JP2009069247A - Electro-optical device, manufacturing method thereof, electronic apparatus, and wiring structure - Google Patents

Abstract

For example, in an electro-optical device such as a liquid crystal device, a higher-quality pixel can be realized by increasing a storage capacity.
An electro-optical device includes a substrate (10), a data line (6a) and a scanning line (11a) extending across each other in a display area (10a) on the substrate, a data line and a scanning line. An electrically connected transistor (30), a pixel electrode (9a) provided corresponding to the transistor, and a stopper film (200) formed on at least one of the data line and the scanning line A step-forming film (45) which is locally formed on the stopper film and has a side wall which stands out from the stopper film, and a lower electrode (71) and a lower electrode which are formed so as to straddle at least the side wall And a capacitor (70) having an upper electrode (300) facing each other through a capacitor insulating film (75).
[Selection] Figure 4

Description

  The present invention relates to a technical field of an electro-optical device such as a liquid crystal device, a method for manufacturing the electro-optical device, an electronic apparatus such as a liquid crystal projector including the electro-optical device, and a wiring structure.

  This type of electro-optical device includes a pixel electrode, a scanning line for selectively driving the pixel electrode, a data line, and a TFT (Thin Film Transistor) as a pixel switching element on a substrate, and is active. It is configured to be capable of matrix driving. Also, a storage capacitor is generally provided between the TFT and the pixel electrode for the purpose of increasing the contrast and the like, and a technique for increasing the area of the capacitor element in order to secure more capacitance is disclosed. Has been.

  For example, Patent Literature 1 and Patent Literature 2 disclose a technique of providing a capacitive element along a recess. Patent Document 3 discloses a technique of providing a capacitive element in a tapered opening. Further, Patent Document 4 discloses a technique in which a capacitive element is provided along a grooved glass substrate.

JP-A-2005-115104 JP-A-5-265034 Japanese Patent Laid-Open No. 2001-60666 Japanese Patent Laid-Open No. 11-354743

  However, in the above-described technique, for example, when forming a recess, a groove, or the like by etching or the like, there is a variation in height due to insufficient accuracy of etching, which causes a variation in capacitance. There is a problem. Further, there is a technical problem that excessive etching damages other than the one to be removed (for example, a wiring disposed in a lower layer), resulting in disconnection or short circuit.

  The present invention has been made in view of, for example, the above-described problems. An electro-optical device capable of displaying a higher quality image by increasing a storage capacity, a method of manufacturing the electro-optical device, and the electric It is an object to provide an electronic device including an optical device and a wiring structure.

  In order to solve the above problems, an electro-optical device of the present invention is electrically connected to a substrate, a data line and a scanning line extending in a pixel region on the substrate, and the data line and the scanning line. Connected transistors, pixel electrodes provided corresponding to the transistors, stopper films formed on at least one of the data lines and the scanning lines, and locally formed on the stopper films A step-forming film having a side wall that stands out from the stopper film, a lower electrode formed so as to straddle at least the side wall, and an upper electrode facing the lower electrode through a capacitive insulating film Capacity.

  According to the electro-optical device of the present invention, during the operation, for example, the scanning signal is supplied from the scanning line while the supply of the image signal from the data line to the pixel electrode is controlled, so that an image display by a so-called active matrix system is possible. Become. The image signal is transferred from the data line to the transistor at a predetermined timing by turning on / off a transistor, which is a switching element electrically connected between the data line and the pixel electrode, according to a scanning signal supplied from the scanning line. And is supplied to the pixel electrode provided corresponding to the transistor. The pixel electrode is a transparent electrode made of a transparent conductive material such as ITO (Indium Tin Oxide), for example, and a plurality of pixel electrodes are provided in a matrix form in a region to be a display region on the substrate corresponding to the intersection of the data line and the scanning line. It is done.

  The transistor described above includes, for example, a semiconductor layer having a channel region, a data line side source / drain region, and a pixel electrode side source / drain region, a gate electrode overlapping the channel region, and a gate insulating film disposed between the semiconductor layer and the gate electrode. Is built by. Note that the transistor may be a double-gate thin film transistor in which two gate electrodes are sandwiched from the top or bottom of the semiconductor layer or two gate electrodes exist in two channel regions connected in series. Furthermore, there may be three or more gate electrodes. Alternatively, a transistor having an LDD structure in which an LDD region is provided in a semiconductor layer may be used.

  Here, in the present invention, in particular, a stopper film (that is, an etching stopper film) is formed on at least one of the data line and the scanning line. The stopper film is formed so as to cover, for example, the data line or the scanning line when viewed in plan on the substrate.

  On the stopper film, a step forming film having a side wall that is cut off from the stopper film is locally formed. The step forming film is typically an insulating film, patterned by etching, and formed to have the side walls as described above. Here, at the time of etching, the above-described stopper film functions as a protective film for protecting the wiring existing on the lower layer side of the stopper film such as the data line and the scanning line. Therefore, the side wall as described above can be easily formed by etching. In addition, the stopper film prevents the data line and the scanning line from being short-circuited with other wirings, electrodes, or the like arranged so as to face each other due to excessive etching.

  A lower electrode is formed on the step formed by the step forming film described above so as to straddle at least the side wall in a stepped manner. Further, an upper electrode is formed on the upper layer of the lower electrode so as to face each other with a capacitive insulating film therebetween, thereby forming a capacitor. Since the capacitance is formed in a step, the capacitance is larger than that in a case where the capacitance is formed on a flattened surface, for example. That is, since the capacitance is also formed in the portion corresponding to the side wall of the step forming film, the capacitance has a three-dimensional spread. Therefore, it is possible to increase the capacity without increasing the arrangement area when viewed in plan. This is extremely effective when it is intended to improve the aperture ratio or to reduce the size of the apparatus.

  Further, since the stopper film described above is formed, the etching depth of the step forming film does not vary. For this reason, there is little or no variation in the capacitance formed at the step. Therefore, even when the etching accuracy is not so high, the capacity can be stably increased.

  As described above, according to the electro-optical device according to the present invention, it is possible to increase the capacity more easily and efficiently by providing the stopper film and the step forming film.

  In one aspect of the electro-optical device of the present invention, the capacitor is a storage capacitor electrically connected to the pixel electrode.

  According to this aspect, the capacitor is electrically connected to the pixel electrode. Therefore, the capacitor functions as a storage capacitor that prevents the image display voltage in the pixel electrode from being lowered. In addition to the function as the storage capacitor, the capacitor for assisting the storage capacity of the data line, the capacity for assisting the storage capacity of the scanning line, and other charge storage constituting the various pixel circuits. Or a capacitor for holding electric charge. By preventing the voltage for image display from being lowered by the storage capacity, for example, high contrast can be achieved. As described above, according to the electro-optical device according to this aspect, it is possible to display a high-quality image.

  In another aspect of the electro-optical device according to the aspect of the invention, the side wall is a side wall that defines the periphery of the opening so that the stopper film faces the upper layer side through the opening formed in the step forming film. .

  According to this aspect, the side wall in the step forming film is a side wall that defines the periphery of the opening opened in the step forming film. That is, the step formed by the step forming film is formed as a recess. The opening described above is opened so that the stopper film faces the upper layer side through the opening. That is, the opening is formed by etching the step forming film to the depth of the stopper film. Etching at this time can be easily and uniformly performed by providing the stopper film.

  In this embodiment, in particular, the lower electrode, the capacitor insulating film, and the upper electrode that form the capacitor are arranged so as to drop into the opening formed in the step forming film. Therefore, the capacitor is also formed at a portion corresponding to the side wall of the step forming film and has a three-dimensional spread. Therefore, the capacity can be increased efficiently.

  In another aspect of the electro-optical device of the present invention, the side wall is a side wall that defines the periphery of the step forming film provided in an island shape.

  According to this aspect, the side wall in the step forming film is a side wall that defines the periphery of the step forming film provided in an island shape. That is, the step formed by the step forming film is formed as a convex portion. When the island-shaped step forming film is formed, for example, the step forming film formed so as to cover the stopper film in a planar manner is etched to the depth of the stopper film to leave the island shape. It is formed by removing other than. Etching at this time can be easily and uniformly performed by providing the stopper film.

  In this embodiment, in particular, the lower electrode, the capacitor insulating film, and the upper electrode that form a capacitor are arranged so as to straddle the step forming film provided in an island shape. Therefore, the capacitor is also formed at a portion corresponding to the side wall of the step forming film and has a three-dimensional spread. Therefore, the capacity can be increased efficiently.

  In another aspect of the electro-optical device according to the aspect of the invention, the electro-optical device may further include a base film that is locally formed under the stopper film and forms a step on the surface of the stopper film. Is formed.

  According to this aspect, the step is formed on the surface of the stopper film by the base film locally formed under the stopper film. The base film may be an insulating film such as an interlayer insulating film, the same film as a gate insulating film, and the same film as a capacitive insulating film, or a conductive film such as some wiring or the same film as the certain wiring. Alternatively, it may be a semiconductor film. Such a step occurs unintentionally unless a planarization process such as a CMP (Chemical Mechanical Polishing) process is performed on an interlayer insulating film stacked above a locally formed base film. . The level difference that occurs is actively used here to increase capacity.

  In this embodiment, in particular, a capacitor is also formed at the step formed by the above-described base film. Therefore, as in the case of the step formed by the step forming film described above, the capacitance has a three-dimensional spread. Accordingly, the capacitance can be increased more efficiently by the step formed by the step forming film and the step formed by the base film.

  Further, by using the step formed by the base film, the step formed by the step forming film can be increased. That is, the step can be increased by forming the step in two steps, that is, the base film and the step forming film. In this case, the capacity area formed in the step increases as the step increases. Therefore, it is possible to effectively increase the capacity.

  In another aspect of the electro-optical device according to the aspect of the invention, the other wiring that is not at least one of the data wiring and the scanning line, or another wiring that is different from any of the data wiring and the scanning line, It is formed locally under the stopper film, and a step is formed on the surface of the stopper film depending on the presence or absence of the other wiring, and the capacitor is also formed on the step.

  According to this aspect, the stopper film is formed by the other wiring that is not at least one of the data wiring and the scanning line locally formed under the stopper film, or the other wiring that is different from any of the data wiring and the scanning line. A step is formed on the surface. Such a level difference occurs unintentionally unless the interlayer insulating film laminated above the locally formed wiring is subjected to a planarization process such as a CMP process. The level difference that occurs is actively used here to increase capacity.

  In this embodiment, in particular, a capacitor is also formed at the step formed by the other wiring described above. Therefore, as in the case of the step formed by the step forming film described above, the capacitance has a three-dimensional spread. Therefore, the capacitance can be increased more efficiently by the step formed by the step forming film and the step formed by another wiring.

  Further, the step formed by the step forming film can be increased by using the step formed by the other wiring. That is, the step can be enlarged by forming the step in two steps, that is, another wiring and a step forming film. In this case, the capacity area formed in the step increases as the step increases. Therefore, it is possible to effectively increase the capacity.

  In another aspect of the electro-optical device of the present invention, a spacer insulating film is further provided between the lower electrode and the upper electrode.

  According to this aspect, the spacer insulating film is formed between the lower electrode and the upper electrode forming the capacitor. The spacer insulating film is typically provided on the lower layer side of the capacitive insulating film, and functions as a protective film for preventing the lower electrode from being damaged when the upper electrode is etched. In addition, it does not need to be provided in a place where the upper electrode covers the lower electrode (that is, a place where the lower electrode is not likely to be damaged by etching of the upper electrode).

  In this aspect, as described above, when the upper electrode is etched and patterned, the wiring and electrodes such as the lower electrode formed on the lower layer side can be prevented from being damaged. Therefore, the capacitor can be formed more easily. In particular, when the capacitor is formed in a step, the structure of each layer is complicated as compared with the case where the capacitor is formed on a flat surface. Therefore, it is extremely effective in practice to easily form a capacitor.

  In another aspect of the electro-optical device of the present invention, the electro-optical device further includes another capacitive electrode formed of the same film as the scanning line and having the same potential as the upper electrode, and the stopper film includes the other capacitive electrode and It functions as a dielectric film that constructs another capacitor connected in parallel to the capacitor between the lower electrodes.

  According to this aspect, the capacitor electrode further disposed opposite to the lower electrode via the stopper film is further provided. The other capacitor electrode is formed of the same film as the scanning line and has the same potential as the upper electrode. Here, the “same film” means films formed by the same film forming process, and the thicknesses of the films may not be the same. Further, the “same potential” does not have to be exactly the same value, but may be a value that can form a capacitor between another capacitor electrode and a lower electrode as will be described later.

  When the other capacitor electrode has the same potential as the upper electrode, the stopper film functions as a dielectric film that builds a capacitor between the other capacitor electrode and the lower electrode. That is, in addition to the capacitor constructed by the upper electrode and the lower electrode, another capacitor constructed by another capacitor electrode and the lower electrode is formed. The other capacitor is formed as a capacitor connected in parallel to the capacitor constructed by the upper electrode and the lower electrode. As described above, by making the stopper film function as a dielectric film, the capacity can be increased without increasing the planar arrangement area of the capacity. Therefore, the capacity can be increased more efficiently.

In another aspect of the electro-optical device according to the aspect of the invention, the stopper film is provided in a non-opening region except an opening region through which light contributing to display is transmitted or reflected in the display region. The film is provided in a non-opening region excluding the opening region. In the non-opening region, typically, a grid-shaped or striped light-shielding film called a black matrix or a black mask is formed, and the light-shielding film, a light-shielding data line, a scanning line, and a capacitor line are formed. Etc., a grid-like non-opening region is constructed. The opening area in each pixel is defined by the non-opening area. Here, as described above, the stopper film is effective when forming the side wall of the step forming film. On the other hand, since the capacitor is typically provided in the non-opening region, the sidewall of the step forming film is also provided in the non-opening region. That is, the same effect can be obtained even when there is little or no stopper film in the opening region.

  Furthermore, by providing little or no stopper film in the opening region, even a film having a low transmittance or an opaque film can be employed as the stopper film. In other words, the light that contributes to the display in the display region can be prevented from being blocked by the stopper film. Therefore, it is possible to prevent or reduce the deterioration of the quality of the displayed image.

  In another aspect of the electro-optical device according to the aspect of the invention, the stopper film includes a nitrogen compound.

  According to this aspect, since the stopper film contains the nitrogen compound, it has a light shielding performance. Therefore, for example, light that is about to enter a semiconductor layer included in the transistor can be blocked. Therefore, it is possible to prevent the occurrence of light leakage current. Further, as in the above-described aspect, the stopper film can function as a dielectric film that forms a capacitor. In addition, since it contains a nitrogen compound, it is possible to enhance resistance such as prevention of moisture ingress by the stopper film.

  Further, it can be easily removed by, for example, etching using hot phosphoric acid. Therefore, for example, when it is formed in an unnecessary region or when it becomes unnecessary after functioning as a protective film during etching, it can be easily removed. Therefore, the manufacturing process can be made easier.

  In order to solve the above problems, an electronic apparatus according to the present invention includes the above-described electro-optical device according to the present invention (including various aspects thereof).

  According to the electronic apparatus of the present invention, since the electro-optical device according to the present invention described above is provided, a projection display device, a television, a mobile phone, an electronic notebook, and a word processor capable of performing high-quality display. Various electronic devices such as a viewfinder type or a monitor direct view type video tape recorder, a workstation, a videophone, a POS terminal, and a touch panel can be realized. Further, as the electronic apparatus of the present invention, for example, an electrophoretic device such as electronic paper can be realized.

  In order to solve the above-described problem, a method of manufacturing an electro-optical device according to an aspect of the invention electrically connects a data line and a scanning line that intersect with each other in a pixel region on a substrate, and the data line and the scanning line. And a pixel electrode provided corresponding to the transistor, wherein a stopper film is formed on at least one of the data line and the scanning line. Forming a step forming film having a side wall that is cut off from the stopper film by etching patterning on the stopper film, a lower electrode straddling at least the side wall in a stepped manner, and capacitive insulation between the lower electrode and the lower electrode Forming an upper electrode facing each other through a film, and forming a capacitance by the lower electrode and the upper electrode.

  According to the electro-optical device manufacturing method of the present invention, the above-described electro-optical device of the present invention can be manufactured. Here, in particular, by forming the stopper film, the step forming film formed on the upper layer of the stopper film can be etched more easily and uniformly. Therefore, the capacity can be increased more easily and efficiently.

  In order to solve the above-described problem, the wiring structure of the present invention is provided on at least one of the first wiring and the second wiring, and the first wiring and the second wiring that cross each other. A stopper film formed on the stopper film, a step-forming film locally formed on the stopper film, and having a side wall standing off from the stopper film, and a lower part formed so as to straddle at least the side wall And a capacitor having an upper electrode facing the electrode and the lower electrode through a capacitor insulating film.

  According to the wiring structure of the present invention, it is possible to increase the capacity more easily and efficiently as in the case of the electro-optical device of the present invention described above. Therefore, since charges can be stored efficiently, a device capable of high-quality operation can be realized.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a TFT active matrix driving type liquid crystal device with a built-in driving circuit, which is an example of the electro-optical device of the present invention, is taken as an example.

<First Embodiment>
First, the overall configuration of the liquid crystal device according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view schematically showing the configuration of the liquid crystal device according to this embodiment, and FIG. 2 is a cross-sectional view taken along line HH ′ of FIG.

  1 and 2, the liquid crystal device according to the present embodiment includes a TFT array substrate 10 and a counter substrate 20 which are arranged to face each other. The TFT array substrate 10 is a transparent substrate such as a quartz substrate, a glass substrate, or a silicon substrate. The counter substrate 20 is also a transparent substrate made of the same material as the TFT array substrate 10, for example. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20, and the TFT array substrate 10 and the counter substrate 20 are provided with a sealing material 52 provided in a seal region located around the pixel region 10a. Are bonded to each other.

  The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 10 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is. Further, for example, in the sealing material 52, a gap material 56 such as a glass fiber or a glass bead for dispersing the distance (inter-substrate gap) between the TFT array substrate 10 and the counter substrate 20 to a predetermined value is dispersed. The liquid crystal device according to this embodiment is small and suitable for performing enlarged display for a light valve of a projector.

  A light-shielding frame light-shielding film 53 that defines the frame region of the pixel region 10a is provided on the counter substrate 20 side in parallel with the inside of the seal region where the sealing material 52 is disposed. However, part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side.

  On the TFT array substrate 10, a data line driving circuit 101, a sampling circuit 7, a scanning line driving circuit 104, and an external circuit connection terminal 102 are formed in the peripheral area located around the pixel area 10 a.

  In the peripheral region on the TFT array substrate 10, the data line driving circuit 101 and the external circuit connection terminal 102 are provided along one side of the TFT array substrate 10 on the outer peripheral side from the seal region. In addition, a region located on the inner side of the seal region in the peripheral region on the TFT array substrate 10 is covered with the frame light shielding film 53 along one side of the pixel region 10 a along one side of the TFT array substrate 10. A sampling circuit 7 is arranged.

  The scanning line driving circuit 104 is provided along two sides adjacent to one side of the TFT array substrate 10 so as to be covered with the frame light shielding film 53. Further, in order to electrically connect the two scanning line driving circuits 104 provided on both sides of the pixel region 10a in this way, the TFT array substrate 10 is covered with the frame light shielding film 53 along the remaining side. A plurality of wirings 105 are provided.

  In the peripheral region on the TFT array substrate 10, vertical conduction terminals 106 are disposed in regions facing the four corners of the counter substrate 20, and vertical conduction is provided between the TFT array substrate 10 and the counter substrate 20. A material is provided corresponding to the vertical conduction terminal 106 and electrically connected to the terminal 106.

  In FIG. 2, on the TFT array substrate 10, a laminated structure in which pixel switching TFTs as drive elements, wiring lines such as scanning lines and data lines are formed is formed. In the pixel region 10a, pixel electrodes 9a are provided in a matrix on the upper layer of wiring such as pixel switching TFTs, scanning lines, and data lines. An alignment film 16 is formed on the pixel electrode 9a. In the present embodiment, the pixel switching element may be constituted by various transistors, TFD, or the like in addition to the TFT.

  On the other hand, a light shielding film 23 is formed on the surface of the counter substrate 20 facing the TFT array substrate 10. The light shielding film 23 is formed of, for example, a light shielding metal film or the like, and is patterned, for example, in a lattice shape in the pixel region 10 a on the counter substrate 20. A counter electrode 21 made of a transparent material such as ITO is formed on the light shielding film 23 (below the light shielding film 23 in FIG. 2) so as to face the plurality of pixel electrodes 9a. An alignment film 22 is formed on the upper side (below the counter electrode 21 in FIG. 2).

  The liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films. A liquid crystal storage capacitor is formed between the pixel electrode 9 a and the counter electrode 21 by applying a voltage to each of the liquid crystal devices during driving.

  Although not shown here, on the TFT array substrate 10, in addition to the data line driving circuit 101 and the scanning line driving circuit 104, a plurality of data lines are precharged at a predetermined voltage level prior to the image signal. A precharge circuit to be supplied, an inspection circuit for inspecting the quality, defects, etc. of the liquid crystal device during manufacture or at the time of shipment may be formed.

  Next, an electrical configuration of the pixel portion of the liquid crystal device according to the present embodiment will be described with reference to FIG. FIG. 3 is an equivalent circuit diagram of various elements, wirings, and the like in a plurality of pixels formed in a matrix that forms the pixel region of the liquid crystal device according to this embodiment.

  In FIG. 3, a pixel electrode 9 a and a TFT 30 as an example of a “transistor” according to the present invention are formed in each of a plurality of pixels formed in a matrix that forms the pixel region 10 a. The TFT 30 is electrically connected to the pixel electrode 9a, and performs switching control of the pixel electrode 9a during operation of the liquid crystal device. The data line 6a to which the image signal is supplied is electrically connected to the source of the TFT 30. The image signals S1, S2,..., Sn written to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. Good.

  The scanning line 11a is electrically connected to the gate of the TFT 30, and the liquid crystal device according to the present embodiment applies the scanning signals G1, G2,..., Gm to the scanning line 11a in this order at a predetermined timing. It is configured to apply line-sequentially. The pixel electrode 9a is electrically connected to the drain of the TFT 30, and the image signal S1, S2,..., Sn supplied from the data line 6a is obtained by closing the TFT 30 as a switching element for a certain period. It is written at a predetermined timing. Image signals S 1, S 2,..., Sn written in a liquid crystal as an example of an electro-optical material via the pixel electrode 9 a are held for a certain period with the counter electrode formed on the counter substrate.

  The liquid crystal constituting the liquid crystal layer 50 (see FIG. 2) modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The transmittance for light is increased, and light having a contrast corresponding to an image signal is emitted from the liquid crystal device as a whole.

  In order to prevent the image signal held here from leaking, a storage capacitor 70 is added electrically in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode 21 (see FIG. 2). ing. The storage capacitor 70 is a capacitive element that functions as a storage capacitor that temporarily holds the potential of each pixel electrode 9a in response to supply of an image signal. The storage capacity 70 will be described in detail below.

  Hereinafter, the storage capacitor 70 in the liquid crystal device according to the present embodiment will be described with reference to FIGS. 4 and 5. 4 is a cross-sectional view showing a wiring structure of the liquid crystal device according to the first embodiment, and FIG. 5 is a cross-sectional view showing a comparative example of the wiring structure of the liquid crystal device according to the first embodiment. In FIGS. 4 and 5, the wiring on the lower layer side from the scanning line 11a and the upper layer side from the upper electrode 300 are not shown, and this also applies to the subsequent drawings. In addition, here, the layers illustrated in FIGS. 4 and 5 will be described in detail with a focus on the wiring structure, and description of other configurations will be omitted as appropriate.

In FIG. 4, in the wiring structure of the liquid crystal device according to the present embodiment, a stopper film 200 is formed so as to cover the scanning line 11a. The stopper film 200 is made of, for example, a nitride film such as silicon nitride (SiNx) or titanium nitride (TiN), or an oxide film such as alumina (Al ₂ O ₃ ), and has a thickness of about 0.05 to 0.2 μm. is there. In particular, when the stopper film 200 is formed of a light-shielding film, it can also function as a light-shielding film that prevents light from entering the TFT 30 or the like disposed on the lower layer side of the stopper film 200. is there.

  On the upper layer of the stopper film 200, a step forming film 45 is formed. The step forming film 45 is made of, for example, an oxide film. The thickness of the step forming film 45 is, for example, about 0.2 to 0.5 μm, and is configured to be thicker than the stopper film 200 described above. Thus, by making the step forming film 45 relatively thick, a step for forming a capacitor as shown in the figure can be effectively formed. Although the manufacturing process will be described in detail later, when the step forming film 45 is patterned by etching or the like, the stopper film 200 functions as a protective film that protects a layer on the lower layer side such as the scanning line 11a. To do.

  The step formed by the step forming film 45 may be formed after the surface of the stopper film 200 is planarized, for example, or due to the presence of a wiring or the like formed on the lower layer side of the stopper film 200, It may be formed using a step formed on the surface of the stopper film 200. Further, in addition to the step formed by the step forming portion 45, the step due to the presence of the wiring on the lower layer side of the stopper film 200 as described above may be used as the step for arranging the capacitor.

  A lower electrode 71 is formed at the above-described step so as to straddle at least the side wall. Further, the upper electrode 300 is formed so as to face the lower electrode 71 through the capacitive insulating film 75. A spacer insulating film 46 is partially formed between the lower electrode 71 and the capacitor insulating film 75. The spacer insulating film 46 functions as a protective film that protects the layers such as the lower electrode 71 when the upper electrode 300 is patterned by etching or the like, for example. Further, the lower electrode 71, the capacitor insulating film 75, the upper electrode 31, and the spacer insulating film 46 each include a light-shielding metal or the like, thereby functioning as a built-in light-shielding film that blocks light incident on the TFT 30 or the like. It may be configured to.

  The lower electrode 71, the capacitor insulating film 75, and the upper electrode 300 form a storage capacitor 70, and are electrically connected to, for example, the pixel electrode 9a (see FIG. 3) to display characteristics such as improving contrast and reducing flicker. It is possible to improve. Here, in particular, the storage capacitor 70 is formed at the level difference due to the level difference forming film 45 described above, and thus becomes larger than the case where it is formed on a flattened surface, for example.

  In FIG. 5, in the comparative example of the liquid crystal device according to the present embodiment, the step having the side wall that is cut off from the stopper film 200 is not formed by the step forming film 45. Therefore, the storage capacitor 70 is formed on a flat surface, and the capacitance area is reduced as compared with the liquid crystal device according to the present embodiment described above. Even if a step is to be formed, since the stopper film 200 is not formed, high accuracy is required for etching and the like, which may lead to a complicated and sophisticated manufacturing process.

  Returning to FIG. 4, in the liquid crystal device according to the present embodiment, since the capacitance is also formed in the portion corresponding to the side wall of the step forming film 45, the capacitance is increased by that amount. . In addition, since the capacitors are arranged three-dimensionally, it is possible to increase the capacitance without increasing the arrangement area when viewed in plan.

  Furthermore, in this embodiment, by setting the scanning line 11a to the same potential as the upper electrode 300, it is possible to form a storage capacitor using the stopper film 300 as a dielectric film by the scanning line 11a and the lower electrode 71. . That is, two parallel storage capacitors can be formed on the upper layer side and the lower layer side with the lower electrode 71 as the center. With this configuration, the capacity can be further increased without increasing the planar arrangement area.

  As described above, according to the electro-optical device according to the present invention, it is possible to increase the capacity more easily and efficiently by providing the stopper film and the step forming film.

Second Embodiment
Next, a liquid crystal device according to a second embodiment will be described with reference to FIGS. FIG. 6 is a sectional view showing a wiring structure of the liquid crystal device according to the second embodiment, and FIG. 7 is a sectional view showing a comparative example of the wiring structure of the liquid crystal device according to the second embodiment. 8 and 9 are cross-sectional views showing modifications of the wiring structure of the liquid crystal device according to the second embodiment. Note that the second embodiment differs from the first embodiment described above in that the lower electrode 71 is electrically connected to the relay electrode 6a ′ through the contact hole 83, and the other configurations are generally the same. It is. Therefore, below, a different part from 1st Embodiment is demonstrated in detail, and description shall be abbreviate | omitted suitably about the overlapping part.

  In FIG. 6, the lower electrode 71 is electrically connected to the relay electrode 6 a ′ through the contact hole 83. The relay electrode 6 a ′ is an electrode made of the same film as the data line 6 a and electrically connected to the storage capacitor 70. The contact hole 83 is provided so as to penetrate the interlayer insulating film 44 and the stopper film 200 as shown in the figure. The contact hole 83 is preferably not too deep for manufacturing reasons. Therefore, in the second embodiment, it is preferable that the stopper film 200 is formed thinner as long as the function as the protective film described above can be maintained.

  Here, in particular, in the liquid crystal device according to the second embodiment, as in the first embodiment described above, the storage capacitor 70 is formed at a level difference due to the level difference forming film 45, and thus formed on a flattened surface, for example. It becomes larger than the case where it is done.

  In FIG. 7, in the comparative example of the liquid crystal device according to the second embodiment, the step having the side wall that is cut off from the stopper film 200 due to the step forming film 45 is not formed. Therefore, the storage capacitor 70 is formed on a flat surface, and the capacitance area is reduced as compared with the liquid crystal device according to the present embodiment described above. Even if a step is to be formed, since the stopper film 200 is not formed, high accuracy is required for etching and the like, which may lead to a complicated and sophisticated manufacturing process.

  Returning to FIG. 6, compared with the comparative example described above, in the liquid crystal device according to the second embodiment, the capacitance is also formed in the portion corresponding to the side wall of the step forming film 45, so that the capacitance increases accordingly. To do. In addition, since the capacitors are arranged three-dimensionally, it is possible to increase the capacitance without increasing the arrangement area when viewed in plan.

  In the second embodiment, in addition to the step formed by the step forming film 45, the step formed on the surface of the stopper film 200 due to the presence of the scanning line 11a is further compared with the first embodiment. The storage capacitor 70 is formed by using it. As a result, the capacity can be further increased without increasing the planar arrangement area.

  Note that the wiring structure shown in FIG. 6 is merely an example of the configuration in the second embodiment, and for example, the following configuration can be adopted.

  As shown in FIG. 8, when the upper electrode 300 is formed so as to cover the lower electrode 71 at the left end in the figure, the upper electrode 300 is not patterned by etching or the like at the left end in the figure. Therefore, there is no possibility that the lower electrode 71 is damaged by etching or the like. Therefore, the spacer insulating film as shown in FIG. 6 is not formed at the left end in FIG. If comprised in this way, it will become possible to comprise an apparatus, without making a layer structure unnecessarily complicated.

  As shown in FIG. 9, it is possible to create a new step by leaving the step forming film 45 on both sides of the contact hole 83. In this case, the length of the contact hole 83 is somewhat deeper than in the case shown in FIGS. 6 and 8, but the capacity can be effectively increased by the increase in the level difference. .

  As described above, according to the liquid crystal device according to the second embodiment, even when the contact hole 83 exists, it is easier and more efficient by forming a step as in the first embodiment described above. Therefore, the capacity can be increased.

<Method of manufacturing electro-optical device>
Next, a method for manufacturing the electro-optical device described in the second embodiment will be described with reference to FIGS. FIG. 10 to FIG. 13 are process diagrams sequentially showing each process of the manufacturing process. In FIG. 13, for convenience of explanation, the relay electrode 6a ′, the step forming film 45, and the stopper film 200 shown in FIGS. 10 to 11 are omitted. In the following, the manufacturing process of the wiring and the like described in the embodiment of the electro-optical device will be described in detail, and the description of the other wiring and the like will be omitted.

  In FIG. 10, in the method of manufacturing the electro-optical device according to this embodiment, first, the data line 6a and the relay electrode 6a 'are formed. The data line 6a and the relay electrode 6a 'are formed of the same film. Subsequently, the stopper film 200 is formed by, for example, a low pressure CVD method. The stopper film 200 is typically formed so as not to overlap the opening region in the display region 10a (see FIG. 1). That is, for example, as shown in the drawing, a portion extending in the direction along the data line 6a (that is, the Y direction) and a portion extending in the direction along the scanning line 11a (see FIG. 3) (that is, the X direction). Formed to have. The stopper film 200 is desirably formed of a material that can be easily processed such as etching, for example, in order to make the manufacturing process easier. For example, if the stopper film 200 is formed of a nitride film, it can be easily etched using hot phosphoric acid or the like. Further, the stopper film 200 may be formed of a material having a high light shielding performance in order to shield light that is about to enter the TFT 30 (see FIG. 3) disposed on the lower layer side.

  When the stopper film 200 is formed, a step-forming film 45 made of, for example, an insulating film is formed so as to cover the entire stopper film 200 in plan view. Subsequently, the step forming film 45 is etched leaving only the edge portion as shown in the figure. Therefore, the portion from which the step forming film 45 is removed is in a state where the stopper film 200 is exposed, and a step having a side wall that stands out from the stopper film 200 is formed so as to surround the portion.

  When the step forming film 45 described above is etched, the stopper film 200 functions as a protective film for protecting the wiring existing on the lower layer side of the stopper film 200 such as the data line 6a and the scanning line 11a. Therefore, the side wall as described above can be easily formed by etching. In addition, the stopper film 200 prevents the data line 6a and the scanning line 11a from being short-circuited with other wirings, electrodes, or the like disposed so as to face each other due to excessive etching.

  Further, since the stopper film 200 is formed, the etching depth of the step forming film 45 does not vary. For this reason, there is little or no variation in the storage capacitor 70 formed at the step. Therefore, even when the etching accuracy is not so high, the capacity can be stably increased.

  As described in the above-described embodiment of the electro-optical device, the capacitance is increased by the height of the side wall at the step. However, as shown in the figure, since the side wall is provided so as to surround the stopper film 200, for example, even when the side wall height is set to 1 μm, the capacity can be increased by about 20% as a whole. is there. Such an effect is exhibited remarkably when the arrangement area of the storage capacitor 70 becomes small due to the downsizing of the device or the improvement of the aperture ratio.

  In the step shown in FIG. 11, first, a contact hole 83 is formed in the relay electrode 6a '. Then, the lower electrode 71 is formed so as to be electrically connected to the relay electrode 6 a ′ through the contact hole 83. At this time, the lower electrode 71 is formed so as to straddle the step formed by the step forming film 45. Therefore, the capacity can be increased as described above.

  In the step shown in FIG. 12, a spacer insulating film 46 is formed. The spacer insulating film 46 is once formed so as to cover the entire surface of the lower electrode 71 and then etched, and as shown in the drawing, a portion for forming a capacitor is opened by etching or the like. That is, the spacer insulating film 46 is removed leaving the edge portion of the lower electrode 71 and the peripheral portion of the contact hole 83. As a result, the lower electrode 71 is exposed in the opening of the spacer insulating film 46.

  In this case, by making the etching region of the spacer insulating film 46 slightly larger than the etching region of the step forming film 45 described above, the step is also formed by the spacer insulating film 46 as shown in FIG. Can be formed. That is, the capacity can be further increased.

  In the step shown in FIG. 13, first, the capacitor insulating film 75 is formed so as to cover the opening of the spacer insulating film 46. Subsequently, the upper electrode 300 is formed so as to cover the formed capacitive insulating film 75. Therefore, the upper electrode 300 and the lower electrode 71 are disposed to face each other through the capacitive insulating film 75 in the opening portion of the spacer insulating film 46. Thereby, the storage capacitor 70 is formed. As described above, the storage capacitor 70 is increased by the step formed by the step forming film 45.

  As described above, according to the method of manufacturing the electro-optical device according to the present embodiment, it is possible to more easily manufacture the electro-optical device having an increased capacity efficiently.

<Electronic equipment>
Next, the case where the liquid crystal device which is the above-described electro-optical device is applied to various electronic devices will be described. FIG. 14 is a plan view showing a configuration example of the projector. Hereinafter, a projector using the liquid crystal device as a light valve will be described.

  As shown in FIG. 14, a projector 1100 includes a lamp unit 1102 made up of a white light source such as a halogen lamp. The projection light emitted from the lamp unit 1102 is separated into three primary colors of RGB by four mirrors 1106 and two dichroic mirrors 1108 arranged in the light guide 1104, and serves as a light valve corresponding to each primary color. The light enters the liquid crystal panels 1110R, 1110B, and 1110G.

  The configurations of the liquid crystal panels 1110R, 1110B, and 1110G are the same as those of the liquid crystal device described above, and are driven by R, G, and B primary color signals supplied from the image signal processing circuit. The light modulated by these liquid crystal panels enters the dichroic prism 1112 from three directions. In the dichroic prism 1112, R and B light is refracted at 90 degrees, while G light travels straight. Therefore, as a result of the synthesis of the images of the respective colors, a color image is projected onto the screen or the like via the projection lens 1114.

  Here, paying attention to the display images by the liquid crystal panels 1110R, 1110B, and 1110G, the display image by the liquid crystal panel 1110G needs to be horizontally reversed with respect to the display images by the liquid crystal panels 1110R and 1110B.

  In addition, since light corresponding to each primary color of R, G, and B is incident on the liquid crystal panels 1110R, 1110B, and 1110G by the dichroic mirror 1108, it is not necessary to provide a color filter.

  In addition to the electronic device described with reference to FIG. 14, a mobile personal computer, a mobile phone, a liquid crystal television, a viewfinder type, a monitor direct view type video tape recorder, a car navigation device, a pager, and an electronic notebook , Calculators, word processors, workstations, videophones, POS terminals, devices with touch panels, and the like. Needless to say, the present invention can be applied to these various electronic devices.

  In addition to the liquid crystal devices described in the above embodiments, the present invention includes a reflective liquid crystal device (LCOS), a plasma display (PDP), a field emission display (FED, SED), an organic EL display, and a digital micromirror device. (DMD), electrophoresis apparatus and the like are also applicable.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. The manufacturing method of the electro-optical device, the electronic apparatus including the electro-optical device, and the wiring structure are also included in the technical scope of the present invention.

1 is a plan view illustrating a schematic configuration of a liquid crystal device according to a first embodiment. It is the HH 'sectional view taken on the line of FIG. FIG. 3 is an equivalent circuit diagram of various elements, wirings, and the like in a plurality of pixels formed in a matrix that forms a pixel region of the liquid crystal device according to the first embodiment. It is sectional drawing which shows the wiring structure of the liquid crystal device which concerns on 1st Embodiment. It is sectional drawing which shows the comparative example of the wiring structure of the liquid crystal device which concerns on 1st Embodiment. It is sectional drawing which shows the wiring structure of the liquid crystal device which concerns on 2nd Embodiment. It is sectional drawing which shows the comparative example of the wiring structure of the liquid crystal device which concerns on 2nd Embodiment. It is sectional drawing (the 1) which shows the modification of the wiring structure of the liquid crystal device which concerns on 2nd Embodiment. It is sectional drawing (the 2) which shows the modification of the wiring structure of the liquid crystal device which concerns on 2nd Embodiment. It is process drawing (the 1) which shows the manufacturing process of the liquid crystal device which concerns on 2nd Embodiment later on. It is process drawing (the 2) which shows the manufacturing process of the liquid crystal device which concerns on 2nd Embodiment later on. It is process drawing (the 3) which shows the manufacturing process of the liquid crystal device which concerns on 2nd Embodiment later on. It is process drawing (the 4) which shows the manufacturing process of the liquid crystal device which concerns on 2nd Embodiment later on. It is a top view which shows the structure of the projector which is an example of the electronic device to which the electro-optical apparatus is applied.

Explanation of symbols

  3a ... scanning line, 6a ... data line, 6a '... relay electrode, 9a ... pixel electrode, 10 ... TFT array substrate, 10a ... pixel region, 11a ... scanning line, 30 ... TFT, 44 ... interlayer insulating film, 45 ... step Forming film 46 ... Spacer insulating film 70 ... Storage capacitor 71 ... Lower electrode 75 ... Capacitor insulating film 83 ... Contact hole 200 ... Stopper film 300 ... Upper electrode

Claims (13)

A substrate,
A data line and a scanning line extending across each other in a pixel region on the substrate;
A transistor electrically connected to the data line and the scan line;
A pixel electrode provided corresponding to the transistor;
A stopper film formed on at least one of the data line and the scanning line;
A step-forming film that is locally formed on the stopper film and has a side wall that stands out from the stopper film;
An electro-optical device comprising: a lower electrode formed so as to straddle at least the side wall; and a capacitor having an upper electrode facing the lower electrode through a capacitive insulating film.   The electro-optical device according to claim 1, wherein the capacitor is a storage capacitor electrically connected to the pixel electrode.   The side wall is a side wall that defines the periphery of the opening so that the stopper film faces the upper layer side through the opening formed in the step forming film. Electro-optic device.   The electro-optical device according to claim 1, wherein the side wall is a side wall defining a periphery of the step forming film provided in an island shape. It is formed locally under the stopper film, and further comprises a base film that forms a step on the surface of the stopper film,
The electro-optical device according to claim 1, wherein the capacitor is also formed on the step. The other wiring that is not at least one of the data wiring and the scanning line, or another wiring different from both the data wiring and the scanning line is locally formed under the stopper film, A step is formed on the surface of the stopper film depending on the presence or absence of the other wiring,
The electro-optical device according to claim 1, wherein the capacitor is also formed on the step.   The electro-optical device according to claim 1, further comprising a spacer insulating film between the lower electrode and the upper electrode. Further comprising another capacitive electrode formed from the same film as the scanning line and having the same potential as the upper electrode,
The said stopper film | membrane functions as a dielectric film which construct | assembles the other capacity | capacitance connected in parallel with the said capacity | capacitance between the said other capacity | capacitance electrode and the said lower electrode. The electro-optical device according to Item.   9. The electricity according to claim 1, wherein the stopper film is provided in a non-opening region excluding an opening region through which light contributing to display is transmitted or reflected in the pixel region. Optical device.   The electro-optical device according to claim 1, wherein the stopper film includes a nitrogen compound.   An electronic apparatus comprising the electro-optical device according to claim 1. A data line and a scanning line extending crossing each other in a pixel region on the substrate; a transistor electrically connected to the data line and the scanning line; and a pixel electrode provided corresponding to the transistor. A method of manufacturing an electro-optical device provided,
Forming a stopper film on at least one of the data lines and the scanning lines;
Forming a step forming film having a side wall which is cut off from the stopper film by patterning by etching on the stopper film;
Forming a lower electrode straddling at least the side wall in a step-like manner, and an upper electrode facing the lower electrode through a capacitive insulating film, and forming a capacitor by the lower electrode and the upper electrode. A method for manufacturing an electro-optical device. A first wiring and a second wiring extending crossing each other;
A stopper film formed on at least one of the first wiring and the second wiring;
A step-forming film that is locally formed on the stopper film and has a side wall that stands out from the stopper film;
A wiring structure comprising: a lower electrode formed so as to straddle at least the side wall; and a capacitor having an upper electrode facing the lower electrode with a capacitor insulating film interposed therebetween.

Images