JP2004206134A - Substrate for liquid crystal panel, liquid crystal panel, and electronic appliance and projection display apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems that a silicon nitride film which is produced by a reduced pressure CVD method and generally used as a passivation film in a semiconductor device, causes about 10% variance in the film thickness and that when the obtained film is used for a reflective liquid crystal panel, the reflectance varies much or the reflectance of the liquid crystal fluctuates by the variance in the film thickness of the passivation film. <P>SOLUTION: The substrate for a liquid crystal panel is constituted in such a manner that a reflective electrode (14) is formed in a matrix on a substrate (1), a transistor is fabricated corresponding to each reflective electrode, and a voltage is applied on the reflective electrode via the transistor. In this substrate, a silicon oxide film having 500 to 2,000Å film thickness is used as the passivation film (17) and the film thickness is properly controlled in accordance with the wavelength of light entering the film. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a liquid crystal panel, and more particularly to a reflection type liquid crystal panel, and more particularly to a technique suitable for use in an active matrix type liquid crystal panel in which pixel electrodes are switched by switching elements formed on a semiconductor substrate or an insulating substrate. Furthermore, the present invention relates to an electronic device and a projection display device using the same.

  Conventionally, as an active matrix liquid crystal panel used for a light valve of a projection display device, a liquid crystal panel having a structure in which a thin film transistor (TFT) array using amorphous silicon is formed on a glass substrate has been put to practical use.

  The active matrix liquid crystal panel using the TFT is a transmissive liquid crystal panel, in which pixel electrodes are formed of a transparent conductive film. In a transmissive liquid crystal panel, the area where a switching element such as a TFT provided in each pixel is formed is not a transmissive area. Therefore, the aperture ratio is originally low, and as the resolution of the panel increases to XGA and SVGA, the aperture ratio decreases. Has the fatal defect of becoming

  Therefore, as a liquid crystal panel smaller in size than a transmissive active matrix liquid crystal panel, a reflective active matrix liquid crystal panel in which a pixel electrode serving as a reflective electrode is switched by a transistor formed on a semiconductor substrate or an insulating substrate is considered. It has come to be.

  Conventionally, such a reflective liquid crystal panel has been omitted because it is not necessary to provide a passivation film as a protective film on a substrate on which a reflective electrode is formed. Therefore, the present inventors have studied the provision of a passivation film on a reflective liquid crystal panel substrate.

  Generally, in a semiconductor device, a silicon nitride film formed by a low-pressure CVD method or the like is often used as a passivation film. By the way, it is difficult to avoid a variation of about 10% of the film thickness of the passivation film formed by the CVD method using the current technology. However, in the reflective liquid crystal panel, there is a problem that the reflectance changes greatly due to the variation in the thickness of the passivation film, and the refractive index of the liquid crystal changes.

  An object of the present invention is to provide a highly reliable reflective liquid crystal panel substrate and a liquid crystal panel having a passivation film whose reflectance does not vary greatly.

  Another object of the present invention is to provide a reflective liquid crystal panel having high reliability and excellent image quality, and an electronic apparatus and a projection display device using the same.

  According to the present invention, in order to achieve the above object, reflective electrodes are formed in a matrix on a substrate, and transistors are formed corresponding to the respective reflective electrodes, and a voltage is applied to the reflective electrodes via the transistors. In the liquid crystal panel substrate configured as described above, a passivation film is formed on the reflective electrode. As a result, the reflective electrode is not exposed, so that the reliability is improved.

  Further, the passivation film has a thickness selected so that the change in the reflectance of the reflective electrode with respect to the wavelength of the incident light is within about 1%. Due to the thickness of the passivation film on the reflective electrode, it is possible to prevent the reflectance from being varied among the color lights, and to prevent the color reproducibility from being deteriorated when performing color display.

  Further, the passivation film is formed of silicon oxide. Although the silicon oxide film has a somewhat inferior function as a protective film as compared with the silicon nitride film, the influence of the variation in the film thickness on the reflectance of the pixel electrode is smaller than that of the silicon nitride film, and silicon oxide has good stress resistance. Since cracks are unlikely to occur, it is most suitable for use as a passivation film in a region occupying most of the chip area such as a pixel region. Therefore, by forming this passivation film from a silicon oxide film, it is possible to suppress the phenomenon that the reflectance at the reflective electrode greatly varies depending on the wavelength of light.

  Further, the passivation film is a silicon oxide film having a thickness of 500 to 2000 Å. Accordingly, a silicon oxide film having a thickness of 500 to 2,000 angstroms, in particular, has a small wavelength dependence of the reflectance. Therefore, by using the silicon oxide film as the passivation film, the variation in the reflectance can be reduced. .

  Further, the thickness of the passivation film is set to an appropriate range in accordance with the wavelength of incident light. This makes it possible to make the thickness of the passivation film different according to the wavelength, thereby reducing the wavelength dependence of the reflectance by the reflective electrode.

  Further, when the reflective electrode reflects blue light, the thickness of the silicon oxide film serving as the passivation film formed on the reflective electrode is 900 to 1200 Å, and the reflective electrode reflects green light. The thickness of the silicon oxide film serving as the passivation film formed on the reflective electrode is set to 1200 to 1600 Å, and when the reflective electrode reflects red light, the passivation film formed on the reflective electrode is formed. The thickness of the silicon oxide film to be a film is 1300 to 1900 angstroms. When the thickness of the silicon oxide film serving as the passivation film is set in the above range, the variation in the reflectance for each color can be suppressed to 1% or less, and the reliability of the liquid crystal panel can be improved, and this can be achieved. It is possible to improve image quality in a projection display device using a reflective liquid crystal panel as a light valve.

  Further, an alignment film having a thickness of 300 to 1400 angstroms is formed on the silicon oxide film. Further, the thickness of the silicon oxide film may be set in relation to the thickness of the alignment film formed thereon. In this case, a suitable thickness of the alignment film is 300 to 1400 angstroms, preferably 800 to 1400 angstroms. By setting the thickness of the alignment film in the above range, it is possible to effectively prevent a change in reflectance.

  Further, an interlayer insulating film made of silicon nitride is formed between the reflective electrode and a metal layer therebelow. Since a silicon oxide film is formed in the pixel region as a passivation film, the moisture resistance is reduced. However, since the interlayer insulating layer of the silicon nitride film is provided below the reflective electrode, deterioration of the moisture resistance in the pixel region can be prevented.

  Further, an interlayer insulating film between the reflective electrode and a metal layer therebelow is composed of a silicon nitride film and a silicon oxide film, and has a laminated structure in which the silicon nitride film is formed on the silicon oxide film. It is characterized by the following. If the interlayer insulating film is formed only of a silicon nitride film, cracks are likely to occur. However, by forming a laminated structure with a silicon oxide film, moisture resistance and stress resistance can be improved.

  Further, the thickness of the passivation film on the reflective electrode that reflects red light is 1300 to 1900 angstroms, the thickness of the passivation film on the reflective electrode that reflects green light is 1200 to 1600 angstroms, and blue light is reflected. The reflective electrode has a thickness of 900 to 1200 angstroms. Thus, when color display is to be performed by one reflective liquid crystal panel, variation in the reflectance of each color light is reduced, and color reproducibility of color display can be improved.

Further, the liquid crystal panel is configured such that reflective electrodes are formed in a matrix on the substrate, transistors are formed corresponding to the respective reflective electrodes, and a voltage is applied to the reflective electrodes via the transistors. On the substrate,
A passivation film made of silicon nitride is formed in an end region of the substrate. The layered structure at the edge of the peripheral region of the pixel region is most susceptible to moisture and the like. Therefore, a moisture-resistant silicon nitride film passivation film is formed at this edge to improve the moisture resistance of the liquid crystal panel substrate. Can be improved.

  Further, the passivation film has a stacked structure of a silicon oxide film and a silicon nitride film formed on the silicon oxide film. The reinforcement structure of the panel substrate can be constituted by using the passivation film as a two-layer structure, thereby improving the durability.

Further, the reflective electrodes are formed in a matrix on the substrate, and transistors are respectively formed corresponding to the reflective electrodes, and each pixel unit is configured such that a voltage is applied to the reflective electrodes via the transistors. Liquid crystal panel substrates,
A passivation film made of silicon oxide is formed above a pixel region in which the pixel unit is formed, and a passivation film made of silicon nitride is formed above a peripheral region located around the pixel region. Features. Although the silicon oxide film has a somewhat inferior function as a protective film as compared with the silicon nitride film, the influence of the variation in the film thickness on the reflectance of the pixel electrode is smaller than that of the silicon nitride film, and silicon oxide has good stress resistance. Since cracks are unlikely to occur, it is most suitable for use as a passivation film in a region occupying most of the chip area such as a pixel region. By forming this passivation film from a silicon oxide film, it is possible to suppress the phenomenon that the reflectance at the reflective electrode greatly varies depending on the wavelength of light. Further, the laminated structure at the end of the peripheral region of the pixel region is most susceptible to moisture and the like. Therefore, by forming a water-resistant silicon nitride film passivation film at this end, the moisture resistance of the liquid crystal panel substrate can be reduced. Performance can be improved.

Further, the passivation film having a laminated structure of the silicon oxide and the silicon nitride formed on the silicon oxide film is provided at least in a seal region where the liquid crystal panel substrate and the counter substrate in the peripheral region are bonded. Is formed. Thus, the seal portion becomes a passivation film having a two-layer structure, and the seal portion, which is subjected to pressure during assembly of the liquid crystal panel, can have a reinforcing structure.

Further, the liquid crystal panel is configured such that reflective electrodes are formed in a matrix on the substrate, transistors are formed corresponding to the respective reflective electrodes, and a voltage is applied to the reflective electrodes via the transistors. On the substrate,
An interlayer insulating film having a stacked structure of a silicon oxide film and a silicon nitride film is formed between the reflective electrode and a metal layer below the reflective electrode. Since the pixel region has a two-layer structure of silicon oxide in which cracks are less likely to occur and silicon nitride having good moisture resistance, durability can be improved.
Further, a light-shielding layer of the same layer as the reflective electrode is formed above a peripheral circuit region of a pixel region in which the pixel unit is formed, and a stack of the silicon oxide film and the silicon nitride film is formed below the light-shielding layer. It is characterized in that an interlayer insulating film having a structure is formed. Although the peripheral circuit region is apt to enter moisture such as water, the durability can be improved by adopting a two-layer structure of silicon oxide and silicon nitride having good moisture resistance, in which this region does not easily crack.

The interlayer insulating film is formed of the silicon nitride film formed on the silicon oxide film, and the silicon nitride film has a contact for connecting the pixel electrode and the lower conductive layer in a region of the pixel electrode. It is characterized in that only the hole is opened. By doing so, the opening of the silicon nitride film becomes smaller, so that moisture can be made more difficult to enter.
Further, the liquid crystal panel substrate and the substrate on the light incident side are opposed to each other with a gap, and liquid crystal is sealed in the gap to provide a reflective liquid crystal panel. be able to.

  Further, an electronic device including the liquid crystal panel as a display portion and having a display portion with low power consumption and high contrast can be provided.

  20. A miniaturized projection display device comprising: a light source; a liquid crystal panel according to claim 19 for modulating light from the light source; and projection optical means for projecting light modulated by the liquid crystal panel. can do.

A color separating unit that splits the light of the light source into three color lights; a first liquid crystal panel that modulates red light separated by the color separating unit; and a green light that is separated by the color separating unit. A second liquid crystal panel that modulates the light and a third liquid crystal panel that modulates the blue light separated by the color separation means, and a silicon oxide film that forms a passivation film of the first liquid crystal panel The thickness is in the range of 1300 to 1900 angstroms, the thickness of the silicon oxide film for forming the passivation film of the second liquid crystal panel is in the range of 1200 to 1600 angstroms, and the oxidation for forming the passivation film of the third liquid crystal panel. The thickness of the silicon film is in the range of 900 to 1200 angstroms. Accordingly, since the passivation film thickness corresponding to the wavelength of the color light to be modulated is obtained for each light valve that modulates each color light, the variation in the reflectance is reduced, and the variation in the combined light is also reduced. Accordingly, it is possible to prevent a phenomenon in which the color of the color display of the projection light is different for each product of the projection display device. That is, it is possible to provide a projection display device in which the reflection characteristics of each light valve are improved and a bright projection image is formed.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Explanation of liquid crystal panel substrate using semiconductor substrate)
1 and 3 show a first embodiment of a reflective electrode side substrate of a reflective liquid crystal panel to which the present invention is applied. 1 and 3 show a cross-sectional view and a planar layout of one pixel portion among the pixels arranged in a matrix. FIG. 1A shows a cross section taken along line II in FIG. FIG. 1B shows a cross section along the line II-II in FIG. FIG. 6 is a plan layout view of the entire reflective electrode side substrate of the reflective liquid crystal panel of the present invention.

In FIG. 1, reference numeral 1 denotes a P-type semiconductor substrate such as single-crystal silicon (which may be an N-type semiconductor substrate (N ⁻ )), and 2 denotes a higher impurity concentration formed on the surface of the semiconductor substrate 1 than the semiconductor substrate. The P-type well region 3 is a field oxide film (so-called LOCOS) for element isolation formed on the surface of the semiconductor substrate 1. Although not particularly limited, the well region 2 is formed as a common well region of a pixel region in which pixels are arranged in a matrix such as 768 × 1024. As shown in FIG. 6, the well region 2 includes a data line drive circuit 21, a gate line drive circuit 22, an input circuit 23, and a timing circuit arranged around a pixel region 20 in which pixels are arranged in a matrix. It is formed separately from the well region where the elements constituting the peripheral circuit such as the control circuit 24 are formed. The field oxide film 3 is formed to have a thickness of 5000 to 7000 angstroms by selective thermal oxidation.

  Two openings are formed in the field oxide film 3 for each pixel, and polysilicon or metal is formed at the center inside one of the openings via a gate oxide film (insulating film) 4b formed by thermal oxidation. A gate electrode 4a made of silicide or the like is formed, and source and drain regions 5a and 5b made of a high impurity concentration N-type impurity introduction layer (hereinafter referred to as a doping layer) are formed on the substrate surface on both sides of the gate electrode 4a. Thus, a MOSFET is configured. The gate electrode 4a extends in the scanning line direction (pixel row direction) to form the gate line 4.

  Further, a P-type doping region 8 is formed on the surface of the substrate inside the other opening formed in the field oxide film 3, and the surface of the P-type doping region 8 is formed by thermal oxidation. An electrode 9a made of polysilicon or metal silicide is formed via an insulating film 9b, and a voltage applied to a pixel is held between the electrode 9a and the P-type doping region 8 with the insulating film 9b interposed. A storage capacitor is configured. The electrode 9a is formed in the same step as the polysilicon or metal silicide layer serving as the gate electrode 4a of the MOSFET, and the insulating film 9b under the electrode 9a is formed in the same step as the insulating film serving as the gate insulating film 4b. be able to.

  The insulating films 4b and 9b are formed to a thickness of 400 to 800 Å on the surface of the semiconductor substrate inside the opening by thermal oxidation. The electrodes 4a and 9a are formed by forming a polysilicon layer to a thickness of 1000 to 2000 angstroms and further forming a silicide layer of a high melting point metal such as Mo or W to a thickness of 1000 to 3000 angstroms. The structure is made. The source and drain regions 5a and 5b are formed in a self-aligned manner by implanting N-type impurities into the substrate surfaces on both sides thereof by ion implantation using the gate electrode 4a as a mask. The well region immediately below the gate electrode 4a becomes the channel region 5c of the MOSFET.

Further, the P-type doping region 8 is formed by, for example, a dedicated ion implantation and doping process by heat treatment, and may be formed by an ion implantation method before forming a gate electrode. That is, after the formation of the insulating films 4b and 9b, an impurity of the same conductivity type as that of the well is implanted, and the surface of the well is formed as a region 8 having a higher impurity concentration than the well with lower resistance. The impurity concentration of the well region 2 is preferably 1 × 10 ¹⁷ / cm ³ or less, and preferably about 1 × 10 ^{16 to} 5 × 10 ¹⁶ / cm ³ . The preferred surface impurity concentration of the source and drain regions 5a and 5b is 1 × 10 ^{20 to} 3 × 10 ²⁰ / cm ³ , and the preferred surface impurity concentration of the P-type doping region 8 is 1 × 10 ^{18 to} 5 × 10 ¹⁹ / cm ³ . However, from the viewpoint of the reliability and the withstand voltage of the insulating film constituting the storage capacitor, 1 × 10 ¹⁸ to 1 × 10 ¹⁹ / cm ³ is particularly preferable.

  A first interlayer insulating film 6 is formed from the electrodes 4a and 9a to the field oxide film 3. On the insulating film 6, a data line 7 (see FIG. 3) composed of a metal layer mainly composed of aluminum and a A source electrode 7a and an auxiliary coupling line 10 formed to protrude from the data line are provided. Source electrode 7a is electrically connected to source region 5a through contact hole 6a formed in insulating film 6, and one end of auxiliary coupling wire 10 is electrically connected to drain region 5b through contact hole 6b formed in insulating film 6. The other end is electrically connected to the electrode 9a via a contact hole 6c formed in the insulating film 6.

  The insulating film 6 is formed, for example, by depositing an HTO film (a silicon oxide film formed by a high-temperature CVD method) on the order of 1000 angstroms and then forming a BPSG film (a silicate glass film containing boron and phosphorus) from 8000 to 10000 angstroms. It is formed by depositing to a thickness. The metal layer forming the source electrode 7a (data line 7) and the auxiliary coupling wiring 10 has, for example, a four-layer structure of Ti / TiN / Al / TiN from the bottom. Each layer has a thickness such that the lower layer has a thickness of 100 to 600 angstroms, the TiN has a thickness of about 1000 angstroms, the Al has a thickness of 4000 to 10000 angstroms, and the upper layer has a thickness of 300 to 600 angstroms.

  A second interlayer insulating film 11 is formed from the source electrode 7a and the auxiliary coupling wiring 10 to the interlayer insulating film 6, and a second metal layer 12 mainly composed of aluminum is formed on the second interlayer insulating film 11. Is formed. The second metal layer 12 forming the light shielding layer is formed as a metal layer forming a wiring for connection between elements in a peripheral circuit such as a drive circuit formed around the pixel region as described later. It is. Therefore, there is no need to add a step for forming only the light shielding layer 12, and the process is simplified. In the light-shielding layer 12, an opening 12a is formed at a position corresponding to the auxiliary coupling wiring 10 so as to penetrate a column-shaped connection plug 15 for electrically connecting a pixel electrode and a MOSFET described later, Other portions are formed so as to cover the entire pixel region 20. That is, in the plan view shown in FIG. 3, a rectangular frame denoted by reference numeral 12 a represents the opening, and the entire outside of the opening 12 a is the light shielding layer 12. Thereby, light incident from above (the liquid crystal layer side) in FIG. 1 is almost completely blocked to prevent light from passing through the channel region 5c and the well region 2 of the pixel switching MOSFET and causing a light leakage current to flow. be able to.

  The second interlayer insulating film 11 is formed, for example, by depositing a silicon oxide film (hereinafter referred to as a TEOS film) formed by a plasma CVD method using TEOS (tetraethylorthosilicate) as a material for about 3000 to 6000 angstroms, and then an SOG film. (Spin-on-glass film) is deposited, is etched back, and then a second TEOS film is further deposited thereon to a thickness of about 2000 to 5000 Å. The second metal layer 12 constituting the light-shielding layer may have the same structure as the first-layer metal layers 7 (7a) and 10, and has, for example, a four-layer structure of Ti / TiN / Al / TiN from the bottom. Each layer has a thickness such that the lowermost layer has a thickness of 100 to 600 angstroms, the upper layer has a thickness of about 1000 angstroms, the upper layer has a thickness of 4000 to 10000 angstroms, and the uppermost layer has a thickness of 300 to 600 angstroms.

  In this embodiment, a third interlayer insulating film 13 is formed on the light shielding layer 12, and a rectangular shape corresponding to substantially one pixel is formed on the third interlayer insulating film 13 as shown in FIG. A pixel electrode 14 is formed as a reflective electrode having a shape. Further, a contact hole 16 penetrating through the third interlayer insulating film 13 and the second interlayer insulating film 11 is provided so as to be located inside the opening 12a provided in the light shielding layer 12 and corresponding thereto. The contact hole 16 is filled with a columnar connection plug 15 made of a refractory metal such as tungsten for electrically connecting the auxiliary coupling line 10 and the pixel electrode 14. Further, a passivation film 17 is entirely formed on the pixel electrode 14.

  When constructing a liquid crystal panel, an alignment film is further formed on the reflective electrode side substrate, and a counter electrode (common electrode) is arranged on the inner surface at a predetermined interval so as to face the substrate, and alignment is performed thereon. A liquid crystal panel is formed by opposing the opposing substrates on which the films are formed, and filling liquid crystal in the gaps.

  Although not particularly limited, after tungsten or the like constituting the connection plug 15 is deposited by a CVD method, the tungsten and the third interlayer insulating film 13 are flattened by CMP (chemical mechanical polishing), and then the pixel electrode 14 is formed. Is formed, for example, by forming an aluminum layer to a thickness of 300 to 5000 angstroms by a low-temperature sputtering method, and by patterning to form a square shape with one side of about 15 to 20 μm. As a method of forming the connection plug 15, there is also a method in which the third interlayer insulating film 13 is planarized by a CMP method, a contact hole is opened, and tungsten is deposited in the contact hole. As the passivation film 17, a silicon oxide film having a thickness of about 500 to 2000 angstroms is used in the pixel area, and a thickness of about 2000 to 10000 angstroms is used in the peripheral area, the seal portion, and the scribe portion of the substrate. A silicon nitride film is used. Note that the seal portion indicates a formation region of a sealant for bonding and fixing a pair of substrates forming a liquid crystal panel with a gap therebetween. The scribe portion is a portion along a scribe region when a large number of the reflective liquid crystal panel substrates of the present invention are formed on a semiconductor wafer and are diced into semiconductor chips along scribe lines and separated. (Ie, the end of the liquid crystal panel substrate).

  In addition, by using a silicon oxide film as the passivation film 17 covering the pixel region portion, it is possible to suppress a phenomenon that the reflectance largely changes due to a variation in the film thickness or the reflectance greatly changes depending on the wavelength of light.

  On the other hand, the passivation film 17 covering the peripheral region of the substrate, particularly the region outside the region where the liquid crystal is sealed (outside the seal portion), is used as a protective film as compared with the silicon oxide film in terms of water resistance of the substrate. The reliability is further improved by using a superior silicon nitride film and forming a single-layer structure of the silicon nitride film or a protective film having a two-layer structure in which a silicon nitride film is formed on a silicon oxide film. be able to. That is, in the peripheral region of the substrate exposed to the outside air, particularly in the scribe portion, moisture and the like easily enter therethrough, but since that portion is covered with the protective film of the silicon nitride film, the reliability and durability can be improved.

  When a liquid crystal panel is constructed, an alignment film made of polyimide is formed on the entire surface of the passivation film 17 and rubbed.

  Further, the thickness of the passivation film 17 may be set to an appropriate range in accordance with the wavelength of incident light. Specifically, the thickness of the silicon oxide film serving as a passivation film is 900 to 1200 angstroms for a pixel electrode that reflects blue light, and the thickness of the silicon oxide film is 1200 to 1600 angstroms for a pixel electrode that reflects green light. The thickness of the silicon oxide film in the pixel electrode that reflects red light is 1300 to 1900 angstroms. By setting the thickness of the silicon oxide film serving as the passivation film within the above range, the variation in the reflectance of the reflective electrode formed of the aluminum layer for each color can be suppressed to 1% or less. Hereinafter, the reason will be described.

  FIGS. 10 and 11 show the results of examining how the reflectance of the reflective electrode of the aluminum layer changes with the thickness of the silicon oxide film at each wavelength. In FIG. 10, the symbol ◆ indicates the reflectance when the film thickness is 500 Å, the symbol □ indicates the reflectance when the film thickness is 1000 Å, and the symbol ▲ indicates the reflectance when the film thickness is 1500 Å. , And the x mark plots the reflectance when the film thickness is 2000 Å. In FIG. 11, the mark Δ represents the reflectance when the film thickness was set to 1000 Å, the mark □ represents the reflectance when the film thickness was set to 2000 Å, and the mark ▲ represents the reflectance when the film thickness was set to 4000 Å. The mark x is plotted with the reflectivity when the film thickness is set to 8000 angstroms.

  As can be seen from FIG. 11, when the film thickness is 4000 angstroms, the reflectance decreases from 0.89 to 0.86 by about 3% while the wavelength changes from 450 to 550 nm, and the wavelength changes from 700 to 800 nm. The reflectivity drops by about 8% from 0.85 to 0.77. When the film thickness is 8000 angstroms, the reflectivity decreases by about 3% from 0.89 to 0.86 while the wavelength changes from 500 to 600 nm, and becomes 0 while the wavelength changes from 650 to 750 nm. It has dropped by about 6% from 0.86 to 0.80. On the other hand, when the film thickness is 500 angstroms, 1000 angstroms, 1500 angstroms, or 2000 angstroms, such a sharp change is not seen in the reflectance. For the above reasons, it can be seen that the effective range of the thickness of the silicon oxide film is 500 to 2000 Å.

  Therefore, when a reflective liquid crystal panel is formed, a reflective liquid crystal panel having a small wavelength dependence of reflectance can be obtained by obtaining a film thickness in the range of 500 to 2,000 angstroms as a passivation film formed on a reflective electrode. It can be seen that it can be configured.

  Further, from FIGS. 10 and 11, it can be seen from the local wavelength range that there is a range in which the amount of change in reflectance is small depending on the thickness of the silicon oxide film. In addition, the present inventor considered that there might be an optimum thickness range of the silicon oxide film depending on the incident and reflected color light, and examined it in more detail. The results are shown in FIGS. Of these, FIG. 12 plots the reflectance for each appropriate wavelength when the thickness of the silicon oxide film is changed in the wavelength range of 420 to 520 nm around blue, and FIG. The reflectance is similarly plotted for each appropriate wavelength for the nearby wavelength range of 500 to 600 nm, and FIG. 14 is similarly plotted for each appropriate wavelength for the wavelength range of 560 to 660 nm centered on red. Things.

  As can be seen from FIG. 12, when the film thickness is 800 angstroms, the reflectance decreases from 0.896 to 0.882 by about 1.1% while the wavelength changes from 440 to 500 nm. When the film thickness is 1300 angstroms, while the wavelength changes from 420 to 470 nm, the reflectance changes from 0.887 to 0.893 by about 0.6%, and the wavelength changes from 420 to 450 nm. The reflectivity is considerably lower than in the case of other film thicknesses. On the other hand, when the film thickness is 900 angstroms, 1000 angstroms, 1100 angstroms, or 1200 angstroms, such a sharp change is not seen in the reflectance, and a sufficient value of the reflectance is obtained. I have.

  As can be seen from FIG. 13, when the film thickness is 1100 angstroms, the reflectivity decreases from 0.882 to 0.866 by about 1.6% while the wavelength changes from 550 to 600 nm. When the film thickness is 1700 angstroms, the reflectance at a wavelength of 500 to 530 nm is considerably lower than that at other film thicknesses. On the other hand, when the film thickness is 1250 Å, 1400 Å, or 1550 Å, such a sharp change is not observed in the reflectance, and a sufficient value is obtained for the reflectance.

  As can be seen from FIG. 14, when the film thickness is 1200 Å, the reflectance decreases from 0.882 to 0.848 by about 3.4% while the wavelength changes from 560 to 660 nm. When the film thickness is 2000 angstroms, the reflectance between wavelengths of 560 to 610 nm is considerably lower than in the case of other film thicknesses. On the other hand, when the film thickness is 1400 angstroms, 1600 angstroms, or 1800 angstroms, such a rapid change is not observed in the reflectance, and a sufficient value of the reflectance is obtained.

  12 to 14, the thickness of the silicon oxide film serving as a passivation film is set to a range of 900 to 1200 angstroms in the pixel electrode that reflects blue light, and the thickness of the silicon oxide film is set to 1200 to 1600 angstroms in the pixel electrode that reflects green light. By setting each of the pixel electrodes to reflect red light in a range such as 1300 to 1900 angstroms, the variation in reflectance for each color is suppressed to 1% or less, and the reflectance is also a sufficient value. Is obtained.

  Each graph shown in FIGS. 12 to 14 shows the reflectance when an alignment film made of polyimide is formed on the passivation film to a thickness of 1100 angstroms. If the thickness of the alignment film is different, the optimum range of the thickness of the silicon oxide film is slightly different from the above range. In addition, from the viewpoint of reducing the variation in the refractive index of the reflectance, the alignment film loses its alignment ability when the alignment film is lower than 300 Å, and when the thickness is more than 1400 Å, the polyimide has a low wavelength. It is preferable to set the wavelength in the range of 300 to 1400 angstroms because it absorbs high-wavelength light and the polyimide cannot be ignored as a capacitance component connected in series with the liquid crystal capacitance in the equivalent circuit. However, if there is a concern that the alignment ability will decrease as the alignment film becomes thinner, the thickness is preferably in the range of 800 to 1400 angstroms.

  If the thickness of the alignment film is within the above range, the thickness of the silicon oxide film of the liquid crystal panel for each color is set to the above range, which is enough to suppress the variation in the reflectance of the reflective electrode to 1% or less. It is.

  Therefore, when color display is performed by one liquid crystal panel, the passivation film on the reflective electrode can be made different for each color pixel according to the color of the pixel. That is, an RGB color filter corresponding to the pixel electrode is formed on the inner surface of the opposing substrate facing the reflection side substrate, and a red (R) color filter is formed in a configuration in which color light passing through this filter is reflected by the pixel electrode. For the pixel electrode that reflects red light through the pixel electrode, the thickness of the passivation film formed on the pixel electrode ranges from 1300 to 1900 angstroms, and the pixel electrode that reflects green light through the green (G) color filter. The thickness of the passivation film formed thereon is in the range of 1200 to 1600 angstroms, and for the pixel electrode that reflects blue light through the blue (B) color filter, the film of the passivation film formed thereon When the thickness is in the range of 900 to 1200 angstroms, a single-plate reflective liquid crystal with high reflectivity It is possible to configure the channel. The liquid crystal panel can also be used as a light valve of a single-panel projection display device. Note that, instead of using a color filter, color light may be configured by replacing light incident on each pixel electrode with color light (for example, a dichroic mirror).

  Furthermore, the liquid crystal panel of the present invention can also be used when each of the liquid crystal panel has a liquid crystal panel that reflects red light, a liquid crystal panel that reflects green light, and a liquid crystal panel that reflects blue light, as in a projection display device described later. it can. In that case, the thickness of the silicon oxide film serving as a passivation film in the light valve liquid crystal panel that modulates red light is in the range of 1300 to 1900 angstroms, and the passivation film is also used in the light valve liquid crystal panel that modulates green light. The thickness of the silicon oxide film is preferably in the range of 1200 to 1600 angstroms, and the thickness of the silicon oxide film serving as the passivation film in the light valve liquid crystal panel for modulating blue light is preferably in the range of 900 to 1200 angstroms. .

  FIG. 3 is a plan layout diagram of the liquid crystal panel substrate on the reflection side shown in FIG. As shown in the figure, in this embodiment, the data line 7 and the gate line 4 are formed so as to cross each other. Since the gate line 4 is configured to also serve as the gate electrode 4a, the portion of the gate line 4 indicated by hatching H in FIG. 3 becomes the gate electrode 4a, and the channel region 5c of the pixel switching MOSFET is formed on the substrate surface below the gate line 4a. Is provided. Source and drain regions 5a and 5b are formed on the substrate surface on both sides (up and down in FIG. 3) of the channel region 5c. The source electrode 7a connected to the data line is formed so as to protrude from the data line 7 extending along the vertical direction in FIG. 3, and is connected to the source region 5a of the MOSFET via the contact hole 6b. Have been.

  Further, the P-type doping region 8 constituting one terminal of the storage capacitor is formed so as to be continuous with the P-type doping region of the adjacent pixel in a direction parallel to the gate line 4 (pixel row direction). The power supply line 70 is connected to a power supply line 70 provided outside the pixel region through a contact hole 71, and is configured to apply a predetermined voltage Vss such as 0 V (ground potential). The predetermined voltage Vss is a potential at or near the potential of the common electrode disposed on the counter substrate, a potential at or near the center potential of the amplitude of the image signal supplied to the data line, or a potential between the common electrode and the image signal. May be any of the intermediate potentials of the amplitude center potentials.

  By connecting the P-type doping region 8 to the voltage Vss in common outside the pixel region, the potential of one electrode of the storage capacitor is stabilized, and the storage capacitor is held during the non-selection period of the pixel (when the MOSFET is not conducting). This makes it possible to stabilize the held potential and reduce the fluctuation of the potential applied to the pixel electrode during one frame period. Further, since the P-type doping region 8 is provided near the MOSFET and the potential of the P-type well is fixed at the same time, the substrate potential of the MOSFET can be stabilized and the threshold voltage can be prevented from changing due to the back gate effect.

  Although not shown, the power supply line 70 may be a line for supplying a predetermined voltage Vss as a well potential to a P-type well region (separated from the well of the pixel region) of a peripheral circuit provided outside the pixel region. It is used. The power supply line 70 is formed of the same metal layer as the data line 7.

  Each of the pixel electrodes 14 has a rectangular shape, and is provided close to each other with an interval of, for example, 1 μm between adjacent pixel electrodes 14 so as to minimize the amount of light leaking from a gap between the pixel electrodes. It is configured. Also, in the figure, the center of the pixel electrode and the center of the contact hole 16 are shifted, but it is preferable that the centers of the two are substantially matched or overlapped. The reason is that the second metal layer 12 having a light-shielding function is opened at 12a around the contact hole 16, so that if there is an opening 12a near the end of the pixel electrode 14, the gap between the pixel electrodes will increase. This is because the incident light is irregularly reflected between the second metal layer 12 and the back surface of the pixel electrode 14, reaches the opening 12a, enters the lower substrate side from the opening, and causes light leakage. . Therefore, by making the center of the pixel electrode substantially coincide with or overlap the center of the contact hole 16, the distance from the end of each pixel electrode until the light entering from the gap between the adjacent pixel electrodes reaches the contact hole is almost uniform. It is preferable because light can hardly reach a contact hole where light may enter the substrate side.

In the above embodiment, the case where the pixel switching MOSFET is an N-channel type, and the semiconductor region 8 serving as one electrode of the storage capacitor is a P-type doping layer has been described. The switching MOSFET may be a P-channel type, and the semiconductor region serving as one electrode of the storage capacitor may be an N-type doping layer. In this case, it is preferable that a predetermined potential VDD is applied to the N-type doping layer serving as one electrode of the storage capacitor in the same manner as applied to the N-type well region. Since the predetermined constant potential VDD applies a potential to the N-type well region, it is preferable that the predetermined constant potential be a higher potential of the power supply voltage.
That is, if the voltage of the image signal applied to the source / drain of the pixel switching MOSFET is 5V, it is preferable that the predetermined constant potential VDD is also 5V.

  Further, a large voltage such as 15V is applied to the gate electrode 4a of the MOSFET for pixel switching, whereas a logic circuit such as a shift register of a peripheral circuit is driven by a small voltage such as 5V ( A part of the peripheral circuit, for example, a circuit for supplying a scanning signal to the gate line is driven at 15 V. Therefore, the gate insulating film of the FET constituting the peripheral circuit operating at 5 V is replaced with the gate insulating film of the pixel switching FET. Thinner than that (by forming the gate insulating film in a separate process or by etching the surface of the gate insulating film of the peripheral circuit FET) to improve the response characteristics of the peripheral circuit FET and A technique for increasing the operation speed of a circuit (particularly, a shift register of a data line side driving circuit which requires high-speed scanning) is considered. When such a technique is applied, the thickness of the gate insulating film of the FET constituting the peripheral circuit is reduced to about one third to one fifth of the thickness of the gate insulating film of the pixel switching FET from the withstand voltage of the gate insulating film. (For example, 80 to 200 angstroms).

  Incidentally, the driving waveform in the first embodiment is as shown in FIG. In the figure, VG is a scanning signal applied to the gate electrode of the pixel switching MOSFET, a period tH1 is a selection period (scanning period) in which the MOSFET of the pixel is turned on, and the other period is a period in which the MOSFET of the pixel is turned off. This is a non-selection period during which conduction occurs. Vd is the maximum amplitude of the image signal applied to the data line, Vc is the central potential of the image signal, and LC-COM is applied to the opposing (common) electrode formed on the opposing substrate facing the reflective electrode side substrate. This is a common potential.

  The voltage applied between the electrodes of the storage capacitor is determined by the difference between the image signal voltage Vd applied to the data line as shown in FIG. 8 and a predetermined voltage Vss such as 0 V applied to the P-type semiconductor region 8. . However, the potential difference that should be originally applied to the storage capacitor is about 5 V which is the difference between the image signal voltage Vd and the center potential Vc of the image signal (applied to the opposing (common) electrode 33 provided on the opposing substrate 35 of the liquid crystal panel in FIG. 6). The common potential LC-COM is shifted by ΔV from Vc, but the voltage actually applied to the pixel electrode also becomes Vd−ΔV shifted by ΔV. Therefore, in the first embodiment, the doping region 8 constituting one terminal of the storage capacitor has the opposite polarity to the well (N-type in the case of a P-type well), and Vc or LC-COM is formed around the pixel region. A potential different from the well potential (for example, Vss for a P-type well) can be used by connecting to a nearby potential. Thereby, the insulating film 9b immediately below the polysilicon or metal silicide layer forming the one electrode 9a of the storage capacitor is formed simultaneously with the gate insulating film of the FET constituting the peripheral circuit, not the gate insulating film of the pixel switching FET. Thus, the insulating film thickness of the storage capacitor can be reduced to 1/3 to 1/5 as compared with the above embodiment, whereby the capacitance value can be increased 3 to 5 times.

FIG. 1B is a diagram showing a cross section (FIG. 3II-II) of a peripheral portion of a pixel region according to an embodiment of the present invention. The configuration of a portion that connects the doping region 8 extending in the scanning direction (pixel row direction) of the pixel region to a predetermined potential ( _VSS ) is shown. Reference numeral 80 denotes a P-type contact region formed in the same step as the source / drain region of the MOSFET of the peripheral circuit. The same conductivity type impurity is ion-implanted into the doping region 8 formed before the formation of the gate electrode. Formed. The contact region 80 is connected to the wiring 70 via the contact hole 71, and a constant voltage V _SS is applied. The contact region 80 is also shielded from light by the light-shielding layer 14 'made of a third metal layer.

  Next, FIG. 2 is a sectional view of an embodiment of a CMOS circuit element constituting a peripheral circuit such as a driving circuit outside the pixel region. In FIG. 2, the same reference numerals as in FIG. 1 denote metal layers, insulating films, and semiconductor regions formed in the same step.

In FIG. 2, reference numerals 4a and 4a 'denote gate electrodes of N-channel MOSFETs and P-channel MOSFETs constituting peripheral circuits (CMOS circuits) such as a drive circuit, and 5a (5b) and 5a' (5b ') denote their sources (drain). The N-type doping region and the P-type doping regions 5c and 5c 'which are regions are channel regions, respectively. The contact region 80 for supplying the constant potential V _SS to the P-type doping region 8 forming one electrode of the storage capacitor in FIG. 1 is a P-type doping region 5a ′ that becomes a source (drain) region of the P-channel MOSFET. It is formed in the same step as (5b '). Reference numerals 27a and 27c denote source electrodes composed of the first metal layer and connected to the power supply voltage (either 0 V, 5V or 15V), and reference numeral 27b denotes a drain electrode composed of the first metal layer. Reference numeral 32a is a wiring layer formed of a second metal layer, and is used as a wiring connecting elements constituting a peripheral circuit. 32b is a power supply wiring layer made of a second metal layer, but also functions as a light shielding layer. The light-shielding layer 32b may be connected to any of Vc, LC-COM, and a constant voltage such as a power supply voltage of 0 V, or may have an indefinite potential. Reference numeral 14 'denotes a third metal layer. In the peripheral circuit portion, the third metal layer is used as a light-shielding layer, and light passes through a semiconductor region constituting the peripheral circuit to generate carriers. This prevents the potential in the semiconductor region from becoming unstable and the peripheral circuit from malfunctioning. That is, the peripheral circuit is also shielded from light by the second and third metal layers.

  As described above, the passivation film 17 in the peripheral circuit portion is formed of a silicon nitride film which is more excellent as a protective film than the silicon oxide film forming the passivation film of the pixel region, or a silicon nitride film formed on the silicon oxide film. What is necessary is just to comprise as a protective film of a layer structure. Although not particularly limited, the source / drain regions of the MOSFET constituting the peripheral circuit of this embodiment may be formed by a self-alignment technique. Further, the source / drain regions of any MOSFET may have an LDD (lightly doped drain) structure or a DDD (double doped drain) structure. Note that the pixel switching FET may be offset (a structure in which a distance is provided between the gate electrode and the source / drain region) in consideration of being driven at a large voltage and having to prevent a leak current. .

  FIG. 4 shows a preferred embodiment as the structure of the end portion of the reflective electrode (pixel electrode) side substrate. 4, the portions denoted by the same reference numerals as those in FIGS. 1 and 2 indicate layers and semiconductor regions formed in the same step.

  As shown in FIG. 4, the end of the stacked body of the interlayer insulating film and the metal layer and the side wall thereof are covered with a silicon nitride film 18 on a passivation film 17 made of a silicon oxide film covering a pixel region and peripheral circuits. The laminated protective structure is formed. As described above, this end portion is formed by forming a large number of substrates of the present invention on a silicon wafer, and then dicing along a scribe line to separate each substrate (semiconductor chip) from each other. Part. That is, the lower part of the step portion on the right side in FIG. 4 is a scribe area.

  Therefore, since the silicon nitride film is used as a protective film on the upper part and the side wall part of the substrate edge, it becomes difficult for water or the like to enter from the edge part, thereby improving the durability, and the edge part is reinforced. improves. Further, in this embodiment, a sealing material 36 for sealing the liquid crystal is provided on the laminated protective structure portion which is completely flattened. Since a sealing material 36 is arranged on the passivation film having a laminated structure of the silicon oxide film 17 and the silicon nitride film 18 and the sealing member 36 is disposed on the passivation film, a pressure unit is used when the pair of substrates are sealed and bonded during liquid crystal panel assembly. Can be reinforced by a two-layer passivation film. In addition, the distance from the counter substrate can be kept constant irrespective of the variation in thickness due to the presence or absence of the interlayer insulating film and the metal layer. In addition, according to the above structure, the protective film on the reflective electrode serving as the pixel electrode can be formed as a single layer of a silicon oxide film without using silicon nitride. Can be reduced. The material of the passivation film is properly used according to the purpose. Further, the interlayer insulating film 13 can be configured as a two-layer structure of a silicon oxide film and a silicon nitride film as described later. The silicon nitride film has good moisture resistance and can further prevent entry of moisture from the edge of the substrate.

  As shown in FIG. 4, in this embodiment, the third metal layer 14 'is the same layer as the light shielding layer 14 in the peripheral circuit area or the reflective electrode 14 of the pixel. The potential is fixed at a predetermined potential via the first and second metal layers 12 'and 7'. Of course, instead of the third metal layer 14 ′, the second metal layer 12 ′ or the first metal layer 7 ′ may be extended below the sealing material 36 and used as a potential fixing layer. . This makes it possible to take measures against static electricity or the like during the formation of the liquid crystal panel substrate, during the formation of the liquid crystal panel, or after the formation of the liquid crystal panel.

  Note that the light-shielding layer 14 'in FIGS. 1B, 2, and 4 may be in a floating state where no potential is applied. With no potential applied, no voltage is applied to the liquid crystal in the light shielding layer 14 'surrounding the pixel region. Thereby, there is an advantage that an erroneous display is not generated around the pixel area.

  FIG. 5 shows another embodiment of the present invention. FIG. 5 is a cross-sectional view taken along line II in the planar layout of FIG. 3, as in FIG. In FIG. 5, the portions denoted by the same reference numerals as those in FIGS. 1 and 2 indicate layers and semiconductor regions formed by the same processes as those in the embodiments of these drawings. This embodiment is different from the above-described interlayer insulating film 13a made of the TEOS film (including the SOG film partially etched) between the reflective electrode 14 and the metal layer as the light shielding layer 12 thereunder. And a silicon nitride film 13b formed thereunder. Conversely, the silicon nitride film 13b may be formed on the TEOS film 13a. By using a two-layered interlayer insulating film structure to which a silicon nitride film is added as described above, it is difficult for water or the like to enter, and moisture resistance is improved. Although FIG. 5 is a cross-sectional view of the pixel region, the second metal layer is also formed at the position corresponding to the peripheral circuit shown in FIG. 2 and the end of the substrate shown in FIG. By using the same interlayer insulating film structure as the interlayer insulating film 13 formed thereon, the moisture resistance in the peripheral region can be improved. In particular, since the peripheral portion and the end portion of the substrate are regions into which moisture easily enters, the improvement of the moisture resistance in the periphery is greatly advantageous.

  The thickness of the passivation film on the reflective electrode is the same as in the embodiment of FIG.

  FIG. 16 shows another embodiment of the present invention. FIG. 16 is a cross-sectional view along the line II in the planar layout of FIG. 3, as in FIG. In FIG. 16, the portions denoted by the same reference numerals as those in FIGS. 1 and 2 indicate layers and semiconductor regions formed by the same processes as those in the embodiments of these drawings. This embodiment is different from the above-described interlayer insulating film 13a made of the TEOS film (including the SOG film partially etched) between the reflective electrode 14 and the metal layer as the light shielding layer 12 thereunder. The silicon nitride film 13b is formed thereon. In this case, the silicon nitride film 13a can be planarized by a CMP method or the like. In the case where the silicon nitride film is formed in this manner, since the openings in the silicon nitride portion are smaller than those in the embodiment shown in FIG. 5, water and the like are more difficult to enter and the moisture resistance is improved. At the same time, the protective insulating film 17 and the silicon nitride 13b are formed between the reflective electrode 14 and the adjacent reflective electrode. Since the refractive index of the silicon nitride film is 1.9 to 2.2, which is higher than the refractive index of the silicon oxide film used for the protective insulating film 17, which is 1.4 to 1.6, light is applied to the protective insulating film 17 from the liquid crystal side. At the time of incidence, the incident light is reflected at the interface with the silicon nitride film 13b due to the difference in refractive index. As a result, the incidence of light on the interlayer film is reduced, so that it is possible to prevent the light from passing through the semiconductor region and generating carriers, thereby preventing the potential in the semiconductor region from becoming unstable.

In this embodiment, the silicon nitride film 13b may be formed after the interlayer insulating film 13a made of a TEOS film is planarized by a CMP method or the like. In general, for example, in the CMP method or the like, it is necessary to deposit a film having a local step difference, for example, a film of 8000 to 12000 angstroms in order to eliminate a local step. Further, the silicon nitride film generally used for 13b has a stronger stress on the lower film as the film thickness increases. In this embodiment, the interlayer insulating film 13a is planarized by polishing by a CMP method or the like, and furthermore, a silicon nitride film 13b is formed thereon to reduce the thickness of the silicon nitride film 13b deposited by the CMP method or the like. It is possible to relax the stress of the silicon nitride film 13b. Also in this case, since the protective insulating film 17 and the silicon nitride 13b are formed between the reflective electrode 14 and the adjacent reflective electrode, the incidence of light on the interlayer film is reduced. And the potential in the semiconductor region can be prevented from becoming unstable. In this embodiment, for example, it is desirable that the thickness of the silicon nitride film 13b be 2000 to 5000 Å.
This is because the moisture resistance of the silicon nitride film 13b is improved by setting it to 2000 Å or more, and the etching depth of the contact hole 16 is reduced by making it 5000 nm or less to facilitate the etching. This is for reducing the stress on the lower film by reducing the thickness of the film.

  The thickness of the passivation film on the reflective electrode is the same as in the embodiment of FIG. FIG. 16 is a cross-sectional view of the pixel region. In the configuration of this embodiment, the peripheral circuit shown in FIG. 2 and the portion corresponding to the edge of the substrate shown in FIG. By using the same interlayer insulating film structure as the interlayer insulating film 13 formed in the above, the moisture resistance in the peripheral region can be improved. In particular, since the peripheral portion and the end portion of the substrate are regions into which moisture easily enters, the improvement of the moisture resistance in the periphery is greatly advantageous.

  FIG. 6 shows an overall planar layout configuration of a liquid crystal panel substrate (reflective electrode side substrate) to which the above embodiment is applied.

  As shown in FIG. 6, in this embodiment, a light-shielding layer 25 for preventing light from entering a peripheral circuit provided on the peripheral portion of the substrate is provided. This light shielding layer is formed by the same layer as the pixel electrode 14. The peripheral circuit is provided around a pixel region 20 in which the pixel electrodes are arranged in a matrix, and sequentially includes a data line driving circuit 21 and a gate line 4 that supply an image signal corresponding to image data to the data line 7. A gate line driving circuit 22 for scanning, an input circuit 23 for taking in image data input from the outside via a pad area 26, a timing control circuit 24 for controlling these circuits, and the like. A MOSFET formed in the same step or a different step from the MOSFET for use is used as an active element or a switching element, and is combined with a load element such as a resistor or a capacitor.

  In this embodiment, the light-shielding layer 25 is constituted by a third metal layer formed in the same step as the pixel electrode 14 shown in FIG. It is configured such that a predetermined potential such as the potential LC-COM is applied. By applying a predetermined potential to the light shielding layer 25, reflection can be reduced as compared with the case where the potential is floating or another potential. Further, the light-shielding layer 25 can be floated without being connected to the power supply wiring. With this configuration, no potential is applied to the liquid crystal layer by the light-shielding layer 25, so that an erroneous display in the peripheral region does not occur.

  Reference numeral 26 denotes a pad region in which pads or terminals used to supply a power supply voltage are formed. The position where the sealing material is provided is set so that the pad region 26 for inputting a signal from outside is located outside the sealing material 36.

  FIG. 7 shows a sectional configuration of a reflection type liquid crystal panel to which the liquid crystal panel substrate 31 is applied. As shown in FIG. 7, a support substrate 32 made of glass, ceramic, or the like is adhered to the back surface of the liquid crystal panel substrate 31 with an adhesive. At the same time, on the front surface side, an incident side glass substrate 35 having a counter electrode (also referred to as a common electrode) 33 made of a transparent conductive film (ITO) to which a common potential LC-COM is applied is provided at an appropriate interval. A well-known TN (Twisted Nematic) type liquid crystal or an SH (Super Homeotropic) type liquid crystal 37 in which liquid crystal molecules are substantially vertically aligned in a state where no voltage is applied in a gap disposed and sealed around with a sealing material 36. Are filled to form a liquid crystal panel 30.

  The light-shielding layer 25 on the peripheral circuit is configured to face the counter electrode 33 with the liquid crystal 37 interposed therebetween. When the LC common potential is applied to the light shielding layer 25, the LC common potential is applied to the counter electrode 33, so that no DC voltage is applied to the liquid crystal interposed therebetween. Therefore, in the case of the TN type liquid crystal, the liquid crystal molecules are always kept twisted by about 90 °, and in the case of the SH type liquid crystal, the liquid crystal molecules are always kept in a vertically aligned state.

  In this embodiment, the strength of the liquid crystal panel substrate 31 made of a semiconductor substrate is significantly increased because a support substrate 32 made of glass, ceramic, or the like is bonded to the back surface thereof with an adhesive. As a result, if the support substrate 32 is bonded to the liquid crystal panel substrate 31 and then bonded to the counter substrate, there is an advantage that the gap of the liquid crystal layer becomes uniform over the entire panel.

(Explanation of liquid crystal panel substrate using insulating substrate)
In the above description, the configuration of the reflective liquid crystal panel substrate using the semiconductor substrate and the liquid crystal panel using the same have been described. Hereinafter, the configuration of the reflective liquid crystal panel substrate using the insulating substrate will be described.

  FIG. 17 is a cross-sectional view showing a configuration of a pixel of a reflective liquid crystal panel substrate. This figure shows a cross-sectional view along line II in the plan layout diagram of FIG. 3, as in FIG. In this embodiment, a TFT is used as a pixel switching transistor. In FIG. 17, the portions denoted by the same reference numerals as those in FIGS. 1 and 2 indicate layers and semiconductor regions having the same functions as those in FIGS. Reference numeral 1 denotes a quartz or non-alkali glass substrate on which a monocrystalline, polycrystalline, or amorphous silicon film (layers of 5a, 5b, 5c, 8) is formed. Insulating films 4b and 9b having a two-layer structure of a silicon oxide film formed by thermal oxidation and a silicon nitride deposited by a CVD method are formed. Before the formation of the silicon nitride film as the upper layer of the insulating film 4b, regions 5a, 5b and 8 of the silicon film are doped with N-type impurities, so that the source region 5a, the drain region 5b of the TFT and the electrodes of the storage capacitor are formed. Region 8 is formed. Further, on the insulating film 4b, a wiring layer such as polysilicon or metal silicide to be the gate electrode 4a of the TFT and the other electrode 9a of the storage capacitor is formed. As described above, a TFT including the gate electrode 4a, the gate insulating film 4b, the channel 5c, the source 5a, and the drain 5b, and a storage capacitor including the electrodes 8, 9 and the insulating film 9b are formed.

A first interlayer insulating film 6 made of silicon nitride or silicon oxide is formed on wiring layers 4a and 9a, and a source connected to source region 5a via a contact hole formed in insulating film 6 is formed. The electrode 7a is formed by a first metal layer made of an aluminum layer. A second interlayer insulating film 13 formed of a silicon nitride film or a two-layer structure of a silicon oxide film and a silicon nitride film is further formed on the first metal layer. The structure of the interlayer insulating film 13 is preferably a double-layered interlayer insulating film shown as 13 in FIGS. By doing so, it is possible to obtain the same effect such as moisture resistance as described with reference to FIGS. The second interlayer insulating film 13 is planarized by a CMP method, and a pixel electrode serving as a reflective electrode made of aluminum is formed on each of the pixels. Note that the electrode region 8 of the silicon film and the pixel electrode 14 are electrically connected via the contact hole 16.
This connection is performed by burying a connection plug 15 made of a refractory metal such as tungsten in the same manner as in FIG.

  As described above, since the reflective electrode is formed above the TFT and the storage capacitor formed on the insulating substrate, the pixel electrode region is widened, and the storage capacitor is formed under the reflective electrode similarly to the plan layout diagram of FIG. Because it can be formed with a large area, not only a high definition (small pixels) panel can obtain a high aperture ratio (reflectance), but also a sufficient holding of the applied voltage in each pixel. Drive is stabilized.

  Further, as in the previous embodiments, a passivation film 17 made of a silicon oxide film is formed on the reflective electrode 14. The thickness of the passivation film 17 is the same as that of the embodiments described above, and it is possible to obtain a reflective liquid crystal panel substrate in which the change in reflectance is small according to the wavelength of incident light. The overall configuration of the liquid crystal panel substrate and the configuration of the liquid crystal panel are the same as those in FIGS.

In FIG. 17, the interlayer insulating film 11 and the light-shielding layer 12 are not arranged as shown in FIG. 1. However, in order to prevent light leakage of the TFT due to light incident from the gap between the adjacent pixel electrodes 14, these are removed. The layers may be arranged as in FIG. Further, if light incidence from below the substrate is also assumed, a light-shielding layer may be further arranged below the silicon films 5a, 5b, 8. Further, in the figure, the gate electrode is a top gate type in which the gate electrode is located above the channel. However, the gate electrode is formed first, and a bottom gate type in which a silicon film serving as a channel is disposed over a gate insulating film. Good.
Furthermore, when a two-layered interlayer insulating film such as the interlayer insulating film 13 described with reference to FIGS. 5 and 16 is disposed in the peripheral circuit region and the substrate edge, the peripheral region and the substrate edge where moisture easily enters are provided. Can be improved in moisture resistance.

(Description of Electronic Equipment Using Reflective Liquid Crystal Panel of the Present Invention)
FIG. 9 is an example of an electronic apparatus using the liquid crystal panel of the present invention, and is a schematic plan view of a main part of a projector (projection display device) using the reflective liquid crystal panel of the present invention as a light valve. FIG. FIG. 9 is a cross-sectional view in the XZ plane passing through the center of the optical element 130. The projector according to the present embodiment includes a light source unit 110 (111 is a lamp, 112 is a reflector), an integrator lens 120, and a polarization illuminating device 100, which are generally constituted by a light source unit 110 (111 is a reflector, a 112 is a reflector) arranged along the system optical axis L. A polarizing beam splitter 200 that reflects the S-polarized light beam emitted from the S-polarized light beam reflecting surface 201, and separates the blue light (B) component from the light reflected from the S-polarized light reflecting surface 201 of the polarizing beam splitter 200. A dichroic mirror 412, a reflective liquid crystal light valve 300B that modulates the separated blue light (B) into blue light, and a dichroic that reflects and separates the red light (R) component of the light flux after the blue light is separated. Mirror 413, reflective liquid crystal light valve 300R for modulating the separated red light (R), dichroic light The light modulated by the reflective liquid crystal light valves 300G, 300R, 300G, and 300B that modulate the remaining green light (G) transmitted through the light mirror 413 is converted into dichroic mirrors 412, 413, and a polarization beam splitter. The projection optical system 500 is composed of a projection lens that combines the light at 200 and projects the synthesized light on the screen 600. The above-described liquid crystal panel is used for each of the three reflective liquid crystal light valves 300R, 300G, and 300B.

  After 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, the polarization direction is almost uniform by the polarization conversion element 130 having the second integrator lens on the light incident side. After being converted into various types of polarized light beams (S-polarized light beams), the light reaches the polarizing beam splitter 200. The S-polarized light beam emitted from the polarization conversion element 130 is reflected by the S-polarized light beam reflecting surface 201 of the polarizing beam splitter 200, and among the reflected light beams, the blue light (B) is reflected by the dichroic mirror 412. The light is reflected by the layer and is modulated by the reflective liquid crystal light valve 300B. Further, among the light beams transmitted through the blue light reflecting layer of the dichroic mirror 411, 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 light flux of the green light (G) transmitted through the red light reflecting layer of the dichroic mirror 413 is modulated by the reflective liquid crystal light valve 300G. In this way, the color lights modulated by the respective reflective liquid crystal light valves 300R, 300G, 300B are combined by the dichroic mirrors 412, 413, and the polarization beam splitter 200, and the combined light is projected by the projection optical system 500. You.

  The reflection type liquid crystal panels to be the reflection type liquid crystal light valves 300R, 300G, and 300B are TN type liquid crystal (liquid crystal in which the long axes of liquid crystal molecules are aligned substantially parallel to the panel substrate when no voltage is applied) or SH type liquid crystal ( (A liquid crystal in which the major axis of the liquid crystal molecules is aligned substantially perpendicular to the panel substrate when no voltage is applied).

  When a TN type liquid crystal is adopted, in a pixel (OFF pixel) in which 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. The incident color light is elliptically polarized by the liquid crystal layer, reflected by the reflective electrode, and reflected via the liquid crystal layer as light in a state close to elliptically polarized light, which has a polarization axis component substantially deviated by 90 degrees from the polarization axis of the incident color light.・ Emitted. On the other hand, in a pixel (ON pixel) to which a voltage is applied to the liquid crystal layer, 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. Since the alignment angle of the liquid crystal molecules of the TN 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 adopted, in the pixel (OFF pixel) in which the applied voltage of the liquid crystal layer is equal to or lower than the threshold voltage of the liquid crystal, the incident color light reaches the reflective electrode as it is, and is reflected. The light is reflected and emitted with the same polarization axis. 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. Are 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, the alignment angle of the liquid crystal molecules of the SH type liquid crystal changes in accordance with the voltage applied to the reflective electrode. Therefore, the angle of the polarization axis of the reflected light with respect to the incident light passes through the transistor of the pixel. Variable according to the voltage applied to the reflective electrode.

  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, when the TN type liquid crystal is used for the liquid crystal panel, the reflected image 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 performed. Is used, the reflected light of the OFF pixel does not reach the projection optical system and the reflected light of the ON pixel reaches the projection optical system 500, so that a normally black display is obtained.

  The reflection type liquid crystal panel has a larger pixel electrode than the transmission type active matrix type liquid crystal panel, so that a high reflectance can be obtained, a high-definition image can be projected with high contrast, and the projector can be downsized.

As described with reference to FIG. 7, the peripheral circuit portion of the liquid crystal panel is covered with the light shielding layer, and has the same potential (for example, an LC common potential) together with the counter electrode formed at a position facing the counter substrate.
However, when the potential is not the LC common potential, the potential is different from that of the counter electrode of the pixel portion. In this case, the peripheral counter electrode is separated from the counter electrode of the pixel portion. ) Is applied, almost 0 V is applied to the liquid crystal interposed between them, and the liquid crystal 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.

  Silicon oxide forming a passivation film of a light valve 300R as a first reflective liquid crystal panel that modulates red light separated by a polarizing beam splitter 200 as a color separating unit as a color separating unit that splits light of the light source 110 into three primary color lights. The thickness of the film is in the range of 1300 to 1900 angstroms, and the thickness of the silicon oxide film forming the passivation film of the light valve 300G as the second reflective liquid crystal panel for modulating green light is in the range of 1200 to 1600 angstroms. More desirable results can be obtained if the thickness of the silicon oxide film forming the passivation film of the light valve 300B as the third reflective liquid crystal panel that modulates blue light is in the range of 900 to 1200 angstroms.

  According to the above embodiment, the voltages applied to the respective pixel electrodes of the reflective liquid crystal panels 300R, 300G, and 300B are sufficiently maintained, and a clear image is obtained because the reflectance of the pixel electrodes is extremely high.

  FIG. 15 is an external view showing an example of an electronic device using the reflective 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 used not 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. 15A is a perspective view showing a mobile phone. Reference numeral 1000 denotes a mobile phone main body, of which 1001 is a liquid crystal display unit using the reflective liquid crystal panel of the present invention.
FIG. 15B is a diagram illustrating a wristwatch-type electronic device. Reference numeral 1100 is a perspective view showing the watch main body. Reference numeral 1101 denotes a liquid crystal display unit using the reflective 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. 15C is a diagram illustrating a portable information processing device such as a word processor or a personal computer. Reference numeral 1200 denotes an information processing apparatus; 1202, an input unit such as a keyboard; 1206, a display unit using the reflective liquid crystal panel of the present invention; 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 is significantly reduced, and the weight and size can be further reduced.

  In the above embodiments, the TN type liquid crystal and the homeotropic SH type liquid crystal have been described as the liquid crystal of the liquid crystal panel. However, it is needless to say that the present invention can be implemented by replacing with another liquid crystal.

  As described above, according to the present invention, it is possible to provide a highly reliable reflective liquid crystal panel substrate and a liquid crystal panel having a passivation film whose reflectance does not vary greatly.

  Further, by using the silicon nitride film, a reflective liquid crystal panel substrate having moisture resistance can be provided.

  Further, it is possible to provide a reflective liquid crystal panel having high reliability and excellent image quality, and an electronic apparatus and a projection display device using the same.

FIG. 2 is a sectional view showing a first embodiment of a pixel region of a reflective electrode side substrate of a reflective liquid crystal panel to which the present invention is applied. FIG. 2 is a cross-sectional view illustrating an example of a structure of a peripheral circuit of a reflective electrode side substrate of a reflective liquid crystal panel to which the present invention is applied. FIG. 2 is a plan layout diagram of a first embodiment of a pixel region of a reflective electrode side substrate of a reflective liquid crystal panel to which the present invention is applied. FIG. 2 is a cross-sectional view showing an example of an end structure of a reflective electrode side substrate of a reflective liquid crystal panel to which the present invention is applied. FIG. 9 is a cross-sectional view showing another embodiment of the reflective electrode side substrate of the reflective liquid crystal panel to which the present invention is applied. FIG. 3 is a plan view showing a layout configuration example of a reflective electrode side substrate of the liquid crystal panel of the embodiment. FIG. 2 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. 4 is a waveform chart showing an example of a gate drive waveform and a data line drive waveform of a pixel electrode switching FET of a reflection type liquid crystal panel to which the present invention is applied. FIG. 1 is a schematic configuration diagram of a projector as an example of a projection display device in which a reflective liquid crystal panel of an embodiment is applied as a light valve. 9 is a graph showing the results of examining how the reflectance of a reflective electrode made of an aluminum layer changes with the thickness of a silicon oxide film at each wavelength in the incident direction. 9 is a graph showing a result of examining how the reflectance of a reflective electrode made of an aluminum layer changes with the thickness of a silicon oxide film at each wavelength of incident light. 7 is a graph in which the reflectance when the thickness of the silicon oxide film is changed in a wavelength range centered on blue is plotted for each appropriate wavelength. 7 is a graph in which the reflectance when the thickness of the silicon oxide film is changed in a wavelength range centered on green is plotted for each appropriate wavelength. 7 is a graph in which the reflectance when the thickness of the silicon oxide film is changed in a wavelength range centered on red is plotted for each appropriate wavelength. (A), (b), and (c) are external views each showing an example of an electronic device using the reflective liquid crystal panel of the present invention. FIG. 9 is a cross-sectional view showing another embodiment of the reflective electrode side substrate of the reflective liquid crystal panel to which the present invention is applied. FIG. 9 is a cross-sectional view showing another embodiment of the reflective electrode side substrate of the reflective liquid crystal panel to which the present invention is applied.

Explanation of reference numerals

Reference Signs List 1 semiconductor substrate 2 well region 3 field oxide film 4 gate line 4a gate electrode 5a, 5b source / drain region 6 first interlayer insulating film 7 data line (first metal layer)
7a Source electrode 8 P-type doping region 9a Storage capacitor electrode (conductive layer)
9b Insulating film serving as dielectric of storage capacitor 10 Auxiliary coupling wiring 11 Second interlayer insulating film 12 Light shielding layer (second metal layer)
13 Third interlayer insulating film 14 Pixel electrode (third metal layer)
Reference Signs List 15 connection plug 16 contact hole 17 passivation film 20 pixel region 21 data line drive circuit 22 gate line drive circuit 23 input circuit 24 timing control circuit 25 light shielding layer (third metal layer)
26 Pad Area 31 Liquid Crystal Panel Substrate 32 Support Substrate 33 Counter Electrode 35 Incident-side Glass Substrate 36 Sealing Material 37 Liquid Crystal 70 Power Line 71 Contact Hole 80 P-Type Contact Area 110 Light Source 200 Polarizing Beam Splitter 300 Light Valve (Reflective Liquid Crystal Panel) )
412,413 Dichroic mirror 500 Projection optical system 600 Screen

Claims (23)

  In a liquid crystal panel substrate, a reflective electrode is formed in a matrix on a substrate and a transistor is formed corresponding to each reflective electrode, and a voltage is applied to the reflective electrode via the transistor. A substrate for a liquid crystal panel, wherein a passivation film is formed on the reflective electrode.   2. The passivation film according to claim 1, wherein the thickness of the passivation film is selected so that the change in the reflectance of the reflective electrode with respect to the wavelength of the incident light is within about 1%. The substrate for a liquid crystal panel according to the above.   3. The liquid crystal panel substrate according to claim 1, wherein the passivation film is formed of silicon oxide.   3. The liquid crystal panel substrate according to claim 1, wherein the passivation film is a silicon oxide film having a thickness of 500 to 2,000 angstroms.   The liquid crystal panel substrate according to claim 1, wherein the thickness of the passivation film is set to an appropriate range in accordance with a wavelength of incident light.   5. The method according to claim 1, wherein when the reflective electrode reflects blue light, the thickness of the silicon oxide film serving as the passivation film formed on the reflective electrode is 900 to 1200 Å. 6. LCD panel substrate.   5. The method according to claim 1, wherein when the reflective electrode reflects green light, the thickness of the silicon oxide film serving as the passivation film formed on the reflective electrode is 1200 to 1600 Å. 6. LCD panel substrate.   5. The method according to claim 1, wherein when the reflective electrode reflects red light, the thickness of the silicon oxide film serving as the passivation film formed on the reflective electrode is 1300 to 1900 Å. 6. LCD panel substrate.   The liquid crystal panel substrate according to any one of claims 3 to 8, wherein an alignment film having a thickness of 300 to 1400 angstroms is formed on the silicon oxide film.   10. The liquid crystal panel substrate according to claim 1, wherein an interlayer insulating film made of silicon nitride is formed between the reflective electrode and a metal layer therebelow.   An interlayer insulating film between the reflective electrode and a metal layer therebelow is formed of a silicon nitride film and a silicon oxide film, and has a laminated structure in which the silicon nitride film is formed on the silicon oxide film. The liquid crystal panel substrate according to any one of claims 1 to 10, wherein:   The thickness of the passivation film on the reflective electrode that reflects red light is 1300 to 1900 angstroms, the thickness of the passivation film on the reflective electrode that reflects green light is 1200 to 1600 angstroms, and the blue light is reflected. The liquid crystal panel substrate according to any one of claims 1 to 11, wherein the thickness of the reflection electrode is 900 to 1200 angstroms.   In a liquid crystal panel substrate configured such that reflective electrodes are formed in a matrix on a substrate and transistors are formed corresponding to the respective reflective electrodes, and a voltage is applied to the reflective electrodes via the transistors. A substrate for a liquid crystal panel, wherein a passivation film made of silicon nitride is formed in an end region of the substrate.   14. The liquid crystal panel substrate according to claim 13, wherein the passivation film has a laminated structure of a silicon oxide film and a silicon nitride film formed on the silicon oxide film. A liquid crystal in which reflective electrodes are formed in a matrix on a substrate and transistors are respectively formed corresponding to the reflective electrodes, and each pixel unit is configured such that a voltage is applied to the reflective electrodes via the transistors In the panel substrate,
A liquid crystal panel, wherein a passivation film made of silicon oxide is formed above a pixel region in which the pixel unit is formed, and a passivation film made of silicon nitride is formed above a peripheral region of the pixel region. Substrate.   The passivation film having a laminated structure of the silicon oxide and the silicon nitride formed on the silicon oxide film is formed at least in a seal region of the peripheral region where the liquid crystal panel substrate and the counter substrate are bonded. The liquid crystal panel substrate according to claim 15, wherein the substrate is formed. A liquid crystal in which reflective electrodes are formed in a matrix on a substrate and transistors are respectively formed corresponding to the reflective electrodes, and each pixel unit is configured such that a voltage is applied to the reflective electrodes via the transistors In the panel substrate,
A substrate for a liquid crystal panel, wherein an interlayer insulating film having a stacked structure of a silicon oxide film and a silicon nitride film is formed between the reflective electrode and a conductive layer below the reflective electrode.   A light-shielding layer of the same layer as the reflective electrode is formed above a peripheral circuit region of a pixel region in which the pixel unit is formed, and a stacked structure of the silicon oxide film and the silicon nitride film below the light-shielding layer. 18. The substrate for a liquid crystal panel according to claim 17, wherein an interlayer insulating film is formed.   The interlayer insulating film is formed of the silicon nitride film formed on the silicon oxide film, and the silicon nitride film has a contact for connecting the pixel electrode and the lower conductive layer in a region of the pixel electrode. 18. The liquid crystal panel substrate according to claim 17, wherein only the hole is opened.   The liquid crystal panel substrate according to any one of claims 1 to 19, and a substrate on a light incident side are arranged to face each other with a gap, and liquid crystal is sealed in the gap. LCD panel.   An electronic apparatus comprising the liquid crystal panel according to claim 20 as a display unit.   21. A projection display device comprising: a light source; a liquid crystal panel according to claim 20, which modulates light from the light source; and projection optical means for projecting light modulated by the liquid crystal panel. A color separating unit that splits the light of the light source into three color lights, a first liquid crystal panel that modulates red light separated by the color separating unit, and a green light that is separated by the color separating unit. A second liquid crystal panel; and a third liquid crystal panel that modulates blue light separated by the color separation unit. The thickness of a silicon oxide film forming a passivation film of the first liquid crystal panel is A silicon oxide film forming a passivation film of the third liquid crystal panel; a silicon oxide film forming a passivation film of the second liquid crystal panel having a thickness in a range of 1300 to 1900 angstroms; 23. The projection type display device according to claim 22, wherein the film thickness of the film is in a range of 900 to 1200 angstroms.

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