scan line and the signal line; a drain electrode electrically connected to the signal line through the thin film transistor; and a thin film transistor formed on the thin film transistor or the signal line. A pixel electrode is composed of an interlayer insulating film, a transmission electrode, and a reflective electrode formed on the interlayer insulating film, the pixel electrode is electrically connected to the drain electrode, A method for manufacturing a liquid crystal display device, wherein a connection electrode is provided on a terminal portion outside a display region of a signal line, wherein the connection of the scanning line, the signal line, the thin film transistor, and the terminal portion is provided on the one substrate. A step of forming an electrode; Forming at least the interlayer insulating film or the metal film so as to cover the transmission electrode, and forming the reflective electrode over the interlayer insulating film or the metal film and over another portion; Removing the reflective electrode portion on the electrode and patterning the reflective electrode so that the reflective electrode is present in the display area; and removing the interlayer insulating film or the metal film on the transmission electrode. ₂ plasma, or characterized in that it comprises a step of expose the translucent over-electrode carried out by treatment with O ₂ plasma containing CF _4.

Further, the present invention provides a step of patterning the reflective electrode so that the reflective electrode exists in the display area, and removing the interlayer insulating film or the metal film on the transparent electrode to form the transparent electrode. Patterning the reflective electrode so that the reflective electrode is present in the display area in a state of covering the thin film transistor, and is present outside the outermost periphery of the reflective electrode; and Removing the interlayer insulating film or the metal film on the transmission electrode to expose the transmission electrode, and removing the reflection electrode existing outside the outermost periphery of the reflection electrode. Patterning the reflective electrode.

Further, the present invention is characterized in that the interlayer insulating film on the connection electrode and the interlayer insulating film on the transmission electrode are simultaneously removed.

The operation of the above manufacturing method will be described below. According to the first aspect of the present invention, since the reflection electrode is present in a state where the interlayer insulating film covers the connection electrode, when the reflection electrode is patterned, the reflection electrode and the connection electrode are electrically eroded via the electrolytic solution. No reaction occurs. Then, the interlayer insulating film on the connection electrode is removed by processing in O ₂ plasma or O ₂ plasma containing CF ₄ (referred to as plasma processing).
That is, since the interlayer insulating film can be removed by using it in combination with the patterning step of the reflective electrode, a new photolithography technique operation (for example, positioning of a photomask, etching, and the like) becomes unnecessary, and the manufacturing process becomes unnecessary. It can be simplified. Further, according to the plasma processing, the processing can be performed at a relatively low substrate temperature (60 to 140 ° C.), so that when the interlayer insulating film is formed of a resin film, deformation due to heat can be prevented.

According to the second aspect of the present invention, the plasma processing is performed with the reflective electrode in the display area covering the thin film transistor, so that the interlayer insulating film can be left on the thin film transistor (TFT). That is, when the interlayer insulating film on the TFT is removed, the TFT is in direct contact with the polyimide-based liquid crystal alignment film, or the distance between the two is reduced. Then, while driving for a long time, the polyimide film near the TFT undergoes interfacial polarization, deteriorating the off characteristics due to the back gate effect. Normally, the entire TFT is protected by a protective film in order to alleviate the deterioration of the off characteristic, but the interlayer insulating film further alleviates the deterioration of the off characteristic. According to the present invention, the interlayer insulating film can be left on the TFT, higher reliability can be obtained, and in some cases, a step of newly forming a protective film can be omitted. Furthermore, if the reflection electrodes are connected, an interlayer insulating film can be left between pixels. That is, since there is no sharp step in the liquid crystal layer, the alignment of the liquid crystal is stabilized, and in the normally black mode, the light-shielding film is not required on the opposite substrate. In this case, the connection portion may be removed later to separate the reflection electrode into pixel units.

According to the third aspect of the present invention, the plasma processing is performed in a state where the reflective electrode is present in the display area so as to cover the thin film transistor and is present outside the display area. Remove any existing reflective electrodes. Thereby, the following adverse effects can be prevented. When performing the plasma treatment, the reaction progresses somewhat in the direction other than the film thickness direction,
In particular, the ashing reaction proceeds isotropically. Then, the resin-based interlayer insulating film existing below the reflective electrode around the display area is also removed. As a result, a so-called overhang state occurs in which the reflective electrode around the display region protrudes outside the interlayer insulating film like an eaves. The reflective electrode in such an overhang state is liable to peel off in a later manufacturing process (particularly, a liquid crystal rubbing process). The peeled reflective electrode becomes a foreign matter in the liquid crystal cell, and has adverse effects such as a decrease in yield, a decrease in display quality, contamination of the device, and re-attachment to various models. Therefore, according to the present invention, the reflective electrode in the overhang state exists outside the display area immediately after the processing, but the reflective electrode in the overhang state is removed later, so that the reflective electrode in the display area or in the manufacturing apparatus is removed. Has no adverse effect. Therefore, the adverse effects caused by the overhanging reflective electrode around the display area as described above can be prevented.

According to the fourth aspect of the present invention, since the reflective electrode exists with the interlayer insulating film or the metal film covering the transmissive electrode, when the reflective electrode is patterned, the reflective electrode and the transmissive electrode use the electrolytic solution. No electrolytic corrosion reaction occurs. And
The interlayer insulating film on the transmission electrode is removed by plasma processing. In other words, when used in combination with the reflective electrode patterning step, the interlayer insulating film or the metal film can be removed, so that a new photolithography technology operation (for example, positioning of a photomask, etching, etc.) becomes unnecessary, The manufacturing process can be simplified. Further, according to the plasma processing, the substrate temperature is relatively low (60 to 140 ° C.)
In the case where the interlayer insulating film is made of a resin film, deformation due to heat can be prevented.

According to the fifth aspect of the present invention, plasma processing is performed in a state where the reflective electrode in the display area covers the thin film transistor, and the reflective electrode is patterned so as to exist outside the outermost peripheral portion of the reflective electrode. The reflective electrode existing outside the outermost periphery of the electrode is removed. Therefore, TF
An interlayer insulating film can be left on T. Moreover, the overhanging reflective electrode exists outside the outermost periphery of the reflective electrode immediately after the plasma processing,
Since the overhanging reflective electrode is removed later, the reflective electrode and the manufacturing apparatus are not adversely affected. Therefore, the adverse effects caused by the overhanging reflective electrode in the pixel electrode as described above can be prevented.

According to the sixth aspect of the present invention, since the interlayer insulating film on the connection electrode and the interlayer insulating film on the transmission electrode can be removed at the same time, the manufacturing method can be simplified as compared with the case where separate steps are performed. be able to.

[0028]

(Embodiment 1) A liquid crystal display device according to Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a partial plan view of an active matrix substrate in the liquid crystal display device of the present embodiment, and FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, that is, a cross-sectional view showing a configuration of a pixel portion including a TFT. 3 (a-1) to 3 (c-1),
4 (a-1) to (c-1), FIGS. 5 (a-1) to (c-
1), FIGS. 6 (a-1) to (c-1), FIGS. 7 (a-1) and (b-1) are cross-sectional views for explaining a manufacturing process of a pixel portion including a TFT. 3 (a-2)-(c-
2), FIGS. 4 (a-2) to (c-2), FIGS. 5 (a-2) to
(C-2), FIGS. 6 (a-2) to (c-2), and FIG.
FIGS. 3A and 3B are cross-sectional views for explaining a manufacturing process of a gate terminal portion located outside a display region where a pixel electrode is provided on the active matrix substrate, and FIGS. ~ (C-3), Fig. 4 (a-3) ~
(C-3), FIGS. 5 (a-3) to (c-3), and FIG.
3) to (c-3), FIGS. 7 (a-3) and 7 (b-3) illustrate a manufacturing process of a source terminal portion located outside a display region where a pixel electrode is provided on an active matrix substrate. FIG.

1 and 2, a plurality of gate wirings 3 and a plurality of source wirings 9a are arranged on a transparent insulating substrate 1 made of glass, plastic, or the like so as to be orthogonal to each other. A TFT 7 is provided in the vicinity. A reflective electrode 11 and a transmissive electrode 8a are electrically connected to the drain electrode 9c of the TFT 7 as pixel electrodes. The portion where these pixel electrodes are formed is composed of two regions, a region A having high light transmission efficiency (shaded portion in FIG. 1) and a region B having high light reflection efficiency when viewed from above the insulating substrate.

Although not shown, an alignment film having a liquid crystal alignment function is provided on the surface of the active matrix substrate shown in FIGS.

In the liquid crystal display device according to this embodiment and the following embodiments, the active matrix substrate as described above is bonded to a counter substrate provided with a transparent electrode and an alignment film,
The liquid crystal is sealed between the substrates. If necessary, a color filter, a retardation plate, a polarizing plate, and the like may be separately provided.

In this embodiment, the region A is located at the center of the pixel and has a square shape (shown in FIG. 1) when viewed from above. The cross-sectional structure (shown in FIG. 2) is formed by laminating a material having a high light transmission efficiency, and a transmission electrode 8a made of ITO connected to the drain electrode 9c of the TFT 7 is used as a part of the pixel electrode. Have. On the other hand, the region B is formed so as to surround the region A (shown in FIG. 1) when viewed from above, and is connected to the drain electrode 9c of the TFT 7 on the uppermost layer of the sectional structure (shown in FIG. 2). A reflective electrode 11 made of Al or an Al-based alloy having high light reflection efficiency is provided as a part of the pixel electrode.
As a result, the region B can efficiently reflect the incident light to the outside. Further, since the reflective electrode 11 further has a gentle uneven portion 15 on the surface thereof, the reflective electrode 11 is configured to be able to scatter incident light to an appropriate range.

The liquid crystal used was a guest-host liquid crystal ZLI2327 (manufactured by Merck) mixed with a black dye and mixed with 0.5% of an optically active substance S-811 (manufactured by Merck).

As shown in FIG. 2, the TFT 7 includes a gate insulating film 4, a semiconductor layer 5, semiconductor contact layers 6a and 6b, and a source on the gate electrode 2 branched from the gate wiring 3 (shown in FIG. 1). Electrode 9b and drain electrode 9c
Are sequentially laminated.

A transmission electrode 8a is connected to the drain electrode 9c, and the transmission electrode 8a forms a part of a pixel electrode. In a portion corresponding to the region B, an interlayer insulating film 10 and a reflective electrode 11 are provided above the transmission electrode 8a, and the reflective electrode 11 is provided through a contact hole 13 formed in the interlayer insulating film 10 to form a lower portion. The pixel electrode is electrically connected to the transmission electrode 8a and applies a voltage to the liquid crystal similarly to the transmission electrode 8a. At this time,
The transmission electrode 8a and the reflection electrode 11 are not directly connected, but are electrically connected by sandwiching a conductive metal layer 12 (made of Ti in the present embodiment) therebetween.

As shown in FIG. 7 (b-2), an external element made of ITO is formed on a terminal metal layer 150 made of a gate wiring and a source wiring provided on the insulating substrate 1, as shown in FIG. Are provided. Also,
As shown in FIG. 7 (b-2), the source terminal portion has a connection electrode 100 with an external element on a terminal metal layer 150 made of a source wiring and a gate wiring provided on the insulating substrate 1.
Is provided.

In the process of manufacturing the liquid crystal display device of the present embodiment, as described in detail below, since the transmission electrode 8a can be covered with the interlayer insulating layer 10 during the patterning of the reflection electrode 11, In both the pixel portion and each terminal portion, it is possible to effectively prevent a problem such as disconnection of the wiring due to an electrolytic corrosion reaction between ITO and Al.

In the present embodiment, Ti is used for the metal layer 12. However, the present invention is not limited to this. The same applies even if a conductive material other than Al-based material such as Cr, Mo, Ta, or W is used. The effect can be obtained.

Hereinafter, a method for manufacturing the active matrix substrate of the present embodiment will be described with reference to FIGS.

First, as shown in FIGS. 3 (a-1), 3 (a-2) and 3 (a-3), a conductive thin film is formed on an insulating substrate 1 and photolithography is performed. The gate electrode 2 and the gate wiring 3 are formed by patterning into a desired shape using a technique. In the present embodiment, glass is used as the insulating substrate 1 and Ta is used as a material of the gate electrode 2 and the gate wiring 3 (hereinafter, collectively referred to as a gate material). However, the insulating substrate 1 may be made of a material other than glass, such as plastic. Other materials having conductivity such as Al, Cr, Mo, W, Cu, and Ti may be used as the gate material.

Next, as shown in FIGS. 3 (b-1), 3 (b-2) and 3 (b-3), the gate insulating film 4, the semiconductor layer 5, and the semiconductor contact layer 6a in the pixel portion. , 6
b is formed. In this embodiment, the gate insulating film 4 is made of S
iNx, a-Si as the semiconductor layer 5, and n ⁺ -type a-Si doped with P as the semiconductor contact layers 6a and 6b are C
A continuous film was formed by the VD method. Then, the semiconductor layer 5 and the semiconductor contact layers 6a and 6b are formed by patterning into a predetermined shape by using a photolithography technique.

Next, a conductive film is formed and patterned into a predetermined shape by using a photolithography technique to form a source wiring 9a, a source electrode 9b, and a drain electrode 9c. In this embodiment, a Cr-based material is used as the conductive film.
However, as this material, Al, Mo, Ta, W, Cu, Ti
Other materials having conductivity such as the above may be used.

In each terminal section, the gate insulating film 4
Was removed, and thereafter, the electrical connection with the connection electrode 100 to be formed was improved.

Next, after a light-transmitting conductive film is formed, patterning is performed by photolithography to form a transmission electrode 8a as shown in FIG. 3C-1. At the same time, FIG. 3 (c-2) and FIG.
As shown in (c-3), in the gate terminal portion and the source terminal portion, the connection terminal 100 is formed on the gate line 3 and the source line 9a, respectively.

Thereafter, a metal film is formed, and the metal layer 12 is formed as shown in FIG.
To form The metal layer 12 is used to connect the transmission electrode 8a and the reflection electrode 11 to be formed in a later step, through both of them. In the present embodiment, Ti is used as a material. However, if the material is not Al-based, Cr, Mo, T
Other materials such as a and W may be used.

Further, as shown in FIG. 3 (c-1), the semiconductor contact layer is etched using the source electrode 9b and the drain electrode 9c as a mask, and the semiconductor contact layer is divided into a source side 6a and a drain side 6b. TF
Form T7.

Next, FIG. 4 (a-1), FIG. 4 (a-2),
Then, as shown in FIG. 4A-3, an interlayer insulating film 10 made of an organic resin film is formed on the pixel portion, the gate terminal portion, and the source terminal portion. At this time, in FIG. 4A-1, the portion of the interlayer insulating film 10 which will be the contact hole 13 later is removed by using photolithography technology.
At the same time, a gentle uneven portion 15 is formed on the region B, that is, the portion of the interlayer insulating film 10 where the reflective electrode 11 is formed.
To form

As shown in FIG. 1, the shape of the concave-convex portion 15 of this embodiment is circular when viewed from above, and its cross section changes continuously as shown in FIG. It has a gentle shape. As described above, when the reflective electrode 11 formed in the next step is provided on the interlayer insulating film 10 having the uneven portions 15 on the surface, incident light is efficiently reflected on the surface of the reflective electrode 11 and The reflected light can be scattered in an appropriate direction. The shape of the uneven portion 15 to be formed may be appropriately determined according to desired display characteristics, or the uneven portion 15 may not be formed when it is not necessary to scatter reflected light.

In this embodiment, a single-layer (about 2.5 μm) organic resin is used as the interlayer insulating film 10. However, the present invention is not limited to this, and a multilayer film made of a plurality of different materials may be used. I do not care. However, when the interlayer insulating film 10 made of an organic resin is formed relatively thick as in this embodiment,
Even if a part of the reflective electrode 11 is superimposed on the TFT 7, no parasitic capacitance is generated, and a liquid crystal display device with good display quality and high aperture ratio is obtained. In addition, with such a thick organic resin layer, it is easy to form the uneven portion 15.

Alternatively, instead of this interlayer insulating film, S
A general inorganic film such as iNx may be used as the insulating layer. However, in general, high insulating properties can be obtained even if the thickness is relatively thin, but it is difficult to form unevenness by etching. However, it is suitable when it is not necessary to form the uneven portion depending on the desired display characteristics of the liquid crystal display device.

Subsequently, as shown in FIG. 4B, Al is deposited by sputtering so as to cover the interlayer insulating film 10 in which the contact hole 13 is formed, and the reflective electrode 11 is formed. In the present embodiment, the thickness of the reflective electrode 11 is 1000 to 5000 angstroms, preferably 1
2,000-2,000 angstroms. At this time,
As shown in FIGS. 4 (b-2) and 4 (b-3), in the gate terminal portion and the source terminal portion, the connection electrode 100 is covered with the interlayer insulating film 10, and the Al electrode formed thereon is formed.
The reflection electrode 11 and the connection electrode 100 are not in contact with each other. It is assumed that the interlayer insulating film 10 between the gate terminal portion and the source terminal portion is removed in the previous step, and the connection for connecting to an external terminal (such as an IC driver) is provided at the source terminal portion and the gate terminal portion as in the present embodiment. When the electrode 100 is formed of ITO, the connection electrode 100 comes into contact with the reflective electrode 11 made of Al, and as a result, an electrolytic corrosion reaction occurs. Therefore, the connection electrode 100 and the reflection electrode 1
Although the problem can be solved by providing the interlayer insulating film 10 between
Must be removed.

In this embodiment, A is used as the reflection electrode 11.
It has been described that 1 is used.
An l-type alloy material or a conductive material having high light reflectance can be used.

Next, as shown in FIGS. 4 (c-1), 4 (c-2) and 4 (c-3), a resist 102 is applied to the entire surface of the substrate by using a spin coater. The resist 102 is pattern-exposed using a stepper and a photomask 101 so that the electrode 11 covers at least the display area and is present in an area other than the area A (transmission part) in a connected state. Preferably, as shown in FIGS. 8A and 8B, the patterning is performed so that the reflective electrode 11 exists outside the display area. The width d of the reflective electrode existing outside the display region is, for example, about 0.2 mm to about 0.4 mm.
mm (preferably about 0.3 mm). Here, FIG.
As shown in (c-2) and (c-3), the connection electrode 1
The portion 00 is exposed.

As shown in FIGS. 5 (a-1), 5 (a-2) and 5 (a-3), the resist 102 exposed by development is removed. Also at this time, the connection electrode 100
Since there is an interlayer insulating film 10 between the electrode and the reflective electrode 11, they do not directly contact each other, and thus no electrolytic corrosion occurs.

Next, as shown in FIGS. 5 (b-1), 5 (b-2) and 5 (b-3), the reflective electrode 11 on the connection electrode 100 is etched using the resist 102 as a protective mask. I do. In this embodiment, an etching solution containing phosphoric acid, acetic acid, and nitric acid is used.

Further, FIG. 5 (c-2) and FIG.
As shown in 3), the interlayer insulating film 10 on the connection electrode 100 is formed.
Is removed by plasma treatment. For example, in the present embodiment, the plasma processing is performed by using a batch type ashing apparatus, using a substrate temperature of 60 to 140 ° C. and an O ₂ flow rate of 5000 to 10
000 sccm, plasma discharge power 5000 W, plasma discharge time 600 to 1500 seconds (for example, 1200 seconds)
It is done in. Alternatively, about 3 to 10% of C in O ₂
F ₄ gas may be mixed. The plasma discharge time may be any time as long as the photosensitive resin film is removed without residue. At this time, as shown in FIG. 5C-1, the reflective electrode serves as a mask in the display area, so that the interlayer insulating film 10 below the reflective electrode 11 is not affected by the plasma processing. Therefore, the property of the interlayer insulating film 10 as an insulating protective film is not impaired, which contributes to the improvement of the reliability of the TFT 7.

At this time, as shown in FIG. 9A, when the reflective electrode 11 is provided corresponding to the display area exactly, as shown in FIG. In this case, the interlayer insulating film 10 below the reflective electrode 11 is partially ashed (under the ashing condition, the ashing is performed, for example, about 10 to 20 μm inward from the outer periphery of the display area). This is because the ashing reaction by ashing proceeds isotropically. Therefore, the outer peripheral portion of the display area has an overhang shape. The overhanging reflective electrode 11 is formed in a subsequent step (for example, a liquid crystal rubbing step).
In this case, the film is easily peeled off, and the reflective electrode 11 is partially removed to deteriorate display characteristics or adversely affect the device.
On the other hand, as shown in FIGS. 8A and 8B, when the reflective electrode 11 is provided to the outside of the display area, the interlayer insulating film in the display area is not ashed. FIG.
This is because only the portion below the reflective electrode 11 outside the display area is ashed, as shown in FIG. as a result,
As shown in FIG. 10B, the interlayer insulating film 10 in the display area
Are not removed, so that the display characteristics do not deteriorate due to the peeling of the reflective electrode 11 in the display area. At this time,
Since the overhang-shaped reflective electrodes existing outside the display area are simultaneously etched when the connected reflective electrodes are separated into each pixel unit, the yield due to the peeling of the overhang-shaped reflective electrodes outside the display area is removed. It does not cause adverse effects such as deterioration of the apparatus and contamination of the apparatus. Therefore, it is preferable that the reflective electrode 11 be provided outside the display area.

Further, as shown in FIG. 6A-1, a resist 103 is applied using a spin coater.

Next, as shown in FIG. 6B-1, the reflective electrode 11 covering the display area and being continuous is separated so as to correspond to the shape of the pixel electrode. When the reflection electrode is provided outside the display area, the reflection electrode outside the display area is also removed. This step is performed, for example, by pattern-exposing the resist 103 using a stepper and a photomask 104.

Further, as shown in FIG. 6C-1, the exposed resist 103 is removed by development.

Further, as shown in FIG. 7 (a-1), the reflective electrode film 11 in the pixel portion is etched using the resist 103 as a protective mask to separate the reflective electrode 11 so as to correspond to the pixel electrode. At the same time, the reflective electrode on the outer periphery of the display area is etched to form the pixel electrode into a predetermined shape.

Next, as shown in FIG. 7 (b-1), the resist 103 is removed in any appropriate peeling tank (not shown). Thus, the reflection electrode 11 is formed.

The active matrix substrate manufactured as described above (with liquid crystal alignment means and the like if necessary) is bonded to a counter substrate provided with a counter electrode (with liquid crystal alignment means and the like as necessary). A liquid crystal display device can be obtained by filling liquid crystal between both substrates.

The liquid crystal used was a guest-host liquid crystal ZLI2327 (manufactured by Merck) mixed with a black dye and mixed with 0.5% of an optically active substance S-811 (manufactured by Merck).

In this embodiment, by setting the area ratio between the region A and the region B to 40:60, a liquid crystal display device having good display characteristics can be obtained. Note that the area ratio is not limited to this value, and may be appropriately changed according to the transmission efficiency or the reflection efficiency of the regions A and B, and the purpose of use. Further, in the present embodiment, only one area A is provided in the center of the pixel. However, the present invention is not limited to this. The area A may be divided into a plurality of areas, and the shape is not limited to a square.

In the liquid crystal display device of the present embodiment described above and the liquid crystal display devices of the following embodiments, a region A having a high light transmission efficiency is formed as a pixel electrode 6 in the center of a pixel, and a region A having a high light reflection efficiency is formed. Since the high region B is provided, it becomes possible to use ambient light and illumination light without loss as compared with a conventional liquid crystal display device using a half mirror. Also,
Liquid crystal display devices have the problem of reduced visibility due to surface reflection in an environment where ambient light is bright in conventional transmissive liquid crystal display devices, and the decrease in panel brightness in environments where ambient light is dark in conventional reflective liquid crystal display devices. Both of the problems that display and observation are difficult can be solved at the same time, and both of these features are excellent. That is, the liquid crystal display device of the present invention enables display recognition regardless of the intensity of the ambient light, and it is not necessary to control the variation in the utilization efficiency of the ambient light due to the variation in the reflection characteristics as precisely as in the reflective liquid crystal display device. .

Further, the method for manufacturing the liquid crystal display device of the present embodiment does not require complicated manufacturing conditions unlike the conventional liquid crystal display device using a half mirror. Since general electrode materials and wiring materials and manufacturing conditions used for the liquid crystal display device may be used, the device can be manufactured relatively easily, and its reproducibility is good. Further, it is relatively easy to control display characteristics and the like, which is difficult with a liquid crystal display device using a conventional half mirror.

In the first embodiment, in order to make the thickness of the liquid crystal layer in the region A (transmission portion) and the region B (reflection portion) the same, the interlayer insulating film is left as it is. However, as described in the following embodiments, the interlayer insulating film in the region A (transmission part) may be removed in order to adjust the condition of the optical characteristics of the liquid crystal layer.

(Embodiment 2) A liquid crystal display device according to Embodiment 2 of the present invention will be described below with reference to the drawings. FIG. 11 is a partial plan view of the active matrix substrate in the liquid crystal display device of the present embodiment, and FIG.
FIG. 3C is a cross-sectional view, that is, a cross-sectional view illustrating a structure of a pixel portion. 13 (a-1) to 13 (c-1) and FIG. 14 (a-1).
-1) to (c-1), FIG. 15 (a-1) to (c-1),
FIGS. 16 (a-1) to (c-1), FIGS. 17 (a-1) and (b-1) are cross-sectional views for explaining a manufacturing process of a pixel portion including a TFT portion. a-2)-(c-
2), FIGS. 14 (a-2) to (c-2), and FIG.
2) to (c-2), FIGS. 16 (a-2) to (c-2), FIGS. 17 (a-2) and (b-2) From the display area where the pixel electrodes are provided on the active matrix substrate 13 (a-3) to 13 (c-3) and FIG. 14 are cross-sectional views for explaining a manufacturing process of the gate terminal portion on the outside.
(A-3) to (c-3), FIG. 15 (a-3) to (c-).
3), FIGS. 16 (a-3) to (c-3), and FIG.
FIGS. 3 (3) and 3 (b-3) are cross-sectional views for describing a manufacturing process of a source terminal portion located outside a display region where a pixel electrode is provided on an active matrix substrate.

In FIGS. 11 and 12, a transmission electrode 8a made of ITO is connected to a drain electrode of the TFT 7, and this transmission electrode 8a functions as a part of a pixel electrode for applying a voltage to the liquid crystal in the region A. In a portion corresponding to the region B, an interlayer insulating film 10 and a reflection electrode 11 are provided above the transmission electrode 8a.
Is a connecting metal layer 9 connected to the drain electrode 9c via a contact hole 13 formed in the interlayer insulating film 10.
d and functions as a pixel electrode similarly to the transmission electrode 8a. Also in this embodiment, similarly to the first embodiment, the structure is such that ITO as the material of the transmission electrode 8a and Al as the material of the reflection electrode 11 are not directly connected. In the region B, high light reflection efficiency of ambient light is realized by Al, and in the other region A, high transmission efficiency of backlight light by ITO is realized.

Hereinafter, a method for manufacturing the active matrix substrate of this embodiment will be described with reference to the drawings.
First, FIGS. 13 (a-1), (a-2) and (a-3)
As shown in (1), a TFT 7 is formed in the pixel portion by the same method as in the first embodiment. In the gate terminal portion and the source terminal portion, a terminal metal layer 150 including a gate wiring and a source wiring is formed. Next, the transmission electrode 8a is formed in the pixel portion by the transparent conductive film, and at the same time, the connection electrode 100 made of ITO is formed in the gate terminal portion and the source terminal portion. However, the present embodiment is different from the first embodiment in that the drain electrode 9c extends and has a connection metal layer 9d. Also, the transmission electrode 8a
Are patterned so as to cover the end of the connection metal layer 9d. A reflection electrode of the pixel electrodes is connected to the connection metal layer 9d in a later step, and the reflection electrode (not shown) and the transmission electrode 8a are electrically connected via the connection metal layer 9d. become. At this time, the source wiring 9
a, the source electrode 9b, the drain electrode 9c, and the connection metal layer 9d may be formed on the transmission electrode 8a.

Next, as shown in FIGS. 13 (b-1), (b-2) and (b-3), an organic resin is formed on the entire surface of the substrate, and an interlayer insulating film 10 is formed.

Further, as shown in FIG. 13 (c-1),
A contact hole 13 is formed in the interlayer insulating film 10 on the metal layer 9d by a photolithography technique.

Next, as shown in FIGS. 14 (a-1), (a-2) and (a-3), after the interlayer insulating film 10 is formed by the same method as in the first embodiment, the contact The interlayer insulating film 10 in the portion of the hole 13 is opened to form an uneven portion 15. Subsequently, the reflective electrode 11 is formed by depositing Al over the entire surface of the substrate by a sputtering method.

Next, as shown in FIGS. 14 (b-1), (b-2) and (b-3), a resist 102 is applied to the entire surface of the substrate using a spin coater, and a stepper and a photomask 101 are used. The resist 102 is subjected to pattern exposure. At this time, as shown in FIG. 14 (b-1), at least in the pixel portion, the reflection electrode 11 is in the region A (transmission portion).
And patterning is performed so that each pixel exists in a connected state except for the region A (transmissive portion).
Preferably, as shown in FIG. 14 (b-1), the reflection electrode 11 is present outside the outermost peripheral portion of the region desired by the reflection electrode 11, in other words, around the region A (transmission portion). Pattern the reflective electrode 11 so as to slightly cover the inside of the area A (transmission part). Further, as shown in FIGS. 8 and 10A, the patterning is performed so that the reflective electrode 11 exists outside the display area.
At this time, the width d ′ of the reflective electrode existing inside the area A (transmission part) shown in FIG. 14B-1 and the width of the reflective electrode existing outside the display area shown in FIG. d
Is, for example, about 0.2 mm to about 0.4 mm (preferably about 0.3 mm). Here, as shown in FIGS. 14B-2 and 14B-3, the connection electrode 100 is exposed.

Next, FIGS. 14 (c-1) and 14 (c-
As shown in 2) and FIG. 14C-3, the exposed resist 102 is removed by development. After this, FIG.
(A-1), FIG. 15 (a-2) and FIG. 15 (a-3)
As shown in (1), using the remaining resist 102 as a mask, the reflection electrode on the connection electrode 100 in the region A (transmission portion), the gate terminal portion, and the source terminal portion is removed by etching. Also in this embodiment, an etching solution containing phosphoric acid, acetic acid, and nitric acid was used.

Subsequently, FIGS. 15 (b-1) and 15 (b-
As shown in 2) and FIG. 15B-3, the remaining resist 102 is removed.

Thereafter, FIGS. 15 (c-1) and 15 (c-
2) and as shown in FIG. 15 (c-3), the connection electrode 1 of the region A (transmission part) and the gate terminal part and the source terminal part
The interlayer insulating film 10 covering the layer 00 is removed by plasma ashing using the reflective electrode 11 as a mask. The plasma processing was performed under the same conditions as in the first embodiment. At this time, as shown in FIG.
Serves as a mask, the interlayer insulating film 10 in the vicinity of the TFT 7 below the reflective electrode 11 is not affected by ashing. Therefore, the property of the interlayer insulating film 10 as an insulating protective film is not impaired, which contributes to the improvement of the reliability of the TFT 7.

Here, as shown in FIG. 9A, the reflective electrode 11 is provided exactly corresponding to the display area of FIG. 8, or the reflective electrode 11 is provided exactly corresponding to the area A. In this case, as shown in FIG. 9B, the reflective electrode 11 is formed on the outer peripheral portion of the display region or the outer peripheral portion of the region A.
The lower interlayer insulating film 10 is partially ashed (under the ashing condition, ashing is performed, for example, about 10 to 20 μm inward from the outer peripheral portion of the region A or the outer peripheral portion of the display region). This is because the ashing reaction by ashing proceeds isotropically. For this reason, the reflective electrodes on the outer peripheral portion of the display region and the outer peripheral portion of the region A have an overhang shape. The reflective electrode 11 having the overhang shape tends to cause film peeling in a subsequent step (for example, a liquid crystal rubbing step), and the reflective electrode 11 is partially removed to deteriorate display characteristics or adversely affect the device.

On the other hand, as shown in FIGS. 10A and 14C, when the reflection electrode 11 is provided outside the display area or inside the area A, the inside of the display area and the area The interlayer insulating film outside A is not ashed. In FIG. 10A, only the portion below the reflective electrode 11 outside the display area is ashed, and in FIG. 15C-1, the part below the reflective electrode 11 (width d ′) remaining in the area A is ashing. Only the part is ashed. as a result,
The interlayer insulating film 10 in each region remains without being removed.
Next, as shown in FIGS. 10 (b) and 17 (a-1),
The overhang-shaped reflective electrode existing outside the display area or inside the area A is simultaneously etched when the reflective electrode connected later is separated into each pixel unit. There is no adverse effect such as a decrease in yield and contamination of the device due to the peeling of the inner overhanging reflective electrode. Therefore, it is preferable that the reflective electrode 11 be provided outside the display region or inside the region A.

Further, as shown in FIGS. 16 (a-1), (a-2) and (a-3), a resist 103 is applied using a spin coater.

Further, as shown in FIGS. 16 (b-1), (b-2) and (b-3), the resist 103 is subjected to pattern exposure using a stepper and a photomask 104. At this time, as shown in FIG. 16B-1, the entire region A is not exposed in the pixel portion. This is the area A
This is for removing the reflective electrode 11 remaining inside the substrate.

Subsequently, as shown in FIGS. 16 (c-1), (c-2) and (c-3), the resist 102 exposed by development is removed.

Next, as shown in FIGS. 17 (a-1), (a-2) and (a-3), the reflective electrode 11 in the pixel portion is etched by using the resist 103 as a protective mask, and Are separated so as to correspond to each pixel electrode. At the same time, the reflective electrode (for example, Al) on the outer peripheral portion of the display area is etched to form the pixel electrode into a predetermined shape. At this time,
As shown in FIG. 17A-1, in the pixel portion, the reflective electrode 11 existing inside the region A is also removed at the same time. As a result, the reflective electrode 11 that is in an overhang state inside the region A does not peel off in a later step, and the yield does not decrease.

Next, as shown in FIGS. 17 (b-1), (b-2) and (b-3), the resist 103 is removed in any appropriate peeling tank (not shown). Thus, the reflection electrode 11 is completed.

Further, an active matrix substrate provided with liquid crystal alignment means and the like on its surface is bonded to a counter substrate provided with a counter electrode and liquid crystal alignment means and the like, and liquid crystal is sealed between the two substrates. A display device is obtained.

As described above, also in the present embodiment, Al as the reflection electrode 11 and the ITO of the transmission electrode 8a and the connection electrode 100 are not directly connected.
Occurrence of defects due to electrolytic corrosion with O can be suppressed.

(Embodiment 3) In this embodiment, another method of manufacturing the liquid crystal display device of Embodiment 2 will be described with reference to the drawings.

FIGS. 18 to 20 are sectional views for explaining a method of manufacturing the liquid crystal display device of the present embodiment.
Corresponds to the C-C section. Although the description is omitted, it is assumed that the steps up to forming Al as a reflective electrode on the entire surface of the substrate in this embodiment are performed according to the method described in the second embodiment.

The details will be described below. First, FIG.
As shown in -1), (a-2) and (a-3), a reflective electrode 11 is formed by depositing Al over the entire surface of the substrate by the same method as in the second embodiment.

Next, as shown in FIGS. 18 (b-1), (b-2) and (b-3), a resist 102 is applied.
Pattern exposure is performed using a photomask 101 by a stepper. Preferably, as shown in FIG.
Are patterned so as to exist outside the display area. The width d of the reflective electrode existing outside the display area is
For example, about 0.2 mm to about 0.4 mm (preferably about 0.2 mm to about 0.4 mm).
3 mm). Here, FIGS. 18 (b-2) and (b)
As shown in -3), the connection electrode 100 is exposed.

Next, as shown in FIGS. 18 (c-1), (c-2) and (c-3), the resist in the exposed area is removed.

Subsequently, as shown in FIGS. 19 (a-1), (a-2) and (a-3), the reflective electrode 11 is patterned so as to leave the outer peripheral portion of the display area. Al
Alternatively, when an Al-based alloy material is used, since the ITO and Al used as the transmission electrode 8a and the connection electrode 100 are entirely covered with the interlayer insulating film 10 except for the contact hole region, the Al and the ITO come into direct contact. There is no occurrence of electrolytic corrosion failure, which is particularly likely to occur in the photolithography development process.

Next, as shown in FIGS. 19 (b-1), (b-2) and (b-3), all of the interlayer insulating film 10 covering the gate terminal portion and the source terminal portion is covered with the reflective electrode 11. The mask is removed by plasma treatment. At this time, the plasma processing was performed under the same conditions as in the first embodiment. Since the reflective electrode serves as a mask in the display area, the interlayer insulating film 10 below the reflective electrode 11 is not affected by ashing. Therefore, the property of the interlayer insulating film 10 as an insulating protective film is not impaired, which contributes to the improvement of the reliability of the TFT 7.

At this time, as in the first embodiment, when the reflective electrode 11 is provided to the outside of the display region, the interlayer insulating film in the display region is not ashed. FIG.
This is because only the portion below the reflective electrode 11 outside the display area is ashed as shown in FIG. Since the interlayer insulating film 10 in the display area remains without being removed, the display characteristics do not deteriorate due to the peeling of the reflective electrode 11 in the display area.

Next, as shown in FIGS. 19 (c-1), (c-2) and (c-3), a resist 103 is applied using a spin coater. Then, FIG. 20 (a-1),
As shown in (a-2) and (a-3), the reflective electrode 11 which covers the display area and has a continuous state between the pixels corresponds to the shape of the pixel electrode, and the reflection of the area A The resist 103 is subjected to pattern exposure using a stepper and a photomask 104 so that the electrode 11 is removed.
Subsequently, FIGS. 20 (b-1), (b-2) and (b-
As shown in 3), the exposed resist is removed.

Further, as shown in FIGS. 20 (c-1), (c-2) and (c-3), the reflective electrode 11 in the pixel portion is etched to cover the display area and to reduce the distance between each pixel. Are separated so as to correspond to the pixel electrode shape. In addition, the reflective electrode 11 in a portion corresponding to the region A is also removed at the same time. When the reflective electrode is provided on the outer peripheral portion of the display area, the reflective electrode outside the display area is also removed. After that, the resist 103 is removed.

The active matrix substrate manufactured as described above (provided with liquid crystal alignment means and the like as necessary)
A liquid crystal display device can be obtained by laminating a counter substrate provided with a counter electrode (provided with a liquid crystal alignment means or the like as necessary) and sealing liquid crystal between the two substrates.

As described above, in the liquid crystal display device of the present embodiment which simultaneously performs the transmission type display and the reflection type display, Al as the reflection electrode 11, the transmission electrode 8a, and the connection electrode 100
As the ITO does not expose the ITO of the transmission electrode 8a during the patterning of the reflection electrode, the liquid crystal display device can be manufactured while suppressing the electrolytic corrosion reaction.

(Embodiment 4) A method for manufacturing a liquid crystal display device according to Embodiment 4 of the present invention will be described below with reference to the drawings. The liquid crystal display device of the present embodiment is different from the above embodiment in that a protective metal layer 9e as a source wiring material is provided between the transmission electrode and the reflection electrode above the transmission electrode 8a. . Accordingly, the step of opening the interlayer insulating film 10 on the transmissive electrode 8a as a pixel electrode is different from those of the second and third embodiments.

FIGS. 21 to 23 are sectional views for explaining a method of manufacturing the liquid crystal display device of the present embodiment.
Corresponds to the C-C section. Although the description is omitted, the process conditions before forming the reflective electrode in this embodiment are as follows.
It is assumed that the measurement is performed according to the method described in the first to third embodiments.

This will be described in detail below. FIG. 21 (a-1)
As shown in the figure, the protection metal layer 9 is provided in the region A (transmission part).
The difference from the other embodiments is that e is provided. The protective metal layer 9e is formed by the same process as the source wiring 9a, the source electrode 9b, the drain electrode 9c, and the connection metal layer 9d after forming the transmission electrode 8a. In this embodiment, a Ta-based material is used as the source material.

Next, the source electrode 9b and the drain electrode 9c
The semiconductor contact layer is etched using the mask as a mask, and divided into a source side 6a and a drain side 6b to form a TFT.

Thereafter, an interlayer insulating film 10 is formed, and the interlayer insulating film 10 corresponding to the region A (transmitting portion) and the interlayer insulating film 10 at the contact hole 13 are opened by using a photolithography technique. . FIGS. 21 (a-2) and (a-).
As shown in 3), the interlayer insulating film 10 existing in the terminal portion is left. At this time, an uneven portion 15 for scattering incident light is formed on the surface of the interlayer insulating film 10 corresponding to the region B.

Then, an Al or Al-based alloy film of the reflection electrode 11 is formed on the entire surface of the substrate.

Next, as shown in FIGS. 21 (b-1), (b-2) and (b-3), a resist 102 is applied, and a region B is ―
The terminal portions shown in 2) and (b-3) are exposed.

Further, as shown in FIGS. 21 (c-1), (c-2) and (c-3), the unexposed portions of the resist 102 are removed. Then, FIG.
1) As shown in (a-2) and (a-3), the reflective electrode 11 is patterned by etching. After the etching, the resist 102 is removed.

At this time, as in the above-described embodiment, the reflective electrode 11 is assumed to be in an overhang state in a later step of etching the interlayer insulating film 10 by the plasma treatment. It is preferable to leave it slightly inside the region A.

Thereafter, as shown in FIGS. 22 (b-1), (b-2) and (b-3), the protective metal layer 9e covering the region A (transmitting portion) is changed to the reflective electrode 11 as shown in FIG. Is removed as a mask.

Further, as shown in FIGS. 22 (c-1), (c-2) and (c-3), the reflective electrode 11 is used as a mask by ashing, and as shown in FIGS. 22 (c-2) and (c-3).
3) The interlayer insulating film 10 at the terminal portion is removed. Also, O
It is also possible to remove them at the same time by plasma processing by dry etching using a mixed gas of ₂ plasma or CF ₄ .

Finally, as shown in FIGS. 23 (a-1), (a-2) and (a-3), the reflection electrode 11 is separated for each pixel. When the reflection electrode 11 is left inside the region A, this portion is also removed at the same time.

As described above, in the method of manufacturing the liquid crystal display device according to the present embodiment, when patterning Al as the reflective electrode 11, the protective metal layer 9e is interposed on the transmissive electrode 8a and further covered with the interlayer insulating film. Al and IT
The electrolytic corrosion reaction with O can be suppressed. For the connection electrode, A
Since the interlayer insulating film intervenes on the reflective electrode 11 of 1 and the transparent electrode 8a of ITO, it is possible to suppress the occurrence of defects due to electrolytic corrosion of Al and ITO. The protective metal layer 9e and the interlayer insulating film interposed during the manufacturing process can be removed by plasma processing using the patterned reflective electrode as a mask.

Embodiment 5 A method for manufacturing a liquid crystal display device according to Embodiment 5 of the present invention will be described below with reference to the drawings. The liquid crystal display device and the method of manufacturing the same according to the present embodiment are different from the fourth embodiment in the structure in which the protective metal layer 9e is integrated with the drain electrode 9c and the connecting metal layer 9d.

FIGS. 24 to 25 are sectional views for explaining a method of manufacturing the liquid crystal display device of the present embodiment.
Corresponds to the C-C section. Although the description is omitted, the process conditions before forming the reflective electrode in this embodiment are as follows.
It is assumed that the measurement is performed according to the method described in the first to third embodiments.

This will be described in detail below. FIG. 24 (a-1)
As shown in FIG. 7, the drain electrode 9 is provided in the region A (transmission portion).
c, The protection metal layer 9e is provided in a state where the connection metal layer 9d is extended. The protective metal layer 9e is formed by the same process as the source wiring 9a, the source electrode 9b, the drain electrode 9c, and the connection metal layer 9d after forming the transmission electrode 8a. In this embodiment, a Ta-based material is used as the source material.

Next, the source electrode 9b and the drain electrode 9c
Is used as a mask to etch the semiconductor contact layer, and the TFT is formed by dividing the semiconductor contact layer into a source side 6a and a drain side 6b.

Thereafter, an interlayer insulating film 10 is formed, and the interlayer insulating film 10 corresponding to the region A (transmitting portion) and the interlayer insulating film 10 in the contact hole 13 are opened by using a photolithography technique. . FIGS. 24 (a-2) and (a-).
As shown in 3), the interlayer insulating film 10 existing in the terminal portion is left. At this time, an uneven portion 15 for scattering incident light is formed on the surface of the interlayer insulating film 10 corresponding to the region B.

Then, the reflection electrode 11 as A
An l- or Al-based alloy film is formed.

Next, a resist is applied in the same manner as in FIGS. 21 (b-1), (b-2) and (b-3), and the region B and the terminals are exposed using a photomask. I do.

Further, in the same manner as in FIGS. 21 (c-1), (c-2) and (c-3), the unexposed portions of the resist 102 are removed. Then, FIG.
1) As shown in (b-2) and (b-3), the reflective electrode 11 is patterned by etching, and the resist is removed.

At this time, as in the above-described embodiment, the reflective electrode 11 is assumed to be in an overhang state in a later step of etching the interlayer insulating film 10 by plasma treatment. It is preferable to leave it slightly inside the region A.

Thereafter, as shown in FIGS. 24 (c-1), (c-2) and (c-3), the protective metal layer 9e covering the region A (transmitting portion) is covered with the reflective electrode 11. Is removed as a mask.

Further, as shown in FIGS. 25 (a-1), (a-2) and (a-3), the reflective electrode 11 is used as a mask by O ₂ plasma ashing to form
2) and (a-3), the interlayer insulating film 10 at the terminal portion is removed. Further, it is also possible to remove them at the same time by plasma processing by dry etching using a mixed gas of O ₂ plasma or CF ₄ .

Finally, as shown in FIGS. 25 (b-1), (b-2) and (b-3), the reflection electrode 11 is separated for each pixel. When the reflection electrode 11 is left inside the region A, this portion is also removed at the same time.

As described above, in the method of manufacturing the liquid crystal display device of the present embodiment, when patterning the Al which is the reflective electrode, the protective metal layer 9e is interposed on the transmissive electrode 8a and further covered with the interlayer insulating film. Therefore, the electrolytic corrosion reaction between Al and ITO can be suppressed. As for the connection electrode, the occurrence of defects due to electrolytic corrosion between Al and ITO can be suppressed by interposing an interlayer insulating film on the Al reflection electrode 11 and the ITO transmission electrode 8a. The protective metal layer 9e and the interlayer insulating film interposed during the manufacturing process can be removed by plasma processing using the patterned reflective electrode as a mask.

[0126]

According to the present invention, the interlayer insulating film is removed by plasma treatment after the patterning of the reflective electrode in the pixel electrode or the connection electrode portion of the terminal portion, so that the electrolytic corrosion reaction can be performed without complicated steps. It is possible to manufacture a liquid crystal display device while suppressing the occurrence. Further, the reliability of the TFT can be improved by leaving the interlayer insulating film on the TFT. Further, there is no possibility that the overhanging reflective electrode is peeled off and has no adverse effect.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a liquid crystal display device according to a first embodiment.

FIG. 2 is a cross-sectional view illustrating the liquid crystal display device according to the first embodiment.

FIG. 3 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the first embodiment.

FIG. 4 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the first embodiment.

FIG. 5 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the first embodiment.

FIG. 6 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the first embodiment.

FIG. 7 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the first embodiment.

FIG. 8 is a plan view for explaining the method for manufacturing the liquid crystal display device of the first embodiment.

FIG. 9 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the first embodiment.

FIG. 10 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the first embodiment.

FIG. 11 is a plan view illustrating a liquid crystal display device according to a second embodiment.

FIG. 12 is a cross-sectional view illustrating a liquid crystal display device according to a second embodiment.

FIG. 13 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the second embodiment.

FIG. 14 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the second embodiment.

FIG. 15 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the second embodiment.

FIG. 16 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the second embodiment.

FIG. 17 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the second embodiment.

FIG. 18 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the third embodiment.

FIG. 19 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the third embodiment.

FIG. 20 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the third embodiment.

FIG. 21 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the fourth embodiment.

FIG. 22 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the fourth embodiment.

FIG. 23 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the fourth embodiment.

FIG. 24 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the fifth embodiment.

FIG. 25 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device of the fifth embodiment.

FIG. 26 is a cross-sectional view illustrating a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Gate electrode 3 Gate wiring 4 Gate insulating film 5 Semiconductor layer 6a 6b Semiconductor contact layer 7 TFT 8a Transmission electrode 8b Source electrode 8c Drain electrode 9a Source wiring 9b Source electrode 9c Drain electrode 9d Connection metal layer 9e For protection Metal layer 10 Interlayer insulating film 11 Reflective electrode 12 Metal layer 13 Contact hole 15 Uneven portion 100 Connection electrode 101 104 105 Photomask 102 103 Resist 150 Terminal metal layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H092 GA17 JA26 JA46 JB07 JB22 KA10 MA05 MA08 MA12 MA13 MA18 MA27 NA07 NA24 NA29 QA08

Claims (6)

[Claims] And a signal line formed on one of a pair of substrates opposed to each other with a liquid crystal layer interposed therebetween so as to intersect the scanning line with an insulating film interposed therebetween. A thin film transistor formed near an intersection of a scanning line and the signal line; a drain electrode electrically connected to the signal line via the thin film transistor; and an interlayer insulating film formed on the thin film transistor or the signal line And a transmissive electrode and a reflective electrode formed on the interlayer insulating film, a pixel electrode is formed, the pixel electrode is electrically connected to the drain electrode, and the display of each scanning line and each signal line is performed. A method for manufacturing a liquid crystal display device in which a connection electrode is provided on a terminal portion outside a region, wherein the scanning line, the signal line, the thin film transistor, and the connection electrode of a terminal portion are formed on the one substrate. Process and, at least, Interlayer insulating film so as to cover the connection electrode is formed, and forming a reflective electrode over the above and other portions of the interlayer insulating film, to remove the reflective electrode on at least the connection electrode,
Patterning the reflective electrode so that the reflective electrode is present in the display area, and removing the interlayer insulating film on the connection electrode by treatment in O ₂ plasma or O ₂ plasma containing CF ₄ A method for manufacturing a liquid crystal display device, comprising a step of exposing the connection electrode. 2. A step of patterning the reflective electrode so that the reflective electrode is present in the display area and a step of exposing the connection electrode, wherein the reflective electrode in the display area covers the thin film transistor. 2. The liquid crystal display according to claim 1, further comprising the steps of: patterning the reflective electrode; and removing the interlayer insulating film on the connection electrode by plasma treatment to expose the connection electrode. Device manufacturing method. 3. The step of patterning the reflective electrode so that the reflective electrode is present in the display area and the step of exposing the connection electrode are provided in the display area with the reflective electrode covering the thin film transistor. Patterning the reflective electrode so that the reflective electrode is present outside the display region; removing the interlayer insulating film on the connection electrode by plasma treatment to expose the connection electrode; Patterning the reflective electrode so as to remove the reflective electrode existing outside the region. 4. A scanning line, a signal line formed so as to intersect the scanning line with an insulating film interposed therebetween, and one of a pair of substrates arranged to face each other with a liquid crystal layer interposed therebetween; A thin film transistor formed near an intersection of a scanning line and the signal line; a drain electrode electrically connected to the signal line via the thin film transistor; and an interlayer insulating film formed on the thin film transistor or the signal line And a transmissive electrode and a reflective electrode formed on the interlayer insulating film, a pixel electrode is formed, the pixel electrode is electrically connected to the drain electrode, and the display of each scanning line and each signal line is performed. A method for manufacturing a liquid crystal display device in which a connection electrode is provided on a terminal portion outside a region, wherein the scanning line, the signal line, the thin film transistor, and the connection electrode of a terminal portion are formed on the one substrate. Process and, at least, Forming the interlayer insulating film or the metal film so as to cover the transmission electrode, and forming the reflective electrode over the interlayer insulating film or the metal film and over another portion; Removing the reflective electrode portion and patterning the reflective electrode so that the reflective electrode is present in the display region; and removing the interlayer insulating film or the metal film on the transmission electrode by O.
_{2. A} method for manufacturing a liquid crystal display device, comprising a step of exposing the transmissive electrode by performing treatment in ₂ plasma or O ₂ plasma containing CF ₄ . 5. A step of patterning the reflection electrode so that the reflection electrode is present in the display area, and removing the interlayer insulating film or the metal film on the transmission electrode to expose the transmission electrode. Patterning the reflective electrode so that the reflective electrode is present in the display area so as to cover the thin film transistor, and is present outside the outermost peripheral portion of the reflective electrode; and Removing the interlayer insulating film or the metal film on the electrode to expose the transmission electrode; and patterning the reflection electrode so as to remove the reflection electrode existing outside the outermost periphery of the reflection electrode. 5. The method for manufacturing a liquid crystal display device according to claim 4, comprising the steps of: 6. The method according to claim 1, wherein the interlayer insulating film on the connection electrode and the interlayer insulating film on the transmission electrode are removed at the same time.