JP2000180884A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device providing reflection electrodes on not only a liquid crystal element part but also its peripheral circuit parts, finishing them up to a flat and mirror surface, having low power consumption, a small chip area and high reliability, minimally suppressing capacity of a video line and having the divided video lines. SOLUTION: In the liquid crystal display device provided with a liquid crystal display part containing a pixel electrode substrate, a substrate opposite to this and a liquid crystal sealed between these substrates, and turning on/off the liquid crystal by a liquid crystal drive voltage applied to a pixel electrode formed in matrix on the surface of the liquid crystal side of the pixel electrode substrate, the video lines 4, 5 are divided, and when the liquid crystal display part is driven, at least the video lines 4, 5 are made more than the number of simultaneous write-in pixels.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device including a pixel electrode substrate, a substrate facing the pixel electrode substrate, and a liquid crystal sealed between the substrates. A liquid crystal display device that turns on / off liquid crystal by a liquid crystal driving voltage applied to pixel electrodes formed in a matrix on the liquid crystal side surface of a pixel electrode substrate,
The present invention relates to a liquid crystal display device in which the number of video lines driven simultaneously when driving the liquid crystal display section is larger than the number of simultaneously written pixels.

[0002]

2. Description of the Related Art Today, the world has entered the multimedia age, and devices for communicating with image information are becoming increasingly important. Above all, liquid crystal display devices have been receiving attention because of their thinness and low power consumption, and have grown into a key industry like semiconductors.

[0003] Liquid crystal display devices are currently mainly used in 10-inch notebook-sized personal computers. In the future, not only personal computers, but also workstations and home televisions, liquid crystal display devices having a larger screen size will be used. However, as the screen size increases, not only the manufacturing apparatus becomes expensive, but also electrically strict characteristics are required to drive a large screen. Therefore, as the screen size increases, the manufacturing cost increases rapidly, for example, in proportion to the second to third power of the size.

Therefore, recently, a projection (projection) system in which a small liquid crystal display panel is manufactured and a liquid crystal image is optically enlarged and displayed has attracted attention. This is because the size can be reduced, the characteristics can be improved, and at the same time, the cost can be reduced, similarly to the scaling rule in which the performance and cost increase with the miniaturization of semiconductors. From these points, when the liquid crystal display panel is a TFT type, a TFT having a small size and sufficient driving force is required.
TFTs also use amorphous Si to polycrystalline Si
And it is shifting to the one using single crystal Si. Video signals of a resolution level such as the NTSC standard used for ordinary television do not require very high-speed processing.

For this reason, not only the TFT but also peripheral drive circuits such as a shift register or a decoder can be made of polycrystalline Si or single-crystal Si to provide a liquid crystal display device in which the display region and the peripheral drive circuit are integrated.

[0006] However, even polycrystalline Si is not as good as single crystal Si, and has a higher resolution level than the NTSC standard.
(Extended Graphics Arra
y), SXGA (Super Extended Gra
phis Array) class display with the same chip size, it becomes difficult to lay out peripheral circuits such as shift registers at a narrow pitch.
It is desired to reduce the circuit scale.

On the other hand, the speed of circuit drive is inevitably increased in the future with higher definition and higher image quality. With this, the delay and dulling of the pulse due to the pulse transmission cause a phenomenon called ghost, and the image quality is severely affected. come.

To solve this problem, a video signal line for transmitting a video signal of the liquid crystal display device may be divided.

In addition, even with these polycrystalline Si, single crystal Si
However, it is possible to provide a reflection type liquid crystal display device in which the drain of a TFT is connected to a reflection electrode, and a liquid crystal is sandwiched between the reflection electrode and the transparent common electrode to form a reflection type liquid crystal element.

When realizing a liquid crystal panel with the same chip size with higher definition and higher image quality, stricter restrictions are imposed on the circuit layout area, and it is essential to increase the speed of circuit driving. Accordingly, pulse delay and dullness become problems. There is also a method of adding a circuit such as a NAND circuit so that the delay and dullness of the pulse do not affect the image quality, but this is not realistic because it increases the circuit scale.

The applicant of the present application has filed Japanese Patent Application No. Hei 7-186473 for a method of manufacturing a reflection type liquid crystal device using the above-mentioned polycrystalline Si and single-crystal Si as a semiconductor substrate.

This application includes the following objects, solutions, and embodiments.

An object of the present invention is to solve the above-mentioned problems, eliminate irregularities on the surface of a pixel electrode, prevent poor alignment and irregular reflection caused by the irregularities, and provide a liquid crystal display device for performing high-quality display and a method of manufacturing the same. To provide.

The reason is that when light is incident on a pixel electrode of a conventional liquid crystal pixel, the incident light is scattered in all directions due to surface irregularities, and the light reflection efficiency becomes very small.
The surface irregularities cause poor alignment in the alignment film rubbing step of the liquid crystal mounting step, resulting in poor alignment of the liquid crystal, lowering the contrast, deteriorating the image quality of the displayed image, and forming grooves between the pixel electrodes. Is not rubbed, which causes poor alignment of the liquid crystal, and at the same time, generates a horizontal electric field between the pixel electrodes in combination with the surface unevenness, thereby causing a bright line. This is because the generation of the bright line remarkably deteriorates the contrast of the displayed image and lowers the image quality.

As a means for solving the problem, the liquid crystal display device of the above application is an active matrix type liquid crystal in which a switching transistor is provided for each pixel, and an active matrix type liquid crystal in which a liquid crystal is sandwiched between a counter electrode substrate. In the display device, all pixel electrode surfaces are located on the same plane and parallel to the active matrix substrate, and at least a part of a side wall of each pixel electrode is in contact with an insulator. The present application relates to chemical mechanical polishing (Chemical Mechanical Poli).
(hereinafter referred to as "CMP"), the surface of the pixel electrode is formed by polishing, so that the surface of the pixel electrode is formed into a mirror-like surface and at the same time, the surfaces of all the pixel electrodes are formed on the same plane. be able to. further,
A pixel electrode layer is formed on the insulating layer, or an insulating layer is formed on the pixel electrode layer on which holes are formed, and the above-described polishing process is performed, so that the gap between the pixel electrodes is satisfactorily filled with the insulating layer. , The unevenness completely disappears. Therefore, irregular reflection and poor orientation caused by the irregularities are prevented, and high-quality image display is possible.

Referring to FIGS. 28 and 29, the embodiment disclosed in the above application will be further described. As a first embodiment, a reflection type liquid crystal display device will be described. FIGS. 28 and 29 show a manufacturing process of the active matrix substrate and cross-sectional views of the liquid crystal element. Hereinafter, the present embodiment will be described in detail step by step. Although a pixel portion is shown in FIGS. 28 and 29, a peripheral driver circuit such as a shift register for driving a switching transistor of the pixel portion can be formed over the same substrate at the same time as the pixel portion forming step. .

An n-type silicon semiconductor substrate 201 having an impurity concentration of 10 ¹⁵ cm ⁻³ or less is partially thermally oxidized to form a LOCOS
Then, boron is ion-implanted with a dose of about 10 ¹² cm ⁻² using the LOCOS 202 as a mask, and a p-type impurity region PWL2 with an impurity concentration of about 10 ¹⁵ cm ⁻³ is formed.
03 is formed. This substrate 201 is thermally oxidized again to form a gate oxide film 20 having an oxide film thickness of 1000 Å or less.
4 is formed (FIG. 28A).

Next, after forming a gate electrode 205 made of n-type polysilicon doped with about 10 ²⁰ cm ⁻³ of phosphorus, phosphorus is ion-implanted into the entire surface of the substrate 201 at a dose of about 10 12 cm ⁻² and an impurity concentration of 10 16 cm −2. An NLD 206 which is an n-type impurity region of about 3 is formed, and subsequently, using a patterned photoresist as a mask, phosphorus is ion-implanted at a dose of about 10 15 cm -2 and an impurity concentration of 1
Source and drain regions 207, 20 of about
7 'is formed (FIG. 28B).

A PSG 20 as an interlayer film is formed on the entire surface of the substrate 201.
8 was formed. This PSG 208 is an NSG (Nondo
pe Silicate Glass) / BPSG (B
oro-Phospho Silicate Glass
s) and TEOS (Tetraetoxy-Silan)
It is also possible to substitute in e). A contact hole is patterned in the PSG 208 immediately above the source and drain regions 207 and 207 ', Al is deposited by sputtering, and then patterned to form an Al electrode 209 (FIG. 25C). In order to improve the ohmic contact characteristics between the Al electrode 209 and the source / drain regions 207 and 207 ', a barrier metal such as Ti / TiN is used to form the Al electrode 209 and the source / drain regions 207 and 207'.
207 '.

A plasma SiN 210 is formed on the entire surface of the substrate 201 at about 3000 Å, and a PSG 211 is formed at about 10,000 Å (FIG. 28).
(D)).

Using the plasma SiN 210 as a dry etching stopper layer, the PSG 211 is patterned so as to leave only the separation region between the pixels, and then the through hole 212 is patterned by dry etching immediately above the Al electrode 209 in contact with the drain region 207 '. (FIG. 28E).

The sputtering or E
The pixel electrode 213 is formed into a film of 10,000 angstroms or more by B (Electron Beam, electron beam) deposition (FIG. 29F). As the pixel electrode 213, a metal film of Al, Ti, Ta, W, or the like, or a compound film of these metals is used.

The surface of the pixel electrode 213 is polished by CMP (FIG. 29 (g)). Polishing amount is PSG211 thickness 10
2,000 angstrom and the thickness of the pixel electrode x angstrom, x angstrom or more, x + 100
Less than 00 angstroms.

The active matrix substrate formed by the above-described process is further provided with an alignment film 215 on the surface thereof, subjected to an alignment process such as a rubbing process on the surface, and bonded to a counter substrate via a spacer (not shown). A liquid crystal 214 is injected into the gap to form a liquid crystal element (FIG. 29).
(H)). In this embodiment, the opposing substrate is the transparent substrate 22.
0, color filter 221 and black matrix 2
22, a common electrode 223 made of ITO or the like, and an alignment film 2
15 '.

Hereinafter, a method of driving the reflection type liquid crystal element of this embodiment will be briefly described. A source region 207 is formed by a peripheral circuit such as a shift register formed on a chip on the substrate 201.
At the same time, a gate potential is applied to the gate electrode 205 to turn on the switching transistor of the pixel and supply a signal charge to the drain region 207 '. The signal charge is applied to the drain region 207 'and the PWL20.
3 is accumulated in a depletion layer capacitance of a pn junction formed between the pixel electrode 213 and the pixel electrode 213 and applies a potential to the pixel electrode 213 via the Al electrode 209. When the potential of the pixel electrode 213 reaches a desired potential, the potential applied to the gate electrode 205 is turned off, and the pixel switching transistor is turned off. Since the signal charge is stored in the pn junction capacitance section, the pixel electrode 213
Is fixed until the pixel switching transistor is driven next time. The fixed potential of the pixel electrode 213 drives the liquid crystal 214 sealed between the substrate 201 and the counter substrate 220 shown in FIG.

The active matrix substrate of this embodiment is shown in FIG.
9 (h), since the surface of the pixel electrode 213 is smooth and the insulating layer is embedded in the gap between the adjacent pixel electrodes, the alignment film 215 formed thereon is formed.
The surface is smooth and has no irregularities. Therefore, the light utilization efficiency is reduced due to scattering of the incident light, which has conventionally been caused by the unevenness,
The reduction in contrast due to rubbing failure and the generation of bright lines due to a lateral electric field due to a step between pixel electrodes are prevented, and the quality of a displayed image is improved.

[0027]

However, in the reflection type display device of the above-mentioned application, the reflectivity of the surface of the reflection electrode, which is simply formed by a film forming device, is not sufficiently high. Due to the alignment characteristics of the liquid crystal and non-uniformity with the liquid crystal, unevenness may occur in the image. Further, there is a problem of image unevenness due to a difference in height between the seal portion and the display area.

In particular, when a plurality of chips of a liquid crystal device including a plurality of liquid crystal elements and their peripheral circuits are to be manufactured at the same time at the silicon wafer stage, a square chip is formed from a wafer having a circular cross section. In this case, a margin remains in the peripheral portion of the wafer, and that portion also has a step,
It is difficult to obtain a liquid crystal device chip of sufficient quality in consideration of the difference in surface materials and the like.

In view of the above, the present invention provides a reflective electrode not only for the liquid crystal element portion but also for the peripheral circuit portion thereof, and finishes the flat and mirror surface. It is an object of the present invention to provide a liquid crystal projector device having low power consumption, small chip area, high reliability, minimizing the capacity of video lines, and having divided video lines. .

[0030]

According to the present invention, there is provided a liquid crystal display comprising a semiconductor substrate, a substrate opposed thereto, and a liquid crystal sealed between the substrates. A matrix substrate for turning on / off the liquid crystal by a liquid crystal drive voltage applied to pixel electrodes formed in a matrix on the liquid crystal side surface of the semiconductor substrate, and simultaneously writing the number of video lines. More than the number of pixels.

Also, the liquid crystal display device of the present invention has a liquid crystal display section including a pixel electrode substrate, a substrate facing the pixel electrode, and a liquid crystal sealed between these substrates. A liquid crystal display device for turning on / off a liquid crystal by a liquid crystal driving voltage applied to pixel electrodes formed in a matrix on a liquid crystal side surface, wherein the number of video lines is larger than the number of simultaneously written pixels.

That is, in the present invention, a pixel electrode in the display area and an electrode in the same layer are provided in the periphery of the display area,
The video signal lines in the peripheral area are divided.

[0033]

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

[First Embodiment] A first embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is an example of a circuit diagram near an image display unit of a liquid crystal panel used in the liquid crystal projector device according to the present embodiment. A method for driving the liquid crystal panel will be described.

In the figure, reference numerals 1 and 2 denote horizontal shift registers, 3 denotes a vertical shift register, 4 and 5 denote video signal video lines, and 6 to 15 sample video signals in accordance with scanning pulses from the horizontal shift register. MOS transistors 16 to 25 are signal lines to which video signals are supplied, 26 is a switching MOS transistor for a TFT in a pixel portion, 27 is a liquid crystal sandwiched between a pixel electrode and a common electrode, and 28 is a pixel electrode This is the additional capacity.

In this circuit, an input video signal is sampled by sampling MOS transistors 6 to 15 and by vertical scanning control signals 29 to 38 of a horizontal shift register. At this time, when the horizontal scanning control signal 39 of the vertical shift register is in the output state, the pixel switching MOS transistor 26 is turned on, and the sampled signal line potential is written to the pixel. Detailed timing will be described with reference to FIG. The number of pixels of the liquid crystal panel will be described with reference to the timing of a 1024 × 768 XGA panel.

First, the drive line 39 for the horizontal scanning output of the vertical shift register 3 is at the high level (H), that is, the pixel transistor 26 is turned on.
The outputs of the horizontal shift registers represented by .about.38 sequentially become high level (H), the sampling MOS transistors 6 to 15 are turned on, pass through the signal lines, and the potentials of the video lines 4 and 5 are written to the pixels. The potential is held by the additional capacitor 28. In this circuit, the outputs from the horizontal shift registers 1 and 2 are 1024 steps. When the 1024th step is completed, the drive line 39 of the vertical shift register 3 is turned off. Next, the drive line 40 from the vertical shift register 3 goes high, and the output lines 29 to 38 of the horizontal shift registers 1 and 2 again go high sequentially (H), and this is repeated.

When the writing of one field is completed, the signal lines 16 to 25 are reset to the common electrode potential. Details will be described with reference to FIG. V1, V2... V768 are shown in FIG.
Of the vertical shift register 3 of FIG. When the output of the vertical shift register 3 is output for one field, a reset pulse is input, and the signal line is reset to the common electrode potential. In this manner, the liquid crystal is driven to be inverted while resetting the signal lines 16 to 25 to the counter electrode potential.

FIG. 4 shows the relationship between the pulses of the gate of the sampling MOS transistor (output of the horizontal shift register) connected to one video line. Hn, Hn + 1, H
n + 2 is the output pulse of the horizontal shift register, ta, tb
Is a waveform dulling time, that is, a time when two signal lines are simultaneously open.

Consider in conjunction with FIG. Gate line 41
7 is turned on, and pixel electrodes 410 and 41 of a certain m line
It charges in order with 1,412. When the gate line 417 is turned off and the gate line 421 is turned on to charge the next (m + 1) line, there is a time when Hn and Hn + 1 are simultaneously open.

Since the pixel electrode 413 connected to the signal line 418 is charged and Hn + 1 is turned on before Hn is turned off, the charge charged on the signal line 419 when the m-th pixel electrode is charged is replaced by the sampling MOS 402 and the video line. 41
6. The potential of the signal line 418 fluctuates through the sampling MOS 401. Then, as a result, the pixel electrode 4
13 will be affected. Therefore, the above problem can be solved by dividing the video line 516 as shown in FIG. In FIG. 6, Hn and Hn + 1, Hn + 1
And Hn + 2 are overlapped in consideration of the case where they overlap,
Needless to say, this is not a limitation.

In FIGS. 1, 5, and 6, the sampling MOS transistor and the switching MO of the pixel portion are shown.
Although the S transistor is illustrated as a single MOS transistor, it is not particularly limited, and it is needless to say that a transfer gate of a CMOS transistor may be used.

Thus, an effect is obtained that a high-definition, high-contrast liquid crystal display device can be produced at low cost and with high reliability.

[Second Embodiment] A second embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is an example of a circuit diagram near an image display unit of a liquid crystal panel used in the liquid crystal projector device according to the present embodiment. A method for driving the liquid crystal panel will be described. In the figure, reference numerals 1 and 2 denote horizontal shift registers, 3 denotes a vertical shift register, 4 and 5 denote video signal video lines, and 6 to 15 denote samplings for sampling a video signal in accordance with a scanning pulse from the horizontal shift register. MOS transistor, 16-2
5 is a signal line to which a video signal is supplied, and 26 is a T of the pixel portion.
The switching MOS transistor for FT, 27 is a liquid crystal sandwiched between the pixel electrode and the common electrode, and 28 is an additional capacitor attached to the pixel electrode.

In this circuit, an input video signal is sampled by sampling MOS transistors 6 to 15 and by vertical scanning control signals 29 to 38 of a horizontal shift register. At this time, when the horizontal scanning control signal 39 of the vertical shift register is in the output state, the pixel switching MOS transistor 26 is turned on, and the sampled signal line potential is written to the pixel. Detailed timing will be described with reference to FIG. The number of pixels of the liquid crystal panel will be described with reference to the timing of a 1024 × 768 XGA panel.

First, the driving line 39 for the horizontal scanning output of the vertical shift register 3 is at a high level (H), that is, the pixel transistor 26 is turned on.
The outputs of the horizontal shift registers represented by .about.38 sequentially become high level (H), the sampling MOS transistors 6 to 15 are turned on, pass through the signal lines, and the potentials of the video lines 4 and 5 are written to the pixels. The potential is held by the additional capacitor 28. In this circuit, the outputs from the horizontal shift registers 1 and 2 are 1024 steps. When the 1024th step is completed, the drive line 39 of the vertical shift register 3 is turned off. Next, the drive line 40 from the vertical shift register 3 goes high, and the output lines 29 to 38 of the horizontal shift registers 1 and 2 again go high sequentially (H), and this is repeated.

When the writing of one line is completed, the signal lines 16 to 25 are reset to the common electrode potential. Figure 3 for details
This will be described with reference to FIG. V768 are the outputs of the vertical shift register 3 in FIG. When the output of the vertical shift register 3 is output for one line, a reset pulse is input, and the signal line is reset to the common electrode potential. In this manner, the liquid crystal is driven to be inverted while resetting the signal lines 16 to 25 to the counter electrode potential.

FIG. 4 shows the relationship between the pulses of the gate of the sampling MOS transistor (the output of the horizontal shift register) connected to one video line. Hn, Hn + 1, H
n + 2 is the output pulse of the horizontal shift register, ta, tb
Is a waveform dulling time, that is, a time when two signal lines are simultaneously open.

Consider in conjunction with FIG. Gate line 41
7 is turned on, and pixel electrodes 410 and 41 of a certain m line
It charges in order with 1,412. When the gate line 417 is turned off and the gate line 421 is turned on to charge the next (m + 1) line, there is a time when Hn and Hn + 1 are simultaneously open.

Since the pixel electrode 413 connected to the signal line 418 is charged and Hn + 1 is turned on before Hn is turned off, the charge charged on the signal line 419 when the m-th pixel electrode is charged is replaced by the sampling MOS 402 and the video line. 41
6. The potential of the signal line 418 fluctuates through the sampling MOS 401. Then, as a result, the pixel electrode 4
13 will be affected. Therefore, the above problem can be solved by dividing the video line 516 as shown in FIG. In FIG. 6, Hn and Hn + 1, Hn + 1
And Hn + 2 are overlapped in consideration of the case where they overlap,
Needless to say, this is not a limitation.

In FIGS. 1, 5, and 6, the sampling MOS transistor and the switching MO of the pixel portion are shown.
Although the S transistor is illustrated as a single MOS transistor, it is not particularly limited, and it is needless to say that a transfer gate of a CMOS transistor may be used. Although the timing of XGA has been described with reference to FIGS. 2 and 7, the present invention is not particularly limited to this, and it goes without saying that higher definition such as SXGA may be used.

Therefore, an effect is obtained that a high-definition, high-contrast liquid crystal display device can be produced at low cost and with high reliability. [Third Embodiment] A liquid crystal display device having divided video lines in the above liquid crystal panel will be described. Hereinafter, embodiments of the present invention will be described with reference to a plurality of liquid crystal panels, but the present invention is not limited to each embodiment. It goes without saying that the effect is increased by combining the mutual forms of technology. Although the structure of the liquid crystal panel is described using a semiconductor substrate, the structure is not limited to the semiconductor substrate, and the structure described below may be formed on a normal transparent substrate. . The liquid crystal panels described below are all of a MOSFET type or a TFT type, but may be of a two-terminal type such as a diode type. In addition, the liquid crystal panel described below can be used as a display device for home televisions, projectors, head mounted displays, 3D video game machines, laptop computers, electronic organizers, video conferencing systems, car navigation systems, airplane panels, etc. It is valid.

FIG. 8 is a sectional view of the liquid crystal panel of the present invention. In the figure, reference numeral 301 denotes a semiconductor substrate;
2 ′ are p-type and n-type wells, 303 and 30 respectively
3 'and 303 "are source regions of the transistor, 304 is a gate region, and 305, 305' and 305" are drain regions.

In FIG. 8, reference numeral 306 denotes a field oxide film; 310, a source electrode connected to a data wiring;
11 is a drain electrode connected to the pixel electrode, 312 is a pixel electrode also serving as a reflecting mirror, 307 is a light shielding layer covering a display area and a peripheral area, and is suitably made of Ti, TiN, W, Mo or the like.
As shown in FIG. 8, the light-shielding layer 307 is covered in the display area except for a connection portion between the pixel electrode 312 and the drain electrode 311, but in the peripheral pixel area, a part of the video line, the clock line, and the like is provided. In the region where the wiring capacitance is heavy, the light-shielding layer 307 is excluded, and in the portion where the light-shielding layer 307 is exposed to high-speed signals, illumination light is mixed in. The device is designed so that it can be transferred. 308 is a light shielding layer 30
7, a flattening process is performed on the P-SiO layer 318 by SOG on the P-SiO layer 318, and the P-SiO layer 318 is further covered with the P-SiO layer 308 to secure the stability of the insulating layer 308. . Besides flattening by SOG, P-TE
OS (Phospho-Tetraetoxy-Sil)
a) After forming a film and further covering the P-SiO layer 318, it is needless to say that the insulating layer 308 may be subjected to a CMP process and flattened.

Reference numeral 309 denotes a reflection electrode 312 and a light shielding layer 3.
07, and serves as a charge storage capacitor of the reflective electrode 312 via the insulating layer 309. In order to form a large capacity, besides SiO ₂ , high dielectric constant PS
A laminated film with iN, Ta ₂ O ₅ , or SiO ₂ is effective. By providing the light-shielding layer 307 on a flat metal such as Ti, TiN, Mo, or W, a film thickness of about 500 to 5000 Å is preferable.

Further, 314 is a liquid crystal material, 315 is a common transparent electrode, 316 is a counter substrate, 317 and 317 'are high concentration impurity regions, 319 is a display region, and 320 is an antireflection film.

As shown in FIG. 8, high-concentration impurity layers 317 and 317 'having the same polarity as the wells 302 and 302' formed below the transistor are formed in the periphery and the contents of the wells 302 and 302 '. Even when a high-amplitude signal is applied to the source, the well potential is fixed at a desired potential in the low-resistance layer, so that stable and high-quality image display can be realized. Further, the high-concentration impurity layers 317 and 317 'are provided between the n-type well 302' and the p-type well 302 with a field oxide film interposed therebetween, and are provided immediately below the field oxide film normally used in a MOS transistor. Channel stop layer is unnecessary.

These high-concentration impurity layers 317, 317 '
Can be performed simultaneously in the source and drain layer formation process, so the number of masks and man-hours in the fabrication process are reduced,
Cost reduction was achieved.

Next, reference numeral 313 denotes an antireflection film provided between the common transparent electrode 315 and the counter substrate 316 so as to reduce the interface reflectance in consideration of the refractive index of the liquid crystal at the interface. Is done. In that case, an insulating film smaller than the refractive index of the counter substrate 316 and the transmission electrode 315 is preferable.

Next, a plan view of the present invention is shown in FIG. In the figure, 321 is a horizontal shift register, 322 is a vertical shift register, 323 is an n-channel MOSFET,
24 is a p-channel MOSFET, 325 is a storage capacitor,
326 is a liquid crystal layer, 327 is a signal transfer switch, 328 is a reset switch, 329 is a reset pulse input terminal,
330 is a reset power supply terminal, and 331 is a video signal input terminal. The semiconductor substrate 301 is p-type in FIG. 8, but may be n-type.

The well region 302 ′ is
And the opposite conductivity type. Therefore, in FIG. 6, the well region 302 is p-type. p-type well region 302
It is preferable that impurities are implanted into the n-type well region 302 ′ at a higher concentration than the semiconductor substrate 301.
The impurity concentration of the semiconductor substrate 301 is 10 ¹⁴ to 10 ¹⁵ (cm
^{In the case of -3} ), the impurity concentration of the well region 302 is 10 ¹⁵ to
10 ¹⁷ (cm ⁻³ ) is desirable.

The source electrode 310 is connected to a data line to which a display signal is sent, and the drain electrode 311 is connected to the pixel electrode 3.
12 is connected. These electrodes 310 and 311 usually have Al, AlSi, AlSiCu, AlGeCu, Al
Cu wiring is used. If a via metal layer made of Ti or TiN is used for the contact surface between the lower part of these electrodes 310 and 311 and the semiconductor, the contact can be stably realized. Also, the contact resistance can be reduced. The pixel electrode 312 has a flat surface and is desirably a high-reflection material. Al, AlSi, AlSiCu, AlGeCu, A
It is possible to use materials such as Cr, Au, and Ag other than 1C. Further, in order to improve flatness, the surfaces of the base insulating layer 309 and the pixel electrode 312 are treated by a chemical mechanical polishing (CMP) method.

The storage capacitor 325 shown in FIG.
This is a capacitor for holding a signal between the common electrode 12 and the common transparent electrode 315. A substrate potential is applied to the well region 302. In this embodiment, the transmission gate configuration of each row is such that the first row from the top is an n-channel MOSFET
At 323, the order is changed between adjacent rows so that the lower row is the p-channel MOSFET 324 and the lower row is the p-channel MOSFET 324 and the lower row is the n-channel MOSFET 323. As described above, not only the power supply line is brought into contact with the periphery of the display area in the stripe well, but also a thin power supply line is provided in the display area to make contact.

At this time, the stabilization of the well resistance is key. Therefore, in the case of a p-type substrate, a configuration is adopted in which the contact area or the number of contacts inside the display region of the n-well is increased compared to the contact of the p-well. Since the p-well has a constant potential in the p-type substrate, the substrate plays a role as a low-resistance body. Therefore, the influence of the swing due to the input and output of the signal to the source and drain of the n-well having the island shape tends to be large, but this can be prevented by increasing the contact from the upper wiring layer. As a result, stable and high-quality display can be realized.

A video signal (a video signal, a pulse-modulated digital signal, or the like) is input from a video signal input terminal 331, and opens and closes a signal transfer switch 327 in response to a pulse from the horizontal shift register 321 to connect to each data wiring. Output. From the vertical shift register 322, a high pulse is applied to the gate of the n-channel MOSFET 323 and a low pulse is applied to the gate of the p-channel MOSFET in the selected row.

As described above, the switch in the pixel portion is constituted by a single-crystal CMOS transmission gate, and the signal to be written to the pixel electrode has the advantage that the source signal can be fully written without depending on the threshold value of the MOSFET. Have.

Further, since the switch is composed of a single crystal transistor, there is no unstable behavior at the crystal grain boundary of the polySi-TFT, and a highly reliable high-speed driving without variation can be realized.

Next, the configuration of the panel peripheral circuit will be described with reference to FIG.
Explanation will be made using 0. In FIG. 10, 337 is a display area of a liquid crystal element, 332 is a level shifter circuit, 333 is a video signal sampling switch, 334 is a horizontal shift register, 335 is a video signal input terminal, and 336 is a vertical shift register.

With the above-described configuration, a logic circuit such as a shift register for both H and V is connected to the video signal input terminal 3
Since an amplitude of about 35 to 25 V and 30 V is supplied,
It can be driven at an extremely low value of about 1.5 to 5 V, and high speed and low voltage consumption can be achieved. Here, the horizontal and vertical SR are
The scanning direction can be bi-directionally controlled by a selection switch, so it is possible to respond to changes in the arrangement of optical systems, etc. without changing the panel, and the same panel can be used for different series of products, reducing cost. There are merits that can be achieved. In FIG. 10, the video signal sampling switch is
Although a one-transistor one-transistor configuration has been described, it is needless to say that the input video lines can all be written to signal lines by using a CMOS transmission gate configuration.

Further, when the CMOS transmission gate structure is used, there is a problem that a video signal is swung due to a difference in the area between the NMOS gate and the PMOS gate and the overlap capacitance between the gate and the source / drain. This is the MOSFET of the sampling switch of each polarity
By connecting the source and drain of a MOSFET having a gate amount of about １ ／ of the gate amount to a signal line, and applying a reverse-phase pulse, the swing can be prevented, and an extremely good video signal is written to the signal line. Was. As a result, higher-quality display is possible.

Next, the direction in which the video signal and the sampling pulse are accurately synchronized will be described with reference to FIG. For this purpose, it is necessary to change the delay amount of the sampling pulse. 342 is a pulse delay inverter, 343 is a switch for selecting which delay inverter to select, 344 is an output whose delay amount is controlled, 345 is a capacity (outB is a reverse phase output, o
ut is an in-phase output). 346 is a protection circuit.

From SEL1 (SEL1B) to SEL3 (S
EL3B) can select how many passes through the delay inverter 342.

Since the synchronizing circuit is built in the panel, the delay amount of the pulse from the outside of the panel becomes
In the case of R, G, B three-panel panels, even if the symmetry is lost due to the jig, etc., it can be adjusted with the above selection switch, and the R, G, B
A good display image with no displacement due to the high pulse phase range was obtained. Needless to say, it is also effective to incorporate a temperature measuring diode inside the panel and to correct the temperature by referring to the delay amount from a table based on the output of the diode.

Next, the relationship with the liquid crystal material will be described.
FIG. 8 shows a flat counter substrate structure. However, the common electrode substrate 316 is formed with irregularities in order to prevent interface reflection of the common transparent electrode 315, and the common transparent electrode 315 is formed on the surface thereof.
Is provided. On the opposite side of the common electrode substrate 316, an antireflection film 320 is provided. In order to form these concavities and convexities, a method in which sandblasting is performed using abrasive grains having a small particle size is also effective for increasing the contrast.

As the liquid crystal material, a polymer network liquid crystal PNLC was used. However, PDLC or the like may be used as the polymer network liquid crystal. The polymer network liquid crystal PNLC is produced by a polymerization phase separation method. A solution is prepared from the liquid crystal and a polymerizable monomer or oligomer, and the solution is injected into a cell by a usual method. Then, the liquid crystal and the polymer are phase-separated by UV polymerization to form a polymer in the liquid crystal in a network. PNLC has many liquid crystals (70-9)
0 wt%).

In PNLC, the refractive index anisotropy (Δ
When a nematic liquid crystal having a high n) is used, light scattering is not strong. When a nematic liquid crystal having a large dielectric anisotropy (Δε) is used, driving can be performed at a low voltage. Largeness of the polymer network, that is, the center distance of the mesh is 1 to 1.5
(Μm), the light scattering is strong enough to obtain high contrast.

Next, the relationship between the seal structure and the panel structure will be described with reference to FIG. In FIG.
351 is a seal portion, 352 is an electrode pad, and 353 is a clock buffer circuit. An amplifier unit (not shown) is used as an output amplifier at the time of panel electrical inspection.
In addition, there is an Ag paste portion (not shown) for taking the potential of the counter substrate, 356 is a display portion using a liquid crystal element, and 357 is a peripheral circuit portion such as a horizontal / vertical shift register (SR). A seal portion 351 indicates a contact area of a pressure-sensitive adhesive or an adhesive for bonding a pixel electrode 312 provided on the semiconductor substrate 301 on the four sides of the display portion 356 to a glass substrate provided with the common electrode 315. After bonding at 351, liquid crystal is sealed in the display unit 356 and the shift register unit 357.

As shown in FIG. 12, in the present embodiment, the total chips s inside and outside the seal are provided.
A circuit is provided so that the size is reduced. In the present embodiment, the drawer of the pad is connected to one side of the panel.
However, it is possible to take out not only one side but also many sides on both long sides, which is effective when handling a high-speed clock.

Further, since the panel of the present invention uses a semiconductor substrate such as a Si substrate, strong light is irradiated as in a projector, and when light is applied to the side wall of the substrate, the substrate potential fluctuates. Panel malfunction may occur. Therefore, the side wall of the panel and the peripheral circuit portion of the display area on the top surface of the panel are a substrate holder capable of shielding light, and the back surface of the Si substrate has a high thermal conductivity through an adhesive having a high thermal conductivity. It has a holder structure in which metals such as Cu are connected.

Next, a reflective electrode structure and a method of manufacturing the same, which are the points of the present invention, will be described. The completely flat reflective electrode structure of the present invention is different from the usual method of patterning and polishing a metal, in advance, the groove is etched in advance at the electrode pattern, the metal is formed there, This is a novel method for removing the metal on the region where the electrode pattern is not formed by polishing and flattening the metal on the electrode pattern. Moreover, the width of the wiring is much wider than the region other than the wiring, and the common problem of the conventional etching apparatus causes the following problem, and the structure of the present invention cannot be manufactured.

When etching is performed, a polymer is deposited during the etching, and patterning cannot be performed. Then, the conditions were changed in the oxide film type etching (CF4 / CHF3 type). (FIG. 13) total pressure (conventional)
At 1.7 torr (a), (this time) at 1.0 torr (b).

When the deposition gas CHF 3 is exposed under the conditions shown in FIG.
Although it decreases, the difference in dimensions (loading effect) between the pattern close to the resist and the pattern far from it becomes extremely large, indicating that the pattern cannot be used.

In FIG. 13B, in order to suppress the loading effect, the pressure is gradually reduced, and when the pressure is reduced to 1 torr or less, the loading effect is considerably suppressed, and CH
F3 was set to zero, and it was found that etching using only CF4 was effective.

Further, there is almost no resist in the pixel electrode region, and the peripheral portion is covered with the resist.
It was found that it was difficult to form the structure, and it was found that it was effective to provide a free electrode equivalent to the pixel electrode and its shape up to the periphery of the display area.

With this structure, there is no step between the conventional display portion and the peripheral portion or the seal portion, the gap accuracy is increased, the in-plane uniform pressure is increased, and unevenness during injection is reduced. Thus, an effect that high-quality image quality can be obtained with good yield was obtained.

Next, an optical system incorporating the reflection type liquid crystal panel of the present invention will be described with reference to FIG. FIG.
, 371 is a light source such as a halogen lamp, 372 is a condensing lens for narrowing down the light source image, 373 and 375 are planar convex Fresnel lenses, 374 is a color separation optical element for separating into R, G, and B, and is a dichroic. Mirrors, diffraction gratings, etc. are effective.

A mirror 376 guides the respective lights separated into R, G, and B lights to the R, G, and B panels, and a mirror 377 illuminates the condensed beam to the reflective liquid crystal panel with parallel lights. The field lens 378 has an aperture at the position of the reflective liquid crystal element 379 described above. Reference numeral 380 denotes a projection lens that expands by combining a plurality of lenses.
Reference numeral 1 denotes a screen, which can normally provide a clear, high-contrast, bright image if it is composed of a Fresnel lens that converts projection light into parallel light and a lenticular lens that displays a wide viewing angle vertically and horizontally. .

In the configuration shown in FIG. 14, only one color panel is described.
9 are separated into three colors, and three panel panels are arranged. Further, it is needless to say that not only three plates but also a single plate configuration is possible by providing a microlens array on the surface of the reflective liquid crystal device panel and irradiating different incident lights to different pixel regions. A voltage is applied to the liquid crystal layer of the liquid crystal element, and the light that has been specularly reflected at each pixel is transmitted through the squeezed portion 379 and projected on the screen.

On the other hand, when the voltage is not applied and the liquid crystal layer is a scatterer, the light incident on the reflection type liquid crystal element is scattered isotropically and the angle 379 in which the aperture of the aperture portion is observed is shown. Except for the scattered light inside, there is no need for the projection lens. Thereby, black is displayed. As can be seen from the above optical system, no polarizing plate is required, and the entire surface of the pixel electrode enters the projection lens with a high reflectance of the signal light, so that a display 2-3 times brighter than in the past can be realized. As described in the above embodiment, anti-reflection measures are taken on the surface and the interface of the counter substrate, the noise light component is extremely small, and high contrast display can be realized. In addition, since the panel size can be reduced, all optical elements (lenses, mirrors etc.) are reduced in size, and low cost and light weight are achieved.

The color non-uniformity, luminance non-uniformity, and fluctuation of the light source can be reduced by inserting an integrator (fly-eye lens type rod type) between the light source and the optical system to thereby obtain the color non-uniformity, luminance non-uniformity on the screen. Could be solved.

A peripheral electric circuit other than the liquid crystal panel will be described with reference to FIG. In the figure, reference numeral 385 denotes a power supply, which is mainly divided into a lamp power supply and a system power supply for driving a panel and a signal processing circuit. Reference numeral 386 denotes a plug, and 387 denotes a lamp temperature detector. When there is an abnormality in the lamp temperature, the control board 388 controls the lamp to stop. This is controlled not only by the lamp but also by the 389 filter safety switch. For example, if a high-temperature lamp house box is to be opened, safety measures are taken to prevent the box from burning. Reference numeral 390 denotes a speaker, and 391 denotes an audio board. A processor for 3D sound, surround sound, or the like can be incorporated as required. Reference numeral 392 denotes an expansion board 1, which is an external device 396 for an S terminal for video signals, composite video and audio for video signals, and the like.
, A selection switch 395 for selecting which signal to select, and a tuner 394. A signal is sent to the extension board 2 via the decoder 393. On the other hand, the expansion board 2 mainly has a Dsub15 pin terminal for video from another system or a computer, and receives an A / D signal via a switch 450 for switching to a video signal from the decoder 393.
The signal is converted into a digital signal by the converter 451.

A main board 453 mainly includes a memory such as a video RAM and a CPU. The NTSC signal that has been A / D converted by the A / D converter 451 is temporarily stored in a memory and assigned to a high pixel count.
Signal processing such as interpolation of intermittent signals of empty elements that do not match the number of liquid crystal elements, and signal processing such as gamma conversion edge gradation and brightness adjustment bias adjustment suitable for liquid crystal display elements are performed. If a VGA signal is received instead of an NTSC signal, for example, if a VGA signal is received, the resolution conversion process is also performed for a high-resolution XGA panel. The main board 453 also performs processing such as combining a computer signal with an NTSC signal of a plurality of image data as well as one image data. The output of the main board 453 is subjected to serial / parallel conversion, and is applied to the head board 454 in a form that is less affected by noise. The head board 454 performs D / A conversion after parallel / serial conversion again, divides according to the number of video lines on the panel, and
A signal is written to the liquid crystal panels 455, 456, and 457 of B, G, and R colors. Reference numeral 452 denotes a remote control operation panel, and a computer screen can be easily operated with the same feeling as a TV. Also, the liquid crystal panels 455, 456, 457〃
Have the same liquid crystal device configuration provided with color filters of each color. As described above, since each liquid crystal device processes an image that does not always have high resolution into high-quality image by processing, the display result of the present invention can display an extremely clear image.

[Fourth Embodiment] An example in which a liquid crystal projector device is configured using the liquid crystal display device described in each of the above embodiments will be described as a fourth embodiment. In the optical system of a liquid crystal projector device, if the light source light is not changed, the pixel pit becomes severe,
Further, higher speed driving is required. However, by adopting the above-described configuration of dividing the video line, a new circuit is not inserted, and even if output pulses overlap, the image quality is not affected. It can be produced at low cost and with high reliability.

Here, an optical system of a liquid crystal projector using a higher resolution liquid crystal panel will be described in detail.

FIG. 16 is a configuration diagram of an optical system of a front and rear projection type liquid crystal display device using the liquid crystal display device of the present invention.
FIG. 16A is a top view, FIG. 16B is a front view, and FIG. 16C is a side view. In the figure, reference numeral 1301 denotes a projection lens for projecting onto a screen; 1302, a liquid crystal panel with microlenses;
303 is a polarizing beam splitter (PBS), 1340
Is an R (red light) reflecting dichroic mirror, 1341 is a B / G (blue & green light) reflecting dichroic mirror, 1
342 is a B (blue light) reflecting dichroic mirror, 13
43 is a high reflection mirror that reflects all color light, 1350 is a Fresnel lens, 1351 is a convex lens, 1306 is a rod type integrator, 1307 is an elliptical reflector, 13
08 is an arc lamp such as a metal halide or UHP. Here, R (red light) reflecting dichroic mirror 1
340, a B / G (blue & green light) reflecting dichroic mirror 1341, and a B (blue light) reflecting dichroic mirror 1342 each have a spectral reflection characteristic as shown in FIG.

These dichroic mirrors, together with the high-reflection mirror 1343, are three-dimensionally arranged as shown in the perspective view of FIG. 18, and color-separate white illumination light into R, G, and B as described later. At the same time, each primary color light illuminates the liquid crystal panel 1302 from three-dimensionally different directions.

Here, a description will be given in accordance with the progress of the light beam. First, the light beam emitted from the lamp 1308 of the light source is white light, and is condensed by the elliptical reflector 1307 at the entrance of the integrator 1306 in front of the light beam. As the reflection proceeds, the spatial intensity distribution of the light beam is made uniform. The light beam emitted from the integrator 1306 is the convex lens 1
351 and the Fresnel lens 1350 are converted into parallel light beams in the x-axis direction (reference to the front view in FIG. 16B), and reach the B reflection dichroic mirror 1342 first. The B reflection dichroic mirror 1342 reflects only the B light (blue light), and the R reflection dichroic mirror at a predetermined angle with respect to the z axis in the z-axis direction, that is, on the lower side (reference to the front view in FIG. 16B). Go to 1340. On the other hand, the color light (R / G light) other than the B light is reflected by the B reflection dichroic mirror 134.
2 and at right angles to the z-axis
The light is reflected in the direction (downward), and also goes to the R reflection dichroic mirror 1340. Here, the B reflection dichroic mirror 1342 and the high reflection mirror 1343 are both shown in FIG.
Based on the front view of (a), integrator 1
The light flux (x-axis direction) from 306 is converted into the z-axis direction (lower side)
And a high-reflection mirror 1343
Has a tilt of just 45 ° with respect to the xy plane with the y-axis direction as the rotation axis.

On the other hand, the B-reflection dichroic mirror 1342 is also set at an angle smaller than 45 ° with respect to the xy plane with the y-axis direction as the rotation axis. Accordingly, while the R / G light reflected by the high reflection mirror 1343 is reflected at a right angle in the z-axis direction, the B light reflected by the B reflection dichroic mirror 1342 is reflected at a predetermined angle with respect to the z axis. (Tilt in the x-z plane) goes downward. Here, in order to make the illumination ranges of the B light and the R / G light on the liquid crystal panel 1302 coincide, the principal ray of each color light is the liquid crystal panel 13.
The amount of shift and the amount of tilt of the high-reflection mirror 1343 and the B-reflection dichroic mirror 1342 are selected so as to intersect on the line 02.

Next, as described above, the downward direction (the z-axis direction)
The R / G / B light directed to is directed to the R reflection dichroic mirror 1340 and the B / G reflection dichroic mirror 1341, which are the B reflection dichroic mirror 134.
2 and the lower side of the high reflection mirror 1343,
The G reflection dichroic mirror 1341 is disposed at an angle of 45 ° with respect to the x-z plane with the x axis as the rotation axis, and the R reflection dichroic mirror 1340 is also positioned with respect to the xz plane with the x axis direction as the rotation axis. The angle is set shallower than 45 °. Therefore, of the R / G / B light incident on these, first, the B / G light is converted to the R reflection dichroic mirror 13.
40, the B / G reflecting dichroic mirror 13
41, the light is reflected at right angles in the y-axis + direction,
After being polarized through 03, the liquid crystal panel 1302 arranged horizontally on the xz plane is illuminated.

Among them, the B light is as described above (FIG. 16).
(A) and FIG. 16 (b)), since the light travels at a predetermined angle (tilt in the xz plane) with respect to the x-axis, after reflection by the B / G reflection dichroic mirror 1341, The liquid crystal panel 13 maintains a predetermined angle (tilt in the xy plane) with respect to the liquid crystal panel 13 as an incident angle (in the xy plane direction).
Illuminate 02.

The G light is reflected at right angles by the B / G reflection dichroic mirror 1341, travels in the positive y-axis direction, is polarized through the PBS 1303,
That is, the liquid crystal panel 1302 is illuminated vertically. The R light is reflected in the y-axis + direction by the R reflection dichroic mirror 1340 by the R reflection dichroic mirror 1340 disposed in front of the B / G reflection dichroic mirror 1341 as described above. )
As shown in (side view), a predetermined angle (y
(−z-plane tilt), advance in the y-axis + direction, and
After being polarized through the liquid crystal panel 1302, the liquid crystal panel 1302 is illuminated with an angle with respect to the y-axis as an incident angle (y-z plane direction).

As described above, in order to make the illumination ranges of the RGB color lights on the liquid crystal panel 1302 coincide with each other, the B / B of the respective color lights cross each other on the liquid crystal panel 1302.
The shift amount and the tilt amount of the G reflection dichroic mirror 1341 and the R reflection dichroic mirror 1340 are selected. Further, as shown in FIG. 17A, the cut wavelength of the B reflection dichroic mirror 1341 is 480.
The cut wavelength of the B / G reflection dichroic mirror 1341 is 570 nm, as shown in FIG.
R reflection dichroic mirror 1 as shown in FIG.
Since the cut wavelength of 340 is 600 nm, unnecessary orange light passes through the B / G reflection dichroic mirror 1341 and is discarded. Thereby, an optimal color balance can be obtained.

Then, as described later, the liquid crystal panel 1302
The RGB light is reflected and polarization-modulated by the PBS 1303.
The light flux reflected on the PBS surface 1303a of the PBS 1303 in the + x-axis direction becomes image light, and the projection lens 13
01 is enlarged and projected on a screen (not shown). By the way, each RG that illuminates the liquid crystal panel 1302
Since the B light has a different incident angle, each of the RGB light reflected from the B light has a different emission angle.
As 301, a lens having a lens diameter and an opening large enough to capture all of them is used. However, the inclination of the light beam incident on the projection lens 1301 is made parallel by each color light passing twice through the micro lens, and the inclination of the light incident on the liquid crystal panel 1302 is maintained. However, as shown in FIG. 19, in the transmission type of the conventional example, the light beam emitted from the liquid crystal panel spreads more largely due to the light condensing action of the microlens. Therefore, the projection lens for capturing this light beam is further required. A large numerical aperture was required, resulting in an expensive lens.

However, in this example, since the spread of the light beam from the liquid crystal panel 2 is relatively small in this way, a sufficiently bright projection image can be obtained on a screen even with a projection lens having a smaller numerical aperture, and the cost is lower. It is possible to use a simple projection lens. Further, an example of a stripe type display method in which the same color is arranged in the vertical direction can be used in the present embodiment, but is not preferable in the case of a liquid crystal panel using a microlens, as described later.

Next, the liquid crystal panel 13 of the present invention used here
02 will be described. FIG. 20 shows the liquid crystal panel 1302.
17 (corresponding to the yz plane in FIG. 16).
In the figure, 1321 is a microlens substrate, 1322
Is a micro lens, 1323 is a sheet glass, 1324
Is a transparent counter electrode, 1325 is a liquid crystal layer, 1326 is a pixel electrode, 1327 is an active matrix drive circuit section, 13
28 is a silicon semiconductor substrate. Reference numeral 1252 denotes a peripheral seal portion. Here, in the present embodiment, R, G,
The B pixels are integrated in one panel, and the size of one pixel is reduced. Therefore, it is important to increase the aperture ratio, and the reflective electrode must be present in the range of the condensed light, and the configurations described in the first to third embodiments are important. . The micro lens 1322 is formed on a glass substrate (alkali glass) 1 by a so-called ion exchange method.
321, and has a two-dimensional array structure at a pitch twice the pitch of the pixel electrodes 1326.

The liquid crystal layer 1325 employs a so-called ECB mode nematic liquid crystal such as DAP or HAN adapted to the reflection type, and a predetermined alignment is maintained by an alignment layer (not shown). Since the voltage value is low and the accuracy of the potential of the pixel electrode 1326 becomes more important, the circuit and configuration of the present invention are effective, and the number of pixels on a single plate and the number of video lines are also large. It is effective for Pixel electrode 132
Numeral 6 is made of Al and also serves as a reflecting mirror, and is subjected to a so-called CMP process in the final step after patterning in order to improve the surface properties and improve the reflectance (to be described in detail later).

Active matrix drive circuit 1327
Is a semiconductor circuit provided on a so-called silicon semiconductor substrate 1328, which drives the pixel electrode 1326 in an active matrix manner. A gate line driver (not shown) (not shown) or the like is provided around the circuit matrix. A signal line driver (such as a horizontal register) is provided (details will be described later). The peripheral driver and the active matrix drive circuit are configured to write the RGB primary color video signals to predetermined RGB pixels. Although the pixel electrodes 1326 do not have a color filter, the active matrix drive circuit Are distinguished as respective RGB pixels by a primary color video signal written in the above, and form a predetermined RGB pixel array described later.

Here, looking at the G light illuminating the liquid crystal panel 1302, the G light is P
The liquid crystal panel 13 after being polarized by the BS 1303
02 perpendicularly. An arrow G (in / out) in the drawing shows an example of a ray incident on one micro lens 1322a. As shown in the figure, the G light beam is collected by the micro lens 1322, and illuminates the G pixel electrode 1326g. Then, the light is reflected by the pixel electrode 1326g made of Al, and is emitted to the outside of the panel again through the same micro lens 1322a. When the G light (polarized light) reciprocates through the liquid crystal layer 1325 in this manner, the G light (polarized light) is modulated by the operation of the liquid crystal due to the electric field formed between the pixel electrode 1326g and the counter electrode 1324 by a signal voltage applied to the pixel electrode 1326g. Exit the liquid crystal panel,
It returns to PBS1303.

Here, the PBS surface 1 depends on the degree of modulation.
The amount of light reflected at 303a and traveling toward the projection lens 1301 changes, and so-called gray-scale gradation display of each pixel is performed. On the other hand, as described above, the cross section (y-
For R light incident from an oblique direction in the (z plane),
When attention is paid to, for example, an R ray incident on the microlens 1322b after being polarized by the PBS 1303, as shown by an arrow R (in) in the figure, the light is condensed by the microlens 1322b and is located on the left side immediately below. The R pixel electrode 1326r at the shifted position is illuminated. Then, the reflected light is reflected by the pixel electrode 1326r, and as shown in FIG.
322a and exits out of the panel (R (ou
t)).

At this time, the R light (polarized light) is also applied to the opposite electrode 13 by the signal voltage applied to the pixel electrode 1326r.
The liquid crystal panel is modulated by the operation of the liquid crystal by an electric field corresponding to the image signal formed between the liquid crystal panel 24 and the liquid crystal panel, and exits the liquid crystal panel.
It returns to PBS1303. Then, after that, the image light is projected from the projection lens 1301 in exactly the same manner as in the case of the G light described above. By the way, in the depiction of FIG. 20, the G light and the R light on the pixel electrode 1326g and the pixel electrode 1326r partially overlap each other and interfere with each other. This is schematically represented by the thickness of the liquid crystal layer. Is actually exaggerated, and the thickness of the liquid crystal layer is actually 1 to 5 μm.
The thickness is very thin as compared with the sheet glass 1323 of 50 to 100 μm, and such interference does not occur regardless of the pixel size.

Next, FIG. 21 is a diagram for explaining the principle of color separation / color synthesis in this example. Here, FIG. 21 (a) is a schematic top view of the liquid crystal panel 1302, and FIGS. 21 (b) and 21 (c) are AA ′ (X
3 is a schematic cross-sectional view of FIG. Here, the micro lens 1322 is formed as shown in FIG.
As shown by the one-dot chain line, one for each half of the two adjacent color pixels centering on the G light. FIG. 21C corresponds to FIG. 20 showing the yz cross section, and shows how the G light and the R light incident on each micro lens 1322 enter and exit. As can be seen from this, each G pixel electrode is disposed immediately below the center of each microlens, and each R pixel electrode is disposed immediately below the boundary between each microlens. Therefore, the angle of incidence of the R light is
is preferably set to be equal to the ratio of the pixel pitch (B & R pixel) to the distance between the microlens and the pixel electrode. On the other hand, FIG. 21B shows x-rays of the liquid crystal panel 1302.
This corresponds to the y section. In this xy section, the B pixel electrodes and the G pixel electrodes are alternately arranged as in FIG. 21C, and each G pixel electrode is also arranged immediately below the center of each microlens, and The pixel electrodes are arranged immediately below the boundaries between the microlenses.

As described above, the B light illuminating the liquid crystal panel is incident on the oblique direction of the cross section (xy plane) in FIG. 16 after being polarized by the PBS 1303 as described above. In exactly the same manner, the B ray incident from each microlens 1322 is reflected by the B pixel electrode 1326b as shown in the figure, and exits from the microlens 1322 adjacent to the incident microlens 1322 in the x direction. The modulation by the liquid crystal on the B pixel electrode 1326b and the projection of the B emission light from the liquid crystal panel are the same as the above-described G light and R light.

Each B pixel electrode 1326b is disposed immediately below the boundary between the microlenses, and the incident angle of B light to the liquid crystal panel is the same as that of R light.
It is preferable to set nθ to be equal to the ratio between the pixel pitch (G & B pixel) and the distance between the microlens and the pixel electrode. By the way, in the liquid crystal panel of this example, as described above, the arrangement of each RGB pixel is RGRGRG in the z direction.
Are arranged in the x-direction, and FIG. 21 (a) shows a planar arrangement thereof. As described above, each pixel size is about half of the microlens in both the vertical and horizontal directions, and the pixel pitch is half of that of the microlens in both the x and z directions. Also,
The G pixel is also located directly below the center of the microlens in plan view, the R pixel is located between the G pixels in the z direction and at the microlens boundary, and the B pixel is located between the G pixels in the x direction and at the microlens boundary. I have. Further, the shape of one microlens unit is rectangular (double the size of a pixel).

FIG. 22 is a partially enlarged top view of the present liquid crystal panel. Here, a broken-line grid 1329 in the figure indicates a group of RGB pixels constituting one picture element. That is, when each of the RGB pixels is driven by the active matrix driving circuit unit 1327 in FIG. 20, the RGB pixel units indicated by the broken-line lattice 1329 correspond to the RGB corresponding to the same pixel position.
Driven by the B video signal. Here, the R pixel electrode 1326
Focusing on one pixel composed of r, G pixel electrode 1326g and B pixel electrode 1326b,
26r is the micro lens 13 as indicated by the arrow r1.
As described above, the illumination light is illuminated with the R light obliquely incident from the light source 22b, and the R reflected light is emitted through the microlens 1322a as indicated by an arrow r-2. B pixel electrode 1326
b denotes a micro lens 1322 as indicated by an arrow b1.
As described above, light is illuminated with B light obliquely incident from c,
The B reflected light exits through the microlens 1322a as shown by the arrow b2. G pixel electrode 13
26g is illuminated with the G light incident vertically (in the direction toward the back of the paper) from the micro lens 1322a as described above, as indicated by the front rear arrow g12, and the G reflected light is transmitted vertically through the same micro lens 1322a ( (Direction of coming out of the page).

As described above, in the present liquid crystal panel, 1
Regarding the RGB pixel units constituting one picture element, although the incident illumination position of each primary color illumination light is different, their emission is the same micro lens (1322 in this case).
a). This is also true for all other picture elements (RGB pixel units).

Therefore, as shown in FIG. 23, all the light emitted from the present liquid crystal panel is transmitted to the PBS 1303 and the projection lens 13.
When the image is projected on the screen 1309 through the optical system 01 and optically adjusted so that the position of the micro lens 1322 in the liquid crystal panel 1302 is image-formed and projected on the screen 1309, the projected image becomes a micro lens lattice as shown in FIG. Each of the picture elements has a mixed state of the light emitted from the RGB pixel units constituting each picture element, that is, a picture element in a mixed color state of the same pixel. In addition, it is possible to display a good color image with high texture without a so-called RGB mosaic.

Next, as shown in FIG. 20, the above-described pixel electrodes 1326 and the active matrix drive circuit portion 1327 provided on the silicon semiconductor substrate 1328 for actively driving the pixel electrodes 1326 will be described in detail. The active matrix driving circuit portion 1327 includes each pixel electrode 1326
In FIG. 20, the RGB pixels constituting the picture element are simply drawn side by side on the circuit cross-sectional view of FIG. 20, but the drain of each pixel FET has a two-dimensional structure as shown in FIG. To each of the RGB pixel electrodes 1326 in a specific arrangement.

FIG. 24 is an overall block diagram of a driving circuit system of the projection type liquid crystal display device. Here, reference numeral 1310 denotes a panel driver which inverts the polarity of an RGB video signal and forms a liquid crystal drive signal obtained by a predetermined voltage amplification.
Various timing signals are formed. An interface 1312 decodes various video and control transmission signals into standard video signals and the like. Reference numeral 1311 denotes a decoder which decodes and converts a standard video signal from the interface 1312 into an RGB primary color video signal and a synchronization signal, that is, an image signal corresponding to the liquid crystal panel 1302. Reference numeral 1314 denotes a ballast for driving and lighting an arc lamp 1308 in the elliptical reflector 1307. 1
A power supply circuit 315 supplies power to each circuit block. Reference numeral 1313 denotes a controller including an operation unit (not shown), which comprehensively controls the respective circuit blocks. As described above, in the projection type liquid crystal display device, the drive circuit system is very common as a single-panel projector, and the drive circuit system does not particularly burden the drive circuit system and has no RGB mosaic as described above. It is possible to display a color image with a natural texture.

By the way, in FIG.
Although the example in which the G pixel electrodes 1326 g are arranged just below the center of the center 22 is shown, as another form, the micro lens 1322
B pixel electrodes 1326b may be arranged at a position directly below the center, and G pixels 1326g may be arranged alternately in the horizontal direction, and R pixels 1326r may be arranged alternately in the vertical direction. Even in this arrangement, the B light is vertically incident, and the R / G light is obliquely incident (same angle and different directions) so that the reflected light from the RGB pixel unit constituting the picture element is emitted from one common microlens. ), The same effect as in the previous example can be obtained. Further, R pixels may be arranged just below the center of the microlens 1322, and G and B pixels may be alternately arranged with respect to the R pixels in the left and right or up and down directions.

Next, the relationship between the seal structure and the panel structure will be described with reference to FIG. In FIG.
Reference numeral 51 denotes a seal portion, 52 denotes an electrode pad, 53 denotes a clock buffer circuit, and 54 denotes an amplifier. This amplifier 54
Is used as an output amplifier at the time of panel electrical inspection. 55 is an Ag paste part for taking the potential of the counter substrate,
56 is a display area, 57 is a horizontal / vertical shift register (H
(SR, VSR). As shown in FIG. 25, in this embodiment, circuits are provided both inside and outside the seal so that the total chip size is reduced. In this embodiment, the pad drawers are concentrated on one side of the panel. However, both sides on the long side can be taken out from multiple sides instead of one side. Sometimes effective.

Further, since the panel of the present invention uses a semiconductor substrate such as a Si substrate, strong light is irradiated as in a projector, and when light is applied to the side walls of the substrate, the substrate potential fluctuates. Panel malfunction may occur. Therefore, the side wall of the panel and the peripheral circuit portion of the display area on the top surface of the panel are a substrate holder capable of shielding light, and the back surface of the Si substrate has a high thermal conductivity through an adhesive having a high thermal conductivity. It has a holder structure in which metals such as Cu are connected.

Next, a reflective electrode structure and a method of manufacturing the same, which are the points of the present invention, will be described. The completely flat reflective electrode structure of the present invention is different from the usual method of patterning and polishing a metal, in advance, the groove is etched in advance at the electrode pattern, the metal is formed there, This is a novel method of removing the metal on the region where the electrode pattern is not formed by polishing and also flattening the metal on the electrode pattern. Moreover, the width of the wiring is much wider than the region other than the wiring, and the common problem of the conventional etching apparatus causes the following problem, and the structure of the present invention cannot be manufactured.

That is, when etching is performed, a polymer is deposited during the etching, and patterning cannot be performed. The polymer is considered to be a polymer composed of a reaction product generated when a resist is sputtered, a reaction product of a material to be etched, or a gas itself.

Therefore, oxide film type etching (CF4 / C
HF3 system). The result is shown in FIG. 13 described above. FIG. 13A is a characteristic diagram when the total pressure is 1.7 torr, and FIG.
FIG. 4 is a characteristic diagram when the pressure is 1.0 torr.

As shown in FIG. 13A, when the total pressure is 1.7 torr, the deposition gas C
When HF3 is reduced, the polymer deposition is certainly reduced, but the dimensional difference (loading effect) between the pattern close to the resist and the pattern far from the resist is extremely large, which indicates that the use is difficult.

As a result of repeated experiments, the present inventors have found that when the pressure is gradually reduced to suppress the loading effect, the loading effect is considerably suppressed when the pressure becomes 1 Torr or less, and the deposition gas CHF3 is reduced. It was found that etching with only CF4 was effective with CHF3 set to zero.

Further, in the structure in which the pixel electrode 12 is provided only in the display area, a groove is formed in the insulating layer by etching only in the display area in order to provide the pixel electrode. The resist does not exist, and the structure is formed in the peripheral region by the resist. However, it is difficult to form such a structure, and as a structure, the empty electrode 12 in the peripheral region equivalent to the pixel electrode 12 is formed. It has been found that it is effective to provide the area around the display area.

By adopting this structure, there is no step between the conventional display portion and the peripheral portion or the seal portion, the gap accuracy is increased, the in-plane uniform pressure is increased, and the unevenness at the time of liquid crystal injection is increased. The effect of obtaining high quality image with good yield was obtained.

FIG. 26 shows an overall block diagram of a driving circuit system of the projection type liquid crystal display device. Here, reference numeral 1310 denotes a panel driver which inverts the polarity of an RGB video signal and forms a liquid crystal drive signal obtained by a predetermined voltage amplification.
Various timing signals are formed. An interface 1312 decodes various video and control transmission signals into standard video signals and the like. Reference numeral 1311 denotes a decoder which decodes and converts a standard video signal from the interface 1312 into an RGB primary color video signal and a synchronization signal, that is, an image signal corresponding to the liquid crystal panel 1302. Reference numeral 1314 denotes a ballast for driving and lighting an arc lamp 1308 in the elliptical reflector 1307. 1
A power supply circuit 315 supplies power to each circuit block. Reference numeral 1313 denotes a controller including an operation unit (not shown), which comprehensively controls the respective circuit blocks. As described above, in the projection type liquid crystal display device, the drive circuit system is very common as a single-panel projector, and the drive circuit system does not particularly burden the drive circuit system and has no RGB mosaic as described above. It is possible to display a color image with a natural texture.

FIG. 27 is a partially enlarged top view of another form of the liquid crystal panel in the present embodiment. Here, the B pixel electrode 13 is located just below the center of the micro lens 1322.
26b are arranged, and the G pixels 1326 are arranged in the horizontal direction.
The R pixels 1326r are arranged so as to be alternately arranged in the vertical direction so that g are alternately arranged. Even in this arrangement, the B light is vertically incident, and the R / G light is obliquely incident (same angle and different directions) so that the reflected light from the RGB pixel unit constituting the picture element is emitted from one common microlens. ), The same effect as in the previous example can be obtained. Further, R pixels may be arranged just below the center of the microlens 1322, and G and B pixels may be alternately arranged with respect to the R pixels in the left and right or up and down directions.

[0131]

According to the present invention described above, since the video line of the liquid crystal display element is divided, the chip size can be reduced, the power consumption can be reduced, and the reliability can be reduced as compared with the case where a circuit is inserted. Various effects can be achieved such that it is possible to produce a liquid crystal display device with high performance and high definition and high contrast without ghosts at low cost and with high reliability.

In addition, as for the peripheral circuit, not only the surface of the liquid crystal display element but also the surface of the peripheral circuit are overlaid with a PSG insulating layer and a reflective metal electrode and planarized by CMP, so that the reliability of the liquid crystal display device itself is improved. Can be improved, and the number of manufacturing steps can be reduced, and various effective effects can be obtained.

Further, in the projection type liquid crystal display device according to the present invention, one picture element is constituted by using a reflection type liquid crystal panel with microlenses and an optical system for illuminating each primary color light from different directions. Since the reflected light after modulation by the liquid crystal from the set of RGB pixels is emitted through the same microlens, a high quality and good color image projection display without RGB mosaic can be realized.

Further, since the luminous flux from each pixel passes through the microlens twice and is almost parallelized, a bright projected image can be obtained on the screen even if an inexpensive projection lens having a small numerical aperture is used. Become.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a driving circuit of a liquid crystal panel according to the present invention.

FIG. 2 is a diagram illustrating the relationship between the output of a horizontal shift register, the output of a vertical shift register, and the timing of a video line of a liquid crystal panel according to the present invention.

FIG. 3 is a diagram illustrating a relationship between an output of a vertical shift register, a reset pulse, and a signal line potential when performing a field reset of a liquid crystal panel according to the present invention.

FIG. 4 is an example of an output pulse of a horizontal shift register of a liquid crystal panel according to the present invention.

FIG. 5 is an example of a detailed view of a conventional liquid crystal panel drive circuit.

FIG. 6 is an example of a detailed diagram of a liquid crystal panel drive circuit according to the present invention.

FIG. 7 is a diagram showing a relationship between an output of a vertical shift register, a reset pulse, and a signal line potential when performing a field reset of a liquid crystal panel according to the present invention.

FIG. 8 is a sectional view of a liquid crystal device manufactured by CMP according to the present invention.

FIG. 9 is a schematic circuit diagram of a liquid crystal device according to the present invention.

FIG. 10 is a block diagram of a liquid crystal device according to the present invention.

FIG. 11 is a circuit diagram including a delay circuit of an input unit of the liquid crystal device according to the present invention.

FIG. 12 is a conceptual diagram of a liquid crystal panel of a liquid crystal device according to the present invention.

FIG. 13 is a graph for judging pass / fail of an etching process in manufacturing a liquid crystal device according to the present invention.

FIG. 14 is a conceptual diagram of a liquid crystal projector using the liquid crystal device according to the present invention.

FIG. 15 is a circuit block diagram showing the inside of the liquid crystal projector according to the present invention.

FIG. 16 is an overall configuration diagram showing an embodiment of an optical system of a projection type liquid crystal display device according to the present invention.

FIG. 17 is a spectral reflection characteristic diagram of a dichroic mirror used in an optical system of a projection type liquid crystal display device according to the present invention.

FIG. 18 is a perspective view of a color separation illumination unit of the optical system of the projection type liquid crystal display device according to the present invention.

FIG. 19 is a partially enlarged view of a conventional transmission type liquid crystal panel with microlenses.

FIG. 20 is a sectional view showing an example of a liquid crystal panel according to the present invention.

FIG. 21 is a diagram illustrating the principle of color separation and color synthesis of a liquid crystal panel according to the present invention.

FIG. 22 is a partially enlarged view of a liquid crystal panel according to the present invention.

FIG. 23 is a partial configuration diagram showing a projection optical system of a projection type liquid crystal display device according to the present invention.

FIG. 24 is a partially enlarged view of a projected image on a screen of the projection type liquid crystal display device according to the present invention.

FIG. 25 is a schematic overall plan view of a liquid crystal panel according to the present invention.

FIG. 26 is a block diagram showing a driving circuit system of the projection type liquid crystal display device according to the present invention.

FIG. 27 is a partially enlarged view of a projected image on a screen of a projection type liquid crystal display device according to the present invention.

FIG. 28 is a manufacturing process diagram of a conventional active matrix substrate by the present applicant.

FIG. 29 is a manufacturing process diagram of a conventional active matrix substrate by the present applicant (continued).

[Explanation of symbols]

 1, horizontal shift register 3 vertical shift register 4-11 video signal line 12-23 switching MOS transistor 24-35 vertical signal line 101 reset pulse 102 signal line voltage 388 control board 389 filter safety switch 453 main board 454 liquid crystal panel drive head Board 455, 456, 457 Liquid crystal device 516 Video line 1220 Micro lens (reflow heat sag type) 1251 Spacer column 1252 Peripheral seal 1301 Projection lens 1302 Liquid crystal panel with micro lens 1303 Polarizing beam splitter (PBS) 1306 Rod type integrator 1307 Elliptical reflector 1308 Arc lamp 1309 Screen 1310 Panel driver 1311 Decoder 1312 Interface Road 1314 Ballast (arc lamp lighting circuit) 1320 Liquid crystal panel with micro lens 1321 Micro lens glass substrate 1322 Micro lens (index distribution type) 1323 Sheet glass 1324 Opposing transparent electrode 1325 Liquid crystal 1326 Pixel electrode 1327 Active matrix drive circuit section 1328 Silicon semiconductor substrate 1329 Basic picture element unit 1340 R reflection dichroic mirror 1341 B / G reflection dichroic mirror 1342 B reflection dichroic mirror 1343 High reflection mirror 1350 Fresnel lens (second condenser lens) 1351 First condenser lens

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H092 GA59 JA25 JB07 KA03 KA19 MA27 MA37 NA19 NA27 PA01 PA06 PA07 PA08 PA09 PA13 QA15 RA05 5C094 AA03 AA22 BA03 BA43 CA19 DA09 DA13 EB05 ED01 ED05 GA10 HA10 JA20

Claims (10)

[Claims] A semiconductor substrate, a substrate facing the semiconductor substrate,
A liquid crystal display portion including liquid crystal sealed between these substrates is provided, and the liquid crystal is turned on / off by a liquid crystal driving voltage applied to pixel electrodes formed in a matrix on the liquid crystal side surface of the semiconductor substrate. A matrix substrate to be turned off, wherein the number of video lines is larger than the number of simultaneously written pixels. 2. A liquid crystal display comprising a pixel electrode substrate, a substrate facing the pixel electrode, and a liquid crystal sealed between these substrates, wherein a matrix-like liquid crystal display portion is provided on a surface of the pixel electrode substrate on the liquid crystal side. 1. A liquid crystal display device in which liquid crystal is turned on / off by a liquid crystal driving voltage applied to a pixel electrode formed in the liquid crystal display device, wherein the number of video lines is larger than the number of simultaneously written pixels. 3. The liquid crystal display device according to claim 2, further comprising a switch for changing a delay amount of the sampling pulse. 4. A display device using the liquid crystal display device according to claim 2. 5. A liquid crystal projector device, wherein the liquid crystal display device according to claim 2 is a reflection type and displays an image signal. 6. The liquid crystal display section includes a semiconductor substrate on which the pixel electrodes are formed, an active matrix drive circuit section including the divided video signal lines, a pixel electrode, a liquid crystal layer, a counter transparent electrode, and a sheet. 3. The liquid crystal display device according to claim 2, wherein the liquid crystal display device has a structure in which glass and glass are sequentially laminated. 7. The liquid crystal display according to claim 6, wherein a micro lens is formed on the sheet glass, and one element of the micro lens is formed for every two of the pixel electrodes. apparatus. 8. The liquid crystal display device according to claim 7, wherein the microlenses are formed on a microlens glass substrate on the sheet glass. 9. A liquid crystal projector device, wherein the liquid crystal display device according to claim 6 is a reflection type and displays an image signal. 10. A liquid crystal display unit including at least three liquid crystal display units including the divided video signal lines for three colors, separating blue light by a high reflection mirror and a blue reflection dichroic mirror, and further comprising a red reflection dichroic mirror. 10. The liquid crystal projector device according to claim 9, wherein red and green are separated by a green / blue reflecting dichroic mirror and each of the liquid crystal display units is projected.