JP3871736B2 - Liquid crystal display device, photographing device, and information processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention disclosed in this specification relates to a structure of an active matrix liquid crystal display device in which peripheral drive circuits are integrated.
[0002]
Conventionally, an active matrix type liquid crystal display device is known. This has a configuration in which an active matrix circuit and a peripheral drive circuit for driving the circuit are integrated on a glass substrate or a quartz substrate.
[0003]
In such a configuration, a contrivance is made to minimize the area of a portion unnecessary for screen display. For example, an effort is made to minimize the area occupied by the peripheral drive circuit.
[0004]
On the other hand, in a liquid crystal display device, a sealing material for confining liquid crystal, which is called a sealing material, is disposed in a peripheral portion in order to hold liquid crystal between a pair of substrates.
[0005]
As one of the ideas for minimizing the area of the portion unnecessary for the screen display, it is also required to reduce the area occupied by the sealing material.
[0006]
[Problems to be solved by the invention]
In an active matrix liquid crystal display device in which peripheral drive circuits are integrated, defects occurring in the peripheral drive circuits become a problem.
[0007]
In particular, in the configuration in which a seal material is disposed on the peripheral drive circuit and the area other than the pixel (this is called a frame) is minimized, the occurrence of defects in the peripheral drive circuit increases.
[0008]
This problem occurs for the following reasons. That is, the sealing material contains a kind of spacer called a filler for maintaining the substrate interval.
[0009]
In general, the peripheral drive circuit has a very high degree of integration. In such a situation, pressure from the filler (this pressure is estimated to be extremely high locally) is applied to the thin film transistors and wiring in the peripheral drive circuit that will be directly under the filler, causing disconnection and contact. Defects are likely to occur.
[0010]
On the other hand, a spherical substrate spacing holding unit called a spacer is also used in the active matrix region. However, since the active matrix region has a low degree of integration, the occurrence of defects due to the presence of the spacer is not as problematic as the peripheral drive circuit.
[0011]
An object of the invention disclosed in this specification is to provide a configuration in which an area other than a region of a pixel matrix circuit is reduced as much as possible in an active matrix liquid crystal display device incorporating a peripheral driving circuit.
[0012]
On the premise of the above configuration, an object is to provide a configuration in which the peripheral drive circuit is not destroyed by the pressure received from the sealing material.
[0013]
[Means for Solving the Problems]
One of the inventions disclosed in this specification is:
An active matrix liquid crystal display device integrated with a peripheral drive circuit,
A sealing material is arranged on the peripheral drive circuit,
A resin layer is disposed between the peripheral drive circuit and the sealing material.
[0014]
In the above configuration, the resin layer is preferably formed in multiple layers. This is effective for relieving the pressure received from the spacer in the sealing material.
[0015]
In addition, it is effective to form an auxiliary capacitor in the active matrix region using the resin layer. By doing in this way, it can obtain with the value which requires the capacity | capacitance in a pixel.
[0016]
The thickness of the resin layer is preferably half or more of the diameter of the spacer in the sealing material. This is a useful condition for preventing the pressure from reaching the peripheral drive circuit even if the spacer in the sealing material is embedded in the resin layer. When the resin layer is formed in multiple layers, the total thickness may be half or more of the diameter of the spacer in the sealing material.
[0017]
Other aspects of the invention are:
An imaging apparatus including an active matrix liquid crystal display device integrated with a peripheral drive circuit,
A sealing material is disposed on the peripheral drive circuit,
A resin layer is disposed between the peripheral driving circuit and the sealing material.
[0018]
As a specific example of the above structure, a portable video movie provided with an activity matrix type liquid crystal display device can be given.
[0019]
Other aspects of the invention are:
An information processing apparatus including an active matrix liquid crystal display device integrated with a peripheral drive circuit,
A sealing material is disposed on the peripheral drive circuit,
A resin layer is disposed between the peripheral driving circuit and the sealing material.
[0020]
Specific examples of the structure include a portable personal computer and various information terminals each having an active matrix liquid crystal display.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
As one embodiment of the invention disclosed in this specification, as shown in FIG.
An active matrix liquid crystal display device integrated with a peripheral drive circuit,
A sealing material 104 is disposed on the peripheral drive circuit,
A configuration in which resin layers 26 and 301 are disposed between the peripheral drive circuit and the sealing material can be given.
[0022]
In the above configuration, the spacer 103 included in the sealing material 104 can prevent a high pressure from being locally applied to the peripheral drive circuit and destroying the peripheral drive circuit.
[0023]
In addition, by disposing the sealing material on the peripheral drive circuit, a configuration in which the area other than the pixel region is minimized can be realized.
[0024]
【Example】
In the configuration shown in this embodiment, a configuration in which a seal material is disposed on a region where the peripheral drive circuit exists is employed. Further, a configuration is adopted in which a buffer layer made of polyimide is disposed on the peripheral drive circuit in order to prevent the peripheral drive circuit from being damaged by the stress from the spacer contained in the sealing material.
[0025]
FIG. 1 shows a part of a cross section of the active matrix type liquid crystal display device of this embodiment. FIG. 1 shows a configuration called a peripheral drive circuit integrated type having a structure in which a peripheral drive circuit and an active matrix circuit are integrated on the same substrate.
[0026]
In the configuration shown in FIG. 1, a seal portion indicated by 104 is arranged on the peripheral drive circuit. This seal portion has a function of sealing so that the liquid crystal filled in the space 105 (gap between the substrates) does not leak outside.
[0027]
The seal portion 104 is made of a resin material. The seal portion 104 is formed by applying a resin material with a spinner, patterning, and baking. Alternatively, it is formed by a printing method.
[0028]
It is a spacer required to maintain the substrate interval indicated by 103. This spacer is made of a resin material and has a cylindrical shape. In this embodiment, a resin material in which the spacer 103 is mixed in advance is used as the resin material constituting the sealing material 104.
[0029]
Under the sealing material 104, resin layers 26 and 301 are disposed. This resin layer is used as an interlayer insulating film and a dielectric of an auxiliary capacitor in the active matrix region. In the peripheral drive circuit region, this resin layer has a function of relieving the pressure received by the peripheral drive circuit from the spacer in the sealing material.
[0030]
A manufacturing process of the configuration shown in FIG. The manufacturing process described below relates to a structure in which N-channel and P-channel thin film transistors are arranged in the peripheral driver circuit and a P-channel thin film transistor is arranged in the active matrix circuit.
[0031]
In particular, an N-channel thin film transistor has a low-concentration impurity region, and a P-channel thin film transistor has a high-concentration impurity region disposed between a source / drain region and a channel formation region.
[0032]
With such a structure, deterioration of characteristics of the N-channel thin film transistor can be suppressed in the peripheral driver circuit. In the active matrix circuit, a configuration in which the OFF current value is small and the variation in the ON current value is small can be obtained.
[0033]
The manufacturing process is shown in FIG. In FIG. 2, the left side is a manufacturing process of an N-channel type thin film transistor (and its portion) arranged in the peripheral driver circuit. The right side is a manufacturing process of a thin film transistor (and its portion) arranged in the active matrix region.
[0034]
First, as shown in FIG. 2A, a base film (not shown) is formed on the glass substrate 201. A silicon oxide film is used as the base film. This base film functions to prevent diffusion of impurities from the glass substrate 201 and to relieve stress on the glass substrate.
[0035]
Next, an amorphous silicon film (not shown) is formed on the base film to a thickness of 500 mm by plasma CVD. Further, by irradiating with laser light, the amorphous silicon film is crystallized to obtain a crystalline silicon film. As a method for obtaining a crystalline silicon film, heat treatment or strong light irradiation may be used.
[0036]
By patterning this crystalline silicon film, active layers of thin film transistors indicated by 202 and 203 are formed. Here, 202 is an active layer of an N-channel type thin film transistor disposed in the peripheral drive circuit. Reference numeral 203 denotes an active layer of a P-channel thin film transistor disposed in the active matrix circuit.
[0037]
Although only two thin film transistors are shown in the figure, in an actual configuration, tens of thousands to hundreds of thousands (or more) of thin film transistors are integrated.
[0038]
When the active layer is formed, a silicon oxide film is formed as a gate insulating film 204 to a thickness of 1000 mm by plasma CVD. In this way, the state shown in FIG.
[0039]
When the state shown in FIG. 2A is obtained, an aluminum film (not shown) for forming the gate electrode (and the gate wiring) is formed to a thickness of 4000 mm by sputtering. This aluminum film contains 0.1% by weight of scandium.
[0040]
Next, an anodic oxide film having a dense film quality (not shown) is formed to a thickness of 100 mm. This anodic oxidation is performed using an ethylene glycol solution containing 3% tartaric acid as an electrolytic solution. This solution is neutralized with aqueous ammonia.
[0041]
This anodic oxide film has a function of improving the adhesion of a resist mask to be disposed later. In place of the anodic oxide film, a silicon nitride film or a metal film may be used. Alternatively, a method of forming an aluminum oxide film by plasma oxidation in an oxidizing atmosphere may be used.
[0042]
Next, this aluminum film is patterned using resist masks 205 and 206. In this step, an aluminum pattern serving as a base of the gate electrode indicated by 207 and 208 is formed. In this way, the state shown in FIG.
[0043]
When the state shown in FIG. 2B is obtained, anodization using the aluminum patterns 207 and 208 as anodes is performed. In this step, a porous anodic oxide (denoted to be expressed as a film) indicated by 211 and 212 is formed. The growth distance of the anodic oxide is 5000 mm.
[0044]
In this anodic oxidation, an aqueous solution containing 3% oxalic acid is used as the electrolytic solution.
[0045]
In this step, since resist masks 205 and 206 are present, anodic oxidation selectively proceeds on the side surfaces of aluminum patterns 207 and 208. This is because the electrolytic solution does not contact the upper surfaces of the aluminum patterns 207 and 208 because the resist masks 205 and 206 exist. Here, the patterns indicated by 209 and 210 will be gate electrodes later. In this way, the state shown in FIG.
[0046]
Next, the resist masks 205 and 206 are removed. Then, an anodized film having a dense film quality is formed. This anodic oxidation is performed using an ethylene glycol solution containing 3% tartaric acid as an electrolytic solution and neutralized with ammonia water.
[0047]
In this step, the electrolytic solution penetrates into the porous anodic oxide films 211 and 212. Therefore, an anodic oxide film having a dense film quality is formed as indicated by 213 and 214.
[0048]
In this step, gate electrodes 209 and 210 are defined. The surfaces of these gate electrodes are covered with anodic oxide films 213 and 214 having a dense film quality. Further, these gate electrodes and wirings extending from the gate electrodes become the first layer wiring. In this way, the state shown in FIG.
[0049]
Next, P (phosphorus) ions are implanted into the entire surface. In this step, P ions are implanted at a relatively high concentration in order to form source and drain regions. (Figure 2 (E))
[0050]
In this step, P ions are implanted into the regions 215, 217, 218, and 220. Further, P ions are not implanted into the regions 216 and 219.
[0051]
Next, the porous anodic oxides 211 and 212 are removed. Then, the state shown in FIG. In this state, P ions are implanted again. In this step, P ions are implanted with a lower dose than the doping condition shown in FIG.
[0052]
Regions indicated by 221, 222, 223, and 224 are formed as low-concentration impurity regions. Then, a channel forming region 20 of the N channel type thin film transistor is defined. (Fig. 3 (A))
[0053]
Next, a region to be an N-channel thin film transistor is covered with a resist mask 225. In this state, B ions are implanted. This step is performed under the condition that the regions 21 and 25 are the source and drain regions of the P-channel thin film transistor.
[0054]
In this step, the regions indicated by 21 and 25 become the source and drain regions. Further, the regions indicated by 22 and 24 are formed as regions having a P-type property stronger than the regions indicated by 21 and 25.
[0055]
This is because the concentration of P element contained in the regions 22 and 24 is lower than the regions 21 and 25.
[0056]
That is, in the regions 21 and 25, more B element is required to neutralize the P element, and as a result, the regions 22 and 24 develop a stronger P-type.
[0057]
When the impurity ion implantation is completed, the resist mask 225 is removed. Then, laser light irradiation is performed to activate the implanted impurities and anneal the semiconductor film due to ion bombardment.
[0058]
Next, a first interlayer insulating film 226 is formed. Here, a silicon nitride film having a thickness of 4000 mm is formed as the interlayer insulating film 226 by plasma CVD.
[0059]
Then, contact holes are formed, and second-layer wirings (electrodes) 227, 228, 229, and 230 are formed. In this way, the state shown in FIG.
[0060]
Next, a second interlayer insulating film 301 is formed. Here, a resin layer is formed to a thickness of 15000 mm as the second interlayer insulating film 301. The formation method uses a spin coating method.
[0061]
Next, contact holes are formed, and third-layer wirings (electrodes) 231 and 233 are formed. At the same time, a light shielding film 232 for shielding light from the thin film transistors arranged in the active matrix circuit is formed. The light shielding film 232 forms an auxiliary capacitance with the pixel electrode with an interlayer insulating film (resin film) formed later interposed therebetween. In this way, the state shown in FIG.
[0062]
Next, as shown in FIG. 4, a third interlayer insulating film 26 is formed. Here, as the third interlayer insulating film 26, a resin layer having a thickness of 5000 mm is formed by spin coating. Then, contact holes are formed, and pixel electrodes 234 are formed from ITO.
[0063]
In the present embodiment, an auxiliary capacitor is formed by the light shielding film 232 and the pixel electrode existing with the third interlayer insulating film (resin layer) 301 interposed therebetween.
[0064]
Further, a rubbing film 235 is formed. The rubbing film is made of a resin material and is formed by a printing method. In this embodiment, a rubbing film is formed only in the active matrix circuit region. After the rubbing film 235 is formed, a rubbing process is performed.
[0065]
Next, as shown in FIG. 1, a counter substrate 108 is prepared. A counter electrode 107 and a rubbing film 106 are formed on the counter substrate 108. Then, the counter substrate 108 and the substrate shown in FIG. 3 are bonded together to complete the structure shown in FIG.
[0066]
[Example 2]
The invention disclosed in this specification can be used for an active matrix liquid crystal display device in which peripheral drive circuits are integrated.
[0067]
In an active matrix type liquid crystal display device integrated with a peripheral drive circuit, a high degree of integration is required for the peripheral drive circuit. Therefore, it is very useful to use the invention disclosed in this specification.
[0068]
FIG. 5A illustrates a photographing device called a digital still camera, an electronic camera, or a video movie capable of handling moving images.
[0069]
This apparatus has a function of electronically storing an image photographed by a CCD camera (or suitable photographing means) disposed in the camera unit 2002. Then, it has a function of displaying the photographed image on a liquid crystal display device 2003 arranged in the main body 2001. The operation of the apparatus is performed by an operation button 2004.
[0070]
When the invention disclosed in this specification is used, a liquid crystal display device having a high aperture ratio can be obtained, so that high luminance can be obtained.
[0071]
FIG. 5B shows a portable personal computer (information processing apparatus). In this apparatus, a liquid crystal display device 2104 is provided in an openable / closable cover (lid) 2102 attached to a main body 2101, and various information can be input from a keyboard 2103 and various arithmetic operations can be performed.
[0072]
FIG. 5C shows an example in which a flat panel display is used for a car navigation system (information processing apparatus). The car navigation system includes a main body including an antenna unit 2304 and a liquid crystal display device 2302.
[0073]
Switching of various information necessary for navigation is performed by an operation button 2303. In general, the operation is performed by a remote control device (not shown).
[0074]
FIG. 5D illustrates an example of a projection-type image display device. In the figure, the light emitted from the light source 2402 is optically modulated by the liquid crystal display device 2403 and becomes an image. The image is reflected by the mirrors 2404 and 2405 and displayed on the screen 2406.
[0075]
FIG. 5E shows an example in which a display device called a viewfinder is provided in a main body 2501 of a video camera (photographing device).
[0076]
The viewfinder is roughly composed of a liquid crystal display device 2502 and an eyepiece unit 2503 on which an image is displayed.
[0077]
The video camera shown in FIG. 5E is operated by an operation button 2504 and an image is recorded on a magnetic tape stored in a tape holder 2505. An image captured by a camera (not shown) is displayed on the display device 2502. The display device 2502 displays an image recorded on the magnetic tape.
[0078]
Example 3
This embodiment is an example in which a bottom gate type thin film transistor is used in a peripheral drive circuit integrated liquid crystal display device.
[0079]
FIG. 6 shows a cross-sectional view corresponding to FIG. The difference from the structure shown in FIG. 1 in this embodiment is the structure of the thin film transistor. Other configurations are the same as those shown in FIG.
[0080]
【The invention's effect】
By utilizing the invention disclosed in this specification, an active matrix liquid crystal display device having a built-in peripheral driver circuit can have a structure in which an area other than a region of a pixel matrix circuit is reduced as much as possible.
[0081]
In other words, a configuration in which the area other than the pixel region is reduced as much as possible can be obtained by arranging the sealing material on the peripheral drive circuit. In addition, it is possible to obtain a configuration in which the peripheral drive circuit is prevented from being destroyed by the pressure received from the sealing material after having such a configuration.
[Brief description of the drawings]
FIG. 1 is a diagram showing a part of a cross section of an active matrix liquid crystal display device using the invention.
FIG. 2 is a view showing a manufacturing process for obtaining the configuration shown in FIG. 1;
3 is a diagram showing a manufacturing process for obtaining the configuration shown in FIG. 1;
4 is a diagram showing a manufacturing process for obtaining the configuration shown in FIG. 1. FIG.
FIG. 5 is a diagram illustrating examples of various devices using a liquid crystal display device.
FIG. 6 is a diagram showing a part of a cross section of an active matrix liquid crystal display device using the invention.
[Explanation of symbols]
108 counter glass substrate 107 counter electrode 106 rubbing film 105 liquid crystal 104 sealing material 103 spacer 101 spacer 201 glass substrate 202, 203 active layer 204 gate insulating film (silicon oxide film)
205, 206 Resist mask 207, 208 Aluminum pattern 209, 210 Gate electrode pattern 211, 212 Porous anodic oxide 213, 214 Anodized film 215 having a dense film quality Source region (P ion implanted region)
216 P-ion non-implanted region 217 Drain region (P-ion implanted region)
218 P-implanted region 219 P-ion-implanted region 220 P-ion-implanted region 221 P-ion-implanted region (low-concentration impurity region)
20 channel formation region 222 P ion implanted region (low concentration impurity region)
223 P-implanted region (low concentration impurity region)
224 P ion implanted region (low concentration impurity region)
225 Resist mask 21 Source region (B ion-implanted region)
22 Strong P-type region 23 Channel formation region 24 Strong P-type region 25 Drain region ((B ion-implanted region)
226 Interlayer insulating film 227 Source electrode (source wiring)
228 Drain electrode 229 Source electrode (source wiring)
230 Drain electrode 301 Interlayer insulating film 231 Drain electrode (drain wiring)
232 Light shielding film 233 Drain electrode 234 Pixel electrode (ITO electrode)
26 Interlayer insulation film 235 Rubbing film

Claims (18)

A peripheral driving circuit and an active matrix circuit are formed on the first substrate,
A sealing material including a spacer made of a resin material is disposed between the first substrate and the second substrate and above the peripheral drive circuit,
A liquid crystal display device, wherein a resin layer is formed between the peripheral driving circuit and the sealing material. The liquid crystal display device according to claim 1 , wherein the resin layer is a multilayer. 3. The liquid crystal display device according to claim 1 , wherein the resin layer is used for forming an auxiliary capacitor in a region where an active matrix circuit is formed. In any one of claims 1 to 3, the thickness of the resin layer is a liquid crystal display device, characterized in that it has more than half of the thickness of the diameter of the spacer. In any one of claims 1 to 4, wherein the resin layer is a liquid crystal display device characterized by comprising a polyimide. In any one of claims 1 to 5, a liquid crystal display device, wherein the spacer has a cylindrical shape. A peripheral driving circuit and an active matrix circuit are formed on the first substrate,
A sealing material including a spacer made of a resin material is disposed between the first substrate and the second substrate and above the peripheral drive circuit,
A photographing apparatus having a liquid crystal display device, wherein a resin layer is formed between the peripheral driving circuit and the sealing material. 8. The photographing apparatus according to claim 7 , wherein the resin layer is a multilayer. 9. The photographing apparatus according to claim 7 , wherein the resin layer is used for forming an auxiliary capacitor in a region where an active matrix circuit is formed. In any one of claims 7 to 9, the thickness of the resin layer is photographing apparatus characterized in that it has more than half of the thickness of the diameter of the spacer. In any one of claims 7 to 10, imaging apparatus wherein the resin layer is characterized by comprising a polyimide. In any one of claims 7 to 11, imaging apparatus, wherein the spacer has a cylindrical shape. A peripheral driving circuit and an active matrix circuit are formed on the first substrate,
A sealing material including a spacer made of a resin material is disposed between the first substrate and the second substrate and above the peripheral drive circuit,
An information processing apparatus having a liquid crystal display device, wherein a resin layer is formed between the peripheral driving circuit and the sealing material. The information processing apparatus according to claim 13 , wherein the resin layer is a multilayer. 15. The information processing apparatus according to claim 13 , wherein the resin layer is used for forming an auxiliary capacitor in a region where an active matrix circuit is formed. 16. The information processing apparatus according to claim 13 , wherein the resin layer has a thickness that is at least half the diameter of the spacer. In any one of claims 13 to 16, wherein the resin layer is an information processing apparatus characterized by comprising a polyimide. In any one of claims 13 to 17, the information processing apparatus, wherein the spacer has a cylindrical shape.

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