JP2019008099A - Electro-optical device and electronic apparatus - Google Patents

Abstract

To provide an electro-optical device that prevents the occurrence of luminance unevenness due to the wavelength of incident light, and an electronic apparatus including the electro-optical device.SOLUTION: A liquid crystal device 100 as an electro-optical device comprises: a translucent substrate 10s; a translucent pixel electrode 16 that is provided for every pixel on the substrate 10s; a TFT 30 as a transistor that is a switching element of the pixel electrode 16; and a storage capacitance 31 that is connected to the TFT 30. The storage capacitance 31 includes a translucent capacitance electrode 15 that is arranged opposite to the pixel electrode 16 with a dielectric layer 14 therebetween; the refractive indices of the pixel electrode 16, dielectric layer 14, and capacitance electrode 15 are substantially the same, and the total value d of their film thicknesses satisfies the following formula (1). (1) d=λ/2n, where λ is the wavelength of light, and n is the refractive index of the pixel electrode 16.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an electro-optical device and an electronic apparatus.

  As an electro-optical device, an active drive type liquid crystal device including a switching element in a pixel can be given. The active drive type liquid crystal device has a storage capacitor for holding the potential of the image signal supplied to the pixel electrode. Increasing the number of pixels while reducing the pixel size to enable high-definition display affects not only the arrangement of the switching elements but also the arrangement of the storage capacitors. The electric capacity of the storage capacitor is determined by the area of the pair of electrodes arranged with the dielectric layer interposed therebetween, the distance between the pair of electrodes, and the dielectric constant of the dielectric layer. If the storage capacity is reduced in proportion to the size of the pixel, the electrical capacity may be reduced and it may be difficult to maintain the potential of the image signal. If the potential of the image signal is not held during the period when the pixel display is turned on by the switching element, display unevenness such as flicker occurs.

  As means for improving the problems associated with such a storage capacitor, for example, in Patent Document 1, a pixel electrode provided for each pixel, a transistor as a switching element, a hafnium oxide film, and an aluminum oxide film are alternately arranged. An electro-optical device including a storage capacitor having a stacked dielectric layer is disclosed. In addition, the dielectric layer films disposed on the first electrode side and the second electrode side of the storage capacitor are assumed to be hafnium oxide films. By stacking a hafnium oxide film having a large dielectric constant and an aluminum oxide film having a small leakage current, a storage capacitor having a large capacity and a low leakage current can be realized. Further, an example is shown in which the first electrode and the second electrode sandwiching the dielectric layer are made of indium oxide, which is a light-transmitting conductive material, and the storage capacitor is arranged in the opening region. Thereby, the area of the non-opening region can be reduced and the area of the opening region can be increased to further improve the light utilization efficiency.

JP 2014-142485 A

  Patent Document 1 discloses an example in which an electro-optical device is used as a light modulation means (light valve) of a projection display device (projector). However, when a storage capacitor having translucency is provided in the opening region as described above and a solid light source such as a laser light source or an LED having high monochromaticity is used as the light source of the projection display device, the dielectric of the storage capacitor Since the layers are in a state in which dielectric films having different refractive indexes are laminated, there is a problem that luminance unevenness occurs due to interference of light transmitted through the storage capacitor arranged in the opening region.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example] An electro-optical device according to this application example includes a translucent base material, a translucent pixel electrode provided for each pixel on the base material, and a transistor that is a switching element of the pixel electrode. And a storage capacitor connected to the transistor, the storage capacitor including a translucent capacitor electrode disposed opposite to the pixel electrode via a dielectric layer, the pixel electrode and the dielectric An electro-optical device in which the refractive indexes of the layer and the capacitive electrode are substantially equal, and the total value d of the respective film thicknesses satisfies the following formula (1).
d = λ / 2n (1)
λ is the wavelength of light, and n is the refractive index of the pixel electrode.

  According to this application example, since it is difficult for interference to occur even if light passes through the light-transmitting storage capacitor, an unevenness in luminance due to the interference of the light is not noticeable, and an electro-optical device having excellent display quality is provided. Can be provided.

In the electro-optical device according to the application example described above, provided on the base material, at least one of an interlayer insulating film provided between the transistor and the storage capacitor, and an upper side and a lower side of the storage capacitor. And a translucent insulating film having a refractive index between the refractive index of the capacitor electrode and the refractive index of the interlayer insulating film.
According to this configuration, reflection of light caused by a difference in refractive index between the capacitor electrode and the interlayer insulating film or a difference in refractive index between the pixel electrode and the electro-optic element disposed on the pixel electrode is suppressed, and uneven brightness is more conspicuous. It becomes difficult.

In the electro-optical device according to the application example, the insulating film may be provided above the storage capacitor.
According to this configuration, it is possible to suppress light reflection caused by a difference in refractive index between the pixel electrode and the electro-optic element disposed on the pixel electrode.

In the electro-optical device according to the application example, it is preferable that the insulating film is provided on an upper side and a lower side of the storage capacitor.
According to this configuration, the reflection of light caused by the difference in refractive index between the capacitor electrode and the interlayer insulating film and the difference in refractive index between the pixel electrode and the electro-optic element disposed on the pixel electrode is suppressed, and uneven brightness is less noticeable. Become.

In the electro-optical device according to the application example, it is preferable that a surface of the insulating film in contact with the capacitor electrode is roughened.
According to this configuration, since the surface area of the insulating film in contact with the capacitor electrode can be increased, the adhesion of the capacitor electrode to the insulating film can be physically improved. In other words, even if the material has low adhesion to the capacitor electrode, the degree of freedom for selecting a suitable material optically or reliably is improved.

In the electro-optical device according to the application example described above, a liquid crystal layer as an electro-optical element, an alignment film that controls alignment of liquid crystal molecules in the liquid crystal layer, and the liquid crystal layer sandwiched between the pixel electrodes Provided on at least one of a translucent counter electrode, the liquid crystal layer side of the counter electrode, and a side opposite to the liquid crystal layer side of the counter electrode, and the refractive index of the alignment film and the refraction of the counter electrode And a light-transmitting other insulating film having a refractive index between the refractive index and the refractive index.
When the refractive index of the alignment film and the refractive index of the counter electrode are different, the light transmitted through the counter electrode may be reflected on the light incident side or the light exit side of the counter electrode.
According to this configuration, another light-transmitting insulating film having a refractive index between the refractive index of the alignment film and the refractive index of the counter electrode is provided on the light incident side or the emission side of the counter electrode. The above reflection can be suppressed, and the utilization efficiency of light incident on the liquid crystal layer can be improved.

[Application Example] An electronic apparatus according to this application example includes the electro-optical device according to the application example described above.
According to this application example, since the interference and reflection of light incident on the aperture region where the pixel electrode is provided are suppressed and the electro-optical device that provides excellent display quality is provided, a good-looking display is possible. An electronic device can be provided.

1 is a schematic plan view illustrating a configuration of a liquid crystal device according to a first embodiment. FIG. 2 is a schematic cross-sectional view showing the structure of the liquid crystal device along the line H-H ′ shown in FIG. 1. FIG. 2 is an equivalent circuit diagram illustrating an electrical configuration of the liquid crystal panel of the first embodiment. The schematic plan view which shows arrangement | positioning of a pixel. The schematic plan view which shows arrangement | positioning of a thin-film transistor. FIG. 6 is a schematic cross-sectional view showing the structure of an element substrate along the line A-A ′ in FIG. 5. FIG. 5 is a schematic cross-sectional view showing the structure of an element substrate along the line B-B ′ in FIG. 4. FIG. 3 is a schematic cross-sectional view illustrating a state of light that passes through pixels of a liquid crystal panel. FIG. 6 is a schematic cross-sectional view illustrating a pixel structure in a liquid crystal device according to a second embodiment. The table | surface which shows the optical structural example of the pixel in a comparative example and an Example. The graph which shows the spectral characteristic of the light which permeate | transmits the pixel of a comparative example. 3 is a graph showing spectral characteristics of light that passes through a pixel of Example 1; 6 is a graph showing the spectral characteristics of light that passes through a pixel of Example 2; 10 is a graph showing the spectral characteristics of light transmitted through a pixel of Example 3. 10 is a graph showing spectral characteristics of light that passes through a pixel of Example 4; 10 is a graph showing the spectral characteristics of light transmitted through a pixel of Example 5. 10 is a graph showing spectral characteristics of light that passes through a pixel of Example 6; 10 is a graph showing the spectral characteristics of light transmitted through a pixel of Example 7. The figure which shows the structure of the projection type display apparatus as an electronic device.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

  In the present embodiment, an active matrix liquid crystal device including a thin film transistor (TFT) as a pixel switching element will be described as an example of an electro-optical device. This liquid crystal device can be suitably used as, for example, a light modulation means (light valve) of a projection display device (projector) described later.

(First embodiment)
<Electro-optical device>
First, a liquid crystal device as an electro-optical device according to the present embodiment will be described with reference to FIGS. 1 is a schematic plan view showing the configuration of the liquid crystal device according to the first embodiment, FIG. 2 is a schematic cross-sectional view showing the structure of the liquid crystal device along the line HH ′ shown in FIG. 1, and FIG. It is an equivalent circuit diagram which shows the electrical structure of a liquid crystal panel.

  As shown in FIGS. 1 and 2, a liquid crystal device 100 as an electro-optical device according to this embodiment includes an element substrate 10 and a counter substrate 20 that are arranged to face each other, and an electro-optical element that is sandwiched between the pair of substrates. A liquid crystal layer 50. As the base material 10s of the element substrate 10 and the base material 20s of the counter substrate 20, for example, transparent quartz substrates or glass substrates are used, respectively.

The element substrate 10 is larger than the counter substrate 20, and the both substrates are bonded to each other with a seal portion 40 disposed along the outer edge of the counter substrate 20. An interrupted portion in the seal portion 40 is an injection port 41, and liquid crystal having positive or negative dielectric anisotropy is injected into the gap from the injection port 41 by a vacuum injection method and injected using a sealant 42. An inlet 41 is enclosed. Note that the method of encapsulating the liquid crystal in the interval is not limited to the vacuum injection method. For example, the liquid crystal is dropped inside the seal portion 40 arranged in a frame shape, and the element substrate 10 is removed under reduced pressure. An ODF (One Drop Fill) method in which the counter substrate 20 is bonded may be employed.
For the seal portion 40, for example, an adhesive such as a thermosetting or ultraviolet curable epoxy resin is employed. Spacers (not shown) are mixed in the seal portion 40 to keep the distance between the pair of substrates constant.

  A pixel region E including a plurality of pixels P arranged in a matrix is provided inside the seal portion 40. Further, a parting portion 21 that surrounds the pixel region E and functions as a light shielding layer is provided in a region between the seal portion 40 and the pixel region E. The parting portion 21 is made of, for example, a light shielding metal or metal oxide. The pixel region E may include a plurality of dummy pixels arranged along the outer edge of the pixel region E in addition to the pixels P that contribute to display.

  The element substrate 10 is provided with a terminal portion in which a plurality of external connection terminals 104 are arranged. A data line driving circuit 101 is provided between the first side portion along the terminal portion and the seal portion 40. Further, an inspection circuit 103 is provided between the seal portion 40 and the pixel region E along the second side that faces the first side. Further, a scanning line driving circuit 102 is provided between the seal portion 40 and the pixel region E along the third and fourth sides that are orthogonal to the first side and face each other. A plurality of wirings 105 that connect the two scanning line driving circuits 102 are provided between the seal part 40 on the second side and the inspection circuit 103.

Wirings connected to the data line driving circuit 101 and the scanning line driving circuit 102 are connected to a plurality of external connection terminals 104 arranged along the first side. Note that the arrangement of the inspection circuit 103 is not limited to this, and the inspection circuit 103 may be provided at a position along the inner side of the seal portion 40 between the data line driving circuit 101 and the pixel region E.
In the following description, the direction along the first side is defined as the X direction, and the direction along the third side is defined as the Y direction. Further, viewing along the direction from the counter substrate 20 side toward the element substrate 10 side is referred to as “plan view” or “planar”.

  As shown in FIG. 2, on the surface of the element substrate 10 on the liquid crystal layer 50 side, a transparent pixel electrode 16 provided for each pixel P and a thin film transistor (hereinafter referred to as TFT) 30 as a switching element. In addition, a signal wiring and an alignment film 18 covering these are formed. In addition, a light shielding structure is employed that prevents light from entering the semiconductor layer in the TFT 30 to make the switching operation unstable. The element substrate 10 includes a base material 10s, a pixel electrode 16, a TFT 30, a signal wiring, and an alignment film 18 formed on the base material 10s. The “translucency” in the present embodiment refers to a property having a transmittance of at least 85% in the visible light wavelength range.

  The counter substrate 20 disposed on the element substrate 10 via the liquid crystal layer 50 includes a base material 20s, a parting portion 21 formed on the base material 20s, and a planarization layer 22 formed so as to cover the part. The counter electrode 23 covers the planarization layer 22 and is provided over at least the pixel region E, and functions as a common electrode. The alignment film 24 covers the counter electrode 23.

  The parting part 21 surrounds the pixel region E as shown in FIG. 1 and is provided at a position overlapping the scanning line driving circuit 102 and the inspection circuit 103 in plan view. This serves to shield the light incident on these circuits from the counter substrate 20 side and prevent these circuits from malfunctioning due to the light. Further, unnecessary stray light is shielded from entering the pixel region E to ensure high contrast in the display of the pixel region E.

  The planarization layer 22 is made of an inorganic material such as silicon oxide, for example, and is provided so as to cover the parting portion 21 with light transmittance. As a method for forming such a planarizing layer 22, for example, a method of forming a film using a plasma CVD method or the like can be given.

  The counter electrode 23 is made of a transparent conductive film such as ITO (Indium Tin Oxide), for example, covers the planarization layer 22, and as shown in FIG. 1, the vertical conductive portion 106 provided at the lower corner of the counter substrate 20 is provided. Is electrically connected. The vertical conduction part 106 is electrically connected to the wiring on the element substrate 10 side.

  The alignment film 18 covering the pixel electrode 16 and the alignment film 24 covering the counter electrode 23 are selected based on the optical design of the liquid crystal device 100. The alignment films 18 and 24 are organic materials in which a substantially horizontal alignment process is performed on liquid crystal molecules having positive dielectric anisotropy, for example, by forming an organic material such as polyimide and rubbing the surface thereof. Examples thereof include an alignment film and an inorganic alignment film formed by depositing an inorganic material such as SiOx (silicon oxide) using a vapor phase growth method so that the liquid crystal molecules have a negative dielectric anisotropy and are substantially perpendicularly aligned. .

Such a liquid crystal device 100 is a transmissive type, and is normally white mode in which the transmittance of the pixel P is maximized when no voltage is applied, or normally black in which the transmittance of the pixel P is minimized when no voltage is applied. Modal optical design is adopted. Polarizing elements are arranged and used according to the optical design respectively on the light incident side and the light exit side of the liquid crystal panel 110 including the element substrate 10 and the counter substrate 20.
In the present embodiment, an example in which a normally black mode optical design is applied using the inorganic alignment film described above as the alignment films 18 and 24 and a liquid crystal having negative dielectric anisotropy will be described.

  Next, an electrical configuration of the liquid crystal panel 110 in the liquid crystal device 100 will be described with reference to FIG. The liquid crystal panel 110 includes a plurality of scanning lines 3a and a plurality of data lines 6a as signal wirings that are insulated and orthogonal to each other in the pixel region E, and capacitance lines 7a arranged in parallel along the data lines 6a. The direction in which the scanning line 3a extends is the X direction, and the direction in which the data line 6a extends is the Y direction.

  A pixel electrode 16, a TFT 30, and a storage capacitor 31 are provided in a region divided by the scanning line 3a, the data line 6a, the capacitor line 7a, and these signal lines, and these constitute a pixel circuit of the pixel P. doing.

  The scanning line 3 a is electrically connected to the gate of the TFT 30, and the data line 6 a is electrically connected to the source of the TFT 30. The pixel electrode 16 is electrically connected to the drain of the TFT 30.

  The data line 6a is connected to the data line driving circuit 101 (see FIG. 1), and supplies display signals D1, D2,..., Dn supplied from the data line driving circuit 101 to the pixels P. The scanning line 3a is connected to the scanning line driving circuit 102 (see FIG. 1), and supplies scanning signals SC1, SC2,..., SCm supplied from the scanning line driving circuit 102 to the pixels P.

  The display signals D1 to Dn supplied from the data line driving circuit 101 to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each of a plurality of adjacent data lines 6a for each group. Good. The scanning line driving circuit 102 supplies the scanning signals SC1 to SCm to the scanning line 3a in a pulse-sequential manner at a predetermined timing.

  In the liquid crystal device 100, the TFT 30 that is a switching element is turned on for a certain period by the input of the scanning signals SC1 to SCm, so that the display signals D1 to Dn supplied from the data line 6a are supplied to the pixel electrode 16 at a predetermined timing. It is the structure written in. Then, the display signals D1 to Dn of a predetermined level written in the liquid crystal layer 50 through the pixel electrode 16 are held for a certain period between the pixel electrode 16 and the counter electrode 23 arranged to face each other through the liquid crystal layer 50. The The frequency of the display signals D1 to Dn is 60 Hz, for example.

  In order to prevent the held display signals D1 to Dn from leaking, the storage capacitor 31 is connected in parallel with the liquid crystal capacitor formed between the pixel electrode 16 and the counter electrode 23. The storage capacitor 31 in the present embodiment is provided between the drain of the TFT 30 and the capacitor line 7a, and includes a translucent capacitor electrode disposed opposite to the pixel electrode 16 via a dielectric layer. ing. A detailed configuration of the storage capacitor 31 will be described later.

  The inspection circuit 103 shown in FIG. 1 is connected to the data line 6a and can detect an operation defect of the liquid crystal device 100 by detecting the display signal in the manufacturing process of the liquid crystal device 100. Although not shown in the equivalent circuit of FIG.

  Peripheral circuits that drive and control the pixel circuits in this embodiment include a data line driving circuit 101, a scanning line driving circuit 102, and an inspection circuit 103. The peripheral circuit samples the display signals D1 to Dn and supplies them to the data line 6a. The precharge circuit supplies a precharge signal of a predetermined voltage level to the data lines 6a prior to the display signals D1 to Dn. May be included.

  Next, the arrangement of the pixels P will be described with reference to FIG. FIG. 4 is a schematic plan view showing the arrangement of pixels. As shown in FIG. 4, the pixel P in the liquid crystal device 100 has, for example, a substantially quadrangular (substantially square) opening region in a plan view. The opening area is surrounded by a light-shielding non-opening area extending in the X direction and the Y direction and provided in a lattice shape.

  A scanning line 3a shown in FIG. 3 is provided in the non-opening region extending in the X direction. The scanning line 3a uses a light-shielding conductive member, and at least a part of the non-opening region is constituted by the scanning line 3a.

  Similarly, the data line 6a and the capacitor line 7a shown in FIG. 3 are provided in the non-opening region extending in the Y direction. The data line 6a and the capacitor line 7a also use light-shielding conductive members, and at least a part of the non-opening region is configured by these.

  The non-opening region may be formed not only by the signal lines provided on the element substrate 10 side, but also by a light shielding film patterned in a lattice shape on the counter substrate 20 side.

  The TFT 30 shown in FIG. 3 is provided near the intersection of the non-opening regions. By providing the TFT 30 in the vicinity of the intersection of the non-opening region having the light shielding property, the optical malfunction of the TFT 30 is prevented and the aperture ratio in the opening region is secured. Although the detailed structure of the pixel P will be described later, the width of the non-opening region in the vicinity of the intersecting portion is wider than that in other portions due to the provision of the TFT 30 near the intersecting portion.

  Next, each component such as a thin film transistor in the pixel circuit of the pixel P will be described with reference to FIGS. 5 is a schematic plan view showing the arrangement of the thin film transistors, FIG. 6 is a schematic cross-sectional view showing the structure of the element substrate along the line AA ′ in FIG. 5, and FIG. 7 is along the line BB ′ in FIG. It is a schematic sectional drawing which shows the structure of the element board | substrate which was.

  As shown in FIG. 5, the pixel P includes a TFT 30 provided at the intersection of the scanning line 3a and the data line 6a. The TFT 30 includes a first source / drain region 30s connected to the data line 6a, a channel region 30c, a second source / drain region 30d connected to the pixel electrode 16, a first source / drain region 30s and a channel region. A semiconductor layer 30a having an LDD (Lightly Doped Drain) structure having a junction region 30e provided between the channel region 30c and a junction region 30f provided between the channel region 30c and the second source / drain region 30d. doing. The semiconductor layer 30a is disposed so as to pass through the intersection and overlap the scanning line 3a.

  The scanning line 3a has a quadrangular extended portion in plan view extended from the main line portion in the X and Y directions at the intersection with the data line 6a. A gate electrode 30g having a shape that overlaps the extension portion in a plane and is bent so as to extend in the X direction and the Y direction is provided.

  In the gate electrode 30g, the portion extending in the Y direction overlaps the channel region 30c in a plane. Further, it has a portion that is bent from the portion overlapping the channel region 30c and extends in the X direction. The gate electrode 30g is electrically connected to the scanning line 3a by contact holes CNT3 and CNT4, which extend in the X direction along the semiconductor layer 30a and are provided between the extended portions of the scanning line 3a. Connected to.

  The contact holes CNT3 and CNT4 are rectangular (rectangular) having a long X direction in plan view, and are provided on both sides so as to sandwich the junction region 30f along the channel region 30c and the junction region 30f of the semiconductor layer 30a. Yes.

  The data line 6a extends in the Y direction and also has a rectangular extension at the intersection with the scanning line 3a, and is formed by a contact hole CNT1 provided in the protrusion 6c protruding from the extension in the X direction. The first source / drain region 30s is electrically connected. A portion including the contact hole CNT1 serves as a source electrode. On the other hand, a contact hole CNT2 is also provided at the end of the second source / drain region 30d, and a portion including the contact hole CNT2 serves as a drain electrode.

  Although not shown in FIG. 5, the capacitor line 7a shown in FIG. 3 extends in the Y direction so as to overlap the data line 6a in plan view. Similarly to the data line 6a, the capacitor line 7a is provided with an extended portion at the intersection with the scanning line 3a.

  Contact holes CNT5 and CNT7 are provided adjacent to the contact hole CNT2 in the extending direction (X direction) of the scanning line 3a. The contact hole CNT2 and the contact hole CNT5 are electrically connected via a first relay electrode 6b provided in an island shape. The contact hole CNT5 and the contact hole CNT7 are electrically connected through the second relay electrode 7b provided in the same island shape.

  The pixel electrode 16 is arranged so as to overlap the above-described opening region (see FIG. 4) in a plan view and the outer edge portion covers the non-opening region (see FIG. 4). The pixel electrode 16 is electrically connected to the second relay electrode 7b via the contact hole CNT7.

  As shown in FIG. 6, first, the scanning line 3 a is formed on the base material 10 s of the element substrate 10. The scanning line 3a also serves as a light-shielding film that shields the semiconductor layer 30a, and includes, for example, a simple metal, an alloy, a metal silicide, a polysilicide, including at least one of metals such as Ti, Cr, W, Ta, and Mo. A nitride or a laminate of these can be used, and has light shielding properties.

  A base insulating film 9 made of, for example, silicon oxide or the like is formed so as to cover the scanning line 3a, and a semiconductor layer 30a is formed on the base insulating film 9 in an island shape. The semiconductor layer 30a is made of, for example, a polycrystalline silicon film, and is implanted with impurity ions to have the first source / drain region 30s, the junction region 30e, the channel region 30c, the junction region 30f, and the second source / drain region 30d. An LDD structure is formed.

  A gate insulating film 11a made of, for example, silicon oxide is formed so as to cover the semiconductor layer 30a. Further, a gate electrode 30g is formed at a position facing the channel region 30c with the gate insulating film 11a interposed therebetween. The gate electrode 30g can be formed using, for example, a polycrystalline silicon film, and at the same time penetrates the base insulating film 9 and the gate insulating film 11a to electrically connect the scanning line 3a (extended portion) and the gate electrode 30g. Contact holes CNT3 and CNT4 (see FIG. 5) are also formed.

  A first interlayer insulating film 11b made of, for example, silicon oxide is formed so as to cover the gate electrode 30g and the gate insulating film 11a. A contact hole CNT1 is formed through the gate insulating film 11a and the first interlayer insulating film 11b, which overlaps the first source / drain region 30s of the semiconductor layer 30a. Similarly, a contact hole CNT2 penetrating through the gate insulating film 11a and the first interlayer insulating film 11b overlapping the second source / drain region 30d of the semiconductor layer 30a is formed. Subsequently, a conductive film made of a light-shielding metal such as Al is formed and patterned so as to cover the first interlayer insulating film 11b, whereby the first source / drain region 30s is electrically connected via the contact hole CNT1. Connected data lines 6a are formed. At the same time, the first relay electrode 6b electrically connected to the second source / drain region 30d through the contact hole CNT2 is formed.

  Subsequently, a second interlayer insulating film 12 is formed so as to cover the data line 6a and the first relay electrode 6b. The second interlayer insulating film 12 is made of, for example, silicon oxide, and is subjected to a flattening process for flattening surface irregularities caused by covering the region where the TFT 30 is provided. Examples of the planarization method include chemical mechanical polishing (CMP) and etching.

  A contact hole CNT5 penetrating the second interlayer insulating film 12 is formed at a position overlapping the first relay electrode 6b. A conductive film made of a light-shielding metal such as Al is formed so as to cover the contact hole CNT5 and cover the second interlayer insulating film 12, and is patterned to form the capacitor line 7a and the contact hole CNT5. And a second relay electrode 7b electrically connected to the first relay electrode 6b. As described above, the capacitor line 7a is formed so as to overlap the data line 6a in a plane and is given a fixed potential.

  A third interlayer insulating film 13a is formed so as to cover the capacitance line 7a and the second relay electrode 7b. The third interlayer insulating film 13a can also be formed using, for example, silicon oxide, and is subjected to a planarization process such as a CMP process. The third interlayer insulating film 13a is an example of an interlayer insulating film in the present invention.

Next, a first insulating film 13b is formed so as to cover the third interlayer insulating film 13a. The first insulating film 13b has a refractive index between the refractive index of the translucent capacitive electrode 15 formed later and the refractive index of the third interlayer insulating film 13a. In this embodiment, the first insulating film 13b is oxidized. An aluminum (Al ₂ O ₃ ) film is used.

  Next, a transparent conductive film such as ITO is formed so as to cover the first insulating film 13b, and the capacitor electrode 15 is formed by patterning the transparent conductive film. Although not shown in FIG. 6, the capacitor electrode 15 is electrically connected to the capacitor line 7a through a contact hole penetrating the first insulating film 13b and the third interlayer insulating film 13a.

Next, the second insulating film 13 c is formed so as to cover the outer edge of the capacitor electrode 15. Specifically, an insulating film made of, for example, silicon oxide is formed so as to cover the capacitive electrode 15, and the insulating film is patterned to form an opening in a portion overlapping the capacitive electrode 15, thereby forming the second insulating film. 13c is formed. Next, the dielectric layer 14 is formed so as to cover the capacitor electrode 15 and the second insulating film 13c. The dielectric layer 14 is formed by selecting a material so that the refractive index of the dielectric layer 14 is the same as the refractive index of the capacitor electrode 15 and the refractive index of the pixel electrode 16 to be formed later. In this embodiment, it is formed using hafnium oxide (HfO ₂ ).

  The film thickness of the dielectric layer 14 is determined in consideration of the electric capacity of the storage capacitor 31 and the light transmittance in the visible light wavelength range, and is, for example, 20 nm to 50 nm.

Next, a contact hole CNT7 penetrating through the dielectric layer 14, the second insulating film 13c, the first insulating film 13b, and the third interlayer insulating film 13a is formed at a position overlapping the second relay electrode 7b. Then, a transparent conductive film such as ITO is formed to cover the contact hole CNT7 and cover the dielectric layer 14, and by patterning this, the second relay electrode 7b is electrically connected to the contact hole CNT7 through the contact hole CNT7. A pixel electrode 16 to be connected is formed.
The pixel electrode 16 is planarly overlapped with the capacitor electrode 15, and a translucent storage capacitor 31 is formed for each pixel P by the pixel electrode 16, the dielectric layer 14, and the capacitor electrode 15.
As described above, since the dielectric layer 14 is a thin film, the capacitor electrode 15 and the pixel electrode 16 may be short-circuited when the film thickness is further reduced at the portion covering the outer edge of the capacitor electrode 15. In order to prevent this short circuit, a second insulating film 13 c that covers the outer edge of the capacitor electrode 15 is provided.

A third insulating film 17 is formed so as to cover the pixel electrode 16 and the dielectric layer 14. The third insulating film 17 has a refractive index between the refractive index of the alignment film 18 formed later and the refractive index of the pixel electrode 16, and in this embodiment, aluminum oxide (Al ₂ O ₃ ). A membrane is used.

  An alignment film 18 is formed so as to cover the third insulating film 17. The alignment film 18 covers the entire display area E and is composed of the above-described inorganic alignment film such as silicon oxide.

  According to such a wiring structure of the element substrate 10, the second source / drain region 30 d (drain electrode) of the TFT 30 includes the contact hole CNT 2, the first relay electrode 6 b, the contact hole CNT 5, the second relay electrode 7 b, and the contact hole. It is electrically connected to the pixel electrode 16 through the CNT 7.

  As shown in FIG. 7, in the element substrate 10, in the opening region of the pixel P, the base insulating film 9, the gate insulating film 11a, the first interlayer insulating film 11b, and the second interlayer insulating film are formed on the base material 10s. The film 12, the third interlayer insulating film 13a, the first insulating film 13b, the capacitor electrode 15, the dielectric layer 14, the pixel electrode 16, the third insulating film 17, and the alignment film 18 are sequentially stacked. Has been. These films and electrodes all have translucency. The capacitor electrode 15, the dielectric layer 14, and the pixel electrode 16 constitute a storage capacitor 31.

  As described above, the base insulating film 9, the gate insulating film 11a, the first interlayer insulating film 11b, the second interlayer insulating film 12, and the third interlayer insulating film 13a are made of, for example, silicon oxide (silicon oxide). It has almost the same refractive index (1.4 to 1.5 in the visible light wavelength range (400 nm to 750 nm)) as that of the constituent material of 10 s, for example, quartz. Since the refractive indexes are almost the same, visible light transmitted through these films hardly reflects or refracts at the interface of the films, so that the intensity (transmittance) of the light is hardly attenuated.

  In contrast, in the portion above the third interlayer insulating film 13a (the portion where the storage capacitor 31 is formed), the first insulating film 13b (with a refractive index of 1.6 to 1.7 in the visible light wavelength range (oxidized). Aluminum)), capacitive electrode 15 (if ITO, refractive index is 1.9 to 2.0 in the visible light wavelength range), and dielectric layer 14 (refractive index is 1.9 to 2.0 in the visible light wavelength range). (Hafnium oxide)), the pixel electrode 16 (if ITO, the refractive index is 1.9 to 2.0 in the visible light wavelength range), and the third insulating film 17 (the refractive index is 1.6 to 2.0 in the visible light wavelength range). 1.7 (aluminum oxide)) and an alignment film 18 (with a refractive index of 1.4 to 1.5 (silicon oxide) in the visible light wavelength range) are stacked. Part of the visible light transmitted through the substrate 10 is reflected at the interface between the films having different refractive indexes. Reflection (multiple reflection) of light occurs at the interface of films having different refractive indexes, and interference of light occurs between the reflected light and light transmitted through the storage capacitor 31. Further, the pixel electrode 16 and the capacitor electrode 15 are connected to each other. Transmission of light causes interference (multiple interference) and absorption of light, so that the transmittance of light transmitted through these films changes according to the refractive index and film thickness of these films.

  For example, depending on the wavelength of light transmitted through the storage capacitor 31, the light intensity may be attenuated due to light interference, and the transmittance of the light transmitted through the storage capacitor 31 may decrease. Further, depending on the wavelength of light transmitted through the storage capacitor 31, the light intensity may be amplified by light interference, and the transmittance of the light transmitted through the storage capacitor 31 may increase. In particular, when the liquid crystal device 100 is used as a light modulation means (light valve) of a projection display device (projector) to be described later, for each of red (R), green (G), and blue (B) color lights having different wavelengths. Since the light modulation means is arranged, the increase or decrease in the transmittance depending on the wavelength of light causes uneven brightness.

In the liquid crystal device 100 according to the present embodiment, the storage capacitor 31 includes a translucent capacitor electrode 15 disposed to face the pixel electrode 16 with the dielectric layer 14 in between, and the pixel electrode 16, the dielectric layer 14, and the capacitor electrode. The total refractive index d of the respective film thicknesses satisfies the following formula (1).
d = λ / 2n (1)
λ is the wavelength of light, and n is the refractive index of the pixel electrode 16 (or the capacitor electrode 15).

  Satisfying the above formula (1) is that the total value d of the film thicknesses of the capacitor electrode 15, the pixel electrode 16, and the dielectric layer 14 constituting the storage capacitor 31 represents the value of the wavelength λ of light as the refractive index. The value is divided by 2 times n, which is a condition in which light interference hardly occurs.

Specifically, since the refractive indexes of the pixel electrode 16, the dielectric layer 14, and the capacitive electrode 15 that constitute the storage capacitor 31 are substantially equal, if the refractive index of the pixel electrode 16 is n, the translucent storage capacitor 31. The refractive index of n is also n. The optical distance Lc of the translucent storage capacitor 31 can be expressed by the product of the refractive index and the film thickness. That is, Lc = n × d. Therefore, when the value of the optical distance Lc is an integral multiple of the wavelength λ, the light incident at the interface between the layers having different refractive indexes located on the upper side and the lower side of the storage capacitor 31 is resonated by the reflected light reflected. Will occur. On the other hand, when the optical distance Lc is ½ of the wavelength λ, the phase of the reflected light is shifted by a half cycle, so that the reflected light is most attenuated without causing resonance. Therefore, the above formula (1) is derived from the following formula (2).
n × d = λ / 2 (2)

  FIG. 8 is a schematic cross-sectional view showing a state of light transmitted through the pixels of the liquid crystal panel. In the present embodiment, the case where the light L1 enters the liquid crystal panel 110 from the counter substrate 20 side will be described as an example.

  As shown in FIG. 8, the light L <b> 1 incident from the counter substrate 20 side passes through the counter substrate 20 and the liquid crystal layer 50 and enters the element substrate 10. The storage capacitor 31 in the element substrate 10 has substantially the same refractive index in the pixel electrode 16, the dielectric layer 14, and the capacitor electrode 15, and the total thickness d (hereinafter referred to as the total thickness d of the storage capacitor 31). ) Satisfies the above mathematical expression (1), and therefore is a condition in which interference of light transmitted through the storage capacitor 31 is unlikely to occur. Therefore, if light L1 incident on the element substrate 10 is transmitted through the element substrate 10 and emitted is L2, and light (reflected light) generated by light interference in the storage capacitor 31 is L3, the reflected light L3 Therefore, the ratio of the intensity of the light L2 to the intensity of the light L1, that is, the transmittance is improved.

  In addition, a first insulating film 13b having a refractive index intermediate to the refractive indexes of these films is provided between the third interlayer insulating film 13a and the capacitive electrode 15 having different refractive indexes. Thereby, reflection of light at the interface between the third interlayer insulating film 13a and the capacitive electrode 15 having different refractive indexes disposed via the first insulating film 13b is suppressed. Similarly, a third insulating film 17 having an intermediate refractive index relative to the refractive index of these films is provided between the pixel electrode 16 and the alignment film 18 having different refractive indexes. Thereby, reflection of light at the interface between the pixel electrode 16 and the alignment film 18 having different refractive indexes disposed via the third insulating film 17 is suppressed. Note that the alignment films 18 and 24 that align the liquid crystal molecules in the liquid crystal layer 50 in a predetermined state are essential for the liquid crystal panel 110. Further, the refractive index of the liquid crystal layer 50 is smaller than the refractive index of the pixel electrode 16 using a transparent conductive film such as ITO, and larger than the refractive index of the alignment film 18 formed using an inorganic material such as silicon oxide. Or equivalent. Therefore, the third insulating film 17 has a refractive index between the refractive index of the pixel electrode 16 and the refractive index of the liquid crystal layer 50 as an electro-optical element.

According to the liquid crystal device 100 of the first embodiment, the following effects can be obtained.
(1) Each of the capacitor electrode 15, the dielectric layer 14, and the pixel electrode 16 constituting the storage capacitor 31 of the element substrate 10 is translucent, and the storage capacitor 31 is disposed in the opening region of the pixel P. . The refractive indexes of the pixel electrode 16, the dielectric layer 14, and the capacitor electrode 15 are substantially equal, and the total film thickness d of the storage capacitor 31 satisfies the formula (1) where d = λ / 2n. Accordingly, since it is difficult for interference to occur even if light passes through the light-transmitting storage capacitor 31, luminance unevenness due to the interference of the light is not noticeable, and the liquid crystal device 100 having excellent display quality is provided. Can do.

  (2) A light-transmitting first insulation provided on the lower side of the storage capacitor 31 on the substrate 10s and having a refractive index between the refractive index of the capacitive electrode 15 and the refractive index of the third interlayer insulating film 13a. A film 13 b and a translucent third insulating film 17 provided on the upper side of the storage capacitor 31 and having a refractive index between the refractive index of the alignment film 18 and the refractive index of the pixel electrode 16 are provided. Therefore, compared with the case where the first insulating film 13b is not provided, the reflection of light at the interface between the films having different refractive indexes is suppressed. That is, the light transmittance in the opening region of the element substrate 10 is further improved.

  (3) On the base material 10s, the first insulating film 13b provided below the storage capacitor 31 and the third insulating film 17 provided above the storage capacitor 31 are both formed using aluminum oxide. Therefore, the moisture permeability is lower than that of silicon oxide. Therefore, even when moisture enters the liquid crystal panel 110, the electrical circuit configuration provided on the element substrate 10 side is hardly affected by moisture, so that the liquid crystal device 100 having high reliability can be realized.

(Second Embodiment)
Next, as an electro-optical device according to the second embodiment, a liquid crystal device will be described as an example as in the first embodiment with reference to FIG. FIG. 9 is a schematic cross-sectional view illustrating a pixel structure in the liquid crystal device according to the second embodiment. The liquid crystal device of the second embodiment has basically the same configuration as that of the liquid crystal device 100 of the first embodiment, and is partially different in structure. Therefore, the same components as those of the liquid crystal device 100 are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 9 is a schematic cross-sectional view corresponding to FIG. 8 used in the description of the first embodiment, and illustrates the storage capacitor 31 arranged in the opening region of the pixel P and the configuration related thereto.

  As shown in FIG. 9, the liquid crystal device 200 of the second embodiment includes a liquid crystal panel 210 in which a liquid crystal layer 50 is sandwiched between an element substrate 10 </ b> B and a counter substrate 20. In contrast to the liquid crystal panel 110 in the liquid crystal device 100 of the first embodiment, the liquid crystal panel 210 of the present embodiment has the same configuration and structure as the counter substrate 20 but a structure of the element substrate 10B.

  Specifically, the element substrate 10B includes a third interlayer insulating film 13a, a first insulating film 13b, a capacitor electrode 15, a dielectric layer 14, a pixel electrode 16, a first electrode disposed on a light-transmitting base material 10s. Three insulating films 17 and an alignment film 18 are provided. As described above, the first insulating film 13b is formed using, for example, aluminum oxide. The capacitor electrode 15 is formed using, for example, ITO. The adhesion between the aluminum oxide film and the ITO film is weaker than the adhesion between the silicon oxide film and the ITO film.

  In the present embodiment, the surface 13d of the third interlayer insulating film 13a on the first insulating film 13b side is roughened. Accordingly, the surface 13e of the first insulating film 13b formed so as to cover the surface 13d is also roughened. Thereby, the substantial surface area of the first insulating film 13b is increased, and the adhesion between the first insulating film 13b and the capacitor electrode 15 having different material structures is improved. Examples of a method for roughening the surface 13d of the third interlayer insulating film 13a include methods such as polishing and etching. The degree of roughening is preferably about several to 10 nm in terms of arithmetic average roughness Ra, for example. When it becomes rougher than this, irregular reflection of light is likely to occur at the interface between the third interlayer insulating film 13a and the first insulating film 13b or at the interface between the first insulating film 13b and the capacitor electrode 15. The film thickness of the first insulating film 13b is smaller than the film thickness of the third interlayer insulating film 13a due to optical condition restrictions. Therefore, it is technically difficult to roughen the first insulating film 13b itself. It is easier to indirectly roughen the surface 13e of the first insulating film 13b by roughening the surface 13d of the third interlayer insulating film 13a.

  According to the liquid crystal device 200 of the second embodiment, by roughening the surface 13d of the third interlayer insulating film 13a, the surface 13e of the first insulating film 13b is indirectly roughened, and thus different material configurations. Adhesiveness between the first insulating film 13b made of and the capacitor electrode 15 is improved. As a result, the first insulating film 13b and the capacitor electrode 15 are less likely to be peeled off from the third interlayer insulating film 13a. In addition, when the first insulating film 13b is made of an aluminum oxide film, the moisture resistance can be further improved. That is, similar to the liquid crystal device 100 of the first embodiment, interference does not easily occur even if light is transmitted through the translucent storage capacitor 31, so that uneven brightness due to the interference of the light is not noticeable and excellent. The liquid crystal device 200 having high display quality and improved moisture resistance reliability as compared with the liquid crystal device 100 of the first embodiment can be provided.

  Next, regarding the optical configuration of the present invention including the translucent storage capacitor 31 in the opening region of the pixel P, more specific examples and comparative examples will be given, and the effects thereof will be described with reference to FIGS. Will be described with reference to FIG. FIG. 10 is a table showing an example of the optical configuration of the pixels in the comparative example and the example, and FIGS. 11 to 18 are graphs showing the spectral characteristics of light transmitted through the pixels of the comparative example and the examples 1 to 7. is there.

  First, the optical configuration of the pixel P of the liquid crystal panel in the comparative example and the first to seventh embodiments will be described with reference to FIG.

As shown in FIG. 10, as a common optical configuration of the liquid crystal panels in the comparative example and Examples 1 to 7, both the base material 10s of the element substrate 10 and the base material 20s of the counter substrate 20 are quartz. (Refractive index is 1.47). The liquid crystal layer 50 is composed of nematic liquid crystal having a negative dielectric anisotropy (refractive index is 1.55), and its layer thickness is 2400 nm (2.4 μm). The alignment film 18 of the element substrate 10 and the alignment film 24 of the counter substrate 20 sandwiching the liquid crystal layer 50 are both inorganic alignment films made of silicon oxide (SiO ₂ ; refractive index 1.42), and the film thicknesses are both 75 nm. It is. The capacitor electrode 15, the pixel electrode 16, and the counter electrode 23 are all made of ITO (refractive index is 2.00), and the film thickness is not necessarily constant, but varies depending on the optical conditions of the comparative example and the first to seventh embodiments.

(Comparative example)
In the liquid crystal panel of the comparative example, the translucent storage capacitor has a hafnium oxide film (HfO) having a thickness of 3 nm between the capacitor electrode 15 having a thickness of 20 nm and the pixel electrode 16 having a thickness of 80 nm. ₂ ; a refractive index of 2.00) and an aluminum oxide film (Al ₂ O ₃ ; a refractive index of 1.70) including five dielectric layers alternately laminated. The counter electrode 23 has a film thickness of 113 nm.

Example 1
The translucent storage capacitor 31 in the liquid crystal panel of Example 1 is different from the comparative example in the configuration of the storage capacitor 31, and is a capacitor electrode 15 having a thickness of 20 nm and a thickness of 65 nm. A dielectric layer 14 made of a hafnium oxide film having a thickness of 28 nm is provided between the pixel electrode 16 and the pixel electrode 16. The refractive indexes of the capacitor electrode 15, the dielectric layer 14, and the pixel electrode 16 are all 2.00, and the total film thickness d of the storage capacitor 31 is 113 nm. Therefore, when the wavelength λ is, for example, 452 nm of blue, Example 1 satisfies the above formula (1). Note that the thickness of the counter electrode 23 is 113 nm as in the comparative example. Other configurations are the same as those of the comparative example.

(Example 2)
The liquid crystal panel of Example 2 is different from that of Example 1 between the third interlayer insulating film 13 a and the capacitive electrode 15, and the refraction between the refractive index of the third interlayer insulating film 13 a and the refractive index of the capacitive electrode 15. A first insulating film 13b having a thickness of 67 nm made of an aluminum oxide film having a high rate is provided. Further, a third insulating film having a thickness of 67 nm, which is made of an aluminum oxide film having a refractive index between the refractive index of the alignment film 18 and the refractive index of the pixel electrode 16, is interposed between the pixel electrode 16 and the alignment film 18. 17 is provided. Since the optical configuration of the storage capacitor 31 is the same as that of the first embodiment, the above formula (1) is also satisfied. Note that the thickness of the counter electrode 23 is 113 nm as in the comparative example.

Example 3
The liquid crystal panel of Example 3 is opposite to the refractive index of the alignment film 24 on the upper side (base material 20s side) and lower side (alignment film 24 side) of the counter electrode 23 of the counter substrate 20 with respect to Example 2. An insulating film having a film thickness of 67 nm made of an aluminum oxide film having a refractive index between the refractive indexes of the electrodes 23 is provided. Since the optical configuration of the storage capacitor 31 is the same as that of the first embodiment, the above formula (1) is also satisfied. Note that the thickness of the counter electrode 23 is 113 nm as in the comparative example.

(Example 4)
The liquid crystal panel of Example 4 is different from Example 3 in that the first insulating film 13b made of an aluminum oxide film having a thickness of 67 nm between the third interlayer insulating film 13a and the capacitor electrode 15 is removed, and the counter substrate is used. The insulating film made of an aluminum oxide film having a thickness of 67 nm above the 20 counter electrodes 23 (base 20s side) is excluded. In other words, with respect to the first embodiment, the film thickness is made of an aluminum oxide film having a refractive index between the refractive index of the alignment film 18 and the refractive index of the pixel electrode 16 between the pixel electrode 16 and the alignment film 18. A third insulating film 17 having a thickness of 67 nm is provided, and an insulating film made of an aluminum oxide film having a thickness of 67 nm is provided between the counter electrode 23 and the alignment film 24. Since the optical configuration of the storage capacitor 31 is the same as that of the first embodiment, the above formula (1) is also satisfied. Note that the thickness of the counter electrode 23 is 113 nm as in the comparative example.

(Example 5)
The liquid crystal panel of the fifth embodiment is different from the third embodiment in that the third insulating film 17 made of an aluminum oxide film between the pixel electrode 16 and the alignment film 18 is removed, and between the counter electrode 23 and the alignment film 24. The insulating film made of the aluminum oxide film is removed. In other words, with respect to Example 1, the first insulating film 13b made of an aluminum oxide film having a thickness of 67 nm is provided between the third interlayer insulating film 13a and the capacitor electrode 15, and the upper side of the counter electrode 23 (base material) Similarly, an insulating film made of an aluminum oxide film having a thickness of 67 nm is provided on the 20s side). Since the optical configuration of the storage capacitor 31 is the same as that of the first embodiment, the above formula (1) is also satisfied. Note that the thickness of the counter electrode 23 is 113 nm as in the comparative example.

(Example 6)
In the liquid crystal panel of Example 6, the film thickness of the aluminum oxide film is changed from 67 nm to 83 nm, and the film thickness of the pixel electrode 16 in the storage capacitor 31 is changed from 65 nm to 90 nm. As a result, the total film thickness d of the storage capacitor 31 is 138 nm. If the wavelength λ of light incident on the storage capacitor 31 is 552 nm for green, the refractive index of the storage capacitor 31 is 2.00. Therefore, the optical configuration of the storage capacitor 31 of the sixth embodiment is expressed by the above formula (1). Is satisfied. That is, the optical configuration of the storage capacitor 31 in the first to fifth embodiments satisfies the above formula (1) with respect to blue light, but the sixth embodiment has the above formula (with respect to green light). It satisfies 1). The counter electrode 23 has a thickness of 138 nm.

(Example 7)
In the liquid crystal panel of Example 7, the film thickness of the aluminum oxide film is changed from 67 nm to 100 nm, and the film thickness of the pixel electrode 16 in the storage capacitor 31 is changed from 65 nm to 115 nm. As a result, the total film thickness d of the storage capacitor 31 is 163 nm. If the wavelength λ of light incident on the storage capacitor 31 is 652 nm in red, the refractive index of the storage capacitor 31 is 2.00. Therefore, the optical configuration of the storage capacitor 31 of Example 7 is expressed by the above formula (1). Is satisfied. That is, the optical configuration of the storage capacitor 31 in the first to fifth embodiments satisfies the above formula (1) with respect to blue light, but the seventh embodiment has the above formula (for the red light with the above formula (1). It satisfies 1). The counter electrode 23 has a thickness of 163 nm.

  The spectral characteristics of the light transmitted through the pixels of the comparative example and Examples 1 to 7 shown in FIGS. 11 to 18 are based on the optical configuration of the liquid crystal panels of the comparative example and Examples 1 to 7 described above. As described above, the transmittance of light transmitted through the pixel P is obtained using an optical simulation. Specifically, in the comparative example and Examples 1 to 7, the transmittance when the polarized light is incident and transmitted through the translucent substrate is 1.00 (that is, 100%), and the pixel of the liquid crystal panel The transmittance when P is transmitted is obtained.

  As shown in FIG. 11, in the spectral characteristics of the liquid crystal panel of the comparative example, the transmittance varies periodically in the visible light wavelength range (430 nm to 680 nm). Further, the longer the wavelength, the larger the variation range of the transmittance, and the longer the period of variation. This is because the storage capacitor of the comparative example uses a dielectric layer in which two types of dielectric films having different refractive indexes are alternately stacked, and therefore the degree of multiple reflection of light in the storage capacitor depends on the wavelength of incident light. This is due to fluctuations. When polarized light of blue light is incident on the liquid crystal panel of the comparative example, the attenuation of the color light due to the storage capacitor is small, but when the polarized light of green light or red light is incident, the degree of attenuation of the color light is large. It becomes darker.

  As shown in FIG. 12, the spectral characteristics of the liquid crystal panel of Example 1 are similar to the comparative example, in which the transmittance periodically varies in the visible light wavelength range (430 nm to 680 nm). The fluctuation range is smaller than that. In particular, the transmittance is hardly attenuated in the wavelength range of blue light. In other words, the transmittance is improved in the wavelength range of blue light compared to the comparative example.

  As shown in FIG. 13, the spectral characteristics of the liquid crystal panel of Example 2 have periodically changing transmittance as in Example 1. However, the transmittance fluctuation range is further increased compared to Example 1. It is getting smaller. In other words, by providing an insulating film made of aluminum oxide on the upper side and the lower side of the storage capacitor 31, reflection at the interface between the storage capacitor 31 and the insulating film is suppressed, and multiple reflection hardly occurs and the transmittance is improved. It is thought.

  As shown in FIG. 14, in the spectral characteristics of the liquid crystal panel of Example 3, the periodic variation of transmittance depending on the wavelength of light is further smaller than that of Example 2, and in the visible light wavelength range, A transmittance of approximately 0.98 (98%) or higher is realized. This is because by providing an insulating film made of aluminum oxide on the upper side and the lower side of the counter electrode 23, reflection at the interface between the counter electrode 23 and the insulating film is suppressed, and the transmittance of light transmitted through the pixel P is further increased. It is thought that it was improved.

  As shown in FIG. 15, the spectral characteristics of the liquid crystal panel of Example 4 have the transmittance periodically changing as in Example 1, but the transmittance fluctuation range is blue compared to Example 1. It becomes larger in the wavelength range of light, and is smaller in the wavelength range of green light and red light, which has a longer wavelength than blue light. The transmittance in the visible light wavelength range is approximately 0.9 (90%) or more.

  As shown in FIG. 16, in the spectral characteristics of the liquid crystal panel of Example 5, the transmittance fluctuates periodically similarly to Example 1, but the transmittance fluctuation range is blue compared to Example 1. It becomes larger in the wavelength range of light, and is smaller in the wavelength range of green light and red light, which has a longer wavelength than blue light. As in Example 4, the transmittance in the visible light wavelength range is approximately 0.9 (90%) or more. As can be seen from the spectral characteristics of the fourth and fifth embodiments, by disposing an insulating film made of aluminum oxide having a refractive index of 1.70 on either the upper side or the lower side of the storage capacitor 31, the storage capacitor 31. It is considered that the reflection at the interface with the insulating film is suppressed, the multiple reflection hardly occurs, and the transmittance is improved.

  As shown in FIG. 17, the spectral characteristics of the liquid crystal panel of Example 6 are almost the same as those of Example 3, but the transmittance slightly varies in the wavelength range of blue light and red light. doing. On the other hand, in the wavelength range of green light, variation in transmittance is suppressed, and a value close to 1.00 (100%) is shown. That is, the liquid crystal panel of Example 6 has an optical configuration suitable for incident green light.

  As shown in FIG. 18, the spectral characteristics of the liquid crystal panel of Example 7 are almost the same as those of Example 3, but the transmittance slightly varies in the wavelength range of blue light and green light. doing. On the other hand, in the wavelength range of red light, the variation in transmittance is suppressed, and a value close to 1.00 (100%) is shown. That is, the liquid crystal panel of Example 7 has an optical configuration suitable for the incidence of red light.

  In the comparative example and Examples 1 to 7 described above, the layer thickness of the liquid crystal layer 50 is constant at 2400 nm (2.4 μm). However, the layer thickness may actually vary during the manufacturing process of the liquid crystal panel 110. is there. Variation in the layer thickness (also referred to as cell thickness) of the liquid crystal layer 50 is an optical configuration in the pixel P, which is an interlayer insulating film, an insulating film, a light-transmitting storage capacitor 31 (capacitor electrode 15, dielectric layer 14, Since it is larger than the film thickness variations of the pixel electrode 16), the alignment film, and the counter electrode 23, the influence on the spectral characteristics is also increased. Therefore, it is preferable to use the liquid crystal panel 110 according to the third, sixth, and seventh embodiments where the spectral characteristics are flatter. That is, it is preferable to dispose an insulating film made of aluminum oxide not only on the upper and lower sides of the storage capacitor 31 but also on the upper and lower sides of the counter electrode 23.

(Third embodiment)
<Electronic equipment>
Next, as an electronic apparatus of this embodiment, a projection display device will be described as an example with reference to FIG. FIG. 19 is a diagram illustrating a configuration of a projection display device as an electronic apparatus.

  As shown in FIG. 19, a projection display apparatus 1000 as an electronic apparatus according to this embodiment includes a polarization illumination apparatus 1100 arranged along the system optical axis L, and two dichroic mirrors 1104 and 1105 as light separation elements. Three reflection mirrors 1106, 1107, 1108, five relay lenses 1201, 1202, 1203, 1204, 1205, three transmissive liquid crystal light valves 1210, 1220, 1230 as light modulation means, and a light combining element As a cross dichroic prism 1206 and a projection lens 1207.

  The polarized light illumination device 1100 is generally configured by a lamp unit 1101 as a light source composed of a white light source such as an ultra-high pressure mercury lamp or a halogen lamp, an integrator lens 1102, and a polarization conversion element 1103.

  The dichroic mirror 1104 reflects red light (R) and transmits green light (G) and blue light (B) among the polarized light beams emitted from the polarization illumination device 1100. Another dichroic mirror 1105 reflects the green light (G) transmitted through the dichroic mirror 1104 and transmits the blue light (B).

The red light (R) reflected by the dichroic mirror 1104 is reflected by the reflection mirror 1106 and then enters the liquid crystal light valve 1210 via the relay lens 1205.
Green light (G) reflected by the dichroic mirror 1105 enters the liquid crystal light valve 1220 via the relay lens 1204.
The blue light (B) transmitted through the dichroic mirror 1105 enters the liquid crystal light valve 1230 via a light guide system including three relay lenses 1201, 1202, 1203 and two reflection mirrors 1107, 1108.

  The liquid crystal light valves 1210, 1220, and 1230 are disposed to face the incident surfaces of the cross dichroic prism 1206 for each color light. The color light incident on the liquid crystal light valves 1210, 1220, and 1230 is modulated based on the video information (display data) and emitted toward the cross dichroic prism 1206. In this prism, four right-angle prisms are bonded together, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface thereof. The three color lights are synthesized by these dielectric multilayer films, and the light representing the color image is synthesized. The synthesized light is projected onto the screen 1300 by the projection lens 1207, which is a projection optical system, and the image is enlarged and displayed.

  The liquid crystal light valve 1210 is the one to which the liquid crystal device 100 of the first embodiment having the above-described ion trap mechanism is applied. A pair of polarizing elements arranged in crossed Nicols are arranged with a gap between the color light incident side and the emission side of the liquid crystal panel 110. The same applies to the other liquid crystal light valves 1220 and 1230.

  According to such a projection type display device 1000, the liquid crystal device 100 is used as the liquid crystal light valves 1210, 1220, and 1230. Therefore, the translucent storage capacitor 31 is provided in the opening region of the pixel P. The resulting luminance unevenness is suppressed. Since it is possible to easily secure the electric capacity necessary for holding the image signal while suppressing the luminance unevenness, it is possible to provide the projection display device 1000 having excellent display quality. The same effect can be obtained by using the liquid crystal device 200 of the second embodiment described above as the liquid crystal light valves 1210, 1220, and 1230.

  In the projection display apparatus 1000 of the present embodiment, a white light source such as an ultrahigh pressure mercury lamp or a halogen lamp is used, but the present invention is not limited to this. For example, you may provide solid light sources, such as a laser light source and LED corresponding to each of red light (R), green light (G), and blue light (B). The wavelength range of monochromatic light emitted from a laser light source or LED is narrower than in the case where light emitted from a white light source is dispersed by a dichroic mirror into color light. Even if such monochromatic light is incident on the above-described liquid crystal light valves 1210, 1220, and 1230, since the liquid crystal device 100 is used, uneven brightness hardly occurs. In particular, if the liquid crystal panel 110 of the liquid crystal device 100 has the optical configuration shown in the third, sixth, and seventh embodiments, red light (R), green light (G), and blue light (B ) With excellent spectral characteristics (transmittance characteristics) for each monochromatic light, it is possible to display brightly without uneven brightness.

  The present invention is not limited to the above-described embodiments, and various modifications can be made as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Electronic equipment to which the electro-optical device is applied is also included in the technical scope of the present invention. Various modifications other than the above embodiment are conceivable. Hereinafter, a modification will be described.

  (Modification 1) In the above embodiment, the dielectric layer 14 constituting the translucent storage capacitor 31 has a single-layer structure made of hafnium oxide. However, the optical refractive index is different from that of the capacitor electrode 15 and the pixel electrode 16. As long as they are substantially equal, the layer is not necessarily limited to a single layer. For example, a configuration may be adopted in which a low refractive index layer made of aluminum oxide or the like whose thickness is, for example, an order of magnitude thinner than that of the high refractive index layer is sandwiched between high refractive index layers made of hafnium oxide or the like.

  (Modification 2) The arrangement of various wirings and electrodes related to the TFT 30 and the TFT 30 on the base material 10s of the element substrate 10 is not limited to this. For example, the capacitor electrode 15 may be disposed over at least the display region E to have a function of the capacitor line 7a.

  (Modification 3) In the liquid crystal device 200 (liquid crystal panel 210) of the second embodiment, the surface 13e of the first insulating film 13b in contact with the capacitor electrode 15 is roughened, but the pixel electrode in contact with the third insulating film 17 is used. By roughening the surface of 16, the adhesion between the pixel electrode 16 and the third insulating film 17 can be improved.

  (Modification 4) The electronic apparatus to which the liquid crystal device 100 of the first embodiment or the liquid crystal device 200 of the second embodiment is applied is not limited to the projection display device 1000 of the third embodiment. For example, by providing a liquid crystal device with a color filter having a colored layer on a pixel, a projection-type HUD (head-up display), a direct-view HMD (head-mounted display), an electronic book, a personal computer, a digital still camera It can be suitably used as a display unit of information terminal devices such as liquid crystal televisions, viewfinder type or monitor direct view type video recorders, car navigation systems, electronic notebooks, and POSs.

  DESCRIPTION OF SYMBOLS 10 ... Element substrate, 10s ... Base material, 13a ... 3rd interlayer insulation film as interlayer insulation film, 13b ... 1st insulation film as translucent insulation film, 13e ... Surface of insulation film, 14 ... Dielectric layer 15 ... Capacitance electrode, 16 ... Pixel electrode, 17 ... Third insulating film as a translucent insulating film, 23 ... Counter electrode, 30 ... Thin film transistor (TFT) as transistor, 31 ... Storage capacitor, 100 ... Electricity A liquid crystal device as an optical device, 1000 ... a projection display device as an electronic device, P ... a pixel.

Claims (7)

A translucent substrate;
A translucent pixel electrode provided for each pixel on the substrate;
A transistor which is a switching element of the pixel electrode;
A storage capacitor connected to the transistor, and
The storage capacitor includes a translucent capacitor electrode disposed to face the pixel electrode through a dielectric layer,
An electro-optical device in which the pixel electrode, the dielectric layer, and the capacitive electrode have substantially the same refractive index, and the total value d of the film thicknesses satisfies the following formula (1).
d = λ / 2n (1)
λ is the wavelength of light, and n is the refractive index of the pixel electrode.   On the base material, provided on at least one of an interlayer insulating film provided between the transistor and the storage capacitor, and an upper side and a lower side of the storage capacitor, the refractive index of the capacitor electrode and the interlayer The electro-optical device according to claim 1, further comprising: a translucent insulating film having a refractive index between the refractive index of the insulating film.   The electro-optical device according to claim 2, wherein the insulating film is provided above the storage capacitor.   The electro-optical device according to claim 2, wherein the insulating film is provided on an upper side and a lower side of the storage capacitor.   The electro-optical device according to claim 2, wherein a surface of the insulating film in contact with the capacitor electrode is roughened. A liquid crystal layer as an electro-optic element;
An alignment film for controlling the alignment of liquid crystal molecules in the liquid crystal layer;
A translucent counter electrode that is disposed across the liquid crystal layer with respect to the pixel electrode;
Provided on at least one of the liquid crystal layer side of the counter electrode and the side opposite to the liquid crystal layer side of the counter electrode, the refractive index between the refractive index of the alignment film and the refractive index of the counter electrode The electro-optical device according to claim 1, further comprising: a light-transmitting other insulating film.   An electronic apparatus comprising the electro-optical device according to claim 1.

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