JP2012220753A - Electro-optic device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electro-optic device capable of achieving a retention volume having desired electric capacitance even for high definition pixels and an electronic apparatus having the same.SOLUTION: An electro-optic device includes: a data line 6a and a scan line 3a; a transistor 30 provided for corresponding to intersection of the data line 6a and scan line 3a; and a retention volume that is electrically connected with the transistor 30 and in which a first capacitor electrode 16a and a second capacitor electrode 16b are placed oppositely via a dielectric layer. The first capacitor electrode 16a includes a first conductive film and a second conductive film covering the upper and side faces of the first conductive film. The second capacitor electrode 16b opposes to the first capacitor electrode 16a on the upper and side faces of the first capacitor electrode 16a via the dielectric layer to form the retention volume.

Description

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

  As the electro-optical device, an active drive type liquid crystal device in which a switching element such as a thin film transistor is provided for each pixel is known. An active drive type liquid crystal device has a liquid crystal layer between a pair of electrodes, and an image signal written for each pixel is temporarily held in an electric capacitor including the pair of electrodes and the liquid crystal layer. In addition, a storage capacitor for electrically holding the image signal for a predetermined period is provided for each pixel.

  For example, in Patent Document 1, a light-shielding portion that covers a semiconductor layer of a transistor has a lower capacitor electrode and an upper capacitor electrode that are sequentially stacked on a substrate, and one of the capacitor electrodes is electrically connected to a pixel electrode. An electro-optical device that is a connected capacitive element is disclosed. In other words, since the capacitive element is provided in the non-opening region, a reduction in the aperture ratio of the pixel due to the provision of the capacitive element is prevented.

JP 2009-63994 A

  However, the pixel structure of Patent Document 1 has a problem in that it becomes difficult to form a capacitor element having a desired electric capacity as the pixel becomes high definition.

  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 1 An electro-optical device according to this application example is electrically connected to a data line and a scanning line, a transistor provided corresponding to an intersection of the data line and the scanning line, and the transistor, A storage capacitor in which a first capacitor electrode and a second capacitor electrode are arranged to face each other with a dielectric layer interposed therebetween, and the first capacitor electrode has an upper surface and side surfaces of the first conductive film and the first conductive film. A second conductive film covering the second capacitive electrode, and the second capacitive electrode forms the storage capacitor opposite to the first capacitive electrode through the dielectric layer on an upper surface and a side surface of the first capacitive electrode. It is characterized by.

According to this configuration, in the portion where the first capacitor electrode and the second capacitor electrode overlap with each other through the dielectric layer, the first capacitor electrode in the first capacitor electrode is compared with the case where both are flat capacitor electrodes having the same shape. Since the second capacitor electrode is provided so as to overlap the second conductive film covering the upper surface and the side surface of the one conductive film via the dielectric layer, it is possible to substantially increase the area where both the capacitive electrodes overlap. Become. In other words, a storage capacitor having a desired electric capacity can be ensured even if the pixel has high definition. That is, an electro-optical device having stable electro-optical characteristics can be provided.
In addition, since the first conductive film is protected by the second conductive film, a chemical such as a developer or an etchant is used in patterning the second capacitor electrode by using, for example, a photolithography method so as to overlap the first capacitor electrode. Even if the kind is used, it is possible to prevent the first conductive film constituting the first capacitor electrode from being damaged or deteriorated.

Application Example 2 In the electro-optical device according to the application example, the first conductive film is planarly extended in a direction in which the data line or the scanning line extends at an intersection of the data line and the scanning line. It has a main line portion that extends and a plurality of protrusion portions that protrude in a direction that intersects the main line portion in plan view.
According to this configuration, since the first conductive film has the plurality of protrusions protruding from the main line portion in the portion where the first capacitor electrode and the second capacitor electrode overlap, the planar peripheral length of the first conductive film. Can be made longer than the second capacitor electrode. That is, the electric capacity in the storage capacitor can be increased as compared with the case where only the main line portion is used.

Application Example 3 In the electro-optical device according to the application example, the second conductive film and the second capacitor electrode are formed so as to include a region between the plurality of protrusions in the first conductive film. Is preferred.
According to this configuration, the substantial surface area of the first capacitor electrode can be further increased, and the electric capacity in the storage capacitor can be further increased.

  Application Example 4 In the electro-optical device according to the application example described above, the first conductive film may have an opening in a plane at an intersection between the data line and the scanning line.

  According to this configuration, by providing the opening in the first conductive film, it is possible to realize a circumferential length longer than that of the second capacitor electrode.

  Application Example 5 In the electro-optical device according to the application example described above, it is preferable that the second conductive film and the second capacitor electrode are formed so as to include the region of the opening in the first conductive film.

  According to this configuration, the substantial surface area of the first capacitor electrode can be further increased, and the electric capacity in the storage capacitor can be further increased.

Application Example 6 An electronic apparatus according to this application example includes the electro-optical device according to the application example described above.
According to this configuration, it is possible to provide an electronic apparatus including an electro-optical device having stable electro-optical characteristics.

(A) is a schematic plan view which shows the structure of a liquid crystal device, (b) is a schematic sectional drawing cut | disconnected by the H-H 'line | wire of (a). FIG. 3 is an equivalent circuit diagram illustrating an electrical configuration of the liquid crystal device. FIG. 2 is a schematic plan view showing the arrangement of pixels in the liquid crystal device of the first embodiment. (A) And (b) is a schematic plan view which shows the structure of the pixel in the liquid crystal device of 1st Embodiment. FIG. 5 is a schematic cross-sectional view illustrating the structure of a pixel cut along line A-A ′ in FIG. FIG. 5 is a schematic cross-sectional view showing a structure of a storage capacitor cut along line B-B ′ in FIG. (A) is a schematic perspective view which shows the shape of the 1st electrically conductive film in a 1st capacity | capacitance electrode, (b) is sectional drawing which shows the structure of a storage capacity when it cuts by the C-C 'line | wire of (a). Schematic which shows the structure of the projection type display apparatus as an electronic device. The schematic plan view which shows the shape of the 1st capacity | capacitance electrode in the storage capacity of a modification. The schematic sectional drawing which shows the structure of the contact hole of a modification.

  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 following embodiments, for example, when “on the substrate” is described, the substrate is disposed so as to be in contact with the substrate, or is disposed on the substrate via another component, or the substrate. It is assumed that a part is arranged so as to be in contact with each other and a part is arranged via another component.

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

<Liquid crystal device>
First, a liquid crystal device as an electro-optical device according to this embodiment will be described with reference to FIGS. 1 and 2. 1A is a schematic plan view showing the configuration of the liquid crystal device, FIG. 1B is a schematic cross-sectional view taken along line HH ′ of FIG. 1A, and FIG. 2 is an electrical configuration of the liquid crystal device. FIG.

  As shown in FIGS. 1A and 1B, a liquid crystal device 100 according to the present embodiment includes an element substrate 10 and a counter substrate 20 that are disposed to face each other, and a liquid crystal layer 50 that is sandwiched between the pair of substrates. . As the element substrate 10 and the counter substrate 20, a transparent glass substrate such as quartz is used.

  The element substrate 10 is slightly larger than the counter substrate 20, and both substrates are bonded via a seal material 40 arranged in a frame shape, and liquid crystal having positive or negative dielectric anisotropy is sealed in the gap. A liquid crystal layer 50 is formed. For the sealing material 40, for example, an adhesive such as a thermosetting or ultraviolet curable epoxy resin is employed. A spacer (not shown) is mixed in the sealing material 40 to keep the distance between the pair of substrates constant.

  A light shielding film 21 is similarly provided in a frame shape inside the sealing material 40 arranged in a frame shape. The light shielding film 21 is made of, for example, a light shielding metal or metal oxide, and the inside of the light shielding film 21 is a display region E having a plurality of pixels P. Although not shown in FIG. 1, the display area E is also provided with a light-shielding portion that divides a plurality of pixels P in a plane.

A data line driving circuit 101 is provided between the element substrate 10 and the sealing material 40 along one side. Further, an inspection circuit 103 is provided inside the sealing material 40 along the other one side facing the one side. Further, a scanning line driving circuit 102 is provided inside the sealing material 40 along the other two sides orthogonal to the one side and facing each other. A plurality of wirings 105 that connect the two scanning line driving circuits 102 are provided inside the sealing material 40 on the other side facing the one side. 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 one side.
Hereinafter, the direction along the one side will be referred to as the X direction, and the direction along the other two sides orthogonal to the one side and facing each other will be described as the Y direction.
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 sealing material 40 between the data line driving circuit 101 and the display area E.

As shown in FIG. 1B, on the surface of the element substrate 10 on the liquid crystal layer 50 side, a light-transmitting pixel electrode 15 provided for each pixel P and a thin film transistor (TFT; Thin Film) as a switching element. Transistor) 30, 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 light shielding structure will be described later.

  On the surface of the counter substrate 20 on the liquid crystal layer 50 side, a light shielding film 21, an interlayer film layer 22 formed so as to cover the light shielding film 21, and a common electrode 23 provided so as to cover the interlayer film layer 22 are shared. An alignment film 24 covering the electrode 23 is provided.

  As shown in FIG. 1A, the light shielding film 21 is provided in a frame shape at a position where the data line driving circuit 101, the scanning line driving circuit 102, and the inspection circuit 103 overlap in plan view. Thus, the light incident from the counter substrate 20 side is shielded, and the malfunction of the peripheral circuits including these drive circuits due to the light is prevented. Further, unnecessary stray light is shielded from entering the display area E, and high contrast in the display of the display area E is ensured.

  The interlayer film layer 22 is made of an inorganic material such as silicon oxide, for example, and is provided so as to cover the light shielding film 21 with light transmittance. Examples of a method for forming such an interlayer film layer 22 include a method of forming a film using a plasma CVD method or the like.

  The common electrode 23 is made of, for example, a transparent conductive film such as ITO, and covers the interlayer film layer 22 and, as shown in FIG. 1A, the element substrate 10 side by the vertical conduction parts 106 provided at the four corners of the counter substrate 20. It is electrically connected to the wiring.

  The alignment film 18 covering the pixel electrode 15 and the alignment film 24 covering the common electrode 23 are selected based on the optical design of the liquid crystal device 100. For example, an organic material such as polyimide is formed, and the surface thereof is rubbed so that liquid crystal molecules are subjected to a substantially horizontal alignment treatment, or an inorganic material such as SiOx (silicon oxide) is vapor-phase grown. And a film formed by a method and aligned substantially perpendicularly to liquid crystal molecules.

As shown in FIG. 2, the liquid crystal device 100 is disposed so as to be parallel to the plurality of scanning lines 3 a and the plurality of data lines 6 a as signal lines that are insulated and orthogonal to each other at least in the display region E along the data lines 6 a. Capacitance line 3b.
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 15, a TFT 30, and a storage capacitor 16 are provided in a region divided by the scanning line 3a, the data line 6a, the capacitor line 3b, and these signal lines, and these constitute a pixel circuit of the pixel P. is 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 15 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 image signals D1, D2,..., Dn supplied from the data line driving circuit 101 to the pixels P. The scanning line 3a is connected to a scanning line driving circuit 102 (see FIG. 1), and supplies scanning signals SC1, SC2,..., SCm supplied from the scanning line driving circuit 102 to each pixel P. The image 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 image signals D1 to Dn supplied from the data line 6a are supplied to the pixel electrode 15 at a predetermined timing. It is the structure written in. The predetermined level of image signals D1 to Dn written to the liquid crystal layer 50 via the pixel electrode 15 is held for a certain period between the pixel electrode 15 and the common electrode 23 arranged to face each other via the liquid crystal layer 50. The
In order to prevent the held image signals D1 to Dn from leaking, the holding capacitor 16 is connected in parallel with the liquid crystal capacitor formed between the pixel electrode 15 and the common electrode 23. The storage capacitor 16 is provided between the drain of the TFT 30 and the capacitor line 3b. As will be described in detail later, the storage capacitor 16 has a dielectric layer between the light-shielding first capacitor electrode and the second capacitor electrode. In addition, the first capacitor electrode functions as the capacitor line 3b, and the first capacitor electrode has a longer planar length in comparison with the second capacitor electrode in a portion overlapping the second capacitor electrode. ing. As a result, the substantial surface area can be increased compared to the case where both are capacitive electrodes having the same shape, and a desired electric capacity is secured in the storage capacitor 16. Further, the capacitor line 3b (first capacitor electrode) is connected to a fixed potential.

  Note that a data line 6a is connected to the inspection circuit 103 shown in FIG. 1A, and an operation defect or the like of the liquid crystal device 100 is confirmed by detecting the image signal in the manufacturing process of the liquid crystal device 100. Although it can be configured, it is omitted in the equivalent circuit of FIG. The inspection circuit 103 includes a sampling circuit that samples the image signal and supplies it to the data line 6a, and a precharge circuit that supplies a precharge signal of a predetermined voltage level to the data line 6a prior to the image signal. Also good.

  Such a liquid crystal device 100 is a transmission type, and adopts an optical design of a normally white mode in which the pixel P is brightly displayed when not driven and a normally black mode in which the pixel P is darkly displayed when not driven. Polarizing elements are arranged and used according to the optical design on the light incident side and the light exit side, respectively.

  Next, the planar arrangement and structure of the pixel P will be described with reference to FIGS. 3 is a schematic plan view showing the arrangement of pixels in the liquid crystal device of the first embodiment, FIGS. 4A and 4B are schematic plan views showing the configuration of pixels in the liquid crystal device of the first embodiment, and FIG. 4 is a schematic cross-sectional view showing the structure of the pixel cut along line AA ′ in FIG. 4A, FIG. 6 is a schematic cross-sectional view showing the structure of the storage capacitor cut along line BB ′ in FIG. FIG. 7A is a schematic perspective view showing the shape of the first conductive film in the first capacitor electrode, and FIG. 7B is a cross section showing the structure of the storage capacitor when cut along the line CC ′ in FIG. FIG.

  As shown in FIG. 3, the pixel P in the liquid crystal device 100 has, for example, a substantially rectangular 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. 2 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 3b shown in FIG. 2 are provided in the non-opening region extending in the Y direction. The data line 6a and the capacitor line 3b are also made of a light-shielding conductive member, and at least a part of the non-opening region is constituted by these.

  The non-opening region can be formed not only by the signal lines provided on the element substrate 10 side, but also by the light shielding film 21 patterned in a lattice shape on the counter substrate 20 side.

  Near the intersection of the non-opening regions, the TFT 30 and the storage capacitor 16 shown in FIG. 2 are provided. 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 the other portions because the TFT 30 and the storage capacitor 16 are provided in the vicinity of the intersecting portion.

  As shown in FIG. 4A, the pixel P has a TFT 30 provided at the intersection of the scanning line 3a and the data line 6a. The TFT 30 is provided between the source region 30s, the drain region 30d, the channel region 30c, the junction region 30e provided between the source region 30s and the channel region 30c, and the channel region 30c and the drain region 30d. The semiconductor layer 30a has an LDD (Lightly Doped Drain) structure having a junction region 30f. 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 a plan view extended in the X and Y directions at the intersection with the data line 6a. A bent gate electrode 30g having an opening that planarly overlaps the extension portion and does not overlap the junction region 30f and the drain region 30d is provided.

  In the gate electrode 30g, the portion extending in the Y direction overlaps the channel region 30c in a plane. Also, the portion that overlaps the channel region 30c is bent and extends in the X direction, and the portions facing each other are electrically scanned by contact holes CNT5 and CNT6 provided between the extended portions of the scanning lines 3a. It is connected to the line 3a.

  The contact holes CNT5 and CNT6 are rectangular (rectangular) having a long X direction in a 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 has a rectangular extension portion at the intersection with the scanning line 3a. The source region is formed by a contact hole CNT1 provided in a portion protruding in the X direction from the extension portion. It is electrically connected to 30s. A portion including the contact hole CNT1 is a source electrode 31 (see FIG. 5). On the other hand, contact holes CNT2 and CNT3 are also provided at the end of the drain region 30d, and a portion including the contact hole CNT2 is a drain electrode 32 (see FIG. 5). A contact hole CNT4 is provided adjacent to the contact holes CNT2 and CNT3, and the contact hole CNT2 and the contact hole CNT3 are electrically connected by a relay electrode 6b provided in an island shape. The contact hole CNT3 and the contact hole CNT4 are relayed and electrically connected by the second capacitor electrode 16b of the storage capacitor 16. A detailed structure of the contact holes CNT1, CNT2, CNT3, and CNT4 will be described later.

  The pixel electrode 15 is provided so that the outer edge portion overlaps with the scanning line 3a and the data line 6a. In this embodiment, the pixel electrode 15 is drain electrode via two contact holes CNT3 and CNT4 provided at the position overlapping the scanning line 3a. 32 is electrically connected.

  As shown in FIGS. 4A and 4B, the storage capacitor 16 includes a first capacitor electrode 16a and a second capacitor electrode 16b disposed to face the first capacitor electrode 16a. The first capacitor electrode 16a includes a portion that overlaps the extended portion of the scanning line 3a, and a portion that extends from the portion overlapping the extended portion in the extending direction of the scanning line 3a and the extending direction of the data line 6a. And is disposed in the non-opening region (see FIG. 3).

  The first capacitor electrode 16a extends along the data line 6a, and protrudes in the X direction across the main line portion 16aa provided across the plurality of pixels P, intersects the main line portion 16aa, and is spaced in the Y direction. And three projecting portions 16ab, 16ac, and 16ad provided at a distance. The protruding portions 16ab, 16ac, and 16ad are provided so as to overlap with an extended portion at the intersection of the data line 6a and the scanning line 3a. Further, the protruding portion 16ac between the protruding portion 16ab and the protruding portion 16ad extends along the scanning line 3a except for a portion where the contact hole CNT3 is provided, and overlaps the scanning line 3a in a plane. Is provided.

  On the other hand, the second capacitor electrode 16b is provided in an island shape independently for each pixel P, as shown in FIG. The second capacitor electrode 16b of the pixel P and the second capacitor electrode 16b of the adjacent pixel P are arranged so as to surround one pixel P, thereby constituting a light-shielding non-opening region (see FIG. 3).

  More specifically, the second capacitor electrode 16b includes a quadrangular portion 16bb that planarly overlaps an extended portion at the intersection of the data line 6a and the scanning line 3a, and the quadrangular portion 16bb along the data line 6a in the Y direction. The protrusions 16ba and 16bd protrude and the protrusions 16bc and 16be protrude from the rectangular portion 16bb along the scanning line 3a. The protruding portion 16bc protrudes to a position overlapping with the contact hole CNT4, and also functions as a relay layer that electrically connects the contact hole CNT3 and the contact hole CNT4.

  A portion where the second capacitor electrodes 16b of the adjacent pixels P face each other in the same wiring layer, specifically, a portion 16c where the protruding portion 16bc and the protruding portion 16be face each other, and a portion 16d where the protruding portion 16ba and the protruding portion 16bd face each other. Are each provided with an insulating film 13a covering the first capacitor electrode 16a.

Next, the structure of the pixel P will be described in more detail with reference to FIGS.
As shown in FIG. 5, the scanning line 3 a is first formed on the element substrate 10. The scanning line 3a is, for example, a metal simple substance containing at least one of metals such as Al, Ti, Cr, W, Ta, and Mo, an alloy, a metal silicide, a polysilicide, a nitride, or a laminate of these. It can be used and has light shielding properties.

  A base insulating film 11a made of, for example, silicon oxide is formed so as to cover the scanning line 3a, and a semiconductor layer 30a is formed in an island shape on the base insulating film 11a. The semiconductor layer 30a is made of, for example, a polycrystalline silicon film, and impurity ions are implanted to form an LDD structure having the above-described source region 30s, junction region 30e, channel region 30c, junction region 30f, and drain region 30d.

  A first insulating film (gate insulating film) 11b 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 first insulating film 11b interposed therebetween.

  A second insulating film 11c is formed so as to cover the gate electrode 30g and the first insulating film 11b, and penetrates the first insulating film 11b and the second insulating film 11c at positions overlapping with respective end portions of the semiconductor layer 30a. Two contact holes CNT1 and CNT2 are formed. Then, a conductive film is formed using a light-shielding conductive part material such as Al (aluminum) so as to fill the two contact holes CNT1 and CNT2 and cover the second insulating film 11c, and patterning this, A source electrode 31 and a data line 6a connected to the source region 30s through the contact hole CNT1 are formed. At the same time, a drain electrode 32 (relay electrode 6b) connected to the drain region 30d through the contact hole CNT2 is formed.

  Next, the interlayer insulating film 12 is formed so as to cover the data line 6a, the relay electrode 6b, and the second insulating film 11c. The interlayer insulating film 12 is made of, for example, silicon oxide or nitride, 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 spin coating.

  A conductive film is formed so as to cover the interlayer insulating film 12, and the first capacitor electrode 16a is formed by patterning the conductive film by removing a portion where the contact hole CNT3 is to be formed later.

A dielectric layer 13b is formed to cover the first capacitor electrode 16a. As the dielectric layer 13b, a silicon nitride film, a single-layer film such as haunium oxide (HfO ₂ ), alumina (Al ₂ O ₃ ), tantalum oxide (Ta ₂ O ₅ ), or at least one of these single-layer films is used. A multilayer film in which two types of single-layer films are stacked may be used.

  A contact hole CNT3 penetrating the interlayer insulating film 12 and the dielectric layer 13b is formed at a position overlapping the relay electrode 6b in plan view. A conductive film is formed to fill the contact hole CNT3 and cover the dielectric layer 13b. By patterning the conductive film, the second capacitor is disposed opposite to the first capacitor electrode 16a and connected to the relay electrode 6b via the contact hole CNT3. Electrode 16b is formed.

  Next, an interlayer insulating film 14 that covers the second capacitor electrode 16b and the dielectric layer 13b is formed. The interlayer insulating film 14 is also made of, for example, silicon oxide or nitride, and may be planarized in the same manner as the interlayer insulating film 12.

  A contact hole CNT4 penetrating the interlayer insulating film 14 is formed at a position overlapping the second capacitor electrode 16b, and a transparent conductive film such as ITO is formed so as to fill the contact hole CNT4. The transparent conductive film is patterned to form a pixel electrode 15 connected to the second capacitor electrode 16b through the contact hole CNT4.

  As described above, the second capacitor electrode 16b is electrically connected to the drain electrode 32 of the TFT 30 via the contact hole CNT3 and the relay electrode 6b, and is electrically connected to the pixel electrode 15 via the contact hole CNT4. . As described above, the main line portion 16aa of the first capacitance electrode 16a is formed so as to straddle a plurality of pixels P in the extending direction (Y direction) of the data line 6a, and also as the capacitance line 3b in the equivalent circuit (see FIG. 2). It is functioning. Thus, the potential applied to the pixel electrode 15 via the drain electrode 32 of the TFT 30 can be held between the first capacitor electrode 16a and the second capacitor electrode 16b.

  Next, the configuration and structure of the storage capacitor 16 will be described in more detail with reference to FIGS. As shown in FIG. 6, the first capacitor electrode 16a provided on the interlayer insulating film 12 includes a first conductive film 16a1 and a second conductive film 16a2 that covers and protects the first conductive film 16a1. is doing.

  The first conductive film 16a1 is formed using, for example, Al (aluminum), which is a low-resistance wiring material, and has a thickness of approximately 200 nm to 350 nm.

  The second conductive film 16a2 is provided to protect the first conductive film 16a1 from being oxidized or damaged so as not to lose its function. For example, Ti—N (metal nitride) Titanium nitride) or the like can be used. The thickness is approximately 100 nm to 150 nm.

  On the first capacitor electrode 16a, in the portions 16c and 16d (see FIG. 4B) where the second capacitor electrodes 16b of the adjacent pixels P face each other, an insulating film 13a is formed so as to cover the first capacitor electrode 16a. Has been. The insulating film 13a is, for example, silicon oxide or nitride, and has a thickness of about 50 nm to 100 nm.

A dielectric layer 13b is formed to cover the first capacitor electrode 16a on which the insulating film 13a is formed. As described above, the dielectric layer 13b is formed of a silicon nitride film, a single layer film such as humic oxide (HfO ₂ ), alumina (Al ₂ O ₃ ), tantalum oxide (Ta ₂ O ₅ ), or a single layer thereof. A multilayer film in which at least two kinds of single-layer films are laminated can be used. In this embodiment, a multilayer film of alumina (Al ₂ O ₃ ) and haunium oxide (HfO ₂ ) is used, and the thickness is approximately 20 nm to 30 nm.

Subsequently, a conductive film is formed on the dielectric layer 13b, and is patterned so as to face the first capacitor electrode 16a, thereby forming the second capacitor electrode 16b.
For example, Ti-N (titanium nitride), which is the same metal nitride as the second conductive film 16a2, can be used as the conductive film forming the second capacitor electrode 16b. The thickness is approximately 200 nm. By using Ti-N having excellent chemical resistance and wear resistance, it is possible to prevent the storage capacitor 16 from being deteriorated or damaged in the subsequent step of forming the interlayer insulating film 14 or the pixel electrode 15. . Even when the conductive film is etched on the second conductive film 16a2 during the patterning of the second capacitor electrode 16b, the etched portion is covered with the insulating film 13a and the dielectric layer 13b. Etching up to the second conductive film 16a2 made of the same material is prevented.

  As shown in FIG. 7A, the first capacitor electrode 16a extends in the Y direction along the data line 6a in a portion overlapping the extension portion at the intersection of the scanning line 3a and the data line 6a. Main line portion 16aa and three projecting portions 16ab, 16ac, and 16ad that intersect the main line portion 16aa and project in the X direction, that is, the direction along the scanning line 3a.

  As the pixel P becomes higher in definition, the planar size of the extension portion is restricted and must be reduced. Then, the planar size of each capacitor electrode of the storage capacitor 16 arranged in the non-opening region is also restricted. Therefore, by providing the projecting portions 16ab, 16ac, and 16ad as in the present embodiment, the planar perimeter is made longer than the first capacitor electrode 16a having a simple quadrangle as in the case of the expansion portion. In addition, not only the upper surface but also the side surface portion in the thickness direction can be used as a capacitive electrode.

As shown in FIG. 7B, the second conductive film 16a2 includes a top surface and a side surface of the first conductive film 16a1 exposed on the interlayer insulating film 12, and a protruding portion 16ab in a portion overlapping the extension portion in plan view. , 16ac, and 16ad are preferably formed so as to cover the region.
The dielectric layer 13b is formed so as to cover the second conductive film 16a2, and the second capacitor electrode 16b is further formed so as to cover the dielectric layer 13b.

  Therefore, it is possible to substantially increase the area of both the capacitance electrodes, rather than making the first capacitance electrode 16a and the second capacitance electrode 16b into a simple quadrangle as in the case of the expansion portion.

The effects in the above embodiment are as follows.
(1) The storage capacitor 16 is disposed in the non-opening region so as to overlap the extended portion at the intersection of the scanning line 3a and the data line 6a. The first capacitor electrode 16a of the storage capacitor 16 has a main line portion 16aa that functions as the capacitor line 3b, and three projecting portions 16ab, 16ac, and 16ad that intersect the main line portion 16aa in a portion overlapping the second capacitor electrode 16b. is doing. Therefore, in the portion that overlaps the second capacitor electrode 16b, the planar circumference of the first capacitor electrode 16a is longer than the case where the shape of the first capacitor electrode 16a is a simple quadrangle as in the extended portion. Thus, the area facing the second capacitor electrode 16b through the dielectric layer 13b is increased. Therefore, the storage capacitor 16 having a desired electric capacity can be realized even if the pixel P has a high definition.

  (2) The first capacitor electrode 16a of the storage capacitor 16 includes a first conductive film 16a1 having a long planar circumference and a second conductive film 16a2 that covers and protects the first conductive film 16a1. Therefore, even if the photolithography method is used to form the dielectric layer 13b and the second capacitor electrode 16b on the second conductive film 16a2, the second conductive film 16a2 is more resistant to chemicals than the first conductive film 16a1. In addition, since it is excellent in wear resistance, problems such as etching or damage to the lower first conductive film 16a1 are less likely to occur. Therefore, it is possible to configure the storage capacitor 16 that can obtain an electrically stable characteristic.

  (3) In addition, the second conductive film 16a2 is formed so as to cover the first conductive film 16a1 including the region between the three protrusions 16ab, 16ac, and 16ad, so that the first conductive film 16a1 is simply formed. As compared with the case where only the surface (the upper surface and the side surface) is covered, the substantial electric capacity of the storage capacitor 16 can be increased.

(Second Embodiment)
<Electronic equipment>
FIG. 8 is a schematic diagram illustrating a configuration of a projection display device as an electronic apparatus. As shown in FIG. 8, a projection display apparatus 1000 as an electronic apparatus according to this embodiment includes a polarized 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 video information (video signal) 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 on 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 described above is applied. The liquid crystal device 100 is arranged with a gap between a pair of polarizing elements arranged in crossed Nicols on the incident side and the emission side of colored light. The same applies to the other liquid crystal light valves 1220 and 1230.

  According to such a projection display apparatus 1000, the liquid crystal device 100 is provided which can obtain a stable operation state by the holding capacitor 16 having a desired electric capacity even when the plurality of pixels P are arranged with high definition. Even when strong (bright) light is emitted from the lamp unit 1101 to the liquid crystal light bulbs 1210, 1220, and 1230, high display quality is realized.

  Various modifications other than the above embodiment are conceivable. Hereinafter, a modification will be described.

(Modification 1) In the liquid crystal device 100 of the above-described embodiment, the method of increasing the planar peripheral length of the first capacitor electrode 16a of the storage capacitor 16 is to project the protrusions 16ab, 16ac, 16ad in the direction intersecting with the main line portion 16aa. It is not limited to providing. FIG. 9 is a schematic plan view showing the shape of the first capacitor electrode in the storage capacitor of the modification.
As shown in FIG. 9, for example, in the portion where the first capacitor electrode 16 a overlaps the second capacitor electrode 16 b, the main line portion 16 aa and the branch that is divided into at least two from the main line portion 16 aa and connected to the main line portion 16 aa again. It is good also as a structure which has part 16af and 16ag. According to this, the planar peripheral length of the first capacitor electrode 16a is increased by providing the branch portions 16af and 16ag and the opening 16ah surrounded by the branch portions 16af and 16ag at the portion overlapping the second capacitor electrode 16b. Can do. The first capacitor electrode 16a includes a first conductive film 16a1 and a second conductive film 16a2 that covers the first conductive film 16a1. Further, the first conductive film 16a1 has the branch portions 16af and 16ag, and the second conductive film 16a2 is formed so as to cover the first conductive film 16a1 including the opening 16ah to secure a larger electric capacity. This is preferable.
Moreover, when forming the protrusions 16ab, 16ac, and 16ad intersecting with the main line portion 16aa as in the above embodiment, if the main line portion 16aa becomes narrower than a predetermined width, the electrical resistance may increase. A predetermined electrical resistance can be ensured in the function as the capacitor line 3b by forming the pattern shape in which the branch portions 16af and 16ag are closed with respect to the main line portion 16aa as in the modification.

(Modification 2) In the liquid crystal device 100 of the above embodiment, the configuration of the contact hole CNT3 that electrically connects the pixel electrode 15 and the drain electrode 32 is not limited to this. FIG. 10 is a schematic cross-sectional view illustrating a configuration of a contact hole according to a modification.
As shown in FIG. 10, a contact hole CNT3 is formed at a position overlapping the drain electrode 32 (relay electrode 6b) of the interlayer insulating film 12, and the conductive film is formed so as to fill the contact hole CNT3 and cover the interlayer insulating film 12. By depositing and patterning, the first capacitor electrode 16a and the relay electrode 16e connected to the drain electrode 32 through the contact hole CNT3 are formed.
Next, for the purpose of protecting the relay electrode 16e, an insulating film 13a is formed so as to cover a portion and an end portion overlapping the contact hole CNT4 of the relay electrode 16e.
A dielectric layer 13b is formed so as to cover the first capacitor electrode 16a, the relay electrode 16e, and the insulating film 13a. In the dielectric layer 13b, a portion overlapping the contact hole CNT3 is removed by patterning.
Then, a conductive film is formed so as to cover the dielectric layer 13b, and the second capacitor electrode 16b is formed by patterning the conductive film. In this way, the contact hole CNT3 is filled with the conductive film constituting the first capacitor electrode 16a and the second capacitor electrode 16b, so that stable electrical connection can be obtained and the contact hole CNT3 can be formed on the contact hole CNT3. The unevenness of the interlayer insulating film 14 can be reduced. That is, unevenness on the surface of the interlayer insulating film 14 on which the alignment film is formed is reduced, and alignment disorder of liquid crystal molecules due to the unevenness can be reduced.

  (Modification 3) The arrangement of the semiconductor layer 30a in the TFT 30 is not limited to the arrangement overlapping the scanning line 3a as in the first embodiment. For example, the configuration of the storage capacitor 16 of the present application can be applied even if the semiconductor layer 30a is arranged so as to be overlapped with the data line 6a or the semiconductor layer 30a is bent in the middle so as to overlap the scanning line 3a and the data line 6a.

  (Modification 4) The electronic apparatus to which the liquid crystal device 100 is applied is not limited to the projection display device 1000 of the above embodiment. For example, a projection-type HUD (head-up display), a direct-view HMD (head-mounted display), an electronic book, a personal computer, a digital still camera, an LCD TV, a viewfinder-type or monitor-direct-view video recorder, car navigation It can be suitably used as a display unit of an information terminal device such as a system, electronic notebook, or POS.

  (Modification 5) The electro-optical device to which the wiring structure of the element substrate 10 can be applied is not limited to the liquid crystal device 100. For example, it is an active drive type electro-optical device including a transistor, and can be applied to a display device such as an organic EL (Electro Luminessence) device or an electrophoresis device.

  3a ... Scanning line, 6a ... Data line, 16 ... Retention capacitor, 16a ... First capacitance electrode, 16aa ... Main line portion of the first capacitance electrode, 16a1 ... First conductive film, 16a2 ... Second conductive film, 16ab, 16ac, 16ad ... projection, 16af, 16ag ... branch, 16ah ... opening, 16b ... second capacitance electrode, 16ba, 16bc, 16bd, 16be ... projection, 100 ... liquid crystal device as electro-optical device, 1000 ... electronic device Projection type display device.

Claims (6)

Data lines and scan lines;
A transistor provided corresponding to the intersection of the data line and the scanning line;
A storage capacitor that is electrically connected to the transistor and in which a first capacitor electrode and a second capacitor electrode are disposed to face each other with a dielectric layer interposed therebetween,
The first capacitor electrode includes a first conductive film and a second conductive film covering an upper surface and side surfaces of the first conductive film,
The electro-optical device, wherein the second capacitor electrode is opposed to the first capacitor electrode through the dielectric layer on an upper surface and a side surface of the first capacitor electrode. The first conductive film includes a main line portion that extends in a plane in a direction in which the data line or the scan line extends, and a main line portion that extends in a plane at an intersection between the data line and the scan line. The electro-optical device according to claim 1, further comprising a plurality of projecting portions projecting in a crossing direction. The electro-optical device according to claim 2, wherein the second conductive film and the second capacitor electrode are formed to include a region between the plurality of protrusions in the first conductive film. 2. The electro-optical device according to claim 1, wherein the first conductive film has an opening in a plane at an intersection between the data line and the scanning line. The electro-optical device according to claim 4, wherein the second conductive film and the second capacitor electrode are formed so as to include a region of the opening in the first conductive film.   An electronic apparatus comprising the electro-optical device according to claim 1.

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