JP2016012152A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device having a novel structure.SOLUTION: The display device includes: an island-shaped electrode that can be electrically connected with a pixel electrode; and a signal line. The island-shaped electrode is electrically connected to one of the source region and drain region of a transistor. The signal line is electrically connected to the other of the source region and drain region of the transistor. The island-shaped electrode is formed through the same step as the one for etching the signal line.

Description

The present invention relates to a semiconductor device having a circuit formed of a thin film transistor (hereinafter referred to as TFT) and a method for manufacturing the semiconductor device. For example, the present invention relates to an electro-optical device typified by a liquid crystal display panel and an electronic apparatus in which such an electro-optical device is mounted as a component.

Note that in this specification, a semiconductor device refers to all devices that can function by utilizing semiconductor characteristics, and an electro-optical device, a semiconductor circuit, and an electronic device are all semiconductor devices.

In recent years, a technique for forming a thin film transistor (TFT) using a semiconductor thin film (having a thickness of about several to several hundred nm) formed on a substrate having an insulating surface has attracted attention. Thin film transistors are widely applied to electronic devices such as ICs and electro-optical devices. In particular, development of thin film transistors as switching elements for liquid crystal display devices is urgently required.

In a liquid crystal display device, in order to obtain a high-quality image, an active matrix type liquid crystal display device in which pixel electrodes are arranged in a matrix and a TFT is used as a switching element connected to each pixel electrode has attracted attention.

In this active matrix liquid crystal display device, in order to display a good quality, it is necessary to hold the potential of the video signal in each pixel electrode connected to the TFT until the next writing. Generally, a storage capacitor (Cs) in a pixel
Is provided to hold the potential of the video signal.

Various proposals have been made for the structure of the storage capacitor (Cs) and its formation method. From the viewpoint of simplicity of the manufacturing process and reliability, an insulating film having the highest quality among the insulating films constituting the pixel is proposed. It is desirable to use the gate insulating film of the TFT as a dielectric of the storage capacitor (Cs). Conventionally, as shown in FIG. 9, a capacitor wiring serving as an upper electrode is provided using a scanning line, and an upper electrode (capacitor wiring) / dielectric layer (gate insulating film) is provided.
/ The storage capacitor (Cs) is configured by the lower electrode (semiconductor film).

In addition, from the viewpoint of display performance, the pixel is required to have a large storage capacity and to have a high aperture ratio. Since each pixel has a high aperture ratio, the light utilization efficiency of the backlight is improved, and the backlight capacity for obtaining a predetermined display luminance can be suppressed. As a result, power saving and downsizing of the display device can be achieved. Further, since each pixel has a large storage capacity, the display data retention characteristic of each pixel is improved, and the display quality is improved. In addition, when the display device is driven dot-sequentially, a signal holding capacitor (sample hold capacitor) is also required on the drive circuit side of each signal line, but each sample pixel has a large holding capacitor. The area occupied by the capacity can be reduced, and the display device can be downsized.

Such a requirement is a major issue in the advancement of miniaturization of each display pixel pitch associated with higher definition (increase in the number of pixels) and downsizing of a liquid crystal display device.

In addition, the conventional pixel configuration described above has a problem that it is difficult to achieve both a high aperture ratio and a large storage capacity.

FIG. 9 shows a conventional example in which a conventional pixel configuration is implemented with a pixel size of 19.2 μm square according to the design rules in Table 1.

The two wiring lines (scanning line and capacitive wiring line) are arranged in parallel because the two scanning lines and the capacitive wiring line are continuously formed. In FIG. 9, 10 is a semiconductor film, 11 is a scanning line, 12 is a signal line, 13 is an electrode, and 14 is a capacitor wiring. FIG. 9 is a simplified top view of the pixel, and the pixel electrode connected to the electrode 13 and the contact hole reaching the electrode 13 are not shown.

In the case of such a storage capacitor configuration with an upper electrode (capacitance wiring) / dielectric layer (gate insulating film) / lower electrode (semiconductor film), circuit elements (pixel TFT, storage capacitor,
All of the contact holes and the like are related to the gate insulating film, and these element elements are arranged almost planarly in each pixel.

For this reason, in order to obtain both a high aperture ratio and a large storage capacity for each pixel within a specified pixel size, it is essential to efficiently lay out circuit elements necessary for the circuit configuration of the pixel. In other words, it is essential to improve the utilization efficiency of the gate insulating film because all circuit elements are related to the gate insulating film.

From this point of view, FIG. 10 shows the planar layout efficiency in the circuit configuration of the pixel in the example of FIG. In FIG. 10, reference numeral 21 denotes a single pixel region, 22 denotes a pixel opening region, 23 denotes a storage capacitor region, 24 denotes an A region, and 25 denotes a part of the TFT and a contact region.

In FIG. 10, the area of the pixel opening region 22 is 216.7 μm ² (aperture ratio 58.8%), the area of the storage capacitor region 23 is 64.2 μm ² , and the area of the TFT portion and contact region 25 is 42.2 μm.
m ² , and the area of the A region 24 is 34.1 μm ² .

This A region 24 is a separation region of the scanning line and the capacitive wiring resulting from the parallel arrangement of the wiring portion, the scanning line, and the capacitive wiring that interconnect the regions acting as the gate electrodes of the TFT. The gate insulating film in the region is not given an original function, which causes a reduction in layout efficiency.

Further, in the case of the above structure, there is a problem that the requirement for the capacitance wiring resistance becomes severe.

In normal liquid crystal display driving, the potential of the video signal is applied to each of the plurality of pixels connected to each scanning line continuously (in the case of dot sequential driving) or simultaneously (in the case of line sequential driving) in the scanning line direction. Writing is performed.

In this case, in the above pixel configuration, since the capacitor wiring is arranged in parallel to the scanning line, a plurality of pixels connected to each scanning line are connected to the common capacitor wiring. In this case, the counter current corresponding to the pixel writing current flows continuously or simultaneously for a plurality of pixels, and the capacitance wiring resistance needs to be lowered sufficiently in order to avoid deterioration in display quality due to potential fluctuation of the capacitance wiring. There is.

However, increasing the line width in order to reduce the resistance of the capacitor wiring resistance increases the area occupied by the storage capacitor, while impairing the aperture ratio of the pixel.

The present invention provides a solution from the design side to the above-mentioned problem, ensuring a sufficient holding capacity (Cs) while obtaining a high aperture ratio, and at the same time, loading the capacity wiring (pixel writing current) in terms of time. It is intended to provide a liquid crystal display device having high display quality by dispersing and effectively reducing.

The structure of the invention disclosed in this specification includes a semiconductor film on an insulating surface, a first insulating film (gate insulating film) on the semiconductor film, and a gate electrode and a first wiring (capacitor on the first insulating film). Wiring), a second insulating film on the gate electrode and the first wiring, a second wiring (scanning line) connected to the gate electrode on the second insulating film, and a third on the second wiring. A semiconductor device having an insulating film, wherein the first wiring and the second wiring overlap with each other through the second insulating film, and the first wiring through the second insulating film In a region where the second wiring and the second wiring overlap, a storage capacitor using the second insulating film as a dielectric is formed.

According to another aspect of the invention, there is provided a semiconductor film on an insulating surface, a first insulating film (gate insulating film) on the semiconductor film, and a gate electrode and a first wiring (capacitive wiring) on the first insulating film. A second insulating film on the gate electrode and the first wiring, a second wiring (scanning line) connected to the gate electrode on the second insulating film, and a third insulating film on the second wiring And the first wiring and the semiconductor film overlap with each other via the first insulating film, and the first wiring and the semiconductor via the first insulating film In the region where the film overlaps, the first
A storage capacitor using the insulating film as a dielectric is formed.

Also in the above configuration, the first wiring and the second wiring overlap through the second insulating film, and the first wiring and the second wiring overlap through the second insulating film. In the region, a storage capacitor using the second insulating film as a dielectric is formed.

In each of the above structures, an impurity element imparting a conductivity type is added to a region of the semiconductor film that overlaps with the first wiring with the first insulating film interposed therebetween.

In each of the above-described configurations, the first wiring is arranged in a direction orthogonal to the second wiring.

In each of the above structures, a third wiring (signal line) in contact with the semiconductor film is provided on the third insulating film, and a region of the semiconductor film in contact with the third wiring is , A source region or a drain region.

In each of the above structures, a pixel electrode that is electrically connected to the semiconductor film is provided.

In each of the above configurations, the first wiring is arranged in a direction parallel to the third wiring.

In each of the above structures, the gate electrode is formed in a different layer from the scanning line.

  In each of the above structures, the gate electrode is patterned in an island shape.

In addition, in the configuration of the invention for realizing the above structure, an island-shaped semiconductor film is formed on a substrate, a first insulating film (gate insulating film) is formed on the island-shaped semiconductor film, and an island-shaped semiconductor film is formed. Forming a gate electrode and a capacitor wiring; forming a second insulating film covering the gate electrode and the capacitor wiring; and selectively etching the second insulating film to form a first contact hole reaching the gate electrode. Forming a scanning line in contact with the gate electrode on the second insulating film; forming a third insulating film on the scanning line; and selectively etching the third insulating film to form the semiconductor film Second to reach
A method for manufacturing a semiconductor device is characterized in that a contact hole is formed and a signal line electrically connected to the semiconductor film is formed.

In the above structure, it is preferable that after the first insulating film is formed over the semiconductor film, the second insulating film overlapping the scanning line is partially thinned.

According to the present invention, an area (corresponding to area A in FIG. 10) that has been conventionally used as a wiring area in a scanning line and a scanning line / capacitance wiring separation area can be used as a storage capacitor. A plurality of pixels connected to each other have independent capacitance wiring, so that each pixel is not affected by the write current of the adjacent pixel even when signal writing is performed continuously or simultaneously with the adjacent pixel. Furthermore, since the current load is distributed over time in each capacitor wiring, the effective load is reduced and the requirement for the capacitor wiring resistance is eased.

Therefore, according to the liquid crystal display device using the present invention, a liquid crystal display element having both a high aperture ratio and a sufficient display signal potential holding capacity in each pixel can be obtained, while achieving downsizing and power saving of the device. A good display image can be obtained.

FIG. 3 is a cross-sectional structure diagram of an active matrix liquid crystal display device. The figure which shows the circuit of a TFT substrate. The top view of a pixel and the figure which shows a pixel opening area. The figure which shows pixel sectional drawing. The figure which shows a pixel top view and sectional drawing. (Example 2) The figure which shows the external appearance of AM-LCD. FIG. 14 illustrates an example of an electronic device. FIG. 14 illustrates an example of an electronic device. FIG. The figure which shows the conventional pixel opening area | region.

  Embodiments of the present invention will be described below.

The present invention is characterized in that in order to improve the aperture ratio and increase the storage capacitor, a scan line is formed in a layer different from the gate electrode, and the storage capacitor is formed using the scan line as an upper electrode.

In this specification, the gate electrode is patterned in an island shape, and is connected to a scanning line on the second insulating film through a contact hole formed in the second insulating film.

In the present invention, the storage capacitor has a configuration in which the lower electrode is a semiconductor film, the dielectric is a first insulating film (gate insulating film), and the upper electrode is a capacitor wiring. It is desirable to reduce the resistance of the region overlapping with the capacitor wiring through the first insulating film in the same manner as the source region and the drain region. Further, a part of the first insulating film which is in contact with and overlaps with the capacitor wiring may be thinned to increase the storage capacitor.

In the present invention, as shown in FIG. 1, the scanning line 107 is formed in the upper layer of the gate electrode 104, and the capacitor is formed using the second insulating film 106 in contact with the gate electrode as a dielectric. This capacitor has a structure in which the lower electrode is the capacitor wiring 105, the dielectric is the second insulating film 106, and the upper electrode is the scanning line 107.

Further, in the present invention, unlike the conventional case (capacitor wiring is parallel to the scanning line), the capacitor wiring 105 is arranged in parallel to the signal lines 109 and 111 as shown in FIG. Accordingly, video signals are continuously written to the pixels corresponding to the respective scanning lines from the driving method, and at this time, the corresponding pixels are connected to the independent capacitance wirings (capacitatively), so that they are adjacent to each other. Variations in the capacitor wiring potential due to pixel writing current can be avoided, and a good display image can be obtained.

Also, for the same reason, the required performance on the capacitance wiring resistance is eased, so the design flexibility of the layout, size, and film thickness of the capacitance wiring increases, and the range of selection of the capacitance wiring material increases, and the design difficulty and Manufacturing difficulty is reduced, leading to higher manufacturing yield.

The present invention having the above-described configuration will be described in more detail with the following examples.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1 by taking a projection-type dot sequential liquid crystal display device as an example.

An active matrix liquid crystal display device using a TFT as a switching element has a structure in which a substrate (TFT substrate) in which pixel electrodes are arranged in a matrix and a counter substrate on which a counter electrode is formed are arranged to face each other through a liquid crystal layer. It has become. The distance between the two substrates is controlled to a predetermined interval via a spacer or the like, and a liquid crystal layer is sealed by using a sealing material on the outer periphery of the display area.

FIG. 1 is a cross-sectional structure diagram showing an outline of the liquid crystal display device of this embodiment. In FIG.
1 is a substrate (TFT substrate), 102 is a semiconductor film, 103 is a gate insulating film (first insulating film), 1
04 is a gate electrode, 105 is a capacitor wiring, 106 is a second insulating film, 107 is a scanning line, 108 is a third insulating film, 109 and 111 are electrodes and signal lines branched from signal lines, and 110 is connected to a pixel electrode. Electrode.

Note that in this specification, an “electrode” is a part of “wiring” and refers to a portion where electrical connection with another wiring is made or a portion intersecting with a semiconductor layer. Therefore, for convenience of explanation, “wiring” and “electrode” are used properly, but “wiring” is always included in the term “electrode”.

In the present specification, TFTs (switching elements) are defined as portions indicated by 102 to 110. Further, in 109 and 110, an electrode branched from the wiring or a wiring may be used.

Reference numeral 112 denotes a fourth insulating film covering the TFT, 113 denotes a light shielding film for preventing light deterioration of the TFT, 11
4 is a fifth insulating film, 115 is a pixel electrode connected to the TFT, and 116 is an alignment film for aligning the liquid crystal layer 117.

In FIG. 1, the counter electrode 119 and the alignment film 118 are provided on the counter substrate 120, but a light shielding film and a color filter may be provided as necessary.

As shown in FIG. 2, the substrate (TFT substrate) 101 includes a display area 201, a scanning line driving circuit 202 and a signal line driving circuit 203 formed around the display area 201.

The scanning line driving circuit 202 is mainly configured by a shift register that sequentially transfers scanning signals. The signal line driver circuit 203 is mainly composed of a shift register and a sample hold circuit that samples and holds a video signal input based on the shift register output and drives the signal line.

In the display area 201, a plurality of scanning lines (gate lines) 207 connected to the scanning line driving circuit 202 and arranged in parallel with each other at a predetermined interval, and connected to the signal line driving circuit 203 and arranged in parallel with each other at a predetermined interval. The plurality of signal lines 208 are arranged so as to intersect with each other, and TFTs are disposed at respective positions where the signal lines 208 intersect with each other, and pixel electrodes are disposed in respective regions partitioned by the scanning lines and the signal lines. . With this configuration, the pixel electrodes are arranged in a matrix. A plurality of capacitor wirings 209 connected to GND (ground) or a fixed potential are provided in parallel with the signal line 208. In FIG. 2, only a few signal lines, scanning lines, and capacitor wirings are shown for simplification.

Hereinafter, a manufacturing process of the semiconductor device illustrated in FIGS. In the description, FIG.
3 (b) and 4 are also used.

First, a quartz substrate or a plastic substrate can be used for the substrate 101 in addition to a glass substrate. When a glass substrate is used, heat treatment may be performed in advance at a temperature lower by about 10 to 20 ° C. than the glass strain point. In order to prevent impurity diffusion from the substrate 101, a base film made of an insulating film such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film is preferably formed on the surface of the substrate 101 where the TFT is formed.

Next, a semiconductor film having a thickness of 25 to 80 nm (preferably 30 to 60 nm) is formed into a plasma CV.
Semiconductor film 1 formed by a known method such as D method or sputtering method and patterned into a desired shape
03 is formed. In this embodiment, an amorphous silicon film having a thickness of about 50 nm is formed by plasma CVD, and a crystallization process is performed by a known method to form a crystalline silicon film (poly-S).
After forming i), patterning was performed in an island shape. In this embodiment, a crystalline silicon film (p
oli-Si) is used, but there is no particular limitation as long as it is a semiconductor film.

Note that in this specification, a “semiconductor film” refers to a single crystal semiconductor film, a crystalline semiconductor film (p
oli-Si or the like), an amorphous semiconductor film (a-Si or the like), or a microcrystalline semiconductor film, and also includes a compound semiconductor film such as a silicon germanium film.

Next, an insulating film containing silicon formed by a plasma CVD method or a sputtering method,
Alternatively, the first insulating film (gate insulating film) 103 is formed using an oxide film formed by thermal oxidation of a semiconductor film (Si film or the like). The first insulating film 103 may have a laminated structure including a plurality of layers such as two layers or three layers as necessary.

Next, a conductive film is formed over the first insulating film 103 and patterned to form the gate electrode 104 and the capacitor wiring 105. The gate electrode 104 and the capacitor wiring 105 are made of poly-Si or WSi _x (X = 2.0 to 2.... Doped with an impurity element imparting conductivity type.
8) It is formed with a film thickness of about 300 nm by a conductive material such as Al, Ta, W, Cr, Mo and its laminated structure. The gate electrode 104 and the capacitor wiring 105 may be formed as a single layer, but may have a stacked structure including a plurality of layers such as two layers or three layers as necessary.

Next, using each island-shaped semiconductor film 104, the function of a video signal writing switch is obtained.
In order to form T, an impurity element (such as phosphorus or boron) that selectively imparts n-type or p-type to the semiconductor film 104 is added using a known technique (ion doping method, ion implantation method, or the like) A low resistance source region and drain region and a low resistance region are formed. This low resistance region is a part of the semiconductor film which has been reduced in resistance by adding an impurity element (typically phosphorus or boron) in the same manner as the drain region. Note that the order of steps in which the impurity element is selectively added is not particularly limited, and may be, for example, before the first insulating film is formed, before the gate electrode is formed, or after the gate electrode is formed. In addition, the LDD region and the offset region may be formed according to the circuit. For simplification, each region is not shown.

Thus, a channel formation region sandwiched between the source region and the drain region is formed. On the channel formation region of each pixel, the gate electrode 104 is arranged in an island shape with the first insulating film 102 interposed therebetween. Capacitance wirings are respectively disposed on the low resistance regions. In addition, the capacitor wiring is continuously arranged in the signal line direction for each pixel, and is electrically grounded or connected to a fixed potential outside the display area. In this embodiment, in order to increase the capacitance, a part of the first insulating film 102 in contact with the capacitor wiring is thinned before the capacitor wiring is formed.

Next, a second insulating film 106 that covers the gate electrode and the capacitor wiring is formed. As the second insulating film 106, an insulating film containing silicon formed by a plasma CVD method, a sputtering method, or the like is used. In addition, the second insulating film 106 may be formed of a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or a stacked film combining these.

Next, the second insulating film 106 is selectively etched to form a first contact hole reaching the island-shaped gate electrode.

Next, a conductive film is formed over the second insulating film 106 and patterned to form the scanning line 107. The scanning line 107 is connected to each island-shaped gate electrode through a first contact hole formed in the second insulating film 106, and is arranged to shield the periphery of the channel formation region. The scanning line 107 is formed with a thickness of about 100 nm using a light-shielding conductive material film such as WSi _x , W, Cr, or Al, or a laminated film of WSi _x / poly-Si. The scanning line 107 is connected to a scanning line driving circuit.

Next, a third insulating film 108 that covers the scanning lines is formed. The third insulating film 108 may be formed of an organic insulating material film, a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or a laminated film combining these.

Next, the first insulating film 103, the second insulating film 106, and the third insulating film 108 are selectively etched to form second contact holes that reach the semiconductor film (source region or drain region).

Next, a film containing Al, W, Ti, TiN as a main component or a conductive film (thickness: 500 μm) having a laminated structure thereof is formed on the third insulating film 108 and patterned to perform signal line 109. 111 and an island-shaped electrode 11 for connecting to a pixel electrode to be formed later
0 is formed. The signal line 109 is connected to the source region or the drain region through the second contact hole reaching the semiconductor film. Similarly, the island-shaped electrode 110 is connected to the source region or the drain region through the second contact hole reaching the semiconductor film. Further, the island-shaped electrode 110 is disposed separately from the signal lines 109 and 111. However, neither the signal line nor the island-shaped electrode is connected to the source region. Similarly, neither the signal line nor the island-shaped electrode is connected to the drain region.

A top view of the pixel at this stage corresponds to FIG. 3A, and a schematic cross-sectional view taken along the dotted line AA ′ in FIG. 3A corresponds to FIG. FIG. 4B corresponds to a schematic cross-sectional structure diagram cut along the dotted line BB ′ in FIG. The same symbols are used for the same parts in each figure.

Next, a fourth insulating film 112 that covers the signal line and the island-shaped electrode is formed. This fourth insulating film 1
12 may be formed of an organic insulating material film, a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or a laminated film combining these.

Next, a light shielding film 113 is formed on the fourth insulating film 112 by patterning a film having high light shielding properties such as Ti, Al, W, Cr, or black resin into a desired shape. The light shielding film 113 is arranged in a mesh shape so as to shield light other than the opening of the pixel.

In this embodiment, the light shielding film 113 is electrically floating, but when a low resistance film is selected as the light shielding film material, the light shielding film can be controlled to an arbitrary potential outside the display portion.

Next, a fifth insulating film 114 is formed over the light shielding film 113. The fifth insulating film 114 may be formed of an organic insulating material film. Note that the surface can be satisfactorily planarized by forming the fifth insulating film 114 of an organic insulating material. In addition, since the organic resin material generally has a low dielectric constant, parasitic capacitance can be reduced. However, since it is hygroscopic and is not suitable as a protective film, a stacked structure combined with a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or the like may be used.

Next, the fourth insulating film 112 and the fifth insulating film 114 are selectively etched to form a third contact hole reaching the island-shaped electrode 110.

Next, a transparent conductor film such as ITO is formed and patterned to form the pixel electrode 1.
15 is formed. The pixel electrode 115 is connected to the island-shaped electrode 110 through the third contact hole reaching the island-shaped electrode 110. Each pixel electrode is independently arranged so as to cover the pixel opening.

By using the manufacturing process as described above and further arranging wiring, a semiconductor film, a contact hole and the like as shown in FIG. 8μm area of ² of the pixel opening region 300 (opening ratio 61.5%) and the storage capacitor region 301a, 301b area 83.4Myuemu ² was obtained. FIG. 3B shows the arrangement of the third contact holes 303 with the pixel electrodes.

The area of the TFT portion and the contact region 302 is almost the same as that in the conventional example, and the area (A) conventionally used as a scanning line / signal line separation region and a gate connection wiring region of the TFT (A
It can be seen that the (region) is converted into the pixel opening and the storage capacitor in this configuration.

By efficiently using such a limited pixel region, both a high aperture ratio and a large storage capacity area can be achieved.

Further, according to this configuration, video signals are continuously written to the pixels corresponding to the scanning lines from the driving method, and at this time, the corresponding pixels are respectively connected to the independent capacitance wirings (capacitatively).
Since they are connected, fluctuations in the capacitance wiring potential due to the write current of adjacent pixels can be avoided, and a good display image can be obtained.

In addition, for the same reason, the required performance on the capacitance wiring resistance is relaxed, so the design flexibility of the layout, size, and film thickness of the capacitance wiring is increased, and the selection range of the capacitance wiring material is widened. The difficulty level will be reduced, leading to higher production yields.

Further, in this embodiment, for the sake of convenience, the light shielding film is provided. However, by applying a material having high light shielding properties to the scanning lines, regions other than the pixel openings that should be originally shielded and channel formation of the island-like Si film are formed. Since the layout can be made so that the peripheral portion of the region is completely shielded by the scanning lines and the signal lines, the manufacturing process can be simplified as a structure without the upper shielding film.

In the present embodiment, an island-shaped electrode (second electrode) is separated from the scanning line in each pixel simultaneously with the formation process of the scanning line formed on the first insulating film in the configuration of the first embodiment. It is an additional formation. FIG. 5A shows a top view of the pixel of this example, and FIG. 5B shows a cross-sectional view taken along the line CC ′ in FIG. 5A. In addition, since only the presence or absence of the second electrode is different from Example 1, the same reference numerals are used for the same parts.

As shown in FIGS. 5A and 5B, the second electrode 501 is electrically connected to the source region formed in the island-like Si film 102 through the contact hole opened in the first insulating film. Connecting. In addition, the second electrode 501 is disposed so as to overlap the capacitor wiring.

With this configuration, the second electrode 501 can be used as the upper electrode, the first insulating film can be used as the dielectric, and the capacitor electrode can be used as the lower electrode, so that the second holding capacitor can be formed and the video signal holding characteristics can be further improved. it can. In addition, the display device can be reduced in size.

In addition, the region where the second electrode 501 and the capacitor wiring formed in this embodiment overlap with each other overlaps the first capacitor electrode region on the plane, and the contact hole region to the island-shaped Si is the pixel electrode line and the source. Since the contact hole region connecting the regions can be arranged so as to overlap the plane, the aperture ratio is not impaired.

With this configuration, the pixel aperture of 226.8 μm ² (the aperture ratio of 6) is the same as that of the first embodiment.
1.5%) and a first storage capacity area of 83.4 μm ² , in addition to a second storage capacity area of 45.0 μm ²
Have gained.

In this embodiment, the structure of the active matrix liquid crystal display device shown in Embodiment 1 will be described with reference to the perspective view of FIG. In addition, the same code | symbol is used for the part corresponding to Example 1. FIG.

In FIG. 6, the active matrix substrate is a pixel portion 801 formed on the substrate 101.
And a scanning line driving circuit 802, a signal line driving circuit 803, and other signal processing circuits. A pixel TFT 800 connected to the pixel electrode 115, a first storage capacitor 200, and a second storage capacitor 201 are provided in the pixel portion, and a driver circuit provided in the periphery of the pixel portion is configured based on a CMOS circuit.

The capacitor line is provided in a direction parallel to the signal line and functions as an upper electrode of the first storage capacitor 200 or a lower electrode of the second storage capacitor 201. The capacitor line is connected to ground or a fixed potential.

From the scanning line driver circuit 802 and the signal line driver circuit 803, the scanning line 107 and the signal line 109 extend to the pixel portion and are connected to the pixel TFT 800, respectively. A flexible printed circuit (FPC) 804 is connected to an external input terminal 805 and used to input an image signal or the like. The FPC 804 is firmly bonded with a reinforcing resin. Connection wirings 806 and 807 are connected to the respective drive circuits. Also,
Although not shown, the counter substrate 808 is provided with a light shielding film and a transparent electrode.

  This embodiment can be combined with the second embodiment.

CMOS circuits and pixel matrix circuits formed by implementing the present invention are applied to electronic devices using various electro-optical devices (active matrix liquid crystal display, active matrix EL display, active matrix EC display) as a display unit. can do.

Such electronic devices include video cameras, digital cameras, projectors (rear type or front type), head mounted displays (goggles type displays), car navigation systems, personal computers, personal digital assistants (mobile computers, mobile phones or electronic books). Etc.). Examples of these are shown in FIGS.

FIG. 7A illustrates a personal computer, which includes a main body 2001, an image input portion 2002, a display portion 2003, and a keyboard 2004. The present invention can be applied to the image input unit 2002, the display unit 2003, and other signal control circuits.

FIG. 7B illustrates a video camera, which includes a main body 2101, a display portion 2102, and an audio input portion 210.
3, an operation switch 2104, a battery 2105, and an image receiving unit 2106. The present invention can be applied to the display portion 2102, the voice input portion 2103, and other signal control circuits.

FIG. 7C shows a mobile computer (mobile computer).
The camera unit 2202, the image receiving unit 2203, operation switches 2204, and a display unit 2205 are included. The present invention can be applied to the display portion 2205 and other signal control circuits.

FIG. 7D illustrates a goggle type display which includes a main body 2301, a display portion 2302, and an arm portion 2303. The present invention can be applied to the display portion 2302 and other signal control circuits.

FIG. 7E shows a player using a recording medium (hereinafter referred to as a recording medium) on which a program is recorded. The main body 2401, the display portion 2402, the speaker portion 2403, the recording medium 2404,
The operation switch 2405 is configured. This apparatus uses a DVD (Digit as a recording medium).
Using ial Versatile Disc), CD, etc., music appreciation, movie appreciation, games and the Internet can be performed. The present invention can be applied to the display portion 2402 and other signal control circuits.

FIG. 7F illustrates a digital camera, which includes a main body 2501, a display portion 2502, and an eyepiece portion 2503.
And an operation switch 2504 and an image receiving unit (not shown). Display unit 250 of the present invention
2 and other signal control circuits.

FIG. 8A illustrates a front type projector, which includes a projection device 2601 and a screen 260.
It consists of two. The present invention can be applied to a projection apparatus and other signal control circuits.

FIG. 8B shows a rear projector, which includes a main body 2701, a projection device 2702, a mirror 2703, and a screen 2704. The present invention can be applied to a liquid crystal display device and other signal control circuits provided in the projection apparatus.

8C shows the projection devices 2601 and 270 in FIGS. 8A and 8B.
It is the figure which showed an example of the structure of 2. Projection devices 2601 and 2702 are light source optical systems 2801.
, Mirrors 2802, 2804 to 2806, dichroic mirror 2803, prism 28
07, a liquid crystal display device 2808, a phase difference plate 2809, and a projection optical system 2810. Projection optical system 2810 includes an optical system including a projection lens. Although the present embodiment shows a three-plate type example, it is not particularly limited, and for example, a single-plate type may be used. In addition, the practitioner may appropriately provide an optical system such as an optical lens, a film having a polarization function, a film for adjusting a phase difference, or an IR film in the optical path indicated by an arrow in FIG. Good.

FIG. 8D shows an example of the structure of the light source optical system 2801 in FIG. In this embodiment, the light source optical system 2801 includes a reflector 2811 and a light source 2812.
, 2813, 2814, a polarization conversion element 2815, and a condenser lens 2816. Note that the light source optical system illustrated in FIG. 8D is an example and is not particularly limited. For example, the practitioner may appropriately provide an optical system such as an optical lens, a film having a polarization function, a film for adjusting a phase difference, or an IR film in the light source optical system.

As described above, the application range of the present invention is extremely wide and can be applied to electronic devices in various fields. Moreover, the electronic device of a present Example is realizable even if it uses the structure which consists of what combination of Examples 1-3.

Claims (1)

A semiconductor layer;
A first insulating film on the semiconductor layer;
An island-shaped electrode on the first insulating film;
A signal line on the first insulating film;
A second insulating film on the island-shaped electrode and on the signal line;
A light shielding film on the second insulating film;
A third insulating film on the second insulating film;
A pixel electrode on the third insulating film;
The semiconductor layer is
A source area,
A drain region;
A channel formation region between the source region and the drain region,
The light shielding film has a resin,
The first insulating film has a first contact hole;
The first insulating film has a second contact hole;
The second insulating film has a third contact hole;
The third insulating film has a fourth contact hole;
The island-shaped electrode is electrically connected to one of the source region or the drain region through the first contact hole,
The signal line is electrically connected to the other of the source region or the drain region through the second contact hole,
The pixel electrode has a region in contact with the island-shaped electrode through the third contact hole and the fourth contact hole,
The third contact hole is arranged to be shifted from the first contact hole;
The fourth contact hole is arranged to be shifted from the first contact hole;
The third contact hole is larger than the first contact hole,
The fourth contact hole is larger than the first contact hole,
The display device having the pixel electrode and an alignment film on the pixel electrode in the fourth contact hole.

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