JP2000047259A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-function integrated liquid crystal display device wherein an area not directly contributing for display is reduced, and also the physical size of the device is reduced, while an area for forming a driving circuit comprising plural elements etc., is secured. SOLUTION: This liquid crystal display device has two facing substrates 1, 2, and at least a semiconductor device group arranged in a matrix form and pixel electrodes 8 connected with the semiconductor device group on one of the substrates, and a driving circuit 9 for driving the semiconductor device group is formed on each of the two facing substrates, respectively. Otherwise, on the substrate facing the substrate where the semiconductor device group is formed, a device forming area is formed where a drive circuit for driving the semiconductor device group or a circuit composed of the semiconductor device group having various functions or both are to be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device such as a liquid crystal display device, and more particularly to a structure of a liquid crystal display device for realizing a light and thin device.

[0002]

2. Description of the Related Art In recent years, semiconductor devices typified by ICs and LSIs, and electronic devices and home appliances incorporating these semiconductor devices have been developed and manufactured, and sold in large quantities on the market. Currently, not only TV receivers, V
TRs, personal computers, and the like are also widely used. These devices have been improved in performance year by year, and have become indispensable in modern society as a tool for providing a lot of information to users with the progress of information society.

[0003] Many of the above-mentioned devices are provided with a means for displaying information for accurately transmitting a large amount of information to a user, a so-called display. Since the type and amount of information are affected, there is a strong interest in the development trends and the like. In particular, in recent years, a liquid crystal display device, particularly a thin film transistor (hereinafter, referred to as a TFT) for each pixel electrode has a thin, lightweight, and low power consumption display.
Called FT. 2. Description of the Related Art Active matrix type liquid crystal display devices provided with a semiconductor element such as) and controlling each pixel electrode have been attracting attention because they have excellent resolution and can obtain clear images.

Hereinafter, the liquid crystal display device will be briefly described as a typical example of the image display device of the present invention.

[0005] As a conventional semiconductor element, a TFT using an amorphous silicon thin film is known.
Many active matrix type liquid crystal display devices equipped with are commercially available. An active matrix type liquid crystal display device equipped with a TFT using the amorphous silicon thin film is going to occupy a mainstream position as a display of OA equipment and consumer equipment.

On the other hand, T using this amorphous silicon thin film
Possibility that as a semiconductor element replacing FT, a pixel TFT for driving a pixel electrode and a driving circuit portion including a TFT for driving the pixel TFT can be integrally formed on one substrate. There is a great expectation for a technology for forming a TFT using a polycrystalline silicon thin film having a thin film.

[0007] The polycrystalline silicon thin film has higher mobility than the amorphous silicon thin film used for the conventional TFT, and it is possible to form a high-performance TFT. In addition, if it is realized that a driving circuit portion for driving the pixel TFT is formed integrally on a single inexpensive glass substrate or the like, it is necessary to separately attach a driving circuit substrate composed of an IC, an LSI, or the like. As a result, the manufacturing cost is greatly reduced as compared with the related art.

[0008] T using such a polycrystalline silicon thin film
As a technique for forming a polycrystalline silicon thin film serving as an FT active layer on a glass substrate or the like, an amorphous silicon thin film is deposited on a glass substrate or the like, and then, at a temperature of about 600 ° C. for several hours to several tens of hours. A solid phase growth method that crystallizes by heat treatment for a long time, or a laser crystallization method that irradiates a pulse laser beam such as an excimer laser to instantly melt and recrystallize the amorphous silicon thin film in that part Proposed.

In this active matrix type liquid crystal display device, an ITO (indium tin ox) is applied to a pixel electrode.
There are a transmissive liquid crystal display device using a transparent conductive thin film such as (ide) and a reflective liquid crystal display device using a reflective electrode made of metal or the like for a pixel electrode.

Since a liquid crystal display device is not a self-luminous display, a transmissive liquid crystal display device is provided with an illuminating device, a so-called backlight, behind the liquid crystal display device so that light incident from the illuminating device can be used. Is displayed. Further, in the case of a reflection type liquid crystal display device, display is performed by reflecting external incident light by a reflection electrode.

In the case of a transmissive liquid crystal display device, since display is performed using a backlight as described above, there is an advantage that a display having high brightness and high contrast can be performed without being greatly affected by ambient brightness and the like. Although there is
The device using this liquid crystal display device has a problem that the power consumption becomes large as a whole. At present, many transmissive liquid crystal display devices are commercialized.

On the other hand, in the case of a reflection type liquid crystal display device, since the above-mentioned backlight is not used, the display brightness and contrast are affected by the use environment or use conditions, that is, the ambient brightness. have. However, except in extreme cases, considering the actual use environment at work or at home, it is considered that the effect is not so great. Since a device using the reflection type liquid crystal display device has an advantage that power consumption as a whole can be extremely reduced, application to a portable information device and the like has been studied.

As described above, in the liquid crystal display device, although the power consumption of the liquid crystal panel itself is very small, the use of the backlight greatly increases the power consumption of the entire device. Therefore, in order to take advantage of a liquid crystal display device that originally consumes low power, practical use of a reflective liquid crystal display device is urgent.

[0014] Also, efforts have been made actively to reduce the external size while increasing the display area occupying the external size of the panel of the liquid crystal display device, that is, to reduce the frame size. This narrowing of the frame is generally realized by reducing a mounting area for connecting a substrate on which a driving circuit for driving a liquid crystal display device is mounted. It is particularly important to reduce the number of external components that are attached to the outside of the liquid crystal display device when aiming for a palmtop-type portable information device or the like.

According to the above-described driving circuit integrated forming technology,
Since the mounting area for connecting the liquid crystal display device to an external circuit can be minimized, the frame is further narrowed.

However, on the other hand, it is possible to improve the function and performance of the liquid crystal display device by creating a circuit having other functions in addition to the drive circuit for performing display or display by the above-described drive circuit integrated formation technology. Requested.

As described above, as the frame becomes narrower, a region for forming a drive circuit and a circuit having other functions on a substrate becomes insufficient.

Thus, for example, Japanese Unexamined Patent Publication No.
As shown in 59802 or JP-A-9-68726, there has been proposed a structure of a liquid crystal display device which can secure a region for forming a driving circuit and a circuit having another function.

Japanese Patent Application Laid-Open No. 7-159802 discloses that
A reflective electrode, a TFT connected to the reflective electrode, and the like are formed inside one substrate constituting a liquid crystal display device, and a drive circuit for driving the TFT and the like is formed outside, that is, on the back surface side. Proposed.

Also, Japanese Patent Application Laid-Open No. 9-68726 discloses that
The TFT connected to the reflective electrode is constituted by an SOI type TFT, the driving circuit is constituted by a bulk silicon type TFT, and they are formed below the reflective electrode, respectively, so that the liquid crystal display device is miniaturized and highly integrated. It has been proposed.

[0021]

According to such a conventional method, a TFT for driving a pixel electrode and a TFT for driving the pixel electrode are provided.
A driving circuit for driving the FT or a circuit having other functions can be efficiently integrated on one substrate, and a narrow frame can be achieved at the same time.

However, Japanese Unexamined Patent Publication No. Hei.
According to the method disclosed in Japanese Patent Application Laid-Open No. 02-206, Japanese Patent Application Laid-Open No. 9-68726, or the like, the following problems may occur.

First, in the liquid crystal display device described in Japanese Patent Application Laid-Open No. 7-159802, a reflection electrode and a TFT connected to the reflection electrode are formed inside one of the substrates constituting the liquid crystal display device. That is, a driving circuit for driving a TFT or the like is formed on the back surface side. In this case, the connection between the TFT and the driving circuit is made by a contact hole provided in the substrate. Usually, a glass substrate is often used for a liquid crystal display device, and its thickness is about 1 mm. It is not easy to open a large number of fine contact holes, whether mechanical or by etching, on this glass substrate. In addition, it is considered that it is necessary to provide a terminal for connecting an IC or the like constituting the drive circuit on the back surface side of the substrate.

Further, if a drive circuit arranged on the back side of the substrate is to be formed by a thin film element similar to a TFT connected to the reflection electrode, the thin film element must be formed on both sides of the substrate. Even if one side is formed and then the other side is formed, an advanced manufacturing method is required,
And it is easily imagined that the manufacturing method becomes complicated.

In the liquid crystal display device described in Japanese Patent Application Laid-Open No. 9-68726, the TFT connected to the
It is composed of an I-type TFT and the driving circuit is a bulk silicon type TFT
The liquid crystal display device is miniaturized and highly integrated by forming them below the reflective electrode. In this case, the SOI is formed on a silicon substrate.
Type TFT and bulk silicon type TFT, it is necessary to make them separately. In that respect, the manufacturing method is considered to be complicated. However, the TFT and the driving circuit are formed on almost the same surface on the substrate, and the It is considered that high integration is realized by arranging it below the reflective electrode.

However, since the TFT and the driving circuit are formed on substantially the same surface on the substrate, a considerable number of wirings and the like are arranged on the substrate surface, and the wirings and the like are complicated. Is imagined, and the area for forming the driving circuit and the like is naturally limited. Therefore, in order to efficiently arrange TFTs and drive circuits, it is necessary to pay close attention to these layouts.

Further, in the above-mentioned conventional method and other methods of the liquid crystal display device, a TFT array and a driving circuit are formed on one glass substrate constituting the liquid crystal display device. In general, only a color filter, a transparent electrode, an alignment film and the like are formed on the other substrate, and no thin film element or the like is formed.

The present invention has been made in view of the above-described problems, and has as its object to reduce the area of a region not directly contributing to the display in a liquid crystal display device to achieve a narrower frame. Another object of the present invention is to provide a multifunctional integrated liquid crystal display device by securing a region for forming a drive circuit including a plurality of elements.

[0029]

According to a liquid crystal display device of the present invention, a semiconductor element group arranged at least in a matrix is provided on an inner surface of one of two opposing substrates. And a liquid crystal display device which performs display by operating the liquid crystal filled between the substrates by the semiconductor element group. A drive circuit for driving the semiconductor element group is formed, whereby the object is achieved.

Further, in the liquid crystal display device of the present invention, at least the semiconductor element group arranged in a matrix and the semiconductor element group are connected to the inner surface of one of the two substrates facing each other. In a liquid crystal display device in which a pixel electrode is formed and a liquid crystal filled between the substrates is operated by the semiconductor element group to perform display, an inner surface of the other substrate facing the substrate on which the semiconductor element group is formed is provided. A driving circuit for driving the semiconductor element group, or a circuit including a semiconductor element group having a function different from that of the driving circuit;
Alternatively, a device formation region in which both are formed is provided, whereby the above object is achieved.

At this time, an interlayer insulating film covering the device formation region is formed on the device formation region,
It is preferable that a metal electrode including the device forming region is formed on the interlayer insulating film.

Further, in the liquid crystal display device of the present invention, at least the semiconductor element group arranged in a matrix and the semiconductor element group are connected to the inner surface of one of the two opposing substrates. In a liquid crystal display device in which a pixel electrode is formed and a liquid crystal filled between the substrates is operated by the semiconductor element group to perform display, the semiconductor element group is formed on the substrate on which the semiconductor element group is formed. A drive circuit for driving the semiconductor element group, a circuit including a semiconductor element group having a function different from that of the drive circuit, or a device formation area in which both are formed are provided below the region. Thus, the above object is achieved.

At this time, an interlayer insulating film covering the device formation region is formed on the device formation region,
It is preferable that the semiconductor element group whose active layer is formed of an amorphous silicon thin film is formed on the interlayer insulating film.

Preferably, a smooth layer for forming a substantially flat surface is provided on the interlayer insulating film formed on the device formation region.

Further, the two opposing substrates are bonded together by a sealing material and are electrically connected by an anisotropic conductive material, and the anisotropic conductive material is attached to a part of the sealing portion. It is desirable that it be used.

The operation of the present invention will be described below.

According to the liquid crystal display device of the present invention, the drive circuit forming region for driving the semiconductor element group used for image display is provided on both of the two opposing substrates, so that the drive circuit on one substrate is provided. The area of the formation region can be further reduced, and the size of the entire liquid crystal display device can be effectively reduced.

Also, a driving circuit for driving the semiconductor element group or a semiconductor element having a function different from that of the driving circuit is provided in a portion corresponding to a display area on the substrate facing the substrate on which the semiconductor element group used for image display is formed. By forming the groups, it is possible to secure a sufficient device formation area without increasing the size of the entire liquid crystal display device.

At this time, a metal electrode is provided so as to cover the device forming region, and reflection display is performed by a pixel electrode connected to a semiconductor element group used for image display, so that the size of the entire liquid crystal display device is not increased. It is possible to secure a sufficient device formation area.

A driving circuit for driving the semiconductor element group or a semiconductor element group having a function different from that of the driving circuit is formed on the substrate side on which the semiconductor element group used for image display is formed and below the semiconductor element group. By doing so, it is possible to secure a sufficient device formation area without increasing the size of the entire liquid crystal display device.

At this time, by providing a smooth layer made of an organic insulating film or an inorganic insulating film on the device formation region or on the interlayer insulating film, unevenness due to elements, wirings and the like can be reduced, and the surface can be flattened. Therefore, a reflective electrode and a semiconductor element formed on the interlayer insulating film can be easily formed.

Further, by forming a semiconductor element group formed on the interlayer insulating film covering the device formation region at a substantially low temperature by using an amorphous silicon thin film, a thermal element applied to the semiconductor element group in the device formation region is provided. The influence is reduced, multifunctional integration can be performed without causing problems such as defects and reduced reliability, and the liquid crystal display device can be highly added.

[0043]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a perspective view showing a configuration of a liquid crystal display device according to Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional view illustrating a configuration of the liquid crystal display device according to the first embodiment of the present invention.

The liquid crystal display device according to the first embodiment has the structure shown in FIG.
As shown in FIG. 2, a display semiconductor element group including a pixel electrode, a TFT for driving each pixel electrode, and the like are arranged in a matrix on a display region 3 of an insulating substrate 1 made of glass or the like. A source line drive circuit and a gate line drive circuit for driving the semiconductor element group are formed in the drive circuit formation region 4. These elements can be easily manufactured by using the above-described polycrystalline silicon thin film.

Next, similarly to the substrate 1, a part of the source line driving circuit or the gate line driving circuit, or one of the driving circuits of both of the driving circuits is formed in the driving circuit forming region 4 of the insulating substrate 2 made of glass or the like. Form a part. As a forming method at this time, the same method as that for the element formed on the substrate 1 side can be used.

Further, at a position corresponding to the display area on the substrate 2 side, a color filter 5, a counter electrode 6 made of a transparent conductive thin film such as ITO and the like are formed. It is needless to say that the drive circuit forming area 4 where a part of the drive circuit is formed is an area other than the display area which does not affect image display.

As shown in FIG. 2, a display semiconductor element 7 for driving each pixel electrode of the liquid crystal display device according to the first embodiment is formed on an island-like semiconductor thin film made of, for example, a polycrystalline silicon thin film. A gate insulating film made of a silicon oxide film or the like, a gate electrode made of Al or the like are sequentially stacked, impurities are introduced into a semiconductor thin film serving as a source region and a drain region by an ion doping method, and an interlayer insulating film made of a silicon nitride film or the like is further provided. And a pixel electrode 8 made of a transparent conductive thin film such as ITO or a metal thin film.

As shown in FIG. 2, the driving semiconductor element 9 constituting the source line driving circuit and the gate line driving circuit is composed of an element in which an n-type impurity is selectively introduced by an ion doping method and a p-type element. An element into which impurities are introduced is formed, and a circuit is formed by these semiconductor elements.

The above-described display semiconductor element 7 and drive semiconductor element 9 can be formed by using a known method, material, or the like. In the first embodiment, a detailed description of the manufacturing process is omitted. . In addition, a coplanar TFT, an inverted staggered TFT, or the like can be used for these semiconductor elements. The manufacturing method and the shape of the element may be appropriately determined as needed.

Finally, the substrate 1 and the substrate 2 are adhered to each other by using a sealing material 12 while keeping a constant interval, and a liquid crystal 10 is injected between the two substrates 1 and 2. These steps are also the same as the conventionally performed method. In addition, the substrate 1 and the substrate 2
Anisotropic conductive resin can be used for the connection portion 11 between the drive circuits formed in the above and the effect of improving the strength of the seal portion 12 and reinforcing it by using it for a part of the seal portion 12. Also have.

The general viewing direction of the liquid crystal display device according to the first embodiment is from the substrate 2 side. In the first embodiment, by dividing the drive circuit forming region 4 for forming the drive circuit into the substrate 1 and the substrate 2, the area of the region occupied by the drive circuit can be made smaller than that of the related art, and the panel has a narrower frame. Has become possible.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described. FIG. 3 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to Embodiment 2 of the present invention.

The liquid crystal display device according to the second embodiment has the structure shown in FIG.
As shown in (1), first, a drive circuit necessary for operating the liquid crystal display device or a unique function not directly involved in the operation of the liquid crystal display device is provided in the device formation region 13 of the insulating substrate 2 made of glass or the like. To form a functional device 14 having the same.

The functional device 14 includes a sensor,
A circuit for performing processing such as amplification, modulation, and conversion of various signals such as a memory, an arithmetic element, a photoelectric conversion device, and an image signal, and an element group and a circuit attached thereto, or formed by functionally connecting these. Devices are considered.

These elements and functional devices 14 can be manufactured using the polycrystalline silicon thin film shown in the first embodiment and a series of semiconductor element forming techniques using the same. Thereafter, an interlayer insulating film 15 made of a silicon oxide film, a silicon nitride film, or a laminated film of these materials is formed, and most of the region on the interlayer insulating film 15, that is, a portion corresponding to the display region 3 is formed from a metal thin film. Reflective electrode 1
6 is formed. For the reflective electrode 16, it is preferable to use a metal thin film having a high reflectance, for example, Al, Ag, or the like. This reflective electrode 16 becomes one electrode of the liquid crystal display device.

Next, the display semiconductor elements 7 composed of TFTs or the like are arranged in a matrix on the substrate 1, and a source line drive circuit and a gate line drive circuit for driving these display semiconductor elements 7 are formed in a drive circuit. Create in area 4. A pixel electrode 8 made of a transparent conductive thin film such as ITO is connected to each of the display semiconductor elements 7 arranged in a matrix.

Finally, the substrate 1 and the substrate 2 are adhered to each other using a sealing material 12 while maintaining a constant interval, and a liquid crystal 10 is injected between the two substrates 1 and 2. These steps are also the same as the conventionally performed method. In addition, the substrate 1 and the substrate 2
Anisotropic conductive resin can be used for the connection portion 11 between the drive circuits formed in the above and the effect of improving the strength of the seal portion 12 and reinforcing it by using it for a part of the seal portion 12. Also have.

The color filter 5 is attached to the front surface of the substrate 1, that is, the surface opposite to the surface on which the group of display semiconductor elements 7 to which the pixel electrodes are connected is formed. The pixel electrodes 8 connected to the seventh group are formed by a photolithography method, an inkjet method, or the like. However, according to the method of attaching a color filter to the front surface of the substrate 1, since the thickness of the substrate is much larger than the distance between the substrates 1 and 2, a parallax is generated depending on the position seen by the observer, and the next color is seen. It is conceivable that color misregistration, such as color shift, may occur and display quality may deteriorate. Therefore, it is desirable that the color filter 5 be formed as much as possible inside the substrate. In the second embodiment, it is formed on the reflective electrode 16.

The general viewing direction of the liquid crystal display device according to the second embodiment is from the substrate 1 side because the display is performed by reflecting the incident light by the reflective electrode 16. In the second embodiment, elements are formed on almost the entire surface of the substrate 2, and the elements can constitute functional devices such as various circuits. These functional devices connect pixel electrodes. Since the semiconductor elements are formed on a different substrate from the matrix-shaped semiconductor element group, the elements, circuits, or wiring for connecting the elements, circuits, and the like can be arranged with a sufficient margin, which facilitates manufacture.

Third Embodiment Next, a third embodiment of the present invention will be described. FIG. 4 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to Embodiment 3 of the present invention.

The liquid crystal display device according to the third embodiment has the structure shown in FIG.
As shown in FIG. 1, first, a source line driving circuit and a gate line driving circuit necessary for operating the liquid crystal display device, a peripheral circuit or a liquid crystal display device are provided in the device forming region 13 of the insulating substrate 1 made of glass or the like. The functional device 14 having a unique function not directly involved in the operation is formed.

The functional device 14 includes a sensor,
A circuit for performing processing such as amplification, modulation, and conversion of various signals such as a memory, an arithmetic element, a photoelectric conversion device, and an image signal, and an element group and a circuit attached thereto, or formed by functionally connecting these. Devices are considered.

These elements and functional devices 14 can be manufactured by using the polycrystalline silicon thin film described in the first embodiment and a series of semiconductor element forming techniques using the same. Thereafter, an interlayer insulating film 15 made of a silicon oxide film, a silicon nitride film, or a laminated film thereof is formed, and an amorphous silicon thin film is deposited on the interlayer insulating film 15 to form the display semiconductor elements 7 in a matrix. Form.

Next, a reflective electrode 16 made of a metal thin film is formed and connected to the display semiconductor element 7. This reflection electrode 1
For 6, a metal thin film having high reflectivity, for example, Al, Ag, or the like is preferably used. This reflective electrode 16 becomes one electrode of the liquid crystal display device. The display semiconductor element group 7 is connected to a drive circuit and the like formed below the interlayer insulating film 15 through a contact hole and the like formed in the interlayer insulating film 15.

In the third embodiment, the configuration is such that a group of display semiconductor elements 7 made of an amorphous silicon thin film is formed on the interlayer insulating film 15. In this case, in addition to the amorphous silicon thin film, a polycrystalline silicon thin film or the like is used. Can also be used. However, when a polycrystalline silicon thin film is obtained by applying heat treatment such as laser irradiation to the amorphous silicon thin film to crystallize the amorphous silicon thin film, it is necessary to go through a higher temperature process than the amorphous silicon thin film in terms of thermal history. For this reason, there is a concern that an element formed below the interlayer insulating film 15 or the functional device 14 may be adversely affected. Therefore, when an element is formed on the interlayer insulating film 15, it is desirable to use an amorphous silicon thin film. Needless to say, a polycrystalline silicon thin film may be used as long as the effect on elements formed below the interlayer insulating film 15 and the functional device 14 can be reduced as much as possible by performing effective heat insulation.

Next, a counter electrode 6 made of a transparent conductive thin film such as ITO is formed on at least a portion corresponding to the display area 3 of the substrate 2. In addition to the portion corresponding to the display area 3 of the substrate 2, peripheral circuits and functional devices formed of a polycrystalline silicon thin film may be formed.

Finally, the substrate 1 and the substrate 2 are adhered to each other by using a sealing material 12 while keeping a constant interval, and a liquid crystal 10 is injected between the two substrates 1 and 2. These steps are also the same as the conventionally performed method. In addition, the substrate 1 and the substrate 2
Anisotropic conductive resin can be used for the connection portion 11 between the drive circuits formed in the above and the effect of improving the strength of the seal portion 12 and reinforcing it by using it for a part of the seal portion 12. Also have.

The color filter 5 may be bonded to the front surface of the substrate 2, that is, the surface opposite to the surface on which the counter electrode 6 is formed, or may be formed on the inner surface of the substrate 2 and then formed on the counter electrode 6. In addition, a photolithography method may be used on the reflective electrode 16 connected to the display semiconductor element 7 group.
It may be formed by an inkjet method or the like. However, according to the method of attaching a color filter to the front surface of the substrate 2, since the thickness of the substrate is much larger than the distance between the substrates 1 and 2, parallax is generated depending on the position viewed by the observer, and the next color is seen. It is conceivable that color misregistration, such as color shift, may occur and display quality may deteriorate. Therefore, it is desirable that the color filter 5 be formed as much as possible inside the substrate. In the third embodiment, the counter electrode 6 is formed after the color filter 5 is formed on the inner surface of the substrate 2.

The general observation direction of the liquid crystal display device according to the third embodiment is from the substrate 2 side because the display is performed by reflecting the incident light by the reflection electrode 16. In the third embodiment, elements are formed on almost the entire surface of the substrate 1, and the elements can constitute functional devices such as various circuits. These functional devices connect pixel electrodes. Since the semiconductor elements are formed in a different layer from the matrix-like semiconductor element group, the layout of the elements and circuits or the wiring for connecting the elements and circuits can be afforded, and the manufacture is easy. Further, in the above-described second embodiment, the aperture ratio in the display area is somewhat reduced due to the wiring portion of the semiconductor element group formed on the substrate 2, but in the third embodiment, the semiconductor element group is directly reflected by the semiconductor element group. Since the electrodes are connected, it is possible to prevent a decrease in the aperture ratio.

(Embodiment 4) Next, Embodiment 4 of the present invention will be described. FIGS. 5 and 6 are cross-sectional views showing the configuration of the element portion of the liquid crystal display device according to Embodiment 4 of the present invention.

The liquid crystal display device according to the fourth embodiment has the structure shown in FIG.
As shown in FIG. 1, first, a source line driving circuit and a gate line driving circuit necessary for operating the liquid crystal display device, a peripheral circuit or a liquid crystal display device are provided in the device forming region 13 of the insulating substrate 1 made of glass or the like. The functional device 14 having a unique function not directly involved in the operation is formed. Since these are the same as the other embodiments described above, detailed description will be omitted.

Subsequently, an interlayer insulating film 15 made of a silicon oxide film, a silicon nitride film, or a laminated film thereof is formed, and thereafter, an acrylic resin or a polyimide resin is applied to form a smooth layer 17. The purpose of this smooth layer 17 is to flatten the unevenness of the surface of the interlayer insulating film 15 and is formed to have a thickness of about 1 μm to 2 μm. Note that the thickness of the smooth layer 17 may be appropriately determined according to the degree of unevenness of the lower layer, and the above-described values are examples, and are not limited thereto.

Next, the reflection electrode 16 is formed on the smoothing layer 17. Due to the smoothing layer 17, the surface of the reflective electrode 16 becomes substantially flat. Therefore, the incident light is uniformly reflected in any region, so that it is possible to realize uniform brightness, color reproducibility, and the like when performing display.

FIG. 6 shows an example of a configuration in which the display semiconductor element 7 is formed on the smoothing layer 18. In this case, the smoothing layer 18 is made of a silicon oxide film, a silicon nitride film, or the like. The deposited inorganic insulating film was formed by etching so as to fill the concave portion with the insulating film. As described above, as the smooth layer 17,
It was formed using an acrylic resin or a polyimide resin.

It is also possible to use a material having a certain degree of heat resistance such as a polyimide resin for the smooth layer 18. The polyimide resin has a heat resistance of about 350 ° C. If the display semiconductor element 7 to be formed is constituted by a TFT or the like using an amorphous silicon thin film,
It is also possible to form at a maximum process temperature of about 350 ° C. or lower. Therefore, it is possible to form the display semiconductor element 7 thereon without damaging the smooth layer 18.

Although acrylic resin and polyimide resin are shown as the smooth layers 17 and 18, the material may be determined as appropriate, and is not limited to these.
In the fourth embodiment, it is preferable that the smooth layers 17 and 18 have high heat resistance.

[0078]

As described above, according to the present invention, a drive circuit forming region for forming a drive circuit for driving a display semiconductor element is provided on both of two substrates constituting a liquid crystal display device. Alternatively, a device formation region for forming a drive circuit or a functional device is provided on a substrate side opposite to a substrate on which a display semiconductor element is formed, or a drive circuit or a function device is formed below a display region for forming a display semiconductor element. By providing the device formation region, it is possible to reduce the area of a region where a drive circuit for driving a display semiconductor element is formed as compared with the related art.

Further, the external dimensions of the liquid crystal display device can be reduced, and a driving circuit and a function are provided below a portion corresponding to a display region on the opposite substrate side or a display semiconductor element group formed in the display region. By providing a device formation region for forming a device, various functions can be integrated in addition to the function as a display device. Therefore, without increasing the external dimensions of the liquid crystal display device more than necessary, Functionalization can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a configuration of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to Embodiment 1 of the present invention.

FIG. 3 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 4 is a sectional view illustrating a configuration of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to Embodiment 4 of the present invention.

FIG. 6 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to Embodiment 4 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Substrate 3 Display area 4 Driving circuit formation area 5 Color filter 6 Counter electrode 7 Display semiconductor element 8 Pixel electrode 9 Driving semiconductor element 10 Liquid crystal 11 Connection part 12 Seal part 13 Device formation area 14 Functional device 15 Interlayer insulating film 16 reflective electrode 17 smooth layer 18 smooth layer

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Claims (7)

[Claims] At least one semiconductor element group arranged in a matrix and a pixel electrode connected to the semiconductor element group are formed on an inner surface of one of two opposing substrates. In a liquid crystal display device which performs display by operating a liquid crystal filled between substrates by the semiconductor element group, a driving circuit for driving the semiconductor element group is provided on each of inner surfaces of the two opposite substrates. A liquid crystal display device characterized by being formed. 2. A semiconductor element group arranged at least in a matrix and a pixel electrode connected to the semiconductor element group are formed on an inner surface of one of two opposing substrates. In a liquid crystal display device that performs display by operating a liquid crystal filled between substrates by the semiconductor element group, the semiconductor element group is driven on an inner surface of the other substrate facing the substrate on which the semiconductor element group is formed. A liquid crystal display device provided with a device formation region in which a driving circuit for performing the driving, a circuit including a semiconductor element group having a function different from that of the driving circuit, or both of them are provided. 3. An inter-layer insulating film covering the device forming region is formed on the device forming region, and a metal electrode including the device forming region is formed on the inter-layer insulating film. The liquid crystal display device according to claim 2. 4. A semiconductor element group arranged at least in a matrix and a pixel electrode connected to the semiconductor element group are formed on an inner surface of one of the two substrates facing each other. In a liquid crystal display device which performs display by operating the liquid crystal filled between the substrates by the semiconductor element group, the semiconductor element group is formed on a substrate below a region where the semiconductor element group is formed on the substrate. A liquid crystal display provided with a device formation region in which a driving circuit for driving a semiconductor element group, a circuit including a semiconductor element group having a function different from that of the driving circuit, or both of them is provided. apparatus. 5. An interlayer insulating film covering the device forming region is formed on the device forming region, and the semiconductor element group in which an active layer is formed of an amorphous silicon thin film is formed on the interlayer insulating film. 5. The method according to claim 4, wherein
3. The liquid crystal display device according to 1. 6. The liquid crystal display according to claim 2, wherein a smooth layer that forms a substantially flat surface is provided on the interlayer insulating film formed on the device formation region. apparatus. 7. The two opposing substrates are bonded together by a sealant and electrically connected by an anisotropic conductive material, and the anisotropic conductive material is attached to a part of the seal portion. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is used.