JPH10325949A - Substrate for liquid crystal panel, its production, liquid crystal panel and electronic appliance using liquid crystal panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the quantity of light leaked and to diminish a leakage current in a reflection type LCD using a semiconductor as a substrate by forming a reflecting electrode and a light shielding layer which shields light from the gap in the electrode from the same electrically conductive layer. SOLUTION: An insulating film 9 of SiO2 , etc., coating a data line 7 and an Al circuit 8 is made flat, an insulating film 10 of silicon nitride, etc., having a higher etching selection rate than the insulating film 9 is formed and an insulating film 11 of SiO2 , etc., having a lower etching selection rate than the insulating film 10 is further formed. The surface of the film 11 is coated with a resist mask except a part corresponding to the gap in an image element electrode 14 and isotropic etching is carried out. Since the insulating films 9-11 are different from each other in etching selection rate and the film 10 has the highest etching selection rate, after an opening is formed in the surface film 11, the film 10 is rapidly and widely etched to form a groove for a light shielding layer. The image element electrode 14 is then formed, e.g. by a low temp. sputtering method. At the same time, a light shielding layer 15 is formed in the groove.

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 reflection type liquid crystal display device, and more particularly to an active matrix type LCD in which pixel electrodes are driven by MOSFETs (insulated gate type field effect transistors) formed on a semiconductor substrate. (Liquid crystal display device).

[0002]

2. Description of the Related Art Conventionally, a reflective active matrix L
As the CD, there is an LCD having a structure in which a TFT array using amorphous silicon is formed on a glass substrate, and a pixel electrode serving as a reflection electrode is formed thereon via an interlayer insulating film, and the TFT is driven by the TFT. Has been put to practical use.

[0003]

Since the reflection type active matrix LCD using the above-mentioned TFT has a relatively large device size, for example, in a projection type display device such as a projector incorporating this as a light valve, the reflection type active matrix LCD has a large size. There is a problem that the whole becomes large.

On the other hand, the reflection type active matrix L
As a reflection type LCD smaller in size than a CD, there is one in which a pixel electrode serving as a reflection electrode is driven by a MOSFET array formed on a semiconductor substrate.

However, the semiconductor substrate has a problem that a leak current flows when light leaks from a gap between each pixel electrode and passes through a PN junction (source / drain region of a pixel electrode driving FET). .

[0006] In addition, since an LCD using a semiconductor as a substrate has a well region, a leak current may flow only when light leaks not only through a transistor portion but also through a semiconductor substrate distant therefrom. That is, there is a disadvantage that the number of locations where light leakage current flows in the substrate is larger than that of an LCD in which TFTs are formed in an island shape on a glass substrate.

Therefore, a MOS formed on a semiconductor substrate
Although a structure in which a light-shielding layer is inserted between the FET array and the pixel electrode is conceivable, the above structure increases the number of steps and separates the MOSFET array from the pixel electrode. There is a problem that it becomes difficult.

An object of the present invention is to provide a technique capable of reducing the amount of leaked light to reduce the leak current in a reflective LCD using a semiconductor as a substrate.

[0009]

In order to achieve the above object, the present invention provides a pixel region in which reflective electrodes are arranged in a matrix on the same semiconductor substrate and peripheral circuits such as shift registers and control circuits outside the pixel region. In the reflection-type liquid crystal panel substrate on which was formed, the reflection electrode and the light-shielding layer for shielding the gap between the reflection electrodes were formed of the same conductive layer. Further, a groove for a light-shielding layer and an eave above the groove are formed on the surface of the insulating film forming the reflective electrode, and the reflective electrode and the light-shielding layer are formed in the same conductive layer in a self-aligned manner. I did it.

[0010] A first element for shielding circuit elements of a peripheral circuit from light.
The light-shielding layer and the wiring layer, and the second light-shielding layer that shields the gap between the first light-shielding layer and the wiring layer were formed of the same layer. Further, a groove for a light shielding layer is formed on the surface of the insulating film on which the wiring layer is formed, and an eave for insulating the first light shielding layer or the wiring layer and the second light shielding layer is formed above the groove. And the light shielding layer are formed in a self-aligned manner.

A pad to which a signal or voltage is externally supplied, a first light-shielding layer for shielding the periphery thereof, and a second light-shielding layer for shielding a gap between the pad and the first light-shielding layer are the same layer. Formed. Further, on the surface of the insulating film on which the pad is formed, a groove for the light-shielding layer and an eave for insulating the first light-shielding layer or the wiring layer from the second light-shielding layer are formed on the groove and the pad. And a light-shielding layer therearound are formed in a self-aligned manner.

Thus, the gap between the reflective electrode, the gap between the wiring layer and the light-shielding layer of the peripheral circuit, and the gap between the pad and the light-shielding layer around the pad, cause the light incident thereon to pass through the groove for the light-shielding layer. The light is shielded by the light shielding layer formed in the substrate, so that P
Light leakage current flowing to the N junction can be prevented. In addition, the presence of the eaves allows the light-shielding layer or electrode on the upper part of the eaves and the light-shielding layer in the groove to be arranged so as to overlap each other. Furthermore, since both can be insulated by the presence of the eaves, the number of steps does not increase.

Further, in order to form the light shielding layer groove and the eaves above the groove, after forming insulating films having different etching selectivity, isotropic etching is performed through a resist mask. did.

Thus, the light leakage current in the semiconductor substrate can be reduced without increasing the number of steps due to the light shielding layer.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of a reflection-side substrate of a reflection type LCD to which the present invention is applied. FIG. 1 is a cross-sectional view of one pixel portion among pixels arranged in a matrix. FIG. 2 shows a method of forming the light shielding portion A in FIG.

In FIG. 1, reference numeral 1 denotes a P-type semiconductor substrate such as single crystal silicon (an N-type semiconductor substrate may be used), and 2 denotes a P-type well region having a higher impurity concentration than a substrate formed on the surface of the semiconductor substrate 1. Reference numeral 3 denotes a field oxide film (so-called LOCO) for element isolation formed on the surface of the semiconductor substrate 1.
S). The well region 2 is not particularly limited, but is formed as a common well region of pixels such as 768 × 1024, and constitutes peripheral circuits such as a data line driving circuit, a gate line driving circuit, an input circuit, and a timing control circuit. It is formed separately from the well region where the element is formed.

An opening is formed in the field oxide film 3, and a gate oxide film (not shown in the figure, but formed by thermal oxidation on the surface of a well region (substrate) serving as a channel of a transistor) is formed in the center of the inside of the opening. A gate electrode 4 made of polysilicon or the like is formed, and source and drain regions 5a and 5b made of a high impurity concentration N-type diffusion layer are formed on the substrate surface on both sides of the gate electrode 4. , MOSFET. One of the source and drain regions 5a and 5b (5a in the figure)
Above the BPSG (Boron Phosphorus Silica Gras
s) A data line 7 made of a first aluminum layer is formed via an insulator 6 such as a film, and a part of the data line 7 is formed in a contact hole formed in the insulating film 6 by a source / drain region. 5a. An aluminum wiring 8 made of the same aluminum layer as the data line 7 is formed, and a part of the aluminum wiring 8 is electrically connected to the source / drain region 5b through a contact hole formed in the insulating film 6. Have been.

An insulating film 9 made of silicon dioxide or the like, which is an LTO (Low Temperature Oxide), is formed so as to cover the data line 7 and the aluminum wiring 8, and then flattened by a CMP (chemical mechanical polishing) method. As shown in FIG. 2A, after the insulating film 9 is planarized, an insulating film 10 such as silicon nitride having an etching selectivity higher than that of the insulating film 9 is formed. The insulating film 11 made of silicon dioxide or the like having a small LTO is formed. Note that the etching selectivity of the insulating films 9 and 11 may be the same, or may be different from each other as long as the etching selectivity is smaller than that of the insulating film 10.

The aluminum wiring 8 is provided in the insulating films 9-11.
In order to electrically connect the pixel electrode 14 and the connection electrode 12 made of tungsten or the like, a CVD
It is buried by a method or the like. As shown in FIG. 2B, when the connection plugs 12 are formed, the connection plugs 12 are covered with a resist mask except for portions that are to be gaps between the pixel electrodes 14 arranged in a matrix, and isotropic etching is performed.
Since the etching selectivity of the insulating films 9 to 11 is different and the insulating film 10 has the highest etching selectivity, the insulating film 10 is quickly and largely etched after the opening of the insulating film 11 on the surface. The light-shielding layer groove 13 is formed leaving the insulating film 11 in an eaves shape.

As shown in FIG. 2C, after the isotropic etching, a pixel electrode 14 as a reflective electrode made of aluminum or the like is formed by, for example, a low-temperature sputtering method. 15 is the pixel electrode 1
4 and at the same time, they are formed in a self-aligned manner. The pixel electrode 14 is not electrically connected to the light shielding layer 15 due to the eaves formed on the insulating film 11.
After the formation of the pixel electrode 14, an oxide film made of LTO or the like is formed on the pixel electrode as passivation.

According to the present invention, a transistor for supplying an image signal from a data signal line to a pixel electrode can be shielded from light by arranging a pixel electrode serving as a reflective electrode above the transistor. The current can be suppressed. Further, the light incident from the gap between the pixel electrodes is shielded by the light shielding layer formed in the groove for the light shielding layer, so that the light from this gap flows into the transistor and the PN junction in the substrate. Light leakage current can be prevented. Since the end of the pixel electrode and the light-shielding layer in the groove overlap each other due to the presence of the eaves, light can be more reliably shielded. Further, since the pixel electrode and the light shielding layer can be formed at the same time, they can be insulated by the presence of the eaves.
Does not increase the number of processes. In the embodiment, the metal wiring layers are two layers 7 and 8, but a three-layer wiring structure is adopted.
The uppermost layer may be the pixel electrode 14 and the light shielding layer 15.

FIG. 3 shows N as an example of a peripheral circuit 20 formed on the same semiconductor substrate 1 as the transistor of the pixel.
1 shows a CMOS inverter composed of a type transistor 21 and a P-type transistor 22. The power supply voltage Vcc is applied from the Vcc main line 27 (wired in the vertical direction in the figure) to the connection plug 1
The power is supplied to the source of the P-type transistor 22 via the 2 · Vcc branch line 24. The ground voltage GND is connected to the GND main line 28.
(Wired in the vertical direction in the figure) to connection plug 12G
Connected to the source of N-type transistor 21 via ND branch line 25. That is, wiring is performed by two layers of metal. Reference numeral 23 denotes a gate wiring serving as a gate electrode of the P-type transistor and the N-type transistor, and reference numeral 26 denotes an output wiring drawn from the drain of the CMOS transistor.

FIG. 4 is a sectional view taken along line XX in FIG. G above
On the ND branch line 25, insulating films 9 to
11 are stacked. The GND branch line 25 is connected to the connection plug 12.
Is electrically connected to the above-mentioned GND main line.
A resist mask is formed on the insulating films 9 to 11 while leaving a gap between the wiring region and the circuit element region, and isotropically etched to form the light shielding layer groove 13. After the isotropic etching, a light-shielding layer made of aluminum or the like is formed by sputtering or the like, so that the Vcc main line 27 and the G
Not only the ND main line 28 but also the light-shielding layer 2 that shields circuit elements
9a and a light-shielding layer 29b that shields the substrate below the gap between the circuit element and the wiring are formed in a self-aligned manner, and the wiring layer and the light-shielding layer can be formed by the same conductive layer. Due to the eaves formed on the insulating film 11, the Vcc main line 27 and the GND main line 28 are separated from the light shielding layer 29.
a, 29b are not electrically connected. In addition, V
cc main line 27, GND main line 28, light shielding layer 29
Reference numerals a and 29b denote the same conductive layer formed simultaneously with the pixel electrode 14. It is needless to say that a light-shielding method different from the structure shown in FIG. 1 may be adopted in the pixel region, and the light-shielding method described in the embodiment may be adopted only in the peripheral region.

According to the present invention, a transistor constituting a peripheral circuit such as a drive circuit for supplying a voltage to a data line or a gate line can be shielded from light by disposing a light shielding layer above the transistor. Light leakage current can be suppressed. Further, since the wiring of the peripheral circuit has a light shielding function, light leakage in the semiconductor substrate below the wiring can be suppressed. Light incident from the gap between the light-shielding layer and the wiring layer is shielded by the light-shielding layer formed in the groove for the light-shielding layer. It is possible to prevent a light leak current flowing in the section. Note that the presence of the eaves allows the wiring layer and the light-shielding layer to be arranged so as to overlap with each other, so that light-shielding can be performed more reliably. Further, although the wiring layer and the light shielding layer can be formed at the same time, both can be insulated by the presence of the eaves, so that the number of steps is not increased. FIG. 5 shows a pad region 30 formed in the peripheral region of the pixel region on the semiconductor substrate 1 and for inputting a signal from outside. The wiring 31 made of the first metal layer is electrically connected via the connection plug 12 to the pad portion 32 of a metal layer such as aluminum formed on the upper layer. Areas other than the pad section 32 are light-shielding layers 33a and 33b made of the same conductive layer as the pad section 32. Light shielding layer 3
Since 3b is formed in the light-shielding layer groove 13 formed by the same structure and manufacturing method as shown in FIG. 2, the pad portion 32 and the light-shielding layers 33a and 33b are not electrically connected. Further, the pad portion 32 and the light shielding layer 33a,
33b is the same conductive layer formed simultaneously with the pixel electrode 14.

According to the present invention, the pad and the semiconductor substrate around the pad can be shielded from light by the pad portion and the light shielding layer, and the light leakage current in the substrate can be suppressed. Also, light incident from the gap between the light-shielding layer and the pad portion is blocked by the light-shielding layer formed in the groove for the light-shielding layer.
Light leakage current flowing to the junction can be prevented. Note that the presence of the eaves allows the pad portion and the light-shielding layer to be arranged so as to overlap each other, so that light-shielding can be performed more reliably. Further, although the pad portion and the light shielding layer can be formed at the same time, both can be insulated by the presence of the eaves, so that the number of steps is not increased. As shown in the above embodiment, by using the manufacturing method of the present invention, the reflection electrode of the reflection type liquid crystal panel, the wiring of the peripheral circuit, the pad portion, and the light shielding layer can be realized by the same conductive layer in a self-aligned manner.

FIG. 6 shows a sectional configuration of a reflection type liquid crystal panel using a liquid crystal panel substrate (reflection side substrate) 41 to which the above embodiment is applied. On the opposite side of the liquid crystal panel substrate 41,
An incident side glass substrate 43 having a counter electrode 42 made of a transparent conductive film (ITO) to which an LC common potential is applied is disposed at an appropriate interval, and TN is disposed in a gap surrounded by a sealing material 44. (Twisted Nematic) type liquid crystal or SH (Super Homeotropic) type liquid crystal 45 is filled to form a liquid crystal panel 40. The position where the sealing material is provided is designed so that the pad region 30 for inputting a signal from the outside is located outside the sealing material 44. In a pixel region formed on the reflection-side substrate, as is well known, data lines and gate lines intersect each other and are arranged in a matrix. In each pixel, a pixel electrode serving as a reflection electrode is arranged in an upper layer. A transistor is formed on the semiconductor substrate (well region) below the pixel electrode.
A gate electrode of the transistor is connected to a gate line, a source is connected to a data line, and a drain is electrically connected to a pixel electrode. A driving circuit for supplying a voltage (signal) to each of the gate line and the data line is formed in a peripheral portion of the pixel region. The voltage of the image signal supplied from the data line driving circuit is supplied to the pixel electrode via the transistor turned on by the source line driving circuit, and the potential difference between the pixel electrode and the counter electrode is applied to the liquid crystal layer sandwiched therebetween. Is done. In addition,
Although not shown in the drawings of the above embodiments, each pixel has
Usually, a capacitor for storing and holding the voltage of the image signal is formed on the semiconductor substrate below the pixel electrode.

FIG. 7 shows an example of an electronic apparatus using the liquid crystal panel 40 of the present invention. The main part of a projector (projection display device) using the reflective liquid crystal panel of the present invention as a light valve is shown in plan view. It is the schematic block diagram seen. This FIG.
Is a cross-sectional view in the XZ plane passing through the center of the optical element 130. The projector of this example includes a light source unit 110 and an integrator lens 12 arranged along the system optical axis L.
0, a polarized light illuminating device 100 which is roughly composed of a polarization conversion element 130, a polarized beam splitter 200 for reflecting an S-polarized light beam emitted from the polarized light illuminating device 100 by an S-polarized light beam reflecting surface 201,
A dichroic mirror 412 that separates a blue light (B) component from the light reflected from the polarization reflection surface 201;
A reflective liquid crystal light valve 300B that modulates the separated blue light (B) into blue light; a dichroic mirror 413 that reflects and separates the red light (R) component of the light beam after the blue light is separated; The reflective liquid crystal light valve 300R that modulates the red light (R), the reflective liquid crystal light valve 300G that modulates the remaining green light (G) that passes through the dichroic mirror 413, and the three reflective liquid crystal light valves 300R and 300G. , 300B are combined by dichroic mirrors 412, 413 and polarizing beam splitter 200, and a projection optical system 500 composed of a projection lens for projecting the combined light onto screen 600.
It is composed of The above-described liquid crystal panel is used for each of the three reflective liquid crystal light valves 300R, 300G, and 300B.

The randomly polarized light beam emitted from the light source unit 110 is split into a plurality of intermediate light beams by the integrator lens 120, and the polarization direction is substantially changed by the polarization conversion element 130 having the second integrator lens on the light incident side. After being converted into one kind of polarized light beam (S-polarized light beam), the light reaches the polarization beam splitter 200. The S-polarized light beam emitted from the polarization conversion element 130 is reflected by the S-polarized light beam reflection surface 2 of the polarizing beam splitter 200.
01, the blue light (B) of the reflected light is reflected by the blue light reflecting layer of the dichroic mirror 412 and modulated by the reflective liquid crystal light valve 300B. Also, dichroic mirror 411
Among the light beams transmitted through the blue light reflecting layer, the light beam of red light (R) is reflected by the red light reflecting layer of the dichroic mirror 413 and is modulated by the reflective liquid crystal light valve 300R.

On the other hand, the luminous flux of green light (G) transmitted through the red light reflecting layer of the dichroic mirror 413 is modulated by the reflection type liquid crystal light valve 300G. Thus, each of the reflective liquid crystal light valves 300R, 300R
0G, 300B modulation reflection type liquid crystal light valve 3
The reflective liquid crystal panels of 00R, 300G, and 300B are provided with a TN type liquid crystal (a liquid crystal in which the long axis of liquid crystal molecules is oriented substantially parallel to the panel substrate when no voltage is applied) or an SH type liquid crystal (where the long axis of the liquid crystal molecules is A liquid crystal that is oriented substantially perpendicular to the panel substrate when no voltage is applied is employed.

When a TN type liquid crystal is employed, the voltage applied to the liquid crystal layer sandwiched between the reflective electrode of the pixel and the common electrode of the opposing substrate is lower than the threshold voltage of the liquid crystal (OFF). Pixel), the incident color light is elliptically polarized by the liquid crystal layer, is reflected by the reflective electrode, and passes through the liquid crystal layer.
The light is reflected and emitted as light in a state close to elliptically polarized light having a large polarization axis component substantially shifted by 90 degrees from the polarization axis of the incident color light.
On the other hand, in a pixel (ON pixel) applied with a voltage to the liquid crystal layer,
The incident color light reaches the reflective electrode as it is, is reflected, and is reflected and emitted with the same polarization axis as that at the time of incidence. Since the alignment angle of the liquid crystal molecules of the TN type liquid crystal changes according to the voltage applied to the reflective electrode, the angle of the polarization axis of the reflected light with respect to the incident light depends on the voltage applied to the reflective electrode via the transistor of the pixel. Variable.

When the SH type liquid crystal is employed, the pixel (OF) in which the voltage applied to the liquid crystal layer is lower than the threshold voltage of the liquid crystal.
F pixel), the incident color light reaches the reflection electrode as it is, is reflected, and is reflected and emitted with the same polarization axis as that at the time of incidence. On the other hand, in a pixel (ON pixel) to which a voltage is applied to the liquid crystal layer, the incident color light is elliptically polarized by the liquid crystal layer, reflected by the reflective electrode, and passes through the liquid crystal layer with respect to the polarization axis of the incident light. Is reflected and emitted as elliptically polarized light having a large polarization axis component shifted by about 90 degrees. As in the case of the TN type liquid crystal,
Since the alignment angle of the liquid crystal molecules of the TN type liquid crystal changes according to the voltage applied to the reflective electrode, the angle of the polarization axis of the reflected light with respect to the incident light depends on the voltage applied to the reflective electrode via the transistor of the pixel. Variable.

Of the color lights reflected from the pixels of the liquid crystal panel, the S-polarized light component does not pass through the polarization beam splitter 200 that reflects the S-polarized light, while the P-polarized light component does. An image is formed by the light transmitted through the polarizing beam splitter 200. Therefore, the projected image is T
When the N-type liquid crystal is used for the liquid crystal panel, the reflected light of the OFF pixel reaches the projection optical system 500 and the reflected light of the ON pixel does not reach the lens, so that a normally white display is obtained. The reflected light does not reach the projection optical system and the reflected light of the ON pixel reaches the projection optical system 500, so that normally black display is performed.

The reflection type liquid crystal panel uses a TFT on a glass substrate.
Compared to an active matrix type liquid crystal panel having an array, the number of pixels can be formed more by using semiconductor technology, and the panel size can be made smaller, so that a high-definition image can be projected and a projector can be formed. Can be reduced in size.

The peripheral circuit portion of the liquid crystal panel is covered with a light-shielding film, and has the same potential (for example, an LC common potential) as well as a common electrode formed at a position opposed to the opposite substrate. Since the potential is different from that of the common electrode, in this case, a peripheral counter electrode separated from the common electrode of the pixel portion is applied.) Therefore, almost 0 V is applied to the liquid crystal interposed therebetween, and It becomes the same as the OFF state. Therefore, in the liquid crystal panel of the TN type liquid crystal, all the periphery of the image region can be displayed white in accordance with the normally white display, and in the liquid crystal panel of the SH type liquid crystal, the periphery of the image region can be entirely black in accordance with the normally black display. Can be displayed.

According to the above embodiment, the reflection type liquid crystal panel 3
The voltage applied to each of the pixel electrodes 00R, 300G, and 300B is sufficiently maintained, and a clear image is obtained because the reflectance of the pixel electrodes is extremely high.

FIG. 8 is an external view showing an example of an electronic apparatus using the reflection type liquid crystal panel of the present invention. In these electronic devices, the reflective electrode is not required to be a perfect mirror surface, and is not used as a light valve used with a polarizing beam splitter, but as a direct-view reflective liquid crystal panel. It is preferable to provide appropriate irregularities, but the other components are basically the same as those of the light valve.

FIG. 8A is a perspective view showing a mobile phone. 1000 denotes a mobile phone body, of which 100
Reference numeral 1 denotes a liquid crystal display unit using the reflection type liquid crystal panel of the present invention.

FIG. 8B is a diagram showing a wristwatch-type electronic device. 1100 is a perspective view showing the watch main body. 11
Reference numeral 01 denotes a liquid crystal display unit using the reflection type liquid crystal panel of the present invention. Since this liquid crystal panel has higher definition pixels than a conventional clock display unit, it can also display television images, and can realize a wristwatch type television.

FIG. 8C is a diagram showing a portable information processing device such as a word processor or a personal computer. 1200 denotes an information processing apparatus, 1202 denotes an input unit such as a keyboard, 120
Reference numeral 6 denotes a display unit using the reflective liquid crystal panel of the present invention;
Reference numeral 4 denotes an information processing apparatus main body. Since each electronic device is a battery-driven electronic device, the use of a reflective liquid crystal panel without a light source lamp can extend the battery life. Further, since the peripheral circuit can be built in the panel substrate as in the present invention, the number of components can be greatly reduced, and the weight and size can be further reduced.

[0041]

As described above, according to the present invention, the light-shielding layer is formed by the same layer as the conductive layer serving as the reflection electrode. Light hardly reaches the pixel driving transistor, and light leakage current is reduced.

Further, in the peripheral circuit, the wiring and the light-shielding layer can be formed by the same conductive layer, so that the two-layer wiring and the light-shielding can be realized while suppressing an increase in the number of steps, and the malfunction of the circuit due to the light leakage current can be prevented. .

Since the nitride film lowers the reflectance of the reflective electrode and cannot be used as surface passivation, an oxide film is used in a reflective liquid crystal panel. However, the oxide film does not sufficiently shield moisture. In the present invention, since a nitride film is used as the insulating film below the reflective electrode, there is also an aspect that moisture can be shielded.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a reflection-side substrate pixel portion of a reflection type LCD to which the present invention is applied.

FIG. 2 is a sectional view showing an embodiment of a method for forming the portion A in FIG. 1;

FIG. 3 is a plan view showing an embodiment of a peripheral circuit on the reflection side substrate of the reflection type LCD to which the present invention is applied.

FIG. 4 is a view showing a cross section taken along line XX of FIG. 3;

FIG. 5 is a plan view showing an embodiment of a reflection-side substrate pad portion of a reflection type LCD to which the present invention is applied.

FIG. 6 is a cross-sectional view illustrating an example of a reflective liquid crystal panel to which the liquid crystal panel substrate according to the embodiment is applied.

FIG. 7 is a schematic configuration diagram of an electronic device using the reflective liquid crystal panel of the embodiment and a projection display device as an example.

FIG. 8 is an external view of an electronic device using the reflective liquid crystal panel of the embodiment and a mobile phone (a), a wristwatch (b), and a computer (c) as an example.

[Explanation of symbols]

 Reference Signs List 1 semiconductor substrate 3 element isolation region (LOCOS) 4 gate line 5a, 5b source / drain region 7 data line 12 connection plug 13 light-shielding groove 14 pixel electrode (reflective electrode) 15 light-shielding layer 21 N-type transistor 22 P-type transistor 23 input signal Line 24 Vcc branch line 25 GND branch line 26 Output signal line 27 Vcc main line 28 GND main line 29a, 29b Light shielding layer 31 Wiring 32 Pad 33a, 33b Light shielding layer 41 Liquid crystal panel substrate 42 Counter electrode 43 Incident side glass substrate 44 Sealing material 45 liquid crystal

Claims (16)

[Claims] At least one reflection electrode is formed in a matrix on a semiconductor substrate, and a transistor is formed corresponding to each reflection electrode, and a voltage is applied to the reflection electrode via the transistor. A liquid crystal panel substrate, comprising: a light-shielding layer formed of the same conductive layer as that of the reflective electrode. 2. A transistor connected to each of the reflective electrodes and a transistor constituting a peripheral circuit for supplying a voltage to a gate electrode and a data line of the transistor are formed on the same semiconductor substrate. 2. The liquid crystal panel substrate according to claim 1, wherein the light-shielding layer is formed by the same conductive layer as the wiring layer to be formed. 3. The liquid crystal panel substrate according to claim 1, wherein a groove for a light shielding layer is formed on a surface of the insulating film on which the reflective electrode or the wiring layer of the peripheral circuit is formed. 4. The liquid crystal panel according to claim 3, wherein an eave for insulating the light shielding layer from the reflection electrode or the wiring layer of the peripheral circuit and the light shielding layer is formed above the light shielding layer groove. substrate. 5. The light shielding layer groove and the eaves above the groove are formed of different insulating films.
4. The liquid crystal panel substrate according to 1. 6. A method in which at least reflective electrodes are formed in a matrix on a semiconductor substrate, and transistors are formed corresponding to the respective reflective electrodes, and a voltage is applied to the reflective electrodes via the transistors. A liquid crystal panel substrate having a peripheral circuit formed around a pixel region in which the reflective electrodes are formed in a matrix, comprising: a first light-shielding layer and a wiring layer for shielding circuit elements of the peripheral circuit; A second light-shielding layer that shields a gap between the first light-shielding layer and the wiring layer;
Wherein the light-shielding layers are formed of the same layer. 7. The insulating film on which the wiring layer is formed,
7. The liquid crystal panel substrate according to claim 6, wherein a groove for a light shielding layer is formed. 8. The light shielding layer according to claim 7, wherein an eave for insulating the first light shielding layer or the wiring layer from the second light shielding layer is formed above the light shielding layer groove. Substrate for liquid crystal panel. 9. At least a plurality of reflective electrodes are formed in a matrix on a semiconductor substrate, and transistors are respectively formed corresponding to the respective reflective electrodes so that a voltage is applied to the reflective electrodes via the transistors. In the liquid crystal panel substrate thus configured, a pad to which a signal or voltage is externally supplied, a first light-shielding layer that shields the periphery thereof, and a second light-shielding layer that shields a gap between the pad and the first light-shielding layer A substrate for a liquid crystal panel, wherein the layers are constituted by the same layer. 10. A groove for a light shielding layer is formed on the surface of the insulating film on which the pad is formed.
4. The liquid crystal panel substrate according to 1. 11. The light shielding layer according to claim 10, wherein an eave for insulating the first light shielding layer or the wiring layer from the second light shielding layer is formed above the light shielding layer groove. Substrate for liquid crystal panel. 12. A structure in which at least reflective electrodes are formed in a matrix on a semiconductor substrate, transistors are formed corresponding to the respective reflective electrodes, and a voltage is applied to the reflective electrodes via the transistors. After the transistor and the first conductive layer are formed on the semiconductor substrate, an interlayer insulating film is formed on the semiconductor substrate, and a groove having an eaves is formed on the surface of the interlayer insulating film. A method for manufacturing a substrate for a liquid crystal panel, wherein a light shielding layer is formed simultaneously with the formation. 13. The groove on the surface of the interlayer insulating film and the eaves above the groove are formed by isotropically etching insulating films having different etching selectivity.
3. The method for manufacturing a liquid crystal panel substrate according to item 2. 14. The method according to claim 13, wherein the insulating films having different etching selectivity are a silicon dioxide film and a silicon nitride film. 15. The liquid crystal panel substrate according to any one of claims 1 to 11, and an incident side transparent substrate having a counter electrode are arranged at an appropriate interval, and the liquid crystal panel substrate is A liquid crystal panel, wherein liquid crystal is sealed in a gap between the transparent substrate and the transparent substrate. 16. An electronic apparatus using the liquid crystal panel according to claim 15 as a display device.